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german
         Magazine of the Deutsche Forschungsgemeinschaft




         1/2004 On Minnesang in the Database Getting a Grip on
         the Computer World A Hand Full of Technology with Finger-
         tip Control When Small Organisms Have a
         Big Effect An Insect’s Life in a Scented World
                                     german research 1/2004




                                         Commentary
In this issue
                                         Johannes Dichgans
                                         Stimulation for Clinical Research . . . . . . . . . . . . . . . . . . . . . . . . p. 2
Compressed Air
for a Robotic Hand                       Engineering Sciences
Artificial hands are needed for          Robert Wynands, Georg Bison, Antoine Weis
a wide variety of applications.          Another Kind of Heart Murmur . . . . . . . . . . . . . . . . . . . . . . . . . p. 4
The important thing is, to simu-
                                         Günther Schmidt
late the human hand’s great
mobility and dexterity. The              Getting a Grip on the Computer World . . . . . . . . . . . . . . . . . . p. 6
hand developed by engineers              Marcell Meuser, Hubertus Murrenhoff
from Aachen is distinguished             A Hand Full of Technology with Fingertip Control . . . . . . . . . p. 9
by its specialised grasping and
holding abilities. It is also the
first hand that is not powered by        Arts and Humanities
an electric motor, but instead           Armin Schlechter, Karin Zimmermann, Matthias Miller
operates using compressed air.
Page 9                                   On Minnesang in the Database . . . . . . . . . . . . . . . . . . . . . . . . p. 12

                                         Life Sciences
Insights into                            Otto L. Lange
an Ecosystem                             When Small Organisms Have a Big Effect . . . . . . . . . . . . . . . p. 16
Living soil crusts extend from           Giovanni Galizia
the deserts to the tropics and
from the Arctic to the Antarctic.        An Insect’s Life in a Scented World . . . . . . . . . . . . . . . . . . . . . p. 21
Not only do they form remark-            Jörg Schmidtke, Peter Nürnberg, Michael Krawczak
ably diverse and resilient com-          Rhesus Monkeys and Reproductive Strategy . . . . . . . . . . . . p. 24
munities, but they also provide
the soil with effective protection       Gerald G. Schumann
against erosion by wind and              The Fight against Retroviruses . . . . . . . . . . . . . . . . . . . . . . . . . p. 26
water. The preservation and
regeneration of these crusts
thus plays an important role in
the conservation of the global
landscape for the future. Basic
research in biology can make                                      Invitation to the
a contribution to this. Page 16
                                                                  Middle Ages
                                                                  Manuscripts are cultural and historical records
The Effect                                                        of great significance. This includes the “Renner”
Scents Have                                                       manuscript, which was completed around 1430
                                                                  in Nuremberg (Page 12).
Insects have a highly developed                                   Cover photo: Universitätsbibliothek Heidelberg
sense of smell. This gives them
their sense of direction when
hunting for food or searching            Impressum
for a mate. A detailed study of
the olfactory system in honey            german research is published by the Deutsche Forschungsgemeinschaft (DFG, Ger-
bees and soldier ants has been           man Research Foundation); Editorial staff: Dieter Hüsken (editor-in-chief, design),
                                         Dr. Rembert Unterstell, Ursula Borcherdt-Allmendinger, Angela Kügler-Seifert;
conducted to discover how                Translation: SciTech Communications GmbH, Heidelberg; Publisher: WILEY-VCH
scents are processed in the              Verlag GmbH & Co. KGaA, Weinheim, P.O. Box 10 11 61, D-69451 Weinheim
brain. The results obtained from         (Germany); Annual Subscription price 2004: € 44.00 (Europe), US $ 48.00 (all other
this study can also be partially         countries) including postage and handling charges. Prices are exclusive of VAT
                                         and subject to change. Printed by: Bonner Universitäts-Buchdruckerei; Address of
applied to the human olfactory           editorial staff: Deutsche Forschungsgemeinschaft, Press and Public Relations
system. Page 21                          Division, Kennedyallee 40, D-53175 Bonn (Germany);
                                         E-mail: postmaster@dfg.de; Internet: www.dfg.de; printed
                                         on chlorine-free bleached paper with 50% recycling fibres.         ISSN 0172-1518
                                                                     german research 1/ 2004
                                                                              Commentary



    C
          linical research in Germany is       jects that, after first having obtained   dent experts in the clinical sciences.
          in need of stimulating impetus.      the informed consent of the partici-      Experience has shown that many
          This is why the Deutsche             pants, are undertaken in accor-           questions can only be successfully
    Forschungsgemeinschaft in cooper-          dance with a clearly defined study        explored independently of the phar-
    ation with the Federal Ministry of         protocol at various locations, some-      maceutical industry and with the
    Education and Research (Bun-               times on a worldwide basis, and           financial resources provided by
    desministerium für Bildung und             correspondingly require a large           public research funding institutions.
    Forschung, BMBF) has introduced            number of patients.
    the new “Clinical Studies” pro-               However, the objective of the


                                                                                         T
    gramme. Its purpose is to promote          new “Clinical Studies” funding                  he proper implementation of
    clinical researchers in a concerted        programme is to support not only                clinical studies requires a high
    effort and to facilitate networking.       studies with large patient pools,               degree of professionalism; this
    This is all done for a good reason!        but also those focusing on smaller        is currently the exception rather
    The importance of clinical research        groups of patients. The pharmaceu-        than the rule at the participating
    is obvious: People everywhere fol-         tical industry has no direct econom-      clinical institutions. With this in
    low health care research with great        ic interest in these latter research      mind, the funding programme aims
    interest, and even with specific ex-       projects. One such example is the         to significantly improve the existing
    pectations, because they have high         treatment of malignant brain tu-          research culture and to provide the
    hopes concerning the results of such       mours of which only about 3,600           know-how to participating universi-
    research for the prevention, diagno-       occur each year. In other words, the      ty hospitals for organizing and exe-
    sis and treatment of disease. At the       funding programme is aimed exclu-         cuting international clinical studies
    same time, it has been known for           sively at science-driven clinical         that are as excellent as they are in-
    many years that while the state of         studies. These differ significantly       novative. The observance and im-
    clinical research in Germany is first-     from drug approval studies in that        plementation of internationally rec-
    rate in some areas, it is less than        they focus on a clinically important      ognized research standards (e.g.,
    satisfactory in others, especially in      scientific question and are con-          the “Good Clinical Practice” Guide-
    patient-oriented research. This is         ceived and published by indepen-          lines of the International Confer-
    particularly noticeable from a struc-
    tural perspective and in terms of the
    international competitiveness of the
    research undertaken. These defi-
    ciencies become apparent in a study
    by the Boston Consulting Group
    which indicates that Germany takes
    one of the last places, behind Den-
    mark, Great Britain and the Nether-
    lands, in a ranking of countries by
    the number of publications (relative
    to population) reporting on clinical
    studies. This is so despite the fact
    that Germany, with a great number
    of specialists and top-notch medical
    facilities, in principle has all the
    proper conditions for conducting
    patient-oriented research. In 1999
    the DFG already unambiguously
    stated this fact in its white paper on
    “Clinical Research” which provided
    an overview of the state of German
    clinical research, analysed its defi-
    ciencies and suggested improve-
    ments. In the meantime the recom-
    mendations made by this white
    paper have now begun to be imple-
    mented. Tangible and creative
    momentum has resulted from the
    associated analysis. One example is
    our “Clinical Studies” programme.
       What does the term – “clinical
    studies” – actually mean? Clinical
2   studies are systematic research pro-
                                 german research 1 / 2004
       ence on Harmonization) is a deci-       funding proposals can then be sub-         ment and the career paths of those
       sive factor and an important bench-     mitted in the second stage where           with scientific talent: the absence of
       mark. Within the framework of this      they will again be discussed by a          time for science with an overload of
       programme, the DFG will fund clin-      group of reviewers.                        clinical care tasks, the absence of
       ical studies of non-pharmacological                                                structured training in the sciences
       therapies as well as studies focusing                                              and unsatisfactory career prospects


                                               T
       on clinical diagnosis and prognosis.          he programme is intended not         for clinical researchers when com-
       In a complementary effort, the                only to support research excel-      pared with the possibility of serving
       BMBF has undertaken the task of               lence, but also to make med-         as a department head. Another im-
       supporting projects evaluating          ical research more well-known to           portant factor is the chronically in-
       pharmacological treatment meth-         the world at large than has previ-         adequate funding that is available
       ods and meta-analyses involving         ously been the case. The recently          for clinical research.
       the systematic examination of clini-    launched reform process in medical
       cal studies.                            research requires more than just


                                                                                         A
          The DFG and the BMBF expect          new programmes and initiatives. It                 s described and recommend-
       their coordinated and harmonised        demands nothing less than a com-                   ed in the white paper, the
       approach in this area of research to    plete change in the mindset of those               most important and momen-
       achieve particularly long-lasting       responsible for its implementation         tous political reform measure re-
       and effective results. Proposal sub-    at university hospitals. In this con-      mains the separation of hospital
       mission is a two-stage procedure for    text the new funding programme             care on the one hand from teaching
       quality assurance reasons. In the       will also increase the prestige of         and research on the other. Ultimate-
       first stage, applicants submit draft    clinical studies conducted at these        ly, this would mean a division of
       proposals, which are evaluated by       locations. The opportunities for up-       medicine into two different acade-
       an international and independent        and-coming researchers in the clini-       mic careers. However, this would
       group of reviewers. If approval is      cal sciences still need to be signifi-     require a less hierarchically struc-
       granted by the reviewers in the first   cantly improved! Structural hurdles        tured division of labour for clinical
       stage, the complete and detailed        still impede the proper develop-           researchers with significantly small-
                                                                                          er associated areas of responsibility.
                                                                                          Furthermore, there are two more
                                                                                          basic conditions that are absolutely
                                                                                          essential for achieving internation-
Prof. Dr.                                                                                 ally competitive performance in
Johannes Dichgans                                                                         German clinical research: namely,
                                                                                          the recognition of specialisation and
                                                                                          an understanding of the long-term
                                                                                          nature of this type of clinical re-


Stimulation                                                                               search. The “Clinical Studies” pro-
                                                                                          gramme now being launched as a
                                                                                          joint initiative of the BMBF and the
                                                                                          DFG will try to meet these demands.
                                                                                          And in doing so, it will consider the


for Clinical                                                                              special requirements of this type of
                                                                                          research in Germany.




Research                                                                                  Prof. Dr. Johannes Dichgans
                                                                                          Vice President of the
                                                                                          Deutsche Forschungsgemeinschaft
New funding to correct deficiencies in                                                    Johannes Dichgans, Department of Neurolo-
medical research: The DFG and the BMBF                                                    gy, University of Tübingen, is one of the Vice
                                                                                          Presidents of the Deutsche Forschungsge-
launch “Clinical Studies”                                                                 meinschaft. The membership of the Execu-
                                                                                          tive Committee of the DFG consists of one
                                                                                          President and eight Vice Presidents, as well
                                                                                          as the Chairman of the Donors’ Association
                                                                                          for the Promotion of Sciences and Humani-
                                                                                          aties in Germany (Stifterverband für die
                                                                                          Deutsche Wissenschaft).                          3
                                                                            german research 1 / 2004
                             Engineering Sciences



         Another Kind of
                                                                                         field is negligible by contrast. Dur-
                                                                                         ing the heart’s contraction, a pattern
                                                                                         of approximately circular field lines
                                                                                         is found outside the chest exiting
                                                                                         from one side and re-entering the

         Heart Murmur                                                                    chest a short distance away.
                                                                                            However, this physicist’s model is
                                                                                         oversimplified: in reality the heart
                                                                                         consists of four chambers, none of
         New possibilities options in medical diagnostics:                               which is cylindrical. There are two
                                                                                         separate circulatory systems – one
         the magnetic signals of the human heart are recorded                            for the lung and another for the
         to assess its state of health                                                   heart and the rest of the body. Also,
                                                                                         the mechanism of pulse generation
                                                                                         is significantly more complex. As a
                                                                                         result, a complex, but characteristic


    H
           eart diseases are a significant     ond. It inverts the voltage between       interdependence on time and loca-
           problem in industrial coun-         the cell interior and exterior locally,   tion is found in the magnetic field of
           tries and increasingly also in      causing the muscle cell to contract.      a healthy heart.
    developing countries, with a large         During this discharge a small part of        The magnetic field of the human
    percentage of deaths being attribut-       the electric current reaches neigh-       heart is very weak: directly outside
    able to them. A number of proce-           bouring cells that also discharge         the chest the strongest signal peaks
    dures are available for diagnosing         and contract as a result. This causes     barely reach a millionth of the
    heart disease, the most familiar of        the hollow cylinder to contract and       strength of the Earth’s magnetic
    which are listening to heart sounds        push the blood into the circulatory       field. Consequently, magnetocar-
    and recording electrocardiograms           system while creating a weak ion          diography requires highly sensitive
    (ECG). In recent years a promising         flow called a primary current. The        magnetic field detectors. Since the
    new method of heart diagnostics            electrical circuit is closed by a dis-    1970s superconducting quantum in-
    has increasingly become a subject          tributed return current through the       terference devices (SQUIDs) have
    of research: magnetocardiography           surrounding medium. Typical cur-          normally been used for biomagnetic
    (MCG). Rather than recording elec-
    trical heart signals like the ECG,
    MCG records the associated mag-
    netic signals. This harmless and
    contact-free method yields informa-
    tion comparable or even superior to
    the ECG. Currently, magnetocar-
    diography is not yet commonly used
    because it relies on magnetic field
    detectors that require cooling close
    to absolute zero – an expensive and
    cumbersome procedure. Last year,
    our research team at the University
    of Fribourg in Switzerland devel-
    oped a new technique that works at
    room temperature, making MCG
    use possible outside of special high-
    tech medical centres.
       From a physicist’s point of view,
    the physiological processes in the
    heart can be modelled in a very sim-
    ple way. The heart is visualised as a
    blood-filled muscle in the shape of a
    hollow cylinder, with the top and
    bottom being closed by the heart           rents are only about one to ten mi-       measurements. However, these suf-
    valves. The muscle cells are sur-          croamperes.                               fer from the significant disadvan-
    rounded by a saline solution, which          A physical law states that the pri-     tage that depending on construction
    is slightly charged relative to the        mary current is surrounded by a           type they must be cooled to -196 de-
    cell interior. A nerve node is located     magnetic field with field lines that      grees Celsius or even -269 degrees
    at one cylinder end and produces an        concentrically surround the cur-          Celsius. This leads to comparatively
4   electrical pulse about once per sec-       rent’s path. The return current's         large expenditures for energy and
                                 german research 1 / 2004
Magnetocardiography records the heart’s    devices as well as the rapid fluctua-      chosen. The measuring principle
magnetic signals without touching the      tions of the earth’s magnetic field        makes use of the fact that every
patient. The curves show the spatial and   can be a thousand times stronger. It       atom in a caesium vapour at room
temporal distribution of magnetic field
                                           is therefore essential to suppress the     temperature acts like a small mag-
strength.
                                           effect of interfering fields. Normal-      net. By shining a laser beam
                                           ly, this is achieved by performing         through the vapour, all of the mag-
                                           the measurement in a magnetically          nets in it are aligned. Assisted by a
logistics, because expensive lique-        shielded room. Gradiometers – sev-         rotating radio frequency field they
fied gases must be used as coolants.       eral sensors placed one behind an-         then rotate about the local magnetic
   A simple magnetocardiogram can          other – provide an alternative to ex-      field. The atoms modulate the inten-
be recorded by holding the sensor          pensive shielding chambers. In the         sity of the laser beam crossing the
directly in front of the chest and reg-    simplest case, one sensor is located       vapour in the same rhythm. This ro-
istering the magnetic field’s change       immediately outside the chest and a        tational frequency is proportional to
with time. At first sight these curves     second one a few centimetres away.         the magnetic field strength and can
look similar to those of an ECG. An        The heart’s magnetic field decreas-        be measured by observing the in-
image of the spatial distribution of       es rapidly with distance from the          tensity modulation of the laser beam
magnetic field strength, obtained          chest, so the second sensor basically      behind the vapour cell. An experi-
for example by sequential measure-         only records the interferences.            mental difficulty is to achieve the re-
ments at several points in front of        Since these are about equal on both        quired precision at a temporal reso-
the chest, or by using a grid of sever-    sensors, in the difference signal only     lution of only a few milliseconds. To
al simultaneously measuring sen-           the heart’s signal remains.                measure the heart’s magnetic field,
sors next to each other, contains             A competitive magnetocardio-            a change in the rotational frequency
more information. The way in which         graph must offer a magnetic field          of only a few hundred-thousandths
the field distribution changes dur-        sensitivity of one picotesla with a        of one percent must be detected.
ing a heartbeat is an important diag-      time resolution of milliseconds and           To reduce the effect of external
nostic aid. Compared to the heart's        a spatial resolution of one to two         interference in the demonstration
field, typical interfering magnetic        centimetres. For this purpose, a re-       set-up, the magnetocardiograph is
fields of elevators and other iron-        cently developed variant of the opti-      operated in a partially magnetically
containing or electrically operated        cally pumped magnetometer was              shielded room. A further reduction        5
                                                                        german research 1 / 2004
                                                                         Engineering Sciences

    is achieved with a two-sensor mag-
    netic gradiometer. To produce maps
    of the magnetic-field distribution,
    the patient is placed in various posi-
    tions under the sensor and a short
    time sequence of the magnetocar-
    diogram is recorded. From this data
    series a map of the field distribution
    can be generated for any point in
    time during the heartbeat.
       In many cases the magnetocardio-
    gram supplies information equiva-
    lent to that of an ECG, but in recent
    years clinical research has identified
    a variety of diseases in which the
    MCG is clearly superior to the ECG.
    This is particularly evident in cases
    in which the ECG looks normal, de-
    spite the presence of a cardiac prob-
    lem, but where the MCG exhibits ir-
    regularities. These include, for ex-
    ample, Wolff-Parkinson-White syn-
    drome, as well as the hours immedi-
    ately after a myocardial infarction.
    Furthermore, the occurrence of cir-
    cular currents in the heart, whose
    presence is suspected in the case of
    certain severe cardiac arrhythmias,
    for physical reasons does not con-
                                                         Getting a Grip on
                                                         the Computer World
    tribute to an ECG but does to the
    MCG. A magnetic map also proved
    more suited for locating arrhythmo-
    genic centres in the heart muscle
    than an electrical map, which is im-
    portant prior to surgical intervention.              In computer games or other multimedia applications,
       So far, the advantages of magne-                  the user receives only visual and audio sensations.
    tocardiography have only been
    brought to bear in a few select high-                New touch displays help to transmit tactile sensations
    tech medical centres because the
    technical, logistical, and financial
    burden of installing and operating a


                                               M
    SQUID-based system is too heavy                      ultimedia and computer           ciencies in terms of delivering high
    for an ordinary hospital or cardio-                  technologies have become         levels of realism. With its monitor
    logical practice. With the new tech-                 a part of our everyday lives     and speakers, a computer can
    nology, this expense is reduced to          in many ways. Before buying new           presently stimulate only two of the
    such an extent that magnetocardio-          furniture, we can view it on a com-       five human senses. Other sensa-
    graphy will also be affordable and          puter screen from multiple perspec-       tions important for “grasping” the
    practical for medical practices and         tives in a virtual living room. Also      world, conveying a sense of motion,
    remote hospitals. Since magneto-            impressive are the virtual recon-         force or touch, currently cannot be
    cardiography is essentially contact-        structions of famous historical build-    emulated satisfactorily or at all. Fre-
    free, public screening for heart con-       ings, in which computers and multi-       quently, however, it is exactly these
    ditions will be possible once the sys-      media give the user the illusion of       haptic (relating to the sense of
    tem has become market-ready. The            walking through historical rooms          touch) perceptions that turn out to
    potential advantages to general             that no longer exist in reality. Multi-   be key for a comprehensive, realistic
    healthcare are clearly apparent.            media computer games enjoy great          immersion into virtual, computer-
                                                popularity – and not only among           generated worlds and environ-
                PD Dr. Robert Wynands           young people – such as auto racing        ments.
                Dipl.-Phys. Georg Bison         “à la Michael Schumacher”. How-              Customers would certainly ap-
                Prof. Dr. Antoine Weis          ever, with the constant improve-          preciate not only being able to see
                University of Fribourg/         ment of these multimedia systems,         their future furniture on the screen
6               Switzerland                     they often begin to show their defi-      but also to feel its surface texture or
                                  german research 1 / 2004
test the quality of the upholstery.        possible to perform more realistic ac-     The technology makes it possible
Visits to a virtually reconstructed        tions in virtual environments or even      to see a phantom hand on the screen
historical building could be made          to perform teleactions, for example        inserting a virtual radio into a
                                                                                      dashboard while controlling the
significantly more realistic if visitors   via the Internet, across distances.        movements and feeling the object
could run their fingers along the ar-         What does a computer require in         with one’s own hand.
chitectural details and actually have      order to give the user of a multi-
to exert the force necessary to open       modal system haptic sensations in
or close a door. And of course the         addition to visual and audio stimuli?
same applies for computer games.           First it must comprise display de-
Computer game manufacturers                vices that are capable of adequately
have recognised the importance of          stimulating the haptic sensory chan-       finger or a hand, interacting with
haptic sensations, which is why they       nels. Tactile sensations on the fin-       the virtual environment, must be
sell joysticks and steering wheels         gertips can be conveyed, for exam-         blended in the computer image as a
giving the player authentic tactile        ple, by miniature vibration elements       type of phantom, often called an
sensations in addition to the familiar     or using pincushion-like displays          avatar. This ensures that all visual,
audio and visual sensory input.            composed of numerous individual            audio and haptic information trans-
   These examples indicate a recog-        moving rods.                               mitted by the computer and per-
nisable trend in the human-comput-                                                    ceived by the user conveys a harmo-


                                           R
er interface – from today’s multime-             obot-like mechanical struc-          nious overall experience – which is
dia systems to so-called “multi-                 tures can be used to elicit sen-     the crucial factor for realism.
modal” systems, in which the user                sations of force on the fingers,        A few examples of the applica-
receives multisensory stimuli and          hand and elbow. In addition, special       tions developed and executed at the
can act and respond by various             software must be prepared so that          Munich Collaborative Research
means. This vision is also at the cen-     the computer can generate the spe-         Centre show that the “tactile simu-
tre of the research activities of the      cific haptic stimuli on the displays       lation” achievable through multi-
Collaborative Research Centre              and coordinate them with one an-           modality allows a considerably
“High-Fidelity Telepresence and            other. Despite certain similarities        deeper and more comprehensive
Teleaction”, located in the Munich         with high-quality graphics software        grasp of computer-generated worlds
area. Telepresence refers to a feel-       in the way it can generate three-di-       and objects:
ing of being physically present with       mensional visual sensory impres-              Shortly before the introduction of
all relevant human senses in a com-        sions by computer, corresponding           the euro, it was possible not only to
puter-generated, virtual world, or in      haptic computer programs still             visualise the as-yet-physically-un-
a real environment that is not direct-     place high scientific demands on           available one-euro coin, but also to
ly accessible to the person. The in-       the respective modelling, program-         allow one to feel it with the finger-
clusion of the haptic sensory modali-      ming and computer technology. In           tips using a haptic coin model and
ty in telepresence systems makes it        the end, the human organ, such as a        touch displays. Similar techniques      7
                                                                        german research 1 / 2004
    can also be beneficial when used in             the temperature of the housing and         again in specific applications, thus
    medical training. For example, it is            finally even feel the force required       demonstrating a broader applica-
    possible to practice palpating the              to insert it in the instrument panel. A    tion potential. They will increase in
    abdominal wall to locate a beating              recently developed mobile haptic           importance in the near future, for
    artery or to detect a tumour.                   display lets users take a walk             example in intensifying medical
       Another application is associated            through an extended virtual art            training by use of multimodal organ
    with “virtual prototyping”, that is             gallery, while actually moving             or patient simulators, as well as for
    product develop-                                                       through a con-      “rapid prototyping” in digital prod-
    ment on the com-                                                       fined area of a     uct development. Another area that
    puter in the auto-          A long-term research                       laboratory or, in   will benefit from multimodality is
    motive or other                                                        future, even in     teleshopping, in which customers
    industries, such
                                goal is to enable a                        their own homes.    will one day also receive haptic sen-
    that users cannot           more comprehensive and Users can not                           sations of the products whilst brows-
    only see and hear           intensive perception                       only view works     ing through a virtual catalogue. Fur-
    a car radio in a                                                       of art such as      thermore, there are also possibilities
    virtual       instru-       of virtual environments                    paintings      or   for the haptic exploration and ma-
    ment panel, but                                                        sculptures from     nipulation of nanotechnological or
    can also touch it.                                                     all angles, but     molecular biological structures.
    By means of a complex hand/arm                  can even touch them and hold them,            In the longer term, it is altogether
    display, they can feel the weight of            which as we all know is rarely possi-      conceivable that computer-generat-
    the radio when lifting it, experience           ble in a real gallery.                     ed multimodality will one day also
    the smoothness or roughness and                    At present, however, the inten-         extend to other sensory perceptions,
                                                    sive international research efforts        such as taste or smell. This would
                                                    have not yet progressed far enough         make it possible to experience virtu-
                                                    that affordable, mass-market haptic        al or real remote environments even
     A mobile haptic display lets users take a walk display products will be on the hori-      more comprehensively and inten-
         through an extended virtual art gallery,
      while actually moving through a confined
                                                    zon yet in the near future. The ap-        sively.
       area. Users can not only view works of art   proaches to multimodality de-
          such as paintings or sculptures from all  scribed here have, however, al-              Prof. Dr.-Ing. Günther Schmidt
      angles but can even touch and hold them.      ready proven themselves time and             Technische Universität München




8
                                               Engineering Sciences




        A Hand Full of Technology
        with Fingertip Control
        Whether as prosthetics or robotic hands – artificial hands are used for a
        variety of applications. A new, pneumatic robotic hand is making a splash with
        special grasping and holding abilities



I
  t is usually in images of the terri-     good hand and lock in the joint posi-     Finally, it is possible to provide sup-
  ble consequences of war broad-           tions. When the locking function          port for people wherever high preci-
  cast by the media that we see the        was released, spring mechanisms           sion is needed for hours without fa-
importance of prosthetics. Prosthet-       returned the fingers to their neutral     tigue. Such situations commonly
ics replace missing joints and limbs       position.                                 occur in the field of medicine, where
with artificial ones. They have a             Today, in addition to medical          surgeons must perform lenghty op-
long, far-reaching history. The first      uses, artificial hands have found a       erations with great care. This is an
attempts to use artificial hands to        broad field of application wherever       area in which robotic hands can
ease the stigma of a missing limb          dangerous or life-threatening con-        considerably ease surgeons’ work.
were very early. These hands – not         ditions make it impossible to send           Thus there are in principle two
yet functional at that time – were         human beings. Situations such as          development aims for artificial
usually made of wood, ivory or a           chemical plant accidents or defus-        hands: the prosthesis, which recre-
workable metal such as bronze or           ing bombs make it desirable to du-        ates the appearance of the human
iron. The oldest known surviving           plicate the natural dexterity of the      hand as much as possible, and the
artificial hand, which boasts early        human hand artificially. Using peo-       robotic hand which must attain the
joint functionality and a technical        ple for assembly and manufacturing        flexibility and grasp strength of the
interior, is that of Götz von Berlichin-   is also becoming ever more compli-        human hand. Robotic hand devel-
gen (main character in Goethe’s            cated. The growing variety of prod-       opment usually results in an ap-
tragedy of the same title). After he       ucts and rising cost pressures in in-     pearance similar to that of the
lost his right hand in a battle near       dustry generate a high demand for         human hand. However, in contrast
Landshut in 1508 he had an armour-         flexible operating equipment that         to the prosthesis, this is not primari-
er fashion him an artificial hand. He      can simulate the abilities of the         ly for aesthetic reasons, but rather
could position its fingers using his       human hand more cost effectively.         because it is believed that the           9
                                                                       german research 1 / 2004
          The palm of the “Aachen-IFAS-Hand”        Aachen), which, while modelled on        hands weight. In addition, it is capa-
            contains three cylinder-lever drives.   the characteristics and structure of     ble of applying strong forces relative
             They allow the thumb and the two       the human hand, does not try to imi-     to its size with very sensitive pres-
           outer fingers to move parallel to the
           palm. The piston rod is connected to     tate its appearance.                     sure control.
         one end of the proximal joint (the one        While the majority of robotic            Since it uses only air, it is a very
           nearest the hand) and the lever end      hands developed throughout the           environmentally friendly drive prin-
                  is connected to the other end     world are driven by electric motors      ciple. Another advantage is that
                   and to the back of the hand.     or – a few – by compressed fluids, the   pneumatic drives are very easy to
                                                    Aachen robotic hand is the first to be   make fire- and explosion-proof,
                                                    controlled pneumatically, i.e., using    since neither the materials used nor
     human hand has been refined over               compressed air. A pneumatic drive        the drive medium can cause or ac-
     the course of evolution into a nearly          offers a number of advantages over       celerate a fire. Pneumatic energy is
     perfect grasping and manipulating              the electromagnetic principle. For       very easy to store in containers in
     tool.                                          one thing, this type of drive does not   the form of compressed air and is
        The “Aachen-IFAS-Hand” is a ro-             have to be made of any special ma-       generally available in plants and
     botic hand developed at the RWTH               terials. Low-density materials such      hospitals. Finally, pneumatic drives
     Aachen University (Rheinisch-West-             as aluminium or plastic can thus be      are very easy to connect since return
     fälische Technische Hochschule                 used, significantly reducing the         lines can very often be dispensed




10
with in favour of direct ventilation      grees of freedom. It was designed                 movement of the deflection pulley is
into the surroundings. However,           this way to prevent the fingers from              mechanically measured and used to
pneumatic drives also have a num-         colliding.                                        drive the next finger segment. The
ber of disadvantages: The outflow-           Three different types of pneumat-              4th degree of freedom of the human
ing air causes a certain amount of        ic drives were implemented to use                 finger, which makes it possible to
noise, which may have to be sup-          the degrees of freedom and allow                  move the last phalanx, was not re-
pressed. Furthermore, pneumatic           the fingers to move. They are a nor-              produced with a pneumatic drive. It
drives are difficult to regulate due to   mal cylinder, which pivots the prox-              is not really necessary, since the last
the compressibility of air, and finally   imal joint by means of a lever                    phalanx of the human finger cannot
the compressed air used in pneu-          (movement parallel to the palm – 1st              be moved independently of the
matic drives must be dry and clean,       degree of freedom), a swivel drive,               other phalanges. That is why the
which requires processing and fil-        which flexes and extends the proxi-               last phalanx on the “Aachen-IFAS-
tering the compression medium.            mal joint (flexing and extending rel-             Hand” is fixed at a 45-degree angle
   The ongoing miniaturisation of         ative to the palm – 2nd degree of                 to the medial phalanx. This position
pneumatic drives and the                                                                             allows for nearly any con-
sensors used has meant that                                                                          ceivable grips and manipu-
the “Aachen- IFAS-Hand”                                                                              lations. To control the finger
could be reduced to one and                                                                          positions, the hand is oper-
a half the size of a human                                                                           ated in a closed-loop posi-
hand. However, it only has                                                                           tion control. To grasp and
four fingers. A fifth finger                                                                         hold objects, a force control
was decided against since                                                                            loop is used, which ensures
only three fingers are need-                                                                         that the desired grasping or
ed to securely hold an ob-                                                                           holding force is maintained.
ject. To manipulate an ob-                                                                           A typical grasping task is
ject while holding it secure-                                                                        performed using both con-
ly, one finger must be re-                                                                           trol loops. The fingers are
leased and repositioned,                                                                             first brought to the object
making the fourth finger                                                                             using      position    control.
necessary.                                                                                           When the pressure applied
   The “Aachen-IFAS-Hand”                                                                            in the drives exceeds the
has a total of 11 degrees of                                                                         value specified for the
freedom, which means that                                                                            grasping task as a result of
11 independent movements                                                                             the resistance of the surface
can be performed. The two                                                                            of the object, the force con-
outer fingers and the thumb                                                                          trol loop takes over. The
each have three degrees of                                                                           force control, which uses the
freedom and the middle fin-                                                                          pressure within the drives,
ger has two. The outer fin-                                                                          must be very sensitive: too
gers and the thumb can                                                                               little force will cause the ob-
move parallel to the palm (1st de-        The oldest existing moving                        ject to slip, while excessive force
gree of freedom) and also towards         prosthetic hand belonged to Götz                  can damage or destroy the object.
the palm (2nd degree of freedom).         von Berlichingen. He had it made after               A total of 22 pressure sensors and
                                          losing his right hand in a battle in 1508.
The 3rd degree of freedom is the                                                            11 angle sensors integrated within
movement of the medial joint of the                                                         the hand supply the two control
finger. This allows the other pha-                                                          loops with the information they re-
lanx to move towards the palm of          freedom) and a belt drive, which                  quire (the pressure levels in the dri-
the hand.                                 moves the medial joint (flexing and               ves and the joint angles). Two pres-
   The joints of the human finger are     extending with respect to the proxi-              sure sensors are required for each
named according to a simple pat-          mal phalanx – 3rd degree of free-                 degree of freedom because each
tern: The joint that connects the fin-    dom). The cylinder-lever drive is                 drive has two chambers, each of
ger with the palm is called the prox-     found inside the palm, while the                  which can be subjected to pressure.
imal joint (proximus, Latin: nearest).    swivel drive is attached to the palm                 The signals from these sensors
The next joint is the medial joint        and to the cylinder-level drive and               are processed in real time with mea-
(medialis, Latin: middle), and the        makes up the proximal joint. The                  surement and control hardware and
last joint is called the distal joint     belt drive is located in the first pha-           converted into position signals for
(distantia, Latin: distance). The pha-    lanx. This is a pneumatic cylinder                the hand's pneumatic drives.
langes are named in the same way.         with no piston rod, whose linear
The middle finger of the “Aachen-         movement is converted into a pivot-               Dipl.-Ing. Marcell Meuser
IFAS-Hand” cannot move parallel           ing movement by a downstream                      Prof. Dr.-Ing. Hubertus Murrenhoff
to the palm and so only has two de-       belt-roller system. In this way, the              RWTH Aachen                        11
                                                                              german research 1 / 2004
                                                      Arts and Humanities



            On Minnesang
            in the Database
            The mediaeval German manuscripts at the Heidelberg University Library
            are cultural and historical records of great significance. Comprehensive cataloguing
            is making the collection newly accessible for research

                        xtraordinarily fa-       practiced by laymen. It is connected   preventive treatment at that time:
                        mous among the           only partly with the Latin medicine    “Place a bit of saffron tied in a small
                        manuscripts at the       taught at the universities, which      cloth in wine or water, give some of
                        Heidelberg Univer-       was mainly theoretical in nature       this to a sober man to drink and he
                        sity Library is the      and still largely based on ancient     will not become drunk during the
                        Codex Manesse,           knowledge.                             day”. The luxurious life at court
                        also known as the           Many of these collections are in-   could bring on gout, known in the
   Große Heidelberger Liederhand-                tended as a comprehensive weapon       Middle Ages as podagra. The cause
   schrift. It is a significant collection of    against all of the diseases of the     of this affliction could be treated
   German Minnesang (Middle High                 human body “a capite ad calcem” –      with the prescription “Whoever has
   German song texts) and records a              from head to toe (or literally “from   podagra, wine is forbidden to him.
   total of 5400 stanzas of Middle High          head to heel”). But one particular     He must drink honey water”. An-
   German love poetry. An important              reference to the Heidelberg court      other approach was to alleviate suf-
   factor in the fame of the Manesse is          must not be overlooked. Several        fering that was already present. A
   its full-page coloured miniatures in-         recipes deal with alleviating the      gouty big toe or painful hand could
   troducing the songs of the 140 Min-           consequences of excessive eating       be helped by acorns thrust in ox
   nesingers. It also contains the fa-           and drinking – a problem with          gall: “From this make a plaster and
   mous portrait of Walther von der              which the common people of this        tie it on the foot or the hand to drive
   Vogelweide. The manuscript came               time were not burdened. But in fact    out the podagra”.
   into the possession of the Count              Elector Friedrich IV of the Palati-       From these two types of manu-
   Palatine of Heidelberg in the late            nate, born in 1574, died as early as   scripts, the Codex Manesse and the
   16th century and disappeared in the           1610 from the consequences of his      medical recipes, one can get an im-
   confusion of the Thirty Years War.            drunkenness. The following was a       pression of the range of the 848 Ger-
   Its recovery in 1888 from the posses-                                                man manuscripts at the Heidelberg
   sion of the Bibliothèque Nationale                                                   University Library. The Codices
   in Paris and its return to the Heidel-                                               Palatini Germanici make up the old-
   berg University Library was cele-                                                    est collection of vernacular records
   brated as an event of great national                                                 of this magnitude. Until 1623, these
   significance.                                                                        manuscripts were part of the world-
      Less well known are the nearly                                                    renowned Bibliotheca Palatina at
   three hundred vernacular medical                                                     Heidelberg’s Church of the Holy
   manuscripts now being newly cata-                                                    Spirit. This library was founded
   logued in Heidelberg. They are
   largely collections of medical
   recipes, some of which were written                                                           The illustration shows God, depicted
   down by the Elector himself. One                                                        here as an architect, creating the world.
   notable example is the twelve-vol-                                                        It is from a three-volume German Bible
   ume “Book of Medicine”, personal-                                                                and originated around 1477 in the
   ly compiled and set down by Elector                                                   manuscript workshop of Ludwig Henfflin.
   Ludwig V of the Palatinate (1478 to                                                           The workshops tried to speed up the
                                                                                        production of manuscripts by using several
   1544). Many of the authors of the                                                                           scribes and illuminators.
   approximately 150,000 recipes can,                                                   This miniature of Minnesinger Walther von
   however, no longer be identified.                                                    der Vogelweide is the most famous picture
12 This is undoubtedly folk medicine,                                                                   from any German manuscript.

                                   german research 1 / 2004
     upon the death of Elector Otthein-        least the German manuscripts. The      tions are obsolete. More than a third
     rich (1502 to 1559), whose will           Latin, Greek and Hebrew codices        of the collection has already been
     called for the university collection to   that can be traced back to Heidel-     re-catalogued at this time.
     be combined with that of Heidel-          berg University and all printed           The Deutsche Forschungsge-
     berg Castle. In September 1622,           works of the same origin remain in     meinschaft has funded the cata-
     during the Thirty Years War, the          Rome to this day.                      loguing of mediaeval occidental
     Calvinist elector palatine residence        A project to re-catalogue the        manuscripts since the 1960s. This
     was captured by Catholic League           Codices Palatini Germanici has         programme has so far resulted in
     troops. The victorious Duke of            been underway since 1996. This is      over 150 printed catalogues. The
     Bavaria, Maximilian I, presented          the third generation of cataloguing.   “Guidelines for Cataloguing Manu-
     the library to the pope as a war tro-     A brief index appeared in 1817 after   scripts” are used as a compulsory
     phy. The next year it was transport-      the return of the manuscripts in       standard. They are intended to en-
     ed over the Alps on the backs of          1816. Then around 1900, two spe-       sure that the individual libraries in
     mules. In 1816, during a politically      cialists catalogued the collection     Germany create uniform cata-
     favourable period after the fall of       and divided it into an older section   logues.
     Napoleon, Heidelberg Library di-          of German studies and a younger           The manuscript database “Manu-
     rector Friedrich Wilken was able to       one of Palatinate history. After a     scripta Mediaevalia” contains, in
     persuade the Vatican to return at         hundred years, all of these publica-   addition to the index data, complete
                                                                                      descriptions of the manuscript as
                                                                                      well as some fully digitalised manu-
                                                                                      scripts, including some material
                                                                                      from Heidelberg. The results of the
                                                                                      cataloguing now underway in Hei-
                                                                                      delberg are entered in this database
                                                                                      as the project progresses.
                                                                                         What is meant by the term manu-
                                                                                      script description? A manuscript, in
                                                                                      contrast to a printed work that is
                                                                                      part of an edition, is a unique object
                                                                                      in every respect. Depending on the
                                                                                      complexity of a codex, a manuscript
                                                                                      description can comprise anywhere
                                                                                      from half a page to several dozen
                                                                                      pages. An attempt is made to make
                                                                                      the external elements and the con-
                                                                                      tent of the manuscript accessible for
                                                                                      research.
                                                                                         Each catalogue entry consists of
                                                                                      three parts: an external description,
                                                                                      a history of the manuscript and a
                                                                                      breakdown of the contents. The ex-
                                                                                      ternal description deals with the
                                                                                      physical form of the object. This in-
                                                                                      cludes information on the base ma-
                                                                                      terial, generally paper or parch-
                                                                                      ment, the quire formula, which
                                                                                      gives the structure of the book
                                                                                      block, the script, the book decora-
                                                                                      tion and the binding. The Heidel-
                                                                                      berg Codices Palatini are primarily
                                                                                      paper manuscripts. The provenance
                                                                                      of a manuscript begins with its ori-



                                                                                      The Song of Roland (left), written around
                                                                                      1170 in Regensburg by the cleric Konrad
                                                                                      tells the story of Charlemagne battling
                                                                                      against the Moors. The Heidelberg
                                                                                      manuscript contains the oldest version of
                                                                                      this song and is illuminated with 39 high-
14                                                                                    quality illustrations.
The “Renner” manuscript, completed
around 1430 in Nuremberg, bears witness
to the Christian Gospel and is Bamberg
schoolmaster Hugo von Trimberg’s
magnum opus. The round picture shows
the world as the product of Creation.
The phoenix, rising from the ashes,
portends the coming of Jesus Christ.




gin, which in the best case is docu-
mented with a scribe entry or can be
determined by investigating the
script, watermark, binding, dialect
and other aspects. The Heidelberg
history of the Codices Palatini Ger-
manici ends temporarily in 1623
when they were transported to
Rome.
   In many cases, no light can be
shed on the early history of a manu-
script. This is even the case for the
Codex Manesse. While there is
plenty of evidence for its creation in
Zurich during the first thirty years of
the 14th century, the history of the
manuscript is completely unknown
from then until just before it was
moved to Heidelberg in the 16th cen-
tury.
   The provenance is followed by
details on the most important litera-
ture. With such prominent pieces as
the Codex Manesse, this requires a
critical examination of the vast
quantity of literature about this
manuscript. The description of the
contents of the manuscript lists the
individual texts in the order in
which they appear in the manu-
script. In many cases, it is sufficient   an incipit index containing the first       codices. In this specific case, they
to indicate an academic edition           lines of all of the texts, and a person,    give us a fresh look at the castle li-
here. Particularly lesser-known           place and subject index. Without            brary of the Heidelberg electors and
texts will often not have a usable        these indexes, a manuscript cata-           their sources. The medical manu-
title in the manuscripts. In such         logue with its wealth of detailed in-       scripts of the Bibliotheca Palatina
cases, the first and last words,          formation would be completely un-           can once more serve as an example:
known as the incipit and explicit,        usable.                                     their number shows the high value
are given. For example, the begin-           An organic collection such as the        placed on this area of study at the
ning of one text in the Codex Palati-     Codices Palatini Germanici in Hei-          Heidelberg court. Historical li-
nus 212 giving instructions on            delberg is a culturally and histori-        braries thus have a source value
blood-letting reads: “Master Al-          cally significant ensemble. The in-         comparable to that of other histori-
mansor says that from the blood-let-      dividual manuscripts have, in con-          cal records. This applies to an en-
ting comes much hurt and much             trast to collections that have come         tirely unique degree to the holdings
wisdom if one does it at the right        together by chance, an internal, his-       of the Heidelberg Bibliotheca
time…”. In this case, a similar incip-    torically deducible relationship to         Palatina so rich in tradition.
it shows that there are two parallel      one another. This is what the intro-
records of this text in different man-    duction to a manuscript catalogue                 Dr. Armin Schlechter
uscripts. The information provided        deals with. It attempts to create a               Dr. Karin Zimmermann
by the descriptions of the individual     synthesis of the individual observa-              Dr. Matthias Miller
manuscripts goes into two indexes:        tions made regarding the individual               Heidelberg University Library 15
                                                                        german research 1 / 2004
                                                          Life Sciences



             When Small Organisms
             Have a Big Effect
             Living soil crusts exist in all warm and cold arid lands of the world. They not only
             form remarkably enduring living communities, but also protect the soil effectively
             against erosion by wind and water



     T
           he arid lands of the world are                                              also leaf-shaped, foliose and even
           characterised by incomplete                                                 shrub-like, fruticose forms. Lichens
           plant cover, or even its com-                                               are anchored with attachment or-
     plete absence, because in the                                                     gans: cell bundles penetrate into
     deserts, semi-deserts and steppes of                                              and through the soil and solidify it
     the world, as well as in many arctic                                              with a finely branched web of
     regions, there is not sufficient pre-                                             mycelial filaments. There may also
     cipitation for closed vegetation                                                  be mosses and liverworts, which
     cover. Between bushes and plants                                                  also attach themselves to the sub-
     the soil is open and appears to be                                                strate. The result is a microcosmic
     bare. But this appearance is decep-                                               community which has a great, often
     tive. A more detailed analysis shows                                              landscape-forming significance, be-
     that the soil surface is densely popu-                                            cause the activity of these organ-
     lated by tiny organisms. Filaments                                                isms solidifies the soil surface like a
     of blue-green algae, the cyanobac-                                                close-knit carpet. As a result, the
     teria, penetrate the top few millime-                                             soil particles in the uppermost mil-
     tres of soil. They secrete slimy car-                                             limetres or centimetres are no
                                              The composition of living soil crusts
     bohydrates from their sheaths with       is mainly determined by the amount
                                                                                       longer loose and mobile relative to
     which they attach themselves to          of precipitation.                        each other, but are highly interwo-
     particles on the ground. As well as      On a dune in Israel’s Negev desert       ven and glued together. This com-
     bacteria and microfungi, green           (top): in the lifted round clod the      pact layer of soil and living organ-
     algae colonies grow on, or slightly      cohesive soil crust, which was formed    isms forms a “biological soil crust”.
     below, the surface. But the most         by cyanobacteria and algae, can be          This crust formation is extraordi-
     conspicuous are lichens, which are       seen. On Cyprus (right): a white crust   narily important for the stability of
                                              lichen dominates the soil crust in a
     often brightly coloured. Lichens are                                              the soil surface, because it protects
                                              Mediterranean shrub community. In
     symbiotic communities of fungi and       the desert in Namibia: students from     against erosion by wind and water.
     algae. Many species cover the            Würzburg at work during a field trip;    Wind tunnel measurements, taken
     ground in a crusty layer, others are     the soil is covered by crust-forming     by the American crust specialist
     squamulose or scaly, but there are       lichens.                                 Jayne Belnap, demonstrated that




16
crusts are not susceptible to erosion.
They can withstand wind speeds
ten times higher than crustless ref-
erence soils without soil particles
being blown away. If the protective
crust is removed, running water can
also wash away far more material.
Without this protection many arid
and semiarid lands would turn into
dust bowls with a constantly chang-
ing surface structure. Crusts also
play an important role as pioneers in
the recolonisation of disturbed soils
by plants.
   Other properties are also pro-
foundly changed by crust formation.
The organisms and their secretions
expand significantly together with
the soil particles when they are first
moistened by rain, sealing the soil
surface. This significantly reduces
water penetration into the ground.
Instead the water flows downhill
and allows run-off farms to cultivate
plants in desert valleys, as for exam-
ple in the central Negev Highland.
This type of farming was already
practised there by the Nabataeans.
Even on sand dunes, where most of
the water usually seeps away, some
water run-off may become estab-
lished in this manner and so plant
cover may form in the dry valleys.
Biological soil crusts occur in almost
all warm or cold arid lands around
the globe. They may be found in the
cactus deserts of the Americas, the
Eucalyptus savannahs in Australia
and the dry grasslands of the
Mediterranean.       Biological    soil
crusts are also found in the open
polar tundra, at high altitudes and
even in Antarctic locations. On a
small scale, soil crusts even grow in
the gaps of local steppe formations
in central Europe.




                                          17
        The composition of soil crust com-
     munities is mainly determined by
     the amount of precipitation. Mosses
     and liverworts have the greatest
     moisture requirements, while lichens
     predominate in dryer locations. In
     desert areas with a lot of dew and
     mist, such as the Namib, lichens
     with green algae prevail, while
     cyanobacterial lichens are more
     common in the deserts with little
     dew near the Dead Sea for example.
        A sun-scorched desert surface is
     one of the most extreme habitats for
     living organisms on this planet. The
     boundary layer close to the soil is
     where the energy exchange takes
     place, where the highest tempera-
     tures occur during insolation and
     the lowest during nocturnal radia-
     tion of heat. High temperatures of
     up to almost 70°C have been mea-
     sured even in ground lichens in the
     Kaiserstuhl hills in south-western
     Germany, where winter tempera-
     tures may drop to -20°C. In hot


        A leafy whitish ground lichen colonizes
        a soil crust together with mosses in the
         northern Harz mountains near Goslar,
                    Germany. Lichens, algae and
            cyanobacteria densely covering the
         ground on the Colorado plateau, USA
                (below). Bacteria and lichens fix
             nitrogen from the air and thereby
       contribute to fertility in North American
                                      desert soils.




18
                                               Even after years of desiccation
                                               under experimental conditions,
                                               they remain viable. This in itself is
                                               not sufficient, however: any produc-
                                               tive metabolism needs moisture.
                                               The organisms must be able to use
                                               the limited quantities of water and
                                               the all too often very brief moist pe-
                                               riods effectively.
                                                  Only shortly after rainfall does the
                                               desert surface that had not shown
                                               any signs of living activity come to
                                               life. Filaments of cyanobacteria
                                               creep into the light from the upper-
                                               most soil layers. They use the brief
                                               moist period for their metabolism




Soil crusts with dominating crust lichens      and growth. As soon as it becomes
and a high percentage of a brownish-red        drier they retreat a few millimetres
fruticose or shrub-like lichen (far top).
                                               back into the soil. Thanks to their
After mountain bike tires and trampling
have destroyed the soil crust (left), water    sensitive sensors they are capable of
and wind erosion sets in. At the measuring     recognising changes in moisture
station in the Namib desert photosynthesis     levels in their environment and,
and the moisture content of lichen samples     thus, avoiding longer periods of
are monitored.                                 sunlight. Apart from the infrequent
                                               rainfalls, soil crust lichens are espe-
                                               cially capable of using additional
                                               water sources. Mist, or even dew
deserts and polar regions the maxi-            and frost, are sufficient to activate
mum and minimum temperatures                   their metabolism. Dried-out green
are even more extreme. Soil crust              algal lichens can even reactivate
organisms must therefore have                  their metabolism in equilibrium
great resistance to heat and cold.             only with high humidity but without
   The most critical factor at a soil          a single drop of water. These prop-
crust location is water. High insola-          erties enable them to exist in the
tion and low humidity will repeat-             coastal Namib desert, where almost
edly dry out mosses, lichens and               no rain falls, but mist, dew, and high
algae. As poikilohydrous, i.e. inter-          humidity occur regularly. Photosyn-
mittently moistened organisms,                 thetic productivity in biological soil
they are very resistant to drought.            crusts is the most important factor of 19
                                 german research 1 / 2004
     their existence. Recording photo-                begins to shine more brightly, the       hectare from soil crust activity has
     synthetic activity at different natur-           organisms dry out again completely       been demonstrated. This fertilisa-
     al locations and analysis of their re-           and become latent. At this Namib         tion benefits entire ecosystems that
     sponses under controlled conditions              location soil crusts are only active     suffer from nitrogen deficiency.
     provide insight into the ecophysio-              for about 10 percent of the total time      Under natural conditions biologi-
     logical functions of these highly                in the course of a year, whereas cen-    cal soil crusts are omnipresent in
     specialised organisms.                           tral European soil crusts that benefit   the world’s arid lands. However,
         Hundreds of square kilometres in             from extensive rainfall and snow are     humans have become their worst
     the coastal zone of the Namib desert             active for 35 to 65 percent of the       enemy. Particularly in their dry
     are covered by soil crusts. For much             time.                                    state, crust communities are very
     of the day they appear grey and                     In one year a lichen-dominated        sensitive to mechanical impact.
     parched. Every morning after mist                soil crust community can absorb up       They break and crumble under
     or dew has fallen, however, they                 to 370 kilograms of carbon per           human feet and animal's hooves in
     awake to new life and the desert                 hectare from the air and bind it in      cases of overgrazing, they are
     takes on a green lustre. Relative to             plant matter. That is a significant      ground up by car tires and tank
     the surface area, the chlorophyll                contribution to soil improvement in      tracks. Human beings have been
     content of the soil crust is similar to          arid lands with little productivity      pushing their activities ever deeper
     that of a beech leaf for example. The            from flowering plants. This carbon       into arid lands for some time – to
     maximum rates of carbon dioxide                  fixation is also of importance on a      use the last pasture reserves, for
     fixation by crust lichens from the air           global scale, but precise details on     construction or for off-road tourism.
     are of a similar order of magnitude.             the extent of biological soil crusts     The fragile soil crust layer is being
     It is fascinating to think that the oth-         over the entire planet are not cur-      destroyed on a large scale and the
     erwise apparently dead desert floor              rently possible. It is estimated that    soil is then laid bare to wind and
     awakens to life, as if it were a huge            they cover 5 to 15 percent of the        water erosion. This may have dev-
     extended leaf. However, this awak-               Earth’s total land surface. They thus    astating consequences and it is es-
     ening only lasts for a short time,               represent a sizeable link in the glob-   sential that we become aware of
     often less than an hour. As soon as              al carbon dioxide cycle. At many lo-     this danger.
     the mist has dispersed and the sun               cations it is also very important that      An important task of modern
                                                      free-living cyanobacteria of the soil    landscape management in arid
                                                      crusts as well as lichens with a         lands is the protection of soil crusts.
                                                      cyanobacterial partner fix nitrogen      In the USA and Australia extensive
     Mosses and green algae in Antarctica.
                                                      from the air and so increase soil fer-   programmes for their protection are
     They cover and stabilise the soil surface        tility. In North American desert soils   already underway, but the regener-
     in ice-free areas where melting snow             an average annual nitrogen input of      ation of destroyed crusts is a long,
     provides moisture.                               up to nine kilograms of nitrogen per     drawn out process because of their
                                                                                               slow growth. Pure cyanobacteria
                                                                                               crusts are formed relatively quickly,
                                                                                               but it takes many decades before a
                                                                                               lichen-rich crust community recov-
                                                                                               ers from destruction. Since artificial
                                                                                               planting has not been very success-
                                                                                               ful so far, management is restricted
                                                                                               to encouraging and preserving ex-
                                                                                               isting soil crusts. From the deserts to
                                                                                               the tropics and from the Arctic to the
                                                                                               Antarctic we often – quite carelessly
                                                                                               – step on the carpet of biological soil
                                                                                               crusts. They constitute a complex
                                                                                               ecosystem with many highly spe-
                                                                                               cialised organisms living in a com-
                                                                                               plicated equilibrium. Biologists, soil
                                                                                               scientists and landscape ecologists
                                                                                               are trying to understand the struc-
                                                                                               ture and function of this sensitive
                                                                                               living skin that spans the arid lands
                                                                                               of our planet as both protection and
                                                                                               provider.

                                                                                                              Prof. Dr. Dr. h. c. mult.
                                                                                                              Otto L. Lange
20                                                                                                            Universität Würzburg
                                        german research 1 / 2004
                                                     Life Sciences



        An Insect’s Life
        in a Scented World
        Whether searching for food or a partner – scent plays an important
        role for insects. How scents are processed in their brain is answered by studies
        on the olfactory system in honeybees and robber ants



I
  nsects have a pronounced sense
  of smell. For example, bees learn
  to recognise the scent of nectar-
rich blossoms so that they will fly to
those flowers from which they can
collect the most honey for their hive.
Scents also play an important role in
insects’ search for a mating partner.
The silk moth female attracts males
with sexually attractive substances
over long distances. The males
smell these chemical messages and
fly against the wind to the female.
The partners can even find each
other in the evening twilight. Social
insects, such as bees, ants and ter-
mites, use scents for communica-
tion. We all know about ant roads:
the animals follow a scent trail on        scent. Evolution “wrote” the link be-      In insects the olfactory receptors are
the ground to their destination.           tween scent and behaviour into the         stimulated by various scents. The resulting
These messenger substances pro-            genes. This is entirely different in       impulses are sent to the brain via neural
                                                                                      appendages. The optical sections depict
duced by the animals themselves            the case of environmental scents, as       antennal lobes of an ant (left) and a
and used to communicate with               for example blossom scents by              honeybee (right)
members of their species are called        which bees are lead to a nectar-rich
pheromones.                                diet. Bees must learn these scents
   For animals there is a critical         over the course of their life.             pheromones and are exposed to
difference between environmental              Scientists have examined the            many      different    environmental
scents – such as a blossom scent for       question whether the brain process-        scents. For this purpose, social in-
the bee – and pheromones. Environ-         es these two scent classes different-      sects are particularly suited because
mental scents cannot be predicted,         ly. On the one hand, can the genetic       many of the signals necessary
but pheromones, in a sense, consti-        memory for pheromones be found in          for life in communities require
tute a part of the species’ memory.        the brain and, on the other hand,          pheromones. Honeybees and rob-
For a scent of this type to fulfil its     can we understand the “olfactory           ber ants, which are natives of Cen-
function, a certain genetically deter-     system” that enables the honeybee          tral America and closely related to
mined meaning must be attributed           to reliably recognise every blossom        the Central European wood ant,
to it (i.e., when the animal smells this   of the world? Researchers have pur-        were studied. Numerous pheromones
scent a particular behaviour is trig-      sued two basic ideas: to understand        of known chemical composition and
gered). This behaviour is context-         the processing of scents in the brain,     their triggered behaviours have
dependent, because a sexually im-          the activity they trigger must be          been described for these species.
mature animal will not react to a sex-     measured. And to understand the               In insects the olfactory receptors
ual pheromone. In the correct con-         difference between the processing          are primarily located on the anten-
text the scent will cause stereotyped      of environmental scents and                nae. There are around 60,000 recep-
behaviour without the animal ever          pheromones, species are examined           tors on each honeybee antenna.
having learned to recognise the            that make significant use of               These cells are stimulated by vari- 21
                                                                        german research 1 / 2004
   ous scents, which are sent to the          glomeruli. To measure the scent            able to determine the response pat-
   brain via long neural appendages,          patterns, the scientists first fixed the   terns to various scents in each test
   the axons. The antennal lobe of the        animals in a plastic chamber so that       animal. First, the characteristics of
   bee is an organ that is similar to the     the head could not move. Then they         the patterns produced by the scents
   human olfactory bulb. It looks             cut a window into the head capsule         – that is, pheromones and environ-
   somewhat like a blackberry. Each of        so that they could see the brain and       mental scents – in both species were
   its berries constitutes a functional       dyed the brain with a pigment that         examined. This showed that the
   unit, a glomerulus. When the animal
   smells a scent, a characteristic pat-
   tern of activated glomeruli is gener-
   ated in the antennal lobe. The olfac-
   tory information is not located in in-
   dividual glomeruli, but is based on
   their pattern as a whole. A combina-
   tion pattern of this type can code
   many thousand scents with only a
   few glomeruli – the bee has about
   160. The hypothesis: pheromones
   should produce a predictable and
   constant pattern for all individuals
   of the species, because they are de-
   termined by evolution. A greater
   variability should be assumed for
   environmental scents, because they
   only become meaningful through
   experience. Therefore, the same
   scent should cause differing pat-
   terns among individuals.




     With the so-called optical imag-         changes its colour when nerve cells        coding principle described above is
   ing method the patterns caused by          become active. The researchers             the same for both species and both
   scents in the antennal lobe can be         used fluorescent “calcium green”           scent classes: each scent produces
   measured. The antennal lobe is of          dye, which reacts to calcium. Active       patterns based on several, not nec-
   varying size in different insect           cells increase their intracellular         essarily neighbouring glomeruli. Is
   species: in the bee it has a diameter      calcium concentration which causes         the variability among individuals
   of about 0.25 millimetres, with the        an increased fluorescence. These           larger for environmental scents than
   individual glomeruli having diame-         changes could be measured under            for pheromones? To answer this
   ters between 20 and 50 microme-            the microscope with a special cam-         question, a measure had to be de-
   ters. The ants studied have some-          era. Since the insects could still         veloped. A certain characteristic of
22 what smaller antennal lobes and            smell perfectly, the scientists were       honeybee glomeruli proved useful:
                                german research 1 / 2004
In a maze of scents a honeybee finds        constantly that the causative scent        process, the result is unequivocal:
its favourite flower. Its blackberry        can be identified from them. This re-      when the bee is learning a scent, the
shaped antennal lobe consists of
glomeruli that enclose a common
                                            sult applied not only – as anticipated     resulting pattern is enhanced, but
centre. Certain fragrances stimulate        – for pheromones but also for envi-        the participating glomeruli remain
specific glomeruli. On the left: the        ronmental scents that have no sig-         the same. In this manner, the bee
response to the scent nonanol. On the       nificance for communications with-         can probably more quickly recog-
right: the response to oil of cloves. The   in the species. The initial hypothesis     nise this scent and better differenti-
reaction to different scents, recorded      was clearly refuted. But how do            ate it from other scents. The “olfac-
in sequence for one second, exhibits
                                            bees handle the incredible diversity       tory system” is structured so that it
characteristic patterns.
                                            of flower scents? Apparently, the          can react to millions of scents, while
                                            millions of possible combinations of       learned scents are recognised more
                                            active glomeruli that result from          easily.
they differ in size and shape. Some         their different response characteris-         The results obtained at the insects’
are round while others are elongat-         tics are sufficient for orientation in     antennal lobe are readily transfer-
ed. They are also located in a char-        different environments without             able to the olfactory lobe of humans.
acteristic pattern relative to each         having to learn those scents of cur-       Both olfactory systems are struc-
other. In different animals the             rent relevance.                            tured very similarly and there is evi-
glomeruli can be recognised and                However, it is known that a mem-        dence that scents cause the same ac-
named because of their external             ory trace for scents is present in the     tivity patterns in different humans.
characteristics. A digital atlas of the     antennal lobe. If a bee is offered a          However, the antennal lobe in in-
glomeruli was then produced and             scent and sugar water, it learns the       sects, like the “olfactory bulb” in
used to map the scent responses of          relationship between scent and re-         humans, is only the first station of
the honeybee. This made possible            ward and, when it smells the scent         scent processing. When we, as hu-
the numerical recording of the pat-         the next time, will extend its pro-        mans, are transferred into a mood
tern for each scent in each animal.         boscis in anticipation of the sugar        that we believed long forgotten or
For example, the scent nonanol re-          water. This is classical conditioning.     the odour of spoiled milk deters us
sulted in strong activity in glomeruli      Several regions in the honeybee's          from drinking it, many other regions
17 and 33 in one animal. When com-          brain participate in this learning         of the brain other than the olfactory
pared to other individuals, it turned       process, among them the mushroom           lobe are also participating.
out that this pattern is universal and      bodies and also the antennal lobe. If
nonanol always stimulates glomeruli         the scent-dependent patterns are                        Dr. Giovanni Galizia
17 and 33. The patterns occur so            measured during this learning                           University of California 23
                                                                         german research 1 / 2004
                                                             Life Sciences



            Rhesus Monkeys and
            Reproductive Strategy
            A male rhesus monkey leaves his birth group to reproduce. On Cayo Santiago, the
            “Monkey Island” off Puerto Rico, researchers are searching for the gene that controls
            the primates’ migratory behaviour




   A
           t some time during his puber-
           ty a rhesus monkey lad will
           roam – as the German poet
   Friedrich Schiller put it in his fa-
   mous “Song of the Bell” – “into life
   so wild”. He leaves the shelter of his
   birth group and seeks contact to an-
   other group. For lack of a better al-
   ternative he may even temporarily
   engage in a pure male bond. But
   soon the adolescent rhesus monkey
   notices that females of other groups
   are very interested in young foreign
   males. That is the positive aspect of
   a process known in behavioural bi-           rhesus monkeys live there in several
   ology as “natal dispersal”: emigra-          social groups.
   tion from the birth group with the              It was demonstrated that high-
   objective of reproduction. The               ranking males in a social group –
   downside is that the young men put           though particularly sexually active –
   themselves into great danger while           by no means produce the majority
   “traversing their world” (Friedrich          of offspring. Rather, the offspring
   Schiller). In the first year after leav-     mostly descended from low-ranking
   ing the birth group, 20 to 40 percent        rhesus monkey males who had at-
   of male rhesus monkeys succumb in            tempted to join the new group dur-
   their struggle to survive.                   ing emigration from their birth
      By using molecular genetic meth-          groups. This demonstrated that
   ods for paternity analysis it was re-        natal dispersal serves to avoid in-
   vealed that emigration from the              breeding and maintain the genetic
   birth group actually fulfils a biologi-      flow. To pursue such high level          Young males in the rhesus monkey colony
                                                                                         on the Caribbean island of Cayo Santiago
   cal purpose. On the “Monkey                  goals, however, evolution requires
                                                                                           usually seek to join another group. This
   Island” of Cayo Santiago, located            an instrument that can be applied to      means life-threatening risks but also the
   half a nautical mile east of Puerto          each individual. The fact that almost     prospect of a large number of offspring.
   Rico, we examined which offspring            all advanced mammals and many
   was descended from high-ranking              bird species migrate to reproduce
   males in one social group and which          raises the question of what forces
   from low-ranking immigrant males.            cause the animals to do so. For ge-     siderably: some start looking for a
   The “Monkey Island” is part of the           neticists it seemed obvious to look     new group at the age of three, but
   Caribbean Primate Research Cen-              for an answer in the genes.             others much later. At the age of six
   ter, with which we have been close-             Observations by primatologists       years about 90 percent of all males
   ly cooperating since 1988. The rhe-          aided the search for the gene that      had left their birth group. Several
   sus monkey colony on Cayo Santia-            controls emigration from the birth      groups of researchers also discov-
   go was established by the American           group. They noted that the time         ered that the serotonin level (sero-
   zoologist Clarence Ray Carpenter in          when young rhesus monkey males          tonin is a neurotransmitter) in the
24 1938. Today about one thousand               leave their birth group varies con-     monkeys’ cerebral fluid correlates
                                  german research 1 / 2004
with the age at which the monkeys       terised by anxiety and depression.      tion age of 532 male rhesus mon-
leave their birth group. This depen-    The short variant of the controlling    keys born between 1970 and 1997
dency of migrating age on the sero-     element causes only about half as       on the “Monkey Island” of Cayo
tonin level directed attention to the   many serotonin transporters to be       Santiago. It was already known at
genes that play a role in the sero-     formed as the long variant.             which age these animals had left
tonin metabolism. Of particular in-        The short variant is also found in   their birth group. Comparison with
terest in this context was the gene     rhesus monkeys. On the “Monkey          the recorded genetic data revealed
SLC6A4, responsible for the sero-       Island” of Cayo Santiago about 8        a clear link between the genetic
tonin transporter.                      percent of all animals are homozy-      variants and the emigration age: ho-
  In 1996 Klaus-Peter Lesch’s           gous for the short variant (ss – for    mozygous ss males left their group
working group at the University of      homozygous “small”), 52 percent         at an average age of 57 months,
Würzburg discovered that the short      are homozygous for the long variant     while homozygous ll males were, on
variant of the controlling element of   (ll – for homozygous “large”) and       average, 72 months old upon emi-
this gene, the SLC6A4 promoter, is      the remaining 40 percent are het-       gration. The average emigration
associated with neuroticism in hu-      erozygous (ls). We examined the ef-     age of heterozygous ls animals was
mans, a personality trait charac-       fect of these variants on the emigra-   intermediate at 64 months. For the




                                                                                                                       25
                                                                              Life Sciences



                                                     The Fight against
   first time it was possible to demon-
   strate a link between a genetic and
   a behavioural characteristic in non-
   human primates. The long variant
   causes rhesus monkeys to detach
   from their birth group later. Male
   rhesus monkeys thus pursue two
   different reproductive strategies:
                                                     Retroviruses
   homozygous ss males who emigrate
   early take a significant risk of dying            A gene therapeutic approach for treating viral infections
   during their struggle to survive out-
   side the birth group (20 percent),
                                                     places its bets on incorporated enzymes destroying virus
   but are rewarded with special re-                 particles from within
   ceptiveness by the females of the
   new group. Homozygous ll males
   who emigrate late initially incur a


                                              T
   lower risk by remaining with the                  he immune deficiency disease        suggested by the virologist David
   birth group for longer and also pro-              AIDS which continues to             Baltimore in 1988. In a general strat-
   creating there. If they subsequently              spread worldwide is caused by       egy called intracellular immunisa-
   decide to emigrate from their birth         a member of the retrovirus family.        tion, genes encoding macromole-
   group, however, they take an espe-          „Retrovirus“ is the name given to a       cules that interfere with viral multi-
   cially high risk of mortality during        large group of diverse viruses            plication are introduced into virus-
   their struggle for survival (40 per-        whose genetic information is stored       susceptible cells. Although very
   cent). We therefore put forward the         in RNA molecules. In a retrovirus-        promising results against HIV infec-
   hypothesis that heterozygous males          infected cell, a DNA copy of the          tions have been achieved in cell cul-
   have a selection advantage over ho-         viral RNA is produced and then in-        ture and in animal models by em-
   mozygous males.                             serted into the host cell’s genome.       ploying these strategies, viruses
      If this theory were right heterozy-      Since this is a reversal of the usual     emerged that were able to escape
   gous males should have produced             information flow from DNA to RNA,         inactivation by foreign macromole-
   significantly more offspring than           the term „retro“-virus was coined.        cules through mutation.
   homozygous ones. However, the re-           Retroviral infections cause diseases         A project developed at the Johns
   sults of our ongoing paternity analy-       in humans, which are often fatal.         Hopkins University School of Medi-
   sis on the “Monkey Island” of Cayo          One of the aggressive retroviruses is     cine in Baltimore (Maryland, USA)
   Santiago did not confirm this expec-        the human immunodeficiency virus          and concluded at the Heinrich Pette
   tation. There was no difference be-         (HIV), the agent responsible for the      Institute for Experimental Virology
   tween the average reproductive              aquired immune deficiency syn-            and Immunology at the University
   success of heterozygous and ho-             drome, AIDS. Retroviral infections,       of Hamburg describes a new strate-
   mozygous males. Apparently nature           especially HIV infections, pose a         gy of intracellular immunisation and
   is pursuing a different strategy than       tremendous challenge in biomed-           demonstrates proof-of-principle of
   the classical heterozygote advan-           ical research.                            this strategy in an animal model.
   tage to secure the preservation of             In recent years, remarkable               A strength of the CTVI strategy is
   the serotonin transporter gene vari-        progress has been made in develop-        that it is designed to target a step in
   ant we examined. In our current re-         ing effective combination drug ther-      the viral life cycle that is different
   search we are attempting to eluci-          apies that can control, but not cure,     from those targeted by most other
   date this strategy. It is as yet uncer-     retroviral replication. However,          current anti-HIV gene therapy ap-
   tain how the differences in the gene        even when effective, these drug           proaches. Therefore CTVI gives
   under consideration affect person-          regimens are toxic, they require de-      cause for hope that new treatment
   ality and behaviour. It is conceiv-         manding administration schedules,         methods for this disease which
   able that the formation of serotonin        and resistant viruses can emerge.         remains incurable will be found.
   transporters affects the serotonin          Thus the need for new gene-based          The concept of the CTVI strategy
   level in the cerebral fluid. However,       therapies remains. A novel gene           was originally developed in Jef
   an effect on prenatal brain develop-        therapeutic approach against retro-       D. Boeke’s laboratory at the Johns
   ment is more probable.                      viral infections, called „Capsid-Tar-     Hopkins University. By using the
                                               geted Viral Inactivation“ (CTVI) is       yeast retrotransposon Ty1, a mobile
   Prof. Dr. Jörg Schmidtke                    showing the first signs of success in     genetic element whose transposi-
   Medizinische Hochschule Hannover            an animal model, promising new ef-        tion mechanistically resembles
   Dr. Peter Nürnberg                          ficient alternatives for the treatment    retroviral multiplication, this ap-
   Max-Delbrück-Centrum für                    of these viral infections in humans.      proach was tested for the first time
   Molekulare Medizin Berlin-Buch                 The use of gene therapy in the         as a novel means to interfere with
   Prof. Dr. Michael Krawczak                  treatment of viral infections is a rel-   viral replication. The strategy was
26 Universität Kiel                            atively new concept and was first         shown to inhibit transposition of the
                                 german research 1 / 2004
retrotransposon by at      strategy, it was first
least 98 %. In this ap-    attempted to deacti-
proach antiviral nu-       vate a murine retro-
cleases (enzymes de-       virus causing leukae-
grading      molecules     mia (Murine Leukae-
that carry genetic in-     mia Virus, MuLV) in
formation) are fused       cell culture experi-
to the viral coat pro-     ments. The nucleases
teins forming the cap-     to be tested for their
sid, which surrounds       antiviral    efficiency
the viral genome.          were selected for not
   The process of          having a destructive
retroviral particle for-   effect on the host cell.
mation makes the in-       In cooperation with
corporation of delete-     the virologist Mark
rious proteins into the    Federspiel of the
retroviral capsid rela-    Mayo       Clinic    in
tively easy. After co-     Rochester (Minnesota,
packaging of the viral     USA), we demonstrat-
genome with the            ed that the selected
deleterious nuclease       nucleases did indeed
fusion inside, the core
of the assembled virus
particle, the deleteri-
ous nuclease inter-        Africa is particularly
feres with viral multi-    hard hit by the AIDS
plication by both          epidemic. A destructive
degrading the viral        enzyme – antiviral
genome and inhibiting      nuclease – may help. It
                           is incorporated into the
viral protein activity.    retrovirus particle and
      To test the feasi-   blocks the viral
bility and efficiency of   production by breaking
this new antiviral         down the viral genome.




                                                      27
   inactivate all infectious virus parti-            the Johns Hopkins University in              The demonstration of CTVI
   cles in cell cultures infected with               Baltimore. The antiviral proteins         applicability in an animal model
   MuLV. The virologists Beatrice                    were shown to have no harmful ef-         presents a multitude of perspec-
   Hahn and John Kappes at the Uni-                  fect on the mice, but rather protect      tives: In order to make animals re-
   versity of Alabama at Birmingham                  MuLV-producing mice, which nor-           sistant, or at least less susceptible, to
   used these results to conduct analo-              mally develop certain kinds of blood      retroviral infections the methods de-
   gous experiments in which the suc-                cancer (lymaphatic leukaemia). In         scribed here could readily be used
   cessfully tested nucleases were ex-               transgenic mice producing the an-         to construct improved versions of
   pressed in cell lines infected with               tiviral fusion protein, the number of     farm animals that currently suffer
   the AIDS retrovirus. The results of               infectious particles was reduced by       from retroviral diseases, including
   these experiments were promising                  up to 10-fold, which considerably         chickens (avian leukosis virus),
                                                     delayed the development of                goats (caprine arthritis-encephalitis
                                                     leukaemia and resulted in in-             virus), sheep (Maedi/Visna virus),
   In genetically modified mice carrying             creased longevity in these animals        cattle (bovine leukemia virus), and
   the antiviral fusion protein, the liver's         when compared to their normal,            horses (equine infectious anemia
   affliction by tumour cells was either             MuLV-infected siblings lacking the        virus).
   strongly reduced or – as demonstrated             antiviral fusion protein. It could be        However, the greatest challenge
   in the two images on the left – can not
   be observed at all. In contrast, the
                                                     demonstrated that the fusion pro-         is still posed by human retroviruses
   images on the right show extended                 teins were incorporated into the          such as HIV and the leukaemia-
   tumour cells in the liver tissue of               virus particles of retrovirus-infected    causing HTLV-1 (Human T-cell
   unmodified mice.                                  mice inactivating the viruses.            Leukaemia Virus 1). Short of germ
                                                                                               line gene therapy, targeting a ma-
                                                                                               jority of virus-infected cells by a so-
                                                                                               matic gene therapeutic approach
                                                                                               would be necessary for a robust an-
                                                                                               tiviral effect. The results indicate
                                                                                               that even relatively modest decreas-
                                                                                               es in retroviral titers in vivo can lead
                                                                                               to significant improvements in clini-
                                                                                               cal outcomes. In transgenic mice
                                                                                               this took the form of delayed
                                                                                               leukaemia development and in-
                                                                                               creased life expectancy. Since the
                                                                                               quantity of viruses present in HIV
                                                                                               patients correlates closely to the dis-
                                                                                               ease’s progress, a two- to tenfold re-
                                                                                               duction of infectious viruses, as ob-
                                                                                               served in mice, would have a signif-
                                                                                               icant positive effect on the course of
                                                                                               the disease and would also improve
                                                                                               the patients’ quality of life.
                                                                                                  Building on our research the vi-
                                                                                               rologists Gertrud Beterams and
                                                                                               Michael Nassal at the Albert Lud-
                                                                                               wig University in Freiburg have re-
                                                                                               cently succeeded in employing this
                                                                                               antiviral strategy against the he-
                                                                                               patitis B virus (HBV), which infects
   since the number of infectious virus              Therefore, the mouse model indi-          humans. By targeting a degradative
   particles released by the infected                cates that the antiviral CTVI strate-     nuclease into viral particles the
   cells was reduced by 88 to 99 per-                gy is not only efficient in tissue cul-   number of infectious hepatitis B
   cent. Since the results of such cell              ture but could also provide substan-      particles in cell cultures was re-
   culture experiments cannot readily                tial therapeutic benefits in vivo. By     duced by 95 percent.
   be transferred to living organisms,               altering several factors, it will be-        Thus capsid-targeted strategies
   testing of these strategies in living             come possible to significantly en-        continue to provide a promising ap-
   organisms (in vivo) is indispensable.             hance the antiviral effectiveness.        proach for therapy against a variety
      Transgenic mice producing fu-                  The results suggest that employing        of viruses that affect humans, direct-
   sions of the MuLV capsid protein                  gene therapeutic approaches based         ly and indirectly.
   and the antiviral nuclease (fusion                on similar fusion proteins to fight
   protein) in their cells were specifi-             HIV and other retroviruses could be              PD Dr. Gerald G. Schumann
28 cally bred for these experiments at               of major therapeutic benefit.                    Paul-Ehrlich-Institut, Langen
                                       german research 1 / 2004
The Deutsche Forschungsgemeinschaft                                                              Authors’ Addresses
                                                                                                 Dipl.-Phys. Georg Bison
The Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) is the                     Prof. Dr. Antoine Weis
central self-governing organisation responsible for promoting research in Germany.               Physik-Department, Universität Fribourg,
According to its statutes, the DFG serves all branches of science and the humanities.            Chemin du Musée 3, CH-1700 Fribourg
The DFG supports and coordinates research projects in all scientific disciplines, in par-        Prof. Dr. Johannes Dichgans
ticular in the area of basic research through to applied research. Particular attention is       Zentrum für Neurologie,
paid to promoting young researchers. Every German scientist and academic is eligible             Universitätsklinikum Tübingen,
to apply for DFG funding. Proposals are submitted to peer reviewers, who are elected             Hoppe-Seyler-Straße 3, D-72076 Tübingen
by researchers in Germany in their individual subject areas every four years.                    Ph. D. C. Giovanni Galizia
The DFG distinguishes between the following programmes for research funding: In the              Dept. of Entomology, Room 383, University
Individual Grants Programme, any researcher can apply for financial assistance for an            of California, Riverside, CA 92521, USA
individual research project. Priority Programmes allow researchers from various re-
                                                                                                 Prof. Dr. Michael Krawczak
search institutions and laboratories to cooperate within the framework of a set topic or         Institut für Medizinische Informatik und
project for a defined period of time, each working at his/her respective research institu-       Statistik, Universität Kiel,
tion. A Research Unit is a longer-term collaboration between several researchers who             Brunswiker Straße 10, D-24105 Kiel
generally work together on a research topic at a single location. In Central Research Fa-
cilities there is a particular concentration of personnel and equipment that is required to      Prof. Dr. Dr. h.c. mult. Otto L. Lange
                                                                                                 Julius-von-Sachs-Institut für Biowissen-
provide scientific and technical services.                                                       schaften, Lehrstuhl für Botanik II, Univer-
Collaborative Research Centres are long-term university research centres in which sci-           sität Würzburg, Julius-von-Sachs-Platz 3,
entists and academics pursue ambitious joint interdisciplinary research undertakings.            D-97082 Würzburg
They are generally established for a period of 12 years. In addition to the classic Collab-      Dipl.-Ing. Marcell Meuser
orative Research Centres, which are concentrated at one location and open to all subject         Prof. Dr.-Ing. Hubertus Murrenhoff
areas, the DFG also offers several programme variations. Transregional Collaborative             Institut für fluidtechnische Antriebe und
Research Centres allow various locations to cooperate on one topical focus. Cultural             Steuerungen, RWTH Aachen, Steinbach-
Studies Research Centres are designed to support the transition in the humanities to an          straße 53, D-52074 Aachen
integrated cultural studies paradigm. Transfer Units serve to transfer the findings of
                                                                                                 Dr. Peter Nürnberg
basic research produced by Collaborative Research Centres into the realm of practical            Max-Delbrück-Centrum für Molekulare
application by promoting cooperation between research institutes and users.                      Medizin Berlin-Buch,
DFG Research Centres are an important strategic funding instrument. They concentrate             Robert-Rössle-Straße 10, D-13092 Berlin
scientific research competence in particularly innovative fields and create temporary,           Dr. Armin Schlechter
internationally visible research priorities at research universities.                            Dr. Karin Zimmermann
Research Training Groups are university training programmes established for a specific           Dr. Matthias Miller
time period to support young researchers by actively involving them in research work.            Universitätsbibliothek Heidelberg,
This focuses on a coherent, topically defined, research and study programme. Research            Plöck 107-109, D-69117 Heidelberg
Training Groups are designed to promote the early independence of doctoral students              Prof. Dr.-Ing. Günther Schmidt
and intensify international exchange. They are open to international participants. In In-        Lehrstuhl für Steuerungs- und Regelungs-
ternational Research Training Groups, a jointly structured doctoral programme is of-             technik, Technische Universität München,
fered by German and foreign universities.                                                        Theresienstraße 90, D-80333 München
Other funding opportunities for qualified young researchers are offered by the Heisen-           Prof. Dr. Jörg Schmidtke
berg Programme and the Emmy Noether Programme.                                                   Institut für Humangenetik, Medizinische
Humanities Research Centres were created in the new federal states to improve the ex-            Hochschule Hannover, Carl-Neuberg-
                                                                                                 Straße 1, D-30625 Hannover
isting research infrastructure. These centres have been established for a specific time
period and serve to promote interdisciplinary research.                                          PD Dr. Gerald G. Schumann
The DFG also funds and initiates measures to promote scientific libraries, equips com-           Paul-Ehrlich-Institut, Bundesamt für Sera
                                                                                                 und Impfstoffe, Paul-Ehrlich-Straße 51-59,
puter centres with computing hardware, provides instrumentation for research purpos-             D-63225 Langen
es and conducts peer reviews on proposals submitted within the framework of the
Hochschulbauförderungsgesetz, a legal act which provides for major equipment and                 PD Dr. Robert Wynands
the construction of institutions of higher education in Germany. On an international             Abt. 4.41,
level, the DFG has assumed the role of Scientific Representative to international organ-         Physikalisch-Technische Bundesanstalt,
isations, coordinates and funds the German contribution towards large-scale interna-             Bundesallee 100, D-38116 Braunschweig
tional research programmes, and supports international scientific relations.
Another important role of the DFG is to provide policy advice to parliaments and public
authorities on scientific issues. A large number of expert commissions and committees            Illustrations
provide the scientific background for the passing of new legislation, primarily in the
areas of environmental protection and health care.                                               Querbach (p. 2, back); Wynands (p. 4);
                                                                                                 Bramaz/Schweizerischer Nationalfonds
The legal status of the DFG is that of a private association. Its member organisations in-       (p. 5); Kron/Kammermeier (p. 6, 7);
clude research universities, the Academies of Sciences and Humanities, the Max                   Nitzsche (p. 8); IFAS (p. 9, 10); archives
Planck Society, the Fraunhofer Society, the Leibniz Association, the Helmholtz Associa-          (p. 11); Universitätsbibliothek Heidelberg
tion of National Research Centres, research organisations of general importance, and a           (cover, p. 12, 13, 14, 15); Lange (p. 16, 17,
number of scientific associations. In order to meet its responsibilities, the DFG receives       18, 19, 20); Galizia (p. 21, 22, 23);
funding from the German federal government and the federal states, as well as an an-             Schmidtke (p. 24); Rawlins (p. 25); Wong
nual contribution from the Donors’ Association for the Promotion of Sciences and Hu-             (p. 27 a.); dpa (p. 27 b.); Schumann (p. 28)
manities in Germany.                                                                             Layout of pictures:
                                                                                                 l. = left, r. = right, a. = above, b. = below   29
                                                                                   german research 1 / 2004
www.dfg.de




             S
                  port keeps you
                  fit. This applies
                  to the staff at the
             DFG Head Office too. For over five
             years the DFG sports club has of-
             fered a varied fitness programme.
             Be it in football or volleyball,
             whether in gymnastics or athletics
             – it is impossible to overlook the
             success of their efforts. The cups
             and certificates that have been won
             for various competitions vie for
             space in this show-case.

				
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