Research

Funding: Bundesministerium für Gesundheit, Berlin (als Bestandteil der Finanzierung des WHO-CC)

Project Details:
Outside Europe, data on real antibiotic usage in veterinary medicine are available only in a few countries. In the frame of the project VetCAb-ID, a worldwide usable data base was developed that is provided to project partners for the recording of antibiotic usage in animal populations and to determine the treatment frequency of a herd or flock. The database can be individually adapted to the relevant conditions of the respective country and its animal husbandry. The concept is based on the long-time project VetCAb, where data on veterinary prescription of antibiotics in Germany are collected and analysed continuously in a standardised manner. So far, collaboration was started with partners from Chile, Pakistan, Zambia und, St. Kitts.
Link: https://ibei.tiho-hannover.de/vetcab-id

Results:

Mohsin M, Farooq U, Hartmann M, Brogden S, Kreienbrock L, Stoffregen J. Case Study: Using a Shared International Database to Document Veterinary Consumption of Antibiotics in Pakistan. Antibiotics (Basel). 2023 Feb 15;12(2):394. doi: 10.3390/antibiotics12020394.

https://ibei.tiho-hannover.de/vetcab-id

Cooperation Partners:

- Médico Veterinario, Departamento de Medicina Preventiva, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile;

- Institute of Microbiology, University of Agriculture, Faisalabad, Pakistan

- Department of Disease Control, School of Veterinary Medicine, University of Zambia

- Ross University School of Veterinary Medicine, Basseterre, St. Kitts und Nevis

Funding: Deutsche Forschungsgemeinschaft (DFG), 458.064 EUR

Project Details:
Based on the results of the joint research project, the proposed interdisciplinary follow-up project aims to develop a customised hip prosthesis made of the additively processed titanium alloy Ti-6Al-7Nb (Ti67) with multi-biofunctional surface areas.The biocompatibility and load-compatible design of the implant are achieved by parameter adjustments in powder bed-based selective laser beam melting (LPBF) to create porous as well as geometrically defined surfaces with subsequent PVD thin films. The systems TiN, TiCN, and a-C:Ag, which were investigated in the first funding period, will be used as thin film material, as they differ fundamentally and allow local adaptation of the surface properties. By adding copper, higher strength, ductility, and anisotropy of the additively processed Ti67 are to be adjusted. In addition, the influence of copper on coatability and biocompatibility is addressed. To adjust the stiffness and surface properties locally, the process parameters of the LPBF process are varied so that areas of different porosity and roughness can be produced. In the additively manufactured hip prosthesis, the femoral head and acetabulum are in tribological contact, so the acetabulum possesses bone-like properties by having a porous inner and dense outer structure, while the ceramic femoral head is attached modularly to the hip stem. Since a mechanical support effect of the substrate material is required for PVD thin films, the extent to which the porous inner structure affects the friction and wear behaviour of the coated Ti67 parts is investigated. The interaction between the surface properties of the additively processed Ti67 and the applied PVD thin films as well as the influence on the mechanical, biocompatible and corrosion behaviour are the focus of the investigations. In the area of the hip shaft, it is expected that the porous structures and defined surface roughness in combination with a PVD thin film will lead to bone cell growth being stimulated while at the same time preventing biofilm formation. To be able to specifically adapt the influence of the thin films on the different implant areas, bioassays (including the establishment of Western-Blot-Investigations for the early characterisation of the influence of the thin film on signalling cascades in the cells) are being established in-vitro. In addition, infection scenarios are planned to simulate and control the influence of thin films on bacterial colonisation. With the knowledge gained, a prosthesis true to reality with defined roughness and porosity, including PVD thin film, will be manufactured and tested close to the application. This will verify and demonstrate the potential of the presented approach.

Results:

https://gepris.dfg.de/gepris/projekt/415285024?language=de

Funding: DFG Zi 345/27-1, 328.407 EUR

Project Details:
The aim of this project is to explore for the first time the processes underlying vocal flexibility of a highly vocal and phylogenetically basal primate across development. Previous research of our group revealed that the mouse lemur, a phylogenetically basal primate, exhibits an unexpectedly high degree of vocal flexibility in early ontogeny, which decreases in further development. Our project proposes three different and interrelated work packages by which we will address major components of these unexplored processes. The presence and role of babbling and vocal turn-taking during development, as well as potential determinants, modifying vocal output during development, will be assessed by early and dense sampling of vocal production and standardized bioacoustic and videografic behavioral approaches, using a dataset of 26 developing infants and their 13 mothers. Machine learning, including deep neural network approaches, will be applied to investigate the extent to which the dynamics of vocal development and potential rules can be assessed automatically. Excised larynx experiments and related anatomical and MicroCT-studies of the vocal tract as well as high-speed videorecordings of mouth and tongue movements during vocal production will be performed to uncover the mechanics of vocal production and potential biomechanical constraints in vocal flexibility. Integrating of datasets will allow the validation of the respective methods. The project provides an important empirical basis for comparative research on mammalian vocal communication and contributes to unravel the evolutionary roots of vocal flexibility in primate communication as an important building block for the evolution of human speech and language.

Results:

e.g.,

 

Langehennig-Peristenidou A, Scheumann M (2024). Sex differences in the impact of social relationships on individual vocal signatures in grey mouse lemurs (Microcebus murinus). Philosophical Transaction of the Royal Society B, 379, 20230193. DOI:10.1098/rstb.2023.0193.

 

Langehennig-Peristenidou, A.; Romero-Mujalli, D.; Bergmann, T.; Scheumann, M. (2023). Features of animal babbling in the vocal ontogeny of the gray mouse lemur (Microcebus murinus). Scientific reports, 13(1), 21384.

 

Romero-Mujalli, D.; Bergmann, T.; Zimmermann, A.; & Scheumann, M. (2021). Utilizing DeepSqueak for automatic detection and classification of mammalian vocalizations: a case study on primate vocalizations. Scientific reports, 11(1), 1-15.

 

Scheumann, M.; Linn, S.; Zimmermann, E. (2017). Vocal greeting during mother-infant reunions in a nocturnal primate, the gray mouse lemur (Microcebus murinus). Scientific Reports 7: 10321. DOI: 10.1038/s41598-017-10417-8.

Cooperation Partners:

Prof. Coen Elemans (Institute of Biology, University of Southern Denmark, Odense, Denmark)

Prof. Tecumseh Fitch and Christian Herbst, PhD (Department of Cognitive Biology, University of Vienna, Vienna, Austria)

Prof. Axel Zimmermann (University of Aalen, Aalen, Germany)

Dr. Roland Frey (Leibniz Institut für Zoo- und Wildtierforschung, Berlin, Germany)

Funding: VolkswagenStiftung, 6.569 EUR

Project Details:
The project aims to employ modern genetic tools to identify lemur populations of high conservation value to help prioritizing conservation efforts and to develop and implement conservation strategy for the most threatened and valuable lemur populations. The following points constitute the major project objectives: Objective 1: Identify and sample suitable populations of two lemur model species in the study region. Objective 2: Characterize the populations with regard to their genetic diversity, genetic uniqueness, and genetic connectivity to identify the site(s) with the highest conservation value and concern.

Cooperation Partners:

Dr. Fano Ratsoavina, Universität Antananarivo, Madagaskar

Jun.Prof. Helena Teixeira, PhD, Universität Montpellier, Frankreich

Funding: BMBF - DLR Projektträger, Teilprojekt aus dem BIODIVERSA Programm der EU, 301.195 EUR

Project Details:
The global biodiversity crisis that is affecting ecosystems worldwide is a major subject of concern and is expected to worsen with ongoing global changes. Climate change together with other anthropogenic factors will lead to the displacement of many favorable environments in the next decades owing to fast altitudinal and latitudinal shifts, with greatest predicted impacts in biodiversity hotspots. These shifts will lead to an increase in Habitat Loss and Fragmentation (HL&F), the main threats to Biodiversity worldwide. There is therefore a need to understand the consequences of HL&F, and to identify the barriers to gene flow at various spatial and temporal scales. We study HL&F in the context of past and future environmental changes, across taxa and regions. We use Madagascar as a model region and use comparative genomic analyses to infer generalizable critical features of ecological networks across various taxonomic and spatial scales. In particular, we identify barriers to gene flow based on genomic datasets and study the effects of forest fragmentation on the vegetation, and the abundance and parasite load of two mouse lemur and two rodent species.

Results:

Mercado-Malabet, F.; Ramsay, M.S.; Chell, C.; Andriatsitohaina, B.; Radespiel, U.; Lehman, S.M. (2024). Where the small things are: Modelling edge effects on mouse lemur population density and distribution in northwestern Madagascar. Am. J. Primatol., 87, e23621. https://doi.org/10.1002/ajp.23621.

 

Ramsay, M.S.; Sgarlata, G.; Barratt, C.D.; Salmona, J.; Andriatsitohaina, B.; Kiene, F.; Manzi, S.; Ramilison, M.L.; Rakotondravony, R.; Chikhi, L.; Lehman, S.M.; Radespiel, U. (2023): Effects of forest fragmentation on connectivity and genetic diversity in an endemic and an invasive rodent in northwestern Madagascar. Genes, 14(7), 1451. https://doi.org/10.3390/genes14071451.

 

Kiene, F.; Springer, A.; Andriatsitohaina, B.; Ramsay, M.S.; Rakotondravony, R.; Strube, C.*; Radespiel, U.* (2023): Filarial infections in lemurs: Evidence for a wide geographical distribution and low host specificity among lemur species. Am. J. Primatol., 85(2), e23458. DOI: 10.1002/ajp.23458 (*: joint senior authors)

 

Kiene, F.; Antriatsitohaina B.; Ramsay, M.S.; Rakotondravony, R.; Strube, C.*; Radespiel, U.* (2021): Habitat fragmentation and vegetation structure impact gastrointestinal parasites of small mammalian hosts in Madagascar. Ecology and Evolution 11, 6766-6788. Doi: 10.1002/ece3.7526.

 

Andriatsitohaina, B.; Romero-Mujalli, D.; Ramsay, M.S.; Kiene, F.; Rasoloharijaona, S.; Rakotondravony, R.; Lehman, S.M.; Radespiel, U. (2020): Effects of habitat edges on vegetation structure and the vulnerable golden-brown mouse lemur (Microcebus ravelobensis) in northwestern Madagascar. BMC Ecology 20, 69. https://doi.org/10.1186/s12898-020-00337-z.

Cooperation Partners:

Dr. Lounès Chikhi, IGC, Oeiras, Portugal

Prof. Olivier Mazet, Universität Toulouse, Frankreich

Dr. Guillaume Besnard, Universität Toulouse, Frankreich

Dr. Jordi Salmona, Universität Toulouse, Frankreich

Prof. Shawn Lehman, Universität Toronto, Canada

Dr. Romule Rakotondravony, Universität Mahajanga, Madagaskar

Prof. Solofonirina Rasoloharijaona, Universität Mahajanga, Madagaskar

Travis Steffens, PhD, University of Guelph, Canada; Planet Madagascar

Funding: DFG, 299.200 EUR

Project Details:
Marked climatic oscillations between glacial and interglacial periods had worldwide consequences for vegetation as well as animal population dynamics. The importance of these shallow-time (on geological and evolutionary timescales) geographic dynamics for shaping current biodiversity and biogeography patterns is increasingly stressed, although rarely analyzed in an innovative integrated manner. One of the necessary steps in order to understand the drivers of biodiversity is to synergize the efforts from various research fields by, for example, reconstructing the interplay between the degree and frequency of historic forest cover changes and demographic changes of forest-dependent organisms. This study aims to integrate validated records of vegetation and climate dynamics with inferred population dynamics to reconstruct the dynamics of forest landscapes and of populations of forest dwelling species over space and time in a primate model endemic to Madagascar. Madagascar developed a unique biodiversity during its long isolated history. Despite the long-lasting interest in the natural history of the island, much is still unknown about the biodiversity dynamics and long-term ecology of this continental island. This multidisciplinary project aims to integrate demographic inferences based on molecular datasets of mouse lemurs with validated high resolution vegetation dynamics based on paleoecological reconstructions obtained from the same study sites reaching back to the Last Glacial Maximum (LGM). To reach these goals, study sites in northwestern and northern Madagascar were visited for the joint collection of (paleo)ecological and population datasets and samples of mouse lemurs in direct vicinity to each other. For the paleoecological part sediment cores from lakes were drilled and complemented with samples of modern pollen rain and vegetation data. The sediment cores are subjected to temporal high-resolution pollen and charcoal analyses, radiocarbon dating and multivariate modelling of the vegetation and climate dynamics over time and space. The lemur samples are analyzed by applying RADSeq and NextSeq sequencing techniques on various subsets of samples. This study will contribute substantially to a deeper understanding of the evolutionary history and future prospects of lemur populations in view of ongoing habitat fragmentation and future climate change.

Results:

Montade, V.; Bremond, L.; Teixeira, H.; Kasper, T.; Daut, G.; Rasoamanana, E.; Pamavovolona, P.; Favier, C.; Arnaud, F., Radespiel, U.; Behling, H. (2024): Montane rain forest dynamics under changes in climate and human impact during the past millennia in northern Madagascar. R. Soc. Open Science, 11, 230930. https://doi.org/10.1098/rsos.230930.

 

Teixeira, H; Salmona, J; Arredondo, A.; Mourato, B; Manzi, S.; Rakotondravony, R.; Mazet, O; Chikhi, L.; Metzger, J; Radespiel, U. (2021): Impact of model assumptions on demographic inferences - the case study of two sympatric mouse lemurs in northwestern Madagascar. BMC Ecol. Evol. 21, 197. https://doi.org/10.1186/s12862-021-01929-z.

 

Teixeira, H.; Montade, V.; Salmona, J.; Metzger, J.; Bremond, L.; Kasper, T.; Daut, G.; Rouland, S.; Ranarilalatiana, S.; Rakotondravony, R.; Chikhi, L.; Behling, H.; Radespiel, U. (2021): Past environmental changes affected lemur population dynamics prior to human impact in Madagascar. Comm. Biol. 4, 1084. https://doi.org/10.1038/s42003-021-02620-1.

Cooperation Partners:

Jun.prof. Helena Teixeira, PhD Universität Montpellier, Frankreich

Prof. Hermann Behling, Universität Göttingen

Dr. Vincent Montade, Universität Montpellier, Frankreich

Dr. Lounès Chikhi, Universität Toulouse, Frankreich

Dr. Jordi Salmona, Universität Toulouse, Frankreich

Prof. Solofonirina Rasoloharijaona, Universität Mahajanga, Madagaskar

Dr. Romule Rakotondravony, Universität Mahajanga, Madagaskar

Project Details:
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Cooperation Partners:

Zentrum für systemische Neurowissenschaften (ZSN), Hannover

Institut für Neuroimmunologie und Multiple-Sklerose-Forschung (IMSF) der Universitätsmedizin Göttingen, Göttingen

Funding: Bundesministerium für Gesundheit, 909.181 EUR

Project Details:
Mit Schreiben vom 15. Dezember 2015 hat die WHO unter der Referenznummer DEU-134 das Institut für Biometrie, Epidemiologie und Informationsverarbeitung an der Tierärztlichen Hochschule Hannover als "WHO Collaborating Centre for Rese-arch and Training for Health at the Human-Animal-Environment Interface" (WHO CC HAEI) designiert. Das WHO-Zentrum unterstützt auch weiterhin die WHO und ihre Mitgliedsstaaten. Die neue Designationperiode läuft nun für weitere zwei Jahre bis zum 17. Dezember 2023.
Der Aufgabenbereich (Terms of Reference, ToR) für das WHO CC HAEI wurde auf-grund der Umstrukturierung der AMR-Division neu formuliert. Seit dem 18. De-zember 2021 bis zum Ende der Designationperiode finden die Aufgabenbereiche TOR (i) und TOR (II) wie folgt Anwendung:
TOR (i) Unterstützung der WHO und ihrer Mitgliedsstaaten bei der Entwicklung und Umsetzung von GLASS ("Global Antimicrobial Surveillance System") unter der Lei-tung der WHO.
TOR (ii) Ausweitung des Konzepts für das "Tricycle"-Projekt zur Schließung der Übertragungslücke zwischen Antibiotikaresistenzen beim Menschen und beim Tier unter der Leitung der WHO.

Cooperation Partners:

AMR Division, World Health Organization (WHO), Genf, Schweiz (weitere Informationen siehe https://www.who.int/health-topics/antimicrobial-resistance)

Project Details:
Gap junctions (Gj) are composed of two hemichannels called connexons, which are responsible for direct intercellular communication between adjoining cells. Each cell contains one connexon, composed of six connexin (cx) proteins. The so far discovered functions of Gj are mostly limited to the transport of molecules and ions (< 1 kDa). Nevertheless these junctions tend to be selective and specialize in cellular growth and differentiation (Bruzzone et al., 1996; Kumar and Gilula, 1996). As of today there are at least twenty different cx genes coding for Gj in humans and mice. One of the most researched Gj proteins is Cx43. In the testis, Cx43 is located between two Sertoli cells (SC) and between SC and germ cells (GC), it is involved in testicular development, GC and SC differentiation and spermatogenesis. SC nurture the developing GC and aid in their translocation and development from the basal to the adluminal compartment of the seminiferous tubule. Cx43 is further participating in blood-testis barrier formation and composition together with tight and adherens junctions as member of the "SC-SC junctional complexes" (Carrette et al., 2010).
A conditional SC-specific knockout (KO) of the Gja1 gene (SCCx43KO) revealed Cx43 expression in SC as an absolute requirement for normal testicular development and initiation of spermatogenesis (Brehm et al., 2007; Sridharan et al., 2007). Adult SCCx43KO mice showed normal testis descent, but testis size and weight was drastically lower when compared with heterozygous and WT littermates. Histological analysis revealed that SC specific deletion of Cx43 mostly results in an arrest of spermatogenesis at the level of spermatogonia or SC-only syndrome, intratubular cell clusters, abnormal SC cytoplasmic vacuoles, increased SC numbers and reduced number of spermatogonia per seminiferous tubule. Furthermore, as SCs were found to be still proliferating in adult mice (Sridharan et al., 2007), it was postulated that lack of Cx43 expression in SCs caused these somatic cells to remain in an apparently permanent proliferative state. These results emphasize the critical contribution of Cx43 to the normal maturational progression of SCs which normally results in the cessation of SC mitogenesis during the pubertal period.
Thus, as of today only one mouse stem with SCCx43KO-/- has been established in vivo (Brehm et al., 2007; Sridharan et al., 2007), yet no successful in vitro culturization of a &#61508;Cx43 SC line has been published. Although Carette et al. (2010) were successful in a partial inhibition of the Gj through siRNAs, a complete in vitro knockout may provide beneficial results in understanding the roles of Cx43 for normal spermatogenesis and may help to develop a mechanistic hypothesis in understanding the altered functions of Cx43 in SC leading to impaired spermatogenesis.

Project Details:
In diesem Projekt werden in einem transgenen Mausmodell die Folgen einer Sertoli Zell-spezifischen Deletion des Connexin43-Gens auf die Regulation der Spermatogenese u.a. mittels Microarray und qRT-PCR untersucht. Ausgewählte signifikant veränderte Kandidatengene aus den Mausversuchen werden zudem mit Hodenbiopsien von infertilen Männern verglichen.
Das Projekt bildet die Grundlage verschiedener Forschungsprojekte und Dissertationen sowie künftiger Drittmittelprojekte.
Geldgeber:
DFG, Klinische Forschergruppe KFO181, Male factor infertility due to impaired spermatogenesis
Volumen: 250000 €

Results:

https://www.sciencedirect.com/science/article/pii/S1642431X17302371?via%3Dihub

Cooperation Partners:

Dr. Daniela Fietz, JLU Giessen

Klinische Forschergruppe Giessen + Marburg

http://www.uni-giessen.de/cms/fbz/fb11/forschung/forschergruppen/kfo_181/home