@article{TolayBuchberger2021, author = {Tolay, Nazife and Buchberger, Alexander}, title = {Comparative profiling of stress granule clearance reveals differential contributions of the ubiquitin system}, series = {Life Science Alliance}, volume = {4}, journal = {Life Science Alliance}, number = {5}, doi = {10.26508/lsa.202000927}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259810}, pages = {e202000927}, year = {2021}, abstract = {Stress granules (SGs) are cytoplasmic condensates containing untranslated mRNP complexes. They are induced by various proteotoxic conditions such as heat, oxidative, and osmotic stress. SGs are believed to protect mRNPs from degradation and to enable cells to rapidly resume translation when stress conditions subside. SG dynamics are controlled by various posttranslationalmodifications, but the role of the ubiquitin system has remained controversial. Here, we present a comparative analysis addressing the involvement of the ubiquitin system in SG clearance. Using high-resolution immuno-fluorescence microscopy, we found that ubiquitin associated to varying extent with SGs induced by heat, arsenite, H2O2, sorbitol, or combined puromycin and Hsp70 inhibitor treatment. SG-associated ubiquitin species included K48- and K63-linked conjugates, whereas free ubiquitin was not significantly enriched. Inhibition of the ubiquitin activating enzyme, deubiquitylating enzymes, the 26S proteasome and p97/VCP impaired the clearance of arsenite- and heat-induced SGs, whereas SGs induced by other stress conditions were little affected. Our data underline the differential involvement of the ubiquitin system in SG clearance, a process important to prevent the formation of disease-linked aberrant SGs.}, language = {en} } @article{ThornChaoGeorgievetal.2020, author = {Thorn, Simon and Chao, Anne and Georgiev, Konstadin B. and M{\"u}ller, J{\"o}rg and B{\"a}ssler, Claus and Campbell, John L. and Jorge, Castro and Chen, Yan-Han and Choi, Chang-Yong and Cobb, Tyler P. and Donato, Daniel C. and Durska, Ewa and Macdonald, Ellen and Feldhaar, Heike and Fontaine, Jospeh B. and Fornwalt, Paula J. and Hern{\´a}ndez Hern{\´a}ndez, Raquel Mar{\´i}a and Hutto, Richard L. and Koivula, Matti and Lee, Eun-Jae and Lindenmayer, David and Mikusinski, Grzegorz and Obrist, Martin K. and Perl{\´i}k, Michal and Rost, Josep and Waldron, Kaysandra and Wermelinger, Beat and Weiß, Ingmar and Zmihorski, Michal and Leverkus, Alexandro B.}, title = {Estimating retention benchmarks for salvage logging to protect biodiversity}, series = {Nature Communications}, volume = {11}, journal = {Nature Communications}, doi = {10.1038/s41467-020-18612-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230512}, year = {2020}, abstract = {Forests are increasingly affected by natural disturbances. Subsequent salvage logging, a widespread management practice conducted predominantly to recover economic capital, produces further disturbance and impacts biodiversity worldwide. Hence, naturally disturbed forests are among the most threatened habitats in the world, with consequences for their associated biodiversity. However, there are no evidence-based benchmarks for the proportion of area of naturally disturbed forests to be excluded from salvage logging to conserve biodiversity. We apply a mixed rarefaction/extrapolation approach to a global multi-taxa dataset from disturbed forests, including birds, plants, insects and fungi, to close this gap. We find that 757\% (mean +/- SD) of a naturally disturbed area of a forest needs to be left unlogged to maintain 90\% richness of its unique species, whereas retaining 50\% of a naturally disturbed forest unlogged maintains 73 +/- 12\% of its unique species richness. These values do not change with the time elapsed since disturbance but vary considerably among taxonomic groups. Salvage logging has become a common practice to gain economic returns from naturally disturbed forests, but it could have considerable negative effects on biodiversity. Here the authors use a recently developed statistical method to estimate that ca. 75\% of the naturally disturbed forest should be left unlogged to maintain 90\% of the species unique to the area.}, language = {en} } @article{StieglervonHoermannMuelleretal.2020, author = {Stiegler, Jonas and von Hoermann, Christian and M{\"u}ller, J{\"o}rg and Benbow, M. Eric and Heurich, Marco}, title = {Carcass provisioning for scavenger conservation in a temperate forest ecosystem}, series = {Ecosphere}, volume = {11}, journal = {Ecosphere}, number = {4}, doi = {10.1002/ecs2.3063}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-218054}, year = {2020}, abstract = {Carrion plays an essential role in shaping the structure and functioning of ecosystems and has far-reaching implications for biodiversity conservation. The change in availability and type of carcasses throughout ecosystems can involve negative effects for scavenging communities. To address this issue, there have been recent conservation management measures of carrion provision in natural systems. However, the optimal conditions under which exposing carcasses to optimize conservation outcomes are still limited. Here, we used camera traps throughout elevational and vegetational gradients to monitor the consumption of 48 deer carcasses over a study period of six years by evaluating 270,279 photographs resulting out of 15,373 trap nights. We detected 17 species visiting carcass deployments, including five endangered species. Our results show that large carcasses, the winter season, and a heterogeneous surrounding habitat enhanced the frequency of carcass visits and the species richness of scavenger assemblages. Contrary to our expectations, carcass species, condition (fresh/frozen), and provision schedule (continuous vs single exposure) did not influence scavenging frequency or diversity. The carcass visitation frequency increased with carcass mass and lower temperatures. The effect of large carcasses was especially pronounced for mesopredators and the Eurasian lynx (Lynx lynx). Lynx were not too influenced in its carrion acquisition by the season, but exclusively preferred remote habitats containing higher forest cover. Birds of prey, mesopredators, and top predators were also positively influenced by the visiting rate of ravens (Corvus corax), whereas no biotic or abiotic preferences were found for wild boars (Sus scrofa). This study provides evidence that any ungulate species of carrion, either in a fresh or in previously frozen condition, attracts a high diversity of scavengers especially during winter, thereby supporting earlier work that carcass provisions may support scavenger communities and endangered species.}, language = {en} } @phdthesis{Mody2003, author = {Mody, Karsten}, title = {Patterns of arthropod distribution and determinants of arthropod assemblage composition in a natural West African savannah}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-6202}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2003}, abstract = {This study investigated patterns of arthropod community organisation and the processes structuring these communities on a range of different tree species in a natural West African savannah (Como{\´e} National Park, C{\^o}te d'Ivoire). It described and analysed patterns of arthropod distribution on the level of whole communities, on the level of multiple-species interactions, and on the level of individual insect species. Community samples were obtained by applying (i) canopy fogging for mature individuals of three tree species (Anogeissus leiocarpa, Burkea africana, Crossopteryx febrifuga) and (ii) a modified beating technique allowing to sample the complete arthropod communities of the respective study plants for medium-sized (up to 3 m) individuals of two other species (Combretum fragrans, Pseudocedrela kotschyi). General information on ant-plant interactions was retrieved from ant community comparisons of the mature savannah trees. In addition, ant-ant, ant-plant and ant-herbivore interactions were studied in more detail considering the ant assemblages on the myrmecophilic tree Pseudocedrela kotschyi. Herbivore-plant interactions were investigated on a multiple-species level (interrelationships between herbivores and Pseudocedrela trees) and on a species level (detailed studies of interrelationships between herbivorous beetles and caterpillars and the host tree Combretum fragrans). The studies on individual herbivore species were complemented by a study on an abundant ant species, clarifying not only the relationship between host plant and associated animal but allowing also to look at interactive (competitive) aspects of community organisation. The study demonstrated for the first time that (i) the structure of beetle communities on tropical trees can be strongly dependent on the host tree species, (ii) individual trees can host specific arthropod communities whose characteristic structure is stable over years and is strongly determined by the individual tree's attributes, (iii) ants can express a pronounced fidelity to single leaves as foraging area and can thereby determine distribution patterns of other ants, (iv) intraspecifically variable palatability of plants for insect herbivores can be stable over years and can influence the distribution of herbivores that can distinguish between individual hosts according to palatability and (v) intraspecific host plant change can positively affect fitness of herbivores if host plant quality is variable. In general, the present study contributes to our knowledge of anthropogenically unaltered processes affecting community assembly in a natural environment. The fundamental understanding of these processes is crucial for the identification of anthropogenic alterations and the establishment of sustainable management measures. The study points out the important role local factors can play for the distribution of organisms and thereby for community organisation. It emphasises the relevance of small scale heterogeneity of the abiotic and biotic environment to biodiversity and the need to consider these factors for development of effective conservation and restoration strategies.}, subject = {Savanne}, language = {en} } @article{LevitisGouldvan PraagGauetal.2021, author = {Levitis, Elizabeth and Gould van Praag, Cassandra D and Gau, R{\´e}mi and Heunis, Stephan and DuPre, Elizabeth and Kiar, Gregory and Bottenhorn, Katherine L and Glatard, Tristan and Nikolaidis, Aki and Whitaker, Kirstie Jane and Mancini, Matteo and Niso, Guiomar and Afyouni, Soroosh and Alonso-Ortiz, Eva and Appelhoff, Stefan and Arnatkeviciute, Aurina and Atay, Selim Melvin and Auer, Tibor and Baracchini, Giulia and Bayer, Johanna M M and Beauvais, Michael J S and Bijsterbosch, Janine D and Bilgin, Isil P and Bollmann, Saskia and Bollmann, Steffen and Botvinik-Nezer, Rotem and Bright, Molly G and Calhoun, Vince D and Chen, Xiao and Chopra, Sidhant and Chuan-Peng, Hu and Close, Thomas G and Cookson, Savannah L and Craddock, R Cameron and De La Vega, Alejandro and De Leener, Benjamin and Demeter, Damion V and Di Maio, Paola and Dickie, Erin W and Eickhoff, Simon B and Esteban, Oscar and Finc, Karolina and Frigo, Matteo and Ganesan, Saampras and Ganz, Melanie and Garner, Kelly G and Garza-Villarreal, Eduardo A and Gonzalez-Escamilla, Gabriel and Goswami, Rohit and Griffiths, John D and Grootswagers, Tijl and Guay, Samuel and Guest, Olivia and Handwerker, Daniel A and Herholz, Peer and Heuer, Katja and Huijser, Dorien C and Iacovella, Vittorio and Joseph, Michael J E and Karakuzu, Agah and Keator, David B and Kobeleva, Xenia and Kumar, Manoj and Laird, Angela R and Larson-Prior, Linda J and Lautarescu, Alexandra and Lazari, Alberto and Legarreta, Jon Haitz and Li, Xue-Ying and Lv, Jinglei and Mansour L., Sina and Meunier, David and Moraczewski, Dustin and Nandi, Tulika and Nastase, Samuel A and Nau, Matthias and Noble, Stephanie and Norgaard, Martin and Obungoloch, Johnes and Oostenveld, Robert and Orchard, Edwina R and Pinho, Ana Lu{\´i}sa and Poldrack, Russell A and Qiu, Anqi and Raamana, Pradeep Reddy and Rokem, Ariel and Rutherford, Saige and Sharan, Malvika and Shaw, Thomas B and Syeda, Warda T and Testerman, Meghan M and Toro, Roberto and Valk, Sofie L and Van Den Bossche, Sofie and Varoquaux, Ga{\"e}l and V{\´a}ša, František and Veldsman, Michele and Vohryzek, Jakub and Wagner, Adina S and Walsh, Reubs J and White, Tonya and Wong, Fu-Te and Xie, Xihe and Yan, Chao-Gan and Yang, Yu-Fang and Yee, Yohan and Zanitti, Gaston E and Van Gulick, Ana E and Duff, Eugene and Maumet, Camille}, title = {Centering inclusivity in the design of online conferences—An OHBM-Open Science perspective}, series = {GigaScience}, volume = {10}, journal = {GigaScience}, doi = {10.1093/gigascience/giab051}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-371574}, pages = {1-14}, year = {2021}, abstract = {As the global health crisis unfolded, many academic conferences moved online in 2020. This move has been hailed as a positive step towards inclusivity in its attenuation of economic, physical, and legal barriers and effectively enabled many individuals from groups that have traditionally been underrepresented to join and participate. A number of studies have outlined how moving online made it possible to gather a more global community and has increased opportunities for individuals with various constraints, e.g., caregiving responsibilities. Yet, the mere existence of online conferences is no guarantee that everyone can attend and participate meaningfully. In fact, many elements of an online conference are still significant barriers to truly diverse participation: the tools used can be inaccessible for some individuals; the scheduling choices can favour some geographical locations; the set-up of the conference can provide more visibility to well-established researchers and reduce opportunities for early-career researchers. While acknowledging the benefits of an online setting, especially for individuals who have traditionally been underrepresented or excluded, we recognize that fostering social justice requires inclusivity to actively be centered in every aspect of online conference design. Here, we draw from the literature and from our own experiences to identify practices that purposefully encourage a diverse community to attend, participate in, and lead online conferences. Reflecting on how to design more inclusive online events is especially important as multiple scientific organizations have announced that they will continue offering an online version of their event when in-person conferences can resume.}, language = {en} } @article{KoetschanKittelmannLuetal.2014, author = {Koetschan, Christian and Kittelmann, Sandra and Lu, Jingli and Al-Halbouni, Djamila and Jarvis, Graeme N. and M{\"u}ller, Tobias and Wolf, Matthias and Janssen, Peter H.}, title = {Internal Transcribed Spacer 1 Secondary Structure Analysis Reveals a Common Core throughout the Anaerobic Fungi (Neocallimastigomycota)}, series = {PLOS ONE}, volume = {9}, journal = {PLOS ONE}, number = {3}, doi = {10.1371/journal.pone.0091928}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117058}, pages = {e91928}, year = {2014}, abstract = {The internal transcribed spacer (ITS) is a popular barcode marker for fungi and in particular the ITS1 has been widely used for the anaerobic fungi (phylum Neocallimastigomycota). A good number of validated reference sequences of isolates as well as a large number of environmental sequences are available in public databases. Its highly variable nature predisposes the ITS1 for low level phylogenetics; however, it complicates the establishment of reproducible alignments and the reconstruction of stable phylogenetic trees at higher taxonomic levels (genus and above). Here, we overcame these problems by proposing a common core secondary structure of the ITS1 of the anaerobic fungi employing a Hidden Markov Model-based ITS1 sequence annotation and a helix-wise folding approach. We integrated the additional structural information into phylogenetic analyses and present for the first time an automated sequence-structure-based taxonomy of the ITS1 of the anaerobic fungi. The methodology developed is transferable to the ITS1 of other fungal groups, and the robust taxonomy will facilitate and improve high-throughput anaerobic fungal community structure analysis of samples from various environments.}, language = {en} } @article{KesslerHertelJungkunstetal.2012, author = {Kessler, Michael and Hertel, Dietrich and Jungkunst, Hermann F. and Kluge, J{\"u}rgen and Abrahamczyk, Stefan and Bos, Merijn and Buchori, Damayanti and Gerold, Gerhard and Gradstein, S. Robbert and K{\"o}hler, Stefan and Leuschner, Christoph and Moser, Gerald and Pitopang, Ramadhanil and Saleh, Shahabuddin and Schulze, Christian H. and Sporn, Simone G. and Steffan-Dewenter, Ingolf and Tjitrosoedirdjo, Sri S. and Tscharntke, Teja}, title = {Can Joint Carbon and Biodiversity Management in Tropical Agroforestry Landscapes Be Optimized?}, series = {PLoS One}, volume = {7}, journal = {PLoS One}, number = {10}, doi = {10.1371/journal.pone.0047192}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-132016}, pages = {e47192}, year = {2012}, abstract = {Managing ecosystems for carbon storage may also benefit biodiversity conservation, but such a potential 'win-win' scenario has not yet been assessed for tropical agroforestry landscapes. We measured above-and below-ground carbon stocks as well as the species richness of four groups of plants and eight of animals on 14 representative plots in Sulawesi, Indonesia, ranging from natural rainforest to cacao agroforests that have replaced former natural forest. The conversion of natural forests with carbon stocks of 227-362 Mg C ha\(^{-1}\) to agroforests with 82-211 Mg C ha\(^{-1}\) showed no relationships to overall biodiversity but led to a significant loss of forest-related species richness. We conclude that the conservation of the forest-related biodiversity, and to a lesser degree of carbon stocks, mainly depends on the preservation of natural forest habitats. In the three most carbon-rich agroforestry systems, carbon stocks were about 60\% of those of natural forest, suggesting that 1.6 ha of optimally managed agroforest can contribute to the conservation of carbon stocks as much as 1 ha of natural forest. However, agroforestry systems had comparatively low biodiversity, and we found no evidence for a tight link between carbon storage and biodiversity. Yet, potential win-win agroforestry management solutions include combining high shade-tree quality which favours biodiversity with cacao-yield adapted shade levels.}, language = {en} } @phdthesis{Kaiser2014, author = {Kaiser, Dorkas}, title = {Termites and ants in BURKINA FASO (WEST AFRICA): taxonomic and functional diversity along land-use gradients; ecosystem services of termites in the traditional ZA{\"I} SYSTEM}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-107001}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2014}, abstract = {The consequences of habitat change for human well-being are assumed to be especially extreme in Burkina Faso. The country is located in a highly drought-sensitive zone of West Africa, and small-scale subsistence farmers may be especially affected if losses of biodiversity lead to changes in ecosystem functioning; many depend on more or less degraded lands for agricultural production. The overall aim of the present thesis consequently was to characterize the functional traits of soil-organisms which are crucial for a productive and balanced soil environment in the study region - termites and ants. They are true ecosystem engineers whose activity alters the habitat. Through soil-turnover in the course of constructing biogenic structures of varying size and nature (mounds, nests, galleries, soil-sheetings, foraging-holes), they bioturbate huge amounts of soil masses and exert massive effects on soil structure, positively influencing the fertility, stability, aeration and water infiltration rate into soils; and they provide habitats for other species. In sub-Saharan Africa, ants and termites are the only active soil macrofauna during the long dry season; in the sub-Sahel zone of Burkina Faso, termites even represent the only active, quantitatively remarkable decomposers all year round. Since no information was available about the actual diversity of the focal arthropods, I divided the thesis in two main parts: In the first part, a baseline study, I assessed the local termite and ant fauna, and investigated their quantitative and qualitative response to changing habitat parameters resulting from increasing human impact ('functional response traits'). In the second and applied part, I addressed the impact of the biogenic structures which are important for the restoration of degraded soils ('functional effect traits'). Two traditional agricultural systems characteristic for the study region were selected. Each system represented a land-use intensification gradient comprising four distinct habitats now differing in the magnitude of human intervention but formerly having the same initial state. The first disturbance gradient, the temporal cross-section of a traditional soil water conservation technique to restore degraded heavily encrusted, barren soil named Za{\"i} in Ouahigouya (Yatenga province, sub-Sahel zone); the second disturbance gradient, an agriculture type using crop rotation and fallow as nutrient management techniques near Fada N'Gourma (Gourma province, North-Sudanese zone). No standard protocol existed for the assessment of termite and ant diversity in semi-arid (agro-) ecosystems; two widely accepted standard protocols provided the basis for the newly revised and combined rapid assessment protocol 'RAP': the ALL protocol for leaf litter ants of Agosti and Alonso (2000), and the transect protocol for termites in tropical forests of Jones and Eggleton (2000). In each study site, three to four replicate transects were conducted during the rainy seasons (2004—2008). The RAP-protocol turned out to be very effective to characterize, compare and monitor the taxonomic and functional diversity of termites and ants; between 70\% and 90\% of the estimated total species richness were collected on all levels (transects, habitats, regions). Together in both regions, 65 ant species (25 genera) and 39 termite species (13 genera) were collected. These findings represent the first records for Burkina Faso. The data indicate a high sensitivity of termites and ants to land-use intensification. The diversity strongly decreased with increasing anthropogenic impact in the North-Sudan region. In total, 53 ant species (23 genera) and 31 termite species (12 genera) were found. Very promising results concerning the recovery potential of the soil-arthropods' diversity were gathered in the Za{\"i} system. The diversity of both taxa strongly increased with increasing habitat rehabilitation - in total, 41 ant species (16 genera) and 33 termite species (11 genera) were collected. For both taxa significant differences could be noted in the shape of the density variations along the gradient. For instance termites: Fungus-growers showed the greatest adaptability to different management practices. The greatest variations between the habitats were observed in soil and grass-feeding termites. Whole functional groups were missing in heavily impacted habitats, e.g. soil-, grass-, and wood-feeders were absent in the degraded site in the sub-Sahel zone. Several environmental parameters could be identified which significantly explained a great part of the variations in the composition of the arthropods' communities; they indicate the importance of the habitats' structural complexity (vegetation structure) and concomitant effects on diurnal temperature and moisture fluctuations, the availability of food sources, and the soil-structure. The diversity of termites in the sub-Sahel region was strongly correlated with the crown-cover percentages, the topsoils' sand-content, and the availability of litter; in the North-Sudan region with the cumulated woody plant basal area, the topsoils' clay- and organic matter-content. The parameters identified for ant communities in the Za{\"i} system, were the height of trees, the topsoils' clay-content and air humidity; in the North-Sudan region the habitats' crown-cover percentages, the quantity of litter and again the height of trees. In the second part of the thesis, I first rapidly assessed the (natural) variations in the amount of epigeal soil-structures along the two disturbance gradients in order to judge the relative importance of termites and ants for soil-turnover. The results illustrated impressively that a) in all study sites, termites were the main bioturbators while ant structures were of minor importance for soil turn-over; b) earthworms and grass-feeding termites contributed significantly to soil turn-over in the more humid North-Sudan region; and c) the bioturbated soil mass varied between seasons and years, however, the relative importance of the different taxa seemed to be fairly constant. In the sub-Sahel zone, fungus-growing Odontotermes and Macrotermes species fully take over the important function of bioturbation, leading to the transport of huge amounts of fine-textured soil material to the surface; with increasing habitat restoration, coarse fragments decreased in the upper horizons and became concentrated deeper along the soil profile. Consequently, in the applied part, I concentrated on the bioturbation activity of fungus-growing termites in the four main stages of the Za{\"i} system: crusted bare soil (initial stage), millet field, young and old forest. In each of the four Za{\"i} sites nine experimental blocks (each comprising four plots of 1m2) were used to stimulate the foraging activity of fungus-growing termites with different, locally available organic materials (Aristida kerstingii hay, Bombax costatum wooden blocks, compost and a control without any organic amendment). The experiment was conducted twice for the duration of four weeks (rainy season 2005, dry season 2006). The plots were regularly checked and the increase of the area covered by sheetings chronologically followed. After four weeks a) all sheeting-soil was collected, air dried and separately weighed according to the different genera, and b) the foraging-holes were counted and their diameter measured. Additionally, c) ponded water infiltration was measured in selected plots, and d) the physicochemical properties of sheeting-soil were analyzed. In case of complete consumption of the offered hay during the experimental 4-weeks-duration, the same procedure (a, b) was followed before adding new hay to the respective plot. The comparison between the different plots, sites and seasons revealed clearly that hay was the most attractive bait; for each gram of hay removed, Odontotermes brought about 12 g soil to the surface, Macrotermes 4 g. Odontotermes was the only genus attracted by organic material to the degraded area, and was therefore the decisive primary physical ecosystem engineer in the Za{\"i} system, initiating the restoration process. The mass of soil bioturbated in the course of foraging increased strongly from the degraded, barren towards the most rehabilitated reforested site. Combining all 36 experimental plots per Za{\"i} stage, Odontotermes bioturbated 31.8 tons of soil per hectare and month dry season in the degraded area, and 32.4 tons ha-1 mon-1 in the millet fields; both genera moved 138.9 tons ha-1 mon-1 in the young and 215.5 tons ha-1 mon-1 in the old Za{\"i} forest. Few comparable figures were found in the literature. In northern Burkina Faso, both genera constructed 20 tons of sheetings ha-1 mon-1 after mulching with a straw-wood mixture (Mando \& Miedema 1997), and in Senegal, around 10 tons ha-1 mon-1 were moved in heavily foraged plots (Rouland et al. 2003). Within a site, soil turn-over and the number of foraging holes created was always highest in hay, followed by compost, then by wood and in the end control. The fungus-growers' foraging-activity was leading to an enormous increase in surface pore space - after one month of induced foraging activity in hay-plots, the median number of foraging-holes increased from 142 m-2 in the degraded site up to 921 m-2 in the old Za{\"i} forest. The creation of subterranean galleries and macropores significantly increased the water infiltration rate by a mean factor 2-4. Laboratory analyses revealed that sheeting-soil differed strongly from the respective control soil as well as between the seasons, the food-type covered, and the two genera. Odontotermes-sheetings differed in more parameters than Macrotermes-sheetings, and dry season sheetings differed in more parameters (and more strongly) than rainy season sheetings. In the present study, soil organic matter, carbon and nitrogen contents were significantly increased in all dry season sheetings; in the rainy season mainly in those built on compost. Texture analysis pointed out that both genera used topsoil and soil from deeper horizons in varying mixture ratios, thereby supporting findings of Jouquet et al. (2006). To summarize, the present thesis contributes to a better understanding of the functional response traits of termites and ants to changing environmental parameters resulting from increasing human impact. The RAP-protocol represents an easy-to-learn and very effective method to representatively characterize, compare and monitor the taxonomic and functional diversity of termites and ants. The experiment has provided conclusive evidence of the importance of the consideration of fungus-growing termites (particularly Odontotermes and Macrotermes species) when aiming to restore infertile, degraded and crusted soils and to maintain a sustainable agricultural production in the Sahel-Sudanese zone of West Africa.}, subject = {Termiten}, language = {en} } @phdthesis{Jacobs2011, author = {Jacobs, Graeme Brendon}, title = {HIV-1 resistance analyses from therapy-na{\"i}ve patients in South Africa, Tanzania and the characterization of a new HIV-1 subtype C proviral molecular clone}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-67319}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2011}, abstract = {The acquired immunodeficiency syndrome (AIDS) is currently the most infectious disease worldwide. It is caused by the human immunodeficiency virus (HIV). At the moment there are ~33.3 million people infected with HIV. Sub-Saharan Africa, with ~22.5 million people infected accounts for 68\% of the global burden. In most African countries antiretroviral therapy (ART) is administered in limited-resource settings with standardised first- and second-line ART regimens. During this study I analysed the therapy-na{\"i}ve population of Cape Town, South Africa and Mwanza, Tanzania for any resistance associated mutations (RAMs) against protease inhibitors, nucleoside reverse transcriptase inhibitors and non-nucleoside reverse transcriptase inhibitors. My results indicate that HIV-1 subtype C accounts for ~95\% of all circulating strains in Cape Town, South Africa. I could show that ~3.6\% of the patient derived viruses had RAMs, despite patients being therapy-na{\"i}ve. In Mwanza, Tanzania the HIV drug resistance (HIVDR) prevalence in the therapy-na{\"i}ve population was 14.8\% and significantly higher in the older population, >25 years. Therefore, the current WHO transmitted HIVDR (tHIVDR) survey that is solely focused on the transmission of HIVDR and that excludes patients over 25 years of age may result in substantial underestimation of the prevalence of HIVDR in the therapy-na{\"i}ve population. Based on the prevalence rates of tHIVDR in the study populations it is recommended that all HIV-1 positive individuals undergo a genotyping resistance test before starting ART. I also characterized vif sequences from HIV-1 infected patients from Cape Town, South Africa as the Vif protein has been shown to counteract the antiretroviral activity of the cellular APOBEC3G/F cytidine deaminases. There is no selective pressure on the HIV-1 Vif protein from current ART regimens and vif sequences was used as an evolutionary control. As the majority of phenotypic resistance assays are still based on HIV-1 subtype B, I wanted to design an infectious HIV-1 subtype C proviral molecular clone that can be used for in vitro assays based on circulating strains in South Africa. Therefore, I characterized an early primary HIV-1 subtype C isolate from Cape Town, South Africa and created a new infectious subtype C proviral molecular clone (pZAC). The new pZAC virus has a significantly higher transient viral titer after transfection and replication rate than the previously published HIV-1 subtype C virus from Botswana. The optimized proviral molecular clone, pZAC could be used in future cell culture and phenotypic HIV resistance assays regarding HIV-1 subtype C.}, subject = {HIV}, language = {en} } @article{IsaacsMikasiObasaetal.2020, author = {Isaacs, Darren and Mikasi, Sello Given and Obasa, Adetayo Emmanuel and Ikomey, George Mondinde and Shityakov, Sergey and Cloete, Ruben and Jacobs, Graeme Brendon}, title = {Structural comparison of diverse HIV-1 subtypes using molecular modelling and docking analyses of integrase inhibitors}, series = {Viruses}, volume = {12}, journal = {Viruses}, number = {9}, issn = {1999-4915}, doi = {10.3390/v12090936}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-211170}, year = {2020}, abstract = {The process of viral integration into the host genome is an essential step of the HIV-1 life cycle. The viral integrase (IN) enzyme catalyzes integration. IN is an ideal therapeutic enzyme targeted by several drugs; raltegravir (RAL), elvitegravir (EVG), dolutegravir (DTG), and bictegravir (BIC) having been approved by the USA Food and Drug Administration (FDA). Due to high HIV-1 diversity, it is not well understood how specific naturally occurring polymorphisms (NOPs) in IN may affect the structure/function and binding affinity of integrase strand transfer inhibitors (INSTIs). We applied computational methods of molecular modelling and docking to analyze the effect of NOPs on the full-length IN structure and INSTI binding. We identified 13 NOPs within the Cameroonian-derived CRF02_AG IN sequences and further identified 17 NOPs within HIV-1C South African sequences. The NOPs in the IN structures did not show any differences in INSTI binding affinity. However, linear regression analysis revealed a positive correlation between the Ki and EC50 values for DTG and BIC as strong inhibitors of HIV-1 IN subtypes. All INSTIs are clinically effective against diverse HIV-1 strains from INSTI treatment-na{\"i}ve populations. This study supports the use of second-generation INSTIs such as DTG and BIC as part of first-line combination antiretroviral therapy (cART) regimens, due to a stronger genetic barrier to the emergence of drug resistance.}, language = {en} }