Recent Submissions

  • Journal Article

    Emulating Dendritic Computing Paradigms on Analog Neuromorphic Hardware 

    Kaiser, Jakob; Billaudelle, Sebastian; Müller, Eric; Tetzlaff, Christian; Schemmel, Johannes; Schmitt, Sebastian
    Neuroscience
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  • Journal Article

    Tight bounds on missing late veneer in early Archean peridotite from triple oxygen isotopes 

    Peters, S.T.M.; Fischer, M.B.; Pack, A.; Szilas, K.; Appel, P.W.U.; Münker, C.; Dallai, L.; Marien, C.S.
    Geochemical Perspectives Letters 2021; 18 p.27-31
    Oxygen isotopes provide a unique possibility to study Earth’s late accretion phase from a lithophile element perspective, because most carbonaceous chondrites – meteorites that likely resemble the composition of the terrestrial late veneer – have markedly different Δ′17O values than the silicate Earth. Ultramafic rocks in the early Archean assemblage of southwest Greenland have not incorporated the full amount of late accreted materials, and therefore possibly record the Δ′17O of the mantle before late accretion. We measured 17O/16O and 18O/16O ratios of olivine from these ultramafic rocks and compared them with olivine from post-Archean mantle peridotite. A missing late veneer component was not resolved. The missing component from the early Archean mantle is therefore restricted to ≤0.12 % of Earth’s mass (M⊕) for most carbonaceous chondrite-like materials, unless the missing component resembles CI chondrites – the only carbonaceous chondrites with Δ′17O values similar to those of the silicate Earth. If the early Archean mantle had incorporated 60 % late veneer, the overall late accreted mass would be restricted to ≤0.3 % M⊕ for most types of carbonaceous chondrites, with a more massive late veneer only possible for CI-like chondrites.
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  • Journal Article

    Stabilizing P≡P: P22–, P2⋅–, and P20 as bridging ligands 

    Sun, Jian; Verplancke, Hendrik; Schweizer, Julia I.; Diefenbach, Martin; Würtele, Christian; Otte, Matthias; Tkach, Igor; Herwig, Christian; Limberg, Christian; Demeshko, Serhiy; et al.
    Holthausen, Max C.Schneider, Sven
    Chem 2021; 7(7) p.1952-1962
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  • Journal Article

    The Evolutionary History, Diversity, and Ecology of Willows (Salix L.) in the European Alps 

    Wagner, Natascha D.; He, Li; Hörandl, Elvira
    Diversity 2021; 13(4): Art. 146
    The genus Salix (willows), with 33 species, represents the most diverse genus of woody plants in the European Alps. Many species dominate subalpine and alpine types of vegetation. Despite a long history of research on willows, the evolutionary and ecological factors for this species richness are poorly known. Here we will review recent progress in research on phylogenetic relationships, evolution, ecology, and speciation in alpine willows. Phylogenomic reconstructions suggest multiple colonization of the Alps, probably from the late Miocene onward, and reject hypotheses of a single radiation. Relatives occur in the Arctic and in temperate Eurasia. Most species are widespread in the European mountain systems or in the European lowlands. Within the Alps, species differ ecologically according to different elevational zones and habitat preferences. Homoploid hybridization is a frequent process in willows and happens mostly after climatic fluctuations and secondary contact. Breakdown of the ecological crossing barriers of species is followed by introgressive hybridization. Polyploidy is an important speciation mechanism, as 40% of species are polyploid, including the four endemic species of the Alps. Phylogenomic data suggest an allopolyploid origin for all taxa analyzed so far. Further studies are needed to specifically analyze biogeographical history, character evolution, and genome evolution of polyploids.
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  • Journal Article

    Influence of the ABC Transporter YtrBCDEF of Bacillus subtilis on Competence, Biofilm Formation and Cell Wall Thickness 

    Benda, Martin; Schulz, Lisa Maria; Stülke, Jörg; Rismondo, Jeanine
    Frontiers in Microbiology 2021; 12: Art. 587035
    Bacillus subtilis develops genetic competence for the uptake of foreign DNA when cells enter stationary phase and a high cell density is reached. These signals are integrated by the competence transcription factor ComK, which is subject to transcriptional, post-transcriptional and post-translational regulation. Many proteins are involved in the development of competence, both to control ComK activity and to mediate DNA uptake. However, for many proteins, the precise function they play in competence development is unknown. In this study, we assessed whether proteins required for genetic transformation play a role in the activation of ComK or rather act downstream of competence gene expression. While these possibilities could be distinguished for most of the tested factors, we assume that two proteins, PNPase and the transcription factor YtrA, are required both for full ComK activity and for the downstream processes of DNA uptake and integration. Further analyses of the role of the transcription factor YtrA for the competence development revealed that the overexpression of the YtrBCDEF ABC transporter in the ytrA mutant causes the loss of genetic competence. Moreover, overexpression of this ABC transporter also affects biofilm formation. Since the ytrGABCDEF operon is naturally induced by cell wall-targeting antibiotics, we tested the cell wall properties upon overexpression of the ABC transporter and observed an increased thickness of the cell wall. The composition and properties of the cell wall are important for competence development and biofilm formation, suggesting that the observed phenotypes are the result of the increased cell wall thickness as an outcome of YtrBCDEF overexpression.
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  • Journal Article

    Locust Hemolymph Conveys Erythropoietin-Like Cytoprotection via Activation of the Cytokine Receptor CRLF3 

    Knorr, Debbra Y.; Hartung, Denise; Schneider, Kristin; Hintz, Luzia; Pies, Hanna S.; Heinrich, Ralf
    Frontiers in Physiology 2021; 12: Art. 648245
    The cytokine receptor-like factor 3 (CRLF3) is an evolutionary conserved class 1 cytokine receptor present in all major eumetazoan groups. Endogenous CRLF3 ligands have not been identified and the physiological responses mediated by mammalian CRLF3 are poorly characterized. Insect CRLF3 is activated by erythropoietin (Epo) and several related molecules that protect mammalian neurons from stress-induced apoptosis. However, insects neither express Epo nor “classical” Epo receptor. Cell-protective effects of insect hemolymph have been described for several species. In this study, we explored the possibility that the endogenous CRLF3 ligand is contained in locust hemolymph. PCR analyses confirmed expression of crfl3-transcripts in neurons and hemocytes of Locusta migratoria and Tribolium castaneum. Survival of locust hemocytes in primary cultures was significantly increased by supplementation of culture medium with locust hemolymph serum. Locust primary neuron cultures were also protected by locust hemolymph, though preceding exposure to fetal bovine serum changed the hemolymph dose-dependency of neuroprotection. Direct comparison of 10% hemolymph serum with recombinant human Epo in its optimal neuroprotective concentration revealed equivalent anti-apoptotic effects on hypoxia-exposed locust neurons. The same concentration of locust hemolymph serum also protected hypoxia-exposed T. castaneum neurons. This indicates that the neuroprotective factor in locust hemolymph is sufficiently conserved in insects to allow activation of neuroprotective receptors in different species. Locust hemolymph-induced neuroprotection in both L. migratoria and T. castaneum was abolished after RNAi-mediated suppression of crlf3-expression. In summary, we report the presence of a conserved endogenous cytokine in locust hemolymph that activates CRLF3 and connected anti-apoptotic processes in hemocytes and neurons. Identification and characterization of the CRLF3 ligand will promote knowledge about cytokine evolution and may unravel cell-protective agents with potential clinical application.
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  • Journal Article

    Identification of Two Novel Peptides That Inhibit α-Synuclein Toxicity and Aggregation 

    Popova, Blagovesta; Wang, Dan; Rajavel, Abirami; Dhamotharan, Karthikeyan; Lázaro, Diana F.; Gerke, Jennifer; Uhrig, Joachim F.; Hoppert, Michael; Outeiro, Tiago F.; Braus, Gerhard H.
    Frontiers in Molecular Neuroscience 2021; 14: Art. 659926
    Aggregation of α-synuclein (αSyn) into proteinaceous deposits is a pathological hallmark of a range of neurodegenerative diseases including Parkinson’s disease (PD). Numerous lines of evidence indicate that the accumulation of toxic oligomeric and prefibrillar αSyn species may underpin the cellular toxicity and spread of pathology between cells. Therefore, aggregation of αSyn is considered a priority target for drug development, as aggregation inhibitors are expected to reduce αSyn toxicity and serve as therapeutic agents. Here, we used the budding yeast S. cerevisiae as a platform for the identification of short peptides that inhibit αSyn aggregation and toxicity. A library consisting of approximately one million peptide variants was utilized in two high-throughput screening approaches for isolation of library representatives that reduce αSyn-associated toxicity and aggregation. Seven peptides were isolated that were able to suppress specifically αSyn toxicity and aggregation in living cells. Expression of the peptides in yeast reduced the accumulation of αSyn-induced reactive oxygen species and increased cell viability. Next, the peptides were chemically synthesized and probed for their ability to modulate αSyn aggregation in vitro. Two synthetic peptides, K84s and K102s, of 25 and 19 amino acids, respectively, significantly inhibited αSyn oligomerization and aggregation at sub-stoichiometric molar ratios. Importantly, K84s reduced αSyn aggregation in human cells. These peptides represent promising αSyn aggregation antagonists for the development of future therapeutic interventions.
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  • Journal Article

    Repeated convergent evolution of parthenogenesis in Acariformes (Acari) 

    Pachl, Patrick; Uusitalo, Matti; Scheu, Stefan; Schaefer, Ina; Maraun, Mark
    Ecology and Evolution 2020; 11(1) p.321-337
    The existence of old species-rich parthenogenetic taxa is a conundrum in evolutionary biology. Such taxa point to ancient parthenogenetic radiations resulting in morphologically distinct species. Ancient parthenogenetic taxa have been proposed to exist in bdelloid rotifers, darwinulid ostracods, and in several taxa of acariform mites (Acariformes, Acari), especially in oribatid mites (Oribatida, Acari). Here, we investigate the diversification of Acariformes and their ancestral mode of reproduction using 18S rRNA. Because parthenogenetic taxa tend to be more frequent in phylogenetically old taxa of Acariformes, we sequenced a wide range of members of this taxon, including early-derivative taxa of Prostigmata, Astigmata, Endeostigmata, and Oribatida. Ancestral character state reconstruction indicated that (a) Acariformes as well as Oribatida evolved from a sexual ancestor, (b) the primary mode of reproduction during evolution of Acariformes was sexual; however, species-rich parthenogenetic taxa radiated independently at least four times (in Brachychthonioidea (Oribatida), Enarthronota (Oribatida), and twice in Nothrina (Oribatida), (c) parthenogenesis additionally evolved frequently in species-poor taxa, for example, Tectocepheus, Oppiella, Rostrozetes, Limnozetes, and Atropacarus, and (d) sexual reproduction likely re-evolved at least three times from species-rich parthenogenetic clusters, in Crotonia (Nothrina), in Mesoplophora/Apoplophora (Mesoplophoridae, Enarthronota), and in Sphaerochthonius/Prototritia (Protoplophoridae, Enarthronota). We discuss possible reasons that favored the frequent diversification of parthenogenetic taxa including the continuous long-term availability of dead organic matter resources as well as generalist feeding of species as indicated by natural variations in stable isotope ratios.
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  • Journal Article

    Life‐history dimensions indicate non‐random assembly processes in tropical island tree communities 

    Schrader, Julian; Craven, Dylan; Sattler, Cornelia; Cámara‐Leret, Rodrigo; Moeljono, Soetjipto; Kreft, Holger
    Ecography 2020; 44(3) p.469-480
    Community assembly processes on islands are often non-random. The mechanisms behind non-random assembly, however, are generally difficult to disentangle. Functional diversity in combination with a null model approach that accounts for differences in species richness among islands can be used to test for non-random assembly processes, but has been applied rarely to island communities. By linking functional diversity of trees on islands with a null model approach, we bridge this gap and test for the role of stochastic versus non-random trait-mediated assembly processes in shaping communities by studying functional diversity–area relationships. We measured 11 plant functional traits linked to species dispersal and resource acquisition strategies of 57 tree species on 40 tropical islands. We grouped traits into four life-history dimensions representing 1) dispersal ability, 2) growth strategy, 3) light acquisition and 4) nutrient acquisition. To test for non-random assembly processes, we used null models that account for differences in species richness among the islands. Our results reveal contrasting responses of the four life-history dimensions to island area. The dispersal and the growth strategy dimensions were underdispersed on smaller islands, whereas the light acquisition dimension was overdispersed. The nutrient acquisition dimension did not deviate from null expectations. With increasing island area, shifts in the strength of non-random assembly processes increased the diversity of dispersal and acquisition strategies in island communities. Our results suggest that smaller islands may be more difficult to colonize and provide more limited niche space compared to larger islands, whose tree communities are likely determined by stochastic processes and higher niche diversity. Our null model approach highlights that analyzing the functional diversity of different life-history dimensions provides a powerful framework to unravel community assembly processes on islands. These complex, non-random assembly processes are masked by measures of functional diversity that do not account for differences in species richness between islands.
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  • Journal Article

    Breeding system of diploid sexuals within the Ranunculus auricomus complex and its role in a geographical parthenogenesis scenario 

    Karbstein, Kevin; Rahmsdorf, Elisabeth; Tomasello, Salvatore; Hodač, Ladislav; Hörandl, Elvira
    Ecology and Evolution 2020; 10(24) p.14435-14450
    The larger distribution area of asexuals compared with their sexual relatives in geographical parthenogenesis (GP) scenarios has been widely attributed to the advantages of uniparental reproduction and polyploidy. However, potential disadvantages of sexuals due to their breeding system have received little attention so far. Here, we study the breeding system of five narrowly distributed sexual lineages of Ranunculus notabilis s.l. (R. auricomus complex) and its effects on outcrossing, inbreeding, female fitness, and heterozygosity. We performed selfing and intra- and interlineage crossings by bagging 481 flowers (59 garden individuals) followed by germination experiments. We compared seed set and germination rates, and related them to genetic distance and genome-wide heterozygosity (thousands of RADseq loci). Selfings (2.5%) unveiled a significantly lower seed set compared with intra- (69.0%) and interlineage crossings (69.5%). Seed set of intra- (65%) compared to interpopulation crossings (78%) was significantly lower. In contrast, all treatments showed comparable germination rates (32%–43%). Generalized linear regressions between seed set and genetic distance revealed positive relationships in general and between lineages, and a negative one within lineages. Seed set was the main decisive factor for female fitness. Germination rates were not related to genetic distance at any level, but were positively associated with heterozygosity in interlineage crossings. Experiments confirmed full crossability and predominant outcrossing among sexual R. notabilis s.l. lineages. However, up to 5% (outliers 15%–31%) of seeds were formed by selfing, probably due to semi-self-compatibility in a multi-locus gametophytic SI system. Less seed set in intrapopulation crossings, and higher seed set and germination rates from crossings of genetically more distant and heterozygous lineages (interlineage) indicate negative inbreeding and positive outbreeding effects. In GP scenarios, sexual species with small and/or isolated populations can suffer from decreased female fitness due to their breeding system. This factor, among others, probably limits range expansion of sexuals.
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  • Journal Article

    A global view on evidence‐based effectiveness of interventions used to protect livestock from wild cats 

    Khorozyan, Igor; Waltert, Matthias
    Conservation Science and Practice 2020; 3(2): Art. e317
    Rapid population declines of wild cats (family Felidae) are often related to widespread conflicts with people over the livestock depredation they are causing. In spite of increasing literature on wild felids, there is no overview on the evidence-based effectiveness of livestock protection interventions in reducing depredation inflicted by these animals. We collected and analyzed 92 cases from 57 publications describing the percentage of damage reduction from the application of 11 interventions to 10 felid species. We found that the effectiveness of interventions differed significantly between species. Interventions tested for cheetahs (Acinonyx jubatus), Iberian lynx (Lynx pardinus) and snow leopards (Panthera uncia) were very effective, reducing damage by 70–100% due to species shyness, good fit of interventions to these species and local conditions, and strong social involvement. The most variable and often the lowest effectiveness of interventions was found for leopard (Panthera pardus), puma (Puma concolor) and caracal (Caracal caracal), which are more common and tolerant to humans. In other felids, interventions were generally effective, but some of them reportedly failed because of local contexts and intervention performance. Much more effort is required to invigorate the research of intervention effectiveness in little studied species and regions.
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  • Journal Article

    In the shadows of snow leopards and the Himalayas: density and habitat selection of blue sheep in Manang, Nepal 

    Filla, Marc; Lama, Rinzin Phunjok; Ghale, Tashi Rapte; Signer, Johannes; Filla, Tim; Aryal, Raja Ram; Heurich, Marco; Waltert, Matthias; Balkenhol, Niko; Khorozyan, Igor
    Ecology and Evolution 2020; 11(1) p.108-122
    There is a growing agreement that conservation needs to be proactive and pay increased attention to common species and to the threats they face. The blue sheep (Pseudois nayaur) plays a key ecological role in sensitive high-altitude ecosystems of Central Asia and is among the main prey species for the globally vulnerable snow leopard (Panthera uncia). As the blue sheep has been increasingly exposed to human pressures, it is vital to estimate its population dynamics, protect the key populations, identify important habitats, and secure a balance between conservation and local livelihoods. We conducted a study in Manang, Annapurna Conservation Area (Nepal), to survey blue sheep on 60 transects in spring (127.9 km) and 61 transects in autumn (134.7 km) of 2019, estimate their minimum densities from total counts, compare these densities with previous estimates, and assess blue sheep habitat selection by the application of generalized additive models (GAMs). Total counts yielded minimum density estimates of 6.0–7.7 and 6.9–7.8 individuals/km2 in spring and autumn, respectively, which are relatively high compared to other areas. Elevation and, to a lesser extent, land cover indicated by the normalized difference vegetation index (NDVI) strongly affected habitat selection by blue sheep, whereas the effects of anthropogenic variables were insignificant. Animals were found mainly in habitats associated with grasslands and shrublands at elevations between 4,200 and 4,700 m. We show that the blue sheep population size in Manang has been largely maintained over the past three decades, indicating the success of the integrated conservation and development efforts in this area. Considering a strong dependence of snow leopards on blue sheep, these findings give hope for the long-term conservation of this big cat in Manang. We suggest that long-term population monitoring and a better understanding of blue sheep–livestock interactions are crucial to maintain healthy populations of blue sheep and, as a consequence, of snow leopards.
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  • Journal Article

    Direct and plant‐mediated effects of climate on bird diversity in tropical mountains 

    Vollstädt, Maximilian G. R.; Albrecht, Jörg; Böhning‐Gaese, Katrin; Hemp, Andreas; Howell, Kim M.; Kettering, Laura; Neu, Alexander; Neuschulz, Eike Lena; Quitián, Marta; Santillán, Vinicio E.; et al.
    Töpfer, TillSchleuning, MatthiasFritz, Susanne A.
    Ecology and Evolution 2020; 10(24) p.14196-14208
    Aim Although patterns of biodiversity across the globe are well studied, there is still a controversial debate about the underlying mechanisms and their generality across biogeographic scales. In particular, it is unclear to what extent diversity patterns along environmental gradients are directly driven by abiotic factors, such as climate, or indirectly mediated through biotic factors, such as resource effects on consumers. Location Andes, Southern Ecuador; Mt. Kilimanjaro, Tanzania. Methods We studied the diversity of fleshy-fruited plants and avian frugivores at the taxonomic level, that is, species richness and abundance, as well as at the level of functional traits, that is, functional richness and functional dispersion. We compared two important biodiversity hotspots in mountain systems of the Neotropics and Afrotropics. We used field data of plant and bird communities, including trait measurements of 367 plant and bird species. Using structural equation modeling, we disentangled direct and indirect effects of climate and the diversity of plant communities on the diversity of bird communities. Results We found significant bottom-up effects of fruit diversity on frugivore diversity at the taxonomic level. In contrast, climate was more important for patterns of functional diversity, with plant communities being mostly related to precipitation, and bird communities being most strongly related to temperature. Main conclusions Our results illustrate the general importance of bottom-up mechanisms for the taxonomic diversity of consumers, suggesting the importance of active resource tracking. Our results also suggest that it might be difficult to identify signals of ecological fitting between functional plant and animal traits across biogeographic regions, since different species groups may respond to different climatic drivers. This decoupling between resource and consumer communities could increase under future climate change if plant and animal communities are consistently related to distinct climatic drivers.
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  • Journal Article

    The AgTech Startup Perspective to Farmers Ex Ante Acceptance Process of Autonomous Field Robots 

    von Veltheim, Friedrich Rübcke; Heise, Heinke
    Sustainability 2020; 12(24)
    Autonomous vehicles not only provide a new impetus in the development of car models in the automotive industry—even in agriculture there has recently been talk of autonomous field robots (AFR). Great expectations are placed on these digital assistants from a wide variety of perspectives. However, it is still unclear whether they will make the transition from market niches to broad-based distribution. Apart from various factors, this depends on user acceptance of this new technology expected by the innovators, since this is likely to be essential for the further development of AFR. For this purpose, the ex ante user acceptance of farmers from the perspective of various AgTech startups with AFR involvement in Europe was investigated in this exploratory and qualitative study. The Technology Acceptance Model (TAM) served as the basis for the developed interview guideline. In summary, the results confirm that a variety of factors potentially influence farmer acceptance and AFR diffusion from the perspective of AgTech startups, with perceived usefulness being considered the main motivation for using AFR. The interviewed experts believe that AFR will initially be used in crops that have relatively high costs for crop protection treatments before becoming economically attractive for other crops. The basic prerequisite for a successful market launch is an adjustment of the legal framework, which sets standards in relation to AFR and thus, provides security in the production process. The results could support political decision-makers in dealing with this new technology and AFR manufacturers in the promotion of AFR.
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  • Journal Article

    <i>Sphaeropsis sapinea</i> found as symptomless endophyte in Finland 

    Terhonen, Eeva-Liisa; Babalola, Jumoke; Kasanen, Risto; Jalkanen, Risto; Blumenstein, Kathrin
    Silva Fennica 2021; 55(1)
    The aim of this study was to determine if the ascomycete fungus Sphaeropsis sapinea (Fr.) Dyko & B. Sutton (syn. Diplodia sapinea (Fr.) Fuckel) could be cultured from surface sterilized Scots pine twigs presenting the endophytic stage of this fungus. This fungus causes the disease called Diplodia tip blight in conifers. Symptoms become visible when trees have been weakened by abiotic stressors related to temperature, drought and hailstorms. The disease is rapidly increasing and is observed regularly in Scots pine (Pinus sylvestris L.) forests in Europe. Changes in climatic conditions will gradually increase the damage of this pathogen, because it is favored by elevated temperatures and additionally the host trees will be more susceptible due to related environmental stress. Diplodia tip blight is emerging towards Northern latitudes, thus, actions to monitor the spread of S. sapinea in pine-dominated forests should be undertaken in Finland. Our aim was to search for S. sapinea in Scots pine along a transect in Finland. Branch samples were collected from healthy Scots pine, fungal endophytes were isolated and morphologically identified. Sixteen S. sapinea strains were found from four Scots pine trees from two locations. This finding confirms that S. sapinea is found as an endophyte in healthy Scots pine in Finland.
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  • Journal Article

    Variation and conservation implications of the effectiveness of anti-bear interventions 

    Khorozyan, Igor; Waltert, Matthias
    Scientific Reports 2020; 10(1)
    Human-bear conflicts triggered by nuisance behaviour in public places and damage to livestock, crops, beehives and trees are among the main threats to bear populations globally. The effectiveness of interventions used to minimize bear-caused damage is insufficiently known and comparative reviews are lacking. We conducted a meta-analysis of 77 cases from 48 publications and used the relative risk of damage to compare the effectiveness of non-invasive interventions, invasive management (translocations) and lethal control (shooting) against bears. We show that the most effective interventions are electric fences (95% confidence interval = 79.2–100% reduction in damage), calving control (100%) and livestock replacement (99.8%), but the latter two approaches were applied in only one case each and need more testing. Deterrents varied widely in their effectiveness (13.7–79.5%) and we recommend applying these during the peak periods of damage infliction. We found shooting (− 34.2 to 100%) to have a short-term positive effect with its effectiveness decreasing significantly and linearly over time. We did not find relationships between bear density and intervention effectiveness, possibly due to differences in spatial scales at which they were measured (large scales for densities and local fine scales for effectiveness). We appeal for more effectiveness studies and their scientific publishing in regard to under-represented conflict species and regions.
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  • Journal Article

    Multiple loci linked to inversions are associated with eye size variation in species of the Drosophila virilis phylad 

    Reis, Micael; Wiegleb, Gordon; Claude, Julien; Lata, Rodrigo; Horchler, Britta; Ha, Ngoc-Thuy; Reimer, Christian; Vieira, Cristina P.; Vieira, Jorge; Posnien, Nico
    Scientific Reports 2020; 10(1)
    The size and shape of organs is tightly controlled to achieve optimal function. Natural morphological variations often represent functional adaptations to an ever-changing environment. For instance, variation in head morphology is pervasive in insects and the underlying molecular basis is starting to be revealed in the Drosophila genus for species of the melanogaster group. However, it remains unclear whether similar diversifications are governed by similar or different molecular mechanisms over longer timescales. To address this issue, we used species of the virilis phylad because they have been diverging from D. melanogaster for at least 40 million years. Our comprehensive morphological survey revealed remarkable differences in eye size and head shape among these species with D. novamexicana having the smallest eyes and southern D. americana populations having the largest eyes. We show that the genetic architecture underlying eye size variation is complex with multiple associated genetic variants located on most chromosomes. Our genome wide association study (GWAS) strongly suggests that some of the putative causative variants are associated with the presence of inversions. Indeed, northern populations of D. americana share derived inversions with D. novamexicana and they show smaller eyes compared to southern ones. Intriguingly, we observed a significant enrichment of genes involved in eye development on the 4th chromosome after intersecting chromosomal regions associated with phenotypic differences with those showing high differentiation among D. americana populations. We propose that variants associated with chromosomal inversions contribute to both intra- and interspecific variation in eye size among species of the virilis phylad.
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  • Journal Article

    A minimalist model to measure interactions between proteins and synaptic vesicles 

    Perego, Eleonora; Reshetniak, Sofiia; Lorenz, Charlotta; Hoffmann, Christian; Milovanović, Dragomir; Rizzoli, Silvio O.; Köster, Sarah
    Scientific Reports 2020; 10(1)
    Protein dynamics in the synaptic bouton are still not well understood, despite many quantitative studies of synaptic structure and function. The complexity of the synaptic environment makes investigations of presynaptic protein mobility challenging. Here, we present an in vitro approach to create a minimalist model of the synaptic environment by patterning synaptic vesicles (SVs) on glass coverslips. We employed fluorescence correlation spectroscopy (FCS) to measure the mobility of monomeric enhanced green fluorescent protein (mEGFP)-tagged proteins in the presence of the vesicle patterns. We observed that the mobility of all eleven measured proteins is strongly reduced in the presence of the SVs, suggesting that they all bind to the SVs. The mobility observed in these conditions is within the range of corresponding measurements in synapses of living cells. Overall, our simple, but robust, approach should enable numerous future studies of organelle-protein interactions in general.
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  • Journal Article

    Linking human male vocal parameters to perceptions, body morphology, strength and hormonal profiles in contexts of sexual selection 

    Schild, Christoph; Aung, Toe; Kordsmeyer, Tobias L.; Cardenas, Rodrigo A.; Puts, David A.; Penke, Lars
    Scientific Reports 2020; 10(1)
    Sexual selection appears to have shaped the acoustic signals of diverse species, including humans. Deep, resonant vocalizations in particular may function in attracting mates and/or intimidating same-sex competitors. Evidence for these adaptive functions in human males derives predominantly from perception studies in which vocal acoustic parameters were manipulated using specialist software. This approach affords tight experimental control but provides little ecological validity, especially when the target acoustic parameters vary naturally with other parameters. Furthermore, such experimental studies provide no information about what acoustic variables indicate about the speaker—that is, why attention to vocal cues may be favored in intrasexual and intersexual contexts. Using voice recordings with high ecological validity from 160 male speakers and biomarkers of condition, including baseline cortisol and testosterone levels, body morphology and strength, we tested a series of pre-registered hypotheses relating to both perceptions and underlying condition of the speaker. We found negative curvilinear and negative linear relationships between male fundamental frequency (fo) and female perceptions of attractiveness and male perceptions of dominance. In addition, cortisol and testosterone negatively interacted in predicting fo, and strength and measures of body size negatively predicted formant frequencies (Pf). Meta-analyses of the present results and those from two previous samples confirmed that fonegatively predicted testosterone only among men with lower cortisol levels. This research offers empirical evidence of possible evolutionary functions for attention to men’s vocal characteristics in contexts of sexual selection.
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  • Journal Article

    The WD40-protein CFAP52/WDR16 is a centrosome/basal body protein and localizes to the manchette and the flagellum in male germ cells 

    Tapia Contreras, Constanza; Hoyer-Fender, Sigrid
    Scientific Reports 2020; 10(1)
    Development of spermatozoa requires remodelling and formation of particular structures. In elongating spermatids, the transient microtubular manchette contributes to the formation of the head–tail coupling apparatus (HTCA) and the sperm tail. The HTCA derives from the centrosome in that the proximal centriole inserts into the nuclear indentation and the distal centriole gives rise to the sperm flagellum. Although impairments in the formation of HTCA and sperm tail cause male infertility their molecular constituents are only partially known. The WD40-protein CFAP52 is implicated in motile cilia, but its relevance for male germ cell differentiation is not known. Here we show that CFAP52 is widespread expressed and localizes to a subset of microtubular structures. In male germ cells, CFAP52 is a component of the transient manchette and the sperm tail. However, expression of Cfap52 is not restricted to motile cilia-bearing cells. In NIH3T3 cells, CFAP52 localizes to the centrosome, the basal body, and the mitotic spindle poles, but not to the primary cilium. Our results demonstrate that CFAP52 is not restricted to motile cilia but instead most likely functions in constituting the centrosome/basal body matrix and the sperm tail.
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