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311.
We investigated a community of syntopically occurring horseshoe bats (Rhinolophus hipposideros, R. euryale, R. ferrumequinum) in southern Slovakia. The faecal pellets of these bat species were collected in the field and later analysed under a dissecting microscope. The three species studied are known to be very similar as far as their ecology, echolocation and preferred habitats are concerned, but they diverge significantly in their body sizes. In this study, all three species fed predominantly on moths [59–80 percentage frequency (%f); 87–95 percentage volume (%vol)], but their diet compositions differed in the size of individuals consumed. The smallest bat species (R. hipposideros) fed only on the smallest moths (%f = 59; %vol = 87), the medium-sized species (R. euryale) mainly on medium-sized moths (%f = 60; %vol = 74) and the largest one (R. ferrumequinum) especially on the largest moths (%f = 54; %vol = 89). Despite similar preferred habitat and the main prey category, the rates of trophic niche overlap were surprisingly low. The trophic niche percentage overlap was 7–31% (computed from %f data) and 1–20% (computed from %vol data), respectively and suggests an extraordinary importance of mere divergences of bats in their body sizes for trophic niche partitioning and stable species coexistence. 相似文献
312.
Stefan Heckmann Jiri Macas Katrin Kumke Jörg Fuchs Veit Schubert Lu Ma Petr Novák Pavel Neumann Stefan Taudien Matthias Platzer Andreas Houben 《The Plant journal : for cell and molecular biology》2013,73(4):555-565
In higher plants, the large‐scale structure of monocentric chromosomes consists of distinguishable eu‐ and heterochromatic regions, the proportions and organization of which depend on a species' genome size. To determine whether the same interplay is maintained for holocentric chromosomes, we investigated the distribution of repetitive sequences and epigenetic marks in the woodrush Luzula elegans (3.81 Gbp/1C). Sixty‐one per cent of the L. elegans genome is characterized by highly repetitive DNA, with over 30 distinct sequence families encoding an exceptionally high diversity of satellite repeats. Over 33% of the genome is composed of the Angela clade of Ty1/copia LTR retrotransposons, which are uniformly dispersed along the chromosomes, while the satellite repeats occur as bands whose distribution appears to be biased towards the chromosome termini. No satellite showed an almost chromosome‐wide distribution pattern as expected for a holocentric chromosome and no typical centromere‐associated LTR retrotransposons were found either. No distinguishable large‐scale patterns of eu‐ and heterochromatin‐typical epigenetic marks or early/late DNA replicating domains were found along mitotic chromosomes, although super‐high‐resolution light microscopy revealed distinguishable interspersed units of various chromatin types. Our data suggest a correlation between the centromere and overall genome organization in species with holocentric chromosomes. 相似文献
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315.
Nadine Mathieu Nina Kaczmarek Peter Rüthemann Andreas Luch Hanspeter Naegeli 《Current biology : CB》2013,23(3):204-212
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316.
J. Randall Flanagan Gerben Rotman Andreas F. Reichelt Roland S. Johansson 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2013,368(1628)
When watching an actor manipulate objects, observers, like the actor, naturally direct their gaze to each object as the hand approaches and typically maintain gaze on the object until the hand departs. Here, we probed the function of observers'' eye movements, focusing on two possibilities: (i) that observers'' gaze behaviour arises from processes involved in the prediction of the target object of the actor''s reaching movement and (ii) that this gaze behaviour supports the evaluation of mechanical events that arise from interactions between the actor''s hand and objects. Observers watched an actor reach for and lift one of two presented objects. The observers'' task was either to predict the target object or judge its weight. Proactive gaze behaviour, similar to that seen in self-guided action–observation, was seen in the weight judgement task, which requires evaluating mechanical events associated with lifting, but not in the target prediction task. We submit that an important function of gaze behaviour in self-guided action observation is the evaluation of mechanical events associated with interactions between the hand and object. By comparing predicted and actual mechanical events, observers, like actors, can gain knowledge about the world, including information about objects they may subsequently act upon. 相似文献
317.
Katarina Stingl Karl Ulrich Bartz-Schmidt Dorothea Besch Angelika Braun Anna Bruckmann Florian Gekeler Udo Greppmaier Stephanie Hipp Gernot H?rtd?rfer Christoph Kernstock Assen Koitschev Akos Kusnyerik Helmut Sachs Andreas Schatz Krunoslav T. Stingl Tobias Peters Barbara Wilhelm Eberhart Zrenner 《Proceedings. Biological sciences / The Royal Society》2013,280(1757)
This study aims at substituting the essential functions of photoreceptors in patients who are blind owing to untreatable forms of hereditary retinal degenerations. A microelectronic neuroprosthetic device, powered via transdermal inductive transmission, carrying 1500 independent microphotodiode-amplifier-electrode elements on a 9 mm2 chip, was subretinally implanted in nine blind patients. Light perception (8/9), light localization (7/9), motion detection (5/9, angular speed up to 35 deg s−1), grating acuity measurement (6/9, up to 3.3 cycles per degree) and visual acuity measurement with Landolt C-rings (2/9) up to Snellen visual acuity of 20/546 (corresponding to decimal 0.037 or corresponding to 1.43 logMAR (minimum angle of resolution)) were restored via the subretinal implant. Additionally, the identification, localization and discrimination of objects improved significantly (n = 8; p < 0.05 for each subtest) in repeated tests over a nine-month period. Three subjects were able to read letters spontaneously and one subject was able to read letters after training in an alternative-force choice test. Five subjects reported implant-mediated visual perceptions in daily life within a field of 15° of visual angle. Control tests were performed each time with the implant''s power source switched off. These data show that subretinal implants can restore visual functions that are useful for daily life. 相似文献
318.
Philippe Mayaux Jean-Fran?ois Pekel Baudouin Desclée Fran?ois Donnay Andrea Lupi Frédéric Achard Marco Clerici Catherine Bodart Andreas Brink Robert Nasi Alan Belward 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2013,368(1625)
This paper presents a map of Africa''s rainforests for 2005. Derived from moderate resolution imaging spectroradiometer data at a spatial resolution of 250 m and with an overall accuracy of 84%, this map provides new levels of spatial and thematic detail. The map is accompanied by measurements of deforestation between 1990, 2000 and 2010 for West Africa, Central Africa and Madagascar derived from a systematic sample of Landsat images—imagery from equivalent platforms is used to fill gaps in the Landsat record. Net deforestation is estimated at 0.28% yr−1 for the period 1990–2000 and 0.14% yr−1 for the period 2000–2010. West Africa and Madagascar exhibit a much higher deforestation rate than the Congo Basin, for example, three times higher for West Africa and nine times higher for Madagascar. Analysis of variance over the Congo Basin is then used to show that expanding agriculture and increasing fuelwood demands are key drivers of deforestation in the region, whereas well-controlled timber exploitation programmes have little or no direct influence on forest-cover reduction at present. Rural and urban population concentrations and fluxes are also identified as strong underlying causes of deforestation in this study. 相似文献
319.
Ioannis Petrakis Vasiliki Mavroeidi Kostas Stylianou George Efthymiou Kostas Perakis Eleftheria Vardaki Spyridon Stratigis Kostas Giannakakis Kostas Kourouniotis George Amoiridis Andreas Plaitakis Maria Joao Saraiva Ken Ichi Yamamura Eugene Daphnis 《Transgenic research》2013,22(1):101-116
Transthyretin related amyloidosis is a nosological entity that leads to disability, diminished quality of life, all stages of chronic kidney disease and eventually death. Podocytes are polarized, highly differentiated epithelial cells important for proper nephron function. In the present study we investigated whether deposited TTRVal30Met (TTRV30M) molecules could be localized within podocytes in situ under the effect of different housing conditions (i.e. specific pathogen free [SPF] vs. non-SPF). Murine renal glomeruli from human TTRV30M (hTTRV30M) transgenic mice were examined via direct and indirect immunofluorescence techniques for the presence of hTTRV30M, murine serum amyloid P, activated caspase-3 and NPHS1. Association strength and amount of colocalization for NPHS1?ChTTRV30M, NPHS1-activated caspase-3, hTTRV30M-murine serum amyloid P were estimated. Localization of hTTRV30M in podocytes was demonstrated by immuno-electron microscopy. Renal hTTRV30M gene and NPHS1 gene expression levels were estimated. Non-SPF transgenic mice showed increased glomerular hTTRV30M deposition compared to their SPF counterparts. Furthermore increased podocytic localization of hTTRV30M was noticed in non-SPF mice. Glomerular caspase-3 activation was increased only in the non SPF housing conditions. Podocytic caspase-3 activation was increased in SPF and in non-SPF transgenic mice when compared to non transgenic controls. Environmental conditions influence glomerular deposition and podocytic localization of hTTRV30M. In this context increased caspase-3 activation occurred. 相似文献
320.