182,549 research outputs found

    The electron density distribution in CN−, LiCN and LiNC. The use of minimal and extended basis set SCF calculations

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    Electron density maps are reported for the CN−ion and the LiCN and LiNC molecules, calculated from molecular wave-functions near the Hartree-Fock limit. The electron density distribution derived from CNDO/ 2 wavefunctions does not resemble the ab initio results. The ultimate ability of a minimal basis set to represent the electron density near the Hartree-Fock limit, has been tested. The requirement of N-representability of the trial electron density has been satisfied. It is found that the molecular valence density cannot be reproduced to a satisfactory extent by a minimal set of Slater orbitals, even when the exponents of the basis orbitals are optimized

    Response to Frequency Shifted Artificial Echoes in the Bat Rhinolophus ferrumequinum

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    In 5 roosting bats the resting frequency, that is the mean frequency of the cf-portion of consecutive sounds, is kept constant with a standard deviation which varies between 30 120 Hz in different bats and at different days. In 15 bats the emitted sounds were electronically shifted in frequency and played back as artificial echoes. Upward frequency shifts were responded by a decrease of the emission frequency. This frequency compensation occurred at frequency shifts of up to 4400 Hz in all bats and up to 6000 ttz in a few bats. The frequency decrease in different bats over the whole compensation range was 50-300 tIz smaller than the frequency shifts in the echoes. The echoes, therefore, returned at a frequency, called the reference frequency, which was by this compensation offset higher than the resting frequency. The standard deviations of the emission frequency in compensating bats were only slightly larger than in roosting bats and the same in the whole compensation range. All bats started to compensate frequency shifts when they were slightly larger than the compensation offset. Downward frequency shifts were not responded by a change of the emission frequency, but the accuracy with which the emission frequency was kept decreased somewhat. From these results it is concluded that the Doppler shift compensation system of the Horseshoe bats compares the echo frequency with the reference frequency and compensates deviations of upward frequency shifts

    Novel hemotropic mycoplasmas are widespread and genetically diverse in vampire bats

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    Bats (Order: Chiroptera) have been widely studied as reservoir hosts for viruses of concern for human and animal health. However, whether bats are equally competent hosts of non-viral pathogens such as bacteria remains an important open question. Here, we surveyed blood and saliva samples of vampire bats from Peru and Belize for hemotropic Mycoplasma spp. (hemoplasmas), bacteria that can cause inapparent infection or anemia in hosts. 16S rRNA gene amplification of blood showed 67% (150/223) of common vampire bats (Desmodus rotundus) were infected by hemoplasmas. Sequencing of the 16S rRNA gene amplicons revealed three novel genotypes that were phylogenetically related but not identical to hemoplasmas described from other (non-vampire) bat species, rodents, humans, and non-human primates. Hemoplasma prevalence in vampire bats was highest in non-reproductive and young individuals, did not differ by country, and was relatively stable over time (i.e., endemic). Metagenomics from pooled D. rotundus saliva from Peru detected non-hemotropic Mycoplasma species and hemoplasma genotypes phylogenetically similar to those identified in blood, providing indirect evidence for potential direct transmission of hemoplasmas through biting or social contacts. This study demonstrates vampire bats host several novel hemoplasmas and sheds light on risk factors for infection and basic transmission routes. Given the high frequency of direct contacts that arise when vampire bats feed on humans, domestic animals, and wildlife, the potential of these bacteria to be transmitted between species should be investigated in future work

    Hemotropic mycoplasmas in little brown bats (Myotis lucifugus).

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    BackgroundHemotropic mycoplasmas are epicellular erythrocytic bacteria that can cause infectious anemia in some mammalian species. Worldwide, hemotropic mycoplasmas are emerging or re-emerging zoonotic pathogens potentially causing serious and significant health problems in wildlife. The objective of this study was to determine the molecular prevalence of hemotropic Mycoplasma species in little brown bats (Myotis lucifugus) with and without Pseudogymnoascus (Geomyces) destrucans, the causative agent of white nose syndrome (WNS) that causes significant mortality events in bats.MethodsIn order to establish the prevalence of hemotropic Mycoplasma species in a population of 68 little brown bats (Myotis lucifugus) with (n = 53) and without (n = 15) white-nose syndrome (WNS), PCR was performed targeting the 16S rRNA gene.ResultsThe overall prevalence of hemotropic Mycoplasmas in bats was 47%, with similar (p = 0.5725) prevalence between bats with WNS (49%) and without WNS (40%). 16S rDNA sequence analysis (~1,200 bp) supports the presence of a novel hemotropic Mycoplasma species with 91.75% sequence homology with Mycoplasma haemomuris. No differences were found in gene sequences generated from WNS and non-WNS animals.ConclusionsGene sequences generated from WNS and non-WNS animals suggest that little brown bats could serve as a natural reservoir for this potentially novel Mycoplasma species. Currently, there is minimal information about the prevalence, host-specificity, or the route of transmission of hemotropic Mycoplasma spp. among bats. Finally, the potential role of hemotropic Mycoplasma spp. as co-factors in the development of disease manifestations in bats, including WNS in Myotis lucifugus, remains to be elucidated

    “What is it like to be a bat?”—a pathway to the answer from the integrated information theory

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    What does it feel like to be a bat? Is conscious experience of echolocation closer to that of vision or audition? Or do bats process echolocation nonconsciously, such that they do not feel anything about echolocation? This famous question of bats' experience, posed by a philosopher Thomas Nagel in 1974, clarifies the difficult nature of the mind–body problem. Why a particular sense, such as vision, has to feel like vision, but not like audition, is totally puzzling. This is especially so given that any conscious experience is supported by neuronal activity. Activity of a single neuron appears fairly uniform across modalities and even similar to those for non-conscious processing. Without any explanation on why a particular sense has to feel the way it does, researchers cannot approach the question of the bats' experience. Is there any theory that gives us a hope for such explanation? Currently, probably none, except for one. Integrated information theory has potential to offer a plausible explanation. IIT essentially claims that any system that is composed of causally interacting mechanisms can have conscious experience. And precisely how the system feels is determined by the way the mechanisms influence each other in a holistic way. In this article, I will give a brief explanation of the essence of IIT. Further, I will briefly provide a potential scientific pathway to approach bats' conscious experience and its philosophical implications. If IIT, or its improved or related versions, is validated enough, the theory will gain credibility. When it matures enough, predictions from the theory, including nature of bats' experience, will have to be accepted. I argue that a seemingly impossible question about bats' consciousness will drive empirical and theoretical consciousness research to make big breakthroughs, in a similar way as an impossible question about the age of the universe has driven modern cosmology

    Fish and amphibians as bat predators

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    Although bats (Chiroptera) belong to the most diverse mammalian orders, study of diversity of their natural predators has been seriously neglected for a long time. While some recent reviews contain comprehensive overviews of our recent knowledge on these phenomena for some animal groups, such work is still lacking for anamniotes - fishes and amphibians. Here, I am summarising bat predation incidences by anamniotes that were published in scientific journals and public web domains. I found out that at least 14 species of fishes and 14 species of frogs were observed as feeding on bats. Moreover, 7 and 16 species of bats were recorded as victims of hunting activity of fishes and frogs, respectively. Majority of localised incidences came from the New World; frog (between latitude 49°N to 28°S) attacks were distributed mainly in tropical or subtropical areas < 30° from equator (70% of all records), fish (44°N to 20°S) incidences reach same proportion in colder areas (> 30° from equator) and warmer areas. In some cases, these predators can regularly feed on bats, especially when hunting near roosting places of bats; however, with respect to number of recorded cases (21 for fishes and 37 for amphibians), bat predation by anamniotes seems to be very rare and opportunistic with only very limited influence on bat populations or their behaviour

    Understanding movement and habitat selection of the lesser short-tailed bat to infer potential encounters with anticoagulant bait : a thesis presented in partial fulfilment of the requirements for the Degree of Master of Science in Zoology at Massey University, Manawatū, New Zealand

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    The lesser short-tailed bat (Mystacina tuberculata) and the long-tailed bat (Chalinolobus tuberculatus) are New Zealand’s only extant endemic land-dwelling mammals. Both species are listed as nationally endangered by the IUCN, with numbers declining due to widespread habitat destruction and other human interferences. Short-tailed bats have been an unintentional victim of toxins used for pest control in New Zealand, being particularly susceptible to poisoning due to their diverse diet and ground-feeding habits. To manage toxin use to minimize bat exposure it is necessary to understand their movements and area usage behaviours. Movements and habitat use of the short-tailed bat were studied on the area of farmland between Pikiariki and Waipapa Ecological Area, Pureora Forest Park, New Zealand. Bats using the area between the two large forests were studied using acoustic monitoring and radio telemetry techniques to determine which routes they use, how they utilise the farmland and forest fragments along the way, and how they interact with obstacles such as open farmland and roads. Evidence of foraging was more often observed near forest fragments than open areas. While levels of habitat preference varied among individuals, forest was consistently selected over open areas throughout their commutes over farmland. 50% of the radio tracked bats were commuting directly between Pikiariki and Waipapa, while a further 25% were deemed to forage or rest throughout the trip. These results confirm that short-tailed bats utilise marginal habitats on private land, suggesting a need for the implementation of safe pest control in areas near known colonies on both public and conservation land. Stronger toxins are often used on private land so the risks to short-tailed bats could be higher. The results also provide information on how short-tailed bats make use of a fragmented environment, and whether we need to create forest bridges across open farmland to assist the nightly commute of bats

    Predictors and immunological correlates of sublethal mercury exposure in vampire bats

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    Mercury (Hg) is a pervasive heavy metal that often enters the environment from anthropogenic sources such as gold mining and agriculture. Chronic exposure to Hg can impair immune function, reducing the ability of animals to resist or recover from infections. How Hg influences immunity and susceptibility remains unknown for bats, which appear immunologically distinct from other mammals and are reservoir hosts of many pathogens of importance to human and animal health. We here quantify total Hg (THg) in hair collected from common vampire bats (Desmodus rotundus), which feed on blood and are the main reservoir hosts of rabies virus in Latin America. We examine how diet, sampling site and year, and bat demography influence THg and test the consequences of this variation for eight immune measures. In two populations from Belize, THg concentrations in bats were best explained by an interaction between long-term diet inferred from stable isotopes and year. Bats that foraged more consistently on domestic animals exhibited higher THg. However, relationships between diet and THg were evident only in 2015 but not in 2014, which could reflect recent environmental perturbations associated with agriculture. THg concentrations were low relative to values previously observed in other bat species but still correlated with bat immunity. Bats with higher THg had more neutrophils, weaker bacterial killing ability and impaired innate immunity. These patterns suggest that temporal variation in Hg exposure may impair bat innate immunity and increase susceptibility to pathogens such as bacteria. Unexpected associations between low-level Hg exposure and immune function underscore the need to better understand the environmental sources of Hg exposure in bats and the consequences for bat immunity and susceptibility
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