928 research outputs found

    Statt einer Buchbesprechung: Wie geht man mit Plagiaten um?

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    Die Problematik des im Verlag Brill erschienenen Buchs "Spiders: Biology, Ecology, Natural History and Behavior" von Fred Punzo (2007) wird besprochen; schon beim ersten DurchblĂ€ttern war dem Rezensenten aufgefallen, dass "hier wenig Originales, dafĂŒr viel aus anderen LehrbĂŒchern 'Abgekupfertes' zu finden war, noch dazu in miserabler QualitĂ€t.

    Fluid-structure interaction study of spider's hair flow-sensing system

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    In the present work we study the spider's hair flow-sensing system by using fluid-structure interaction (FSI) numerical simulations. We observe experimentally the morphology of Theraphosa stirmi's hairs and characterize their mechanical properties through nanotensile tests. We then use the obtained information as input for the computational model. We study the effect of a varying air velocity and a varying hair spacing on the mechanical stresses and displacements. Our results can be of interest for the design of novel bio-inspired systems and structures for smart sensors and robotics

    Die Saurier in Frick

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    MONITORING THE COOLING AIR EFFLUENT FROM THE BROOKHAVEN GRAPHITE RESEARCH REACTOR AT THE POINT OF RELEASE AND IN THE ENVIRONMENT

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    The facilities for monitoring the particulate activity, Ar/sup 41/, and I/sup 131/ in the air effluent and the BGRR are described. The performance of the facilities under emergency conditions is studied for the release incident of Sept. 10 to 13, 1962; it is seen that the I/sup 131/ release, but not the particulate activity release, provided warning. (D.L.C.

    Comparative analysis of tissue-specific transcriptomes in the funnel-web spider Macrothele calpeiana

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    The funnel-web spider Macrothele calpeiana is a charismatic Mygalomorph with a great interest in basic, applied and translational research. Nevertheless, current scarcity of genomic and transcriptomic data of this species clearly limits the research in this non-model organism. To overcome this limitation, we launched the first tissue-specific enriched RNA-seq analysis in this species using a subtractive hybridization approach, with two main objectives, to characterize the specific transcriptome of the putative chemosensory appendages (palps and first pair of legs), and to provide a new set of DNA markers for further phylogenetic studies. We have characterized the set of transcripts specifically expressed in putative chemosensory tissues of this species, much of them showing features shared by chemosensory system genes. Among specific candidates, we have identified some members of the iGluR and NPC2 families. Moreover, we have demonstrated the utility of these newly generated data as molecular markers by inferring the phylogenetic position M. calpeina in the phylogenetic tree of Mygalomorphs. Our results provide novel resources for researchers interested in spider molecular biology and systematics, which can help to expand our knowledge on the evolutionary processes underlying fundamental biological questions, as species invasion or biodiversity origin and maintenance

    Measures of cardiac function in Theraphosidae spiders using in vivo magnetic resonance imaging

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    We report the first in vivo cardiac magnetic resonance imaging (MRI) measurements of Theraphosidae spiders. MRI scanning is performed on six spiders under isoflurane‐induced anaesthesia. Retrospective self‐gating cine‐cardiac MRI (RG‐CINE‐MRI) is used to overcome the difficulties of prospective cardiac gating in this species. The resulting RG‐CINE‐MRI images are successfully analyzed to obtain functional cardiac parameters from live spiders at rest. Cardiac ejection fraction is found to increase with animal mass (Pearson correlation 0.849, P = 0.03) at a faster rate than myocardial tissue volume, whereas heart rate remains constant across animals. This suggests the spider heart undergoes additional biomechanical loading with age. The results of the present study demonstrate the potential for retrospective gating with respect to evaluating aspects of cardiac function in a wide range of previously inaccessible species

    Distortion of the Local Magnetic Field Appears to Neither Disrupt Nocturnal Navigation nor Cue Shelter Recognition in the Amblypygid \u3ci\u3eParaphrynus laevifrons\u3c/i\u3e

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    Many arthropods are known to be sensitive to the geomagnetic field and exploit the field to solve spatial problems. The polarity of the geomagnetic field is used, for instance, as an orientation cue by leafcutter ants as they travel on engineered trails in a rainforest and by Drosophila larvae as they move short distances in search of food. A ubiquitous orientation cue like the geomagnetic field may be especially useful in complex, cluttered environments like rainforests, where the reliability of celestial cues used to navigate in more open environments may be poor. The neotropical amblypygid Paraphrynus laevifrons is a nocturnal arachnid that wanders nightly in the vicinity of its shelter and occasionally travels 30 m or more in the rainforest understory before it returns to its shelter. Here, we conducted a field experiment to determine whether navigation by P. laevifrons is guided by the ambient magnetic field and a complementary laboratory experiment to assess whether a magnetic anomaly could be used to pinpoint the entrance of a shelter. In the field experiment, subjects were fitted with a radio transmitter and a small, powerful magnet or a similar-sized brass disk and displaced 10 m from their shelter. The return rate of magnet-fitted subjects was similar to that of brass-fitted subjects and to that of subjects in an earlier study fitted with only a radio transmitter. In the laboratory experiment, we trained P. laevifrons with a protocol under which the amblypygid Phrynus marginemaculatus rapidly learns—in 1–14 trials over two daily sessions—to associate an olfactory stimulus with access to a shelter. The conditioned stimulus here was a magnetic anomaly characterized by a high total field intensity and a 180° reversal of the polarity of the ambient magnetic field. The magnetic anomaly–shelter contingency was not learned in 50 trials conducted over 10 daily sessions. These results imply prima facie that P. laevifrons does not rely on a magnetic compass to locate or recognize a shelter and, perhaps, that the magnetic field cannot be detected, but alternative explanations are discussed

    Arachnidism, scorpionism and ophidism in Ouro Preto Municipality, Minas Gerais State, Brazil

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    Abstract: INTRODUCTION This retrospective study shows the profile of arachnidism, ophidism, and scorpionism in the Ouro Preto Municipality, Brazil, from January 2007 to December 2013. METHODS The data were gathered from forms of the Epidemiological Surveillance Sector of the town's Health's Municipal Secretary. RESULTS Of the 412 envenomations, 308 were caused by spiders, 78 by scorpions, and 26 by snakes. The highest number of incidents involved people aged 20-34 years. Females were more affected than males. There were no reports of death. CONCLUSIONS The results show that envenomations caused by spiders, scorpions and snakes have decreased in recent years
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