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31.
Franz Josef van der Staay Martin Joosse Henk van Dijk Teun Schuurman Jan van der Meulen 《BMC veterinary research》2011,7(1):16
Background
Anecdotal reports and a few scientific publications suggest that flyovers of helicopters at low altitude may elicit fear- or anxiety-related behavioral reactions in grazing feral and farm animals. We investigated the behavioral and physiological stress reactions of five individually housed dairy goats to different acoustic and visual stimuli from helicopters and to combinations of these stimuli under controlled environmental (indoor) conditions. The visual stimuli were helicopter animations projected on a large screen in front of the enclosures of the goats. Acoustic and visual stimuli of a tractor were also presented. On the final day of the study the goats were exposed to two flyovers (altitude 50 m and 75 m) of a Chinook helicopter while grazing in a pasture. Salivary cortisol, behavior, and heart rate of the goats were registered before, during and after stimulus presentations. 相似文献32.
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Liquid transport of minute amounts of biomaterials is of paramount importance in many biotechnological applications. One of the challenges is the transport of viscous liquids without heating. Electro hydro dynamic atomization or electrospray is a viable method for the controlled transport of nanoliter volume of viscous liquids as shown for PEG400. Experimental results and the design of a novel spraying configuration, which can be incorporated in an optical microscope, are reported. 相似文献
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The platypus is in its place: nuclear genes and indels confirm the sister group relation of monotremes and Therians 总被引:9,自引:0,他引:9
van Rheede T Bastiaans T Boone DN Hedges SB de Jong WW Madsen O 《Molecular biology and evolution》2006,23(3):587-597
Morphological data supports monotremes as the sister group of Theria (extant marsupials + eutherians), but phylogenetic analyses of 12 mitochondrial protein-coding genes have strongly supported the grouping of monotremes with marsupials: the Marsupionta hypothesis. Various nuclear genes tend to support Theria, but a comprehensive study of long concatenated sequences and broad taxon sampling is lacking. We therefore determined sequences from six nuclear genes and obtained additional sequences from the databases to create two large and independent nuclear data sets. One (data set I) emphasized taxon sampling and comprised five genes, with a concatenated length of 2,793 bp, from 21 species (two monotremes, six marsupials, nine placentals, and four outgroups). The other (data set II) emphasized gene sampling and comprised eight genes and three proteins, with a concatenated length of 10,773 bp or 3,669 amino acids, from five taxa (a monotreme, a marsupial, a rodent, human, and chicken). Both data sets were analyzed by parsimony, minimum evolution, maximum likelihood, and Bayesian methods using various models and data partitions. Data set I gave bootstrap support values for Theria between 55% and 100%, while support for Marsupionta was at most 12.3%. Taking base compositional bias into account generally increased the support for Theria. Data set II exclusively supported Theria, with the highest possible values and significantly rejected Marsupionta. Independent phylogenetic evidence in support of Theria was obtained from two single amino acid deletions and one insertion, while no supporting insertions and deletions were found for Marsupionta. On the basis of our data sets, the time of divergence between Monotremata and Theria was estimated at 231-217 MYA and between Marsupialia and Eutheria at 193-186 MYA. The morphological evidence for a basal position of Monotremata, well separated from Theria, is thus fully supported by the available molecular data from nuclear genes. 相似文献
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Phospholipid signalling in plant defence 总被引:11,自引:0,他引:11
Phospholipid-derived molecules are emerging as novel second messengers in plant defence signalling. Recent research has begun to reveal the signals produced by the enzymes phospholipase C, phospholipase D and phospholipase A2 and their putative downstream targets. These include the activation of a MAP kinase cascade and triggering of an oxidative burst by phosphatidic acid; the regulation of ion channels and proton pumps by lysophospholipids and free fatty acids; and the conversion of free fatty acids into bioactive octadecanoids such as jasmonic acid. 相似文献
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Volkmar Passoth Ann-Christin Andersson Matilda Olstorpe Bart Theelen Teun Boekhout Johan Schnürer 《Antonie van Leeuwenhoek》2009,96(4):635-643
Two yeast strains isolated in 2007 from fermented pig feed were studied, including the analysis of sequences of the D1/D2
and ITS-regions of the rDNA-repeats, their morphology and nutritional physiology. Sequence comparison of the D1/D2 and ITS
regions demonstrated that the strains do not belong to any known species. Therefore, a new species, Cryptococcus cerealis with the type strain CBS 10505, is proposed. The species belongs to Filobasidiales (Agaricomycetes, Basidiomycota), and has
Cryptococcus saitoi as the closest related species. The new species is psychrophilic, showing significant growth at 4 and 10°C. 相似文献
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