Quantitative extraction of macro-invertebrates from temperate and tropical leaf litter and soil: efficiency and time-dependent taxonomic biases of the Winkler extraction   总被引：2，自引：0，他引：2  

Frank-Thorsten Krell  Arthur Y.C. Chung  Emma DeBoise  Paul Eggleton  Alessandro Giusti  Kelly Inward  Sylvia Krell-Westerwalbesloh 《Pedobiologia》2005,49(2):175-186

Winkler extractors, a simple device presumed to extract macro-invertebrates efficiently from soil and litter samples, is being used increasingly in ecological surveys and functional studies of soil macro-invertebrate communities. In this study the extraction efficiency and taxonomic bias of the Winkler extraction are evaluated for extraction periods of 3 h up to 7 weeks, calibrated by hand-sorting after 7 weeks. The method extracts most macro-invertebrates completely or to a proportion of over 90% except Isopoda, Diplopoda and Mollusca. However, for an exhaustive result, a long extraction period of several weeks is necessary. For the most speciose group (adult beetles) and for the commonly most abundant group (ants), a short extraction of 3 days was sufficient to get 70% of the individuals and nearly all species. Three days was also sufficient to recover the rank abundance order of beetle families, while for ‘higher taxa’ and for Chilopoda species, 4 and 3 weeks were necessary, respectively. Optimum extraction times for the abundant macro-invertebrate groups and possible adjustment factors for the soil macro-invertebrates of temperate woodlands are proposed to compensate the taxonomic bias caused by short extraction periods. However, for recording an accurate snapshot of the soil and litter fauna at a particular time, shorter extraction periods are advisable because of the short life cycle of many soil invertebrates causing emergence of later stages or a second generation during longer extraction periods. The problem of contamination of samples is also discussed.  相似文献   

A molecular phylogeny for bats illuminates biogeography and the fossil record     

Teeling EC  Springer MS  Madsen O  Bates P  O'brien SJ  Murphy WJ 《Science (New York, N.Y.)》2005,307(5709):580-584

Bats make up more than 20% of extant mammals, yet their evolutionary history is largely unknown because of a limited fossil record and conflicting or incomplete phylogenies. Here, we present a highly resolved molecular phylogeny for all extant bat families. Our results support the hypothesis that megabats are nested among four major microbat lineages, which originated in the early Eocene [52 to 50 million years ago (Mya)], coincident with a significant global rise in temperature, increase in plant diversity and abundance, and the zenith of Tertiary insect diversity. Our data suggest that bats originated in Laurasia, possibly in North America, and that three of the major microbat lineages are Laurasian in origin, whereas the fourth is Gondwanan. Combining principles of ghost lineage analysis with molecular divergence dates, we estimate that the bat fossil record underestimates (unrepresented basal branch length, UBBL) first occurrences by, on average, 73% and that the sum of missing fossil history is 61%.  相似文献   

The unusual nature of recent snowpack declines in the North American cordillera     

Pederson GT  Gray ST  Woodhouse CA  Betancourt JL  Fagre DB  Littell JS  Watson E  Luckman BH  Graumlich LJ 《Science (New York, N.Y.)》2011,333(6040):332-335

In western North America, snowpack has declined in recent decades, and further losses are projected through the 21st century. Here, we evaluate the uniqueness of recent declines using snowpack reconstructions from 66 tree-ring chronologies in key runoff-generating areas of the Colorado, Columbia, and Missouri River drainages. Over the past millennium, late 20th century snowpack reductions are almost unprecedented in magnitude across the northern Rocky Mountains and in their north-south synchrony across the cordillera. Both the snowpack declines and their synchrony result from unparalleled springtime warming that is due to positive reinforcement of the anthropogenic warming by decadal variability. The increasing role of warming on large-scale snowpack variability and trends foreshadows fundamental impacts on streamflow and water supplies across the western United States.  相似文献   

Hydroxylysyl pyridinoline cross-link concentration affects the textural properties of fresh and smoked Atlantic salmon (Salmo salar L.) flesh     

Li X  Bickerdike R  Lindsay E  Campbell P  Nickell D  Dingwall A  Johnston IA 《Journal of agricultural and food chemistry》2005,53(17):6844-6850

A simple HPLC method is presented to quantify the low concentration of hydroxylysyl pyridinoline (PYD) cross-links in Atlantic salmon (Salmo salar L.) muscle. The method involved the extraction of tissue with NaOH prior to hydrolysis, which greatly reduced the amount of protein to be hydrolyzed and made downstream operations easier and more reproducible. The concentration of PYD was 426 pmol g(-)(1) dry mass muscle in post-rigor muscle stored at 0 degrees C and sampled 3 d after death. Hydroxproline (HYP) concentration was determined following NaOH extraction as a measure of collagen content. In post-rigor samples, the alkaline-insoluble HYP fraction comprised 18.3% of the total HYP. Scanning electron microscopy revealed shrinkage of muscle fibers and a retraction of the connective tissue matrix in smoked salmon. PYD concentration was relatively resistant to processing to the smoked product, decreasing by around 11.7%, as compared to a 22.2% decrease in HYP. There was a positive correlation between PYD concentration and the firmness of post-rigor muscle samples as measured by an instrumental texture analyzer, explaining 25% of the total variation. A weaker but still significant correlation was found between PYD concentration and firmness in the smoked product. There was no relationship between fillet firmness and total collagen concentration, although the correlation with HYP in the alkaline-insoluble fraction was significant at the 6% level (P = 0.057). Our results indicate that only 1-3% of collagen molecules are linked by nonreducible mature cross-links in harvest size farmed Atlantic salmon and that PYD concentration is an important raw material characteristic for flesh quality.  相似文献   

WCVM GLOBAL VETS          下载免费PDF全文

Mairead Drain  Emma Agg  Leanne Boyd  Suzanne Lynde  Rebecca Korven  Karen Kemp  Patrick Garcia  Sarah Flint    Shannon Burns 《The Canadian veterinary journal. La revue veterinaire canadienne》2003,44(2):121-122

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Withdrawal period for Ovitelmin S&C     

Jones E 《The Veterinary record》2005,156(1):28

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Calcospherite-like bodies and caseous necrosis in tracheal mucus from a dog with tuberculosis     

Bauer NB  O'Neill E  Sheahan BJ  Cassidy J  McAllister H 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2004,33(3):168-172

A 3-year-old Wirehaired Fox Terrier was presented to the University Veterinary Hospital, University College Dublin, for evaluation of chronic cough of 8-months duration. Bronchoscopy showed a severely dilated collapsed left principal bronchus filled with highly viscous white mucus. Cytologically, globular lipid-like material and round concentrically laminated crystalline structures were evident within the proteinaceous mucus. These findings resembled the calcospherites and granular caseous debris often observed in human tuberculous patients. A Ziehl-Neelsen-stained cytocentrifuged preparation of material obtained by bronchoalveolar lavage revealed a few acid-fast rods within macrophages, suggestive of tuberculosis. At necropsy, granulomas with caseous necrosis were present in the lung parenchyma, bronchial and mediastinal lymph nodes, liver, pancreas, and mesentery. Granulomas were adherent to both kidney capsules and to the diaphragm. Histologically, there was evidence of mild calcification within caseous granulomas, which was confirmed by von Kossa's stain. Using Ziehl-Neelsen stain, acid-fast rods were identified within granulomas; bacterial culture was positive for Mycobacterium bovis. The cytologic findings in this case have not been reported previously in dogs and demonstrate a possible correlation between tuberculosis and calcospherite-like bodies with caseous, globular material in bronchial mucus, similar to that described in human patients.  相似文献   

Storage of spatial information by the maintenance mechanism of LTP   总被引：2，自引：0，他引：2  

Pastalkova E  Serrano P  Pinkhasova D  Wallace E  Fenton AA  Sacktor TC 《Science (New York, N.Y.)》2006,313(5790):1141-1144

Analogous to learning and memory storage, long-term potentiation (LTP) is divided into induction and maintenance phases. Testing the hypothesis that the mechanism of LTP maintenance stores information requires reversing this mechanism in vivo and finding out whether long-term stored information is lost. This was not previously possible. Recently however, persistent phosphorylation by the atypical protein kinase C isoform, protein kinase Mzeta (PKMz), has been found to maintain late LTP in hippocampal slices. Here we show that a cell-permeable PKMz inhibitor, injected in the rat hippocampus, both reverses LTP maintenance in vivo and produces persistent loss of 1-day-old spatial information. Thus, the mechanism maintaining LTP sustains spatial memory.  相似文献   

Surgical Treatment of an Intracranial Epidermoid Cyst in a Dog     

Steven De Decker DVM  PhD  Emma Davies DVM  Diplomate ECVN  Livia Benigni DVM  Diplomate ECVDI  Helen Wilson BVSc  Ludovic Pelligand DVM  PhD  Diplomate ECVAA  Emma L. Rayner BSc  BVetMed  FRCPath  MRCVS  Nadia Shihab MA  VetMB  Diplomate ECVN  Holger A. Volk DVM  PhD  Diplomate ECVN 《Veterinary surgery : VS》2012,41(6):766-771

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Increase in chemokines CXCL10 and CCL2 in blood from pigs infected with high compared to low virulence African swine fever virus isolates     

Emma Fishbourne  Evelyne Hutet  Charles Abrams  Roland Cariolet  Marie-Frédérique Le Potier  Haru-H Takamatsu  Linda K Dixon 《Veterinary research》2013,44(1):87

Modulation of the expression of chemokines and chemokine receptors in whole blood was compared following infection of pigs with high and low virulence isolates of African swine fever virus. Levels of mRNAs for CCL2, CCL3L1, CCL4, CXCL10, CCR1 and CCR5 were significantly increased in at least one time point following infection in two experiments and CCL5, CCR9 and CXCR4 mRNA were significantly increased in one of the experiments. The results showed that greatest fold increases in mRNAs for CXCL10 and CCL2 were observed following infection of pigs. CXCL10 mRNA was increased by up to 15 fold in infected compared to uninfected pigs. CXCL10 protein was also detected in serum from pigs infected with the high virulence Benin 97/1 isolate. Levels of CCL2 mRNA were increased in pigs infected with high virulence Benin 97/1 isolate compared to low virulence OURT88/3 isolate and this correlated with an increase of greater than 30 fold in levels of CCL2 protein detected in serum from pigs infected with this isolate. An increase in overall chemotaxis active compounds in defibrinated plasma samples from Benin 97/1 infected pigs was observed at 3 days post-infection (dpi) and a decrease by 7 dpi as measured by chemotaxis assay using normal pig leucocytes in vitro. Increased levels of CXCL10 may either contribute to the activation of lymphocyte priming toward the Th1 phenotype or induction of T lymphocyte apoptosis. Increased levels of CCL2, a chemoattractant for macrophages, may result in increased recruitment of monocytes from bone marrow thus increasing the pool of cells susceptible to infection.  相似文献