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61.
Collection of blood from amphibians, as in other classes of vertebrate animals, is essential to evaluate parameters of health, diagnose hemoparasitism, identify viral and bacterial pathogens, and measure antibodies. Various methods of blood collection have been described for amphibians. Most can be cumbersome (venipucture of femoral vein, ventral abdominal vein or lingual venus plexus) or result in pain or deleterious health consequences (cardiac puncture and toe-clipping). We describe an easy and practical technique to collect blood from frogs and toads that can be used in multiple species and is minimally invasive. The technique consists of puncturing either the facial or, less commonly, the musculo-cutaneous vein and collecting the blood with a capillary tube. These veins run dorsal and parallel to the maxillary bone and can be accessed by quick insertion and withdrawal of a needle through the skin between the upper jawline and the rostral or caudal side of the tympanum. The needle should be of 27 or 30 gauge for anurans weighing more or less than 25 g, respectively. Although the technique has been used by some amphibian researchers for years, it is little known by others and has never been fully described in a peer-reviewed publication.  相似文献   
62.
Avian migration, which involves billions of birds flying vast distances, is known to influence all aspects of avian life. Here we investigate how birds fit moult into an annual cycle determined by the need to migrate. Large variation exists in moulting patterns in relation to migration: for instance, moult can occur after breeding in the summer or after arrival in the wintering quarters. Here we use an optimal annual routine model to investigate why this variation exists. The modelled bird's decisions depend on the time of year, its energy reserves, breeding status, experience, flight feather quality and location. Our results suggest that the temporal and spatial variations in food are an important influence on a migratory bird's annual cycle. Summer moult occurs when food has a high peak on the breeding site in the summer, but it is less seasonal elsewhere. Winter moult occurs if there is a short period of high food availability in summer and a strong winter peak at different locations (i.e. the food is very seasonal but in opposite phase on these areas). This finding might explain why only long-distance migrants have a winter moult.  相似文献   
63.
We identified a sequence homologous to the Bcl-2 homology 3 (BH3) domain of Bcl-2 proteins in SOUL. Tissues expressed the protein to different extents. It was predominantly located in the cytoplasm, although a fraction of SOUL was associated with the mitochondria that increased upon oxidative stress. Recombinant SOUL protein facilitated mitochondrial permeability transition and collapse of mitochondrial membrane potential (MMP) and facilitated the release of proapoptotic mitochondrial intermembrane proteins (PMIP) at low calcium and phosphate concentrations in a cyclosporine A-dependent manner in vitro in isolated mitochondria. Suppression of endogenous SOUL by diced small interfering RNA in HeLa cells increased their viability in oxidative stress. Overexpression of SOUL in NIH3T3 cells promoted hydrogen peroxide-induced cell death and stimulated the release of PMIP but did not enhance caspase-3 activation. Despite the release of PMIP, SOUL facilitated predominantly necrotic cell death, as revealed by annexin V and propidium iodide staining. This necrotic death could be the result of SOUL-facilitated collapse of MMP demonstrated by JC-1 fluorescence. Deletion of the putative BH3 domain sequence prevented all of these effects of SOUL. Suppression of cyclophilin D prevented these effects too, indicating that SOUL facilitated mitochondrial permeability transition in vivo. Overexpression of Bcl-2 and Bcl-xL, which can counteract the mitochondria-permeabilizing effect of BH3 domain proteins, also prevented SOUL-facilitated collapse of MMP and cell death. These data indicate that SOUL can be a novel member of the BH3 domain-only proteins that cannot induce cell death alone but can facilitate both outer and inner mitochondrial membrane permeabilization and predominantly necrotic cell death in oxidative stress.  相似文献   
64.
In Slovakia, a diversity of entomopathogenic fungi (Ascomycota, Hypocreales) associated with outbreaks of Ips typographus was studied in 81 localities and as many as 113 in vitro cultures of five entomopathogenic species were isolated from infected individuals: Beauveria bassiana (87 isolates), B. pseudobassiana (14 isolates), B. caledonica (6 isolates), Lecanicillium lecanii (4 isolates) and Isaria farinosa (2 isolates). B. pseudobassiana is recorded in natural populations of I. typographus for the first time. Biological properties of selected Beauveria isolates, including colony growth, biomass production, conidia yield and pathogenicity to I. typographus adults, were studied in a series of laboratory bioassays and much intra- and interspecific variability was detected. B. bassiana isolates produced biomass or conidia at significantly higher rate than B. pseudobassiana and B. caledonica isolates. Two B. bassiana isolates were selected as the most virulent to bark beetle adults, demonstrating a mean LC50 ranging from 0.72 to 2.05?×?106 conidia ml?1, and were qualified as promising candidates for biocontrol of I. typographus. Their virulence was significantly higher than that of the mycoinsecticides Boverol®, which was used as a reference strain in the virulence bioassays.  相似文献   
65.
Recent work on animal personalities has demonstrated that individuals may show consistent behaviour across situations and contexts. These studies were often carried out in one location and/or during short time intervals. Many animals, however, migrate and spend their life in several geographically distinct locations, and they may either adopt behaviours specific to the local environment or keep consistent behaviours over ecologically distinct locations. Long-distance migratory species offer excellent opportunities to test whether the animals maintain their personalities over large geographical scale, although the practical difficulties associated with these studies have hampered such tests. Here, we demonstrate for the first time consistency in disturbance tolerance behaviour in a long-distance migratory bird, using the common crane Grus grus as an ecological model species. Cranes that hatched in undisturbed habitats in Finland choose undisturbed migratory stop-over sites in Hungary, 1300-2000 km away from their breeding ground. This is remarkable, because these sites are not only separated by large distances, they also differ ecologically: the breeding sites are wooded bogs and subarctic tundra, whereas the migratory stop-over sites are temperate zone alkaline grasslands. The significance of our study goes beyond evolutionary biology and behavioural ecology: local effects on behaviour may carry over large distances, and this hitherto hidden implication of habitat selection needs to be incorporated into conservation planning.  相似文献   
66.
In the current study, we investigated the nature and role of CD44 variant isoforms involved in endothelial cell (EC) injury and tumor cell cytotoxicity mediated by IL-2-activated killer (LAK) cells. Treatment of CD44 wild-type lymphocytes with IL-2 led to increased gene expression of CD44 v6 and v7 variant isoforms and to significant induction of vascular leak syndrome (VLS). CD44v6-v7 knockout (KO) and CD44v7 KO mice showed markedly reduced levels of IL-2-induced VLS. The decreased VLS in CD44v6-v7 KO and CD44v7 KO mice did not result from differential activation and expansion of CD8+ T cells, NK, and NK-T cells or from altered degree of perivascular lymphocytic infiltration in the lungs. LAK cells from CD44v7 KO mice showed a significant decrease in their ability to adhere to and mediate lysis of EC but not lysis of P815 tumor cells in vitro. CD44v7-mediated lysis of EC by LAK cells was dependent on the activity of phosphatidylinositol 3-kinase and tyrosine kinases. Interestingly, IL-2-activated LAK cells expressing CD44hi but not CD44lo were responsible for EC lysis. Furthermore, lysis of EC targets could be blocked by addition of soluble or enzymatic cleavage of CD44v6-v7-binding glycosaminoglycans. Finally, anti-CD44v7 mAbs caused a significant reduction in the adherence to and killing of EC and led to suppression of IL-2-induced VLS. Together, this study suggests that the expression of CD44v7 on LAK cells plays a specific role in EC injury and that it may be possible to reduce EC injury but not tumor cell killing by specifically targeting CD44v7.  相似文献   
67.
The 8th International Coccidiosis Conference, held on 9--13 July 2001 in Palm Cove, Australia, was a showcase of the latest studies on widely known coccidia, including Eimeria and Toxoplasma in addition to the emerging or re-emerging parasites such as Neospora, Cryptosporidium and Cyclospora. This meeting was staged in conjunction with the Annual Scientific Meeting of the Australian Society for Parasitology.  相似文献   
68.
From this review of the 6 aspects of opportunity for inconsistency to corrupt or skew the reliability of data, it becomes apparent why members of management must provide the standards of operation and use within the CMMS for their employees. The possibility of poor data integrity due to any one of these aspects may not be severe; however, the severity is compounded and inevitable when different aspects are combined. Responding to information collected through the CMMS can be effective only if the data are reliable. With SOPs, management has provided their personnel with the necessary tools to ensure department-wide consistency. Management cannot afford to allow any one [table: see text] individual to apply personal interpretations of the importance and requirements in their approach to using the CMMS. If this is permitted, the loss of integrity due to one individual's judgment grows rapidly when data are analyzed at the departmental level. Standard operating procedures go beyond creating a "how to" for the CMMS; they provide the critical elements for collecting responsible and reliable data.  相似文献   
69.

Background  

Non-invasive autofluorescent reporters have revolutionized lineage labeling in an array of different organisms. In recent years green fluorescent protein (GFP) from the bioluminescent jellyfish Aequoria Victoria has gained popularity in mouse transgenic and gene targeting regimes [1]. It offers several advantages over conventional gene-based reporters, such as lacZ and alkaline phosphatase, in that its visualization does not require a chromogenic substrate and can be realized in vivo. We have previously demonstrated the utility and developmental neutrality of enhanced green fluorescent protein (EGFP) in embryonic stem (ES) cells and mice [2].  相似文献   
70.
The spectroscopy of horseradish peroxidase with and without the substrate analogue benzohydroxamic acid (BHA) was monitored in different solvents as a function of the temperature in the interval from 10 to 300 K. Thermal broadening of the Q(0,0) optical absorption band arises mainly from interaction of the electronic pi --> pi transition with the heme vibrations. In contrast, the width of the IR absorption band of CO bound to heme is controlled by the coupling of the CO transition moment to the electric field of the protein matrix. The IR bandwidth of the substrate free enzyme in the glycerol/H2O solvent hardly changes in the glassy matrix and strongly increases upon heating above the glass transition. Heating of the same enzyme in the trehalose/H2O glass considerably broadens the band. The binding of the substrate strongly diminishes the temperature broadening of the CO band. This result is consistent with the view that the BHA strongly reduces the amplitude of vibrations of the heme pocket environment. Unusually strong thermal broadening of the CO band above the glass transition is interpreted to be caused by thermal population of a very flexible excited conformational substate. The thermal broadening of the same band in the trehalose glass is caused by an increase of the protein vibrational amplitude in each of the conformational substates, their population being independent of the temperature in the glassy matrix.  相似文献   
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