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21.
Management of crested caracaras (Caracara cheriway), focuses on nests identified during surveys. If no nests are found, management can be suspended. Thus, false negatives can have substantial consequences. We surveyed 49 breeding territories to assess factors with the potential to cause false negatives in detecting nests of crested caracaras and in observing adult birds. The probability that a nest would be detected on any given visit increased by about 0.5% for each hour of observer experience up to about 70 hours (our maximum). Experience did not affect the probability of observing an adult. The probability of detecting a caracara nest or observing an adult caracara decreased by 2.0–3.5% each hour after sunrise that a visit began. If visibility during any portion of a visit was obscured by fog or rain, the probability of detecting a nest decreased by as much as 60%, and the probability of observing an adult caracara decreased by about 50%. We provide a tool managers can use to calculate the likelihood of successful surveys. We recommend that managers disregard negative results from surveys conducted under conditions that are unlikely to yield positive results, and repeat those surveys under better conditions. © 2011 The Wildlife Society.  相似文献   
22.
The structure–activity relationships for a series of heteroaryl urea inhibitors of fatty acid amide hydrolase (FAAH) are described. Members of this class of inhibitors have been shown to inactivate FAAH by covalent modification of an active site serine with subsequent release of an aromatic amine from the urea electrophile. Systematic Ames II testing guided the optimization of urea substituents by defining the structure–mutagenicity relationships for the released aromatic amine metabolites. Potent FAAH inhibitors were identified having heteroaryl amine leaving groups that were non-mutagenic in the Ames II assay.  相似文献   
23.
During the past two years a pilot project was conducted in which 19 inactive physicians were retrained in preparation for resumption of active practice. The initial program consisted of a flexible training program of six months to one year patterned after conventional internship-residency concepts. During the second year the program was modified by providing an initial condensed indoctrination period of two months'' duration especially designed for this purpose, followed by a preceptorship type of training.The project was considered successful in permitting trainees to enter some form of active medical work, or to enroll in formal specialty training. The observations made by the faculty of the program and its accomplishments are discussed in the light of the effort expended and the cost of the project.  相似文献   
24.
An orally available iron chelator is desirable for the treatment of secondary iron overload. Pyridoxal isonicotinoyl hydrazone (PIH) and its analogs effectively mobilize iron in vivo and in vitro, and are therefore promising candidates for this purpose. PIH analogs undergo significant amino acid-catalyzed hydrolysis in cell culture medium and in serum, achieving equilibrium with their corresponding aldehydes and hydrazides with half-times of 1-8 h. The extent of hydrolysis in RPMI is significant, even in experiments of a few hours' duration, although the half-life of PIH in phosphate-buffered saline (PBS) is approximately 24 h. Therefore, the biological effects (e.g., 59Fe mobilization, toxicity) of these iron chelators have been underestimated in previous studies. Measurement of the affinity of PIH analogs for Fe(3+) under conditions in which hydrolysis is minimal resulted in conditional affinity constants of 10(26) to 10(27) M, which are much lower than predicted by the overall formation constants determined under conditions that likely allowed extensive hydrolysis. These data indicate the importance of hydrolysis of PIH analogs in the interpretation of previous studies, and the importance of designing clinically useful analogs whose efficacies are not limited by hydrolysis.  相似文献   
25.

Background  

To compare the characteristics and prognostic features of ischemic stroke in patients with diabetes and without diabetes, and to determine the independent predictors of in-hospital mortality in people with diabetes and ischemic stroke.  相似文献   
26.
Yeast lacking copper-zinc superoxide dismutase (sod1?) have a number of oxygen-dependent defects, including auxotrophies for lysine and methionine and sensitivity to oxygen. Here we report additional defects in metabolic regulation. Under standard growth conditions with glucose as the carbon source, yeast undergo glucose repression in which mitochondrial respiration is deemphasized, energy is mainly derived from glycolysis, and ethanol is produced. When glucose is depleted, the diauxic shift is activated, in which mitochondrial respiration is reemphasized and stress resistance increases. We find that both of these programs are adversely affected by the lack of Sod1p. Key events in the diauxic shift do not occur and sod1? cells do not utilize ethanol and stop growing. The ability to shift to growth on ethanol is gradually lost as time in culture increases. In early stages of culture, sod1? cells consume more oxygen and have more mitochondrial mass than wild-type cells, indicating that glucose repression is not fully activated. These changes are at least partially dependent on the activity of the Hap2,3,4,5 complex, as indicated by CYC1-lacZ reporter assays. These changes may indicate a role for superoxide in metabolic signaling and regulation and/or a role for glucose derepression in defense against oxidative stress.  相似文献   
27.
28.
Exogenous purified rabbit skeletal-muscle glycogen synthase was used as a substrate for adipose-tissue phosphoprotein phosphatase from fed and starved rats in order to (1) compare the relationship between phosphate released from, and the kinetic changes imparted to, the substrate and (2) ascertain if decreases in adipose-tissue phosphatase activity account for the apparent decreased activation of endogenous glycogen synthase from starved as compared with fed rats. Muscle glycogen synthase was phosphorylated with [gamma-(32)P]ATP and cyclic AMP-dependent protein kinase alone, or in combination with a cyclic AMP-independent protein kinase, to 1.7 or 3mol of phosphate per subunit. Adipose-tissue phosphatase activity determined with phosphorylated skeletal-muscle glycogen synthase as substrate was decreased by 35-60% as a consequence of starvation. This decrease in phosphatase activity had little effect on the capacity of adipose-tissue extracts to activate exogenous glycogen synthase (i.e. to increase the glucose 6-phosphate-independent enzyme activity), although there were marked differences in the activation profiles for the two exogenous substrates. Glycogen synthase phosphorylated to 1.7mol of phosphate per subunit was activated rapidly by adipose-tissue extracts from either fed or starved rats, and activation paralleled enzyme dephosphorylation. Glycogen synthase phosphorylated to 3mol of phosphate per subunit was activated more slowly and after a lag period, since release of the first mol of phosphate did not increase the glucose 6-phosphate-independent activity of the enzyme. These patterns of enzyme activation were similar to those observed for the endogenous adipose-tissue glycogen synthase(s): the glucose 6-phosphate-independent activity of the endogenous enzyme from fed rats increased rapidly during incubation, whereas that of starved rats, like that of the more highly phosphorylated muscle enzyme, increased only very slowly after a lag period. The observations made here suggest that (1) changes in glucose 6-phosphate-independent glycogen synthase activity are at best only a qualitative measure of phosphoprotein phosphatase activity and (2) the decrease in glycogen synthase phosphatase activity during starvation is not sufficient to explain the differential glycogen synthase activation in adipose tissue from fed and starved rats. However, alterations in the phosphorylation state of glycogen synthase combined with decreased activity of phosphoprotein phosphatase, both as a consequence of starvation, could explain the apparent markedly decreased enzyme activation.  相似文献   
29.
Waters impacted by fecal pollution can exact high risks to human health and can result in financial losses due to closures of water systems used for recreation and for harvesting seafood. Identifying the sources of fecal pollution in water is paramount in assessing the potential human health risks involved as well as in assessing necessary remedial action. Recently, various researchers have used the ribotyping method to identify sources of bacterial indicators (Escherichia coli and enterococci) in environmental waters. While these studies have identified genotypic differences between human- and animal-derived indicators that are capable of differentiating organisms isolated from humans and various animal hosts, most have focused on organisms collected from a confined geographic area and have not addressed the question of whether these ribotype profiles are watershed specific or if they can be applied universally to organisms from other geographic locations. In this study, E. coli isolates were obtained from humans, beef cattle, dairy cattle, swine, and poultry from locations in northern, central, and southern Florida and were subjected to ribotyping analysis. The intent was to determine (i) if ribotype profiles are capable of discriminating the source of E. coli at the host species level and (ii) if the resulting fingerprints are uniform over an extended geographic area or if they can be applied only to a specific watershed. Our research indicated that, using a single restriction enzyme (HindIII), the ribotyping procedure is not capable of differentiating E. coli isolates from the different animal species sampled in this study. Results indicate, however, that this procedure can still be used effectively to differentiate E. coli as being either human or animal derived when applied to organisms isolated from a large geographic region.  相似文献   
30.
Journal of Mammalian Evolution - Late Pleistocene cave lions are one of the most iconic species of Northern Hemisphere Quaternary taphocoenoses. Despite their often-scarce record in cave...  相似文献   
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