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21.
When climatic conditions change and become outside the range experienced in the past, species may show life‐history innovations allowing them to adapt in new ways. We report such an innovation for pied flycatchers Ficedula hypoleuca. Decades of breeding biological studies on pied flycatchers have rarely reported multiple breeding in this long‐distance migrant. In two populations, we found 12 recent incidents of females with second broods, all produced by extremely early laying females in warm springs. As such early first broods are a recent phenomenon, because laying dates have gradually advanced over time, this innovation now allows individual females to enhance their reproductive success considerably. If laying dates continue advancing, potentially more females may become multiple breeders and selection for early (and multiple) breeding phenotypes increases, which may accelerate adaptation to climatic change. 相似文献
22.
AIMS: The objective of the study was to assess the pharmacodynamic equivalence of LHRH analogue triptorelin 3-month and 28-day SR formulations. METHODS: Patients with documented locally advanced or metastatic prostate cancer were randomized to receive one injection of the 3-month formulation (n = 63) or three injections at 28-day intervals of the 28-day formulation (n = 68). Group-chemical castration rates defined as the percentage of patients reaching a testosterone plasma level =0.5 ng/ml were compared at D84 (i.e., 3 x 28 days). Testosterone, LH and triptorelin plasma profiles, and change from baseline in plasma PSA were assessed over 3 months (from baseline to D91). RESULTS: Chemical castration rates were 98 and 96% in the 3-month and 28-day formulation groups, respectively, with confidence interval (two-sided 94.2% CI) of [-8.1%; 9.6%]. Median times to reach chemical castration were 18.8 and 18.5 days (p = 0.86, log rank), respectively. Ratios for mean peak plasma levels and AUC(91) of the two formulations for both testosterone and LH fell within the [0.80; 1.25] equivalence interval. Mean PSA decreases from baseline at D91 were 91.0 and 91.7%, respectively (p = 0.73). CONCLUSION: Treatments with the two triptorelin formulations over 3 months are pharmacologically equivalent. 相似文献
23.
Both GW 《Immunology and cell biology》2004,82(2):189-195
The ovine adenovirus isolate OAdV287 is the prototype of the newly recognized genus of atadenoviruses. Although not as well studied as human mastadenoviruses, a substantial amount of work has now been carried out with this virus and an understanding of its interesting and unique properties is beginning to emerge. In this article the biology and biosafety profile of the virus is reviewed. This knowledge underpins the exploitation of the virus as a gene delivery vector. Its potential as a vaccine vector and its application to the treatment of prostate cancer is summarized and discussed. 相似文献
24.
25.
Judge S Judge A Grune T Leeuwenburgh C 《American journal of physiology. Regulatory, integrative and comparative physiology》2004,286(2):R254-R259
Lifelong caloric restriction (CR) reduces the rate of mitochondrial oxidant production and the accumulation of oxidized proteins and prevents some of the age-associated decline in 20S proteasome activity. However, few studies have investigated how rapidly the beneficial effects of CR take place. We investigated whether 2 mo of CR in 6-mo-old rats would be of sufficient duration to elicit these beneficial changes. Mitochondrial oxidant production was significantly diminished in the CR rats compared with the ad libitum-fed animals. Short-term CR also caused a significant decrease in mitochondrial superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities, but there were no differences in cytosolic SOD and GPX activities, whereas mitochondrial and cytosolic catalase (CAT) activity was increased with CR. However, protein carbonyl content was significantly elevated in both the mitochondrial and cytosolic fractions from CR rats. Of the three major 20S proteasome activities (chymotrypsin-like, trypsin-like, and peptidylglutamyl-peptide hydrolase), the peptidylglutamyl-peptide hydrolase activity was significantly elevated in the CR animals, possibly because of the fact that there were more oxidized proteins to be degraded. Although fewer oxidants were produced in the CR animals, it is possible that the ability to scavenge oxidants was transiently suppressed because of the reduction in mitochondrial antioxidant enzyme activities, which may explain the observed increases in carbonyl content. 相似文献
26.
Hasan MT Friedrich RW Euler T Larkum ME Giese G Both M Duebel J Waters J Bujard H Griesbeck O Tsien RY Nagai T Miyawaki A Denk W 《PLoS biology》2004,2(6):e163
Genetically encoded fluorescent calcium indicator proteins (FCIPs) are promising tools to study calcium dynamics in many activity-dependent molecular and cellular processes. Great hopes—for the measurement of population activity, in particular—have therefore been placed on calcium indicators derived from the green fluorescent protein and their expression in (selected) neuronal populations. Calcium transients can rise within milliseconds, making them suitable as reporters of fast neuronal activity. We here report the production of stable transgenic mouse lines with two different functional calcium indicators, inverse pericam and camgaroo-2, under the control of the tetracycline-inducible promoter. Using a variety of in vitro and in vivo assays, we find that stimuli known to increase intracellular calcium concentration (somatically triggered action potentials (APs) and synaptic and sensory stimulation) can cause substantial and rapid changes in FCIP fluorescence of inverse pericam and camgaroo-2. 相似文献
27.
Drew B Leeuwenburgh C 《American journal of physiology. Regulatory, integrative and comparative physiology》2003,285(5):R1259-R1267
The production of ATP is vital for muscle contraction, chemiosmotic homeostasis, and normal cellular function. Many studies have measured ATP content or qualitative changes in ATP production, but few have quantified ATP production in vivo in isolated mitochondria. Because of the importance of understanding the energy capacity of mitochondria in biology, physiology, cellular dysfunction, and ultimately, disease pathologies and normal aging, we modified a commercially available bioluminescent ATP determination assay for quantitatively measuring ATP content and rate of ATP production in isolated mitochondria. The bioluminescence assay is based on the reaction of ATP with recombinant firefly luciferase and its substrate luciferin. The stabilities of the reaction mixture as well as relevant ATP standards were quantified. The luminescent signals of the reaction mixture and a 0.5 microM ATP standard decreased linearly at rates of 2.16 and 1.39% decay/min, respectively. For a 25 microM ATP standard, the luminescent signal underwent a logarithmic decay, due to intrinsic deviations from the Beer-Lambert law. Moreover, to test the functionality of isolated mitochondria, they were incubated with 1 and 5 mM oligomycin, an inhibitor of oxidative phosphorylation. The rate of ATP production in the mitochondria declined by 34 and 83%, respectively. Due to the sensitivity and stability of the assay and methodology, we were able to quantitatively measure in vivo the effects of age and caloric restriction on the ATP content and production in isolated mitochondria from the brain and liver of young and old Fischer-344 rats. In both tissues, neither age nor caloric restriction had any significant effect on the ATP content or the rate of ATP production. This study introduces a highly sensitive, reproducible, and quick methodology for measuring ATP in isolated mitochondria. 相似文献
28.
Species differ enormously in their territorial systems. Some species defend only small areas surrounded by undefended space, while others defend large contiguous territories. Using an optimization approach, we show that this variation can be explained from the density of two types of resources: divisible and nondivisible. We assume that benefits of territories are monotonously related to the defended amount of divisible resources (hereafter called food). In contrast, no benefits are obtained without a nondivisible resource (hereafter called nest site) in the territory, while more than one nest site does not further increase the benefits. The optimal territory size depends on the relative abundance of these resources. With a low density of nest sites, the optimal territory size is small and includes only the nest site. If the density of nest sites is relatively large, the optimal territory size is high, and territories are contiguous. Competition for these different resources yields contrasting patterns of how populations are regulated. If there is mainly competition for nest sites, we expect density-dependent exclusion through territoriality and no density-dependent reproduction. When competition is mainly for food, we expect density-dependent reproduction because optimal territory size will be compressed at higher densities, resulting in lower reproductive success. These predicted patterns indeed are observed in some well-studied passerine species for which both the territorial system and the occurrence of density dependence is known. 相似文献
29.
Nonhuman adenoviruses, including those of the genus Atadenovirus, have the potential to serve as vectors for vaccine and gene therapy applications in humans, since they are resistant to preexisting immunity induced by human adenoviruses in the majority of the population. In this study, we elucidate the outcome of infection by ovine adenovirus type 7 isolate 287 (OAdV) of several nonovine cell types. We show here that OAdV infects a wide range of nonovine cells but is unable to complete its replication cycle in any of them. In nonovine, nonfibroblast cells, viral replication is blocked at an early stage before the onset of, or early in, DNA replication. Some fibroblasts, on the other hand, allow viral DNA replication but block virus production at a later stage during or after the translation of late viral proteins. Late viral proteins are expressed in cells where viral DNA replication takes place, albeit at a reduced level. Significantly, late proteins are not properly processed, and their cellular distribution differs from that observed in infected ovine cells. Thus, our results clearly show that OAdV infection of all nonovine cells tested is abortive even if significant viral DNA replication occurs. These findings have significant positive implications with respect to the safety of the vector system and its future use in humans. 相似文献
30.
Karreman C 《Bioinformatics (Oxford, England)》2002,18(6):884-885
SUMMARY: AiO (All in One) is a program for Windows, that combines typical DNA/protein features such as plasmid map drawing, finding of ORFs, translate, backtranslate and high quality printing with a number of databases. These databases allow the management of oligonucleotides, oligonucleotide-manufacturers, restriction enzymes, structural DNA and program users in a multi-user/multi-group environment. AVAILABILITY: An AiO specific website, with the possibility to download is at: http://134.99.88.55/aio/ SUPPLEMENTARY INFORMATION: Examples with screen shots- http://134.99.88.55/aio/ : Manual (in PDF format)-http://134.99.88.55/aio/manual.pdf 相似文献