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11.
We provide guidance for monitoring whether human activities affect the physiology or behavior of marine mammals and, if so, whether those effects may lead to changes in survival and reproduction at the population level. We suggest that four elements be included in designing and implementing such a monitoring program. The first is development of a theory of change: a set of mechanistic hypotheses that outline why a given activity might be expected to have one or more measurable effects on individuals and populations, and ideally the magnitude, timing, and duration of the effects. The second element, definition of biologically meaningful effect sizes, ultimately facilitates the development of a monitoring program that can detect those magnitudes of effect with the desired levels of precision. The third element, selection of response variables for monitoring, allows inference to whether observed changes in the status of individuals or populations are attributable to a given activity. Visual observations, passive acoustic and tagging instruments, and direct physical measurements all can provide data that facilitate quantitative hypothesis testing. The fourth element is specification of the temporal sequence of monitoring. These elements also can be used to inform monitoring of the responses of other taxonomic groups to human activities.  相似文献   
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Cells harvested from Fanconi anemia (FA) patients show an increased hypersensitivity to the multifunctional DNA damaging agent mitomycin C (MMC), which causes cross-links in DNA as well as 7,8-dihydro-8-oxoguanine (8-oxoG) adducts indicative of escalated oxidative DNA damage. We show here that the Drosophila multifunctional S3 cDNA, which encodes an N-glycosylase/apurinic/apyrimidinic (AP) lyase activity was found to correct the FA Group A (FA(A)) and FA Group C (FA(C)) sensitivity to MMC and hydrogen peroxide (H2O2). Furthermore, the Drosophila S3 cDNA was shown to protect AP endonuclease deficient E. coli cells against H(2)O(2) and MMC, and also protect 8-oxoG repair deficient mutM E. coli strains against MMC and H2O2 cell toxicity. Conversely, the human S3 protein failed to complement the AP endonuclease deficient E. coli strain, most likely because it lacks N-glycosylase activity for the repair of oxidatively-damaged DNA bases. Although the human S3 gene is clearly not the genetic alteration in FA cells, our results suggest that oxidative DNA damage is intimately involved in the overall FA phenotype, and the cytotoxic effect of selective DNA damaging agents in FA cells can be overcome by trans-complementation with specific DNA repair cDNAs. Based on these findings, we would predict other oxidative repair proteins, or oxidative scavengers, could serve as protective agents against the oxidative DNA damage that occurs in FA.  相似文献   
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In personal interviews, people surrendering their dogs and cats to 12animal shelters in 4 regions of the country discussed their reasons for relinquishing their companion animals and answered questions about their own characteristics and those of their pet. The interviews identified 71 reasons for relinquishment. Personal issues lead the class of reasons for relinquishment of cats and ranked 3rd among those given for relinquishment of dogs. The top 3 health and personal issues cited for giving up cats were allergies of a family member to cats, owner's personal problems, and anew baby. For dogs, the top 3 reasons cited were lack of time for the dog, owner's personal problems, and allergies. Analysis of these health and personal issues suggests that education and counseling before and after acquisition of a pet, as well as the availability of temporary accommodations for pets during times of personal crisis, may reduce relinquishments.  相似文献   
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Temperate regions of Australia have extensive commercial plantations of Monterey pine, Pinus radiata D. Don. Replacement of indigenous forests by P. radiata is likely to have significant effects on assemblages of native Lepidoptera, and has been considered a major threat to native fauna through displacing native species. However, many species of Lepidoptera, including ennomine geometrid moths in the genus Chlenias Guenèe, have adopted P. radiata as a larval host. Comparisons were made of oviposition preferences and nutritional ecology of Chlenias auctaria Guenée on P. radiata and two native host plants [Acacia mearnsii De Wild. (Mimosaceae) and Eucalyptus obliqua LHérit (Myrtaceae)]. Females showed no significant oviposition preference for any of the three hosts. Growth of sixth instar larvae was significantly less on P. radiata than on the native hosts. Pupal weights were significantly lower, suggesting that the fitness of moths reared on P. radiata will be significantly reduced. The life history strategy of C. auctaria, which includes dispersal of first instar larvae by ballooning, may predispose this species to feed on poor quality hosts, and this may be common to other polyphagous species found feeding on P. radiata in southern hemisphere plantations. The impact of P. radiata may have a long term effect on lepidopteran communities, beyond the simple replacement of indigenous host plants leading to extirpations of feeding specialists.  相似文献   
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A 14-year-old Native American girl from the Iroquois Nation was referred as a potential patient with the syndrome of Apparent Mineralocorticoid Excess. Instead, her evaluation revealed resistance to glucocorticoids, mineralocorticoids, and androgens. She lacked Cushingoid features in spite of significantly high cortisol levels. Menstruation was regular and there was no clinical evidence of masculinization despite high serum androgen levels in the male range. The patient's sister had similar clinical features. Partial resistance to exogenous glucocorticoid and mineralocorticoid administration was well demonstrated in both patients. It is proposed that these patients represent the first cases of partial resistance to multiple steroids, possibly owing to a coactivator defect.  相似文献   
18.
Rad52 protein plays a central role in double strand break repair and homologous recombination in Saccharomyces cerevisiae. We have identified a new mechanism by which Rad52 protein stimulates Rad51 protein-promoted DNA strand exchange. This function of Rad52 protein is revealed when subsaturating amounts (relative to the single-stranded DNA concentration) of replication protein-A (RPA) are used. Under these conditions, Rad52 protein is needed for extensive DNA strand exchange. Interestingly, in this new role, Rad52 protein neither acts simply as a single strand DNA-binding protein per se nor, in contrast to its previously identified stimulatory roles, does it require physical interaction with RPA because it can be substituted by the Escherichia coli single strand DNA-binding protein. We propose that Rad52 protein acts by stabilizing the Rad51 presynaptic filament.  相似文献   
19.
Formal listing of species for protection is a responsible action in conferring conservation priority, and must be undertaken as objectively as possible, and redundant entries that distract from priority need be removed. Diverse groups, such as invertebrates, pose problems for listing because criteria of rarity and threat are often confounded. Species de-listed as a result of recovery action are a special category, in which conservation investment has been made; the principle of recognising these as rehabilitated species with a formal duty of aftercare is discussed. Although the paper focuses on invertebrates in Australia, the principles have wider relevance in species-level conservation focus.  相似文献   
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New DC  Tsim ST  Wong YH 《Neuro-Signals》2003,12(2):59-70
The isolation and characterization of multiple melatonin receptors in a wide range of tissues and cells signifies the functional diversity of melatonin. In different cellular environments, melatonin can regulate distinct second messengers or even positively or negatively regulate the same signal transduction pathway. The capacity by which melatonin receptors modulate the activities of various effector molecules is determined by the complement of signaling components present in any particular cell type. The specific interactions between many signaling molecules have been discerned in an increasing number of cellular systems and this information is being used to explain the physiological actions of melatonin. This review will attempt to summarize recent research by many groups that has revealed numerous subtleties of the melatonin-coupled signaling pathways.  相似文献   
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