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291.
Clare J. Napper Stuart P. Sharp Andrew McGowan Michelle Simeoni Ben J. Hatchwell 《Behavioral ecology and sociobiology》2013,67(12):2029-2039
Kin selection has played an important role in the evolution and maintenance of cooperative breeding behaviour in many bird species. However, although relatedness has been shown to affect the investment decisions of helpers in such systems, less is known about the role that kin discrimination plays in other contexts, such as communal roosting. Individuals that roost communally benefit from reduced overnight heat loss, but the exact benefit derived depends on an individual's position in the roost which in turn is likely to be influenced by its position in its flock's dominance hierarchy. We studied the effects of kinship and other factors (sex, age, body size and flock sex ratio) on an individual's roosting position and dominance status in captive flocks of cooperatively breeding long-tailed tits Aegithalos caudatus. We found that overall, kinship had little influence on either variable tested; kinship had no effect on a bird's position in its flock's dominance hierarchy and the effect of kinship on roosting position was dependent on the bird's size. Males were generally dominant over females and birds were more likely to occupy preferred roosting positions if they were male, old and of high status. In this context, the effect of kinship on social interactions appears to be less important than the effects of other factors, possibly due to the complex kin structure of winter flocks compared to breeding groups. 相似文献
292.
Graves AK Hagedorn C Teetor A Mahal M Booth AM Reneau RB 《Journal of environmental quality》2002,31(4):1300-1308
Antibiotic resistance analysis (ARA) was used to determine if enterococci of human origin were present in a stream (Spout Run) that passes through a rural nonsewered community (Millwood, VA). Millwood consists of 82 homes, all served by individual septic systems, and Spout Run drains a 5,800-ha karst topography watershed that contains large populations of livestock and wildlife. Periodic monitoring by state regulatory officials had resulted in Spout Run being placed on the Virginia impaired stream list and Millwood being categorized as an at-risk community. Stream samples were collected monthly and analyzed for fecal coliforms and enterococci (May 1999-May 2000); ARA was performed on enterococci stream isolates on a quarterly basis. All 117 stream samples were positive for fecal coliforms, and 32% exceeded the Virginia recreational water standard (1,000 fecal coliforms/100 mL). A library of 1,174 known source Enterococcus isolate antibiotic resistance profiles was constructed, and yielded correct classification rates of 94.6% for 203 human isolates, 93.7% for 734 livestock isolates, and 87.8% for 237 wildlife isolates. Antibiotic resistance analysis of 2,012 enterococcal isolates recovered from stream samples indicated isolates of human origin appeared throughout the stream as it passed through Millwood, with a yearly average of approximately 10% human, 40% wildlife, and 50% livestock. There were no human origin isolates in samples collected upstream from Millwood, and the percent human origin isolates declined downstream from Millwood. While a human signature was found in Spout Run, it was small compared with the proportion of isolates from livestock and wildlife. 相似文献
293.
The Reproductive Health Response in Conflict (RHRC) Consortium designed a standardised questionnaire to measure gender-based violence (GBV) prevalence in conflict-affected settings. A preliminary field test was undertaken July-August 2002 in one urban and one rural district in East Timor to assess the prevalence of GBV among women 18-49 years of age during and after conflict. The field test used a cross-sectional survey design with a two-stage random selection process. During the year preceding East Timor's 1999 crisis, 23.8 per cent of respondents reported physical assault by an intimate partner; this rate was not significantly different in the year preceding the survey (24.8 per cent). Assault by perpetrators outside the family declined significantly from 24.2 per cent during the crisis to 5.8 per cent post-crisis for physical assault (p<.001) and 22.7 per cent during the crisis to 9.7 per cent post-crisis for sexual assault (p=0.046). The field test stimulated and informed additional research in East Timor, and the complementary findings of these research initiatives continue to be used to develop local policies and programming to prevent and address GBV. 相似文献
294.
The United States Environmental Protection Agency (US EPA) and the Chlorine Chemistry Council, the Chemical Manufacturers Association, and others have been embroiled in a legal challenge concerning the US EPA's "reversal" regarding the scientific assessment of chloroform's carcinogenicity. This issue arose during the US EPA's November 1998 promulgation of a Maximum Contaminant Level Goal for chloroform in the Stage 1 Final Rules for Disinfectants and Disinfection Byproducts in drinking water. In this paper we adopt a claimsmaking approach: to trace the development and outcome of the chloroform court challenge in the USA, to examine the construction of scientific knowledge claims concerning chloroform risk assessments, and to investigate how different interpretations of scientific uncertainties regarding the evidence are contested when such uncertainties are brought into a regulatory and judicial arena. This "science war" (Chlorine Chemistry Council and others v. US EPA and others) took place in the US Court of Appeals for the District of Columbia Circuit. The scientific "authority" in the construction of scientific claims in this dispute is based on the International Life Sciences Institute expert panel report on chloroform. Examining these science wars is important because they signal critical shifts in science policy agendas. The regulatory outcome of the chloroform science war in the United States can have profound implications for the construction and acceptance of scientific claims regarding drinking water in other jurisdictions (e.g., Canada). In this challenge, we argue that the actors involved in the dispute constructed "boundaries" around accepted and credible scientific claims. 相似文献
295.
Teen drivers are at high risk for car crashes, especially during their first years of licensure. Providing novice teen drivers and their parents with a means of identifying their risky driving maneuvers may help them learn from their mistakes, thereby reducing their crash propensity. During the initial phase of learning, adult or parental supervision often provides such guidance. However, once teens obtain their license, adult supervision is no longer mandated, and teens are left to themselves to continue the learning process. This study is the first of its type to enhance this continued learning process using an event-triggered video device. By pairing this new technology with parental feedback in the form of a weekly video review and graphical report card, we extend parents' ability to teach their teens even after they begin driving independently. Twenty-six 16- to 17-year-old drivers were recruited from a small U.S. Midwestern rural high school. We equipped their vehicles with an event-triggered video device, designed to capture 20-sec clips of the forward and cabin views whenever the vehicle exceeded lateral or forward threshold accelerations. Preliminary findings suggest that combining this emerging technology with parental weekly review of safety-relevant incidents resulted in a significant decrease in events for the more at-risk teen drivers. Implications for how such an intervention could be implemented within GDL are also discussed. 相似文献
296.
Sharks are apex predators, and their evolutionary success is in part due to an impressive array of sensory systems, including
vision. The eyes of sharks are well developed and function over a wide range of light levels. However, whilst close relatives
of the sharks—the rays and chimaeras—are known to have the potential for colour vision, an evolutionary trait thought to provide
distinct survival advantages, evidence for colour vision in sharks remains equivocal. Using single-receptor microspectrophotometry,
we measured the absorbance spectra of visual pigments located in the retinal photoreceptors of 17 species of shark. We show
that, while the spectral tuning of the rod (wavelength of maximum absorbance, λmax 484–518 nm) and cone (λmax 532–561 nm) visual pigments varies between species, each shark has only a single long-wavelength-sensitive cone type. This
suggests that sharks may be cone monochromats and, therefore, potentially colour blind. Whilst cone monochromacy on land is
rare, it may be a common strategy in the marine environment: many aquatic mammals (whales, dolphins and seals) also possess
only a single, green-sensitive cone type. It appears that both sharks and marine mammals may have arrived at the same visual
design by convergent evolution. The spectral tuning of the rod and cone pigments of sharks is also discussed in relation to
their visual ecology. 相似文献
297.
298.
Soares Ana Paula S. Mothé Cheila G. Mothé Michelle G. 《Journal of Polymers and the Environment》2022,30(4):1380-1390
Journal of Polymers and the Environment - The present research aims to propose a comparative life cycle assessment (LCA) between the coffee capsules recycling process and the process of obtaining... 相似文献