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61.
INTRODUCTION: Cycling accidents in Australia, especially those resulting in head injuries, are a substantive cause of death and disability; but despite legislation and evidence that helmets reduce the risk of head injury, few adolescents wear them. METHOD: This study employed a revised version of the Theory of Planned Behavior (TPB; [Ajzen, I. (1991). The theory of planned behavior. Organizational Behavior and Human Decision Processes, 50, 179-211]) to investigate the determinants of helmet use among a sample of adolescents. Participants in the initial data collection were 294 high school students in Year 8 and Year 11, with 266 completing a follow-up questionnaire measuring behavior over the previous two weeks. RESULTS: Social norms, perceptions of control, and past behavior significantly predicted intentions to use helmets and perceptions of control and past behavior predicted actual helmet use. CONCLUSIONS: Strengthening the routine of helmet use and building young people's confidence that they can overcome any perceived barriers to helmet use will improve adherence to helmet wearing behavior. 相似文献
62.
Dietary characterization of the hominoid Khoratpithecus (Miocene of Thailand): evidence from dental topographic and microwear texture analyses 总被引:1,自引:0,他引:1
The genus Khoratpithecus, a hominoid thought to be related to the orangutan lineage, is represented by two known fossil species K. chiangmuanensis and K. piriyai. Both were discovered in Southeast Asia (Thailand) and are dated to the Middle and Late Miocene, respectively. In this study, dental topographic and microwear texture analyses were used to examine molars from both of these species, with the goal of understanding their dietary preferences. Although sample sizes are small for Khoratpithecus, available data are compared to that collected for extant apes. Environmental evidence, such as botanical remains and sedimentological data, is also considered for comparisons with dietary reconstruction. Results from dental topographic analysis suggest that the two fossil species were better adapted to a diet of fruits than to one of leaves, much like the living orangutan or chimpanzee. Results from microwear texture analysis further support this, suggesting that Khoratpithecus preferred soft fruits to hard fruits or seeds. And finally, the botanical and sedimentological evidence point to environments for Khoratpithecus that would have been compatible with a fruit-eating species. Given the small sample sizes available for analysis, however, definitive judgments are not yet possible at this time. 相似文献
63.
64.
David M Lodge Susan Williams Hugh J MacIsaac Keith R Hayes Brian Leung Sarah Reichard Richard N Mack Peter B Moyle Maggie Smith David A Andow James T Carlton Anthony McMichael 《Ecological applications》2006,16(6):2035-2054
The Ecological Society of America has evaluated current U.S. national policies and practices on biological invasions in light of current scientific knowledge. Invasions by harmful nonnative species are increasing in number and area affected; the damages to ecosystems, economic activity, and human welfare are accumulating. Without improved strategies based on recent scientific advances and increased investments to counter invasions, harm from invasive species is likely to accelerate. Federal leadership, with the cooperation of state and local governments, is required to increase the effectiveness of prevention of invasions, detect and respond quickly to new potentially harmful invasions, control and slow the spread of existing invasions, and provide a national center to ensure that these efforts are coordinated and cost effective. Specifically, the Ecological Society of America recommends that the federal government take the following six actions: (1) Use new information and practices to better manage commercial and other pathways to reduce the transport and release of potentially harmful species; (2) Adopt more quantitative procedures for risk analysis and apply them to every species proposed for importation into the country; (3) Use new cost-effective diagnostic technologies to increase active surveillance and sharing of information about invasive species so that responses to new invasions can be more rapid and effective; (4) Create new legal authority and provide emergency funding to support rapid responses to emerging invasions; (5) Provide funding and incentives for cost-effective programs to slow the spread of existing invasive species in order to protect still uninvaded ecosystems, social and industrial infrastructure, and human welfare; and (6) Establish a National Center for Invasive Species Management (under the existing National Invasive Species Council) to coordinate and lead improvements in federal, state, and international policies on invasive species. Recent scientific and technical advances provide a sound basis for more cost-effective national responses to invasive species. Greater investments in improved technology and management practices would be more than repaid by reduced damages from current and future invasive species. The Ecological Society of America is committed to assist all levels of government and provide scientific advice to improve all aspects of invasive-species management. 相似文献
65.
Rare royal families in honeybees, Apis mellifera 总被引:1,自引:0,他引:1
Moritz RF Lattorff HM Neumann P Kraus FB Radloff SE Hepburn HR 《Die Naturwissenschaften》2005,92(10):488-491
The queen is the dominant female in the honeybee colony, Apis mellifera, and controls reproduction. Queen larvae are selected by the workers and are fed a special diet (royal jelly), which determines
caste. Because queens mate with many males a large number of subfamilies coexist in the colony. As a consequence, there is
a considerable potential for conflict among the subfamilies over queen rearing. Here we show that honeybee queens are not
reared at random but are preferentially reared from rare “royal” subfamilies, which have extremely low frequencies in the
colony's worker force but a high frequency in the queens reared. 相似文献
66.
Genetic variation in honeybee, Apis mellifera, populations can be considerably influenced by breeding and commercial introductions, especially in areas with abundant beekeeping. However, in southern Africa apiculture is based on the capture of wild swarms, and queen rearing is virtually absent. Moreover, the introduction of European subspecies constantly failed in the Cape region. We therefore hypothesize a low human impact on genetic variation in populations of Cape honeybees, Apis mellifera capensis. A novel solution to studying genetic variation in honeybee populations based on thelytokous worker reproduction is applied to test this hypothesis. Environmental effects on metrical morphological characters of the phenotype are separated to obtain a genetic residual component. The genetic residuals are then re-calculated as coefficients of genetic variation. Characters measured included hair length on the abdomen, width and length of wax plate, and three wing angles. The data show for the first time that genetic variation in Cape honeybee populations is independent of beekeeping density and probably reflects naturally occurring processes such as gene flow due to topographic and climatic variation on a microscale. 相似文献
67.
This paper summarizes those factors that have contributed to the degradation of the mangroves in El Salvador, and examines the implications of proposed changes in property rights to the mangroves for poor coastal communities. Current patterns of extraction and conversion in the mangrove ecosystem in El Salvador can be viewed through an entitlement lens that confers property right upon some actors, for certain uses, and denies them to others. Unfortunately, the present system of laws and regulations that governs resource use in the mangroves is contradictory and confusing. A number of laws currently are active that give entirely different directives about the use and transformation of the ecosystem. The rational and sustainable management of the mangroves cannot be secured without a redefinition of entitlement rights. This redefinition of entitlements, however, should take into account the needs of those whose livelihoods are intimately connected to the health of the ecosystem. 相似文献
68.
Fisheries catches are known to be widely underreported, and much of their value flows in informal markets. Goods and services that are not directly sold in a market also have a corresponding economic value, here termed ‘shadow value’, which can apply to discarded fish—or those that are consumed but not sold (e.g., subsistence catches). Here, we estimate the monetary value of fisheries catches in Panama that are landed but not reported, or that are discarded at sea; this includes catches from artisanal and industrial fleets, as well as recreational and subsistence fisheries. Based on available data, we estimate that the market and shadow value of unreported catches in Panama in 2010 was around US$92 million, equal to approximately 43% of the total reported landed value. In the case of discarded fish, the shadow value represents the potential but entirely unrealized economic benefit of landing such fish; in the case of unreported landings, unreported market value represents only the first link in the potentially sophisticated informal seafood economy. One must be careful in considering these results for policy. It is possible that, rather than seeking to capture these ‘lost’ benefits, fish that are discarded or unreported should not have been caught at all, for example, if they are juveniles or of threatened species; conversely, unreported subsistence catches are crucial for food security throughout the world. These results help contextualize the scale of unreported fisheries in economic terms, and can inform subsequent policies and strategies to ensure social, ecological, and economic sustainability. 相似文献
69.
This contribution presents an introduction to a series of papers on integrated scientific approaches presented at the San
Feliu Euroconference on transdisciplinary coastal management research. Coastal management is a challenging area for the integration
of social and natural sciences. The papers provide a basis for ongoing cross-disciplinary research. 相似文献
70.
Sarah J. Cowell Walter Wehrmeyer Peter W. Argust J. Graham S. Robertson 《Resources Policy》1999,25(4):421
This paper reflects on how sustainability is being interpreted both theoretically and in practice for the primary extraction industries. Two contrasting perspectives can be adopted: one states that continued extraction of non-renewable resources is a necessary part of sustainable development, whilst the other states that extraction of these resources must be greatly reduced or even eliminated. It is shown that these different approaches can be traced back to underlying, often unarticulated, assumptions about the acceptability of trade-offs between different societal goals; attitudes towards uncertainties in scientific analysis and the reliability of management systems; and the perceived appropriateness of system boundaries at different conceptual scales. These assumptions are founded in the self-perception of organisations and individuals about their roles in society, and the cultural context within which these organisations and individuals define their raison d'être. 相似文献