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51.
Lynn E. Fletcher 《Behavioral ecology and sociobiology》2007,61(12):1809-1821
Group living confers both benefits and costs to the individuals involved. Benefits may include enhanced defense, thermoregulation,
and increased foraging efficiency while costs often involve competition for resources such as food, shelter, and mates. Communication
provides a medium of exchange among individuals engaged in either cooperative or competitive interactions. The functional
analysis of signals within groups therefore requires testing both cooperative and competitive functions, although the latter
is infrequently done. In this paper, I study the use of two vibrational signals in a gregarious, processionary Australian
sawfly larva, Perga affinis: tapping and contractions. Tapping involves striking the substrate with the sclerotized portion of the abdominal tail and
a contraction is a fast, whole-body twitch, which is both tactile and vibrational in its transmission. For tapping, I first
demonstrate that it is a form of communication, as tapping of one larva elicits tapping in another, and that it is transmitted
through substrate vibrations. I then test whether the signal is mostly cooperative or competitive in nature by examining it
in light of two hypotheses: (1) the Group Coordination hypothesis, stating that the signal functions to maintain group cohesiveness
and (2) the Competitive Signaling hypothesis, stating that tapping serves as a competitive assessment signal between larvae
while feeding. For contractions, I test only the group coordination hypothesis that they serve to coordinate and initiate
group movement. Results support the group coordination hypothesis for each signal. While feeding, lone larvae (without potential
competitors) were significantly more likely to tap than those in groups, and this trend continued in non-feeding situations.
Contractions regularly preceded periods of group movement during processions and were given with increasing frequency before
departure from preforaging clusters. The vibrational signals in this processionary species likely function cooperatively to
maintain group cohesiveness and coordinate movement. 相似文献
52.
Kevin J. Delaney J. Andrew Roberts George W. Uetz 《Behavioral ecology and sociobiology》2007,62(1):67-75
Male signaling behaviors are often studied in a single context but may serve multiple functions (e.g., in male–male competition
and female mate choice). We examined the issue of dual function male signals in a wolf spider species Schizocosa ocreata (Hentz) that displays the same species-specific signaling behaviors in both male–male and male–female contexts. These signaling
behaviors have been described as either aggression or courtship according to the context observed. We tested the possibility
of dual functions by comparing the relationship between behaviors and outcome of male–male contests (winner/loser) and male–female
mating encounters (mating success). Frequency, rate, and mean duration of signaling behaviors did not vary with outcome of
male–male contests, which appears instead to be based upon relative size and body mass. Winners of contests had significantly
greater body mass than losers, and greater mass relative to opponents was significantly associated with probability of winning.
Overall, signaling rates were much higher in male–female interactions than in male–male contests and were higher for males
that successfully mated than for those that did not mate. Mean duration of some male displays was also greater for males that
successfully mated. However, male size was not associated with probability of mating. Taken together, results suggest an intersexual
selection context for the current function of male signals in these wolf spiders and that increased display vigor is associated
with male mating success. 相似文献
54.
"三S"技术应用与环境科技发展 总被引:3,自引:0,他引:3
叙述了遥感,全球定位系统和地理信息系统和环境科技发展的关系,以及在环境科技中的实际应用,提出了在大力开展集RS,GPS,GIS于一体,适合环境科学应用的,综合多功能的“三S”技术,以适应可持续发展的需要。 相似文献
55.
In an analysis of North Sea eutrophication science and policies, focusing on the period 1980–2005, it was investigated how scientific information was used in policy-making. The analysis focused on the central assumptions of the rational policy-making model, i.e. that scientific information can be used to formulate decisions, based upon objective scientific information (rational decision-making), and secondly, can support implementing these decisions (rational management). In general terms, the following was concluded:
- •More knowledge has increased rather than reduced uncertainty;
- •In order to handle the problem of dealing with complexity and uncertainty at the political level, a simplification of facts has occurred, in this case focusing on nutrients as the main cause of the problem, at the same time excluding other possible causes;
- •Both the limited scientific view (i.e. the nutrient view) and the exaggeration of the seriousness of the problem (impacts, scope) have been used as an authoritative basis for the justification of political decisions. Both were not supported by the majority of the scientific community;
- •New scientific knowledge, not in support of existing policies, has been excluded from the policy process;
- •The science–policy interface, mainly consisting of “civil-servant scientists”, that emerged and increased its influence over the period of investigation, has been the central element in the simplification and exclusion process.
56.
57.
People spend most of their time indoors, where air pollution levels rival and often exceed those outdoors for a number of important pollutants. Yet, little is known about people’s knowledge of indoor environmental hazards. The purpose of the current study was to construct a measure of indoor environmental knowledge. A set of 78 true/false items were developed with input from a panel of experts. The set of items was truncated with traditional item analyses, resulting in a reliable set of 21 items (α = .79). Concurrent validity was established by a significant correlation between the indoor environmental knowledge (IEK) scale and an established measure of science literacy (r = 0.44, p < .001). Schema theory guided the assumption that the two measures should be related. Convergent validity was established by the significant regression of science literacy, formal education in science and math, and status as an engineering student on IEK scale score, accounting for 25% of the variance in the IEK scale score. Future research avenues are proposed and limitations are discussed. 相似文献
58.
Integration of environmental science in society is impeded by the large gap between science and policy that is characterised by weaknesses in societal relevance and dissemination of science and its practical implementation in policy. We analyse experiences from BONUS, the policy-driven joint Baltic Sea research and development programme (2007–2020), which is part of the European Research Area (ERA) and involves combined research funding by eight EU member states. The ERA process decreased fragmentation of Baltic Sea science and BONUS funding increased the scientific quality and societal relevance of Baltic Sea science and strengthened the science-policy interface. Acknowledging the different drivers for science producers (academic career, need for funding, peer review) and science users (fast results fitting policy windows), and realising that most scientists aim at building conceptual understanding rather than instrumental use, bridges can be built through strategic planning, coordination and integration. This requires strong programme governance stretching far beyond selecting projects for funding, such as coaching, facilitating the sharing of infrastructure and data and iterative networking within and between science producer and user groups in all programme phases. Instruments of critical importance for successful science-society integration were identified as: (1) coordinating a strategic research agenda with strong inputs from science, policy and management, (2) providing platforms where science and policy can meet, (3) requiring cooperation between scientists to decrease fragmentation, increase quality, clarify uncertainties and increase consensus about environmental problems, (4) encouraging and supporting scientists in disseminating their results through audience-tailored channels, and (5) funding not only primary research but also synthesis projects that evaluate the scientific findings and their practical use in society – in close cooperation with science users − to enhance relevance, credibility and legitimacy of environmental science and expand its practical implementation. 相似文献
59.
Natura 2000, the nature network based on the European Bird and Habitat Directives, is explicitly grounded on ecological science. To acquire a permit under the Dutch Nature Conservation Act, an appropriate assessment of significant effects must be conducted based on the best available scientific knowledge. In this way the scientific and policy world are directly linked. This article focuses on ‘significant effect’ as a boundary object to analyse how science–policy interactions shape the meaning and assessment of significant effect and how these interpretations influence the decision-making process. To this end, two conflicts over significant effect are investigated: the conflict over the 2006-spring permit for the mussel seed fishery, and the 2011 permit for the planned World Championship powerboat races. In both cases nature organisations started a court process against the government-granted permits in protest to the “no significant effect” claim, stating that there was insufficient certainty for this conclusion. These conflicts are approached as controversies between discourse coalitions with different interpretations of the ecological knowledge. We show how significant effect became a focal point in the controversies, limiting the debate to ecological arguments and science-based expertise, but also creating options for parties to advance their protest by articulating uncertainties. Only uncertainty of incomplete knowledge was explicitly addressed, excluding ambiguity of values and unpredictability of the actual ecosystem. We suggest that acknowledging the value aspect in disputes on significant effect would leave more space for effective solutions of the problems under debate. 相似文献
60.
We use the contingent valuation method to measure the amount citizens are willing to pay to improve scenic mountain-view amenities through the removal of billboards. Our approach addresses both the perceived property rights as well as the perceptions of the status quo in the southern Appalachian Mountains. We find that individuals who retire to the mountains have different preferences for land use and mountain views than individuals who have ancestors who lived in Watauga County. In the aggregate, we find that citizens are willing to pay almost one-half million dollars to remove billboards from Watauga County roadsides. This study provides insights to the debate surrounding land use along public roads. 相似文献