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291.
Individuals’ food choices are intimately connected to their self-images and world views. Some dietary choices adopted by consumers
pose restrictions on their use of genetically modified food (GMF). It is quite generally agreed that some kind of labeling
is necessary for respecting consumers’ autonomy of choice regarding GMF. In this paper, we ask whether the current practice of mandatory
labeling of GMF products in the European Union is a sufficient administrative procedure for respecting consumers’ autonomy. Three issues concerning this question are discussed. First,
we argue that labeling needs to be accompanied by relevant and understandable information on genetic modification, genetically
modified food, and the European practice of GMF labeling. Second, we claim that this type of informing makes it less likely
that consumers start to avoid GMF products just because labels make them suspicious of the products. It is further noted that
even though some consumers may react to labels this way, labels do not restrict their autonomy of choice. Third, a need for
more precise labels indicating the source of the transferred gene is considered. It is found out that such labels are not
morally necessary when also non-GMF products are available and no relevant differences (such as differences in price and healthiness)
exist between them and GMF products. However, in some other cases more precise labels may be needed for respecting consumers’
autonomy of choice. 相似文献
292.
Jane L. Halliday Rosemary Warren Geraldine McDonald Pranee Liamputtong Rice Robin J. Bell Lyndsey F. Watson 《黑龙江环境通报》2001,21(10):842-847
Forty percent of pregnant women aged 37 years and over do not have prenatal diagnosis despite being eligible for a free test. The present study aimed to determine how often, and which, untested women were making a choice about this, how many declined an offer and why. A questionnaire was given to untested women, aged 37 years and over, at no less than 24 weeks gestation. A total of 375 (81.5%) women declined, 72 (16%) were not offered a test and 13 presented too late antenatally. There was a three-fold increased likelihood (OR 3.10 95% CI 1.44, 6.65) of no offer for urban non-English speaking background women, compared with the reference group (metropolitan, English speaking). Unpartnered women were also significantly less likely to receive an offer (OR 3.18, 95% CI 1.19, 8.46). Risk to the baby was the main reason for declining. When offered non-invasive prenatal screening, most decliners of prenatal diagnosis accepted, even those who declined because they were opposed to abortion. We estimate that overall 33% of older pregnant women were being offered and declining amniocentesis and/or chorion villus sampling (CVS). Only 6% were not offered a test, but this small proportion is over-represented by minority groups who must be given equal opportunity to make this choice. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
293.
Thomas J. Valone 《Behavioral ecology and sociobiology》2007,62(1):1-14
Public information (PI), a form of indirect social information, is used by individuals to estimate the quality of environmental
parameters. It can be acquired in two ways. One way is by noting the performance of others. The other way it can be acquired
is by noting the behavioral decisions of other individuals. Performance-based PI has been observed most often in the context
of food and breeding patch estimation, as well as by individuals eavesdropping on contests between others in the context of
assessing the fighting ability of opponents and the quality of mates. Evidence for the acquisition of PI from behavioral decisions
of others comes mostly from studies of copying behavior, although recent work suggests that it also occurs when individuals
estimate the tendency of others to be altruistic. PI use appears to be widespread across many taxa, although most work has
been conducted on birds and fish. Absent from the literature are clear examples of PI use in mammals. The use of PI appears
to often depend on its cost of acquisition and whether it contradicts an individual’s personal prior experience. PI can be
an important benefit of associating with others. 相似文献
294.
Bernd Page Wolfgang Kreutzer 《Environmental science and pollution research international》2006,13(6):441-441
Summary The main readership are students in the field of informatics. In most parts, other interested scientists from environmental
disciplines get some insights in the field of environmental modelling and software. The book can be recommended broadly. With
the last chapter ‘Simulation in Practice’, this work may also be useful for commercial application. With chapter 14, the authors
contribute to the increasingly important topic of E-Learning. 相似文献
295.
296.
Contrary to classical sexual selection theories, females of many taxa mate with multiple males during one reproductive cycle. In this study, we conducted an experiment on the “trade-up hypothesis”, which proposes that females remate if a subsequently encountered male is potentially superior to previous mates to maximize the genetic quality of their offspring. We presented bank vole females (Clethrionomys glareolus) sequentially with two males of known dominance rank in different orders, i.e., either first subordinate and second dominant, first dominant and second subordinate, or two males that were equal in dominance (high ranking) and observed their mating behavior. We found that 92% of the females mated multiply and did not base their remating decision on male social status. Therefore, polyandry cannot be explained by the “trade-up hypothesis” based on dominance rank in this species. However, we found that dominant males sired significantly more offspring than subordinate males. This varied according to mating order: dominant males sired more offspring when they were second than when they were first. Moreover, litter sizes were significantly smaller when the dominant male was first (smallest relative success of dominant males) compared to litter sizes when mating order was reversed or both males equal in status. Our results suggest that even though multimale mating includes males that are of poorer quality and thus potentially decreases the fitness of offspring, most of a female’s offspring are sired by dominant males. Whether this is due to cryptic female choice, sperm competition, or a combination of both, remains to be tested. 相似文献
297.
The social environment of many species includes synchronous maturation of siblings in family groups, followed by limited dispersal
of adults from their natal site. Under these conditions, females may experience high encounter rates with same-age siblings
during mate searching, increasing their risk of inbreeding. If inbreeding depression occurs, mating with a sibling is often
considered maladaptive; however, in some contexts, the inclusive fitness benefits of inbreeding may outweigh the costs, favoring
females that tolerate some level of inbreeding depression. We evaluated mating patterns in the treehopper Umbonia crassicornis, a semelparous species in which females encounter same-age siblings during mate searching. A female U. crassicornis that mates with a brother suffers from inbreeding depression. We used a free-choice mating design that offered females simultaneous
mating opportunities with three groups of males: siblings, same-age nonsiblings, and older nonsiblings. These groups represent
the types of males typically encountered by females during mate searching. Our goal was to assess whether mating patterns
were influenced by inbreeding avoidance by evaluating two hypotheses: kin discrimination and age-based mating (older males
cannot be siblings in this species). There was no difference in the proportions of females mating with siblings vs nonsiblings,
suggesting an absence of kin discrimination. However, females mated with a greater proportion of older vs younger males. Given
that females do not avoid siblings as mates despite a cost to inbreeding, our results provide a possible example of inbreeding
tolerance. We also discuss some factors that may have contributed to the mating advantage of older males. 相似文献
298.
Some mate choice theories propose that only male signals that are honest and condition-dependent can be stable, while another
hypothesis states that males evolve signals that exploit the sensory system of females. However, sensory traps might evolve
into honest signals if they are differentially costly for males. We tested whether a pre-existing sensory bias for food chemicals
explained chemosensory preferences of female Iberian rock lizards for male scents. We manipulated hunger levels of females
and found that food-deprived females had increased chemosensory responses to chemical stimuli from both invertebrate prey
and femoral secretions of males, but not to control water. Further tests suggested that cholesta-5,7-dien-3-ol (provitamin
D3), a lipid found in both prey and males’ scent, may be one of the chemicals eliciting these responses. Moreover, hungry females
spent more time on scent marks of males that had experimentally increased cholesta-5,7-dien-3-ol than on scent marks of males
alone, whereas for control females this effect was not significant. We suggest that preexisting sensory bias for essential
nutrients (i.e., provitamin D) may be the origin of similar female responses to male chemicals. However, previous studies
have suggested that the allocation of these chemicals to ornaments is costly and only high quality males can afford it. Therefore,
preexisting sensory bias for essential nutrients may further allow the evolution and maintenance of honest sexual displays. 相似文献
299.
从全人类和长暑期的角度来看,可持续发展是人类社会发展的必然,但在短时期内,特别是在特定的的国家和地区范围内,却不一定是必然的。这种必然性的实现领带于各国政府对国家发展战略的选择。本文在分析先期工业化国家发展路径的基础上,提出了国家发展路径的几种可能情形.论述了发展路径依赖于政府负责任的赖选择关系,并初步分析了可能的选择空间。最后.论文指出中国的科学发展观是超越了转移、转嫁的发展模式的转变.是对人类社会负责任的符合可持续发展要求的战略选择。 相似文献
300.
Andrew Sih Sean F. Hanser Katherine A. McHugh 《Behavioral ecology and sociobiology》2009,63(7):975-988
Until recently, few studies have used social network theory (SNT) and metrics to examine how social network structure (SNS)
might influence social behavior and social dynamics in non-human animals. Here, we present an overview of why and how the
social network approach might be useful for behavioral ecology. We first note four important aspects of SNS that are commonly
observed, but relatively rarely quantified: (1) that within a social group, differences among individuals in their social
experiences and connections affect individual and group outcomes; (2) that indirect connections can be important (e.g., partners
of your partners matter); (3) that individuals differ in their importance in the social network (some can be considered keystone
individuals); and (4) that social network traits often carry over across contexts (e.g., SN position in male–male competition
can influence later male mating success). We then discuss how these four points, and the social network approach in general,
can yield new insights and questions for a broad range of issues in behavioral ecology including: mate choice, alternative
mating tactics, male–male competition, cooperation, reciprocal altruism, eavesdropping, kin selection, dominance hierarchies,
social learning, information flow, social foraging, and cooperative antipredator behavior. Finally, we suggest future directions
including: (1) integrating behavioral syndromes and SNT; (2) comparing space use and SNS; (3) adaptive partner choice and
SNS; (4) the dynamics and stability (or instability) of social networks, and (5) group selection shaping SNS.
This contribution is part of the special issue “Social networks: new perspectives” (Guest Editors: J. Krause, D. Lusseau and
R. James). 相似文献