Two linked probes were used to determine the Huntington's disease status of the fetus conceived by a woman affected with the condition. The fetus was found to be unaffected with a certainty of 97 per cent. The ethical issues associated with presymptomatic testing were avoided since the mother presented with initial symptoms of Huntington's disease, but other psychological and ethical issues arose. The concerns of an affected woman planning a pregnancy, and the dilemmas involved in decision-making regarding prenatal diagnosis and possible selective abortion were exposed and explored with the patient and her husband. 相似文献
Scientists in higher education institutions around the globe recognize the importance of engaging with public stakeholders to share their enthusiasm, explain their science, and encourage primary and secondary students to enter the sciences. However, without direct consideration of students’ and teachers’ perspectives and interests, scientists may design activities around their own goals, limiting the impact on school stakeholders (i.e., students, teachers, paraprofessional staff, students’ parents, and other caregivers). We drew from natural and social science research to describe how expanding the conception of place beyond the biophysical can help engage school stakeholders in meaningful ways. We describe the multidimensional PLACE framework that we developed to integrate perspectives, knowledge, and values of all stakeholders in engagement programming. The framework is organized around topics that stakeholders should discuss early on to ensure successful partnerships. We recommend that scientists identify and use pedagogy that is inclusive; language framed around dialogic communication methods; aims and motivations centered on engagement; cultural funds of knowledge of place (i.e., disciplinary, personal, or experiential knowledge); and evaluation of engagement based on meaningful metrics. Two case studies are presented to illustrate how the PLACE framework components, when addressed, can lead to robust, successful partnerships between scientists and schools. 相似文献
There is growing concern that recreational shoreline angling activity may negatively impact littoral and riparian habitats
independent of any direct or indirect influences of fish harvest or fishing mortality through mechanisms such as disturbance
(e.g., trampling, erosion) and pollution (e.g., littering). We sampled a suite of aquatic and terrestrial variables (i.e.,
water quality, aquatic and terrestrial macrophytes, soil compaction, anthropogenic refuse) at 14 high shoreline angling-activity
sites (identified by way of interviews with conservation officers and angling clubs) within an urban area (Ottawa, Canada).
For each high angling-activity site, a nearby corresponding low angling-activity site was sampled for comparison. We found
that the percentage of barren area and soil compaction were greater in areas of high angling activity compared with areas
that experienced relatively low angling activity. In addition, terrestrial and aquatic macrophyte density, height, and diversity
were lower at high angling-activity sites. Angling- and non-angling-related litter was present in large quantities at each
of the high angling-activity sites, and comparatively little litter was found at low angling-activity sites. Collectively,
these findings indicate that shoreline angling does alter the riparian environment, contributing to pollution and environmental
degradation in areas of high angling intensity. With growing interest in providing urban angling opportunities and in response
to increasing interest in developing protected areas and parks, a better understanding of the ecologic impacts of shoreline
angling is necessary to address multiuser conflicts, to develop angler outreach and educational materials, and to optimize
management of angling effort to maintain ecologic integrity of riparian and aquatic ecosystems. 相似文献
In the pipefish Syngnathus typhle, only males brood embryos in specially developed brood pouches, supplying oxygen and nutrients. Laboratory studies have shown that this elaborate paternal care has led to sex-role reversal in this species: males limit female reproductive rate, females are the primary competitors for mates and males exercise greater selectivity in accepting mates. In the first field study of this pipefish, we describe mating behaviour in the wild and test the hypothesis that temporal variations in the operational sex ratio (OSR) determine sex differences in mating behaviour. Our study comprised two reproductive seasons of two sequential mating periods each, the latter separated by a lengthy interval of male brooding. During mating periods, females displayed to all males without wandering and males moved about searching for females, without reacting to all females. The OSR was least female-biased (or even male-biased) at the onset of the breeding season, when most pipefish were simultaneously available to mate, but became strikingly female-biased as males' pouches were filled. The OSR remained substantially female-biased during the second mating period, because few males became available to remate at any one time. As hypothesised, female-biased OSRs resulted in more female-female meetings. As well, females were above the eelgrass more often than brooding males, thus exposing themselves to conspecifics and/ or predators. In the second year, males arrived earlier than females on the breeding site and male pregnancies were shorter, because of higher water temperatures, so rematings occurred earlier. Males met more often during that year than the previous one, but male competitive interactions were still not observed. The field results support laboratory studies and demonstrate that behaviours associated with female-female competition are more prominent when the OSR is more female-biased.
Correspondence to: A. Vincent 相似文献
Since it was commercially introduced in 1974, glyphosate has been one of the most commonly used herbicides in agriculture worldwide, and there is growing concern about its adverse effects on the environment. Assuming that glyphosate may increase the organic turbidity of water bodies, we evaluated the effect of a single application of 2.4?±?0.1 mg l?1 of glyphosate (technical grade) on freshwater bacterioplankton and phytoplankton (pico, micro, and nanophytoplankton) and on the physical and chemical properties of the water. We used outdoor experimental mesocosms under clear and oligotrophic (phytoplanktonic chlorophyll a?=?2.04 μg l?1; turbidity?=?2.0 NTU) and organic turbid and eutrophic (phytoplanktonic chlorophyll a?=?50.3 μg l?1; turbidity?=?16.0 NTU) scenarios. Samplings were conducted at the beginning of the experiment and at 1, 8, 19, and 33 days after glyphosate addition. For both typologies, the herbicide affected the abiotic water properties (with a marked increase in total phosphorus), but it did not affect the structure of micro and nanophytoplankton. In clear waters, glyphosate treatment induced a trend toward higher bacteria and picoeukaryotes abundances, while there was a 2 to 2.5-fold increase in picocyanobacteria number. In turbid waters, without picoeukaryotes at the beginning of the experiment, glyphosate decreased bacteria abundance but increased the number of picocyanobacteria, suggesting a direct favorable effect. Moreover, our results show that the impact of the herbicide was observed in microorganisms from both oligo and eutrophic conditions, indicating that the impact would be independent of the trophic status of the water body. 相似文献
Objective: The present study investigated the relationships between safety climate and driving behavior and crash involvement.
Methods: A total of 339 company-employed truck drivers completed a questionnaire that measured their perceptions of safety climate, crash record, speed choice, and aberrant driving behaviors (errors, lapses, and violations).
Results: Although there was no direct relationship between the drivers' perceptions of safety climate and crash involvement, safety climate was a significant predictor of engagement in risky driving behaviors, which were in turn predictive of crash involvement.
Conclusions: This research shows that safety climate may offer an important starting point for interventions aimed at reducing risky driving behavior and thus fewer vehicle collisions. 相似文献
In order for grain handlers and traders to reliably estimate residues of grain protectants in the field, antibody-based rapid tests were developed for carbaryl (1-naphthyl methylcarbamate) and methoprene [isopropyl (E,E)-(RS)-11-methoxy-3,7,11-trimethyldodeca-2,4-dienoate]. To complement the rapid analysis, a simple and rapid extraction technique was developed. In these tests, a pesticide-containing methanol extract of the grain sample and an enzyme-labeled component are added to precoated strips. After a brief incubation, the strips are washed and a substrate/chromogen for the enzyme is added. The color developed is stopped by acidification and the results are read either by eye or in a portable field photometer. The overall test time is under 20 minutes. For carbaryl, the test had a limit of detection of 4.5 ppb (1.1 ppm in grain), while the methoprene test had a limit of detection of 4 ppb (1 ppm in grain) based on the lower datum point, which is 15% inhibition, in the standard curves. Both assays can be used as a screening test for carbaryl and methoprene in animal feed grains. 相似文献
An animal can only survive in a given habitat if it has enough time to find, process and digest food whilst avoiding predation. The time it has for food acquisition is affected by the vegetation and competition with conspecifics, which depends on aggregation tendencies. We used the relationships between time allocations, on the one hand, and climatic variables (as a proxy for habitat quality) and group size, on the other, to develop a model that predicts maximum ecologically tolerable group size at different locations for spider monkeys. Spider monkeys are particularly interesting because the social communities often split up into small units. Temperature variation and rainfall variation were the main determinants of time budgets. Community size and average annual rainfall determined party size. The model correctly predicted presence or absence of spider monkeys at 78–83% of 217 New World forest sites. Within the geographical range of the species, this time budget model predicted the presence of spider monkeys better than a model based directly on climate variables. Predicted community and party sizes were significantly larger at sites where spider monkeys are present than at sites where they are absent. As required by the model, predicted maximum community sizes were significantly larger than observed community sizes. Moving time showed a U-shaped relationship with party size, which suggests that moving time is the factor that keeps spider monkey communities from travelling together in a tight group. 相似文献
Water is a salient issue in the Intermountain West of the United States (U.S.), with concerns ranging from water scarcity and drought to intermittent flooding and water quality risks. This paper investigates coverage of water issues across seven newspapers in the core of the U.S. Intermountain West region. Newspapers have the potential to set agendas and influence perceived salience of issues among consumers. The Intermountain West region shares common concerns about water supply and demand, climate change, and water quality. We investigate whether or not local daily newspaper coverage of water issues provides a more local or regional sensitivity. Findings from this exploratory study reveal differences in water coverage across local daily newspapers. The overall volume of water‐related articles differed across newspapers as did proportion of articles on specific water topics and connecting issues. Coverage of local issues was more dominant than might be expected given mass media trends, but water geography in articles extended across the U.S. and the world in every newspaper studied. Variations in newspaper coverage of water issues suggests more local nuance persists despite the experience of common water issues across the region. 相似文献