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351.
The behavioral development of minor workers of the ant Pheidole dentata involves a progression of tasks beginning with brood care and culminating in foraging as individuals age. To understand the role of brain neurochemistry in age-related division of labor, we measured the levels of serotonin, dopamine and octopamine in individual brains of minor workers of different age. Serotonin and dopamine levels were significantly correlated with worker age: both increased as minor workers matured, and serotonin rose significantly in the oldest ants. In addition, the serotonin:dopamine ratio was significantly higher in the oldest workers. Octopamine levels did not change with age, although the ratios of octopamine:serotonin and octopamine:dopamine were significantly higher in the youngest workers. These age-associated changes in biogenic amine levels suggest an involvement of neuromodulators in minor worker behavioral ontogeny and temporal polyethism in P. dentata. 相似文献
352.
Background
The analysis of the intrinsic effects of perfluorinated organic surfactants shows the group to have a characteristic overall picture:Aim and Scope
The aim of the work was to analyse the intrinsic properties and risks of a subgroup of fluorinated organic substances.Results
A summarising article describes the toxic effects and properties of a group of substances selected from the approximately 30,000 existing substances. With regard to the ongoing debate on revising the European regulations of existing substances (REACH). it is apparent that standardised test requirements cannot be applied to impact and risk analyses which are at times highly complex. For governments, REACH only provides the starting points for this process in the form of prescribed standard tests. If a substance (or a substance group) draws attention, more detailed tests must be carried out by the industry itself in the framework of responsible care and in the framework of the evaluation step of REACH. It is therefore important that the standard requirements of REACH are selected appropriately. In this respect, the study reveals some serious deficiencies in the Commission proposal.Conclusion
The standard information for low tonnage substances (1–10 tonnes/a) must be supplemented in particular with an obligatory test on biodegradability. The possibility provided by the REACH dossier to evaluate substances on the basis of group observarions (SAR, QSAR e.g.) is to be welcomed. 相似文献353.
Barbara Skorupinski Heike Baranzke Hans Werner Ingensiep Marc Meinhardt 《Journal of Agricultural and Environmental Ethics》2007,20(1):37-52
This paper focuses on experiences from a case study dealing with the Swiss type of a consensus conference called “PubliForum”
concerning “Genetic Technology and Nutrition” (1999). Societal and ethical aspects of genetically modified food meanwhile
can be seen as prototypes of topics depending on the involvement of the public through a participatory process. The important
role of the lay perspective in this field seems to be accepted in practice. Nevertheless, there is still some theoretical
controversy about the necessity and democratic legitimacy of participatory processes in general, and especially about those
dealing with technological or environmental problems (sustainable development) concerning society. From an ethical point of
view, a lot of heterogeneous problems concerning contents and procedures of public participation can be pointed out, not only
on the theoretical level but also in practice, e.g., concerning the communication process between laypersons and experts.
The intention of our paper is to give hints and to clarify criteria that support the communication process leading to a dialog
of autonomous citizens and which especially consider ethical aspects in the field. One important result is that there must
be an orientation for all members of a consensus conference having clear rules and knowing their different roles that support
transparency, credibility, and fairness of the whole procedure and a “good product”: a substantial final document or citizens’
report.
This paper presents results of the project Ethical Bio-TA Tools as funded by the European Commission, DG Research, under FP5,
Quality of Life Programme. 相似文献
354.
Military and civilian aircraft overflights are an issue that may impact the quality of life for millions of United States residents. Aircraft noise annoys many people worldwide and is generally thought to adversely affect some wildlife species. In light of increasing demands being placed on airspace, and because of technological improvements in acoustical testing, there is a need to reexamine the effects of aircraft noise exposure on humans and wildlife. This paper reviews past research, current laws and legislation, and presents an argument for the need to revisit the effects of aircraft noise on humans and wildlife. Some evidence suggests that noise may adversely impact wildlife and humans, however, many of the past studies were inconclusive and based on relatively small sample sizes. Given that aircraft noise abatement legislation has been enacted and because of the recent promulgation of community-based noise awareness programs, future studies should be conducted to resolve public policy problems and debates associated with aircraft noise. The need to further study the effects of aircraft noise on humans and wildlife is critical for creating sustainable land use policies near aircraft installations. Data derived from these studies will be used to create sound public policies that enhance the operational capacity of military and civilian aircraft while reducing the opportunity for human and wildlife exposure to aircraft noise. 相似文献
355.
356.
Ecological impacts of water-quality problems have developed in the western United States resulting from the disposal of seleniferous
agricultural wastewater in wetland areas. Overt effects of selenium toxicosis occurred at five areas where deformities of
wild aquatic birds were similar to those first observed at Kesterson National Wildlife Refuge in the west-central San Joaquin
Valley of California. These areas are: Tulare Lake Bed Area, California, Middle Green River Basin, Utah, Kendrick Reclamation
Project Area, Wyoming, Sun River Basin, Montana, and Stillwater Wildlife Management Area, Nevada. Potential for ecological
damage is indicated at six more sites in Oregon, Colorado, the Colorado/Kansas border, and South Dakota out of 16 areas in
11 states where biological tissue data were collected. This conclusion is based on the fact that selenium bioaccumulated in
bird livers to median levels that had exceeded or were in the range associated with adverse reproductive effects. Selenium
concentrations in samples of fish and bird eggs support these conclusions at a majority of these areas. Reason for concern
is also given for the lower Colorado River Valley, although this is not exclusively a conclusion from these reconnaissance
data. Biogeochemical conditions and the extent of selenium contamination of water, bottom sediment, and biota from which this
assessment was made are given here. In a companion paper, the biogeochemical pathway postulated for selenium contamination
to take place from natural geologic sources to aquatic wildlife is defined. 相似文献
357.
358.
Françoise Muller Sophie Dreux Jean-François Oury Dominique Luton Serge Uzan Michèle Uzan Michel Levardon Marc Dommergues 《黑龙江环境通报》2002,22(11):1001-1004
Women having access to prenatal care late in pregnancy may still wish to benefit from maternal serum screening for Down syndrome. Therefore, we established reference values for α-feto protein (AFP) and free β-human chorionic gonadotrophin (β-hCG), and assessed the diagnostic value of maternal serum marker screening at 18–35 weeks' gestation based upon a series of 4072 sera from unaffected pregnancies and 118 sera from pregnant women with fetuses affected by Down syndrome. Using a 1/250 risk cut-off, a detection rate of 72.9% (95% CI = 71.5–74.3%) was achieved with a false-positive rate of 7.51% (95% CI = 6.71–8.3%). This was not significantly different from the percentages observed in our 14–17 weeks routine screening (50 596 patients): 71.9% (95% CI = 71.5–72.3%) and 6.48% (95% CI = 6.28–6.68%), respectively. Detection and screen-positive rates were, respectively, 51.3% (95% CI = 35.6–67.0%) and 5.95% (95% CI = 5.12–6.68%) in women aunder 35 years of age, and 84.8% (95% CI = 76.9–92.7%) and 24% (95% CI = 20.7–27.3%) in women aged 35 years and over. In conclusion, maternal serum marker screening is feasible at 18 weeks' gestation and later, which may be of interest in selected cases. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
359.
Arun S. Malik Bruce A. Larson Marc Ribaudo 《Journal of the American Water Resources Association》1994,30(3):471-480
ABSTRACT. The limited success of command-and-control policies for reducing nonpoint source (NPS) water pollution mandated under the Federal Water Pollution Control Act (FWPCA) has prompted increased interest in economic incentive policies as an alternative control mechanism. A variety of measures have been proposed ranging from fairly minor modifications of existing policies to substantial revisions including watershed-wide polices that rely on economic incentives. While greater use of economic incentive policies, such as environmental bonds and point/nonpoint source trading is being advocated in the reauthorization of the CWA, the expected effects of individual proposals will be modest. The characteristics of NPS pollution, namely uncertainty and asymmetrical information, underscores that there is no single, ideal policy instrument for controlling the many types of agricultural NPS water pollution. Some of the usual incentive-based policies, such as effluent taxes, are not well suited to the task. Individual incentive policies proposed for the reauthorized CWA, such as pollution trading or deposit/refund systems, are not broadly applicable for heterogeneous pollution situations. Economic incentive policies may be appropriate in some cases, and command-and-control policies will be preferable in others and may in fact complement incentive policies. 相似文献
360.
Michael J. Sebetich Vance C. Kennedy S. Marc Zand Ronald J. Avanzino Gary W. Zellweger 《Journal of the American Water Resources Association》1984,20(1):93-101
ABSTRACT: Injections of NO3 and PO4 were made during September 1975 into Little Lost Man Creek, a small pristine stream in Redwood National Park, California. Chloride, a conservative constituent, was added in a known ratio to the nutrients. Nutrient loss at a downstream point was calculated using concentration of added Cl as a reference. Nitrate nitrogen (NO3-N), added for 4 h, reached 920 μg/1 (above 5 μg/1 background) just below the injection point, but increased only to 405 μg/1 at 310 m downstream. The concentration decrease was attributed to dispersion and to uptake by stream biota. Percent of NO3-N lost decreased with increasing concentration of NO3-N. Phosphate phosphorus (PO4-P) was added a week after the NO3-N for 3 h, causing a concentration increase of 296 μg/1 (above 13 μg/1 background) just below the injection point, of 161 μg/1 at 90 m downstream, and of 98 μg/1 at 310 m. Percent loss of PO4-P at downstream sites increased with increasing PO4-P concentration and also for a short period after peak concentration occurred, but then decreased as PO4-P concentration continued decreasing. Differences in stream response to added NO3-N and PO4-P are attributed to differing rates of reaction with biota and differing degrees of interaction with abiotic stream solids. 相似文献