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181.
PROBLEM: There is limited information about how parents view teen driving risks and intend to handle these risks during the licensing process, and how they will respond to graduated licensing provisions. METHODS: Parents in Connecticut were interviewed when their teens got their learner's permit. The survey was undertaken when the state did not have a midnight restriction or a passenger restriction. RESULTS: Generally, parents were well aware of teen driving risks, thought parents should be thoroughly involved in the licensing process, and plan to be active participants themselves. DISCUSSION: Parents were concerned about the risk of driving after midnight and already restrict that behavior. However, parents do not seem to see or understand the risks of having even one teen passenger in the vehicle. IMPACT ON INDUSTRY: The views and existing practices of parents need to be taken into account in deciding on the provisions of graduated licensing legislation and how to best ensure acceptance and compliance. 相似文献
182.
Arsenate (As(V)) is a carcinogen and a significant problem in groundwater in many parts of the world. Since As(III) is generally more mobile and more toxic than As(V), the reduction of As(V) to As(III) is not a conventional treatment goal. However, reducing As(V) to As(III) may still be a means for decontamination, because As(III) can be removed from solution by precipitation or complexation with sulfide or by adsorption to Fe(II)-based solids. A promising approach for reducing oxidized contaminants is the H2-based membrane biofilm reactor (MBfR). In the case of arsenate, the MBfR allows bio-reduction of As(V) to As(III) and sulfate to sulfide, thereby giving the potential for As removal, such as by precipitation of As2S3(s) or formation of Fe(II)-based solids. When As(V) was added to a denitrifying MBfR, As(V) was reduced immediately to As(III). Decreasing the influent sulfate loading increased As(V) reduction for a fixed H2 pressure. A series of short-term experiments elaborated on how As(V) loading, nitrate and sulfate loadings, and H2 pressure controlled As(V) reduction. Lower nitrate loading and increased As(V) loading increased the extent of As(V) reduction, but increased H2 pressure did not increase As(V) reduction. As(V) reduction was sensitive to sulfate loading, with a maximum As(V)-removal percentage and flux with no addition of sulfate. As(III) could be precipitated with sulfide or adsorbed to Fe(II) solids, which was verified by scanning electron microscopy and energy dispersive X-ray analysis. 相似文献
183.
Polybrominated diphenyl ethers (PBDEs) are one class of flame retardants commonly used in textiles, foams and plastics. They are similar in behavior to the well-studied polychlorinated biphenyls and growing evidence suggests they are widespread global environmental pollutants that are capable of bioaccumulation. Fish tissue samples were collected from sites along the Penobscot River in central Maine. The total concentration of tetra- to hepta-PBDEs in these samples were calculated and generally increased from upstream to downstream locations ranging from 800 to 1810 ng/g lipid at the northernmost site to 5750-29000 ng/g at the downstream sampling site. BDE-47, 99 and 100 were the predominant congeners found in the fish tissue. Wastewater treatment plants (WWTPs) are one of the potential sources of these compounds to the environment through effluent discharge and landspreading of biosolids. Influent, effluent, activated sludge and dewatered biosolids were collected and analyzed for PBDE congeners from a WWTP at Orono, Maine. PBDE congeners were detectable in effluent samples at concentrations from 0.31 to 0.90 microg/l, in the activated sludge at 1.32-3.8 microg/l and in the influent at 4.2-4.3 microg/l, but the majority of the material was concentrated in the biosolids. Total concentration in the biosolids was 2320-3530 microg/kg dry weight. 相似文献
184.
Wu TH Cañas JE Rainwater TR Platt SG McMurry ST Anderson TA 《Environmental pollution (Barking, Essex : 1987)》2006,144(1):151-157
Seven complete clutches of Morelet's crocodile (Crocodylus moreletii) eggs were collected in northern Belize and examined for organochlorine (OC) pesticide residues. The primary OC detected, p,p-DDE, was found in every egg analyzed (n=175). Other OCs detected included p,p-DDT, p,p-DDD, methoxychlor, aldrin, and endosulfan I. Concentrations of individual OCs ranged from 4 ppb (ng chemical/g egg wet weight) to greater than 500 ppb. A statistical evaluation of p,p-DDE levels in three complete clutches was used to derive the minimum number of eggs needed from a clutch to precisely determine the mean p,p-DDE concentration representative of that clutch. Sample sizes of 8 (80% confidence level) and 11 (90% confidence level) were determined to yield an accurate estimate of contaminant levels in a full clutch of eggs. The statistically recommended sample size of 11 eggs (at 90% confidence level) was successfully tested on the four additional clutches. 相似文献
185.
Naumann RB Dellinger AM Anderson ML Bonomi AE Rivara FP 《Journal of Safety Research》2012,43(2):141-144
PurposeThis study compared the healthcare utilization and costs for specific types of medical services among older adult women who currently drive and those who no longer drive.MethodsThis study included 347 women aged 65 or older who were either former (had stopped driving) or current drivers, randomly sampled from a large U.S. health plan to participate in a telephone survey, and who had automated health records with healthcare utilization and cost data. Bivariate analyses and generalized linear modeling were used to examine associations between driving status and healthcare utilization and costs.ResultsAdjusting for age, income, and marital status, former drivers were more likely than current drivers to use mental health care services (RR = 3.37; 95% CI: 1.03, 10.98). Former drivers also tended to use more inpatient (RR = 1.85; 95% CI: 0.88, 3.87) and emergency services (RR = 1.89; 95% CI: 0.96, 3.70), but results did not reach statistical significance. Total annual healthcare costs in 2005 were almost twice as high for former drivers compared with current drivers ($13,046 vs. $7,054; mean difference = $5,992; 95% CI: -$360, $12,344), although this relationship was not statistically significant (CR = 1.61; 95% CI: 0.88, 2.96).Impact on IndustryFormer drivers were more than three times as likely as current drivers to use mental health services, and tended to use more emergency and inpatient services. Further research on factors that potentially mediate the relationship between driving status and health service use is warranted. 相似文献
186.
187.
Compensating for biodiversity losses in 1 location by conserving or restoring biodiversity elsewhere (i.e., biodiversity offsetting) is being used increasingly to compensate for biodiversity losses resulting from development. We considered whether a form of biodiversity offsetting, enhancement offsetting (i.e., enhancing the quality of degraded natural habitats through intensive ecological management), can realistically secure additional funding to control biological invaders at a scale and duration that results in enhanced biodiversity outcomes. We suggest that biodiversity offsetting has the potential to enhance biodiversity values through funding of invasive species control, but it needs to meet 7 key conditions: be technically possible to reduce invasive species to levels that enhance native biodiversity; be affordable; be sufficiently large to compensate for the impact; be adaptable to accommodate new strategic and tactical developments while not compromising biodiversity outcomes; acknowledge uncertainties associated with managing pests; be based on an explicit risk assessment that identifies the cost of not achieving target outcomes; and include financial mechanisms to provide for in‐perpetuity funding. The challenge then for conservation practitioners, advocates, and policy makers is to develop frameworks that allow for durable and effective partnerships with developers to realize the full potential of enhancement offsets, which will require a shift away from traditional preservation‐focused approaches to biodiversity management. El Potencial de la Compensación de la Biodiversidad para Financiar Controles Efectivos de Especies Invasoras 相似文献
188.
Javier Atalah Saskia A. Otto Marti J. Anderson Mark J. Costello Mark Lenz Martin Wahl 《Marine Biology》2007,153(2):199-211
Natural heterogeneity in ecological parameters, like population abundance, is more widely recognized and investigated than
variability in the processes that control these parameters. Experimental ecologists have focused mainly on the mean intensity
of predictor variables and have largely ignored the potential to manipulate variances in processes, which can be considered
explicitly in experimental designs to explore variation in causal mechanisms. In the present study, the effect of the temporal
variance of disturbance on the diversity of marine assemblages was tested in a field experiment replicated at two sites on
the northeast coast of New Zealand. Fouling communities grown on artificial settlement substrata experienced disturbance regimes
that differed in their inherent levels of temporal variability and timing of disturbance events, while disturbance intensity
was identical across all levels. Additionally, undisturbed assemblages were used as controls. After 150 days of experimental
duration, the assemblages were then compared with regard to their species richness, abundance and structure. The disturbance
effectively reduced the average total cover of the assemblages, but no consistent effect of variability in the disturbance
regime on the assemblages was detected. The results of this study were corroborated by the outcomes from simultaneous replicate
experiments carried out in each of eight different biogeographical regions around the world. 相似文献
189.
Adrianna P. Smyth Bruce K. Orr Robert C. Fleischer 《Behavioral ecology and sociobiology》1993,32(2):79-84
Summary The frequency of intraspecific brood parasitism in two colonies of cliff swallows (Hirundo pyrrhonota) nesting in the eastern Sierra Nevada in California was assessed through an electrophoretic analysis of egg white (albumin) proteins. Albumin proteins are maternally derived and are presumed to directly reflect maternal genotype. Thus, a comparison of protein banding patterns produced by eggs collected from a single clutch allows any egg laid by a female other than the putative mother to be detected. Eggs were collected from 13 cliff swallow nests in 1984 and 41 nests in 1987, a total of 54 nests. Of the clutches collected in 1984, one showed evidence of intraspecific brood parasitism, giving a nest parasitism rate of 7.6%. In 1987, one of 41 nests contained a parasitic egg, for a parasitism rate of 2.4%. Over both years combined the rate of intraspecific brood parasitism was 2 of 54 nests, or 3.7%. These parasitism rates are much lower than those estimated for Nebraskan cliff swallows (22–43%) and 2nd-year purple martins (36%). Possible explanations for the discrepancy between parasitism rates in Sierran cliff swallows and other groups of swallows are discussed.Correspondence to: A.P. Smyth 相似文献
190.
We used a combination of satellite telemetry, archival and conventional tags to show that white sharks made broad-scale movements consistent with mixing of the population across their entire Australasian range. The capture of one of these sharks in New Zealand, some 3,550 km from the point of tagging in South Australia, provides further confirmation that white sharks sometimes move into open ocean waters and cross deep ocean basins. However, most movements were confined to shelf waters, generally in areas of less than 100 m depth and in some cases into waters of less than 5 m depth. Sharks showed considerable plasticity in swimming patterns, which included many of the behaviours reported for other species. One of the archival-tagged sharks showed separate periods of distinct swimming behaviour as it moved into different habitats and travelled between them. The changes in swimming behaviour were abrupt and suggested rapid switching of hunting strategies for different prey types in these habitats. All tracked sharks showed both prolonged periods of directional swimming in coastal waters at swimming speeds of 2–3 km h−1 as well as temporary residency in particular regions. Movements of tagged white sharks, together with data from shark control programs and bycatch records, suggest a seasonal movement northward along the east coast of Australia during the autumn–winter months and south in spring–early summer. The consistency of paths taken by white sharks in Australian waters suggests that they may follow common routes or “highways” in some areas. If so, identifying such areas may assist in reducing interactions with fishing operations and thus reduce bycatch. 相似文献