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221.
222.
Objective: The objective of this study was to identify, critically appraise, summarize, and synthesize evidence from cost-effectiveness analyses (CEAs) of interventions aimed at preventing road traffic injuries (RTIs) in low- and middle-income countries (LMICs) by age group and road users targeted.

Methods: A search strategy was applied to 12 electronic databases for studies published between May 2002 and August 2015 that met prespecified inclusion criteria. Additional studies were identified by contacting authors and searching bibliographies. Included studies were critically appraised against published criteria and a narrative synthesis was conducted including a use of the strength of evidence criteria.

Results: Five studies were included in the final review that reported 9 interventions. Only 2 out of 9 interventions (drink-drive legislation with enforcement via breath testing campaign and combined interventions for reducing RTIs) showed moderate evidence of being cost-effective, whereas the evidence of cost-effectiveness of other interventions was weak. Only 2 interventions (bicycle and motorcycle helmet use legislation and enforcement) were explicitly targeted to children, young people and vulnerable road users such as pedestrians and cyclists. The cost-effectiveness of interventions to prevent RTIs in LMICs ranged from US$4.14 per disability-adjusted life years (DALYs) averted for building speed bumps at the most dangerous junctions that caused 10% of junction deaths in the area studied to US$3,403 per DALYs averted for legislation and enforcement of helmet use by motorcyclists in the World Health Organization (WHO) sub-Saharan Africa region.

Conclusions: Evidence of cost-effectiveness of interventions to prevent RTIs in LMICs is limited, particularly for children, young people, and vulnerable road users. Evaluation of the effectiveness and cost-effectiveness of a larger number of possible road safety interventions in a variety of LMIC settings is warranted to generate the evidence base for effective traffic injury prevention programs.  相似文献   

223.
2267 singleton fetuses who had one ultrasound examination between 15 and 21 weeks' gestation were prospectively evaluated for echogenic small bowel. Thirty-two cases of echogenic small bowel were detected—a prevalence of 1·4 per cent. Echogenic fetal small bowel was divided into two grades: grade 1, where the small bowel was more echogenic than the liver; and grade 2, where the small bowel had the echogenicity of bone. In contrast to 19/23 fetuses with grade 1 small bowel echogenicity, only 2/9 fetuses with grade 2 echogenic bowel had a normal pregnancy outcome (Fisher's exact test; P⩽0·01). Complications associated with second-trimester echogenic small bowel included in utero cytomegalovirus infection, second-trimester growth restriction, intrauterine fetal demise, and chromosomal abnormalities. Second-trimester fetal echogenic small bowel is associated with an increased risk of an adverse outcome. The prevalence of perinatal and neonatal complications is significantly greater when small bowel echogenicity approaches that of bone.  相似文献   
224.
Although prominent fetal nuchal folds, short long bones, echogenic bowel, and renal pelviectasis have been shown to be associated with trisomy 21, none has acceptable diagnostic efficacy. Diminished fetal ear lengths measured by ultrasound have recently been reported as yet another potential morphological marker for the prenatal detection of trisomy 21. To investigate this further, we measured ear lengths and widths of normal (n = 107) and trisomy 21 (n = 25) second-trimester formalin-preserved fetuses. The normal ear growth characteristics are described and compared with those of trisomy 21 fetuses. The normal fetal ear shape, not unlike that of the neonates, manifested a marked variation. When the ear lengths and widths were regressed against gestational age, the slopes of the regression lines for the two groups were found to be different (P < 0·001). However, despite the statistically significant difference between the ear sizes of normal and trisomy 21 fetuses, the wide range of normal variation seen at each gestational age means that the fetal ear measurements are not diagnostically helpful.  相似文献   
225.
A methodology is described that allows determination of instream flow requirements for maintenance of riparian trees. Tree-ring data revealed strong relationships between tree growth and stream flow volume for riparian species at Rush Creek, an alluvial stream within an arid setting; these relationships allowed development of models that predict growth rates from hydrologic variables. The models can be used to assess instream flow requirements under the assumption that certain levels of growth are necessary to maintain the population. There is a critical need for development and use of instream flow methodologies for riparian vegetation, since present methodologies focus on needs of aquatic animals (e.g., fish) and may underestimate needs of the entire riparian ecosystem.  相似文献   
226.
Polychlorinated biphenyls (PCBs) are of environmental concern due to their toxic nature. Ionizing radiation has been suggested as a means to remediate PCB-contaminated samples in complex matrices. A set of experiments was performed to qualitatively and quantitatively determine the aromatic degradation products of 2-monochlorobiphenyl (2-MCB) in an aqueous system exposed to ionizing radiation. The degradation of 2-MCB was observed in aqueous samples that were exposed to radiation from a linear accelerator electron beam source. Analytical measurements performed by liquid chromatography (LC) equipped with an ultraviolet (UV) detector revealed that biphenyl, o-hydroxybiphenyl, p-hydroxybiphenyl, phenol, chlorobenzene, and other unidentified products were created after 2-MCB irradiation. These results suggest that sensitive and selective analytical methods will be required to account for all degradation products during ionizing radiation of aqueous PCB-contaminated samples.  相似文献   
227.
Indoor air pollutant concentrations can be influenced by how rapidly species are transported to and from surfaces. Consequently, a greater understanding of indoor transport phenomena to surfaces improves estimates of human exposure to indoor air pollutants. Here, we introduce two methods of rapidly and directly measuring species fluxes at indoor surfaces, allowing us to evaluate the transport-limited deposition velocity, vt (a mass-transfer coefficient). The deposition velocity sensor (DeVS) method employs a small microbalance coated with a pure hydrocarbon, preferably octadecane. We quantify flux (or evaporation rate) of the hydrocarbon into a room by observing the rate of mass loss on the microbalance. The transport-limited deposition velocity, vt,octadecane, is then obtained by combining the flux with the vapor pressure of the hydrocarbon. Simultaneously, vt,ozone is quantified using the deposition velocity of ozone (DeVO) method, which acts as a standard to calibrate and evaluate DeVS. Specifically, DeVO evaluates ozone transport to surfaces by quantifying the conversion by ozone of nitrite to nitrate on a glass fiber filter. Simultaneous laboratory chamber experiments demonstrates that vt for octadecane and ozone are strongly correlated, with the values for ozone 1.5 times greater than that for octadecane. In an office experiments, the DeVS method responds within minutes to step changes in conditions such as occupancy, activities and ventilation. At present, the results are in order-of-magnitude agreement with predicted indoor mass-transfer coefficients.  相似文献   
228.
Summary Interactions in which one animal takes over a food resource from another (feeding supplants) are usually interpreted as evidence of feeding competition, and the level of competition is predicted to be proportionate to the value of the resource. However, in this study of juvenile olive baboons (Papio anubis) living in a troop near Gilgil, Kenya, individuals were less selective about the quality of the supplant food under certain social circumstances. Two major food classes, Grass and Corm, were compared. Corms were less common in the diet, more difficult to locate as a replacement food after a supplant, and then at greater distances than Grass: in general, corms were the favoured supplant food, as predicted. But in interactions between animals who were close in rank, supplants over Grass occurred more often than expected. It is suggested here that, in these particular interactions, the winner benefitted socially, even at some cost of time or energy. Further, such interactions which may serve to reinforce the winner's status will be most productively directed to those close in rank, where relationships are potentially less stable. These data provide evidence that baboons can discriminate the relative ranks of others, rather than simply distinguishing between individuals who are higher- or lower-ranking than themselves.  相似文献   
229.
The orientation of two closely related subspecies of Australian silvereye Zosterops lateralis was studied in captivity over 14 months. Migratory silvereyes Z. lateralis lateralis showed significant directional preferences during the spring and autumn migration periods and also displayed orientated behaviour during the breeding period. In contrast, the non-migratory subspecies Z. lateralis familiaris did not display any significant directional preferences at any time. This is the first time that the orientation behaviour of a migratory and non-migratory subspecies has been compared over the duration of an annual cycle, both during and outside the migratory periods. The results suggest that migratory silvereyes possess an endogenous program determining the timing and direction of autumn and spring migration and that this program is unique to the migratory subspecies. This is also the first comparison of this nature on southern hemisphere birds and demonstrates that the migratory behaviour of southern hemisphere migrants may be more similar to that of northern hemisphere migrants than previously thought.Submitted to Behavioral Ecology and Sociobiology: 23 Jan 2006.  相似文献   
230.
Solubilities of several hydrophobic organic substances (paradichlorobenzene, endrin, naphthalene, and dibutyl phthalate) in aqueous solutions containing up to 0.10 mole fraction of common alcohols and ketones, were measured by gas chromatography. The solubilities are significantly increased by the alcohols and ketones. The results are interpreted in terms of the association of n molecules of alcohol or ketone with each hydrophobic organic molecule. Values of n and the equilibrium constant for this association are reported for each hydrophobic organic-alcohol and organic-ketone combination. The implications of these results for the disposal of toxic wastes by landfilling is discussed.  相似文献   
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