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521.
Every year, more than 50,000 wildland fires affect about 500,000 ha of vegetation in southern European countries, particularly in wildland-urban interfaces (WUI). This paper presents a method to characterize and map WUIs at large scales and over large areas for wildland fire prevention in the South of France. Based on the combination of four types of building configuration and three classes of vegetation structure, 12 interface types were classified. Through spatial analysis, fire ignition density and burned area ratio were linked with the different types of WUI. Among WUI types, isolated WUIs with the lowest housing density represent the highest level of fire risk.  相似文献   
522.
In males, the acquisition and development of behavioral and morphological secondary sexual traits typically depends on testosterone and correlates with mating success. Testosterone level could affect competition for mates and thus be a target of sexual selection. We sought to relate testosterone levels to male mating competitiveness, by teasing apart the relationships between testosterone, behavior, and growth before the mating period. We monitored 24 adult bighorn rams (Ovis canadensis) at Ram Mountain, Alberta, from 2008 to 2011. Using linear mixed models, we tested the relationships between testosterone metabolites in feces, social rank, and both growth and size of two sexually selected traits: horns and body mass. The correlation between testosterone and social rank varied with age. Testosterone and rank were weakly and negatively correlated for young rams, positively correlated for prime-aged rams, and negatively correlated for older rams. Although testosterone had an increasingly positive effect on total horn length until 8 years of age, we could not detect any effects on annual growth rate of horns or body mass. Testosterone may be related to male’s ability to compete for mates through its relationship with behaviors determining social rank, rather than by influencing the development of morphological traits. Differences in testosterone levels among competitors may be a proximate cause of variance in fitness.  相似文献   
523.
The determination of the risk from flooding that shorefront communities face is an important component of coastal management that has not been resolved successfully. Wave runup offers one way of quantifying the risk of coastal flooding that results from overtopping by storm waves. The calculation of runup probabilities uses wave frequency analysis and an average beach/dune profile for a given shoreline segment. The amount of risk is determined by using a runup probability curve for specific shoreline locations within the segment. The procedure is demonstrated using the New Jersey shoreline as an example, and results indicate a higher degree of risk in the southern part of the state. Although the procedure is attractive, there is a need for additional field research to test: (1) the accuracy of the calculation procedure; (2) the applicability of a design profile for a shoreline segment; and (3) whether a non-storm beach/dune profile may be used in the calculation. In terms of the broader subject of coastal hazards, these runup calculations need to be integrated with research on beach erosion to provide a comprehensive assessment of the risk at specific locations.  相似文献   
524.
Ultrafine particles represent a growing concern in the public health community but their precise role in many illnesses is still unknown. This lack of knowledge is related to the experimental difficulty in linking their biological effects to their multiple properties, which are important determinants of toxicity. Our aim is to propose an interdisciplinary approach to study fine(FP) and ultrafine(UFP) particles, generated in a controlled manner using a mini CAST(Combustion Aerosol Standard) soot ...  相似文献   
525.
Exhaled ammonia (NH3ex) was measured by chemiluminescence in a group of healthy children (n = 20) and in two groups of asthmatic children, one (Group 1) residing in a National Park in the mountains (n = 68) and other (Group 2) in an urban area (n = 52). We also determined urinary ammonia, nitrates, urea, sodium and potassium normalized to osmolarity. Unlike exhaled nitric oxide (NOex), NH3ex was not specific to asthma as the children in Group 2 and the controls exhaled more ammonia that did the children in Group 1 (14.3 +/- 10.2 and 14.8 +/- 10.3 vs. 5.6 +/- 4.7 ppb; P < .001, respectively). In the urban environment, all children, including the healthy controls, excreted more ammonia (P < .001) and potassium (P < .001) but less urea (P < .02) than did the children residing in the National Park. These manifestations of moderate metabolic acidosis would favor excretion of ammonia at the expense of urea. In the children residing in the National Park, positive correlations were observed between NH3ex and urinary ammonia, and nitrates, age and morphological parameters. The relationship with the morphological parameters is a reflection of the normal physiological formation of NH3ex. In the children residing in the urban area, the other endogenous source of NH3ex was attributed to a slight disturbance in acid-base balance. In conclusion, the measurement of NH3ex appeared of limited interest, although the higher urinary urea/NH4+ ratio in Group 1 (P < .0001), especially in the treated children, appeared to be linked to the lack of atmospheric pollutants in the National Park. Further experimentation is in progress to confirm these findings.  相似文献   
526.
Cinosulfuron (3-(4,6-dimethoxy-1,3,5-triazin-2-yl)-1-[2-(2-methoxyethoxy)-phenylsulfonyl]-urea) is a sulfonylurea herbicide used to control a wide range of broadleaf weeds in rice (Oryza sativa L.). A 2-yr field study was conducted in northwest Italy to determine the effect of cinosulfuron on surface and subsoil waters in rice paddies. Cinosulfuron was applied at 70 g a.i. ha(-1) on 35 ha of flooded rice. After the treatment, the change in herbicide concentration over time was studied by analyzing water and sediment samples in a test paddy field (2.16 ha, located in the treated area), water in a spring and a pond (both located near the test paddy), two wells (up- and downhill to the treated area), and two piezometers (along the test paddy levee). To better understand some of the field study results, cinosulfuron degradation was also evaluated in the laboratory in solutions buffered to different pH values. Two weeks after the treatment, the cinosulfuron concentration in the paddy water decreased by about 60%. No cinosulfuron was detected at about 2.5 mo after the treatment. The concentration in the sediment gradually increased after the treatment, reaching the highest value (13.53 microg kg(-1)) 3 wk later. The maximum cinosulfuron content in the spring and pond were 0.91 and 0.29 microg L(-1), respectively, and these were detected 60 to 90 days after treatment (DAT). The water collected in the piezometers reached the highest concentration (0.99 microg L(-1)) 29 DAT. Cinosulfuron was never detected in the wells. In the degradation study at different pH values, cinosulfuron degraded rapidly at low pH values.  相似文献   
527.
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   
528.
The improved in vitro bioremediation of Arabian Light crude oil in synthetic sea water by a mixed culture of bacteria is reported. Effects of fish meal, meat meal 80 % proteins and sophorolipids on the biodegradation were evaluated during a three-week incubation using GC/FID and GC/MS analysis of the remaining oil. Fish meal and more particularly meat meal 80 % proteins used at 0,5 mg.ml−1 involve no nitrogen and phosphorous limits when used as sole source of nutrients. Biodegradation processes in the first four days of the incubation supplemented with sophrolipids are accelerated two fold over controls.  相似文献   
529.
For landslide susceptibility mapping, this study applied and verified a Bayesian probability model, a likelihood ratio and statistical model, and logistic regression to Janghung, Korea, using a Geographic Information System (GIS). Landslide locations were identified in the study area from interpretation of IRS satellite imagery and field surveys; and a spatial database was constructed from topographic maps, soil type, forest cover, geology and land cover. The factors that influence landslide occurrence, such as slope gradient, slope aspect, and curvature of topography, were calculated from the topographic database. Soil texture, material, drainage, and effective depth were extracted from the soil database, while forest type, diameter, and density were extracted from the forest database. Land cover was classified from Landsat TM satellite imagery using unsupervised classification. The likelihood ratio and logistic regression coefficient were overlaid to determine each factors rating for landslide susceptibility mapping. Then the landslide susceptibility map was verified and compared with known landslide locations. The logistic regression model had higher prediction accuracy than the likelihood ratio model. The method can be used to reduce hazards associated with landslides and to land cover planning. Note: This version was published online in June 2005 with the cover date of August 2004.  相似文献   
530.
We evaluated mitochondrial DNA (mtDNA) sequence variation in a 910 bp region of the cytochrome b gene of the storm petrel, Hydrobates pelagicus. Samples from birds collected from five populations in the North Atlantic Ocean and the Mediterranean Sea were investigated. Genetic differentiation within the Mediterranean basin was low but high in the Atlantic. Strong differences were noted between the Atlantic and the Mediterranean populations, confirming the distinction of the subspecies H. p. pelagicus and H. p. melitensis for the Atlantic and Mediterranean seabirds, respectively. Divergence between the two subspecies probably resulted from paleogeographic changes in the Strait of Gibraltar, which was likely the route used by H. pelagicus to invade the Mediterranean Sea. Current and past demography and ecology of the storm petrel is regarded as an explanation for the level of differentiation observed within each oceanic basin. We compare the phylogeographic pattern of the storm petrel to other seabirds that breed in the same regions.Communicated by S. A. Poulet, RoscoffC.C. and L.B. contributed equally to this paper.  相似文献   
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