共查询到20条相似文献,搜索用时 0 毫秒
1.
Wei‐Qiang Chen 《Journal of Industrial Ecology》2013,17(6):926-938
Recycling rates of aluminum are defined in different (sometimes inconsistent) ways and poorly quantified. To address this situation, the definitions and calculation methods of four groups of indicators are specified for the United States: (1) indicators used to measure recycling efficiencies of old aluminum scrap at the end‐of‐life (EOL) stage, including EOL collection rate (CR), EOL processing rate, EOL recycling rate, and EOL domestic recycling rate; (2) indicators used to compare generation or use of new with old scrap, including new to old scrap ratio, new scrap ratio (NSR), and old scrap ratio; (3) indicators used to compare production or use of primary aluminum with secondary aluminum, including four recycling input rates (RIRs); and (4) indicators used to track the sinks of aluminum metal in the U.S. anthroposphere. I find that the central estimate of EOL CR varies between 38% and 65% in the United States from 1980 to 2009 and shares a relatively similar historical trend with the primary aluminum price. The RIR is shown to be significantly reduced if excluding secondary aluminum produced from new scrap resulting from the relatively high NSR. In 2003, a time when approximately 73% of all of the aluminum produced globally since 1950 was considered to still be “in service,” approximately 68% to 69% of all metallic aluminum that had entered the U.S. anthroposphere since 1900 was still in use: 67% in domestic in‐use stock and 1% to 2% exported as scrap. Only 6% to 7% was definitely lost to the environment, although the destination of 25% of the aluminum was unknown. It was either exported as EOL products, was currently hibernating, or was lost during collection. 相似文献
2.
Jacqueline Moya 《人类与生态风险评估》2004,10(6):1195-1211
Contaminants that accumulate in fish may pose health risks and have raised concerns among consumers. Contaminated finfish and shellfish are possible routes of human exposure to toxic chemicals. Fish advisories are established to protect local populations from the consumption of contaminated commercial and non-commercially caught fish. Children, women of childbearing age, and subsistence fishermen or other highly exposed individuals who for socioeconomic or cultural reasons consume more fish than the general population are among the populations of concern from the ingestion of contaminated fish. Estimating exposure to a toxic chemical among fish-consuming populations requires knowledge about intake rates of fish and shellfish. Data on fish consumption rates come from various sources, including national, state, and local government studies. Although these data have their limitations, they serve as a source for deriving fish consumption rates that may be used by exposure assessors. Data on specific populations of concern are critical. Studies presented here show that ethnicity, age, and geographical region play an important role in fishing behavior and consumption. Results from studies on Native American populations show that this ethnic group eats fish at a higher rate than recreational anglers. This article summarizes data on fish consumption for various populations and provides a framework for evaluating data from these studies for exposure assessment applications. 相似文献
3.
Century-Scale Responses of Ecosystem Carbon Storage and Flux to Multiple Environmental Changes in the Southern United States 总被引:2,自引:0,他引:2
Hanqin Tian Guangsheng Chen Chi Zhang Mingliang Liu Ge Sun Arthur Chappelka Wei Ren Xiaofeng Xu Chaoqun Lu Shufen Pan Hua Chen Dafeng Hui Steven McNulty Graeme Lockaby Eric Vance 《Ecosystems》2012,15(4):674-694
Terrestrial ecosystems in the southern United States (SUS) have experienced a complex set of changes in climate, atmospheric CO2 concentration, tropospheric ozone (O3), nitrogen (N) deposition, and land-use and land-cover change (LULCC) during the past century. Although each of these factors has received attention for its alterations on ecosystem carbon (C) dynamics, their combined effects and relative contributions are still not well understood. By using the Dynamic Land Ecosystem Model (DLEM) in combination with spatially explicit, long-term historical data series on multiple environmental factors, we examined the century-scale responses of ecosystem C storage and flux to multiple environmental changes in the SUS. The results indicated that multiple environmental changes shifted SUS ecosystems from a C source of 1.20?±?0.56?Pg (1?Pg?=?1015?g) during the period 1895 to 1950, to a C sink of 2.00?±?0.94?Pg during the period 1951 to 2007. Over the entire period spanning 1895–2007, SUS ecosystems were a net C sink of 0.80?±?0.38?Pg. The C sink was primarily due to an increase in the vegetation C pool, whereas the soil C pool decreased during the study period. The spatiotemporal changes of C storage were caused by changes in multiple environmental factors. Among the five factors examined (climate, LULCC, N deposition, atmospheric CO2, and tropospheric O3), elevated atmospheric CO2 concentration was the largest contributor to C sequestration, followed by N deposition. LULCC, climate, and tropospheric O3 concentration contributed to C losses during the study period. The SUS ecosystem C sink was largely the result of interactive effects among multiple environmental factors, particularly atmospheric N input and atmospheric CO2. 相似文献
4.
ROBERT N. LEHMAN JULIE A. SAVIDGE PATRICIA L. KENNEDY RICHARD E. HARNESS 《The Journal of wildlife management》2010,74(3):459-470
ABSTRACT We estimated electrocution rates for raptors and common ravens (Corvus corax) for the Moon Lake Electrical Association in northeastern Utah and northwestern Colorado, USA. From July 2001 to May 2003, we conducted mortality searches at randomly selected distribution line segments and poles within 3 regions, but rate estimates (0.0036–0.0112 deaths/pole/yr) may have been biased by the effects of scavengers and by long sampling intervals (≥ 3 months), which prevented us from determining the cause of death for most birds because of advanced decay. In 2002–2003, we conducted carcass removal experiments in the Rangely Oil Field (ROF) in northwestern Colorado to estimate scavenging effects, and in 2003–2004, we reduced sampling intervals to 1 month and searched for dead birds at all distribution poles in the ROF. The shorter sampling interval nearly tripled the number of birds suitable for necropsy, but we were still unable to establish cause of death for >40% of our sample. Instead of eliminating the unknowns from rate estimates, we estimated minimum annual electrocution rates using only confirmed electrocutions and maximum annual electrocution rates based on all available mortalities, including mortalities without known causes. Golden eagles (Aquila chrysaetos) accounted for 63% of dead birds found in 2003–2004, but they were removed by scavengers at rates well below hawks and owls (6.8% vs. 55.6%). We compared maximum rates for the ROF in 2003–2004 with the rates estimated from a survey conducted at the same poles in 1999 to assess the effects of retrofitting conducted by Moon Lake from 1999 to 2003. Electrocution rates in 2003–2004 were 47% lower than those in 1999. Raptor densities in the ROF did not change during our study, suggesting the reduction was not the result of changes in raptor populations. However, estimates of raptor densities in 1999 were not available, and we cannot be sure that numbers of birds using the oil field in 1999 were similar to those in 2003–2004. Our research emphasizes the difficulties of estimating electrocution rates precisely but suggests that utilities will have the greatest effect on mortality by monitoring power lines at large scales and focusing subsequent mitigation efforts in areas that pose the greatest risk to the greatest number of birds. 相似文献
5.
Kenneth J. Mukamal Christina C. Wee Matthew Miller 《Obesity (Silver Spring, Md.)》2009,17(10):1946-1950
BMI has been inversely associated with risk of completed suicide in several cohort studies, but putative mechanisms for this association and its generalizability throughout the United States are uncertain. We ascertained recent population‐based, state‐level data on rates of obesity, completed suicide (by method), firearm ownership, smoking, major depression, income, education, white race, and nonmetropolitan residence, compiled from federal agencies and surveys, and determined the adjusted population‐weighted correlations of statewide obesity rates with measures of completed and attempted suicide. Statewide prevalence of obesity was strongly inversely correlated with age adjusted suicide rate (multivariable‐adjusted r = ?0.66; P < 0.001). The correlation was somewhat stronger for rates of nonfirearm‐related (r = ?0.75; P < 0.001) than firearm‐related suicides (r = ?0.53; P < 0.001), and was of similar magnitude as the positive correlations of firearm prevalence with suicide rate (r = 0.75; P < 0.001) or of obesity with prevalence of diabetes (r = 0.41; P = 0.006). In analyses of fatal and nonfatal suicidal acts, obesity rates were inversely correlated with rates of suicidal acts using firearms (r = ?0.53; P = 0.02) and suffocation (r = ?0.76; P < 0.001) but not other methods. Obesity rates were also inversely correlated with the case–fatality ratios of acts using poisoning (r = ?0.51; P = 0.01). Thus, statewide rates of obesity are strongly inversely correlated with rates of completed suicide in multivariable analyses, a finding that appears to relate to fewer attempts by suffocation and a lower case–fatality ratio for poisonings, although the mechanism for the inverse correlation with firearm‐related suicides requires further elucidation. 相似文献
6.
7.
We examine secular change in long bone lengths and allometry of Americans dating from the mid-19th century to the 1970s. Skeletal samples were derived from the Huntington Collection, Terry Collection, World War II casualties, and the Forensic Anthropology Data Bank. Regression of bone length on year of birth allowed evaluation of the secular change in bone length. Size was computed as the geometric mean of all bone lengths, and shape as the ratio of each bone to size. These variables were then regressed on year of birth, allowing evaluation of allometric secular change. The results revealed a pattern of change that can be summarized as follows: male secular change is stronger than female, lower limb bone secular change is more pronounced than upper limb bone change, and distal bones change more than proximal bones, particularly in the lower limb. In males, white changes are uniformly higher than black but these differences do not rise to the level of statistical significance. Environmental forces, such as nutrition and disease, are the usual causes of secular changes in overall size. This paper shows that long bone proportions also respond to these same environmental factors. Moreover, the changes in body proportion are likely to be due to allometric consequences of growth changes that occur early in life. Am J Phys Anthropol 110:57-67, 1999. 相似文献
8.
Background
Encephalitis rates by etiology and acute-phase outcomes for encephalitis in the 21st century are largely unknown. We sought to evaluate cause-specific rates of encephalitis hospitalizations and predictors of inpatient mortality in the United States.Methods
Using the Nationwide Inpatient Sample (NIS) from 2000 to 2010, a retrospective observational study of 238,567 patients (mean [SD] age, 44.8 [24.0] years) hospitalized within non-federal, acute care hospitals in the U.S. with a diagnosis of encephalitis was conducted. Hospitalization rates were calculated using population-level estimates of disease from the NIS and population estimates from the United States Census Bureau. Adjusted odds of mortality were calculated for patients included in the study.Results
In the U.S. from 2000–2010, there were 7.3±0.2 encephalitis hospitalizations per 100,000 population (95% CI: 7.1–7.6). Encephalitis hospitalization rates were highest among females (7.6±0.2 per 100,000) and those <1 year and >65 years of age with rates of 13.5±0.9 and 14.1±0.4 per 100,000, respectively. Etiology was unknown for approximately 50% of cases. Among patients with identified etiology, viral causes were most common (48.2%), followed by Other Specified causes (32.5%), which included predominantly autoimmune conditions. The most common infectious agents were herpes simplex virus, toxoplasma, and West Nile virus. Comorbid HIV infection was present in 7.7% of hospitalizations. Average length of stay was 11.2 days with mortality of 5.6%. In regression analysis, patients with comorbid HIV/AIDS or cancer had increased odds of mortality (odds ratio [OR] = 1.70; 95% CI: 1.30–2.22 and OR = 2.26; 95% CI: 1.88–2.71, respectively). Enteroviral, postinfectious, toxic, and Other Specified causes were associated with lower odds vs. herpes simplex encephalitis.Conclusions
While encephalitis and encephalitis-related mortality impose a considerable burden in the U.S. in the 21st Century, the reported demographics of hospitalized encephalitis patients may be changing. 相似文献9.
Douglas S. Goodin Michael Corwin David Kaufman Howard Golub Shoshana Reshef Mark J. Rametta Volker Knappertz Gary Cutter Dirk Pleimes 《PloS one》2014,9(8)
Background
Information on causes of death (CODs) for patients with multiple sclerosis (MS) in the United States is sparse and limited by standard categorizations of underlying and immediate CODs on death certificates. Prior research indicated that excess mortality among MS patients was largely due to greater mortality from infectious, cardiovascular, or pulmonary causes.Objective
To analyze disease categories in order to gain insight to pathways, which lead directly to death in MS patients.Methods
Commercially insured MS patients enrolled in the OptumInsight Research database between 1996 and 2009 were matched to non-MS comparators on age/residence at index year and sex. The cause most-directly leading to death from the death certificate, referred to as the “principal” COD, was determined using an algorithm to minimize the selection of either MS or cardiac/pulmonary arrest as the COD. Principal CODs were categorized into MS, cancer, cardiovascular, infectious, suicide, accidental, pulmonary, other, or unknown. Infectious, cardiovascular, and pulmonary CODs were further subcategorized.Results
30,402 MS patients were matched to 89,818 controls, with mortality rates of 899 and 446 deaths/100,000 person-years, respectively. Excluding MS, differences in mortality rate between MS patients and non-MS comparators were largely attributable to infections, cardiovascular causes, and pulmonary problems. Of the 95 excessive deaths (per 100,000 person-years) related to infectious causes, 41 (43.2%) were due to pulmonary infections and 45 (47.4%) were attributed to sepsis. Of the 46 excessive deaths (per 100,000 person-years) related to pulmonary causes, 27 (58.7%) were due to aspiration. No single diagnostic entity predominated for the 60 excessive deaths (per 100,000 person-years) attributable to cardiac CODs.Conclusions
The principal COD algorithm improved on other methods of determining COD in MS patients from death certificates. A greater awareness of the common CODs in MS patients will allow physicians to anticipate potential problems and, thereby, improve the care that they provide. 相似文献10.
Genetic Variation of Sclerotinia sclerotiorum from Multiple Crops in the North Central United States
Sclerotinia sclerotiorum is an important pathogen of numerous crops in the North Central region of the United States. The objective of this study was to examine the genetic diversity of 145 isolates of the pathogen from multiple hosts in the region. Mycelial compatibility groups (MCG) and microsatellite haplotypes were determined and analyzed for standard estimates of population genetic diversity and the importance of host and distance for genetic variation was examined. MCG tests indicated there were 49 different MCGs in the population and 52 unique microsatellite haplotypes were identified. There was an association between MCG and haplotype such that isolates belonging to the same MCG either shared identical haplotypes or differed at no more than 2 of the 12 polymorphic loci. For the majority of isolates, there was a one-to-one correspondence between MCG and haplotype. Eleven MCGs shared haplotypes. A single haplotype was found to be prevalent throughout the region. The majority of genetic variation in the isolate collection was found within rather than among host crops, suggesting little genetic divergence of S. sclerotiorum among hosts. There was only weak evidence of isolation by distance. Pairwise population comparisons among isolates from canola, dry bean, soybean and sunflower suggested that gene flow between host-populations is more common for some crops than others. Analysis of linkage disequilibrium in the isolates from the four major crops indicated primarily clonal reproduction, but also evidence of genetic recombination for isolates from canola and sunflower. Accordingly, genetic diversity was highest for populations from canola and sunflower. Distribution of microsatellite haplotypes across the study region strongly suggest that specific haplotypes of S. sclerotiorum are often found on multiple crops, movement of individual haplotypes among crops is common and host identity is not a barrier to gene flow for S. sclerotiorum in the north central United States. 相似文献
11.
Kyle C. Costa Joy Hallmark Jason B. Navarro Brian P. Hedlund Duane P. Moser Stephanie Labahn 《Geomicrobiology journal》2013,30(5):250-259
The geochemistry and microbiology of two ephemeral playa lakes in the Western United States, Surprise Valley Alkali Lake (SVAL) and Eldorado Playa (EP), were examined over one wetting cycle, revealing dramatic temporal changes in suspended mineralogy, aqueous chemistry, and bacterial populations. In SVAL the predominant suspended mineral changed from smectite to vermiculite and clinoptilolite, which led to a depletion of soluble Mg2+. Nitrate became depleted in both playas as a result of biological nitrogen demand imparted by unusually dense microbial communities reaching ~1 × 108 cultivable heterotrophs per ml of water. One hundred eighty eight bacterial isolates were obtained, representing sixty phylotypes and four phyla: Actinobacteria, Bacteroidetes, Proteobacteria, and Firmicutes. Phylogenetic analyses suggested that the microbial communities reflected different phases of succession, with SVAL changing from a diverse community with abundant Yonghaparkia to a less diverse late summer community with abundant Bacteroidetes and Proteobacteria such as Loktanella, Rhodobaca, Saccharospirillum, Flexibacter, and phylogenetically novel members of the Flexibacteriaceae. In EP, a diverse assemblage of bacteria often associated with soils was replaced very quickly by a much less even community dominated by Yonghaparkia, Sandarakinorhabdus, and relatives of Belliella baltica. Strikingly, the early summer microbial community from SVAL was not significantly different from the EP community that developed within one week of flooding, even though these playas are almost 1000 km apart, whereas sympatric communities in different phases of succession were different. To our knowledge, this is one of the first geomicrobiological studies of a recharge playa, the dominant playa type worldwide. 相似文献
12.
13.
Survey of Infectious Multiple Drug Resistance Among Salmonella Isolated from Animals in the United States 总被引:4,自引:2,他引:2
下载免费PDF全文
![点击此处可从《Applied microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Salmonella cultures were obtained from outbreaks of animal disease from 37 states and 1 territory. They were screened for resistance to 11 antimicrobial drugs. Of the 1,251 strains studied, 935 were resistant to one or more of these agents. The three most common resistance patterns were ampicillin, dihydrostreptomycin, sulfamethoxypyridazine, tetracycline; ampicillin, dihydrostreptomycin, sulfamethoxypyridazine; dihydrostreptomycin, sulfamethoxypyridazine, tetracycline. Resistance transfer was demonstrated on 267 multiply resistant cultures, of which 181 were able to transfer all or part of their resistance pattern to a drug-sensitive recipient. 相似文献
14.
D P Smith 《Social biology》1985,32(1-2):53-60
The breastfeeding of US infants born in 1974-76 is analyzed using data form the 1976 National Survey of Family Growth. Life table estimates of the proportion of children breastfed by duration since birth and mean breastfeeding durations are presented. The life tables reported are constructed by standard cohort table methods. To compare life tables for children of mothers in various attribute categories, generalised Wilcoxon tests are used, together with multiple classification analysis for continuation at select durations. Variables considered include mother's age at the birth, ethnicity, educational level, education by ethnicity, region of residence and the child's birth order. Findings are restricted to infants remaining with their mothers for at least 2 months following delivery and surviving as of the survey date in January-September 1976. It is found that the proportion of infants breastfed was increasing rapidly, with the highest rates found among white (39%), college-educated (56%), western (56%) mothers and lowest rates among black mothers (17%) mothers with less than a high school education (19%) and mothers living in the south (24%). By age, the highest proportions are mothers at ages 25-29 (44%), followed closely by the mothers under 25 (29%). The proportions breastfeeding were also found to be higher in urban than in rural areas (38% vs. 28%) and higher at parities 1-2 (29%). A multiple classification analysis of the factors most strongly influencing breastfeeding in 1975 shows educational level to be the strongest single predictor of breastfeeding, followed by western residence and white ethnicity. Age effects were found to correlate strongly with education. Reviewing 1971-1981 changes, the proportion of mothers with less than a college education who breastfed their children increased from 19% to 51% over the decade, while the proportion among college-educated mothers rose from 42% to 74%. For children who were breastfed, the median duration was about 4.5 months. The mean was 5.5 months, with a range from about 3.0 months among black mothers with less than a high school education, to 6.0 months among college-educated white women. The nationwide changes in breastfeeding patterns and duration may confer modest health benefits on current generations of youngsters, although not benefits that are easily measured, since human milk substitutes are routinely subjected to rigourous testing for nutritional adequacy. 相似文献
15.
16.
17.
18.
19.
20.