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1.
高欣  丁森  张远  马淑芹  刘思思  孟伟 《生态学报》2015,35(21):7198-7206
河流生态系统的退化是多空间尺度环境因子作用的结果。探讨不同尺度环境因子及水生生物之间的作用关系,识别影响水生生物群落完整性的尺度问题,是有效开展水生生物保护的基础。基于2009年对太子河流域15个样点的鱼类、河岸带栖息地质量评价,结合遥感影像解译的太子河流域土地利用情况(包括流域尺度和河段尺度),研究鱼类完整性指数(F-IBI)与两种尺度土地利用、栖息地质量参数之间的关系。结果表明太子河上游地区河岸栖息地质量较好,下游地区由于农业用地、城镇用地比例的增加河岸栖息地质量明显下降。F-IBI与自然用地比例呈正相关,与农业、城镇用地比例呈负相关。农业用地对F-IBI的影响体现在流域尺度,而城镇用地在两种尺度上都存在显著影响。相比于农业用地,城镇用地相同比例的增加会导致F-IBI更快的下降。底质、水质状况、人类活动强度是显著影响F-IBI的栖息地质量评价参数。3项参数均随农业和城镇用地比例增加而降低,农业用地主要在流域尺度上对3项参数产生影响,城镇用地主要影响底质和水质状况2项参数,而在两种尺度上的影响相差不大。  相似文献   

2.
The study investigated the effects of human-induced landscape patterns on species richness in forests. For 80 plots of fixed size, we measured human disturbance (categorized as urban/industrial and agricultural land areas), at ‘local’ and ‘landscape’ scale (500 m and 2500 m radius from each plot, respectively), the distance from the forest edge, and the size and shape of the woody patch. By using GLM, we analyzed the effects of disturbance and patch-based measures on both total species richness and the richness of a group of specialist species (i.e. the ‘ancient forest species’), representing more specific forest features. Patterns of local species richness were sensitive to the structure and composition of the surrounding landscape. Among the landscape components taken into account, urban/industrial land areas turned out as the most threatening factor for both total species richness and the richness of the ancient forest species. However, the best models evidenced a different intensity of the response to the same disturbance category as well as a different pool of significant variables for the two groups of species. The use of groups of species, such as the ancient forest species pool, that are functionally related and have similar ecological requirements, may represent an effective solution for monitoring forest dynamics under the effects of external factors. The approach of relating local assessment of species richness, and in particular of the ancient forest species pool, to land-use patterns may play an important role for the science-policy interface by supporting and strengthening conservation and regional planning decision making.  相似文献   

3.

Background

Poverty due to illness has become a substantial social problem in rural China since the collapse of the rural Cooperative Medical System in the early 1980s. Although the Chinese government introduced the New Rural Cooperative Medical Schemes (NRCMS) in 2003, the associations between different health insurance benefit package designs and healthcare utilization remain largely unknown. Accordingly, we sought to examine the impact of health insurance benefit design on health care utilization.

Methods and Findings

We conducted a cross-sectional study using data from a household survey of 15,698 members of 4,209 randomly-selected households in 7 provinces, which were representative of the provinces along the north side of the Yellow River. Interviews were conducted face-to-face and in Mandarin. Our analytic sample included 9,762 respondents from 2,642 households. In each household, respondents indicated the type of health insurance benefit that the household had (coverage for inpatient care only or coverage for both inpatient and outpatient care) and the number of outpatient visits in the 30 days preceding the interview and the number of hospitalizations in the 365 days preceding the household interview. People who had both outpatient and inpatient coverage compared with inpatient coverage only had significantly more village-level outpatient visits, township-level outpatient visits, and total outpatient visits. Furthermore, the increased utilization of township and village-level outpatient care was experienced disproportionately by people who were poorer, whereas the increased inpatient utilization overall and at the county level was experienced disproportionately by people who were richer.

Conclusion

The evidence from this study indicates that the design of health insurance benefits is an important policy tool that can affect the health services utilization and socioeconomic equity in service use at different levels. Without careful design, health insurance may not benefit those who are most in need of financial protection from health services expenses.  相似文献   

4.
5.
Male-specific (F+) coliphages have been investigated as viral indicators of fecal contamination that may provide source-specific information for impacted environmental waters. This study examined the presence and proportions of the different subgroups of F+ coliphages in a variety of fecal wastes and surface waters with well-defined potential waste impacts. Municipal wastewater samples had high proportions of F+ DNA and group II and III F+ RNA coliphages. Bovine wastewaters also contained a high proportion of F+ DNA coliphages, but group I and IV F+ RNA coliphages predominated. Swine wastewaters contained approximately equal proportions of F+ DNA and RNA coliphages, and group I and III F+ RNA coliphages were most common. Waterfowl (gull and goose) feces contained almost exclusively F+ RNA coliphages of groups I and IV. No F+ coliphages were isolated from the feces of the other species examined. F+ coliphage recovery from surface waters was influenced by precipitation events and animal or human land use. There were no significant differences in coliphage density among land use categories. Significant seasonal variation was observed in the proportions of F+ DNA and RNA coliphages. Group I F+ RNA coliphages were the vast majority (90%) of those recovered from surface waters. The percentage of group I F+ RNA coliphages detected was greatest at background sites, and the percentage of group II F+ RNA coliphages was highest at human-impacted sites. Monitoring of F+ coliphage groups can indicate the presence and major sources of microbial inputs to surface waters, but environmental effects on the relative occurrence of different groups need to be considered.  相似文献   

6.
7.
Objective To evaluate the effect of implementing comprehensive, integrated electronic health record systems on use and quality of ambulatory careDesign Retrospective, serial, cross sectional study.Setting Colorado and Northwest regions of Kaiser Permanente, a US integrated healthcare delivery system.Population 367 795 members in the Colorado region and 449 728 members in the Northwest region.Intervention Implementation of electronic health record systems.Main outcome measures Total number of office visits and use of primary care, specialty care, clinical laboratory, radiology services, and telephone contact. Health Plan Employer Data and Information Set to assess quality.Results Two years after electronic health records were fully implemented, age adjusted rates of office visits fell by 9% in both regions. Age adjusted primary care visits decreased by 11% in both regions and specialty care visits decreased by 5% in Colorado and 6% in the Northwest. All these decreases were significant (P < 0.0001). The percentage of members making ≥ 3 visits a year decreased by 10% in Colorado and 11% in the Northwest, and the percentage of members with ≤ 2 visits a year increased. In the Northwest, scheduled telephone contact increased from a baseline of 1.26 per member per year to 2.09 after two years. Use of clinical laboratory and radiology services did not change conclusively. Intermediate measures of quality of health care remained unchanged or improved slightly.Conclusions Readily available, comprehensive, integrated clinical information reduced use of ambulatory care while maintaining quality and allowed doctors to replace some office visits with telephone contacts. Shifting patterns of use suggest reduced numbers of ambulatory care visits that are inappropriate or marginally productive.  相似文献   

8.
9.
Redstart and black redstart inhabit different types of habitats under natural conditions. However, they come into close contact in a mosaic urban environment. Mechanisms enabling their local coexistence were looked for. We found that: 1) The two species occupied exclusive territories of different habitat compositions. 2) Territories differed in the proportion of trees and buildings. 3) Within their territories, the two species used the same foraging techniques, but with different frequencies. 4) Prey size was similar, but the proportions of taxonomic groups differed. 5) Spontaneous interspecific conflicts were observed. Interspecific aggression was confirmed in playback experiments. The black redstart was dominant in both natural and simulated encounters. We conclude that the main mechanism enabling coexistence of the two redstarts in a mosaic urban environment is different habitat selection with the proportion of trees as a key parameter. This proportion was always below 26% in black redstart territories, and above 27% in redstart territories. This is consistent with the habitat preferences these two species show in non-urban conditions. This pattern is compared to the other cases of coexistence of congeneric bird species such as chickadees Poecile or Sylvia warblers. As the two redstart species are able to hybridise in the wild, the observed interspecific aggression may operate as a pre-copulation barrier.  相似文献   

10.
The bacteria resident in sponges collected from Chuuk Lagoon and Kosrae Island of Micronesia were investigated using the 16S rRNA gene PCR-tagged pyrosequencing method. These sponges were clustered into 5 groups based on their bacterial composition. Diversity indexes and cumulative rank abundance curves showed the different compositions of bacterial communities in the various groups of sponges. Reads related to the phylum Chloroflexi were observed predominantly (9.7–68.2%) in 9 sponges of 3 groups and unobserved in the other 2 groups. The Chloroflexi-containing group had similar bacterial patterns at the phylum and lower taxonomic levels, for example, significant proportions of Acidobacteria, Gemmatimonadetes, SBR1093, and PAUC34f were observed in most members of this group. The three groups in the Chloroflexi-containing group, however, showed some minor differences in the composition and diversity. The other two groups contained high proportions of Proteobacteria (>87%) or Bacteroidetes (>61%) and different composition and diversity compared to the Chloroflexi-containing group and each other. Four pairs of specimens with the same species showed similar bacterial profiles, but, the bacteria in sponges were highly specific at the individual level.  相似文献   

11.
We employ a cellular-automata to reconstruct the land use patterns of cities that we characterize by two measures of spatial heterogeneity: (a) a variant of spatial entropy, which measures the spread of residential, business, and industrial activity sectors, and (b) an index of dissimilarity, which quantifies the degree of spatial mixing of these land use activity parcels. A minimalist and bottom-up approach is adopted that utilizes a limited set of three parameters which represent the forces which determine the extent to which each of these sectors spatially aggregate into clusters. The dispersion degrees of the land uses are governed by a fixed pre-specified power-law distribution based on empirical observations in other cities. Our method is then used to reconstruct land use patterns for the city state of Singapore and a selection of North American cities. We demonstrate the emergence of land use patterns that exhibit comparable visual features to the actual city maps defining our case studies whilst sharing similar spatial characteristics. Our work provides a complementary approach to other measures of urban spatial structure that differentiate cities by their land use patterns resulting from bottom-up dispersion and aggregation processes.  相似文献   

12.

Background

Urban population in China is mainly covered by two medical insurance schemes: the Urban Employee Basic Medical Insurance (UEBMI) for urban employees in formal sector and the Urban Resident Basic Medical Insurance (URBMI) for the left urban residents, mainly the unemployed, the elderly and children. This paper studies the effects of UEBMI and URBMI on health services utilisation in Shaanxi Province, Western China.

Methods

Cross-sectional data from the 4th National Health Services Survey - Shaanxi Province was studied. The propensity score matching and the coarsened exact matching methods have been used to estimate the average medical insurance effect on the insured.

Results

Compared to the uninsured, robust results suggest that UEBMI had significantly increased the outpatient health services utilisation in the last two weeks (p<0.10), whilst the significant effect on hospitalisation was evident in the CEM method (p<0.10). The effect of URBMI was limited in that although being insured was associated with higher health services utilisation, compared with the uninsured, none of the improvement was statistically significant (p>0.10). It was also found that compared with the uninsured, basic medical insurance enrollees were more likely to purchase inpatient treatments in lower levels of hospitals, consistent with the incentive of the benefit package design.

Conclusion

Basic Medical insurance schemes have shown a positive but limited effect on increasing health services utilisation in Shaanxi Province. The benefit package design of higher reimbursement rates for lower level hospitals has induced the insured to use medical services in lower level hospitals for inpatient services.  相似文献   

13.
Aim We examine how two categories of non‐native species (archaeophyte and neophyte, introduced before and after ad 1500, respectively) have had different impacts on β diversity across European urban floras. Our goal is to use the unique biological perspective provided by urban areas, and the contrasting historical and geographical perspectives provided by archaeophytes and neophytes, to infer how non‐native species will impact upon β diversity in the future. Location Twenty‐two urban areas located in seven European countries. Methods We used the β‐sim dissimilarity index to estimate the level of β diversity for 231 unique pair‐wise combinations of 22 urban floras. We examined bivariate plots of dissimilarity by geographical separation of city centres to evaluate distance decay of similarity for native species, archaeophytes and neophytes. Results Based on average percentages, 52.8% (SD = 8.2%) of species in the urban floras were identified as non‐native with 28.3% (SD = 6.9%) classified as neophytes and 24.5% (SD = 4.9%) as archaeophytes. Relative to native species, across urban floras, archaeophytes were associated with higher compositional similarity and weaker distance decay patterns, whereas neophytes were associated with lower compositional similarity and stronger distance decay patterns. Main conclusions Across European urban floras, archaeophytes and neophytes occurred in similar numbers but archaeophytes were consistently associated with lower β diversity and neophytes with higher β diversity. Thus, the impact of non‐native species on β diversity can be determined, at least in part, through their historical and geographical associations with anthropogenic activities. If archaeophytes represent the long‐term biogeographical outcome for human commensal species, neophytes could develop similar patterns. The consequences, however, are likely to be more substantial ecologically and geographically due to the increasing numbers of neophytes and their global anthropogenic associations. Nevertheless, at present, our findings suggest that, based on occurrence information, neophytes have not achieved this state with European urban floras retaining regionally distinct assemblages of neophytes.  相似文献   

14.

Background

Many patients treated in Emergency Department (ED) visits can be treated at primary or urgent care sectors, despite the fact that a number of ED visitors seek other forms of care prior to an ED visit. However, little is known regarding how the pre-ED activity episodes affect ED visits.

Objectives

We investigated whether care-seeking patterns involve the use of health care services of various types prior to ED visits and examined the associations of these patterns with the severity of the presenting condition for the ED visit (EDVS) and subsequent events.

Methods

This retrospective observational study used administrative data on beneficiaries of the universal health care insurance program in Taiwan. The service type, treatment capacity, and relative diagnosis were used to classify pre-ED visits into 8 care types. Frequent pattern analysis was used to identify sequential care-seeking patterns and to classify 667,183 eligible pre-ED episodes into patterns. Generalized linear models were developed using generalized estimating equations to examine the associations of these patterns with EDVS and subsequent events.

Results

The results revealed 17 care-seeking patterns. The EDVS and likelihood of subsequent events significantly differed among patterns. The ED severity index of patterns differ from patterns seeking directly ED care (coefficients ranged from -0.05 to 0.13), and the odds-ratios for the likelihood of subsequent ED visits and hospitalization ranged from 1.18 to 1.86 and 1.16 to 2.84, respectively.

Conclusions

The pre-ED care-seeking patterns differ in severity of presenting condition and subsequent events that may represent different causes of ED visit. Future health policy maker may adopt different intervention strategies for targeted population to reduce unnecessary ED visit effectively.  相似文献   

15.
Cross-taxon congruence has been suggested as an efficient tool in conservation planning and biodiversity monitoring. It corresponds to the degree to which patterns in assemblage structure in a set of sites are similar among different taxonomic groups. If different groups ordinate the sampling sites similarly, they are concordant and this information is frequently used as an indicative that one group could be used as a surrogate for the other. Using spatiotemporal benthic data from a biodiverse coastal ecosystem (the Araçá Bay in southeast Brazil), we first assessed if macro- and meiofaunal assemblages inhabiting marine soft-sediments show concordant patterns. Then, we used multi- and univariate analysis to examine the relationship of both groups with the environment. Macro- and meiofaunal assemblages exhibited strong congruent patterns in all periods analyzed. Moreover, both groups responded to similar environmental features and their ordination patterns matched those generated by the environmental data. These results show that the patterns of concordance are probably mediated by similar responses to environmental gradients. Overall, our results suggest the potential for use of the surrogacy approach in conservation planning and monitoring purposes of marine benthic biodiversity, and that macro- and meiofauna can be used as a surrogate for each other.  相似文献   

16.
Zhao D  Li F  Wang R S 《农业工程》2012,32(3):144-149
Soil microbes are affected by various abiotic and biotic factors in urban ecosystem due to land use change. The effects of different land use patterns on soil microbial properties and soil quality are, however, largely unknown. This study compared soil nutrient status, microbial biomass nitrogen and enzyme activities under five different land use patterns—nature forest, park, farmland, street green, and roadside tree sites at various soil depths in Beijing, China. The results showed that soil properties were significantly affected by urban land use patterns and soil depths in the urban environment. Compared to forest sites, soil nutrients were markedly decreased in other land use patterns, except the highest soil organic matter content in roadside tree sites in 0–10 cm soil layer. Soil microbial biomass nitrogen showed the order as follows: nature forest > park > farmland > street green > roadside tree in 0–10 cm soil layer, and it decreased along with the soil depth gradient. Furthermore, urease activity was highest in nature forest and lowest in street green and roadside tree soils in each depth, while the activity of protease ranged between 0.84 and 3.94 mg g?1 with the peak appeared in roadside tree at 30–40 cm soil layers. Nitrate reductase activity was also extremely higher in street green than other land use patterns. Correlation analyses suggested that change of soil microbial biomass and enzyme activity in different land use patterns were mainly controlled by nutrient availability and soil fertility in urban soils.  相似文献   

17.
The global trade of goods is associated with a virtual transfer of the water required for their production. The way changes in trade affect the virtual redistribution of freshwater resources has been recently documented through the analysis of the virtual water network. It is, however, unclear how these changes are contributed by different types of products and regions of the world. Here we show how the global patterns of virtual water transport are contributed by the trade of different commodity types, including plant, animal, luxury (e.g., coffee, tea, and alcohol), and other products. Major contributors to the virtual water network exhibit different trade patterns with regard to these commodity types. The net importers rely on the supply of virtual water from a small percentage of the global population. However, discrepancies exist among the different commodity networks. While the total virtual water flux through the network has increased between 1986 and 2010, the proportions associated with the four commodity groups have remained relatively stable. However, some of the major players have shown significant changes in the virtual water imports and exports associated with those commodity groups. For instance, China has switched from being a net exporter of virtual water associated with other products (non-edible plant and animal products typically used for manufacturing) to being the largest importer, accounting for 31% of the total water virtually transported with these products. Conversely, in the case of The United states of America, the commodity proportions have remained overall unchanged throughout the study period: the virtual water exports from The United States of America are dominated by plant products, whereas the imports are comprised mainly of animal and luxury products.  相似文献   

18.
Low birth weight is the major determinant of infant mortality. Continuing declines in infant mortality in the United States are due to the use of neonatal intensive care services; less progress has been made toward preventing low birth weight. I examined how the demographic, socioeconomic, and health services use variables affected rates of low birth weights in Pima County, Arizona, in 1985. Women at greatest risk of having the smallest infants were those younger than 21 years and those with fewer than 6 prenatal visits. Nulliparous women with fewer than 6 prenatal visits showed a still greater risk of having an infant of low birth weight. Women without medical insurance coverage had babies with the lowest mean birth weights, as well as significantly fewer prenatal visits. As the number of uninsured in the United States increases, the effect of lack of insurance among pregnant women becomes increasingly important. To prevent low-weight births, comprehensive maternity care services must be available to all pregnant women regardless of ability to pay.  相似文献   

19.
全自动生化分析仪的发展及市场概况   总被引:1,自引:0,他引:1  
随着中国国内城乡国民医疗保险事业的普及和持续发展,城乡各级医院生化实验室应用自动生化分析仪的需求越来越迫切。本文就其现状作一基本论述。  相似文献   

20.
新疆城镇化与土地资源产出效益的空间分异及其协调性   总被引:2,自引:0,他引:2  
杨宇  刘毅  董雯  李莉 《生态学报》2011,31(21):6568-6578
通过探索性空间分析以及协调发展度函数对1995-2008年新疆城镇化水平和土地资源产出效益的空间效应及两者之间的协调发展程度进行了系统分析,得出结论:(1)新疆各县市城镇化水平和土地资源产出效益在空间上均呈现明显的空间集聚。总体而言天山北坡和南疆铁路沿线是城镇化和土地资源产出效益热点相对集中的区域。(2)从协调发展度来看,整体上呈现纺锤体结构,"弱者恒弱"的马太效应难以打破,南北疆城镇呈现不同的演变轨迹。(3)将新疆所有城镇分为同步协调型、城镇化滞后型、土地效益滞后型、逐步磨合型、低级协调型五种类型,其中同步协调型城镇较少,其他类型的城镇数量较为均等。  相似文献   

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