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1.
SPECIAL EDITOR''S NOTE: Constance B. Wofsy, MD, is Co-Director of AIDS Activities at San Francisco General Hospital and Medical Center, as well as Associate Clinical Professor of Medicine at the University of California, San Francisco; Assistant Chief, Infectious Diseases, San Francisco General Hospital; and Principal Investigator, Project AWARE (Association for Women''s AIDS Research and Education). Although she was not able to contribute an article for WOMEN AND MEDICINE on this very important subject, she kindly agreed to an interview. Both physicians and nonphysicians were asked what questions they had about the acquired immunodeficiency syndrome (AIDS) and the human immunodeficiency virus (HIV) in women.  相似文献   

2.
In 2007, the first confirmed case of Cryptococcus gattii was reported in the state of North Carolina, USA. An otherwise healthy HIV negative male patient presented with a large upper thigh cryptococcoma in February, which was surgically removed and the patient was started on long-term high-dose fluconazole treatment. In May of 2007, the patient presented to the Duke University hospital emergency room with seizures. Magnetic resonance imaging revealed two large CNS lesions found to be cryptococcomas based on brain biopsy. Prior chest CT imaging had revealed small lung nodules indicating that C. gattii spores or desiccated yeast were likely inhaled into the lungs and dissemination occurred to both the leg and CNS. The patient''s travel history included a visit throughout the San Francisco, CA region in September through October of 2006, consistent with acquisition during this time period. Cultures from both the leg and brain biopsies were subjected to analysis. Based on phenotypic and molecular methods, both isolates were C. gattii, VGI molecular type, and distinct from the Vancouver Island outbreak isolates. Based on multilocus sequence typing of coding and noncoding regions and virulence in a heterologous host model, the leg and brain isolates are identical, but the two differed in mating fertility. Two clinical isolates, one from a transplant recipient in San Francisco and the other from Australia, were identical to the North Carolina clinical isolate at all markers tested. Closely related isolates that differ at only one or a few noncoding markers are present in the Australian environment. Taken together, these findings support a model in which C. gattii VGI was transferred from Australia to California, possibly though an association with its common host plant E. camaldulensis, and the patient was exposed in San Francisco and returned to present with disease in North Carolina.  相似文献   

3.
Budgets for species conservation limit actions. Expending resources in areas of high human density is costly and generally considered less likely to succeed. Yet, coastal California contains both a large fraction of narrowly endemic at-risk plant species as well as the state''s three largest metropolitan regions. Hence understanding the capacity to protect species along the highly urbanized coast is a conservation priority. We examine at-risk plant populations along California''s coastline from San Diego to north of San Francisco to better understand whether there is a relationship between human population density and: i) performance of at-risk plant populations; and ii) conservation spending. Answering these questions can help focus appropriate strategic conservation investment. Rare plant performance was measured using the annualized growth rate estimate between census periods using the California Natural Diversity Database. Human density was estimated using Census Bureau statistics from the year 2000. We found strong evidence for a lack of a relationship between human population density and plant population performance in California''s coastal counties. Analyzing US Endangered Species expenditure reports, we found large differences in expenditures among counties, with plants in San Diego County receiving much higher expenditures than other locations. We found a slight positive relationship between expenditures on behalf of endangered species and human density. Together these data support the argument that conservation efforts by protecting habitats within urban environments are not less likely to be successful than in rural areas. Expenditures on behalf of federally listed endangered and threatened plants do not appear to be related to proximity to human populations. Given the evidence of sufficient performance in urban environments, along with a high potential to leverage public support for nature in urban environments, expenditures in these areas appear to be an appropriate use of conservation funds.  相似文献   

4.
Invasive species frequently degrade habitats, disturb ecosystem processes, and can increase the likelihood of extinction of imperiled populations. However, novel or enhanced functions provided by invading species may reduce the impact of processes that limit populations. It is important to recognize how invasive species benefit endangered species to determine overall effects on sensitive ecosystems. For example, since the 1990s, hybrid Spartina (Spartina foliosa × alterniflora) has expanded throughout South San Francisco Bay, USA, supplanting native vegetation and invading mudflats. The endangered California clapper rail (Rallus longirostris obsoletus) uses the tall, dense hybrid Spartina for cover and nesting, but the effects of hybrid Spartina on clapper rail survival was unknown. We estimated survival rates of 108 radio-marked California clapper rails in South San Francisco Bay from January 2007 to March 2010, a period of extensive hybrid Spartina eradication, with Kaplan–Meier product limit estimators. Clapper rail survival patterns were consistent with hybrid Spartina providing increased refuge cover from predators during tidal extremes which flood native vegetation, particularly during the winter when the vegetation senesces. Model averaged annual survival rates within hybrid Spartina dominated marshes before eradication (? = 0.466) were greater than the same marshes posttreatment (? = 0.275) and a marsh dominated by native vegetation (? = 0.272). However, models with and without marsh treatment as explanatory factor for survival rates had nearly equivalent support in the observed data, lending ambiguity as to whether hybrid Spartina facilitated greater survival rates than native marshland. Conservation actions to aid in recovery of this endangered species should recognize the importance of available of high tide refugia, particularly in light of invasive species eradication programs and projections of future sea-level rise.  相似文献   

5.
Reported suicide in San Francisco was investigated for the period between July 1956, through June 1964. During that time 1664 persons killed themselves, according to the Coroner''s records. The method most frequently used was oral ingestion of toxic substances, which significantly deviates from national statistics, shooting being the method most frequently reported. The explanation for this deviation is probably the more valid mortality statistics of San Francisco, and from this it may be inferred that unreported suicide may be largely suicide by ingestion, unrecognized because of lack of postmortem studies.Unreported suicide is further classified into intentioned (masked, suppressed and undiscovered) and subintentioned (oral-dependent and aggressive).Despite the fact that suicide has been a leading cause of death, the public and the medical profession are largely apathetic. An attempt is being made by Suicide Prevention of San Francisco, Inc. to develop a clinical and research facility for the study and treatment of suicidal persons.  相似文献   

6.
Substantial amounts of soluble wheat antigens have been found in breads sold as “wheat-free” in the San Francisco Bay Area. Physicians with patients on a wheat-free diet are urged to exercise careful supervision over their patients'' choice of such breads.  相似文献   

7.
上海轨道交通对城市土地利用变化的影响   总被引:3,自引:0,他引:3  
利用1989、2005年上海市1∶50 000彩红外航空遥感影像解译的土地利用数据,基于GIS技术,定量研究了上海轨道交通对城市土地利用动态变化的影响,并用Markov模型对研究区2010—2025年间的土地利用变化进行了初步预测.结果表明:轨道交通加快了上海市土地利用的转化,促进了以耕地为主的自然景观向居住、公共设施用地等土地获益较高的人工景观转化;轨道交通增加了研究区的土地利用程度;1989—2005年,研究区其他用地(以在建用地为主,下同)、公共设施用地、绿地、耕地、水域的转化率较大,其中,其他用地的变化速度最快,水域的变化速度最慢;2010—2025年,耕地、水域的面积和比例将继续减少,居住、公共设施用地等人工景观的面积则呈继续增加的趋势.从提高土地利用程度和土地获益的角度,轨道交通沿线的这种土地利用结构仍需要进一步调整,以增加土地的集约化程度和实现土地资源的可持续利用.  相似文献   

8.
Events leading to the planting of the first soybeans in Illinois and the subsequent distribution of the seed throughout the United States are documented. In December 1850 theAuckland left Hong Kong for San Francisco. The ship came across a Japanese junk floundering on the sea. The Japanese crew was removed from the junk and placed on board theAuckland, which continued on to San Francisco. In March 1851 Dr. Benjamin Franklin Edwards obtained soybean seeds from the Japanese and brought the seeds to Alton, Illinois. Mr. John H. Lea of Alton planted the soybeans in his garden in summer 1851. These events took place 3 yr prior to the famous introduction of soybeans from Japan into the United States by the Perry Expedition.  相似文献   

9.
Fragmentation and loss of natural habitat have important consequences for wild populations and can negatively affect long-term viability and resilience to environmental change. Salt marsh obligate species, such as those that occupy the San Francisco Bay Estuary in western North America, occupy already impaired habitats as result of human development and modifications and are highly susceptible to increased habitat loss and fragmentation due to global climate change. We examined the genetic variation of the California Ridgway’s rail (Rallus obsoletus obsoletus), a state and federally endangered species that occurs within the fragmented salt marsh of the San Francisco Bay Estuary. We genotyped 107 rails across 11 microsatellite loci and a single mitochondrial gene to estimate genetic diversity and population structure among seven salt marsh fragments and assessed demographic connectivity by inferring patterns of gene flow and migration rates. We found pronounced genetic structuring among four geographically separate genetic clusters across the San Francisco Bay. Gene flow analyses supported a stepping stone model of gene flow from south-to-north. However, contemporary gene flow among the regional embayments was low. Genetic diversity among occupied salt marshes and genetic clusters were not significantly different. We detected low effective population sizes and significantly high relatedness among individuals within salt marshes. Preserving genetic diversity and connectivity throughout the San Francisco Bay may require attention to salt marsh restoration in the Central Bay where habitat is both most limited and most fragmented. Incorporating periodic genetic sampling into the management regime may help evaluate population trends and guide long-term management priorities.  相似文献   

10.
全球四大湾区生态环境综合评价研究   总被引:5,自引:1,他引:4  
全球四大湾区既是经济发达区,也是生态环境脆弱区,对全球可持续发展至关重要。粤港澳大湾区的生态环境问题正在限制其可持续发展,有碍于全面建成国际一流湾区目标的实现。然而,过去的研究对生态环境方面关注较少,缺少湾区生态环境综合评价体系的构建。通过综合国内外统计和遥感多源数据,建立四大湾区生态环境评价数据库;围绕生态质量,环境质量和资源利用效率建立指标体系,构建湾区生态环境综合评价指数。结果表明:2015年,生态环境综合评价,东京湾区 > 旧金山湾区 > 纽约湾区 > 粤港澳大湾区;生态质量,纽约湾区 > 旧金山湾区 > 粤港澳大湾区 > 东京湾区;环境质量,旧金山湾区 > 东京湾区 > 纽约湾区 > 粤港澳大湾区;资源利用效率,东京湾区 > 旧金山湾区 > 纽约湾区 > 粤港澳大湾区。2005-2015年,粤港澳大湾区环境质量增速缓慢,在生态质量和资源利用效率增幅排名首位。旧金山湾区和纽约湾区优势在生态和环境质量,短板在资源利用效率;东京湾区在资源利用效率方面优势明显,短板在生态质量;综合来看,粤港澳大湾区与其他湾区都存在差距。研究建议粤港澳大湾区从生态空间、生态环境治理和资源利用方面,吸取发达国家湾区的经验。  相似文献   

11.
韩丹  王成  殷鲁秦 《生态学报》2021,41(22):8892-8905
物种间相互作用网络研究能为物种多样性的保护、城市生态系统稳定性的维持提供指导。基于群落水平的城市蝴蝶蜜源植物互作网络的研究较少,对城市蝴蝶蜜源网络结构缺乏深入认识。研究在国内城市生态系统中构建蝴蝶蜜源网络,并探讨不同类型植物对网络特征的影响。2020年6-9月,在北京26个城市公园中记录访花蝴蝶和蜜源植物物种及互作频次,采用交互多样性(ID)、交互均匀性(IE)、专业化程度(H2'')定量化生态网络结构特征,采用Kruskal-Wallis秩和检验和变差分解分析不同生长型、起源、栽培方式的植物类型对网络结构的影响差异。采用物种的伙伴多样性(PD)和专业化程度(d'')识别重要蜜源植物。研究结果表明:(1)北京城市公园中22种蝴蝶与81种开花植物的交互作用,形成趋于泛化的生态网络结构;(2)不同生长型及不同起源的植物-蝴蝶网络的交互多样性及专业化程度有显著差异,草本及乡土植物对丰富网络中交互多样性和支持专业性更高的蝴蝶物种具重要作用,而植物的栽培方式对蜜源网络结构影响较小;(3)伙伴多样性高且专业化程度高的植物可被视为重要蜜源植物。基于蝴蝶多样性保护的目标,在城市生态系统中,绿色空间应注重构建乡土草本植物群落,优先选择重要蜜源植物。我们的发现印证了蝴蝶-蜜源植物生态网络方法作为联结生态研究和城市绿地实践管理的有效工具,能为城市生态系统中生物多样性保护提供科学策略,具有重要意义。  相似文献   

12.
We introduce an algorithm able to reconstruct the relevant network structure on which the time evolution of country-product bipartite networks takes place. The significant links are obtained by selecting the largest values of the projected matrix. We first perform a number of tests of this filtering procedure on synthetic cases and a toy model. Then we analyze the bipartite network constituted by countries and exported products, using two databases for a total of almost 50 years. It is then possible to build a hierarchically directed network, in which the taxonomy of products emerges in a natural way. We study the influence of the structure of this taxonomy network on countries'' development; in particular, guided by an example taken from the industrialization of South Korea, we link the structure of the taxonomy network to the empirical temporal connections between product activations, finding that the most relevant edges for countries'' development are the ones suggested by our network. These results suggest paths in the product space which are easier to achieve, and so can drive countries'' policies in the industrialization process.  相似文献   

13.
In 1980 a long-term study of the fishery resources of the San Francisco Bay estuary was initiated in an effort to delineate the importance of freshwater inflow to fish and invertebrate abundance and distribution in the bay. An analysis of the trawl data collected between January 1980 and December 1982 illustrates the influence of the timing and magnitude of freshwater inflows on fish fistribution and abundance in this estuary from the perspective of monthly, seasonal and annual time scales. Normally found in the delta, Suisun Bay and San Pablo Bay during periods of increased salinity, pelagic species moved downstream after the two peak flows studied, while demersal species usually found in Central San Francisco Bay moved upstream. Such upstream movements may be due in part to transport by strong density-driven currents.Timing and magnitude of monthly catches of some species varied on a seasonal cycle coincident with variations of freshwater inflow. Most species, especially the marine species, showed no consistent cycle of monthly catches. In the wet years of 1980 and 1982 the distributions of freshwater, estuarine and anadromous species were extended downstream into San Pablo, Central and South San Francisco Bays and some marine species, including the flatfish, were more abundant in the upstream areas. In the dry year of 1981 when bay salinities were higher, few marine species extended their distributions upstream into San Pablo and Suisun Bays. Jacksmelt was the only fish of the 15 most abundant species with its peak abundance in 1981. Most marine species were more abundant in the San Francisco Bay estuary in the wet years.  相似文献   

14.
Pollinator-plant relationships are found to be particularly vulnerable to land use change. Yet despite extensive research in agricultural and natural systems, less attention has focused on these interactions in neighboring urban areas and its impact on pollination services. We investigated pollinator-plant interactions in a peri-urban landscape on the outskirts of the San Francisco Bay Area, California, where urban, agricultural, and natural land use types interface. We made standardized observations of floral visitation and measured seed set of yellow starthistle (Centaurea solstitialis), a common grassland invasive, to test the hypotheses that increasing urbanization decreases 1) rates of bee visitation, 2) viable seed set, and 3) the efficiency of pollination (relationship between bee visitation and seed set). We unexpectedly found that bee visitation was highest in urban and agricultural land use contexts, but in contrast, seed set rates in these human-altered landscapes were lower than in natural sites. An explanation for the discrepancy between floral visitation and seed set is that higher plant diversity in urban and agricultural areas, as a result of more introduced species, decreases pollinator efficiency. If these patterns are consistent across other plant species, the novel plant communities created in these managed landscapes and the generalist bee species that are favored by human-altered environments will reduce pollination services.  相似文献   

15.
Invasive species are cited as being a threat to communities and ecosystems worldwide, yet few studies have demonstrated invader impacts at these scales. Lack of historic data makes capturing large-scale community shifts problematic. We assessed long-term changes in invertebrate composition to the fouling community of a small estuary with relatively little boat traffic and no ballast water input (Morro Bay, CA). We also compared relative invasiveness of Morro Bay to international harbors (San Francisco Bay and Los Angeles/San Diego harbors). While the proportion of introduced species has not significantly changed from historic records, introduced species now occupy 86.00 % of the primary substrate. Other community shifts include; (1) a state shift to an invasive bryozoan (Watersipora subtorquata) dominated community, (2) a decrease in Mollusc richness and, (3) substantial shifts in abundance of certain species. Compared to larger more actively used harbors, Morro Bay has proportionally fewer introduced species (12.00 %) than San Francisco Bay (50.79 %) or Los Angeles/San Diego Harbors (26.23 %). Our study documents changes to a small relatively isolated estuary with little boat traffic and no ballast water input. We discuss the potential role of invasive species and other natural and anthropogenic factors as drivers of these community wide shifts. Specifically, we discuss how reintroduction of the Southern Sea Otter (Enhydra lutris nereis), an increase in sea stars (Pisaster spp.), climate change and interaction amongst potential drivers support the patterns of shifts in the Morro Bay community.  相似文献   

16.
Poisson regression models were used to evaluate associations between temperature, precipitation, days of extreme heat, and other weather changes (lagged 7 days), as well as El Niño events, with hospitalizations for acute myocardial infarction, angina pectoris, congestive heart failure, and stroke in three California regions. Temperature changes were defined as a 3 °C decrease in maximum temperature or a 3 °C increase in minimum temperature. Temperature and precipitation were analyzed separately for normal weather periods and El Niño events, and for both weather periods combined. Associations varied by region, age, and gender. In Los Angeles, temperature changes resulted in small changes in hospitalizations. Among San Francisco residents 70+ years of age, temperature changes increased hospitalizations for nearly all outcomes from 6% to 13%. Associations among Sacramento residents were similar to those in San Francisco: among men 70+ years of age, temperature changes increased hospitalizations by 6%–11% for acute myocardial infarction and congestive heart failure, and 10%–18% for stroke. El Niño events were consistently and significantly associated with hospitalizations only in San Francisco and Sacramento, and then only for angina pectoris (increasing hospitalizations during El Niño events). These exploratory analyses merit further confirmation to improve our understanding of how admissions to hospitals for cardiovascular disease and stroke change with changing weather. Such an understanding is useful for developing current public health responses, for evaluating population vulnerability, and for designing future adaptation measures.  相似文献   

17.
A program for the cerebral palsied child has been developed in California which has been made possible through the cooperation of the state and local departments of education, the state and local departments of health, the Children''s Hospital and Orthopedic Hospital at Los Angeles and the University of California School of Medicine in San Francisco. An attempt is being made to deal with not only the medical and educational needs of the cerebral palsied but also the social and emotional aspects.  相似文献   

18.
As a follow-up to Wolf''s study of attitudes of obstetrical housestaff toward therapeutic abortion,5 the attitudes of 48 obstetrical residents in the San Francisco Bay area were evaluated by questionnaire and structured interview. Specific issues studied were: (1) Willingness to perform therapeutic abortion, (2) impact of therapeutic abortion on Resident Training Program, (3) attitudes toward different operational procedures, and (4) preferred physician-patient relationship with therapeutic abortion patients. Findings suggest that although there is recognition and acceptance by most residents of the social need for therapeutic abortion, considerable ambivalence persists.  相似文献   

19.
Aim Historical information about source populations of invasive species is often limited; therefore, genetic analyses are used. We compared inference about source populations from historical and genetic data for the oyster‐associated clam, Gemma gemma that invaded California from the USA Atlantic coast. Location Mid‐Atlantic (North Carolina, Maryland), Northeastern (New Jersey, New York, Massachusetts) and the California coasts (Elkhorn Slough, San Francisco Bay, Bolinas Lagoon, Tomales Bay, Bodega Harbor). Methods The documented history of transplantation of Eastern oysters to California was reviewed. Cytochrome c oxidase subunit I (COI) sequences from recent and archived clams were examined in a haplotype network. We used AMOVA to detect geographic genetic structure and a permutation test for significant reductions in diversity. Results Chesapeake Bay oysters were transplanted to New York prior to shipment to San Francisco Bay and from there to peripheral bays. Gemma in the Northeastern and Mid‐Atlantic regions were genetically differentiated. In California, populations in Bodega Harbor and Tomales Bay were genetically similar to those in the Mid‐Atlantic area while clams in San Francisco Bay, Elkhorn Slough and Bolinas Lagoon resembled populations in the Northeastern region. In California, genetic variation was not highest in San Francisco Bay despite greater magnitude of oyster plantings. Haplotypes varied over time in native and introduced populations. Main Conclusions Historical records and inferences from genetics agree that both Northeastern and Mid‐Atlantic regions were sources for Gemma in California. Only complex genetic hypotheses reconcile the strong segregation of haplotypes in California to the historical evidence of mixing in their proximate source (New York). These hypotheses include sorting of mixtures of haplotypes or selection in non‐native areas. Haplotype turnover in San Francisco and Massachusetts samples over time suggests that the sorting hypothesis is plausible. We suggest, however, that Gemma was introduced independently and recently to Tomales Bay and Bodega Harbor.  相似文献   

20.
Mitigating traffic congestion on urban roads, with paramount importance in urban development and reduction of energy consumption and air pollution, depends on our ability to foresee road usage and traffic conditions pertaining to the collective behavior of drivers, raising a significant question: to what degree is road traffic predictable in urban areas? Here we rely on the precise records of daily vehicle mobility based on GPS positioning device installed in taxis to uncover the potential daily predictability of urban traffic patterns. Using the mapping from the degree of congestion on roads into a time series of symbols and measuring its entropy, we find a relatively high daily predictability of traffic conditions despite the absence of any priori knowledge of drivers'' origins and destinations and quite different travel patterns between weekdays and weekends. Moreover, we find a counterintuitive dependence of the predictability on travel speed: the road segment associated with intermediate average travel speed is most difficult to be predicted. We also explore the possibility of recovering the traffic condition of an inaccessible segment from its adjacent segments with respect to limited observability. The highly predictable traffic patterns in spite of the heterogeneity of drivers'' behaviors and the variability of their origins and destinations enables development of accurate predictive models for eventually devising practical strategies to mitigate urban road congestion.  相似文献   

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