首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   15篇
  免费   0篇
  2022年   1篇
  2015年   2篇
  2014年   1篇
  2012年   1篇
  2011年   2篇
  2010年   3篇
  2009年   2篇
  2006年   2篇
  2004年   1篇
排序方式: 共有15条查询结果,搜索用时 15 毫秒
1.
EcoHealth - The majority of emerging and re-emerging infectious diseases in people are zoonotic. Despite substantial research in communities adjacent to protected areas with high levels of...  相似文献   
2.
Four anthocyanins, cyanidin 3-O-(2″-(5?-(E-p-coumaroyl)-β-apiofuranosyl)-β-xylopyranoside)-5-O-β-glucopyranoside, cyanidin 3-O-(2″-(5?-(E-p-coumaroyl)-β-apiofuranosyl)-β-xylopyranoside), cyanidin 3-O-(2″-(5?-(E-caffeoyl)-β-apiofuranosyl)-β-xylopyranoside) and cyanidin 3-O-(2″-(5?-(E-feroyl)-β-apiofuranosyl)-β-xylopyranoside) were isolated from leaves of African milk bush, (Synadeniumgrantii Hook, Euphorbiaceae) together with the known cyanidin 3-O-β-xylopyranoside-5-O-β-glucopyranoside and cyanidin 3-O-β-xyloside. The four former pigments are the first reported anthocyanins containing the monosaccharide apiose, and the three 5?-cinnamoyl derivative-2″-(β-apiosyl)-β-xyloside subunits have previously not been reported for any compound.  相似文献   
3.
Chimpanzees (Pan troglodytes) have hostile intergroup relations throughout most or all of their geographic range. Hostilities include aggressive encounters between members of neighboring communities during foraging and during patrols in which members of one community search for neighbors near territory boundaries. Attacks on neighbors involve coalitions of adult males, and are sometimes fatal. Targets include members of all age/sex classes, but the risk of lethal intergroup coalitionary aggression is highest for adult males and infants, and lowest for sexually swollen females. The best-supported adaptive explanation for such behavior is that fission-fusion sociality allows opportunities for low-cost attacks that, when successful, enhance the food supply for members of the attackers' community, improve survivorship, and increase female fertility. We add to the database on intergroup coalitionary aggression in chimpanzees by describing three fatal attacks on adult males, plus a fourth attack on an adult male and an attack on a juvenile that were almost certainly fatal. Observers saw four of these attacks and inferred the fifth from forensic and behavioral evidence. The attackers were males in two habituated, unprovisioned communities (Ngogo and Kanyawara) in Kibale National Park, Uganda. We also summarize data on other intercommunity attacks at Ngogo. Our observations are consistent with the "imbalance of power" hypothesis [Manson & Wrangham, Current Anthropology 32:369-390, 1991] and support the argument that lethal coalitionary intergroup aggression by male chimpanzees is part of an evolved behavioral strategy.  相似文献   
4.
The stable isotopes of nitrogen (δ15N) and carbon (δ13C) provide powerful tools for quantifying trophic relationships and carbon flow to consumers in food webs; however, the isotopic signatures of organisms vary within a lake. Assessment of carbon and nitrogen isotopic signatures in a suite of plants, invertebrates, and fishes in Lake Kyoga, indicated significant variation between two sites for δ13C (paired t = 6.305; df = 14, P < 0.001 and δ15N paired t = 1.292; df = 14; P < 0.05). The fish fauna in Bukungu was generally more 13C enriched (mean δ13C = –16.37 ± 1.64‰) than in Iyingo (mean δ13C = –20.80 ± 2.41‰) but more δ15N depleted (mean δ15N = 5.57 ± 0.71‰) than in Iyingo (mean δ15N = 6.92 ± 0.83‰). The simultaneous shifts in phytoplankton and consumer signatures confirmed phytoplankton as the major source of carbon for the food chain leading to fish. Limited sampling coverage within lakes may affect lake wide stable isotope signatures, and the same error is transferred into trophic position estimation. Consideration of potential intra‐lake spatial variability in isotope ratios and size is essential in evaluating the spatial and trophic structure of fish assemblages.  相似文献   
5.

Background

The Kagera region of north western Tanzania has a rich culture of traditional medicine use and practices. The dynamic inter-ethnic interactions of different people from the surrounding countries constitute a rich reservoir of herbal based healing practices. This study, the second on an ongoing series, reports on the medicinal plant species used in Katoro ward, Bukoba District, and tries to use the literature to establish proof of the therapeutic claims.

Methodology

Ethnomedical information was collected using Semi-structured interviews in Kyamlaile and Kashaba villages of Katoro, and in roadside bushes on the way from Katoro to Bukoba through Kyaka. Data collected included the common/local names of the plants, parts used, the diseases treated, methods of preparation, dosage, frequency and duration of treatments. Information on toxicity and antidote were also collected. Literature was consulted to get corroborative information on similar ethnomedical claims and proven biological activities of the plants.

Results

Thirty three (33) plant species for treatement of 13 different disease categories were documented. The most frequently treated diseases were those categorized as specific diseases/conditions (23.8% of all remedies) while eye diseases were the least treated using medicinal plants (1.5% of all remedies). Literature reports support 47% of the claims including proven anti-malarial, anti-microbial and anti-inflammatory activity or similar ethnomedical uses. Leaves were the most frequently used plant part (20 species) followed by roots (13 species) while making of decoctions, pounding, squeezing, making infusions, burning and grinding to powder were the most common methods used to prepare a majority of the therapies.

Conclusion

Therapeutic claims made on plants used in traditional medicine in Katoro ward of Bukoba district are well supported by literature, with 47% of the claims having already been reported. This study further enhances the validity of plants used in traditional medicine in this region as resources that can be relied on to provide effective, accessible and affordable basic healthcare to the local communities. The plants documented also have the potential of being used in drug development and on farm domestication initiatives.  相似文献   
6.
7.
The introduction of Nile perch, Lates niloticus, to Lake Victoria, East Africa, interacted with eutrophication to cause a reorganization of the lake's food web and the extirpation of many endemic fishes. The Lake Kyoga satellite system lies downstream from Lake Victoria. It encompasses species‐rich lakes where Nile perch are absent or very rare, and low diversity lakes where L. niloticus is abundant. In 1999 we surveyed seven lakes in the Kyoga system using experimental monofilament gill nets (1/4–1 inches variable mesh). At Boston University we assessed δ15N signatures of epaxial muscle from subsamples of the catch (n = 361). These signatures are often highly correlated with the near‐term mean realized trophic position of an individual organism. A neural network analysis of fish length, species name, trophic level, and lake of origin fish explained 94% of the sample variance in δ15N. We analysed statistical patterns in these signatures at a number of spatial scales. The relationship between trophic level and δ15N varied greatly among lakes. Higher diversity perch‐free lakes had greater variance in δ15N values and fish lengths than lower diversity Nile perch lakes, suggesting an important relationship between species diversity and functional diversity. Against expectations, lake size was negatively correlated with δ15N. Patterns in stable isotope signatures indicated that Nile perch lakes have shorter food chains than perch‐free lakes. The results throw up two management problems for the Kyoga system. Impacted lakes need to be studied to understand and ameliorate the community‐level effects of Nile perch introduction, whereas the species‐rich nonperch lakes, which harbour a large proportion of the remaining diversity of regionally endemic taxa, are in need of conservation planning.  相似文献   
8.

Rationale

The diagnosis of latent tuberculosis (TB) infection (LTBI) is complicated by the absence of a gold standard. Discordance between tuberculin skin tests (TST) and interferon gamma release assays (IGRA) occurs in 10–20% of individuals, but the underlying mechanisms are poorly understood.

Methods

We analyzed data from a prospective household contact study that included cough aerosol culture results from index cases, environmental and contact factors. We assessed contacts for LTBI using TST and IGRA at baseline and six weeks. We examined TST/IGRA discordance in qualitative and quantitative analyses, and used multivariable logistic regression analysis with generalized estimating equations to analyze predictors of discordance.

Measurements and Results

We included 96 TB patients and 384 contacts. Discordance decreased from 15% at baseline to 8% by six weeks. In adjusted analyses, discordance was related to less crowding (p = 0.004), non-cavitary disease (OR 1.41, 95% CI: 1.02–1.96; p = 0.03), and marginally with BCG vaccination in contacts (OR 1.40, 95% CI: 0.99–1.98, p = 0.06).

Conclusions

We observed significant individual variability and temporal dynamism in TST and IGRA results in household contacts of pulmonary TB cases. Discordance was associated with a less intense infectious exposure, and marginally associated with a BCG-mediated delay in IGRA conversion. Cough aerosols provide an additional dimension to the assessment of infectiousness and risk of infection in contacts.  相似文献   
9.

Background

Urogenital schistosomiasis, caused by infection with Schistosoma haematobium, is widespread and causes substantial morbidity on the African continent. The infection has been suggested as an unrecognized risk factor for incident HIV infection. Current guidelines recommend preventive chemotherapy, using praziquantel as a public health tool, to avert morbidity due to schistosomiasis. In individuals of reproductive age, urogenital schistosomiasis remains highly prevalent and, likely, underdiagnosed. This comprehensive literature review was undertaken to examine the evidence for a cause-effect relationship between urogenital schistosomiasis and HIV/AIDS. The review aims to support discussions of urogenital schistosomiasis as a neglected yet urgent public health challenge.

Methodology/Principal Findings

We conducted a systematic search of the literature including online databases, clinical guidelines, and current medical textbooks. We describe plausible local and systemic mechanisms by which Schistosoma haematobium infection could increase the risk of HIV acquisition in both women and men. We also detail the effects of S. haematobium infection on the progression and transmissibility of HIV in co-infected individuals. We briefly summarize available evidence on the immunomodulatory effects of chronic schistosomiasis and the implications this might have for populations at high risk of both schistosomiasis and HIV.

Conclusions/Significance

Studies support the hypothesis that urogenital schistosomiasis in women and men constitutes a significant risk factor for HIV acquisition due both to local genital tract and global immunological effects. In those who become HIV-infected, schistosomal co-infection may accelerate HIV disease progression and facilitate viral transmission to sexual partners. Establishing effective prevention strategies using praziquantel, including better definition of treatment age, duration, and frequency of treatment for urogenital schistosomiasis, is an important public health priority. Our findings call attention to this pressing yet neglected public health issue and the potential added benefit of scaling up coverage of schistosomal treatment for populations in whom HIV infection is prevalent.  相似文献   
10.

Background

Malaria is the leading cause of morbidity and mortality in post-conflict Burundi. To counter the increasing challenge of anti-malarial drug resistance and improve highly effective treatment Burundi adopted artesunate-amodiaquine (AS-AQ) as first-line treatment for uncomplicated Plasmodium falciparum malaria and oral quinine as second-line treatment in its national treatment policy in 2003. Uptake of this policy in the public, private and non-governmental (NGO) retail market sectors of Burundi is relatively unknown. This study was conducted to evaluate access to national policy recommended anti-malarials.

Methods

Adapting a standardized methodology developed by Health Action International/World Health Organization (HAI/WHO), a cross-sectional survey of 70 (24 public, 36 private, and 10 NGO) medicine outlets was conducted in three regions of Burundi, representing different levels of transmission of malaria. The availability on day of the survey, the median prices, and affordability (in terms of number of days' wages to purchase treatment) of AS-AQ, quinine and other anti-malarials were calculated.

Results

Anti-malarials were stocked in all outlets surveyed. AS-AQ was available in 87.5%, 33.3%, and 90% of public, private, and NGO retail outlets, respectively. Quinine was the most common anti-malarial found in all outlet types. Non-policy recommended anti-malarials were mainly found in the private outlets (38.9%) compared to public (4.2%) and NGO (0%) outlets. The median price of a course of AS-AQ was US$0.16 (200 Burundi Francs, FBu) for the public and NGO markets, and 3.5-fold higher in the private sector (US$0.56 or 700 FBu). Quinine tablets were similarly priced in the public (US$1.53 or 1,892.50 FBu), private and NGO sectors (both US$1.61 or 2,000 FBu). Non-policy anti-malarials were priced 50-fold higher than the price of AS-AQ in the public sector. A course of AS-AQ was affordable at 0.4 of a day's wage in the public and NGO sectors, whereas, it was equivalent to 1.5 days worth of wages in the private sector.

Conclusions

AS-AQ was widely available and affordable in the public and NGO markets of hard-to-reach post-conflict communities in Burundi. However greater accessibility and affordability of policy recommended anti-malarials in the private market sector is needed to improve country-wide policy uptake.
  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号