全文获取类型
收费全文 | 118篇 |
免费 | 5篇 |
专业分类
123篇 |
出版年
2023年 | 1篇 |
2022年 | 7篇 |
2021年 | 10篇 |
2020年 | 4篇 |
2019年 | 2篇 |
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 12篇 |
2014年 | 5篇 |
2013年 | 9篇 |
2012年 | 15篇 |
2011年 | 6篇 |
2010年 | 3篇 |
2009年 | 1篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2006年 | 3篇 |
2005年 | 1篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 3篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有123条查询结果,搜索用时 66 毫秒
11.
Dereje Tesfaye Peter J. Fashing Afework Bekele Addisu Mekonnen Anagaw Atickem 《International journal of primatology》2013,34(3):615-640
Comparisons of the behavior and ecology of primates living in intact and fragmented forest are critical to the development of conservation strategies for the many primate taxa threatened by habitat loss. From July 2009 to April 2010, we investigated the habitat use, ranging behavior, and diet of two groups of Boutourlini’s blue monkeys (Cercopithecus mitis boutourlinii), a subspecies endemic to western Ethiopia, whose habitats had experienced different levels of disturbance at Jibat Forest. Forest Group occupied primarily continuous tree-dominated forest with little human disturbance whereas Fragment Group inhabited a heavily degraded 2- to 3-km2 forest fragment nearly surrounded by farmland and connected tenuously to the continuous forest by a narrow corridor of riverine forest. Mean daily path lengths for both groups were nearly identical (Forest Group: 799 m; Fragment Group: 783 m) and exhibited little seasonal variability. The mean home range areas of Forest Group and Fragment Group were 72.0 and 61.2 ha, respectively. Forest Group (N?=?2232 feeding records) fed mostly on fruits (52.5 %), though they also ate animal prey (14.7 %), young leaves (11.1 %), shoots (8.7 %), and flowers (7.3 %). In contrast, fruits accounted for only 17.0 % of Fragment Group’s diet (N?=?2903 feeding records), with shoots (29.8 %), young leaves (17.1 %), animal prey (13.1 %), seeds (9.6 %), and flowers (6.8 %) also making substantial contributions to their diet. Only Fragment Group engaged in crop raiding, consuming seeds from barley and wheat extensively (33–41 % of diet) during 2 mo. Fragment Group (N?=?33) ate more plant species than Forest Group (N?=?24), though both groups exploited a small number of plant species relative to other subspecies of blue monkeys. Our study revealed that, like most other blue monkey subspecies, Boutourlini’s blue monkeys are quite flexible in the habitats they occupy as well as in their foraging habits. Despite this ecological flexibility, the long-term conservation of Boutourlini’s blue monkey is far from assured given its limited distribution, the rapidly growing human population, and the high rates of forest clearance in western Ethiopia. 相似文献
12.
Zoonotic transmission of tuberculosis between pastoralists and their livestock in South-East Ethiopia 总被引:2,自引:0,他引:2
Gumi B Schelling E Berg S Firdessa R Erenso G Mekonnen W Hailu E Melese E Hussein J Aseffa A Zinsstag J 《EcoHealth》2012,9(2):139-149
Despite huge global efforts in tuberculosis (TB) control, pastoral areas remain under-investigated. During two years sputum and fine needle aspirate (FNA) specimens were collected from 260 Ethiopian pastoralists of Oromia and Somali Regional States with suspected pulmonary TB and from 32 cases with suspected TB lymphadenitis. In parallel, 207 suspected tuberculous lesions were collected from cattle, camels and goats at abattoirs. All specimens were processed and cultured for mycobacteria; samples with acid-fast stained bacilli (AFB) were further characterized by molecular methods including genus and deletion typing as well as spoligotyping. Non-tuberculous mycobacteria (NTM) were sequenced at the 16S rDNA locus. Culturing of AFB from human sputum and FNA samples gave a yield of 174 (67%) and 9 (28%) isolates, respectively. Molecular typing was performed on 173 of these isolates and 160 were confirmed as Mycobacterium tuberculosis, three as M. bovis, and the remaining 10 were typed as NTMs. Similarly, 48 AFB isolates (23%) yielded from tuberculous lesions of livestock, of which 39 were molecular typed, including 24 M. bovis and 4 NTMs from cattle, 1 M. tuberculosis and 1 NTM from camels and 9 NTMs from goats. Isolation of M. bovis from humans and M. tuberculosis from livestock suggests transmission between livestock and humans in the pastoral areas of South-East Ethiopia. 相似文献
13.
Amplified ribosomal DNA restriction analysis in the differentiation of related species of mycobacteria 总被引:1,自引:0,他引:1
Kurabachew M Enger Ø Sandaa RA Lemma E Bjorvatn B 《Journal of microbiological methods》2003,55(1):83-90
This study explores the potential of the amplified ribosomal DNA restriction analysis (ARDRA) for intra- and interspecies identification of the genus Mycobacteria. A set of primers was used to amplify part of the 16S and 23S rDNA as well as the 16S-23S rDNA spacer from 121 isolates belonging to 13 different mycobacterial species. Restriction analysis was carried out with five different restriction enzymes, namely CfoI, HaeIII, RsaI, MspI and TaqI. Restriction digestion of the PCR product using CfoI enabled differentiation between 9 of the 13 mycobacterial species, whereas the remaining four enzymes differentiated between 7 of these 13 species. None of the five enzymes distinguished between different isolates of Mycobacterium tuberculosis or between species within the M. tuberculosis complex i.e., M. tuberculosis, M. bovis, M. bovis BCG and M. africanum. Although ARDRA analysis of the 16S-23S rDNA does not seem to have a potential for intraspecies differentiation, it has proven to be a rapid and technically relatively simple method to recognise strains belonging to the M. tuberculosis complex as well as to identify mycobacterial species outside this complex. 相似文献
14.
Hershkovitz I Donoghue HD Minnikin DE Besra GS Lee OY Gernaey AM Galili E Eshed V Greenblatt CL Lemma E Bar-Gal GK Spigelman M 《PloS one》2008,3(10):e3426
Background
Mycobacterium tuberculosis is the principal etiologic agent of human tuberculosis. It has no environmental reservoir and is believed to have co-evolved with its host over millennia. This is supported by skeletal evidence of the disease in early humans, and inferred from M. tuberculosis genomic analysis. Direct examination of ancient human remains for M. tuberculosis biomarkers should aid our understanding of the nature of prehistoric tuberculosis and the host/pathogen relationship.Methodology/Principal Findings
We used conventional PCR to examine bone samples with typical tuberculosis lesions from a woman and infant, who were buried together in the now submerged site of Atlit-Yam in the Eastern Mediterranean, dating from 9250-8160 years ago. Rigorous precautions were taken to prevent contamination, and independent centers were used to confirm authenticity of findings. DNA from five M tuberculosis genetic loci was detected and had characteristics consistent with extant genetic lineages. High performance liquid chromatography was used as an independent method of verification and it directly detected mycolic acid lipid biomarkers, specific for the M. tuberculosis complex.Conclusions/Significance
Human tuberculosis was confirmed by morphological and molecular methods in a population living in one of the first villages with evidence of agriculture and animal domestication. The widespread use of animals was not a source of infection but may have supported a denser human population that facilitated transmission of the tubercle bacillus. The similarity of the M. tuberculosis genetic signature with those of today gives support to the theory of a long-term co-existence of host and pathogen. 相似文献15.
Addisu Mekonnen Peter J. Fashing Afework Bekele Nils Chr. Stenseth 《American journal of primatology》2020,82(4):e23074
Primates inhabiting human-modified landscapes often exploit matrix habitat to supplement their diet with cultivated foods, at times resulting in economic losses and conflict with local people. Understanding human-nonhuman primate interactions and the attitudes and perceptions of local people towards crop feeding species are crucial to designing effective species-based management plans. Over a 12-month period, we used scan sampling to study the consumption of cultivated foods and matrix use patterns by two habituated groups of Bale monkeys (Chlorocebus djamdjamensis), Ethiopian-endemic bamboo specialists, in two forest fragments (Kokosa and Afursa) set amidst human settlements and farmland in the southern Ethiopian Highlands. Further, we conducted interviews with local people to document their attitudes and perceptions towards Bale monkeys at the two sites. We found that Bale monkeys at Kokosa, a more degraded habitat by most measures, consumed significantly more cultivated foods than their counterparts at Afursa. Moreover, Bale monkeys at Kokosa spent significantly more time in the matrix than in the forest habitat, while monkeys at Afursa spent significantly less time in the matrix than in the forest habitat. Not surprisingly, local people displayed a more negative attitude towards monkeys inhabiting Kokosa than those inhabiting Afursa. The differences in Bale monkey cultivated food consumption and matrix use patterns—as well as in local people's attitudes and perceptions towards Bale monkeys—between Kokosa and Afursa are probably associated with differences in habitat structure, degree of habitat alteration, and land-use practices between the sites. We conclude that to ensure long-term coexistence between Bale monkeys and local people in human-modified landscapes, it is vital to incorporate nearby matrix habitats into management plans and to work closely with local communities to develop effective nonlethal crop protection strategies, thereby reducing the likelihood of negative interactions between Bale monkeys and humans. 相似文献
16.
Tadesse Melaku Abegaz Akshaya Srikanth Bhagavathula Eyob Alemayehu Gebreyohannes Alemayehu B. Mekonnen Tamrat Befekadu Abebe 《BMC cardiovascular disorders》2017,17(1):291
Background
Despite advances in medical knowledge, technology and antimicrobial therapy, infective endocarditis (IE) is still associated with devastating outcomes. No reviews have yet assessed the outcomes of IE patients undergoing short- and long-term outcome evaluation, such as all-cause mortality and IE-related complications. We conducted a systematic review and meta-analysis to examine the short- and long-term mortality, as well as IE-related complications in patients with definite IE.Methods
A computerized systematic literature search was carried out in PubMed, Scopus and Google Scholar from 2000 to August, 2016. Included studies were published studies in English that assessed short-and long-term mortality for adult IE patients. Pooled estimations with 95% confidence interval (CI) were calculated with DerSimonian-Laird (DL) random-effects model. Sensitivity and subgroup analyses were also performed. Publication bias was evaluated using inspection of funnel plots and statistical tests.Results
Twenty five observational studies (retrospective, 14; prospective, 11) including 22,382 patients were identified. The overall pooled mortality estimates for IE patients who underwent short- and long-term follow-up were 20% (95% CI: 18.0–23.0, P?<?0.01) and 37% (95% CI: 27.0–48.0, P?<?0.01), respectively. The pooled prevalence of cardiac complications in patients with IE was found to be 39% (95%CI: 32.0–46.0) while septic embolism and renal complications accounted for 25% (95% CI: 20.0–31) and 19% (95% CI: 14.0–25.0) (all P?<?0.01), respectively.Conclusion
Irrespective of the follow-up period, a significantly higher mortality rate was reported in IE patients, and the burden of IE-related complications were immense. Further research is needed to assess the determinants of overall mortality in IE patients, as well as well-designed observational studies to conform our results.17.
Daniel Fitamo Seyoum Leta Gurja Belay Bekele Lemma Mats Olsson 《Soil & Sediment Contamination》2011,20(7):745-766
Irrigation with untreated wastewater from several industrial, commercial, and domestic discharges for decades caused accumulation of various heavy metals and metalloids in soils along the Akaki River in Ethiopia. Assessment of environmental threats and the potential phytoremediation of the soils require understanding of the toxic elements’ uptake and distribution in plant parts. Hence, a greenhouse study was performed to examine the phytoavailability and distribution of Cr, Ni, Co, Cu, Zn, Cd, Pb, Hg, Se, V, and As in forage grasses: Oat (Avena sativa), Rhodes grass (Chloris gayana), Setaria (Setaria sphacelata), and the legumes Alfalfa (Medicago sativa) and Desmodium (Desmodium unicinatum). The average contents of Cr, Ni, Co, Cu, Zn, Pb, Hg, Se, and V in the plants were generally higher than the background levels for forage grasses/legumes, and some of these elements were in the phytotoxic range. Root bioconcentration factor (BCF = root to soil concentration ratio) > 1 was observed for Cu (Oat, Rhodes, Desmodium, and Setaria: Fluvisol), Zn (Setaria: Fluvisol), Cd (Rhodes: Fluvisol; Setaria from both soils) and Hg (Oat and Alfalfa: Fluvisol). Alfalfa and Desmodium displayed translocation factor > 1 (TF = shoot to root concentration ratio) for most heavy metals. Most heavy metals/metalloids may pose a health threat to humans and stock via introduction to the food chain. The plant factors (species and plant part), soil factors (soil type, soil fractions, pH, and CEC), and their interactions significantly (p < 0.05) influenced plant heavy metal and metalloid levels. However, the role of plant part and species emerged as the most important on heavy metal uptake, translocation, sequestration, and ultimately transfer to the food chain. Accordingly, the uptake and distribution of heavy metals/metalloids in the plants reflect the potential environmental and health hazards attributable to the use of fodder grasses, legumes, and cultivation of vegetables in soils with polymetallic and metalloid contamination. 相似文献
18.
Susan F Sommerlad John M Morton Mekonnen Haile-Mariam Isobel Johnstone Jennifer M Seddon Caroline A O’Leary 《BMC veterinary research》2012,8(1):1-16
Background
Congenital hereditary sensorineural deafness (CHSD) occurs in many dog breeds, including Australian Cattle Dogs. In some breeds, CHSD is associated with a lack of cochlear melanocytes in the stria vascularis, certain coat characteristics, and potentially, abnormalities in neuroepithelial pigment production. This study investigates phenotypic markers for CHSD in 899 Australian Cattle Dogs.Results
Auditory function was tested in 899 Australian Cattle Dogs in family groups using brainstem auditory evoked response testing. Coat colour and patterns, facial and body markings, gender and parental hearing status were recorded. Deafness prevalence among all 899 dogs was 10.8% with 7.5% unilaterally deaf, and 3.3% bilaterally deaf, and amongst pups from completely tested litters (n = 696) was 11.1%, with 7.5% unilaterally deaf, and 3.6% bilaterally deaf. Univariable and multivariable analyses revealed a negative association between deafness and bilateral facial masks (odds ratio 0.2; P ?? 0.001). Using multivariable logistic animal modelling, the risk of deafness was lower in dogs with pigmented body spots (odds ratio 0.4; P = 0.050). No significant associations were found between deafness and coat colour. Within unilaterally deaf dogs with unilateral facial masks, no association was observed between the side of deafness and side of mask. The side of unilateral deafness was not significantly clustered amongst unilaterally deaf dogs from the same litter. Females were at increased risk of deafness (odds ratio from a logistic animal model 1.9; P = 0.034) after adjusting for any confounding by mask type and pigmented body spots.Conclusions
Australian Cattle Dogs suffer from CHSD, and this disease is more common in dogs with mask-free faces, and in those without pigmented body patches. In unilaterally deaf dogs with unilateral masks, the lack of observed association between side of deafness and side of mask suggests that if CHSD is due to defects in molecular pigment pathways, the molecular control of embryonic melanoblast migration from ectoderm to skin differs from control of migration from ectoderm to cochlea. In Australian Cattle Dogs, CHSD may be more common in females. 相似文献19.
20.
Population ecology of the giant forest hog,Hylochoerus meinertzhageni in Chebera Churchura National Park,Ethiopia 下载免费PDF全文
Aemro Mekonnen Afework Bekele Mundanthra Balakrishnan 《African Journal of Ecology》2018,56(2):272-278
Population, feeding habit, distribution and activity patterns of the giant forest hog (Hylochoerus meinertzhageni) were studied in Chebera Churchura National Park (CCNP), Ethiopia, using line transect sample counts. Population estimate of the hogs was 845 individuals. Among the counted individuals, 42.4% were males and 57.6% were females. Among them, 32.8% were adults, 26.9% were subadults, and 40.3% were piglets. Large sounders of up to 20 individuals were seen during the wet season. They were seen in all habitat types in CCNP with higher abundance in the riverine vegetation. Availability of food, green vegetation cover and water were factors governing distribution of forest hogs in the study area. Grass was the major food item of the hogs (90%), mainly of Panicum sp., Acalypha psilostachya, Cissapelos rigidifolia, Psilotrichum gnaphalobryum and Abutilon ceclii. Feeding was the major activity for which 49.7% of the active daytime was used. Resting (lying down, standing and wallowing) was the next major activity, for which they spent 38.8% of the daytime, followed by other activities (11.5%). Morning and late afternoon activity peaks were more intensive during the dry season. This female‐biased giant forest hog population is expected to sustain in CCNP. 相似文献