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1.
《CMAJ》1921,11(5):365-366
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2.
Alvergne A  Gurmu E  Gibson MA  Mace R 《PloS one》2011,6(7):e22515
Socio-economic development has proven to be insufficient to explain the time and pace of the human demographic transition. Shifts to low fertility norms have thus been thought to result from social diffusion, yet to date, micro-level studies are limited and are often unable to disentangle the effect of social transmission from that of extrinsic factors. We used data which included the first ever use of modern contraception among a population of over 900 women in four villages in rural Ethiopia, where contraceptive prevalence is still low (<20%). We investigated whether the time of adoption of modern contraception is predicted by (i) the proportion of ever-users/non ever-users within both women and their husbands' friendships networks and (ii) the geographic distance to contraceptive ever-users. Using a model comparison approach, we found that individual socio-demographic characteristics (e.g. parity, education) and a religious norm are the most likely explanatory factors of temporal and spatial patterns of contraceptive uptake, while the role of person-to-person contact through either friendship or spatial networks remains marginal. Our study has broad implications for understanding the processes that initiate transitions to low fertility and the uptake of birth control technologies in the developing world.  相似文献   

3.
Der Klippspringer (Oreotragus oreotragus) wurde in drei Gebieten in Athiopien beobachtet. Meist leben ein ♂ und ein bis zwei ♀♀ zusammen. Die Gruppe hat ein kleines Wohngebiet (etwa 8 ha), das sie gegen andere Gruppen verteidigt. Klippspringer fressen meist Gras und Blätter von Büschen. Klippspringer haben viele Feinde. Das ♂ steht meist Wache, während das ♀ gesichert frißt. Das ♀ führt Ortswechsel an. Die Jungen werden nach der Regenzeit im November geboren. Im folgenden Jahr verlassen die männlichen Jungen ihre elterliche Gruppe; die weiblichen Jungen bleiben länger darin, und einige paaren sich mit ihrem Vater. Stabile Paarbindungen werden als Anpassung an offene Landschaft gedeutet; das ♂ kann ♀♀ und Junge beschiitzen.  相似文献   

4.
Maternal mRNAs are translationally regulated during early development. Zar1 and its closely related homolog, Zar2, are both crucial in early development. Xenopus laevis Zygote arrest 2 (Zar2) binds to the Translational Control Sequence (TCS) in maternal mRNAs and regulates translation. The molecular mechanism of Zar1 has not been described. Here we report similarities and differences between Xenopus Zar1 and Zar2. Analysis of Zar sequences in vertebrates revealed two Zar family members with conserved, characteristic amino acid differences in the C-terminal domain. The presence of only two vertebrate Zar proteins was supported by analyzing Zar1 synteny. We propose that the criteria for naming Zar sequences are based on the characteristic amino acids and the chromosomal context. We also propose reclassification of some Zar sequences. We found that Zar1 is expressed throughout oogenesis and is stable during oocyte maturation. The N-terminal domain of Zar1 repressed translation of a reporter construct in immature oocytes. Both Zar1 and Zar2 bound to the TCS in the Wee1 and Mos 3′ UTRs using a zinc finger in the C-terminal domain. However, Zar1 had much higher affinity for RNA than Zar2. To show the functional significance of the conserved amino acid substitutions, these residues in Zar2 were mutated to those found in Zar1. We show that these residues contributed to the different RNA binding characteristics of Zar1 compared to Zar2. Our study shows that Zar proteins have generally similar molecular functions in the translational regulation of maternal mRNAs, but they may have different roles in early development.  相似文献   

5.

Background

IPT with or without concomitant administration of ART is a proven intervention to prevent tuberculosis among PLHIV. However, there are few data on the routine implementation of this intervention and its effectiveness in settings with limited resources.

Objectives

To measure the level of uptake and effectiveness of IPT in reducing tuberculosis incidence in a cohort of PLHIV enrolled into HIV care between 2007 and 2010 in five hospitals in southern Ethiopia.

Methods

A retrospective cohort analysis of electronic patient database was done. The independent effects of no intervention, “IPT-only,” “IPT-before-ART,” “IPT-and-ART started simultaneously,” “ART-only,” and “IPT-after-ART” on TB incidence were measured. Cox-proportional hazards regression was used to assess association of treatment categories with TB incidence.

Results

Of 7,097 patients, 867 were excluded because they were transferred-in; a further 823 (12%) were excluded from the study because they were either identified to have TB through screening (292 patients) or were on TB treatment (531). Among the remaining 5,407 patients observed, IPT had been initiated for 39% of eligible patients. Children, male sex, advanced disease, and those in Pre-ART were less likely to be initiated on IPT. The overall TB incidence was 2.6 per 100 person-years. As compared to those with no intervention, use of “IPT-only” (aHR = 0.36, 95% CI = 0.19–0.66) and “ART-only” (aHR = 0.32, 95% CI = 0.24–0.43) were associated with significant reduction in TB incidence rate. Combining ART and IPT had a more profound effect. Starting IPT-before-ART (aHR = 0.18, 95% CI = 0.08–0.42) or simultaneously with ART (aHR = 0.20, 95% CI = 0.10–0.42) provided further reduction of TB at ∼80%.

Conclusions

IPT was found to be effective in reducing TB incidence, independently and with concomitant ART, under programme conditions in resource-limited settings. The level of IPT provision and effectiveness in reducing TB was encouraging in the study setting. Scaling up and strengthening IPT service in addition to ART can have beneficial effect in reducing TB burden among PLHIV in settings with high TB/HIV burden.  相似文献   

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This study of immigrants’ integration in Israel centers on one major subjective parameter, namely the immigrant's identity. To explain it we explore a series of possible factors: demographic variables, economic status, and human and social capital characteristics. Three recent immigrant groups are examined: from Western countries, from the former Soviet Union (FSU), and from Ethiopia. These immigrants came to Israel during the last two decades from different societies, following different immigration circumstances and various motives.

The findings, based on the 2007 Ruppin survey data, point to the significant impact of the identity as perceived by veteran Israelis on the immigrants’ self-identity for the three groups under study. Also, different variables affect each of the immigrant groups. FSU immigrants behaved according to most of our hypotheses, whereas Western and Ethiopian immigrants did not. Findings are discussed in light of the debate on measuring and defining immigrants’ identity.  相似文献   

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Background

Cryptococcal disease is estimated to be responsible for significant mortality in Sub-Saharan Africa; however, only scarce epidemiology data exists. We sought to evaluate the prevalence of and risk factors for cryptococcal antigenemia in Ethiopia.

Methods

Consecutive adult HIV-infected patients from two public HIV clinics in Addis Ababa, Ethiopia were enrolled into the study. A CD4 count ≤200 cells/μl was required for study participation. Patients receiving anti-retroviral therapy (ART) were not excluded. A cryptococcal antigen test was performed for all patients along with an interview, physical exam, and medical chart abstraction. Logistic regression analysis was used to assess risk factors for cryptococcal antigenemia.

Results

369 HIV-infected patients were enrolled; mean CD4 123 cells/μl and 74% receiving ART. The overall prevalence of cryptococcal antigenemia was 8.4%; 11% in patients with a CD4 count <100 cells/μl, 8.9% with CD4 100 to 150 cells/μl and 5.7% with CD4150-200 cell/μl. 84% of patients with cryptococcal antigenemia were receiving ART. In multivariable analysis, increasing age, self reported fever, CD4 count <100 cells/μl, and site of screening were associated with an increased risk of cryptococcal antigenemia. No individual or combination of clinical symptoms had optimal sensitivity or specificity for cryptococcal antigenemia.

Conclusion

Cryptococcal antigenemia is high in Ethiopia and rapid scale up of screening programs is needed. Screening should be implemented for HIV-infected patients with low CD4 counts regardless of symptoms or receipt of ART. Further study into the effect of location and environment on cryptococcal disease is warranted.  相似文献   

12.
基因治疗是将外源性遗传物质通过多种方法转移到靶细胞中,用来治疗特定疾病。基因治疗对某些单基因遗传病有一次治愈的可能,或将成为未来治疗人类疾病的重要手段。但基因治疗仍存在诸多挑战,如长期的安全性和疗效数据、可及性以及监管等。从基因治疗的基本概念和历史出发,结合基因治疗产品的开发现状和未来,进行讨论。  相似文献   

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肿瘤严重威胁着人类健康,当前肿瘤传统的治疗方法有手术治疗、化疗、放疗和靶向药物治疗等。近年来,肿瘤免疫治疗,尤其是嵌合抗原受体(chimeric antigen receptor,CAR) T细胞免疫疗法在基础研究与临床应用中蓬勃发展,并在治疗血液系统恶性肿瘤方面取得了巨大成功。然而,大量研究显示,细胞免疫治疗后可出现不同程度的毒副反应,且部分患者缓解后再次复发。因此,了解细胞治疗面临的挑战与局限性,寻找解决的办法,对继续发挥细胞免疫疗法的潜能具有重要意义。本文就免疫细胞的CAR结构、病毒载体的选择、细胞治疗面临的挑战及前景进行综述。  相似文献   

15.
基因治疗是将外源性遗传物质通过多种方法转移到靶细胞中,用来治疗特定疾病。基因治疗对某些单基因遗传病有一次治愈的可能,或将成为未来治疗人类疾病的重要手段。但基因治疗仍存在诸多挑战,如长期的安全性和疗效数据、可及性以及监管等。从基因治疗的基本概念和历史出发,结合基因治疗产品的开发现状和未来,进行讨论。  相似文献   

16.
Under the conditions provided by the socialist system, the influence of the group upon the personality is manifested to a maximum degree. The principle of collectivism corresponds to the consciousness of Soviet people, which has developed on the basis of socialist relations and comradely collaboration. At the same time, under the conditions of our society the role of the personality is especially great, and it is no accident that it is particularly in Soviet medicine that the individualized approach to the patient is realized to the greatest degree.  相似文献   

17.
We analyze two large datasets from technological networks with location and social data: user location records from an online location-based social networking service, and anonymized telecommunications data from a European cellphone operator, in order to investigate the differences between individual and group behavior with respect to physical location. We discover agreements between the two datasets: firstly, that individuals are more likely to meet with one friend at a place they have not visited before, but tend to meet at familiar locations when with a larger group. We also find that groups of individuals are more likely to meet at places that their other friends have visited, and that the type of a place strongly affects the propensity for groups to meet there. These differences between group and solo mobility has potential technological applications, for example, in venue recommendation in location-based social networks.  相似文献   

18.
Access to seed is crucial for farming, though few studies investigate household-level access in the informal ‘farmer seed systems’ which still supply most seed in poor countries. This paper uses empirical data of seed exchange practices for sorghum in eastern Ethiopia to analyze how social relationships influence access to off-farm seed for a major crop. Seed shortfalls are common, and farmer–farmer exchange is important for providing locally-adapted seed to fill this gap, but access varies considerably among households, also affecting quantities supplied and terms of exchange. Preferred sources for off-farm seed (neighbors, government, market) also vary among farmers, reflecting agroecology and asset-ownership, but also differing access to these sources. Social network theories highlight the importance of reciprocal ties, and the cultural norms underpinning them, in accessing seed. These cultural norms are contested, with some claiming that commercial transactions are increasingly common. Implications for interventions supporting farmer seed systems, particularly emergency seed aid, are discussed in relation to the socially-mediated nature of seed access.
Shawn J. McGuireEmail:
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19.
The social organization of a group of wolves in a large outdoorenclosure was followed through several breeding seasons. Duringthe breeding season conflicts become more frequent and the socialhierarchy obvious. The more dominant animals restrict courtshipactivities by inferior wolves of their own sex. However, apparentlyas a correlate of their position, two alpha males have shownless mating activity than other males. Mate preferences exhibitedby animals of both sexes also limit the number of matings. Thepreferences appear related to the social hierarchy existingwhen an animal matures. Cultural transmission of social statusis suggested by some changes in ranking of wolves raised inthe woods at Brookfield. Temporary removal of the original alphamale and death of the original alpha female appear to have promotedchanges in social order and an increase in actual mating combinations.The probable consanguineous nature of wolf groups and facetsof the social behavior suggest that some form of group selectioncould be operative in the wild.  相似文献   

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