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OBJECTIVE: To explore the reproductive pattern of women in rural Vietnam in relation to the existing family planning policies and laws. DESIGN: Cross sectional survey with question-naires on reproductive history. SETTING: Tien Hai, a district in Red River Delta area, where the population density is one of the highest in Vietnam. SUBJECTS: 1132 women who had at least one child under 5 years of age in April 1992. MAIN OUTCOME MEASURES: Birth spacing and probability of having a third child. RESULTS: The mean age at first birth was 22.2 years. The average spacing between the first and the second child was 2.6 years. Mothers with a lower educational level, farmers, and women belonging to the Catholic religion had shorter spacing between the first and second child and also a higher probability of having a third child. In addition, women who had no sons or who had lost a previous child were more likely to have a third child. CONCLUSION: Most families do not adhere to the official family planning policy, which was introduced in 1988, stipulating that each couple should have a maximum of two children with 3-5 years'' spacing in between. More consideration should be given to family planning needs and perceptions of the population, supporting the woman to be in control of her fertility. This may imply improved contraceptive services and better consideration of sex issues and cultural differences as well as improved social support for elderly people.  相似文献   

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Carrel M  Wan XF  Nguyen T  Emch M 《EcoHealth》2012,9(1):60-69
Locating areas where genetic change is inhibited can illuminate underlying processes that drive evolution of pathogens. The persistence of highly pathogenic H5N1 avian influenza in Vietnam since 2003, and the continuous molecular evolution of Vietnamese avian influenza viruses, indicates that local environmental factors are supportive not only of incidence but also of viral adaptation. This article explores whether gene flow is constant across Vietnam, or whether there exist boundary areas where gene flow exhibits discontinuity. Using a dataset of 125 highly pathogenic H5N1 avian influenza viruses, principal components analysis and wombling analysis are used to indicate the location, magnitude, and statistical significance of genetic boundaries. Results show that a small number of geographically minor boundaries to gene flow in highly pathogenic H5N1 avian influenza viruses exist in Vietnam, but that overall there is little division in genetic exchange. This suggests that differences in genetic characteristics of viruses from one region to another are not the result of barriers to H5N1 viral exchange in Vietnam, and that H5N1 avian influenza is able to spread relatively unimpeded across the country.  相似文献   

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BackgroundSeveral studies have indicated that universal health coverage (UHC) improves health service utilization and outcomes in countries. These studies, however, have primarily assessed UHC’s peacetime impact, limiting our understanding of UHC’s potential protective effects during public health crises such as the Coronavirus Disease 2019 (COVID-19) pandemic. We empirically explored whether countries’ progress toward UHC is associated with differential COVID-19 impacts on childhood immunization coverage.Methods and findingsUsing a quasi-experimental difference-in-difference (DiD) methodology, we quantified the relationship between UHC and childhood immunization coverage before and during the COVID-19 pandemic. The analysis considered 195 World Health Organization (WHO) member states and their ability to provision 12 out of 14 childhood vaccines between 2010 and 2020 as an outcome. We used the 2019 UHC Service Coverage Index (UHC SCI) to divide countries into a “high UHC index” group (UHC SCI ≥80) and the rest. All analyses included potential confounders including the calendar year, countries’ income group per the World Bank classification, countries’ geographical region as defined by WHO, and countries’ preparedness for an epidemic/pandemic as represented by the Global Health Security Index 2019. For robustness, we replicated the analysis using a lower cutoff value of 50 for the UHC index. A total of 20,230 country-year observations were included in the study. The DiD estimators indicated that countries with a high UHC index (UHC SCI ≥80, n = 35) had a 2.70% smaller reduction in childhood immunization coverage during the pandemic year of 2020 as compared to the countries with UHC index less than 80 (DiD coefficient 2.70; 95% CI: 0.75, 4.65; p-value = 0.007). This relationship, however, became statistically nonsignificant at the lower cutoff value of UHC SCI <50 (n = 60). The study’s primary limitation was scarce data availability, which restricted our ability to account for confounders and to test our hypothesis for other relevant outcomes.ConclusionsWe observed that countries with greater progress toward UHC were associated with significantly smaller declines in childhood immunization coverage during the pandemic. This identified association may potentially provide support for the importance of UHC in building health system resilience. Our findings strongly suggest that policymakers should continue to advocate for achieving UHC in coming years.

In a difference-in-difference study, Sooyoung Kim and colleagues study associations between progress toward universal healthcare coverage and childhood immunizations before and during the COVID-19 pandemic.  相似文献   

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Flowering plants (angiosperms) are the most prevalent and evolutionarily advanced group of plants. Success of these plants is owed to several unique evolutionary adaptations that aid in reproduction: the flower, the closed carpel, double fertilization, and the ultimate products of fertilization, seeds enclosed in the fruit. Angiosperms exhibit a vast array of reproductive strategies, including both asexual and sexual, the latter of which includes both self-fertilization and cross-fertilization. Asexual reproduction and self-fertilization are important reproductive strategies in a variety of situations, such as when mates are scarce or when the environment remains relatively stable. However, reproductive strategies promoting cross-fertilization are critical to angiosperm success, since they contribute to the creation of genetically diverse populations, which increase the probability that at least one individual in a population will survive given changing environmental conditions. The evolution of several physical and genetic barriers to self-fertilization or fertilization among closely related individuals is thus widespread in angiosperms. A major genetic barrier to self-fertilization is self-incompatibility (SI), which allows female reproductive cells to discriminate between "self" and "non-self" pollen, and specifically reject self pollen. Evidence for the importance of SI in angiosperm evolution lies in the highly diverse set of mechanisms used by various angiosperm families for recognition of self pollen tube development and preventing self-fertilization.  相似文献   

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This review discusses the barriers an enteric pathogen encounters when establishing an infection in the intestinal tract. There are potential barriers in the lumen that increase competition for nutrients and space. The role of mucus layer, and the antimicrobial peptides and secretory IgA sequestered within it, are also significant barriers. After overcoming these defences, the pathogen encounters the epithelial layer. This layer can be broken down into various protective components including enterocytes, Paneth cells, goblet cells, M cells and pathogen recognition receptors. Collectively, these intestinal defences constitute significant barriers that pathogens must overcome to successfully colonize this important mucosal surface.  相似文献   

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Microbiome engineering is increasingly being employed as a solution to challenges in health, agriculture, and climate. Often manipulation involves inoculation of new microbes designed to improve function into a preexisting microbial community. Despite, increased efforts in microbiome engineering inoculants frequently fail to establish and/or confer long-lasting modifications on ecosystem function. We posit that one underlying cause of these shortfalls is the failure to consider barriers to organism establishment. This is a key challenge and focus of macroecology research, specifically invasion biology and restoration ecology. We adopt a framework from invasion biology that summarizes establishment barriers in three categories: (1) propagule pressure, (2) environmental filtering, and (3) biotic interactions factors. We suggest that biotic interactions is the most neglected factor in microbiome engineering research, and we recommend a number of actions to accelerate engineering solutions.Subject terms: Community ecology, Microbial ecology

Microbiome engineering is a rapidly evolving frontier for solutions to improve human health, agricultural productivity, and climate management. Microbiome engineering seeks to improve the function of an ecosystem by manipulating the composition of microbes. Two major challenges for successful microbiome engineering are (1) the design of a microbiome with improved function and (2) the establishment of an improved microbiome in a recipient system of interest. While multiple articles and reviews have addressed functional design [13], microbiome establishment has received less attention. Here, we propose a strategy to improve microbiome engineering by focusing on microbial establishment and leveraging insights from macrobial ecology.Two general engineering strategies are to manipulate indigenous microbes [4] or to introduce new members [5]. The latter involves the design and delivery of inoculants (a.k.a., probiotics in medical and agricultural arenas) and is a rapidly growing biotechnology sector. In their most general form, both strategies have been practiced crudely for thousands of years in human health [6] and agriculture [7]. However, despite current technical advances, inoculants frequently still fail to establish or confer long-lasting (months to years) modifications to ecosystem function [8]. We argue that this repeated failure is in part driven by lack of emphasis on establishment of inoculants.The problem of organism establishment in recipient ecosystems is not unique to microbiome engineering; it has roots in macrobiology, particularly invasion biology and restoration ecology. We propose that adopting a cross-disciplinary conceptual framework to identify barriers to organism establishment, and then prioritizing these barriers through targeted research will accelerate successful microbiome engineering. In addition, recognizing differences in terminology and experimental design within and across disciplines will facilitate research integration across diverse ecosystems and scales. The components of a more holistic strategy are discussed below.  相似文献   

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Emerging studies have revealed new roles for the neural extracellular matrix in neuropathologies. The structure of this matrix is unusual and uniquely enriched in chondroitin sulfate proteoglycans, particularly those of the lectican family. Historically, lecticans have attracted considerable interest in the normal and injured brain for their prominent roles as inhibitors of cellular motility, neurite extension and synaptic plasticity. However, these molecules are structurally heterogeneous, have distinct expression patterns and mediate unique interactions, suggesting that they might have other functions in addition to their traditional role as chemorepulsants. Here, we review recent work demonstrating unique modifications and structural microheterogeneity of the lecticans in the diseased CNS, which might relate to novel roles of these molecules in neuropathologies.  相似文献   

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Despite the availability of cancer susceptibility testing, little information exists regarding physicians' selection and referral of eligible patients. This study provides insight into whom, why, and when physicians refer for cancer genetics evaluation, as well as their comfort level within this role. Eighty-two physicians (51 primary care, 15 gynecology, 11 surgery and 5 oncology) completed a survey (response rate: 34%) regarding cancer genetics referral practices. Of these, 59% reported an awareness of the hospital's cancer genetics program. Program awareness was greater among oncologists, surgeons, and gynecologists than among primary care physicians (p < 0.0001). Patients were referred for enhanced risk assessment (88%), improved medical management (85%), and concern for family members (83%). Patient eligibility was based on family cancer history (96%), patient cancer history (83%), and patient request (73%). Patients were not referred mainly due to patient disinterest (54%) or physician concern about either insurance coverage (44%) or insurance discrimination (31%). Primary care physicians were less comfortable with identifying patients for referral (p < 0.001) and with discussing genetics (p < 0.002) than specialists. The largest barriers to referral were lack of program awareness and limited knowledge regarding patient eligibility, improved insurance coverage, and antidiscrimination legislation. Physician-targeted marketing and education may improve the referral process.  相似文献   

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Barriers to polyspermy (fertilization of a female gamete by more than one sperm) are essential to successful reproduction in a wide range of organisms including mammals, echinoderms, fish, molluscs, and algae. In animals and fucoid algae, polyspermy results in early death of the zygote due to transmission of extra centrioles from the sperm and consequent disruptions to the mitotic spindle. Accordingly, a variety of mechanisms have evolved to prevent penetration of an egg by more than one sperm, or more than one sperm nucleus from fusing with an egg nucleus. The evolution of internal fertilization has also provided an opportunity to limit the number of sperm that gain access to each egg, as occurs in the mammalian female reproductive tract. Polyspermy and polyspermy barriers in plants have received much less attention. Plants lack centrioles and therefore, polyspermy would not be expected to cause lethal aberrant spindle organization. However, we find evidence from cytological, genetic and in vitro fertilization studies for polyspermy barriers in plants. Angiosperms, like mammals, are internally fertilized, and exert a high level of control over the number of sperm that have access to each female gamete. In particular, regulation of pollen tube growth ensures that in general only two sperm enter each embryo sac, where one fertilizes the egg and the other the central cell. Despite this 1:1 ratio of sperm to gametes within the embryo sac, angiosperms still require a mechanism to ensure that each female gamete is fertilized by one and only one sperm. Here, we present evidence suggesting that a polyspermy block on the egg may be part of the mechanism that promotes faithful double fertilization.  相似文献   

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This article discusses the changes in Vietnamese cinema from the Socialist to the contemporary period from the viewpoint of gender representation. Under socialist conditions of cultural production, films were made by state-funded studios, with a clear mandate to provide the population with film material appropriate to the state's ideals. Since Doi moi (“Renovation”) in the late 1980s, Vietnam was opened up to market forces and cinematic practices have responded. Issues of gender have come into focus, and films exploring these themes have emerged from both state studios and private investors. Nevertheless conservative social values remain strong, and gender remains an area of dynamic uncertainty.  相似文献   

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