The effects of type of female circumcision on infertility and fertility in Sudan

This study explores the association between type of female circumcision and infertility and fertility in Sudan using the 1989-90 Demographic and Health Survey. It is hypothesized that women with either Pharaonic or Intermediate circumcision would have higher infertility and lower fertility compared with women with Sunna circumcision, and that uncircumcised women would have the lowest infertility and highest fertility of the three groups. This hypothesis, a widely held assumption, proved to be largely incorrect. Though women with Pharaonic or Intermediate circumcision did have a higher prevalence of primary infertility than uncircumcised women, women with Sunna circumcision had even lower rates of primary infertility compared with uncircumcised women. This pattern prevailed in multivariate models controlling for confounding variables, where women with Pharaonic or Intermediate circumcision had significantly higher primary infertility. Moreover, though women with Pharaonic or Intermediate circumcision also had the highest prevalence of secondary infertility, once confounding covariates were controlled in multivariate models, there was no significant difference among the three groups of women. With respect to fertility, the total fertility rate was 7.6 for women with Pharaonic or Intermediate circumcision, 8.1 for women with Sunna circumcision and 8.3 for uncircumcised women. Differences in fertility were found to be insignificant when covariates were controlled. The multivariate models were estimated using logistic regression. In conclusion, Pharaonic or Intermediate circumcision may be associated with higher primary infertility while there was no evidence suggesting that either secondary infertility or fertility was associated with a woman's circumcision status.     

Prevalence and spatial distribution characteristics of human echinococcosis in China

BackgroundEchinococcosis is a zoonotic parasitic disease caused by larval stages of cestodes belonging to the genus Echinococcus. The infection affects people’s health and safety as well as agropastoral sector. In China, human echinococcosis is a major public health burden, especially in western China. Echinococcosis affects people health as well as agricultural and pastoral economy. Therefore, it is important to understand the prevalence status and spatial distribution of human echinococcosis in order to advance our knowledge of basic information for prevention and control measures reinforcement.MethodsReport data on echinococcosis were collected in 370 counties in China in 2018 and were used to assess prevalence and spatial distribution. SPSS 21.0 was used to obtain the prevalence rate for CE and AE. For statistical analyses and mapping, all data were processed using SPSS 21.0 and ArcGIS 10.4, respectively. Chi-square test and Exact probability method were used to assess spatial autocorrelation and spatial clustering.ResultsA total of 47,278 cases of echinococcosis were recorded in 2018 in 370 endemic counties in China. The prevalence rate of human echinococcosis was 10.57 per 10,000. Analysis of the disease prevalence showed obvious spatial positive autocorrelation in globle spatial autocorrelation with two aggregation modes in local spatial autocorrelation, namely high-high and low-high aggregation areas. The high-high gathering areas were mainly concentrated in northern Tibet, western Qinghai, and Ganzi in the Tibetan Autonomous Region and in Sichuan. The low-high clusters were concentrated in Gamba, Kangma and Yadong counties of Tibet. In addition, spatial scanning analysis revealed two spatial clusters. One type of spatial clusters included 71 counties in Tibet Autonomous Region, 22 counties in Qinghai, 11 counties in Sichuan, three counties in Xinjiang Uygur Autonomous Region, two counties in Yunnan, and one county in Gansu. In the second category, six types of spatial clusters were observed in the counties of Xinjiang Uygur Autonomous Region, and the Qinghai, Gansu, and Sichuan Provinces.ConclusionThis study showed a serious prevalence of human echinococcosis with obvious spatial aggregation of the disease prevalence in China. The Qinghai-Tibet Plateau is the "hot spot" area of human echinococcosis in China. Findings from this study indicate that there is an urgent need of joint strategies to strengthen efforts for the prevention and control of echinococcosis in China, especially in the Qinghai-Tibet Plateau.     

Remote sensing monitoring upon the grass production in China

Using MODIS remote sensing data and ground truth data, a thorough investigation was conducted to monitor the productivity of grasslands in China for the year 2005. The Normalized Difference Vegetation Index (NDVI) was first computed from the MODIS data. Then the data from the NDVI images were used to correlate with the grass yield data from the ground sampling campaigns. Six regional models were accordingly established from the correlation for estimation of grass production in the six main types of steppe in China. The main results from the estimation could be summarized as follows: (1) High grass productivity in 2005 was obtained in the following 3 regions: the grassland covering Hulunbuir, Xilinhaote, and the western Daxing'anling, the region including the eastern Qinghai, the northwestern Sichuan and the mid-southern Gansu, and the northwestern Xinjiang region. (2) Total hay output from the grasslands in China amounted to 294213.86 thousand tons in 2005 with an average yield of 829.67 kg/hm2. (3) The following 7 provinces were the largest grass producers in China: Inner Mongolia, Qinghai, Xinjiang, Sichuan, Tibet, Heilongjiang and Gansu. For example, Inner Mongolia produced 60370.82 thousand tons of hay in 2005, and hence became the No. 1 grass producer of China. (4) Among the steppe types, the following 5 had the largest grass production: Alpine meadow, Temperate steppe, Low-land meadow, Temperate meadow steppe and Montane meadow with total production accounting for 62.2% in China. (5) Grass production of the entire China in August 2005 remained at the same level as that in August 2004. However, the situations of major grassland provinces were different: grass production in both Qinghai and Gansu in 2005 increased to 9.02% and 3.63%, respectively, when compared with that in 2004. The grass production in Inner Mongolia decreased by 3%, while the production in Tibet, Xinjiang and Sichuan remains unchanged when compared with that in 2004. These results were very important for grassland administration, pasture grazing and grassland ecosystem studies in China.     

Remote sensing monitoring upon the grass production in China

Using MODIS remote sensing data and ground truth data, a thorough investigation was conducted to monitor the productivity of grasslands in China for the year 2005. The Normalized Difference Vegetation Index (NDVI) was first computed from the MODIS data. Then the data from the NDVI images were used to correlate with the grass yield data from the ground sampling campaigns. Six regional models were accordingly established from the correlation for estimation of grass production in the six main types of steppe in China. The main results from the estimation could be summarized as follows: (1) High grass productivity in 2005 was obtained in the following 3 regions: the grassland covering Hulunbuir, Xilinhaote, and the western Daxing'anling, the region including the eastern Qinghai, the northwestern Sichuan and the mid-southern Gansu, and the northwestern Xinjiang region. (2) Total hay output from the grasslands in China amounted to 294213.86 thousand tons in 2005 with an average yield of 829.67 kg/hm2. (3) The following 7 provinces were the largest grass producers in China: Inner Mongolia, Qinghai, Xinjiang, Sichuan, Tibet, Heilongjiang and Gansu. For example, Inner Mongolia produced 60370.82 thousand tons of hay in 2005, and hence became the No. 1 grass producer of China. (4) Among the steppe types, the following 5 had the largest grass production: Alpine meadow, Temperate steppe, Low-land meadow, Temperate meadow steppe and Montane meadow with total production accounting for 62.2% in China. (5) Grass production of the entire China in August 2005 remained at the same level as that in August 2004. However, the situations of major grassland provinces were different: grass production in both Qinghai and Gansu in 2005 increased to 9.02% and 3.63%, respectively, when compared with that in 2004. The grass production in Inner Mongolia decreased by 3%, while the production in Tibet, Xinjiang and Sichuan remains unchanged when compared with that in 2004. These results were very important for grassland administration, pasture grazing and grassland ecosystem studies in China.     

中国草原产草量遥感监测

根据MODIS遥感数据和同期地面调查数据,对我国2005年草原产草量进行了系统估算。用MODIS数据计算全国草原的归一化植被指数NDVI,针对6个不同类型草原区建立了NDVI和地面样方的产草量之间的关系模型,用这些模型推算全国草原产草量分布。结论如下：（1）2005年我国草原有3个牧草高产中心,分别位于东北呼伦贝尔草原、锡林浩特草原和大兴安岭西麓;青海东部、四川西北部和甘肃中南部以及新疆西北部;（2）2005年全国草原干草总产量达到29421．39万t,平均单产达到829．67kg／hm^2干草;（3）2005年干草产量位列前7位的省区依次是内蒙古、青海、新疆、四川、西藏、黑龙江和甘肃;例如,内蒙古因草原面积大而成为我国第一大草原牧草生产省,2005年有6037．08万t干草;（4）总产草量位于前5位的草地类型依次为高寒草甸类、温性草原类、低地草甸类、温性草甸草原类与山地草甸类;（5）2005年8月份全国草原产草量与2004年同期相比总体持平;各草原大省的变化情况分别为：青海、甘肃2省区的草产量略有增加,青海增加了9．02％、甘肃增加了3．63％;内蒙古减少约3％;西藏、新疆和四川3省区基本与2004年同期持平。研究结果对我国草原监理、草原畜牧业发展和草地生态系统研究具有较大的参考价值。     

藏族的高原适应——西藏藏族生物人类学研究回顾

藏族生活在具有世界屋脊之称的青藏高原, 特殊的生态环境和特殊的文化背景造就了藏族特殊的适应高原缺氧机制, 引起了国内外学者的广泛关注和浓厚的研究兴趣。本文根据国内外数据库的文献并结合我们的研究工作, 从高原适应的角度回顾了30多年藏族人类学研究。回顾显示, 藏族由于长期生活在高原缺氧的环境中, 不仅形态和机能发生了适应性变化, 而且体成分也表现出相应的变化, 体现了形态、机能和体成分的统一。这些变化是长期进化形成的, 与安第斯山人等有明显不同, 就是在同一高原生活的西藏、青海、四川、甘肃和云南的藏族乃至尼泊尔和印度藏族的体质也表现出地域差异, 这些差异的产生是多种因素所致, 两个关键性的基因是导致两大高原人口高原适应机制不同的最主要的原因。     

Sub-clinical hypothyroidism in infertile Nigerian women with hyperprolactinaemia

Studies on the impact of subclinical hypothyroidism in infertility are scarce and this seeks to determine the proportion of infertile Nigerian women with hyperprolactinaemia that had subclinical hypothyroidism. Serum prolactin and thyroid stimulating hormone were determined using ELECSYS 1010 auto analyzer. Two hundred infertile women were evaluated and 67(33.7%) had hyperprolactinaemia. Subclinical hypothyroidism was observed in 14.9% of women with hyperprolactinaemia, 4.5% and 10.5% of women with primary and secondary infertility, while hyperprolactinaemia was observed in 29.9% and 70.1% in primary and secondary infertility respectively. Mean levels of thyroid stimulating hormone and prolactin were higher in secondary infertility than primary infertility. Subclinical hypothyroidism and hyperprolactinaemia were higher in secondary infertility than primary infertility. The ratio of proportions between hypothyroidism and hyperprolactinaemia was 1:7. Keywords: Sub clinical hypothyroidism, Hyperprolactinaemia, Primary infertility, Secondary infertility.     

Serological evidence that chlamydiae and mycoplasmas are involved in infertility of women

Women with a history of infertility for 2 or more years were examined by hysterosalpingography (HSG) and antibodies against Chlamydia trachomatis, Mycoplasma hominis and M. genitalium were measured by a microimmunofluorescence technique in sera obtained immediately before HSG. Of 45 women with abnormal HSG findings, 15 (33%) had antibodies to C. trachomatis and 16 (35.5%) to M. hominis. In contrast, of 61 women with normal HSG findings, only 8 (13%) and 7 (11.5%) had antibodies to these micro-organisms, respectively. Antibody against M. genitalium was found in 26 of the patients (20% abnormal HSG and 28% normal HSG), indicating the need for further investigation of the significance of this mycoplasma in female infertility. The present results do confirm, however, that C. trachomatis is an important cause of infertility in women and suggest strongly that M. hominis is implicated.     

Anticardiolipin antibodies in women with unexplained infertility

Concept of autoimmune basis of infertility is still controversial, particularly regarding the presence of non-organ specific autoantibodies. Non-organ specific anticardiolipin (aCL) and antithyroglobulin (TgAt) antibodies were detected in infertile women. Both partners were evaluated according to the criteria of The American Society for Reproductive Medicine. All the results were normal in cases of unexplained infertility. Antisperm antibodies (ASA) were determined by a mixed antiglobulin reaction (MAR) and the Kibrick agglutination assay, aCL by commercial ELISA, TgAt by commercial RIA. Fertile women had children. Subjects were grouped in fertile (n=27), infertile (n=65), and cases of unexplained infertility (n=42). In fertile women, aCL was below the negative cut-off value (100 %), while women with unexplained infertility were positive in 23.8 %. Anticardiolipin (aCL) antibodies were detected in 21.5 % of infertile patients, most of them with unexplained infertility (15.4 %). Other positive women had partners with ASA (4.6 %), or exhibited a negative postcoital test (1.5 %). In this study aCL were not detected in women with ASA. TgAt incidence was increased in infertile (20 %) and unexplained infertility group (21.4 %) compared to the fertile controls (18.5 %). Increased incidence of aCL and TgAt in infertile women supports the contention that these autoantibodies contribute to the infertility     

Value of bromocriptine in unexplained primary infertility: a double-blind controlled trial.

In a double-blind controlled study, 47 women with unexplained primary infertility were allocated at random to treatment with either bromocriptine 2.5 mg twice daily (24 patients) or placebo (23). Both groups showed a fall in serum prolactin concentrations but the reduction was much greater in the bromocriptine-treated group. Neither group showed a change in serum oestrogen or progesterone concentrations. Bromocriptine significantly reduced the duration of the follicular phase of the menstrual cycle but had no effect on the luteal phase. Five women conceived during treatment with placebo and seven during treatment with bromocriptine, but analysis of the cumulative conception rates showed no significant difference between the groups. The women who conceived were significantly younger and had a significantly shorter history of infertility than the women who did not conceive, but subtracting the number of years of infertility from age eliminated this difference. The results show that bromocriptine in the dose and duration of administration used in the trial is of no value in unexplained primary infertility.     

Depression and Altitude: Cross-Sectional Community-Based Study Among Elderly High-Altitude Residents in the Himalayan Regions

Suicide rates are higher at high altitudes, and some hypothesize that hypoxia is the cause. There may be a significant correlation between rates of depression and altitude, but little data exist outside the United States. The purpose of the present study is to conduct a survey of depression among the elderly highlanders in Asia. We enrolled 114 persons aged 60 years or older (mean, 69.2 ± 6.7 years; women, 58.8 %) in Domkhar (altitude, 3800 m), Ladakh, India and 173 ethnic Tibetans (mean, 66.5 ± 6.1 years; women, 61.3 %) in Yushu (altitude, 3700 m), Qinghai Province, China. The two-item Patient Health Questionnaire (PHQ-2) and the geriatric depression scale were administered. A psychiatrist interviewed the subjects who had a positive score on the PHQ-2. The results of the interview with the residents conducted by the specialist showed that two cases (1.8 %) from Domkhar and four (2.3 %) from Qinghai had depression. Despite the high altitude, the probability of depression was low in elderly highlander in Ladakh and Qinghai. Our finding seems to indicate that cultural factors such as religious outlook and social/family relationship inhibit the development of depression.     

Type 2 diabetes in Xinjiang Uygur autonomous region, China

Background

The aim of this study was to estimate the prevalence and distribution of type 2 diabetes and to determine the status of type 2 diabetes awareness, treatment, and control in Xinjiang, China. Our data came from the Cardiovascular Risk Survey (CRS) study designed to investigate the prevalence and risk factors for cardiovascular diseases in Xinjiang from October 2007 to March 2010. A total of 14 122 persons (5583 Hans, 4620 Uygurs, and 3919 Kazaks) completed the survey and examination. Diabetes was defined by the American Diabetes Association 2009 criteria.

Methodology/Principal Findings

Overall, 9.26% of the Han, 6.23% of the Uygur, and 3.65% of the Kazak adults aged ≥35 years had diabetes. Among diabetes patients, only 53.0% were aware of their blood glucose level, 26.7% were taking hypoglycemic agents, and 10.4% achieved blood glucose control in Han, 35.8% were aware of their blood glucose level, 7.3% were taking hypoglycemic agents, and 3.13% achieved blood glucose control in Uygur, and 23.8% were aware of their blood glucose level, 6.3% were taking hypoglycemic agents, and 1.4% achieved blood glucose control in Kazak, respectively.

Conclusions/Significance

Our results indicate that diabetes is highly prevalent in Xinjiang. The percentages of those with diabetes who are aware, treated, and controlled are unacceptably low. These results underscore the urgent need to develop national strategies to improve prevention, detection, and treatment of diabetes in Xinjiang, the west China.     

新疆维吾尔族2型糖尿病人群肠道中Faecalibacterium prausnitzii的定量研究

目的 定量检测新疆维吾尔族2型糖尿病（T2DM）和糖耐量正常（NGT）人群肠道中的普拉梭菌（Faecalibacterium prausnitzii）水平。方法 提取上述人群粪便细菌总DNA后,采用16S rDNA基因实时荧光定量PCR对普拉梭菌水平进行定量检测;运用Pearson分析普拉梭菌水平与研究对象的空腹血糖（FBG）、甘油三酯（TG）、总胆固醇（TC）、体重和体重指数（BMI）的相关性。结果 （1）16S rDNA基因实时定量PCR结果显示：与新疆维吾尔族NGT组相比,普拉梭菌水平在T2DM中较低（t=2.590,P=0.014）,差异有统计学意义。（2）新疆维吾尔族上述人群肠道中普拉梭菌水平与FBG呈负相关（r=‒0.434,P=0.012）,体重呈负相关（r=‒0.359,P=0.044）,TG呈负相关（r=‒0.410,P=0.034）。结论 Faecalibacterium prausnitzii水平在肠道中降低可能与2型糖尿病的发病有关,其机制需进一步研究探讨。     

新疆吐鲁番地区维吾尔族HLA-DQA1等位基因多态性研究

目的：探讨新疆吐鲁番地区维吾尔族HLA—DQA1等位基因多态性。方法：采用聚合酶链反应一序列特异性引物技术,检测107例新疆吐鲁番地区维吾尔族健康个体的HLA—DQA1等位基因频率,分析HLA—DQA1基因多态性,并将所得结果与国内其他民族的同类资料进行比较。结果：新疆吐鲁番地区维吾尔族健康个体中共检出10个等位基因,以DQA1＊0104（O．3727）、DQA1＊0501（0．2636）、DQA1＊0103（0．1318）的频率较高,DQA1＊0401（0．0045）、DQA1＊0601（0．0091）的频率较低。结果与国内其他民族的同类资料进行比较,等位基因分布频率上有共同点,也有一定的独特性。结论：新疆吐鲁番地区维吾尔族HLA—DQA1基因,与国内其他民族群体的资料比较,总体检验有显著差异（p〈0．01）,显示人类的遗传系统既有共性亦有各自的特点,显示华人群体遗传背景的复杂性,结果为人类学研究和HLA—DQA1基因相关的疾病提供了较为重要的信息.     

The serologic screening for celiac disease in the general population (blood donors) and in some high-risk groups of adults (patients with autoimmune diseases,osteoporosis and infertility) in the Czech republic

The prevalence of celiac disease (CD) was determined in healthy blood donors and in high-risk groups of adults (a total of 1835 adults—randomly selected 1312 healthy blood donors, 102 patients with primary osteoporosis, 58 patients with autoimmune diseases and 365 infertile women). It was calculated on the basis of a two-step serologic screening method—in the first step IgA and IgG antigliadin antibodies (AGA) and IgA anti-γ-glutamyltransferase (‘transglutaminase’) antibodies (ATG) were estimated, in the second step sera positive for IgA AGA and/or IgA ATG were examined for antiendomysial IgA (AEA) antibodies. Immunoenzymic assay (ELISA) was used for determining of AGA and ATG antibodies; immunoflurescence method, performed on human umbilical cord tissue, was used for assaying of AEA antibodies. Total serum IgA level in only IgG AGA positive subjects was measured by routine turbidimetric method. 0.45% of healthy blood donors, 0.98% of osteoporotic patients, 2.7% of patients suffering from autoimmune disease and 1.13% of women with infertility considered as immunologically mediated were found to be positive in both steps of serologic screening (AGA and/or ATG and antiendomysium positive). The presumed high prevalence of seropositivity for CD in apparently healthy Czech adult population was confirmed. In the high-risk groups, the prevalence of seropositivity for CD was approximately 2–4 times higher than in healthy blood donors. The real prevalence of CD in the tested groups, however, can be estimated after performing small intestinal biopsy in the seropositive patients.     

药用资源植物雪莲化学成分及药理作用

雪莲主要分布于我国的四川、云南、新疆、青藏高原的高寒山区,是重要的药用资源植物.对雪莲的化学成分及其药理作用等方面的研究做了较为系统的综述.     

羌塘、可可西里无人区野牦牛种群数量和分布现状

野牦牛(Bos grunniens)是青藏高原特有的大型有蹄类动物, 主要分布在西藏羌塘, 青海可可西里、三江源, 新疆阿尔金山等地的高海拔生境。我们于2012-2014年在西藏羌塘和青海可可西里对野牦牛进行了较为全面的实地调查, 并且估算西藏羌塘地区野牦牛种群在11,222-21,072头之间, 可可西里野牦牛种群数量在659-1,793头之间。据本次野外调查和历史文献资料显示, 自20世纪90年代起, 中国野牦牛种群数量逐年增长, 但是其分布区面积却逐步缩减, 目前仅分布在几个相对孤立且远离人类居住地的高寒区域。随着全球气候变化与青藏高原人类活动的加强,野牦牛的生存现状依然严峻, 我们仍需加强对青藏高原特有物种的保护。     

新疆乌苏市育龄妇女生殖健康现况调查研究

目的:了解新疆乌苏市育龄妇女生殖健康现状,生殖保健知识水平和生殖保健意识,为提高育龄妇女的生殖健康水平提供理论依据。方法:采用单纯随机抽样的方法,选择乌苏市育龄妇女1000名,应用自填问卷并结合妇科各项相应检查进行调查分析。结果:(1)妇科健康情况:52.6%被调查者认为自身目前妇科健康状况一般;仅有14.0%的被调查者没有出现过白带异常、下身瘙痒等症状;而平时对生殖道进行日常护理的人仅占57.4%。(2)妇科常见病患病情况:妇科常见疾病按患病率高低排列分别为阴道炎(70.2%)、痛经(25.5%)、宫颈糜烂/乳腺增生(19.2%、19.1%)、子宫肌瘤(11.9%),各因素对痛经的影响均无统计学意义(P>0.05);各因素对阴道炎的影响均无统计学意义(P>0.05);但不同年龄段有宫颈疾病的患病情况差别有统计学意义(P<0.01),其中40～50岁年龄组患病率最大(65.3%),30岁以下年龄组患病率最低(37.6%);城市患病率(57.7%)高于农村(45.6%),差异有统计学意义(P<0.05);小学文化程度患病率(69.0%)高于其他各组差异有统计学意义(P<0.05)。(3)求医行为:37.5%的人选择去药店买药,41.5%的人选择就医;对就医单位的选择中,75.3%的人采取就近原则选择医疗单位,9.1%的人则是通过报纸媒体广告选择相关医疗单位;选择就医单位影响因素中42.3%的人认为专家资质较重要,26.3%的人则认为有先进设备较重要。结论:乌苏市育龄妇女生殖健康水平一般,妇女患常见妇科病比率较大的为阴道炎及痛经,其次为宫颈糜烂/乳腺增生,子宫肌瘤,40～50岁、文化程度较低妇女对宫颈其他疾病的患病情况影响较大,妇女生殖保健知识较全面、自我护理较好的妇女患病率较低。乌苏市育龄妇女需要加强生殖健康宣传教育,提高自我保健意识,掌握基本的生殖保健常识,对40～50岁围绝经期妇女要加强体检力度,以降低妇女病发病率,提高妇女健康水平,改善乌苏市各年龄段的妇女生活质量为关键。     

National,Regional, and Global Trends in Infertility Prevalence Since 1990: A Systematic Analysis of 277 Health Surveys

Background

Global, regional, and national estimates of prevalence of and tends in infertility are needed to target prevention and treatment efforts. By applying a consistent algorithm to demographic and reproductive surveys available from developed and developing countries, we estimate infertility prevalence and trends, 1990 to 2010, by country and region.

Methods and Findings

We accessed and analyzed household survey data from 277 demographic and reproductive health surveys using a consistent algorithm to calculate infertility. We used a demographic infertility measure with live birth as the outcome and a 5-y exposure period based on union status, contraceptive use, and desire for a child. We corrected for biases arising from the use of incomplete information on past union status and contraceptive use. We used a Bayesian hierarchical model to estimate prevalence of and trends in infertility in 190 countries and territories. In 2010, among women 20–44 y of age who were exposed to the risk of pregnancy, 1.9% (95% uncertainty interval 1.7%, 2.2%) were unable to attain a live birth (primary infertility). Out of women who had had at least one live birth and were exposed to the risk of pregnancy, 10.5% (9.5%, 11.7%) were unable to have another child (secondary infertility). Infertility prevalence was highest in South Asia, Sub-Saharan Africa, North Africa/Middle East, and Central/Eastern Europe and Central Asia. Levels of infertility in 2010 were similar to those in 1990 in most world regions, apart from declines in primary and secondary infertility in Sub-Saharan Africa and primary infertility in South Asia (posterior probability [pp] ≥0.99). Although there were no statistically significant changes in the prevalence of infertility in most regions amongst women who were exposed to the risk of pregnancy, reduced child-seeking behavior resulted in a reduction of primary infertility among all women from 1.6% to 1.5% (pp = 0.90) and a reduction of secondary infertility among all women from 3.9% to 3.0% (pp>0.99) from 1990 to 2010. Due to population growth, however, the absolute number of couples affected by infertility increased from 42.0 million (39.6 million, 44.8 million) in 1990 to 48.5 million (45.0 million, 52.6 million) in 2010. Limitations of the study include gaps in survey data for some countries and the use of proxies to determine exposure to pregnancy.

Conclusions

We analyzed demographic and reproductive household survey data to reveal global patterns and trends in infertility. Independent from population growth and worldwide declines in the preferred number of children, we found little evidence of changes in infertility over two decades, apart from in the regions of Sub-Saharan Africa and South Asia. Further research is needed to identify the etiological causes of these patterns and trends. Please see later in the article for the Editors'' Summary     

中国西部电网电击猛禽致死事故调查

2004～2008年调查了西部电网电击猛禽情况.调查区域包括新疆、青海、四川、甘肃、西藏等省区.共统计10 kV和35 kV输电线路长度178 km、杆塔数1 800余根;收集线路附近鸟的尸体、羽毛、残骸等110件,用于鉴定鸟种.调查结果,被电死猛禽计79只(10 kv),平均每千米输电线路1.36只,11.31%的杆塔对鸟类构成威胁;35 kV输电线路上鸟巢数44个,平均每千米输电线路O.37个,至少6.06%杆塔被猛禽利用.已知24%～40%的跳闸停电事故是由于鸟类引发的.症结分析,西部电网结构设计不合理.线路裸露,缺乏防鸟措施.在西部约20%左右的猛禽(11种)受到电击的威胁,同时严重影响着输电线路安全运行.本文提出了合理化建议.