Women infected with parasite Toxoplasma have more sons

The boy-to-girl ratio at birth (secondary sex ratio) is around 0.51 in most populations. The sex ratio varies between societies and may be influenced by many factors, such as stress and immunosuppression, age, primiparity, the sex of the preceding siblings and the socioeconomic status of the parents. As parasite infection affects many immunological and physiological parameters of the host, we analyzed the effect of latent toxoplasmosis on sex ratios in humans. Clinical records of 1,803 infants born from 1996 to 2004 contained information regarding the mother’s age, concentration of anti-Toxoplasma antibodies, previous deliveries and abortions and the sex of the newborn. The results of our retrospective cohort study suggest that the presence of one of the most common parasites (with a worldwide prevalence from 20 to 80%), Toxoplasma gondii, can influence the secondary sex ratio in humans. Depending on the antibody concentration, the probability of the birth of a boy can increase up to a value of 0.72, C.I.₉₅ = (0.636, 0.805), which means that for every 260 boys born, 100 girls are born to women with the highest concentration of anti-Toxoplasma antibodies. The toxoplasmosis associated with immunosuppression or immunomodulation might be responsible for the enhanced survival of male embryos. In light of the high prevalence of latent toxoplasmosis in most countries, the impact of toxoplasmosis on the human population might be considerable.     

海洋生物污染对人群健康的影响及对策

海洋生物为人类提供了丰富的食品、药物资源。然而,海洋环境污染却使得海洋生物受到重金属、难降解有机物、微生物等污染,使得原本优质的海洋食品对食用人群产生危害。研究分析表明．海洋污染物质的主要来源是陆地污染物通过地表径流携带入海。安全的食品离不开安全的水灞、土壤、空气等产地环境,海洋食品亦是如此。应严格按照相关标准向海洋排放陆源污染物,应对入海河流及沿岸排污口实施环境监控和综合治理,从国家政策、公众教育、国际合作等层面加强行动,防范海洋食品安全事故的发生。     

基于遥感影像的2019-2020年盐城市生态保护红线区人类活动动态分析

以盐城市生态保护红线区为研究对象,选用哨兵-2号卫星遥感影像进行目视解译及变化斑块提取,分析其区域内2019-2020年人类活动的变化趋势.结果显示,动态变化情况分为正变化和逆变化,其中逆变化占变化总面积的绝大部分,主要呈现为水田的减少;正变化主要呈现为农村居民点的拆除.总体来说,人类活动变化面积非常少,无工业用地的增...