G20峰会期间杭州市大气区域输送特征研究

利用拉格朗日扩散模型评估G20峰会期间杭州市大气区域输送特征,结果表明,G20峰会开幕期间杭州市的气团来源由西南内陆转为杭州湾和东海地区,且传输速度较快,空气污染得到显著清除。保障期间污染情形下,苏北、安徽、江西等地的气团输送更强,浙北和苏南地区输送减弱。在管控情形下,浙北的PM_2.5一次排放潜在贡献降低了15%,减排管控措施有效降低了周边地区一次排放对杭州市的空气污染输送。1981—2016年G20峰会历史同期,浙江省对杭州市的气团贡献年际变化幅度为26%~85%,平均贡献为63%。     

Toward an integrative molecular approach to wildlife disease

Pathogens pose serious threats to human health, agricultural investment, and biodiversity conservation through the emergence of zoonoses, spillover to domestic livestock, and epizootic outbreaks. As such, wildlife managers are often tasked with mitigating the negative effects of disease. Yet, parasites form a major component of biodiversity that often persist. This is due to logistical challenges of implementing management strategies and to insufficient understanding of host–parasite dynamics. We advocate for an inclusive understanding of molecular diversity in driving parasite infection and variable host disease states in wildlife systems. More specifically, we examine the roles of genetic, epigenetic, and commensal microbial variation in disease pathogenesis. These include mechanisms underlying parasite virulence and host resistance and tolerance, and the development, regulation, and parasite subversion of immune pathways, among other processes. Case studies of devil facial tumor disease in Tasmanian devils (Sarcophilus harrisii) and chytridiomycosis in globally distributed amphibians exemplify the broad range of questions that can be addressed by examining different facets of molecular diversity. For particularly complex systems, integrative molecular analyses present a promising frontier that can provide critical insights necessary to elucidate disease dynamics operating across scales. These insights enable more accurate risk assessment, reconstruction of transmission pathways, discernment of optimal intervention strategies, and development of more effective and ecologically sound treatments that minimize damage to the host population and environment. Such measures are crucial when mitigating threats posed by wildlife disease to humans, domestic animals, and species of conservation concern.     

A role for selective contraception of individuals in conservation

Contraception has an established role in managing overabundant populations and preventing undesirable breeding in zoos. We propose that it can also be used strategically and selectively in conservation to increase the genetic and behavioral quality of the animals. In captive breeding programs, it is becoming increasingly important to maximize the retention of genetic diversity by managing the reproductive contribution of each individual and preventing genetically suboptimal breeding through the use of selective contraception. Reproductive suppression of selected individuals in conservation programs has further benefits of allowing animals to be housed as a group in extensive enclosures without interfering with breeding recommendations, which reduces adaptation to captivity and facilitates the expression of wild behaviors and social structures. Before selective contraception can be incorporated into a breeding program, the most suitable method of fertility control must be selected, and this can be influenced by factors such as species life history, age, ease of treatment, potential for reversibility, and desired management outcome for the individual or population. Contraception should then be implemented in the population following a step‐by‐step process. In this way, it can provide crucial, flexible control over breeding to promote the physical and genetic health and sustainability of a conservation dependent species held in captivity. For Tasmanian devils (Sarcophilus harrisii), black‐flanked rock wallabies (Petrogale lateralis), and burrowing bettongs (Bettongia lesueur), contraception can benefit their conservation by maximizing genetic diversity and behavioral integrity in the captive breeding program, or, in the case of the wallabies and bettongs, by reducing populations to a sustainable size when they become locally overabundant. In these examples, contraceptive duration relative to reproductive life, reversibility, and predictability of the contraceptive agent being used are important to ensure the potential for individuals to reproduce following cessation of contraception, as exemplified by the wallabies when their population crashed and needed females to resume breeding.     

Alcohol-related deaths among young passengers: An analysis of national alcohol-related fatal crashes

Introduction: There is consensus that riding with an impaired driver (RWI) constitutes a major threat to public health. The aim of this study was to characterize the factors contributing to the motor-vehicle deaths of 15–20 year-old (y/o) passengers that RWI with a peer. Method: Secondary analyses of the 2010–2018 Fatality Analysis Reporting System. 5,673 passengers aged 15–20 y/o killed while riding in passenger cars with a driver aged 21 or older, 3,542 of these drivers also aged 15–20 y/o. Analyses were conducted between October 2019 and December 2020. Results: Sixty-three percent of the young passengers were killed while riding with a driver 15–20 y/o. Of these drivers, 26.8% had a blood alcohol concentration (BAC) >0.00 g/dL and 77.1% had a BAC ≥0.08 g/dL. Compared with those occurring during the day on weekdays, fatalities of young passengers who RWI with a peer driver with a BAC ≥ 0.08 g/dL often occurred on weekend nights (OR = 8.2) and weekday nights (OR = 5.2), and when the passenger and driver were both male (OR = 1.8). Race/ethnicity was not a significant contributor to RWI fatalities. Conclusions: Most 15–20 y/o RWI fatalities occurred on weekends, at night, when the driver was a young peer with a high BAC, and the passenger and driver were male. The high prevalence of fatalities in these high-risk situations suggests that young driver-passenger dynamics may contribute to alcohol-related fatalities. Practical Applications: To curb RWI fatalities among underage passengers, countermeasures should focus not only on underage drinking drivers and riders, but also on drinking drivers of all ages. Prevention should increase focus on situations in which both the young passenger and young driver are males.     

Mosaic triple trisomy in amniocytes from a phenotypically and karyotypically normal fetus

We report the detection of a mosaic triple trisomy, 46, XY/49, XY, + 13, +20, +21, in two amniotic fluid specimens obtained from a pregnancy that yielded a normal infant. Traditional cytogenetic methods failed to detect the abnormal cell lineage in fetal blood, foreskin, amnion, umbilical cord, and three different biopsies of the chorion. In addition, fluorescence in situ hybridization study of cells from a buccal smear showed no evidence of cells with three copies of chromosome 20.     

Trisomy 20 mosaicism in amniotic fluid cells

The significance of trisomy 20 mosaicism in cultured amniotic fluid cells is still confusing. We report a case of amniotic cell normal/trisomy 20 mosaicism diagnosed prenatally. The pregnancy was carried to term and a normal baby girl was delivered. The authors consider that in cases of amniotic fluid cell normal/trisomy 20 mosaicism the termination of pregnancy may not be advised, however, the parents should be fully informed.     

Tween 20 and Its Major Free Fatty Acids as Carbon Substrates for the Production of Polyhydroxyalkanoates in Pseudomonas aeruginosa ATCC 27853

The ability of Pseudomonas aeruginosa ATCC 27853 to grow and synthesize polyhydroxyalkanoates (PHAs) using Tween 20 as the sole carbon source was investigated. Tween 20 could support cell growth and PHA production. The polymer produced from Tween 20 was compared with those produced from its major free fatty acids components: lauric (C₁₂), myristic (C₁₄), and palmitic (C₁₆) acids. Gas-chromatographic analysis of methanolyzed samples and ¹³C-Nuclear Magnetic Resonance (NMR) showed that the PHAs obtained are composed of even carbon atoms 3-hydroxyalkanoates ranging from C₆ to C₁₄, with C₈ and C₁₀ as the predominant components. The nature of the carbon sources used had little influence on the composition, but was found to be important in determining the average molecular weight, shorter chain fatty acids yielding higher molecular weight products. Fast Atom Bombardment-Mass Spectrometry (FAB-MS) of partially pyrolyzed samples, coupled to statistical analysis, showed that these PHAs are random copolymers.     

《中国21世纪议程》:迎接挑战的战略抉择与实践探索

制定《中国21世纪议程》是中国发展必然的战略选择,是中国履行环发大会精神的重要举措。近20年来,我国立足基本国情,积极推进《中国21世纪议程》的实施,探索实践中国特色的可持续发展道路,做出了巨大努力,在发展经济、消除贫困、节约资源、保护环境等领域取得了举世瞩目的成就,对全球可持续发展做出了重要贡献。随着世情国情的深刻变化,我国进一步实施可持续发展战略面临着新的挑战,发展中不平衡、不协调、不可持续的问题依然严峻,发展的任务仍然十分艰巨。我们应该坚持以科学发展观为统领,坚定不移地走中国特色的可持续发展之路,充分把握全球绿色技术创新迸发的历史机遇,切实加快经济发展方式的转变;坚持共同但有区别责任的原则和合作共赢的理念,积极参与全球可持续发展治理,促进世界的可持续发展、和谐发展。     

YSZ-W复合涂层的制备及抗烧蚀性能研究

目的 在TC4表面制备均匀致密的YSZ-20％(体积分数)W(ZW2)复合涂层,以提高其抗烧蚀性能,并对其在超音速燃流中的烧蚀响应机制进行初步探究.方法 以8YSZ和W粉为原料,采用喷雾干燥-真空烧结工艺制备喷涂用ZW2复合粉末,利用大气等离子喷涂技术(APS)制备ZW2复合涂层,采用超音速火焰冲刷法(SCF)测试涂层...     

The supply behaviour of state mining enterprises: A case study of the Jordanian phosphate industry

An important feature of export-oriented production in mineral-rich developing countries for almost three decades after 1960 was the growth of state-owned enterprises. For the phosphate industry, this was reflected in the expansion of companies such as Office Cherifienne des Phosphate (OCP) in Morocco and the Jordan Phosphate Mines Company (JPMC). There was a strategic importance of the industry for these nations and the large capital outlays necessary for phosphate and fertilizer production expansion often required considerable government assistance because of the perceived high risks of private investment in the industry.