Differences in sensitivity to the fungal pathogen Batrachochytrium dendrobatidis among amphibian populations

Contributing to the worldwide biodiversity crisis are emerging infectious diseases, which can lead to extirpations and extinctions of hosts. For example, the infectious fungal pathogen Batrachochytrium dendrobatidis (Bd) is associated with worldwide amphibian population declines and extinctions. Sensitivity to Bd varies with species, season, and life stage. However, there is little information on whether sensitivity to Bd differs among populations, which is essential for understanding Bd‐infection dynamics and for formulating conservation strategies. We experimentally investigated intraspecific differences in host sensitivity to Bd across 10 populations of wood frogs (Lithobates sylvaticus) raised from eggs to metamorphosis. We exposed the post‐metamorphic wood frogs to Bd and monitored survival for 30 days under controlled laboratory conditions. Populations differed in overall survival and mortality rate. Infection load also differed among populations but was not correlated with population differences in risk of mortality. Such population‐level variation in sensitivity to Bd may result in reservoir populations that may be a source for the transmission of Bd to other sensitive populations or species. Alternatively, remnant populations that are less sensitive to Bd could serve as sources for recolonization after epidemic events.     

Cleaning carcinogenic nitrosamines with zeolites

N-nitrosamines are characterized with an N-nitroso group N–NO. N-nitrosamines are strong carcinogens or potent carcinogens. Nitrosamines occur widely in the environment, e.g., as tobacco smoke that causes cancers of lungs, larynx, oral cavity and pharynx, pancreas, kidney and bladder. It is difficult to capture selectively N-nitrosamines in the environment. Therefore, zeolite, which is a molecular sieve, may help to sequester N-nitrosamines. Zeolites are a class of aluminosilicates, characterized by ordered microporous structures with acidic–basic sites on the surface and energetic field inside the pores. They have been widely applied in industry as adsorbents and catalysts because of their unique shape selectivity. Here, we review the latest research on adsorption and catalytic degradation of N-nitrosamines by zeolite materials. The efficiency of zeolite is increased using metal oxides. Removal of N-nitrosamines in smoke is discussed.     

Geographical Agglomeration of Chinese Manufacturing Industries

Based on the plant level data from the First National Census of Basic Units, the Second National Census of Basic Units, and the First National Economic Census of China, this paper ex- amines the geographical agglomeration of Chinese manufacturing industries at a more disaggregated level both by industrial classi-fication and spatial unit analysis. Applying the agglomeration index proposed by Maurel and Sedillot, studies show that the most agglomerated industries are resource-intensive, and capital and technology intensive while industries demanding localized inputs or serving localized markets or favored by local governments are fairly dispersed. The more disaggregated industries are more spa- tially agglomerated. At the finer spatial scale, industries are more dispersed. Results indicate that within-county spillovers are stronger than nearby-county spillovers, and within-prefecture spillovers are stronger than nearby prefecture spillovers. Local- ized spillovers are still quite substantial at a range beyond that of counties. Comparing the agglomeration index of Chinese manu- facturing industries in 1996, 2001 and 2004, agglomeration seems to be a general tendency. Results also indicate that some industries have experienced remarkable changes in their levels of agglom- eration in the period 1996–2004.     

农林复合生态系统氮素平衡及其评价

农业生态系统中养分的平衡状况及其合理性评价，是探讨农业生产和环境变化的前提和基础。选择三峡库区上游川中丘陵区一典型农林复合生态系统，依据系统养分循环概念模型，进行了农田和林地定位监测、耕地和盆钵模拟试验以及参与式农户调查等，研究系统的氮素各收入支出参数，计算系统的氮素平衡并对平衡合理性进行评价。结果表明，本复合生态系统旱地和整个农田子系统氮素略有盈余，盈亏量分别为56.1 kg/hm2·a和42 kg/hm\2·a，实际盈亏率为10.4%和8.2%；而水稻田和复合系统有少量亏缺，盈亏量分别为-13.21 kg/hm2·a和-37.5 kg/hm2·a，实际盈亏率分别为为-3.2%和-7.8%；林地亏缺较大，盈亏量为-165.9 kg/hm2·a，实际盈亏率为-39.2%。模型计算的允许盈亏率（旱地23.4%，水稻田-37.2%）评价表明，旱地和水稻田目前的氮素平衡基本上是合理的。与1960s系统氮平衡比较，可以看到林地在减少水土流失、促进养分的合理循环方面发挥了重要作用，应受到充分的重视。     

原子吸收光谱仪的背景校正

介绍了原子吸收光谱仪的５种主要的背景校正技术（邻近谱线技术，连续光源法，塞曼法，自吸法及连续光源单色器波长调节法ＣＥＷＭ）及其主要产品，分析评述了各种校正技术的原理，特点及其应用状况。     

生态哲学维度:人口生态生产与可持续发展

适度人口理论为可持续发展战略的实现提供了良好条件。如果进一步考察可持续发展概念的内涵，不难发现人口特质在可持续发展中居于核心地位，特别是其空间分布特征更具有现实意义。认定全方位适度人口的目标追求是人类社会可持续发展的一条基本实现途径。而全方位适度人口目标的实现则依赖于人口的合理生产，如何做到合理生产我们给出生态哲学维度，提出人口生态生产，即人口在生产与再生产过程中在生物学与社会学层面上始终贯彻人口数量、人口质量、人口结构、人口分布生态化的原则。     

湘中涟源煤盆地煤层气形成气藏的条件及其资源预测

湘中涟源煤盆地早石炭世测水组、晚二叠世龙潭组煤系是中国东南诸省境内最重要的煤系，具有较大的生气、储气能力。本文从煤系的构造热滨化、构造、沉积及煤层理深等方面论述了研究区测水组、龙潭组煤系中煤层气形成气藏的条件，并指出煤层气的开发远景区应该在煤盆地近南缘的诸含煤向斜南西扬起端，其中各主要区域性断裂交汇而成的断块是最重要的靶区。     

化学物质结构信息系统的建立及图形输出子系统

本文介绍化合物毒性数据库的结构子库和图形输出子系统。数据库是以美国EPA结构信息源(SANSS)并自编软件系统而建成。该系统存有23万种化合物的结构信息,可用CAS登记号,分子式及其别名和基本名对结构库进行检索,并配有包括六元环和六元环以下的结构图形输出。建库与检索软件用COBOL语言实现,图形输出软件用PASCAL语言实现。通过计算最小环的方法,以环为核心逐步生成图形。     

啤酒废酵母的综合利用

啤酒废酵母含有丰富的营养物质，许多啤酒厂并没有充分利用，而是作为废弃物排入啤酒废水，增加了啤酒废水的处理负荷和难度。针对这种情况，我们利用本厂啤酒废酵母进行了生产酵母抽提物及营养酱油的研究，取得了满意的效果。不仅获得了优质产品，而且大大降低了啤酒酵母的污染负荷。     

用疣荔枝螺性畸变监测海洋有机锡污染的方法初探

选取我国沿海广泛分布的疣荔枝螺为海洋有机锡污染的指示种 ,对疣荔枝螺性畸变的调查方法、分析方法和性畸变程度评价指标等作了初步探讨 ,并以厦门港疣荔枝螺性畸变的调查结果为例讨论了疣荔枝螺性畸变在海洋有机锡污染生物监测中的具体应用 ,以期建立我国海洋有机锡污染的生物监测体系。