抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(12)61766-8.pdf

A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010

Identifying and quantifying planetary boundaries that must not be transgressed could help prevent human activities from causing unacceptable environmental change, argue Johan Rockstrom and colleagues.

/pdf/a-safe-operating-space-for-humanity-tynyc6i2kf.pdf

A safe operating space for humanity

Human alteration of Earth is substantial and growing. Between one-third and one-half of the land surface has been transformed by human action; the carbon dioxide concentration in the atmosphere has increased by nearly 30 percent since the beginning of the Industrial Revolution; more atmospheric nitrogen is fixed by humanity than by all natural terrestrial sources combined; more than half of all accessible surface fresh water is put to use by humanity; and about one-quarter of the bird species on Earth have been driven to extinction. By these and other standards, it is clear that we live on a human-dominated planet.

/pdf/human-domination-of-earth-s-ecosystems-5eevmqq987.pdf

Human Domination of Earth's Ecosystems

This paper describes the contents of the 2016 edition of the HITRAN molecular spectroscopic compilation. The new edition replaces the previous HITRAN edition of 2012 and its updates during the intervening years. The HITRAN molecular absorption compilation is composed of five major components: the traditional line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, infrared absorption cross-sections for molecules not yet amenable to representation in a line-by-line form, collision-induced absorption data, aerosol indices of refraction, and general tables such as partition sums that apply globally to the data. The new HITRAN is greatly extended in terms of accuracy, spectral coverage, additional absorption phenomena, added line-shape formalisms, and validity. Moreover, molecules, isotopologues, and perturbing gases have been added that address the issues of atmospheres beyond the Earth. Of considerable note, experimental IR cross-sections for almost 300 additional molecules important in different areas of atmospheric science have been added to the database. The compilation can be accessed through www.hitran.org. Most of the HITRAN data have now been cast into an underlying relational database structure that offers many advantages over the long-standing sequential text-based structure. The new structure empowers the user in many ways. It enables the incorporation of an extended set of fundamental parameters per transition, sophisticated line-shape formalisms, easy user-defined output formats, and very convenient searching, filtering, and plotting of data. A powerful application programming interface making use of structured query language (SQL) features for higher-level applications of HITRAN is also provided.

/pdf/the-hitran-2008-molecular-spectroscopic-database-1ud8clpej3.pdf

The HITRAN 2008 molecular spectroscopic database

Etude de dispersion et du devenir des derives du soufre et de l'azote, de metaux lourds et composes organiques par le programme WATOX. Utilisation de diverses methodes d'echantillonnage, de tracage par aerosols et de precipitation pour determiner les cycles atmospheriques chimiques de l'Ouest de l'Ocean Atlantique

The Western Atlantic Ocean Experiment

With the increasing industrialization and population of the world, the impact of anthropogenic activities on the atmosphere is evident on several spatial scales. Population centers in developed and developing countries are being affected locally (e.g., visibility reduction) and regionally (e.g., acid deposition) by the release of combustion products into the atmosphere. Through studying these local and regional effects, it is now realized that the contributing materials are not entirely deposited in the region in which they are emitted. The materials can be transported over thousands of kilometers (e.g., Levy and Moxim 1987, Whelpdale et al. 1984). Thus, hemispheric and global scales of atmospheric contamination are now realities.

The Intercontinental Transport of Sulfur and Nitrogen

Nitrogen balance sheets are useful tools for studying the quantitative aspects of nutrients. Nitrogen balance sheets have been prepared for the animal production system, crop production system, and for the agricultural sector as a whole for all 15 member states of the European Union (EU15) and for the Indian subcontinent. The EU15 and India were chosen for this study on nitrogen efficiency using balance sheets because they each occupy roughly 300 million ha of land and use about 65 kg nitrogen fertiliser per hectare of agricultural land. Balance sheets were constructed for three systems: animal production, crop production, and the agricultural sector as a whole. In addition to detailed descriptions of the nitrogen balance sheets, brief recommendations for reducing nitrogen surpluses are also given. Surprisingly, the balance sheets for crop production and the agricultural sector as a whole showed a surplus of about 60 kg of nitrogen per hectare of agricultural land.

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Nitrogen efficiency in agriculture in Europe and India.

The article reviews effects of nitrogen (N) deposition on beech forest ecosystems in Europe. On the basis of beech plots of the Pan-European Monitoring Programme of ICP Forests and the EU, the deposition of N compounds as well as input-output budgets are listed and compared with studies in North America. The authors also discuss the critical threshold for N leaching. At present, N is leached in 10% of the plots evaluated. An in-depth evaluation of a beech plot in central Germany is presented. The high N leaching results in a considerable increase (four times higher N content in 2000 compared to 1965) in the export of nitrate from the beech forests from a nearby source. Finally, ecophysiological indicators (N content in beech leaves, fine root system, N content, root/shoot ratios) are discussed as a result of high N input.

Assessments of impacts of nitrogen deposition on beech forests: results from the Pan-European Intensive Monitoring Programme.

Materials present in the atmosphere can be deposited by a wide range of mechanisms. Historically, these deposition mechanisms have been divided into two categories: vet processes and dry processes. The vet process most commonly studied is that involving precipitation as rain, snow, or ice. Dry deposition to the earth’s surface takes place through a wide range of physical mechanisms including the sedimentation, impaction, interception, and diffusion of particles and the diffusion of gases. Another important type of deposition involves cloud and fog droplets.

James N. Galloway

Papers

The Western Atlantic Ocean Experiment

The Intercontinental Transport of Sulfur and Nitrogen

Nitrogen efficiency in agriculture in Europe and India.

Assessments of impacts of nitrogen deposition on beech forests: results from the Pan-European Intensive Monitoring Programme.

The Deposition of Sulfur and Nitrogen from the Remote Atmosphere Working-Group Report