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

Summary for policymakers Technical summary 1. The climate system - an overview 2. Observed climate variability and change 3. The carbon cycle and atmospheric CO2 4. Atmospheric chemistry and greenhouse gases 5. Aerosols, their direct and indirect effects 6. Radiative forcing of climate change 7. Physical climate processes and feedbacks 8. Model evaluation 9. Projections of future climate change 10. Regional climate simulation - evaluation and projections 11. Changes in sea level 12. Detection of climate change and attribution of causes 13. Climate scenario development 14. Advancing our understanding Glossary Index Appendix.

Climate change 2001: the scientific basis

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.

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A safe operating space for humanity

Drafting Authors: Neil Adger, Pramod Aggarwal, Shardul Agrawala, Joseph Alcamo, Abdelkader Allali, Oleg Anisimov, Nigel Arnell, Michel Boko, Osvaldo Canziani, Timothy Carter, Gino Casassa, Ulisses Confalonieri, Rex Victor Cruz, Edmundo de Alba Alcaraz, William Easterling, Christopher Field, Andreas Fischlin, Blair Fitzharris, Carlos Gay García, Clair Hanson, Hideo Harasawa, Kevin Hennessy, Saleemul Huq, Roger Jones, Lucka Kajfež Bogataj, David Karoly, Richard Klein, Zbigniew Kundzewicz, Murari Lal, Rodel Lasco, Geoff Love, Xianfu Lu, Graciela Magrín, Luis José Mata, Roger McLean, Bettina Menne, Guy Midgley, Nobuo Mimura, Monirul Qader Mirza, José Moreno, Linda Mortsch, Isabelle Niang-Diop, Robert Nicholls, Béla Nováky, Leonard Nurse, Anthony Nyong, Michael Oppenheimer, Jean Palutikof, Martin Parry, Anand Patwardhan, Patricia Romero Lankao, Cynthia Rosenzweig, Stephen Schneider, Serguei Semenov, Joel Smith, John Stone, Jean-Pascal van Ypersele, David Vaughan, Coleen Vogel, Thomas Wilbanks, Poh Poh Wong, Shaohong Wu, Gary Yohe

Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change

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.

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The HITRAN 2008 molecular spectroscopic database

By backscattering solar radiation, aerosol particles and clouds exert a cooling (parasol) effect on climate, dampening Earth's warming by the greenhouse gases (GHG) (T. L. Anderson et al. , “Climate forcing by aerosols—a hazy picture,” Perspectives, 16 May, p. [1103][1]) ([1][2]). Based

The parasol effect on climate.

During the Indian Ocean Experiment (INDOEX) in February-March 1999 the impact of continental outflow to the Indian Ocean was analyzed. On board the R/V Ronald Brown altogether 93 air samples were taken for analysis of nonmethane hydrocarbons (NMHC), methane (CH 4 ), carbon dioxide (CO 2 ), carbon monoxide (CO), and the 14 C/ 12 C and 18 O/ 16 O isotope ratios of CO. Five types of air masses differing in origin, degree of pollution, and chemical age were identified based on back trajectory analyses and the trace gas data, supported by continuous CO and ozone (O 3 ) observations from other investigators. The Indian Ocean was found to be frequently affected by nearby emissions from the Indian subcontinent and Indochina, but the strongest pollution event (characterized inter alia by high mixing ratios of medium- and long-lived NMHC) was due to long-range advection from the extratropical northern hemisphere. Carbon monoxide 14 showing a distinct meridional profile unequivocally confirms this remote impact. The ratio acetylene/CO was found to be often inadequate as a measure for atmospheric processing, the integrated influence of OH chemistry and mixing. Our data suggest that the influence from fresh continental pollution was less pronounced along the INDOEX R/V Ronald Brown cruise compared to observations made during other tropical campaigns, such as the Pacific Exploratory Mission-West B in the Pacific Ocean.

Air mass classification during the INDOEX R/V Ronald Brown cruise using measurements of nonmethane hydrocarbons, CH4, CO2, CO, 14CO, and δ18O(CO) : Indian Ocean Experiment (INDOEX)

SciENTIFIC AssESSMENT OF OzoNE DEPLETION: 1998

Stratospheric temperatures at high latitudes in the 10- to 30-mbar layer are found to have been approximately in phase with the solar cycle during the period 1951–1970. These findings suggest an influence by galactic or solar cosmic rays. To study the possible effect of solar proton events on stratospheric temperatures, we have chosen to investigate one of the largest known solar proton events, that of August 1972. It is expected that after this event, significant changes in the temperature and ozone distributions should have taken place at high latitudes. This is tentatively confirmed by experimental data from the Canadian stations. It is tentatively proposed that variations in stratospheric temperatures and ozone concentrations at high latitudes over the solar cycle may be caused by similar variations in the production rates of nitric oxide by galactic or solar cosmic rays or a combination of both.

Stratospheric thickness variations over the northern hemisphere and their possible relation to solar activity

Humans seem to have doubled the global rate of terrestrial nitrogen fixation. Globally 50–70% (85 Tg, 1 Tg=1012 g) of the nitrogen supplied in fertilizer (80 Tg N/a) and leguminous crops (40–80 Tg N/a) are used to feed cattle. The aim of the present study was to derive some estimates of global N2O production from animal manure. As the parameter giving the most stable numerical basis for regional and global extrapolation we adopted the molar emission ratios of N2O to NH3. These ratios were measured in cattle, pig and chicken housings with different manure handling systems, in dung-heaps and in liquid manure storage tanks. Individual molar emission ratios from outside manure piles varied over two orders of magnitude, strongly dependent on the treatment of the manure. A median emission ratio of 1.6×10-2 (n=65) was obtained in cow-sheds with slatted floors and liquid manure stored underneath and a median ratio of 24×10-2 (n=31) was measured in a beef cattle housing with a solid manure handling system.

Paul J. Crutzen

Papers

The parasol effect on climate.

Air mass classification during the INDOEX R/V Ronald Brown cruise using measurements of nonmethane hydrocarbons, CH4, CO2, CO, 14CO, and δ18O(CO) : Indian Ocean Experiment (INDOEX)

SciENTIFIC AssESSMENT OF OzoNE DEPLETION: 1998

Stratospheric thickness variations over the northern hemisphere and their possible relation to solar activity

Estimates of global N2O emissions from cattle, pig and chicken manure, including a discussion of CH4 emissions