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

Background Global and regional projections of mortality and burden of disease by cause for the years 2000, 2010, and 2030 were published by Murray and Lopez in 1996 as part of the Global Burden of Disease project. These projections, which are based on 1990 data, continue to be widely quoted, although they are substantially outdated; in particular, they substantially underestimated the spread of HIV/AIDS. To address the widespread demand for information on likely future trends in global health, and thereby to support international health policy and priority setting, we have prepared new projections of mortality and burden of disease to 2030 starting from World Health Organization estimates of mortality and burden of disease for 2002. This paper describes the methods, assumptions, input data, and results. Methods and Findings Relatively simple models were used to project future health trends under three scenarios—baseline, optimistic, and pessimistic—based largely on projections of economic and social development, and using the historically observed relationships of these with cause-specific mortality rates. Data inputs have been updated to take account of the greater availability of death registration data and the latest available projections for HIV/AIDS, income, human capital, tobacco smoking, body mass index, and other inputs. In all three scenarios there is a dramatic shift in the distribution of deaths from younger to older ages and from communicable, maternal, perinatal, and nutritional causes to noncommunicable disease causes. The risk of death for children younger than 5 y is projected to fall by nearly 50% in the baseline scenario between 2002 and 2030. The proportion of deaths due to noncommunicable disease is projected to rise from 59% in 2002 to 69% in 2030. Global HIV/AIDS deaths are projected to rise from 2.8 million in 2002 to 6.5 million in 2030 under the baseline scenario, which assumes coverage with antiretroviral drugs reaches 80% by 2012. Under the optimistic scenario, which also assumes increased prevention activity, HIV/AIDS deaths are projected to drop to 3.7 million in 2030. Total tobacco-attributable deaths are projected to rise from 5.4 million in 2005 to 6.4 million in 2015 and 8.3 million in 2030 under our baseline scenario. Tobacco is projected to kill 50% more people in 2015 than HIV/AIDS, and to be responsible for 10% of all deaths globally. The three leading causes of burden of disease in 2030 are projected to include HIV/AIDS, unipolar depressive disorders, and ischaemic heart disease in the baseline and pessimistic scenarios. Road traffic accidents are the fourth leading cause in the baseline scenario, and the third leading cause ahead of ischaemic heart disease in the optimistic scenario. Under the baseline scenario, HIV/AIDS becomes the leading cause of burden of disease in middle- and low-income countries by 2015. Conclusions These projections represent a set of three visions of the future for population health, based on certain explicit assumptions. Despite the wide uncertainty ranges around future projections, they enable us to appreciate better the implications for health and health policy of currently observed trends, and the likely impact of fairly certain future trends, such as the ageing of the population, the continued spread of HIV/AIDS in many regions, and the continuation of the epidemiological transition in developing countries. The results depend strongly on the assumption that future mortality trends in poor countries will have a relationship to economic and social development similar to those that have occurred in the higher-income countries.

/pdf/projections-of-global-mortality-and-burden-of-disease-from-16p7emcopm.pdf

Projections of Global Mortality and Burden of Disease from 2002 to 2030

http://diposit.ub.edu/dspace/bitstream/2445/122776/1/gbd2016riskfactorscollaborators2017_3028.pdf

Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks in 188 countries, 1990-2013: A systematic analysis for the Global Burden of Disease Study 2013

Food in the Anthropocene: the EAT–Lancet Commission on healthy diets from sustainable food systems

Estimates and 25-year trends of the global burden of disease attributable to ambient air pollution: an analysis of data from the Global Burden of Diseases Study 2015

In developing and industrial countries alike, there is concern that health and safety policy may respond to irrational fears - to the"disaster of the month"- rather than address more fundamental problems. In the United States, for example, some policymakers say the public worries about trivial risks while ignoring larger ones and that funding priorities reflect this view. Many public health programs with a low cost per life saved are underfunded, for example, while many environmental regulations with a high cost per life saved are issued each year. Does the existing allocation of resources reflect people's preoccupation with the qualitative aspects of risks, to the exclusion of quantitative factors (lives saved)? Or can observed differences in the cost per life saved of environmental and public health programs be explained by the way the two sets of programs are funded? The authors examine the preferences of U.S. citizens for health and safety programs. They confronted a random sample of 1,000 U.S. adults with choices between environmental health and public health programs, to see which they would choose. The authors then examined what factors (qualitative and quantitative) seem to influence these choices. Respondents were asked about pairs of programs, among them: smoking education or industrial pollution control programs, industrial pollution control or pneumonia vaccine programs, radon eradication or a program to ban smoking in the workplace, and radon eradication or programs to ban pesticides. The survey results, they feel, have implications beyond the United States. They find that, while qualitative aspects of the life-saving programs are statistically significant in explaining people's choices among them, lives saved matter, too. Indeed, for the median respondent in the survey, the rate of substitution between most qualitative risk characteristics and lives saved is inelastic. But for a sizable minority of respondents, choice among programs appears to be insensitive to lives saved. The interesting question for public policy is what role the latter group plays in the regulatory process.

Public choices between lifesaving programs: how important are lives saved?

This paper describes the role of public transport and the nature and incidence of transport subsidies in Mumbai, India. Mumbai has an extensive rail and bus network, and public transport is used for over 75 percent of all motorized trips in Greater Mumbai. Both rail and bus fares in Mumbai are subsidized: BEST, which operates public buses in Mumbai, is also an electric utility, and subsidizes bus fares from electricity revenues. We analyze the incidence of these subsidies, and their effect on mode choice, using data from a survey of households in Greater Mumbai. In Mumbai, as in many cities, the middle class is more likely to use public transport for travel than the poor. The poor, however, also use public transit, and their expenditure on public transit constitutes, on average, a larger share of their income than it does for the middle class. It is, therefore, the case that the poor benefit from transit subsidies in Mumbai, as well as the middle and upper-middle classes; however, the poorest 27 percent of the population receives only 19 percent of bus subsidies and 15.5 percent of rail subsidies. Indeed, 26 percent of the lowest income households surveyed do not use rail, while 10 percent do not use bus, implying that they receive no transit subsidies. Expenditure on transport accounts for 16 percent of income in the lowest income category (<5000 Rs./month), with 10 percent of income, on average, spent on bus and rail fares. This percentage, however, is not evenly distributed: it is much higher than 10 percent for households in which workers take the bus or train to work, and lower for households in which the main earner walks to work. Even in these households, however, 12.5 percent of income is spent on transportation. Expenditure on public transport would be even higher if bus fares in Mumbai were not subsidized. In 2005-2006, transport revenues of BEST fell below total costs by 30 percent and below operating costs by 20 percent. Rail fares, which are much lower than bus fares per km traveled, officially covered operating costs and almost covered depreciation expenses.

/pdf/public-transport-subsidies-and-affordability-in-mumbai-india-1n34d8lwfr.pdf

Public Transport Subsidies and Affordability in Mumbai, India

Establishing protected areas (national parks together with wildlife sanctuaries) in North Thailand did not reduce the likelihood of forest clearing, but wildlife sanctuaries may have reduced the probability of deforestation. Where new roads are located affects how much of a threat they are to protected areas. Using plot-level data, Cropper, Puri, and Griffiths estimate a bivariate probit model to explain land clearing and the siting of protected areas in North Thailand in 1986. Their model suggests that protected areas (national parks together with wildlife sanctuaries) did not reduce the likelihood of forest clearing, but wildlife sanctuaries may have reduced the probability of deforestation. Road building, by reducing the impedance-weighted distance to market, has promoted clearing, especially near the forest fringe. The authors simulate the impact of further road building to show where road building is likely to have the greatest impact on forest clearing and where it is likely to threaten protected areas. This paper - a product of Infrastructure and Environment, Development Research Group - is part of a larger effort in the group to examine factors affecting deforestation in developing countries. The study was funded by the Bank's Research Support Budget under the research project "Spatial Models of Environmental Processes: A Study of Deforestation in Thailand" (RPO 683-17). The authors may be contacted at mcropper@worldbank.org, jpuri@worldbank.org, or griffiths.charles@epa.gov.

https://papers.ssrn.com/sol3/Delivery.cfm/1692.pdf?abstractid=632652&mirid=1

How the Location of Roads and Protected Areas Affects Deforestation in North Thailand

Title IV of the 1990 Clean Air Act Amendments (CAAA) established a market for transferable sulfur dioxide (SO2) emission allowances among electric utilities. This market offers firms facing high marginal abatement costs the opportunity to purchase the right to emit SO2 from firms with lower costs, and is expected to yield cost savings compared to a command and control approach to environmental regulation. This paper uses econometrically estimated marginal abatement cost functions for power plants affected by Title IV of the CAAA to evaluate the performance of the SO2 allowance market. Specifically, we investigate whether the much-heralded fall in the cost of abating SO2, compared to original estimates, can be attributed to allowance trading. We demonstrate that, for plants using low-sulfur coal to reduce SO2 emissions, technical changes and the fall in low-sulfur coal prices have lowered marginal abatement cost curves by over 50% since 1985. The flexibility to take advantage of these changes is the main source of cost reductions, rather than trading per se. In the long run, allowance trading may achieve cost savings of $700-$800 million per year compared to an "enlightened" command and control program characterized by a uniform emission rate standard. The cost savings would be twice as great if the alternative to trading were forced scrubbing. However, a comparison of potential cost savings in 1995 and 1996 with actual emissions costs suggests that most trading gains were unrealized in the first two years of the program.

Sulfur-Dioxide Control By Electric Utilities: What Are the Gains from Trade?

Concerns about nutrient pollution in the Chesapeake Bay have led to the establishment of pollution limits — total maximum daily loads (TMDLs) — which, by 2025, are expected to reduce nitrogen loadings to the Bay by 25 percent and phosphorous loadings by 24 percent from current levels. This paper outlines how the benefits associated with achieving the Chesapeake Bay TMDLs could be measured and monetized. We summarize studies that measure the benefits of improved water quality in the Bay and evaluate whether these studies could be used to value the water quality benefits associated with the TMDLs. In cases where studies conducted in the Bay watershed either do not exist or are out of date, we discuss whether results from studies conducted elsewhere could be transferred to the Chesapeake Bay. We also discuss original studies that would be useful to conduct in the future.

https://papers.ssrn.com/sol3/Delivery.cfm?abstractid=1978471

Maureen L. Cropper

Papers

Public choices between lifesaving programs: how important are lives saved?

Public Transport Subsidies and Affordability in Mumbai, India

How the Location of Roads and Protected Areas Affects Deforestation in North Thailand

Sulfur-Dioxide Control By Electric Utilities: What Are the Gains from Trade?

The Benefits of Achieving the Chesapeake Bay TMDLs (Total Maximum Daily Loads): A Scoping Study