SciDev.Net

This article describes how a network of sensors, linked by software and the Internet, can provide an automatic satellite-based surveillance system for disasters such as volcanoes, wildfires and flooding.

The system, or 'Sensorweb', uses data from low resolution, high frequency sensors to trigger imagery from high resolution instruments. The low-resolution data is collected regularly (twice a day or more) from instruments such as NASA's Moderate Resolution Imaging Spectroradiometer (MODIS).

Anomalies, such as hotspots in the case of fires and volcanoes or surface water for floods, are automatically detected. The SensorWeb then sends a request to a higher resolution satellite such as Hyperion, which is very sensitive in the infrared spectrum, to request data over the area of interest. These data can then provide disaster managers with early warnings of adverse events.

This article, written by Chris Funk of the US GS, outlines how the Famine Early Warning Systems Network (FEWS NET) uses satellite data and statistical forecasts to provide early warnings of potential droughts in sub-Saharan Africa.

Funk outlines the role of satellite data in FEWS NET at all stages of the crop-growing season — from scenario building before the season to calculating the water balance during it and assessing yields at the end. Focusing on food security outlooks for East Africa in late 2008, Funk describes how data from NASA's Aqua and QuikSCAT satellites can be used to track moisture and wind conditions over the Indian Ocean and Africa, and how these help anticipate hydrologic conditions in the future to predict shortfalls.

Funk emphasises the need to combine such data with socio-economic analyses of, for example, crop prices, grain stores, political conditions and agricultural inputs. This will help maximise the accuracy and effectiveness of early warnings of drought and food shortages.

This review article describes how remote sensing data can and are being used to map and monitor disasters such as earthquakes, volcanic eruptions, landslides, flooding and wildfire.

The authors summarise the main satellites and sensors used in disaster monitoring and their characteristics. They also discuss in more detail the data and techniques used for individual types of disaster, outlining the advantages and drawbacks to each. In particular, they describe the methods most commonly used to analyse optical, thermal, radar and LiDAR (Light Detection and Ranging) data.

The authors summarise ongoing initiatives using remote sensing data for disaster management, including Sentinel Asia and the International Charter on Space and Major Disasters. Potentially useful emerging systems such as the Disaster Monitoring Constellation are briefly discussed.

This journal article describes the first climate-based model used to predict outbreaks of dengue fever. Researchers from the University of Miami and the University of Costa Rica used climate data and vegetation indices from Costa Rica to predict disease outbreaks with 83 per cent accuracy.

Globally, there are up to 100 million cases of dengue fever, and its more dangerous form, dengue haemorrhagic fever, every year. The spread of dengue fever is set to rise as the world's climate changes. The importance of this model is that it could be used as the basis for an early warning system to prevent the spread of the disease by warning populations that are at risk.

The indices used in the model include variables such as El Niño Southern Oscillations and sea surface temperature, which affect populations of the Aedes aegypti mosquito that spreads the infection.

A population's immunity to disease can greatly affect outbreaks of vector-borne disease, and isolating the influence of climate variability has proven difficult. This research study sets out to evaluate the effect of climate by accounting for population immunity.

The authors collated data on cholera cases from a predominant strain in the rural area of Matlab, Bangladesh, from 1966–2002. They used a model to incorporate immunity from previous infections and also potential cross-immunity from previous infections by other strains. They found that both forms of immunity were long-lasting — over 10 years in some cases. Yet the variation in transmission did not always match variations in immunity; at several points, it coincided with severe weather change such as monsoon rains or river overflow.

The authors suggest that forecasting disease will require considering climate variability alongside population susceptibility.

This article, written by the WHO Rapid Pandemic Assessment Collaboration and published in the journal Science, examines the spread of A(H1N1) influenza, or 'swine flu', and assesses its potential to cause a pandemic.

Analysing surveillance data from Mexico, the authors suggest the geographical spread of swine flu will likely be comparable to other twentieth century pandemics, although the associated impact on human health is difficult to predict.

The authors suggest that the outbreak originated in mid-February 2009 in the village of La Gloria, Veracruz, where over half the population suffered acute respiratory illness. They calculate that the virus transmissibility — the number of cases that one case generates on average — is between 1.4 and 1.6, similar to the transmissibility of previous flu viruses including those that led to the 1918, 1957 and 1968 pandemics. The authors estimate that by 30 April 2009, 6,000–32,000 people will have been infected, with 0.4–1.4 per cent of cases being fatal.

This scientific article, written by researchers at Rice University in the United States, describes how magnetite (iron) nanocrystals — or 'nanorust' — can be used to remove arsenic from contaminated water. The authors describe the discovery of unexpected magnetic interactions between nanoparticles of rust that mean they can be easily extracted from water using a hand-held magnet.

Iron is well known for its ability to bind arsenic and the researchers' experiments show that by suspending the nanoparticles of rust in arsenic-contaminated water, arsenic levels were reduced to well below accepted standards for drinking water.

This commentary, by South African scientists Thembela Hillie and Mbhuti Hlophe, examines nanoscience's potential to solve the technical challenges associated with removing pollutants from water. The authors describe a range of nano-based water treatment technologies already in the marketplace and discuss how nanofiltration membranes can be used in low-cost methods to produce safe drinking water. They highlight a case study in South Africa where such membranes were used to treat brackish groundwater.

The authors emphasise the importance of technology transfer in getting nano-based solutions to the countries that need them, arguing that direct transfer does not often work. Rather, what developing countries need are approaches that combine technology transfer with technology adaptation and adoption — involving local stakeholders in establishing water treatment devices and developing local capacity to use them.

This paper by scientists at the University of Hyderabad examines the nanoscience debate in India. Nanoscience's revolutionary potential and economic benefits are assessed against ethical, legal, social and environmental (ELSE) issues.

The authors present commercial applications, investment, risks and regulatory mechanisms, using the case of Bt cotton in India to show the implications of a new technology. They argue that India's diverse socio-cultural landscape means that nanoscience is likely to have uneven and multilayered effects.

India's scientists do not advocate regulation at the current stage of research — so as not to slow down development, say the authors. But they add that a broad-based and transparent regulatory body to address ELSE issues and funding for research on them would be beneficial.

This article, written by scientists from Canada, China, Egypt and India, examines the spread of alliances in health biotechnology and the extent of collaboration in this sector between the South and the North.

The authors surveyed 288 firms on South–North health biotech collaborations and use the results to map the extent and geography of partnerships. They analyse the international collaborations of firms in Brazil, China, Cuba, Egypt, India and South Africa and compare them to South–South collaborations.

The authors conclude that developing countries' firms are closely tied to northern health biotech networks and that South–North collaborations are common practice in health biotech. More than half the firms surveyed actively collaborate with countries in the North — compared to just a quarter working with other developing countries. Egypt is the only country where South–South collaborations outnumber South–North ones.

These selected proceedings from a regional research seminar in Morocco, hosted by the UN Educational, Scientific and Cultural Organization (UNESCO), examine the state of higher education in Arab states. They highlight the impact of globalisation on local systems and discuss the role of funding agencies in supporting them.

The authors tackle a range of issues including the nature and extent of the 'knowledge gap' in Arab societies, current funding patterns and implications for future support, and the effects of international agreements such as the General Agreement on Trade in Services. Munir Bashshur, member of UNESCO's regional scientific committee for Arab states, presents a summary report of the conference, in both English and Arabic.

This paper examines the relative costs of research in South Africa and the apparent disparity in researchers' salaries. A 2004–2005 research and development survey provides data on the unit cost of research across higher education institutions (HEIs), science councils and the business sector. Analysis shows that research costs and salaries are highest in the business sector and lowest in HEIs, although the differences are not as wide as expected. Similarly, overhead costs are lowest in HEIs and highest in the business sector.

But the authors emphasise that while HEIs may provide the cheapest research — based on cost per hour — this does not mean that they necessarily provide the cheapest 'cost per deliverable', i.e. value to the client.

The authors call for more regular and detailed data to better understand the researcher labour market. They propose an annual salary survey focused on public sector researchers and a common pricing model for all institutions performing public research.

This series of commentaries and papers, published by The Lancet, examines the challenges to achieving a balance between trade and health.

It includes analyses of the WHO and World Trade Organisation (WTO), arguing that they facilitate trade before the health of poor people. Other authors explore issues such as global trade governance, intellectual property rights on life-saving drugs, and how trade practices adversely affect diet and exploit workers.

Richard Smith, from the London School of Hygiene and Tropical Medicine, and colleagues outline an agenda for action to strengthen the evidence on trade and health links, build capacity within health on trade issues and assert health goals in trade policy. They make specific recommendations for the WHO and WTO, donors, governments, nongovernment organisations and academics.

This article, published for The Rockefeller Foundation's conference series 'Making the eHealth Connection', assesses the barriers to quality health information in developing countries, which hamper the development of health systems and services. While the Internet has improved access to health information in developed countries, obstacles remain in developing nations — the most common being unreliable connectivity and expensive Internet access, especially in rural areas.

Other barriers include a lack of medical writing skills; language diversity; copyright issues; economic constraints; poor visibility of scientific outputs from developing countries; low levels of information technology literacy; cultural and lifestyle hurdles and a lack of appropriate public policies and funding.

The authors assess the current status of such barriers and explain how training, open access publishing and recent innovations in Internet access can help. They argue that the digital divide, and its consequent disparities, also exists in pockets within developed countries.

This paper proposes a model to provide better access to fairly priced antiretroviral (ARV) drugs for HIV-infected people in poor countries, while also safeguarding the interests of ARV manufacturers.

The authors explain what governments and brand and generic companies are doing to increase the availability of ARVs in developing countries, taking examples from Brazil, Canada, China, India, the United States and Thailand. They also discuss the implications of creating more South–South partnerships to produce and market ARVs; and the impact that the UNTAID–Clinton Foundation coalition has had on lowering ARV prices in developing countries.

The authors recommend an incentive-based strategy that includes international donors bulk-purchasing generic ARVs, individual governments providing financial relief packages for generic companies, and the WHO brokering negotiations between brand and generic companies.

This series of commentaries and research articles — published by The Lancet, the Peking University Health Sciences Centre and the China Medical Board — addresses China's major health challenges, strategies and future. It has been produced by a group of 63 scientists from 10 countries with Chinese scientists making up two-thirds of the authors.

The research papers give scientific evidence on key health issues including the emergence and control of both infectious and chronic non-infectious diseases in China as well as the performance of China's healthcare system.

Authors of the series' commentaries further discuss a range of topical issues affecting China's health system, including the state of biomedical science and technology (see 'Progress in Chinese biomedicine a massive challenge'), medical research ethics, the lessons learnt from China's schistosomiasis control programme and the challenges the country faces in controlling HIV/AIDS.

The authors of this article analysed simulation results from a regional climate model for the northern Indian Ocean to predict likely changes in the strength and frequency of tropical cyclones in the Bay of Bengal from 2041–2060.

They find that rising concentrations of greenhouse gases will lead to more frequent cyclones in the region, particularly during the post-monsoon period. In addition, the number of intense cyclones and storm surges will increase. These results are consistent with other trend analyses that show intensification of cyclones in the bay during the last century.

But the research described in this paper only deals with simulations from one future climate scenario. To obtain better regional climate projections, the authors suggest it is necessary to examine simulations from more scenarios.

The authors of this article use satellite data to examine trends in the maximum intensities that cyclones can achieve during their lifetimes.

Results from previous analyses of tropical cyclone trends have been questioned due to a lack of consensus regarding data reliability. Moreover results have not been matched to theory because the focus has mainly been on changes in mean tropical cyclone statistics.

In this article, the authors conclusively show significant increases in the maximum wind speeds achieved by the strongest cyclones across all ocean basins except the South Pacific Ocean, with the largest increases occurring over the North Atlantic and northern Indian Oceans.

These findings are consistent with the idea that as seas warm, cyclones become more intense because the ocean has more energy that can be converted to tropical cyclone wind.

This series of five articles outlines new challenges and unsolved problems since the journal's last series in 2005. The first article ([189kB]) predicts the disease burden and economic losses that developing countries would face from chronic diseases such as cardiovascular disease, cancer, chronic respiratory disease, and diabetes. In the 23 countries that the authors incorporated into a model, chronic disease was responsible for 50% of the disease burden in 2005. If no action is taken, they say, about US$84 billion of economic production will be lost from heart disease, stroke, and diabetes alone in these 23 countries between 2006 and 2015. The second article ([105kB]) looks at how to scale-up strategies to fight chronic diseases in developing countries. The authors review evidence to identify which methods are cost-effective and financially feasible, and therefore ready to be scaled-up.

Tobacco control, salt reduction (both of which are detailed in the series' third paper ([177kB])), and a multidrug strategy to treat individuals with high-risk cardiovascular disease (see an in-depth look in paper four ([220kB])) are prime candidates for scaling-up. What effect improving health systems has on the level of chronic diseases should be properly evaluated, say the authors. For some health interventions, such as preventing or controlling diabetes, there is little cost-effectiveness data for low or middle-income countries, but their scientific effectiveness is so compelling that countries should consider how best to incorporate them. The final paper ([92kB]) is a call to action to incorporate existing interventions into healthcare programmes, which in 2005 was costed at US$5.8 billion.

1990 saw the first major effort to estimate the main causes of illness and the biggest killer diseases in different countries. The data are important for public-health officials to allocate their resources wisely but also for feeding into estimates to plan for the future. Importantly, these need to be regularly updated to ensure that health programmes are still going in the right direction. This paper updates the 1990 study and offer predictions up to 2030.

The most forceful change in disease trends is in developing countries, with the proportion of people affected by non-communicable diseases set to increase. Proportionally, the number of people with infectious diseases is set to fall, though not when it comes to HIV/AIDS.

Because the authors also rely on predicting socio-economic development trends, they created best-case and worst-case scenarios for economic growth. In the pessimistic scenario, by 2030, the three leading causes of illness will be HIV/AIDS, depression, and ischaemic heart disease; in the optimistic scenario, road-traffic accidents will replace heart disease as the third leading cause.