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 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, 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.