Posts filed under ‘science’
Translation: reducing water contamination using solar energy
Arsenic and other minerals have been removed from river water using solar power by a team of Peruvian and Chilean researchers.
Researchers from Peru’s National Engineering University and Chile’s Tarapacá University have photochemically purified water from the river Locumba near Tacna, a Peruvian town by the border with Chile.
The decontaminated water is used for agricultural irrigation, though depending on the level of decontamination achieved it could be used for human consumption in future.
The technology’s ease of use means it could be used in the countries involved with the research as well as Bolivia; Andean countries where natural contamination is present in many waterways.
Juan Rodríguez, coordinator of the research in Peru, told SciDev.Net that the technology is able to reduce high levels of arsenic contamination of currently 500 parts per billion (ppb) to about 30 ppb.
The researchers designed prototypes of electrochemical equipment and decontamination filters for use in rural or difficult to access areas, which for the moment can treat 20 cubic metres of water daily.
“Modular systems can process much higher volumes, so that’s what we’re trying to achieve,” Rodríguez said.
They used a photochemical system with tubes of glass or plastic to decontaminate the water. Based on reflections the tubes get solar radiation for a few hours, which can purify water contaminated with arsenic and make it suitable for consumption.
This system can also decontaminate boron and iron from water, as sunlight accelerates the rate at which minerals coagulate and can then be removed.
According to Rodríguez, this research is of importance for Bolivia, Chile and Peru because “the problem of arsenic in waterways is of natural origin and doesn’t distinguish between borders”.
This is my translation of a story written by Zoraida Portillo on the Science and Development Network, “Reducen contaminación por arsénico usando energía solar”, published on August 3, 2010. You can read the original in Spanish here.
SciDev.Net stories are published under a Creative Commons attribution license; my translation is available under the same license. Note this license is only for this page. Other works on this website are subject to other licenses; please contact me for details if you’d like to republish other parts of this site.
Translation: Environmental exposure impacts antibiotic resistance in children:
Exposure to antibiotics at home and in the broader environment influences the risk of children carrying antibiotic-resistant Escherichia coli bacteria, according to a study published in the The American Journal of Tropical Medicine and Hygiene.
The study was based in four areas of Peru with poor health systems, where antibiotics are used indiscriminately and without prescription. It covered coastal, mountain and jungle environments and focused on children between the ages of three months and three years.
The study suggests that environmental exposure to antibiotic-resistant E. coli can be as important as the consumption of antibiotics, according to the paper’s principal author, Henry Kalter, from the School of Public Health at Johns Hopkins University.
A risk factor at home was the use of antibiotics by other family members. The study demonstrated that children who hadn’t taken particular antibiotics themselves still carried bacteria resistant to them.
At the community level, living in a place where many families raised chickens themselves was a protective factor against the transport of antibiotic-resistant bacteria. According to Kalter, high consumption of home-raised chickens probably protects a community against exposure to antibiotics. He contrasted home-raised chickens with market-bought chickens, which may be given high doses of antibiotics and therefore have high levels of antibiotic-resistant E. coli.
“An important aspect of our conclusions is that the protective effect was not due to the fact that the children were eating certain types of chicken; rather that their communities were,” he said.
Kalter suggested that communities consuming more chickens raised at home presumably had less resistant bacteria in the environment, such as in open sewers and uncovered wells.
“This study reinforces the message that exposure to antibiotics leads to the development of antibiotic resistance, by studying the role of different types of exposure on small children carrying of antibiotic-resistant E. coli,” he continued.
According to Kalter, examining these factors provides a better understanding of how antibiotic resistance spreads in the developing world.
“These findings suggest that unnecessary use of antibiotics in humans and animals should be minimised as much as possible,” he added.
“Many tons of the antibiotics consumed each year on the planet are given to stock animals. This study demonstrates that this use has a very real cost to human health,” Edward T. Ryan, president of the American Society of Tropical Medicine and Hygiene, said in a press release from Johns Hopkins University.
The study was run by the Johns Hopkins University School of Public Health, the Peruvian charity PRISMA and the infectious disease laboratory of the Cayetano Heredia University in Peru.
The original paper in The American Journal of Tropical Medicine and Hygiene is here.
This is my translation of a story written by Zoraida Portillo on the Science and Development Network, “Antibióticos propician resistencia infantil a E. coli”, published on June 14, 2010. You can read the original in Spanish here.
SciDev.Net stories are published under a Creative Commons attribution license; my translation is available under the same license. Note this license is only for this page. Other works on this website are subject to other licenses; please contact me for details if you’d like to republish other parts of this site.
still south but north, video editing
I grew up in the southern state of a country in the Southern Hemisphere, South Australia. No geography confusion there. At the moment I’m living in the northernmost region of another country in the same hemisphere, which means I’m living in the north, even though for most of the world with internet access it’s still the south. However from my perspective, and that of Chileans, Arica is a northern extremity. It’s also extreme thanks to its exceptionally dry climate, which trumps that of my home town, Adelaide, which is also noted for aridity.
Arica is also an interesting place to be right now because Chile’s president, Sebastián Piñera, popped up this week for a celebration. The occasion was the day during the War of the Pacific (not to be confused with the Pacific War), when Chile took this region from Peru. Or more specifically, a big rock by the beach in Arica.
You might ask what I’m doing here, besides brushing up on South American history and international relations and taking South American Spanish classes. Despite reaching intermediate level in Spain, I needed classes because the language on this continent is different. So much so that I’m reading a book called “How to survive in the Chilean jungle,” which is not a guide to a jungle at all (I’m on the edge of the Atacama Desert), but rather the vocabulary unique to this skinny but vast nation.
As well as polishing my thesis I’ve been editing on a series of videos. They’re for one of the research institutes based at the University of Adelaide I’ve worked with before, the Australian Centre for Plant Functional Genomics. You can see one here. I filmed the content before I left the country. I have my camera with me, so you can expect content from South America down the track.
Being seen, not published…
I continue to lament the lack of the ‘published high’ I get from journalism while I work on my MPhil. However I’m emerging from this academic fugue for two conferences next month.
Firstly I’m heading to Canberra to present at the Australian Science Communicators conference, among other things. One of those other things is an interview – in Spanish – at the Chilean consulate, to get a working holiday visa for my move there at the end of April. You can keep up to date with that on my travel blog.
After Canberra I’ll return to Adelaide to volunteer at the Australian International Documentary Conference, following my fantastic adventure at WCSFP (the subject of my previous post). I wrote a roundup of my highlights from the WCSFP on my Nature blog, which has been woefully neglected since.
In Canberra I’ll be talking about how to avoid preaching to the converted in science engagement, as well as being part of a panel discussion on “Tools for Democracy and Dialogue”. This is the summary of my presentation:
Events aimed at public engagement with science often attract the same crowd.
They’re sometimes planned with little consideration for who will participate, beyond sheer numbers. So rather than representing a broad public, outcomes may represent people with above average interest in science and, studies suggest, socioeconomic status and education to match.
This raises issues of equality, and can limit the value of feedback from such events. As part of my research, I’ve looked at different ways participants have been recruited and what implications this has for outcomes of public engagement with science.
Scientists closer to developing salt-tolerant crops
An international team of scientists has developed salt-tolerant plants using a new type of genetic modification (GM), bringing salt-tolerant cereal crops a step closer to reality.
The research team – based at the University of Adelaide’s Waite Campus – has used a new GM technique to contain salt in parts of the plant where it does less damage.
Salinity affects agriculture worldwide, which means the results of this research could impact on world food production and security.
The work has been led by researchers from the Australian Centre for Plant Functional Genomics and the University of Adelaide’s School of Agriculture, Food and Wine, in collaboration with scientists from the Department of Plant Sciences at the University of Cambridge, UK.
The results of their work were published recently in the top international plant science journal, The Plant Cell.
“Salinity affects the growth of plants worldwide, particularly in irrigated land where one third of the world’s food is produced. And it is a problem that is only going to get worse, as pressure to use less water increases and quality of water decreases,” said the team’s leader, Professor Mark Tester, from the School of Agriculture, Food and Wine at the University of Adelaide and the Australian Centre for Plant Functional Genomics (ACPFG).
“Helping plants to withstand this salty onslaught will have a significant impact on world food production.”
Professor Tester said his team used the technique to keep salt – as sodium ions (Na+) – out of the leaves of a model plant species. The researchers modified genes specifically around the plant’s water conducting pipes (xylem) so that salt is removed from the transpiration stream before it gets to the shoot.
“This reduces the amount of toxic Na+ building up in the shoot and so increases the plant’s tolerance to salinity,” Professor Tester said.
“In doing this, we’ve enhanced a process used naturally by plants to minimise the movement of Na+ to the shoot. We’ve used genetic modification to amplify the process, helping plants to do what they already do – but to do it much better.”
The team is now in the process of transferring this technology to crops such as rice, wheat and barley.
“Our results in rice already look very promising,” Professor Tester said.
This story was written with David Ellis and published in Adelaidean magazine.
