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A Local, Inexpensive Way to Purify Water In Developing Countries

The World Health Organization estimates that lack of access to clean drinking water causes 1.6 million deaths each year, mostly from diarrheal and parasitic diseases. Because of this, importing disinfecting chemicals is a priority for many developing nations. But what if instead they could rely on inexpensive, local means to turn contaminated water into potable, purified water?

A team of researchers led by Stephanie Butler Velegol, an environmental engineering instructor at Penn State, are looking to the past for water-purifying techniques they might be able to adapt for today. One possibility: the Moringa oleifera tree, a common food source in tropical and subtropical regions. But in addition to the edible seedpods, seeds, leaves, roots and flowers, locals in the areas where it grows also make use of the Moringa oleifera for its bacteria-killing properties. As far back as ancient Egypt, crushed Moringa seeds were rubbed on clay pots to purify the water inside; for many years dried powder from the crushed seeds has been used as a handwash.

The process works via a positively-charged protein called the Moringa Oleifera Cationic Protein (MOCP), which kills dangerous water-borne bacteria by causing their cell membranes to fuse. However, because the organic matter remains in the water, the protein continues to provide a food source to any bacteria not destroyed, allowing the water to become re-infected again in a matter of days. A 2012 paper proposed a solution to this by a suggesting a process during which the MOCP was attached to grains of sand, which could be easily removed from the purified water, washed and then used again.

More recent studies have examined when seeds should be harvested for the most bacteria-fighting potency. Researchers teamed with Bashir Abubakar, a botanist from Ahmadu Bello University in Zaria, Nigeria to study the effectiveness of seeds in different seasons, and found that the extracted protein of mature dried seeds collected in the rainy season is most effective, followed by mature dried seeds collected in the dry season.

If the seeds prove viable on a large scale, Moringa oleifera tree plantations could also help boost local economies. What's more, the less money spent on importing chemical purifiers, the more funds will be available for infrastructure and other social needs.

[h/t Penn State]

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Sleeping In on Weekends May Help You Catch Up on Sleep After All
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Weekend mornings are a precious time for nine-to-fivers. If you spend your weekdays staying up long past reasonable bedtime hours and waking up with the Sun, you may be tempted to sleep past noon every day off you get. Sleeping in feels great, and now a new study from sleep scientists at Stockholm University's Stress Research Institute finds that it may also be an effective way to make up for the sleep you missed during the week, contradicting previously held beliefs on the matter.

According to most sleep researchers, the only way to catch up on sleep debt is to adjust your sleeping patterns gradually over time—in other words, cramming in all the sleep you missed last week into a night or two won't cut it. A team of scientists reexamined this theory for their study published in the Journal of Sleep Research [PDF]. Researchers looked at the sleep data from about 44,000 Swedish adults collected in 1997 and followed up with the participants 13 years later. Accounting for factors like age, gender, and education, they report that adults who consistently slept for five hours or fewer throughout the week were more likely to have died after those 13 years than subjects who slept for six or seven hours, seven days a week. Oversleeping every day of the week also put participants at a greater risk of mortality.

But there's good news for people who do all their sleeping in on the weekend—subjects who under-slept five days and slept more during the last two days of the week had no greater risk of death than the people who got healthy amounts of sleep every night of the week. The results call into question past sleep studies that have only looked at sleep patterns during the week, ignoring weekend behaviors. The new study, though, focuses just on the sleeping habits of people at a specific point in time. To confirm what these results suggest, more long-term studies will need to be conducted.

Earlier mortality isn't the only health risk associated with unsatisfactory sleep habits: Getting too little or poor-quality sleep can mess with your memory, appetite, and cognitive and motor performance. That means finding time to get a good night's sleep, no matter the day of the week (if you're lucky enough to have the option), is still the healthiest course of action.

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People With Type A Blood Are More Prone to Severe Diarrhea
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Bad news for people with type A blood who also love to eat at buffets: A new study spotted by Science News reveals that people with this particular blood type have a significantly higher risk of contracting severe diarrhea from a common bacterial pathogen.

Researchers at the Washington University School of Medicine discovered that a protein secreted by a strain of Escherichia coli latches onto sugar molecules that are only found within the blood cells and intestinal lining of people with type A blood.

For the study, 106 healthy volunteers drank water that contained a strain of the bacterium E. coli—one of the major causes of infectious diarrhea around the world. Only 56 percent of volunteers with blood types O and B contracted moderate to severe diarrhea, but 81 percent of volunteers with blood types A or AB fell ill. All participants were later given antibiotics.

Researchers say these findings, which were published in the Journal of Clinical Investigation, could aid the development of an effective vaccine. Developing parts of the world are particularly susceptible to E. coli contamination, which causes millions of infections and hundreds of thousands of deaths each year, researchers note.

As anyone who has ever had "Delhi belly" can attest, this is also a concern for people who travel to developing regions. The main causes of E. coli infection are contaminated food and water, so it's wise to regularly wash your hands and avoid eating raw produce and undercooked beef while traveling.

[h/t Science News]

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