Milk better than water to rehydrate kids, study finds

Active children need to be watered with milk. It’s a more effective way of countering dehydration than a sports drink or water itself, say researchers at McMaster University.

McMaster University graduate student Kim Volterman monitors research participant Paige Leonard’s heart rate in the climate chamber at the Children’s Exercise and Nutrition Centre of McMaster University and the McMaster Children’s Hospital.

That’s particularly important during hot summer weather, says Brian Timmons, research director of the Child Health and Exercise Medicine Program at McMaster and principal investigator of the study.

“Children become dehydrated during exercise, and it’s important they get enough fluids, particularly before going into a second round of a game. Milk is better than either a sports drink or water because it is a source of high quality protein, carbohydrates, calcium and electrolytes.” Read more

Water and Radiation on Saturn’s Moon Enceladus Can be Conditions for Life

Specialists of the University of Texas at San Antonio (USA) have found that microorganisms can live in water that has been exposed to radiation. Suitable conditions are on several celestial bodies, including Enceladus, the satellite of Saturn.

The source of radioactive radiation on Enceladus can be rocks that are close in composition to chondrites – the most common type of meteorites that contain uranium, potassium and thorium. And the existence of the oceans of water on Enceladus is very likely. Read more

Water balance creates a threshold in soil pH at the global scale

Soil pH regulates the capacity of soils to store and supply nutrients, and thus contributes substantially to controlling productivity in terrestrial ecosystems.

However, soil pH is not an independent regulator of soil fertility—rather, it is ultimately controlled by environmental forcing. In particular, small changes in water balance cause a steep transition from alkaline to acid soils across natural climate gradients.

Although the processes governing this threshold in soil pH are well understood, the threshold has not been quantified at the global scale, where the influence of climate may be confounded by the effects of topography and mineralogy. Here we evaluate the global relationship between water balance and soil pH by extracting a spatially random sample (n = 20,000) from an extensive compilation of 60,291 soil pH measurements. Read more

Sour taste cells detect water

New research from Caltech shows that sour-sensing taste cells play an important role in detecting water on the tongue.

The work, appearing in a paper in the May 29 issue of the journal Nature Neuroscience, was done in the laboratory of Yuki Oka, assistant professor of biology.

“The tongue can detect various key nutrient factors, called tastants — such as sodium, sugar, and amino acids — through taste,” says Oka. “However, how we sense water in the mouth was unknown. Many insect species are known to ‘taste’ water, so we imagined that mammals also might have a machinery in the taste system for water detection.”

Taste cells relay information about tastants to the brain via nerves called the taste nerves. First author and graduate student Dhruv Zocchi measured the electrical responses from taste nerves in mice to various tastants as well as to water. The nerves responded in predictable ways to different basic tastes — sweet, sour, bitter, salty, and umami — but they were also stimulated by pure water. “This was exciting because it implied that some taste cells are capable of detecting water,” Zocchi says. Read more

High-resolution mapping of global surface water and its long-term changes

The location and persistence of surface water (inland and coastal) is both affected by climate and human activity and affects climate, biological diversity and human wellbeing. Global data sets documenting surface water location and seasonality have been produced from inventories and national descriptions, statistical extrapolation of regional data8 and satellite imagery, but measuring long-term changes at high resolution remains a challenge.

Here, using three million Landsat satellite images, we quantify changes in global surface water over the past 32 years at 30-metre resolution. We record the months and years when water was present, where occurrence changed and what form changes took in terms of seasonality and persistence. Between 1984 and 2015 permanent surface water has disappeared from an area of almost 90,000 square kilometres, roughly equivalent to that of Lake Superior, though new permanent bodies of surface water covering 184,000 square kilometres have formed elsewhere. Read more