Although nutritionists have long been aware of the importance of clean drinking water and sanitation, water is becoming part of the international political agenda only after a slow realization of its scarcity. This is mainly because water has been taken for granted in industrialized countries except during periods of drought. in many areas of developing countries, water shortages already exist. Even with improved management, new sources of water will have to be developed at higher costs per project. Provision of clean water and sanitation has been rendered difficult by rapid urbanization since the middle of the twentieth century. Although cities have managed to provide a water supply, they have not been able to provide sewage and wastewater treatment. Meanwhile, irrigated agriculture uses nearly 70% of world water. in the future, food security will become even more dependent on irrigation. Poor management, due mostly to low salaries and political interference, is one of the main reasons for inefficient water systems. Underpricing of water in towns and on farms discourages conservation. Furthermore, people who do not have access to tap water in developing countries pay 10 times more than those who have taps.

Non-PR | IFPRI4 | EPTD

Hummingbirds are specialized nectarivores that feed on dilute solutions of sugars with trace amounts of amino acids and electrolytes. Their diets contain excess water that, if absorbed, must be eliminated. It has been hypothesized that in hummingbirds only a small fraction of this dietary water may be absorbed in the intestine. Here, we report the results of experiments designed to examine the relationship between nectar intake and water turnover in hummingbirds. Our results also allow the estimation of water absorption across the intestine and therefore test the hypothesis that ingested water in hummingbirds passes largely unabsorbed through the gastrointestinal tract. We found that fractional and total water turnover increased linearly with water ingestion. At low sucrose concentrations, food intake rates between four and five times body mass per 12 h were not unusual. A simple mass-balance model suggested that 78 % of ingested water was absorbed in the gastrointestinal tract and hence must be processed by the kidneys. However, fractional water absorption was variable and did not appear to be correlated with food or water intake parameters. Our results do not lend support to the hypothesis that the bulk of dietary water passes through the intestine unabsorbed. Although hummingbird kidneys appear well suited to excrete large volumes of dilute urine, rates of energy assimilation in hummingbirds may be constrained by excess water elimination when these birds are feeding on nectars with a low sugar concentration. | T.J. McWhorter and C. Martinez del Rio

As for oily water treatment in food industries, the membrane technology has a large potential to reduce the operation time, equipment space and total costs. Using crude lecithin/water emulsion as a model of oily waste water, filtration characteristics on the flux and total organic carbon (TOC) rejection were investigated with a wide range of membranes in reverse osmosis, nanofiltration, ultrafiltration, and microfiltration. Constant flux and TOC rejection were obtained in crossflow filtration with hydrophilic membranes having smaller pores than the emulsion droplets (1-2 mum). Free phospholipids were removed with reverse osmosis membranes or nanofiltration membranes having high NaCl rejection abilities. When microfiltration membranes having larger pores than the emulsion droplets were used, the membrane characteristics such as the pore structure and hydrophobicity largely affected the filtration characteristics: asymmetric membranes gave relatively high fluxes when its loose side was used against the feed emulsion as a depth filter, symmetric membranes having a spongoid pore structure and a pore size similar to the emulsion droplets brought about almost 0 flux owing to an extreme progress of pore blocking, hydrophobic membranes of adequate pore sizes showed a possibility to result in the negative TOC rejection

Foraging behaviour of gregarious Mediterranean water shrew Neomys anomalus was investigated in 7 individuals. Shrews were tested individually and in a 4-animal-group in a terrarium. Shrew behaviour was recorded in darkness using 2 infra-red sensitive video-cameras. Two experimental variants, with and without natural structures in the terrarium, were established. When foraging individually, N. anomalus consumed only few food portions at the places of finding. Shrews hoarded most food in the nest and/or in hiding-places and ate it under cover. The presence of natural structures caused hoarding and eating of food in scattered hiding-places, instead of carrying it to the nest. During group foraging, N. anomalus did not hoard food communally, and preparation of individual stores almost ceased. In all tests, they ate successively more food items at the places of finding as the duration of foraging increased.