background: water fl uoride level is unknown in many regions of iran. besides, only few noncontrolled studies world-wide have assessed the effect of water fl uoride on dental fl uorosis and caries. we aimed to measure the fl uoride level of 76 water supplies in 54 cities and evaluate the effect of fl uoride on dental caries and fl uorosis in a large multi-project study. materials and methods: i...

water resources suitability is one of the most important factors to sustainabilityutilization of natural potential by rangeland grazing suitability. to determine this factor inshort time, low cost and high accuracy are most challenges of experts and ranchers. usingsuitable technique for this subject can be sustainable utilization comprising from rangelandecosystems according to its degradation ...

introduction: a total dissolved solid (tds) is an important indicator for water quality assesment. since the composition of mineral salts and discharge affects the tds of water, it is important to understand the relationships of mineral salts composition with tds. materials and methods: in this study, methods of artificial neural networks with five different training algorithm,levenberg-marquar...

Objective: To see if drinking water, when mildly hypohydrated (a loss of 0.7% of body mass), helps to maintain cognitive functioning and mood and to explore underlying mechanisms. Method: 118 (61 male) young adults were exposed to a temperature of 30oC for four hours and either did or did not drink two 150ml glasses of water during that time. On three occasions, once at baseline and once after ...

introduction: ground water as a dynamic and recyclable natural resource in fractured rock terrains are characterized by single and double fracture porosity models. due to the heterogeneous nature of the medium hydraulic properties of these rocks are mainly controlled by fracturing and influenced by multivariate parameters. this heterogeneity is due to various compactions , density of fractures ...

This paper investigates the effect of drinking arsenic contaminated water on mental health. Drinking water with an unsafe arsenic level for a prolonged period can lead to arsenicosis and associated illness. Based on rich and newly collected household survey data from Bangladesh, we construct several measures for arsenic contamination that include the actual arsenic level in the respondent’s tub...

An increasing scarcity of water for crop farming and livestock watering among agropastoralists of Mieso in Eastern Ethiopia has largely disrupted their livelihoods. Indigenous water well maintenance and government initiated rainwater harvesting are two important collective actions common among these communities. With the aim of examining collective action institutions in both cases, we collecte...

Using NASA Moderate Resolution Imaging Spectroradiometer aerosol optical depth and total cloud cover retrievals, CloudSat-CALIPSO cloud profiles, and a database of extratropical cyclones and frontal boundary locations, relationships between changes in aerosol optical depth and cloud cover in extratropical cyclones occurring over Northern Hemisphere oceans are examined. A reanalysis data set is ...

This paper studies Canberra households’ and businesses’ willingness to pay (WTP) to avoid drought water restrictions, using stated choice experiments. We find that customers evidence a lack of WTP to avoid most types of drought-induced restrictions. Respondents appear unwilling to pay to avoid low-level restrictions at all and to avoid higher levels of restrictions that are not in place every d...