ABSTRACT
To understand the relations between land use allocation and water quality preservation within a watershed is essential to assure sustainable development. The land use and land cover (LUC) within Zêzere River watershed registered relevant changes in the last decades. These land use and land cover changes (LUCCs) have impacts in water quality, mainly in surface water degradation caused by surface runoff from artificial and agricultural areas, forest fires and burnt areas, and caused by sewage discharges from agroindustry and urban sprawl. In this context, the impact of LUCCs in the quality of surface water of the Zêzere watershed is evaluated, considering the changes for different types of LUC and establishing their possible correlations to the most relevant water quality changes. The results indicate that the loss of coniferous forest and the increase of transitional woodland-shrub are related to increased water's pH; while the growth in artificial surfaces and pastures leads mainly to the increase of soluble salts and fecal coliform concentration. These particular findings within the Zêzere watershed, show the relevance of addressing water quality impact driven from land use and should therefore be taken into account within the planning process in order to prevent water stress, namely within watersheds integrating drinking water catchments.
Subject(s)
Environmental Monitoring , Water Supply/statistics & numerical data , Agriculture , Conservation of Natural Resources , Portugal , Urbanization , Water QualityABSTRACT
AIMS: To assess the presence of viral pathogens in bathing water samples and to evaluate the interdependency of bacterial indicator counts and viral detection. METHODS AND RESULTS: Bathing water samples of 16 beaches collected along a Portuguese Coastal area were screened for the hepatitis A virus (HAV) and norovirus genogroup I (NVGI) using RT-PCR technique. Bacteriological water quality was also assessed, according to European regulations. HAV and NVGI were detected in 95% and 27% of the water samples, respectively, whereas bacteriological quality was good in all but one sample, according to current water quality regulations. CONCLUSIONS: All water samples would be considered of excellent quality according to the most recent European regulations. No relationship between viral detection and regulatory-based bacterial indicators was found. SIGNIFICANCE AND IMPACT OF THE STUDY: The current results reinforce the importance of increased surveillance for pathogenic viruses in bathing waters.
Subject(s)
Bacteria/isolation & purification , Hepatitis A virus/isolation & purification , Norovirus/isolation & purification , Seawater/microbiology , Seawater/virology , Water Microbiology , Bathing Beaches , Environmental Monitoring , Portugal , RNA, Viral , Reverse Transcriptase Polymerase Chain Reaction , Water Pollutants/isolation & purificationABSTRACT
Increased energy expenditure often occurs during illness or after injection of endotoxin and can contribute to the generation of fever. In laboratory rats and mice the thermogenic response has been attributed to the sympathetic activation of brown adipose tissue (BAT), although mice often fail to show pyrexia. In this study the effects of malaria on O2 consumption and BAT were studied in mice inoculated with Plasmodium berghei. Parasitemia was maximal (greater than 50% of erythrocytes showing positive Leishman staining) 72 h after inoculation. Up to this time body weight and food intake were similar to values for control mice, although colonic temperatures were slightly depressed in infected mice. Thereafter, infected mice showed marked hypophagia, loss of body weight, and severe hypothermia; colonic temperature was less than 31 degrees C at 96 h when the experiment was terminated. Resting O2 consumption (VO2) measured at 24 degrees C was slightly elevated in infected mice 12 h after inoculation and reached a peak value (31% above controls) at 48 h. VO2 returned to the same value as controls at 96 h. In vitro thermogenic activity of BAT (assessed from binding of guanosine diphosphate to isolated mitochondria) was not significantly altered in infected mice. These data demonstrate a marked thermogenic response to malarial infection, but this is not accompanied by fever in mice and is dissociated from stimulation of BAT activity.
Subject(s)
Adipose Tissue, Brown/physiopathology , Malaria/physiopathology , Oxygen Consumption , Animals , Body Temperature Regulation , Energy Metabolism , Guanosine Diphosphate/metabolism , Male , Mice , Mitochondria/metabolism , Plasmodium bergheiABSTRACT
The changes in core temperature induced by low (5 mg/kg) and high (40 mg/kg) doses of morphine were compared in Wistar and Sprague-Dawley rats. In Sprague-Dawley rats the low dose caused a hyperthermia and the high dose a hypothermia but in Wistar rats both doses caused a hyperthermia. In either case the change in core temperature was antagonized by naloxone (2 mg/kg). Tolerance to the effects of the high dose of morphine developed in both strains of rat. Dextromoramide (3.75 and 15 mg/kg) also had an effect on core temperature, but in this case the responses of the strains were opposite to those seen with morphine. Laevomoramide was relatively ineffective. Naloxone (2 mg/kg) had no effect on the ability of rats of either strain to withstand heat or cold stress, providing no evidence that endogenous morphine-like substances have a physiological role in thermoregulation.
