188,209 research outputs found
Mobility of heavy metals from tailings to stream waters in a mining activity contaminated site
No full textIn this paper the results of a recent characterization of Rio Piscinas (SW of Sardinia, Italy) hydrological basin are reported. In such area (about 50 km2), previous mining activities caused a serious heavy metal contamination of surface waters, groundwater, soils and biota. Acid mine drainage phenomena were observed in the area. The main sources of contamination are the tailings stored in mine tunnels and abandoned along fluvial banks. A methodological approach was adopted in order to identify relations between tailings and water contamination. Representative samples of tailings and stream sediments samples were collected. XRD analyses were performed for mineralogical characterization, while acid digestion was carried out for determining metal contents. Batch sequential leaching tests were performed in order to assess metal mobility. Also groundwater and stream water were sampled in specific locations and suitably characterized. All information collected allowed the understanding of the effect of tailings on water contamination, thus contributing to the qualitative prediction of pollution evolution on the basis of metal mobility. Finally, a potential remediation strategy of stream water is proposed
The brain as a target of hormonal contraceptives: Evidence from animal studies
No full textHormonal contraceptives are frequently prescribed drugs among women, mainly for their reversible contraceptive purposes but also for beneficial effects in some gynecological pathologies. Despite extensive studies aimed at elucidating the physical effects of hormonal contraceptives and ameliorating some unwanted outcomes, little is known yet about the effects of these drugs on brain function and related behavior, which are known to be modulated by endogenous steroid hormones. We describe the current literature on preclinical studies in animals undertaken to investigate effects of hormonal contraceptives on brain function and behavior. These studies suggest that hormonal contraceptives influence neurohormones, neurotransmitters, neuropeptides, and emotional, cognitive, social and sexual behaviors. Animals allow examination of the basic biological mechanisms of these drugs, devoid of the psychological aspect often associated to hormonal contraceptives' use in women. Understanding the neurobiological effects of these drugs may improve women's health and may help women making informed choices on hormonal contraception
Eating disinhibition and food liking are influenced by variants in CAV1 (caveolin 1) gene
No full textEating behavior is influenced by a combination of environmental and genetic factors. Although candidate gene studies have been conducted, much remains to be understood about genetic influences. Therefore, we conducted a Genome-Wide Association Study (GWAS) aims to identify new variants that influence eating disinhibition. Moreover, we test the possible association of these variants with food liking and metabolic phenotypes.We measured disinhibition in two cohorts of Italian samples using three selected statements from the Three Factor Eating Questionnaire. Personal and clinical data were collected, as well as liking for different foods and beverages. GWAS was carried out in 1124 individuals; then the best signals (p-value < 1 x 10(-5)) were studied for replication in 426 independents participants. To study the link of eating disinhibition and associated variants with food liking and metabolic traits, we used linear mixed models and Structural Equation Modeling (SEM).A significant association with CAV1 (caveolin 1) gene (p < 5 x 10(-8)) was identified. The top SNP (rs6961694) resulted also associated with the liking for sweet foods and alcoholic beverages (p-value < 0.05). Moreover, we observed significant eQTL associations between this SNP and CAV1 expression levels in human tissues such as adipose subcutaneous tissue, pancreas and brain hippocampus (p-value = 0.00022, 0.00015 and 0.017, respectively). Although higher values of BMI, waist, hips and triglycerides were significantly associated with increasing eating disinhibition (p-value < 0.05), no association emerged between the rs6961694 SNP and anthropometric or lipids phenotypes.In conclusion, we describe a significant association between eating traits and CAV1 gene, providing new knowledge on the link existing between genetics, eating behaviour and health status
Total content, chemical and mineralogical forms and mobility/bioavailability of heavy metals in soils and sediments in the Rio San Giorgio basin (Iglesias-Gonnesa, southwestern Sardinia, Italy)
No full textIntegration of combined cycle power plants and parabolic solar troughs using CO2 as heat transfer fluid
No full textIn this paper, a performance assessment of integrated solar combined cycle systems (ISCCS) is reported on. The main aim of the study was to evaluate the solar conversion efficiency of ISCCS plants based on parabolic troughs using CO2 as heat transfer fluid. The use of CO2 instead of the more conventional thermal oil as heat transfer fluid can allow an increase in the trough outlet temperature and thus in solar energy conversion efficiency. In particular, the ISCCS plant considered here was developed on the basis of a triple-pressure, reheated combined cycle power plant rated at 252 MW. Two different solutions for the solar steam generator are considered and compared. Moreover, the performance of the ISCCS system was evaluated with reference to different values of CO2 maximum temperature, solar radiation and solar share of the power output.
The results of the performance assessment show that the solar energy conversion efficiency ranges from 23% to 25% for a CO2 maximum temperature of 550°C. The use of a CO2 temperature of 450°C reduces the solar efficiency by about 1.5-2.0 percentage points. The use of a solar steam generator including only the evaporation section instead of the preheating, evaporation and superheating sections allows the achievement of slightly better conversion efficiencies. However, the adoption of this solution leads to a maximum value of the solar share around 10% on the ISCCS power output. The solar conversion efficiencies of the ISCCS systems considered here are better than those of the more conventional Concentrating Solar Power (CSP) systems based on steam cycles (14-18%) and are very similar to the predicted conversion efficiencies of the more advanced direct steam generation plants (22-27%)
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Investigation of the link between PROP taste perception and vegetables consumption using FAOSTAT data
No full textIn this work we investigated, in populations located in Central Asia, the relationship between PROP taste perception and vegetables liking and consumption using FAOSTAT dataset. Collected data were analysed using distance matrices, Mantel test and Pearson correlation. Populations showing similar ability in tasting PROP bitterness are more similar as respect to vegetable consumption (r = 0.63, p-value =.05). Moreover, a significant negative correlation was found between the percentage of Non Taster (NT) in different countries and the percentage of vegetable consumption (r = −0.87, p-value =.02), while a significant positive correlation emerged between the percentage of Super Taster (ST) and the percentage of vegetable liking (r = 0.87, p-value =.02). In our work we showed that differences in bitter perception among populations contributes to differences in vegetable liking and vegetable consumption. More in detail, populations with higher percentage of ST consume more vegetables than population where the majority of individuals are NT
Failure of acute ethanol administration to alter cerebral cortical and hippocampal allopregnanolone levels in C57BL/6J and DBA/2J mice
No full textAcute ethanol administration to rats stimulates the hypothalamic-pituitary-adrenal (HPA) axis and increases brain and plasma levels of the potent neurosteroid allopregnanolone. Increased allopregnanolone levels contribute to the anxiolytic, anticonvulsant, sedative and pro-aggressive actions of ethanol. It is not yet known if ethanol’s effects on allopregnanolone levels generalize across species. Indeed, studies in mice have reported that ethanol does not always alter brain and plasma allopregnanolone levels We thus explored the effects of ethanol administration on brain levels of allopregnanolone and its precursor progesterone in C57BL/6J and DBA/2J mice, two inbred strains with different sensitivity to behavioral effects of alcohol.
Male C57BL/6J and DBA/2J mice were injected with ethanol (1, 2, 3 or 4 g/kg, i.p.) or saline and were sacrificed 1 hour later or 15, 30, 60 and 120 minutes later for the time course studies. Allopregnanolone, progesterone and corticosterone levels were measured by radioimmunoassay in cerebral cortex and hippocampus.
Acute ethanol administration did not alter cerebral cortical and hippocampal levels of allopregnanolone and progesterone in both C57BL/6J and DBA/2J mice at any of the doses examined. Cerebral cortical levels of allopregnanolone and progesterone were also not altered at any of the time points examined in either strain. Acute ethanol administration dose-dependently increased corticosterone levels in the cerebral cortex and the hippocampus of both mouse strains. In C57BL/6J mice, corticosterone levels were increased by 319%, 352% and 448% in the cerebral cortex and by 284%, 218% and 368% in the hippocampus at the doses of 2, 3 and 4 g/kg, respectively, p<0.001. In DBA/2J mice, corticosterone levels were increased by 354%, 417%, 447% and 574% in the cerebral cortex and by 259%, 434%, 567% and 629% in the hippocampus at the doses of 1, 2, 3 and 4 g/kg, respectively, p<0.001. The effect of ethanol on cerebral cortical corticosterone levels was also time-dependent: in C57BL/6J mice it was apparent at 15 min (+155%), reached a peak at 60 min (+306%) and remained elevated at 120 min (+217%) from ethanol administration (p<0.001); in DBA/2J mice it was apparent at 30 min (+546%), reached a peak at 60 min (+1002%) and remained elevated at 120 min (+822%) from ethanol administration (p<0.001). These results suggest that ethanol administration is activating the HPA axis, as expected, and that ethanol might directly impair brain neurosteroid synthesis. Moreover, to evaluate if the effect of ethanol on allopregnanolone levels was specific to ethanol or not, we tested whether administration of morphine, which also increases cerebral cortical levels of allopregnanolone in rats, alters allopregnanolone and progesterone levels in male C57BL/6J and DBA/2J mice. Morphine administration increased cerebral cortical allopregnanolone levels in C57BL/6J mice (+77%, +93% and +88%, at the doses of 5, 10 and 30 mg/kg, respectively, p<0.01) and DBA/2J mice (+81% at the dose of 5 mg/kg, p<0.05). Morphine administration also increased progesterone levels in both strains. These results suggest that the impairment in brain neurosteroidogenesis in C57BL/6J and DBA/2J mice appears to be specific to ethanol.
Overall, these results show important species differences in the effects of ethanol on brain neurosteroidogenesis. Given that ethanol does not alter cerebral cortical and hippocampal concentrations of allopregnanolone and progesterone in the two mouse strains examined, the differential sensitivity to some of the behavioral effects of ethanol cannot be directly correlated to hormonal changes in C57BL/6J and DBA/2J mice
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