142 research outputs found

    Current and Future Niche of North and Central American Sand Flies (Diptera: Psychodidae) in Climate Change Scenarios

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    Ecological niche models are useful tools to infer potential spatial and temporal distributions in vector species and to measure epidemiological risk for infectious diseases such as the Leishmaniases. The ecological niche of 28 North and Central American sand fly species, including those with epidemiological relevance, can be used to analyze the vector’s ecology and its association with transmission risk, and plan integrated regional vector surveillance and control programs. In this study, we model the environmental requirements of the principal North and Central American phlebotomine species and analyze three niche characteristics over future climate change scenarios: i) potential change in niche breadth, ii) direction and magnitude of niche centroid shifts, iii) shifts in elevation range. Niche identity between confirmed or incriminated Leishmania vector sand flies in Mexico, and human cases were analyzed. Niche models were constructed using sand fly occurrence datapoints from Canada, USA, Mexico, Guatemala and Belize. Nine non-correlated bioclimatic and four topographic data layers were used as niche components using GARP in OpenModeller. Both B2 and A2 climate change scenarios were used with two general circulation models for each scenario (CSIRO and HadCM3), for 2020, 2050 and 2080. There was an increase in niche breadth to 2080 in both scenarios for all species with the exception of Lutzomyia vexator. The principal direction of niche centroid displacement was to the northwest (64%), while the elevation range decreased greatest for tropical, and least for broad-range species. Lutzomyia cruciata is the only epidemiologically important species with high niche identity with that of Leishmania spp. in Mexico. Continued landscape modification in future climate change will provide an increased opportunity for the geographic expansion of NCA sand flys’ ENM and human exposure to vectors of Leishmaniases

    Assessment of sense of taste in Italian Centenarians

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    The Italian multicentric study on centenarians (IMSC) was aimed at assessing the level of preservation of the sense of taste, and at estimating to what extent the recognition of various gustative stimuli can give satisfaction and information regarding the surrounding environment for the centenarians. Taste sensitivity has been qualitatively established in a group of 126 Italian centenarians (mean age 101.9 \ub1 1.4 years) and compared to that of a group of 100 elderly subjects (mean age 70.5 \ub1 5.0 years). All the individuals included in the study groups had a mini mental state examination (MMSE) score larger than 19. The results revealed that taste sensitivity is significantly reduced in the centenarians; as a matter of fact, the elderly control subjects are able to perceive taste stimuli in 84.25 \ub1 3.40% of the testing, while the centenarians were successful only in 74.23 \ub1 6.19% of the experiments (P < 0.001). Furthermore, elderly subjects can correctly recognize taste stimuli in 70% of the testings, while correct recognition amounted only to 49.25% in cases of centenarians assessed. In spite of these differences between the elderly and centenarians, the latter are still able to perceive and recognize taste stimuli adequately, and as a consequence, are able to obtain information on tastes and receive a sufficient sensory stimulation through the tasting pathway

    Laboratory parameters of italian centenarians

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    A consortium of 20 university departments of geriatrics and gerontology conducted the Italian Multicentric Study on Centenarians (IMSC), in order to assess the socio-economic, clinical and biological conditions of the Italian centenarians. The investigation involved 382 subjects randomly selected from a total of 1162 centenarians (234 men and 928 women), recorded by a census carried out until 31 December, 1993. Their case history, clinical and socio-economic data were recorded on a computerized clinical case sheet. Blood samples for the purpose of the present investigations were drawn from 257 of them. A great proportion (79%) of these latter subjects displayed satisfactory general conditions in their laboratory parameters, 18.3% of them had fairly good clinical conditions even with slightly modified laboratory parameters. Only a low percentage (2.8%) had poor general conditions with a marked anemia, hyperazotemia and uric acid levels. Long duration diabetes was practically absent, and only 5.5% of our centenarians displayed hyperglycemia with a mean duration time of 9.3 years. The prevalence of subjects with hypercholesterolemia was 31.1%. Only 4.3% of centenarians was affected by mixed form of dyslipidemia (hypertriglyceridemia associated with hypercholesterolemia), confirming that elevated blood lipid contents jeopardize really long survival

    The pathophysiology of restricted repetitive behavior

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    Restricted, repetitive behaviors (RRBs) are heterogeneous ranging from stereotypic body movements to rituals to restricted interests. RRBs are most strongly associated with autism but occur in a number of other clinical disorders as well as in typical development. There does not seem to be a category of RRB that is unique or specific to autism and RRB does not seem to be robustly correlated with specific cognitive, sensory or motor abnormalities in autism. Despite its clinical significance, little is known about the pathophysiology of RRB. Both clinical and animal models studies link repetitive behaviors to genetic mutations and a number of specific genetic syndromes have RRBs as part of the clinical phenotype. Genetic risk factors may interact with experiential factors resulting in the extremes in repetitive behavior phenotypic expression that characterize autism. Few studies of individuals with autism have correlated MRI findings and RRBs and no attempt has been made to associate RRB and post-mortem tissue findings. Available clinical and animal models data indicate functional and structural alterations in cortical-basal ganglia circuitry in the expression of RRB, however. Our own studies point to reduced activity of the indirect basal ganglia pathway being associated with high levels of repetitive behavior in an animal model. These findings, if generalizable, suggest specific therapeutic targets. These, and perhaps other, perturbations to cortical basal ganglia circuitry are mediated by specific molecular mechanisms (e.g., altered gene expression) that result in long-term, experience-dependent neuroadaptations that initiate and maintain repetitive behavior. A great deal more research is needed to uncover such mechanisms. Work in areas such as substance abuse, OCD, Tourette syndrome, Parkinson’s disease, and dementias promise to provide findings critical for identifying neurobiological mechanisms relevant to RRB in autism. Moreover, basic research in areas such as birdsong, habit formation, and procedural learning may provide additional, much needed clues. Understanding the pathophysioloy of repetitive behavior will be critical to identifying novel therapeutic targets and strategies for individuals with autism

    CONSERVATION BENEFITS OF THE USDA'S 1983 PAYMENT-IN-KIND AND ACREAGE REDUCTION PROGRAMS

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    The U.S. Department of Agriculture's 1983 Payment-in-Kind and Acreage Reduction Programs reduced soil erosion on the land withdrawn from production by an average of 1.8 tons per acre per year over the 80 million acres diverted. The erosion reduction could have been significantly greater had the program targeted highly erodible land and had the diverted acres been adequately protected from erosion. Water withdrawal was reduced by 1.6 acre-feet per acre because of diverted lands that would have been irrigated. About 35 percent of the diverted acres provided suitable cover for wildlife. The analysis was based on data from a sample of over 4,900 farms in 278 counties

    Phosphatidylinositide dependent kinase deficiency increases anxiety and decreases GABA and serotonin abundance in the amygdala

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    Pathological anxiety is paralleled by deficits in serotonergic and GABAergic neurotransmission in the amygdala. Conversely, anxiety disorders and depression may be reversed by brain-derived neurotrophic factor (BDNF). BDNF signaling involves Phosphatidylinositol 3-Kinase/ 3-phosphoinositide-dependent protein kinase 1 (PI3K/PDK1). We thus hypothesized that impaired function of PDK1 might be associated with increased anxiety and concomitant neurotransmitter changes. Here we used the hypomorphic PDK1hm mouse to investigate anxiety behavior in different settings: PDK1hm mice differed from Wt littermates PDK1WT in several behavioral measures related to anxiety and exploration, namely in the open field, dark-light box, O-maze and startle response. Further we analyzed the brain substrate underlying this phenotype and found significantly decreased GABA, taurine and serotonin concentrations in the amygdala and olfactory bulb of PDK1hm mice, while BDNF and nerve growth factor (NGF) concentrations were not significantly different between PDK1hm and PDK1WT mice. These results suggest that impaired PI3K signaling in the PDK1hm mouse reduces concentrations of GABA and serotonin in anxiety related brain regions and can serve as a molecular substrate for behavior indicative for anxious and depressive-like mood states
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