237 research outputs found

    Ecological niche model of Phlebotomus alexandri and P. papatasi (Diptera: Psychodidae) in the Middle East

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    <p>Abstract</p> <p>Background</p> <p>The purpose of this study is to create distribution models of two sand fly species, <it>Phlebotomus papatasi </it>(Scopoli) and <it>P. alexandri </it>(Sinton), across the Middle East. <it>Phlebotomus alexandri </it>is a vector of visceral leishmaniasis, while <it>P. papatasi </it>is a vector of cutaneous leishmaniasis and sand fly fever. Collection records were obtained from literature reports from 1950 through 2007 and unpublished field collection records. Environmental layers considered in the model were elevation, precipitation, land cover, and WorldClim bioclimatic variables. Models were evaluated using the threshold-independent area under the curve (AUC) receiver operating characteristic analysis and the threshold-dependent minimum training presence.</p> <p>Results</p> <p>For both species, land cover was the most influential environmental layer in model development. The bioclimatic and elevation variables all contributed to model development; however, none influenced the model as strongly as land cover.</p> <p>Conclusion</p> <p>While not perfect representations of the absolute distribution of <it>P. papatasi </it>and <it>P. alexandri</it>, these models indicate areas with a higher probability of presence of these species. This information could be used to help guide future research efforts into the ecology of these species and epidemiology of the pathogens that they transmit.</p

    A cone-beam X-ray computed tomography data collection designed for machine learning

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    Unlike previous works, this open data collection consists of X-ray cone-beam (CB) computed tomography (CT) datasets specifically designed for machine learning applications and high cone-angle artefact reduction. Forty-two walnuts were scanned with a laboratory X-ray set-up to provide not only data from a single object but from a class of objects with natural variability. For each walnut, CB projections on three different source orbits were acquired to provide CB data with different cone angles as well as being able to compute artefact-free, high-quality ground truth images from the combined data that can be used for supervised learning. We provide the complete image reconstruction pipeline: raw projection data, a description of the scanning geometry, pre-processing and reconstruction scripts using open software, and the reconstructed volumes. Due to this, the dataset can not only be used for high cone-angle artefact reduction but also for algorithm development and evaluation for other tasks, such as image reconstruction from limited or sparse-angle (low-dose) scanning, super resolution, or segmentation

    A cone-beam X-ray computed tomography data collection designed for machine learning

    Get PDF
    Unlike previous works, this open data collection consists of X-ray cone-beam (CB) computed tomography (CT) datasets specifically designed for machine learning applications and high cone-angle artefact reduction. Forty-two walnuts were scanned with a laboratory X-ray set-up to provide not only data from a single object but from a class of objects with natural variability. For each walnut, CB projections on three different source orbits were acquired to provide CB data with different cone angles as well as being able to compute artefact-free, high-quality ground truth images from the combined data that can be used for supervised learning. We provide the complete image reconstruction pipeline: raw projection data, a description of the scanning geometry, pre-processing and reconstruction scripts using open software, and the reconstructed volumes. Due to this, the dataset can not only be used for high cone-angle artefact reduction but also for algorithm development and evaluation for other tasks, such as image reconstruction from limited or sparse-angle (low-dose) scanning, super resolution, or segmentation

    Serum free light chain quantitative assays: Dilemma of a biomarker

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    Background: Serum free light chains detection assays are consistently meeting greater interest for the diagnosis and monitoring of monoclonal gammopathies and plasma cell dyscrasias. Nowadays, there are neither standardized methods nor reference material for the determination of free light chains; for this reason, it is important to compare two different assays used in clinical laboratory. Methods: We evaluated 300 serum samples from patients with B-cell disorders and compared the analytical performances of both assay. Each test was assayed on both testing platforms (Siemens Dade Behring BN II Nephelometer and SPAPLUS by The Binding Site). κ/λ ratios were determined and compared. Results were analyzed by Passing-Bablok and Bland-Altman plots to evaluate comparability of the two techniques and to determine bias. Results: The reproducibility of both assays is acceptable, reaching minimum and desirable analytical goals derived from biological variability. However, values are not interchangeable between systems. This study shows that the two systems do not allow results to be transferred from one method to the other even if they display good agreement. Conclusion: Our study highlights the importance of elaborating an international standard for free light chains quantification in order to offer homogeneous results as well as guarantee harmonization of values among laboratories. Moreover, the assays should be validated in specific patient groups to determine that they are clinically fit for purpose

    The AFHSC-Division of GEIS Operations Predictive Surveillance Program: a multidisciplinary approach for the early detection and response to disease outbreaks

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    The Armed Forces Health Surveillance Center, Division of Global Emerging Infections Surveillance and Response System Operations (AFHSC-GEIS) initiated a coordinated, multidisciplinary program to link data sets and information derived from eco-climatic remote sensing activities, ecologic niche modeling, arthropod vector, animal disease-host/reservoir, and human disease surveillance for febrile illnesses, into a predictive surveillance program that generates advisories and alerts on emerging infectious disease outbreaks. The program’s ultimate goal is pro-active public health practice through pre-event preparedness, prevention and control, and response decision-making and prioritization. This multidisciplinary program is rooted in over 10 years experience in predictive surveillance for Rift Valley fever outbreaks in Eastern Africa. The AFHSC-GEIS Rift Valley fever project is based on the identification and use of disease-emergence critical detection points as reliable signals for increased outbreak risk. The AFHSC-GEIS predictive surveillance program has formalized the Rift Valley fever project into a structured template for extending predictive surveillance capability to other Department of Defense (DoD)-priority vector- and water-borne, and zoonotic diseases and geographic areas. These include leishmaniasis, malaria, and Crimea-Congo and other viral hemorrhagic fevers in Central Asia and Africa, dengue fever in Asia and the Americas, Japanese encephalitis (JE) and chikungunya fever in Asia, and rickettsial and other tick-borne infections in the U.S., Africa and Asia

    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

    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

    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
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