4,250 research outputs found

    A novel orbiter mission concept for venus with the envision proposal

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    In space exploration, planetary orbiter missions are essential to gain insight into planets as a whole, and to help uncover unanswered scientific questions. In particular, the planets closest to the Earth have been a privileged target of the world’s leading space agencies. EnVision is a mission proposal with the objective of studying Earth’s closest neighbor. Designed for Venus and competing for ESA’s next launch opportunity, the proposal already went through the selective technical review for the M4 launch opportunity, and was submitted to the M5 call, incorporating feedback from ESA. The main goal is to study geological and atmospheric processes, namely surface processes, interior dynamics and atmosphere, to determine the reasons behind Venus and Earth’s radically different evolution despite the planets’ similarities. To achieve these goals, the operational orbit selection is a fundamental element of the mission design process. The design of an orbit around Venus faces specific challenges, such as the impossibility of choosing Sun-synchronous orbits. In this paper, an innovative genetic algorithm optimization was applied to select the optimal orbit based on the parameters with more influence in the mission planning, in particular the mission duration and the coverage of sites of interest on the Venusian surface. After summarizing the EnVision proposal’s mission concept for Venus, the optimization and innovation of the operational orbit design will be analyzed in terms of its benefits to the mission

    Primary gastric plasmacytoma: a rare entity

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    Extramedullary plasmacytomas (EP) are tumours composed by a monoclonal population of plasma cells that arise in extraosseus tissues, comprising <5% of all plasma cell neoplasms. Usually, EP arise in the head and neck region, and the stomach is the second most common location-gastric plasmacytoma (GP). Clinical and radiological manifestations are unspecific and may mimic other tumours like gastric adenocarcinomas, gastric stromal tumours and lymphomas, mainly marginal cell lymphoma (MALT lymphoma) and usually definitive diagnosis is provided by pathological evaluation. We present a case of primary GP, discovered incidentally as a polypoid lesion. Tumour was composed by sheets of mature and immature plasmocytes positive for CD138 on immunohistochemistry, without Helicobacter pylori identification. The patient is alive 6 years later and without tumour relapse.info:eu-repo/semantics/publishedVersio

    Anatomical and histochemical analysis of vegetative organs of Vernonia ferruginea Less. (Asteraceae)

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    Vernonia ferruginea Less. is a perennial shrub species, present in several regions of Brazil, especially in the savanna. It is popularly used as a phytotherapic. This fact justifies the need to anatomically characterize the plant for its accurate identification and to conduct histochemical studies with the aim of identifying the chemical nature of its cellular constituents. The species-specific data will contribute significantly to pharmaceutical quality control and also provide information about the sites of specific chemical compounds. Samples of V. ferruginea vegetative organs were collected and submitted to the usual plant anatomy and histochemical techniques. The leaves are anfihipoestomática with anomocytic stomata; have tector and glandular trichomes that store essential oils. The stem has collateral-type vascular bundles arranged in a eustele structure; it also has glandular and tector trichomes. The root has brachysclereids, endoderm with various chemical compounds and vascular bundles having axial elements and rays. Few differences were found in the structure of vegetative organs in relation to other species of the genus, confirming the importance of the details shown.Key words: Plant anatomy, assapeixe-branco, essential oils

    Biodegradability of diesel and biodiesel blends

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    The biodegradability of pure diesel and biodiesel and blends with different proportions of biodiesel (2%(commercial); 5% and 20%) was evaluated employing the respirometric method and the redox indicator2,6-dichlorophenol indophenol (DCPIP) test. In the former, experiments simulating the contamination of natural environments (soil from a petrol station or water from a river) were carried out in Bartha biometer flasks (250 ml), and used to measure the microbial CO2 production. With the DCPIP test, the capability of three inocula to biodegrade the blends was tested. Results show that although biodiesel is more easily and faster biodegraded than diesel oil, among the blends evaluated (2%, 5% and 20%), only the blend with higher concentration of biodiesel presented biodegradability significantly different from diesel and it was not verified an improvement on the biodegradation of the diesel by means of  cometabolism

    Schistosoma mansoni infection and the associated antibody immune response amongst residents of Kigungu Entebbe, Uganda

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    Background: There are many foci endemic for Schistosoma (S.) mansoni in Uganda. The immune responses to infection with the parasites in these areas have been found to vary with host sex, age and infection intensity.Objective: To determine the profile of antibody isotypes responses against S. mansoni crude soluble egg antigens (SEA) and soluble adult worm protein (SWAP) antigens that determine the host resistance or susceptibility to reinfection.Design: Cross Sectional, cohort study.Setting: Kigugu fishing village in Entebbe, Uganda.Subjects: Nine hundred and forty five (945) Kigungu residents reported for pre-treatment screening and enrolment and 626 cohorts report for post-treatment screening and enrolment 18 months later.Results: Pearson’s Chi-sq2 showed that increase in titres of anti (SWAP IgE, SEA IgE, and SEA IgG2) was not significant, but increase in anti SEA IgG3 was significant. Decrease in titres of anti (SWAP IgG1, SEA IgG1, and SEA IgG4) was not significant but decrease of anti (SWAP IgG2, SWAP IgG3 and SWAP IgG4) was significant. Positive correlation existed between age and anti SWAP IgE in before and after treatment sera. On the contrary, age was positively correlated with anti SWAP IgG4 in pre-treatment sera but was negatively correlated with anti SWAP IgG4 in the post-treatment sera. In addition there were positive correlation between higher egg counts and the immunoglobulin levels of anti SWAP IgG4 and anti SEA IgG4 but negative correlations were observed between anti SWAP IgE and anti SEA IgE. Conversely low egg counts were associated with high levels of anti SWAP IgE. Furthermore, IgG1-4, IgE antibody to SEA and SWAP antigens did not differ significantly according to sex.Conclusion: We concluded that praziquantel treatment of S. mansoni infected persons alter the immune responses that are influenced by age and intensity. A phenomenon that is useful in the effort to produce vaccine against schistosome

    Evidence of Long Term Benefit of Praziquantel Treatment Against Schistosoma mansoni in Kigungu Fishing Village of Entebbe, Uganda

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    Praziquantel (PZQ) is efficacious against all species of schistosome: Schistosoma mansoni; Schistosoma haematobium; Schistosoma japonicum and other parasites like the Taenia species. This cross-sectional cohorts study was carried out in Kigungu fishing village along Lake Victoria shore in Entebbe Uganda. Our analysis was based on examining microscopically three slides from a single stool specimen from each of base line cohorts 945.These included children and adults, participants from both sexes in Kigungu fishing village in Entebbe Uganda. Nine hundred and one (901) of the cohorts were re-examined after six months and 625 of the same cohorts who were examined at the baseline and after six months were re-examined 18 months later. The slides were prepared using modified Kato/Katz (Odongo-Aginya) method. The infection proportion with Schistosoma mansoni at baseline was 448 (47.5%) but this was reduced to 244 (25.8%) 18 months after treatment with a single oral dose of praziquantel at 40mg/kg. However 495 (52.5%) were negative at the baseline study. The cure proportion after six was significant {(P=0.00), (OR4.63) CI at 95% (3.53-6.06)}. Similarly the cure proportion after 18 months was significant {(P=0.00), (OR2.2) CI at 95% (1.87-3.34)}. The force of re-infection after six months was significant {(P=0.0001), (OR 0.47) CI at 95% (0.31-0.71)}. Nevertheless the force of re-infection was not significant after 18 months {(P=0.766), (OR 0.95) CI at 95% (0.68-1.34)} eggs excretion did not reach the level of the pre-treatment intensity. The egg reduction was 69.3%. This was associated with age and pre-treatment intensity &lt; 400 eggs per gram (epg) of faeces and age groups &ge; 30 years. The egg reduction also resulted in marked decrease in clinical symptoms in the participants. Our study suggests evidence of long-term benefit of praziquantel in Kigungu and that the re-infection occurred more commonly in younger age group than in the older patients.Key words: Praziquantel; Schistosoma mansoni; Kigungu; Entebbe; Uganda

    Decoding negative affect personality trait from patterns of brain activation to threat stimuli

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    INTRODUCTION: Pattern recognition analysis (PRA) applied to functional magnetic resonance imaging (fMRI) has been used to decode cognitive processes and identify possible biomarkers for mental illness. In the present study, we investigated whether the positive affect (PA) or negative affect (NA) personality traits could be decoded from patterns of brain activation in response to a human threat using a healthy sample. METHODS: fMRI data from 34 volunteers (15 women) were acquired during a simple motor task while the volunteers viewed a set of threat stimuli that were directed either toward them or away from them and matched neutral pictures. For each participant, contrast images from a General Linear Model (GLM) between the threat versus neutral stimuli defined the spatial patterns used as input to the regression model. We applied a multiple kernel learning (MKL) regression combining information from different brain regions hierarchically in a whole brain model to decode the NA and PA from patterns of brain activation in response to threat stimuli. RESULTS: The MKL model was able to decode NA but not PA from the contrast images between threat stimuli directed away versus neutral with a significance above chance. The correlation and the mean squared error (MSE) between predicted and actual NA were 0.52 (p-value=0.01) and 24.43 (p-value=0.01), respectively. The MKL pattern regression model identified a network with 37 regions that contributed to the predictions. Some of the regions were related to perception (e.g., occipital and temporal regions) while others were related to emotional evaluation (e.g., caudate and prefrontal regions). CONCLUSION: These results suggest that there was an interaction between the individuals' NA and the brain response to the threat stimuli directed away, which enabled the MKL model to decode NA from the brain patterns. To our knowledge, this is the first evidence that PRA can be used to decode a personality trait from patterns of brain activation during emotional contexts
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