2,171 research outputs found

    Some applications of quasi-velocities in optimal control

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    In this paper we study optimal control problems for nonholonomic systems defined on Lie algebroids by using quasi-velocities. We consider both kinematic, i.e. systems whose cost functional depends only on position and velocities, and dynamic optimal control problems, i.e. systems whose cost functional depends also on accelerations. The formulation of the problem directly at the level of Lie algebroids turns out to be the correct framework to explain in detail similar results appeared recently (Maruskin and Bloch, 2007). We also provide several examples to illustrate our construction.Comment: Revtex 4.1, 20 pages. To appear in Int. J. Geom. Meth. Modern Physic

    How does performing demanding activities influence prospective memory? A systematic review

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    This paper is the first systematic review on the role of ongoing task load in prospective remembering, which was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). Forty articles published between 1995 and 2020 were included. They evaluated prospective memory (PM) performance (i.e., the ability to remember to execute a delayed intention) in adult samples aged between 19 and 50 years old when the PM cue appeared under cognitively demanding conditions.The results revealed that people are more likely to fail to remember to perform a delayed intention at the appropriate circumstances or time in the future when their cognitive resources are taxed by demanding ongoing activities. We conclude the review by highlighting that the degree of working memory and executive resources seems to account for some of the discrepant findings and by proposing directions for future research.- This project was founded by the Portuguese Foundation for Science and Technology (FCT, Portugal) with the grant BD/123421/2016 awarded to Patricia Matos and with thegrant PD/BD/105964/2014 awarded to Diana R. Pereira. This study was conducted at the Psychology Research Centre (UID/PSI/01662/2019), University of Minho, and supported by the Portuguese Ministry of Science, Technology and Higher Education, through the State Budget (UID/PSI/01662/2019). Correspondence concerning this article should be addressed to Patricia Fernanda Ferreira Matos, School of Psychology, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal

    Transcriptome analysis of Taenia solium cysticerci using Open reading Frame ESTS (ORESTES)

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    <p>Abstract</p> <p>Background</p> <p>Human infection by the pork tapeworm <it>Taenia solium </it>affects more than 50 million people worldwide, particularly in underdeveloped and developing countries. Cysticercosis which arises from larval encystation can be life threatening and difficult to treat. Here, we investigate for the first time the transcriptome of the clinically relevant cysticerci larval form.</p> <p>Results</p> <p>Using Expressed Sequence Tags (ESTs) produced by the ORESTES method, a total of 1,520 high quality ESTs were generated from 20 ORESTES cDNA mini-libraries and its analysis revealed fragments of genes with promising applications including 51 ESTs matching antigens previously described in other species, as well as 113 sequences representing proteins with potential extracellular localization, with obvious applications for immune-diagnosis or vaccine development.</p> <p>Conclusion</p> <p>The set of sequences described here will contribute to deciphering the expression profile of this important parasite and will be informative for the genome assembly and annotation, as well as for studies of intra- and inter-specific sequence variability. Genes of interest for developing new diagnostic and therapeutic tools are described and discussed.</p

    Decapod crustacean larval communities in the Balearic Sea (western Mediterranean): Seasonal composition, horizontal and vertical distribution patterns

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    Decapod crustaceans are the main target species of deepwater bottomtrawl fisheries in the Balearic Sea but little is known about their larval stages. This work focuses on the species composition of the decapod larval community, describing the main spatio-temporal assemblages and assessing their vertical distribution. Mesozooplankton sampling was carried out using depth-stratified sampling devices at two stations located over the shelf break and themid slope, in the north-western and southern Mallorca in late autumn 2009 and summer 2010. Differences among decapod larvae communities, in terms of composition, adult's habitat such as pelagic or benthic, and distribution patternswere observed between seasons, areas and station. Results showed that for both seasonsmost species and developmental stages aggregatedwithin the upperwater column (above 75 mdepth) and showed higher biodiversity in summer compared to late autumn. Most abundant species were pelagic prawns (e.g., Sergestidae) occurring in both seasons and areas. The larval assemblages' distributions were different between seasonal hydrographic scenarios and during situations of stratified and non-stratified water column. The vertical distribution patterns of different larval developmental stages in respect to the adult's habitat were analyzed in relation to environmental variables. Fluorescence had the highest explanatory power. Four clearly different vertical patterns were identified: two corresponding to late autumn, which were common for all the main larval groups and other two in summer, one corresponding to larvae of coastal benthic and the second to pelagic species larvae.Versión del editor2,655

    Effect of 1-(phenyl)-N’-(4-methoxybenzylidene)-9H-pyrido[3,4-b]indole-3-carbohydrazide on in vitropoliovirus replication

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    The effect of the alkaloid, 1-(phenyl)-N’-(4-methoxybenzylidene)-9H-pyrido[3,4-b]indole-3-carbohydrazide (PMC)on poliovirus (PV) replication cycle in Vero cells was assayed by inhibition of the cytopathic effect (CPE) and inhibition of plaque forming units (PFU). Both methodologies suggested that the mode of action was avoidance of infection progression in the host cell. The compound was able to prevent CPE and PFU formation when the cells were pretreated with PMC for 24 h prior to PV infection. In addition, when the alkaloid was continuously maintained in the infected cultures, the spread of PV to adjacent cells was impaired. The pre-exposure and post-exposure prophylactic applications are possible situations in which an anti-PV drug might be used. Future studies are needed to elucidate the PMC mode of action and verify the feasibility of PMC use of in vivo. No antipicornavirus agent is currently approved for clinical use

    Cytotoxic and Antimicrobial Constituents from the Essential Oil of Lippia alba (Verbenaceae).

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    Backgroud:Lippia alba (Verbenaceae) is a plant widely used in folk medicine to treat various diseases. The present work deals with the chemical composition of the crude essential oil extracted from leaves of L. alba and evaluation of its antimicrobial and cytotoxic activities. Methods: Leaves of L. alba were extracted by hydrodistillation and analyzed by gas chromatography/mass spectrometry (GC/MS) as well as by nuclear magnetic resonance (NMR) spectroscopy. Cytotoxic and antimicrobial activities of crude essential oil were evaluated in vitro using MTT and broth microdilution assays, respectively. Results: Chemical analysis afforded the identification of 39 substances corresponding to 99.45% of the total oil composition. Concerning the main compounds, monoterpenes nerol/geraniol and citral correspond to approximately 50% of crude oil. The cytotoxic activity of obtained essential oil against several tumor cell lines showed IC50 values ranging from 45 to 64 µg/mL for B16F10Nex2 (murine melanoma) and A549 (human lung adenocarcinoma). In the antimicrobial assay, was observed that all tested yeast strains, except C. albicans, were sensitive to crude essential oil. MIC values were two to four-folds lower than those determined to bacterial strains. Conclusion: Analysis of chemical composition of essential oils from leaves of L. alba suggested a new chemotype nerol/geraniol and citral. Based in biological evidences, a possible application for studied oil as an antifungal in medicine, as well as in agriculture, is described

    Managing patients with dengue fever during an epidemic: the importance of a hydration tent and of a multidisciplinary approach

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    <p>Abstract</p> <p>Background</p> <p>Dengue fever is one of the most common tropical diseases worldwide. Early detection of the disease, followed by intravenous fluid therapy in patients with dengue hemorrhagic fever (DHF) or with warning signs of dengue has a major impact on the prognosis. The purpose of this study is to describe the care provided in a hydration tent, including early detection, treatment, and serial follow-up of patients with dengue fever.</p> <p>Findings</p> <p>The analysis included all patients treated in the hydration tent from April 8 to May 9, 2008. The tent was set up inside the premises of the 2<sup>nd </sup>Military Firemen Group, located in Meier, a neighborhood in Rio de Janeiro, Brazil. The case form data were stored in a computerized database for subsequent assessment. Patients were referred to the tent from primary care units and from secondary city and state hospitals. The routine procedure consisted of an initial screening including vital signs (temperature, blood pressure, heart rate, and respiratory rate), tourniquet test and blood sampling for complete blood count. Over a 31-day period, 3,393 case recordings were seen at the hydration tent. The mean was 109 patients per day. A total of 2,102 initial visits and 1,291 return visits were conducted. Of the patients who returned to the hydration tent for reevaluation, 850 returned once, 230 returned twice, 114 returned three times, and 97 returned four times or more. Overall, 93 (5.3%) patients with DHF seen at the tent were transferred to a tertiary hospital. There were no deaths among these patients.</p> <p>Discussion</p> <p>As the epidemics were already widespread and there were no technical conditions for routine serology, all cases of suspected dengue fever were treated as such. Implementing hydration tents decrease the number of dengue fever hospitalizations.</p

    Chemical Composition and In Vitro Cytotoxic and Antimicrobial Activities of the Essential Oil from Leaves of Zanthoxylum monogynum St. Hill (Rutaceae).

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    Background: The Zanthoxylum monogynum species belongs to the family Rutaceae and is found in Southeast, Midwest, and Northeast Brazil. For this genus several biological activities have been described. Methods: The essential oil (EO) was obtained from the leaves of Zanthoxylum monogynum by hydro-distillation and was analyzed by gas chromatograph and gas chromatograph/mass spectrometry (GC and GC/MS). Also the EO of Z. monogynum was evaluated for in vitro cytotoxic activity against six tumor cell lines and for antimicrobial activity, performing disk diffusion and MIC assays with yeast and bacterial strains. Results: The chemical analysis afforded the identification of 18 components (99.0% of the EO). The major components were found to be citronellol (43.0%) and farnesol (32.0%). The in vitro cytotoxic activity against tumor cell lines, resulted in IC50 values ranging from 11-65 µg/mL against all tested cell lines. Antimicrobial activity of the essential oil was also tested and oil was effective, especially against Cryptococcus sp. yeast. All the tested yeast strains showed at least 90% growth inhibition. Conclusions: the essential oil from leaves of Z. monogynum has a different qualitative and quantitative composition when compared to the composition previously described. Also this EO has significant cytotoxic activity and moderate activity against Cryptococcus sp. and Saccharomyces cereviseae yeasts

    Development and validation of a questionnaire to evaluate lifestyle-related behaviors in elementary school children

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    Background: The SI! Program promotes cardiovascular health through a multilevel school-based intervention on four lifestyle-related components: diet, physical activity, understanding the body and heart, and management of emotions. We report here the development and validation of the KAH (knowledge, attitudes and habits)-questionnaire adapted for elementary school children (6-7 years old) as a tool for the forthcoming evaluation of the SI! Program, where the KAH scoring will be the primary outcome. The efficacy of such an intervention will be based on the improvements in children's KAH towards a healthy lifestyle. Methods: The questionnaire validation process started with a pool of items proposed by the pedagogical team who developed the SI! Program for elementary school. The questionnaire was finalized by decreasing the number of items from 155 to 48 using expert panels and statistical tests on the responses from 384 children (ages 6-7). A team of specialized psychologists administered the questionnaire at schools providing standard directions for the final administration. The internal consistency was assessed using Cronbach's a coefficients. Reliability was measured through the split-half method, and problematic items were detected applying the item response theory. Analysis of variance and Tukey's test of additivity were used for multiple comparisons. Results: The final KAH-questionnaire for elementary school children should be administered to children individually by trained staff. The 48 items-questionnaire is divided evenly between the 4 components of the intervention, with an overall Cronbach's a = 0.791 (a = 0.526 for diet, a = 0.537 for physical activity, a = 0.523 for human body and heart, and a = 0.537 for management of emotions). Conclusions: The KAH-questionnaire is a reliable instrument to assess the efficacy of the SI! Program on instilling healthy lifestyle-related behaviors in elementary school children.This work is supported by the SHE Foundation (Foundation for Science, Health and Education) and the Daniel and Nina Carasso Foundation.S

    Single-blind, randomized, controlled trial of pelvic floor muscle training, electrical stimulation, vaginal cones, and no active treatment in the management of stress urinary incontinence

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    PURPOSE: To compare the effectiveness of pelvic floor exercises, electrical stimulation, vaginal cones, and no active treatment in women with urodynamic stress urinary incontinence. PATIENTS AND METHODS: One hundred eighteen subjects were randomly selected to recieve pelvic floor exercises (n=31), ES (n=30), vaginal cones (n=27), or no treatment (untreated control) (n=30). Women were evaluated before and after completion of six months of treatment by the pad test, quality of life questionnaire (I-QOL), urodynamic test, voiding diary, and subjective response. RESULTS: In the objective evaluation, we observed a statistically significant reduction in the pad test (p=0.003), in the number of stress urinary episodes (
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