2,959 research outputs found

    Plasma free amino acid profiles of Boer goat bucks as influenced by two feeding regimens

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    The aim of the study was to monitor the physiological changes in plasma free amino acid profiles in Boer goats under nutritional restriction. Fifteen Boer goat bucks were allocated to two experimental groups: CG (control), fed Themeda trianda hay, supplemented with maize, molasses and urea ad libitum; and RG (restricted feeding) fed the same hay (80 and 86% of the daily NRC energy and protein requirements, respectively) for 29 days. Animals were weighed and blood collected weekly for determination of plasma free amino acid profiles and the results compared between experimental groups. At the end of the experimental period the CG animals had higher concentrations of alanine, tyrosine and citrulline amino acids. The RG group had higher concentrations of valine, isoleucine, leucine, threonine, methionine, lysine, taurine, ornithine, hydroxyproline and tri-methyl-histidine, while glycine, serine, aspartic acid, glutamic acid, arginine, histidine and proline levels were similar in both groups. From the results it can be concluded that plasma amino acid profiles in the Boer goat were significantly affected by nutritional restriction. The degradation of short carbon chain amino acids is preferred to long carbon chain amino acids for gluconeogenesis in the physiological mechanisms of response to nutritional restriction in Boer goats. Keywords: Boer goat; nutrition; restricted feeding; amino acids South African Journal of Animal Science Vol. 36 (5) 2006: pp.14-1

    Water-equivalence of phantom materials in proton and carbon-ion dosimetry

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    The growing interest in light-ion therapy in recent decades has led to a need for accurate dosimetry. At present, a calibration service based on a primary-standard calorimeter for the direct determination of absorbed dose to water for light-ion beams does not exist. Furthermore, the water-equivalent plastics currently used for light-ion beam dosimetry were designed to be used with high-energy photon and electron beams thus energy- and depth-dependent correction factors need to be applied to measurements of dose to water in plastic phantoms. The first portable graphite calorimeter for light-ion beams was built at the National Physical Laboratory (NPL), UK. In this work, fluence correction factors required to convert absorbed dose to graphite, measured by graphite calorimetry, to absorbed dose to water were determined experimentally and compared with Monte Carlo simulations in proton and carbon-ion beams. Fluence corrections in high-energy light-ion beams could amount to as much as 4% and therefore need to be considered. Novel water-equivalent plastics were specifically designed for light-ion beams and three test compositions were produced and experimentally characterised in proton and carbon-ion beams. Commercially available plastics were also simulated for comparison with the plastics tested experimentally. Experimental data showed that each of the novel water-equivalent plastics showed measurements of dose similar to water to within 1\% across all depths. Monte Carlo simulations showed that one of the novel plastics had superior water-equivalence to commercially available plastics in carbon-ion beams, with a maximum fluence correction of 0.5%. The accuracy of particle transport in the FLUKA Monte Carlo code for proton beams was assessed by performing a Fano cavity test. FLUKA was found to pass this test to within 0.1%. Ion-chamber perturbation factors were also computed for the PTW 34070 Bragg peak chamber typically used in clinical proton beams

    Singularities of equidistants and global centre symmetry sets of Lagrangian submanifolds

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    We define the Global Centre Symmetry set (GCS) of a smooth closed m-dimensional submanifold M of R^n, n2mn \leq 2m, which is an affinely invariant generalization of the centre of a k-sphere in R^{k+1}. The GCS includes both the centre symmetry set defined by Janeczko and the Wigner caustic defined by Berry. We develop a new method for studying generic singularities of the GCS which is suited to the case when M is lagrangian in R^{2m} with canonical symplectic form. The definition of the GCS, which slightly generalizes one by Giblin and Zakalyukin, is based on the notion of affine equidistants, so, we first study singularities of affine equidistants of Lagrangian submanifolds, classifying all the stable ones. Then, we classify the affine-Lagrangian stable singularities of the GCS of Lagrangian submanifolds and show that, already for smooth closed convex curves in R^2, many singularities of the GCS which are affine stable are not affine-Lagrangian stable.Comment: 26 pages, 2 figure

    CANFOR Portuguese version: validation study

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    This study is embedded in the larger project "Needs Assessment of the Mentally Disordered Prisoners" funded by Fundacao para a Ciencia e Tecnologia (PIC/IC/83257/2007). We acknowledge the General-Director for Prison Services for his authorization, the Prisons' Directors for their support, the medical and non-medical staff who collaborated in this study and detainees for their participation. Special thanks to Dr Ana Cabral for her support inside the prisons and Dr Jorge Pereira for his assistance in manuscript preparation. In memory of our late friend Dr Jose Morais, who collaborated on and supported this study from the beginning.BACKGROUND The increase in prisoner population is a troublesome reality in several regions of the world. Along with this growth there is increasing evidence that prisoners have a higher proportion of mental illnesses and suicide than the general population. In order to implement strategies that address criminal recidivism and the health and social status of prisoners, particularly in mental disordered offenders, it is necessary to assess their care needs in a comprehensive, but individual perspective. This assessment must include potential harmful areas like comorbid personality disorder, substance misuse and offending behaviours. The Camberwell Assessment of Need - Forensic Version (CANFOR) has proved to be a reliable tool designed to accomplish such aims. The present study aimed to validate the CANFOR Portuguese version. METHODS The translation, adaptation to the Portuguese context, back-translation and revision followed the usual procedures. The sample comprised all detainees receiving psychiatric care in four forensic facilities, over a one year period. A total of 143 subjects, and respective case manager, were selected. The forensic facilities were chosen by convenience: one prison hospital psychiatric ward (n=68; 47.6%), one male (n=24; 16.8%) and one female (n=22; 15.4%) psychiatric clinic and one civil security ward (n=29; 20.3%), all located nearby Lisbon. Basic descriptive statistics and Kappa weighted coefficients were calculated for the inter-rater and the test-retest reliability studies. The convergent validity was evaluated using the Global Assessment of Functioning and the Brief Psychiatric Rating Scale scores. RESULTS The majority of the participants were male and single, with short school attendance, and accused of a crime involving violence against persons. The most frequent diagnosis was major depression (56.1%) and almost half presented positive suicide risk. The reliability study showed average Kappa weighted coefficients of 0.884 and 0.445 for inter-rater and test-retest agreement, respectively. The convergent validity study presented highly significant correlations between unmet needs scores, GAF and BPRS scores. CONCLUSIONS The CANFOR Portuguese version revealed similar psychometric properties to the original English version. Moreover, the results of the reliability and validity studies indicate that the tool is appropriate for individual care needs assessment and as a guide for the mental health and social interventions in forensic psychiatric services.publishersversionpublishe

    Direct determination of molybdenum in polyvitaminic tablets by voltammetry in non-aqueous media.

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    Adsorptive stripping voltammetry carried out in a homogeneous ternary solvent composed of N,N-dimethylformamide, water and ethanol, with alpha-benzoinoxime (alpha BO) as the complexing agent for Mo(VI) and a 0.5 mol L-1 acetic acid - sodium acetate buffer as supporting electrolyte was successfully used for the determination of molybdenum in polyvitamin-polymineral tablets. Tablet samples were analyzed and the results were compared with those obtained both by graphite furnace atomic absorption and by recovery tests, with good correlations. indicating that this may be considered as an alternative procedure for routine determination of Mo(VI) in pharmaceutical samples.29115315

    Cohabitation in Brazil : historical legacy and recent evolution

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    The availability of the micro data in the IPUMS samples for several censuses spanning a period of 40 years permits a detailed study of differentials and trends in cohabitation in Brazil than has hitherto been the case. The gist of the story is that the historical race/class and religious differentials and the historical spatial contrasts have largely been maintained, but are now operating at much higher levels than in the 1970s. During the last 40 years cohabitation has dramatically increased in all strata of the Brazilian population, and it has spread geographically to all areas in tandem with further expansions in the regions that had historically higher levels to start with. Moreover, the probability of cohabiting depends not only on individual-level characteristics but also on additional contextual effects operating at the level of meso-regions. The rise of cohabitation in Brazil fits the model of the "Second demographic transition", but it is grafted onto a historical pattern which is still manifesting itself in a number of ways

    As biografias educativas como fonte de pesquisa e estudo no campo da forma??o docente : notas iniciais para uma discuss?o te?rico/metodol?gica.

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    Este artigo busca analisar uma tend?ncia te?rica, mas sobretudo metodol?gica, que vem se constituindo como um campo rico de estudos e pesquisas na ?rea da forma??o docente: as narrativas biogr?ficas, os estudos de mem?rias de forma??o elaboradas pelos professores em exerc?cio ou em forma??o. Recorrem na escrita de memoriais que podem ser percebidos como uma ferramenta de reflex?o biogr?fica a respeito da forma??o inicial e continuada, momento em que s?o expostos os desafios, as dificuldades e as crises da vida profissional, a partir de lembran?as sobre o passado escolar e das reflex?es sobre o presente e o devir. Sem pretender fazer um balan?o da bibliografia j? existente e muito menos esgotar o tema, pretende-se com esta discuss?o inicial situar o debate sobre os estudos biogr?ficos como fonte te?rico-metodol?gica e suas contribui??es na forma??o docente

    A novel multivariate STeady-state index during general ANesthesia (STAN)

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    The assessment of the adequacy of general anesthesia for surgery, namely the nociception/anti-nociception balance, has received wide attention from the scientific community. Monitoring systems based on the frontal EEG/EMG, or autonomic state reactions (e.g. heart rate and blood pressure) have been developed aiming to objectively assess this balance. In this study a new multivariate indicator of patients' steady-state during anesthesia (STAN) is proposed, based on wavelet analysis of signals linked to noxious activation. A clinical protocol was designed to analyze precise noxious stimuli (laryngoscopy/intubation, tetanic, and incision), under three different analgesic doses; patients were randomized to receive either remifentanil 2.0, 3.0 or 4.0 ng/ml. ECG, PPG, BP, BIS, EMG and [Formula: see text] were continuously recorded. ECG, PPG and BP were processed to extract beat-to-beat information, and [Formula: see text] curve used to estimate the respiration rate. A combined steady-state index based on wavelet analysis of these variables, was applied and compared between the three study groups and stimuli (Wilcoxon signed ranks, Kruskal-Wallis and Mann-Whitney tests). Following institutional approval and signing the informed consent thirty four patients were enrolled in this study (3 excluded due to signal loss during data collection). The BIS index of the EEG, frontal EMG, heart rate, BP, and PPG wave amplitude changed in response to different noxious stimuli. Laryngoscopy/intubation was the stimulus with the more pronounced response [Formula: see text]. These variables were used in the construction of the combined index STAN; STAN responded adequately to noxious stimuli, with a more pronounced response to laryngoscopy/intubation (18.5-43.1 %, [Formula: see text]), and the attenuation provided by the analgesic, detecting steady-state periods in the different physiological signals analyzed (approximately 50 % of the total study time). A new multivariate approach for the assessment of the patient steady-state during general anesthesia was developed. The proposed wavelet based multivariate index responds adequately to different noxious stimuli, and attenuation provided by the analgesic in a dose-dependent manner for each stimulus analyzed in this study.The first author was supported by a scholarship from the Portuguese Foundation for Science and Technology (FCT SFRH/BD/35879/2007). The authors would also like to acknowledge the support of UISPA—System Integration and Process Automation Unit—Part of the LAETA (Associated Laboratory of Energy, Transports and Aeronautics) a I&D Unit of the Foundation for Science and Technology (FCT), Portugal. FCT support under project PEst-OE/EME/LA0022/2013.info:eu-repo/semantics/publishedVersio

    Resistance to tyrosine kinase inhibitors in chronic myeloid leukemia—from molecular mechanisms to clinical relevance

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    Resistance to targeted therapies is a complex and multifactorial process that culminates in the selection of a cancer clone with the ability to evade treatment. Chronic myeloid leukemia (CML) was the first malignancy recognized to be associated with a genetic alteration, the t(9;22)(q34;q11). This translocation originates the BCR-ABL1 fusion gene, encoding the cytoplasmic chimeric BCRABL1 protein that displays an abnormally high tyrosine kinase activity. Although the vast majority of patients with CML respond to Imatinib, a tyrosine kinase inhibitor (TKI), resistance might occur either de novo or during treatment. In CML, the TKI resistance mechanisms are usually subdivided into BCR-ABL1-dependent and independent mechanisms. Furthermore, patients’ compliance/adherence to therapy is critical to CML management. Techniques with enhanced sensitivity like NGS and dPCR, the use of artificial intelligence (AI) techniques, and the development of mathematical modeling and computational prediction methods could reveal the underlying mechanisms of drug resistance and facilitate the design of more effective treatment strategies for improving drug efficacy in CML patients. Here we review the molecular mechanisms and other factors involved in resistance to TKIs in CML and the new methodologies to access these mechanisms, and the therapeutic approaches to circumvent TKI resistance
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