1,768 research outputs found
Forecasting temporal dynamics of cutaneous leishmaniasis in Northeast Brazil.
IntroductionCutaneous leishmaniasis (CL) is a vector-borne disease of increasing importance in northeastern Brazil. It is known that sandflies, which spread the causative parasites, have weather-dependent population dynamics. Routinely-gathered weather data may be useful for anticipating disease risk and planning interventions.Methodology/principal findingsWe fit time series models using meteorological covariates to predict CL cases in a rural region of Bahía, Brazil from 1994 to 2004. We used the models to forecast CL cases for the period 2005 to 2008. Models accounting for meteorological predictors reduced mean squared error in one, two, and three month-ahead forecasts by up to 16% relative to forecasts from a null model accounting only for temporal autocorrelation.SignificanceThese outcomes suggest CL risk in northeastern Brazil might be partially dependent on weather. Responses to forecasted CL epidemics may include bolstering clinical capacity and disease surveillance in at-risk areas. Ecological mechanisms by which weather influences CL risk merit future research attention as public health intervention targets
Electrons in Dry DNA from Density Functional Calculations
The electronic structure of an infinite poly-guanine - poly-cytosine DNA
molecule in its dry A-helix structure is studied by means of density-functional
calculations. An extensive study of 30 nucleic base pairs is performed to
validate the method. The electronic energy bands of DNA close to the Fermi
level are then analyzed in order to clarify the electron transport properties
in this particularly simple DNA realization, probably the best suited candidate
for conduction. The energy scale found for the relevant band widths, as
compared with the energy fluctuations of vibrational or genetic-sequence
origin, makes highly implausible the coherent transport of electrons in this
system. The possibility of diffusive transport with sub-nanometer mean free
paths is, however, still open. Information for model Hamiltonians for
conduction is provided.Comment: 8 pages, 4 figure
Effects of anobiid damage on shear strength parallel to the grain in single step joints
ABSTRACT: Traditional carpentry joints can be found worldwide in many timber truss structures connecting rafter and tie beam. One failure mode of this connection result from shear in the tie beam beyond the notch either due to bad design or deterioration. In this article, the reduction in shear strength of Single Step Joints (SSJ) resulting from biological attack by anobiids was analysed. For this purpose, tests were carried out in non-degraded scots pine (Pinus sylvestris L.) specimens (reference) and compared to artificially degraded specimens with three different levels of degradation. The reduction of shear resistance was analysed in relation to the density of holes drilled during the degradation simulation, the loss of mass, and the reduction of the shear-resistant area. At lower degradation levels, no significant reduction in shear strength was observed. On the other hand, the linear regression shows a trend of resistance reduction with increasing degradation. Despite the relatively low coefficient of determination (r2 = 0.25), the parameter that best correlated with the residual strength was the reduction in the shear-resistant area.info:eu-repo/semantics/publishedVersio
Study on the glycerolysis reaction of high free fatty acid oils for use as biodiesel feedstock
Biodiesel is the main alternative to fossil diesel and it may be produced from different feedstocks such as semi-refined vegetable oils, waste frying oils or animal fats. However, these feedstocks usually contain significant amounts of free fatty acids (FFA) that make them inadequate for the direct base catalyzed transesterification reaction (where the FFA content should be lower than 4%). The present work describes a possible method for the pre-treatment of oils with a high content of FFA (20 to 50%) by esterification with glycerol. In order to reduce the FFA content, the reaction between these FFA and an esterification agent is carried out before the transesterification reaction. The reaction kinetics was studied in terms of its main factors such astemperature, % of glycerin excess, % of catalyst used, stirring velocity and type of catalyst used. The results showed that glycerolysis is a promising pretreatment to acidic oils or fats (> 20%) as they led to the production of an intermediary material with a low content of FFA that can be used directly in thetransesterification reaction for the production of biodiesel. (C) 2011 Elsevier B.V. All rights reserved
Mechanical characterization and fatigue assessment of wire and arc additively manufactured HSLA steel parts
Funding Information: The authors acknowledge Fundação para a Ciência e a Tecnologia (FCT - MCTES) for its financial support via project UIDB/00667/2020 (UNIDEMI) and project UIDB/50022/2020 (IDMEC under LAETA). The authors gratefully acknowledge A.J. Maltez - Sociedade Metalúrgica Lda for test specimen machining. Publisher Copyright: © 2022 Elsevier LtdWire and arc additive manufacturing (WAAM) has been attracting industrial attention due to its high productivity and flexibility. However, fatigue life data of WAAM HSLA steel is scarce. In this study, the mechanical properties and fatigue life of thin-walled HSLA steel parts fabricated by WAAM were assessed via non-destructive and destructive testing, providing a comprehensive analysis on this material's behaviour. The manufacturing conditions have a more pronounced effect on mechanical properties than the part's height, which seems not to influence the fatigue life of WAAM HSLA steels.publishersversionpublishe
Probable Person-to-Person Transmission of Legionnaires’ Disease
Correspondence to the Editor.Legionnaires’ disease is an often severe form of pneumonia that is typically acquired by susceptible persons (e.g., elderly persons and smokers) through inhalation of aerosols that contain legionella species.1-4 A cluster of cases of this disease occurred in Vila Franca de Xira, Portugal, in 2014
Long-term effects of psychotherapy on moderate depression: a comparative study of narrative therapy and cognitive-behavioral therapy
Background: In a previous clinical controlled trial (Lopes et al., 2014), narrative therapy (NT) showed
promising results in ameliorating depressive symptoms with comparable outcomes to cognitivebehavioral
therapy (CBT) when patients completed treatment. This paper aims to assess depressive
symptoms and interpersonal problems in this clinical sample at follow-up.
Methods: Using the Beck Depression Inventory-II and Outcome Questionnaire-45.2 Interpersonal
Relations Scale, naturalistic prospective follow-up assessment was conducted at 21 and 31 months after
the last treatment session.
Results: At follow-up, patients kept improving in terms of depressive symptoms and interpersonal
problems. The odds that a patient maintained recovery from depressive symptoms at follow-up were five
times higher than the odds that a patient maintained recovery from interpersonal problems. In the same
way, the odds of a patient never recovering from interpersonal problems were five times higher than the
odds of never recovering from depressive symptoms.
Limitations: The study did not control for the natural course of depression or treatment continuation.
Conclusions: For depressed patients with greater interpersonal disabilities, longer treatment plans and
alternative continuation treatments should be considered.The Portuguese Foundation for Science and Technology (FCT) supported this article through the Research Project "Ambivalence and Unsuccessful Psychotherapy" [PTDC/PSI-PCL/121525/2010], coordinated by M. Goncalves, and through a doctoral grant to R. Lopes [SFRH/BD/47343/2008].The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Hydrodynamic Drag during Gliding in Swimming
This study used a computational fluid dynamics methodology to analyze the effect of body position on the drag coefficient during submerged gliding in swimming. The k-epsilon turbulent model implemented in the commercial code Fluent and applied to the flow around a three-dimensional model of a male adult swimmer was used. Two common gliding positions were investigated: a ventral position with the arms extended at the front, and a ventral position with the arms placed along side the trunk. The simulations were applied to flow velocities of between 1.6 and 2.0 m x s(-1), which are typical of elite swimmers when gliding underwater at the start and in the turns. The gliding position with the arms extended at the front produced lower drag coefficients than with the arms placed along the trunk. We therefore recommend that swimmers adopt the arms in front position rather than the arms beside the trunk position during the underwater gliding.info:eu-repo/semantics/publishedVersio
Incidence of acute aortic dissections in patients with out of hospital cardiac arrest: a systematic review and meta-analysis of observational studies
© 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/Objectives: Acute Aortic dissection (AAD) may present as out-of-hospital cardiac arrest (OHCA). However, the incidence of this presentation is not well known. Our aim was to perform a systematic review and meta-analysis of all observational studies reporting on the incidence of AAD in patients with OHCA.
Methods: We searched MEDLINE, CENTRAL, PsycInfo, Web of Science Core Collection and OpenGrey databases from inception to March-2021, for observational studies reporting on the incidence of AAD in patients with OHCA. Data was pooled using a random-effects model of proportions. The primary outcome was the incidence of AAD in OHCA patients. Secondary outcomes were the incidence of type A aortic dissections (TAAD) and type B aortic dissections (TBAD) in OHCA patients, overall mortality following AAD-OHCA and risk of death in AAD-OHCA patients compared to risk of death of non-AAD-OHCA patients.
Results: Fourteen studies were included. The pooled calculated incidence of OHCA due to AAD was 4.39% (95 %CI: 2.55; 6.8). Incidence of OHCA due to TAAD was 7.18% (95 %CI: 5.61; 8.93) and incidence of OHCA due to TBAD was 0.47% (95 %CI: 0.18; 0.85). Overall mortality following OHCA due to AAD was 100% (95 %CI: 97.62; 100). The risk of death in AAD-OHCA patients compared with non-AAD-OHCA patients was 1.10 (95 %CI: 0.94; 1.30).
Conclusion: AAD as a cause of OHCA is more frequent than previously thought. Prognosis is dire, as it is invariably lethal. These findings should lead to a higher awareness of AAD when approaching a patient with OHCA and to future studies on this matter.info:eu-repo/semantics/publishedVersio
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