Propiedades higroscópicas y de estabilidad dimensional de madera de alcornoque (Quercus suber L.)

Cork oak (Quercus suber L.) wood has a potential for high value uses because of its strength and aesthetic properties but one obstacle is the lack of knowledge of the wood-water relations. Variations in wood equilibrium moisture content, density and dimensions were studied at air temperatures of 22°C and 27°C (representing acclimatized homes and summer non-acclimatized homes, respectively) varying from 80% to 30% of relative humidity. For indoor uses (22-27°C, 50-65% of relative humidity), the wood equilibrium moisture content ranged 12-17% and these values are recommended for the final commercial drying of cork oak wood. The fibre saturation point averaged 27%. Total volumetric shrinkage at 22°C-27°C averaged 12%, the linear shrinkage 8.1-8.5% and 3.6-3.6%, respectively in tangential and radial directions. Anisotropy averaged 2.3. Wood density at 12% moisture content ranged 0.63 to 0.67 g/cm3. The higroscopicity obtained was 0.003. The average tangential differential shrinkage was 0.32 for both temperatures and the average radial differential shrinkage was 0.14 and 0.15, at 22°C and 27°C respectively. The shrinkage factor was 0.90 cm3/g and 0.82 cm3/g, at 22°C and 27°C respectively. Differences between temperatures were only statistically significant at 80-70% of relative humidity.La madera de alcornoque tiene potencial para usos de alto valor debido a su resistencia y propiedades estéticas, pero presenta un obstáculo como es la falta de conocimiento de las relaciones agua-madera. Se han estudiado las variaciones en el contenido de humedad de equilibrio de la madera, la densidad y las dimensiones a temperaturas del aire de 22°C y 27°C (que representa casas climatizadas y casas de verano no aclimatadas, respectivamente) variando entre 80% a 30% de humedad relativa. Para usos interiores (22-27° C, 50-65% de humedad relativa), el equilibrio de humedad de la madera osciló entre el 12-17% y se recomiendan estos valores para el secado final de la madera comercial de alcornoque. El punto de saturación de la fibra promedio es del 27%. La contracción volumétrica total a 22°C-27°C en promedio es de un 12%, la contracción lineal varía entre 8.1-8.5% y 3.6-3.6%, respectivamente en direcciones tangenciales y radiales. La anisotropía promedio fue de 2,3. La densidad de la madera con un contenido de humedad del 12% varió entre 0,63 a 0,67 g/cm3. La higroscopicidad obtenida fue de 0,003. La contracción diferencial tangencial promedio fue de 0,32 para ambas temperaturas y la contracción radial diferencial promedio fue de 0,14 y 0,15, a 22°C y 27°C respectivamente. El factor de contracción fue de 0,90 cm3/g y 0,82 cm3/g, a 22°C y 27°C respectivamente. Las diferencias entre las temperaturas fueron estadísticamente significativas sólo al 80-70% de humedad relativa

Isochronous island bifurcations driven by resonant magnetic perturbations in Tokamaks

Recent evidences show that heteroclinic bifurcations in magnetic islands may be caused by the amplitude variation of resonant magnetic perturbations in tokamaks. To investigate the onset of these bifurcations, we consider a large aspect ratio tokamak with an ergodic limiter composed of two pairs of rings that create external primary perturbations with two sets of wave numbers. An individual pair produces hyperbolic and elliptic periodic points, and its associated islands, that are consistent with the Poincar\'e-Birkhoff fixed point theorem. However, for two pairs producing external perturbations resonant on the same rational surface, we show that different configurations of isochronous island chains may appear on phase space according to the amplitude of the electric currents in each pair of the ergodic limiter. When one of the electric currents increases, isochronous bifurcations take place and new islands are created with the same winding number as the preceding islands. We present examples of bifurcation sequences displaying (a) direct transitions from the island chain configuration generated by one of the pairs to the configuration produced by the other pair, and (b) transitions with intermediate configurations produced by the limiter pairs coupling. Furthermore, we identify shearless bifurcations inside some isochronous islands, originating nonmonotonic local winding number profiles with associated shearless invariant curves

Broadening Risk Factor or Disease Definition as a Driver for Overdiagnosis: A Narrative Review

Medical overuse-defined as the provision of health services for which potential harms exceed potential benefits-constitutes a paradigm of low-value care and is seen as a threat to the quality of care. Value in healthcare implies a precise definition of disease. However, defining a disease may not be straightforward since clinical data do not show discrete boundaries, calling for some clinical judgment. And, if in time a redefinition of disease is needed, it is important to recognize that it can induce overdiagnosis, the identification of medical conditions that would, otherwise, never cause any significant symptoms or lead to clinical harm. A classic example is the impact of recommendations from professional societies in the late 1990s, lowering the threshold for abnormal total cholesterol from 240 mg/dl to 200 mg/dl. Due to these changes in risk factor definition, literally overnight there were 42 million new cases eligible for treatment in the United States. The same happened with hypertension-using either the 2019 NICE guidelines or the 2018 ESC/ECC guidelines criteria for arterial hypertension, the proportion of people overdiagnosed with hypertension was calculated to be between 14% and 33%. In this review, we will start by discussing resource overuse. We then present the basis for disease definition and its conceptual problems. Finally, we will discuss the impact of changing risk factor/disease definitions in the prevalence of disease and its consequences in overdiagnosis and overtreatment (a problem particularly relevant when definitions are widened to include earlier or milder disease).info:eu-repo/semantics/publishedVersio

Produção de capim-massai em sistema silvipastoril na sub-região Meio-Norte do Brasil.

Conduziu-se este estudo na Embrapa Meio-Norte em Teresina, PI, com o objetivo de avaliar a produtividade e os componentes de produção do capim-massai (Panicum maximum x Panicum infestum) sob a copa de quatro leguminosas arbóreas: pau-ferro (Caesalpinia ferrea.), sabiá (Mimosa caesalpiniifolia), bordão-de-velho (Samanea saman) e angico-de-bezerro (Piptadenia moniliformis), e ao pleno sol, constituindo cinco tratamentos com três repetições, no delineamento em blocos ao acaso. Foram avaliados: altura, relação folha colmo (F/C), teor de matéria seca (MS) e massa de forragem (MF - kg de MS ha-1), em plantas com 28 dias de rebrota. Nos tratamentos com as árvores de maior copa as gramíneas apresentaram as maiores alturas, sendo o maior valor encontrado sob a copa do sabiá (60,22 cm) e o menor a pleno sol (34,50 cm). Os menores teores de MS foram observados para o capim sob a copa de sabiá e angico-de-bezerro, 28,19% e 27,01%, respectivamente, valores baixo em contraste com 36,18% ao pleno sol. A MF sob a copa de angico-de-bezerro foi de 872,36 kg de MS ha-1, não diferindo (P>0,05) nos demais tratamentos e variando de 1051,83 a 1229,40 kg de MS ha-1. Os maiores e menores valores de F/C foram registrados, respectivamente, sob a copa de sabiá (4,2) e bordão-de-velho (3,23). Sob a copa de árvores, o capim Massai apresenta menor teor de MS e a maior F/C que a pleno sol, com maior altura de plantas sob copas de maior área. O capim-massai mostra-se eficiente quando manejado em sistema silvipastoril na sub-região Meio-Norte

Current State of Canine Heartworm in Portugal

The favourable geo-climatic conditions in Portugal have made it highly conducive to the development of Dirofilaria immitis in dogs, leading to its identification as an endemic region. This nematode is rapidly spreading across Europe, particularly in northeastern countries. The objective of this study was to provide an updated assessment of the prevalence of this disease in Portuguese dogs, analysing the results in relation to epidemiological and geo-environmental factors, and to identify potential risk factors. A total of 1367 dogs from all continental and insular districts were included in the study and tested for D. immitis antigens. The overall prevalence was found to be 5.9%. It was observed that the disease is spreading northward, with previously unaffected districts now reporting cases, and that the prevalence in coastal districts exceeded that of inland ones. Notably, the Aveiro district exhibited a significant increase in D. immitis prevalence, while in certain districts such as Setúbal, Santarém, Madeira, or Faro, a stabilisation or decrease in prevalence was noted. Furthermore, outdoor and older dogs were found to be at a higher risk of infection. No positive cases were detected in the Azores. Most of the infected dogs were located in areas of high and medium risk of infection. This study underscores the importance of implementing pharmacological prophylaxis, vector control strategies, and public awareness programs to control the spread of this zoonotic disease. © 2024 by the authors.The presented study was supported by ELANCO SPAIN S.L (CN-240/030/162). J.I.M. was supported by the “Grants for the financing of predoctoral contracts” programme of the Universidad de Las Palmas de Gran Canaria (PIFULPGC-2017-CCSALUD-3). I.R.-E. was supported by the University of Salamanca-Banco Santander predoctoral scholarship. A.P.F.-S. and A.C.S.-F. were supported by the Fundação para a Ciência e a Tecnologia through grants UIDB/04308/2020 and UIDB/00772/2020 (doi:10.54499/UIDB/00772/2020), respectively

A protocol to evaluate retinal vascular response using optical coherence tomography angiography

Copyright © 2019 Sousa, Leal, Moreira, do Vale, Silva-Herdade, Aguiar, Dionísio, Abegão Pinto, Castanho and Marques-Neves. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these termsIntroduction: Optical coherence tomography angiography (OCT-A) is a novel diagnostic tool with increasing applications in ophthalmology clinics that provides non-invasive high-resolution imaging of the retinal microvasculature. Our aim is to report in detail an experimental protocol for analyzing both vasodilatory and vasoconstriction retinal vascular responses with the available OCT-A technology. Methods: A commercial OCT-A device was used (AngioVue®, Optovue, CA, United States), and all examinations were performed by an experienced technician using the standard protocol for macular examination. Two standardized tests were applied: (i) the hypoxia challenge test (HCT) and (ii) the handgrip test, in order to induce a vasodilatory and vasoconstriction response, respectively. OCT-A was performed at baseline conditions and during the stress test. Macular parafoveal vessel density of the superficial and deep plexuses was assessed from the en face angiograms. Statistical analysis was performed using STATA v14.1 and p < 0.05 was considered for statistical significance. Results: Twenty-four eyes of 24 healthy subjects (10 male) were studied. Mean age was 31.8 ± 8.2 years (range, 18–57 years). Mean parafoveal vessel density in the superficial plexus increased from 54.7 ± 2.6 in baseline conditions to 56.0 ± 2.0 in hypoxia (p < 0.01). Mean parafoveal vessel density in the deep plexuses also increased, from 60.4 ± 2.2 at baseline to 61.5 ± 2.1 during hypoxia (p < 0.01). The OCT-A during the handgrip test revealed a decrease in vessel density in both superficial (55.5 ± 2.6 to 53.7 ± 2.9, p < 0.001) and deep (60.2 ± 1.8 to 56.7 ± 2.8, p < 0.001) parafoveal plexuses. Discussion: In this work, we detail a simple, non-invasive, safe, and non-costly protocol to assess a central nervous system vascular response (i.e., the retinal circulation) using OCT-A technology. A vasodilatory response and a vasoconstriction response were observed in two physiologic conditions—mild hypoxia and isometric exercise, respectively. This protocol constitutes a new way of studying retinal vascular changes that may be applied in health and disease of multiple medical fields.This study was supported by the Faculty of Medicine of the University of Lisbon, AstraZeneca Foundation – 14th Grant.info:eu-repo/semantics/publishedVersio

Respostas fisiológicas de fêmeas Anglonubiana a manejo nas condições ambientais do Piauí.

A raça Anglonubiana foi pesquisada no Piauí, com avaliação em fêmeas da influência do estágio fisiológico e idade na expressão de adaptação a manejo e condições ambientais na microrregião de Teresina. A estação de monta ocorreu em agosto/setembro de 2008, com final de gestação em novembro/dezembro e lactação em fevereiro de 2009, meses nos quais registrou-se a temperatura retal, frequência cardíaca e respiratória, também escore e peso corporal, mensurados no mesmo animal quando eles estavam ?não prenhe?, ?prenhe? e em ?lactação?, nesses meses, respectivamente. Agrupou-se as fêmeas em quatro idades (mais de 72 meses, de 36 a 72, entre 15 e 36 e marrãs de 12 a 15 meses), com mensuração durante seis dias alternados em duas semanas, leituras entre 14 e 17 h, realizadas à sombra. Utilizou-se delineamento casualizado com análise estatística num fatorial 4x3 (4 idades e 3 estágios), com seis repetições. Considerou-se que cabras Anglonubiana, independemente da idade e estágio fisiológico, recorrem à elevação da frequência respiratória para complementar a dissipação de calor em setembro, mês de temperatura ambiente elevada e baixa umidade do ar. O manejo reprodutivo dessa raça na região deve priorizar ocorrência de gestação/lactação em período do ano mais favorável à homeotermia corporal