Experimental methods on the determination of the mechanical properties of concrete at high temperatures

Até ao momento não existem ainda procedimentos padrão para ensaios a altas temperaturas no betão, pelo que têm sido realizados ensaios a temperaturas elevadas adaptados de ensaios à temperatura ambiente. Os ensaios têm-se dividido entre ensaios a altas temperaturas e residuais após aquecimento e arrefecimento. O primeiro procedimento é mais adequado para a determinação das propriedades mecânicas do betão durante um incêndio enquanto o segundo procedimento é usado para determinar a resistência residual do betão após incêndio. Nesta comunicação apresentam-se os resultados de ensaios realizados por diferentes autores para a determinação das propriedades mecânicas residuais do betão após aquecimento e arrefecimento. Os resultados apresentados dizem respeito a resistências residuais à compressão, tração e flexão e módulo de elasticidade. Os métodos de ensaio aplicados são devidamente descritos e os resultados obtidos são objeto de análises comparativas.ABSTRACT: So far there are no standard procedures for testing concrete at high temperatures which have been conducted according to the ones at ambient temperature. The tests have been divided between tests at high temperatures and residual after heating and cooling. The first procedure is appropriate for determining the mechanical properties of concrete during fire while the second is used to determine the residual mechanical properties of concrete after fire. In this paper are presented the results of tests carried out by different authors for assessing the residual mechanical properties of concrete after heating and cooling. The results presented are respecting to residual compressive, tensile and flexural strength and elasticity modulus. The test methods are described and results obtained are compared

Slow-release N fertilisers are not an alternative to urea for fertilisation of autumn-grown tall cabbage

Tall cabbage (Brassica oleracea var. costata, cv. Penca de Mirandela) is grown in Portugal during autumn and winter months when heavy rains can be expected. In this agrosystem the management of N is a considerable challenge due to the risk of nitrate leaching. Field experiments with tall cabbage and rye were carried out during the growing seasons of 2007/2008 and 2008/2009. The experimental design included three fertilisers that delay N availability by different mechanisms [Floranid permanent, containing isobutylidene diurea (IBDU); Basacote, a polymer-coated fertiliser; and Entec 26, containing 3,4-dimethylpyrazole phosphate (DMPP) as nitrification inhibitor], two urea treatments (total N applied basally; and divided into two equal rates in preplant and topdress application), and a zero N control. The fertilisers were applied at a rate of 120 kg N ha−1. A pot experiment with tall cabbage followed by ryegrass grown in the same pots was carried out in 2007/2008. The fertiliser treatments were essentially the same and a rate of 2.94 g N/pot was applied. Dry matter yield, plant N concentration, plant N recovery and indices of N-use efficiency were compared among the fertiliser treatments. In the pot experiment, soil nitrate concentration was also monitored by using anion exchange membranes inserted directly into the soil. Urea produced mean DM yields statistically higher than control in all crops and in both field and pot experiments and years. No significant differences in DM yield were usually found among fertilised treatments. Basacote produced DM yields often not significantly different from that of control. In the field experiment of tall cabbage, plants recovered 20 and 50% of the amount of N applied, respectively in Basacote and in the other fertilised plots. In the pot experiment, tall cabbage + ryegrass recovered 49.6 and ≈100% of N applied, respectively in Basacote and in the other fertilised plots. From the strictly agronomic point of view, none of the slow-release N materials provided advantages over urea to be advised for this agrosystem, considering also their high cost

Using Patient-Reported Outcome Measures to Evaluate Care for Patients With Inflammatory Chronic Rheumatic Disease

Objectives: Few countries integrate patient-reported outcome measures (PROMs) in routine performance assessment and those that do focus on elective surgery. This study addresses the challenges of using PROMs to evaluate care in chronic conditions. We set out a modeling strategy to assess the extent to which changes over time in self-reported health status by patients with inflammatory chronic rheumatic disease are related to their biological drug therapy and rheumatology center primarily responsible for their care. Methods: Using data from the Portuguese Register of Rheumatic Diseases, we assess health status using the Health Assessment Questionnaire-Disability Index for rheumatic patients receiving biological drugs between 2000 and 2017. We specify a fixed-effects model using the least squares dummy variables estimator. Results: Patients receiving infliximab or rituximab report lower health status than those on etanercept (the most common therapy) and patients in 4 of the 26 rheumatology centers report higher health status than those at other centers. Conclusions: PROMs can be used for those with chronic conditions to provide the patient's perspective about the impact on their health status of the choice of drug therapy and care provider. Care for chronic patients might be improved if healthcare organizations monitor PROMs and engage in performance assessment initiatives on a routine basis.info:eu-repo/semantics/publishedVersio

Effect of maternal country of birth on breastfeeding practices: results from Portuguese GXXI birth cohort

Background: Maternal country of birth has been associated with perinatal health outcomes but less is known regarding breastfeeding practices in contemporary European settings. This study investigated effect of maternal country of birth on breastfeeding initiation and duration by comparing native Portuguese and migrant mothers. Methods: We analyzed data of 7065 children of the Generation XXI (GXXI) birth cohort recruited at birth (2005-06) and followed-up 4 years later. Logistic regression was used to assess the effect of maternal country of birth on breastfeeding initiation. Kaplan-Meier estimate was used to compare breastfeeding duration by maternal country of birth and length of residence by migrant mothers in Portugal. Results: Breastfeeding initiation and the type of breastfeeding practice were similar for native Portuguese and migrant mothers. The migrants had significantly higher median duration in months of any breastfeeding (Odds Ratio [OR] 6.0, 95% Confidence Interval [CI] 5.4,6.6) and exclusive breastfeeding (OR 4.0, 95% CI 3.8,4.2) than native Portuguese mothers (OR 4.0, 95% CI 3.8,4.2 and OR 3.0, 95% CI 2.9,3.0). Migrant mothers who resided in Portugal for either 5 years (OR 6.0, 95% CI 5.5,6.5 and OR 4.0, 95% CI 3.7,4.3) years had similar duration of any breastfeeding or exclusive breastfeeding, in both cases higher than the native Portuguese mothers. No significant differences were found when world regions were compared. Conclusions: Maternal country of birth does not influence breastfeeding initiation and type of feeding practice. However, migrant mothers have longer breastfeeding duration of either exclusive or any breastfeeding, which was not changed by length of residence in Portugal.GXXI was funded by Programa Operacional de Saude-Saude XXI, Quadro Comunitario de Apoio III and Administracao Regional de Saude Norte (Regional Department of Ministry of Health). It has support from Calouste Gulbenkian Foundation and Portuguese Foundation for Science and Technology. Precisely, EPIUnit-Instituto de Saude Publica da Universidade do Porto (POCI-01-0145-FEDER-006862; Ref. UID/DTP/04750/2013); PhD Grant SFRH/BD/111794/2015 (Carina Rodrigues) as well as the individual grants IF/01060/2015 (Ana Cristina Santos) and SFRH/BSAB/113778/2015 (Henrique Barros), co-funded by the FCT and the POCH/FSE Program

Micro-firms way to succeed: How owners manage people

This study explores the configurations of people management practices in micro-firms and their relation with entrepreneurial orientation and firm performance in a four-year window. Based on the ability-, motivation- and opportunity-focused practices framework, we identify configurations of HRM practices used in micro-firms and, in conjugation with entrepreneurial orientation, how they affect employee growth and net income. We analyzed data collected from 114 micro-firm owners combined with firm objective performance measures using Multiple Correspondence Analysis and Cluster Analysis. Results show a taxonomy of three configurations of HRM practices associated with different entrepreneurial orientation strategic postures in micro-firms: “Financial centric HRM practices”, “Operations centric HRM practices”, and “People centric HRM practices”. We assume that configurational methods can help uncover the complexity of the interplay between HRM practices and strategic postures on micro-firm performance. This study contributes to the literature in micro-firms by revealing effective people-related managerial practices on performance.info:eu-repo/semantics/publishedVersio

Impacto de espécies de inverno no rendimento de grãos de culturas de verão e de trigo no inverno subseqüente.

bitstream/CNPT-2010/40292/1/p-bp19.pd

Molecular biology of the dimorphic fungi Paracoccidioides SPP

Paracoccidioides spp, herein commonly referred as Paracoccidioides brasiliensis, is the etiological agent of racoccidioidomycosis (PCM), the most prevalent systemic mycosis endemic in Latin America. Many aspects of the biology of P. brasiliensis remain unknown, in particular its ecology and the apparent lack of a sexual reproduction stage in its life cycle. This review will highlight the current knowledge on the genetics and genomics of P. brasiliensis, its most important putative virulence factors and the challenges for developing genetic tools in this organism. P. brasiliensis is a dimorphic ascomycete fungus belonging to the order Onygenales, family Ajellomycetaceae. The P. brasiliensis pathogenic yeast form is haracterized by a multiple-budding and multinucleate nature, with a highly polymorphic cellular shape. Successful infection and dissemination by P. brasiliensis requires initial interaction of the fungus with host cells. The fungus has to adhere to host cells after which internalization of the fungus takes place. Gp43 is a 43-kDa glycoprotein that participates in the interaction with the host at different levels. There are very few putative virulence factors described in P. brasiliensis,amongthem an extracellular phospholipase B, a 32-kDa haloacid dehalogenase PbHad32 that was shown to bind laminin, fibrinogen, and fibronectin, and to be important for initial adhesion to pulmonary epithelial cells, the pigment melanin, and the Rho-like GTPase PbCdc42. The morphological transition of P. brasiliensis from mycelium to the yeast form is a key process for the infectivity of the fungus. There are several transcriptional profiling studies addressing which genes have increased or decreased mRNA accumulation during mycelium-to-yeast transitions. Functional genomics studies in P. brasiliensis have been hampered by the absence of efficient molecular techniques that enable targeted gene inactivation in this fungus. However, an optimized Agrobacterium tumefaciens-mediated transformation method has been developed and was used to knock-down expression of the genes encoding the Rho-like GTPase PbCdc42 and the HAD-type hydrolase PbHad32. A challenge for the future is the development of mutagenesis methods that allow for the creation of targeted insertional gene mutants in Paracoccidioides spp. The complete genome sequencing of three isolates of Paracoccidioides species provides the opportunity to perform more complete evaluations of the transcriptomic and proteomic data, and to understand the biology and virulence of these important pathogenic fungi.Fundação para a Ciência e Tecnologia (FCT) - Bolsa nº PTDC/BIA-MIC/108309/2008Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento. Científico e Tecnológic

Using patient-reported outcome measures to evaluate care for patients with inflammatory chronic rheumatic disease

Objectives: Few countries integrate Patient-Reported Outcome Measures (PROMs) in routine performance assessment, and those that do focus on elective surgery. This study addresses the challenges of using PROMs to evaluate care in chronic conditions. We set out a modelling strategy to assess the extent to which changes over time in self-reported health status by patients with inflammatory chronic rheumatic disease are related to their biological drug therapy and Rheumatology centre primarily responsible for their care. Methods: Using data from the Portuguese Register of Rheumatic Diseases, we assess the health status using the Health Assessment Questionnaire-Disability Index (HAQ-DI) for rheumatic patients receiving biological drugs between 2000 and 2017. We employ a fixed effects model using the Least Squares Dummy Variables estimator. Results: Patients receiving infliximab or rituximab report lower health status than those on etanercept (the most common therapy) and patients in 4 of the 26 Rheumatology centres report higher health status than those at other centres. Conclusions: PROMs can be used for those with chronic conditions to provide the patient’s perspective about the impact on their health status of the choice of drug therapy and care provider. Care for chronic patients might be improved if healthcare organisations monitor PROMs and engage in performance assessment initiatives on a routine basis

Primary productivity evolution during the latest Holocene (2,000 yr) off Oporto (Portuguese Margin)

European Geosciences Union General Assembly 2008 (EGU 2008), Vienna, Austria, April 13-18, 200

Quasivariational solutions for first order quasilinear equations with gradient constraint

We prove the existence of solutions for an evolution quasi-variational inequality with a first order quasilinear operator and a variable convex set, which is characterized by a constraint on the absolute value of the gradient that depends on the solution itself. The only required assumption on the nonlinearity of this constraint is its continuity and positivity. The method relies on an appropriate parabolic regularization and suitable {\em a priori} estimates. We obtain also the existence of stationary solutions, by studying the asymptotic behaviour in time. In the variational case, corresponding to a constraint independent of the solution, we also give uniqueness results