957 research outputs found

    Para o estudo da evolução do ensino e da formação em administração educacional em Portugal

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    Estudos sobre a evolução do ensino de disciplinas, na formação de professores em Portugal, são recentes. O controle burocrático centralizado reteve as dimensões do controle político-administrativo. De certo modo, protegeu a esfera educativa das influências modernizantes, do capitalismo industrial e das lógicas mercantis e gerencialistas. Defendeu a educação do domínio político, da intervenção de movimentos sociais, das propagandas de ideais democráticos e da cidadania. A utilização da designação "Administração educacional" ilustra as dificuldades sentidas, ao longo dos últimos anos, em termos da construção acadêmica de uma área, seja pela falta de tradição, seja pelos antecedentes históricos.In Portugal, studies about the evolution of disciplines teaching in the teachers formation are recent. The centralized bureaucratic control has held back the dimensions of politic administrative control. In a certain way, it has protected the education against the new-fashioned influences, manufacturing capitalism, and mercantile and managerial logics. This centralized bureaucratic control has also profected the education against the politic dominion, the intervention of social movements, the advertising of democratic ideals, and against the citizenship. The use of the term "Educational administration" shows the difficulties met by the searchers along the latest years, since there is no tradiction nor historic antecedence

    LV Mass Assessed by Echocardiography and CMR, Cardiovascular Outcomes, and Medical Practice

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    The authors investigated 3 important areas related to the clinical use of left ventricular mass (LVM): accuracy of assessments by echocardiography and cardiac magnetic resonance (CMR), the ability to predict cardiovascular outcomes, and the comparative value of different indexing methods. The recommended formula for echocardiographic estimation of LVM uses linear measurements and is based on the assumption of the left ventricle (LV) as a prolate ellipsoid of revolution. CMR permits a modeling of the LV free of cardiac geometric assumptions or acoustic window dependency, showing better accuracy and reproducibility. However, echocardiography has lower cost, easier availability, and better tolerability. From the MEDLINE database, 26 longitudinal echocardiographic studies and 5 CMR studies investigating LVM or LV hypertrophy as predictors of death or major cardiovascular outcomes were identified. LVM and LV hypertrophy were reliable cardiovascular risk predictors using both modalities. However, no study directly compared the methods for the ability to predict events, agreement in hypertrophy classification, or performance in cardiovascular risk reclassification. Indexing LVM to body surface area was the earliest normalization process used, but it seems to underestimate the prevalence of hypertrophy in obese and overweight subjects. Dividing LVM by height to the allometric power of 1.7 or 2.7 is the most promising normalization method in terms of practicality and usefulness from a clinical and scientific standpoint for scaling myocardial mass to body size. The measurement of LVM, calculation of LVM index, and classification for LV hypertrophy should be standardized by scientific societies across measurement techniques and adopted by clinicians in risk stratification and therapeutic decision making

    On the Computational Complexity of the Strong Geodetic Recognition Problem

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    A strong geodetic set of a graph~G=(V,E)G=(V,E) is a vertex set~SV(G)S \subseteq V(G) in which it is possible to cover all the remaining vertices of~V(G)SV(G) \setminus S by assigning a unique shortest path between each vertex pair of~SS. In the Strong Geodetic problem (SG) a graph~GG and a positive integer~kk are given as input and one has to decide whether~GG has a strong geodetic set of cardinality at most~kk. This problem is known to be NP-hard for general graphs. In this work we introduce the Strong Geodetic Recognition problem (SGR), which consists in determining whether even a given vertex set~SV(G)S \subseteq V(G) is strong geodetic. We demonstrate that this version is NP-complete. We investigate and compare the computational complexity of both decision problems restricted to some graph classes, deriving polynomial-time algorithms, NP-completeness proofs, and initial parameterized complexity results, including an answer to an open question in the literature for the complexity of SG for chordal graphs

    Long-lived NIR emission in sulfur-doped zeolites due to the presence of [S3]2- clusters

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    Funding Information: The authors want to acknowledge the Portuguese Foundation for Science and Technology for funding through the grants SFRH/BD/145009/2019 and SFRH/BPD/120599/2016 , the individual contract 2020.00252. CEECIND and several projects PTDC/QUI-QFI/32007/2017, UIDB/04565/2020, UIDP/04565/2020, LA/P/0140/2020, LAQV-REQUIMTE (LA/P/0008/2020, UIDB/50006/2020 and UIDP/50006/2020), VICARTE (UIDP/00729/2020, UIDB/00729/2020) and C2TN (UIDB/04349/2020). MOSTMICRO-ITQB R&D Unit (UIDB/04612/2020, UIDP/04612/2020) and LS4FUTURE Associated Laboratory (LA/P/0087/2020) and by European Union's Horizon 2020 research and innovation program under grant agreement No. 810856. Funding Information: The authors want to acknowledge the Portuguese Foundation for Science and Technology for funding through the grants SFRH/BD/145009/2019 and SFRH/BPD/120599/2016, the individual contract 2020.00252. CEECIND and several projects PTDC/QUI-QFI/32007/2017, UIDB/04565/2020, UIDP/04565/2020, LA/P/0140/2020, LAQV-REQUIMTE (LA/P/0008/2020, UIDB/50006/2020 and UIDP/50006/2020), VICARTE (UIDP/00729/2020, UIDB/00729/2020) and C2TN (UIDB/04349/2020). MOSTMICRO-ITQB R&D Unit (UIDB/04612/2020, UIDP/04612/2020) and LS4FUTURE Associated Laboratory (LA/P/0087/2020) and by European Union's Horizon 2020 research and innovation program under grant agreement No. 810856. Publisher Copyright: © 2023 The Author(s)The exploration of novel long-lived near-infrared (NIR) luminescent materials has attracted significant attention due to their applications in optical communications, anticounterfeiting, and bioimaging. However, these materials usually present low photoluminescence quantum yields and low photo- and chemical stability. Novel emitters that overcome these limitations are in demand. In this study, NIR emission was achieved using widely available, sustainable, and non-toxic materials through the synthesis of sulfur-doped zeolites, with different S/Cl ratios. With a combination of computational calculations (TD-DFT) and spectroscopic data, this emission was assigned to the radiative decay of excited triplet states of [S3]2- clusters, which resulted in a remarkably high Stokes shift (1.97 eV, 440 nm) and an average decay time of 0.54 ms. These new materials present high stability, external quantum efficiency of up to 17%, and a long-lived NIR emission, placing these compounds in a unique position to be used in applications demanding NIR emitters.publishersversionpublishe

    A Central Limit Theorem for intransitive dice

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    Intransive dice D(1),,D()D^{(1)}, \ldots, D^{(\ell)} are dice such that D(1)D^{(1)} has advantage with respect to D(2)D^{(2)}, dice D(2)D^{(2)} has advantage with respect to D(3)D^{(3)} and so on, up to D()D^{(\ell)}, which has advantage over D(1)D^{(1)}. In this twofold work, we present: first, (deterministic) results on existence of general intransitive dice. Second and mainly, a central limit theorem for the vector of normalized victories of a die against the next one in the list when the faces of a die are i.i.d.\ random variables and all dice are independent, but different dice may have distinct distributions associated to, as well as they may have distinct number of faces. From this central limit theorem we derive a criteria to assure that the asymptotic probability of observing intransitive dice is null, which applies for many cases, including all continuous distributions and many discrete ones.Comment: 37 pages, 3 figure

    Automatic miniaturized flow methodology with in-line solid-phase extraction for quinine determination in biological samples

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    The present work describes an analytical platform based on a multipumping flow injection analysis (MPFS) technique combined with in-line solid-phase extraction (SPE). The flow network has been tested with the determination of quinine in biological samples using fluorometry as the detection technique. Amberlite XAD-4 resin has been used as a solid phase and the implementation of a pH control strategy resulted in a simple and environmental approach for the preconcentration of quinine. Two solenoid valves allowed the deviation of the flow towards the resin column to carry out SPE procedures. The influence of parameters such as concentration, flow rate and volume of the different solutions on the sensitivity and performance of the MPFS was studied. Dynamic calibration ranges (0.78–150 ng mL 1) for quinine determination were applied by using a variable sample volume (120– 1000 mL). The developed methodology provided high relative extraction recoveries from human urine samples (85–115%). The proposed automatic methodology turns out to be very efficient and sustainable compared to the available procedures and it could prove to be an attractive alternative tool to perform in-line sample pre-treatment and subsequent direct determination of relevant organic compounds in pharmaceutical and clinical analyses

    Fatty acids profile of Serra da Estrela PDO cheeses and respective atherogenic and thrombogenic indices

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    Purpose: This study aims to determine the physicochemical and fatty acids composition of Serra da Estrela cheese (SEC), as well as health-related lipid indices, like the atherogenic and thrombogenic indices, and to evaluate the influence of producer, geographical origin and production date. Design/methodology/approach: All 24 SEC produced between November 2017 and March 2018 were collected at selected certified producers and analyzed by NIR spectrophotometer and by GC. Data were statistically evaluated by chemometric tools. Findings: In all evaluated SEC, 23 fatty acids were quantified. Cheese origin influenced nutritional and health-related lipid indices). The cheeses were characterized by a relative high abundance of saturated fatty acids (67-76%), followed by a medium content of monounsaturated fatty acids (17-25%) and by low level of polyunsaturated fatty acids (5-7%). A putative positive association between cheese consumption and healthy lipid indices could be reached. Practical implications The contents of some medium and long chain fatty acids as well as of nutritional and health indices were influenced by cheese producer, geographical origin and production date pointing out the need for standardizing production procedures. Social implications The SEC plays a key role in the local economy, being an endogenous product with unique sensory characteristics and nutritional potential, for which the knowledge of the lipids profile and health indices is of utmost relevance. Originality/value SEC is an iconic Portuguese cheese with Protected Designation of Origin. Based on the results, like health-related lipid indices, evaluated for the first time, a positive association between cheese consumption and healthy lipid indices could be envisaged.This work was financially supported by Associate Laboratory LSRE-LCM - UID/EQU/50020/2019, strategic funding UID/BIO/04469/2019-CEB and BioTecNorte operation (NORTE-01-0145-FEDER000004), and strategic project PEst-OE/AGR/UI0690/2014–CIMO funded by national funds through FCT/MCTES (PIDDAC). The authors would also like to acknowledge the funding provided by the approved Project, with reference 02/SAICT/2016/23290, entitled Characterization and Valorization of QSE PDO and its ability for health promotion (QCLASSE), financed by FCT.info:eu-repo/semantics/publishedVersio

    Preliminary Analysis of the Use of Construction Waste to Replace Conventional Aggregates in Concrete

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    This work aims to study the influence of using construction and demolition waste in the replacement of coarse and fine aggregate to produce recycled aggregate concrete (RAC). A moderate compressive strength concrete made with usual fine and coarse aggregate was used as a benchmark material. Compressive and split tensile tests were performed using 120 cylindrical concrete specimens with 150 mm diameter and 300 mm length. Four-point flexural tests in reinforced beams made with conventional concrete and RAC were performed. The results obtained showed that the use of recycled fine aggregates, in both percentages of substitution investigated-50% and 100%-did not generate any deleterious influence on the values of compressive strength and split tensile strength of the RACs produced. Tin fact, the mechanical strengths of RACs produced with recycled fine aggregate were equal or higher than those from the reference concrete. The same behavior was not observed, however, when the recycled coarse aggregate was used. For this case, decreases in concrete mechanical strengths were observed, especially in compressive strength, with values around 35% lower when compared to the reference concrete. Tensile mechanical tests results confirmed the excellent behavior of all RACs made with replacement of usual fine aggregates by recycled. Bending tests performed in reinforced RAC beams had as objective to evaluate the deformation profile of the beams. The obtained results showed that RAC beams with full replacement of usual fine aggregate by the recycled aggregates have presented little changes in the global behavior, an aspect that encourages its use

    Diphenyl diselenide, a simple glutathione peroxidase mimetic, inhibits human LDL oxidation in vitro

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    Oxidative modification of low-density lipoprotein (LDL) represents an important factor in atherogenesis. In the present study, we have investigated the antioxidant capability of diphenyl diselenide (PhSe)2, a simple organoseleno compound, against copper (Cu2+) and peroxyl radical-induced human LDL oxidation in vitro. In initial studies using human serum, (PhSe)2 caused a dose-dependent inhibition of Cu2+-induced lipid peroxidation, which was correlated to thiol consumption. (PhSe)2 increased lipid peroxidation lag phase and decreased lipid peroxidation rate in isolated human LDL, evaluated by measuring both conjugated diene (CD) and thiobarbituric acid reactive substances (TBARS) levels. Consistent with these observations, (PhSe)2 showed a marked inhibitory effect on 2,2-azobis(2-amidinopropane dihydrochloride) (AAPH)-induced oxidation of LDL or parinaric acid (PnA) incorporated into LDL. (PhSe)2 also displayed a dose-dependent protective effect against Cu2+-induced lipid peroxidation in rat aortic slices. Interestingly, besides the antioxidant effects of (PhSe)2 toward the lipid moieties of LDL, which was related to its thiol-peroxidase activity, protein moieties from human isolated LDL were also protected against Cu2+-induced oxidation. The results presented herein are the first to show that (i) (PhSe)2 inhibits lipid peroxidation in human isolated LDL in vitro, (ii) this phenomenon is related to its thiol-peroxidase activity, and (iii) this chalcogen also prevents the oxidation of protein moieties of human LDL. Taken together, such data render (PhSe)2 a promising molecule for pharmacological studies with respect to the atherogenic process.http://www.sciencedirect.com/science/article/B6T12-4S21TS2-1/1/38250cf8bae4a4195ccd8905cf5c2a8
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