250 research outputs found
Identidad profesional y conocimiento matemático para la enseñanza de maestros en formación
En este estudio se pretende obtener una mayor comprensión sobre la identidad profesional en formación de estudiantes para maestro y las implicaciones para los programas de formación del profesorado. Se indaga sobre las reflexiones realizadas por estudiantes para maestro de educación primaria concernientes a sus experiencias relativas a la enseñanza y aprendizaje de las matemáticas y a conocimientos que estiman necesarios para enseñar matemáticas. Los resultados obtenidos revelan los aspectos que estos estudiantes destacan como elementos constitutivos de la identidad profesional del maestro haciendo mención a los componentes propios del proceso de enseñanza y aprendizaje de las matemáticas. Se propone una aproximación de la caracterización de la identidad profesional a través del conocimiento matemático para la enseñanza
‘The International Teacher Leadership project,’ a case of international action research.
Copyright CARNThe paper arises from the International Teacher Leadership project, a research and development project involving researchers and practitioners in 14 European countries. The paper provides a conceptual exploration of the idea of teacher leadership and its role in educational reform, central to which is the idea that teachers, regardless of their level of power and organisational position, can engage in the leadership of enquiry-based development activity aimed at influencing their colleagues and embedding improved practices in their schools. The paper provides an outline of the project’s methodology which builds on that used in the Carpe Vitam Leadership for Learning project (Frost, 2008a). It is a form of collaborative
action research which is highly developmental and discursive. It seeks to identify principles, strategies and tools that can be applied in a range of cultural settings. The paper includes a thematic analysis of the cultural contexts and policy environments of the participating countries in order to identify the obstacles to teacher leadership and to inform the nature of the support strategies employed
RIGHT TO HOUSING: BETWEEN REGULATORY ADVANCEMENT AND INSTITUTIONAL PRACTICE. THE SOCIAL RENTAL POLICY IN RIO DE JANEIRO
doi: 10.12957/geouerj.2016.15464
O objetivo do trabalho é discutir o avanço dos direitos sociais no Brasil, destacando o direito à moradia, cuja efetividade não depende da propriedade imobiliária, mas de outras estratégias, dentre as quais destacamos o aluguel social. A experiência no Estado e Município do Rio de Janeiro será utilizada como referência do uso deste instrumento. A legislação que protege o direito à moradia será abordada, assim como sua evolução no ordenamento jurídico nacional e internacional. A experiência carioca será apresentada com base em alguns casos emblemáticos oriundos da atuação do Núcleo de Terras e Habitação da Defensoria Pública do Rio de Janeiro, especialmente depois das chuvas de abril de 2010, onde a política de aluguel social foi amplamente utilizada entre a população que ficou desabrigada
Estudi comparatiu d’eliminació de compostos fenòlics utilitzant la membrana NF-99 de poliamida
[SPA] Actualmente los procesos físicos basados en la tecnología de membranas se han aplicado satisfactoriamente para el tratamiento de aguas residuales, siendo la nanofiltración y la ósmosis inversa los métodos más adecuados para la eliminación de microcontaminantes orgánicos como los compuestos fenólicos. En este trabajo se ha realizado un estudio comparativo sobre el comportamiento de la membrana NF-99 en el proceso de eliminación de fenol, 4-clorofenol y 4-cloro-2-metilfenol. Además, la membrana NF-99 se ha caracterizado con una disolución de cloruro de magnesio, estudiando la influencia de la presión de operación sobre los parámetros característicos del sistema, flujo de permeado y coeficiente de rechazo, antes de realizar la experimentación y tras la realización de los ensayos. De la caracterización de la membrana se obtuvo unos valores en los flujos de permeado y en los coeficientes de rechazo prácticamente constantes, tanto en los ensayos realizados en las condiciones iniciales como en las condiciones finales. El compuesto 4-cloro-2-metilfenol obtuvo los mayores coeficientes de rechazo en todas las condiciones de presión, concentración de alimentación y pH ensayados.[ENG] Nowadays the physical processes based on membrane technology have been successfully applied for the treatment of wastewater being nanofiltration and reverse osmosis the best methods for removing organic micropollutants such as phenolic compounds. In this work a comparative study on the behaviour of the NF-99 membrane in the process of elimination of phenol, 4-chlorophenol and 4-chloro-2-methylphenol has been carried out. In addition, the NF-99 membrane has been characterized by a solution of magnesium chloride, studying the influence of the operating pressure on the characteristic parameters of the system, the permeate flux and rejection coefficient, before and after the experimental series. From the membrane characterization, nearly constant values of the permeate flux and rejection coefficients were obtained for both the initial and the final conditions. The compound 4-chloro-2-methylphenol obtained higher rejection coefficients in all conditions of pressure, feed concentration and pH tested.[CAT] Actualment els processos fisics basats en la tecnologia de membranes s’han aplicat satisfactoriament pel tractament d’aigues residuals, i la nanofiltracio i l’osmosi inversa son els metodes mes adequats per a l’eliminacio de microcontaminants organics com els compostos fenolics. En aquest treball s’ha realitzat un estudi comparatiu sobre el comportament de la membrana NF-99 en el proces d’eliminacio de fenol, 4-clorofenol i 4-cloro-2-metilfenol. A mes, la membrana NF-99 s’ha caracteritzat amb una dissolucio de clorur de magnesi, estudiant la influencia de la pressio d’operacio sobre els parametres caracteristics del sistema, flux de permeacio i coeficient de rebuig, abans de realitzar l’experimentacio i despres de la realitzacio dels assajos. De la caracteritzacio de la membrana es van obtenir uns valors en els fluxos de permeacio i en els coeficients de rebuig practicament constants, tant en els assajos realitzats en les condicions inicials com en les condicions finals. El compost 4-cloro-2-metilfenol va obtenir els majors coeficients de rebuig a totes les condicions de pressio, concentracio d’alimentacio i pH assajats.Este trabajo es resultado del proyecto de investigación 08683/PI/08, financiado por la Fundación Séneca, Agencia de Ciencia y Tecnología de la Región de Murcia (España). M.D. Murcia fue beneficiaria de la beca Juan de la Cierva de MICINN
Aquaporin-4 Antibodies Are Not Related to HTLV-1\ud Associated Myelopathy
Introduction: The seroprevalence of human T-cell leukemia virus type 1 (HTLV-1) is very high among Brazilians (,1:200).\ud
HTLV-1 associated myelopathy or tropical spastic paraparesis (HAM/TSP) is the most common neurological complication of\ud
HTLV-1 infection. HAM/TSP can present with an acute/subacute form of longitudinally extensive myelitis, which can be\ud
confused with lesions seen in aquaporin-4 antibody (AQP4-Ab) positive neuromyelitis optica spectrum disorders (NMOSD)\ud
on MRI. Moreover, clinical attacks in patients with NMOSD have been shown to be preceded by viral infections in around\ud
30% of cases.\ud
Objective: To evaluate the frequency of AQP4-Ab in patients with HAM/TSP. To evaluate the frequency of HTLV-1 infection\ud
in patients with NMOSD.\ud
Patients and Methods: 23 Brazilian patients with HAM/TSP, 20 asymptomatic HTLV-1+ serostatus patients, and 34 with\ud
NMOSD were tested for AQP4-Ab using a standardized recombinant cell based assay. In addition, all patients were tested for\ud
HTLV-1 by ELISA and Western blotting.\ud
Results: 20/34 NMOSD patients were positive for AQP4-Ab but none of the HAM/TSP patients and none of the\ud
asymptomatic HTLV-1 infected individuals. Conversely, all AQP4-Ab-positive NMOSD patients were negative for HTLV-1\ud
antibodies. One patient with HAM/TSP developed optic neuritis in addition to subacute LETM; this patient was AQP4-Ab\ud
negative as well. Patients were found to be predominantly female and of African descent both in the NMOSD and in the\ud
HAM/TSP group; Osame scale and expanded disability status scale scores did not differ significantly between the two\ud
groups.\ud
Conclusions: Our results argue both against a role of antibodies to AQP4 in the pathogenesis of HAM/TSP and against an\ud
association between HTLV-1 infection and the development of AQP4-Ab. Moreover, the absence of HTLV-1 in all patients\ud
with NMOSD suggests that HTLV-1 is not a common trigger of acute attacks in patients with AQP4-Ab positive NMOSD in\ud
populations with high HTLV-1 seroprevalence.This study received financial support from the Brazilian government agencies FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo - www. fapesp.br/en) and CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - www.capes.gov.br). The work of S.J. and B.W. was supported by research grants from Bayer Schering Healthcare and from Merck Serono. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Economic analysis of antenatal screening for human T-cell lymphotropic virus type 1 in Brazil: an open access cost-utility model
BACKGROUND: Human T-cell lymphotropic virus type 1 (HTLV-1) is a retrovirus that causes severe diseases, such as aggressive cancer or progressive neurological disease. HTLV-1 affects mainly people in areas with low human development index and can be transmitted from mother to child, primarily through breastfeeding. Refraining from breastfeeding is an effective intervention to reduce the risk of infection in infants. However, HTLV-1 antenatal screening is not offered globally. According to WHO, the scarcity of cost-effectiveness studies is considered one of the major barriers to the implementation of policies to prevent HTLV-1 infection. Therefore, this study aimed to assess the cost-effectiveness of antenatal screening and postnatal interventions to prevent HTLV-1 mother-to-child transmission in Brazil and to develop an open-access, editable, mathematical model that can be used by other countries and regions to assess different scenarios. METHODS: In this cost-utility analysis, we constructed a decision tree and a Markov model to assess the cost-effectiveness of HTLV-1 antenatal screening and postnatal interventions (ie, avoidance of breastfeeding, by suppression of lactation with cabergoline, and provision of formula feed) to reduce transmission. For our model, we used data from Brazil and we took the perspective of the public health-care system to estimate costs. FINDINGS: The implementation of both screening and interventions would result in the prevention of 1039 infections in infants every year in Brazil with an incremental cost-effectiveness ratio (ICER) of US18 107·74 per QALY). HTLV-1 prevalence in pregnant women, the risk of HTLV-1 transmission when breastfeeding lasts for 6 months or more, and the cost of screening tests were the variables with the largest effect on ICER. INTERPRETATION: HTLV-1 antenatal screening is cost-effective in Brazil. An open-access model was developed, and this tool could be used to assess the cost-effectiveness of such policy globally, favouring the implementation of interventions to prevent HTLV-1 mother-to-child transmission worldwide. FUNDING: None. TRANSLATIONS: For the Portuguese and Spanish translations of the abstract see Supplementary Materials section
About females and males: continuity and discontinuity in flies
Through the decades of relentless and dedicated studies in Drosophila melanogaster, the pathway that governs sexual development has been elucidated in great detail and has become a paradigm in understanding fundamental cell-fate decisions. However, recent phylogenetic studies show that the molecular strategy used in Drosophila deviates in some important aspects from those found in other dipteran flies and suggest that the Drosophila pathway is likely to be a derivative of a simpler and more common principle. In this essay, I will discuss the evolutionary plasticity of the sex-determining pathway based on studies in the common housefly, Musca domestica. Diversification appears to primarily arise from subtle differences in the regulation of the key switch gene transformer at the top of the pathway. On the basis of these findings I propose a new idea on how the Drosophila pathway may have evolved from a more archetypal system such as in M. domestica. In essence, the arrival of an X counting mechanism mediated by Sex-lethal to compensate for X linked gene dose differences set the stage for an intimate coupling of the two pathways. Its precedent recruitment to the dosage compensation pathway allowed for an intervention in the regulation of transformer where it gradually and eventually' completely substituted for a need of transformer autoregulation
Mining gene functional networks to improve mass-spectrometry-based protein identification
Motivation: High-throughput protein identification experiments based on tandem mass spectrometry (MS/MS) often suffer from low sensitivity and low-confidence protein identifications. In a typical shotgun proteomics experiment, it is assumed that all proteins are equally likely to be present. However, there is often other evidence to suggest that a protein is present and confidence in individual protein identification can be updated accordingly
Integrating shotgun proteomics and mRNA expression data to improve protein identification
Motivation: Tandem mass spectrometry (MS/MS) offers fast and reliable characterization of complex protein mixtures, but suffers from low sensitivity in protein identification. In a typical shotgun proteomics experiment, it is assumed that all proteins are equally likely to be present. However, there is often other information available, e.g. the probability of a protein's presence is likely to correlate with its mRNA concentration
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