709 research outputs found
Sustaining interaction in a mathematical community of practice
This paper focuses on an activity in which students explore sequences through a game, using ToonTalk programming and a web-based collaboration system. Our analytical framework combines theory of communities of practice with domain epistemology. We note three factors which influence the length and quality of interactions: facilitation, reciprocation and audience-awareness
Cinco anos de etwinning : o estado da arte da investigação
O eTwinning, com início em 2005, aparece definido, no seu portal (www.etwinning.net), como uma Comunidade de Escolas da Europa que se enquadra numa das acções do programa eLearning da União Europeia. Tem como objectivo promover o estabelecimento de parcerias entre escolas europeias para o desenvolvimento de projectos colaborativos.
Esta comunicação pretende fazer uma revisão de literatura relativamente aos trabalhos de investigação e/ou reflexão sobre os projectos eTwinning que decorreram entre 2005 e 2010.eTwinning project, promoting since 2005, as a Community of Schools in Europe (www.etwinning.net) that fits an action under the Lifelong Learning Programme of the European
Union. The eTwinning aim is promoting partnerships between European schools for the development of collaborative projects. This paper made a little review the literature about the research and / or reflection on the eTwinning projects that took place between 2005 and 2010
Hematopoietic stem cell transplantation for neurological disorders: a focus on inborn errors of metabolism
Copyright © 2022 de Vasconcelos and Lacerda. 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 terms.Hematopoietic stem cells have been investigated and applied for the treatment of certain neurological disorders for a long time. Currently, their therapeutic potential is harnessed in autologous and allogeneic hematopoietic stem cell transplantation (HSCT). Autologous HSCT is helpful in immune-mediated neurological diseases such as Multiple Sclerosis. However, clinical benefits derive more from the immunosuppressive conditioning regimen than the interaction between stem cells and the nervous system. Mainly used for hematologic malignancies, allogeneic HSCT explores the therapeutic potential of donor-derived hematopoietic stem cells. In the neurological setting, it has proven to be most valuable in Inborn Errors of Metabolism, a large spectrum of multisystem disorders characterized by congenital deficiencies in enzymes involved in metabolic pathways. Inborn Errors of Metabolism such as X-linked Adrenoleukodystrophy present with brain accumulation of enzymatic substrates that result in progressive inflammatory demyelination. Allogeneic HSCT can halt ongoing inflammatory neural destruction by replacing hematopoietic-originated microglia with donor-derived myeloid precursors. Microglia, the only neural cells successfully transplanted thus far, are the most valuable source of central nervous system metabolic correction and play a significant role in the crosstalk between the brain and hematopoietic stem cells. After transplantation, engrafted donor-derived myeloid cells modulate the neural microenvironment by recapitulating microglial functions and enhancing repair mechanisms such as remyelination. In some disorders, additional benefits result from the donor hematopoietic stem cell secretome that cross-corrects neighboring neural cells via mannose-6-phosphatase paracrine pathways. The limitations of allogeneic HSCT in this setting relate to the slow turnover of microglia and complications such as graft-vs.-host disease. These restraints have accelerated the development of hematopoietic stem cell gene therapy, where autologous hematopoietic stem cells are collected, manipulated ex vivo to overexpress the missing enzyme, and infused back into the patient. With this cellular drug vehicle strategy, the brain is populated by improved cells and exposed to supraphysiological levels of the flawed protein, resulting in metabolic correction. This review focuses on the mechanisms of brain repair resulting from HSCT and gene therapy in Inborn Errors of Metabolism. A brief mention will also be made on immune-mediated nervous system diseases that are treated with this approach.info:eu-repo/semantics/publishedVersio
Equilibrium Bid-Ask Spread of European Derivatives in Dry Markets
In the framework of incomplete markets, due to the non-existence of trade at some points in time, and using a partial equilibrium analysis, we show how the bid-ask spread of an European derivative is generated.
We also find conditons for the existence of the spread. These conditions concern the market structure of the maret-makers, which can be a oligolopoly with price competition or a monopoly, as well as the riskaversion of the demand and supply of the market.N/
Immunologic reconstitution after allogeneic stem cell transplant
© Ordem dos MédicosPatients submitted to allogeneic stem cell transplantation have a prolonged immunodeficiency, extending beyond one year post-transplant. The immune reconstitution after an allogeneic stem cell transplant is dependent upon several factors, such as the age of the recipient, the degree of in vivo or in vitro T-cell depletion, the emergence and eventual treatment of graft versus host disease. While neutrophils and NK cells recover normally within 2 months of transplant, the reconstitution of B- and T-cell immunity is significantly slower. In fact, it is impossible to dissociate the emergence of new B-lymphocytes from thymopoiesis, which appears to be determinant for the normal reconstitution of acquired immunity post-transplant. The serial analysis of T cell counts and its subsets, as well as T-cell function and, more recently, of T-cell receptor excision circles, show a delay in T-cell reconstitution in adult patients, patients with extensive chronic graft versus host disease and in the first 9 months post-transplant in recipients of T-cell depleted grafts. The incidence of opportunistic infections is higher in this population. Therefore, with the aim of reducing post-transplant mortality, the development of new strategies for the acceleration of immune reconstitution is crucial. One possibility is the use of adoptive cellular immunotherapy with donor leukocytes in order to boost the incipient donor's immune system in the receptor. Preliminary studies in animal models also suggest that interleukin-7 and keratinocyte growth factor improve thymopoiesis, thereby stimulating the immune reconstitution post-transplant.info:eu-repo/semantics/publishedVersio
The importance of supervision in the support and regulation of the teaching-learning process
Pedagogical supervision takes on particular relevance in the context of the education system and, more particularly, in school, taking as an essential condition of critical approach, self-regulating and (re)guidance of teaching practices and professionalism of teachers, with special attention to the work done in the classroom. Pedagogical supervision may, through appropriate supervising processes, enable teachers to take a different view of learning through the sharing of differentiated, motivating, stimulating and innovative strategies.This paper reports on a project carried out by a team of teachers from the School of Education of Viseu, in a school in the city of Viseu, and is based on an in-depth study of the work developed by the teachers of the Primary Education in the framework of their professional practices. The study aims at understanding and clarifying in depth the curricular practices of teachers’ professional action, in order to clarify how this action promotes students' more or less consolidated learning. The objective of the research is that the analysis process, through the suggestion of some recommendations, allows a better regulation of the teaching-learning process of the Primary Education students and creates conditions that facilitate the improvement of students' internal and external school/academic results of this level of education.
In order to reach the proposed objectives, supported by a qualitative methodology, we used as instruments of data collection, document analysis and direct observation. The documentary analysis was based on the fundamental curricular management tools of the school and the observation of curricular practices in the context of the classroom.The study allows us to conclude that it is necessary to make some changes in the curricular practices of the school, at the level of pedagogical and didactic management of teachers, as well in the scope of continuous training, valuing, among others, the tasks of awareness of theories, knowledge, needs, priorities and didactic and pedagogical dilemmas. In the conclusions of the study, proposals for training in pedagogical innovation are also suggested.info:eu-repo/semantics/publishedVersio
Transplante autólogo de células estaminais em leucemiamielóide aguda: factores com Influência na sobrevida: experiência de 13 anos de uma Instituição
© Ordem dos MédicosWe report our results of autologous stem cell transplantation (SCT) in patients with AML during the last 13 years. Between August 1990 and December 2003, 42 patients with acute myeloid leukemia (AML) received an autologous SCT. Patients were classified as standard risk if first complete remission (CR) was induced after one or two chemotherapy regimens and the white blood cell count at presentation was below 50,000/mL (n=12), while patients requiring more than two induction regimens to attain first CR and with CR2 ou more advanced disease and/or had a higher white blood cell count at presentation were defined as high risk (n=30). Twenty one patients were transplanted in first CR. The median patient age was 24 years (range, 2-56 years), and the median time interval from diagnosis to autologous SCT was 9 months (range 3-87 months). The conditioning regimen for SCT consisted of busulfan (BU) 16 mg/kg and melfalan (MEL) 180 mg/m2 (BUMEL) in 17 (40%) patients and busulfan 16 mg/kg and VP-16 60 mg/kg (BUVP16) in 22 (52%) patients. Three patients received a different conditioning regimen with BCNU 300 mg/m2, VP16 2 g/m2 and melphalan 160 mg/m2 (BEM). Twenty five (60%) patients received bone marrow (BM), 11 (26%) patients received peripheral blood stem cells (PBSC) and 6 patients (14%) received BM plus PBSC. With a median follow-up of 7 years, the 13 year overall survival (OS) and diseasefree survival (DFS) of all patients is 52% and 40%, respectively. In univariate analysis, males had a significantly superior DFS than females (55% vs 22%, p=0.003), and patients younger than 15 years of age had significantly superior OS and DFS than older patients (50% vs 35%, p=0.05; and 50% vs 28%, p=0.03, respectively). Patients with FAB M3 subtype also had a superior OS than the other FAB subtypes (100% vs 44%, p=0.05). There was a strong statistical correlation between risk group and survival. In fact, the patients with standard risk had a superior OS and DFS than those with high risk disease (67% vs 23%, p=0.0004; and 50% vs 27%, p=0.01, respectively). When patients with FAB M3 disease were excluded from the analysis, the group with standard risk continue to have a superior OS and DFS (67% vs 13%, p=0.008; and 50% vs 14%, p=0.02, respectively). We conclude that autologous SCT is an effective treatment in AML with the possibility of long survivorship, particularly in patients with standard risk disease.info:eu-repo/semantics/publishedVersio
Transplante alogénico de células estaminais em doentes com síndrome mielodisplásica: análise de acordo com o Índice de Prognóstico Internacional
© Ordem dos MédicosWe determined the outcome of patients with myelodysplastic syndrome (MDS) and secondary acute myeloid leukemia (sAML) after allogeneic stem cell transplantation according to their international prognostic scoring system (IPSS) risk categories at diagnosis. A total of 11 females and 7 males, with a median age of 45 years, were transplanted. With a median follow-up of 60 months, the 6-year actuarial event-free survival (EFS) for Less Advanced (Low and Intermediate-1 risk IPSS) and Advanced (Intermediate-2 and High risk IPSS) MDS was 71.4% and 43.6%, respectively (p=0.002). We did not observe a difference in EFS depending on cytogenetics at diagnosis (good risk 53.8% Vs intermediate and high risk 53.3%, p=ns), neither on the type of conditioning regimen used (myeloablative 50% Vs reduced intensity 52.2%, p=ns). Our results support that IPSS score at diagnosis may be used to predict EFS in patients with MDS undergoing allogeneic SCT.Neste estudo avaliámos o valor preditivo do índice prognóstico internacional (IPSS) na altura do diagnóstico em doentes com síndrome mielodisplásica (SMD) e leucemia mielóide aguda secundária submetidos a transplante alogénico de células estaminais. Foram transplantados um total de 11 mulheres e sete homens, com uma mediana de idades de 45 anos. Com um seguimento mediano de 60 meses, a sobrevivência livre de eventos aos 6 anos nos doentes com doença menos avançada (IPSS Risco Baixo e Intermédio 1) e com doença avançada (IPSS Intermédio 2 e Alto Risco) foi de 71.4% e 43.6%, respectivamente (p=0.002). Não observámos diferenças significativas na sobrevivência livre de eventos de acordo com a análise citogenética na altura do diagnóstico (risco bom 53,8% VS risco intermédio e alto 53,3%, p=ns) nem com o tipo de regime de condicionamento utilizado (mieloablativo 50% VS intensidade reduzida 52,2%, p=ns). Os nossos resultados demonstram que o IPSS na altura do diagnóstico pode ser utilizado para predizer a sobrevivência livre de eventos em doentes com SMD submetidos a transplante alogénico de células estaminaisinfo:eu-repo/semantics/publishedVersio
DSO Contract Market for Demand Response Using Evolutionary Computation
In this article, a cost optimization problem in local energy markets is analyzed considering fixed-term flexibility contracts between the DSO and aggregators. The DSO procures flexibility while aggregators of different types (e.g., conventional demand response or thermo-load aggregators) offer the service. We solve the proposed model using evolutionary algorithms based on the well-known differential evolution (DE). First, a parameter-tuning analysis is done to assess the impact of the DE parameters on the quality of solutions to the problem. Later, after finding the best set of parameters for the "tuned" DE strategies, we compare their performance with other self-adaptive parameter algorithms, namely the HyDE, HyDE-DF, and vortex search algorithms. Results show that with the identification of the best set of parameters to be used for each strategy, the tuned DE versions lead to better results than the other tested EAs. Overall, the algorithms are able to find near-optimal solutions to the problem and can be considered an alternative solver for more complex instances of the model.This research has received funding from FEDER funds through the Operational Programme for Competitiveness and Internationalization (COMPETE 2020) and National Funds through the FCT Portuguese Foundation for Science and Technology, under Projects PTDC/EEIEEE/28983/2017(CENERGETIC), CEECIND/02814/2017 (Joao Soares grant), and UIDB/000760/2020.info:eu-repo/semantics/publishedVersio
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