15 research outputs found
Brain activity during the memorization of visual scenes from TV commercials: an application of high resolution EEG and steady state somatosensory evoked potentials technologies
No full textResting state cortical EEG rhythms in Alzheimer's disease: toward EEG markers for clinical applications: a review
No full textThe human brain contains an intricate network of about 100 billion neurons. Aging of the brain is characterized by a combination of synaptic pruning, loss of cortico-cortical connections, and neuronal apoptosis that provoke an age-dependent decline of cognitive functions. Neural/synaptic redundancy and plastic remodeling of brain networking, also secondary to mental and physical training, promote maintenance of brain activity and cognitive status in healthy elderly subjects for everyday life. However, age is the main risk factor for neurodegenerative disorders such as Alzheimer's disease (AD) that impact on cognition. Growing evidence supports the idea that AD targets specific and functionally connected neuronal networks and that oscillatory electromagnetic brain activity might be a hallmark of the disease. In this line, digital electroencephalography (EEG) allows noninvasive analysis of cortical neuronal synchronization, as revealed by resting state brain rhythms. This review provides an overview of the studies on resting state eyes-closed EEG rhythms recorded in amnesic mild cognitive impairment (MCI) and AD subjects. Several studies support the idea that spectral markers of these EEG rhythms, such as power density, spectral coherence, and other quantitative features, differ among normal elderly, MCI, and AD subjects, at least at group level. Regarding the classification of these subjects at individual level, the most previous studies showed a moderate accuracy (70-80%) in the classification of EEG markers relative to normal and AD subjects. In conclusion, resting state EEG makers are promising for large-scale, low-cost, fully noninvasive screening of elderly subjects at risk of AD
Heterogeneous and tissue-specific regulation of effector T cell responses by IFN-gamma during Plasmodium berghei ANKA infection.
No full textIFN-γ and T cells are both required for the development of experimental cerebral malaria during Plasmodium berghei ANKA infection. Surprisingly, however, the role of IFN-γ in shaping the effector CD4(+) and CD8(+) T cell response during this infection has not been examined in detail. To address this, we have compared the effector T cell responses in wild-type and IFN-γ(-/-) mice during P. berghei ANKA infection. The expansion of splenic CD4(+) and CD8(+) T cells during P. berghei ANKA infection was unaffected by the absence of IFN-γ, but the contraction phase of the T cell response was significantly attenuated. Splenic T cell activation and effector function were essentially normal in IFN-γ(-/-) mice; however, the migration to, and accumulation of, effector CD4(+) and CD8(+) T cells in the lung, liver, and brain was altered in IFN-γ(-/-) mice. Interestingly, activation and accumulation of T cells in various nonlymphoid organs was differently affected by lack of IFN-γ, suggesting that IFN-γ influences T cell effector function to varying levels in different anatomical locations. Importantly, control of splenic T cell numbers during P. berghei ANKA infection depended on active IFN-γ-dependent environmental signals--leading to T cell apoptosis--rather than upon intrinsic alterations in T cell programming. To our knowledge, this is the first study to fully investigate the role of IFN-γ in modulating T cell function during P. berghei ANKA infection and reveals that IFN-γ is required for efficient contraction of the pool of activated T cells
Energy-efficient cooperative single-carrier frequency-division multiple-access
No full textA variety of cooperative relaying schemes are designed for the single-carrier frequency-division multiple-access (SC-FDMA) uplink, when communicating over broadband wireless channels. Our goal is to reduce the battery power dissipated both by transmission and signal processing, so that the overall energy-efficiency may be increased. We assume that there are a number of inactive mobile terminals acting as potential relays, which have either fixed or time-variant positions in a cell. Our investigations are focused on the optimum exploitation of all the resources, when considering relay selection, power allocation and channel-quality-aided adaptive subband allocation. We exploit the benefits of combining the path-loss reduction and diversity gains arising from both fixed and opportunistic relaying, user cooperation and from all the propagation paths, as well as from multiple antennas. Novel frequency-domain equalisation and diversity combining approaches are also conceived.Specifically, we firstly conceive two single-relay assisted topologies for the sake of exploiting the achievable cooperative diversity, namely the single-dedicated-relaying (SDR), where each relay is dedicated to a single user, and the single-shared-relaying (SSR), when a single relay assists multiple users. In order to eliminate both the multi-user interference and for the sake of mitigating the noise-amplification imposed by amplify-and-forward (AF) relaying, we propose an efficient subband-based AF scheme, which is benchmarked against the conventional AF regime in the context of both the SDR and SSR topologies. Furthermore, by assuming that the channel state information (CSI) is available at the base station (BS)’s receiver, a joint frequency-domain equalisation and diversity-combining scheme is proposed for the sake of increasing the achievable cooperative diversity gain. In this case, when considering the different number of available relays that are geographically dispersed across a large-scale environment subject to both path-loss and shadowing, we propose three different dynamic relay selection schemes, namely single-user relay selection (SU-RS), multi-user relay selection (MU-RS), and multiple-access relay selection (MA-RS), combined with source/relay vi power allocation in the context of opportunistic cooperation (OC) for the sake of increasing the multi-user system’s throughput. By contrast, when the source-to-destination (S-D) direct links are of low quality and hence are deemed to be unavailable, we exploit the relays which are roaming within each other’s vicinity in geographically localised manner in a cluster. Therefore, by assuming that these cooperating relays are capable of exchanging their channel quality information (CQI), we propose two first-hop-quality-aware (FHQA) joint dynamic resource allocation (DRA) schemes for opportunistic relaying (OR) based SCFDMA uplink, which beneficially combines channel-quality-aware subband allocation with efficient relay selection. The FHQA joint DRA schemes optimise the multi-user multi-relay networks relying on whether it is the source-to-relay (S-R) or the relay-to-destination (R-D) link, which dominates the attainable performance, when the BS’s receiver employs either single or multiple antennas. Additionally, the benefits of OR are quantified in the context of interleaver-aided decode-and-forward (DF) relaying for transmission over correlated fading channels. Therefore, the length of the interleavers combined with channel coding may be shortened. As a result, we benefit from a reduced interleaving delay and/or from a total transmit power reduction. In comparison to the benchmark schemes considered in the literature, the reliability and energy-efficiency of our proposed systems are significantly improved
El aprendizaje-servicio: una estrategia para la formación de competencias en sostenibilidad
No full textThe article presents the teaching strategy of Service-Learning as a tool to develop competencies related to the challenge of sustainability, as it is established from the guidelines of the CRUE and in other local and global institutional levels. It analyzes the teaching experience of the author, who has utilized the methodology of Service-Learning in university education in order to train future educators in the achievement of key competences for sustainability: critical and systemic thinking, collaborative decision-making, and taking responsibility for present and future generations (UNESCO, 2014). The aim of the article is to situate Service-Learning as a catalyst element to transform oneself and a strategy in the service of education for sustainable development. It assumes United Nations guidelines claiming for the need of empowering educators through a learning that achieves the own transformation as a platform from which to lead ourselves to more sustainable ways of life for people and the planet we inhabit. It concludes confirming the capacity of Service-Learning to provoke academic contends facilitate the formation in competences for transforming action in the searching of the construction of more sustainable realities.How to reference this articleVázquez Verdera, V. (2015). El aprendizaje-servicio: una estrategia para la formación de competencias en sostenibilidad. Foro de Educación, 13(19), 193-212. doi: http://dx.doi.org/10.14516/fde.2015.013.019.009El artículo presenta la estrategia docente del Aprendizaje-Servicio como herramienta para desarrollar competencias vinculadas al reto de la sostenibilidad, tal y como establecen las directrices de la Conferencia de Rectores de las Universidades españolas (CRUE) y otras instancias institucionales a nivel local y global. Se analiza la experiencia docente de la autora, que ha utilizado la metodología del aprendizaje-servicio en la enseñanza universitaria para la formación de futuros y futuras profesionales de la educación en el logro de competencias clave exigidas por el desarrollo sostenible: el análisis crítico, la reflexión sistémica, la toma de decisión colaborativa, y el sentido de responsabilidad hacia generaciones presentes y futuras (UNESCO, 2014). Se pretende situar el aprendizaje-servicio como elemento catalizador de la propia transformación y como estrategia al servicio de la educación para el desarrollo sostenible. Se asumen los planteamientos de las Naciones Unidas que reclaman la necesidad de empoderar a los y las profesionales de la educación a través de un aprendizaje que consiga la propia transformación, como plataforma desde la que caminar hacia formas de vida más sostenibles para las personas y el planeta que habitamos (UNECE, 2013). Se concluye confirmando la capacidad del aprendizaje-servicio para provocar que los contenidos académicos faciliten la formación de competencias para la acción transformadora que busca la construcción de realidades más sostenibles.Cómo referenciar este artículoVázquez Verdera, V. (2015). El aprendizaje-servicio: una estrategia para la formación de competencias en sostenibilidad. Foro de Educación, 13(19), 193-212. doi: http://dx.doi.org/10.14516/fde.2015.013.019.00
Tutoria em um curso de educação a distância: contribuições à formação stricto sensu em enfermagem
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Programa de Pós-Graduação em Enfermagem, Florianópolis, 2014.A educação a distância é uma modalidade tecnológica e inovadora, a qual vem sendo intensamente utilizada nos cursos de atualização, graduação e pós-graduação, porém ainda são poucos os estudos sobre essa realidade na Enfermagem brasileira. Esse estudo teve como objetivo compreender como a atividade de tutoria de um curso em Educação a Distância contribui à formação profissional de enfermeiros estudantes de pós-graduação stricto sensu. O referencial teórico utilizado foi o autor Paulo Freire. Pesquisa de abordagem qualitativa, caracterizada como um estudo de caso único. A coleta de dados ocorreu em dezembro de 2013, por meio de entrevistas semiestruturadas, realizadas com 17 (dezessete) enfermeiros, que eram tutores de um curso de especialização a distância e alunos de pós-graduação stricto sensu de uma universidade do Sul do Brasil. Após a análise dos dados emergiram três categorias, sendo estas: 1)A prática tutorial, que engloba três subcategorias: Papel do tutor e as atividades desenvolvidas, Abordagens e metodologias utilizadas pelo tutor, Avaliação dos estudantes realizada pelo tutor; 2) Conhecimentos e habilidades necessários ao tutor; e a categoria 3) Contribuições da prática tutorial para a formação stricto sensu, que engloba quatro subcategorias: Reflexão crítica sobre a prática como tutor, Exercício da tutoria no desenvolvimento do Pós-graduando, Tutoria como auxílio para a construção docente, A prática dialógica tutor-aluno no ambiente virtual de aprendizagem. São poucos os estudos, que trazem a realidade da educação a distância na área da enfermagem, sendo necessárias pesquisas, que possam aprimorar metodologias pedagógicas específicas para o processo de ensino e aprendizagem em cursos para formação e qualificação nessa modalidade. Foi possível observar que as atividades tutoriais trouxeram contribuições para o processo de formação de mestres e doutores. Seria interessante que os programas de pós-graduação stricto sensu em enfermagem oferecessem instrumentalização sobre as especificidades desse processo de ensino e aprendizagem aos seus estudantes.Abstract : Distance education is a technological and innovative modality, which has been extensively used in refresher courses, undergraduate and graduate, but there are few studies about the reality of Brazilian Nursing. This study aimed to understand how the activity of tutoring a course in Distance Education contributes to the professional development of student nurses graduate stricto sensu. The theoretical framework used was the author Paulo Freire. Qualitative research approach characterized as a single case study. Data collection occurred in December 2013, through semi-structured interviews with 17 nurses, which are tutors of a specialization course and distance students graduate of stricto sensu in university in southern Brazil. After analyzing the data emerged three categories, which are: 1) A practical tutorial, which includes three subcategories: The role of the tutor and developed activities, Approaches and methodologies used by the tutor, Student Assessment conducted by the tutor; 2) knowledge and skills needed to tutor; and category 3) Contributions of practical tutorial for training stricto sensu, which includes four subcategories: Critical reflection on practice as a tutor, Exercise tutoring in the development of post -graduate student, tutoring aid for teaching construction, dialogic practice tutor -student in the virtual learning environment. Few studies that bring the reality of distance education in nursing, being necessary research that can improve specific teaching methods in the process of teaching and learning in courses for training and qualification in this modality. It was observed that the tutorial activities brought contributions to the process of training masters and doctors. It would be interesting programs for post- graduate studies in nursing offered instrumentation on the specifics of the teaching and learning process for their students
Enlaces: memória e subjetividades no acervo Jorge Amado
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão, Programa de Pós-Graduação em Literatura, Florianópolis, 2015.O objetivo central da minha dissertação é apresentar o resultado das relações afetivas constituídas e apreendidas no Acervo Jorge Amado (NuLIME). A minha subjetividade foi ao encontro da memória material das cartas destinadas ou remetidas por dois comunistas: Juan e Joaquim. A leitura delas me permitiu ressignificar a questão da autoria e da literatura epistolar. O trabalho, em parte, foi apresentado como cartas. A escrita, situada no limite entre ficcional e factual, faz referências ao contexto político e social do Brasil no período da ditadura de Vargas. O trabalho está inserido no contexto específico da memória e da narrativa dos comunistas e perseguidos políticos que viveram esta fase da vida intelectual, social, política e literária brasileira.Abstract : My dissertation´s main objective is to present the result of the affective relations constituted and apprehended from Jorge Amado´s collection (NuLIME). My subjectivity is connected to the material memory of the letters destined or posted by two communists: Juan and Joaquim. Reading them has enabled me to reframe the questions of authorship and epistolary literature. The work was partially presented as letters. The writing, classified in between fictional and factual, refers to the social and political context and to the narrative from communists and political persecuted who lived this period of Brazilian intellectual, social, political and literary life
Viajantes ex-cêntricas nas histórias de Ana Miranda
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão. Programa de Pós-Graduação em Literatura.No conjunto das narrativas ficcionais da escritora brasileira Ana Miranda, a temática da viagem # considerada uma das mais férteis da literatura ocidental de todos os tempos # ocupa um espaço de centralidade, podendo até mesmo ser vista como o mais importante eixo de estruturação de suas obras. O estudo realizado pela presente tese tem por objetivo analisar o tratamento dado ao tema da viagem nos romances Desmundo, O retrato do rei, Dias & Dias e Amrik, evidenciando que por intermédio das narradora-viajantes # Oribela, Mariana, Feliciana e Amina # a autora promove um diálogo entre diferentes culturas, gêneros, etnias e gerações, ao mesmo tempo em que estabelece um profícuo diálogo com o passado em sua invariante problematização concernente aos limites e cruzamentos entre o discurso ficcional e os discursos narrativos extraliterários que o cercam, sobretudo o histórico e o biográfico. In the whole of Brazilian writer Ana Miranda#s fictional narrative, the travel thematic # considered one of the most fertile themes of the western literature of all times # occupies a central space, and can even been seen as the most important structuring axis of Miranda#s works. The aim of the present thesis is to analyze the treatment given to the travel subject in the novels Desmundo, O retrato do rei, Dias & Dias and Amrik, emphasizing that, through the traveling narrators, Oribela, Mariana, Feliciana and Amina, the author promotes a connection between different cultures, genders, ethnics and generations, at the same time that establishes a profitable dialogue with the past in her invariant problematization concerning the limits and crossings between the fictional and the extra-literary narrative discourses that surrounds it, mainly the historical and the biographic ones
Ki-67 is a PP1-interacting protein that organises the mitotic chromosome periphery
No full textCopyright @ 2014 Booth et al. This article is distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use and redistribution provided that the original author and source are credited.When the nucleolus disassembles during open mitosis, many nucleolar proteins and RNAs associate with chromosomes, establishing a perichromosomal compartment coating the chromosome periphery. At present nothing is known about the function of this poorly characterised compartment. In this study, we report that the nucleolar protein Ki-67 is required for the assembly of the perichromosomal compartment in human cells. Ki-67 is a cell-cycle regulated protein phosphatase 1-binding protein that is involved in phospho-regulation of the nucleolar protein B23/nucleophosmin. Following siRNA depletion of Ki-67, NIFK, B23, nucleolin, and four novel chromosome periphery proteins all fail to associate with the periphery of human chromosomes. Correlative light and electron microscopy (CLEM) images suggest a near-complete loss of the entire perichromosomal compartment. Mitotic chromosome condensation and intrinsic structure appear normal in the absence of the perichromosomal compartment but significant differences in nucleolar reassembly and nuclear organisation are observed in post-mitotic cells
Strahlung von Sendeanlagen und Gesundheit : Bewertung von wissenschaftlichen Studien im Niedrigdosisbereich (Stand: Dezember 2012)
No full textThis report updates the assessment of the health effects of high-frequency radiation based on newly published studies on human beings in the period from October 2006 to December 2012. It takes account of experimental field studies, epidemiological studies of population groups in their everyday environment and experimental studies with short-term exposure under controlled conditions in the laboratory, in which the influence of high-frequency radiation from fixed facilities such as broadcasting transmitters and mobile telephone base stations was studied. In the past six years, approximately 50 studies on this topic were published. Generally speaking, exposure to high-frequency radiation from fixed transmitters is pleasingly low, and at this exposure level no harmful effects on health have been scientifically established to date. In view of this, there is no call for a modification of the ambient limit values specified in the Ordinance relating to Protection from Non-Ionising Radiation (ONIR). With respect to the nonthermal effects of high-frequency radiation, there are still many gaps in scientific knowledge. In particular, there are almost no methodologically sound long-term observations. It is therefore not possible to make a reliable assessment of any potential longterm risks at this time, and consequently caution is called for, especially with regard to long-term exposure to high-frequency radiation
