176 research outputs found

    Modeling genome-wide replication kinetics reveals a mechanism for regulation of replication timing

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    We developed analytical models of DNA replication that include probabilistic initiation of origins, fork progression, passive replication, and asynchrony.We fit the model to budding yeast genome-wide microarray data probing the replication fraction and found that initiation times correlate with the precision of timing.We extracted intrinsic origin properties, such as potential origin efficiency and firing-time distribution, which cannot be done using phenomenological approaches.We propose that origin timing is controlled by stochastically activated initiators bound to origin sites rather than explicit time-measuring mechanisms

    LOCUS (LOng Covid–Understanding Symptoms, events and use of services in Portugal): A three-component study protocol

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    Approximately 10% of patients experience symptoms of Post COVID-19 Condition (PCC) after a SARS-CoV-2 infection. Akin acute COVID-19, PCC may impact a multitude of organs and systems, such as the cardiovascular, respiratory, musculoskeletal, and neurological systems. The frequency and associated risk factors of PCC are still unclear among both community and hospital settings in individuals with a history of COVID-19. The LOCUS study was designed to clarify the PCC's burden and associated risk factors. LOCUS is a multi-component study that encompasses three complementary building blocks. The "Cardiovascular and respiratory events following COVID-19" component is set to estimate the incidence of cardiovascular and respiratory events after COVID-19 in eight Portuguese hospitals via electronic health records consultation. The "Physical and mental symptoms following COVID-19" component aims to address the community prevalence of self-reported PCC symptoms through a questionnaire-based approach. Finally, the "Treating and living with Post COVID-19 Condition" component will employ semi-structured interviews and focus groups to characterise reported experiences of using or working in healthcare and community services for the treatment of PCC symptoms. This multi-component study represents an innovative approach to exploring the health consequences of PCC. Its results are expected to provide a key contribution to the optimisation of healthcare services design.info:eu-repo/semantics/publishedVersio

    The Portfolio as an Evaluation Tool: an Analysis of its Use in an Undergraduate Nursing Program

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    This qualitative study was carried out between April and August 2007. It analyzed the use of portfolios in the academic community. A total of nine full-time professors and 119 students enrolled in their third semester were interviewed through a semi-structured interview. Content analysis was used to analyze data. Learning evaluations are seen as a verification of knowledge and efficacy of pedagogical method, and also as an incentive to study. Evaluations are procedural, that is, evaluation is continuous, or one-time, e.g. semester end tests. The portfolio is defined as a gradual and continuous evaluation tool. The faculty members and students need to accept the use of portfolios and evaluate the possibilities of this resource. This study is a first attempt to appraise the evaluation process of an undergraduate program, and the use of portfolios and other strategies needs to be consolidated in order to improve the educational process in undergraduate nursing programs.Se trata de un estudio cualitativo, realizado en el período de abril a agosto de 2007. El objetivo fue analizar la utilización del portafolio por la comunidad académica. Se entrevistó a través de un guión a nueve docentes efectivos y 119 discentes matriculados a partir del tercer período. En el análisis de datos se utilizó el análisis de contenido. La evaluación del aprendizaje es considerada como verificación del conocimiento, como eficacia del método pedagógico e incentivo al estudio. Con relación al tipo de evaluación son procesuales y puntuales. El portafolio es definido como un instrumento de evaluación gradual y continuo. Es necesario que el cuerpo docente y discente acepte experimentar la utilización del portafolio y así evaluar las posibilidades de este recurso. Representa una primera aproximación al proceso de evaluación en la graduación y de esa forma el portafolio y otras estrategias necesitan ser consolidadas de forma a mejorar el proceso de formación en la graduación de enfermería.Este é um estudo qualitativo, realizado no período de abril a agosto de 2007. O objetivo foi analisar a utilização do portfólio pela comunidade acadêmica. Entrevistaram-se, através de um roteiro, nove docentes efetivos e 119 discentes matriculados a partir do terceiro período. Na análise de dados utilizou-se da análise de conteúdo. A avaliação da aprendizagem é considerada como verificação do conhecimento, como eficácia do método pedagógico e incentivo ao estudo. Com relação aos tipos de avaliação são eles processuais e pontuais. O portfólio é definido como instrumento de avaliação gradual e contínuo. É necessário que o corpo docente e discente aceite experimentar a utilização do portfólio e assim avaliar as possibilidades desse recurso. Representa a primeira aproximação ao processo de avaliação na graduação e, dessa forma, o portfólio e outras estratégias precisam ser consolidadas de forma a melhorar o processo de formação na graduação de enfermagem

    Characterization of complex networks: A survey of measurements

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    Each complex network (or class of networks) presents specific topological features which characterize its connectivity and highly influence the dynamics of processes executed on the network. The analysis, discrimination, and synthesis of complex networks therefore rely on the use of measurements capable of expressing the most relevant topological features. This article presents a survey of such measurements. It includes general considerations about complex network characterization, a brief review of the principal models, and the presentation of the main existing measurements. Important related issues covered in this work comprise the representation of the evolution of complex networks in terms of trajectories in several measurement spaces, the analysis of the correlations between some of the most traditional measurements, perturbation analysis, as well as the use of multivariate statistics for feature selection and network classification. Depending on the network and the analysis task one has in mind, a specific set of features may be chosen. It is hoped that the present survey will help the proper application and interpretation of measurements.Comment: A working manuscript with 78 pages, 32 figures. Suggestions of measurements for inclusion are welcomed by the author

    Functional imaging of cognition in an old-old population: A case for portable functional near-infrared spectroscopy

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    In this study, functional near-infrared spectroscopy (fNIRS) was used to record brain activa- tion during cognitive testing in older individuals (88±6yo; N = 19) living in residential care communities. This population, which is often associated with loss of personal independence due to physical or cognitive decline associated with aging, is also often under-represented in neuroscience research because of a limited means to participate in studies which often take place in large urban or university centers. In this study, we demonstrate the feasibility and initial results using a portable 8-source by 4-detector fNIRS system to measure brain activity from participants within residential care community centers. Using fNIRS, brain sig- nals were recorded during a series of computerized cognitive tests, including a Symbol Digit Coding test (SDC), Stroop Test (ST), and Shifting Attention Test (SAT). The SDC and SAT elicited greater activity in the left middle frontal region of interest. Three components of the ST produced increases in the right middle frontal and superior frontal, and left superior frontal regions. An association between advanced age and increased activation in the right middle frontal region was observed during the incongruent ST. Although none of the partici- pants had clinical dementia based on the short portable mental status questionnaire, the group performance was slightly below age-normed values on these cognitive tests. These results demonstrate the capability for obtaining functional neuroimaging measures in resi- dential settings, which ultimately may aid in prognosis and care related to dementia in older adults
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