164 research outputs found
Extensions in Joint Modeling of Survival and Longitudinal Outcomes
__abstract__
In many medical studies both longitudinal and event history data are collected
for each patient. A well-known and broadly studied example is found
in AIDS research, where CD4 cell counts taken at different time points are
related to the time-to-death. Often such outcomes are separately analyzed.
However, in two particular settings a joint modeling approach is required.
First, when focus is on the event times and we wish to study the association
between the longitudinal responses and the risk for an event, where we
need to take into account the fact that the longitudinal response is also an
outcome generated by the same subject. Second, when focus is on the longitudinal
outcome and events cause dropout. Under specific circumstances
the dropout process needs to be accounted in the analysis in order to obtain
valid inferences for the longitudinal outcome
Visual Tools for Eliciting Connections and Cohesiveness in Mixed Methods Research
In this commentary, we offer a set of visual tools that can assist education researchers, especially those in the field of mathematics, in developing cohesiveness from a mixed methods perspective, commencing at a study’s research questions and literature review, through its data collection and analysis, and finally to its results. This expounds upon the ideas and methodological insights relating to research connections and structure presented by other scholars (e.g., Creswell, 2009; Heid & Blume, 2011; Mertens, 2010; Thanheiser, Ellis, & Herbel-Eisenmann, 2012). As faculty who work with graduate students in education, we have found that these visual tools help students elicit and maintain salient connections throughout the research process
Coherence and enrichment across the middle and secondary levels: Four mathematically authentic learning experiences
This article discusses four mathematically rich settings with origins in the elementary, middle, and secondary school curricula. Depending on the questions asked and the connections made within each setting, the problem spaces allow the instructor to import tools leading to sophisticated extensions appropriate for college-level study. These topics include the Heaviside function, randomness, symmetry, modular arithmetic, the generalized Pythagorean Theorem, and the theory of groups. Given the potentially extensive ground covered by these settings, they serve to reward those students who are inherently curious while highlighting the coherence in the curriculum as one progresses through the grades. The mathematical experiences invite disciplinary and interdisciplinary connections and encourage discourse and productive struggle
Dynamic Predictions with Time-Dependent Covariates in Survival Analysis using Joint Modeling and Landmarking
A key question in clinical practice is accurate prediction of patient
prognosis. To this end, nowadays, physicians have at their disposal a variety
of tests and biomarkers to aid them in optimizing medical care. These tests are
often performed on a regular basis in order to closely follow the progression
of the disease. In this setting it is of medical interest to optimally utilize
the recorded information and provide medically-relevant summary measures, such
as survival probabilities, that will aid in decision making. In this work we
present and compare two statistical techniques that provide dynamically-updated
estimates of survival probabilities, namely landmark analysis and joint models
for longitudinal and time-to-event data. Special attention is given to the
functional form linking the longitudinal and event time processes, and to
measures of discrimination and calibration in the context of dynamic
prediction.Comment: 34 pages, 4 figures. arXiv admin note: substantial text overlap with
arXiv:1303.279
Bdnf impact on biological markers of depression—role of physical exercise and training
Depression is the most common and devastating psychiatric disorder in the world. Its symptoms, especially during the pandemic, are observed in all age groups. Exercise training (ET) is well known as a non-pharmacological strategy to alleviate clinical depression. The brain-derived neurotrophic factor (BDNF) is one of the biological factors whose expression and secretion are intensified in response to ET. BDNF is also secreted by contracted skeletal muscle that likely exerts para-, auto-and endocrine effects, supporting the crosstalk between skeletal muscle and other distant organs/tissues, such as the nervous system. This finding suggests that they communicate and work together to induce improvements on mood, cognition, and learning processes as BDNF is the main player in the neurogenesis, growth, and survival of neurons. Therefore, BDNF has been recognized as a therapeutic factor in clinical depression, especially in response to ET. The underlying mechanisms through which ET impacts depression are varied. The aim of this review was to provide information of the biological markers of depression such as monoamines, tryptophan, endocannabinoids, markers of inflammatory processes (oxidative stress and cytokines) stress and sex hormones and their relationship to BDNF. In addition, we reviewed the effects of ET on BNDF expression and how it impacts depression as well as the potential mechanisms mediating this process, providing a better understanding of underlying ET-related mechanisms in depression.Internal grant of University School of Physical Education. Project No. 503 62/05 Effectiveness of various therapeutic forms and their influence on nervous, muscular and vascular plasticity in patients after ischemic stroke”
Leczenie neurochirurgiczne i napromienianie przerzutĂłw do mĂłzgu u chorych na raka piersi – analiza przeĹĽyć i czynnikĂłw prognostycznych
The effects of exercise order on the psychophysiological responses, physical and technical performances of young soccer players: Combined small-sided games and high-intensity interval training
This study aimed to compare the order effects of combined small-sided games (SSGs) and high-intensity interval training (HIIT) on the psychophysiological responses and physical and technical performances of young soccer players. Twenty-four soccer players (aged 14.63 ± 0.71 years) were randomly divided into SSGs + HIIT (n = 12) and HIIT + SSGs (n = 12) for 6 weeks. The SSGs consisted of two 4–16 min rounds of 2, 3, and four-a-side games with 2 min of passive resting, whereas the HIIT consisted of 6–10 min of high-intensity runs at varying intensities (from 90 to 100%). Pre-test and post-test elements included a 5–30 m sprint test, countermovement jump test, zigzag agility test with the ball and without the ball, repeated sprint ability test, speed dribbling ability test, three-corner run test, and Yo-Yo Intermittent Recovery Test level 1. Both combined training interventions produced similar improvements in physical performance and technical responses (p ? 0.05, d values ranging from 0.40 to 1.10). However, the combined HIIT + SSGs training produced meaningfully lower perceived exertion (p = 0.00, d = 2.98) and greater physical enjoyment (p = 0.00, d = 4.28) compared with the SSGs + HIIT intervention. Furthermore, the SSGs + HIIT group showed a higher training load than those from the HIIT + SSGs group for all weeks (p ? 0.05, d values ranging from 1.36 to 2.05). The present study’s results might be used by coaches and practitioners to design training programmes for youth soccer players. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.UIDB/EEA/50008/2020Funding: Filipe Manuel Clemente: This work is funded by Fundação para a Ciência e Tecnolo-gia/Ministério da Ciência, Tecnologia e Ensino Superior through national funds and when applicable co-funded EU funds under the project UIDB/EEA/50008/2020
Stronger relation between impairment and manual capacity in the non-dominant hand than the dominant hand in congenital hand differences; Implications for surgical and therapeutic interventions
Objectives To evaluate manual activity capacity (i.e. activity capacity to perform hand activities) and its relation with body functions of the hand and forearm in children with congenital hand differences (CHD) Methods We assessed 10-14 year-old children with CHD (N = 106) using a functional handgrips test. Measurements of body functions included joint mobility and muscle strength. Patient characteristics were hand dominance and severity. Results We found a stronger relation between body functions and manual activity capacity in non-dominant hands than dominant hands. Dominant hands scored significantly higher on manual activity capacity than nondominant hands that were similarly impaired at body functions level. Severity of the CHD and body functions had only small effects on manual activity capacity. Conclusion The relation between body functions and manual activity capacity is stronger in non-dominant hands than dominant hands, indicating that improvement in body functions lead to larger changes in manual activity capacity in the non-dominant hand. This may suggest that in bilaterally-affected children surgery should be done at the non-dominant hand first since this hand would benefit most from surgery-induced body functions improvement
Multiple aspects of atp-dependent nucleosome translocation by rsc and mi-2 are directed by the underlying dna sequence
Biological and Soft Matter Physic
LINT, a Novel dL(3)mbt-Containing Complex, Represses Malignant Brain Tumour Signature Genes
Mutations in the l(3)mbt tumour suppressor result in overproliferation of Drosophila larval brains. Recently, the derepression of different gene classes in l(3)mbt mutants was shown to be causal for transformation. However, the molecular mechanisms of dL(3)mbt-mediated gene repression are not understood. Here, we identify LINT, the major dL(3)mbt complex of Drosophila. LINT has three core subunits—dL(3)mbt, dCoREST, and dLint-1—and is expressed in cell lines, embryos, and larval brain. Using genome-wide ChIP–Seq analysis, we show that dLint-1 binds close to the TSS of tumour-relevant target genes. Depletion of the LINT core subunits results in derepression of these genes. By contrast, histone deacetylase, histone methylase, and histone demethylase activities are not required to maintain repression. Our results support a direct role of LINT in the repression of brain tumour-relevant target genes by restricting promoter access
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