403 research outputs found
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Trends in Medical Aid in Dying in Oregon and Washington.
ImportanceThe combined 28 years of data of medical aid in dying (MAID) between Oregon (OR) and Washington (WA) are the most comprehensive in North America. No reports to date have compared MAID use in different US states.ObjectiveTo evaluate and compare patterns of MAID use between the states with the longest-running US death with dignity programs.Design, setting, and participantsA retrospective observational cohort study of OR and WA patients with terminal illness who received prescriptions as part of their states' legislation allowing MAID. All published annual reports, from 1998 to 2017 in OR and from 2009 to 2017 in WA, were reviewed. A total of 3368 prescriptions were included.Main outcomes and measuresNumber of deaths from self-administration of lethal medication vs number of prescriptions written.ResultsA combined 3368 prescriptions were written in OR and WA, with 2558 patient deaths from lethal ingestion (76.0%). Of the 2558 patients, most were male (1311 [51.3%]), older than 65 years (1851 [72.4%]), and non-Hispanic white (2426 [94.8%]). The most common underlying illnesses were cancer (1955 [76.4%]), neurologic illness (261 [10.2%]), lung disease (144 [5.6%]), and heart disease (117 [4.6%]). Loss of autonomy (2235 [87.4%]), impaired quality of life (2203 [86.1%]), and loss of dignity (1755 [68.6%]) were the most common reasons for pursuing MAID. Time between drug intake to coma ranged from 1 to 660 minutes and time from drug intake to death ranged from 1 to 6240 minutes. In the 1557 patients for whom rates of complications were reported, 1494 (96.0%) did not experience a complication (592 of 626 [94.6%] in OR and 902 of 931 [96.8%] in WA). Eight patients (<0.5%) regained consciousness after drug ingestion in OR. Annual rates per year for percentage of patients who received a prescription ingesting the prescribed medication ranged from 48% to 87%, with no significant time trend in OR (adjusted odds ratio per year, 1.01; 95% CI, 0.99-1.02; P = .59) but with an increase over time in WA (adjusted odds ratio per year, 1.13; 95% CI, 1.08-1.19; P < .001). In both OR and WA there were increases in the number of patient deaths due to MAID per 1000 deaths over time.Conclusions and relevanceIn this study, MAID results in Oregon and Washington were similar, although MAID use measured as a percentage of patients prescribed lethal medications and then self-administering them increased only in WA. Most patients who acquired lethal prescriptions had cancer or terminal illnesses that are difficult to palliate and lead to loss of autonomy, dignity, and quality of life
Observability and nonlinear filtering
This paper develops a connection between the asymptotic stability of
nonlinear filters and a notion of observability. We consider a general class of
hidden Markov models in continuous time with compact signal state space, and
call such a model observable if no two initial measures of the signal process
give rise to the same law of the observation process. We demonstrate that
observability implies stability of the filter, i.e., the filtered estimates
become insensitive to the initial measure at large times. For the special case
where the signal is a finite-state Markov process and the observations are of
the white noise type, a complete (necessary and sufficient) characterization of
filter stability is obtained in terms of a slightly weaker detectability
condition. In addition to observability, the role of controllability in filter
stability is explored. Finally, the results are partially extended to
non-compact signal state spaces
IL-4-secreting CD4+ T cells are crucial to the development of CD8+ T-cell responses against malaria liver stages.
CD4+ T cells are crucial to the development of CD8+ T cell responses against hepatocytes infected with malaria parasites. In the absence of CD4+ T cells, CD8+ T cells initiate a seemingly normal differentiation and proliferation during the first few days after immunization. However, this response fails to develop further and is reduced by more than 90%, compared to that observed in the presence of CD4+ T cells. We report here that interleukin-4 (IL-4) secreted by CD4+ T cells is essential to the full development of this CD8+ T cell response. This is the first demonstration that IL-4 is a mediator of CD4/CD8 cross-talk leading to the development of immunity against an infectious pathogen
Solving linear and quadratic random matrix differential equations: A mean square approach
[EN] In this paper linear and Riccati random matrix differential equations are solved taking advantage of the so called L-p-random calculus. Uncertainty is assumed in coefficients and initial conditions. Existence of the solution in the L-p-random sense as well as its construction are addressed. Numerical examples illustrate the computation of the expectation and variance functions of the solution stochastic process. (C) 2016 Elsevier Inc. All rights reserved.This work has been partially supported by the Spanish Ministerio de Economia y Competitividad grant MTM2013-41765-P and by the European Union in the FP7-PEOPLE-2012-ITN Program under Grant Agreement no. 304617 (FP7 Marie Curie Action, Project Multi-ITN STRIKE-Novel Methods in Computational Finance).Casabán Bartual, MC.; Cortés López, JC.; Jódar Sánchez, LA. (2016). Solving linear and quadratic random matrix differential equations: A mean square approach. Applied Mathematical Modelling. 40(21-22):9362-9377. https://doi.org/10.1016/j.apm.2016.06.017S936293774021-2
Nervous end-structures in the human neurohypophysis
Different types of nervous terminations were described in the human neurohypophysis. The fibers of the hypothalamo-hypophysial tract terminate in the ventricular wall, on blood vessels and around pituicytes; they form terminal networks and end-glomeruli. Verschiedene Typen von Nervenendungen werden in der Neurohypophyse beschrieben. Die Fasern des Tractus hypothalamo-hypophyseus endigen in der Wand des Ventrikels, an Blutgefäen und um Pituicyten. Sie bilden ein terminales Netzwerk und Endglomeruli. Les différents types des terminaisons nerveuses sont décrits dans la neurohypophyse humaine. Les fibres du tractus hypothalamo-hypophysaire se terminent dans la paroi ventriculaire, près de vaisseaux sanguins et dans les environs de pituicites. Elles forment des réseaux terminaux et des glomerules terminaux.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41655/1/702_2005_Article_BF01227771.pd
Mapping Differentiation under Mixed Culture Conditions Reveals a Tunable Continuum of T Cell Fates
Cell differentiation is typically directed by external signals that drive opposing regulatory pathways. Studying differentiation under polarizing conditions, with only one input signal provided, is limited in its ability to resolve the logic of interactions between opposing pathways. Dissection of this logic can be facilitated by mapping the system's response to mixtures of input signals, which are expected to occur in vivo, where cells are simultaneously exposed to various signals with potentially opposing effects. Here, we systematically map the response of naïve T cells to mixtures of signals driving differentiation into the Th1 and Th2 lineages. We characterize cell state at the single cell level by measuring levels of the two lineage-specific transcription factors (T-bet and GATA3) and two lineage characteristic cytokines (IFN-γ and IL-4) that are driven by these transcription regulators. We find a continuum of mixed phenotypes in which individual cells co-express the two lineage-specific master regulators at levels that gradually depend on levels of the two input signals. Using mathematical modeling we show that such tunable mixed phenotype arises if autoregulatory positive feedback loops in the gene network regulating this process are gradual and dominant over cross-pathway inhibition. We also find that expression of the lineage-specific cytokines follows two independent stochastic processes that are biased by expression levels of the master regulators. Thus, cytokine expression is highly heterogeneous under mixed conditions, with subpopulations of cells expressing only IFN-γ, only IL-4, both cytokines, or neither. The fraction of cells in each of these subpopulations changes gradually with input conditions, reproducing the continuous internal state at the cell population level. These results suggest a differentiation scheme in which cells reflect uncertainty through a continuously tuneable mixed phenotype combined with a biased stochastic decision rather than a binary phenotype with a deterministic decision
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The use of the Kalman filter in the automated segmentation of EIT lung images
In this paper, we present a new pipeline for the fast and accurate segmentation of impedance images of the lungs using electrical impedance tomography (EIT). EIT is an emerging, promising, non-invasive imaging modality that produces real-time, low spatial but high temporal resolution images of impedance inside a body. Recovering impedance itself constitutes a nonlinear ill-posed inverse problem, therefore the problem is usually linearized, which produces impedance-change images, rather than static impedance ones. Such images are highly blurry and fuzzy along object boundaries. We provide a mathematical reasoning behind the high suitability of the Kalman filter when it comes to segmenting and tracking conductivity changes in EIT lung images. Next, we use a two-fold approach to tackle the segmentation problem. First, we construct a global lung shape to restrict the search region of the Kalman filter. Next, we proceed with augmenting the Kalman filter by incorporating an adaptive foreground detection system to provide the boundary contours for the Kalman filter to carry out the tracking of the conductivity changes as the lungs undergo deformation in a respiratory cycle. The proposed method has been validated by using performance statistics such as misclassified area, and false positive rate, and compared to previous approaches. The results show that the proposed automated method can be a fast and reliable segmentation tool for EIT imaging
Gender Differences in Immune Reconstitution: A Multicentric Cohort Analysis in Sub-Saharan Africa
In sub-Saharan Africa, men living with HIV often start ART at more advanced stages of disease and have higher early mortality than women. We investigated gender difference in long-term immune reconstitution
Primed T Cell Responses to Chemokines Are Regulated by the Immunoglobulin-Like Molecule CD31
CD31, an immunoglobulin-like molecule expressed by leukocytes and endothelial cells, is thought to contribute to the physiological regulation T cell homeostasis due to the presence of two immunotyrosine-based inhibitory motifs in its cytoplasmic tail. Indeed, loss of CD31 expression leads to uncontrolled T cell-mediated inflammation in a variety of experimental models of disease and certain CD31 polymorphisms correlate with increased disease severity in human graft-versus-host disease and atherosclerosis. The molecular mechanisms underlying CD31-mediated regulation of T cell responses have not yet been clarified. We here show that CD31-mediated signals attenuate T cell chemokinesis both in vitro and in vivo. This effect selectively affects activated/memory T lymphocytes, in which CD31 is clustered on the cell membrane where it segregates to the leading edge. We provide evidence that this molecular segregation, which does not occur in naïve T lymphocytes, might lead to cis-CD31 engagement on the same membrane and subsequent interference with the chemokine-induced PI3K/Akt signalling pathway. We propose that CD31-mediated modulation of memory T cell chemokinesis is a key mechanism by which this molecule contributes to the homeostatic regulation of effector T cell immunity
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