2,628 research outputs found
An assessment of the Space Station Freedom program's leakage current requirement
The Space Station Freedom Program requires leakage currents to be limited to less than human perception level, which NASA presently defines as 5 mA for dc. The origin of this value is traced, and the literature for other dc perception threshold standards is surveyed. It is shown that while many varying standards exist, very little experimental data is available to support them
Neural networks versus Logistic regression for 30 days all-cause readmission prediction
Heart failure (HF) is one of the leading causes of hospital admissions in the
US. Readmission within 30 days after a HF hospitalization is both a recognized
indicator for disease progression and a source of considerable financial burden
to the healthcare system. Consequently, the identification of patients at risk
for readmission is a key step in improving disease management and patient
outcome. In this work, we used a large administrative claims dataset to
(1)explore the systematic application of neural network-based models versus
logistic regression for predicting 30 days all-cause readmission after
discharge from a HF admission, and (2)to examine the additive value of
patients' hospitalization timelines on prediction performance. Based on data
from 272,778 (49% female) patients with a mean (SD) age of 73 years (14) and
343,328 HF admissions (67% of total admissions), we trained and tested our
predictive readmission models following a stratified 5-fold cross-validation
scheme. Among the deep learning approaches, a recurrent neural network (RNN)
combined with conditional random fields (CRF) model (RNNCRF) achieved the best
performance in readmission prediction with 0.642 AUC (95% CI, 0.640-0.645).
Other models, such as those based on RNN, convolutional neural networks and CRF
alone had lower performance, with a non-timeline based model (MLP) performing
worst. A competitive model based on logistic regression with LASSO achieved a
performance of 0.643 AUC (95%CI, 0.640-0.646). We conclude that data from
patient timelines improve 30 day readmission prediction for neural
network-based models, that a logistic regression with LASSO has equal
performance to the best neural network model and that the use of administrative
data result in competitive performance compared to published approaches based
on richer clinical datasets
Mining Images in Biomedical Publications: Detection and Analysis of Gel Diagrams
Authors of biomedical publications use gel images to report experimental
results such as protein-protein interactions or protein expressions under
different conditions. Gel images offer a concise way to communicate such
findings, not all of which need to be explicitly discussed in the article text.
This fact together with the abundance of gel images and their shared common
patterns makes them prime candidates for automated image mining and parsing. We
introduce an approach for the detection of gel images, and present a workflow
to analyze them. We are able to detect gel segments and panels at high
accuracy, and present preliminary results for the identification of gene names
in these images. While we cannot provide a complete solution at this point, we
present evidence that this kind of image mining is feasible.Comment: arXiv admin note: substantial text overlap with arXiv:1209.148
Long-term environmental stewardship.
The purpose of this Supplemental Information Source Document is to effectively describe Long-Term Environmental Stewardship (LTES) at Sandia National Laboratories/New Mexico (SNL/NM). More specifically, this document describes the LTES and Long-Term Stewardship (LTS) Programs, distinguishes between the LTES and LTS Programs, and summarizes the current status of the Environmental Restoration (ER) Project
Strict width for Constraint Satisfaction Problems over homogeneous strucures of finite duality
We investigate the `local consistency implies global consistency' principle
of strict width among structures within the scope of the Bodirsky-Pinsker
dichotomy conjecture for infinite-domain Constraint Satisfaction Problems
(CSPs). Our main result implies that for certain CSP templates within the scope
of that conjecture, having bounded strict width has a concrete consequence on
the expressive power of the template called implicational simplicity. This in
turn yields an explicit bound on the relational width of the CSP, i.e., the
amount of local consistency needed to ensure the satisfiability of any
instance. Our result applies to first-order expansions of any homogeneous
-uniform hypergraph, but more generally to any CSP template under the
assumption of finite duality and general abstract conditions mainly on its
automorphism group. In particular, it overcomes the restriction to binary
signatures in the pioneering work of Wrona.Comment: 22 page
A red/far-red light-responsive bi-stable toggle switch to control gene expression in mammalian cells
Growth and differentiation of multicellular systems is orchestrated by spatially restricted gene expression programs in specialized subpopulations. The targeted manipulation of such processes by synthetic tools with high-spatiotemporal resolution could, therefore, enable a deepened understanding of developmental processes and open new opportunities in tissue engineering. Here, we describe the first red/far-red light-triggered gene switch for mammalian cells for achieving gene expression control in time and space. We show that the system can reversibly be toggled between stable on- and off-states using short light pulses at 660 or 740 nm. Red light-induced gene expression was shown to correlate with the applied photon number and was compatible with different mammalian cell lines, including human primary cells. The light-induced expression kinetics were quantitatively analyzed by a mathematical model. We apply the system for the spatially controlled engineering of angiogenesis in chicken embryos. The system's performance combined with cell- and tissue-compatible regulating red light will enable unprecedented spatiotemporally controlled molecular interventions in mammalian cells, tissues and organisms
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