1,039 research outputs found
Triage and diagnostic accuracy of Online Symptom Checkers: a systematic review
Background: In the context of a deepening global shortage of health workers, and particularly the COVID-19 pandemic, there is growing international interest in and use of online symptom checkers (OSCs). However, the evidence surrounding the safety and accuracy of OSCs remains inconclusive so far. The triage and diagnostic accuracy of these tools is an essential aspect that needs to be addressed before pushing any further implementation. Objective: This systematic review aimed to summarize the existing peer-reviewed literature evaluating the triage accuracy (directing users to appropriate services based on their presenting symptoms) and diagnostic accuracy of OSCs aimed at lay users for general health concerns. Methods: Searches were conducted in Medline, Embase, CINAHL, HMIC and Web of Science. We included peer-reviewed studies published in English between 1 January 2010 and 17 February 2022 with a quantitative assessment of triage and/or diagnostic accuracy of OSCs directed at lay users. We excluded tools supporting health professionals, and disease- or speciality-specific OSCs. Screening and data extraction were carried out independently by two reviewers for each study. We performed a descriptive narrative synthesis. Results: 21,284 studies were screened and 15 were included. Six studies reported on both triage and diagnostic accuracy, eight focused on triage accuracy, and one on diagnostic accuracy. Diagnostic and triage accuracy varied between studies and OSCs; most studies showed suboptimal diagnostic and triage accuracy. Frequency and urgency of the condition were the main variables that affected the levels of diagnostic and triage accuracy, along with specific features of the OSCs. The impact of each variable differed across tools and studies, making it difficult to draw any solid conclusions. Included studies had either a moderate or high risk of bias according to the revised tool for the Quality Assessment of Diagnostic Accuracy Studies 2. Conclusions: While OSCs have significant potential to provide accessible and accurate health advice and triage recommendations to users, more research is needed to validate their triage and diagnostic accuracy prior to wide scale adoption in community and healthcare settings. Future studies should aim to use a common methodology and/or agreed standard for evaluation to facilitate objective benchmarking and validation
Dynamic vehicle routing with time windows in theory and practice
The vehicle routing problem is a classical combinatorial optimization
problem. This work is about a variant of the vehicle routing problem
with dynamically changing orders and time windows. In real-world
applications often the demands change during operation time. New orders
occur and others are canceled. In this case new schedules need to be
generated on-the-fly. Online optimization algorithms for dynamical
vehicle routing address this problem but so far they do not consider
time windows. Moreover, to match the scenarios found in real-world
problems adaptations of benchmarks are required. In this paper, a
practical problem is modeled based on the procedure of daily routing of a
delivery company. New orders by customers are introduced dynamically
during the working day and need to be integrated into the schedule. A
multiple ant colony algorithm combined with powerful local search
procedures is proposed to solve the dynamic vehicle routing problem with
time windows. The performance is tested on a new benchmark based on
simulations of a working day. The problems are taken from Solomon’s
benchmarks but a certain percentage of the orders are only revealed to
the algorithm during operation time. Different versions of the MACS
algorithm are tested and a high performing variant is identified.
Finally, the algorithm is tested in situ: In a field study, the
algorithm schedules a fleet of cars for a surveillance company. We
compare the performance of the algorithm to that of the procedure used
by the company and we summarize insights gained from the implementation
of the real-world study. The results show that the multiple ant colony
algorithm can get a much better solution on the academic benchmark
problem and also can be integrated in a real-world environment
The MINERA Data Acquisition System and Infrastructure
MINERA (Main INjector ExpeRiment -A) is a new few-GeV neutrino
cross section experiment that began taking data in the FNAL NuMI (Fermi
National Accelerator Laboratory Neutrinos at the Main Injector) beam-line in
March of 2010. MINERA employs a fine-grained scintillator detector capable
of complete kinematic characterization of neutrino interactions. This paper
describes the MINERA data acquisition system (DAQ) including the read-out
electronics, software, and computing architecture.Comment: 34 pages, 16 figure
Rapid development of non-alcoholic steatohepatitis in Psammomys obesus (Israeli sand rat)
Background and Aims: A major impediment to establishing new treatments for non-alcoholic steatohepatitis is the lack of suitable animal models that accurately mimic the biochemical and metabolic characteristics of the disease. The aim of this study was to explore a unique polygenic animal model of metabolic disease as a model of non-alcoholic steatohepatitis by determining the effects of 2% dietary cholesterol supplementation on metabolic and liver endpoints in Psammomys obesus (Israeli sand rat). Methods: P. obesus were provided ad libitum access to either a standard rodent diet (20% kcal/fat) or a standard rodent diet supplemented with 2% cholesterol (w/w) for 4 weeks. Histological sections of liver from animals on both diets were examined for key features of non-alcoholic steatohepatitis. The expression levels of key genes involved in hepatic lipid metabolism were measured by real-time PCR. Results: P. obesus fed a cholesterol-supplemented diet exhibited profound hepatomegaly and steatosis, and higher plasma transaminase levels. Histological analysis identified extensive steatosis, inflammation, hepatocyte injury and fibrosis. Hepatic gene expression profiling revealed decreased expression of genes involved in delivery and uptake of lipids, and fatty acid and triglyceride synthesis, and increased expression of genes involved in very low density lipoprotein cholesterol synthesis, triglyceride and cholesterol export. Conclusions: P. obesus rapidly develop non-alcoholic steatohepatitis when fed a cholesterol-supplemented diet that appears to be histologically and mechanistically similar to patients. © 2014 Spolding et al
Single neutral pion production by charged-current interactions on hydrocarbon at 3.6 GeV
Single neutral pion production via muon antineutrino charged-current
interactions in plastic scintillator (CH) is studied using the \minerva
detector exposed to the NuMI low-energy, wideband antineutrino beam at
Fermilab. Measurement of this process constrains models of neutral pion
production in nuclei, which is important because the neutral-current analog is
a background for appearance oscillation experiments. The
differential cross sections for momentum and production angle, for
events with a single observed and no charged pions, are presented and
compared to model predictions. These results comprise the first measurement of
the kinematics for this process.Comment: 6 pages, 5 figures, submitted to Physics Letters
MINERvA neutrino detector response measured with test beam data
The MINERvA collaboration operated a scaled-down replica of the solid
scintillator tracking and sampling calorimeter regions of the MINERvA detector
in a hadron test beam at the Fermilab Test Beam Facility. This article reports
measurements with samples of protons, pions, and electrons from 0.35 to 2.0
GeV/c momentum. The calorimetric response to protons, pions, and electrons are
obtained from these data. A measurement of the parameter in Birks' law and an
estimate of the tracking efficiency are extracted from the proton sample.
Overall the data are well described by a Geant4-based Monte Carlo simulation of
the detector and particle interactions with agreements better than 4%, though
some features of the data are not precisely modeled. These measurements are
used to tune the MINERvA detector simulation and evaluate systematic
uncertainties in support of the MINERvA neutrino cross section measurement
program.Comment: as accepted by NIM
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