5,142 research outputs found
Utilizing AI in Temporal, Spatial, and Resource Scheduling
Aurora is a software system enabling the rapid, easy solution of complex scheduling problems involving spatial and temporal constraints among operations and scarce resources (such as equipment, workspace, and human experts). Although developed for use in the International Space Station Processing Facility, Aurora is flexible enough that it can be easily customized for application to other scheduling domains and adapted as the requirements change or become more precisely known over time. Aurora s scheduling module utilizes artificial-intelligence (AI) techniques to make scheduling decisions on the basis of domain knowledge, including knowledge of constraints and their relative importance, interdependencies among operations, and possibly frequent changes in governing schedule requirements. Unlike many other scheduling software systems, Aurora focuses on resource requirements and temporal scheduling in combination. For example, Aurora can accommodate a domain requirement to schedule two subsequent operations to locations adjacent to a shared resource. The graphical interface allows the user to quickly visualize the schedule and perform changes reflecting additional knowledge or alterations in the situation. For example, the user might drag the activity corresponding to the start of operations to reflect a late delivery
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A pragmatic patient-reported outcome strategy for rare disease clinical trials: application of the EORTC item library to myelodysplastic syndromes, chronic myelomonocytic leukemia, and acute myeloid leukemia.
BackgroundNovel, pragmatic, patient-centered strategies are needed to ensure fit-for-purpose patient-reported outcomes (PRO) instruments in clinical trial research for rare diseases such as myelodysplastic syndromes (MDS), acute myeloid leukemia (AML), and chronic myelomonocytic leukemia (CMML). The objective of the current study was to select supplemental items to add to the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life-Core 30 (QLQ-C30) to ensure content coverage of all important clinical concepts in patients with higher-risk (HR) MDS, low-blast count (LB) AML, and CMML, thus, improving the instrument's ability to detect clinically meaningful treatment benefit for this context of use.MethodsOur mixed methods approach comprised literature review, clinician consultation (n = 3), and qualitative and quantitative analysis of two stages of patient interview data (n = 14, n = 18) to select library bank items to supplement a generic cancer PRO, the EORTC QLQ-C30.ResultsUnique symptom (n = 54) and impact (n = 72) concepts were organized into conceptual frameworks of treatment benefit, compared with EORTC QLQ-C30 items and conceptual gaps identified. Supplemental items (n = 13) addressing those gaps were selected from the EORTC Item Library and tested with patients. Supplemental item endorsement frequencies met World Health Organization Quality of Life criteria, suggesting good targeting and relevance for this sample. However, three supplemental items were confirmed as problematic based upon cognitive debriefing results, and expert clinical consultations. Ultimately, 10 supplemental items (n = 7 symptom; n = 3 impact) were selected for the MDS/AML/CMML context.ConclusionSupplemental items were selected to enhance the conceptual coverage of the EORTC QLQ-C30 in the areas of fatigue, shortness of breath, and functioning
A Potential Role for the Interaction of Wolbachia Surface Proteins with the Brugia malayi Glycolytic Enzymes and Cytoskeleton in Maintenance of Endosymbiosis
The human filarial parasite Brugia malayi harbors an endosymbiotic bacterium of the genus Wolbachia. The Wolbachia represent an attractive target for the control of filarial induced disease as elimination of the bacteria affects molting, reproduction and survival of the worms. The molecular basis for the symbiotic relationship between Wolbachia and their filarial hosts has yet to be elucidated. To identify proteins involved in this process, we focused on the Wolbachia surface proteins (WSPs), which are known to be involved in bacteria-host interactions in other bacterial systems. Two WSP-like proteins (wBm0152 and wBm0432) were localized to various host tissues of the B. malayi female adult worms and are present in the excretory/secretory products of the worms. We provide evidence that both of these proteins bind specifically to B. malayi crude protein extracts and to individual filarial proteins to create functional complexes. The wBm0432 interacts with several key enzymes involved in the host glycolytic pathway, including aldolase and enolase. The wBm0152 interacts with the host cytoskeletal proteins actin and tubulin. We also show these interactions in vitro and have verified that wBm0432 and B. malayi aldolase, as well as wBm0152 and B. malayi actin, co-localize to the vacuole surrounding Wolbachia. We propose that both WSP protein complexes interact with each other via the aldolase-actin link and/or via the possible interaction between the host's enolase and the cytoskeleton, and play a role in Wolbachia distribution during worm growth and embryogenesis. © 2013 Melnikow et al
Massive Dirac fermions in a ferromagnetic kagome metal
The kagome lattice is a two-dimensional network of corner-sharing triangles
known as a platform for exotic quantum magnetic states. Theoretical work has
predicted that the kagome lattice may also host Dirac electronic states that
could lead to topological and Chern insulating phases, but these have evaded
experimental detection to date. Here we study the d-electron kagome metal
FeSn designed to support bulk massive Dirac fermions in the presence of
ferromagnetic order. We observe a temperature independent intrinsic anomalous
Hall conductivity persisting above room temperature suggestive of prominent
Berry curvature from the time-reversal breaking electronic bands of the kagome
plane. Using angle-resolved photoemission, we discover a pair of quasi-2D Dirac
cones near the Fermi level with a 30 meV mass gap that accounts for the Berry
curvature-induced Hall conductivity. We show this behavior is a consequence of
the underlying symmetry properties of the bilayer kagome lattice in the
ferromagnetic state with atomic spin-orbit coupling. This report provides the
first evidence for a ferromagnetic kagome metal and an example of emergent
topological electronic properties in a correlated electron system. This offers
insight into recent discoveries of exotic electronic behavior in kagome lattice
antiferromagnets and may provide a stepping stone toward lattice model
realizations of fractional topological quantum states.Comment: 19 pages, 4 figure
Dobutamine stress MR in Tetralogy of Fallot with significant pulmonary regurgitation, safety, feasibility and haemodynamic effects
Introduction In Tetralogy of Fallot (TOF) late after repair, severe pulmonary regurgitation (PR) places the patient at risk for right ventricular (RV) dilatation and failure, arrhythmia and sudden cardiac death. Criteria for pulmonary valve replacement continue to be debated. Dobutamine stress MR (DS-MR) may improve diagnostic sensitivity to detect early RV dysfunction. We sought to investigate safety, feasibility and haemodynamic effect of DS-MR. Methods We prospectively recruited 28 adult patients referred for cardiac MR (age 32±15) with repaired TOF, RV dilatation and severe PR on echocardiography. Exclusion criteria: Contraindications to MR, history of arrhythmia, severely impaired left ventricular (LV) function, severe aortic valve disease, and severe pulmonary stenosis. Ventricular volumes (axial 2D cine SSFP) and pulmonary artery and aortic flows (phase contrast) were obtained at baseline and during dobutamine infusion of 10 mcg/kg/min (stage 1) and 20 mcg/kg/min (stage 2). DS-MR was stopped when systolic blood pressure >190 mmHg, heart rate >75% predicted (220-age) or if patients experienced significant side effects. Results Of the 28 patients, 24 completed stage 1 DS-MR (two subject experienced claustrophobia and two had failure of VECG triggering secondary to frequent ventricular ectopics not present during baseline scanning. Four of these 24 patients could not progress to Stage 2, due to either minor dobutamine side effects (nausea or headache, n=2) or achievement of >75% maximum predicted heart rate (n=2). Twenty patients went on to complete stage 2 DS-MR and no additional side effects were observed. Two data sets at stage 2 were excluded from analysis due to incomplete volumetric measurements. The heart rate (cardiac index) increased from 66±6 bpm (2.9±0.4 l/min/m2) at baseline to 91±18 bpm (3.9±0.9 l/min/m2) at Stage 1 and 117±14 bpm (4.5±1 l/min/m2) at Stage 2 (p<0.01). Significant reduction in LV end diastolic (EDV) and end systolic volumes (ESV) is seen at dobutamine 10 and 20 (p<0.01). In the RV there is a less marked reduction in volumes at 10 while at 20 mcg dobutamine there is no significant change in ESV in a sub-group (p=0.63
Numerosity and density judgments: Biases for area but not for volume
International audienceHuman observers can rapidly judge the number of items in a scene. This ability is underpinned by specific mechanisms encoding number or density. We investigated whether judgments of number and density are biased by a change in volume, as they are by a change in area. Stimuli were constructed using nonoverlapping black and white luminance-defined dots. An eight-mirror Wheatstone stereoscope was used to present the dots as though in a volume. Using a temporal two-alternative forced-choice (2AFC) task and the Method of Constant Stimuli (MOCS), we measured the precision and bias (PSE shift) of numerosity and density judgments, separately, for stimuli differing in area or volume. For two-dimensional (2-D) stimuli, consistent with previous literature, perceived density was biased as area increased. However, perceived number was not. For three-dimensional (3-D) stimuli, despite a vivid impression of the dots filling a cylindrical volume, there was no bias in perceived density or number as volume increased. A control experiment showed that all of our observers could easily perceive disparity in our stimuli. Our findings reveal that number and density judgments that are biased by area are not similarly biased by volume changes
Prescription drug monitoring program data tracking of opioid addiction treatment outcomes in integrated dual diagnosis care involving injectable naltrexone
BACKGROUND AND OBJECTIVES: Fourfold increases in opioid prescribing and dispensations over 2 decades in the U.S. has paralleled increases in opioid addictions and overdoses, requiring new preventative, diagnostic, and treatment strategies. This study examines Prescription Drug Monitoring Program (PDMP) tracking as a novel measure of opioid addiction treatment outcomes in a university-affiliated integrated mental health-addiction treatment clinic.
METHODS: Repeated measure parametrics examined PDMP and urine drug screening (UDS) data before and after first injection for all patients (N = 68) who received at least one long-acting naltrexone injection (380 mg/IM) according to diagnostic groupings of having either (i) alcohol (control); (ii) opioid; or (iii) combined alcohol and opioid use disorders.
RESULTS: There were no group differences post-injection in treatment days, injections delivered, or treatment service encounters. UDS and PDMP measures of opioid exposures were greater in opioid compared to alcohol-only patients. Post-first injection, UDS's positive for opioids declined (p < .05) along with PDMP measures of opioid prescriptions (p < .001), doses (p < .01), types (p < .001), numbers of dispensing prescribers (p < .001) and pharmacies (p < .001). Opioid patients without alcohol disorders showed the best outcomes with 50% to 80% reductions in PDMP-measures of opioids, down to levels of alcohol-only patients.
CONCLUSIONS: This study shows PDMP utility for measuring opioid addiction treatment outcomes, supporting the routine use of PDMPs in clinical and research settings.
SCIENTIFIC SIGNIFICANCE: These findings demonstrate that opioid addiction in patients with complex addictions and mental illnesses comorbidities can show effective treatment responses as measured by PDMP tracking of decreases in opioid prescriptions to those patients. (Am J Addict 2016;25:557-564)
The effect of Warm Dark Matter on galaxy properties: constraints from the stellar mass function and the Tully-Fisher relation
In this paper we combine high resolution N-body simulations with a semi
analytical model of galaxy formation to study the effects of a possible Warm
Dark Matter (WDM) component on the observable properties of galaxies. We
compare three WDM models with a dark matter mass of 0.5, 0.75 and 2.0 keV, with
the standard Cold Dark Matter case. For a fixed set of parameters describing
the baryonic physics the WDM models predict less galaxies at low (stellar)
masses, as expected due to the suppression of power on small scales, while no
substantial difference is found at the high mass end. However these differences
in the stellar mass function, vanish when different set of parameters are used
to describe the (largely unknown) galaxy formation processes. We show that is
possible to break this degeneracy between DM properties and the
parameterization of baryonic physics by combining observations on the stellar
mass function with the Tully-Fisher relation (the relation between stellar mass
and the rotation velocity at large galactic radii as probed by resolved HI
rotation curves). WDM models with a too warm candidate (m<0.75 keV) cannot
simultaneously reproduce the stellar mass function and the Tully-Fisher
relation. We conclude that accurate measurements of the galaxy stellar mass
function and the link between galaxies and dark matter haloes down to the very
low-mass end can give very tight constraints on the nature of DM candidates.Comment: 8 pages, 5 figures, minor changes, accepted for publication on Ap
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