3,286 research outputs found
Analysis of GPS Satellite Allocation for the United States Nuclear Detonation Detection System (USNDS)
We present an approach for identifying salient input features in high feature to exemplar ratio conditions. Basically we modify the SNR saliency-screening algorithm to improve the solution of the optimal salient feature subset problem. We propose that applying the SNR method to randomly selected subsets (SRSS) has a superior potential to identify the salient features than the traditional SNR algorithm has. Two experimental studies are provided to demonstrate the consistency of the SRSS. In the first experiment we used a noise-corrupted version of the Fisher s Iris classification problem. The first experiment designed to prove the fidelity of the SRSS method. The second application is a real-life industrial problem. The salient features of this dataset are not known beforehand. We compared the performances of the salient feature subsets created by the traditional SNR and the SRSS method. We also realized that the SRSS algorithm improved the current solution to this industrial application
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
Factors affecting the Affordable Care Act Marketplace stand-alone pediatric dental plan premiums
BACKGROUND:
Children from lower income families have inadequate dental insurance coverage and poorer dental health in the United States. The Affordable Care Act (ACA) created Health Insurance Exchange Marketplaces to increase competition among health insurers and to provide low-income families with less costly health plans. The study examined Marketplace pediatric stand-alone dental plans (SADPs) and factors that affect their premiums.
METHODS:
The data used were 2016 Federal-Facilitated and State-Partnership Marketplace pediatric SADP data. Ordinary least squares regressions were applied to estimate contributing factors' effects on SADP premiums.
RESULTS:
Great premium variation was found among low and high coverage level SADPs, respectively. Premiums of Health Maintenance Organization (HMO) SADPs were significantly less expensive than Preferred Provider Organization (PPO) SADPs. SADPs charged significantly higher premiums for more types of services covered. SADPs also charged higher premiums in states where there are larger proportions of low-income people who report poor dental health, more dentists per capita, or higher dentists' wages. The number of insurance companies offering pediatric SADPs in a Marketplace was negatively associated with premiums.
CONCLUSION:
The current Marketplace pediatric SADPs may have limited effects on increasing economically disadvantaged children's access to quality dental care. Marketplaces can promote competition among its pediatric dental insurers on providing lower-cost pediatric SADPs
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
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
An Experimental investigation of chemical mass transfer processes in crystallizing, hydrous silicate magmas: The genesis of ore deposits and metasomatic fluids
This dissertation is comprised of three broadly related experimental petrology projects on phase equilibria and noble metal solubility in hydrous silicate melts. Chapters two and three combine experimental petrology with high precision laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis of experimental run products in order to quantitatively constrain the behavior of the investigated metals. Chapter four presents experimental evidence detailing a novel oxidation mechanism for degassing silicate liquids as well as exploring the geochemical consequences of the proposed mechanism.
Chapter two presents the results of an experimental study on Au, Pt, and Pd behavior in coexisting silicate melt-sulfide-oxide phase assemblages. Data from this study suggest the combined effect of oxygen and sulfur fugacity dictates the identity of stable magmatic sulfide phase assemblages, as well as dictating the concentration of Pt and Pd in monosulfide solid solution; both of these factors are critical components that determine metal tenor and the ore-deposit forming potential of a given magma.
Chapter three presents an experimental study of Au solubility in hydrous, chloride rich basaltic liquids as a function of oxygen fugacity (fO2). LA-ICP-MS determined Au concentrations in the quenched melt do not strictly adhere to the relationship between fO2 and Au solubility predicted for a monovalent Au oxide species. The observed relationship between Au and fO2 suggests the existence of alternative, non-oxide species in the melt. The solubility data presented in this chapter constrain the maximum Au concentration of natural hydrous basaltic liquids to values less than 2 ÎĽg g-1.
Chapter four presents experimental evidence suggesting a new mechanism for chloride degassing induced auto-oxidation of silicate liquids. The chemical exchange between silicate melts and chloride bearing fluids preferentially removes ferrous iron from the melt relative to ferric iron. The net effect of this preferential scavenging effect is to enrich the residual melt in ferric iron, increasing the melt’s intrinsic fO2. Dynamically changing magmatic oxygen fugacities profoundly affect the stability liquidus silicate phases in addition to potential sulfide phases involved in ore forming processes. (Refer to PDF file for exact formulas.
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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
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