Comparing the utilization and cost of health services between veterans experiencing brief and ongoing episodes of housing instability

Housing instability is associated with costly patterns of health and behavioral health service use. However, little prior research has examined patterns of service use associated with higher costs among those experiencing ongoing housing instability. To address this gap, we compared inpatient and outpatient medical and behavioral health service utilization and costs between veterans experiencing brief and ongoing episodes of housing instability. We used data from a brief screening instrument for homelessness and housing instability that has been implemented throughout the US Department of Veterans Affairs (VA) health care system to identify a national sample of veterans experiencing housing instability. Veterans were classified as experiencing either brief or ongoing housing instability, based on two consecutive responses to the instrument, and we used a series of two-part regression models to conduct adjusted comparisons of costs between veterans experiencing brief and ongoing episodes of housing instability. Among 5794 veterans screening positive for housing instability, 4934 (85%) were experiencing brief and 860 (15%) ongoing instability. The average total annual incremental cost associated with ongoing versus brief episodes of housing instability was estimated at $7573, with the bulk of this difference found in inpatient services. Cost differences resulted more from a higher probability of service use among those experiencing ongoing episodes of housing instability than from higher costs among service users. Our findings suggest that VA programmatic efforts aimed at preventing extended episodes of housing instability could potentially result in substantial cost offsets for the VA health care system.This study was supported by funding from the Department of Veterans Affairs (VA) Health Services Research & Development (HSR&D) grant IIR 13-334-3 and from the VA National Center on Homelessness Among Veterans

Rurality or distance to care and the risk of homelessness among Afghanistan and Iraq veterans

INTRODUCTION: To date, no studies have examined the relationship of rurality and distance to nearest VA facility to risk of homelessness. METHODS: We examined differences in the rate of homelessness within a year of a Veteran's first encounter with the VA following last military separation based on rurality and distance to the nearest VA facility using multivariable log-binomial regressions. RESULTS: In our cohort of 708,120 Veterans, 73% were determined to have a forwarding address in urban areas, 59.2% and 86.7% lived within 40 miles of the nearest VA medical center (VAMC), respectively. Veterans living in a rural area and those living between 20+ miles away from the nearest VAMC were at a lower risk for homelessness. CONCLUSIONS: Our unique dataset allowed us to explore the relationship between geography and homelessness. These results are important to policy makers in understanding the risk factors for homelessness among Veterans and planning interventions

Rushes video summarization using a collaborative approach

This paper describes the video summarization system developed by the partners of the K-Space European Network of Excellence for the TRECVID 2008 BBC rushes summarization evaluation. We propose an original method based on individual content segmentation and selection tools in a collaborative system. Our system is organized in several steps. First, we segment the video, secondly we identify relevant and redundant segments, and finally, we select a subset of segments to concatenate and build the final summary with video acceleration incorporated. We analyze the performance of our system through the TRECVID evaluation

A Mathematical Model of Liver Cell Aggregation In Vitro

The behavior of mammalian cells within three-dimensional structures is an area of intense biological research and underpins the efforts of tissue engineers to regenerate human tissues for clinical applications. In the particular case of hepatocytes (liver cells), the formation of spheroidal multicellular aggregates has been shown to improve cell viability and functionality compared to traditional monolayer culture techniques. We propose a simple mathematical model for the early stages of this aggregation process, when cell clusters form on the surface of the extracellular matrix (ECM) layer on which they are seeded. We focus on interactions between the cells and the viscoelastic ECM substrate. Governing equations for the cells, culture medium, and ECM are derived using the principles of mass and momentum balance. The model is then reduced to a system of four partial differential equations, which are investigated analytically and numerically. The model predicts that provided cells are seeded at a suitable density, aggregates with clearly defined boundaries and a spatially uniform cell density on the interior will form. While the mechanical properties of the ECM do not appear to have a significant effect, strong cell-ECM interactions can inhibit, or possibly prevent, the formation of aggregates. The paper concludes with a discussion of our key findings and suggestions for future work

Characterising white matter in Huntington's disease

Background: Investigating early white matter (WM) change in Huntington’s Disease (HD) can improve our understanding of the way in which disease spreads from the striatum. Objectives: Here, we provide a detailed characterisation of pathology-related WM change in HD. We first examined WM microstructure using diffusion-weighted imaging, then investigated both underlying biological properties of WM and products of WM damage including iron, myelin plus neurofilament light (NfL), a biofluid marker of axonal degeneration – in parallel with the mutant huntingtin protein (mHTT). Methods: We examined WM change in HD gene-carriers from the HD-CSF cohort, baseline visit. We used standard diffusion MRI to measure metrics including fractional anisotropy (FA), a marker of WM integrity, and diffusivity; a novel diffusion model (NODDI) to measure axonal density and organisation; T1 and T2 weighted structural MRI images to derive proxy iron content and myelin-contrast measures; and biofluid concentrations of NfL (in CSF and plasma) and mHTT (in CSF). Results: HD gene-carriers displayed reduced FA and increased diffusivity compared to controls, both of which were also associated with disease progression, CSF and mHTT levels. HD gene-carriers also displayed proxy measures of reduced myelin-contrast and iron in the striatum. Conclusion: Collectively, these findings present a more complete characterisation of HD-related microstructural brain changes. Correlation between reduced FA, increased axonal orientation and biofluid markers suggest that axonal breakdown is associated with increased WM degeneration, while higher quantitative T2 signal and lower myelin-contrast may indicate a process of demyelination limited to the striatum

The Putative Cerean Exosphere

The ice-rich crust of dwarf planet 1 Ceres is the source of a tenuous water exosphere, and the behavior of thisputative exosphere is investigated with model calculations. Outgassing water molecules seasonally condensearound the winter pole in an optically thin layer

Predicting radiotherapy patient outcomes with real-time clinical data using mathematical modelling

Longitudinal tumour volume data from head-and-neck cancer patients show that tumours of comparable pre-treatment size and stage may respond very differently to the same radiotherapy fractionation protocol. Mathematical models are often proposed to predict treatment outcome in this context, and have the potential to guide clinical decision-making and inform personalised fractionation protocols. Hindering effective use of models in this context is the sparsity of clinical measurements juxtaposed with the model complexity required to produce the full range of possible patient responses. In this work, we present a compartment model of tumour volume and tumour composition, which, despite relative simplicity, is capable of producing a wide range of patient responses. We then develop novel statistical methodology and leverage a cohort of existing clinical data to produce a predictive model of both tumour volume progression and the associated level of uncertainty that evolves throughout a patient’s course of treatment. To capture inter-patient variability, all model parameters are patient specific, with a bootstrap particle filter-like Bayesian approach developed to model a set of training data as prior knowledge. We validate our approach against a subset of unseen data, and demonstrate both the predictive ability of our trained model and its limitations

Deciphering the structural history of Ulysses Fossae, Mars, using fault pattern analysis

Ulysses Fossae is a faulted region surrounded by lava flows that sits between the major volcanoes of the Tharsis Rise volcanic province on Mars. This area is unique, as it is the only exposure of extensional faulting which can be related to the Olympus Mons volcano and one of the only a few faulted areas relating to the Tharsis Montes. In order to determine the area's structural evolution through time, we mapped all identifiable faults, divided them into 10 fault groups determined by their orientation and morphology, and performed detailed crater size-frequency analysis of the geological units. We divide the fault groups into two overall types based on their genesis: local diking and regional extension. The complex structural evolution recorded in the extensional faults in Ulysses Fossae is dominated by local dike-related activity (8/10 fault groups), along with deformation from large, regional scale extensional processes related to the development of the Tharsis province as a whole (2/10 fault groups). Strain values measured across the 1 fault groups vary between 0.4%–2.2%, with the grabens related to regional extension accommodating larger extensional strains than the local dike-related grabens. The crater size-frequency distribution analysis of three distinct areas in Ulysses Fossae (UF Dome, UF North, and UF South) revealed that the majority of the faulting in Ulysses Fossae was active during the Early Amazonian

The Evaluation of V_{ud}, Experiment and Theory

The value of the V_{ud} matrix element of the Cabibbo-Kobayashi-Maskawa (CKM) matrix can be derived from nuclear superallowed beta decays, neutron decay, and pion beta decay. We survey current world data for all three. Today, the most precise value of V_{ud} comes from the nuclear decays; however, the precision is limited not by experimental error but by the estimated uncertainty in theoretical corrections. Experimental uncertainty does limit the neutron-decay result, which, though statistically consistent with the nuclear result, is approximately a factor of three poorer in precision. The value obtained for $V_{ud}$ leads to a result that differs at the 98% confidence level from the unitarity condition for the CKM matrix. We examine the reliability of the small calculated corrections that have been applied to the data, and assess the likelihood of even higher quality nuclear data becoming available to confirm or deny the discrepancy. Some of the required experiments depend upon the availability of intense radioactive beams. Others are possible today.Comment: 21 pages, 1 figure, LaTe