Creating national weights for a patient-level longitudinal database

Onur Başer (MEF Author)##nofulltext##To create a nationally-representative estimate from longitudinal data by controlling for sociodemographic factors and health status. The Agency for Healthcare Research and Quality’s (AHRQ) Medicare Expenditures Panel Survey (MEPS) was used as the basis for adjustment methodology. MEPS is a data source representing health insurance coverage cost and utilization, and comprises several large-scale surveys of families, individuals, employers, and health care providers. Using these data, we created subset populations. We then used multivariate logistic regression to construct demographics and case-mix-based weights, which were applied to create a population sample that is similar to the national population. The weight was derived using the inverse probability of the weighting approach, as well as a raking mechanism. We compared the results with the projected number of persons in the US population in the same categories to examine the validity of the weights. The following variables were used in the logistic regression: Age group, gender, race, location, income level and health status (Charlson Comorbidity Index scores and chronic condition diagnosis). Relative to MEPS data, patients included in the private insurance data were more likely to be male, older, to have a chronic condition, and to be white (p=0.0000). Adjusted weighted values for patients in the commercial group ranged from 15.47 to 36.36 (median: 16.91). Commercial insurance and MEPS data populations were similar in terms of their socioeconomic and clinical categories. As an outcomes measure, the predicted annual number of patients with prescription claims from private insurance data was 6 963 034. The annual number of statin users were predicted as 6 709 438 using weighted MEPS data. National projections of large-scale patient longitudinal databases require adjustment utilizing demographic factors and case-mix differences related to health status

Low cost fault-tolerant routing algorithm for Networks-on-Chip

A novel adaptive routing algorithm - Efficient Dynamic Adaptive Routing (EDAR) is proposed to provide a fault-tolerant capability for Networks-on-Chip (NoC) via an efficient routing path selection mechanism. It is based on a weighted path selection strategy, which exploits the status of real-time NoC traffic made available via monitor modules. The key performance goal is to maintain throughput under congested and faulty conditions via effective routing path decisions. In the proposed EDAR, port weights are calculated in real-time according to the channel status – Idle/Busy/Congested/Faulty, and the port with the lowest weighting is ranked as the near-optimal route to forward packets. This mechanism enables the router to bypass congested ports and tolerate faulty ports. To assess the latency and throughput of the proposed routing algorithm, several traffic patterns for both fault-free and faulty NoCs were evaluated. Results show that EDAR can achieve higher throughput compared to other state of the art routing algorithms under various traffic patterns and levels of injected faults. In addition, the hardware area overhead for EDAR is demonstrated to have a reasonably low cost which maintains scalability for large NoC implementations

Development of a Short Trauma Screening Tool (STST) to Measure Child Trauma Symptoms: Establishing Content Validity

Purpose: The purpose of the study was to identify major symptom domain variables common to child trauma and create a prototype short trauma symptom screening tool (STST) intended for use in pediatric medical settings. Methods: This manuscript describes the first two phases of an on-going prospective mixed-method instrument development study. Phase 1 exploratory factor analysis was conducted with an archived LONGSCAN CBCL dataset to: (1) identify behavioral symptoms endorsed by children with known trauma exposure; and (2) generate a preliminary STST item pool. During Phase 2, researchers convened an expert panel (N = 10) and conducted Content Validity Index (CVI) procedures with the 20-item preliminary STST item pool, to further inform item retention, elimination and modification for an updated prototype STST. Findings: Expert quantitative scores yielded a CVI of 0.90 for the overall preliminary STST. The first two phases of this study assisted researchers with identifying 12 items that represent nine child trauma symptom domain variables, which include: (1) aggression/anger; (2) anxiety/fear; (3) sexual concerns; (4) elimination concerns; (5) somatic concerns; (6) depression; (7) dissociation; (8) physical acting out; and (9) dysregulation. Conclusions: The first two phases of STST development resulted in development of a brief, empirically-derived prototype screening tool that features 12 items operationalizing nine domains of child trauma symptoms. Developers can now advance to the next phase of STST development; feasibility assessment and psychometric testing

Tonic inhibition of accumbal spiny neurons by extrasynaptic 4 GABAA receptors modulates the actions of psychostimulants

Within the nucleus accumbens (NAc), synaptic GABAA receptors (GABAARs) mediate phasic inhibition of medium spiny neurons (MSNs) and influence behavioral responses to cocaine. We demonstrate that both dopamine D1- and D2-receptor-expressing MSNs (D-MSNs) additionally harbor extrasynaptic GABAARs incorporating α4, β, and δ subunits that mediate tonic inhibition, thereby influencing neuronal excitability. Both the selective δ-GABAAR agonist THIP and DS2, a selective positive allosteric modulator, greatly increased the tonic current of all MSNs from wild-type (WT), but not from δ−/− or α4−/− mice. Coupling dopamine and tonic inhibition, the acute activation of D1 receptors (by a selective agonist or indirectly by amphetamine) greatly enhanced tonic inhibition in D1-MSNs but not D2-MSNs. In contrast, prolonged D2 receptor activation modestly reduced the tonic conductance of D2-MSNs. Behaviorally, WT and constitutive α4−/− mice did not differ in their expression of cocaine-conditioned place preference (CPP). Importantly, however, mice with the α4 deletion specific to D1-expressing neurons (α4D1−/−) showed increased CPP. Furthermore, THIP administered systemically or directly into the NAc of WT, but not α4−/− or α4D1−/− mice, blocked cocaine enhancement of CPP. In comparison, α4D2−/− mice exhibited normal CPP, but no cocaine enhancement. In conclusion, dopamine modulation of GABAergic tonic inhibition of D1- and D2-MSNs provides an intrinsic mechanism to differentially affect their excitability in response to psychostimulants and thereby influence their ability to potentiate conditioned reward. Therefore, α4βδ GABAARs may represent a viable target for the development of novel therapeutics to better understand and influence addictive behaviors

Using late-time optical and near-infrared spectra to constrain Type Ia supernova explosion properties

The late-time spectra of Type Ia supernovae (SNe Ia) are powerful probes of the underlying physics of their explosions. We investigate the late-time optical and near-infrared spectra of seven SNe Ia obtained at the VLT with XShooter at $>$200 d after explosion. At these epochs, the inner Fe-rich ejecta can be studied. We use a line-fitting analysis to determine the relative line fluxes, velocity shifts, and line widths of prominent features contributing to the spectra ([Fe II], [Ni II], and [Co III]). By focussing on [Fe II] and [Ni II] emission lines in the ~7000-7500 \AA\ region of the spectrum, we find that the ratio of stable [Ni II] to mainly radioactively-produced [Fe II] for most SNe Ia in the sample is consistent with Chandrasekhar-mass delayed-detonation explosion models, as well as sub-Chandrasekhar mass explosions that have metallicity values above solar. The mean measured Ni/Fe abundance of our sample is consistent with the solar value. The more highly ionised [Co III] emission lines are found to be more centrally located in the ejecta and have broader lines than the [Fe II] and [Ni II] features. Our analysis also strengthens previous results that SNe Ia with higher Si II velocities at maximum light preferentially display blueshifted [Fe II] 7155 \AA\ lines at late times. Our combined results lead us to speculate that the majority of normal SN Ia explosions produce ejecta distributions that deviate significantly from spherical symmetry.Comment: 17 pages, 12 figure, accepted for publication in MNRA

Interacting supernovae and supernova impostors. SN 2007sv: the major eruption of a massive star in UGC 5979

We report the results of the photometric and spectroscopic monitoring campaign of the transient SN 2007sv. The observables are similar to those of type IIn supernovae, a well-known class of objects whose ejecta interact with pre-existing circum-stellar material. The spectra show a blue continuum at early phases and prominent Balmer lines in emission, however, the absolute magnitude at the discovery of SN 2007sv (M_R = - 14.25 +/- 0.38) indicate it to be most likely a supernova impostor. This classification is also supported by the lack of evidence in the spectra of very high velocity material as expected in supernova ejecta. In addition we find no unequivocal evidence of broad lines of alpha - and/or Fe-peak elements. The comparison with the absolute light curves of other interacting objects (including type IIn supernovae) highlights the overall similarity with the prototypical impostor SN 1997bs. This supports our claim that SN 2007sv was not a genuine supernova, and was instead a supernova impostor, most likely similar to the major eruption of a luminous blue variable.Comment: Accepted for publication in MNRAS. 15 pages, 11 figures, 5 table

Mefloquine Is Highly Efficacious against Chloroquine-Resistant \u3ci\u3ePlasmodium vivax\u3c/i\u3e Malaria and \u3ci\u3ePlasmodium falciparum\u3c/i\u3e Malaria in Papua, Indonesia

Background. During the period of 1996–1999, we prospectively monitored 243 Javanese adults and children after arriving in Papua, Indonesia, and microscopically documented each new case of malaria by active surveillance. Methods. In a randomized, open-label, comparative malaria treatment trial, 72 adults and 50 children received chloroquine for each incident case of malaria, and 74 adults and 47 children received mefloquine. Results. Among 975 primary treatment courses, the cumulative 28-day curative efficacies were 26% and 82% for chloroquine against Plasmodium falciparum malaria and Plasmodium vivax malaria, respectively. Mefloquine cure rates were far superior (96% against P. falciparum malaria and 99.6% against P. vivax malaria). Conclusions. Mefloquine is a useful alternative treatment for P. vivax malaria and P. falciparum malaria in areas such as Papua, where chloroquine is still recommended as the first-line therapeutic agent