Modeling Phase-resolved Observations of the Surfaces of Magnetic Neutron Stars

Recent observations by XMM-Newton detected rotational pulsations in the total brightness and spectrum of several neutron stars. To properly interpret the data, accurate modeling of neutron star emission is necessary. Detailed analysis of the shape and strength of the rotational variations allows a measurement of the surface composition and magnetic field, as well as constrains the nuclear equation of state. We discuss our models of the spectra and light curves of two of the most observed neutron stars, RX J1856.5-3754 and 1E 1207.4-5209, and discuss some implications of our results and the direction of future work.Comment: 5 pages, 6 figures; Proceedings of "40 Years of Pulsars", eds. C. Bassa, Z. Wang, A. Cumming, V. Kaspi, AIP, submitte

Isolation of Entomopathogenic Nematodes (Steinernematidae and Heterorhabditidae) from Korea

A survey for entomopathogenic nematodes was conducted throughout the nine provinces and within three city limits in the Republic of Korea during the summers of 1990 and 1991. Six of the nine provinces and one of the three cities were positive for entomopathogenic nematodes. Out of the total 499 soil samples, 23 (4.6%) were positive for entomopathogenic nematodes with 19 (3.8%) containing Steinernema and 4 (0.8%) containing Heterorhabditis. Heterorhabditis bacteriophora and three distinct groups of Steinernema species were identified. One of the three steinernematid groups was identified as S. carpocapsae based on cross breeding studies. Positive sample sites in each habitat included 15 of the 415 (3.6%) from forests including regrowth areas with shrubs, 1 of the 27 (3.7%) from turfgrass including golf courses and parks, 3 of the 24 (12.5%) from agricultural fields, 2 of the 16 (12.5%) along riparian areas, and 2 of the 17 (11.8%) near the seashore. We advocate that more surveys be conducted for entomopathogenic nematodes before commercial sources of nematodes are widely applied which may obscure the naturally-occurring nematodes.Centro de Estudios Parasitológicos y de Vectore

Fluoroquinolone Efficacy against Tuberculosis Is Driven by Penetration into Lesions and Activity against Resident Bacterial Populations.

Fluoroquinolones represent the pillar of multidrug-resistant tuberculosis (MDR-TB) treatment, with moxifloxacin, levofloxacin, or gatifloxacin being prescribed to MDR-TB patients. Recently, several clinical trials of "universal" drug regimens, aiming to treat drug-susceptible and drug-resistant TB, have included a fluoroquinolone. In the absence of clinical data comparing their side-by-side efficacies in controlled MDR-TB trials, a pharmacological rationale is needed to guide the selection of the most efficacious fluoroquinolone. The present studies were designed to test the hypothesis that fluoroquinolone concentrations (pharmacokinetics) and activity (pharmacodynamics) at the site of infection are better predictors of efficacy than the plasma concentrations and potency measured in standard growth inhibition assays and are better suited to determinations of whether one of the fluoroquinolones outperforms the others in rabbits with active TB. We first measured the penetration of these fluoroquinolones in lung lesion compartments, and their potency against bacterial populations that reside in each compartment, to compute lesion-centric pharmacokinetic-pharmacodynamic (PK/PD) parameters. PK modeling methods were used to quantify drug penetration from plasma to tissues at human-equivalent doses. On the basis of these metrics, moxifloxacin emerged with a clear advantage, whereas plasma-based PK/PD favored levofloxacin (the ranges of the plasma AUC/MIC ratio [i.e., the area under the concentration-time curve over 24 h in the steady state divided by the MIC] are 46 to 86 for moxifloxacin and 74 to 258 for levofloxacin). A comparative efficacy trial in the rabbit model of active TB demonstrated the superiority of moxifloxacin in reducing bacterial burden at the lesion level and in sterilizing cellular and necrotic lesions. Collectively, these results show that PK/PD data obtained at the site of infection represent an adequate predictor of drug efficacy against TB and constitute the baseline required to explore synergies, antagonism, and drug-drug interactions in fluoroquinolone-containing regimens

Isolation of Entomopathogenic Nematodes (Steinernematidae and Heterorhabditidae) from Korea

A survey for entomopathogenic nematodes was conducted throughout the nine provinces and within three city limits in the Republic of Korea during the summers of 1990 and 1991. Six of the nine provinces and one of the three cities were positive for entomopathogenic nematodes. Out of the total 499 soil samples, 23 (4.6%) were positive for entomopathogenic nematodes with 19 (3.8%) containing Steinernema and 4 (0.8%) containing Heterorhabditis. Heterorhabditis bacteriophora and three distinct groups of Steinernema species were identified. One of the three steinernematid groups was identified as S. carpocapsae based on cross breeding studies. Positive sample sites in each habitat included 15 of the 415 (3.6%) from forests including regrowth areas with shrubs, 1 of the 27 (3.7%) from turfgrass including golf courses and parks, 3 of the 24 (12.5%) from agricultural fields, 2 of the 16 (12.5%) along riparian areas, and 2 of the 17 (11.8%) near the seashore. We advocate that more surveys be conducted for entomopathogenic nematodes before commercial sources of nematodes are widely applied which may obscure the naturally-occurring nematodes.Centro de Estudios Parasitológicos y de Vectore

Optimal linear combination of poisson variables for multivariate statistical process control

In this paper we analyze the monitoring of p Poisson quality characteristics simultaneously, developing a new multivariate control chart based on the linear combination of the Poisson variables, the LCP control chart. The optimization of the coefficients of this linear combination (and control limit) for minimizing the out-of-control ARL is constrained by the desired in-control ARL. In order to facilitate the use of this new control chart the optimization is carried out employing user-friendly Windows© software, which also makes a comparison of performance between this chart and other schemes based on monitoring a set of Poisson variables; namely a control chart on the sum of the variables (MP chart), a control chart on their maximum (MX chart) and an optimized set of univariate Poisson charts (Multiple scheme). The LCP control chart shows very good performance. First, the desired in-control ARL (ARL0) is perfectly matched because the linear combination of Poisson variables is not constrained to integer values, which is an advantage over the rest of charts, which cannot in general match the required ARL0 value. Second, in the vast majority of cases this scheme signals process shifts faster than the rest of the charts.This work has been supported by the Ministry of Education and Science of Spain, research project number DPI2009-09925, the CNPq (the Brazilian Council for Scientific and Technological Development), project numbers 302326/2008-1 and 473706/2010-5, and SENESCYT-Ecuador (National Secretary of Higher Education, Science, Technology and Innovation of Equator). The authors are grateful to the referees for their comments, which led to significant improvement of the paper.Kahn Epprecht, E.; Aparisi García, FJ.; García Bustos, SL. (2013). Optimal linear combination of poisson variables for multivariate statistical process control. Computers and Operations Research. 40(12):3021-3032. https://doi.org/10.1016/j.cor.2013.07.007S30213032401

Improving Utilization of SGLT2 Inhibitors in the Inpatient Setting

SGLT2 inhibitors have been shown to have a significant benefit for patients with DM2 or CAD (DAPA-HF, Emperor-reduced) The usage of these medications are low compared to other Goal Directed Medical Therapy. There are multiple contributing factors as to why these medications are underutilized Our aim is to assess barriers against prescription of SGLT2-i at the time of discharge from TJUH and to increase utilization after placement on formulary

Modelling mid-Z element atmospheres for strongly-magnetized neutron stars

We construct models for strongly-magnetized neutron star atmospheres composed of mid-Z elements (carbon, oxygen and neon) with magnetic fields B=10^{12}-10^{13} G and effective temperatures Teff=(1-5)*10^6 K; this is done by first addressing the physics relevant to strongly-magnetized plasmas and calculating the equation of state and polarization-dependent opacities. We then obtain the atmosphere structure and spectrum by solving the radiative transfer equations in hydrostatic and radiative equilibrium. In contrast to hydrogen opacities at the relevant temperatures, mid-Z element opacities are dominated by numerous bound-bound and bound-free transitions. Consequently, temperature profiles are closer to grey profiles, and photosphere densities are lower than in the hydrogen case. Mid-Z element atmosphere spectra are significantly softer than hydrogen atmosphere spectra and show numerous absorption lines and edges. The atmosphere spectra depend strongly on surface composition and magnetic field but weakly on surface gravity. Absorption lines are primarily broadened by motional Stark effects and the (unknown) surface magnetic field distribution. Given the multiple absorption features observed from several isolated neutron stars, it is possible to determine, with existing X-ray data, the surface composition, magnetic field, temperature, and gravitational redshift; we present qualitative comparisons between our model spectra and the neutron stars 1E1207.4-5209 and RX J1605.3+3249. Future high-resolution X-ray missions such as Constellation-X will measure the gravitational redshift with high accuracy by resolving narrow absorption features, and when combined with radius measurements, it will be possible to uniquely determine the mass and radius of isolated neutron stars. (Abridged)Comment: 16 pages, 22 figures, accepted for publication in MNRA

Wholesale price contracts for reliable supply

Firms can enhance the reliability of their supply through process improvement and overproduction. In decentralized supply chains, however, these mitigating actions may be the supplier's responsibility yet are often not contractible. We show that wholesale price contracts, despite their simplicity, can perform well in inducing reliable supply, and we identify when and why they perform well. This could explain the widespread use of wholesale price contracts in business settings with unreliable supply. In particular, we investigate how the performance of wholesale price contracts depends on the interplay between the nature of supply risk and the type of procurement process. Supply risk is classified as random capacity when events such as labor strike disrupt the firm's ability to produce, or as random yield when manufacturing defects result in yield losses. The procurement process is classified as control when the buyer determines the production quantity, or as delegation when instead the supplier does. Analyzing the four possible combinations, we find that for random capacity, irrespective of the procurement process type, contract performance monotonically increases with the supplier's bargaining power; thus, wholesale price contracts perform well when the supplier is powerful. However, this monotonic trend is reversed for random yield with control: in that case, wholesale price contracts perform well when instead the buyer is powerful. For random yield with delegation, wholesale price contracts perform well when either party is powerful