Bounded and unitary elements in pro-C^*-algebras

A pro-C^*-algebra is a (projective) limit of C^*-algebras in the category of topological *-algebras. From the perspective of non-commutative geometry, pro-C^*-algebras can be seen as non-commutative k-spaces. An element of a pro-C^*-algebra is bounded if there is a uniform bound for the norm of its images under any continuous *-homomorphism into a C^*-algebra. The *-subalgebra consisting of the bounded elements turns out to be a C^*-algebra. In this paper, we investigate pro-C^*-algebras from a categorical point of view. We study the functor (-)_b that assigns to a pro-C^*-algebra the C^*-algebra of its bounded elements, which is the dual of the Stone-\v{C}ech-compactification. We show that (-)_b is a coreflector, and it preserves exact sequences. A generalization of the Gelfand-duality for commutative unital pro-C^*-algebras is also presented.Comment: v2 (accepted

Readmissions Within 48 Hours of Discharge: Reasons, Risk Factors, and Potential Improvements.

Hospital readmission rate is an important quality metric and has been recognized as a key measure of hospital value-based purchasing programs. This study aimed to assess the risk factors for hospital readmission with a focus on potentially preventable early readmissions within 48 hours of discharge. This is a retrospective cohort study. This study was conducted at a tertiary academic facility with a standardized enhanced recovery pathway. Consecutive patients undergoing elective major colorectal resections between 2011 and 2016 were included. Univariable and multivariable risk factors for overall and early (<48 hours) readmissions were identified. Specific surgical and medical reasons for readmission were compared between early and late readmissions. In total, 526 of 4204 patients (12.5%) were readmitted within 30 days of discharge. Independent risk factors were ASA score (≥3; OR, 1.5; 95% CI, 1.1-2), excess perioperative weight gain (OR, 1.7; 95% CI, 1.3-2.3), ileostomy (OR, 1.4; 95% CI, 1-2), and transfusion (OR, 2; 95% CI, 1.4-3), or reoperation (OR, 11.4; 95% CI, 7.4-17.5) during the index stay. No potentially preventable risk factor for early readmission (128 patients, 24.3% of all readmissions, 3% of total cohort) was identified, and index hospital stay of ≤3 days was not associated with increased readmission (OR, 0.9; 95% CI, 0.7-1.2). Although ileus and small-bowel obstruction (early: 43.8% vs late: 15.5%, p < 0.001) were leading causes for early readmissions, deep infections (3.9% vs 16.3%, p < 0.001) and acute kidney injury (0% vs 5%, p = 0.006) were mainly observed during readmissions after 48 hours. Risk of underreporting due to loss of follow-up and the potential co-occurrence of complications were limitations of this study. Early hospital readmission was mainly due to ileus or bowel obstruction, whereas late readmissions were related to deep infections and acute kidney injury. A suspicious attitude toward potential ileus-related symptoms before discharge and dedicated education for ostomy patients are important. A short index hospital stay was not associated with increased readmission rates. See Video Abstract at http://links.lww.com/DCR/B237. REINGRESOS DENTRO DE LAS 48 HORAS POSTERIORES AL ALTA: RAZONES, FACTORES DE RIESGO Y POSIBLES MEJORAS: La tasa de reingreso hospitalario es una métrica de calidad importante y ha sido reconocida como una medida clave de los programas hospitalarios de compras basadas en el valor.Evaluar los factores de riesgo para el reingreso hospitalario con énfasis en reingresos tempranos potencialmente prevenibles dentro de las 48 horas posteriores al alta.Estudio de cohorte retrospectivo.Institución académica terciaria con programa de recuperación mejorada estandarizado.Pacientes consecutivos sometidos a resecciones colorrectales mayores electivas entre 2011 y 2016.Se identificaron factores de riesgo uni y multivariables para reingresos totales y tempranos (<48 horas). Se compararon razones médicas y quirúrgicas específicas para el reingreso entre reingresos tempranos y tardíos.En total, 526/4204 pacientes (12,5%) fueron readmitidos dentro de los 30 días posteriores al alta. Los factores de riesgo independientes fueron puntuación ASA (≥3, OR 1.5; IC 95% 1.1-2), aumento de peso perioperatorio excesivo (OR 1.7; IC 95% 1.3-2.3), ileostomía (OR 1.4, IC 95%: 1-2) y transfusión (OR 2, IC 95% 1.4-3) o reoperación (OR 11.4; IC 95% 7.4-17.5) durante la estadía índice. No se identificó ningún factor de riesgo potencialmente prevenible para el reingreso temprano (128 pacientes, 24.3% de todos los reingresos, 3% de la cohorte total), y la estadía hospitalaria índice de ≤ 3 días no se asoció con un aumento en el reingreso (OR 0.9; IC 95% 0.7-1.2) Mientras que el íleo / obstrucción del intestino delgado (temprano: 43.8% vs. tardío: 15.5%, p < 0.001) fueron las principales causas de reingresos tempranos, infecciones profundas (3.9% vs 16.3%, p < 0.001) y lesión renal aguda (0 vs 5%, p = 0.006) se observaron principalmente durante los reingresos después de 48 horas.Riesgo de subregistro debido a la pérdida en el seguimiento, posible co-ocurrencia de complicaciones.El reingreso hospitalario temprano se debió principalmente a íleo u obstrucción intestinal, mientras que los reingresos tardíos se relacionaron con infecciones profundas y lesión renal aguda. Es importante tener una actitud suspicaz hacia los posibles síntomas relacionados con el íleo antes del alta y una educación específica para los pacientes con ostomía. La estadía hospitalaria índice corta no se asoció con mayores tasas de reingreso. Consulte Video Resumen en http://links.lww.com/DCR/B237

The effect of dietary supplementation with n-3 polyunsaturated fatty acids on the synthesis of interleukin-1 and tumor necrosis factor by mononuclear cells

Contains fulltext : 4487.pdf (publisher's version ) (Open Access

Solving variational inequalities defined on a domain with infinitely many linear constraints

We study a variational inequality problem whose domain is defined by infinitely many linear inequalities. A discretization method and an analytic center based inexact cutting plane method are proposed. Under proper assumptions, the convergence results for both methods are given. We also provide numerical examples to illustrate the proposed method

The Primordial Inflation Explorer (PIXIE): A Nulling Polarimeter for Cosmic Microwave Background Observations

The Primordial Inflation Explorer (PIXIE) is an Explorer-class mission to measure the gravity-wave signature of primordial inflation through its distinctive imprint on the linear polarization of the cosmic microwave background. The instrument consists of a polarizing Michelson interferometer configured as a nulling polarimeter to measure the difference spectrum between orthogonal linear polarizations from two co-aligned beams. Either input can view the sky or a temperature-controlled absolute reference blackbody calibrator. PIXIE will map the absolute intensity and linear polarization (Stokes I, Q, and U parameters) over the full sky in 400 spectral channels spanning 2.5 decades in frequency from 30 GHz to 6 THz (1 cm to 50 um wavelength). Multi-moded optics provide background-limited sensitivity using only 4 detectors, while the highly symmetric design and multiple signal modulations provide robust rejection of potential systematic errors. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r < 10^{-3} at 5 standard deviations. The rich PIXIE data set will also constrain physical processes ranging from Big Bang cosmology to the nature of the first stars to physical conditions within the interstellar medium of the Galaxy.Comment: 37 pages including 17 figures. Submitted to the Journal of Cosmology and Astroparticle Physic

Radiative Flux and Forcing Parameterization Error in Aerosol-Free Clear Skies

This article reports on the accuracy in aerosol- and cloud-free conditions of the radiation parameterizations used in climate models. Accuracy is assessed relative to observationally validated reference models for fluxes under present-day conditions and forcing (flux changes) from quadrupled concentrations of carbon dioxide. Agreement among reference models is typically within 1 W/m2, while parameterized calculations are roughly half as accurate in the longwave and even less accurate, and more variable, in the shortwave. Absorption of shortwave radiation is underestimated by most parameterizations in the present day and has relatively large errors in forcing. Error in present-day conditions is essentially unrelated to error in forcing calculations. Recent revisions to parameterizations have reduced error in most cases. A dependence on atmospheric conditions, including integrated water vapor, means that global estimates of parameterization error relevant for the radiative forcing of climate change will require much more ambitious calculations

The Intentional Use of Service Recovery Strategies to Influence Consumer Emotion, Cognition and Behaviour

Service recovery strategies have been identified as a critical factor in the success of. service organizations. This study develops a conceptual frame work to investigate how specific service recovery strategies influence the emotional, cognitive and negative behavioural responses of . consumers., as well as how emotion and cognition influence negative behavior. Understanding the impact of specific service recovery strategies will allow service providers' to more deliberately and intentionally engage in strategies that result in positive organizational outcomes. This study was conducted using a 2 x 2 between-subjects quasi-experimental design. The results suggest that service recovery has a significant impact on emotion, cognition and negative behavior. Similarly, satisfaction, negative emotion and positive emotion all influence negative behavior but distributive justice has no effect

Oracle-based optimization applied to climate model calibration

In this paper, we show how oracle-based optimization can be effectively used for the calibration of an intermediate complexity climate model. In a fully developed example, we estimate the 12 principal parameters of the C-GOLDSTEIN climate model by using an oracle- based optimization tool, Proximal-ACCPM. The oracle is a procedure that finds, for each query point, a value for the goodness-of-fit function and an evaluation of its gradient. The difficulty in the model calibration problem stems from the need to undertake costly calculations for each simulation and also from the fact that the error function used to assess the goodness-of-fit is not convex. The method converges to a Fbest fit_ estimate over 10 times faster than a comparable test using the ensemble Kalman filter. The approach is simple to implement and potentially useful in calibrating computationally demanding models based on temporal integration (simulation), for which functional derivative information is not readily available

The Science of Sungrazers, Sunskirters, and Other Near-Sun Comets

This review addresses our current understanding of comets that venture close to the Sun, and are hence exposed to much more extreme conditions than comets that are typically studied from Earth. The extreme solar heating and plasma environments that these objects encounter change many aspects of their behaviour, thus yielding valuable information on both the comets themselves that complements other data we have on primitive solar system bodies, as well as on the near-solar environment which they traverse. We propose clear definitions for these comets: We use the term near-Sun comets to encompass all objects that pass sunward of the perihelion distance of planet Mercury (0.307 AU). Sunskirters are defined as objects that pass within 33 solar radii of the Sun’s centre, equal to half of Mercury’s perihelion distance, and the commonly-used phrase sungrazers to be objects that reach perihelion within 3.45 solar radii, i.e. the fluid Roche limit. Finally, comets with orbits that intersect the solar photosphere are termed sundivers. We summarize past studies of these objects, as well as the instruments and facilities used to study them, including space-based platforms that have led to a recent revolution in the quantity and quality of relevant observations. Relevant comet populations are described, including the Kreutz, Marsden, Kracht, and Meyer groups, near-Sun asteroids, and a brief discussion of their origins. The importance of light curves and the clues they provide on cometary composition are emphasized, together with what information has been gleaned about nucleus parameters, including the sizes and masses of objects and their families, and their tensile strengths. The physical processes occurring at these objects are considered in some detail, including the disruption of nuclei, sublimation, and ionisation, and we consider the mass, momentum, and energy loss of comets in the corona and those that venture to lower altitudes. The different components of comae and tails are described, including dust, neutral and ionised gases, their chemical reactions, and their contributions to the near-Sun environment. Comet-solar wind interactions are discussed, including the use of comets as probes of solar wind and coronal conditions in their vicinities. We address the relevance of work on comets near the Sun to similar objects orbiting other stars, and conclude with a discussion of future directions for the field and the planned ground- and space-based facilities that will allow us to address those science topics