Superconductivity in zigzag CuO chains

Superconductivity has recently been discovered in Pr$_{2}$Ba$_{4}$Cu$_{7}$O$_{15-\delta}$ with a maximum $T_c$ of about 15K. Since the CuO planes in this material are believed to be insulating, it has been proposed that the superconductivity occurs in the double (or zigzag) CuO chain layer. On phenomenological grounds, we propose a theoretical interpretation of the experimental results in terms of a new phase for the zigzag chain, labelled by C$_1$S$_{3/2}$. This phase has a gap for some of the relative spin and charge modes but no total spin gap, and can have a divergent superconducting susceptibility for repulsive interactions. A microscopic model for the zigzag CuO chain is proposed, and on the basis of density matrix renormalization group (DMRG) and bosonization studies of this model, we adduce evidence that supports our proposal.Comment: 10 pages, 5 figures; Journal-ref. adde

Modulation of Tumor Tolerance in Primary Central Nervous System Malignancies

Central nervous system tumors take advantage of the unique immunology of the CNS and develop exquisitely complex stromal networks that promote growth despite the presence of antigen-presenting cells and tumor-infiltrating lymphocytes. It is precisely this immunological paradox that is essential to the survival of the tumor. We review the evidence for functional CNS immune privilege and the impact it has on tumor tolerance. In this paper, we place an emphasis on the role of tumor-infiltrating myeloid cells in maintaining stromal and vascular quiescence, and we underscore the importance of indoleamine 2,3-dioxygenase activity as a myeloid-driven tumor tolerance mechanism. Much remains to be discovered regarding the tolerogenic mechanisms by which CNS tumors avoid immune clearance. Thus, it is an open question whether tumor tolerance in the brain is fundamentally different from that of peripheral sites of tumorigenesis or whether it simply stands as a particularly strong example of such tolerance

An investigation of temperature-sensing textiles for temperature monitoring during sub-maximal cycling trials

Temperature sensing textiles have been proposed for a variety of applications including health monitoring and sports. Skin temperature (Tsk) measurements are an important parameter in performance sports and can be used to better understand thermoregulation during exercise. Currently, most Tsk measurements are taken using skin mounted thermistors, which can be uncomfortable to the wearer, or thermal imaging, which can be difficult to implement and analyse. This work investigates the feasibility of using textile temperature sensing electronic yarns (E-yarns) to measure human skin temperature during sub maximal cycling trials. E-yarns were attached to commercially available cycling suits and measurements were recorded using both the E-yarns and the skin mounted thermistors at rest and during sub maximal cycling. Temperature readings were compared between the two temperature sensing methodologies to determine the viability of using the temperature sensing E-yarns for this application. Differences in the Tsk measurements as high as 5.9 °C between the E-yarns and skin mounted thermistors for participants at rest have been shown. This work has also identified that a build-up of sweat significantly altered the Tsk recorded by the E-yarns in some cases. Further experiments explored the effect of saline solutions (simulating sweat) on the response of the temperature sensing E-yarns. This work has highlighted boundary conditions for taking point Tsk measurement using electronic textiles

Using Hierarchical Data Mining to Characterize Performance of Wireless System Configurations

This paper presents a statistical framework for assessing wireless systems performance using hierarchical data mining techniques. We consider WCDMA (wideband code division multiple access) systems with two-branch STTD (space time transmit diversity) and 1/2 rate convolutional coding (forward error correction codes). Monte Carlo simulation estimates the bit error probability (BEP) of the system across a wide range of signal-to-noise ratios (SNRs). A performance database of simulation runs is collected over a targeted space of system configurations. This database is then mined to obtain regions of the configuration space that exhibit acceptable average performance. The shape of the mined regions illustrates the joint influence of configuration parameters on system performance. The role of data mining in this application is to provide explainable and statistically valid design conclusions. The research issue is to define statistically meaningful aggregation of data in a manner that permits efficient and effective data mining algorithms. We achieve a good compromise between these goals and help establish the applicability of data mining for characterizing wireless systems performance

Post-Outburst Observations of V1647 Ori: Detection of a Brief Warm, Molecular Outflow

We present new observations of the fundamental ro-vibrational CO spectrum of V1647 Ori, the young star whose recent outburst illuminated McNeil's Nebula. Previous spectra, acquired during outburst in 2004 February and July, had shown the CO emission lines to be broad and centrally peaked-similar to the CO spectrum of a typical classical T Tauri star. In this paper, we present CO spectra acquired shortly after the luminosity of the source returned to its pre-outburst level (2006 February) and roughly one year later (2006 December and 2007 February). The spectrum taken in 2006 February revealed blue-shifted CO absorption lines superimposed on the previously observed CO emission lines. The projected velocity, column density, and temperature of this outflowing gas was 30 km/s, 3^{+2}_{-1}E18 cm^{-2$, and 700^{+300}_{-100} K, respectively. The absorption lines were not observed in the 2006 December and 2007 February data, and so their strengths must have decreased in the interim by a factor of 9 or more. We discuss three mechanisms that could give rise to this unusual outflow.Comment: 14 pages, 2 figures, accepted for publication in ApJ

BSML: A Binding Schema Markup Language for Data Interchange in Problem Solving Environments (PSEs)

We describe a binding schema markup language (BSML) for describing data interchange between scientific codes. Such a facility is an important constituent of scientific problem solving environments (PSEs). BSML is designed to integrate with a PSE or application composition system that views model specification and execution as a problem of managing semistructured data. The data interchange problem is addressed by three techniques for processing semistructured data: validation, binding, and conversion. We present BSML and describe its application to a PSE for wireless communications system design

A systematic review of internet-based worksite wellness approaches for cardiovascular disease risk management: outcomes, challenges & opportunities.

ContextThe internet is gaining popularity as a means of delivering employee-based cardiovascular (CV) wellness interventions though little is known about the cardiovascular health outcomes of these programs. In this review, we examined the effectiveness of internet-based employee cardiovascular wellness and prevention programs.Evidence acquisitionWe conducted a systematic review by searching PubMed, Web of Science and Cochrane library for all published studies on internet-based programs aimed at improving CV health among employees up to November 2012. We grouped the outcomes according to the American Heart Association (AHA) indicators of cardiovascular wellbeing--weight, BP, lipids, smoking, physical activity, diet, and blood glucose.Evidence synthesisA total of 18 randomized trials and 11 follow-up studies met our inclusion/exclusion criteria. Follow-up duration ranged from 6-24 months. There were significant differences in intervention types and number of components in each intervention. Modest improvements were observed in more than half of the studies with weight related outcomes while no improvement was seen in virtually all the studies with physical activity outcome. In general, internet-based programs were more successful if the interventions also included some physical contact and environmental modification, and if they were targeted at specific disease entities such as hypertension. Only a few of the studies were conducted in persons at-risk for CVD, none in blue-collar workers or low-income earners.ConclusionInternet based programs hold promise for improving the cardiovascular wellness among employees however much work is required to fully understand its utility and long term impact especially in special/at-risk populations

Structural Insights into the Mechanisms of Antibody-Mediated Neutralization of Flavivirus Infection: Implications for Vaccine Development

Flaviviruses are a group of small RNA viruses that cause severe disease in humans worldwide and are the target of several vaccine development programs. A primary goal of these efforts is to elicit a protective humoral response directed against the envelope proteins arrayed on the surface of the flavivirus virion. Advances in the structural biology of these viruses has catalyzed rapid progress toward understanding the complexity of the flavivirus immunogen and the molecular basis of antibody-mediated neutralization. These insights have identified factors that govern the potency of neutralizing antibodies and will inform the design and evaluation of novel vaccines