Nanocrystalline Zr3Al Made through Amorphization by Repeated Cold Rolling and Followed by Crystallization

The intermetallic compound Zr3Al is severely deformed by the method of repeated cold rolling. By X-ray diffraction it is shown that this leads to amorphization. TEM investigations reveal that a homogeneously distributed debris of very small nanocrystals is present in the amorphous matrix that is not resolved by X-ray diffraction. After heating to 773 K, the crystallization of the amorphous structure leads to a fully nanocrystalline structure of small grains (10 - 20 nm in diameter) of the non-equilibrium Zr2Al phase. It is concluded that the debris retained in the amorphous phase acts as nuclei. After heating to 973 K the grains grow to about 100 nm in diameter and the compound Zr3Al starts to form, that is corresponding to the alloy composition

Surface and interface study of pulsed-laser-deposited off-stoichiometric NiMnSb thin films on Si(100) substrate

We report a detailed study of surface and interface properties of pulsed-laser deposited NiMnSb films on Si (100) substrate as a function of film thickness. As the thickness of films is reduced below 35 nm formation of a porous layer is observed. Porosity in this layer increases with decrease in NiMnSb film thickness. These morphological changes of the ultra thin films are reflected in the interesting transport and magnetic properties of these films. On the other hand, there are no influences of compositional in-homogeneity and surface/interface roughness on the magnetic and transport properties of the films.Comment: 13 pages, 7 figures, Submitted to Phys. Rev.

Quality Control of Motor Unit Number Index (MUNIX) Measurements in 6 Muscles in a Single-Subject “Round-Robin” Setup

Background Motor Unit Number Index (MUNIX) is a neurophysiological measure that provides an index of the number of lower motor neurons in a muscle. Its performance across centres in healthy subjects and patients with Amyotrophic Lateral Sclerosis (ALS) has been established, but inter-rater variability between multiple raters in one single subject has not been investigated. Objective To assess reliability in a set of 6 muscles in a single subject among 12 examiners (6 experienced with MUNIX, 6 less experienced) and to determine variables associated with variability of measurements. Methods Twelve raters applied MUNIX in six different muscles (abductor pollicis brevis (APB), abductor digiti minimi (ADM), biceps brachii (BB), tibialis anterior (TA), extensor dig. brevis (EDB), abductor hallucis (AH)) twice in one single volunteer on consecutive days. All raters visited at least one training course prior to measurements. Intra- and inter-rater variability as determined by the coefficient of variation (COV) between different raters and their levels of experience with MUNIX were compared. Results Mean intra-rater COV of MUNIX was 14.0% (±6.4) ranging from 5.8 (APB) to 30.3% (EDB). Mean inter-rater COV was 18.1 (±5.4) ranging from 8.0 (BB) to 31.7 (AH). No significant differences of variability between experienced and less experienced raters were detected. Conclusion We provide evidence that quality control for neurophysiological methods can be performed with similar standards as in laboratory medicine. Intra- and inter-rater variability of MUNIX is muscle-dependent and mainly below 20%. Experienced neurophysiologists can easily adopt MUNIX and adequate teaching ensures reliable utilization of this method

Optimization of Financial Transmission Right Portfolios Using Risk-Reward Analysis of Deregulated Power Systems

Financial Transmission Rights (FTR) is an investment that protects the market customers from price uncertainty in the case of transmission line congestion. Pennsylvania-New Jersey-Maryland Interconnection (PJM) allows bidding of FTR\u27s on various transmission paths. This thesis investigates quantitative methods for portfolio optimization to produce a risk-minimum portfolio of FTR\u27s to bid. A computer model based on Security-Constrained Unit Commitment Problem and Risk-Reward Analysis is developed to simulate various operating conditions of a power system and predict the variations of power flows and corresponding electricity prices. It offers guidelines about the bidding cost and the amount of megawatts to bid for each transmission path, in order to obtain a certain profit with the corresponding minimum risk. The method for calculating the risk and reward is Markowitz Mean-Variance Analysis. The computer model also includes the LMP determination for which a MATLAB code has been developed. The model is tested on a 6-bus power system

Modulation of antigen-specific T-cells as immune therapy for chronic infectious diseases and cancer

Copyright: © 2014 Li, Symonds, Miao, Sanderson and Wang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.This article has been made available through the Brunel Open Access Publishing Fund.T-cell responses are induced by antigen presenting cells (APC) and signals from the microenvironment. Antigen persistence and inflammatory microenvironments in chronic infections and cancer can induce a tolerant state in T-cells resulting in hyporesponsiveness, loss of effector function, and weak biochemical signaling patterns in response to antigen stimulation. Although the mechanisms of T-cell tolerance induced in chronic infection and cancer may differ from those involved in tolerance to self-antigen, the impaired proliferation and production of IL-2 in response to antigen stimulation are hallmarks of all tolerant T cells. In this review, we will summarize the evidence that the immune responses change from non-self to “self”-like in chronic infection and cancer, and will provide an overview of strategies for re-balancing the immune response of antigen-specific T cells in chronic infection and cancer without affecting the homeostasis of the immune system.Arthritis Research UK and Medical Research Council UK

Effects of Aging on Genioglossus Motor Units in Humans

The genioglossus is a major upper airway dilator muscle thought to be important in obstructive sleep apnea pathogenesis. Aging is a risk factor for obstructive sleep apnea although the mechanisms are unclear and the effects of aging on motor unit remodeled in the genioglossus remains unknown. To assess possible changes associated with aging we compared quantitative parameters related to motor unit potential morphology derived from EMG signals in a sample of older (n = 11; >55 years) versus younger (n = 29; <55 years) adults. All data were recorded during quiet breathing with the subjects awake. Diagnostic sleep studies (Apnea Hypopnea Index) confirmed the presence or absence of obstructive sleep apnea. Genioglossus EMG signals were analyzed offline by automated software (DQEMG), which estimated a MUP template from each extracted motor unit potential train (MUPT) for both the selective concentric needle and concentric needle macro (CNMACRO) recorded EMG signals. 2074 MUPTs from 40 subjects (mean±95% CI; older AHI 19.6±9.9 events/hr versus younger AHI 30.1±6.1 events/hr) were extracted. MUPs detected in older adults were 32% longer in duration (14.7±0.5 ms versus 11.1±0.2 ms; P = 0.05), with similar amplitudes (395.2±25.1 µV versus 394.6±13.7 µV). Amplitudes of CNMACRO MUPs detected in older adults were larger by 22% (62.7±6.5 µV versus 51.3±3.0 µV; P<0.05), with areas 24% larger (160.6±18.6 µV.ms versus 130.0±7.4 µV.ms; P<0.05) than those detected in younger adults. These results confirm that remodeled motor units are present in the genioglossus muscle of individuals above 55 years, which may have implications for OSA pathogenesis and aging related upper airway collapsibility

Optimization of Financial Transmission Right Portfolios Using Risk-Reward Analysis of Deregulated Power Systems

Financial Transmission Rights (FTR) is an investment that protects the market customers from price uncertainty in the case of transmission line congestion. Pennsylvania-New Jersey-Maryland Interconnection (PJM) allows bidding of FTR\u27s on various transmission paths. This thesis investigates quantitative methods for portfolio optimization to produce a risk-minimum portfolio of FTR\u27s to bid. A computer model based on Security-Constrained Unit Commitment Problem and Risk-Reward Analysis is developed to simulate various operating conditions of a power system and predict the variations of power flows and corresponding electricity prices. It offers guidelines about the bidding cost and the amount of megawatts to bid for each transmission path, in order to obtain a certain profit with the corresponding minimum risk. The method for calculating the risk and reward is Markowitz Mean-Variance Analysis. The computer model also includes the LMP determination for which a MATLAB code has been developed. The model is tested on a 6-bus power system

Audio Retrieval Using Multiple Feature Vectors

Content Based Audio Retrieval system is very helpful to facilitate users to find the target audio materials. Audio signals are classified into speech, music, several types of environmental sounds and silence based on audio content analysis. The extracted audio features include temporal curves of the average zero-crossing rate, the spectral Centroid, the spectral flux, as well as spectral roll-off of these curves. In this dissertation we have used the four features for extracting the audio from the database, use of this multiple features increase the accuracy of the audio file which we are retrieving from the audio database

Examining the Knowledge Sharing and Uncivil Behavior of Envious Employees: An Affective Events Theory Perspective

Envy is deep-rooted within human nature and considered as a socially undesirable emotion. According to social science scholars, competitive situations are breeding grounds for various feelings of ill-will. Researchers have demonstrated that an organization\u27s systems and structure permit envy to exist and thrive even in the workplace. Within a workplace setting, various job-related scenarios such as positions held, promotions, projects assigned, job design, pay increases, and performance recognition can lead to envious feelings, which in turn, can have negative consequences. There are some organizations in which employees engage in close interactions on a regular basis and share a high degree of work- related interdependence. These situations offer frequent opportunities for comparisons with colleagues. Conceptual as well as empirical research on the topic of workplace envy has been very limited till date. As such, our study is an attempt to advance the understanding of the vital role envy may play in the organizational context. In this process, our study strives to extend the current theories on affective or emotional experiences by providing integrated model of workplace envy. Specifically, we examine the impact of leader member exchange (LMX) on envy. Also, the intriguing role of perceived co-worker similarity and equity sensitivity in the above relationship is explored. Furthermore, we investigate the relationship of envy with employees’ knowledge sharing, uncivil behaviors, and intention to quit. Building on the Affective events theory, we argue that employees, who do not have a good relationship with their leaders (low LMX), will feel envious; and will be likely to restrict their knowledge sharing and engage in uncivil behaviors towards, or even, intend to quit the organization. Hierarchical regression analysis was used to test the hypotheses on a sample of 204 software engineers working in different multinational companies. The results provide support to most of the suggested hypotheses. Our study contributes to the growing body of literature on negative emotions in the workplace. In addition, implications of this study call for the need to manage employee emotions in the workplace. Finally, future research avenues based on our results are discussed

Failure to expand the motor unit size to compensate for declining motor unit numbers distinguishes sarcopenic from non-sarcopenic older men

Key points: . The age‐related loss of muscle mass is related to the loss of innervating motor neurons and denervation of muscle fibres. . Not all denervated muscle fibres are degraded; some may be reinnervated by an adjacent surviving neuron, which expands the innervating motor unit proportional to the numbers of fibres rescued. . Enlarged motor units have larger motor unit potentials when measured using electrophysiological techniques. . We recorded much larger motor unit potentials in relatively healthy older men compared to young men, but the older men with the smallest muscles (sarcopenia) had smaller motor unit potentials than healthy older men. . These findings suggest that healthy older men reinnervate large numbers of muscle fibres to compensate for declining motor neuron numbers, but a failure to do so contributes to muscle loss in sarcopenic men. Abstract: Sarcopenia results from the progressive loss of skeletal muscle mass and reduced function in older age. It is likely to be associated with the well‐documented reduction of motor unit numbers innervating limb muscles and the increase in size of surviving motor units via reinnervation of denervated fibres. However, no evidence exists to confirm the extent of motor unit remodelling in sarcopenic individuals. The aim of the present study was to compare motor unit size and number between young (n = 48), non‐sarcopenic old (n = 13), pre‐sarcopenic (n = 53) and sarcopenic (n = 29) men. Motor unit potentials (MUPs) were isolated from intramuscular and surface EMG recordings. The motor unit numbers were reduced in all groups of old compared with young men (all P < 0.001). MUPs were higher in non‐sarcopenic and pre‐sarcopenic men compared with young men (P = 0.039 and 0.001 respectively), but not in the vastus lateralis of sarcopenic old (P = 0.485). The results suggest that extensive motor unit remodelling occurs relatively early during ageing, exceeds the loss of muscle mass and precedes sarcopenia. Reinnervation of denervated muscle fibres probably expands the motor unit size in the non‐sarcopenic and pre‐sarcopenic old, but not in the sarcopenic old. These findings suggest that a failure to expand the motor unit size distinguishes sarcopenic from pre‐sarcopenic muscles