Magnetic anisotropy study of ion-beam synthesized cobalt nanocrystals

The magnetic properties of Co nanocrystals in crystalline Al2 O3 and amorphous Si O2 are investigated. In contrast to the Si O2 matrix, the Al2 O3 matrix provides higher magnetic anisotropy and coercive field for Co nanocrystals. Using x-ray photoemission spectroscopy, it is found that a Co Al2 O4 layer forms in Co implanted region. Transmission electron microscopy shows that this Co Al2 O4 layer is grown epitaxially around Co nanocrystals. The higher coercive field of the Co nanocrystals in Al2 O3 is attributed to the presence of antiferromagnetic Co Al2 O4 layers. © 2006 American Institute of Physics

Antiferromagnetic ordering of divalent Eu in EuCu2Si2 single crystals

We report the synthesis, from an indium flux, of single crystals of EuCu2Si2. In contrast to previous studies of polycrystalline samples in which intermediate-valent behavior for Eu is reported, we find that in single crystals of EuCu2Si2 the behavior of Eu is divalent, including the presence of antiferromagnetic order at 10 K. The origins of these variations in ground-state properties are discussed in terms of effective chemical pressure and local changes in chemical environment.63

Cerium Heavy-Fermion Compounds Near Their T=0 Magnetic-Non-Magnetic Boundary.

Measurements of the temperature-dependent specific heat and thermal expansion coefficient near a T=0 magnetic-nonmagnetic boundary, accessed in CeRh2Si2 by application of pressure and in CeRh2-xRuxSi2 at ambient pressure by chemical substitution, emphasize the role of disorder in producing non-Fermi-liquid behavior. Interestingly, superconductivity also develops near this boundary in some crystallographically-ordered Ce-based heavy-fermion compounds. [CeRh2-xRuxSi2, specific heat, thermal expansion, susceptibility, non-Fermi-liquid]. © 1998, The Japan Society of High Pressure Science and Technology. All rights reserved

Evolution of the magnetic properties and magnetic structures along the RmMIn3m+2 (R = Ce, Nd, Gd, Tb; M = Rh, Ir; and m=1,2) series of intermetallic compounds

We discuss the evolution of the magnetic properties and magnetic structures along the series of intermetallic compounds RmMIn3m+2 (R=Ce, Nd, Gd, Tb; M=Rh, Ir; and m=1,2). The m=1,2 are, respectively, the single layer and bilayer tetragonal derivatives of their cubic RIn3 relatives. Using a mean field model including an isotropic first-neighbors Ruderman-Kittel-Kasuya-Yoshida interaction (K) and the tetragonal crystalline electrical field (CEF), we demonstrated that, for realistic values of K and CEF parameters, one can qualitatively describe the direction of the ordered moments and the behavior of the ordering temperature for these series. The particular case, where the rare-earth ordered moments lie in the ab plane or are tilted from the c axis and T-N can be reduced by tuning the CEF parameters, revealed an interesting kind of frustration that may be relevant to the physical properties of complex classes of materials such as the RmMIn3m+2 (M=Rh, Ir, and Co; m=1,2) heavy-fermion superconductors. (C) 2006 American Institute of Physics.99

'Friends as enemies': A sociological analysis of the relationship among touring professional golfers

This paper examines the relationship among male touring professional golfers from a figurational sociological standpoint. The paper is based on 20 interviews from players with experience playing at various levels on the EPGA professional tours and a level ‘above’ that. The results indicate a workplace culture where many begin to adopt the attitudes and behaviors that encourage the development of networks of temporary ‘we-group’ alliances. The ‘touring’ aspects of professional golf means many players strive to forge these alliances to help reduce feelings of loneliness, isolation, and homesickness while away for long periods of time. Such stresses are intensified given the globalization of sport generally and the associated increases in labor market migration that has become commonplace. The urge to develop friendship networks constrains players to behave in a manner expected of them rather than in a way that reflects their actual emotions, such as maintaining a positive attitude during difficult times like spells of poor performances and time away from their families. The relationships among players on tour is, however, non-permanent and/or partially changeable. Players are ‘friends’, characterized by togetherness and camaraderie, while, at the same, showing evidence of tensions and conflict as they are ultimately in direct competition with each other for a share of the overall prize money. Key words: professional golf, workplace relations, sport labor migration, figurational sociology, friendship network

Non-invasive cardiac assessment in high risk patients (The GROUND study): rationale, objectives and design of a multi-center randomized controlled clinical trial

Background: Peripheral arterial disease (PAD) is a common disease associated with a considerably increased risk of future cardiovascular events and most of these patients will die from coronary artery disease (CAD). Screening for silent CAD has become an option with recent non-invasive developments in CT (computed tomography)-angiography and MR (magnetic resonance) stress testing. Screening in combination with more aggressive treatment may improve prognosis. Therefore we propose to study whether a cardiac imaging algorithm, using non-invasive imaging techniques followed by treatment will reduce the risk of cardiovascular disease in PAD patients free from cardiac symptoms. Design: The GROUND study is designed as a prospective, multi-center, randomized clinical trial. Patients with peripheral arterial disease, but without symptomatic cardiac disease will be asked to participate. All patients receive a proper risk factor management before randomization. Half of the recruited patients will enter the 'control group' and only undergo CT calcium scoring. The other half of the recruited patients (index group) will undergo the non invasive cardiac imaging algorithm followed by evidence-based treatment. First, patients are submitted to CT calcium scoring and CT angiography. Patients with a left main (or equivalent) coronary artery stenosis of > 50% on CT will be referred to a cardiologist without further imaging. All other patients in this group will undergo dobutamine stress magnetic resonance (DSMR) testing. Patients with a DSMR positive for ischemia will also be referred to a cardiologist. These patients are candidates for conventional coronary angiography and cardiac interventions (coronary artery bypass grafting (CABG) or percutaneous cardiac interventions (PCI)), if indicated. All participants of the trial will enter a 5 year follow up period for the occurrence of cardiovascular events. Sequential interim analysis will take place. Based on sample size calculations about 1200 patients are needed to detect a 24% reduction in primary outcome. Implications: The GROUND study will provide insight into the question whether non-invasive cardiac imaging reduces the risk of cardiovascular events in patients with peripheral arterial disease, but without symptoms of coronary artery disease. Trial registration: Clinicaltrials.gov NCT0018911

Expression of a malarial Hsp70 improves defects in chaperone-dependent activities in ssa1 mutant yeast

Plasmodium falciparum causes the most virulent form of malaria and encodes a large number of molecular chaperones. Because the parasite encounters radically different environments during its lifecycle, many members of this chaperone ensemble may be essential for P. falciparum survival. Therefore, Plasmodium chaperones represent novel therapeutic targets, but to establish the mechanism of action of any developed therapeutics, it is critical to ascertain the functions of these chaperones. To this end, we report the development of a yeast expression system for PfHsp70-1, a P. falciparum cytoplasmic chaperone. We found that PfHsp70-1 repairs mutant growth phenotypes in yeast strains lacking the two primary cytosolic Hsp70s, SSA1 and SSA2, and in strains harboring a temperature sensitive SSA1 allele. PfHsp70-1 also supported chaperone-dependent processes such as protein translocation and ER associated degradation, and ameliorated the toxic effects of oxidative stress. By introducing engineered forms of PfHsp70-1 into the mutant strains, we discovered that rescue requires PfHsp70-1 ATPase activity. Together, we conclude that yeast can be co-opted to rapidly uncover specific cellular activities mediated by malarial chaperones. © 2011 Bell et al

Determinants of job satisfaction: a European comparison of self-employed and paid employees

The job satisfaction of self-employed and paid-employed workers is analyzed using the European Community Household Panel for the EU-15 covering the years 1994-2001. We distinguish between two types of job satisfaction: job satisfaction in terms of type of work and job satisfaction in terms of job security. Findings from our generalized ordered logit regressions indicate that self-employed individuals as compared to paid employees are more likely to be satisfied with their present jobs in terms of type of work and less likely to be satisfied in terms of job security. The findings also provide many insights into the determinants of the two types of job satisfaction for both self-employed and paid-employed workers

T2-weighted cardiovascular magnetic resonance in acute cardiac disease

Cardiovascular magnetic resonance (CMR) using T2-weighted sequences can visualize myocardial edema. When compared to previous protocols, newer pulse sequences with substantially improved image quality have increased its clinical utility. The assessment of myocardial edema provides useful incremental diagnostic and prognostic information in a variety of clinical settings associated with acute myocardial injury. In patients with acute chest pain, T2-weighted CMR is able to identify acute or recent myocardial ischemic injury and has been employed to distinguish acute coronary syndrome (ACS) from non-ACS as well as acute from chronic myocardial infarction