The composite Hall effect of non-magnetic and magnetic bilayers

Abstract We verify, in Mn:Zn bilayers, that the Hall conductivity is averaged in a bilayer of non-magnetic or ferro-and paramagnetic materials, as previously reported, with thickness as a weighting factor, and also verify that this can lead to anomalously large Hall coefficients. We extend these results to Ni:Pd bilayers in which the ferromagnetic layer increases the effective Hall coefficient of the non-magnetic layer by a factor of I + x,. Finally, we discuss the implications of these results for earlier studies in rare earth films covered with thin palladium layers.

The Effects of Modulating eNOS Activity and Coupling on Leukocyte-endothelial Interactions in Rat Mesenteric Postcapillary Venules

Background: Leukocyte-endothelial interactions associated with vascular injury are attenuated by endothelial-derived nitric oxide (NO). Endothelial NO synthase (eNOS) in the presence of tetrahydrobiopterin (BH4) produces NO from L-arginine and is termed eNOS coupling. However, when the ratio of dihydrobiopterin (BH2) to BH4 is increased, eNOS becomes uncoupled and produces superoxide instead of NO. Protein kinase C epsilon (PKC ε) positively regulates eNOS activity. This study examined modulating eNOS activity and coupling by superfusing BH2 (100 μM) by itself, combined with PKC ε activator (10μM) or PKC ε inhibitor, or combined with BH4 (100μM) and PKC ε activator in rat mesenteric venules

Simple mechanism for a positive exchange bias

We argue that the interface coupling, responsible for the positive exchange bias (HE) observed in ferromagnetic/compensated antiferromagnetic (FM/AF) bilayers, favors an antiferromagnetic alignment. At low cooling field this coupling polarizes the AF spins close to the interface, which spin configuration persists after the sample is cooled below the Neel temperature. This pins the FM spins as in Bean's model and gives rise to a negative HE. When the cooling field increases, it eventually dominates and polarizes the AF spins in an opposite direction to the low field one. This results in a positive HE. The size of HE and the crossover cooling field are estimated. We explain why HE is mostly positive for an AF single crystal, and discuss the role of interface roughness on the magnitude of HE, and the quantum aspect of the interface coupling.Comment: 10 pages, 2 figures, to be published on May 1 issue of PR

In-plane magnetic reorientation in coupled ferro- and antiferromagnetic thin films

By studying coupled ferro- (FM) and antiferromagnetic (AFM) thin film systems, we obtain an in-plane magnetic reorientation as a function of temperature and FM film thickness. The interlayer exchange coupling causes a uniaxial anisotropy, which may compete with the intrinsic anisotropy of the FM film. Depending on the latter the total in-plane anisotropy of the FM film is either enhanced or reduced. Eventually a change of sign occurs, resulting in an in-plane magnetic reorientation between a collinear and an orthogonal magnetic arrangement of the two subsystems. A canted magnetic arrangement may occur, mediating between these two extremes. By measuring the anisotropy below and above the N\'eel temperature the interlayer exchange coupling can be determined. The calculations have been performed with a Heisenberg-like Hamiltonian by application of a two-spin mean-field theory.Comment: 4 pages, 4 figure

Feasibility and Comparative Effectiveness for the Delivery of the National Diabetes Prevention Program through Cooperative Extension in Rural Communities

The U.S. Cooperative Extension Service (CE) has potential to deliver the National Diabetes Prevention Program (NDPP) to rural residents with prediabetes. However, the CE remains underutilized for the delivery of NDPP. We compared the feasibility/effectiveness of the NDPP (0–6 mos.) delivered by CE personnel to rural residents with prediabetes using Zoom® (CE-Zoom®) or by our research staff using Facebook® (FB). Adults (n = 31, age ~55 years) were enrolled (CE-Zoom® n = 16, FB n = 15). Attendance did not differ significantly between groups (CE Zoom® = 69%, FB = 83%, p = 0.15). Participant retention was similar in the CE Zoom® (88%) and FB groups (87%). CE-Zoom® and FB® groups provided weekly, self-monitoring data for 83% and 84% of the 24 potential weeks, respectively. Six-month weight loss was not different between groups (CE-Zoom® = −5.99 ± 8.0 kg, −5.4%, FB = −1.68 ± 3.3 kg, −1.6% p = 0.13). Participants achieving ≥5% weight loss was greater in the CE-Zoom® (44%) compared with the FB group (7%, p = 0.04). Participants achieving the NDPP program goal for physical activity (≥150 min/week) did not differ (CE-Zoom® = 75%, FB = 67%, p = 0.91). This pilot trial demonstrated the potential feasibility and effectiveness of the NDPP delivered by CE personnel in a group remote format (Zoom®) to adults with prediabetes living in rural areas

Enabling quantitative data analysis through e-infrastructures

This paper discusses how quantitative data analysis in the social sciences can engage with and exploit an e-Infrastructure. We highlight how a number of activities which are central to quantitative data analysis, referred to as ‘data management’, can benefit from e-infrastructure support. We conclude by discussing how these issues are relevant to the DAMES (Data Management through e-Social Science) research Node, an ongoing project that aims to develop e-Infrastructural resources for quantitative data analysis in the social sciences

A study of low-energy transfer orbits to the Moon: towards an operational optimization technique

In the Earth-Moon system, low-energy orbits are transfer trajectories from the earth to a circumlunar orbit that require less propellant consumption when compared to the traditional methods. In this work we use a Monte Carlo approach to study a great number of such transfer orbits over a wide range of initial conditions. We make statistical and operational considerations on the resulting data, leading to the description of a reliable way of finding "optimal" mission orbits with the tools of multi-objective optimization

Spin Reorientations Induced by Morphology Changes in Fe/Ag(001)

By means of magneto-optical Kerr effect we observe spin reorientations from in-plane to out-of-plane and vice versa upon annealing thin Fe films on Ag(001) at increasing temperatures. Scanning tunneling microscopy images of the different Fe films are used to quantify the surface roughness. The observed spin reorientations can be explained with the experimentally acquired roughness parameters by taking into account the effect of roughness on both the magnetic dipolar and the magnetocrystalline anisotropy.Comment: 4 pages with 3 EPS figure