Chiral magnetoresistance in Pt/Co/Pt zigzag wires

The Rashba effect leads to a chiral precession of the spins of moving electrons while the Dzyaloshinskii-Moriya interaction (DMI) generates preference towards a chiral profile of local spins. We predict that the exchange interaction between these two spin systems results in a 'chiral' magnetoresistance depending on the chirality of the local spin texture. We observe this magnetoresistance by measuring the domain wall (DW) resistance in a uniquely designed Pt/Co/Pt zigzag wire, and by changing the chirality of the DW with applying an in-plane magnetic field. A chirality-dependent DW resistance is found, and a quantitative analysis shows a good agreement with a theory based on the Rashba model. Moreover, the DW resistance measurement allows us to independently determine the strength of the Rashba effect and the DMI simultaneously, and the result implies a possible correlation between the Rashba effect, the DMI, and the symmetric Heisenberg exchange

Synaptic Pattern of KA1 and KA2 upon the Direction-Selective Ganglion Cells in Developing and Adult Mouse Retina

The detection of image motion is important to vision. Direction-selective retinal ganglion cells (DS-RGCs) respond strongly to stimuli moving in one direction of motion and are strongly inhibited by stimuli moving in the opposite direction. In this article, we investigated the distributions of kainate glutamate receptor subtypes KA1 and KA2 on the dendritic arbors of DS-RGCs in developing (5, 10) days postnatal (PN) and adult mouse retina to search for anisotropies. The distribution of kainate receptor subtypes on the DS-RGCs was determined using antibody immunocytochemistry. To identify their characteristic morphology, DS-RGCs were injected with Lucifer yellow. The triple-labeled images of dendrites, kinesin II, and receptors were visualized by confocal microscopy and were reconstructed from high-resolution confocal images. We found no evidence of asymmetry in any of the kainate receptor subunits examined on the dendritic arbors of both the On and Off layers of DS-RGCs in all periods of developing and adult stage that would predict direction selectivity

Degradation mechanism of Schottky diodes on inductively coupled plasma-etched n-type 4H-SiC

The degradation mechanism of Ta Schottky contact on 4H-SiC exposed to an inductively coupled plasma (ICP) was studied using deep-level transient spectroscopy and angle-resolved x-ray photoelectron spectroscopy (XPS). Four kinds of traps T1, T2, T3, and T4 were observed in the ICP-etched sample. The T4 trap was deep in the bulk, but the shallower levels, T1, T2 and T3, were localized near the contact. From angle-resolved XPS measurements, the ICP-etched surface was found to be carbon deficient, meaning the production of carbon vacancies by ICP etching. The activation energies 0.48 (T3 trap) and 0.60 eV (T4 trap) agreed well with the previously proposed energy level of V-C (0.5 eV). The ICP-induced traps provided a path for the transport of electrons at the interface of metal with Sic, leading to a reduction of the Schottky barrier height and an increase of the gate leakage current.open6

Violacein: Properties and Production of a Versatile Bacterial Pigment

Violacein-producing bacteria, with their striking purple hues, have undoubtedly piqued the curiosity of scientists since their first discovery. The bisindole violacein is formed by the condensation of two tryptophan molecules through the action of five proteins. The genes required for its production, vio ABCDE, and the regulatory mechanisms employed have been studied within a small number of violacein-producing strains. As a compound, violacein is known to have diverse biological activities, including being an anticancer agent and being an antibiotic against Staphylococcus aureus and other Gram-positive pathogens. Identifying the biological roles of this pigmented molecule is of particular interest, and understanding violacein's function and mechanism of action has relevance to those unmasking any of its commercial or therapeutic benefits. Unfortunately, the production of violacein and its related derivatives is not easy and so various groups are also seeking to improve the fermentative yields of violacein through genetic engineering and synthetic biology. This review discusses the recent trends in the research and production of violacein by both natural and genetically modified bacterial strains.open0

The Large-scale and Small-scale Clustering of Lyman-Break Galaxies at 3.5 < z< 5.5 from the GOODS survey

We report on the angular correlation function of Lyman-break galaxies (LBGs) at z~4 and 5 from deep samples obtained from the Great Observatories Deep Origins Survey (GOODS). Similar to LBGs at z~3, the shape of w(theta) of the GOODS LBGs is well approximated by a power-law with slope beta~0.6 at angular separation theta > 10 arcsec. The clustering strength of z~4, 5 LBGs also depends on the rest-frame UV luminosity, with brighter galaxies more strongly clustered than fainter ones, implying a general correlation between halos' mass and LBGs' star-formation rate. At smaller separations, w(theta) of deep samples significantly exceeds the extrapolation of the large-scale power-law fit, implying enhanced spatial clustering at scales r < 1 Mpc. We also find that bright LBGs statistically have more faint companions on scales theta < 20 arcsec than fainter ones, showing that the enhanced small-scale clustering is very likely due to sub-structure, namely the fact that massive halos can host multiple galaxies. A simple model for the halo occupation distribution and the CDM halo mass function reproduce well the observed w(theta). The scaling relationship of the clustering strength with volume density and with redshift is quantitatively consistent with that of CDM halos. A comparison of the clustering strength of three samples of equal luminosity limit at z ~ 3, 4 and 5 shows that the LBGs at z~5 are hosted in halos about one order of magnitude less massive than those in the lower redshift bins, suggesting that star-formation was more efficient at higher-redshift.Comment: replaced with the version accepted for publication in ApJ. 46 pages, 10 figures; minor changes to text, one subsection adde

Super-lattice, rhombus, square, and hexagonal standing waves in magnetically driven ferrofluid surface

Standing wave patterns that arise on the surface of ferrofluids by (single frequency) parametric forcing with an ac magnetic field are investigated experimentally. Depending on the frequency and amplitude of the forcing, the system exhibits various patterns including a superlattice and subharmonic rhombuses as well as conventional harmonic hexagons and subharmonic squares. The superlattice arises in a bicritical situation where harmonic and subharmonic modes collide. The rhombic pattern arises due to the non-monotonic dispersion relation of a ferrofluid

Maternal and infant antiretroviral therapy adherence among women living with HIV in rural South Africa: a cluster randomised trial of the role of male partner participation on adherence and PMTCT uptake

‘Mother-to-child transmission of HIV’ can occur during the period of pregnancy, childbirth, or breastfeeding. ‘Prevention of mother-to-child transmission of HIV’ (PMTCT) in Mpumalanga Province, South Africa, is especially vital as the prevalence of HIV is 28.2% in women aged 15–49. PMTCT interventions resulted in a drop of MTCT rates in Mpumalanga from ∼2% in 2015 to 1.3% in 2016. This randomised controlled trial in Mpumalanga examined the potential impact of a lay healthcare worker administered intervention, ‘Protect Your Family’, on maternal and infant adherence, and to assess the relative influence of male partner involvement on infant and maternal adherence. This cluster randomised controlled trial used a two-phase and two-condition (experimental or control) study design where participants (n = 1399) did assessments both during pregnancy and post-postpartum. Only women participated in Phase 1, and both female and male partners participated in Phase 2. Results indicated that male involvement was associated with self-reported maternal or infant antiretroviral therapy (ART) adherence, but the intervention was not associated with ART adherence. Self-reported adherence was associated with depression, age, and partner HIV status. The study results provide support for the involvement of men in the antenatal clinic setting during pregnancy. Results also support further research on the meaning and assessment of male involvement and clarification of the constructs underlying the concept in the sub-Saharan African context. Outcomes provide support for male involvement and treatment of depression as adjuncts to improve uptake of both maternal and infant medication as part of the PMTCT protocol

Biomass production of herbaceous energy crops in the United States: field trial results and yield potential maps from the multiyear regional feedstock partnership

Current knowledge of yield potential and best agronomic management practices for perennial bioenergy grasses is primarily derived from small‐scale and short‐term studies, yet these studies inform policy at the national scale. In an effort to learn more about how bioenergy grasses perform across multiple locations and years, the U.S. Department of Energy (US DOE)/Sun Grant Initiative Regional Feedstock Partnership was initiated in 2008. The objectives of the Feedstock Partnership were to (1) provide a wide range of information for feedstock selection (species choice) and management practice options for a variety of regions and (2) develop national maps of potential feedstock yield for each of the herbaceous species evaluated. The Feedstock Partnership expands our previous understanding of the bioenergy potential of switchgrass, Miscanthus, sorghum, energycane, and prairie mixtures on Conservation Reserve Program land by conducting long‐term, replicated trials of each species at diverse environments in the U.S. Trials were initiated between 2008 and 2010 and completed between 2012 and 2015 depending on species. Field‐scale plots were utilized for switchgrass and Conservation Reserve Program trials to use traditional agricultural machinery. This is important as we know that the smaller scale studies often overestimated yield potential of some of these species. Insufficient vegetative propagules of energycane and Miscanthus prohibited farm‐scale trials of these species. The Feedstock Partnership studies also confirmed that environmental differences across years and across sites had a large impact on biomass production. Nitrogen application had variable effects across feedstocks, but some nitrogen fertilizer generally had a positive effect. National yield potential maps were developed using PRISM‐ELM for each species in the Feedstock Partnership. This manuscript, with the accompanying supplemental data, will be useful in making decisions about feedstock selection as well as agronomic practices across a wide region of the country