Superconductivity in doped FeTe1-xSx (x= 0.00 to 0.25) single crystals

We report self flux growth and characterization of FeTe1-xSx (x= 0.00 to 0.25) single crystal series. Surface X-ray diffraction (XRD) exhibited crystalline nature with growth in (00l) plane. Micro-structural (electron microscopy) images of representative crystals showed the slab-like morphology and near stoichiometric composition. Powder XRD analysis (Rietveld) of single crystals exhibited tetragonal structure with P4/nmm space group and decreasing a and c lattice parameters with increase in x. Electrical resistivity measurements (R-T) showed superconductivity with Tconset at 9.5K and 8.5K for x =0.10 and x =0.25 respectively. The un-doped crystal exhibited known step like anomaly at around 70K. Upper critical field Hc2(0), as calculated from magneto transport for x =0.25 crystal is around 60Tesla and 45Tesla in H//ab and H//c directions. Thermal activation energy [U0(H)] calculated for x =0.10 and 0.25 crystals followed weak power law, indicating single vortex pinning at low fields. Mossbauer spectra for FeTe1-xSx crystals at 300K and 5K are compared with non superconducting FeTe. Both quadrupole splitting (QS) and isomer shift (IS) for S doped crystals were found to decrease. Also at 5K the hyperfine field for x =0.10 superconducting crystal is decreased substantially from 10.6Tesla (FeTe) to 7.2Tesla. For x =0.25 crystal, though small quantity of un-reacted Fe is visible at room temperature, but unlike x =0.10, the low temperature (5K) ordered FeTe hyperfine field is nearly zero.Comment: 20 Pages Text + Figs: Accepted Mat. Res. Exp, Mat. Rex. Exp. (2018

Magnetic properties of Al, V, Mn, and Ru impurities in Fe–Co alloys

Theoretical studies on the magnetic properties of impurities in Fe–Co alloys have been carried out using a molecular-orbital approach within a gradient corrected density functional formalism. The defected alloy is modeled by a large cluster and the calculations on the ordered alloy are used to show that a cluster containing 67 atoms can provide quantitative information on the local magnetic moment. It is found that although bulk Al, V, and Ru are nonmagnetic, all the impurities carry finite moments. While Al and V impurities couple antiferromagnetically, Ru impurities couple ferromagnetically to the host sites. It is shown that the observed composition dependence of the rate of increase of magnetic moment of FexCo1−x alloys upon addition of Mn impurities is due to the change in the magnetic moment of Mn impurities with composition. The reasons for this change and the possibility of stabilizing a higher Mn moment at all concentrations are discussed

Cellular and population plasticity of helper CD4(+) T cell responses

Vertebrates are constantly exposed to pathogens, and the adaptive immunity has most likely evolved to control and clear such infectious agents. CD4(+) T cells are the major players in the adaptive immune response to pathogens. Following recognition of pathogen-derived antigens naïve CD4(+) T cells differentiate into effectors which then control pathogen replication either directly by killing pathogen-infected cells or by assisting with generation of cytotoxic T lymphocytes (CTLs) or pathogen-specific antibodies. Pathogen-specific effector CD4(+) T cells are highly heterogeneous in terms of cytokines they produce. Three major subtypes of effector CD4(+) T cells have been identified: T-helper 1 (Th1) cells producing IFN-γ and TNF-α, Th2 cells producing IL-4 and IL-10, and Th17 cells producing IL-17. How this heterogeneity is maintained and what regulates changes in effector T cell composition during chronic infections remains poorly understood. In this review we discuss recent advances in our understanding of CD4(+) T cell differentiation in response to microbial infections. We propose that a change in the phenotype of pathogen-specific effector CD4(+) T cells during chronic infections, for example, from Th1 to Th2 response as observed in Mycobactrium avium ssp. paratuberculosis (MAP) infection of ruminants, can be achieved by conversion of T cells from one effector subset to another (cellular plasticity) or due to differences in kinetics (differentiation, proliferation, death) of different effector T cell subsets (population plasticity). We also shortly review mathematical models aimed at describing CD4(+) T cell differentiation and outline areas for future experimental and theoretical research. doi: 10.3389/fphys.2013.0020

Sweet sorghum: characteristics and potential

Sweet sorghum (Sorghum bicolor) is simi lar to common grain sorghum wi t h a sugar - r ich stalk. Sweet sorghum is characterized by wide adaptabi l i ty, drought resistance, water logging tolerance, sal ine-alkal i tolerance, rapid growth, high sugar accumulat ion, and biomass. Lengthy growing per iod and high water requi rement are the disadvantages in sugarcane (Saccharum officinarum) and sugarbeet (Beta vulgaris), the main sources of sugar product ion in the wor ld. These factors along wi t h the comparat ive disadvantage of molasses (higher pr ice, and water and air pol lut ion) are expected to increase the interest in sweet sorghum. The water requi rement of sugarcane is about 36000 m3, which is double that of sugarbeet whi le that of sweet sorghum

History of Sorghum Improvement

Sorghum is an important cereal crop in hot and dry agroecologies, where it is difficult to grow other food crops. It has diverse uses as food, feed, fodder, fuel, fiber, and industrial crop. In India, it is grown during both rainy and post–rainy seasons with season specific cultivars. The Indian national program with exhaustive testing in coordinated trials has released over 31 hybrids and 25 varieties for commercial cultivation. International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), with sorghum as one of the mandate crops, has developed parental lines to suit the needs of National Agricultural Research Systems in India and parental lines, hybrids, and varieties to meet the requirement of researchers and farmers in Africa. The Kaoliang of China offer tolerance to cold stress and their research program concentrates on biotic and abiotic stresses. In Africa, sorghum is grown under diverse ecologies predominantly with varieties tolerant to Striga. International Sorghum and Millet (INTSORMIL) and ICRISAT worked together to develop acid soil–resistant genotypes for growing in Latin America. In Australia, the main focus is on developing tolerant cultivars to sorghum midge and drought. In the United States, sorghum is grown in 14 states. The US Department of Agriculture and sorghum checkoff fund the sorghum research program for genetic enhancement of sorghum grown for feed, fodder, and fuel. INTSORMIL has projects in 20 developing countries in Africa and America and focuses on improving the production in these areas. In Europe, sorghum is cultivated for cattle feed, while broomcorn types are used for industrial uses in paper making. Thus, sorghum meets the diverse requirements of people across the globe and crop improvement programs are well placed catering to the needs of growers

Some theoretical models for solitary structures of boundary layer waves

International audienceSolitary electrostatic structures have been observed in and around auroral zone field lines at various altitudes ranging from close to the ionosphere, to the magnetopause low-latitude boundary layer (LLBL) and cusp on the dayside, and to the plasma sheet boundary layer on the night-side. In this review, various models based on solitons/double layers and BGK modes or phase space holes are discussed in order to explain the characteristics of these solitary structures

A New Large Grain Sorghum Hybrid: JKSH 22.An ICRISAT-Private Sector Success Story

Before 1990, several breeding programs – in both private and public sectors in India – extensively used a single female parent (296B) in their hybrid development programs. The seed parent, 296A is highly sensitive to low temperature leading to difficulties in hybrid seed production. This led to increased hybrid seed costs. Since only one female parent was extensively used, it also led to reduced diversity of hybrids grown by farmers in India

Development of Slide Enzyme Linked Immunosorbent Assay (SELISA) for Detection of Trypanosoma evansi Infection in Bovines

The slide enzyme linked immunosorbent assay (SELISA) was standardized for detection of antibodies specific to Trypanosoma evansi and subsequently used for the screening of naturally infected bovine sera. A novel SELISA, a modification of the standard ELISA technique was used for the detection of antibodies against Trypanosoma evansi in bovines using positive and negative control sera. The test is based on immunostaining of the fixed whole Trypanosoma evansi organisms on microscopic glass slide, incubation with sera, antibovine IgG-HRPO conjugate and substrate Diaminobenzidine tetrahydrochloride (DAB). Finally the reaction was read under oil immersion of microscope. A total of 702 sera samples from bovines in Rayalaseema region of Andhra Pradesh were examined by SELISA and 192 were found positive for Trypanosoma evansi antibodies