2,515 research outputs found

    Effect of boundary scattering on spin-hall effect

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    The spin dependent reflection in quasi-two-dimensional electron gas from an impenetrable barrier in presence of Rashba and Dresselhaus spin-orbit coupling is analyzed in detail. It is shown that due to spin-orbit effects the reflected beam split in two beams gives rise to multiple reflection analogous to phenomena birefringence. The interplay between Rashba and Dresselhaus spin-orbit coupling gives rise to anisotropy in Fermi energy surface and a non-zero net spin-polarized current oscillating with two frequencies for all the values of incident angle except at 45o45^{o} when averaged over all components of reflected beam. It is also shown that in over critical region, all the three polarization components as well as net polarization has non-zero values and are exponentially decaying as distance from the barrier increases which in turns spin-accumulation near the barrier is an important consequence of spin-hall effect.Comment: 6 pages, 8 figure

    Preface

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    This inaugural volume includes five manuscripts. Four original papers based clinical and nonclinical studies in small and large domesticated animals and an invited review article are presented to the readers of TRVS. In this issue, Szczepanek et al. have reviewed the role of microRNA in domestic animals. They summarized the existing knowledge about miRNAs synthesis, mechanisms for regulation of the genome their functions in animals physiology; microRNAs as potential biomarkers for veterinary research; the implications associated with dysfunction and dysregulation. Review concludes that microRNA molecules are great targets for understanding biology, physiology and pathology in veterinary science. In the near future, these molecules may become very attractive features for their immediate implementation as biomarkers for many diseases and may contribute to enhancing global agricultural production as well. Brüssow et al. original paper analyzed the impact of unilateral ovarian removal (uni-OXV) on ovarian function, steroid hormone level, fetal distribution and development in gilts. Study concludes that by comparing to intact gilts, only long term uni-OVX could compensate ovarian development. However, short term uni-OVX affects the total number of CL and fetuses, distribution and weight of fetuses in uterine horns and steroid hormone levels. Gehrke et al. original paper reported the relations between feto-pelvic proportion and fertility of black-and-white and red-and-white Polish Holstein-Friesian cows. Study concludes that process of “Holsteinization” of domestic headache of cattle requires selection of bull’s semen not only for heifers but also older cows. Wysocka et al. original paper predicted the hepatic and pituitary gland expression of potential candidate genes in context to maintenance of oxidative balance, negative nitrogen balance, and ketosis in Polish HF and Polish Red cattle. Study conclude that understanding the genetic factors that predispose metabolic disorders in cattle would benefit the dairy industry as a whole by providing producers, breeding services, and veterinarians a tool to forecast a cow’s susceptibility to metabolic disorders. Felsmann and Felsmann original paper examined the impact of changes in Polish law on the possibility of interrupting the spread toxoplasmosis and toxocarosis. Study updated the new changes in the Polish legal acts (acts and regulations) made in recent years in context to combat toxocarosis and toxoplasmosis by the legal authorities of Polish government administration. Study concluded that state public health services do not currently possess the legal means necessary to take effective action leading to the blocking of pathways along which these zoonosis spread

    The role of microRNAs in animal physiology and pathology

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    MicroRNAs are a class of small, evolutionarily conserved, endogenous RNAs, capable of controlling gene expression. MicroRNAs are transcribed by RNA polymerases II and III, generating precursors that undergo a series of cleavage events to form mature microRNA. They play an important regulatory role in animals at the posttranscriptional levels by targeting mRNAs for direct cleavage of mRNAs or repression of mRNA translation. The main biological function of miRNA is the post-translation regulation of cells, like: proliferation and differentiation, cell death, fat metabolism, neuronal patterning and angiogenesis.  These molecules are the main regulators of biological features of economic interest, including body growth, muscle development, signaling transduction, fat deposition, and immunology. In this review, we summarize the existing knowledge about miRNAs synthesis, mechanisms for regulation of the genome their functions in animals physiology and the implications associated with dysfunction and dysregulation

    A Semiparametric Bayesian Approach to a New Dynamic Zero-Inflated Model

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    We develop a dynamic zero-inflated model to analyse the number of hospital admissions within an aging population, which allows for the considerable number of zero hospital admissions at the individual level and occurrence dependence. In addition, certain health conditions may lead to groups of individuals having similar hospital admission rates. We analyse the US Health and Retirement Survey, which includes selfassessed health (SAH), which can be predictive of hospital admissions. Our modelling framework embeds a dynamic hierarchical matrix stick-breaking process to flexibly characterize this dynamic group structure allowing individuals to belong to different SAH groups at different points in time

    EVALUATE THE EFFICACY OF ASHTAVARGASIDDHA BASTI AND UPANAHA SWEDA IN THE MANAGEMENT OF SANDHIGATAVATA

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    Sandhigatavata is the most common form of joint disorder amongst the elderly and obese persons. It is a major cause of morbidity and chronic disability as well as burden on healthcare resources especially for the elderly. This disease keeps an insidious attack, which runs for many years causing the loss of function as well as deformity of the joints, especially weight bearing joints like knee joint. The study was done in two groups, Group A and Group B each group having 15 patients. Patients of Group A received the treatment modalities Ashtavargasiddha Niruhabasti for 8 days. Where, Patients of Group B received Ashtavargasiddha Niruhabasti for 8 days followed by Upanaha Sweda for next 8 days. Subjective parameters were Sandhi Ruk (Pain), Sandhi Graha (Stiffness), Sparshaakshamatva (Tenderness), Sandhi Shotha (Swelling), Sandhi Atopa (Crepitation) and objective parameters were WOMAC, Range of movements, Walking time. According to the statistical analysis Parameters Sandhi Ruk, Walking time better responded in group A compared to group B, Whereas Parameters Sandhi Graha, Sparshaakshamatva (Tenderness), Sandhi Shotha (Swelling), Sandhi Atopa (Crepitation) and objective parameters as WOMAC, Range of movements responded equally in both groups, But more in Group B by comparing their t-values

    Comparison between the two models of dephasing in mesoscopic systems

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    In mesoscopic systems to study the role of inelastic scattering on the phase coherent motion of electrons two phenomenological models have been proposed. In the first one, due to B\"uttiker, one adds a voltage probe into the system (or in the scattering matrix). The second model invokes the complex (or optical) potential in the system Hamiltonian. Studying a simple geometry of a metallic loop in the presence of Aharonov-Bohm magnetic flux, we show that the two probe conductance is symmetric in the reversal of the magnetic field in B\"uttiker's approach. Whereas the two probe conductance within the complex potential model is asymmetric in the magnetic flux reversal contrary to the expected behavior.Comment: 11 pages RevTex, 4 figures inculded, Communicated to PR

    Aharonov-Bohm oscillations and spin transport in a mesoscopic ring with a magnetic impurity

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    We present a detailed analysis of the Aharonov-Bohm (AB) interference oscillations manifested through transmission of an electron in a mesoscopic ring with a magnetic impurity atom inserted in one of its arms. The spin polarization transport is also studied. The electron interacts with the impurity through the exchange interaction leading to exchange spin-flip scattering. Transmission in the spin-flipped and spin-unflipped channels are explicitly calculated. We show that the entanglement between electron and spin-flipper states lead to a reduction of AB oscillations in spite of absence of any inelastic scattering. The spin-conductance (related to spin-polarized transmission coefficient) is asymmetric in the flux reversal as opposed to the two probe conductance which is symmetric under flux reversal. We point out certain limitations of this model in regard to the general notion of dephasing in quantum mechanics.Comment: 6 pages RevTeX, 9 eps figures included, enlarged version of cond-mat/000741
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