6,232 research outputs found

    Exploring the high-pressure materials genome

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    A thorough in situ characterization of materials at extreme conditions is challenging, and computational tools such as crystal structural search methods in combination with ab initio calculations are widely used to guide experiments by predicting the composition, structure, and properties of high-pressure compounds. However, such techniques are usually computationally expensive and not suitable for large-scale combinatorial exploration. On the other hand, data-driven computational approaches using large materials databases are useful for the analysis of energetics and stability of hundreds of thousands of compounds, but their utility for materials discovery is largely limited to idealized conditions of zero temperature and pressure. Here, we present a novel framework combining the two computational approaches, using a simple linear approximation to the enthalpy of a compound in conjunction with ambient-conditions data currently available in high-throughput databases of calculated materials properties. We demonstrate its utility by explaining the occurrence of phases in nature that are not ground states at ambient conditions and estimating the pressures at which such ambient-metastable phases become thermodynamically accessible, as well as guiding the exploration of ambient-immiscible binary systems via sophisticated structural search methods to discover new stable high-pressure phases.Comment: 14 pages, 6 figure

    Technical Efficiency and its Determinants in Tomato Production in Karnataka, India: Data Envelopment Analysis (DEA) Approach

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    Low productivity in agriculture is mainly due to the inability of the farmers to exploit the available technologies fully, resulting in lower efficiencies of production. The present study has estimated the technical and scale efficiencies of tomato-producing farms in Karnataka, considering different production levels and has identified the determining factors of their technical efficiency. The study is based on the data collected from the major tomato-producing regions of Karnataka, viz. Kolar and Bangalore rural districts of Karnataka, under three-production situations, viz. small, medium and large farms. Data Envelopment analysis (DEA) and log linear regression models have been used for estimating the technical efficiency and its determining factors, respectively. The study has indicated that most of the farms irrespective of size of holding have shown technical inefficiency problems. The medium farmers have been observed with best measures of technical efficiency, which has been explained by factors such as the land and labour productivity and education. Though medium farmers have been found efficient, with higher yields, it is the small farmers who have emerged as price-efficient producers in terms of lower cost on production (Rs 1.72/kg compared to Rs 2.01 in medium farms and Rs 1.85 in large farms) and higher unit profit. Most of the farms have been observed to have potential to expand production and productivity, increasing technical efficiency as majority have been performing with increasing returns to scale.Agricultural and Food Policy,

    The finite temperature QCD using 2+1 flavors of domain wall fermions at N_t = 8

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    We study the region of the QCD phase transition using 2+1 flavors of domain wall fermions (DWF) and a 163×816^3 \times 8 lattice volume with a fifth dimension of Ls=32L_s = 32. The disconnected light quark chiral susceptibility, quark number susceptibility and the Polyakov loop suggest a chiral and deconfining crossover transition lying between 155 and 185 MeV for our choice of quark mass and lattice spacing. In this region the lattice scale deduced from the Sommer parameter r0r_0 is a11.3a^{-1} \approx 1.3 GeV, the pion mass is 300\approx 300 MeV and the kaon mass is approximately physical. The peak in the chiral susceptibility implies a pseudo critical temperature Tc=171(10)(17)T_c = 171(10)(17) MeV where the first error is associated with determining the peak location and the second with our unphysical light quark mass and non-zero lattice spacing. The effects of residual chiral symmetry breaking on the chiral condensate and disconnected chiral susceptibility are studied using several values of the valence LsL_s.Comment: 41 pages, 10 tables, 13 figure

    Toward a unified theory of sparse dimensionality reduction in Euclidean space

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    Let ΦRm×n\Phi\in\mathbb{R}^{m\times n} be a sparse Johnson-Lindenstrauss transform [KN14] with ss non-zeroes per column. For a subset TT of the unit sphere, ε(0,1/2)\varepsilon\in(0,1/2) given, we study settings for m,sm,s required to ensure EΦsupxTΦx221<ε, \mathop{\mathbb{E}}_\Phi \sup_{x\in T} \left|\|\Phi x\|_2^2 - 1 \right| < \varepsilon , i.e. so that Φ\Phi preserves the norm of every xTx\in T simultaneously and multiplicatively up to 1+ε1+\varepsilon. We introduce a new complexity parameter, which depends on the geometry of TT, and show that it suffices to choose ss and mm such that this parameter is small. Our result is a sparse analog of Gordon's theorem, which was concerned with a dense Φ\Phi having i.i.d. Gaussian entries. We qualitatively unify several results related to the Johnson-Lindenstrauss lemma, subspace embeddings, and Fourier-based restricted isometries. Our work also implies new results in using the sparse Johnson-Lindenstrauss transform in numerical linear algebra, classical and model-based compressed sensing, manifold learning, and constrained least squares problems such as the Lasso

    Ayurvedic Management of Systemic Lupus Erythematosus Overlap Vasculitis vis a vis Vatarakta - A Case Report

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    Systemic Lupus erythematosus is the classic prototype of multisystem disease of autoimmune origin. SLE may be associated Vasculitis as an overlap syndrome. In this paper, a patient diagnosed as SLE with Vasculitis, which was managed successfully by Ayurveda treatment is discussed. A 39 year old female patient came to hospital with complaint of severe pain and burning sensation in both the legs for two months, associated with ulceration and gangrene of toes of both the legs for the last 15 days. She was diagnosed as SLE overlap vasculitis at a higher medical centre with relevant investigations and advised to go for amputation. As patient was not willing for surgery came to Ayurveda treatment. The condition was diagnosed as disease Vatarakta and treatment was planned accordingly. Treatment was planned by selecting suitable oral medicines, planning suitable Panchakarma procedures along with the ulcer management. Guduchi (Tinospora cordifolia) was the main drug which is used in Rasayana dosage. Patient responded well and we could able to save the limb. Patient was under follow up for more than a year without any complications and relapses

    Night sky at the Indian Astronomical Observatory during 2000-2008

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    We present an analysis of the optical night sky brightness and extinction coefficient measurements in UBVRI at the Indian Astronomical Observatory (IAO), Hanle, during the period 2003-2008. They are obtained from an analysis of CCD images acquired at the 2 m Himalayan Chandra Telescope at IAO. Night sky brightness was estimated using 210 HFOSC images obtained on 47 nights and covering the declining phase of solar activity cycle-23. The zenith corrected values of the moonless night sky brightness in mag/square arcsecs are 22.14(U), 22.42(B), 21.28(V), 20.54(R) and 18.86(I) band. This shows that IAO is a dark site for optical observations. No clear dependency of sky brightness with solar activity is found. Extinction values at IAO are derived from an analysis of 1325 images over 58 nights. They are found to be 0.36 in U-band, 0.21 in B-band, 0.12 in V-band, 0.09 in R-band and 0.05 in I-band. On average, extinction during the summer months is slightly larger than that during the winter months. No clear evidence for a correlation between extinction in all bands and the average night time wind speed is found. Also presented here is the low resolution moonless optical night sky spectrum for IAO covering the wavelength range 3000-9300 \AA. Hanle region thus has the required characteristics of a good astronomical site in terms of night sky brightness and extinction, and could be a natural candidate site for any future large aperture Indian optical-infrared telescope(s).Comment: 18 pages, 7 figures, uses basi.cls, accepted for publication in Bulletin of the Astronomical Society of Indi

    Correlation of serum lithium levels and thyroid function tests in subjects of bipolar affective disorder: a prospective hospital-based study

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    Background: Lithium is used in the prophylaxis of long-term therapy of bipolar affective disorder (BPAD) as a mood-stabilizing agent. Thyroid function abnormality is very commonly seen adverse effect, more common in females than males. This study aimed to correlate lithium levels and thyroid function abnormalities associated with it.Methods: Evaluation of medical records of 150 patients in Father Muller Medical College with BPAD, who were treated for 6 months with lithium, carried out from February, 12 2014 to July, 20 2014. Serum lithium levels done by ion selective electrode method in ilyte analyzer and thyroid function test (TFT) by electrochemiluminescence. Data are analyzed by Karl Pearson correlation coefficient.Results: Correlation of lithium levels and TFT in BPAD patients according to Karl Pearson correlation coefficient was negative with significant p&lt;0.002. Among 150 enrolled candidates, 52 (34.67%) were females and 98 (65.4%) were males, 4% (6) patients (3 males and 3 females) had thyroid stimulating hormone (TSH) value &lt;0.27 with an average lithium value of 1.35 mEq/L, 6% (9) patients (5 males and 4 females) had TSH value &gt;4.2 with an average lithium levels of 0.44 mEq/L and 90% of the patients with an average lithium levels 0.66 mEq/L had no thyroid function abnormalities.Conclusions: As already known, Lithium is a drug of narrow therapeutic index and females are more prone for thyroid function abnormalities. Appropriate monitoring of serum lithium levels will aid in necessary dose adjustment and ensure proper utilization of drug

    Percutaneous pulmonary valve implantation in humans - Results in 59 consecutive patients

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    Background - Right ventricular outflow tract (RVOT) reconstruction with valved conduits in infancy and childhood leads to reintervention for pulmonary regurgitation and stenosis in later life.Methods and Results - Patients with pulmonary regurgitation with or without stenosis after repair of congenital heart disease had percutaneous pulmonary valve implantation (PPVI). Mortality, hemodynamic improvement, freedom from explantation, and subjective and objective changes in exercise tolerance were end points. PPVI was performed successfully in 58 patients, 32 male, with a median age of 16 years and median weight of 56 kg. The majority had a variant of tetralogy of Fallot (n = 36), or transposition of the great arteries, ventricular septal defect with pulmonary stenosis (n = 8). The right ventricular (RV) pressure (64.4 +/- 17.2 to 50.4 +/- 14 mm Hg, P < 0.001), RVOT gradient (33 +/- 24.6 to 19.5 +/- 15.3, P < 0.001), and pulmonary regurgitation ( PR) (grade 2 of greater before, none greater than grade 2 after, P < 0.001) decreased significantly after PPVI. MRI showed significant reduction in PR fraction (21 +/- 13% versus 3 +/- 4%, P < 0.001) and in RV end-diastolic volume (EDV) (94 +/- 28 versus 82 +/- 24 mL (.) beat(-1) (.) m(-2), P < 0.001) and a significant increase in left ventricular EDV ( 64 +/- 12 versus 71 +/- 13 mL (.) beat(-1.) m(-2), P = 0.005) and effective RV stroke volume ( 37 +/- 7 versus 42 +/- 9 mL (.) beat(-1) (.) m(-2), P = 0.006) in 28 patients (age 19 +/- 8 years). A further 16 subjects, on metabolic exercise testing, showed significant improvement in V(O2)max (26 +/- 7 versus 29 +/- 6 mL (.) kg(-1) (.) min(-1), P < 0.001). There was no mortality.Conclusions - PPVI is feasible at low risk, with quantifiable improvement in MRI-defined ventricular parameters and pulmonary regurgitation, and results in subjective and objective improvement in exercise capacity
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