122 research outputs found

    Bit-Level Systolic Architecture for a Matrix-Matrix Multiplier

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    Highly efficient arithmetic operations are necessary to achieve the desired performance in many real-time systems and digital image processing applications. In all these applications, one of the important arithmetic operations frequently performed is to multiply and accumulate with small computational time. In this paper, a 4-bit serial - parallel multiplier, which can perform both positive and negative multiplications, is presented. Baugh-Wooley algorithm necessitates complementation of last bit of each partial product except the last partial product in which all but the last bit are complemented. In the proposed algorithm all bits of the last partial product are complemented. This modification results in considerable reduction in hardware compared to Baugh-Wooley multiplier. This multiplier can be used for implementation of discrete orthogonal transforms, which are used in many applications, including image and signal processing. This paper presents a 2D bit-level systolic architecture for a matrixmatrix multiplier. A comparison with similar structures has shown that the proposed structure performs better

    Formulation and Evaluation of Tacrolimus Transdermal Gel

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    The present investigation is concerned with formulation and evaluation of Transdermal gels of Tacrolimus, anti-psoriasis drug, to circumvent the first pass effect and to improve its bioavailability with reduction in dosing frequency and dose related side effects. Twelve formulations were developed with varying concentrations of polymers like Carbopol 934P, HPMCK4M and Sodium CMC. The gels were tested for clarity, Homogeneity, Spreadability, Extrudability, Viscosity, surface pH, drug Content uniformity, in-vitro drug diffusion study and ex-vivo permeation study using rat abdominal skin. FTIR studies showed no evidence on interactions between drug, polymers and excipients. The best in-vitro drug release profile was achieved with the formulation F4 containing 0.5 mg of exhibited 6 hr drug release i.e. 98.68 % with desired therapeutic concentration which contains the drug and Carbopol 934p in the ratio of 1:2. The surface pH, drug content and viscosity of the formulation F4 was found to be 6.27, 101.3% and 3, 10,000cps respectively. The drug permeation from formulation F4 was slow and steady and 0.89gm of tacrolimus could permeate through the rat abdominal skin membrane with a flux of 0.071 gm hr-1 cm-2. The in-vitro release kinetics studies reveal that all formulations fit well with zero order kinetics followed by non-Fickian diffusion mechanism. Keywords: Transdermal gel, Viscosity, In-vitro drug release, In-vitro drug release kinetics study, Ex-vivo permeation stud

    Inexact sector-wise planning of land and water resources in a large canal command in the sub-humid region of eastern India

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    A stepwise linear programming (SLP) is utilized for solving the land and water resources management problem. The formulated model considers integrated planning of surface water and ground water resources. The developed model is applied to Hirakud command area of western Odisha. The western part of Odisha faces acute shortage of drinking water almost every year. The study area is bounded by Mahanadi river in the west. Model is applied for the major crops in the canal command area. The model is evaluated for different inexact bounds on available natural resources (land and water). The model results are useful in evolving crop specific land utilization levels and quantities of surface and ground water resources for deriving maximum benefit. The model also provides season specific crop scheduling information. The performance evaluation study shows potential applicability of the developed methodology

    Electronic properties of ordered and disordered linear clusters of atoms and molecules

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    The electronic properties of one-dimensional clusters of N atoms or molecules have been studied. The model used is similar to the Kronig-Penney model with the potential offered by each ion being approximated by an attractive delta function. The energy eigenvalues, the eigenstates and the density of states are calculated exactly for a linear cluster of N atoms or molecules. The dependence of these quantities on the various parameters of the problem show interesting behavior. Effects of random distribution of the positions of the atoms and random distribution of the strengths of the potential have also been studied. The results obtained in this paper can have direct applications for linear chain of atoms produced on metal surfaces or artificially created chain of atoms by using scanning tunneling microscope or in studying molecular conduction of electrons across one-dimensional barriers.Comment: A shorter version of this paper to be published in Physica

    Anemia prevalence in women of reproductive age in low- and middle-income countries between 2000 and 2018

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    Anemia is a globally widespread condition in women and is associated with reduced economic productivity and increased mortality worldwide. Here we map annual 2000–2018 geospatial estimates of anemia prevalence in women of reproductive age (15–49 years) across 82 low- and middle-income countries (LMICs), stratify anemia by severity and aggregate results to policy-relevant administrative and national levels. Additionally, we provide subnational disparity analyses to provide a comprehensive overview of anemia prevalence inequalities within these countries and predict progress toward the World Health Organization’s Global Nutrition Target (WHO GNT) to reduce anemia by half by 2030. Our results demonstrate widespread moderate improvements in overall anemia prevalence but identify only three LMICs with a high probability of achieving the WHO GNT by 2030 at a national scale, and no LMIC is expected to achieve the target in all their subnational administrative units. Our maps show where large within-country disparities occur, as well as areas likely to fall short of the WHO GNT, offering precision public health tools so that adequate resource allocation and subsequent interventions can be targeted to the most vulnerable populations.Peer reviewe

    Search for Gravitational Waves Associated with Gamma-Ray Bursts Detected by Fermi and Swift during the LIGO-Virgo Run O3b

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    We search for gravitational-wave signals associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the second half of the third observing run of Advanced LIGO and Advanced Virgo (2019 November 1 15:00 UTC-2020 March 27 17:00 UTC). We conduct two independent searches: A generic gravitational-wave transients search to analyze 86 GRBs and an analysis to target binary mergers with at least one neutron star as short GRB progenitors for 17 events. We find no significant evidence for gravitational-wave signals associated with any of these GRBs. A weighted binomial test of the combined results finds no evidence for subthreshold gravitational-wave signals associated with this GRB ensemble either. We use several source types and signal morphologies during the searches, resulting in lower bounds on the estimated distance to each GRB. Finally, we constrain the population of low-luminosity short GRBs using results from the first to the third observing runs of Advanced LIGO and Advanced Virgo. The resulting population is in accordance with the local binary neutron star merger rate. © 2022. The Author(s). Published by the American Astronomical Society

    Narrowband Searches for Continuous and Long-duration Transient Gravitational Waves from Known Pulsars in the LIGO-Virgo Third Observing Run

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    Isolated neutron stars that are asymmetric with respect to their spin axis are possible sources of detectable continuous gravitational waves. This paper presents a fully coherent search for such signals from eighteen pulsars in data from LIGO and Virgo's third observing run (O3). For known pulsars, efficient and sensitive matched-filter searches can be carried out if one assumes the gravitational radiation is phase-locked to the electromagnetic emission. In the search presented here, we relax this assumption and allow both the frequency and the time derivative of the frequency of the gravitational waves to vary in a small range around those inferred from electromagnetic observations. We find no evidence for continuous gravitational waves, and set upper limits on the strain amplitude for each target. These limits are more constraining for seven of the targets than the spin-down limit defined by ascribing all rotational energy loss to gravitational radiation. In an additional search, we look in O3 data for long-duration (hours-months) transient gravitational waves in the aftermath of pulsar glitches for six targets with a total of nine glitches. We report two marginal outliers from this search, but find no clear evidence for such emission either. The resulting duration-dependent strain upper limits do not surpass indirect energy constraints for any of these targets. © 2022. The Author(s). Published by the American Astronomical Society

    Anemia prevalence in women of reproductive age in low- and middle-income countries between 2000 and 2018

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    Repositioning of the global epicentre of non-optimal cholesterol

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    High blood cholesterol is typically considered a feature of wealthy western countries1,2. However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world3 and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health4,5. However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol—which is a marker of cardiovascular risk—changed from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million–4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.</p
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