Linear-scaling DFT+U with full local orbital optimization

We present an approach to the DFT+U method (Density Functional Theory + Hubbard model) within which the computational effort for calculation of ground state energies and forces scales linearly with system size. We employ a formulation of the Hubbard model using nonorthogonal projector functions to define the localized subspaces, and apply it to a local-orbital DFT method including in situ orbital optimization. The resulting approach thus combines linear-scaling and systematic variational convergence. We demonstrate the scaling of the method by applying it to nickel oxide nano-clusters with sizes exceeding 7,000 atoms.Comment: 10 pages, 4 figures. This version (v3) matches that accepted for Physical Review B on 30th January 201

Digital/web-based technologies and purchasing and supply management: A UK Study

The digital revolution on the web/internet is believed to be having a major impact on the performance of firms’ purchasing and supply functions. Beyond anecdotal evidence however, little is known about the actual level of utilisation of web-based interaction technologies in purchasing and supply management (P&SM). This paper addresses this gap through an empirical survey of 156 UK-based organisations. Findings indicate that only six in every ten organisations use digital/web-based technology (DWBT) in P&SM, and that the usage level is particularly low in SMEs. Current uses, and the importance of DWBT in P&SM in the future are reported. The paper also investigates the perceived benefits of DWBT in this area, and the link between uses, benefits and P&SM relationship orientation. The evidence suggests that at present DWBT is not a key driver of closer (collaborative) buyer-supplier relationship development. Implications are put forward

New gaps between zeros of fourth-order differential equations via Opial inequalities

In this paper, for a fourth-order differential equation, we will establish some lower bounds for the distance between zeros of a nontrivial solution and also lower bounds for the distance between zeros of a solution and/or its derivatives. We also give some new results related to some boundary value problems in the theory of bending of beams. The main results will be proved by making use of some generalizations of Opial and Wirtinger-type inequalities. Some examples are considered to illustrate the main results

Vanadium dioxide : A Peierls-Mott insulator stable against disorder

Vanadium dioxide undergoes a first order metal-insulator transition at 340 K. In this work, we develop and carry out state of the art linear scaling DFT calculations refined with non-local dynamical mean-field theory. We identify a complex mechanism, a Peierls-assisted orbital selection Mott instability, which is responsible for the insulating M$_1$ phase, and furthermore survives a moderate degree of disorder.Comment: 5 pages, 4 figures. Supplementary material 8 pages, 4 figures. This version (v2) matches that accepted for Physical Review Letters on 16th May 201

Oscillation of certain fourth order functional differential equations

Some new criteria for the oscillation of fourth-order nonlinear functional differential equations of the special form are established.Встановлено деякі нові критерії коливання нелінійних функціональних диференціальних рівнянь спеціального вигляду

Developmental Exposure of Rats to Chlorpyrifos Elicits Sex-Selective Hyperlipidemia and Hyperinsulinemia in Adulthood

Developmental exposure to chlorpyrifos alters cell signaling both in the brain and in peripheral tissues, affecting the responses to a variety of neurotransmitters and hormones. We administered 1 mg/kg/day chlorpyrifos to rats on postnatal days 1–4, a regimen below the threshold for systemic toxicity. When tested in adulthood, chlorpyrifos-exposed animals displayed elevations in plasma cholesterol and triglycerides, without underlying alterations in nonesterified free fatty acids and glycerol. This effect was restricted to males. Similarly, in the postprandial state, male rats showed hyperinsulinemia in the face of normal circulating glucose levels but demonstrated appropriate reduction of circulating insulin concentrations after fasting. These outcomes and sex selectivity resemble earlier findings at the cellular level, which identified hepatic hyperresponsiveness to gluconeogenic inputs from β-adrenoceptors or glucagon receptors. Our results thus indicate that apparently subtoxic neonatal chlorpyrifos exposure, devoid of effects on viability or growth but within the parameters of human fetal or neonatal exposures, produce a metabolic pattern for plasma lipids and insulin that resembles the major adult risk factors for atherosclerosis and type 2 diabetes mellitus

New kinds of generalized variational-like inequality problems in topological vector spaces

AbstractIn this work, we consider a generalized nonlinear variational-like inequality problem, in topological vector spaces, and, by using the KKM technique, we prove an existence theorem. Our result extends a theorem of Ahmad and Irfan [R. Ahmad, S.S. Irfan, On the generalized nonlinear variational-like inequality problems, Appl. Math. Lett. 19 (2006) 294–297]

A BIOMECHANICAL ANALYSIS OF FRONT VERSUS BACK SQUAT: INJURY IMPLICATIONS

The aim of this study was to examine the differences in trunk and lower limb kinematics between the front and back squat. 2D kinematic data was collected as participants (n = 12) completed three repetitions of both front and back squat exercises at 50 % of their back squat one repetition maximum. Stance width was standardised at 107(±10) % of biacromial breadth. The Wilcoxon signed ranks test was used to examine significant differences in dependent variables between both techniques. Results showed that the back squat exhibited a significantly greater trunk lean than the front squat throughout (p < 0.05) with no differences occurring in knee joint kinematics. The results of this study in conjunction with other squat related literature (Russell et al., 1989) suggest that the back squat gives rise to an increased risk of lower back injury

Learning-based quality control for cardiac MR images

The effectiveness of a cardiovascular magnetic resonance (CMR) scan depends on the ability of the operator to correctly tune the acquisition parameters to the subject being scanned and on the potential occurrence of imaging artifacts, such as cardiac and respiratory motion. In the clinical practice, a quality control step is performed by visual assessment of the acquired images; however, this procedure is strongly operator-dependent, cumbersome, and sometimes incompatible with the time constraints in clinical settings and large-scale studies. We propose a fast, fully automated, and learning-based quality control pipeline for CMR images, specifically for short-axis image stacks. Our pipeline performs three important quality checks: 1) heart coverage estimation; 2) inter-slice motion detection; 3) image contrast estimation in the cardiac region. The pipeline uses a hybrid decision forest method—integrating both regression and structured classification models—to extract landmarks and probabilistic segmentation maps from both long- and short-axis images as a basis to perform the quality checks. The technique was tested on up to 3000 cases from the UK Biobank and on 100 cases from the UK Digital Heart Project and validated against manual annotations and visual inspections performed by expert interpreters. The results show the capability of the proposed pipeline to correctly detect incomplete or corrupted scans (e.g., on UK Biobank, sensitivity and specificity, respectively, 88% and 99% for heart coverage estimation and 85% and 95% for motion detection), allowing their exclusion from the analyzed dataset or the triggering of a new acquisition

Anxiety-like behavior and structural changes of the bed nucleus of the stria terminalis (BNST) in gestational protein-restricted male offspring

Animal evidence has suggested that maternal emotional and nutritional stress during pregnancy is associated with behavioral outcomes in offspring. The nature of the stresses applied may differ, but it is often assumed that the mother's hippocampus-hypothalamic-pituitary-adrenal (HHPA) axis response releases higher levels of glucocorticoid hormones. The bed nucleus of the stria terminalis (BNST) is in a pivotal position to regulate the HHPA axis and the stress response, and it has been implicated in anxiety behavior. In the current study, to search whether BNST structural changes and neurochemical alterations are associated with anxiety-related behavior in adult gestational protein-restricted offspring relative to an age-matched normal protein diet (NP) rats, we conduct behavioral tests and, BNST dendritic tree analysis by Sholl analysis, associated to immunoblotting-protein quantification [11β-HSD2, GR, MR, AT1R, 5HT1A and 5HT2A, corticotrophin-releasing factor (CRH) and CRH1]. Dams were maintained either on isocaloric standard rodent chow [with NP content, 17% casein or low protein content (LP), 6% casein] chow throughout their entire pregnancy. Here, in rats subjected to gestational protein restriction, we found: (a) a significant reduction in dendritic length and impoverished dendritic arborization in BNST neurons; (b) an elevated plasmatic corticosterone levels; and (c) associated with enhanced anxiety-like behavior when compared with age-matched NP offspring. Moreover, altered protein (11β-HSD2, GR, MR and type 1 CRH receptors) expressions may underlie the increase in anxiety-like behavior in LP offspring. This work represents the first demonstration that BNST developmental plasticity by maternal protein restriction, resulting in fine structural changes and neurochemical alterations that are associated with modified behavioral states.Fundação de Amparo à Pesquisa do Estado de São Paulo (2005/54362-4 and 2013/12486-5) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)info:eu-repo/semantics/publishedVersio