2,304 research outputs found
On co-authorship for author disambiguation
No full textAuthor name disambiguation deals with clustering the same-name authors into different individuals. To attack the problem, many studies have employed a variety of disambiguation features such as coauthors, titles of papers/publications, topics of articles, emails/affiliations, etc. Among these, co-authorship is the most easily accessible and influential, since inter-person acquaintances represented by co-authorship could discriminate the identities of authors more clearly than other features. This study attempts to explore the net effects of co-authorship on author clustering in bibliographic data. First, to handle the shortage of explicit coauthors listed in known citations, a web-assisted technique of acquiring implicit coauthors of the target author to be disambiguated is proposed. Then, a coauthor disambiguation hypothesis that the identity of an author can be determined by his/her coauthors is examined and confirmed through a variety of author disambiguation experiments. (C) 2008 Elsevier Ltd. All rights reserved.X1174sciescopu
The distance-regular graphs such that all of its second largest local eigenvalues are at most one
No full textIn this paper, we classify distance-regular graphs such that all of its second largest local eigenvalues are at most one. Also we discuss the consequences for the smallest eigenvalue of a distance-regular graph. These extend a result by the first author, who classified the distance-regular graphs with smallest eigenvalue -1 - b(1)/2. (C) 2011 Elsevier Inc. All rights reserved.X1154sciescopu
On geometric distance-regular graphs with diameter three
Full text linkIn this paper we study distance-regular graphs with intersection array {(t + 1)s. ts. (t - 1)(s + 1 - psi); 1, 2, (t + 1)psi} (1) where s. t. psi are integers satisfying t >= 2 and 1 = 2, there are only finitely many distance-regular graphs of order (s, t) with mallest eigenvalue -t -1, diameter D = 3 and intersection number c(2) = 2 except for Hamming graphs with diameter three. Moreover, we will show that if a distance-regular graph with intersection array (1) for t = 2 exists then (s, psi) = (15, 9). As Gavrilyuk and Makhnev (2013)[9] proved that the case (s, psi) = (15, 9) does not exist, this enables us to finish the classification of geometric distance-regular graphs with smallest eigenvalue -3, diameter D >= 3 and c(2) >= 2 which was started by the first author (Bang, 2013)[1]. (C) 2013 Elsevier Ltd. All rights reserved.X1121Ysciescopu
Capsule-like voids in SiC single crystal: Phase contrast imaging and computer simulations
No full textThe results of observation of capsule-like voids in silicon carbide (6H-SiC) single crystal by means of a phase contrast imaging technique with synchrotron radiation at the Pohang Light Source as well as computer simulations of such images are presented. A pink beam and a monochromated beam were used. The latter gives more pronounced images but they still are smoothed due to a finite detector resolution and the spatial coherence of the beam. Sizes and a structure of far field images are different from these of the objects. The computer simulations allow us to reproduce a shape and a size of the capsule-like void. (C) 2014 Author(s).open1111sciescopu
N = 8 superconformal Chern-Simons theories
Full text linkA Lagrangian description of a maximally supersymmetric conformal field theory in three dimensions was constructed recently by Bagger and Lambert (BL). The BL theory has SO(4) gauge symmetry and contains scalar and spinor fields that transform as 4-vectors. We verify that this theory has OSp(8|4) superconformal symmetry and that it is parity conserving despite the fact that it contains a Chern-Simons term. We describe several unsuccessful attempts to construct theories of this type for other gauge groups and representations. This experience leads us to conjecture the uniqueness of the BL theory. Given its large symmetry, we expect this theory to play a significant role in the future development of string theory and M-theory
Prenatal Sex Determination and Sex-Selective Abortion in Rural Central China
No full textThis study analyzes the practice of prenatal sex selection in rural central China. It examines the prevalence and determinants of prenatal sex determination by ultrasound scanning and subsequent sex-selective abortion. The data are derived from a survey of 820 married women aged 20-44 and from in-depth interviews with rural women and men, village leaders, family planning managers, and health providers, conducted by the author in one county in central China in 2000. Prenatal sex determination was a widespread practice, especially for second and higher-order pregnancies. Sex-selective abortion was prevalent and order of pregnancy, sex of fetus, and sex of previous children were major determinants of the practice. A female fetus representing a high-order pregnancy in a family with one or more daughters was the most likely to be aborted. Awareness among rural families that in the population at large a future marriage squeeze was likely did not diminish the demand for sex-selective abortion. Copyright 2001 by The Population Council, Inc..
Cospectral graphs and the generalized adjacency matrix
No full textLet J be the all-ones rnatrix, and let A denote the adjacency matrix of a graph. An old result of Johnson and Newman states that if two graphs are cospectral with respect to yJ - A for two distinct values of y, then they are cospectral for all y. Here we will focus on graphs cospectral with respect to yJ - A for exactly one value (y) over cap of (y) over cap. We call such graphs (y) over cap -cospectral. It follows that is a rational number, and we prove existence of a pair of (y) over cap -cospectral graphs for every rational. In addition, we generate by computer all (y) over cap -cospectral pairs on at most nine vertices. Recently, Chesnokov and the second author constructed pairs of (y) over cap -cospectral graphs for all rational (y) over cap is an element of (0, 1), where one graph is regular and the other one is not. This phenomenon is only possible for the mentioned values of, and by computer we find all Such pairs of (y) over cap -cospectral graphs on at most eleven vertices. (C) 2006 Elsevier Inc. All rights reserved.X1116sciescopu
Diatom frustule silica extracted from Melosira nummuloides ameliorates acetaminophen-induced acute liver injury in mice
No full textMelosira nummuloides is a type of diatom in the family Melosiraceae. Diatoms are unicellular microalgae widely distributed in aquatic environments. Diatoms are known to be suitable for many industrial and biomedical applications because of their high biocompatibility and ease of use. In this study, we investigated the hepatoprotective effect of diatom frustule silica (DFS) extracted from Melosira nummuloides on hepatotoxicant-induced liver injury. Hepatoprotective effects of DFS were examined using acetaminophen-induced acute liver injury (ALI) mouse model. We evaluated the hepatoprotective effects through hepatotoxicity, pro-inflammatory cytokines, transcriptional factors, upstream signaling pathways, and histopathological analysis by DFS in an animal model of acetaminophen-induced ALI. Our results showed serum alanine aminotransferase/aspartate aminotransferase activity and hepatic malondialdehyde formation were significantly attenuated upon DFS administration. DFS also ameliorated glutathione depletion and down-regulated acetaminophen-induced CYP2E1. DFS administration also down-regulated expressions of pro-inflammatory cytokines through preventing NF-κB activation by JNK1/2 phosphorylation inhibition. These findings demonstrate that the hepatoprotective effect of DFS is associated with suppression of inflammatory responses in an animal model of acetaminophen-induced ALI. © 2022, The Author(s)
Head and trunk movement strategies in quiet stance : from the deficit of vestibular loss to the expertise of tightrope walkers via prosthetic feedback
Full text linkIs the head more locked to the trunk or stabilised in space during quite stance? Does prosthetic vestibular feedback have a positive impact on movement strategies and muscle synergies of those with vestibular loss? Does training in tandem stance lead to improved movement strategies and/or reweighting of sensory inputs? These questions have not been answered to date. This thesis attempted to answer these questions with appropriate, but new, techniques. The coordination of the head with respect to the trunk and pelvis during quiet, feet side by side, stance in normal and vestibular loss subjects was examined as well as the effect of prosthetic feedback on the strategies and synergies used by vestibular loss subjects. Changes in movement strategies and sensory feedback in tight-rope walkers with considerable training in tandem stance (one foot before the other), were also investigated.
Subjects performed the stance tasks under different sensory conditions: with eyes open or closed, and on either a firm or foam surface. Stance was either side by side stance or tandem stance. For one experiment, vibrotactile and auditory balance feedback of trunk sway was used in addition. Subject groups were bilateral vestibular loss (BVL) patients, trained tightrope walkers and age matched controls. Two further groups of young and elderly healthy subjects were used to characterise differences in head movements with aging. In all studies roll and pitch angular velocities were recorded with six body-worn gyroscopes; a set of two worn at the upper trunk, an identical set at the hips and another lighter set worn on a head band. In one study with BVL subjects, another of the lighter gyroscopes was strapped onto the lower leg. For the balance feedback study surface EMGs were recorded from pairs of antagonistic muscles at the lower leg, trunk and upper arm. Data from all experiments was analysed in both time and frequency domains. For the analysis of tandem stance an estimate of centre of mass movement was calculated as well as its time to reach a virtual stability boundary.
The results indicated that under most sensory conditions, two legged, feet side by side stance conditions, head sway at the head for both the roll and pitch direction is greater than at the upper trunk and the pelvis. For low and mid-frequencies (<0.3 Hz) the head is locked to the trunk i.e. there is a tendency for the head and trunk to move as one unit but the head movement is always more than expected from a pure inverted pendulum movement mode. For the BVL subjects the head on trunk locking is more rigid and characterized by higher resonant frequencies. Prosthetic feedback reduced pelvis sway angle displacements in BVL subjects to values of age-matched healthy controls for all stance tasks. Movement strategies in BVL subjects were reduced in amplitudes with feedback but otherwise not changed. Reduced amplitudes are achieved with improved antagonistic muscle synergies. As we observed with feet side by side stance, tandem stance is also multisegmental. Keeping balance while standing on a tightrope appears to require similar intersegmental movement strategies for the head, trunk and pelvis to those used with other, less difficult tandem stance tasks. The difference with respect to untrained normal subjects is that faster trunk movements are used by tightrope walkers as they explore the limits of the base of support. At the same time they reduce relative head and pelvis movements to those of the trunk via changed proprioceptive weightings
Mediators of leukocyte yctivation play a role in disseminated intravascular coagulation during orthotopic liver transplantation
Full text linkLeukocytes play an important role in the development of disseminated intravascular coagulation (DIC). In the reperfusion phase of OLT a DIC-like situation has been described and has been held responsible for the high blood loss during this phase.
We investigated the role of leukocytes in the pathogenesis of DIC in OLT by measuring the leukocytic mediators released upon activation (cathepsin B, elastase, TNF, neopterin) and the levels of thrombin-antithrombin III (TAT) complexes, seen as markers of prothrombin activation. Arterial blood samples were taken at 10 different time points during and after OLT. Samples were also taken of the perfusate released from the liver graft vein during the flushing procedure before the reperfusion phase. Aprotinin was given as a continuous infusion (0.2-0.4 Mill. KlU/hr) and its plasma levels were determined.
Significantly elevated levels of neopterin (15-fold; P<0.01), cathepsin B (440-fold; P<0.01) in the perfusate, as compared with the systemic circulation, as well as their significant increases in the early reperfusion phase suggested that they were released by the graft liver. This was paralleled by elevated levels of elastase (1.3-fold, P<0.05), TNF (1.5-fold, P=NS), and TAT complexes (1.4-fold; P<0.1) in the perfusate. Significant correlations could be identified between the parameters of leukocyte activation and TAT complexes, whereas no correlation was observed between any of the parameters investigated and the aprotinin levels.
Our results strongly indicate a release of leukocytic mediators from the graft liver during its reperfusion which seems to be related to the parallely increased prothrombin activation. No correlation could be seen between levels of aprotinin and levels of leukocytic mediators
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