265 research outputs found
Continuous dependence estimate for a degenerate parabolic-hyperbolic equation with Levy noise
In this article, we are concerned with a multidimensional degenerate
parabolic-hyperbolic equation driven by Levy processes. Using bounded variation
(BV) estimates for vanishing viscosity approximations, we derive an explicit
continuous dependence estimate on the nonlinearities of the entropy solutions
under the assumption that Levy noise depends only on the solution. This result
is used to show the error estimate for the stochastic vanishing viscosity
method. In addition, we establish fractional BV estimate for vanishing
viscosity approximations in case the noise coefficients depend on both the
solution and spatial variable.Comment: 31 Pages. arXiv admin note: text overlap with arXiv:1502.0249
Monogamy of quantum correlations reveals frustration in a quantum Ising spin system: Experimental demonstration
We report a nuclear magnetic resonance experiment, which simulates the
quantum transverse Ising spin system in a triangular configuration and further
show that the monogamy of quantum correlations can be used to distinguish
between the frustrated and non-frustrated regimes in the ground state of this
system. Adiabatic state preparation methods are used to prepare the ground
states of the spin system. We employ two different multipartite quantum
correlation measures to analyze the experimental ground state of the system in
both the frustrated and non-frustrated regimes. In particular, we use
multipartite quantum correlation measures generated by monogamy considerations
of negativity, a bipartite entanglement measure, and that of quantum discord,
an information-theoretic quantum correlation measure. As expected from
theoretical predictions, the experimental data confirm that the non-frustrated
regime shows higher multipartite quantum correlations compared to the
frustrated one.Comment: Title in the published version is "Multipartite quantum correlations
reveal frustration in a quantum Ising spin system", 7 pages, 4 figure
Three different interlocking intramedullary nails for unstable reverse oblique inter-trochanteric fractures: a bio-mechanical comparative study
Background: Biomechanical testing, intramedullary devices have proven advantageous over the extramedullary devices in the management of unstable intertrochanteric fractures. Reverse oblique type of intertrochanteric fractures are highly unstable and intramedullary nails are currently the method of internal fixation. The currently available nails seems to provide rotational, axial and angular stability, but biomechanical analysis of the strain pattern in the bone and implant in this fractures are lacking. The aim of this experimental study was to analyse the strain in three different long femoral nail-bone units under physiological loading when implanted in Saw bone model after creating a reverse oblique intertrochanteric fracture.Methods: A total of 12 sawbones were divided in to 4 equal groups. Group 1 was intact saw bones and were used as controls. Group 2, Group 3 and Group 4 were implanted with Depuy, Stryker and Synthes nails respectively after creating a reverse oblique intertrochanteric fracture. All the four groups were axially loaded with 100 N increments until physiological loads. The strain patterns were measured at the posteromedial cortex and the peak strains were extracted at partial weight bearing i.e. 500 N and full weight bearing physiological loads i.e. 1000 N.Results: There was no significant difference in peak strains among the groups at partial loads. However at 1000 N loads the peak strain in the DePuy nail-bone unit was significantly high compared to the other two nail-bone units and the controls. Conclusions: These results question the safety of immediate full weight bearing following surgery when treating the reverse oblique unstable fractures with DePuy intramedullary nails. A period of partial weight bearing following fixation of reverse oblique fractures would be wise when using DePuy nails
Expression pattern and regulation of genes differ between fibroblasts of adhesion and normal human peritoneum
BACKGROUND: Injury to the peritoneum during surgery is followed by a healing process that frequently results in the attachment of adjacent organs by a fibrous mass, referred commonly as adhesions. Because injuries to the peritoneum during surgery are inevitable, it is imperative that we understand the mechanisms of adhesion formation to prevent its occurrence. This requires thorough understanding of the molecular sequence that results in the attachment of injured peritoneum and the development of fibrous tissue. Recent data show that fibroblasts from the injured peritoneum may play a critical role in the formation of adhesion tissues. Therefore, identifying changes in gene expression pattern in the peritoneal fibroblasts during the process may provide clues to the mechanisms by which adhesion develop. METHODS: In this study, we compared expression patterns of larger number of genes in the fibroblasts isolated from adhesion and normal human peritoneum using gene filters. Contributions of TGF-beta1 and hypoxia in the altered expression of specific genes were also examined using a semiquantitative RT-PCR technique. RESULTS: Results show that several genes are differentially expressed between fibroblasts of normal and adhesion peritoneum and that the peritoneal fibroblast may acquire a different phenotype during adhesion formation. Genes that are differentially expressed between normal and adhesion fibroblasts encode molecules involved in cell adhesion, proliferation, differentiation, migration and factors regulating cytokines, transcription, translation and protein/vesicle trafficking. CONCLUSIONS: Our data substantiate that adhesion formation is a multigenic phenomenon and not all changes in gene expression pattern between normal and adhesion fibroblasts are the function of TGF-beta1 and hypoxia that are known to influence adhesion formation. Analysis of the gene expression data in the perspective of known functions of genes connote to additional targets that may be manipulated to inhibit adhesion development
PPIcons: identification of protein-protein interaction sites in selected organisms
The physico-chemical properties of interaction interfaces have a crucial role in characterization of protein–protein interactions (PPI). In silico prediction of participating amino acids helps to identify interface residues for further experimental verification using mutational analysis, or inhibition studies by screening library of ligands against given protein. Given the unbound structure of a protein and the fact that it forms a complex with another known protein, the objective of this work is to identify the residues that are involved in the interaction. We attempt to predict interaction sites in protein complexes using local composition of amino acids together with their physico-chemical characteristics. The local sequence segments (LSS) are dissected from the protein sequences using a sliding window of 21 amino acids. The list of LSSs is passed to the support vector machine (SVM) predictor, which identifies interacting residue pairs considering their inter-atom distances. We have analyzed three different model organisms of Escherichia coli, Saccharomyces Cerevisiae and Homo sapiens, where the numbers of considered hetero-complexes are equal to 40, 123 and 33 respectively. Moreover, the unified multi-organism PPI meta-predictor is also developed under the current work by combining the training databases of above organisms. The PPIcons interface residues prediction method is measured by the area under ROC curve (AUC) equal to 0.82, 0.75, 0.72 and 0.76 for the aforementioned organisms and the meta-predictor respectively. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00894-013-1886-9) contains supplementary material, which is available to authorized users
Political prisoners in India, 1920-1977.
This is a study of the politics of 'political prisonerhood' in colonial and independent India. Prison going and the struggles inside the prison had, with the nationalist culture of jail going in the early part of the twentieth century become an integral part of the protest against the colonial state. Imprisonment in its multifarious forms also became the major bulwark of the colonial state's strategy for harnessing recalcitrant subjects. The purpose of this thesis is to examine the process by which the notion of 'political' became a festering issue in the contest between the colonial state and the subject population and later between the state in independent India and the various 'rebel' groups, and also the manner in which the ruling classes assumed the sole responsibility of defining the 'political'. We have confined our study to the peaks of nationalist resistance against the colonial state and popular struggles against the dominant classes in independent India. Through this exploration of the notion of political prisonerhood we also attempt to understand the permanence and ruptures in the forms of repression and the nature of penal sanctions which the state deployed against its political opponents in colonial and independent India. In order to understand what constitutes 'political crime', and who were or were not recognized as 'political prisoners' at a particular historical moment, we have examined the role of the ideological discourses which informed penal regimes in colonial and independent India. The theoretical premises and conceptual tools in this study bear the influence of the Marxist studies on Indian politics and the Subaltern school's understanding of Indian history. The material for research has been drawn from various official and unofficial sources viz., archival records of the colonial government and the government of independent India, reports on prisons by various governmental committees, jail manuals, rules, regulations, laws, autobiographies, biographies, prison memoirs, prison diaries and interviews with erstwhile political prisoners
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