132,320 research outputs found
Nanostructured gradient Co-Sn electrodeposits as alternative to Sn connector contacts
No full textAbstract not availableE.P. Georgiou, J.G. Buijnsters, H. Wang, D. Drees, A.K. Basak, J.-P. Celi
NEITHER AT SEA NOR ASHORE : THE ABANDONED CREW OF THE OBO BASAK
No full textSOMMAIRE Le but de cet article est de rendre compte des conditions de vie et de travail des marins abandonnés par l'étude d'un cas particulier -celui de ABSTRACT The aim of this paper is to document the living and working conditions of abandoned seafarers by focusing on one particular case -the Obo Basak. The paper provides rich and detailed information on the conditions of abandoned seafarers for practitioners, policy makers and seafarer welfare organisations. The paper begins with a brief description of recent regulatory developments directed at addressing the problem of abandoned seafarers. The experiences of the Obo Basak crew during their nine month period of abandonment in Dunkirk are then documented in chronological order. In doing this, the individual circumstances of the seafarers who were involved are highlighted and special attention is paid to social relations on board. The paper also demonstrates the legal complexity involved in dealing with abandonment cases as well as the devastating impact of the abandonment on the seafarer families. The events of this case and the experiences of the seafarers on the Obo Basak are relatively typical of the many cases of abandonment that occur worldwide
Lower bounds for regular genus and gem-complexity of PL 4-manifolds
No full textWithin crystallization theory, two interesting PL invariants for d-manifolds have been introduced and studied, namely, gem-complexity and regular genus. In the present paper we prove that for any closed connected PL 4-manifold M, its gem-complexity k(M) and its regular genus G(M) satisfy
k(M)≥3χ(M)+10m−6 and G(M)≥2χ(M)+5m−4,
where rk(π1(M))=m. These lower bounds enable to strictly improve previously known estimations for regular genus and gem-complexity of product 4-manifolds. Moreover, the class of semi-simple crystallizations is introduced, so that the represented PL 4-manifolds attain the above lower bounds. The additivity of both gem-complexity and regular genus with respect to connected sum is also proved for such a class of PL 4-manifolds, which comprehends all ones of “standard type”, involved in existing crystallization catalogs, and their connected sums
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Stability in distribution and volume nullification of Levy flow
No full textWe continue our study, Basak and Kannan [3], of Hasminskii's almost sure stability in large of one-dimensional nonsingular diffusions; extending it now to the volume nullification property of a d-dimensional Levy flow (singular or nonsingular). The proof in [3] is extended to account for the jump nature of a Levy process. We first show the stability in distribution. Some moment estimates of the Jacobian matrix of the Levy flow are the technical results established next. These are used to prove the volume- and covolume-nullification properties of the Levy how. We recover the main stability results in [1], [2], and [3] as special cases
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
THE ACTIVATION MECHANISM OF RHODOPSIN EXPLORED BY MULTISCALE METHODS
No full textRhodopsin is the best characterized member of the large, pharmaceutically important, family of G-protein-coupled receptors (GPCRs), and serves as a prototype for understanding GPCR activation. In this thesis, we aim at understanding the activation mechanism of rhodopsin. To this aim, we first performed an in-depth analysis of the conformational motions of rhodopsin predicted by two elastic network models, Gaussian Network Model (GNM) and Anisotropic Network Model (ANM). We compared these motions with the extensive amount of experimental data, and developed a model for rhodopsin activation. We tested the model with Meta II fluorescence decay rates measured to characterize the deactivation of rhodopsin mutants. We find that our results correctly predict 93% of the experimentally observed effects in 119 rhodopsin mutants for which the decay rates and misfolding data were measured, including a systematic analysis of Cys->Ser replacements. Next, in order to incorporate atomic details and the effects of membrane and water molecules into our model, we developed a new protocol named ANM-restrained molecular dynamics (MD). In this protocol, we used multiple ANM modes as restraints to guide MD simulations. By using this protocol, we were able to sample biologically relevant, large scale motions of the protein that are otherwise not accessible to the conventional timescales MD simulations. Furthermore, we explored the evolution of the multiple ANM global modes with realistic deformations favored by a detailed atomic force field in the presence of the explicit environment. Remarkably, with this method, we identify a highly hinge site, which does not change with several rounds of applying normal modes as restraints. This hinge site includes residues that are directly affected by the isomerization of retinal, as well as those stabilizing the resulting all-trans conformation of the chromophore. The CP ends of the helices H3, H4, H5, and H6 and the connecting loops are found to enjoy an enhanced mobility facilitated by this hinge site. Several new interactions are observed to contribute to the mechanism of signal propagation from the retinal binding pocket to the G-protein binding sites in the CP domain
Comparison of seropositivity of human immunodeficiency virus, hepatitis B virus, hepatitis C virus, and syphilis among Hospital Cornea Retrieval Programme-Donors versus voluntary cornea donors at a large eye bank in Eastern India
No full textPurpose: To compare the serology profile of donors from Hospital Cornea Retrieval Programme-donors (HCRP-D) and voluntary cornea donors (VC-D) from a large eye bank in Eastern India. Methods: This is a retrospective analysis of donor details from January 2011 to December 2016. Donor demographics, cause of death, and serology reports were compiled. Postmortem blood was tested for human immunodeficiency virus 1 and 2 (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), and syphilis using government-approved kits as per the National Programme for Control of Blindness Standards of Eye Banking. Donors for whom serology was not possible were excluded. Results: A total of 4300 of 4353 donors were included of which 74.3% were hospital donors and 25.7% were voluntary donors. A total of 93 (2.2%) donors with 94 seropositive reports were noted: 79 (84.9%) from HCRP-D and 14 (15.1%) from VC-D which was statistically significantly higher (P = 0.02). Among seropositive reports, HIV, HBV, HCV, and syphilis accounted for 12 (12.8%), 38 (40.4%), 36 (38.3%), and eight (8.5%), respectively. There was no correlation between the cause of death and seropositivity. A statistically significant decreasing trend in seroprevalence among hospital donors was observed over the years (5.3% in 2011 to 1.4% in 2016; P = 0.004). Two (0.47%) of 421 hospital donors with prior negative serology were found to be seropositive. Conclusion: Seropositive rates are significantly higher among hospital donors in spite of medical prescreening compared to nonscreened voluntary donors. Serology should be repeated even when prior reports are available
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