A support property for infinite dimensional interacting diffusion processes

The Dirichlet form associated with the intrinsic gradient on Poisson space is known to be quasi-regular on the complete metric space $\ddot\Gamma=$ $\{Z_+$-valued Radon measures on \IR^d\}. We show that under mild conditions, the set $\ddot\Gamma\setminus\Gamma$ is \e-exceptional, where $\Gamma$ is the space of locally finite configurations in \IR^d, that is, measures $\gamma\in\ddot\Gamma$ satisfying \sup_{x\in\IR^d}\gamma(\{x\})\leq 1. Thus, the associated diffusion lives on the smaller space $\Gamma$. This result also holds for Gibbs measures with superstable interactions.Comment: French title: Une propri\'et\'e de support pour des processus de diffusion en dimension infinie avec interactio

Spá:A Web-Based Viewer for Text Mining in Evidence Based Medicine

Summarizing the evidence about medical interventions is an immense undertaking, in part because unstructured Portable Document Format (PDF) documents remain the main vehicle for disseminating sci- entific findings. Clinicians and researchers must therefore manually ex- tract and synthesise information from these PDFs. We introduce Spá,12 a web-based viewer that enables automated annotation and summari- sation of PDFs via machine learning. To illustrate its functionality, we use Spá to semi-automate the assessment of bias in clinical trials. Spá has a modular architecture, therefore the tool may be widely useful in other domains with a PDF-based literature, including law, physics, and biology

Is Our World Going to Get a Whole Lot Smaller?

The surge of oil prices in recent years has led to speculation that rising transportation costs could end the period of dramatic world trade growth — in the words of Rubin (2009), “…Your world is going to get a whole lot smaller.” Using data from China’s Customs Statistics, we examine the impact of oil prices on trade’s sensitivity to distance. We find that higher oil prices increase trade’s elasticity to distance, but that the economic effect is small. We also find that the effect is more pronounced for trade within global production networks, and less large for goods shipped by air.oil prices, distance, trade, vertical specialization, mode of transport, China,

Bayesian accrual prediction for interim review of clinical studies: open source R package and smartphone application

Illustration of use of R accrual package. (DOCX 917 kb

Biochemical analysis of TssK, a core component of the bacterial Type VI secretion system, reveals distinct oligomeric states of TssK and identifies a TssK–TssFG subcomplex

Gram-negative bacteria use the Type VI secretion system (T6SS) to inject toxic proteins into rival bacteria or eukaryotic cells. However, the mechanism of the T6SS is incompletely understood. In the present study, we investigated a conserved component of the T6SS, TssK, using the antibacterial T6SS of Serratia marcescens as a model system. TssK was confirmed to be essential for effector secretion by the T6SS. The native protein, although not an integral membrane protein, appeared to localize to the inner membrane, consistent with its presence within a membrane-anchored assembly. Recombinant TssK purified from S. marcescens was found to exist in several stable oligomeric forms, namely trimer, hexamer and higher-order species. Native-level purification of TssK identified TssF and TssG as interacting proteins. TssF and TssG, conserved T6SS components of unknown function, were required for T6SS activity, but not for correct localization of TssK. A complex containing TssK, TssF and TssG was subsequently purified in vitro, confirming that these three proteins form a new subcomplex within the T6SS. Our findings provide new insight into the T6SS assembly, allowing us to propose a model whereby TssK recruits TssFG into the membrane-associated T6SS complex and different oligomeric states of TssK may contribute to the dynamic mechanism of the system

Many-body approach to proton emission and the role of spectroscopic factors

The process of proton emission from nuclei is studied by utilizing the two-potential approach of Gurvitz and Kalbermann in the context of the full many-body problem. A time-dependent approach is used for calculating the decay width. Starting from an initial many-body quasi-stationary state, we employ the Feshbach projection operator approach and reduce the formalism to an effective one-body problem. We show that the decay width can be expressed in terms of a one-body matrix element multiplied by a normalization factor. We demonstrate that the traditional interpretation of this normalization as the square root of a spectroscopic factor is only valid for one particular choice of projection operator. This causes no problem for the calculation of the decay width in a consistent microscopic approach, but it leads to ambiguities in the interpretation of experimental results. In particular, spectroscopic factors extracted from a comparison of the measured decay width with a calculated single-particle width may be affected.Comment: 17 pages, Revte

A curriculum to teach medical students to care for people with disabilities: development and initial implementation

<p>Abstract</p> <p>Background</p> <p>Lack of knowledge and skills, and negative attitudes towards patients with disabilities, may adversely affect the services available to this group and negatively affect their health outcomes. The objective of this paper is to describe the development and initial implementation of a curriculum for teaching medical students to care for patients with disabilities.</p> <p>Methods</p> <p>We followed the six-step approach for developing curricula for medical education: general needs assessment, specific needs assessment, defining goals and objectives, determining the educational strategies, planning the implementation, and developing an evaluation plan.</p> <p>Results</p> <p>The curriculum has well defined goals and objectives covering knowledge, attitudes and skills. It employs both traditional and non-traditional teaching strategies. The implementation is planned over the four-year medical school curriculum in collaboration with a number of academic departments and specialized community-based agencies. The curriculum evaluation includes an attitudinal survey which is administered using a controlled design (pre- and post- exposure to the curriculum). The initial implementation of the curriculum has been very successful.</p> <p>Conclusion</p> <p>We have developed a longitudinal curriculum to teach medical students to care for people with disabilities. A rigorous evaluation of the impact of the curriculum is needed.</p

A biophysical model of cell adhesion mediated by immunoadhesin drugs and antibodies

A promising direction in drug development is to exploit the ability of natural killer cells to kill antibody-labeled target cells. Monoclonal antibodies and drugs designed to elicit this effect typically bind cell-surface epitopes that are overexpressed on target cells but also present on other cells. Thus it is important to understand adhesion of cells by antibodies and similar molecules. We present an equilibrium model of such adhesion, incorporating heterogeneity in target cell epitope density and epitope immobility. We compare with experiments on the adhesion of Jurkat T cells to bilayers containing the relevant natural killer cell receptor, with adhesion mediated by the drug alefacept. We show that a model in which all target cell epitopes are mobile and available is inconsistent with the data, suggesting that more complex mechanisms are at work. We hypothesize that the immobile epitope fraction may change with cell adhesion, and we find that such a model is more consistent with the data. We also quantitatively describe the parameter space in which binding occurs. Our results point toward mechanisms relating epitope immobility to cell adhesion and offer insight into the activity of an important class of drugs.Comment: 13 pages, 5 figure

A Cooperative Coevolution Framework for Parallel Learning to Rank

Abstract—We propose CCRank, the first parallel framework for learning to rank based on evolutionary algorithms (EA), aiming to significantly improve learning efficiency while maintaining accuracy. CCRank is based on cooperative coevolution (CC), a divide-and-conquer framework that has demonstrated high promise in function optimization for problems with large search space and complex structures. Moreover, CC naturally allows parallelization of sub-solutions to the decomposed sub-problems, which can substantially boost learning efficiency. With CCRank, we investigate parallel CC in the context of learning to rank. We implement CCRank with three EA-based learning to rank algorithms for demonstration. Extensive experiments on benchmark datasets in comparison with the state-of-the-art algorithms show the performance gains of CCRank in efficiency and accuracy. Index Terms—Cooperative coevolution, learning to rank, information retrieval, genetic programming, immune programming Ç

Crystal structure of rhodopsin in complex with a mini-G_o sheds light on the principles of G protein selectivity

Selective coupling of G protein (heterotrimeric guanine nucleotide–binding protein)–coupled receptors (GPCRs) to specific Gα-protein subtypes is critical to transform extracellular signals, carried by natural ligands and clinical drugs, into cellular responses. At the center of this transduction event lies the formation of a signaling complex between the receptor and G protein. We report the crystal structure of light-sensitive GPCR rhodopsin bound to an engineered mini-Go protein. The conformation of the receptor is identical to all previous structures of active rhodopsin, including the complex with arrestin. Thus, rhodopsin seems to adopt predominantly one thermodynamically stable active conformation, effectively acting like a “structural switch,” allowing for maximum efficiency in the visual system. Furthermore, our analysis of the well-defined GPCR–G protein interface suggests that the precise position of the carboxyl-terminal “hook-like” element of the G protein (its four last residues) relative to the TM7/helix 8 (H8) joint of the receptor is a significant determinant in selective G protein activation