Spatial distribution of atoms in gas-covered Pd-X nanoparticles (X= Ag, Cu, Ni, Pt)

A Monte-carlo (MC) simulation procedure has been developed where the pair bond energies are allowed to take into account the various coordination numbers of surface atoms and the presence of adsorbates. The pair bond energies are calculated from partial bond energies of atoms which, in turn, are calculated from modified tight binding model in the second moment approximation. The model has been applied to study the role of adsorption of hydrogen, oxygen, carbon monoxide and nitric oxide on the surface composition and surface bond geometry of bimetallic Pd-X (X = Ag, Cu, Ni, Pt) nanoparticles having fcc cubo-octahedral geometry with 201, 586, 1289 and 2406 atoms. The results are compared with the known experimental results. Importance of the results in studying reactions on supported bimetallic catalysts has been highlighted.Comment: 15 pages (Latex) + 38 figures (eps

Text Mining for Protein Docking

The rapidly growing amount of publicly available information from biomedical research is readily accessible on the Internet, providing a powerful resource for predictive biomolecular modeling. The accumulated data on experimentally determined structures transformed structure prediction of proteins and protein complexes. Instead of exploring the enormous search space, predictive tools can simply proceed to the solution based on similarity to the existing, previously determined structures. A similar major paradigm shift is emerging due to the rapidly expanding amount of information, other than experimentally determined structures, which still can be used as constraints in biomolecular structure prediction. Automated text mining has been widely used in recreating protein interaction networks, as well as in detecting small ligand binding sites on protein structures. Combining and expanding these two well-developed areas of research, we applied the text mining to structural modeling of protein-protein complexes (protein docking). Protein docking can be significantly improved when constraints on the docking mode are available. We developed a procedure that retrieves published abstracts on a specific protein-protein interaction and extracts information relevant to docking. The procedure was assessed on protein complexes from Dockground (http://dockground.compbio.ku.edu). The results show that correct information on binding residues can be extracted for about half of the complexes. The amount of irrelevant information was reduced by conceptual analysis of a subset of the retrieved abstracts, based on the bag-of-words (features) approach. Support Vector Machine models were trained and validated on the subset. The remaining abstracts were filtered by the best-performing models, which decreased the irrelevant information for ~ 25% complexes in the dataset. The extracted constraints were incorporated in the docking protocol and tested on the Dockground unbound benchmark set, significantly increasing the docking success rate

Design of Face Recognition System Using Viola-Jones and GLD Method

Face recognition systems are the need of time. We have applied de-noising technique and GLD method in conjunction with Viola-Jones, PCA-ANN and achieved recognition rate beyond expectation

Accommodation to Uncomfortable Patterns

Grating patterns can cause discomfort and perceptual distortions. Individuals who experience discomfort and are susceptible to these distortions generally show weaker accommodation than those who are less susceptible. We measured the accommodative response to grating patterns known to differ in the discomfort they evoke because of differences in their colour, motion, or spatial frequency. The parameters known to affect discomfort and distortion had no influence on the mean or variance in the accommodative response, even when accommodative demand was manipulated systematically and the accommodative response varied as expected. </jats:p

Evaluation of the early impacts of the better cotton initiative on smallholder cotton producers in Kurnool District, India: Baseline report

The Better Cotton Standard System is a holistic approach to sustainable cotton production that covers all three pillars of sustainability: environmental, social and economic. The main study research questions is - To what extent has the process of becoming or being certified under BCI sustainability standards had an impact (positive or negative, expected or unexpected) upon smallholders (farmers and households) in Kurnool district? What are the economic (yield, productivity, incomes, food security) and social (child labour, farm workers, no discrimination in wages for women) impacts? In order to be able to measure and attribute impact, but also to understand what has created impact and identify lessons, the study employs a theory based evaluation approach. The baseline and interim performance monitoring rounds of the research have been completed. The end line research is planned in 2018-19

La ocupación solutrense del Abrigo de la Boja (Mula, Murcia, España)

El relleno pleistoceno del Abrigo de la Boja (ADB) empieza con un nivel adscrito al Magdaleniense superior, seguido de un potente paquete con ocupación difusa bajo el cual se desarrolla una secuencia depositada durante el último máximo glacial caracterizada por una serie de estructuras de combustión, de tipo hogar plano/amorfo (open hearth), existiendo también hogares de cubeta. Destaca un hogar enlosado, completo y muy bien conservado, excavado en 2012 y adscrito provisionalmente al Solutreogravetiense. Los niveles solutrenses subyacentes son ricos en elementos de adorno, entre los cuales conchas perforadas de Littorina obtusata y Smaragdia viridis; su industria lítica incluye raspadores, algunas puntas, y escasos buriles. La datación 14C de muestras de carbón de Juniperus sp. sitúa este paquete entre 16990 ± 70 BP (VERA-5364a), a techo, y 20980 ± 120 BP (VERA-5366), a muro. The Pleistocene fill of the La Boja rock shelter (ADB) starts with an Upper Magdalenian level, followed by a thick package with poorly defined occupations under which there is a Last Glacial Maximum sequence with combustion features, mostly of the open hearth type. A particularly well preserved and seemingly complete stone-paved hearth of probable Solutreogravettian age was excavated in 2012. The abundant ornaments in the Solutrean levels include pierced Littorina obtusata and Smaragdia viridis shells and the stone tool assem- blages feature endscrapers, some points and rare burins. The 14C dating of Juniperus sp. charcoal samples places this sequence between 16990 ± 70 BP (VERA-5364a), at the top, and 20980 ± 120 BP (VERA-5366), at the bottom

Monte Carlo study of the effects of system geometry and antiscatter grids on cone-beam CT scatter distributions

Purpose: The proliferation of cone-beam CT (CBCT) has created interest in performance optimization,with x-ray scatter identifie among the main limitations to image quality. CBCT often contends with elevated scatter, but the wide variety of imaging geometry in different CBCT configuration suggests that not all configuration are affected to the same extent. Graphics processing unit (GPU) accelerated Monte Carlo (MC) simulations are employed over a range of imaging geometries to elucidate the factors governing scatter characteristics, effica y of antiscatter grids, guide system design, and augment development of scatter correction. Methods: A MC x-ray simulator implemented on GPU was accelerated by inclusion of variance reduction techniques (interaction splitting, forced scattering, and forced detection) and extended to include x-ray spectra and analytical models of antiscatter grids and flat-pane detectors. The simulator was applied to small animal (SA), musculoskeletal (MSK) extremity, otolaryngology (Head), breast, interventional C-arm, and on-board (kilovoltage) linear accelerator (Linac) imaging, with an axis-todetector distance (ADD) of 5, 12, 22, 32, 60, and 50 cm, respectively. Each configuratio was modeled with and without an antiscatter grid and with (i) an elliptical cylinder varying 70–280 mm in major axis; and (ii) digital murine and anthropomorphic models. The effects of scatter were evaluated in terms of the angular distribution of scatter incident upon the detector, scatter-to-primary ratio (SPR), artifact magnitude, contrast, contrast-to-noise ratio (CNR), and visual assessment. Results: Variance reduction yielded improvements in MC simulation efficien y ranging from ∼17-fold (for SA CBCT) to ∼35-fold (for Head and C-arm), with the most significan acceleration due to interaction splitting (∼6 to ∼10-fold increase in efficien y). The benefi of a more extended geometry was evident by virtue of a larger air gap—e.g., for a 16 cm diameter object, the SPR reduced from 1.5 for ADD = 12 cm (MSK geometry) to 1.1 for ADD = 22 cm (Head) and to 0.5 for ADD = 60 cm (C-arm). Grid efficien y was higher for configuration with shorter air gap due to a broader angular distribution of scattered photons—e.g., scatter rejection factor ∼0.8 for MSK geometry versus ∼0.65 for C-arm. Grids reduced cupping for all configuration but had limited improvement on scatterinduced streaks and resulted in a loss of CNR for the SA, Breast, and C-arm. Relative contribution of forward-directed scatter increased with a grid (e.g., Rayleigh scatter fraction increasing from ∼0.15 without a grid to ∼0.25 with a grid for the MSK configuration) resulting in scatter distributions with greater spatial variation (the form of which depended on grid orientation). Conclusions: A fast MC simulator combining GPU acceleration with variance reduction provided a systematic examination of a range of CBCT configuration in relation to scatter, highlighting the magnitude and spatial uniformity of individual scatter components, illustrating tradeoffs in CNR and artifacts and identifying the system geometries for which grids are more beneficia (e.g., MSK) from those in which an extended geometry is the better defense (e.g., C-arm head imaging). Compact geometries with an antiscatter grid challenge assumptions of slowly varying scatter distributions due to increased contribution of Rayleigh scatter.The research was supported by academic-industry partnership with Carestream Health Inc. (Rochester, NY) and National Institutes of Health (NIH) Grant No. 2R01-CA-112163. A. Sisniega is supported by FPU grant (Spanish Ministry of Education), AMIT project, RECAVA-RETIC Network, Project Nos. TEC2010-21619- C04-01, TEC2011-28972-C02-01, and PI11/00616 (Spanish Ministry of Science and Education), ARTEMIS program (Comunidad de Madrid), and PreDiCT-TB partnership.Publicad