206,773 research outputs found

    Mining electron density for functionally relevant protein polysterism in crystal structures.

    Get PDF
    This review focuses on conceptual and methodological advances in our understanding and characterization of the conformational heterogeneity of proteins. Focusing on X-ray crystallography, we describe how polysterism, the interconversion of pre-existing conformational substates, has traditionally been analyzed by comparing independent crystal structures or multiple chains within a single crystal asymmetric unit. In contrast, recent studies have focused on mining electron density maps to reveal previously 'hidden' minor conformational substates. Functional tests of the importance of minor states suggest that evolutionary selection shapes the entire conformational landscape, including uniquely configured conformational substates, the relative distribution of these substates, and the speed at which the protein can interconvert between them. An increased focus on polysterism may shape the way protein structure and function is studied in the coming years

    Neuroimaging of structural pathology and connectomics in traumatic brain injury: Toward personalized outcome prediction.

    Get PDF
    Recent contributions to the body of knowledge on traumatic brain injury (TBI) favor the view that multimodal neuroimaging using structural and functional magnetic resonance imaging (MRI and fMRI, respectively) as well as diffusion tensor imaging (DTI) has excellent potential to identify novel biomarkers and predictors of TBI outcome. This is particularly the case when such methods are appropriately combined with volumetric/morphometric analysis of brain structures and with the exploration of TBI-related changes in brain network properties at the level of the connectome. In this context, our present review summarizes recent developments on the roles of these two techniques in the search for novel structural neuroimaging biomarkers that have TBI outcome prognostication value. The themes being explored cover notable trends in this area of research, including (1) the role of advanced MRI processing methods in the analysis of structural pathology, (2) the use of brain connectomics and network analysis to identify outcome biomarkers, and (3) the application of multivariate statistics to predict outcome using neuroimaging metrics. The goal of the review is to draw the community's attention to these recent advances on TBI outcome prediction methods and to encourage the development of new methodologies whereby structural neuroimaging can be used to identify biomarkers of TBI outcome

    Evaluation of the main achievements of cohesion policy programmes and projects over the longer term in 15 selected regions (from 1989-1993 programme period to the present)

    Get PDF
    Against a background of inconclusive evidence of the results of EU Cohesion policy since 1989, the aim of this study has been to evaluate the main achievements of EU Cohesion policy programmes and projects and their effectiveness and utility over the longer term in 15 selected regions of the EU15. Specifically, the main objectives of the study were twofold: (i) to examine the achievements of all programmes co-financed by the ERDF and, where applicable, the Cohesion Fund, which have been implemented in the 15 selected regions from 1989 to 2012 (regional programmes and national programmes implemented in the regions); and (ii) to assess the relevance of programmes and the effectiveness and utility of programme achievement

    ATLBS: the Australia Telescope Low-brightness Survey

    Get PDF
    We present a radio survey carried out with the Australia Telescope Compact Array. A motivation for the survey was to make a complete inventory of the diffuse emission components as a step towards a study of the cosmic evolution in radio source structure and the contribution from radio-mode feedback on galaxy evolution. The Australia Telescope low-brightness survey (ATLBS) at 1388 MHz covers 8.42 sq deg of the sky in an observing mode designed to yield images with exceptional surface brightness sensitivity and low confusion. The ATLBS radio images, made with 0.08 mJy/beam rms noise and 50" beam, detect a total of 1094 sources with peak flux exceeding 0.4 mJy/beam. The ATLBS source counts were corrected for blending, noise bias, resolution, and primary beam attenuation; the normalized differential source counts are consistent with no upturn down to 0.6 mJy. The percentage integrated polarization Pi_0 was computed after corrections for the polarization bias in integrated polarized intensity; Pi_0 shows an increasing trend with decreasing flux density. Simultaneous visibility measurements made with longer baselines yielded images, with 5" beam, of compact components in sources detected in the survey. The observations provide a measurement of the complexity and diffuse emission associated with mJy and sub-mJy radio sources. 10% of the ATLBS sources have more than half of their flux density in extended emission and the fractional flux in diffuse components does not appear to vary with flux density, although the percentage of sources that have complex structure increases with flux density. The observations are consistent with a transition in the nature of extended radio sources from FR-II radio source morphology, which dominates the mJy population, to FR-I structure at sub-mJy flux density. (Abridged)Comment: 18 pages, 8 figues, 6 tables, accepted for publication in MNRA

    Neural network-based colonoscopic diagnosis using on-line learning and differential evolution

    Get PDF
    In this paper, on-line training of neural networks is investigated in the context of computer-assisted colonoscopic diagnosis. A memory-based adaptation of the learning rate for the on-line back-propagation (BP) is proposed and used to seed an on-line evolution process that applies a differential evolution (DE) strategy to (re-) adapt the neural network to modified environmental conditions. Our approach looks at on-line training from the perspective of tracking the changing location of an approximate solution of a pattern-based, and thus, dynamically changing, error function. The proposed hybrid strategy is compared with other standard training methods that have traditionally been used for training neural networks off-line. Results in interpreting colonoscopy images and frames of video sequences are promising and suggest that networks trained with this strategy detect malignant regions of interest with accuracy

    Understanding rural areas dynamics from a complex perspective. An application of Prospective Structural Analysis

    Get PDF
    The development of rural areas continues to be an international priority. The urgent need to fight poverty (mainly concentrated in rural areas) in developing countries, and the demand for increasing economic and social cohesion in developed countries, explain this priority on the political agendas of multilateral bodies, the EU and most other countries. When Development Economics was acknowledged as part of the social and economic theory in the 50’s, different theories and models have tried to explain the unevenness of development and the key elements or conditions that foster it. Traditional rural development programmes were characterised by the implementation of non coordinated, sectoral, horizontal and top-down policies and strategies. The lack of effectiveness and the failures prompted by these policies have propelled the development of new approaches. Territorial rural development is a policy approach embracing contributions from different theoretical frameworks that attempt to foster development strategies based on the consideration of territory as a social construction. Thus, the territory (including all the existing elements and its interactions) has become a key actor for development. However, most of these approaches contemplate rural world through simplistic and monodimensional analysis based on methodologies from single disciplines and on quantitative and/or qualitative morphological descriptions. The pretended multidisciplinarity, frequently ends up on an addition of mono-disciplinary analysis around the object of study. The objective of the present paper is to check the role different elements considered relevant for development by literature®s recent approaches play or can play in rural territories with a very different development situation, using techniques and tools that allow the analysis of rural areas from a complex perspective.territorial rural development, complexity, prospective structural analysis, Community/Rural/Urban Development,

    The impact of brand communication on brand equity through Facebook

    Get PDF
    Purpose: The purpose of this study is to fill the gap in the discussion of the ways in which firm-created and user-generated social media brand communication impacts consumer-based brand equity metrics through Facebook. Design/methodology/approach: We evaluated 302 data sets that were generated through a standardized online-survey to investigate the impact of firm-created and user-generated social media brand communication on brand awareness/associations, perceived quality, and brand loyalty across 60 brands within three different industries: non-alcoholic beverages, clothing, and mobile network providers. We applied structural equation modeling techniques (SEM) to investigate the effects of social media brand communication on consumers’ perception of brand equity metrics, as well as in an examination of industry-specific differences. Findings: The results of our empirical studies showed that both firm-created and user-generated social media brand communication influence brand awareness/associations; whereas, user-generated social media brand communication had a positive impact on brand loyalty and perceived brand quality. Additionally, there are significant differences between the industries being investigated. Originality/value: This article is pioneering in that it exposes the effects of two different types of social media brand communication (i.e., firm-created and user-generated social media communication) on consumer-based brand equity metrics, a topic of relevance for both marketers and scholars in the era of social media. Additionally, it differentiates the effects of social media brand communication across industries, which indicate that practitioners should implement social media strategies according to industry specifics to lever consumer-based brand equity metrics
    • 

    corecore