560 research outputs found

    Perceptual learning reduces crowding in amblyopia and in the normal periphery

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    Amblyopia is a developmental visual disorder of cortical origin, characterized by crowding and poor acuity in central vision of the affected eye. Crowding refers to the adverse effects of surrounding items on object identification, common only in normal peripheral but not central vision. We trained a group of adult human amblyopes on a crowded letter identification task to assess whether the crowding problem can be ameliorated. Letter size was fixed well above the acuity limit, and letter spacing was varied to obtain spacing thresholds for central target identification. Normally sighted observers practiced the same task in their lower peripheral visual field. Independent measures of acuity were taken in flanked and unflanked conditions before and after training to measure crowding ratios at three fixed letter separations. Practice improved the letter spacing thresholds of both groups on the training task, and crowding ratios were reduced after posttest. The reductions in crowding in amblyopes were associated with improvements in standard measures of visual acuity. Thus, perceptual learning reduced the deleterious effects of crowding in amblyopia and in the normal periphery. The results support the effectiveness of plasticity-based approaches for improving vision in adult amblyopes and suggest experience-dependent effects on the cortical substrates of crowding

    The effect of normal aging and age-related macular degeneration on perceptual learning

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    We investigated whether perceptual learning could be used to improve peripheral word identification speed. The relationship between the magnitude of learning and age was established in normal participants to determine whether perceptual learning effects are age invariant. We then investigated whether training could lead to improvements in patients with age-related macular degeneration (AMD). Twenty-eight participants with normal vision and five participants with AMD trained on a word identification task. They were required to identify three-letter words, presented 10° from fixation. To standardize crowding across each of the letters that made up the word, words were flanked laterally by randomly chosen letters. Word identification performance was measured psychophysically using a staircase procedure. Significant improvements in peripheral word identification speed were demonstrated following training (71% ± 18%). Initial task performance was correlated with age, with older participants having poorer performance. However, older adults learned more rapidly such that, following training, they reached the same level of performance as their younger counterparts. As a function of number of trials completed, patients with AMD learned at an equivalent rate as age-matched participants with normal vision. Improvements in word identification speed were maintained at least 6 months after training. We have demonstrated that temporal aspects of word recognition can be improved in peripheral vision with training across a range of ages and these learned improvements are relatively enduring. However, training targeted at other bottlenecks to peripheral reading ability, such as visual crowding, may need to be incorporated to optimize this approach

    Integrity and Ethics in Western Adjudicatory Systems : Toward a Standard

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    As a global community comes closer to a reality in which there is an international rule of law, a borderless standard of ethics and integrity in adjudication must be developed. Since the beginning of structured adjudication of disputes, ethics and integrity have been an integral part of the process. Even in biblical law, ethics and integrity are emphasized. Now, that many legal disputes, especially in the commercial arena including business and trade disputes, are being adjudicated between and among many different states and individuals from many different states, with many different formal and informal adjudicatory systems, the need for ethics and integrity in those systems is essential for the world community to have confidence in the adjudicatory outcome. Those engaged in multi-national business and trade want to be sure that disputes will be fairly and impartially judged. This document will discuss the essential elements in designing and evaluating an adjudication system that will promote ethical conduct and integrity in both the system and in the individuals that adjudicate, administer and use the system. If we go forward without an agreement on what is necessary to assure ethical conduct, world citizens can not be assured that their rights will be protected. Corruption and decay clearly undermine the confidence of the world community when a system of adjudication cannot assure its participants that judgments reached are free of such negative elements. Ethics and integrity are fundamental to the concept of fair judgment. Ultimately, faith and trust in adjudication promotes world peace and free commerce

    Integrity and Ethics in Western Adjudicatory Systems : Toward a Standard

    Get PDF
    As a global community comes closer to a reality in which there is an international rule of law, a borderless standard of ethics and integrity in adjudication must be developed. Since the beginning of structured adjudication of disputes, ethics and integrity have been an integral part of the process. Even in biblical law, ethics and integrity are emphasized. Now, that many legal disputes, especially in the commercial arena including business and trade disputes, are being adjudicated between and among many different states and individuals from many different states, with many different formal and informal adjudicatory systems, the need for ethics and integrity in those systems is essential for the world community to have confidence in the adjudicatory outcome. Those engaged in multi-national business and trade want to be sure that disputes will be fairly and impartially judged. This document will discuss the essential elements in designing and evaluating an adjudication system that will promote ethical conduct and integrity in both the system and in the individuals that adjudicate, administer and use the system. If we go forward without an agreement on what is necessary to assure ethical conduct, world citizens can not be assured that their rights will be protected. Corruption and decay clearly undermine the confidence of the world community when a system of adjudication cannot assure its participants that judgments reached are free of such negative elements. Ethics and integrity are fundamental to the concept of fair judgment. Ultimately, faith and trust in adjudication promotes world peace and free commerce

    Genetic determinants of co-accessible chromatin regions in activated T cells across humans.

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    Over 90% of genetic variants associated with complex human traits map to non-coding regions, but little is understood about how they modulate gene regulation in health and disease. One possible mechanism is that genetic variants affect the activity of one or more cis-regulatory elements leading to gene expression variation in specific cell types. To identify such cases, we analyzed ATAC-seq and RNA-seq profiles from stimulated primary CD4+ T cells in up to 105 healthy donors. We found that regions of accessible chromatin (ATAC-peaks) are co-accessible at kilobase and megabase resolution, consistent with the three-dimensional chromatin organization measured by in situ Hi-C in T cells. Fifteen percent of genetic variants located within ATAC-peaks affected the accessibility of the corresponding peak (local-ATAC-QTLs). Local-ATAC-QTLs have the largest effects on co-accessible peaks, are associated with gene expression and are enriched for autoimmune disease variants. Our results provide insights into how natural genetic variants modulate cis-regulatory elements, in isolation or in concert, to influence gene expression

    Fifteen new risk loci for coronary artery disease highlight arterial-wall-specific mechanisms

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    Coronary artery disease (CAD) is a leading cause of morbidity and mortality worldwide. Although 58 genomic regions have been associated with CAD thus far, most of the heritability is unexplained, indicating that additional susceptibility loci await identification. An efficient discovery strategy may be larger-scale evaluation of promising associations suggested by genome-wide association studies (GWAS). Hence, we genotyped 56,309 participants using a targeted gene array derived from earlier GWAS results and performed meta-analysis of results with 194,427 participants previously genotyped, totaling 88,192 CAD cases and 162,544 controls. We identified 25 new SNP-CAD associations (P < 5 × 10(-8), in fixed-effects meta-analysis) from 15 genomic regions, including SNPs in or near genes involved in cellular adhesion, leukocyte migration and atherosclerosis (PECAM1, rs1867624), coagulation and inflammation (PROCR, rs867186 (p.Ser219Gly)) and vascular smooth muscle cell differentiation (LMOD1, rs2820315). Correlation of these regions with cell-type-specific gene expression and plasma protein levels sheds light on potential disease mechanisms

    Mapping the role of sexuality in adolescent mental health and substance use

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    Individuals who belong to a sexual minority are at greater risk of adverse health and social outcomes. These effects are observed during adolescence when many mental health problems, such as depression, first emerge. Here, we used a network analytic approach to better understand the role that sexual minority status plays in the association between depression, interpersonal difficulties and substance use in a large sample of mid-adolescents. In doing so, we used data from 8017 fourteen year olds from the UK’s Millennium Cohort Study, of which 490 self-identified as belonging to a sexual minority. We found that sexual minority status was highly central in the network and connected to multiple adverse outcomes, sometimes directly and sometimes indirectly. The largest single association was between sexual minority status and depression, and this link mediated multiple negative associations with being in a sexual minority. The shortest path to drinking, poor social support and closeness with parents and victimization occurred via depression. The shortest path to smoking and drug use occurred via conduct problems. We also identified three distinct profiles of adverse outcomes among those belonging to a sexual minority, highlighting the heterogeneous nature of this group

    Functional and molecular characterization of hyposensitive underactive bladder tissue and urine in streptozotocin-induced diabetic rat

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    Background: The functional and molecular alterations of nerve growth factor (NGF) and Prostaglandin E2 (PGE2) and its receptors were studied in bladder and urine in streptozotocin (STZ)-induced diabetic rats. Methodology/Principal Findings: Diabetes mellitus was induced with a single dose of 45 mg/kg STZ Intraperitoneally (i.p) in female Sprague-Dawley rats. Continuous cystometrogram were performed on control rats and STZ treated rats at week 4 or 12 under urethane anesthesia. Bladder was then harvested for histology, expression of EP receptors and NGF by western blotting, PGE2 levels by ELISA, and detection of apoptosis by TUNEL staining. In addition, 4-hr urine was collected from all groups for urine levels of PGE2, and NGF assay. DM induced progressive increase of bladder weight, urine production, intercontraction interval (ICI) and residual urine in a time dependent fashion. Upregulation of Prostaglandin E receptor (EP)1 and EP3 receptors and downregulation of NGF expression, increase in urine NGF and decrease levels of urine PGE2 at week 12 was observed. The decrease in ICI by intravesical instillation of PGE2 was by 51% in control rats and 31.4% in DM group at week 12. Conclusions/Significance: DM induced hyposensitive underactive bladder which is characterized by increased inflammatory reaction, apoptosis, urine NGF levels, upregulation of EP1 and EP3 receptors and decreased bladder NGF and urine PGE2. The data suggest that EP3 receptor are potential targets in the treatment of diabetes induced underactive bladder. © 2014 Nirmal et al
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