Domain is a Moving Target for Relational Learning

The domain for relational learning was manipulated by varying the training set size for pigeons that had learned the same/different (S/D) concept. Six pigeons that had learned a S/D task with pairs of pictures with a set size of 1,024 picture items had their training set size reduced to 8 items. Training on the reduced 8-item set was followed by transfer testing that was repeated four times. Transfer performance following reduction of the training set to 8 items was less than it had been when the pigeons were trained with the 1,024-item set, but 25.8% above chance. This partial abstract-concept learning remained constant over the four tests with novel stimuli. The results show that a broad domain established by a large expanding training set can once again become restricted by further training with a small training set

Development and validation of a Spanish translation of the Yale activity questionnaire

Background: Valid measures of physical activity are critical research tools. The objective of this study was to develop a Spanish translation of the Yale Physical Activity Survey, and to provide preliminary evidence of its validity in a population of Dominican patients with lower extremity arthritis. Methods: A Dominican bilingual health care professional translated the Yale Physical Activity Survey (YPAS) from English to Spanish. Several Dominican adults reviewed the translation to ensure it was linguistically and culturally appropriate. The questionnaire was back-translated to English by a North American researcher who is fluent in Spanish. Discrepancies between the original and back-translated versions were resolved by the translator and back-translator. The Spanish translation was administered to 108 Dominican subjects with advanced hip or knee arthritis prior to (N = 44) or one to four years following (N = 64) total joint replacement. We assessed construct validity by examining the association of YPAS scores and measures of functional status and pain (WOMAC), quality of life (EQ-5D) and the number of painful lower extremity joints. Results: A higher YPAS Part II Activity Dimensions Summary Index score had weak to modest correlations with worse function and quality of life as measured with the WOMAC function scale (r = 0.21, p = 0.03), SF-36 Physical Activity Scale (r = 0.29, p = 0.004) and EQ-5D (r = 0.34, p = 0.0007). Total minutes of vigorous activity and walking had weak to modest correlation with these measures (WOMAC Function Scale (r = 0.15, p = 0.15), SF-36 Physical Activity Scale (r = 0.21, p = 0.04) and EQ-5D utility (r = 0.24, p = 0.02)). Correlations between the YPAS Part I energy expenditure score and these measures were lower (WOMAC Function Scale (r = 0.07, p = 0.49), SF-36 Physical Activity Scale (r = 0.03, p = 0.74) and EQ-5D utility (r = 0.18, p = 0.07)). Conclusions: We have developed a new Spanish translation of the Yale Physical Activity Survey and provided evidence of convergent validity in a sample of Dominican patients prior to or 1–4 years following total joint replacement

Normalized ghost imaging

We present an experimental comparison between different iterative ghost imaging algorithms. Our experimental setup utilizes a spatial light modulator for generating known random light fields to illuminate a partially-transmissive object. We adapt the weighting factor used in the traditional ghost imaging algorithm to account for changes in the efficiency of the generated light field. We show that our normalized weighting algorithm can match the performance of differential ghost imaging

Empirical evaluation of the inter-relationship of articular elements involved in the pathoanatomy of knee osteoarthritis using Magnetic Resonance Imaging

<p>Abstract</p> <p>Background</p> <p>In this cross-sectional study, we conducted a comprehensive assessment of all articular elements that could be measured using knee MRI. We assessed the association of pathological change in multiple articular structures involved in the pathoanatomy of osteoarthritis.</p> <p>Methods</p> <p>Knee MRI scans from patients over 45 years old were assessed using a semi-quantitative knee MRI assessment form. The form included six distinct elements: cartilage, bone marrow lesions, osteophytes, subchondral sclerosis, joint effusion and synovitis. Each type of pathology was graded using an ordinal scale with a value of zero indicating no pathology and higher values indicating increasingly severe levels of pathology. The principal dependent variable for comparison was the mean cartilage disease score (CDS), which captured the aggregate extent of involvement of articular cartilage. The distribution of CDS was compared to the individual and cumulative distributions of each articular element using the Chi-squared test. The correlations between pathological change in the various articular structures were assessed in a Spearman correlation table.</p> <p>Results</p> <p>Data from 140 patients were available for review. The cohort had a median age of 61 years (range 45-89) and was 61% female. The cohort included a wide spectrum of OA severity. Our analysis showed a statistically significant trend towards pathological change involving more articular elements as CDS worsened (p-value for trend < 0.0001). Comparison of CDS to change in the severity of pathology of individual articular elements showed statistically significant trends towards more severe pathology as CDS worsened for osteophytes (p-value for trend < 0.0001), bone marrow lesions (p = 0.0003), and subchondral sclerosis (p = 0.009), but not joint effusion or synovitis. There was a moderate correlation between cartilage damage, osteophytes and BMLs as well as a moderate correlation between joint effusion and synovitis. However, cartilage damage and osteophytes were only weakly associated with synovitis or joint effusion.</p> <p>Conclusion</p> <p>Our results support an inter-relationship of multiple articular elements in the pathoanatomy of knee OA. Prospective studies of OA pathogenesis in humans are needed to correlate these findings to clinically relevant outcomes such as pain and function.</p

North American Football Fans Show Neurofunctional Differences in Response to Violence: Implications for Public Health and Policy

While social and behavioral effects of violence in the media have been studied extensively, much less is known about how sports affect perceptions of violence. The current study examined neurofunctional differences between fans and non-fans of North American football (a contact sport) while viewing violent imagery. Participants viewed images of violence in both football and non-football settings while high-resolution functional magnetic resonance imaging (fMRI) data were acquired from their brains. Neurological activation was compared between these violence types and between groups. Fans of football show diminished activation in brain regions involved in pain perception and empathy such as the anterior cingulate cortex, fusiform gyrus, insula, and temporal pole when viewing violence in the context of football compared to more broadly violent images. Non-fans of football showed no such effect for the types of violent imagery and had higher activation levels than fans of football for the specified brain regions. These differences show that fans of football may perceive violence differently when it is in the context of football. These fan attitudes have potential policy implications for addressing the issue of concussions in North American football