124,238 research outputs found

    Does Physical Activity Influence Semantic Memory Activation in Amnestic Mild Cognitive Impairment?

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    The effect of physical activity (PA) on functional brain activation for semantic memory in amnestic mild cognitive impairment (aMCI) was examined using event-related functional magnetic resonance imaging during fame discrimination. Significantly greater semantic memory activation occurred in the left caudate of High- versus Low-PA patients, (P=0.03), suggesting PA may enhance memory-related caudate activation in aMCI

    Assessing the quality of a student-generated question repository

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    We present results from a study that categorizes and assesses the quality of questions and explanations authored by students, in question repositories produced as part of the summative assessment in introductory physics courses over the past two years. Mapping question quality onto the levels in the cognitive domain of Bloom's taxonomy, we find that students produce questions of high quality. More than three-quarters of questions fall into categories beyond simple recall, in contrast to similar studies of student-authored content in different subject domains. Similarly, the quality of student-authored explanations for questions was also high, with approximately 60% of all explanations classified as being of high or outstanding quality. Overall, 75% of questions met combined quality criteria, which we hypothesize is due in part to the in-class scaffolding activities that we provided for students ahead of requiring them to author questions.Comment: 24 pages, 5 figure

    Development and Validation of a Rule-based Time Series Complexity Scoring Technique to Support Design of Adaptive Forecasting DSS

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    Evidence from forecasting research gives reason to believe that understanding time series complexity can enable design of adaptive forecasting decision support systems (FDSSs) to positively support forecasting behaviors and accuracy of outcomes. Yet, such FDSS design capabilities have not been formally explored because there exists no systematic approach to identifying series complexity. This study describes the development and validation of a rule-based complexity scoring technique (CST) that generates a complexity score for time series using 12 rules that rely on 14 features of series. The rule-based schema was developed on 74 series and validated on 52 holdback series using well-accepted forecasting methods as benchmarks. A supporting experimental validation was conducted with 14 participants who generated 336 structured judgmental forecasts for sets of series classified as simple or complex by the CST. Benchmark comparisons validated the CST by confirming, as hypothesized, that forecasting accuracy was lower for series scored by the technique as complex when compared to the accuracy of those scored as simple. The study concludes with a comprehensive framework for design of FDSS that can integrate the CST to adaptively support forecasters under varied conditions of series complexity. The framework is founded on the concepts of restrictiveness and guidance and offers specific recommendations on how these elements can be built in FDSS to support complexity

    Motor Timing Intraindividual Variability in Amnestic Mild Cognitive Impairment and Cognitively Intact Elders at Genetic Risk for Alzheimer’s Disease

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    Introduction: Intraindividual variability (IIV) in motor performance has been shown to predict future cognitive decline. The apolipoprotein E-epsilon 4 (APOE-ε4) allele is also a well-established risk factor for memory decline. Here, we present novel findings examining the influence of the APOE-ε4 allele on the performance of asymptomatic healthy elders in comparison to individuals with amnestic MCI (aMCI) on a fine motor synchronization, paced finger-tapping task (PFTT). Method: Two Alzheimer’s disease (AD) risk groups, individuals with aMCI (n = 24) and cognitively intact APOE-ε4 carriers (n = 41), and a control group consisting of cognitively intact APOE-ε4 noncarriers (n = 65) completed the Rey Auditory Verbal Learning Test and the PFTT, which requires index finger tapping in synchrony with a visual stimulus (interstimulus interval = 333 ms). Results: Motor timing IIV, as reflected by the standard deviation of the intertap interval (ITI), was greater in the aMCI group than in the two groups of cognitively intact elders; in contrast, all three groups had statistically equivalent mean ITI. No significant IIV differences were observed between the asymptomatic APOE-ε4 carriers and noncarriers. Poorer episodic memory performance was associated with greater IIV, particularly in the aMCI group. Conclusions: Results suggest that increased IIV on a fine motor synchronization task is apparent in aMCI. This IIV measure was not sensitive in discriminating older asymptomatic individuals at genetic risk for AD from those without such a genetic risk. In contrast, episodic memory performance, a well-established predictor of cognitive decline in preclinical AD, was able to distinguish between the two cognitively intact groups based on genetic risk

    Interactive Effects of Physical Activity and APOE-ε4 On White Matter Tract Diffusivity in Healthy Elders

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    Older adult apolipoprotein-E epsilon 4 (APOE-ε4) allele carriers vary considerably in the expression of clinical symptoms of Alzheimer\u27s disease (AD), suggesting that lifestyle or other factors may offer protection from AD-related neurodegeneration. We recently reported that physically active APOE-ε4 allele carriers exhibit a stable cognitive trajectory and protection from hippocampal atrophy over 18 months compared to sedentary ε4 allele carriers. The aim of this study was to examine the interactions between genetic risk for AD and physical activity (PA) on white matter (WM) tract integrity, using diffusion tensor imaging (DTI) MRI, in this cohort of healthy older adults (ages of 65 to 89). Four groups were compared based on the presence or absence of an APOE-ε4 allele (High Risk; Low Risk) and self-reported frequency and intensity of leisure time physical activity (PA) (High PA; Low PA). As predicted, greater levels of PA were associated with greater fractional anisotropy (FA) and lower radial diffusivity in healthy older adults who did not possess the APOE-ε4 allele. However, the effects of PA were reversed in older adults who were at increased genetic risk for AD, resulting in significant interactions between PA and genetic risk in several WM tracts. In the High Risk-Low PA participants, who had exhibited episodic memory decline over the previous 18-months, radial diffusivity was lower and fractional anisotropy was higher, compared to the High Risk-High PA participants. In WM tracts that subserve learning and memory processes, radial diffusivity (DR) was negatively correlated with episodic memory performance in physically inactive APOE-ε4 carriers, whereas DR was positively correlated with episodic memory performance in physically active APOE-ε4 carriers and the two Low Risk groups. The common model of demyelination-induced increase in radial diffusivity cannot directly explain these results. Rather, we hypothesize that PA may protect APOE-ε4 allele carriers from selective neurodegeneration of individual fiber populations at locations of crossing fibers within projection and association WM fiber tracts

    Sexual Minority Stress and Suicide Risk: Identifying Resilience through Personality Profile Analysis

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    Sexual minority-based victimization, which includes threats or enacted interpersonal violence, predicts elevated suicide risk among sexual minority individuals. However, research on personality factors that contribute to resilience among sexual minority populations is lacking. Using the Five-Factor Model, we hypothesized that individuals classified as adaptive (vs. at-risk) would be at decreased risk for a suicide attempt in the context of reported lifetime victimization. Sexual minority-identified young adults between the ages of 18 and 25 years (N = 412) were recruited nationally and asked to complete an online survey containing measures of personality, sexual minority stress, and lifetime suicide attempts. A 2-stage cluster analytic method was used to empirically derive latent personality profiles and to classify respondents as adaptive (lower neuroticism and higher extroversion, agreeableness, conscientiousness, and openness) or at-risk (higher neuroticism, lower extroversion, agreeableness, conscientiousness, and openness) on the basis of their Five-Factor Personality trait scores. Adaptive individuals were slightly older and less likely to conceal their sexual orientation, but they reported similar rates of victimization, discrimination, and internalized heterosexism as their at-risk counterparts. Logistic regression results indicate that despite reporting similar rates of victimization, which was a significant predictor of lifetime suicide attempt, adaptive individuals evidenced decreased risk for attempted suicide in the context of victimization relative to at-risk individuals. These findings suggest that an adaptive personality profile may confer resilience in the face of sexual minority-based victimization. This study adds to our knowledge of sexual minority mental health and highlights new directions for future research

    Special Education Needs across the pre-school period

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    The Early Years Transitions and Special Educational Needs (EYTSEN) project builds on the work of the Effective Provision of Pre-School Education (EPPE) project, a major longitudinal study of a national sample of young children’s progress and development through pre-school and into primary school until the end of Key Stage 1 (age 3+ to 7 years) (Sylva et al., 1999).1 Both the EPPE and EYTSEN research studies are funded by the DfES. The EYTSEN study explores evidence of possible special educational needs (SEN) amongst pre-school children. It uses a range of information to identify children who may be ‘at risk’ in terms of either cognitive or social behavioural development and investigates links with a variety of child, parent and family characteristics. It also describes variations in the policies and provision offered by different pre-school centres designed to support children with special needs. Information for over 2800 children attending 141 pre-school centres selected from five regions across England has been analysed. Centres have been drawn from a range of types of providers (local authority day nursery, combined centres, playgroups, private day nurseries, nursery schools and nursery classes). The research was designed to study the six main types of institutional provision, not other forms of pre-school care such as relatives, childminders or nannies. One-to-one assessments of different aspects of young children’s cognitive development were conducted by trained researchers at entry to the study (age 3+) and later at entry to primary school. In addition, ratings of individual children’s social and behavioural development have been collected from pre-school workers at entry to pre-school, and from teachers when children enter primary school. We thus have several sources of information that can be used to explore young children’s cognitive attainment and progress and their social behavioural development. In addition to child assessments, parental interviews conducted when children entered the study have been used to collect detailed information about childcare history and health, and characteristics of children, their families and home environments. Interviews with centre managers of the pre-school settings attended by children have been used to provide details about pre-school settings including provision for SEN. Observations concerning aspects of centre ‘quality’, and measures of the environment experienced by children were made by trained researchers. The distribution of children in the sample identified as \u27at risk\u27 of SEN between different types of pre-school settings has been examined. In addition, the extent of variation in provision made for SEN between different centres and type of pre-school setting has been investigated. The EYTSEN study analysed these different sources of information and the linkages amongst them with a view to informing policy and practice related to the characteristics of young children ‘at risk’ of SEN and pre-school centre practices associated with changes in risk status

    Pain Response after Maximal Aerobic Exercise in Adolescents across Weight Status

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    Introduction Pain reports are greater with increasing weight status, and exercise can reduce pain perception. It is unknown, however, whether exercise can relieve pain in adolescents of varying weight status. The purpose of this study was to determine whether adolescents across weight status report pain relief after high-intensity aerobic exercise (exercise-induced hypoalgesia (EIH)). Methods Sixty-two adolescents (15.1 ± 1.8 yr, 29 males) participated in the following three sessions: 1) pressure pain thresholds (PPT) before and after quiet rest, clinical pain (McGill Pain Questionnaire), and physical activity levels (self-report and ActiSleep Plus Monitors) were measured, 2) PPT were measured with a computerized algometer at the fourth finger’s nailbed, middle deltoid muscle, and quadriceps muscle before and after maximal oxygen uptake test (V˙O2max Bruce Treadmill Protocol), and 3) body composition was measured with dual-energy x-ray absorptiometry. Results All adolescents met criteria for V˙O2max. On the basis of body mass index z-score, adolescents were categorized as having normal weight (n = 33) or being overweight/obese (n = 29). PPT increased after exercise (EIH) and were unchanged with quiet rest (trial × session, P = 0.02). EIH was similar across the three sites and between normal-weight and overweight/obese adolescents. Physical activity and clinical pain were not correlated with EIH. Overweight/obese adolescents had similar absolute V˙O2max (L·min−1) but lower relative V˙O2max (mL·kg−1·min−1) compared with normal-weight adolescents. When adolescents were categorized using FitnessGram standards as unfit (n = 15) and fit (n = 46), the EIH response was similar between fitness levels. Conclusions This study is the first to establish that both overweight and normal-weight adolescents experience EIH. EIH after high-intensity aerobic exercise was robust in adolescents regardless of weight status and not influenced by physical fitness

    An Empirical Examination of Symptom Substitution Associated with Behavior Therapy for Tourette\u27s Disorder

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    Over the past six decades, behavior therapy has been a major contributor to the development of evidence-based psychotherapy treatments. However, a long-standing concern with behavior therapy among many nonbehavioral clinicians has been the potential risk for symptom substitution. Few studies have been conducted to evaluate symptom substitution in response to behavioral treatments, largely due to measurement and definitional challenges associated with treated psychiatric symptoms. Given the overt motor and vocal tics associated with Tourette’s disorder, it presents an excellent opportunity to empirically evaluate the potential risk for symptom substitution associated with behavior therapy. The present study examined the possible presence of symptom substitution using four methods: (a) the onset of new tic symptoms, (b) the occurrence of adverse events, (c) change in tic medications, and (d) worsening of co-occurring psychiatric symptoms. Two hundred twenty-eight participants with Tourette’s disorder or persistent motor or vocal tic disorders were randomly assigned to receive behavioral therapy or supportive therapy for tics. Both therapies consisted of eight sessions over 10 weeks. Results indicated that participants treated with behavior therapy were not more likely to have an onset of new tic symptoms, experience adverse events, increase tic medications, or have an exacerbation in co-occurring psychiatric symptoms relative to participants treated with supportive therapy. Further analysis suggested that the emergence of new tics was attributed with the normal waxing and waning nature of Tourette’s disorder. Findings provide empirical support to counter the long-standing concern of symptom substitution in response to behavior therapy for individuals with Tourette\u27s disorder

    Testing the Unfolding Theory of Turnover: Development of an Exit Survey

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    Understanding turnover has always been a concern for organizations. The costs of turnover to an organization are both direct and indirect, through financial and personnel consequences. By understanding why employees leave, organizations can create more effective retention strategies in hopes of keeping top talent. One theory of turnover, The Unfolding Theory, proposes that employees follow one of five cognitive pathways when deciding to leave an organization. Previous studies evaluating this theory have both methodological and administrative flaws, such as conducting interviews after employees leave the organization. The present study examined the Unfolding Theory by creating an exit survey based on all the aspects of the theory and administering the survey to 107 employees before leaving an organization. The results indicated that the Unfolding Theory does well to capture the processes employees engage in when deciding to leave an organization. However, the data also suggested that additional cognitive pathways may exist and that different groups of employees may have a higher prevalence for a particular pathway. The study discusses how organizations can utilize the findings to gather exit data more accurately, which will help to better understand why employees leave an organization
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