750 research outputs found

    Does higher sampling rate (multiband + SENSE) improve group statistics - An example from social neuroscience block design at 3T

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    Multiband (MB) or Simultaneous multi-slice (SMS) acquisition schemes allow the acquisition of MRI signals from more than one spatial coordinate at a time. Commercial availability has brought this technique within the reach of many neuroscientists and psychologists. Most early evaluation of the performance of MB acquisition employed resting state fMRI or the most basic tasks. In this study, we tested whether the advantages of using MB acquisition schemes generalize to group analyses using a cognitive task more representative of typical cognitive neuroscience applications. Twenty-three subjects were scanned on a Philips 3 ​T scanner using five sequences, up to eight-fold acceleration with MB-factors 1 to 4, SENSE factors up to 2 and corresponding TRs of 2.45s down to 0.63s, while they viewed (i) movie blocks showing complex actions with hand object interactions and (ii) control movie blocks without hand object interaction. Data were processed using a widely used analysis pipeline implemented in SPM12 including the unified segmentation and canonical HRF modelling. Using random effects group-level, voxel-wise analysis we found that all sequences were able to detect the basic action observation network known to be recruited by our task. The highest t-values were found for sequences with MB4 acceleration. For the MB1 sequence, a 50% bigger voxel volume was needed to reach comparable t-statistics. The group-level t-values for resting state networks (RSNs) were also highest for MB4 sequences. Here the MB1 sequence with larger voxel size did not perform comparable to the MB4 sequence. Altogether, we can thus recommend the use of MB4 (and SENSE 1.5 or 2) on a Philips scanner when aiming to perform group-level analyses using cognitive block design fMRI tasks and voxel sizes in the range of cortical thickness (e.g. 2.7 ​mm isotropic). While results will not be dramatically changed by the use of multiband, our results suggest that MB will bring a moderate but significant benefit

    Neuropsychiatric symptoms of cholinergic deficiency occur with degradation of the projections from the nucleus basalis of Meynert

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    This study aims to evaluate the relation between a cluster of neuropsychiatric symptoms related to cholinergic deficiency and degradation of the cortical cholinergic projections which project from the nucleus basalis of Meynert to the cerebral cortex. An atlas of the pathway from the nucleus basalis to the cortex (NbM cortical pathway) was constructed using diffusion tensor imaging and tractography in 87 memory clinic patients. Structural degradation was considered to be represented by lower fractional anisotropy (FA) and higher mean diffusivity (MD). Neuropsychiatric symptoms were assessed using the Neuropsychiatric Inventory. A predefined cluster including agitation, anxiety, apathy, delusions, hallucinations, and irritability was labeled as the cholinergic deficiency syndrome (CDS). In regression analyses, lower FA and higher MD in the NbM cortical pathway were associated with CDS symptoms but not with other neuropsychiatric symptoms. These associations were independent of cerebral atrophy and overall FA or MD. There was no association between interruption of the NbM cortical pathway by white matter hyperintensities and CDS symptoms. Cox regression suggested a trend for higher mortality with lower FA in the NbM cortical pathway may exist. These findings provide anatomical support for the hypothesis that degradation of the cholinergic projections from the nucleus basalis of Meynert may lead to a distinct clinical syndrome. Future studies could use our results to test the utility of assessing NbM projection integrity to identify patients who may benefit from cholinergic treatment or with a worse prognosi

    Interplays of psychometric abilities on learning gross anatomy

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    In recent years, there has been international debate concerning how students learn anatomy. The rapid increase in scientific knowledge has put pressure on the place of anatomy within the medical and allied health professional curricula, as well as the design and structure of anatomy courses. In this regard, relatively little is known about what medical and allied health professions students want from an anatomy course or how they learn it. To assess students’ learning approaches and perceptions of anatomy, a series of psychometric tests were administered to Medical (n=82), Podiatry (n=21), and Pharmacy (n=74) students in the United Kingdom. Analysis of the Anatomy Learning Experience (ALE) questionnaire revealed a predominantly positive attitude towards anatomy and the dissection room, with most valuing cadaveric dissection and not regarding it as a daunting environment. Further to this, analysis of the Approaches to Studying Inventory for Students (ASSIST) revealed predominant preferences for strategic and deep approaches. Personality traits were associated with certain learning approaches; neuroticism with surface (p=0.038), conscientiousness with both a deep and strategic approach (p=0.000 and p=0.060 respectively). Certain personality traits were also found to be associated with anatomy experience e.g. neuroticism and achievement striving felt the most effective way to learn was to get their hands in and feel for structures (p=0.044 and p=0.012 respectively). This study concludes that undergraduate students of medicine, podiatry and pharmacy learn anatomy in slightly different ways. Preparation for classroom activities should centre on the promotion of an optimum learning environment and teaching strategies which promote a deep approach to learning. Understanding students’ personality and learning experiences should help teachers improve the students’ learning of anatomy for effective application to clinical practice

    Song Tutorial: In The Springtime, arr. Betty Jackson King

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    This song tutorial is designed to guide the learning and practice for the vocal solo In The Springtime, arr. Betty Jackson King. This tutorial does not replace individual practice time, rather it is a tool to enhance that time and provide resources for singers. (Score not included)

    Study on Solar KANG Heating System for Cold Areas

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    AbstractThe current rural traditional heated kang cannot meet people's increasing requirements of comfort and environmental protection. This paper propose solar kang heating system in cold regions. System performance and heating effect were analyzed. We selected two typical rooms. One was set in traditional kang, and the other one was solar Kang type. Using temperature recording instrument and 64 roads inspection instrument and other instruments, we test the indoor temperature and the kang surface temperature of two rooms. Solar kang thermal resistance, heat storage, heat dissipation and heating effect were analyzed and compared. The results of the study show this system have the smaller fluctuation, more comfort while alleviating the kang surface overheat or super-cooling problem. It satisfied the requirements of indoor thermal comfort. The warming rate is 5.17°C/h, and the cooling rate is 3.01°C/h. These are slower than traditional Huokang speed. It improved the heat storage capacity of kang body with surface heat dissipation 1237W. Average temperature of the solar kang heating room was improved 3.28°C. It gets the smaller indoor temperature fluctuation. PMV values are concentrated about -0.5, and this basically meet the requirements of the user comfort

    Increased brain-predicted aging in treated HIV disease

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    Objective: To establish whether HIV disease is associated with abnormal levels of age-related brain atrophy, by estimating apparent brain age using neuroimaging and exploring whether these estimates related to HIV status, age, cognitive performance, and HIV-related clinical parameters. Methods: A large sample of virologically suppressed HIV-positive adults (n = 162, age 45-82 years) and highly comparable HIV-negative controls (n = 105) were recruited as part of the Comorbidity in Relation to AIDS (COBRA) collaboration. Using T1-weighted MRI scans, a machinelearning model of healthy brain aging was defined in an independent cohort (n = 2,001, aged 1890 years). Neuroimaging data from HIV-positive and HIV-negative individuals were then used to estimate brain-predicted age; then brain-predicted age difference (brain-PAD 5 brain-predicted brain age 2 chronological age) scores were calculated. Neuropsychological and clinical assessments were also carried out. Results: HIV-positive individuals had greater brain-PAD score (mean +/- SD 2.15 +/- 7.79 years) compared to HIV-negative individuals (20.87 +/- 8.40 years; b = 3.48, p < 0.01). Increased brainPAD score was associated with decreased performance in multiple cognitive domains (information processing speed, executive function, memory) and general cognitive performance across all participants. Brain-PAD score was not associated with age, duration of HIV infection, or other HIV-related measures. Conclusion: Increased apparent brain aging, predicted using neuroimaging, was observed in HIV-positive adults, despite effective viral suppression. Furthermore, the magnitude of increased apparent brain aging related to cognitive deficits. However, predicted brain age difference did not correlate with chronological age or duration of HIV infection, suggesting that HIV disease may accentuate rather than accelerate brain aging
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