1,080 research outputs found

    Searching for Standards: Disclosure in the Municipal Securities Market

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    Prokrastinering, eller att mot bÀttre vetande skjuta upp nÄgot, Àr ett stort problem i samhÀllet i allmÀnhet och för studenter i synnerhet. I denna artikel beskriver vi en utbildningsmodul om prokrastinering som vi introducerat pÄ tvÄ civilingenjörsprogram pÄ KTH, varav denna rapport behandlar datateknikprogrammet dÀr 466 studenter deltog. UtvÀrderingen hade 100% svarsfrekvens, och visar att 95% av studenterna hade problem med prokrastinering varav 43% hade stora eller mycket stora problem. 88% ansÄg att prokrastinering var ett bra tema att ha med i utbildningen, och 57% ansÄg att momentet haft positiva effekter pÄ deras studievanor. Endast 7% ansÄg att momentet inte hade gett nÄgra mÀrkbara effekter pÄ studierna. DÄ modulen endast krÀver ca 8 timmars arbete frÄn studenternas sida anser vi att fördelarna Àr sÄ stora att denna eller en liknande modul borde ingÄ i samtliga utbildningsprogram.QC 20131216</p

    Assessing Population Structure and Genetic Diversity in US Suffolk Sheep to Define a Framework for Genomic Selection

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    Long-term sustainability of breeds depends on having sufficient genetic diversity for adaptability to change, whether driven by climatic conditions or by priorities in breeding programs. Genetic diversity in Suffolk sheep in the United States was evaluated in four ways: 1) using genetic relationships from pedigree data [(n = 64 310 animals recorded in the US National Sheep Improvement Program (NSIP)]; 2) using molecular data (n = 304 Suffolk genotyped with the OvineHD BeadChip); 3) comparing Australian (n = 109) and Irish (n = 55) Suffolk sheep to those in the United States using molecular data; and 4) assessing genetic relationships (connectedness) among active Suffolk flocks (n = 18) in NSIP. By characterizing genetic diversity, a goal was to define the structure of a reference population for use for genomic selection strategies in this breed. Pedigree-based mean inbreeding level for the most recent year of available data was 5.5%. Ten animals defined 22.8% of the current gene pool. The effective population size (Ne) ranged from 27.5 to 244.2 based on pedigree and was 79.5 based on molecular data. Expected (HE) and observed (HO) heterozygosity were 0.317 and 0.306, respectively. Model-based population structure included 7 subpopulations. From Principal Component Analysis, countries separated into distinct populations. Within the US population, flocks formed genetically disconnected clusters. A decline in genetic diversity over time was observed from both pedigree and genomic-based derived measures with evidence of population substructure as measured by FST. Using these measures of genetic diversity, a framework for establishing a genomic reference population in US Suffolk sheep engaged in NSIP was proposed

    Low Neural Exosomal Levels of Cellular Survival Factors in Alzheimer\u27s Disease

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    Transcription factors that mediate neuronal defenses against diverse stresses were quantified in plasma neural-derived exosomes of Alzheimer\u27s disease or frontotemporal dementia patients and matched controls. Exosomal levels of low-density lipoprotein receptor-related protein 6, heat-shock factor-1, and repressor element 1-silencing transcription factor all were significantly lower in Alzheimer\u27s disease patients than controls (P \u3c 0.0001). In frontotemporal dementia, the only significant difference was higher levels of repressor element 1-silencing transcription factor than in controls. Exosomal transcription factors were diminished 2-10 years before clinical diagnosis of Alzheimer\u27s disease. Low exosomal levels of survival proteins may explain decreased neuronal resistance to Alzheimer\u27s disease neurotoxic proteins

    Does amyloid deposition produce a specific atrophic signature in cognitively normal subjects?☆

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    The objective of our study was to evaluate whether cognitively normal (CN) elderly participants showing elevated cortical beta-amyloid (AÎČ) deposition have a consistent neuroanatomical signature of brain atrophy that may characterize preclinical Alzheimer's disease (AD). 115 CN participants who were AÎČ-positive (CN +) by amyloid PET imaging; 115 CN participants who were AÎČ-negative (CN −); and 88 AÎČ-positive mild cognitive impairment or AD participants (MCI/AD +) were identified. Cortical thickness (FreeSurfer) and gray matter volume (SPM5) were measured for 28 regions-of-interest (ROIs) across the brain and compared across groups. ROIs that best discriminated CN − from CN + differed for FreeSurfer cortical thickness and SPM5 gray matter volume. Group-wise discrimination was poor with a high degree of uncertainty in terms of the rank ordering of ROIs. In contrast, both techniques showed strong and consistent findings comparing MCI/AD + to both CN − and CN + groups, with entorhinal cortex, middle and inferior temporal lobe, inferior parietal lobe, and hippocampus providing the best discrimination for both techniques. Concordance across techniques was higher for the CN − and CN + versus MCI/AD + comparisons, compared to the CN − versus CN + comparison. The weak and inconsistent nature of the findings across technique in this study cast doubt on the existence of a reliable neuroanatomical signature of preclinical AD in elderly PiB-positive CN participants

    Optimizing PiB-PET SUVR change-over-time measurement by a large-scale analysis of longitudinal reliability, plausibility, separability, and correlation with MMSE

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    AbstractQuantitative measurements of change in ÎČ-amyloid load from Positron Emission Tomography (PET) images play a critical role in clinical trials and longitudinal observational studies of Alzheimer's disease. These measurements are strongly affected by methodological differences between implementations, including choice of reference region and use of partial volume correction, but there is a lack of consensus for an optimal method. Previous works have examined some relevant variables under varying criteria, but interactions between them prevent choosing a method via combined meta-analysis. In this work, we present a thorough comparison of methods to measure change in ÎČ-amyloid over time using Pittsburgh Compound B (PiB) PET imaging.MethodsWe compare 1,024 different automated software pipeline implementations with varying methodological choices according to four quality metrics calculated over three-timepoint longitudinal trajectories of 129 subjects: reliability (straightness/variance); plausibility (lack of negative slopes); ability to predict accumulator/non-accumulator status from baseline value; and correlation between change in ÎČ-amyloid and change in Mini Mental State Exam (MMSE) scores.Results and conclusionFrom this analysis, we show that an optimal longitudinal measure of ÎČ-amyloid from PiB should use a reference region that includes a combination of voxels in the supratentorial white matter and those in the whole cerebellum, measured using two-class partial volume correction in the voxel space of each subject's corresponding anatomical MR image

    Brain health: the importance of recognizing cognitive impairment: an IAGG consensus conference

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    Cognitive impairment creates significant challenges for patients, their families and friends, and clinicians who provide their health care. Early recognition allows for diagnosis and appropriate treatment, education, psychosocial support, and engagement in shared decision-making regarding life planning, health care, involvement in research, and financial matters. An IAGG-GARN consensus panel examined the importance of early recognition of impaired cognitive health. Their major conclusion was that case-finding by physicians and health professionals is an important step toward enhancing brain health for aging populations throughout the world. This conclusion is in keeping with the position of the United States' Centers for Medicare and Medicaid Services that reimburses for detection of cognitive impairment as part the of Medicare Annual Wellness Visit and with the international call for early detection of cognitive impairment as a patient's right. The panel agreed on the following specific findings: (1) validated screening tests are available that take 3 to 7 minutes to administer; (2) a combination of patient- and informant-based screens is the most appropriate approach for identifying early cognitive impairment; (3) early cognitive impairment may have treatable components; and (4) emerging data support a combination of medical and lifestyle interventions as a potential way to delay or reduce cognitive decline
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