181 research outputs found
An inline optical electron polarimeter
The design and operation of a simple inline optical electron polarimeter is presented. It is based on exchange excitation of ground state neon atoms. The electron polarization is determined from the degree of circular polarization of the subsequent 2p53p 3D3â2p53s 3P2 (6402 Ă
) fluorescence. This device can characterize both longitudinally and transversely polarized electron beams in a nondestructive fashion, and is inexpensive and easily constructed
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Feasibility and initial efficacy of project-based treatment for people with ABI
Background: Communication impairments are common and pervasive for people a long time following acquired brain injury (ABI). These impairments have a significant impact on a person's quality of life (QOL) postâinjury. Projectâbased treatment is a treatment approach that could have an impact on communication skills and QOL for people with ABI a longâterm postâinjury. This treatment is embedded in a context of meaningful activities chosen by people with ABI, whereby, as a group, they work collaboratively to achieve a tangible end product.
Aims: To evaluate the feasibility and initial efficacy of projectâbased treatment on improving the communication skills and QOL for people with ABI.
Methods & Procedures: An exploratory controlled trial with alternate allocation of groups, and followâup at 6â8 weeks, was completed. Twentyâone people with chronic ABI were recruited in groups of two to three from community settings, allocated to either a TREATMENT (n = 11) or WAITLIST group (n = 10). Participants attended a 20âh groupâbased treatment over 6 weeks where they worked towards achieving a project that helped others. To determine feasibility, four criteria were used: demand, implementation, practicality and acceptability. A range of communication and QOL outcomes was used to determine a fifth feasibility criterion, initial efficacy. Some of these criteria were additionally used to evaluate the feasibility of the outcomes.
Outcomes & Results: All participants received the treatment as allocated with high attendance and no dropouts. The treatment was feasible to deliver as intended and was highly acceptable to participants. Medium and large effect sizes were found from preâ to postâtreatment, and from preâtreatment to followâup for measures of conversation, perceived communicative ability and QOL.
Conclusions & Implications: Projectâbased treatment is feasible with indications of initial efficacy for both communication skills and QOL. The treatment provides a promising new approach for improving communication skills and QOL in people with chronic acquired brain injuries in the community setting
Multigroup Ethnic Identity Measure (MEIM) Expansion: Measuring Racial, Religious, and National Aspects of Sense of Ethnic Identity Within the United Kingdom
These studies examined the degree to which racial, religious, and national aspects of individuals' sense of ethnic identity stand as interrelated, yet distinct, constructs. Results of exploratory factor analyses in Study 1 (n = 272) revealed that a three-factor model specifying racial, religious, and national identities yielded optimal fit to correlational data from an expanded, 36-item version of the Multigroup Ethnic Identity Measure (MEIM; Roberts et al., 1999), although results left room for improvement in model fit. Subsequently, results of confirmatory factor analyses in Study 2 (n = 291) revealed that, after taking covariance among the items into account, a six-factor model specifying exploration and commitment dimensions within each of the racial, religious, and national identity constructs provided optimal fit. Implications for the utility of Goffman's (1963b) interactionist role theory and Erikson's (1968) ego psychology for understanding the full complexity of felt ethnic identity are discussed
Genetic Control of Organ Shape and Tissue Polarity
A combination of experimental analysis and mathematical modelling shows how the genetic control of tissue polarity plays a fundamental role in the development and evolution of form
Blood Leukocyte DNA Methylation Predicts Risk of Future Myocardial Infarction and Coronary Heart Disease
BACKGROUND: DNA methylation is implicated in coronary heart disease (CHD), but current evidence is based on small, cross-sectional studies. We examined blood DNA methylation in relation to incident CHD across multiple prospective cohorts. METHODS: Nine population-based cohorts from the United States and Europe profiled epigenome-wide blood leukocyte DNA methylation using the Illumina Infinium 450k microarray, and prospectively ascertained CHD events including coronary insufficiency/unstable angina, recognized myocardial infarction, coronary revascularization, and coronary death. Cohorts conducted race-specific analyses adjusted for age, sex, smoking, education, body mass index, blood cell type proportions, and technical variables. We conducted fixed-effect meta-analyses across cohorts. RESULTS: Among 11 461 individuals (mean age 64 years, 67% women, 35% African American) free of CHD at baseline, 1895 developed CHD during a mean follow-up of 11.2 years. Methylation levels at 52 CpG (cytosine-phosphate-guanine) sites were associated with incident CHD or myocardial infarction (false discovery rate<0.05). These CpGs map to genes with key roles in calcium regulation (ATP2B2, CASR, GUCA1B, HPCAL1), and genes identified in genome- and epigenome-wide studies of serum calcium (CASR), serum calcium-related risk of CHD (CASR), coronary artery calcified plaque (PTPRN2), and kidney function (CDH23, HPCAL1), among others. Mendelian randomization analyses supported a causal effect of DNA methylation on incident CHD; these CpGs map to active regulatory regions proximal to long non-coding RNA transcripts. CONCLUSION: Methylation of blood-derived DNA is associated with risk of future CHD across diverse populations and may serve as an informative tool for gaining further insight on the development of CHD
DNA methylation-based measures of biological age:meta-analysis predicting time to death
Estimates of biological age based on DNA methylation patterns, often referred to as "epigenetic age", "DNAm age", have been shown to be robust biomarkers of age in humans. We previously demonstrated that independent of chronological age, epigenetic age assessed in blood predicted all-cause mortality in four human cohorts. Here, we expanded our original observation to 13 different cohorts for a total sample size of 13,089 individuals, including three racial/ethnic groups. In addition, we examined whether incorporating information on blood cell composition into the epigenetic age metrics improves their predictive power for mortality. All considered measures of epigenetic age acceleration were predictive of mortality (p †8.2 x 10-9), independent of chronological age, even after adjusting for additional risk factors (p < 5.4 x 10-4), and within the racial/ethnic groups that we examined (non-Hispanic whites, Hispanics, African Americans). Epigenetic age estimates that incorporated information on blood cell composition led to the smallest p-values for time to death (p†7.5 x 10-43). Overall, this study a) strengthens the evidence that epigenetic age predicts all-cause mortality above and beyond chronological age and traditional risk factors, and b) demonstrates that epigenetic age estimates that incorporate information on blood cell counts lead to highly significant associations with all-cause mortality
Statistical and integrative system-level analysis of DNA methylation data
Epigenetics plays a key role in cellular development and function. Alterations to the epigenome are thought to capture and mediate the effects of genetic and environmental risk factors on complex disease. Currently, DNA methylation is the only epigenetic mark that can be measured reliably and genome-wide in large numbers of samples. This Review discusses some of the key statistical challenges and algorithms associated with drawing inferences from DNA methylation data, including cell-type heterogeneity, feature selection, reverse causation and system-level analyses that require integration with other data types such as gene expression, genotype, transcription factor binding and other epigenetic information
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