Background: Genome-wide association studies (GWAS) have identified over 1,000 blood pressure (BP) loci and over 80 loci for Alzheimer's disease (AD). Considering BP is an AD risk factor, identifying pleiotropy in BP and cognitive performance measures may indicate mechanistic links between BP and AD.
Methods: Genome-wide scans for pleiotropy in BP variables-systolic (SBP), diastolic (DBP), mean arterial (MAP), and pulse pressure (PP)-and co-calibrated scores for cognitive domains (executive function, language, and memory) were performed using generalized linear mixed models and 116,075 longitudinal measures from 25,726 participants of clinic-based and prospective cohorts.
Importance: "SuperAgers" are oldest-old adults (ages 80+) whose memory performance resembles that of adults in their 50s to mid-60s. Factors underlying their exemplary memory are underexplored in large, racially diverse cohorts.
Objective: To determine the frequency of genotypes in non-Hispanic Black and non-Hispanic White SuperAgers compared to middle-aged (ages 50-64), old (ages 65-79), and oldest-old (ages 80+) controls and Alzheimer's disease (AD) dementia cases.
Introduction: Accurately assessing temporal order of cognitive decline across multiple domains is critical in Alzheimer's disease (AD). Existing literature presented controversial conclusions likely due to the use of a single cohort and different analytical strategies.
Methods: Harmonized composite cognitive measures in memory, language and executive functions from 13 cohorts in the ADSP-PHC data are used.
Background/objectives: Given that adolescents watch Mukbang (eating broadcast) more frequently than other age groups, interest in the potential health effects of watching Mukbang and Cookbang (cooking broadcast) is growing. This study aimed to determine the status of watching Mukbang and Cookbang among Korean adolescents and its relationship with their dietary behaviors.
Subjects/methods: We used data from the 18th Korea Youth Risk Behavior Survey, conducted in 2022 (n = 51,850).
Repeated measure data design has been used extensively in a wide range of fields, such as brain aging or developmental psychology, to answer important research questions exploring relationships between trajectory of change and external variables. In many cases, such data may be collected from multiple study cohorts and harmonized, with the intention of gaining higher statistical power and enhanced external validity. When psychological constructs are measured using survey scales, a fundamental psychometric challenge for data harmonization is to create commensurate measures for the constructs of interest across studies.
View Article and Find Full Text PDFIntroduction: We sought to determine structural magnetic resonance imaging (MRI) characteristics across subgroups defined based on relative cognitive domain impairments using data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) and to compare cognitively defined to imaging-defined subgroups.
Methods: We used data from 584 people with Alzheimer's disease (AD) (461 amyloid positive, 123 unknown amyloid status) and 118 amyloid-negative controls. We used voxel-based morphometry to compare gray matter volume (GMV) for each group compared to controls and to AD-Memory.
Introduction: Although large-scale genome-wide association studies (GWAS) have been conducted on AD, few have been conducted on continuous measures of memory performance and memory decline.
Methods: We conducted a cross-ancestry GWAS on memory performance (in 27,633 participants) and memory decline (in 22,365 participants; 129,201 observations) by leveraging harmonized cognitive data from four aging cohorts.
Results: We found high heritability for two ancestry backgrounds.
Background: Women demonstrate a memory advantage when cognitively healthy yet lose this advantage to men in Alzheimer's disease. However, the genetic underpinnings of this sex difference in memory performance remain unclear.
Methods: We conducted the largest sex-aware genetic study on late-life memory to date (N = 11,942; N = 15,641).
Background: More than 75 common variant loci account for only a portion of the heritability for Alzheimer's disease (AD). A more complete understanding of the genetic basis of AD can be deduced by exploring associations with AD-related endophenotypes.
Methods: We conducted genome-wide scans for cognitive domain performance using harmonized and co-calibrated scores derived by confirmatory factor analyses for executive function, language, and memory.
Objective: To calibrate cognitive assessment data across multiple waves of the Framingham Heart Study (FHS), addressing study design considerations, ceiling effects, and measurement precision.
Method: FHS participants completed several cognitive assessments including screening instruments and more comprehensive batteries at different study visits. We used expert opinion to assign each cognitive test item to a single domain-memory, executive function, language, visuospatial abilities, or none of the above.
Alzheimers Dement (N Y)
December 2020
Introduction: Composite scores may be useful to summarize overall language or visuospatial functioning in studies of older adults.
Methods: We used item response theory to derive composite measures for language (ADNI-Lan) and visuospatial functioning (ADNI-VS) from the cognitive battery administered in the Alzheimer's Disease Neuroimaging Initiative (ADNI). We evaluated the scores among groups of people with normal cognition, mild cognitive impairment (MCI), and Alzheimer's disease (AD) in terms of responsiveness to change, association with imaging findings, and ability to differentiate between MCI participants who progressed to AD dementia and those who did not progress.
Objectives: To characterize the extent to which brief cognitive assessments administered in the population-representative U.S. Health and Retirement Study (HRS) and its International Partner Studies can be considered to be measuring a single, unidimensional latent cognitive function construct.
View Article and Find Full Text PDFBackground: Practice effects (PEs) are improvements in performance after repeated exposure to test materials, and typically viewed as a source of bias in repeated cognitive assessments. We aimed to determine whether characterizing PEs could also provide a useful marker of early cognitive decline.
Methods: We conducted a systematic review of the literature, searching PsycInfo (Ebsco) and PubMed databases for articles studying PEs in aging and dementia populations.
This article was originally published under standard licence, but has now been made available under a [CC BY 4.0] license. The PDF and HTML versions of the paper have been modified accordingly.
View Article and Find Full Text PDFPurpose: This study explored how typically developing 1st grade African American English (AAE) speakers differ from mainstream American English (MAE) speakers in the completion of 2 common phonological awareness tasks (rhyming and phoneme segmentation) when the stimulus items were consonant-vowel-consonant-consonant (CVCC) words and nonwords.
Method: Forty-nine 1st graders met criteria for 2 dialect groups: AAE and MAE. Three conditions were tested in each rhyme and segmentation task: Real Words No Model, Real Words With a Model, and Nonwords With a Model.
Bull Environ Contam Toxicol
June 2016
Drainage systems are integral parts of agricultural landscapes and have the ability to intercept nutrient loading from runoff to surface water. This study investigated nutrient removal efficiency within replicated experimental agricultural drainage ditches during a simulated summer runoff event. Study objectives were to examine the influence of routine mowing of vegetated ditches on nutrient mitigation and to assess spatial transformation of nutrients along ditch length.
View Article and Find Full Text PDFPlant cell wall degradation into fermentable sugars by cellulases is one of the greatest barriers to biofuel production. Expansin protein loosens the plant cell wall by opening up the complex of cellulose microfibrils and polysaccharide matrix components thereby increasing its accessibility to cellulases. We over-expressed cucumber expansin in maize kernels to produce enough protein to assess its potential to serve as an industrial enzyme for applications particularly in biomass conversion.
View Article and Find Full Text PDF