School-based racial segregation, social support, and late-life cognitive function in the Study of Healthy Aging in African Americans (STAR).

INTRODUCTION: School-based social support for Black students may mediate or modify the association between school segregation and late-life cognition. METHODS: Study of Healthy Aging in African Americans participants (n = 574) reported segregated school attendance and school-based social support. Associations of segregated schooling with domain-specific cognitive outcomes and effect modification or mediation by school-based social support were evaluated with linear mixed models. RESULTS: Segregated school attendance was associated with increased likelihood of school-based social support. Segregated (vs. desegregated in 6th grade) school attendance was associated with lower executive function (ß = -0.18 [-0.34, -0.02]) and semantic memory z-scores (ß = -0.31 [-0.48, -0.13]). Social support did not mediate these associations. Estimates for segregated school attendance were attenuated among those who felt supported, although there was limited evidence of statistically significant effect modification. DISCUSSION: Early-childhood school segregation was associated with poorer cognitive function. Sources of resilience within racialized educational experiences should be further evaluated to bridge inequities. HIGHLIGHTS: School segregation is a form of structural racism that affected the educational experiences of Black youth with potentially lasting consequences for healthy brain aging. Black students who attended a segregated school experienced greater school-based social support, which may highlight a potential source of resilience and resistance against the effects of racism-related stressors on cognitive function. The estimated adverse association between attending a segregated school on cognition was larger for students without an adult at school who cared about them versus those with an adult at school who cared about them, but estimates were imprecise.

What is the association between adverse childhood experiences and late-life cognitive decline? Study of Healthy Aging in African Americans (STAR) cohort study.

OBJECTIVES: Adverse childhood experiences (ACEs) are associated with higher risk of chronic disease, but little is known about the association with late life cognitive decline. We examined the longitudinal association between ACEs and late-life cognitive decline in the Study of Healthy Aging in African Americans (STAR). DESIGN: Linear mixed models with random intercepts and slope examined the association of individual and composite ACEs with cognitive change adjusting for years from baseline (timescale), baseline age, sex, parental education, childhood socioeconomic status and childhood social support. Participants reported whether they had experienced nine types of ACEs. Executive function and verbal episodic memory were measured up to three times over a 3-year period using the Spanish and English Neuropsychological Assessment Scales. SETTINGS: Kaiser Permanente Northern California members living in the Bay Area. PARTICIPANTS: STAR is a cohort study of cognitive ageing launched in 2018 that has enrolled 764 black Americans ages ≥50 years (mean age=67.5; SD=8.5). RESULTS: Twenty-one per cent of participants reported no ACEs, 24% one ACE, 20% two ACEs, 17% three ACEs and 17% four or more ACEs. Compared with no ACEs, two ACEs (ß=0.117; 95% CI 0.052 to 0.182), three ACEs (ß=0.075; 95% CI 0.007 to 0.143) and four or more ACEs (ß=0.089; 95% CI 0.002 to 0.158) were associated with less decline in executive function. There were no significant associations between number of ACEs and baseline or longitudinal verbal episodic memory or between individual ACEs and executive function or verbal episodic memory. CONCLUSION: In this cohort of older black Americans, there was no association between ACEs and baseline cognition or cognitive change in verbal episodic memory; however, experiencing ≥ 2 ACEs was associated with less decline in executive function. These results may indicate that participants who survived to age 50+ and experienced ACEs may have cognitive resilience that warrants further investigation.

Rural residence across the life course and late-life cognitive decline in KHANDLE: A causal inference study.

Background: Modifiable risks for dementia are more prevalent in rural populations, yet there is a dearth of research examining life course rural residence on late-life cognitive decline. Methods: The association of rural residence and socioeconomic status (SES) in childhood and adulthood with late-life cognitive domains (verbal episodic memory, executive function, and semantic memory) and cognitive decline in the Kaiser Healthy Aging and Diverse Life Experiences cohort was estimated using marginal structural models with stabilized inverse probability weights. Results: After adjusting for time-varying SES, the estimated marginal effect of rural residence in childhood was harmful for both executive function (ß = -0.19, 95% confidence interval [CI] = -0.32, -0.06) and verbal episodic memory (ß = -0.22, 95% CI = -0.35, -0.08). Effects of adult rural residence were imprecisely estimated with beneficial point estimates for both executive function (ß = 0.19; 95% CI = -0.07, 0.44) and verbal episodic memory (ß = 0.24, 95% CI = -0.07, 0.55). Conclusions: Childhood rurality is associated with poorer late-life cognition independent of SES.

Peptidomic profiling of human milk with LC-MS/MS reveals pH-specific proteolysis of milk proteins.

Human milk is a dynamic protein-protease system that delivers bioactive peptides to infants. The pH of milk changes from the mother's mammary gland to the infant's digestive tract. Although the release of human milk peptides has been studied during in vivo or in vitro digestion, these models did not explicitly vary nor observe the effect of pH. The objective of this research was to determine the effect of pH on the proteolysis of human milk. Using high-resolution accurate-mass Orbitrap mass spectrometry, profiles of endogenous human milk peptides before and after incubation at various pH levels have been mapped. Over 5000 peptides were identified. Comparative analyses classified 74 peptides that were consistently found independent of pH alterations, and 8 peptides that were released only at pH 4 or 5 (typical infant gastric pH). Results documented that the proteolysis of milk proteins, particularly ß-casein, polymeric immunoglobulin receptor, and α-lactalbumin, is pH-dependent.

Draft Genome Sequences of Shewanella sp. Strain UCD-FRSP16_17 and Nine Vibrio Strains Isolated from Abalone Feces.

We present here the draft genome sequences for nine strains of Vibrio (V. cyclitrophicus, V. splendidus, V. tasmaniensis, and three unidentified) and one Shewanella strain. Strains were isolated from red (Haliotis rufescens) and white (Haliotis sorenseni) abalone, with and without exposure to "Candidatus Xenohaliotis californiensis," the causative agent of abalone withering syndrome.