Access to Healthy Built and Natural Environments and Physical Activity and Screen Time in New Zealand Adolescents: A Geospatial Cross-Sectional Study.

The built and natural environment can facilitate (un)healthy behaviors in adolescence. However, most previous studies have focused on examining associations between singular aspects of the environment. This study examined the association between the mixture of health-promoting and health-constraining environmental features in a Healthy Location Index (HLI) and physical activity and screen time among adolescents.

Characterizing selection on complex traits through conditional frequency spectra.

Natural selection on complex traits is difficult to study in part due to the ascertainment inherent to genome-wide association studies (GWAS). The power to detect a trait-associated variant in GWAS is a function of frequency and effect size - but for traits under selection, the effect size of a variant determines the strength of selection against it, constraining its frequency. Recognizing the biases inherent to GWAS ascertainment, we propose studying the joint distribution of allele frequencies across populations, conditional on the frequencies in the GWAS cohort.

Nascent matrix deposition supports alveolar organoid formation from aggregates in synthetic hydrogels.

Human induced pluripotent stem cell (iPSC)-derived alveolar organoids have emerged as a system to model the alveolar epithelium in homeostasis and disease. However, alveolar organoids are typically grown in Matrigel, a mouse sarcoma-derived basement membrane matrix that offers poor control over matrix properties, prompting the development of synthetic hydrogels as a Matrigel alternative. Here, we develop a two-step culture method that involves pre-aggregation of organoids in hydrogel-based microwells followed by embedding in a synthetic hydrogel that supports alveolar organoid growth, while also offering considerable control over organoid and hydrogel properties.

Initial participant perspectives about participating in an online, semi-supervised, cirrhosis-specific nutrition and exercise intervention.

Objectives: In chronic diseases, there have been issues with low levels of participant adherence and retention during well-supported lifestyle behaviour change interventional studies. Theoretically informed, the objective was to explore the types of challenges participants are experiencing to inform future designs.

Design: We conducted an exploratory descriptive study in an adult cirrhosis population after the first 4-6 weeks of a 12-week semi-supervised nutrition and exercise online program.