Inequity in vaccine access
Rich nations’ plans to administer booster doses of COVID-19 vaccine to people who have been fully vaccinated have drawn criticism from many global health researchers, who highlight the growing disparities between wealth and access to vaccines. A July report from KFF, a health-policy organization based in San Francisco, California, finds that at current vaccination rates, low-income countries won’t achieve substantial levels of protection until at least 2023.
The changing face of ecosystems
Despite alarming declines in some animal and plant species, total biodiversity in many ecosystems is not decreasing. But that doesn’t mean such ecosystems are static. In fact, the mix of species in local communities is changing rapidly almost everywhere on Earth. As some inhabitants disappear, colonizers move in and add to species richness.
Genetics behind the menopause
Genetic variants associated with age at onset of menopause have been identified in a large-scale genomic analysis, findings that bring scientists a step closer to predicting and treating early menopause. When the DNA of egg cells in ovaries is damaged in mice, expression of the gene Chek1 promotes DNA repair, whereas expression of Chek2 promotes destruction of the affected cell. The analysis found that variants of the human equivalent of Chek2 and other genes involved in the response to DNA damage are associated with differences in age at natural menopause. It also showed that mice carrying an extra copy of Chek1, or lacking expression of Chek2, had a longer reproductive age span than did typical mice.