Meta-analysis of Gender Performance Gaps in Undergraduate Natural Science Courses.

To investigate patterns of gender-based performance gaps, we conducted a meta-analysis of published studies and unpublished data collected across 169 undergraduate biology and chemistry courses. While we did not detect an overall gender gap in performance, heterogeneity analyses suggested further analysis was warranted, so we investigated whether attributes of the learning environment impacted performance disparities on the basis of gender. Several factors moderated performance differences, including class size, assessment type, and pedagogy.

Classification of a Hypervirulent Pathotype Responsible for Epidemic Outbreaks in Warm-Water Fishes.

Lineages of hypervirulent (vAh) are the cause of persistent outbreaks of motile septicemia in warm-water fishes worldwide. Over the last decade, this virulent lineage of has resulted in annual losses of millions of tons of farmed carp and catfish in the People's Republic of China and the United States (US). Multiple lines of evidence indicate US catfish and Asian carp isolates of affiliated with sequence type 251 (ST251) share a recent common ancestor.