Demystifying the 'hidden curriculum' for minoritized graduate students.

Graduate programs in the biomedical sciences dedicate considerable resources to recruiting students from underrepresented racial and ethnic groups. However, students from these minoritized groups have decreased access to the 'hidden curriculum' that must be navigated in order to be successful in graduate school. Here, we describe a student-led initiative at Johns Hopkins University, the Hidden Curriculum Symposium, that is organized to help prepare new students from underrepresented groups for graduate school. Preliminary evidence from surveys suggests that the initiative does increase the preparedness of minoritized students, and we believe this approach could also prove useful at other academic institutions.

Pharmacological activation of the Sonic hedgehog pathway with a Smoothened small molecule agonist ameliorates the severity of alcohol-induced morphological and behavioral birth defects in a zebrafish model of fetal alcohol spectrum disorder.

Ethanol exposure during the early stages of embryonic development can lead to a range of morphological and behavioral differences termed fetal alcohol spectrum disorders (FASDs). In a zebrafish model, we have shown that acute ethanol exposure at 8-10 hr postfertilization (hpf), a critical time of development, produces birth defects similar to those clinically characterized in FASD. Dysregulation of the Sonic hedgehog (Shh) pathway has been implicated as a molecular basis for many of the birth defects caused by prenatal alcohol exposure. We observed in zebrafish embryos that shh expression was significantly decreased by ethanol exposure at 8-10 hpf, while smo expression was much less affected. Treatment of zebrafish embryos with SAG or purmorphamine, small molecule Smoothened agonists that activate Shh signaling, ameliorated the severity of ethanol-induced developmental malformations including altered eye size and midline brain development. Furthermore, this rescue effect of Smo activation was dose dependent and occurred primarily when treatment was given after ethanol exposure. Markers of Shh signaling (gli1/2) and eye development (pax6a) were restored in embryos treated with SAG post-ethanol exposure. Since embryonic ethanol exposure has been shown to produce later-life neurobehavioral impairments, juvenile zebrafish were examined in the novel tank diving test. Our results further demonstrated that in zebrafish embryos exposed to ethanol, SAG treatment was able to mitigate long-term neurodevelopmental impairments related to anxiety and risk-taking behavior. Our results indicate that pharmacological activation of the Shh pathway at specific developmental timing markedly diminishes the severity of alcohol-induced birth defects.

Are we close to knowing the plant diversity of the Amazon?

Amazonia is often cited as having the most diverse flora on the planet. However, the total number of species of higher plants in the region has been largely a matter of guesswork. Some recent publications have estimated the total number of species present, which indicate a lower overall diversity than was estimated in the past. However, analysis of the sampling density across the region, and data from various sources suggest that there may be reason why the recent figures may be considerable underestimates. I believe that much more investment in extensive collecting of quality plant specimens is needed to encounter the very large number of rare and local species that might never have been collected. Unfortunately the tendencies of investment in botany, in terms of geography and types of project, suggest that we will probably not be able to accurately assess the real diversity of the region.