Prenatal AAV9-GFP administration in fetal lambs results in transduction of female germ cells and maternal exposure to virus.

Prenatal somatic cell gene therapy (PSCGT) could potentially treat severe, early-onset genetic disorders such as spinal muscular atrophy (SMA) or muscular dystrophy. Given the approval of adeno-associated virus serotype 9 (AAV9) vectors in infants with SMA by the U.S. Food and Drug Administration, we tested the safety and biodistribution of AAV9-GFP (clinical-grade and dose) in fetal lambs to understand safety and efficacy after umbilical vein or intracranial injection on embryonic day 75 (E75) . Umbilical vein injection led to widespread biodistribution of vector genomes in all examined lamb tissues and in maternal uteruses at harvest (E96 or E140; term = E150). There was robust GFP expression in brain, spinal cord, dorsal root ganglia (DRGs), without DRG toxicity and excellent transduction of diaphragm and quadriceps muscles. However, we found evidence of systemic toxicity (fetal growth restriction) and maternal exposure to the viral vector (transient elevation of total bilirubin and a trend toward elevation in anti-AAV9 antibodies). There were no antibodies against GFP in ewes or lambs. Analysis of fetal gonads demonstrated GFP expression in female (but not male) germ cells, with low levels of integration-specific reads, without integration in select proto-oncogenes. These results suggest potential therapeutic benefit of AAV9 PSCGT for neuromuscular disorders, but warrant caution for exposure of female germ cells.

Estimating the range of the maximum hormetic stimulatory response.

An ever-expanding hormetic database (HDB) was used to demonstrate that the median maximal hormetic stimulatory response (MHSR) of biphasic dose-response relationships increases in value with an increase in the number of stimulatory doses/concentrations that are administered below the estimated threshold/ZEP (zero equivalent point - i.e., the dose where the response crosses the control group value). With only one dose or concentration administered below the ZEP, the median MHSR for microbes (in vitro), animals (in vitro and in vivo), and plants (in vitro and in vivo) ranged between 120% and 125% of the control response. However, when individual agents having at least six doses below the ZEP were mined from the HDB (and a median MHSR then determined), the median MHSR increased to 160-190%. This progressive increase in the MHSR appears to be due to several factors, including (i) the enhanced capacity of additional doses in the stimulatory hormetic zone to better estimate the response optima, and (ii) enhanced variability due to the presence of more doses in the stimulatory zone. This study offers a novel perspective for improving research protocols, unraveling the limits of biological plasticity, understanding low-level stress biology, advancing human and ecological health, and enhancing human performance.

A Mixed-Methods Investigation of Clicker Implementation Styles in STEM.

Active learning with clickers is a common approach in high-enrollment, lecture-based courses in science, technology, engineering, and mathematics. In this study, we describe the procedures that faculty at one institution used when implementing clicker-based active learning, and how they situated these activities in their class sessions. Using a mixed-methods approach, we categorized faculty into four implementation styles based on quantitative observation data and conducted qualitative interviews to further understand why faculty used these styles. We found that faculty tended to use similar procedures when implementing a clicker activity, but differed on how they situated the clicker-based active learning into their courses. These variations were attributed to different faculty goals for using clicker-based active learning, with some using it to engage students at specific time points throughout their class sessions and others who selected it as the best way to teach a concept from several possible teaching techniques. Future research should continue to investigate and describe how active-learning strategies from literature may differ from what is being implemented.

Parent-offspring behavior of Jambu fruit doves (Ptilinopus jambu).

Fruit doves (Ptilinopus) constitute a genus of small to medium-sized, brightly colored arboreal birds, whose diets consist entirely of fruit. Little is known about the behavior of fruit doves because most species inhabit dense forests and are difficult to observe in the wild. This study describes the parental behavior of Jambu fruit dove pairs (Ptilinopus jambu) in a captive breeding program at the Saint Louis Zoo. Continuous video recordings were made of three pairs which raised a total of eight squabs over 2 years; daily rates of parental and squab behaviors were quantified. Overall, females were present at the nest, brooded their squabs, pecked, and attempted feedings more often than males. Parents also cared for their squabs at different times throughout the day. Males fed and brooded squabs during the middle of the day, while females fed throughout the day and brooded in the morning, evening, and overnight. Feeding rates were lower than those described for seed-eating doves (Columbinae), with hours between consecutive feedings, and squabs rarely begged before feeding events. Most squab behaviors involved initiating or terminating brooding and self-preening. These behaviors increased as squabs approached fledging, and coincided with a shift from full to partial brooding, and a decrease in parental allopreening. Older squabs also initiated feeding less frequently. Together, these data provide the first description of parental behavior in a Ptilinopus fruit dove. The results of this study may help improve captive breeding efforts, which are likely to become increasingly important for future conservation and reintroduction programs.