Human 3D cellular model of hypoxic brain injury of prematurity.

Owing to recent medical and technological advances in neonatal care, infants born extremely premature have increased survival rates1,2. After birth, these infants are at high risk of hypoxic episodes because of lung immaturity, hypotension and lack of cerebral-flow regulation, and can develop a severe condition called encephalopathy of prematurity3. Over 80% of infants born before post-conception week 25 have moderate-to-severe long-term neurodevelopmental impairments4. The susceptible cell types in the cerebral cortex and the molecular mechanisms underlying associated gray-matter defects in premature infants remain unknown. Here we used human three-dimensional brain-region-specific organoids to study the effect of oxygen deprivation on corticogenesis. We identified specific defects in intermediate progenitors, a cortical cell type associated with the expansion of the human cerebral cortex, and showed that these are related to the unfolded protein response and changes. Moreover, we verified these findings in human primary cortical tissue and demonstrated that a small-molecule modulator of the unfolded protein response pathway can prevent the reduction in intermediate progenitors following hypoxia. We anticipate that this human cellular platform will be valuable for studying the environmental and genetic factors underlying injury in the developing human brain

Swainsonine Biosynthesis Genes in Diverse Symbiotic and Pathogenic Fungi

Swainsonine—a cytotoxic fungal alkaloid and a potential cancer therapy drug—is produced by the insect pathogen and plant symbiont Metarhizium robertsii, the clover pathogen Slafractonia leguminicola, locoweed symbionts belonging to Alternaria sect. Undifilum, and a recently discovered morning glory symbiont belonging to order Chaetothyriales. Genome sequence analyses revealed that these fungi share orthologous gene clusters, designated “SWN,” which included a multifunctional swnKgene comprising predicted adenylylation and acyltransferase domains with their associated thiolation domains, a β-ketoacyl synthase domain, and two reductase domains. The role of swnK was demonstrated by inactivating it in M. robertsii through homologous gene replacement to give a ∆swnK mutant that produced no detectable swainsonine, then complementing the mutant with the wild-type gene to restore swainsonine biosynthesis. Other SWN cluster genes were predicted to encode two putative hydroxylases and two reductases, as expected to complete biosynthesis of swainsonine from the predicted SwnK product. SWN gene clusters were identified in six out of seven sequenced genomes of Metarhzium species, and in all 15 sequenced genomes of Arthrodermataceae, a family of fungi that cause athlete’s foot and ringworm diseases in humans and other mammals. Representative isolates of all of these species were cultured, and all Metarhizium spp. with SWN clusters, as well as all but one of the Arthrodermataceae, produced swainsonine. These results suggest a new biosynthetic hypothesis for this alkaloid, extending the known taxonomic breadth of swainsonine producers to at least four orders of Ascomycota, and suggest that swainsonine has roles in mutualistic symbioses and diseases of plants and animals

Sewer System Alternatives Evaluation for Potential Creswell Area Expansion in Harford County

Final project for ENCE422: Project Cost Accounting and Economics (Fall 2018). University of Maryland, College Park.This report summarizes the findings of the ENCE422 Fall 2018 class term project. Students were tasked with evaluating sewer system alternatives for the Creswell area expansion in Harford County. Student groups were to consider environmental impacts, community/social impacts, and perform financial analysis for the alternatives they chose to evaluate. This report extracts information from 14 separate team presentations and synthesizes it around the following structure; 1. Systems that Utilize Septic Tanks a. Traditional Septic System b. Orenco Effluent System c. Small Diameter Gravity Sewer System 2. System that Do Not Utilize Septic Tanks a. Traditional Gravity System b. Vacuum System c. Grinder Pump SystemHarford Count

Human 3D cellular model of hypoxic brain injury of prematurity.

Owing to recent medical and technological advances in neonatal care, infants born extremely premature have increased survival rates1,2. After birth, these infants are at high risk of hypoxic episodes because of lung immaturity, hypotension and lack of cerebral-flow regulation, and can develop a severe condition called encephalopathy of prematurity3. Over 80% of infants born before post-conception week 25 have moderate-to-severe long-term neurodevelopmental impairments4. The susceptible cell types in the cerebral cortex and the molecular mechanisms underlying associated gray-matter defects in premature infants remain unknown. Here we used human three-dimensional brain-region-specific organoids to study the effect of oxygen deprivation on corticogenesis. We identified specific defects in intermediate progenitors, a cortical cell type associated with the expansion of the human cerebral cortex, and showed that these are related to the unfolded protein response and changes. Moreover, we verified these findings in human primary cortical tissue and demonstrated that a small-molecule modulator of the unfolded protein response pathway can prevent the reduction in intermediate progenitors following hypoxia. We anticipate that this human cellular platform will be valuable for studying the environmental and genetic factors underlying injury in the developing human brain

Neonatal Tbr1 Dosage Controls Cortical Layer 6 Connectivity.

An understanding of how heterozygous loss-of-function mutations in autism spectrum disorder (ASD) risk genes, such as TBR1, contribute to ASD remains elusive. Conditional Tbr1 deletion during late mouse gestation in cortical layer 6 neurons (Tbr1layer6 mutants) provides novel insights into its function, including dendritic patterning, synaptogenesis, and cell-intrinsic physiology. These phenotypes occur in heterozygotes, providing insights into mechanisms that may underlie ASD pathophysiology. Restoring expression of Wnt7b largely rescues the synaptic deficit in Tbr1layer6 mutant neurons. Furthermore, Tbr1layer6 heterozygotes have increased anxiety-like behavior, a phenotype seen ASD. Integrating TBR1 chromatin immunoprecipitation sequencing (ChIP-seq) and RNA sequencing (RNA-seq) data from layer 6 neurons and activity of TBR1-bound candidate enhancers provides evidence for how TBR1 regulates layer 6 properties. Moreover, several putative TBR1 targets are ASD risk genes, placing TBR1 in a central position both for ASD risk and for regulating transcriptional circuits that control multiple steps in layer 6 development essential for the assembly of neural circuits