The Power of Open: Benefits, Barriers, and Strategies for Integration of Open Educational Resources

Open Educational Resources (OER) are becoming a significant, mission-driven trend within educational literature. To help address rising costs, instructors and designers are looking to OER to effectively replace traditional instructional content, which requires more than just identify and replace. Drawing from 51 OER studies conducted in countries across the five continents, this systematic literature review explored the empirical themes evident in the current research on a global scale. This review found (1) discoverability, sustainability, and remixing are significant barriers that stand in the way of OER disrupting traditional textbook models; (2) there is no significant difference in learning outcomes when instructors incorporate OER; and (3) implementation of OER as instructional strategies is challenging but can be effective in supporting positive learning outcomes when properly designed. The paper concludes with a discussion of gaps in the literature, considerations for implementation and further directions for future research

Megaesophagus in a Line of Transgenic Rats: A Model of Achalasia

Megaesophagus is defined as the abnormal enlargement or dilatation of the esophagus, characterized by a lack of normal contraction of the esophageal walls. This is called achalasia when associated with reduced or no relaxation of the lower esophageal sphincter (LES). To date, there are few naturally occurring models for this disease. A colony of transgenic (Pvrl3-Cre) rats presented with megaesophagus at 3 to 4 months of age; further breeding studies revealed a prevalence of 90% of transgene-positive animals having megaesophagus. Affected rats could be maintained on a total liquid diet long term and were shown to display the classic features of dilated esophagus, closed lower esophageal sphincter, and abnormal contractions on contrast radiography and fluoroscopy. Histologically, the findings of muscle degeneration, inflammation, and a reduced number of myenteric ganglia in the esophagus combined with ultrastructural lesions of muscle fiber disarray and mitochondrial changes in the striated muscle of these animals closely mimic that seen in the human condition. Muscle contractile studies looking at the response of the lower esophageal sphincter and fundus to electrical field stimulation, sodium nitroprusside, and L-nitro-L-arginine methyl ester also demonstrate the similarity between megaesophagus in the transgenic rats and patients with achalasia. No primary cause for megaesophagus was found, but the close parallel to the human form of the disease, as well as ease of care and manipulation of these rats, makes this a suitable model to better understand the etiology of achalasia as well as study new management and treatment options for this incurable condition.National Institutes of Health (U.S.) (Grant T32OD011141)National Institutes of Health (U.S.) (Grant P30ES002109

Genes of Both Parental Origins Are Differentially Involved in Early Embryogenesis of a Tobacco Interspecies Hybrid

BACKGROUND: In animals, early embryonic development is largely dependent on maternal transcripts synthesized during gametogenesis. However, in higher plants, the extent of maternal control over zygote development and early embryogenesis is not fully understood yet. Nothing is known about the activity of the parental genomes during seed formation of interspecies hybrids. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report that an interspecies hybridization system between SR1 (Nicotiana tabacum) and Hamayan (N. rustica) has been successfully established. Based on the system we selected 58 genes that have polymorphic sites between SR1 and Hamayan, and analyzed the allele-specific expression of 28 genes in their hybrid zygotes (Hamayan x SR1). Finally the allele-specific expressions of 8 genes in hybrid zygotes were repeatedly confirmed. Among them, 4 genes were of paternal origin, 1 gene was of maternal origin and 3 genes were of biparental origin. These results revealed obvious biparental involvement and differentially contribution of parental-origin genes to zygote development in the interspecies hybrid. We further detected the expression pattern of the genes at 8-celled embryo stage found that the involvement of the parental-origin genes may change at different stages of embryogenesis. CONCLUSIONS/SIGNIFICANCE: We reveal that genes of both parental origins are differentially involved in early embryogenesis of a tobacco interspecies hybrid and functions in a developmental stage-dependent manner. This finding may open a window to seek for the possible molecular mechanism of hybrid vigor

Insights into the Musa genome: Syntenic relationships to rice and between Musa species

<p>Abstract</p> <p>Background</p> <p><it>Musa </it>species (Zingiberaceae, Zingiberales) including bananas and plantains are collectively the fourth most important crop in developing countries. Knowledge concerning <it>Musa </it>genome structure and the origin of distinct cultivars has greatly increased over the last few years. Until now, however, no large-scale analyses of <it>Musa </it>genomic sequence have been conducted. This study compares genomic sequence in two <it>Musa </it>species with orthologous regions in the rice genome.</p> <p>Results</p> <p>We produced 1.4 Mb of <it>Musa </it>sequence from 13 BAC clones, annotated and analyzed them along with 4 previously sequenced BACs. The 443 predicted genes revealed that Zingiberales genes share GC content and distribution characteristics with eudicot and Poaceae genomes. Comparison with rice revealed microsynteny regions that have persisted since the divergence of the Commelinid orders Poales and Zingiberales at least 117 Mya. The previously hypothesized large-scale duplication event in the common ancestor of major cereal lineages within the Poaceae was verified. The divergence time distributions for <it>Musa</it>-Zingiber (Zingiberaceae, Zingiberales) orthologs and paralogs provide strong evidence for a large-scale duplication event in the <it>Musa </it>lineage after its divergence from the Zingiberaceae approximately 61 Mya. Comparisons of genomic regions from <it>M. acuminata </it>and <it>M. balbisiana </it>revealed highly conserved genome structure, and indicated that these genomes diverged circa 4.6 Mya.</p> <p>Conclusion</p> <p>These results point to the utility of comparative analyses between distantly-related monocot species such as rice and <it>Musa </it>for improving our understanding of monocot genome evolution. Sequencing the genome of <it>M. acuminata </it>would provide a strong foundation for comparative genomics in the monocots. In addition a genome sequence would aid genomic and genetic analyses of cultivated <it>Musa </it>polyploid genotypes in research aimed at localizing and cloning genes controlling important agronomic traits for breeding purposes.</p

Independent freestanding emergency departments and implications for the rural emergency physician workforce in Texas.

OBJECTIVE: Independent freestanding emergency departments (IFEDs) have proliferated over the last decade, largely in Texas. We examined the IFED physician workforce composition and changes in emergency physician workforce supply across states and in rural Texas over the period of IFED proliferation following a 2009 legislation allowing the licensing of these sites. DATA SOURCES: IFED websites, Texas Medical Board lookup tool, National Plan & Provider Enumeration System (NPPES), Provider Enrollment and Chain/Ownership System (PECOS), Medicare Physician Shared Patient Patterns, CareSet DocGraph Hop Teaming, Healthcare Provider Database. STUDY DESIGN: Descriptive analysis of the IFED physician workforce; quasi‐experimental difference‐in‐difference analysis of Texas emergency physician movement into and out of the state; and difference‐in‐difference‐in‐difference analysis of the change in emergency physician supply between rural and urban areas in Texas compared with other states. DATA EXTRACTION METHODS: Using the NPIs obtained through Texas IFED websites and Texas Medical Board data, we examined NPPES/PECOS files, Medicare Physician Shared Patient Patterns, and CareSet DocGraph Hop Teaming for IFED physician practice locations from 2009 to 2017. We extracted all active emergency physicians from a Healthcare Provider Database, derived from a 5% Medicare claims (1999‐2017). PRINCIPAL FINDINGS: In 2019, 545 physicians practiced in Texas IFEDs, of which 515 (94.5%) were emergency physicians. We located 533 in previous practice, of whom 522 (97.9%) previously practiced in Disproportionate Share Hospitals and 100 (18.8%) in rural areas. Following legislation to begin licensing IFEDs in 2009, there were on average 42.1 (P < .01) moving into Texas and 17.0 (P < .01) fewer moving out compared with all other states. Our results also indicated that the difference in emergency physician supply between rural and urban Texas was 1,002 (P < .01) fewer than for other states. CONCLUSIONS: New models of health care organizations such as IFEDs have workforce implications that may further exacerbate rural and underserved workforce and access challenges