Controls on Microbial and Oolitic Carbonate Sedimentation and Stratigraphic Cyclicity Within a Mixed Carbonate-Siliciclastic System: Upper Cambrian Wilberns Formation, Llano Uplift, Mason County, Texas, USA

The upper Cambrian Wilberns Formation in central Texas records deposition on a low-gradient shelf within a mixed carbonate–siliciclastic tidal-flat system that changes offshore to subtidal shelf and open-marine oolitic skeletal shoals with large microbial mounds. Siliciclastic sediment is interpreted to have been delivered to the tidal flat by aeolian processes because of the narrow range in grain size and paucity of clay. Tidal influence is dominant as evidenced by reversing currents and desiccation on the tidal flat, and megaripples with reversing current indicators in offshore shoals. Intraclastic conglomerates were deposited in broad channels on the tidal flats during storm surges. Microbialite deposition is interpreted to be controlled by accommodation favouring amalgamated thin biostromes developed in the tidal flat vs. larger mounds with greater synoptic relief in the offshore, and current energy resulting in preferential elongation of offshore mounds in a NE–SW orientation. Intertidal mounds and biostromes grew in the presence of significant siliciclastic flux and trapped it within their structure, whereas offshore large buildups incorporated little siliciclastic component. Oolite and skeletal grainstone formed in tide agitated shoals associated with large subtidal microbial mounds. Storms extensively recycled and redistributed skeletal and oolitic sands from the offshore shoals across the shelf as thin sand sheets. Spatial mixing of siliciclastic and carbonate sediment occurred across the tidal flat and shelf. Low-frequency and intermediate-frequency stratigraphic cycles were driven by shifts in the shoreline and changes in rate of siliciclastic flux in response to relative sea-level fluctuation. Random facies stacking and the lack of metre-scale cyclicity are interpreted to reflect stratigraphic incompleteness and an episodic signal introduced by storms

CpG-creating mutations are costly in many human viruses.

Mutations can occur throughout the virus genome and may be beneficial, neutral or deleterious. We are interested in mutations that yield a C next to a G, producing CpG sites. CpG sites are rare in eukaryotic and viral genomes. For the eukaryotes, it is thought that CpG sites are rare because they are prone to mutation when methylated. In viruses, we know less about why CpG sites are rare. A previous study in HIV suggested that CpG-creating transition mutations are more costly than similar non-CpG-creating mutations. To determine if this is the case in other viruses, we analyzed the allele frequencies of CpG-creating and non-CpG-creating mutations across various strains, subtypes, and genes of viruses using existing data obtained from Genbank, HIV Databases, and Virus Pathogen Resource. Our results suggest that CpG sites are indeed costly for most viruses. By understanding the cost of CpG sites, we can obtain further insights into the evolution and adaptation of viruses

Geographic mobility in the emergency medicine residency match and the influence of gender

ObjectivesWomen are underrepresented in emergency medicine (EM) leadership. Some evidence suggests that geographic mobility improves career advancement. We compared movement between medical school and residency by gender. Our hypothesis was that women move a shorter distance than men.MethodsWe collected National Residency Matching Program (NRMP) lists of ranked applicants from eight EM residency programs from the 2020 Main Residency Match. We added the gender expressed in interviews and left the Association of American Medical Colleges (AAMC) number as the unique identifier. Applicant data for matched osteopathic and allopathic seniors in the continental United States was included. We obtained street addresses for medical schools from an AAMC database and residency program addresses from the ACGME website. We performed geospatial analysis using ArcGIS Pro and compared results by gender. NRMP approved the data use and our institutional review board granted exempt status.ResultsA total of 881 of 944 unique applicants met inclusion criteria and included 48.5% (830/1,713) of matched allopaths and 37% of all matched seniors; 48% (420) were female. There was no significant difference between genders for distance moved (p = 0.31). Women moved a mean (±SD) 619 (±698) miles (median = 341 miles, range = 0–2,679 miles); and men, a mean (±SD) 641 (±717) miles (median = 315 miles, range = 0–2,671 miles). Further analysis of applicants traveling less than 50 miles (49 women, 51 men) and by census division showed no significant frequency differences.ConclusionWomen and men travel similar distances for EM residency with the majority staying within geographic proximity to their medical school. This suggests that professional mobility at this stage is not a constraint. Our study findings are limited because we do not know which personal and professional factors inform relocation decisions. Gender is not associated with a difference in distance moved by students for residency. This finding may have implications for resident selection and career development.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/170943/1/aet210706.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/170943/2/aet210706_am.pd

Leveling the field: Development of reliable scoring rubrics for quantitative and qualitative medical education research abstracts

BackgroundResearch abstracts are submitted for presentation at scientific conferences; however, criteria for judging abstracts are variable. We sought to develop two rigorous abstract scoring rubrics for education research submissions reporting (1) quantitative data and (2) qualitative data and then to collect validity evidence to support score interpretation.MethodsWe used a modified Delphi method to achieve expert consensus for scoring rubric items to optimize content validity. Eight education research experts participated in two separate modified Delphi processes, one to generate quantitative research items and one for qualitative. Modifications were made between rounds based on item scores and expert feedback. Homogeneity of ratings in the Delphi process was calculated using Cronbach’s alpha, with increasing homogeneity considered an indication of consensus. Rubrics were piloted by scoring abstracts from 22 quantitative publications from AEM Education and Training “Critical Appraisal of Emergency Medicine Education Research” (11 highlighted for excellent methodology and 11 that were not) and 10 qualitative publications (five highlighted for excellent methodology and five that were not). Intraclass correlation coefficient (ICC) estimates of reliability were calculated.ResultsEach rubric required three rounds of a modified Delphi process. The resulting quantitative rubric contained nine items: quality of objectives, appropriateness of methods, outcomes, data analysis, generalizability, importance to medical education, innovation, quality of writing, and strength of conclusions (Cronbach’s α for the third round = 0.922, ICC for total scores during piloting = 0.893). The resulting qualitative rubric contained seven items: quality of study aims, general methods, data collection, sampling, data analysis, writing quality, and strength of conclusions (Cronbach’s α for the third round = 0.913, ICC for the total scores during piloting = 0.788).ConclusionWe developed scoring rubrics to assess quality in quantitative and qualitative medical education research abstracts to aid in selection for presentation at scientific meetings. Our tools demonstrated high reliability.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/169291/1/aet210654.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/169291/2/aet210654_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/169291/3/aet210654-sup-0001-DataSupplementS1.pd