The Muller F element (4.2 Mb, ~80 protein-coding genes) is an unusual autosome of Drosophila melanogaster; it is mostly heterochromatic with a low recombination rate. To investigate how these properties impact the evolution of repeats and genes, we manually improved the sequence and annotated the genes on the D. erecta, D. mojavensis, and D. grimshawi F elements and euchromatic domains from the Muller D element. We find that F elements have greater transposon density (25–50%) than euchromatic reference regions (3–11%). Among the F elements, D. grimshawi has the lowest transposon density (particularly DINE-1: 2% vs. 11–27%). F element genes have larger coding spans, more coding exons, larger introns, and lower codon bias. Comparison of the Effective Number of Codons with the Codon Adaptation Index shows that, in contrast to the other species, codon bias in D. grimshawi F element genes can be attributed primarily to selection instead of mutational biases, suggesting that density and types of transposons affect the degree of local heterochromatin formation. F element genes have lower estimated DNA melting temperatures than D element genes, potentially facilitating transcription through heterochromatin. Most F element genes (~90%) have remained on that element, but the F element has smaller syntenic blocks than genome averages (3.4–3.6 vs. 8.4–8.8 genes per block), indicating greater rates of inversion despite lower rates of recombination. Overall, the F element has maintained characteristics that are distinct from other autosomes in the Drosophila lineage, illuminating the constraints imposed by a heterochromatic milieu.

No abstract

On time start of the first case of the day is an important operating room (OR) efficiency metric, in which delays can have effects throughout the day. Although previous studies have identified various causes of first case start delays, none have attempted to evaluate the effect anesthesia staffing ratios have on first case start times. We performed a single-center retrospective analysis at an academic teaching hospital. Data was collected and analyzed over a period of 4 years and on more than 8,700 cases. We examined whether staffing ratios of attending only (solo staffing ratio), attending working with 1 resident/certified registered nurse anesthetist (CRNA) (1 to 1), or attending covering 2 residents/CRNAs (1 to 2) had a significant effect on first patient in room time (FPIR) and first case on time start (FCOTS). In addition, we examined whether staffing ratios had an effect on start times in various surgical subspecialties. We performed a univariate logistic regression analysis to determine if age, anesthesia base units, American Society of Anesthesiologists Physical Status (ASA PS) classification score, and staffing ratio was associated with FPIR and FCOTS being on time. Then, we performed a multivariate logistic regression analysis to determine if staffing ratio was associated with these outcomes, utilizing age, anesthesia base units, and ASA PS class as covariates. A decreased odds for FPIR being on time were seen in general and orthopedic surgeries when staffed 1 to 1, and cardiac surgery when staffed 1 to 2, when compared to solo staffing. FCOTS showed statistically significant differences when looking at all services with solo staffing having the highest odds for FCOTS being on time. This effect was seen also when analyzing only oncologic and orthopedic surgeries. Hospitals should consider using different staffing ratios in different surgical specialties to minimize delays and maximize OR efficiency.

Despite studies suggesting that 15% of patients treated by Emergency Medical Services (EMS) can be effectively managed at alternate destinations, most patients continue to be transported to an Emergency Department (ED). As reliable triage algorithms are lacking, we studied and iterated upon a locally developed protocol to help identify EMS patients that might be appropriate to receive care in an urgent care center (UCC). Eligible patients were those that arrived by 911 EMS and were triaged with an Emergency Severity Index (ESI) of 4 (less urgent) or 5 (non­urgent) from July to August of 2014. Prehospital data was used to determine if patients met protocol selection criteria. In-hospital data such as ED disposition, use of advanced diagnostics and interventions was also gathered. Three independent, blinded physicians determined if cases were appropriate for treatment at an UCC. In this retrospective cohort analysis of 273 low acuity ED patients, 121 (44.32%) patients met protocol selection criteria with 102 (84.30%) being determined to be appropriate for urgent care. Meanwhile, out of 152 patients that did not meet selection criteria, 84 (55.26%) were felt to be treatable at an UCC while the remaining 68 (44.74%) were not. The resulting sensitivity of the alternative destination protocol was 54.8% with a specificity of 78.2%. The positive predictive value was 84.3% and negative predictive value was 44.7%. This was a promising step towards the development of a standardized triage protocol for EMS transport of low acuity patients to alternate destinations, though further study is needed.