Drosophila Arc1 is not required for male fertility or sperm competition success.

Activity-regulated cytoskeleton associated protein (Arc1), which is required for synaptic plasticity and metabolism in Drosophila , self-assembles into capsid-like structures that transport mRNAs in extracellular vesicles. In addition to expression in the brain and nervous system, Arc1 is expressed in the male accessory glands, an endothelial tissue that produces male seminal proteins and exosomes that impact male fertility. We thus hypothesized that Arc1 might impact male fertility. We measured the fertility, mating latency, mating duration, and sperm competition performance of Arc1 males relative to controls and found no evidence that Arc1 is required for any of these measures of male fertility.

The reporting of uveal melanoma cases to the cancer registry in North Carolina.

Objective: To ascertain the completeness of reporting of uveal melanoma cases in North Carolina to the state's cancer registry. Methods: This was a retrospective chart review performed at a single institution analyzing the completeness of information reported to the North Carolina Cancer Registry between 2010 and 2015. A list of all patients with uveal melanoma diagnosed, treated and/or followed at UNC-Chapel Hill between 2010-2015 was compared to the list of patients with uveal melanoma reported to the North Carolina Central Cancer registry during the same time frame. Results: Based on ICD 9 and 10 codes, there were 66 patients with ciliary body or choroidal melanomas diagnosed, followed and/or treated at UNC between 2010 and 2015. Of those, 41 (62%) were on the list of cases reported through the UNC Cancer Registry to the NCCCR. A chart review of the excluded cases was performed and the following barriers to reporting of uveal melanoma were identified: lack of diagnostic imaging results, lack of histopathologic confirmation, inconsistent language used to communicate diagnosis, and lack of implementation of the North American Association of Central Cancer Registries' National Interstate Data Exchange Agreement. Conclusion: The diagnosis and treatment of uveal melanoma is unique when compared to other types of cancers. Diagnosis is based on clinical features and characteristic findings on ophthalmic imaging and ultrasound. There is often no pathology report or radiologic imaging which makes it difficult for hospital registrars to recognize and confirm cases of uveal melanoma. This creates significant barriers to reporting cases to state and national cancer registries. The incomplete data makes it difficult to detect changes in the incidence of uveal melanoma in North Carolina. The development of a national uveal melanoma registry should be seriously considered.

A single mating is sufficient to induce persistent reduction of immune defense in mated female Drosophila melanogaster.

In many species, female reproductive investment comes at a cost to immunity and resistance to infection. Mated Drosophila melanogaster females are more susceptible to bacterial infection than unmated females. Transfer of the male seminal fluid protein Sex Peptide reduces female post-mating immune defense. Sex Peptide is known to cause both short- and long-term changes to female physiology and behavior. While previous studies showed that females were less resistant to bacterial infection as soon as 2.5 h and as long as 26.5 h after mating, it is unknown whether this is a binary switch from mated to unmated state or whether females can recover to unmated levels of immunity. It is additionally unknown whether repeated mating causes progressive reduction in defense capacity. We compared the immune defense of mated females when infected at 2, 4, 7, or 10 days after mating to that of unmated females and saw no recovery of immune capacity regardless of the length of time between mating and infection. Because D. melanogaster females can mate multiply, we additionally tested whether a second mating, and therefore a second transfer of seminal fluids, caused deeper reduction in immune performance. We found that females mated either once or twice before infection survived at equal proportions, both with significantly lower probability than unmated females. We conclude that a single mating event is sufficient to persistently suppress the female immune system. Interestingly, we observed that induced levels of expression of genes encoding antimicrobial peptides (AMPs) decreased with age in both experiments, partially obscuring the effects of mating. Collectively, the data indicate that being reproductively active versus reproductively inactive are alternative binary states with respect to female D. melanogaster immunity. The establishment of a suppressed immune status in reproductively active females can inform our understanding of the regulation of immune defense and the mechanisms of physiological trade-offs.

Unique structure and positive selection promote the rapid divergence of Drosophila Y chromosomes.

Y chromosomes across diverse species convergently evolve a gene-poor, heterochromatic organization enriched for duplicated genes, LTR retrotransposons, and satellite DNA. Sexual antagonism and a loss of recombination play major roles in the degeneration of young Y chromosomes. However, the processes shaping the evolution of mature, already degenerated Y chromosomes are less well-understood. Because Y chromosomes evolve rapidly, comparisons between closely related species are particularly useful. We generated de novo long-read assemblies complemented with cytological validation to reveal Y chromosome organization in three closely related species of the Drosophila simulans complex, which diverged only 250,000 years ago and share >98% sequence identity. We find these Y chromosomes are divergent in their organization and repetitive DNA composition and discover new Y-linked gene families whose evolution is driven by both positive selection and gene conversion. These Y chromosomes are also enriched for large deletions, suggesting that the repair of double-strand breaks on Y chromosomes may be biased toward microhomology-mediated end joining over canonical non-homologous end-joining. We propose that this repair mechanism contributes to the convergent evolution of Y chromosome organization across organisms.

Gene flow mediates the role of sex chromosome meiotic drive during complex speciation.

During speciation, sex chromosomes often accumulate interspecific genetic incompatibilities faster than the rest of the genome. The drive theory posits that sex chromosomes are susceptible to recurrent bouts of meiotic drive and suppression, causing the evolutionary build-up of divergent cryptic sex-linked drive systems and, incidentally, genetic incompatibilities. To assess the role of drive during speciation, we combine high-resolution genetic mapping of X-linked hybrid male sterility with population genomics analyses of divergence and recent gene flow between the fruitfly species, Drosophila mauritiana and D. simulans. Our findings reveal a high density of genetic incompatibilities and a corresponding dearth of gene flow on the X chromosome. Surprisingly, we find that a known drive element recently migrated between species and, rather than contributing to interspecific divergence, caused a strong reduction in local sequence divergence, undermining the evolution of hybrid sterility. Gene flow can therefore mediate the effects of selfish genetic elements during speciation.

Innovative Teaching for Undergraduate Nursing Students Through Mastery Modeling.

Mastery modeling was implemented to support the transfer of classroom diabetes content to the clinical area. Interactive teaching methodologies that exemplified mastery modeling included scripted classroom video and vignettes, simulation-based learning experiences, and a worksheet relating to diabetes-specific groups to use in the clinical setting. When mastery modeling teaching methodologies were implemented, transfer of knowledge through clinical reasoning was noted at a higher level for the diabetes-specific groups over the standard groups.

Cortisol and PTSD symptoms among male and female high-exposure 9/11 survivors.

Only a few studies have examined cortisol response to trauma-related stressors in relation to posttraumatic stress disorder (PTSD). We followed a sample of high-exposure survivors of the attacks on September 11, 2001 (9/11; 32 men and 29 women) and examined their cortisol response after recalling the escape from the attack, 7 and 18 months post-9/11. PTSD symptoms and saliva cortisol levels were assessed before and after trauma recollection. Hierarchical regression analyses revealed that PTSD symptoms and male sex predicted increased cortisol response following recollections. For men, elevated cortisol was associated with greater severity of reexperiencing symptoms (p < .001) and lower severity of avoidance symptoms (p < .001). For women, recall-induced cortisol was minimal and unrelated to PTSD symptoms (p = .164 and p = .331, respectively). These findings suggest that augmented cortisol response to trauma-related stressors may be evident in men reporting symptoms of PTSD. Thus, as cortisol abnormalities related to PTSD symptoms appear sex-specific, future research on mechanisms of sex differences in response to trauma is warranted.

Integrating incident data from five reporting systems to assess patient safety: making sense of the elephant.

BACKGROUND: A study was conducted to examine and compare information gleaned from five different reporting systems within one institution: incident reporting, patient complaints, risk management, medical malpractice claims, and executive walk rounds. These data sources vary in the timing of the reporting (retrospective or prospective), severity of the events, and profession of the reporters. METHODS: A common methodology was developed for classifying incidents. Data specific to each incident were abstracted from each system and then categorized using the same framework into one of 23 categories. RESULTS: Overall, there was little overlap, although each reporting system identified important safety issues. Communication problems were common among patient complaints and malpractice claims; malpractice claims' leading category was clinical judgement. Walk rounds identified issues with equipment and supplies. Adverse event reporting systems highlighted identification issues, especially mislabelled specimens. The frequency of contributions of reports by provider group varied substantially by system. Physicians accounted for 50% of risk management reports, but in adverse event reporting, where nurses were the main reporters, physicians accounted for only 2.5% of reports. Complaints and malpractice claims come primarily from patients. CONCLUSIONS: The five reporting systems each identified different yet complementary patient safety issues. To obtain a comprehensive picture of their patient safety problems and to develop priorities for improving safety, hospitals should use a broad portfolio of approaches and then synthesize the messages from all individual approaches into a collated and cohesive whole.