Tympanal ears mediate male-male competition, courtship and mating success in Bicyclus anynana butterflies.

The presence of intra-specific acoustic communication in diurnal butterflies is not well established. Here, we examined the function of the tympanal ear (Vogel's organ, VO) in the seasonally polyphenic butterfly Bicyclus anynana in the context of sexual signalling. We investigated how the VO and the flanking enlarged veins, which are suggested sound resonance chambers, scale with wing size across sexes and seasonal forms, and how disruptions to the VO alter courtship behaviour and mating outcomes. We found that males have VOs similar in size to females despite having smaller wings, and dry season (DS) male cubital and anal veins do not scale with the wing size. This suggests that the VO plays an important role in males and that cubital and anal veins in DS males may be tuned to amplify specific sound frequencies. Behavioural assays performed with deafened and hearing males of different seasonal forms, in pair and triad settings, showed that deafened DS males, but not wet season males, experienced lower mating success relative to their hearing counterparts. Our study documents a novel function for the wing tympanal membrane in mediating courtship and mating outcomes in diurnal butterflies.

A Comparison of Spinal Robotic Systems and Pedicle Screw Accuracy Rates: Review of Literature and Meta-Analysis.

Introduction The motivation to improve accuracy and reduce complication rates in spinal surgery has driven great advancements in robotic surgical systems, with the primary difference between the newer generation and older generation models being the presence of an optical camera and multijointed arm. This study compares accuracy and complication rates of pedicle screw placement in older versus newer generation robotic systems reported in the literature. Methods We performed a systemic review and meta-analysis describing outcomes of pedicle screw placement with robotic spine surgery. We assessed the robustness of these findings by quantifying levels of cross-study heterogeneity and publication bias. Finally, we performed meta-regression to test for associations between pedicle screw accuracy and older versus newer generation robotic spine system usage. Results Average pedicle screw placement accuracy rates for old and new generation robotic platforms were 97 and 99%, respectively. Use of new generation robots was significantly associated with improved pedicle screw placement accuracy ( p = 0.03). Conclusion Accuracy of pedicle screw placement was high across all generations of robotic surgical systems. However, newer generation robots were shown to be significantly associated with accurate pedicle screw placement, showing the benefits of upgrading robotic systems with a real-time optical camera and multijointed arm.

Ultra-broadband mid-infrared generation in dispersion-engineered thin-film lithium niobate.

Thin-film lithium niobate (TFLN) is an emerging platform for compact, low-power nonlinear-optical devices, and has been used extensively for near-infrared frequency conversion. Recent work has extended these devices to mid-infrared wavelengths, where broadly tunable sources may be used for chemical sensing. To this end, we demonstrate efficient and broadband difference frequency generation between a fixed 1-µm pump and a tunable telecom source in uniformly-poled TFLN-on-sapphire by harnessing the dispersion-engineering available in tightly-confining waveguides. We show a simultaneous 1-2 order-of-magnitude improvement in conversion efficiency and ∼5-fold enhancement of operating bandwidth for mid-infrared generation when compared to equal-length conventional lithium niobate waveguides. We also examine the effects of mid-infrared loss from surface-adsorbed water on the performance of these devices.

Supraorbital Keyhole Craniotomy for Clipping Cerebral Aneurysms: A Systematic Review and Meta-Analysis.

BACKGROUND: Open cerebrovascular surgery remains an irreplaceable tool in the neurosurgeon's armamentarium for cerebral aneurysms. Among open approaches, the supraorbital keyhole approach provides a novel approach with less soft tissue dissection and cortical exposure compared with the traditional pterional approach. OBJECTIVE: To perform a descriptive synthesis of the literature on cerebral aneurysms approached surgically via the supraorbital keyhole approach. METHODS: Following PRISMA guidelines, we performed a systematic literature review of PubMed, Scopus, and Web of Science. Patient demographic data, aneurysm characteristics, Hunt and Hess score, clipping rate, operative time, postoperative neurologic status, length of stay, and follow-up were extracted. We then performed a meta-analysis to obtain pooled estimates of these metrics across studies, including assessments for cross-study heterogeneity and publication bias. RESULTS: Under a random-effects estimate, mean intraoperative rupture rate was 6.0%. Clipping rate was 99% under a pooled fixed estimate. Significant publication bias was found within studies for aneurysm clipping rate. Forest plot analysis showed an average clinical outcome of 93% of a modified Rankin Scale score from 0 to 2 or Glasgow Outcome Scale score of IV or V at postoperative follow-up. CONCLUSIONS: Aneurysm treatment is highly heterogeneous within the literature. The supraorbital keyhole approach is an effective strategy for aneurysm treatment.

Superior Semicircular Canal Dehiscence Revision Surgery Outcomes: A Single Institution's Experience.

BACKGROUND: Superior semicircular canal dehiscence (SSCD) is an abnormality of the otic capsule, which normally overlies the superior semicircular canal. Surgical management is indicated in patients with persistent and debilitating symptoms. Given the complexity of the disease, there are patients who experience less favorable surgical outcomes and require revision surgery. The purpose of this study was to report to the rate of postoperative symptomatic improvement in patients who required revision surgery. METHODS: A retrospective analysis of patients undergoing SSCD surgical repair at a single institution was performed. Information on patient demographics, primary and secondary surgical approaches, surgical outcomes, and follow-up length was collected. RESULTS: Seventeen patients underwent 20 revision surgeries. There were eleven (65%) females and six (35%) males. Mean age of the cohorts was 50 years (range 30-68 years), and mean follow-up length was 6.8 months (range 0.1-31.1 months). Cerebrospinal fluid leak was noted in 67% of cases. The greatest postoperative symptomatic resolution was reported in oscillopsia (100%), headache (100%), and internal sound amplification (71%), while the least postoperative symptomatic resolution was reported in tinnitus (42%), aural fullness (40%), and dizziness (29%). CONCLUSIONS: Revision surgery can provide symptomatic improvement in select SSCD patients; however, patients should be cautioned about the possibility of less favorable outcomes than in index surgery. Revision surgeries are associated with a considerably higher rate of perioperative cerebrospinal fluid leak.

Relationship Between Superior Semicircular Canal Dehiscence Volume with Clinical Symptoms: Case Series.

BACKGROUND: Superior semicircular canal dehiscence (SSCD) is an osseous defect of the arcuate eminence of the petrosal temporal bone. Patients typically present with auditory and vestibular symptoms, such as hearing loss and disequilibrium. Using advanced imaging segmentation techniques, we evaluated whether the volume of SSCD correlated with preoperative symptoms and postoperative outcomes. METHODS: Our laboratory previously described a novel method of quantifying the size of an SSCD via manual segmentation. High-resolution computed tomography images of the temporal bones were imported into a specialized segmentation software. The volume of the dehiscence was outlined on consecutive slices of the coronal and axial planes via a single-pixel-thick paintbrush tool and was then calculated according to the number of nonzero image voxels. RESULTS: This study included 111 patients (70 women and 41 men; mean age, 55.1 years; age range, 24-87 years) with a total of 164 SSCDs. Mean postoperative follow-up time was 5.2 months (range, 0.03-59.5 months). The most common preoperative and postoperative symptoms were tinnitus (n = 85) and dizziness (n = 45), respectively. Surgery resulted in improvement of symptoms in most patients. The average volume of 164 SSCDs was 1.3 mm3. SSCD volume was not significantly associated with either preoperative symptoms or postoperative outcomes. CONCLUSIONS: Advances in imaging techniques have allowed increased visualization of SSCD. Further research will be necessary to evaluate the potential correlation of volume of the dehiscence with clinical variables.

Systematic Review of Serum Biomarkers in Traumatic Brain Injury.

Traumatic brain injury (TBI) is responsible for the majority of trauma-related deaths and is a leading cause of disability. It is characterized by an inflammatory process involved in the progression of secondary brain injury. TBI is measured by the Glasgow Coma Scale (GCS) with scores ranging from 15-3, demonstrating mild to severe brain injury. Apart from this clinical assessment of TBI, compendiums of literature have been published on TBI-related serum markers.Herein we create a comprehensive appraisal of the most prominent serum biomarkers used in the assessment and care of TBI.The PubMed, Scopus, Cochrane, and Web of Science databases were queried with the terms "biomarker" and "traumatic brain injury" as search terms with only full-text, English articles within the past 10 years selected. Non-human studies were excluded, and only adult patients fell within the purview of this analysis. A total of 528 articles were analyzed in the initial search with 289 selected for screening. A further 152 were excluded for primary screening. Of the remaining 137, 54 were included in the final analysis. Serum biomarkers were listed into the following broad categories for ease of discussion: immune markers and markers of inflammation, hormones as biomarkers, coagulation and vasculature, genetic polymorphisms, antioxidants and oxidative stress, apoptosis and degradation pathways, and protein markers. Glial fibrillary acidic protein(GFAP), S100, and neurons specific enolase (NSE) were the most prominent and frequently cited markers. Amongst these three, no single serum biomarker demonstrated neither superior sensitivity nor specificity compared to the other two, therefore noninvasive panels should incorporate these three serum biomarkers to retain sensitivity and maximize specificity for TBI.

Adjuvant radiotherapy for atypical meningiomas is associated with improved progression free survival.

PURPOSE: To assess the progression-free survival benefits of adjuvant radiotherapy (ART) following surgical resection compared to surgery alone in high-grade meningioma patients. METHODS: We retrospectively identified 43 patients with atypical meningiomas, who underwent either radiotherapy post-surgical resection (Surgery+ART) or surgery alone (Surgery alone) at our institution between February 2007 to March 2019. GTR was achieved in 28 patients, and STR, in 11. Patient, meningioma, and treatment data were extracted from records and compared using Kaplan-Meier methodology, log-rank tests, and Cox proportional hazard models. Radiation complications were also evaluated. RESULTS: Overall 32.6% (n = 14) of patients, 6 patients in the Surgery+ART group and 8 in the Surgery alone group, experienced recurrence. In the Surgery+ART group, the median PFS time was 46.5 months (CI: [35.8-50.6]), compared to 24.5 months (CI: [18.3-32.9]) in the Surgery alone group. 2-year PFS for Surgery+ART was 100% vs. 69.0% for Surgery alone, and the 5-year PFS rate was 70.6% and 39.2%, respectively (log-rank p-value = .004). CONCLUSIONS: Our data revealed a significant PFS increase for those treated with adjuvant radiotherapy following surgery compared to surgery alone. Future prospective studies evaluating differing radiation modalities and dosages should be conducted.

Analysis of academic publishing output among 1634 successful applicants in the 2011-2018 neurosurgery residency match.

BACKGROUND: Research productivity is a key criterion for applicant selection reported by residency program directors. Research volume reported on neurosurgery residency applications has risen steadily over the past decade. OBJECTIVE: Perform retrospective bibliographic searches of successful applicants who matched into U.S. neurosurgery residency programs from 2011 to 2018, and assess the relationship between academic publishing and residency placement. METHODS: Gender, MD/PhD status, U.S. News research ranking of medical school, and international medical graduate status (IMG) were determined for 1634 successful applicants from 2011 to 2018. Indexed publications before and after the start of residency were tabulated by Scopus®. Publication counts were stratified by first author, basic/clinical science, case reports, reviews, or other research. We then compared publishing trends across demographic variables and match cohorts. RESULTS: Average pre-residency publications increased from 2.6 [1.7, 3.4] in 2011 to 6.5 [5.1, 7.9] in 2018. Men, PhD-holders, Top 20 and Top 40 U.S. medical school graduates, and IMGs had higher pre-residency publication counts overall. After stratifying by match cohort, however, there was no significant effect of gender on pre-residency publications. Applicants matching into residency programs with highly ranked affiliated hospitals had significantly higher pre-residency publications. CONCLUSION: Publishing volume of successful neurosurgery applicants in the U.S. has risen recently and is associated with the stature of matched residency programs. Given the gap between verifiable and claimed research on residency applications, attention is needed to objectively evaluate research credentials in the selection process. The impending phase out of USMLE step 1 scores may increase emphasis on academic productivity.

Systematic review and evaluation of predictive modeling algorithms in spinal surgeries.

In order to better educate patients, predictive models have been implemented to stratify surgical risk, thereby instituting greater uniformity across surgical practices and prioritizing the safety and outcomes of patients. The purpose of this study is to conduct a systematic review summarizing the major predictive models used to evaluate patients as candidates for spinal surgery. A search was conducted for articles related to predictive modeling in spinal surgeries using PubMed, MEDLINE, and Scopus databases. Papers with area under the receiver operating curve (AUROC) scores reported were included in the analysis. Models not relevant to spinal procedures were excluded. Comparison between models was only attainable for those that reported AUROCs for individual procedures. Based on a combination of AUROC scores and demonstrated applicability to spinal procedures, the models by Scheer et al. (0.89), Ratliff et al. (0.70), the Seattle Spine Score (0.712), Risk Assessment Tool (0.67-0.7), and the Spine Sage calculator (0.81-0.85) were determined to be ideal for predictive modeling in spinal surgeries and were subsequently broken down into their individual inputs and outputs to determine what elements a theoretical model should assimilate. Alongside the model by Scheer et al., the Spine Sage calculator, Seattle Spine Score, Risk Assessment Tool, and a model by Ratliff et al. showed the most promise for patients undergoing spinal procedures. Using the first model as a springboard, new spinal predictive models can be optimized through use of larger prospective databases, with longer follow-up times, and greater inclusion of reliable high impact variables.

Engineering a Kerr-Based Deterministic Cubic Phase Gate via Gaussian Operations.

We propose a deterministic, measurement-free implementation of a cubic phase gate for continuous-variable quantum information processing. In our scheme, the applications of displacement and squeezing operations allow us to engineer the effective evolution of the quantum state propagating through an optical Kerr nonlinearity. Under appropriate conditions, we show that the input state evolves according to a cubic phase Hamiltonian, and we find that the cubic phase gate error decreases inverse quartically with the amount of quadrature squeezing, even in the presence of linear loss. We also show how our scheme can be adapted to deterministically generate a nonclassical approximate cubic phase state with high fidelity using a ratio of native nonlinearity to linear loss of only 10^{-4}, indicating that our approach may be experimentally viable in the near term even on all-optical platforms, e.g., using quantum solitons in pulsed nonlinear nanophotonics.

A systematic analysis of stereotactic radiosurgery surveys for residents in neurosurgery training programs.

OBJECT: The use of stereotactic radiosurgery (SRS) has increased. SRS training has not risen congruently. Neurosurgeons have conducted surveys and advocated implementation of widespread, standardized radiosurgery training. Here we analyze the SRS surveys conducted throughout the past decade. METHODS: This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for systematic literature review. A broad search of the literature was conducted in October 2018 through the PubMed, Scopus, Embase, and Web of Science databases. This study included surveys evaluating SRS training in neurosurgery and excluded those regarding other specialties. RESULTS: An overview of surveys showed that neurosurgery residents possess gaps in SRS knowledge and procedural competency that have persisted through the past decade. There is an overwhelming sentiment that current radiosurgery training is not adequate to prepare residents for future practice. Our recommendation is for residency programs to integrate formal SRS training electives, with a movement towards creating more options for extended SRS fellowships post-residency. CONCLUSIONS: We present data from SRS competency and current training surveys. Although resident SRS training still lags behind other subspecialties, we see indications for growth. To keep up with the role of SRS in neurosurgery, residencies need more formalized SRS rotations.

Meta-analysis of tumor control rates in patients undergoing stereotactic radiosurgery for cystic vestibular schwannomas.

OBJECTIVE: The use of SRS for treatment of cystic vestibular schwannoma is a topic of mild controversy. This review serves to introduce a renewed understanding of the efficacy of SRS as a viable treatment modality for cystic VS. PATIENTS AND METHODS: This study was conducted in accordance with the PRISMA guidelines. A broad search of the literature was conducted in October 2018 through the PubMed, Scopus, Embase, Web of Science, and Cochrane databases. Meta-analysis was conducted on tumor control rates and heterogeneity between articles was assessed using τ2, Cochran's Q, and I2 statistics. RESULTS: A total of 246 patients underwent SRS for cystic VS, with reported mean or median follow-up ranging from 49.7 to 150 months, and an overall range of 6-201 months. Following SRS treatment for cystic VS across all studies, 92% of patients had tumor control at follow up, (95%-CI: 88-95%). Tumor control rate specifically for patients who underwent GammaKnife was 93% (95-CI: 88%-95%). CONCLUSION: Despite the paucity of pertinent data, the results of our meta-analysis suggest that SRS exhibits effective tumor control rates in patients with cystic VS. Therefore, SRS can be considered a viable treatment modality when choosing amongst interventions for cystic VS.

Increased cochlear radiation dose predicts delayed hearing loss following both stereotactic radiosurgery and fractionated stereotactic radiotherapy for vestibular schwannoma.

PURPOSE: Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (fSRT) are noninvasive therapies for vestibular schwannomas providing excellent tumor control. However, delayed hearing loss after radiation therapy remains an issue. One potential target to for improving hearing rates is limiting radiation exposure to the cochlea. METHODS: We retrospectively reviewed 100 patients undergoing either SRS with 12 Gy (n = 43) or fSRT with 50 Gy over 28 fractions (n = 57) for vestibular schwannoma. Univariate and multivariate analysis were carried out to identify predictors of hearing loss as measured by the Gardner Robertson scale after radiation therapy. RESULTS: Deterioration of hearing occurred in 30% of patients with SRS and 26% with fSRT. The overall long term (> 2 year) progression rates were 20% for SRS and 16% for fSRT. Patients with a decrease in their Gardner Robertson hearing score and those that loss serviceable hearing had significantly higher average minimal doses to the cochlea in both SRS and fSRT cohorts. ROC analysis showed that a cut off of 5 Gy and 35 Gy, for SRS and fSRT respectively, predicted hearing loss with high sensitivity/specificity. CONCLUSION: Our data suggests the minimal dose of radiation that the cochlear volume is exposed to is a predictor of delayed hearing loss after either SRS or fSRT. A threshold of 5 Gy/35 Gy may lead to improved hearing preservation after radiotherapy. Further prospective multi center studies can further elucidate this mechanism.

Anxiety and contradictory class position in the hierarchy of Brazilian firefighters.

BACKGROUND: Workers holding intermediate hierarchical positions in an institution may have a higher risk of occupational stress-related, ill health. This study examined the prevalence rates and odds ratios (ORs) of anxiety disorders among a hierarchical group of firefighters. METHODS: This cross-sectional study samples firefighters from Minas Gerais, Brazil, who answered a structured questionnaire in 2011 (survey completion rate = 89.5%). The outcome of interest was a medical diagnosis of anxiety disorder. Bivariate and multivariate analyses were conducted among five hierarchical occupational positions: privates (lowest position), corporals, sergeants (intermediate position), sub lieutenants, and officers (highest position). RESULTS: Overall, 8.4% of the sample reported an anxiety disorder, with the highest rate observed among intermediate workers (sergeants = 14.2%), followed by corporals (10%), privates (5.6%), sub lieutenants (5%), and officers (2.1%). Compared with privates, the unadjusted OR for sergeants was 2.49 (95% confidence interval, 1.35, 4.58). This finding remained statistically significant after adjustment for several control variables but was eliminated by age. CONCLUSION: The mental health of firefighters is affected by social class position. Mental health promotion efforts should focus on longitudinal research and work toward interventions aimed at modifying the hierarchical structure of workplaces.

Gender equality policies, nursing professionalization, and the nursing workforce: A cross-sectional, time-series analysis of 22 countries, 2000-2015.

BACKGROUND: Nursing professionalization has substantial benefits for patients, health care systems, and the nursing workforce. Currently, however, there is limited understanding of the macro-level factors, such as policies and other country-level determinants, influencing both the professionalization process and the supply of nursing human resources. OBJECTIVES: Given the significance of gender to the development of nursing, a majority-female occupation, the purpose of this analysis was to investigate the relationship between gender regimes and gender equality policies, as macro-level determinants, and nursing professionalization indicators, in this case the regulated nurse and nurse graduate ratios. DESIGN: This cross-sectional, time-series analysis covered 16 years, from 2000 to 2015, and included 22 high-income countries, members of the Organisation for Economic Co-operation and Development. We divided countries into three clusters, using the gender policy model developed by Korpi, as proxy for gender regimes. The countries were grouped as follows: (a) Traditional family - Austria, Belgium, France, Germany, Greece, Italy, Netherlands, Portugal, and Spain; (b) Market-oriented - Australia, Canada, Ireland, Japan, New Zealand, South Korea, Switzerland, United Kingdom, and the United States; and (c) Earner-carer - Denmark, Finland, Norway, and Sweden. METHODS: We used fixed-effects linear regression models and ran Prais-Winsten regressions with panel-corrected standard errors, including a first-order autocorrelation correction to examine the effect of gender equality policies on nursing professionalization indicators. Given the existence of missing observations, we devised and implemented a multiple imputation strategy, with the help of the Amelia II program. We gathered our data from open access secondary sources. RESULTS: Both the regulated nurse and nurse graduate ratios had averages that differed across gender regimes, being the highest in Earner-carer regimes and the lowest in Traditional family ones. In addition, we identified a number of indicators of gender equality policy in education, the labour market, and politics that are predictive of the regulated nurse and nurse graduate ratios. CONCLUSION: This study's findings could add to existing upstream advocacy efforts to strengthen nursing and the nursing workforce through healthy public policy. Given that the study consists of an international comparative analysis of nursing, it should be relevant to both national and global nursing communities.

The influence of welfare state factors on nursing professionalization and nursing human resources: A time-series cross-sectional analysis, 2000-2015.

AIM: The aim of this study was to examine the relationship between welfare states and nursing professionalization indicators. DESIGN: We used a time-series, cross-sectional design. The analysis covered 16 years and 22 countries: Australia, Austria, Belgium, Canada, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Japan, Netherlands, New Zealand, Norway, Portugal, South Korea, Spain, Sweden, Switzerland, United Kingdom, and the United States, allocated to five welfare state regimes: Social Democratic, Christian Democratic, Liberal, Authoritarian Conservative, and Confucian. METHODS: We used fixed-effects linear regression models and conducted Prais-Winsten regressions with panel-corrected standard errors, including a first-order autocorrelation correction. We applied the Amelia II multiple imputation strategy to replace missing observations. Data were collected from March-December 2017 and subsequently updated from August-September 2018. RESULTS: Our findings highlight positive connections between the regulated nurse and nurse graduate ratios and welfare state measures of education, health, and family policy. In addition, both outcome variables had averages that differed among welfare state regimes, the lowest being in Authoritarian Conservative regimes. CONCLUSION: Additional country-level and international comparative research is needed to further study the impact of a wide range of structural political and economic determinants of nursing professionalization. IMPACT: We examined the effects of welfare state characteristics on nursing professionalization indicators and found support for the claim that such features affect both the regulated nurse and nurse graduate ratios. These findings could be used to strengthen nursing and the nursing workforce through healthy public policies and increase the accuracy of health human resources forecasting tools.

Superior semicircular canal dehiscence postoperative outcomes: A case series of 156 repairs.

Previous studies have looked at differences in predisposing factors, symptomology, treatment options, and outcomes in patients with SSCD experiencing audiologic and vestibular symptoms, however this study utilizes data from the largest series of SSCD patients by a single pair of neurosurgeon and head and neck surgeon to date. The objective was to determine what pre-operative factors, if any, contribute to post-operative outcomes in SSCD patients. A retrospective chart review collected patient demographics, preoperative symptoms, and postoperative symptoms. Nonparametric tests were run using IBM® SPSS® Statistics. Fisher's Exact Tests, Spearman's rho, and McNemar's test for paired comparison of binary measures were performed, with a significance level of P < 0.05. A total of 156 SSCD surgeries were performed within a cohort of 119 patients. The majority of patients were female (n = 75, 63.0%). The median age was 55 years (±12.7 years) and median follow-up length was 0.46 months (range: 0.03-59.5 months). Increased postoperative dizziness and hearing loss was significantly correlated with females (P = .048, P = .041). Additionally, males reported significantly improved postoperative hearing (P = .044) with confirmatory audiometry. Serum ionized calcium levels inversely correlated with age using spearman's coefficient (rs = -.260 P = .037). Postsurgical autophony was significantly associated with bilateral SSCD (P = .01). In conclusion, differences in outcomes between patients may have to do with bilateralism of SSCD or gender effects. Proposed theories concerning a "two hit" hypothesis and about calcium feedback regulation in SSCD may play a role in these findings. Understanding differences between symptomology will help facilitate discussions with future patients.

Local cell coordination does not alter individual cell migration during collective migration but does impact cellular exchange events.

Coordinated cell re-organization is critical to ensure correct tissue morphogenesis for a number of important embryonic and tissue repair events, however the mechanisms that govern cells coordination during collective movements, particularly in situations where cells are spatially restricted by their neighbours, are not well understood. Here we assessed cell re-organization in monolayers of retinal epithelial cells (ARPE-19) to determine if cells that coordinate with their neighbours exhibit differential migration properties to non-coordinating cells and participate differently in local cell re-organization of the tissue sheet. From global tracking analysis, we determined that the movement profiles of cells were indistinguishable regardless of whether or not they were a part of multicellular streams. Using high magnification live imaging of cell membranes, we also characterized the localized geometry and organization of a monolayer (cell area, number of nearest neighbours, aspect ratio, internal cell angles) during cell re-organization in both streaming and non-streaming regions. Consistent with our global migration analysis, we observed no differences in cell sheet geometry and organization in streaming versus non-streaming regions. We did however observe that cells executed T1-like transitions to exchange position within the space-limited monolayer and that exchange events consistently involved at least one non-streaming cell. Our data suggests a model in which cell movement within the sheet is limited by neighbour exchange events and likely cells transition between streaming and non-streaming regimes to facilitate these neighbour exchange events while maintaining the integrity of the sheet.

Sealing of superior semicircular canal dehiscence is associated with improved balance outcomes postoperatively versus plugging of the canal in middle fossa craniotomy repairs: a case series.

OBJECTIVE: The authors compared postoperative symptoms between patients with sealed and those with plugged semicircular canal dehiscence repairs. METHODS: In total, 136 ears from 118 patients who underwent surgical repair for semicircular canal dehiscence were identified via chart review. Data from postoperative MRI scans showing preservation or loss of semicircular canal fluid signal and postoperative reports of autophony, amplification, aural fullness, tinnitus, hyperacusis, hearing loss, vertigo, dizziness, disequilibrium, oscillopsia, and headache were amalgamated and analyzed. RESULTS: Patients with preservation of fluid signal were far less likely to have dizziness postoperatively (p = 0.007, OR 0.158, 95% CI 0.041-0.611). In addition, these patients were more likely to have tinnitus postoperatively (p = 0.028, OR 3.515, 95% CI 1.145-10.787). CONCLUSIONS: The authors found that superior semicircular canal dehiscence patients who undergo sealing without plugging have improved balance outcomes but show more tinnitus postoperatively than patients who undergo plugging.