Explaining negative kin discrimination in a cooperative mammal society.

Kin selection theory predicts that, where kin discrimination is possible, animals should typically act more favorably toward closer genetic relatives and direct aggression toward less closely related individuals. Contrary to this prediction, we present data from an 18-y study of wild banded mongooses, Mungos mungo, showing that females that are more closely related to dominant individuals are specifically targeted for forcible eviction from the group, often suffering severe injury, and sometimes death, as a result. This pattern cannot be explained by inbreeding avoidance or as a response to more intense local competition among kin. Instead, we use game theory to show that such negative kin discrimination can be explained by selection for unrelated targets to invest more effort in resisting eviction. Consistent with our model, negative kin discrimination is restricted to eviction attempts of older females capable of resistance; dominants exhibit no kin discrimination when attempting to evict younger females, nor do they discriminate between more closely or less closely related young when carrying out infanticidal attacks on vulnerable infants who cannot defend themselves. We suggest that in contexts where recipients of selfish acts are capable of resistance, the usual prediction of positive kin discrimination can be reversed. Kin selection theory, as an explanation for social behavior, can benefit from much greater exploration of sequential social interactions.

Masked Sentence Recognition in Children, Young Adults, and Older Adults: Age-Dependent Effects of Semantic Context and Masker Type.

OBJECTIVES: Masked speech recognition in normal-hearing listeners depends in part on masker type and semantic context of the target. Children and older adults are more susceptible to masking than young adults, particularly when the masker is speech. Semantic context has been shown to facilitate noise-masked sentence recognition in all age groups, but it is not known whether age affects a listener's ability to use context with a speech masker. The purpose of the present study was to evaluate the effect of masker type and semantic context of the target as a function of listener age. DESIGN: Listeners were children (5 to 16 years), young adults (19 to 30 years), and older adults (67 to 81 years), all with normal or near-normal hearing. Maskers were either speech-shaped noise or two-talker speech, and targets were either semantically correct (high context) sentences or semantically anomalous (low context) sentences. RESULTS: As predicted, speech reception thresholds were lower for young adults than either children or older adults. Age effects were larger for the two-talker masker than the speech-shaped noise masker, and the effect of masker type was larger in children than older adults. Performance tended to be better for targets with high than low semantic context, but this benefit depended on age group and masker type. In contrast to adults, children benefitted less from context in the two-talker speech masker than the speech-shaped noise masker. Context effects were small compared with differences across age and masker type. CONCLUSIONS: Different effects of masker type and target context are observed at different points across the lifespan. While the two-talker masker is particularly challenging for children and older adults, the speech masker may limit the use of semantic context in children but not adults.

Biased escorts: offspring sex, not relatedness explains alloparental care patterns in a cooperative breeder.

Kin selection theory predicts that animals should direct costly care where inclusive fitness gains are highest. Individuals may achieve this by directing care at closer relatives, yet evidence for such discrimination in vertebrates is equivocal. We investigated patterns of cooperative care in banded mongooses, where communal litters are raised by adult 'escorts' who form exclusive caring relationships with individual pups. We found no evidence that escorts and pups assort by parentage or relatedness. However, the time males spent escorting increased with increasing relatedness to the other group members, and to the pup they had paired with. Thus, we found no effect of relatedness in partner choice, but (in males) increasing helping effort with relatedness once partner choices had been made. Unexpectedly, the results showed clear assortment by sex, with female carers being more likely to tend to female pups, and male carers to male pups. This sex-specific assortment in helping behaviour has potential lifelong impacts on individual development and may impact the future size and composition of natal groups and dispersing cohorts. Where relatedness between helpers and recipients is already high, individuals may be better off choosing partners using other predictors of the costs and benefits of cooperation, without the need for possibly costly within-group kin discrimination.

Policing of reproduction by hidden threats in a cooperative mammal.

The evolution of cooperation in animal and human societies is associated with mechanisms to suppress individual selfishness. In insect societies, queens and workers enforce cooperation by "policing" selfish reproduction by workers. Insect policing typically takes the form of damage limitation after individuals have carried out selfish acts (such as laying eggs). In contrast, human policing is based on the use of threats that deter individuals from acting selfishly in the first place, minimizing the need for damage limitation. Policing by threat could in principle be used to enforce reproductive suppression in animal societies, but testing this idea requires an experimental approach to simulate reproductive transgression and provoke out-of-equilibrium behavior. We carried out an experiment of this kind on a wild population of cooperatively breeding banded mongooses (Mungos mungo) in Uganda. In this species, each group contains multiple female breeders that give birth to a communal litter, usually on the same day. In a 7-y experiment we used contraceptive injections to manipulate the distribution of maternity within groups, triggering hidden threats of infanticide. Our data suggest that older, socially dominant females use the threat of infanticide to deter selfish reproduction by younger females, but that females can escape the threat of infanticide by synchronizing birth to the same day as older females. Our study shows that reproduction in animal societies can be profoundly influenced by threats that remain hidden until they are triggered experimentally. Coercion may thus extend well beyond the systems in which acts of infanticide are common.

Reproductive competition triggers mass eviction in cooperative banded mongooses.

In many vertebrate societies, forced eviction of group members is an important determinant of population structure, but little is known about what triggers eviction. Three main explanations are: (i) the reproductive competition hypothesis, (ii) the coercion of cooperation hypothesis, and (iii) the adaptive forced dispersal hypothesis. The last hypothesis proposes that dominant individuals use eviction as an adaptive strategy to propagate copies of their alleles through a highly structured population. We tested these hypotheses as explanations for eviction in cooperatively breeding banded mongooses (Mungos mungo), using a 16-year dataset on life history, behaviour and relatedness. In this species, groups of females, or mixed-sex groups, are periodically evicted en masse. Our evidence suggests that reproductive competition is the main ultimate trigger for eviction for both sexes. We find little evidence that mass eviction is used to coerce helping, or as a mechanism to force dispersal of relatives into the population. Eviction of females changes the landscape of reproductive competition for remaining males, which may explain why males are evicted alongside females. Our results show that the consequences of resolving within-group conflict resonate through groups and populations to affect population structure, with important implications for social evolution.

Spontaneous spatiotemporal waves of gene expression from biological clocks in the leaf.

The circadian clocks that drive daily rhythms in animals are tightly coupled among the cells of some tissues. The coupling profoundly affects cellular rhythmicity and is central to contemporary understanding of circadian physiology and behavior. In contrast, studies of the clock in plant cells have largely ignored intercellular coupling, which is reported to be very weak or absent. We used luciferase reporter gene imaging to monitor circadian rhythms in leaves of Arabidopsis thaliana plants, achieving resolution close to the cellular level. Leaves grown without environmental cycles for up to 3 wk reproducibly showed spatiotemporal waves of gene expression consistent with intercellular coupling, using several reporter genes. Within individual leaves, different regions differed in phase by up to 17 h. A broad range of patterns was observed among leaves, rather than a common spatial distribution of circadian properties. Leaves exposed to light-dark cycles always had fully synchronized rhythms, which could desynchronize rapidly. After 4 d in constant light, some leaves were as desynchronized as leaves grown without any rhythmic input. Applying light-dark cycles to such a leaf resulted in full synchronization within 2-4 d. Thus, the rhythms of all cells were coupled to external light-dark cycles far more strongly than the cellular clocks were coupled to each other. Spontaneous desynchronization under constant conditions was limited, consistent with weak intercellular coupling among heterogeneous clocks. Both the weakness of coupling and the heterogeneity among cells are relevant to interpret molecular studies and to understand the physiological functions of the plant circadian clock.

Light and circadian regulation of clock components aids flexible responses to environmental signals.

The circadian clock measures time across a 24 h period, increasing fitness by phasing biological processes to the most appropriate time of day. The interlocking feedback loop mechanism of the clock is conserved across species; however, the number of loops varies. Mathematical and computational analyses have suggested that loop complexity affects the overall flexibility of the oscillator, including its responses to entrainment signals. We used a discriminating experimental assay, at the transition between different photoperiods, in order to test this proposal in a minimal circadian network (in Ostreococcus tauri) and a more complex network (in Arabidopsis thaliana). Transcriptional and translational reporters in O. tauri primarily tracked dawn or dusk, whereas in A. thaliana, a wider range of responses were observed, consistent with its more flexible clock. Model analysis supported the requirement for this diversity of responses among the components of the more complex network. However, these and earlier data showed that the O. tauri network retains surprising flexibility, despite its simple circuit. We found that models constructed from experimental data can show flexibility either from multiple loops and/or from multiple light inputs. Our results suggest that O. tauri has adopted the latter strategy, possibly as a consequence of genomic reduction.

Overnight In-House Critical Care Resource Intensivist Improves General Surgery Resident Education.

24/7 critical care staffing has become more commonplace, and their impact on resident training must be carefully considered. At our institution, the Critical Care Resource Intensivist (CCRI) model was implemented to provide in-house dedicated faculty responsible solely for the provision of critical care overnight. An anonymous survey was distributed to all general surgery residents to evaluate CCRI's impact on education and autonomy. Descriptive statistics were completed for quantitative data. Qualitative analysis of free text responses was completed to identify consensus themes. Responses from 26 residents demonstrated they associated CCRI with improved resident education, supervision, and patient care, without limiting autonomy. Qualitative analysis yielded 7 themes, reflecting improvements in patient care and safety, progression of care, operations and procedures, improved education, availability, and independence, but noted potential for conflict. Our findings show 24/7 dedicated intensivist staffing can enhance general surgery resident education without limiting autonomy.

Dynamic Molecular Markers of Otosclerosis in the Human Cochlea.

OBJECTIVE: To investigate the role and distribution of various molecular markers using immunohistochemistry and immunofluorescence to further elucidate and understand the pathogenesis of otosclerosis. METHODS: Archival celloidin formalin-fixed 20-micron thick histologic sections from 7 patients diagnosed with otosclerosis were studied and compared to controls. Sections in the mid-modiolar region were immunoreacted with rabbit polyclonal antibodies against nidogen-1, ß2-laminin, collagen-IX, BSP, and monoclonal antibodies against TGF ß-1 and ubiquitin. Digital images were acquired using a high-resolution light and laser confocal microscope. RESULTS: Nidogen-1, BSP, and collagen-IX were expressed in the otospongiotic regions, and to lesser extent, in the otosclerotic regions, the latter previously believed to be inactive. ß2-laminin and ubiquitin were uniformly expressed in both otospongiotic and otosclerotic regions. There was a basal level of expression of all of these markers in the normal hearing and sensorineural hearing loss specimens utilized as control. TGF ß -1, however, though present in the otosclerosis bones, was absent in the normal hearing and sensorineural hearing loss controls. CONCLUSIONS: Our results propose that the activity and function of TGF-1 may play a key role in the development and pathogenesis of otosclerosis. Further studies utilizing a higher number of temporal bone specimens will be helpful for future analysis and to help decipher its role as a potential target in therapeutic interventions.

Social norms and goal-setting interventions to promote responsible gambling in low-to-moderate online gamblers: protocol for a four-arm randomised controlled feasibility study.

INTRODUCTION: Gambling is increasingly recognised as an important public health issue. Problem gambling is associated with highly negative impacts on physical, psychological and social well-being, not only for those who gamble but also for those around them. There has been a rapid expansion of internet gambling and attributes such as continuous play and instant rewards, and enhanced privacy may lead to a greater likelihood of gambling-related harms. In this randomised controlled feasibility study, we are testing (1) the acceptability and feasibility of three online responsible gambling interventions targeting people with low-to-moderate risk of online problem gambling and (2) the feasibility of a future full-scale randomised controlled trial (RCT) to test their effectiveness and cost-effectiveness. METHODS AND ANALYSIS: Four-arm randomised controlled feasibility study with qualitative substudy. One-hundred and forty UK residents with low-to-moderate risk of online gambling recruited via gambling operators and social media will be randomised (1:1:1:1) to either (1) goal setting, (2) descriptive norms messages (challenge perceptions of peer behaviours), (3) injunctive norms messages (challenge perceptions of peer attitudes) and (4) control (delayed intervention). Interventions will be delivered over 6 weeks and individually tailored. Outcomes, administered online, will be measured at baseline, 7 weeks, and 3 and 6 months post randomisation (including gambling risk behaviours and cognitions, anxiety and depression, quality of life, health use and productivity). Analyses will be descriptive, focusing on feasibility and acceptability of the interventions and study procedures. Telephone/online interviews, with a subsample of approximately 30 participants, will elicit experiences of participating in the study. Prespecified progression criteria will guide decisions around whether to progress to a definitive RCT. ETHICS AND DISSEMINATION: Ethical approval obtained from Bournemouth University Research Ethics Committee (reference number 33247). Participants will be given a participant information sheet plus a 'Key Facts' summary and will provide informed online consent. Findings will be published in peer-reviewed journals and presented at conferences and public engagement events. TRIAL REGISTRATION NUMBER: ISRCTN37874344.

The apicobasal polarity kinase aPKC functions as a nuclear determinant and regulates cell proliferation and fate during Xenopus primary neurogenesis.

During neurogenesis in Xenopus, apicobasally polarised superficial and non-polar deep cells take up different fates: deep cells become primary neurons while superficial cells stay as progenitors. It is not known whether the proteins that affect cell polarity also affect cell fate and how membrane polarity information may be transmitted to the nucleus. Here, we examine the role of the polarity components, apically enriched aPKC and basolateral Lgl2, in primary neurogenesis. We report that a membrane-tethered form of aPKC (aPKC-CAAX) suppresses primary neurogenesis and promotes cell proliferation. Unexpectedly, both endogenous aPKC and aPKC-CAAX show some nuclear localisation. A constitutively active aPKC fused to a nuclear localisation signal has the same phenotypic effect as aPKC-CAAX in that it suppresses neurogenesis and enhances proliferation. Conversely, inhibiting endogenous aPKC with a dominant-negative form that is restricted to the nucleus enhances primary neurogenesis. These observations suggest that aPKC has a function in the nucleus that is important for cell fate specification during primary neurogenesis. In a complementary experiment, overexpressing basolateral Lgl2 causes depolarisation and internalisation of superficial cells, which form ectopic neurons when supplemented with a proneural factor. These findings suggest that both aPKC and Lgl2 affect cell fate, but that aPKC is a nuclear determinant itself that might shuttle from the membrane to the nucleus to control cell proliferation and fate; loss of epithelial cell polarity by Lgl2 overexpression changes the position of the cells and is permissive for a change in cell fate.

Validation and comparison of fall screening tools for predicting future falls among older adults.

BACKGROUND: Falls are the leading cause of injuries among older adults in the United States (US). Falls are preventable and clinicians are advised to screen for fall risk yearly. There are many falls screening tools and not all have been validated for their ability to predict future falls. METHODS: We enrolled 1905 community-dwelling older adults into a 13-month study using a probability-based representative panel of the US population recruited from NORC at the University of Chicago's National Frame. Respondents completed a baseline survey, 11 monthly fall calendars, and a final survey. The baseline survey included six falls screening tools (the Stay Independent, Three Key Questions (3KQ), a modified American Geriatric/British Geriatric tool, the short Falls Efficacy-1[FES-I]) and two single screening questions ("I have fallen in the past year" and "How many times did you fall in the past 12 months?"). The baseline and final survey collected demographic and health information, including falls. Sensitivity, specificity, positive and negative likelihood ratios, and corresponding 95% confidence intervals were calculated in SAS using weighted proportions. RESULTS: There were 1563 respondents who completed the final survey (completion rate 82%). Sensitivity estimates ranged from 22.5% for the short FES-I to 68.7% for the 3KQ. Specificity estimates ranged from 57.9% for the 3KQ to 89.4% for the short FES-I. CONCLUSIONS: Falls screening tools have varying sensitivity and specificity for predicting the occurrence of a fall in the following 12 months.

Prioritizing Flexibility, Human Connection, and Representation: Findings from the Qualitative Process Evaluation of the Special Projects of National Significance Black Men Who Have Sex with Men Initiative.

Previous research has identified significant unmet need for behavioral health care services for Black men who have sex with men (Black MSM); this challenge has been linked to poorer overall health and well-being. Health Resources and Services Administration (HRSA) funded a Special Projects of National Significance (SPNS) Initiative, Implementation of Evidence-Informed Behavioral Health Models to Improve HIV Health Outcomes for Black Men who have Sex with Men, with a goal to integrate behavioral health and clinical care services using four different evidence-informed models of care, ultimately improving HIV health outcomes. NORC at the University of Chicago conducted a multisite evaluation to assess the success of this Initiative, including a qualitative process evaluation that examined adaptations, services, integration activities, recruitment methods, and fidelity. The process evaluation described methods and processes used by demonstration sites to achieve their goals. This included challenges or barriers to implementation and the associated adaptations, notably due to the COVID-19 Public Health Emergency. Our study found key themes that indicated successful implementation were flexible service delivery, human connection, and client representation. We recommend future replicators apply these lessons learned in diverse health care and community settings that serve Black MSM. Additional information about the interventions can be found on TargetHIV.

Implementation of Evidence-Informed Behavioral Health Models to Improve HIV Health Outcomes for Black Men Who Have Sex With Men (Black MSM Initiative): Protocol for Program Evaluation.

BACKGROUND: The HIV epidemic in the United States disproportionately affects Black communities. Nearly half of Black men who have sex with men (MSM) will be diagnosed with HIV in their lifetime. There is a significant unmet need for behavioral health care services among Black MSM, and untreated behavioral health needs make it less likely the person is retained in HIV care. OBJECTIVE: This paper offers a description of the Implementation of Evidence-Informed Behavioral Health Models to Improve HIV Health Outcomes for Black Men who have Sex with Men (Black MSM) Initiative, a program to integrate clinical care and behavioral health/supportive services for Black MSM with HIV. The Black MSM Initiative is funded through the Health Resources & Services Administration HIV/AIDS Bureau Ryan White HIV/AIDS Program (RWHAP) Part F Special Projects of National Significance. METHODS: The components of the Black MSM Initiative include providing technical assistance to 8 Initiative demonstration sites; conducting a comprehensive and culturally responsive, mixed method, multisite evaluation; and disseminating evaluation findings and lessons learned to the RWHAP community. RESULTS: As of December 31, 2020, demonstration sites enrolled 809 clients in the multisite evaluation. The research team will continue evaluation data collection through December 2021 for analysis and dissemination starting in 2022. The Black MSM Initiative fully supports the US Department of Health and Human Services' Ending the HIV Epidemic in the United States Initiative. CONCLUSIONS: In order to succeed, providers and programs will need to engage populations traditionally considered "hard to reach," like many people receiving RWHAP services. Findings and lessons learned from the Black MSM Initiative will expand the tool kit of solutions to support and retain Black MSM in HIV care, furthering the goals of the Ending the HIV Epidemic Initiative and the RWHAP. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/36025.

What's in the box? Exploring UK players' experiences of loot boxes in games; the conceptualisation and parallels with gambling.

Loot boxes are a popular mechanic within many video games, but it remains unclear if some forms of loot boxes can be seen of as gambling. However, the perspectives of players are often neglected, such as whether they see them as 'fair' game elements and how closely they feel this aligns with gambling. In this paper, we synthesise a conceptualisation for loot boxes through players' actual experience and explore if there are any parallels with gambling. Twenty-one participants who played video games took part in the research through either an interview or online survey. Thematic analysis suggested that six themes were core to exploring loot boxes: Random Chance Effects, Attitudes Towards Content, Implementation, Parallels with Gambling, Game Design, and The Player. The results suggested both indirect and direct parallels with gambling from the players experiences. Implications of game design and classifying loot boxes as gambling are discussed in relation to game design and risk factors of gambling and purchasing behaviour.

Evaluating Evidence-Informed Behavioral Health Models to Improve HIV Health Outcomes: Quantitative Findings from the Ryan White HIV/AIDS Program Special Projects of National Significance Black Men Who Have Sex with Men Initiative.

The Black Men who have Sex with Men (MSM) Initiative was implemented at eight sites to engage and retain Black MSM in HIV medical care and supportive services (SS) by addressing their behavioral health (BH) care needs. Using a pre-post design and generalized logistic mixed-effects models adjusting for patient-level random effects, site, baseline age, and baseline mental health status, we evaluated whether participants experienced increased postintervention attainment of (1) Awareness of HIV medical care, BH care, and SS; (2) Screening, referral, linkage, receipt, and engagement in HIV care, BH care, and SS; and (3) Retention, antiretroviral therapy prescription, and suppressed viral load. Among 758 evaluated participants, the proportion of participants who were aware of, screened for, screened positive for, and referred to BH and SS, retention in care (72% to 79%), and viral load suppression (68% to 75%) increased between baseline and postintervention. Among participants who screened positive and received BH services were statistically more likely to be linked to [OR, 1.34 (95% CI: 1.08-1.66)] and retained in [OR, 1.36 (95% CI: 1.00-1.83)] care. Among those who screened positive and received SS were statistically more likely to be retained in care [OR, 1.54 (95% CI: 1.07-2.22)]. Measures of linkage to care declined significantly during the study period, perhaps because of COVID-19 that delayed in-person care. This study suggests that interventions designed to increase utilization of BH services and SS can be effective at improving retention in care and viral load suppression among Black MSM, at least among those currently using HIV services.

Data assimilation constrains new connections and components in a complex, eukaryotic circadian clock model.

Circadian clocks generate 24-h rhythms that are entrained by the day/night cycle. Clock circuits include several light inputs and interlocked feedback loops, with complex dynamics. Multiple biological components can contribute to each part of the circuit in higher organisms. Mechanistic models with morning, evening and central feedback loops have provided a heuristic framework for the clock in plants, but were based on transcriptional control. Here, we model observed, post-transcriptional and post-translational regulation and constrain many parameter values based on experimental data. The model's feedback circuit is revised and now includes PSEUDO-RESPONSE REGULATOR 7 (PRR7) and ZEITLUPE. The revised model matches data in varying environments and mutants, and gains robustness to parameter variation. Our results suggest that the activation of important morning-expressed genes follows their release from a night inhibitor (NI). Experiments inspired by the new model support the predicted NI function and show that the PRR5 gene contributes to the NI. The multiple PRR genes of Arabidopsis uncouple events in the late night from light-driven responses in the day, increasing the flexibility of rhythmic regulation.

Cisplatin ototoxicity histopathology.

This study investigates the histopathological changes of the cochlea and vestibular end organs of a patient who received cisplatin for Hodgkin's lymphoma. He experienced acute high-frequency sensorineural hearing loss and tinnitus after receiving treatment. Using histopathological analysis of his temporal bones after he unfortunately succumbed to his disease, we found that the ototoxic effect of cisplatin is primarily within the cochlea, with significant damage located at the organ of Corti at the base-hook region, consistent with findings in animal models. The effects of cisplatin were minimal when reviewing the vestibular end organs.

Histopathologic Analysis of Temporal Bones With Otosclerosis Following Cochlear Implantation.

OBJECTIVE: Analyze changes in osteoneogenesis and fibrosis following cochlear implant (CI) surgery in patients with otosclerosis and compare differences based on insertion technique. BACKGROUND: When advanced otosclerotic disease extends to the otic capsule, severe and profound sensorineural hearing loss necessitates consideration of a cochlear implant. Histopathological analysis of the human temporal bone after implantation in the patient with otosclerosis may reveal important variables that predict CI success. METHODS: Histopathological evaluation of archival human temporal bones from subjects with a history of CI for cochlear otosclerosis. A total of 17 human temporal bones (HTB) were analyzed, 13 implanted, and 4 contralateral non-implanted controls. RESULTS: Histopathological studies revealed extensive osteoneogenesis and fibrosis which was more prominent at the cochleostomy insertion site in the basal turn of the cochlea often obliterating the scala tympani in the basal turn, and in some cases extending to the scala media and scala vestibuli. Cochlear hydrops was nearly universal in these cases. This contrasted with the round window insertion, which exhibited minimal osteoneogenesis within the cochlear duct. In addition, in the contralateral, unimplanted control ears, there was otosclerosis at the stapes footplate, fissula ante fenestrum but no osteoneogenesis within the cochlear duct. CONCLUSION: Cochleostomy approach to CI insertion in otosclerosis patients is associated with significant fibrosis, osteoneogenesis, and cochlear hydrops. A round window insertion technique can be utilized to help minimize these histopathologic findings whenever feasible.

Cerebrospinal Fluid Leak Following Translabyrinthine Vestibular Schwannoma Surgery-Is Mesh Cranioplasty Necessary for Prevention?

OBJECTIVE: Evaluate the incidence of cerebrospinal fluid leak following vestibular schwannoma surgery for mesh cranioplasty closure versus periosteal closure in the translabyrinthine approach. Determine nonsurgical variables associated with higher rates of cerebrospinal fluid leak following vestibular schwannoma surgery. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary academic referral center. PATIENTS: One hundred thirty-two patients with adequate documentation who underwent sporadic vestibular schwannoma resection via a translabyrinthine approach between 2000 and 2019. INTERVENTION: Translabyrinthine excision of vestibular schwannoma with mesh cranioplasty closure or watertight periosteal closure. MAIN OUTCOME MEASURES: Primary outcome measures included the incidence of postoperative cerebrospinal fluid leak, total length of hospital stay (including the initial hospital stay as well as hospital days during any readmission within 30 days), and total operative time. RESULTS: Our overall cerebrospinal fluid leak rate was 9.1% with a leak rate of 12.8% in our translabyrinthine titanium mesh closure group and 0% in our translabyrinthine periosteal closure. There was no statistically significant effect of age, body mass index, or size of tumor on the incidence of cerebrospinal fluid leak. There was also no statistically significantly difference between the two groups on length of operative time or number of days spent in the intensive care unit. CONCLUSION: Mesh cranioplasty is not a prerequisite for achieving a low cerebrospinal fluid leak rate following translabyrinthine approach for vestibular schwannoma resection. In our series, a significantly lower cerebrospinal fluid leak rate was demonstrated with the periosteal closure.