Risk of Bleeding Versus Venous Thromboembolism After Surgery for Breast Cancer: A National Surgical Quality Improvement Program Analysis.

INTRODUCTION: Patients who undergo surgery for breast cancer are at risk for venous thromboembolism (VTE) and bleeding, which can lead to significant consequences on outcomes. This study examined factors related to VTE and bleeding risk in breast cancer surgery, with and without reconstruction. We also investigated the relationship between operative time and resident involvement on bleeding and VTE risk. METHODS: Using the ACS-NSQIP database, patients who underwent mastectomy, implant, pedicled, or free flap reconstruction from 2005 to 2021 were identified. Resident involvement was available from 2007 to 2010. We fitted two logistic regressions to model the log odds of bleeding occurrence and VTE as linear functions of procedure type, controlling for age, body mass index, and comorbidities. RESULTS: Implant reconstruction had significantly reduced 30-d incidence of bleeding, compared to those who underwent transverse rectus abdominus muscle flap (P < 0.001). Free flap was associated with a significant increase in bleeding but not VTE risk (P < 0.001; P = 0.132). Increase in operative time significantly increased the risk of bleeding and VTE (P < 0.001). For surgeries with resident involvement coded, there was no significantly increased risk of bleeding or VTE (P = 0.600; P = 0.766). CONCLUSIONS: Implant reconstruction remains the procedure with the lowest risk of both bleeding and VTE. Free flap reconstruction did not show a significantly increased risk of VTE, potentially expanding reconstruction options for patients previously excluded from autologous reconstruction. Surgeons should be mindful of operative time, with re-evaluation of risk factors with each additional hour of surgery, irrespective of reconstruction type. Resident involvement in surgeries should continue to be encouraged by faculty.

Reducing Commercial Tobacco Sales to Youth On and Around California Tribal Reservations with a Reward and Reminder Retail Intervention.

INTRODUCTION: High prevalence of commercial tobacco product (CTP) use among American Indian and Alaska Native (AI/AN) youth is a public health crisis. A multi-level Tribal-community-based participatory research project under Tribal public health authority implemented a retailer-focused intervention to reduce AI/AN youth CTP use. METHODS: We sought resolutions in support of a retailer-focused CTP intervention from Tribal Nations organized by a tribally-directed research program. We identified tobacco retail outlets operating on and within 5 miles of 9 Tribal reservations, and CTP products sold at these outlets. We conducted a four-wave Reward and Reminder intervention with apparent minor buyers. Clerks who complied with the law received a modest reward and commendation in social media posts to the local Tribal communities, while clerks who sold without age verification were reminded of the laws. RESULTS: Of 18 retail outlets selling CTP, 8 sold e-cigarettes, and all sold combustible cigarettes. The Reward and Reminder intervention showed an approximate 25% reduction in sales of CTP to apparent minors, with a 33% baseline CTP sales rate without age verification and an 8% intervention CTP sales rate without age verification. CONCLUSIONS: The intervention increased awareness of laws prohibiting CTP sales to minors and mandating age verification for young adults seeking to buy CTP. The intervention, which had support from all governing Tribal Nations, builds the evidence base of effective practices which Tribal public health authorities may utilize to reduce youth access to CTP on and around Tribal reservations. IMPLICATIONS: Sovereign Tribes have authority over commercial businesses operating on their lands. Tobacco 21 laws aiming to restrict commercial tobacco availability to youth are supported by Tribes. A retailer intervention in which apparent minors attempt commercial tobacco purchases can offer accountability feedback to retailers both on and near Tribal reservations. Obtaining Tribal support and publicizing the interventions helps mobilize Tribal communities to support commercial tobacco prevention and promote healthy youth.

Trends in minimally invasive and open inguinal hernia repair: an analysis of ACGME general surgery case logs.

BACKGROUND: Groin hernia repair is one of the most commonly performed surgical procedures and is often performed by surgical interns and junior residents. While traditionally performed open, minimally invasive (MIS) groin hernia repair has become an increasingly popular approach. The purpose of this study was to determine the trends in MIS and open inguinal and femoral hernia repair in general surgery residency training over the past two decades. METHODS: Accreditation Council for Graduate Medical Education (ACGME) national case log data of general surgery residents from 1999 through 2022 were reviewed. We collected means and standard deviations of open and MIS inguinal and femoral hernia repairs. Linear regression and ANOVA were used to identify trends in the average annual number of open and MIS hernia repairs logged by residents. Cases were distinguished between level of resident trainees: surgeon-chief (SC) and surgeon-junior (SJ). RESULTS: From July 1999 to June 2022, the average annual MIS inguinal and femoral hernia repairs logged by general surgery residents significantly increased, from 7.6 to 47.9 cases (p < 0.001), and the average annual open inguinal and femoral hernia repairs logged by general surgery residents significantly decreased, from 51.9 to 39.7 cases (p < 0.001). SJ resident results were consistent with this overall trend. For SC residents, the volume of both MIS and open hernia repairs significantly increased (p < 0.001). CONCLUSIONS: ACGME case log data indicates a trend of general surgery residents logging overall fewer numbers of open inguinal and femoral hernia repairs, and a larger proportion of open repairs by chief residents. This trend warrants attention and further study as it may represent a skill or knowledge gap with significant impact of surgical training.

Incorporating Intersectionality as a Framework for Equity-Minded Tobacco Control Research: A Call for Collective Action Toward a Paradigm Shift.

INTRODUCTION: To eliminate tobacco-related disparities, tobacco control research would benefit from a paradigm shift. Intersectionality, a framework pioneered by Kimberlé Crenshaw in late 1980s, has the potential to improve our understanding of why and how certain social groups are disproportionately harmed by commercial tobacco use, and improve our ability to address persistent tobacco-related health disparities. AIMS AND METHODS: In this commentary, we outline the rationale and recommendations for incorporating intersectionality into equity-minded tobacco control research. These recommendations arose from intersectionality webinars organized by the Health Disparities (now Health Equity) Network of the Society for Research on Nicotine & Tobacco (SRNT) in 2019 and 2020. RESULTS: Specifically, we propose that eliminating tobacco-related disparities through intersectionality-informed research requires a multilevel, multipronged approach. We summarize priority actions for the tobacco control research field to achieve health equity through the intersectionality framework including acknowledging that structural factors, racism and power dynamics shape lived experiences, integrating critical theoretical frameworks and intersectionality scholarship into research questions, and embracing collaborative community-based approaches at every level of the research process. CONCLUSIONS: Through these actions, our field can take concrete steps to fundamentally improve our approach to conducting research to achieve health equity. IMPLICATIONS: Intersectionality is a valuable tool to align our field with our pursuit of health equity. The recommendations aim to improve methods of equity-focused tobacco control, prompt ongoing dialogue on the utility of this tool, and shift paradigms in how the research process is conducted at every level among stakeholders, including researchers, journal editors and reviewers, funders, practitioners, and policy makers.

Trends in utilization of laparoscopic colectomy according to race: an analysis of the NIS database.

BACKGROUND: Laparoscopic colectomy has been associated with improved recovery and decreased complications when compared to an open approach. Consequently, the rates of laparoscopic colectomy have increased. Race has been identified as a factor that influences a patient's likelihood of undergoing laparoscopic colectomy. Therefore, the purpose of this study is to analyze the rates of laparoscopic colectomy stratified by race over time. METHODS: Patients were selected using procedure codes for colectomy within the National Inpatient Sample (NIS) database from 2009 to 2018. The primary independent variable was race (Black, BL; Hispanic, HI; White, WH), and the primary outcome was surgical approach (laparoscopic vs open). Covariates included age, sex, case complexity, insurance status, income, year of surgery, urbanicity, region, bedsize, and teaching status. We examined the univariable association of race with laparoscopic vs open colectomy with chi-square. We used multivariable logistic regression to examine the association of race with procedure type adjusting for covariates. All analyses were done using SAS (version 9.4, Cary, NC) with p < .05 considered significant. RESULTS: 267,865 patients (25,000 BL, 19,685 HI, and 223,180 WH) were identified. Laparoscopy was used in 47% of cases, and this varied significantly by race (BL 44%, HI 49%, WH 47%, p < .0001). After adjusting for covariates, Black patients had significantly lower adjusted odds of undergoing laparoscopic colectomy vs White patients (aOR 0.92, p < 0.0001). Utilization of laparoscopy was similar in Hispanic compared to White patients (aOR 1.00, p = 0.9667). Racial disparity in the adjusted odds of undergoing laparoscopic colectomy was persistent over time. CONCLUSION: Race was independently associated with the rate of laparoscopic colectomy, with Black patients less likely to receive laparoscopic surgery than White patients. This disparity persisted over a decade. Attention should be paid to increasing the rates of laparoscopic colectomy in under-represented populations in order to optimize surgical care and address racial disparities.

Ethical publishing in 'Indigenous' contexts.

Ethical publishing practices are vital to tobacco control research practice, particularly research involving Indigenous (Indigenous peoples: For the purposes of this Special Communication, we use the term Indigenous people(s) to include self-identified individuals and communities who frequently have historical continuity with precolonial/presettler societies; are strongly linked to the land on which they or their societies reside; and often maintain their own distinct language(s), belief and social-political systems, economies and sciences. The authors humbly acknowledge, respect and value that Indigenous peoples are diverse and constitute many nations, cultures and language groups. Many Indigenous peoples also exist as governments in treaty relations with settler-colonial societies, and all Indigenous peoples have inherent rights under international law. The language and terminology used should reflect the local context(s) and could include, but are not limited to, terms such as Aboriginal, Bagumani, Cherokee, First Peoples, First Nations, Inuit, Iwaidja, Kungarakan, Lakota, Maori, Mѐtis, American Indian, Navajo, Wagadagam, Wiradjuri, Yurok, etc) people. These practices can minimise, correct and address biases that tend to privilege Euro-Western perspectives. Ethical publishing practices can minimise and address harms, such as appropriation and misuse of knowledges; strengthen mechanisms of accountability to Indigenous peoples and communities; ensure that tobacco control research is beneficial and meaningful to Indigenous peoples and communities; and support Indigenous agency, sovereignty and self-determination. To ensure ethical practice in tobacco control, the research methodology and methods must incorporate tangible mechanisms to include and engage those Indigenous peoples that the research concerns, affects and impacts.Tobacco Control is currently missing an ethical research and evaluation publishing protocol to help uphold ethical practice. The supporters of this Special Communication call on Tobacco Control to adopt publication practice that explicitly upholds ethical research and evaluation practices, particularly in Indigenous contexts. We encourage researchers, editors, peer reviewers, funding bodies and those publishing in Tobacco Control to reflect on their conduct and decision-making when working, developing and undertaking research and evaluation of relevance to Indigenous peoples.Tobacco Control and other publishers, funding bodies, institutions and research teams have a fundamental role in ensuring that the right peoples are doing the right work in the right way. We call for Tobacco Control to recognise, value and support ethical principles, processes and practices that underpin high-quality, culturally safe and priority-driven research, evaluation and science that will move us to a future that is commercial tobacco and nicotine free.

Attending guidance advised: educational quality of surgical videos on YouTube.

INTRODUCTION: YouTube is the most used platform for case preparation by surgical trainees. Despite its popular use, studies have noted limitations in surgical technique, safety, and vetting of these videos. This study identified the most viewed laparoscopic cholecystectomy (LC) videos on YouTube and analyzed the ability of attendings, residents, and medical students to identify critical portions of the procedure, technique, and limitations of the videos. METHODS: An incognito search was conducted on YouTube using the term "laparoscopic cholecystectomy." Results were screened for length, publication date, and language. The top ten most viewed videos were presented to general surgery attendings, residents, and medical students at a single academic institution. Established rubrics were used for evaluation, including the Critical View of Safety (CVS) for LC, a modified Global Operative Assessment of Laparoscopic Skills (GOALS) score, a task-specific checklist, and visual analog scales for case difficulty and operator competence. Educational quality and likelihood of video recommendation for case preparation were evaluated using a Likert scale. Attending assessments were considered the gold standard. RESULTS: Six attending surgeons achieved excellent internal consistency on CVS, educational quality, and likelihood of recommendation scales, with Cronbach alpha (⍺) of 0.93, 0.92, and 0.92, respectively. ⍺ was ≥ 0.7 in all the other scales measured. Attending evaluations revealed that only one of the ten videos attained all three established CVS criteria. Four videos demonstrated none of the CVS criteria. The mean educational quality (mEQ) was 4.63 on a 10-point scale. The mean likelihood of recommendation (mLoR) for case preparation was 2.3 on a 5-point scale. Senior resident assessments (Postgraduate Year (PGY)4 + , n = 12) aligned with attending surgeons, with no statistically significant differences in CVS attainment, mEQ, and mLoR. Junior residents (PGY1-3, n = 17) and medical students (MS3-4, n = 20) exhibited significant difference with attendings in CVS attainment, mEQ, and mLoR for more than half the videos. Both groups tended to overrate videos compared to attendings. CONCLUSION: YouTube is the most popular unvetted resource used for case presentation by surgical trainees. Attending evaluations revealed that the most viewed LC videos on YouTube did not attain the CVS, and were deemed as inappropriate for case preparation, with low educational value. Senior resident video assessments closely aligned with attendings, while junior trainees were more likely to overstate video quality and value. Attending guidance and direction of trainees to high-quality, vetted resources for surgical case preparation is needed. This may also suggest a need for surgical societies with platforms for video sharing to prioritize the creation and dissemination of high-quality videos on easily accessible public platforms.

Microecological Relationships Between Area Income, Off-Premise Alcohol Outlet Density, Drinking Patterns, and Alcohol Use Disorders: The East Bay Neighborhoods Study.

BACKGROUND: Distinguishing the impacts of neighborhood income and off-premise alcohol outlet density on alcohol use has proven difficult, particularly given the conflation of these measures across neighborhood areas. We explicitly test for differential effects related to individual and area income and outlet densities on alcohol use and alcohol use disorders (AUDs) by implementing a stratified microecological sample. METHODS: The East Bay Neighborhoods Study included a survey of 984 residents of 72 microenvironments within a geographically contiguous 6-city area in California and Systematic social observations of each site. The sites included 18 areas in each of 4 strata (high/low median household income and off-premise outlet density). We assessed 4 outcomes: 28-day drinking frequency, average quantity of alcohol consumed per drinking occasion, 28-day drinking volume, and Alcohol Use Disorders Identification Test (AUDIT) score. We used zero-inflated negative binomial regression with standard errors adjusted for site clusters to relate drinking measures to individual-level age, race/ethnicity, gender, marital status, education, and income, and neighborhood indicators of site strata, physical disorder, and physical decay. An interaction term was tested representing site-level by individual-level income. RESULTS: Living in a high-income site, regardless of off-premise alcohol outlet density, was associated with more frequent drinking and higher alcohol dependence/problems. Both individual-level income and site-level income were related to greater frequencies of use, but lower income drinkers in high-income areas drank more than comparable drinkers in low-income areas. Study participants living in high-density off-premise alcohol outlet sites drank less frequently but did not differ in terms of either AUDIT scores or heavy drinking from participants living in low-density sites. CONCLUSIONS: Using a stratified microecological sampling design, we were able to directly assess statistical associations of off-premise outlet density and neighborhood median household income with patterns of drinking and AUDs. Caution should be used interpreting prior study findings linking off-premise outlet densities to drinking.

The process of curricular integration and its effects on anatomical knowledge retention.

INTRODUCTION: Integration has been recognized as an important aspect of medical education. After transitioning from a discipline-specific to a systems-based preclinical curriculum, we examined faculty perceptions of the integrated approach and also whether it would lead to better anatomy knowledge retention. METHODS: To understand faculty perspectives, we reviewed curricular materials, interviewed block directors, and observed educational sessions. We analyzed knowledge retention through a 27-question anatomy test, comparing scores from the last class of the discipline-based curriculum and the first two classes of the integrated curriculum. RESULTS: Planning integrated content involves purposeful ordering, is challenging for faculty, and requires additional resources. Evaluation of the integrated approach for anatomy content demonstrated a significant increase in knowledge retention (p = .012; 56.28% vs. 63.98% for old vs. new curriculum). CONCLUSIONS: This study helps the understanding of what is required for curricular integration. Our anatomy evaluation results corroborated the view that contextually embedded information is easier to learn and retain.

Prevention of Underage Drinking on California Indian Reservations Using Individual- and Community-Level Approaches.

OBJECTIVES: To evaluate combined individual- and community-level interventions to reduce underage drinking by American Indian/Alaska Native (AI/AN) youths on rural California Indian reservations. METHODS: Individual-level interventions included brief motivational interviewing and psychoeducation for Tribal youths. Community-level interventions included community mobilization and awareness activities, as well as restricting alcohol sales to minors. To test effects, we compared 7 waves of California Healthy Kids Survey data (2002-2015) for 9th- and 11th-grade AI/AN and non-AI/AN students in intervention area schools with California AI/AN students outside the intervention area (n = 617, n = 33 469, and n = 976, respectively). RESULTS: Pre- to postintervention mean past 30-day drinking frequency declined among current drinkers in the intervention group (8.4-6.3 days) relative to comparison groups. Similarly, heavy episodic drinking frequency among current drinkers declined in the intervention group (7.0-4.8 days) versus the comparison groups. CONCLUSIONS: This study documented significant, sustained past 30-day drinking or heavy episodic drinking frequency reductions among AI/AN 9th- and 11th-grade current drinkers in rural California Indian reservation communities exposed to multilevel interventions. Public Health Implications. Multilevel community-partnered interventions can effectively reduce underage alcohol use in this population.

Spatial Epidemiology of Alcohol- and Drug-Related Health Problems Among Northern Plains American Indians: Nebraska and South Dakota, 2007 to 2012.

BACKGROUND: Despite high abstinence rates, American Indians experience elevated rates of many alcohol and other drug problems. American Indians also predominantly reside in poor and rural areas, which may explain some observed health disparities. We investigated whether geographic areas including reservations or large American Indian populations exhibited greater incidence of alcohol- and drug-related hospitalizations. METHODS: We obtained inpatient hospitalization records for 2 Northern Plain states (Nebraska and South Dakota) for the years 2007 to 2012. We constructed zip code counts for 10 categories of hospitalization with diagnoses or injury causation commonly associated with alcohol or drug use. We related these to community sociodemographic characteristics using Bayesian Poisson space-time regression models and examined associations with and without controls for whether each zip code was located within an American Indian reservation. RESULTS: Controlling for other demographic and economic characteristics, zip codes with greater percentage of American Indians exhibited greater incidence for all 10 substance abuse-related health outcomes (9 of 10 well supported); zip code areas within American Indian reservations had greater incidence of self-inflicted injury and drug dependence and abuse, and reduced incidence of alcohol cirrhosis and prescription opioid poisoning. However, the analyses generally demonstrated no well-supported differences in incidence associated with local residence percentages of American Indian versus African American. CONCLUSIONS: In our analyses, ethnicity or heredity alone did not account for alcohol- and drug-related hospitalizations among Native populations. Aspects of social, economic, and political dimensions of Native lives must be considered in the etiology of alcohol- and drug-related problems for rural-dwelling indigenous peoples.

Ethnographic research in immigrant-specific drug abuse recovery houses.

Access to study populations is a major concern for drug use and treatment researchers. Spaces related to drug use and treatment have varying levels of researcher accessibility based on several issues, including legality, public versus private settings, and insider/outsider status. Ethnographic research methods are indispensable for gaining and maintaining access to hidden or "hard-to-reach" populations. Here, we discuss our long-term ethnographic research on drug abuse recovery houses created by and for Latino migrants and immigrants in Northern California. We take our field work experiences as a case study to examine the problem of researcher access and how ethnographic strategies can be successfully applied to address it, focusing especially on issues of entrée, building rapport, and navigating field-specific challenges related to legality, public/private settings, and insider/outsider status. We conclude that continued funding support for ethnography is essential for promoting health disparities research focused on diverse populations in recovery from substance use disorders.

Late night environments: Bar "morphing" increases risky alcohol sales in on-premise outlets.

Niche theory proposes that in areas of high alcohol availability, alcohol sales outlets will compete for patrons by diversifying their operating characteristics to provide a diversity of drinking contexts. We aimed to characterize features of outlet operations which contribute to increased risk for alcohol problems across communities. We conducted ethnographic observations in 97 on-premise outlets across 6 California cities and interviewed staff and patrons in a subsample of these. We observed outlet managers deliberately altering the environments in 17.5% of establishments. These modifications aimed to increase bar/nightclub effects, enabling venues to "morph" (i.e., alter operating conditions from restaurant to bar, or from bar to club) and display environmental characteristics associated with over-service and alcohol-related problems (e.g., more young male patrons, crowding, and dancing). Late night morphing was observed in some outlets in most cities and included outlets operating with restaurant licenses. Staff and patrons identified morphing as a strategy to increase alcohol sales in late night hours. Competition for late night customers may encourage business practices that increase the number of alcohol sales establishments operating under risky circumstances. Community alcohol policies and practices should attend to the potential expansion of risky alcohol sales niches in night time economies.

The Reliability of Naturalistic Observations of Social, Physical and Economic Environments of Bars.

Drinking in bars contributes to numerous public health problems, including violence and motor vehicle crashes. In order to formulate effective preventive interventions it is essential to identify which specific features of bar environments are related to increased risks. Unobtrusive ethnographic observations are one approach that has been used to characterize these features; however no studies have assessed reliability in a representative sample of bars. We performed brief scouting assessments in all 165 bars in six purposively selected California cities, followed by unobtrusive observations from a subsequent representative sample of 97 bars which were located in low and high bar density areas of the cities. Inter-rater reliability between two independent observers assessed individual item reliability, and principal components analyses assessed the reliability of a series of scales describing the physical, social, and economic characteristics of the bars. For the scouting assessment, items exhibited at least moderate reliability (κ or r ≥ 0.40). For the unobtrusive observations, items assessing physical and economic environments (e.g., pool table present, κ = 0.90; index beer cost, r = 0.82) had moderate to outstanding reliability (κ or r > 0.80). Items describing the social environment generally had poorer reliability, though group aspects (e.g., patron count, r = 0.78; patron circulation, r = 0.64) had better reliability than individual behaviors (e.g., derogatory speech, κ = 0.12). Scales constructed from specific sets of items exhibited modest reliability. The individual metrics and principal components we present will enable future studies seeking to disaggregate relationships between bar characteristics and public health problems.

Are Barroom and Neighborhood Characteristics Independently Related to Local-Area Assaults?

BACKGROUND: Two separate but complementary literatures examine bar-related violence: one has focused on barroom features, and the other has focused on features of neighborhoods near bars. This study unifies these 2 perspectives using a microenvironmental approach. METHODS: In a purposive sample of 65 bars in 4 California cities, we used premise assessments to characterize the physical, social, and economic environments of barrooms (e.g., patron count, average pace of drinking, and restaurant service); and a combination of systematic social observation, census, and alcohol license data to characterize the neighborhoods in which they were located (e.g., physical disorder, alcohol outlet density, and median household income). Hierarchical Poisson models then assessed relationships between these features and counts of police-reported assaults within buffer areas around bars. RESULTS: Aspects of both barroom environments (more patrons, more dancing, and louder music) and neighborhood environments (greater bar density, greater physical disorder, lower population density, and lower income) were independently related to increased incidence of assaults. CONCLUSIONS: Preventive intervention to reduce bar-area violence may be directed at both bar environments (e.g., limiting the number of patrons) and neighborhood environments (e.g., limiting outlet density).

Traction force microscopy in rapidly moving cells reveals separate roles for ROCK and MLCK in the mechanics of retraction.

Retraction is a major rate-limiting step in cell motility, particularly in slow moving cell types that form large stable adhesions. Myosin II dependent contractile forces are thought to facilitate detachment by physically pulling up the rear edge. However, retraction can occur in the absence of myosin II activity in cell types that form small labile adhesions. To investigate the role of contractile force generation in retraction, we performed traction force microscopy during the movement of fish epithelial keratocytes. By correlating changes in local traction stress at the rear with the area retracted, we identified four distinct modes of retraction. "Recoil" retractions are preceded by a rise in local traction stress, while rear edge is temporarily stuck, followed by a sharp drop in traction stress upon detachment. This retraction type was most common in cells generating high average traction stress. In "pull" type retractions local traction stress and area retracted increase concomitantly. This was the predominant type of retraction in keratocytes and was observed mostly in cells generating low average traction stress. "Continuous" type retractions occur without any detectable change in traction stress, and are seen in cells generating low average traction stress. In contrast, to many other cell types, "release" type retractions occur in keratocytes following a decrease in local traction stress. Our identification of distinct modes of retraction suggests that contractile forces may play different roles in detachment that are related to rear adhesion strength. To determine how the regulation of contractility via MLCK or Rho kinase contributes to the mechanics of detachment, inhibitors were used to block or augment these pathways. Modulation of MLCK activity led to the most rapid change in local traction stress suggesting its importance in regulating attachment strength. Surprisingly, Rho kinase was not required for detachment, but was essential for localizing retraction to the rear. We suggest that in keratocytes MLCK and Rho kinase play distinct, complementary roles in the respective temporal and spatial control of rear detachment that is essential for maintaining rapid motility.

A Critical Assessment of Bias in Survey Studies Using Location-Based Sampling to Recruit Patrons in Bars.

Location-based sampling is a method to obtain samples of people within ecological contexts relevant to specific public health outcomes. Random selection increases generalizability; however, in some circumstances (such as surveying bar patrons), recruitment conditions increase risks of sample bias. We attempted to recruit representative samples of bars and patrons in six California cities, but low response rates precluded meaningful analysis. A systematic review of 24 similar studies revealed that none addressed the key shortcomings of our study. We recommend steps to improve studies that use location-based sampling: (i) purposively sample places of interest, (ii) use recruitment strategies appropriate to the environment, and (iii) provide full information on response rates at all levels of sampling.