Geometry and Topology of Two-Dimensional Dry Foams: Computer Simulation and Experimental Characterization.

Pseudo-two-dimensional (2D) foams are commonly used in foam studies as it is experimentally easier to measure the bubble size distribution and other geometric and topological properties of these foams than it is for a 3D foam. Despite the widespread use of 2D foams in both simulation and experimental studies, many important geometric and topological relationships are still not well understood. Film size, for example, is a key parameter in the stability of bubbles and the overall structure of foams. The relationship between the size distribution of the films in a foam and that of the bubbles themselves is thus a key relationship in the modeling and simulation of unstable foams. This work uses structural simulation from Surface Evolver to statistically analyze this relationship and to ultimately formulate a relationship for the film size in 2D foams that is shown to be valid across a wide range of different bubble polydispersities. These results and other topological features are then validated using digital image analysis of experimental pseudo-2D foams produced in a vertical Hele-Shaw cell, which contains a monolayer of bubbles between two plates. From both the experimental and computational results, it is shown that there is a distribution of sizes that a film can adopt and that this distribution is very strongly dependent on the sizes of the two bubbles to which the film is attached, especially the smaller one, but that it is virtually independent of the underlying polydispersity of the foam.

Empowering Women's Prenatal Communication: Does Literacy Matter?

This study was designed to evaluate the impact of an interactive computer program developed to empower prenatal communication among women with restricted literacy skills. A total of 83 women seeing 17 clinicians were randomized to a computer-based communication activation intervention (Healthy Babies Healthy Moms [HBHM]) or prenatal education (Baby Basics [BB]) prior to their prenatal visit. Visit communication was coded with the Roter Interaction Analysis System, and postvisit satisfaction was reported. Participants were on average 24 years of age and 25 weeks pregnant; 80% were African American. Two thirds scored ≤8th grade on a literacy screener. Women with literacy deficits were more verbally active, disclosed more medical and psychosocial/lifestyle information, and were rated as more dominant by coders in the HBHM group relative to their counterparts in the BB group (all ps < .05). Clinicians were less verbally dominant and more patient centered with literate HBHM relative to BB group women (p < .05); there was a similar, nonsignificant trend (p < .1) for lower literate women. Clinicians communicated less medical information and made fewer reassurance statements to lower literate women in the HBHM relative to the BB group (p < .05). There was a trend toward lower visit satisfaction for women with restricted literacy in the HBHM relative to the BB group (p < .1); no difference in satisfaction was evident for more literate women. The HBHM intervention empowered communication of all women and facilitated verbal engagement and relevant disclosure of medical and psychosocial information of women with literacy deficits. Satisfaction, however, tended to be lower for these women.

Advanced Airway Management Skill Decay: A Review of the Literature.

Anesthesia providers must be experts in advanced airway management techniques such as laryngeal mask airway and endotracheal tube insertion. However, practicing anesthesia providers may work in clinical settings where advanced airway management techniques are rarely required. Infrequent advanced airway skill performance in these clinical settings can lead to skill decay, which is the gradual loss of acquired skills through infrequent practice or extended periods of skill nonuse. This literature review synthesizes available evidence regarding advanced airway management skill decay. Themes emerging from the literature review include skill decay association with decreased endotracheal intubation success rates, a timeframe within which advanced airway management skill decay may begin to occur, and recommendations for preventing decay of advanced airway management skills. With infrequent use of advanced airway skills in clinical settings, routine practice is crucial for skill maintenance. Clinical simulation could play a role in mitigating skill decay among practicing anesthesia providers at risk for decay in advanced airway management skills resulting from skill nonpractice.

Neutron radiography of an anisotropic drainage flow.

Liquid drainage through foam is dominated by gravity, capillary, and viscous forces. The liquid is conducted by an isotropic network of Plateau borders; however, imposed stress changes the alignment of the foam's structural elements. Previous numerical simulations predicted that a vertical drainage flow will be deflected horizontally if the foam is sheared. We investigated this phenomenon by measuring the distribution of the liquid fraction within a foam formed in a flat rectangular cell. The foam was subjected to shear stress under a forced liquid supply from the top of the cell. Neutron radiographies of unchanged and sheared foam were analyzed to extract measurements of the liquid fraction. Deflections in the distribution of the drainage liquid were detected and found to be positively correlated with increasing foam shear.

Effect of Retrofit Design Modifications on the Macroturbulence of a Three-Phase Flotation Tank-Flow Characterization Using Positron Emission Particle Tracking (PEPT).

Turbulence in stirred tank flotation tanks impacts the bulk transport of particles and has an important role in particle-bubble collisions. These collisions are necessary for attachment, which is the main physicochemical mechanism enabling the separation of valuable minerals from ore in froth flotation. Modifications to the turbulence profile in a flotation tank, therefore, can result in improvements in flotation performance. This work characterized the effect of two retrofit design modifications, a stator system and a horizontal baffle, on the particle dynamics of a laboratory-scale flotation tank. The flow profiles, residence time distributions, and macroturbulent kinetic energy distributions were derived from positron emission particle tracking (PEPT) measurements of tracer particles representing valuable (hydrophobic) mineral particles in flotation. The results show that the use of both retrofit design modifications together improves recovery by increasing the rise velocity of valuable particles and decreasing turbulent kinetic energy in the quiescent zone and at the pulp-froth interface.

Health impacts of increasing alcohol prices in the European Union: a dynamic projection.

OBJECTIVE: Western Europe has high levels of alcohol consumption, with corresponding adverse health effects. Currently, a major revision of the EU excise tax regime is under discussion. We quantify the health impact of alcohol price increases across the EU. DATA AND METHOD: We use alcohol consumption data for 11 member states, covering 80% of the EU-27 population, and corresponding country-specific disease data (incidence, prevalence, and case-fatality rate of alcohol related diseases) taken from the 2010 published Dynamic Modelling for Health Impact Assessment (DYNAMO-HIA) database to dynamically project the changes in population health that might arise from changes in alcohol price. RESULTS: Increasing alcohol prices towards those of Finland (the highest in the EU) would postpone approximately 54,000 male and approximately 26,100 female deaths over 10 years. Moreover, the prevalence of a number of chronic diseases would be reduced: in men by approximately 97,800 individuals with diabetes, 65,800 with stroke and 62,200 with selected cancers, and in women by about 19,100, 23,500, and 27,100, respectively. CONCLUSION: Curbing excessive drinking throughout the EU completely would lead to substantial gains in population health. Harmonisiation of prices to the Finnish level would, for selected diseases, achieve more than 40% of those gains.

Standard method for performing positron emission particle tracking (PEPT) measurements of froth flotation at PEPT Cape Town.

Positron emission particle tracking (PEPT) is a technique for measuring the motion of tracer particles in systems of flow such as mineral froth flotation. An advantage of PEPT is that tracer particles with different physical properties can be tracked in the same experimental system, which allows detailed studies of the relative behaviour of different particle classes in flotation. This work describes the standard operating protocol developed for PEPT experiments in a flotation vessel at PEPT Cape Town in South Africa. A continuously overflowing vessel with constant air recovery enables several hours of data acquisition at steady state flow and consistent flotation conditions. Tracer particles are fabricated with different coatings to mimic mineral surface hydrophobicity and size, and a data treatment derived from a rotating disk study is utilized to produce high frequency (1 kHz) location data relative to the tracer activity. Time averaging methods are used to represent the Eulerian flow field and occupancy of the tracer behaviour based on voxel schemes in different co-ordinate systems. The average velocity of the flow in each voxel is calculated as the peak of the probability density function to represent the peak of asymmetrical or multimodal distributions.•A continuously overflowing flotation vessel was developed for extended data acquisition at steady state flow.•The data treatment enabled the direct comparison of different particle classes in the flotation vessel.•The solids flow fields was described by the probability density function of tracer particle velocity measured in different voxel schemes.

Poor Postpartum Sleep Quality Predicts Subsequent Postpartum Depressive Symptoms in a High-Risk Sample.

STUDY OBJECTIVES: Postpartum depression (PPD) occurs in 15% to 20% of mothers worldwide and is associated with adverse outcomes for mother and child. Prior research has established a relationship between concurrent sleep quality and PPD. We conducted a secondary analysis in 45 women with mood disorders to study overall sleep quality (and individual components of sleep), measured in the early postpartum period, as a predictor of subsequent PPD. METHODS: We measured sleep quality using the Pittsburgh Sleep Quality Index (PSQI; subscale and total scores) at 1 month postpartum (and during the third trimester). We measured depressive symptoms using the Inventory of Depressive Symptoms, Self-Report (IDS-SR) at 3 months postpartum. We used bivariate and multivariate linear regression models to study the association between PSQI and IDS scores. RESULTS: We found that higher global PSQI scores as well as higher component scores for self-reported sleep quality, sleep latency, sleep efficiency, sleep medication usage, and daytime dysfunction, measured 1 month postpartum, were associated with increased IDS scores (at 3 months postpartum (P = .01, .01, .01, .003, < .001, respectively). We did not find an association between poor sleep quality in the third trimester and PPD. CONCLUSIONS: Poor sleep quality in the early postpartum period independently predicts development of later PPD. This is clinically significant and highlights the importance of sleep interventions as an immediate postpartum therapeutic tool. CITATION: McEvoy KM, Rayapati D, Washington Cole KO, Erdly C, Payne JL, Osborne LM. Poor postpartum sleep quality predicts subsequent postpartum depressive symptoms in a high-risk sample. J Clin Sleep Med. 2019;15(9):1303-1310.

Neighborhood and Parental Influences on Diet and Physical Activity Behaviors in Young Low-Income Pediatric Patients.

This study explores the relationship between neighborhood characteristics and caregiver preferences for establishing diet and physical activity behaviors among low-income African American and Hispanic young children (2-5 years). Primary caregivers of young children were recruited from 2 urban pediatric clinics to participate in focus groups (n = 33). Thematic analysis of transcripts identified 3 themes: neighborhood constraints on desired behaviors, caregivers' strategies in response to neighborhoods, and caregivers' sense of agency in the face of neighborhood constraints. This study elucidates the dynamic relationship between neighborhoods and caregiver preferences, their interrelated impacts on establishment of diet and physical activity behaviors among young children, and the important role of caregiver agency in establishing behaviors among young children. To effectively address obesity disparities among young children, primary care behavioral interventions must leverage and support such resilient caregiver responses to neighborhood constraints in order to optimally address racial/ethnic and socioeconomic disparities in obesity among young children.

Providing prenatal care to pregnant women with overweight or obesity: Differences in provider communication and ratings of the patient-provider relationship by patient body weight.

OBJECTIVE: To examine the association of women's body weight with provider communication during prenatal care. METHODS: We coded audio recordings of prenatal visits between 22 providers and 117 of their patients using the Roter Interaction Analysis System. Multivariate, multilevel Poisson models were used to examine the relationship between patient pre-pregnancy body mass index and provider communication. RESULTS: Compared to women with normal weight, providers asked fewer lifestyle questions (IRR 0.66, 95% CI 0.44-0.99, p=0.04) and gave less lifestyle information (IRR 0.51, 95% CI 0.32-0.82, p=0.01) to women with overweight and obesity, respectively. Providers used fewer approval (IRR 0.68, 95% CI 0.51-0.91, p=0.01) and concern statements (IRR 0.68, 95% CI 0.53-0.86, p=0.002) when caring for women with overweight and fewer self-disclosure statements caring for women with obesity (IRR 0.40, 95% CI 0.19-0.84 p=0.02). CONCLUSION: Less lifestyle and rapport building communication for women with obesity may weaken patient-provider relationship during routine prenatal care. PRACTICE IMPLICATIONS: Interventions to increase use of patient-centered communication - especially for women with overweight and obesity - may improve prenatal care quality.

Influence of the 5A's Counseling Strategy on Weight Gain During Pregnancy: An Observational Study.

BACKGROUND: Healthy weight gain during pregnancy may improve health outcomes for women and infants. The objective of this study was to examine providers' use of the 5A's (Assess, Advise, Agree, Assist, and Arrange) in discussions of weight, nutrition, and physical activity during prenatal visits and evaluate the effect of this approach on gestational weight gain. MATERIALS AND METHODS: We studied audio recordings of prenatal visits between 22 obstetrics providers and 120 of their patients, coding visits for providers' use of the 5A's. The relationship between the 5A's and gestational weight gain (total weight gain and excess gestational weight gain) was evaluated using multilevel models to account for patient clustering within provider, and adjusted for prepregnancy body mass index, parent study intervention assignment, gestational age at the study visit, and study visit length. RESULTS: Overall, 55% of prenatal visits included any weight-related behavioral counseling. Of these, 59.1% included one of the 5A's and 40.9% included two or more of the 5A's. Counseling conversations most commonly included Assess or Advise (49% and 85% of counseling conversations, respectively). No recorded visits used all 5A's. In adjusted analyses, patients who received counseling with two or more of the 5A's gained an average of 11.8 fewer pounds than patients who received no counseling (p = 0.001). The odds of excess gestational weight gain were lower among women receiving counseling with at least one of the 5A's (p < 0.05). CONCLUSIONS: The 5A's were associated with lower gestational weight gain and may be a promising counseling strategy to promote healthy weight gain during pregnancy.

Starting the conversation: Patient initiation of weight-related behavioral counseling during pregnancy.

OBJECTIVE: To examine the relationship between patient initiation and weight-related behavioral counseling during pregnancy. METHODS: We examined audio recordings of prenatal visits between 22 obstetricians and 120 patients for behavioral counseling using the Roter Interaction Analysis System and the 5A's behavioral counseling framework. We used multivariate regression models to examine the relationship between patient initiation and communication outcomes. RESULTS: Overall, 55% of prenatal visits included any behavioral counseling. Patients initiated counseling episodes 45.5% of these visits. Patients were less verbally dominated by their clinicians in prenatal visits with patient-initiated behavioral counseling episodes (difference in clinician verbal dominance ratio=0.73, 95% CI=0.16-1.30). Patient-initiated counseling episodes included more socioemotional communication relative to those initiated by clinicians (p=0.02). The total duration of counseling was 28s longer (95% CI 0.27-56.0s) and clinicians were more likely to use two or more 5A's strategies (OR=3.61, 95% CI=1.01-12.88) when patients initiated discussions. CONCLUSIONS: Patient initiation may lead to behavioral counseling that is longer in duration and includes more 5A's strategies, possibly mediated by socioemotional communication. PRACTICE IMPLICATIONS: Participatory prenatal care communication may lead to more effective counseling that is responsive to women's concerns.

Complementary and alternative medicine for pediatric otitis media.

OBJECTIVE: To review the literature involving complementary and alternative medicine (CAM) for pediatric otitis media. Multiple modalities are discussed, including prevention involving breastfeeding, nutrition, and vaccination; symptomatic treatment involving homeopathy, natural health products, and probiotics; manual manipulations involving osteopathy and chiropractics; and traditional Chinese and Japanese medicine. The information presented will assist physicians in advising patients on their decision-making during the early stages of otitis media when antibiotics and surgery are not yet indicated. METHODS: A systematic literature search was conducted through January 2012 in PubMed using MESH term "otitis media" in conjunction with "complementary therapies," "homeopathy," "manipulation, osteopathic," "manipulation, chiropractic," "acupuncture therapy," "probiotics," "naturopathy," and "xylitol." Theses searches yielded 163 unique results. Abstracts and titles were evaluated for relevance. Case reports, case series, randomized controlled trials, and basic science research were included. Publications not relevant to the discussion of alternative medicine in otitis media were excluded. Bibliographies were checked for further publications. Thirty-six unique publications were reviewed. RESULTS: Of all therapies in complementary and alternative medicine, only xylitol has been studied in well-designed, randomized, blinded trials; it is likely effective, but compliance limits its applicability. CONCLUSIONS: Management of acute otitis media begins with watchful waiting. Herbal eardrops may help relieve symptoms. Homeopathic treatments may help decrease pain and lead to faster resolution. Prevention should be emphasized with elimination of risk factors, such as second hand smoke and bottle-feeding, as well as maintaining nutrition and vaccinations. Vitamin supplementation may be helpful. Probiotics and xylitol may be beneficial as well. Traditional Chinese/Japanese therapies show promising results but remain speculative until further research is conducted. Severe cases of otitis media with complications or those that fail to improve with observation or CAM (after 48-72h) should be treated with antibiotics and, in some cases, surgical intervention. It is best to consult a physician when making treatment decisions for full guidance on the risks and benefits of any treatment option.