On the discrete equation model for compressible multiphase fluid flows

The modeling of multi-phase flow is very challenging, given the range of scales as well as the diversity of flow regimes that one encounters in this context. We revisit the discrete equation method (DEM) for two-phase flow in the absence of heat conduction and mass transfer. We analyze the resulting probability coefficients and prove their local convexity, rigorously establishing that our version of DEM can model different flow regimes ranging from the disperse to stratified (or separated) flow. Moreover, we reformulate the underlying mesoscopic model in terms of an one-parameter family of PDEs that interpolates between different flow regimes. We also propose two sets of procedures to enforce relaxation to equilibrium. We perform several numerical tests to show the flexibility of the proposed formulation, as well as to interpret different model components. The one-parameter family of PDEs provides an unified framework for modeling mean quantities for a multiphase flow, while at the same time identifying two key parameters that model the inherent uncertainty in terms of the underlying microstructure

Mixed-frequency quantile regression with realized volatility to forecast Value-at-Risk

The use of quantile regression to calculate risk measures has been widely recognized in the financial econometrics literature. When data are observed at mixed-frequency, the standard quantile regression models are no longer adequate. In this paper, we develop a model built on a mixed-frequency quantile regression to directly estimate the Value-at-Risk. In particular, the low-frequency component incorporates information coming from variables observed at, typically, monthly or lower frequencies, while the high-frequency component can include a variety of daily variables, like realized volatility measures or market indices. We derive the conditions for the weak stationarity of the daily return process suggested while the finite sample properties are investigated in an extensive Monte Carlo exercise. The validity of the proposed model is then explored through a real data application using the most important financial indexes. We show that our model outperforms other competing specifications, using backtesting and Model Confidence Set procedures

Fertility preservation in ovarian tumours

A considerable number of patients with a cancer diagnosis are of childbearing age and have not satisfied their desire for a family. Despite ovarian cancer (OC) usually occurring in older patients, 3%–14% are diagnosed at a fertile age with the overall 5-year survival rate being 91.2% in women ≤44 years of age when it is found at 1A–B stage. In this scenario, testing the safety and the efficacy of fertility sparing strategies in OC patients is very important overall in terms of quality of life. Unfortunately, the lack of randomised trials to validate conservative approaches does not guarantee the safety of fertility preservation strategies. However, evidence-based data from descriptive series suggest that in selected cases, the preservation of the uterus and at least one part of the ovary does not lead to a high risk of relapse. This conservative surgery helps to maintain organ function, giving patients of childbearing age the possibility to preserve their fertility. We hereby analysed the main evidence from the international literature on this topic in order to highlight the selected criteria for conservative management of OC patients, including healthy BRCA mutations carriers

Lessons Learned In The Implementation Of HealtheSteps: An Evidence-Based Healthy Lifestyle Program

HealtheSteps is a pragmatic, evidence-based lifestyle prescription program aimed at reducing the rates of chronic disease, in particular, type 2 diabetes. A pro- cess evaluation was completed to assess the feasibility of the implementation of HealtheSteps in primary care and community-based settings across Canada. Key informant interviews (program providers and participants) were conducted to identify facilitators and barriers to implementation and opportunities for future program adaptation and improvement. Forty-three interviews were conducted across five regions in Canada (15 sites ranging from remote, rural, suburban, and urban). Transcripts were analyzed using a qualitative naturalistic inquiry approach with several facilitating factors identified: pragmatic program design, in-line goals with sites’ mandates, and access to ongoing support. Barriers were related to administrative challenges such as booking space, personnel changeovers, and scheduling participants. Findings from this analysis revealed insights on program delivery, design, and importance of site champions. Key lessons learned focused on two areas: infrastructure support and pro- gram implementation. The application of these learnings from the HealtheSteps program may inform the development of strategies that can optimize program adaptation and support while reducing real and perceived barriers experienced, thus increasing the success of translation of the evidence-based diabetes program to different points of care

Type of Encouragement Influences Peak Muscle Force in College-Age Women

Purpose: To investigate if the type of encouragement during a maximal voluntary isometric contraction (MVIC) had an influence on peak muscle force in strength-trained versus untrained collegiate women. Methods: Eleven strength-trained (20.4 + 1 yr) and twelve untrained (20.8 + 1 yr) women participated in three, five-second MVICs of seated knee extension. The three trials consisted of verbal only encouragement, verbal + visual encouragement, and verbal + pain avoidance encouragement. In all three trials, the participants received the same verbal encouragement. Trials were counterbalanced to minimize any possible order effects. A repeated measure ANOVA was used to analyze data. Any significant main effects were further analyzed using Tukey post hoc tests. Results: There was no interaction between training status and encouragement type for all subjects F(2,42) = 1.5474, p = 0.22). For all subjects, a main effect for encouragement type was detected (F(2,42) = 6.616, p \u3c0.05) with significant differences found in MVIC between the verbal encouragement and verbal + visual feedback (99.5±29 ft-lbs and 115.6±29 ft-lbs, p\u3c0.01). No significant differences were found between the verbal only and the addition of pain avoidance (99.5±29 ft-lbs and 109.9±26.3 ft-lbs, p=0.069) or the visual and pain avoidance trials (115.6±29 ft-lbs and 109.9±26 ft-lbs, p=0.43). Conclusion: In this study, training status did not significantly influence the response to type of encouragement. Individuals produced the most force during a MVIC with verbal and visual encouragement. The incorporation of verbal encouragement and visual feedback is an important factor in eliciting peak force in college-aged women. This may have important implications in training and rehabilitation models that incorporate resistive loading of the skeletal muscles

Defects in Mating Behavior and Tail Morphology Are the Primary Cause of Sterility in \u3cem\u3eCaenorhabditis elegans\u3c/em\u3e Males at High Temperature

Reproduction is a fundamental imperative of all forms of life. For all the advantages sexual reproduction confers, it has a deeply conserved flaw: it is temperature sensitive. As temperatures rise, fertility decreases. Across species, male fertility is particularly sensitive to elevated temperature. Previously, we have shown in the model nematode Caenorhabditis elegans that all males are fertile at 20°C, but almost all males have lost fertility at 27°C. Male fertility is dependent on the production of functional sperm, successful mating and transfer of sperm, and successful fertilization post-mating. To determine how male fertility is impacted by elevated temperature, we analyzed these aspects of male reproduction at 27°C in three wild-type strains of C. elegans: JU1171, LKC34 and N2. We found no effect of elevated temperature on the number of immature non-motile spermatids formed. There was only a weak effect of elevated temperature on sperm activation. In stark contrast, there was a strong effect of elevated temperature on male mating behavior, male tail morphology and sperm transfer such that males very rarely completed mating successfully when exposed to 27°C. Therefore, we propose a model where elevated temperature reduces male fertility as a result of the negative impacts of temperature on the somatic tissues necessary for mating. Loss of successful mating at elevated temperature overrides any effects that temperature may have on the germline or sperm cells

The Physical Activity–Related Barriers and Facilitators Perceived by Men Living in Rural Communities

Men, especially those living in rural areas, experience chronic disease at higher rates than the general population. Physical activity is a well-established protective factor against many chronic diseases; however, only a small fraction of men are meeting national guidelines for physical activity. The purpose of this study was to examine the perceived physical activity–related barriers and facilitators experienced by men living in rural areas in Canada. Participants completed a paper-and-pencil or online survey and asked to select personally relevant physical activity-related barriers and facilitators from a list of 9 and 10 choices, respectively. A total of 149 men completed the survey (50.3% between the ages of 18 and 55 years; 43.0% older than 55 years). Participants were predominantly from rural areas and smaller communities. Overall, the response options “I’m too tired,” “I don’t have enough time,” and “I think I get enough exercise as work” were the three most frequently cited barriers to regular physical activity. The response options “Personal motivation to be healthy,” “I enjoy it,” and “Support from family and/or friends” were the three most often cited facilitators to physical activity. Results are similar to those shown in other populations. Results can be used to inform the development of policies and programs that aim to increase the physical activity levels of men living in rural areas and small communities