The Confidence Density for Correlation

Inference for correlation is central in statistics. From a Bayesian viewpoint, the final most complete outcome of inference for the correlation is the posterior distribution. An explicit formula for the posterior density for the correlation for the binormal is derived. This posterior is an optimal confidence distribution and corresponds to a standard objective prior. It coincides with the fiducial introduced by R.A. Fisher in 1930 in his first paper on fiducial inference. C.R. Rao derived an explicit elegant formula for this fiducial density, but the new formula using hypergeometric functions is better suited for numerical calculations. Several examples on real data are presented for illustration. A brief review of the connections between confidence distributions and Bayesian and fiducial inference is given in an Appendix.

How Well Does Subjective Cognitive Decline Correspond to Objectively Measured Cognitive Decline? Assessment of 10–12 Year Change

Background: Although not strongly correlated with current objective cognitive ability, subjective cognitive decline (SCD) is a risk factor for Alzheimer’s disease. Most studies focus on SCD in relation to future decline rather than objective prior decline that it purportedly measures. Objective: We evaluated whether self-report of cognitive decline—as a continuous measure—corresponds to objectively-assessed episodic memory and executive function decline across the same period. Methods: 1,170 men completed the Everyday Cognition Questionnaire (ECog) at mean age 68 assessing subjective changes in cognitive ability relative to 10 years prior. A subset had mild cognitive impairment (MCI), but MCI was diagnosed without regard to subjective decline. Participants completed up to 3 objective assessments of memory and executive function (M = 56, 62, and 68 years). Informant-reported ECogs were completed for 1,045 individuals. Analyses controlled for depression and anxiety symptoms assessed at mean age 68. Results: Participant-reported ECog scores were modestly associated with objective decline for memory (β= –0.23, 95%CI [–0.37, –0.10]) and executive function (β= –0.19, 95%CI [–0.33, –0.05]) over the same time period. However, these associations were nonsignificant after excluding MCI cases. Results were similar for informant ratings. Participant-rated ECog scores were more strongly associated with concurrent depression and anxiety symptoms, (β= 0.44, 95%CI [0.36, 0.53]). Conclusion: Continuous SCD scores are correlated with prior objective cognitive changes in non-demented individuals, though this association appears driven by individuals with current MCI. However, participants’ current depression and anxiety ratings tend to be strongly associated with their SCD ratings. Thus, what primarily drives SCD ratings remains unclear.

How Do the Abdominal Muscles Change during Hypopressive Exercise?

Background and objective: Prior studies have reported an activation of abdominal muscles during hypopressive exercises in women with pelvic floor disfunction. However, no previous research analyzed the effects of hypopressive exercise on abdominal muscles in healthy populations to understand the normal biomechanics of this area. The aim of this study was to examine the thickness of abdominal muscles at rest and during hypopressive exercise in supine and standing positions with ultrasound imaging in healthy adults. Methods: A cross-sectional study was carried out in 99 healthy university students. The thickness of the abdominal muscles at rest and during hypopressive exercise was assessed with ultrasound imaging in supine and standing positions. Results: During hypopressive exercise, there was a significant increase in the muscle thickness of transversus abdominis (p < 0.001) and internal oblique (p < 0.001) in supine and standing positions. External oblique only increased its thickness significantly in the standing position (p < 0.001) and rectus abdominis did not change during the hypopressive exercise in any position (p > 0.05). In conclusion, hypopressive exercises seem to increase the thickness of the deepest and most stabilized muscles such as transversus abdominis and internal oblique. Conclusion: These findings should be considered for future interventions with hypopressive exercises in healthy subjects.

An Objective Prior from a Scoring Rule

In this paper, we introduce a novel objective prior distribution levering on the connections between information, divergence and scoring rules. In particular, we do so from the starting point of convex functions representing information in density functions. This provides a natural route to proper local scoring rules using Bregman divergence. Specifically, we determine the prior which solves setting the score function to be a constant. Although in itself this provides motivation for an objective prior, the prior also minimizes a corresponding information criterion.

Postprandial Effects of Macronutrient Composition Meals on the Metabolic Responses and Arterial Stiffness Indices of Lean and Obese Male Adults: A Protocol of pilot Study

Background & Objective: Prior studies have shown that meal composition may affect the metabolic responses and arterial stiffness indices. Due to the lack of a comprehensive study that concurrently compares metabolic responses and vascular stiffness indices after receiving three different meals in lean and obese men, this pilot study has been conducted with a three-phase parallel design, aiming to investigate the effects of meal composition on the metabolic parameters and arterial stiffness indices of lean and obese adults. Materials and Methods: This pilot, parallel clinical trial has been performed on 20 male adults aged 18-35 years who are disease-free and selected based on the inclusion and exclusion criteria at Mashhad University of Medical Sciences, Iran. The subjects have completed three interventions at a one-week interval, including high carbohydrate (70% carbohydrates, 10% protein, 20% fat), high protein (30% protein, 50% carbohydrates, 20% fat), and high fat meal (50% fat, 40% carbohydrates, 10% protein). Postprandial effects have been assessed within 360 minutes after each meal, including the energy expenditure component (resting energy expenditure, thermic effects of feeding, respiratory quotient, and substrate oxidation) and arterial stiffness indices (augmentation index and pulse wave velocity). In addition, blood sampling has been performed to measure glucose, insulin, free fatty acids, and lipid profile. Results: The study has started since September 2020 and will continue until January 2021. The assessment of the intervention outcomes will be carried out six hours after the end of the intervention. Conclusion: The differences in the postprandial responses c affect the metabolic and vascular parameters due to different meal compositions, thereby providing beneficial data for the establishment of new strategies in terms of nutritional education and metabolic/vascular improvement.

Why Young Adults Obtain a Medical Marijuana Card: Associations with Health Symptoms, Risk, and Heaviness of Use

Objective. Prior studies documenting more frequent and problematic use among young adults who have acquired medical marijuana (MM) cards have broadly compared those who use medically to those who use recreationally. Gaining a better picture of how health symptoms and problematic use vary both within those who have a MM card for specific condition domains and between those who do not have a MM card, can provide key information for medical practitioners and states interested in adopting or updating MM policies. Method. The current study categorizes young adults authorized to use MM into four mutually exclusive groups based on endorsements of qualifying conditions: (1) Physical Health only; (2) Mental Health only; (3) Sleep only; and (4) Multiple Conditions. Analysis of covariance examined differences across marijuana use, problems, mental and physical health, and sleep for MM condition categories, and for those that only use marijuana recreationally. Results. MM card holders, particularly those with physical health or multiple health conditions, reported heavier, more frequent, and more problematic and risky marijuana use compared to those using recreationally. Despite this pattern, those in different MM condition categories were generally not found to be more symptomatic in domains of functioning relevant to their respective conditions, compared to different category groups or to those using recreationally. Conclusions. Findings emphasize the importance of providers conducting a careful assessment of reasons for needing a card, along with use, to reduce potential harms while adding credibility to a medical movement with genuine promise of relief for many medical conditions.

Posterior Propriety of an Objective Prior in a 4-Level Normal Hierarchical Model

The use of hierarchical Bayesian models in statistical practice is extensive, yet it is dangerous to implement the Gibbs sampler without checking that the posterior is proper. Formal approaches to objective Bayesian analysis, such as the Jeffreys-rule approach or reference prior approach, are only implementable in simple hierarchical settings. In this paper, we consider a 4-level multivariate normal hierarchical model. We demonstrate the posterior using our recommended prior which is proper in the 4-level normal hierarchical models. A primary advantage of the recommended prior over other proposed objective priors is that it can be used at any level of a hierarchical model.

Goals and Strategies to Solve Peer Conflict: Comparison by Aggression Trajectories

Objective. Prior research identified three trajectories of adolescent aggressive behavior from Grades 6 to 12:Low, Medium Desisting, and High Desisting Aggression. This study examined whether youth in these trajectories differed in their goals and strategies to solve conflict. Method. The sample consisted of 620 randomly selected students participating in the Healthy Teens Longitudinal Study. Participants attended schools in Northeast Georgia, USA. Mean scores were plotted for the seven years, and analysis of variance was used to examine whether student endorsement of goals and strategies differed by aggression trajectories. Results. Self-reported student goals and strategies were stable over time. At Grade 6 and 12, significantly more students in the Low Aggression trajectory endorsed positive goals and strategies to resolve peer conflict, and significantly more students in the two more aggressive trajectories endorsed aggressive goals and strategies. Youth in the two more aggressive trajectories did not differ in goals or strategies. Seeking help from a teacher did not vary by aggression trajectory or grade level. Conclusion. Given the stability of goals and strategies, school should implement programs early to enhance social-cognitive factors affecting students’ behavior in peer conflict situations, and thus prevent violence and enhance a positive school climate.