Application of second-order turbulent modeling to the prediction of radiated aerodynamic sound

The Ribner formulation of the generation of aerodynamic sound is coupled with predictions of second-order velocity correlations and integral scale to estimate the sound radiated from several complicated jet flows. In particular, it is shown that the sound radiated from a cold swirling jet is greater than from its nonswirling equal thrust counterpart. The noise radiated from the flow field of a multitube suppressor was estimated and compared with an equal thrust diameter Gaussian jet. It is shown that the multitube concept is indeed quieter

An experimental investigation of the relationships among race, prayer, and pain

Background and aims Compared to White individuals, Black individuals demonstrate a lower pain tolerance. Research suggests that differences in pain coping strategies, such as prayer, may mediate this race difference. However, previous research has been cross-sectional and has not determined whether prayer in and of itself or rather the passive nature of prayer is driving the effects on pain tolerance. The aim of this study was to clarify the relationships among race, prayer (both active and passive), and pain tolerance. Methods We randomly assigned 208 pain-free participants (47% Black, 53% White) to one of three groups: active prayer (“God, help me endure the pain”), passive prayer (“God, take the pain away”), or no prayer (“The sky is blue”). Participants first completed a series of questionnaires including the Duke University Religion Index, the Coping Strategies Questionnaire-Revised (CSQ-R), and the Pain Catastrophizing Scale. Participants were then instructed to repeat a specified prayer or distractor coping statement while undergoing a cold pressor task. Cold pain tolerance was measured by the number of seconds that had elapsed while the participant’s hand remained in the cold water bath (maximum 180 s). Results Results of independent samples t-tests indicated that Black participants scored higher on the CSQ-R prayer/hoping subscale. However, there were no race differences among other coping strategies, religiosity, or catastrophizing. Results of a 2 (Race: White vs. Black)×3 (Prayer: active vs. passive vs. no prayer) ANCOVA controlling for a general tendency to pray and catastrophizing in response to prayer indicated a main effect of prayer that approached significance (p=0.06). Pairwise comparisons indicated that those in the active prayer condition demonstrated greater pain tolerance than those in the passive (p=0.06) and no prayer (p=0.03) conditions. Those in the passive and no prayer distractor conditions did not significantly differ (p=0.70). There was also a trending main effect of race [p=0.08], with White participants demonstrating greater pain tolerance than Black participants. Conclusions Taken together, these results indicate that Black participants demonstrated a lower pain tolerance than White participants, and those in the active prayer condition demonstrated greater tolerance than those in the passive and no prayer conditions. Furthermore, Black participants in the passive prayer group demonstrated the lowest pain tolerance, while White participants in the active prayer group exhibited the greatest tolerance. Results of this study suggest that passive prayer, like other passive coping strategies, may be related to lower pain tolerance and thus poorer pain outcomes, perhaps especially for Black individuals. On the other hand, results suggest active prayer is associated with greater pain tolerance, especially for White individuals. Implications These results suggest that understanding the influence of prayer on pain may require differentiation between active versus passive prayer strategies. Like other active coping strategies for pain, active prayer may facilitate self-management of pain and thus enhance pain outcomes independent of race. Psychosocial interventions may help religiously-oriented individuals, regardless of race, cultivate a more active style of prayer to improve their quality of life

Pain intensity and attribution mediate the impact of patient weight and gender on activity recommendations for chronic pain

Background and purpose: Despite the notable benefits of physical activity for chronic pain, a large proportion of patients with chronic pain report that they do not receive activity-related recommendations from their providers. Research suggests that patient factors such as weight and gender influence activity-related recommendations for chronic pain. Research also suggests that appraisals of the intensity and cause of pain may explain these weight and gender effects. We investigated the influence of patient weight and gender on observers' likelihood of recommending activity-related treatments for pain. We also explored the mediating effects of observers' ratings of pain severity and the extent to which pain was due to medical and lifestyle factors (pain attribution). Patients and methods: Healthy young adults (N=616; 76% female) viewed videos (Ghent Pain Videos of Daily Activities) and vignettes of 4 patients with chronic back pain performing a standardized functional task. Patients varied by gender (female, male) and weight (normal, obese), but were otherwise equivalent on demographic characteristics and pain behaviors. Participants rated how much pain they perceived the patients to be experiencing, the extent to which they attributed the pain to medical and lifestyle factors, and their likelihood of recommending exercise, physical therapy (PT), and rest. Results: Patient weight and gender significantly interacted to influence exercise, PT, and rest recommendations. Both pain intensity and pain attribution mediated the relationships between patient weight and activity recommendations; however, these mediation effects differed across gender and recommendation type. Conclusion: Patient weight and gender influenced laypeople's activity recommendations for chronic pain. Moreover, the results suggest that observers' perceptions of pain intensity and pain attributions are mechanisms underlying these effects. If these findings are replicated in providers, interventions may need to be developed to reduce provider biases and increase their recognition of the benefits of physical activity for chronic pain

Injustice perceptions about pain: parent–child discordance is associated with worse functional outcomes

Pain is experienced within and influenced by social environments. For children with chronic pain, the child–parent relationship and parental beliefs about pain are particularly important and may influence pain outcomes. Pain-related injustice perceptions have recently been identified as an important cognitive–emotional factor for children with pain. The current study aimed to better understand the pain-related injustice perceptions of children with chronic pain and their parents. The sample consisted of 253 pediatric chronic pain patients (mean age = 14.1 years, 74% female) presenting to a tertiary pain clinic. Patients completed measures of pain intensity, pain-related injustice perceptions, stress, functional disability, and quality of life. Parents completed a measure of pain-related injustice perceptions about their child's pain. Child–parent dyads were categorized into 1 of 4 categories based on the degree of concordance or discordance between their scores on the injustice measures. One-way analysis of variances examined differences in pain intensity, stress, functional disability, and quality of life across the 4 dyad categories. Our findings indicated that both the degree (concordant vs discordant) and direction (discordant low child–high parent vs discordant high child–low parent) of similarity between child and parent injustice perceptions were associated with child-reported pain intensity, stress, functional disability, and quality of life. The poorest outcomes were reported when children considered their pain as highly unjust, but their parents did not. These findings highlight the important role of parents in the context of pain-related injustice perceptions in pediatric chronic pain

Atmospheric-wake vortex interactions

The interactions of a vortex wake with a turbulent stratified atmosphere are investigated with the computer code WAKE. It is shown that atmospheric shear, turbulence, and stratification can provide the dominant mechanisms by which vortex wakes decay. Computations included the interaction of a vortex wake with a viscous ground plane. The observed phenomenon of vortex bounce is explained in terms of secondary vorticity produced on the ground. This vorticity is swept off the ground and advected about the vortex pair, thereby altering the classic hyperbolic trajectory. The phenomenon of the solitary vortex is explained as an interaction of a vortex with crosswind shear. Here, the vortex having the sign opposite that of the sign of the vorticity in the shear is dispersed by a convective instability. This instability results in the rapid production of turbulence which in turn disperses the smoke marking the vortex

To what extent do the Classical Equations of Motion Determine the Quantization Scheme?

A simple example of one particle moving in a (1+1) space-time is considered. As an example we take the harmonic oscillator. We confirm the statement that the classical Equations of Motion do not determine at all the quantization scheme. To this aim we use two inequivalent Lagrange functions, yielding Euler-Lagrange Equations, having the same set of solutions. We present in detail the calculations of both cases to emphasize the differences occuring between them.Comment: LaTeX 20 page

Fractional Generalization of Gradient Systems

We consider a fractional generalization of gradient systems. We use differential forms and exterior derivatives of fractional orders. Examples of fractional gradient systems are considered. We describe the stationary states of these systems.Comment: 11 pages, LaTe

Acceptance and commitment therapy for symptom interference in metastatic breast cancer patients: a pilot randomized trial

PURPOSE: Breast cancer is the leading cause of cancer mortality in women worldwide. With medical advances, metastatic breast cancer (MBC) patients often live for years with many symptoms that interfere with activities. However, there is a paucity of efficacious interventions to address symptom-related suffering and functional interference. Thus, this study examined the feasibility and preliminary efficacy of telephone-based acceptance and commitment therapy (ACT) for symptom interference with functioning in MBC patients. METHODS: Symptomatic MBC patients (N = 47) were randomly assigned to six telephone sessions of ACT or six telephone sessions of education/support. Patients completed measures of symptom interference and measures assessing the severity of pain, fatigue, sleep disturbance, depressive symptoms, and anxiety. RESULTS: The eligibility screening rate (64%) and high retention (83% at 8 weeks post-baseline) demonstrated feasibility. When examining within-group change, ACT participants showed decreases in symptom interference (i.e., fatigue interference and sleep-related impairment; Cohen's d range = - 0.23 to - 0.31) at 8 and 12 weeks post-baseline, whereas education/support participants showed minimal change in these outcomes (d range = - 0.03 to 0.07). Additionally, at 12 weeks post-baseline, ACT participants showed moderate decreases in fatigue and sleep disturbance (both ds = - 0.43), whereas education/support participants showed small decreases in these outcomes (ds = - 0.24 and - 0.18 for fatigue and sleep disturbance, respectively). Both the ACT and education/support groups showed reductions in depressive symptoms (ds = - 0.27 and - 0.28) at 12 weeks post-baseline. Group differences in all outcomes were not statistically significant. CONCLUSIONS: ACT shows feasibility and promise in improving fatigue and sleep-related outcomes in MBC patients and warrants further investigation

C-axis Optical Sum Rule in Josephson Coupled Vortex State

Observed violations of the $c$-axis optical sum rule can give important information on deviations from in-plane Fermi liquid behavior and on the nature of interlayer coupling between adjacent copper oxide planes. Application of a magnetic field perpendicular to these planes is another way to probe in-plane dynamics. We find that the optical sum rule is considerably modified in the presence of the $c$-axis magnetic field. Interlayer correlation of pancake vortices is involved in the sum rule modification; however, details of the vortex distribution in the plane are less important.Comment: one figure. To be published in PRB (Sep. 20001

Magnon-Paramagnon Effective Theory of Itinerant Ferromagnets

The present work is devoted to the derivation of an effective magnon-paramagnon theory starting from a microscopic lattice model of ferromagnetic metals. For some values of the microscopic parameters it reproduces the Heisenberg theory of localized spins. For small magnetization the effective model describes the physics of weak ferromagnets in accordance with the experimental results. It is written in a way which keeps O(3) symmetry manifest,and describes both the order and disordered phases of the system. Analytical expression for the Curie temperature,which takes the magnon fluctuations into account exactly, is obtained. For weak ferromagnets $T_c$ is well below the Stoner's critical temperature and the critical temperature obtained within Moriya's theory.Comment: 14 pages, changed content,new result