General Relaxation Research Articles

Boundary conditions for hyperbolic relaxation systems with characteristic boundaries of type II

This paper is a continuation of our preceding work on hyperbolic relaxation systems with characteristic boundaries of type I. Here we focus on the characteristic boundaries of type II, where the boundary is characteristic for the equilibrium system and is non-characteristic for the relaxation system. For this kind of characteristic initial-boundary-value problems (IBVPs), we introduce a three-scale asymptotic expansion to analyze the boundary-layer behaviors of the general multi-dimensional linear relaxation systems. Moreover, we derive the reduced boundary condition under the Generalized Kreiss Condition by resorting to some subtle matrix transformations and the perturbation theory of linear operators. The reduced boundary condition is proved to satisfy the Uniform Kreiss Condition for characteristic IBVPs. Its validity is shown through an error estimate involving the Fourier-Laplace transformation and an energy method based on the structural stability condition.

Persisting correlation between electrical transport and magnetic dynamics in M-type hexaferrites

In this work, we present frequency-dependent magnetic susceptibility and dc electric transport properties of three different compositions of hexaferrite Ba1−xPbxFe12−yAlyO19 single crystals. We found a correlation between the activation energies of the dc electric transport and the ac magnetic susceptibility which persists over the whole studied range of aluminum substitution y = 0–3.3. This result is discussed in the context of charged magnetic domain walls, the pinning of which is determined by charge carriers activated across the transport gap. Our work points toward a general relaxation mechanism in ferrimagnetic semiconductors that directly affects the dynamic magnetic properties via electrical transport.

Asymmetries in Perceptual Adjustments to Non-Canonical Pronunciations

This paper examines two plausible mechanisms supporting sound category adaptation: directional shifts towards the novel pronunciation or a general category relaxation of criteria. Focusing on asymmetries in adaptation to the voicing patterns of English coronal fricatives, we suggest that typology or synchronic experience affect adaptation. A corpus study of coronal fricative substitution patterns confirmed that North American English listeners are more likely to be exposed to devoiced /z/ than voiced /s/. Across two perceptual adaptation experiments, listeners in test conditions heard naturally produced devoiced /z/ or voiced /s/ in critical items within sentences, while control listeners were exposed to identical sentences with canonical pronunciations. Perceptual adaptation was tested via a lexical decision test, with devoiced /z/ or voiced /s/, as well as a novel alveopalatalized pronunciation, to determine whether adaptation was targeted in the direction of the exposed variant or reflected a more general relaxation. Results indicate there was directional and word-specific adaptation for /z/-devoicing with no evidence for generalization. Conversely, there was evidence of /s/-voicing generalizing and eliciting general category relaxation. These results underscore the role of perceptual experiences, and support an evaluation stage in perceptual learning, where listeners assess whether to update a representation.

BENEFITS OF USING INNOVATIVE TECHNOLOGIES IN AN ACTIVITIES OF SPORTS TEACHERS

In this article highlighted effective methods of teaching foreign languages in the field of physical culture and sport. Apart from that, it was written that the major responsibility for each of them is to carry out the human-forming function, when the lesson atmosphere is one of general labor, relaxation, and favorable conditions for the assimilation of new physical exercises.

Accuracy of STOP-Bang Questionnaire in Predicting Difficult Mask Ventilation: An Observational Study.

IntroductionDifficulty with bag-mask ventilation after the induction of general anesthesia and muscle relaxation places the patient at risk for a prolonged period of apnea and hypoxia and thus, at an increased risk of morbidity and mortality. This study was designed to assess the accuracy of the STOP-Bang questionnaire in predicting difficult mask ventilation (DMV) in patients receiving general anesthesia for elective surgical procedures.MethodsIt was a prospective cross-sectional, observational study conducted at a university teaching hospital. A total of 530 patients undergoing surgery under general anesthesia with endotracheal intubation were enrolled. STOP-Bang questionnaire was filled at pre-operative anesthesia assessment. Ease or difficulty of mask ventilation was assessed and documented by a senior resident responsible for intraoperative anesthetic management.ResultsOut of 530 patients, 139 (26.22%) had a STOP-Bang score of ≥ 3, of whom 55 (39.5%) were found to have DMV. Out of 391 patients with a STOP-Bang score of < 3, only 29 patients (7.5%) had DMV (P ≤0.001). Snoring, high blood pressure, BMI more than 35 kg/m2, age more than 50 years, neck circumference more than 40 cm, and male gender were significantly associated with DMV. The accuracy of the STOP-Bang questionnaire in predicting difficult mask ventilation was 78.68% (95% CI 74.99-81.95) with a negative predictive value of 92.58%. The sensitivity and specificity were found to be 65.48% and 81.17% respectively.ConclusionSTOP-Bang score has a high negative predictive value and can be very useful in ruling out the possibility of difficult mask ventilation.

A new integrated behavioural intervention for knee osteoarthritis: development and pilot study

BackgroundExercise-based approaches have been a cornerstone of physiotherapy management of knee osteoarthritis for many years. However, clinical effects are considered small to modest and the need for continued adherence identified as a barrier to clinical efficacy. While exercise-based approaches focus on muscle strengthening, biomechanical research has identified that people with knee osteoarthritis over activate their muscles during functional tasks. Therefore, we aimed to create a new behavioural intervention, which integrated psychologically informed practice with biofeedback training to reduce muscle overactivity, and which was suitable for delivery by a physiotherapist.MethodsThrough literature review, we created a framework linking theory from pain science with emerging biomechanical concepts related to overactivity of the knee muscles. Using recognised behaviour change theory, we then mapped a set of intervention components which were iteratively developed through ongoing testing and consultation with patients and physiotherapists.ResultsThe underlying framework incorporated ideas related to central sensitisation, motor responses to pain and also focused on the idea that increased knee muscle overactivity could result from postural compensation. Building on these ideas, we created an intervention with five components: making sense of pain, general relaxation, postural deconstruction, responding differently to pain and functional muscle retraining. The intervention incorporated a range of animated instructional videos to communicate concepts related to pain and biomechanical theory and also used EMG biofeedback to facilitate visualization of muscle patterns. User feedback was positive with patients describing the intervention as enabling them to “create a new normal” and to be “in control of their own treatment.” Furthermore, large reductions in pain were observed from 11 patients who received a prototype version of the intervention.ConclusionWe have created a new intervention for knee osteoarthritis, designed to empower individuals with capability and motivation to change muscle activation patterns and beliefs associated with pain. We refer to this intervention as Cognitive Muscular Therapy. Preliminary feedback and clinical indications are positive, motivating future large-scale trials to understand potential efficacy. It is possible that this new approach could bring about improvements in the pain associated with knee osteoarthritis without the need for continued adherence to muscle strengthening programmes.Trial registrationISRCTN51913166 (Registered 24-02-2020, Retrospectively registered).

Relaxation of strongly coupled binary ionic mixtures in the coupled mode regime

Understanding ion transport in plasma mixtures is essential for optimizing the energy balance in high-energy-density systems. In this paper, we focus on one transport property, ion–ion temperature relaxation in a strongly coupled plasma mixture. We review the physics of temperature relaxation and derive a general temperature relaxation equation that includes dynamical correlations. We demonstrate the fidelity of three popular kinetic models that include only static correlations by comparing them to data from molecular dynamics simulations. We verify the simulations by comparing with laboratory data from ultracold neutral plasmas. By comparing our simulations with high fidelity kinetic models, we reveal the importance of dynamical correlations in collisional relaxation processes. These correlations become increasingly significant as the ion mass ratio in a binary mixture approaches unity.

Vulnerable Roma communities in times of the Covid-19 negative quarantine

Abstract In contrast to other countries in East Central Europe, Romania stands out because of a high number of small and segregated Roma settlements. As an ethnic minority, the Roma are overrepresented in marginalised and impoverished settlements and, given the basic recommendations to contain the pandemic – wash hands, keep the distance and work from home, their situation was disproportionately exacerbated by the imposition of lockdown measures. We use secondary data to interpret the deprivation features that puts them at greater epidemic risk. In addition, the Covid-19 crisis led to a sudden return of the Romanian Roma living in Western Europe. The slums and ghettos were more strictly quarantined than regular areas, suggesting a form of negative quarantine. Quarantine was – next to its medical purpose – used as a rhetoric and disciplinary device. Roma were portrayed as infection spreaders, and racism was channelled mainly through the media. While the spread of the disease placed them at risk, the lockdown itself induced major survival challenges. By using media and social media analysis, we show how the discourse of negative quarantine unfolded. The latter was diluted in the general relaxation of containment measures, but its legacy as a practice raises questions for the future governance of areas inhabited by the Roma.

Prescribing patterns for treating common complications of spinal cord injury

Objective The purpose of this study was to find the most and least commonly prescribed medications for treating secondary health complications associated with spinal cord injury (SCI); and determine overall polypharmacy rates and risk factors associated with it. Design Observational design, cross-sectional analysis. Setting Community; Canada. Participants Individuals with spinal cord injury (n = 108). Results A total of 515 prescriptions were issued to the sample comprising 213 different medications to treat 10 SCI-related complications. Forty-five (45%) participants were prescribed >5 medications concurrently. No associations were found between the number of drugs taken and age, sex, level of injury, completeness of injury, time since injury, or cause of injury. The most commonly treated complications included pain (56.5%), muscle spasms (54%) and urinary tract infections (43%). Anti-convulsants (pregabalin, gabapentin), anti-spasmodics (baclofen, diazepam) and nitrofurantoins (Macrobid) were the most commonly prescribed medications to treat each of the three conditions, respectively. Thirty five percent of the total sample received a combination of two or more analgesics including fourth-line agents in the opiate class (hydromorphone, hydrocodone and morphine). Similarly, some participants were prescribed general muscle relaxants and cephalosporins for treatment of muscle spasms and urinary tract infections, respectively, that are generally not recommended in SCI patients. We compare these prescribing patterns with the available clinical practice guidelines and highlight areas where the prescriptions fall outside the recommended clinical practice while considering the complexity of medication management in SCI. Conclusion Medication management in SCI is complex. Tools are required that enable prescribers to choose evidence-based medical regimens and deprescribe potentially inappropriate medications for their patients with SCI.

Characterization of Dissipative Structures for First-Order Symmetric Hyperbolic System with General Relaxation

In this paper, we study the dissipative structure of first-order linear symmetric hyperbolic system with general relaxation and provide the algebraic characterization for the uniform dissipativity up to order 1. Our result extends the classical Shizuta–Kawashima condition for the case of symmetric relaxation, with a full generality and optimality.

A formulation of the relaxation phenomenon for lane changing dynamics in an arbitrary car following model

Lane changing dynamics are an important part of traffic microsimulation and are vital for modeling weaving sections and merge bottlenecks. However, there is often much more emphasis placed on car following and gap acceptance models, whereas lane changing dynamics such as tactical, cooperation, and relaxation models receive comparatively little attention. This paper develops a general relaxation model which can be applied to an arbitrary parametric or nonparametric microsimulation model. The relaxation model modifies car following dynamics after a lane change, when vehicles can be far from equilibrium. Relaxation prevents car following models from reacting too strongly to the changes in space headway caused by lane changing, leading to more accurate and realistic simulated trajectories. We also show that relaxation is necessary for correctly simulating traffic breakdown with realistic values of capacity drop.

Excited state dynamics of 7-deazaguanosine and guanosine 5'-monophosphate.

Minor structural modifications to the DNA and RNA nucleobases have a significant effect on their excited state dynamics and electronic relaxation pathways. In this study, the excited state dynamics of 7-deazaguanosine and guanosine 5'-monophosphate are investigated in aqueous solution and in a mixture of methanol and water using femtosecond broadband transient absorption spectroscopy following excitation at 267 nm. The transient spectra are collected using photon densities that ensure no parasitic multiphoton-induced signal from solvated electrons. The data can be fit satisfactorily using a two- or three-component kinetic model. By analyzing the results from steady-state, time-resolved, computational calculations, and the methanol-water mixture, the following general relaxation mechanism is proposed for both molecules, Lb → La → 1πσ*(ICT) → S0, where the 1πσ*(ICT) stands for an intramolecular charge transfer excited singlet state with significant πσ* character. In general, longer lifetimes for internal conversion are obtained for 7-deazaguanosine compared to guanosine 5'-monophosphate. Internal conversion of the 1πσ*(ICT) state to the ground state occurs on a similar time scale of a few picoseconds in both molecules. Collectively, the results demonstrate that substitution of a single nitrogen atom for a methine (C-H) group at position seven of the guanine moiety stabilizes the 1ππ* Lb and La states and alters the topology of their potential energy surfaces in such a way that the relaxation dynamics in 7-deazaguanosine are slowed down compared to those in guanosine 5'-monophosphate but not for the internal conversion of 1πσ*(ICT) state to the ground state.

Efficient Multicontact Pattern Generation With Sequential Convex Approximations of the Centroidal Dynamics

This paper investigates the problem of efficient computation of physically consistent multi-contact behaviors. Recent work showed that under mild assumptions, the problem could be decomposed into simpler kinematic and centroidal dynamic optimization problems. Based on this approach, we propose a general convex relaxation of the centroidal dynamics leading to two computationally efficient algorithms based on iterative resolutions of second order cone programs. They optimize centroidal trajectories, contact forces and, importantly, the timing of the motions. We include the approach in a kino-dynamic optimization method to generate full-body movements. Finally, the approach is embedded in a mixed-integer solver to further find dynamically consistent contact sequences. Extensive numerical experiments demonstrate the computational efficiency of the approach, suggesting that it could be used in a fast receding horizon control loop. Executions of the planned motions on simulated humanoids and quadrupeds and on a real quadruped robot further show the quality of the optimized motions.

Enchantment in an Age of Reform: Fortune-Telling Fever in Post-Mao China, 1980s–1990s*

Abstract Soon after the death of Mao Zedong in 1976, China experienced a ‘fortune-telling fever’. After having been suppressed by the Chinese Communist Party for the previous three decades, fortune tellers re-emerged in the 1980s to publish extensively on the topic and ply their trade in public. Yet despite the general relaxation of state policies toward folk beliefs, fortune telling was still considered a ‘superstition’ and therefore remained against the law. To bypass ongoing proscriptions against divinatory practices and publications, fortune tellers began to frame their undertakings in a language that closely mirrored two priorities of the post-Mao state: the advancement of scientific research and the reclamation of traditional culture. As this article argues, the example of China’s fortune-telling fever adds a new perspective to studies that have viewed the resurgence of Chinese spirituality as a form of communal resistance against an atheist regime. Rather than combating the government’s accusation that their practices were superstitious, fortune tellers instead positioned themselves as allies of the state by appealing to its rhetoric of science and cultural nationalism. Downplaying the mystical qualities of their craft, they framed divination as an academic and economic endeavour, one that was both compatible with secular modernity and in keeping with the Chinese Communist Party’s demands for entrepreneurial activity.

Current standard of care in treatment of bladder pain syndrome/interstitial cystitis.

Bladder pain syndrome/interstitial cystitis (BPS/IC) is a debilitating, systemic pain syndrome with a cardinal symptom of bladder related pain with associated systemic symptoms. It is characterized by an inflammation that partially or completely destroys the mucus membrane and can extend into the muscle layer; however, the etiology and pathogenesis is still enigmatic. It has been suggested that mast cell activation, defects in the glycosaminoglycan layer, non-functional proliferation of bladder epithelial cells, neurogenic inflammation, microvascular abnormalities in the submucosal layer, autoimmunity and infectious causes may cause BPS/IC. Available treatment options include general relaxation techniques, patient education, behavioral treatments, physical therapy, multimodal pain therapy, oral (amitriptyline, cimetidine, hydroxyzine) and intravesical treatments (heparin, lidocaine, hyaluronic acid and chondroitin sulfate), hydrodistension and other more invasive treatments. Available treatments are mostly not based on a high level of evidence. Lack of understanding of disease mechanisms has resulted in lack of targeted therapies on this area and a wealth of empirical approaches with usually inadequate efficacy. The aim of this article is to review the available evidence on the pathophysiological mechanisms of BPS/IC as they relate to available treatment options.

General decay results for a viscoelastic wave equation with a variable exponent nonlinearity

In this paper we consider a viscoelastic wave equation with a very general relaxation function and nonlinear frictional damping of variable-exponent type. We give explicit and general decay results for the energy of the system depending on the decay rate of the relaxation function and the nature of the variable-exponent nonlinearity. Our results extend the existing results in the literature to the case of nonlinear frictional damping of variable-exponent type.

Evaluation of Audit Electroconvulsive Therapy Service in Psychiatric Unit at Mosul City

Background: ECT is a procedure usually performed under general anesthesia and muscle relaxation in which modified seizures induced by the selective passage of an electrical current through the brain are used for therapeutic purposes.

Global existence and exponential stability of coupled Lam\xe9 system with distributed delay and source term without memory term

In this paper, we prove the global existence and exponential energy decay results of a coupled Lamé system with distributed time delay, nonlinear source term, and without memory term by using the Faedo–Galerkin method. In addition, an appropriate Lyapunov functional, more general relaxation functions, and some properties of convex functions are considered.

The weakly nonlinear response and nonaffine interpretation of the Johnson–Segalman/Gordon–Schowalter model

We derive new analytical solutions for the nonaffine Johnson–Segalman/Gordon–Schowalter (JS/GS) constitutive equation with a general relaxation kernel in medium-amplitude oscillatory shear (MAOS) deformation. The results show time-strain separable (TSS) nonlinearity, therefore providing new physically meaningful interpretation to the heuristic TSS nonlinear parameter in MAOS [Martinetti and Ewoldt, Phys. Fluids 31, 021213 (2019)]. The upper-convected, lower-convected, and corotational Maxwell models are all subsets of the results presented here. The model assumes that the microscale elements causing stress in the material slip compared to the continuum deformation. We introduce a visualization of the nonaffine deformation field that acts on stress-generating elements to reinforce the physical interpretation of the JS/GS class of models. Finally, a case study is presented where previously published results, from fitting TSS models to MAOS data, can be reinterpreted based on the concept of nonaffine motion of the JS/GS framework.

Determining Public Opinion of the COVID-19 Pandemic in South Korea and Japan: Social Network Mining on Twitter.

ObjectivesThis study analyzed the perceptions and emotions of Korean and Japanese citizens regarding coronavirus disease 2019 (COVID-19). It examined the frequency of words used in Korean and Japanese tweets regarding COVID-19 and the corresponding changes in their interests.MethodsThis cross-sectional study analyzed Twitter posts (Tweets) from February 1, 2020 to April 30, 2020 to determine public opinion of the COVID-19 pandemic in Korea and Japan. We collected data from Twitter (https://twitter.com/), a major social media platform in Korea and Japan. Python 3.7 Library was used for data collection. Data analysis included KR-WordRank and frequency analyses in Korea and Japan, respectively. Heat diagrams, word clouds, and rank flowcharts were also used.ResultsOverall, 1,470,673 and 4,195,457 tweets were collected from Korea and Japan, respectively. The word trend in Korea and Japan was analyzed every 5 days. The word cloud analysis revealed “COVID-19”, “Shinchonji”, “Mask”, “Daegu”, and “Travel” as frequently used words in Korea. While in Japan, “COVID-19”, “Mask”, “Test”, “Impact”, and “China” were identified as high-frequency words. They were divided into four categories: social distancing, prevention, issue, and emotion for the rank flowcharts. Concerning emotion, “Overcome” and “Support” increased from February in Korea, while “Worry” and “Anxiety” decreased in Japan from April 1.ConclusionsAs a result of the trend, people’s interests in the economy were high in both countries, indicating their reservations on the economic down-turn. Therefore, focusing policies toward economic stability is essential. Although the interest in prevention increased since April in both countries, the general public’s relaxation regarding COVID-19 was also observed.