Basic Relaxation Research Articles

Relaxation and fluctuations of a mass- and dipole-conserving stochastic lattice gas

Han [] have recently introduced a classical stochastic lattice gas model which, in addition to particle conservation, also conserves the particles' dipole moment. Because of its intrinsic nonlinearity this model exhibits unusual macroscopic scaling behaviors, different from those of lattice gases that conserve only the number of particles. Here we investigate some basic relaxation and fluctuation properties of this model at large scales and at long times. These properties crucially depend on whether the total number of particles is infinite or finite. We find similarity solutions, describing relaxation of the dipole-conserving gas (DCG) in several standard settings. A major part of our effort is an extension to this model of the macroscopic fluctuation theory (MFT), previously developed for lattice gases where only the number of particles is conserved. We apply the MFT to the calculation of the variance of nonequilibrium fluctuations of the excess number of particles on the positive semi-axis when starting from an (either deterministic, or random) constant density at t=0. Using the MFT, we also identify the equilibrium Boltzmann-Gibbs distribution for the DCG. Finally, based on these results, we determine the probability distribution of, and the most probable density history leading to, a large deviation in the form of a macroscopic void of a given size in an initially uniform DCG at equilibrium. Published by the American Physical Society 2024

On the Complexity of Symmetric vs. Functional PCSPs

The complexity of the promise constraint satisfaction problem \(\operatorname{(PCSP)}(\mathbf{A},\mathbf{B})\) is largely unknown, even for symmetric \(\mathbf{A}\) and \(\mathbf{B}\) , except for the case when \(\mathbf{A}\) and \(\mathbf{B}\) are Boolean. First, we establish a dichotomy for \(\operatorname{PCSP}(\mathbf{A},\mathbf{B})\) where \(\mathbf{A},\mathbf{B}\) are symmetric, \(\mathbf{B}\) is functional (i.e., any \(r-1\) elements of an \(r\) -ary tuple uniquely determines the last one), and \((\mathbf{A},\mathbf{B})\) satisfies technical conditions we introduce called dependency and additivity . This result implies a dichotomy for \(\operatorname{PCSP}(\mathbf{A},\mathbf{B})\) with \(\mathbf{A},\mathbf{B}\) symmetric and \(\mathbf{B}\) functional if (i) \(\mathbf{A}\) is Boolean, or (ii) \(\mathbf{A}\) is a hypergraph of a small uniformity, or (iii) \(\mathbf{A}\) has a relation \(R^{\mathbf{A}}\) of arity at least three such that the hypergraph diameter of \((A,R^{\mathbf{A}})\) is at most one. Second, we show that for \(\operatorname{PCSP}(\mathbf{A},\mathbf{B})\) , where \(\mathbf{A}\) and \(\mathbf{B}\) contain a single relation, \(\mathbf{A}\) satisfies a technical condition called balancedness , and \(\mathbf{B}\) is arbitrary, the combined basic linear programming relaxation and the affine integer programming (AIP) relaxation is no more powerful than the (in general strictly weaker) \({{\rm AIP}}\) relaxation. Balanced \(\mathbf{A}\) include symmetric \(\mathbf{A}\) or, more generally, \(\mathbf{A}\) preserved by a transitive permutation group.

Relaxed minds for healthier food choice at school: A field experiment in southern Mexico

Stress leads to unhealthy food choices since the school-age stage. Yet, there is limited evidence particularly in low- and middle-income countries regarding the impact of stress-reduction strategies on school-age children's food choices. Such aspects were crucial during the recent COVID-19 pandemic, which exacerbated psychological distress and unhealthier food choices among children. Two years after the pandemic began, we conducted a field experiment in southern Mexico to assess the impact of stress-reduction strategies on the food choices of over 1400 children aged 9–12. Half of the school-classes in the sample were randomly assigned to a stress reduction strategy namely meditation, which comprised six audios with basic relaxation techniques and intuitive messages to guide food choices. Additionally, all participants received information signalling that an amaranth snack was nutritious (i.e., the healthy snack), which was paired with a chocolate bar (i.e., the unhealthy snack) as part of a snack choice experiment. Students that practiced meditation were slightly more likely to choose the healthy snack than those in the control group, but the effect was not statistically significant. Upon collecting their snack, students had the chance to exchange their original choice for the other snack. Students that meditated were more likely to exchange their originally chosen “unhealthy snack” towards the healthy snack than students in the control group. The meditation program effectively reduced chronic stress among treated children. The effect was larger among students attending schools in lower-income areas. Our study sheds some light on the challenges to translate an improved psychological well-being into healthier food choices at school.

Formation and assessment of psycho-emotional resistance of school students at boxing classes in the process of physical education

The article substantiates the need to increase attention to the assessment and formation of the psycho-emotional stability of the body in order to preserve the mental and somatic health of students in the conditions of schooling. It is shown that martial arts, and in particular boxing, have a high potential for the development of motor qualities, the education of strong-willed personality characteristics due to the situational nature of motor loads, which involves overcoming fatigue, pain, restraining emotions and maintaining an optimal level of work capacity in conditions of psycho-emotional stress. The criteria for evaluating the educational achievements of high school students in the process of boxing classes are proposed, taking into account psycho-emotional stability, which includes the assessment of the level of theoretical preparation, general and special motor preparedness, willpower indicators, educational standards are developed for assessing the general motor, special preparedness of assessment and psycho-emotional stability of students 10-11 grades in the process of boxing. The content of boxing classes for the formation of psycho-emotional stability of high school students is determined based on the use of means and methods aimed at the formation of motivation, theoretical knowledge, techniques and tactics of boxing, the development and education of motor and volitional prognostic signs of psycho-emotional stability of students. Means of formation of psycho-emotional stability of high school students in the process of boxing include general development, preparatory, underwater and basic boxing exercises, breathing and relaxation exercises. Used practical methods of teaching the exercise, methods of developing motor qualities (continuous, interval, repeated) and methods of combined influence (circular, game, competitive), educational methods.

The short- and long-term effects of yoga on relaxation states measured by the Smith Relaxation States Inventory 3

IntroductionThe beneficial effects of yoga have been researched for decades, and in some countries it is also used in health care to maintain physical and mental health. Its effectiveness in the treatment of stress and anxiety, as well as in achieving a relaxed state, is supported by numerous studies.Objectives In the present research, our aim was to investigate the direct and subclinical effects of yoga, where the subjects did at least 10 minutes of yoga a day for two weeks. Our hypotheses are that the participants experience relaxation, mindfulness and positive emotions significantly (1) more often and (2) more intensely as a result of yoga.MethodsWe included 25 average population, healthy people between the ages of 18 and 30, who exercised at least 10 minutes of yoga a day for two weeks with the help of a mobile app. We used the Smith Relaxation States Inventory (SRSI3) and its disposition-measuring version (SRSI3d), which examine 19 relaxation states (R-states) presumably related to relaxation, divided into 4 categories: basic relaxation, mindfulness, positive energy and transcendence. During the statistical analyses, the values taken at the beginning of the research, before practice, were compared with the values taken directly after the last practice using the Wilcoxon test. Bonferroni correction was used to correct the first-order error that increases when testing several hypotheses simultaneously.ResultsImmediately after practicing yoga, the participants had significantly higher basic relaxation (M0=2.74, M1=4.24, p<0.0001), awareness (M0=2.71, M1=2.89, p<0.0001) and positive energy (M0=3.88, M1= 4.81, p<0.0001) and in the long term they experienced significantly more relaxation (M0=3.12, M1=3.94, p<0.0001), awareness (M0=3.41, M1=4.40, p<.0001), positive energy (M0= 4.39, M1=5.14, p<0.001) and transcendence (M0=3.23, M1=4.05, p=0.001).Conclusions Based on our results, yoga can be an effective additional tool in maintaining and improving health, but also in improving the condition and quality of life of mental and somatic patients.Disclosure of InterestNone Declared

Managing Rheumatological Shoulder Pain in ADL

Background Rheumatological disease induced shoulder pain could affect most of the ADLs and work requiring shoulder height and upper arm rotation such as combing hair, pulling pants up, and reaching for something in a cabinet. Pain affects the stability of hands making difficulties in using chopsticks and make-up. Pain also affects sleep quality and psychological factors such as stress and depression. Methods Occupational therapy (OT) aimed to alleviate pain, prevent further deterioration, promote independence in ADL, work, and leisure by means of fascia therapy, mobilization and strengthening; training on proper body mechanics; fabricating splinting to enhance structural support; prescription of aids and gadgets; and self-management strategies. Results During flare up, OT educate patient to minimize stress on shoulder joint, such as inflammatory self-management and gentle stretch of surrounding muscles, mobilization, and proper body mechanics in ADLs. Aggressive stretching should be avoided. Specific joint protection techniques to avoid extra stress on shoulder during their ADL and work includes proper head and neck position with supporting devices; avoid side lying on the painful side when sleeping etc. In addition, avoid over generalization of basic joint protection techniques, e.g., carrying heavy bags on forearm may increase loading to the shoulder; while using small wheeled-trolley to carry heavy things in damping road may cause impact to shoulder. Instead, using small towel to minimize rotational force on shoulder; and use upper body part to push heavy door in shopping centre to minimize the impact loading on shoulder joint, etc. On the other hand, training on basic relaxation techniques like breathing focus or progressive muscle relaxation could allow relieve pain. For muscle strengthening, muscle balance must be the basic consideration by means of pendulum exercise, and progress to isometric and eccentric training. Strengthen core and upper back muscles should be included to provide basic stability. Conclusion Patient with severe shoulder instability but not fit to receive surgery, could result in pain and functional deficit. Thus, patient is encouraged to compile on different bracing, e.g., AC joint brace or shoulder sling for certain period to optimize joint stability and pain. Alternative ADL and work strategies e.g., lowering the working area or using safety ladder; and utilizing some aids e.g., long-handle reacher, and electrical screw driver, could promote their independence. Advanced technology could also be employed like exo-skeleton device promote patient’s function independence ADLs and work independence.

AI-designed NMR spectroscopy RF pulses for fast acquisition at high and ultra-high magnetic fields

Nuclear magnetic resonance (NMR) spectroscopy is a powerful high-resolution tool for characterizing biomacromolecular structure, dynamics, and interactions. However, the lengthy longitudinal relaxation of the nuclear spins significantly extends the total experimental time, especially at high and ultra-high magnetic field strengths. Although longitudinal relaxation-enhanced techniques have sped up data acquisition, their application has been limited by the chemical shift dispersion. Here we combined an evolutionary algorithm and artificial intelligence to design 1H and 15N radio frequency (RF) pulses with variable phase and amplitude that cover significantly broader bandwidths and allow for rapid data acquisition. We re-engineered the basic transverse relaxation optimized spectroscopy experiment and showed that the RF shapes enhance the spectral sensitivity of well-folded proteins up to 180 kDa molecular weight. These RF shapes can be tailored to re-design triple-resonance experiments for accelerating NMR spectroscopy of biomacromolecules at high fields.

Relaxation spectral analysis in multi-contrast vascular magnetic particle imaging.

Magnetic nanoparticles (MNPs) are used as tracers without ionizing radiation in vascular imaging, molecular imaging, and neuroimaging. The relaxation mechanisms of magnetization in response to excitation magnetic fields are important features of MNPs. The basic relaxation mechanisms include internal rotation (Néel relaxation) and external physical rotation (Brownian relaxation). Accurate measurement of these relaxation times may provide high sensitivity for predicting MNP types and viscosity-based hydrodynamic states. It is challenging to separately measure the Néel and Brownian relaxation components using sinusoidal excitation in conventional MPI. We developed a multi-exponential relaxation spectral analysis method to separately measure the Néel and Brownian relaxation times in the magnetization recovery process in pulsed vascular MPI. Synomag-D samples with different viscosities were excited using pulsed excitation in a trapezoidal-waveform relaxometer. The samples were excited at different field amplitudes ranging from 0.5 to 10 mT at intervals of 0.5 mT. The inverse Laplace transform-based spectral analysis of the relaxation-induced decay signal in the field-flat phase was performed by using PDCO, a primal-dual interior method for convex objectives. Néel and Brownian relaxation peaks were elucidated and measured on samples with various glycerol and gelatin concentrations. The sensitivity of viscosity prediction of the decoupled relaxation times was evaluated. A digital vascular phantom was designed to mimic a plaque with viscous MNPs and a catheter with immobilized MNPs. Spectral imaging of the digital vascular phantom was simulated by combining a field-free point with homogeneous pulsed excitation. The relationship between the Brownian relaxation time from different tissues and the number of periods for signal averages was evaluated for a scan time estimation in the simulation. The relaxation spectra of synomag-D samples with different viscosity levels exhibited two relaxation time peaks. The Brownian relaxation time had a positive linear relationship with the viscosity in the range 0.9 to 3.2 mPa · s. When the viscosity was >3.2 mPa · s, the Brownian relaxation time saturated and did not change with increasing viscosity. The Néel relaxation time decreased slightly with an increase in the viscosity. The Néel relaxation time exhibited a similar saturation effect when the viscosity level was >3.2 mPa · s for all field amplitudes. The sensitivity of the Brownian relaxation time increased with the field amplitude and was maximized at approximately 4.5 mT. The plaque and catheter regions were differentiated from the vessel region in the simulated Brownian relaxation time map. The simulation results show that the Néel relaxation time was 8.33±0.09 μs in the plaque region, 8.30±0.08 μs in the catheter region, and 8.46±0.11 μs in the vessel region. The Brownian relaxation time was 36.60±2.31 μs in the plaque region, 30.17±1.24 μs in the catheter region, and 31.21±1.53 μs in the vessel region. If we used 20 excitation periods for image acquisition in the simulation, the total scan time of the digital phantom was approximately 100 s. Quantitative assessment of the Néel and Brownian relaxation times through inverse Laplace transform-based spectral analysis in pulsed excitation, highlighting their potential for use in multi-contrast vascular MPI.

CLAP: A New Algorithm for Promise CSPs

We propose a new algorithm for Promise Constraint Satisfaction Problems (PCSPs). It is a combination of the Constraint Basic LP relaxation and the Affine IP relaxation (CLAP). We give a characterization of the power of CLAP in terms of a minion homomorphism. Using this characterization, we identify a certain weak notion of symmetry which, if satisfied by infinitely many polymorphisms of PCSPs, guarantees tractability. We demonstrate that there are PCSPs solved by CLAP that are not solved by any of the existing algorithms for PCSPs; in particular, not by the algorithm of Brakensiek et al. [SIAM J. Comput., 49 (2020), pp. 1232--1248] and not by a reduction to tractable finite-domain CSPs.

The Complexity of the Distributed Constraint Satisfaction Problem

We study the complexity of the Distributed Constraint Satisfaction Problem (DCSP) on a synchronous, anonymous network from a theoretical standpoint. In this setting, variables and constraints are controlled by agents which communicate with each other by sending messages through fixed communication channels. Our results endorse the well-known fact from classical CSPs that the complexity of fixed-template computational problems depends on the template’s invariance under certain operations. Specifically, we show that DCSP(Γ) is polynomial-time tractable if and only if Γ is invariant under symmetric polymorphisms of all arities. Otherwise, there are no algorithms that solve DCSP(Γ) in finite time. We also show that the same condition holds for the search variant of DCSP. Collaterally, our results unveil a feature of the processes’ neighbourhood in a distributed network, its iterated degree, which plays a major role in the analysis. We explore this notion establishing a tight connection with the basic linear programming relaxation of a CSP.

A very fast method for guaranteed generation of one facet for 0-1 knapsack polyhedron

The 0-1 knapsack polyhedron as the most basic relaxation of a 0-1 integer program has attracted attention of many researchers over the years.We present a very fast method that is guaranteed to generate one facet for the 0-1 knapsack polyhedron. Unlike lifting of cover inequlities, our method does not require an initial minimal cover or a predetermined lifting sequencing, and its worst-case complexity is linear in number of variables. Therefore, it is suitable for incorporation into mixed interger programming(MIP) solvers, in order to generate, with negligible computational burden, one strong cut based on any 0-1 knapsack relaxation of a general MIP.

Piecewise Linear Valued CSPs Solvable by Linear Programming Relaxation

Valued constraint satisfaction problems (VCSPs) are a large class of combinatorial optimisation problems. The computational complexity of VCSPs depends on the set of allowed cost functions in the input. Recently, the computational complexity of all VCSPs for finite sets of cost functions over finite domains has been classified. Many natural optimisation problems, however, cannot be formulated as VCSPs over a finite domain. We initiate the systematic investigation of the complexity of infinite-domain VCSPs with piecewise linear homogeneous cost functions. Such VCSPs can be solved in polynomial time if the cost functions are improved by fully symmetric fractional operations of all arities. We show this by reducing the problem to a finite-domain VCSP which can be solved using the basic linear program relaxation. It follows that VCSPs for submodular PLH cost functions can be solved in polynomial time; in fact, we show that submodular PLH functions form a maximally tractable class of PLH cost functions.

MADAM: a parallel exact solver for max-cut based on semidefinite programming and ADMM

We present MADAM, a parallel semidefinite-based exact solver for Max-Cut, a problem of finding the cut with the maximum weight in a given graph. The algorithm uses the branch and bound paradigm that applies the alternating direction method of multipliers as the bounding routine to solve the basic semidefinite relaxation strengthened by a subset of hypermetric inequalities. The benefit of the new approach is a less computationally expensive update rule for the dual variable with respect to the inequality constraints. We provide a theoretical convergence of the algorithm as well as extensive computational experiments with this method, to show that our algorithm outperforms state-of-the-art approaches. Furthermore, by combining algorithmic ingredients from the serial algorithm, we develop an efficient distributed parallel solver based on MPI.

Do Relaxation Exercises Decrease Pain After Arthroscopic Rotator Cuff Repair? A Randomized Controlled Trial.

Pain after rotator cuff repair is commonly managed with opioid medications; however, these medications are associated with serious adverse effects. Relaxation exercises represent a potential nonpharmacologic method of pain management that can be easily implemented without substantial adverse effects; however, the effects of relaxation exercises have not been studied in a practical, reproducible protocol after arthroscopic rotator cuff repair. (1) Does performing relaxation exercises after arthroscopic rotator cuff repair (ARCR) decrease pain compared with standard pain management medication? (2) Does performing relaxation exercises after ARCR decrease opioid consumption? (3) What proportion of patients who used the relaxation techniques believed they decreased their pain level, and what proportion continued using these techniques at 2 weeks? (4) Does performing relaxation exercises after ARCR affect shoulder function? During the study period, 563 patients were eligible for inclusion; however, only 146 were enrolled, randomized, and postoperatively followed (relaxation group: 74, control group: 72); 68% (384 of 563) of patients were not contacted due to patient and research staff availability. Thirty-three patients were unenrolled preoperatively or immediately postoperatively due to change in operative procedure (such as, only debridement) or patient request; no postoperative data were collected from these patients. Follow-up proportions were similar between the relaxation and control groups (relaxation: 80%, control: 81%; p = 0.90). The relaxation group received and reviewed educational materials consisting of a 5-minute video and an educational pamphlet explaining relaxation breathing techniques, while the control group did not receive relaxation education materials. Patients recorded their pain levels and opioid consumption during the 5 days after ARCR. Patients also completed the American Shoulder and Elbow Surgeons shoulder score preoperatively and 2, 6, 13, 18, and 26 weeks postoperatively. Linear mixed models were created to analyze postoperative pain, opioid consumption measured in morphine milligram equivalents (MMEs), and shoulder function outcomes. A per-protocol approach was used to correct for patients who were enrolled but subsequently underwent other procedures. There was no difference in pain scores between the relaxation and control groups during the first 5 days postoperatively. There was no difference in pain scores at 2 weeks postoperatively between the relaxation and control groups (3.3 ± 3 versus 3.5 ± 2, mean difference -0.22 [95% CI -1.06 to 0.62]; p = 0.60). There was no difference in opioid consumption during the first 5 days postoperatively between the relaxation and control groups. The use of relaxation exercises resulted in lower 2-week narcotics consumption in the relaxation group than in the control group (309 ± 241 MMEs versus 442 ± 307 MMEs, mean difference -133 [95% CI -225 to -42]; p < 0.01). Sixty-two percent (41 of 66) of patients in the relaxation group believed the relaxation exercises decreased their pain levels. Fifty-two percent (34 of 66) were still performing the exercises at 2 weeks postoperatively. During the 6-month follow-up period, there was no difference in shoulder function between the relaxation and control groups. The preoperative administration of quick, basic relaxation exercises allowed patients to use appreciably lower opioid analgesic doses over the first 2 weeks after ARCR, without any worsening of pain scores. We consider this result promising but preliminary; it is possible that a more intense mindfulness intervention-the one we studied here was disseminated using only a 5-minute video-would deliver reductions in pain and further reductions in opioid usage. Level II, therapeutic study.

Hubungan Senam Hamil dengan Lama Tidur Ibu Hamil Trimester III di Puskesmas Putri Ayu Kota Jambi

Pregnancy is a period that is eagerly awaited by mothers. In conditions of pregnancy there are hormonal and physiological changes. The changes that occur are expected to be carried out by pregnant women in order to have a comfortable pregnancy. Sleep disturbance is one of the complaints that occurs during pregnancy, the complaint is caused by various physiological, hormonal, vascular and metabolic changes. Empirical studies show that up to 25% of pregnant women report significant sleep disturbances in the first trimester, with rates rising to 75% in the first trimester. third trimester. Overcoming sleep disorders during pregnancy can be done in various ways in order to stabilize good sleep quality, such as determining a good and comfortable sleeping position while sleeping, basic relaxation exercises, one of which is pregnancy exercise. This study aims to determine the relationship between pregnancy exercise and sleep duration of pregnant women. Quantitative research design. The subjects in this study were pregnant women in their third trimester at Puskesmas Putri Ayu Jambi City. The subjects of the study were seen the length of sleep for pregnant women before doing pregnancy exercise and the length of sleep for pregnant women after participating in pregnancy exercise classes. The research was conducted at the Putri Ayu Health Center, Jambi City. The collected data will be analyzed univariately. It is hoped that the results of this study can be used as a source of information for pregnant women about physiological changes during pregnancy and can overcome complaints of difficulty sleeping by doing pregnancy exercise.Keywords: exercise for pregnancy, pregnant women, sleep duration

Structure and Dynamics of Ribonuclease A during Thermal Unfolding: The Failure of the Zimm Model.

Disordered regions as found in intrinsically disordered proteins (IDP) or during protein folding define response time to stimuli and protein folding times. Neutron spin-echo spectroscopy is a powerful tool to directly access the collective motions of the unfolded chain to enlighten the physical origin of basic conformational relaxation. During the thermal unfolding of native ribonuclease A, we examine the structure and dynamics of the disordered state within a two-state transition model using polymer models, including internal friction, to describe the chain dynamics. The presence of four disulfide bonds alters the disordered configuration to a more compact configuration compared to a Gaussian chain that is defined by the additional links, as demonstrated by coarse-grained simulation. The dynamics of the disordered chain is described by Zimm dynamics with internal friction (ZIF) between neighboring amino acids. Relaxation times are dominated by mode-independent internal friction. Internal friction relaxation times show an Arrhenius-like behavior with an activation energy of 33 kJ/mol. The Zimm dynamics is dominated by internal friction and suggest that the characteristic motions correspond to overdamped elastic modes similar to the motions observed for folded proteins but within a pool of disordered configurations spanning the configurational space. For IDP, internal friction dominates while solvent friction and hydrodynamic interactions are smaller corrections.

Energy deposition parameters revealed in the transition from 3D to 1D femtosecond laser ablation of fluorite at high-NA focusing

Ultrashort-pulse laser surface and bulk nano- and micromachining of dielectrics have multiple promising applications in micro-optics, microfluidics, and memory storage. The fundamental principles relate intrinsic inter-band multi-photon (MPA) and laser-induced intra-band free-carrier absorption (FCA) to particular ablation mechanisms and features. These principles are yet to be quantified into a complete set of basic experimental laser-matter interaction parameters, describing photoexcitation, relaxation, and final ablation. In this study, we considered the characteristic double-crater structure of single-shot ablation spots on dielectric surfaces and single-shot transmission spectra to extract crucial information about the underlying basic processes of ultrafast photoexcitation and laser energy deposition. Specifically, energy-dependent crater profiles and accompanying prompt self-phase modulation (SPM) spectral broadening were studied in single-shot surface ablation experiments on fluorite (CaF2) surface photo-excited by tightly focused 515- or 1030-nm, 300-fs laser pulses. Crater size dependence demonstrated two slopes, scaling proportionally to the squared focal 1/e-radius at higher energies (intensities) for larger ablated spots, and a much smaller squared 1/e-radius at lower energies (intensities) for (sub) micron-wide ablated spots, indicating a transition from 1D to 3D-ablation. As a result, these slopes were related to lower-intensity wavelength-dependent multi-photon inter-band transitions and wavelength-independent higher-intensity linear absorption in the emerging near-critical electron-hole plasma (EHP), respectively. Crater depth dependences on the local laser intensity fitted in the corresponding ranges by multi- and one-photon absorption provided the corresponding absorption coefficients. Spectral broadening measurements indicated even values for the red and blue shoulders of the laser pulse spectrum, representing the SPM effect in the weakly excited fluorite at the leading pulse front and providing the corresponding Kerr coefficient. In the second regime, the blue-shoulder broadening value saturated, indicating the appearance of near-critical plasma screening at the trailing pulse front, which is consistent with our calculations. These complementary experiments and related analysis provided an important set of key basic parameters, characterizing not only surface ablation, but also propagation of high-intensity ultrashort laser pulses in bulk fluorite, and enabling precise forecasting of optimal energy deposition for high-efficiency ultrashort-laser micro-structuring of this dielectric material.

Influence of Surface Ligands on Charge-Carrier Trapping and Relaxation in Water-Soluble CdSe@CdS Nanorods

In this study, the impact of the type of ligand at the surface of colloidal CdSe@CdS dot-in-rod nanostructures on the basic exciton relaxation and charge localization processes is closely examined. These systems have been introduced into the field of artificial photosynthesis as potent photosensitizers in assemblies for light driven hydrogen generation. Following photoinduced exciton generation, electrons can be transferred to catalytic reaction centers while holes localize into the CdSe seed, which can prevent charge recombination and lead to the formation of long-lived charge separation in assemblies containing catalytic reaction centers. These processes are in competition with trapping processes of charges at surface defect sites. The density and type of surface defects strongly depend on the type of ligand used. Here we report on a systematic steady-state and time-resolved spectroscopic investigation of the impact of the type of anchoring group (phosphine oxide, thiols, dithiols, amines) and the bulkiness of the ligand (alkyl chains vs. poly(ethylene glycol) (PEG)) to unravel trapping pathways and localization efficiencies. We show that the introduction of the widely used thiol ligands leads to an increase of hole traps at the surface compared to trioctylphosphine oxide (TOPO) capped rods, which prevent hole localization in the CdSe core. On the other hand, steric restrictions, e.g., in dithiolates or with bulky side chains (PEG), decrease the surface coverage, and increase the density of electron trap states, impacting the recombination dynamics at the ns timescale. The amines in poly(ethylene imine) (PEI) on the other hand can saturate and remove surface traps to a wide extent. Implications for catalysis are discussed.

Assessment of Progressive Muscle Relaxation (PMR) as a Stress-Reducing Technique for First-Year Veterinary Students.

The veterinary profession continually strives to address wellness issues such as compassion fatigue, burnout, stress, anxiety, and depression. Wellness issues may begin during the professional curriculum when students experience intense academic, clinical, social, and personal demands on their time. The purpose of this article was to assess the use of progressive muscle relaxation (PMR) as a simple, non-invasive stress reduction technique for first-year veterinary students (n = 101) at a US veterinary college. Students completed a 38-item questionnaire, the Smith Relaxation States Inventory 3 (SRSI3), both before and after performing PMR. Scores for the categories of basic relaxation, mindfulness, positive energy, transcendence, and stress were assessed. Female students (n = 92) had significant (p < .05) improvement in basic relaxation, mindfulness, and stress after completing PMR. Male students (n = 9) had significant (p < .05) improvement in basic relaxation and stress after completing PMR. When grouped according to age, all students had significant (p < .05) improvement in the categories of basic relaxation and stress. Students in the 22-year-old (n = 31), 23-year-old (n = 29), 24-year-old (n = 15), and 25-year-old or greater (n = 17) groups also had significant improvement (p < .05) in mindfulness. Additionally, students in the 23-year-old group had significant (p < .05) improvement in positive energy. These results support the use of PMR as a potential self-care strategy for students to implement during their academic and professional careers.

Retraction Note to: Singular vs. non-singular memorised relaxation for basic relaxation current of the capacitor

We express the basic relaxation current of capacitor dynamics by using convolution operation of memory kernal function (that we choose as singular and non-singular) with rate of change of applied voltage. We have studied singular and non-singular types of memory kernels in this convolution expression. With these, we form constitutive equations for capacitor dynamics. We conclude that, mathematically, we can use the non-singular kernel now although this does not give much useful practically or physically realisable results and interpretations. It may be that we are unable to interpret these constitutive expressions of capacitor relaxation with non-singular memory kernel. Therefore, we have a question: Do natural relaxation dynamics for dielectrics have a singular memory kernel and is the relaxation current function singular in nature? Is the singular relaxation function for capacitor dynamics with singular memory kernel remains the universal law for dielectric relaxation? However, we are not questioning the researchers modelling the relaxation of dielectric via non-singular functions, but we are hinting about the complexity of basic constituent equation of the capacitor dynamics thus obtained by considering non-singular relaxations.