Simple Crossover Research Articles

The combined effect of transcutaneous electrical nerve stimulation and transcutaneous auricular vagus nerve stimulation on pressure and heat pain thresholds in pain-free subjects: a randomized cross-over trial

BackgroundTranscutaneous electrical nerve stimulation (TENS) is a non-invasive modality that utilizes electrical currents to modulate pain in populations with acute and chronic pain. TENS has been demonstrated to produce hypoalgesic effects in postoperative pain, fibromyalgia, knee osteoarthritis, and healthy subjects. Transcutaneous auricular vagus nerve stimulation (TaVNS) is a non-invasive modality that modulates the vagus nerve by stimulating its auricular branches. The effects of the combination of TENS and TaVNS on producing an analgesic response have not been studied. Considering that TENS and TaVNS both stimulate similar analgesic pathways but through different means of activation, we can hypothesize that a combination of both methods can produce a more pronounced analgesic response. Therefore, the objective of this study is to assess the hypoalgesic effect of a combination of TENS and TaVNS in pain-free subjects.Methods/designThe study will be a simple crossover design conducted at the University of Hartford. Subjects will be recruited from the University of Hartford population via oral communication, digital flyers, and posters on campus. Thirty participants will undergo two sessions in a crossover manner with one week in between. During one session, the participants will receive TENS with active TaVNS and the other session will be a placebo procedure (TENS with placebo TaVNS). The order of these sessions will be randomized. Importantly, the pressure pain threshold (PPT) and heat pain threshold (HPT) assessors will be blinded to the treatment category. For active TaVNS, a frequency of 25 Hz will be applied with a pulse duration of 200 µs. For placebo TaVNS, the intensity will be increased to a sensory level and then decreased to 0 mA. High-frequency TENS of 100 Hz will be applied in both sessions, with a pulse duration of 200 µsec, asymmetrical biphasic square waveform, and intensity of maximal tolerance without pain. TENS and TaVNS will be turned on for 30 min after a baseline measurement of outcomes. TENS and TaVNS will then be turned off, but the electrodes will remain on until completion of post-treatment assessment. Pressure pain threshold, heat pain threshold, blood pressure, oxygen saturation, and heart rate will be tested 4 times: Once pre-intervention, once during intervention, once immediately after the intervention, and once 15 min post-intervention. Statistical analysis of the data obtained will consider a significance level of p < 0.05.DiscussionThis study will provide evidence concerning the combined effects of TENS and TaVNS on pain threshold in pain-free participants. Based on the outcomes, a greater understanding of how TENS and TaVNS, when used in conjunction, can modulate pain pathways.Trial registrationClinicalTrials.gov NCT06361381. Registered on 09 April 2024.

Energy-scale considerations of unconventional superconductors—implications to condensation and pairing

Discovery of high-Tc cuprate superconductors (HTSC) in 1986 by Bednorz and Muller, followed by synthesis of A3C60, iron-pnictides/chalcogenides and other exotic superconducting (SC) systems, introduced unconventional superconductors (UCSC) having their mechanisms of condensation and/or pairing distinctly different from those of simpler metals which can be explained by BCS theory. This article will show how one can demonstrate their new mechanisms by examining correlations among key energy-scale parameters, including the transition temperature Tc, the superfluid density ns/m*, the effective Fermi energy εF, the excitation energy of the magnetic resonance mode (MRM), the onset temperatures of Nernst effect and light-induced transient superconductivity, and the spin fluctuation energy scale ℏωsf, and by resorting to analogy / comparisons with superfluid 4He as a representative system undergoing Bose Einstein Condensation (BEC). We will propose a paring mechanism in HTSC based on resonance of spin (ℏωsf) and charge (εF) energy scales, and apply that concept for explaining unusual behaviors in the overdoped region. We will also discuss modifications of a simple BEC-BCS crossover picture to account for actual situations with additional effects of competing order and phase separation.

Hybrid Simulated Annealing: An Efficient Optimization Technique

Genetic Algorithm falls under the category of evolutionary algorithm that follows the principles of natural selection and genetics, where the best adapted individuals in a population are more likely to survive and reproduce, passing on their advantageous traits to their offsprings. Crossover is a crucial operator in genetic algorithms as it allows the genetic material of two or more individuals in the population to combine and create new individuals. Optimizing it can potentially lead to better solutions and faster convergence of the genetic algorithm. The proposed crossover operator gradually changes the alpha value as the search proceeds, similar to the temperature in simulated annealing. The performance of the proposed crossover operator is compared with the simple arithmetic crossover operator. The experiments are conducted using Python and results show that the proposed crossover operator outperforms the simple arithmetic crossover operator. This paper also emphasizes the importance of optimizing genetic operators, particularly crossover operators, to improve the overall performance of genetic algorithms.

Long-term prognostic value of Murray law-based quantitative flow ratio in jailed left circumflex coronary artery after left main crossover stenting

We aimed to evaluate the impact of new Murray law-based QFR of jailed left circumflex coronary artery (LCx) on long-term clinical outcomes after left main coronary artery (LM) simple crossover stenting. 164 patients who underwent LM-to-left anterior descending coronary artery simple crossover stenting and had appropriate angiographic view of LCx for QFR computation were enrolled. The primary clinical outcome was the 5-year target lesion failure (TLF), defined as a composite of cardiac death, a target vessel myocardial infarction or target lesion repeat revascularization. The mean QFR of the LCx after LM stent implantation was 0.88 ± 0.09, and 29 patients (17.7%) had a low QFR (< 0.80), which was significantly associated with a higher 5-year rate of TLF when compared with the high QFR group (27.6% vs. 6.7%; HR: 4.235; 95% CI 1.21–14.95; p = 0.0015). The 5-year LCx ostium-related TLR rate in the low QFR group was also higher (17.2% vs. 3.0% in the high QFR group; HR: 6.07, 95% CI 1.63–22.59, p = 0.002). In a multivariate Cox regression analysis, a low QFR in the LCx after LM stenting was an independent predictor of the 5-year TLF rate (HR: 3.21, 95% CI 1.21–8.53; p = 0.019). ROC analysis showed that QFR a negative predictive value (NPV) of 89.6% ([AUC] 0.73, 95% CI 0.58–0.88, p < 0.05), the cutoff point is 0.85. The patients with a low QFR (< 0.80) in jailed LCX after LM simple crossover stenting had worse 5-year outcomes than those with a high QFR. Conversely, a QFR ≥ 0.85 of jailed LCx could serve as a good predictor of low risk of adverse outcome in LCx ostium. The QFR computation of the jailed LCx may be helpful to determine whether an additional procedure is required for the jailed side branch.

Optimization of inerter system for seismic response control based on a modified genetic algorithm with differential crossover strategy

The damping enhancement effect of the inerter system means that its energy dissipation efficiency can be improved with respect to the traditional dampers. Energy dissipation efficiency have been considered as the optimal design principle of the inerter system, however, the solution for optimized key parameters is difficult because of the special mechanical behavior of the inerter. A modified float-point encoding genetic algorithm is proposed in this study to realize the optimal design of the inerter system with maximized energy dissipation efficiency effectively and robustly. A novel and simple crossover strategy termed differential crossover is proposed and applied in the classical genetic algorithm to optimize the inerter system more effectively. The differential crossover strategy means that a new individual is generated based on the difference between two randomly selected individuals in the population. The mathematical expression for the optimization problem of the inerter system corresponding to the maximum energy dissipation efficiency design principle is established. Following the performance-oriented design concept, performance demand is taken as the constrained condition of the optimization problem. Case design confirms that the modified genetic algorithm can successfully solve the optimization problem of the inerter system and perform a better solving ability over the original genetic algorithms.

Predicting the Plateau Modulus from Molecular Parameters of Conjugated Polymers.

The relationship between Kuhn length lk, Kuhn monomer volume v0, and plateau modulus GN0, initially proposed by Graessley and Edwards for flexible polymers, and extended by Everaers, has a large gap in experimental data between the flexible and stiff regimes. This gap prevents the prediction of mechanical properties from the chain structure for any polymer in this region. Given the chain architecture, including a semiflexible backbone and side chains, conjugated polymers are an ideal class of material to study this crossover region. Using small angle neutron scattering, oscillatory shear rheology, and the freely rotating chain model, we have shown that 12 polymers with aromatic backbones populate a large part of this gap. We also have shown that a few of these polymers exhibit nematic ordering, which lowers GN0. When fully isotropic, these polymers follow a relationship between lk, v0, and GN0, with a simple crossover proposed in terms of the number of Kuhn segments in an entanglement strand Ne.

A note on point estimation and interval estimation of the relative treatment effect under a simple crossover design.

To increase power or reduce the number of patients needed for a parallel groups design, the crossover design has been often used to study treatments for noncurable chronic diseases. However, in the presence of carry-over effect caused by treatments, the commonly-used estimator which ignores the carry-over effect leads to a biased estimator for estimating the treatment effect difference. A two-stage test approach aimed to address carry-over effect proposed was found to be potentially misleading. In this paper, we propose a weighted average of the commonly-used estimator and an unbiased estimator that uses only the first period of the data. We derive an optimal weight that minimizes the mean squared error (MSE) and its modified estimator. We apply Monte Carlo simulation to evaluate the performance of the proposed estimators in a variety of situations. In the simulations, we examine the estimated MSE (EMSE), percentile interval length, and coverage probability calculated from the percentile intervals among considered estimators. Simulation results show that our proposed weighted average estimator and its modified estimator lead to smaller EMSEs on average comparing to the two commonly used estimators. The coverage probabilities using our proposed estimators are reasonably close to the nominal confidence level and the interval lengths are shorter comparing to the use of the unbiased estimator that uses only the first period of the data. We apply an example that was to evaluate the efficacy of two type of bronchodilators for asthma treatment to demonstrate the use of the proposed estimators.

Vaginal stimulation enhances ovulation of queen ovaries treated using a combination of eCG and hCG.

Follicular changes throughout the oestrous phase have been poorly documented in queens because of the location and the small size of ovaries. We investigated follicular development in queens treated with a combination of equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG) and evaluated the effects of vaginal stimulation by a tomcat on ovulation induction. A hormonal treatment was administered using a simple crossover design. Four queens were administered 150 IU of eCG (day 1) and 250 IU of hCG on day 5 and 6. Half of the queens were mated with a vasectomised tomcat for 3 days after hCG injection. Ultrasound imaging of the ovaries clamped at a subcutaneous site was performed once a day from day 1 to 7, and on day 13, and the serum concentrations of oestradiol and progesterone were examined on day 1, 5, 7 and 13. The mean number of follicles gradually increased with the eCG treatment and decreased after hCG injection. The ovulation rate of follicles was significantly higher in the vaginal stimulation group (70.0%) than in the control group (42.6%). During the hormonal treatments, the serum concentration of oestradiol and progesterone did not differ between the two groups. Ultrasound imaging of the ovaries clamped at a subcutaneous site showed that eCG and hCG treatment promoted the follicular growth and corpus luteum formation, respectively. The combination of hCG injection with vaginal stimulation by a vasectomised tomcat enhanced the ovulation rate of follicles.

5-Year Outcome of Simple Crossover Stenting in Coronary Bifurcation Lesions Compared With Side Branch Opening.

The optimal side branch (SB) treatment strategy after simple crossover stenting in bifurcation lesions is still controversial. The purpose of this study was to compare the long-term outcomes of a 1-stent strategy with simple crossover alone versus with an additional SB-opening procedure in patients with left main (LM) and non-LM coronary bifurcation lesions. Patients who underwent percutaneous coronary intervention with a 1-stent strategy for bifurcation lesions including LM were selected from the COBIS (Coronary Bifurcation Stenting) III registry and divided into the simple crossover-alone group and SB-opening group. Clinical outcomes were assessed by the 5-year rate of target lesion failure (a composite of cardiac death, target vessel myocardial infarction, and target lesion repeat revascularization). Among 2,194 patients who underwent the 1-stent strategy, 1,685 (76.8%) patients were treated with simple crossover alone, and 509 (23.2%) patients were treated with an additional SB-opening procedure. Although the baseline SB angiographic disease was more severe in the SB-opening group, the final lumen diameter of the SB was larger. The 5-year observed target lesion failure rate was similar between the 2 groups (7.0% in the simple crossover vs. 6.7% in SB-opening group; hazard ratio: 0.99; 95% confidence interval: 0.66 to 1.48; p=0.947), even in the subgroup analyses including LM (9.5% vs. 11.3%; p=0.442) and true bifurcation (5.3% vs. 7.8%; p=0.362). The results were not changed after an inverse probability of treatment weighting adjustment. There was no difference in the overall and SB-related target lesion revascularization rate in both groups. The long-term clinical outcome of the 1-stent strategy with simple crossover alone for coronary bifurcation lesions was acceptable compared to those of additional SB-opening procedures. (Korean Coronary BifurcationStenting [COBIS] Registry III [COBIS III]; NCT03068494).

Use of unconventional agro-industrial by-products for supplementation of grazing dairy cattle in the Peruvian Amazon region.

The effect of supplementation of grazing cattle with unconventional agro-industrial by-products on milk production and economic performance was evaluated in the Amazon region of Peru. Ten lactating cows were used in a simple crossover design with two periods of 21 days (11 days of adaptation and 10 days of measurements), and two treatments: conventional supplementation (rice polishing) and a mixture of unconventional agro-industrial by-products-MUABP (rice polishing, rice middling, cocoa hull, and coconut meal). Cattle supplemented with MUABP produced more milk than those fed the conventional supplement (10.2 vs. 8.8 kg/cow/day, p <0.001). No differences were found between the two treatments in protein, fat, or lactose content of milk (3.9%, 3.17%, 4.54% on average respectively; p ≥0.05). Daily weight gain with the MUABP treatment was 0.09 kg/day, while with conventional supplementation cow lost -0.04 kg/day (p =0.01). Body condition did not differ between treatments (p ≥0.05). Income due to supplementation with unconventional agro-industrial by-product was US $0.2 in comparison with only rice polishing. Cattle supplemented with MUABP improved milk production and their economic profitability.

EDUCACIÓN DEPORTIVA, ROLES Y VULNERABILIDAD. INFLUENCIA EN LA RESPONSABILIDAD E INTERCULTURALIDAD

El presente estudio examinó los efectos de dos dinámicas de roles (fija y rotativa) sobre los niveles de responsabilidad y competencia intercultural en adolescentes españoles de un contexto socialmente vulnerable. Formaron parte del estudio 96 estudiantes de primer curso de educación secundaria (Medad = 12.2) de un centro ubicado en Andalucía (España). Siguiendo un diseño cruzado simple, cuasi-experimental y con medidas repetidas (pretest-post1-post2), los participantes asistieron a dos unidades didácticas consecutivas con Educación Deportiva sobre baloncesto y floorball, respectivamente. Se recabó información mediante entrevistas semi-estructuradas y cuestionarios. Se evidenció un mayor impacto de los roles fijos en la responsabilidad social y en las variables interculturales (sensibilidad y comportamiento), con especial incidencia en varones. Ligeras consecuencias negativas fueron halladas en los niveles de responsabilidad de estudiantes de sexo femenino. Se desvela la importancia de asumir roles fijos en contextos socialmente vulnerables, así como en experiencias iniciales con Educación Deportiva.

Destructiveness of lexicographic parsimony pressure and alleviation by a concatenation crossover in genetic programming

For theoretical analyses there are two specifics distinguishing GP from many other areas of evolutionary computation: the variable size representations, in particular yielding a possible bloat (i.e. the growth of individuals with redundant parts); and also the role and the realization of crossover, which is particularly central in GP due to the tree-based representation. Whereas some theoretical work on GP has studied the effects of bloat, crossover had surprisingly little share in this work.We analyze a simple crossover operator in combination with randomized local search, where a preference for small solutions minimizes bloat (lexicographic parsimony pressure); we denote the resulting algorithm Concatenation Crossover GP. We consider three variants of the well-studied Majority test function, adding large plateaus in different ways to the fitness landscape and thus giving a test bed for analyzing the interplay of variation operators and bloat control mechanisms in a setting with local optima. We show that the Concatenation Crossover GP can efficiently optimize these test functions, while local search cannot be efficient for all three variants independent of employing bloat control.

Notes on power comparison between the sequential parallel comparison and other commonly-used designs

Because one excludes in the sequential parallel comparison design (SPCD) both placebo responders and patients assigned to the experimental treatment in period 1 from comparison in period 2, test procedures for the SPCD may lose efficiency. Assuming a random effects logistic regression model, we evaluate the loss of efficiency by comparing power of the SPCD with those for the parallel groups design with repeated measurements (PGDRM), simple crossover design (SCD), and parallel group design (PGD). Based on Monte Carlo simulations, we find that the increase in efficiency of the SPCD by use of the PGDRM and SCD can be significant, especially when the variation of responses between patients is large. The SPCD can be, however, of use if the relative treatment effect on placebo non-responders is of our primary interest.

Power and Design Issues in Crossover-Based N-Of-1 Clinical Trials with Fixed Data Collection Periods.

“N-of-1,” or single subject, clinical trials seek to determine if an intervention strategy is more efficacious for an individual than an alternative based on an objective, empirical, and controlled study. The design of such trials is typically rooted in a simple crossover strategy with multiple intervention response evaluation periods. The effect of serial correlation between measurements, the number of evaluation periods, the use of washout periods, heteroscedasticity (i.e., unequal variances among responses to the interventions) and intervention-associated carry-over phenomena on the power of such studies is crucially important for putting the yield and feasibility of N-of-1 trial designs into context. We evaluated the effect of these phenomena on the power of different designs for N-of-1 trials using analytical theory based on standard likelihood principles assuming an autoregressive lag 1, i.e., AR(1), serial correlation structure among the measurements as well as simulation studies. By evaluating the power to detect effects in many different settings, we show that the influence of serial correlation and heteroscedasticity on power can be substantial, but can also be mitigated to some degree through the use of appropriate multiple evaluation periods. We also show that the detection of certain types of carry-over effects can be heavily influenced by design considerations as well.

5-Year Outcomes According to FFR of Left Circumflex Coronary Artery After Left Main Crossover Stenting

ObjectivesThe aim of the current study was to evaluate the long-term clinical impact of fractional flow reserve (FFR) in jailed left circumflex coronary artery (LCx) after left main coronary artery (LM) simple crossover stenting. BackgroundAlthough the provisional side-branch intervention with FFR guidance has been validated for non-LM bifurcation lesions, the outcome of such a strategy in LM bifurcation disease is not well-known. MethodsPatients who underwent LM-to–left anterior descending coronary artery simple crossover stenting and who had FFR measurements in the LCx thereafter were enrolled. A low FFR was defined as ≤0.80. The clinical outcomes were assessed by the 5-year rate of target lesion failure (TLF) (a composite of cardiac death, target-vessel myocardial infarction, or target lesion revascularization). ResultsIn 83 patients, the mean FFR of the LCx after LM stenting was 0.87 ± 0.08, and 14 patients (16.9%) had a low FFR. There was no correlation between the FFR and angiographic % diameter stenosis in jailed LCx (R2 = 0.039; p = 0.071) and there was no difference in the angiographic % diameter stenosis in the high and low FFR groups. At 5 years, the low FFR group had a significantly higher rate of TLF than the high FFR group (33.4% vs. 10.7%; hazard ratio: 4.09, 95% confidence interval: 1.15 to 14.52; p = 0.029). However, there was no difference in the clinical outcomes according to the angiographic % diameter stenosis. In a multivariate analysis, a low FFR was an independent predictor of the risk for a 5-year TLF (hazard ratio: 6.49; 95% confidence interval: 1.37 to 30.73; p = 0.018). ConclusionsThe patients with a high FFR in jailed LCx had better 5-year outcomes than those with a low FFR. The FFR measurement in jailed LCx can be helpful in selecting an adequate treatment strategy and may reduce unnecessary complex procedures.

Star Excursion Balance Test (SEBT): Comparison of Results with and without Neuromuscular Ankle Bandage

Study Design: Prospective study, simple crossover design. Background: Proprioception is a cornerstone for maintaining joint and postural stability. Dynamic stability is particularly emphasized within these components. This feature is important in the rehabilitation field. Therefore, the quest for elements to improve these values ​​can bring advantages in sports. Objectives: Evaluate if there are advantages in the performance of a Star Excursion Balance Test (SEBT) using Kinesio taping. Methods: We evaluated 10 professional soccer players from the Chilean women’s national team. They were randomly divided into 2 groups. One group had Kinesio taping and their SEBT performance was evaluated. The other group performed the measurements without the use of Kinesio Taping. Afterward, each group performed the evaluation they did not do during the first stage. We then compared the performance achieved with and without the use of Kinesio Taping Results: There were significant differences in the performance achieved by the players who had the SEBT bandage applied in comparison to the players that did no. This was confirmed by using the non-parametric Wilcox test for each of the SEBT positions. Conclusions: Kinesio taping has positive implications in the SEBT. We can extrapolate that its use can improve the dynamic balance and thus become an important pillar in sports rehabilitation.

Multi-Objective Optimization to Identify High Quality Clusters with Close Referential Point using Evolutionary Clustering Techniques

Most of the real-world optimization problems have multiple objectives to deal with. Satisfying one objective at a time may lead to the huge deviation in other. This paper uses criterion knowledge ranking algorithm solving multi-objective optimization problems. The aim of this research paper is to solve a multi-objective optimization algorithm with close reference point learning method to identify high quality data clusters. A Simple crossover measure is used to quantify the diversity of the whole set, by considering all patterns as a complete entity. In this paper, the task of identifying high quality data clusters using close reference points is proposed to solve multi-objective optimization problem using evolutionary clustering techniques. The proposed algorithm finds the closest feature from the selected features of the data sets that also minimizes the cost while maintains the quality of the solution by producing better convergence. The resultant clusters were analysed and validated using cluster validity indexes. The proposed algorithm is tested with several UCI real-life data sets. The experimental results substantiates that the algorithm is efficient and robust.

1464Up to 10-year outcome after simple crossover stenting in left main without strut opening over ostial circumflex artery

1464Up to 10-year outcome after simple crossover stenting in left main without strut opening over ostial circumflex artery

Assessment of Noninferiority (and Equivalence) for Simple Crossover Trials Using Bayesian Approach

To assess the noninferiority or equivalence of a general drug to a standard one, researchers generally use the odds ratio of patient response rates to evaluate the relative treatment efficacy. In this paper, we use a logistic random effects model to test noninferiority and equivalence based on the odds ratio of patient response rates for crossover trials with binary data. We use Bayesian sampling algorithm, data augmentation, and scaled mixture of normal representation to implement the approach and improve efficiency. The performance of the proposed approach is assessed via simulation and real data examples.

Dimensional crossover of correlated anion disorder in oxynitride perovskites.

A simple crossover from two-dimensional to three-dimensional correlated disorder of O and N atoms on a cubic lattice has been discovered within the Ba1-xSrxTaO2N series of perovskite oxynitrides. The crossover is driven by lattice expansion as x decreases, and provides a rapid increase in entropy due to a change from subextensive to extensive configurational entropy regimes.