We study in the present paper the response of a flexible macromolecular chain to the application or removal of an electric field. The polymer is mainly modeled as a Gaussian chain, and the case of freely jointed chains is also treated. We consider the dynamics of the chains, after the inception and subsequent cessation of an electric field. In particular, we calculate two properties. One of them is the time-dependent chain expansion, as measured by the components of the gyration tensor, that can be determined by transient electric-field light scattering. The other property is the transient electric birefringence, related to the reorientation of the chain segments. In this way, the dynamics of two different properties can be compared. The transient properties are analyzed in terms of a series of relaxation times. We propose the use of a mean relaxation time as a convenient representation of the rate of the dynamic process, and show that it can be deduced from simulation or experiments with more accuracy than the longest relaxation time. Our computational procedure is based on Brownian dynamics simulation. For Gaussian chains without hydrodynamic interaction, the results are compared with the predictions from the Rouse theory. We evaluate the influence of the strength of the force or field. Simulations are also carried out including hydrodynamic interactions, so that the importance of this effect can be assessed. We propose some combination of relaxation times with other macromolecular properties that take universal numerical values.

The efficient market hypothesis (EMH) affirms that asset prices should reveal all available information. Therefore, it is impossible to "beat the market" always on a risk-adjusted basis since market prices should only respond to new information. Here, we propose a new model to validate the EMH that is inspired on an elastic network model. More specifically, we apply this comparison to Foreign Exchange (FOREX) market under some restrictive conditions. In our hypothesis, several interaction potentials are used to characterize the interaction between banks and each particular quotation. This hypothesis comes from the study of several natural systems, such as macromolecules in solution. An algorithm based on the Monte Carlo methods is also presented in order to predict the evolution of the system.

Background: Immersive 360° video provides consistent demonstrations of clinical procedures. We compared an immersive-video program with conventional simulation, each followed by a common hands-on seminar. Methods: Thirty-two teaching subgroups were randomized 1:1. Of 443 consenting second-year nursing students, 442 were analyzed (222 virtual reality [VR]; 220 control). The four-hour first session addressed urinary, nasogastric and rectal catheterization through faculty demonstrations in 360°, questions, feedback and Plus/Delta debriefing without physical practice in VR, or live demonstration and practice on part-task trainers in control. One week later, both arms attended the same four-hour seminar with theory, practice, a three-station objective structured clinical examination (OSCE) scored independently by two blinded assessors, and a 30-item knowledge test. Knowledge was reassessed four weeks after Session 1. Within the VR arm, an exploratory paired analysis compared satisfaction with previous VR experiences and with the study seminar. Linear models accounted for clustering by teaching subgroup; item-level analyses were exploratory. Results: Mean composite OSCE scores were 87.33 ± 5.05 in the VR arm and 70.70 ± 8.51 in the control arm, on a 0–100 scale. The age- and sex-adjusted difference was 16.65 points (95% CI 14.37–18.94; wild cluster bootstrap, p < 0.001). Performance scores favored VR across all three procedures. Knowledge scores, on a 0–30 scale, were 19.02 ± 2.84 versus 14.12 ± 3.78 immediately after the common seminar and 19.45 ± 2.75 versus 15.21 ± 3.83 four weeks after Session 1. The unadjusted between-arm difference at four weeks was 4.24 points (cluster-robust 95% CI 3.24–5.24). Exploratory item-level analyses favored VR on ten checklist items, whereas material preparation favored control. Within the VR arm, satisfaction with the study seminar was higher than with previous VR experiences. Conclusions: Immersive 360° video with questions and debriefing, followed by hands-on practice, improved simulated procedural performance compared with conventional training. The findings support this blended sequence, not replacement of physical practice or an isolated effect of immersion. Knowledge outcomes require caution because of measurement limitations. Trial Registration: Retrospectively registered on the Open Science Framework on 6 July 2026: 10.17605/OSF.IO/T5JSW.

Background/Objectives: Similarities have been identified between the dependence on psychoactive substances and the patterns of use of cosmetic products. However, there is no specific scale for identifying a substance-related disorders in cosmetic addiction. In this way, the aim of this study was to conduct a preliminary validation of Cosmetic Addiction Scale (CAS) in order to identify signs of addiction to cosmetic products, describing its prevalence and analysing their concordance with a modified version Cut down, Annoyed, Guilty, Eye-opener test (mCAGE). Methods: A cross-sectional study was conducted with sample of 224 university students (80 % women, age range 19-68 years). The mCAGE and the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V) criteria were modified to evaluate participants for a substance-related disorder in cosmetic addiction. Sociodemographic characteristics and cosmetics use were evaluated. Results: Results showed a 16.1 % met modified CAGE criteria, 38 % met modified DSM-V criteria, 7% of serious nature and with differences related by gender, being more prevalent in women. No differences by age were found. A 12.1 % of the subjects were detected as putative addicts in both scales. Results from both instruments were significantly associated (rho = 0.51, p < 0.001). Modified DSM-V criteria obtained a robust validity and intern coherence of 0.77 for the detection of cosmetic addiction. Conclusions: A type of symptomatology involving cosmetic addiction is pointed out. CAS showed as an useful and adequate psychometric tool for detecting cosmetic usage as a type of substance-related disorder.