Non-periodic driving of coupled oscillators:a spherical swing

Nonlinearly coupled, damped oscillators at 1:1 frequency ratio, one oscillator being driven coherently for efficient excitation, are exemplified by a spherical swing with some phase-mismatch between drive and response. For certain damping range, excitation is found to succeed if it lags behind, but to produce a chaotic attractor if it leads the response. Although a period-doubhng sequence, for damping increasing, leads to the attractor, this is actually born as a hard (as regards amplitude) bifurcation at a zero growth-rate parametric line; as damping decreases, an unstable fixed point crosses an invariant plane to enter as saddle-focus a phase-space domain of physical solutions. A second hard bifurcation occurs at the zero mismatch line, the saddle-focus leaving that domain. Times on the attractor diverge when approaching either fine, leading to exactly one-dimensional and noninvertible limit maps, which are analytically determined

Under-reporting bicycle accidents to police in the COST TU1101 international survey: Cross-country comparisons and associated factors

Police crash reports are often the main source for official data in many countries. However, with the exception of fatal crashes, crashes are often underreported in a biased manner. Consequently, the countermeasures adopted according to them may be inefficient. In the case of bicycle crashes, this bias is most acute and it probably varies across countries, with some of them being more prone to reporting accidents to police than others. Assessing if this bias occurs and the size of it can be of great importance for evaluating the risks associated with bicycling. This study utilized data collected in the COST TU1101 action “Towards safer bicycling through optimization of bicycle helmets and usage”. The data came from an online survey that included questions related to bicyclists' attitudes, behaviour, cycling habits, accidents, and patterns of use of helmets. The survey was filled by 8655 bicyclists from 30 different countries. After applying various exclusion factors, 7015 questionnaires filled by adult cyclists from 17 countries, each with at least 100 valid responses, remained in our sample. The results showed that across all countries, an average of only 10% of all crashes were reported to the police, with a wide range among countries: from a minimum of 0.0% (Israel) and 2.6% (Croatia) to a maximum of a 35.0% (Germany). Some factors associated with the reporting levels were type of crash, type of vehicle involved, and injury severity. No relation was found between the likelihood of reporting and the cyclist's gender, age, educational level, marital status, being a parent, use of helmet, and type of bicycle. The significant under-reporting – including injury crashes that do not lead to hospitalization – justifies the use of self-report survey data for assessment of bicycling crash patterns as they relate to (1) crash risk issues such as location, infrastructure, cyclists' characteristics, and use of helmet and (2) strategic approaches to bicycle crash prevention and injury reduction.Fil: Shinar, D.. Ben Gurion University of the Negev; IsraelFil: Valero Mora, Pedro. Universidad de Valencia; EspañaFil: van Strijp Houtenbos, M.. Institute For Road Safety Research; Países BajosFil: Haworth, N.. Queensland University of Technology; AustraliaFil: Schramm, A.. Queensland University of Technology; AustraliaFil: de Bruyne, G.. Universiteit Antwerp; BélgicaFil: Cavallo, V.. No especifíca;Fil: Chliaoutakis, J.. No especifíca;Fil: Pereira Dias, Joao. Instituto Superior Tecnico; PortugalFil: Ferraro, Ottavia Eleonora. Universita Degli Studi Di Pavia; ItaliaFil: Fyhri, Aslak. No especifíca;Fil: Sajatovic, Anika Hursa. No especifíca;Fil: Kuklane, Kalev. Lund University; SueciaFil: Ledesma, Ruben Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Psicología Básica, Aplicada y Tecnología. Universidad Nacional de Mar del Plata. Facultad de Psicología. Instituto de Psicología Básica, Aplicada y Tecnología.; ArgentinaFil: Calvé Mascarell, Oscar. Ben Gurion University of the Negev; IsraelFil: Morandi, A.. Universita Degli Studi Di Pavia; ItaliaFil: Muser, Markus. No especifíca;Fil: Otte, Diettmar. No especifíca;Fil: Papadakaki, M.. No especifíca;Fil: Sanmartín, J.. Universidad de Valencia; EspañaFil: Dulf, D.. No especifíca;Fil: Saplioglu, M.. No especifíca;Fil: Tzamalouka, Georgia. No especifíca

Bioactive bilayered dressing for compromised epidermal tissue regeneration with sequential activity of complementary agents

The article deals with the design, preparation, and evaluation of a new bilayered dressing for application in the healing of compromised wounds. The system is based on the sequential release of two complementary bioactive components to enhance the activation of the regeneration of dermal tissue. The internal layer is a highly hydrophilic and biodegradable film of gelatin and hyaluronic acid (HG), crosslinked with the natural compound genipin, which reacts with the amine groups of gelatin. This film is loaded with the proangiogenic, anti-inflammatory, and antibacterial peptide, proadrenomedullin N-terminal 20 peptide (PAMP), that is released slowly in the wound site. The external layer, more stable and less hydrophilic, is constituted by a biodegradable polyurethane derived from poly(caprolactone) and pluronic L61. This layer is loaded with resorbable nanoparticles of bemiparin (a fractionated low molecular weight heparin), which promotes the activation of growth factors, FGF and VEGF, and provides a good biomechanical stability and controlled permeability of the bilayered dressing. Experiments carried out in mice demonstrate the excellent angiogenic effect of the HG film in the dermal tissue. Application of the bilayered dressing in the wound healing rabbit ear model shows an improved cicatrization of the wound in both ischemic and non-ischemic defects, favoring epithelialization and reducing noticeably the contraction and the inflammation.This work was supported by the CIBER-BBN and a Grant from Spain’s Ministry of Science and Education (SAF2009-13240-C02-01).Peer Reviewe

Multiple-length-scale elastic instability mimics parametric resonance of nonlinear oscillators

Spatially confined rigid membranes reorganize their morphology in response to the imposed constraints. A crumpled elastic sheet presents a complex pattern of random folds focusing the deformation energy while compressing a membrane resting on a soft foundation creates a regular pattern of sinusoidal wrinkles with a broad distribution of energy. Here, we study the energy distribution for highly confined membranes and show the emergence of a new morphological instability triggered by a period-doubling bifurcation. A periodic self-organized focalization of the deformation energy is observed provided an up-down symmetry breaking, induced by the intrinsic nonlinearity of the elasticity equations, occurs. The physical model, exhibiting an analogy with parametric resonance in nonlinear oscillator, is a new theoretical toolkit to understand the morphology of various confined systems, such as coated materials or living tissues, e.g., wrinkled skin, internal structure of lungs, internal elastica of an artery, brain convolutions or formation of fingerprints. Moreover, it opens the way to new kind of microfabrication design of multiperiodic or chaotic (aperiodic) surface topography via self-organization.Comment: Submitted for publicatio

Extended parametric resonances in nonlinear Schrodinger systems

We study an example of exact parametric resonance in a extended system ruled by nonlinear partial differential equations of nonlinear Schr\"odinger type. It is also conjectured how related models not exactly solvable should behave in the same way. The results have applicability in recent experiments in Bose-Einstein condensation and to classical problems in Nonlinear Optics.Comment: 1 figur

Diverse tick-borne microorganisms identified in free-living ungulates in Slovakia

Background: Free-living ungulates are hosts of ixodid ticks and reservoirs of tick-borne microorganisms in central Europe and many regions around the world. Tissue samples and engorged ticks were obtained from roe deer, red deer, fallow deer, mouflon, and wild boar hunted in deciduous forests of south-western Slovakia. DNA isolated from these samples was screened for the presence of tick-borne microorganisms by PCR-based methods. Results: Ticks were found to infest all examined ungulate species. The principal infesting tick was Ixodes ricinus, identified on 90.4% of wildlife, and included all developmental stages. Larvae and nymphs of Haemaphysalis concinna were feeding on 9.6% of wildlife. Two specimens of Dermacentor reticulatus were also identified. Ungulates were positive for A. phagocytophilum and Theileria spp. Anaplasma phagocytophilum was found to infect 96.1% of cervids, 88.9% of mouflon, and 28.2% of wild boar, whereas Theileria spp. was detected only in cervids (94.6%). Importantly, a high rate of cervids (89%) showed mixed infections with both these microorganisms. In addition to A. phagocytophilum and Theileria spp., Rickettsia helvetica, R. monacensis, unidentified Rickettsia sp., Coxiella burnetii, "Candidatus Neoehrlichia mikurensis", Borrelia burgdorferi (s.l.) and Babesia venatorum were identified in engorged I. ricinus. Furthermore, A. phagocytophilum, Babesia spp. and Theileria spp. were detected in engorged H. concinna. Analysis of 16S rRNA and groEL gene sequences revealed the presence of five and two A. phagocytophilum variants, respectively, among which sequences identified in wild boar showed identity to the sequence of the causative agent of human granulocytic anaplasmosis (HGA). Phylogenetic analysis of Theileria 18S rRNA gene sequences amplified from cervids and engorged I. ricinus ticks segregated jointly with sequences of T. capreoli isolates into a moderately supported monophyletic clade. Conclusions: The findings indicate that free-living ungulates are reservoirs for A. phagocytophilum and Theileria spp. and engorged ixodid ticks attached to ungulates are good sentinels for the presence of agents of public and veterinary concern. Further analyses of the A. phagocytophilum genetic variants and Theileria species and their associations with vector ticks and free-living ungulates are required.Fil: Kazimírová, Mária. Slovak Academy of Sciences. Institute of Zoology; EslovaquiaFil: Hamšíková, Zuzana. Slovak Academy of Sciences. Institute of Zoology; EslovaquiaFil: Spitalská, Eva. Slovak Academy of Sciences. Institute of Virology. Biomedical Research Center,; EslovaquiaFil: Minichová, Lenka. Slovak Academy of Sciences. Institute of Virology. Biomedical Research Center,; EslovaquiaFil: Mahríková, Lenka. Slovak Academy of Sciences. Institute of Zoology; EslovaquiaFil: Caban, Radoslav. Široká ; EslovaquiaFil: Sprong, Hein. National Institute for Public Health and Environment.Laboratory for Zoonoses and Environmental Microbiology; Países BajosFil: Fonville, Manoj. National Institute for Public Health and Environment.Laboratory for Zoonoses and Environmental Microbiology; Países BajosFil: Schnittger, Leonhard. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Patobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Kocianová, Elena. Slovak Academy of Sciences. Institute of Virology. Biomedical Research Center,; Eslovaqui

Varespladib and cardiovascular events in patients with an acute coronary syndrome: the VISTA-16 randomized clinical trial

IMPORTANCE: Secretory phospholipase A2(sPLA2) generates bioactive phospholipid products implicated in atherosclerosis. The sPLA2inhibitor varespladib has favorable effects on lipid and inflammatory markers; however, its effect on cardiovascular outcomes is unknown. OBJECTIVE: To determine the effects of sPLA2inhibition with varespladib on cardiovascular outcomes. DESIGN, SETTING, AND PARTICIPANTS: A double-blind, randomized, multicenter trial at 362 academic and community hospitals in Europe, Australia, New Zealand, India, and North America of 5145 patients randomized within 96 hours of presentation of an acute coronary syndrome (ACS) to either varespladib (n = 2572) or placebo (n = 2573) with enrollment between June 1, 2010, and March 7, 2012 (study termination on March 9, 2012). INTERVENTIONS: Participants were randomized to receive varespladib (500 mg) or placebo daily for 16 weeks, in addition to atorvastatin and other established therapies. MAIN OUTCOMES AND MEASURES: The primary efficacy measurewas a composite of cardiovascular mortality, nonfatal myocardial infarction (MI), nonfatal stroke, or unstable angina with evidence of ischemia requiring hospitalization at 16 weeks. Six-month survival status was also evaluated. RESULTS: At a prespecified interim analysis, including 212 primary end point events, the independent data and safety monitoring board recommended termination of the trial for futility and possible harm. The primary end point occurred in 136 patients (6.1%) treated with varespladib compared with 109 patients (5.1%) treated with placebo (hazard ratio [HR], 1.25; 95%CI, 0.97-1.61; log-rank P = .08). Varespladib was associated with a greater risk of MI (78 [3.4%] vs 47 [2.2%]; HR, 1.66; 95%CI, 1.16-2.39; log-rank P = .005). The composite secondary end point of cardiovascular mortality, MI, and stroke was observed in 107 patients (4.6%) in the varespladib group and 79 patients (3.8%) in the placebo group (HR, 1.36; 95% CI, 1.02-1.82; P = .04). CONCLUSIONS AND RELEVANCE: In patients with recent ACS, varespladib did not reduce the risk of recurrent cardiovascular events and significantly increased the risk of MI. The sPLA2inhibition with varespladib may be harmful and is not a useful strategy to reduce adverse cardiovascular outcomes after ACS. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01130246. Copyright 2014 American Medical Association. All rights reserved

Assessment of preparedness and proficiency in basic and advanced life support among nursing professionals: a cross-sectional study

BackgroundCardiac diseases are among the leading causes of death worldwide, including sudden cardiac arrest in particular. Nursing professionals are often the first to encounter these scenarios in various settings. Adequate preparation and competent knowledge among nurses significantly impact survival rates positively.AimTo describe the state of knowledge about Basic and Advanced Life Support guidelines among Ecuadorian nursing professionals.MethodologyA nationwide, descriptive, cross-sectional study was conducted from February to April 2023 among Ecuadorian nursing professionals. Participants were invited through official social media groups such as WhatsApp and Facebook. The study utilized a self-administered online questionnaire to evaluate theoretical knowledge of Basic Life Support (BLS) and Advanced Life Support (ALS). Knowledge scores were assigned based on the number of correct answers on the tests. T-tests and one-way ANOVA were used to examine relationships between knowledge scores and demographic and academic training variables.ResultsA total of 217 nursing professionals participated in the study. The majority of the participants were female (77.4%) and held a university degree (79.9%). Among them, only 44.7% claimed to have obtained a BLS training certificate at least once, and 19.4% had ALS certification. The overall BLS knowledge score (4.8/10 ± 1.8 points) was higher than the ALS score (4.3/10 ± 1.8 points). Participants who had obtained BLS certification and those who used evidence-based summaries as a source of extracurricular training achieved higher BLS and ALS knowledge scores.ConclusionEcuadorian nursing professionals in this study exhibited a significant deficiency in theoretical knowledge of BLS and ALS. Formal training and preparation positively impact life support knowledge. Support and inclusion of Ecuadorian nurses in training and academic preparation programs beginning at the undergraduate level are essential for promoting life support knowledge and improving outcomes