A5010196281- Quantum chaos and dynamical systems
- Spectral Theory in Mathematical Physics
- COVID-19 epidemiological studies
- Breastfeeding Practices and Influences
- Respiratory viral infections research
- Quantum Mechanics and Non-Hermitian Physics
- Holomorphic and Operator Theory
- Vaccine Coverage and Hesitancy
- Influenza Virus Research Studies
- COVID-19 Digital Contact Tracing
- Nonlinear Waves and Solitons
- Maternal Mental Health During Pregnancy and Postpartum
- Nonlinear Photonic Systems
- Infant Nutrition and Health
- Nonlinear Dynamics and Pattern Formation
- COVID-19 Impact on Reproduction
- COVID-19 and healthcare impacts
- Vitamin D Research Studies
- Data-Driven Disease Surveillance
- Employment and Welfare Studies
- Engineering and Information Technology
- Advanced Differential Equations and Dynamical Systems
- Child Nutrition and Feeding Issues
- Gender and Feminist Studies
- Quantum many-body systems
Universitat Politècnica de Catalunya
2010-2025
Clínica Girona
2011
Polytechnic University of Puerto Rico
2011
Fundació Lluita contra les Infeccions
2008
Universitat de Barcelona
2003-2005
Abstract Floquet theory provides rigorous foundations for the of periodically driven quantum systems. In case non-periodic driving, however, situation is not so well understood. Here, we provide a critical review theoretical framework developed quasi-periodically Although footing still under development, argue that systems can be treated with generalisations in suitable parameter regimes. Moreover, generalisation Floquet-Magnus expansion and quasi-periodic driving offers promising route simulations.
This paper is concerned with discrete, one-dimensional Schrödinger operators real analytic potentials and one Diophantine frequency.Using localization duality we show that almost every point in the spectrum admits a quasi-periodic Bloch wave if potential smaller than certain constant which does not depend on precise conditions.The associated first-order system, quasiperiodic skew-product, shown to be reducible for all values of energy.This partial nonperturbative generalization reducibility...
Objective: This study analyzes the impact and experiences of hospitalization for any reason on breastfeeding women. Methods: Cross-sectional online survey (November 2019-March 2020). Adults admitted to a Spanish hospital at least one night, when actively breastfeeding, were included. The questionnaire aimed assessing breast complications, support perceived health care workers' attitudes breastfeeding. Results: Of 266 included participants, 70 (26%) stopped during hospitalization, 13 (5%)...
Background Published influenza vaccination coverage in health care workers (HCW) are calculated using two sources: self-report and records. The objective of this study was to determine whether is a good proxy for recorded HCW, as the degree relationship not known, vaccine behaviour influences self-reporting. Methods A cross-sectional conducted self-administered survey during September 2010. Considering record gold standard vaccination, properties (sensitivity, specificity, positive...
We study the existence of strange nonchaotic attractors (SNA) in family Harper maps. prove that for a set parameters positive measure, map possesses SNA. However, is nowhere dense. By changing parameter arbitrarily small amounts, attractor smooth curve and not
In this paper, we study the dynamical properties of a class ergodic linear skew-products which includes defined by quasi-periodic Schrödinger operators and their duals, in Aubry sense, when potential is trigonometric polynomial. Notably, these preserve an adapted complex-symplectic structure. We prove Thouless formula relating sum positive Lyapunov exponents logarithmic associated with density states corresponding operator. particular, for identity upper exponent skew-product dual,...
In this paper we study the existence of analytic families reducible linear quasi-periodic differential equations in matrix Lie algebras. Under suitable conditions show, by means a Kolmogorov–Arnold–Moser (KAM) scheme, that real system close to constant can be modified addition time-free makes it coefficients. If depends analytically on external parameters, then modifying term is also analytic.As major application, prove analyticity resonance tongue boundaries Hill's equation with small...
Influenza vaccination coverage remains low among health care workers (HCWs) in many facilities. This study describes the social network defined by HCWs’ conversations around an influenza campaign order to describe role played behavior and other HCW characteristics configuration of links subjects. used cross-sectional data from 235 HCWs interviewed after 2010/2011 at Hospital Clinic Barcelona (HCB), Spain. The asked: “Who did you talk or share some activity with respect seasonal campaign?”...
During the first peak of COVID-19 pandemic, Preventive Medicine Department and Occupational Health at Hospital Clinic de Barcelona (HCB), a large Spanish referral hospital, developed an innovative comprehensive SARS-CoV2 Surveillance Control System (CoSy-19) in order to preserve patients' health care workers' (HCWs) safety. We aim describe CoSy-19 assess impact number contacts that new cases generated along this time.
SARS-CoV-2 transmission within schools and its contribution to community are still a matter of debate.A retrospective cohort study in all public Catalonia was conducted using publicly available data assessing the association between number reported cases among students staff weeks 1-2 (Sept 14-27th, 2020) academic year with school incidence 4-5. A multilevel Poisson regression model adjusted for corresponding basic health area (BHA) type (primary or secondary), random effects at sanitary...
In the fight against current epidemic of COVID-19, contact tracing has been used with success in China, as part a series containment efforts.1 Historically, data collection done through paper forms and, over time, this digitalized, usually using tools at hand, which are typically spreadsheets and custom-made databases, some cases, specialized software.2 Throughout world, many agents, from regional public health agencies to hospitals all levels, have choose platform record determine...
We present some computer assisted methods to prove the existence of spectral gaps for Almost Mathieu operator at critical coupling and give rigorous numerical estimates on their size. As an example we show that first 8 predicted by Gap Labelling theorem are open when $\omega=(\sqrt{5}-1)/2$ 12 them $\omega=e-2$. A dynamical method based constructive conjugation a hyperbolic cocycle computation eigenvalues finite-dimensional matrices presented. also experiments conjectures gap size associated...
In this paper we use results on reducibility, localization and duality for the Almost Mathieu operator, \[ (H_{b,ϕ} x)_n= x_{n+1} +x_{n-1} + b \cos(2 πn ω+ ϕ)x_n \] $l^2(\mathbb{Z})$ its associated eigenvalue equation to deduce that $b \ne 0,\pm 2$ $ω$ Diophantine spectrum of operator is a Cantor subset real line. This solves so-called ``Ten Martini Problem'' these values $b$ $ω$. Moreover, prove $|b|\ne 0$ small enough or large all spectral gaps predicted by Gap Labelling theorem are open.
Abstract Background WHO recommends measuring the role of social determinants in initiation breastfeeding, given that they will have an impact on health these mothers and babies throughout their lives. The present study, first Spain, describes onset breastfeeding through maternal pregnancy characteristics related to suppression with cabergoline. Methods We assessed 20965 opportunities initiation, collecting data deliveries had obstetric clinic history record resulted at least one alive baby...
Methods This is a cross-sectional study to evaluate the bone mineral density (BMD) in HIV-infected patients from HIV unit of Spanish university hospital. All with at least one evaluation BMD total body, lumbar spine and femoral neck measured by dual-energy X-ray absorptiometry (DEXA) were included analysis. The MannWhitney U test was used compare two populations (normal abnormal mineralization), Kruskal Wallis normal, osteopenia osteoporosis (based on World Health Organization criteria). A...