General approach for dealing with dynamical systems with spatiotemporal periodicities

Dynamical systems often contain oscillatory forces or depend on periodic potentials. Time or space periodicity is reflected in the properties of these systems through a dependence on the parameters of their periodic terms. In this paper we provide a general theoretical framework for dealing with these kinds of systems, regardless of whether they are classical or quantum, stochastic or deterministic, dissipative or nondissipative, linear or nonlinear, etc. In particular, we are able to show that simple symmetry considerations determine, to a large extent, how their properties depend functionally on some of the parameters of the periodic terms. For the sake of illustration, we apply this formalism to find the functional dependence of the expectation value of the momentum of a Bose-Einstein condensate, described by the Gross-Pitaewskii equation, when it is exposed to a sawtooth potential whose amplitude is periodically modulated in time. We show that, by using this formalism, a small set of measurements is enough to obtain the functional form for a wide range of parameters. This can be very helpful when characterizing experimentally the response of systems for which performing measurements is costly or difficult.This work has been supported by through Grants No. MTM2012-36732-C03-03 (R.A.N.), No. FIS2011-24540 (N.R.Q.), and PRODIEVO (J.A.C.), from the Ministerio de Economía y Competitividad (Spain), Grants No. FQM262 (R.A.N.), No. FQM207 (N.R.Q.), and Nos. FQM-7276 and P09-FQM-4643 (N.R.Q., R.A.N.), from the Ministerio de Ciencia e Innovación of Spain, Grant No. FIS2008-02873 (J.C.-P.), from Junta de Andalucía (Spain), and from the Alexander von Humboldt-Stiftung, Germany, through Research Fellowship for Experienced Researchers SPA, Grant No. 1146358 STP (N.R.Q.).Publicad

Kinematic and dynamic array of the alpine deformations in alto Tajo area (Guadalajara)

The geological macrostructure of Alto Tajo is defined by several N1500E dextral strike-slip faults with related secundary structures. The former set of faults together with others N-S sinistral strike-slip faults delimited areas in transtension and transpession. Four tectonic phases have been detected by means of microstructural analysis: N600E compression; N1500E compression (the main deformation phase). N-S compression, without important structures asociated and a last episode of radial extension.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasFALSEpu

Agent organisations: from independent agents to virtual organisations and societies of agents

Real world applications using agent-based solutions can include many agents that needs to communicate and interact with each other in order to meet their objectives. In organisations; Agent open multi-agent systems, problems can include not only the organisation of a large number of agents, but can also be heterogeneous and of unpredictable provenance or behavior. An overview of the alternatives for dealing with these problems is presented, highlighting the way they try to solve or mitigate them. This approach allows the development of complex systems in which there are agents that show very different behaviours and that are able to adapt to unforeseen changes in the environment. This makes it possible to simulate socio-technical or natural environments and observe their possible evolution without the ethical considerations involved in experimenting in real environments.This work has been developed as part of “Virtual-Ledgers-Tecnologías DLT/Blockchain y Cripto-IOT sobre organizaciones virtuales de agentes ligeros y su aplicación en la eficiencia en el transporte de última milla”, ID SA267P18, project financed by Junta Castilla y León, Consejería de Educación, and FEDER funds. It has been partially supported by the European Regional Development Fund (ERDF) through the Interreg Spain-Portugal V-A Program (POCTEP) under grant 0631_DIGITEC_3_E (Smart growth through the specialization of the cross-border business fabric in advanced digital technologies and blockchain.)

A constitutive model for analyzing martensite formation in austenitic steels deforming at high strain rates

This study presents a constitutive model for steels exhibiting SIMT, based on previous sem inal works, and the corresponding methodology to estimate their parameters. The model includes temperature effects in the phase transformation kinetics, and in the softening of each solid phase through the use of a homogenization technique. The model was validated with experimental results of dynamic tensile tests on AISI 304 sheet steel specimens, and their predictions correlate well with the experimental evidence in terms of macroscopic stress strain curves and martensite volume fraction formed at high strain rates. The work shows the value of considering temperature effects in the modeling of metastable austen itic steels submitted to impact conditions. Regarding most of the works reported in the lit erature on SIMT, modeling of the martensitic transformation at high strain rates is the distinctive feature of the present paper.The researchers of the University Carlos III of Madrid are indebted to the Comunidad Autónoma de Madrid (Project CCG10 UC3M/DPI 5596)) and to the Ministerio de Ciencia e Innovación de España (Project DPI/2008 06408) for the financial support received which allowed conducting part of this work. The authors express their thanks to Mr. Philippe and Mr. Tobisch from the company Zwick for the facilities provided to perform the tensile tests at high strain rates.Publicad

Quantum Zeno and anti-Zeno effects in surface diffusion of interacting adsorbates

Surface diffusion of interacting adsorbates is here analyzed within the context of two fundamental phenomena of quantum dynamics, namely the quantum Zeno effect and the anti-Zeno effect. The physical implications of these effects are introduced here in a rather simple and general manner within the framework of non-selective measurements and for two (surface) temperature regimes: high and very low (including zero temperature). The quantum intermediate scattering function describing the adsorbate diffusion process is then evaluated for flat surfaces, since it is fully analytical in this case. Finally, a generalization to corrugated surfaces is also discussed. In this regard, it is found that, considering a Markovian framework and high surface temperatures, the anti-Zeno effect has already been observed, though not recognized as such.Comment: 17 pages, 1 figur

Design and psychometric evaluation of the 'Clinical Communication Self-Efficacy Toolkit'

Nursing students experience difficulties when communicating in clinical practice. Their self-efficacy in clinical communication should be explored as part of their competence assessment before they are exposed to real human interactions in the clinical setting. The aim of this study was to design and psychometrically evaluate a toolkit to comprehensively assess nursing students’ self-efficacy in clinical communication. The study followed an observational cross-sectional design. A sample of 365 nursing students participated in the study. The ‘Clinical Communication Self-Efficacy Toolkit’ (CC-SET) was comprised of three tools: the ‘Patient-Centered Communication Self-efficacy Scale’ (PCC-SES), the ‘Patient clinical Information Exchange and interprofessional communication Self-Efficacy Scale’ (PIE-SES), and the ‘Intrapersonal communication and Self-Reflection Self-Efficacy Scale’ (ISR-SES). The tools’ reliability, validity (content, criterion, and construct) and usability were rigorously tested. The Cronbach’s alpha coefficient of the three tools comprising the CC-SET was very high and demonstrated their excellent reliability (PCC-SES = 0.93; PIE-SES = 0.87; ISR-SES = 0.86). The three tools evidenced to have excellent content validity (scales’ content validity index > 0.95) and very good criterion validity. Construct validity analysis demonstrated that the PCC-SES, PIE-SES, and ISR-SES have a clear and theoretically-congruent structure. The CC-SET is a comprehensive toolkit that allows the assessment of nursing students’ self-efficacy in interpersonal, interprofessional, and intrapersonal communication

Use of serology in a systematic screening programme for strongyloidiasis in an immigrant population

Objectives: The aim of this cross-sectional study was to describe the results of a systematic serological screening programme for strongyloidiasis. Methods: Aprospective serological screeningprogramme for strongyloidiasis wasperformedbetween2009 and2014 for allimmigrantpatients attending theTropicalMedicineUnit. Three formalin-etherconcentrated stool samples and an ELISA for anti-Strongyloides stercoralis antibodies were used as screening tools. Results: Of 659 patients screened, 79 (12%) were positive for S. stercoralis regardless of the diagnostic method used. The prevalence of infection was 42.9% in East African patients, 16.3% in Central African patients,10.9% in those fromSouthAmerica, and 10% in the case ofWestAfrica. Univariate analysis showed thatinfection by S. stercoralis was significantly more frequentinpatients from CentralAfrica (p = 0.026; OR 1.72, 95% CI 1.03–2.85) and East Africa (p<0.001; OR 5.88, 95% CI 1.75–19.32). Taking West Africa as the reference (as the area of lowest prevalence among the positive prevalence areas), the statistical analysis showed that the risk of infection was higher in East Africa (p = 0.001; OR 6.750, 95% CI 2.127–21.423) and Central Africa (p = 0.065; OR 1.747, 95% CI 0.965–3.163). Conclusions: Due to the potential complications of strongyloidiasis infection, we recommend that immigrantpatients fromdevelopingcountriesbe routinelyscreenedfor S. stercoralis, especiallythose from East Africa. A serological test is a highly appropriate screening tool

Psychometric evaluation and cultural adaptation of the Spanish version of the “Scale for End-of Life Caregiving Appraisal”

Objective: To translate, culturally adapt and psychometrically evaluate the Spanish version of the ‘Scale for End-of Life Caregiving Appraisal’ (SEOLCAS). Methods: Observational cross-sectional study. Convenience sample of 201 informal end-of-life caregivers recruited in a southern Spanish hospital. The reliability of the questionnaire was assessed through its internal consistency (Cronbach’s α) and temporal stability (Pearson’s correlation coefficient (r) between test-retest). The content validity index of the items (I-CVI) and the scale (S-CVI/Ave) was calculated. Its criterion validity was explored through performing a linear regression analysis to evaluate the SEOLCAS’ predictive validity. Exploratory factor analysis was used to examine its construct validity. Results: The SEOLCAS’s reliability was very high (Cronbach’s α=0.92). Its content validity was excellent (all items’ content validity index=0.8–1; scale’s validity index=0.88). Evidence of the SEOLCAS’ criterion validity showed that the participants’ scores on the SEOLCAS explained approximately 79.3% of the between-subject variation of their results on the Zarit Burden Interview. Exploratory factor analysis provided evidence of the SEOLCAS’ construct validity. This analysis revealed that two factors (‘internal contingencies’ and ‘external contingencies’) explained 53.77% of the total variance found and reflected the stoic Hispanic attitude towards adversity. Significance of the results: The Spanish version of the ‘Scale for End-of Life Caregiving Appraisal’ has shown to be an easily-applicable, valid, reliable and culturally-appropriate tool to measure the impact of end-of-life care provision on Hispanic informal caregivers. This tool offers healthcare professionals the opportunity to easily explore Hispanic informal end-of-life caregivers’ experiences and discover the type of support they may need (instrumental or emotional) even when there are communicational and organisational constraints

Control de calidad de datos diarios en la Península Ibérica

Ponencia presentada en: VI Congreso Internacional de la Asociación Española de Climatología celebrado en Tarragona del 8 al 11 de octubre de 2008.[ES]La calidad de los datos es un requisito necesario en estudios de variabilidad climática, principalmente cuando se analizan datos de gran resolución espacial y temporal. Para analizar los extremos climáticos es preciso utilizar datos diarios, pero estas series temporales evidencian algunos errores debidos a discontinuidades y otros al azar; por ejemplo, que la precipitación sea menor que cero y que la temperatura máxima sea menor que la mínima para un día determinado. El procedimiento para corregir estos errores resulta muy complicado y hemos adoptado los métodos desarrollados en http://cccma.seos.uvic.ca/ETCCDMI /software.shtml, programados en lenguajes R (RClimDex y RHTest) y Fortran (FClimDex y FHTest). Mostraremos algunos ejemplos aplicados a datos observados “in situ” y compararemos la calidad de estos datos frente a la de los datos de reanálisis del NCEP/NCAR.[EN]Data quality has to be considered in studies about climate variability, especially when data have high spatial and temporal resolutions. The extreme climate research requires daily data which very often have errors due to discontinuities and other random causes, for example, we found some negative precipitation values, and maximum temperature lower than minimum. Therefore, we need to adjust the data to correct these errors. The methods to obtain homogeneous data are complicated. We have addressed the procedure developed in http://cccma.seos.uvic.ca/ETCCDMI/software.shtml, that provides software in R (RClimDex and RHTest) and Fortran (FClimDex and FHTest) languages. In this paper we present some examples about the adjustment technique applied to observed data “in situ” and we compare the quality of the observed against the NCEP/NCAR reanalysis data.Este trabajo ha sido financiado con los proyectos de investigación MEC-CGL2005-06600-CO-01/CLI, de la Junta de Castilla y León SA039/A05, cofinanciados con fondos europeos y con el proyecto de ayudas a la investigación “Memoria D. Samuel Solórzano Barruso” de 2008