Cold Atomic Collisions: Coherent Control of Penning and Associative Ionization

Coherent Control techniques are computationally applied to cold (1mK < T < 1 K) and ultracold (T < 1 microK) Ne*(3s,3P2) + Ar(1S0) collisions. We show that by using various initial superpositions of the Ne*(3s,3P2) M = {-2,-1,0,1,2} Zeeman sub-levels it is possible to reduce the Penning Ionization (PI) and Associative Ionization (AI) cross sections by as much as four orders of magnitude. It is also possible to drastically change the ratio of these two processes. The results are based on combining, within the "Rotating Atom Approximation", empirical and ab-initio ionization-widths.Comment: 4 pages, 2 tables, 2 figure

Refinamiento del diagrama de clases uml a oracle®9i en atom3

El OMG define el refinamiento como el proceso de transformación desde un modelo independiente de la plataforma de implementación hacia un modelo específico de la plataforma de implementación. Las herramientas CASE convencionales han experimentado problemas con este tipo de transformación, debido a la definición estática de los modelos incluidos en ellas, a las dificultades para la definición de reglas de transformación y al pobre rendimiento mostrado por ellas en la obtención de código. Las herramientas MetaCASE han surgido con nuevas capacidades para mejorar el refinamiento en el contexto de la transformación entre modelos. En este artículo se presenta una implementación en AToM3 para refinamiento que transforma un diagrama de clases UML independiente de la plataforma de implementación a un diagrama de clases UML dependiente de la plataforma de implementación Oracle® 9i. Además, se muestra el uso de esta clase de refinamiento con un caso de estudio

Linear and nonlinear optical absorption coefficients in GaAs/Ga1−xAlxAs concentric double quantum rings : Effects of hydrostatic pressure and aluminum concentration

ABSTRACT: The linear and nonlinear intra-band optical absorption coefficients in GaAs/Ga1−xAlxAs two-dimensional concentric double quantum rings are investigated. Taking into account the combined effects of hydrostatic pressure and aluminum concentration the energies of the ground and the first excited state have been found using the effective mass approximation and the transfer matrix formalism. The energies of these states and the corresponding threshold energy of the intra-band optical transitions are examined as a function of hydrostatic pressure and aluminum concentration for different sizes of the structure. We also investigated the dependencies of the linear, nonlinear, and total optical absorption coefficients as functions of the incident photon energy for different values of hydrostatic pressure, aluminum concentration, sizes of the structure, and incident optical intensity. Its is found that the effects of the hydrostatic pressure and the aluminum concentration lead to a shifting of the resonant peaks of the intra-band optical spectrum

Association between the perceived environment and physical activity among adults in Latin America: a systematic review

BACKGROUND: Activity friendly environments have been identified as promising strategies to increase physical activity levels in the population. Associations between perceived environmental attributes and physical activity in Latin America may vary from those observed in high income countries. The objective of this systematic review is to identify which perceived environmental attributes are associated with physical activity in Latin America. METHODS: Systematic literature search of articles published in English, Portuguese, and Spanish in four databases was conducted (PubMed, Virtual Health Library, EBSCO, and Web of Science). Associations with environmental attributes were analyzed separately for physical activity domains. Fifteen articles were included in the analysis. RESULTS: All studies had cross-sectional designs. The majority of associations were statistically non-significant, and only four associations were found in the unexpected direction. Leisure-time and transport-related physical activity were the domains most frequently included in the studies and had higher number of associations in the expected direction. Leisure-time physical activity showed a convincing association in the expected direction with safety during the day. Transport-related physical activity had a convincing association with presence of street lighting. CONCLUSIONS: This study shows that perceived environmental attributes and their relationship with physical activity appears to be domain, and context specific. In addition, findings from this study show inconsistencies with the information gathered from high-income countries

Transformación del modelo de clases uml a oracle9i® bajo la directiva mda: un caso de estudio

La Arquitectura Orientada a Modelos (MDA) es la propuesta de refinamiento de la OMG orientada a la generación automática de código a partir de los Modelos UML de Sistemas Independientes de la Plataforma de Implementación. En este trabajo se presenta una metodología para transformar el Modelo de Clases UML a un Modelo UML Dependiente de la Plataforma Oracle9i®, siguiendo los lineamientos básicos presentados por esta arquitectura y utilizando a UML como lenguaje de modelado a través de todos los pasos de dicha transformación. Inicialmente las reglas de transformación del Modelo de Clases de UML al Modelo Objeto-Relacional soportado por Oracle9i® son recopiladas en Español y adaptadas a nivel de metamodelo, para lo cual fue necesario elaborar un metamodelo simplificado de la plataforma Oracle9i®. Este conjunto de reglas se hace automatizable al expresarlas en un formalismo lógico, que sea fácilmente ejecutable por una herramienta CASE que soporte un lenguaje formal. Finalmente, se aplican las reglas de refinamiento formalizadas al Modelo de Clases de un Caso Práctico de estudio obteniendo como resultado, un Modelo UML instancia del Metamodelo de la Plataforma Oracle9i®. Los aspectos del Modelo de Clases en los que se hace énfasis en la transformación son las invariantes y reglas de derivación de atributos definidas en el lenguaje formal OCL, así como las relaciones de asociación, composición y generalización entre Clases

Propuesta para el manejo de restricciones en modelos de clases usando atom3

La construcción de los modelos para el desarrollo de software se ha realizado tradicionalmente con herramientas CASE. En estas herramientas los formalismos de cada modelo ya se encuentran plenamente definidos, lo que implica que no es posible agregarles nuevas restricciones. Las herramientas de Metamodelado surgieron como una manera de solución a este problema, pues poseen formalismos propios (generalmente gráficos) que permiten la expresión de diferentes modelos, incluyendo sus restricciones. En este artículo se presenta una propuesta para involucrar restricciones en el modelo de clases de UML empleando para ello el AToM3, una herramienta de metamodelado./Modeling for software development has been traditionally made by CASE tools. In these tools, formalisms for every model are completely defined, which implies it’s not possible adding new restrictions. Meta-modeling tools emerge like a solution for this problem, because they have their own formalisms (generally in graphic environment) allowing different model expressions, including restrictions. In this paper a proposal for involving restrictions in UML class model using AToM3 (a meta-modeling tool) has been presented

Health-related fitness in medical students:a curricular intervention in Bogota, Colombia

Objective: To evaluate the impact of a curricular intervention to promote health-related fitness (HRF) among medical students in Bogota, Colombia.Method: The study was conducted between May 2014 and December 2015 as part of the medical physiology course, in which 208 medical students were enrolled.The curricular intervention included two lectures on physical activity (PA) and student-led group presentations on the physiological effects of exercise on human physiology. An academic incentive (10% of final grade) was given to students who reported and documented regular PA practice during the semester. This study assessed students’ HRF variables, perceptions of the curriculum intervention, and PA practices using quantitative and qualitative approaches.Results: 55% of the students were female, with a mean age of 19.5 years. Body fat, estimated maximum oxygen consumption (VO2max), handgrip, and sit-up strength showed statistically significant improvements at the end of the intervention. Students reported that PA practice was positively influenced by the curriculum intervention, particularly the academic incentive and the HRF tests. Students reported a wide variety of PA practices, which were mainly done with friends, classmates, or family members. Lack of time was the main reported barrier to PA practice.Conclusion: The curricular intervention was effective in improving HRF and promoting PA. It remains to be investigated whether these gains are sustained over time

A study of older adults’ mental health across 33 countries during the covid-19 pandemic

Despite older adults’ extremely high vulnerability to COVID-19 complications and death, few studies have examined how personal characteristics and the COVID-19 pandemic have impacted the mental health of older adults at the global level. The purpose of this study was to examine the relationships among demographics, COVID-19 life impacts, and depression and anxiety in adults aged 60 and older from 33 countries. A sample of 823 older adults aged 60–94 and residing in 33 countries completed a 10-minute online survey following recruitment from mailing lists and social media. Being separated from and having conflicts with loved ones predicted both anxiety and depression, as did residing in a country with higher income. Getting medical treatment for severe symptoms of COVID-19 and having decreased work responsibilities predicted depression, but adjustment to working from home and younger age predicted both depression and anxiety. Participants from Europe and Central Asia reported higher depression than those from all other regions and higher anxiety than those from Latin America and the Caribbean. The COVID-19 pandemic has had serious deleterious effects on the mental health of older adults worldwide. The current findings have direct implications for mental health services that may be delivered to older adults to help facilitate healthy psychological adjustment

Una propuesta para mejorar la completitud de requisitos utilizando un enfoque lingüístico

La calidad de los productos de software está estrechamente relacionada con la calidad de los requisitos especificados desde las primeras etapas del proceso de desarrollo; las propuestas encaminadas a la especificación de requisitos realizan incipientes esfuerzos para lograr que los requisitos del software sean lo suficientemente completos como para lograr la traducción de las necesidades y expectativas de los usuarios al producto final. En este artículo se presenta una propuesta para mejorar la calidad, en cuanto a completitud, de especificaciones de requisitos escritas en un subconjunto del español denominado español restringido, utilizando para ello un enfoque lingüístico basado en la gramática de casos./Software product quality is closely linked with requirements quality from development process initial stages; proposals directed to requirements specification make incipient efforts to reach software requirements complete enough to reach the translation of user needs and expectations into the final product. In this paper we present a proposal for quality enhancement, especially in completeness, of requirements specifications written in restricted Spanish, a subset from Spanish, using a linguistic Case-Grammar- based approach to reach this goal

Estudio comparativo de las herramientas MetaCASE bajo consistencia y refinamiento*

MetaCASE tools have emerged as an evolution of CASE technology, for the overcoming of limitations identified in CASE tools. MetaCASE tools have mechanisms for both creation and modification of metamodeling paradigms, in addition to constraints addition—useful in consistency checking or refinement transformations. In this paper, there was a comparative study done on five MetaCASE tools (AToM3, DOME, GME, MetaEdit+ and UN-MetaCASE), from two points of view: general features and capabilities for consistency checking and refinement transformations. We conclude with some comparative analysis of these tools.Las herramientas MetaCASE surgieron como una evolución de la tecnología CASE, para superar  algunas de las limitaciones identificables en este tipo de tecnologías. Estas herramientas poseen mecanismos que permiten la creación y modificación de paradigmas de metamodelamiento, además de la adición de restricciones que se pueden emplear en chequeos de consistencia o transformaciones de refinamiento. En el artículo que aquí se presenta, se realiza un estudio comparativo de cinco herramientas MetaCASE (AToM3, DOME,  GME, MetaEdit+ y UN-MetaCASE), tomando en cuenta dos puntos de vista: características generales y capacidades para la realización de chequeos de consistencia y transformaciones de refinamiento. El artículo concluye con un análisis comparativo de dichas herramientas