8,971 research outputs found
Role of resonances in rho^0 -> pi^+ pi^- gamma
We study the effect of the sigma(600) and a_1(1260) resonances in the rho^0
-> pi^+ pi^- gamma decay, within the meson dominance model. Major effects are
driven by the mass and width parameters of the sigma(600), and the usually
neglected contribution of the a_1(1260), although small by itself, may become
sizable through its interference with pion bremsstrahlung, and the proper
relative sign can favor the central value of the experimental branching ratio.
We present a procedure, using the gauge invariant structure of the resonant
amplitudes, to kinematically enhance the resonant effects in the angular and
energy distribution of the photon. We also elaborate on the coupling constants
involved.Comment: 5 pages, 5 figures, accepted for publication in PR
Planning a Culturally and Linguistically Appropriate Obesity Intervention for Hispanic/Latino Children Living in Rural Nebraska
Childhood obesity is a public health concern in the U.S; however, for the Hispanic/Latino community these concerns have grown to epic proportions. In Nebraska, the rate of childhood obesity is 25.1%; among Hispanic / Latinos students, the obesity rate is 30.9%. Unfortunately, specific Nebraska obesity rates by race and ethnicity are limited among rural communities, and programs that can effectively address this problem in the Hispanic / Latino community are limited or non-existent. Consequently, disparities between urban and rural communities exist. The purpose of this capstone project is to design a culturally and linguistically oriented intervention to address childhood obesity among the Hispanic/Latino community in a rural population. We used secondary data gathered from the literature on evidence-based childhood obesity programs for this population and from focus groups conducted among a Hispanic/Latino community during an APEx Learning project in Colfax County, Nebraska. This capstone project will also provide a full description of the program, logic model, implementation plan, evaluation plan, expected outcomes, strengths and limitations, sustainability, and budget. Finally, this intervention plan hopes to influence community leaders to adopt this project and for it to be implemented by the East Central District Health Department to reduce childhood obesity among the Hispanic/Latino community in Colfax County, Nebraska
Periodic Chaotic Billiards: Quantum-Classical Correspondence in Energy Space
We investigate the properties of eigenstates and local density of states
(LDOS) for a periodic 2D rippled billiard, focusing on their quantum-classical
correspondence in energy representation. To construct the classical
counterparts of LDOS and the structure of eigenstates (SES), the effects of the
boundary are first incorporated (via a canonical transformation) into an
effective potential, rendering the one-particle motion in the 2D rippled
billiard equivalent to that of two-interacting particles in 1D geometry. We
show that classical counterparts of SES and LDOS in the case of strong chaotic
motion reveal quite a good correspondence with the quantum quantities. We also
show that the main features of the SES and LDOS can be explained in terms of
the underlying classical dynamics, in particular of certain periodic orbits. On
the other hand, statistical properties of eigenstates and LDOS turn out to be
different from those prescribed by random matrix theory. We discuss the quantum
effects responsible for the non-ergodic character of the eigenstates and
individual LDOS that seem to be generic for this type of billiards with a large
number of transverse channels.Comment: 13 pages, 18 figure
Aspectos filosóficos de la imagen de Dios en el hombre. Estudio en la obra de Domingo Báñez
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Learning and transfer in hierarchically structured concept attainment tasks.
The research program described in this report was conducted in conjunction with a research project directed by Dr. John A, Emrick. This project was designed to investigate the validity of a test model for individualized instruction and utilized concept learning tasks and examined acquisition trends across levels of conceptual difficulty. The rationale for this test model followed from a detailed examination of decision rule logic in single skill testing. Furthermore, this testing is considered a necessary and essential f eature of nearly all individualized instruction programs. A more detailed account of the specifics of this test model is described by Emrick and Adams (1969) and also by Emrick (1971)
Factores reguladores de la monocigocia y dicigocia en España (2006)
En este trabajo se analiza la influencia de la edad materna, paridad, intervalo intergenési-co, estacionalidad del parto y el ambiente rural/urbano, definido en función del tamaño demográ-fico del lugar de residencia de la madre, sobre las frecuencias de gemelos monocigotos y dicigo-tos que se están produciendo recientemente en España. El estudio se ha realizado a partir de la información demográfica obtenida en la base de datos del Instituto Nacional de EstadÃstica del año 2006. Los resultados indican que la monocigocia (gemelos idénticos) aumenta conforme lo hace la edad materna asà como en los intervalos intergenésicos cortos (periodos entre embarazos consecutivos menores a dos años). Se ha comprobado que las mayores tasas de monocigocia se dan en ambientes rurales y que a partir del quinto embarazo la tasa de monocigocia disminuye mucho. En cuanto a la dicigocia, su frecuencia es mucho mayor en madres primerizas, en interva-los intergenésicos mayores de tres años y medio y en madres con edad avanzada. En primavera es donde se registran menos casos de dicigocia a lo largo del año
Testing the cooling flow model in the intermediate polar EX Hydrae
We use the best available X-ray data from the intermediate polar EX Hydrae to
study the cooling-flow model often applied to interpret the X-ray spectra of
these accreting magnetic white dwarf binaries. First, we resolve a
long-standing discrepancy between the X-ray and optical determinations of the
mass of the white dwarf in EX Hya by applying new models of the inner disk
truncation radius. Our fits to the X-ray spectrum now agree with the white
dwarf mass of 0.79 Msun determined using dynamical methods through
spectroscopic observations of the secondary. We use a simple isobaric cooling
flow model to derive the emission line fluxes, emission measure distribution,
and H-like to He-like line ratios for comparison with the 496 ks Chandra High
Energy Transmission Grating observation of EX Hydrae. We find that the H/He
ratios are not well reproduced by this simple isobaric cooling flow model and
show that while H-like line fluxes can be accurately predicted, fluxes of
lower-Z He-like lines are significantly underestimated. This discrepancy
suggests that some extra heating mechanism plays an important role at the base
of the accretion column, where cooler ions form. We thus explored more complex
cooling models including the change of gravitational potential with height in
the accretion column and a magnetic dipole geometry. None of these
modifications to the standard cooling flow model are able to reproduce the
observed line ratios. While a cooling flow model with subsolar (0.1 )
abundances is able to reproduce the line ratios by reducing the cooling rate at
temperatures lower than K, the predicted line-to-continuum
ratios are much lower than observed. We discuss and discard mechanisms such as
photoionization, departures from constant pressure, resonant scattering,
different electron-ion temperatures, and Compton cooling. [Abridged]Comment: Accepted in Astronomy & Astrophysics, modified version after referee
comments and proof correction
Assessment of Tourism Suitability and Carrying Capacity of Selected Tourist Sites in Tinambac, Camarines Sur, The Philippines
Achieving sustainable tourism requires tourist site management that is based on empirical studies. This paper utilized the analyses of the tourism suitability index and Boullon’s Carrying Capacity Mathematical Model (BCCMM) in assessing four selected tourist sites of Tinambac, Camarines Sur, which offers a wide range of tourist destinations. Results showed that all four sites have the following suitability index and carrying capacity: 76.19% with 43 persons per day; 80.95% with 60 persons per day; 86.90% with 359 persons per day; and 91.67% with 612 persons per day, respectively. Based on the assessment, the four selected tourist sites are suitable for tourism destinations
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