7,021 research outputs found
Constraints on Weakly Mixed Sterile Neutrinos in the Light of SNO Salt Phase and 766.3 Ty KamLAND Data
The possibility of flavor transitions into sterile neutrinos (accompanying
the dominant LMA transitions) in the solar boron neutrino flux has been
examined in a scenario proposed by Hollanda and Smirnov to overcome some
generic problems of the pure LMA scenario. It is found that the most recent SNO
salt phase solar neutrino data and the KamLAND 766.3 Ty spectral data, allow
for a significant sterile presence in the solar boron neutrino flux reaching
the earth.Comment: 12 pages, 4 figure
Ge growth on ion-irradiated Si self-affine fractal surfaces
We have carried out scanning tunneling microscopy experiments under ultrahigh
vacuum condition to study the morphology of ultrathin Ge films eposited on
pristine Si(100) and ion-irradiated Si(100) self-affine fractal surfaces. The
pristine and the ion-irradiated Si(100) surface have roughness exponents of
alpha=0.19+/-0.05 and alpha=0.82+/-0.04 respectively. These measurements were
carried out on two halves of the same sample where only one half was
ion-irradiated. Following deposition of a thin film of Ge (~6 A) the roughness
exponents change to 0.11+/-0.04 and 0.99+/-0.06, respectively. Upon Ge
deposition, while the roughness increases by more than an order of magnitude on
the pristine surface, a smoothing is observed for the ion-irradiated surface.
For the ion-irradiated surface the correlation length xi increases from 32 nm
to 137 nm upon Ge deposition. Ge grows on Si surfaces in the Stranski-Krastanov
or layer-plus-island mode where islands grow on a wetting layer of about three
atomic layers. On the pristine surface the islands are predominantly of square
or rectangular shape, while on the ion-irradiated surface the islands are
nearly diamond shaped. Changes of adsorption behaviour of deposited atoms
depending on the roughness exponent (or the fractal dimension) of the substrate
surface are discussed.Comment: 5 pages, 2 figures and 1 tabl
Dark Energy and the Statistical Study of the Observed Image Separations of the Multiply Imaged Systems in the CLASS Statistical Sample
The present day observations favour a universe which is flat, accelerated and
composed of matter (baryonic + dark) and of a negative
pressure component, usually referred to as dark energy or quintessence. The
Cosmic Lens All Sky Survey (CLASS), the largest radio-selected galactic mass
scale gravitational lens search project to date, has resulted in the largest
sample suitable for statistical analyses. In the work presented here, we
exploit observed image separations of the multiply imaged lensed radio sources
in the sample. We use two different tests: (1) image separation distribution
function of the lensed radio sources and (2)
{\dtheta}_{\mathrm{pred}} vs {\dtheta}_{\mathrm{obs}} as observational
tools to constrain the cosmological parameters and \Om. The results are
in concordance with the bounds imposed by other cosmological tests.Comment: 20 pages latex; Modified " Results and Discussion " section, new
references adde
Environmental Uncertainty, Business Strategy, and Financial Performance: An Empirical Study of the U.S. Lodging Industry
A key premise in the normative literature is that an appropriate business strategy will favorably align an organization with its environment (Andrews, 1971; Hofer & Schendel, 1978; Porter, 1980). It is argued that the strategy that will produce the best results is dependent on existing environmental circumstances (Miles & Snow, 1978).
This study investigated the tenet that, for firms in the lodging industry, there exists an optimal pattern or ’’fit’’ between the environment and the firm’s business strategy that separates the more successful operations from the less successful ones.
The findings of this study indicate that a match between the state of the environment facing an organization and its business strategy is required for high performance. The results obtained provide an invaluable planning and analysis tool for all levels of management involved in charting a firm’s future
Fine-tuning and naturalness issues in the two-zero neutrino mass textures
In this paper we analyze the compatibility of two-zero neutrino Majorana
textures with the recent experimental data. Differently from previous works, we
use the experimental data to fix the values of the non-vanishing mass matrix
entries and study in detail the correlations and degree of fine-tuning among
them, which is also a measure of how naturally a given texture is able to
describe all neutrino data. This information is then used to expand the
textures in powers of the Cabibbo angle; extracting random O(1) coefficients,
we show that only in few cases such textures reproduce the mixing parameters in
their 3 sigma ranges.Comment: 13 pages, 14 figures. Version to appear in NP
Applying Role Theory in Developing a Framework for the Management of Customer Interactions in Hospitality Businesses
The determinants of consumer satisfaction have long intrigued researchers and practitioners alike. Unfortunately, in the case of service businesses and, in particular, the situation of the actual customer service interaction, little information has been amassed. Rather, the bulk of current knowledge focusing on the service transaction has been accumulated in the domain of operational conformance to standards tied to mechanistic service procedures where the performance evidence is substantial. Thus, the nature and attributes of a positive service experience and the role the service person plays in that experience remains, for the most part, a mystery. This article is an attempt to add to the understanding of the service person’s role and its various dimensions relative to the service interaction. In order to bridge the gap between the provider of the service and the consumer of it, the service person’s instrumental role in consummating the transaction will be examined from a conceptual viewpoint adapted from a sociological perspective on role theory and human interaction, The focus of this effort will be in the application of a behavioral viewpoint to the management of service interactions in the context of hospitality businesses
Spatial multi-criteria decision analysis to predict suitability for African swine fever endemicity in Africa
Background
African swine fever (ASF) is endemic in several countries of Africa and may pose a risk to all pig producing areas on the continent. Official ASF reporting is often rare and there remains limited awareness of the continent-wide distribution of the disease.
In the absence of accurate ASF outbreak data and few quantitative studies on the epidemiology of the disease in Africa, we used spatial multi-criteria decision analysis (MCDA) to derive predictions of the continental distribution of suitability for ASF persistence in domestic pig populations as part of sylvatic or domestic transmission cycles. In order to incorporate the uncertainty in the relative importance of different criteria in defining suitability, we modelled decisions within the MCDA framework using a stochastic approach. The predictive performance of suitability estimates was assessed via a partial ROC analysis using ASF outbreak data reported to the OIE since 2005.
Results
Outputs from the spatial MCDA indicate that large areas of sub-Saharan Africa may be suitable for ASF persistence as part of either domestic or sylvatic transmission cycles. Areas with high suitability for pig to pig transmission (‘domestic cycles’) were estimated to occur throughout sub-Saharan Africa, whilst areas with high suitability for introduction from wildlife reservoirs (‘sylvatic cycles’) were found predominantly in East, Central and Southern Africa. Based on average AUC ratios from the partial ROC analysis, the predictive ability of suitability estimates for domestic cycles alone was considerably higher than suitability estimates for sylvatic cycles alone, or domestic and sylvatic cycles in combination.
Conclusions
This study provides the first standardised estimates of the distribution of suitability for ASF transmission associated with domestic and sylvatic cycles in Africa. We provide further evidence for the utility of knowledge-driven risk mapping in animal health, particularly in data-sparse environments.</p
Band Structure of the Fractional Quantum Hall Effect
The eigenstates of interacting electrons in the fractional quantum Hall phase
typically form fairly well defined bands in the energy space. We show that the
composite fermion theory gives insight into the origin of these bands and
provides an accurate and complete microscopic description of the strongly
correlated many-body states in the low-energy bands. Thus, somewhat like in
Landau's fermi liquid theory, there is a one-to-one correspondence between the
low energy Hilbert space of strongly interacting electrons in the fractinal
quantum Hall regime and that of weakly interacting electrons in the integer
quantum Hall regime.Comment: 10 page
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