Measurement of the local density spectrum

Since there is still disagreement among the results of various groups, a measurement of the local density spectrum with a close-packed array of four scintillators, each of area 0.14 sq cm was made. Data are taken with conventional electronics, supervised by an on-line microcomputer. The data are stored on audio cassettes and analyzed with the aid of another microcomputer. Since four independent samples for each shower are available, uncertainties inherent in results from many earlier experiments can be minimized

Temperature-dependent Raman scattering of DyScO3 and GdScO3 single crystals

We report a temperature-dependent Raman scattering investigation of DyScO3 and GdScO3 single crystals from room temperature up to 1200 {\deg}C. With increasing temperature, all modes decrease monotonously in wavenumber without anomaly, which attests the absence of a structural phase transition. The high temperature spectral signature and extrapolation of band positions to higher temperatures suggest a decreasing orthorhombic distortion towards the ideal cubic structure. Our study indicates that this orthorhombic-to-cubic phase transition is close to or higher than the melting point of both rare-earth scandates (\approx 2100 {\deg}C), which might exclude the possibility of the experimental observation of such a phase transition before melting. The temperature-dependent shift of Raman phonons is also discussed in the context of thermal expansion

Teach Them How They Learn: Learning Styles and Information Systems Education

The rich, interdisciplinary tradition of learning styles is markedly absent in information systems-related research. The current study applies the framework of learning styles to a common educational component of many of today’s information systems curricula - object-oriented systems development - in an effort to answer the question as to whether one’s learning style, when matched with a specific complementary instructional methodology, results in increased domain-specific performance. The data collected from 196 information systems majors enrolled in object-oriented systems development courses suggest that task performances increases significantly when the instructional methodology closely mirrors the student’s learning style inclination

System and method for confining an object to a region of fluid flow having a stagnation point

A device for confining an object to a region proximate to a fluid flow stagnation point includes one or more inlets for carrying the fluid into the region, one or more outlets for carrying the fluid out of the region, and a controller, in fluidic communication with the inlets and outlets, for adjusting the motion of the fluid to produce a stagnation point in the region, thereby confining the object to the region. Applications include, for example, prolonged observation of the object, manipulation of the object, etc. The device optionally may employ a feedback control mechanism, a sensing apparatus (e.g., for imaging), and a storage medium for storing, and a computer for analyzing and manipulating, data acquired from observing the object. The invention further provides methods of using such a device and system in a number of fields, including biology, chemistry, physics, material science, and medical science

Diffusion of Innovations and the Theory of Planned Behavior in Information Systems Research: A Metaanalysis

Diffusion of Innovations and the Theory of Planned Behavior provide the foundation on which a preponderance of information systems (IS) theory and research is built. IS scholars often assume that the basic factors proffered by these theories are significant determinants of innovation adoption. However, there has yet to be a meta-analytic examination of research in the IS field to validate this assumption. Herein, we use Tornatzky and Klein’s seminal 1982 meta-analysis of innovation characteristics as the starting point for our meta-analytic examination of Diffusion of Innovations and Theory of Planned Behavior models in IS research. In order to focus our investigation on a common criterion variable, adoption propensity, we use antecedents from both models to develop a model of innovation adoption-behavior (IAB). After describing the relationships encompassed by the IAB model, we step through a bare-bones meta-analysis. Considering the data reported in fifty-eight empirical articles, we calculate the estimated true correlations with the criterion variable to be .53 for attitude toward behavior, .33 for subjective norm, .41 for perceived behavioral control, .42 for relative advantage, .43 for compatibility, -.28 for complexity, .32 for trialability, and .38 for observability. With the exception of complexity, all correlations generalize across studies

Experimental evidence of thermal fluctuations on the X-ray absorption near-edge structure at the aluminum K-edge

After a review of temperature-dependent experimental x-ray absorption near-edge structure (XANES) and related theoretical developments, we present the Al K-edge XANES spectra of corundum and beryl for temperature ranging from 300K to 930K. These experimental results provide a first evidence of the role of thermal fluctuation in XANES at the Al K-edge especially in the pre-edge region. The study is carried out by polarized XANES measurements of single crystals. For any orientation of the sample with respect to the x-ray beam, the pre-edge peak grows and shifts to lower energy with temperature. In addition temperature induces modifications in the position and intensities of the main XANES features. First-principles DFT calculations are performed for both compounds. They show that the pre-edge peak originates from forbidden 1s to 3s transitions induced by vibrations. Three existing theoretical models are used to take vibrations into account in the absorption cross section calculations: i) an average of the XANES spectra over the thermal displacements of the absorbing atom around its equilibrium position, ii) a method based on the crude Born-Oppenheimer approximation where only the initial state is averaged over thermal displacements, iii) a convolution of the spectra obtained for the atoms at the equilibrium positions with an approximate phonon spectral function. The theoretical spectra so obtained permit to qualitatively understand the origin of the spectral modifications induced by temperature. However the correct treatment of thermal fluctuation in XANES spectroscopy requires more sophisticated theoretical tools

Assessing the Performance of Recent Density Functionals for Bulk Solids

We assess the performance of recent density functionals for the exchange-correlation energy of a nonmolecular solid, by applying accurate calculations with the GAUSSIAN, BAND, and VASP codes to a test set of 24 solid metals and non-metals. The functionals tested are the modified Perdew-Burke-Ernzerhof generalized gradient approximation (PBEsol GGA), the second-order GGA (SOGGA), and the Armiento-Mattsson 2005 (AM05) GGA. For completeness, we also test more-standard functionals: the local density approximation, the original PBE GGA, and the Tao-Perdew-Staroverov-Scuseria (TPSS) meta-GGA. We find that the recent density functionals for solids reach a high accuracy for bulk properties (lattice constant and bulk modulus). For the cohesive energy, PBE is better than PBEsol overall, as expected, but PBEsol is actually better for the alkali metals and alkali halides. For fair comparison of calculated and experimental results, we consider the zero-point phonon and finite-temperature effects ignored by many workers. We show how Gaussian basis sets and inaccurate experimental reference data may affect the rating of the quality of the functionals. The results show that PBEsol and AM05 perform somewhat differently from each other for alkali metal, alkaline earth metal and alkali halide crystals (where the maximum value of the reduced density gradient is about 2), but perform very similarly for most of the other solids (where it is often about 1). Our explanation for this is consistent with the importance of exchange-correlation nonlocality in regions of core-valence overlap.Comment: 32 pages, single pdf fil

Uncovering Research Opportunities in the Medical Informatics Field: A Quantitative Content Analysis

With rapid improvements in technology, the ever-pressing need to reduce healthcare costs, and continuing legislation emphasizing medical reforms, the demand for research within the healthcare/information systems interface is growing. In this study, we ascertain the prevalent themes from the extant medical informatics literature in an effort to motivate research beyond the traditional domain of health information technology research so information systems scholars can better understand where their expertise might contribute to advancements in healthcare. We used a quantitative content analysis method to systematically explore 2,188 article texts from journals in medical informatics, medicine, and MIS published over a ten-year period. Texts were analyzed using centering resonance analysis and factor analysis and the following themes emerged from the literature: Analytics; Healthcare Operations and Standards (with sub-themes: Operations, Project Management, and Information Assurance); Knowledge Transfer/Communication (with sub-themes: Extending beyond the Organization, Internal to the Organization, and Patient-Provider); Perceptions and Managing Expectations of Information Technology; Advancements in Research; and Software as a Service. In this article, we discuss these themes in greater detail and offer directions for future research

Diminished Antioxidant Activity of High-Density Lipoprotein–Associated Proteins in Systolic Heart Failure

Background— Diminished serum arylesterase activity, catalyzed by the high-density lipoprotein–associated paraoxonase-1, is associated with heightened systemic oxidative stress and atherosclerosis risk. In the present study, we sought to determine the prognostic role of serum arylesterase activity in subjects with systolic heart failure, particularly in relation to established cardiac biomarkers. Methods and Results— We measured serum arylesterase activity in 760 subjects with impaired left ventricular systolic function (left ventricular ejection fraction \u3c50%), and prospectively followed major adverse cardiac events (including death, nonfatal myocardial infarction, and stroke) for 3 years. In our study cohort (mean age, 64±11 years; 74% men; median left ventricular ejection fraction, 35%; median creatinine clearance, 96 mg/dL), mean serum arylesterase activity (98±25 μmol/L/min/mL) was lower compared with that in healthy control subjects (mean, 115±26 μmol/L/min/mL, P\u3c0.01) but higher compared with advanced decompensated heart failure subjects (mean, 69±22 μmol/L/min/mL, P\u3c0.01). Within our cohort, there was modest correlation between serum arylesterase activity and high-density lipoprotein cholesterol (r=0.33, P\u3c0.01) as well as B-type natriuretic peptide (r=−0.23, P\u3c0.01). Lower serum arylesterase activity was a strong predictor of poorer outcomes (hazard ratio, 2.94; 95% confidence interval, 1.54, 5.62; P\u3c0.001). After adjusting for traditional risk factors, medication use, B-type natriuretic peptide, and creatinine clearance, lower serum arylesterase still conferred an increased risk of major adverse cardiac events at 3 years (hazard ratio, 2.69; 95% confidence interval, 1.37 to 5.28; P=0.004). Conclusions— In patients with systolic heart failure, decreased serum arylesterase activity, a measure of diminished antioxidant properties of high-density lipoprotein, predicts higher risk of incident long-term adverse cardiac event independent of established clinical and biochemical risk factors