Dimensions of acculturation: Associations with health risk behaviors among college students from immigrant families.

In the present study, we examined a bidimensional model of acculturation (which includes both heritage and U.S. practices, values, and identifications) in relation to hazardous alcohol use, illicit drug use, unsafe sexual behavior, and impaired driving. A sample of 3,251 first- and second-generation immigrant students from 30 U.S. colleges and universities completed measures of behavioral acculturation; cultural values (individualism, collectivism, and self-construal); ethnic and U.S. identity; and patterns of alcohol and drug use, engagement in potentially unsafe sexual activities, and driving while (or riding with a driver who was) intoxicated. Results indicate that heritage practices and collectivist values were generally protective against health risk behaviors, with collectivist values most strongly and consistently protective. Nonetheless, heritage identifications were positively associated with sexual risk taking for Hispanics. U.S. practices, values, and identifications were not consistently related to risk behavior participation. Results are discussed in terms of bidimensional approaches to acculturation, the immigrant paradox, and implications for counseling practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Efficient search strategy in structural analysis for handwritten mathematical expression recognition

Problems with local ambiguities in handwritten mathematical expressions (MEs) are often resolved at global level. Therefore, keeping local ambiguities is desirable for high accuracy, with a hope that they may be resolved by later global analyses. We propose a layered search framework for handwritten ME recognition. From given handwritten input strokes, ME structures are expanded by adding symbol hypotheses one by one, representing ambiguities of symbol identities and spatial relationships as numbers of branches in the expansion. We also propose a novel heuristic predicting how likely the set of remaining input strokes forms valid spatial relationships with the current partially interpreted structure. Further complexity reduction is achieved by delaying the symbol identity decision. The elegance of our approach is that the search result would be unchanged even if we prune out unpromising branches of the search. Therefore, we can examine a much larger number of local hypotheses with a limited amount of computing resource in making global level decisions. The experimental evaluation shows promising results of the efficiency of the proposed approach and the performance of our system, which results from the system's capacity to examine a large number of possibilities.     

Crystallization behavior and microwave dielectric characteristics of ZnO-(La, Nd)2O3-B2O3-based dielectrics

Crystallizable zinc borate glasses modified with different contents of La₂O₃ or Nd₂O₃ were investigated as a potential low loss dielectric with respect to their crystallization behavior and microwave dielectric characteristics. The glasses were admixed with Al₂O₃ filler and fired at 850°C for 30 min in air to prepare low temperature dielectrics. Crystallization behavior and microwave dielectric properties of the resulting samples strongly depended on the relative content of La₂O₃ or Nd₂O₃ in the glass. As a promising result, the composition of 0.15ZnO-0.25Nd₂O₃-0.6B₂O₃ exhibited k?～?6.5 and Q?～?1194 at the resonant frequency of 18.9 GHz. Near zero temperature coefficient of frequency (TCF) was obtained by additional modification of the composition with ～10 wt.% of TiO₂ filler. Crystallization kinetics of the samples was studied based on the differential thermal analysis (DTA) curves obtained with different heating rates. Correlation of the observed dielectric properties to the crystallization behavior is the main subject of this work.     

Evaluation and prediction of the forming limit of AZ31B magnesium alloy sheets in a cross-shaped cup deep drawing process

In this study, the formability of AZ31B magnesium alloy sheets was investigated through experimental and numerical approaches. Tensile tests and limit dome height tests were carried out at several temperatures between 25 °C and 300 °C to obtain the mechanical properties and forming limit diagram (FLD). The interfacial heat transfer coefficient between two adjacent tools, and the convection coefficient were estimated by comparing the tool temperatures obtained from trial heat transfer analyses with actual measured data. The FLD-based criterion considering the strain path and the blank temperature was used to predict by finite element analysis (FEA) the forming limit in a cross-shaped cup deep drawing process. A comparison of the FEA and experimental data showed that this criterion was very useful and reasonable. In particular, the temperature of each forming tool that provided the best formability of AZ31 sheets was determined by coupled temperature-deformation analyses. A practical method that can greatly reduce the forming time by increasing the punch speed during the forming process was suggested.     

Stability analysis of a diode-pumped,thermal birefringence-compensated two-rod Nd:YAG laser with 770-W output power

Using a ray matrix method, we analyze theoretically how the r and theta polarizations affect the resonator stability condition of two laser heads with or without thermal birefringence compensation. The resonator stability condition is analyzed graphically for a plane-parallel and a concave-concave resonator. The maximum range of stable region is found for both the short and the long cavity. The characteristics of the laser output power are confirmed experimentally in association with the resonator stability condition. The laser output power of 776 W is obtained with the optical-to-optical efficiency of 45% for a plane-parallel resonator with a short crystal separation.     

Output power and polarization characteristics for a diode-side-pumped Nd:YAG rod laser with a diffusive optical pump cavity

We fabricated and analyzed the output power and polarization characteristics of an efficient diode-side-pumped Nd:YAG rod laser with a diffusive optical cavity. The resonator stability conditions are analyzed graphically in the symmetric and asymmetric configurations for a plane-parallel resonator. On the basis of an analysis of the stability condition and mode size for the r and theta polarizations, we clarify how the stable laser operation is possible for various resonator configurations. In particular, we show that the critical stability region of around g1*g2* = 0 provides a stable resonator in the symmetric resonator, even with a slight asymmetry. Experimentally, the output power and polarization characteristics are confirmed in association with the resonator stability condition.     

Diagnosis of venous thrombosis in the legs using 81Krm venography

Contrast venography, the accepted gold standard for the diagnosis of venous thrombosis of the leg, is a painful and invasive procedure with late side effects. There is controversy in literature reports about the sensitivity of 99Tcm-macroaggregated albumin (MAA) phlebography: indeed, using 99Tcm-MAA, poor results are obtained when one has to detect calf vein thrombosis. As with other isotopic procedures requiring a pedal injection of the tracer, the use of an injectable solution of 81Krm is a nonspecific method, based upon the abnormality in flow in the deep venous system which results from a deep venous thrombosis. However, when compared with 99Tcm-MAA, 81Krm offers theoretical advantages for phlebographic studies of the lower limbs. In this work 24 patients were studied both with contrast phlebography and with 81Krm. Although 81Krm provided images of high quality, there was a lack of sensitivity below the knee, where false negative results were observed. This could be explained by the fact that the radionuclide venographic procedures usually visualize only one or, in some cases, two of the three deep veins of the calf. Moreover, accurate differentiation between superficial and deep veins in the calf often appears difficult, even using a tourniquet.     

Systematization of the mass spectra for speciation of inorganic salts with static secondary ion mass spectrometry

The analytical use of mass spectra from static secondary ion mass spectrometry for the molecular identification of inorganic analytes in real life surface layers and microobjects requires an empirical insight in the signals to be expected from a given compound. A comprehensive database comprising over 50 salts has been assembled to complement prior data on oxides. The present study allows the systematic trends in the relationship between the detected signals and molecular composition of the analyte to be delineated. The mass spectra provide diagnostic information by means of atomic ions, structural fragments, molecular ions, and adduct ions of the analyte neutrals. The prediction of mass spectra from a given analyte must account for the charge state of the ions in the salt, the formation of oxide-type neutrals from oxy salts, and the occurrence of oxidation-reduction processes.