Crossing the distance: Adjustment of Taiwanese graduate students in the United States.

Using qualitative and quantitative methodologies across 3 samples, the authors investigated the cross-cultural adjustment of Taiwanese students attending graduate school in the United States. First, interviews with 25 Taiwanese students regarding their experiences in the United States revealed themes of language barriers, confidence about speaking English, social contact with Taiwanese and Americans, and cultural differences, which included the importance of being independent. Second, the results of a quantitative study (n=67) generally supported the hypotheses that communication apprehension and social contact predicted adaptation, whereas actual English ability did not, and that Taiwanese students identified being independent as important to their functioning in the United States. Third, a focus group with 4 graduate students provided a richer conceptualization of the interactions among the constructs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Meningovertebral ligaments and their putative significance in low back pain

OBJECTIVE: To determine the presence and morphology of the meningovertebral ligaments (ligaments of Hofmann) as well as postulate their possible contribution to low back pain. DESIGN: Sagittal dissections were performed on 12 embalmed cadaver specimens including the L5/S1 intervertebral level cephalad to T1. Meningovertebral ligaments were labeled and documented in both the lumbar and thoracic regions. RESULTS: Meningovertebral ligaments were found in both the lumbar and thoracic regions of all cadaveric specimens. These ligaments were much more prevalent in the lumbar vertebral column but were also present throughout the thoracic vertebral column. The meningovertebral ligaments in the lumbar region were more robust as well as more frequently encountered than those found in the thoracic region. CONCLUSION: Dural sac attachments to the posterior aspect of the vertebral bodies and the posterior longitudinal ligament could act to traction the dural sac in the event of nuclear bulge or herniation. The prevalence of these ligaments in the lumbar spine, coupled with the high incidence of herniated nucleus pulposus and disc bulges in this region, may compound the effects of disc pathology and result in increased low back pain.     

Racial differences in sensitivity to behavioral integrity: Attitudinal consequences, in-group effects, and "trickle down" among Black and non-Black employees.

Recent research has suggested that employees are highly affected by perceptions of their managers' pattern of word-action consistency, which T. Simons (2002) called behavioral integrity (BI). The authors of the present study suggest that some employee racial groups may be more attentive to BI than others. They tested this notion using data from 1,944 employees working at 107 different hotels and found that Black employees rated their managers as demonstrating lower BI than did non-Black employees. Mediation analyses were consistent with the notion that these differences in perceived BI in turn account for cross-race differences in trust in management, interpersonal justice, commitment, satisfaction, and intent to stay. Results of hierarchical linear modeling were consistent with the idea that middle managers' perceptions of their senior managers' BI "trickle down" to affect line employee perceptions of the middle managers and that this trickle-down effect is stronger for Black employees. The authors interpret these results as indicative of heightened sensitivity to managers' BI on the part of Black employees. They also found a reverse in-group effect, in that Black employees were substantially more critical of Black managers than were non-Black employees. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mechanical and thermal anisotropy for uniaxially and biaxially drawn PET

Sheets of two molding grades of polyethylene terephthalate (PET) with weight average molecular weight of 57,000 and 52,000 were drawn uniaxially or biaxially to ratios of up to 3 in a compression mold at 200°C. Tensile modulus measurements were done for axial and transverse strain. Thermal conductivity measurements were done with a transient‐state surface probe for thermal conductivity in the normal‐to‐the surface direction (Kn), as well as the axial (Ka) and transverse (Kt) directions in the plane of the sheet. Values are presented as normalized by the tensile modulus (Mo) or the normal conductivity (Kno), respectively, of undrawn isotropic specimens. For the uniaxial experiments, both M/Mo and Ka/Kno were linearly related to draw ratio. A regression analysis on results for both grades of PET for Ka/Kno in terms of M/Mo gave Y = 0.804*X + 0.286; std. err. of Y est. equal to 0.17. Kn/Kno decreased slightly. This non‐intrusive conductivity measurement provides a convenient means for monitoring the development of increased modulus in hot‐forging processes. Results on biaxially oriented specimens showed lesser modulus increases with draw ratio, consistent with orientation distribution in a plane, rather than in a single direction. Thermal conductivity (Ka/Kno as well as Kt/Kno), however, increased to a greater degree than for the case of uniaxial draw for the higher molecular weight material, suggesting the possibility of tilting of crystalline aggregates in the deformation process.     

Lactones in butter,butteroil, and margarine

The γ- and Δ-lactones of butter, butteroil, and margarine samples were determined by a recently developed extraction and chromatographic method. A chromatographic column is made of three layers consisting of 6 g aluminum oxide upon which is placed 35 g sodium sulfate and then a fat-Celite mixture obtained by grinding 10 g sample with 35 g Celite 545. The column was eluted with acetonitrile, and the extract was concentrated and lactones determined by gas chromatography. γ-Dodecalactone, Δ-decalactone, Δ-dodecalactone, and Δ-tetradecalactone were recovered quantitatively. Freshly made butter had only 7 ppm of these lactones, whereas commercial samples ranged from 12–30 ppm. Two of eight commercial margarine samples had as much as 10 ppm of Δ-decalactone and Δ-dodecalactone. Comparison of unheated butteroil with butteroil heated at various temperatures showed a correlation of lactone content with time and temperature of heating. Butteroil heated at 65 or 100 C showed increasing levels of lactones up to 8 hr, whereas butteroil heated at 145 or 125 C showed a maximum production at ca. 2 and 4 hr, respectively.     

Some Understanding of Fischer–Tropsch Synthesis from Density Functional Theory Calculations

The combination of density functional theory (DFT) calculations and kinetic analyses is a very useful approach to study surface reactions in heterogeneous catalysis. The present paper reviews some recent work applying this approach to Fischer–Tropsch (FT) synthesis. Emphasis is placed on the following fundamental issues in FT synthesis: (i) reactive sites for both hydrogenation and C–C coupling reactions; (ii) reaction mechanisms including carbene mechanism, CO-insertion mechanism and hydroxyl-carbene mechanism; (iii) selectivity with a focus on CH₄ selectivity, α-olefin selectivity and chain growth probability; and (iv) activity.     

Influence of a nucleating agent on the crystallization behaviour of isotactic polypropylene and elastomer blends

The influence of a nucleating agent on the crystallization behaviour of isotactic polypropylene (iPP), in their blends with poly(styrene-b-ethylene butylene-b-styrene) (SEBS), and a metallocenic ethylene-octene copolymer (EO) was investigated by DSC, optical microscopy and real-time small and wide angle X-ray scattering (SAXS and WAXS) experiments using synchrotron radiation. In non-nucleated iPP/SEBS blends, the crystallization of the iPP matrix occurred in the presence of the styrenic domains which induced a nucleating effect on the process, as observed in the synchrotron experiments. The metallocenic elastomer did not affect the crystallization behaviour of iPP in the iPP/EO blends in non-isothermal experiments, however, the development of crystallinity in the elastomer was restricted. In the nucleated isotactic polypropylene/elastomer blends a significant increase in the crystallinity and the crystallization rate of the iPP matrix was observed due to the presence of the nucleating agent. However, the nucleating efficiency of the additive was strongly affected by the nature and content of the elastomeric component. The nucleating agent efficiency was higher in the presence of the ethylene-octene component than the styrenic elastomer.     

A behavioral view of paradigm debates: Let the data speak.

Because of the strong applied and empirical emphasis of the behavior analysis approach, paradigm debates are considered a waste of time. It is suggested here that the current debate by E. Locke (see record 1981-04363-001) is no exception. It is recommended that instead of engaging in data-sparse academic arguments, interested researchers should conduct experiments that test the various hypotheses and then let the data speak for themselves. (7 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A chemical assessment and HPLC assay validation of bulk paromomycin sulfate

1(S),3(R)-dihydroxy-20(R)-(5'-ethyl-5'-hydroxy-hepta-1'(E),3' (E)-dien-1'-yl)-9,10-secopregna-5(Z),7(E),10(19)-triene (EB1089) is a novel synthetic analog of 1 alpha,25-dihydroxyvitamin D [1,25-(OH)2D3] with potential for use in the treatment of hyperproliferative disorders. It has an altered side-chain structure compared to 1,25-(OH)2D3, featuring 26,27 dimethyl groups, insertion of an extra carbon atom (24a) at C-24, and two double bonds at C-22,23 and C-24,24a. In vitro metabolism of EB1089 was studied in a human keratinocyte cell model, HPK1A-ras, previously shown to metabolize 1,25-(OH)2D3. Four metabolites were formed, all of which possessed the same UV chromophore as EB1089, indicating the retention of the side-chain conjugated double bond system. Two metabolites were present in sufficient quantities to identify them as 26-hydroxy EB1089 (major product) and 26a-hydroxy EB1089 (minor product), based on mass spectral analysis and cochromatography with synthetic standards. Similar metabolites were generated in vivo and using a liver postmitochondrial fraction in vitro (Kissmeyer et al., companion paper). Studies with the human hepatoma Hep G2 gave rise to 2 isomers of 26-hydroxy EB1089. Studies using ketoconazole, a general cytochrome P450 inhibitor, implicated cytochrome P450s in the formation of the EB1089 metabolites. COS-1 transfection cell experiments using vectors containing CYP27 and CYP24 suggest that these cytochrome P450s are probably not involved in 26- or 26a-hydroxylation of EB1089. Other experiments that examined the HPK1A-ras metabolism of related analogs containing only a single side-chain double bond: 1(S),3(R)-dihydroxy-20(R)-(5'-ethyl-5'-hydroxy-hepta-1' (E)-en-1'-yl)-9,10-secopregna-5(Z),7(E),10(19)-triene (MC1473; double bond at C-22,23) and 1(S),3(R)-dihydroxy-20(R)-(5'-ethyl-5'-hydroxy-hepta-3'(E)-en-1'-yl)-9, 10-secopregna-5(Z),7(E),10(19)-triene (MC1611; double bond at C-24,24a) revealed that the former compound was subject to 24-hydroxylation and the latter compound was mainly 23-hydroxylated. Metabolism experiments involving EB1089, MC1473, and MC1611 in competition with [1 beta-3H]1,25-(OH)2D3 in HPK1A-ras confirmed that CYP24 is probably not involved in the metabolism of EB1089 whereas, in the case of MC1473 and MC1611, it does appear to carry out side-chain hydroxylation. Our interpretation is that the conjugated double bond system in the side-chain of EB1089 is responsible for directing the target cell hydroxylation to the distal positions, C-26 and C-26a. We conclude that EB1089 is slowly metabolized via unique in vitro metabolic pathways, and that these features may explain the relative stability of EB1089 compared to other analogs in vivo.     

Demand characteristics in assessing motion sickness in a virtual environment: or does taking a motion sickness questionnaire make you sick?

The experience of motion sickness in a virtual environment may be measured through pre and postexperiment self-reported questionnaires such as the Simulator Sickness Questionnaire (SSQ). Although research provides converging evidence that users of virtual environments can experience motion sickness, there have been no controlled studies to determine to what extent the user's subjective response is a demand characteristic resulting from pre and posttest measures. In this study, subjects were given either SSQ's both pre and postvirtual environment immersion, or only postimmersion. This technique tested for contrast effects due to demand characteristics in which administration of the questionnaire itself suggested to the participant that the virtual environment may produce motion sickness. Results indicate that reports of motion sickness after immersion in a virtual environment are much greater when both pre and postquestionnaires are given than when only a posttest questionnaire is used. The implications for assessments of motion sickness in virtual environments are discussed.