Dimensional Comparison Theory : Paradoxical relations between self-beliefs and achievements in multiple domains

The internal/external frame of reference (I/E) model posits paradoxical relations between achievement and self-concept in mathematics and verbal domains, in which achievement in each domain has a positive effect on self-concept in the matching domain (e.g., mathematics achievement on mathematics self-concept) but a negative (contrastive) effect on self-concept in the non-matching domain (e.g., mathematics achievement on verbal self-concept). Extending the I/E model, Dimensional Comparison Theory (DCT) posits that self-evaluations are based on dimensional comparisons (e.g., how my accomplishments in one domain compare with my accomplishments in another domain) as well as the more traditional social and temporal comparisons, and on other sources of information about one's accomplishments. Extending the traditional tests of the I/E model, DCT predicts strong contrast effects only for contrasting domains that are at the opposite ends of the theoretical continuum of academic self-concept (far comparisons: e.g., the negative effect of math achievement on verbal self-concept), but much weaker negative contrast or even positive assimilation effects for complementary domains that are close to each other (near domains: e.g., positive effects of math achievement on physics self-concept; positive effects of native language on foreign language self-concept). Here we illustrate new predictions, theoretical insights, and methodology associated with DCT based on multiple academic domains (native language, foreign language, history, biology, physics and math), showing significant contrast effects for far comparisons and significantly less contrast or assimilation effects for near domains

What to do when scalar invariance fails: The extended alignment method for multi-group factor analysis comparison of latent means across many groups

Scalar invariance is an unachievable ideal that in practice can only be approximated; often using potentially questionable approaches such as partial invariance based on a stepwise selection of parameter estimates with large modification indices. Study 1 demonstrates an extension of the power and flexibility of the alignment approach for comparing latent factor means in large-scale studies (30 OECD countries, 8 factors, 44 items, N = 249,840), for which scalar invariance is typically not supported in the traditional confirmatory factor analysis approach to measurement invariance(CFA-MI). Importantly, we introduce an alignment-within-CFA (AwC) approach, transforming alignment from a largely exploratory tool into a confirmatory tool, and enabling analyses that previously have not been possible with alignment (testing the invariance of uniquenesses and factor variances/covariances; multiple-group MIMIC models; contrasts on latent means) and structural equation models more generally. Specifically, it also allowed a comparison of gender differences in a 30-country MIMIC AwC (i.e., a SEM with gender as a covariate) and a 60-group AwC CFA (i.e., 30 countries × 2 genders) analysis. Study 2, a simulation study following up issues raised in Study 1, showed that latent means were more accurately estimated with alignment than with the scalar CFA-MI, and particularly with partial invariance scalar models based on the heavily criticized stepwise selection strategy. In summary, alignment augmented by AwC provides applied researchers from diverse disciplines considerable flexibility to address substantively important issues when the traditional CFA-MI scalar model does not fit the data

Közművelődési jelenségek és jelentések. Az ÁMK

Many classroom climate studies suffer from 2 critical problems: They (a) treat climate as a student-level (L1) variable in single-level analyses instead of a classroom-level (L2) construct in multilevel analyses; and (b) rely on manifest-variable models rather than on latent-variable models that control measurement error at L1 and L2, and sampling error in the aggregation of L1 ratings to form L2 constructs. On the basis of an analysis of 2,541 students in Grades 5 or 6 from 89 classrooms, the authors demonstrate doubly latent multilevel structural equation models that overcome both of these problems. The results show that L2 classroom climate (a higher-order factor representing classroom mastery goal orientation, challenge, and teacher caring) had positive effects on self-efficacy and achievement. The authors conclude with a discussion of related issues (e.g., the meaning of L2 constructs vs. L1 residuals, the dimensionality of climate constructs at L2) and guidelines for future research

Novel developments in endoscopic mucosal imaging

Endoscopic techniques such as High-definition and optical-chromoendoscopy have had enormous impact on endoscopy practice. Since these techniques allow assessment of most subtle morphological mucosal abnormalities, further improvements in endoscopic practice lay in increasing the detection efficacy of endoscopists. Several new developments could assist in this. First, web based training tools could improve the skills of the endoscopist for enhancing the detection and classification of lesions. Secondly, incorporation of computer aided detection will be the next step to raise endoscopic quality of the captured data. These systems will aid the endoscopist in interpreting the increasing amount of visual information in endoscopic images providing real-time objective second reading. In addition, developments in the field of molecular imaging open opportunities to add functional imaging data, visualizing biological parameters, of the gastrointestinal tract to white-light morphology imaging. For the successful implementation of abovementioned techniques, a true multi-disciplinary approach is of vital importance

Evidence for a three-nucleon-force effect in proton-deuteron elastic scattering

Developments in spin-polarized internal targets for storage rings have permitted measurements of 197 MeV polarized protons scattering from vector polarized deuterons. This work presents measurements of the polarization observables A_y, iT_11, and C_y,y in proton-deuteron elastic scattering. When compared to calculations with and without three-nucleon forces, the measurements indicate that three-nucleon forces make a significant contribution to the observables. This work indicates that three-body forces derived from static nuclear properties appear to be crucial to the description of dynamical properties.Comment: 8 pages 2 figures Latex, submitted to Phys. Rev. Letter

Optimization of cw sodium laser guide star efficiency

Context: Sodium laser guide stars (LGS) are about to enter a new range of laser powers. Previous theoretical and numerical methods are inadequate for accurate computations of the return flux and hence for the design of the next-generation LGS systems. Aims: We numerically optimize the cw (continuous wave) laser format, in particular the light polarization and spectrum. Methods: Using Bloch equations, we simulate the mesospheric sodium atoms, including Doppler broadening, saturation, collisional relaxation, Larmor precession, and recoil, taking into account all 24 sodium hyperfine states and on the order of 100 velocity groups. Results: LGS return flux is limited by "three evils": Larmor precession due to the geomagnetic field, atomic recoil due to radiation pressure, and transition saturation. We study their impacts and show that the return flux can be boosted by repumping (simultaneous excitation of the sodium D2a and D2b lines with 10-20% of the laser power in the latter). Conclusions: We strongly recommend the use of circularly polarized lasers and repumping. As a rule of thumb, the bandwidth of laser radiation in MHz (at each line) should approximately equal the launched laser power in Watts divided by six, assuming a diffraction-limited spot size.Comment: 15 pages, 12 figures, to be published in Astronomy & Astrophysics, AA/2009/1310

School or Work? The Choice May Change Your Personality

According to the social-investment principle, entering new environments is associated with new social roles that influence people's behaviors. In this study, we examined whether young adults' personality development is differentially related to their choice of either an academic or a vocational pathway (i.e., entering an academic-track school or beginning vocational training). The personality constructs of interest were Big Five personality traits and vocational-interest orientations. We used a longitudinal study design and propensity-score matching to create comparable groups before they entered one of the pathways and then tested the differences between these groups 6 years later. We expected the vocational pathway to reinforce more mature behavior and curtail investigative interest. Results indicated that choosing the vocational compared with the academic pathway was associated with higher conscientiousness and less interest in investigative, social, and enterprising activities

Colorectal anastomotic leak:Transcriptomic profile analysis

BACKGROUND: Anastomotic leakage in patients undergoing colorectal surgery is associated with morbidity and mortality. Although multiple risk factors have been identified, the underlying mechanisms are mainly unknown. The aim of this study was to perform a transcriptome analysis of genes underlying the development of anastomotic leakage. METHODS: A set of human samples from the anastomotic site collected during stapled colorectal anastomosis were used in the study. Transcriptomic profiles were generated for patients who developing anastomotic leakage and case-matched controls with normal anastomotic healing to identify genes and biological processes associated with the development of anastomotic leakage. RESULTS: The analysis included 22 patients with and 69 without anastomotic leakage. Differential expression analysis showed that 44 genes had adjusted P < 0.050, consisting of two upregulated and 42 downregulated genes. Co-functionality analysis of the 150 most upregulated and 150 most downregulated genes using the GenetICA framework showed formation of clusters of genes with different enrichment for biological pathways. The enriched pathways for the downregulated genes are involved in immune response, angiogenesis, protein metabolism, and collagen cross-linking. The enriched pathways for upregulated genes are involved in cell division. CONCLUSION: These data indicate that patients who develop anastomotic leakage start the healing process with an error at the level of gene regulation at the time of surgery. Despite normal macroscopic appearance during surgery, the transcriptome data identified several differences in gene expression between patients who developed anastomotic leakage and those who did not. The expressed genes and enriched processes are involved in the different stages of wound healing. These provide therapeutic and diagnostic targets for patients at risk of anastomotic leakage