Direct contact and authoritarianism as moderators between extended contact and reduced prejudice: Lower threat and greater trust as mediators

Using a representative sample of Dutch adults (N = 1238), we investigated the moderating influence of direct contact and authoritarianism on the potential of extended contact to reduce prejudice. As expected, direct contact and authoritarianism moderated the effect of extended contact on prejudice. Moreover, the third-order moderation effect was also significant, revealing that extended contact has the strongest effect among high authoritarians with low levels of direct contact. We identified trust and perceived threat as the mediating processes underlying these moderation effects. The present study thus attests to the theoretical and practical relevance of reducing prejudice via extended contact. The discussion focuses on the role of extended contact in relation to direct contact and authoritarianism as well as on the importance of trust in intergroup contexts

Changing the ideological roots of prejudice: Longitudinal effects of ethnic intergroup contact on social dominance orientation

Social Dominance Orientation (SDO) has been reported to be strongly related to a multitude of intergroup phenomena, but little is known about situational experiences that may influence SDO. Drawing from research on intergroup contact theory, we argue that positive intergroup contact is able to reduce SDO-levels. The results of an intergroup contact intervention study among high school students (Study 1, N=71) demonstrated that SDO-levels were indeed attenuated after the intervention. Furthermore, this intervention effect on SDO was especially pronounced among students reporting a higher quality of contact. A cross-lagged longitudinal survey among adults (Study 2, N=363) extended these findings by demonstrating that positive intergroup contact is able to decrease SDO over time. Moreover, we did not obtain evidence for the idea that people high in SDO would engage less in intergroup contact. These findings indicate that intergroup contact erodes one of the important socio-ideological bases of generalized prejudice and discrimination

Pioglitazone Prevents Capillary Rarefaction in Streptozotocin-Diabetic Rats Independently of Glucose Control and Vascular Endothelial Growth Factor Expression

Background/Aims: Reduction of capillary network density occurs early in the development of metabolic syndrome and may be relevant for the precipitation of diabetes. Agonists of the peroxisome proliferator-activated receptor (PPAR)-gamma transcription factor are vasculoprotective, but their capacity for structural preservation of the microcirculation is unclear. Methods: Male Wistar rats were rendered diabetic by streptozotocin and treated with pioglitazone in chow for up to 12 weeks. Capillary density was determined in heart and skeletal muscle after platelet endothelial cell adhesion molecule-1 (PECAM-1) immunostaining. Hallmarks of apoptosis and angiogenesis were determined. Results: Capillary density deteriorated progressively in the presence of hyperglycemia (from 971/mm(2) to 475/mm(2) in quadriceps muscle during 13 weeks). Pioglitazone did not influence plasma glucose, left ventricular weight, or body weight but nearly doubled absolute and relative capillary densities compared to untreated controls (1.2 vs. 0.6 capillaries/myocyte in heart and 1.5 vs. 0.9 capillaries/myocyte in quadriceps muscle) after 13 weeks of diabetes. No antiapoptotic or angiogenic influence of pioglitazone was detected while a reduced expression of hypoxia-inducible factor-3 alpha and PPAR coactivator-1 alpha (PGC-1 alpha) mRNA as well as vascular endothelial growth factor (VEGF) protein possibly occurred as a consequence of improved vascularization. Conclusion: Pioglitazone preserves microvascular structure in diabetes independently of improvements in glycemic control and by a mechanism unrelated to VEGF-mediated angiogenesis. Copyright (C) 2012 S. Karger AG, Base

Why Measurement Invariance is Important in Comparative Research. A Response to Welzel et al. (2021)

Welzel et al. (2021) claim that non-invariance of instruments is inconclusive and inconsequential in the field for cross-cultural value measurement. In this response, we contend that several key arguments on which Welzel et al. (2021) base their critique of invariance testing are conceptually and statistically incorrect. First, Welzel et al. (2021) claim that value measurement follows a formative rather than reflective logic. Yet they do not provide sufficient theoretical arguments for this conceptualization, nor do they discuss the disadvantages of this approach for validation of instruments. Second, their claim that strong inter-item correlations cannot be retrieved when means are close to the endpoint of scales ignores the existence of factor-analytic approaches for ordered-categorical indicators. Third, Welzel et al. (2021) propose that rather than of relying on invariance tests, comparability can be assessed by studying the connection with theoretically related constructs. However, their proposal ignores that external validation through nomological linkages hinges on the assumption of comparability. By means of two examples, we illustrate that violating the assumptions of measurement invariance can distort conclusions substantially. Following the advice of Welzel et al. (2021) implies discarding a tool that has proven to be very useful for comparativists

Age-related microstructural differences quantified using myelin water imaging and advanced diffusion MRI

Age-related microstructural differences have been detected using diffusion tensor imaging (DTI). Although DTI is sensitive to the effects of aging, it is not specific to any underlying biological mechanism, including demyelination. Combining multiexponential T2 relaxation (MET2) and multishell diffusion MRI (dMRI) techniques may elucidate such processes. Multishell dMRI and MET2 data were acquired from 59 healthy participants aged 17-70 years. Whole-brain and regional age-associated correlations of measures related to multiple dMRI models (DTI, diffusion kurtosis imaging [DKI], neurite orientation dispersion and density imaging [NODDI]) and myelin-sensitive MET2 metrics were assessed. DTI and NODDI revealed widespread increases in isotropic diffusivity with increasing age. In frontal white matter, fractional anisotropy linearly decreased with age, paralleled by increased "neurite" dispersion and no difference in myelin water fraction. DKI measures and neurite density correlated well with myelin water fraction and intracellular and extracellular water fraction. DTI estimates remain among the most sensitive markers for age-related alterations in white matter. NODDI, DKI, and MET2 indicate that the initial decrease in frontal fractional anisotropy may be due to increased axonal dispersion rather than demyelination

3D cell bioprinting of self-assembling peptide-based hydrogels

Bioprinting of 3D cell-laden constructs with well-defined architectures and controlled spatial distribution of cells is gaining importance in the field of Tissue Engineering. New 3D tissue models are being developed to study the complex cellular interactions that take place during both tissue development and in the regeneration of damaged and/or diseased tissues. Despite advances in 3D printing technologies, suitable hydrogels or ‘bioinks’ with enhanced printability and cell viability are lacking. Here we report a study on the 3D bioprinting of a novel group of self-assembling peptide-based hydrogels. Our results demonstrate the ability of the system to print well-defined 3D cell laden constructs with variable stiffness and improved structural integrity, whilst providing a cell-friendly extracellular matrix “like” microenvironment. Biological assays reveal that mammary epithelial cells remain viable after 7 days of in vitro culture, independent of the hydrogel stiffness

Feasibility investigation of direct laser cutting process of metal foam with high pore density

To avoid damage to the pore structure of metal foam, a laser cutting process for efficiently and directly cutting metal foam into regular shapes is proposed. After analyzing the proposed laser cutting process, its effects when applied to three different types of metal material (copper, ferroalloy, and nickel) and two levels of pore density, namely 90 and 110 pores per inch (PPI), were investigated. The results show that metal foam with a good surface quality can be obtained without damaging the pore structure by using the proposed laser cutting process. Of the three metal types considered, the highest material removal rate (MRR) and material oxidation rate (MOR) were observed for ferroalloy foam. Of the two pore densities, metal foam of 90 PPI showed a larger material removal rate than metal foam of 110 PPI. The MRR and MOR increased with an increase in the laser output power and decrease in the scanning speed. Using a central composite experimental design method, optimized processing parameters of 26 W laser output power and 475 mm/s scanning speed were adopted to cut the metal foam with a high pore density

Relationships of low serum vitamin D3 with anthropometry and markers of the metabolic syndrome and diabetes in overweight and obesity

Low serum 25 hydroxyvitamin D3 (vitamin D3) is known to perturb cellular function in many tissues, including the endocrine pancreas, which are involved in obesity and type II diabetes mellitus (TIIDM). Vitamin D3 insufficiency has been linked to obesity, whether obesity is assessed by body mass index (BMI) or waist circumference (waist). Central obesity, using waist as the surrogate, is associated with the metabolic syndrome (MetSyn), insulin resistance, TIIDM and atherosclerotic cardiovascular disease (CVD). We tested how vitamin D3 was related to measures of fat mass, MetSyn markers, haemoglobin A1c (HbA1c) and MetSyn in a cross-sectional sample of 250 overweight and obese adults of different ethnicities. There were modest inverse associations of vitamin D3 with body weight (weight) (r = -0.21, p = 0.0009), BMI (r = -0.18, p = 0.005), waist (r = -0.14, p = 0.03), [but not body fat % (r = -0.08, p = 0.24)], and HbA1c (r = -0.16, p = 0.01). Multivariable regression carried out separately for BMI and waist showed a decrease of 0.74 nmol/L (p = 0.002) in vitamin D3 per 1 kg/m2 increase in BMI and a decrease of 0.29 nmol/L (p = 0.01) per 1 cm increase in waist, with each explaining approximately 3% of the variation in vitamin D3 over and above gender, age, ethnicity and season