Acute Intake of Plant Stanol Esters Induces Changes in Lipid and Lipoprotein Metabolism‐Related Gene Expression in the Liver and Intestines of Mice

The kinetics of plant stanol uptake and routing in 8‐week‐old C57BL/6J mice were determined after a plant stanol ester gavage. In addition, acute changes in intestinal and hepatic gene expression were investigated. Mice were fed a plant sterol/stanol poor diet from weaning. At the age of 8 weeks, they received an oral gavage consisting of 0.25 mg cholesterol + 50 mg plant stanol esters dissolved in olive oil. Animals were euthanized at different time points. In a second comparable set‐up, mesenteric lymph‐cannulated versus sham‐operated mice received the same oral gavage, which was now deuterium labeled. Intestinal and hepatic sitostanol concentrations increased within 15 min post‐gavage. This rapid hepatic appearance was absent in lymph‐cannulated mice, suggesting a very fast lymph‐mediated uptake. Hepatic mRNA expression of SREBP2 and its target genes rapidly decreased, whereas expression of LXR target genes increased. The intestinal SREBP2 pathway was increased, whereas the expression of LXR target genes hardly changed. The fivefold and sixfold increased expression of intestinal LDLr and PCSK9 is suggestive of TICE activation. We conclude that in C57BL/6J mice plant stanol kinetics are fast, and affect intestinal and hepatic gene expression within 15 min postprandial after lymph‐mediated uptake.     

Preparing pre-service teachers to integrate technology in education: A synthesis of qualitative evidence

This study reviewed qualitative studies that focused on strategies to prepare pre-service teachers to integrate technology into their lessons. A meta-ethnography approach was utilized to locate, critically appraise, and synthesize the results of these studies. Based on an extensive search in the Web of Science, 19 articles were included in this synthesis. The results were divided into two parts: (1) key themes explicitly related to the preparation of pre-service teachers (e.g., using teacher educators as role models, learning technology by design, scaffolding authentic technology experiences), and (2) conditions necessary at the institutional level (e.g., technology planning and leadership, co-operation within and between institutions, training staff). To present how these key themes related to each other, an overarching model was developed. By interpreting the results of the review, recommendations were discussed for pre-service teacher technology training and future research.     

The association of parent behaviors, chronic pain, and psychological problems with venipuncture distress in infants: The Generation R study.

Objective: To examine the association of parent behavior with infant distress during a potentially painful medical procedure. A second aim was to investigate the association of parent chronic pain and psychological problems with parent behavior and infant distress during the procedure. Design: Population-based cohort study with both cross-sectional and prospective measurements. Main Outcome Measures: Video recordings of 275 parents and their 14-month-old infant undergoing venipuncture were coded with an observational instrument to yield measures of infant distress behaviors and parent behaviors, such as reassuring, showing empathy, praising, and distracting. Parent chronic pain and psychological problems were assessed through questionnaires. Results: Infants cried 58% of procedure duration. Parent reassuring occurred 34% of procedure duration, and parent distracting occurred 37% of procedure duration. Infant distress was positively related to parent reassuring and negatively related to parent praising. Parent chronic pain was related to increased parent distracting but not to parent reassuring. Parent psychological problems were not associated with parent behavior and infant distress. Conclusion: Parent behavior rather than psychological traits is related to increased venipuncture distress in young infants. This finding suggests that the focus should be on interventions based on behavior modification. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fabrication of zirconia-based targets for transmutation

The fabrication of homogeneous (Am,Y,Zr)O_2−x pellets and heterogeneous pellets, containing (Am,Y,Zr)O_2−x spheres dispersed in an inert matrix, by dust-free processes has been investigated. Due to the high activity of americium, the preparatory fabrication tests and process development are being carried out using cerium analogue element. The sol gel route is used to produce highly porous Y_0.15Zr_0.85O_2−x spheres, which are then infiltrated with a cerium nitrate solution to give (Ce,Y,Zr)O_2−x. The goal (28 wt% Ce) can be achieved. Homogeneous targets with densities up to 94 %TD have been obtained.     

Slow fusion of liposomes composed of membrane-spanning lipids

Vascular calcification (VC), which is described in the elderly and in diabetics, is frequently seen in uraemia. It is usually regarded as having little significance. We studied the roentgenological appearance of VC in a homogeneous group of 38 long-hours haemodialysis patients whose longevity on dialysis allowed sustained (10-25 years) follow-up, including annual skeletal surveys and thrice-yearly clinical examinations and biochemical profiles. We compiled a dossier of clinical and laboratory parameters from the start of dialysis to the present day. We were able to analyze the natural history of VC and to determine which clinical parameters were linked with progression. We found that VC became steadily more prevalent-at dialysis onset present in 39% of the patients, but in 92% after an average dialysis duration of 16 years, with a mean onset 9.7 years after starting dialysis. As well as becoming more prevalent, the calcification became progressively more severe in most patients. There were two patterns of VC: axial (aorta and iliac and femoral arteries), seen alone in 32% of the patients, and peripheral (digital arteries), seen alone in 3% of patients. Most patients (65%) had evidence of both types. Calcification was scored for site and severity. Patient age (r = 0.57, p < 0.001), systolic blood pressure (r = 0.54, p < 0.001), hyperparathyroidism (reduced progression after parathyroidectomy), plasma phosphate (r = 0.34, p = 0.042), and vitamin D concentrations (r = 0.53, p < 0.001) were the principal determinants of severity and rate of progression of VC in this population. There was a weak negative association between progression and serum ferritin (r = -0.33, p = 0.046). The reduced vessel compliance that results from VC is likely to be cardiovascularly deleterious. In severe cases, tissue perfusion or vascular access for haemodialysis can be compromised. VC and accelerated cardiovascular mortality are common to uraemia, diabetes, and systolic hypertension in the elderly. Better understanding of these pathological processes may permit intervention and possibly lead to a reduction in cardiovascular mortality.     

Amplified expression, purification and functional reconstitution of the dipeptide and tripeptide transport protein of Lactococcus lactis

Transport of hydrophilic dipeptides and tripeptides into Lactococcus lactis is mediated by a proton-motive-force-driven peptide-transport protein (DtpT) that shares similarity to eukaryotic peptide transporters, e.g. from yeasts, plants, and the kidney and small intestine of rabbit, man and rat. The expression level of DtpT protein in L. lactis was increased (20-40-fold) to approximately 10% of total integral membrane protein by means of a low-copy-number vector and selecting the appropriate growth conditions. Membrane vesicles bearing the DtpT-His6 protein (containing a C-terminal factor-Xa cleavage site and a six-histidine-tag) showed a Pro-Ala uptake activity that was half that of membranes containing the wild-type protein. The activity in the DtpT-His6 membrane vesicles increased at least 50% upon removal of the His6 tag from the protein. More than 95% DtpT was solubilized from L. lactis membranes in the presence of 1% (mass/vol.) n-dodecyl-beta-D-maltoside, and approximately 2 mg DtpT-His6 was purified by Ni2+-chelate affinity chromatography from 100 mg membrane protein. Purified DtpT-His6 was reconstituted unidirectionally into detergent-saturated formed liposomes, which were prepared from Escherichia coli phospholipid and egg phosphatidylcholine; the detergent was removed by adsorption to polystyrene beads. The highest uptake activities were obtained when DtpT was incorporated into liposomes that were treated with a low amount of n-dodecyl-beta-D-maltoside (onset of liposome solubilization). The uptake activity could be improved by addition of NaCl (200 mM) and lipids (2 mg/ml) during the solubilization, purification and reconstitution steps.     

Thermodynamic modelling of LiF-LnF3 and LiF-AnF3 phase diagrams

The phase diagrams of the LiF-LnF₃ series, where Ln = La-Sm, and of LiF-AnF₃, where An = U, Pu, have been optimized using Redlich-Kister functions. The phase diagrams of LiF-AmF₃ and LiF-PuF₃-AmF₃ have been calculated. The necessary Gibbs energy functions for americium trifluoride were defined by use of a semi-empirical method. The excess Gibbs energy terms, which are expressed as Redlich-Kister polynomials and describe the effect of interaction between the two fluoride components in the liquid phase, were obtained by translating the trends observed in the lanthanide trifluoride series into the actinide series. A single eutectic has been found in the LiF-AmF₃ system with the eutectic point at ?33 mole% AmF₃ and at ?951 K.     

Exploring the potential of the will,skill, tool model in Ghana: Predicting prospective and practicing teachers’ use of technology

Research has shown that will (positive attitudes), skill (technology competency), and tool (access to technology tools) are all essential ingredients for a teacher to effectively integrate information technology into classroom practices. This study focuses on the will, skill and tool as essential measures for the predictability of technology integration, reported by the study participants and measured by stages of adoption of teachers in Ghana. Attempts are made to explore the extent to which these parameters differ among the teachers and also influence technology integration. Furthermore, the parameters are proposed for use in modelling the process of technology integration for these teachers. Well validated instruments spanning the areas of attitudes, competencies, access and technology integration proficiencies were used to collect data from 120 mathematics prospective teachers and 60 practicing mathematics teachers from Ghana. The data was analyzed using regression analysis. The results indicated that lack of teacher anxiety was the most important dimension of attitudes, and that skill is the strongest predictor of classroom integration of technology for the teachers. Significant differences existed between practicing and prospective teachers’ computer anxieties, competencies, and access levels.     

Technology and young children: How 4–7 year olds perceive their own use of computers

This study examined young children’s access, perceptions and use of technology within and outside of school settings. One hundred sixty seven children from varied ethnic and socio-economic backgrounds participated in the study. Regardless of gender, socio-economic status or ethnic group, most children had access to computers in and outside of schools. In both settings, pre-K through grade 2 children report that they primarily use computers to play games. Children’s attitudes toward computers are positive. Older children tend to use the computer more often, are better able to operate the computer and their attitudes towards computers are more positive. Boys’ attitudes towards computers are more positive than the attitudes of girls, but no gender differences were found for computer use nor ability level. While no significant differences were found between the attitudes of Dutch and immigrant children, the latter group indicated more frequent use. Also, children from a lower socio-economic neighborhood had more positive attitudes towards computers and used computers slightly more often than middle class children. The findings of this study inform the debate on the desirability of young children’s exposure to computers at home as well as in educational settings. Further, these findings may help educators and parents to both critically assess their current practices (e.g. the relative value of the most frequently used applications – games), and strive to integrate developmentally appropriate uses of technology at home and in classrooms.