Evaluating the Gifted Program of an Urban School District using a Modified Regression Discontinuity Design

This paper examines the impact of a gifted program on retention in an urban school district using a regression discontinuity design. Gifted programs often employ IQ thresholds for admission, with those above the threshold being admitted. One common problem with the RD design arises if the forcing variable (the IQ score) is manipulated, thus invalidating the standard research design. We proposed a modified RD estimator that deals with manipulation in the forcing variable. Once we properly correct for manipulation of test scores around the cut-off points, we find evidence that the gifted program offered by the district has a positive effect on retention of higher income students.

Self-organized nanostructuring in Zr0.69Al0.31N thin films studied by atom probe tomography

We have applied atom probe tomography (APT) to analyze self-organizing structures of wear-resistant Zr0.69Al0.31N thin films grown by magnetron sputtering. Transmission electron microscopy shows that these films grow as a three-dimensional nanocomposite, consisting of interleaved lamellae in a labyrinthine structure, with an in-plane size scale of ~ 5 nm. The structure was recovered in the Al APT signal, while the Zr and N data lacked structural information. The onset of the self-organized labyrinthine growth was observed to occur by surface nucleation, 5–8 nm above the MgO substrate, due to increasing Zr–Al compositional fluctuations during elemental segregation. At a final stage, the labyrinthine growth mode was observed to be interrupted by the formation of larger ZrN grains

Assessing the safety attitudes questionnaire (SAQ), German language version in Swiss university hospitals - A validation study

Background: Improving patient safety has become a major focus of clinical care and research over the past two decades. An institution's patient safety climate represents an essential component of ensuring a safe environment and thereby can be vital to the prevention of adverse events. Covering six patient safety related factors, the Safety Attitudes Questionnaire (SAQ) is a validated and widely used instrument to measure the patient safety climate in clinical areas. The objective of this study was to assess the psychometric properties of the German language version of the SAQ. Methods. A survey was carried out in two University Hospitals in Switzerland in autumn 2009 where the SAQ was distributed to a sample of 406 nurses and physicians in medical and surgical wards. Following the American Educational Research Association guidelines, we tested the questionnaire validity by levels of evidence: content validity, internal structure and relations to other variables. Confirmatory factor analysis was used to examine factor structure. Cronbach's alphas and inter-item correlations were calculated to examine internal consistency reliability. Results: A total of 319 questionnaires were completed representing an overall response rate of 78.6%. For three items, the item content validity index was <0.75. Confirmatory factor analysis showed acceptable model fit (RMSEA = 0.045; CFI = 0.944) for the six-factor model. Additional exploratory factor analysis could not identify a better factor model. SAQ factor scores showed positive correlations with the Safety Organizing Scale (r =.56 -.72). The SAQ German version showed moderate to strong internal consistency reliability indices (Cronbach alpha =.65 -.83). Conclusions: The German language version of the SAQ demonstrated acceptable to good psychometric properties and therefore shows promise to be a sound instrument to measure patient safety climate in Swiss hospital wards. However, the low item content validity and large number of missing responses for several items suggest that improvements and adaptations in translation are required for select items, especially within the perception of management scale. Following these revisions, psychometric properties should reassessed in a randomly selected sample and hospitals and departments prior to use in Swiss hospital settings. © 2013 Zimmermann et al.; licensee BioMed Central Ltd

Frequency behavior of Raman coupling coefficient in glasses

Low-frequency Raman coupling coefficient of 11 different glasses is evaluated. It is found that the coupling coefficient demonstrates a universal linear frequency behavior near the boson peak maximum and a superlinear behavior at very low frequencies. The last observation suggests vanishing of the coupling coefficient when frequency tends to zero. The results are discussed in terms of the vibration wavefunction that combines features of localized and extended modes.Comment: 8 pages, 9 figure

Oral and Fecal Campylobacter concisus Strains Perturb Barrier Function by Apoptosis Induction in HT-29/B6 Intestinal Epithelial Cells

Campylobacter concisus infections of the gastrointestinal tract can be accompanied by diarrhea and inflammation, whereas colonization of the human oral cavity might have a commensal nature. We focus on the pathophysiology of C. concisus and the effects of different clinical oral and fecal C. concisus strains on human HT-29/B6 colon cells. Six oral and eight fecal strains of C. concisus were isolated. Mucus-producing HT-29/B6 epithelial monolayers were infected with the C. concisus strains. Transepithelial electrical resistance (Rt) and tracer fluxes of different molecule size were measured in Ussing chambers. Tight junction (TJ) protein expression was determined by Western blotting, and subcellular TJ distribution was analyzed by confocal laser-scanning microscopy. Apoptosis induction was examined by TUNEL-staining and Western blot of caspase-3 activation. All strains invaded confluent HT-29/B6 cells and impaired epithelial barrier function, characterized by a time- and dose-dependent decrease in Rt either after infection from the apical side but even more from the basolateral compartment. TJ protein expression changes were sparse, only in apoptotic areas of infected monolayers TJ proteins were redistributed. Solely the barrier-forming TJ protein claudin-5 showed a reduced expression level to 66±8% (P<0.05), by expression regulation from the gene. Concomitantly, Lactate dehydrogenase release was elevated to 3.1±0.3% versus 0.7±0.1% in control (P<0.001), suggesting cytotoxic effects. Furthermore, oral and fecal C. concisus strains elevated apoptotic events to 5-fold. C. concisus-infected monolayers revealed an increased permeability for 332 Da fluorescein (1.74±0.13 vs. 0.56±0.17 10−6 cm/s in control, P<0.05) but showed no difference in permeability for 4 kDa FITC-dextran (FD-4). The same was true in camptothecin-exposed monolayers, where camptothecin was used for apoptosis induction

Building democracy from below : lessons from Western Uganda

How to achieve democratisation in the neopatrimonial and agrarian environments that predominate in sub-Saharan Africa continues to present a challenge for both development theory and practice. Drawing on intensive fieldwork in Western Uganda, this paper argues that Charles Tilly’s ‘democratisation as process’ provides us with the framework required to explain the ways in which particular kinds of association can advance democratisation from below. Moving beyond the current focus on how elite-bargaining and certain associational forms may contribute to liberal forms of democracy, this approach helps identify the intermediate mechanisms involved in building democracy from below, including the significance of challenging categorical inequalities, notably through the role of producer groups, and of building trust networks, cross-class alliances and synergistic relations between civil and political society. The evidence and mode of analysis deployed here help suggest alternative routes for supporting local efforts to build democracy from below in sub-Saharan Africa

Coming Back to Life: The Permeability of Past and Present, Mortality and Immortality, Death and Life in the Ancient Mediterranean

The lines between death and life were neither fixed nor finite to the peoples of the ancient Mediterranean. For most, death was a passageway into a new and uncertain existence. The dead were not so much extinguished as understood to be elsewhere, and many perceived the deceased to continue to exercise agency among the living. Even for those more skeptical of an afterlife, notions of coming back to life provided frameworks in which to conceptualize the on-going social, political, and cultural influence of the past. This collection of essays examines how notions of coming back to life shape practices and ideals throughout the ancient Mediterranean. All contributors focus on the common theme of coming back to life as a discursive and descriptive space in which antique peoples construct, maintain, and negotiate the porous boundaries between past and present, mortality and immortality, death and life

Pseudopotential study of binding properties of solids within generalized gradient approximations: The role of core-valence exchange-correlation

In ab initio pseudopotential calculations within density-functional theory the nonlinear exchange-correlation interaction between valence and core electrons is often treated linearly through the pseudopotential. We discuss the accuracy and limitations of this approximation regarding a comparison of the local density approximation (LDA) and generalized gradient approximations (GGA), which we find to describe core-valence exchange-correlation markedly different. (1) Evaluating the binding properties of a number of typical solids we demonstrate that the pseudopotential approach and namely the linearization of core-valence exchange-correlation are both accurate and limited in the same way in GGA as in LDA. (2) Examining the practice to carry out GGA calculations using pseudopotentials derived within LDA we show that the ensuing results differ significantly from those obtained using pseudopotentials derived within GGA. As principal source of these differences we identify the distinct behavior of core-valence exchange-correlation in LDA and GGA which, accordingly, contributes substantially to the GGA induced changes of calculated binding properties.Comment: 13 pages, 6 figures, submitted to Phys. Rev. B, other related publications can be found at http://www.rz-berlin.mpg.de/th/paper.htm

Purification of chicken carbonic anhydrase isozyme-III (CA-III) and its measurement in White Leghorn chickens

<p>Abstract</p> <p>Background</p> <p>The developmental profile of chicken carbonic anhydrase-III (CA-III) blood levels has not been previously determined or reported. We isolated CA-III from chicken muscle and investigated age-related changes in the levels of CA-III in blood.</p> <p>Methods</p> <p>CA-III was purified from chicken muscle. The levels of CA-III in plasma and erythrocytes from 278 female chickens (aged 1-93 weeks) and 68 male chickens (aged 3-59 weeks) were determined by ELISA.</p> <p>Results</p> <p>The mean level of CA-III in female chicken erythrocytes (1 week old) was 4.6 μg/g of Hb, and the CA-III level did not change until 16 weeks of age. The level then increased until 63 weeks of age (11.8 μg/g of Hb), decreased to 4.7 μg/g of Hb at 73 weeks of age, and increased again until 93 weeks of age (8.6 μg/g of Hb). The mean level of CA-III in erythrocytes from male chickens (3 weeks old) was 2.4 μg/g of Hb, and this level remained steady until 59 weeks of age. The mean plasma level of CA-III in 1-week-old female chickens was 60 ng/mL, and this level was increased at 3 weeks of age (141 ng/mL) and then remained steady until 80 weeks of age (122 ng/mL). The mean plasma level of CA-III in 3-week-old male chickens was 58 ng/mL, and this level remained steady until 59 weeks of age.</p> <p>Conclusion</p> <p>We observed both developmental changes and sex differences in CA-III concentrations in White Leghorn (WL) chicken erythrocytes and plasma. Simple linear regression analysis showed a significant association between the erythrocyte CA-III level and egg-laying rate in WL-chickens 16-63 weeks of age (p < 0.01).</p