Identifying Teacher, School and District Characteristics Associated with Elementary Teachers' Use of Technology:A Multilevel Perspective

Over the past decade, investment in technology for schools has increased at a dramatic rate. Although policy makers are eager to understand the ways in which technology use in schools is affecting student learning, we believe that a critical preliminary step toward assessing the impacts of technology on teaching and learning requires the examination of the varied uses of technology in schools as well as the contexts that are likely to affect the use of technology in the classroom as a teaching and learning tool. Previous research examining technology use has focused on teacher characteristics and has neglected to explore the potentially alterable, organizational characteristics that may be affecting the adoption and use of technology in the classroom. In light of this argument and using survey data collected from 1490 elementary classroom teachers in 96 schools in 22 Massachusetts districts, this research examines how technology is being used by elementary school teachers, and examines the school and district organizational characteristics that are associated with increased use of technology as a teaching and learning tool. In addition to examining technology-use as a multi-faceted construct, using multilevel regression techniques this study provides evidence that schools’ organizational characteristics are associated with teachers’ use of technology in the classroom. Organizational characteristics such as districts’ and schools’ leadership practices and emphasis on technology, the type and amount of technology-related professional development available to teachers, as well as the amount of technology-related restrictive policies in place were found to be associated with the four measures of teachers’ use of technology examined in this study. Individual teacher characteristics such as constructivist beliefs, higher confidence using technology and positive beliefs about the efficacy of technology were each found to be associated with increased use of technology in the classroom

Influence of Maternal Glycemia on Intrauterine Fetal Adiposity Distribution after a Normal Oral Glucose Tolerance Test at 28 Weeks Gestation

Objective. To examine the relationship between maternal glucose levels and intrauterine fetal adiposity distribution in women with a normal oral glucose tolerance test (OGTT) at 28 weeks gestation. Study Design. We recruited 231 women with a singleton pregnancy. At 28 and 37 weeks gestation, sonographic measurements of fetal body composition were performed. Multiple regression analysis was used to study the influence of different maternal variables on fetal adiposity distribution. Results. Maternal glucose levels correlated with the fetal abdominal subcutaneous tissue measurements (r = 0.2; P = 0.014) and with birth weight (r = 0.1; P = 0.04). Maternal glucose levels did not correlate with the fetal mid-thigh muscle thickness and mid-thigh subcutaneous tissue measurements. Conclusion. We found that in nondiabetic women maternal glucose levels not only influence fetal adiposity and birth weight, but also influence the distribution of fetal adiposity. This supports previous evidence that maternal glycemia is a key determinant of intrauterine fetal programming

Septic shock is correlated with asymmetrical dimethyl arginine levels, which may be influenced by a polymorphism in the dimethylarginine dimethylaminohydrolase II gene: a prospective observational study

INTRODUCTION: Asymmetrical dimethyl arginine (ADMA) is an endogenous non-selective inhibitor of nitric oxide synthase that may influence the severity of organ failure and the occurrence of shock secondary to an infectious insult. Levels may be genetically determined by a promoter polymorphism in a regulatory gene encoding dimethylarginine dimethylaminohydrolase II (DDAH II), which functions by metabolising ADMA to citrulline. The aim of this study was to examine the association between ADMA levels and the severity of organ failure and shock in severe sepsis and also to assess the influence of a promoter polymorphism in DDAH II on ADMA levels. METHODS: A prospective observational study was designed, and 47 intensive care unit (ICU) patients with severe sepsis and 10 healthy controls were enrolled. Serum ADMA and IL-6 were assayed on admission to the ICU and seven days later. Allelic variation for a polymorphism at position -449 in the DDAH II gene was assessed in each patient. Clinical and demographic details were also collected. RESULTS: On day 1 more ADMA was detectable in the ICU group than in the control group (p = 0.005). Levels subsequently increased during the first week in ICU (p = 0.001). ADMA levels were associated with vasopressor requirements on day one (p = 0.001). ADMA levels and Sequential Organ Failure Assessment scores were directly associated on day one (p = 0.0001) and day seven (p = 0.002). The degree of acidaemia and lactaemia was directly correlated with ADMA levels at both time points (p < 0.01). On day seven, IL-6 was directly correlated with ADMA levels (p = 0.006). The variant allele with G at position -449 in the DDAH II gene was associated with increased ADMA concentrations at both time points (p < 0.05). CONCLUSION: Severity of organ failure, inflammation and presence of early shock in severe sepsis are associated with increased ADMA levels. ADMA concentrations may be influenced by a polymorphism in the DDAH II gene

Features of postoperative immune suppression are reversible with interferon gamma and independent of interleukin-6 pathways

OBJECTIVE The aim of this study was to evaluate the role of interleukin (IL)-6 pathways in postoperative immune suppression and to assess the reversibility of this phenomenon. BACKGROUND The postoperative period is characterized by increased IL-6 production and features of immune suppression. In vitro, IL-6 mediates anti-inflammatory effects through inhibition of interferon gamma (IFN-γ) pathways. The significance of the immunomodulatory effects of IL-6 in the clinical setting of postoperative immune suppression remains unclear. METHODS Patients over 45 years old undergoing elective surgery, involving the gastrointestinal tract, were recruited. IL-6 levels were assayed using an enzyme linked immunosorbent assay preoperatively, and at 24 and 48 hours. Peripheral blood mononuclear cells from healthy volunteers were cultured in perioperative serum and CD14Human Leukocyte Antigen-DR (HLA-DR) [monocyte HLA-DR (mHLA-DR)] geometric mean florescent intensity was measured in the presence and absence of IL-6 neutralizing antibody and recombinant IFN-γ. RESULTS Of the 108 patients, 41 developed a postoperative infection. The IL-6 levels increased 19-fold from the preoperative sample to 24 hours postoperatively (P < 0.0001). Higher IL-6 levels at 24 (P = 0.0002) and 48 hours (P = 0.003) were associated with subsequent postoperative infectious complications. mHLA-DR mean florescent intensity fell when healthy peripheral blood mononuclear cells were cultured with postoperative serum compared with preoperative serum (P = 0.008). This decrease was prevented by the presence of IFN-γ in the culture media, but not by the presence of IL-6-neutralizing antibody. CONCLUSIONS IL-6 levels increase after a major surgery and are associated with an increased susceptibility to postoperative infections. Serum obtained from postoperative patients induces an immunosuppressive response, reflected in reduced mHLA-DR levels, mediated through IL-6 independent pathways and is reversible with IFN-γ. These data may have therapeutic implications for the prevention of infection in patients undergoing major surgery

Three-dimensionally ordered hierarchically porous tin dioxide inverse opals and immobilization of palladium nanoparticles for catalytic applications

A high surface area 3D ordered SnO2 inverted opal with walls composed of interconnected nanocrystals is reported using a facile approach with tin acetate precursors. The hierarchically porous structure exhibits porosity on multiple lengths scales (cm down to nm). The thickness of the IO wall structure comprising nanocrystals of the oxide can be tuned by multiple infilling of the precursor. Using highly monodisperse Pd nanoparticles, we show how the SnO2 IO can be functionalized with immobilized Pd NP assemblies. We show that the Pd NP size dispersion is controlled by utilizing weak ligand–metal interactions and strong metal-oxide interactions for the immobilization step. The resulting SnO2–Pd IOs were investigated X-ray photoelectron spectroscopy indicating electronic interactions between the Pd and SnO2 and alterations to NP surface chemistry. Pd NPs assembled with excellent dispersion on the ordered SnO2 IOs show superior catalytic performance for liquid phase chemical synthesis via Suzuki coupling reactions and allow easy removal of the catalyst substrate post reaction. Higher mass electrocatalytic activity is also demonstrated for formic acid oxidation, compared to commercial Pd/C catalysts, which is shown to be due to better access to the catalytically active sites on SnO2–Pd IOs. The high surface area interconnected phase-pure SnO2 IO, with programmable porosity forms a functional material for catalytic applications

Alkane and alkanethiol passivation of halogenated Ge nanowires

The ambient stability and surface coverage of halogen (Cl, Br, and I) passivated germanium nanowires were investigated by X-ray photoelectron and X-ray photoelectron emission spectroscopy. After exposure to air for 24 h, the stability of the halogen-terminated Ge nanowire surfaces toward reoxidation was found to improve with the increasing size of the halogen atoms, i.e., I > Br > Cl. Halogen termination was effective in removing the native Ge oxide (GeOx) and could also be utilized for further functionalization. Functionalization of the halogenated Ge nanowires was investigated using alkyl Grignard reagents and alkanethiols. The stability of the alkyl and alkanethiol passivation layers from the different halogen-terminated surfaces was investigated by X-ray photoelectron spectroscopy and attenuated total reflectance infrared spectroscopy. Alkanethiol functionalized nanowires showed greater resistance against reoxidation of the Ge surface compared to alkyl functionalization when exposed to ambient conditions for 1 week

Formation mechanism of metal–molecule–metal junctions: molecule-assisted migration on metal defects

Activation energies, Ea, measured from molecular exchange experiments are combined with atomic-scale calculations to describe the migration of bare Au atoms and Au–alkanethiolate species on gold nanoparticle surfaces during ligand exchange for the creation of metal–molecule–metal junctions. It is well-known that Au atoms and alkanethiol–Au species can diffuse on gold with sub-1 eV barriers, and surface restructuring is crucial for self-assembled monolayer (SAM) formation for interlinking nanoparticles and in contacting nanoparticles to electrodes. In the present work, computer simulations reveal that naturally occurring ridges and adlayers on Au(111) are etched and resculpted by migration of alkanethiolate–Au species toward high coordination kink sites at surface step edges. The calculated energy barrier, Eb, for diffusion via step edges is 0.4–0.7 eV, close to the experimentally measured Ea of 0.5–0.7 eV. By contrast, putative migration from isolated nine-coordinated terrace sites and complete Au unbinding from the surface incur significantly larger barriers of +1 and +3 eV, respectively. Molecular van der Waals packing energies are calculated to have negligible effect on migration barriers for typically used molecules (length < 2.5 nm), indicating that migration inside SAMs does not change the size of the migration barrier. We use the computational methodology to propose a means of creating Au nanoparticle arrays via selective replacement of citrate protector molecules by thiocyanate linker molecules on surface step sites. This work also outlines the possibility of using Au/Pt alloys as possible candidates for creation of contacts that are well-formed and long-lived because of the superior stability of Pt interfaces against atomic migration

Expression of hereditary hemochromatosis C282Y HFE protein in HEK293 cells activates specific endoplasmic reticulum stress responses

<p>Abstract</p> <p>Background</p> <p>Hereditary Hemochromatosis (HH) is a genetic disease associated with iron overload, in which individuals homozygous for the mutant C282Y <it>HFE </it>associated allele are at risk for the development of a range of disorders particularly liver disease. Conformational diseases are a class of disorders associated with the expression of misfolded protein. HFE C282Y is a mutant protein that does not fold correctly and consequently is retained in the Endoplasmic Reticulum (ER). In this context, we sought to identify ER stress signals associated with mutant C282Y HFE protein expression, which may have a role in the molecular pathogenesis of HH.</p> <p>Results</p> <p>Vector constructs of Wild type HFE and Mutant C282Y HFE were made and transfected into HEK293 cell lines. We have shown that expression of C282Y HFE protein triggers both an unfolded protein response (UPR), as revealed by the increased GRP78, ATF6 and CHOP expression, and an ER overload response (EOR), as indicated by NF-κB activation. Furthermore, C282Y HFE protein induced apoptotic responses associated with activation of ER stress. Inhibition studies demonstrated that tauroursodeoxycholic acid, an endogenous bile acid, downregulates these events. Finally, we found that the co-existence of both C282Y HFE and Z alpha 1-antitrypsin protein (the protein associated with the liver disease of Z alpha 1-antitrypsin deficiency) expression on ER stress responses acted as potential disease modifiers with respect to each other.</p> <p>Conclusion</p> <p>Our novel observations suggest that both the ER overload response (EOR) and the unfolded protein response (UPR) are activated by mutant C282Y HFE protein.</p