Leading within the middle: Perspectives on middle leadership in secondary school improvement

This study provides an investigative and analytical view of the social and political processes occurring within the implementation of a system initiated and resourced, secondary school improvement initiative (SSII) in a Catholic urban school system in a capital city on the East coast of Australia. The SSII follows a tiered model of implementation within a local school system [in this case, the MacKillop Catholic School System, (MCSS)] and its schools through a group of school-based middle-level leaders, the School Improvement Middle Leaders (SIMLs). This thesis is a six-site case study. The lens of symbolic interactionism is adopted as the theoretical perspective and multiple-site case study adopted as the methodology. It explores the experiences of SIMLs working within the SSII reform initiative across the MCSS to investigate influences of the SSII on the interactions occurring within each school and the school system structures. Successful reform is about creating the conditions, which enable teachers to change and improve their practice. Models of school reform can adopt two views. The inside view of school reform focuses on the capacity of a school to transform itself. Teacher learning is crucial, and school conditions need to foster that learning. This type of model can be described as “bottom up”. An outside view of school reform is one involving the implementation of externally-developed initiatives. A model in which innovations and practices developed by policy-makers and then transferred to multiple settings (“scaling up”) can be described as “top-down”. The SSII is an example of a blended “top down” and “bottom up” initiative in secondary schools. This multiple site case study uses individual, semi-structured interviews and an online survey instrument, to gather the participants’ perspectives on the numerous, different experiences that occur in six secondary schools as a result of the implementation of this school improvement initiative. The central findings of the study are reflected in a proposed model, which describes the conditions that enable a school improvement middle leader within a school to support teachers and facilitate an improvement in their practice. This study serves to highlight the complexities that occur within the school reform agendas in systems and secondary schools, and the pressures placed on middle leaders charged with the responsibility of leading an initiative within their unique school context. The complex nature of secondary schools and how they operate within a school system means any new initiatives are challenged, situated and adopted within the existing established hierarchies of these organisations. Exploring these complexities assists in understanding the nature of school change, social interactions, and the concept of middle leadership within the unique and common features of urban secondary schools

The role of lipid and lipoprotein metabolism in non-alcoholic fatty liver disease

Due to the epidemic of obesity across the world, nonalcoholic fatty liver disease (NAFLD) has become one of the most prevalent chronic liver disorders in children and adolescents. NAFLD comprises a spectrum of fat-associated liver conditions that can result in end-stage liver disease and the need for liver transplantation. Simple steatosis, or fatty liver, occurs early in NAFLD and may progress to nonalcoholic steatohepatitis, fibrosis and cirrhosis with increased risk of hepatocellular carcinoma. The mechanism of the liver injury in NAFLD is currently thought to be a multiple-hit process where the first hit is an increase in liver fat, followed by multiple additional factors that trigger the inflammatory activity. At the onset of disease, NAFLD is characterized by hepatic triglyceride accumulation and insulin resistance. Liver fat accumulation is associated with increased lipotoxicity from high levels of free fatty acids, free cholesterol and other lipid metabolites. As a consequence, mitochondrial dysfunction with oxidative stress and production of reactive oxygen species and endoplasmic reticulum stress-associated mechanisms, are activated. The present review focuses on the relationship between intra-cellular lipid accumulation and insulin resistance, as well as on lipid and lipoprotein metabolism in NAFLD

Exchange-coupling in thermal annealed bimagnetic core/shell nanoparticles

In this study we demonstrate that the effective coupling of the magnetic phases in core/shell nanoparticles can be promoted by an appropriate thermal annealing. In this way, the magnetization thermal stability of the hard ferrimagnetic CoFe2O4 oxide can be increased up to room temperature when coupled to a CoO antiferromagnetic core in an inverse core/shell structure. In addition, the results show that, being encapsulated in a ∼2 nm thick CoFe2O4 shell, the CoO core is successfully protected against oxidation which is crucial for the effectiveness of the magnetic coupling at the interface.Fil: Lavorato, Gabriel Carlos. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lima, Enio Junior. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Troiani, Horacio Esteban. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Zysler, Roberto Daniel. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Winkler, Elin Lilian. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Preparation and Characterization of Master Alloys Fe48Cr15Mo14C15B6Y2 Metallic Glasses

The purpose of this work is the characterization of a master alloy of metal glass based on iron Fe48Cr15Mo14C15B6Y2. Two types of alloys studied B1 which has been prepared by the use of pure element and the other B2 which has been prepared by the use of raw materials. The thermal and structural properties of the samples are measured by a combination of high temperature differential scanning calorimeter (HTDSC), X-ray diffraction and scanning electron microscopy (SEM). Chemical compositions are checked by energy dispersive spectroscopy analysis.Fil: Bendjemil, Badis. University of Badji -Mokhtar; Argelia. Faculty of Sciences and Technology; ArgeliaFil: Seghairi, Nassima. Faculty of Sciences and Technology; ArgeliaFil: Lavorato, Gabriel Carlos. Dipa rtimento di Chimica Universita' di Torino; Italia. Comisión Nacional de Energía Atómica. Gerencia del Área Investigaciones y Aplicaciones no Nucleares; ArgentinaFil: Castellero, Alberto. Dipa rtimento di Chimica Universita' di Torino; ItaliaFil: Bougdira, Jamal. Université de Nancy, Faculté des Sciences et. Techniques; FranciaFil: Vinai, Franco. Instituto Nazionale di Ricerca Metrologica; ItaliaFil: Baricco, Marcello. Dipa rtimento di Chimica Universita' di Torino; Itali

Bifunctional CoFe2O4/ZnO Core/Shell Nanoparticles for Magnetic Fluid Hyperthermia with Controlled Optical Response

Conjugation of optical and magnetic responses in a unique system at the nanoscale emerges as a powerful tool for several applications. Here, we fabricated bifunctional CoFe2O4-core/ZnO-shell nanoparticles with simultaneous photoluminescence in the visible range and ac magnetic losses suitable for hyperthermia. The structural characterization confirms that the system is formed by a ≈7 nm CoFe2O4 core encapsulated in a ≈1.5-nm-thick semiconducting ZnO shell. As expected from its high anisotropy, the magnetic losses in an ac magnetic field are dominated by the Brown relaxation mechanism. The ac magnetic response of the core/shell system can be accurately predicted by the linear response theory and differs from that one of bare CoFe2O4 nanoparticles as a consequence of changes in the viscous relaxation process due to the effect of the magnetostatic interactions. Concerning the optical properties, by comparing core/shell CoFe2O4/ZnO and single-phase ZnO nanoparticles, we found that the former exhibits a broader optical absorption and photoluminescence, both shifted to the visible range, indicating that the optical properties are closely associated with the shell-morphology of ZnO. Being focused on bifunctional nanoparticles with an optical response in the visible range and a tunable hyperthermia output, our results can help to address current open questions on magnetic fluid hyperthermia.Fil: Lavorato, Gabriel Carlos. Centro Brasileiro de Pesquisas Físicas; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Lima, Enio Junior. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Vasquez Mansilla, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Troiani, Horacio Esteban. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Zysler, Roberto Daniel. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Winkler, Elin Lilian. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentin

De novo reconstitution reveals the proteins required for skeletal muscle voltage-induced Ca2+ release

Skeletal muscle contraction is triggered by Ca2+ release from the sarcoplasmic reticulum (SR) in response to plasma membrane (PM) excitation. In vertebrates, this depends on activation of the RyR1 Ca2+ pore in the SR, under control of conformational changes of CaV1.1, located ∼12 nm away in the PM. Over the last ∼30 y, gene knockouts have revealed that CaV1.1/RyR1 coupling requires additional proteins, but leave open the possibility that currently untested proteins are also necessary. Here, we demonstrate the reconstitution of conformational coupling in tsA201 cells by expression of CaV1.1, β1a, Stac3, RyR1, and junctophilin2. As in muscle, depolarization evokes Ca2+ transients independent of external Ca2+ entry and having amplitude with a saturating dependence on voltage. Moreover, freeze-fracture electron microscopy indicates that the five identified proteins are sufficient to establish physical links between CaV1.1 and RyR1. Thus, these proteins constitute the key elements essential for excitation-contraction coupling in skeletal muscle