UNIVERSAL DESIGN FOR LEARNING IN ONLINE CREDIT RECOVERY: DO COURSE FEATURES IMPACT ACHIEVEMENT?

This experimental study investigated whether the addition of course features based on the Universal Design for Learning (UDL) framework impacted achievement in an online English 1A credit recovery course offered by a state virtual school in the Western United States. An alternative format for completing course mastery assignments and eText support tools (ReadSpeaker and TextAid) were added to an existing version of the course. Writing prompts were also included in the alternative mastery assignments. Credit recovery students were randomly enrolled by school personnel into control and treatment sections of the English 1A courses using the enrollment mechanism of the school’s Student Information System (SIS). Out of the enrolled students approved to participate in the study (n=133/157), the control section had 68 enrollments, and the treatment section had 65 enrollments. Experimental data was gathered via pre-test, post-test scores on the four end of module tests. Course grade and final grade data was also provided through the Learning Management System (LMS) and SIS and analyzed using Independent Samples T-Tests. The state Office of Public Instruction provided demographic information on participants. Surveys were used to gather qualitative and quantitative data on the learning experience, and the course instructor was interviewed on perceptions of the course participants, UDL course features and the student learning experience. Results from the experimental aspect of the study demonstrated the null hypothesis could not be rejected. Mean score gain differences on pre-test, post-test scores were not statistically significant or important across control and treatment groups. Course grade and final grade data also did not demonstrate a statistically significant or important difference in achievement across the groups. Passing rates were higher in the treatment group than the control group (9% based on enrollment numbers, and 5% for individuals). Results from the open-ended survey questions and qualitative interviews revealed three key themes: 1) appreciation of the mastery assignment options 2) the importance of instructor/course mentor support 3) and the initial time commitment of working with the new assignment type for the instructor. Results indicated that an incremental approach to including UDL course features did not result in a statistically significant impact on student achievement. However, the results suggest that a more robust development of the learning experience based on Universal Design for Learning principles may be more likely to increase the impact on student achievement in the courses. The importance of local support on student achievement was also observed. Future research, therefore, might consider a more substantial redesign of the learning experience based on Universal Design for Learning principles as well as additional influences associated with individual engagement and the local learning environment. In addition, it was suggested that researchers also continue to investigate administrative and instructional efficacy when redesigning online credit recovery courses based on UDL principles

Schematic Models for Active Nonlinear Microrheology

We analyze the nonlinear active microrheology of dense colloidal suspensions using a schematic model of mode-coupling theory. The model describes the strongly nonlinear behavior of the microscopic friction coefficient as a function of applied external force in terms of a delocalization transition. To probe this regime, we have performed Brownian dynamics simulations of a system of quasi-hard spheres. We also analyze experimental data on hard-sphere-like colloidal suspensions [Habdas et al., Europhys. Lett., 2004, 67, 477]. The behavior at very large forces is addressed specifically

Visfatin reduces gap junction mediated cell-to-cell communication in proximal tubule-derived epithelial cells

Background/Aims: In the current study we examined if the adipocytokine, visfatin, alters connexin-mediated intercellular communication in proximal tubule-derived epithelial cells. Methods: The effects of visfatin (10-200ng/mL) on cell viability and cytotoxicity in HK2-cells were assessed by MTT, crystal violet and lactate dehydrogenase assays. Western blot analysis was used to confirm expression of Cx26, Cx40 and Cx43. The effect of visfatin (10-200ng/mL) on TGF-β1 secretion was confirmed by ELISA, and the effects of both TGF-β1 (2-10ng/mL) and visfatin (10-200ng/mL) on connexin expression were assessed by western blot. Functional intercellular communication was determined using transfer of Lucifer Yellow and paired-whole cell patch clamp electrophysiology. Results: In low glucose (5mM), visfatin (10-200ng/mL) did not affect membrane integrity, cytotoxicity or cell viability at 48hrs, but did evoke a concentration-dependent reduction in Cx26 and Cx43 expression. The expression of Cx40 was unaffected. At 48hrs, visfatin (10-200ng/mL) increased the secretion of TGF-β1 and the visfatin-evoked changes in connexin expression were mimicked by exogenous application of the pro-fibrotic cytokine (2-10ng/ml). Visfatin reduced dye transfer between coupled cells and decreased functional conductance, with levels falling by 63% as compared to control. Although input resistance was increased following visfatin treatment by 166%, the change was not significant as compared to control. The effects of visfatin on Cx-expression and cell-coupling were blocked in the presence of a TGF-β1 specific neutralizing antibody. Conclusions: The adipocytokine visfatin selectively evoked a non-toxic reduction in connexin expression in HK2-cells. The loss in gap-junction associated proteins was mirrored by a loss in functional conductance between coupled cells. Visfatin increased TGF-β secretion and the pattern of change for connexins expression was mimicked by exogenous application of TGF-β1. The effect of visfatin on Cx-expression and dye transfer were negated in the presence of a TGF-β1 neutralising antibody. These data suggest that visfatin reduces connexin-mediated intercellular communication in proximal tubule-derived epithelial cells via a TGF-β dependent pathway. © 2013 S. Karger AG, Base

Brane Universe and Multigravity: Modification of gravity at large and small distances

We consider a modification of gravity at large distances in a Brane Universe which was discussed recently. In these models the modification of gravity at large distances is ultimately connected to existence of negative tension brane(s) and exponentially small tunneling factor. We discuss a general model which interpolates between Bi-gravity model and GRS model. We also discuss the possible mechanism of stabilization for negative tension branes in AdS background. Finally we show that extra degrees of freedom of massive gravitons do not lead to disastrous contradiction with General Relativity if the stabilization condition $\int dy \sqrt{-G^{(5)}} (T^\mu_\mu-2T^5_5)=0$ is implemented.Comment: 12 pages, 4 eps figures, LaTe

Interfacial rheology and direct imaging reveal domain-templated network formation in phospholipid monolayers penetrated by fibrinogen

Phospholipids are found throughout the natural world, including the lung surfactant (LS) layer that reduces pulmonary surface tension and enables breathing. Fibrinogen, a protein involved in the blood clotting process, is implicated in LS inactivation and the progression of disorders such as acute respiratory distress syndrome. However, the interaction between fibrinogen and LS at the air-water interface is poorly understood. Through a combined microrheological, confocal and epifluorescence microscopy approach we quantify the interfacial shear response and directly image the morphological evolution when a model LS monolayer is penetrated by fibrinogen. When injected into the subphase beneath a monolayer of the phospholipid dipalmitoylphosphatidylcholine (DPPC, the majority component of LS), fibrinogen preferentially penetrates disordered liquid expanded (LE) regions and accumulates on the boundaries between LE DPPC and liquid condensed (LC) DPPC domains. Thus, fibrinogen is line active. Aggregates grow from the LC domain boundaries, ultimately forming a percolating network. This network stiffens the interface compared to pure DPPC and imparts the penetrated monolayer with a viscoelastic character reminiscent of a weak gel. When the DPPC monolayer is initially compressed beyond LE-LC coexistence, stiffening is significantly more modest and the penetrated monolayer retains a viscous-dominated, DPPC-like character

Models of Party Democracy : Patterns of Party Regulation in Post-War European Constitutions

This article investigates the ways in which political parties are codified in modern democratic constitutions, providing a unique cross-sectional and longitudinal overview of the patterns of party constitutionalization in post-war Europe. Although the constitutions of western liberal democracies traditionally have paid little attention to the role of parties, evidence suggests that in contemporary democracies, both old and new, they are increasingly accorded a formal constitutional status. Little is known, however, about the substantive content of their constitutional position or about the normative connotations of their constitutional codification. In this article, we demonstrate that there is a clear correlation between the nature and the intensity of party constitutionalization and the newness and historical experience of democracy and that, with time, the constitutional regulation of the extra-parliamentary organization and the parties’ rights and duties has gained in importance at the expense of their parliamentary and electoral roles. The analysis furthermore suggests that three distinct models of party constitutionalization can be identified – Defending Democracy, Parties in Public Office, and Parties as Public Utilities – each of which is related to a particular conception of party democracy

Inverted organic photovoltaics with a solution-processed ZnO/MgO electron transport bilayer

Electron transport layers (ETLs) have been instrumental in breaking the efficiency boundaries of solution-processed photovoltaics. In particular, bilayer ETLs with an MgO top component have afforded tremendous success in various solution-processed systems, such as perovskite photovoltaics, however, their application in the promising technology of organic photovoltaics is limited. In this work, we fabricate organic photovoltaic devices incorporating a “bilayer” ZnO/MgO ETL instead of a single ZnO ETL, so as to reduce the leakage current and boost the power conversion efficiency. The ZnO/MgO ETL is shown to have a more uniform top surface and a lower work function compared to the single ZnO ETL which is expected to be beneficial to electron extraction. Furthermore, we demonstrate that insertion of the thin (≲ 10 nm) MgO interlayer in devices leads to a reduced leakage current and an increase in the shunt resistance. Application of the MgO interlayer boosts the short circuit current density and fill factor, and enhances the power conversion efficiency by ∼10% (relative increase) thereby demonstrating a facile approach to push the efficiency of organic photovoltaics to higher levels

MicroLib: A library of 3D microstructures generated from 2D micrographs using SliceGAN

3D microstructural datasets are commonly used to define the geometrical domains used in finite element modelling. This has proven a useful tool for understanding how complex material systems behave under applied stresses, temperatures and chemical conditions. However, 3D imaging of materials is challenging for a number of reasons, including limited field of view, low resolution and difficult sample preparation. Recently, a machine learning method, SliceGAN, was developed to statistically generate 3D microstructural datasets of arbitrary size using a single 2D input slice as training data. In this paper, we present the results from applying SliceGAN to 87 different microstructures, ranging from biological materials to high-strength steels. To demonstrate the accuracy of the synthetic volumes created by SliceGAN, we compare three microstructural properties between the 2D training data and 3D generations, which show good agreement. This new microstructure library both provides valuable 3D microstructures that can be used in models, and also demonstrates the broad applicability of the SliceGAN algorithm

Inverted organic photovoltaics with a solution-processed ZnO/MgO electron transport bilayer

Electron transport layers (ETLs) have been instrumental in breaking the efficiency boundaries of solution-processed photovoltaics. In particular, bilayer ETLs with an MgO top component have afforded tremendous success in various solution-processed systems, such as perovskite photovoltaics, however, their application in the promising technology of organic photovoltaics is limited. In this work, we fabricate organic photovoltaic devices incorporating a “bilayer” ZnO/MgO ETL instead of a single ZnO ETL, so as to reduce the leakage current and boost the power conversion efficiency. The ZnO/MgO ETL is shown to have a more uniform top surface and a lower work function compared to the single ZnO ETL which is expected to be beneficial to electron extraction. Furthermore, we demonstrate that insertion of the thin (≲ 10 nm) MgO interlayer in devices leads to a reduced leakage current and an increase in the shunt resistance. Application of the MgO interlayer boosts the short circuit current density and fill factor, and enhances the power conversion efficiency by ∼10% (relative increase) thereby demonstrating a facile approach to push the efficiency of organic photovoltaics to higher levels