Predicting Math Success in an Online Tutoring System Using Language Data and Click-Stream Variables: A Longitudinal Analysis

Previous studies have demonstrated strong links between students\u27 linguistic knowledge, their affective language patterns and their success in math. Other studies have shown that demographic and click-stream variables in online learning environments are important predictors of math success. This study builds on this research in two ways. First, it combines linguistics and click-stream variables along with demographic information to increase prediction rates for math success. Second, it examines how random variance, as found in repeated participant data, can explain math success beyond linguistic, demographic, and click-stream variables. The findings indicate that linguistic, demographic, and click-stream factors explained about 14% of the variance in math scores. These variables mixed with random factors explained about 44% of the variance

Reduced Levels of Membrane-Bound Alkaline Phosphatase Are Common to Lepidopteran Strains Resistant to Cry Toxins from Bacillus thuringiensis

Development of insect resistance is one of the main concerns with the use of transgenic crops expressing Cry toxins from the bacterium Bacillus thuringiensis. Identification of biomarkers would assist in the development of sensitive DNA-based methods to monitor evolution of resistance to Bt toxins in natural populations. We report on the proteomic and genomic detection of reduced levels of midgut membrane-bound alkaline phosphatase (mALP) as a common feature in strains of Cry-resistant Heliothis virescens, Helicoverpa armigera and Spodoptera frugiperda when compared to susceptible larvae. Reduced levels of H. virescens mALP protein (HvmALP) were detected by two dimensional differential in-gel electrophoresis (2D-DIGE) analysis in Cry-resistant compared to susceptible larvae, further supported by alkaline phosphatase activity assays and Western blotting. Through quantitative real-time polymerase chain reaction (qRT-PCR) we demonstrate that the reduction in HvmALP protein levels in resistant larvae are the result of reduced transcript amounts. Similar reductions in ALP activity and mALP transcript levels were also detected for a Cry1Ac-resistant strain of H. armigera and field-derived strains of S. frugiperda resistant to Cry1Fa. Considering the unique resistance and cross-resistance phenotypes of the insect strains used in this work, our data suggest that reduced mALP expression should be targeted for development of effective biomarkers for resistance to Cry toxins in lepidopteran pests

Chondroitin sulfates and their binding molecules in the central nervous system

Chondroitin sulfate (CS) is the most abundant glycosaminoglycan (GAG) in the central nervous system (CNS) matrix. Its sulfation and epimerization patterns give rise to different forms of CS, which enables it to interact specifically and with a significant affinity with various signalling molecules in the matrix including growth factors, receptors and guidance molecules. These interactions control numerous biological and pathological processes, during development and in adulthood. In this review, we describe the specific interactions of different families of proteins involved in various physiological and cognitive mechanisms with CSs in CNS matrix. A better understanding of these interactions could promote a development of inhibitors to treat neurodegenerative diseases

Damage prediction of carbon-epoxy composite laminates using finite element analysis

Continuous growth in the use of composite materials in advanced structural applications, such as aerospace, marine, and automotive, has been observed in the past two decades. This has motivated efficient design and manufacturing of composite products so as to obtain lighter structures with higher strength, durability and life. To contribute to develop an efficient design methodology, the present research has been undertaken. The accuracy and predictive capabilities of finite element models and failure analysis of a specific composite material using the commercial finite element program ABAQUS are evaluated. A set of unidirectional carbon-epoxy composite laminates are modelled under monotonic tensile and compressive loading, and their failure is assessed using the Hashin's failure criterion. The numerical results are compared against carefully conducted experimental test data. The differences between the experimental and numerically predicted values of the maximum principle stress are used to evaluate the accuracy of the finite element models. In the unidirectional (0-degree) composite laminates after the initial ply failure, a varied damage pattern is observed with a difference of 17.7% and 10.5% under tension and compression, respectively. The unidirectional composites under transverse loading (90-degree) show a difference of 10.8% and 0.4% under tensile and compressive loading, respectively. The variations between the experimental and the modelled results are mainly due to approximating and analysing the model in its 2D behaviour, which excludes delamination. Specifically, a composite tested under compression suffers from Brooming Gage Bottom (BGB); so the variation is expected. The Hashin's damage criterion is not suitable when delamination occurs as a dominant failure mode

Damage prediction of carbon-epoxy composites under shear loads using the finite element method

Carbon fiber reinforced polymer composite (CFRP) laminates are used in many applications of the aerospace industry, particularly, in aircraft structural components due to their good stiffness to weight ratios compared to traditionally used aluminium. The ability of accurate prediction of the structural response of composites under complex loadings is crucially important for high-end designs and optimisation of composite structures. The accuracy and predictive capabilities of finite element models in the failure analysis of the carbon-epoxy (IM7/977-3) composite laminates have been evaluated. The cross ply composite laminate with the layup configuration [0,90]4S was numerically modelled under shear loads, and the commercial finite element program ABAQUS was utilised. The failure due to shear loads were analysed using the Hashin's failure criterion. The numerical results were validated by comparing them against the carefully conducted experimental test data. The difference between the experimental and numerically predicted values of the stress and strain were compared to evaluate the accuracy of the finite element models

Nanocarrier-Mediated Inhibition of Macrophage Migration Inhibitory Factor Attenuates Secondary Injury after Spinal Cord Injury

Spinal cord injury (SCI) can lead to permanent motor and sensory deficits. Following the initial traumatic insult, secondary injury mechanisms characterized by persistent heightened inflammation are initiated and lead to continued and pervasive cell death and tissue damage. Anti-inflammatory drugs such as methylprednisolone (MP) used clinically have ambiguous benefits with debilitating side effects. Typically, these drugs are administered systemically at high doses, resulting in toxicity and paradoxically increased inflammation. Furthermore, these drugs have a small time window postinjury (few hours) during which they need to be infused to be effective. As an alternative to MP, we investigated the effect of a small molecule inhibitor (Chicago sky blue, CSB) of macrophage migration inhibitory factor (MIF) for treating SCI. The pleiotropic cytokine MIF is known to contribute to upregulation of several pro-inflammatory cytokines in various disease and injury states. <i>In vitro</i>, CSB administration alleviated endotoxin-mediated inflammation in primary microglia and macrophages. Nanocarriers such as liposomes can potentially alleviate systemic side effects of high-dose therapy by enabling site-specific drug delivery to the spinal cord. However, the therapeutic window of 100 nm scale nanoparticle localization to the spinal cord after contusion injury is not fully known. Thus, we first investigated the ability of nanocarriers of different sizes to localize to the injured spinal cord up to 2 weeks postinjury. Results from the study showed that nanocarriers as large as 200 nm in diameter could extravasate into the injured spinal cord up to 96 h postinjury. We then formulated nanocarriers (liposomes) encapsulating CSB and administered them intravenously 48 h postinjury, within the previously determined 96 h therapeutic window. <i>In vivo</i>, in this clinically relevant contusion injury model in rats, CSB administration led to preservation of vascular and white matter integrity, improved wound healing, and an increase in levels of arginase and other transcripts indicative of a resolution phase of wound healing. This study demonstrates the potential of MIF inhibition in SCI and the utility of nanocarrier-mediated drug delivery selectively to the injured cord

Scoping the Emerging Field of Quantitative Ethnography: Opportunities, Challenges and Future Directions

Quantitative Ethnography (QE) is an emerging methodological approach that combines ethnographic and statistical tools to analyze both Big Data and smaller data to study human behavior and interactions. This paper presents a methodological scoping review of 60 studies employing QE approaches with an intention to characterize and establish where the boundaries of QE might and should be in order to establish the identity of the field. The key finding is that QE researchers have enough commonality in their approach to the analysis of human behavior with a strong focus on grounded analysis, the validity of codes and consistency between quantitative models and qualitative analysis. Nonetheless, in order to reach a larger audience, the QE community should attend to a number of conceptual and methodological issues (e.g. interpretability). We believe that the strength of work from individual researchers reported in this review and initiatives such as the recently established International Society for Quantitative Ethnography (ISQE) can present a powerful force to shape the identity of the QE communit