Posting versus Replying: The Effects of Instructor Participation in MOOC Discussion Forums

Previous research has suggested that the frequency of instructor participation in online discussion forums can affect student participation and subsequently their learning results in online courses. However , the different approaches of instructor participation and their effects have not been well studied, particularly in MOOCs of very large class sizes. This research investigates how instructor participation via posting vs. replying in online discussion forums affects student participation in MOOCs. Our results show that instructors mainly participate through replying rather than posting. However , instructor posting is more effective than instructor replying on enhancing student participation, and this advantage of instructor posting over replying increases with class size. Class size negatively moderates the positive effect of instructor replying, but not that of instructor posting. These findings implicate the necessity of a well-planned participation strategy for instructors to engage in MOOC discussion forums

Variation of Oriental Oak (Quercus variabilis) Leaf δ13C across Temperate and Subtropical China: Spatial Patterns and Sensitivity to Precipitation

The concentration of the carbon-13 isotope (leaf δ13C) in leaves is negatively correlated with the mean annual precipitation (MAP) atlarge geographical scales. In this paper, we explain the spatial pattern of leaf δ13C variation for deciduous oriental oak (Quercus variabilis Bl.) across temperate and subtropical biomes and its sensitivity to climate factors such as MAP. There was a 6‰ variation in the leaf δ13C values of oak with a significant positive correlation with latitude and negative correlations with the mean annual temperature (MAT) and MAP. There was no correlation between leaf δ13C and altitude or longitude. Stepwise multiple regression analyses showed that leaf δ13C decreased 0.3‰ per 100 mm increase in MAP. MAP alone could account for 68% of the observed variation in leaf δ13C. These results can be used to improve predictions for plant responses to climate change and particularly lower rainfall

THE DEVELOPMENT OF TRANSFORMATION AMBIDEXTERITY: A COMPARATIVE STUDY OF FOUR LEADING IT ORGANIZATIONS

Successful IT organizations are ones that can constantly transform themselves to adapt to the changing environment. Unlike the punctuated change in traditional organizations’ transformation, IT organizations’ transformation is often a continuous change where the existing and the new business coexist. The ability to simultaneous exploit the existing business while exploring the new business during organizational transformation, which we term transformation ambidexterity, has proven to a key success factor. This study intends to explore how IT organizations develop transformation ambidexterity. We conduct a comparative case study of four leading IT organizations that have just gone through a successful transformation and unveil four development approaches, namely partition, hybridization, self-extension, and self-generation. These four approaches are based on two primary dimensions of ambidexterity development: 1) development mechanism and 2) development path. We conclude with theoretical contributions to IS, organizational transformation and ambidexterity literature and with guidelines for IT and general managers to redeploy appropriate mechanisms and follow appropriate path for ambidexterity

La Nakim delle Nava Durgā di Bhaktapur

The Nakim ("married woman") of the Nava Durgā community of Bhaktapur (Nepal) performs sacred activities in the temple. She is the only female figure present in the Hindu religious communities of the newar society. Her hereditary role contradicts the social conventions that women are confined to domestic roles. There is no study of her role: the researches on Nava Durgā are focused on dance and masks. In the article I will examine the main tasks of Nakim, the ways in which her role is transmitted from generation to generation, the interdictions and questions concerning the relationship with the concepts of purity and impurity. The figure of Nakim includes apparently opposite characteristics: the subordinate condition to which she is subjected as a woman, and her status of community leader. Among her various roles, the most important one is to mediate between the sacred and the profane, which is comparable to that of the Vedic deities of Hinduism. Furthermore, her figure, as an inverse mirror of the divine figure of Nava Durgā (that is, of the nine wrathful manifestations of the goddess Durga), is the substantiation of the feminine for the Hindu religiosity.La Nakim (“donna sposata”) della comunità Nava Durgā di Bhaktapur (Nepal) svolge attività sacre nel tempio. È l’unica figura femminile presente nelle comunità religiose hindu della società newar. Il suo ruolo, ereditario, contraddice le convenzioni sociali che vedono le quali le donne confinate ai ruoli domestici. Non c’è uno studio che la riguardi: le ricerche sulle Nava Durgā sono concentrate sulla danza e sulle maschere. Nell’articolo ho preso in esame i compiti principali della Nakim, le vie e i modi con i quali viene trasmesso il suo ruolo di generazione in generazione, le interdizioni e le questioni relative al rapporto con i concetti di purezza e impurità. La figura della Nakim comprende caratteristiche apparentemente opposte: la condizione subalterna cui è soggetta in quanto donna, e la condizione di leader della comunità. Tra i suoi ruoli, il più importante è di mediatrice tra sacro e profano, che è paragonabile a quello delle divinità vediche dell’hinduismo. Inoltre la sua figura, in quanto rispecchiamento inverso della figura divina di Nava Durgā (cioè delle nove manifestazioni irate della dea Durgā), è per la religiosità hindu la sostanziazione del femminile

Antheraea pernyi silk: mechanical and thermal properties / by Shan Du

This project reveals the differences in the structure, mechanical and thermal properties from different parts of A. pernyi cocoon, as well as the adhesion between fibroin and sericin from A. pernyi. The structure-property relationship would help tailored design of fibres.<br /

Mass-concentration relation of clusters of galaxies from CFHTLenS

Based on weak lensing data from the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS), in this paper we study the mass-concentration ($M$-$c$) relation for $\sim 200$ redMaPPer clusters in the fields. We extract the $M$-$c$ relation by measuring the density profiles of individual clusters instead of using stacked weak lensing signals. By performing Monte Carlo simulations, we demonstrate that although the signal-to-noise ratio for each individual cluster is low, the unbiased $M$-$c$ relation can still be reliably derived from a large sample of clusters by carefully taking into account the impacts of shape noise, cluster center offset, dilution effect from member or foreground galaxies, and the projection effect. Our results show that within error bars the derived $M$-$c$ relation for redMaPPer clusters is in agreement with simulation predictions. There is a weak deviation in that the halo concentrations calibrated by Monte Carlo simulations are somewhat higher than that predicted from ${\it Planck}$ cosmology.Comment: Accepted for Publication in ApJ. 18 pages, 8 figures. Updated to match the published versio

Tumor Classification Using High-Order Gene Expression Profiles Based on Multilinear ICA

Motivation. Independent Components Analysis (ICA) maximizes the statistical independence of the representational components of a training gene expression profiles (GEP) ensemble, but it cannot distinguish relations between the different factors, or different modes, and it is not available to high-order GEP Data Mining. In order to generalize ICA, we introduce Multilinear-ICA and apply it to tumor classification using high order GEP. Firstly, we introduce the basis conceptions and operations of tensor and recommend Support Vector Machine (SVM) classifier and Multilinear-ICA. Secondly, the higher score genes of original high order GEP are selected by using t-statistics and tabulate tensors. Thirdly, the tensors are performed by Multilinear-ICA. Finally, the SVM is used to classify the tumor subtypes. Results. To show the validity of the proposed method, we apply it to tumor classification using high order GEP. Though we only use three datasets, the experimental results show that the method is effective and feasible. Through this survey, we hope to gain some insight into the problem of high order GEP tumor classification, in aid of further developing more effective tumor classification algorithms