212 research outputs found

    Unsupervised Learning for Understanding Student Achievement in a Distance Learning Setting

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    Many factors could affect the achievement of students in distance learning settings. Internal factors such as age, gender, previous education level and engagement in online learning activities can play an important role in obtaining successful learning outcomes, as well as external factors such as regions where they come from and the learning environment that they can access. Identifying the relationships between student characteristics and distance learning outcomes is a central issue in learning analytics. This paper presents a study that applies unsupervised learning for identifying how demographic characteristics of students and their engagement in online learning activities can affect their learning achievement. We utilise the K-Prototypes clustering method to identify groups of students based on demographic characteristics and interactions with online learning environments, and also investigate the learning achievement of each group. Knowing these groups of students who have successful or poor learning outcomes can aid faculty for designing online courses that adapt to different students' needs. It can also assist students in selecting online courses that are appropriate to them

    How do Plants Respond to Grazing at a Molecular Level?

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    Grazing is a multiple-component process that includes wounding, defoliation, and saliva depositing. The molecular mechanism for how plants respond to grazing in grassland is a new topic. To address this question, we performed gene expression activities within 2 to 24 hours of grazing and proteomics analysis of rice seedling, examining hundreds of genes and proteins. Some key genes in GeneChips analysis specifically researched were β-amylase, LcSUT1, LcDREB3, and FEH gene. BSA (bovine serum albumin), an important and abundant component in saliva was used to study the saliva-plant interaction in grazing. Combined with corresponding gene and grazing research by other laboratories, this will advance our knowledge of the molecular interface of the grass-herbivore interaction

    A Knowledge Framework for Information Security Modeling

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    The data collection process for risk assessment highly depends on the security experience of security staffs of an organization. It is difficult to have the right information security staff, who understands both the security requirements and the current security state of an organization and at the same time possesses the skill to perform risk assessment. However, a well defined knowledge model could help to describe categories of knowledge required to guide the data collection process. In this paper, a knowledge framework is introduced, which includes a knowledge model to define the data skeleton of the risk environment of an organization and security patterns about relationships between threat, entity and countermeasures; and a data integration mechanism for integrating distributed security related data into a security data repository that is specific to an organization for information security modelling

    A Study of Molecular Interface of Grass-Herbivory Interaction in Grass

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    Grass-herbivore interaction is a complex process that involves wounding effects caused by herbivore feeding, defoliation effects due to leaf-surface loss during grazing, and the deposition of herbivore saliva onto the surface of plants (Chen et al., 2009). Wounding can stimulate plant growth but clearly differs from grazing (Mattiacci et al., 1995). Defoliation affects root development in grasses and alters the carbohydrate-metabolism pathway in rice. Saliva has been found to stimulate plant growth, enhance tiller and increase biomass. However, little is known about the molecular mechanisms of plant responses to grazing in molecular level. In our previous transcriptome studies, many genes relating with grazing were identified from sheepgrass (Li et al., 2013). In last IGC report, we proposed the concept of “molecular interface on grass-herbivore interaction” (Liu et al., 2013) to understand the interaction between plant and large herbivories on molecular level, which has significant importance on agriculture and grassland conservation. This paper will present some new results in the area

    Germplasm Evaluation of an Eurasia Steppe Native Specie--Sheepgrass (\u3cem\u3eLeymus chinensis\u3c/em\u3e)

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    Sheepgrass (Leymus chinensis (Trin.) Tzvel) is an advantageous perennial native grass in China and other northern Eurasian countries having steppe. As an important forage grass of great value in animal husbandry, sheepgrass is well known for its abundant foliage, high palatability and high nutritive content. Sheepgrass is also valuable in grassland restoration and conservation since it is a perennial grass with a rhizome network to fix the soil and can survive well in stressful environments. Terefore, the collection, evaluation and utilization of sheepgrass are necessary for protecting grassland biodiversity, for establishing artificial pasture, restoring degraded grassland, and the development of forage industry and animal husbandry in Eurasia’s native steppe. Here, we reviewed our previous studies on the collection, evaluation of phenotypic diversity for germplasm resources, distribution and domestication of wild sheepgrass, and application of sheepgrass new varieties

    Bovine serum albumin in saliva mediates grazing response in Leymus chinensis revealed by RNA sequencing

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    BACKGROUND: Sheepgrass (Leymus chinensis) is an important perennial forage grass across the Eurasian Steppe and is adaptable to various environmental conditions, but little is known about its molecular mechanism responding to grazing and BSA deposition. Because it has a large genome, RNA sequencing is expensive and impractical except for the next-generation sequencing (NGS) technology. RESULTS: In this study, NGS technology was employed to characterize de novo the transcriptome of sheepgrass after defoliation and grazing treatments and to identify differentially expressed genes (DEGs) responding to grazing and BSA deposition. We assembled more than 47 M high-quality reads into 120,426 contigs from seven sequenced libraries. Based on the assembled transcriptome, we detected 2,002 DEGs responding to BSA deposition during grazing. Enrichment analysis of Gene ontology (GO), EuKaryotic Orthologous Groups (KOG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways revealed that the effects of grazing and BSA deposition involved more apoptosis and cell oxidative changes compared to defoliation. Analysis of DNA fragments, cell oxidative factors and the lengths of leaf scars after grazing provided physiological and morphological evidence that BSA deposition during grazing alters the oxidative and apoptotic status of cells. CONCLUSIONS: This research greatly enriches sheepgrass transcriptome resources and grazing-stress-related genes, helping us to better understand the molecular mechanism of grazing in sheepgrass. The grazing-stress-related genes and pathways will be a valuable resource for further gene-phenotype studies. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2164-15-1126) contains supplementary material, which is available to authorized users

    An underwater image enhancement model for domain adaptation

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    Underwater imaging has been suffering from color imbalance, low contrast, and low-light environment due to strong spectral attenuation of light in the water. Owing to its complex physical imaging mechanism, enhancing the underwater imaging quality based on the deep learning method has been well-developed recently. However, individual studies use different underwater image datasets, leading to low generalization ability in other water conditions. To solve this domain adaptation problem, this paper proposes an underwater image enhancement scheme that combines individually degraded images and publicly available datasets for domain adaptation. Firstly, an underwater dataset fitting model (UDFM) is proposed to merge the individual localized and publicly available degraded datasets into a combined degraded one. Then an underwater image enhancement model (UIEM) is developed base on the combined degraded and open available clear image pairs dataset. The experiment proves that clear images can be recovered by only collecting the degraded images at some specific sea area. Thus, by use of the scheme in this study, the domain adaptation problem could be solved with the increase of underwater images collected at various sea areas. Also, the generalization ability of the underwater image enhancement model is supposed to become more robust. The code is available at https://github.com/fanren5599/UIEM
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