7,720 research outputs found
A systems-biology approach to understanding the ciliopathy disorders.
'Ciliopathies' are an emerging class of genetic multisystemic human disorders that are caused by a multitude of largely unrelated genes that affect ciliary structure/function. They are unified by shared clinical features, such as mental retardation, cystic kidney, retinal defects and polydactyly, and by the common localization of the protein products of these genes at or near the primary cilium of cells. With the realization that many previously disparate conditions are a part of this spectrum of disorders, there has been tremendous interest in the function of cilia in developmental signaling and homeostasis. Ciliopathies are mostly inherited as simple recessive traits, but phenotypic expressivity is under the control of numerous genetic modifiers, putting these conditions at the interface of simple and complex genetics. In this review, we discuss the ever-expanding ciliopathy field, which has three interrelated goals: developing a comprehensive understanding of genes mutated in the ciliopathies and required for ciliogenesis; understanding how the encoded proteins work together in complexes and networks to modulate activity and structure-function relationships; and uncovering signaling pathways and modifier relationships
Exploring Relationships between Students’ Discussion Patterns, Emotions and Learning Outcomes in an Online Mathematics Course
This study aims to 1) identify and characterize groups of students based on their online discussion patterns, emotions, and contents; and 2) investigate associations between these patterns and their learning outcomes in an online developmental mathematics course. Data mining of both clickstream and textual data collected by a Learning Management System (LMS) enabled an analysis in terms of how students meaningfully engaged with discussions, conceived as both online speaking and listening behaviors. Findings revealed six groups of students that exhibited similar online discussion patterns and emotions. Moreover, higher performing students showed higher levels online listening and were more engaged in course content; lower performing students showed superficial engagement in the discussions as they talked about off-topic content
Effects of Discussion Strategies and Learner Interactions on Performance in Online Mathematics Courses: An Application of Learning Analytics
In higher education, a widely used online instructional method to enhance learners\u27 engagement, presence, and achievement is asynchronous online discussions. Yet studies demonstrating their effectiveness, especially in high-failure rate courses like mathematics, remain elusive. The objectives of the study are to investigate 1) what online discussion strategies are associated with positive student performance, 2) to what extent do different structures designed into online discussions impact the kinds of learner interactions, and 3) what types of learner interactions are associated with positive student performance. In particular, by applying a set of text mining and data mining techniques (e.g., Classification and Regression Tree), this study analyzes clickstream and textual data automatically collected by a Learning Management System (LMS) for five consecutive years at a university located in the western U.S. The results of study will inform instructors and instructional designers how to design the better online mathematics courses
Micro-and-Nanostructuring of Polyvinylidene Fluoride with Tailored Crystal Polymorphs and Enhanced Piezoelectric Property
Polyvinylidene fluoride (PVDF) has garnered interest due to its piezoelectric property and as a non-toxic, conformable, and low-cost alternative to the popular piezoelectric ceramic. A novel processing method through the combination of thermal and supercritical carbon dioxide (ScCO2) has been used to successfully promote the formation of electroactive phases (i.e., beta and gamma phases), as well as its piezoelectric property. In this report, the processing-to-structure properties and mechanisms that affect crystallization behaviors of electroactive phases were elucidated. It was revealed that gamma crystal formation was through thermal processing while beta phase was nucleated through fast cooling and physical foaming of CO2 bubbles. The results were comparable to common processing method and literature, with a maximum electroactive crystal phase of 72.2% and a corresponding piezoelectric coefficient of 7.7 pC/N. The findings in this study could provide insight to future research work on PVDF, advancing its development in piezoelectric applications
Doctor of Philosophy
dissertationAs the entry site into the secretory pathway, the endoplasmic reticulum (ER) is responsible for folding and processing secreted proteins. Both physiological and pathological conditions can perturb protein homeostasis in the lumen of the ER, a situation t
Examining the Effects of Discussion Strategies and Learner Interactions on Performance in Online Introductory Mathematics Courses: An Application of Learning Analytics
This dissertation study explored: 1) instructors’ use of discussion strategies that enhance meaningful learner interactions in online discussions and student performance, and 2) learners’ interaction patterns in online discussions that lead to better student performance in online introductory mathematics courses. In particular, the study applied a set of data mining techniques to a large-scale dataset automatically collected by the Canvas Learning Management System (LMS) for five consecutive years at a public university in the U.S., which included 2,869 students enrolled in 72 courses.
First, the study found that the courses that posted more open-ended prompts, evaluated students’ discussion messages posted by students, used focused discussion settings (i.e., allowing a single response and replies to that response), and provided more elaborated feedback had higher students final grades than those which did not. Second, the results showed the instructors’ use of discussion strategies (discussion structures) influenced the quantity (volume of discussion), the breadth (distribution of participation throughout the discussion), and the quality of learner interactions (levels of knowledge construction) in online discussions. Lastly, the results also revealed that the students’ messages related to allocentric elaboration (i.e., taking other peers’ contributions in argumentive or evaluative ways) and application (i.e., application of new knowledge) showed the highest predictive value for their course performance.
The findings from this study suggest that it is important to provide opportunities for learners to freely discuss course content, rather than creating a discussion task related to producing a correct answer, in introductory mathematics courses. Other findings reported in the study can also serve as guidance for instructors or instructional designers on how to design better online mathematics courses
Two teacher educators’ approaches to developing preservice elementary teachers’ mathematics assessment literacy: Intentions, outcomes, and new learning
The purpose of this study was to examine and reflect on two teacher educators’ approaches to developing preservice elementary teachers’ mathematics assessment literacy. We explored the similarities and differences in preservice teachers’ conceptions of good assessment practices and their critique of assessment items. We found that we, as course instructors, had different assumptions pertaining to the role of preservice teachers in the development of assessment and offered different assessment-related course activities. Despite these differences, there were more similarities than differences between the two groups of the preservice teachers with regard to their overall perceptions about good assessment practices and their critique of assessment items. However, we also observed differences in the criteria they used in critiquing assessment items. Discussions and implications are presented in accordance with these findings as a means to improve our own teaching and student learning
Characterizations of matrix valued asymmetric truncated Hankel operators
In this paper we introduce the class of matrix valued asymmetric truncated
Hankel operators. By using characterizations of matrix valued asymmetric
truncated Toeplitz operators, we characterize matrix valued asymmetric
truncated Hankel operators in the case when two involved inner matrices are
J-symmetric.Comment: arXiv admin note: text overlap with arXiv:2103.1571
Exploring Motivational Factors for Dude Ranch Vacations
Dude-ranch vacations have been popular for a segment of travelers. Research in purchase motivation spans various sectors of the hospitality industry; however issues surrounding the dude-ranch industry remain unexplored. The objectives of the study were: (1) to examine the impact of push and pull factors of motivations on customer purchase intention in dude-ranch vacations, (2) to survey the sources of information behind purchase decision for dude ranch vacations. Factor analysis and regression analysis were used for data analysis. The results of the study indicated that pull factors significantly influenced purchase intention of dude ranch vacations more strongly than push factors. ‘Value for money’ and ‘Quality of food and beverage’ were the highest ranked attributes of pull factor; ‘To enjoy myself and make myself happy while relaxing’ was the highest push attribute. The primary source of information was the category of ‘Personal source’ which include ‘Family/Friend’ and ‘Social media’. This study contributes to the body of literature by extending the existing motivation research into a new area and offers insight for dude-ranch owners/operators that can assist in marketing and resource allocation decisions
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