266 research outputs found
Large-scale Tree Parsimony
Finding the tree of life is one of the major challenges that scientists are attempting to solve. It is widely believed that the evolution of species can (mostly) be depicted in a tree graph, the phylogenetic tree. However, the true phylogenetic species tree is often unknown. One approach is to computationally infer phylogenetic trees from phylogenetic information encoded in genomic data. With the advancement of sequencing techniques, we have a rapidly growing availability of phylogenetic data, which enable the construction of large-scale phylogenetic trees. This thesis addresses algorithmic issues for the construction of large-scale phylogenetic species trees, the supertrees, and the exploration and analysis of large-scale phylogenetic trees. We present (i) new algorithms for local search methods for supertree construction that reduce the time complexity by an order of magnitude and a parallelization for these methods, (ii) new methods for constructing better supertrees from estimated trees and inferring small, exact phylogenetic trees, and (iii) a novel, interactive visual method for the large-scale tree exploration and the concurrent analysis of multiple gene trees and one species tree
Undermining learning: the impact of rewards on learning behavior
2016 Fall.Includes bibliographical references.The undermining effect suggests that external rewards can decrease levels of internal motivation. Research exploring student motivation shows that internally motivated students appear to engage longer and in more challenging tasks compared to students focused on external rewards or performance feedback. The current study tested variables that may decrease susceptibility to motivational undermining for learning behaviors. In all studies, students were assigned to either a reward or non-reward condition and completed a word-learning task followed by a final test. Subjects were given the option to choose to re-study the words at two times during the task—pre- (while reward is still achievable) and post-test (after reward is given and no further extrinsic reward is achievable). Across all studies, an undermining effect was expected: Non-reward subjects would spend a greater amount of time reviewing the words during the post-test interval compared to the reward group. Study 1 directly tested the hypothesis by observing whether or not the reward groups behaved differentially at the pre- and post-test choice. Reward subjects spent significantly less time engaging in the task during the post-test review phase, supporting the presence of the undermining effect (t (1,60)=2.06, p = .02, 1-tailed) but a 2 (group: reward x non-reward) x 2 (study time: pre-test x post-test) repeated measures ANOVA comparing the mean study times for the reward and non-reward subjects’ pre-test study and post-test review time revealed that the interaction between group and study time did not reach significance (F (1,60) = 3.52, p = .065). Study 2 was identical to the first study but with the addition of a surprise, 24-hour delayed memory test to examine whether the extra post-test study had beneficial effects on long-term retrieval. Non-reward subjects were hypothesized to recall more items on a delayed memory test compared to reward subjects due to increased study time. A 2 (group: reward x non-reward) x 2 (study time: pre-test x post-test) repeated measures ANOVA was conducted to compare the mean study times for the reward and non-reward subjects’ pre-test study and post-test review times. The interaction between group and time spent on task was significant (F (1,241) = 4.24, p < .05) but there was not a significant main effect for the between subjects variable of reward on the amount of time spent engaging in the task during the pre- and post-test phases (F (1)= .63, p = .44). A 2 (group: reward vs. non-reward group) x 2 (test performance: immediate x delayed) repeated measures ANOVA was conducted to compare the average accuracy between groups on the delayed memory test. There was not a main effect of group on performance (F (1, 110) = .82, p = .38) and the interaction between reward group and immediate or delayed test was not significant (F (1,156) = .201, p = .65). Study 3 was similar to the first study but subjects were allowed to choose the material they were learning (i.e., Swahili or Lithuanian words). The element of choice was expected to increase the degree of control and internal motivation students experienced and consequently decrease the effect of undermining between the reward and non-reward group. Specifically, study times between the reward and non-reward group were hypothesized to be equal between groups and higher than then a forced choice condition. A 2 (group: reward x non-reward) x 2 (choice: self-determined x forced-choice) x 2 (study time: pre-test x post-test) x 2 (language: Swahili x Lithuanian) repeated measures ANOVA was conducted. The main effect of choice condition was not significant (F (1,60) = .140, p = .71). The main effect of reward was also not significant (F (1,60) = .920, p = .34) but the interaction between choice and reward on time spent on task was significant (F (1,60) =4.11, p < .05). A 2 (group: reward x non-reward) x 2 (choice: self-determined x forced-choice) repeated measures ANOVA was conducted to compare performance on an immediate memory test for the self-determined and forced choice group but the effect was non-significant (F (1,60) = .67, p = .16); in addition, there was not a significant main effect of reward (p =.32) nor was there an interaction (p = .16)
A Review of Two Pelvic Osteotomies Used in the Management of Congenital Hip Dislocation
This paper is a literature search of two common pelvic osteotomies used in the treatment/management of congenital hip dislocation. The Chiari and Salter procedures are reviewed along with their use in restoring normal hip joint, congruency, indication for use, and success rates. The Chiari procedure displaces the acetabulum medially and has the best results in children over four years of age or when the acetabulum is too small for the femoral head. A Salter procedure redirects the entire acetabulum and is optimal for subluxations one and one-half years to adult or dislocations one and one-half to six years
Occupational Therapy Program for Women Residing in Domestic Violence Shelters
Background Domestic violence is a public health concern that affects 43.6 million women, or greater than one in three women, each year in the United States (National Coalition Against Domestic Violence [NCADV], n.d.). Following experiences with domestic violence, victims endure various long-term physical and mental health challenges. These challenges negatively affect women’s abilities to carry out many daily occupations, as well as live independently. When a victim flees domestic violence, they often find themselves seeking support and safety from domestic violence shelters. These shelters are designed to focus on the victim’s immediate physical needs and less on their mental health and long term recovery needs. Therefore, many victims find themselves leaving the shelter with many unmet occupational needs.
Purpose Currently, there is a limited number of occupational therapy practitioners providing services to victims in domestic violence shelters as well as limited resources available to target victims\u27 unmet needs. Therefore, the purpose of this scholarly project is to create a program that may be used to guide occupational therapy practitioners in providing services and addressing unmet occupational needs of women residing in domestic violence shelters.
Methods An extensive literature review was conducted to guide the development of this product. Through examining and analyzing various research articles, primary areas of occupational need emerged. These include: work, social participation, rest and sleep, and instrumental activities of daily living, both health management and maintenance, child rearing, and various underlying client factors. The Kawa model was used to organize this information and guide development of this product.
Results Based on the primary occupational needs identified in the literature, an occupational therapy program for women in domestic violence shelters was developed. This program directly targets victims unmet needs as identified in the literature. The goal of this program is to help victims of domestic violence reach a state of balanced well-being and build a better future for themselves.
Conclusion The purpose of this product is to guide occupational therapy practitioners in providing services to victims of domestic violence residing in domestic violence shelters. The product also serves to advocate for the role of occupational therapy within domestic violence shelters. It is recommended that further research be conducted in order to test and strengthen the effectiveness of this program
Evolution of Occupational Therapy Practice: The Life History of Tammy Olson, COTA
Purpose
The life history of Tammy Olson was one of 31 life history interviews conducted for a larger project, Life Histories of Individuals Who Have Been Influential in Developing Occupational Therapy (OT) in North Dakota and Wyoming. The purpose of this study is to gather information about the history and evolution of OT practice in North Dakota and Wyoming through life histories of individuals who have been influential in developing OT in these two states. This study will provide current and future generations of occupational therapists and occupational therapy assistants a view of the history and how the profession has evolved from its inception to current practice in North Dakota and Wyoming. The life history of Tammy Olson will focus on her experiences as a certified occupational therapy assistant (COTA) in rural practice.https://commons.und.edu/ot-oral-histories-posters/1058/thumbnail.jp
Evolution of Occupational Therapy Practice: Life History of Tammy Olson, COTA
The purpose of this qualitative study was to gather information about the history and evolution of occupational therapy (OT) practice in North Dakota and Wyoming through life histories of individuals who have been influential in developing OT in these two states. This study focused on the life history of Tammy Olson, and her involvement and experiences in the evolution of OT practice. A face-to-face semi-standardized interview which lasted approximately one hour, along with the participant’s curriculum vitae (CV), was used to gather information. The interview was transcribed verbatim and analyzed to develop themes that reflected influential events, opportunities, and challenges throughout Tammy’s personal and professional life. Tammy Olson has been influential in rural practice due to her commitment and passion for enhancing and promoting functional independence in the lives of others. Her experiences throughout her career have empowered her to become an educator and advocate for the certified occupational therapy assistant (COTA) profession
Detection of concealed special nuclear material using nuclear resonance fluorescence technique
Journal ArticleAbstract-Detection method based on Nuclear Resonance Fluorescence (NRF) technique targeting concealed Special Nuclear Material (SNM) has been discussed. Customized DAQ system has been developed to handle high rate events in NRF measurements by implementing real-time DSP on fast ADC and FPGA chip. Experiments have been setup for feasibility study utilizing a 3 MeV Van de Graaff accelerator. NRF peaks from various samples have been observed using both HPGe detector and lanthanum halide scintillation detector
Control elements for an unmanned Martian roving vehicle
The roving vehicle simulator was operated autonomously under control of the simulated on-board computer. With the microwave radar obstacle sensor mounted and operating, it was able to avoid a student placed in its path and to return to the originally assigned direction when that path was clear. The tactile obstacle sensor was able to detect impassable obstacles while allowing the vehicle to negotiate passable obstacles
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