Immersion versus Engagement Strategies: Examining the Effects on Conversational Competence amongst Korean Students in an Intensive English Program

This study seeks to examine the effect that immersion versus engagement strategies has on the language growth and efficacy of Korean EFL students learning to speak conversational English in an Intensive English Program (IEP) at an American university. This study utilized quantitative research techniques to answer the various questions that arise in regard to the effectiveness of immersion in an intensive English program. Eight Korean students were selected to partake in the research with four currently attending the IEP program and four having since graduated from the same IEP program. The study was conducted through interviews and questionnaires to examine the effectiveness of immersion strategies within the IEP program. The study found that although some engagement strategies remained somewhat effective for Koreans learning conversational English, the students preferred immersion. The Korean students noted that their interaction with native English speakers in environments where they were immersed in English such as in living situations or extracurricular programs increased their retention of English over activities done in the classroom

Servo Mounting Device and Collective Control System Design for the Forward Flight Aero Test Stand

The majority of the ten-week internship was spent designing a servo mounting device, and a collective control system for the Forward Flight Aero Test (FFAT) stand. The servo mounting device uses four threaded standoffs along with a top plate, held together with screws, that raises the servos above the protruding threaded rods and screws. The collective control system is a rectangular block that attaches the swashplate to the servo arms connected to the servo motor. This control rod is used to translate the rotation from the servo arm into collective control for the blade angle. The control rod has two holes for shoulder bolts that connect it to the non-rotating swashplate and the servo arm. The control rod, servo mount standoffs, and top plate are all currently made from steel 17-4 PH. The screws that attach the top plate to the standoffs are made of black oxide alloy steel, while the shoulder bolts are composed of 18-8 stainless steel. The largest allowable force on the designed system is 50 N, since that is the force at which the standoffs fail under FEA

Management effects on the environmental footprint of swine production

Livestock production in general is a very small contributor to GHG emissions. However, swine producers will continually be faced with a series of challenges to minimize the environmental impact of swine production. The main objectives of the the studies in this thesis were to evaluate the effects of reducing dietary CP with the supplementation of synthetic AA and the effects of feeding diets with or without antibiotics on manure generation and excretion of N and C. In Exp. 1, thirty-two barrows were used in a metabolism study to evaluate the effect of feeding reduced CP, amino acid (AA) supplemented diets on nutrient excretion. Pigs were assigned to one of four dietary treatments: 1) Control: Corn-SBM-DDGS diets with no synthetic AA, 2) 1X reduction in CP, 3) 2X reduction in CP, and 4) 3X reduction in CP. Diet 4 was balanced on the 7th limiting AA, phenylalanine. Diets 2 and 3 were then formulated to have a stepwise reduction in CP between Diets 1 and 4. Diets 2-4 were supplemented with synthetic amino acids as needed to meet amino acid needs based on NRC 2012 AA minimum ratios for the 7 age phases tested. Low-CP AA supplemented diets significantly reduce N excretion by up to 45%. In addition, VFA concentrations were reduced between 9-17% when dietary CP content was reduced up to 3X levels. Overall fecal C excreted (g/pig/d) was greatest for the lowest CP (3X), largely due to the % C digested being the lowest for that diet. Both DE and ME, were linearly (P \u3c 0.0001) decreased by approximately 6 and 5% respectively with increasing reductions in dietary CP. In Exp. 2, seven hundred twenty-three pigs were placed into eleven identical, environmentally controlled rooms for a wean-to-finish study. Pigs were allotted to one of two dietary treatments: 1) Control: Corn-SBM-DDGS diets with Antibiotics, and 2) Antibiotic Free; treatment 1 less the antibiotics but with alternative supplements. Diets were fed in nine dietary phases. There was a tendency for greater final BW and BW gain per manure pit when pigs were fed the control antibiotic treatment. No significant differences were observed between the two dietary treatments for manure volume (L), manure volume per kg BW gain, DM (g/kg BW gain), N (g/kg BW gain), and AmmN (g/kg BW gain). Manure pH tended to be lower for pigs fed the antibiotic free diet (P \u3c 0.06) compared to the control diet. There were no differences observed for manure total C (kg), manure C per kg BW gain, manure C g/pig/d, and manure C g/pig wean-to-finish. In summary, Exp. 1 low CP diets with synthetic AA supplementation result in lower DE and ME values and C digestibility for the lowest CP diets, but significantly reduce N and VFA excretions. In Exp. 2, the antibiotic free diets had similar manure nutrient excretion and generation with lower manure pH which may affect transformation of N2O during manure land application. The adoption of technologies like these evaluated in this thesis will be of the utmost importance in remaining proactive in finding a way to meet the demands of a growing world population in a manner that is cost effective for the producer, while being environmentally sustainable

Contribution of Far Field Effects of Cortical tDCS in the Cerebellum to Learning in an Object Detection Paradigm

Transcranial direct current stimulation (tDCS) has been shown to enhance many cognitive and motor functions, and has been used in many areas, including rehabilitation of speech after stroke, cognitive enhancement, and treatment of mental illness. Our lab has demonstrated that, paired with training, anodal tDCS over electrode site F10 as well as cathodal tDCS over site T5 both increased the ability to detect hidden objects in a complex visual environment in a discovery learning paradigm. Stimulation of F10 has further been shown to enhance perceptual sensitivity selectively, without a change to response bias, and this effect was further enhanced when images presented during training were repeated in a post-training, post-stimulation test (Clark et al., 2012; Coffman et al., 2012; Falcone et al., 2012). Furthermore, this increased ability to detect hidden objects persisted for at least 24 hours Falcone et al., 2012). It has also been shown to increase measures of attention, using the Attention Network Task (ANT; Fan, 2002). Specifically, alerting network scores were increased in participants receiving active anode F10 stimulation compared to sham. Since both F10 anode as well as T5 cathode stimulation both resulted in increased learning the object detection task, potential additive effects were inferred, and an F10 anode/T5 cathode electrode montage was investigated. Surprisingly, this montage had an effect of about half of the other two montages (F10 anode/shoulder, T5 cathode/shoulder). Finite element current modeling studies were conducted to investigate more precisely where in the brain the electricity is traveling during these different stimulation protocols. Results suggested that both cephalic/extra-cephalic electrode placements exhibited far-field effects in subcortical areas, bilateral temporal poles, as well as in the cerebellum, albeit with opposite polarities. During F10 anode/shoulder cathode stimulation, a negative electrical field effect was seen in the cerebellum. During T5 cathode/shoulder anode stimulation, the opposite was true: there was a positive field effect in the cerebellum. However, the montage with a bi-cephalic placement showed no such effect in the cerebellum. Based on these modeling data, the difficulty of reaching subcortical areas with tDCS, and the evidence that the cerebellum is not only involved in motor behavior, but cognition as well, the cerebellum was chosen for direct stimulation with tDCS and was hypothesized to be contributing to the learning and attention effects reported in previous studies. Thirty-six participants received either anodal, cathodal, or sham stimulation of the medial posterior cerebellum during training to detect hidden objects in a complex visual environment. Measures of learning, signal detection, and interactions with stimulus type were investigated. Regression models were also built to investigate the contribution of each electrode placement in the two different montages. Measures of attention assessed with the ANT were also investigated. To our surprise, neither anodal nor cathodal stimulation of the cerebellum led to an increase in learning compared to sham stimulation. Furthermore, no effects were observed between groups on signal detection measures, nor was there an effect of group on stimulus type, all of which had previously been reported with F10 stimulation. Likewise, neither anode nor cathode stimulation led to an improvement on measures of attention compared to sham. The conclusion is that the cerebellum does not appear to be involved in the network contributing to learning and performing the object detection task. Although there were no direct effects of anodal or cathodal tDCS of the cerebellum on learning or attention, this study is an important step in elucidating the network involved in the robust finding of increased ability to detect hidden objects after administration of tDCS paired with training, as it rules out one potential contributor

An Interacting Segment Model for the Calculation of Nonlinear Optical Properties: Theory and Application to Peptide Sequences

The aim of this thesis is to develop and refine an interacting segment model (ISM) for the accurate computational calculation of molecular electrical response properties. Traditional ab-initio quantum mechanical methods require a tremendous amount of computational resources to calculate these properties for larger molecular systems, rendering them infeasible for larger molecules. This ISM looks to address this issue, serving as a method that allows for accurate and timely calculation of properties of interest. It is found that the fits for both dipole moment and isotropic polarizability yield fantastic results when optimized against a set of ‘test molecules’, yielding errors of often less than 1 percent. Conversely, transferability of segments from one system to another produces errors that range from 1 percent to over one-hundred thousand percent. It is possible that this enormous variance in error may be because each segment is represented by a point-dipole in space, whereas higher-order poles may be a more realistic representation. The significance of this study is that it informs our theoretical understanding of interacting segment models and their ability to accurately replicate traditional quantum mechanical methods on a broader and more universal molecular scale