Senior Thesis ST 2011-01

Since the arrival of non-Native peoples to Alaska, the state has heavily relied on importing most food. Food security concerns have been raised related to supply disruptions, cost, and health. This thesis was designed as a pilot study and intended to provide information on local vegetable and fruit production in the Tanana Valley. The results from the study could inform subsequent studies that determine state vegetable and fruit production. Commercial vegetable and fruit producers in the Tanana Valley were surveyed. The response rate was 38.5%. The survey provided insight into characteristics of producers, production, and marketing practices. Increasing crop production in the Tanana Valley is possible, but measuring current production may require a more complex measuring system that is more consistent with producer practices. Alaska faces many challenges if it is to transition from an un-integrated food system to a more comprehensive food system that generates value to local communities

Fountains: Ceramic forms that contain or move fluids

None provided

Session E-7: Is there an App for That?

This presentation will show a variety of different apps for tablets, smart phones, etc. that have educational uses. A number will be presented and demonstrated. Teachers who attend will also be asked to share apps that they use have found valuable, or simply ones that they like

Best Practices To Help English Language Learners Succeed In Community College

After researching various types of support to help English Language Learners (ELLs) succeed in community colleges, the support methods were categorized into four groups: family, peers, faculty and institutions. To share these practices with ELL students and professionals, a website was developed. The intent of the website is to create a community to encourage students to seek out resources and for professionals to implement more support methods, with the ultimate goal of increasing the retention rate of ELL community college students. The website includes a tab with a form asking for feedback on whether the website was helpful and inviting visitors to share the most effective type of support and their experience. Responses will be reviewed and possibly added to the website categories so that the website is constantly evolving and building community

The Effect Of Height And Post-Landing Movement Task On Landing Performance

The purpose of this research was to evaluate selected biomechanical aspects of drop jumps and stable landings performed from increasing heights. The related literature indicates that landings performed in an experimental setting have been to a large degree isolated landing tasks, with subjects landing and remaining in a stable position. It was the intent of this research to address the interactive demands of the complete jumping/landing task. Seven subjects performed three stable landings (L) and three drop jumps (DJ) from each of four initial drop heights (15, 30, 45 and 60cm). All landings were performed with both feet contacting a force platform (500 Hz). Right knee sagittal plane angular displacement was recorded at 500 Hz via an electrogoniometer. Vertical GRF variables used to evaluate landing included maximum impact force (Fmax) normalized to subject body mass, and the time at which the amount of vertical impulse (Timp-land) necessary to account for the downward momentum of the body was achieved. To derive Timp-land, the total body vertical momentum at contact was estimated using contact velocity (calculated from initial drop height) and subject mass. Integration of the GRF curve was perforrned to establish the time relative to contact at which impulse sufficient to reduce landing momentum to zero was achieved. Timpland was therefore indicative of the time period over which the landing phase could be considered complete. In addition, maximum flexion angle at the knee (Kmax) was used in the analysis. Group mean values summarized across heights were as follows for the Land D movement tasks, respectively: Fmax: 52.0 and 41.8N /kg; Timp-land 0.118 and 0.126 sec; Kmax: 71.3 and 80.1 deg. Pearson product correrations were performed for each subject, relating initial drop height (Ht) to each of the three independent variables describing landing. Six of seven subjects (86%) exhibited strong positive correlations (r > .7071; explained variance> 50%) between Ht and Kmax and Ht and Timp-land . indicating an impact force increase and concomitant increase in time over which greater landing momentums were accounted for, observable for landing with and without the peformance of a subsequent jump. The Ht, Kmax relationship was strong and positive for the L conditions (71 % with r > .7071), but only one of seven subjects exhibited a significant Ht, Kmax relationship for the DJ performances. These results suggest that increased knee flexion is a common component of a strategy to absorb landing momentum over longer periods as height increases for stable landings. This does not, however, appear to allow for complete accommodation of Fmax across the full range of heights. The absence of a strong relationship between Ht and Kmax with DJ performance is suggestive of a change in kinematic strategy with the addition of the post-landing movement task

LANDING STRATEGY VARIATIONS: EFFECTS OF SKILL LEVEL, TASK DEMANDS AND MOVEMENT TYPE

INTRODUCTION: The loading of various body structures during landing has been implicated as a source of injury in many sport activities, with injury prevention the focus of most contemporary sport related landing research. Subjects have typically been tested under isolated experimental conditions while performing the movement task of landing and remaining in a stable position (1). Though this movement modality may provide for a large degree of experimental control, such studies of discrete, endpoint landings may not account for all biomechanical aspects of landings performed in conjunction with other movements; a situation which is present in cases where high rates of injury have been reported (2). The purpose of the present study was therefore to evaluate selected aspects of lower extremity function during discrete, endpoint landings and during landings preparatory to a subsequent movement activity, represented by a drop jump. METHODS: Eight female subjects (four skilled athletes, four recreationally active individuals) performed five discrete landings followed by five drop jumps from four initial drop heights (16, 32, 48 and 64cm). Ground reaction force (GRF) and sagittal plane kinematic data were collected for each trial, producing 11 GRF, 18 kinematic and 5 lower extremity stiffness variables for each trial. Of these 34 total variables, 20 represented impact phase parameters, and 14 represented post impact phase parameters. A three-way repeated measures ANOVA was conducted for each variable using the mean of the five trials performed by each subject at respective height and movement conditions. RESULTS AND CONCLUSIONS: A large number of significant main effects in absence of interaction effects illustrates the richness of the three-way ANOVA design with respect to the data set being evaluated. These results highlighted functional differences between discrete and preparatory landings. Both skilled and recreational subjects allowed greater impact forces in the case of the discrete landing. Impact force modulation was attributed largely to differing roles of knee joint function relative to each category of landing. Significant group differences indicated that skilled subjects maintained knee joint angular kinematics optimal for jump performance across the range of heights, where the recreational subjects employed knee joint kinematics indicating a dominant influence of landing demands as opposed to optimizing the landing for vertical jump performance. REFERENCES: 1. Dufek, J.S. and Bates, B.T. Biomechanical factors associated with injury during landing in jump sports. Sports Medicine , 12 (5), 326-337, 1991. 2. Hopper, D.M, Hopper, J.L., and Elliott, B.C. Do selected kinanthropometric and performance variables predict injuries in female netball players? Journal of Sports Sciences, 13, 213-222, 1995

Investigating the Evolution of the Molecular Clock Mechanism Using the Housefly, Musca domestica

Mapping the evolution of the transcriptional feedback loops that regulate the circadian clock will lead to the understanding of how this essential pacemaker allows insects to anticipate changes in their environment. Transcriptional feedback loops were first discovered in Drosophila, and while there is extensive conservation to mammals, it is evident that different insects have diverged or adopted different mechanisms to construct their circadian clocks. Here, we investigate the divergence of the clock in dipterans by characterizing the evolution of molecular clock mechanisms from the model organism Drosophila to another dipteran, the housefly (Musca domestica). In Drosophila the core feedback loop is composed of the core components: Clock (Clk), cycle (cyc), period (per), timeless (tim), clockwork orange (cwo), and cryptochrome (Cry1). CLK binds CYC to initiate the feedback loop, and together they drive transcription of per and tim. PER:TIM heterodimers then repress their own transcription by binding to and inhibiting CLK:CYC. In addition, CWO is a transcriptional repressor which synergizes with PER to repress CLK:CYC activation. Insects such as monarch butterflies, however, appear to have an ancestral clock, possessing not only the Drosophila clock genes but also mammalian components such as the cycle ortholog (Bmal1) and a mammalian cryptochrome, cry2. In mice and “ancestral-like” insect clocks, BMAL1 contains the main transactivation domain of the CLK:BMAL1 complex. In these insects CRY2 also takes the place of Drosophila PER as the main transcriptional repressor. Examination of the genomic sequences of M. domestica identified both the core Drosophila clock genes and the ancestral clock gene, cry2. However, further analysis, showed that mdCry2 is in fact a (6-4) DNA photolyase. Furthermore, characterization of the circadian clock in the housefly and its comparison to the Drosophila clock revealed the functional genetic differences in their transcriptional feedback loops. Indeed, in the housefly CWO appears to have taken on the role of Drosophila PER as the main transcriptional repressor. This work confirms that the organization of the clock has diverged during insect evolution, and that there are multiple genetic approaches to regulating overt rhythmicity