Effects of Neuromuscular Fatigue Resulting from Repeat Sprint Exercise Among Trained Cyclists on Measures of Strength and Power Performance

The purpose of this dissertation is to better understand the role of repeated-sprint ability (RSA) and resulting fatigue in cyclists; how it relates to measures of aerobic power and strength and power performance indices- due to the nature of cycling competitions and the necessity of RSA for success. The first part of this dissertation attempted to elucidate the relationship between RSA and aerobic power and strength/ power measures in competitive cyclists. The purpose was to potentially illustrate the importance of the inclusion of strength and power training in the training regimen of cyclists. The findings showed several statistically significant relationships between variables of RSA and aerobic power or the isometric squat test. The second part of the dissertation examined the effects of fatigue induced from the acute bout of repeat sprint exercise on strength and power measures in three different recovery periods. It is commonplace for cyclists to have several heats in one day of racing. Examining the effects of fatigue on strength measures such as peak force and rate of force development could begin to delineate how an individual experiences fatigue based on their own characteristics, enabling them to design a training program to address these strengths/ weaknesses to optimize performance and decrease fatigue. The results from a repeated measures analysis of variance found no statistically significant effect on PF or RFD. Additional comparisons showed moderate effects of fatigue on RFD throughout the three post-RSE trials. There was also a moderate correlation between the RSE fatigue % decrement score and the isometric RFD fatigue % decrement score. What we may conclude from this dissertation is that fatigue has various causes and can vary with an individuals’ unique physiology and how they respond to performance variables on any specific day can vary. Development of increased strength and subsequent power, or “explosive strength”, may have advantages in competitive cycling. Coupling proper strength and power training with an aerobic training regimen, may greatly benefit the athlete by increasing their peak power output, economy of movement, delaying fatigue, improving anaerobic capacity, and overall enhancing their maximal speed

Validation of High-Speed Turbulent Boundary Layer and Shock-Boundary Layer Interaction Computations with the OVERFLOW Code

The capability of the OVERFLOW code to accurately compute high-speed turbulent boundary layers and turbulent shock-boundary layer interactions is being evaluated. Configurations being investigated include a Mach 2.87 flat plate to compare experimental velocity profiles and boundary layer growth, a Mach 6 flat plate to compare experimental surface heat transfer,a direct numerical simulation (DNS) at Mach 2.25 for turbulent quantities, and several Mach 3 compression ramps to compare computations of shock-boundary layer interactions to experimental laser doppler velocimetry (LDV) data and hot-wire data. The present paper describes outlines the study and presents preliminary results for two of the flat plate cases and two small-angle compression corner test cases

Do the more flexible individuals rely more on causal cognition? Observation versus intervention in causal inference in great-tailed grackles

Behavioral flexibility, the ability to change behavior when circumstances change based on learning from previous experience, is thought to play an important role in a species’ ability to successfully adapt to new environments and expand its geographic range. However, it is possible that causal cognition, the ability to understand relationships beyond their statistical covariations, could play a significant role in rapid range expansions by allowing one to learn faster by making better predictions about outcomes and by exerting more control over events. We aim to determine whether great-tailed grackles (Quiscalus mexicanus), a species that is rapidly expanding its geographic range, use causal inference and whether this ability relates to their behavioral flexibility (flexibility measured in these individuals by Logan et al. 2019: reversal learning of a color discrimination and solution switching on a puzzle box). We found that grackles showed no evidence of making causal inferences when given the opportunity to intervene on observed events using a touchscreen apparatus, and that performance on the causal cognition task did not correlate with behavioral flexibility measures. This could indicate that causal cognition is not implicated as a key factor involved in a rapid geographic range expansion, though we suggest further exploration of this hypothesis using larger sample sizes and multiple test paradigms before considering this a robust conclusion

Dynamic microRNA activity identifies therapeutic targets in trastuzumab‐resistant HER2+ breast cancer

MicroRNAs (miRNAs) are implicated in numerous physiologic and pathologic processes, such as the development of resistance to chemotherapy. Determining the role of miRNAs in these processes is often accomplished through measuring miRNA abundance by polymerase chain reaction, sequencing, or microarrays. We have developed a system for the large‐scale monitoring of dynamic miRNA activity and have applied this system to identify the contribution miRNA activity to the development of trastuzumab resistance in a cell model of HER2+ breast cancer. MiRNA activity measurements identified significantly different activity levels between BT474 cells (HER2+ breast cancer) and BT474R cells (HER2+ breast cancer cells selected for resistance to trastuzumab). We created a library of 32 miRNA reporter constructs, which were delivered by lentiviral transduction into cells, and miRNA activity was quantified by bioluminescence imaging. Upon treatment with the bioimmune therapy, trastuzumab, the activity of 11 miRNAs were significantly altered in parental BT474 cells, and 20 miRNAs had significantly altered activity in the therapy‐resistant BT474R cell line. A combination of statistical, network and classification analysis was applied to the dynamic data, which identified miR‐21 as a controlling factor in trastuzumab response. Our data suggested downregulation of miR‐21 activity was associated with resistance, which was confirmed in an additional HER2+ breast cancer cell line, SKBR3. Collectively, the dynamic miRNA activity measurements and analysis provided a system to identify new potential therapeutic targets in treatment‐resistant cancers.MicroRNAs (miRNAs) are often dysrgulated in cancer and can give rise to drug resistance. Identifying the mechanisms for resistance may lead to new This work used an array of miRNA activity reporters to identify miR‐21 as a mediator of trastuzumab resistance in breast cancer.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146392/1/bit26791.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146392/2/bit26791_am.pd

Assessment of Turbulent Shock-Boundary Layer Interaction Computations Using the OVERFLOW Code

The performance of two popular turbulence models, the Spalart-Allmaras model and Menter s SST model, and one relatively new model, Olsen & Coakley s Lag model, are evaluated using the OVERFLOWcode. Turbulent shock-boundary layer interaction predictions are evaluated with three different experimental datasets: a series of 2D compression ramps at Mach 2.87, a series of 2D compression ramps at Mach 2.94, and an axisymmetric coneflare at Mach 11. The experimental datasets include flows with no separation, moderate separation, and significant separation, and use several different experimental measurement techniques (including laser doppler velocimetry (LDV), pitot-probe measurement, inclined hot-wire probe measurement, preston tube skin friction measurement, and surface pressure measurement). Additionally, the OVERFLOW solutions are compared to the solutions of a second CFD code, DPLR. The predictions for weak shock-boundary layer interactions are in reasonable agreement with the experimental data. For strong shock-boundary layer interactions, all of the turbulence models overpredict the separation size and fail to predict the correct skin friction recovery distribution. In most cases, surface pressure predictions show too much upstream influence, however including the tunnel side-wall boundary layers in the computation improves the separation predictions

Are the more flexible great-tailed grackles also better at behavioral inhibition? (In principle acceptance by PCI Ecology of the version on 6 Mar 2019)

Behavioral flexibility should theoretically be positively related to behavioral inhibition (hereafter referred to as inhibition) because one should need to inhibit a previously learned behavior to change their behavior when the task changes (the flexibility component;). However, several investigations show no or mixed support of this hypothesis, which challenges the assumption that inhibition is involved in making flexible decisions. We aimed to test the hypothesis that behavioral flexibility (measured as reversal learning and solution switching on a multi-access box by Logan et al. 2019) is associated with inhibition by measuring both variables in the same individuals and three inhibition tests (a go/no go task on a touchscreen, a detour task, and a delay of gratification experiment). We set out to measure grackle inhibition to determine whether those individuals that are more flexible are also better at inhibition. Because touchscreen experiments had never been conducted in this species, we additionally validated that a touchscreen setup is functional for wild-caught grackles who learned to use the touchscreen and completed the go/no go inhibition task on it. Results showed that only performance on the go/no go inhibition task correlated with the two flexibility measures: positively with the number of trials to reverse a preference in the reversal learning experiment, and negatively with the average latency to attempt a new option on the multi-access box. That is, individuals who were faster to update their behavior in the reversal experiment were also faster to reach criterion in the go/no go task, but took more time to attempt a new option in the multi-access box experiment. Performance on the detour inhibition task did not correlate with either measure of flexibility, suggesting that detour performance and the flexibility experiments may measure separate traits. We were not able to run the delay of gratification experiment because the grackles never habituated to the apparatuses. Performance on the go/no go and detour inhibition tests did not correlate with each other, indicating that they did not measure the same trait. We conclude that behavioral flexibility is associated with certain types of inhibition, but not others, in great-tailed grackles

SeaWiFS technical report series. Volume 32: Level-3 SeaWiFS data products. Spatial and temporal binning algorithms

The level-3 data products from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) are statistical data sets derived from level-2 data. Each data set will be based on a fixed global grid of equal-area bins that are approximately 9 x 9 sq km. Statistics available for each bin include the sum and sum of squares of the natural logarithm of derived level-2 geophysical variables where sums are accumulated over a binning period. Operationally, products with binning periods of 1 day, 8 days, 1 month, and 1 year will be produced and archived. From these accumulated values and for each bin, estimates of the mean, standard deviation, median, and mode may be derived for each geophysical variable. This report contains two major parts: the first (Section 2) is intended as a users' guide for level-3 SeaWiFS data products. It contains an overview of level-0 to level-3 data processing, a discussion of important statistical considerations when using level-3 data, and details of how to use the level-3 data. The second part (Section 3) presents a comparative statistical study of several binning algorithms based on CZCS and moored fluorometer data. The operational binning algorithms were selected based on the results of this study