NEARING THE END: REEF BUILDING CORALS AND BIVALVES IN THE LATE TRIASSIC AND COMPARING CORALS AND BIVALVES BEFORE AND AFTER THE END-TRIASSIC MASS EXTINCTION USING A TAXONOMIC DATABASE

One of the most important tenants in geology is that the present is the key to the past, but it can also be said that the past is the key to the present. The five great extinction events are some of the key events that can help us to understand how changes in climate and sea chemistry can cause great changes in the ecology of our planet. Today the increase in atmospheric CO2 is causing ocean acidification, which has also been proposed as part of the system that caused the end-Triassic mass extinction. Ocean acidification can be greatly detrimental to the skeletal structures of marine invertebrate such as reef building corals and bivalves. During the Norian and Rhaetian (Late Triassic), corals and bivalves had high diversity and abundance, but like many organisms involved in the mass extinction, quickly disappeared at the end of the Triassic. In the early Jurassic, very few surviving species of corals can be found, and almost no reefs. If this ‘reef gap’ was caused by a change in ocean chemistry, then how did these few species of corals survive? Were bivalves also affected by the changes? On Vancouver Island, rock units containing corals and bivalves can be found that represent both Norian and Rhaetian time intervals, but early Jurassic sedimentary units are found rarely, if ever. This creates a difficulty in looking for patterns in changes that happened after the mass extinction, but does allow for analysis of what reef communities looked like shortly before the end of the Triassic. In addition, by building upon data from the Paleobiology Database, changes in the global reef communities after the end-Triassic mass extinction can be examined

Comparison of Venous Return Characteristics with Right Ventricular Mechanics During Cephalic Fluid Shift

For my summer internship project, I organized a pilot study to analyze the effects of a cephalic fluid shift on venous return and right ventricular mechanics to increase right ventricular and venous knowledge. To accomplish this pilot study, I wrote a testing protocol, obtained Institutional Review Board (IRB) approval, completed subject payment forms, lead testing sessions, and analyzed the data. This experiment used -20deg head down tilt (20 HDT) as the ground based simulation for the fluid shift that occurs during spaceflight and compared it to data obtained from the seated and supine positions. Using echocardiography, data was collected for the right ventricle, hepatic vein, internal jugular vein, external jugular vein, and inferior vena cava. Additionally, non-invasive venous pressure measurements, similar to those soon to be done in-orbit, were collected. It was determined that the venous return from below the heard is increased during 20 HDT, which was supported by increased hepatic vein velocities, increased right ventricular inflow, and increased right ventricular strain at 20 HDT relative to seated values. Jugular veins in the neck undergo an increase in pressure and area, but no significant increase in flow, relative to seated values when a subject is tilted 20 HDT. Contrary to the initial expectations based on this jugular flow, there was no significant increase in central venous pressure, as evidenced by no change in Doppler indices for right arterial pressure or inferior vena cava diameter. It is suspected that these differences in pressure are due to the hydrostatic pressure indifference point shifting during tilt; there is a potential for a similar phenomenon with microgravity. This data will hopefully lead to a more in-depth understanding of the response of the body to microgravity and how those relate to the previously mentioned cardiovascular risk of fluid shift that is associated with spaceflight. These results were presented in greater detail to the Cardiovascular Laboratory and the Space Life Science Summer Institute, which helped me prepare for future graduate school research presentations. This internship allowed me to apply and expand the anatomy, physiology, and mechanics information I learned during my undergraduate degree in Biomedical Engineering to the cardiovascular system with the unique zero gravity perspective. Additionally, I was able to develop skills with data analysis techniques involving speckle tracking for ventricular strain and Doppler waveforms for blood velocities. Additionally, I was able to expand upon my previous work in the Cardiovascular Laboratory by writing a literature review on a data analysis project I completed last summer. Ultimately, this internship and venous relationship comparison project provided me with a significant learning experience and additional skill sets, which are applicable to my goals of attaining a Ph.D. in biomedical engineering with a focus on tissue engineering and the cardiovascular system

Compliance-based Affordance Templates for remote mobile manipulation

This thesis details the implementation of Affordance Templates with a compliance controller to pseudo-autonomously perform complex contact tasks in industrial environments. Multiple action planning methods were evaluated, and ATs were chosen as the best option for industry use due to their intuitive user interface. Two Affordance Template packages were implemented and evaluated to determine the package best suited for use by novice operators. That package was then implemented in conjunction with a compliance controller in the form of a remote demonstration to showcase reduction in operator cognitive burden by automatically managing contact forces and significant command latency (approx 250 ms) during task performance. The results showed that ATs greatly reduced task execution time and number of errors compared to manual control, with added compliance reducing AT set up time. Finally, this thesis introduces Affordance Primitives, which were created to increase the flexibility of Affordance Templates and present a path for future development in the field of automated task planning.Mechanical Engineerin

Peer Victimisation in University Sport in the UK

This thesis investigates the nature and prevalence of peer victimisation in UK university sports. The Transactional model of stress (TMS) is used to examine the relationships between peer victimising behaviours, group cohesion and sport amotivation in the presence of a primary and secondary appraisal. A sample of 207 first-year student athletes from 16 universities in the UK completed an online questionnaire regarding peer victimising behaviours. The questionnaire includes measures of challenge appraisals, perceptions of social support, group cohesion (task and social) and sport amotivation. Two moderated mediation models were conducted to examine if challenge appraisal mediated, and perceived social support moderated, the relationship between peer victimisation and the outcomes variables. The results indicated significant negative relationships peer victimisation and group cohesion. Perceived social support moderated the relationship between peer victimisation and group cohesion. The moderation effect reversed the negative relationship resulting in an increase in group cohesion. Perceived social support moderated the relationship between peer victimisation and sport amotivation. The moderation effect reversed the positive relationship resulting in a decrease in sport amotivation. Challenge appraisals did not significantly mediate the relationship between victimisation and either sport amotivation or group cohesion. This study provides further evidence of the high rate of peer victimising behaviours in university sport in the UK. This study provides support for further research into the use of perceived social support in counteracting the negative impacts of these behaviours

Probabilistic Segmentation of Small Metastatic Brain Tumors using Liquid State Machine Ensemble

View full abstracthttps://openworks.mdanderson.org/leading-edge/1017/thumbnail.jp

THE INTRACELLULAR DISTRIBUTION OF GAMMA GLOBULIN IN A MOUSE PLASMA CELL TUMOR (X5563) AS REVEALED BY FLUORESCENCE AND ELECTRON MICROSCOPY

Ferritin- and fluorescein-conjugated antibody staining has been applied to a study of a mouse plasma cell tumor. The presence of myeloma globulin within cisternae of the endoplasmic reticulum was observed at a stage of the secretory process when the remainder of the cytoplasm was essentially free of labeled globulin. The distribution of ferritin suggested a functional heterogeneity among units of the endoplasmic reticulum. Apparently, progressive accumulation of globulin results in distension of the endoplasmic reticulum and, occasionally, in the appearance of considerable quantities of this secretory protein in the extracisternal cytoplasmic matrix. Participation of the Golgi apparatus in the packaging and release of small quantitites of globulin seems likely. In addition, however, fragmentation of the peripheral cytoplasm with rupture of distended ergastoplasmic vesicles appeared to be another pathway whereby globulin is secreted

Deficits in episodic future thinking following acute alcohol consumption

Rationale Acute alcohol consumption adversely affects many cognitive abilities, including episodic memory and executive functioning. However, no study to date has tested whether these acute effects of alcohol also extend to episodic future thinking (EFT). This is a surprising omission given that EFT refers to the ability to imagine oneself experiencing the future, a highly adaptive ability that has been implicated in many important functional behaviours. EFT is also thought to impose demands on episodic memory and executive control. Objectives The current study was designed to provide the first test of whether a moderate dose of alcohol influences EFT and whether any observed EFT difficulties are secondary to broader problems in episodic memory and executive functioning. Sex differences in EFT following acute alcohol consumption were also examined. Methods One hundred and twenty-four healthy adult social drinkers were recruited and randomly assigned to either the alcohol (n = 61) or placebo (n = 63) condition. Participants were administered a dose of 0.6 g/kg alcohol or a matched placebo drink. Results Relative to the placebo condition, EFT was impaired by acute alcohol consumption. This impairment was underpinned by broader difficulties with episodic memory, but not executive functioning. There were no sex differences in EFT performance following acute alcohol use. Conclusion These data provide novel insights into the effects of acute alcohol consumption on EFT and the broader cognitive mechanisms that contribute to these difficulties. The results are discussed in relation to their implications for understanding many of the maladaptive behaviours commonly associated with acute alcohol use

The electronic structure and band gap of LiFePO4 and LiMnPO4

Materials with the olivine LixMPO4 structure form an important new class of materials for rechargeable Li batteries. There is significant interest in their electronic properties because of the importance of electronic conductivity in batteries for high rate applications. The density of states of LixMPO4 (x = 0, 1 and M = Fe, Mn) has been determined with the ab initio GGA+U method, appropriate for these correlated electron systems. Computed results are compared with the optical gap of LiFePO4, as measured using UV-Vis-NIR diffuse reflectance spectroscopy. The results obtained from experiment (3.8-4.0 eV) and GGA+U computations (3.7 eV) are in very good agreement. However, standard GGA, without the same level of treatment of electron correlation, is shown to make large errors in predicting the electronic structure. It is argued that olivines are likely to be polaronic conductors with extrinsically determined carrier levels and that their electronic conductivity is therefore not simply related to the band gap.Comment: 17 pages, 2 figure