Group extensions problem and its resolution in cohomology for the case of an elementary abelian normal sub-group, The

2018 Summer.Includes bibliographical references.The Jordan-Hölder theorem gives a way to deconstruct a group into smaller groups, The converse problem is the construction of group extensions, that is to construct a group G from two groups Q and K where K ≤ G and G/K ≅ Q. Extension theory allows us to construct groups from smaller order groups. The extension problem then is to construct all extensions G, up to suitable equivalence, for given groups K and Q. This talk will explore the extension problem by first constructing extensions as cartesian products and examining the connections to group cohomology

Treating Glaucoma with Porous Contact Lens

Glaucoma is a family of diseases that afflicts 65 million people worldwide. Primary open angle glaucoma is the most common type of glaucoma. This is characterized by increased intraocular pressure (IOP) within the eye that results in vision loss. Current therapeutic drugs include Timolol and Brimonidine which studies have shown to yield a greater decrease in IOP through combined drug therapy than monotherapy. In 2007 Combigan, an eye drop that combines the therapeutic effects of Timolol and Brimonidine, was approved for use by the FDA. This project proposes a method for treating glaucoma through delivery of Combigan via a contact lens through which the drugs will diffuse into the eye over a period of time. We modeled the diffusion of two drugs, Timolol and Brimonidine, through four layers of the human eye. The drug was delivered via a contact lens, so that the concentration of drug in the aqueous humor would remain above the minimum effective dosage for longer than if it were delivered via eye drops. We calculated the concentration of each drug in all layers of the eye for 12 hours. Our model was verified by experimental data in the published literature. Our model failed to deliver solely Timolol or Brimonidine for 12 hours, which was our goal, but still was significantly more effective than eye drops. However, throughout the twelve hours there was at least one drug in the aqueous humor and since both drugs lower IOP through different mechanisms our model did deliver treat the glaucoma for the whole twelve hours. If it were possible to lower the diffusivity of Timolol through the stroma, this would allow for Timolol to remain longer in the aqueous humor thus making the contacts better at treating glaucoma. A sensitivity analysis demonstrated that our model was robust in the tear film and relatively robust in the contact lens. However, the model was particularly sensitive to diffusivity in the stroma layer, as the stroma acts as the final barrier to aqueous humoral penetration and is quite thick. Brimonidine was delivered at a more constant rate, but at a lower concentration than Timolol. It also took six times longer than Timolol to reach its maximum concentration in the aqueous humor. Drug delivery via contact lenses is a feasible technology as more effective than eye drops, but can be improved by designing a time-release drug that diffuses more slowly. Further research needs to be conducted in order to investigate the practicality of this method

Examining Manual and Visual Response Inhibition Among ADHD Subtypes

This study compared inhibitory functioning among ADHD subtype groups on manual and visual versions of the stop task. Seventy-six children, identified as ADHD/I (n = 16), ADHD/C (n =42), and comparison (n = 18) completed both tasks. Results indicated that both ADHD groups were slower to inhibit responses than the comparison group on both tasks. Comparison children were faster to inhibit than activate responses on both versions of the task. Children in the ADHD groups also demonstrated this robust pattern on the manual task. However, on the visual task, children in the ADHD groups evidenced slowed inhibition comparable to the time required to activate responding. This implies that the visual task is more sensitive to inhibitory impairment in ADHD than the manual task. The ADHD/I group did not differ from children with ADHD/C on most measures, suggesting that the stop task is not effective in differentiating the subtypes. These findings extend work highlighting the role of disinhibition in ADHD, and contrast recent work suggesting divergence between ADHD subtypes

COMPARING OUTCOMES OF DRIED BLOOD SPOT AND PLASMA VIRAL LOAD MONITORING FOR HIV TREATMENT IN RESOURCE-LIMITED SETTINGS USING A MARKOV STATE-TRANSITION MODEL

Background and Objective: People living with HIV who are receiving antiretroviral therapy need to be monitored to evaluate treatment failure. Gold standard plasma viral load is logistically difficult in many resource-limited settings; dried blood spot viral load testing may be a more accessible alternative. A Markov state-transition model was created in order to better evaluate the clinical consequences of this alternative. Outcomes were compared to those of plasma viral load, CD4 immunologic criteria, and clinical criteria for treatment failure. Methods: A Markov state-transition model was created with two cohorts of 10,000 sub-Saharan African adults, one ART naïve cohort and one ART experienced cohort. Outcomes of each cohort were simulated over 5 years of follow-up. Outcomes of interest were the number of patients who died or were virologically failing after five years, events of interest were cumulative misclassifications over five years. Results: Dried blood spot viral load testing was 91% as effective as plasma viral load at averting deaths in the ART naïve cohort and 85% as effective in the ART experienced cohort, compared with clinical symptoms monitoring alone. There were more misclassifications with dried blood spot viral load than with plasma viral load. Both dried blood spot and plasma viral load testing lead to fewer deaths and misclassifications than either clinical criteria for treatment failure alone or immunologic criteria. Estimated programmatic costs for plasma viral load and dried blood spot viral load testing were comparable. Conclusions: Dried blood spot viral load is a good alternative to plasma viral load (when the latter is unavailable), with comparable clinical consequences and costs. Viral load should continue to be the treatment monitoring mode of choice, as clinical and immunologic criteria are inadequate for timely and correct determination of treatment failure. Readers: Catherine Sutcliffe, Ph.D. and David Dowdy, MD, Ph.D

Extent of UV Curing in Highly Loaded Systems for Direct Ink Writing

This study investigates the solidification of material 3D-printed via direct ink writing. This material, consisting of monomers, a photoinitiator and silicon microspheres was extruded onto a printing bed. The material was then irradiated with ultraviolet light to polymerize the monomers. Curing time and thickness of the material were varied in order to determine their effect on the solidification process. Quantification of the extent of cure was done using Fourier transform infrared spectroscopy. The data collected show that the degree of conversion tends to decrease as curing time decreases, but the data is inconclusive as to the specific relationship between time and degree of cure. However, due to a combination of a long method development process and the coronavirus pandemic, work on this project was halted before this trend could be definitely proven.Undergraduat

Controlling Force and Depth in Friction Stir Welding

Feedback control of the penetration force applied to a pin tool in friction stir welding has been found to be a robust and reliable means for controlling the depth of penetration of the tool. This discovery has made it possible to simplify depth control and to weld with greater repeatability, even on workpieces with long weld joints. Prior to this discovery, depths of penetration in friction stir welding were controlled by hard-tooled roller assemblies or by depth actuators controlled by feedback from such external sensors as linear variable-differential transformers or laser-based devices. These means of control are limited: A hard-tooled roller assembly confines a pin tool to a preset depth that cannot be changed easily during the welding process. A measurement by an external sensor is only an indirect indicative of the depth of penetration, and computations to correlate such a measurement with a depth of penetration are vulnerable to error. The present force-feedback approach exploits the proportionality between the depth and the force of penetration Unlike a depth measurement taken by an external sensor, a force measurement can be direct because it can be taken by a sensor coupled directly to the pin tool. The reading can be processed through a modern electronic servo control system to control an actuator to keep the applied penetration force at the desired level. In comparison with the older depth-control methods described above, this method offers greater sensitivity to plasticizing of the workpiece metal and is less sensitive to process noise, resulting in a more consistent process. In an experiment, a tapered panel was friction stir welded while controlling the force of penetration according to this method. The figure is a plot of measurements taken during the experiment, showing that force was controlled with a variation of 200 lb (890 N), resulting in control of the depth of penetration with a variation of 0.004 in. (0.1 mm)

Neurogenic Stunned Myocardium Following an Attempt to Pass a Drug Test

Ingestion of a large volume of free water or other hypotonic solution can cause acute hyponatremia, leading to multiorgan dysfunction. Individuals may attempt to generate a false-negative urine drug screen through increased free water consumption leading to acute hyponatremia requiring emergency medical care. We present the case of a 19-year-old male who presented to a community emergency department for altered mental status after an attempt to generate a false-negative urine drug screen. He ingested a large volume of free water and multiple detoxification solutions, causing acute hyponatremia with resultant cerebral edema and neurogenic stunned myocardium. He required extracorporeal membrane oxygenation therapy with complete recovery of neurologic and cardiac function. Acute hyponatremia from excess free water consumption is a well-documented phenomenon that all emergency providers should be aware of. Prompt identification and management of acute hyponatremia are essential to prevent potentially severe, devastating sequelae, including cerebral edema and cardiopulmonary failure.In addition, extracorporeal membrane oxygenation may be considered in patients with cardiopulmonary failure in the setting of reversible cardiomyopathy, as evidenced in our case