Wanderer

These photos are the result of having pursued an MFA during the COVID pandemic. I chose a mode of photography that would keep me away from people and I focused on what I could capture “on the road.” These 30 photos explore visual tropes related to movement, thresholds, barriers, and symbolic encounters. They capture moments of joy and contemplation. Each photo works individually, but I have edited and arranged them in the gallery to create something between a narrative and a non-narrative that approximates the experience of what traveling to capture them was like, both on foot and in motion, in rural and in urban settings

An Experimental Approach to Comparing Trust in Pastoral and Non-Pastoral Australia

It is generally held that rural Australians are more cooperative in character than their urban counterparts. To explore one aspect of this notion, we conducted an experiment which compared trust and trustworthiness among a sample of Australian senior high school students which included students with both pastoral and non-pastoral backgrounds. While student behaviour is unlikely to mimic adult behaviour, any significant differences between pastoral and non-pastoral students would suggest differences do exist between the social norms that guide pastoral and non-pastoral communities. We repeated our experiment at three different schools containing students from both pastoral and non-pastoral backgrounds, allowing us to draw comparisons. In total 78 students participated. Our experiments were based on similar experiments that have been applied across a range of contexts internationally (trust game/investment game). We did not find evidence of differences between students with pastoral and non-pastoral backgrounds, either in the level of trust in others or in trustworthiness, though our methods probably have a bias towards this conclusion. Our results concurred with other studies in showing that social distance is an important determinant of the level of cooperation.rural urban relations, economic behaviour, culture, arid zones, semiarid zones, pastoral society

An Analysis of the Supreme Court\u27s Reliance on Racial Stigma as a Constitutional Concept in Affirmative Action Cases

The Article\u27s focus is confined to discussions of race-based affirmative action; it does not consider stigmatization arguments in the context of discrimination involving gender or disabilities, for example. Further, the Article\u27s scope is limited to the stigmatization issue as between Whites and African Americans. Although similar issues exist with respect to other ethnic or racial groups, we view the White/African American paradigm as providing the clearest framework for analysis. Moreover, the cases of Plessy v. Ferguson and Brown v. Board of Education, joint progenitors of stigmatization as a concept having constitutional significance in interpreting the Equal Protection Clause of the Fourteenth Amendment, arose within that paradigm and discuss the stigma concept in that context

Call for Advanced Training and Diet Programs Due to High Metabolic Demands of Firefighting

Firefighters (FF) require high levels of muscular strength and cardiovascular fitness in order to meet the demands of firefighting. The National Fire Protection Association reported FF in the US are not meeting health and fitness recommendations, which results in poor simulated and on-duty occupational performance. PURPOSE: to examine the demands and stress placed on FF during a series of simulated FF specific physical tasks and identify potential strategies to improve FF specific performance variables. METHODS: Twenty apparently healthy male professional structural FF completed a battery of nine FF specific exercises/movements during a simulated fire ground test (FGT). The exercise included the following: dry hose carry, charged hose carry, low-room search, chainsaw roof walk, forced entry task, ladder carry, stair climb with hose pack, 10 full extension, and victim carry. A familiarization trial was completed prior to testing. Lactate, time to completion, air tank depletion (measured in PSI) and heart rate were recorded. RESULTS: Lactate levels were significantly higher during post-testing compared to resting levels (p \u3c 0.001). Lactate levels were taken before and two-, four-, six, and eight-minutes after the FGT (1.4 ±0.5 mmol/L, 13.2 ±1.7 mmol/L, 13.3 ±2.2 mmol/L, 12.8 ±1.6 mmol/L, 12.2 ±1.9 mmol/L, respectively). Additionally, heart rate (bpm) at timepoints two and three were significantly higher compared to timepoint one (p \u3c 0.001). Heart rate increased significantly from pre FGT 91.2 ±12.4 bpm to 179.2 ±9.5 bpm during the FGT, which was higher than 95% age-predicted max heart rate. In terms of air tank depletion, the FGT resulted in a significant depletion in tank (p \u3c 0.001). A 45-minute air tank depleted approximately 51% within seven minutes. The average FGT time-to-completion was 7.5-minutes. CONCLUSION: Firefighting requires high levels of physical fitness to carry out the job specific tasks. Standardized resistance training programs and dietary interventions are warranted to identify optimal strategies to improve FF specific performance during simulated testing and on-duty tasks. Tactical resistance programming and diet interventions may reduce the impact of physiological and psychological stressors while improving FF ability to meet metabolic and job-specific demands

First-Principles Calculations of Auger Recombination in Optoelectronic Materials

Lighting currently uses around 15% of global energy expenditure. Reducing this energy usage would be an important part of reducing the effects of global climate change. LEDs (light-emitting diodes) could be a more efficient light source than traditional incandescent or compact-fluorescent bulbs. However, they currently suffer from ‘efficiency droop’ — as the power through the device is increased, the efficiency goes down. While the exact cause of droop is not known completely, one effect is the Auger recombination process. Auger recombination involves an electron and hole recombination which transfers energy to another carrier (rather than emitting a photon as in the desired radiative process). Auger recombination comes in many forms and can be assisted by phonons and alloys which allow Auger to occur when it would otherwise be prevented by momentum conservation. Reducing the Auger recombination process in LED materials would allow for manufacturers to use fewer LEDs in their bulbs, reducing costs and encouraging widespread LED adoption. The challenge to reducing Auger is quantifying its impact. Experimental determination of Auger can be confounded by many factors and reported rates for Auger often vary over orders of magnitude. Theoretical determination of Auger recombination is also difficult because of the complexity of the equations involved. In this situation, computation can be an important tool to understand the underlying physics. In particular, this thesis focuses on first-principles calculations, which solve Schödinger’s equation directly rather than relying on existing experimental data. This allows these calculations to be predictive of experiment and can guide future research on more efficient materials. While many open-source and commercial options exist for codes that will solve Schödinger’s equation using Density Functional Theory, there is not an available code to solve for recombination rates. As part of this thesis, code used to find the Auger recombination rates was expanded and improved. This was then used to study various optoelectronic materials. The group-III nitrides are widely used for making LEDs. GaN is popular in making blue LEDs, but other materials in this family have uses. InN has a band gap in the infrared, and could be used for telecommunication purposes. We studied the Auger process in InN and found that it is dominated by the direct Auger process, as expected for its small band gap. We also found that at high carrier densities, Auger was primarily reduced by carrier screening rather than phase-space filling. On the other hand, AlGaN alloys could be used to create UV LEDs, with applications in sterilization and sensing. We studied Auger in AlGaN alloys of three compositions and modeled expanding these Auger values throughout the entire alloy spectrum. We expected to find the maximum alloy-assisted Auger at the 50/50 alloy, but found the opposite trend. This unintuitive result warrants further study. Scintillators are another type of device that emits light when struck by radiation. Auger affects these devices by suppressing light output and making it difficult to identify what the elemental source of the original radiation was. We studied Auger in NaI and found that the phonon-assisted process dominates as expected by the large gap of the material. This methodology and code has shed light on nonradiative carrier combination in optoelectronic materials and devices and can continue to be used in future studies.PHDApplied PhysicsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/149807/1/mcala_1.pd

Studies on the sterol and lipid composition of bile

The initial stage of these investigations was concerned with estimates of the precision of analytical methods for the determination of phospholipids, cholesterol and bile salts in human and canine bile samples. During the course of these studies a new method for the determination of cholesterol was developed. This was based on the determination of the hexoses present in the side chain at C(3) in cholesterol digitonide, by means of the cysteine-sulphuric acid reaction. The procedure was found to give an approximate tenfold gain in sensitivity over the Sperry and Webb method, and was about six times more sensitivity than procedures using the anthrone reaction. Since bile samples in these investigations were stored in the frozen state, the effect of freezing and thawing on cholesterol solubilisation in bile was studied. Data were presented to show that considerable amounts of cholesterol were brought out of solution in gallbladder bile from patients with gallstones as a result of freezing and thawing. It was suggested that this finding might explain some of the discrepancies found in the literature. The first part of the thesis reported a study that was made of the supposed increased in the incidence of gallstone disease in patients who have undergone vagotomy. Initially it was shown that bile obtained by duodenal intubation following the injection of cholecystokinin was representative of gallbladder bile. This method was then used to obtain bile samples from a group pre-operative duodenal ulcer patients and pre-operative gallstone patients, the latter group serving as controls. Samples of bile so obtained were analysed from cholesterol, phospholipide and bile salts. When the relative compositions were plotted on phase diagrams, bile from gallstone patients lay close the limits of cholesterol solubility, whereas bile from pre-operative duodenal ulcer patients lay within the micellar zone. The determinations were then repeated on the duodenal ulcer patients after vagotomy and drainage. No significant changes could be found in bile from these patients in the 8 to 10 period after operation. This did not exclude the possibility of later changes in bile composition that might predispose to gallstone formation. In the second part of this thesis, a study was made of the sterol and lipid composition of hepatic and gallbladder bile in patients with diagrams, hepatic bile from these patients was found to be saturated with cholesterol, whereas gallbladder bile lay within the micellar zone. It was concluded that supersaturation of hepatic bile is not the sole factor responsible for the precipitation of cholesterol. Part 3 described a model for the study of bile flow in the dog. This permitted total diversion of bile composition were found to take place if ten per cent was sampled for chemical analysis. There was therefore no significant diversion of the enterohepatic circulation of bile salts. When the relative composition of canine gallbladder and hepatic bile were compared, the former was found to contain significantly more bile salts and significantly less phospholipid than the latter. There was no significant difference in the relative amounts of cholesterol. When these data were plotted on phase diagrams, both gallbladder and hepatic bile lay well within the micellar zone. This might explain why cholesterol gallstones are rare in dogs. The bile salt excretion and pool size were measured in dogs by a direct method. With the gallbladder intact, the pool size was 6.60 m-moles +/- S.E. 0.7. After cholecystectomy it was 4.6 m-moles +/- S.E. 0.3. From these values and measurement of the bile salt output it was calculated that in the cholecystectomised dog, the pool size circulated about 6 times per diem. The pool size was found to be large when compared with man and monkey. This might reflect differences in the eating habits of the different species. Patients with gallstones are reported to have a reduced bile salt pool. This was studied in dogs by measuring the bile salt pool before and after cholecystectomy. There was a significant reduction in the pool size. Since removal of the gallbladder reduces the storage space of the extra-hepatic biliary tree, it was concluded that in patients the presence of stones in the gallbladder may effectively reduce the pool size. This suggested that a reduced bile salt pool in gallstone patients may be a result and not a cause of the disease. The final part of the thesis elaborates on the clinical observations made in Part 1 in which studies were made on bile composition before and after vagotomy. Dogs with chronic biliary fistulae were used to study the effect of vagal stimulation by insulin hypoglycaemia. Data was presented to show that vagal stimulation by this means produced a water choleresis. This could be blocked by stropine either when given together with insulin, or one hour after insulin. This suggested that insulin choleresis is mediated via the vagus. Atropine was also shown to inhibit the secretion of bile salts, phospholipids and cholesterol. This observation was made here for the first time