Comparative study of frequency spectrum and energy of electroretinogram oscillatory potentials (OPs) in mammals [abstract]

Abstract only availableFaculty Mentor: Dr. Bo Lei, BiologyPurpose: Oscillatory potentials (OPs) are high frequency, low amplitude wavelets embedded on the ascending limb of the electroretinogram (ERG) b-wave. In human, the bandwidth for OPs recording was recommended at 75~300 Hz. We studied the frequency spectrum and the energy of the OPs in mammals. Methods: Albino (Balb/c) and pigmented (C57BL/6) mice, New Zealand White albino rabbits, cats, and rhesus monkeys were studied. Dark-adapted ERGs were recorded with a bandwidth range of 0.1~1000Hz. We removed the low frequency a- and b-wave contaminations and extracted the OPs digitally with a Butterworth bandpass filter. The extracted OPs were analyzed by Fast Fourier Transform (FFT) to estimate the power spectrum and then converted to a single-sided power spectrum. Summed OPs amplitude (V), peak frequency power (analogous to power of mechanical vibration, in (V*sec)2) and band area energy (V2sec, numerical integration of the power spectrum) were measured. Results: In frequency domain, albino and pigment mice have one major component at 105.810.27 (meanSTD) and 102.2413.31 Hz respectively. Cats have two peaks at 69.43.47 and 133.153.89 Hz. Rabbits and monkeys show multiple peaks. In rabbit, the peaks are at 85.9512.22, 114.9113.35, 152.4619.63 and 194.1118.22 Hz. And in monkey the peaks are at 75.53.27, 137.87 and 161.63 Hz. For OPs power analysis, summed OPs amplitude, peak frequency power and energy are highly correlated. In these animals, mice have the highest OPs energy at 705269.48 (meanSTD, V2sec, albino) and 508.46178.05 (pigmented). The total OPs energies are 11.044.84 in cats, 6.012.96 in rabbits and 25.8616.55 in monkeys. Conclusions: 1. OPs frequency spectrum patterns are different between species. Frequencies of some OPs components are beyond the bandwidth range used in human study. Therefore we suggest adjusting the frequency bandwidth for different species. 2. Multiple frequency peaks may imply different mechanisms. 3. Mice have the highest OPs and may be a good model for OPs study. This project was completed as part of a Capstone requirement

Countries\u27 Involvement in Whaling and the Impacts on Their Tourism Industries

Since the expansion of whale watching as an industry, many countries have converted from whaling as a source of revenue. There are still some countries that partake in whaling and also conduct whale watching tours. The belief is that these two industries cannot coexist in a country and that whaling will have a negative impact on the whale watching sector and the tourism industry all together. A comparative analysis of scholarly articles was conducted alongside a survey to examine the impacts of whaling on the whale watching industries of certain countries. The results showed whaling and whale watching can coexist in a country with no negative impacts on the country\u27s economy

Integrated intensities of carbon dioxide in Nujol solutions

The ratio of the absolute infrared intensity, A₃/A₂, for the parallel mode (2336 cm⁻¹) and the perpendicular mode (658 cm⁻¹) of a nonpolar solute molecule, carbon dioxide, has been determined in a nonpolar solvent, Nujol. The solution ratio (5.0) which has been extrapolated to zero concentration is less than the corresponding gas phase ratio (11.2) as measured by other workers. Also a shift in the absorption peaks to lower frequencies has been observed An attempt has been made to account for these differences between the solution and gas phase

Somatostatin analogue (SMS 201-995) in the management of gastroenteropancreatic tumors and diarrhea syndromes,

SMS 201-995 (Sandostatin) was studied using low doses (50 to 100 [mu]g) administered subcutaneously every 12 hours. A single 50-[mu]g dose of SMS 201-995 effectively controlled gastric acid and blood gastrin levels for 12 hours in three patients with benign gastrinomas and was useful in their perioperative management. Higher doses of the agent (500 to 800 [mu]g per day) had no effect on metastases in one of two patients with metastatic gastrinoma. In the other patient, one tumor shrank but the other continued to grow after three months of treatment while serum gastrin levels did not change. Cultured metastatic tumor tissue from this patient released different forms of gastrin; growth rates varied, independent of uptake of SMS 201-995, and gastrin release increased. A neonate with nesidioblastosis maintained normal blood glucose levels while receiving SMS 201-995 therapy following a 95 percent pancreatic resection. In two elderly patients with organic hypoglycemia--one with a single benign adenoma and one with multiple adenomatosis--the somatostatin analogue did not prolong the hypoglycemia-free interval. In nine patients with carcinoid syndrome, flushing was uniformly controlled with 50 [mu]g of SMS 201-995 administered every eight to 12 hours. One of the nine required exocrine pancreatic replacement. After six months of treatment, three of the nine had no change in tumor size and one had remission of symptoms and stopped treatment. In two patients with vipoma, SMS 201-995 controlled diarrhea and reduced levels of vasoactive intestinal peptide; tumor necrosis occurred in one patient. In a patient with diabetic diarrhea unresponsive to all treatments, SMS 201-995 therapy controlled the diarrhea but did not interfere with control of the diabetes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25940/1/0000002.pd

The investigation of naturally-occurring turbulent spots using thin-film gauges

SIGLEAvailable from British Library Document Supply Centre-DSC:D192250 / BLDSC - British Library Document Supply CentreGBUnited Kingdo