WEB.ISOD.ES CEL

For her CEL, Aman interned at WEB.ISOD.ES in London, Ontario, working on producing a documentary discussing the recent implementation of Basic Income by the Conservative Provincial government. Aman learned valuable research skills and communications skills while working on this project and was excited to work in politics

Double-stranded RNA binding motifs and recognition of RNA-editing substrates

RNA editing, the changing of a nucleotide sequence from that encoded by the gene, can both diversify and re code the genome. Adenosine deaminases that act on RNA (ADARs) are one class of enzymes that edit RNA by causing adenosine to inosine (functionally similar to guanine) mutations in RNA that is largely double stranded. These mutations are essential to neural receptor activity, and have been linked to clinical depression, schizophrenia, epileptic seizures, and amyotrophic lateral sclerosis. The ADAR enzyme consists of a catalytic domain, whose structure has been previously determined, as well as one or more double stranded RNA binding motifs (dsRBMs) depending on the organism and type of ADAR. Given the high specificity of RNA editing by ADARs, dsRBM structure plays a key role in substrate recognition. By understanding the mechanism of RNA editing, specifically why ADARs recognize only certain double stranded RNA substrates, this project will shed light on the functional implications of RNA editing and could possibly lead to further understanding of multiple clinical diseases. The goal of this study is to determine the structure of dsRBMs from various species in both the absence and presence of RNA. The RBMs have been truncated from the rest of the protein due to the highly dynamic nature of the ADAR enzyme. A unique construct utilizing a cysteine protease domain has been employed in the cloning process to improve the solubility of the RBM as well as provide a means to better track the small RBM (7-8 kDA) during purification. The structure will be determined by X-ray diffraction of crystals of the dsRBM constructs. This determined structure will be critical in understanding why RNA editing is highly specific

A comparative study of laser and thermal annealing of zinc ion implanted gallium arsenide.

A comparative study of laser and thermal annealing of Zn and Cd ion implanted GaAs is presented in this thesis. The techniques used were Rutherford backscattering, transmission electron microscopy, Hall effect and sheet resistivity measurements. The variation in the properties of the implanted GaAs with implantation temperature, ion dose, ion energy and annealing temperature were investigated. For laser annealing they were studied as a function of laser pulse length, laser energy density and multiple irradiations. For the thermal annealing process, the results indicated that an annealing temperature of 900°C was needed for perfect recrystallization and maximum electrical (~86%) activation. In the temperature range 650 to 800°C the sheet hole concentration increased with increasing dose up to a dose of about 1x10[14] Zn[+] /cm[2] and above this dose it saturated between (1-2)x10[14] holes/cm[2] when implanted at room temperature. Results were similar for implant energies of 60 to 450 keV. For samples implanted at 200°C, the sheet hole concentration increased with increasing dose and the maximum value observed was in the range (1-2)x10[19] holes/cm3. Irradiation with a freely generated ruby laser produced electrical activities from about 27% to 50% and peak concentrations from about 1x10[19] to 7x10[19] holes/cm[3]. RBS measurements showed that residual damage still remained in these samples. In contrast a Q-switched ruby laser pulse produced complete recrystallization (X[min] = 4%) with electrical activities up to 100%. The highest peak hole concentration was measured to be about 1x10[20] holes/cm[3]. Profiles of the implanted ions are shown to depend on most of the parameters mentioned above. The possible explanations for the diffusion of Zn and Cd in thermal annealing and laser annealing samples are discussed

An Assessment of Pyridoxine as a Biological Response Modifier During Colon Carcinogenesis

The main objective of this proposal was to investigate the effect of vitamin B6 on colon carcinogenesis in vivo. Two in vivo studies were conducted to determine the role of vitamin B6 as a biological modifier of colon carcinogenesis. It is hypothesized that vitamin B6 may serve as an antioxidant in vivo and will modulate colon carcinogenesis. In the first study, a 2X3 factorial experimental design was used to determine if three different levels of vitamin B6, classified as low, normal and high in conjunction with two different levels of protein intake, classified as normal or high, will affect post-initiation stages of colon carcinogenesis, in Sprague-Dawley rats. Male Sprague-Dawley male were injected with azoxymethane for two weeks (15mg/kg/week) and then one week later they were allocated to different dietary treatment groups. After eight weeks, the effects of dietary treatment on hematological status, oxidative stress markers and antioxidant enzymes, as well as enumeration of preneoplastic lesions, aberrant crypt foci (ACF), were evaluated. The lowest level of vitamin B6 intake with a high protein diet reduced the growth and development of ACF. Vitamin B6 had no significant effect on the oxidative stress markers. The level of protein was an important variable in modulating the levels of 3-nitrotyrosine and 8-OH-DG which were lower in high protein groups than normal protein counterparts. The objective of the second study was to investigate if a supraphysiological (5 fold higher than normal level) dosage of vitamin B6 could have an antioxidant effect in a metabolically compromised state like obesity and thereby lower the risk of colon cancer. Female Zucker obese (Zk-OB) rats received normal (Zk-OBN, 7 mg/kg) or high (Zk-OBH, 35 mg/kg) vitamin B6 (Pyridoxine-HCl) diets two weeks prior to, during and six weeks following injection with colon carcinogen AOM. The effects of supplemental vitamin B6 on hematological status, oxidative stress markers and antioxidant enzymes, as well as enumeration of ACF were carried out. High intake of vitamin B6 significantly lowered liver weights and plasma cholesterol compared to the normal intake (p≤0.05). Zk-OBH rats had significantly reduced number of ACF compared to Zk-OBN (p≤0.05). Hepatic GSH increased in the ZK-OBH group with a concomitant decrease in GPx activity. The findings demonstrate that in Zucker Obese rats, a high B6 intake augmented the antioxidant potential and decreased sensitivity to colon carcinogenesis. These findings suggest that high vitamin B6 plays an important therapeutic role in the compromised state of obesity

On the Lie ring of derivations of a semiprime ring

We prove that the Lie ring of derivations of a semiprime ring is either trivial or non-nilpotent

Notes on the Bionomics of the Pink Stem Borer Sesamia inferens Walker (Lepidoptera: Noctuidae): An Upcoming Pest of Wheat in India

Wheat cultivation is of great significance in North-western plains of India and the crop was hitherto considered as almost free from serious insect attack. Recently, Pink stem borer (PSB), Sesamia inferens Walker (Lepidoptera: Noctuidae) has emerged as a new pest and is likely to pose serious threat to the successful cultivation of wheat in the North-western plains of India under largely adopted rice-wheat cropping system. Because of the paucity of data on the developmental biology of PSB on wheat crop regarding this emerging problem of insect damage, studies were initiated on biology of PSB under field as well as screenhouse conditions during seasons of 2010–2011 and 2011–2012. This is the first report on biology of PSB on wheat which indicated that the pest was able to survive well/build up populations on wheat and able to complete its life cycle. It laid eggs either at the base of wheat plant near to soil level or on soil-surface or in the left over stubble of rice plants. Eggs hatched within 7.40±0.08 days and the mean larval duration was 68.52±1.55 days. In the course of development, it passed through 8 larval instars and pupation took place near or within the left over rice stubble. Pupal period was 36.05±0.36 days in male while 37.78±0.17 days in female. The survival of adult moths was 5.31±0.26 days in male while 6.61±0.26 days in female. The mean fecundity was 118.38±11.93 eggs and 89.15 per cent of eggs hatched. The total life cycle took 116.92±2.17 and 119.95±2.05 days in males and females, respectively