Synthesis and photophysical study of unsymmetrical porphyrin arrays

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Population genetics of Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae): differentiation and quantification of overwintering and spring migratory populations in northern Mississippi

Helicoverpa zea, commonly referred to as corn earworm, has been a major pest of corn and cotton, along with many major crops grown in United States. Migration of this pest plays a major role in its distribution and successful survival. Part of the current resistance management strategy for transgenic crops, using non-Bt crops as refuges, is totally based on the movement of the adult populations between the Bt and non-Bt fields, and successful exchange of genetic material between the rare resistant and susceptible populations. To study the movement and migration patterns, and their implications in resistance management, suitable molecular genetic markers were comparatively selected, followed by a study of temporal variations in populations from north Mississippi. The dominant marker system Inter Simple Sequence Repeats (ISSR) was selected for the study based on higher polymorphism (5.0) and PIC (0.34) values compared to Simple Sequence Repeats (SSR) and Sequence Related Amplification Polymorphism (SRAP) marker systems. 53 ISSR loci were used in understanding the temporal variations in H. zea. Percent polymorphism and heterozygosity levels showed variation among the twelve collections tested. Early spring putative migrants were distinct from the rest of the generations. Population differentiation was higher in the beginning of the season and then declined by end of the season (pairwise FST = 0.341, early in March and 0.025, late in August). Average heterozygosity levels recorded were 0.11, coinciding with 1993 and 2002 data. The result of this study supports the existence of spring migration of adults and their contribution to the local gene pool. The extent of genetic exchange between the putative migrants and the local populations varied among three years. There is variation in population densities from migrants and local emergence in one of the three years. The results of this study indicate a need for continuous monitoring for genetic changes and their possible implications for resistance management in transgenic crops in Mississippi

Are plants with anti-cancer activity resistant to crown gall? : A test of hypothesis

The Crown gall tumour assay (CGTA) is one of several bench top bioassays recommended for the rapid screening of plants with anti-cancer activity. The rationale for the use of the bioassay is that the tumorogenic mechanism initiated in plant tissues by _Agrobacterium tumefaciens_ is in many ways similar to that of animals. Several plant species with anti-cancer activity have already been discovered using this bioassay. However till date no explicit test of an association between anti-cancer activity of plants and their resistance to crown gall formation has been demonstrated. Demonstration of an association could have exploratory potential when searching for plants with anti-cancer activity. In this paper, we determined whether or not a statistically significant association between crown gall resistance and anti-cancer activity exists in plants found in existing published data sets. Our results indicate that plants with anti-cancer activity have a higher proportion of their species resistant to crown gall formation compared to a random selection of plants. We discuss the implications of our results especially when prospecting for newer sources of anti-cancer activity in plants

Experimental and computational studies of nanofluids

Thesis (Ph.D.) University of Alaska Fairbanks, 2014The goals of this dissertation were (i) to experimentally investigate the fluid dynamic and heat transfer performance of nanofluids in a circular tube, (ii) to study the influence of temperature and particle volumetric concentration of nanofluids on thermophysical properties, heat transfer and pumping power, (iii) to measure the rheological properties of various nanofluids and (iv) to investigate using a computational fluid dynamic (CFD) technique the performance of nanofluids in the flat tube of a radiator. Nanofluids are a new class of fluids prepared by dispersing nanoparticles with average sizes of less than 100 nm in traditional heat transfer fluids such as water, oil, ethylene glycol and propylene glycol. In cold regions of the world, the choice of base fluid for heat transfer applications is an ethylene glycol or propylene glycol mixed with water in different proportions. In the present research, a 60% ethylene glycol (EG) or propylene glycol (PG) and 40% water (W) by mass fluid mixture (60:40 EG/W or 60:40 PG/W) was used as a base fluid, which provides freeze protection to a very low level of temperature. Experiments were conducted to measure the convective heat transfer coefficient and pressure loss of nanofluids flowing in a circular tube in the fully developed turbulent regime. The experimental measurements were carried out for aluminum oxide (Al₂O₃), copper oxide (CuO) and silicon dioxide (SiO₂) nanoparticles dispersed in 60:40 EG/W base fluid. Experiments revealed that the heat transfer coefficient of nanofluids showed an increase with the particle volumetric concentration. Pressure loss was also observed to increase with the nanoparticle volumetric concentration. New correlations for the Nusselt number and the friction factor were developed. The effects of temperature and particle volumetric concentration on different thermophysical properties (e.g. viscosity, thermal conductivity, specific heat and density) and subsequently on the Prandtl number, Reynolds number and Nusselt number of three nanofluids were investigated. The three nanofluids studied were Al₂O₃, CuO and SiO₂ nanoparticles dispersed in a base fluid of 60:40 EG/W. Results showed that the Prandtl number of nanofluids increased with increasing particle volumetric concentration and decreased with an increase in the temperature. The Reynolds number of nanofluids for a specified geometry and velocity increased with an increase in temperature and decreased with an increase in particle volumetric concentration. The Mouromtseff numbers of nanofluids were higher than those of the conventional fluids under both laminar and turbulent flow conditions, proving the superiority of nanofluids in electronic cooling applications. Experiments were performed to investigate the rheological properties of various nanoparticles dispersed in a 60:40 PG/W base fluid. The nanoparticles studied were; Al₂O₃, CuO, SiO₂, zinc oxide (ZnO), titanium oxide (TiO₂) with particle diameters ranging from 15 to 75 nm and particle volumetric concentrations of up to 6%. All the nanofluids exhibited a non-Newtonian Bingham plastic behavior at the lower temperature range of 243 K to 273 K and a Newtonian behavior in the temperature range of 273 K to 363 K. A new correlation was developed for the viscosity of nanofluids as a function of temperature, particle volumetric concentration, particle diameter, the properties of nanoparticles and those of the base fluid. Measurements were also conducted for single wall, bamboo-like structured and hollow structured multi-wall carbon nanotubes dispersed in a base fluid of 20:80 PG/W. A low-volume concentration (0.229%) of these carbon nanotubes (CNT) nanofluids revealed a non-Newtonian behavior over a measured temperature range of 273 K to 363 K. From the experimental data, a new correlation was developed which related viscosity to temperature and the Péclet number for CNT nanofluids. A three-dimensional CFD study was performed to analyze the heat transfer and fluid dynamic performance of nanofluids flowing in the turbulent regime in a flat tube of an automotive radiator. Computations were carried out for the Al₂O₃ and CuO nanoparticles of 0 to 6% particle volumetric concentrations dispersed in a base fluid of 60:40 EG/W. The numerical study revealed that under equal pumping power basis, the Al₂O₃ and CuO nanofluids up to 3% and 2% particle volumetric concentrations respectively, provided higher heat transfer coefficients than those provided by the base fluid. From this study, several new correlations to determine the Nusselt number and friction factor for the nanofluids flowing in the flat tubes of a radiator were developed for the entrance as well as the fully developed regions

Population genetics of Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae): differentiation and quantification of overwintering and spring migratory populations in northern Mississippi

Helicoverpa zea, commonly referred to as corn earworm, has been a major pest of corn and cotton, along with many major crops grown in United States. Migration of this pest plays a major role in its distribution and successful survival. Part of the current resistance management strategy for transgenic crops, using non-Bt crops as refuges, is totally based on the movement of the adult populations between the Bt and non-Bt fields, and successful exchange of genetic material between the rare resistant and susceptible populations. To study the movement and migration patterns, and their implications in resistance management, suitable molecular genetic markers were comparatively selected, followed by a study of temporal variations in populations from north Mississippi. The dominant marker system Inter Simple Sequence Repeats (ISSR) was selected for the study based on higher polymorphism (5.0) and PIC (0.34) values compared to Simple Sequence Repeats (SSR) and Sequence Related Amplification Polymorphism (SRAP) marker systems. 53 ISSR loci were used in understanding the temporal variations in H. zea. Percent polymorphism and heterozygosity levels showed variation among the twelve collections tested. Early spring putative migrants were distinct from the rest of the generations. Population differentiation was higher in the beginning of the season and then declined by end of the season (pairwise FST = 0.341, early in March and 0.025, late in August). Average heterozygosity levels recorded were 0.11, coinciding with 1993 and 2002 data. The result of this study supports the existence of spring migration of adults and their contribution to the local gene pool. The extent of genetic exchange between the putative migrants and the local populations varied among three years. There is variation in population densities from migrants and local emergence in one of the three years. The results of this study indicate a need for continuous monitoring for genetic changes and their possible implications for resistance management in transgenic crops in Mississippi

Balancing Competing Corporate Objectives: The Case of Texmark Real Estate Company

As William Sullivan walked to his car to begin the commute home after a long day at work, he considered the different options before him. As the CEO of the Texmark Real Estate Company (TexREC), Sullivan was concerned about the future of the company he had been leading for four years now. During this time, TexREC had enjoyed considerable success, nearly doubling the value of assets under management to $7.5 billion; however, the rapid growth also meant new challenges for the company. Sullivan was focused on finding new lines of business and untapped markets with the potential for high risk-adjusted returns, including potential expansion overseas if the right opportunity presented itself. Sullivan innately understood that finding the right talent to lead such initiatives was a crucial first step

Need for national policy to recover endangered species

India is bestowed with world’s four mega-biodiversity hotspots. In fact, India is the only country that is blessed so many of these biodiversity regions. However, this rich biodiversity is under severe threat owing to the increasing population as well as indiscriminate extraction from natural populations. Unplanned land use in the name of economic development have rendered a number of species in the under the threatened category. In the most recent update, the International Union for Conservation of Nature (IUCN, 2016) assigned a total of 1052 species as red listed. Of these, 75 animals and 77 plants are in the critically endangered list with many others being in the endangered and vulnerable categories. What is even more worrying is the fact that a large number of species have been reduced to incredibly small numbers due to either habitat degradation or illegal hunting/harvesting. Unless immediate measures are taken up, a number of these species could be in the red-list within a matter of few years. Unfortunately as of now, except for few attempts, there has been no concerted program in the country to address the restoration of the threatened species

DEVELOPMENT AND PHARMACOKINETICS OF CURCUMIN LOADED BETA CAROTENE NANOPARTICLES IN RATS

Objective: The main objective of this research work is to improve the bioavailability of curcumin using beta carotene nanoparticles in experimental animals. Methods: Curcumin-loaded beta carotene nanoparticles (NPs) have been prepared by emulsion–diffusion–evaporation method. Beta carotene and ethyl acetate were used to formulate NPs, and poly (vinyl alcohol) was used as a stabilizer. The emulsion diffusion evaporation method was used to prepare the nanoparticles and bioavailability and various pharmacokinetic parameters were compared with curcumin suspension in rats. Results: The nanoparticles were successfully prepared using beta carotene and curcumin and the drug loading was almost 93% of the initial weight. Particle sizes were below 200 nm with negative zeta potentials. Comparing the pharmacokinetic parameters of curcumin loaded nanoparticles (Cmax, Tmax, Kel, and AUC were 105 µg/ml, 2 h, 0.23/h, and 1629 µg.hr/ml) with pure curcumin (Cmax, Tmax, Kel and AUC 16 µg/ml, 1h, 0.275/h and 58 µg.hr/ml) indicated a drastic improvement in bioavailability of curcumin. Conclusion: The relative bioavailability was almost increased 30 times with beta carotene nanoparticles