MiRNA expression changes in arsenic-induced skin cancer in vitro and in vivo.

Arsenic is a naturally prevalent metalloid. Chronic arsenic ingestion through drinking water causes skin cancer. Arsenic-induced cancer mechanisms are not well defined. Epigenetic changes, including microRNA expression changes, might be playing a role. This dissertation investigates the impact of miRNA expression changes in arsenic-induced skin cancer. MiRNA expression was measure and compared using 3 different techniques, RTq-PCR, hybridization arrays and RNA-sequencing. MiRNAs differential expression in skin lesions was phenotype- and stage-related. Immortalized human keratinocytes (HaCaT) were transformed by chronic low arsenite exposure serving as a model for arsenic-induced skin carcinogenesis. Early changes in miRNAs and target mRNAs contribute to arsenic-induced carcinogenesis. Throughout the time course of arsenic exposure, dysregulation of cells’ growth and cancer-related pathways were identified. Comparisons between the miRNA profiles in lesions and cells predict some miRNAs may serve as biomarkers and/or therapeutic targets for arsenic-induced tumors. This dissertation provides strong evidences of epigenetic changes related to carcinogenesis in arsenic-induced skin cancer

The role of pesticides in non-alcoholic fatty liver disease (NAFLD).

NAFLD, the most common form of liver disease worldwide, is caused by various factors including industrial chemicals and pesticides exposure. Annually, 5.2 billion pounds of pesticides are used worldwide and can contribute to liver disease, but their role is modestly studied. We hypothesize that pesticides contaminating food supply can worsen diet-induced steatosis via xenobiotic receptor activation. Two human and two rodent databases were utilized and 85% of the 330 chemicals identified associated with NAFLD were pesticides. Eight were selected for evaluating hepatic receptor activation in vitro. The majority including DDT activated hPXR/CAR and mPXR. DDT (100 mg/kg) was studied in vivo in a diet-induced obesity (DIO) model. DDT upregulated Cyp2b10 (CAR target) in control diet-fed mice. DDT decreased adiposity, but it did not affect weight gain, food consumption or insulin resistance. In conclusion, DDT improved steatosis, but it did not affect NAFLD, obesity, liver damage or diabetes caused by DIO

Postharvest quality of papaya fruit (carica papaya)associated with applications of calcium and chitosan

A study was conducted to evaluate calcium and chitosan effects on storage life, anthracnose disease incidence, quality, physiological changes and enzymes activities of papaya. Mature green papaya fruits of colour index 2 were used for conducting the experiments. In the first experiment, papaya fruits were treated with different concentrations of chitosan, 0, 0.5, 0.75 and 1%, and stored at 13±1°C for 28 days. Chitosan concentrations 0.75 and 1% showed the best effect on extending storage life by 26 and 28 days, respectively while maintaining the quality compared with 0.5% and control. However, there was no significant difference between 0.75 and 1% treatments. In the second experiment, calcium at different concentrations 1.5, 2.5 or 3.5% were applied as a postharvest treatment for papaya fruits using vacuum infiltration and dip application techniques. Calcium infiltration at 2.5% significantly extended the storage life up to 26 days and retained the quality better than other treatments. Since, chitosan with its coating ability to retard weight loss of fruits and antifungal property while alcium provides better fruit firmness, a study was conducted using calcium at different concentrations 1.5, 2.5 or 3.5% and chitosan at 0.75% or their combination. From the in vitro experiment, calcium at different concentrations had slight inhibition effects on C. gloeosporioides spore germination but did not show any significant effects on mycelial growth. Chitosan treatment significantly inhibited spore germination and mycelia growth compared to calcium treatments and their control. Calcium at 2.5 in combination with chitosan (0.75%) had significantly better effects on inhibition of spore germination and mycelial growth of C. gloeosporioides compared to calcium individual treatments. Anthracnose disease incidence (%) on papaya fruits was significantly controlled (5.6%) using calcium at 2.5% and chitosan compared with the other treatments. This combined treatment of 2.5% calcium with chitosan 0.75% extended the storage life up to 33 days while retaining the quality of fruits compared with the other treatments. To look at the effect of this combined treatment over different storage intervals, experiment has been conducted. The effectiveness of the treatments was assessed by evaluating their impacts on the quality characteristics during 35 days of storage period. Calcium 2.5% in combination with chitosan 0.75% treatment had better retention of fruits firmness, weight loss, retarding changes in color and preserving chemical characteristics during storage compared to the other treatments. Furthermore, experiment on the physiological and ultrastructures changes and enzyme activities during storage was conducted. The combined treatment of calcium 2.5% and chitosan 0.75% markedly reduced the respiration rate, ethylene production and maintaining the integrity of the waxy cuticle and epidermal cells. Polygalacutronase (PG) degrading enzyme activity was retarded and the induction of defense response of fruits against anthracnose disease was enhanced by eliciting peroxidase enzyme activities (POD)

Optimal Configuration of Regional Water Supply Systems (WASOPT2)

Any water supply system can be conceptualized as consisting of three componenets--source development facilities (including treatment), transmission facilities, and a distribution network. The scope of this report is limited to the first two--the source related facilities upstream from the distribution network. In the mathematical modeling of regional rural systems, the number of variables, and hence the size of the model, increases rapidly as the number of system componenets and their alternative designs increase. Regardless of the method of solution, manual preparation of large models is cumbersome and is vulnerable to human error both in the computations of the matrix coefficients as well as in the format requirements. This research is aimed at developing a flexible matrix generator for the general rural water supply problem and alternative solution methods that can be used for especially large problems. The Mixed Integer Programming (MIP) method is particularly expensive to use for large problems and is not practical if the number of variables approaches a hundred or so, while the laternative solution methods can handle hundreds of variables. A real-world application problem is solved using the MIP and the three alternative methods developed during this research. These include the continuous, the nonlinear discrete, and the objective bounding methods. The solutions are compared and conclusions drawn as to the conditions under which the different methods are recommended