Petroleum Hydrocarbons in Water, Soil and Tomato Plant (Lycopersican esculentum L.) at Basra City, Iraq

This study focused on the determination of Total Petroleum Hydrocarbons (TPH)  concentration in soil, water and tomato plant  Lycopersican esculentum L. at ( root , stem, and leaf ) and biomass of  these plant in four stations  Safwan , shuaiba , Abu Al-kasibe and Garma Ali  at Basra city, Iraq. The result show  that higher concentrations of (TPH) in the soil  and water of Safwan than other stations related to industrial , agricultural and domestic activities which released to environment contaminated to the ground water. The result also show variation in ( TPH ) between Lycopersican esculentum parts ( root , stem and leaf ) , the higher concentration was found in tomato root of  Safwan station compare to other stations and this level was highest than other parts of plant in the same station and other stations. There was positive correlation between petroleum hydrocarbons in soil and plant parts indicated that the plants obtained the TPH from the soil. The total nitrogen was high levels (2.31mg/l) in tomatoes plant in Garmat Ali station while the lowest levels (1.33mg/l ) was in shuaiba station .  Total  phosphorus was higher in Abu kasibe (0.25mg/l ) and low levels (0.11mg/l ) in  Safwan. The percentage of dry mass observed in this order Abu kasibe >  Garma Ali > Safwan >  shuaiba . The bioconcentration factor (BCF) and Translocation factor (TF) which is very important parameters to check the ability of plants for phytoremediation have been calculated

Outperformance and Tracking: A Framework for Optimal Active and Passive Portfolio Management

Portfolio management problems can be broadly divided into two classes of differing investing styles: active and passive. There are a number of philosophical and operational distinctions between these two investment approaches including mandate, complexity, activity level, constraints, and goals. Both forms of portfolio management, however, can involve absolute or relative goals. These goals are distinguished by the involvement (or lack thereof) of external processes in measuring an investor's performance. This thesis presents a unified framework for solving portfolio selection problems arising in both active and passive portfolio management with a focus on relative goals. We are, in particular, interested in stochastic optimization problems related to outperforming a selected benchmark and/or tracking a given portfolio, both natural and essential questions in portfolio management. In the first part of the thesis, we lay the foundation for our framework by introducing a flexible stochastic control problem that captures the range of goals we are interested in. We solve the problem, first, in a simple setting using a dynamic programming approach and derive an explicit closed-form solution for the optimal portfolio. We uncover several important features of the optimal portfolio, most notably, a decomposition result where the optimal solution is expressed in terms of the underlying benchmarks, the growth optimal portfolio, and the minimum variance portfolio. We probe the empirical performance of the optimal portfolio using historical as well as simulated market data. The latter parts of the thesis are dedicated to cases where (i) assets are driven by latent factors and general martingale noise processes, (ii) the market model and preference parameters are stochastic, and (iii) the investor has non-linear utility. These extensions are approached using variational analysis techniques which exploit the convexity of the underlying performance functionals to easily incorporate these additional features. In some instances, the optimal portfolio is characterized via forward backward stochastic differential equations (FBSDEs), and, due to the variational characterization, we establish the existence and uniqueness of solutions to those FBSDEs. The approach we take is also useful for lending interpretability to the solution of the well-known Merton problem when model parameters are stochastic. Moreover, in some special cases, we are able to extend the decomposition result established in the Brownian setting. From a practical perspective, this thesis also presents a fully implementable procedure for computing optimal portfolios for a hidden Markov model of asset prices, including parameter estimation along with filtering results for the hidden state in a general semimartingale setting. The investment performance is demonstrated with out-of-sample backtesting using historical market data.Ph.D

Button Gastrostomy Tubes for Pediatric Patients: A Tertiary Care Center Experience

Background and Objective. Gastrostomy tube insertion is one of the most common procedures performed as a radical choice to overcome feeding difficulty in children. This study is aimed at describing the replacement of a button tube instead of the long tube for feeding infants and children requiring gastrostomies in a tertiary care hospital. Design and Setting. This retrospective cross-sectional descriptive study was conducted between January 2009 and August 2019 at Salmaniya Medical Complex which is a tertiary health care institute in the Kingdom of Bahrain. Subjects and Methods. Both charts and electronic health records of pediatric patients between the ages of 0 and 14 years were reviewed. Data were collected including age, sex, nationality, diagnosis, surgical information (procedure center and procedure performed), complications, and follow-up. Results. Out of 34 patients who underwent gastrostomy tube insertion, 30 patients had their long tube replaced by a button gastrostomy. Majority were males (N=18, 60%). Prolonged nasogastric tube feeding was the main indication of referral (N=17, 56%) followed by feed intolerance (N=6, 17%) and gastroesophageal reflux disease (N=5, 16%). The main underlying diseases at referral were neurological impairment (N=19, 63%) and metabolic disorders (N=4, 13%). There was no significant difference between patients with neurological disorders and other diseases in terms of gender, nationality, or age. Laparotomy with gastrostomy is the main approach used (N=18, 60%). No reported complications of button tubes in 50% of the patients (N=15). Conclusions. Prolonged nasogastric tube feeding is the main indication of referral for gastrostomy tube insertion. Neurological disorders are the main diagnosis for the cases operated upon. Laparotomy with gastrostomy is the procedure of choice at our center. Majority of patients had no reported complications of button tube replacement. These children are likely to benefit from the button tube with fewer complications