Efficient management of backtracking in and-parallelism

A backtracking algorithm for AND-Parallelism and its implementation at the Abstract Machine level are presented: first, a class of AND-Parallelism models based on goal independence is defined, and a generalized version of Restricted AND-Parallelism (RAP) introduced as characteristic of this class. A simple and efficient backtracking algorithm for R A P is then discussed. An implementation scheme is presented for this algorithm which offers minimum overhead, while retaining the performance and storage economy of sequent ial implementations and taking advantage of goal independence to avoid unnecessary backtracking ("restricted intelligent backtracking"). Finally, the implementation of backtracking in sequential and AND-Parallcl systems is explained through a number of examples

MINDFUL CONSUMER BEHAVIOR: A CROSS-CULTURAL COMPARISON

We compare Lebanese and American consumers on mindful consumption behavior. We define mindful consumers as individuals who, in all stages of consumer behavior, are aware of themselves, their communities and the society at large and behave in ways that contribute to the well-being of all these entities. We conducted a two-phase survey on a total of 210 consumers, 97 in the USA and 113 in Lebanon. We found significant impacts of consumers’ life beliefs such as satisfaction with life, locus of control, and temporal focus and of life values on different aspects of their mindful behavior

Catalytic Degradation of 4-Ethylpyridine in Water by Heterogeneous Photo-Fenton Process

In this work, the degradation of 4-ethylpyridine (4EP) in water by a heterogeneous photo-Fenton process (H2O2/Fe3O4/ultraviolet irradiation (UV)) was investigated. More rapid and effective 4EP degradation was obtained with H2O2/Fe3O4/UV than Fenton-like (H2O2/Fe3O4) and UV/H2O2, which is due to the larger production of hydroxyl radicals from the chemical and photolytic decomposition of H2O2. The operational conditions were varied during 4EP degradation experiments to evaluate the effects of pH, catalyst, concentration, and temperature on the kinetics and efficiency of H2O2/Fe3O4/UV oxidation. Under optimal conditions (100 mg/L 4EP, [H2O2] = 1000 mg/L, Fe3O4 = 40 mg/L, pH = 3 and room temperature, 300 rpm), 4EP was totally declined and more than 93% of the total organic carbon (TOC) was eliminated. Liquid chromatography analysis confirmed the formation of aromatic and aliphatic intermediates (4-hydroxypyridine, 4-pyridone, malonic, oxalic, and formic acids) that resulted in being mineralized. Ion chromatography analysis demonstrated the stoichiometric release of NH4+ ions during 4EP degradation by heterogeneous photo-Fenton oxidation. The reuse of the heterogeneous catalyst was evaluated after chemical and heat treatment at different temperatures. The heat-treated catalyst at 500 °C presented similar activity than the pristine Fe3O4. Accordingly, heterogeneous photo-Fenton oxidation can be an alternative method to treat wastewaters and groundwater contaminated with pyridine derivatives and other organic micropollutants. The combination of heterogeneous photo-Fenton oxidation with classical biological methods can be proposed to reduce the overall cost of the treatment in large-scale water treatment plants. View Full-TextQatar National Librar

Evaluation of in vitro antitoxoplasmal activity of some medicinal plants collected from Al Qassim, Saudi Arabia

Toxoplasmosis is a protozoal parasitic infection with serious consequences for immunocompromised people. The commercial pharmaceuticals used for treatment cause adverse effects and cannot provide a 100% cure. We investigated on antitoxoplasmal activities of eleven medicinal plants from seven different families used in the Al Qassim region of Saudi Arabia against infectious diseases. The plants were extracted in methanol. The methanolic extracts were evaluated against Toxoplasma gondii and the Vero cell line using the MTT assay. The results obtained revealed the maximum inhibitory effects of extracts of Citrullus colocynthis, Blepharis ciliaris and Aerva javanica with IC50 values of 27.7, 65.2 and 78 µg/ml, respectively against the parasite. However, at the effective levels of antitoxoplasmal activity extracts, of all the above plant species showed different degrees of cytotoxicity against the Vero cell line with SI values of 1.3, 0.8 and 1.1. Hence, we suggest further studies to isolate the active ingredients are highly recommended

Evaluation of in vitro antitoxoplasmal activity of some medicinal plants collected from Al Qassim, Saudi Arabia

744-750Toxoplasmosis is a protozoal parasitic infection with serious consequences for immunocompromised people. The commercial pharmaceuticals used for treatment cause adverse effects and cannot provide a 100% cure. We investigated on antitoxoplasmal activities of eleven medicinal plants from seven different families used in the Al Qassim region of Saudi Arabia against infectious diseases. The plants were extracted in methanol. The methanolic extracts were evaluated against Toxoplasma gondii and the Vero cell line using the MTT assay. The results obtained revealed the maximum inhibitory effects of extracts of Citrullus colocynthis, Blepharis ciliaris and Aerva javanica with IC50 values of 27.7, 65.2 and 78 µg/ml, respectively against the parasite. However, at the effective levels of antitoxoplasmal activity extracts, of all the above plant species showed different degrees of cytotoxicity against the Vero cell line with SI values of 1.3, 0.8 and 1.1. Hence, we suggest further studies to isolate the active ingredients are highly recommended

Two Chromatographic Methods for the Determination of Some Antimigraine Drugs

Two stability indicating chromatographic methods were proposed for the determination of almotriptan, eletriptan, and rizatriptan, in presence of their acid degradation products. The first method is a quantitative densitometric thin layer chromatography. The developing systems were; acetonitrile: methanol: dichloromethane: ammonia (10:6:3:1 v/v), ethyl acetate: methanol: ammonia (15:4:1 v/v), and methanol: acetonitrile: ammonia (9:4:1 v/v) for almotriptan, eletriptan and rizatriptan respectively. The TLC plates were scanned at 235 nm. Linear relationships were obtained over concentration ranges (5–50 μg/spot) for almotriptan and rizatriptan, and (5–60 μg/spot) for eletriptan. The second method based on the separation and determination of the studied drugs, using RP-HPLC technique. The separation was achieved on C18 Hypersil column, elution was carried out using phosphate buffer pH 3: methanol: acetonitrile (2: 1:1 v/v) at flow rate 2 mL/min and UV detection at 235 nm. Linear relationships were obtained over concentration ranges (10–200 μg/mL) for almotriptan and eletriptan, and (10–180 μg/mL) for rizatriptan. The chromatographic methods were successfully applied for the determination of each of the studied drugs in pure form, tablet form, and in laboratory prepared mixtures with their acid degradation products

Diffusion controlled corrosion in gas sparged systems

The rate of diffusion - controlled corrosion of the walls of rectangular bubble column and a liquid has been studied with the copper dissolution technique. Variables studied were superficial air velocity, initial height of solution in the column, physical properties of the solution and the presence of suspended solids with different concentrations and different particle size. The rate of diffusion - controlled corrosion in solution free solids was given by the equation J = 0.232 (Fr .Re)-0.22 (L/de)-0.169 while for the presence of suspended solids, the data were correlated by the equation J = 0.171 (Fr .Re)-0.214(L/d p) 0.187 The presence of suspended solids increases the rate of diffusion - controlled corrosion by an amount ranging from 5 to 16 %

Long-Term Survival in Patients with Cancers: A SEER-based analysis

Objectives: Long-term survival is an important endpoint in management of different malignancies which is rarely assessed due to unfeasibility of follow-up for long duration of time. In this study, we explored real-world data on cancer’s long-term survival using historical records from the Surveillance, Epidemiology, and End Results (SEER) Program. Besides reporting the 5-year relative survival, we analyzed the 10- and 20- year survival rates for different types of cancers. Additionally, survival trends as a function of time, age, and tumor type were reviewed and reported. Methods: We used SEER*Stat (version 8.3.6.1) for data acquisition from the SEER 9 Regs (Nov 2019 Submission) database. Data of patients diagnosed with cancer between 1975 and 2014 were retrieved and included in the analysis. Results: For patients diagnosed with any malignant disease (n = 4,412,024), there was a significant increase in median overall survival over time (p<0.001). The 20-, 10-, and 5-year survival rates were higher in solid tumors compared to hematological malignancies (50.8% vs. 38%, 57% vs. 47.4%, and 62.2% vs. 57.4%, respectively). The highest 20-year relative survival rates were observed in thyroid cancer (95.2%), germ cell and trophoblastic neoplasms (90.3%), melanoma (86.8%), Wilms’ tumor (86.2%), and prostate cancer (83.5%). Conclusions: Long-term follow-up data were suggestive of high 20-year relative survival rates for most tumor types. Relative survival showed an improving trend over time especially in solid tumors. Keywords: Survival; Neoplasms; SEER Program; Prognosis; United States