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Heat Transfer Analysis for Peristaltic Mechanism in Variable Viscosity Fluid
No full textAn analysis is carried out for a peristaltic flow of a third-order fluid with heat transfer and variable viscosity when no-slip condition does not hold. Perturbation solution is discussed and a comparative study between the cases of constant and variable viscosities is presented and analyzedThe ADS is Operated by the Smithsonian Astrophysical Observatory under NASA Grant NNX09AB39
Impaired plasma phospholipids and relative amounts of essential polyunsaturated fatty acids in autistic patients from Saudi Arabia.
No full textBACKGROUNDS:
Autism is a developmental disorder characterized by social and emotional deficits, language impairments and stereotyped behaviors that manifest in early postnatal life. This study aims to compare the relative concentrations of essential fatty acids (Linoleic and α- linolenic), their long chain polyunsaturated fatty acids and phospholipids in plasma of autistic patients from Saudi Arabia with age-matching controls.
METHODS:
25 autistic children aged 3-15 years and 16 healthy children as control group were included in this study. Relative concentration of essential fatty acids/long chain polyunsaturated fatty acids and omega-3/omega-6 fatty acid series together with phosphatidylethanolamine, phosphatidylserine and phosphatidylcholine were measured in plasma of both groups.
RESULTS:
Remarkable alteration of essential fatty acids/long chain polyunsaturated fatty acids, omeg-3/omega-6 and significant lower levels of phospholipids were reported. Reciever Operating characteristics (ROC) analysis of the measured parameters revealed a satisfactory level of sensitivity and specificity.
CONCLUSION:
Essential fatty acids/long chain polyunsaturated fatty acids and omeg-3/omega-6 ratios, phosphatidylethanolamine, phosphatidylserine and phosphatidylcholine could be used as potential biomarkers that point to specific mechanisms in the development of autism and may help tailor treatment or prevention strategies.Autism Research and Treatment Cente
Assessment of antifungal activity of Rumex vesicarius L. and Ziziphus spina-christi (L.) Willd. extracts against two phytopathogenic fungi
No full textThe preliminary phytochemical screening of extracts of Rumex vesicarius L. and Ziziphus spina-christi (L.) Willd. showed the presence of compounds that are biologically active against the two root rot pathogens Drechslera biseptata and Fusarium solani in vitro. The relative efficacy of this action, however, differed according to the extracted plant, solvent used, extract concentration, the target fungus and phase of growth. Ethanolic extract ranked first, followed by the remaining aqueous layer fraction. Eight flavonoid subfractions (rutin, quercetin, myricetin, apigenin, quercetin-3-O-galactoside, luteolin, kaempherol and kaempherol-3-O-robinoside) and six flavonoid subfractions (apigenin-7-O-glucoide, quercitrin, quercetin, isovitexin, rutin and quercetin-3-O lucoside-7-O-rhamnoside) were isolated from the remaining aqueous layer fraction of R. vesicarius and Z. spina-christi, respectively. Generally, spore production and germination as well as cellulolytic and pectolytic activity of F. solani were affected by plant extracts more than that of D. biseptata. F. solani failed completely to produce spores when treated with ethanolic extract of Z. spina-christi at the concentration of 20%. However, growth of D. biseptata was more sensitive to plant extracts than that of F. solani. Maximum activity of plant extracts was observed against spore production. It was evident that plant extracts could provide potential source of antifungal compoundsKing Saud universit
Optimization of epidemiological conditions to enhance the mycoherbicidal efficacy of Alternaria alternata against Chenopodium album
No full textA new foliage disease was found on Chenopodium album L. (family chenopodiaceae) in Punjab, Pakistan. Alternaria alternata (Fr.) Keissler was identified and confirmed as the causal agent. The present study aimed to optimize environmental condition that could enhance mycoherbicidal potential of A. alternata against C. album. In growth room trials, the effects of various inoculum concentrations of A. alternata (105, 107 and 109 conidia ml-1) on disease development was studied at different growth stages of the host plant (5 - 10, 10 - 15 and 20 - 25 leaf/flowering stage) at various dew period (100% humidity for 12, 18 and 24 h) and temperature (20, 25 and 30°C) regimes. To enhance the mycoherbicidal potential of the pathogens, different formulations; 1 and 2% gelatin, 1 and 2% carboxymethylcellulose (CMC), 1:1 gelatin and CMC, 10 and 20% canola oil emulsion were used. The pathogenicity of A. alternata increased with increasing spore concentration and length of dew period. A spore concentration of 109 conidia ml-1 in 20% canola oil emulsion with 24 h dew period and at temperature 25 and 30°C caused 100% mortality of C. album plants at 5 - 10 and 10 - 15 leaf stages and resulted in maximum reduction in biomass of the target weed. The present study concludes that under a certain set of conditions, A. alternata can completely control C. albumAcademic Journal
Effect of Riyadh cement industry pollutions on some physiological and morphological factors of Datura innoxia Mill.
No full textAbstract Cement factory emissions into air cause serious air pollution and affect the plant and animal
life in the environment. Herein, we report the effects of cement industry emissions (O3, SO2 and
NO2) in air, as pollutants, at Riyadh City on Datura innoxia Mill. plant. Morphological characters
including plant height, leaves area and number, fresh and dry weight of shoot and root systems of
D. innoxia showed a significant reduction from their normal control plants as a response to exposure
to pollutant emissions. Chlorophyll and carotenoid contents recorded reductions in values
compared to control plant, and the lowest values of chlorophyll A, B, total chlorophyll, carotenoids
and total pigments were 0.431, 0.169, 0.60, 0.343 and 0.943 mg/g respectively at a distance of 1–5 m
from the cement factory in fruiting stage. These changes in values may be attributed to a probable
deceleration of the biosynthetic process rather than degradation of pigments. Further D. innoxia
showed a significant (P <0.01) reduction in non-reducing and total sugars, protein and total lipid
contents compared with the control plant. The root system recorded the lowest values of reducing
sugars (0.350 mg/g f. wt.), non-reducing sugars (0.116 mg/g f. wt.), total sugars (0.466 mg/g f. wt.),
protein content (0.931 mg/g f. wt.) and total lipids content (0.669 mg/g f. wt.) in fruiting stage at a
distance of 1–5 m from the cement factory. The peroxidase activity of shoot and root systems of the
studied plant was also significantly higher than those of control plant. Thus a highest value of
(29.616 units/g f. wt.) peroxidase activity was recorded in vegetative stage of shoot system at a di
Influence of backpack weight on school girls' balance and musculoskeletal pain
No full textBACKGROUND: School age children are in critical stage of their development. They might be carrying heavy backpacks and they are unable to voice their concern and problems. That leaves them more exposed to postural deviations, musculoskeletal problems and balance instability. OBJECTIVES: The aims of this study were to measure the backpack weight carried by Saudi school girls, to determine the influences of backpack loads on ear and shoulder posture level. determine the different influences of backpack weight on musculoskeletal pain and investigate the effectiveness of daily load of backpack on dynamic balance and postural stability. METHODS: A sample of 175 Saudi school girls age between 12-15 years recruited from random five public schools in Riyadh city. A questionnaire was used to evaluate musculoskeletal problems. Postural mirror was used to measure the level of the ears and the level of the shoulders. The balance master machine was used to measure the dynamic balance in three tests (limits of stability, Step /quick turn, Step up/over). RESULTS: The questionnaire showed significant number of girls complain of shoulder (43.43%), neck (32.6%) and back pain (40%), and majority of girls (87.4%) carried their backpack using a single strap backpack, who reported that their
backpacks were heavy. The results revealed that most of the students spend more than 4 hours watching television and using computer. There is a significant difference in shoulder level (P<0.000). A significant difference in the balance master variables with carrying and without backpack was reported. CONCLUSION: The results of this study concluded that carrying backpack that is 10.08% of body weight caused girl’s complain of shoulder, neck and back pain, induced postural changes and affected their dynamic balance. The backpack weight percentile is recommended to be reduced to 5% body weight.
KEY WORDS: Backpack, Musculoskeletal problems, Posture, Dynamic balance
Development and evaluation of oral disintegrating tablets using different formulations and process variables
No full textMastersOrally Disintegrating Tablets (ODTs) have become a very popular dosage form as they disintegrate rapidly (< one minute) in the mouth and don’t require water for administration. This is due to the increased patient compliance, pleasant mouth feel, ease of administration & swallowing and rapid disintegration and dissolution. There are three main manufacturing methods used for the production of ODTs, namely, freeze drying, molding and compression method. Also, different technologies are routinely used for manufacturing ODTs as Orasolv®, Durasolv®, WOWTAB®,
Flashtab®, Zydis®, Quicksolv® and Lyoc® technologies. Some methods of manufacturing ODTs are complex, require multiple processes and don’t provide all ODTs ideal properties. For example, freeze drying and molding provide very light and porous products which disintegrate very rapidly, but they are expensive and produce fragile products. On the other hand, compression method is the easiest and cost effective method for the production of ODTs. It has several advantages as simple equipment, commonly available excipients, high doses can be used and limited number of manufacturing steps.
The specific aim of this study was to develop a simple and inexpensive method of manufacturing ODTs and studying the effect of different formulation and process variables. Dextromethorphan hydrobromide (DM), a sparingly water soluble drug used in treatment of cough, was chosen as a model drug. ODTs formulations of DM have the advantages of both solid and liquid dosage forms and are useful for immediate relief of cough with improved patient compliance and to help patients of all age groups who have difficulty in swallowing.
Orally disintegrating tablets containing 15 mg of DM were manufactured using direct compression method. Experiments were
performed according full factorial designs to evaluate effects of formulation parameters like type & concentration of diluents, concentration of disintegrating agent and their interactions on dextromethorphan hydrobromide ODTs properties. Dextrates, microcrystalline cellulose and spray dried sorbitol were used as diluents of different properties, in addition to croscarmellose sodium (CCS), which was used as a superdisintegrant.
It was found that microcrystalline cellulose at 30 % level in combination with croscarmellose sodium at 3 % level produced ODTs with the lowest disintegration time (12.5 sec. ± 1.22), low T50 (0.8 min.), the time required for 50 % of loaded drug to be released, and a high hardness (4.92 kp ± 0.28). Additionally, ODTs consisting of 30.6% of dextrates and 4.2% of croscarmellose sodium produced tablets with low disintegration time (21.5 ±1.37 sec), low T50 (0.87 min) and high hardness (3.99 ± 0.29). Moreover, sorbitol at 17.5 % levels in combination with croscarmellose sodium at 4.89 % levels produced ODTs having a low disintegration time (27.5 ± 1.6 sec), a lower T50 (1.5 min.) and hard tablets (4.36 ± 0.25 kp).
Effect of different formulations (disintegrating agents and lubricants) and process variables (compression force) on the
optimized formulation were evaluated. Crospovidone (CP) and sodium starch glycolate (SSG) were used as superdisintegrants at the same concentration of optimized croscarmellose concentration. Sodium stearyl fumarate, talc, stearic acid, sodium benzoate and glycerol dibehenate were used as lubricants at the same concentration of magnesium stearate (1%). In addition, different compression forces (2-7 kN) were used as a process variable.
ODTs composed of microcrystalline cellulose at 30 % level in combination with croscarmellose sodium at 3 % level was chosen as optimized formula, as it showed the lowest disintegration time, low T50 and hard tablets amongst other tested ODTs formulations. Disintegration time of optimized tablets was not significantly affected by replacing CCS by crospovidone, but it was significantly (p-value < 0.05) increased from 12.5 sec. ± 1.22 to 15.5 ± 0.56 sec in tablets prepared by sodium starch glycolate. Furthermore, hardness of the manufactured tablets was not significantly affected by the use of crospovidone and sodium starch glycolate instead of CCS. Disintegration time and hardness of tablets was not significantly affected by the change of lubricant. However, dissolution rate was affected by changing lubricant type and it can be arranged as follows: glycerol dibehenate > Mg stearate >
sodium stearyl fumarate. Disintegration time and hardness were significantly (p-value < 0.05) increased by increasing compression force from 2 kN to 7 kN.
The optimized formula was compared to a ready ODTs system (PharmburstTM) and to marketed conventional tablet product (Tussilar®). The effect of storage under accelerated conditions (Temp: 40 ± 2 °C and relative humidity: 75 ± 5 %) and long term conditions (Temp: 25 ± 2 °C and relative humidity: 60 ± 5 %) were carried out for three months for some selected ODTs formulations.
The obtained results revealed that disintegration time of the optimized ODTs formula (12.5 sec. ± 1.22 sec) was significantly (p-value < 0.05) lower than disintegration time of the Pharmburst TM formula (14.17 sec. ± 0.75 sec). However, PharmburstTM based formula gave a higher dissolution rate than the optimized one. On the other hand, hardness of both two formulas wasn’t significantly different. Also, it was found that optimized formula had significantly (p-value < 0.05) lower hardness and disintegration time with a higher dissolution rate than Tussilar® as well.
Disintegration time of optimized formula was observed to be not significantly changed upon storage under long term and accelerated storage conditions up to three months. However,
hardness was significantly (p-value < 0.05) decreased from 4.92 ± 0.28 kp to 2.37 ± 0.54 kp under accelerated conditions and was stable under long term conditions for three months. ODTs formulations composed of dextrates and sorbitol showed softening when stored under accelerated conditions. However, dextrates based formula was stable when stored under long term conditions. Furthermore, sorbitol based formula was significantly affected (p-value < 0.05) in regard to hardness (from 5.55 ± 0.32 kp to 2.87 kp) and disintegration time (from 49.33 ± 5.85 sec to 15.67 ± 1.96 sec). Additionally, the formula containing mannitol was stable only when stored in long term conditions but a significant increase (p value < 0.05) in hardness from 3.91 ± 0.32 kp to 5.58 ± 0.73 kp occurred when they were stored in accelerated conditions.
Finally, it was concluded that dextromethorphan hydrobromide oral disintegrating tablets were developed using microcrystalline cellulose and croscarmellose sodium. These tablets provided low disintegration time, T50 and high hardness that are acceptable for ODTs
Enhanced Multi-Hop Data Harvesting Protocol Implementation in Vehicular Sensor Networks
No full textVehicular sensor networks are emerging paradigm as intelligent transportation system to make roads safer
and less congested. Consequently, efforts are directed towards developing safety systems that help reduce
the severity of crashes, or prevent vehicles from colliding with one another, and to save time for people
when they are transported between places. Currently, existing network protocols for general sensor
networks pose problems when used in VSN applications. Even the majority of research based on VSN
network protocols has some problems, as they limit their data harvesting schemes to only single-hop or
short distance transmissions, or use high-cost relay stations to support multi-hop cases. As a result, these
works cannot completely solve some critical issues in VSN, such as data transmission delay, packet
overhead, and network connectivity.
Objectives:
• To design a feasible, efficient and robust intelligent vehicular system framework to monitor road
traffic and provide desired and reliable information for users, particularly for drivers in automobiles.
Equipment:
• C++ and MATLAB.
Contribution:
The basic idea behind intelligent transportation system is how to deploy vehicular sensor network that
have many characteristic such as high computation power, enough storage space and mobile sensor node
in order to design an effective and efficient architecture for data collection and data exchange. In this
thesis, we will introduce an intelligent transportation system with new network paradigm to collect
important information from the road environment based on the vehicular sensor network (VSN). Data
aggregation provides the drivers by valuable information in order to make the road safer and less
congested. Our system framework consists of active vehicular sensor node, passive vehicular sensor node
and sink node distributed according to the road segmentation. Sink nodes consists of collecting data from
active vehicular sensor nodes passing by, while active vehicular sensor nodes collect data from passive
vehicular sensor nodes in their segment using multihop data harvesting. Our scheme aims to reduce
broadcast storm and avoid collision
Toxoplasma gondii Strategy for Intracellular Survival: Is it Still Enigmatic?
No full textAbstract: Toxoplasma gondii has been considered as one of the most successful models for intracellular parasitism. Throughout the last two decades, considerable progress has been made to clarify the obscurity of both pathogenicity and long-lasting chronicity of toxoplasmosis. The recent integration of the many sources of genomic, proteomic and metabolomic data has allowed good clarification of the molecular details of the parasite-dependent effects for Toxoplasma-infected cells. Mechanisms of host-cell invasion, intracellular survival, stage-conversion of the slow-growing bradyzoite within long-lasting tissue cysts to a rapidly replicating highly pathogenic tachyzoite and vice versa, structure and composition of the apical organelles, subversion of inflammatory host response by the parasite, interference with effector functions of immune cells, evasion of host immune defenses, modulation of host cell apoptosis and the recent achievements in the use of lipid synthetic pathways by the parasite etc., all have been recently highlighted but still in need for further elucidation. This review offers a brief declaration of the progress that has been made to understand the curious intimate relationship between Toxoplasma gondii and its host cell.The Deanship of Scientific Research at king Saud Universit
ترميم احد الظواهر المعمارية بحفرية قرح "المابيات"،العلا، المملكة العربية السعودية : دراسة ميدانية تطبيقية
No full textيتناول هذا البحث أسلوب ترميم وصيانة احد الظواهر المعمارية بحفرية قرح "المابيات"،العلا، المملكة العربية السعودية : دراسة ميدانية تطبيقية ، طرق فحص وتحليل المواد الأثرية، تشخيص الحالة، خطة العلاج والصيان