oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 574 )

2018 ( 1056 )

2017 ( 989 )

2016 ( 1478 )

Custom range...

Search Results: 1 - 10 of 477058 matches for " Mona A. Al-Hashem "
All listed articles are free for downloading (OA Articles)
Page 1 /477058
Display every page Item
Gill Histopathological Effects of PAHs on Adult Pearl Oyster, Pinctada radiata at Al-Khiran Coast in Kuwait  [PDF]
Mona A. Al-Hashem
Journal of Environmental Protection (JEP) , 2017, DOI: 10.4236/jep.2017.82009
Abstract: The hazardous effect of water pollution on the histopathology of gill organ of the pearl oyster, Pinctada radiata was studied with respect to polycyclic aromatic hydrocarbon contamination in Al-Khiran coast at Kuwait. Thirty oyster samples from each site, site one where dead oysters were located, site two which is two kilometers away from site one and the control site which is ten kilometers away from site one were collected from Al-Khiran area where a massive number of dead oysters were reported. The gills of oysters were immediately removed and transferred to Bouin’s solution for fixation and then processed for sectioning, staining and mounting and gill tissues were ready for examination. Histopathological changes in gills of oysters exposed to polycyclic aromatic hydrocarbons in site one and site two included necrosis and edemas of branchial lamellae, complete degeneration of gill filaments, loss of regular shape and haemolysis, and inflammation. Gill tissues of oysters from the control site had normal appearance. The study showed a clear evidence that PAHs caused severe histopathological changes in gills of pearl oyster Pinctada radiata.
Effect of Temperature on the Stiffness of Polyvinyl Chloride and Chlorinated Polyvinyl Chloride Joints Under Bending
Hasan A.S. Al-Hashem,Mushari A.H. Al-Naeem
Journal of Applied Sciences , 2007,
Abstract: The main objective of this study was to determine the effect of temperature on the bending capacity and stiffness of PVC and CPVC cemented socket joints using test specimens as simply supported beams subjected to different bending points. The tests were conducted under six different temperatures (room temperature, 23° C, a control treatment), 50, 60, 70, 80 and 90° C, three bending points and with a deflection of 55 mm using a hydraulic testing machine. The results show that, at room temperature, the mean maximum bending capacity of CPVC joints was close to that of PVC joints. The rate of decrease in the mean maximum bending force of PVC joints was higher than CPVC joints with an increase in temperature. A dramatic decrease in the mean maximum bending force of PVC joints was observed with an increase in temperature from 60-70° C, where the glass transition temperature of PVC material was within the above stated temperature range. At room temperature, the stiffness of PVC joints was slightly more than CPVC joints. But, as the temperature increased, the rate of decrease in the stiffness of PVC joints was more than CPVC joints. The PVC joints lost 80% and the CPVC joints lost 47.6% of its stiffness with an increase in temperature from 23-90° C. The study showed an excellent potential for the selection of optimum temperature for using PVC and CPVC joints under arid environment.
Chronic exposure of rats to native high altitude increases in blood pressure via activation of the renin-angiotensin-aldosterone system
Fahaid H. Al-Hashem,Mahmoud A. Alkhateeb,Abdullah S. Shatoor,Mohammad A. Khalil
Saudi Medical Journal , 2012,
Abstract: Objectives: To study the effect of chronic exposure to native high altitude (HA) on blood pressure, and to investigate the underlying mechanism of action. Methods: This study was carried out between February and April 2011. A total of 20 male rats were divided into 2 groups (n=10 rats). The low altitude (LA) group were rats born and lived in an LA environment at King Saud University, College of Pharmacy, Riyadh, Kingdom of Saudi Arabia (KSA), and the HA group were rats born in the same LA area, then acclimatized to HA area in Physiology Department, King Khalid University, College of Medicine, Abha, KSA for 90 days. At the end of day 90, hematocrit, plasma renin activity, aldosterone, norepinephrine and vasopressin levels were determined in both groups. Invasive arterial blood pressure was also measured, and fractional excretion of sodium (FENa), and potassium (FEK) were calculated. The quantitative real time-polymerase chain reaction of renin was carried out in the kidneys of both rat groups. Results: When compared to LA native rats, HA rats exhibited a significant increase in systolic and diastolic blood pressure with a significant increase in renin plasma activity as well as an increase in the levels of aldosterone, norepinephrine, and vasopressin. Furthermore, HA rats showed a significant increase in renin expression in their kidneys, as well as decreased FENa. Conclusion: Data shows that prolonged exposure to HA results in elevated blood pressure precipitated by the activation of the renin-angiotensin-aldosterone system.
Monitoring Population Abundance of the Sand Lizard Acanthodactylus scutellatus and their Ant Prey in Oil Polluted Soils at Kuwait’s Greater Al-Burgan Oil Field
M. Al-Hashem
Pakistan Journal of Biological Sciences , 2009,
Abstract: Desert ecosystems in Al-Burgan oil fields of Kuwait were contaminated by heavy metals and petroleum hydrocarbons due to oil spill generated by the Gulf War in 1990. Studying sand lizard (Acanthodactylus scutellatus) population and their ant prey in the years 2002 and 2003 to detect the effects of oil pollution is now a focus of study. Polluted sites with apparently different degrees of pollution (namely tar mat, soot and clear sites) were compared with control sites outside this region. Total lizard numbers were recorded by using transect method. Number of ants was recorded by walking the transects and counting ants present. The results showed no difference in lizard population between the different study sites in 2002 and 2003 by applying the transect method. No difference in ant populations between the different study sites in 2002 and 2003. Although, the mean estimated lizard numbers were lower at the tar mat sites, the ant number in this location was greatest, meaning that food availability was highest at these sites. This suggests any reduction in the numbers of lizards is unrelated to low resource availability. The lizard numbers at the tar mat sites could be depressed by some property of the pollutants.
Effects of Oil Pollution on the Population Size of the Desert Lizard Acanthodactylus scutellatus and their Ant Prey at Kuwait’s Al-Burgan Oil Field
M. Al-Hashem
Journal of Biological Sciences , 2009,
Abstract: Desert locations in Al-Burgan oil fields of Kuwait were subjected to oil pollution generated by the Gulf war in 1990. Studying sand lizard (Acanthodactylus scutellatus) population and their ant prey in the years 2002 and 2003 to monitor the effects of oil pollution was thought to be useful in an area damaged by oil spill. Sites with apparently different levels of pollution, namely tar mat, soot and clear sites were compared with control sites outside this area. Live specimens of A. scutellatus were collected by drift fence and pitfall traps and were marked by toe clipping and painting bands before they were released. Ant population was collected by removal methods using vacuum. The mark-recapture Schnabel method of population estimation was used. The results revealed no difference in lizard population sizes between the different study sites in 2002 and 2003. A slight difference was observed in ant population sizes between the sites in 2002 but no difference was detected between the sites in 2003. Although, the mean estimated lizard numbers were lowest at the tar mat sites, the ant number in this location was greatest, meaning that food availability was highest at these sites. This suggests any reduction in the numbers of lizards is unrelated to low resource availability.
Role of vitamins E and C in mitigating hypoxia- and exhaustive exercise-induced aberrant stem cell factor expression and impaired reproductive function in male Wistar rats
Fahaid H. Al-Hashem
Saudi Medical Journal , 2013,
Abstract: Objectives: To evaluate and compare the potential role of vitamins E and C in protecting against acute swimming induced reproductive function damage at different altitudes. Methods: The study was carried between October and November 2010. A total of 36 adult male Wistar rats weighing 250±5 g, and aged 8 weeks were used in this study, which was carried at the Physiology laboratory of King Khalid University in Abha City (high altitude area [HA]), and at the College of Science, King Saud University in Riyadh city (low altitude area [LA]), Kingdom of Saudi Arabia. The rats of each area were divided into 3 groups (n=6 each): control, acute exercise stress, and vitamins E and C pretreated stress. At the end of the study, oxidative stress, reproductive function, histopathology, and expression of stem cell factor (CSF) were examined in all rats. Results: Living under HA conditions decreased expression of SCF, sperm count, and serum levels of reproductive hormones, and significantly increased testicle tissue oxidative stress and lipid peroxidation. Exhaustive exercise-induced stress at both altitudes resulted in similar results with more deteriorating effects in rats of HA compared with LA. Supplementation of vitamins E and C prior to stress induction at both altitudes prevented all these structural and functional aberrations from happening. Conclusion: High altitude or strenuous exercise, or both, may impair male reproductive function, while vitamins E and C in combination potentially mitigate these adverse effects.
Practical Use of Stairs to Assess Fitness, Prescribe and Perform Physical Activity Training  [PDF]
Jasem Ramadan Al Kandari, Salman Mohammad, Ruqayyah Al-Hashem, Girma Telahoun, Mario Barac-Nieto
Health (Health) , 2016, DOI: 10.4236/health.2016.813141
Abstract: Aim: Evaluating climbing stairs for prescription and implementation of physical activity regimes. Methods: Healthy females (F, n = 14), and males (M, n = 15) participated. By climbing 100 steps of stairs with 0.173 m height, Heart rate (HR) and oxygen uptake were measured throughout the floors; Blood pressure (BP) was measured at ground and the 5th floors only. Results: Energy increased from 2 to 7.6 was metabolic equivalents (METs = 3.5 ml O2/min.kg) at 17.3 m elevation in 2 min. at the 5th floor, and percent Heart Rate Reserve (%HRR) was 66.17% in F and 48.7% in M, proportional to their aerobic efforts. Average climbing efficiency was 15.8 ± 2.3% (n = 29). Aerobic capacity estimated dividing the highest work rate (17.3 Kg.m/2min.Kg × 0.00239 = 0.0207 Kcal/min.Kg), by fractional effort (F = 0.6617, M = 0.487) and fractional efficiency (0.158), at 5 Kcal/L O2 was 0.040 in F and 0.054 L O2/Kg.min in M. Minimum training intensity reached at the 3rd floor by F. In M the highest %HRR reached was 48.7% at the 5th floor, insufficient for training. Conclusions: Stairs used for submaximal evaluation of aerobic capacity and for target intensity prescription. Training, levels climbed, repetitions per day (if 5, 100 Kcal per day, ascending) and number of days/week are adjusted. Full regime requires up to 7.6 METs, a total of 532 and 140 MET.min/week ascending and descending, respectively. Intensities >7.6 MET, climbing rate should be >8.65 m/min. Limiting ascent to 1 (3.5 METs) or 2 (5.5 METs) floors or only descents (2 - 3 METs) may be used for unfit subjects. This method is useful for those with no access to sophisticated facilities.
RAFMAN: Lossy Image Compression Algorithm for Improving Image Quality Based on Hybrid Lossless Techniques
Rafeeq Al-Hashem,Ayman Al-Dmour
Information Technology Journal , 2011,
Abstract: Image compression is a key technology in the development of various multimedia and communication applications. In this paper, we have proposed a new algorithm of the image compression using byte compression technique. The encoding processes starts by implementing a modified decimal Run Length Encode (RLE). The RLE counts the occurrences of the pixel values of the original image and stores the occurrences in one byte with the pixels value to merge the two bytes in one byte (value, occurrences). The output from the previous step entered into another compression stage by applying Huffman's code that boosts the compression ratio of the image. To improve quality and compression ratio of the reconstructed image, an adaptive filter is implemented. The results show that the proposed algorithm provides superior performance in terms of compression ratio and exhibiting highest (PSNR) is retained for the image in additional to low Mean Square Error (MSE).
Acute oral administration of Khat (Catha edulis) aqueous extract elevates blood pressure and prolongs QT and QTC intervals in Wistar albino rats
Fahaid H. Al-Hashem,Abdullah S. Shatoor
Saudi Medical Journal , 2012,
Abstract: Objectives: To investigate the effect of Khat (Catha edulis) acute administration on blood pressure (BP) and electrocardiogram (ECG) in vivo. Methods: This study was performed between January and February 2009 at the Physiology Laboratory, Medical College of King Khalid University, Abha, Kingdom of Saudi Arabia. Two groups of Wistar rats (n=10), weighing 190-200 g were divided into control group and Khat treated group. Throughout the study, arterial BP and ECG were recorded for 60 consecutive minutes. The data were collected and analyzed by Power Lab Data Acquisition System every 10 minutes, and were compared within and between the groups. Results: Oral administration of Khat resulted in significant time dependent increases in both systolic and diastolic BP with a maximum increase at minute 60 after extract administration (systolic BP - 34.1%; and diastolic BP - 46.2%). Heart rate was significantly increased at all minutes of the study with a maximum increase occurring at minute 40 (12.8%). There was a significant decrease in PR interval through the experiment, and the maximum decrease was observed at minute 40 (-15.2%). However, QT and QTc started to widen 20 minutes after extract administration with a maximum prolongation in both intervals to occur at minute 40 (QT - 11.6%; QTc - 9.1%). Conclusion: These newly reported changes in the ECG of rats after Khat administration should be a warning regarding the cardiac hazards of Khat chewing.
Effects of Oil Pollution at Kuwait`s Greater Al-Burgan Oil Field on the Timing of Morning Emergence, Basking and Foraging Behaviors by the Sand Lizard Acanthodactylus scutellatus
M. Abdulla Al-Hashem,P.F. Brain,S. Ahmad Omar
Pakistan Journal of Biological Sciences , 2008,
Abstract: An attempt was made to study the effects of oil pollution in a desert location (the Greater Al-Burgan oil fields, an area damaged in the second Gulf War) in Kuwait on the behaviour of the Sand lizard A. scutellatus. Polluted sites with apparently different degrees of contamination (namely tar mat, soot and clear sites) were compared with control areas outside this region. Between 2002 and 2003, ten lizards (5 of each sex) on each polluted and each control site were observed in the field at a time of the year when they were highly active. Air, substrate and burrow temperatures were recorded and lizards were monitored for their morning emergence times, as well as their basking and foraging activities. The present study confirmed that the morning emergence times and the basking behavior varied in sand lizards among the different pollution site categories. Physical changes in the tar mat sites caused the substrate temperatures in these locations to rise more quickly in the morning in response to solar gain than was the case in the other sites. This gives lizards in these locations the opportunity to emerge earlier and to start eating more quickly, giving them an energetic advantage (perhaps, in turn, influencing their rates of growth and fecundity). The clear sites had the next earliest emergence and were the next hottest but it is difficult to account for this in terms of the physical characteristics of this site. The basking times were clearly shorter on the dark soot and tar mat sites that appeared to have higher solar gain than control or clear sites. There did not appear to be any obvious differences in foraging activity of lizards in the different locations. It appears that some aspects of simple behaviour in these lizards provides a reliable, noninvasive indices for assessing oil pollution in desert locations. The precise impact of these changes in these reptiles on their long-term viability needs to be evaluated.
Page 1 /477058
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.