Gonad Maturation of Angle Fish (Pterophyllum Scallare) Induced by Laser Puncture Exposure at Different TIME Duration

A research was conducted from January-February 2016 at the Fish Hatchery and Breeding Laboratory, Faculty of Fisheries and Marine Science, University of Riau Pekanbaru. The purpose of the research was to evaluate the duration of laser puncture exposure on gonad maturation of angle fish (Pterophyllum scallare). Completely randomized design was used to analyze the gonad maturation at the different duration of laser puncture exposure (0, 15, 20, and 25) seconds. The shooting was done twice a week for 4 weeks. The brood fish were reared in 54 L aquarium tank (60x30x35 cm) and fed on 38% protein pellet plus 57% protein tubifex worm.The results of research showed that there was an effect of laser puncture exposure duration, on gonad maturation of angle fish (Pterophyllum scallare). The best duration of laser puncture to stimulate gonad maturation was 20 second. At the duration the maturation was reached in 35 days with gonado somatic indeks 6,3 %, fecundity 908 eggs, and eggs diameter 1.5 mm. The temperature range from 26-27 oC, pH 5-6, and DO 5,7-6,8 ppm

The level of IL-1?, IL-10 and IL-17A in Alzheimer's disease patients: Comparative study

The objective of this study is to evaluate the level of cytokines IL-1?, IL-10 and IL-17A in the serum of patients with Alzheimer's disease (AD), vascular dementia (VD) and down syndrome (DS). The results showed that Serum level of IL-1? was significantly increased in AD patients (3.79 ± 0.26 pg/ml) as compared with DS patients (2.78 ± 0.39 pg/ml) or controls (2.78 ± 0.22 pg/ml), while no significant difference was observed between AD and VD (3.25 ± 0.20 pg/ml) patients or between VD patients, DS patients and controls. The serum level of IL-10 was approximated in VD and DS patients and controls (3.39 ± 0.24, 2.77 ± 0.39 and 3.41 ± 0.35 pg/ml, respectively), but was significantly (P ? 0.05) increased in AD patients (5.73 ± 0.55 pg/ml) as compared to these groups. The serum level IL-17A was significantly increased in AD and VD patients (6.28 ± 0.35 and 5.32 ± 0.42 pg/ml, respectively) as compared with DS patients (3.75 ± 0.40 pg/ml) or controls (4.05 ± 0.28 pg/ml).IL-10 is important to diffrentiation between AD and VD

Properties enhancement of oil palm plywood through veneer pretreatment with low molecular weight phenol-formaldehyde resin

One of the problems dealing with oil palm stem (OPS) plywood is the high veneer surface roughness that results in high resin consumption during the plywood manufacturing. In this study, evaluation was done on the effects of pretreatment of OPS veneers with phenol-formaldehyde resin on the bond integrity and bending strength of OPS plywood. OPS veneers were soaked in low molecular weight phenol-formaldehyde resin (LMW PF) for 20 seconds to obtain certain percentage of resin weight gain. OPS plywoods were produced using two types of lay-ups (100% outer veneer type and 100% inner veneer type) and two urea-formaldehyde (UF) adhesive spread amounts (200 g/m2 and 250 g/m2). The results show that pretreating the veneer with LMW PF could reduce the penetration of the adhesive into the fibres during gluing step. UF adhesive spread amount of 200 g/m2 is sufficient to produce good quality OPS plywood. The technique used in this study was able to enhance the mechanical properties of OPS plywood as well as reduce the amount of resin consumption

Development of a mathematical tool to predict engine in-cylinder friction

A better fuel-efficient automotive engine is more sought-after to promote greener environment in the era of global warming. One of the factors to cause the increase of fuel consumption in vehicles is the frictional loss within an internal combustion engine. In this study, the focus is to determine the tribological behaviour between the piston top compression ring and the engine cylinder liner for a full engine cycle. Mathematical models are derived from a 1-D Reynolds equation, assuming Half-Sommerfeld and Reynolds boundary conditions. Greenwood and Tripp rough surface contact model is applied to predict frictional properties along the ring-liner contact, considering viscous and boundary friction. It is found that the Half-Sommerfeld boundary condition predicts minimum lubricant film thickness that correlates well with literature data. However, the friction force predicted by the Reynolds boundary condition along dead centres correlates better with literature data. With friction along the cylinder liner dead centres being very significant, it is, therefore, suggested that the Reynolds boundary condition be the better mathematical model in studying the piston ring-liner tribological conjunction

Predictive tool for frictional performance of piston ring-pack/liner conjunction

A substantial portion of engine frictional losses come from piston-ring assembly. However, accurately measuring in-cylinder frictional losses under actual engine operation remains a challenge to the automotive industry, especially during design stages of engines. Hence, the study proposes a simplistic mathematical tool to simulate the effect of different piston ring profiles towards engine in-cylinder friction. The models are derived from Reynolds equation to determine contact pressure generated by the lubricant film formed between the ring and the liner. Friction generated by the ring pack is then computed using Greenwood and Williamson's rough surface contact model. It is found that friction from the top compression ring is the largest, followed by the second compression ring and the oil control ring (single rail), with total friction of 301.3 N. On top of this, emphasis should also be placed on the top compression ring because of its direct exposure towards the combustion chamber in the engine. The predicted film thickness and friction force also showed correlation to other models reported in literature. Hence, the proposed predictive tool prepares for a simple yet robust platform in predicting frictional losses of piston ring-pack/liner conjunction, allowing for improved fundamental understanding of internal combustion engine in-cylinder lubrication

Competitive molecular interaction between zinc dialkydithiophosphate (ZDDP) and methyl oleate along boundary lubrication regime

Fatty acid methyl ester (FAME) possesses good lubricity properties, prompting numerous research work to explore their potential as lubricant additives. However, fully formulated lubricants consist of additive packages, which includes essential anti-wear agents, such as zinc dialkyldithiophosphate (ZDDP). Adding FAME into a lubricant could lead to adverse tribological effects if the competitive molecular interaction between different additives are not well understood. Therefore, the present study determines the tribological impact of molecular interaction between ZDDP and methyl oleate along boundary lubrication regime. Lateral force microscopy, coupled with fluid imaging approach, is adopted, allowing for the analysis to focus on asperity level interaction. A silicon nitride tip is used to slide against a mirror-polished steel substrate while being fully submerged in the tested fluids. The tested fluids are mixtures of ZDDP and methyl oleate, blended at different volumetric percentages. It is observed that the lowest friction force is measured for ZDDP-methyl oleate mixture containing 70-vol% of methyl oleate. Interestingly, the friction force measured for such mixture is found to be lower than that of neat methyl oleate. This finding indicates that an optimum blending ratio between FAME and ZDDP is essential in achieving better boundary lubrication performance for tribological conjunctions

Antibiotics Resistance of Vibrio spp. Isolated from Diseased Seabass and Tilapia in Cage Culture

Vibriosis has become one of the most important bacterial diseases in marine cultured organisms in recent years. This study was focusing on isolation and identification of Vibrio spp. isolated from diseased seabass (Lates calcarifer), tilapia (Oreochromis niloticus) and seawater from Sri Tujuh lagoon in East Coast of Malaysia; also determination of antibiotic resistance patterns among Vibrio spp. Vibrio species isolated from diseased seabass in Pantai Sri Tujuh, Tumpat, Kelantan were screened for their antibiotic sensitivity patterns by Kirby-Bauer method. A total of 47 isolates belonging to three different species were identified which are V. parahaemolyticus, V. vulnificus, and V. alginolyticus. In this study, high incidence of erythromycin, chloramphenicol and sulfamethoxazole resistance was observed among the Vibrio isolates, whereas all isolates were susceptible to oxytetracycline. Vibrio isolates were 96% resistant to one or more different classes of antibiotic, and 17 different resistance patterns were identified. The MAR index of 0.4 indicating the Vibrio spp. in these farmed fish might have been indiscriminately and continuously exposed to those antibiotics during culturing stages of the fish. This study showed that multidrug-resistant Vibrio spp. were common in diseased seabass and tilapia cultured at Sri Tujuh lagoon. These essential findings suggested involvement of seafood in transmission of these pathogen to human. In addition, oxytetracycline can be used as a treatment to combat vibriosis in diseased seabass and tilapia

Various Factors Affecting Students Performances In A Saudi Medical School

Objective: There are various demographic and educational factors that affect the academic performance of undergraduate medical students. The objective of this study is to identify these factors and correlate them to the GPA of the students. Methods: A cross-sectional study design utilizing grade point averages (GPAs) of two cohorts of students in both levels of the pre-clinical phase. In addition, self-administered questionnaire was used to evaluate the effect of these factors on students with poor and good cumulative GPA. Results: Among the various factors studied, gender, marital status, and the transportation used to reach the faculty significantly affected academic performance of students. Students with a cumulative GPA of 3.0 or greater significantly differed than those with a GPA of less than 3.0 being higher in female students, in married students, and type of transportation used to reach the college. Factors including age, educational factors, and type of transportation used have shown to create a significant difference in GPA between male and females. Conclusion: Factors such as age, gender, marital status, learning resources, study time, and the transportation used have been shown to significantly affect medical student GPA as a whole batch as well as when they are tested for gender

Insomnia in chronic renal patients on dialysis in Saudi Arabia

<p>Abstract</p> <p>Background</p> <p>Studies have shown that insomnia is a common sleep disorder among patients with end-stage renal disease (ESRD). This study aimed to assess the prevalence of insomnia in Saudi patients with ESRD who are on maintenance dialysis.</p> <p>Methods</p> <p>This was an observational cross-sectional study carried out over a period of five months in two hemodialysis centers in Saudi Arabia. To assess the prevalence of insomnia, we used the ICSD-2 definition. We also examined the association between insomnia and other sleep disorders, the underlying causes of renal failure, dialysis duration, dialysis shift, and other demographic data.</p> <p>Results</p> <p>Out of 227 enrolled patients, insomnia was reported by 60.8%. The mean patient age was 55.7 ± 17.2 years; 53.7% were male and 46.3% were female. Insomnia was significantly associated with female gender, afternoon hemodialysis, Restless Legs Syndrome, high risk for obstructive Sleep Apnea Syndrome and excessive daytime sleepiness (<it><b>P-values: </b></it>0.05, 0.01, < 0.0001, < 0.0001, and < 0.0001, respectively). No significant association was found between insomnia and other variables, including BMI, smoking habits, underlying etiology of renal failure, dialysis duration, association with hemoglobin, ferritin, and phosphorus or dialysis adequacy as measured by the Kt/V index.</p> <p>Conclusion</p> <p>Insomnia is common in dialysis patients and was significantly associated with other sleep disorders. Greater attention needs to be given to the care of dialysis patients with regard to the diagnosis and management of insomnia and associated sleep disorders.</p