384 research outputs found

    Interactions of dietary selenium and fat on fatty acid compositions of rainbow trout (Oncorhynchus mykiss) tissues

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    The main objective of this study was to determine the interactive effects of dietary selenium and fat on fatty acid compositions of rainbow trout tissues. We formulated six experimental diets by addition of two fat levels (15 and 30%) and three selenium levels (0.1, 0.15 and 0.2mg/kg) to a basal diet, according to a 3x2 factorial design. Juvenile rainbow trout with initial weights of 6.99g were assigned to 18 tanks with 300L capacity each containing 25 fish, with three replicates for each diet. The result showed that unsaturated fatty acid and tissue oxidation rate increased with an increase in fat content of the diets. Addition of dietary selenium increased enzyme of Glutathione (GSH-Px) activity and at high-fat diet (30% fat), selenium addition improved polyunsaturated fatty acid compositions by depression of oxidation rate. However, inclusion of high dose of selenium (0.2mg/kg) had a negative impact on the Arachidonic and Eicosapentaenoic acids. In conclusion, dietary selenium supplementation can preserve fatty acid quality by controlling fatty acid oxidation at high-fat diet. The results obtained from the current study suggest that rainbow trout at high-fat diet requires 0.15mg/kg selenium to reduce oxidation level

    An Empirical Ultra Wideband Channel Model for Indoor Laboratory Environments

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    Channel measurement and modeling is an important issue when designing ultra wideband (UWB) communication systems. In this paper, the results of some UWB time-domain propagation measurements performed in modern laboratory (Lab) environments are presented. The Labs are equipped with many electronic and measurement devices which make them different from other indoor locations like office and residential environments. The measurements have been performed for both line of sight (LOS) and non-LOS (NLOS) scenarios. The measurement results are used to investigate large-scale channel characteristics and temporal dispersion parameters. The clustering Saleh- Valenzuela (S-V) channel impulse response (CIR) parameters are investigated based on the measurement data. The small-scale amplitude fading statistics are also studied in the environment. Then, an empirical model is presented for UWB signal transmission in the Lab environment based on the obtained results

    Effect of different Alphamune levels in artificial diet on growth parameters, digestibility and enzyme activity of rainbow trout, Oncorhynchus mykiss (Walbaum 1792)

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    This study was conducted to evaluate the effects of Alphamune, a mixed prebiotic composed of mannan-oligosaccharide and β-glucans, on the growth performance, digestibility and enzyme activity of rainbow trout, Oncorhynchus mykiss. A basal diet was formulated using common feed ingredients supplemented with Alphamune at 0, 0.5, 1, 2, and 4 g.kg^-1 leading to five experimental diets. Obtained results showed that inclusion of dietary Alphamune significantly increased the final weight and weight gain (p0.05). Also apparent digestibility coefficient (ADC) was not affected by dietary addition of the prebiotic (p>0.05). Our results indicated that amlayse and lipase activities were not significantly influenced by administration of different doses of Alphamune. The result also showed that trypsin activity was gradually increased with increasing of the probiotic level (p>0.05). In conclusion, inclusion of the prebiotic Alphamune can improve the nutrient efficiency and growth performance of rainbow trout confirming the positive effect of a mixture of prebiotics on fish

    Febrile Convulsions: The Role Played by Paraclinical Evaluation

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    ObjectiveThis survey evaluates the necessity of biochemical and imaging findings for patients with initial diagnosis of febrile convulsion, and also aims at determining the degree to which results of paraclinical examinations delineate management of patients.Materials & MethodsData of 302 patients referred to Mofid Children Hospital during two years (2005-2006) for febrile convulsions (FC), were collected in formatted questionnaires and analyzed.ResultsAbnormal lumbar punctures were reported in 9 patients, 3 of which had bacterial meningitis (1%). Biochemical tests including sodium, potassium, calcium, urea and glucose measurement, were performed for 289 (of 302 patients); of these 289, 9 cases were reported with hyponatremia, one casewith hypokalemia and one case with hypocalcemia. Brain CT was done in 51 cases and the results were abnormal in 4%, included a patient with status epilepticus.ConclusionConsidering the results obtained from data, we suggest that most of the paraclinical examinations are not needed for Febrile Convulsions (FC), for simple FC, in particular.

    Comparative Effects of Diazepam Infusion and Divided Doses of Diazepam on the Treatment of Absence Status Epilepticus

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    ObjectiveAbsence status epilepticus (ASE) is a common form of nonconvulsive status epilepcticus. It is  characterized by loss of consciousness with spike and wave discharges in EEG simultaneously. The most effective treatment of ASE is diazepam, either infusion or in divided doses; the former is more expensive since patients must be admitted in an Intensive Care Unit. The aim of this study was to evaluate and compare the efficacy of diazepam infusion and parenteral diazepam in divided doses in the treatment of ASE.Materials & MethodsThis randomized controlled clinical trial, enrolled 20 patients with absence status epilepticus. Diagnosis was made based on the clinical manifestations and electroencephalogram (EEG). Prior to treatment, all patients underwent EEG and imaging. Patients were randomized to receive 0.2 mg/kg/h diazepam infusion or 0.2 mg/kg in six daily doses. Clinical and EEG improvements were considered to be optimal responses.ResultsOf the 20 patients studied, 13 (65%) were boys and the remaining 7(35%) were girls. There were no differences between the two groups regarding age and sex (non-significant). Following treatments after 48 hours, 1 week and 1 month respectively, clinical improvement in previous problems (loss of consciousness, ataxia, behavior and speech problems) and EEGs was similar in both groups (p=1). There were controlled seizures in 18 (90%), abnormal CT scans in 5 (25%), abnormal EEGs after treatments in 6 (30%) cases; however no significant differences were seen between the two groups.ConclusionThis study demonstrates that there are no significant differences between treatments of ASE with diazepam infusion and parenteral diazepam in divided doses. Treatment of ASE, with divided doses of diazepam is easier, less expensive and patients do not require to be hospitalized in an Intensive Care unit

    Induction of cytochrome P4501A1 by beta-naphtho flavone and determination of enzyme properties in Huso huso

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    Cytochrome P4501 AI is a major isoenzyme in fish monooxygenase system which is induced by polycyclic aromatic hydrocarbons (PAHs) compounds. In this research, the inducing effect of p-naphtoflavone and its catalytic properties was studied in Huso huso liver. Fish were given ip injection of p-naphthoflavone at three different doses. The enzyme activity was measured with de-ethylation of ethoxyresorufin reaction (EROD) by flourometery method and relative amount of induced proteins were determined using polyacrylamid del electrophoresis (SDS-PAGE). The results showed that EROD activity in the microsomal fraction of the treated fish was 15-26 folds that of the control group. Optimum activity of this enzyme was observed at 20-25 degrees centivade. The maximum enzyme activity was seen in the precence of 180 micrograms of microsomai protein and 1.5311M of 7-ethoxyresorufin. SDS-PAGE of microsomal protein pattern in the treated fish revealed a protein with molecular mass 58+1 KDa translating to cytochrome P4501A. We conclude that the p-naphtoflovone in fish liver can induce cytochrome P4501A gene and increase its biosenthysis leading to raised enzyme activity in EROD reaction

    Linear-nonlinear stiffness responses of carbon fiber-reinforced polymer composite materials and structures: a numerical study

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    The stiffness response or load-deformation/displacement behavior is the most important mechanical behavior that frequently being utilized for validation of the mathematical-physical models representing the mechanical behavior of solid objects in numerical method, compared to actual experimental data. This numerical study aims to investigate the linear-nonlinear stiffness behavior of carbon fiber-reinforced polymer (CFRP) composites at material and structural levels, and its dependency to the sets of individual/group elastic and damage model parameters. In this regard, a validated constitutive damage model, elastic-damage properties as reference data, and simulation process, that account for elastic, yielding, and damage evolution, are considered in the finite element model development process. The linear-nonlinear stiffness responses of four cases are examined, including a unidirectional CFRP composite laminate (material level) under tensile load, and also three multidirectional composite structures under flexural loads. The result indicated a direct dependency of the stiffness response at the material level to the elastic properties. However, the stiffness behavior of the composite structures depends both on the structural configuration, geometry, lay-ups as well as the mechanical properties of the CFRP composite. The value of maximum reaction force and displacement of the composite structures, as well as the nonlinear response of the structures are highly dependent not only to the mechanical properties, but also to the geometry and the configuration of the structures

    Immune system challenge in a host-parasitoid-pathogen system: interaction between Cotesia plutellae (Hym.: Braconidae) and Bacillus thuringiensis influences parasitism and phenoloxidase cascade of Plutella xylostella (Lep.: Plutellidae)

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    We investigated the effects of interaction between Cotesia plutellae (Kurdjumov) and Bacillus thuringiensis Berliner on parasitism and an immune effector (phenoloxidase activity) of a Bt-susceptible and a Bt-resistant population of Plutella xylostella (Linnaeus) in laboratory. Parasitism success of C. plutellae varied depending on the use of B. thuringiensis or its toxin, and the timing of application. Percentage parasitism was significantly greater on Cry1Ac-treated hosts than B. thuringiensis var. kurstaki-treated hosts (the susceptible population), and greater when hosts were treated with B. thuringiensis var. kurstaki before parasitism compared to that after parasitism (the resistant population). Specific phenoloxidase activity was significantly reduced in Cry1Ac-treated or parasitized hosts, but combined effect of the toxin and the parasitoid caused a greater reduction in phenoloxidase activity. The lower phenoloxidase activity in unparasitized resistant population of P. xylostella compared with the susceptible one is likely to be due to fitness costs, manifesting a possible trade-off between pathogen resistance and parasitoid resistance. However, C. plutellae overwhelmingly suppressed phenoloxidase activity of both the susceptible and resistant populations of P. xylostella. We found that the interaction between B. thuringiensis and C. plutellae was synergistic, which is promising for integration of the pathogen and the parasitoid in management of P. xylostella populations

    Growth pattern and body weight-length relationship of narrow clawed crayfish, Astacus leptoductylus

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    In order to investigation of growth pattern and body weight-length relationship of narrow clawed crayfish, Astacus leptodactylus in different stages of its life, approximately 10000 newborn crayfish were released in earthen pond. This pond had the similar condition to their habitat. Sampling was done during four stages of their life, under 2 months and 4, 6, 15 months among crayfish population. After separating the samples as sexes, some indices such as total length, total weight, claw weight and abdomen meat weight were measured. The results of this study showed, there is a power relation between length and weight indices in different parts of crayfish body for male and female. The growth pattern in experimental crayfish was isometric while the claw growth pattern was observed as allometric in male according to this relationships and regressions analysis
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