3,801 research outputs found
Improvement of drought tolerance in five different cultivars of Vicia faba with foliar application of ascorbic acid or silicon
Aim of study: To explore the role of ascorbic acid (AsA) or silicon (Si) in improving drought tolerance in five faba bean cultivars under irrigation water deficit (IWD).Area of study: The experimental farm; 30° 36′ N, 32° 16′ E, Egypt.Material and methods: Three drip irrigation regimes (WW, well-watered, 4000 m3 water ha-1; MD, moderate drought, 3000 m3 water ha-1; and SD, severe drought, 2000 m3 water ha-1) were applied to plants, which were sprayed 25, 40, and 55 days after sowing with 1.5 mM AsA or 2.0 mM Si vs distilled water as a control.Main results: Drought negatively affected physiological attributes (photosynthetic pigments, gas exchange parameters, relative water content, membrane stability index, electrolyte leakage (EL), and lipid peroxidation), which restricted plant growth and yields, and stimulated alterations in both enzymatic and non-enzymatic antioxidant activities. However, AsA or Si application mitigated drought effects on physiological attributes, improving growth, yields and water use efficiency by raising antioxidant activities and suppressing lipid peroxidation and EL in stressful cultivars. The mitigating effects of AsA and Si were more pronounced under MD.Research highlights: ‘Nubaria-2’, ‘Giza-843’, and ‘Sakha-3’ were more tolerant than ‘Giza-716’ and ‘Sakha-4’, suggesting the use of AsA or Si to ameliorate the IWD effects on stressful cultivars. Certain physiological traits exhibited positive association with growth and seed yield, demonstrating their importance in enhancing seed yield under irrigation treatments
On modeling two immune effectors two strain antigen interaction
In this paper we consider the fractional order model with two immune effectors interacting with two strain antigen. The systems may explain the recurrence of some diseases e.g. tuberculosis (TB). The stability of equilibrium points are studied. Numerical solutions of this model are given. Using integer order system the system oscillates. Using fractional order system the system converges to a stable internal equilibrium. Ulam-Hyers stability of the system has been studied
Using negative velocity feedback controller to reduce the vibration of a suspended cable
The system of suspended cable with mixed excitation forces is controlled in this paper by using negative linear velocity feedback controller. The equations of motion of this system contain quadratic and cubic nonlinearities. The multiple scale perturbation technique is applied to determine the response of the nonlinear system near the simultaneous sub-harmonic and combined resonance case of this system. The stability of the obtained numerical solution is investigated using frequency response equations. The effect of different parameters on the vibrating system are investigated and reported
Vertical Muscle Transposition with Augmentation for Treatment of Exotropia Caused by Iatrogenic Lost Medial Rectus Muscle
Purpose: To evaluate the results of vertical muscle transposition with augmentation in cases of exotropia caused by iatrogenic lost medial rectus muscle.
Methods: This is a retrospective review of 5 cases of lost medial rectus with exotropia and marked limitation of adduction that underwent surgery. All cases had a history of strabismus surgery on the medial rectus and failed attempt at retrieval of the lost muscle.
Results: Five patients fulfilled the criteria. Full tendon vertical muscle transposition with augmentation sutures was done for all cases. Surgery led to a significant reduction of the angle of exotropia 25.8±13.6 ?D (P=0.027) and improvement in adduction of 7.5±3.8 degrees (P=0.034). There were no complications.
Conclusions: Isolated vertical muscle transposition with augmentation is a useful option to improve the exotropia and adduction deficit in patients with iatrogenic lost medial rectus muscle
Evaluation of two freshwater macrophytes, Ceratophyllum demersum and Potamogeton amplifoliusas feed ingredients for Nile tilapia (Oreochromis niloticus) fingerlings
The present study was carried out to evaluate the potential of two common freshwater macrophytes (Ceratophyllum demersum and Potamogeton amplifolius) as feed ingredients for Nile tilapia fingerlings, in two consecutive experiments. The first experiment investigated the use of raw, dried C. demersum and P. amplifolius as sources of energy in the diets of fingerlings. The macrophytes were incorporated in 6 isonitrogenous and isocaloric diets at four levels as a replacement of dietary wheat bran. The test diets were fed to triplicate groups, stocked in 140 L culture aquaria in a recirculating system, three times a day to satiation, for 45 days. The results showed that control, macrophyte-free diet produced significantly improved growth rates and feed utilization efficiency than macrophytes-based diets. In Experiment 2, fermented C. demersum and P. amplifolius were incorporated into six isonitrogenous and isocaloric diets. The diets were fed to triplicate groups of fingerlings (35 g) for 45 days. Growth rates and feed utilization efficiency of fish fed with fermented P. amplifolius at 33 % and 66 % inclusion level were not significantly different from fish fed the control diet. At 100 % inclusion level, fish performance was significantly reduced. On the other hand, fermented C. demersum produced extremely poor performance, compared to raw ceratophyllum. In conclusion, the present results indicated that fermentation improved the quality of P. amplifolius; but not C. demersum
Evaluation of two freshwater macrophytes, Ceratophyllum demersum and Potamogeton amplifoliusas feed ingredients for Nile tilapia (Oreochromis niloticus) fingerlings
37-43The present study was carried out to evaluate the potential of two common freshwater macrophytes (Ceratophyllum demersum and Potamogeton amplifolius) as feed ingredients for Nile tilapia fingerlings, in two consecutive experiments. The first experiment investigated the use of raw, dried C. demersum and P. amplifolius as sources of energy in the diets of fingerlings. The macrophytes were incorporated in 6 isonitrogenous and isocaloric diets at four levels as a replacement of dietary wheat bran. The test diets were fed to triplicate groups, stocked in 140 L culture aquaria in a recirculating system, three times a day to satiation, for 45 days. The results showed that control, macrophyte-free diet produced significantly improved growth rates and feed utilization efficiency than macrophytes-based diets.
In Experiment 2, fermented C. demersum and P. amplifolius were incorporated into six isonitrogenous and isocaloric diets. The diets were fed to triplicate groups of fingerlings (35 g) for 45 days. Growth rates and feed utilization efficiency of fish fed with fermented P. amplifolius at 33 % and 66 % inclusion level were not significantly different from fish fed the control diet. At 100 % inclusion level, fish performance was significantly reduced. On the other hand, fermented C. demersum produced extremely poor performance, compared to raw ceratophyllum. In conclusion, the present results indicated that fermentation improved the quality of P. amplifolius; but not C. demersum
Effect of transdermal nitroglycerin patch on severe preeclamptic women with abnormal Doppler indices
Background: The aim is to evaluate the effect of maternal transdermal nitro-glycerine patch administration on blood flow resistance on maternal uterine artery, fetal umbilical and middle cerebral arteries in patients with severe pre-eclampsia in early gestational age (24 weeks to 33 weeks) associated with abnormal Doppler indices (placental insufficiency) and also its effect on maternal mean arterial blood pressure.Methods: This is a prospective interventional clinical trial conducted on (50) pregnant women with singleton pregnancy diagnosed with severe pre-eclampsia admitted in high-risk pregnancy unit at the Department of Obstetrics in Tanta University Hospitals, A 50-mg transdermal GTN patch (Novartis Pharma) was applied to the abdominal skin, releasing nitroglycerin at a rate of 0.4 mg/h. Doppler ultrasonography and measurement of maternal blood pressure were performed before application of transdermal GTN patch, after 4 hours of application, after 24 hours and after 48 hours.Results: the application of a 50-mg transdermal GTN patch to the maternal abdomen was associated with a significant decline in the PI of the uteroplacental and fetoplacental blood flow. No change was observed in the PI of the cerebral circulation. And also, there was a significant decrease in maternal blood pressure (MAP).Conclusions: Nitroderm patch (nitric oxide donors) may be used as initial therapy in cases of severe preeclampsia complicated by placental insufficiency in the form of abnormal Doppler indices
Common MEFV mutations in Egyptian patients with familial Mediterranean fever
Background: Familial Mediterranean fever (FMF) which is an autosomal recessive condition that primarily affect population of the Mediterranean basin. If undiagnosed effectively and treated with colchicine for life it may lead to serious consequences in terms of renal amyloidosis and renal failure. Objectives: We aim to check for the presence of FMF mutations in clinically suspected Egyptian patients, as an important step for family counseling and case management. Subjects and Methods: The study is a pilot study to check for the presence of FMF mutations among suspected cases (24 cases) from Sharkia Governorate. The control subjects (24) were selected from healthy volunteers. We examined FMF mutations by PCR technique for MEFV gene analysis in order to establish a diagnosis of FMF by examining two mutations, M694V and E148Q. Results: We found 58.3% (14/24 cases) of cohort were positive for M694V mutation, and all cohort were negative for E148Q mutation. The normal controls were negative for previous two mutations. Conclusions: PCR technique provides a rapid, reliable, cost-effective, noninvasive, and sensitive test for establishing a diagnosis of FMF in symptomatic patients and also provides a rational basis for medical and genetic counseling of FMF patients and their families.Key Words: FMF, MEFV, mutations, Egypt
Computational assessment of ballistic impact on a high strength structural steel/polyurea composite plate
Ballistic impact on a polyurea retrofitted high strength structural steel plate is simulated and validated. A soft material model for polyurea, which is capable of capturing complex mechanical behavior characterized by large strains, hysteresis, rate sensitivity, stress softening (Mullins effect), and deviatoric and volumetric plasticity, is calibrated against several uniaxial tension experiments and a threedimensional release wave experiment to capture both the material point and bulk behaviors. A porous plasticity model is employed to model the high strength structural steel and localization elements are included to capture adiabatic shear bands and strain localization. The computational capabilities
of these models are demonstrated by the prediction of the
target plate displacement, which shows excellent agreement
with experiments
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