Optimum Functions for Radial Wires of Monopole Antennas with Arbitrary Elevation Angles

Monopole antennas on the earth usually use ground screen with simple radial wires to improve their radiation performance. The number of radials,N, is usually considered a constant in the screen. This paper studies the effect of changing N and considering it as a function of distance, ρ, from the monopole using a simple and yet a fast method. The function N(ρ) is optimized for different beam angles of an HF monopoleantenna. The theoretical functions are converted to practical functions to be formed using meandered lines. Practicable calculated results are validated bymethod of moments. Furthermore it is shown that for low angle radiation aconstant N(ρ) with optimized radius of the ground screen is the best choice. The results can be used for higher frequencies, i.e. VHF and UHF frequency bands as well

Efecto de la radiación gamma sobre el perfil lipídico de los aceites de semillas de soja, cacahuete y sésamo

Seeds of soybean, peanut, and sesame were exposed to various doses of gamma irradiation (0.0, 0.5, 1.0, 2.0, 3.0, 5.0 and 7.5 kGy). Fatty acid and unsaponifiable profiles of the extracted oils were separated by gas chromatography mass spectroscopy. The results demonstrated that the ratios of unsaturated to saturated total fatty acids (TU/TS) and total hydrocarbons to sterols (TH/TSt) were significantly altered upon irradiation. These changes were clearly observed in the oil extracted from irradiated sesame seeds compared with the oils from irradiated peanuts and soybean. The major change in fatty acid composition was the decrease in the quantity of unsaturated fatty acids (C18:1 and C18:2) in all cases. In contrast, the sterol fractions such as cholesterol, campesterol, stigmasterol and β-sitosterol levels of irradiated seeds were generally lower than that of the un-irradiated seeds.Semillas de soja, cacahuete y de sésamo se expusieron a diferentes dosis de radiación gamma (0,0, 0,5, 1,0, 2,0, 3,0, 5,0 y 7,5 kGy). Se determinaron los perfiles de ácidos grasos y el insaponificable de los aceites mediante cromatografía de gases y espectrometría de masas. Los resultados demostraron que las relaciones de ácidos insaturados a ácidos grasos totales saturados (TU/TS) e hidrocarburos totales a esteroles (TH/TSt) se alteró significativamente tras la irradiación. Estos cambios se observaron claramente en el aceite extraído de las semillas de sésamo irradiados, en comparación con los aceites de soja y cacahuetes irradiados. El mayor cambio en la composición de ácidos grasos fue la disminución de la cantidad de ácidos grasos insaturados (C18:1 y C18:2) en todos los casos. En contraste, los niveles de las fracciones de esteroles como colesterol, campesterol, estigmasterol y β-sitosterol de las semillas irradiadas fueron en general más bajo que el de las semillas sin irradiados

Therapeutic role of bone marrow mesenchymal stem cells in diabetic neuronal alternations of rat hippocampus

Background: As the hippocampus is the main brain region for many forms of learning and memory functions and is acutely sensitive to blood glucose changes, diabetes mellitus, which is a serious metabolic disease, is often accompanied by learning and memory deficits. Through scientific literatures, mesenchymal stem cells (MSCs) promote functional recovery in rats with traumatic brain injury, so the present work was conducted to study MSCs as a possible treatment for the diabetic neuronal degeneration and functional impairment of rat hippocampus. Materials and methods: It was carried out using male albino rats: non-diabetic control groups (4, 8, 12 weeks) (n = 15), diabetic groups by i.v. injection of streptozotocin for (4, 8, 12 weeks) (n = 15) and MSCs treatment to diabetic groups for (8, 12 weeks) (n = 10). Hippocampal learning and memory functions were assessed by the Morris Water Maze test and its results were statistically analysed. The rat hippocampal regions (CA1 and CA3) were subjected to histological, ultrastructural examination and morphometrical analyse of pyramidal neurons. Results: Neurons of the diabetic groups showed disturbed function and architecture; shrunken hyperchromatic nuclei and vacuolated eosinophilic cytoplasm (apoptotic changes) also MSCs treatment improved hippocampal learning and memory functions plus its architectural changes; increasing populations and normal regular distribution. Conclusions: It can be concluded that diabetic hippocampal neuronal alternations and functional impairment can be ameliorated by MSCs treatment

The effect of nitro-oleic versus losartan in diabetic nephropathy: modulation of parathyroid hormone-related protein

Background: Parathyroid hormone-related protein (PTHrP) involvement in the mechanisms related to angiotensin II (AngII)-induced renal injury has become an emerging concern. The current study was thus designed to compare the possible preventive and therapeutic effect of AngII antagonists, losartan and nitro-oleic (NO2-OA) acid, on diabetic nephropathy (DN) and evaluate their effect on PTHrP modulation as well as on the functional and histopathological parameters in the kidney of diabetic rats.  Materials and methods: Forty eight adult male Sprague Dawley rats were divided into control group, DN group, pre-diabetic nephropathy (pre-DN) losartan group, pre-diabetic nephropathy nitro-oleic acid (pre-DN NO2-OA) group, post-diabetic nephropathy (post-DN) losartan and post-diabetic nephropathy nitro-oleic acid (post-DN NO2-OA) groups. At the end of the study, systolic blood pressure (SBP), serum fasting glucose, glomerular filtration rate (GFR), urea, urea albumin excretion (UAE), serum angiotensin, renal PTHrP gene expression and correlations between PTHrP and SBP, serum glucose, AngII and kidney functions were evaluated. Histo- logical examination, Masson’s trichrome, periodic acid-Schiff staining as well as morphometric analysis and histopathological scoring for tubular and glomerular parameters have been carried out.  Results: Prophylactic losartan and NO2-OA were associated with improvement in SBP, serum glucose, urea, GFR, UAE, with reduction in serum AngII and PTHrP overexpression observed in diabetic kidney. Treatment with losartan and NO2-OA showed the same effect except that post-DN NO2-OA showed no significant effect regarding kidney function. Strong correlations were observed between PTHrP and SBP, serum glucose, AngII and kidney functions. Histopathological results revealed obvious improvement in glomerulosclerosis, vascular and tubular injury parameters in prophylactic groups especially with losartan.  Conclusions: Both pre and post-DN losartan, NO2-OA may have a potential role in protection and regression of DN through reduction of PTHrP overexpression.

Antioxidant and anticholinergic properties of Citrus sinensis (L.) Osbeck (Rutaceae) essential oil in mice hippocampus

This study evaluated anti-acetylcholinesterase and antioxidant potentials in mice hippocampus treated with essential oils (EO) of Citrus sinensis (L.) Osbeck (orange) in vitro and in vivo. The acetylcholinesterase (AChE) activity was evaluated by using an adapted spectrophotometric method by Ellman after administration (30 consecutive days) in albino mice at doses of 50.00 mg/kg (EO 50), 100.00 mg/kg (EO 100) and 200.00 mg/kg (EO 200). The results showed that there was a significant decrease on enzymatic activity of AChE in mice hippocampus treated with essential oil of C. sinensis at doses of 50.00 mg/kg (vehicle= 9.89±0.19, OE 50= 2.63±0.21) [P <0.05], 100.00 mg/kg (vehicle= 9.89±0.19, EO 100= 1.65±0.15) [P <0.05] and 200.00 mg/kg (vehicle= 9.89±0.19, EO 200= 2.38±0.12) [P <0.05] when compared with vehicle group (0.05% Tween 80 dissolved in saline 0.9%). Concerning antioxidant activity, there was a significant reduction (P <0.05) of 20% on lipid peroxidation level in mice hippocampus treated with a dose of 200.00 mg/kg. The results obtained from the current studies showed that the essential oil of C. sinensis has considerable antioxidant and activity and inhibitory effect on AChE

Antioxidant and anticholinergic properties of Citrus sinensis (L.) Osbeck (Rutaceae) essential oil in mice hippocampus

199-205This study evaluated anti-acetylcholinesterase and antioxidant potentials in mice hippocampus treated with essential oils (EO) of Citrus sinensis (L.) Osbeck (orange) in vitro and in vivo. The acetylcholinesterase (AChE) activity was evaluated by using an adapted spectrophotometric method by Ellman after administration (30 consecutive days) in albino mice at doses of 50.00 mg/kg (EO 50), 100.00 mg/kg (EO 100) and 200.00 mg/kg (EO 200). The results showed that there was a significant decrease on enzymatic activity of AChE in mice hippocampus treated with essential oil of C. sinensis at doses of 50.00 mg/kg (vehicle= 9.89±0.19, OE 50= 2.63±0.21) [P P P P C. sinensis has considerable antioxidant and activity and inhibitory effect on AChE

Optimised phase disposition pulse-width modulation strategy for hybrid-clamped multilevel inverters using switching state sequences

This study describes an optimised modulation strategy based on switching state sequences for the hybrid-clamped multilevel converter. Two key control variables defined as 'phase shift angle' and 'switching state change' for a five-level hybrid-clamped inverter are proposed to improve all switches' operation, and by changing their values, different control methods can be obtained for modulation optimisation purposes. Two example methods can solve the voltage imbalance problem of the dc-link capacitors and furthermore avoid two switches' simultaneous switching transitions and improve the inverter's performance as compared with the traditional phase disposition pulse-width modulation strategy. A 6 kW prototype inverter is developed and a range of simulation and experiments are carried out for validation. It is found that simulation and experimental results are in a good agreement and the proposed modulation strategy is verified in terms of low-order harmonic reduction

Comparison of two novel MRAS strategies for identifying parameters in permanent magnet synchronous motors

Two Model Reference Adaptive System (MRAS) estimators are developed for identifying the parameters of permanent magnet synchronous motors (PMSM) based on Lyapunov stability theorem and Popov stability criterion, respectively. The proposed estimators only need online detection of currents, voltages and rotor rotation speed, and are effective in the estimation of stator resistance, inductance and rotor flux-linkage simultaneously. Their performances are compared and verified through simulations and experiments. It shows that the two estimators are simple and have good robustness against parameter variation and are accurate in parameter tracking. However, the estimator based on Popov stability criterion, which can overcome the parameter variation in a practical system, is superior in terms of response speed and convergence speed since there are both proportional and integral units in the estimator in contrast to only one integral unit in the estimator based on Lyapunov stability theorem. In addition, there is no need of the expert experience which is required in designing a Lyapunov function

A critical perspective on second-order empathy in understanding psychopathology: phenomenology and ethics

The centenary of Karl Jaspers’ General Psychopathology was recognised in 2013 with the publication of a volume of essays dedicated to his work (edited by Stanghellini and Fuchs). Leading phenomenological-psychopathologists and philosophers of psychiatry examined Jaspers notion of empathic understanding and his declaration that certain schizophrenic phenomena are ‘un-understandable’. The consensus reached by the authors was that Jaspers operated with a narrow conception of phenomenology and empathy and that schizophrenic phenomena can be understood through what they variously called second-order and radical empathy. This article offers a critical examination of the second-order empathic stance along phenomenological and ethical lines. It asks: (1) Is second-order empathy (phenomenologically) possible? (2) Is the second-order empathic stance an ethically acceptable attitude towards persons diagnosed with schizophrenia? I argue that second-order empathy is an incoherent method that cannot be realised. Further, the attitude promoted by this method is ethically problematic insofar as the emphasis placed on radical otherness disinvests persons diagnosed with schizophrenia from a fair chance to participate in the public construction of their identity and, hence, to redress traditional symbolic injustices