145 research outputs found

    Unmanned aerial vehicle-aided cooperative regenerative relaying network under various environments

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    This paper studies a cooperative relay network that comprises an unmanned aerial vehicle (UAV) enabling amplify-and-forward (AF) and power splitting (PS) based energy harvesting. The considered system can be constructed in various environments such as suburban, urban, dense urban, and high-rise urban where the air-to-ground channels are model by a mixture of Rayleigh and Nakagami-m fading. Then, outage probability and ergodic capacity are provided under different environment-based parameters. Optimal PS ratios are also provided under normal and high transmit power regimes. Finally, the accuracy of the analytical results is validated through Monte Carlo methods

    1H- AND 13C-NMR SPECTRA OF SOME AZOMETHINES OF 5-AMINO-2-PHENYLINDOLE SERIES

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    The 1H- and 13C-spectra of some azomethines of 5-amino-2-phenylindole series have been recorded and researched. It shown that, the substituents in benzene ring influenced on the chemical shift of proton on azomethine bond

    The impact of intraspecific competition on tree growth in planted Korean pine forest

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    The aim of this study was to explore the correlation of competition indices (CIs) on individual tree growth for Korean pine (Pinus koraiensis) plantation using partial correlation analysis and generalized linear models. The data were collected from 15 permanent plots in Mengjiagang forestry farm, Northeast China. The results showed that the distance dependent CIs have a higher predictive capacity for individual growth of pine trees. The control index of competitive trees number (CI1) combined with the selection fixed competitor trees (M2) was found to be the most well correlated competition measure with five - years diameter increment. Thus, the competition index (CI1- M2) was recommended for developing individual tree growth models. The subject tree diameter at breast height, crown width, height to crown base, tree volume and basal area all showed a significantly linear correlation with tree competition intensity (P 0,05). Diameter at breast height, crown width, tree volume and basal area all decreased with increasing competition intensity, whereas the height to crown base increased. There was no significant relationship between competition intensity and tree height (P 0,05). The optimal model of predicting individual growth with logarithm of diameter at breast height and CIs as the independent variables due to the best fitting performance. This results also showed considerable improvement in predicting individual tree periodic growth when including competition indices that the mean absolute error is reduced in the range of 22−25%.

    Characterization of pig farms in Hung Yen, Hai Duong and Bac Ninh provinces

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    peer reviewedIn order to characterization of pig farms in the Red River Delta, a study was conducted on 90 pig farms in Hung Yen, Hai Duong and Bac Ninh provinces from June to December 2006. Results show that most of the pig farms had been built for five years with a small size (0.5 hectare per farm). The invested capital was about 300-400 millions VND per farm. Four main sow groups used in the farms included crossbred exotic sows (51.1%), crossbred sow between local and exotic breeds (14.4%), purebred Landrace and Yorkshire breeds (15.6 and 18.9%, respectively). The boars were various (Duroc 30%, Yorkshire 21%, Landrace 13%, PiÐtrain × Duroc 36% and others). The pigs farms were faced with several difficulties such as limited land, lack of invested capital, uncontrolled quality of breeding pigs, high costs of feed, poor hygiene condition and diseases

    Discovering Novel Bioactivities of Controversial Food Additives by Means of Simple Zebrafish Embryotoxicity (ZET) Assays

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    peer reviewedThe rising concerns about controversial food additives’ potential hazardous properties require extensive yet animal-minimized testing strategies. Zebrafish embryos are the ideal in vivo model representing both human and environmental health. In this study, we exposed zebrafish embryos to eight controversial food additives. Our results indicate that Sodium Benzoate is a Cat.3 aquatic toxicant, while Quinoline Yellow is a strong teratogen. At high concentrations, non-toxic chemicals induced similar phenotypes, suggesting the impact of ionic strength and the applicability of the darkened yolk phenotype as an indicator of nephrotoxicity. Three food additives showed unpredicted bioactivities on the zebrafish embryos: Brilliant Blue could weaken the embryonic yolk, Quinoline Yellow may interfere with nutrient metabolism, and Azorubine induced precocious zebrafish hatching. In conclusion, the zebrafish embryo is ideal for high throughput chemical safety and toxicity screening, allowing systematic detection of biological effects—especially those unexpected by targeted in vitro and in silico models. Additionally, our data suggest the need to reconsider the safety status of food additives Quinoline Yellow, Brilliant Blue, Sodium Benzoate, and other controversial food additives in further studies, as well as pave the way to further applications based on the newly found properties of Brilliant Blue and Azorubine.Test d'additifs alimentaires et de leurs propriétés biologiques sur cellules et sur les poissons zèbres3. Good health and well-bein

    Belgium

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    peer reviewedPurpose: Traditional medicines have been used in Vietnam for thousands of years, and still play an essential role in healthcare. However, so far, there is no clear definition of circumstances in which plants can be collected, conserved, and extracted; viable models for a productive and sustainable exploitation of natural extracts are missing, sometimes leading to severe and unfavorable consequences on health. In this study, we aim to develop a cost-effective pipeline to assess the pharmaco-/toxicological properties of these medicinal materials using the zebrafish embryo as an in vivo model. Methods: Medicinal plants extracts were prepared by incorporating in the design more standardized methods as the traditional ones, using increasing polarity solvents. After that, the zebrafish has been chosen as a whole animal model to determine the core of the biological properties of a specific extract. Embryotoxicity was analyzed by exposing extracts to zebrafish embryos, which were monitored at specific times during 4 days for survival and the presence of developmental malformations. In addition, the zebrafish transgenic line Tg(fli1:EGFP) displaying fluorescent endothelial cells was used to visualize blood vessels and detect effects on angiogenesis. Proof-of-concept experiments were done by passing samples from two plants: Caesalpinia sappan L. and Glochidion eriocarpum to evaluate its efficiency. Results: Effects of C. sappan L. extract on zebrafish embryonic morphology and lethality were determined in the corresponding concentration-response curves (LC50=500 mg/L and EC50=40 mg/L). Analysis of transgenic zebrafish showed the anti-angiogenic properties in a dose dependent manner. In addition, the interaction between this plant extract and the embryo chorion was explored. On the other hand, G. eriocarpum extract exposure led to a biphasic response from the zebrafish embryos, suggesting a protective role of the embryonic chorion. Our results may contribute to the design of a rational high throughput pharmacological screening approach using the zebrafish model

    Spontaneous Symmetry Breaking of Solitons Trapped in a Double-Gauss Potentials

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    We consider an extended model of the model considered before with double-square potential, namely one-dimensional (1D) nonlinear Schrödinger equation (NLSE) with self-focusing nonlinearity and a 1D double-gauss potential. Spontaneous symmetry breaking has been presented in terms of the control parameter which is propagation constant in the case of optics and chemical potential in the of Bose-Einstein Condensate (BEC), correspondingly. The numerical simulations predict a bifurcation breaking the symmetry of 1D trapped in the double-gauss potential of the supercritical type as in the case of double-square potential. Furthermore we have constructed bifurcation diagrams considering the stability of solitons with three methods: the method using Vakhitov–Kolokolov (V-K) Stability Criterion, Pseudospectral Method and Method for Linear-Stability Eigenvalues. It will be shown that for our model the results obtained are the same for these three methods but the third one is the fastest
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