289 research outputs found
Vortex-antivortex pair driven magnetization dynamics studied by micromagnetic simulations
The magnetization dynamics approaching an equilibrium vortex state from an initial nonequilibrium state under zero magnetic field in a circular shaped Fe disk with thickness of 5 nm and a diameter of 1200 nm were studied. Starting from the initial random configuration of in-plane magnetizations, a great number of vortex and antivortex pairs energetically favorable to form were generated at a lot of nucleation sites. It was found that the sites propagated and then were annihilated by their attractive interactions during the relaxation dynamic process. The study shows that temporal magnetization evolutions can be dominated by the nucleation of the vortex and antivortex pairs, followed by their propagation and annihilation.open222
Analog Self-Interference Cancellation With Practical RF Components for Full-Duplex Radios
One of the main obstacles in full-duplex radios is analog-to-digital converter (ADC) saturation on a receiver due to the strong self-interference (SI). To solve this issue, researchers have proposed two different types of analog self-interference cancellation (SIC) methods—i) passive suppression and ii) regeneration-and-subtraction of SI. For the latter case, the tunable RF component, such as a multi-tap circuit, reproduces and subtracts the SI. The resolutions of such RF components constitute the key factor of the analog SIC. Indeed, they are directly related to how well the SI is imitated. Another major issue in analog SIC is the inaccurate estimation of the SI channel due to the nonlinear distortions, which mainly come from the power amplifier (PA). In this paper, we derive a closed-form expression for the SIC performance of the multi-tap circuit; we consider how the RF components must overcome such practical impairments as digitally-controlled attenuators, phase shifters, and PA. For a realistic performance analysis, we exploit the measured PA characteristics and carry out a 3D ray-tracing-based, system-level throughput analysis. Our results confirm that the non-idealities of the RF components significantly affect the analog SIC performance. We believe our study provides insight into the design of the practical full-duplex system
Growth Performance, Relative Meat and Organ Weights, Cecal Microflora, and Blood Characteristics in Broiler Chickens Fed Diets Containing Different Nutrient Density with or without Essential Oils
The present study was conducted to investigate whether dietary essential oils could affect growth performance, relative organ weights, cecal microflora, immune responses and blood profiles of broiler chickens fed on diets containing different nutrient densities. A total of eight hundred-forty 1-d-old male broiler chicks were randomly allotted into twenty-eight pens (7 pens per treatment, 30 chicks per pen). There were four experimental diets containing two different nutrient densities and supplemented with or without essential oils. Experimental period lasted for 35 days. No clear interaction between nutrient density and essential oils on any of growth performance-related parameters was observed. Live body weights were affected (p<0.05) by nutrient density at 21 days and by dietary essential oils at 35 days. Essential oils significantly (p<0.05) increased daily body weight gain and feed conversion ratio during the periods of 22 to 35 and 1 to 35 days, but failed to affect feed intake during the entire experimental period. Daily weight gain at 1 to 21 days and feed intake at 1 to 21 and 1 to 35 days were significantly impaired (p<0.05) by nutrient density. There were significant treatment interactions (p<0.05) on relative weights of bursa of Fabricius and abdominal fat contents. Finally, either essential oil or nutrient density did not influence the relative percentages of breast and leg meats, the population of cecal microflora, blood parameters and antibody titers against Newcastle disease and infectious bronchitis in broiler chickens. It was concluded that dietary essential oils, independent to nutrient density, failed to stimulate feed intake, but increased growth performance in broiler chickens
Vortex-antivortex assisted magnetization dynamics in a semi-continuous thin-film model system studied by micromagnetic simulations
We have studied magnetization M dynamics in a semicontinuous 33-nm -thick Fe model system, which approaches new equilibrium states under various magnetic fields, H=0, -1, -10, and -30 Oe, starting from an initial M configuration of complex microstructures experimentally observed in a real continuous Fe film. Simulation results with H=0 clearly reveal that small needle-shaped domains and ripple structures found in a frozen state of the demagnetized Fe film continue to grow far into a surrounding 180?? domain, and that zigzag folding structures appear through the M dynamic evolution assisted by vortex and antivortex. Furthermore, it is found that many domain walls of a cross-tie type exhibit their dynamic developments under H=-10 and -30 Oe, caused by interactions between vortex and antivortex states. This vortex-antivortex assisted M dynamic evolution offers deeper insights into the comprehensive understanding of the static or dynamic properties of M reversal processes as well as additional features or more details of magnetic microstructures in real continuous films.open141
Pig-to-Nonhuman Primate (NHP) Naked Islet Xenotransplantation
Islet transplantation is an established therapy for selected type 1 diabetes (T1D) patients with severe hypoglycemic unawareness and glycemic liability despite of insulin treatment. However, the donor organ is limited. Porcine islets are the best alternative source to overcome this limitation, and pig-to-nonhuman primate (NHP) naked islet xenotransplantation studies are being performed worldwide. Several studies including our own have presented successful proof-of-concept results based on immunosuppression regimen including the anti-CD154 monoclonal antibody. Particularly, long-term control of diabetes by adult porcine islet transplantation has been demonstrated in five consecutive monkeys, and the longest survival was ~1000 days after transplantation. Currently, pig-to-NHP islet xenotransplantation based on clinically applicable immunosuppression regimen is being pursued. In this chapter, we will describe all the procedures of pig-to-NHP naked islet xenotransplantation: (1) the porcine islet isolation from designated pathogen-free (DPF) miniature pigs, (2) diabetes induction in monkeys, (3) transplantation procedure via the portal vein, (4) immune monitoring comprising humoral and cellular immunity after porcine islet transplantation, and finally (5) liver biopsy and subsequent immunohistochemical procedure in detail
SynechoNET: integrated protein-protein interaction database of a model cyanobacterium /Synechocystis/ sp. PCC 6803.
Background: Cyanobacteria are model organisms for studying photosynthesis, carbon and nitrogen assimilation, evolution of plant plastids, and adaptability to environmental stresses. Despite many studies on cyanobacteria, there is no web-based database of their regulatory and signaling protein-protein interaction networks to date. Description: We report a database and website SynechoNET that provides predicted protein-protein interactions. SynechoNET shows cyanobacterial domain-domain interactions as well as their protein-level interactions using the model cyanobacterium, Synechocystis sp. PCC 6803. It predicts the protein-protein interactions using public interaction databases that contain mutually complementary and redundant data. Furthermore, SynechoNET provides information on transmembrane topology, signal peptide, and domain structure in order to support the analysis of regulatory membrane proteins. Such biological information can be queried and visualized in user-friendly web interfaces that include the interactive network viewer and search pages by keyword and functional category. Conclusion: SynechoNET is an integrated protein-protein interaction database designed to analyze regulatory membrane proteins in cyanobacteria. It provides a platform for biologists to extend the genomic data of cyanobacteria by predicting interaction partners, membrane association, and membrane topology of Synechocystis proteins. SynechoNET is freely available at http://synechocystis.org/or directly at http://bioportal.kobic.kr/SynechoNET/close128
Genetic polymorphism and natural selection of Duffy binding protein of Plasmodium vivax Myanmar isolates
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