456 research outputs found
Flux pinning mechanism in BaFe1.9Ni0.1As2 single crystals: Evidence for fluctuation in mean free path induced pinning
The flux pinning mechanism of BaFe1.9Ni0.1As2 superconducting crystals have been investigated systematically by magnetic measurements up to 13 T at various temperatures. The field dependence of the critical current density, Jc, was analysed within the collective pinning model. A remarkably good agreement between the experimental results and theoretical dl pinning curve is obtained, which indicates that pinning in BaFe1.9Ni0.1As2 crystal originates from spatial variation of the mean free path. Moreover, the normalized pinning force density, Fp, curves versus h1/4B/Birr (Birr is the irreversibility field) were scaled using the Dew-Hughes model. Analysis suggests that point pinning alone cannot explain the observed field variation of Fp
Comparative screening of chloramphenicol residue in chicken tissues using four plate test and Premi®Test methods
Background: The safety of food with animal origin means that the food consumed is considered as safe when synthetic chemical agents are absent or present at very low concentrations. The aims of the present study were to validate the Premi®Test and four plate test (FPT) methods as well as screen and estimate the occurrence of chloramphenicol (CAP) residue in collected chicken tissues including liver, kidney and thigh muscle from Kermanshah, west of Iran. Methods: A total of 150 chicken samples were purchased from different poultry slaughterhouses in Kermanshah province, west of Iran and subjected to the FPT and Premi®Test. Results: The Premi®Test could not detect CAP residue at concentrations below 3 and 6 ppm in aqueous solution and kidney fluid, respectively. The highest sensitivity of FPT in the detection of CAP residue was optimally found in the agar medium inoculated with Bacillus subtilis at pH 7.2. The Premi®Test was more sensitive than FPT in the kidney fluid and aqueous solution. Regarding FPT results, CAP residue was found in 20 (n=30), 8.66 (n=28) and 11.33 (n=17) of liver, kidney and muscle samples, respectively. In the case of Premi®Test, the most contaminated samples were liver (24), followed by kidney (22.66) and muscle (19.33). Conclusion: It can be concluded that illegal use of CAP in Iranian poultry industries should be taken into account seriously. © 2018 The Authors
Comparison of biological aspects of olive fly, Bactrocera oleae (Dip.: Tephritidae), on olive varieties under laboratory conditions
The olive fly, Bactrocera oleae is an important pest of olive groves. Biology of this pest was investigated on five varieties of olive under laboratory conditions at temperature 25 ï± 2ï°C, 65 ï± 5% RH and 16L: 8D. The results showed that there is not any significant difference on the total developmental time of immature stages of olive fly reared on five olive varieties. However, developmental time of larvae on two varieties of Zard and Golouleh showed significant difference with those fed on Shenge, Roghani and Marri. The generation times estimated on Marri, Roghani, Zard, Shenge and Golouleh varieties were 93.24 ï± 5.24, 91.56 ï± 5.78, 86.74 ï± 3.92, 84.86 ï± 2.39 and 82.56 ï± 2.85 days, respectively. The mean pre-oviposition period of the fly was 5.53 ï± 0.52 days and the mean time for the female to mate once again was 10.05 ï± 0.67 days. The female oviposition rate was affected by olive varieties. The mean number of the eggs laid by each female on olive fruit varieties of Goloule, Zard, Shenge, Roghani and Marri was obtained 340 ï± 69.9, 254 ï± 20.88, 221.75 ï± 45.44, 203.25 ï± 43.5 and 110.25 ï± 50.45, correspondingly. The mean longevity of the non-feeding male and female flies was estimated 2.92 ï± 0.2 and 3.16 ï± 0.21 days and it was 75.64 ï± 6.96 and 86.16 ï± 6.18 days for well-fed male and female flies with honey and water, respectively. The mean longevity of the well-fed male and female flies decreased to 56.55 ï± 3.53 and 67.7 ï± 4.18 days, respectively, as they had matting activity and olive fruits were presented to them for female oviposition
Neural-Network-Controlled Spring Mass Template for Humanoid Running
To generate dynamic motions such as hopping and running on legged robots, model-based approaches are usually used to embed the well studied spring-loaded inverted pendulum (SLIP) model into the whole-body robot. In producing controlled SLIP-like behaviors, existing methods either suffer from online incompatibility or resort to classical interpolations based on lookup tables. Alternatively, this paper presents the application of a data-driven approach which obviates the need for solving the inverse of the running return map online. Specifically, a deep neural network is trained offline with a large amount of simulation data based on the SLIP model to learn its dynamics. The trained network is applied online to generate reference foot placements for the humanoid robot. The references are then mapped to the whole-body model through a QP-based inverse dynamics controller. Simulation experiments on the WALK-MAN robot are conducted to evaluate the effectiveness of the proposed approach in generating bio-inspired and robust running motions
Phase synchronization on scale-free and random networks in the presence of noise
In this work we investigate the stability of synchronized states for the
Kuramoto model on scale-free and random networks in the presence of white noise
forcing. We show that for a fixed coupling constant, the robustness of the
globally synchronized state against the noise is dependent on the noise
intensity on both kinds of networks. At low noise intensities the random
networks are more robust against losing the coherency but upon increasing the
noise, at a specific noise strength the synchronization among the population
vanishes suddenly. In contrast, on scale-free networks the global
synchronization disappears continuously at a much larger critical noise
intensity respect to the random networks
A transcriptomic, metabolomic and cellular approach to the physiological adaptation of tomato fruit to high temperature
Magnetoresistance, critical current density, and magnetic flux pinning mechanism in nickel doped BaFe 2
Common genetic variability in ESR1 and EGF in relation to endometrial cancer risk and survival
We investigated common genetic variation in the entire ESR1 and EGF genes in relation to endometrial cancer risk, myometrial invasion and endometrial cancer survival. We genotyped a dense set of single-nucleotide polymorphisms (SNPs) in both genes and selected haplotype tagging SNPs (tagSNPs). The tagSNPs were genotyped in 713 Swedish endometrial cancer cases and 1567 population controls and the results incorporated into logistic regression and Cox proportional hazards models. We found five adjacent tagSNPs covering a region of 15 kb at the 5′ end of ESR1 that decreased the endometrial cancer risk. The ESR1 variants did not, however, seem to affect myometrial invasion or endometrial cancer survival. For the EGF gene, no association emerged between common genetic variants and endometrial cancer risk or myometrial invasion, but we found a five-tagSNP region that covered 51 kb at the 5′ end of the gene where all five tagSNPs seemed to decrease the risk of dying from endometrial cancer. One of the five tagSNPs in this region was in strong linkage disequilibrium (LD) with the untranslated A61G (rs4444903) EGF variant, earlier shown to be associated with risk for other forms of cancer
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