The role of the triangle singularity in Λ(1405)\Lambda(1405) production in the π−p→K0πΣ\pi^-p\rightarrow K^0\pi\Sigma and pp→pK+πΣpp\rightarrow pK^+\pi\Sigma processes

We have investigated the cross section for the $\pi^-p\rightarrow K^0\pi\Sigma$ and $pp\rightarrow pK^+\pi\Sigma$ reactions paying attention to a mechanism that develops a triangle singularity. The triangle diagram is realized by the decay of a $N^*$ to $K^*\Sigma$ and the $K^*$ decay into $\pi K$, and the $\pi\Sigma$ finally merges into $\Lambda(1405)$. The mechanism is expected to produce a peak around $2140$ MeV in the $K\Lambda(1405)$ invariant mass. We found that a clear peak appears around $2100$ MeV in the $K\Lambda(1405)$ invariant mass which is about $40$ MeV lower than the expectation, and that is due to the resonance peak of a $N^*$ resonance which plays a crucial role in the $K^*\Sigma$ production. The mechanism studied produces the peak of the $\Lambda(1405)$ around or below 1400 MeV, as is seen in the $pp\rightarrow pK^+\pi\Sigma$ HADES experiment.Comment: 12 pages, 9 figure

Possible improvements of global optimization methods inspired by nature

This study focuses on the global optimization of functions of real variables using methods inspired by nature. It contains a description of selected global optimization techniques (Differential Evolution, Self-Organizing Migrating Algorithm, Steady-State Evolutionary Algorithm, Particle Swarm Optimization, Gregarious Particle Swarm Optimizer a Hybrid Particle Swarm with Differential Evolution Operator). I have found four improvements of these techniques, discovered their suitable parameter configurations and compared them on chosen trial functions. Experimental results proved that described improvements can increase performance of the optimization techniques inspired by nature

Distribution of the MTRR A66G polymorphism among populations in China.

<p>Distribution of the MTRR A66G polymorphism among populations in China.</p

Geographical and Ethnic Distributions of the MTHFR C677T, A1298C and MTRR A66G Gene Polymorphisms in Chinese Populations: A Meta-Analysis

<div><p>Background</p><p>The geographical and ethnic distributions of the polymorphic methylenetetrahydrofolate reductase (MTHFR) mutations (C677T and A1298C) and methionine synthase reductase (MTRR) mutation (A66G) remain heterogeneous in China. The goal of this study was to estimate the pooled frequencies of the alleles and associated genotypes of these gene polymorphisms among healthy populations in Mainland China.</p><p>Objective and Methods</p><p>We systematically reviewed published epidemiological studies on the distributions of 3 genetic variants in Chinese healthy populations living in Mainland China through a meta-analysis. The relevant electronic databases were searched. All of the raw data of the eligible citations were extracted. The frequency estimates were stratified by geography, ethnicity and sex.</p><p>Results</p><p>Sixty-six studies were identified with a total of 92277 study participants. The meta-analysis revealed that the frequencies of the MTHFR C677T, A1298C, and MTRR A66G gene polymorphisms varied significantly between different ethnic groups and along geographical gradients. The frequencies of the 677T allele and 677TT genotype increased along the southern-central-northern direction across Mainland China (all <i>P</i>values≤0.001). The frequencies of the 1298C, 1298CC, 66G and 66GG genotypes decreased along the south-central-north direction across the country (all <i>P</i>values≤0.001).</p><p>Conclusions</p><p>Our meta-analysis strongly indicates significant geographical and ethnic variations in the frequencies of the C677T, A1298C, and A66G gene polymorphisms in the folate metabolism pathway among Chinese populations.</p></div

Distribution of the MTHFR A1298C polymorphism among populations in China.

<p>Distribution of the MTHFR A1298C polymorphism among populations in China.</p

Distribution of the MTHFR C677T polymorphism among populations in China.

<p>Distribution of the MTHFR C677T polymorphism among populations in China.</p

Flow chart of the study selection process.

<p>Flow chart of the study selection process.</p