Viện Hàn lâm Khoa học và Công nghệ Việt Nam

The flipped 3-3-1 model discriminates lepton families instead of the quark ones in normal sense, where the left-handed leptons are in two triplets plus one sextet while the left-handed quarks are in antitriplets, under SU(3)L. We investigate a minimal setup of this model and determine novel consequences of dark matter stability, neutrino mass generation, and lepton flavor violation. Indeed, the model conserves a noncommutative B−L symmetry, which prevents the unwanted vacua and interactions and provides the matter parity and dark matter candidates that along with normal matter form gauge multiplets. The neutrinos obtain suitable masses via a type I and II seesaw mechanism. The nonuniversal couplings of Z′ with leptons govern lepton flavor violating processes such as μ → 3e, μ → e $$ \overline{\nu} $$ μνe, μ-e conversion in nuclei, semileptonic τ → μ(e) decays, as well as the nonstandard interactions of neutrinos with matter. This Z′ may also set the dark matter observables and give rise to the LHC dilepton and dijet signals.

Understanding the method and history of introduction in non-native species are essential for conservation biology, especially in regions like Japan that have a long history of human activity. Bradybaena similaris is a circumtropical land snail that is considered a non-native species from Southeast Asia or East Asia to Japan, which was believed to be introduced by human activities such as sugarcane or sweet potato establishment several hundred years ago. Bradybaena pellucida, a sister species of B. similaris, is native to western Japan, but has recently spread throughout the eastern part of the country. We investigated genetic diversification pattern of non-native organisms using the two land snail species. We clarified the phylogenetic relationships of B. similaris and B. pellucida based on genome-wide SNPs and mtDNA. We revealed the population demographic history using ABC analysis with SNP data. Bradybaena similaris of mainland Japan could be distinguished from populations on the continent. Introgressive hybridization between the species occurred approximately 29,700 years ago. The present findings provide two new hypotheses: that agriculture began in Japan about 2800 years ago, Japanese populations of B. similaris were introduced from the continent more than 29,000 years ago by human activity other than agriculture; or B. similaris is native to a part of mainland Japan. The history of a non-native species with human activity is complex, urging us to reconsider previous hypotheses.

We herein report Mannich aminomethylation of variously structural flavonoids and their biological evaluation against human breast cancer cell. Mannich reaction showed that substitution at C-6 position depends on amine basicity and C-ring feature of flavonoids. All five flavonoid substrates reacted with strong amine bases to afford the bis(6,8-aminomethyl) derivatives, while with weak amines, the different products were obtained dependently on structural characteristic of flavonoid. 3-OH and 3-O-substituted groups on the C-ring exhibited the deactivated aminomethylation at C-6 position, whereas substitution at this position was independent on bond feature at C-2 and C-3 on the C-ring. Screening anti-proliferative activity showed six flavonoids possessed activity against breast cancer cell, MDA-MB-231. Among them, the flavonoids, luteolin (2) and 3′,4′,5,7-tetrahydroxy-6,8-bis(pyrrolidin-1-ylmethyl)-3-rutinosylflavone (3a), displayed the highest anti-proliferative activity with the lowest IC50 values.

In this paper, we study the existence of optimal solutions to a constrained polynomial optimization problem. More precisely, let $$f_0$$ and $$f_1, \ldots , f_p :{\mathbb {R}}^n \rightarrow {\mathbb {R}}$$ be convenient polynomial functions, and let $$S := \{x \in {\mathbb {R}}^n \ : \ f_i(x) \le 0, i = 1, \ldots , p\} \ne \emptyset .$$ Under the assumption that the map $$(f_0, f_{1}, \ldots , f_{p}) :{\mathbb {R}}^n \rightarrow {\mathbb {R}}^{p + 1}$$ is non-degenerate at infinity, we show that if $$f_0$$ is bounded from below on $$S,$$ then $$f_0$$ attains its infimum on $$S.$$