Direct Emission of I_2 Molecule and IO Radical from the Heterogeneous Reactions of Gaseous Ozone with Aqueous Potassium Iodide Solution

Recent studies indicated that gaseous halogens mediate key tropospheric chemical processes. The inclusion of halogen-ozone chemistry in atmospheric box models actually closes the ~50% gap between estimated and measured ozone losses in the marine boundary layer. The additional source of gaseous halogens is deemed to involve previously unaccounted for reactions of O_3(g) with sea surface water and marine aerosols. Here, we report that molecular iodine, I_2(g), and iodine monoxide radical, IO(g), are released ([I_2(g)] > 100[IO(g)]) during the heterogeneous reaction of gaseous ozone, O_3(g), with aqueous potassium iodide, KI(aq). It was found that (1) the amounts of I_2(g) and IO(g) produced are directly proportional to [KI(aq)] up to 5 mM and (2) IO(g) yields are independent of bulk pH between 2 and 11, whereas I_2(g) production is markedly enhanced at pH < 4. We propose that O_3(g) reacts with I− at the air/water interface to produce I_2(g) and IO(g) via HOI and IOOO− intermediates, respectively

Schur–Weyl Reciprocity for Ariki–Koike Algebras

AbstractLet g=glm1⊕···⊕glmr be a Levi subalgebra of glm, with m=∑ri=1mi, and V the natural representation of the quantum group Uq(g). We construct a representation of the Ariki–Koike algebra Hn,r on the n-fold tensor space of V, commuting with the action of Uq(g), and prove the Schur–Weyl reciprocity for the actions of Uq(g) and Hn,r on it

Vacuum Effects and Compressional Properties of Nuclear Matter in Cutoff Field Theory

Including the vacuum effects, the compressional properties of nuclear matter are studied in the cutoff field theory. Under the Hartree approximation, the low-energy effective Lagrangian is derived in the framework of the renormalization group methods. The coefficients are determined in a way where the physical results hardly depend on the value of the cutoff which is conveniently introduced into the theory. It is shown that, to reproduce the empirical data of the nucleus incompressibility, the compressibility of the nuclear matter is favorable to be 250$\sim$350MeV.Comment: PACS numbers, 21.65.+

Assessment of suicide in Japan during the COVID-19 pandemic vs previous years

Importance: There are concerns that suicide rates may have increased during the coronavirus disease 2019 (COVID-19) pandemic. Objective: To assess whether suicide rates in Japan increased in April through November 2020 compared with previous years. Design, Setting, and Participants: This cross-sectional study used national data obtained from the Ministry of Health, Labor and Welfare from 2016 to 2020 on the monthly number of individuals who died of suicide in Japan from January to November of 2016 to 2020. Exposure: 2020 vs previous years. Main Outcomes and Measures: The main outcome was monthly suicide rates, calculated as the number of individuals who died of suicide divided by the total population. A difference-in-difference regression model was used to estimate the change in monthly suicide rates in April to November 2020 vs these months in 2016 to 2019. Results: Analyses included 90 048 individuals (61 366 [68.1%] men) who died of suicide from 2016 to 2020. The difference-in-difference analysis of men showed that there was no increase in suicide rates from April through September 2020 compared with these months in 2016 to 2019, but that suicide rates were increased in October (difference-in-difference, 0.40 [95% CI, 0.14 to 0.67] suicide deaths per 100 000 population) and November (difference-in-difference, 0.34 [95% CI, 0.07 to 0.60] suicide deaths per 100 000 population). Among women, suicide rates in 2020 compared with 2016 to 2019 increased in July (difference-in-difference, 0.24 [95% CI, 0.09 to 0.38] suicide deaths per 100 000 population), August (difference-in-difference, 0.30 [95% CI, 0.16 to 0.45] suicide deaths per 100 000 population), September (difference-in-difference, 0.29 [95% CI, 0.15 to 0.44] suicide deaths per 100 000 population), October (difference-in-difference, 0.62 [95% CI, 0.48 to 0.77] suicide deaths per 100 000 population), and November (difference-in-difference, 0.29 [95% CI, 0.15 to 0.44] suicide deaths per 100 000 population). In secondary analyses in which the suicide rates of 2020 were compared with the expected rates based on trends from 2011 to 2019, the increases in suicide rates were most pronounced among men aged younger than 30 years (eg, November: observed vs expected rate ratio [RR], 1.48 [95% CI, 1.26-1.71]) and women aged younger than 30 years (eg, October: observed vs expected RR, 2.14 [95% CI, 1.76 to 2.52]) and 30 to 49 years (eg, October: observed vs expected RR, 2.30 [95% CI, 2.01 to 2.58]). Conclusions and Relevance: These findings suggest that compared with previous years, suicide rates in Japan in 2020 increased in October and November for men and in July through November for women

Parameter identification in non-isothermal nucleation and growth processes

We study non-isothermal nucleation and growth phase transformations, which are described by a generalized Avrami model for the phase transition coupled with an energy balance to account for recalescence effects. The main novelty of our work is the identification of temperature dependent nucleation rates. We prove that such rates can be uniquely identified from measurements in a subdomain and apply an optimal control approach to develop a numerical strategy for its computation

Characterization of β-N-acetylhexosaminidase (LeHex20A), a member of glycoside hydrolase family 20, from Lentinula edodes shiitake mushroom)

We purified and cloned a β-N-acetylhexosaminidase, LeHex20A, with a molecular mass of 79 kDa from the fruiting body of Lentinula edodes (shiitake mushroom). The gene lehex20a gene had 1,659 nucleotides, encoding 553 amino acid residues. Sequence analysis indicated that LeHex20A belongs to glycoside hydrolase (GH) family 20, and homologues of lehex20a are broadly represented in the genomes of basidiomycetes. Purified LeHex20A hydrolyzed the terminal monosaccharide residues of β-N-acetylgalactosaminides and β-N-acetylglucosaminides, indicating that LeHex20A is a β-N-acetylhexosaminidase classified into EC 3.2.1.52. The maximum LeHex20A activity was observed at pH 4.0 and 50°C. The kinetic constants were estimated using chitooligosaccharides with degree of polymerization 2-6. GH20 β-N-acetylhexosaminidases generally prefer chitobiose among natural substrates. However, LeHex20A had the highest catalytic efficiency (k(cat)/K(m)) for chitotetraose, and the K(m) values for GlcNAc(6) were 3.9-fold lower than for chitobiose. Furthermore, the enzyme partially hydrolyzed amorphous chitin polymers. These results indicate that LeHex20A can produce N-acetylglucosamine from long-chain chitomaterials