1,680 research outputs found
On a generalization of restricted sum formula for multiple zeta values and finite multiple zeta values
We prove a new linear relation for multiple zeta values. This is a natural
generalization of the restricted sum formula proved by Eie, Liaw and Ong. We
also present an analogous result for finite multiple zeta values
Dynamic Analysis of Product Lifecycle and Sea/Air Modal Choice: Evidence of Export from Japan1
AbstractHere, we test the hypothesis that commodities at their peak valuation are transported by air, while those at their inception and maturity are shipped by sea, as well as the theory that shippers choose air to transport high-valued commodities. We empirically investigated how the product lifecycle of commodities is reflected by shippers’ choices of air over seaborne transportation. We also assumed that commodities that achieved substantial innovation in their lifecycles would be moved by air transportation so that these commodities could reach targeted markets as quickly as possible to avoid the opportunity costs that might be generated by missed business chances. We constructed two sets of unbalanced panel data of 14 commodities for 24 years drawn from Japan's customs, demographic, and international statistics. By estimating structural equation systems that consisted of commodity-specific export and export air ratio functions, we found that the product lifecycle of cargo outgoing from Japan exactly matched the upward and downward movement of the air ratio
A cyclic analogue of multiple zeta values
We consider a cyclic analogue of multiple zeta values (CMZVs), which has two
kinds of expressions; series and integral expression. We prove an
`integralseries' type identity for CMZVs. By using this identity, we
construct two classes of -linear relations among CMZVs. One of them
is a generalization of the cyclic sum formula for multiple zeta-star values. We
also give an alternative proof of the derivation relation for multiple zeta
values
pruR and PA0065 Genes Are Responsible for Decreasing Antibiotic Tolerance by Autoinducer Analog-1 (AIA-1) in Pseudomonas aeruginosa
Pseudomonas aeruginosa infection is considered a high-risk nosocomial infection and is very difficult to eradicate because of its tolerance to antibiotic treatment. A new compound, autoinducer analog-1 (AIA-1), has been demonstrated to reduce antibiotic tolerance, but its mechanisms remain unknown. This study aimed to investigate the mechanisms of AIA-1 in the antibiotic tolerance of P. aeruginosa. A transposon mutant library was constructed using miniTn5pro, and screening was performed to isolate high tolerant mutants upon exposure to biapenem and AIA-1. We constructed a deletion mutant and complementation strain of the genes detected in transposon insertion site determination, pruR and PA0066-65-64, and performed killing assays with antibiotics and AIA-1. Gene expression upon exposure to biapenem and AIA-1 and their relationship to stress response genes were analyzed. High antibiotic tolerance was observed in Tn5-pruR and Tn5-PA0065 transposon mutants and their deletion mutants, ΔpruR and ΔPA0066-65-64. Complemented strains of pruR and PA0066-65-64 with their respective deletion mutants exhibited suppressed antibiotic tolerance. It was determined that deletion of PA0066-65-64 increased rpoS expression, and PA0066-65-64 affects antibiotic tolerance via the rpoS pathway. Additionally, antibiotics and AIA-1 were found to inhibit pruR and PA0066-65-64. This study proposed that pruR and PA0066-65-64 are members of the antibiotic tolerance suppressors
Palladium-catalyzed amination of aryl sulfides with anilines.
A combination of a palladium-NHC catalyst and potassium hexamethyldisilazide enables the amination of aryl sulfides with anilines to afford a wide variety of diarylamines. The reaction conditions are versatile enough for the reaction of even bulky ortho-substituted aryl sulfides. This amination can be applied to the modular synthesis of N-aryl carbazoles from the corresponding ortho-bromothioanisoles. As aryl sulfoxides undergo extended Pummerer reactions to afford ortho-substituted aryl sulfides, the Pummerer products are thus useful substrates for the amination to culminate in efficient syntheses of a 2-anilinobenzothiophene and an indole as proof-of-principle of the utility of the extended Pummerer reaction/amination cascade
Bayesian inference to identify crystalline structures for XRD
Crystalline phase structure is essential for understanding the performance
and properties of a material. Therefore, this study identified and quantified
the crystalline phase structure of a sample based on the diffraction pattern
observed when the crystalline sample was irradiated with electromagnetic waves
such as X-rays. Conventional analysis necessitates experienced and
knowledgeable researchers to shorten the list from many candidate crystalline
phase structures. However, the Conventional diffraction pattern analysis is
highly analyst-dependent and not objective. Additionally, there is no
established method for discussing the confidence intervals of the analysis
results. Thus, this study aimed to establish a method for automatically
inferring crystalline phase structures from diffraction patterns using Bayesian
inference. Our method successfully identified true crystalline phase structures
with a high probability from 50 candidate crystalline phase structures.
Further, the mixing ratios of selected crystalline phase structures were
estimated with a high degree of accuracy. This study provided reasonable
results for well-crystallized samples that clearly identified the crystalline
phase structures
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