Heterologous expression and functional analysis of the gene cluster for the biosynthesis of and immunity to the lantibiotic, nukacin ISK-1

Nukacin ISK-1 is a lantibiotic produced by Staphylococcus warneri ISK-1. The gene cluster of nukacin ISK-1 consists of at least nukAMTFEG, ORF1 and ORF7. In this study, we demonstrated the heterologous production of nukacin ISK-1 in Lactococcus lactis by the artificial polycistronic expression of nukAMTFEG-ORF7 under the control of the nisin-controlled expression (NICE) system. Consequently, the recombinant L. lactis showed antimicrobial activity. Mass analysis clarified the presence of nukacin ISK-1 produced in the culture supernatant. These results suggested that the recombinant L. lactis produced nukacin ISK-1 heterologously. Inactivation of nukA, -M or -T resulted in the complete loss of the nukacin ISK-1 production phenotype. This finding suggested that nukAMT are indispensably associated with the biosynthesis of nukacin ISK-1. To our knowledge, this is the first report of the heterologous production of lantibiotic using the NICE system.     

Al-laminated film packaged organic radical battery for high-power applications

A 100-mAh class of aluminum-laminated film packaged organic radical battery with a poly(2,2,6,6-tetramethyl-1-piperidinyloxy-4-yl methacrylate) (PTMA) composite cathode and a graphite anode has been fabricated. Its total weight was 22 g and the thickness was 4.3 mm. Because PTMA comprised only 6.2% of the total cell weight, the energy density was considerably less than that of a lithium ion battery. However, the power density per active material weight was found to be better than that of lithium ion battery. The applications which require high-power capability rather than high-energy density, such as the sub-battery in electronic devices and motor drive assistance in electric vehicles, would be appropriate for organic radical batteries in the future.     

Robotic question support system to reduce hesitation for face-to-face questions in lectures

Encouraging students to actively ask questions during lectures is a formidable challenge that can be addressed through innovative use of information technology. We developed a robotic system that allows students in a lecture to collaboratively decide questions to be asked by a humanoid robot. To verify whether the system reduces hesitation to ask questions during lectures, 62 university students were divided into two groups, and each attended two different mock lectures on the Nobel Prize in Physics. Two lectures were conducted with and without the proposed system in counterbalanced order. Results suggested that students who were usually hesitant to ask questions during lectures became less hesitant to ask questions face-to-face when they could use the proposed system. Moreover, the perceived activeness in the lectures increased when using the system. Multiple regression analyses revealed that certain student actions, particularly tweeting and showing agreement with the questions posted by others, were correlated with an increase in perceived activeness.     

Diffusion of m-sulfobenzoic acid in nylon 6

Diffusion of m-sulfobenzoic acid in nylon 6 was measured by using the S-35 labelled acid as a tracer. A multimodal mechanism, identical to that in a preceding paper on sorption, was assumed, according to which the protonated acid diffused by dissolution, and the two dissociated acids diffused by competitive interaction with the charged sites in nylon 6. The concentration dependence of the diffusion coefficients was explained by the chemical potential gradient model. The monobasically dissociated species was found to be dominant in the diffusion process. Diffusion coefficients and the activation energies of diffusion did not vary significantly with pH.     

Carboxyl-containing polyesters and polyurethanes from dibenzyl L-tartrate

We have prepared polyesters from succinyl chloride, adipoly chloride, and telephthaloyl chloride with dibenzyl L -tartrate, polyurethanes from hexamethylene diisocyanate, tolune 2,4-diisocyanate, and methylene-bis(4-phenyl isocyanate) with dibenzyl L -tartrate. The molecular weights of these polymers were generally low except for one of the polyurethanes. These polymers were reduced to give those having carboxyl side groups. Potency for inducing interferon was tested for one of the polymers. The result was not encouraging in showing low activity.     

No mobile,no life: Self-perception and text-message dependency among Japanese high school students

A survey was conducted to investigate how self-perception of text-message dependency leads to psychological/behavioral symptoms in relation to personality factors. Japanese high school students completed a self-report questionnaire measuring frequency of text-messages, self-perception of text-message dependency, psychological/behavioral symptoms, extroversion and neuroticism. Self-perception of text-message dependency was composed of three factors: perception of excessive use, emotional reaction, and relationship maintenance. Although message frequency was significantly related to psychological/behavioral symptoms, this effect was qualified by self-perception and personality factors. In particular, self-perception of text-message dependency strongly affected psychological/behavioral symptoms. Importance of distinction between extroverted and neurotic text-message dependency through the process of self-perception of maladaptive behavior is discussed.