High-resolution mapping of heteroduplex DNA formed during UV-induced and spontaneous mitotic recombination events in yeast.

In yeast, DNA breaks are usually repaired by homologous recombination (HR). An early step for HR pathways is formation of a heteroduplex, in which a single-strand from the broken DNA molecule pairs with a strand derived from an intact DNA molecule. If the two strands of DNA are not identical, there will be mismatches within the heteroduplex DNA (hetDNA). In wild-type strains, these mismatches are repaired by the mismatch repair (MMR) system, producing a gene conversion event. In strains lacking MMR, the mismatches persist. Most previous studies involving hetDNA formed during mitotic recombination were restricted to one locus. Below, we present a global mapping of hetDNA formed in the MMR-defective mlh1 strain. We find that many recombination events are associated with repair of double-stranded DNA gaps and/or involve Mlh1-independent mismatch repair. Many of our events are not explicable by the simplest form of the double-strand break repair model of recombination

Impact of intrinsic biophysical diversity on the activity of spiking neurons

We study the effect of intrinsic heterogeneity on the activity of a population of leaky integrate-and-fire neurons. By rescaling the dynamical equation, we derive mathematical relations between multiple neuronal parameters and a fluctuating input noise. To this end, common input to heterogeneous neurons is conceived as an identical noise with neuron-specific mean and variance. As a consequence, the neuronal output rates can differ considerably, and their relative spike timing becomes desynchronized. This theory can quantitatively explain some recent experimental findings.Comment: 4 pages, 5 figure

Investigation of electrical contact resistance for nonconductive film functionalized with Π -conjugated self-assembled molecules

©2007 American Institute of Physics. The electronic version of this article is the complete one and can be found online at: http://link.aip.org/link/?APPLAB/90/092102/1DOI:10.1063/1.2709638Nonconductive adhesive/nonconductive film (NCA/NCF) bonding technology has attracted increasing research interests as lead-free interconnect. During bonding, heat and pressure are applied and the direct physical contacts between the two surfaces of integrated circuit bump and substrate bond pad can be achieved. The electrical contact resistance of a NCA/NCF joint is controlled by the pressure, roughness and NCA/NCF material properties. An accurate prediction of contact resistance can help guide experiment setup towards improving the electrical performance of NCA/NCF. In this study, a model is developed and correlated to experiments. The effects of NCA/NCF material properties on electrical contact resistance are investigated

Interfacial instability-driven amorphization/nanocrystallization in a bulk Ni45Cu5Ti33Zr16Si1 alloy during solidification

We report on experimental evidence for local amorphization/nanocrystallization at the interfaces between the B2-ordered Ni(Ti,Zr) phase and the NiTiZr phase with P63/mmc during solidification of a multicomponent Ni45Cu5Ti33Zr16Si1 alloy. So far there are several well-known mechanisms for interfacial amorphization in the solid state but no interfacial instability-driven amorphization/nanocrystallization during transition from liquid to solid state has been reported to our knowledge. The curvature of the interfacial area of the ordered Ni(Ti,Zr) phase is locally negative accompanying reverse atomic diffusion. This results in the frustration of the strong ordering tendency of the Ni(Ti,Zr) phase, and induces local amorphization/nanocrystallization

Drivers of attitudes towards luxury brands: A cross-national investigation into the roles of interpersonal influence and brand consciousness

Purpose - Limited attention has been paid to the cultural influences on the formation of consumer attitudes toward luxury brands (LUX). The current study investigates this relationship by developing a model that additionally employs the constructs of susceptibility to normative interpersonal influence (SNII) and brand consciousness (BCO). Design/methodology/approach - Sample data were gathered through surveys administered to 383 college students in the United Kingdom (UK) and Taiwan. The model of cultural influences on attitudes toward luxury brands was empirically tested using multi-group structural equation modeling to evaluate its applicability across the two countries. Findings - Results are presented in two parts: 1) the exogenous construct part of the model establishing the reliability and validity of the cultural dimension constructs (horizontal individualism, vertical individualism, horizontal collectivism, and vertical collectivism) that are antecedent to consumer SNII and 2) the endogenous part of the model in which consumer SNII affects LUX through the mediating role of BCO. Research limitations/implications - The findings in the current study are limited to a sample of college students in the UK and Taiwan, which, through representing Western and Asian countries, each housing different cultures, do not span the greater number of cultures found across these countries, much less across the world. Furthermore it is assumed that there are a number of subcultures in both the UK and Taiwan that are not accounted for in this study. Practical implications - An individual level of cultural orientation (e.g. horizontalism and verticalism) rather than traditionally adopted regionally-defined or nationally-based (Hofstede, 1980) cultural criteria should be investigated to identify more accurate market demand patterns in order to best target consumers in these markets (Sharma, 2010). In addition, appealing, vertical ad messages would be more effective in stimulating consumer motivations for consumption of luxury brands. Conversely, horizontal ad messages would be effective in demarketing approaches. Originality/value - The current study is the first of its kind to explore the effect of cultural-orientation on the formation of LUX cross-nationally. As such it provides future cross-cultural researchers with valid and reliable culturally-based constructs that can be used to predict consumer SNII in developing LUX. In addition, establishing the mediating role of BCO in the relationship between SNII and LUX helps marketers better understand the equity of their luxury brands, particularly in Asian countries

Zerumbone-loaded nanostructured lipid carrier induces apoptosis in human colorectal adenocarcinoma (Caco2) cell line

The incorporation of zerumbone (Zer) into nanostructured lipid carrier (NLC) is hypothesized to increase the efficacy of the drug. Nanostructured lipid carrier has sustained-drug release characteristics and is able to improve the solubility and bioavailability of the lipophilic drug. In this study, the anti-cancer effect of Zer was tested on human colorectal adenocarcinoma (Caco-2) cell line. The effect of Zer, zerumbone-loaded nanostructured lipid carrier (Zer-NLC) and NLC on the Caco-2 cell viability were determined using the MTT assay. The treatment concentration ranges from 0 to 120 μM at four different time intervals (i.e., 0 h, 24 hrs, 48 hrs and 72 hrs) were evaluated. At 24 hrs, the half-growth inhibitory concentration (GI50) of Zer-NLC (i.e., 4.25 μM) is lower than that of Zer (i.e., 23.75 μM). However, Zer outperformed the Zer-NLC at the subsequent time points. Similar trend was observed in other parameters including the cytostatic concentration (CC) and half-lethal concentration 50 (LC50). Phase contrast imaging and AO/PI fluorescence staining were performed at the CC and LC50 values. The morphological changes and the apoptosis features could be seen in cells treated with Zer and Zer-NLC while cells treated with NLC showed minor morphological changes. The cells treated with Zer-NLC demonstrated a slightly slower progression of apoptosis, which could be due to the controlled release of Zer from the NLC matrix. It was concluded that the incorporation of Zer into NLC did not compromise the potency and efficacy of the drug

Optical observations of NEA 3200 Phaethon (1983 TB) during the 2017 apparition

The near-Earth asteroid 3200 Phaethon (1983 TB) is an attractive object not only from a scientific viewpoint but also because of JAXA's DESTINY+ target. The rotational lightcurve and spin properties were investigated based on the data obtained in the ground-based observation campaign of Phaethon. We aim to refine the lightcurves and shape model of Phaethon using all available lightcurve datasets obtained via optical observation, as well as our time-series observation data from the 2017 apparition. Using eight 1-2-m telescopes and an optical imager, we acquired the optical lightcurves and derived the spin parameters of Phaethon. We applied the lightcurve inversion method and SAGE algorithm to deduce the convex and non-convex shape model and pole orientations. We analysed the optical lightcurve of Phaethon and derived a synodic and a sidereal rotational period of 3.6039 h, with an axis ratio of a/b = 1.07. The ecliptic longitude (lambda) and latitude (beta) of the pole orientation were determined as (308, -52) and (322, -40) via two independent methods. A non-convex model from the SAGE method, which exhibits a concavity feature, is also presented.Comment: 14 pages, 4 figures, 1 figure in Appendix A. Accepted for publication in Astronomy & Astrophysics (A&A