Gold nanodecahedra (pentagonal bipyramids) exhibit striking optical properties spanning the visible and near-IR spectral regions, which together with a high electric-field enhancement at their tips, makes them very promising materials for sensing-related applications. The effective design of biosensors based on these nanocrystals requires a detailed investigation and understanding of their surface plasmon resonances. For that purpose, we have used correlated electron microscopy imaging and optical dark-field spectroscopy on individual decahedra to investigate their size and orientation-dependent optical properties at the single particle level. We have also investigated the effects of tip truncation and local refractive index changes on single particle plasmon resonances. The experimental results are supported by theoretical modeling based on a fully 3D, boundary element method (BEM-3D).
Blockchain technology is a growing digital technology and provides competitive advantage for the food industry. The aim of this conceptual and empirical study is to identify the key indicators for creating a sustainable competitive advantage in the food industry based on Blockchain technology through investigating the literature. Then, using Delphi method, the importance of each indicator is determined based on the experts' opinions. For this purpose, about 2346 online questionnaires were sent to university professors and experts in the field of blockchain. About 36 people responded to the online email and responded to the questionnaire completely. The research findings indicate that the indicators of permanent storage of information, supply chain coordination, improved performance appraisal, simplification of international transactions, traceability and fraud prevention are the top five indicators, respectively. This research helps the decision makers in the food industry to achieve a sustainable competitive advantage compared to their competitors in the market by using blockchain technology.
Abstract Mutation, genetic drift, and selection are considered the main factors shaping genetic variation in nature. There is a lack, however, of general predictions accounting for the mutual interrelation between these factors. In the context of the background selection model, we provide a set of equations for the joint prediction of the effective population size and the rate of fixation of deleterious mutations, which are applicable both to sexual and asexual species. For a population of N haploid individuals and a model of deleterious mutations with effect s appearing with rate U in a genome L Morgans long, the asymptotic effective population size (Ne) and the average number of generations (T) between consecutive fixations can be approximated by Ne≈N exp [−2U/(2s +L) (1−1/UT)3] and T≈[exp(2sNe) −1]/[2UsNe]. The solution is applicable to Muller’s ratchet, providing satisfactory approximations to the rate of accumulation of mutations for a wide range of parameters. We also obtain predictions of the effective size accounting for the expected nucleotide diversity. Predictions for sexual populations allow for outlining the general conditions where mutational meltdown occurs. The equations can be extended to any distribution of mutational effects and the consideration of hotspots of recombination, showing that Ne is rather insensitive and not proportional to changes in N for many combinations of parameters. This could contribute to explain the observed small differences in levels of polymorphism between species with very different census sizes.
In our diets, many of the consumed foods are subjected to various forms of heating and thermal processing. Besides enhancing the taste, texture, and aroma of the foods, heating helps to sterilize and facilitate food storage. On the other hand, heating and thermal processing are frequently reported during the preparation of various traditional herbal medicines. In this review, we intend to highlight works by various research groups which reported on changes in phytochemicals and bioactivities, following thermal processing of selected plant-derived foods and herbal medicines. Relevant cases from plant-derived foods (garlic, coffee, cocoa, barley) and traditional herbal medicines (Panax ginseng, Polygonum multiforum, Aconitum carmichaelii Debeaux, Angelica sinensis Radix) will be presented in this review. Additionally, related works using pure phytochemical compounds will also be highlighted. In some of these cases, the amazing formation of new compounds were being reported. Maillard reaction could be concluded as the predominant pathway leading to the formation of new conjugates, along with other possibilities being suggested (degradation, transglycosylation, deglycosylation and dehydration). With collective efforts from all researchers, it is hoped that more details will be revealed and lead to the possible discovery of new, heat-mediated phytochemical conjugates.
After analyzing the base composition asymmetry of coding regions in vertebrate mitochondria, we identified 2 fishes, Albula glossodonta and Bathygadus antrodes, with inverted compositional patterns. Both species appear to have an unusual control region (CR), and in B. antrodes, it has switched from the light strand to the heavy strand. To our knowledge, this is the first report in vertebrates of inverted mitochondrial replication, caused by an inversion of the CR. These findings support the strand-asymmetric model of mtDNA replication and suggest that vertebrate mtDNA can tolerate globally reversed mutational pressures. In addition, we propose that nucleotide bias is not strand specific but that it depends on the location of the CR.
