High-Precision Spectroscopy with Counter-Propagating Femtosecond Pulses

An experimental realization of high-precision direct frequency comb spectroscopy using counter-propagating femtosecond pulses on two-photon atomic transitions is presented. Doppler broadened background signal, hampering precision spectroscopy with ultrashort pulses, is effectively eliminated with a simple pulse shaping method. As a result, all four 5S-7S two-photon transitions in a rubidium vapor are determined with both statistical and systematic uncertainties below 10$^{-11}$, which is an order of magnitude better than previous experiments on these transitions.Comment: 5 pages, 4 figures. Accepted to PR

The evolutionary role of human-specific genomic events

In the short evolutionary time since the human-chimpanzee divergence, approximately 6.6 million years ago, humans have acquired a range of traits that are unique among primates. These include tripling brain size, enhanced cognitive abilities, complex culture, descended larynx structure that enables spoken language, longevity, specific diseases, inferior olfaction, and (in some human populations) adult lactase persistence. These traits were likely to have evolved through various genomic mechanisms, among them gene duplications and gene-culture co-evolution. Several studies have estimated the dates for some of these human lineage genomic events. However, no study to date has performed a genomewide estimate of the dates of all human gene duplications. Moreover, as many of these traits were likely to have evolved via gene-culture coevolutionary mechanisms, investigating the evolution of one of these human-specific traits – lactase persistence – provides a model example for in-depth future investigations of specific human phenotypes. In this study I have investigated an important class of human-specific genomic events – gene duplications (otherwise known as human inparalogues). I have developed a new bioinformatics approach for detecting human lineage-specific inparalogues and the duplication dates for those genes. I show that human-specific inparalogues are non-randomly distributed among biological function classes, and their duplication event dates are non-randomly distributed on a timeline between the date of the human-chimpanzee split and the present. I have also investigated the evolution of the human-specific polymorphic trait – lactase persistence. I have performed a worldwide correlation analysis comparing frequency data on all currently known lactase persistence-associated alleles and the distribution of the lactase persistence phenotype in different human populations. I have also performed a gene-culture co-evolution analysis, employing spatially explicit simulation and Approximate Bayesian Computation to condition simulations on genetic and archaeological data, in order to make inferences on the evolution of lactase persistence and dairying in Europe

A worldwide correlation of lactase persistence phenotype and genotypes

Background: The ability of adult humans to digest the milk sugar lactose - lactase persistence - is a dominant Mendelian trait that has been a subject of extensive genetic, medical and evolutionary research. Lactase persistence is common in people of European ancestry as well as some African, Middle Eastern and Southern Asian groups, but is rare or absent elsewhere in the world. The recent identification of independent nucleotide changes that are strongly associated with lactase persistence in different populations worldwide has led to the possibility of genetic tests for the trait. However, it is highly unlikely that all lactase persistence-associated variants are known. Using an extensive database of lactase persistence phenotype frequencies, together with information on how those data were collected and data on the frequencies of lactase persistence variants, we present a global summary of the extent to which current genetic knowledge can explain lactase persistence phenotype frequency. Results: We used surface interpolation of Old World lactase persistence genotype and phenotype frequency estimates obtained from all available literature and perform a comparison between predicted and observed trait frequencies in continuous space. By accommodating additional data on sample numbers and known false negative and false positive rates for the various lactase persistence phenotype tests (blood glucose and breath hydrogen), we also apply a Monte Carlo method to estimate the probability that known lactase persistence-associated allele frequencies can explain observed trait frequencies in different regions. Conclusion: Lactase persistence genotype data is currently insufficient to explain lactase persistence phenotype frequency in much of western and southern Africa, southeastern Europe, the Middle East and parts of central and southern Asia. We suggest that further studies of genetic variation in these regions should reveal additional nucleotide variants that are associated with lactase persistence

DOES CORPORATE GOVERNANCE INFLUENCE VALUE CREATION : ASSESSING THE MEDIATING ROLE OF CSR AND TAX AVOIDANCE

This study aims to investigate the influence of CG on value creation both directly and as a mediating role in the form of tax avoidance and CSR. The panel data approach was employed, using a sample of 32 multisectoral companies, excluding those in the financial sector, that are listed in the Indonesia Stock Exchange from 2016 to 2019. The data is analyzed using the Smart PLS. In this study, value creation was measured using Tobin’s Q  and CG was measured using the Corporate Governance Index (CGI); while the mediating variable, in the form of tax avoidance, was measured using the Henry Sansing formula, and CSR was measured using the GRI-G4 index. The result showed that corporate governance has a direct significant impact on value creation. Furthermore, it is found that CSR tax avoidance could not mediate the relationship between CG and value creation. 

The impact of cash flow statement on firm value in indonesia

This study aimed to determine the impact of cash flow statement on firm value in Indonesia companies that listed on the Indonesia Stock Exchange. The total data used as the sample was 1,236 data including all sectors except financial sectors for the period 2015 to 2019. The fixed effect model was chosen as the best model to analyze panel data. Furthermore, Eviews 10 application was also to help the process of regression. The results of this study showed that the operating cash flow ratio had a positive significant effect on firm value. Meanwhile, the investing cash flow ratio and financing cash flow ratio had a negative significant effect on firm value. In addition, the results also indicated that operating dummy and investing dummy had no effect on firm value. Besides, the financing dummy was the same as financing cash flow ratio that significantly affected the firm value. Furthermore, both managers’ holding ratio and board size revealed a significant relationship to the firm value, while the independent director dummy showed a positive significant effect on firm value

Semiconservative quasispecies equations for polysomic genomes: The general case

This paper develops a formulation of the quasispecies equations appropriate for polysomic, semiconservatively replicating genomes. This paper is an extension of previous work on the subject, which considered the case of haploid genomes. Here, we develop a more general formulation of the quasispecies equations that is applicable to diploid and even polyploid genomes. Interestingly, with an appropriate classification of population fractions, we obtain a system of equations that is formally identical to the haploid case. As with the work for haploid genomes, we consider both random and immortal DNA strand chromosome segregation mechanisms. However, in contrast to the haploid case, we have found that an analytical solution for the mean fitness is considerably more difficult to obtain for the polyploid case. Accordingly, whereas for the haploid case we obtained expressions for the mean fitness for the case of an analogue of the single-fitness-peak landscape for arbitrary lesion repair probabilities (thereby allowing for non-complementary genomes), here we solve for the mean fitness for the restricted case of perfect lesion repair.Comment: 16 pages, 3 figure

An In-Depth Study of Multimedia Elements for Programme Production in Television Stations in Lagos State, Nigeria

Multimedia refers to access of information by a variety of display media elements: text, graphics (vector), images (bitmap), audio (sound), motion pictures (animation) and video. They are weaved into a computer based presentation or TV programmes. Multimedia graphics has played a significant role in design and visual communication; while television is a medium for accessing those designs for disseminating information. Multimedia elements are experienced in day to day activities and also have a critical impact in television programming. This paper therefore aims to examine multimedia elements and its features for the production of programmes in television stations. The area of study is Lagos State, Nigeria. A concise survey was carried out in the study area which uncovers the problems of multimedia production for television; hence, adequate measures to resolve the challenges were proposed. Keywords: Multimedia Content, Media Elements, Linear Mode, Programmes, Visuals DOI: 10.7176/ADS/71-05 Publication date:March 31st 201