Tuesday, 3 January 2017

Mathematica and LaTeX Integration

This document is about Mathex, a software package that allows embedding Mathematica macro expressions into a Latex document, combining together the power of the two systems. 

computational mathematics journal
It works in this way: when you click F2 on your preferred editor, before of the TeX to PDF conversion, a pre-processor (written in the PERL language) call Mathematica, do the computation globally (i.e. treating the file as a single program) and replaces the macros in the final TeX. The macros should be inserted between the two conventional symbols <% ... %>, and can contain every valid Mathematica’s expression, or more expressions, separated by semicolon. As every expression and every graphics object get created every time on-the-fly, the process can be slow.

Monday, 2 January 2017

Using Ancestral Information to Inform Analyses of Complex Data Sets

Over the last decade, improvements in sequencing technologies coupled with active development of association mapping methods have made it possible to link genotypes and quantitative traits in humans. Despite substantial progress in the ability to generate and analyze large data sets, however, genotype-phenotype associations are often difficult to find, even in studies with large numbers of individuals and genetic markers. This is due, in part, to the fact that effects of individual loci can be small and/or dependent on genetic variation at other loci or the environment. 

biometrics journal articles
Tree-based mapping, which uses the evolutionary relatedness of sampled individuals to gain information during association mapping, has the potential to significantly improve our ability to detect loci impacting human traits. However, current tree-based methods are too computationally intensive and inflexible to be of practical use. Here, we compare tree-based methods with more classical approaches for association mapping and discuss how the limitations of these newer methods might be addressed. Ultimately, these advances have the potential to advance our understanding of the molecular mechanisms underlying complex diseases.

Friday, 30 December 2016

Nitrogen Dispersion

A mathematical model of free surface is presented for the study of the nitrogen injection of the gas cap for maintain of pressure, we used one model dispersion a flow in well zone. Nitrogen injected into the cap has a density greater than the original gas which has rushed to the gas-oil contact goc. Since the goc on the border there is a lot of nitrogen gas, it will spread and disperse into the oil. 

physical mathematics journal
In the goc around a well about to be invaded by gas coning phenomena occur; therefore the model to interpret the output of the well must include the phenomenon of free surface. This paper proposes a method to measure the degree of contamination of the oil zone. This compositional data based on a production well before being invaded in producing interval by the gas cap. The most contaminated area of oil is close to the goc, as nitrogen is expected to exit the current production from the well just before being overcome by gas.

Thursday, 29 December 2016

A Meeting of Great Minds, Sophus Lie and John Nash throughout their Works

It is well known that Marius Sophus Lie (1842-1899) and John Forbes Nash (1928-2015) are great mathematicians. Sophus Lie comes from Norway and John Nash from United States of America. Their stories have certain resemblances and remarkable relations. This editorial would emphasize some of them. When they have started their university studies, their respective first interests were not mathematics.

journal lie theory impact factor
That is to say, Lie has been in Astronomy and Nash in Chemical Engineering. Whereas,when they worked on mathematics, the first had Lobatchevski award in 1897 and the second, Nobel prize 1994 and Abel award 2015 (Niels Abel is the uncle of the wife of Sophus Lie: Anna Birch). In addition, their contributions in geometry are considerable, particularly in differential equations. Lie worked on transformation groups relative to partial differential equations, in other words, on Lie groups and on special non-associative algebras named Lie algebras.

Wednesday, 28 December 2016

Advances in Logic, Operations and Computational Mathematics

Journal of Applied & Computational Mathematics Volume 5, Issue 2 comprised of 7 research articles and 4 opinion articles and is focused on the innovation of polygon, Euler, linear and non-linear equations.

computational applied mathematics impact factor
EL-Kholy et al., in their research article discussed about balanced folding over a polygon and Euler numbers. The study proved that for a balanced folding of a simply connected surface M, there is a subgroup of the group which is called all homeomorphisms of M that will acts 1- transitively on the 2-cells of M.

Gil et al., in their research have reported about the exponentially stabile non-linear, non-autonomous multi variable discrete systems. Based on the recent estimates on matrix equations, the findings suggest that a class of non-autonomous discrete-time systems is governed by semi-linear vector difference equations along with slowly varying linear parts.

Monday, 26 December 2016

Models of damped oscillators in quantum mechanics

We consider several models of the damped oscillators in nonrelativistic quantum mechanics in a framework of a general approach to the dynamics of the time-dependent Schr¨odinger equation with variable quadratic Hamiltonians. The Green functions are explicitly found in terms of elementary functions and the corresponding gauge transformations are discussed. 

physical mathematics journal
The factorization technique is applied to the case of a shifted harmonic oscillator. The time evolution of the expectation values of the energy-related operators is determined for two models of the quantum damped oscillators under consideration. The classical equations of motion for the damped oscillations are derived for the corresponding expectation values of the position operator.

Friday, 2 December 2016

On the Use of P-Values in Genome Wide Disease Association Mapping

In hypothesis testing, p-value is routinely used as a measure of statistical evidence against the null hypothesis, where a smaller p-value indicates stronger evidence substantiating the alternative hypothesis. P-value is the probability of type-I error made in a hypothesis testing, namely, the chance that one falsely reject the null hypothesis when the null holds true. In a disease genome wide association study (GWAS), p-value potentially tells us how likely a putative disease associated variant is due to random chance. For a long time p-values have been taken seriously by the GWAS community as a safeguard against false positives. 

genome research impact factor
Every disease-associated mutation reported in a GWAS must reach a stringent p-value cut off (e.g., 10-8) in order to survive the multiple testing corrections. This is reasonable because after testing millions of variants in the genome, some random variants ought to yield small p-values purely by chance. Despite of p-value’s theoretical justification, however, it has become increasingly evident that statistical p-values are not nearly as reliable as it was believed.