Non-extensive Trends in the Size Distribution of Coding and Non-coding DNA Sequences in the Human Genome

We study the primary DNA structure of four of the most completely sequenced human chromosomes (including chromosome 19 which is the most dense in coding), using Non-extensive Statistics. We show that the exponents governing the decay of the coding size distributions vary between $5.2 \le r \le 5.7$ for the short scales and $1.45 \le q \le 1.50$ for the large scales. On the contrary, the exponents governing the decay of the non-coding size distributions in these four chromosomes, take the values $2.4 \le r \le 3.2$ for the short scales and $1.50 \le q \le 1.72$ for the large scales. This quantitative difference, in particular in the tail exponent $q$, indicates that the non-coding (coding) size distributions have long (short) range correlations. This non-trivial difference in the DNA statistics is attributed to the non-conservative (conservative) evolution dynamics acting on the non-coding (coding) DNA sequences.Comment: 13 pages, 10 figures, 2 table

Second Life as a Learning and Teaching Environment for Digital Games Education

Previous studies show that online virtual worlds can contribute to the social aspects of distance learning, improve student engagement, and enhance students’ experience as a whole [4]; [3]. This paper reviews previous research of using online virtual worlds in teaching and learning, compares Second Life with traditional classroom sessions and the Blackboard, and discusses the benefits and problems of using virtual environments in the post-sixteen education and how they affect students’ learning. It also reports a study of using Second Life as an educational environment for teaching games design at undergraduate level, and investigates the impacts and implications of online virtual environments on learning and teaching processes and their application to digital games education. The sample was 27 first year students of the Computer Games Modelling and Animation course. Students’ views on using Second Life for learning and teaching were collected through a feedback questionnaire. The results suggest that virtual learning environments like Second Life can be exploited as a motivational learning tool. However, problems such as identify issues and lacking of role markers may change student behaviour in virtual classroom. We discuss this phenomenon and suggest ways to avoid it in the preparation stage

Bounce Loop Quantum Cosmology Corrected Gauss-Bonnet Gravity

We develop a Gauss-Bonnet extension of Loop Quantum Cosmology, by introducing holonomy corrections in modified $F(\mathcal{G})$ theories of gravity. Within the context of our formalism, we provide a perturbative expansion in the critical density, a parameter characteristic of Loop Quantum Gravity theories, and we result in having leading order corrections to the classical $F(\mathcal{G})$ theories of gravity. After extensively discussing the formalism, we present a reconstruction method that makes possible to find the Loop Quantum Cosmology corrected $F(\mathcal{G})$ theory that can realize various cosmological scenarios. Specifically, we studied exponential and power-law bouncing cosmologies, emphasizing on the behavior near the bouncing point and in some cases, the behavior for all the values of the cosmic time is obtained. We exemplify our theoretical constructions by using bouncing cosmologies, and we investigate which Loop Quantum Cosmology corrected Gauss-Bonnet modified gravities can successfully realize such cosmologies.Comment: Revised version, to appear in PR

Power law exponents characterizing human DNA

The size distributions of all known coding and noncoding DNA sequences are studied in all human chromosomes. In a unified approach, both introns and intergenic regions are treated as noncoding regions. The distributions of noncoding segments Pnc S of size S present long tails Pnc S S−1− nc, with exponents nc ranging between 0.71 for chromosome 13 and 1.2 for chromosome 19 . On the contrary, the exponential, short-range decay terms dominate in the distributions of coding exon segments Pc S in all chromosomes. Aiming to address the emergence of these statistical features, minimal, stochastic, mean-field models are proposed, based on randomly aggregating DNA strings with duplication, influx and outflux of genomic segments. These minimal models produce both the short-range statistics in the coding and the observed power law and fractal statistics in the noncoding DNA. The minimal models also demonstrate that although the two systems coding and noncoding coexist, alternating on the same linear chain, they act independently: the coding as a closed, equilibrium system and the noncoding as an open, out-of-equilibrium on

Colitis Following Initiation of Sofosbuvir and Simeprevir for Genotype 1 Hepatitis C.

Sofosbuvir and simeprevir are used for the treatment of chronic hepatitis C (HCV) genotype 1. Both drugs have been well-tolerated, with diarrhea noted in 6% cases with sofosbuvir, 16% with sofosbuvir plus simeprevir, and 0% with simeprevir. No prior reports exist of colitis secondary to either drug or their combination. We report a patient with no prior history of inflammatory bowel disease who developed significant bloody diarrhea within 2 weeks of sofosbuvir/simeprevir initiation. Colonoscopy and biopsy confirmed pancolitis, which responded to mesalamine and completion of sofosbuvir/simeprevir

On Casimir Pistons

In this paper we study the Casimir force for a piston configuration in $R^3$ with one dimension being slightly curved and the other two infinite. We work for two different cases with this setup. In the first, the piston is "free to move" along a transverse dimension to the curved one and in the other case the piston "moves" along the curved one. We find that the Casimir force has opposite signs in the two cases. We also use a semi-analytic method to study the Casimir energy and force. In addition we discuss some topics for the aforementioned piston configuration in $R^3$ and for possible modifications from extra dimensional manifolds.Comment: 20 pages, To be published in MPL

An early Byzantine glass workshop at Argyroupolis, Crete: Insights into complex glass supply networks

Archaeometric studies on early Byzantine glass excavated in Greece are extremely scarce in the literature and almost exclusively related to small groups of samples, mainly glass tesserae. The aim of this study is to present archaeometric data of a large assemblage of early Byzantine glass excavated in ancient Lappa, modern town of Argyroupolis, SW of Rethymno in Crete. A series of salvage excavations unearthed a complex of 5 rooms, identified as a secondary glass workshop, yielding more than 1500 glass fragments of objects (mainly rims and stems of glass goblets) and glass working debris (mainly test drops, chunks etc.). The glass and the architectural remains date to the 4th to 7th c. AD. The glass is a typical soda lime silica glass, with close similarities between the chemical composition of the glass working debris and the objects found in the complex. The glass working debris can be divided in three main compositional groups, including the two well-known mineral-natron based groups Levantine I and Foy Série 2.1. The third compositional group of samples identified in the assemblage has a strong plant ash signature. This group, similar to one previously identified in Egypt, has been noticed here for the first time outside Egypt. There are only a few examples of Foy Série 3.2, a composition that circulated widely in the Mediterranean during the early Byzantine period. This differentiation into four compositional groups can be also broadly linked to object types, while the glass working debris covers all compositional groups