On the Hyperbolicity of Lorenz Renormalization

We consider infinitely renormalizable Lorenz maps with real critical exponent $\alpha>1$ and combinatorial type which is monotone and satisfies a long return condition. For these combinatorial types we prove the existence of periodic points of the renormalization operator, and that each map in the limit set of renormalization has an associated unstable manifold. An unstable manifold defines a family of Lorenz maps and we prove that each infinitely renormalizable combinatorial type (satisfying the above conditions) has a unique representative within such a family. We also prove that each infinitely renormalizable map has no wandering intervals and that the closure of the forward orbits of its critical values is a Cantor attractor of measure zero.Comment: 63 pages; 10 figure

Analysis of Human Accelerated DNA Regions Using Archaic Hominin Genomes

Several previous comparisons of the human genome with other primate and vertebrate genomes identified genomic regions that are highly conserved in vertebrate evolution but fast-evolving on the human lineage. These human accelerated regions (HARs) may be regions of past adaptive evolution in humans. Alternatively, they may be the result of non-adaptive processes, such as biased gene conversion. We captured and sequenced DNA from a collection of previously published HARs using DNA from an Iberian Neandertal. Combining these new data with shotgun sequence from the Neandertal and Denisova draft genomes, we determine at least one archaic hominin allele for 84% of all positions within HARs. We find that 8% of HAR substitutions are not observed in the archaic hominins and are thus recent in the sense that the derived allele had not come to fixation in the common ancestor of modern humans and archaic hominins. Further, we find that recent substitutions in HARs tend to have come to fixation faster than substitutions elsewhere in the genome and that substitutions in HARs tend to cluster in time, consistent with an episodic rather than a clock-like process underlying HAR evolution. Our catalog of sequence changes in HARs will help prioritize them for functional studies of genomic elements potentially responsible for modern human adaptations

Similarity in Recombination Rate Estimates Highly Correlates with Genetic Differentiation in Humans

Recombination varies greatly among species, as illustrated by the poor conservation of the recombination landscape between humans and chimpanzees. Thus, shorter evolutionary time frames are needed to understand the evolution of recombination. Here, we analyze its recent evolution in humans. We calculated the recombination rates between adjacent pairs of 636,933 common single-nucleotide polymorphism loci in 28 worldwide human populations and analyzed them in relation to genetic distances between populations. We found a strong and highly significant correlation between similarity in the recombination rates corrected for effective population size and genetic differentiation between populations. This correlation is observed at the genome-wide level, but also for each chromosome and when genetic distances and recombination similarities are calculated independently from different parts of the genome. Moreover, and more relevant, this relationship is robustly maintained when considering presence/absence of recombination hotspots. Simulations show that this correlation cannot be explained by biases in the inference of recombination rates caused by haplotype sharing among similar populations. This result indicates a rapid pace of evolution of recombination, within the time span of differentiation of modern humans

A Formal Ontology for Describing Interactive Behaviors and Supporting Automated Testing on User Interfaces

International audienceNowadays many software development frameworks implement Behavior-Driven Development (BDD) as a mean of automating the test of interactive systems under construction. Automated testing helps to simulate user’s actions on the User Interface and therefore check if the system behaves properly and in accordance to scenarios that describe functional requirements. However, tools supporting BDD run tests on implemented User Interfaces and are a suitable alternative for assessing functional requirements in later phases of the development process. However, even when BDD tests can be written in early phases of the development process they can hardly be used with specifications of User Interfaces such as prototypes. To address this problem, this paper proposes to raise the abstraction level of both system interactive behaviors and User Interfaces by means of a formal ontology that is aimed at supporting test automation using BDD. The paper presents an ontology and an ontology-based approach for automating the test of functional requirements of interactive systems. We demonstrate the feasibility of this ontology-based approach to assess functional requirements in prototypes and full-fledge applications through an illustrative case study of e-commerce applications for buying flight tickets

Identification of UX dimensions for incident reporting systems with mobile applications in urban contexts: a longitudinal study

International audienceIncident reporting systems enable end-users to report problems that they have experienced in their working activities to authorities. Such applications are sought to sense the quality of the environment, thus enabling authorities to promote safety and well-being among citizens. Many governments are now promoting the use of mobile applications allowing citizens to report incidents in their neighbourhood to the administration. Nonetheless, it is not clear which user experience dimensions affect the adoption of incident reporting systems, and to what extent anticipated use of the system (anticipated UX) is a determinant for predicting the user experience with the final application. In order to understand how citizens perceive incident reporting systems and which factors affect the user experience (UX), we have performed empirical studies including interviews in early phases of the development process and empirical user testing of advanced prototypes. In this paper, we present the results of a longitudinal study on the evolution of the perception of UX dimensions along the development process, from interviews to running prototypes. Hereafter, we describe the method that has been used for coding the findings of these empirical studies according to six UX dimensions (including visual and aesthetic experience, emotions, stimulation, identification, meaning & value and social relatedness/co-experience). Moreover, we describe how the findings have been associated with users' tasks. The findings from interviews and user testing indicate that whilst the perceived importance of some UX dimensions (such as identification and meaning & value) remains similar over time, other dimensions such as stimulation and emotions do evolve. Beyond the practical implications of this study for the design of incident reporting systems, this work presents an approach that allows comparing the results of UX assessments in different phases of the process

Mass and Lifetime Measurements in Storage Rings

Masses of nuclides covering a large area of the chart of nuclides can be measured in storage rings where many ions circulate at the same time. In this paper the recent progress in the analysis of Schottky mass spectrometry data is presented as well as the technical improvements leading to higher accuracy for isochronous mass measurements with a time\u2010of\u2010flight detector. The high sensitivity of the Schottky method down to single ions allows to measure lifetimes of nuclides by observing mother and daughter nucleus simultaneously. In this way we investigated the decay of bare and H\u2010like 140Pr. As we could show the lifetime can be even shortened compared to those of atomic nuclei despite of a lower number of electrons available for internal conversion or electron capture. All these techniques will be implemented with further improvements at the storage rings of the new FAIR facility at GSI in the future

Present and future experiments with stored exotic nuclei at the FRS-ESR facility

High accuracy mass and lifetime measurements are performed with the combination of the in-flight separator FRS and the cooler-storage ring ESR at GSI. Exotic nuclei are produced via projectile fragmentation and fission at (400\u2013900) MeV/u. This energy range is the basis for unique experimental conditions with bare and few-electron fragments and allows for the first time investigations for decay channels which are rare or strictly forbidden in neutral atoms. New experimental developments and data including the discovery of new isotopes are presented. The comparison of the experimental results with theoretical predictions indicates the potential for improvements of nuclear models. A new generation of experiments will be possible with the advent of the proposed international Facility for Antiproton and Ion Research (FAIR)

Status of the experimental program on mass measurements of stored exotic nuclei at the FRS-ESR facility

Schottky Mass Spectrometry (SMS) and Isochronous Mass Spectrometry (IMS) have been successfully applied for direct mass measurements of exotic nuclides at FRS-ESR facility at GSI. Both experimental methods are sensitive to single stored ions and can cover very efficiently a large number of nuclides in one run. Presently, more than 1100 masses of different nuclides have been covered by SMS and IMS in several FRS-ESR experiments whereby about 350 of them have been determined for the first time. In this paper, we present the status of our experimental program and use the experimental mass values to test the predictive power of modern mass models

Orbital electron capture and beta(+) decay of H-like Pr-141 ions

For the first time the electron capture and beta+ decay rates of H-like 140Pr ions have been measured at the FRS-ESR facility by using the Schottky noise technique. The H-like 140Pr58+ decay rate was found to be larger by a factor of 1.5 than in the case of neutral atom. This non-intuitive result can be explained by taking into account hyperfine splitting of nuclear levels in the decaying nuclei and the conservation law of the total angular momentum of the system