Information Theoretic Estimation of Clone Overlap Probabilities

This technical report describes preliminary research investigating the relationship between information theory and Bayes\u27 theory for estimation of the probability of clone overlap for the use in DNA restriction mapping. A number of languages (along with information theoretic metrics) capable of describing a hypothesized overlap are presented. For each language, the MML criterion is applied to the encoded overlaps of a pair of clones to search for that overlap which is most probable. The objective is to order the pair\u27s encoded overlaps, based on the MML criterion, from the most to the least probable. This ordering is compared to the ordering suggestion by the Bayesian probabilistic approach

Hydrogen sulfide: potent regulator of vascular tone and stimulator of angiogenesis

Hydrogen sulfide is the "third" gasotransmitter on the rise in cardiovascular research. Recent studies show that hydrogen sulfide has a great potential in the regulation of vascular tone of systemic arteries and many molecular targets are discussed. However, the complex mechanism of vascular tone regulation by hydrogen sulfide is only incompletely understood. It seems that a potent interaction of hydrogen sulfide with vascular endothelial growth factor (VEGF) becomes important in angiogenesis, in the process of wound healing, but also in tumor angiogenesis. Hydrogen sulfide exerts anti-inflammatory effects and it could be a pharmacological target in vascular dysfunction in association with obesity-related hypertension as well as in tumor development and progression. However, the underlying molecular pathways still need to be revealed. This review primarily focuses on the regulatory role of hydrogen sulfide in controlling vascular tone. We attempt to provide recent insights into mechanisms by which CSE-dependent hydrogen sulfide plays a role in the regulation of vascular tone by perivascular adipose tissue. The role of KCNQ channels and other ionic permeation pathways as key targets will be discussed. Recent findings which are summarized in this paper provide new insights into molecular mechanisms of hydrogen sulfide that are crucial for understanding vascular dysfunction in cardiovascular disease and possibly angiogenesis. Future research will be extended to investigate the therapeutic potential of hydrogen sulfide and their targets such as KCNQ channels in cardiovascular diseases, angiogenesis and tumor genesis

Supersymmetric quantum cosmological billiards

D=11 Supergravity near a space-like singularity admits a cosmological billiard description based on the hyperbolic Kac-Moody group E10. The quantization of this system via the supersymmetry constraint is shown to lead to wavefunctions involving automorphic (Maass wave) forms under the modular group W^+(E10)=PSL(2,O) with Dirichlet boundary conditions on the billiard domain. A general inequality for the Laplace eigenvalues of these automorphic forms implies that the wave function of the universe is generically complex and always tends to zero when approaching the initial singularity. We discuss possible implications of this result for the question of singularity resolution in quantum cosmology and comment on the differences with other approaches.Comment: 4 pages. v2: Added ref. Version to be published in PR

The Jabal Akhdar Dome in the Oman Mountains : evolution of a dynamic fracture system

Acknowledgments: This study was carried out within the framework of DGMK (German Society for Petroleum and Coal Science and Technology) research project 718 “Mineral Vein Dynamics Modelling,” which is funded by the companies ExxonMobil Production Deutschland GmbH, GDF SUEZ E&P Deutschland GmbH, RWE Dea AG and Wintershall Holding GmbH, within the basic research program of the WEG Wirtschaftsverband Erdo¨l- und Erdgasgewinnung e.V. We thank the companies for their financial support and their permission to publish these results. The German University of Technology in Oman (GU-Tech) is acknowledged for its logistic support. We gratefully acknowledge the reviewers Andrea Billi and Jean-Paul Breton, whose constructive reviews greatly improved the manuscriptPeer reviewedPreprin

A case study in decompounding for Bengali information retrieval

Decompounding has been found to improve information retrieval (IR) effectiveness for compounding languages such as Dutch, German, or Finnish. No previous studies, however, exist on the effect of decomposition of compounds in IR for Indian languages. In this case study, we investigate the effect of decompounding for Bengali, a highly agglutinative Indian language. Some unique characteristics of Bengali compounding are: i) only one constituent may be a valid word in contrast to the stricter requirement of both being so; and ii) the first character of the right constituent can be modified by the rules of sandhi in contrast to simple concatenation. While the standard approach of decompounding based on maximization of the total frequency of the constituents formed by candidate split positions has proven beneficial for European languages, our reported experiments in this paper show that such a standard approach does not work particularly well for Bengali IR. As a solution, we firstly propose a more relaxed decompounding where a compound word can be decomposed into only one constituent if the other constituent is not a valid word, and secondly we perform selective decompounding by employing a co-occurrence threshold to ensure that the constituent often co-occurs with the compound word, which in this case is representative of how related are the constituents with the compound. We perform experiments on Bengali ad-hoc IR collections from FIRE 2008 to 2012. Our experiments show that both the relaxed decomposition and the co-occurrence-based constituent selection proves more effective than the standard frequency-based decomposition. improving MAP up to 2:72% and recall up to 1:8%

Dynamics of Locomotor Fatigue during Supra-critical Power Exercise

Purpose; We aimed to measure 1) the dynamics of locomotor fatigue during constant supra-critical power cycling, and 2) the magnitude of any reserve in locomotor power at intolerance to constant and ramp-incremental cycling in recreationally-active volunteers. Methods; Fifteen participants (7 women and 8 men, 22±3 yr, 3.34±0.67 L.min-1 V[Combining Dot Above]O2peak) completed ramp-incremental and very-heavy constant power (205±46 W) exercise to the limit of tolerance. Immediately following intolerance, the ergometer was switched into the isokinetic mode and participants completed a short (~5 s) maximal isokinetic effort at 70 rpm. The time course of locomotor fatigue during constant supra-critical power exercise was characterized with these short maximal isokinetic sprints at 30, 60, 120, 180 s and at the limit of tolerance. Each bout was terminated following the isokinetic sprint. Results; Constant power exercise duration was 312±37 s. Isokinetic power production at 30, 60, 120, 180 s and the limit of tolerance (at 312±37 s) was 609±165, 503±195, 443±157, 449±133, and 337±94 W, respectively. Of the total decline in isokinetic power, ~36% occurred within the first minute of exercise and significant (p<0.05) reductions in isokinetic power occurred at all time-points vs the baseline maximal isokinetic power (666±158 W). Additionally, a significant power reserve of 132±74 W (64% of the task requirement) and 119±80 W (47%) was present at the limit of constant power and ramp-incremental exercise, respectively. Conclusions; Locomotor fatigue occurred rapidly during supra-critical power exercise with pseudo-exponential kinetics. Instantaneous isokinetic power production at the limit of tolerance exceeded that of the task requirement, regardless of the constant, or ramp work rate profile. Thus, the perceptual and physiologic limits were dissociated at the limit of tolerance in recreationally-active volunteers

Innovative interstellar explorer

An interstellar "precursor" mission has been under discussion in the scientific community for at least 30 years. Fundamental scientific questions about the interaction of the Sun with the interstellar medium can only be answered with in situ measurements that such a mission can provide. The Innovative Interstellar Explorer (IIE) and its use of Radioisotope Electric Propulsion (REP) is being studied under a NASA "Vision Mission" grant. Speed is provided by a combination of a high-energy launch, using current launch vehicle technology, a Jupiter gravity assist, and long-term, low-thrust, continuous acceleration provided by an ion thruster running off electricity provided by advanced radioisotope electric generators. A payload of ten instruments with an aggregate mass of ~35 kg and requiring ~30 W has been carefully chosen to address the compelling science questions. The nominal 20-day launch window opens on 22 October 2014 followed by a Jupiter gravity assist on 5 February 2016. The REP system accelerates the spacecraft to a "burnout" speed of 7.8 AU per year at 104 AU on 13 October 2032 (Voyager 1's current speed is ~3.6 AU/yr). The spacecraft will return at least 500 bits per second from at least 200 AU ~30 years after launch. Additional (backup) launch opportunities occur every 13 months to early 2018. In addition to addressing basic heliospheric science, the mission will ensure continued information on the far-heliospheric galactic cosmic ray population after the Voyagers have fallen silent and as the era of human Mars exploration begins

Relativistic Wavepackets in Classically Chaotic Quantum Cosmological Billiards

Close to a spacelike singularity, pure gravity and supergravity in four to eleven spacetime dimensions admit a cosmological billiard description based on hyperbolic Kac-Moody groups. We investigate the quantum cosmological billiards of relativistic wavepackets towards the singularity, employing flat and hyperbolic space descriptions for the quantum billiards. We find that the strongly chaotic classical billiard motion of four-dimensional pure gravity corresponds to a spreading wavepacket subject to successive redshifts and tending to zero as the singularity is approached. We discuss the possible implications of these results in the context of singularity resolution and compare them with those of known semiclassical approaches. As an aside, we obtain exact solutions for the one-dimensional relativistic quantum billiards with moving walls.Comment: 18 pages, 10 figure

Particle Acceleration in Relativistic Electron-positron Jets with Helical Magnetic Fields

The properties of relativistic jets, their interaction with the ambient environment and particle acceleration due to kinetic instabilities are studied self-consistently with Particle-in-Cell (PIC) simulations. In this work we study how a relativistic electron-positron jet containing a helical magnetic field evolves by focusing on its interaction with the external ambient plasma. Particularly, 3D PIC simulations are performed using a longer simulation system than previous studies with an embedded helical magnetic field. An important key issue in this work is how such a magnetic field affects an electron-positron jet and how this excites kinetic instabilities such as the Weibel instability (WI), the kinetic Kelvin-Helmholtz instability (kKHI) and others by further focusing on how particles accelerate. We do find that kinetic instabilities along with generated magnetic turbulence are present and consequently accelerate particles. At the linear stage we observe recollimation-like features at the center of the simulated jet and later-on as the electron-positron jet evolves, the magnetic fields generated by the instabilities become untangled and reorganized into a new topology near the non-linear phase. We additionally report indications of reconnection near the end of the non-linear stage, before the magnetic-field becomes untangled, as electrons get accelerated by multiple magnetic islands in the jet. In the present study the untangled magnetic field becomes turbulent without any reformation as it happened in our previous study of an electron-proton jet, which we will use to additionally compare the present results, obtaining important insights about the nature of these phenomena applicable to high-energy astrophysical environments such as Active Galactic Nuclei jets and Gamma-ray bursts.Comment: 12 pages, 24 figures, submitted to MNRAS Journa