On the geometry of normal horospherical G-varieties of complexity one

Let G be a connected simply-connected reductive algebraic group. In this article, we consider the normal algebraic varieties equipped with a horospherical G-action such that the quotient of a G-stable open subset is a curve. Let X be such a G-variety. Using the combinatorial description of Timashev, we describe the class group of X by generators and relations and we give a representative of the canonical class. Moreover, we obtain a smoothness criterion for X and a criterion to determine whether the singularities of X are rational or log-terminal respectively.Comment: 29 pages, final version, to appear in J. Lie Theor

The Cox ring of a complexity-one horospherical variety

Cox rings are intrinsic objects naturally generalizing homogeneous coordinate rings of projective spaces. A complexity-one horospherical variety is a normal variety equipped with a reductive group action whose general orbit is horospherical and of codimension one. In this note, we provide a presentation by generators and relations for the Cox rings of complete rational complexity-one horospherical varieties.Comment: 9 pages, to appear in Arch. Mat

Eye Movement Control During Reading: A Simulation of Some Word-Targeting Strategies

McConkie, Kerr, Reddix, & Zola [(1988). Vision Research, 28, 1107–1118] demonstrated that the distributions of landing sites on a word tended to be gaussian in shape. They provided a detailed account of the behaviour of the eye once a target had been selected and a saccade initiated, but said little about the process of target selection itself. The purpose of this study was to take as a starting point the landing site distributions of McConkie et al., in particular the residuals derived from fitting the gaussians to the empirical data, and to explore by computer simulation a number of saccade targeting strategies in order to discover candidates that best accounted for the residual data. Our results indicate that the strategy that gives the best fit involves targeting the longest word in a right parafoveal window extending 20 characters to the right of the currently fixated word. The implications of this finding for models of reading are discussed

The Contribution and Prospects of the Technical Development on Implementation of Electric and Hybrid Vehicles

Zoran Nikolić and Zlatomir Živanovic (2012). The Contribution and Prospects of the Technical Development on Implementation of Electric and Hybrid Vehicles, New Generation of Electric Vehicles, Prof. Zoran Stevic (Ed.), ISBN: 978-953-51-0893-1, InTech, DOI: 10.5772/51771. Available from: http://www.intechopen.com/books/new-generation-of-electric-vehicles/the-contribution-and-prospects-of-the-technical-development-on-implementation-of-electric-and-hybri

An overview of the planned CCAT software system

CCAT will be a 25m diameter sub-millimeter telescope capable of operating in the 0.2 to 2.1mm wavelength range. It will be located at an altitude of 5600m on Cerro Chajnantor in northern Chile near the ALMA site. The anticipated first generation instruments include large format (60,000 pixel) kinetic inductance detector (KID) cameras, a large format heterodyne array and a direct detection multi-object spectrometer. The paper describes the architecture of the CCAT software and the development strategy.Comment: 17 pages, 6 figures, to appear in Software and Cyberinfrastructure for Astronomy III, Chiozzi & Radziwill (eds), Proc. SPIE 9152, paper ID 9152-10

The relationships between distances covered above generic andrelative speed thresholds by male soccer players in EnglishPremier League matches across two competitive seasons.The effects of positional demands and possession

The aims of this study were to: a) examine the relationships between high-intensity distances covered above generic and relative speed thresholds in English Premier League (EPL) matches across two consecutive seasons and b) analyze the effects of playing position and team possession. Sixteen elite male soccer players (seven defenders, six midfielders and three forwards) participated in this study (age 27.8 ± 3.5 years, height 183.7 ± 5.4 cm, body mass 83.9 ± 7.1 kg). An Optical Tracking System was used to collect the following variables: total distance covered; high-speed running distance (HSRD) (> 5.5 m/s); high-intensity running distance (HIRD) (5.5–7 m/s); sprint distance (> 7 m/s); total distance covered above Maximal Aerobic Speed (MAS); distance covered > 85% peak speed (PS); and distance > 30% Anaerobic Speed Reserve (ASR). All measures were analyzed as whole match totals and as distances covered in the periods of the team in possession (TIP), opponent team in possession (OTIP), and ball out of play (BOP). Analysis by position based on defenders, midfielders and forwards was also performed. Distance > 30% ASR was almost perfectly correlated with HSRD (r = 0.98), while distances > MAS were highly correlated with both HIRD (r = 0.91) and HSRD (r = 0.91), and distance > 85% PS were highly correlated with SD (r = 0.70). Although the generic and relative speed thresholds show almost perfect correlation, the differences between HSRD, HIRD and distance > MAS indicate that players may be exposed to more HIRD when using relative thresholds.info:eu-repo/semantics/publishedVersio

The relationship between VO2 max and 1200m shuttle run performance in elite academy football players

Purpose: To investigate the relationship between VO2 max and performance in the 1200m shuttle run test in elite Premier League academy football players. Methods: Seventeen male professional outfield football players completed a laboratory based incremental treadmill test to establish vVO2 max and a field based 1200m shuttle test to estimate velocity at MAS. During the pre-season period a linear speed phase consisting of twice weekly PS exposures were conducted and each player’s PS reached during this period was established. Body composition was measured using DEXA. Results: Examining the standardized (scaled) coefficients, ASR (7.373) had the largest effect on VO2 max followed by PS (-5.568), MAS (3.604), Body Fat (-0.285) and Lean Mass (-0.185).The results suggest that the model is a significantly better predictor than a model that constantly predicts the mean VO2max value (F = 3.422, p = 0.041). Conclusions: The MAS values obtained from the 1200m shuttle test may be an appropriate assessment to consider when monitoring and individualizing high-intensity performance rather than the generic threshold of 5.5 m/s.info:eu-repo/semantics/publishedVersio

On Lagrangian Coherent Structures in Laparoscopy

Laparoscopy is an electrosurgical medical operation often involving an application of high-frequency alternating current to remove undesired biological tissue from the insufflated abdomen accessible through inlet and outlets trocars. One of the main byproducts in this process are the gaseous particles, called surgical smoke, which is found hazardous for both the patient and the operating room staff. The elimination of this hazardous material is an area of active research in the medical community. Thus, understanding dynamics influenced by the underlying flow inside the abdomen is crucial. In this article, we propose a computational fluid dynamics model and analyse the velocity field in an insufflated abdomen shaped domain by identifying the Lagrangian Coherent Structures (LCS) that are responsible for the transportation, mixing and accumulation of the material particles in the flow. By calculating the mixing strength we show that the regions revealed by these material curves are dependent on the angle, positions and number of the outlets and inlets. Hence, a novel utility of LCS in medical surgery is presented that can detail the dynamics of surgical smoke informing better design of effective smoke removal technologies