Invariant Submanifolds of Generalized Sasakian-Space-Forms

The object of this paper is to study the invariant submanifolds of generalized Sasakian-space-forms. Here, we obtain some equivalent conditions for an invariant submanifold of a generalized Sasakian-space-forms to be totally geodesic.Comment: 11 page

Spectral formation in a radiative shock: application to anomalous X-ray pulsars and soft gamma-ray repeaters

In the fallback disk model for the persistent emission of Anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs), the hard X-ray emission arises from bulk- and thermal Comptonization of bremsstrahlung photons, which are generated in the accretion column. The relatively low X-ray luminosity of these sources implies a moderate transverse optical depth to electron scattering, with photons executing a small number of shock crossings before escaping sideways. We explore the range of spectral shapes that can be obtained with this model and characterize the most important parameter dependencies. We use a Monte Carlo code to study the crisscrossing of photons in a radiative shock in an accretion column and compute the resulting spectrum. As expected, high-energy power-law X-ray spectra are produced in radiative shocks with photon-number spectral index larger than or about 0.5. We find that the required transverse optical depth is between 1 and 7. Such spectra are observed in low-luminosity X-ray pulsars. We demonstrate here with a simple model that Compton upscattering in the radiative shock in the accretion column can produce hard X-ray spectra similar to those seen in the persistent and transient emission of AXPs and SGRs. In particular, one can obtain a high-energy power-law spectrum, with photon-number spectral index ~ 1 and a cutoff at 100 - 200 keV, with a transverse Thomson optical depth of ~ 5, which is shown to be typical in AXPs/SGRs.Comment: Accepted for publication in A&

Comparison of PI Controllers Designed for the Delay Model of TCP/AQM Networks

Cataloged from PDF version of article.One of the major problems of communication networks is congestion. In order to address this problem in TCP/IP networks, Active Queue Management (AQM) scheme is recommended. AQM aims to minimize the congestion by regulating the average queue size at the routers. To improve upon AQM, recently, several feedback control approaches were proposed. Among these approaches, PI controllers are gaining attention because of their simplicity and ease of implementation. In this paper, by utilizing the fluid-flow model of TCP networks, we study the PI controllers designed for TCP/AQM. We compare these controllers by first analyzing their robustness and fragility. Then, we implement these controllers in ns-2 platform and conduct simulation experiments to compare their performances in terms of queue length. Taken together, our results provide a guideline for choosing a PI controller for AQM given specific performance requirements. (C) 2013 Elsevier B.V. All rights reserved

Effect of Thidiazuron used as an Elicitor in the Production of Capsaicin on Total Protein and Phenolic Amounts, Antioxidant Enzyme Activities of Pepper Plants

The effect of thidiazuron (TDZ) used as an elicitor on the total phenolic, total protein, superoxide dismutase (SOD) and catalase (CAT) enzyme activities, and production of capsaicin in the cell suspension culture of Maraş-1 pepper seeds was determined. TDZ was applied in four levels (0, 0.1 mM, 0.2 mM, 0.4 mM) and at three times (days 8, 10, and 12) to the cell suspensions. The content of the capsaicin in suspended cells was identified by high-performance liquid chromatography after extraction with ethyl acetate. It was identified that TDZ had a variable effect on the capsaicin accumulation. The highest capsaicin content was determined by84.859 µg/g f.w. at 0.4 mM TDZ 10d. The highest increase by 181.48% at 0.2 mM TDZ 10d, the highestdecrease by 49.83% at 0.4 mM TDZ 10d was determined intotal phenolic amount. The total protein amount decreased at 0.4 mM TDZ 8dand 12d. The highest SOD (457.983 enzyme units/g f.w.) and CAT (0.143 enzyme units/g f.w.) activities at 0.4 mM TDZ 8d, the lowest SOD (73.526 enzyme units/g f.w.) and CAT (0.030 enzyme units/g f.w.) activities at 0.2 mM TDZ 12d were measured

Digitization of LAr calorimeter for CSC simulations

This note describes the digitization of the LAr signals, which is the step creating RDO from Geant4 Hits, as used during the production of the CSC simulated samples with athena release 12

The impact of temperature changes on summer time ozone and its precursors in the Eastern Mediterranean

Changes in temperature due to variability in meteorology and climate change are expected to significantly impact atmospheric composition. The Mediterranean is a climate sensitive region and includes megacities like Istanbul and large urban agglomerations such as Athens. The effect of temperature changes on gaseous air pollutant levels and the atmospheric processes that are controlling them in the Eastern Mediterranean are here investigated. The WRF/CMAQ mesoscale modeling system is used, coupled with the MEGAN model for the processing of biogenic volatile organic compound emissions. A set of temperature perturbations (spanning from 1 to 5 K) is applied on a base case simulation corresponding to July 2004. The results indicate that the Eastern Mediterranean basin acts as a reservoir of pollutants and their precursor emissions from large urban agglomerations. During summer, chemistry is a major sink at these urban areas near the surface, and a minor contributor at downwind areas. On average, the atmospheric processes are more effective within the first 1000 m above ground. Temperature increases lead to increases in biogenic emissions by 9±3% K<sup>−1</sup>. Ozone mixing ratios increase almost linearly with the increases in ambient temperatures by 1±0.1 ppb O<sub>3</sub> K<sup>−1</sup> for all studied urban and receptor stations except for Istanbul, where a 0.4±0.1 ppb O<sub>3</sub> K<sup>−1</sup> increase is calculated, which is about half of the domain-averaged increase of 0.9±0.1 ppb O<sub>3</sub> K<sup>−1</sup>. The computed changes in atmospheric processes are also linearly related with temperature changes

Smc5/6: a link between DNA repair and unidirectional replication?

Of the three structural maintenance of chromosome (SMC) complexes, two directly regulate chromosome dynamics. The third, Smc5/6, functions mainly in homologous recombination and in completing DNA replication. The literature suggests that Smc5/6 coordinates DNA repair, in part through post-translational modification of uncharacterized target proteins that can dictate their subcellular localization, and that Smc5/6 also functions to establish DNA-damage-dependent cohesion. A nucleolar-specific Smc5/6 function has been proposed because Smc5/6 yeast mutants display penetrant phenotypes of ribosomal DNA (rDNA) instability. rDNA repeats are replicated unidirectionally. Here, we propose that unidirectional replication, combined with global Smc5/6 functions, can explain the apparent rDNA specificity

Pearling: stroke segmentation with crusted pearl strings

We introduce a novel segmentation technique, called Pearling, for the semi-automatic extraction of idealized models of networks of strokes (variable width curves) in images. These networks may for example represent roads in an aerial photograph, vessels in a medical scan, or strokes in a drawing. The operator seeds the process by selecting representative areas of good (stroke interior) and bad colors. Then, the operator may either provide a rough trace through a particular path in the stroke graph or simply pick a starting point (seed) on a stroke and a direction of growth. Pearling computes in realtime the centerlines of the strokes, the bifurcations, and the thickness function along each stroke, hence producing a purified medial axis transform of a desired portion of the stroke graph. No prior segmentation or thresholding is required. Simple gestures may be used to trim or extend the selection or to add branches. The realtime performance and reliability of Pearling results from a novel disk-sampling approach, which traces the strokes by optimizing the positions and radii of a discrete series of disks (pearls) along the stroke. A continuous model is defined through subdivision. By design, the idealized pearl string model is slightly wider than necessary to ensure that it contains the stroke boundary. A narrower core model that fits inside the stroke is computed simultaneously. The difference between the pearl string and its core contains the boundary of the stroke and may be used to capture, compress, visualize, or analyze the raw image data along the stroke boundary

First Report of the Simulation Optimization Group

This is the first report of the ATLAS Simulation Optimization Group, established in June of 2007. This article justifies the selected Geant4 version, physics list, and range cuts to be used by the default ATLAS simulation for initial data taking and beyond. The current status of several projects, including detector description, simulation validation, studies of additional Geant4 parameters, and cavern background, are reported