The Holevo-Schumacher-Westmoreland Channel Capacity for a Class of Qudit Unital Channels

The Holevo-Schumacher-Westmoreland (HSW) classical (entanglement-unassisted) channel capacity for a class of qudit unital channels is shown to be C = log2(d) - Smin, where d is the dimension of the qudit, and Smin is the minimum possible von Neumann entropy at the channel output. The HSW channel capacity for tensor products of this class of unital qudit channels is shown to obey the same formula.Comment: 21 Pages. No Figure

Measurement of the Λ hyperon lifetime

A new, more precise measurement of the Lambda hyperon lifetime is performed using a large data sample of Pb-Pb collisions at root s(NN) = 5.02 TeV with ALICE. The Lambda and (Lambda)_bar hyperons are reconstructed at midrapidity using their two-body weak decay channel Lambda -> p + pi(-) and (Lambda)_bar -> (p )_bar + pi(+). The measured value of the Lambda lifetime is tau(Lambda) = [261.07 +/- 0.37(stat.) +/- 0.72o(syst)] ps. The relative difference between the lifetime of Lambda and (Lambda)_bar, which represents an important test of CPT invariance in the strangeness sector, is also measured. The obtained value (tau(Lambda) - tau((Lambda)_bar))/tau(Lambda) = (0.0013 +/- 0.0028(stat.) +/- 0.0021(syst.) is consistent with zero within the uncertainties. Both measurements of the. hyperon lifetime and of the relative difference between tau(Lambda) and tau((Lambda)_bar) are in agreement with the corresponding world averages of the Particle Data Group and about a factor of three more precise

Constraining the ages of the fireballs in the wake of the dIrr galaxy VCC1217 / IC3418

A complex of Halpha emitting blobs with strong FUV excess is associated to the dIrr galaxy VCC1217 / IC3418 (Hester et al. 2010), and extends up to 17 Kpc in the South-East direction. These outstanding features can be morphologically divided into diffuse filaments and compact knots, where most of the star formation activity traced by Halpha takes place. We investigate the properties of the galaxy and the blobs using a multiwavelength approach in order to constrain their origin. We collect publicly available data in UV and Halpha and observe the scene in the optical U,g,r,i bands with LBT. The photometric data allows to evaluate the star formation rate and to perform a SED fitting separately of the galaxy and the blobs in order to constrain their stellar population age. Moreover we analyze the color and luminosity profile of the galaxy and its spectrum to investigate its recent interaction with the Virgo cluster. Our analysis confirms that the most plausible mechanism for the formation of the blobs is ram pressure stripping by the Virgo cluster IGM. The galaxy colors, luminosity profile and SED are consistent with a sudden gas depletion in the last few hundred Myr. The SED fitting of the blobs constrains their ages in < 400 Myr.Comment: 10 pages, 11 figures, accepted for publication in Astronomy and Astrophysic

New technologies to improve root canal disinfection

Effective irrigant delivery and agitation are prerequisites to promote root canal disinfection and debris removal and improve successful endodontic treatment. This paper presents an overview of the currently available technologies to improve the cleaning of the endodontic space and their debridement efficacy. A PubMed electronic search was conducted with appropriate key words to identify the relevant literature on this topic. After retrieving the full-text articles, all the articles were reviewed and the most appropriate were included in this review. Several different systems of mechanical activation of irrigants to improve endodontic disinfection were analysed: manual agitation with gutta-percha cones, endodontic instruments or special brushes, vibrating systems activated by low-speed hand-pieces or by sonic or subsonic energy, use of ultrasonic or laser energy to mechanically activate the irrigants and apical negative pressure irrigation systems. Furthermore, this review aims to describe systems designed to improve the intracanal bacterial decontamination by a specific chemical action, such as ozone, direct laser action or light-activated disinfection. The ultrasonic activation of root canal irrigants and of sodium hypochlorite in particular still remains the gold standard to which all other systems of mechanical agitation analyzed in this article were compared. From this overview, it is evident that the use of different irrigation systems can provide several advantages in the clinical endodontic outcome and that integration of new technologies, coupled with enhanced techniques and materials, may help everyday clinical practice

The GALEX Ultraviolet Virgo Cluster Survey (GUViCS). II. Constraints on star formation in ram-pressure stripped gas

Context: Several galaxies in the Virgo cluster are known to have large HI gas tails related to a recent ram-pressure stripping event. The Virgo cluster has been extensively observed at 1539 A in the far-ultraviolet for the GALEX Ultraviolet Virgo Cluster Survey (GUViCS), and in the optical for the Next Generation Virgo Survey (NGVS), allowing a study of the stellar emission potentially associated with the gas tails of 8 cluster members. On the theoretical side, models of ram-pressure stripping events have started to include the physics of star formation. Aim: We aim to provide quantitative constraints on the amount of star formation taking place in the ram-pressure stripped gas, mainly on the basis of the far-UV emission found in the GUViCS images in relation with the gas content of the tails. Methods: We have performed three comparisons of the young stars emission with the gas column density: visual, pixel-by-pixel and global. We have compared our results to other observational and theoretical studies. Results: We find that the level of star formation taking place in the gas stripped from galaxies by ram-pressure is low with respect to the available amount of gas. Star formation is lower by at least a factor 10 compared to the predictions of the Schmidt Law as determined in regular spiral galaxy disks. It is also lower than measured in dwarfs galaxies and the outer regions of spirals, and than predicted by some numerical simulations. We provide constraints on the star formation efficiency in the ram-pressure stripped gas tails, and compare these with current models.Comment: Accepted in A&A, 17 pages (including the appendix and "on-line" figures of the paper

Advances on Testing C-Planarity of Embedded Flat Clustered Graphs

We show a polynomial-time algorithm for testing c-planarity of embedded flat clustered graphs with at most two vertices per cluster on each face.Comment: Accepted at GD '1

When a leader job resource can be ambivalent or even destructive: Independence at work as a double-edged sword

<div><p>Independence at work is commonly considered a job resource which fosters motivation and employee well-being. Somewhat paradoxically, it is embedded in a relationship, and employees’ independence also hinges on their leaders’ willingness to grant it. Analyzing this resource as part of the leader-follower relationship can be useful in exploring its beneficial, ambivalent, or detrimental reciprocal effects. We present two Actor-Partner Interdependence Models (APIM) which analyze leaders’ and followers’ independence as antecedents, and work engagement and emotional exhaustion as outcomes. We test our models on 112 pairs of UK workers, finding a significant partner effect between leaders’ independence and followers’ exhaustion. Our findings confirm the utility of a dyadic perspective for investigating leadership and well-being at work, and suggest improvements for leadership training and measures fostering job well-being.</p></div

Parkinson’s disease-linked Parkin mutations impair glutamatergic signaling in hippocampal neurons

Background Parkinson’s disease (PD)-associated E3 ubiquitin ligase Parkin is enriched at glutamatergic synapses, where it ubiquitinates multiple substrates, suggesting that its mutation/loss-of-function could contribute to the etiology of PD by disrupting excitatory neurotransmission. Here, we evaluate the impact of four common PD-associated Parkin point mutations (T240M, R275W, R334C, G430D) on glutamatergic synaptic function in hippocampal neurons. Results We find that expression of these point mutants in cultured hippocampal neurons from Parkin-deficient and Parkin-null backgrounds alters NMDA and AMPA receptor-mediated currents and cell-surface levels and prevents the induction of long-term depression. Mechanistically, we demonstrate that Parkin regulates NMDA receptor trafficking through its ubiquitination of GluN1, and that all four mutants are impaired in this ubiquitinating activity. Furthermore, Parkin regulates synaptic AMPA receptor trafficking via its binding and retention of the postsynaptic scaffold Homer1, and all mutants are similarly impaired in this capacity. Conclusion Our findings demonstrate that pathogenic Parkin mutations disrupt glutamatergic synaptic transmission in hippocampal neurons by impeding NMDA and AMPA receptor trafficking. Such effects may contribute to the pathophysiology of PD in PARK2 patients

Computing NodeTrix Representations of Clustered Graphs

NodeTrix representations are a popular way to visualize clustered graphs; they represent clusters as adjacency matrices and inter-cluster edges as curves connecting the matrix boundaries. We study the complexity of constructing NodeTrix representations focusing on planarity testing problems, and we show several NP-completeness results and some polynomial-time algorithms. Building on such algorithms we develop a JavaScript library for NodeTrix representations aimed at reducing the crossings between edges incident to the same matrix.Comment: Appears in the Proceedings of the 24th International Symposium on Graph Drawing and Network Visualization (GD 2016