Update of MRST parton distributions.

We discuss the latest update of the MRST parton distributions in response to the most recent data. We discuss the areas where there are hints of difficulties in the global fit, and compare to some other updated sets of parton distributions, particularly CTEQ6. We briefly discuss the issue of uncertainties associated with partons

MRST global fit update.

We discuss the impact of the most recent data on the MRST global analysis - in particular the new high-ET jet data and their implications for the gluon and the new small x structure function data. In the light of these new data we also consider the uncertainty in predictions for physical quantities depending on parton distributions, concentrating on the W cross-section at hadron colliders

Recent progress in parton distributions and implications for LHC physics

I outline some of the most recent developments in the global fit to parton distributions performed by the MRST collaboration

MRST partons and uncertainties.

We discuss uncertainties in the extraction of parton distributions from global analyses of DIS and related data. We present conservative sets of partons, at both NLO and NNLO, which are stable to x,Q2,W2 cuts on the data. We give the corresponding values of S(M2 Z) and the cross sections for W production at the Tevatron

Structural parameterizations for boxicity

The boxicity of a graph $G$ is the least integer $d$ such that $G$ has an intersection model of axis-aligned $d$-dimensional boxes. Boxicity, the problem of deciding whether a given graph $G$ has boxicity at most $d$, is NP-complete for every fixed $d \ge 2$. We show that boxicity is fixed-parameter tractable when parameterized by the cluster vertex deletion number of the input graph. This generalizes the result of Adiga et al., that boxicity is fixed-parameter tractable in the vertex cover number. Moreover, we show that boxicity admits an additive $1$-approximation when parameterized by the pathwidth of the input graph. Finally, we provide evidence in favor of a conjecture of Adiga et al. that boxicity remains NP-complete when parameterized by the treewidth.Comment: 19 page

Senior management model applied to micro, small and medium business

Siendo Colombia un país cuya economía se soporta en empresas de pequeña escala, donde las MIPYMES en conjunto representando el 90%, sector que genera el 73% de empleos y el 53% de la producción bruta en los diferentes sectores industriales, comerciales y de los servicios. No obstante de la importancia de este sector en la economía, muchas de ellas enfrentan una problemática que interrumpen su crecimiento y desarrollo. Este trabajo de investigación tiene como finalidad estructurar un modelo gerencial, el cual recoge aspectos importantes y valiosos a tener en cuenta por los dueños, gerentes y administradores; producto de identificar las debilidades que han impedido su crecimiento y desarrollo de manera efectiva en el campo empresarial moderno. Por lo anterior se analizó como debilidades más sentidas el desconocimiento y aplicación de teorías actuales en materia gerencial, que pueden actuar en miras de un mayor crecimiento y diversificación de sus ofertas de bienes y servicios, en este caso en el campo de los cosméticos; Soportado en los conocimientos adquiridos durante la Especialización en Alta Gerencia, se define desde un punto de vista particular pero responsable, los temas que deberían ser revisados por este tipo de empresas, para lograr la mejor comprensión y aplicación de temas tan importantes como Pensamiento Complejo, Análisis y Estudios de Competencias, Planeamiento Estratégico y Financiero, Gerencia de Mercado y Talento Humano.Colombia is a country whose economy is supported in small scale enterprises, where MIPYMES altogether representing 90%, sector that generates 73% of jobs and 53% of gross in the various sectors of industrial, commercial production and services. But the importance of this sector in the economy, many of them face problems that disrupt their growth and development. This research paper aims to structure a management model, which collects valuable and important aspects to be considered by owners and managers; product identify the weaknesses that have prevented its growth and development effectively in the modern business field. Therefore analyzed as most pressing weaknesses lack of knowledge and application of current theories in the management field, which may act in view of further growth and diversification of its offers of goods and services, in this case in the field of cosmetics; Supported the knowledge gained during the specialization in senior management, defined from a point of view responsible, but particular issues that should be reviewed by this kind of companies, to achieve better understanding and application of such important topics as complex thought, analysis and studies of competencies, strategic planning and financial, market and human resource managemen

Challenges of Profile Likelihood Evaluation in Multi-Dimensional SUSY Scans

Statistical inference of the fundamental parameters of supersymmetric theories is a challenging and active endeavor. Several sophisticated algorithms have been employed to this end. While Markov-Chain Monte Carlo (MCMC) and nested sampling techniques are geared towards Bayesian inference, they have also been used to estimate frequentist confidence intervals based on the profile likelihood ratio. We investigate the performance and appropriate configuration of MultiNest, a nested sampling based algorithm, when used for profile likelihood-based analyses both on toy models and on the parameter space of the Constrained MSSM. We find that while the standard configuration is appropriate for an accurate reconstruction of the Bayesian posterior, the profile likelihood is poorly approximated. We identify a more appropriate MultiNest configuration for profile likelihood analyses, which gives an excellent exploration of the profile likelihood (albeit at a larger computational cost), including the identification of the global maximum likelihood value. We conclude that with the appropriate configuration MultiNest is a suitable tool for profile likelihood studies, indicating previous claims to the contrary are not well founded.Comment: 21 pages, 9 figures, 1 table; minor changes following referee report. Matches version accepted by JHE

Bridging flavour violation and leptogenesis in SU(3) family models

We reconsider basic, in the sense of minimal field content, Pati-Salam x SU(3) family models which make use of the Type I see-saw mechanism to reproduce the observed mixing and mass spectrum in the neutrino sector. The goal of this is to achieve the observed baryon asymmetry through the thermal decay of the lightest right-handed neutrino and at the same time to be consistent with the expected experimental lepton flavour violation sensitivity. This kind of models have been previously considered but it was not possible to achieve a compatibility among all of the ingredients mentioned above. We describe then how different SU(3) messengers, the heavy fields that decouple and produce the right form of the Yukawa couplings together with the scalars breaking the SU(3) symmetry, can lead to different Yukawa couplings. This in turn implies different consequences for flavour violation couplings and conditions for realizing the right amount of baryon asymmetry through the decay of the lightest right-handed neutrino. Also a highlight of the present work is a new fit of the Yukawa textures traditionally embedded in SU(3) family models.Comment: 26 pages, 5 figures, Some typos correcte

Quantifying Morphological Evolution from Low to High Redshifts

Establishing the morphological history of ordinary galaxies was one of the original goals for the Hubble Space Telescope, and remarkable progress toward achieving this this goal has been made. How much of this progress has been at the expense of the Hubble sequence? As we probe further out in redshift space, it seems time to re-examine the underlying significance of Hubble's tuning fork in light of the the spectacular and often bizarre morphological characteristics of high redshift galaxies. The aim of this review is to build a morphological bridge between high-redshift and low-redshift galaxy populations, by using quantitative morphological measures to determine the maximum redshift for which the Hubble sequence provides a meaningful description of the galaxy population. I will outline the various techniques used to quantify high-redshift galaxy morphology, highlight the aspects of the Hubble sequence being probed by these techniques, and indicate what is getting left behind. I will argue that at higher redshifts new techniques (and new ideas) that place less emphasis on classical morphology and more emphasis on the link between morphology and resolved stellar populations are needed in order to probe the evolutionary history of high-redshift galaxies