70 research outputs found
Alliance free and alliance cover sets
A \emph{defensive} (\emph{offensive}) -\emph{alliance} in
is a set such that every in (in the boundary of ) has
at least more neighbors in than it has in . A set
is \emph{defensive} (\emph{offensive}) -\emph{alliance free,}
if for all defensive (offensive) -alliance , ,
i.e., does not contain any defensive (offensive) -alliance as a subset.
A set is a \emph{defensive} (\emph{offensive})
-\emph{alliance cover}, if for all defensive (offensive) -alliance ,
, i.e., contains at least one vertex from each
defensive (offensive) -alliance of . In this paper we show several
mathematical properties of defensive (offensive) -alliance free sets and
defensive (offensive) -alliance cover sets, including tight bounds on the
cardinality of defensive (offensive) -alliance free (cover) sets
Application of Business Intelligence in studies management of Hazard, Vulnerability and Risk in Cuba
In Cuba, the state invests considerable resources in the establishment of preparation plans to mitigate and to minimize the negative impacts of natural threats. As a sample of it, since the year 2010, the country carried out the studies of hazard, vulnerability, and risk (HVR), however, the form in that results of these studies are analyzed present serious limitations for the excessive quantity of data that are dispersed and not very understandable for users belonging to the Centers of Risks' Management make decisions in an agile way. The present work, exposes the management’s pattern of the studies of Hazard, Vulnerability and Risk in Cuba alongside the occurrence of hydrometeorological extreme events in vulnerable territories; and the structuring process of the computer proposal that modifies and computerizes the current analysis procedure of these studies in the country. As contributions of the research and by means of the use of techniques and tools of Business Intelligence, is designed and implemented, for the case of Santiago de Cuba province, the data warehouse that centralizes the results of the studies for hydrometeorological extreme events in 2011 and 2016. A decision support system (DSS-HVR) is built, and integrated at the developed data warehouse in this work, it allows the analysis of the studies in a holistic manner and from several perspectives, to obtain outstanding and better-represented information through interactive and dynamic reports, both tabulate and graph representation, all as a support for a fast and effective decision making
La enseñanza de la EstadÃstica utilizando herramientas dinámicas computacionales
Introducción: La formación estadÃstica de los futuros profesionales de la salud es muy importante para su posterior desarrollo profesional. Objetivo: Mostrar que la utilización de herramientas dinámicas computacionales para la simulación y demostración de conceptos en la enseñanza de la estadÃstica en actividades montadas y ejecutadas a través de la plataforma Moodle, contribuye a aumentar la comprensión de los conceptos estadÃsticos y mejorar la calidad de los trabajos cientÃficos realizados por estudiantes de medicina. Material y métodos: Durante el segundo semestre del curso 2013-2014, se realizó una experiencia pedagógica con dos grupos de segundo año; a un grupo se le impartió las clases utilizando las herramientas dinámicas y al otro, utilizando la forma tradicional. La variable independiente fue el uso de herramientas computacionales dinámicas montadas y ejecutadas a través de la plataforma Moodle, y las dependientes la comprensión de los conceptos estadÃsticos y la calidad de los trabajos cientÃficos. Resultados: En la prueba final no hubo diferencias estadÃsticamente significativas entre los resultados de ambos grupos (p=0,4>0,05), aunque la cantidad de aprobados en el grupo experimental (52,9%) fue superior a los del grupo de control (47,1%). En el grupo experimental la calidad de los trabajos cientÃficos superó al grupo de control (50% y 14,3% respectivamente). Conclusiones: El uso de las herramientas dinámicas en las clases de EstadÃstica, asà como la utilización de espacios virtuales para su aprendizaje puede contribuir a mejorar la calidad del aprendizaje de esta asignatura y una aplicación más adecuada de los conceptos estadÃsticos estudiados en la realización de trabajos investigativos.Palabras clave: Enseñanza semi-presencial de la EstadÃstica. EstadÃstica en un ambiente dinámico.Software dinámico. ABSTRACTThe teaching of Statistic utilizing dynamic computational toolsIntroduction: The training of undergraduate medical students in statistics is very important for their professional career. Objective: Showing the fact that using dynamically-computerized tools for simulating and demonstrating concepts underlying the teaching of statistics in Moodle-based activities, contributes to an increase in the comprehension of statistical concepts and improvement of scientific papers designed by these medical students. Material and methods: All across the second semester of the 2013-2014 Academic Year, some pedagogical experiment was conducted using a sample from two sophomore classes. The independent variable consisted in the use of dynamically-set computing tools, carried out using the Moodle platform, whereas the dependent (variables) was the students’ comprehension of statistical concepts and the quality of scientific papers. Results: The final test showed no significant statistic differences amongst both classes (p=0,4>0,05), even though the number of students who passed the test from the class undergoing the experiment (52,9 %) was higher than those in the control class (47,1%). The experiment-conducted class showed a better quality in scientific papers (50%) as compared to the other group (14,3%). Conclusions: The results of the final test and the students’ scientific work proved that the use of dynamic tools applied to the teaching of statistics and the use of virtual spaces can contribute to improve learning this subject and a better application of statistical concepts in research.Key words: Semi-frontal teaching of Statistics.DynamicStatistics. Dynamic Software. </p
When Color meets Gravity; Near-Threshold Exclusive Photoproduction on the Proton
The proton is one of the main building blocks of all visible matter in the
universe. Among its intrinsic properties are its electric charge, mass, and
spin. These emerge from the complex dynamics of its fundamental constituents,
quarks and gluons, described by the theory of quantum chromodynamics (QCD).
Using electron scattering its electric charge and spin, shared among the quark
constituents, have been the topic of active investigation until today. An
example is the novel precision measurement of the proton's electric charge
radius. In contrast, little is known about the proton's inner mass density,
dominated by the energy carried by the gluons, which are hard to access through
electron scattering since gluons carry no electromagnetic charge. In the
present work we chose to probe this gluonic gravitational density using a small
color dipole, the particle, through its threshold photoproduction.
From our data we determined, for the first time, the proton's gluonic
gravitational form factors, which encode its mass density. We used a variety of
methods and determined in all cases a mass radius that is notably smaller than
the electric charge radius. In some cases, the determined radius is in
excellent agreement with first-principle predictions from lattice QCD. This
work paves the way for a deeper understanding of the salient role of gluons in
providing gravitational mass to visible matter.Comment: Under peer revie
First Measurement of the EMC Effect in B and B
The nuclear dependence of the inclusive inelastic electron scattering cross
section (the EMC effect) has been measured for the first time in B and
B. Previous measurements of the EMC effect in nuclei showed
an unexpected nuclear dependence; B and B were measured to
explore the EMC effect in this region in more detail. Results are presented for
Be, B, B, and C at an incident beam energy of
10.6~GeV. The EMC effect in the boron isotopes was found to be similar to that
for Be and C, yielding almost no nuclear dependence in the EMC
effect in the range . This represents important, new data supporting
the hypothesis that the EMC effect depends primarily on the local nuclear
environment due to the cluster structure of these nuclei.Comment: Submitted to PR
Abundance of the Quorum-Sensing Factor Ax21 in Four Strains of Stenotrophomonas maltophilia Correlates with Mortality Rate in a New Zebrafish Model of Infection
Stenotrophomonas maltophilia is a Gram-negative pathogen with emerging nosocomial incidence. Little is known about its pathogenesis and the genomic diversity exhibited by clinical isolates complicates the study of pathogenicity and virulence factors. Here, we present a strategy to identify such factors in new clinical isolates of S. maltophilia, incorporating an adult-zebrafish model of S. maltophilia infection to evaluate relative virulence coupled to 2D difference gel electrophoresis to explore underlying differences in protein expression. In this study we report upon three recent clinical isolates and use the collection strain ATCC13637 as a reference. The adult-zebrafish model shows discrimination capacity, i.e. from very low to very high mortality rates, with clinical symptoms very similar to those observed in natural S. maltophilia infections in fish. Strain virulence correlates with resistance to human serum, in agreement with previous studies in mouse and rat and therefore supporting zebrafish as a replacement model. Despite its clinical origin, the collection strain ATCC13637 showed obvious signs of attenuation in zebrafish, with null mortality. Multilocus-sequence-typing analysis revealed that the most virulent strains, UV74 and M30, exhibit the strongest genetic similitude. Differential proteomic analysis led to the identification of 38 proteins with significantly different abundance in the three clinical strains relative to the reference strain. Orthologs of several of these proteins have been already reported to have a role in pathogenesis, virulence or resistance mechanisms thus supporting our strategy. Proof of concept is further provided by protein Ax21, whose abundance is shown here to be directly proportional to mortality in the zebrafish infection model. Indeed, recent studies have demonstrated that this protein is a quorum-sensing-related virulence factor
Strong Interaction Physics at the Luminosity Frontier with 22 GeV Electrons at Jefferson Lab
This document presents the initial scientific case for upgrading the
Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab)
to 22 GeV. It is the result of a community effort, incorporating insights from
a series of workshops conducted between March 2022 and April 2023. With a track
record of over 25 years in delivering the world's most intense and precise
multi-GeV electron beams, CEBAF's potential for a higher energy upgrade
presents a unique opportunity for an innovative nuclear physics program, which
seamlessly integrates a rich historical background with a promising future. The
proposed physics program encompass a diverse range of investigations centered
around the nonperturbative dynamics inherent in hadron structure and the
exploration of strongly interacting systems. It builds upon the exceptional
capabilities of CEBAF in high-luminosity operations, the availability of
existing or planned Hall equipment, and recent advancements in accelerator
technology. The proposed program cover various scientific topics, including
Hadron Spectroscopy, Partonic Structure and Spin, Hadronization and Transverse
Momentum, Spatial Structure, Mechanical Properties, Form Factors and Emergent
Hadron Mass, Hadron-Quark Transition, and Nuclear Dynamics at Extreme
Conditions, as well as QCD Confinement and Fundamental Symmetries. Each topic
highlights the key measurements achievable at a 22 GeV CEBAF accelerator.
Furthermore, this document outlines the significant physics outcomes and unique
aspects of these programs that distinguish them from other existing or planned
facilities. In summary, this document provides an exciting rationale for the
energy upgrade of CEBAF to 22 GeV, outlining the transformative scientific
potential that lies within reach, and the remarkable opportunities it offers
for advancing our understanding of hadron physics and related fundamental
phenomena.Comment: Updates to the list of authors; Preprint number changed from theory
to experiment; Updates to sections 4 and 6, including additional figure
Widespread distribution of Plasmodium vivax malaria in Mauritania on the interface of the Maghreb and West Africa
- …