Evaluation of control strategies for the spread of citrus greening

Huanglongbing, also known as citrus greening, is a vector-based disease in citrus (with no cure known to date) that has drastically affected the citrus production in Florida in less than a decade and has been recently detected in Texas and California. In this paper, an epidemic model of the spatial spread of the disease is implemented among commercial and residential groves by taking into consideration the diffusion patterns of the psyllid vectors. A system of differential equations resembling one for malaria infection in humans is derived to evaluate different control methods such as quarantine, treatment, removal, foliar treatment, and pest control, among others. Using numerical techniques to analyze location data we determine the optimal techniques for limiting the spread of the disease. Finally, we measure the effect non-commercial trees have in carrying the infection over longer distances even if control measures have been established in commercial groves

Predicting charged lepton flavor violation from 3-3-1 gauge symmetry

The simplest realization of the inverse seesaw mechanism in a $SU(3)_C \otimes SU(3)_L \otimes U(1)_X$ gauge theory offers striking flavor correlations between rare charged lepton flavor violating decays and the measured neutrino oscillations parameters. The predictions follow from the gauge structure itself without the need for any flavor symmetry. Such tight complementarity between charged lepton flavor violation and oscillations renders the scenario strictly testable.Comment: 7 pages, 2 figures; v2: discussion extended. Matches version published in PR

Notes on the proof of the van der Waerden permanent conjecture

The permanent of an $n\times n$ matrix $A=(a_{i j})$ with real entries is defined by the sum $$\sum_{\sigma \in S_n} \prod_{i=1}^{n} a_{i \sigma(i)}$$ where $S_n$ denotes the symmetric group on the $n$-element set $\{1,2,\dots,n\}$. In this creative component we survey some known properties of permanents, calculation of permanents for particular types of matrices and their applications in combinatorics and linear algebra. Then we follow the lines of van Lint\u27s exposition of Egorychev\u27s proof for the van der Waerden\u27s conjecture on the permanents of doubly stochastic matrices. The purpose of this component is to provide elementary proofs of several interesting known facts related to permanents of some special matrices. It is an expository survey paper in nature and reports no new findings

Consistency of WIMP Dark Matter as radiative neutrino mass messenger

The scotogenic scenario provides an attractive approach to both Dark Matter and neutrino mass generation, in which the same symmetry that stabilises Dark Matter also ensures the radiative seesaw origin of neutrino mass. However the simplest scenario may suffer from inconsistencies arising from the spontaneous breaking of the underlying $\mathbb{Z}_2$ symmetry. Here we show that the singlet-triplet extension of the simplest model naturally avoids this problem due to the presence of scalar triplets neutral under the $\mathbb{Z}_2$ which affect the evolution of the couplings in the scalar sector. The scenario offers good prospects for direct WIMP Dark Matter detection through the nuclear recoil method.Comment: 16 pages, 7 figure

Evaluación de la calidad en el servicio del restaurante Pizza Hut Villa Fontana de Diciembre 2014-Enero 2015

La calidad en el servicio del restaurante describe un papel importante para alcanzar en el desempeño de las operaciones. Esto consiste en si al grado de satisfacción que experimenta un cliente relacionado con la atención recibida, la eficiencia del servicio y la manera en que el servicio le fue entregado. Para que un restaurante alcance una buena calidad en el servicio este debe cumplir con las necesidades y expectativas de sus clientes ya que estos son lo más importante y quienes determinan que tan bueno es el servicio ofrecido por un establecimiento en particular. Para identificar cuáles son las necesidades y expectativas de los clientes y de esta manera brindar un servicio de alta calidad en un restaurante es necesario medir las percepciones de los clientes con respecto a las dimensiones y atributos que constituyen la calidad del servicio

Throttling positive semidefinite zero forcing propagation time on graphs

Zero forcing is a process on a graph that colors vertices blue by starting with some of the vertices blue and applying a color change rule. Throttling minimizes the sum of the size of the initial blue vertex set and the number of the time steps needed to color the graph. We study throttling for positive semidefinite zero forcing. We establish a tight lower bound on the positive semidefinite throttling number as a function of the order, maximum degree, and positive semidefinite zero forcing number of the graph, and determine the positive semidefinite throttling numbers of paths, cycles, and full binary trees. We characterize the graphs that have extreme positive semidefinite throttling numbers.Comment: 20 pages, 7 figures, in press, Discrete Appl. Mat

Revista de Comunicación en España. Una aproximación histórica

In Spain, scientific journals have become an important weight in the activity of dissemination of science. This text aims to present the current landscape of communication scientific journal in Spain and analyze its thematic, geographical distribution and temporal. Thus we will check how the scientific journal have increased communication and how have been inserting in the research activities of universities. Therefore we have analyzed the main Spanish journals in communication.En España, las revistas científicas han adquirido un peso importante en la actividad de difusión de la ciencia. Este texto persigue presentar el panorama actual de las revistas de comunicación en España y analizar su distribución geográfica, temática y temporal. Con ello vamos a comprobar cómo se han incrementado las revistas en comunicación y cómo se han ido insertando en la actividad investigadora de las universidades. Para ello, se han analizado las principales revistas españolas en comunicación

Sistema de verificación de certificados académicos basado en blockchain.

Trabajo de Fin de Grado. Grado en Ingeniería Informática. Curso académico 2021-2022.[ES]Desarrollo de una plataforma web para el almacenamiento de certificados académicos personales y conexión a plataformas educativas Moodle.[EN]Development of a web platform for the storage of personal academic certificates and connection to Moodle educational platforms

Analytical evaluation of two automatic methods to measure blood CK-MB mass and troponin I

The lack of standardization of methods to measure cardiac markers for coronaria ischaemia, particularly troponin, led us to perform an analytical evaluation of two new immunoassays to quantify CK-MB mass and troponin I using the Dimension R×L automatic analyser. The reliability and analytical intervals of the methods were studied as well as reference values (0.010— 0.228 μg l-1 for troponin I, 0.20—3.90 mg μg l-1 for CK-MB mass) and cuto¡ values (0.77 μg l-1 for troponin I, 5 μg l-1 for CK-MB mass) established. The cutoff values were established from 37 patients with acute myocardial infarction and from 20 with unstable angina. The absence of method cross-reactivity was corroborated using myocardial, brain and skeletal muscle tissue. Both methods were highly specific and showed good reliability and practicability in the diagnosis of coronaria ischaemia after 6 h of precordial pain

Relación música/texto en el canto gregoriano y en la polifonía y el concepto humanista de ritmo musical

Following the thread of the interrelation between music and text, this study is a reflection on the humanist concept of rhythm in Gregorian Chant. The consequences of the said concept succeeded in influencing vocal polyphony, as well, which was, however, all to its advantage.El presente trabajo ofrece una reflexión, siguiendo el hilo conductor de la "relación música/texto", sobre el concepto humanista del ritmo en el Canto Gregoriano. Las consecuencias de dicha concepción llegaron a afectar también a la polifonía vocal, en cuyo caso, diríamos que para su bien