Laplacian spread of graphs: lower bounds and relations with invariant parameters

The spread of an $n\times n$ complex matrix $B$ with eigenvalues $\beta _{1},\beta _{2},\ldots ,\beta _{n}$ is defined by \begin{equation*} s\left( B\right) =\max_{i,j}\left\vert \beta _{i}-\beta _{j}\right\vert , \end{equation*}% where the maximum is taken over all pairs of eigenvalues of $B$. Let $G$ be a graph on $n$ vertices. The concept of Laplacian spread of $G$ is defined by the difference between the largest and the second smallest Laplacian eigenvalue of $G$. In this work, by combining old techniques of interlacing eigenvalues and rank $1$ perturbation matrices new lower bounds on the Laplacian spread of graphs are deduced, some of them involving invariant parameters of graphs, as it is the case of the bandwidth, independence number and vertex connectivity

Expression of AdipoR1 and AdipoR2 Receptors as Leptin-Breast Cancer regulation mechanisms

: La obesidad es considerada como uno de los principales factores de riesgo implicados en el desarrollo del cáncer de mama y se ha documentado el papel que juega el tejido adiposo a través de Leptina y Adiponectina. El estudio de estas proteínas ha determinado su importancia en el desarrollo y progreso del cáncer de mama, pero muy pocos son los que han estudiado a AdipoR1 y AdipoR2 y la influencia de la Leptina sobre ellos. Se planteó el analizó la expresión de AdipoR1 y AdipoR2 modulada por concentraciones diferenciales de Leptina en un modelo de obesidad asociado a cáncer de mama en líneas celulares, utilizando sondas TaqMan®, mediado por concentraciones diferenciales de Leptina en líneas celulares. Seguido se llevó a cabo la extracción de RNA, obtención de cDNA (Retrotranscripción) y PCR en tiempo real. Se caracterizó cada línea celular por medio de Inmunohistoquímica. Concluyendo con base en los resultados que la concentración de normo-peso (10ng/mL) de leptina generó un incremento de la expresión de ambos receptores de adiponectina.The development of breast cancer is influenced by the adipose tissue through the proteins leptin and adiponectin. However, there is little research concerning AdipoR1 and AdipoR2 receptors and the influence of leptin over them. The objective of this work was to analyze the expression of AdipoR1 and AdipoR2, modulated by differential concentrations of leptin in an obesity model (10ng/mL, 100ng/mL, and 1000ng/mL) associated with breast cancer in MCF-7 and HCC1937 cell lines. Each cell was characterized through immunohistochemistry, and the expression of AdipoR1 and AdipoR2 was analyzed by PCR in real time using TaqMan® probes. Leptin induced an increase in cell population of MCF-7 (23.8%, 10ng/m, 48 h) and HCC1937 (17.24%, 1000ng/mL, 72 h). In MCF-7, the expression of AdipoR1 decreased (3.81%, 1000ng/Ml) and the expression of AdipoR2 increased by 13.74 times (10ng/mL) with regard to the control. In HCC1937, the expression of AdipoR1 decreases by 86.28% (10ng/mL), as well as the expression of AdipoR1 and AdipoR2 mRNA

Generación de procesos industriales virtuales orientados al aprendizaje de sistemas automáticos basados en PLCs

Esta tesis de ingeniería se ocupa de la utilización de herramientas de simulación en la automatización industrial. La tarea principal era crear modelos de simulación, incluidas sus aplicaciones de control, para ocho lugares de trabajo en la industria. Todos los modelos de simulación se realizaron utilizando la herramienta de simulación SIMIT 10.0.3. Las aplicaciones de control se crearon en el entorno de programación TIA Portal V15.This engineering thesis deals with the use of simulation tools in industrial automation. The main task was to create simulation models, including their control applications, for eight workplaces in the industry. All simulation models were performed using the SIMIT 10.0.3 simulation tool. The control applications were created in the TIA Portal V15 programming environment

Reemplazar el uso de diesel por cascarilla de arroz empleado para generación de vapor. aspectos técnicos y económicos

El fin de este informe es mostrar que la utilización cascarilla de arroz como combustible es viable y provechoso para el medio ambiente; la metodología usada consiste primeramente en tomar en cuenta la situación actual del arroz en el país con el objetivo de mostrar las zonas más productivas y tener una visión de cuanta cascarilla se dispone. Es evidente que la cascarilla de arroz siempre se ha considerado como un desecho por lo que en este informe se ponen de manifiesto algunas tecnologías de aprovechamiento de este recurso que bien pudieran dar réditos económicos si se los pone en práctica. Nuestro objetivo es la generación de vapor requerido en la industria para diferentes procesos; para ello se ha diagnosticado a la cascarilla de arroz en parámetros importantes como la humedad y le densidad que posee para poder hacerle frente a los combustibles tradicionales utilizados en nuestros días. Luego, se analizaran requerimientos tales como calderas y periféricos para la construcción de una planta de generación de vapor para finalmente por medio de datos proporcionados por una consultora, realizar un análisis financiero y determinar el grado de factibilidad económica que posee la utilización de este recurso para la producción de arroz parbolizad

Nonnegative Inverse Elementary Divisors Problem for Lists with Nonnegative Real Parts

In this paper, sufficient conditions for the existence and construction of nonnegative matrices with prescribed elementary divisors for a list of complex numbers with nonnegative real part are obtained, and the corresponding nonnegative matrices are constructed. In addition, results of how to perturb complex eigenvalues of a nonnegative matrix while keeping its elementary divisors and its nonnegativity are derived

Systemic risk and other interdependencies among banks in Bolivia

We performed a study of the Bolivian high-value payment system between 2015 and 2020 and of the network of interbank exposures between 2018 and 2020. We characterize the network structure of these systems and perform a systemic risk analysis. We find that the connectivity of the payment network has increased over time, and that it displays a core-periphery structure. Using the SinkRank algorithm, we identify two institutions as the most important throughout the period of study. However, by exploring daily, monthly and yearly networks, we find that, in general, the ranking depends on the level of temporal aggregation. Concerning interbank exposures, we carry out a systemic risk analysis using the DebtRank algorithm. In this analysis, we adjust the banks’ Tier 1 capital to account for credit risk from the commercial loans portfolios, based on the estimation of unexpected losses. We find that average DebtRank and vulnerability of banks tend to increase over time. We link this to a corresponding trend in the size of exposures. We observe spikes in DebtRank and vulnerability, which also occur in correspondence with spikes observed in the size of exposures

The Impact of Liquid Biopsies Positive for <em>EGFR</em> Mutations on Overall Survival in Non-Small Cell Lung Cancer Patients

In recent years, non-small cell lung cancer treatment has been revolutionized. EGFR tyrosine kinase inhibitors and our improved understanding of its alterations have driven new diagnostic strategies. Liquid biopsies have emerged as a useful tool in these contexts, showing potential utility in early diagnosis combined with low-dose CT scans, as well as potential in monitoring treatment response and predicting the development of patients. We studied the circulating tumor DNA (ctDNA) of 38 EGFR-mutated non-small cell lung cancer patients at diagnosis in different moments of their disease by liquid biopsy techniques. Our results show that mean overall survival was significantly lower when a liquid biopsy was positive for the detection of EGFR mutations compared with wild-type patients in their liquid biopsy in both univariate (29 ± 4 vs. 104 ± 19 months; p = 0.004) and multivariate analysis (p = 0.008). Taking this into consideration, liquid biopsies could be key to improving the control of this disease