Approximation for single-channel multi-server queues and queuing networks with generally distributed inter-arrival and service times

This dissertation is divided into two papers. The first paper is related to developing a closed-form approximation for single-channel multiple-server queues with generally distributed inter-arrival and service times, which are often found in numerous settings, e.g., airports and manufacturing systems. Unfortunately, exact models for such systems require distributions for the underlying random variables. Further, data for fitting distributions is sometimes not available, and one only has access to means and variances of the underlying input random variables. Under heavy traffic, excellent approximations already exist for this purpose. In the first paper, a new approximation method for medium traffic is presented. Encouraging numerical evidence for gamma distributed inter-arrival times, often found in many settings, and double-tapering distributions, such as normal, triangular, and gamma, for the service time, is found with the new approximation. In the second paper, a new approximation technique is studied for modeling a two-stage queueing network (QN) in which the first stage contains a multiple-server (G/G/k) queue and the second is composed of multiple single-server queues (G/G/1) in parallel. Airport terminals and other service areas, such as sports stadiums and manufacturing systems, are examples of systems where such two-stage QNs are encountered. The new approximation is rooted in approximating the variance of the service time in a G/G/k queue and leads to encouraging numerical behavior --Abstract, page iv

Characterizing filaments harboring high-mass star formation

Màster Oficial d'Astrofísica, Física de Partícules i Cosmologia, Facultat de Física, Universitat de Barcelona, Curs: 2016-2017, Tutors: Gemma Busquet, Robert EstalellaA distinguished kind of molecular clouds, the infrared dark clouds (hereafter IRDCs), are believed to be relevant for describing the initial conditions for high-mass star formation. They are characterized by their lack of detectable emission in the mid-infrared: they appear as a dark silhouette against the corresponding mid-infrared background. IRDCs were first recognized in images from the Infrared Space Observatory (ISO, Egan et al. 1998) and the Midcourse Space Experiment (MSX, Perault et al. 1996

Estudio comparativo entre pacientes sanos y con disfunción temporomandibular mediante análisis cefalométricos

Los trastornos funcionales del sistema masticatorio son una patología muy frecuente, compleja y de muy difícil diagnóstico, especialmente cuando uno o más signos de la enfermedad no están presentes. El propósito del presente trabajo es determinar si por medio del análisis de la topografía ósea craneal con datos obtenidos en estudios cefalométricos, es posible encontrar un signo patognomónico que ayude el diagnóstico de la disfunción temporomandibular. En 189 pacientes de los cuales 150 fueron mujeres y 39 hombres, se analizó si la relación en altura entre la proyección posterior del plano oclusal y el centro geométrico de la rama ascendente o punto Xi, presenta diferencias significativas, cuando la medición se realiza en pacientes sanos o con Disfunción Temporomandibular. Los resultados encontrados se distribuyen homogéneamente entre 0 mm y 5,5 mm en los grupos “Control Femenino” y “Caso control” mientras que en el grupo “Control masculino” aproximadamente el 60% de las determinaciones se encuentran en el rango 2 mm a 3,5 mm. Los resultados de las mediciones obtenidas, nos permiten concluir que no hay diferencias estadísticamente significativas entre los resultados registrados en los cuatro grupos experimentales donde P= 0,7.The functional disorders of the masticatory system are a very frequent, complex pathology and of very difficult diagnosis, specially when one or more signs of the disease are not present. The intention of the present work is to determine if by means of the analysis of the osseous cranial topography with information obtained in cefalometrics studies, it is possible to find a patognomonic sign that helps the diagnosis of the Temporomandibular Dysfunction. They were analyzed in 189 patients of which 150 were women and 39 were men, if the relation in height among the posterior projection of the oclusal plane and the geometric center of the rising branch or Xi point, presents significant differences, when the measurement is realized in healthy patients or with temporomandibular dysfunction. The results are distributed homogeneously among 0 mm and 5,5 mm in the groups “ Female Control “ and “ Control case”, whereas in the group “ Male control “ approximately 60 % of the determinations is in the range 2 mm to 3,5 mm. The results of the measurements, allow us to conclude that there are no statistically significant differences between the results registered in four experimental groups where P = 0,7.Facultad de Odontologí

Expression of oxidative stress and antioxidant defense genes in the kidney of inbred mice after intestinal ischemia and reperfusion

PURPOSE: To determine the gene expressions profile related to the oxidative stress and the antioxidant response in the kidneys of mice subjected to intestinal ischemia and reperfusion. METHODS: Twelve inbred mice (C57BL/6) were randomly assigned to one of two groups: the control group (CG) underwent anesthesia and was observed for 120 min and the ischemia/reperfusion group (IRG), animals were anesthetized and subjected to laparotomy and ischemia for 60 minutes followed by 60 minutes of reperfusion. The expressions of 84 genes from the kidney were determined by the Reverse Transcription qualitative Polymerase Chain Reaction (RT-qPCR). All genes that were up regulated by more than threefold using the algorithm [2(ΔΔCt)] were considered statically significant (p<0.05). RESULTS: In the IRG group 29 (34.52%) of 84 genes, were up regulated by more than threefold. The genes that were differentially up regulated in the glutathione peroxidase cluster (10 genes): were Gpx2 and Gpx7. The genes that were up regulated in the peroxidase cluster (16 genes) were following: Duox1, Epx, Lpo, Mpo, Ptgs2, Rag2, Serpinb1b, Tmod1 and Tpo. The genes that up regulated in the reactive oxygen species cluster (16 genes): Il19, Il22, Nos2, Nox1, Noxa1, Noxo1, Recql4 and Sod2. The genes that were up regulated in the oxidative stress cluster (22 genes) were: Mpp4, Nudt15, Upc3 and Xpa. The genes that were up regulated in the oxygen carriers cluster (12 genes) were: Hbq1, Mb, Ngb, Slc38a1 and Xirp1. The peroxiredoxins genes (10) showed no consistent differential regulation. CONCLUSION: The genes related to oxidative stress and antioxidant defense showed increased expression in renal tissue trigged intestinal ischemia and reperfusion.São Paulo Federal University Postgraduate Program in Interdisciplinary Surgical SciencesMato Grosso do Sul Federal University Surgery DepartmentGrande Dourados Federal University Medical SchoolUFGD Medical SchoolUNIFESP Surgery Department Surgical Techniques and Experimental Surgery DivisionSão Paulo Federal University Postgraduate Program in Interdisciplinary Surgical SciencesUNIFESP, Surgery Department Surgical Techniques and Experimental Surgery DivisionSciEL

Gene expression profile of oxidative stress in the lung of inbred mice after intestinal ischemia/reperfusion injury

PURPOSE:To determine the gene expression profile associated with oxidative stress and antioxidant defense in the lung tissue of mice subjected to intestinal ischemia and reperfusion.METHODS:Twelve male, inbred mice (C57BL/6) were randomly assigned to one of two groups. The control group (CG) underwent anesthesia and laparotomy and was observed for 120 minutes; the ischemia/reperfusion group (IRG) was subjected to anesthesia, laparotomy, and ischemia of the small intestine for 60 minutes and to 60 minutes of reperfusion. A pool of six mice from each group was subjected to a reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to analyze the oxidative stress and antioxidant defense genes. All genes that were up-regulated or down-regulated greater than three-fold, based on the algorithm [2Federal University of Grande Dourados Medical SchoolUFGD Medical SchoolFederal University of Mato Grosso do Sul Surgery DepartmentUniversitary Center Sao CamiloUNIFESP Surgery DepartmentUNIFESP, Surgery DepartmentSciEL

Mechanisms of brain aging regulation by insulin : implications for neurodegeneration in late-onset Alzheimer’s disease

Insulin and IGF seem to be important players in modulating brain aging. Neurons share more similarities with islet cells than any other human cell type. Insulin and insulin receptors are diffusely found in the brain, especially so in the hippocampus. Caloric restriction decreases insulin resistance, and it is the only proven mechanism to expand lifespan. Conversely, insulin resistance increases with age, obesity, and sedentarism, all of which have been shown to be risk factors for late-onset Alzheimer’s disease (AD). Hyperphagia and obesity potentiate the production of oxidative reactive species (ROS), and chronic hyperglycemia accelerates the formation of advanced glucose end products (AGEs) in (pre)diabetes—both mechanisms favoring a neurodegenerative milieu. Prolonged high cerebral insulin concentrations cause microvascular endothelium proliferation, chronic hypoperfusion, and energy deficit, triggering β-amyloid oligomerization and tau hyperphosphorylation. Insulin-degrading enzyme (IDE) seems to be the main mechanism in clearing β-amyloid from the brain. Hyperinsulinemic states may deviate IDE utilization towards insulin processing, decreasing β-amyloid degradation

TRIDIMENSIONAL (3D) MODELING OF TRUNKS AND COMMERCIAL LOGS OF Tectona grandis L.f.

The development and application of technological innovations have been some of the main focuses of the productive sectors. One technological innovation that has been gaining prominence is the three-dimensional modeling (3D) of inventory and forest planning activities. In this study, it was possible to assess the accuracy of three-dimensional scanning of trunks of Tectona grandis L.f. by digital photogrammetry by using photos taken with a smartphone. The study was carried out in a Teak plantation of 46.54 ha. Systematic sampling by plots was used. Based on the diametric distribution of the stand, thirty trees were selected for the three-dimensional scanning procedure by the Close to Range technique. After three-dimensional scanning, each tree was scaled by the Smalian method and sectioned into 2.35 meters long logs for assessment using the xylometer method. The thirty trees resulted in 121 logs that had their volumes measured using the xylometer. Using three-dimensional modeling, it was possible to model and measure the volume of 71 logs in classes A (0.10 to 2.45), B (2.45 to 4.80), and C (4.80 to 7.15). The trunk of the trees could not be modeled for all trees at the highest heights because of the quality of the cloud of data points. Records that could not be entirely modeled (2.35 meters) were ignored. The cubing methods were compared by the paired t-test. Therefore, it was possible to model lower logs (0.10 m to 2.45 m) more accurately than by using the traditional Smalian method, with a one-meter interval between sections

Early growth of camu-camu plants with nitrogen fertilization through fertirrigation

The objective of this study was to evaluate the effect of different doses of nitrogen (N), applied via fertirrigation, on the initial growth components of the camu-camu plants. It was conducted with the use of a randomized block experimental design with 5 treatments: 0; 40; 80; 120 and 160 kg ha-1 of N, eight replicates and seven plants per experimental parcel. The experiment lasted for a period of 270 days. The diameter of stem (mm) and the height of the plant (cm) were evaluated every 30 days and the number of branches and total length of branches (cm) were evaluated every 90 days. At the end of the experiment, chlorophyll a index, dry mass of the leaves (g), dry mass of the branches (g), dry mass of the roots (g), total dry mass (g), and the Dickson Quality Index (DQI) were evaluated. According to the results, camu-camu plants that did not receive nitrogen fertilization had a lower initial growth and the doses of N significantly influenced all parameters evaluated in the camu-camu plants, including parameters from a linear and a quadratic model. The dose of 123 kg ha-1 of N, applied via fertirrigation, produced better quality camu-camu plants. Furthermore, greater doses caused depressive effects on growth of camu-camu plants in the first year of cultivation in firm ground conditions and the indirect measurement of chlorophyll a index in camu-camu plants was suitable for the assessment of nutritional status in relation to N.The objective of this study was to evaluate the effect of different doses of nitrogen (N), applied via fertirrigation, on the initial growth components of the camu-camu plants. It was conducted with the use of a randomized block experimental design with 5 treatments: 0; 40; 80; 120 and 160 kg ha-1 of N, eight replicates and seven plants per experimental parcel. The experiment lasted for a period of 270 days. The diameter of stem (mm) and the height of the plant (cm) were evaluated every 30 days and the number of branches and total length of branches (cm) were evaluated every 90 days. At the end of the experiment, chlorophyll a index, dry mass of the leaves (g), dry mass of the branches (g), dry mass of the roots (g), total dry mass (g), and the Dickson Quality Index (DQI) were evaluated. According to the results, camu-camu plants that did not receive nitrogen fertilization had a lower initial growth and the doses of N significantly influenced all parameters evaluated in the camu-camu plants, including parameters from a linear and a quadratic model. The dose of 123 kg ha-1 of N, applied via fertirrigation, produced better quality camu-camu plants. Furthermore, greater doses caused depressive effects on growth of camu-camu plants in the first year of cultivation in firm ground conditions and the indirect measurement of chlorophyll a index in camu-camu plants was suitable for the assessment of nutritional status in relation to N

O DIREITO À CIDADE ARBORIZADA: A ARBORIZAÇÃO URBANA COMO INDICADOR DA SEGREGAÇÃO SOCIOECONÔMICA EM BELÉM DO PARÁ

A constituição de áreas verdes em Belém do Pará sempre esteve associada às dinâmicas socioeconômicas que consolidaram o binômio centro-periferia. Destarte, este estudo relacionou qualitativamente a implantação e manutenção de espaços verdes urbanos aos perfis socioeconômicos da “cidade das mangueiras”, investigando se a arborização planejada estaria associada à dinâmica imobiliária de áreas economicamente atrativas. Metodologicamente, utilizou-se uma compilação de pesquisas sobre a arborização urbana juntamente com registros georreferenciados para constatar a dicotomia socioambiental existente. Os resultados indicaram que áreas centrais possuem sistemas arbóreos planejados e de grande porte, demarcando paisagisticamente territórios elitizados. Ademais, identificou-se que o atual desenvolvimento arbóreo é delineado por interesses imobiliários de capitalização do solo urbano, produzindo espaços verdes como instrumentos de valorização e distinção socioeconômica - fenômeno denominado privilégio verde. Nas periferias, a arborização é não planejada, pontual e arbustiva, dificultando a criação de espaços socioambientais adequados, destacando que a ocorrência arbórea disforme desenvolve problemas de saúde pública, lazer e incompatibilidade com as redes de infraestrutura. Assim, concluiu-se que o direito à cidade arborizada, derivação ecológica da teoria de Lefebvre (1991), distancia-se da realidade belenense ao evidenciar o privilégio verde sobreposto às políticas públicas de bem-estar socioambiental, indicando a concepção de um modelo dicotômico de urbanização