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A new diffusely infiltrating glioma mouse model reveals neuronal alterations in the brain tumor microenvironment
Gliomas are brain tumors that present with neurological symptoms including seizures and cognitive deficits. Starting at early stages of tumor development glioma cells diffusely infiltrate brain tissue where they interact with non-neoplastic cells including neurons and can perturb normal brain function. While the clinical consequences of glioma induced cortical dysfunction are well established, the neuronal alterations that underlie cortical dysfunction in glioma are unknown. We hypothesize that glioma cells infiltrate surrounding brain tissue and induce alterations in neurons that may contribute to the neurological symptoms associated with gliomas. Due to intermingling of glioma cells and neurons it has been challenging to isolate and characterize neurons from glioma brain tissue while preserving complex neuronal morphology. To address this issue we developed a new mouse glioma model that allowed us to obtain a neuron specific gene expression profile, otherwise obscured by the predominantly large population of glioma cells within the tumor. In this thesis I use this model to test the hypothesis that infiltrating glioma cells induce phenotypic alterations in neurons that contribute to the neurological symptoms associated with glioma.
The Camk2a-Ribotag mouse glioma model enabled us to isolate neuron specific transcripts from glioma brain tissue. The Ribotag mouse has a conditional HA-tagged ribosomal protein (Rpl22) that can be expressed upon Cre-recombination. Camk2a is specifically expressed in excitatory neurons, the Camk2a-Cre mouse induces Cre-recombination in the Ribotag mouse so that Camk2a+ neurons selectively express HA-tagged Rpl22. We used the Camk2a-Ribotag glioma model to isolate neuron specific ribosome bound transcripts to characterize neuronal alterations in glioma.
In chapter 2 of this thesis I describe how we developed and characterized the Camk2a-Ribotag mouse glioma model. We first obtained mouse glioma cells that have p53 deletion and overexpress PDGFRa, then we injected these cells in the Camk2a-Ribotag mouse and use this as our glioma model to extract neuron specific ribosome bound transcripts. This method is referred to as translating ribosome affinity purification (TRAP) which is used to obtain cell type specific translational profiles. Using this approach we identified alterations in neuronal gene expression, specifically we show that there is an upregulation of actin binding genes associated with dendritic spine morphology and a downregulation of synaptic genes associated synaptic regulation. We demonstrate that drebrin, an actin binding protein in dendritic spines, is upregulated in tumor brain synaptosomes, we also show a downregulation of dendritic spine density in HA-tagged neurons which suggests that these neuronal alterations contribute to synaptic dysfunction in our glioma model.
Dendritic spines are dynamic structures that regulate synaptic function in response to diverse stimuli. mTOR signaling can regulate brain specific functions such as synaptic plasticity. Alterations in mTOR signaling can result in cognitive deficits, epilepsy and brain abnormalities that are associated with neurological disease. We hypothesized that mTOR regulates the neuronal alterations we identified in our glioma model. In chapter 3 of this thesis I describe how we tested this hypothesis by acutely inhibiting mTOR signaling with the ATP competitive inhibitor AZD8055 in the Camk2a-Ribotag mouse glioma model. Using TRAP we show that acute mTOR inhibition reverses many neuron specific alterations that occurs in the glioma infiltrated cortex, actin binding genes that were upregulated in tumor brains were downregulated after mTOR inhibition and synaptic genes that were downregulated in tumor brains were upregulated after mTOR inhibition. These results suggest that key neuron specific alterations are regulated by mTOR signaling in our glioma model.
In chapter 4 of this thesis I describe how we used ribosome profiling to identify translational alterations in our Camk2a-Ribotag mouse glioma model. Ribosome profiling in an RNA sequencing based method that is used to measure translation efficiency by calculating the number of ribosomes per transcript. Using this approach we identified an upregulation in the translation of DNA methylation and demethylation gene ontologies. These results suggest that alterations in specific DNA methylation and demethylation gene ontologies are regulated at the level of translation and warrant further analysis of cell type specific translational alterations using ribosome profiling.
The work described in this thesis demonstrates 1) use of the Camk2a-Ribotag mouse glioma model for the identification of neuron specific alterations, 2) neuron specific alterations include the upregulation of dendritic spine genes, downregulation of synaptic genes and downregulation of dendritic spine density, 3) acute mTOR inhibition reverses many of these neuronal alterations, 4) ribosome profiling revealed the translational upregulation of epigenetic genes in our mouse glioma model. The findings described in this thesis provide the first characterization of neuron specific transcriptional and translational alterations in glioma infiltrated cortex that and provide new insights into the mechanisms that underlie the devastating neurological symptoms in glioma patients
The role of visual management in collaborative integrated planning and control for engineer-to-order building systems
Visual Management is a key approach in the implementation of Lean Production. It emphasizes the importance of developing easy-to-understand visual devices for sharing knowledge within an organization. Such visual devices can play an important
role in mitigating the complexity of engineer-to-order production systems. A major difficulty in managing engineer-to-order prefabricated building systems is the need to
integrate planning and control of different processes, such as design, fabrication and assembly on site, in a multiple project environment. This paper reports preliminary findings on the implementation of visual devices for collaborative and integrated
planning and control in a Steel Fabricator, which designs, fabricates and assembles steel structures. The aim of this paper is to understand how visual management tools can contribute to improve the effectiveness of planning and control in this
environment. A set of visual devices have been used in the planning and control system in this company, including a panel that makes available information about 200 simultaneous contracts in an easy-to-understand way. The implementation of those tools has enhanced the participation of different people in the planning process from operational levels or from the different production units
Cooling Water for pre-commissioning Operations in Subsea Fields
Pre-commissioning in subsea oil and gas fields ensures the readiness for operation and integrity of the valves, pipelines, and various components installed on the seabed. A critical task in this process is the pressure testing of pipelines, which involves flooding them with fluids such as freshwater, seawater, or water-glycol mixtures. The testing fluid, initially stored in vessel tanks, is typically at ambient temperature. The high insulation in the subsea pipelines creates a significant temperature difference between the internal fluid used for pressure testing and the pipeline surroundings. This condition creates a false impression of pressure decrease due to temperature stabilization. Consequently, it becomes challenging to accurately identify leakages during pressure testing, resulting in prolonged offshore campaigns.
This study aims to investigate different solutions for efficiently cooling large amounts of water within a reasonable time frame under different spread configuration cases. Five different alternatives were studied: 1) Installation of a subsea spool with low insulation to allow for natural and forced convection cooling from the sea currents. 2) Single heat exchanger on the vessel deck. 3) Water chiller on the vessel deck. 4) Producing seawater using a desalination system and pumping the water from the seabed. 5) Theoretical reviews of developed patents for subsea heat exchangers.
Heat transfer calculations indicate the first two alternatives won't cover the objectives. First, The required length of the spool piece renders this alternative unfeasible. As for the heat exchanger, using seawater as a cold fluid limits the process final temperature. Two technologies are found to be more suitable for this application due to their extensive utilization in marine applications. First, the installation of a system similar to an RSW chiller, commonly used in fishing vessels to cool seawater and preserve the catch. Capacity calculations for this project result in average ranges for this type of equipment. Alternatively, the installation of a desalination system provides a different approach to the problem, however, the outlet temperature of the water is limited to the minimum achievable seawater temperature, which, in turn, is restricted by the capacity and installed depth of a subsea pump.
Considering the advantages of using a chiller system on a vessel, an economic evaluation was performed using quotations for this system. The interviewed providers offered the option to purchase the system instead of renting when compared to the assumed daily rate of a diving vessel, acquiring a unit like this becomes profitable. The initial investment can even be recouped in a single project, and operational time in offshore campaigns will be significantly reduced while decreasing at the same time the company's CO2 emissions
National innovation system, competitiveness and economic growth
Differences in income-elasticities of imports and exports among countries bring about distinct degrees of external constraints to growth. This argument has been pointed out by Prebisch and by authors in the Kaldorian tradition. Prebisch’s explanations for this phenomenon relate to the differences in international insertion between agrarian / peripheral and industrial / central economies. Kaldorian authors, in turn, refer to Prebisch only to explain why such elasticities differ between products and between countries. However, even after undergoing industrialization processes, several economies still face external constraints to growth. The aim of this paper is to explain differences in trade elasticities among industrial economies. Therefore, it intends to demonstrate, by using the Neo-Schumpeterian literature, the causal relations between the development of a National Innovation System, the differences in income-elasticities of imports and exports, the degree of competitiveness and the degree of external vulnerability of an economy.national innovation system, competitiveness, external vulnerability
In vitro generation of human innate lymphoid cells from CD34+ hematopoietic progenitors recapitulates phenotype and function of ex vivo counterparts
Angeborene lymphatische Zellen (ILC) sind wichtige Effektorzellen der angeborenen Immunantwort, deren Entwicklung und Aktivierungswege attraktive therapeutische Ziele darstellen. Sie bestehen aus ILC der Gruppe 1 (Natürliche Killerzellen (NK) und ILC1), ILC2 und ILC3. Neben T-Zellen leisten ILCs einen entscheidenen Beitrag zu den Typ-1-, Typ-2- und Typ-3-Immunantworten. Die Entwicklung von ILCs beim Menschen wurde jedoch noch nicht systematisch untersucht, und frühere in vitro Untersuchungen stützten sich auf die Analyse einiger weniger Marker oder Zytokine, die für die Bestimmung der Identität der verschiedenen ILC-Linien suboptimal sind. Um diese Mängel zu beheben, stellen wir hier eine Plattform vor, die zuverlässig alle menschlichen ILC-Linien aus CD34+ CD45RA+ hämatopoetischen Vorläuferzellen, gewonnen aus Nabelschnurblut und Knochenmark, erzeugt. Mit einem systematischen Ansatz zeigt diese Arbeit, dass eine einzige Kulturbedingung nicht ausreicht, um alle ILC-Untergruppen zu generieren, sondern stattdessen bestimmte Kombinationen von Zytokinen und Notch-Signalen für die Entscheidung über das Schicksal der Linien wesentlich ist. Eine umfangreiche Analyse des Transkriptoms ergab, dass der Erwerb von CD161 robust eine globale ILC-Signatur identifiziert und in vitro ILCs von T-Zell-Signaturen trennt. Die Identität spezifischer in vitro generierter ILC-Linien (NK-Zellen und ILC1, ILC2 und ILC3) wurde durch Proteinexpression, funktionelle Assays und Transkriptomanalysen auf globaler sowie auf Einzelzellebene umfassend validiert. Diese in vitro erzeugten ILC-Linien rekapitulieren die Signaturen und Funktionen ihrer ex vivo isolierten ILC-Pendants. Des Weiteren, behandeln diese Daten die Einschränkungen der Unterscheidung von menschlichen NK Zellen und ILC1 sowohl in vitro als auch ex vivo an. Darüber hinaus löst diese Plattform gängige Probleme bei der Untersuchung menschlicher ILCs, wie z. B. unzureichende Zellzahlen oder die mangelnde Verfügbarkeit von Gewebeproben. Insgesamt stellt diese Arbeit eine Ressource dar, die nicht nur zur Klärung der Biologie und Differenzierung menschlicher ILCs beiträgt, sondern auch als wichtiges Instrument zur Untersuchung der Dysregulation von ILC-Funktionen dient, die bei verschiedenen entzündlichen Erkrankungen des Menschen eine Rolle spielen.Innate lymphoid cells (ILCs) are critical effectors of innate immunity and inflammation that consist of Group 1 ILCs (natural killer (NK) cells and ILC1), ILC2, and ILC3. As tissue resident lymphocytes, they play a crucial role type 1, type 2 and type 3 immune responses, respectively. Importantly, dysregulated ILC populations have been linked to the pathogenesis of a variety of chronic inflammatory diseases and thus represent attractive therapeutic targets with a potential for autologous cell therapies. However, human ILC generation has not been systematically explored, and previous in vitro investigations have relied on the analysis of few markers or cytokines, which are suboptimal to assign lineage identity and full functional capacity. To address these faults, we present here an effective in vitro platform, which reliably generates the core human ILC lineages from CD34+ CD45RA+ hematopoietic progenitors derived from cord blood and bone marrow. With a systematic approach, this work shows that a single culture condition is insufficient to generate all ILC subsets, and instead, distinct combinations of cytokines and Notch signaling are essential for lineage fate making decisions. In depth transcriptomic analysis revealed that acquisition of CD161 robustly identifies a global ILC signature and separates them from T cell signatures in vitro. The identity of specific ILC subsets, (NK cells and ILC1, ILC2, and ILC3) generated in vitro was validated extensively by protein expression, functional assays, and both global and single-cell transcriptome analysis. These in vitro generated ILC subsets recapitulate the signatures and functions of their ex vivo ILC counterparts. Finally, these data shed light on the limitations in untying the identity of human NK cells and ILC1 in vitro, similarly correlating to lineage identification difficulties ex vivo. Additionally, this platform tackles common problems in human ILC studies such as insufficient cell numbers and scarce availability of tissue samples. Altogether, this work presents a resource not only to aid in clarifying human ILC biology and differentiation, but also to serve as an important tool to study dysregulation of ILC functions, which have been implied in various inflammatory diseases in humans
Master of Arts
thesisThis study offers a test of the cognitive mediation model (CMM) within a low-income, Spanish-speaking population in the state of Indiana. A survey study was conducted to test whether participants (N = 150) who consumed ethnic newspapers, namely La Raza, were more likely to have greater cancer prevention knowledge and more likely to comply with cancer prevention behaviors. The interaction between La Raza readership and health motivation was not significantly related to either screening or knowledge; however, individuals with high health motivation were more likely to report screening. Notably, two of the relationships posited by the CMM were absent, surveillance motivation and elaboration were not related to knowledge. Further, our test of the model did not yield any significant results in its original form or the modified version used to test an ethnic subsample in a health news learning context. However, once elaboration was removed from the model, there was an indirect relationship between surveillance motivation and cancer prevention knowledge through attention. Future research should focus on finding ways in which models such as the CMM can be modified to explain news learning in ethnic and linguistic subpopulations
Análisis de una muestra de concreto de 4000 psi sintetizada a partir de suelo diatomáceo con activación alcalina
Trabajo de investigaciónSe ha querido investigar a partir de la composición química de la Diatomea, el reemplazo en un 100% del CP evaluando sus propiedades mecánicas. Se investigó acerca de los materiales químicamente. Se analizó la composición química tanto del CP como el de la Diatomea y a partir de esto se realizó un diseño de la composición química de la diatomea similar a la del CP. Se realizaron en total 15 muestras para ser ensayadas en el laboratorio donde se realizaron los ensayos de flexión y compresión de muestras de Concreto según normatividad INV 410-13 y 415-13 y así mismo para mortero se realizaron ensayos de Compresión según normatividad NTC 220.RESUMEN
GLOSARIO
1. INTRODUCCIÓN
2. ANTECEDENTES Y JUSTIFICACIÓN
3. PLANTEAMIENTO Y FORMULACIÓN DEL PROBLEMA
4. OBJETIVOS
5. ALCANCES Y LIMITACIONES
6. ESTADO DEL ARTE.
7. MARCO TEÓRICO
8. MARCO LEGAL
9. METODOLOGÍA
10. DESARROLLO DE LA INVESTIGACIÓN
11. RESULTADOS Y ANÁLISIS
12. CONCLUSIONESPregradoIngeniero Civi
Evaluación de los impactos ambientales generados a partir del establecimiento y operación del Centro de Recuperación y Regeneración de Gases Refrigerantes del eje cafetero en el municipio de Dosquebradas Risaralda
Colombia, como país firmante del Protocolo de Montreal se ha propuesto diferentes objetivos necesarios para lograr la disminución del consumo de SAO (sustancias agotadoras de ozono) en su territorio, en especial el consumo relacionado con refrigerantes de la familia de los CFC. La refrigeración hace parte hoy de las principales cadenas de consumo y se convierte en un renglón importante de la economía nacional. En medio de esta dinámica, surgen los técnicos como actores principales en la conservación, el mantenimiento y la reparación de los aparatos refrigeradores.
El sector del servicio técnico y mantenimiento en refrigeración reporta, en Colombia, los mayores índices de consumo de CFC asociado con las necesidades propias de su oficio pero también con la práctica de procedimientos incorrectos y la ausencia de mecanismos eficaces para permitir la recuperación y reciclaje de los refrigerantes. De esta manera surge el establecimiento del CRRR-EC como alternativa para disminuir la liberación de gases refrigerantes a la atmosfera pero también para cubrir la demanda de los refrigerantes R134a y R-22 cuando la oferta en el mercado sea baja y reducir el consumo de refrigerante virgen, haciendo de la regeneración una herramienta económica y eficaz. Los servicios prestados por el centro se basan en la recuperación con una unidad móvil, la regeneración, las pruebas de calidad en laboratorio, asistencia técnica y capacitación. Por lo anterior se hace necesaria la realización de una evaluación de los impactos ambientales positivos y negativos que puedan generarse a partir del establecimiento y operación del CRRR-EC. Dicha EIA consiste en caracterizar cada una de las actividades y procesos que se ejecutan en el centro llevando a cabo la identificación, análisis y calificación de los aspectos e impactos ambientales presentes para posteriormente proponer medidas de manejo ambiental que permitan prevenir y mitigar las consecuencias negativas como también realizar seguimiento y monitoreo a las acciones positivas con el fin de maximizar su beneficio
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