Electromechanical Oscillations in Hydro-Dominant Power Systems: An Application to the Colombian Power System

Power system modeling that captures the dynamic behavior of the different components interacting in an electric grid is useful in understanding some observed phenomena that have not been easy to reproduce by simulation. Therefore, this thesis focuses on the modeling of hydro-dominant power system to study the origin of some very low frequency oscillations (VLFOs) that have not been explained or reproduced; for example, VLFOs in the Colombian Power System have been detected in the 0.05Hz range and their origin have not been clarified. Within this work modeling guidelines for hydro-electric power plants to capture the effects of the hydraulic coupling of turbines, their control strategies, and nonlinearities in the controls and actuators will be developed. This level of modeling will enable to reproduce oscillatory observation by simulation as the ones in the Colombian system for further analysis. Finally, robust control is proposed to damp oscillatory modes to account the effect of the dynamic behavior of coupled systems and nonlinearities in their controls

Full genome analysis of microglial activation; ramifications of TREM2

Neuroinflammation is a pathological hallmark of Alzheimer's disease (AD) and it is well established that microglia, the brain's resident phagocytes, are pivotal for the immune response observed in AD. In the healthy brain, microglia attack and remove pathogens and cell debris, but have been shown to become reactive in AD. An apparent link between microglia and AD is Amyloid β (Aβ), which accumulates in the plaques observed in the brains of AD patients and has been reported as a microglia activator. Genome Wide Association Studies (GWAS) have allowed the identification of more than 20 genetic risk associations to AD. Many of these associations highlight the importance of immune pathways (and others) in AD. More recently, the identification of mutations in TREM2 (Triggering Receptor Expressed on Myeloid Cells 2), a gene exclusively expressed by microglia in the brain, has brought microglial activation and dysfunction back to the attention of the AD community. The main focus of this study is to understand microglial activation elicited by different stimuli including Aβ1-42 monomers, oligomers and fibrils- with regards to their inflammatory activation status (M1, M2 or other) and whole-genome expression profile. To this end, the mouse-derived BV2 cell line was used to assess gene expression changes during microglial activation. Data shows that M1 and M2 activators alter gene expression of AD-associated genes in a manner that is potentially detrimental for AD progression. A second objective of this thesis was to use the CRISPR/Cas9 gene editing technology for the generation of Trem2-deficient BV2 cell lines. As a result, Trem2 +/- (haploinsufficient) and Trem2 -/- (knockout) BV2 cell lines were generated. Subsequently, these cell lines were characterised in terms of their phagocytic, proliferation, migration, cytokine release capacities and whole genome expression. In consequence, this study provides new and wellcharacterised in vitro models for the study of Trem2 function

Mixed-mode impedance and reflection coefficient of two-port devices

From the point of view of mixed-mode scattering parameters, Smm, a two-port device can be excited using different driving conditions. Each condition leads to a particular set of input reflection and input impedance coefficient definitions that should be carefully applied depending on the type of excitation and symmetry of the two-port device. Therefore, the aim of this paper is to explain the general analytic procedure for the evaluation of such reflection and impedance coefficients in terms of mixed-mode scattering parameters. Moreover, the driving of a two-port device as a one-port device is explained as a particular case of a two-port mixed-mode excitation using a given set of mixed-mode loads. The theory is applied to the evaluation of the quality factor, Q, of symmetrical and non- symmetrical inductors.Ministerio de Innovación y Ciencia TEC2010-14825/MIC, TEC2010-21484Junta de Andalucía TIC-253

Seguridad alimentaria, necesidad de implementar técnicas modernas de análisis de xenobióticos en alimentos

Se implementó y evaluó un método para la determinación de Nnitrosodimetilamina (NDMA) en harinas de pescado basado en la extracción de la nitrosamina con acetato de etilo, purificación del extracto por columna de sílicagel y cromatografía de éste en fase gaseosa con detector nitrógeno-fósforo específico (NPD). El método permite detectar la presencia de NDNIA en muestras de harina de pescado en concentraciones tan bajas como 11 partes por billón. El método se aplicó al análisis de 54 :muestras de harina de pescado fabricadas en industrias ubicadas en la VIII Región de Chile. El 17% del total de muestras analizadas presentaron contaminación con NDMA en concentraciones máximas de 45 partes por billón. Además, a estas muestras se les determinó el contenido total de bases Volátiles Nitrogenadas (TBVN), que permite estimar el estado de conservación de la materia prima utilizada en la fabricación de la harina y su contenido de nitratos y nitritos que posibilitan la formación de agentes nitrosantes, Los resultados obtenidos indican que no existe correlación entre estos parámetros y la presencia de NDMA. Esto impide la estimación de la presencia de esta nitrosamina a partir de las mediciones rutinarias de TBVN o de la mayor o menor concentración de las sales mencionadas

18F-FAC PET Visualizes Brain-Infiltrating Leukocytes in a Mouse Model of Multiple Sclerosis.

Brain-infiltrating leukocytes contribute to multiple sclerosis (MS) and autoimmune encephalomyelitis and likely play a role in traumatic brain injury, seizure, and stroke. Brain-infiltrating leukocytes are also primary targets for MS disease-modifying therapies. However, no method exists for noninvasively visualizing these cells in a living organism. 1-(2'-deoxy-2'-18F-fluoroarabinofuranosyl) cytosine (18F-FAC) is a PET radiotracer that measures deoxyribonucleoside salvage and accumulates preferentially in immune cells. We hypothesized that 18F-FAC PET could noninvasively image brain-infiltrating leukocytes. Methods: Healthy mice were imaged with 18F-FAC PET to quantify if this radiotracer crosses the blood-brain barrier (BBB). Experimental autoimmune encephalomyelitis (EAE) is a mouse disease model with brain-infiltrating leukocytes. To determine whether 18F-FAC accumulates in brain-infiltrating leukocytes, EAE mice were analyzed with 18F-FAC PET, digital autoradiography, and immunohistochemistry, and deoxyribonucleoside salvage activity in brain-infiltrating leukocytes was analyzed ex vivo. Fingolimod-treated EAE mice were imaged with 18F-FAC PET to assess if this approach can monitor the effect of an immunomodulatory drug on brain-infiltrating leukocytes. PET scans of individuals injected with 2-chloro-2'-deoxy-2'-18F-fluoro-9-β-d-arabinofuranosyl-adenine (18F-CFA), a PET radiotracer that measures deoxyribonucleoside salvage in humans, were analyzed to evaluate whether 18F-CFA crosses the human BBB. Results: 18F-FAC accumulates in the healthy mouse brain at levels similar to 18F-FAC in the blood (2.54 ± 0.2 and 3.04 ± 0.3 percentage injected dose per gram, respectively) indicating that 18F-FAC crosses the BBB. EAE mice accumulate 18F-FAC in the brain at 180% of the levels of control mice. Brain 18F-FAC accumulation localizes to periventricular regions with significant leukocyte infiltration, and deoxyribonucleoside salvage activity is present at similar levels in brain-infiltrating T and innate immune cells. These data suggest that 18F-FAC accumulates in brain-infiltrating leukocytes in this model. Fingolimod-treated EAE mice accumulate 18F-FAC in the brain at 37% lower levels than control-treated EAE mice, demonstrating that 18F-FAC PET can monitor therapeutic interventions in this mouse model. 18F-CFA accumulates in the human brain at 15% of blood levels (0.08 ± 0.01 and 0.54 ± 0.07 SUV, respectively), indicating that 18F-CFA does not cross the BBB in humans. Conclusion: 18F-FAC PET can visualize brain-infiltrating leukocytes in a mouse MS model and can monitor the response of these cells to an immunomodulatory drug. Translating this strategy into humans will require exploring additional radiotracers

Point-of-interest type inference from social media text

Physical places help shape how we perceive the experiences we have there. For the first time, we study the relationship between social media text and the type of the place from where it was posted, whether a park, restaurant, or someplace else. To facilitate this, we introduce a novel data set of ∼200,000 English tweets published from 2,761 different points-of-interest in the U.S., enriched with place type information. We train classifiers to predict the type of the location a tweet was sent from that reach a macro F1 of 43.67 across eight classes and uncover the linguistic markers associated with each type of place. The ability to predict semantic place information from a tweet has applications in recommendation systems, personalization services and cultural geography

Que Ondee Sola - January 2013

Student publication founded in 1972, articles include: Historical Reflection of a Practioner, Critical Pedagogy Community Building and Self-Determination, Siempre Pa\u27lante: Celebrating 40 Years of Commitment, Greening the Rooftops of Paseo Boricua, A Movement to Empower Young Families, Who was Ferd Eggan?, Dreaming in Ouerto Rican, La Escuelita: Home in Community, Alumni Well Wishes, Somos Fruto de Nuestro Ayer Program, A Few Hours a Week, Student Write to Oscar Lopez, Transformation Through Engagement, Yo Recuerda a Irma, Creating a Decolonizing and Culturally Relevant Curriculum, Living Breathing Solidarity, Sembrando Semillas, Lucha y Resistencia: the Foundations of a Legacyhttps://neiudc.neiu.edu/qos/1339/thumbnail.jp