Search results for "Ostas"
showing 10 items of 874 documents
Liver X receptor activation promotes polyunsaturated fatty acid synthesis in macrophages : relevance in the context of atherosclerosis
2015
Objective— Liver X receptors (LXRs) modulate cholesterol and fatty acid homeostasis as well as inflammation. This study aims to decipher the role of LXRs in the regulation of polyunsaturated fatty acid (PUFA) synthesis in macrophages in the context of atherosclerosis. Approach and Results— Transcriptomic analysis in human monocytes and macrophages was used to identify putative LXR target genes among enzymes involved in PUFA biosynthesis. In parallel, the consequences of LXR activation or LXR invalidation on PUFA synthesis and distribution were determined. Finally, we investigated the impact of LXR activation on PUFA metabolism in vivo in apolipoprotein E–deficient mice. mRNA levels of acyl…
Individual Variations and Coping Style
2020
By current definition, animal welfare depends on the subjective experience of cognitive and emotional processes that are engendered as individuals succeed or fail in coping with a dynamically changing environment. A functional and evolutionary approach to emotion holds that adaptive qualities such as duration, severity, controllability, and predictability of stressful stimuli determine whether a particular event or outcome is experienced as rewarding or adverse. For instance, stress-induced behavioral inhibition can be seen as an adaptive strategy during chronic, unpredictable, or uncontrollable conditions that do not merit successful active coping. In teleost fishes, such behavior can be t…
The frequent stressor and mental health monitoring-paradigm: a proposal for the operationalization and measurement of resilience and the identificati…
2021
Resilience has been defined as the maintenance or quick recovery of mental health during and after times of adversity. How to operationalize resilience and to determine the factors and processes that lead to good long-term mental health outcomes in stressor-exposed individuals is a matter of ongoing debate and of critical importance for the advancement of the field. One of the biggest challenges for implementing an outcome-based definition of resilience in longitudinal observational study designs lies in the fact that real-life adversity is usually unpredictable and that its substantial qualitative as well as temporal variability between subjects often precludes defining circumscribed time …
Hidden oscillations in SPICE simulation of two-phase Costas loop with non-linear VCO
2016
Simulation is widely used for analysis of Costas loop based circuits. However it may be a non-trivial task, because incorrect choice of integration parameters may lead to qualitatively wrong conclusions. In this work the importance of choosing appropriate parameters and simulation model is discussed. It is shown that hidden oscillations may not be found by simulation in SPICE, however it can be predicted by analytical methods. peerReviewed
Nonlinear dynamical model of Costas loop and an approach to the analysis of its stability in the large
2015
The analysis of the stability and numerical simulation of Costas loop circuits for highfrequency signals is a challenging task. The problem lies in the fact that it is necessary to simultaneously observe very fast time scale of the input signals and slow time scale of phase difference between the input signals. To overcome this difficult situation it is possible, following the approach presented in the classical works of Gardner and Viterbi, to construct a mathematical model of Costas loop, in which only slow time change of signal's phases and frequencies is considered. Such a construction, in turn, requires the computation of phase detector characteristic, depending on the waveforms of the…
Nonlinear dynamical model of Costas loop and an approach to the analysis of its stability in the large
2015
The analysis of the stability and numerical simulation of Costas loop circuits for high-frequency signals is a challenging task. The problem lies in the fact that it is necessary to simultaneously observe very fast time scale of the input signals and slow time scale of phase difference between the input signals. To overcome this difficult situation it is possible, following the approach presented in the classical works of Gardner and Viterbi, to construct a mathematical model of Costas loop, in which only slow time change of signal?s phases and frequencies is considered. Such a construction, in turn, requires the computation of phase detector characteristic, depending on the waveforms of th…
Physiological Micromechanics of the Anterior Mitral Valve Leaflet
2011
An improved understanding of mitral valve (MV) function remains an important goal for determining mechanisms underlying valve disease and for developing novel therapies. Critical to heart valve tissue homeostasis is the valvular interstitial cells (VICs), which reside in the interstitium and maintain the extracellular matrix (ECM) through both protein synthesis and enzymatic degradation [1]. There is scant experimental data on the alterations of the MV fiber network reorganization as a function of load, which is critical for implementation of computational strategies that attempt to link this meso-micro scale phenomenon. The observed large scale deformations experienced by VICs could be imp…
III Foro de Cultura y Naturaleza. Dossier de prensa
2000
Es un dossier de prensa con varios artículos de distintos diarios sobre el "III Foro de Cultura y Naturaleza", coordinado por José Vidal-Beneyto y celebrado en Santander del 14 al 16 de septiembre del 2000. Se incluye una entrevista a Vidal-Beneyto realizada por Javier Sakona y publicada en "La Realidad", en su edición del 25 de septiembre al 1 de octubre del 2000.
Autophagy as a rescue mechanism in efavirenz-induced mitochondrial dysfunction: a lesson from hepatic cells.
2011
Efavirenz (EFV) is the most widely used non-nucleoside reverse transcriptase inhibitor applied in highly active antiretroviral therapy (HAART), the combined pharmacological treatment of the human immunodeficiency virus infection. Its use has been associated with the development of several adverse events including hepatotoxicity. The molecular pathogenesis of this effect is poorly understood but recent reports have highlighted features of mitochondrial dysfunction in hepatic cells exposed to clinically relevant concentrations of EFV. In this study, we investigated the activation of autophagy and, in particular, mitophagy, in human hepatic cells exposed to EFV. We detected the presence of alt…
Differential salinity-induced variations in the activity of H+-pumps and Na+/H+ antiporters that are involved in cytoplasm ion homeostasis as a funct…
2011
The characterisation of cellular responses to salinity in staple crops is necessary for the reliable identification of physiological markers of salinity tolerance. Under saline conditions, variations in proton gradients that are generated by membrane-bound H⁺ pumps are crucial for maintaining cytoplasm homeostasis. We examined short (15 h) and longer term effects (4 days) of NaCl stress on the H⁺ pumping activities that are associated with the plasma membrane (P-ATPase) and the tonoplast (V-ATPase and V-PPase) in rice (Oryza sativa L.) callus lines that displayed different levels of NaCl tolerance and were established from two japonica rice cultivars. The applied stress conditions were base…