Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2020 ( 3 )

2019 ( 6 )

2018 ( 14 )

2017 ( 5 )

Custom range...

Search Results: 1 - 10 of 7642 matches for " Jaime Pineda "
All listed articles are free for downloading (OA Articles)
Page 1 /7642
Display every page Item
Sensorimotor cortex as a critical component of an 'extended' mirror neuron system: Does it solve the development, correspondence, and control problems in mirroring?
Jaime A Pineda
Behavioral and Brain Functions , 2008, DOI: 10.1186/1744-9081-4-47
Abstract: Human beings are social creatures to the extent that interactions with members of their own species, and especially the ability to understand and infer the intentions and beliefs of others, has become of predominant importance in their daily life. Whether for cooperation or non-cooperation, a core assumption of this viewpoint is that such social interactions spring from a distinction between self and others. It can be argued that at least two hierarchically-organized, overlapping and interacting neural systems have evolved and developed to manage self-other distinctions and hence social interactions [1]. One system, part of the classic motor system, is more specialized for the preparation and execution of motor actions that are self realized and voluntary, while the other appears to be more involved in capturing and understanding, at a basic and involuntary level, the actions of non-self or others. For our purposes, actions are defined as sequences of movements that together solve a motor problem [2] and that involve at least four levels of behavioral complexity: intention, kinematics, goal-object identity, and the physical consequences of the action [1]. Motor preparation and execution circuitry includes, among others, the premotor cortex, supplementary motor area, sensorimotor cortices, and parts of the inferior parietal cortex. The second system, of which the mirror neuron system (MNS) is part, has been described as the canonical action 'resonance' system in the brain – one that has evolved to utilize or share many of the same circuits involved in motor control [3]. Mirroring or 'shared circuit' systems are assumed to be important for resonating, imitating, and/or simulating the actions of others. Although no consensus exists, a number of researchers have proposed that shared representations of motor actions, or the action understanding properties of this system, may form a foundational cornerstone for higher order social processes, including motor learning, acti
Neuroanthropology: Olfactory Recognition of the Self / Non-self by the Ancestral MHC: An EEG Study
Emma Marxer-Tobler,Jaime Pineda
International Journal of Biology , 2012, DOI: 10.5539/ijb.v4n4p1
Abstract: Humans naturally discriminate between different ethnic group members using visual and other sensory information, including the sense of smell. The genetic diversity of humans serves as biological and social sign stimuli in the neural self/non-self recognition process. As already evident, the major histocompatibility complex (MHC) encodes both an individual self and a shared ancestral self into the body odor. In a pilot study, we examine the brain-evoked responses to ancestral encoded body odors by conducting an olfactory EEG recording of four different groups: Germans, Taiwanese, Koreans, and Chinese. Results show that humans recognize in-group members as familiar and they exhibit practically identical rhythmic EEG patterns to one’s own odor as it pertains to the ancestral in-group odors. This reveals their genetic relatedness. It is hereby demonstrated that shared ethnicity results in behaviors (both group-protective and pro-social) that are important to intra- and inter-group dynamics.
Spokes cluster: The search for the quiescent gas
Jaime E Pineda,Paula S. Teixeira
Physics , 2013, DOI: 10.1051/0004-6361/201220861
Abstract: Context. Understanding the role of fragmentation is one of the most important current questions of star formation. To better understand the process of star and cluster formation, we need to study in detail the physical structure and properties of the parental molecular cloud. The Spokes cluster, or NGC 2264 D, is a rich protostellar cluster where previous N2H+(1-0) observations of its dense cores presented linewidths consistent with supersonic turbulence. However, the fragmentation of the most massive of these cores appears to have a scale length consistent with that of the thermal Jeans length, suggesting that turbulence was not dominant. Aims. These two results probe different density regimes. Our aim is to determine if there is subsonic or less-turbulent gas (than previously reported) in the Spokes cluster at higher densities. Methods. We present APEX N2H+(3-2) and N2D+(3-2) observations of the NGC2264-D region to measure the linewidths and the deuteration fraction of the higher density gas. The critical densities of the selected transitions are more than an order of magnitude higher than that of N2H+(1-0). Results. We find that the N2H+(3-2) and N2D+(3-2) emission present significantly narrower linewidths than the emission from N2H+(1-0) for most cores. In two of the spectra, the nonthermal component is close (within 1-sigma) to the sound speed. In addition, we find that the three spatially segregated cores, for which no protostar had been confirmed show the highest levels of deuteration. Conclusions. These results show that the higher density gas, probed with N2H+ and N2D+(3-2), reveals more quiescent gas in the Spokes cluster than previously reported. More high-angular resolution interferometric observations using high-density tracers are needed to truly assess the kinematics and substructure within NGC2264-D. (Abridged)
Minimal HCN emission from Molecular Clouds in M33
Erik Rosolowsky,Jaime Pineda,Yu Gao
Physics , 2011, DOI: 10.1111/j.1365-2966.2011.18851.x
Abstract: Since HCN emission has been shown to be a linear tracer of ongoing star formation activity, we have searched for HCN (J = 1->0) emission from known GMCs in the nearby galaxy M33. No significant HCN emission has been found along any of the lines of sight. We find two lines of sight where CO-to-HCN integrated intensity ratios up to 280, nearly a factor of 6 above what is found in comparable regions of the Milky Way. Star formation tracers suggest that the HCN-to-star formation rate ratio (L_HCN/M_SFR) is a factor of six lower than what is observed in the Milky Way (on average) and local extragalactic systems. Simple chemical models accounting for the sub-solar N/O ratio suggest that depletion cannot account for the high CO-to-HCN ratios. Given HCN formation requires high extinction (A_V > 4), low metallicity may yield reduced dust shielding and thus a high CO/HCN ratio. The turbulence and structure of GMCs in M33 are comparable to those found in other systems, so the differences are unlikely to result from different GMC properties. Since lower CO-to-HCN ratios are associated with the highest rates of star formation, we attribute the deficits in part to evolutionary effects within GMCs.
Diferencias en la agregación plaquetaria de sangre coronaria y periférica de pacientes con enfermedad coronaria: Implicaciones clínicas
Cabrales,Jaime; Echeverri,Darío; Corzo,Orlando; Pineda,Mauricio;
Revista Colombiana de Cardiología , 2010,
Abstract: introduction: thrombotic events are more frequent in the coronary arteries and apparently the changes in rheology and endothelial surface produced by atheroesclerotic disease are responsible for this phenomenon. objetive: quantify the difference in platelet aggregation of coronary venous blood and peripheral venous blood in patients with severe coronary disease. methodology: we selected patients older than 30 years with severe coronary disease and obtained samples of peripheral and coronary sinus blood. platelet aggregation was realized by the absorbance method with adp 10 mmol, arachidonic acid (aa), epinephrine (epi) 300 mmol and collagen 10 ug/ml. results: we included a total of 32 patients with mean age 65 ± 10 years. 22 were men; 10 patients (31%) had stable disease and 22 (69%) unstable disease. platelet aggregation in coronary sinus blood was higher with all agonists used as follows: adp 61.8% vs. 53.4% (p = 0.001), aa 15.1% vs.13.8% (p = 0.48), collagen 72.6% vs. 69.2% (p = 0.048) and epi 58% vs. 51.6% (p = 0.01). patients with unstable disease show increased aggregation with adp in the coronary sinus 58.5% vs. 49.2% (p = 0.001) and there are no differences in the unstable. aspirin resistance was similar (p = 1); however, clopidogrel resistance was higher in the coronary sinus 56% vs. 48% (p = 0.24). conclusion: we describe the presence of higher platelet aggregation in the coronary sinus of patients with atheroesclerotic disease that is significant for adp, collagen and epinephrine, and suggest the appearance of local factors associated with the coronary disease that increase platelet aggregation. peripheral platelet aggregation doesn't reflect the local behavior in patients with coronary atheroesclerosis.
Diferencias en la agregación plaquetaria de sangre coronaria y periférica de pacientes con enfermedad coronaria: Implicaciones clínicas Differences in platelet aggregation in coronary and peripheral blood of patients with coronary disease: Clinical implications
Jaime Cabrales,Darío Echeverri,Orlando Corzo,Mauricio Pineda
Revista Colombiana de Cardiología , 2010,
Abstract: INTRODUCCIóN: los fenómenos trombóticos son más frecuentes en las coronarias y, al parecer, los cambios que produce la enfermedad aterosclerótica en la reología y en la superficie endotelial son los responsables de este fenómeno. OBJETIVO: cuantificar la diferencia en la agregación plaquetaria de sangre venosa coronaria y sangre venosa periférica en pacientes con enfermedad coronaria severa. METODOLOGíA: se seleccionaron pacientes mayores de treinta a os, con enfermedad coronaria severa, de quienes se obtuvieron muestras de sangre periférica y del seno coronario, y se realizaron agregaciones plaquetarias por el método de absorbancia con ADP 10 mmol, ácido araquidónico (AA), epinefrina (Epi) 300 mmol y colágeno 10 mg/mL. RESULTADOS: se incluyeron en total 32 pacientes con edad promedio de 65 ± 10 a os, 22 hombres, 10 (31%) pacientes con enfermedad estable y 22 (69%) con inestable. La agregación plaquetaria en sangre del seno coronario fue mayor con todos los agonistas usados, así: ADP 61,8% vs. 53,4% (p= 0,001), AA 15,1% vs. 13,8% (p= 0,48), colágeno 72,6% vs. 69,2% (p= 0,048) y Epi 58% vs. 51,6% (p= 0,01). Los pacientes con enfermedad inestable muestran una mayor agregación con ADP en el seno coronario: 58,5% vs. 49,2% (p= 0,001) y no hay diferencias en los inestables. La resistencia a la Aspirina fue similar (p= 1), sin embargo la resistencia al clopidogrel fue mayor en el seno coronario: 56% vs. 48% (p= 0,24). CONCLUSIóN: se describe la presencia de mayor agregación plaquetaria en el seno coronario de pacientes con enfermedad aterosclerótica, la cual es significativa para ADP, colágeno y epinefrina. Se sugiere la aparición de factores locales asociados con la enfermedad coronaria que aumentan la agregación plaquetaria. La agregación plaquetaria periférica no refleja el comportamiento local en pacientes con aterosclerosis coronaria. INTRODUCTION: thrombotic events are more frequent in the coronary arteries and apparently the changes in rheology and endothelial surface produced by atheroesclerotic disease are responsible for this phenomenon. OBJETIVE: quantify the difference in platelet aggregation of coronary venous blood and peripheral venous blood in patients with severe coronary disease. METHODOLOGY: we selected patients older than 30 years with severe coronary disease and obtained samples of peripheral and coronary sinus blood. Platelet aggregation was realized by the absorbance method with ADP 10 mmol, arachidonic acid (AA), epinephrine (Epi) 300 mmol and collagen 10 ug/mL. RESULTS: we included a total of 32 patients with mean age 65 ± 10 years. 22
Coartación de aorta en adulto Aortic coarctation in adults
Jaime Cabrales,Darío Echeverri,Mauricio Pineda,Orlando Corzo
Acta Medica Colombiana , 2007,
Neurorehabilitation of social dysfunctions: a model-based neurofeedback approach for low and high-functioning autism
Jaime A. Pineda,Elisabeth V. C. Friedrich,Kristen LaMarca
Frontiers in Neuroengineering , 2014, DOI: 10.3389/fneng.2014.00029
Abstract: Autism Spectrum Disorder (ASD) is an increasingly prevalent condition with core deficits in the social domain. Understanding its neuroetiology is critical to providing insights into the relationship between neuroanatomy, physiology and social behaviors, including imitation learning, language, empathy, theory of mind, and even self-awareness. Equally important is the need to find ways to arrest its increasing prevalence and to ameliorate its symptoms. In this review, we highlight neurofeedback studies as viable treatment options for high-functioning as well as low-functioning children with ASD. Lower-functioning groups have the greatest need for diagnosis and treatment, the greatest barrier to communication, and may experience the greatest benefit if a treatment can improve function or prevent progression of the disorder at an early stage. Therefore, we focus on neurofeedback interventions combined with other kinds of behavioral conditioning to induce neuroplastic changes that can address the full spectrum of the autism phenotype.
The Perils of Clumpfind: The Mass Spectrum of Sub-structures in Molecular Clouds
Jaime E. Pineda,Erik W. Rosolowsky,Alyssa A. Goodman
Physics , 2009, DOI: 10.1088/0004-637X/699/2/L134
Abstract: We study the mass spectrum of sub-structures in the Perseus Molecular Cloud Complex traced by 13CO (1-0), finding that $dN/dM\propto M^{-2.4}$ for the standard Clumpfind parameters. This result does not agree with the classical $dN/dM\propto M^{-1.6}$. To understand this discrepancy we study the robustness of the mass spectrum derived using the Clumpfind algorithm. Both 2D and 3D Clumpfind versions are tested, using 850 $\mu$m dust emission and 13CO spectral-line observations of Perseus, respectively. The effect of varying threshold is not important, but varying stepsize produces a different effect for 2D and 3D cases. In the 2D case, where emission is relatively isolated (associated with only the densest peaks in the cloud), the mass spectrum variability is negligible compared to the mass function fit uncertainties. In the 3D case, however, where the 13CO emission traces the bulk of the molecular cloud, the number of clumps and the derived mass spectrum are highly correlated with the stepsize used. The distinction between "2D" and "3D" here is more importantly also a distinction between "sparse" and "crowded" emission. In any "crowded" case, Clumpfind should not be used blindly to derive mass functions. Clumpfind's output in the "crowded" case can still offer a statistical description of emission useful in inter-comparisons, but the clump-list should not be treated as a robust region decomposition suitable to generate a physically-meaningful mass function. We conclude that the 13CO mass spectrum depends on the observations resolution, due to the hierarchical structure of MC.
The Dynamics of Dense Cores in the Perseus Molecular Cloud II: The Relationship Between Dense Cores and the Cloud
Helen Kirk,Jaime E. Pineda,Doug Johnstone,Alyssa Goodman
Physics , 2010, DOI: 10.1088/0004-637X/723/1/457
Abstract: We utilize the extensive datasets available for the Perseus molecular cloud to analyze the relationship between the kinematics of small-scale dense cores and the larger structures in which they are embedded. The kinematic measures presented here can be used in conjunction with those discussed in our previous work as strong observational constraints that numerical simulations (or analytic models) of star formation should match. We find that dense cores have small motions with respect to the 13CO gas, about one third of the 13CO velocity dispersion along the same line of sight. Within each extinction region, the core-to-core velocity dispersion is about half of the total (13CO) velocity dispersion seen in the region. Large-scale velocity gradients account for roughly half of the total velocity dispersion in each region, similar to what is predicted from large-scale turbulent modes following a power spectrum of P(k) ~ k^{-4}.
Page 1 /7642
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.