Una aproximación a las representaciones y prácticas de la escena del rock post Cromañón

El rock nacional es desde hace varias décadas objeto de investigación de la sociología de la cultura. En efecto, éste se ha constituido en un espacio privilegiado para explorar las prácticas y representaciones de grupos etarios y clases sociales. A esta altura, podríamos decir que ya existe una historia y una serie de conceptos más o menos consagrados por ese corpus de la bibliografía que ha estudiado el rock nacional guiado por el interés de conocer los procesos de transformación de la cultura y la sociedad. El 30 de diciembre del 2004, en la ciudad de Buenos Aires, se produjo un acontecimiento que muchos especialistas consideran un punto de inflexión en la historia de una de las vertientes del rock local: el incendio en el boliche República de Cromañón mientras una banda de rock barrial realizaba un recital. Esa noche se produjo la muerte de ciento noventa y cuatro personas. A raíz de lo sucedido, se abrieron varios debates. Algunos en torno a la pirotecnia utilizada en los recitales de éste tipo de rock y a las prácticas de los jóvenes dentro de éstos espacios; otros en relación a la negligencia del Estado; a la irresponsabilidad del dueño del boliche; a las responsabilidades políticas, entre otros. Sin embargo, nuestro interés no es tallar en esa discusión desde la opinión más o menos experta, sino explorar cómo se relaciona ese acontecimiento con las prácticas y representaciones de determinados agentes sociales que ayudan a producir esa vertiente del rock denominada rock chabón. Con datos recogidos en entrevistas en profundidad dirigidas a un universo pequeño pero variado de actores del campo rock, intentamos explorar los primeros indicios que nos muestran que efectivamente algunos cambios parecen estar produciéndose, aunque como veremos a lo largo de la tesina, esas modificaciones no son elaboradas y categorizadas de la misma manera por los distintos sujetos que investigamos. Es en la variedad de los procesos reflexivos de los actores frente a la conmoción de un acontecimiento como el de "Cromañón", donde intentamos buscar esos indicios, antes que en la opinión fundada o no de especialistas, críticos o artistas consagrados

Una aproximación a las representaciones y prácticas de la escena del rock post Cromañón

El rock nacional es desde hace varias décadas objeto de investigación de la sociología de la cultura. En efecto, éste se ha constituido en un espacio privilegiado para explorar las prácticas y representaciones de grupos etarios y clases sociales. A esta altura, podríamos decir que ya existe una historia y una serie de conceptos más o menos consagrados por ese corpus de la bibliografía que ha estudiado el rock nacional guiado por el interés de conocer los procesos de transformación de la cultura y la sociedad. El 30 de diciembre del 2004, en la ciudad de Buenos Aires, se produjo un acontecimiento que muchos especialistas consideran un punto de inflexión en la historia de una de las vertientes del rock local: el incendio en el boliche República de Cromañón mientras una banda de rock barrial realizaba un recital. Esa noche se produjo la muerte de ciento noventa y cuatro personas. A raíz de lo sucedido, se abrieron varios debates. Algunos en torno a la pirotecnia utilizada en los recitales de éste tipo de rock y a las prácticas de los jóvenes dentro de éstos espacios; otros en relación a la negligencia del Estado; a la irresponsabilidad del dueño del boliche; a las responsabilidades políticas, entre otros. Sin embargo, nuestro interés no es tallar en esa discusión desde la opinión más o menos experta, sino explorar cómo se relaciona ese acontecimiento con las prácticas y representaciones de determinados agentes sociales que ayudan a producir esa vertiente del rock denominada rock chabón. Con datos recogidos en entrevistas en profundidad dirigidas a un universo pequeño pero variado de actores del campo rock, intentamos explorar los primeros indicios que nos muestran que efectivamente algunos cambios parecen estar produciéndose, aunque como veremos a lo largo de la tesina, esas modificaciones no son elaboradas y categorizadas de la misma manera por los distintos sujetos que investigamos. Es en la variedad de los procesos reflexivos de los actores frente a la conmoción de un acontecimiento como el de "Cromañón", donde intentamos buscar esos indicios, antes que en la opinión fundada o no de especialistas, críticos o artistas consagrados

Una aproximación a las representaciones y prácticas de la escena del rock post Cromañón

El rock nacional es desde hace varias décadas objeto de investigación de la sociología de la cultura. En efecto, éste se ha constituido en un espacio privilegiado para explorar las prácticas y representaciones de grupos etarios y clases sociales. A esta altura, podríamos decir que ya existe una historia y una serie de conceptos más o menos consagrados por ese corpus de la bibliografía que ha estudiado el rock nacional guiado por el interés de conocer los procesos de transformación de la cultura y la sociedad. El 30 de diciembre del 2004, en la ciudad de Buenos Aires, se produjo un acontecimiento que muchos especialistas consideran un punto de inflexión en la historia de una de las vertientes del rock local: el incendio en el boliche República de Cromañón mientras una banda de rock barrial realizaba un recital. Esa noche se produjo la muerte de ciento noventa y cuatro personas. A raíz de lo sucedido, se abrieron varios debates. Algunos en torno a la pirotecnia utilizada en los recitales de éste tipo de rock y a las prácticas de los jóvenes dentro de éstos espacios; otros en relación a la negligencia del Estado; a la irresponsabilidad del dueño del boliche; a las responsabilidades políticas, entre otros. Sin embargo, nuestro interés no es tallar en esa discusión desde la opinión más o menos experta, sino explorar cómo se relaciona ese acontecimiento con las prácticas y representaciones de determinados agentes sociales que ayudan a producir esa vertiente del rock denominada rock chabón. Con datos recogidos en entrevistas en profundidad dirigidas a un universo pequeño pero variado de actores del campo rock, intentamos explorar los primeros indicios que nos muestran que efectivamente algunos cambios parecen estar produciéndose, aunque como veremos a lo largo de la tesina, esas modificaciones no son elaboradas y categorizadas de la misma manera por los distintos sujetos que investigamos. Es en la variedad de los procesos reflexivos de los actores frente a la conmoción de un acontecimiento como el de "Cromañón", donde intentamos buscar esos indicios, antes que en la opinión fundada o no de especialistas, críticos o artistas consagrados

Propagating excitatory potentials within the fear conditioning circuit of the lateral amygdala

In the Hebbian postulate, transiently reverberating cellular ensembles can sustain activity to facilitate temporal coincidence detection. Auditory fear conditioning is believed to be formed in the lateral amygdala (LA), by way of plasticity at auditory input synapses on principal neurons. To evaluate the contribution of LA cellular ensembles in the formation of conditioned fear memories, we investigated the LA micro-circuitry by electrophysiological and anatomical approaches. Polysynaptic field potentials evoked in the LA by stimulation of auditory thalamus(MGm/PIN) or auditory cortical (TE3) afferents were analyzed in vitro and in vivo. In vivo, two potentials were identified following stimulation of either pathway. In vitro, these multiple potentials were revealed by adding 75uM Picrotoxin or 30uM Bicuculine, with the first potential peaking at 15-20 ms, followed by two additional potentials at 20 – 25 and 30 – 35 ms, respectively. These data show single stimulation events can result in multiple synchronized excitatory events within the lateral amygdala. In order to determine underlying mechanisms of auditory signal propagation, LA principal neuron axon collateral trajectory patterns and morphology were analyzed. Neurons were found to have local axon collaterals that are topographically organized. Each axon collateral within the LA totaled 14.1 ± 2.73mm, had 29.8 ± 9.1 branch points and 1870.8 ± 1035 boutons (n=9). Electrophysiological and anatomical data show that a network of extensive axon collaterals within the LA may facilitate preservation of auditory afferent signals.

Quantification of the total neuronal structure of the fear conditioning circuit of the lateral amygdala of the rat

During Pavlovian auditory fear conditioning a previously neutral auditory stimulus (CS) gains emotional significance through pairing with a noxious unconditioned stimulus (US). These associations are believed to be formed by way of plasticity at auditory input synapses on principal neurons in the lateral nucleus of the amygdala (LA). In order to begin to understand how fear memories are stored and processed by synaptic changes in the LA, we have quantified both the entire neural number and the sub-cellular structure of LA principal neurons.We first used stereological cell counting methods on Gimsa or GABA immunostained rat brain. We identified 60,322+/-1408 neurons in the LA unilaterally (n=7). Of these 16,917+/-471 were GABA positive. The intercalated nuclei were excluded from the counts and thus GABA cells are believed to represent GABAergic interneurons. The sub-nuclei of the LA were also independently counted. We then quantified the morphometric properties of in vitro electrophysiologically identified principal neurons of the LA, corrected for shrinkage in xyz planes. The total dendritic length was 9.97+/-2.57mm, with 21+/-4 nodes (n=6). Dendritic spine density was 0.19+/-0.03 spines/um (n=6). Intra-LA axon collaterals had a bouton density of 0.1+/-0.02 boutons/um (n=5). These data begin to reveal the finite cellular and sub-cellular processing capacity of the lateral amygdala, and should facilitate efforts to understand mechanisms of plasticity in LA.

GABAergic inhibition in the fear conditioning circuit of the lateral amygdala is potentiated by dopamine D1 agonists

Auditory fear conditioning is dependent on auditory signaling from the medial geniculate (MGm) and the auditory cortex (TE3) to principal neurons of the lateral amygdala (LA). Local circuit GABAergic interneurons are known to inhibit LA principal neurons via fast and slow IPSP's. Stimulation of MGm and TE3 produces excitatory post-synaptic potentials in both LA principal and interneurons, followed by inhibitory post-synaptic potentials. Manipulations of D1 receptors in the lateral and basal amygdala modulate the retrieval of learned association between an auditory CS and foot shock. Here we examined the effects of D1 agonists on GABAergic IPSP's evoked by stimulation of MGm and TE3 afferents in vitro. Whole cell patch recordings were made from principal neurons of the LA, at room temperature, in coronal brain slices using standard methods. Stimulating electrodes were placed on the fiber tracts medial to the LA and at the external capsule/layer VI border dorsal to the LA to activate (0.1-0.2mA) MGm and TE3 afferents respectively. Neurons were held at -55.0 mV by positive current injection to measure the amplitude of the fast IPSP. Changes in input resistance and membrane potential were measured in the absence of current injection. Stimulation of MGm or TE3 afferents produced EPSP's in the majority of principal neurons and in some an EPSP/IPSP sequence. Stimulation of MGm afferents produced IPSP's with amplitudes of -2.30 ± 0.53 mV and stimulation of TE3 afferents produced IPSP's with amplitudes of -1.98 ± 1.26 mV. Bath application of 20μM SKF38393 increased IPSP amplitudes to -5.94 ± 1.62 mV (MGm, n=3) and-5.46 ± 0.31 mV (TE3, n=3). Maximal effect occurred <10mins. A small increase in resting membrane potential and decrease in input resistance were observed. These data suggest that DA modulates both the auditory thalamic and auditory cortical inputs to the LA fear conditioning circuit via local GABAergic circuits. Supported by NIMH Grants 00956, 46516, and 58911.

Mathematical modelling of rock-bed solar thermal storage tank

An important application of thermal storage is solar energy for power generation or process heating. Low temperature thermal storage in a packed rock bed is considered best option for thermal storage for solar drying applications. In this paper, mathematical formulations for conical and cylindrical rock bed storage tanks have been developed. The model equations are solved numerically for charging/discharging cycles. From the simulated results, it was observed that for the same aspect ratio between the diameter and the length of the thermal storages, the conical thermal storage had better performance. The temperature distribution was found to be more uniform in the truncated conical shape rock bed storage. Also, the pressure drop over long period of time in the conical thermal storage was lower than that of the cylindrical thermal storage. Hence, the amount of power required from a centrifugal fan was lower.

Applicability of Statistical Learning Algorithms for Spatial Variability of Rock Depth

Two algorithms are outlined, each of which has interesting features for modeling of spatial variability of rock depth. In this paper, reduced level of rock at Bangalore, India, is arrived from the 652 boreholes data in the area covering 220 sqa <.km. Support vector machine (SVM) and relevance vector machine (RVM) have been utilized to predict the reduced level of rock in the subsurface of Bangalore and to study the spatial variability of the rock depth. The support vector machine (SVM) that is firmly based on the theory of statistical learning theory uses regression technique by introducing epsilon-insensitive loss function has been adopted. RVM is a probabilistic model similar to the widespread SVM, but where the training takes place in a Bayesian framework. Prediction results show the ability of learning machine to build accurate models for spatial variability of rock depth with strong predictive capabilities. The paper also highlights the capability ofRVM over the SVM model.

A comparative study of ordinary kriging and support vector machine models for the spatial variability of rock depth in Bangalore

In this paper, reduced level of rock at Bangalore, India is arrived from the 652 boreholes data in the area covering 220 sq.km. In the context of prediction of reduced level of rock in the subsurface of Bangalore and to study the spatial variability of the rock depth, ordinary kriging and Support Vector Machine (SVM) models have been developed. In ordinary kriging, the knowledge of the semivariogram of the reduced level of rock from 652 points in Bangalore is used to predict the reduced level of rock at any point in the subsurface of Bangalore, where field measurements are not available. A cross validation (Q1 and Q2) analysis is also done for the developed ordinary kriging model. The SVM is a novel type of learning machine based on statistical learning theory, uses regression technique by introducing e-insensitive loss function has been used to predict the reduced level of rock from a large set of data. A comparison between ordinary kriging and SVM model demonstrates that the SVM is superior to ordinary kriging in predicting rock depth.

Construction of Equivalent Circuit of a Single and Isolated Transformer Winding From FRA Data Using the ABC Algorithm

This paper reports the results of employing an artificial bee colony search algorithm for synthesizing a mutually coupled lumped-parameter ladder-network representation of a transformer winding, starting from its measured magnitude frequency response. The existing bee colony algorithm is suitably adopted by appropriately defining constraints, inequalities, and bounds to restrict the search space and thereby ensure synthesis of a nearly unique ladder network corresponding to each frequency response. Ensuring near-uniqueness while constructing the reference circuit (i.e., representation of healthy winding) is the objective. Furthermore, the synthesized circuits must exhibit physical realizability. The proposed method is easy to implement, time efficient, and problems associated with the supply of initial guess in existing methods are circumvented. Experimental results are reported on two types of actual, single, and isolated transformer windings (continuous disc and interleaved disc).

Construction of equivalent circuit of a transformer winding from driving-point impedance function - analytical approach

Analytical solution is presented to convert a given driving-point impedance function (in s-domain) into a physically realisable ladder network with inductive coupling between any two sections and losses considered. The number of sections in the ladder network can vary, but its topology is assumed fixed. A study of the coefficients of the numerator and denominator polynomials of the driving-point impedance function of the ladder network, for increasing number of sections, led to the identification of certain coefficients, which exhibit very special properties. Generalised expressions for these specific coefficients have also been derived. Exploiting their properties, it is demonstrated that the synthesis method essentially turns out to be an exercise of solving a set of linear, simultaneous, algebraic equations, whose solution directly yields the ladder network elements. The proposed solution is novel, simple and guarantees a unique network. Presently, the formulation can synthesise a unique ladder network up to six sections.

Construction of Equivalent Circuit of a Single and Isolated Transformer Winding From FRA Data Using the ABC Algorithm

This paper reports the results of employing an artificial bee colony search algorithm for synthesizing a mutually coupled lumped-parameter ladder-network representation of a transformer winding, starting from its measured magnitude frequency response. The existing bee colony algorithm is suitably adopted by appropriately defining constraints, inequalities, and bounds to restrict the search space and thereby ensure synthesis of a nearly unique ladder network corresponding to each frequency response. Ensuring near-uniqueness while constructing the reference circuit (i.e., representation of healthy winding) is the objective. Furthermore, the synthesized circuits must exhibit physical realizability. The proposed method is easy to implement, time efficient, and problems associated with the supply of initial guess in existing methods are circumvented. Experimental results are reported on two types of actual, single, and isolated transformer windings (continuous disc and interleaved disc).

Influence of rock depth on seismic site classification for shallow bedrock regions

Seismic site classifications are used to represent site effects for estimating hazard parameters (response spectral ordinates) at the soil surface. Seismic site classifications have generally been carried out using average shear wave velocity and/or standard penetration test n-values of top 30-m soil layers, according to the recommendations of the National Earthquake Hazards Reduction Program (NEHRP) or the International Building Code (IBC). The site classification system in the NEHRP and the IBC is based on the studies carried out in the United States where soil layers extend up to several hundred meters before reaching any distinct soil-bedrock interface and may not be directly applicable to other regions, especially in regions having shallow geological deposits. This paper investigates the influence of rock depth on site classes based on the recommendations of the NEHRP and the IBC. For this study, soil sites having a wide range of average shear wave velocities (or standard penetration test n-values) have been collected from different parts of Australia, China, and India. Shear wave velocities of rock layers underneath soil layers have also been collected at depths from a few meters to 180 m. It is shown that a site classification system based on the top 30-m soil layers often represents stiffer site classes for soil sites having shallow rock depths (rock depths less than 25 m from the soil surface). A new site classification system based on average soil thickness up to engineering bedrock has been proposed herein, which is considered more representative for soil sites in shallow bedrock regions. It has been observed that response spectral ordinates, amplification factors, and site periods estimated using one-dimensional shear wave analysis considering the depth of engineering bedrock are different from those obtained considering top 30-m soil layers.