Lane reduction in driven 2d-colloidal systems through microchannels

The transport behavior of a system of gravitationally driven colloidal particles is investigated. The particle interactions are determined by the superparamagnetic behavior of the particles. They can thus be arranged in a crystalline order by application of an external magnetic field. Therefore the motion of the particles through a narrow channel occurs in well-defined lanes. The arrangement of the particles is perturbed by diffusion and the motion induced by gravity. Due to these combined influences a density gradient forms along the direction of motion of the particles. A reconfiguration of the crystal is observed leading to a reduction of the number of lanes. In the course of the lane reduction transition a local melting of the quasi-crystalline phase to a disordered phase and a subsequent crystallization along the motion of the particles is observed. This transition is characterized experimentally and using Brownian dynamics (BD) simulations.Comment: 4 pages, 4 figure

Assessment of Austrian contribution toward EU 2020 target sharing: Responding to the energy and climate package of the European Commission

The overarching implications of the EU 2020 targets for Austria call for a fundamental restructuring of the Austrian energy sector towards increased energy efficiency. Two guiding principles for this restructuring are required in order to be compatible with the targets for greenhouse gas emissions and renewables (RES) expected for Austria: final energy consumption needs to be stabilised at the levels of 2005; renewable energy sources need to be expanded at least by 40 percent. For the final negotiations on phase 3 of the EU Emissions Trading System we propose contributions on three issues: 1. operational procedures for dealing with carbon leakage and competitiveness in all sectors that provide criteria for allocating free allowances: 2. empowering the carbon market by extending the task of the emissions allowances issuing carbon authority to control the liquidity of the carbon market in view of stabilising the carbon price; 3. designing the auctioning mechanism by considering timing and auctioning as a strategic instrument for enhancing the carbon market and considering unified auc-tioning with revenues split among EU countries. Similarly we suggest for the final negotiations on the RES Directive improvements that overcome discrepancies between national RES targets and available resources for implementation. This requires in particular improved cooperation between EU countries for a better mapping of targets and potentials

A Neural Map of Interaural Intensity Differences in the Brain Stem of the Barn Owl

The nucleus ventralis lemnisci lateralis pars posterior (VLVp) is the first binaural station in the intensity-processing pathway of the barn owl. Contralateral stimulation excites and ipsilateral stimulation inhibits VLVp cells. The strength of the inhibition declines systematically from dorsal to ventral within the nucleus. Cells selective for different intensity disparities occur in an orderly sequence from dorsal to ventral within each isofrequency lamina. Cells at intermediate depths in the nucleus are selective for a particular narrow range of interaural intensity differences independently of the absolute sound-pressure level. A simple model of the interaction between inhibition and excitation can explain most of the response properties of VLVp neurons. The map of selectivity for intensity disparity is mainly based on the gradient of inhibition

Inner-ear abnormalities and their functional consequences in Belgian Waterslager canaries (Serinus canarius)

Recent reports of elevated auditory thresholds in canaries of the Belgian Waterslager strain have shown that this strain has an inherited auditory deficit in which absolute auditory thresholds at high frequencies (i.e. above 2.0 kHz) are as much as 40 dB less sensitive than the thresholds of mixed-breed canaries and those of other strains. The measurement of CAP audiograms showed that the hearing deficit is already present at the level of the auditory nerve (Gleich and Dooling, 1992). Here we show gross abnormalities in the anatomy of the basilar papilla of Belgian Waterslager canaries at the level of the hair cell. The extent of these abnormalities was correlated with the amount of hearing deficit as measured behaviorally

Frequency decoding of periodically timed action potentials through distinct activity patterns in a random neural network

Frequency discrimination is a fundamental task of the auditory system. The mammalian inner ear, or cochlea, provides a place code in which different frequencies are detected at different spatial locations. However, a temporal code based on spike timing is also available: action potentials evoked in an auditory-nerve fiber by a low-frequency tone occur at a preferred phase of the stimulus-they exhibit phase locking-and thus provide temporal information about the tone's frequency. In an accompanying psychoacoustic study, and in agreement with previous experiments, we show that humans employ this temporal information for discrimination of low frequencies. How might such temporal information be read out in the brain? Here we demonstrate that recurrent random neural networks in which connections between neurons introduce characteristic time delays, and in which neurons require temporally coinciding inputs for spike initiation, can perform sharp frequency discrimination when stimulated with phase-locked inputs. Although the frequency resolution achieved by such networks is limited by the noise in phase locking, the resolution for realistic values reaches the tiny frequency difference of 0.2% that has been measured in humans.Comment: 16 pages, 5 figures, and supplementary informatio

How spiking neurons give rise to a temporal-feature map

A temporal-feature map is a topographic neuronal representation of temporal attributes of phenomena or objects that occur in the outside world. We explain the evolution of such maps by means of a spike-based Hebbian learning rule in conjunction with a presynaptically unspecific contribution in that, if a synapse changes, then all other synapses connected to the same axon change by a small fraction as well. The learning equation is solved for the case of an array of Poisson neurons. We discuss the evolution of a temporal-feature map and the synchronization of the single cells’ synaptic structures, in dependence upon the strength of presynaptic unspecific learning. We also give an upper bound for the magnitude of the presynaptic interaction by estimating its impact on the noise level of synaptic growth. Finally, we compare the results with those obtained from a learning equation for nonlinear neurons and show that synaptic structure formation may profit from the nonlinearity

Frequency-Invariant Representation of Interaural Time Differences in Mammals

Interaural time differences (ITDs) are the major cue for localizing low-frequency sounds. The activity of neuronal populations in the brainstem encodes ITDs with an exquisite temporal acuity of about . The response of single neurons, however, also changes with other stimulus properties like the spectral composition of sound. The influence of stimulus frequency is very different across neurons and thus it is unclear how ITDs are encoded independently of stimulus frequency by populations of neurons. Here we fitted a statistical model to single-cell rate responses of the dorsal nucleus of the lateral lemniscus. The model was used to evaluate the impact of single-cell response characteristics on the frequency-invariant mutual information between rate response and ITD. We found a rough correspondence between the measured cell characteristics and those predicted by computing mutual information. Furthermore, we studied two readout mechanisms, a linear classifier and a two-channel rate difference decoder. The latter turned out to be better suited to decode the population patterns obtained from the fitted model

An unusual case of a microscopic alveolar adenoma coexisting with lung carcinoma: a case report and review of the literature

<p>Abstract</p> <p>Introduction</p> <p>Alveolar adenomas are extremely rare, benign, primary lung tumors of unknown histogenesis that are characterized by proliferative type II alveolar epithelium and septal mesenchyma. Mostly incidental, they are clinically important as they can imitate benign primary and secondary malignant tumors and at times are difficult to differentiate from early-stage lung cancer. We describe the case of a 59-year-old man with an incidental microscopic alveolar adenoma coexisting with poorly differentiated lung carcinoma.</p> <p>Case presentation</p> <p>A 59-year-old Caucasian man with a medical history of smoking and chronic obstructive pulmonary disease was incidentally found to have a right upper lobe mass while undergoing a computed tomographic chest scan as part of a chronic obstructive pulmonary disease clinical trial. Our patient underwent a right upper lobectomy after a bronchoscopic biopsy of the mass revealed the mass to be a carcinoma. A pathological examination revealed an incidental, small, 0.2 cm, well circumscribed lesion on the staple line margin of the lobectomy in addition to the carcinoma. Histopathological and immunohistochemical examinations revealed the lesion to be an alveolar adenoma.</p> <p>Conclusions</p> <p>We report the rare presentation of a microscopic alveolar adenoma coexisting with lung carcinoma. Alveolar adenoma is an entirely benign incidental neoplasm that can be precisely diagnosed using immunohistochemical analysis in addition to its unique histopathological characteristics.</p