Neuronal assembly dynamics in supervised and unsupervised learning scenarios

The dynamic formation of groups of neurons—neuronal assemblies—is believed to mediate cognitive phenomena at many levels, but their detailed operation and mechanisms of interaction are still to be uncovered. One hypothesis suggests that synchronized oscillations underpin their formation and functioning, with a focus on the temporal structure of neuronal signals. In this context, we investigate neuronal assembly dynamics in two complementary scenarios: the first, a supervised spike pattern classification task, in which noisy variations of a collection of spikes have to be correctly labeled; the second, an unsupervised, minimally cognitive evolutionary robotics tasks, in which an evolved agent has to cope with multiple, possibly conflicting, objectives. In both cases, the more traditional dynamical analysis of the system’s variables is paired with information-theoretic techniques in order to get a broader picture of the ongoing interactions with and within the network. The neural network model is inspired by the Kuramoto model of coupled phase oscillators and allows one to fine-tune the network synchronization dynamics and assembly configuration. The experiments explore the computational power, redundancy, and generalization capability of neuronal circuits, demonstrating that performance depends nonlinearly on the number of assemblies and neurons in the network and showing that the framework can be exploited to generate minimally cognitive behaviors, with dynamic assembly formation accounting for varying degrees of stimuli modulation of the sensorimotor interactions

Wigner phase space distribution as a wave function

We demonstrate that the Wigner function of a pure quantum state is a wave function in a specially tuned Dirac bra-ket formalism and argue that the Wigner function is in fact a probability amplitude for the quantum particle to be at a certain point of the classical phase space. Additionally, we establish that in the classical limit, the Wigner function transforms into a classical Koopman-von Neumann wave function rather than into a classical probability distribution. Since probability amplitude need not be positive, our findings provide an alternative outlook on the Wigner function's negativity.Comment: 6 pages and 2 figure

Моделі процесів захисту цілісності інформаційних об’єктів з використанням коду умовних лишків. Алгоритм нулізації

The models of processes of defense of integrity of information’s holding object with application of code of conditional tailings which provide high probabilities of exposure of violations of integrity and correction of the exposed curvatures are examined

The 'Parekh Report' - national identities with nations and nationalism

‘Multiculturalists’ often advocate national identities. Yet few study the ways in which ‘multiculturalists’ do so and in this article I will help to fill this gap. I will show that the Commission for Multi-Ethnic Britain’s report reflects a previously unnoticed way of thinking about the nature and worth of national identities that the Commission’s chair, and prominent political theorist, Bhikhu Parekh, had been developing since the 1970s. This way of thinking will be shown to avoid the questionable ways in which conservative and liberal nationalists discuss the nature and worth of national identities while offering an alternative way to do so. I will thus show that a report that was once criticised for the way it discussed national identities reflects how ‘multiculturalists’ think about national identities in a distinct and valuable way that has gone unrecognised

‘Isles of Wonder’: performing the mythopoeia of utopic multi-ethnic Britain

Within this article, I interrogate the mediated ‘narratives of nation’ told through the London 2012 Olympic Opening Ceremony. Such narratives are not just pedagogic, they are political and ideological processes that require us to pose questions about the place of the past in the present and with regard to who is entitled to speak that past. I suggest that the ceremony performed an ‘aesthetic of selective silence’ and offered a platform to induce nostalgia and identification beyond our own selves while offering a powerful historical teleology: multi-ethnic Britain was given no past, rather, the ‘noises’ that were amplified in the present provided a common, fixed and concretely grounded past that centred on an Anglicized, simple, stable, safe and pure fantasy in which divisions – gendered, classed, raced – were mere historical artifacts. I argue that the ceremony provided for the delivery of a multi-ethnic national fantasy that highlights central issues of being, belonging, privilege and hierarchy within a postcolonial heterophilic Britain, and which reasserts a utopic abstraction of nation and assimilation to core British values

Why Bothering to Measure Stellar Rotation with CoRoT?

One important goal of the CoRoT experiment is to obtain information about the internal rotation of stars, in particular the ratio of central to surface rotation rates. This will provide constraints on the modelling of transport mechanisms of angular momentum acting in radiative (rotationally induced turbulent) and convective zones (plumes, extension beyond convectively instable regions). Relations between the surface rotation period and age, magnetic activity, mass loss and other stellar characteristics can also be studied with a statistically significant set of data as will be provided by Corot. We present various theoretical efforts performed over the past years in order to develope the theoretical tools which will enable us to study rotation with Corot

J-PLUS : a catalogue of globular cluster candidates around the M 81/M 82/NGC 3077 triplet of galaxies

Globular clusters (GCs) are proxies of the formation assemblies of their host galaxies. However, few studies exist targeting GC systems of spiral galaxies up to several effective radii. Through 12-band Javalambre Photometric Local Universe Survey (J-PLUS) imaging, we study the point sources around the M 81/M 82/NGC 3077 triplet in search of new GC candidates. We develop a tailored classification scheme to search for GC candidates based on their similarity to known GCs via a principal component analysis projection. Our method accounts for missing data and photometric errors. We report 642 new GC candidates in a region of 3.5 deg2 around the triplet, ranked according to their Gaia astrometric proper motions when available. We find tantalizing evidence for an overdensity of GC candidate sources forming a bridge connecting M 81 and M 82. Finally, the spatial distribution of the GC candidates (g − i) colours is consistent with halo/intra-cluster GCs, i.e. it gets bluer as they get further from the closest galaxy in the field. We further employ a regression-tree-based model to estimate the metallicity distribution of the GC candidates based on their J-PLUS bands. The metallicity distribution of the sample candidates is broad and displays a bump towards the metal-rich end. Our list increases the population of GC candidates around the triplet by threefold, stresses the usefulness of multiband surveys in finding these objects, and provides a testbed for further studies analysing their spatial distribution around nearby (spirals) galaxies

Genome-wide association study of patient and clinician rated global impression severity during antipsychotic treatment

Examine the unique and congruent findings between multiple raters in a genome-wide association studies (GWAS) in the context of understanding individual differences in treatment response during antipsychotic therapy for schizophrenia

Genotype-Based Ancestral Background Consistently Predicts Efficacy and Side Effects across Treatments in CATIE and STAR*D

Only a subset of patients will typically respond to any given prescribed drug. The time it takes clinicians to declare a treatment ineffective leaves the patient in an impaired state and at unnecessary risk for adverse drug effects. Thus, diagnostic tests robustly predicting the most effective and safe medication for each patient prior to starting pharmacotherapy would have tremendous clinical value. In this article, we evaluated the use of genetic markers to estimate ancestry as a predictive component of such diagnostic tests. We first estimated each patient’s unique mosaic of ancestral backgrounds using genome-wide SNP data collected in the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) (n = 765) and the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) (n = 1892). Next, we performed multiple regression analyses to estimate the predictive power of these ancestral dimensions. For 136/89 treatment-outcome combinations tested in CATIE/STAR*D, results indicated 1.67/1.84 times higher median test statistics than expected under the null hypothesis assuming no predictive power (p<0.01, both samples). Thus, ancestry showed robust and pervasive correlations with drug efficacy and side effects in both CATIE and STAR*D. Comparison of the marginal predictive power of MDS ancestral dimensions and self-reported race indicated significant improvements to model fit with the inclusion of MDS dimensions, but mixed evidence for self-reported race. Knowledge of each patient’s unique mosaic of ancestral backgrounds provides a potent immediate starting point for developing algorithms identifying the most effective and safe medication for a wide variety of drug-treatment response combinations. As relatively few new psychiatric drugs are currently under development, such personalized medicine offers a promising approach toward optimizing pharmacotherapy for psychiatric conditions