Unsupervised discovery of temporal sequences in high-dimensional datasets, with applications to neuroscience.

Identifying low-dimensional features that describe large-scale neural recordings is a major challenge in neuroscience. Repeated temporal patterns (sequences) are thought to be a salient feature of neural dynamics, but are not succinctly captured by traditional dimensionality reduction techniques. Here, we describe a software toolbox-called seqNMF-with new methods for extracting informative, non-redundant, sequences from high-dimensional neural data, testing the significance of these extracted patterns, and assessing the prevalence of sequential structure in data. We test these methods on simulated data under multiple noise conditions, and on several real neural and behavioral datas. In hippocampal data, seqNMF identifies neural sequences that match those calculated manually by reference to behavioral events. In songbird data, seqNMF discovers neural sequences in untutored birds that lack stereotyped songs. Thus, by identifying temporal structure directly from neural data, seqNMF enables dissection of complex neural circuits without relying on temporal references from stimuli or behavioral outputs

New Cataclysmic Variable 1RXS J073346.0+261933 in Gemini

In course of the search for the optical identifications associated with ROSAT X-ray sources we have found a highly variable object with the very unusual long-term behavior, color indices and high X-ray-to-optical flux ratio. We report the archival photometric light curve from the Catalina Sky Survey, optical spectroscopy from RTT150 and time-resolved photometry from Astrotel-Caucasus telescope. The object appears to be the magnetic cataclysmic variable (polar) with orbital period of P=3.20 hr.Comment: 8 pages, 5 figures. Submitted to Astronomy Letter

Cataclysmic Variables from USNO-B1.0 Catalog: Stars with Outbursts on Infrared Palomar Plates

The search was performed for cataclysmic variable stars with outlying infrared magnitudes in USNO-B1.0 catalog. The selection was limited to objects in the Northern hemisphere with (B1-R1) 3.5. The search method is described, and the details on individual stars are given. In total 27 variable objects were found with 20 being the previously known ones and 7 - new discoveries. 4 of newly found variables are dwarf novae, while the remaining 3 - pulsating red variables of Mira or semi-regular types, including a heavily reddened one in Pelican nebula. The correct pulsation period is determined for two stars discovered by other researchers, and the dwarf nova nature is confirmed for another object previously suspected as such. The perspectives of the proposed search technique in the framework of Virtual Observatory are also discussed.Comment: 8 pages, 10 figures, submitted to Astronomy Letter

International justice as a way to settle conflicts in the world arena : the idea and the implementation

The purpose of this article is to identify the processes regarding the emergence of international justice and the start of international courts functioning. Dialectical, phenomenological and historical methods of analysis is the methodological basis of the article to allow to identify the international justice essence and the specifics of this phenomenon implementation in the initial stages of its development. In the course of this analysis the authors came to the conclusion that the international justice concept formation occurred in the turn of the XIXth and XXth centuries while the international justice formation took place in the first half of the XXth century.peer-reviewe

A role for descending auditory cortical projections in songbird vocal learning

Many learned motor behaviors are acquired by comparing ongoing behavior with an internal representation of correct performance, rather than using an explicit external reward. For example, juvenile songbirds learn to sing by comparing their song with the memory of a tutor song. At present, the brain regions subserving song evaluation are not known. In this study, we report several findings suggesting that song evaluation involves an avian 'cortical' area previously shown to project to the dopaminergic midbrain and other downstream targets. We find that this ventral portion of the intermediate arcopallium (AIV) receives inputs from auditory cortical areas, and that lesions of AIV result in significant deficits in vocal learning. Additionally, AIV neurons exhibit fast responses to disruptive auditory feedback presented during singing, but not during nonsinging periods. Our findings suggest that auditory cortical areas may guide learning by transmitting song evaluation signals to the dopaminergic midbrain and/or other subcortical targets.National Institutes of Health (U.S.) (grant R01 MH067105)McGovern Institute for Brain Research at MIT (Internal funding

Integration of economic shifts in the european development in the second half of the XXth century

Purpose: The article analyzes those processes having initiated the development of the European and political integration. The article is focused on the genesis and the development of the Council for Mutual Economic Assistance, the European Union, NATO and the Warsaw Pact. Design/Methodology/Approach: By applying the system analysis method as well as dialectical and historical methods, the authors have attempted to reveal the significance of those events resulted in modern international organizations establishment. Findings: Authors have analyzed the XX century trends in integration and highlighted Western Europe as the most productive in the process. Authors have provided the USSR and post-USSR integration overview to reveal the European development patterns. Practical Implications: The research results may be implemented into political and educational courses as well as to be used by official authorities. Originality/Value: The main contribution of this study is the deep integration trends'analysis and the emphasis on the unipolar-bipolar-multipolar world's concept.peer-reviewe