Push-Pull Control of Motor Output

Inhibition usually decreases input–output excitability of neurons. If, however, inhibition is coupled to excitation in a push–pull fashion, where inhibition decreases as excitation increases, neuron excitability can be increased. Although the presence of push–pull organization has been demonstrated in single cells, its functional impact on neural processing depends on its effect on the system level. We studied push–pull in the motor output stage of the feline spinal cord, a system that allows independent control of inhibitory and excitatory components. Push–pull organization was clearly present in ankle extensor motoneurons, producing increased peak-to-peak modulation of synaptic currents. The effect at the system level was equally strong. Independent control of the inhibitory component showed that the stronger the background of inhibition, the greater the peak force production. This illustrates the paradox at the heart of push–pull organization: increased force output can be achieved by increasing background inhibition to provide greater disinhibition

Financial crisis, economic recovery, and banking development in Russia, Ukraine, and other FSU countries

This paper provides a unified analysis for the onset of the 1998 financial crisis and the strong economic recovery afterward in Russia and other former Soviet Union countries. Before the crisis a banking failure arose owing to the coexistence of a lemons credit market and high government borrowing. In a lemons credit market low credit risk firms switched from bank to nonbank finance, including trade credits and barter trade, generating an externality on banks’ interest rates. The collapse of the treasury bills market in the financial crisis triggered a change in banks’ lending behavior, providing initial conditions for banking development.published_or_final_versio

Low temperature crystal structure and local magnetometry for the geometrically frustrated pyrochlore Tb2Ti2O7

We report synchrotron radiation diffraction and muon spin rotation (muSR) measurements on the frustrated pyrochlore magnet Tb2Ti2O7. The powder diffraction study of a crushed crystal fragment does not reveal any structural change down to 4 K. The muSR measurements performed at 20 mK on a mosaic of single crystals with an external magnetic field applied along a three-fold axis are consistent with published a.c. magnetic-susceptibility measurements at 16 mK. While an inflection point could be present around an internal field intensity slightly above 0.3 T, the data barely support the presence of a magnetization plateau.Comment: To appear in the proceedings of the 13th International Conference on Muon Spin Rotation, Relaxation and Resonance, Grindelwald, Switzerland, 1-6 June 201

Relativistic thermodynamics of perfect fluids

The relativistic continuity equations for the extensive thermodynamic quantities are derived based on the divergence theorem in Minkowski space outlined by St\"uckelberg. This covariant approach leads to a relativistic formulation of the first and second laws of thermodynamics. The internal energy density and the pressure of a relativistic perfect fluid carry inertia, which leads to a relativistic coupling between heat and work. The relativistic continuity equation for the relativistic inertia is derived. The relativistic corrections in the Euler equation and in the continuity equations for the energy and momentum are identified. This relativistic theoretical framework allows a rigorous derivation of the relativistic transformation laws for the temperature, the pressure and the chemical potential based on the relativistic transformation laws for the energy density, the entropy density, the mass density and the number density.Comment: 62 page

Performant DLC Films with Enhanced Wear Resistance

Diamond-like Carbon (DLC) coatings represent an interesting research subject for various groups of researchers having interests in surfaces tribology and corrosion. This paper discusses issues relating to the friction and mechanical behaviour, for 4 types of DLC coating systems deposited on heat treatable steel hardened and high-tempered (a multilayer of WC/C (a-C:H:W); CrC+a-C:H, a single layer of a-C:H, plasma nitriding + Si doped DLC (PN+Si-a-C:H). These films were synthesized using a single or a combined process consisting in either r. f. reactive magnetron sputtering or/followed by Plasma Assisted Chemical Vapour Deposition (PACVD). The tribological properties (friction coefficient) were obtained and discussed in correlation with the mechanical properties (the adherence, the nanoindentation hardness) and thickness When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3491

Optically Thin Metallic Films for High-radiative-efficiency Plasmonics

Plasmonics enables deep-subwavelength concentration of light and has become important for fundamental studies as well as real-life applications. Two major existing platforms of plasmonics are metallic nanoparticles and metallic films. Metallic nanoparticles allow efficient coupling to far field radiation, yet their synthesis typically leads to poor material quality. Metallic films offer substantially higher quality materials, but their coupling to radiation is typically jeopardized due to the large momentum mismatch with free space. Here, we propose and theoretically investigate optically thin metallic films as an ideal platform for high-radiative-efficiency plasmonics. For far-field scattering, adding a thin high-quality metallic substrate enables a higher quality factor while maintaining the localization and tunability that the nanoparticle provides. For near-field spontaneous emission, a thin metallic substrate, of high quality or not, greatly improves the field overlap between the emitter environment and propagating surface plasmons, enabling high-Purcell (total enhancement > $10^4$), high-quantum-yield (> 50 %) spontaneous emission, even as the gap size vanishes (3$\sim$5 nm). The enhancement has almost spatially independent efficiency and does not suffer from quenching effects that commonly exist in previous structures.Comment: Supporting Information not included but freely available from DOI:10.1021/acs.nanolett.6b0085

Zoneamento agrícola de riscos climáticos da laranja no Estado de São Paulo.

O presente estudo teve como objetivo realizar um zoneamento climático observando os riscos para o estado de São Paulo no que se refere ao cultivo de laranja. Os resultados foram obtidos através da análise do déficit hídrico médio anual, temperaturas médias anuais e precipitações médias anuais. Essas variáveis foram extraídas do banco de dados da Embrapa Informática Agropecuária. Entretanto, os dados do déficit hídrico foram calculados pelo método de THORNTHWAITE e MATHER (1955), corrigido por CAMARGO et al. (1999). As localidades foram classificadas de acordo com as exigências climáticas de cada cultura, dentro de um ambiente de Sistema de Informação Geográfica (SIG), que produziu mapas de riscos climáticos através de espacialização e interpolação. O zoneamento de riscos mostrou que as regiões do noroeste e litoral do estado de São Paulo possuem alto risco climático para a produção de laranja. Os resultados podem auxiliar em novos estudos desta cultura importante do agronegócio brasileiro.CBA 2009

Zoneamento de riscos climáticos para a dendeicultura no Brasil.

Neste presente trabalho obtiveram-se os resultados do zoneamento de riscos climáticos da cultura do dendê no Brasil. Utilizando os parâmetros climáticos como a temperatura média anual, precipitação média anual e déficit hídrico, puderam-se analisar e espacializar os dados através de um Sistema de Informações Geográficas. Além disso, foi utilizada a máscara do Shutlle Radar Topography Mission (SRTM) para ajustes no relevo. Segundo o método de THORNTHWAITE e MATHER (1955), corrigido por CAMARGO et al. (1999), foram calculados os dados de déficit hídrico. Desta forma, o trabalho teve como principais resultados obtidos, o mapa com a malha municipal de aptidão climática discretizado por classes de riscos. Através desses resultados, observou-se baixo risco climático para estados já produtores como a Bahia, Pará e Amazonas, além de potenciais áreas produtoras como o litoral do nordeste e parte do Rio de Janeiro. Os resultados podem auxiliar no suporte a expansão dessa oleaginosa em território nacional, visto a importância dessa cultura como fonte de biodiesel.CBA 2009