Reconstructing Images from Projections Using the Maximum-Entropy Method. Numerical Simulations of Low-Aspect Astrotomography

The reconstruction of images from a small number of projections using the maximum-entropy method (MEM) with the Shannon entropy is considered. MEM provides higher-quality image reconstruction for sources with extended components than the Hogbom CLEAN method, which is also used in low-aspect astrotomography. The quality of image reconstruction for sources with mixed structure containing bright, compact features embedded in a comparatively weak, extended base can be further improved using a difference-mapping method, which requires a generalization of MEM for the reconstruction of sign-variable functions.We draw conclusions based on the results of numerical simulations for a number of model radio sources with various morphologies.Comment: 11 pages, 9 figure

High-visibility multi-photon interference of Hanbury Brown - Twiss type for classical light

Difference-phase (or Hanbury Brown - Twiss type) intensity interference of classical light is considered in higher orders in the intensity. It is shown that, while the visibility of sum-phase (NOON-type) interference for classical sources drops with the order of interference, the visibility of difference-phase interference has opposite behavior. For three-photon and four-photon interference of two coherent sources, the visibility can be as high as 81.8% and 94.4%, respectively. High-visibility three-photon and four-photon interference of space-time and polarization types has been observed in experiment, for both coherent and pseudo-thermal light.Comment: 11 pages, 9 figure

Three-Dimensional Doppler Tomography of the RS Vulpeculae Interacting Binary

Three-dimensional Doppler tomography has been used to study the H$\alpha$ emission sources in the RS Vulpeculae interacting binary. The 2D tomogram of this binary suggested that most of the emission arose from the cool mass losing star with additional evidence of gas flowing close to the predicted trajectory. However, the 3D tomogram revealed surprising evidence of a more pronounced gas stream flow at high $V_z$ velocities from -240 to -360 km s{$^{-1}$}. This behavior is most likely caused by magnetic activity on the cool star since the central velocity plane, defined by $V_z$ = 0 km s{$^{-1}$}, should be coincident with the orbital plane of the binary if the flow is dominated by gravitational forces only. RS Vul has been detected as both an X-ray and a radio source, and it is possible that the RS Vul gas stream may have been deflected by magnetic field lines. This flow is distinctly different from that found in the streamlike state of U CrB, in which the gas flow was confined mostly to the central velocity plane.Comment: 12 pages, 7 figures, submitted to Ap

Soybean Cultivation Cost-effectiveness Depending on Bacterial Preparations and Growth Stimulants Use

Researches and analysis of the data obtained on the basis of the Armavir Experimental Station of the All-Russian Scientific Research Institute of Oilseeds establish the most effective bacterial preparations, growth stimulants and their combination for soybean cultivation under conditions of unstable moisture on ordinary chernozem. The soybeans yield during the seed treatment with the rhizobial preparation Nitrofix P (2 kg/t) in combination with the film former was the highest and amounted to 1.83 t/ha, which is 0.23 t/ha higher than in the control. It also obtained the maximum collection of plant protein – 0,69 t/ha. The highest yields (1.72–1.83 t/ha) and relatively low production costs allow getting quite high profits (19,472–22,191 rub/ha) with complex soybeans seed treatment with rusobial preparations containing a film former. The maximum profitability in the study of seed treatment with rhizobial preparations was obtained in the variants with the use of the preparations Nitrofiks P and Nitrofiks Zh in combination with the film-forming agent – 95–107 %, which is higher in comparison with the use of bacterial preparations by 2–15 %, and with the control by 12–24 %. The most cost-effective (107 %) was the use of rhizobial Nitrofix preparation in its powder form (2 kg/t) combining with a film former. The obtaining soybeans yield – 1.73 t/ha in the treatment of seeds combining with a rhizobial preparation in combination with a growth stimulator Nagro bioenergetic made it possible to get the highest profit – 19 668 rubles/ha. Given the cost of production and profit per hectare rate, the highest level of profitability was obtained when applying seed treatment with the rhizobial preparation Nitrofiks Zh in combination with Albit and Nagro bioenergetic growth stimulants: 91–94 %. Hence it has been established that the bacterial preparations for treating seeds in combination with a film former and growth stimulant use provides high profits and increases the soybean cultivation profitability level

Laplace transformations of hydrodynamic type systems in Riemann invariants: periodic sequences

The conserved densities of hydrodynamic type system in Riemann invariants satisfy a system of linear second order partial differential equations. For linear systems of this type Darboux introduced Laplace transformations, generalising the classical transformations in the scalar case. It is demonstrated that Laplace transformations can be pulled back to the transformations of the corresponding hydrodynamic type systems. We discuss periodic Laplace sequences of with the emphasize on the simplest nontrivial case of period 2. For 3-component systems in Riemann invariants a complete discription of closed quadruples is proposed. They turn to be related to a special quadratic reduction of the (2+1)-dimensional 3-wave system which can be reduced to a triple of pairwize commuting Monge-Ampere equations. In terms of the Lame and rotation coefficients Laplace transformations have a natural interpretation as the symmetries of the Dirac operator, associated with the (2+1)-dimensional n-wave system. The 2-component Laplace transformations can be interpreted also as the symmetries of the (2+1)-dimensional integrable equations of Davey-Stewartson type. Laplace transformations of hydrodynamic type systems originate from a canonical geometric correspondence between systems of conservation laws and line congruences in projective space.Comment: 22 pages, Late

Image quality in double- and triple-intensity ghost imaging with classical partially polarized light

Classical ghost imaging is a correlation-imaging technique in which the image of the object is found through intensity correlations of light. We analyze three different quality parameters, namely the visibility, the signal-to-noise ratio (SNR), and the contrast-to-noise ratio (CNR), to assess the performance of double- and triple-intensity correlation-imaging setups. The source is a random partially polarized beam of light obeying Gaussian statistics and the image quality is evaluated as a function of the degree of polarization (DoP). We show that the visibility improves when the DoP and the order of imaging increase, while the SNR behaves oppositely. The CNR is for the most part independent of DoP and the imaging order. The results are important for the development of new imaging devices using partially polarized light.Comment: Added 2 references, corrected a few typos and revised text slightly. Results unchange

6-ОЙ МЕЖДУНАРОДНЫЙ СИМПОЗИУМ ПО СЪЕДОБНЫМ ЛУКОВЫМ КУЛЬТУРАМ (ЯПОНИЯ, ФУКУОКА, 21-24 МАЯ 2012 ГОДА)

On May 21 - 24, 2012 the 6th International Symposium on Edible Alliaceae was held at Japan (Fukuoka). The symposium was devoted to innovation in agriculture and food science for edible Alliaceae crops. The symposium provided a leading opportunity for scientists, growers and market players from around the world to discuss and share information on genetics and breeding, cultivation, quality control and so on in bulb onion, garlic, and bunching onion.21 по 24 мая 2012 года в г. Фукуока (Япония) проходила международная конференция VIth International Symposium on Edible Alliaceae, проводимая один раз в три года. Главной темой конференции стали последние исследования и инновационные разработки в области биологии, генетики, селекции, сельскохозяйственного производства и переработки съедобных луковых культур

Identification of a small molecule inhibitor that stalls splicing at an early step of spliceosome activation.

Small molecule inhibitors of pre-mRNA splicing are important tools for identifying new spliceosome assembly intermediates, allowing a finer dissection of spliceosome dynamics and function. Here, we identified a small molecule that inhibits human pre-mRNA splicing at an intermediate stage during conversion of pre-catalytic spliceosomal B complexes into activated Bact complexes. Characterization of the stalled complexes (designated B028) revealed that U4/U6 snRNP proteins are released during activation before the U6 Lsm and B-specific proteins, and before recruitment and/or stable incorporation of Prp19/CDC5L complex and other Bact complex proteins. The U2/U6 RNA network in B028 complexes differs from that of the Bact complex, consistent with the idea that the catalytic RNA core forms stepwise during the B to Bact transition and is likely stabilized by the Prp19/CDC5L complex and related proteins. Taken together, our data provide new insights into the RNP rearrangements and extensive exchange of proteins that occurs during spliceosome activation