Approximations by graphs and emergence of global structures

We study approximations of billiard systems by lattice graphs. It is demonstrated that under natural assumptions the graph wavefunctions approximate solutions of the Schroedinger equation with energy rescaled by the billiard dimension. As an example, we analyze a Sinai billiard with attached leads. The results illustrate emergence of global structures in large quantum graphs and offer interesting comparisons with patterns observed in complex networks of a different nature.Comment: 6 pages, RevTeX with 5 ps figure

Penetration of PLGA nanoparticles into the intracranial rat C6 Glioma: Influence of surfactant coating

As shown by our previous studies, the PLGA nanoparticles (NP) coated with poloxamer 188 (P188) enable brain delivery of doxorubicin and its high anti-tumour effect against the intracranial glioblastoma in rats [1]. The objective of the present study was to evaluate the uptake of the P188-coated PLGA NP in the intracranial C6 glioma in rats. For visualization using scanning laser confocal microscopy (SLCM) and an intravital fluorescence imaging system IvisÒSpectrum CT (Perkin-Elmer), the NP were labeled with DiI (DiI-PLGA NP). The DiI-PLGA NP were administered i.v. into rats with intracranial C6 glioma on day 15 after tumour implantation. The presence of mass lesion was verified by previous MRI. Two hours after administration of the NP, the rats were perfused transcardially with paraformaldehyde, organs were recovered, and the fluorescence intensity was assessed using an IvisÒSpectrum CT system. The fluorescence intensity of the hemisphere with the implanted glioma was \u3e 4-fold higher for the P188-coated NP (DiI-PLGA/P188 NP), as compared to the uncoated NP (45.1×106 vs 9.5×106 photons/sec/cm2, respectively (Figure). The quantitative fluorescence analysis on the tumor sections using SLCM also showed a significantly higher accumulation of the DiI-PLGA/P188 NP, as compared to the uncoated DiI-PLGA NP (Fig. 2). Mean fluorescence intensity values in the tumor were 1698.9±536.6 and 558.9±181.0 CU for the P188-coated and uncoated NP, respectively. The intensity values in the contralateral hemispheres for the same preparations were 293.4 ± 32.3 and 203.2 ± 22.9 CU, respectively. Thus, according to the SLCM data, the penetration of the DiI-PLGA/P188 NP into the tumor was 3 times more effective than that of the uncoated NP. Please click Additional Files below to see the full abstract

The influence of heat treatment on homogeneity of strength properties and structural peculiarities of low-carbon steel Fe-Mo-Nb-V-C processed by high-pressure torsion

A homogeneity of strength properties (microhardness) through the specimens and the peculiarities of an ultrafine-grained structure produced in low-carbon steel Fe-Mo-Nb-V-C by cold high-pressure torsion, depending on initial heat treatment of steel were studied. As a result of high-pressure torsion, the microhardness of steel was increased up to 700-770 HV (in the middle part of disk radii), and the mean (sub)grain size was reduced to ?100 nm. Initial quenching of low-carbon steel provides a more homogeneous distribution of microhardness through the disk and the higher strength properties after high-pressure torsion in comparison with a normalizing initial state

The influence of heat treatment on homogeneity of strength properties and structural peculiarities of low-carbon steel Fe-Mo-Nb-V-C processed by high-pressure torsion

A homogeneity of strength properties (microhardness) through the specimens and the peculiarities of an ultrafine-grained structure produced in low-carbon steel Fe-Mo-Nb-V-C by cold high-pressure torsion, depending on initial heat treatment of steel were studied. As a result of high-pressure torsion, the microhardness of steel was increased up to 700-770 HV (in the middle part of disk radii), and the mean (sub)grain size was reduced to ?100 nm. Initial quenching of low-carbon steel provides a more homogeneous distribution of microhardness through the disk and the higher strength properties after high-pressure torsion in comparison with a normalizing initial state

Increasing the efficiency of atmospheric air control in urban areas with developed engineering and chemical clusters

The article gives an example of organizing independent monitoring of atmospheric air using a mobile environmental laboratory. An approach to the formation of the technical characteristics of a mobile laboratory, as well as a methodology for determining the conditions for the departure of the laboratory, is described. The main results of the mobile laboratory are shown, the exceedances of maximum permissible concentrations found and recommendations developed to ensure a radical reduction in the level of atmospheric air pollution on the example of the urban district of Tolyatti are shown

Pan-Eurasian Experiment (PEEX) Program : An Overview of the First 5 Years in Operation and Future Prospects

The Pan-Eurasian Experiment (PEEX) program was initiated as a bottom-up approach by the researchers coming from Finland and Russia in October 2012. The PEEX China kick off meeting was held in November 2013. During its five years in operation, the program has established a governance structure and delivered a science plan for the Northern Eurasian region. PEEX has also introduced a concept design for a modelling platform and ground-based in situ observation systems for detecting land-atmosphere and ocean-atmosphere interactions. Today, PEEX has an extensive researcher’s network representing research communities coming from the Nordic countries, Russia and China. PEEX is currently carrying out its research activities on a project basis, but is looking for more coordinated funding bases, especially in Russia and in China. The near-future challenge in implementing the PEEX research agenda is to achieve a successful integration and identification of the methodological approaches of the socio-economic research to environmental sciences. Here we give insight into these issues and provide an overview on the main tasks for the upcoming years.The Pan-Eurasian Experiment (PEEX) program was initiated as a bottom-up approach by the researchers coming from Finland and Russia in October 2012. The PEEX China kick off meeting was held in November 2013. During its five years in operation, the program has established a governance structure and delivered a science plan for the Northern Eurasian region. PEEX has also introduced a concept design for a modelling platform and ground-based in situ observation systems for detecting land-atmosphere and ocean-atmosphere interactions. Today, PEEX has an extensive researcher’s network representing research communities coming from the Nordic countries, Russia and China. PEEX is currently carrying out its research activities on a project basis, but is looking for more coordinated funding bases, especially in Russia and in China. The near-future challenge in implementing the PEEX research agenda is to achieve a successful integration and identification of the methodological approaches of the socio-economic research to environmental sciences. Here we give insight into these issues and provide an overview on the main tasks for the upcoming years.The Pan-Eurasian Experiment (PEEX) program was initiated as a bottom-up approach by the researchers coming from Finland and Russia in October 2012. The PEEX China kick off meeting was held in November 2013. During its five years in operation, the program has established a governance structure and delivered a science plan for the Northern Eurasian region. PEEX has also introduced a concept design for a modelling platform and ground-based in situ observation systems for detecting land-atmosphere and ocean-atmosphere interactions. Today, PEEX has an extensive researcher’s network representing research communities coming from the Nordic countries, Russia and China. PEEX is currently carrying out its research activities on a project basis, but is looking for more coordinated funding bases, especially in Russia and in China. The near-future challenge in implementing the PEEX research agenda is to achieve a successful integration and identification of the methodological approaches of the socio-economic research to environmental sciences. Here we give insight into these issues and provide an overview on the main tasks for the upcoming years.Peer reviewe

Assemblathon 2: evaluating de novo methods of genome assembly in three vertebrate species

Background: The process of generating raw genome sequence data continues to become cheaper, faster, and more accurate. However, assembly of such data into high-quality, finished genome sequences remains challenging. Many genome assembly tools are available, but they differ greatly in terms of their performance (speed, scalability, hardware requirements, acceptance of newer read technologies) and in their final output (composition of assembled sequence). More importantly, it remains largely unclear how to best assess the quality of assembled genome sequences. The Assemblathon competitions are intended to assess current state-of-the-art methods in genome assembly. Results: In Assemblathon 2, we provided a variety of sequence data to be assembled for three vertebrate species (a bird, a fish, and snake). This resulted in a total of 43 submitted assemblies from 21 participating teams. We evaluated these assemblies using a combination of optical map data, Fosmid sequences, and several statistical methods. From over 100 different metrics, we chose ten key measures by which to assess the overall quality of the assemblies. Conclusions: Many current genome assemblers produced useful assemblies, containing a significant representation of their genes and overall genome structure. However, the high degree of variability between the entries suggests that there is still much room for improvement in the field of genome assembly and that approaches which work well in assembling the genome of one species may not necessarily work well for another