Enhanced stability of bound pairs at nonzero lattice momenta

A two-body problem on the square lattice is analyzed. The interaction potential consists of strong on-site repulsion and nearest-neighbor attraction. Exact pairing conditions are derived for s-, p-, and d-symmetric bound states. The pairing conditions are strong functions of the total pair momentum K. It is found that the stability of pairs increases with K. At weak attraction, the pairs do not form at the $\Gamma$-point but stabilize at lattice momenta close to the Brillouin zone boundary. The phase boundaries in the momentum space, which separate stable and unstable pairs are calculated. It is found that the pairs are formed easier along the $(\pi,0)$ direction than along the $(\pi,\pi)$ direction. This might lead to the appearance of ``hot pairing spots" on the Kx and Ky axes.Comment: 7 RevTEX pages, 5 figure

Environmental pollution impact on radiation properties of atmosphere, snow and ice cover: Study from Barentsburg (Spitsbergen Archipelago)

The value of the albedo of snow and ice surface is associated with the texture and structure of the surface layer of snow or ice (sea ice, glaciers), the peculiarities of the vertical redistribution of contaminations in this layer (mineral or organic particles of various concentrations, the size and shape), temperature regime of the surface layer of the atmosphere. Identifying links with the albedo characteristics of natural and artificial contamination is very important. For example, the results of mathematic modeling the evolution of ice sheets, sea ice and snow cover demonstrate the high sensitivity of the model to this parameter. Original results in the framework of this problem were obtained by researches from AARI and St. Petersburg State University during the 2010-2012 years on Svalbard in the vicinity of the Russian mining settlement Barentsburg. We present original results showing the relationship of "albedo-contaminations" and the influence of anthropogenic factors. The estimation of solar radiation that penetrates deep into the snow, and the impact of contamination on its redistribution in the snow thickness were obtained

The Chinese Diaspora in the EU Countries

This article is a further contribution to the discourse of ethnic ‘diffusion’ in European countries. The debate started on the pages of the Baltic Region journal by three authors - Yu. N. Gladky, I. Yu. Gladky, and K. Yu. Eidemiller [4]. We assume that Europe has been a major centre of attraction for immigrants in recent decades and a site for the rapid emergence of ethnic communities. Unlike Muslim immigration, a product of the Arab Spring and often a measure of last resort, Chinese immigration is a result of a certain convergence between the ideologies of the host countries, committed to multiculturalism, and the country of origin pursuing a 'go global' policy. We chose the EU countries as a 'demonstration site' and the Chinese diaspora as the object of research. Our aim is to describe the process of migration from China and the formation of a Chinese diaspora in European countries. We analyse the timeline and the scope of Chinese immigration, qualitative changes in the composition of immigrants, factors affecting the choice of the country of entry, and the quantitative parameters and settlement patterns of today's Chinese diaspora in the region. We suggest grouping the EU Countries by the number and 'age' of their Chinese diasporas. We consider ethnic 'diffusion' as part of the ‘European project' within Beijing’s global strategy

Primary Sequences of Protein-Like Copolymers: Levy Flight Type Long Range Correlations

We consider the statistical properties of primary sequences of two-letter HP copolymers (H for hydrophobic and P for polar) designed to have water soluble globular conformations with H monomers shielded from water inside the shell of P monomers. We show, both by computer simulations and by exact analytical calculation, that for large globules and flexible polymers such sequences exhibit long-range correlations which can be described by Levy-flight statistics.Comment: 4 pages, including 2 figures; several references added, some formulations improve

К вопросу о контроле и автоматизации шахтных дегазационных систем

Розглянуті існуючі системи контролю та автоматизації шахтної газопровідної мережі, а також засобі контролю газодинамічних параметрів метано-повітряної суміші у дільничному дегазаційному трубопроводі.The existing system of control and automation of mine degassingnetwork, and controls the gasdynamic parameters of methane-air mixture in the precinct line degassing

A new model of a tidally disrupted star

A new semi-analytical model of a star evolving in a tidal field is proposed. The model is a generalization of the so-called 'affine' stellar model. In our model the star is composed of elliptical shells with different parameters and different orientations, depending on time and on the radial Lagrangian coordinate of the shell. The evolution equations of this model are derived from the virial relations under certain assumptions, and the integrals of motion are identified. It is shown that the evolution equations can be deduced from a variational principle. The evolution equations are solved numerically and compared quantitatively with the results of 3D numerical computations of the tidal interaction of a star with a supermassive black hole. The comparison shows very good agreement between the main ``integral'' characteristics describing the tidal interaction event in our model and in the 3D computations. Our model is effectively a one-dimensional Lagrangian model from the point of view of numerical computations, and therefore it can be evolved numerically $10^{2}-10^{3}$ times faster than the 3D approach allows. This makes our model well suited for intensive calculations covering the whole parameter space of the problem.Comment: This version is accepted for publication in ApJ. Stylistic and grammatical changes, new Appendix adde

Systematic analysis of the PTEN 5 ' leader identifies a major AUU initiated proteoform

Abundant evidence for translation within the 5' leaders of many human genes is rapidly emerging, especially, because of the advent of ribosome profiling. In most cases, it is believed that the act of translation rather than the encoded peptide is important. However, the wealth of available sequencing data in recent years allows phylogenetic detection of sequences within 5' leaders that have emerged under coding constraint and therefore allow for the prediction of functional 5' leader translation. Using this approach, we previously predicted a CUG-initiated, 173 amino acid N-terminal extension to the human tumour suppressor PTEN. Here, a systematic experimental analysis of translation events in the PTEN 5' leader identifies at least two additional non-AUG-initiated PTEN proteoforms that are expressed in most human cell lines tested. The most abundant extended PTEN proteoform initiates at a conserved AUU codon and extends the canonical AUG-initiated PTEN by 146 amino acids. All N-terminally extended PTEN proteoforms tested retain the ability to downregulate the PI3K pathway. We also provide evidence for the translation of two conserved AUG-initiated upstream open reading frames within the PTEN 5' leader that control the ratio of PTEN proteoforms

Interaction of tau with the RNA-Binding Protein TIA1 Regulates tau Pathophysiology and Toxicity

Dendritic mislocalization of microtubule associated protein tau is a hallmark of tauopathies, but the role of dendritic tau is unknown. We now report that tau interacts with the RNA-binding protein (RBP) TIA1 in brain tissue, and we present the brain-protein interactome network for TIA1. Analysis of the TIA1 interactome in brain tissue from wild-type (WT) and tau knockout mice demonstrates that tau is required for normal interactions of TIA1 with proteins linked to RNA metabolism, including ribosomal proteins and RBPs. Expression studies show that tau regulates the distribution of TIA1, and tau accelerates stress granule (SG) formation. Conversely, TIA1 knockdown or knockout inhibits tau misfolding and associated toxicity in cultured hippocampal neurons, while overexpressing TIA1 induces tau misfolding and stimulates neurodegeneration. Pharmacological interventions that prevent SG formation also inhibit tau pathophysiology. These studies suggest that the pathophysiology of tauopathy requires an intimate interaction with RNA-binding proteins