1,793 research outputs found

    Slanted matrices, Banach frames, and sampling

    Get PDF
    In this paper we present a rare combination of abstract results on the spectral properties of slanted matrices and some of their very specific applications to frame theory and sampling problems. We show that for a large class of slanted matrices boundedness below of the corresponding operator in p\ell^p for some pp implies boundedness below in p\ell^p for all pp. We use the established resultto enrich our understanding of Banach frames and obtain new results for irregular sampling problems. We also present a version of a non-commutative Wiener's lemma for slanted matrices

    The presence of valine at residue 129 in human prion protein accelerates amyloid formation

    Get PDF
    The polymorphism at residue 129 of the human PRNP gene modulates disease susceptibility and the clinicopathological phenotypes in human transmissible spongiform encephalopathies. The molecular mechanisms by which the effect of this polymorphism are mediated remain unclear. It has been shown that the folding, dynamics and stability of the physiological, alpha-helix-rich form of recombinant PrP are not affected by codon 129 polymorphism. Consistent with this, we have recently shown that the kinetics of amyloid formation do not differ between protein containing methionine at codon 129 and valine at codon 129 when the reaction is initiated from the a-monomeric PrPC-like state. In contrast, we have shown that the misfolding pathway leading to the formation of beta-sheet-rich, soluble oligomer waS favoured by the presence of methionine, compared with valine, at position 129. In the present work, we examine the effect of this polymorphism on the kinetics of an alternative misfolding pathway, that of amyloid formation using partially folded PrP allelomorphs. We show that the valine 129 allelomorph forms amyloids with a considerably shorter lag phase than the methionine 129 allelomorph both under spontaneous conditions and when seeded with pre-formed amyloid fibres. Taken together, our studies demonstrate that the effect of the codon 129 polymorphism depends on the specific misfolding pathway and on the initial conformation of the protein. The inverse propensities of the two allelomorphs to misfold in vitro through the alternative oligomeric and amyloidogenic pathways could explain some aspects of prion diseases linked to this polymorphism such as age at onset and disease incubation time. (c) 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved

    Consumer behavior in the context of global economic transformations

    Get PDF
    Transition to alternative methods of service and omnichannelity allows the buyer to be more demanding and discerning. The current trends in the development of retail trade caused by globalization forcing the redistribution of consumer budget from a high-margin offline cart to a low-margin online cart that instigate not only the necessity of transformations in management, but also the study of consumer behavior. Dynamical development of trading innovative technologies allows the buyers not only to expand the range of their aspiration, but also to become participants in the cognitive and learning processes, where the acquirement of the new experience and emotions influences the traditional ways of making purchases on offline trading. To remain competitive, retailers should not only provide high-quality goods and services at the best prices, but also to contribute to their high-quality and get-to-able supply. Most purchasing decisions are made "by feel", that contradict to the theories of rational choice and theories using marketing concepts. The article gives views on the factors and criteria that determine consumers behavior in online and offline trade.peer-reviewe

    The Experimental WSN Network for Underground Monitoring H2 Abundance in the Mine Atmosphere Karnasurt Mine Lovozero Layered Alkaline Intrusion

    Get PDF
    We have developed specialized equipment based on mini-MDM hydrogen sensors and the WSN telecommunication technology for long-term monitoring of hydrogen content in the environment. Unlike existing methods, the developed equipment makes it possible to carry out measurements directly in the explosion zone with high discreteness in time. This equipment was tested at a large rare-earth deposit of the Lovozero Alkaline Pluton Karnasurt in the underground mining tunnel. We observed a short time very high concentration of hydrogen in the atmosphere (more than 3 orders of normal atmosphere concentration). This discovery is very important because at the time of the explosion one can create abnormally high concentrations of explosive mixtures of hydrocarbon gases that can lead to accidents. The high resolving power of the measurement equipment makes it possible to determine the shape of the anomaly hydrogen of such a concentration and to calculate the volumes of hydrogen released from the rocks, at first time in the practice. The shape of the anomaly usually consists of 2-3 additional peaks of the shape - "dragon-head-like peak". We make an first attempt is made to explain this form of anomaly in the article. The aim of the work in the estimation hydrogen emission in mining ore deposit rare earth elements

    On the Rational Type 0f Moment Angle Complexes

    Full text link
    In this note it is shown that the moment angle complexes Z(K;(D^2,,S^1)) which are rationally elliptic are a product of odd spheres and a diskComment: This version avoids the use of an incorrect result from the literature in the proof of Theorem 1.3. There is some text overlap with arXiv:1410.645

    On the integral cohomology of smooth toric varieties

    Full text link
    Let XΣX_\Sigma be a smooth, not necessarily compact toric variety. We show that a certain complex, defined in terms of the fan Σ\Sigma, computes the integral cohomology of XΣX_\Sigma, including the module structure over the homology of the torus. In some cases we can also give the product. As a corollary we obtain that the cycle map from Chow groups to integral Borel-Moore homology is split injective for smooth toric varieties. Another result is that the differential algebra of singular cochains on the Borel construction of XΣX_\Sigma is formal.Comment: 10 page

    Особенности распределения уровня постоянного потенциала головного мозга у пациентов с хронической ртутной интоксикацией

    Get PDF
    The aim of the research was to reveal features of distribution of DC-potential level of the brain in patients with chronic mercury intoxication.Materials and methods. The study involved 33 male patients with chronic mercury intoxication and 38 healthy men (comparison group) who, by the specifics of their professional activities, were not exposed to neurotropic substances. We used the electrophysiological method of neuroenergy mapping.Results. In the group of patients with chronic mercury intoxication, persons with a low level of constant potential prevailed when compared with the comparison group (36 and 11%, respectively). With a decrease in the level of constant potential in the frontal parts, an increase was observed in the central leads (Fpz – Cz = –1,2 (–6,3–12,6) mV), and with an increase in it, a decrease in the occipital (Fpz-Oz = 4,2 (–4,8–21,4) mV) and the right temporal (Fpz-Td = 0,01 (–6,5–16,3) mV) areas.Right hemisphere temporal asymmetry was manifested in an increase in the Td-Ts index (p = 0,03) when compared with that of the comparison group, (0,66 ± 0,01) and (–4,34 ± 1,12) mV, respectively. Using discriminant analysis, five reliable diagnostic signs were identified: the values of the parameters of the parietal (Pz), right parietal (Pd), right temporal (Td), central (Cz), occipital (Oz) leads. The most informative sign was the value of the index of the parietal lead (Pz, F = 21,1).Conclusion. A distinctive neurophysiological sign associated with chronic exposure to metallic mercury vapors is an increase in indices of the parietal, right parietal, right temporal, central, occipital leads compared with those inherent in the normal population. Цель исследования – выявить особенности распределения уровня постоянного потенциала головного мозга у пациентов с хронической ртутной интоксикацией.Материалы и методы. В исследовании приняли участие 33 пациента мужского пола с хронической ртутной интоксикацией и 38 здоровых мужчин (группа сравнения), которые по специфике профессиональной  деятельности не подвергались воздействию нейротропных веществ. Использовали электрофизиологический метод – нейроэнергокартирование.Результаты. В группе пациентов с хронической ртутной интоксикацией преобладали лица с пониженным уровнем постоянного потенциала при сопоставлении с группой сравнения (36 и 11% соответственно). При снижении уровня постоянного потенциала в лобных отделах наблюдалось повышение показателей в центральных отведениях (Fpz–Cz = –1,2 (–6,3–12,6) мВ), а при его повышении – снижение в затылочной (Fpz-Oz = 4,2 (–4,8–21,4) мВ) и правой височной (Fpz-Td = 0,01 (–6,5–16,3) мВ) областях.Правополушарная височная асимметрия проявилась в увеличении показателя Td-Ts (р = 0,03) при сопоставлении с таковым группы сравнения – (0,66 ± 0,01) и (–4,34 ± 1,12) мВ соответственно. С помощью дискриминантного анализа выявлено пять достоверных диагностических признаков: значения показателей по теменному (Pz), правому теменному (Pd), правому височному (Td), центральному (Cz), затылочному (Oz) отведениям. Наиболее информативным признаком было значение показателя по теменному отведению (Pz, F = 21,1).Заключение. Отличительным нейрофизиологическим признаком, сопряженным с фактом хронического воздействия паров металлической ртути, является повышение показателей по теменному, правому теменному, правому височному, центральному, затылочному отведениям по сравнению с таковыми, присущими нормальной популяции
    corecore