357 research outputs found

    SOIL ORGANIC MATTER STATUS IN AGRICULTURAL SOIL SEQUENCE OF FORMER SHORELINE OF DISAPPEARING SUMOWSKIE LAKES, NORTH-EASTERN POLAND

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    The aim of the study has been to define the stocks and the basic properties of soil organic matter in agricultural-used soil sequence located in the former shoreline of disappearing lakes. The study area is located in the catchment of the Sumowskie Lakes, the Brodnica Lake District, North-Eastern Poland. The investigations involved preparation of five soil pits located in the south-western part of the former Sumowskie Lake bottom and on the southern slope of the adjacent kame hill. The greatest soil transformation is reflected in the quality and quantity of the soil organic matter. Indexes of organic matter quality and TOC stocks are significantly changing along the studied transect. The strongly humidified organic matter is found in mursh horizons. Gyttja layers above the groundwater level have a medium humification index. Horizons saturated with water are very low humidified. TOC stocks drop along the analysed soil sequence from the biogenic plain to the top of the kame hill. Celem badań było określenie zasobów i podstawowych właściwości materii organicznej sekwencji rolniczo użytkowanych gleb dawnej strefy brzegowej zanikających jezior. Obszar badań był zlokalizowany w zlewni jezior Sumowskich na Pojezierzu Brodnickim w Polsce północno-wschodniej. Analizowano transekt składający się z pięciu profili glebowych znajdujących się w pd.-zach. części dawnego Jeziora Sumowskiego. Obejmował on dno dawnego jeziora oraz przylegające wzgórze kemowe. Największe zróżnicowanie gleb dotyczyło ilości i jakości glebowej materii organicznej. Zarówno właściwości materii organicznej, jak i jej zasoby wyraźnie różnicują się w analizowanym transekcie. Materia organiczna poziomów murszowych gleb pojeziornych odznacza się najwyższym stopniem humifikacji, warstwy gytii, powyżej poziomu wód gruntowych, pośrednim, a poziomy nasycone wodą najniższym spośród analizowanych. Zasoby węgla organicznego zmniejszają się wzdłuż transektu od gleb pojeziornych do szczytu pagórka kemowego (pararędziny)

    A proof of uniqueness of the Gurarii space

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    We present a short and elementary proof of isometric uniqueness of the Gurarii space.Comment: 6 pages, some improvements incorporate

    Measurement-Adaptive Cellular Random Access Protocols

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    This work considers a single-cell random access channel (RACH) in cellular wireless networks. Communications over RACH take place when users try to connect to a base station during a handover or when establishing a new connection. Within the framework of Self-Organizing Networks (SONs), the system should self- adapt to dynamically changing environments (channel fading, mobility, etc.) without human intervention. For the performance improvement of the RACH procedure, we aim here at maximizing throughput or alternatively minimizing the user dropping rate. In the context of SON, we propose protocols which exploit information from measurements and user reports in order to estimate current values of the system unknowns and broadcast global action-related values to all users. The protocols suggest an optimal pair of user actions (transmission power and back-off probability) found by minimizing the drift of a certain function. Numerical results illustrate considerable benefits of the dropping rate, at a very low or even zero cost in power expenditure and delay, as well as the fast adaptability of the protocols to environment changes. Although the proposed protocol is designed to minimize primarily the amount of discarded users per cell, our framework allows for other variations (power or delay minimization) as well.Comment: 31 pages, 13 figures, 3 tables. Springer Wireless Networks 201

    SEX-SPECIFIC DIFFERENCES IN COGNITIVE FUNCTIONING AMONG SCHIZOPHRENIC PATIENTS

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    Background: Cognitive deficits in schizophrenia are regarded by many psychiatrist as an important symptom, which requires appropriate treatment and rehabilitation. There are different conditions, which may have an influence on cognitive impairment in schizophrenic patients. One the factors differentiating subgroups of schizophrenic patients when neuropsychological functioning is analyzed is sex. Subjects and methods: This Review was focused on cognitive functioning of schizophrenic patients of different sexes. In order to achieve this result PubMed was searched using following terms: cognitive functions, schizophrenia, gender differences, sex hormones, memory, attention, neuropsychological, psychopatological symptoms. Results: Most of the analyzed papers reflecting the cognitive differences between men and women suffering from schizophrenia postulate a worse performance in neuropsychological test by male patients. However according to some authors there are no gender differences in cognitive functioning in schizophrenic patients or those differences are not clinically significant. Conclusions: The problem of sex-specific differences in cognitive functioning in patients in schizophrenia needs further investigation

    Non-liftable Calabi-Yau spaces

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    We construct many new non-liftable three-dimensional Calabi-Yau spaces in positive characteristic. The technique relies on lifting a nodal model to a smooth rigid Calabi-Yau space over some number field as introduced by the first author and D. van Straten.Comment: 16 pages, 5 tables; v2: minor corrections and addition

    SEX-SPECIFIC DIFFERENCES IN COGNITIVE FUNCTIONING AMONG SCHIZOPHRENIC PATIENTS

    Get PDF
    Background: Cognitive deficits in schizophrenia are regarded by many psychiatrist as an important symptom, which requires appropriate treatment and rehabilitation. There are different conditions, which may have an influence on cognitive impairment in schizophrenic patients. One the factors differentiating subgroups of schizophrenic patients when neuropsychological functioning is analyzed is sex. Subjects and methods: This Review was focused on cognitive functioning of schizophrenic patients of different sexes. In order to achieve this result PubMed was searched using following terms: cognitive functions, schizophrenia, gender differences, sex hormones, memory, attention, neuropsychological, psychopatological symptoms. Results: Most of the analyzed papers reflecting the cognitive differences between men and women suffering from schizophrenia postulate a worse performance in neuropsychological test by male patients. However according to some authors there are no gender differences in cognitive functioning in schizophrenic patients or those differences are not clinically significant. Conclusions: The problem of sex-specific differences in cognitive functioning in patients in schizophrenia needs further investigation

    Minimal H\"older regularity implying finiteness of integral Menger curvature

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    We study two families of integral functionals indexed by a real number p>0p > 0. One family is defined for 1-dimensional curves in R3\R^3 and the other one is defined for mm-dimensional manifolds in Rn\R^n. These functionals are described as integrals of appropriate integrands (strongly related to the Menger curvature) raised to power pp. Given p>m(m+1)p > m(m+1) we prove that C1,αC^{1,\alpha} regularity of the set (a curve or a manifold), with α>α0=1m(m+1)p\alpha > \alpha_0 = 1 - \frac{m(m+1)}p implies finiteness of both curvature functionals (m=1m=1 in the case of curves). We also show that α0\alpha_0 is optimal by constructing examples of C1,α0C^{1,\alpha_0} functions with graphs of infinite integral curvature

    Peralkaline felsic magmatism at the Nemrut volcano, Turkey: impact of volcanism on the evolution of Lake Van (Anatolia) IV

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    Nemrut volcano, adjacent to Lake Van (Turkey), is one of the most important peralkaline silicic centres in the world, where magmatism for ~570,000 years has been dominated by peralkaline trachytes and rhyolites. Using onshore and Lake Van drill site tephra samples, we document the phenocryst and glass matrix compositions, confirming a complete spectrum from very rare mafic to dominantly silicic magmas. Magma mixing has been common and, along with the multi-lineage nature of the magmas, indicates that Nemrut has been a very open system where, nevertheless, compositionally zoned caps developed during periods of relative eruptive quiescence. Geothermometry suggests that the intermediate-silicic magmas evolved in an upper crustal magma reservoir at temperatures between 1100 and 750 °C, at fO2 close to the FMQ buffer. The silicic magmas either were halogen poor or exsolved a halogen-rich phase prior to or during eruption. An unusual Pb-rich phase, with up to 98.78 wt% PbO, is interpreted as having exsolved from the intermediate-rhyolitic magmas

    Novel organic material induced by electron beam irradiation for medical application

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    This study analyzed the e ects of irradiation of polytetrafluoroethylene (PTFE) containing 40% of bronze using an electron beam with energy of 10 MeV. Dosages from 26 to156 kGy (2.6–15.6 Mrad) were used. The impact of a high-energy electron beam on the thermal, spectrophotometric, mechanical, and tribological properties was determined, and the results were compared with those obtained for pure PTFE. Thermal properties studies showed that such irradiation caused changes in melting temperature Tm and crystallization temperature Tc, an increase in crystallization heat DHc, and a large increase in crystallinity c proportional to the absorbed dose for both polymers. The addition of bronze decreased the degree of crystallinity of PTFE by twofold. Infrared spectroscopy (FTIR) studies confirmed that the main phenomenon associated with electron beam irradiation was the photodegradation of the polymer chains for both PTFE containing bronze and pure PTFE. This had a direct e ect on the increase in the degree of crystallinity observed in DSC studies. The use of a bronze additive could lead to energy dissipation over the additive particles. An increase in hardness H and Young’s modulus E was also observed. The addition of bronze and the irradiation with an electron beam improved of the operational properties of PTFE

    Copper(II) complexes of functionalized 2,2’:6’,2’’-terpyridines and 2,6-di(thiazol-2-yl)pyridine : structure, spectroscopy, cytotoxicity and catalytic activity

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    Six new copper(II) complexes with 2,2’:6’,2’’-terpyridine (4’-Rn-terpy) [1 (R1 = furan-2-yl), 2 (R2 = thiophen- 2-yl), and 3 (R3 = 1-methyl-1H-pyrrol-2-yl)] and 2,6-di(thiazol-2-yl)pyridine derivatives (Rn-dtpy) [4 (R1), 5 (R2), and 6 (R3)] have been synthesized by a reaction between copper(II) chloride and the corresponding ligand. The complexes have been characterized by UV-vis and IR spectroscopy, and their structures have been determined by X-ray analysis. The antiproliferative potential of copper(II) complexes of 2,2’:6’,2’’-terpyridine and 2,6-di(thiazol-2-yl)pyridine derivatives towards human colorectal (HCT116) and ovarian (A2780) carcinoma as well as towards lung (A549) and breast adenocarcinoma (MCF7) cell lines was examined. Complex 1 and complex 6 were found to have the highest antiproliferative effect on A2780 ovarian carcinoma cells, particularly when compared with complex 2, 3 with no antiproliferative effect. The order of cytotoxicity in this cell line is 6 > 1 > 5 > 4 > 2 ≈ 3. Complex 2 seems to be much more specific towards colorectal carcinoma HCT116 and lung adenocarcinoma A549 cells. The viability loss induced by the complexes agrees with Hoechst 33258 staining and typical morphological apoptotic characteristics like chromatin condensation and nuclear fragmentation. The specificity towards different types of cell lines and the low cytotoxic activity towards healthy cells are of particular interest and are a positive feature for further developments. Complexes 1–6 were also tested in the oxidation of alkanes and alcohols with hydrogen peroxide and tert-butyl-hydroperoxide (TBHP). The most active catalyst 4 gave, after 120 min, 0.105 M of cyclohexanol + cyclohexanone after reduction with PPh3. This concentration corresponds to a yield of 23% and TON = 210. Oxidation of cis-1,2-dimethylcyclohexane with m-CPBA catalyzed by 4 in the presence of HNO3 gave a product of a stereoselective reaction (trans/cis = 0.47). Oxidation of secondary alcohols afforded the target ketones in yields up to 98% and TON = 630
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