3,134 research outputs found

    Early Christian Basilicas in Crimea and their Numeric Proportions

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    The focus of this study is to determine the extent to which numeric (as opposed to geometric) proportions were employed in Christian basilicas of Crimea and which specific numeric proportions were applied; it also attempts to explain why certain proportions may have been chosen by the builders. Numeric proportions were identified in 14 basilicas of Crimea: 10 in Chersonesos, two on the plateaus of Mangup-Kale and Eski-Kermen in southwest Crimea, one in Partenit on the south coast and one in Tyritake, south of modern Kerch at the east end of Crimea. Most reviewed basilicas have reasonably been attributed to the 6th and early 7th centuries based largely upon archaeological evidence.Данная статья является измененной и расширенной выдержкой из более масштабного исследования, посвященного изучению пропорций христианских базилик большинства регионов Средиземноморского и Черноморского бассейнов и Кавказа с IV по VII столетия [1]. Оно сосредоточено на числовых, а не геометрических пропорциях, которые, возможно, также использовались в некоторых объектах, но до сих пор не исследовались. Числовые пропорции состоят из отношений целых чисел, в то время какгеометрические пропорции построены на геометрических конфигурациях, таких как квадраты или круги и их производных. Цель этой статьи состоит в том, чтобы определить, в каких пределах использовались числовые пропорции в христианских базиликах Крыма, какие специфические пропорции здесь применялись; а также попытаться объяснить, почему те или иные пропорции могли быть выбраны строителями.Ціль даної статті полягає у визначенні ступеню поширення використання числових (на відміну від геометричних) пропорцій у християнських базиліках Криму, а також у тому, щоб виявити специфічні числові пропорції, які тут застосовувалися; крім того, спробувати пояснити, чому ті чи інші пропорції могли бути обрані будівниками. Були визначені числові пропорції 14 базилік Криму: серед них 10 у Херсонесі, по одній на плато Мангуп-Кале и Ескі-Кермен у Південно-Західному Криму, у Партеніті, на південному березі та у Тиритаці, на сході Криму. Більшість досліджених базилік датуються VI – початком VII ст. головним чином на підставі археологічних свідчень

    Editors’ Comment: Bariatrics and Diabetes Meta-Analysis

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    Rechnerische Bestimmung der lonenbeweglichkeit in Ziegelstein unter Zuhilfenahme von Ergebnissen aus nichtstationären Diffusionsversuchen

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    Ion concentration profiles in sandwich-brick specimens have been determined experimentally at different degrees of water saturation. Based on the experimental data, ion diffusion coefficients were determined by inverse analysis. The diffusion equation served as a basis for an optimization technique. It has been shown that the ion diffusivity in bricks decreases markedly as the moisture content decreases. The interface between two adjacent bricks slows down the ion migration at low water content in particular. It is planed to investigate the interface between mortar and bricks in further experimental and numerical studie

    Tunable two-dimensional plasmon resonances in an InGaAs/InP high electron mobility transistor

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    Voltage-tunable plasmon resonances in the two-dimensional electron gas (2DEG) of a high electron mobility transistor (HEMT) fabricated from the InGaAs/InP materials system are reported. The device was fabricated from a commercial HEMT wafer by depositing source and drain contacts using standard photolithography and a semitransparent gate contact that consisted of a 0.5 mu m period transmission grating formed by electron-beam lithography. Narrow-band resonant absorption of terahertz radiation was observed in transmission in the frequency range of 10-50 cm(-1). The resonance frequency depends on the gate-tuned sheet charge density of the 2DEG. The observed separation of resonance fundamental from its harmonics and their shift with gate bias are compared with theory

    Decoy oligodeoxynucleotide againstactivator protein-1 reducesneointimal proliferation after coronaryangioplasty in hypercholesterolemic minipigs

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    AbstractObjectivesWe sought to demonstrate, in an appropriate animal model, that co-medication with a transcription factor-blocking agent limits restenosis after percutaneous transluminal coronary angioplasty (PTCA).BackgroundEnhanced synthesis in the vessel wall of endothelin-1 (ET-1), a powerful co-mitogen for vascular smooth muscle cells, appears to be one mechanism that promotes restenosis after PTCA. Deformation-induced expression of prepro-ET-1 is governed by the transcription factor, activator protein-1 (AP-1).MethodsAn anti-AP-1 decoy oligodeoxynucleotide (dODN) strategy was devised in which the dODN-containing solution (20 nmol) was administered locally through a Dispatch catheter into the coronary arteries of hypercholesterolemic minipigs at the time of PTCA (AVE-GFX stent).ResultsTreatment with an AP-1 dODN, mimicking the consensus binding site of the transcription factor, significantly reduced neointimal formation in the coronary arteries of hypercholesterolemic minipigs (n = 10 to 12), compared with vehicle-treated coronary arteries, after four weeks of follow-up (neointimal area 2.64 ± 0.33 vs. 4.81 ± 1.04 mm2[mean ± SEM]; p < 0.05). This effect was maintained after eight weeks (neointimal area 2.04 ± 0.22 mm2; n = 3) and correlated with a reduction in both nuclear translocation of AP-1 and ET-1 synthesis in the vessel wall 48 h after PTCA (n = 4). In contrast, an AP-1 mutant dODN, to which the transcription factor does not bind, showed no effect on neointimal formation at either time point (n = 3 to 7). Moreover, a consensus dODN directed against CCAAT/enhancer binding protein (C/EBP), another deformation-sensitive transcription factor, did not significantly affect neointimal formation after four weeks (n = 3).ConclusionsThese findings demonstrate the feasibility, efficacy and specificity of the anti-AP-1 dODN approach to the treatment of restenosis, which principally but not exclusively targets deformation-induced ET-1 synthesis in the vessel wall. Provided that these findings can be extrapolated to the situation of patients with coronary artery disease, the observed extent of the inhibitory effect of the AP-1 dODN treatment suggests that this co-medication may greatly reduce the incidence of in-stent restenosis

    Absence of a consistent classical equation of motion for a mass-renormalized point charge

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    The restrictions of analyticity, relativistic (Born) rigidity, and negligible O(a) terms involved in the evaluation of the self electromagnetic force on an extended charged sphere of radius "a" are explicitly revealed and taken into account in order to obtain a classical equation of motion of the extended charge that is both causal and conserves momentum-energy. Because the power-series expansion used in the evaluation of the self force becomes invalid during transition time intervals immediately following the application and termination of an otherwise analytic externally applied force, transition forces must be included during these transition time intervals to remove the noncausal pre-acceleration and pre-deceleration from the solutions to the equation of motion without the transition forces. For the extended charged sphere, the transition forces can be chosen to maintain conservation of momentum-energy in the causal solutions to the equation of motion within the restrictions of relativistic rigidity and negligible O(a) terms under which the equation of motion is derived. However, it is shown that renormalization of the electrostatic mass to a finite value as the radius of the charge approaches zero introduces a violation of momentum-energy conservation into the causal solutions to the equation of motion of the point charge if the magnitude of the external force becomes too large. That is, the causal classical equation of motion of a point charge with renormalized mass experiences a high acceleration catastrophe.Comment: 13 pages, No figure

    Nitrogen cycling in the secondary nitrite maximum of the eastern tropical North Pacific off Costa Rica

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    Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Global Biogeochemical Cycles 29 (2015): 2061–2081, doi:10.1002/2015GB005187.Nitrite is a central intermediate in the marine nitrogen cycle and represents a critical juncture where nitrogen can be reduced to the less bioavailable N2 gas or oxidized to nitrate and retained in a more bioavailable form. We present an analysis of rates of microbial nitrogen transformations in the oxygen deficient zone (ODZ) within the eastern tropical North Pacific Ocean (ETNP). We determined rates using a novel one-dimensional model using the distribution of nitrite and nitrate concentrations, along with their natural abundance nitrogen (N) and oxygen (O) isotope profiles. We predict rate profiles for nitrate reduction, nitrite reduction, and nitrite oxidation throughout the ODZ, as well as the contributions of anammox to nitrite reduction and nitrite oxidation. Nitrate reduction occurs at a maximum rate of 25 nM d−1 at the top of the ODZ, at the same depth as the maximum rate of nitrite reduction, 15 nM d−1. Nitrite oxidation occurs at maximum rates of 10 nM d−1 above the secondary nitrite maximum, but also in the secondary nitrite maximum, within the ODZ. Anammox contributes to nitrite oxidation within the ODZ but cannot account for all of it. Nitrite oxidation within the ODZ that is not through anammox is also supported by microbial gene abundance profiles. Our results suggest the presence of nitrite oxidation within the ETNP ODZ, with implications for the distribution and physiology of marine nitrite-oxidizing bacteria, and for total nitrogen loss in the largest marine ODZ.National Science Foundation. Grant Numbers OCE 05-26277, OCE 09-610998; WHOI Coastal Ocean Institute2016-06-1

    The time-profile of cell growth in fission yeast: model selection criteria favoring bilinear models over exponential ones

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    BACKGROUND: There is considerable controversy concerning the exact growth profile of size parameters during the cell cycle. Linear, exponential and bilinear models are commonly considered, and the same model may not apply for all species. Selection of the most adequate model to describe a given data-set requires the use of quantitative model selection criteria, such as the partial (sequential) F-test, the Akaike information criterion and the Schwarz Bayesian information criterion, which are suitable for comparing differently parameterized models in terms of the quality and robustness of the fit but have not yet been used in cell growth-profile studies. RESULTS: Length increase data from representative individual fission yeast (Schizosaccharomyces pombe) cells measured on time-lapse films have been reanalyzed using these model selection criteria. To fit the data, an extended version of a recently introduced linearized biexponential (LinBiExp) model was developed, which makes possible a smooth, continuously differentiable transition between two linear segments and, hence, allows fully parametrized bilinear fittings. Despite relatively small differences, essentially all the quantitative selection criteria considered here indicated that the bilinear model was somewhat more adequate than the exponential model for fitting these fission yeast data. CONCLUSION: A general quantitative framework was introduced to judge the adequacy of bilinear versus exponential models in the description of growth time-profiles. For single cell growth, because of the relatively limited data-range, the statistical evidence is not strong enough to favor one model clearly over the other and to settle the bilinear versus exponential dispute. Nevertheless, for the present individual cell growth data for fission yeast, the bilinear model seems more adequate according to all metrics, especially in the case of wee1Δ cells
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