545 research outputs found
EURATOM EC 7th framework program. Collaborative project \u27redox phenomena controlling systems\u27. 1st annual workshop proceedings
Comparative study of online shopping methods in Spain
Este artículo realizará un análisis de los distintos métodos de compra online que hay disponibles para los consumidores españoles profundizando en el método de compra puramente online, el show-rooming, el ROPO, el BOPIS y el BORIS. Tras este análisis se hará una comparativa de cuáles son los métodos de compra preferidos por los compradores españoles tras la pandemia de la COVID-19 y las posibles causas de esta decisión.
This article will analyse the different online shopping methods available to Spanish consumers, focusing on the purely online shopping method, show-rooming, ROPO, BOPIS and BORIS. This analysis will be followed by a comparison of which shop-ping methods are preferred by Spanish shoppers after the COVID-19 pandemic and the possible causes of this decision
Testing reflection features in 4U 1705-44 with XMM-Newton, BeppoSAX and RXTE in the hard and soft state
We use data of the bright atoll source 4U 1705-44 taken with XMM-Newton,
BeppoSAX and RXTE both in the hard and in the soft state to perform a
self-consistent study of the reflection component in this source. Although the
data from these X-ray observatories are not simultaneous, the spectral
decomposition is shown to be consistent among the different observations, when
the source flux is similar. We therefore select observations performed at
similar flux levels in the hard and soft state in order to study the spectral
shape in these two states in a broad band (0.1-200 keV) energy range, with good
energy resolution, and using self-consistent reflection models. These
reflection models provide a good fit for the X-ray spectrum both in the hard
and in the soft state in the whole spectral range. We discuss the differences
in the main spectral parameters we find in the hard and the soft state,
respectively, providing evidence that the inner radius of the optically thick
disk slightly recedes in the hard state.Comment: Accepted for publication in A&A, 20 pages, 12 figure
From equator to pole:Splitting chromosomes in mitosis and meiosis
During eukaryotic cell division, chromosomes must be precisely partitioned to daughter cells. This relies on a mechanism to move chromosomes in defined directions within the parental cell. While sister chromatids are segregated from one another in mitosis and meiosis II, specific adaptations enable the segregation of homologous chromosomes during meiosis I to reduce ploidy for gamete production. Many of the factors that drive these directed chromosome movements are known, and their molecular mechanism has started to be uncovered. Here we review the mechanisms of eukaryotic chromosome segregation, with a particular emphasis on the modifications that ensure the segregation of homologous chromosomes during meiosis I
Assessment of the evolution of the redox conditions in a low and intermediate level nuclear waste repository (SFR1, Sweden)
The evaluation of the redox conditions in an intermediate and low level radioactive waste repository such as SFR1 (Sweden) is of high relevance in the assessment of its future performance. The SFR1 repository contains heterogeneous types of wastes, of different activity levels and with very different materials, both in the waste itself and as immobilisation matrices and packaging. The level of complexity also applies to the different reactivity of the materials, so that an assessment of the uncertainties in the study of how the redox conditions would evolve must consider different processes, materials and parameters. This paper provides an assessment of the evolution of the redox conditions in the SFR1. The approach followed is based on the evaluation of the evolution of the redox conditions and the reducing capacity in 15 individual waste package types, selected as being representative of most of the different waste package types present or planned to be deposited in the SFR1. The model considers different geochemical processes of redox relevance in the system. The assessment of the redox evolution of the different vaults of the repository is obtained by combining the results of the modelled individual waste package types. According to the model results, corrosion of the steel-based material present in the repository keeps the system under reducing conditions for long time periods. The simulations have considered both the presence and the absence of microbial activity. In the initial step after the repository closure, the microbial mediated oxidation of organic matter rapidly causes the depletion of oxygen in the system. The system is afterwards kept under reducing conditions, and hydrogen is generated due to the anoxic corrosion of steel. The times for exhaustion of the steel contained in the vaults vary from 5 ky to more than 60 ky in the different vaults, depending on the amount and the surface area of steel. After the complete corrosion of steel, the system still keeps a high reducing capacity, due to the magnetite formed as steel corrosion product. The redox potential in the vaults is calculated to evolve from oxidising at very short times, due the initial oxygen content, to very reducing at times shorter than 5 years after repository closure. The redox potential imposed by the anoxic corrosion of steel and hydrogen production is on the order of -0.75 V at pH 12.5. In case of assuming that the system responds to the Fe(III)/Magnetite system, and considering the uncertainty in the pH due to the degradation of the concrete barriers, the redox potential would be in the range -0.7 to -0.01V. A Monte-Carlo probabilistic analysis on the rate of corrosion of steel shows that the reducing capacity of the system provided by magnetite is not exhausted at the end of the assessment period, even assuming the highest corrosion rates for steel. Simulations assuming presence of oxic water due to glacial melting, intruding the system 60 ky after repository closure, indicate that magnetite is progressively oxidised, forming Fe(III) oxides. The time at which magnetite is completely oxidised varies depending on the amount of steel initially present in the waste package. The behaviour of Np, Pu, Tc and Se under the conditions foreseen for this repository is discussed
Comparison of two non-invasive arterial blood pressure monitoring techniques in brown bears (Ursus arctos)
Monitoring arterial blood pressure (BP), represents a more accurate evaluation of hemodynamics than heart rate alone and is essential for preventing and treating infra- and post-operative complications in wildlife chemical immobilization.The objectives of the study were to test the correlation between standard oscillometry and Korotkoffs technique in anesthetized free-ranging brown bears in Croatia and Scandinavia and to assess the blood pressure in both locations.Five bears were snared and darted with xylazine and ketamine in Croatia, and 20 bears were darted from a helicopter with medetomidine and tiletamine-zolazepam in Scandinavia. Blood pressure was simultaneously measured with both techniques every 5 minutes. Correlation between techniques, trends of BP variation, and the factors of the capture which likely influenced BP were assessed.Successful measurements of BP were achieved in 93% of all attempts with the Korotkoffs technique but in only 29% of all attempts with oscillometry. The latter method mostly provided lower values of BP compared to Korotkoffs technique in yearlings. Most bears showed a decreasing trend in systolic and mean BP over time, consistent between the two techniques. All bears were hypertensive: the auscultatory technique detected moderate to severe systolic hypertension in 25% and 84% of bears in Croatia and in Scandinavia, respectively, with significantly higher BP in subadults and adults compared to yearlings. Only Korotkoffs method resulted in a reliable and effective tool for BP assessment in brown bears. The anesthetic protocols used in the present study in association with the capture methods produced hypertension in all animals
One-Pot Synthesis of Oxidation-Sensitive Supramolecular Gels and Vesicles
Polypeptide-based nanoparticles offer unique advantages from a nanomedicine perspective such as biocompatibility, biodegradability, and stimuli-responsive properties to (patho)physiological conditions. Conventionally, self-assembled polypeptide nanostructures are prepared by first synthesizing their constituent amphiphilic polypeptides followed by postpolymerization self-assembly. Herein, we describe the one-pot synthesis of oxidation-sensitive supramolecular micelles and vesicles. This was achieved by polymerization-induced self-assembly (PISA) of the N-carboxyanhydride (NCA) precursor of methionine using poly(ethylene oxide) as a stabilizing and hydrophilic block in dimethyl sulfoxide (DMSO). By adjusting the hydrophobic block length and concentration, we obtained a range of morphologies from spherical to wormlike micelles, to vesicles. Remarkably, the secondary structure of polypeptides greatly influenced the final morphology of the assemblies. Surprisingly, wormlike micellar morphologies were obtained for a wide range of methionine block lengths and solid contents, with spherical micelles restricted to very short hydrophobic lengths. Wormlike micelles further assembled into oxidation-sensitive, self-standing gels in the reaction pot. Both vesicles and wormlike micelles obtained using this method demonstrated to degrade under controlled oxidant conditions, which would expand their biomedical applications such as in sustained drug release or as cellular scaffolds in tissue engineering
Asymptotic expansions of the solutions of the Cauchy problem for nonlinear parabolic equations
Let be a solution of the Cauchy problem for the nonlinear parabolic
equation and
assume that the solution behaves like the Gauss kernel as . In
this paper, under suitable assumptions of the reaction term and the initial
function , we establish the method of obtaining higher order
asymptotic expansions of the solution as . This paper is a
generalization of our previous paper, and our arguments are applicable to the
large class of nonlinear parabolic equations
Proceedings of the First Annual Workshop of the HORIZON 2020 CEBAMA Project (KIT Scientific Reports ; 7734)
The Proceedings of the First Annual Workshop of the Collaborative Project CEBAMA addresses key scientific questions related to the use of cement-based materials in nuclear waste disposal applications. Progress beyond the state-of-the-art is achieved by providing basic knowledge, new experimental data, improved modeling and arguments for the Nuclear Waste Disposal Safety Case. CEBAMA is funded by the European Commission under the Horizon 2020 frame of EURATOM
Different aspects of workflow scheduling in large-scale distributed systems
As large-scale distributed systems gain momentum, the scheduling of workflow applications with multiple requirements in such computing platforms has become a crucial area of research. In this paper, we investigate the workflow scheduling problem in large-scale distributed systems, from the Quality of Service (QoS) and data locality perspectives. We present a scheduling approach, considering two models of synchronization for the tasks in a workflow application: (a) communication through the network and (b) communication through temporary files. Specifically, we investigate via simulation the performance of a heterogeneous distributed system, where multiple soft real-time workflow applications arrive dynamically. The applications are scheduled under various tardiness bounds, taking into account the communication cost in the first case study and the I/O cost and data locality in the second.The work presented in this paper has been partially supported by EU, under the COST program Action IC1305, “Network for Sustainable Ultrascale Computing (NESUS)”, and by the Ministerio de Economía y Competitividad, Spain, under the project TIN2013-41350-P, “Scalable Data Management Techniques for High-End Computing Systems”
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