Total electron scattering cross sections from thiophene for the (1-300 eV) impact energy range

Experimental electron scattering cross sections for thiophene in the impact energy range from 1 to 300 eV have been measured with a magnetically confined electron transmission-beam apparatus. Random uncertainty limits have been estimated to be less than 5%, and systematic errors derived from acceptance angle limitations have also been identified and evaluated. Experimental values are compared with our previous low energy (1-15 eV) R-matrix and intermediate/high energy (15-300 eV) IAM-SCAR+I calculations finding reasonable agreement, within the combined uncertainty limits. Some of the low energy shape and core-excited resonances predicted by previous calculations are experimentally confirmed in this study

Nanometric muon beam emittance from e + annihilation on multiple thin targets

The production of a low emittance muon beam is interesting for muon collider projects. In such context we study the production of positive and negative muon beams at 22 GeV, from ${e}^{+}$ beam-vs-fixed target collisions, with a very small transverse and longitudinal emittance of 25\text{ }\text{ }\ensuremath{\pi}\text{ }\mathrm{nm}\text{ }\mathrm{rad} and 3\ifmmode\times\else\texttimes\fi{}1\text{ }\text{ }\ensuremath{\pi}\text{ }\mathrm{mm}\text{ }\mathrm{GeV}, respectively. In order to cope with the small conversion efficiency of positrons into muon pairs and the divergence of the beams, we connect thin targets by a quadrupole-only transport line common to three beams ({\ensuremath{\mu}}^{+}, {\ensuremath{\mu}}^{\ensuremath{-}}, and ${e}^{+}$) at two different energies (\ensuremath{\mu} at 22 GeV and ${e}^{+}$ at 44 GeV), where the line is specially designed to match the muon beam phase space over \ifmmode\pm\else\textpm\fi{}5% energy spread and to mitigate the effect of multiple scattering with the targets on all beams. The transport line allows us to use a larger fraction of target material, increasing the muon population by a factor of 10 per positron bunch and splitting the power deposition over 20 to 40 targets, while keeping the muon beam emittance equal or similar to one from a single thin target of 1% of a radiation length. It might be possible to integrate this line into an accumulator ring in order to increase the muon bunch population over hundreds of positron bunches

A comparative performance evaluation of different implementations of the SOAP protocol

Abstract—This paper presents a study evaluation of the SOAP [1] protocol performance between two different implementations: Java (Axis2) [2] and Erlang. This comparison has been carried out using several testbeds with input and output data of different sizes. More concretely, we developed three different web services representing typical scenarios likely to be found in real environments. The evaluation is two-fold: we measured both the number of requests per second answered (throughput) by each server and the response to a common server workload, mixing stress and stand-by phases. The Erlang [3] functional programming language claims to be especifically designed and suited for distributed, reliable and soft real-time concurrent systems. Morever, its built-in lightweight processes management and easeness of replication within distributed environments stand out Erlang as an appealing choice for service oriented architectures (SOAs) [4]. On the other hand, we compared this new approximation with the well-known Apache Axis2 project, as it is widely employed on the Web Services field by the Java community. This work allows us to conclude that the Erlang server is more suitable when the computational cost of the web service is low, whereas the Axis2 server is more efficient as the service workload increases. I

Down-regulation of a pectin acetylesterase gene modifies strawberry fruit cell wall pectin stracture and increases fruit firmness

Antisense-mediated down-regulation of several fruit-specific genes has previously demonstrated how the cell wall disassembly in strawberry fruit is mediated by a series of enzymes that act sequentially (Posé et al. 2011). An interesting example, the silencing of the polygalacturonase gene FaPG1, was also related with a significant increase of the post-harvest strawberry fruit firmness (Posé et al. 2013). Our research group has isolated a pectin acetylesterase gene, FaPAE1, which expression is enhanced during strawberry ripening. The main goal of this work was to elucidate the role of the degree of acetylation in cell wall integrity and fruit firmness through the antisense-mediated down-regulation of FaPAE1 in strawberry plants. Several transgenics lines were generated and 5 of them produced fruits 5-15% firmer than controls. Cell wall from ripe fruits was isolated from two independent transgenic lines and a control line, and sequentially extracted with different solvents (PAW, H2O, CDTA, Na2CO3). Modifications in fraction yield, its sugar composition and the degree of acetylation in each fraction were determined. Higher amounts of CDTA and Na2CO3 fractions were obtained in transgenic fruits, suggesting a decreased pectin solubilization as results of FaPAE1 silencing. Accordingly, the degree of acetylation of the Na2CO3-soluble pectins was greater in the transgenic lines than the control, but the opposite result was found in pectins from the CDTA fraction. These results suggest that PAE is preferentially active in pectis that are tightly bound to the cellulose-hemicellulose network and its activity could reduce the complexity of the cell wall structure, allowing that other hydrolytic enzymes could access the pectin chains. Thus, the increased fruit firmness observed in the transgenic FaPAE1 lines could be attributed to the direct effect of the silencing of the PAE enzyme and also to the indirect effect that the increase of the degree of acetylation of pectins has on the activity of other enzymes involved in the cell wall degradation. * Posé et al. (2011). Genes, Genomes and Genomics, 5 (Special Issue 1):40-48 * Posé et al. (2013). Plant Physiology, 150: 1022-1032 We acknowledge support from the Spanish Ministry of Economy and competitivity and Feder EU Funds (grant reference AGL2011-24814), FPI fellowships support for SP (BES-2006-13626) and CP (BES-2009027985), and grant "Ramón y Cajal" support for AJMA (RYC-2011-08839).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

When the catenary degree agrees with the tame degree in numerical semigroups of embedding dimension three

We characterize numerical semigroups of embedding dimension three having the same catenary and tame degrees.García Sánchez is supported by the projects MTM2010-15595, FQM-343, FQM-5849, and FEDER funds. The contents of this article are part of Viola’s master’s thesis. Part of this work was done while she visited the Univerisidad de Granada under the European Erasmus mobility program

Spontaneous light emission in complex nanostructures

The spontaneous emission of an excited atom surrounded by different materials is studied in the framework of a semiclassical approach, where the transition dipole moment acts as the source of the emission field. The emission in the presence of semiinfinite media, metallic nanorings, spheres, gratings, and other complex geometries is investigated. Strong emission enhancement effects are obtained in some of these geometries associated to the excitation of plasmons (e.g., in nanorings or spheres). Furthermore, the emission is shown to take place only along narrow angular distributions when the atom is located inside a low-index dielectric and near its planar surface, or when metallic nanogratings are employed at certain resonant wave lengths. In particular, axially symmetric gratings made of real silver metal are considered, and both emission rate enhancement and focused far-field emission are achieved simultaneously when the grating is decorated with further nanostructures.This work has been supported in part by the Basque Departamento de Educacion, Universidades e Investigacion, the University of the Basque Country UPV/EHU (Contract No. 00206.215-13639/2001) and the Spanish Ministerio de Ciencia y Tecnologia (Contract No. MAT2001-0946).Peer reviewe

The relation between segment disclosure and earnings quality

We investigate the relation between segment disclosure and earnings quality. Using a US sample for the period 2001-2006, we find a positive relation between earnings quality and the quantity of segment disclosures. We use lead-lag tests to examine the flow of causality, and our results show that current segment disclosure is positively related to prior levels of earnings quality, while current earnings quality scores are not related to prior levels of segment disclosure. Thus, the causality flows from earnings quality to segment disclosure. Our results hold for both business and geographic segment disclosure.We acknowledge financial assistance from the Spanish Ministry of Innovation and Science (ECO2010-19314, ECO2008-06238-C02-01/ECON, SEJ2007-67582-C02-02/ECON, ECO2009-10796 and Consolider Grant #2006/04046/002), the European Commission INTACCT Research Training Network (MRTN-CT-2006-035850), and the government of the autonomous Community of Madrid (Grant # 2008/00037/001)

APFT: Active peer-based Flip Teaching

The Flip Teaching model1 (the lesson at home, the homework in class) has been used to actively engage students in their learning process during the lectures. In this method, passive learning (the lesson) is transferred to homework and the activity (exercises, debates, collaborative learning, etc.) to the class. More advanced Flip Teaching models carry out an intermediate phase in which the students can actively participate "at home", such as Micro Flip Teaching model. This model proposes an on-line activity composed by the learning of the lesson and the realization of an individual micro-activity on the same and then, in class, work on the obtained results in the micro-activity. In this work, the Micro Flip Teaching model has been adapted to carry out the online activity in a collaborative way in work teams. The main novelty of this proposal is that the active participation of the students generates resources that can be used as didactic material in future editions of the subject. To evaluate the impact of this proposal, an experimental group has been established that used resources generated by students from previous subject editions, while the control group used only resources generated by the teacher. The research shows that the resources generated by students are equally effective than those generated by teachers

Students' knowledge sharing to improve learning in academic engineering courses

This paper presents an example of scaffolding during the development of an engineering course, in which students are supported by teachers and other students. This proposal covers the benefits of the use of shared knowledge repositories in which content was created by students. Teamwork is the transversal competence that is considered to be the central knowledge topic. The cooperation among students through teamwork methodology has generated more than 500 learning resources and a knowledge management system, BRACO, which has been created with these resources to manage information and conduct searches according to each student''s profile and needs. The generated knowledge spiral is composed of knowledge circles that increase during each iteration of the action-research implementation. The reflection phase of this research consists of the evaluation of the impact on learning for students in the experimental group after using the knowledge resources generated by students in relation with teamwork competence, in contrast with the control group that does not experience this intervention. With regard to the assessments, several surveys and a learning analytics system, this paper explains the underlying methodological foundations and the empirical study. In comparison to the control group, the experimental group obtained better results in relation to indicators of positive learning results, such as studentstudent interaction, teamwork development and final grades during the teamwork process