701 research outputs found
The eta transition form factor from space- and time-like experimental data
The transition form factor is analysed for the first time in both
space- and time-like regions at low and intermediate energies in a
model-independent approach through the use of rational approximants. The
experimental data provided by the A2
Collaboration in the very low energy region of the dilelectron invariant mass
distribution allows for the extraction of the most precise up-to-date slope and
curvature parameters of the form factors as well as their values at zero and
infinity. The impact of these new results on the mixing parameters of the
- system, together with the role played by renormalisation
dependent effects, and on the determination of the couplings from
and radiative decays are also discussed.Comment: 16 pages, 17 figures; v2: additional comments, references added;
mathces published version in EPJ
Gross output and livestock sales modelling in Spanish extensive farms using PLSR
The aim of this paper is to model some production variables in extensive livestock farms located in the dehesa ecosystem. We intend to use not only purely economic variables in the construction of the model, but also structural variables in order to identify the characteristics of the farms that have the higher influence. Another objective is to be able to predict these variables at the farm level, using structural variables that are easy to measure. The data used in this work were obtained from a questionnaire survey to the holders/managers of a sample of 69 dehesa farms in Extremadura (SW Spain). The statistical methodology used for the construction of the model was Partial Least Square Regression (PLSR). It can be concluded that the variables relative to farm intensification, to labour and especially to Iberian pig breeding, are those that take part mainly in the model.dehesa, livestock farming systems, partial least square regression, gross output, Crop Production/Industries, Livestock Production/Industries, Research Methods/ Statistical Methods,
3D high definition video coding on a GPU-based heterogeneous system
H.264/MVC is a standard for supporting the sensation of 3D, based on coding from 2 (stereo) to N views. H.264/MVC adopts many coding options inherited from single view H.264/AVC, and thus its complexity is even higher, mainly because the number of processing views is higher. In this manuscript, we aim at an efficient parallelization of the most computationally intensive video encoding module for stereo sequences. In particular, inter prediction and its collaborative execution on a heterogeneous platform. The proposal is based on an efficient dynamic load balancing algorithm and on breaking encoding dependencies. Experimental results demonstrate the proposed algorithm's ability to reduce the encoding time for different stereo high definition sequences. Speed-up values of up to 90× were obtained when compared with the reference encoder on the same platform. Moreover, the proposed algorithm also provides a more energy-efficient approach and hence requires less energy than the sequential reference algorith
Die neuen Länder und ihre Verfassungen
The relationship between Rapid Automatized Naming (RAN) tasks and reading proficiency was first studied for English during the 70s, one finding being that children with dyslexia were slow and inconsistent in the RAN tasks. Later on, some studies have confirmed that RAN is the best predictor for transparent ortographies - and so of particular interest for Spanish. The research done so far on RAN and reading in Spanish is therefore reviewed here in order to draw conclusions for the diagnosis and treatment of reading difficulties. Our review shows that RAN is both a powerful early predictor of future reading outcomes and capable of discriminating between typical and poor readers. Being very easy to test, RAN is thus of great use in the diagnosis and prevention of reading disorders in Spanish
The Relationship Between Bound Water and Carbohydrate Reserves in Association with Cellular Integrity in Fragaria vesca Stored Under Different Conditions
Expression Profiles and DNA-Binding Affinity of Five ERF Genes in Bunches of Vitis vinifera cv. Cardinal Treated with High Levels of CO2 at Low Temperature
Ethylene response factors (ERFs) play an important role in plants by regulating defense response through interaction with various stress pathways. After harvest, table grapes (Vitis vinifera L.) are subject to a range of problems associated with postharvest storage at 0°C, such as fungal attack, water loss and rachis browning. The application of a 3-day high CO2 treatment maintained fruit quality and activated the induction of transcription factors belonging to different families such as ERF. In this paper, we have isolated five VviERFs from table grapes cv. Cardinal, whose deduced amino acid sequence contained the conserved apetalous (AP2)/ERF domain. The phylogeny and putative conserved motifs in VviERFs were analyzed and compared with those previously reported in Vitis. VviERFs-c gene expression was studied by quantitative real-time RT-PCR in the different tissues of bunches stored at low temperature and treated with high levels of CO2. The results showed that in most of the tissues analyzed, VviERFs-c gene expression was induced by the storage under normal atmosphere although the application of high levels of CO2 caused a greater increase in the VviERFs-c transcript accumulation. The promoter regions of two PRs (pathogenesis related proteins), Vcchit1b and Vcgns1, were obtained and the in silico analysis revealed the presence of a cis-acting ethylene response element (GCC box). In addition, expression of these two PR genes was analyzed in the pulp and rachis of CO2-treated and non-treated table grapes stored at 0°C and results showed significant correlations with VviERF2-c and VviERF6L7-c gene expression in rachis, and between VviERF11-c and Vcchit1b in pulp. Finally by using electro mobility shift assays, we denoted differences in binding of VviERFs to the GCC sequences present in the promoters of both PRs, with VviERF6L7-c being the only member which did not bind to any tested probe. Overall, our results suggest that the beneficial effect of high CO2 treatment maintaining table grape quality seems to be mediated by the regulation of ERFs and in particular VviERF2-c might play an important role by modulating the expression of PR genes.This work was supported by the European Union under the 7th Framework Programme FP7-PEOPLE-2012-CIG no. 321694 and by CICYT projects AGL2011-26742 and AGL2014-53081-R. IR and MV-H were supported by a postdoctoral Juan de la Cierva contract from the MICINN and a predoctoral contract from the MEC, respectively.USD 2,116.5 APC fee funded by the EC FP7 Post-Grant Open Access PilotPeer reviewe
Small-scale variation of vegetation in a mixed forest understorey is partly controlled by the effect of overstory composition on litter accumulation
We investigated how richness and composition of vascular plant species in the understory of a mixed hardwood forest stand varied with respect to the abundance and composition of the overstory. The stand is in central Spain and represents the southernmost range of distribution of several tree and herbaceous species in Europe. Understory species were identified in 46 quadrats (0.25 m2) where variables litter depth and light availability were measured. In addition, we estimated tree density, basal area, and percent basal area by tree species within 6-m-radius areas around each plot. Species richness and composition were studied using path analysis and scale-dependent geostatistical methods, respectively. We found that the relative abundance of certain trees species in the overstory was more important than total overstory abundance in explaining understory species richness. Richness decreased as soil litter depth increased, and soil litter increased as the relative proportion of Fagus sylvatica in the overstory increased, which accounted for a negative, indirect effect of Fagus sylvatica on richness. Regarding understory species composition, we found that some species distributed preferentially below certain tree species. For example, Melica uniflora was most frequent below Fagus sylvatica and Quercus petraea while the increasing proportion of Q. pyrenaica in the overstory favored the presence of Cruciata glabra, Arenaria montana, Prunus avium, Conopodium bourgaei, Holcus mollis, Stellaria media and Galium aparine in the understory. Overall, these results emphasize the importance of individual tree species in controlling the assemblage and richness of understory species in mixed stands. We conclude that soil litter accumulation is one way through which overstory composition shapes the understory community
A combined study of hadronic and decays by means of the analysis of semileptonic decays
We perform a combined study of the two hadronic decays
and using a detailed analysis of the semileptonic decays
() thanks to the high-statistics
dataset provided by the BESIII Collaboration. We propose simple and suitable
amplitude parametrizations of the studied reactions that shall be of interest
to experimentalists for upcoming analyses. These new parametrizations are based
on the na\"ive factorization hypothesis and the description of the resulting
matrix elements in terms of well-known hadronic form factors, with special
emphasis on the scalar and vector cases. Such form factors account for
two-body final state interactions which fulfill analyticity, unitarity and
chiral symmetry constraints. As a result of our study, we find that the
-wave contribution fits nicely within the na\"ive-factorization approach,
whereas the -wave contribution requires complex Wilson coefficients that
hint for possibly genuine three-body non-factorizable effects. Our hypothesis
is further supported by the examination of decays, where
we achieve a description in overall good agreement with data.Comment: 23 pages, 8 figures; version accepted for publication in Phys.Rev.
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