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Evidence for a new compact symmetric fission mode in light thorium isotopes
No full textTaking benefit of theR3B=SOFIA setup to measure the mass and the nuclear charge of both fissionfragments in coincidence with the total prompt-neutron multiplicity, the scission configurations are inferredalong the thorium chain, from the asymmetric fission in the heavier isotopes to the symmetric fission in theneutron-deficient thorium. Against all expectations, the symmetric scission in the light thorium isotopesshows a compact configuration, which is in total contrast to what is known in the fission of the heavierthorium isotopes and heavier actinides. This new main symmetric scission mode is characterized by asignificant drop in deformation energy of the fission fragments of about 19 MeV, compared to the well-known symmetric scission in the uranium-plutonium regio.Centre National de la Recherche ScientifiqueEuropean Commission | Ref. ANDES-FP7-249671Ministerio de Ciencia e Innovación | Ref. FPA2010-22174-C0
Predictive phytotoxic value of water-soluble allelochemicals in plant extracts for choosing a cover crop or mulch for specific weed control
No full textCover crops and mulches have become an alternative for soil management in vineyards due to the agronomic, environmental, and economic advantages, especially the possibility of weed mme control. Implicitly to this objective lies the idea of assessing the potential herbicide effect of the allelochemicals released by different cover crops and mulch species. With this objective, the present work evaluated the phytotoxic effects of 12 aqueous extracts of selected species with potential use as a cover crop or mulch: a Bromus species mixture (B. hordeaceus L. and B. rubens L.), Festuca arundinacea Schreb., Hordeum murinum L., H. vulgare L., Vulpia ciliata Dumort., Medicago rugosa Desr., M. sativa L., Trifolium subterraneum L., T. incarnatum L., Phacelia tanacetifolia Benth., Sinapis alba L., and Pinus sylvestris L., on the germination and early growth of three troublesome weeds (Conyza bonariensis (L.) Cronquist, Aster squamatus (Spreng.) Hieron, and Bassia scoparia (L.) A. J.). The different in vitro bioassays showed that aqueous extracts of some species significantly inhibited or reduced germination and root and shoot growth of the target weed species in a dose-response manner. Germination of A. squamatus and C. bonariensis was reduced by 100-80% by the different extracts applied at 50% concentration and completely blocked at 100% concentration, except for M. rugosa extract, to which both species showed less sensitivity. Root elongation of A. squamatus was inhibited under every extract and concentration, whereas C. bonariensis root growth showed only some tolerance to the crude extracts of F. arundinacea and P. sylvestris. Bassia scoparia was relatively tolerant to the aqueous plant extracts, except for T. subterraneum crude extract, which reduced total germination by 80%; otherwise, B. scoparia showed higher general sensitivity of shoot growth than the other two weed species. The chemical profiles of phenolic compounds of the aqueous extracts were obtained and identified by HPLC-DAD, the phenolic profiles of H. murinum, V. ciliata, and M. rugosa being reported in this work for the first time. Using stepwise regression, the influence of certain phenolic compounds from the aqueous extracts on the cia germination and early growth of weeds was predicted. Among other significant compounds, the flavonoid naringenin identified in T. subterraneum aqueous extract at 8.09 µg·mL–1 was predicted to underlie its specific phytotoxicity on B. scoparia germination. These results support the use of cover crops and mulches in weed management and can help to select the most suitable species to adopt according to the target weed species.Ministerio de Economía y Competitividad | Ref. AGL2014-52465-C4-2-RAgencia Estatal de Investigación | Ref. AGL2017-83325-C4-2-RCentro para el Desarrollo Tecnológico y la Innovación (CDTI
On the determination of the interaction time of GeV neutrinos in large argon gas TPCs
No full textNext-generation megawatt-scale neutrino beams open the way to studying neutrino-nucleus scattering using gaseous targets for the first time. This represents an opportunity to improve the knowledge of neutrino cross sections in the energy region between hundreds of MeV and a few GeV, of interest for the upcoming generation of long-baseline neutrino oscillation experiments. The challenge is to accurately track and (especially) time the particles produced in neutrino interactions in large and seamless volumes down to few-MeV energies. We propose to accomplish this through an optically-read time projection chamber (TPC) filled with high-pressure argon and equipped with both tracking and timing functions. In this work, we present a detailed study of the time-tagging capabilities of such a device, based on end-to-end optical simulations that include the effect of photon propagation, photosensor response, dark count rate and pulse reconstruction. We show that the neutrino interaction time can be reconstructed from the primary scintillation signal with a precision in the range of 1–2.5 ns (σ) for point-like deposits with energies down to 5 MeV. A similar response is observed for minimum-ionizing particle tracks extending over lengths of a few meters. A discussion on previous limitations towards such a detection technology, and how they can be realistically overcome in the near future thanks to recent developments in the field, is presented. The performance demonstrated in our analysis seems to be well within reach of next-generation neutrino-oscillation experiments, through the instrumentation of the proposed TPC with conventional reflective materials and a silicon photomultiplier array behind a transparent cathode.Xunta de GaliciaGeneralitat Valenciana | Ref. CIDEGENT/2019/049Ministerio de Economía y Competitividad | Ref. RYC-2015-18820Agencia Estatal de Investigación | Ref. RYC2021-033265-IMinisterio de Economía, Industria y Competitividad | Ref. MDM-2016-0692Agencia Estatal de Investigación | Ref. PID2021-125028OB-C2
Coalition-weighted Shapley values
No full textWe introduce a new class of values for coalitional games: the coalition-weighted Shapley values.
Weights can be assigned to coalitions, not just to players, and zero-weights are admissible. The Shapley
value belongs to this class. Coalition-weighted Shapley values recommend for each game the allocation
defined by the Shapley value of a weighted game obtained as a linear convex combination of the associated
marginal games. Coalition-weighted Shapley values are random order values and Harsanyi values.
Positively weighted Shapley values and weighted Shapley values can be seen as the limit of a sequence of
iterated coalition-weighted Shapley values. We provide axiomatic characterizations of coalition-weighted
Shapley values through properties that do not involve the weights. Finally, we discuss how to extend our
model to include exogenous coalition structures as in the hierarchical and Owen values.Ministerio de Ciencia e Innovación | Ref. PID2021-124030NB-C33Xunta de Galicia | Ref. ED481A 2021/32
Capital humano, políticas públicas y crecimiento económico. Fundamentos y lecciones teóricas
No full textLa cuestión de la intervención estatal ha sido uno de los debates más significativos en la historia de la economía. Desde los inicios de la economía moderna, con Adam Smith, se ha defendido la no intervención del Estado en los mercados, una
postura que continuó siendo apoyada por la economía neoclásica. Hasta principios de la década de 1930, esta perspectiva dominaba el pensamiento económico. Sin embargo, entre 1910 y 1920, dentro del marco de la economía neoclásica, comenzó a surgir la idea de los fallos de mercado, lo que justificaba la
intervención estatal. Según los economistas de la época, estos fallos podíanocurrir bajo tres supuestos: 1. Competencia imperfecta; 2. Bienes públicos; 3. Externalidades. Cuando se presentan estas condiciones, la economía neoclásica aboga por la aplicación de intervenciones correctoras. Estos fallos, considerados microeconómicos, dieron lugar a una defensa limitada de la intervención estatal a principios del siglo XX.
A lo largo del siglo XX, la intervención estatal en la economía ha evolucionado significativamente. La Gran Depresión de los años 30 marcó un punto de inflexión, llevando a una mayor aceptación de la intervención estatal como necesaria para
corregir desequilibrios económicos y promover el bienestar general.Agencia Estatal de Investigación | Ref. RTI2018-099225-B-100Xunta de Galicia | Ref. ED431C2018/48Xunta de Galicia | Ref. ED431E2018/07Xunta de Galicia | Ref. ED481D 2023/00
Socioemotional skills and competences in education: a look at artistic and sports activities
No full textThis work focuses on the educational environment. The aim was to carry out an analysis of the scientific literature to find out the relationship between socioemotional skills and artistic or sports activities in this context. A systematic review was carried out using the Scopus database, and forty five documents were analyzed. The results showed the existence of proposals in both formal and nonformal settings; the variety of participants in different educational stages; intervention, research, and theoretical documents; the relationships between variables of various kinds, and the contents and methods developed. The results and the need to deepen the characteristics of the proposed programs and activities in order to provide maximum effectiveness in the learning of these skills are discussed
Water-soluble phenolic acids and flavonoids involved in the bioherbicidal potential of Ulex europaeus and Cytisus scoparius
No full textThe use of allelopathic foliage incorporated into the soil as a bioherbicidal amendment is a promising weed management strategy which allows combining a cocktail of allelochemicals at low effective individual con
centrations. In previous studies, the herbicidal potential of Ulex europaeus and Cytisus scoparius has been
argued to be mediated by volatile organic compounds (VOCs). The present work undertakes for the first time
the potential involvement of phenolic acids and flavonoids in the herbicidal bioactivity of both shrub species.
Such compounds are those most likely to be released to soil water when the allelopathic foliage is incorpo
rated into the soil. By dose-response in vitro bioassays of aqueous extracts, the flowering foliage of both shrub
species was shown to release water-soluble compounds capable of inhibiting the germination and/or early
growth of two agricultural weeds: Amaranthus retroflexus and Digitaria sanguinalis. Far from expected, such
phytotoxicity was enhanced when the aqueous extracts were applied to fresh soil. Via HPLC-DAD, 11 and 17
phenolic compounds were identified from U. europaeus and C. scoparius aqueous extracts, respectively, some
of them cited for the first time in both species. The phenolic acids trans-cinnamic, p-coumaric, and ferulic,
when were separately assayed in vitro at 1 mM, resulted phytotoxic to one or other target weed and physio
logical processes. However, except for the caffeic acid and vanillin, the phenolic acids lost effectiveness when
applied at lower concentrations (0.1 or 0.01 mM). Otherwise, it was noteworthy that the flavonoids luteolin,
ellagic acid, kaempferol, and naringenin were only phytotoxic when applied at low concentrations
( 0.1 mM).Theproven herbicidal efficiency of the shrub foliage was argued to derive from the phytotoxicity
of the water-soluble compounds assayed, and maybe from the combined or synergistic action with the VOCs
emitted from the fresh plant material.Agencia Estatal de Investigación | Ref. CGL2016-78660-RAgencia Estatal de Investigación | Ref. PID2019-111253RB-I0
Correction to “A PQ Model for Asynchronous Machines Based on Rotor Voltage Calculation” [Jun 16 813-814]
No full textPresents corrections to author names as well as several equations for the paper, "A PQ model for asynchronous machines based on rotor voltage calculation,” IEEE Trans. Energy Convers., to be published, doi: 10.1109/TEC.2016.252950
Correction to “A PQ Model for Asynchronous Machines Based on Rotor Voltage Calculation” [Jun 16 813-814]
No full textPresents corrections to the paper, "A PQ model for asynchronous machines based on rotor voltage calculation," (Feijoo, A. and Villanueva, D.), IEEE Trans. Energy Convers., vol. 31, no. 2, pp. 813-814, Jun. 2016
The key role of protodeauration in the gold-catalyzed reaction of 1,3-diynes with pyrrole and indole to form complex heterocycles
Full text linkIndole is a very common structural motif in alkaloids, and a number of them feature remarkable bioactive properties. Due to its relevant role in medicinal chemistry and the pharma-industry, many methods for indole synthesis have been developed, but only a few of them exploit the [4 + 2] approach. Recently a successful attempt at indole and carbazole formation via a formal gold mediated [4 + 2] addition of a diyne to pyrrole and indole rings has been reported by Ohno. A number of intriguing features observed in this reaction are however left to be resolved. We study here the mechanism of the Au-catalyzed reaction of 1,3-diynes with pyrrole and indole rings leading to substituted indoles and carbazoles, respectively. The reaction pathways are found to be significantly more complex than we had anticipated, for instance, in the case of the formation of carbazoles, one competitive route involves the formation of an unexpected spirane intermediate that evolves via a 1,2-alkenyl migration. Beyond this complexity, the current study also serves to highlight the importance of fundamental steps that are often disregarded as kinetically irrelevant, such as the protodeauration of reaction intermediates.Ministerio de Ciencia e Innovación | Ref. CTQ2016-75023-C2-2-PXunta de Galicia | Ref. ED431E 2018/0