Multiplicative local linear hazard estimation and best one-sided cross-validation

This paper develops detailed mathematical statistical theory of a new class of cross-validation techniques of local linear kernel hazards and their multiplicative bias corrections. The new class of cross-validation combines principles of local information and recent advances in indirect cross-validation. A few applications of cross-validating multiplicative kernel hazard estimation do exist in the literature. However, detailed mathematical statistical theory and small sample performance are introduced via this paper and further upgraded to our new class of best one-sided cross-validation. Best one-sided cross-validation turns out to have excellent performance in its practical illustrations, in its small sample performance and in its mathematical statistical theoretical performance

Ensayo de arcillas modificadas con materia orgánica soluble para la eliminación de Cu y Zn

La contaminación por metales pesados es un tema de gran preocupación. Entre las diversas actividades que contribuyen a aumentar la presencia de metales pesados en el medio ambiente, se encuentra la agricultura. Por ejemplo, el uso de fertilizantes de tipo fosforados y algunos fungicidas incrementan la aparición Cu y Zn en aguas de zonas agrícolas e incluso residuales de la industria agroalimentaria. La eliminación de metales pesados mediante el uso de minerales de la arcilla tipo montmorillonita ha sido objeto de numerosos trabajos (Barbier et al., 2000) dada su alta capacidad de adsorción principalmente asociada a su capacidad de intercambio catiónico (CIC), fácil accesibilidad de su interlámina y a la presencia de grupos hidroxilos de los bordes de ruptura de la capa octaédrica.Este trabajo ha sido financiado con los proyectos de la Junta de Andalucía (P11-AGR-7400) y RECUPERA 2020 (MCINN_CSIC). E. Durán agradece la concesión de la Beca Predoctoral FPI asociada (P11-AGR-7400). A Fertiormont y a Spuny Morón por el material suministrado.Peer Reviewe

Assessing the Effect of Organoclays and Biochar on the Fate of Abscisic Acid in Soil

10 páginas.-- 6 figuras.-- 2 tablas.-- 56 referencias.-- The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.jafc.6b03668The potential use of allelopathic and signaling compounds as environmentally friendly agrochemicals is a subject of increasing interest, but the fate of these compounds once they reach the soil environment is poorly understood. This work studied how the sorption, persistence, and leaching of the two enantiomers of the phytohormone abscisic acid (ABA) in agricultural soil was affected by the amendments of two organoclays (SA-HDTMA and Cloi10) and a biochar derived from apple wood (BC). In conventional 24-h batch sorption experiments, higher affinity toward ABA enantiomers was displayed by SA-HDTMA followed by Cloi10 and then BC. Desorption could be ascertained only in BC, where ABA enantiomers presented difficulties to be desorbed. Dissipation of ABA in the soil was enantioselective with S-ABA being degraded more quickly than R-ABA, and followed the order unamended > Cloi10-amended > BC-amended > SA-HDTMA-amended soil for both enantiomers. Sorption determined during the incubation experiment indicated some loss of sorption capacity with time in organoclay-amended soil and increasing sorption in BC-amended soil, suggesting surface sorption mechanisms for organoclays and slow (potentially pore filling) kinetics in BC-amended soil. The leaching of ABA enantiomers was delayed after amendment of soil to an extent that depended on the amendment sorption capacity, and it was almost completely suppressed by addition of BC due to its irreversible sorption. Organoclays and BC affected differently the final behavior and enantioselectivity of ABA in soil as a consequence of dissimilar sorption capacities and alterations in sorption with time, which will affect the plant and microbial availability of endogenous and exogenous ABA in the rhizosphere.This work has been financed by the Spanish Ministry of Economy and Competitiveness (MINECO Project AGL2014- 51897-R), EU FACCE-JPI (Designchar4food Project), and Junta de Andalucıa (P011-AGR-7400 and Research Group ́ AGR-264), cofinanced with European FEDER funds. The use of trade, firm, or corporation names in this paper is for the information and convenience of the reader. Such use does not constitute an official endorsement or approval by the U.S. Department of Agriculture, the Agricultural Research Service, or the Instituto de Recursos Naturales y Agrobiologıa de Sevilla ́ (IRNAS-CSIC) of any product or service to the exclusion of others that may be suitablePeer reviewe

Influence of biochar on the enantioselective behavior of the chiral fungicide metalaxyl in soil

Comunicación oral presentada en la EGU General Assembly 2015, held 12-17 April, 2015 in Vienna, Austria. Id.15367Chiral pesticides comprise an emerging and important class of organic pollutants currently, accounting for more than a quarter of used pesticides. Consequently, the contamination problems caused by chiral pesticides are concern matter and factors affecting enantioselective processes of chiral pesticides in soil need to be understood. For example, certain soil management practices, such as the use of organic amendments, can affect the enantioselective behavior of chiral pesticides in soils. Recently, biochar (BC), i.e. organic matter subjected to pyrolysis, has been proposed as organic amendment due to beneficial properties such as its high stability against decay in soil environments and its apparent ability to influence the availability of nutrients. BC is considered to be more biologically inert as compared to otherforms of organic carbon. However, its side-effects on the enantioselectivity of processes affecting the fate of chiral pesticides is unknown. The aim of this study was to assess the effect of biochar (BC) on the enantioselectivity of sorption, degradation, and leaching of the chiral fungicide metalaxyl in an agricultural soil. Amending the soil with BC (2% w/w) resulted in 3 times higher sorption of metalaxyl enantiomers compared to unamended soil, but no enantioselectivity in the process was observed. Moreover, both enantiomers showed some resistance to be desorbed in BC-amended soil compared to unamended soil. Dissipation studies revealed that the degradation of metalaxylwas more enantioselective in the unamended soil than in BC-amended soil. In unamended soil, R-metalaxyl(biologically active) and S- metalaxyl had half-lives (t1/2) of 3 and 34 days, respectively. BC enhanced the persistence of both enantiomers in the soil, with R-metalaxyl being degraded faster (t1/2=43 days) than S-metalaxyl (t1/2= 100 days). The leaching of both S-and R-metalaxyl was almost suppressed after amending the soil with BC; less than 10% of the fungicide applied to soil columns was recovered in leachates, in contrast to significantly higher percentages leachedin unamended soil, being the process more enantioselective in the latter case. Finally, total recoveries of both enantiomers were greater for BC-amended soil columns than for unamended soil columns, indicating reduced degradation in BC- amended soil. Our findings illustrated the ability of biochar to modify the enantioselectivity behavior of metalaxyl in soil by its high sorption capacity. BC could contribute to reduce the current agronomic doses used for chiral pesticides to deplete the contamination problems associated with their use, and also to act as an immobilizing amendment in soil remediation strategies.MINECO (AGL2011-23779), FACCE-JPI (Designchar4food), JA (AGR-264) and FEDERF-SE (OP 2007-2013).Peer Reviewe

Caracterización mecánica de pistas deportivas fabricadas con materiales procedentes de neumáticos fuera de uso (NFU)

Congreso celebrado en la Escuela de Arquitectura de la Universidad de Sevilla desde el 24 hasta el 26 de junio de 2015.The European Framework Directive 2008/98/EC on waste established as priority reuse and recycling before other recovery alternatives. In this normative reference, one the main waste flows identified are the end-of-life tyres, as a material whose mechanical properties could provide advantage in the construction of new structures. This paper presents the mechanical characterization of a layer made with shredded tires out of use, inside a section of a sportive track which included a sand layer. The use of the shredded tires out of use provides special features related with elasticity and damping to the sportive surface. In order to do that, a new test based on UNE-14809 was designed. A number of tests were performed using different configuration of sand and shredded tires. From the results obtained, a numerical model was implemented in FEA software

Efecto de la adición de organo-hidrotalcita a un suelo agrícola en el comportamiento de los fungicidas tebuconazol y metalaxil bajo condiciones reales de campo

2 páginas.-- 2 tablas.-- 2 referencias.-- Poster presentado en XXIV Reunión de la Sociedad Española de Arcillas Sevilla. Libro de Resúmenes: Noviembre de 2015 en Sevilla.Existen numerosos trabajos que abordan las aplicaciones de arcillas naturales, inalteradas o modificadas, como adsorbentes de pesticidas para la depuración de aguas e incluso para actuar como soportes en formulaciones de liberación lenta del pesticida o como barreras inmovilizantes en suelos (Cornejo et al., 2008). La mayoría de estos estudios se han realizado bajo condiciones controladas en el laboratorio y usando minerales de la arcilla naturales del grupo de las esmectitas. En los últimos años, ha aumentado el interés por explotar las propiedades adsorbentes de los hidróxidos dobles laminares (HDLs), también conocidos como hidrotalcitas (HTs) o arcillas aniónicas, cuyas características estructurales guardan cierta relación con las de las esmectitas (Cornejo et al., 2008). Los LDHs consisten en láminas del tipo brucita de un metal divalente con sustituciones isomórficas que proporcionan a las láminas una carga permanente positiva y que es compensada con aniones intercambiables que se sitúan en el espacio interlaminar. Aunque los resultados obtenidos hasta ahora ponen de manifiesto la elevada capacidad de adsorción de los LDHs para muchos pesticidas y la versatilidad que les confiere la posibilidad de modificarlos mediante la intercalación de aniones orgánicos en el espacio interlaminar (Celis et al., 2014), su utilidad como enmendantes para aumentar la capacidad de adsorción de los suelos bajo condiciones ambientales reales aún no ha sido evaluada.Este trabajo ha sido financiado por el Ministerio de Economía y Competitividad (MINECO) a través de los proyectos AGL2011-23779 y AGL2014-51897-R y por la Junta de Andalucía a través del Grupo de Investigación AGR-264, con parte de fondos FEDER-FSE. R. López-Cabeza agradece al MINECO la concesión de una beca pre-doctoral de FPI asociada al proyecto AGL2011-23779.Peer reviewe

Effect of synthetic clay and biochar addition on dissipation and enantioselectivity of tebuconazole and metalaxyl in an agricultural soil: Laboratory and field experiments

10 páginas.-- 4 figuras.-- 3 tablas.-- referencias.-- Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.agee.2016.05.017Laboratory and field experiments were conducted to assess how the addition of oleate-modified hydrotalcite (clay) and biochar (BC) to an agricultural soil affected the sorption, leaching, persistence, and enantiomeric composition of soil residues of two chiral fungicides, tebuconazole and metalaxyl. Laboratory experiments showed that the sorption of both fungicides ranked as follows: unamended soil < BC-amended soil < clay-amended soil. The addition of clay at a rate of 1% increased metalaxyl soil sorption coefficient (Kd) from 0.34 to 3.14 L kg−1 and that of tebuconazole from 2.4 to 47.4 L kg−1. In our experimental set-up, field plots were either unamended or amended with clay (2 t ha−1) or BC (4 t ha−1), and subsequently treated with a mixture of tebuconazole and metalaxyl at 3 and 6 kg ha−1, respectively. The leaching, persistence, and enantiomer composition of fungicides residues were monitored by sampling at different soil depths (0–5, 5–10, 10–20 cm) for 98 days. No significant changes in the scarce mobility and long persistence of tebuconazole upon amending the soil with clay or BC were observed. In contrast, sorption to clay and BC particles reduced the leaching and degradation of metalaxyl and the clay increased its persistence in the topsoil compared to the unamended soil. The enantioselective analysis of tebuconazole and metalaxyl soil residues indicated that tebuconazole remained mostly racemic along the experiment, whereas for metalaxyl the concentration of S-enantiomer was greater than the concentration of R-enantiomer, more so at longer experimental times and deeper horizons. Nevertheless, for the top 0–5 cm soil layer metalaxyl remained more racemic in clay- and BC-amended soil than in unamended soil. Our results show that addition of amendments with high sorptive capacities can be beneficial in reducing leaching and degradation losses of chiral pesticide enantiomers from the topsoil, and that sorption by the amendments can influence the final enantiomeric composition of pesticide residues.This work was financed by the Spanish Ministry of Economy and Competitiveness (MINECO Projects AGL2011-23779, AGL2013-48446-C3-1-R and AGL2014-51897-R) and Junta de Andalucía (JA Research Group AGR-264), with FEDER-FSE funds. R. López-Cabeza thanks MINECO for a pre-doctoral fellowship linked to the Project AGL2011-23779 (Grant BES-2012-059945). The authors also thank P. Franco (Chiral Technologies Europe) and I. Girón (IRNAS) for their technical assistancePeer reviewe

Four-point functions and kaon decays in a minimal AdS/QCD model

We study the predictions of holographic QCD for various observable four-point quark flavour current-current correlators. The dual 5-dimensional bulk theory we consider is a $SU(3)_L \times SU(3)_R$ Yang Mills theory in a slice of $AdS_5$ spacetime with boundaries. Particular UV and IR boundary conditions encode the spontaneous breaking of the dual 4D global chiral symmetry down to the $SU(3)_V$ subgroup. We explain in detail how to calculate the 4D four-point quark flavour current-current correlators using the 5D holographic theory, including interactions. We use these results to investigate predictions of holographic QCD for the $\Delta I = 1/2$ rule for kaon decays and the $B_K$ parameter. The results agree well in comparison with experimental data, with an accuracy of 25% or better. The holographic theory automatically includes the contributions of the meson resonances to the four-point correlators. The correlators agree well in the low-momentum and high-momentum limit, in comparison with chiral perturbation theory and perturbative QCD results, respectively.Comment: Published version, title changed to conform with Journal format, references and clarifying remarks added, 40 pages, 5 figure

Performance of magnetic dipole contribution on ferromagnetic non-Newtonian radiative MHD blood flow: An application of biotechnology and medical sciences

Casson flow ferromagnetic liquid blood flow over stretching region is studied numerically. The domain is influence by radiation and blood flow velocity and thermal slip conditions. Blood acts an impenetrable magneto-dynamic liquid yields governing equations. The conservative governing nonlinear partial differential equations, reduced to ODEs by the help of similarity translation technique. The transport equations were transformed into first order ODEs and the resultant system are solved with help of 4th order R-K scheme. Performing a magnetic dipole with a Casson flow across a stretched region with Brownian motion and Thermophoresis is novelty of the problem. Significant applications of the study in some spheres are metallurgy, extrusion of polymers, production in papers and rubber manufactured sheets. Electronics, analytical instruments, medicine, friction reduction, angular momentum shift, heat transmission, etc. are only few of the many uses for ferromagnetic fluids. As ferromagnetic interaction parameter value improves, the skin-friction, Sherwood and Nusselt numbers depreciates. A comparative study of the present numerical scheme for specific situations reveals a splendid correlation with earlier published work. A change in blood flow velocity magnitude has been noted due to Casson parameter. Increasing change in blood flow temperature noted due to Casson parameter. Skin-friction strengthened and Nusselt number is declined with Casson parameter. The limitation of current work is a non-invasive magnetic blood flow collection system using commercially available magnetic sensors instead of SQUID or electrodes.Unai Fernandez-Gamiz was supported by Government of the Basque Country [ELKARTEK21/10KK-2021/00014 & ELKARTEK22/85]. Irfan Nurhidayat was supported by King Mongkut’s Institute of Technology Ladkrabang (KMITL), Bangkok, Thailand [KDS2020/045]