Oil price and economic growth : a long story?

Este trabajo analiza los cambios en la relación entre el precio del petróleo y el PIB de Estados Unidos desde una perspectiva de largo plazo. Aunque en ninguna de las dos series (tasas de crecimiento del PIB y del precio del petróleo) se detectan cambios estructurales en la media, se identifican diferentes períodos de volatilidad en cada una de ellas por separado. Adoptando un enfoque multivariante, no se observa un efecto significativo entre los cambios en el precio del petróleo y el crecimiento del PIB cuando se considera el período completo. Sin embargo, a través de un análisis rolling y aplicando un test para la detección de cambios estructurales en un marco multivariante, se identifica una relación significativa entre ambas variables en algunos subperíodos. Por último, se obtiene evidencia, por medio de un modelo VAR time-varying, de que el impacto de los shocks en el precio del petróleo sobre el crecimiento del PIB ha disminuido a lo largo del tiempo. Asimismo, se observa que el efecto negativo sobre el PIB es mayor cuando se producen fuertes incrementos en el precio del petróleo, lo que apoya la evidencia empírica previa de no linealidad en la relación entre ambas variablesThis study investigates changes in the relationship between oil prices and the US economy from a long-term perspective. Although neither of the two series (oil price and GDP growth rates) presents structural breaks in mean, we identify different volatility periods in both of them, separately. From a multivariate perspective, we do not observe a significant effect between changes in oil prices and GDP growth when considering the full period. However, we find a signifi cant relationship in some subperiods by carrying out a rolling analysis and by investigating the presence of structural breaks in the multivariate framework. Finally, we obtain evidence, by means of a time-varying VAR, that the impact of the oil price shock on GDP growth has declined over time. We also observe that the negative effect is greater at the time of large oil price increases, supporting previous evidence of nonlinearity in the relationshi

Trace analysis of flubendiamide in bee pollen using enhanced matrix removal-lipid sorbent clean-up and liquid chromatography-electrospray ionization mass spectrometry

Producción CientíficaIn this work, a new method has been proposed with the aim of determining flubendiamide, a recently commercialized insecticide, in bee pollen by using liquid chromatography coupled to electrospray ionization mass spectrometry. For this purpose, a novel sample treatment has been proposed that has proven efficient in terms of recovery (average analyte recoveries were between 90% and 102%) and absence of matrix effect, and one which is effective, fast and selective. This involved a solvent extraction using an acetonitrile and water mixture, and a clean-up stage where, in addition to freezing, an enhanced matrix removal-lipid sorbent was successfully used for the first time with this matrix and analyte. The chromatographic conditions were also optimized, by selecting a C18 based column (Gemini® C18) and acetic acid (1 mM) in water and methanol as mobile phase components, allowing elution of flubendiamide in<4 min, with a total analysis time of 14 min. Validation was carried out, with the result that all the parameters studied complied with existing European legislation. It should be noted that the sensitivity of the method was excellent, with a quantification limit (4 μg/kg) well below the maximum residue level established for this insecticide in bee products (50 μg/kg). Finally, several bee pollen samples were analyzed, and flubendiamide residues were not found in any of the cases.Este trabajo forma parte de los proyectos de investigación financiados por el Ministerio de Economía y Competitividad e INIA-FEDER (RTA2013-00042-C10-03 y 06)

Supercritical fluid chromatography coupled to mass spectrometry: A valuable tool in food analysis

Producción CientíficaSupercritical fluid chromatography (SFC), although known for several decades, has undergone a growing interest in the last few years fueled by the introduction of modern instruments with improved robustness, and hyphenation to mass spectrometry (MS). This allows the analysis of trace compounds in complex samples with high selectivity, high sensitivity and in a short time, which has contributed to its increased use in the food analysis area. This work reviews the principal applications of SFC-MS in food analysis, highlighting the most important achievements

Development and validation of a new method for the simultaneous determination of spinetoram J and L in honey from different botanical origins employing solid-phase extraction with a polymeric sorbent and liquid chromatography coupled to quadrupole time-of-flight mass spectrometry

Producción CientíficaThe objective of this study was to propose a novel method to determine residues of the bio-insecticide spinetoram, which is a mixture of two components (spinetoram J and L), in honey from multifloral, rosemary and heather botanical origins; liquid chromatography coupled to quadrupole time-of-flight mass spectrometry was the technique employed. An efficient sample treatment (recoveries between 82% and 95%) involving a solid phase extraction with a polymeric sorbent has been recommended, and no matrix effect was observed. Chromatographic analysis (4 min) was performed in reverse phase mode by using a fused-core column (Kinetex® EVO C18) with acetonitrile and ammonium formate as the mobile phase components, which was applied in isocratic elution mode. Method was validated according to the current European legislation. Not only was it selective, but it also displayed a wide linear range, good precision (relative standard deviation values lower than 9%) and sensitivity (low limits of detection (spinetoram J, 0.1–0.3 μg/kg; spinetoram L, 0.1–0.2 μg/kg) and quantification (spinetoram J, 0.3–1.2 μg/kg; spinetoram L, 0.4–0.7 μg/kg). Several honey samples were analyzed with this method and no spinetoram residues were found above the limits of detection.Este trabajo forma parte de los proyectos de investigación financiados por el Ministerio de Economía y Competitividad e INIA-FEDER (RTA2013-00042-C10-03 y 06

Anodic ZnO-Graphene Composite Materials in Lithium Batteries

An important area to cope with in the implementation of technologies for the generation of energy from renewable sources is storage, so it is a priority to develop new ways of storing energy with high efficiency and storage capacity. Experimental reports focused on ZnO-graphene composite materials applied to the anode design which indicated that they show low efficiencies of around 50 %, but values very close to the theoretical capacity have already been reported in recent years. The low efficiency of the materials for the anode design of the Li-ion battery is mainly attributed to the pulverization and fragmentation of the material or materials, caused by the volumetric changes and stability problems during the charge/discharge cycles. In this chapter, we will discuss the development of composite materials such as ZnO-graphene in its application for the design of the anode in the Li-ion battery

Monitoreo de un bosque subandino en proceso de restauración en el Parque Nacional Natural Munchique

The Munchique National Natural Park conserves strategic ecosystems that have been altered by anthropogenic factors; therefore, a passive ecological restoration strategy is implemented as an alternative to recover plant cover and protect biodiversity. The monitoring was carried out in a sub-Andean forest through 20 Gentry-type transects in two processes called advanced restoration and early restoration, only for the years 2013, 2015 and 2017, for reasons of public order. Individuals with DBH ≥ 1 cm were censored. The richness in advanced restoration was 35/2013, 39/2015 and 45/2017 species, while in early restoration a richness of 31/2013, 44/2015 and 45/2017 was recorded. In the three sampling periods and for both processes, the families Rubiaceae and Melastomataceae were the most frequent. Advanced restoration presented a marked dominance of Miconia theizans with 98%/2013, 83%/2015 and 65%/2017 for the importance value (IVI) and in early restoration the most important species was Meriana speciosa with 38%/2013 , 50%/2015 and 55%/2017. Long-term monitoring in both restoration scenarios revealed a slow but effective recovery for increased diversity and improved plant structure.El Parque Nacional Natural Munchique conserva ecosistemas estratégicos de Selva Inferior, Subandina y Andina, que han sido alterados por factores antrópicos; por ello, implementa una estrategia de restauración ecológica pasiva como alternativa para recuperar cobertura vegetal y proteger la biodiversidad. El monitoreo se realizó en un bosque subandino con 20 transectos tipo Gentry en dos procesos denominados restauración avanzada y restauración temprana, solo para los años 2013, 2015 y 2017, debido al orden público. Se censaron los individuos con DAP ≥ 1 cm. La riqueza en restauración avanzada fue de 35/2013, 39/2015 y 45/2017 especies mientras que en restauración temprana se registró una riqueza de 31/2013, 44/2015 y 45/2017. En los tres periodos de muestreo y para ambos procesos, las familias Rubiaceae y Melastomataceae fueron las más frecuentes. Restauración avanzada presentó una marcada dominancia de Miconia theizans con el 98 %/2013, 83 %/2015 y 65 %/2017 para el valor de importancia (IVI) y en restauración temprana la especie más importante fue Meriana speciosa con el 38 %/2013, 50 %/2015 y 55 %/2017. El monitoreo a largo plazo en ambos escenarios de restauración permitió evidenciar una recuperación lenta, pero efectiva para el aumento en diversidad y mejoramiento de la estructura vegetal

Aves frugívoras de un bosque subandino en proceso de restauración del Parque Nacional Natural Munchique

The fragmentation of the sub-Andean Forest is worrying, both for its intrinsic value and for the ecosystem services it provides. Passive restoration is presented as an option to counteract this situation. This research presents information on the variation in the richness of the frugivorous bird community in relation to the natural regeneration time of the forest for the biennial periods I (2012-2013), II (2014-2015) and III (2016-2017). Bird records were made at six observation points for each of the defined scenarios (early restoration, advanced restoration, and paddock), of the PNN Munchique, department of Cauca. In total, 50 species of frugivorous birds from 15 families were recorded, where the Thraupidae family represented 44% of the richness of the bird community. Of the total species, 43 were small frugivores and seven were medium and large frugivores. The richest period was III with 36 species and the lowest was I with 15. After several years of natural succession, there is evidence of a temporary increase in the richness of small frugivorous bird species, with the minority incorporation of some medium and large frugivorous species towards the end of the observation period.La fragmentación del bosque subandino es preocupante, tanto por su valor intrínseco, como por los servicios ecosistémicos que provee. La restauración pasiva se presenta como una opción para contrarrestar esa situación. Esta investigación presenta información sobre la variación en la riqueza de la comunidad de aves frugívoras con relación al tiempo de regeneración natural del bosque para los periodos bianuales I (2012-2013), II (2014-2015) y III (2016-2017). Los registros de las aves se realizaron en seis puntos de observación para cada uno de los escenarios definidos (restauración temprana, avanzada y potrero), del PNN Munchique, departamento del Cauca. En total se registraron 50 especies de aves frugívoras de 15 familias, donde la familia Thraupidae representó el 44% de la riqueza de la comunidad de aves. Del total de especies, 43 eran frugívoros pequeños y siete de frugívoros medianos y grandes. El periodo con mayor riqueza fue el III con 36 especies y el menor fue el I con 15. Tras varios años de sucesión natural, se evidencia el aumento temporal en la riqueza de especies de aves frugívoras de pequeño tamaño, con la incorporación minoritaria de algunas especies de frugívoras medianas y grandes hacia el final del periodo de observación.     

Confectio Gari Pompeiani. Experimental procedure for the preparation of Roman fish sauces

El presente trabajo hace públicos por primera vez los resultados de un proceso experimental fruto de la colaboración entre las universidades de Cádiz y Sevilla. Dicho proceso, en el que han participado arqueólogos y bioquímicos, se ha realizado en el Departamento de Ingeniería Química de la Facultad de Ciencias de la Universidad de Cádiz y ha consistido en la identificación de la naturaleza concreta y en la reproducción física de la afamada salsa salada de pescado greco-romana denominada garum (liquamen), de un subproducto alimenticio sólido de esta (hallec) y de una salsa secundaria y de menor calidad denominada en latín muria. El estudio filológico de antiguas recetas de confección del garum (confectio gari) y los resultados analíticos de los residuos de estos productos recogidos durante la excavación de la denominada bottega o tienda del garum de Pompeya han permitido simular su producción artesanal en laboratorio y obtener unos condimentos salados cuyo aspecto físico y características alimentarias coinciden con los descritos por las fuentes literarias grecorromanas y con los que aún muestran los residuos orgánicos analizados de estas producciones.The present work publishes for the first time the results of an experimental process carried out in cooperation between the Universities of Cádiz and Seville. This process, involving the participation of archaeologists and experts in biochemistry, has been effected in the chemical engineering department of the University of Cádiz and has focused on the characterization and reproduction of the famous Graeco- Roman salted fish sauce known as garum (liquamen), of a solid by-product of this sauce (hallec) and of a secondary, lesser quality, sauce known in Latin as muria. The philological analysis of ancient recipes (confectio gari) and the analysis of the residues collected in the so-called bottega or Garum Shop, in Pompeii, have permitted their artisanal reproduction in the laboratory. The physical aspect and alimentary features of these products coincide with those described in the ancient sources and with the organic residues under analysis.España. Ministerio de Economía y Competitividad 15733España. Ministerio de Economía y Competitividad HAR2011- 28244España. Ministerio de Economía y Competitividad HAR2013-43599Fondo Europeo de Desarrollo Regional (FEDER) 15733Fondo Europeo de Desarrollo Regional (FEDER) HAR2011- 28244Fondo Europeo de Desarrollo Regional (FEDER) HAR2013-43599Instituto del Patrimonio Cultural de Españ

Baropodometric association of the first metatarsal bone in medial tibial stress syndrome

[Resumen] Objetivos: El síndrome de estrés tibial medial (SETM) es una lesión de sobreuso por estrés mecánico, que se localiza por lo general en el borde postero-medial de la tibia. El objetivo de este estudio es cuantificar la diferencia baropodométrica existente en la primera cabeza metatarsal entre dos grupos. Métodos: Se analizaron las huellas de 30 participantes, de los cuales 15 padecían SETM y 15 controles. Se trata de un estudio observacional en el que se obtuvieron las huellas baropodométricas de los participantes, caminando sobre una plataforma de presiones. Se cuantificó la presión plantar media y la integral presión/tiempo que estaba recibiendo cada paciente en la primera cabeza metatarsal. Realizamos la prueba t-student para muestras independientes con el objetivo de definir las diferencias. Resultados: Los resultados de la variable presión plantar media muestran diferencias estadísticamente significativas entre los 2 grupos (p=0,001 para pie izquierdo y p=0,001 para pie derecho). Por el contrario no se observaron diferencias estadísticamente significativas para la variable integral presión/tiempo en ambos grupos (p=0,327 para pie izquierdo y p=0,300 para pie derecho). Conclusiones: Según nuestro estudio, los resultados obtenidos concluyen que el SETM se ocasiona con mayor frecuencia en personas con una disminución significativa de la presión plantar en la cabeza del primer metatarsiano medida en plataforma baropodométrica. Consideramos que son necesarios más estudios que evidencien esta relación biomecánica mediante plantillas instrument[Abstract] Objectives: Medial tibial stress syndrome (MTSS) is a mechanical stress overuse lesion, which is usually located at the post-medial border of the tibia. This study aims to quantify the baropodometric difference in the first metatarsal head between two groups. Methods: For the study 30 patient footprints were analyzed. Among them, half were affected by MTSS and the other half were controls. The baropodometric footprint samples were obtained by walking barefooted over a platform. While the patients were walking the average plantar pressure and the integral ratio pressure/time was quantified. The T-student test was performed in independent samples in order to define the differences. Results: The average plantar pressure results show statistically significant differences amongst the 2 groups (p=0.001 for the left foot and p=0.001 for the right foot). On the other hand, there were not any significant differences for the integral pressure/time variable in both groups (p=0.327 for the left foot and p=0.300 for the right foot). Conclusion: By having done this study, we can affirm that the MTSS is more frequent in persons with a significant plantar pressure decrease in the first metatarsal head measured in the baropodometric platform. We consider the need for further studies that prove this biomechanical connection through instrumented insoles

Morphological Description of Frontal EEG Interictal and Ictal Discharges in an Adult Cohort of 175 Patients

EEG morphology; Electroencephalography; Frontal lobe seizuresMorfología EEG; Electroencefalografía; Convulsiones del lóbulo frontalMorfologia EEG; Electroencefalografia; Convulsions del lòbul frontalClinical and electroencephalogram (EEG) features in frontal lobe epilepsy (FLE) vary considerably among patients, making the diagnosis a challenge. The objective of this study was to describe interictal and ictal EEG activity, identifying variables that could help to differentiate and diagnose frontal lobe epilepsy cases. A prospective cross-sectional study from patients with frontal interictal epileptiform discharges (IED) referred to the Vall d’Hebron University Hospital (Barcelona, Spain) after a clinical event compatible with epileptic seizures was designed. The interictal and ictal activity were analyzed to provide a detailed EEG description of the cases, using different statistical analyses. The morphological seizure pattern at the ictal onset remained globally unchanged over time in seizures arising from the frontal lobe for each patient. Isolated sharp waves were the most frequent waveforms in the expression of IED. Frontal lobe seizures are frequently short and sometimes appear grouped in clusters within the same recording. Often the ictal expression of the electrical activity in frontal lobe seizure is subtle and challenging to interpret. A description of the main findings is summarized to identify seizures arising from the frontal lobe and avoid false negatives findings in EEG interpretations.This research received no external funding