Is the leadership of the Brent-WTI threatened by China's new crude oil futures market?

The recent listing of a new crude oil futures contract on the Shanghai International Energy Exchange (INE) has reopened the debate over whether crude oil produced in different countries or locations constitutes a unified world oil market. The aim of this paper is to study the information flows among Brent, West Texas Intermediate (WTI) and the new Medium Sour Crude Oil (SC) futures contract listed on INE futures markets to assess whether the trading of this new futures contract has altered the dominant role of the most traded oil benchmarks in the world. A multiple regression model identifies the Brent futures market as the most influential market in the oil price discovery process, while WTI appears to be the most sensitive. Furthermore, we have observed that SC does not influence any market and it is only sensitive to Brent news, even though WTI is the most heavily traded futures contract. Therefore, the launch of the SC futures contract has not yet altered the dominant role of Brent over WTI

Numerical evaluation of the Green's functions for arbitrarily shaped cylindrical enclosures and their optimization by a new spatial images method

IIn this paper, a spatial image technique is used to efficiently calculate the mixed potential Green’s functions associated with electric sources, when they are placed inside arbitrarily shaped cylindrical cavities. The technique is based on placing electric dipole images and charges outside the cavity region. Their strength and orientation are thencalculated by imposing the appropriate boundary conditions for the fields at discrete points on the metallic wall. A method for the assessment of the potentials accuracy is proposed, and several optimization techniques are presented. Three cavities are analyzed to demonstrate the usefulness of the techniques. The cutoff frequencies and potentials patterns are compared to those obtained by a standard finite elements technique, showing excellent agreement. Finally, a band-pass filter based on coupled lines is analyzed, demonstrating the practical value of the technique.This work has been developed with support from the Spanish National Project (CICYT) with reference TEC2004-04313-C02-02/TCM, and the Regional Seneca Project with reference 02972/PI/0

La fragilidad en el anciano con enfermedad renal crónica

ResumenEn los últimos años el concepto de fragilidad como «estado de prediscapacidad» se ha extendido de forma amplia en todos los que trabajamos en beneficio de la persona mayor. Su importancia radica no solo en su elevada prevalencia —superior al 25% en mayores de 85 años—, sino a que es considerada un factor de riesgo independiente, que confiere a los ancianos que lo presentan un riesgo elevado de discapacidad, institucionalización y mortalidad.El estudio de la función renal es relevante en pacientes que soportan gran carga de comorbilidad, habiéndose encontrado una importante asociación entre la enfermedad renal crónica y el desarrollo de eventos clínicos adversos como la enfermedad cardiovascular, la insuficiencia cardiaca, la enfermedad renal terminal, el incremento de la susceptibilidad a infecciones y el mayor deterioro funcional.La fragilidad puede ser una situación reversible, por lo que su estudio en el paciente con enfermedad renal crónica es de especial interés. Este artículo tiene por objeto describir las interrelaciones existentes entre envejecimiento, fragilidad y enfermedad renal crónica a la luz de la bibliografía pertinente más relevante y reciente publicada.AbstractIn recent years, the concept of frailty as a “state of pre-disability” has been widely accepted by those involved in the care of the elderly. Its importance lies not only in its high prevalence - more than 25% in people over 85 years of age - but it is also considered an independent risk factor of disability, institutionalisation and mortality amongst the elderly.The study of renal function is relevant in patients with major comorbidities. Studies have shown a significant association between chronic kidney disease and the development of adverse clinical outcomes such as heart disease, heart failure, end-stage renal disease, increased susceptibility to infections and greater functional impairment.Frailty can be reversed, which is why a study of frailty in patients with chronic kidney disease is of particular interest. This article aims to describe the association between ageing, frailty and chronic kidney disease in light of the most recent and relevant scientific publications

Application of the high-gain substrate-superstrate configuration to dielectric leaky-wave antennas

The high-gain substrate-superstrate configuration, which was proposed to increase the gain in printed circuit antennas, is applied to dielectric leaky-wave antennas (LWAs) to improve its frequency response. Analysis of a slitted suspended dielectric rectangular waveguide is carried out using a full-wave method. It is proved that the minimum values of the leakage constant of the leaky-wave mode for the suspended configuration are related to the high-gain resonance conditions. Moreover, it is found that the suspended LWA exhibits very small beamwidth variations in a large frequency bandwidth. It is well-known that inhomogeneous filled LWAs suffer from variation of beamwidth as the angle of maximum radiation is scanned with frequency. The proposed topology can be adjusted so that a flat response of the beamwidth can be obtained in a large frequency band, while maintaining the frequency-scanning behavior of the LWA.This work was supported by Spanish National Projects ESP2001-4546-PE and TIC2000-0591- C03-03, by Regional Seneca Projects 2002 PB/4/FS/02 and PMPDI-UPCT- 2004, and by the EPSON-Ibérica Foundation

The inconvenience yield of carbon futures

Since 2009, the European Carbon Futures Market has been in a permanent contango situation that is characterised by systematic negative convenience yields that allow investors to exploit profitable arbitrage opportunities. The objective of this paper is to analyse the possible drivers of these negative convenience yields. Our empirical results indicate that although some carbon trading variables are behind this contango situation, the carbon inconvenience yield is better explained if other financial markets and variables are considered, suggesting a financialization of the European Carbon Futures Market

Acoustic assessment and distribution of the main pelagic fish species in ICES Subdivision 9a South during the ECOCADIZ-RECLUTAS 2018-10 Spanish survey (October 2017).

The present working document summarises the main results obtained during the ECOCADIZ-RECLUTAS 2018-10 Spanish (pelagic ecosystem-) acoustic survey. The survey was conducted by IEO between 10th and 29th October 2018 in the Portuguese and Spanish shelf waters (20-200 m isobaths) off the Gulf of Cadiz onboard the R/V Ramón Margalef. The survey’s main objective is the acoustic assessment of anchovy and sardine juveniles (age 0 fish) in the recruitment areas of the Gulf of Cadiz. The 21 foreseen acoustic transects were sampled. A total of 25 valid fishing hauls were carried out for echo-trace ground-truthing purposes. Chub mackerel was the most frequent species in those hauls, followed by sardine, anchovy, horse mackerel, mackerel, bogue and Mediterranean horse mackerel. Acoustic sampling was carried out with the recently installed Simrad™ EK80 echo-sounder working in multi-frequency and in CW mode. A misconfiguration of the range of the acoustic active layer entailed to slow down the ping rate (1.5-2.0 seconds) in relation to the standard values (at about 0.3 seconds), resulting an acoustic sampling rate much lower than it should be. Therefore, the results from this acoustic sampling and the resulting estimates from this survey should be considered with caution. Anchovy abundance and biomass were of 953 million fish and 10 493 t. The abundance and biomass of age-0 anchovies were estimated at 543 million fish and 3 834 t, 57% and 36% of the total population abundance and biomass, respectively. Despite the methodological problems, these estimates seem to suggest a recent decrease in relation to previous years. The estimates for Gulf of Cadiz sardine in the surveyed area were of 1 134 million fish and 20 679 t. Estimates of age-0 sardine were of 1 036 million fish and 15 224 t, 91% and 74% of the total estimated abundance and biomass, respectively. Even taking into account a possible underestimation for the abovementioned methodological problems, the values reached in 2018 were above the historical mean for the total population and recruits abundance and for the recruit biomass, and they might suggest a relatively stable situation since the maxima registered in 2016

Analysis and design of periodic leaky-wave antennas for the millimeter waveband in hybrid waveguide-planar technology

This work presents a full-wave integral equation approach specifically conceived for the analysis and design of laterally-shielded rectangular dielectric waveguides, periodically loaded with planar perturbations of rectangular shape. This type of open periodic waveguide supports the propagation of leaky-wave modes, which can be used to build leaky-wave antennas which exhibit many desirable features for millimeter waveband applications. The particularities of the leaky-mode analysis theory are described in this paper, and comparisons with other methods are presented for validation purposes. Using this leaky-mode analysis method, a novel periodic leaky-wave antenna is presented and designed. This novel antenna shows some important improvements with respect to the features of previously proposed antennas. The results of the designed radiation patterns are validated with three-dimensional electromagnetic analysis using commercial software.This work was supported by Spanish National projects ESP2001-4546-PE and TEC2004-04313-C02-02/TCM and Regional Séneca projects 2002 PB/4/FS/02. The authors would like to thank the EPSON-Ibérica Foundation for its stimulating support. and PMPDI-UPCT-2004. The authors would like to thank the EPSON-Ibérica Foundation for its stimulating support

Novel microwave network for the leaky-wave analysis of evanescent fields in stub-loaded structures

In this paper, a new transverse equivalent network for the modal analysis of stub-loaded leaky-wave antennas is developed. The derived network is useful for the study of the radiation of evanescent fields that occurs when they reach the top aperture of the parallel-plate stub. This transverse network is based, for the first time, on a nonhybrid formulation of the constituent parallel- plates modes of order 1 (TE 1 andTM 1 ). The obtained network is an alternative to the one based on hybrid TE 1 andTM 1 modes, and leads to a simpler transverse resonance equation. The new equivalent network is validated by obtaining leaky-mode dispersion curves for a previously studied leaky-wave antenna in nonradiative dielectric guide technology.This work was supported under the Spanish National Project TEC2004-04313-C02-02/ TCM, under the Regional Seneca Project 02972/PI/05, and under Regional Scholarship PMPDI-UPCT-2007