Design rules for antenna placement on MIMO systems

In recent works, it is demonstrated that, depending on the different spatial distributions and distance between elements, there exists a different true polarization diversity (TPD) configuration that provides a high improvement in terms of capacity. This means that it is necessary to choose the appropriate TPD configuration to maximize the multiple-input-multiple-output (MIMO) capacity. In this work, a genetic algorithm is used to optimize the element positions for four new different configurations in combination with the TPD technique. It is shown that, for some configurations, the same polarization option is always found to reach the maximum capacity. Based on this, some novel design rules are provided to maximize MIMO capacity when the area for placing the antennas is very small. This is the case for most of the wireless devices, where the antenna design and location is one of the latest design constraints to be taken into consideration in the device design

Elisidepsin interacts directly with glycosylceramides in the plasma membrane of tumor cells to induce necrotic cell death

This is an open access article distributed under the terms of the Creative Commons Attribution License.-- et al.Plasma membrane integrity is essential for cell life. Any major break on it immediately induces the death of the affected cell. Different molecules were described as disrupting this cell structure and thus showing antitumor activity. We have previously defined that elisidepsin (Irvalec®, PM02734) inserts and self-organizes in the plasma membrane of tumor cells, inducing a rapid loss of membrane integrity, cell permeabilization and necrotic death. Here we show that, in sensitive HCT-116 colorectal cells, all these effects are consequence of the interaction of elisidepsin with glycosylceramides in the cell membrane. Of note, an elisidepsin-resistant subline (HCT-116-Irv) presented reduced levels of glycosylceramides and no accumulation of elisidepsin in the plasma membrane. Consequently, drug treatment did not induce the characteristic necrotic cell death. Furthermore, GM95, a mutant derivative from B16 mouse melanoma cells lacking ceramide glucosyltransferase (UGCG) activity and thus the synthesis of glycosylceramides, was also resistant to elisidepsin. Over-expression of UGCG gene in these deficient cells restored glycosylceramides synthesis, rendering them sensitive to elisidepsin, at a similar level than parental B16 cells. These results indicate that glycosylceramides act as membrane targets of elisidepsin, facilitating its insertion in the plasma membrane and the subsequent membrane permeabilization that leads to drug-induced cell death. They also indicate that cell membrane lipids are a plausible target for antineoplastic therapy.Funding: The work of CV, AM and CM was partially supported by Ministerio de Economía y Competitividad (www.mineco.gob.es) [grant numbers SAF2010-14916 and SAF2013-45800-R], and Instituto de Salud Carlos III (www.isciii.es) [grant numbers FIS-RECAVA RD06/0014/0025 and FIS-RIC RD12/0042/0019]. The work of MPL and CG was partially supported by Ministerio de Economía y Competitividad [grant number CTQ 2010-1645]. CM and AM hold FPI and JAE-Predoc (www.csic.es) fellowships, respectively.Peer Reviewe

Circularly polarised broadband planar lightweight reflectarray with eligible pattern for satellite communications in Ku-Band

This study presents a lightweight planar patch-array reflectarray at Ku-band for satellite communications. The reflectarray is composed of two separate planar structures: the radiating interface formed by a planar multi-layered broadband patch array, and a phase shifting device formed by 3 dB/90° couplers. The radiating element is a multi-layered patch structure, designed to provide circular polarisation (CP). Each array cell phase is controlled by open-ended shifting lines of variable length connected to the 3 dB/90° couplers. The use of this kind of couplers maintains the same CP received/transmitted: the design imposes that if a right-hand CP (RHCP) [or left-hand CP (LHCP)] is received coming from the feeder, the same RHCP (or LHCP) configuration is re-radiated by the reflectarray. Additionally, the feeding horn can be moved in the x or y axes, so that the feeder angular position let re-define the radiation pattern and its pointing direction. Finally, measurements of a lightweight portable planar reflectarray prototype are provided and very good agreement is observed when compared with theoretical result

Broadband electronically tunable reflectionbased phase shifter for active-steering microwave reflectarray systems in Ku-band

This document provides the design of an electronically reconfigurable microwave phase shifter for reflectarray systems. The phase shifter is based on a hybrid coupler with reflective circuits in three ports. Each reflective circuit introduces a phase variation that can be modified due to the variable capacity value of a varactor inserted in it. The phase shifting process includes three different stages of phase shifting for the incoming signal in its way through the phase shifter: the signal is conducted through the device towards the reflective circuits in four different ways. The input port of the device is also the output one, providing the desired reflective phase shifting effect. This device is of great interest in reflectarray applications in order to provide more than 360° of controllable phase shifting at each array element. The document includes the complete design of the phase shifter along with its design parameters and circuital behaviour

Electronically reconfigurable reflective phase shifter for circularly polarized reflectarray systems

This letter presents the design of a two-port electronically reconfigurable phase shifter for circularly polarized reflectarray systems at microwave frequencies. The phase shifter is based on 3 dB/90? couplers combined with reflective circuits that introduce sequentially the phase variation. Each reflective circuit, formed by printed elements (L) and tunable varactors, produces the phase variation due to the variable capacity value of the varactor. The phase shifting process includes three different stages of phase shifting for the signal in its way from the input port towards the output port through the phase shifter. Both ports are interchangeable, acting either as input or output ports. This fulfils the reflection requirements of circularly polarized reflectarrays, being especially suitable for this purpose. The complete design, together with its circuital behavior and performance results, are depicted in this document

Modeling photosynthetically active radiation from satellite-derived estimations over mainland Spain

A model based on the known high correlation between photosynthetically active radiation (PAR) and global horizontal irradiance (GHI) was implemented to estimate PAR from GHI measurements in this present study. The model has been developed using satellite-derived GHI and PAR estimations. Both variables can be estimated using Kato bands, provided by Satellite Application Facility on Climate Monitoring (CM-SAF), and its ratio may be used as the variable of interest in order to obtain the model. The study area, which was located in mainland Spain, has been split by cluster analysis into regions with similar behavior, according to this ratio. In each of these regions, a regression model estimating PAR from GHI has been developed. According to the analysis, two regions are distinguished in the study area. These regions belong to the two climates dominating the territory: an Oceanic climate on the northern edge; and a Mediterranean climate with hot summer in the rest of the study area. The models obtained for each region have been checked against the ground measurements, providing correlograms with determination coefficients higher than 0.99This work was supported by the Spanish Ministry of Economy, Industry and Competitiveness (MINECO) [Project CGL2016-79284-P AEI/FEDER/UE]S

Irvalec Inserts into the Plasma Membrane Causing Rapid Loss of Integrity and Necrotic Cell Death in Tumor Cells

Irvalec is a marine-derived antitumor agent currently undergoing phase II clinical trials. In vitro, Irvalec induces a rapid loss of membrane integrity in tumor cells, accompanied of a significant Ca2+ influx, perturbations of membrane conductivity, severe swelling and the formation of giant membranous vesicles. All these effects are not observed in Irvalec-resistant cells, or are significantly delayed by pretreating the cells with Zn2+. Using fluorescent derivatives of Irvalec it was demonstrated that the compound rapidly interacts with the plasma membrane of tumor cells promoting lipid bilayer restructuration. Also, FRET experiments demonstrated that Irvalec molecules localize in the cell membrane close enough to each other as to suggest that the compound could self-organize, forming supramolecular structures that likely trigger cell death by necrosis through the disruption of membrane integrity

Effects of coffee with different roasting degrees on obesity and related metabolic disorders

This study aimed to assess the effect of unroasted, dark and very dark roasted coffee on obesity and metabolic disorders in obese rats. All coffee samples significantly reduced weight gain (∼17%) compared to obese control. Coffee reduced glucose levels (∼17%) upon a glucose tolerance test in all cases compared to the control, while fasting glucose only decreased (∼26%) with very dark coffee. Insulin levels and insulin resistance significantly decreased (∼77% and 65% respectively) with all coffee samples compared to the control. Unroasted and dark roasted coffee decreased triglycerides (∼21% and ∼ 11%, respectively), and unroasted coffee also reduced free fatty acids (∼43%) and adipocyte size. Coffee decreased liver steatosis (∼55%) and Caspase-3 levels (∼27%), regardless of the roasting degree. Overall, coffee plays a positive role in restraining obesity and related metabolic disorders but, depending on the metabolic pathway and relevant marker, an effect of roasting could be either found or not

The Application of Reproductive Technologies to Natural Populations of Red Deer

P. 93-102Over the past decade, there has been increasing interest in the application of reproductive technology to the conservation and management of natural populations of deer. The application of assisted reproduction technologies within natural population of deer is in its infancy. However, its future potential is enormous, particularly in relation to genetic management or conservation. This paper reviews the present state of such technologies for a wild subspecies of red deer, the Iberian red deer (Cervus elaphus hispanicus), by discussing the major components of oestrous synchronization, semen collection/cryopreservation and insemination techniques. In addition, findings made during the course of studies on natural populations have enormous potential for the understanding of novel reproductive mechanism that may not be uncovered by livestock or human studies. A summary of these results are also reviewed her