910 research outputs found

    Focusing RF-on demand by logarithmic frequency-diverse arrays

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    The radiating systems exploiting the frequency diversity of the antennas are powerful architectures, that can have a big impact on wireless power transmission applications, but their characterization is merely theoretical. This paper offers a deep and critical numerical analysis of frequency- diverse arrays and shows the advantages of the family with logarithmic distribution of the frequency for radio-frequency energy focusing goals. For the first time, these systems are analyzed through a Harmonic Balance-based simulation combined with the full-wave description of the array made of eight planar monopoles: the rigorous results confirm the potentialities of these complex radiating systems, in particular show how the time-dependency of the radiating mechanism can be favorably deployed

    An analytical approach to reveal the addition of heat-denatured whey proteins in lab-scale cheese making

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    A simple analytical procedure for the detection of self-aggregated heat-denatured whey proteins (HDWP) in model cheeses was developed. The principle of the approach lies in the solubilization of the cheese matrix by a sodium citrate solution (0.2 M, pH 7.0) resulting in the dissociation of the casein micelles and the insolubilization of HDWP aggregates, which are collected in the pellet after a centrifugation step. The reliability of the procedure was tested in lab-scale cheeses from peroxidase-positive pasteurized milk with different protein-based ingredients (microparticulated whey protein concentrate, milk protein concentrate, whey protein isolate and Ricotta cheese) at concentrations ranging from 0.2 to 1.2% protein (w/v on cheese milk). A linear relationship between the amount of the HDWP added to cheese milk and that recovered from model cheeses was observed. Heat-damage indicators, furosine and lysinoalanine, showed levels in the experimental cheese samples not related with added HDWP, but represented a source of information on the ingredients other than liquid milk. Overall, in the model cheeses, the proposed method was an easy-to-apply and reliable tool for the evaluation of the presence of HDWP-based products. Further investigation is required for the application to real cheeses and for the evaluation of possible interferences from proteolysis during ripening

    Comparison between BNP values measured in capillary blood samples with a POCT method and those measured in plasma venous samples with an automated platform

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    Letter to the Editor. Our data suggest that it is possible to measure BNP in fresh finger-stick samples of capillary whole blood with an acceptable reproducibility, and within 10 ā€“ 20 min to obtain results close correlated to those measured by the automated platform in plasma blood samples collected from a vein. The measurement of BNP in fresh finger-stick samples of capillary whole blood with this POCT method is in particular indicated for the management of HF patients at home and for the BNP assay in neonates and children

    An all-in-one dual band blade antenna for ads-b and 5g communications in uav assisted wireless networks

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    This paper is aimed at the characterization and manufacturing of an SMA coaxial fed com-pact blade antenna with dual frequency characteristics for broadband applications on board of Unmanned Air Vehicles (UAVs). This antenna is linearly polarized, and it combines the benefits of Automatic Dependent Surveillance-Broadcast (ADS-B) and 5th Generation (5G) communications in one single element, covering both the 1.030ā€“1.090 GHz and the 3.4ā€“3.8 GHz bands thanks to a bent side and a ā€˜Cā€™ shaped slot within the radiation element. Starting from the simulation outcomes on an ideal ground plane, the results are here extended to a bent ground plane and on two UAV com-mercial CAD models. Details of manufacturing of the antenna in both aluminium and FR-4 substrate materials are presented. The comparison between measurements and simulations is discussed in terms of return loss, bandwidth, gain, and radiation pattern. Results show an antenna with a low profile and a simple structure that can be employed in various wideband communication systems, suiting future UAV assisted 5G networks while being perfectly compliant with forthcoming ADS-B based Detect-And-Avoid (DAA) technologies in Unmanned Aerial Traffic Management (UTM)

    Obesity and physical activity in children of immigrants.

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    Childhood overweight and obesity have increased in recent decades, reaching alarming proportions. Children with a migrant background seem to be particularly at risk of developing overweight and obesity. This article provides an overview of the prevalence of overweight or obesity among North African (NA) children living in their own countries or as immigrants in Europe. The aim is to show the effect of the migration process on this trend and to discuss its possible contributing factors. Publications were identified by a systematic search of PubMed and the existing literature. Original longitudinal or cross-sectional studies on the prevalence of childhood and adolescent overweight and obesity and of physical activity among ethnic groups from North Africa compared with the native population were reviewed. The results confirmed that children of NA origin in Europe have higher levels of overweight and obesity than the native ones, especially girls. However, this trend can also be detected in urban areas of NA countries. Important factors contributing to the increase of overweight and obesity among children and adolescents are discussed, in particular the westernization of eating habits, the level of physical activity and body image perception. The review shows that factors linked to acculturation in the host society and others maintained from the country of origin come into play in determining childhood overweight and obesity among NA immigrants in Europe. The importance of health promotion targeting the groups most at risk of childhood overweight and obesity, i.e. aspects of a healthy diet and the benefits of physical activity, is underlined

    A Multi-Frequency Investigation of Air-To-Ground Urban Propagation Using a GPU-based Ray Launching Algorithm

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    Unmanned Aerial Vehicles (UAV), also known as ā€œdronesā€, are attracting increasing attention as enablers for many technical applications and services, and this trend is likely to continue in the next future. When compared to conventional terrestrial communications, those making use of UAVs as base- or relay-stations can definitely be more useful and flexible in reaction to specific events, like natural disasters and terrorist attacks. Among the many and different fields, UAV enabled communications emerge as one of the most promising solutions for next-generation mobile networks, with a special focus on the extension of coverage and capacity of mobile radio networks. Motivated by the air-to-ground (A2G) propagation conditions which are likely to be different than those experienced by traditional ground communication systems, this paper aims at investigating the narrowband properties of the air-to-ground channel for 5G communications and beyond by means of GPU accelerated ray launching simulations. Line of sight probability as well as path loss exponent and shadowing standard deviations are analysed for different UAV flight levels, frequencies and dense urban scenarios, and for different types of on board antennas. Thanks to the flexibility of the ray approach, the role played by the different electromagnetic interactions, namely reflection, diffraction and diffuse scattering, in the air-to-ground propagation process is also investigated. Computation time is reported as well to show that designing UAV communication networks and optimising their performances in a fast and reliable manner, might avoid exhausting ā€“ multiple - measurement campaigns

    A perturbed MicroRNA expression pattern characterizes embryonic neural stem cells derived from a severe mouse model of spinal muscular atrophy (SMA)

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    Spinal muscular atrophy (SMA) is an inherited neuromuscular disorder and the leading genetic cause of death in infants. Despite the disease-causing gene, survival motor neuron (SMN1), encodes a ubiquitous protein, SMN1 deficiency preferentially affects spinal motor neurons (MNs), leaving the basis of this selective cell damage still unexplained. As neural stem cells (NSCs) are multipotent self-renewing cells that can differentiate into neurons, they represent an in vitro model for elucidating the pathogenetic mechanism of neurodegenerative diseases such as SMA. Here we characterize for the first time neural stem cells (NSCs) derived from embryonic spinal cords of a severe SMNĪ”7 SMA mouse model. SMNĪ”7 NSCs behave as their wild type (WT) counterparts, when we consider neurosphere formation ability and the expression levels of specific regional and self-renewal markers. However, they show a perturbed cell cycle phase distribution and an increased proliferation rate compared to wild type cells. Moreover, SMNĪ”7 NSCs are characterized by the differential expression of a limited number of miRNAs, among which miR-335-5p and miR-100-5p, reduced in SMNĪ”7 NSCs compared to WT cells. We suggest that such miRNAs may be related to the proliferation differences characterizing SMNĪ”7 NSCs, and may be potentially involved in the molecular mechanisms of SMA

    Dendrimer-coated carbon nanotubes deliver dsRNA and increase the efficacy of gene knockdown in the red flour beetle Tribolium castaneum

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    Thanks to Dr Alan S. Bowman at the Institute for Biological and Environmental Sciences, University of Aberdeen for providing facilities and laboratory equipment for insect work and to Kevin S. Mackenzie and staff at the Microscopy and Histology Core Facility at the University of Aberdeen for TEM preparations. Scottish Crucible Project Award 2014 provided financial support for this research. CHE was supported by a Knowledge Transfer Network BBSRC Industrial Case (BB/L502467/1) studentship. CRC was supported by a KTN BBSRC CASE studentship (BB/M503526/1). AM and AC were supported by the Italian Ministry of Health (RF-PE-2011-02347026). EMC was supported by European Unionā€™s Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 613960 (SMARTBEES) and Veterinary Medicines Directorate, Department for Environment Food & Rural Affairs (Project # VM0517).Peer reviewedPublisher PD
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