| 1. |
- Khatri, B., et al.
(author)
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Genome-wide association study identifies Sjogren's risk loci with functional implications in immune and glandular cells
- 2022
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Journal article (peer-reviewed)abstract
- Sjogren's disease is a complex autoimmune disease with twelve established susceptibility loci. This genome-wide association study (GWAS) identifies ten novel genome-wide significant (GWS) regions in Sjogren's cases of European ancestry: CD247, NAB1, PTTG1-MIR146A, PRDM1-ATG5, TNFAIP3, XKR6, MAPT-CRHR1, RPTOR-CHMP6-BAIAP6, TYK2, SYNGR1. Polygenic risk scores yield predictability (AUROC = 0.71) and relative risk of 12.08. Interrogation of bioinformatics databases refine the associations, define local regulatory networks of GWS SNPs from the 95% credible set, and expand the implicated gene list to >40. Many GWS SNPs are eQTLs for genes within topologically associated domains in immune cells and/or eQTLs in the main target tissue, salivary glands. The genetic architecture underlying Sjogren's syndrome is not fully understood. Here, the authors perform a genome-wide association study to identify 10 new genetic risk regions, implicating genes involved in immune and salivary gland function.
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| 2. |
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| 4. |
- Mayes, Maureen D, et al.
(author)
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Immunochip analysis identifies multiple susceptibility Loci for systemic sclerosis.
- 2014
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In: American Journal of Human Genetics. - : Elsevier BV. - 0002-9297 .- 1537-6605. ; 94:1, s. 47-61
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Journal article (peer-reviewed)abstract
- In this study, 1,833 systemic sclerosis (SSc) cases and 3,466 controls were genotyped with the Immunochip array. Classical alleles, amino acid residues, and SNPs across the human leukocyte antigen (HLA) region were imputed and tested. These analyses resulted in a model composed of six polymorphic amino acid positions and seven SNPs that explained the observed significant associations in the region. In addition, a replication step comprising 4,017 SSc cases and 5,935 controls was carried out for several selected non-HLA variants, reaching a total of 5,850 cases and 9,401 controls of European ancestry. Following this strategy, we identified and validated three SSc risk loci, including DNASE1L3 at 3p14, the SCHIP1-IL12A locus at 3q25, and ATG5 at 6q21, as well as a suggested association of the TREH-DDX6 locus at 11q23. The associations of several previously reported SSc risk loci were validated and further refined, and the observed peak of association in PXK was related to DNASE1L3. Our study has increased the number of known genetic associations with SSc, provided further insight into the pleiotropic effects of shared autoimmune risk factors, and highlighted the power of dense mapping for detecting previously overlooked susceptibility loci.
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| 5. |
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| 6. |
- Johannesson, M, et al.
(author)
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A resource for the simultaneous high-resolution mapping of multiple quantitative trait loci in rats: the NIH heterogeneous stock
- 2009
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In: Genome research. - : Cold Spring Harbor Laboratory. - 1088-9051. ; 19:1, s. 150-158
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Journal article (peer-reviewed)abstract
- The laboratory rat (Rattus norvegicus) is a key tool for the study of medicine and pharmacology for human health. A large database of phenotypes for integrated fields such as cardiovascular, neuroscience, and exercise physiology exists in the literature. However, the molecular characterization of the genetic loci that give rise to variation in these traits has proven to be difficult. Here we show how one obstacle to progress, the fine-mapping of quantitative trait loci (QTL), can be overcome by using an outbred population of rats. By use of a genetically heterogeneous stock of rats, we map a locus contributing to variation in a fear-related measure (two-way active avoidance in the shuttle box) to a region on chromosome 5 containing nine genes. By establishing a protocol measuring multiple phenotypes including immunology, neuroinflammation, and hematology, as well as cardiovascular, metabolic, and behavioral traits, we establish the rat HS as a new resource for the fine-mapping of QTLs contributing to variation in complex traits of biomedical relevance.
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| 11. |
- Khatri, B, et al.
(author)
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GENOME-WIDE ASSOCIATION STUDY OF SJOGREN'S SYNDROME IDENTIFIES TEN NEW RISK LOCI
- 2020
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In: ANNALS OF THE RHEUMATIC DISEASES. - : BMJ. - 0003-4967 .- 1468-2060. ; 79, s. 30-31
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Conference paper (other academic/artistic)abstract
- Sjögren’s syndrome (SS) is a complex autoimmune disease with exocrine gland dysfunction leading to substantial morbidity. There are 10 published genetic susceptibility loci.Objectives:Our genome-wide association study (GWAS) aimed to identify additional risk loci of genome-wide significance (GWS; p<5E-08) in European-derived primary SS.Methods:A total of 3232 cases and 17481 controls genotyped on GWAS arrays and 619 cases and 6171 controls genotyped on ImmunoChip (IC) arrays were imputed after quality control. Logistic regression was calculated adjusting for ancestry using the first 4 principal components to identify SS-associated SNPs. GWAS and IC results were meta-analyzed using weighted Z-scores. Bayesian statistics were used to assign posterior probabilities and define credible SNP sets for each locus. Bioinformatic analyses were used to predict functionality.Results:Seven novel loci exceeded GWS in the GWAS analysis:NAB1,MIR146A-PTTG1,XKR6,MAPT-CRHR1,RPTOR-CHMP6-BAIAP2,TYK2andSYNGR1. Meta-analysis with IC data identified three more novel loci exceeding GWS:CD247,PRDM1-ATG5andTNFAIP3. Several additional loci with suggestive association (p<1E-05) were also identified:ADAMTSL2,CGNL1andPHRF1.Several identified loci have reported functional implications in immune regulation and autoimmune disease. In lupus, rs2431697 correlated with rs2431098, which was shown to alterMIR146Aexpression, resulting in type I interferon pathway imbalance. Similarly,TYK2risk association reportedly drives interferon, IL10 and RET signaling pathways.PRDM1encodes Blimp-1, a master regulator of immune cell differentiation.CD247encodes the zeta subunit of the T cell receptor complex.XKR6is implicated in apoptotic cell ingestion.ATG5is also involved in apoptosis, as well as autophagy and antigen presentation.Additional bioinformatics analyses (Haploreg, Regulome DB, ENCODE, etc.) revealed immune-relevant functional implications for each risk locus. The SS-associated credible set included variants downstream ofTNFAIP3in a region reported to abolish looping between an enhancer and theTNFAIP3promoter in lupus and a coding variant that has been shown to alter NF-kB activity and neutrophil extra-cellular traps. The rs2293765 in the 5’ UTR ofNAB1showed evidence of enhancer/promoter activities. The rs2069235 in theSYNGR1locus showed enhancer and transcription start site activities in B and T cells. The rs7210219 in theMAPT-CRHR1locus showed enhancer/promotor activities in various tissues.Conclusion:We have identified ten novel genetic susceptibility loci associated with SS pathology. Our finding increases the current number of GWS regions in SS patients of European origin, from 10 to 20. Future work is needed to identify and characterize the functional variants in each region.Disclosure of Interests:Bhuwan Khatri: None declared, Tove Ragna Reksten: None declared, Kandice L Tessneer: None declared, Astrid Rasmussen Speakers bureau: Novartis, ThermoFischer, R Hal Scofield Grant/research support from: Pfizer, Simon J. Bowman Consultant of: Astrazeneca, Biogen, BMS, Celgene, Medimmune, MTPharma, Novartis, Ono, UCB, xtlbio, Glapagos, Speakers bureau: Novartis, Joel Guthridge Grant/research support from: Xencor, Bristol Myers Squibb, DXterity, Judith A. James Grant/research support from: Progentec Diagnostics, Inc, Consultant of: Abbvie, Novartis, Jannsen, Lars Ronnblom Grant/research support from: AZ, Speakers bureau: AZ, Blake M Warner: None declared, Xavier Mariette: None declared, Roald Omdal: None declared, Javier Martin Ibanez: None declared, Maria Teruel: None declared, Janicke Liaaen Jensen: None declared, Lara A Aqrawi: None declared, Øyvind Palm: None declared, Marie Wahren-Herlenius: None declared, Torsten Witte: None declared, Roland Jonsson: None declared, Maureen Rischmueller: None declared, A Darise Farris Speakers bureau: Biogen, Marta Alarcon-Riquelme: None declared, Wan-fai Ng: None declared, Kathy L Sivils: None declared, Gunnel Nordmark: None declared, Christopher Lessard: None declared
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| 12. |
- Teruel, M, et al.
(author)
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Integrative epigenomics in Sjögren´s syndrome reveals novel pathways and a strong interaction between the HLA, autoantibodies and the interferon signature
- 2021
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In: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1, s. 23292-
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Journal article (peer-reviewed)abstract
- Primary Sjögren’s syndrome (SS) is a systemic autoimmune disease characterized by lymphocytic infiltration and damage of exocrine salivary and lacrimal glands. The etiology of SS is complex with environmental triggers and genetic factors involved. By conducting an integrated multi-omics study, we confirmed a vast coordinated hypomethylation and overexpression effects in IFN-related genes, what is known as the IFN signature. Stratified and conditional analyses suggest a strong interaction between SS-associated HLA genetic variation and the presence of Anti-Ro/SSA autoantibodies in driving the IFN epigenetic signature and determining SS. We report a novel epigenetic signature characterized by increased DNA methylation levels in a large number of genes enriched in pathways such as collagen metabolism and extracellular matrix organization. We identified potential new genetic variants associated with SS that might mediate their risk by altering DNA methylation or gene expression patterns, as well as disease-interacting genetic variants that exhibit regulatory function only in the SS population. Our study sheds new light on the interaction between genetics, autoantibody profiles, DNA methylation and gene expression in SS, and contributes to elucidate the genetic architecture of gene regulation in an autoimmune population.
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| 13. |
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| 17. |
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| 18. |
- Chen, Z. -L, et al.
(author)
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Artificial maxwell fisheye lens design and synthesis with using metasurface structure
- 2015
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In: 2015 International Workshop on Electromagnetics. - : Institute of Electrical and Electronics Engineers Inc.. - 9781467369527
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Conference paper (peer-reviewed)abstract
- In this paper, we use a periodic structure to produce a Maxwell's fisheye lens and investigate some important information such as power, efficiency, etc. At Chapter 1, we describe some introduction about the surface plasmon polariton (SPP), frequency selective surface (FSS), concentration power by using lens. At Chapter 2, we describe some theorem about we need to use like Transmission line modal, high impedance surface, periodic structure lens. At Chapter 3, we describe our design and we show some simulation results about the surface wave Maxwell's fisheye lens. At chapter 4, we discuss our results about the fisheye lens. At chapter 5, we will draw the conclusions.
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| 19. |
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| 20. |
- Gorlova, Olga, et al.
(author)
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Identification of Novel Genetic Markers Associated with Clinical Phenotypes of Systemic Sclerosis through a Genome-Wide Association Strategy
- 2011
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In: PLoS Genetics. - : Public Library of Science (PLoS). - 1553-7404. ; 7:7
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Journal article (peer-reviewed)abstract
- The aim of this study was to determine, through a genome-wide association study (GWAS), the genetic components contributing to different clinical sub-phenotypes of systemic sclerosis (SSc). We considered limited (IcSSc) and diffuse (dcSSc) cutaneous involvement, and the relationships with presence of the SSc-specific auto-antibodies, anti-centromere (ACA), and anti-topoisomerase I (ATA). Four GWAS cohorts, comprising 2,296 SSc patients and 5,171 healthy controls, were meta-analyzed looking for associations in the selected subgroups. Eighteen polymorphisms were further tested in nine independent cohorts comprising an additional 3,175 SSc patients and 4,971 controls. Conditional analysis for associated SNPs in the HLA region was performed to explore their independent association in antibody subgroups. Overall analysis showed that non-HLA polymorphism rs11642873 in IRF8 gene to be associated at GWAS level with lcSSc (P = 2.32x10(-12), OR = 0.75). Also, rs12540874 in GRB10 gene (P = 1.27 x 10(-6), OR = 1.15) and rs11047102 in SOX5 gene (P = 1.39x10(-7), OR = 1.36) showed a suggestive association with lcSSc and ACA subgroups respectively. In the HLA region, we observed highly associated allelic combinations in the HLA-DQB1 locus with ACA (P = 1.79x10(-61), OR = 2.48), in the HLA-DPA1/B1 loci with ATA (P = 4.57x10(-76), OR = 8.84), and in NOTCH4 with ACA P = 8.84x10(-21), OR = 0.55) and ATA (P = 1.14x10(-8), OR = 0.54). We have identified three new non-HLA genes (IRF8, GRB10, and SOX5) associated with SSc clinical and autoantibody subgroups. Within the HLA region, HLA-DQB1, HLA-DPA1/B1, and NOTCH4 associations with SSc are likely confined to specific auto-antibodies. These data emphasize the differential genetic components of subphenotypes of SSc.
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| 21. |
- Hsieh, K. -H, et al.
(author)
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The manipulation of surface plasmon polaritons and design of luneburg lens based on periodic patch arrays
- 2015
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In: 2015 International Workshop on Electromagnetics. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781467369527 ; , s. 1-2
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Conference paper (peer-reviewed)abstract
- We present a surface constitutes arrays of periodic patches, which may serve as the metasurface to synthesize the Luneburg lens. The main purpose is by using different sizes of patches to achieve different refractive index at each stage, and get the proper function of Luneburg lens.
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| 22. |
- McCall, Martin, et al.
(author)
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Roadmap on transformation optics
- 2018
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In: Journal of Optics. - : IOP Publishing. - 2040-8978 .- 2040-8986. ; 20:6
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Research review (peer-reviewed)abstract
- Transformation optics asks, using Maxwell's equations, what kind of electromagnetic medium recreates some smooth deformation of space? The guiding principle is Einstein's principle of covariance: that any physical theory must take the same form in any coordinate system. This requirement fixes very precisely the required electromagnetic medium. The impact of this insight cannot be overestimated. Many practitioners were used to thinking that only a few analytic solutions to Maxwell's equations existed, such as the monochromatic plane wave in a homogeneous, isotropic medium. At a stroke, transformation optics increases that landscape from 'few' to 'infinity', and to each of the infinitude of analytic solutions dreamt up by the researcher, there corresponds an electromagnetic medium capable of reproducing that solution precisely. The most striking example is the electromagnetic cloak, thought to be an unreachable dream of science fiction writers, but realised in the laboratory a few months after the papers proposing the possibility were published. But the practical challenges are considerable, requiring meta-media that are at once electrically and magnetically inhomogeneous and anisotropic. How far have we come since the first demonstrations over a decade ago? And what does the future hold? If the wizardry of perfect macroscopic optical invisibility still eludes us in practice, then what compromises still enable us to create interesting, useful, devices? While three-dimensional (3D) cloaking remains a significant technical challenge, much progress has been made in two dimensions. Carpet cloaking, wherein an object is hidden under a surface that appears optically flat, relaxes the constraints of extreme electromagnetic parameters. Surface wave cloaking guides sub-wavelength surface waves, making uneven surfaces appear flat. Two dimensions is also the setting in which conformal and complex coordinate transformations are realisable, and the possibilities in this restricted domain do not appear to have been exhausted yet. Beyond cloaking, the enhanced electromagnetic landscape provided by transformation optics has shown how fully analytic solutions can be found to a number of physical scenarios such as plasmonic systems used in electron energy loss spectroscopy and cathodoluminescence. Are there further fields to be enriched? A new twist to transformation optics was the extension to the spacetime domain. By applying transformations to spacetime, rather than just space, it was shown that events rather than objects could be hidden from view; transformation optics had provided a means of effectively redacting events from history. The hype quickly settled into serious nonlinear optical experiments that demonstrated the soundness of the idea, and it is now possible to consider the practical implications, particularly in optical signal processing, of having an 'interrupt-without-interrupt' facility that the so-called temporal cloak provides. Inevitable issues of dispersion in actual systems have only begun to be addressed. Now that time is included in the programme of transformation optics, it is natural to ask what role ideas from general relativity can play in shaping the future of transformation optics. Indeed, one of the earliest papers on transformation optics was provocatively titled 'General Relativity in Electrical Engineering'. The answer that curvature does not enter directly into transformation optics merely encourages us to speculate on the role of transformation optics in defining laboratory analogues. Quite why Maxwell's theory defines a 'perfect' transformation theory, while other areas of physics such as acoustics are not apparently quite so amenable, is a deep question whose precise, mathematical answer will help inform us of the extent to which similar ideas can be extended to other fields. The contributors to this Roadmap, who are all renowned practitioners or inventors of transformation optics, will give their perspectives into the field's status and future development.
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| 23. |
- Pan, C. -W, et al.
(author)
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Microwave focusing lenses by synthesized with positive or negative refractive index split-ring resonator metamaterials
- 2015
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In: 2015 International Workshop on Electromagnetics. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781467369527
-
Conference paper (peer-reviewed)abstract
- Metamaterials had been widely investigated in literature and experiment in recent years, because of they are able to produce unusual permittivity and permeability which can be used to improve the performance of conventional devices [1]. Metamaterial structures designed to have simultaneously negative permittivity and permeability are known as left-handed materials (LHM) [2]. LHM produce negative refraction index and generate the backward-wave. LHM can be employed to design transformed lenses with better focusing efficiency than conventional ones. In this paper, we make use of squared split-ring resonators to synthesize a number of lenses. Particularly, we synthesize a negative refraction index lens and a parabolic refraction lens. CST has been employed to demonstrate the performance of the focusing system.
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| 24. |
- Quevedo-Teruel, Oscar, et al.
(author)
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Planar lenses by tailoring holey waveguides
- 2015
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In: 2015 USNC-URSI Radio Science Meeting (Joint with AP-S Symposium), USNC-URSI 2015 - Proceedings. - : IEEE. - 9781479978175 ; , s. 34-
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Conference paper (peer-reviewed)abstract
- In recent years there has been an increased demand for directive antennas at high frequencies. There are different solutions to increase the directivity of those antennas such as reflectors, lenses or arrays. Nevertheless, reflectors are bulky, devices at those frequencies. Thus, lenses have become a suitable solution for the new generation of antennas.
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| 25. |
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| 26. |
- Alex-Amor, Antonio, et al.
(author)
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Elliptical Glide-Symmetric Holey Metasurfaces for Wideband Anisotropy
- 2020
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In: 2020 14th European Conference on Antennas and Propagation (EUCAP 2020). - : Institute of Electrical and Electronics Engineers (IEEE).
-
Conference paper (peer-reviewed)abstract
- This paper presents a mode-matching technique to study the dispersive features of periodic structures composed of glide-symmetric elliptical holes. As a difference from purely numerical methods, our formulation provides physical insight on the Floquet harmonics. At the same time, the computational cost is reduced compared to general purpose commercial software. The fields inside the holes are described by means of Mathieu functions and subsequently used to compute the full 2-D dispersion diagrams. With the presented analysis, we demonstrate that glide-symmetric periodic structures with elliptical holes offer anisotropic refractive indexes over a wide range of frequencies.
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| 27. |
- Alex-Amor, Antonio, et al.
(author)
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Wave Propagation in Periodic Metallic Structures with Equilateral Triangular Holes
- 2020
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In: Applied Sciences. - : MDPI. - 2076-3417. ; 10:5
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Journal article (peer-reviewed)abstract
- This paper studies wave propagation in a periodic parallel-plate waveguide with equilateral triangular holes. A mode-matching method is implemented to analyze the dispersion diagram of the structure possessing glide and mirror symmetries. Both structures present an unexpected high degree of isotropy, despite the triangle not being symmetric with respect to rotations of 90 degrees. We give some physical insight on the matter by carrying out a modal decomposition of the total field on the hole and identifying the most significant modes. Additionally, we demonstrate that the electrical size of the triangular hole plays a fundamental role in the physical mechanism that causes that isotropic behavior. Finally, we characterize the influence of the different geometrical parameters that conform the unit cell (period, triangle size, hole depth, separation between metallic plates). The glide-symmetric configuration offers higher equivalent refractive indexes and widens the stopband compared to the mirror-symmetric configuration. We show that the stopband is wider as the triangle size is bigger, unlike holey structures composed of circular and elliptical holes where an optimal hole size exists.
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| 28. |
- Algaba-Brazalez, A., et al.
(author)
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Compact Polarization Transformation in a Geodesic Luneburg Lens Antenna
- 2021
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In: 2021 IEEE International Symposium on Antennas and Propagation and North American Radio Science Meeting, APS/URSI 2021 - Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. ; , s. 1992-1993
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Conference paper (peer-reviewed)abstract
- This paper describes the design of a compact polarizer that rotates the linear polarization of a fully metallic geodesic Luneburg lens antenna for applications requiring polarization diversity. The polarization rotation is achieved by loading the radiating aperture of the antenna with two metallic screens. The integrated antenna operates in the Ka-band, from 25 to 31 GHz, showing around 20% bandwidth with S11 below -10 dB, and a scanning range of 100°.
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| 29. |
- Flores-Espinosa, Núria, et al.
(author)
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Design of a Dielectric Lens Using a Ray-Tracing Model for Satellite Communications
- 2024
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In: 18th European Conference on Antennas and Propagation, EuCAP 2024. - : Institute of Electrical and Electronics Engineers (IEEE).
-
Conference paper (peer-reviewed)abstract
- In millimeter-wave applications, it is essential to use highly directional and steerable antennas. Phased array antennas are the most common choice, but they have restricted scanning coverage because of their effective aperture. To enhance the scanning coverage, a dielectric lens can be placed on top of the array. However, full-wave simulations require a lot of computing time to simulate this type of structure. In this work, a two-dimensional ray-tracing model has been adapted and improved to efficiently compute the radiation pattern of arrays combined with multilayered dielectric radomes for satellite communications applications. Moreover, this model can also calculate the absorption and reflection losses and the transmitted power required to comply with the regulatory mask. This model has been used to design a lens that increases the scanning range of an array while maintaining a maximum height and ensuring that it complies with the regulatory masks for satellite communications.
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| 30. |
- Fredholm, BB, et al.
(author)
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Consequences of eliminating adenosine A(1) receptors in mice
- 2003
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In: Drug Development Research (Proceedings of the Seventh International Symposium on Adenosine and Adenine Nucleotides - Part 1). - : Wiley. - 1098-2299 .- 0272-4391. ; 58, s. 350-
-
Conference paper (peer-reviewed)abstract
- The second coding exon of the adenosine A, receptor gene was eliminated by homologous recombination. The phenotype of mice (mixed C57B6/129OlaHsd background) was studied, using siblings from matings of heterozygous mice. Among the offspring the ratio between+/+, +/-and -/-animals was 1:2:1. Over the first half-year-at least-growth and viability were the same in all genotypes. Binding of A(1) ligands was eliminated in-/-mice and halved in+/-mice. Blood pressure was increased in-/-mice and this was paralleled by an increase in plasma renin. Heart rate was unaffected, as was contractility. Furthermore, the response of the perfused heart to ischemia was similar in+/+and -/-hearts. However, remote preconditioning was eliminated in-/-mouse hearts. Tubuloglomerular feedback in the kidney was also lost in-/-mice. The analgesic response to a non-selective adenosing receptor agonist was lost in-/-mice, which also showed hyperalgesia in the tail-flick test. There was a slight hypoactivity in-/-mice, but responses to caffeine were essentially normal. The inhibition of excitatory neurotransmission in hippocampus by adenosine was lost in-/-mice and reduced in+/-mice. Responses to ATP were affected similarly. Hypoxic depression of synaptic transmission was essentially eliminated in hippocampus and hypoxic decrease in spinal respiratory neuron firing was markedly reduced. These results show that adenosine A, receptors play a physiologically important role in the kidney, spinal cord, and hippocampus and that they are critically important in the adaptive responses to hypoxia. (C) 2003 Wiley-Liss, Inc.
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| 36. |
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| 37. |
- Lona-Durazo, Frida, et al.
(author)
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Meta-analysis of GWA studies provides new insights on the genetic architecture of skin pigmentation in recently admixed populations
- 2019
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In: BMC Genetics. - : BMC. - 1471-2156. ; 20
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Journal article (peer-reviewed)abstract
- Background: Association studies in recently admixed populations are extremely useful to identify the genetic architecture of pigmentation, due to their high genotypic and phenotypic variation. However, to date only four Genome-Wide Association Studies (GWAS) have been carried out in these populations.Results: We present a GWAS of skin pigmentation in an admixed sample from Cuba (N=762). Additionally, we conducted a meta-analysis including the Cuban sample, and admixed samples from Cape Verde, Puerto Rico and African-Americans from San Francisco. This meta-analysis is one of the largest efforts so far to characterize the genetic basis of skin pigmentation in admixed populations (N=2,104). We identified five genome-wide significant regions in the meta-analysis, and explored if the markers observed in these regions are associated with the expression of relevant pigmentary genes in human melanocyte cultures. In three of the regions identified in the meta-analysis (SLC24A5, SLC45A2, and GRM5/TYR), the association seems to be driven by non-synonymous variants (rs1426654, rs16891982, and rs1042602, respectively). The rs16891982 polymorphism is strongly associated with the expression of the SLC45A2 gene. In the GRM5/TYR region, in addition to the rs1042602 non-synonymous SNP located on the TYR gene, variants located in the nearby GRM5 gene have an independent effect on pigmentation, possibly through regulation of gene expression of the TYR gene. We also replicated an association recently described near the MFSD12 gene on chromosome 19 (lead variant rs112332856). Additionally, our analyses support the presence of multiple signals in the OCA2/HERC2/APBA2 region on chromosome 15. A clear causal candidate is the HERC2 intronic variant rs12913832, which has a profound influence on OCA2 expression. This variant has pleiotropic effects on eye, hair, and skin pigmentation. However, conditional and haplotype-based analyses indicate the presence of other variants with independent effects on melanin levels in OCA2 and APBA2. Finally, a follow-up of genome-wide signals identified in a recent GWAS for tanning response indicates that there is a substantial overlap in the genetic factors influencing skin pigmentation and tanning response.Conclusions: Our meta-analysis of skin pigmentation GWAS in recently admixed populations provides new insights about the genetic architecture of this complex trait.
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| 38. |
- Luján, M. Á, et al.
(author)
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Mental Disorder Diagnosis from EEG Signals Employing Automated Leaning Procedures Based on Radial Basis Functions
- 2022
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In: Journal of Medical and Biological Engineering. - : Springer Nature. - 1609-0985 .- 2199-4757. ; 42:6, s. 853-859
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Journal article (peer-reviewed)abstract
- Purpose: In this paper, a new automated procedure based on deep learning methods for schizophrenia diagnosis is presented. Methods: To this aim, electroencephalogram signals obtained using a 32-channel helmet are prominently used to analyze high temporal resolution information from the brain. By these means, the data collected is employed to evaluate the class likelihoods using a neuronal network based on radial basis functions and a fuzzy means algorithm. Results: The results obtained with real datasets validate the high accuracy of the proposed classification method. Thus, effectively characterizing the changes in EEG signals acquired from schizophrenia patients and healthy volunteers. More specifically, values of accuracy better than 93% has been obtained in the present research. Additionally, a comparative study with other approaches based on well-knows machine learning methods shows that the proposed method provides better results than recently proposed algorithms in schizophrenia detection. Conclusion: The proposed method can be used as a diagnostic tool in the detection of the schizophrenia, helping for early diagnosis and treatment.
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| 39. |
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| 40. |
- Manholm, L., et al.
(author)
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A two-dimensional all metal Luneburg lens using glide-symmetric holey metasurface
- 2018
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In: IET Conference Publications. - : Institution of Engineering and Technology.
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Conference paper (peer-reviewed)abstract
- A two-dimensional Luneburg lens multiport antenna at 28GHz is presented, where an all metal metasurface structure is used to control the effective refractive index. The metasurface lens has glide-symmetric pin-loaded holes in the two plates of the parallel plate waveguide lens. This glide-symmetric configuration enhances the bandwidth of operation for the same equivalent refractive index. Excellent port matching and radiation performance are demonstrated through simulations of the complete antenna that is fed with 11 waveguides.
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| 41. |
- Mateo-Sotos, J., et al.
(author)
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A Machine Learning-Based Method to Identify Bipolar Disorder Patients
- 2022
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In: Circuits, systems, and signal processing. - : Springer Nature. - 0278-081X .- 1531-5878. ; 41:4, s. 2244-2265
-
Journal article (peer-reviewed)abstract
- Bipolar disorder is a serious psychiatric disorder characterized by periodic episodes of manic and depressive symptomatology. Due to the high percentage of people suffering from severe bipolar and depressive disorders, the modelling, characterisation, classification and diagnostic analysis of these mental disorders are of vital importance in medical research. Electroencephalogram (EEG) records offer important information to enhance clinical diagnosis and are widely used in hospitals. For this reason, EEG records and patient data from the Virgen de la Luz Hospital were used in this work. In this paper, an extreme gradient boosting (XGB) machine learning (ML) method involving an EEG signal is proposed. Four supervised ML algorithms including a k-nearest neighbours (KNN), decision tree (DT), Gaussian Naïve Bayes (GNB) and support vector machine (SVM) were compared with the proposed XGB method. The performance of these methods was tested implementing a standard 10-fold cross-validation process. The results indicate that the XGB has the best prediction accuracy (94%), high precision (> 0.94) and high recall (> 0.94). The KNN, SVM, and DT approaches also present moderate prediction accuracy (> 87), moderate recall (> 0.87) and moderate precision (> 0.87). The GNB algorithm shows relatively low classification performance. Based on these results for classification performance and prediction accuracy, the XGB is a solid candidate for a correct classification of patients with bipolar disorder. These findings suggest that XGB system trained with clinical data may serve as a new tool to assist in the diagnosis of patients with bipolar disorder.
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| 42. |
- Mitchell-Thomas, Rhiannon C., et al.
(author)
-
2D optical transformations for surfaces
- 2014
-
In: IEEE Antennas and Propagation Society, AP-S International Symposium (Digest). - 9781479935406 ; , s. 761-762
-
Conference paper (peer-reviewed)abstract
- This paper describes a two-dimensional optical transformation method that can be used to tailor the propagation of waves confined to a surface. Virtual and physical geometries are employed, and the equivalence of the wave behaviour on these two different surfaces is illustrated using full wave simulations of a graded-index loaded waveguide. This technique has great promise to design devices that are fabricated from metasurfaces.
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| 43. |
- Mitchell-Thomas, R. C., et al.
(author)
-
Lenses on curved surfaces
- 2014
-
In: Optics Letters. - 0146-9592 .- 1539-4794. ; 39:12, s. 3551-3554
-
Journal article (peer-reviewed)abstract
- This Letter presents a theory that allows graded index lenses to be mapped onto arbitrary rotationally symmetric curved surfaces. Examples of the Luneburg and Maxwell fish-eye lens are given, for numerous surfaces, always resulting in isotropic permittivity requirements. The performance of these lenses is initially illustrated with full-wave simulations utilizing a waveguide structure. A transformation of the refractive index profiles is then performed to design surface-wave lenses, where the dielectric layer is not only isotropic but also homogenous, demonstrating the applicability and ease of fabrication.
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| 44. |
- Mitchell-Thomas, R. C., et al.
(author)
-
The anti-fish eye cloak for surface wave antennas
- 2014
-
In: 8th European Conference on Antennas and Propagation, EuCAP 2014. - 9788890701849 ; , s. 267-268
-
Conference paper (peer-reviewed)abstract
- In this paper a new lens, named the anti-fish eye lens, is proposed and its relation to the Maxwell fish eye lens is described. This novel lens is then applied to cloak an object positioned underneath it, to electromagnetic waves that are confined to the surface. The performance of the lens in reforming the cylindrical wave fronts is illustrated with numerical simulations. This lens has direct applications for surface wave antennas that are conformal to curved structures to remove the influence of the curvature, the consequence of which would detrimentally affect the directivity because of the distortion of the wavefronts. Therefore, using this technique, the performance of surface wave antennas on curved surfaces can be equivalent to those on flat surfaces.
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| 45. |
- Padilla, Pablo, et al.
(author)
-
Broken Glide-Symmetric Holey Structures for Bandgap Selection in Gap-Waveguide Technology
- 2019
-
In: IEEE Microwave and Wireless Components Letters. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 1531-1309 .- 1558-1764. ; 29:5, s. 327-329
-
Journal article (peer-reviewed)abstract
- In this letter, we propose a new technique to tune the bandgap in gap-waveguide technology based on broken glide-symmetric holey structures. We demonstrate that breaking the glide-symmetry in a proper manner provokes the presence of a passband within the bandgap due to the frequency sweep of the second propagating mode. This passband generates field leakage in the gap that is translated into a filtering property. This filtering effect may be used to reduce or eliminate filters in large complex devices. In order to avoid undesired coupling due to the leakage from the air gap between the plates, an absorbing sheet is proposed to dissipate the undesired fields. This idea has been numerically studied and experimentally validated with a specific design, a WR15-size gap-waveguide prototype with glide-symmetric holes with filtering properties.
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| 46. |
- Padilla, P., et al.
(author)
-
Glide-symmetric holey structures with selected bandgaps for gap-waveguide technology
- 2018
-
In: IET Conference Publications. - : Institution of Engineering and Technology.
-
Conference paper (peer-reviewed)abstract
- Here, we propose a new technique to accurately define and select the bandgap regions in gap waveguide technology based on glide-symmetric holey structures. This selection is accomplished by breaking the symmetry of the periodic structure. The advantage of this proposal is that filtering properties are added intrinsically in the waveguides, reducing the total complexity of the overall device, in which additional filters may not be necessary.
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| 47. |
- Pérez-Andreu, V., et al.
(author)
-
miR-133a regulates Vitamin K 2,3-epoxide reductase complex subunit 1 (VKORC1), a key protein in the Vitamin K cycle
- 2012
-
In: Molecular Medicine. - : Springer Science and Business Media LLC. - 1076-1551 .- 1528-3658. ; 18:11, s. 1466-1472
-
Journal article (peer-reviewed)abstract
- Regulation of key proteins by microRNAs (miRNAs) is an emergent field in biomedicine. Vitamin K 2,3-epoxide reductase complex subunit 1 (VKORC1) is a relevant molecule for cardiovascular diseases, since it is the target of oral anticoagulant drugs and plays a role in soft tissue calcification. The objective of this study was to determine the influence of miRNAs on the expression of VKORC1. Potential miRNAs targeting VKORC1 mRNA were searched by using online algorithms. Validation studies were carried out in HepG2 cells by using miRNA precursors; direct miRNA interaction was investigated with reporter assays. In silico studies identified two putative conserved binding sites for miR-133a and miR-137 on VKORC1 mRNA. Ex vivo studies showed that only miR-133a was expressed in liver; transfection of miRNA precursors of miR-133a in HepG2 cells reduced VKORC1 mRNA expression in a dosedependent manner, as assessed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) as well as protein expression. Reporter assays in HEK293T cells showed that miR-133a interacts with the 3′UTR of VKORC1. Additionally, miR-133a levels correlated inversely with VKORC1 mRNA levels in 23 liver samples from healthy subjects. In conclusion, miR-133a appears to have a direct regulatory effect on expression of VKORC1 in humans; this regulation may have potential importance for anticoagulant therapy or aortic calcification.
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| 48. |
- Perez-Quintana, D., et al.
(author)
-
Compact Pillbox Reflector Based on Geodesic Lens
- 2022
-
In: 2022 16th International Congress on Artificial Materials for Novel Wave Phenomena, Metamaterials 2022. - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 341-343
-
Conference paper (peer-reviewed)abstract
- We propose a pillbox antenna in combination with a geodesic lens at 60 GHz. The antenna is implemented in a dual-layer parallel plate waveguide. The waves from a geodesic lens in a first layer, after being reflected by a parabolic mirror connecting the rims of the two layers, enter a second layer and illuminate the radiation aperture. Since the lens produces a virtual focus, the reflector works as if it is fed from that a further location, making the system more compact.
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| 49. |
- Petek, M., et al.
(author)
-
An Integral-Equation Kernel for Glide Symmetric Structures
- 2023
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In: 2023 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, AP-S/URSI 2023 - Proceedings. - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 555-556
-
Conference paper (peer-reviewed)abstract
- Glide-symmetric structures can improve properties of periodic structures for a wide variety of applications, such as lenses, filters and gap waveguides. Therefore, fast and accurate tools are needed to facilitate their use. In this work, we present a modelling approach based on a method of moments with a novel Green's function. The solutions are found as singularities of the impedance matrix. The results are shown to be in good agreement with a well-established method.
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| 50. |
- Petek, M., et al.
(author)
-
Efficient Integral Equation Approach for the Modelling of Glide-Symmetric Structures
- 2023
-
In: 2023 17th European Conference on Antennas and Propagation (EuCAP). - : Institute of Electrical and Electronics Engineers (IEEE).
-
Conference paper (peer-reviewed)abstract
- For the design of advanced microwave and antenna components, efficient and accurate electromagnetic methods are required. In this work, we present a technique to fast simulate mirror- and glide-symmetric periodic structures. More concretely, a novel Green's function is proposed which allows to reduce the computational domain to one half of the unit cell. Full dispersion diagrams are computed for metallic glide- and mirror-symmetric structures with three stages of mesh refinement. The results converge with the meshing and agree well with conventional eigenmode analyses.
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