118 research outputs found
A general approach for robust integrated polarization rotators
Integrated polarization rotators suffer from very high sensitivity to fabrication errors. A polarization rotator scheme that substantially increases fabrication tolerances is proposed. In the proposed scheme, two tunable polarization phase shifters are used to connect three rotator waveguide sections. By means of properly setting the polarization phase shifters, fabrication errors are compensated and perfect polarization rotation is achieved. Analytical conditions are shown that determine the maximum deviation that can be corrected with the proposed scheme. A design example is discussed, where the thermo-optic effect is used to provide the required tunable polarization phase shifting. Calculated 40dB extinction ratio is shown in presence of fabrication errors that would yield a 4dB extinction ratio in the conventional approach. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.The authors want to aknowledge Universidad de Målaga alaga, Campus de Excelencia Internacional Andalucia Tech for their support
The declining representativeness of the British party system, and why it matters
In a recent article, Michael Laver has explained âWhy Vote-Seeking Parties May Make Voters Miserableâ. His model shows that, while ideological convergence may boost congruence between governments and the median voter, it can reduce congruence between the party system and the electorate as a whole. Specifically, convergence can increase the mean distance between voters and their nearest party. In this article we show that this captures the reality of todayâs British party system. Policy scale placements in British Election Studies from 1987 to 2010 confirm that the pronounced convergence during the past decade has left the Conservatives and Labour closer together than would be optimal in terms of minimising the policy distance between the average voter and the nearest major party. We go on to demonstrate that this comes at a cost. Respondents who perceive themselves as further away from one of the major parties in the system tend to score lower on satisfaction with democracy. In short, vote-seeking parties have left the British party system less representative of the ideological diversity in the electorate, and thus made at least some British voters miserable
Robust and tunable integrated polarization rotator
Integrated polarization rotators suffer from very high sensitivity to fabrication errors. A polarization rotator scheme that substantially increases fabrication tolerances is proposed. In the proposed scheme, two tunable polarization phase shifters are used to connect three rotator waveguide sections. By means of properly setting the polarization phase shifters, fabrication errors are compensated and perfect polarization rotation is achieved. Analytical conditions are shown that determine the maximum deviation that can be corrected with the proposed scheme. A design example is discussed, where the thermo-optic effect is used to provide the required tunable polarization phase shifting. Calculated 40dB extinction ratio is shown in presence of fabrication errors that would yield a 4dB extinction ratio in the conventional approach.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂa Tech
Silicon-on-insulator polarization controller with relaxed fabrication tolerances
Polarization control is essential in applications ranging from optical
communications to interferometric sensors. The implementation of in-
tegrated polarization controllers is challenging as they require polariza-
tion rotating waveguides with stringent fabrication tolerances. Here, we
present a fully integrated polarization controller scheme that signi cantly
relaxes the requirements on the rotating waveguides, alleviating fabri-
cation tolerances. We analytically establish a technology-independent,
easily measurable tolerance condition for the rotating waveguides. Po-
larization control in the presence of waveguide width errors of 25% is
shown through full vectorial simulation.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂa Tech
Therapeutic recommendations in HFE hemochromatosis for p.Cys282Tyr (C282Y/C282Y) homozygous genotype
Although guidelines are available for hereditary hemochromatosis, a high percentage of the recommendations within them are not shared between the different guidelines. Our main aim is to provide an objective, simple, brief, and practical set of recommendations about therapeutic aspects of HFE hemochromatosis for p.Cys282Tyr (C282Y/C282Y) homozygous genotype, based on the published scientific studies and guidelines, in a form that is reasonably comprehensible to patients and people without medical training. This final version was approved at the Hemochromatosis International meeting on 12th May 2017 in Los Angeles
WIDER Advisory Group on International Economic Issues
(A research and training centre of the United Nations University
Bi-allelic Mutations in NDUFA6 Establish Its Role in Early-Onset Isolated Mitochondrial Complex I Deficiency.
Isolated complex I deficiency is a common biochemical phenotype observed in pediatric mitochondrial disease and often arises as a consequence of pathogenic variants affecting one of the âŒ65 genes encoding the complex I structural subunits or assembly factors. Such genetic heterogeneity means that application of next-generation sequencing technologies to undiagnosed cohorts has been a catalyst for genetic diagnosis and gene-disease associations. We describe the clinical and molecular genetic investigations of four unrelated children who presented with neuroradiological findings and/or elevated lactate levels, highly suggestive of an underlying mitochondrial diagnosis. Next-generation sequencing identified bi-allelic variants in NDUFA6, encoding a 15 kDa LYR-motif-containing complex I subunit that forms part of the Q-module. Functional investigations using subjects' fibroblast cell lines demonstrated complex I assembly defects, which were characterized in detail by mass-spectrometry-based complexome profiling. This confirmed a marked reduction in incorporated NDUFA6 and a concomitant reduction in other Q-module subunits, including NDUFAB1, NDUFA7, and NDUFA12. Lentiviral transduction of subjects' fibroblasts showed normalization of complex I. These data also support supercomplex formation, whereby the âŒ830 kDa complex I intermediate (consisting of the P- and Q-modules) is in complex with assembled complex III and IV holoenzymes despite lacking the N-module. Interestingly, RNA-sequencing data provided evidence that the consensus RefSeq accession number does not correspond to the predominant transcript in clinically relevant tissues, prompting revision of the NDUFA6 RefSeq transcript and highlighting not only the importance of thorough variant interpretation but also the assessment of appropriate transcripts for analysis
Labor And The Politics Of Structural Adjustment In Australia And Indonesia
The labour forces of Australia and Indonesia are compared for the period from the late 1960s to the 1990s. The position of labour in a global economy is also considered. It is determined that the outlook for organised labour is bleak, however its position is also contingent upon national circumstance
"Pretty sleek and fat" : the genesis of forest policy in British Columbia, 1903-1914
This study examines events surrounding the 1909-1910 Fulton Royal Commission to analyze the early management and exploitation of one provincial resource, timber. Since successive governments in British Columbia have sought to regulate this resource industry, it is desirable to have some understanding of the historical processes by which Crown policy and regulations have been decided upon. Furthermore, those government measures not only cover fields requiring a high level of -technical expertise and an intimate knowledge of the industry concerned, but have also shaped the very structure of those industries. By 1900 the principle of Crown ownership of the province's forest land was well established. Because of this principle, when in the early years of the twentieth centure the forest industry in British Columbia expanded greatly, the Crown was able to ensure that its forest income rose correspondingly. Changes in the terms of access to Crown timber were, in fact, aimed at increasing still further Crown forest revenues, especially after 1905. Having briefly discussed contemporary governmental policies and developments elsewhere on the continent, the thesis then examines the situation in British Columbia to 1909, and the reasons for the appointment of the Fulton Commission in that year. It is suggested that the Commission was set up at that juncture because, having achieved its primary aim of a substantial and steady flow of revenue from Crown forests, the McBride government was unsure of what other forestry goals to pursue. An exposition of themes recurrent at the hearings of the Fulton Commission is undertaken. Themes include security of tenure for those holding cutting-rights to timber on Crown land, conservation, reforestation and the regulation of logging practices, and the provision by the Crown of certain servicesâsuch as forest fire protectionâto the forest industry. It is argued that the way in which these themes were treated in the Final Report of the Commission was a reflection of the McBride government's overriding concern with maintaining its high flow of forest revenues. In this context it is noted that neither the Commission's Final Report of 1910, nor British Columbia's first Forest Act of 1912, were particularly innovative or unique in terms of contemporary continental practices. The main focus of government forest policy remained fiscal throughout this period, and indeed well beyond it.Arts, Faculty ofHistory, Department ofGraduat
- âŠ