192 research outputs found

    A Fully-Integrated Quad-Band GSM/GPRS CMOS Power Amplifier

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    Concentric distributed active transformers (DAT) are used to implement a fully-integrated quad-band power amplifier (PA) in a standard 130 nm CMOS process. The DAT enables the power amplifier to integrate the input and output matching networks on the same silicon die. The PA integrates on-chip closed-loop power control and operates under supply voltages from 2.9 V to 5.5 V in a standard micro-lead-frame package. It shows no oscillations, degradation, or failures for over 2000 hours of operation with a supply of 6 V at 135° under a VSWR of 15:1 at all phase angles and has also been tested for more than 2 million device-hours (with ongoing reliability monitoring) without a single failure under nominal operation conditions. It produces up to +35 dBm of RF power with power-added efficiency of 51%

    Climate Change and Canadian Unions: The Dilemma for Labour

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    In 2010, a group of Canadian trade unions, labour academics and environmental groups began a five year funded community-university research project, Work in a Warming World (W3), to develop effective ways for labour to take leadership in the struggle to slow global warming. We stated the problem this way: How can labour broaden and deepen its capacity to protect work and workers from the unique threats posed by climate change, all the while contributing to the struggle to slow global warming within the context of increasingly pessimistic climate science, global economic crisis, a hostile national government and strategic paralysis in the national and international political arena? The authors explore the challenges and dilemmas for labour leadership in relation to environmental responsibility in the current political climate in Canada, drawing on W3 research and the unexpected uses that research can be put to, using the case of the Canadian Union of Postal workers in catalyzing and internationalising activist engagement for climate bargaining.Work in a Warming World (W3

    Budget 2017: experts respond

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    First paragraph: The UK chancellor of the exchequer, Philip Hammond, has delivered a budget which offered help to first-time home buyers and the prospect of more money for workers in the National Health Service, but his speech was partly overshadowed by sharpcuts to GDP growth forecastsfrom the Office of Budget Responsibility (OBR). Our team of academics deliver their verdict on the measures introduced and opportunities missed

    Superposition as a logical glue

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    The typical mathematical language systematically exploits notational and logical abuses whose resolution requires not just the knowledge of domain specific notation and conventions, but not trivial skills in the given mathematical discipline. A large part of this background knowledge is expressed in form of equalities and isomorphisms, allowing mathematicians to freely move between different incarnations of the same entity without even mentioning the transformation. Providing ITP-systems with similar capabilities seems to be a major way to improve their intelligence, and to ease the communication between the user and the machine. The present paper discusses our experience of integration of a superposition calculus within the Matita interactive prover, providing in particular a very flexible, "smart" application tactic, and a simple, innovative approach to automation.Comment: In Proceedings TYPES 2009, arXiv:1103.311

    An Optically Dark GRB Observed by HETE-2: GRB 051022

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    GRB 051022 was detected at 13:07:58 on 22 October 2005 by HETE-2. The location of GRB 051022 was determined immediately by the flight localization system. This burst contains multiple pulses and has a rather long duration of about 190 seconds. The detections of candidate X-ray and radio afterglows were reported, whereas no optical afterglow was found. The optical spectroscopic observations of the host galaxy revealed the redshift z = 0.8. Using the data derived by HETE-2 observation of the prompt emission, we found the absorption N_H = 8.8 -2.9/+3.1 x 10^22 cm^-2 and the visual extinction A_V = 49 -16/+17 mag in the host galaxy. If this is the case, no detection of any optical transient would be quite reasonable. The absorption derived by the Swift XRT observations of the afterglow is fully consistent with those obtained from the early HETE-2 observation of the prompt emission. Our analysis implies an interpretation that the absorbing medium could be outside external shock at R ~ 10^16 cm, which may be a dusty molecular cloud.Comment: 6 pages, 2 figures, accepted for publication in PASJ lette

    Atmospheric Acetaldehyde: Importance of Air-Sea Exchange and a Missing Source in the Remote Troposphere.

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    We report airborne measurements of acetaldehyde (CH3CHO) during the first and second deployments of the National Aeronautics and Space Administration (NASA) Atmospheric Tomography Mission (ATom). The budget of CH3CHO is examined using the Community Atmospheric Model with chemistry (CAM-chem), with a newly-developed online air-sea exchange module. The upper limit of the global ocean net emission of CH3CHO is estimated to be 34 Tg a-1 (42 Tg a-1 if considering bubble-mediated transfer), and the ocean impacts on tropospheric CH3CHO are mostly confined to the marine boundary layer. Our analysis suggests that there is an unaccounted CH3CHO source in the remote troposphere and that organic aerosols can only provide a fraction of this missing source. We propose that peroxyacetic acid (PAA) is an ideal indicator of the rapid CH3CHO production in the remote troposphere. The higher-than-expected CH3CHO measurements represent a missing sink of hydroxyl radicals (and halogen radical) in current chemistry-climate models

    Suboptimal SVR rates in African patients with atypical genotype 1 subtypes: Implications for global elimination of hepatitis C.

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    BACKGROUND & AIMS: HCV subtypes which are unusual in Europe are more prevalent in the African region, but little is known of their response to direct-acting antivirals (DAAs). These include non-1a/1b/ non-subtypeable genotype 1 (G1) or non-4a/4d (G4). In this report we aimed to describe the genotype distribution and treatment outcome in a south London cohort of African patients. METHODS: We identified all patients born in Africa who attended our clinic from 2010-2018. Information on HCV genotype, treatment regimen and outcome were obtained. Non-subtypeable samples were analysed using Glasgow NimbleGen next-generation sequencing (NGS). Phylogenetic analysis was carried out by generating an uncorrected nucleotide p-distance tree from the complete coding regions of our sequences. RESULTS: Of 91 African patients, 47 (52%) were infected with an unusual subtype. Fourteen novel, as yet undesignated subtypes (G1*), were identified by NGS. Three individuals were infected with the same subtype, now designated as subtype 1p. Baseline sequences were available for 22 patients; 18/22 (82%) had baseline NS5A resistance-associated substitutions (RASs). Sustained virological response (SVR) was achieved in 56/63 (89%) overall, yet only in 21/28 (75%) of those with unusual G1 subtypes, with failure in 3/16 G1*, 1/2 G1p and 3/3 in G1l. Six treatment failures occurred with sofosbuvir/ledipasvir compared to 1 failure on a PI-based regimen. The SVR rate for all other genotypes and subtypes was 35/35 (100%). CONCLUSIONS: Most individuals in an unselected cohort of African patients were infected with an unusual genotype, including novel subtype 1p. The SVR rate of those with unusual G1 subtypes was 75%, raising concern about expansion of DAAs across Africa. Depending on the regimen used, higher failure rates in African cohorts could jeopardise HCV elimination. LAY SUMMARY: Direct-acting antiviral medications are able to cure hepatitis C in the majority of patients. The most common genotype of hepatitis C in Europe and the United States is genotype 1a or 1b and most clinical trials focused on these genotypes. We report that in a group of African patients, most of them had unusual (non-1a/1b) genotype 1 subtypes, and that the cure rate in these unusual genotypes was lower than in genotypes 1a and 1b

    The role of role theory in International Political Economy

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    This article demonstrates the benefits of using a role theory approach in the field of International Political Economy (IPE) by demonstrating the benefits of role theory relative to variants of the social constructivist paradigm, especially vis-à-vis identity based accounts of IPE. This article also documents why and how role theory has always had a home in IPE even before the constructivist revolution in the 1990s. The social interactionist dimension in the work of Herbert Mead and his notion of a general other are linked to the relational ideas of friendship and impartial spectator present in the works of the founding father of classical political economy, Adam Smith. These similar ideas about the self and their surrounding social environment is a useful starting point to locate role theory in IPE and demonstrate its analytical advantages within social constructivism. After showing the “forgotten” place role theory has always had in IPE, the article illustrates the potential of using a role theory approach within the field of IPE through an illustrative analysis of the Greek economic crisis

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
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