13,200 research outputs found

    An Approach to Simultaneously Test Multiple Devices for High-Throughput Production of Thin-Film Electronics

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    New generation of thin-film transistors (TFTs), where the active material is amorphous oxide, conjugated polymer, or small molecules, have the advantage of flexibility, high form factor, and large scale manufacturability through low cost processing techniques, e.g., roll-to-roll printing, screen printing. During high-throughput production using these techniques, the probability of defects being present increases with the speed of manufacturing and area of devices. Therefore a high-throughput and low cost testing technique is absolute essential to maintain high quality of final product. We report a Simultaneous Multiple Device Testing (SMuDT) approach which is up to 10 times faster and cost effective than conventional testing methods. The SMuDT approach was validated using circuit simulation and demonstrated by testing large scale indium gallium zinc oxide (IGZO) TFTs. A method to ‘bin’ the tested devices using Figure of Merit was established.The authors acknowledge the support of this project provided by the EPSRC and Innovate UK through the AUTOFLEX Project (grant no. EP/L505201/1) and CIMLAE Project (EP/K03099X/1). AK and AJF would like to thank PragmatIC Printing Ltd. for wafer samples. Additional data related to this publication which is not of a commercially sensitive nature is available at the DSpace@Cambridge data repository (www.repository.cam.ac.uk).This is the final version of the article. It first appeared from IEEE via http://dx.doi.org/10.1109/JDT.2015.246229

    On the weakening of Hurricane Lili, October 2002

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    This paper addresses the weakening of Hurricane Lili of October 2002 just before it made landfall in Louisiana. This hurricane weakened from a category 4 storm on October 3, 2002 at 0000 UTC to a category 1 storm on October 3, 2002 at 1300 UTC. This sudden drop in intensity has been a subject of considerable interest. In this paper we explore a forecast model diagnostic approach that explores the contribution to the hurricane intensity changes arising from a number of dynamical and physical possibilities. Running several versions of a global model at very high resolution, the relative contribution to the intensity drop of Lili arising from cooler sea surface temperatures, dry air advection into the storm, advective non-linear dynamics, non-advective dynamics, and shallow and deep cumulus convection was examined. This line of inquiry led to the conclusion that dry air advection from the north into the storm and the slightly cold sea surface temperatures were not the primary contribution to the observed pressure rise by 22 hPa. The primary contribution to the pressure rise was found to be the 'rest of dynamics' (the non-advective dynamics). The shallow convection contributed slightly to an overall cooling, i.e. a weakening of the warm core of Lili. The effects of deep cumulus convection appeared to be opposite, i.e. towards maintaining a strong storm. A primary term in the 'rest of dynamics', the advection of Earth's angular momentum into the storm, is identified as a major contributor for the intensity change in the analysis. This feature resembles an intrusion of dry air into the core of the storm. This intrusion contributes to a reduction of spin and an overall rapid weakening of the hurricane. The angular momentum partitioning appears quite revealing on the sudden demise of Lili

    Phylogeography of Japanese encephalitis virus:genotype is associated with climate

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    The circulation of vector-borne zoonotic viruses is largely determined by the overlap in the geographical distributions of virus-competent vectors and reservoir hosts. What is less clear are the factors influencing the distribution of virus-specific lineages. Japanese encephalitis virus (JEV) is the most important etiologic agent of epidemic encephalitis worldwide, and is primarily maintained between vertebrate reservoir hosts (avian and swine) and culicine mosquitoes. There are five genotypes of JEV: GI-V. In recent years, GI has displaced GIII as the dominant JEV genotype and GV has re-emerged after almost 60 years of undetected virus circulation. JEV is found throughout most of Asia, extending from maritime Siberia in the north to Australia in the south, and as far as Pakistan to the west and Saipan to the east. Transmission of JEV in temperate zones is epidemic with the majority of cases occurring in summer months, while transmission in tropical zones is endemic and occurs year-round at lower rates. To test the hypothesis that viruses circulating in these two geographical zones are genetically distinct, we applied Bayesian phylogeographic, categorical data analysis and phylogeny-trait association test techniques to the largest JEV dataset compiled to date, representing the envelope (E) gene of 487 isolates collected from 12 countries over 75 years. We demonstrated that GIII and the recently emerged GI-b are temperate genotypes likely maintained year-round in northern latitudes, while GI-a and GII are tropical genotypes likely maintained primarily through mosquito-avian and mosquito-swine transmission cycles. This study represents a new paradigm directly linking viral molecular evolution and climate

    A fourth generation, anomalous like-sign dimuon charge asymmetry and the LHC

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    A fourth chiral generation, with mtm_{t^\prime} in the range (300500)\sim (300 - 500) GeV and a moderate value of the CP-violating phase can explain the anomalous like-sign dimuon charge asymmetry observed recently by the D0 collaboration. The required parameters are found to be consistent with constraints from other BB and KK decays. The presence of such quarks, apart from being detectable in the early stages of the LHC, would also have important consequences in the electroweak symmetry breaking sector.Comment: 18 pages, 9 figures, Figure 1 is modified, more discussions are added in section 2. new references adde

    Effect of increased ART-CPT uptake on tuberculosis outcomes and associated factors, Burundi, 2009-2013.

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    We retrospectively examined 3579 records of human immunodeficiency virus infected tuberculosis (TB) patients diagnosed from January 2009 to June 2013 in 55 TB treatment facilities in Burundi, to demonstrate whether improvement of combined cotrimoxazole preventive therapy and antiretroviral therapy (ART) uptake was accompanied by improvement of treatment outcomes, and to describe associated factors. Treatment success rates increased from 71% to 80% (P < 0.001). While loss to follow-up and transfer-out rates declined significantly, death rates decreased modestly, and remained high, at 14%. ART uptake was worse in suburban areas and private for-profit institutions. World Health Organization targets could be achieved if peripheral health facilities were prioritised

    Should physical activity recommendations be ethnicity-specific? Evidence from a cross-sectional study of south Asian and European men

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    Background Expert bodies and health organisations recommend that adults undertake at least 150 min.week−1 of moderate-intensity physical activity (MPA). However, the underpinning data largely emanate from studies of populations of European descent. It is unclear whether this level of activity is appropriate for other ethnic groups, particularly South Asians, who have increased cardio-metabolic disease risk compared to Europeans. The aim of this study was to explore the level of MPA required in South Asians to confer a similar cardio-metabolic risk profile to that observed in Europeans undertaking the currently recommended MPA level of 150 min.week−1.&lt;p&gt;&lt;/p&gt; Methods Seventy-five South Asian and 83 European men, aged 40–70, without cardiovascular disease or diabetes had fasted blood taken, blood pressure measured, physical activity assessed objectively (using accelerometry), and anthropometric measures made. Factor analysis was used to summarise measured risk biomarkers into underlying latent ‘factors’ for glycaemia, insulin resistance, lipid metabolism, blood pressure, and overall cardio-metabolic risk. Age-adjusted regression models were used to determine the equivalent level of MPA (in bouts of ≥10 minutes) in South Asians needed to elicit the same value in each factor as Europeans undertaking 150 min.week−1 MPA.&lt;p&gt;&lt;/p&gt; Findings For all factors, except blood pressure, equivalent MPA values in South Asians were significantly higher than 150 min.week−1; the equivalent MPA value for the overall cardio-metabolic risk factor was 266 (95% CI 185-347) min.week−1.&lt;p&gt;&lt;/p&gt; Conclusions South Asian men may need to undertake greater levels of MPA than Europeans to exhibit a similar cardio-metabolic risk profile, suggesting that a conceptual case can be made for ethnicity-specific physical activity guidance. Further study is needed to extend these findings to women and to replicate them prospectively in a larger cohort.&lt;p&gt;&lt;/p&gt

    Geometric Mixing, Peristalsis, and the Geometric Phase of the Stomach

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    Mixing fluid in a container at low Reynolds number - in an inertialess environment - is not a trivial task. Reciprocating motions merely lead to cycles of mixing and unmixing, so continuous rotation, as used in many technological applications, would appear to be necessary. However, there is another solution: movement of the walls in a cyclical fashion to introduce a geometric phase. We show using journal-bearing flow as a model that such geometric mixing is a general tool for using deformable boundaries that return to the same position to mix fluid at low Reynolds number. We then simulate a biological example: we show that mixing in the stomach functions because of the "belly phase": peristaltic movement of the walls in a cyclical fashion introduces a geometric phase that avoids unmixing.Comment: Revised, published versio

    Dense active matter model of motion patterns in confluent cell monolayers

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    Epithelial cell monolayers show remarkable displacement and velocity correlations over distances of ten or more cell sizes that are reminiscent of supercooled liquids and active nematics. We show that many observed features can be described within the framework of dense active matter, and argue that persistent uncoordinated cell motility coupled to the collective elastic modes of the cell sheet is sufficient to produce swirl-like correlations. We obtain this result using both continuum active linear elasticity and a normal modes formalism, and validate analytical predictions with numerical simulations of two agent-based cell models, soft elastic particles and the self-propelled Voronoi model together with in-vitro experiments of confluent corneal epithelial cell sheets. Simulations and normal mode analysis perfectly match when tissue-level reorganisation occurs on times longer than the persistence time of cell motility. Our analytical model quantitatively matches measured velocity correlation functions over more than a decade with a single fitting parameter.Comment: updated version accepted for publication in Nat. Com

    Anomaly Cancelation in Field Theory and F-theory on a Circle

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    We study the manifestation of local gauge anomalies of four- and six-dimensional field theories in the lower-dimensional Kaluza-Klein theory obtained after circle compactification. We identify a convenient set of transformations acting on the whole tower of massless and massive states and investigate their action on the low-energy effective theories in the Coulomb branch. The maps employ higher-dimensional large gauge transformations and precisely yield the anomaly cancelation conditions when acting on the one-loop induced Chern-Simons terms in the three- and five-dimensional effective theory. The arising symmetries are argued to play a key role in the study of the M-theory to F-theory limit on Calabi-Yau manifolds. For example, using the fact that all fully resolved F-theory geometries inducing multiple Abelian gauge groups or non-Abelian groups admit a certain set of symmetries, we are able to generally show the cancelation of pure Abelian or pure non-Abelian anomalies in these models.Comment: 48 pages, 2 figures; v2: typos corrected, comments on circle fluxes adde

    Insecticide resistance and the future of malaria control in Zambia.

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    BACKGROUND: In line with the Global trend to improve malaria control efforts a major campaign of insecticide treated net distribution was initiated in 1999 and indoor residual spraying with DDT or pyrethroids was reintroduced in 2000 in Zambia. In 2006, these efforts were strengthened by the President's Malaria Initiative. This manuscript reports on the monitoring and evaluation of these activities and the potential impact of emerging insecticide resistance on disease transmission. METHODS: Mosquitoes were captured daily through a series of 108 window exit traps located at 18 sentinel sites. Specimens were identified to species and analyzed for sporozoites. Adult Anopheles mosquitoes were collected resting indoors and larva collected in breeding sites were reared to F1 and F0 generations in the lab and tested for insecticide resistance following the standard WHO susceptibility assay protocol. Annual cross sectional household parasite surveys were carried out to monitor the impact of the control programme on prevalence of Plasmodium falciparum in children aged 1 to 14 years. RESULTS: A total of 619 Anopheles gambiae s.l. and 228 Anopheles funestus s.l. were captured from window exit traps throughout the period, of which 203 were An. gambiae malaria vectors and 14 An. funestus s.s.. In 2010 resistance to DDT and the pyrethroids deltamethrin, lambda-cyhalothrin and permethrin was detected in both An. gambiae s.s. and An. funestus s.s.. No sporozoites were detected in either species. Prevalence of P. falciparum in the sentinel sites remained below 10% throughout the study period. CONCLUSION: Both An. gambiae s.s. and An. funestus s.s. were controlled effectively with the ITN and IRS programme in Zambia, maintaining a reduced disease transmission and burden. However, the discovery of DDT and pyrethroid resistance in the country threatens the sustainability of the vector control programme
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