89 research outputs found

    Defect Formation and Kinetics of Atomic Terrace Merging

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    Pairs of atomic scale terraces on a single crystal metal surface can be made to merge controllably under suitable conditions to yield steps of double height and width. We study the effect of various physical parameters on the formation of defects in a kinetic model of step doubling. We treat this manifestly non- equilibrium problem by mapping the model onto a 1-D random sequential adsorption problem and solving this analytically. We also do simulations to check the validity of our treatment. We find that our treatment effectively captures the dynamic evolution and the final state of the surface morphology. We show that the number and nature of the defects formed is controlled by a single dimensionless parameter qq. For qq close to one we show that the fraction of defects rises linearly with Ï”â‰Ą1−q\epsilon \equiv 1-q as 0.284Ă—Ï”0.284 \times \epsilon. We also show that one can arrive at the final state faster and with fewer defects by changing the parameter with time.Comment: 17 pages, 8 figures. To be submitted to Phys. Rev.

    Revisiting inclusion in smart cities: infrastructural hybridization and the institutionalization of citizen participation in Bengaluru’s peripheries

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    Smart city development can be traced back in the urban development trajectories of cities, as well as the respective articulations, framing and practices of ‘inclusive’ and ‘participatory’ smart cities. As smart city development steadily gains more and more traction among urban policy makers throughout the Global South, many scholars warn for its negative consequences on the accessibility of infrastructure and the processes that transform democratic citizenship practices. Rather than perceiving the transformative power of smart cities as a phenomenon particular to the use of new technologies, this paper aims to analyse societal segregation and marginalization through smart city development and traces these externalities as a continuation or intensification of existing governance practices. This is demonstrated by the case study on the metropolitan city of Bengaluru, that participates in India's national Smart City Mission. Due to massive urbanization, Bengaluru's peripheries are suffering from increasing pressures on its basic infrastructure. In response, state actors have turned to hybridizing the city's infrastructure facilities and governance to market- and civil society actors. Furthermore, the efforts of middle-class civil society groups that contribute to infrastructural governance through the assistance in planning, facilitation and controlling state responsibilities are institutionalized by bureaucratic state actors, at the cost of electoral governance by local representatives. This analysis on infrastructure governance in the peripheries has been set in relation to a discourse analysis of official policy documents on the inclusive and participatory character of smart cities. The practices of hybridization and institutionalization not only undermine the access to basic infrastructure for marginalized groups but also heavily underpin the design of Bengaluru's smart city projects. To be called inclusive, we argue that smart city projects should make an effort to improve the overall accessibilities of infrastructures for all classes and population groups

    "In a situation of rescuing life"

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    Background: Diabetes mellitus is an emerging public health problem in Tanzania. For the community and the health system to respond adequately to this problem, it is important that we understand the meanings given to its symptoms, and the care-seeking practices of individuals. Methods: To explore collective views on the meanings given to diabetes symptoms, we conducted nine focus group discussions with adult diabetes patients and members of the general community. To gain a better understanding of how the meanings in the community inform the care-seeking practices of individuals, 19 in-depth interviews were conducted with diabetes patients. The data were analyzed using principles of grounded theory and applying cultural schema theory as a deductive framework. Results: In the communities and among the patients, knowledge and awareness of diabetes are limited. Both people with diabetes and community members referred to their prevailing cultural meaning systems and schemas for infectious diseases to interpret and assign meaning to the emerging symptoms. Diabetes patients reported that they had initially used anti-malarial medicines because they believed their symptoms—like headache, fever, and tiredness—were suggestive of malaria. Schemas for body image informed the meaning given to diabetes symptoms similar to those of HIV, like severe weight loss. Confusion among members of the community about the diabetes symptoms instigated tension, causing patients to be mistrusted and stigmatized. The process of meaning-giving and the diagnosis of the diabetes symptoms was challenging for both patients and health care professionals. Diabetes patients reported being initially misdiagnosed and treated for other conditions by medical professionals. The inability to assign meaning to the symptoms and determine their etiologies informed the decision made by some patients to consult traditional healers, and to associate their symptoms with witchcraft causes. Conclusion: The meanings given to diabetes symptoms and the care-seeking practices described in the study are shaped by the prevailing cultural schemas for infectious diseases and their treatments. Efforts to educate people about the symptoms of diabetes and to encourage them to seek out appropriate care should build on the prevailing cultural meaning system and schemas for diseases, health and illness

    Animal model integration to AutDB, a genetic database for autism

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    <p>Abstract</p> <p>Background</p> <p>In the post-genomic era, multi-faceted research on complex disorders such as autism has generated diverse types of molecular information related to its pathogenesis. The rapid accumulation of putative candidate genes/loci for Autism Spectrum Disorders (ASD) and ASD-related animal models poses a major challenge for systematic analysis of their content. We previously created the Autism Database (AutDB) to provide a publicly available web portal for ongoing collection, manual annotation, and visualization of genes linked to ASD. Here, we describe the design, development, and integration of a new module within AutDB for ongoing collection and comprehensive cataloguing of ASD-related animal models.</p> <p>Description</p> <p>As with the original AutDB, all data is extracted from published, peer-reviewed scientific literature. Animal models are annotated with a new standardized vocabulary of phenotypic terms developed by our researchers which is designed to reflect the diverse clinical manifestations of ASD. The new Animal Model module is seamlessly integrated to AutDB for dissemination of diverse information related to ASD. Animal model entries within the new module are linked to corresponding candidate genes in the original "Human Gene" module of the resource, thereby allowing for cross-modal navigation between gene models and human gene studies. Although the current release of the Animal Model module is restricted to mouse models, it was designed with an expandable framework which can easily incorporate additional species and non-genetic etiological models of autism in the future.</p> <p>Conclusions</p> <p>Importantly, this modular ASD database provides a platform from which data mining, bioinformatics, and/or computational biology strategies may be adopted to develop predictive disease models that may offer further insights into the molecular underpinnings of this disorder. It also serves as a general model for disease-driven databases curating phenotypic characteristics of corresponding animal models.</p

    Intercomparison of Small Unmanned Aircraft System (sUAS) Measurements for Atmospheric Science During the LAPSE-RATE Campaign

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    Small unmanned aircraft systems (sUAS) are rapidly transforming atmospheric research. With the advancement of the development and application of these systems, improving knowledge of best practices for accurate measurement is critical for achieving scientific goals. We present results from an intercomparison of atmospheric measurement data from the Lower Atmospheric Process Studies at Elevation—a Remotely piloted Aircraft Team Experiment (LAPSE-RATE) field campaign. We evaluate a total of 38 individual sUAS with 23 unique sensor and platform configurations using a meteorological tower for reference measurements. We assess precision, bias, and time response of sUAS measurements of temperature, humidity, pressure, wind speed, and wind direction. Most sUAS measurements show broad agreement with the reference, particularly temperature and wind speed, with mean value differences of 1.6 ± 2.6 °C and 0.22 ± 0.59 m/s for all sUAS, respectively. sUAS platform and sensor configurations were found to contribute significantly to measurement accuracy. Sensor configurations, which included proper aspiration and radiation shielding of sensors, were found to provide the most accurate thermodynamic measurements (temperature and relative humidity), whereas sonic anemometers on multirotor platforms provided the most accurate wind measurements (horizontal speed and direction). We contribute both a characterization and assessment of sUAS for measuring atmospheric parameters, and identify important challenges and opportunities for improving scientific measurements with sUAS

    Benefits for children with suspected cancer from routine whole-genome sequencing

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    Clinical whole-genome sequencing (WGS) has been shown to deliver potential benefits to children with cancer and to alter treatment in high-risk patient groups. It remains unknown whether offering WGS to every child with suspected cancer can change patient management. We collected WGS variant calls and clinical and diagnostic information from 281 children (282 tumors) across two English units (n = 152 from a hematology center, n = 130 from a solid tumor center) where WGS had become a routine test. Our key finding was that variants uniquely attributable to WGS changed the management in ~7% (20 out of 282) of cases while providing additional disease-relevant findings, beyond standard-of-care molecular tests, in 108 instances for 83 (29%) cases. Furthermore, WGS faithfully reproduced every standard-of-care molecular test (n = 738) and revealed several previously unknown genomic features of childhood tumors. We show that WGS can be delivered as part of routine clinical care to children with suspected cancer and can change clinical management by delivering unexpected genomic insights. Our experience portrays WGS as a clinically impactful assay for routine practice, providing opportunities for assay consolidation and for delivery of molecularly informed patient care.</p

    Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

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    Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
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