334 research outputs found

    Neighbour transitivity on codes in Hamming graphs

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    We consider a \emph{code} to be a subset of the vertex set of a \emph{Hamming graph}. In this setting a \emph{neighbour} of the code is a vertex which differs in exactly one entry from some codeword. This paper examines codes with the property that some group of automorphisms acts transitively on the \emph{set of neighbours} of the code. We call these codes \emph{neighbour transitive}. We obtain sufficient conditions for a neighbour transitive group to fix the code setwise. Moreover, we construct an infinite family of neighbour transitive codes, with \emph{minimum distance} δ=4\delta=4, where this is not the case. That is to say, knowledge of even the complete set of code neighbours does not determine the code

    High‐Performance Zinc Tin Oxide TFTs with Active Layers Deposited by Atomic Layer Deposition

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    New deposition techniques for amorphous oxide semiconductors compatible with silicon back end of line manufacturing are needed for 3D monolithic integration of thin‐film electronics. Here, three atomic layer deposition (ALD) processes are compared for the fabrication of amorphous zinc tin oxide (ZTO) channels in bottom‐gate, top‐contact n‐channel transistors. As‐deposited ZTO films, made by ALD at 150–200 °C, exhibit semiconducting, enhancement‐mode behavior with electron mobility as high as 13 cm2 V−1 s−1, due to a low density of oxygen‐related defects. ZTO deposited at 200 °C using a hybrid thermal‐plasma ALD process with an optimal tin composition of 21%, post‐annealed at 400 °C, shows excellent performance with a record high mobility of 22.1 cm2 V–1 s–1 and a subthreshold slope of 0.29 V dec–1. Increasing the deposition temperature and performing post‐deposition anneals at 300–500 °C lead to an increased density of the X‐ray amorphous ZTO film, improving its electrical properties. By optimizing the ZTO active layer thickness and using a high‐k gate insulator (ALD Al2O3), the transistor switching voltage is lowered, enabling electrical compatibility with silicon integrated circuits. This work opens the possibility of monolithic integration of ALD ZTO‐based thin‐film electronics with silicon integrated circuits or onto large‐area flexible substrates.Three atomic layer deposition (ALD) processes are investigated for the deposition of zinc tin oxide (ZTO) as the active layer in thin‐film transistors (TFTs). With a low density of oxygen vacancies, as‐deposited films exhibit semiconducting, enhancement‐mode behavior. Post‐deposition anneals result in increased film density and record high electron mobility for ALD ZTO TFTs using process temperatures within the back‐end‐of‐line thermal budget.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156226/3/aelm202000195-sup-0001-SuppMat.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156226/2/aelm202000195.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156226/1/aelm202000195_am.pd

    Biofortification of UK food crops with selenium

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    Se is an essential element for animals. In man low dietary Se intakes are associated with health disorders including oxidative stress-related conditions, reduced fertility and immune functions and an increased risk of cancers. Although the reference nutrient intakes for adult females and males in the UK are 60 and 75 Îźg Se/d respectively, dietary Se intakes in the UK have declined from >60 Îźg Se/d in the 1970s to 35 Îźg Se/d in the 1990s, with a concomitant decline in human Se status. This decline in Se intake and status has been attributed primarily to the replacement of milling wheat having high levels of grain Se and grown on high-Se soils in North America with UK-sourced wheat having low levels of grain Se and grown on low-Se soils. An immediate solution to low dietary Se intake and status is to enrich UK-grown food crops using Se fertilisers (agronomic biofortification). Such a strategy has been adopted with success in Finland. It may also be possible to enrich food crops in the longer term by selecting or breeding crop varieties with enhanced Se-accumulation characteristics (genetic biofortification). The present paper will review the potential for biofortification of UK food crops with Se

    Physical Activity Promotion in the Evolving Work Landscape

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    How and where we do our work is changing in the United States across industry, government, and non-profit sectors. This evolving landscape includes downsized office space, the reduction of corporate fitness centers, decreased daily commutes, increased hybrid or remote work environments, and experiments with the length of the work week. While some of these changes may prove transient, others will likely be permanent changes affecting the context of work. Some occupations require in-person work settings, especially in the health care, education, travel and food processing sectors. Many of these employees are experiencing burnout after prolonged overtime work and stressful pandemic-related work conditions. Accordingly, employers are turning their focus to employee health and well-being; productivity, retention, promotion; diversity, equity, and inclusion; re-thinking their corporate wellness programs; and prioritizing financial stability, work-life balance, mental health, and other health-promoting culture, systems and policy changes

    Effects of Changing Work Environments on Employer Support for Physical Activity During COVID-19

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    COVID-19 dramatically accelerated evolving changes in the way we define the “work environment” in the United States. In response to COVID-19, many employers have offered increased flexibility for where employees work, including remote (an employee’s workstation is at home) and hybrid work (an employee works both at the employer worksite and remotely, on predetermined schedules). Accordingly, worksite physical activity (PA) and sedentary behaviors (SB) such as extended sitting time (ST) may have changed.1,2 However, little is known about whether these work arrangements are associated with changes in employer support for PA. Interviews were conducted to assess this gap in understanding. Because little is known about employer support for equity with respect to PA and SB, this study sought to identify potential strategies to assure equity in PA opportunities across work environments

    Darwin Core: An Evolving Community-Developed Biodiversity Data Standard

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    Biodiversity data derive from myriad sources stored in various formats on many distinct hardware and software platforms. An essential step towards understanding global patterns of biodiversity is to provide a standardized view of these heterogeneous data sources to improve interoperability. Fundamental to this advance are definitions of common terms. This paper describes the evolution and development of Darwin Core, a data standard for publishing and integrating biodiversity information. We focus on the categories of terms that define the standard, differences between simple and relational Darwin Core, how the standard has been implemented, and the community processes that are essential for maintenance and growth of the standard. We present case-study extensions of the Darwin Core into new research communities, including metagenomics and genetic resources. We close by showing how Darwin Core records are integrated to create new knowledge products documenting species distributions and changes due to environmental perturbations
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