58 research outputs found

    Measurement of Radio-Frequency Radiation Pressure

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    We perform measurements of the radiation pressure of a radio-frequency (RF) electromagnetic field which may lead to a new SI-traceable power calibration. There are several groups around the world investigating methods to perform more direct SI traceable measurement of RF power (where RF is defined to range from 100s of MHz to THz). A measurement of radiation pressure offers the possibility for a power measure traceable to the kilogram and to Planck's constant through the redefined SI. Towards this goal, we demonstrate the ability to measure the radiation pressure/force carried in a field at 15~GHz.Comment: 2 pages 4 figure

    Turbulent drag reduction by spanwise wall forcing. Part 2: High-Reynolds-number experiments

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    Here, we present measurements of turbulent drag reduction at high friction Reynolds numbers in the range of 4500Reτ150004500 \le Re_\tau \le 15000. The efficacy of the approach, using streamwise travelling waves of spanwise wall oscillations, is studied for two actuation regimes: (i) inner-scaled actuation (ISA), as investigated in Part 1 of this study, which targets the relatively high-frequency structures of the near-wall cycle, and (ii) outer-scaled actuation (OSA), which was recently presented by Marusic et al. (Nat. Commun., vol. 12, 2021) for high-ReτRe_\tau flows, targeting the lower-frequency, outer-scale motions. Multiple experimental techniques were used, including a floating-element balance to directly measure the skin-friction drag force, hot-wire anemometry to acquire long-time fluctuating velocity and wall-shear stress, and stereoscopic-PIV (particle image velocimetry) to measure the turbulence statistics of all three velocity components across the boundary layer. Under the ISA pathway, drag reduction of up to 25% was achieved, but mostly with net power saving losses due to the high-input power cost associated with the high-frequency actuation. The low-frequency OSA pathway, however, with its lower input power requirements, was found to consistently result in positive net power savings of 5 - 10%, for moderate drag reductions of 5 - 15%. The results suggest that OSA is an attractive pathway for energy-efficient drag reduction in high Reynolds number applications. Both ISA and OSA strategies are found to produce complex inter-scale interactions, leading to attenuation of the turbulent fluctuations across the boundary layer for a broad range of length and time scales

    Τεχνικές Σχολές και εργαστήρια στα Ιωάννινα

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    Data on incidence of resistance to phosphine over the last 20 years and factors associated with insect sample collection are stored in the Australian Grain Insect Resistance Database. The database was analysed using descriptive statistics, linear trend analysis and Bayesian hurdle modelling to gain insights into factors contributing to the development of strong resistance in Rhyzopertha dominica. Descriptive statistics indicated that strong resistance was significantly more common in central storages, particularly bunker storages, than on farms. Strong resistance in R. dominica was also associated with wheat, barley and sorghum but there was no significant link to any grain protectant or storage treatment chemical, other than phosphine. Highest frequency of strong resistance was found in northern New South Wales and no detections were made in Western Australia. In eastern Australia, trend analysis indicated that strong resistance detections increased steadily from the first detection in 1997 to about 8% of samples containing resistant insects in 2014. Weak resistance was detected in about 10% of samples in eastern Australia in the early 1990s but this increased rapidly to 40–50% by 1990, at the same time that industry use of phosphine greatly increased, and then to about 80% in 1995. Strong resistance was first detected in this species when weak resistance was diagnosed in close to 80% of population samples. The Bayesian hurdle model identified bunkers, silos and unsealed storages as being associated with development of strong resistance and sheds with a lower frequency. This model also identified an accelerated increase in resistance frequency of strong resistance from 2011 to present. The information gained from this analysis is being used to inform current and future management of resistance to phosphine

    Swift: primary data analysis for the Illumina Solexa sequencing platform

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    Motivation: Primary data analysis methods are of critical importance in second generation DNA sequencing. Improved methods have the potential to increase yield and reduce the error rates. Openly documented analysis tools enable the user to understand the primary data, this is important for the optimization and validity of their scientific work

    UK Kidney association clinical practice guideline: sodium-glucose co-transporter-2 (SGLT-2) inhibition in adults with kidney disease 2023 UPDATE

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    Large placebo-controlled trials have demonstrated kidney and cardiovascular clinical benefits of SGLT-2 inhibitors. Data from the EMPA-KIDNEY and DELIVER trials and associated meta-analyses triggered an update to the UK Kidney Association Clinical Practice Guideline on Sodium-Glucose Co-transporter-2 (SGLT-2) Inhibition in Adults with Kidney Disease. We provide a summary of the full guideline and highlight the rationale for recent updates. The use of SGLT-2 inhibitors in people with specific medical conditions, including type 1 diabetes, kidney transplants, and people admitted to hospital with heart failure is also considered, along with Recommendations for future research and Recommendations for implementation. A full “lay” summary of the guidelines is provided as an appendix to ensure that these guidelines are accessible and understandable to people who are not medical professionals

    A Pregnancy and Childhood Epigenetics Consortium (PACE) meta-analysis highlights potential relationships between birth order and neonatal blood DNA methylation

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    Higher birth order is associated with altered risk of many disease states. Changes in placentation and exposures to in utero growth factors with successive pregnancies may impact later life disease risk via persistent DNA methylation alterations. We investigated birth order with Illumina DNA methylation array data in each of 16 birth cohorts (8164 newborns) with European, African, and Latino ancestries from the Pregnancy and Childhood Epigenetics Consortium. Meta-analyzed data demonstrated systematic DNA methylation variation in 341 CpGs (FDR adjusted P &lt; 0.05) and 1107 regions. Forty CpGs were located within known quantitative trait loci for gene expression traits in blood, and trait enrichment analysis suggested a strong association with immune-related, transcriptional control, and blood pressure regulation phenotypes. Decreasing fertility rates worldwide with the concomitant increased proportion of first-born children highlights a potential reflection of birth order-related epigenomic states on changing disease incidence trends.</p

    A Pregnancy and Childhood Epigenetics Consortium (PACE) meta-analysis highlights potential relationships between birth order and neonatal blood DNA methylation

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    Higher birth order is associated with altered risk of many disease states. Changes in placentation and exposures to in utero growth factors with successive pregnancies may impact later life disease risk via persistent DNA methylation alterations. We investigated birth order with Illumina DNA methylation array data in each of 16 birth cohorts (8164 newborns) with European, African, and Latino ancestries from the Pregnancy and Childhood Epigenetics Consortium. Meta-analyzed data demonstrated systematic DNA methylation variation in 341 CpGs (FDR adjusted P &lt; 0.05) and 1107 regions. Forty CpGs were located within known quantitative trait loci for gene expression traits in blood, and trait enrichment analysis suggested a strong association with immune-related, transcriptional control, and blood pressure regulation phenotypes. Decreasing fertility rates worldwide with the concomitant increased proportion of first-born children highlights a potential reflection of birth order-related epigenomic states on changing disease incidence trends.</p

    Genome-wide analyses reveal a potential role for the MAPT, MOBP, and APOE loci in sporadic frontotemporal dementia

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    Frontotemporal dementia (FTD) is the second most common cause of early-onset dementia after Alzheimer disease (AD). Efforts in the field mainly focus on familial forms of disease (fFTDs), while studies of the genetic etiology of sporadic FTD (sFTD) have been less common. In the current work, we analyzed 4,685 sFTD cases and 15,308 controls looking for common genetic determinants for sFTD. We found a cluster of variants at the MAPT (rs199443; p = 2.5 × 10−12, OR = 1.27) and APOE (rs6857; p = 1.31 × 10−12, OR = 1.27) loci and a candidate locus on chromosome 3 (rs1009966; p = 2.41 × 10−8, OR = 1.16) in the intergenic region between RPSA and MOBP, contributing to increased risk for sFTD through effects on expression and/or splicing in brain cortex of functionally relevant in-cis genes at the MAPT and RPSA-MOBP loci. The association with the MAPT (H1c clade) and RPSA-MOBP loci may suggest common genetic pleiotropy across FTD and progressive supranuclear palsy (PSP) (MAPT and RPSA-MOBP loci) and across FTD, AD, Parkinson disease (PD), and cortico-basal degeneration (CBD) (MAPT locus). Our data also suggest population specificity of the risk signals, with MAPT and APOE loci associations mainly driven by Central/Nordic and Mediterranean Europeans, respectively. This study lays the foundations for future work aimed at further characterizing population-specific features of potential FTD-discriminant APOE haplotype(s) and the functional involvement and contribution of the MAPT H1c haplotype and RPSA-MOBP loci to pathogenesis of sporadic forms of FTD in brain cortex
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