136 research outputs found

    3D Security, 3Dsec: Trustworthy System Security through 3D Integrated Hardware [poster]

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    Poster, Wednesday Poster Session, NSF Secure and Trustworthy Cyberspace (SaTC) Principal Investigators Meeting, National Harbor, MD, 28 November 2012. [Poster] [Meeting] [Final Report]This project is investigating a novel approach to trustworthy system development based on 3D integration, an emerging chip fabrication technique in which two or more integrated circuit dies are combined into a single stack using vertical conductive posts. Since the dies may be manufactured separately, 3D circuit integration offers the option of enhancing a commodity processor with a variety of custom security functions, which are manufacturing options applicable only to those systems that require them. This research introduces a fundamentally new method to incorporate security mechanisms into hardware and has the potential to significantly shift the economics of trustworthy systems

    Advantages and limitations to the use of optical measurements to study sediment properties

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    Measurements of optical properties have been used for decades to study particle distributions in the ocean. They are useful for estimating suspended mass concentration as well as particle-related properties such as size, composition, packing (particle porosity or density), and settling velocity. Measurements of optical properties are, however, biased, as certain particles, because of their size, composition, shape, or packing, contribute to a specific property more than others. Here, we study this issue both theoretically and practically, and we examine different optical properties collected simultaneously in a bottom boundary layer to highlight the utility of such measurements. We show that the biases we are likely to encounter using different optical properties can aid our studies of suspended sediment. In particular, we investigate inferences of settling velocity from vertical profiles of optical measurements, finding that the effects of aggregation dynamics can seldom be ignored

    Advantages and limitations to the use of optical measurements to study sediment properties

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    © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Boss, E., Sherwood, C. R., Hill, P., & Milligan, T. Advantages and limitations to the use of optical measurements to study sediment properties. Applied Sciences-Basel, 8(12), (2018):2692, doi:10.3390/app8122692.Measurements of optical properties have been used for decades to study particle distributions in the ocean. They are useful for estimating suspended mass concentration as well as particle-related properties such as size, composition, packing (particle porosity or density), and settling velocity. Measurements of optical properties are, however, biased, as certain particles, because of their size, composition, shape, or packing, contribute to a specific property more than others. Here, we study this issue both theoretically and practically, and we examine different optical properties collected simultaneously in a bottom boundary layer to highlight the utility of such measurements. We show that the biases we are likely to encounter using different optical properties can aid our studies of suspended sediment. In particular, we investigate inferences of settling velocity from vertical profiles of optical measurements, finding that the effects of aggregation dynamics can seldom be ignored.This work was supported by the Office of Naval Research and the United States Geological Survey Coastal and Marine Geology Program. The unique instrument platform and data acquisition system was designed and built by technical staff lead by Marinna Martini at the United States Geological Survey Woods Hole Coastal and Marine Science Center. This team was also responsible for deployment and recovery of the instrumentation. We thank the Woods Hole Oceanographic Institution (WHOI) MVCO staff for support during this experiment, and we thank the captains and crews of the R/V Connecticut and the R/V Tioga. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the United States Government. This paper has benefited significantly from insightful comments from D. Stramski, A. Aretxabaleta and two anonymous reviewers

    Relaxin-1–deficient mice develop an age-related progression of renal fibrosis

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    Relaxin-1–deficient mice develop an age-related progression of renal fibrosis.BackgroundRelaxin (RLX) is a peptide hormone that stimulates the breakdown of collagen in preparation for parturition and when administered to various models of induced fibrosis. However, its significance in the aging kidney is yet to be established. In this study, we compared structural and functional changes in the kidney of aging relaxin-1 (RLX-/-) deficient mice and normal (RLX+/+) mice.MethodsThe kidney cortex and medulla of male and female RLX+/+ and RLX-/- mice at various ages were analyzed for collagen content, concentration, and types. Histologic analysis, reverse transcription-polymerase chain reaction (RT-PCR) of relaxin and relaxin receptor mRNA expression, receptor autoradiography, glomerular isolation/analysis, and serum/urine analysis were also employed. Relaxin treatment of RLX-/- mice was used to confirm the antifibrotic effects of the peptide.ResultsWe demonstrate an age-related progression of renal fibrosis in male, but not female, RLX-/- mice with significantly (P < 0.05) increased tissue dry weight, collagen (type I) content and concentration. The increased collagen expression in the kidney was associated with increased glomerular matrix and to a lesser extent, interstitial fibrosis in RLX-/- mice, which also had significantly increased serum creatinine (P < 0.05) and urinary protein (P < 0.05). Treatment of RLX-/- mice with relaxin in established stages of renal fibrosis resulted in the reversal of collagen deposition.ConclusionThis study supports the concept that relaxin may provide a means to regulate excessive collagen deposition during kidney development and in diseased states characterized by renal fibrosis

    The Active for Life Year 5 (AFLY5) school based cluster randomised controlled trial: study protocol for a randomized controlled trial

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    Background: Low levels of physical activity, high levels of sedentary behaviour and low levels of fruit and vegetable consumption are common in children and are associated with adverse health outcomes. The aim of this paper is to describe the protocol for a cluster randomised controlled trial (RCT) designed to evaluate a school-based intervention that aims to increase levels of physical activity, decrease sedentary behaviour and increase consumption of fruit and vegetables in school children. Methods/design: The Active for Life Year 5 (AFLY5) study is a school-based, cluster RCT that targets school children in Year 5 (age 9-10 years). All state junior/primary schools in the area covered by Bristol City and North Somerset Council are invited to participate; special schools are excluded. Eligible schools are randomised to one of two arms: intervention arm (receive the intervention 2011-2012) and control arm (receive the intervention after the final follow-up assessment, 2013-2014). The primary outcomes of the trial are levels of accelerometer assessed physical activity and sedentary behaviour and questionnaire assessed fruit and vegetable consumption. A number of secondary outcomes will also be measured, including body mass index, waist circumference and overweight/obesity. Outcomes will be assessed at baseline (prior to intervention when the children are in Year 4), at the end of intervention ‘immediate follow-up’ and ‘12 months long-term’ follow-up. We will use random effects linear and logistic regression models to compare outcomes by randomised arm. The economic evaluation from a societal perspective will take the form of a cost consequence analysis. Data from focus groups and interviews with pupils, parents and teachers will be used to increase understanding of how the intervention has any effect and is integrated into normal school activity. Discussion: The results of the trial will provide information about the public health effectiveness of a school-based intervention aimed at improving levels of physical activity, sedentary behaviour and diet in children.Debbie A Lawlor, Russell Jago, Sian M Noble, Catherine R Chittleborough, Rona Campbell, Julie Mytton, Laura D Howe, Tim J Peters and Ruth R Kippin

    Epidemiology of Clostridium difficile in infants in Oxfordshire, UK: Risk factors for colonization and carriage, and genetic overlap with regional C. difficile infection strains

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    Background: Approximately 30-40% of children <1 year of age are Clostridium difficile colonized, and may represent a reservoir for adult C. difficile infections (CDI). Risk factors for colonization with toxigenic versus non-toxigenic C. difficile strains and longitudinal acquisition dynamics in infants remain incompletely characterized. Methods: Predominantly healthy infants (≤2 years) were recruited in Oxfordshire, UK, and provided ≥1 fecal samples. Independent risk factors for toxigenic/non-toxigenic C. difficile colonization and acquisition were identified using multivariable regression. Infant C. difficile isolates were whole-genome sequenced to assay genetic diversity and prevalence of toxin-associated genes, and compared with sequenced strains from Oxfordshire CDI cases. Results: 338/365 enrolled infants provided 1332 fecal samples, representing 158 C. difficile colonization or carriage episodes (107[68%] toxigenic). Initial colonization was associated with age, and reduced with breastfeeding but increased with pet dogs. Acquisition was associated with older age, Caesarean delivery, and diarrhea. Breastfeeding and pre-existing C. difficile colonization reduced acquisition risk. Overall 13% of CDI C. difficile strains were genetically related to infant strains. 29(18%) infant C. difficile sequences were consistent with recent direct/indirect transmission to/from Oxfordshire CDI cases (≤2 single nucleotide variants [SNVs]); 79(50%) shared a common origin with an Oxfordshire CDI case within the last ~5 years (0-10 SNVs). The hypervirulent, epidemic ST1/ribotype 027 remained notably absent in infants in this large study, as did other lineages such as STs 10/44 (ribotype 015); the most common strain in infants was ST2 (ribotype 020/014)(22%). Conclusions: In predominantly healthy infants without significant healthcare exposure C. difficile colonization and acquisition reflect environmental exposures, with pet dogs identified as a novel risk factor. Genetic overlap between some infant strains and those isolated from CDI cases suggest common community reservoirs of these C. difficile lineages, contrasting with those lineages found only in CDI cases, and therefore more consistent with healthcare-associated spread
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