43 research outputs found

    Authentication Aura: A cooperative and distributed approach to user authentication on mobile devices

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    As information technology pervades our lives we have increasingly come to rely on these evermore sophisticated and ubiquitous items of equipment. Portability and the desire to be connected around the clock has driven the rapid growth in adoption of mobile devices that enable us to talk, message, tweet and inform at will, whilst providing a means to shop and administer bank accounts. These high value, high risk, desirable devices are increasingly the target of theft and improvement in their protection is actively sought by Governments and security agencies. Although forms of security are in place they are compromised by human reluctance and inability to administer them effectively. With typical users operating across multiple devices, including traditional desktop PCs, laptops, tablets and smartphones, they can regularly find themselves having a variety of devices open concurrently. Even if the most basic security is in place, there is a resultant need to repeatedly authenticate, representing a potential source of hindrance and frustration. This thesis explores the need for a novel approach to user authentication, which will reduce the authentication burden whilst providing a secure yet adaptive security mechanism; a so called Authentication Aura. It proposes that the latent security potential contained in surrounding devices and possessions in everyday life can be leveraged to augment security, and provides a framework for a distributed and cooperative approach. An experiment was performed to ascertain the technological infrastructure, devices and inert objects that surround individuals throughout the day. Using twenty volunteers, over a fourteen-day period a dataset of 1.57 million recorded observations was gathered, which confirmed that between 6am and 12pm a significant device or possession is in near proximity 97.84% of the time. Using the data provided by the experiment as the basis for a simulation of the framework, it suggests a reduction of up to 80.36% in the daily number of required authentications for a user operating a device once every 30 minutes, with a 10 minute screen lock in place. Examining the influence of location alone indicated a reduction of 50.74% in user interventions lowering the average from 32 to 15.76, the addition of the surroundings reducing this further to 13.00. The analysis also investigated how a user’s own authentication status could be used to negate the need to repeatedly manually authenticate and it was found that it delayed the process for up to 90 minutes for an individual user. Ultimately, it confirms that during device activation it is possible to remove the need to authenticate with the Authentication Aura providing sufficient assurance.Orange/France Teleco

    Rho-mediated Contractility Exposes a Cryptic Site in Fibronectin and Induces Fibronectin Matrix Assembly

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    Many factors influence the assembly of fibronectin into an insoluble fibrillar extracellular matrix. Previous work demonstrated that one component in serum that promotes the assembly of fibronectin is lysophosphatidic acid (Zhang, Q., W.J. Checovich, D.M. Peters, R.M. Albrecht, and D.F. Mosher. 1994. J. Cell Biol. 127:1447–1459). Here we show that C3 transferase, an inhibitor of the low molecular weight GTP-binding protein Rho, blocks the binding of fibronectin and the 70-kD NH2-terminal fibronectin fragment to cells and blocks the assembly of fibronectin into matrix induced by serum or lysophosphatidic acid. Microinjection of recombinant, constitutively active Rho into quiescent Swiss 3T3 cells promotes fibronectin matrix assembly by the injected cells. Investigating the mechanism by which Rho promotes fibronectin polymerization, we have used C3 to determine whether integrin activation is involved. Under conditions where C3 decreases fibronectin assembly we have only detected small changes in the state of integrin activation. However, several inhibitors of cellular contractility, that differ in their mode of action, inhibit cell binding of fibronectin and the 70-kD NH2-terminal fibronectin fragment, decrease fibronectin incorporation into the deoxycholate insoluble matrix, and prevent fibronectin's assembly into fibrils on the cell surface. Because Rho stimulates contractility, these results suggest that Rho-mediated contractility promotes assembly of fibronectin into a fibrillar matrix. One mechanism by which contractility could enhance fibronectin assembly is by tension exposing cryptic self-assembly sites within fibronectin that is being stretched. Exploring this possibility, we have found a monoclonal antibody, L8, that stains fibronectin matrices differentially depending on the state of cell contractility. L8 was previously shown to inhibit fibronectin matrix assembly (Chernousov, M.A., A.I. Faerman, M.G. Frid, O.Y. Printseva, and V.E. Koteliansky. 1987. FEBS (Fed. Eur. Biochem. Soc.) Lett. 217:124–128). When it is used to stain normal cultures that are developing tension, it reveals a matrix indistinguishable from that revealed by polyclonal anti-fibronectin antibodies. However, the staining of fibronectin matrices by L8 is reduced relative to the polyclonal antibody when the contractility of cells is inhibited by C3. We have investigated the consequences of mechanically stretching fibronectin in the absence of cells. Applying a 30–35% stretch to immobilized fibronectin induced binding of soluble fibronectin, 70-kD fibronectin fragment, and L8 monoclonal antibody. Together, these results provide evidence that self-assembly sites within fibronectin are exposed by tension

    Young people's views on the potential use of telemedicine consultations for sexual health: results of a national survey

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    <p>Abstract</p> <p>Background</p> <p>Young people are disproportionately affected by sexually transmissible infections in Australia but face barriers to accessing sexual health services, including concerns over confidentiality and, for some, geographic remoteness. A possible innovation to increase access to services is the use of telemedicine.</p> <p>Methods</p> <p>Young people's (aged 16-24) pre-use views on telephone and webcam consultations for sexual health were investigated through a widely-advertised national online survey in Australia. Descriptive statistics were used to describe the study sample and chi-square, Mann-Whitney U test, or t-tests were used to assess associations. Multinomial logistic regression was used to explore the association between the three-level outcome variable (first preference in person, telephone or webcam, and demographic and behavioural variables); odds ratios and 95%CI were calculated using in person as the reference category. Free text responses were analysed thematically.</p> <p>Results</p> <p>A total of 662 people completed the questionnaire. Overall, 85% of the sample indicated they would be willing to have an in-person consultation with a doctor, 63% a telephone consultation, and 29% a webcam consultation. Men, respondents with same-sex partners, and respondents reporting three or more partners in the previous year were more willing to have a webcam consultation. Imagining they lived 20 minutes from a doctor, 83% of respondents reported that their first preference would be an in-person consultation with a doctor; if imagining they lived two hours from a doctor, 51% preferred a telephone consultation. The main objections to webcam consultations in the free text responses were privacy and security concerns relating to the possibility of the webcam consultation being recorded, saved, and potentially searchable and retrievable online.</p> <p>Conclusions</p> <p>This study is the first we are aware of that seeks the views of young people on telemedicine and access to sexual health services. Although only 29% of respondents were willing to have a webcam consultation, such a service may benefit youth who may not otherwise access a sexual health service. The acceptability of webcam consultations may be increased if medical clinics provide clear and accessible privacy policies ensuring that consultations will not be recorded or saved.</p

    Detecting parent of origin and dominant QTL in a two-generation commercial poultry pedigree using variance component methodology

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    <p>Abstract</p> <p>Introduction</p> <p>Variance component QTL methodology was used to analyse three candidate regions on chicken chromosomes 1, 4 and 5 for dominant and parent-of-origin QTL effects. Data were available for bodyweight and conformation score measured at 40 days from a two-generation commercial broiler dam line. One hundred dams were nested in 46 sires with phenotypes and genotypes on 2708 offspring. Linear models were constructed to simultaneously estimate fixed, polygenic and QTL effects. Different genetic models were compared using likelihood ratio test statistics derived from the comparison of full with reduced or null models. Empirical thresholds were derived by permutation analysis.</p> <p>Results</p> <p>Dominant QTL were found for bodyweight on chicken chromosome 4 and for bodyweight and conformation score on chicken chromosome 5. Suggestive evidence for a maternally expressed QTL for bodyweight and conformation score was found on chromosome 1 in a region corresponding to orthologous imprinted regions in the human and mouse.</p> <p>Conclusion</p> <p>Initial results suggest that variance component analysis can be applied within commercial populations for the direct detection of segregating dominant and parent of origin effects.</p

    Polygenic prediction of educational attainment within and between families from genome-wide association analyses in 3 million individuals

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    We conduct a genome-wide association study (GWAS) of educational attainment (EA) in a sample of ~3 million individuals and identify 3,952 approximately uncorrelated genome-wide-significant single-nucleotide polymorphisms (SNPs). A genome-wide polygenic predictor, or polygenic index (PGI), explains 12-16% of EA variance and contributes to risk prediction for ten diseases. Direct effects (i.e., controlling for parental PGIs) explain roughly half the PGI's magnitude of association with EA and other phenotypes. The correlation between mate-pair PGIs is far too large to be consistent with phenotypic assortment alone, implying additional assortment on PGI-associated factors. In an additional GWAS of dominance deviations from the additive model, we identify no genome-wide-significant SNPs, and a separate X-chromosome additive GWAS identifies 57

    Формирование эмоциональной культуры как компонента инновационной культуры студентов

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    Homozygosity has long been associated with rare, often devastating, Mendelian disorders1 and Darwin was one of the first to recognise that inbreeding reduces evolutionary fitness2. However, the effect of the more distant parental relatedness common in modern human populations is less well understood. Genomic data now allow us to investigate the effects of homozygosity on traits of public health importance by observing contiguous homozygous segments (runs of homozygosity, ROH), which are inferred to be homozygous along their complete length. Given the low levels of genome-wide homozygosity prevalent in most human populations, information is required on very large numbers of people to provide sufficient power3,4. Here we use ROH to study 16 health-related quantitative traits in 354,224 individuals from 102 cohorts and find statistically significant associations between summed runs of homozygosity (SROH) and four complex traits: height, forced expiratory lung volume in 1 second (FEV1), general cognitive ability (g) and educational attainment (nominal p<1 × 10−300, 2.1 × 10−6, 2.5 × 10−10, 1.8 × 10−10). In each case increased homozygosity was associated with decreased trait value, equivalent to the offspring of first cousins being 1.2 cm shorter and having 10 months less education. Similar effect sizes were found across four continental groups and populations with different degrees of genome-wide homozygosity, providing convincing evidence for the first time that homozygosity, rather than confounding, directly contributes to phenotypic variance. Contrary to earlier reports in substantially smaller samples5,6, no evidence was seen of an influence of genome-wide homozygosity on blood pressure and low density lipoprotein (LDL) cholesterol, or ten other cardio-metabolic traits. Since directional dominance is predicted for traits under directional evolutionary selection7, this study provides evidence that increased stature and cognitive function have been positively selected in human evolution, whereas many important risk factors for late-onset complex diseases may not have been

    Genome-wide meta-analysis of 241,258 adults accounting for smoking behaviour identifies novel loci for obesity traits

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    Few genome-wide association studies (GWAS) account for environmental exposures, like smoking, potentially impacting the overall trait variance when investigating the genetic contribution to obesity-related traits. Here, we use GWAS data from 51,080 current smokers and 190,178 nonsmokers (87% European descent) to identify loci influencing BMI and central adiposity, measured as waist circumference and waist-to-hip ratio both adjusted for BMI. We identify 23 novel genetic loci, and 9 loci with convincing evidence of gene-smoking interaction (GxSMK) on obesity-related traits. We show consistent direction of effect for all identified loci and significance for 18 novel and for 5 interaction loci in an independent study sample. These loci highlight novel biological functions, including response to oxidative stress, addictive behaviour, and regulatory functions emphasizing the importance of accounting for environment in genetic analyses. Our results suggest that tobacco smoking may alter the genetic susceptibility to overall adiposity and body fat distribution.Peer reviewe

    Rare and low-frequency coding variants alter human adult height

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    Height is a highly heritable, classic polygenic trait with ~700 common associated variants identified so far through genome - wide association studies . Here , we report 83 height - associated coding variants with lower minor allele frequenc ies ( range of 0.1 - 4.8% ) and effects of up to 2 16 cm /allele ( e.g. in IHH , STC2 , AR and CRISPLD2 ) , >10 times the average effect of common variants . In functional follow - up studies, rare height - increasing alleles of STC2 (+1 - 2 cm/allele) compromise d proteolytic inhibition of PAPP - A and increased cleavage of IGFBP - 4 in vitro , resulting in higher bioavailability of insulin - like growth factors . The se 83 height - associated variants overlap genes mutated in monogenic growth disorders and highlight new biological candidates ( e.g. ADAMTS3, IL11RA, NOX4 ) and pathways ( e.g . proteoglycan/ glycosaminoglycan synthesis ) involved in growth . Our results demonstrate that sufficiently large sample sizes can uncover rare and low - frequency variants of moderate to large effect associated with polygenic human phenotypes , and that these variants implicate relevant genes and pathways

    New genetic loci link adipose and insulin biology to body fat distribution.

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    Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

    Genome-wide association study identifies 74 loci associated with educational attainment

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    Educational attainment is strongly influenced by social and other environmental factors, but genetic factors are estimated to account for at least 20% of the variation across individuals1. Here we report the results of a genome-wide association study (GWAS) for educational attainment that extends our earlier discovery sample1,2 of 101,069 individuals to 293,723 individuals, and a replication study in an independent sample of 111,349 individuals from the UK Biobank. We identify 74 genome-wide significant loci associated with the number of years of schooling completed. Single-nucleotide polymorphisms associated with educational attainment are disproportionately found in genomic regions regulating gene expression in the fetal brain. Candidate genes are preferentially expressed in neural tissue, especially during the prenatal period, and enriched for biological pathways involved in neural development. Our findings demonstrate that, even for a behavioural phenotype that is mostly environmentally determined, a well-powered GWAS identifies replicable associated genetic variants that suggest biologically relevant pathways. Because educational attainment is measured in large numbers of individuals, it will continue to be useful as a proxy phenotype in efforts to characterize the genetic influences of related phenotypes, including cognition and neuropsychiatric diseases
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