454 research outputs found

    The occurrence of riddled basins and blowout bifurcations in a parametric nonlinear system

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    In this paper, a two parameters family Fβ1,β2F_{\beta_1,\beta_2} of maps of the plane living two different subspaces invariant is studied. We observe that, our model exhibits two chaotic attractors AiA_i, i=0,1i=0,1, lying in these invariant subspaces and identify the parameters at which AiA_i has a locally riddled basin of attraction or becomes a chaotic saddle. Then, the occurrence of riddled basin in the global sense is investigated in an open region of β1β2\beta_1\beta_2-plane. We semi-conjugate our system to a random walk model and define a fractal boundary which separates the basins of attraction of the two chaotic attractors, then we describe riddled basin in detail. We show that the model undergos a sequence of bifurcations: "a blowout bifurcation", "a bifurcation to normal repulsion" and "a bifurcation by creating a new chaotic attractor with an intermingled basin". Numerical simulations are presented graphically to confirm the validity of our results.Comment: 26 pages, 15 figure

    Construction of expression vectors carrying mouse peroxisomal protein gene (PeP) with GST and Flag labels

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    The aim of this study was to construct expression vectors carrying mouse peroxisomal protein gene (PEP-cDNA) in prokaryotic and mammalian expression vectors in chimeric cDNA types, encompassingGST and FLAG with PEP-cDNA. PEP-cDNA was sub-cloned in pGEX6p2 prokaryotic expression vector in order to label this gene with GST to purify PEP protein for further biochemical analysis and identifying related proteins thereafter. FLAG-PEP recombinant DNA was produced and sub-cloned inpUcD3 eukaryotic expression vector to express tagged-PEP protein for transient transfection analysis and identifying intracellular localization of PEP protein in future experiments. PEP-cDNA was amplifiedin different PCR reactions using pEGFP-PEP vector and 2 sets of primers introducing specific restriction sites at the ends of PEP. PCR products with BamHI/SalI restriction sites were treated by restriction enzymes and inserted into the pGEX6p2, downstream of GST tag. PEP-cDNA containingBamHI/ApaI restriction sites and FLAG gene (which amplified using pUcD3-FLAG-PEX3 vector) were used as templates in secondary PCR for amplifying FLAG-PEP recombinant DNA. FLAG-PEP fragment was treated by enzymatic digestion and inserted into the pUcD3 eukaryotic expression vector.pGEX6p2-PEP and pUcD3-FLAG-PEP constructed vectors were transformed into the one shot TOP10 and JM105 bacterial competent cells, respectively. Positive colonies were selected for plasmid preparation. Results confirmed correct amplification of the expected products. PEP-cDNA in both PCRreactions encompasses 630 bp. FLAG fragment containing designed sites was 77 bp and FLAG-PEP fragment was 700 bp. Sequencing of constructed vectors confirmed that PEP-cDNA was tagged appropriately and inserted free of mutation and in frame with GST and FLAG

    Acceptability of HIV self-sampling kits (TINY vial) among people of black African ethnicity in the UK: a qualitative study

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    Background: Increasing routine HIV testing among key populations is a public health imperative, so improving access to acceptable testing options for those in need is a priority. Despite increasing targeted distribution and uptake of HIV self-sampling kits (SSKs) among men who have sex with men in the UK, little is known about why targeted SSK interventions for black African users are not as wide-spread or well-used. This paper addresses this key gap, offering insight into why some groups may be less likely than others to adopt certain types of SSK interventions in particular contexts. These data were collected during the development phase of a larger study to explore the feasibility and acceptability of targeted distribution of SSKs to black African people. Methods: We undertook 6 focus groups with members of the public who self-identified as black African (n = 48), 6 groups with specialists providing HIV and social services to black African people (n = 53), and interviews with HIV specialist consultants and policy-makers (n = 9). Framework analysis was undertaken, using inductive and deductive analysis to develop and check themes. Results: We found three valuable components of targeted SSK interventions for this population: the use of settings and technologies that increase choice and autonomy; targeted offers of HIV testing that preserve privacy and do not exacerbate HIV stigma; and ensuring that the specific kit being used (in this case, the TINY vial) is perceived as simple and reliable. Conclusions: This unique and rigorous research offers insights into participants’ views on SSK interventions, offering key considerations when targeting this population.. Given the plethora of HIV testing options, our work demonstrates that those commissioning and delivering SSK interventions will need to clarify (for users and providers) how each kit type and intervention design adds value. Most significantly, these findings demonstrate that without a strong locus of control over their own circumstances and personal information, black African people are less likely to feel that they can pursue an HIV test that is safe and secure. Thus, where profound social inequalities persist, so will inequalities in HIV testing uptake – by any means

    Physicians’ and nurses’ decision making to encounter neonates with poor prognosis in the neonatal intensive care unit

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    This is an Accepted Manuscript of an article published by Sage in Clinical Ethics on 03/06/2020. Available online: https://journals.sagepub.com/doi/abs/10.1177/1477750920927173This is an Accepted Manuscript of an article published by Sage in Clinical Ethics on 03/06/2020.Available online: https://journals.sagepub.com/doi/abs/10.1177/1477750920927173acceptedVersio

    Body roundness index and waist-to-height ratio are strongly associated with non-alcoholic fatty liver disease: A population-based study

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    Background: A strong association between obesity and non-alcoholic fatty liver disease (NAFLD) has been reported. Objectives: This study was conducted to evaluate if new obesity indices, including a body shape index (ABSI) and body roundness index (BRI), have stronger associations with NAFLD than waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR). Methods: In this cross-sectional study, we utilized the data of 4,872 participants aged 18 74 years from a cohort study conducted among 6,143 subjects in northern Iran. Logistic regression analysis was performed on NAFLD as the outcome and obesity measures (based on Z-score values) as potential predictors. Receiver operating characteristic (ROC) analyses were conducted, in which NAFLD was considered as a reference variable and obesity measures as classification variables. The discriminatory ability of the obesity measures was reported based on area-under-the-curves, and the related cut-off points of BRI and WHtR were determined using the Youden index (YI). Results: Based on our results, BRI (OR = 5.484 for men and OR = 3.482 for women) and WHtR (OR = 5.309 for men and OR = 3.854 for women) showed a higher association with NAFLD than ABSI (OR = 1.363 for men and OR = 1.003 for women) and WHR (OR = 3.123 for men and OR = 1.628 for women). The optimal cut-off points for BRI were 4.00 (sensitivity = 82.7, specificity = 70.8) for men and 5.00 (sensitivity = 83.3, specificity = 71.7) for women. The optimal cut-off points for WHtR were 0.533 (sensitivity = 82.7, specificity = 70.8) for men and 0.580 (sensitivity = 83.3, specificity = 71.7) for women. Conclusions: While BRI and WHtR have equally strong associations with NAFLD, ABSI and WHR have weaker associations with NAFLD than BRI and WHtR. � 2016, Kowsar Corp

    Political stringency, infection rates, and higher education students' adherence to government measures in the Nordic countries and the UK during the first wave of the COVID-19 outbreak

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    Understanding predictors of adherence to governmental measures to prevent the spread of the COVID-19 is fundamental to guide health communication. This study examined whether political stringency and infection rates during the first wave of the pandemic were associated with higher education students' adherence to COVID-19 government measures in the Nordic countries (Denmark, Finland, Norway, Iceland, and Sweden) and the United Kingdom. Both individual- and country-level data were used in present study. An international cross-sectionalsubsample (n = 10,345) of higher-education students was conducted in May–June 2020 to collect individual-level information on socio-demographics, study information, living arrangements, health behaviors, stress, and COVID-19-related concerns, including adherence to government measures. Country-level data on political stringency from the Oxford COVID-19 Government Response Tracker and national infection rates were added to individual-level data. Multiple linear regression analyses stratified by country were conducted. Around 66% of students reported adhering to government measures, with the highest adherence in the UK (73%) followed by Iceland (72%), Denmark (69%), Norway (67%), Finland (64%) and Sweden (49%). Main predictors for higher adherence were older age, being femaleand being worried about getting infected with COVID-19 (individual-level), an increase in number of days since lockdown, political stringency, and information about COVID-19 mortality rates (country-level). However, incidence rate was an inconsistent predictor, which may be explained by imperfect data quality during the onset of the pandemic. We conclude that shorter lockdown periods and political stringency are associated with adherence to government measures among higher education students at the outset of the COVID-19 pandemic.Peer reviewe
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