862 research outputs found

    Biomarkers of oxidative stress: methods and measures of oxidative DNA damage (COMET assay) and telomere shortening

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    Oxidative stress is fast becoming the nutritional and medical buzzword for the twenty-first century. The theoretical importance of oxidative stress in diabetes is highlighted by its potential double impact on metabolic dysfunction on one hand and the vascular system on the other hand. The new concept of oxidative stress, being an important trigger in the onset and progression of diabetes and its complications, emphasizes the need for measurement of markers of oxidation to assess the degree of oxidative stress. While we have been routinely measuring biomarkers in our molecular epidemiology projects, here we discuss the utility of two assays, (a) DNA damage assessment by COMET measurement and (b) telomere length measurement. As DNA damage is efficiently repaired by cellular enzymes, its measurement gives a snapshot view of the level of oxidative stress. The protocol allows for measurement of oxidative DNA damage (FPG-sensitive DNA strand breaks). Telomere length measured by Southern blotting technique allows one to estimate the chronic burden of oxidative stress at the molecular level and is now considered as biomarker of biological aging

    The statistics of the entanglement changes generated by the Hadamard-CNOT quantum circuit

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    We consider the change of entanglement of formation ΔE\Delta E produced by the Hadamard-CNOT circuit on a general (pure or mixed) state ρ\rho describing a system of two qubits. We study numerically the probabilities of obtaining different values of ΔE\Delta E, assuming that the initial state is randomly distributed in the space of all states according to the product measure recently introduced by Zyczkowski {\it et al.} [Phys. Rev. A {\bf 58} (1998) 883].Comment: 12 pages, 2 figure

    Proton structure function at small Q^2

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    A fit is made to the data for the proton structure function up to Q^2=10 GeV^2, including the real gamma p total cross-section. It is economical and simple, and its form is motivated by physical principles. It is extrapolated down to very small values of x. Data for the ratio (nu W_2^n/nu W_2^p) are also fitted. A FORTRAN program for the fit to (nu W_2^p) is available by email on request Figure 5 from the original version has been deleted.Comment: 10 pages plus 9 figure

    Associations of depression and anxiety symptoms with sexual behaviour in women and heterosexual men attending sexual health clinics: a cross-sectional study.

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    OBJECTIVE: To assess the association of symptoms of depression and anxiety with sexual risk behaviour and history, among women and heterosexual men attending genitourinary medicine (GUM) clinics. METHODS: Attitudes to and Understanding of Risk of Acquisition of HIV (AURAH) was a cross-sectional, self-administered questionnaire study recruited from 20 GUM clinics in England, 2013-2014. This analysis included women and heterosexual men. The prevalence of depression and anxiety symptoms was assessed. Modified Poisson regression was used to produce adjusted prevalence ratios (aPR) for the association of t demographic, socioeconomic and lifestyle factors with depression and anxiety, adjusted for gender, age, ethnicity, education level and study region. Among individuals reporting sex in the past 3 months, associations of depression and anxiety with sexual risk behaviour and history were assessed separately by gender, adjusted for age, ethnicity, study region, education and relationship status. RESULTS: Questionnaires were completed by 676 women and 470 heterosexual men. Depression symptoms were reported by 100 (14.8%) women and 33 men (7.0%). Anxiety symptoms were reported by 79 women (11.7%) and 21 men (4.5%). Among women reporting recent sex, those with depression symptoms were more likely to report condomless sex with a non-regular partner, aPR 1.38 (1.07-1.77) and recent condomless sex with two or more partners, 1.80 (1.25-2.59). Women with anxiety symptoms more likely to report recent condomless sex with two or more partners, 1.68 (1.13-2.50), low self-efficacy for condom use, 1.54 (1.02-2.31) and STI diagnosis in the last year 1.51 (1.04-2.20). Among heterosexual men reporting recent sex, depression and anxiety symptoms were associated with low self-efficacy with condom use, 2.32 (1.29-4.19) for depression and 2.23 (1.26-3.94) for anxiety, but not with measures of condomless sex. DISCUSSION: The associations between psychological symptoms and sexual risk behaviours highlight the importance of holistic assessment of need by both general and sexual health clinicians. We highlight the challenge in delivering holistic care associated with fragmentation of sexual health services

    Synchronization and resonance in a driven system of coupled oscillators

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    We study the noise effects in a driven system of globally coupled oscillators, with particular attention to the interplay between driving and noise. The self-consistency equation for the order parameter, which measures the collective synchronization of the system, is derived; it is found that the total order parameter decreases monotonically with noise, indicating overall suppression of synchronization. Still, for large coupling strengths, there exists an optimal noise level at which the periodic (ac) component of the order parameter reaches its maximum. The response of the phase velocity is also examined and found to display resonance behavior.Comment: 17 pages, 3 figure

    ‘What are you going to do, confiscate their passports?’ Professional perspectives on cross-border reproductive travel

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    Objective: This article reports findings from a UK-based study which explored the phenomenon of overseas travel for fertility treatment. The first phase of this project aimed to explore how infertility clinicians and others professionally involved in fertility treatment understand the nature and consequences of cross-border reproductive travel. Background: There are indications that, for a variety of reasons, people from the UK are increasingly travelling across national borders to access assisted reproductive technologies. While research with patients is growing, little is known about how ‘fertility tourism’ is perceived by health professionals and others with a close association with infertility patients. Methods: Using an interpretivist approach, this exploratory research included focussed discussions with 20 people professionally knowledgeable about patients who had either been abroad or were considering having treatment outside the UK. Semi-structured interviews were recorded, transcribed verbatim and subjected to a thematic analysis. Results: Three conceptual categories are developed from the data: ‘the autonomous patient’; ‘cross-border travel as risk’, and ‘professional responsibilities in harm minimisation’. Professionals construct nuanced, complex and sometimes contradictory narratives of the ‘fertility traveller’, as vulnerable and knowledgeable; as engaged in risky behaviour and in its active minimisation. Conclusions: There is little support for the suggestion that states should seek to prevent cross-border treatment. Rather, an argument is made for less direct strategies to safeguard patient interests. Further research is required to assess the impact of professional views and actions on patient choices and patient experiences of treatment, before, during and after travelling abroad

    Phase synchronization and noise-induced resonance in systems of coupled oscillators

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    We study synchronization and noise-induced resonance phenomena in systems of globally coupled oscillators, each possessing finite inertia. The behavior of the order parameter, which measures collective synchronization of the system, is investigated as the noise level and the coupling strength are varied, and hysteretic behavior is manifested. The power spectrum of the phase velocity is also examined and the quality factor as well as the response function is obtained to reveal noise-induced resonance behavior.Comment: to be published in Phys. Rev.
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