450 research outputs found

    Musical preferences and technologies: Contemporary material and symbolic distinctions criticised

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    Today how individuals interact with various cultural items is not perfectly consistent with theoretical frameworks of influential scholars on cultural consumption, such as Bourdieu (1984), Gans (1999), and Peterson and Simkus (1992). One such variation is in the ever increasing variety of technological modes to acquire and listen to music (Pinch and Bijsterveld, 2004). However, as a consequence of digital divides (van Dijk, 2006), technological items may not be distributed equally among social groups. At present, the value of status-making through a preference for different genres of music extends itself to different forms of consumption and ways of experiencing music. We are yet to fully understand the power these practices have on generating status. This article is therefore motivated by the need to integrate within quantitative frameworks of taste and cultural consumption, an analysis of individuals’ technological engagement. These two dimensions, integrated as components of musical practices, enhance our understanding of cultural boundaries across different social groups.The objective is to bridge a gap detected in the literature, addressing the following questions: Are technological modes to listen to music related to musical tastes

    Reliability and validity of three questionnaires measuring context-specific sedentary behaviour and associated correlates in adolescents, adults and older adults

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    BACKGROUND: Reliable and valid measures of total sedentary time, context-specific sedentary behaviour (SB) and its potential correlates are useful for the development of future interventions. The purpose was to examine test-retest reliability and criterion validity of three newly developed questionnaires on total sedentary time, context-specific SB and its potential correlates in adolescents, adults and older adults. METHODS: Reliability and validity was tested in six different samples of Flemish (Belgium) residents. For the reliability study, 20 adolescents, 22 adults and 20 older adults filled out the age-specific SB questionnaire twice. Test-retest reliability was analysed using Kappa coefficients, Intraclass Correlation Coefficients and/or percentage agreement, separately for the three age groups. For the validity study, data were retrieved from 62 adolescents, 33 adults and 33 older adults, with activPAL as criterion measure. Spearman correlations and Bland-Altman plots (or non-parametric approach) were used to analyse criterion validity, separately for the three age groups and for weekday, weekend day and average day. RESULTS: The test-retest reliability for self-reported total sedentary time indicated following values: ICC = 0.37-0.67 in adolescents; ICC = 0.73-0.77 in adults; ICC = 0.68-0.80 in older adults. Item-specific reliability results (e.g. context-specific SB and its potential correlates) showed good-to-excellent reliability in 67.94%, 68.90% and 66.38% of the items in adolescents, adults and older adults respectively. All items belonging to sedentary-related equipment and simultaneous SB showed good reliability. The sections of the questionnaire with lowest reliability were: context-specific SB (adolescents), potential correlates of computer use (adults) and potential correlates of motorized transport (older adults). Spearman correlations between self-reported total sedentary time and the activPAL were different for each age group: rho = 0.02-0.42 (adolescents), rho = 0.06-0.52 (adults), rho = 0.38-0.50 (older adults). Participants over-reported total sedentary time (except for weekend day in older adults) compared to the activPAL, for weekday, weekend day and average day respectively by +57.05%, +46.29%, +53.34% in adolescents; +40.40%, +19.15%, +32.89% in adults; +10.10%, -6.24%, +4.11% in older adults. CONCLUSIONS: The questionnaires showed acceptable test-retest reliability and criterion validity. However, over-reporting of total SB was noticeable in adolescents and adults. Nevertheless, these questionnaires will be useful in getting context-specific information on SB

    The global extent of biodiversity offset implementation under no net loss policies

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    ‘No net loss’ (NNL) biodiversity policies, which seek to neutralize ongoing biodiversity losses caused by economic development activities, are applicable worldwide. Yet there has been no global assessment concerning practical measures actually implemented under NNL policies. Here, we systematically map the global implementation of biodiversity offsets (‘offsets’) – a crucial yet controversial NNL practice. We find, firstly, that offsets occupy an area up to two orders of magnitude larger than previously suggested: 12,983 offset projects extending over ?153,679?_(-64,223)^(+25,013) km2 across 37 countries. Secondly, offsets are far from homogeneous in implementation, and emerging economies (particularly in South America) are more dominant in terms of global offsetting area than expected. Thirdly, most offset projects are very small, and the overwhelming majority (99.7%) arise through regulatory requirements rather than prominent project finance safeguards. Our database provides a sampling frame via which future studies could evaluate the efficacy of NNL policies

    Boolean Dynamics with Random Couplings

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    This paper reviews a class of generic dissipative dynamical systems called N-K models. In these models, the dynamics of N elements, defined as Boolean variables, develop step by step, clocked by a discrete time variable. Each of the N Boolean elements at a given time is given a value which depends upon K elements in the previous time step. We review the work of many authors on the behavior of the models, looking particularly at the structure and lengths of their cycles, the sizes of their basins of attraction, and the flow of information through the systems. In the limit of infinite N, there is a phase transition between a chaotic and an ordered phase, with a critical phase in between. We argue that the behavior of this system depends significantly on the topology of the network connections. If the elements are placed upon a lattice with dimension d, the system shows correlations related to the standard percolation or directed percolation phase transition on such a lattice. On the other hand, a very different behavior is seen in the Kauffman net in which all spins are equally likely to be coupled to a given spin. In this situation, coupling loops are mostly suppressed, and the behavior of the system is much more like that of a mean field theory. We also describe possible applications of the models to, for example, genetic networks, cell differentiation, evolution, democracy in social systems and neural networks.Comment: 69 pages, 16 figures, Submitted to Springer Applied Mathematical Sciences Serie

    Mutability and Importance of a Hypermutable Cell Subpopulation that Produces Stress-Induced Mutants in Escherichia coli

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    In bacterial, yeast, and human cells, stress-induced mutation mechanisms are induced in growth-limiting environments and produce non-adaptive and adaptive mutations. These mechanisms may accelerate evolution specifically when cells are maladapted to their environments, i.e., when they are are stressed. One mechanism of stress-induced mutagenesis in Escherichia coli occurs by error-prone DNA double-strand break (DSB) repair. This mechanism was linked previously to a differentiated subpopulation of cells with a transiently elevated mutation rate, a hypermutable cell subpopulation (HMS). The HMS could be important, producing essentially all stress-induced mutants. Alternatively, the HMS was proposed to produce only a minority of stress-induced mutants, i.e., it was proposed to be peripheral. We characterize three aspects of the HMS. First, using improved mutation-detection methods, we estimate the number of mutations per genome of HMS-derived cells and find that it is compatible with fitness after the HMS state. This implies that these mutants are not necessarily an evolutionary dead end, and could contribute to adaptive evolution. Second, we show that stress-induced Lac+ mutants, with and without evidence of descent from the HMS, have similar Lac+ mutation sequences. This provides evidence that HMS-descended and most stress-induced mutants form via a common mechanism. Third, mutation-stimulating DSBs introduced via I-SceI endonuclease in vivo do not promote Lac+ mutation independently of the HMS. This and the previous finding support the hypothesis that the HMS underlies most stress-induced mutants, not just a minority of them, i.e., it is important. We consider a model in which HMS differentiation is controlled by stress responses. Differentiation of an HMS potentially limits the risks of mutagenesis in cell clones

    The effects of low-impact mutations in digital organisms

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    <p>Abstract</p> <p>Background</p> <p>Avida is a computer program that performs evolution experiments with digital organisms. Previous work has used the program to study the evolutionary origin of complex features, namely logic operations, but has consistently used extremely large mutational fitness effects. The present study uses Avida to better understand the role of low-impact mutations in evolution.</p> <p>Results</p> <p>When mutational fitness effects were approximately 0.075 or less, no new logic operations evolved, and those that had previously evolved were lost. When fitness effects were approximately 0.2, only half of the operations evolved, reflecting a threshold for selection breakdown. In contrast, when Avida's default fitness effects were used, all operations routinely evolved to high frequencies and fitness increased by an average of 20 million in only 10,000 generations.</p> <p>Conclusions</p> <p>Avidian organisms evolve new logic operations only when mutations producing them are assigned high-impact fitness effects. Furthermore, purifying selection cannot protect operations with low-impact benefits from mutational deterioration. These results suggest that selection breaks down for low-impact mutations below a certain fitness effect, the <it>selection threshold</it>. Experiments using biologically relevant parameter settings show the tendency for increasing genetic load to lead to loss of biological functionality. An understanding of such genetic deterioration is relevant to human disease, and may be applicable to the control of pathogens by use of lethal mutagenesis.</p

    Central and East European migrant men who have sex with men in London: a comparison of recruitment methods

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    Background: Following the expansion of the European Union, there has been a large influx of Central and East European (CEE) migrants to the UK. CEE men who have sex with men (MSM) represent a small minority within this population that are none-the-less important to capture in sexual health research among the CEE migrant community. This paper examines the feasibility of recruiting CEE MSM for a survey of sexual behaviour in London using respondent driven sampling (RDS), via gay websites and in GUM clinics.Methods: We sought CEE MSM to start RDS chain referral among GUM clinic attendees, our personal contacts and at gay events and venues in central London. We recruited CEE MSM (n = 485) via two popular websites for gay men in Britain (March-May 2009) and at two central London GUM clinics (n = 51) (July 2008-March 2009).Results: We found seventeen men who knew other CEE MSM in London and agreed to recruit contacts into the study. These men recruited only three men into the study, none of whom recruited any further respondents, and RDS was abandoned after 7 months (July 2008-January 2009). Half of the men that we approached to participate in RDS did not know any other CEE MSM in London. Men who agreed to recruit contacts for RDS were rather more likely to have been in the UK for more than one year (94.1% vs 70.0%, p = 0.052). Men recruited through gay websites and from GUM clinics were similar.Conclusions: The Internet was the most successful method for collecting data on sexual risk behaviour among CEE MSM in London. CEE MSM in London were not well networked. RDS may also have failed because they did not fully understand the procedure and/or the financial incentive was not sufficient motivation to take part

    Successful Reach and Adoption of a workplace health promotion RCT targeting a group of high-risk workers

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    <p>Abstract</p> <p>Background</p> <p>Cleaners are rarely introduced to workplace health promotion programs. The study's objective was to evaluate the reach and adoption of a workplace randomized controlled trial (RCT) among cleaners in Denmark.</p> <p>Methods</p> <p>Cleaning businesses with at least 30 employees, that could offer a weekly 1-hour intervention during working hours, were invited to participate. Employees working at least 20 hours/week were invited to answer a screening questionnaire and consent to participate. Analyses determined the differences in health variables between responders and non-responders, consenters and non-consenters, participants and non-participants and between participants of the RCT's three groups: physical coordination training, cognitive-behavioural theory-based training and reference group.</p> <p>Results</p> <p>From 16 eligible workplaces, a representative sample of 50% adopted the trial. Of 758 eligible employees, 78% responded to the screening questionnaire and 49% consented to participate. Consenters and participants differed from non-consenters and non-participants by having higher BMI, more chronic diseases and poorer musculoskeletal health.</p> <p>Conclusions</p> <p>This study indicates that workplace health promotion programs directed at health risk factors among cleaners enable significant adoption and reach to a high-risk subgroup of the Danish workforce.</p> <p>Trial registration</p> <p>Trial registration ISRCTN96241850</p
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