1,920 research outputs found

    Diatoms as Indicators of Water-level Change in Freshwater Lakes

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    Water-level changes result from a variety of geological, biological, and/or climatic processes. Many of these changes occur over long periods; others may be rapid or result from catastrophic events. In aquatic environments, diatoms are highly sensitive indicator organisms and their microfossils, deposited in lake sediments, can be used to infer environmental changes (Smol, 2008). Unambiguous diatom signals can be reconstructed from lakes isolated from marine or brackish waters (e.g. Fritz et al., this volume; Horton & Sawai, this volume). However, in freshwater systems lake-level changes are often recorded as increases in planktonic (free-floating) diatoms – although as discussed below, interpretation of this signal should be supported by additional evidence

    Comparison of spectra of single sideband and phase modulated signals

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    Comparison of spectra of single-sideband and phase modulated signal

    Ritual Machines I & II: Making Technology at Home

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    Changing patterns of both work-related mobility and domestic arrangements mean that ‘mobile workers’ face challenges to support and engage in family life whilst travelling for work. Phatic devices offer some potential to provide connection at a distance alongside existing communications infrastructure. Through a bespoke design process, incorporating phases of design ethnography, critical technical practice and provotyping we have developed Ritual Machines I and II as material explorations of mobile workers’ lives and practices. In doing this we sought to reflect upon the practices through which families accomplish mobile living, the values they place in technology for doing ‘family’ at a distance and to draw insights in to the potential roles of digital technology in supporting them. We frame the design of our phatic devices in discussion of processes of bespoke design, offer advice on supporting mobile workers when travelling and articulate the values of making a technology at home when designing for domestic and mobile settings

    Magnetic irreversibility and Verwey transition in nano-crystalline bacterial magnetite

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    The magnetic properties of biologically-produced magnetite nanocrystals biomineralized by four different magnetotactic bacteria were compared to those of synthetic magnetite nanocrystals and large, high quality single crystals. The magnetic feature at the Verwey temperature, TVT_{V}, was clearly seen in all nanocrystals, although its sharpness depended on the shape of individual nanoparticles and whether or not the particles were arranged in magnetosome chains. The transition was broader in the individual superparamagnetic nanoparticles for which TB<TVT_{B}<T_{V}, where TBT_{B} is the superparamagnetic blocking temperature. For the nanocrystals organized in chains, the effective blocking temperature TB>TVT_{B}>T_{V} and the Verwey transition is sharply defined. No correlation between the particle size and TVT_{V} was found. Furthermore, measurements of M(H,T,time)M(H,T,time) suggest that magnetosome chains behave as long magnetic dipoles where the local magnetic field is directed along the chain and this result confirms that time-logarithmic magnetic relaxation is due to the collective (dipolar) nature of the barrier for magnetic moment reorientation

    Agonism Reloaded: Potentia, Renewal and Radical Democracy

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    This article focuses on the agonistic account of renewal and discusses its place within the broader horizon of radical democracy. It suggests that while the emphasis which agonistic theorists place on difference and popular struggles (particularly social movement politics) ensures some common ground with other theories of radical democracy, their account of renewal also displays some marked differences. The article explores these differences and discusses whether agonism is sufficient to address the limits of the current neoliberal order

    First Observation of the Rare Decay Mode K-long -> e+ e-

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    In an experiment designed to search for and study very rare two-body decay modes of the K-long, we have observed four examples of the decay K-long -> e+ e-, where the expected background is 0.17+-0.10 events. This observation translates into a branching fraction of 8.7^{+5.7}_{-4.1} X 10^{-12}, consistent with recent theoretical predictions. This result represents by far the smallest branching fraction yet measured in particle physics.Comment: 9 pages, 3 figure

    Obesity and Cancer

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    The article examines the importance of managing weight to reduce risk for developing cancer and for survival among cancer patients and presents a set of strategies that can be useful to guide clinical advice to patients for whom weight control is an important adjunct to risk management or to improve quality of life and disease-free survival after diagnosis

    Lifeworld Inc. : and what to do about it

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    Can we detect changes in the way that the world turns up as they turn up? This paper makes such an attempt. The first part of the paper argues that a wide-ranging change is occurring in the ontological preconditions of Euro-American cultures, based in reworking what and how an event is produced. Driven by the security – entertainment complex, the aim is to mass produce phenomenological encounter: Lifeworld Inc as I call it. Swimming in a sea of data, such an aim requires the construction of just enough authenticity over and over again. In the second part of the paper, I go on to argue that this new world requires a different kind of social science, one that is experimental in its orientation—just as Lifeworld Inc is—but with a mission to provoke awareness in untoward ways in order to produce new means of association. Only thus, or so I argue, can social science add to the world we are now beginning to live in

    Evaluating Active U: an Internet-mediated physical activity program.

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    Background: Engaging in regular physical activity can be challenging, particularly during the winter months. To promote physical activity at the University of Michigan during the winter months, an eight-week Internet-mediated program (Active U) was developed providing participants with an online physical activity log, goal setting, motivational emails, and optional team participation and competition. Methods: This study is a program evaluation of Active U. Approximately 47,000 faculty, staff, and graduate students were invited to participate in the online Active U intervention in the winter of 2007. Participants were assigned a physical activity goal and were asked to record each physical activity episode into the activity log for eight weeks. Statistics for program reach, effectiveness, adoption, and implementation were calculated using the Re-Aim framework. Multilevel regression analyses were used to assess the decline in rates of data entry and goal attainment during the program, to assess the likelihood of joining a team by demographic characteristics, to test the association between various predictors and the number of weeks an individual met his or her goal, and to analyze server load. Results: Overall, 7,483 individuals registered with the Active U website (≈16% of eligible), and 79% participated in the program by logging valid data at least once. Staff members, older participants, and those with a BMI < 25 were more likely to meet their weekly physical activity goals, and average rate of meeting goals was higher among participants who joined a competitive team compared to those who participated individually (IRR = 1.28, P < .001). Conclusion: Internet-mediated physical activity interventions that focus on physical activity logging and goal setting while incorporating team competition may help a significant percentage of the target population maintain their physical activity during the winter months
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