8,936 research outputs found
In His Image
The alarm clock clanged noisily. A hairy arm reached in the direction of the noise..
The Fed's entry into check clearing reconsidered
Check collection systems ; Federal Reserve System
Solutions to the tethered galaxy problem in an expanding universe and the observation of receding blueshifted objects
We use the dynamics of a galaxy, set up initially at a constant proper
distance from an observer, to derive and illustrate two counter-intuitive
general relativistic results. Although the galaxy does gradually join the
expansion of the universe (Hubble flow), it does not necessarily recede from
us. In particular, in the currently favored cosmological model, which includes
a cosmological constant, the galaxy recedes from the observer as it joins the
Hubble flow, but in the previously favored cold dark matter model, the galaxy
approaches, passes through the observer, and joins the Hubble flow on the
opposite side of the sky. We show that this behavior is consistent with the
general relativistic idea that space is expanding and is determined by the
acceleration of the expansion of the universe -- not a force or drag associated
with the expansion itself. We also show that objects at a constant proper
distance will have a nonzero redshift; receding galaxies can be blueshifted and
approaching galaxies can be redshifted.Comment: 8 pages including 6 figures, to appear in Am. J. Phys., 2003.
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An international survey of mature students' uses of mobile devices in life and learning
The paper presents research concerned with learner-driven innovative practice with mobile technologies and the interface between formal and informal learning. We build on our previous work investigating student use of personal devices for learning, work, social interaction and entertainment. A recent phase of the research included an international survey focusing on students registered on selected Masters and doctoral programmes in the UK, Sweden, Portugal, Hong Kong and Australia. The research gives an account of everyday uses and more unusual deployments of personal technologies by students from departments of education and technology. It illuminates learner choices and preferences, attitudes towards work–life boundaries, evolving social and cultural practices, and the impacts of technological change
Learning Through Participation in Joint Management Committees for Reservoir-Level Irrigation Governance in Thailand
The UN indicates that water for irrigation and food production constitutes one of the greatest pressures on freshwater resources, especially within the Asian region. Recent developmentsin water management relate to participatory governance, where civil society is included in thepolitical, social, economic, and administrative systems that develop and manage water resources.In Thailand, the Royal Irrigation Department has adopted Participatory Irrigation Management(PIM), which involves multiple sectors of water users in decision-making at all levels of irrigationsystem management. This research identified learning outcomes associated with participationin Joint Management Committees for Irrigation (JMC), the top PIM governance tier,particularly related to governance and sustainable water management. Our research was qualitative following a case study approach, utilising 51 semi-structured interviews at two sites,participant observation, and document reviews. Results showed that participating in PIM activitiesfacilitated both instrumental (e.g. technical knowledge, skills and information, and task-basedlearning) and communicative (e.g. insights into the interests of others, communication strategies,and comparative reflection) learning among JMC participants. Findings also showed that actionoutcomes based on learning were mainly related to adopting new governance systems and conserving water for future irrigation use
The detection of cervical intraepithelial neoplasia by electrical impedance spectroscopy: The effects of acetic acid and tissue homogeneity
Objective. To evaluate the efficacy of an electrical impedance probe (Epitheliometer) in the diagnosis of high grade cervical intraepithelial neoplasia (CIN) in women referred with cervical smear abnormalities and to assess the effect of acetic acid (AA) and tissue boundaries on the measurements.
Methods. A prospective observational study was undertaken in the colposcopy clinic. One hundred and sixty-five women, either with a clinical indication or abnormal cervical cytology, were recruited into the study. A pencil type probe was used to record impedance spectra from 12 points on the cervix before and after the application of 5% AA. Spectra were also recorded from tissue boundaries. Colposcopic examinations, including probe positioning, were video recorded to allow for correlations between histopathological diagnosis of colposcopically directed biopsies, colposcopic impression and the diagnosis based on impedance measurements.
Results. Receiver operating characteristic (ROC) curves were derived. The areas under the curves (AUCs) to discriminate original squamous from high grade CIN were 0.80 (pre AA) and 0.79 (post AA). Comparison of these curves showed no significant difference, indicating that application of AA does not produce a large change in spectra. The probe Could distinguish tissue boundaries from homogeneous tissue points.
Conclusion. The Epitheliometer has the potential to be used as an adjunct to colposcopy in the diagnosis of high grade CIN. It has the advantage of real time results, decreasing the need for diagnostic cervical biopsies, and facilitates a wider use of the 'see and treat' policy without the risk of overtreatment. (C) 2009 Elsevier Inc. All rights reserved
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