10,740 research outputs found
A periodic microfluidic bubbling oscillator: insight into the stability of two-phase microflows
This letter describes a periodically oscillating microfoam flow. For constant
input parameters, both the produced bubble volume and the flow rate vary over a
factor two. We explicit the link between foam topology alternance and flow rate
changes, and construct a retroaction model where bubbles still present
downstream determine the volume of new bubbles, in agreement with experiment.
This gives insight into the various parameters important to maintain
monodispersity and at the same time shows a method to achieve controlled
polydispersity.Comment: 4 page
Depressed youth, suicidality and antidepressants
The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.Robert D Goldney, Peter R Mansfield, Melissa K Raven, Jon N Jureidini, Joseph M Rey, Michael J Dudley, Duncan Toplis
The Affordable Care Act and implications for health care services for American Indian and Alaska Native individuals
American Indian and Alaska Native (AI/AN) populations report poor physical and mental health outcomes while tribal health providers and the Indian Health Service (IHS) operate in a climate of significant under funding. Understanding how the Patient Protection and Affordable Care Act (ACA) affects Native American tribes and the IHS is critical to addressing the improvement of the overall access, quality, and cost of health care within AI/AN communities. This paper summarizes the ACA provisions that directly and/or indirectly affect the service delivery of health care provided by tribes and the IHS
An AC susceptometer for the characterization of large, bulk superconducting samples
The main purpose of this work was to design, develop and construct a simple,
low-cost AC susceptometer to measure large, bulk superconducting samples (up to
32 mm in diameter) in the temperature range 78-120 K. The design incorporates a
double heating system that enables a high heating rate (25 K/hour) while
maintaining a small temperature gradient (< 0.2 K) across the sample. The
apparatus can be calibrated precisely using a copper coil connected in series
with the primary coil. The system has been used successfully to measure the
temperature dependence of the AC magnetic properties of entire RE-Ba-Cu-O
[(RE)BCO] bulk superconducting domains. A typical AC susceptibility measurement
run from 78 K to 95 K takes about 2 hours, with excellent temperature
resolution (temperature step ~ 4 mK) around the critical temperature, in
particular.Comment: 25 pages, 7 figures. Accepted for publication in Measurement Science
and Technolog
What Influences the Diffusion of Grassroots Innovations for Sustainability? Investigating Community Currency Niches
Community action for sustainability is a promising site of socio-technical innovation. Here we test the applicability of co-evolutionary niche theories of innovation diffusion (Strategic Niche Management, SNM) to the context of ‘grassroots innovations’. We present new empirical findings from an international study of 12 community currency niches (such as LETS, time banks, local currencies). These are parallel systems of exchange, designed to operate alongside mainstream money, meeting additional sustainability needs. Our findings confirm SNM predictions that niche-level activity correlates with diffusion success, but we highlight additional or confounding factors, and how niche theories might be adapted to better fit civil-society innovations. In so doing, we develop a model of grassroots innovation niche diffusion which builds on existing work and tailors it to this specific context. The paper concludes with a series of theoretically-informed recommendations for practitioners and policymakers to support the development and potential of grassroots innovations
Drones and Digital Photogrammetry: From Classifications to Continuums for Monitoring River Habitat and Hydromorphology
Recently, we have gained the opportunity to obtain very high-resolution imagery
and topographic data of rivers using drones and novel digital photogrammetric
processing techniques. The high-resolution outputs from this method are
unprecedented, and provide the opportunity to move beyond river habitat classification
systems, and work directly with spatially explicit continuums of data.
Traditionally, classification systems have formed the backbone of physical river
habitat monitoring for their ease of use, rapidity, cost efficiency, and direct comparability.
Yet such classifications fail to characterize the detailed heterogeneity
of habitat, especially those features which are small or marginal. Drones and
digital photogrammetry now provide an alternative approach for monitoring
river habitat and hydromorphology, which we review here using two case studies.
First, we demonstrate the classification of river habitat using drone imagery
acquired in 2012 of a 120 m section of the San Pedro River in Chile, which was at
the technological limits of what could be achieved at that time. Second, we
review how continuums of data can be acquired, using drone imagery acquired
in 2016 from the River Teme in Herefordshire, England. We investigate the precision
and accuracy of these data continuums, highlight key current challenges,
and review current best practices of data collection, processing, and management.
We encourage further quantitative testing and field applications. If current
difficulties can be overcome, these continuums of geomorphic and hydraulic
information hold great potential for providing new opportunities for understanding
river systems to the benefit of both river science and management
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Emotional health in adolescents with and without a history of specific language impairment (SLI)
Objective: This study examined the emotional health of adolescents with and without specific language impairment (SLI).
Method: One hundred and thirty-nine adolescents with a history of SLI (15;10 years) and a peer group of 124 adolescents with normal language development (NLD) (15;11 years) participated, who were in their final year of compulsory schooling. The risk of emotional difficulties was assessed using the Moods and Feelings Questionnaire (MFQ) and the Child Manifest Anxiety Scale-R (CMAS-R). Comprehensive language and cognition data were available for all participants (NLD and SLI) concurrently and also longitudinally for those with SLI.
Results: A clear increased risk of emotional health symptoms was found for the SLI group on both self- and parental-report. Girls scored less favourably than boys when groups were combined, but these were due to the effect of the NLD group, with no gender differences found in the SLI group. Direct links with language and cognition were not obvious. Instead, more diffuse factors such as family history of emotional health difficulties may warrant further investigation.
Conclusion: There is a marked higher rate of anxiety and depression symptoms in adolescents with SLI. However, these do not appear to be a direct result of impoverished communicative experiences
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