2,917 research outputs found
Leibniz algebroid associated with a Nambu-Poisson structure
The notion of Leibniz algebroid is introduced, and it is shown that each
Nambu-Poisson manifold has associated a canonical Leibniz algebroid. This fact
permits to define the modular class of a Nambu-Poisson manifold as an
appropiate cohomology class, extending the well-known modular class of Poisson
manifolds
Near-infrared photometry of isolated spirals with and without an AGN. I: The Data
We present infrared imaging data in the J and K' bands obtained for 18 active
spiral galaxies, together with 11 non active galaxies taken as a control
sample. All of them were chosen to satisfy well defined isolation criteria so
that the observed properties are not related to gravitational interaction. For
each object we give: the image in the K' band, the sharp-divided image
(obtained by dividing the observed image by a filtered one), the difference
image (obtained by subtracting a model to the observed one), the color J-K'
image, the ellipticity and position angle profiles, the surface brightness
profiles in J and K', their fits by bulge+disk models and the color gradient.
We have found that four (one) active (control) galaxies previously classified
as non-barred turn out to have bars when observed in the near-infrared. One of
these four galaxies (UGC 1395) also harbours a secondary bar. For 15 (9 active,
6 control) out of 24 (14 active, 10 control) of the optically classified barred
galaxies (SB or SX) we find that a secondary bar (or a disk, a lense or an
elongated ring) is present. The work presented here is part of a large program
(DEGAS) aimed at finding whether there are differences between active and non
active galaxies in the properties of their central regions that could be
connected with the onset of nuclear activity.Comment: Accepted for publication in Astronomy & Astrophysics Supplement
Serie
Sensitivity study of surface wind flow of a limited area model simulating the extratropical storm Delta affecting the Canary Islands
In November 2005 an extratropical storm named Delta affected the Canary Islands (Spain). The high sustained wind and intense gusts experienced caused significant damage. A numerical sensitivity study of Delta was conducted using the Weather Research & Forecasting Model (WRF-ARW). A total of 27 simulations were performed. Non-hydrostatic and hydrostatic experiments were designed taking into account physical parameterizations and geometrical factors (size and position of the outer domain, definition or not of nested grids, horizontal resolution and number of vertical levels). The Factor Separation Method was applied in order to identify the major model sensitivity parameters under this unusual meteorological situation. Results associated to percentage changes relatives to a control run simulation demonstrated that boundary layer and surface layer schemes, horizontal resolutions, hydrostaticity option and nesting grid activation were the model configuration parameters with the greatest impact on the 48 h maximum 10 m horizontal wind speed solution
What is STEM Education?
Editoria
The HealthPia GlucoPack™ Diabetes Phone: A Usability Study
This is a copy of an article published in Diabetes Technology & Therapeutics copyright Mary Ann Liebert, Inc.; Diabetes Technology & Therapeutics is available online at: http://online.liebertpub.com.Background: Type I diabetes is a common chronic disease of childhood. Both the growing influence of peers and the shifting away from parental influence have been implicated as prime elements contributing to poor glycemic outcomes in adolescents. Mobile technology that can be directed towards providing self-management support and modifying potentially negative child parent interaction holds promise to improve control in adolescents with diabetes.
Methods: HealthPia, Inc. (Palisades Park, NJ) has developed a prototype system, the HealthPia GlucoPack™ Diabetes Monitoring System, which integrates a small blood glucose monitoring device into the battery pack of a cell phone. A pilot study used mixed quantitative and qualitative methods to evaluate user satisfaction with the integrated system, including the potential of the device to transmit self-monitoring data to a website for review and analysis by clinicians, parents, and patients.
Results: Adolescents in our study liked the integration of the two technologies and agreed that the glucometer was easy to use and that the tool was useful in the management of their diabetes.
Conclusions: Future work will focus on the utilization of the diabetes phone as a component of a care delivery system for adolescents with diabetes, including involvement of the health care team and enhancement of the web services that support the use of the phone
Developing and Sustaining Elementary STEM Teacher Leadership Identities
Growing emphasis on elementary STEM education has pushed elementary teachers to face curriculum changes that focus on standards with which they are largely unfamiliar (Smith, 2020; Trygstad et al., 2013). As a result, elementary students are not always exposed to STEM subjects or integration and miss out on opportunities to access and enjoy the hands-on, inquiry-driven activities that accompany them. This disproportionally impacts high-need, urban districts that serve Black and Brown children and families, thus perpetuating inequities in STEM education and careers (Tate et al., 2012).
To address these issues, we designed a Fellowship program that strengthened K-12 STEM teacher leadership in local, high-need, schools. In this paper, we take a closer look at how five elementary teachers took on STEM teacher leader identities and then sustained and strengthened those even as program supports reduced. We asked: How do elementary teachers develop and sustain STEM and leadership identities through participation in a Master Teacher Fellowship? Using positional identity and self-efficacy lenses, we interpreted focus group interviews, coursework, reflections, and Fellowship meeting notes. Findings suggest that elementary teachers developed their identities gradually—first, as they recognized themselves as STEM teachers; next, as they recognized themselves as STEM leaders; and then, as others recognized them as STEM teacher leaders and positioned them to enact change in their schools and to support their colleagues. Implications for teacher educators shed light on how elementary teachers can be best supported in increasing STEM learning for their students across grade levels to effect school change
Time-dependent Mechanics and Lagrangian submanifolds of Dirac manifolds
A description of time-dependent Mechanics in terms of Lagrangian submanifolds
of Dirac manifolds (in particular, presymplectic and Poisson manifolds) is
presented. Two new Tulczyjew triples are discussed. The first one is adapted to
the restricted Hamiltonian formalism and the second one is adapted to the
extended Hamiltonian formalism
mu-Opioid inhibition of Ca2+ currents and secretion in isolated terminals of the neurohypophysis occurs via ryanodine-sensitive Ca2+ stores
mu-Opioid agonists have no effect on calcium currents (I(Ca)) in neurohypophysial terminals when recorded using the classic whole-cell patch-clamp configuration. However, mu-opioid receptor (MOR)-mediated inhibition of I(Ca) is reliably demonstrated using the perforated-patch configuration. This suggests that the MOR-signaling pathway is sensitive to intraterminal dialysis and is therefore mediated by a readily diffusible second messenger. Using the perforated patch-clamp technique and ratio-calcium-imaging methods, we describe a diffusible second messenger pathway stimulated by the MOR that inhibits voltage-gated calcium channels in isolated terminals from the rat neurohypophysis (NH). Our results show a rise in basal intracellular calcium ([Ca(2+)]i) in response to application of [D-Ala(2)-N-Me-Phe(4),Gly5-ol]-Enkephalin (DAMGO), a MOR agonist, that is blocked by D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP), a MOR antagonist. Buffering DAMGO-induced changes in [Ca(2+)]i with BAPTA-AM completely blocked the inhibition of both I(Ca) and high-K(+)-induced rises in [Ca(2+)]i due to MOR activation, but had no effect on kappa-opioid receptor (KOR)-mediated inhibition. Given the presence of ryanodine-sensitive stores in isolated terminals, we tested 8-bromo-cyclic adenosine diphosphate ribose (8Br-cADPr), a competitive inhibitor of cyclic ADP-ribose (cADPr) signaling that partially relieves DAMGO inhibition of I(Ca) and completely relieves MOR-mediated inhibition of high-K(+)-induced and DAMGO-induced rises in [Ca(2+)]i. Furthermore, antagonist concentrations of ryanodine completely blocked MOR-induced increases in [Ca(2+)]i and inhibition of I(Ca) and high-K(+)-induced rises in [Ca(2+)]i while not affecting KOR-mediated inhibition. Antagonist concentrations of ryanodine also blocked MOR-mediated inhibition of electrically-evoked increases in capacitance. These results strongly suggest that a key diffusible second messenger mediating the MOR-signaling pathway in NH terminals is [Ca(2+)]i released by cADPr from ryanodine-sensitive stores
Improving Medication Adherence for Chronic Disease Using Integrated e-Technologies
Diabetes mellitus (DM) is a chronic disease affecting more than 285 people worldwide and the fourth leading cause of death. Increasing evidence suggests that many DM patients have poor adherence with prescribed medication therapies, impacting clinical outcomes. Patients' barriers to medication adherence and the extent to which barriers contribute to poor outcomes, however, are not routinely assessed. We designed a dashboard for an electronic health record system to integrate DM disease and medication data, including patient-reported barriers to adherence. Processes to support routine capture of data from patients are also being explored. The dashboard is being evaluated at multiple ambulatory clinics to examine whether integrated electronic tools can support patient-centered decision-making processes involving complex medication regimens for DM and other chronic diseases
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