2,872 research outputs found
MicroRNA-433 Dampens Glucocorticoid Receptor Signaling, Impacting Circadian Rhythm and Osteoblastic Gene Expression
FUNDING This work was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health [AR44877]; the National Institutes for Dental and Craniofacial Research [5T90DE21989]; a Grant-in-Aid award from the American Society for Bone and Mineral Research; the UConn Health Center Research Advisory council; and the Center for Molecular Medicine at UConn Health. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.Peer reviewedPublisher PD
Suppression of the water ice and snow albedo feedback on planets orbiting red dwarf stars and the subsequent widening of the habitable zone
M-stars comprise 80% of main-sequence stars, and so their planetary systems
provide the best chance for finding habitable planets, i.e.: those with surface
liquid water. We have modelled the broadband albedo or reflectivity of water
ice and snow for simulated planetary surfaces orbiting two observed red dwarf
stars (or M-stars) using spectrally resolved data of the Earth's cryosphere.
The gradual reduction of the albedos of snow and ice at wavelengths greater
than 1 ?m, combined with M-stars emitting a significant fraction of their
radiation at these same longer wavelengths, mean that the albedos of ice and
snow on planets orbiting M-stars are much lower than their values on Earth. Our
results imply that the ice/snow albedo climate feedback is significantly weaker
for planets orbiting M-stars than for planets orbiting G-type stars such as the
Sun. In addition, planets with significant ice and snow cover will have
significantly higher surface temperatures for a given stellar flux if the
spectral variation of cryospheric albedo is considered, which in turn implies
that the outer edge of the habitable zone around M-stars may be 10-30% further
away from the parent star than previously thought.Comment: Final accepted by Astrobiology, 20 pages (double spaced), 3 figures
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Proportional Reasoning as Essential Numeracy
This paper reports an aspect of a large research and development project that aimed to promote middle years school teachersâ understanding and awareness of the pervasiveness of proportional reasoning as integral to numeracy. Teacher survey data of proportional reasoning across the curriculum were mapped on to a rich model of numeracy. Results provided evidence of extensive and creative teaching of proportional reasoning in all learning areas. The capacity of such tasks and activities for promoting student numeracy is theorised
Field theoretic calculation of the surface tension for a model electrolyte system
We carry out the calculation of the surface tension for a model electrolyte
to first order in a cumulant expansion about a free field theory equivalent to
the Debye-H\"uckel approximation. In contrast with previous calculations, the
surface tension is calculated directly without recourse to integrating
thermodynamic relations. The system considered is a monovalent electrolyte with
a region at the interface, of width h, from which the ionic species are
excluded. In the case where the external dielectric constant epsilon_0 is
smaller than the electrolyte solution's dielectric constant epsilon we show
that the calculation at this order can be fully regularized. In the case where
h is taken to be zero the Onsager-Samaras limiting law for the excess surface
tension of dilute electrolyte solutions is recovered, with corrections coming
from a non-zero value of epsilon_0/epsilon.Comment: LaTeX, 14 pages, 3 figures, 1 tabl
Promoting middle school studentsâ proportional reasoning skills through an ongoing professional development programme for teachers
© 2016, Springer Science+Business Media Dordrecht. Proportional reasoning, the ability to use ratios in situations involving comparison of quantities, is essential for mathematical competence, especially in the middle school years, and is an important determinant of success beyond school. Research shows students find proportional reasoning and its foundational concepts difficult. Proportional reasoning does not always develop naturally, however some research suggests that with targeted teaching, its development can be promoted. This paper reports on a large Australian study involving over 130 teachers and their students. A major goal of the study was to investigate the efficacy of ongoing teacher professional development for promoting middle years studentsâ proportional reasoning. A series of professional development workshops was designed to enhance the teachersâ understanding of proportional reasoning and to extend their repertoire of teaching strategies to promote their studentsâ proportional reasoning skills. The workshop design was informed by research literature on proportional reasoning teaching and learning as well as the results of a diagnostic instrument administered to over 2500 middle years students prior to the professional development. Between workshops, the teachers implemented a variety of targeted teaching activities. This paper reports on pre- and post- instrument student data collected at the beginning and end of the first year of the project (i.e., after completion of half of the workshops). The findings suggest that targeted professional development and explicit teaching can make a difference to studentsâ proportional reasoning
DEVELOPEMENT AND VALIDATION OF ANALYTICAL METHOD FOR SIMULTANEOUS ESTIMATION OF CILNIDIPINE AND OLMESARTAN MEDOXOMIL IN BULK AND TABLET DOSAGE FORM BY RP-HPLC
An economical, precise, rapid and accurate RP HPLC method has been developed for the simultaneous estimation of Olmesartan Medoxomil and Cilnidipine in bulk and tablet dosage form. Separation was carried out on Jasco HPLC system equipped with HiQ sil C18 column (250 Ăâ 4.6 mm i.d.) and PDA detector using Methanol: 40 mM Potassium dihydrogen ortho phosphate buffer (90:10 v/v) as the mobile phase.Ortho-phosphoric acid was used to adjust pH to 3.0, and detection was carried out at 254 nm. Results were linear in the range of 5-30 ĂÂŒg/ml for Cilnidipine and 10-50 ĂÂŒg/ml for Olmesartan Medoxomil respectively. The method was successfully applied for the analysis of drugs in pharmaceutical formulation. Results of the analysis were validated statistically and by recovery studies
Dissecting the Cosmic Infrared Background with 3D Instruments
The cosmic infrared background (CIB) consists of emission from distant,
dusty, star-forming galaxies. Energetically, the CIB is very important as it
contains as much energy as the extragalactic optical background. The nature and
evolutionary status of the objects making up the background are, however,
unclear. The CIB peaks at ~150 microns, and as such is most effectively studied
from space. The limited apertures of space-borne telescopes set the angular
resolution that can be attained, and so even Herschel, with its 3.5m diameter,
will be confusion-limited at this wavelengths at ~5mJy. The bulk of the
galaxies contributing to the CIB are fainter than this, so it is difficult to
study them without interferometry. Here we present the results of a preliminary
study of an alternative way of probing fainter than the continuum confusion
limit using far-IR imaging spectroscopy. An instrument capable of such
observations is being planned for SPICA - a proposed Japanese mission with an
aperture equivalent to that of Herschel and more than 2 orders of magnitude
more sensitive. We investigate the potential of imaging spectrometers to break
the continuum confusion limit. We have simulated the capabilities of a
spectrometer with modest field of view (2'x2'), moderate spectral resolution
(R~1-2000) and high sensitivity. We find that such an instrument is capable of
not only detecting line emission from sources with continuum fluxes
substantially below the confusion limit, but also of determining their
redshifts and, where multiple lines are detected, some emission line
diagnostics. We conclude that 3-D imaging spectrometers on cooled far-IR space
telescopes will be powerful new tools for extragalactic far-IR astronomy.Comment: Accepted for publication in Astronomy & Astrophysic
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