15,260 research outputs found
Agribusiness Extension: The Past, Present, and Future?
The IFAMR is publish by (IFAMA) the International Food and Agribusiness Management Association. www.ifama.orgagribusiness extension, future, Agribusiness, Teaching/Communication/Extension/Profession, Q130,
Chandra and RXTE Observations of 1E 1547.0-5408: Comparing the 2008 and 2009 Outbursts
We present results from observations of the magnetar 1E 1547.0-5408 (SGR
J1550-5418) taken with the Chandra X-ray Observatory and the Rossi X-ray Timing
Explorer (RXTE) following the source's outbursts in 2008 October and 2009
January. During the time span of the Chandra observations, which covers days 4
through 23 and days 2 through 16 after the 2008 and 2009 events, respectively,
the source spectral shape remained stable, while the pulsar's spin-down rate in
the same span in 2008 increased by a factor of 2.2 as measured by RXTE. The
lack of spectral variation suggests decoupling between magnetar spin-down and
radiative changes, hence between the spin-down-inferred magnetic field strength
and that inferred spectrally. We also found a strong anti-correlation between
the phase-averaged flux and the pulsed fraction in the 2008 and 2009 Chandra
data, but not in the pre-2008 measurements. We discuss these results in the
context of the magnetar model.Comment: 4 figures, accepted for publication in Ap
Magnetars' Giant Flares: the case of SGR 1806-20
We first review on the peculiar characteristics of the bursting and flaring
activity of the Soft Gamma-ray Repeaters and Anomalous X-ray Pulsars. We then
report on the properties of the SGR 1806-20's Giant Flare occurred on 2004
December 27th, with particular interest on the pre and post flare
intensity/hardness correlated variability. We show that these findings are
consistent with the picture of a twisted internal magnetic field which stresses
the star solid crust that finally cracks causing the giant flare (and the
observed torsional oscillations). This crustal fracturing is accompanied by a
simplification of the external magnetic field with a (partial) untwisting of
the magnetosphere.Comment: 6 pages, 2 figures; accepted for publication in the Chinese Journal
for Astronomy and Astrophysics (Vulcano conference - 2005
Ethnobotanical Promotion of Fibroblast Growth Using Yerba Santa Extract
Ethnobotany is a promising method for discovering new drugs, drawing on the knowledge of generations of traditional healers. For hundreds of years, the Chumash people have lived in the coastal regions of California, becoming experts on the many uses of its natural resources. One such resource is the Yerba Santa plant (Eriodictyon crassifolium), which was used by the Chumash to treat a myriad of conditions including coughs, chest pain, and fever. It was also used as a poultice on wounds and cuts, suggesting that the plant has a stimulating effect on the growth of skin cells. Because of these qualities, this experiment quantitatively tested the potential of Yerba Santa to encourage fibroblast growth using a goldfish scale keratocyte assay. The extract tested was made by grinding Yerba Santa leaves and storing them overnight in methanol to allow the release of potentially bioactive molecules from the cells. After methanol extraction, the remaining material was then resuspended in a modified solution of PBS (phosphate buffered saline with MgCl, CaCl, and 10% mass by volume dextrose). Individual goldfish (Carassius auratus) scales were then treated with either the modified PBS with extract or the modified PBS alone as a control. After 48 hours, ImageJ software was used to compare the areas of new cell growth. The group treated with extract were found to have enhanced growth relative to the control. The mean growth for control scales was 0.246 mm2 compared to 1.014mm2 for scales treated with the Yerba Santa extract. Mean values were significantly different by a two tailed Student’s t-test, P = 0.0063. These results are consistent with the Chumash’s use of Yerba Santa to treat wounds and skin abrasions indicating that it may be a viable option as a topical treatment of skin disorders
An observational study of children interacting with an augmented story book
We present findings of an observational study investigating how young children interact with augmented reality story books. Children aged between 6 and 7 read and interacted with one of two story books aimed at early literacy education. The books pages were augmented using animated virtual 3D characters, sound, and interactive tasks. Introducing novel media to young children requires system and story designers to consider not only technological issues but also questions arising from story design and the design of interactive sequences. We discuss findings of our study and implications regarding the implementation of augmented story books
The Local Food System Vitality Index: A Pilot Analysis to Demonstrate a Process for Measuring System Performance and Development
Identifying successful development priorities for local food systems (LFSs) is a challenge for producers, LFS advocates, Extension agents, and policymakers. Consumer perceptions and preferences regarding what constitutes an active, healthy, and vibrant LFS often differ within and between diverse communities. Producers, development entities, and others would benefit from rapid assessment processes that provide detailed information on consumer preferences and potential market opportunities within their LFS.
In this paper, we introduce the analytic possibilities of our Local Food System Vitality Index (LFSVI). Using data collected from a pilot survey in Lexington, Kentucky, we rapidly assess the performance of 20 different components of our LFS. The LFSVI differs from most other food system and quality-of-life indices by focusing on the perceptions of resident food consumers.
In our analysis, we identify that Lexington residents generally associate farmers markets, farm-to-fork restaurants, local product diversity, and retail sourcing of local food with high overall vitality of the local food system. While residents score the first three components as high performing, they perceive the retail component to be less functional. We use results such as these to compare which aspects of the LFS are valued versus which are high performing. We do this comparison across different resident food consumer segments in and between geographic locations. Throughout our analysis, we discuss how this index method is generally applicable and conducive to identifying LFS development priorities
Authority, Power and Distributed Leadership
This is the Accepted Manuscript version of an article accepted for publication in Management and Education following peer review. The version of record, Philip Woods, ‘Authority, power and distributed leadership’, Management and Education, Vol 30(4): 155-160, first published online 28 September 2016, is available online via doi: 10.1177/0892020616665779 © 2016 British Educational Leadership, Management & Administration Society (BELMAS) Published by SAGE.A much greater understanding is needed of power in the practice of distributed leadership. This article explores how the concept of social authority might be helpful in achieving this. It suggests that the practice of distributed leadership is characterized by multiple authorities which are constructed in the interactions between people. Rather than there being a uniform hierarchy (relatively flat or otherwise) of formal authority, organizational members may be ‘high’ in some authorities and ‘low’ in others, and people’s positioning in relation to these authorities is dynamic and changeable. The article maps different forms of authorities, provides illustrations from educational institutions, and concludes with implications for educational leadership. A key conclusion is that everyone is involved in the ongoing production of authorities by contributing to who is accepted as or excluded from exercising authority and leadershipPeer reviewedFinal Accepted Versio
Magnetar-like Emission from the Young Pulsar in Kes 75
We report detection of magnetar-like X-ray bursts from the young pulsar PSR
J1846-0258, at the center of the supernova remnant Kes 75. This pulsar, long
thought to be rotation-powered, has an inferred surface dipolar magnetic field
of 4.9x10^13 G, higher than those of the vast majority of rotation-powered
pulsars, but lower than those of the ~12 previously identified magnetars. The
bursts were accompanied by a sudden flux increase and an unprecedented change
in timing behavior. These phenomena lower the magnetic and rotational
thresholds associated with magnetar-like behavior, and suggest that in neutron
stars there exists a continuum of magnetic activity that increases with
inferred magnetic field strength.Comment: 17 pages, 2 figures, accepted for publication in Science. Note: The
content of this paper is embargoed until February 21, 200
Post-outburst X-ray flux and timing evolution of Swift J1822.3-1606
Swift J1822.3-1606 was discovered on 2011 July 14 by the Swift Burst Alert
Telescope following the detection of several bursts. The source was found to
have a period of 8.4377 s and was identified as a magnetar. Here we present a
phase-connected timing analysis and the evolution of the flux and spectral
properties using RXTE, Swift, and Chandra observations. We measure a spin
frequency of 0.1185154343(8) s and a frequency derivative of
at MJD 55761.0, in a timing analysis that include
significant non-zero second and third frequency derivatives that we attribute
to timing noise. This corresponds to an estimated spin-down inferred dipole
magnetic field of G, consistent with previous estimates
though still possibly affected by unmodelled noise. We find that the
post-outburst 1--10 keV flux evolution can be characterized by a
double-exponential decay with decay timescales of and
days. We also fit the light curve with a crustal cooling model which suggests
that the cooling results from heat injection into the outer crust. We find that
the hardness-flux correlation observed in magnetar outbursts also characterizes
the outburst of Swift J1822.3-1606. We compare the properties of Swift
J1822.3-1606 with those of other magnetars and their outbursts.Comment: 12 pages, 8 figures, accepted for publication in Ap
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