6,026 research outputs found
The density of mid-sized Kuiper belt objects from ALMA thermal observations
The densities of mid-sized Kuiper belt objects are a key constraint into
understanding the assembly of objects in the outer solar system. These objects
are critical for understanding the currently unexplained transition from the
smallest Kuiper belt objects with densities lower than that of water to the
largest objects with significant rock content. Mapping this transition is made
difficult by the uncertainties in the diameters of these objects, which maps
into an even larger uncertainty in volume and thus density. The substantial
collecting area of the Atacama Large Millimeter Array allows significantly more
precise measurements of thermal emission from outer solar system objects and
could potentially greatly improve the density measurements. Here we use new
thermal observations of four objects with satellites to explore the
improvements possible with millimeter data. We find that effects due to
effective emissivity at millimeter wavelengths make it difficult to use the
millimeter data directly to find diameters and thus volumes for these bodies.
In addition, we find that when including the effects of model uncertainty, the
true uncertainties on the sizes of outer solar system objects measured with
radiometry are likely larger than those previously published. Substantial
improvement in object sizes will likely require precise occultation
measurements.Comment: AJ, in pres
Agricultural Tenure in England and Wales 2007
The report presents a repeat of a 1989-90 postal survey to explore the land tenurial changes in England and Wales that have resulted from legislative and structural change. Clearly, since 1990, the introduction of Farm Business Tenancies means that the two sets of results, while not directly comparable, allows the occupancy of land under unconventional forms of tenancy to be explored and contrasted. Furthermore, many factors influence the occupancy of land including taxation, inheritance laws, the profitability of farming, and structural and policy changes within the industry. Therefore, the occupancy of agricultural land in 2007 should be set against this backcloth of socio-political changes that impact upon the industry. Finally, this report is split into two sections, the first focuses on the occupation of land in England and Wales using weighted sample data, while the second explores some of the dynamics behind land tenure using the unweighted sample data.Land Tenure, Farm Business Tenancies, Agricultural Occupancy, Informal Tenure Agreements, Agricultural and Food Policy, Farm Management, Land Economics/Use,
The Brain in Business: The Case for Organisational Cognitive Neuroscience?
The application of cognitive neuroscientific techniques to understanding social behaviour has resulted in many discoveries. Yet advocates of the ‘social cognitive neuroscience’ approach maintain that it suffers from a number of limitations. The most notable of these is its distance from any form of real-world applicability. One solution to this limitation is ‘Organisational Cognitive Neuroscience’ – the study of the cognitive neuroscience of human behaviour in, and in response to, organizations. Given that all of us will spend most of our lives in some sort of work related organisation, organisational cognitive neuroscience allows us to examine the cognitive underpinnings of social behaviour that occurs in what may be our most natural ecology. Here we provide a brief overview of this approach, a definition and also some possible questions that the new approach would be best suited to address
The Darkest Shadows: Deep Mid-Infrared Extinction Mapping of a Massive Protocluster
We use deep Spitzer-IRAC imaging of a massive Infrared Dark Cloud
(IRDC) G028.37+00.07 to construct a Mid-Infrared (MIR) extinction map that
probes mass surface densities up to
(mag), amongst the highest values yet probed by extinction
mapping. Merging with a NIR extinction map of the region, creates a high
dynamic range map that reveals structures down to mag. We utilize
the map to: (1) Measure a cloud mass within a radius
of pc. CO kinematics indicate that the cloud is gravitationally
bound. It thus has the potential to form one of the most massive young star
clusters known in the Galaxy. (2) Characterize the structures of 16 massive
cores within the IRDC, finding they can be fit by singular polytropic spheres
with and . They have
--- relatively low values
that, along with their measured cold temperatures, suggest magnetic fields,
rather than accretion-powered radiative heating, are important for controlling
fragmentation of these cores. (3) Determine the (equivalently column
density or ) probability distribution function (PDF) for a region that is
near complete for mag. The PDF is well fit by a single log-normal with
mean mag, high compared to other known clouds. It does
not exhibit a separate high-end power law tail, which has been claimed to
indicate the importance of self-gravity. However, we suggest that the PDF does
result from a self-similar, self-gravitating hierarchy of structure being
present over a wide range of scales in the cloud.Comment: 6 pages, 3 figures, 1 table, accepted to ApJ
Economic Impact Assessment of Bovine Tuberculosis in the South West of England
Bovine TB (bTB) presents a significant challenge to beef and dairy farmers. In 2009 7,449 herds were subject to movement restrictions in Great Britain because of bTB. Of these, 52% were in South West England and 20% were in Devon alone. With over 25% of holdings with cattle in the South West likely to suffer a bTB breakdown within the course of a year, understanding the cost implications on farm businesses is vital in order to demonstrate the impact that this disease is having on agricultural communities and the agricultural economy. The research undertaken for this report has revealed considerable variation across a range of different types of costs associated with bTB. Consequently average figures, either for costs or calculating compensation, obscure much of the detail at an individual farm level. The research also points to a range of ‘hidden’ and longer term costs that fall beyond the scope of the compensation scheme. Finally, in addition to economic losses, bTB is imposing considerable costs on the personal well-being of many farm households and also raises profound livestock welfare issues.Bovine Tuberculosis, Costs, Beef farmers, Dairy farmers, Agricultural and Food Policy, Farm Management,
ALMA Thermal Observations of Europa
We present four daytime thermal images of Europa taken with the Atacama Large
Millimeter Array. Together, these images comprise the first spatially resolved
thermal dataset with complete coverage of Europa's surface. The resulting
brightness temperatures correspond to a frequency of 233 GHz (1.3 mm) and a
typical linear resolution of roughly 200 km. At this resolution, the images
capture spatially localized thermal variations on the scale of geologic and
compositional units. We use a global thermal model of Europa to simulate the
ALMA observations in order to investigate the thermal structure visible in the
data. Comparisons between the data and model images suggest that the
large-scale daytime thermal structure on Europa largely results from bolometric
albedo variations across the surface. Using bolometric albedos extrapolated
from Voyager measurements, a homogenous model reproduces these patterns well,
but localized discrepancies exist. These discrepancies can be largely explained
by spatial inhomogeneity of the surface thermal properties. Thus, we use the
four ALMA images to create maps of the surface thermal inertia and emissivity
at our ALMA wavelength. From these maps, we identify a region of either
particularly high thermal inertia or low emissivity near 90 degrees West and 23
degrees North, which appears anomalously cold in two of our images.Comment: 9 pages, 3 figures, accepted for publication in the Astronomical
Journa
More Negotiation and Less Demonstrations: The NAACP, SCLC, and Racial Conflict in Pensacola, 1970-1978
The civil rights movement is a topic that continues to inspire a tremendous amount of scholarly research. One topic that remains relatively unexplored, though, is the post-1960s struggle for black equality. Traditional narratives typically use the 1968 assassination of Rev. Dr. Martin Luther King, Jr. as their symbolic conclusion. Yet the fight against racial injustice continued beyond King\u27s death, and the next decade brought new issues for civil rights activists. One of the most fascinating concerns the role traditional organizations, particularIy the National Association for the Advancement of Colored People (NAACP) and the Southern Christian Leadership Conference (SCLC), played in local campaigns for black equality. Differences between the goals and tactics each used during campaigns of the 1960s have been well documented. However, the effect those differences had on grassroots campaigns beyond that tumultuous decade is a narrative largely untold. One struggle that illuminates the organizational conflict took place in northwest Florida during the mid-1970s
Zooming in to Massive Star Birth
We present high resolution (0.2", 1000 AU) 1.3 mm ALMA observations of
massive infrared dark cloud clump, G028.37+00.07-C1, thought to harbor the
early stages of massive star formation. Using (3-2) we resolve the
previously identified C1-S core, separating the bulk of its emission from two
nearby protostellar sources. C1-S is thus identified as a massive
(), compact (pc diameter) starless core, e.g., with
no signs of outflow activity. Being highly deuterated, this is a promising
candidate for a pre-stellar core on the verge of collapse. An analysis of its
dynamical state indicates a sub-virial velocity dispersion compared to a
trans-Alfv\'enic turbulent core model. However, virial equilibrium could be
achieved with sub-Alfv\'enic conditions involving mG magnetic field
strengths.Comment: 19 pages, 15 figures, 4 tables, accepted by Ap
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