1,212 research outputs found
Construction of an instrument for the measurement of educational philosophy
Thesis (M.Ed.)--Boston Universit
Recommended from our members
Of Mushrooms and Method: History and the Family in Hobbesâs Science of Politics
Hobbesâs account of the commonwealth is standardly interpreted to be primarily a theory of contract, whereby the archetypal manner of forming a political community is via an act of mutual agreement between suspicious individuals of equal power. By examining Hobbesâs theories of the pre-political family, and what he says about the role of real history in the development of political societies, I conclude that this standard interpretation is untenable. Rather, Hobbesâs conception of commonwealth âby institutionâ is a hypothetical model used to illustrate the mechanics of sovereignty, and to reconcile men to the conditions of subjection to absolute political power. In practice, all sovereignty is originally by âacquisitionâ. Realizing this casts serious doubt on the possibility that Hobbes is a fundamentally democratic thinker. In turn, we are invited to reconsider the history of political thought after Hobbes, in particular by seeing his theory of the family and of history as a genealogical ancestor of Scottish Enlightenment political theory.This work was supported by The Arts and Humanities Research Council block grant, and the University of Cambridge Faculty of History Prince Consort & Thirlwall Trust.This is the accepted manuscript version. The final version is available from http://ept.sagepub.com/content/early/2014/04/21/1474885114531237.abstract
Mass transport by buoyant bubbles in galaxy clusters
We investigate the effect of three important processes by which AGN-blown
bubbles transport material: drift, wake transport and entrainment. The first of
these, drift, occurs because a buoyant bubble pushes aside the adjacent
material, giving rise to a net upward displacement of the fluid behind the
bubble. For a spherical bubble, the mass of upwardly displaced material is
roughly equal to half the mass displaced by the bubble, and should be ~
10^{7-9} solar masses depending on the local ICM and bubble parameters. We show
that in classical cool core clusters, the upward displacement by drift may be a
key process in explaining the presence of filaments behind bubbles. A bubble
also carries a parcel of material in a region at its rear, known as the wake.
The mass of the wake is comparable to the drift mass and increases the average
density of the bubble, trapping it closer to the cluster centre and reducing
the amount of heating it can do during its ascent. Moreover, material dropping
out of the wake will also contribute to the trailing filaments. Mass transport
by the bubble wake can effectively prevent the build-up of cool material in the
central galaxy, even if AGN heating does not balance ICM cooling. Finally, we
consider entrainment, the process by which ambient material is incorporated
into the bubble. AbridgedComment: Accepted for publication in MNRAS. 17 pages, 4 figures, 2 tables.
Formatted for letter paper and adjusted author affiliations
Photoproduction of phi(1020) mesons on the proton at large momentum transfer
The cross section for meson photoproduction on the proton has been
measured for the first time up to a four-momentum transfer -t = 4 GeV^2, using
the CLAS detector at the Thomas Jefferson National Accelerator Facility. At low
four-momentum transfer, the differential cross section is well described by
Pomeron exchange. At large four-momentum transfer, above -t = 1.8 GeV^2, the
data support a model where the Pomeron is resolved into its simplest component,
two gluons, which may couple to any quark in the proton and in the .Comment: 5 pages; 7 figure
Garden and landscape-scale correlates of moths of differing conservation status: significant effects of urbanization and habitat diversity
Moths are abundant and ubiquitous in vegetated terrestrial environments and are pollinators, important herbivores of wild plants, and food for birds, bats and rodents. In recent years, many once abundant and widespread species have shown sharp declines that have been cited by some as indicative of a widespread insect biodiversity crisis. Likely causes of these declines include agricultural intensification, light pollution, climate change, and urbanization; however, the real underlying cause(s) is still open to conjecture. We used data collected from the citizen science Garden Moth Scheme (GMS) to explore the spatial association between the abundance of 195 widespread British species of moth, and garden habitat and landscape features, to see if spatial habitat and landscape associations varied for species of differing conservation status. We found that associations with habitat and landscape composition were species-specific, but that there were consistent trends in species richness and total moth abundance. Gardens with more diverse and extensive microhabitats were associated with higher species richness and moth abundance; gardens near to the coast were associated with higher richness and moth abundance; and gardens in more urbanized locations were associated with lower species richness and moth abundance. The same trends were also found for species classified as increasing, declining and vulnerable under IUCN (World Conservation Union) criteria
Investigating an Airborne Tularemia Outbreak, Germany
Infectious aerosols can contribute to the transmission of tularemia during processing of dead hares
The e p -> e' p eta reaction at and above the S11(1535) baryon resonance
New cross sections for the reaction e p -> ep eta are reported for total
center of mass energy W = 1.5--1.86 GeV and invariant momentum transfer Q^2 =
0.25--1.5 GeV^2. This large kinematic range allows extraction of important new
information about response functions, photocouplings, and eta N coupling
strengths of baryon resonances. Expanded W coverage shows sharp structure at W
\~ 1.7 GeV; this is shown to come from interference between S and P waves and
can be interpreted in terms of known resonances. Improved values are derived
for the photon coupling amplitude for the S11(1535) resonance.Comment: 11 pages, RevTeX, 5 figures, submitted to Phys. Rev. Let
Measurement of Inclusive Spin Structure Functions of the Deuteron
We report the results of a new measurement of spin structure functions of the
deuteron in the region of moderate momentum transfer ( = 0.27 -- 1.3
(GeV/c)) and final hadronic state mass in the nucleon resonance region (
= 1.08 -- 2.0 GeV). We scattered a 2.5 GeV polarized continuous electron beam
at Jefferson Lab off a dynamically polarized cryogenic solid state target
(ND) and detected the scattered electrons with the CEBAF Large
Acceptance Spectrometer (CLAS). From our data, we extract the longitudinal
double spin asymmetry and the spin structure function . Our
data are generally in reasonable agreement with existing data from SLAC where
they overlap, and they represent a substantial improvement in statistical
precision. We compare our results with expectations for resonance asymmetries
and extrapolated deep inelastic scaling results. Finally, we evaluate the first
moment of the structure function and study its approach to both the
deep inelastic limit at large and to the Gerasimov-Drell-Hearn sum rule
at the real photon limit (). We find that the first moment varies
rapidly in the range of our experiment and crosses zero at between
0.5 and 0.8 (GeV/c), indicating the importance of the resonance at
these momentum transfers.Comment: 13 pages, 8 figures, ReVTeX 4, final version as accepted by Phys.
Rev.
Observation of exclusive DVCS in polarized electron beam asymmetry measurements
We report the first results of the beam spin asymmetry measured in the
reaction e + p -> e + p + gamma at a beam energy of 4.25 GeV. A large asymmetry
with a sin(phi) modulation is observed, as predicted for the interference term
of Deeply Virtual Compton Scattering and the Bethe-Heitler process. The
amplitude of this modulation is alpha = 0.202 +/- 0.028. In leading-order and
leading-twist pQCD, the alpha is directly proportional to the imaginary part of
the DVCS amplitude.Comment: 6 pages, 5 figure
Deeply virtual and exclusive electroproduction of omega mesons
The exclusive omega electroproduction off the proton was studied in a large
kinematical domain above the nucleon resonance region and for the highest
possible photon virtuality (Q2) with the 5.75 GeV beam at CEBAF and the CLAS
spectrometer. Cross sections were measured up to large values of the
four-momentum transfer (-t < 2.7 GeV2) to the proton. The contributions of the
interference terms sigma_TT and sigma_TL to the cross sections, as well as an
analysis of the omega spin density matrix, indicate that helicity is not
conserved in this process. The t-channel pi0 exchange, or more generally the
exchange of the associated Regge trajectory, seems to dominate the reaction
gamma* p -> omega p, even for Q2 as large as 5 GeV2. Contributions of handbag
diagrams, related to Generalized Parton Distributions in the nucleon, are
therefore difficult to extract for this process. Remarkably, the high-t
behaviour of the cross sections is nearly Q2-independent, which may be
interpreted as a coupling of the photon to a point-like object in this
kinematical limit.Comment: 15 pages,19 figure
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