174 research outputs found
A social constructivist approach to introducing skills for employment to Foundation Degree students
Expectations for higher education providers to produce graduates ready for the workplace have shaped provision, with the introduction of the Foundation Degree, and expectations of an employability component within higher education programmes. This paper reports on an intervention for three groups of foundation degree students, which introduces them to ideas of skills for employability. An initial evaluation was followed up two months later exploring the longer-term impact and connections within students' programmes of study and data were captured from employers and tutors supporting this intervention. In agreement with similar studies, benefits for students were identified. However, this research reinforces the challenging nature of the employability agenda, particularly within the context of Foundation Degrees and their dual vocational-academic remit. This paper suggests there is a case to be made for a social constructivist approach within programmes and institutions for promoting awareness and consistency in developing student employability skills. © 2013 © 2013 Further Education Research Association
MRI measures of middle cerebral artery diameter in conscious humans during simulated orthostasis.
BACKGROUND AND PURPOSE: The relationship between middle cerebral artery (MCA) flow velocity (CFV) and cerebral blood flow (CBF) is uncertain because of unknown vessel diameter response to physiological stimuli. The purpose of this study was to directly examine the effect of a simulated orthostatic stress (lower body negative pressure [LBNP]) as well as increased or decreased end-tidal carbon dioxide partial pressure (P(ET)CO(2)) on MCA diameter and CFV.
METHODS: Twelve subjects participated in a CO(2) manipulation protocol and/or an LBNP protocol. In the CO(2) manipulation protocol, subjects breathed room air (normocapnia) or 6% inspired CO(2) (hypercapnia), or they hyperventilated to approximately 25 mm Hg P(ET)CO(2) (hypocapnia). In the LBNP protocol, subjects experienced 10 minutes each of -20 and -40 mm Hg lower body suction. CFV and diameter of the MCA were measured by transcranial Doppler and MRI, respectively, during the experimental protocols.
RESULTS: Compared with normocapnia, hypercapnia produced increases in both P(ET)CO(2) (from 36+/-3 to 40+/-4 mm Hg, P
CONCLUSIONS: Under the conditions of this study, changes in MCA diameter were not detected. Therefore, we conclude that relative changes in CFV were representative of changes in CBF during the physiological stimuli of moderate LBNP or changes in P(ET)CO(2)
Phenomenology of the Deuteron Electromagnetic Form Factors
A rigorous extraction of the deuteron charge form factors from tensor
polarization data in elastic electron-deuteron scattering, at given values of
the 4-momentum transfer, is presented. Then the world data for elastic
electron-deuteron scattering is used to parameterize, in three different ways,
the three electromagnetic form factors of the deuteron in the 4-momentum
transfer range 0-7 fm^-1. This procedure is made possible with the advent of
recent polarization measurements. The parameterizations allow a
phenomenological characterization of the deuteron electromagnetic structure.
They can be used to remove ambiguities in the form factors extraction from
future polarization data.Comment: 18 pages (LaTeX), 2 figures Feb. 25: minor changes of content and in
Table
A Comparison of Polarization Observables in Electron Scattering from the Proton and Deuteron
Recoil proton polarization observables were measured for both the p(,e) and d(,en reactions at two values of Q using a newly commissioned proton
Focal Plane Polarimeter at the M.I.T.-Bates Linear Accelerator Center. The
hydrogen and deuterium spin-dependent observables and
, the induced polarization and the form factor ratio
were measured under identical kinematics. The deuterium and
hydrogen results are in good agreement with each other and with the plane-wave
impulse approximation (PWIA).Comment: 9 pages, 1 figure; accepted by Phys. Rev. Let
A precise measurement of the deuteron elastic structure function A(Q^2)
The A(Q^2) structure function in elastic electron-deuteron scattering was
measured at six momentum transfers Q^2 between 0.66 and 1.80 (GeV/c)^2 in Hall
C at Jefferson Laboratory. The scattered electrons and recoil deuterons were
detected in coincidence, at a fixed deuteron angle of 60.5 degrees. These new
precise measurements resolve discrepancies between older sets of data. They put
significant constraints on existing models of the deuteron electromagnetic
structure, and on the strength of isoscalar meson exchange currents.Comment: 3 LaTeX pages plus 2 PS figure
Measurement of Tensor Polarization in Elastic Electron-Deuteron Scattering at Large Momentum Transfer
Tensor polarization observables (t20, t21 and t22) have been measured in
elastic electron-deuteron scattering for six values of momentum transfer
between 0.66 and 1.7 (GeV/c)^2. The experiment was performed at the Jefferson
Laboratory in Hall C using the electron HMS Spectrometer, a specially designed
deuteron magnetic channel and the recoil deuteron polarimeter POLDER. The new
data determine to much larger Q^2 the deuteron charge form factors G_C and G_Q.
They are in good agreement with relativistic calculations and disagree with
pQCD predictions.Comment: 5 pages, 4 figures, for associated informations, see
http://isnwww.in2p3.fr/hadrons/t20/t20_ang.html clarification about several
topics, one figure has been had, extraction of form factors use AQ
interpolation in our Q2 range onl
Major range extension for Orange-fronted Plushcrown Metopothrix aurantiaca in the central Amazon of Brazil
Orange-fronted Plushcrown Metopothrix aurantiaca is a unique, but easily overlooked, small furnariid found in the midstorey and canopy of riverine areas in the Amazon. The species' previously published distribution includes parts of southernmost Colombia, eastern Ecuador, eastern Peru, northern Bolivia and western Brazil. In the easternmost part of its distribution (Brazil), M. aurantiaca occurs in the states of Acre, Amazonas and Rondônia, east to 64°W. We present nine new records of the species in Brazil, all of them east of its previously known distribution and together extending the range by c.750 km. These new records derive from sampling that includes collecting expeditions, exhaustive várzea surveys, and incidental observations. We propose a new continuous distribution for this species restricted to white-water river floodplains with known occurrences. © 2019 The Authors
Virtual Compton Scattering and the Generalized Polarizabilities of the Proton at Q^2=0.92 and 1.76 GeV^2
Virtual Compton Scattering (VCS) on the proton has been studied at Jefferson
Lab using the exclusive photon electroproduction reaction (e p --> e p gamma).
This paper gives a detailed account of the analysis which has led to the
determination of the structure functions P_LL-P_TT/epsilon and P_LT, and the
electric and magnetic generalized polarizabilities (GPs) alpha_E(Q^2) and
beta_M(Q^2) at values of the four-momentum transfer squared Q^2= 0.92 and 1.76
GeV^2. These data, together with the results of VCS experiments at lower
momenta, help building a coherent picture of the electric and magnetic GPs of
the proton over the full measured Q^2-range, and point to their non-trivial
behavior.Comment: version 2: modified according to PRC Editor's and Referee's
recommendations. Archival paper for the E93-050 experiment at JLab Hall A. 28
pages, 23 figures, 5 cross-section tables. To be submitted to Phys.Rev.
Measurements of Deuteron Photodisintegration up to 4.0 GeV
The first measurements of the differential cross section for the d(gamma,p)n
reaction up to 4.0 GeV were performed at Continuous Electron Beam Accelerator
Facility (CEBAF) at Jefferson Lab. We report the cross sections at the proton
center-of-mass angles of 36, 52, 69 and 89 degrees. These results are in
reasonable agreement with previous measurements at lower energy. The 89 and 69
degree data show constituent-counting-rule behavior up to 4.0 GeV photon
energy. The 36 and 52 degree data disagree with the counting rule behavior. The
quantum chromodynamics (QCD) model of nuclear reactions involving reduced
amplitudes disagrees with the present data.Comment: 5 pages (REVTeX), 1 figure (postscript
Measurement of the Induced Proton Polarization P_n in the 12C(e,e'\vec{p}) Reaction
The first measurements of the induced proton polarization, P_n, for the 12C
(e,e'\vec{p}) reaction are reported. The experiment was performed at quasifree
kinematics for energy and momentum transfer (\omega,q) \approx (294 MeV, 756
MeV/c) and sampled a recoil momentum range of 0-250 MeV/c. The induced
polarization arises from final-state interactions and for these kinematics is
dominated by the real part of the spin-orbit optical potential. The
distorted-wave impulse approximation provides good agreement with data for the
1p_{3/2} shell. The data for the continuum suggest that both the 1s_{1/2} shell
and underlying l > 1 configurations contribute.Comment: 5 pages LaTeX, 2 postscript figures, accepted by Physical Reveiw
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