1,745 research outputs found
Assessing Learning-Centered Leadership: Connections to Research, Professional Standards, and Current Practices
Describes an assessment model designed to evaluate school leaders' performance. Unlike existing tools, this new system will assess both individuals and teams, and focuses specifically on instructional leadership and behaviors that improve learning
Bone and cartilage in osteoarthritis: is what's best for one good or bad for the other?
The interest in the relationship between articular cartilage and the structural and functional properties of peri-articular bone relates to the intimate contact that exists between these tissues in joints that are susceptible to the development of osteoarthritis (OA). The demonstration in several animal models that osteoporosis and decreased bone tissue modulus leads to an increased propensity for the development of post-traumatic OA is paradoxical in light of the extensive epidemiological literature indicating that individuals with high systemic bone mass, assessed by bone mineral density, are at increased risk for OA. These observations underscore the need for further studies to define the pathophysiological mechanisms involved in the interaction between subchondral bone and articular cartilage and for applying this information to the development of therapeutic interventions to improve the outcomes in patients with OA
Benchmark calculations for elastic fermion-dimer scattering
We present continuum and lattice calculations for elastic scattering between
a fermion and a bound dimer in the shallow binding limit. For the continuum
calculation we use the Skorniakov-Ter-Martirosian (STM) integral equation to
determine the scattering length and effective range parameter to high
precision. For the lattice calculation we use the finite-volume method of
L\"uscher. We take into account topological finite-volume corrections to the
dimer binding energy which depend on the momentum of the dimer. After
subtracting these effects, we find from the lattice calculation kappa a_fd =
1.174(9) and kappa r_fd = -0.029(13). These results agree well with the
continuum values kappa a_fd = 1.17907(1) and kappa r_fd = -0.0383(3) obtained
from the STM equation. We discuss applications to cold atomic Fermi gases,
deuteron-neutron scattering in the spin-quartet channel, and lattice
calculations of scattering for nuclei and hadronic molecules at finite volume.Comment: 16 pages, 5 figure
A quotient of the Lubin-Tate tower II
In this article we construct the quotient M_1/P(K) of the infinite-level
Lubin-Tate space M_1 by the parabolic subgroup P(K) of GL(n,K) of block form
(n-1,1) as a perfectoid space, generalizing results of one of the authors (JL)
to arbitrary n and K/Q_p finite. For this we prove some perfectoidness results
for certain Harris-Taylor Shimura varieties at infinite level. As an
application of the quotient construction we show a vanishing theorem for
Scholze's candidate for the mod p Jacquet-Langlands and the mod p local
Langlands correspondence. An appendix by David Hansen gives a local proof of
perfectoidness of M_1/P(K) when n = 2, and shows that M_1/Q(K) is not
perfectoid for maximal parabolics Q not conjugate to P.Comment: with an appendix by David Hanse
A new measurement of the 7Li(d,p)8Li cross section and consequences for 7Be(p,gamma)8B
A novel scheme for measuring the cross section of the 7Be(p,gamma)8B
reaction, the major source of high energy neutrinos from t he sun, is
presented. The scheme involves a strictly uniform particle beam and overcomes
some of the recognized experimental uncertainties of previous measurements. A
new measurement of sigma[7Li(d,p)8Li] has been carried out using this setup,and
the present value of sigma[7Li(d,p)8Li] = 155(8) mbarn at the top of the
E_d(lab.)= 776 keV resonance is compared to previous measurements. A new issue
regarding both the (d,p) and (p,gamma) reactions has been examined:
reaction-product nuclei which are backscattered out of the target. Measurements
and simulations carried out in the course of this investigation are presented
and discussed in the context of possible effects on the measured cross sections
of these reactions.Comment: 4 figure
Angular Correlations in Internal Pair Conversion of Aligned Heavy Nuclei
We calculate the spatial correlation of electrons and positrons emitted by
internal pair conversion of Coulomb excited nuclei in heavy ion collisions. The
alignment or polarization of the nucleus results in an anisotropic emission of
the electron-positron pairs which is closely related to the anisotropic
emission of -rays. However, the angular correlation in the case of
internal pair conversion exhibits diverse patterns. This might be relevant when
investigating atomic processes in heavy-ion collisions performed at the Coulomb
barrier.Comment: 27 pages + 6 eps figures, uses revtex.sty and epsf.sty,
tar-compressed and uuencoded with uufile
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