406 research outputs found
The Marti School Board Meeting Minutes November 2, 1960
Minutes from the Board Meeting of The Marti School discussing news and the status of a variety of issues related to curriculum, finance, scholarships, and more.https://corescholar.libraries.wright.edu/special_ms358_documents/1023/thumbnail.jp
Minutes of Marti School Board of Trustees September 7, 1960
Minutes from the Board of Trustees of The Marti School discussing status of the school, the addition of two new board members, the arrival of new faculty, and more.https://corescholar.libraries.wright.edu/special_ms358_documents/1022/thumbnail.jp
Fundamental Symmetries and Conservation Laws
I discuss recent progress in low-energy tests of symmetries and conservation
laws, including parity nonconservation in atoms and nuclei, electric dipole
moment tests of time-reversal invariance, beta-decay correlation studies, and
decays violating separate (family) and total lepton number.Comment: 11 pages, 5 figures; plenary talk presented at PANIC0
Nuclear Spin-Isospin Correlations, Parity Violation, and the Problem
The strong interaction effects of isospin- and spin-dependent nucleon-nucleon
correlations observed in many-body calculations are interpreted in terms of a
one-pion exchange mechanism. Including such effects in computations of nuclear
parity violating effects leads to enhancements of about 10%. A larger effect
arises from the one-boson exchange nature of the parity non-conserving nucleon-
nucleon interaction, which depends on both weak and strong meson-nucleon
coupling constants. Using values of the latter that are constrained by
nucleon-nucleon phase shifts leads to enhancements of parity violation by
factors close to two. Thus much of previously noticed discrepancies between
weak coupling constants extracted from different experiments can be removed.Comment: 8 pages 2 figures there should have been two figures in v
Combined effect of coherent Z exchange and the hyperfine interaction in atomic PNC
The nuclear spin-dependent parity nonconserving (PNC) interaction arising
from a combination of the hyperfine interaction and the coherent,
spin-independent, PNC interaction from Z exchange is evaluated using many-body
perturbation theory. For the 6s-7s transition in 133Cs, we obtain a result that
is about 40% smaller than that found previously by Bouchiat and Piketty [Phys.
Lett. B 269, 195 (1991)]. Applying this result to 133Cs, leads to an increase
in the experimental value of nuclear anapole moment and exacerbates differences
between constraints on PNC meson coupling constants obtained from the Cs
anapole moment and those obtained from other nuclear parity violating
experiments. Nuclear spin-dependent PNC dipole matrix elements, including
contributions from the combined weak-hyperfine interaction, are also given for
the 7s-8s transition in 211Fr and for transitions between ground-state
hyperfine levels in K, Rb, Cs, Ba+, Au, Tl, Fr, and Ra+.Comment: Revtex4 preprint 19 pages 4 table
The anapole moment and nucleon weak interactions
From the recent measurement of parity nonconservation (PNC) in the Cs atom we
have extracted the constant of the nuclear spin dependent electron-nucleon PNC
interaction, ; the anapole moment constant, ; the strength of the PNC proton-nucleus potential, ; the -meson-nucleon interaction constant,
; and the strength of the neutron-nucleus potential, .Comment: Uses RevTex, 12 pages. We have added an explanation of the effect of
finite nuclear siz
Theoretical study of incoherent phi photoproduction on a deuteron target
We study the photoproduction of phi mesons in deuteron, paying attention to
the modification of the cross section from bound protons to the free ones with
the aim of comparing with recent results at LEPS. For this purpose we take into
account Fermi motion in single scattering and rescattering of the phi to
account for phi absorption on a second nucleon as well as the rescattering of
the proton. We find that the contribution of the double scattering is much
smaller than the typical cross section of gamma p to phi p in free space, which
implies a very small screening of the phi production in deuteron. The
contribution from the proton rescattering, on the other hand, is found to be
not negligible compared to the cross section of gamma p to phi p in free space,
and leads to a moderate reduction of the phi photoproduction cross section on a
deuteron at forward angles if LEPS set up is taken into account. The Fermi
motion allows contribution of the single scattering in regions forbidden by
phase space in the free case. In particular, we find that for momentum
transferred squared close to the maximum value, the Fermi motion changes
drastically the shape of d sigma / dt, to the point that the ratio of this
cross section to the free one becomes very sensitive to the precise value of t
chosen, or the size of the bin used in an experimental analysis. Hence, this
particular region of t does not seem the most indicated to find effects of a
possible phi absorption in the deuteron. This reaction is studied theoretically
as a function of t and the effect of the experimental angular cuts at LEPS is
also discussed, providing guidelines for future experimental analyses of the
reaction.Comment: 17 pages, 16 figure
Sensitivity of deexcitation energies of superdeformed secondary minima to the density dependence of symmetry energy with the relativistic mean-field theory
The relationship between deexcitation energies of superdeformed secondary
minima relative to ground states and the density dependence of the symmetry
energy is investigated for heavy nuclei using the relativistic mean field (RMF)
model. It is shown that the deexcitation energies of superdeformed secondary
minima are sensitive to differences in the symmetry energy that are mimicked by
the isoscalar-isovector coupling included in the model. With deliberate
investigations on a few Hg isotopes that have data of deexcitation energies, we
find that the description for the deexcitation energies can be improved due to
the softening of the symmetry energy. Further, we have investigated
deexcitation energies of odd-odd heavy nuclei that are nearly independent of
pairing correlations, and have discussed the possible extraction of the
constraint on the density dependence of the symmetry energy with the
measurement of deexcitation energies of these nuclei.Comment: 14 pages, 3 figure
Mutation of Ser172 in Yeast β Tubulin Induces Defects in Microtubule Dynamics and Cell Division
Ser172 of β tubulin is an important residue that is mutated in a human brain disease and phosphorylated by the cyclin-dependent kinase Cdk1 in mammalian cells. To examine the role of this residue, we used the yeast S. cerevisiae as a model and produced two different mutations (S172A and S172E) of the conserved Ser172 in the yeast β tubulin Tub2p. The two mutants showed impaired cell growth on benomyl-containing medium and at cold temperatures, altered microtubule (MT) dynamics, and altered nucleus positioning and segregation. When cytoplasmic MT effectors Dyn1p or Kar9p were deleted in S172A and S172E mutants, cells were viable but presented increased ploidy. Furthermore, the two β tubulin mutations exhibited synthetic lethal interactions with Bik1p, Bim1p or Kar3p, which are effectors of cytoplasmic and spindle MTs. In the absence of Mad2p-dependent spindle checkpoint, both mutations are deleterious. These findings show the importance of Ser172 for the correct function of both cytoplasmic and spindle MTs and for normal cell division
Detecting Disengagement from HIV Care before It Is Too Late: Development and Preliminary Validation of a Novel Index of Engagement in HIV Care
Background:Engagement in care is critical to achieving and sustaining optimal benefits of efficacious antiretroviral therapies for HIV infection. Current metrics of engagement in care, including problematic patterns of retention in care, adherence to treatment, and viral suppression, are often detected late in the disengagement process. We sought to develop and validate a patient-centered screener of engagement in care that can be used to identify deficits in patient perceptions of engagement before the development of poor outcomes, including loss to follow-up, treatment nonadherence, virologic failure, and the resulting increased likelihood of HIV-associated morbidity and mortality and onward transmission of HIV.Setting and Methods:Using input from patients, providers, and researchers through in-person focus groups and an online Delphi process, we developed a self-report measure of engagement in care that was validated with 3296 patients from 7 clinics across the United States.Results:Results supported a single dimension of engagement in care measured by 10 items. Lower scores on the HIV Index were related to higher depression and anxiety symptoms, greater use of alcohol and stimulants, and increased likelihood of reporting internalized HIV stigma. Higher Index scores were positively associated with self-report measures of antiretroviral therapy adherence, corroborative clinic records documenting appointment attendance, and increased likelihood of recent viral load suppression.Conclusions:The HIV Index offers promise as a patient-centered diagnostic and prognostic screener for engagement in care that can be used to trigger interventions to promote better clinical outcomes for persons living with HIV
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