360 research outputs found
Probing the isovector transition strength of the low-lying nuclear excitations induced by inverse kinematics proton scattering
A compact approach based on the folding model is suggested for the
determination of the isoscalar and isovector transition strengths of the
low-lying () excitations induced by inelastic proton
scattering measured with exotic beams. Our analysis of the recently measured
inelastic O+p scattering data at and 43 MeV/nucleon
has given for the first time an accurate estimate of the isoscalar
and isovector deformation parameters (which cannot be determined from
the (p,p') data alone by standard methods) for 2 and excited
states in O. Quite strong isovector mixing was found in the 2
inelastic O+p scattering channel, where the strength of the isovector
form factor (prototype of the Lane potential) corresponds to a
value almost 3 times larger than and a ratio of nuclear transition
matrix elements .Comment: 5 pages, 3 figure
Solar Neutrinos with Three Flavor Mixings
The recent 71Ga solar neutrino observation is combined with the 37Cl and
Kamiokande-II observations in an analysis for neutrino masses and mixings. The
allowed parameter region is found for matter enhanced mixings among all three
neutrino flavors. Distortions of the solar neutrino spectrum unique to three
flavors are possible and may be observed in continuing and next generation
experiments.Comment: August 1992 (Revised) PURD-TH-92-
Transverse Wave Propagation in Relativistic Two-fluid Plasmas in de Sitter Space
We investigate transverse electromagnetic waves propagating in a plasma in
the de Sitter space. Using the 3+1 formalism we derive the relativistic
two-fluid equations to take account of the effects due to the horizon and
describe the set of simultaneous linear equations for the perturbations. We use
a local approximation to investigate the one-dimensional radial propagation of
Alfv\'en and high frequency electromagnetic waves and solve the dispersion
relation for these waves numerically.Comment: 19 pages, 12 figure
Dimensionless cosmology
Although it is well known that any consideration of the variations of
fundamental constants should be restricted to their dimensionless combinations,
the literature on variations of the gravitational constant is entirely
dimensionful. To illustrate applications of this to cosmology, we explicitly
give a dimensionless version of the parameters of the standard cosmological
model, and describe the physics of Big Bang Neucleosynthesis and recombination
in a dimensionless manner. The issue that appears to have been missed in many
studies is that in cosmology the strength of gravity is bound up in the
cosmological equations, and the epoch at which we live is a crucial part of the
model. We argue that it is useful to consider the hypothetical situation of
communicating with another civilization (with entirely different units),
comparing only dimensionless constants, in order to decide if we live in a
Universe governed by precisely the same physical laws. In this thought
experiment, we would also have to compare epochs, which can be defined by
giving the value of any {\it one} of the evolving cosmological parameters. By
setting things up carefully in this way one can avoid inconsistent results when
considering variable constants, caused by effectively fixing more than one
parameter today. We show examples of this effect by considering microwave
background anisotropies, being careful to maintain dimensionlessness
throughout. We present Fisher matrix calculations to estimate how well the fine
structure constants for electromagnetism and gravity can be determined with
future microwave background experiments. We highlight how one can be misled by
simply adding to the usual cosmological parameter set
On the verge of Umdeutung in Minnesota: Van Vleck and the correspondence principle (Part One)
In October 1924, the Physical Review, a relatively minor journal at the time,
published a remarkable two-part paper by John H. Van Vleck, working in virtual
isolation at the University of Minnesota. Van Vleck combined advanced
techniques of classical mechanics with Bohr's correspondence principle and
Einstein's quantum theory of radiation to find quantum analogues of classical
expressions for the emission, absorption, and dispersion of radiation. For
modern readers Van Vleck's paper is much easier to follow than the famous paper
by Kramers and Heisenberg on dispersion theory, which covers similar terrain
and is widely credited to have led directly to Heisenberg's "Umdeutung" paper.
This makes Van Vleck's paper extremely valuable for the reconstruction of the
genesis of matrix mechanics. It also makes it tempting to ask why Van Vleck did
not take the next step and develop matrix mechanics himself.Comment: 82 page
Improving Access to Primary and Pain Care for Patients Taking Opioids for Chronic Pain in Michigan: Recommendations from an Expert Panel
This multidisciplinary expert panel was convened to generate recommendations to address the limited access to care that patients experience when taking opioids for chronic pain. Recent policies and guidelines instituted to reduce inappropriate opioid prescribing have had unintended consequences for the 5-8 million patients taking long-term opioid therapy for chronic pain in the U.S. As providers discontinue prescribing and turn away patients dependent on opioids, this population faces limited access to both primary and pain-related care. The root causes of this access issue can be attributed to several overarching barriers, including new opioid-related policies, payment models, a lack of care coordination, stigma, and racial biases.
Over multiple rounds of deliberation, the panel brainstormed possible solutions, considering feasibility, impact, and importance, and ultimately ranked their final recommendations in order of implementation priority. The final list included 11 recommendations, from which three overarching themes emerged:
1. Improving care models to better support patients with chronic pain
Three recommendations involved improving care models, including the top two: increasing reimbursement for the time needed to treat complex chronic pain and establishing coordinated care models that bundle payments for multimodal pain treatment.
2. Enhancing provider education and training
Four recommendations involving provider education efforts received slightly lower rankings and included training on biopsychosocial factors of pain care and clarifying the continuum between physical dependency and opioid use disorder.
3. Implementing practices to reduce racial biases and inequities
The remaining four recommendations address racial biases and inequities, ranging from standardizing pain management protocols to reduce bias to increasing recruitment and retention of providers from underrepresented racial minorities.
Throughout the process, panelists emphasized the interconnectedness of their proposed solutions, and indicated that multiple approaches are likely needed to meaningfully improve access to care for this patient population. Importantly, though this panel was convened in Michigan, and its expertise grounded in Michigan’s healthcare ecosystem, there are millions of patients taking opioids for chronic pain across the country, and reports of limited access to care are not unique to Michigan. Consequently, there may also be opportunity to apply these recommendations more broadly, in other states and at multiple levels of the United States healthcare system.This research was funded by the Michigan Health Endowment Fund (grant # R-1808-143371).http://deepblue.lib.umich.edu/bitstream/2027.42/168420/1/Lagisetty - Improving Access to Care for Patients Taking Opioids - 2021.pdfDescription of Lagisetty - Improving Access to Care for Patients Taking Opioids - 2021.pdf : White PaperSEL
Effect of Lanadelumab Compared with Placebo on Prevention of Hereditary Angioedema Attacks : a Randomized Clinical Trial
Importance: Current treatments for long-term prophylaxis in hereditary angioedema have limitations. Objective: To assess the efficacy of lanadelumab, a fully human monoclonal antibody that selectively inhibits active plasma kallikrein, in preventing hereditary angioedema attacks. Design, Setting, and Participants: Phase 3, randomized, double-blind, parallel-group, placebo-controlled trial conducted at 41 sites in Canada, Europe, Jordan, and the United States. Patients were randomized between March 3, 2016, and September 9, 2016; last day of follow-up was April 13, 2017. Randomization was 2:1 lanadelumab to placebo; patients assigned to lanadelumab were further randomized 1:1:1 to 1 of the 3 dose regimens. Patients 12 years or older with hereditary angioedema type I or II underwent a 4-week run-in period and those with 1 or more hereditary angioedema attacks during run-in were randomized. Interventions: Twenty-six-week treatment with subcutaneous lanadelumab 150 mg every 4 weeks (n = 28), 300 mg every 4 weeks (n = 29), 300 mg every 2 weeks (n = 27), or placebo (n = 41). All patients received injections every 2 weeks, with those in the every-4-week group receiving placebo in between active treatments. Main Outcome and Measures: Primary efficacy end point was the number of investigator-confirmed attacks of hereditary angioedema over the treatment period. Results: Among 125 patients randomized (mean age, 40.7 years [SD, 14.7 years]; 88 females [70.4%]; 113 white [90.4%]), 113 (90.4%) completed the study. During the run-in period, the mean number of hereditary angioedema attacks per month in the placebo group was 4.0; for the lanadelumab groups, 3.2 for the every-4-week 150-mg group; 3.7 for the every-4-week 300-mg group; and 3.5 for the every-2-week 300-mg group. During the treatment period, the mean number of attacks per month for the placebo group was 1.97; for the lanadelumab groups, 0.48 for the every-4-week 150-mg group; 0.53 for the every-4-week 300-mg group; and 0.26 for the every-2-week 300-mg group. Compared with placebo, the mean differences in the attack rate per month were -1.49 (95% CI, -1.90 to -1.08; P <.001); -1.44 (95% CI, -1.84 to -1.04; P <.001); and -1.71 (95% CI, -2.09 to -1.33; P <.001). The most commonly occurring adverse events with greater frequency in the lanadelumab treatment groups were injection site reactions (34.1% placebo, 52.4% lanadelumab) and dizziness (0% placebo, 6.0% lanadelumab). Conclusions and Relevance: Among patients with hereditary angioedema type I or II, treatment with subcutaneous lanadelumab for 26 weeks significantly reduced the attack rate compared with placebo. These findings support the use of lanadelumab as a prophylactic therapy for hereditary angioedema. Further research is needed to determine long-term safety and efficacy. Trial Registration: EudraCT Identifier: 2015-003943-20; ClinicalTrials.gov Identifier: NCT02586805
Constraining Strong Baryon-Dark Matter Interactions with Primordial Nucleosynthesis and Cosmic Rays
Self-interacting dark matter (SIDM) was introduced by Spergel & Steinhardt to
address possible discrepancies between collisionless dark matter simulations
and observations on scales of less than 1 Mpc. We examine the case in which
dark matter particles not only have strong self-interactions but also have
strong interactions with baryons. The presence of such interactions will have
direct implications for nuclear and particle astrophysics. Among these are a
change in the predicted abundances from big bang nucleosynthesis (BBN) and the
flux of gamma-rays produced by the decay of neutral pions which originate in
collisions between dark matter and Galactic cosmic rays (CR). From these
effects we constrain the strength of the baryon--dark matter interactions
through the ratio of baryon - dark matter interaction cross section to dark
matter mass, . We find that BBN places a weak upper limit to this ratio . CR-SIDM interactions, however, limit the possible DM-baryon cross
section to ; this rules out an energy-independent
interaction, but not one which falls with center-of-mass velocity as or steeper.Comment: 17 pages, 2 figures; plain LaTeX. To appear in PR
DES13S2cmm: the first superluminous supernova from the Dark Energy Survey
We present DES13S2cmm, the first spectroscopically-confirmed superluminous
supernova (SLSN) from the Dark Energy Survey (DES). We briefly discuss the data
and search algorithm used to find this event in the first year of DES
operations, and outline the spectroscopic data obtained from the European
Southern Observatory (ESO) Very Large Telescope to confirm its redshift (z =
0.663 +/- 0.001 based on the host-galaxy emission lines) and likely spectral
type (type I). Using this redshift, we find M_U_peak = -21.05 +0.10 -0.09 for
the peak, rest-frame U-band absolute magnitude, and find DES13S2cmm to be
located in a faint, low metallicity (sub-solar), low stellar-mass host galaxy
(log(M/M_sun) = 9.3 +/- 0.3); consistent with what is seen for other SLSNe-I.
We compare the bolometric light curve of DES13S2cmm to fourteen similarly
well-observed SLSNe-I in the literature and find it possesses one of the
slowest declining tails (beyond +30 days rest frame past peak), and is the
faintest at peak. Moreover, we find the bolometric light curves of all SLSNe-I
studied herein possess a dispersion of only 0.2-0.3 magnitudes between +25 and
+30 days after peak (rest frame) depending on redshift range studied; this
could be important for 'standardising' such supernovae, as is done with the
more common type Ia. We fit the bolometric light curve of DES13S2cmm with two
competing models for SLSNe-I - the radioactive decay of 56Ni, and a magnetar -
and find that while the magnetar is formally a better fit, neither model
provides a compelling match to the data. Although we are unable to conclusively
differentiate between these two physical models for this particular SLSN-I,
further DES observations of more SLSNe-I should break this degeneracy,
especially if the light curves of SLSNe-I can be observed beyond 100 days in
the rest frame of the supernova.Comment: Accepted by MNRAS (2015 January 23), 13 pages, 6 figures, 2 table
Limits on and Oscillations from a Precision Measurement of Neutrino-Nucleon Neutral Current Interactions
We present limits on and
oscillations based on a study of
inclusive interactions performed using the CCFR massive coarse grained
detector in the FNAL Tevatron Quadrupole Triplet neutrino beam. The sensitivity
to oscillations is from the difference in the longitudinal energy deposition
pattern of versus or charged current
interactions. The energies ranged from 30 to 500 GeV with a mean of
140 GeV. The minimum and maximum flight lengths are 0.9 km and 1.4 km
respectively. For oscillations, the lowest 90% confidence
upper limit in of is obtained at ~eV. This result is the most stringent limit to date for
eV. For oscillations, the lowest 90%
confidence upper limit in of is obtained at
~eV. This result is the most stringent limit to date for
eV, and also excludes at 90% confidence much of the
high region favored by the recent LSND observation.Comment: Revised version contains limit on oscillations as
well as limit on oscillations found in original. 15
pages, ReVTeX, 3 figures in uuencoded file, submitted to PR
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