465 research outputs found
Thermally-induced expansion in the 8 GeV/c + Au reaction
Fragment kinetic energy spectra for reactions induced by 8.0 GeV/c
beams incident on a Au target have been analyzed in
order to deduce the possible existence and influence of thermal expansion. The
average fragment kinetic energies are observed to increase systematically with
fragment charge but are nearly independent of excitation energy. Comparison of
the data with statistical multifragmentation models indicates the onset of
extra collective thermal expansion near an excitation energy of E*/A
5 MeV. However, this effect is weak relative to the radial
expansion observed in heavy-ion-induced reactions, consistent with the
interpretation that the latter expansion may be driven primarily by dynamical
effects such as compression/decompression.Comment: 12 pages including 4 postscript figure
Estimating the impact of wide scale uptake of screening and medications for opioid use disorder in US prisons and jails
Background: Medications for opioid use disorder (OUD) are the most effective treatment for OUD, but uptake of these life-saving medications has been extremely limited in US prisons and jail settings, and limited data are available to guide policy decisions. The objective of this study was to estimate the impact of screening and treatment with medications for OUD in US prisons and jails on post-release opioid-related mortality. Methods: We used data from the National Center for Vital Statistics, the Bureau of Justice Statistics, and relevant literature to construct Monte Carlo simulations of a counterfactual scenario in which wide scale uptake of screening and treatment with medications for OUD occurred in US prisons and jails in 2016. Results: Our model predicted that 1840 (95% Simulation Interval [SI]: -2757 – 4959) lives would have been saved nationally if all persons who were clinically indicated had received medications for OUD while incarcerated. The model also predicted that approximately 4400 (95% SI: 2675 – 5557) lives would have been saved nationally if all persons who were clinically indicated had received medications for OUD while incarcerated and were retained in treatment post-release. These estimates correspond to 668 (95% SI: -1008 – 1812) and 1609 (95% SI: 972 – 2037) lives saved per 10,000 persons incarcerated, respectively. Conclusions: Prison and jail-based programs that comprehensively screen and provide treatment with medications for OUD have the potential to produce substantial reductions in opioid-related overdose deaths in a high-risk population; however, retention on treatment post-release is a key driver of population level impact
Induced Parity Nonconserving Interaction and Enhancement of Two-Nucleon Parity Nonconserving Forces
Two-nucleon parity nonconserving (PNC) interaction induced by the
single-particle PNC weak potential and the two-nucleon residual strong
interaction is considered. An approximate analytical formula for this Induced
PNC Interaction (IPNCI) between proton and neutron is derived (), and the
interaction constant is estimated. As a result of coherent contributions from
the nucleons to the PNC potential, IPNCI is an order of magnitude stronger
() than the residual weak two-nucleon interaction and has a
different coordinate and isotopic structure (e.g., the strongest part of IPNCI
does not contribute to the PNC mean field). IPNCI plays an important role in
the formation of PNC effects, e.g., in neutron-nucleus reactions. In that case,
it is a technical way to take into account the contribution of the distant
(small) components of a compound state which dominates the result. The absence
of such enhancement () in the case of T- and P-odd interaction
completes the picture.Comment: Phys. Rev. C, to appear; 17 pages, revtex 3, no figure
First Observation of Coherent Production in Neutrino Nucleus Interactions with 2 GeV
The MiniBooNE experiment at Fermilab has amassed the largest sample to date
of s produced in neutral current (NC) neutrino-nucleus interactions at
low energy. This paper reports a measurement of the momentum distribution of
s produced in mineral oil (CH) and the first observation of coherent
production below 2 GeV. In the forward direction, the yield of events
observed above the expectation for resonant production is attributed primarily
to coherent production off carbon, but may also include a small contribution
from diffractive production on hydrogen. Integrated over the MiniBooNE neutrino
flux, the sum of the NC coherent and diffractive modes is found to be (19.5
1.1 (stat) 2.5 (sys))% of all exclusive NC production at
MiniBooNE. These measurements are of immediate utility because they quantify an
important background to MiniBooNE's search for
oscillations.Comment: Submitted to Phys. Lett.
Twenty Years of the Polyvinyl Chloride Sustainability Challenges
Intense campaigning pressure on the UK PVC sector up to the late 1990s forced strategic engagement with sustainable development. Simplified outcomes from a detailed, consensus-based analysis by science-based NGO The Natural Step (TNS) took the form of five TNS Sustainability Challenges for PVC published in 2000. UK manufacturing companies initially used these Challenges to direct strategic progress. The Challenges have since been progressively taken up across European PVC value chains. The VinylPlus® programme uses an updated version of the five Challenges as a basis for voluntary commitments and transparent auditing of progress against published targets. Initial framing of the five TNS Sustainability Challenges for PVC were drafted consciously for generic relevance to other materials. Assessing the sustainability performance of some alternative materials to PVC against the five Sustainability Challenges reveals different sustainability performance in a range of potential applications. This highlights the danger inherent in automatic selection or deselection of materials in the absence of assessment of options on a ‘level playing field’ of sustainability principles. The five TNS Sustainability Challenges for PVC remain valid today and into the longer-term future as a basis for making stepwise, profitable progress towards the goal of sustainability for PVC and other materials
Probing exotic phenomena at the interface of nuclear and particle physics with the electric dipole moments of diamagnetic atoms: A unique window to hadronic and semi-leptonic CP violation
The current status of electric dipole moments of diamagnetic atoms which
involves the synergy between atomic experiments and three different theoretical
areas -- particle, nuclear and atomic is reviewed. Various models of particle
physics that predict CP violation, which is necessary for the existence of such
electric dipole moments, are presented. These include the standard model of
particle physics and various extensions of it. Effective hadron level combined
charge conjugation (C) and parity (P) symmetry violating interactions are
derived taking into consideration different ways in which a nucleon interacts
with other nucleons as well as with electrons. Nuclear structure calculations
of the CP-odd nuclear Schiff moment are discussed using the shell model and
other theoretical approaches. Results of the calculations of atomic electric
dipole moments due to the interaction of the nuclear Schiff moment with the
electrons and the P and time-reversal (T) symmetry violating
tensor-pseudotensor electron-nucleus are elucidated using different
relativistic many-body theories. The principles of the measurement of the
electric dipole moments of diamagnetic atoms are outlined. Upper limits for the
nuclear Schiff moment and tensor-pseudotensor coupling constant are obtained
combining the results of atomic experiments and relativistic many-body
theories. The coefficients for the different sources of CP violation have been
estimated at the elementary particle level for all the diamagnetic atoms of
current experimental interest and their implications for physics beyond the
standard model is discussed. Possible improvements of the current results of
the measurements as well as quantum chromodynamics, nuclear and atomic
calculations are suggested.Comment: 46 pages, 19 tables and 16 figures. A review article accepted for
EPJ
Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events
The - oscillation frequency has been measured with a sample of
23 million \B\bar B pairs collected with the BABAR detector at the PEP-II
asymmetric B Factory at SLAC. In this sample, we select events in which both B
mesons decay semileptonically and use the charge of the leptons to identify the
flavor of each B meson. A simultaneous fit to the decay time difference
distributions for opposite- and same-sign dilepton events gives ps.Comment: 7 pages, 1 figure, submitted to Physical Review Letter
Abacavir, efavirenz, didanosine, with or without hydroxyurea, in HIV-infected adults failing initial nucleoside/protease inhibitor-containing regimens
Background: Hydroxyurea (HU) is an immunomodulatory agent that has been documented to enhance the antiretroviral activity of nucleoside reverse transcriptase inhibitors, such as abacavir (ABC) and didanosine (ddI), and would be expected to improve virologic efficacy. Methods: A 48-week, phase IV, multicenter, open-label, proof-of-concept clinical trial was conducted to evaluate second-line, protease inhibitor (PI)-sparing therapy with ABC/efavirenz (EFV)/ddl plus HU or without HU in HIV-infected subjects failing to achieve HIV-1 RNA ≤ 400 copies/mL after ≥ 16 weeks of treatment with lamivudine /zidovudine or lamivudine/stavudine, plus 1 or 2 Pls. Subjects were assigned to ABC (300 mg twice daily)/ EFV (600 mg once daily)/ ddI (400 mg once daily) plus HU (500 mg twice daily) (n = 30) or this regimen without HU (n = 24). Results: Baseline mean HIV-1 RNA was 3.86 log10 copies/mL and CD4+ cell count was 345 cells/mm3. A similar percentage of subjects in the non-HU arm (58%) and HU arm (53%) completed the study. Intent-to-treat: missing = failure analysis showed no differences in proportions of subjects in the non-HU and HU arms achieving undetectable plasma HIV-1 RNA levels at week 24 (<400 copies/mL: 58% [14/24] vs 57% [17/30], P = 0.899; <50 copies/mL (50% [12/24] vs 47% [14/30], P = 0.780). Median change from baseline in CD4+ cell count in the non-HU and HU arms at week 48 was +114 cells/mm3 and -63 cells/mm3 (P = 0.007), respectively. Both regimens were generally well tolerated, although more subjects in the HU arm withdrew prematurely from the study due to adverse events (23% vs 4%). Four cases of possible ABC-related hypersensitivity were observed. Conclusion: ABC/EFV/ddI was an effective and well-tolerated second-line regimen for nucleoside/PI-experienced HIV-infected subjects. The addition of HU blunted the CD4+ cell response, did not appear to enhance antiviral activity, and resulted in more treatment-limiting adverse events
Incised valley paleoenvironments interpreted by seismic stratigraphic approach in Patos Lagoon, Southern Brazil
<div><p>ABSTRACT: The Rio Grande do Sul (RS) coastal plain area (33,000 km 2 ) had its physiography modified several times through the Quaternary, responding to allogenic and autogenic forcings. The Patos Lagoon covers a significant area of RS coastal plain (10,000 km 2 ), where incised valleys were identified in previous works. About 1,000 km of high resolution (3.5 kHz) seismic profiles, radiocarbon datings, Standard Penetration Test (SPT) and gravity cores were analyzed to interpret the paleoenvironmental evolution as preserved in incised valley infills. Seismic facies were recognized by seismic parameters. The sediment cores were used to ground-truth the seismic interpretations and help in the paleoenvironmental identification. Key surfaces were established to detail the stratigraphical framework, and seismic facies were grouped into four seismic units, which one classified in respective system tracts within three depositional sequences. The oldest preserved deposits are predominantly fluvial and estuarine facies, representing the falling stage and lowstand system tracts. The Holocene transgressive records are dominated by muddy material, mainly represented by estuarine facies with local variations. The transgression culminated in Late Holocene deposits of Patos Lagoon, representing the highstand system tract. The depositional pattern of the vertical succession was controlled by eustatic variations, while the autogenic forcing (paleogeography and sediment supply) modulated the local facies variation.</p></div
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