139 research outputs found
Vaccine Hesitancy in the United States and Switzerland
Get PDFVaccine hesitancy (VH), or the reluctance or refusal to participate in vaccination programs, is a complex phenomenon with far-reaching impacts on society. VH can impact vaccine uptake and facilitate subsequent outbreaks, as seen with the case of measles. Perceptions of vaccination are similar in the United States and Switzerland, and misinformation in each country contributed to VH through impaired parental risk-benefit analysis; parental analysis and subsequent VH is associated with both anti-vaccination messages gaining prominence and a decrease in the public perception of the health risk from vaccine-preventable diseases (VPDs). There are many proposed strategies for addressing VH on both clinical and public health levels, most of which center around communication. So far, no single strategy has been shown to be most effective. The literature and the interviews included multiple possible strategies to be tested in the future
Surface Emissions Modulate Indoor SVOC Concentrations through Volatility-Dependent Partitioning.
Get PDFMeasurements by semivolatile thermal desorption aerosol gas chromatography (SV-TAG) were used to investigate how semivolatile organic compounds (SVOCs) partition among indoor reservoirs in (1) a manufactured test house under controlled conditions (HOMEChem campaign) and (2) a single-family residence when vacant (H2 campaign). Data for phthalate diesters and siloxanes suggest that volatility-dependent partitioning processes modulate airborne SVOC concentrations through interactions with surface-laden condensed-phase reservoirs. Airborne concentrations of SVOCs with vapor pressures in the range of C13 to C23 alkanes were observed to be correlated with indoor air temperature. Observed temperature dependencies were quantitatively similar to theoretical predictions that assumed a surface-air boundary layer with equilibrium partitioning maintained at the air-surface interface. Airborne concentrations of SVOCs with vapor pressures corresponding to C25 to C31 alkanes correlated with airborne particle mass concentration. For SVOCs with higher vapor pressures, which are expected to be predominantly gaseous, correlations with particle mass concentration were weak or nonexistent. During primary particle emission events, enhanced gas-phase emissions from condensed-phase reservoirs partitioned to airborne particles, contributing substantially to organic particulate matter. An emission event related to oven-usage was inferred to deposit siloxanes in condensed-phase reservoirs throughout the house, leading to the possibility of reemission during subsequent periods with high particle loading
Is the structure of 42Si understood?
Get PDFA more detailed test of the implementation of nuclear forces that drive shell
evolution in the pivotal nucleus \nuc{42}{Si} -- going beyond earlier
comparisons of excited-state energies -- is important. The two leading
shell-model effective interactions, SDPF-MU and SDPF-U-Si, both of which
reproduce the low-lying \nuc{42}{Si}() energy, but whose predictions for
other observables differ significantly, are interrogated by the population of
states in neutron-rich \nuc{42}{Si} with a one-proton removal reaction from
\nuc{43}{P} projectiles at 81~MeV/nucleon. The measured cross sections to the
individual \nuc{42}{Si} final states are compared to calculations that combine
eikonal reaction dynamics with these shell-model nuclear structure overlaps.
The differences in the two shell-model descriptions are examined and linked to
predicted low-lying excited states and shape coexistence. Based on the
present data, which are in better agreement with the SDPF-MU calculations, the
state observed at 2150(13)~keV in \nuc{42}{Si} is proposed to be the ()
level.Comment: accepted in Physical Review Letter
Structure and Decay Correlations of Two-Neutron Systems Beyond the Dripline
Full text linkThe two-neutron unbound systems of 16Be, 13Li, 10He, and 26O have been measured using the Modular Neutron Array (MoNA) and 4 Tm Sweeper magnet setup. The correlations of the 3-body decay for the 16Be and 13Li were extracted and demonstrated a strong correlated enhancement between the two neutrons. The measurement of the 10He ground state resonance from a 14Be(−2p2n) reaction provided insight into previous predictions that wavefunction of the entrance channel, projectile, can influence the observed decay energy spectrum for the unbound system. Lastly, the decay-in-target (DiT) technique was utilized to extract the lifetime of the 26O ground state. The measured lifetime of 4.5+1.1 −1.5 (stat.)±3(sys.) ps provides the first indication of two-neutron radioactivity
First observation of Li ground state
Full text linkThe ground state of neutron-rich unbound Li was observed for the first
time in a one-proton removal reaction from Be at a beam energy of 53.6
MeV/u. The Li ground state was reconstructed from Li and two
neutrons giving a resonance energy of 120 keV. All events
involving single and double neutron interactions in the Modular Neutron Array
(MoNA) were analyzed, simulated, and fitted self-consistently. The three-body
(Li+) correlations within Jacobi coordinates showed strong
dineutron characteristics. The decay energy spectrum of the intermediate
Li system (Li+) was described with an s-wave scattering length
of greater than -4 fm, which is a smaller absolute value than reported in a
previous measurement.Comment: Accepted for publication in Phys. Rev. C as a Rapid Communicatio
Octupole strength in the neutron-rich calcium isotopes
Full text linkLow-lying excited states of the neutron-rich calcium isotopes Ca
have been studied via -ray spectroscopy following inverse-kinematics
proton scattering on a liquid hydrogen target using the GRETINA -ray
tracking array. The energies and strengths of the octupole states in these
isotopes are remarkably constant, indicating that these states are dominated by
proton excitations.Comment: 15 pages, 3 figure
Observation of Ground-State Two-Neutron Decay
Get PDFNeutron decay spectroscopy has become a successful tool to explore nuclear
properties of nuclei with the largest neutron-to-proton ratios. Resonances in
nuclei located beyond the neutron dripline are accessible by kinematic
reconstruction of the decay products. The development of two-neutron detection
capabilities of the Modular Neutron Array (MoNA) at NSCL has opened up the
possibility to search for unbound nuclei which decay by the emission of two
neutrons. Specifically this exotic decay mode was observed in 16Be and 26O.Comment: To be published in Acta Physica Polonica
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