321 research outputs found
Seagull and pion-in-flight currents in neutrino-induced and knockout
[Background] The neutrino-nucleus () cross section is a major source
of systematic uncertainty in neutrino-oscillation studies. A precise
scattering model, in which multinucleon effects are incorporated, is pivotal
for an accurate interpretation of the data. [Purpose] In interactions,
meson-exchange currents (MECs) can induce two-nucleon () knockout from the
target nucleus, resulting in a two-particle two-hole (2p2h) final state. They
also affect single nucleon () knockout reactions, yielding a one-particle
one-hole (1p1h) final state. Both channels affect the inclusive strength. We
present a study of axial and vector, seagull and pion-in-flight currents in
muon-neutrino induced and knockout reactions on C. [Method]
Bound and emitted nucleons are described as Hartree-Fock wave functions. For
the vector MECs, the standard expressions are used. For the axial current,
three parameterizations are considered. The framework developed here allows for
a treatment of MECs and short-range correlations (SRCs). [Results] Results are
compared with electron-scattering data and with literature. The strengths of
the seagull, pion-in-flight and axial currents are studied separately and
double differential cross sections including MECs are compared with results
including SRCs. A comparison with MiniBooNE and T2K data is presented.
[Conclusions] In the 1p1h channel, the effects of the MECs tend to cancel each
other, resulting in a small effect on the double differential cross section.
knockout processes provide a small contribution to the inclusive double
differential cross section, ranging from the knockout threshold into the
dip region. A fair agreement with the MiniBooNE and T2K data is reached.Comment: 16 pages, 10 figure
ABC-training as a new intervention for hazardous alcohol drinking: Two proof-of-principle randomized pilot studies
Background and Aims: ABC-training is a new intervention to encourage health behavior change that targets the automatic activation of adaptive beliefs (i.e. automatic inferences). The aim of this proof-of-principle study was to test the effectiveness of web-based ABC-training to change outcome expectancies of alcohol drinking in a sample of hazardous drinkers. Design: One exploratory and one confirmatory experiment with two between-subject conditions (online ABC- and control-training) and assessments at baseline and 1 week later (after three sessions of training). Setting: Participants recruited on Prolific Academic completed the web-based study. Participants: Adults with self-reported hazardous alcohol drinking (Experiment 1: 193 adults, United Kingdom, age mean = 46.7 years; Experiment 2: 282 adults, different nationalities, age mean = 38.3 years). Intervention and Comparator: ABC-training involved completing an online task that required choosing personally relevant alternative behaviors to drinking alcohol in personally relevant antecedent contexts to attain personally important outcomes. Comparator was control-training, in which participants selected both the alternative behaviors and alcohol drinking an equal number of times. Training was completed at baseline, after 3 days and after 1 week. Measurements: Primary outcome was change in automatic and self-reported (negative/positive) outcome expectancies of alcohol drinking from baseline to after 1 week. Secondary outcomes were change in weekly alcohol consumption, self-efficacy, craving and motivation (and approach-alcohol associations in Experiment 1). Moderators were baseline outcome scores, motivation, age and alcohol dependency. Findings: Findings of this study are as follows: stronger increase in negative outcome expectancies after ABC- than control-training (Experiment 1: self-report, 95% confidence interval of difference scores (CIdiff) = [0.04, Inf]; automatic, CIdiff = [0.01, Inf]; Experiment 2: self-report, CIdiff = [0.16, Inf]; automatic, CIdiff = [0.002, Inf]). Stronger reduction in self-reported positive outcome expectancies after ABC- than control-training (Experiment 1: CIdiff = [−Inf, −0.01]; Experiment 2: CIdiff = [−Inf, −0.21]) but mixed findings on automatic positive outcome expectancies (Experiment 1: CIdiff = [−Inf, 0.02]; Experiment 2: CIdiff = [−Inf, −0.001]). Conclusions: ABC-training may change outcome expectancies of alcohol consumption, but testing of clinically relevant effects in other samples is warranted.</p
Impact of low-energy nuclear excitations on neutrino-nucleus scattering at MiniBooNE and T2K kinematics
[Background] Meticulous modeling of neutrino-nucleus interactions is
essential to achieve the unprecedented precision goals of present and future
accelerator-based neutrino-oscillation experiments. [Purpose] Confront our
calculations of charged-current quasielastic cross section with the
measurements of MiniBooNE and T2K, and to quantitatively investigate the role
of nuclear-structure effects, in particular, low-energy nuclear excitations in
forward muon scattering. [Method] The model takes the mean-field (MF) approach
as the starting point, and solves Hartree-Fock (HF) equations using a Skyrme
(SkE2) nucleon-nucleon interaction. Long-range nuclear correlations are taken
into account by means of the continuum random-phase approximation (CRPA)
framework. [Results] We present our calculations on flux-folded double
differential, and flux-unfolded total cross sections off C and compare
them with MiniBooNE and (off-axis) T2K measurements. We discuss the importance
of low-energy nuclear excitations for the forward bins. [Conclusions] The CRPA
predictions describe the gross features of the measured cross sections. They
underpredict the data (more in the neutrino than in the antineutrino case)
because of the absence of processes beyond pure quasielastic scattering in our
model. At very forward muon scattering, low-energy nuclear excitations ( 50 MeV) account for nearly 50% of the flux-folded cross section.Comment: 8 pages, 9 figures. Version published in Physical Review
What do implicit measures measure?
We identify several ongoing debates related to implicit measures, surveying prominent views and considerations in each debate. First, we summarize the debate regarding whether performance on implicit measures is explained by conscious or unconscious representations. Second, we discuss the cognitive structure of the operative constructs: are they associatively or propositionally structured? Third, we review debates whether performance on implicit measures reflects traits or states. Fourth, we discuss the question of whether a person’s performance on an implicit measure reflects characteristics of the person who is taking the test or characteristics of the situation in which the person is taking the test. Finally, we survey the debate about the relationship between implicit measures and (other kinds of) behavior
Acute infectieuze (niet Clostridium difficile geassocieerde) diarree bij ouderen
Acute –niet antibiotica geassocieerde- diarree is een frequente aandoening die bij ouderen ernstig kan verlopen omwille van de grotere fragiliteit van deze bevolkingsgroep. Acute diarree is meestal van infectieuze oorsprong, en meest frequent te wijten aan een virale infectie. De belangrijkste therapeutische maatregel is het voorzien van voldoende rehydratie. Bij ernstige diarree van bacterie¨ le oorsprong is een antibiotische behandeling aangewezen
Immobilisation versus immediate mobilisation after intrauterine insemination: randomised controlled trial
Objective To evaluate the effectiveness of 15 minutes of immobilisation versus immediate mobilisation after intrauterine insemination
The formation and evolution of binary systems. III. Low-mass binaries in the Praesepe cluster
With the aim of investigating the binary population of the 700 Myr old
Praesepe cluster, we have observed 149 G and K-type cluster members using
adaptive optics. We detected 26 binary systems with an angular separation
ranging from less than 0.08 to 3.3 arcsec (15-600 AU). After correcting for
detection biases, we derive a binary frequency (BF) in the logP (days) range
from 4.4 to 6.9 of 25.3 +/- 5.4%, which is similar to that of field G-type
dwarfs (23.8%, Duquennoy & Mayor 1991). This result, complemented by similar
ones obtained for the 2 Myr old star forming cluster IC 348 (Paper II) and the
120 Myr old Pleiades open cluster (Paper I), indicates that the fraction of
long-period binaries does not significantly evolve over the lifetime of
galactic open clusters. We compare the distribution of cluster binaries to the
binary populations of star forming regions, most notably Orion and Taurus, to
critically review current ideas regarding the binary formation process. We
conclude that it is still unclear whether the lower binary fraction observed in
young clusters compared to T associations is purely the result of the early
dynamical disruption of primordial binaries in dense clusters or whether it
reflects intrinsically different modes of star formation in clusters and
associations. We also note that if Taurus binaries result from the dynamical
decay of small-N protostellar aggregates, one would predict the existence of a
yet to be found dispersed population of mostly single substellar objects in the
Taurus cloud.Comment: 10 pages, 3 figure
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