605 research outputs found
Inclusive quasi-elastic electron-nucleus scattering
This article presents a review of the field of inclusive quasi-elastic
electron-nucleus scattering. It discusses the approach used to measure the data
and includes a compilation of data available in numerical form. The theoretical
approaches used to interpret the data are presented. A number of results
obtained from the comparison between experiment and calculation are then
reviewed. The analogies and differences to other fields of physics exploiting
quasi-elastic scattering from composite systems are pointed out.Comment: Accepted for publication in Reviews of Modern Physic
Sensitivities of the Proton-Nucleus Elastical Scattering Observables of 6He and 8He at Intermediate Energies
We investigate the use of proton-nucleus elastic scattering experiments using
secondary beams of 6He and 8He to determine the physical structure of these
nuclei. The sensitivity of these experiments to nuclear structure is examined
by using four different nuclear structure models with different spatial
features using a full-folding optical potential model. The results show that
elastic scattering at intermediate energies (<100 MeV per nucleon) is not a
good constraint to be used to determine features of structure. Therefore
researchers should look elsewhere to put constraints on the ground state wave
function of the 6He and 8He nuclei.Comment: To be published in Phys. Rev.
Application of Multiple Scattering Theory to Lower Energy Elastic Nucleon-Nucleus Reactions
The optical model potentials for nucleon-nucleus elastic scattering at
~MeV are calculated for C, O, Si, Ca,
Fe, Zr and Pb in first order multiple scattering theory,
following the prescription of the spectator expansion, where the only inputs
are the free NN potentials, the nuclear densities and the nuclear mean field as
derived from microscopic nuclear structure calculations. These potentials are
used to predict differential cross sections, analyzing powers and spin rotation
functions for neutron and proton scattering at 65 MeV projectile energy and
compared with available experimental data.Comment: 12 pages (Revtex 3.0), 7 fig
Correlations in a Many-Body Calculation of Li
A many-body calculation of Li is presented where the only input is the
well-tested, finite-range {\it D1S} effective interaction of {\it Gogny}.
Pairing correlations are included in a constrained Hartree-Fock-Bogolyubov
calculation, while long-range collective correlations are introduced using a
GCM derived calculation. Correlations are found to play an important role in
describing Li. A substantive underlying Li core of Li is
found, which has a different density profile than a free Li nucleus. This
may have significant implications in the use of a three-body framework in
studies of Li.Comment: 23 pages typeset in revtex 2.0 with 8 postscript figures in
accompanying uuencoded fil
Epistemic and social scripts in computer-supported collaborative learning
Collaborative learning in computer-supported learning environments typically means that learners work on tasks together, discussing their individual perspectives via text-based media or videoconferencing, and consequently acquire knowledge. Collaborative learning, however, is often sub-optimal with respect to how learners work on the concepts that are supposed to be learned and how learners interact with each other. One possibility to improve collaborative learning environments is to conceptualize epistemic scripts, which specify how learners work on a given task, and social scripts, which structure how learners interact with each other. In this contribution, two studies will be reported that investigated the effects of epistemic and social scripts in a text-based computer-supported learning environment and in a videoconferencing learning environment in order to foster the individual acquisition of knowledge. In each study the factors ‘epistemic script’ and ‘social script’ have been independently varied in a 2×2-factorial design. 182 university students of Educational Science participated in these two studies. Results of both studies show that social scripts can be substantially beneficial with respect to the individual acquisition of knowledge, whereas epistemic scripts apparently do not to lead to the expected effects
A qualitative emancipatory inquiry into relationships between people with mental disorders and health professionals
Introduction: A therapeutic alliance with people is essential for the efficacy of treatments. However, the traditional paternalistic values of the Mediterranean society may be incompatible with patient autonomy. Aim: To explore the therapeutic relationship from the perspective of people diagnosed with mental disorders with health professionals, including nurses. Methods: This emancipatory research was performed through focus groups, with people with mental disorders who had a variety of diagnoses and experiences of acute and community‐based mental health services and other healthcare services. Data were analysed using the content analysis method. Results: Four main themes emerged: stereotypes and prejudice; quality of interactions and treatment; emotional and behavioural impacts; and demands. Discussion: According to the participants' descriptions, health professionals are not exempt from prejudice against persons with psychiatric diagnoses. They reported experiencing abuse of power, malpractice, and overmedication. Thus, in the Mediterranean culture, professional attitudes may represent a barrier for an appropriate therapeutic alliance, and people with mental disorders do not feel involved in making decisions about their health. Implications for practice: Knowing how people with mental disorders perceive their interactions with health professionals and the effects is necessary to move the care model towards more symmetric relationships that facilitate a therapeutic alliance
Unintended learning in primary school practical science lessons from Polanyi’s perspective of intellectual passion
This study explored, from the perspective of intellectual passion developed by
Michael Polanyi, the unintended learning that occurred in primary practical science lessons.
We use the term ‘unintended’ learning to distinguish it from ‘intended’ learning that
appears in teachers’ learning objectives. Data were collected using video and audio
recordings of a sample of twenty-four whole class practical science lessons, taught by five
teachers, in Korean primary schools with 10- to 12-year-old students. In addition, video
and audio recordings were made for each small group of students working together in order
to capture their activities and intra-group discourse. Pre-lesson interviews with the teachers
were undertaken and audio-recorded to ascertain their intended learning objectives.
Selected key vignettes, including unintended learning, were analysed from the perspective
of intellectual passion developed by Polanyi. What we found in this study is that unintended
learning could occur when students got interested in something in the first place and
could maintain their interest. In addition, students could get conceptual knowledge when
they tried to connect their experience to their related prior knowledge. It was also found
that the processes of intended learning and of unintended learning were different. Intended
learning was characterized by having been planned by the teacher who then sought to
generate students’ interest in it. In contrast, unintended learning originated from students’
spontaneous interest and curiosity as a result of unplanned opportunities. Whilst teachers’
persuasive passion comes first in the process of intended learning, students’ heuristic
passion comes first in the process of unintended learning. Based on these findings, we argue that teachers need to be more aware that unintended learning, on the part of individual
students, can occur during their lesson and to be able to better use this opportunity
so that this unintended learning can be shared by the whole class. Furthermore, we argue
that teachers’ deliberate action and a more interactive classroom culture are necessary in
order to allow students to develop, in addition to heuristic passion, persuasive passion
towards their unintended learning
IgE sensitisation in relation to flow-independent nitric oxide exchange parameters
BACKGROUND: A positive association between IgE sensitisation and exhaled NO levels has been found in several studies, but there are no reports on the compartment of the lung that is responsible for the increase in exhaled NO levels seen in IgE-sensitised subjects. METHODS: The present study comprised 288 adult subjects from the European Community Respiratory Health Survey II who were investigated in terms of lung function, IgE sensitisation (sum of specific IgE), smoking history and presence of rhinitis and asthma. Mean airway tissue concentration of NO (Caw(NO)), airway transfer factor for NO (Daw(NO)), mean alveolar concentration of NO (Calv(NO)) and fractional exhaled concentration of NO at a flow rate of 50 mL s(-1 )(FE(NO 0.05)) were determined using the extended NO analysis. RESULTS: IgE-sensitised subjects had higher levels (geometric mean) of FE(NO 0.05 )(24.9 vs. 17.3 ppb) (p < 0.001), Daw(NO )(10.5 vs. 8 mL s(-1)) (p = 0.02) and Caw(NO )(124 vs. 107 ppb) (p < 0.001) and positive correlations were found between the sum of specific IgE and FE(NO 0.05), Caw(NO )and Daw(NO )levels (p < 0.001 for all correlations). Sensitisation to cat allergen was the major determinant of exhaled NO when adjusting for type of sensitisation. Rhinitis and asthma were not associated with the increase in exhaled NO variables after adjusting for the degree of IgE sensitisation. CONCLUSION: The presence of IgE sensitisation and the degree of allergic sensitisation were related to the increase in airway NO transfer factor and the increase in NO concentration in the airway wall. Sensitisation to cat allergen was related to the highest increases in exhaled NO parameters. Our data suggest that exhaled NO is more a specific marker of allergic inflammation than a marker of asthma or rhinitis
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