Ferromagnetic effect and spin assignment for the 390 keV state in 62Cu

The 390 keV isomeric state of 62Cu is assigned as Jπ = 4+. The magnetic hyperfine interaction has been observed in the 60Ni(α, pnγ) 62Cu reaction and the deduced Larmor period is consistent with known values of g and the hyperfine field of Cu in Ni

Characteristics of the injected ion beam in the ECR charge breeder 1+→n+1^{+}\to n^{+}

Different ion species (rare gases, alkali, metallic) have been injected on the axis of the MINIMAFIOS - 10 GHz - Electron Cyclotron Resonance Ion Source which is the basics of the 1+ -> n+ method, special attention have been paid to the optics of the incoming beam for the validation of the 1+ -> n+ method for the SPIRAL project (Radioactive Ion Beam facility). The capture of the incoming ion beam by the ECR plasma depends, first, on the relative energy of the incoming ions with respect to the average ion energy in the plasma, and secondly, on the optics of the injection line. The efficiency of the process when varying the potential V n+ of the MINIMAFIOS source with respect to the potential V 1+ applied to the 1+ source (DV=V n+ -V 1+ ) is an image of the energy dispersion of the 1+ beam. 1+ -> n+ spectra efficiencies, DV efficiency dependence for the most efficient charge state obtained, and measured primary beam emittances are given for the Ar, Rb, Pb, Cr. Highest efficiencies obtained are respectively Ar1+ -> Ar8+ : 8.7 %, Rb1+ -> Rb15+ : 5.5 %, Pb 1+ -> Pb 22+ : 4.8 % , Cr 1+ -> Cr 12+ : 3.5 %. Last results obtained are given for Sulfur and Uranium

The role of short-term memory and visuo-spatial skills in numerical magnitude processing: evidence from Turner syndrome

Peer reviewe

Cognitive Reserve and the Prevention of Dementia: the Role of Physical and Cognitive Activities

Purpose of Review: The article discusses the two most significant modifiable risk factors for dementia, namely, physical inactivity and lack of stimulating cognitive activity, and their effects on developing cognitive reserve. Recent Findings: Both of these leisure-time activities were associated with significant reductions in the risk of dementia in longitudinal studies. In addition, physical activity, particularly aerobic exercise, is associated with less age-related gray and white matter loss and with less neurotoxic factors. On the other hand, cognitive training studies suggest that training for executive functions (e.g., working memory) improves prefrontal network efficiency, which provides support to brain functioning in the face of cognitive decline. Summary: While physical activity preserves neuronal structural integrity and brain volume (hardware), cognitive activity strengthens the functioning and plasticity of neural circuits (software), thus supporting cognitive reserve in different ways. Future research should examine whether lifestyle interventions incorporating these two domains can reduce incident dementia

Cognitive reserve and Alzheimer's disease biomarkers are independent determinants of cognition

The objective of this study was to investigate how a measure of educational and occupational attainment, a component of cognitive reserve, modifies the relationship between biomarkers of pathology and cognition in Alzheimer's disease. The biomarkers evaluated quantified neurodegeneration via atrophy on magnetic resonance images, neuronal injury via cerebral spinal fluid t-tau, brain amyloid-β load via cerebral spinal fluid amyloid-β1–42 and vascular disease via white matter hyperintensities on T2/proton density magnetic resonance images. We included 109 cognitively normal subjects, 192 amnestic patients with mild cognitive impairment and 98 patients with Alzheimer's disease, from the Alzheimer's Disease Neuroimaging Initiative study, who had undergone baseline lumbar puncture and magnetic resonance imaging. We combined patients with mild cognitive impairment and Alzheimer's disease in a group labelled ‘cognitively impaired’ subjects. Structural Abnormality Index scores, which reflect the degree of Alzheimer's disease-like anatomic features on magnetic resonance images, were computed for each subject. We assessed Alzheimer's Disease Assessment Scale (cognitive behaviour section) and mini-mental state examination scores as measures of general cognition and Auditory–Verbal Learning Test delayed recall, Boston naming and Trails B scores as measures of specific domains in both groups of subjects. The number of errors on the American National Adult Reading Test was used as a measure of environmental enrichment provided by educational and occupational attainment, a component of cognitive reserve. We found that in cognitively normal subjects, none of the biomarkers correlated with the measures of cognition, whereas American National Adult Reading Test scores were significantly correlated with Boston naming and mini-mental state examination results. In cognitively impaired subjects, the American National Adult Reading Test and all biomarkers of neuronal pathology and amyloid load were independently correlated with all cognitive measures. Exceptions to this general conclusion were absence of correlation between cerebral spinal fluid amyloid-β1–42 and Boston naming and Trails B. In contrast, white matter hyperintensities were only correlated with Boston naming and Trails B results in the cognitively impaired. When all subjects were included in a flexible ordinal regression model that allowed for non-linear effects and interactions, we found that the American National Adult Reading Test had an independent additive association such that better performance was associated with better cognitive performance across the biomarker distribution. Our main conclusions included: (i) that in cognitively normal subjects, the variability in cognitive performance is explained partly by the American National Adult Reading Test and not by biomarkers of Alzheimer's disease pathology; (ii) in cognitively impaired subjects, the American National Adult Reading Test, biomarkers of neuronal pathology (structural magnetic resonance imaging and cerebral spinal fluid t-tau) and amyloid load (cerebral spinal fluid amyloid-β1–42) all independently explain variability in general cognitive performance; and (iii) that the association between cognition and the American National Adult Reading Test was found to be additive rather than to interact with biomarkers of Alzheimer's disease pathology

Étude d'un ioniseur à haut rendement pour faisceaux atomiques

Pour produire des neutrons polarisés par réaction T(d, n)α, à partir de deutons polarisés, un ioniseur à haut rendement a été réalisé. La source de deutérium atomique, placée au potentiel zéro, donne un faisceau de 4 x 1015 atomes polarisés par seconde, sur une surface de 2,5 cm 2 à l'entrée d'un ioniseur placé à la haute tension (150 kV). Le rendement d'ionisation en D+ mesuré est au moins égal à 10-3, mais avec une émittance du faisceau d'ions encore importante (≤ 800 mm x mr à 4 keV)

Étude d'un ioniseur à haut rendement pour faisceaux atomiques

To produce polarized neutrons by the T(d, n)α reaction, from polarized deuterons, an ionizer with high efficiency has been built. A beam of 4 x 1015 polarized atoms, on 2.5 cm2 is given by an atomic deuterium source at ground potential. The ionizer works at 150 kV, and the measurement of the ionization efficiency in D+ is at least 10 -3. The ion beam emittance measured at 4 keV is less than 800 mm x mr.Pour produire des neutrons polarisés par réaction T(d, n)α, à partir de deutons polarisés, un ioniseur à haut rendement a été réalisé. La source de deutérium atomique, placée au potentiel zéro, donne un faisceau de 4 x 1015 atomes polarisés par seconde, sur une surface de 2,5 cm 2 à l'entrée d'un ioniseur placé à la haute tension (150 kV). Le rendement d'ionisation en D+ mesuré est au moins égal à 10-3, mais avec une émittance du faisceau d'ions encore importante (≤ 800 mm x mr à 4 keV)

Secondary radiations in cone-beam computed tomography: simulation study

International audienceAccurate quantitative reconstruction in kV cone-beam computed tomography (CBCT) is challenged by the presence of secondary radiations (scattering, fluorescence, and bremsstrahlung photons) coming from the object and from the detector itself. The authors present a simulation study of the CBCT imaging chain and its integration into a comprehensive correction algorithm. A layer model of the flat-panel detector is built in a Monte Carlo environment in order to help in localizing and analyzing the secondary radiations. The contribution of these events to the final image is estimated with a convolution model to account for detector secondary radiations combined with a forced-detection scheme to speed-up the Monte Carlo simulation without loss of accuracy. We more specifically assess to what extent a 2D description of the flat-panel detector would be sufficient for the forward model (i.e., the image formation process) of an iterative correction algorithm, both in terms of energy and incidence angle of incoming photons. Results show that both object and detector secondary radiations have to be considered in CBCT. The correction algorithm iteratively compensates for the secondary radiations and the beam hardening in object space. Preliminary results on tomographic acquisitions demonstrate a quantitative improvement on the first iteratio