Radioactive sources of the monoenergetic low-energy conversion electrons from the decay of isomeric
83
m
Kr
are frequently used in the systematic measurements, particularly in the neutrino mass and ...dark matter experiments. For this purpose, the isomer is obtained by the decay of its parent radionuclide
83
Rb
. In order to get more precise data on the gamma-rays occuring in the
83
Rb
/
83
m
Kr
chain, we re-measured the relevant gamma-ray spectra, because the previous measurement took place in 1976. The obtained intensities are in fair agreement with the previous measurement. We have, however, improved the uncertainties by a factor of 4.3, identified a new gamma transition and determined more precisely energies of weaker gamma transitions.
Aim
Neurofibromatosis type 1 (NF1) is a genetic disorder with a cognitive profile that includes visual–spatial perception deficits and a high incidence of reading disability. There is a paucity of ...information about how this cognitively complex population responds to mainstream reading interventions. The clinical trial goals were to determine whether children and adolescents with NF1 and reading deficits (NF+RD) benefit from mainstream remedial reading programs and whether responsiveness varies with differences in program‐related visual–spatial demands.
Method
Forty‐nine participants (28 males, 21 females; aged 8–14y) with either NF+RD (n=17, 11 males, six females) or idiopathic reading deficit (IRD) (n=32, 17 males, 15 females) were randomly assigned to intensive remedial teaching using one of two multisensory reading programs: one with greater kinesthetic demands and the other with greater visual–spatial demands. Two control groups – wait‐list IRD (n=14, 11 males, three females) and typically developing readers (n=26, 13 males, 13 females) – received no treatment. Repeated measures and multivariate ANOVA analyses compared each group's growth in reading achievement from pre‐ to post‐testing.
Results
Treated groups showed significant growth whereas untreated groups did not. Comparing treated groups, the IRD group responded equally well to both interventions, whereas the NF+RD group showed a better response to the more kinesthetic approach.
Interpretation
Results suggest that multisensory remedial reading teaching that emphasizes kinesthetic demands more than visual–spatial demands is suitable for students with NF+RD.
What this paper adds
Children with neurofibromatosis type 1 and reading deficits benefit from mainstream approaches to remedial reading instruction.
They may benefit more from multisensory instruction that does not emphasize visual–spatial discrimination.
A relevant short‐term learning task for testing efficacy of drug treatments for cognitive deficits in neurofibramotosis type 1.
This article is commented on by Acosta on pages 1088–1089 of this issue.
Radioactive sources of the monoenergetic low-energy conversion electrons from
the decay of isomeric $^{83m}Kr$ are frequently used in the systematic
measurements, particularly in the neutrino mass ...and dark matter experiments.
For this purpose, the isomer is obtained by the decay of its parent
radionuclide $^{83}Rb$. In order to get more precise data on the gamma-rays
occuring in the $^{83}Rb$/$^{83m}Kr$ chain, we re-measured the relevant
gamma-ray spectra, because the previous measurement took place in 1976. The
obtained intensities are in fair agreement with this previous measurement. We
have, however, improved the uncertainties by a factor of 4.3, identified a new
gamma transition and determined more precisely energies of weaker gamma
transitions.
Radioactive sources of the monoenergetic low-energy conversion electrons from the decay of isomeric \(^{83m}Kr\) are frequently used in the systematic measurements, particularly in the neutrino mass ...and dark matter experiments. For this purpose, the isomer is obtained by the decay of its parent radionuclide \(^{83}Rb\). In order to get more precise data on the gamma-rays occuring in the \(^{83}Rb\)/\(^{83m}Kr\) chain, we re-measured the relevant gamma-ray spectra, because the previous measurement took place in 1976. The obtained intensities are in fair agreement with this previous measurement. We have, however, improved the uncertainties by a factor of 4.3, identified a new gamma transition and determined more precisely energies of weaker gamma transitions.
The fact that neutrinos carry a non-vanishing rest mass is evidence of physics beyond the Standard Model of elementary particles. Their absolute mass bears important relevance from particle physics ...to cosmology. In this work, we report on the search for the effective electron antineutrino mass with the KATRIN experiment. KATRIN performs precision spectroscopy of the tritium \(\beta\)-decay close to the kinematic endpoint. Based on the first five neutrino-mass measurement campaigns, we derive a best-fit value of \(m_\nu^{2} = {-0.14^{+0.13}_{-0.15}}~\mathrm{eV^2}\), resulting in an upper limit of \(m_\nu < {0.45}~\mathrm{eV}\) at 90 % confidence level. With six times the statistics of previous data sets, amounting to 36 million electrons collected in 259 measurement days, a substantial reduction of the background level and improved systematic uncertainties, this result tightens KATRIN's previous bound by a factor of almost two.
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