21 research outputs found
Dimensionality dependent electronic structure of the exfoliated van der Waals antiferromagnet NiPS
Resonant Inelastic X-ray Scattering (RIXS) was used to measure the local
electronic structure in few-layer exfoliated flakes of the van der Waals
antiferromagnet NiPS. The resulting spectra show a systematic softening and
broadening of multiplet excitations with decreasing layer count from
the bulk to three atomic layers (3L). These trends are driven by a decrease in
the transition metal-ligand and ligand-ligand hopping integrals, and in the
charge-transfer energy: = 0.60 eV in the bulk and 0.22 eV in 3L
NiPS. Relevant intralayer magnetic exchange integrals computed from the
electronic parameters exhibit a systematic decrease in the average interaction
strength with thickness and place 2D NiPS close to the phase boundary
between stripy and spiral antiferromagnetic order, which may explain the
apparent vanishing of long-range order in the 2D limit. This study explicitly
demonstrates the influence of layer electronic interactions on
layer ones in insulating magnets. As a consequence, the magnetic
Hamiltonian in few-layer insulating magnets can be significantly different from
that in the bulk.Comment: 5 pages, 4 figures; additional 9 pages and 13 figures of
supplementary informatio
Do inattention and hyperactivity symptoms equal scholastic impairment? evidence from three European cohorts
Background
Attention Deficit/Hyperactivity Disorder (ADHD) affects many children, adolescents, and adults and is associated with a number of impairments. Poor academic performance is related to ADHD in clinical samples. However, it is unclear to what extent core ADHD symptoms and scholastic impairment are related in non-referred school-aged children.
Methods
Data come from three population-based cohorts from Sweden, Denmark, and Finland, which are part of the Nordic Network on ADHD. The combined sample size was 13,087 children who were studied at ages 7–8 or 10–12 years. Teachers rated children on inattention and hyperactivity symptoms and reported children's scholastic performance on basic skills.
Results
There was a significant association in all cohorts between core ADHD symptoms and scholastic impairment in reading, writing, and mathematics. Particularly, inattention was related to a two to tenfold increase in scholastic impairment. Prevalence of hyperactivity symptoms was similar across the three cohorts, but inattention was lowest among children from the Finnish cohort, after stratification on living conditions.
Conclusion
These results extend previous reports of scholastic impairment among children with clinically diagnosed ADHD to non-referred population samples from three European countries. Surveillance policies should be implemented in school systems to catch children in need of behavioral or scholastic support early
DBcat: a catalog of biological databases.
The DBcat (http://www.infobiogen.fr/services/dbcat) is a comprehensive catalog of biological databases, maintained and curated on a daily basis at GIS Infobiogen. It contains more than 400 databases classified by application domains. The DBcat is a structured flat file library, that can be searched by means of an SRS server or a dedicated Web interface. The files are available for downloading from Infobiogen anonymous ftp server