11,331 research outputs found
Increasing Public Perceptions of Stroke
Analysis of publicly available data for the selected county of Rutland Vermont was performed to understand the underlying health problems affecting the county. Although VT overall has better health status indicators, including better access to care, and lower rates of chronic diseases than the nation, pockets of the state have higher rates of chronic diseases including obesity, DM, and cerebrovascular accidents.
Increasing awareness of stroke risk factors and symptoms is a cost-effective method to reduced stroke burden and provide successful treatment.https://scholarworks.uvm.edu/fmclerk/1621/thumbnail.jp
Antiferromagnetic order in (Ga,Mn)N nanocrystals: A density functional theory study
We investigate the electronic and magnetic properties of (Ga,Mn)N
nanocrystals using the density functional theory. We study both wurtzite and
zinc-blende structures doped with one or two substitutional Mn impurities. For
a single Mn dopant placed close to surface, the behavior of the empty
Mn-induced state, hereafter referred to as "Mn hole", is different from bulk
(Ga,Mn)N. The energy level corresponding to this off-center Mn hole lies within
the nanocrystal gap near the conduction edge. For two Mn dopants, the most
stable magnetic configuration is antiferromagnetic, and this was unexpected
since (Ga,Mn)N bulk shows ferromagnetism in the ground state. The surprising
antiferromagnetic alignment of two Mn spins is ascribed also to the holes
linked to the Mn impurities located close to surface. Unlike Mn holes in
(Ga,Mn)N bulk, these Mn holes in confined (Ga,Mn)N nanostructures do not
contribute to the ferromagnetic alignment of the two Mn spins
Fractal analysis of the galaxy distribution in the redshift range 0.45 < z < 5.0
Evidence is presented that the galaxy distribution can be described as a
fractal system in the redshift range of the FDF galaxy survey. The fractal
dimension was derived using the FDF galaxy volume number densities in the
spatially homogeneous standard cosmological model with ,
and H_0=70 \; \mbox{km} \; {\mbox{s}}^{-1} \;
{\mbox{Mpc}}^{-1}. The ratio between the differential and integral number
densities and obtained from the red and blue FDF
galaxies provides a direct method to estimate , implying that and
vary as power-laws with the cosmological distances. The
luminosity distance , galaxy area distance
and redshift distance were plotted against
their respective number densities to calculate by linear fitting. It was
found that the FDF galaxy distribution is characterized by two single fractal
dimensions at successive distance ranges. Two straight lines were fitted to the
data, whose slopes change at or depending on
the chosen cosmological distance. The average fractal dimension calculated
using changes from to for all galaxies, and decreases as
increases. Small values of at high mean that in the past galaxies were
distributed much more sparsely and the large-scale galaxy structure was then
possibly dominated by voids. Results of Iribarrem et al. (2014,
arXiv:1401.6572) indicating similar fractal features with in the far-infrared sources of the Herschel/PACS evolutionary
probe (PEP) at are also mentioned.Comment: LaTex, 15 pages, 28 figures, 4 tables. To appear in "Physica A
Optical spin control in nanocrystalline magnetic nanoswitches
We investigate the optical properties of (Cd,Mn)Te quantum dots (QDs) by
looking at the excitons as a function of the Mn impurities positions and their
magnetic alignments. When doped with two Mn impurities, the Mn spins, aligned
initially antiparallel in the ground state, have lower energy in the parallel
configuration for the optically active spin-up exciton. Hence, the
photoexcitation of the QD ground state with antiparallel Mn spins induces one
of them to flip and they align parallel. This suggests that (Cd,Mn)Te QDs are
suitable for spin-based operations handled by light
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