8,887 research outputs found
Recommended from our members
The effect of visual impairment on quality of life of children aged 3-16 years
Background: It is well known that visual impairment (VI) has a detrimental effect on Quality of Life (QoL) in adults.
Little is known about the effects of VI in childhood.
Aims: To evaluate the effects of VI on QoL of children. To the authorsâ knowledge, this is the first study containing
a comparison arm for children with VI.
Methods: QoL in children with VI (nŒ24, age 10.1362.89, 18 male, 6 female) was compared with an age-matched comparison group (nŒ24, age 9.8362.81, 18 male, 6 female) using the Low Vision Quality of Life Questionnaire. Factors (distance and near visual acuity and age) that could be used as predictors of QoL were assessed. These were measured with standard clinical tests.
Results: Children with VI had significantly lower QoL scores than the comparison group (p<0.001), resulting in a 35.6% reduction in total QoL score. QoL scores in children with VI were correlated with distance and near visual acuity (p<0.05). 38% of the variance could be predicted by these factors and age.
Conclusions: Consideration of the effects of this reduced QoL must be made. Further studies are needed to establish the benefit to QoL of different habilitation strategies
Frequency and time profiles of metric wave isolated Type I solar noise storm bursts at high spectral and temporal resolution
Type I noise storms constitute a sizeable faction of the active-Sun radio
emission component. Observations of isolated instances of such bursts, in the
swept-frequency-mode at metric wavelengths, have remained sparse, with several
unfilled regions in the frequency coverage. Dynamic spectra of the burst
radiation, in the 30 - 130 MHz band, obtained from the recently commissioned
digital High Resolution Spectrograph (HRS) at the Gauribidanur Radio
Observatory, on account of the superior frequency and time resolution, have
unravelled in explicit detail the temporal and spectral profiles of isolated
bursts. Apart from presenting details on their fundamental emission features,
the time and frequency profile symmetry, with reference to custom-specific
Gaussian distributions, has been chosen as the nodal criterion to statistically
explain the state of the source regions in the vicinity of magnetic
reconnections, the latent excitation agent that contributes to plasma wave
energetics, and the quenching phenomenon that causes damping of the burst
emission.Comment: 9 pages 7 black and white / grey-scale figures (inclusive of 3
composite). MNRAS - accepte
Nucleophilicity/Electrophilicity Excess in Analyzing Molecular Electronics
Intramolecular electron transfer capability of all metal aromatic and
anti-aromatic aluminum cluster compounds is studied in terms of density
functional theory based global and local reactivity descriptors. This study
will provide important inputs towards the fabrication of the material required
for molecular electronics.Comment: 21 pages, 6 figures, 13 table
The structure of dark matter halos in hierarchical clustering theories
During hierarchical clustering, smaller masses generally collapse earlier
than larger masses and so are denser on the average. The core of a small mass
halo could be dense enough to resist disruption and survive undigested, when it
is incorporated into a bigger object. We explore the possibility that a nested
sequence of undigested cores in the center of the halo, which have survived the
hierarchical, inhomogeneous collapse to form larger and larger objects,
determines the halo structure in the inner regions. For a flat universe with
, scaling arguments then suggest that the core density
profile is, with . But
whether such behaviour obtains depends on detailed dynamics. We first examine
the dynamics using a fluid approach to the self-similar collapse solutions for
the dark matter phase space density, including the effect of velocity
dispersions. We highlight the importance of tangential velocity dispersions to
obtain density profiles shallower than in the core regions. If
tangential velocity dispersions in the core are constrained to be less than the
radial dispersion, a cuspy core density profile shallower than 1/r cannot
obtain, in self-similar collapse. We then briefly look at the profiles of the
outer halos in low density cosmological models where the total halo mass is
convergent. Finally, we analyze a suite of dark halo density and velocity
dispersion profiles obtained in cosmological N-body simulations of models with
n= 0, -1 and -2. We find that the core-density profiles of dark halos, show
considerable scatter in their properties, but nevertheless do appear to reflect
a memory of the initial power spectrum, with steeper initial spectra producing
flatter core profiles. (Abridged)Comment: 31 pages, 7 figures, submitted to Ap
Cosmological Magnetic Fields from Primordial Helical Seeds
Most early Universe scenarios predict negligible magnetic fields on
cosmological scales if they are unprocessed during subsequent expansion of the
Universe. We present a new numerical treatment of the evolution of primordial
fields and apply it to weakly helical seeds as they occur in certain early
Universe scenarios. We find that initial helicities not much larger than the
baryon to photon number can lead to fields of about 10^{-13} Gauss with
coherence scales slightly below a kilo-parsec today.Comment: 4 revtex pages, 2 postscript figures include
A NUMERICAL SOLUTION TO DIFFERENT TYPES OF ECONOMIC LOAD DISPATCH PROBLEMS
This paper presents a newly proposed Novel TANAN's Algorithm (NTA) for solving different types of Economic Load Dispatch (ELD) problems. The main objective of NTA is to minimize the total fuel cost of the generating units, subjected to limits on generator power output, power loss and valve point loading effect. The NTA is a simple numerical random search approach based on a parabolic TANAN function. This paper presents an application of NTA to ELD problems for different IEEE standard test systems. The proposed method is compared with various optimization techniques and the simulation results show that the proposed algorithm outperforms previous optimization methods
- âŠ