1,669 research outputs found
Using coloured filters to reduce the symptoms of visual stress in children with reading delay
Background: Meares Irlen Syndrome (MIS), otherwise known as “visual stress”, is one condition that can cause difficulties with reading. Aim: This study aimed to compare the effect of two coloured-filter systems on the symptoms of visual stress in children with reading delay. Methods: The study design was a pre-test, post-test, randomized head-to-head comparison of two filter systems on the symptoms of visual stress in school children. A total of 68 UK mainstream schoolchildren with significant impairment in reading ability completed the study. Results: The filter systems appeared to have a large effect on the reported symptoms between pre and post three-month time points (d = 2.5, r = 0.78). Both filter types appeared to have large effects (Harris d = 1.79, r = 0.69 and DRT d = 3.22, r = 0.85). Importantly, 35% of participants’ reported that their symptoms had resolved completely; 72% of the 68 children appeared to gain improvements in three or more visual stress symptoms. Conclusion and significance: The reduction in symptoms, which appeared to be brought about by the use of coloured filters, eased the visual discomfort experienced by these children when reading. This type of intervention therefore has the potential to facilitate occupational engagement
Spin entropy as the likely source of enhanced thermopower in $\rm\bf Na_xCo_2O_4
In an electric field, the flow of electrons in a solid produces an entropy
current in addition to the familiar charge current. This Peltier effect
underlies all thermoelectric refrigerators. The upsurge in thermoelectric
cooling applications has led to a search for more efficient Peltier materials
and to renewed theoretical interest in how electron-electron interaction may
enhance the thermopower of materials such as the transition-metal oxides
\cite{Mahan,Beni,Kotliar,Chaikin}. An important factor in this enhancement is
the electronic spin entropy, which is predicted \cite{Chaikin,Kwak,KwakChaikin}
to dominate the entropy current. Here we report evidence for such suppression
in the layered oxide , and present evidence that it is a
strong-correlation effect.Comment: 5 pages, 5 figures, already publishe
Accretion Disks Around Black Holes: Twenty Five Years Later
We study the progress of the theory of accretion disks around black holes in
last twenty five years and explain why advective disks are the best bet in
explaining varied stationary and non-stationary observations from black hole
candidates. We show also that the recently proposed advection dominated flows
are incorrect.Comment: 30 Latex pages including figures. Kluwer Style files included.
Appearing in `Observational Evidence for Black Holes in the Universe', ed.
Sandip K. Chakrabarti, Kluwer Academic Publishers (DORDRECHT: Holland
Giant pulmonary hamartoma
Pulmonary hamartomas are usually an incidental finding and range in size from 1 cm to 8 cm in diameter in various series. We report a case of a massive pulmonary hamartoma (size 25.5 Ă— 17.5 Ă— 6.5 cm and weighing 1134 g) in a 61 year old male who presented with a short history of breathlessness. The tumour was arising from the medial border of the right lung and occupying most of the right chest extending in to the anterior mediastinum. The tumour was compressing the right lung and there was no evidence of infiltration into the surrounding structures. It was successfully treated by surgical resection and final histology was pulmonary hamartoma with predominantly adipose and leiomyomatous differentiation
Naturally split supersymmetry
Nonobservation of superparticles till date, new Higgs mass limits from the
CMS and ATLAS experiments, WMAP constraints on relic density, various other low
energy data, and the naturalness consideration, all considered simultaneously
imply a paradigm shift of supersymmetric model building. In this paper we
perform, for the first time, a detailed numerical study of brane-world induced
supersymmetry breaking for both minimal and next-to-minimal scenarios. We
observe that a naturally hierarchical spectrum emerges through an interplay of
bulk, brane-localized and quasi-localized fields, which can gain more relevance
in the subsequent phases of the LHC run.Comment: 6 pages, 6 eps figures; v2: minor updates, to appear in JHE
The NIH-NIAID Filariasis Research Reagent Resource Center
Filarial worms cause a variety of tropical diseases in humans; however, they are difficult to study because they have complex life cycles that require arthropod intermediate hosts and mammalian definitive hosts. Research efforts in industrialized countries are further complicated by the fact that some filarial nematodes that cause disease in humans are restricted in host specificity to humans alone. This potentially makes the commitment to research difficult, expensive, and restrictive. Over 40 years ago, the United States National Institutes of Health–National Institute of Allergy and Infectious Diseases (NIH-NIAID) established a resource from which investigators could obtain various filarial parasite species and life cycle stages without having to expend the effort and funds necessary to maintain the entire life cycles in their own laboratories. This centralized resource (The Filariasis Research Reagent Resource Center, or FR3) translated into cost savings to both NIH-NIAID and to principal investigators by freeing up personnel costs on grants and allowing investigators to divert more funds to targeted research goals. Many investigators, especially those new to the field of tropical medicine, are unaware of the scope of materials and support provided by the FR3. This review is intended to provide a short history of the contract, brief descriptions of the fiilarial species and molecular resources provided, and an estimate of the impact the resource has had on the research community, and describes some new additions and potential benefits the resource center might have for the ever-changing research interests of investigators
Wavelet packets based denoising method for measurement domain repeat-time multipath filtering in GPS static high-precision positioning
Repeatable satellite orbits can be used for multipath mitigation in GPS-based deformation monitoring and other high-precision GPS applications that involve continuous observation with static antennas. Multipath signals at a static station repeat when the GPS constellation repeats given the same site environment. Repeat-time multipath filtering techniques need noise reduction methods to remove the white noise in carrier phase measurement residuals in order to retrieve the carrier phase multipath corrections for the next day. We propose a generic and robust three-level wavelet packets based denoising method for repeat-time-based carrier phase multipath filtering in relative positioning; the method does not need tuning to work with different data sets. The proposed denoising method is tested rigorously and compared with two other denoising methods. Three rooftop data sets collected at the University of Nottingham Ningbo China and two data sets collected at three Southern California Integrated GPS Network high-rate stations are used in the performance assessment. Test results of the wavelet packets denoising method are compared with the results of the resistor–capacitor (RC) low-pass filter and the single-level discrete wavelet transform (DWT) denoising method. Multipath mitigation efficiency in carrier phase measurement domain is shown by spectrum analysis of two selected satellites in two data sets. The positioning performance of the repeat-time-based multipath filtering techniques is assessed. The results show that the performance of the three noise reduction techniques is about 1–46 % improvement on positioning accuracy when compared with no multipath filtering. The statistical results show that the wavelet packets based denoising method is always better than the RC filter by 2–4 %, and better than the DWT method by 6–15 %. These results suggest that the proposed wavelet packets based denoising method is better than both the DWT method and the relatively simple RC low-pass filter for noise reduction in multipath filtering. However, the wavelet packets based denoising method is not significantly better than the RC filter
Binary and Millisecond Pulsars at the New Millennium
We review the properties and applications of binary and millisecond pulsars.
Our knowledge of these exciting objects has greatly increased in recent years,
mainly due to successful surveys which have brought the known pulsar population
to over 1300. There are now 56 binary and millisecond pulsars in the Galactic
disk and a further 47 in globular clusters. This review is concerned primarily
with the results and spin-offs from these surveys which are of particular
interest to the relativity community.Comment: 59 pages, 26 figures, 5 tables. Accepted for publication in Living
Reviews in Relativity (http://www.livingreviews.org
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