Caffeine Use and Associations with Sleep in Adolescents with and without Attention-Deficit/Hyperactivity Disorder (ADHD)

The objective of this study was to compare caffeine consumption in the morning, afternoon, and evening in adolescents with and without Attention Deficit/Hyperactivity Disorder (ADHD) and examine associations with sleep functioning. Participants were 302 adolescents (ages 12-14) with (n=140) and without (n=162) ADHD. Adolescents wore actigraph watches to assess total sleep time and wake after sleep onset and reported on their sleep-wake problems and the number of caffeinated beverages consumed per day in the morning, afternoon, and evening. Parents reported on adolescents’ difficulties initiating and maintaining sleep. Chi-square analyses, odds ratios, and path analyses were conducted. Analyses controlled for sex, medication status, and pubertal development. Adolescents with ADHD were 2.47 times more likely to consume caffeine in the afternoon and evening than adolescents without ADHD. Path analyses indicated significant associations between afternoon caffeine use and more self-reported sleep problems for adolescents with and without ADHD, and an association between evening caffeine use and self-reported sleep problems only in adolescents with ADHD. Afternoon caffeine use was also associated with parent-reported sleep problems in adolescents with ADHD but not in adolescents without ADHD. Caffeine use was not associated with actigraphy-assessed sleep. This is the first study to show that adolescents with ADHD consume more caffeine than their peers during later times of the day. Additionally, caffeine use is more consistently associated with poorer subjective sleep functioning in adolescents with ADHD compared to adolescents without ADHD. Pediatricians and mental health professionals should assess for caffeine use in adolescents with ADHD and co-occurring sleep problems

Direct reconstruction of dark energy

An important issue in cosmology is reconstructing the effective dark energy equation of state directly from observations. With so few physically motivated models, future dark energy studies cannot only be based on constraining a dark energy parameter space. We present a new non-parametric method which can accurately reconstruct a wide variety of dark energy behaviour with no prior assumptions about it. It is simple, quick and relatively accurate, and involves no expensive explorations of parameter space. The technique uses principal component analysis and a combination of information criteria to identify real features in the data, and tailors the fitting functions to pick up trends and smooth over noise. We find that we can constrain a large variety of w(z) models to within 10-20 % at redshifts z<1 using just SNAP-quality data.Comment: 5 pages, 4 figures. v2 has added refs plus minor changes. To appear in PR

Searching for Lyman alpha emission from a possible Zel'dovich pancake

The detection of 2 x 10(exp 14) solar mass of neutral hydrogen at a redshift of 3.397 has been reported. Top-down theories of structure formation predict such a mass of hydrogen collapsing to form a protocluster of galaxies. We sought to observe this object in Lyman-alpha, which could be produced through ionization by the metagalactic ionizing radiation field or through internal ionization processes. On 29 Apr. 1992, the region of the reported HI emission for 1800 seconds with the 1.3 meter McGraw-Hill reflector at Michigan-Dartmouth-M.I.T. Observatory was observed. Because the H1 emission reported has a transverse scale of 300 sec, a 1/3.06 reducing camera and a Thomson CCD were used to obtain a field of view of about 600 sec by 840 sec. A filter 88 A wide, centered at 5354 A was used; Lyman-alpha emission at z = 3.4 is redshifted to 5347 A. In order to avoid saturating the CCD with a bright star in the field, nine 200 second exposures were taken. The combination of these images shows no obvious extended Lyman-alpha emission at a level of about 28 magnitudes per square arcsecond. The field observed also shows a distant cluster of galaxies. In order to determine if the cluster could in any way be associated with the cloud of neutral hydrogen at z = 3.4, we sought to estimate its redshift from the size and magnitude of the galaxies and of the cluster as a whole. Omega = 1 and H(sub O) = 50 km s(sup -1) Mpc(sup -1) were adopted; our redshift estimates range from z = 0.2 to z = 0.6. The cluster is clearly not associated with the HI cloud at z = 3.4

On the global warping of a thin self-gravitating near Keplerian gaseous disk with application to the disk in NGC 4258

On the global warping of a thin self-gravitating near Keplerian gaseous disk with application to the disk in NGC 4258Comment: 36 pages (including 4 figures), Latex, to appear in Ap

Entanglement purification protocols for all graph states

We present multiparty entanglement purification protocols that are capable of purifying arbitrary graph states directly. We develop recurrence and breeding protocols and compare our methods with strategies based on bipartite entanglement purification in static and communication scenarios. We find that direct multiparty purification is of advantage with respect to achievable yields and minimal required fidelity in static scenarios, and with respect to obtainable fidelity in the case of noisy operations in both scenarios.Comment: revtex 10 pages, 6 figure

Identification of group B respiratory syncytial viruses that lack the 60-nucleotide duplication after six consecutive epidemics of total BA dominance at coastal Kenya

Respiratory syncytial virus BA genotype has reportedly replaced other group B genotypes worldwide. We report the observation of three group B viruses, all identical in G sequence but lacking the BA duplication, at a coastal district hospital in Kenya in early 2012. This follows a period of six consecutive respiratory syncytial virus (RSV) epidemics with 100% BA dominance among group B isolates. The new strains appear only distantly related to BA variants and to previously circulating SAB1 viruses last seen in the district in 2005, suggesting that they were circulating elsewhere undetected. These results are of relevance to an understanding of RSV persistence

New composite models of partially ionized protoplanetary disks

We study an accretion disk in which three different regions may coexist: MHD turbulent regions, dead zones and gravitationally unstable regions. Although the dead zones are stable, there is some transport due to the Reynolds stress associated with waves emitted from the turbulent layers. We model the transport in each of the different regions by its own $\alpha$ parameter, this being 10 to $10^{3}$ times smaller in dead zones than in active layers. In gravitationally unstable regions, $\alpha$ is determined by the fact that the disk self-adjusts to a state of marginal stability. We construct steady-state models of such disks. We find that for uniform mass flow, the disk has to be more massive, hotter and thicker at the radii where there is a dead zone. In disks in which the dead zone is very massive, gravitational instabilities are present. Whether such models are realistic or not depends on whether hydrodynamical fluctuations driven by the turbulent layers can penetrate all the way inside the dead zone. This may be more easily achieved when the ratio of the mass of the active layer to that of the dead zone is relatively large, which in our models corresponds to $\alpha$ in the dead zone being about 10% of $\alpha$ in the active layers. If the disk is at some stage of its evolution not in steady-state, then the surface density will evolve toward the steady-state solution. However, if $\alpha$ in the dead zone is much smaller than in the active zone, the timescale for the parts of the disk beyond a few AU to reach steady-state may become longer than the disk lifetime. Steady-state disks with dead zones are a more favorable environment for planet formation than standard disks, since the dead zone is typically 10 times more massive than a corresponding turbulent zone at the same location.Comment: 13 pages, 5 figures, accepted for publication in Ap

A Wii Bit of Fun: A Novel Platform to Deliver Effective Balance Training to Older Adults

BACKGROUND: Falls and fall-related injuries are symptomatic of an aging population. This study aimed to design, develop, and deliver a novel method of balance training, using an interactive game-based system to promote engagement, with the inclusion of older adults at both high and low risk of experiencing a fall.STUDY DESIGN: Eighty-two older adults (65 years of age and older) were recruited from sheltered accommodation and local activity groups. Forty volunteers were randomly selected and received 5 weeks of balance game training (5 males, 35 females; mean, 77.18 ± 6.59 years), whereas the remaining control participants recorded levels of physical activity (20 males, 22 females; mean, 76.62 ± 7.28 years). The effect of balance game training was measured on levels of functional balance and balance confidence in individuals with and without quantifiable balance impairments.RESULTS: Balance game training had a significant effect on levels of functional balance and balance confidence (P Peer reviewedFinal Published versio

Determining the Protective Effects of Quercetin Against Cadmium Toxicity in Human Embryonic Kidney Cells

Cadmium is a toxic industrial and environmental pollutant found in groundwater, air, soils, food and cigarettes. Chronic intake of low levels of cadmium has been shown to result in renal dysfunction due to cell death which can occur via apoptosis as well as necrosis. Previous studies have shown that plant extracts containing quercetin, a flavonoid found in many fruits and vegetables, protect against cadmium toxicity in rat liver hepatocytes. To determine if quercetin may have a protective effect in a cadmium-treated human embryonic kidney cell line, HEK-293 cells were treated using concentrations of cadmium chloride from 10 to 50 μM for 24 hours. Using a cell proliferation assay, it was determined that cadmium chloride inhibited cellular proliferation in a concentration dependent manner. For further studies, 30 μM cadmium chloride was used since it inhibited growth by 31.98%. Pretreating cells for 24 hours before cadmium exposure with concentrations of 10 μM to 200 μM quercetin suggested that this flavonoid partially protects HEK-293 cells from cadmium toxicity at all levels of treatment. While these results suggest a protective effect, it is unclear if quercetin is inhibiting a cadmium-induced apoptotic or necrotic pathway. Previous studies have suggested that cadmium-induced apoptosis increases levels of p47phox, one of the subunits of NADPH oxidase. To determine if quercetin reduces p47phox expression, HEK-293 cells were pretreated for 24 hours before cadmium treatment, and immunoblot analysis was used to determine p47phox expression. Preliminary results suggest that quercetin does not reduce p47phox levels and therefore, may not specifically inhibit cadmium-induced apoptosis