331 research outputs found
Relationship between membrane potential and respiration rate in isolated liver mitochondria from rats fed an energy dense diet.
Unequal charge separation by different coupling spans of the mitochondrial electron transport chain
High exercise levels are related to favorable sleep patterns and psychological functioning in adolescents: A comparison of athletes and controls
Abstract Purpose: To investigate whether chronic vigorous exercising is related to improved sleep and psychological functioning, and whether this association varies with gender. Both lay and scientific opinions hold that physical activity is an efficient remedy and preventative measure for poor sleep. However, empirical evidence on adolescents is very limited. Adolescence is characterized by important changes in sleep behavior. Even though adolescents still require 9 to 10 hours of sleep per night There is a bi-directional relationship between acute [8] and chronic To cope with poor sleep, clinical experience indicates a growing reliance on substances, either to induce sleep (alcohol, cannabis) or to reduce daytime sleepiness (caffeine)
Superfluid toroidal currents in atomic condensates
The dynamics of toroidal condensates in the presence of condensate flow and
dipole perturbation have been investigated. The Bogoliubov spectrum of
condensate is calculated for an oblate torus using a discrete-variable
representation and a spectral method to high accuracy. The transition from
spheroidal to toroidal geometry of the trap displaces the energy levels into
narrow bands. The lowest-order acoustic modes are quantized with the dispersion
relation with . A condensate
with toroidal current splits the co-rotating and
counter-rotating pair by the amount: . Radial dipole excitations are the lowest energy dissipation modes.
For highly occupied condensates the nonlinearity creates an asymmetric mix of
dipole circulation and nonlinear shifts in the spectrum of excitations so that
the center of mass circulates around the axis of symmetry of the trap. We
outline an experimental method to study these excitations.Comment: 8 pages, 8 figure
Chemostratigraphy of Neoproterozoic carbonates: implications for 'blind dating'
The delta C-13(carb) and Sr-87/Sr-86 secular variations in Neoproteozoic seawater have been used for the purpose of 'isotope stratigraphy' but there are a number of problems that can preclude its routine use. In particular, it cannot be used with confidence for 'blind dating'. The compilation of isotopic data on carbonate rocks reveals a high level of inconsistency between various carbon isotope age curves constructed for Neoproteozoic seawater, caused by a relatively high frequency of both global and local delta C-13(carb) fluctuations combined with few reliable age determinations. Further complication is caused by the unresolved problem as to whether two or four glaciations, and associated negative delta C-13(carb) excursions, can be reliably documented. Carbon isotope stratigraphy cannot be used alone for geological correlation and 'blind dating'. Strontium isotope stratigraphy is a more reliable and precise tool for stratigraphic correlations and indirect age determinations. Combining strontium and carbon isotope stratigraphy, several discrete ages within the 590-544 Myr interval, and two age-groups at 660-610 and 740-690 Myr can be resolved
The Potts Fully Frustrated model: Thermodynamics, percolation and dynamics in 2 dimensions
We consider a Potts model diluted by fully frustrated Ising spins. The model
corresponds to a fully frustrated Potts model with variables having an integer
absolute value and a sign. This model presents precursor phenomena of a glass
transition in the high-temperature region. We show that the onset of these
phenomena can be related to a thermodynamic transition. Furthermore this
transition can be mapped onto a percolation transition. We numerically study
the phase diagram in 2 dimensions (2D) for this model with frustration and {\em
without} disorder and we compare it to the phase diagram of the model with
frustration {\em and} disorder and of the ferromagnetic model.
Introducing a parameter that connects the three models, we generalize the exact
expression of the ferromagnetic Potts transition temperature in 2D to the other
cases. Finally, we estimate the dynamic critical exponents related to the Potts
order parameter and to the energy.Comment: 10 pages, 10 figures, new result
Spectroscopic examinations of hydro- and glaciovolcanic basaltic tuffs: Modes of alteration and relevance for Mars
Hydro- and glaciovolcanism are processes that have taken place on both Earth and Mars. The amount of materials produced by these processes that are present in the martian surface layer is unknown, but may be substantial. We have used Mars rover analogue analysis techniques to examine altered tuff samples collected from multiple hydrovolcanic features, tuff rings and tuff cones, in the American west and from glaciovolcanic hyaloclastite ridges in Washington state and in Iceland. Analysis methods include VNIR-SWIR reflectance, MWIR thermal emissivity, thin section petrography, XRD, XRF, and Mössbauer spectroscopy. We distinguish three main types of tuff that differ prominently in petrography and VNIR-SWIR reflectance: minimally altered sideromelane tuff, gray to brown colored smectite-bearing tuff, and highly palagonitized tuff. Differences are also observed between the tuffs associated with hydrovolcanic tuff rings and tuff cones and those forming glaciovolcanic hyaloclastite ridges. For the locations sampled, hydrovolcanic palagonite tuffs are more smectite and zeolite rich while the palagonitized hyaloclastites from the sampled sites are largely devoid of zeolites and relatively lacking in smectites as well. The gray to brown colored tuffs are only observed in the hydrovolcanic deposits and appear to represent a distinct alteration pathway, with formation of smectites without associated palagonite formation. This is attributed to lower temperatures and possibly longer time scale alteration. Altered hydro- or glaciovolcanic materials might be recognized on the surface of Mars with rover-based instrumentation based on the results of this study
Microlensing as a probe of the Galactic structure; 20 years of microlensing optical depth studies
Microlensing is now a very popular observational astronomical technique. The
investigations accessible through this effect range from the dark matter
problem to the search for extra-solar planets. In this review, the techniques
to search for microlensing effects and to determine optical depths through the
monitoring of large samples of stars will be described. The consequences of the
published results on the knowledge of the Milky-Way structure and its dark
matter component will be discussed. The difficulties and limitations of the
ongoing programs and the perspectives of the microlensing optical depth
technique as a probe of the Galaxy structure will also be detailed.Comment: Accepted for publication in General Relativity and Gravitation.
General Relativity and Gravitation in press (2010) 0
Individual goal-oriented cognitive rehabilitation to improve everyday functioning for people with early-stage dementia: a multi-centre randomised controlled trial (the GREAT trial)
YesObjectives: To determine whether individual goal-oriented cognitive rehabilitation (CR) improves
everyday functioning for people with mild-to-moderate dementia.
Design and methods: Parallel group multi-centre single-blind randomised controlled trial (RCT)
comparing CR added to usual treatment (CR) with usual treatment alone (TAU) for people with an
ICD-10 diagnosis of Alzheimer’s, vascular or mixed dementia and mild-to-moderate cognitive
impairment (MMSE score ≥ 18), and with a family member willing to contribute. Participants
allocated to CR received ten weekly sessions over three months and four maintenance sessions over
six months. Participants were followed up three and nine months post-randomisation by blinded
researchers. The primary outcome was self-reported goal attainment at three months. Secondary
outcomes at three and nine months included informant-reported goal attainment, quality of life, mood,
self-efficacy, and cognition, and study partner stress and quality of life.
Results: We randomised (1:1) 475 people with dementia; 445 (CR=281) were included in the
intention to treat analysis at three months, and 426 (CR=208) at nine months. At three months there
were statistically-significant large positive effects for participant-rated goal attainment (d=0.97, 95%
CI 0.75 to 1.19), corroborated by informant ratings (d=1.11, 0.89 to 1.34). These effects were
maintained at nine months for both participant (d=0.94, 0.71 to 1.17) and informant ratings (d=0.96,
0.73 to 1.2). The observed gains related to goals directly targeted in the therapy. There were no
significant differences in secondary outcomes.
Conclusions: Cognitive rehabilitation enables people with early-stage dementia to improve their
everyday functioning in relation to individual goals targeted in the therapy.National Institute for Health, Health Technology Assessment Programme, Grant/Award Number: 11/15/0
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