2,430 research outputs found
Discretizing Gravity in Warped Spacetime
We investigate the discretized version of the compact Randall-Sundrum model.
By studying the mass eigenstates of the lattice theory, we demonstrate that for
warped space, unlike for flat space, the strong coupling scale does not depend
on the IR scale and lattice size. However, strong coupling does prevent us from
taking the continuum limit of the lattice theory. Nonetheless, the lattice
theory works in the manifestly holographic regime and successfully reproduces
the most significant features of the warped theory. It is even in some respects
better than the KK theory, which must be carefully regulated to obtain the
correct physical results. Because it is easier to construct lattice theories
than to find exact solutions to GR, we expect lattice gravity to be a useful
tool for exploring field theory in curved space.Comment: 17 pages, 4 figures; references adde
SOLUTIONS OF THE LANDAU-VLASOV EQUATION IN NUCLEAR PHYSICS
The properties of Vlasov equation solutions obtained by projection on coherent state basis are discussed. Such solutions satisfy stationarity conditions and satisfactorily describe the average diffusivity of nuclear phase space and reproduce the bulk properties of nuclei. Sampling methods and their effects on dynamics are discussed for the study of heavy ion reactions at intermediate energies. The non-local Gogny force is easily computable on this basis which allows to use it for dynamical nuclear studies
PHASE SPACE DYNAMICS OF HEAVY ION NUCLEAR COLLISIONS IN THE FERMI ENERGY DOMAIN
No abstract availabl
An Electromyographic and Electrogoniometric Study of Stair Climbing with and without the Use of the Ez-StepÂŞ and the Quad-StepÂŞ
Purpose: The purpose of this study is to compare lower extremity muscle activity along with hip and knee ROM in an elderly population on stair ascent and descent using the EZ-StepTM and Quad-StepTM in comparison to traditional stair climbing.
Subjects: Twenty nine male and female adults volunteered for this study. Inclusion criteria included those 65 years of age and older, ability to climb three flights of standard stairs, and upper extremity strength to be able to manipulate the Quad-Step TM.
Instrumentation: The EZ-StepTM and Quad-StepTM are devices that decrease stair step height by one-half. The EMG activity and ROM was recorded using a Noraxon TeleMy0900 telemetry unit. The goniometers that were used were Biometrics SG110 twin axis goniometers.
Procedure: EMG activity was recorded with surface electrodes over the rectus femoris, biceps femoris, gluteus maximus, and gastrocnemius. Electrogoniometers were placed at the knee and hip to record ROM during the stair climbing activities. There were three randomly selected stair-climbing trials in the study: 1) Quad-StepTM, 2) EZ-StepTM, and 3) traditional stairs.
Data Analysis: A repeated measures analysis of variance (ANOVA) was used to analyze the data collected. The significance was set at an alpha level of .05.
Results: The study found significantly less EMG activity in all four muscles with the EZ-Step TM and Quad-Step TM devices during stair ascent and stair descent, except for the BF with the use of the Quad-Step TM during stair descent. A significant difference in hip ROM was found for stair ascent, but not forstair descent. On both stair ascent and descent, significantly less knee ROM was required.
Conclusion and Clinical Implication: The EZ-Step 1M and Quad-Step 1M may make stair climbing easier for older individuals who have difficulty with this task
Incidence of depression and associated factors in patients with type 2 diabetes in Quebec, Canada
It has been reported that the risk of depression is higher among people with type 2 diabetes compared with a nondiabetic population. Among diabetic patients, depression has been associated with worse self-care behaviors, poor glycemic control, and an increased risk of diabetes complications. Identifying factors associated with the occurrence of depression may help physicians identify earlier diabetic patients at a high risk of developing depression, improve prevention, and accelerate proper treatment. To our knowledge, very few population-based studies have reported on the incidence of clinically diagnosed depression as a consequence of type 2 diabetes over a long follow-up period. The objective of this study was to estimate the incidence of clinically diagnosed depression among type 2 diabetic patients newly treated with oral antidiabetic drugs (ADs) and to identify factors associated with the occurrence of depression. Administrative claims data from the public health insurance plan were used to identify a cohort of new oral AD users aged ≥18 years between 2000 and 2006. Patients were followed from oral AD treatment initiation until the diagnosis of depression, ineligibility for the public drug plan, death, or the end of the study, whichever came first. Incidence rates were determined using person-time analysis. Factors associated with depression were identified using multivariable Cox regression analysis. We identified 114,366 new oral AD users, of which 4808 had a diagnosis of depression. The overall incidence rate of depression was 9.47/1000 person-years (PYs) (10.72/1000 PYs for women and 8.27/1000 PYs for men). The incidence of depression was higher during the year after oral AD treatment initiation. Independent factors associated with depression included having had mental disorders other than depression, hospitalization, a higher number of different drugs taken and of physicians visited during the year before oral AD initiation. Moreover, we observed a statistically significant age-by-socioeconomic status interaction. The incidence of diagnosed depression is higher during the first year after oral AD treatment initiation. Clinicians could pay particular attention to women, patients starting an AD at a young age, those with a low socioeconomic status, and especially those with a history of anxiety or dementia
LOW AND INTERMEDIATE ENERGY HEAVY ION COLLISIONS IN THE SEMI-CLASSICAL MICROSCOPIC DESCRIPTION
It is shown how peripheral and central heavy-ion collisions can be described by Landau-Vlasov dynamics. For peripheral collisions at intermediate energies, mass-mass correlations, ejectile mean energies and angular distributions are obtained and compared with fragmentation data. For central collisions, one shows that the collision term destroys the TDHF property of transparency at low impact parameters for collisions close from the Coulomb barrier. Above 20 MeV/u incomplete fusion is described with associated linear momentum transfer and nuclear deformations. One exhibits how coupling to the continuum is obtained in Vlasov and Landau-Vlasov dynamics. Coulomb interaction being taken into account, we present also results concerning the isospin transfer and the excitation of the isovector dipole mode near and well above the Coulomb barrier. Some perspectives to further studies of physical observables are finally drawn
Adaptive latitudinal variation in Common Blackbird Turdus merula nest characteristics
Nest construction is taxonomically widespread, yet our understanding of adaptive
intraspecific variation in nest design remains poor. Nest characteristics are
expected to vary adaptively in response to predictable variation in spring temperatures
over large spatial scales, yet such variation in nest design remains largely
overlooked, particularly amongst open-cup-nesting birds. Here, we systematically
examined the effects of latitudinal variation in spring temperatures and precipitation
on the morphology, volume, composition, and insulatory properties of
open-cup-nesting Common Blackbirds’ Turdus merula nests to test the hypothesis
that birds living in cooler environments at more northerly latitudes would build
better insulated nests than conspecifics living in warmer environments at more
southerly latitudes. As spring temperatures increased with decreasing latitude, the
external diameter of nests decreased. However, as nest wall thickness also
decreased, there was no variation in the diameter of the internal nest cups. Only
the mass of dry grasses within nests decreased with warmer temperatures at lower
latitudes. The insulatory properties of nests declined with warmer temperatures at
lower latitudes and nests containing greater amounts of dry grasses had higher insulatory
properties. The insulatory properties of nests decreased with warmer temperatures
at lower latitudes, via changes in morphology (wall thickness) and
composition (dry grasses). Meanwhile, spring precipitation did not vary with latitude,
and none of the nest characteristics varied with spring precipitation. This suggests
that Common Blackbirds nesting at higher latitudes were building nests with
thicker walls in order to counteract the cooler temperatures. We have provided evidence
that the nest construction behavior of open-cup-nesting birds systematically
varies in response to large-scale spatial variation in spring temperatures
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