12 research outputs found
Week and weekend day cadence patterns long-term post-bariatric surgery
Obesity can negatively influence walking cadence, reducing the overall intensity of daily activities and increasing the risk of weight gain.
Purpose: Objectively describe the walking cadence of individuals’ long-term post-bariatric surgery.
Methods: Fifty-eight participants, 51.2 ± 8.9 years old, with a BMI of 34.6 ± 10.1 kg/m2, 10.0 ± 3.1 years post-surgery wore an activPAL accelerometer for 7 consecutive days. Data was analyzed using participants’ current BMI, dichotomized by obesity status, < or ≥ 30 kg/m2.
Results: On average, participants walked 5124 ± 2549 steps/day on weekdays and 6097 ± 2786 steps/day on weekend days (p = .003). Participants spent the majority (75%) of their daily steps at a slow-walking average cadence (non-obese: week = 65.3 ± 5.0 steps/min and weekend = 63.8 ± 6.7 steps/min; obese: week = 67.8 ± 8.2 steps/min and weekend = 63.3 ± 6.9 steps/min), with no difference between groups for week or weekend days (p = .153 and .774). The cadence of participants with obesity was significantly lower on weekends compared to weekdays for walking events > 30 s (p = .002) and > 60 s (p = .008) in duration. Weekday cadence of participants without obesity was similar to weekend day cadence across all walking event durations. The majority of walking events occurred below 30 s in duration for all participants.
Conclusions: Long-term post-bariatric surgery, movement occurs in short duration bouts at a slow-walking cadence for the majority of movement. Individuals without obesity had similar movement patterns from week to weekend days while participants with obesity significantly lowered their cadence on weekend days
Nuclear receptor co-activators and HER-2/neu are upregulated in breast cancer patients during neo-adjuvant treatment with aromatase inhibitors
The Confrontation between General Relativity and Experiment
The status of experimental tests of general relativity and of theoretical
frameworks for analysing them is reviewed. Einstein's equivalence principle
(EEP) is well supported by experiments such as the Eotvos experiment, tests of
special relativity, and the gravitational redshift experiment. Future tests of
EEP and of the inverse square law are searching for new interactions arising
from unification or quantum gravity. Tests of general relativity at the
post-Newtonian level have reached high precision, including the light
deflection, the Shapiro time delay, the perihelion advance of Mercury, and the
Nordtvedt effect in lunar motion. Gravitational-wave damping has been detected
in an amount that agrees with general relativity to better than half a percent
using the Hulse-Taylor binary pulsar, and other binary pulsar systems have
yielded other tests, especially of strong-field effects. When direct
observation of gravitational radiation from astrophysical sources begins, new
tests of general relativity will be possible.Comment: 89 pages, 8 figures; an update of the Living Review article
originally published in 2001; final published version incorporating referees'
suggestion
Exploring new physics frontiers through numerical relativity
The demand to obtain answers to highly complex problems within strong-field gravity has been met with significant progress in the numerical solution of Einstein's equations - along with some spectacular results - in various setups. We review techniques for solving Einstein's equations in generic spacetimes, focusing on fully nonlinear evolutions but also on how to benchmark those results with perturbative approaches. The results address problems in high-energy physics, holography, mathematical physics, fundamental physics, astrophysics and cosmology
Varying constants, Gravitation and Cosmology
Fundamental constants are a cornerstone of our physical laws. Any constant
varying in space and/or time would reflect the existence of an almost massless
field that couples to matter. This will induce a violation of the universality
of free fall. It is thus of utmost importance for our understanding of gravity
and of the domain of validity of general relativity to test for their
constancy. We thus detail the relations between the constants, the tests of the
local position invariance and of the universality of free fall. We then review
the main experimental and observational constraints that have been obtained
from atomic clocks, the Oklo phenomenon, Solar system observations, meteorites
dating, quasar absorption spectra, stellar physics, pulsar timing, the cosmic
microwave background and big bang nucleosynthesis. At each step we describe the
basics of each system, its dependence with respect to the constants, the known
systematic effects and the most recent constraints that have been obtained. We
then describe the main theoretical frameworks in which the low-energy constants
may actually be varying and we focus on the unification mechanisms and the
relations between the variation of different constants. To finish, we discuss
the more speculative possibility of understanding their numerical values and
the apparent fine-tuning that they confront us with.Comment: 145 pages, 10 figures, Review for Living Reviews in Relativit