7,535 research outputs found
The potential therapeutic effects of creatine supplementation on body composition and muscle function in cancer
Low muscle mass in individuals with cancer has a profound impact on quality of life and independence and is associated with greater treatment toxicity and poorer prognosis. Exercise interventions are regularly being investigated as a means to ameliorate treatment-related adverse effects, and nutritional/supplementation strategies to augment adaptations to exercise are highly valuable. Creatine (Cr) is a naturally-occurring substance in the human body that plays a critical role in energy provision during muscle contraction. Given the beneficial effects of Cr supplementation on lean body mass, strength, and physical function in a variety of clinical populations, there is therapeutic potential in individuals with cancer at heightened risk for muscle loss. Here, we provide an overview of Cr physiology, summarize the evidence on the use of Cr supplementation in various aging/clinical populations, explore mechanisms of action, and provide perspectives on the potential therapeutic role of Cr in the exercise oncology setting
Hidden Order in Crackling Noise during Peeling of an Adhesive Tape
We address the long standing problem of recovering dynamical information from
noisy acoustic emission signals arising from peeling of an adhesive tape
subject to constant traction velocity. Using phase space reconstruction
procedure we demonstrate the deterministic chaotic dynamics by establishing the
existence of correlation dimension as also a positive Lyapunov exponent in a
mid range of traction velocities. The results are explained on the basis of the
model that also emphasizes the deterministic origin of acoustic emission by
clarifying its connection to sticks-slip dynamics.Comment: 5 pages, 10 figure
Spreading of Latex Particles on a Substrate
We have investigated both experimentally and theoretically the spreading
behavior of latex particles deposited on solid substrates. These particles,
which are composed of cross-linked polymer chains, have an intrinsic elastic
modulus. We show that the elasticity must be considered to account for the
observed contact angle between the particle and the solid substrate, as
measured through atomic force microscopy techniques. In particular, the work of
adhesion computed within our model can be significantly larger than that from
the classical Dupr\'{e} formula.Comment: 7 pages, 7 figures, to appear in Europhys. Let
Update: Accurate Determinations of alpha_s from Realistic Lattice QCD
We use lattice QCD simulations, with MILC configurations (including vacuum
polarization from u, d, and s quarks), to update our previous determinations of
the QCD coupling constant. Our new analysis uses results from 6 different
lattice spacings and 12 different combinations of sea-quark masses to
significantly reduce our previous errors. We also correct for
finite-lattice-spacing errors in the scale setting, and for nonperturbative
chiral corrections to the 22 short-distance quantities from which we extract
the coupling. Our final result is alpha_V(7.5GeV,nf=3) = 0.2120(28), which is
equivalent to alpha_msbar(M_Z,n_f=5)= 0.1183(8). We compare this with our
previous result, which differs by one standard deviation.Comment: 12 pages, 2 figures, 4 table
Drying and cracking mechanisms in a starch slurry
Starch-water slurries are commonly used to study fracture dynamics. Drying
starch-cakes benefit from being simple, economical, and reproducible systems,
and have been used to model desiccation fracture in soils, thin film fracture
in paint, and columnar joints in lava. In this paper, the physical properties
of starch-water mixtures are studied, and used to interpret and develop a
multiphase transport model of drying. Starch-cakes are observed to have a
nonlinear elastic modulus, and a desiccation strain that is comparable to that
generated by their maximum achievable capillary pressure. It is shown that a
large material porosity is divided between pore spaces between starch grains,
and pores within starch grains. This division of pore space leads to two
distinct drying regimes, controlled by liquid and vapor transport of water,
respectively. The relatively unique ability for drying starch to generate
columnar fracture patterns is shown to be linked to the unusually strong
separation of these two transport mechanisms.Comment: 9 pages, 8 figures [revised in response to reviewer comments
Drying and cracking mechanisms in a starch slurry
Starch-water slurries are commonly used to study fracture dynamics. Drying
starch-cakes benefit from being simple, economical, and reproducible systems,
and have been used to model desiccation fracture in soils, thin film fracture
in paint, and columnar joints in lava. In this paper, the physical properties
of starch-water mixtures are studied, and used to interpret and develop a
multiphase transport model of drying. Starch-cakes are observed to have a
nonlinear elastic modulus, and a desiccation strain that is comparable to that
generated by their maximum achievable capillary pressure. It is shown that a
large material porosity is divided between pore spaces between starch grains,
and pores within starch grains. This division of pore space leads to two
distinct drying regimes, controlled by liquid and vapor transport of water,
respectively. The relatively unique ability for drying starch to generate
columnar fracture patterns is shown to be linked to the unusually strong
separation of these two transport mechanisms.Comment: 9 pages, 8 figures [revised in response to reviewer comments
A Comparison of Anxiety Levels Among College Students
The purpose of this causal-comparative study was to compare the differences in anxiety levels among college students by their classification, gender, major, and semester hours taken. Participants were a convenience sample of 113 undergraduate and graduate college students, and were from 22 universities primarily located in the southeastern region of the United States. The participants completed a survey in which they selected their classification, gender, major, number of semester hours taken, race, ethnicity, and native language. The survey also included 20 Likert-scaled questions from the Zung Self-rating Anxiety Scale (Zung, 1971) that measured levels of anxiety based on symptoms experienced by the individual. An analysis of the results revealed that there is no significant difference in anxiety levels among college students of different classifications or by the number of semester hours taken. However, the results also revealed that there is a significant difference in anxiety levels among male and female college students and students with different majors
A Prediction of the B*_c mass in full lattice QCD
By using the Highly Improved Staggered Quark formalism to handle charm,
strange and light valence quarks in full lattice QCD, and NRQCD to handle
bottom valence quarks we are able to determine accurately ratios of the B meson
vector-pseudoscalar mass splittings, in particular,
(m(B*_c)-m(B_c))/(m(B*_s)-m(B_s)). We find this ratio to be 1.15(15), showing
the `light' quark mass dependence of this splitting to be very small. Hence we
predict m(B_c*) = 6.330(7)(2)(6) GeV where the first two errors are from the
lattice calculation and the third from existing experiment. This is the most
accurate prediction of a gold-plated hadron mass from lattice QCD to date.Comment: 4 pages, 2 figure
What is the clinical workup for failure to thrive?
The clinical evaluation of failure to thrive (FTT) includes a thorough history and physical examination; observation of parent-child interactions; observation and documentation of the child's feeding patterns; and a home visit by an appropriately trained health care professional (Strength of Recommendation [SOR]: C). Further diagnostic testing should be performed as indicated by positive findings from the history and physical exam or if the child's weight has not improved at follow-up (SOR: C)
On the nature of surface roughness with application to contact mechanics, sealing, rubber friction and adhesion
Surface roughness has a huge impact on many important phenomena. The most
important property of rough surfaces is the surface roughness power spectrum
C(q). We present surface roughness power spectra of many surfaces of practical
importance, obtained from the surface height profile measured using optical
methods and the Atomic Force Microscope. We show how the power spectrum
determines the contact area between two solids. We also present applications to
sealing, rubber friction and adhesion for rough surfaces, where the power
spectrum enters as an important input.Comment: Topical review; 82 pages, 61 figures; Format: Latex (iopart). Some
figures are in Postscript Level
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