875 research outputs found
Contextual barriers to mobile health technology in African countries: a perspective piece
On a global scale, healthcare practitioners are now beginning to move from traditional desktop-based computer technologies towards mobile computing environments[1]. Consequently, such environments have received immense attention from both academia and industry, in order to explore these promising opportunities, apparent limitations, and implications for both theory and practice[2]. The application of mobile IT within a medical context, referred to as mobile health or mHealth, has revolutionised the delivery of healthcare services as mobile technologies offer the potential of retrieving, modifying and entering patient-related data/information at the point-of-care. As a component of the larger health informatics domain mHealth may be referred as all portable computing devices (e.g. mobile phones, mobile clinical assistants and medical sensors) used in a healthcare context to support the delivery of healthcare services
TO EXAMINE THE DIFFERENCES IN REARFOOT KINEMATICS DURING TREADMILL AND OVERGROUND RUNNING
This study examined the differences between the kinematics of rearfoot motion in overground (OG) and treadmill (TM) running. Two subjects ran at various speeds under both conditions and a three-dimensional analysis was performed using the Peak Motus Analysis system. TM running produced repeatable and consistent measures of rearfoot motion across all speeds however OG running was more variable. While there are some differences between the two modes, this can be explained by TM mechanics and TM testing cannot be dismissed based on this. Speed was found to influence most variables making speed control critical in obtaining reliable measures of rearfoot motion. The TM easily and accurately provides this, which advocates its use in locomotion studies. It was concluded that speed control is more important than the mode of runnin
Absorptive part of meson--baryon scattering amplitude and baryon polarization in chiral perturbation theory
We compute the spin asymmetry and polarization of the final-state baryon in
its rest frame in two-body meson--baryon low-energy scattering with unpolarized
initial state, to lowest non-trivial order in BChPT. The required absorptive
amplitudes are obtained analytically at one-loop level. We discuss the
polarization results numerically for several meson--baryon processes. Even at
low energies above threshold, where BChPT can reasonably be expected to be
applicable, sizable values of polarization are found for some processes
Fermion masses in noncommutative geometry
Recent indications of neutrino oscillations raise the question of the
possibility of incorporating massive neutrinos in the formulation of the
Standard Model (SM) within noncommutative geometry (NCG). We find that the NCG
requirement of Poincare duality constrains the numbers of massless quarks and
neutrinos to be unequal unless new fermions are introduced. Possible scenarios
in which this constraint is satisfied are discussed.Comment: 4 pages, REVTeX; typos are corrected in (19), "Possible Solutions"
and "Conclusion" are modified; additional calculational details are included;
references are update
On the Ultraviolet Behaviour of Newton's constant
We clarify a point concerning the ultraviolet behaviour of the Quantum Field
Theory of gravity, under the assumption of the existence of an ultraviolet
Fixed Point. We explain why Newton's constant should to scale like the inverse
of the square of the cutoff, even though it is technically inessential. As a
consequence of this behaviour, the existence of an UV Fixed Point would seem to
imply that gravity has a built-in UV cutoff when described in Planck units, but
not necessarily in other units.Comment: 8 pages; CQG class; minor changes and rearrangement
Strangeness spin, magnetic moment and strangeness configurations of the proton
The implications of the empirical signatures for the positivity of the
strangeness magnetic moment , and the negativity of the strangeness
contribution to the proton spin , on the possible
configurations of five quarks in the proton are analyzed. The empirical signs
for the values of these two observables can only be obtained in configurations
where the system is orbitally excited and the quark is in the
ground state. The configurations, in which the is orbitally excited,
which include the conventional congfiguration, with the
exception of that, in which the component has spin 2, yield negative
values for . Here the strangeness spin , the strangeness
magnetic moment and the axial coupling constant are calculated
for all possible configurations of the component of the proton. In
the configuration with flavor-spin symmetry, which is
likely to have the lowest energy, is positive and .Comment: 17 page
Weak Hyperon Decays: Quark Sea and SU(3) Symmetry Breaking
An explanation of the difference in the values of the apparent ratios
for the S- and P- wave amplitudes of nonleptonic hyperon decays is proposed.
The argument is formulated in the framework of the standard pole model with
ground-state and excited baryons as intermediate
states for the P- and S- waves respectively. Under the assumption that the
dominant part of the deviation of from is due to large
quark sea effects, symmetry breaking in energy denominators is shown to
lead to a prediction for which is in excellent agreement with
experiment. This corroborates our previous unitarity calculations which
indicated that the matrix elements of the parity
conserving weak Hamiltonian between the ground-state baryons are characterized
by or more. A brief discussion of the problem of the
relative size of S- and P- wave amplitudes is given. Finally, implications for
weak radiative hyperon decays are also discussed.Comment: 26 pages, LATEX, 1647/PH IFJ Krako
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Explosive Radiation of Malpighiales Supports a Mid-Cretaceous Origin of Modern Tropical Rain Forests
Fossil data have been interpreted as indicating that Late Cretaceous tropical forests were open and dry adapted and that modern closed-canopy rain forest did not originate until after the Cretaceous-Tertiary (K/T) boundary. However, some mid-Cretaceous leaf floras have been interpreted as rain forest. Molecular divergence-time estimates within the clade Malpighiales, which constitute a large percentage of species in the shaded, shrub, and small tree layer in tropical rain forests worldwide, provide new tests of these hypotheses. We estimate that all 28 major lineages (i.e., traditionally recognized families) within this clade originated in tropical rain forest well before the Tertiary, mostly during the Albian and Cenomanian (112 - 94 Ma). Their rapid rise in the mid-Cretaceous may have resulted from the origin of adaptations to survive and reproduce under a closed forest canopy. This pattern may also be paralleled by other similarly diverse lineages and supports fossil indications that closed-canopy tropical rain forests existed well before the K/T boundary. This case illustrates that dated phylogenies can provide an important new source of evidence bearing on the timing of major environmental changes, which may be especially useful when fossil evidence is limited or controversial.Organismic and Evolutionary Biolog
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