240 research outputs found
African American Disparities within the Medical World
There are many challenges that African Americans face and the lack of quality in care towards African Americans is an ongoing problem. Black men and women are not given the same care compared to their white counterparts. African Americans are faced with numerous disparities in the medical world. This can exist due to factors that are out of their control such as; failure of medical professionals recognizing the sociocultural differences, distrust in the health care system, cultural differences in understanding and explaining illness, history of hospital and medical office segregation, and knowledge of available services. It is very unlikely to eliminate social inequalities in health care but educating the people about this is important. Colorblindness is not always the answer because people need to be seen for who they are because someone’s background can determine certain health statuses
Towards an -theorem for granular gases
The -theorem, originally derived at the level of Boltzmann non-linear
kinetic equation for a dilute gas undergoing elastic collisions, strongly
constrains the velocity distribution of the gas to evolve irreversibly towards
equilibrium. As such, the theorem could not be generalized to account for
dissipative systems: the conservative nature of collisions is an essential
ingredient in the standard derivation. For a dissipative gas of grains, we
construct here a simple functional related to the original ,
that can be qualified as a Lyapunov functional. It is positive, and results
backed by three independent simulation approaches (a deterministic spectral
method, the stochastic Direct Simulation Monte Carlo technique, and Molecular
Dynamics) indicate that it is also non-increasing. Both driven and unforced
cases are investigated
Self-Similarity for Ballistic Aggregation Equation
We consider ballistic aggregation equation for gases in which each particle
is iden- ti?ed either by its mass and impulsion or by its sole impulsion. For
the constant aggregation rate we prove existence of self-similar solutions as
well as convergence to the self-similarity for generic solutions. For some
classes of mass and/or impulsion dependent rates we are also able to estimate
the large time decay of some moments of generic solutions or to build some new
classes of self-similar solutions
Tanaka Theorem for Inelastic Maxwell Models
We show that the Euclidean Wasserstein distance is contractive for inelastic
homogeneous Boltzmann kinetic equations in the Maxwellian approximation and its
associated Kac-like caricature. This property is as a generalization of the
Tanaka theorem to inelastic interactions. Consequences are drawn on the
asymptotic behavior of solutions in terms only of the Euclidean Wasserstein
distance
Cooling process for inelastic Boltzmann equations for hard spheres, Part II: Self-similar solutions and tail behavior
We consider the spatially homogeneous Boltzmann equation for inelastic hard
spheres, in the framework of so-called constant normal restitution
coefficients. We prove the existence of self-similar solutions, and we give
pointwise estimates on their tail. We also give general estimates on the tail
and the regularity of generic solutions. In particular we prove Haff 's law on
the rate of decay of temperature, as well as the algebraic decay of
singularities. The proofs are based on the regularity study of a rescaled
problem, with the help of the regularity properties of the gain part of the
Boltzmann collision integral, well-known in the elastic case, and which are
extended here in the context of granular gases.Comment: 41 page
Predictive models of syncope causes in an outpatient clinic
The investigation of unexplained syncope remains a challenging clinical problem. In the present study we sought to evaluate the diagnostic value of a standardized work-up focusing on non invasive tests in patients with unexplained syncope referred to a syncope clinic, and whether certain combinations of clinical parameters are characteristic of rhythmic and reflex causes of syncope. METHODS AND RESULTS: 317 consecutive patients underwent a standardized work-up including a 12-lead ECG, physical examination, detailed history with screening for syncope-related symptoms using a structured questionnaire followed by carotid sinus massage (CSM), and head-up tilt test. Invasive testings including an electrophysiological study and implantation of a loop recorder were only performed in those with structural heart disease or traumatic syncope. Our work-up identified an etiology in 81% of the patients. Importantly, three quarters of the causes were established non invasively combining head-up tilt test, CSM and hyperventilation testing. Invasive tests yielded an additional 7% of diagnoses. Logistic analysis identified age and number of significant prodromes as the only predictive factors of rhythmic syncope. The same two factors, in addition to the duration of the ECG P-wave, were also predictive of vasovagal and psychogenic syncope. These factors, optimally combined in predictive models, showed a high negative and a modest positive predictive value. CONCLUSION: A standardized work-up focusing on non invasive tests allows to establish more than three quarters of syncope causes. Predictive models based on simple clinical parameters may help to distinguish between rhythmic and other causes of syncop
Four point function of R-currents in N=4 SYM in the Regge limit at weak coupling
We compute, in N=4 super Yang-Mills theory, the four point correlation
function of R-currents in the Regge limit in the leading logarithmic
approximation at weak coupling. Such a correlator is the closest analog to
photon-photon scattering within QCD, and there is a well-defined procedure to
perform the analogous computation at strong coupling via the AdS/CFT
correspondence. The main result of this paper is, on the gauge theory side, the
proof of Regge factorization and the explicit computation of the R-current
impact factors.Comment: 21 pages, 10 figures, typos correcte
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