22,275 research outputs found
Phase diagram of random lattice gases in the annealed limit
An analysis of the random lattice gas in the annealed limit is presented. The
statistical mechanics of disordered lattice systems is briefly reviewed. For
the case of the lattice gas with an arbitrary uniform interaction potential and
random short-range interactions the annealed limit is discussed in detail. By
identifying and extracting an entropy of mixing term, a correct physical
expression for the pressure is explicitly given. As an application, the
one-dimensional lattice gas with uniform long-range interactions and random
short-range interactions satisfying a bimodal annealed probability distribution
is discussed. The model is exactly solved and is shown to present interesting
behavior in the presence of competition between interactions, such as the
presence of three phase transitions at constant temperature and the occurrence
of triple and quadruple points.Comment: Final version to be published in the Journal of Chemical Physic
Bootstrapping QCD: the Lake, the Peninsula and the Kink
We consider the S-matrix bootstrap of four dimensional scattering amplitudes
with symmetry and no bound-states. We explore the allowed space of
scattering lengths which parametrize the interaction strength at threshold of
the various scattering channels. Next we consider an application of this
formalism to pion physics. A signature of pions is that they are derivatively
coupled leading to (chiral) zeros in their scattering amplitudes. In this work
we explore the multi-dimensional space of chiral zeros positions, scattering
length values and resonance mass values. Interestingly, we encounter lakes,
peninsulas and kinks depending on which sections of this intricate
multi-dimensional space we consider. We discuss the remarkable location where
QCD seems to lie in these plots, based on various experimental and theoretical
expectations.Comment: 6 pages, 7 figure
BP Reduction, Kidney Function Decline, and Cardiovascular Events in Patients without CKD.
BACKGROUND AND OBJECTIVES:
In the Systolic Blood Pressure Intervention Trial (SPRINT), intensive systolic BP treatment (target <120 mm Hg) was associated with fewer cardiovascular events and higher incidence of kidney function decline compared with standard treatment (target <140 mm Hg). We evaluated the association between mean arterial pressure reduction, kidney function decline, and cardiovascular events in patients without CKD.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS:
We categorized patients in the intensive treatment group of the SPRINT according to mean arterial pressure reduction throughout follow-up: <20, 20 to <40, and ≥40 mm Hg. We defined the primary outcome as kidney function decline (≥30% reduction in eGFR to <60 ml/min per 1.73 m2 on two consecutive determinations at 3-month intervals), and we defined the secondary outcome as cardiovascular events. In a propensity score analysis, patients in each mean arterial pressure reduction category from the intensive treatment group were matched with patients from the standard treatment group to calculate the number needed to treat regarding cardiovascular events and the number needed to harm regarding kidney function decline.
RESULTS:
In the intensive treatment group, 1138 (34%) patients attained mean arterial pressure reduction <20 mm Hg, 1857 (56%) attained 20 to <40 mm Hg, and 309 (9%) attained ≥40 mm Hg. Adjusted hazard ratios for kidney function decline were 2.10 (95% confidence interval, 1.22 to 3.59) for mean arterial pressure reduction between 20 and 40 mm Hg and 6.22 (95% confidence interval, 2.75 to 14.08) for mean arterial pressure reduction ≥40 mm Hg. In propensity score analysis, mean arterial pressure reduction <20 mm Hg presented a number needed to treat of 44 and a number needed to harm of 65, reduction between 20 and <40 mm Hg presented a number needed to treat of 42 and a number needed to harm of 35, and reduction ≥40 mm Hg presented a number needed to treat of 95 and a number needed to harm of 16.
CONCLUSIONS:
In the intensive treatment group of SPRINT, larger declines in mean arterial pressure were associated with higher incidence of kidney function decline. Intensive treatment seemed to be less favorable when a larger reduction in mean arterial pressure was needed to attain the BP target.info:eu-repo/semantics/publishedVersio
Information entropy of classical versus explosive percolation
We study the Shannon entropy of the cluster size distribution in classical as
well as explosive percolation, in order to estimate the uncertainty in the
sizes of randomly chosen clusters. At the critical point the cluster size
distribution is a power-law, i.e. there are clusters of all sizes, so one
expects the information entropy to attain a maximum. As expected, our results
show that the entropy attains a maximum at this point for classical
percolation. Surprisingly, for explosive percolation the maximum entropy does
not match the critical point. Moreover, we show that it is possible determine
the critical point without using the conventional order parameter, just
analysing the entropy's derivatives.Comment: 6 pages, 6 figure
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