The In-Hospital Mortality Rates of Slaves and Freemen: Evidence from Touro Infirmary, New Orleans, Louisiana, 1855–1860

Using a rich sample of admission records from New Orleans Touro Infirmary, we examine the in-hospital mortality risk of free and enslaved patients. Despite a higher mortality rate in the general population, slaves were significantly less likely to die in the hospital than the whites. We analyze the determinants of in-hospital mortality at Touro using Oaxaca-type decomposition to aggregate our regression results. After controlling for differences in characteristics and maladies, we find that much of the mortality gap remains unexplained. In conclusion, we propose an alternative explanation for the mortality gap based on the selective hospital admission of slaves.hospital, slavery, Oaxaca-type decomposition, New Orleans, Touro

Vortex Dynamics in Selfdual Maxwell-Higgs Systems with Uniform Background Electric Charge Density

We introduce selfdual Maxwell-Higgs systems with uniform background electric charge density and show that the selfdual equations satisfied by topological vortices can be reduced to the original Bogomol'nyi equations without any background. These vortices are shown to carry no spin but to feel the Magnus force due to the shielding charge carried by the Higgs field. We also study the dynamics of slowly moving vortices and show that the spin-statistics theorem holds to our vortices.Comment: 24 pages + 2 figures ( not included), Cu-TP-611, IASSNS-HEP-93/33, NSF-ITP-93-13

Thermal Properties of Two-Dimensional Advection Dominated Accretion Flow

We study the thermal structure of the widely adopted two-dimensional advection dominated accretion flow (ADAF) of Narayan & Yi (1995a). The critical radius for a given mass accretion rate, outside of which the optically thin hot solutions do not exist in the equatorial plane, agrees with one-dimensional study. However, we find that, even within the critical radius, there always exists a conical region of the flow, around the pole, which cannot maintain the assumed high electron temperature, regardless of the mass accretion rate, in the absence of radiative heating. This could lead to torus-like advection inflow shape since, in general, the ions too will cool down. We also find that Compton preheating is generally important and, if the radiative efficiency, defined as the luminosity output divided by the mass accretion rate times the velocity of light squared, is above sim 4x10^-3, the polar region of the flow is preheated above the virial temperature by Compton heating and it may result in time-dependent behaviour or outflow while accretion continues in the equatorial plane. Thus, under most relevant circumstances, ADAF solutions may be expected to be accompanied by polar outflow winds. While preheating instabilities exist in ADAF, as for spherical flows, the former are to some extent protected by their characteristically higher densities and higher cooling rates, which reduce their susceptibility to Compton driven overheating.Comment: 18 pages including 4 figures. AASTEX. Submitted to Ap

Chern-Simons Solitons, Chiral Model, and (affine) Toda Model on Noncommutative Space

We consider the Dunne-Jackiw-Pi-Trugenberger model of a U(N) Chern-Simons gauge theory coupled to a nonrelativistic complex adjoint matter on noncommutative space. Soliton configurations of this model are related the solutions of the chiral model on noncommutative plane. A generalized Uhlenbeck's uniton method for the chiral model on noncommutative space provides explicit Chern-Simons solitons. Fundamental solitons in the U(1) gauge theory are shaped as rings of charge `n' and spin `n' where the Chern-Simons level `n' should be an integer upon quantization. Toda and Liouville models are generalized to noncommutative plane and the solutions are provided by the uniton method. We also define affine Toda and sine-Gordon models on noncommutative plane. Finally the first order moduli space dynamics of Chern-Simons solitons is shown to be trivial.Comment: latex, JHEP style, 23 pages, no figur

Preheated Advection Dominated Accretion Flow

All high temperature accretion solutions including ADAF are physically thick, so outgoing radiation interacts with the incoming flow, sharing as much or more resemblance with classical spherical accretion flows as with disk flows. We examine this interaction for the popular ADAF case. We find that without allowance for Compton preheating, a very restricted domain of ADAF solution is permitted and with Compton preheating included a new high temperature PADAF branch appears in the solution space. In the absence of preheating, high temperature flows do not exist when the mass accretion rate mdot == Mdot c^2 / L_E >~ 10^-1.5. Below this mass accretion rate, a roughly conical region around the hole cannot sustain high temperature ions and electrons for all flows having mdot >~ 10^-4, which may lead to a funnel possibly filled with a tenuous hot outgoing wind. If the flow starts at large radii with the usual equilibrium temperature ~10^4 K, the critical mass accretion rate is much lower, mdot \~10^-3.7 above which level no self-consistent ADAF (without preheating) can exist. However, above this critical mass accretion rate, the flow can be self-consistently maintained at high temperature if Compton preheating is considered. These solutions constitute a new branch of solutions as in spherical accretion flows. High temperature PADAF flows can exist above the critical mass accretion rate in addition to the usual cold thin disk solutions. We also find solutions where the flow near the equatorial plane accretes normally while the flow near the pole is overheated by Compton preheating, possibly becoming, a polar wind, solutions which we designate WADAF.Comment: 41 pages with 10 postscript figures (aastex5). Submitted to Ap

Biophysical physiology of phosphoinositide rapid dynamics and regulation in living cells

Phosphoinositide membrane lipids are ubiquitous low-abundance signaling molecules. They direct many physiological processes that involve ion channels, membrane identification, fusion of membrane vesicles, and vesicular endocytosis. Pools of these lipids are continually broken down and refilled in living cells, and the rates of some of these reactions are strongly accelerated by physiological stimuli. Recent biophysical experiments described here measure and model the kinetics and regulation of these lipid signals in intact cells. Rapid on-line monitoring of phosphoinositide metabolism is made possible by optical tools and electrophysiology. The experiments reviewed here reveal that as for other cellular second messengers, the dynamic turnover and lifetimes of membrane phosphoinositides are measured in seconds, controlling and timing rapid physiological responses, and the signaling is under strong metabolic regulation. The underlying mechanisms of this metabolic regulation remain questions for the future

Experimental determination of the magnetic interactions of frustrated Cairo pentagon lattice materials

We present inelastic neutron scattering measurements of the Cairo pentagon lattice magnets Bi$_2$Fe$_4$O$_9$ and Bi$_4$Fe$_5$O$_{13}$F, supported by high field magnetisation measurements of Bi$_2$Fe$_4$O$_9$. Using linear spin wave theory and mean field analyses we determine the spin exchange interactions and single-ion anisotropy in these materials. The Cairo lattice is geometrically frustrated and consists of two inequivalent magnetic sites, both occupied by Fe$^{3+}$ ions and connected by two competing nearest neighbour interactions. We found that one of these interactions, coupling nearest neighbour spins on the three-fold symmetric sites, is extremely strong and antiferromagnetic. These strongly coupled dimers are then weakly coupled to a framework formed from spins occupying the other inequivalent site. In addition we found that the Fe$^{3+}$ $S=5/2$ spins have a non-negligible single-ion anisotropy, which manifests as a spin anisotropy gap in the neutron spectrum and a spin-flop transition in high field magnetisation measurements.Comment: 10 pages, 9 figure

BPS D0-D6 Branes in Supergravity

We analyse 1/2 BPS IIA Dp-brane supergravity solutions with $B$-fields and their Killing spinor equations. Via probe analysis, we rederive the supersymmetry conditions for D0-Dp with $B$-fields. In the case of D6 with $B$-fields, the D0-probe sees a multi-centred BPS configuration where the $B$-fields give the location of a wall of marginal stability. Finally we go beyond the probe approximation and construct a 1/8 BPS supergravity solution for a fully back-reacted D0-D6 with $B$-fields.Comment: 30 pages,1 figure, references added, typos fixe

Short- versus long-term dual antiplatelet therapy after drug-eluting stent implantation: An individual patient data pairwise and network meta-analysis

Background Randomized controlled trials comparing short- (≤6 months) with long-term (≥1 year) dual antiplatelet therapy (DAPT) after drug-eluting stent(s) (DES) placement have been insufficiently powered to detect significant differences in the risk of major adverse cardiac events (MACE). Objectives This study sought to compare clinical outcomes between short- (≤6 months) and long-term (1 year) DAPT and among 3 months, 6 months, and 1 year of DAPT post-DES placement by performing an individual patient data pairwise and network meta-analysis. Methods Randomized controlled trials comparing DAPT durations after DES placement were searched through the MEDLINE, EMBASE, and Cochrane databases and in international meeting proceedings. The primary study outcome was 1-year risk of MACE (cardiac death, myocardial infarction, or definite/probable stent thrombosis). Results Four trials including 8,180 randomized patients were identified. At 1-year follow-up, short-term DAPT was associated with similar rates of MACE (hazard ratio [HR]: 1.11; 95% confidence interval [CI]: 0.86 to 1.43; p = 0.44), but significantly lower rates of bleeding (HR: 0.66; 95% CI: 0.46 to 0.94; p = 0.03) versus prolonged DAPT. Comparable results were apparent in the landmark period between DAPT discontinuation and 1-year follow-up (for MACE: HR: 1.20; 95% CI: 0.77 to 1.89; p = 0.42) (for bleeding: HR: 0.44; 95% CI: 0.21 to 0.91; p = 0.03). There were no significant differences in 1-year rates of MACE among 3-month versus 1-year DAPT, 6-month versus 1-year DAPT, or 3-month versus 6-month DAPT. Conclusions Compared with prolonged DAPT, short-term DAPT is associated with similar rates of MACE but lower rates of bleeding after DES placement

Moxibustion for hypertension: a systematic review

<p>Abstract</p> <p>Background</p> <p>Moxibustion is a traditional East Asian medical therapy that uses the heat generated by burning herbal preparations containing <it>Artemisia vulgaris </it>to stimulate acupuncture points. The aim of this review was to evaluate previously published clinical evidence for the use of moxibustion as a treatment for hypertension.</p> <p>Methods</p> <p>We searched 15 databases without language restrictions from their respective dates of inception until March 2010. We included randomized controlled trials (RCTs) comparing moxibustion to either antihypertensive drugs or no treatment. The risk of bias was assessed for each RCT.</p> <p>Results</p> <p>During the course of our search, we identified 519 relevant articles. A total of 4 RCTs met all the inclusion criteria, two of which failed to report favorable effects of moxibustion on blood pressure (BP) compared to the control (antihypertensive drug treatment alone). However, a third RCT showed significant effects of moxibustion as an adjunct treatment to antihypertensive drug therapy for lowering BP compared to antihypertensive drug therapy alone. The fourth RCT included in this review addressed the immediate BP-lowering effects of moxibustion compared to no treatment. None of the included RCTs reported the sequence generation, allocation concealment and evaluator blinding.</p> <p>Conclusion</p> <p>There is insufficient evidence to suggest that moxibustion is an effective treatment for hypertension. Rigorously designed trials are warranted to answer the many remaining questions.</p