Complexity of equivalence relations and preorders from computability theory

We study the relative complexity of equivalence relations and preorders from computability theory and complexity theory. Given binary relations $R, S$, a componentwise reducibility is defined by R\le S \iff \ex f \, \forall x, y \, [xRy \lra f(x) Sf(y)]. Here $f$ is taken from a suitable class of effective functions. For us the relations will be on natural numbers, and $f$ must be computable. We show that there is a $\Pi_1$-complete equivalence relation, but no $\Pi k$-complete for $k \ge 2$. We show that $\Sigma k$ preorders arising naturally in the above-mentioned areas are $\Sigma k$-complete. This includes polynomial time $m$-reducibility on exponential time sets, which is $\Sigma 2$, almost inclusion on r.e.\ sets, which is $\Sigma 3$, and Turing reducibility on r.e.\ sets, which is $\Sigma 4$.Comment: To appear in J. Symb. Logi

Correlation of Puma airloads: Evaluation of CFD prediction methods

A cooperative program was undertaken by research organizations in England, France, Australia and the U.S. to study the capabilities of computational fluid dynamics codes (CFD) to predict the aerodynamic loading on helicopter rotor blades. The program goal is to compare predictions with experimental data for flight tests of a research Puma helicopter with rectangular and swept tip blades. Two topics are studied. First, computed results from three CFD codes are compared for flight test cases where all three codes use the same partial inflow-angle boundary conditions. Second, one of the CFD codes (FPR) is iteratively coupled with the CAMRAD/JA helicopter performance code. These results are compared with experimental data and with an uncoupled CAMRAD/JA solution. The influence of flow field unsteadiness is found to play an important role in the blade aerodynamics. Alternate boundary conditions are suggested in order to properly model this unsteadiness in the CFD codes

The global epidemic of abuse and disrespect during childbirth: History, evidence, interventions, and FIGO’s mother−baby friendly birthing facilities initiative

AbstractRecent evidence indicates that disrespectful/abusive/coercive service delivery by skilled providers in facilities, which results in actual or perceived poor quality of care, is directly and indirectly associated with adverse maternal and newborn outcomes. The present article reviews the evidence for disrespectful/abusive care during childbirth in facilities (DACF), describes examples of DACF, discusses organizations active in a rights-based respectful maternity care movement, and enumerates some strategies and interventions that have been identified to decrease DACF. It concludes with a discussion of one strategy, which has been recently implemented by FIGO with global partners—the International Pediatrics Association, International Confederation of Midwives, the White Ribbon Alliance, and WHO. This strategy, the Mother and Baby Friendly Birth Facility (MBFBF) Initiative, is a criterion-based audit process based on human rights’ doctrines, and modeled on WHO/UNICEF’s Baby Friendly Facility Initiative

Thermally isolated deployable shield for spacecraft

A thermally isolated deployable shield for spacecraft is provided utilizing a plurality of lattice panels stowable generally against the craft and deployable to some fixed distance from the craft. The lattice panels are formed from replaceable shield panels affixed to lattice structures. The lattice panels generally encircle the craft providing 360 degree coverage therearound. Actuation means are provided from translating the shield radially outward from the craft and thermally isolating the shield from the craft. The lattice panels are relatively flexible, allowing the shield to deploy to variable diameters while retaining uniform curvature thereof. Restraining means are provided for holding the shield relatively tight in its stowed configuration. Close-out assemblies provide light sealing and protection of the annular spaces between the deployed shield and the crafts end structure

Electromagnetic Self-Energy Contribution to M-p-M-n and the Isovector Nucleon Magnetic Polarizability

We update the determination of the isovector nucleon electromagnetic self-energy, valid to leading order in QED. A technical oversight in the literature concerning the elastic contribution to Cottingham\u27s formula is corrected, and modern knowledge of the structure functions is used to precisely determine the inelastic contribution. We find delta M-p-n(gamma) = 1.30(03)(47) MeV. The largest uncertainty arises from a subtraction term required in the dispersive analysis, which can be related to the isovector magnetic polarizability. With plausible model assumptions, we can combine our calculation with additional input from lattice QCD to constrain this polarizability as: beta(p-n) = -0.87(85) x 10(-4) fm(3)