York\u27s Roots and wings (Book Review)

A review of York, S. (2016). Roots and wings. St. Paul, MN: Redleaf Press. 334 pp. $44.95. ISBN 978160554455

Social Protection Index Brief: Social Assistance Programs in Asia and the Pacific

[Excerpt] The Asian Development Bank (ADB) report The Social Protection Index: Assessing Results for Asia and the Pacific (2013) documents the role of social assistance in social protection systems across the region. This brief examines the six major subcomponents of social assistance and draws out policy lessons based on comprehensive data for 35 countries in the region. The report uses the Social Protection Index (SPI) as the focal point for its analysis. The SPI is the ratio of total social protection expenditures to the total number of intended beneficiaries. These “expenditures per potential beneficiary” are then compared to a regional poverty line as a reference point (ADB 2012c)

Social Protection Index Brief: Labor Market Programs in Asia and the Pacific

[Excerpt] The Asian Development Bank (ADB) report The Social Protection Index: Assessing Results for Asia and the Pacific (2013) documents the negligible role of labor market programs in social protection programs across the region

Damping of Electron Density Structures and Implications for Interstellar Scintillation

The forms of electron density structures in kinetic Alfven wave turbulence are studied in connection with scintillation. The focus is on small scales $L \sim 10^8-10^{10}$ cm where the Kinetic Alfv\'en wave (KAW) regime is active in the interstellar medium. MHD turbulence converts to a KAW cascade, starting at 10 times the ion gyroradius and continuing to smaller scales. These scales are inferred to dominate scintillation in the theory of Boldyrev et al. From numerical solutions of a decaying kinetic Alfv\'en wave turbulence model, structure morphology reveals two types of localized structures, filaments and sheets, and shows that they arise in different regimes of resistive and diffusive damping. Minimal resistive damping yields localized current filaments that form out of Gaussian-distributed initial conditions. When resistive damping is large relative to diffusive damping, sheet-like structures form. In the filamentary regime, each filament is associated with a non-localized magnetic and density structure, circularly symmetric in cross section. Density and magnetic fields have Gaussian statistics (as inferred from Gaussian-valued kurtosis) while density gradients are strongly non-Gaussian, more so than current. This enhancement of non-Gaussian statistics in a derivative field is expected since gradient operations enhance small-scale fluctuations. The enhancement of density gradient kurtosis over current kurtosis is not obvious, yet it suggests that modest fluctuation levels in electron density may yield large scintillation events during pulsar signal propagation in the interstellar medium. In the sheet regime the same statistical observations hold, despite the absence of localized filamentary structures. Probability density functions are constructed from statistical ensembles in both regimes, showing clear formation of long, highly non-Gaussian tails

Almost Commuting Orthogonal Matrices

We show that almost commuting real orthogonal matrices are uniformly close to exactly commuting real orthogonal matrices. We prove the same for symplectic unitary matrices. This is in contrast to the general complex case, where not all pairs of almost commuting unitaries are close to commuting pairs. Our techniques also yield results about almost normal matrices over the reals and the quaternions.Comment: 13 pages, 3 figure