The π0→e+e−\pi^0\to e^+e^- and η→μ+μ−\eta\to \mu^+ \mu^- Decays Revisited

The rare $\pi^0 \to e^+e^-$ and $\eta \to \mu^+\mu^-$ decays are calculated in different schemes, which are seen to be essentially equivalent to and produce the same results as conventional Vector-Meson Dominance. We obtain the theoretical predictions $B(\pi^0 \to e^+e^-) = (6.41 \pm 0.19)\times 10^{-8}$ and $B(\eta \to \mu^+\mu^-) = (1.14 +0.06 -0.03) \times 10^{-5}$ in agreement with recent experimental data.Comment: 10 pages, LATEX (revised version for recent experimental data

Para-infectious brain injury in COVID-19 persists at follow-up despite attenuated cytokine and autoantibody responses

To understand neurological complications of COVID-19 better both acutely and for recovery, we measured markers of brain injury, inflammatory mediators, and autoantibodies in 203 hospitalised participants; 111 with acute sera (1–11 days post-admission) and 92 convalescent sera (56 with COVID-19-associated neurological diagnoses). Here we show that compared to 60 uninfected controls, tTau, GFAP, NfL, and UCH-L1 are increased with COVID-19 infection at acute timepoints and NfL and GFAP are significantly higher in participants with neurological complications. Inflammatory mediators (IL-6, IL-12p40, HGF, M-CSF, CCL2, and IL-1RA) are associated with both altered consciousness and markers of brain injury. Autoantibodies are more common in COVID-19 than controls and some (including against MYL7, UCH-L1, and GRIN3B) are more frequent with altered consciousness. Additionally, convalescent participants with neurological complications show elevated GFAP and NfL, unrelated to attenuated systemic inflammatory mediators and to autoantibody responses. Overall, neurological complications of COVID-19 are associated with evidence of neuroglial injury in both acute and late disease and these correlate with dysregulated innate and adaptive immune responses acutely

Walks with ghosts

The supersymmetric formulation of the self-suppressing random walk is examined. By defining the theory as a lattice model it is shown that the supersymmetry remains unbroken throughout the physical parameter space, contrary to claims in the literature.Articl

Supermassive neutrino stars and galactic nuclei

The characteristics of supermassive 'stars' consisting of self-gravitating degenerate neutrino (or neutralino) matter are studied with particular emphasis on fermion masses around 17 keV/c2. Such compact dark objects could be as massive as 109.5 to 106.5 solar masses, with radii of about one to ten light days; they might thus mimic phenomena that are expected around the supermassive black holes recently purported at the centres of some galaxies and quasi-stellar objects.Articl

Assessing Instrument Mixes through Program- and Agency-Level Data: Methodological Issues in Contemporary Implementation Research

Theories of policy instrument choice have gone through several "generations" as theorists have moved from the analysis of individual instruments to comparative studies of instrument selection and the development of theories of instrument choice within implementation "mixes" or "governance strategies." Current "next generation" theory on policy instruments centers on the question of the optimality of instrument choices. However, empirically assessing the nature of instrument mixes is quite a complex affair, involving considerable methodological difficulties and conceptual ambiguities related to the definition and measurement of policy sector and instruments and their interrelationships. Using materials generated by Canadian governments, this article examines the practical utility and drawbacks of three techniques used in the literature to inventory instruments and identify instrument ecologies and mixes: the conventional "policy domain" approach suggested by Burstein (1991); the "program" approach developed by Rose (1988a); and the "legislative" approach used by Hosseus and Pal (1997). This article suggests that all three approaches must be used in order to develop even a modest inventory of policy instruments, but that additional problems exist with availability and accessibility of data, both in general and in terms of reconciling materials developed using these different approaches, which makes the analysis of instrument mixes a time-consuming and expensive affair. Copyright 2006 by The Policy Studies Organization.