First Measurement Using Elliptically Polarized Photons of the Double-Polarization Observable E for γp→pπ^{0} and γp→nπ^{+}.

We report the measurement of the helicity asymmetry E for the pπ^{0} and nπ^{+} final states using, for the first time, an elliptically polarized photon beam in combination with a longitudinally polarized target at the Crystal Ball experiment at MAMI. The results agree very well with data that were taken with a circularly polarized photon beam, showing that it is possible to simultaneously measure polarization observables that require linearly (e.g.

Single production off neutrons bound in deuteron with linearly polarized photons.

The quasifree photon beam asymmetry, , has been measured at photon energies, , from 390 to 610 MeV, corresponding to center of mass energy from 1.271 to 1.424 GeV, for the first time.

Helicity-Dependent Cross Sections for the Photoproduction of π^{0} Pairs from Nucleons.

The double-polarization observable E and helicity-dependent cross sections σ_{1/2}, σ_{3/2} have been measured for the photoproduction of π^{0} pairs off quasifree protons and neutrons at the Mainz MAMI accelerator with the Crystal Ball/TAPS setup. A circularly polarized photon beam was produced by bremsstrahlung from longitudinally polarized electrons and impinged on a longitudinally polarized deuterated butanol target. The reaction products were detected with an almost 4π covering calorimeter.

Demographic and social context of deaths during the 1854 cholera outbreak in Soho, London: a reappraisal of Dr John Snow's investigation.

Deaths from cholera in Soho, London (late July to end of September 1854) exposed the epidemiology of the disease and demonstrated applied geospatial analysis by highlighting the shortest path principle followed by local residents when they obtained drinking water from a contaminated pump. The present investigation explores if households and individuals with different demographic and socio-economic characteristics were more or less likely to obtain their water from the pump and succumb to the disease. It combines information from the 1851 Population Census and topographic databases with the digital deaths and water pump data to reveal the risk of exposure and the mortality rate were greater for certain occupations, age groups and people living at high residential density irrespective of proximity to the contaminated water pump.