Israel in Adult Education

The relationship between American Jews and Israel has been impacted by the growing differences between the two communities. This research outlines the challenges of adult Jewish education today and provides recommendations on how to enhance the quality and frequency of Israel education in adult learning experiences

An Exceptional Sector for F-theory GUTs

D3-branes are often a necessary ingredient in global compactifications of F-theory. In minimal realizations of flavor hierarchies in F-theory GUT models, suitable fluxes are turned on, which in turn attract D3-branes to the Yukawa points. Of particular importance are ``E-type'' Yukawa points, as they are required to realize a large top quark mass. In this paper we study the worldvolume theory of a D3-brane probing such an E-point. D3-brane probes of isolated exceptional singularities lead to strongly coupled N = 2 CFTs of the type found by Minahan and Nemeschansky. We show that the local data of an E-point probe theory determines an N = 1 deformation of the original N = 2 theory which couples this strongly interacting CFT to a free hypermultiplet. Monodromy in the seven-brane configuration translates to a novel class of deformations of the CFT. We study how the probe theory couples to the Standard Model, determining the most relevant F-term couplings, the effect of the probe on the running of the Standard Model gauge couplings, as well as possible sources of kinetic mixing with the Standard Model.Comment: v2: 32 pages, 1 figure, references added, appendix remove

Variations in mid-ocean ridge CO2 emissions driven by glacial cycles

The geological record shows links between glacial cycles and volcanic productivity, both subaerially and at mid-ocean ridges. Sea-level-driven pressure changes could also affect chemical properties of mid-ocean ridge volcanism. We consider how changing sea-level could alter the CO2 emissions rate from mid-ocean ridges, on both the segment and global scale. We develop a simplified transport model for a highly incompatible element through a homogenous mantle; variations in the melt concentration the emission rate of the element are created by changes in the depth of first silicate melting. The model predicts an average global mid-ocean ridge CO2 emissions-rate of 53 Mt/yr, in line with other estimates. We show that falling sea level would cause an increase in ridge CO2 emissions with a lag of about 100 kyrs after the causative sea level change. The lag and amplitude of the response are sensitive to mantle permeability and plate spreading rate. For a reconstructed sea-level time series of the past million years, we predict variations of up to 12% (7 Mt/yr) in global mid-ocean ridge CO2 emissions. The magnitude and timing of the predicted variations in CO2 emissions suggests a potential role for ridge carbon emissions in glacial cycles

A Renaissance Instrument to Support Nonprofits: The Sale of Private Chapels in Florentine Churches

Catholic churches in Renaissance Florence supported themselves overwhelmingly from the contributions of wealthy citizens. The sale of private chapels within churches to individuals was a significant source of church funds, and facilitated a church construction boom. Chapel sales offered three benefits to churches: prices were usually far above cost; donor/purchasers purchased masses and other tie-in services; and they added to the magnificence of the church because donors were required to decorate chapels expensively. Donors purchased chapels for two primary reasons: to facilitate services for themselves and their families, such as masses and church burials, that would speed their departure from Purgatory; and to gain status in the community. Chapels were private property within churches, but were only occasionally used directly by their owners. The expense of chapels and their decorations made them an ideal signal for wealth, particularly since sumptuary laws limited most displays of wealth. To overcome the contributions free-rider problem, these churches sold private benefits not readily available elsewhere, namely status and salvation.