Regge's Einstein-Hilbert Functional on the Double Tetrahedron

The double tetrahedron is the triangulation of the three-sphere gotten by gluing together two congruent tetrahedra along their boundaries. As a piecewise flat manifold, its geometry is determined by its six edge lengths, giving a notion of a metric on the double tetrahedron. We study notions of Einstein metrics, constant scalar curvature metrics, and the Yamabe problem on the double tetrahedron, with some reference to the possibilities on a general piecewise flat manifold. The main tool is analysis of Regge's Einstein-Hilbert functional, a piecewise flat analogue of the Einstein-Hilbert (or total scalar curvature) functional on Riemannian manifolds. We study the Einstein-Hilbert-Regge functional on the space of metrics and on discrete conformal classes of metrics

Antipodean fugitive terranes in southern Laurentia: How Proterozoic Australia built the American West

Paleoproterozoic arc and backarc assemblages accreted to the south Laurentian margin between 1800 Ma and 1600 Ma, and previously thought to be indigenous to North America, more likely represent fragments of a dismembered marginal sea developed outboard of the formerly opposing Australian-Antarctic plate. Fugitive elements of this arc-backarc system in North America share a common geological record with their left-behind Australia-Antarctic counterparts, including discrete peaks in tectonic and/or magmatic activity at 1780 Ma, 1760 Ma, 1740 Ma, 1710–1705 Ma, 1690–1670 Ma, 1650 Ma, and 1620 Ma. Subduction rollback, ocean basin closure, and the arrival of Laurentia at the Australian-Antarctic convergent margin first led to arc-continent collision at 1650–1640 Ma and then continent-continent collision by 1620 Ma as the last vestiges of the backarc basin collapsed. Collision induced obduction and transfer of the arc and more outboard parts of the Australian-Antarctic backarc basin onto the Laurentian margin, where they remained following later breakup of the Neoproterozoic Rodinia supercontinent. North American felsic rocks generally yield Nd depleted mantle model ages consistent with arc and backarc assemblages built on early Paleoproterozoic Australian crust as opposed to older Archean basement making up the now underlying Wyoming and Superior cratons

Prosecutorial Discretion and the Death Penalty: An Integral Perspective

The prosecutor's choice to pursue the death penalty is one of the most momentous decisions he or she will face. Capital punishment represents the ultimate power of the state over its citizenry, and the decision to take the life of an offender is fraught with moral complexity. This paper reviews some of the extant literature on the US death penalty in general and the particular issue of decision-making for prosecutors. Further, we introduce discussion on how Wilber's Integral theory might be applied to the topic. We present aspects of Integral theory, including the four quadrant model and what Wilber refers to as the Basic Moral Intuition (BMI), as possible tools that may be used to navigate the ethical difficulties surrounding this decision-making process. We anticipate that delving into aspects of the Integral theory and contemplating on how they relate to concrete issues of criminal prosecution may assist CJ practitioners in how they might find pathways to resolutions of ethical quandaries

Juvenile Probationers, Restitution Payments, and Empathy: An Evaluation of a Restorative Justice Based Program in Northeastern Pennsylvania

Restitution programs are widely used to hold offenders accountable for their actions while providing restoration to victims and community service. However, compliance with restitution requirements is a major problem, as reported by juvenile probation offices across the country. The Firewood Program was developed for juvenile probationers in a rural Pennsylvania county to improve the completion rate of restitution payments to victims and provide community service. This study examines the effectiveness of the restitution program, which was measured as an increase in the offender's level of empathy and shorter completion times of restitution payments.

Migration and longer distance commuting in rural England

This paper examines whether recent in-migrants to rural settlements in England commute further to work than the longer-term residents of these places and whether commuting distance differs according to the type of move and the geographical context of their home. The study is based on data from the Controlled Access Microdata Sample (CAMS) of the 2001 Census of Population. It is found that recent in-migrants are much more likely to commute at least 20km than are the longer-term residents. Using binary logistic regression so as to allow for socio-demographic differences between people, it is shown that the likelihood of longer distance commuting was highest for people who had moved home by between 15 and 99km and for people moving from the largest cities

Sexual Selection: Signals to Die for

SummarySexual signals are conspicuous and are typically assumed to be energetically costly, which keeps them honest. A recent study on fireflies has found that signal production is energetically cheap, but signalling remains expensive because of eavesdropping predators

Biomimetic apatite sintered at very low temperature by spark plasma sintering: Physico-chemistry and microstructure aspects

Nanocrystalline apatites analogous to bone mineral are very promising materials for the preparation of highly bioactive ceramics due to their unique intrinsic physico-chemical characteristics. Their surface reactivity is indeed linked to the presence of a metastable hydrated layer on the surface of the nanocrystals. Yet the sintering of such apatites by conventional techniques, at high temperature, strongly alters their physico-chemical characteristics and biological properties, which points out the need for "softer" sintering processes limiting such alterations. In the present work a non-conventional technique, spark plasma sintering, was used to consolidate such nanocrystalline apatites at non-conventional, very low temperatures (T° < 300 °C) so as to preserve the surface hydrated layer present on the nanocrystals. The bioceramics obtained were then thoroughly characterized by way of complementary techniques. In particular, microstructural, nanostructural and other major physico-chemical features were investigated and commented on. This work adds to the current international concern aiming at improving the capacities of present bioceramics, in view of elaborating a new generation of resorbable and highly bioactive ceramics for bone tissue engineering

Atmospheric rivers do not explain UK summer extreme rainfall

Extreme rainfall events continue to be one of the largest natural hazards in the UK. In winter, heavy precipitation and floods have been linked with intense moisture transport events associated with atmospheric rivers (ARs), yet no large-scale atmospheric precursors have been linked to summer flooding in the UK. This study investigates the link between ARs and extreme rainfall from two perspectives: 1) Given an extreme rainfall event, is there an associated AR? 2) Given an AR, is there an associated extreme rainfall event? We identify extreme rainfall events using the UK Met Office daily rain-gauge dataset and link these to ARs using two different horizontal resolution atmospheric datasets (ERA-Interim and 20th Century Re-analysis). The results show that less than 35% of winter ARs and less than 15% of summer ARs are associated with an extreme rainfall event. Consistent with previous studies, at least 50% of extreme winter rainfall events are associated with an AR. However, less than 20% of the identified summer extreme rainfall events are associated with an AR. The dependence of the water vapor transport intensity threshold used to define an AR on the years included in the study, and on the length of the season, is also examined. Including a longer period (1900-2012) compared to previous studies (1979-2005) reduces the water vapor transport intensity threshold used to define an AR

Reclaiming Vacant Houses & Preventing Foreclosure: Lessons from LISCs New York State Vacants Initiative

The housing instability caused by COVID has continued into 2022, even as foreclosure moratoria end at federal and state levels around the country. This report, Reclaiming Vacant Houses & Preventing Foreclosure: Lessons from LISC's New York State Vacants Initiative, a collaboration of LISC and the Urban Institute, provides lessons and evidence of outcomes of a path-breaking law and LISC initiative in reducing vacant houses and preventing foreclosures in jurisdictions across New York State