Classical Signature Change in the Black Hole Topology

Investigations of classical signature change have generally envisaged applications to cosmological models, usually a Friedmann-Lemaitre-Robertson-Walker model. The purpose has been to avoid the inevitable singularity of models with purely Lorentzian signature, replacing the neighbourhood of the big bang with an initial, singularity free region of Euclidean signture, and a signature change. We here show that signature change can also avoid the singularity of gravitational collapse. We investigate the process of re-birth of Schwarzschild type black holes, modelling it as a double signature change, joining two universes of Lorentzian signature through a Euclidean region which provides a `bounce'. We show that this process is viable both with and without matter present, but realistic models -- which have the signature change surfaces hidden inside the horizons -- require non-zero density. In fact the most realistic models are those that start as a finite cloud of collapsing matter, surrounded by vacuum. We consider how geodesics may be matched across a signature change surface, and conclude that the particle `masses' must jump in value. This scenario may be relevant to Smolin's recent proposal that a form of natural selection operates on the level of universes, which favours the type of universe we live in.Comment: LaTeX, 19 pages, 11 Figures. Replacement - only change is following comment: For a pdf version with the figures embedded, see http://www.mth.uct.ac.za/~cwh/mypub.htm

Making services work : indicators, assessments, and benchmarking of the quality and governance of public service delivery in the human development sectors

Improving governance is central to improving results in human development. It is clear that money is not enough: improved outcomes from service delivery require better governance, including mechanisms for holding service providers accountable and appropriate incentives for performance. There is therefore a growing demand for indicators to measure how and whether these processes work, and how they affect health and education results. This paper makes the case for measuring governance policies and performance, and the quality of service delivery in health and education. It develops a framework for selecting and measuring a set of indicators and proposes options, drawing from new and innovative measurement tools and approaches. The paper proposes the adoption of a more systematic approach that will both facilitate the work of health and education policymakers and allow for cross-country comparisons and benchmarking.Health Monitoring&Evaluation,Governance Indicators,Public Sector Corruption&Anticorruption Measures,Poverty Monitoring&Analysis,Public Sector Expenditure Policy

Agriculture and the clean development mechanism

Many experts believe that low-cost mitigation opportunities in agriculture are abundant and comparable in scale to those found in the energy sector. They are mostly located in developing countries and have to do with how land is used. By investing in projects under the Clean Development Mechanism (CDM), countries can tap these opportunities to meet their own Kyoto Protocol obligations. The CDM has been successful in financing some types of agricultural projects, including projects that capture methane or use agricultural by-products as an energy source. But agricultural land-use projects are scarce under the CDM. This represents a missed opportunity to promote sustainable rural development since land-use projects that sequester carbon in soils can help reverse declining soil fertility, a root cause of stagnant agricultural productivity. This paper reviews the process leading to current CDM implementation rules and describes how the rules, in combination with challenging features of land-use projects, raise transaction costs and lower demand for land-use credits. Procedures by which developed countries assess their own mitigation performance are discussed as a way of redressing current constraints on CDM investments. Nevertheless, even with improvements to the CDM, an under-investment in agricultural land-use projects is likely, since there are hurdles to capturing associated ancillary benefits privately. Alternative approaches outside the CDM are discussed, including those that build on recent decisions taken by governments in Copenhagen and Cancun.Climate Change Mitigation and Green House Gases,Environmental Economics&Policies,Energy and Environment,Environment and Energy Efficiency,Banks&Banking Reform

All My Heroes Are Broke

ALL MY HEROES ARE BROKE is a poetry collection written from the perspective of a first generation American coming to terms with the implicit struggles and disillusionment of the American Dream. The first section takes place in New York, both implicitly and explicitly, and serves to introduce the speaker and reveal aspects of his family’s history. The second section takes place in Florida, and continues to further exemplify the speaker’s growing cynicism towards the circumstances of his life, and the peculiar atmosphere of solitude that it creates. ALL MY HEROES ARE BROKE primarily uses two forms: short, image driven poems inspired by the works of Robert Bly and Po Chu-I; and longer narrative poems that reveal more personal information about the speaker, in the manner of Li-Young Lee and Frank O’Hara, allowing the speaker to project his own life onto his surroundings and the people of those larger communities

Pulse and Orbital Periods of ASAS182612

Physicists S.V. Antipin, K.V. Sokolovsky, and T.I. Ignatieva began observations of the variable star ASAS182612 in 2005, and found it to be the first known eclipsing binary with a type II Cepheid component in our galaxy. A month after Antipin’s publication, the American Association of Variable Star Observers (AAVSO) sent out an alert to campaign for observations of ASAS182612. From July 2007 to November 2015, 147 nights of multi-filter photometric data have been collected for ASAS182162. The pulsation period found was 4.1591 ± 0.0001 days and the orbital period 51.352 ± 0.016 days

The logic of aid: American foreign policy and USAID in Rwanda

Since the end of World War II, development aid has become a permanent fixture of U.S. foreign policy. The United States Agency for International Development (USAID) has been the primary organization for implementing the American government’s development policies. Because of this, USAID provides an excellent lens for viewing the historical trajectory of American development aid. USAID’s experience in Rwanda demonstrates the broad policy shifts that define this historical trajectory. During the 1960s, modernization theory directed development projects. In the 1970s this shifted to a needs-based mandate, and during the 1980s market liberalization programs defined USAID’s objectives. The rich relationship between USAID and Rwanda exemplifies the gap existing in development aid between ideology and practicality. Development aid’s value in determining foreign policy has also been underappreciated by scholars, and the comprehensive review of USAID projects provided aims to contribute to resolving these shortcomings

Ecomorphological Variation in Three Species of Cybotoid Anoles

© 2018 by The Herpetologists' League, Inc. Caribbean Anolis lizards exhibit a complex suite of ecological, morphological, and behavioral traits that allow their specialization to particular microhabitats. These microhabitat specialists, called ecomorphs, have independently evolved on the four islands of the Greater Antilles, and diversification among anole ecomorphs has been the focus of many studies. Yet, habitat specialization has also occurred among species within the same ecomorph group. Here, we examined ecological, morphological, and behavioral divergence in three Hispaniolan trunk-ground species, the cybotoid anoles: Anolis cybotes, A. marcanoi, and A. longitibialis. We found differences in limb morphology, locomotor behavior, and perch use among the three cybotoid species that mirror differences across the ecomorphs. Among these species of cybotoids, those that have longer limbs tend to move less frequently, occupy broader perches, and have smaller fourth toes with fewer lamellae. We also observed that the species with greater male-biased size dimorphism had larger heads, smaller dewlaps, and smaller testes. These results are consistent with the predictions of sexual selection theory, in that species with large male body size may have larger heads because of increased male-male combat, and smaller testes potentially attributable to a trade-off between pre- and postcopulatory selection. Overall, our study suggests that a combination of local adaptation to different structural habitats and sexual selection might produce ecomorphological diversification within cybotoid anoles of the same ecomorph group

1020 steel coated with Ti/TiN by Cathodic Arc and Ion Implantation

TiN coatings have been widely studied in order to improve mechanical properties of steels. In this work, thin Ti/TiN films were prepared by plasma based immersion ion implantation and deposition (PBII&D) with a cathodic arc on AISI 1020 steel substrates. Substrates were exposed to the discharge during 1 min in vacuum for the deposition of a Tiunderlayer with the aim of improving the adhesion to the substrate. Then, a TiN layer was deposited during 6 min in a nitrogen environment at a pressure of 3xl0-4 mbar. Samples were obtained at room temperature and at 300 °C, and with or without ion implantation in order to analyze differences between the effects of each treatment on the tribological properties. The mechanical and tribological properties of the films were characterized. The coatings deposited by PBII&D at 300 °C presented the highest hardness and young modulus, the best wear resistance and corrosion performance.Fil: Bermeo, Diego Fernando. Universidad Santiago de Cali; ColombiaFil: Quintana, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física del Plasma. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física del Plasma; ArgentinaFil: Kleiman, Ariel Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física del Plasma. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física del Plasma; ArgentinaFil: Sequeda, F.. Universidad del Valle; ColombiaFil: Márquez, A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física del Plasma. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física del Plasma; Argentin