Liouville Models of Black Hole Evaporation

We construct new theories of dilation gravity coupled to conformal matter which are exact $c=26$ conformal field theories and presumably consistent frameworks for discussing black hole physics in two dimensions. They differ from the CGHS equations in the precise dilaton dependence of the cosmological constant. A further modification proposed by Strominger with a view to eliminating unphysical ghost Hawking radiation is also considered. The new classical equations of motion are explicitly soluble, thus permitting an exact analysis of both static and dynamic senarios. While the static solutions are physically reasonable, the dynamical solutions include puzzling examples with wrong-sign Hawking radiation. We indicate how the latter problem may be resolved in the full quantum theory.Comment: 27 pages, revised ("Note Added" is expanded to show how careful treatment of quantum effects makes the Hawking radiation rate proportional to N/12 rather than (N-24)/12 and also to show that the cosmic censorship mechanism proposed by Russo et.al. for a somewhat different model works for our model as well. New references are added and the preprint number is corrected.) PUPT-132

Is Inverse Demand Perverse?

Our non-representative sample of 245 undergraduates had significantly lower scores on questions presented in the standard heterogeneous form (i.e., Direct Demand equation and Inverse Demand graph) than on questions presented in non-standard homogenous forms. This result, which holds for advanced students, highlights one reason why 95 percent of students in economics principles classes do not enter the major---economics can be gratuitously mathematical. We argue that the Inverse Demand standard hurts rather than helps economics when it is used in early courses, but that professors have no incentive to change their methods. We recommend that early classes use either no graphs or a homogenous combination of graph and equation. The standard should be introduced later, when benefits outweigh costs.Demand and Price Analysis,

THE YEAR 2000: A FOOD INDUSTRY FORECAST

Agribusiness,

The scale insects (Hemiptera: Coccoidea) of the Maltese Archipelago

Past works on scale insects (Hemiptera: Coccoidea) from the Maltese Archipelago are reviewed. Based on the literature and contemporary collections, a total of 93 species of scale insects belonging to 12 scale insect families are here reported (Aclerdidae 1 species; Asterolecaniidae 4; Coccidae 17; Diaspididae 46; Eriococcidae 5; Kermesidae 1; Margarodidae 1; Micrococcidae 1; Monophlebidae 2; Pseudoccocidae 11; Putoidae 2 and Rhizoecidae 2). Of these, 17 species represent new distribution records. Ten species are excluded from the scale insect fauna of the Maltese Islands. Of the 93 species present, only 29 (31.18%) are probably indigenous and the rest (68.82%) represent established introductions from elsewhere. More than 65% of the indigenous species are typical Mediterranean in distribution, with a few species having a mainly European chorotype. A quarter of the established aliens originate from Eurasia, followed by an East Asian/ Oriental component (20.31%); European (14.06%); Neotropical (14.06%); cryptogenic (14.06%); African (7.81%) and Australasian (4.70%). Movement of live fruit trees and ornamental plants into the Maltese Archipelago from nearby countries is probably the main route for entry of alien scale insects into the country. Some possible future introductions are discussed.peer-reviewe

Black Hole Physics from Liouville Theory

In a previous paper it was shown that the quantum consistency conditions for the dilaton-gravity theory of Callan et al., imply that the cosmological constant term undergoes a dilaton dependent renormalization, in such a manner that the theory can be written as a Liouville-like theory. In this paper we discuss the physical interpretation of the solutions of this theory. In particular we demonstrate explicitly how quantum corrections tame the black hole singularity. Also under the assumption that in asymptotically Minkowski coordinates, there are no incoming or outgoing ghosts, we show that the Hawking radiation rate is independent of the number of matter fields and is determined by the ghost conformal anomaly.Comment: 15 pages, phyzzx (Note on Bondi mass added to end of paper

THE NECESSITY OF DEVELOPING RESPONSIBLE USE POLICIES: ADVOCACY FOR USE OF WEB 2.0 TOOLS IN A COMPREHENSIVE SCHOOL COMPUTING PROGRAM

Technology is omnipresent in our modern age: anyone with an Internet connection can use a computer, tablet, or phone to access an unfathomable amount of information. Today, teenagers use e-mail, texting, and social media to stay in nearly constant communication with friends and family anywhere in the world. With so much time spent exchanging ideas in cyberspace, there is an increased likelihood of teachers and students regularly crossing paths electronically for both legitimate academic purposes and social contexts. Without sufficient school district policies to guide these interactions, students and teachers could realistically place themselves in awkward situations and face district sanctions due to inappropriate behavior. The purpose of this project is to develop an Acceptable Use Policy (AUP) governing student and teacher computer use that must be reviewed and signed by parents, students, and teachers at the start of every school year. The policy advocacy focuses on inclusion of social media and other Web 2.0 tools as legitimate applications for the classroom. Research provides valuable information regarding responsible ways to utilize Web 2.0 tools to enhance teaching and learning and incorporate them into a school’s repertoire of instructional methodologies. These technologies tap into students’ inherent interests, create opportunities for active learning and higher-order thinking, and prepare students for the challenges of tomorrow’s workplace. However, schools also need to protect students against cyberbullies, online predators, and exposure to inappropriate content. The project concludes that allowing Web 2.0 tools into classrooms while developing responsible computing skills across the curriculum outweighs any perceived risks. The proposal outlines an adoption plan that factors in educational activities, staff development, budget, and progress monitoring