The Hydroacoustic Network of the CTBT International Monitoring System: Access and Exploitation

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Paranotis halfordii (Rubiaceae: Spermacoceae), a new species from the Kimberley region of Western Australia, in a recently described Australian genus

Paranotis halfordii K.L.Gibbons & S.J.Dillon, a new species from the Dampierland and Central Kimberley IBRA bioregions of Western Australia, is here described. Paranotis Pedley ex K.L.Gibbons was recently described to include some Australian species previously included in Oldenlandia L. A key to the species of Paranotis is provided

Effects of Family, Friends, and Relative Prices on Fruit and Vegetable Consumption by African American Youths

Facilitating healthy eating among young people, particularly among minorities who are at high risk for gaining excess weight, is at the forefront of current policy discussions and food program reviews. We investigate the effects of social interactions and relative prices on fruit and vegetable consumption by African American youths using rich behavioral data from the Family and Community Health Study and area-specific food prices. We find the presence of endogenous effects between a youth and parent, but not between a youth and friend. Lower relative prices of fruits and vegetables tend to increase intakes. Results suggest that health interventions targeting a family member may be an effective way to increase fruit and vegetable intake by African Americans as a result of spillover consumption effects between the youths and parents.social interactions, healthy food choices, fruit and vegetable consumption, African American youth, Agricultural and Food Policy, Consumer/Household Economics, Demand and Price Analysis, Food Consumption/Nutrition/Food Safety, Health Economics and Policy, Institutional and Behavioral Economics, I12, J15, C35,

The 27 February 2022 Lop Nor Earthquake: Detectability, Location, and Discrimination

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Scalar Absorption and the Breaking of the World Volume Conformal Invariance

We investigate a version of fixed scalars for non-dilatonic branes which correspond to dilatations of the brane world-volume. We obtain a cross-section whose world-volume interpretation falls out naturally from an investigation of the breaking of conformal invariance by the irrelevant Born-Infeld corrections to Yang-Mills theory. From the same irrelevant world-volume operator we obtain the leading correction to the cross-sections of minimal scalars. This correction can be obtained in supergravity via an improved matching of inner and outer solutions to the minimal wave equation.Comment: 20 pages, 2 figures. Minor change

The effects of room design on computer-supported collaborative learning in a multi-touch classroom.

While research indicates that technology can be useful for supporting learning and collaboration, there is still relatively little uptake or widespread implementation of these technologies in classrooms. In this paper, we explore one aspect of the development of a multi-touch classroom, looking at two different designs of the classroom environment to explore how classroom layout may influence group interaction and learning. Three classes of students working in groups of four were taught in the traditional forward-facing room condition, while three classes worked in a centered room condition. Our results indicate that while the outcomes on tasks were similar across conditions, groups engaged in more talk (but not more off-task talk) in a centered room layout, than in a traditional forward-facing room. These results suggest that the use of technology in the classroom may be influenced by the location of the technology, both in terms of the learning outcomes and the interaction behaviors of students. The findings highlight the importance of considering the learning environment when designing technology to support learning, and ensuring that integration of technology into formal learning environments is done with attention to how the technology may disrupt, or contribute to, the classroom interaction practices

Dynamics of Extremal Black Holes

Particle scattering and radiation by a magnetically charged, dilatonic black hole is investigated near the extremal limit at which the mass is a constant times the charge. Near this limit a neighborhood of the horizon of the black hole is closely approximated by a trivial product of a two-dimensional black hole with a sphere. This is shown to imply that the scattering of long-wavelength particles can be described by a (previously analyzed) two-dimensional effective field theory, and is related to the formation/evaporation of two-dimensional black holes. The scattering proceeds via particle capture followed by Hawking re-emission, and naively appears to violate unitarity. However this conclusion can be altered when the effects of backreaction are included. Particle-hole scattering is discussed in the light of a recent analysis of the two-dimensional backreaction problem. It is argued that the quantum mechanical possibility of scattering off of extremal black holes implies the potential existence of additional quantum numbers - referred to as ``quantum whiskers'' - characterizing the black hole.Comment: 31 page

Evanescent Black Holes

A renormalizable theory of quantum gravity coupled to a dilaton and conformal matter in two space-time dimensions is analyzed. The theory is shown to be exactly solvable classically. Included among the exact classical solutions are configurations describing the formation of a black hole by collapsing matter. The problem of Hawking radiation and backreaction of the metric is analyzed to leading order in a $1/N$ expansion, where $N$ is the number of matter fields. The results suggest that the collapsing matter radiates away all of its energy before an event horizon has a chance to form, and black holes thereby disappear from the quantum mechanical spectrum. It is argued that the matter asymptotically approaches a zero-energy ``bound state'' which can carry global quantum numbers and that a unitary $S$-matrix including such states should exist.Comment: 14 page