115 research outputs found
Beyond the Lamppost: Optimal Prevention and Control of the Brown Treesnake in Hawaii
In this paper, an integrated model for the prevention and control of an invasive species is developed. The generality of the model allows it to be used for both existing and potential threats to the system of interest. The deterministic nature of arrivals in the model allows for a clear examination of the tradeoffs inherent when choosing between prevention and control strategies. We illuminate how optimal expenditure paths change in response to various biological and economic parameters for the case of the Brown treesnake in Hawaii. Results suggest that it is more advantageous to spend money finding the small population of snakes as they occur than attempting to prevent all future introductions. Like the drunk that looks for his keys only where the light is, public policy may fail to look âbeyond the lamppostâ for snakes that have already arrived but have not yet been detected. Actively searching for a potential population of snakes rather than waiting for an accidental discovery may save Hawaii tens to hundreds of millions of dollars in future damages, interdiction expenditures, and control costs.invasive species, brown tree snake, Boiga irregularis, prevention and control, Hawaii
Evaluation of diffusive gradients in thin-films using a DiphonixÂŽ resin for monitoring dissolved uranium in natural waters
Commercially available DiphonixÂŽ resin (TrisKem International) was evaluated as a receiving phase for use with the diffusive gradients in thin-films (DGT) passive sampler for measuring uranium. This resin has a high partition coefficient for actinides and is used in the nuclear industry. Other resins used as receiving phases with DGT for measuring uranium have been prone to saturation and significant chemical interferences. The performance of the device was evaluated in the laboratory and in field trials. In laboratory experiments uptake of uranium (all 100% efficiency) by the resin was unaffected by varying pH (4â9), ionic strength (0.01â1.00 M, as NaNO3) and varying aqueous concentrations of Ca2+ (100â500 mg Lâ1) and HCO3â (100â500 mg Lâ1). Due to the high partition coefficient of DiphonexÂŽ, several elution techniques for uranium were evaluated. The optimal eluent mixture was 1 M NaOH/1 M H2O2, eluting 90% of the uranium from the resin. Uptake of uranium was linear (R2 = 0.99) over time (5 days) in laboratory experiments using artificial freshwater showing no saturation effects of the resin. In field deployments (River Lambourn, UK) the devices quantitatively accumulated uranium for up to 7 days. In both studies uptake of uranium matched that theoretically predicted for the DGT. Similar experiments in seawater did not follow the DGT theoretical uptake and the DiphonixÂŽ appeared to be capacity limited and also affected by matrix interferences. Isotopes of uranium (U235/U238) were measured in both environments with a precision and accuracy of 1.6â2.2% and 1.2â1.4%, respectively. This initial study shows the potential of using DiphonixÂŽ-DGT for monitoring of uranium in the aquatic environment
Oracy curriculum, culture and assessment toolkit
This report evaluates a developmental project designed by School 21 and the University of Cambridge to improve Year 7 students' oracy skills. The project involved developing an Oracy Skills Framework, which sets out the physical, linguistic, cognitive, and social-emotional oracy skills
required by students for education and life. Other components which were informed by this framework are:
⢠a dedicated Year 7 oracy curriculum comprising weekly oracy lessons;
⢠oracy in every lesson;
⢠building a whole school oracy culture; and
⢠an Oracy Assessment Toolkit.
These components were piloted and further developed with Year 7 students within School 21 from September 2013 to July 2014. During the final stages of the project the components were brought together to create an 'Oracy Curriculum, Culture and Assessment Toolkit' that can be adopted by other schools and a website was created, Voice 21 (http://voice21.org/), containing guidance and
resources for schools using the Toolkit.
This report focuses on an evaluation of:
1. The approaches and materials which formed the Oracy Curriculum, Culture and Assessment Toolkit, including an indicative impact finding on the impact on Year 7 pupils in School 21.
2. What further development of the Oracy Curriculum, Culture and Assessment Toolkit is needed and would enable a more robust evaluation of its impact
Economic analysis of the proposed rule to prevent arrival of new genetic strains of the rust fungus Puccinia psidii in Hawaiâi
Reports were scanned in black and white at a resolution of 600 dots per inch and were converted to text using Adobe Paper Capture Plug-in.Since its first documented introduction to Hawaiâi in 2005, the rust fungus P. psidii has already severely damaged Syzygium jambos (Indian rose apple) trees and the federally-endangered Eugenia koolauensis (nioi). Fortunately, the particular strain has yet to cause serious damage to âĹhiâa, which comprises roughly 80% of the stateâs native forests and covers 400,000 ha. Although the rust has affected less than 5% of Hawaiiâs âĹhiâa trees thus far, the introduction of more virulent strains and the genetic evolution of the current strain are still possible. Since the primary pathway of introduction is Myrtaceae plant material imported from outside the state, potential damage to âohiâa can be minimized by regulating those high-risk imports. We discuss the economic impact on the stateâs florist, nursery, landscaping, and forest plantation industries of a proposed rule that would ban the import of non-seed Myrtaceae plant material and require a one-year quarantine of seeds. Our analysis suggests that the benefits to the forest plantation industry of a complete ban on non-seed material would likely outweigh the costs to other affected sectors, even without considering the reduction in risk to âĹhiâa. Incorporating the value of âĹhiâa protection would further increase the benefit-cost ratio in favor of an import ban
UK: racial violence and the night-time economy
This article examines fifty-five racist attacks over a six-month period in the UKâs night-time economy, showing the risks faced by members of the public and workers at taxi firms, takeaways, convenience stores and service stations. It argues that flexible and highly casualised labour conditions exacerbate the risk of racial violence
Determining Socio-Economic Impacts of New Gaming Venues in Four Lower Mainland Communities: Socio-Economic Issues and Impacts: First Impact Measures Report
Permission granted by the British Columbia Intellectual Property Program to reproduce this publication.The purpose of the study is to learn what, if any, economic and social costs and benefits emerge over time from the creation and operation of these four new venues. Its
intent is to inform planning processes
by the provincial government and other
stakeholders. The study is being done in
three waves:
Baseline (2004)
First Impact Measures (2005)
Final Report with Second Impact
Measures (2006)
This document constitutes the first impact
report. It compares present (2005) data with
baseline social and economic data gathered
prior to and during the opening of three of
the four gaming venues (2004). The impact
analysis in this report is limited because it is based on data collected shortly after the Casino opening dates. These delays were
not anticipated at the start of the project,
however the final report due in 2007 will have sufficient data to support impact analysis. The report is divided into two sections, Social Impacts and Economic Impacts.Ye
Gravitational Energy in Spherical Symmetry
Various properties of the Misner-Sharp spherically symmetric gravitational
energy E are established or reviewed. In the Newtonian limit of a perfect
fluid, E yields the Newtonian mass to leading order and the Newtonian kinetic
and potential energy to the next order. For test particles, the corresponding
Hajicek energy is conserved and has the behaviour appropriate to energy in the
Newtonian and special-relativistic limits. In the small-sphere limit, the
leading term in E is the product of volume and the energy density of the
matter. In vacuo, E reduces to the Schwarzschild energy. At null and spatial
infinity, E reduces to the Bondi-Sachs and Arnowitt-Deser-Misner energies
respectively. The conserved Kodama current has charge E. A sphere is trapped if
E>r/2, marginal if E=r/2 and untrapped if E<r/2, where r is the areal radius. A
central singularity is spatial and trapped if E>0, and temporal and untrapped
if E<0. On an untrapped sphere, E is non-decreasing in any outgoing spatial or
null direction, assuming the dominant energy condition. It follows that E>=0 on
an untrapped spatial hypersurface with regular centre, and E>=r_0/2 on an
untrapped spatial hypersurface bounded at the inward end by a marginal sphere
of radius r_0. All these inequalities extend to the asymptotic energies,
recovering the Bondi-Sachs energy loss and the positivity of the asymptotic
energies, as well as proving the conjectured Penrose inequality for black or
white holes. Implications for the cosmic censorship hypothesis and for general
definitions of gravitational energy are discussed.Comment: 23 pages. Belatedly replaced with substantially extended published
versio
Gleam: the GLAST Large Area Telescope Simulation Framework
This paper presents the simulation of the GLAST high energy gamma-ray
telescope. The simulation package, written in C++, is based on the Geant4
toolkit, and it is integrated into a general framework used to process events.
A detailed simulation of the electronic signals inside Silicon detectors has
been provided and it is used for the particle tracking, which is handled by a
dedicated software. A unique repository for the geometrical description of the
detector has been realized using the XML language and a C++ library to access
this information has been designed and implemented.Comment: 10 pages, Late
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