Changing preferences: an experiment and estimation of market-incentive effects on altruism

This paper studies how altruistic preferences are changed by markets and incentives. We conduct a laboratory experiment in a within-subject design. Subjects are asked to choose health care qualities for hypothetical patients in monopoly, duopoly, and quadropoly. Prices, costs, and patient benefits are experimental incentive parameters. In monopoly, subjects choose quality to tradeoff between profits and altruistic patient benefits. In duopoly and quadropoly, we model subjects playing a simultaneous-move game. Each subject is uncertain about an opponent's altruism, and competes for patients by choosing qualities. Bayes-Nash equilibria describe subjects' quality decisions as functions of altruism. Using a nonparametric method, we estimate the population altruism distributions from Bayes-Nash equilibrium qualities in different markets and incentive configurations. Markets tend to reduce altruism, although duopoly and quadropoly equilibrium qualities are much higher than those in monopoly. Although markets crowd out altruism, the disciplinary powers of market competition are stronger. Counterfactuals confirm markets change preferences.Accepted manuscrip

Deagglomeration and mixing via the rapid expansion of high pressure and supercritical suspensions

Nano-materials are the focus of many research activities due to the desirable properties imparted from their small grain size and high interfacial surface area. However, these materials are highly cohesive powders in the dry state and typically form large agglomerates, leading to a diminished surface area or even grain growth, which minimizes the effectiveness of these nanomaterials. This dissertation addresses the issue of mixing nanopowders constituents by deagglomerating them and achieving simultaneous mixing so that even after inevitable reagglomeration, the effectiveness of large interfacial surface area may be preserved. Nano-particle mixtures were prepared using the environmentally benign dry mixing methods of Stirring in Supercritical Fluids and the Rapid Expansion of High Pressure and Supercritical Suspensions (REHPS). Stirring in Supercritical Fluids was capable of producing course scale nano-particle mixtures that were comparable to mixtures produced with more traditional liquid solvents, without the necessity of filtration and caking issues that are typically associated with them. The REHPS process was capable of producing high-quality mixtures on the sub-micron scale, and was made far superior when the nano-powders were first pre-mixed by stirring to decrease inhomogeneity of the feed. It was also shown that in general, conditions that enhanced turbulent shear stress, and thereby deagglomeration, also enhanced mixing, however this effect could be obscured by inhomogeneities introduced by the feed mixtures. Previous authors have suggested that the primary deagglomeration mechanism is the explosive expansion of the carbon dioxide from within the agglomerate as it transitions from a high pressure to an ambient environment. In this study two other deagglomeration mechanisms were proposed, namely intense turbulent shear stress imparted by the fluid in the nozzle and impaction with the Mach disc near the exit of the nozzle. Explosive expansion was observed to have almost no effect on nozzle deagglomeration and subsequent mixing. It has been shown that the turbulent shear stress and the residence time under shear were the dominant factors related to agglomerate breakage, while impaction with the Mach disc has played a minimal role

Evaluation of matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) for the Identification of Group B Streptococcus.

Objective Group B Streptococcus (GBS) is a leading cause of neonatal meningitis and sepsis worldwide. Intrapartum antibiotics given to women carrying GBS are an effective means of reducing disease in the first week of life. Rapid and reliable tests are needed to accurately identify GBS from these women for timely intrapartum antibiotic administration to prevent neonatal disease. Many laboratories now use matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) by direct plating or cell lysis for the identification of GBS isolates. The cell lysis step increases time to results for clinical samples and is more complex to perform. Therefore, we seek to evaluate the sensitivity and specificity of the quicker and more rapid direct plating method in identifying GBS. Results We directly compared swab isolates analysed by both direct plating and cell lysis method and demonstrated that direct plating has a sensitivity and specificity of 0.97 and 1, respectively, compared to an additional cell lysis step. We demonstrated that MALDI-TOF MS can be successfully used for batch processing by the direct plating method which saves time. These results are reassuring for laboratories worldwide who seek to identify GBS from swabs samples as quickly as possible

Radioactive Contamination of Water At the Santa Susana Field Laboratory

Presentation to SSFL InterAgency Work Group Community Meeting. Contains presentation slides in pdf format. This research was completed money allocated during Round 6 of the Citizens’ Monitoring and Technical Assessment Fund (MTA Fund). Clark University was named conservator of these works. If you have any questions or concerns please contact us at [email protected]://commons.clarku.edu/bridge_gap/1003/thumbnail.jp

Nuclear Cleanup: The Standards Conflict

The U.S. Department of Energy has recently violated a longstanding Joint DOE-EPA Policy which commits DOE to clean up all its nuclear facilities nationwide to the Environmental Protection Agency (EPA) Superfund (CERCLA) standards. The focal point of this conflict between DOE and EPA cleanup standards is the Santa Susana Field Laboratory (SSFL), a 2800- acre facility on the Los Angeles-Ventura County line in Southern California. Ten reactors, a plutonium fuel facility, and a “hot laboratory” for cutting up irradiated nuclear fuel were operated at the facility, which opened in the 1940s when it was remote from populated areas. Now large numbers of people live nearby. One of the reactors suffered a partial meltdown in 1959; two others experienced damage in 1964 and 1969 to 80% and 35% of their fuel, respectively. In 1989, DOE found widespread chemical and radioactive contamination at the site, and a cleanup program commenced. In 1995, DOE and EPA entered into a Joint Policy to assure that all DOE sites, whether or not they were on the National Priority List (Superfund), would be cleaned up consistent with EPA’s CERCLA standards. In March of 2003, DOE reversed course and, while claiming to still follow the 1995 Policy, announced it would not clean the site up to the EPA standards. It would remove only 1% of the contaminated soil and then release the site for unrestricted residential use. In December 2003, EPA issued findings that the site was not being cleaned up consistent with the 1995 Joint Policy and that under the circumstances, so much radioactivity could be left in place that residential use would be unsafe and the only safe use would be restricted dayhikes with limitations on picnicking. To date no detailed study has been done comparing the DOE and EPA cleanup standards. This report, supported by a grant from the Citizens’ Monitoring and Technical Assistance Fund, performs that analysis. The evaluation demonstrates that DOE’s decision not to comply with EPA’s cleanup standards will result in radionuclide concentrations being permitted that are hundreds, thousands, tens of thousands, and in some cases, hundreds of thousands of times higher than EPA’s primary cleanup goals. For most radionuclides, the associated risk exceeds even the uppermost permissible risk level of EPA under CERCLA. In some cases, those cancer risks rise to levels on the order of one cancer per ten people exposed, using the federal government’s official radiation risk figures. Should DOE proceed with acting in contravention of the 1995 DOE-EPA Joint Policy on cleaning up DOE sites consistent with CERCLA at SSFL, there would be significant ramifications for the DOE nuclear complex nationwide, and for public health. This research was completed money allocated during Round 4 of the Citizens’ Monitoring and Technical Assessment Fund (MTA Fund). Clark University was named conservator of these works. If you have any questions or concerns please contact us at [email protected]://commons.clarku.edu/bridge_gap/1000/thumbnail.jp

Radioactive Contamination at Dayton Canyon from the Santa Susana Filed Laboratory

Radioactive Contamination at Dayton Canyon from the Santa Susana Filed Laboratory was a report that was deeply flawed as the result of the Department of Toxic Substances Control (DTSC) misrepresenting the underlying data , as well as poor protection levels and an a priori assumption that there can\u27t be contamination coming from Santa Susana Field Laboratory (SSFL). It should be rejected. Correspondence and context for this failed study, and the ways the Committee to Bridge the Gap and its researchers were led astray by aforementioned parties, is documented in detail here. This research was completed money allocated during Round 6 of the Citizens’ Monitoring and Technical Assessment Fund (MTA Fund). Clark University was named conservator of these works. If you have any questions or concerns please contact us at [email protected]://commons.clarku.edu/bridge_gap/1002/thumbnail.jp

Radioactive Contamination at Runkle Ranch from the Santa Susana Field Laboratory

Runkle Ranch is the site of a proposed residential development in Simi Valley. Because it is located near to, and below, the Santa Susana Field Laboratory ((SFL), a nuclear reactor and rocket testing and development facility with significant radioactive and chemical contamination, the developer arranged for a series of tests of soil and other environmental media. SSFL is operated for the U.S. government by the Rocketdyne Division of the Boeing Company. This report examines the results of the soil testing for radioactivity. The Environmental Impact Report (EIR) that supported the approval of the project briefly addressed the potential for contaminants from SSFL to have impacted the Runkle Ranch land and concluded that this was not an issue. The EIR1 noted that background levels of strontium-90 are “about 0.1 pico Curie per gram (pCi/g)” and went on to describe sampling results for the Runkle property: Previous assessments of strontium-90 and tritium within the vicinity of the [Runkle Canyon] Specific Plan Area included a survey conducted by QST Environmental, Inc. in 1998. This study was conducted to determine if nuclear 1 This and the following two quotes are from pp. 4.6-6 and 4.6-7 of the EIR. 2 reactor operations at the SSFL facility had impacted soil at the site through surface water runoff. Four soil samples at three were collected and analyzed for cesium-137, strontium-90 and tritium. One of the locations was within a natural drainage channel flowing from the locale of the SSFL facility towards the northeastern portion of the Specific Plan Area. The results of the survey indicated that the surface soil contained concentrations of cesium-137 and strontium-90 that exceeded background levels established by the EPA. Because of the initial findings, followup sampling was initiated. As the EIR states: Consequently, further testing was indicated. Tritium was also detected in the samples, but at concentrations below the EPA background levels. A limited radiation survey was conducted during subsequent testing and analysis in the Phase I ESA for the 550-acre parcel referenced in this section. This assessment found that radiation levels were within normal background levels. Tritium and strontium-90 were not detected in any of the soil and groundwater samples at levels above normal background levels or at levels considered to pose a health risk. (emphasis added). This conclusion is puzzling, because the actual measurements being cited for the proposition that none were above background nor above levels considered to pose a health risk show precisely the opposite. Rather than none of the samples being above background or health risk levels, ALL 58 of the 1999 follow-up strontium measurements exceeded the 0.1 pCi/gram background figure cited in the EIR (as we shall see, that figure is actually twice background), and virtually all exceed the EPA’s Preliminary Remediation Goals (PRGs). This research was completed money allocated during Round 6 of the Citizens’ Monitoring and Technical Assessment Fund (MTA Fund). Clark University was named conservator of these works. If you have any questions or concerns please contact us at [email protected]://commons.clarku.edu/bridge_gap/1001/thumbnail.jp

Cryptographic applications of sparse polynomials over finite rings

This is a preprint of a book chapter published in Lecture Notes in Computer Science, 2015, Springer-Verlag, Berlin (2001). The original publication is available at www.springerlink.com.This paper gives new examples that exploit the idea of using sparse polynomials with restricted coefficients over a finite ring for designing fast, reliable cryptosystems and identification schemes

Phylogenetic Networks Do not Need to Be Complex: Using Fewer Reticulations to Represent Conflicting Clusters

Phylogenetic trees are widely used to display estimates of how groups of species evolved. Each phylogenetic tree can be seen as a collection of clusters, subgroups of the species that evolved from a common ancestor. When phylogenetic trees are obtained for several data sets (e.g. for different genes), then their clusters are often contradicting. Consequently, the set of all clusters of such a data set cannot be combined into a single phylogenetic tree. Phylogenetic networks are a generalization of phylogenetic trees that can be used to display more complex evolutionary histories, including reticulate events such as hybridizations, recombinations and horizontal gene transfers. Here we present the new CASS algorithm that can combine any set of clusters into a phylogenetic network. We show that the networks constructed by CASS are usually simpler than networks constructed by other available methods. Moreover, we show that CASS is guaranteed to produce a network with at most two reticulations per biconnected component, whenever such a network exists. We have implemented CASS and integrated it in the freely available Dendroscope software