10,808 research outputs found
A new species of Boettcheria from Guatemala (Diptera: Sarcophagidae)
Boettcheria styx new species is described from Guatemala, and a key is provided to separate it from B. maerens (Townsend). A list is given of Central American species of Boettcheria with references to figures of their genitalia
The relation between the shock-induced free-surface velocity and the postshock specific volume of solids
The release of solids from a state of shock compression at a free surface is examined. For isentropic release, the postshock specific volume V[prime]0 is shown to be constrained by V[prime]0? (Ufs–Up)2/P1+V1, where (P1,V1) is the pressure-volume Hugoniot state of shock compression and Ufs and Up are the free-surface and shock particle velocities, respectively. When a sudden phase change occurs during the release process, this lower bound is increased, subject to simplifying assumptions about the phase transition
CONSUMER RESPONSE TO GENETICALLY MODIFIED FOODS: MARKET SEGMENT ANALYSIS AND IMPLICATIONS FOR PRODUCERS AND POLICY MAKERS
Conjoint analysis is used to elicit consumer preferences for attributes of genetically modified foods. Market segments are identified based on a cluster analysis of respondents' preferences for brand, price, and GMO content. A logit analysis is used to analyze consumer characteristics associated with the acceptance of GMO foods. Those consumers who were most risk averse, most likely to believe that GMOs improved the quality or safety of food, and most knowledgeable about biotechnology were the most likely to be accepting of GMO foods. These findings are used to develop implications for producers and regulators of GMO foods.Agricultural and Food Policy, Consumer/Household Economics,
On the Struggle To Attain Universal Competence in a Complex Skill: The Case of a Senior Capstone Experience
Seventeen years ago, a blue-ribbon committee of economists asserted that the “ideal” program for an economics major should include “a capstone experience, whereby students apply their knowledge and skills in creative and systematic ways through research and writing.” (Seigfried, Bartlett, Hansen, Kelley, McCloskey, and Tietenberg (1991)) Yet we are not aware of a data-driven assessment of an implemented senior capstone experience in the economics education literature. We have been experimenting with a senior capstone experience – based on research and writing – for more than a decade. In this paper we describe the history of our senior capstone experience, and provide a data-driven assessment of student performance in this experience. Our primary objective for this senior capstone has been to create a system that will result in all of our majors writing a competent senior thesis. In other words, we want to attain universal competence in a complex skill. This simple objective has, however, been very difficult to achieve. We will argue that undesired variation in student motivation has been our primary obstacle in attaining universal competence.
Future of Water Law Reform in California a Quarter Century after the Governor\u27s Commission, The
Doing More with Less: Remaining Opportunities for “Tuning the System”: The Potential for Central Valley System-Wide Conjunctive Water Management
30 pages (includes illustrations).
Contains footnotes
PAH in the laboratory and interstellar space
The theory that polycyclic aromatic hydrocarbons (PAHs) are a constituent of the interstellar medium, and a source of the IR emission bands at 3.3, 6.2, 7.7, 8.6, and 11.3 microns is being studied using PAH containing acid insoluble residue of the Orgueil CI meteorite and coal tar. FTIR spectra of Orgueil PAH material that has undergone thermal treatment, and a solvent insoluble fraction of coal tar that has been exposed to hydrogen plasma are presented. The UV excided luminescence spectrum of a solvent soluble coal tar film is also shown. Comparison of the lab measurements with observations appears to support the interstellar PAH theory, and shows the process of dehydrogenation expected to take place in the interstellar medium
A Two-Coordinate Nickel Imido Complex That Effects C−H Amination
An exceptionally low coordinate nickel imido complex, (IPr*)Ni═N(dmp) (2) (dmp = 2,6-dimesitylphenyl), has been prepared by the elimination of N_2 from a bulky aryl azide in its reaction with (IPr*)Ni(η^6-C_7H_8) (1). The solid-state structure of 2 features two-coordinate nickel with a linear C−Ni−N core and a short Ni−N distance, both indicative of multiple-bond character. Computational studies using density functional theory showed a Ni═N bond dominated by Ni(dπ)−N(pπ) interactions, resulting in two nearly degenerate singly occupied molecular orbitals (SOMOs) that are Ni−N π* in character. Reaction of 2 with CO resulted in nitrene-group transfer to form (dmp)NCO and (IPr*)Ni(CO)_3 (3). Net C−H insertion was observed in the reaction of 2 with ethene, forming the vinylamine (dmp)NH(CH═CH_2) (5) via an azanickelacyclobutane intermediate, (IPr*)Ni{N,C:κ^2-N(dmp)CH_2CH_2} (4)
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