The emergence of insect resistance in Bt-corn: implication of resistance management information under uncertainty

"The successful management of transgenic technology is likely to depend on the economic behavioral response of farmers to the regulated use of transgenic crops. A well-studied example is the widespread use of Bt-corn, in the United States, and elsewhere, to control the European Corn Borer, a major corn pest. The extensive use of Bt-corn has led to concerns about the emergence of insect resistance. The United States Environment Protection Agency addressed this potential problem by developing an insect resistance management strategy, based, in part, on complex mathematical models using detailed biological assumptions about the population genetics and life history of the European Corn Borer. However, seed companies and others have sometimes used simpler deterministic profit models to justify the economics of Bt-corn to potential growers. Therefore an over reliance, by regulatory agencies, on complex modeling approaches may obscure the likely economic behavioral response of farmers who rely on these less complex models. However, the determinants of adoption are numerous, profit being one of them. We develop a simple model for the spread of resistance based on the logistic growth equation and use it to investigate the effect of uncertainty on farmer decisions to plant Bt-corn and follow EPA management rules. The model results suggest that planting Bt-corn is an optimal strategy under the type of uncertainty assumed in the model and that short-term economic behavior is likely to lead to the Environment Protection Agency management rules not being followed. Our results add weight to existing work on this problem." Authors' AbstractBt-corn, logistic growth, Monte Carlo methods, Corn, Environmental protection, Economics Methodology,

Relationship marketing and client trust towards contractors within the large private building sector of the UK construction industry

A history of adversarial relationships, resulting in conflict between parties involved in building projects has raised levels of perceived risk for clients working with contractors. Therefore, traditional approaches to marketing management have been found to be inappropriate. The new development in relationship marketing may assist contractors in developing more appropriate marketing strategies. However, trust is essential to the development of positive on-going relationships and if future relationship marketing strategiesa re going to work, this must first be addressedW. ith calls for the development of trust, the thesis concentrateso n this, whilst taking into considerationt he complex exchangep rocessb etweenc lients and contractorse xisting over an extendedp eriod of time in any one project. This within what is calledt he TemporaryM ulti-organisation( TMO). From the client decision-maker's(C DNI) perspectivein the large private building sector of the UK construction industry, this thesis empirically examines client attitude and consequentiabl eliefs about, trusting contractors. It also examinesc ontractor behaviour affecting client willingness to trust them, whilst allowing for the influence other parties within the TMO have on CDM perspectiveo f the contractor. To do this, two models,t he 'ReasonedA ction Model' and 'Conditions of Trust InventorV were executed together through a carefully designedq uestionnaires urvey sent to key decision-makers'i n 590 leading large client organisationss uch as BAA, British Land, and major retail, hotel and leisure companies.D epth interviews with leading UK CDM's were used in conjunction with prescribedp racticet o aid in the designa nd contento f the questionnaire. Given the history of client-contractor relationships, results revealed some interesting findings. Third party influence from architects, colleagues within the CD"s firm, contractorsp ast clients and sub-contractorsw ere found to be the dominanti nfluenceo ver CDM trust of contractors. Results also show CDM's consider being able to trust contractors as important, reasonablea nd beneficial. This leads to fewer problemsw ith disclosureo f information, less monitoring of contractor performancei n terms of quality checksa nd greater likelihood of a successfupl roject. Also, all ten 'Conditions of Trust' relating to CDM's past experienceo f contractor behavioura re shown to be affecting the development of trust for future projects. The research makes an original contribution, providing insight into issues affecting client trust toward contractors during projects, whilst identifying areasf or action if trust is to be developed.I t also provides marketing theory with an insight into trust and relationshipm anagemenwt ith the TNIO, a forerunner to modem virtual organisations

An AGN Identification for 3EG J2006-2321

We present a multiwavelength analysis of the high-energy gamma-ray source 3EG J2006-2321. The flux of this source above 100 MeV is shown to be variable on time scales of days and months. Optical observations and careful examination of archived radio data indicate that its radio counterpart is PMN J2005-2310, a flat-spectrum radio quasar with a 5-GHz flux density of 260 mJy. Study of the $V=18.7$ optical counterpart indicates a redshift of 0.833 and variable linear polarization. No X-ray source has been detected near the position of PMN J2005-2310, but an X-ray upper limit is derived from ROSAT data. This upper limit provides for a spectral energy distribution with global characteristics similar to those of known gamma-ray blazars. Taken together, these data indicate that 3EG J2006-2321, listed as unidentified in the 3rd EGRET Catalog, is a member of the blazar class of AGN. The 5-GHz radio flux density of this blazar is the lowest of the 68 EGRET-detected AGN. The fact that EGRET has detected such a source has implications for unidentified EGRET sources, particularly those at high latitudes ($|b|>30^{\circ}$), many of which may be blazars.Comment: 22 pages, 6 figures. To appear in ApJ v569 n1, 10 April 200

Consensual Qualitative Research: An Update

The authors reviewed the application of consensual qualitative research (CQR) in 27 studies published since the method’s introduction to the field in 1997 by C. E. Hill, B. J. Thompson, and E. N. Williams (1997). After first describing the core components and the philosophical underpinnings of CQR, the authors examined how it has been applied in terms of the consensus process, biases, research teams, data collection, data analysis, and writing up the results and discussion sections of articles. On the basis of problems that have arisen in each of these areas, the authors made recommendations for modifications of the method. The authors concluded that CQR is a viable qualitative method and suggest several ideas for research on the method itself

Endovascular repair of ruptured abdominal aortic aneurysm: A strategy in need of definitive evidence

IntroductionEndovascular strategies have been increasingly used to manage patients with ruptured abdominal aortic aneurysm (AAA) in an attempt to improve patient survival. We analyzed the evidence to support such an approach.MethodsWe performed a systematic literature review of endovascular aneurysm repair (EVAR) of ruptured AAA from 1994 to 2009. The literature analyzed included systematic reviews and population-based studies of ruptured AAA.ResultsSeven systematic reviews were identified, all demonstrating from published data that patients with EVAR of ruptured AAA had significantly reduced mortality compared with controls. Six recently published population-based studies from the United States demonstrated low mortality rates associated with EVAR; however, only a small proportion of ruptured AAAs were treated by EVAR. Systematic reviews and population-based studies both raised concerns about patient selection and publication bias. Two randomized trials are in progress, and one is due to commence 2009.ConclusionsThe outcome of EVAR in a nonselected patient population remains unknown. One or more definitive randomized trials could provide the level I evidence to resolve these issues

A Case Study of Institutional Visioning, Public Good, and the Renewal of Democracy: The Theory and Practice of Public Good Work at the University of Denver

In 2001, the University of Denver included language in its vision statement that committed the institution to becoming “a great private university dedicated to the public good.” This essay (1) explains how the development of an institutional visioning statement led to the implementation of a series of campus dialoguesand action steps designed to forward public good work at the university; (2) presents campus conversations and current literature to offer a theory of public good work within private research universities; and (3) documents challenges and lessons learned through institutional efforts to embrace a culture of engagement

Lake-level Variability and Water Availability in the Great Lakes

Key components of water availability in a hydrologic system4 are the amount of water in storage and the variability of that amount. In the Great Lakes Basin, a vast amount of water is stored in the lakes themselves. Because of the lakes’ size, small changes in water levels cause huge changes in the amount of water in storage. Approximately 5,439 mi3 of water, measured at chart datum, is stored in the Great Lakes. A change of 1 ft in water level over the total Great Lakes surface area of 94,250 mi2 means a change of 18 mi3 of water in storage. Changes in lake level over time also play an important role in human activities and in coastal processes and nearshore ecosystems, including development and maintenance of beaches, dunes, and wetlands. The purpose of this report is to present recorded and reconstructed (pre-historical) changes in water levels in the Great Lakes, relate them to climate changes of the past, and highlight major water-availability implications for storage, coastal ecosystems, and human activities. Reconstructed water-level changes have not been completed for all Great Lakes; consequently, this report presents these changes primarily for Lakes Michigan and Huron, with some reference to Lake Superior also

Student Awareness of Models in First-Year Engineering Courses

Contribution: This study assesses more than 800 students\u27 awareness of engineering model types before and after taking two first-year engineering courses across two semesters and evaluates the effect of each course. Background: All engineers must be able to apply and create models to be effective problem solvers, critical thinkers, and innovative designers. To help them develop these skills, as a first step, it is essential to assess how to increase students\u27 awareness of engineering models. According to Bloom\u27s taxonomy, the lower remember and understand levels, which encompass awareness, are necessary for achieving the higher levels, such as apply, analyze, evaluate, and create. Research Questions: To what extent did student awareness of model types change after taking introductory engineering courses? To what extent did student awareness of model types differ by course or semester? Methodology: In this study, a survey was designed and administered at the beginning and end of the semester in two first-year engineering courses during two semesters in a mid-sized private school. The survey asked students questions about their definition of engineering modeling and different types of models. Findings: Overall, student awareness of model types increased from the beginning of the semester toward the end of the semester, across both semesters and courses. There were some differences between course sections, however, the students\u27 awareness of the models at the end of the academic year was similar for both groups

The Case and Context for Atmospheric Methane as an Exoplanet Biosignature

Methane has been proposed as an exoplanet biosignature. Imminent observations with the James Webb Space Telescope may enable methane detections on potentially habitable exoplanets, so it is essential to assess in what planetary contexts methane is a compelling biosignature. Methane's short photochemical lifetime in terrestrial planet atmospheres implies that abundant methane requires large replenishment fluxes. While methane can be produced by a variety of abiotic mechanisms such as outgassing, serpentinizing reactions, and impacts, we argue that, in contrast to an Earth-like biosphere, known abiotic processes cannot easily generate atmospheres rich in CH$_4$ and CO$_2$ with limited CO due to the strong redox disequilibrium between CH$_4$ and CO$_2$. Methane is thus more likely to be biogenic for planets with 1) a terrestrial bulk density, high mean-molecular-weight and anoxic atmosphere, and an old host star; 2) an abundance of CH$_4$ that implies surface fluxes exceeding what could be supplied by abiotic processes; and 3) atmospheric CO$_2$ with comparatively little CO.Comment: 10 pages, 5 figures, 15 pages Supplementary Information, 3 Supplementary Figure