Simulating the Water Requirements and Economic Feasibility of Corn in the Midwest

An evaluation of the economics of supplemental irrigation when using a surface water supply must be site specific in order to account for variations in soil moisture holding capacity, watershed area supplying the runoff, climatic conditions, and proposed irrigation management procedures. With the use of farm specific simulation models to determine grain yields, availability of irrigation water, and economic expenditures involved in irrigation, an economic evaluation of supplemental irrigation can be performed, In the model presented in this report, the Duncan SIMAIZ model is used to predict grain yields using long-term daily weather information. SIMAIZ also determines irrigation water demand for the crop. The Haan Water Yield Model is used to predict flow into a reservoir using the same weather information. By knowing daily water flow into a reservoir and water demand for irrigation, a reservoir size is determined which will supply water at all times for the study period. Simulations are then run by incrementally reducing, by volume, the size of this reservoir, thus limiting the availability of irrigation water, and resulting in reduced irrigated yields. An economic evaluation is performed for each reservoir size. Costs and benefits included are: initial cost of constructing the reservoir, yearly reservoir maintenance cost, yearly irrigation costs of operation, and additional income resulting from the increase in grain yields. After the project life has been assumed, the model determines the capital available for investing in an irrigation system for a given year and reservoir size. By ranking these values, a probability distribution is obtained indicating the probability of making money in any given year. By using the Central Limit Theorem, these results are converted to the probability of making money over the life of the system. A sensitivity analysis examines the sensitivity of capital available for investment in an irrigation system to select input variation. The results indicate that great care should be exercised when assigning values to some inputs, while for others, a reasonable estimate is adequate. This model can be used as a tool for evaluating which irrigation practices, if any, are economically feasible. An example of its use is shown

More Than One Personal Risk Factor is Associated with Worse Clinical Outcomes Among Adolescents Following Concussion

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Attenuated and Protease-Profile Modified Sendai Virus Vectors as a New Tool for Virotherapy of Solid Tumors

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Influence of solvent granularity on the effective interaction between charged colloidal suspensions

We study the effect of solvent granularity on the effective force between two charged colloidal particles by computer simulations of the primitive model of strongly asymmetric electrolytes with an explicitly added hard sphere solvent. Apart from molecular oscillating forces for nearly touching colloids which arise from solvent and counterion layering, the counterions are attracted towards the colloidal surfaces by solvent depletion providing a simple statistical description of hydration. This, in turn, has an important influence on the effective forces for larger distances which are considerably reduced as compared to the prediction based on the primitive model. When these forces are repulsive, the long-distance behaviour can be described by an effective Yukawa pair potential with a solvent-renormalized charge. As a function of colloidal volume fraction and added salt concentration, this solvent-renormalized charge behaves qualitatively similar to that obtained via the Poisson-Boltzmann cell model but there are quantitative differences. For divalent counterions and nano-sized colloids, on the other hand, the hydration may lead to overscreened colloids with mutual attraction while the primitive model yields repulsive forces. All these new effects can be accounted for through a solvent-averaged primitive model (SPM) which is obtained from the full model by integrating out the solvent degrees of freedom. The SPM was used to access larger colloidal particles without simulating the solvent explicitly.Comment: 14 pages, 16 craphic

The Secret to Successful User Communities: An Analysis of Computer Associates’ User Groups

This paper provides the first large scale study that examines the impact of both individual- and group-specific factors on the benefits users obtain from their user communities. By empirically analysing 924 survey responses from individuals in 161 Computer Associates' user groups, this paper aims to identify the determinants of successful user communities. To measure success, the amount of time individual members save through having access to their user networks is used. As firms can significantly profit from successful user communities, this study proposes four key implications of the empirical results for the management of user communities

Situating Speech: A Rhetorical Approach to Political Strategy

Ideas are increasingly acknowledged as factors in explaining political behaviour. But often they are treated as inert resources rather than dynamic instances of action in themselves. The latter, I propose, requires reflection on the character of speech – as the medium of ideas – in responding to and refiguring a prevailing situation. I undertake such reflection by setting out a rhetorical approach to political strategy. Building upon ‘interpretive’ advances in political science I shift the focus from stable cognitive frames to the dynamics of argumentation where ideas work expressively. I then explore the rhetorical aspect of strategising with attention to the way speech serves to orient audiences by creatively re-appropriating a situation. That approach is shown to be consistent with a ‘dialectical’ political sociology that emphasises the interaction of structure and agency. Finally, I sketch a method for undertaking rhetorical analysis and indicate how it might be applied to a concrete example

Target and reality of adjuvant endocrine therapy in postmenopausal patients with invasive breast cancer

Previous research evaluating the use of adjuvant endocrine therapy among postmenopausal breast cancer patients showed with 15–50% wide ranges of non-adherence rates. We evaluated this issue by analysing an unselected study group comprising of 325 postmenopausal women, diagnosed from 1997 to 2003 with hormonal receptor-positive invasive breast cancer. The different clinical situations that led to the discontinuation of adjuvant endocrine therapy were clearly defined and differentiated: non-adherence was not simply the act of stopping medication, but rather the manifestation of an intentional behaviour of the patient. Of the 287 patients who initiated endocrine therapy, 191 (66.6%) fully completed this treatment. Thirty-one patients (10.8%) showed non-adherence to therapy. Patients who had follow-up with a general practitioner, rather than in an oncologic unit, were more likely to be non-adherent (P=0.0088). Of 25 patients who changed medication due to therapy-related adverse effects, 20 (80%) patients fully completed the therapy after drug change. In adjuvant endocrine therapy, a lowering of the non-adherence rate to 10.8%, the lowest reported in the literature, is realistic when patients are cared for by a specialised oncologic unit focusing on the individual needs of the patients

Bethe-hole polarization analyser for the magnetic vector of light

The nature of light as an electromagnetic wave with transverse components has been confirmed using optical polarizers, which are sensitive to the orientation of the electric field. Recent advances in nanoscale optical technologies demand their magnetic counterpart, which can sense the orientation of the optical magnetic field. Here we report that subwavelength metallic apertures on infinite plane predominantly sense the magnetic field of light, establishing the orientation of the magnetic component of light as a separate entity from its electric counterpart. A subwavelength aperture combined with a tapered optical fibre probe can also serve as a nanoscale polarization analyser for the optical magnetic field, analogous to a nanoparticle sensing the local electric polarization. As proof of its functionality, we demonstrate the measurement of a magnetic field orientation that is parallel to the electric field, as well as a circularly polarized magnetic field in the presence of a linearly polarized electric field

Capturing Desire: Rhetorical Strategies and the Affectivity of Discourse

In this article I argue that psychoanalytical theory can help us understand the emotional force of political rhetoric. I undertake a theoretical enquiry into the method of interpreting political speeches as strategies of affective persuasion. Both rhetorical and psychoanalytical studies converge in their concern with the production of ‘plausible stories’ that aim to fold psychic investments into political judgements. To capture desire, I claim, political rhetoric must articulate ‘symptomatic beliefs’ in relation to wider situational exigencies. I sketch three distinct psychoanalytical approaches, each of which emphasises a different scenario of unconscious organisation where rhetorical strategies are pertinent: namely Freudian, Kleinian, and Lacanian approaches. These are then applied to the example of a controversial rhetorical intervention – Enoch Powell’s infamous Birmingham speech of 1968 – to demonstrate the various potential focii when undertaking analysis