1,193 research outputs found

    Characterization of vegetation by microwave and optical remote sensing

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    Two series of carefully controlled experiments were conducted. First, plots of important crops (corn, soybeans, and sorghum), prairie grasses (big bluestem, switchgrass, tal fescue, orchardgrass, bromegrass), and forage legumes (alfalfa, red clover, and crown vetch) were manipulated to produce wide ranges of phytomass, leaf area index, and canopy architecture. Second, coniferous forest canopies were simulated using small balsam fir trees grown in large pots of soil and arranged systematically on a large (5 m) platform. Rotating the platform produced many new canopies for frequency and spatial averaging of the backscatter signal. In both series of experiments, backscatter of 5.0 GHz (C-Band) was measured as a function of view angle and polarization. Biophysical measurements included leaf area index, fresh and dry phytomass, water content of canopy elements, canopy height, and soil roughness and moisture content. For a subset of the above plots, additional measurements were acquired to exercise microwave backscatter models. These measurements included size and shape of leaves, stems, and fruit and the probability density function of leaf and stem angles. The relationships of the backscattering coefficients and the biophysical properties of the canopies were evaluated using statistical correlations, analysis of variance, and regression analysis. Results from the corn density and balsam fir experiments are discussed and analyses of data from the other experiments are summarized

    Soybean canopy reflectance modeling data sets

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    Numerous mathematical models of the interaction of radiation with vegetation canopies have been developed over the last two decades. However, data with which to exercise and validate these models are scarce. During three days in the summer of 1980, experiments are conducted with the objective of gaining insight about the effects of solar illumination and view angles on soybean canopy reflectance. In concert with these experiment, extensive measurements of the soybean canopies are obtained. This document is a compilation of the bidirectional reflectance factors, agronomic, characteristics, canopy geometry, and leaf, stem, and pod optical properties of the soybean canopies. These data sets should be suitable for use with most vegetation canopy reflectance models

    Schools and civil society : corporate or community governance

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    School improvement depends upon mediating the cultural conditions of learning as young people journey between their parochial worlds and the public world of cosmopolitan society. Governing bodies have a crucial role in including or diminishing the representation of different cultural traditions and in enabling or frustrating the expression of voice and deliberation of differences whose resolution is central to the mediation of and responsiveness to learning needs. A recent study of governing bodies in England and Wales argues that the trend to corporatising school governance will diminish the capacity of schools to learn how they can understand cultural traditions and accommodate them in their curricula and teaching strategies. A democratic, stakeholder model remains crucial to the effective practice of governing schools. By deliberating and reconciling social and cultural differences, governance constitutes the practices for mediating particular and cosmopolitan worlds and thus the conditions for engaging young people in their learning, as well as in the preparation for citizenship in civil society

    Some Effects of Oxygen Concentration on Levels of Respiratory Intermediates in Buckwheat Seedlings

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    Encountering Multiple Exemplars During Fast Mapping Facilitates Word Learning

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    Abstract Previous research indicates learning words facilitates categorization. In the current study, we investigated whether learning about a category facilitates word learning (retention) by presenting 2-year-old children with multiple referent selection trials to the same object category. Children either encountered the same exemplar repeatedly or encountered multiple exemplars across trials. All children did very well on the initial task. However, only children who encountered multiple exemplars retained these mappings after a short delay. Overall, these data provide strong evidence that providing children with the opportunity to compare across exemplars during referent selection facilitates retention

    Preclinical Evaluation of Novel All-in-one Formulations of 5-Fluorouracil and Folinic Acid with Reduced Toxicity Profiles - Supplementary Data

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    Objectives: 5-Fluorouracil (5-FU) in combination with its synergistic biomodulator folinic acid maintains a pivotal position in cancer chemotherapy. However, clinical limitations persist with the administration of these drugs in combination including phlebitis and catheter blockages, which are associated with reduced efficacy and/or quality of life for patients. We have previously reported novel all-in-one, pH neutral, parenteral 5-FU and folinic acid formulations (termed Fluorodex) incorporating beta-cyclodextrins. Fluorodex maintains potency while overcoming the accepted incompatibility of 5-FU and folinic acid.Methods: We performed toxicological, pharmacokinetic and biodistribution, and efficacy evaluations of Fluorodex compared to 5-FU:folinic acid using several administration routes and schedules in two rodent models. These were compared to dose-matched sequential administration of 5-FU:folinic acid.Results: Fluorodex showed bioequivalence to 5-FU:folinic acid as assessed by tissue distribution and pharmacokinetics of 5-FU, but was generally better tolerated as determined by weight loss, hematological and other clinical parameters. Compared to 5-FU:folinic acid, Fluorodex was also associated with reduced phlebitis using a rabbit ear vein model. Furthermore, equivalent to enhanced efficacy of Fluorodex compared to 5-FU:folinic acid against human carcinoma tumour models in mice was observed.Conclusions: These novel all-in-one formulations represent a superior injectable form of 5- FU that allows co-delivery of folinic acid. This should translate to improved patient tolerability with potential for enhanced efficacy

    Fludarabine phosphate for the treatment of low grade lymphoid malignancy.

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    Thirty-four patients with previously treated, advanced, low grade NHL were treated with Fludarabine, a deamination-resistant analogue of adenosine arabinoside, at a dose of 25 mg m-2 intravenously, daily for 5 days (median number of cycles = 3, range 1-10). Complete remission (CR) was achieved in six and partial remission (PR) in a further seven. Overall, responses were seen in 11/23 patients (48%) with follicular lymphoma and in 2/11 (18%) with low grade, diffuse NHL. Fifteen patients with previously treated CLL and one patient with prolymphocytic leukaemia (PLL) were also treated as above (median no. of cycles = 3, range 1-6). A partial response was seen in three of the 11 evaluable patients with CLL and CR was achieved in the patient with PLL. There were four deaths due to infection and 19 further episodes requiring admission to hospital. No other significant toxicity was reported in a total of 164 cycles of Fludarabine. This agent is active in advanced low grade lymphoid malignancy. Further studies are required to assess its role in newly diagnosed patients

    Insights from agriculture for the management of insecticide resistance in disease vectors

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    Key to contemporary management of diseases such as malaria, dengue, and filariasis is control of the insect vectors responsible for transmission. Insecticide-based interventions have contributed to declines in disease burdens in many areas, but this progress could be threatened by the emergence of insecticide resistance in vector populations. Insecticide resistance is likewise a major concern in agriculture, where insect pests can cause substantial yield losses. Here, we explore overlaps between understanding and managing insecticide resistance in agriculture and in public health. We have used the Global Plan for Insecticide Resistance Management in malaria vectors, developed under the auspices of the World Health Organization Global Malaria Program, as a framework for this exploration because it serves as one of the few cohesive documents for managing a global insecticide resistance crisis. Generally, this comparison highlights some fundamental differences between insect control in agriculture and in public health. Moreover, we emphasize that the success of insecticide resistance management strategies is strongly dependent on the biological specifics of each system. We suggest that the biological, operational, and regulatory differences between agriculture and public health limit the wholesale transfer of knowledge and practices from one system to the other. Nonetheless, there are some valuable insights from agriculture that could assist in advancing the existing Global Plan for Insecticide Resistance Management framework
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