Influence of commercial formulation on the sorption and leaching behaviour of propyzamide in soil

Experiments compared sorption and leaching behaviour for the herbicide propyzamide when applied to two soils either as technical material or in the commercial formulation Kerb® Flo. Sorption was investigated in batch systems as well as using a centrifugation technique to investigate changes in pesticide concentration in soil pore water over incubation periods of up to 28 days. Studies with small soil columns compared leaching of technical and formulated pesticide for irrigation events (6 pore volumes) 1, 7, 14, 21 and 28 days after treatment. There were no differences in sorption of technical and formulated propyzamide when measured by batch systems. Sorption of technical material was significantly greater than that of formulated pesticide in sandy loam (p<0.05), but not in sandy silt loam when measured by centrifugation of soil incubated at field capacity. Partition coefficients measured by batch and centrifugation methods were similar after 1 day and those measured by centrifugation increased by factors of 5.3 to 7.5 over the next 4 weeks. The mass of propyzamide leached from soil columns ranged between 1.1±0.33% and 14.4±3.2% of the applied amount. For all time intervals and in both soils, the mass of propyzamide leached was significantly greater (two-sided t-tests, p<0.001) for the formulated product than for the technical material. Leached losses decreased consistently with time in the sandy loam soil (losses after 28 days were 14-17% of those after 1 day), but with less consistency in the sandy silt loam. There was a highly significant effect of formulation on the leaching of propyzamide through soil (two-way ANOVA, p<0.001) as well as highly significant effects of time and soil type (p<0.001). Results are consistent with modelling studies where leaching from commercial products in the field could only be simulated by reducing sorption coefficients relative to those measured with technical material in the laboratory

Meta-Reflexivity and Teacher Professionalism: Facilitating Multiparadigmatic Teacher Education to Achieve a Future-Proof Profession

The present work discusses the relevance of meta-reflexivity, both for the professionalization of the teaching profession and for teacher education. Meta-reflexivity is based on the multiparadigmatic system of teacher education, which finds itself grounded in diverse scientific disciplines. The approach takes uncertainty as an essential element characterizing the act of teaching. Inherent rationales of specific theories and empirical findings are made explicit, thus creating a referential framework for situation-specific interpretations and professional action. Based on a theoretical reconstruction, we propose meta-reflexivity as an essential element of pedagogic practice and, consequently, teacher professionalism. Such professionalism is characterized by teachers being able to undertake exemplary-typifying interpretations of situations, based on a deep understanding of multiple approaches. While assessing specific situations in school, a teacher can refer to these interpretations. Possible principles of a meta-reflexive teacher education are proposed that can potentially enrich the practice of teacher education for a future-proof profession

A modelling framework to simulate river flow and pesticide loss via preferential flow at the catchment scale

A modelling framework with field-scale models including the preferential flow model MACRO was developed to simulate transport of six contrasting herbicides in a 650 km2 catchment in eastern England. The catchment scale model SPIDER was also used for comparison. The catchment system was successfully simulated as the sum of multiple field-scale processes with little impact of in-stream processes on simulations. Preferential flow was predicted to be the main driver of pesticide transport in the catchment. A satisfactory simulation of the flow was achieved (Nash-Sutcliffe model efficiencies of 0.56 and 0.34 for MACRO and SPIDER, respectively) but differences between pesticide simulations were observed due to uncertainties in pesticide properties and application details. Uncertainty analyses were carried out to assess input parameters reported as sensitive including pesticide sorption, degradation and application dates; their impact on simulations was chemical-specific. The simulation of pesticide concentrations in the river during low flow periods was very sensitive to uncertainty from rain gauge measurements and the estimation of evapotranspiration

Modelling triazines in the valley of the River Cauca, Colombia, using the annualized agricultural non-point source pollution model

The annualized agricultural non-point source pollution model (AnnAGNPS) was applied to simulate losses of triazine herbicides to the River Cauca following application to sugarcane, maize and sorghum in the Cauca Valley of Colombia. Surface runoff was found to be the main driver of triazine losses to surface water in the catchment. Satisfactory simulation and validation of the hydrology was achieved after little calibration (Nash-Sutcliffe model efficiency = 0.70 and r2 = 0.73). A fairly good simulation of pesticides was generally achieved, but some patterns in the measured data could not be simulated. Uncertainty analyses of sensitive input parameters were carried out which explained most of the concentrations that were not captured by the initial simulation; however, evidence of point source pollution was observed for some large concentrations measured upstream. Replacing triazine herbicides with mesotrione was predicted to result in an 87% reduction in pesticide losses expressed as a proportion of the total pesticide applied

A rich structure related to the construction of holomorphic matrix functions

PhD ThesisThe problem of designing controllers that are robust with respect to uncertainty leads to questions that are in the areas of operator theory and several complex variables. One direction is the engineering problem of -synthesis, which has led to the study of certain inhomogeneous domains such as the symmetrised polydisc and the tetrablock. The - synthesis problem involves the construction of holomorphic matrix valued functions on the disc, subject to interpolation conditions and a boundedness condition. In more detail, let 1; : : : ; n be distinct points in the disc, and let W1; : : : ;Wn be 2 2 matrices. The -synthesis problem related to the symmetrised bidisc involves nding a holomorphic 2 2 matrix function F on the disc such that F( j) = Wj for all j, and the spectral radius of F( ) is less than or equal to 1 for all in the disc. The -synthesis problem related to the tetrablock involves nding a holomorphic 2 2 matrix function F on the disc such that F( j) = Wj for all j, and the structured singular value (for the diagonal matrices with entries in C) of F( ) is less than or equal to 1 for all in the disc. For the symmetrised bidisc and for the tetrablock, we study the structure of interconnections between the matricial Schur class, the Schur class of the bidisc, the set of pairs of positive kernels on the bidisc subject to a boundedness condition, and the set of holomorphic functions from the disc into the given inhomogeneous domain. We use the theory of reproducing kernels and Hilbert function spaces in these connections. We give a solvability criterion for the interpolation problem that arises from the -synthesis problem related to the tetrablock. Our strategy for this problem is the following: (i) reduce the -synthesis problem to an interpolation problem in the set of holomorphic functions from the disc into the tetrablock; (ii) induce a duality between this set and the Schur class of the bidisc; and then (iii) use Hilbert space models for this Schur class to obtain necessary and su cient conditions for solvability

Rationale and design of the Clinical Evaluation of Magnetic Resonance Imaging in Coronary heart disease 2 trial (CE-MARC 2): a prospective, multicenter, randomized trial of diagnostic strategies in suspected coronary heart disease

Background: A number of investigative strategies exist for the diagnosis of coronary heart disease (CHD). Despite the widespread availability of noninvasive imaging, invasive angiography is commonly used early in the diagnostic pathway. Consequently, approximately 60% of angiograms reveal no evidence of obstructive coronary disease. Reducing unnecessary angiography has potential financial savings and avoids exposing the patient to unnecessary risk. There are no large-scale comparative effectiveness trials of the different diagnostic strategies recommended in international guidelines and none that have evaluated the safety and efficacy of cardiovascular magnetic resonance.&lt;p&gt;&lt;/p&gt; Trial Design: CE-MARC 2 is a prospective, multicenter, 3-arm parallel group, randomized controlled trial of patients with suspected CHD (pretest likelihood 10%-90%) requiring further investigation. A total of 1,200 patients will be randomized on a 2:2:1 basis to receive 3.0-T cardiovascular magnetic resonance–guided care, single-photon emission computed tomography–guided care (according to American College of Cardiology/American Heart Association appropriate-use criteria), or National Institute for Health and Care Excellence guidelines–based management. The primary (efficacy) end point is the occurrence of unnecessary angiography as defined by a normal (&#62;0.8) invasive fractional flow reserve. Safety of each strategy will be assessed by 3-year major adverse cardiovascular event rates. Cost-effectiveness and health-related quality-of-life measures will be performed.&lt;p&gt;&lt;/p&gt; Conclusions: The CE-MARC 2 trial will provide comparative efficacy and safety evidence for 3 different strategies of investigating patients with suspected CHD, with the intension of reducing unnecessary invasive angiography rates. Evaluation of these management strategies has the potential to improve patient care, health-related quality of life, and the cost-effectiveness of CHD investigation

Prediction Of Pest Pressure on Corn Root Nodes – The POPP-Corn model

A model for the corn rootworm Diabrotica spp. (Coleoptera: Chrysomelidae) combined with a temporally-explicit model for development of corn roots across the soil profile was developed to link pest ecology, root damage and yield loss. Development of the POPP-Corn model focused on simulating root damage from rootworm feeding in accordance with empirical observations in the field to allow the virtual testing of efficacy from management interventions in the future. Here we present the model and demonstrate its applicability for simulating root damage by comparison between observed and simulated pest population development and root damage (assessed according to the node injury scale from 0 to 3) for field studies from the literature conducted in Urbana, Illinois (US) between 1991 and 2014. The model simulated the first appearance of larvae and adults to within a week of that observed in 88 and 71% of all years, respectively, and in all cases to within two weeks of the first sightings recorded for central Illinois. Furthermore, in 73% of all years simulated root damage differed by less than 0.5 node injury scale points compared to the observations made in the field between 2005 and 2014 even though accurate information for initial pest pressure (i.e., number of eggs in the soil) was not measured at the sites or available from nearby locations. This is, to our knowledge, the first time that pest ecology, root damage and yield loss have been successfully interlinked to produce a virtual field. There are potential applications in investigating efficacy of different pest control measures and strategies

A knowledge-based approach to designing control strategies for agricultural pests

Chemical control of insect pests remains vital to agricultural productivity, but limited mechanistic understanding of the interactions between crop, pest and chemical control agent have restricted our capacity to respond to challenges such as the emergence of resistance and demands for tighter environmental regulation. Formulating effective control strategies that integrate chemical and non-chemical management for soil-dwelling pests is particularly problematic owing to the complexity of the soil-root-pest system and the variability that occurs between sites and between seasons. Here, we present a new concept, termed COMPASS, that integrates ecological knowledge on pest development and behaviour together with crop physiology and mechanistic understanding of chemical distribution and toxic action within the rhizosphere. The concept is tested using a two-dimensional systems model (COMPASS-Rootworm) that simulates root damage in maize from the corn rootworm Diabrotica spp. We evaluate COMPASS-Rootworm using 119 field trials that investigated the efficacy of insecticidal products and placement strategies at four sites in the USA over a period of ten years. Simulated root damage is consistent with measurements for 109 field trials. Moreover, we disentangle factors influencing root damage and pest control, including pest pressure, weather, insecticide distribution, and temporality between the emergence of crop roots and pests. The model can inform integrated pest management, optimize pest control strategies to reduce environmental burdens from pesticides, and improve the efficiency of insecticide development

Simple and objective prediction of survival in patients with lung cancer: staging the host systemic inflammatory response

Background. Prediction of survival in patients diagnosed with lung cancer remains problematical. The aim of the present study was to examine the clinical utility of an established objective marker of the systemic inflammatory response, the Glasgow Prognostic Score, as the basis of risk stratification in patients with lung cancer. Methods. Between 2005 and 2008 all newly diagnosed lung cancer patients coming through the multidisciplinary meetings (MDTs) of four Scottish centres were included in the study. The details of 882 patients with a confirmed new diagnosis of any subtype or stage of lung cancer were collected prospectively. Results. The median survival was 5.6 months (IQR 4.8–6.5). Survival analysis was undertaken in three separate groups based on mGPS score. In the mGPS 0 group the most highly predictive factors were performance status, weight loss, stage of NSCLC, and palliative treatment offered. In the mGPS 1 group performance status, stage of NSCLC, and radical treatment offered were significant. In the mGPS 2 group only performance status and weight loss were statistically significant. Discussion. This present study confirms previous work supporting the use of mGPS in predicting cancer survival; however, it goes further by showing how it might be used to provide more objective risk stratification in patients diagnosed with lung cancer