Use-oriented courseware development for agricultural education : an ecological approach

This thesis investigates the disappointing use of computers and courseware in Dutch agricultural education. The central question is: How to develop courseware that will be used by teachers in agricultural education practice? On the basis of a theoretical frame of reference and by means of two case studies, the use of courseware in the context of Dutch agricultural education is described, understood and explained; and use influencing factors are established. Prescriptions are formulated that reckon with these factors and presumably increase the likelihood of use in practice. In two additional case studies, both the process and the organisation of courseware development for Dutch agricultural education are described, understood and explained. On the basis of this understanding, the prescriptions, phrased in the two preceding case studies, are adjusted and extended. The resulting prescriptions fit into five categories:a) courseware should address needsb) courseware should lead to lower costs of usec) courseware development should match teacher learningd) courseware development should reckon with contexts of usee) courseware development should be organised in manner that facilitates useincreasing developmentEssentially, the formulation of these use-increasing prescriptions as described above amounts to tailoring the courseware-development process to the context in which the courseware will be used. For this process of tailoring, insight is needed in the contingencies between courseware- development characteristics and the attributes of a context of use. These contingencies are described in the last chapter of this thesis. Risk prevention is the most important argument in selecting a specific courseware-development characteristic for a given context.In this research, this tailoring process is applied to Dutch agricultural education. The resulting alternative and supposedly use-increasing approach of courseware development can be characterised as situation specific, teacher-driven, and processoriented. Important domains of expertise are those of subject matter, of teachers as users, of project and educational innovation management and of instructional design. This approach combines a small scale with a high level of ambition. This approach is termed ecological since insights from ecology offer instructive analogies that for courseware development can be phrased as follows. Courseware may offer a wide range of educational improvements, the contexts of use determine the quality characteristics of viable courseware applications. Consequently, characterising, a viable courseware application implies describing its context of use

The anearobic digestion of organic matter in sugar-beet mud

Storage of sugar-beet mud in the traditional way, i.e., direct dewatering after pumping the slurry in storage basins, may cause odor nuisance because of digestion of organic substances. In order to prevent these bad odor problems the mud should remain submerged during the digestion period. No production of malodorous compounds was observed in this way, also not when after 1 yr of submersion the basins were dewatered and the mud began to ripen. Experiments were performed with small mud fields, barrels and pots in order to gain insight in the anaerobic digestion processes and to develop methods to optimize these. During these experiments the mud was subjected to a number of different treatments. No essential difference exists between the digestion process in dewatered and submerged mud. The digestion rate of the produced volatile fatty acids (VFA) depends on the growth rate of the bacteria responsible for the conversion of VFA into CH4 and CO2. This growth rate seems to be controlled in the pot experiment by the amount of available NH4-N. Treatment of the mud, for instance inoculation with old ripened mud or addition of carbonates, is only successful when the environmental conditions in the mud are very unfavorable for methane production (high VFA concentrations and low pH)

Ventricular function and biomarkers in relation to repair and pulmonary valve replacement for tetralogy of Fallot

Objective Cardiac surgery may cause temporarily impaired ventricular performance and myocardial injury. We aim to characterise the response to perioperative injury for patients undergoing repair or pulmonary valve replacement (PVR) for tetralogy of Fallot (ToF). Methods We enrolled children undergoing ToF repair or PVR from four tertiary centres in a prospective observational study. Assessment - including blood sampling and speckle tracking echocardiography - occurred before surgery (T1), at the first follow-up (T2) and 1 year after the procedures (T3). Ninety-two serum biomarkers were expressed as principal components to reduce multiple statistical testing. RNA Sequencing was performed on right ventricular (RV) outflow tract samples. Results We included 45 patients with ToF repair aged 4.3 (3.4 - 6.5) months and 16 patients with PVR aged 10.4 (7.8 - 12.7) years. Ventricular function following ToF repair showed a fall-and-rise pattern for left ventricular global longitudinal strain (GLS) (-18±4 to -13±4 to -20±2, p &lt; 0.001 for each comparison) and RV GLS (-19±5 to -14±4 to 20±4, p &lt; 0.002 for each comparison). This pattern was not seen for patients undergoing PVR. Serum biomarkers were expressed as three principal components. These phenotypes are related to: (1) surgery type, (2) uncorrected ToF and (3) early postoperative status. Principal component 3 scores were increased at T2. This increase was higher for ToF repair than PVR. The transcriptomes of RV outflow tract tissue are related to patients' sex, rather than ToF-related phenotypes in a subset of the study population. Conclusions The response to perioperative injury following ToF repair and PVR is characterised by specific functional and immunological responses. However, we did not identify factors relating to (dis)advantageous recovery from perioperative injury. Trial registration number Netherlands Trial Register: NL5129.</p

Cardiac Function and Serum Biomarkers throughout Staged Fontan Palliation:A Prospective Observational Study

Fontan patients undergo multiple cardiothoracic surgeries in childhood. Following these procedures, ventricular function is temporarily decreased, and recovers over months. This is presumably related to cardiopulmonary bypass, but this is incompletely understood. Throughout the Fontan palliation, cardiac function is also affected by volume unloading. We aimed to gain insight into the biological processes related to impaired ventricular function and recovery following Fontan palliations using a panel of biomarkers. Furthermore, we described changes in ventricular function across the Fontan palliation due to volume unloading. We performed a prospective multicenter observational study in patients undergoing partial (PCPC) or total cavo-pulmonary connection (TCPC). Patients underwent assessment-including echocardiography and blood sampling-before surgery (T1), at first follow-up (T2), and 1 year after their procedures (T3). Blood samples were analyzed using a biomarker panel (OLINK CVD-III). Ninety-two biomarkers were expressed as principal components (PC) to limit multiple statistical testing. We included 32 PCPC patients aged 7.2 [5.3-10.3] months, and 28 TCPC patients aged 2.7 [2.2-3.8] years. The single ventricular longitudinal strain (SV GLS) temporarily decreased for PCPC patients at T2 (-15.1 ± 5.6 (T1) to -13.5 ± 5.2 (T2) to -17.3 ± 4.5 (T3), p &lt; 0.047 for all differences), but not following TCPC. The serum biomarkers were expressed as 4 PCs. PC1, including biomarkers of cell-cell adhesion, was not related to any patient characteristic. PC2, including biomarkers of superoxide anion regulation, increased at T2. PC3, including biomarkers of cardiovascular development, related to the stage of Fontan palliation. PC4 was of uncertain biological or clinical significance. No PC was found that related to ventricular performance. The SV GLS was temporarily diminished following PCPC, but not following TCPC. Several biomarkers were related to post-operative stress and adaptation to the PCPC or TCPC circulation, but none were related to the outcome. </p

Cardiac Function and Serum Biomarkers throughout Staged Fontan Palliation:A Prospective Observational Study

Fontan patients undergo multiple cardiothoracic surgeries in childhood. Following these procedures, ventricular function is temporarily decreased, and recovers over months. This is presumably related to cardiopulmonary bypass, but this is incompletely understood. Throughout the Fontan palliation, cardiac function is also affected by volume unloading. We aimed to gain insight into the biological processes related to impaired ventricular function and recovery following Fontan palliations using a panel of biomarkers. Furthermore, we described changes in ventricular function across the Fontan palliation due to volume unloading. We performed a prospective multicenter observational study in patients undergoing partial (PCPC) or total cavo-pulmonary connection (TCPC). Patients underwent assessment—including echocardiography and blood sampling—before surgery (T1), at first follow-up (T2), and 1 year after their procedures (T3). Blood samples were analyzed using a biomarker panel (OLINK CVD-III). Ninety-two biomarkers were expressed as principal components (PC) to limit multiple statistical testing. We included 32 PCPC patients aged 7.2 [5.3–10.3] months, and 28 TCPC patients aged 2.7 [2.2–3.8] years. The single ventricular longitudinal strain (SV GLS) temporarily decreased for PCPC patients at T2 (−15.1 ± 5.6 (T1) to −13.5 ± 5.2 (T2) to −17.3 ± 4.5 (T3), p &lt; 0.047 for all differences), but not following TCPC. The serum biomarkers were expressed as 4 PCs. PC1, including biomarkers of cell–cell adhesion, was not related to any patient characteristic. PC2, including biomarkers of superoxide anion regulation, increased at T2. PC3, including biomarkers of cardiovascular development, related to the stage of Fontan palliation. PC4 was of uncertain biological or clinical significance. No PC was found that related to ventricular performance. The SV GLS was temporarily diminished following PCPC, but not following TCPC. Several biomarkers were related to post-operative stress and adaptation to the PCPC or TCPC circulation, but none were related to the outcome.</p

Cardiac Function and Serum Biomarkers throughout Staged Fontan Palliation: A Prospective Observational Study

Fontan patients undergo multiple cardiothoracic surgeries in childhood. Following these procedures, ventricular function is temporarily decreased, and recovers over months. This is presumably related to cardiopulmonary bypass, but this is incompletely understood. Throughout the Fontan palliation, cardiac function is also affected by volume unloading. We aimed to gain insight into the biological processes related to impaired ventricular function and recovery following Fontan palliations using a panel of biomarkers. Furthermore, we described changes in ventricular function across the Fontan palliation due to volume unloading. We performed a prospective multicenter observational study in patients undergoing partial (PCPC) or total cavo-pulmonary connection (TCPC). Patients underwent assessment—including echocardiography and blood sampling—before surgery (T1), at first follow-up (T2), and 1 year after their procedures (T3). Blood samples were analyzed using a biomarker panel (OLINK CVD-III). Ninety-two biomarkers were expressed as principal components (PC) to limit multiple statistical testing. We included 32 PCPC patients aged 7.2 [5.3–10.3] months, and 28 TCPC patients aged 2.7 [2.2–3.8] years. The single ventricular longitudinal strain (SV GLS) temporarily decreased for PCPC patients at T2 (−15.1 ± 5.6 (T1) to −13.5 ± 5.2 (T2) to −17.3 ± 4.5 (T3), p < 0.047 for all differences), but not following TCPC. The serum biomarkers were expressed as 4 PCs. PC1, including biomarkers of cell–cell adhesion, was not related to any patient characteristic. PC2, including biomarkers of superoxide anion regulation, increased at T2. PC3, including biomarkers of cardiovascular development, related to the stage of Fontan palliation. PC4 was of uncertain biological or clinical significance. No PC was found that related to ventricular performance. The SV GLS was temporarily diminished following PCPC, but not following TCPC. Several biomarkers were related to post-operative stress and adaptation to the PCPC or TCPC circulation, but none were related to the outcome

Predicting outcome in children with dilated cardiomyopathy: the use of repeated measurements of risk factors for outcome

Aims: We aimed to determine whether in children with dilated cardiomyopathy repeated measurement of known risk factors for death or heart transplantation (HTx) during disease progression can identify children at the highest risk for adverse outcome. Methods and results: Of 137 children we included in a prospective cohort, 36 (26%) reached the study endpoint (SE: all-cause death or HTx), 15 (11%) died at a median of 0.09 years [inter-quartile range (IQR) 0.03–0.7] after diagnosis, and 21 (15%) underwent HTx at a median of 2.9 years [IQR 0.8–6.1] after diagnosis. Median follow-up was 2.1 years [IQR 0.8–4.3]. Twenty-three children recovered at a median of 0.6 years [IQR 0.5–1.4] after diagnosis, and 78 children had ongoing disease at the end of the study. Children who reached the SE could be distinguished from those who did not, based on the temporal evolution of four risk factors: stunting of length growth (−0.42 vs. −0.02 length Z-score per year, P < 0.001), less decrease in N-terminal pro-B-type natriu