Enhancing Online Learning: Design Principles for More Effective Educational Web Forums

Online educational web forums are increasingly being used in tertiary education settings to either supplement or replace face-to-face teacher-learner interactions. However, much use of such forums tends to be ad-hoc and ineffective which invariably results in dismal learner participation levels. This paper will report on a particular research inquiry into the design principles of a more effective and strategic use of educational web forums within particular coursework contexts and in relation to a range of possible learning outcomes. It will therefore focus especially on the design challenge of two issues in particular. The first is the inherent communication limitations as well as opportunities represented by typical web forum functions. A second related issue lies in the challenge of reconciling in practice both participant-related factors and course-design related factors. Participant-related factors include personal profiles, prior learning experiences and educational perspectives. Conversely course-design related factors include the quality and quantity of assessment items, the communication of unit requirements and the underlying approach to learning and facilitation of the unit. In this way the paper will explore how a more strategic negotiation of the intrinsic and extrinsic factors of coursework participation can be a design basis for more effective online learning and active learner participation

Fluorogenic Membrane Overlays to Enumerate Total and Fecal Escherichia coli and Total Vibrionaceae in Shellfish and Seawater

Three assays were developed to enumerate total and fecal Escherichia coli and total Vibrionaceae in shellfish, seawater, and other foods and environmental samples. Assays involve membrane overlays of overnight colonies on nonselective agar plates to detect β-glucuronidase and lysyl aminopeptidase activities for E. coli and Vibrionaceae, respectively. Cellulose membranes containing the substrates 4-methylumbeferyl-β-D-glucuronide (MUG) produced a bright blue fluorescence when overlaid onto E. coli, while L-lysyl-7-amino-4-trifluoromethylcoumarin produced green fluorescent foci when overlaid onto Vibrionaceae family members. A multiplex assay was also developed for simultaneously enumerating total E. coli and total Vibrionaceae in oysters and seawater. Overall, 65% of overlaid E. coli (non-O157:H7) were MUG-positive, compared with 62% as determined by the most-probable-number-MUG assay. The overlays are rapid, simple, and cost effective for quantification purposes. This research provides practical alternatives for monitoring bacterial indicators and potential pathogens in complex samples, including molluscan shellfish

The effect of cattle slurry in combination with nitrate and the nitrification inhibitor dicyandiamide on in situ nitrous oxide and dinitrogen emissions

peer-reviewedA field study was conducted to determine the effect of the nitrification inhibitor dicyandiamide (DCD) on N2O and N2 emissions after cattle slurry (CS) application in the presence of nitrate (NO3) fertiliser on seven different occasions (between March 2009 and March 2011). N2O emissions from CS in the presence of NO3 fertiliser were very high (0.4–8.7% of applied N) over a 20-day period, under mild moist conditions. Emissions were significantly larger from the CS treatment compared to an NH4+-N source, supplying the same rate of N as in the slurry. This study supports the view that organic fertilisers should not be applied at the same time as nitrate-based fertilisers, as significant increases in N2O emissions occur. The average N2O mole fraction (N2O/(N2O + N2)) over all seven application dates was 0.34 for CSNO3 compared to 0.24 for the NH4ClNO3 treatment, indicating the dominance of N2 emissions. The rate of nitrification in CSNO3 was slower than in NH4ClNO3, and DCD was found to be an effective nitrification inhibitor in both treatments. However, as N2O emissions were found to be predominantly associated with the NO3 pool, the effect of DCD in lowering N2O emissions is limited in the presence of a NO3 fertiliser. To obtain the maximum cost-benefit of DCD in lowering N2O emissions, under mild moist conditions, it should not be applied to a nitrate containing fertiliser (e.g. ammonium nitrate or calcium ammonium nitrate), and therefore the application of DCD should be restricted to ammonium-based organic or synthetic fertilisers.This research was funded by the Irish National Development Plan, through the Research Stimulus Fund (RSF 07 519), administered by the Irish Department of Agriculture, Food and the Marine

Improving and disaggregating N2O emission factors for ruminant excreta on temperate pasture soils

pre-printCattle excreta deposited on grazed grasslands are a major source of the greenhouse gas (GHG) nitrous oxide (N2O). Currently, many countries use the IPCC default emission factor (EF) of 2% to estimate excreta-derived N2O emissions. However, emissions can vary greatly depending on the type of excreta (dung or urine), soil type and timing of application. Therefore three experiments were conducted to quantify excreta-derived N2O emissions and their associated EFs, and to assess the effect of soil type, season of application and type of excreta on the magnitude of losses. Cattle dung, urine and artificial urine treatments were applied in spring, summer and autumn to three temperate grassland sites with varying soil and weather conditions. Nitrous oxide emissions were measured from the three experiments over 12 months to generate annual N2O emission factors. The EFs from urine treated soil was greater (0.30–4.81% for real urine and 0.13–3.82% for synthetic urine) when compared with dung (− 0.02–1.48%) treatments. Nitrous oxide emissions were driven by environmental conditions and could be predicted by rainfall and temperature before, and soil moisture deficit after application; highlighting the potential for a decision support tool to reduce N2O emissions by modifying grazing management based on these parameters. Emission factors varied seasonally with the highest EFs in autumn and were also dependent on soil type, with the lowest EFs observed from well-drained and the highest from imperfectly drained soil. The EFs averaged 0.31 and 1.18% for cattle dung and urine, respectively, both of which were considerably lower than the IPCC default value of 2%. These results support both lowering and disaggregating EFs by excreta type.This research was financially supported under the National Development Plan, through the Research Stimulus Fund, administered by the Department of Agriculture, Food and the Marine (Grant numbers RSF10/RD/SC/716 and 11S138)

Hierarchical case-based reasoning to support knitwear design

Knitwear design is a creative activity that is hard to automate using the computer. The production of the associated knitting pattern, however, is repetitive, time-consuming and error-prone, calling for automation. Our objectives are two-fold: to facilitate the design and to ease the burden of calculations and checks in pattern production. We conduct a feasibility study for applying case-based reasoning in knitwear design: we describe appropriate methods and show their application

Structure and Service Delivery Approach of the Children’s Bureau’s Resource Centers and Implementation Centers

The Children’s Bureau (CB) provides a system of training and technical assistance (T/TA) to build the capacity of state and tribal child welfare systems, with the goal of improving outcomes for children and families. During the time period of 2008-2014, this infrastructure included ten National Child Welfare Resource Centers (NRCs), five Child Welfare Implementation Centers (ICs), and a Training and Technical Assistance Coordination Center (TTACC). Individual ICs and NRCs differed in structure and content expertise, yet they served the same jurisdictions and at times provided services concurrently. To increase cohesion and consistency, the NRCs, ICs, TTACC, and CB worked together to develop a service delivery approach for delivering T/TA services. This approach encompassed an overall vision of T/TA that promoted individualized, coordinated, and evidence-informed services. Operationalization of the model incorporated a standardized business process for responding to T/TA requests. This included a Standard Assessment Tool that supported identifying the desired outcomes of services and assessing the jurisdiction’s ability to make use of the T/TA by considering elements of readiness for organizational change. CB also encouraged the NRCs and ICs to apply concepts from research on leadership and implementation to their services; these frameworks supported involvement of stakeholders in the assessment process and throughout T/TA delivery. Three examples illustrate how T/TA consistent with this service delivery approach were provided to one tribal nation and two states

Predicting a process window for the roll-to-roll deposition of solvent-engineered SnO2 in perovskite solar cells

Lightweight flexible perovskite solar cells (PSCs) offer advantages over rigid solar cells including power to weight, variety of form factor and ability to scale. With breakthroughs in the power conversion efficiency (PCE) of PSCs, scaling up PSCs with similar performance has become a topic of interest. Roll-to-roll (R2R) manufacturing is one promising method to leverage the low temperature processing ability of PSCs. In this work, we demonstrate the R2R slot-die coating of the SnO2 electron transport layer, applying the low flow limit to showcase its pertinence in assessing the coating window for slot-die coating. It was observed that low flow limit can accurately predict the processing window for solvent-engineered SnO2 solutions streamlining scale up from benchtop to full R2R coating. We achieved a PCE of 16.35% for R2R-coated SnO2-based MAPbI3 perovskite devices exceeding the performance of benchtop-coated devices

Genetic Assimilation and Canalisation in the Baldwin Effect

The Baldwin Effect indicates that individually learned behaviours acquired during an organism’s lifetime can influence the evolutionary path taken by a population, without any direct Lamarckian transfer of traits from phenotype to genotype. Several computational studies modelling this effect have included complications that restrict its applicability. Here we present a simplified model that is used to reveal the essential mechanisms and highlight several conceptual issues that have not been clearly defined in prior literature. In particular, we suggest that canalisation and genetic assimilation, often conflated in previous studies, are separate concepts and the former is actually not required for non-heritable phenotypic variation to guide genetic variation. Additionally, learning, often considered to be essential for the Baldwin Effect, can be replaced with a more general phenotypic plasticity model. These simplifications potentially permit the Baldwin Effect to operate in much more general circumstances

Gas phase RDX decomposition pathways using coupled cluster theory

Electronic and free energy barriers for a series of gas-phase RDX decomposition mechanisms have been obtain using coupled cluster singles, doubles, and perturbative triples with complete basis set (CCSD(T)/CBS) electronic energies for MBPT(2)/cc-pVTZ structures. Importantly, we have located a well-defined transition state for NN homolysis, in the initial RDX decomposition step, thereby obtaining a true barrier for this reaction. These calculations support the view that HONO elimination is preferred at STP over other proposed mechanisms, including NN homolysis, “triple whammy” and NONO isomerization. Indeed, our calculated values of Arrhenius parameters are in agreement with experimental findings for gas phase RDX decomposition. We also investigate a number of new pathways leading to breakdown of the intermediate formed by the initial HONO elimination, and find that NN homolysis in this intermediate has an activation energy barrier comparable with that computed for HONO elimination

Confirmation of co-denitrification in grazed grassland

peer-reviewedPasture-based livestock systems are often associated with losses of reactive forms of nitrogen (N) to the environment. Research has focused on losses to air and water due to the health, economic and environmental impacts of reactive N. Di-nitrogen (N2) emissions are still poorly characterized, both in terms of the processes involved and their magnitude, due to financial and methodological constraints. Relatively few studies have focused on quantifying N2 losses in vivo and fewer still have examined the relative contribution of the different N2 emission processes, particularly in grazed pastures. We used a combination of a high 15N isotopic enrichment of applied N with a high precision of determination of 15N isotopic enrichment by isotope-ratio mass spectrometry to measure N2 emissions in the field. We report that 55.8 g N m−2 (95%, CI 38 to 77 g m−2) was emitted as N2 by the process of co-denitrification in pastoral soils over 123 days following urine deposition (100 g N m−2), compared to only 1.1 g N m−2 (0.4 to 2.8 g m−2) from denitrification. This study provides strong evidence for co-denitrification as a major N2 production pathway, which has significant implications for understanding the N budgets of pastoral ecosystems.The authors are grateful for the funding that was provided through the Research Stimulus Fund Program administered by the Department of Agriculture & Food under the National Development Plan 2007–2013 RSF 07536. The first author is grateful for the funding provided by Teagasc through the Walsh Fellowship Scheme