706 research outputs found
Towards sustainability in South Africa : a study of local government sustainability planning in the Cape Metropolitan Area
Includes bibliography.The popular use of the term sustainability represents a consensus around the fact that society must change its path towards ecological destruction and the consequent decline in human's quality of life. Sustainability facilitates the integration of environmental issues, previously seen as radical and disruptive, into mainstream political, social and economic discourse. The term therefore represents a transitional tool which will lead society from its current non-sustainable phase to greater sustainability. At present the most successful action for change is being initiated from the local level through local sustainability planning. Sustainability planning represents an alternative approach to local government decision-making based on the principles of sustainability. Many countries are experiencing success with local sustainability planning initiatives such as Healthy Cities and Local Agenda 21. These initiatives represent generic approaches to sustainability planning. This thesis contends that a more successful approach could be gained through tailoring strategic planning to local contexts. The challenge is to design a framework that meets the needs of the specific socio-economic, legislative and institutional contexts of a given area. South Africa's discriminatory socio-political history has resulted in major social and environmental legacies, especially amongst the marginalised and poor sectors of society. These legacies must be understood and addressed in order to carry-out successful sustainability planning processes. Since 1994 sustainability in South Africa has received significant attention in the legislation which has emanated from the democratic government. The legal framework for sustainability is provided by a progressive Constitution [Act 108 of 1996]. The Constitution provides clear objectives for environmental management. Furthering the framework for environmental management set out in the Constitution is the National Environmental Management Act [Act 107 of 1998] (NEMA). NEMA is a key piece of legislation which has far-reaching implications for sustainability. It establishes general principles which act as a framework within which environmental management in the country will be carried out. The Constitution [Act 108 of 1996] also sets out clear objectives for local governance. Local government in the CMA, as in the rest of South Africa, is suffering from the effects of the (re)current restructuring period following the country's transition to democracy. This sphere of government is experiencing significant financial and capacity constraints. The situation has been compounded by a lack of civil-sector consultation during this protracted period of change. Mechanisms for addressing sustainability and incorporating environmental issues within local government planning and decision-making are absent from national legislation. Local government sustainability planning represents such a mechanism. This study researches the current status and future prospects for local government sustainability planning using the Cape Metropolitan Area (CMA) in South Africa as a case study. A framework for local government sustainability planning is developed based on the current national and local contexts. The proposed framework places the fundamental principles of sustainability at the highest strategic level in the authority. Alongside these principles are key operational themes of sustainability. Each of these should be used to guide and inform decisions and activities carried out within the local government authority. As we enter the new millennium local government in South Africa has an increasing responsibility to achieve local sustainability and in so doing to elevate its citizens quality of life. A bold response to local sustainability planning is required if this is to be achieved
Hyperspectral measurements of yellow rust and fusarium head blight in cereal crops: Part 1: Laboratory study
This paper assesses the potential use of a hyperspectral camera for measurement of yellow rust and fusarium head blight in wheat and barley canopy under laboratory conditions. Scanning of crop canopy in trays occurred between anthesis growth stage 60, and hard dough growth stage 87. Visual assessment was made at four levels, namely, at the head, at the flag leaves, at 2nd and 3rd leaves, and at the lower canopy. Partial least squares regression (PLSR) analyses were implemented separately on data captured at four growing stages to establish separate calibration models to predict the percentage coverage of yellow rust and fusarium head blight infection. Results showed that the standard deviation between 500 and 650 nm and the squared difference between 650 and 700 nm wavelengths were found to be significantly different between healthy and infected canopy particularly for yellow rust in both crops, whereas the effect of water-stress was generally found to be unimportant. The PLSR yellow rust models were of good prediction capability for 6 out of 8 growing stages, a very good prediction at early milk stage in wheat and a moderate prediction at the late milk development stage in barley. For fusarium, predictions were very good for seven growing stages and of good performance for anthesis growing stage in wheat, with best performing for the milk development stages. However, the root mean square error of predictions for yellow rust were almost half of those for fusarium, suggesting higher prediction accuracies for yellow rust measurement under laboratory conditions
Resolving the identification of weak-flying insects during flight: a coupling between rigorous data processing and biology
1. Bioacoustic methods play an increasingly important role for the detection of insects in a range of surveillance and monitoring programs.
2. Weak-flying insects evade detection because they do not yield sufficient audio information to capture wingbeat and harmonic frequencies. These inaudible insects often pose a significant threat to food security as pests of key agricultural crops worldwide.
3. Automatic detection of such insects is crucial to the future of crop protection by providing critical information to assess the risk to a crop and the need for preventative measures.
4. We describe an experimental setup designed to derive audio recordings from a range of weak-flying aphids and beetles using an LED array.
5. A rigorous data processing pipeline was developed to extract meaningful features, linked to morphological characteristics, from the audio and harmonic series for six aphid and two beetle species.
6. An ensemble of over 50 bioacoustic parameters was used to achieve species discrimination with a success rate of 80%. The inclusion of the dominant and fundamental frequencies improved prediction between beetles and aphids due to large differences in wingbeat frequencies.
7. At the species level, error rates were minimised when harmonic features were supplemented by features indicative of differences in species’ flight energies
Institutional and technological barriers to the use of open educational resources (OERs) in physiology and medical education
Open educational resources (OERs) are becoming increasingly common as a tool in education, particularly in medical and biomedical education. However, three key barriers have been identified to their use: (i) lack of awareness of OERs, (ii) lack of motivation to use OERs, and (iii) lack of training in the use of OERs. Here, we explore these three barriers with teachers of medical and biomedical science to establish how best to enhance the use of OERs to improve pedagogical outcomes. An online survey was completed by 209 educators, many of whom (68.4%) reported using OERs in their teaching, and almost all (99.5%) showing awareness of at least one OER. Results suggest that key problems that prevent educators from adopting OERs in their teaching include suitability for particular classes, time, and copyright. Most (81.8%) educators were somewhat, very, or extremely comfortable with OERs so there is no innate motivational barrier to adoption. A lack of training was reported by 13.9% of respondents, and 40% of respondents stated that there was little or no support from their institutions. OER users were no more comfortable with technology or better supported by departments, but tended to be aware of a greater number of sources of OERs. Our study illustrates key opportunities for the expansion of OER use in physiology and medical teaching: increased breadth of awareness, increased institutional support (including time, training, and copyright support), and greater sharing of diverse OERs to suit the range of teaching challenges faced by staff in different subdisciplines
Spectral soil analysis for fertilizer recommendations by coupling with QUEFTS for maize in East Africa: A sensitivity analysis
Laboratory analysis of soil properties is prohibitively expensive and difficult to scale across the soils in sub Saharan Africa. This results in a lack of soil-specific fertilizer recommendations, where recommendation can only be provided at a regional scale. This study aims to assess the feasibility of using spectral soil analysis to provide soil-specific fertilizer recommendations. Using a range of spectrometers [NeoSpectra Saucer (NIR), FieldSpec 4 (vis-NIR) with contact probe or mug light interface, FTIR Bruker Tensor 27 (MIR)], 346 archived soil samples (0–20 cm) with known soil chemical properties collected from Ethiopia, Kenya and Tanzania were scanned. Partial least square regression (PLSR) was used to develop prediction models for selected soil properties including pH, soil organic carbon (SOC), total nitrogen, Olsen P, and exchangeable K. These predicted properties, and associated uncertainty, were used to derive fertilizer recommendations for maize using the Quantitative Evaluation of the Fertility of Tropical Soils (QUEFTS) model parameters for sub-Saharan Africa. Most soil properties (pH, SOC, total nitrogen, and exchangeable K) were well predicted (Concordance Correlation Coefficient values between 0.88 and 0.96 and Ratio of Performance to Interquartile values between 1.4 and 5.9) by all the spectrometers but there were performance variations between soil properties and spec-
trometers. Use of the predicted soil data for the development of fertilizer recommendations gave promising results when compared to the recommendations obtained with the conventional soil analysis. For example, the least performing NeoSpectra Saucer over/under-estimated up to 8 and 24 kg ha-1N and P, respectively, though there was insignificant variation in estimation of P fertilizer among spectrometers. We conclude that spectral technology can be used to determine major soil properties with satisfactory precision, sufficient for specific fertilizer decision making in East Africa, possibly even with portable equipment in the fiel
Uncovering Trait Associations Resulting in Maximal Seed Yield in Winter and Spring Oilseed Rape
Seed yield is a complex trait for many crop species including oilseed rape (OSR) (Brassica napus), the second most important oilseed crop worldwide. Studies have focused on the contribution of distinct factors in seed yield such as environmental cues, agronomical practices, growth conditions, or specific phenotypic traits at the whole plant level, such as number of pods in a plant. However, how female reproductive traits contribute to whole plant level traits, and hence to seed yield, has been largely ignored. Here, we describe the combined contribution of 33 phenotypic traits within a B. napus diversity set population and their trade-offs at the whole plant and organ level, along with their interaction with plant level traits. Our results revealed that both Winter OSR (WOSR) and Spring OSR (SOSR); the two more economically important OSR groups in terms of oil production; share a common dominant reproductive strategy for seed yield. In this strategy, the main inflorescence is the principal source of seed yield, producing a good number of ovules, a large number of long pods with a concomitantly high number of seeds per pod. Moreover, we observed that WOSR opted for additional reproductive strategies than SOSR, presenting more plasticity to maximise seed yield. Overall, we conclude that OSR adopts a key strategy to ensure maximal seed yield and propose an ideal ideotype highlighting crucial phenotypic traits that could be potential targets for breeding
Beyond the one-way ANOVA for 'omics data
Background: With ever increasing accessibility to high throughput technologies, more complex treatment structures can be assessed in a variety of 'omics applications. This adds an extra layer of complexity to the analysis and interpretation, in particular when inferential univariate methods are applied en masse. It is well-known that mass univariate testing suffers from multiplicity issues and although this has been well documented for simple comparative tests,few approaches have focussed on more complex explanatory structures.
Results: Two frameworks are introduced incorporating corrections for multiplicity whilst maintaining appropriate structure in the explanatory variables. Within this paradigm, a choice has to be made as to whether multiplicity corrections should be applied to the saturated model, putting emphasis on controlling the rate of false positives, or to the predictive model, where emphasis is on model selection.
This choice has implications for both the ranking and selection of the response variables identified as differentially expressed. The theoretical difference is demonstrated between the two approaches along with an empirical study of lipid composition in Arabidopsis under differing levels of salt stress.
Conclusions: Multiplicity corrections have an inherent weakness when the full explanatory structure is not properly incorporated. Although a unifying `single best' recommendation is not provided, two reasonable alternatives are provided and the applicability of these approaches is discussed for different scenarios where the aims of analysis will differ. The key result is that the point at which multiplicity is incorporated into the analysis will fundamentally change the interpretation of the results, and the choice of approach should therefore be driven by the specific aims of the experiment
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Species matter when considering landscape effects on carabid distributions
Increasing the abundance and diversity of carabid beetles is a common objective of farm habitat management to deliver sustainable pest control. Carabid spatial distributions in relation to crop areas are important to the delivery of this ecosystem service.
We used pitfall count data at distances from edge habitats into crop centres, from farm sites across the UK, to determine the effects of in-field and adjacent environmental features on carabid abundance and diversity.
Overall carabid abundance increased towards the crop centre, whilst species richness and diversity decreased. The analyses of carabid abundance based on all the species pooled together strongly reflected the behaviour of the most abundant species. Species preferences varied by crop, soil type, and environmental features. For instance, some species were positively associated with habitats such as margins, while others responded negatively. This contrast in individual species models highlights the limitations on pooled models in elucidating responses.
Studies informing farm-habitat design should consider individual species’ preferences for effective enhancement of pest control services. Diverse cropping and landscape heterogeneity at the farm scale can benefit the varied preferences of individual species, help build diverse communities and, potentially increase service resilience and stability over time
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