318 resultados para Shifting cultivation
Resumo:
Physical and chemical properties of biodiesel are influenced by structural features of the fatty acids, such as chain length, degree of unsaturation and branching of the carbon chain. This study investigated if microalgal fatty acid profiles are suitable for biodiesel characterization and species selection through Preference Ranking Organisation Method for Enrichment Evaluation (PROMETHEE) and Graphical Analysis for Interactive Assistance (GAIA) analysis. Fatty acid methyl ester (FAME) profiles were used to calculate the likely key chemical and physical properties of the biodiesel [cetane number (CN), iodine value (IV), cold filter plugging point, density, kinematic viscosity, higher heating value] of nine microalgal species (this study) and twelve species from the literature, selected for their suitability for cultivation in subtropical climates. An equal-parameter weighted (PROMETHEE-GAIA) ranked Nannochloropsis oculata, Extubocellulus sp. and Biddulphia sp. highest; the only species meeting the EN14214 and ASTM D6751-02 biodiesel standards, except for the double bond limit in the EN14214. Chlorella vulgaris outranked N. oculata when the twelve microalgae were included. Culture growth phase (stationary) and, to a lesser extent, nutrient provision affected CN and IV values of N. oculata due to lower eicosapentaenoic acid (EPA) contents. Application of a polyunsaturated fatty acid (PUFA) weighting to saturation led to a lower ranking of species exceeding the double bond EN14214 thresholds. In summary, CN, IV, C18:3 and double bond limits were the strongest drivers in equal biodiesel parameter-weighted PROMETHEE analysis.
Resumo:
Daylight devices are important components of any climate responsive façade system. But, the evolution of parametric CAD systems and digital fabrication has had an impact on architectural form so that regular forms are shifting to complex geometries. Architectural and engineering integration of daylight devices in envelopes with complex geometries is a challenge in terms of design and performance evaluation. The purpose of this paper is to assess daylight performance of a building with a climatic responsive envelope with complex geometry that integrates shading devices in the façade. The case study is based on the Esplanade buildings in Singapore. Climate-based day-light metrics such as Daylight Availability and Useful Daylight Illuminance are used. DIVA (daylight simulation), and Grasshopper (parametric analysis) plug-ins for Rhinoceros have been employed to examine the range of performance possibilities. Parameters such as dimension, inclination of the device, projected shadows and shape have been changed in order to maximize daylight availability and Useful Daylight Illuminance while minimizing glare probability. While orientation did not have a great impact on the results, aperture of the shading devices did, showing that shading devices with a projection of 1.75 m to 2.00 m performed best, achieving target lighting levels without issues of glare.
Predicting invasion in grassland ecosystems: is exotic dominance the real embarrassment of richness?
Resumo:
Invasions have increased the size of regional species pools, but are typically assumed to reduce native diversity. However, global-scale tests of this assumption have been elusive because of the focus on exotic species richness, rather than relative abundance. This is problematic because low invader richness can indicate invasion resistance by the native community or, alternatively, dominance by a single exotic species. Here, we used a globally replicated study to quantify relationships between exotic richness and abundance in grass-dominated ecosystems in 13 countries on six continents, ranging from salt marshes to alpine tundra. We tested effects of human land use, native community diversity, herbivore pressure, and nutrient limitation on exotic plant dominance. Despite its widespread use, exotic richness was a poor proxy for exotic dominance at low exotic richness, because sites that contained few exotic species ranged from relatively pristine (low exotic richness and cover) to almost completely exotic-dominated ones (low exotic richness but high exotic cover). Both exotic cover and richness were predicted by native plant diversity (native grass richness) and land use (distance to cultivation). Although climate was important for predicting both exotic cover and richness, climatic factors predicting cover (precipitation variability) differed from those predicting richness (maximum temperature and mean temperature in the wettest quarter). Herbivory and nutrient limitation did not predict exotic richness or cover. Exotic dominance was greatest in areas with low native grass richness at the site- or regional-scale. Although this could reflect native grass displacement, a lack of biotic resistance is a more likely explanation, given that grasses comprise the most aggressive invaders. These findings underscore the need to move beyond richness as a surrogate for the extent of invasion, because this metric confounds monodominance with invasion resistance. Monitoring species' relative abundance will more rapidly advance our understanding of invasions.
Resumo:
More evenly spread demand for public transport throughout a day can reduce transit service provider‟s total asset and labour costs. A plausible peak spreading strategy is to increase peak fare and/or to reduce off-peak fare. This paper reviews relevant empirical studies for urban rail systems, as rail transit plays a key role in Australian urban passenger transport and experiences severe peak loading variability. The literature is categorised into four groups: a) passenger opinions on willingness to change time for travel, b) valuations of displacement time using stated preference technique, c) simulations of peak spreading based on trip scheduling models, and: d) real-world cases of peak spreading using differential fare. Policy prescription is advised to take into account impacts of traveller‟s time flexibility and joint effects of mode shifting and peak spreading. Although focusing on urban rail, arguments in this paper are relevant to public transport in general with values to researchers and practitioners.
Resumo:
Rice ragged stunt virus (RRSV) is an important pathogen of rice affecting its cultivation in South and South East Asia. An approach based on pathogen derived resistance (PDR) was used to produce RRSV resistant rice cultivars. Sequences from the coding region of RRSV genome segments 7 and 10 (non-structural genes), and 5, 8 and 9 (structural genes) were placed in sense or antisense orientation behind the plant expression promoters CaMV35S, RolC, Ubil, Actl and RBTV. Rice cultivars Taipei 309 and Chinsurah Boro II were transformed by biolistic and/or Agrobacterium-mediated delivery of one or more of these PDR gene constructs. A large number of transgenic lines were produced from calli derived from mature or immature embryos, co-bombarded with the marker gene hph encoding hygromycin resistance and RRSV PDR genes or co-cultivated with strains having the binary vector containing these two genes. Both Mendelian and non-Mendelian segregations were observed in transgenic progeny, especially with transgenic lines produced by biolistics. Preliminary tests conducted in China on selected transgenic lines indicate that plants with RRSV segment 5 antisense PDR gene confer RRSV resistance.
Resumo:
Sundarbans, a Ramsar and World Heritage site, is the largest single block of tidal halophytic mangrove forest in the world covering parts of Bangladesh and India. Natural mangroves were very common along the entire coast of Bangladesh. However, all other natural mangrove forests, including the Chakaria Sundarbans with 21,000 hectares of mangrove, have been cleared for shrimp cultivation. Against this backdrop, the Forest Department of Bangladesh has developed project design documents for a project called ‘Collaborative REDD+ Improved Forest Management (IFM) Sundarbans Project’ (CRISP) to save the only remaining natural mangrove forest of the country. This project, involving conservation of 412,000 ha of natural mangrove forests, is expected to generate, over a 30-year period, a total emissions reduction of about 6.4 million tons of CO2. However, the successful implementation of this project involves a number of critical legal and institutional issues. It may involve complex legal issues such as forest ownership, forest use rights, rights of local people and carbon rights. It may also involve institutional reforms. Ensuring good governance of the proposed project is very vital considering the failure of the Asian Development Bank (ADB) funded and Bangladesh Forest Department managed ‘Sundarbans Biodiversity Conservation Project’. Considering this previous experience, this paper suggests that a comprehensive legal and institutional review and reform is needed for the successful implementation of the proposed CRISP project. This paper argues that without ensuring local people’s rights and their participation, no project can be successful in the Sundarbans. Moreover, corruption of local and international officials may be a serious hurdle in the successful implementation of the project.
Resumo:
Over the last two decades, particularly in Australia and the UK, the doctoral landscape has changed considerably with increasingly hybridised approaches to methodologies and research strategies as well as greater choice of examinable outputs. This paper provides an overview of doctoral practices that are emerging in the creative industries context, from a predominantly Australian perspective, with a focus on practice-led approaches within the Doctor of Philosophy and recent developments in professional doctorates. The paper examines some of the diverse theoretical principles which foreground the practitioner/researcher, methodological approaches that incorporate tacit knowledge and reflective practice together with qualitative strategies, blended learning delivery modes, and flexible doctoral outputs;and how these are shaping this shifting environment towards greater research-based industry outputs. The discussion is based around a single extended case study of the Doctor of Creative Industries at Queensland University of Technology (QUT) as one model of an interdisciplinary professional research doctorate.
Resumo:
It has been well established that highlighting the cultural attributes of a region through stories of place, local histories, and the creative arts boosts tourism income to a region. Cultural tourism also serves to promote the creative industries to visitors and residents alike and, by enhancing a region’s cultural identity, fosters new opportunities for the arts. It can therefore offer considerable potential benefit to the creative economy in Australia. However, in comparison with Europe, where cultural tourism can rely upon an established historical, artistic and literary cultural identity that stretches back to Grand Tours of the seventeenth century, in Queensland, Australia the relatively new enterprise of cultural tourism must compete with visitor expectations of sun, surf and the natural landscapes, which have become the mainstay of tourism advertising. Moreover, in Queensland, it is essential to connect vast distances, diverse communities and a variety of cultural experiences. We must also take account of the expectations of contemporary tourists, who anticipate a digitally mediated travel experience and increasingly seek to connect with local communities in authentic ways. In this paper we consider the unique considerations that must be taken into account in the Queensland context and propose approaches to developing an integrated identity that embraces both the ‘great outdoors’ and the region’s cultural attributes. We make recommendations for providing the types of digitally mediated ‘local’ experiences that cultural tourists now expect, and illustrate the design principles we propose through early, tentative approaches to smart phones, locative media and augmented reality applications for cultural tourism in the region. We conclude by proposing additional ways to formulate a digital strategy in line with the recommendations we make.
Resumo:
Between the 1890s and 1920s street trees became a more prominent feature in streetscapes across New South Wales, Australia. The Sydney Botanic Gardens, with their extensive nursery system, were responsible for supplying seedlings to councils and municipalities for use as street trees. As such, this institution was a primary mover of what a street tree should be, how they should be used and what plants were best suited to this particular use in urban environments. This paper analyses the nurturing of this use of street trees by the Sydney Botanic Gardens and the Director Joseph Maiden. This institution was a place that moved not just stock and seedlings, but ideas about how nature's inclusion into urban environments had the capacity to influence and enhance the cultivation of civilised citizens. This was affected through access to transnational resources available to the Sydney Botanic Gardens.
Resumo:
A multi-resource multi-stage scheduling methodology is developed to solve short-term open-pit mine production scheduling problems as a generic multi-resource multi-stage scheduling problem. It is modelled using essential characteristics of short-term mining production operations such as drilling, sampling, blasting and excavating under the capacity constraints of mining equipment at each processing stage. Based on an extended disjunctive graph model, a shifting-bottleneck-procedure algorithm is enhanced and applied to obtain feasible short-term open-pit mine production schedules and near-optimal solutions. The proposed methodology and its solution quality are verified and validated using a real mining case study.
Resumo:
Talk of Big Data seems to be everywhere. Indeed, the apparently value-free concept of ‘data’ has seen a spectacular broadening of popular interest, shifting from the dry terminology of labcoat-wearing scientists to the buzzword du jour of marketers. In the business world, data is increasingly framed as an economic asset of critical importance, a commodity on a par with scarce natural resources (Backaitis, 2012; Rotella, 2012). It is social media that has most visibly brought the Big Data moment to media and communication studies, and beyond it, to the social sciences and humanities. Social media data is one of the most important areas of the rapidly growing data market (Manovich, 2012; Steele, 2011). Massive valuations are attached to companies that directly collect and profit from social media data, such as Facebook and Twitter, as well as to resellers and analytics companies like Gnip and DataSift. The expectation attached to the business models of these companies is that their privileged access to data and the resulting valuable insights into the minds of consumers and voters will make them irreplaceable in the future. Analysts and consultants argue that advanced statistical techniques will allow the detection of ongoing communicative events (natural disasters, political uprisings) and the reliable prediction of future ones (electoral choices, consumption)...
Resumo:
Emerging infectious diseases present a complex challenge to public health officials and governments; these challenges have been compounded by rapidly shifting patterns of human behaviour and globalisation. The increase in emerging infectious diseases has led to calls for new technologies and approaches for detection, tracking, reporting, and response. Internet-based surveillance systems offer a novel and developing means of monitoring conditions of public health concern, including emerging infectious diseases. We review studies that have exploited internet use and search trends to monitor two such diseases: influenza and dengue. Internet-based surveillance systems have good congruence with traditional surveillance approaches. Additionally, internet-based approaches are logistically and economically appealing. However, they do not have the capacity to replace traditional surveillance systems; they should not be viewed as an alternative, but rather an extension. Future research should focus on using data generated through internet-based surveillance and response systems to bolster the capacity of traditional surveillance systems for emerging infectious diseases.
Resumo:
This paper takes a multimethod approach which combines ethnographic techniques and discourse studies to investigate two contrasting professional groups: community photographers, who are favela dwellers who have developed photographic projects in Brazil‘s favelas, and photojournalists of the mainstream media. Its purpose is to determine how a cultural and social divide in the city of Rio de Janeiro shapes both community photographers and mainstream photojournalists’ practices, discourses, and identities. While community photographers strive to establish a humane and positive view about favelas and their residents by shifting the focus from poverty, shortages, violence, and criminality to images of the ordinary life, mainstream photojournalists express the view that their role is of primary importance for the defence of human rights in the favelas by helping to prevent, for instance, police abuses and violations. As the data analysis indicated the existence of socio-spatial borders all over Rio de Janeiro, this study adopted the idea of a divided city without denying interconnections between favelas and the city’s political life. Through the analysis of categories which emerged from the data, the complex world of documenting favela life is explored. The major themes touched upon are: the breakdown between the mainstream media and the favela communities; the different kinds of relationships which arise in Rio’s low income suburbs; and the gradual return of mainstream news workers to favelas.
Resumo:
In recent decades, the governance of food safety, food quality, on-farm environmental management and animal welfare has been shifting from the realm of 'the government' to that of the private sector. Corporate entities, especially the large supermarkets, have responded to neoliberal forms of governance and the resultant 'hollowed-out' state by instituting private standards for food, backed by processes of certification and policed through systems of third party auditing. Today's food regime is one in which supermarkets impose 'private standards' along the food supply chain to ensure compliance with a range of food safety goals-often above and beyond those prescribed by government. By examining regulatory governance in Australia, Norway and the United Kingdom we highlight emerging trajectories of food governance. We argue that the imposition of the new private forms of monitoring and compliance continue the project of agricultural restructuring that began with government support for structural adjustment schemes in agriculture and that these are most evident in the UK and Australia where neoliberalism is an entrenched philosophy. However, despite Norway's identity as a social democracy, we also identify neoliberal 'creep' into the system of food governance. Small-scale producers in all three nations are finding themselves increasingly subject to governance through private, market-based mechanisms that, to varying degrees, are dominated by major supermarket chains. The result is agricultural restructuring not through the traditional avenues of elected governments, but via non-elected market operatives.
Resumo:
Flows of cultural heritage in textual practices are vital to sustaining Indigenous communities. Indigenous heritage, whether passed on by oral tradition or ubiquitous social media, can be seen as a “conversation between the past and the future” (Fairclough, 2012, xv). Indigenous heritage involves appropriating memories within a cultural flow to pass on a spiritual legacy. This presentation reports ethnographic research of social media practices in a small independent Aboriginal school in Southeast Queensland, Australia that is resided over by the Yugambeh elders and an Aboriginal principal. The purpose was to rupture existing notions of white literacies in schools, and to deterritorialize the uses of digital media by dominant cultures in the public sphere. Examples of learning experiences included the following: i. Integrating Indigenous language and knowledge into media text production; ii. Using conversations with Indigenous elders and material artifacts as an entry point for storytelling; iii. Dadirri – spiritual listening in the yarning circle to develop storytelling (Ungunmerr-Baumann, 2002); and iv. Writing and publicly sharing oral histories through digital scrapbooking shared via social media. The program aligned with the Australian National Curriculum English (ACARA, 2012), which mandates the teaching of multimodal text creation. Data sources included a class set of digital scrapbooks collaboratively created in a multi-age primary classroom. The digital scrapbooks combined digitally encoded words, images of material artifacts, and digital music files. A key feature of the writing and digital design task was to retell and digitally display and archive a cultural narrative of significance to the Indigenous Australian community and its memories and material traces of the past for the future. Data analysis of the students’ digital stories involved the application of key themes of negotiated, material, and digitally mediated forms of heritage practice. It drew on Australian Indigenous research by Keddie et al. (2013) to guard against the homogenizing of culture that can arise from a focus on a static view of culture. The interpretation of findings located Indigenous appropriation of social media within broader racialized politics that enables Indigenous literacy to be understood as a dynamic, negotiated, and transgenerational flows of practice. The findings demonstrate that Indigenous children’s use of media production reflects “shifting and negotiated identities” in response to changing media environments that can function to sustain Indigenous cultural heritages (Appadurai, 1696, xv). It demonstrated how the children’s experiences of culture are layered over time, as successive generations inherit, interweave, and hear others’ cultural stories or maps. It also demonstrated how the children’s production of narratives through multimedia can provide a platform for the flow and reconstruction of performative collective memories and “lived traces of a common past” (Giaccardi, 2012). It disrupts notions of cultural reductionism and racial incommensurability that fix and homogenize Indigenous practices within and against a dominant White norm. Recommendations are provided for an approach to appropriating social media in schools that explicitly attends to the dynamic nature of Indigenous practices, negotiated through intercultural constructions and flows, and opening space for a critical anti-racist approach to multimodal text production.