990 resultados para Scientific discourses


Relevância:

20.00% 20.00%

Publicador:

Resumo:

To investigate the effects of the middle atmosphere on climate, the World Climate Research Programme is supporting the project "Stratospheric Processes and their Role in Climate" (SPARC). A central theme of SPARC, to examine model simulations of the coupled troposphere—middle atmosphere system, is being performed through the initiative called GRIPS (GCM—Reality Intercomparison Project for SPARC). In this paper, an overview of the objectives of GRIPS is given. Initial activities include an assessment of the performance of middle atmosphere climate models, and preliminary results from this evaluation are presented here. It is shown that although all 13 models evaluated represent most major features of the mean atmospheric state, there are deficiencies in the magnitude and location of the features, which cannot easily be traced to the formulation (resolution or the parameterizations included) of the models. Most models show a cold bias in all locations, apart from the tropical tropopause region where they can be either too warm or too cold. The strengths and locations of the major jets are often misrepresented in the models. Looking at three—dimensional fields reveals, for some models, more severe deficiencies in the magnitude and positioning of the dominant structures (such as the Aleutian high in the stratosphere), although undersampling might explain some of these differences from observations. All the models have shortcomings in their simulations of the present—day climate, which might limit the accuracy of predictions of the climate response to ozone change and other anomalous forcing.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Jean-François Lyotard's 1973 essay ‘Acinema’ is explicitly concerned with the cinematic medium, but has received scant critical attention. Lyotard's acinema conceives of an experimental, excessive form of film-making that uses stillness and movement to shift away from the orderly process of meaning-making within mainstream cinema. What motivates this present paper is a striking link between Lyotard's writing and contemporary Hollywood production; both are concerned with a sense of excess, especially within moments of motion. Using Charlie's Angels (McG, 2000) as a case study – a film that has been critically dismissed as ‘eye candy for the blind’ – my methodology brings together two different discourses, high culture theory and mainstream film-making, to test out and propose the value of Lyotard's ideas for the study of contemporary film. Combining close textual analysis and engagement with key scholarship on film spectacle, I reflexively engage with the process of film analysis and re-direct attention to a neglected essay by a major theorist, in order to stimulate further engagement with his work.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This Themed Section aims to increase understanding of how the idea of climate change, and the policies and actions that spring from it, travel beyond their origins in natural sciences to meet different political arenas in the developing world. It takes a discursive approach whereby climate change is not just a set of physical processes but also a series of messages, narratives and policy prescriptions. The articles are mostly case study-based and focus on sub-Saharan Africa and Small Island Developing States (SIDS). They are organised around three interlinked themes. The first theme concerns the processes of rapid technicalisation and professionalisation of the climate change ‘industry’, which have sustantially narrowed the boundaries of what can be viewed as a legitimate social response to the problem of global warming. The second theme deals with the ideological effects of the climate change industry, which is ‘depoliticisation’, in this case the deflection of attention away from underlying political conditions of vulnerability and exploitation towards the nature of the physical hazard itself. The third theme concerns the institutional effects of an insufficiently socialised idea of climate change, which is the maintenance of existing relations of power or their reconfiguration in favour of the already powerful. Overall, the articles suggest that greater scrutiny of the discursive and political dimensions of mitigation and adaptation activities is required. In particular, greater attention should be directed towards the policy consequences that governments and donors construct as a result of their framing and rendition of climate change issues.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper explores the spaces and power relations of ethical foodscapes. Ethics can offer a commodity a valuable unique selling point in a competitive marketplace but managing the changeable and multiple motivations for stakeholder participation throughout the commodity chain in order to utilise this opportunity is a complex negotiation. Through exploring the spaces and relations within three South African– UK ethical wine networks, the discursive tactics used to sustain these are uncovered. The discourses of Fairtrade, Black Economic Empowerment and organics are highly adaptive, interacting with each other in such a way as to always be contextually appealing. This ‘tactical mutability’ is combined with ‘scales of knowing’, which, this paper argues, are essential for network durability. ‘Scales of knowing’ refers to the recognition by stakeholders of the potential for different articulations of a discourse within the network, which combines with ‘tactical mutability’ to allow for a scalar, contextual and ’knowing’ (im)mutability to ensure the discourse’s continued appeal. However, even when one discourse is the ‘lead’ it always folds within it linkages to other ethical discourses at work, suggesting that ethical practice is mutually supportive discursively. This means that at the producer end ethical interactions may offer more capacity to enact genuine transformation than the solo operations of a discourse.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Black carbon aerosol plays a unique and important role in Earth’s climate system. Black carbon is a type of carbonaceous material with a unique combination of physical properties. This assessment provides an evaluation of black-carbon climate forcing that is comprehensive in its inclusion of all known and relevant processes and that is quantitative in providing best estimates and uncertainties of the main forcing terms: direct solar absorption; influence on liquid, mixed phase, and ice clouds; and deposition on snow and ice. These effects are calculated with climate models, but when possible, they are evaluated with both microphysical measurements and field observations. Predominant sources are combustion related, namely, fossil fuels for transportation, solid fuels for industrial and residential uses, and open burning of biomass. Total global emissions of black carbon using bottom-up inventory methods are 7500 Gg yr�-1 in the year 2000 with an uncertainty range of 2000 to 29000. However, global atmospheric absorption attributable to black carbon is too low in many models and should be increased by a factor of almost 3. After this scaling, the best estimate for the industrial-era (1750 to 2005) direct radiative forcing of atmospheric black carbon is +0.71 W m�-2 with 90% uncertainty bounds of (+0.08, +1.27)Wm�-2. Total direct forcing by all black carbon sources, without subtracting the preindustrial background, is estimated as +0.88 (+0.17, +1.48) W m�-2. Direct radiative forcing alone does not capture important rapid adjustment mechanisms. A framework is described and used for quantifying climate forcings, including rapid adjustments. The best estimate of industrial-era climate forcing of black carbon through all forcing mechanisms, including clouds and cryosphere forcing, is +1.1 W m�-2 with 90% uncertainty bounds of +0.17 to +2.1 W m�-2. Thus, there is a very high probability that black carbon emissions, independent of co-emitted species, have a positive forcing and warm the climate. We estimate that black carbon, with a total climate forcing of +1.1 W m�-2, is the second most important human emission in terms of its climate forcing in the present-day atmosphere; only carbon dioxide is estimated to have a greater forcing. Sources that emit black carbon also emit other short-lived species that may either cool or warm climate. Climate forcings from co-emitted species are estimated and used in the framework described herein. When the principal effects of short-lived co-emissions, including cooling agents such as sulfur dioxide, are included in net forcing, energy-related sources (fossil fuel and biofuel) have an industrial-era climate forcing of +0.22 (�-0.50 to +1.08) W m-�2 during the first year after emission. For a few of these sources, such as diesel engines and possibly residential biofuels, warming is strong enough that eliminating all short-lived emissions from these sources would reduce net climate forcing (i.e., produce cooling). When open burning emissions, which emit high levels of organic matter, are included in the total, the best estimate of net industrial-era climate forcing by all short-lived species from black-carbon-rich sources becomes slightly negative (�-0.06 W m�-2 with 90% uncertainty bounds of �-1.45 to +1.29 W m�-2). The uncertainties in net climate forcing from black-carbon-rich sources are substantial, largely due to lack of knowledge about cloud interactions with both black carbon and co-emitted organic carbon. In prioritizing potential black-carbon mitigation actions, non-science factors, such as technical feasibility, costs, policy design, and implementation feasibility play important roles. The major sources of black carbon are presently in different stages with regard to the feasibility for near-term mitigation. This assessment, by evaluating the large number and complexity of the associated physical and radiative processes in black-carbon climate forcing, sets a baseline from which to improve future climate forcing estimates.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

As the Enlightenment drew to a close, translation had gradually acquired an increasingly important role in the international circulation and transmission of scientific knowledge. Yet comparatively little attention has been paid to the translators responsible for making such accounts accessible in other languages, some of whom were women. In this article I explore how European women cast themselves as intellectually enquiring, knowledgeable and authoritative figures in their translations. Focusing specifically on the genre of scientific travel writing, I investigate the narrative strategies deployed by women translators to mark their involvement in the process of scientific knowledge-making. These strategies ranged from rhetorical near-invisibility, driven by women's modest marginalization of their own public engagement in science, to the active advertisement of themselves as intellectually curious consumers of scientific knowledge. A detailed study of Elizabeth Helme's translation of the French ornithologist Françoise le Vaillant's Voyage dans l'intérieur de l'Afrique [Voyage into the Interior of Africa] (1790) allows me to explore how her reworking of the original text for an Anglophone reading public enabled her to engage cautiously – or sometimes more openly – with questions regarding how scientific knowledge was constructed, for whom and with which aims in mind.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The purpose of this study was to develop an understanding of the current state of scientific data sharing that stakeholders could use to develop and implement effective data sharing strategies and policies. The study developed a conceptual model to describe the process of data sharing, and the drivers, barriers, and enablers that determine stakeholder engagement. The conceptual model was used as a framework to structure discussions and interviews with key members of all stakeholder groups. Analysis of data obtained from interviewees identified a number of themes that highlight key requirements for the development of a mature data sharing culture.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The typographical naivety of much scientific legibility research has caused designers to question the value of the research and the results. Examining the reasons underlying this questioning, the paper discusses the importance of designers being more accepting of scientific findings, and why legibility investigations have value. To demonstrate how typographic knowledge can be incorporated into the design of studies to increase their validity, the paper reports on a new investigation into the role of serifs when viewed at a distance. The experiment looks into the identification of the lowercase letters ‘j’, ‘i’, ‘l’, ‘b’, ‘h’, ‘n’, ‘u’, and ‘a’ in isolation. All of the letters originate in the same typeface and are presented in one version with serifs and one version without serifs. Although the experiment found no overall legibility difference between the sans serif and the serif versions, the study showed that letters with serifs placed on the vertical extremes were more legible at a distance than the same letters in a sans serif. These findings can therefore provide specific guidance on the design of individual letters and demonstrate the product of collaboration between designer and scientist on the planning, implementation, and analysis of the study.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The late eighties and early nineties in Germany were not only marked by the fall of the Wall and German unification, but also by the dramatization of the political issue of asylum, resulting in outbreaks of xenophobic violence. In the context of the asylum debate of the early nineties, a number of punk bands produced songs between 1991 and 1994 which criticise the xenophobic climate created by the asylum debate and undermine an exculpatory official discourse about the violent attacks. The lyrics of these songs will be analysed as instances of counter-discourse emerging from a subcultural sphere that nurtures a critical distance towards hegemonic public and political discourse, arguing that Critical Discourse Analysis should pay more attention to defiance of hegemonic discourse.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The automatic transformation of sequential programs for efficient execution on parallel computers involves a number of analyses and restructurings of the input. Some of these analyses are based on computing array sections, a compact description of a range of array elements. Array sections describe the set of array elements that are either read or written by program statements. These sections can be compactly represented using shape descriptors such as regular sections, simple sections, or generalized convex regions. However, binary operations such as Union performed on these representations do not satisfy a straightforward closure property, e.g., if the operands to Union are convex, the result may be nonconvex. Approximations are resorted to in order to satisfy this closure property. These approximations introduce imprecision in the analyses and, furthermore, the imprecisions resulting from successive operations have a cumulative effect. Delayed merging is a technique suggested and used in some of the existing analyses to minimize the effects of approximation. However, this technique does not guarantee an exact solution in a general setting. This article presents a generalized technique to precisely compute Union which can overcome these imprecisions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

An expert panel was convened in October 2013 by the International Scientific Association for Probiotics and Prebiotics (ISAPP) to discuss the field of probiotics. It is now 13 years since the definition of probiotics and 12 years after guidelines were published for regulators, scientists and industry by the Food and Agriculture Organization of the United Nations and the WHO (FAO/WHO). The FAO/WHO definition of a probiotic—“live microorganisms which when administered in adequate amounts confer a health benefit on the host”—was reinforced as relevant and sufficiently accommodating for current and anticipated applications. However, inconsistencies between the FAO/WHO Expert Consultation Report and the FAO/WHO Guidelines were clarified to take into account advances in science and applications. A more precise use of the term 'probiotic' will be useful to guide clinicians and consumers in differentiating the diverse products on the market. This document represents the conclusions of the ISAPP consensus meeting on the appropriate use and scope of the term probiotic.