53 resultados para controversy
Resumo:
Effective collision strengths for forbidden transitions among the five energetically lowest fine-structure levels of O ii are calculated in the Breit-Pauli approximation using the R-matrix method. Results are presented for the electron temperature range 100-100 000 K. The accuracy of the calculations is evaluated via the use of different types of radial orbital sets and a different configuration expansion basis for the target wavefunctions. A detailed assessment of previous available data is given, and erroneous results are highlighted. Our results reconfirm the validity of the original Seaton and Osterbrock scaling for the optical O ii ratio, a matter of some recent controversy. Finally, we present plasma diagnostic diagrams using the best collision strengths and transition probabilities.
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Aside from the more mundane purpose of telling us where to eat, sleep and sightsee in foreign lands, guidebooks communicate an ethical vision that sees travel as the key to reducing cultural differences and inequalities. This article argues that Lonely Planet guidebooks in particular encourage a form of ‘responsible independent travel’ that both reflects and produces a powerful discourse of humanitarianism. By examining the controversy over Lonely Planet’s publication of guidebooks to Burma, this article uncovers the problematic colonial logic embedded in that ethical vision.
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The mechanism of energy converting NADH:ubiquinone oxidoreductase (complex 1) is Still unknown. A current controversy centers around the question whether electron transport of complex I is always linked to vectorial proton translocation or whether in some organisms the enzyme pumps sodium ions instead. To develop better experimental tools to elucidate its mechanism, we have reconstituted the affinity purified enzyme into proteoliposomes and monitored the generation of Delta pH and Delta psi. We tested several detergents to solubilize the asolectin used for liposome formation. Tightly coupled proteoliposomes containing highly active complex I were obtained by detergent removal with BioBeads after total solubilization or the phospholipids with n-octyl-beta-D-glucopyranoside. We have used dyes to monitor the formation of the two components of the proton motive force, Delta pH and Delta psi, across the liposomal membrane, and analyzed the effects of inhibitors, uncouplers and ionophores on this process. We show that electron transfer of complex I of the lower eukaryote Y. lipolytica is clearly linked to proton translocation. While this study was not specifically designed to demonstrate possible additional sodium translocating properties of complex 1, we did not find indications for primary or secondary Na+ translocation by Y lipolytica complex I. (c) 2005 Elsevier B.V. All rights reserved.
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The growing visibility of various forms of creationism in Northern Ireland raises issues for science education. Attempts have been made at political levels to have such “alternatives” to evolution taught in the science classroom, and the issue has received coverage in local press and media. A sample of 112 pre-service science teachers answered a survey on attitudes toward evolution. Preliminary analysis revealed many of these new teachers held views contrary to scientific consensus—over one fifth doubt the evidence for human evolution, and over one quarter dispute the common ancestry of life. Over two thirds indicated a preference for teaching a “range of theories” regarding these issues in science. In addition, 49 pre-service biology teachers viewed a DVD resource promoting “intelligent design” and completed an evaluation of it. The biology teachers also took part in either focus groups or additional questionnaires. A majority took the resource at face value and made positive comments regarding its utility. Many articulated views contrary to the stated positions of science academies, professional associations, and the UK government teaching directives regarding creationism. Most indicated a perception that intelligent design is legitimate science and that there is a scientific “controversy” regarding the legitimacy of evolution. Concern is raised over the ability of these new teachers to distinguish between scientific and non-scientific theories. The suggestion is made that the issue should be addressed directly with pre-service science teachers to make clear the status of such “alternatives.” The paper raises implications for science education and questions for further research.
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The right to self-defence has lately been subjected to intense academic controversy, both at the domestic and international level. The debate is focused on the question of whether or not the requirement of imminence is merely a translator for the notion of necessity. At the domestic level, the debate has mainly been kindled by feminist scholars, who, in the context of the 'battered woman', argue that the requirement of imminence should be discarded from the contours of the self-defence doctrine. The purpose of this article is to prove the necessity of the imminence requirement as a litmus test to detect possible abuses of the self-defence doctrine.
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Historians of Ireland have devoted considerable attention to the Presbyterian origins of modern Irish republicanism in the 1790s and their overwhelming support for the Union with Great Britain in the 1880s. On the one hand, it has been argued that conservative politics came to dominate nineteenth-century Presbyterianism in the form of Henry Cooke who combined conservative evangelical religion with support for the established order. On the other hand, historians have long acknowledged the continued importance of liberal and radical impulses amongst Presbyterians. Few historians of the nineteenth century have attempted to bring these two stories together and to describe the relationship between the religion and politics of Presbyterians along the lines suggested by scholars of Presbyterian radicalism in the last quarter of the eighteenth century. This article argues that a distinctive form of Presbyterian evangelicalism developed in the nineteenth century that sought to bring the denomination back to the theological and spiritual priorities of seventeenth-century Scottish and Irish Presbyterianism. By doing so, it encouraged many Presbyterians to get involved in movements for reform and liberal politics. Supporters of ‘Covenanter Politics’ utilised their denominational principles and traditions as the basis for political involvement and as a rhetoric of opposition to Anglican privilege and Catholic tyranny. These could be the prime cause of Presbyterian opposition to the infringement of their rights, such as the marriage controversy and the Disruption of the Church of Scotland in the early 1840s, and they could also be employed as a language of opposition in response to broader social and political developments, such as the demands for land reform stimulated by the agricultural depression that accompanied the Famine. Despite their opposition to ascendancy, however, the Covenanter Politics of Presbyterian Liberals predisposed them towards pan-protestant unionism against the threat of ‘Rome Rule’.
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An optimal search theory, the so-called Levy-flight foraging hypothesis(1), predicts that predators should adopt search strategies known as Levy flights where prey is sparse and distributed unpredictably, but that Brownian movement is sufficiently efficient for locating abundant prey(2-4). Empirical studies have generated controversy because the accuracy of statistical methods that have been used to identify Levy behaviour has recently been questioned(5,6). Consequently, whether foragers exhibit Levy flights in the wild remains unclear. Crucially, moreover, it has not been tested whether observed movement patterns across natural landscapes having different expected resource distributions conform to the theory's central predictions. Here we use maximum-likelihood methods to test for Levy patterns in relation to environmental gradients in the largest animal movement data set assembled for this purpose. Strong support was found for Levy search patterns across 14 species of open-ocean predatory fish (sharks, tuna, billfish and ocean sunfish), with some individuals switching between Levy and Brownian movement as they traversed different habitat types. We tested the spatial occurrence of these two principal patterns and found Levy behaviour to be associated with less productive waters (sparser prey) and Brownian movements to be associated with productive shelf or convergence-front habitats (abundant prey). These results are consistent with the Levy-flight foraging hypothesis(1,7), supporting the contention(8,9) that organism search strategies naturally evolved in such a way that they exploit optimal Levy patterns.
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An investigation of the long controversy around the definition of an Italian New Wave cinema of the 1960s, this essay engages (and takes issue) with the reasons behind the critics’ reluctance to recognise its existence. After establishing a theoretical and historical framework for a transnational under- standing of the phenomenon of the European and World New Waves, it offers a reasoned analysis of the multiple industrial and artistic attempts at a generational renewal of Italian cinema that were made in Italy during the 1960s. Ultimately, the essay suggests that it would not only be appropriate, but also highly productive to reconsider the vibrant and heterogeneous young Italian cinema of the 1960s under the generational and transnational New Wave label, instead of continuing to approach the decade exclusively in the light of Neorealism.
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The right to be presumed innocent until proven guilty has been described as the 'golden thread' running through the web of the English criminal law and a 'fundamental postulate' of Irish criminal law which enjoys constitutional protection. The purpose of this book is to consider whether the reality matches the rhetoris surrounding this central precept of our criminal law and to consider its efficacy in light of recent legislative innovations.
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Administration of Na(+)/H(+) exchange isoform-1 (NHE-1) inhibitors before ischemia has been shown to attenuate myocardial infarction in several animal models of ischemia-reperfusion injury. However, controversy still exists as to the efficacy of NHE-1 inhibitors in protection of myocardial infarction when administered at the onset of reperfusion. Furthermore, the efficacy of NHE-1 inhibition in protection of skeletal muscle from infarction (necrosis) has not been studied. This information has potential clinical applications in prevention or salvage of skeletal muscle from ischemia-reperfusion injury in elective and trauma reconstructive surgery. The objective of this research project is to test our hypothesis that the NHE-1 inhibitor cariporide is effective in protection of skeletal muscle from infarction when administered at the onset of sustained ischemia or reperfusion and to study the mechanism of action of cariporide. In our studies, we observed that intravenous administration of cariporide 10 min before ischemia (1 or 3 mg/kg) or reperfusion (3 mg/kg) significantly reduced infarction in pig latissimus dorsi muscle flaps compared with the control, when these muscle flaps were subjected to 4 h of ischemia and 48 h of reperfusion (P <0.05; n = 5 pigs/group). Both preischemic and postischemic cariporide treatment (3 mg/kg) induced a significant decrease in muscle myeloperoxidase activity and mitochondrial-free Ca(2+) content and a significant increase in muscle ATP content within 2 h of reperfusion (P <0.05; n = 4 pigs/group). Preischemic and postischemic cariporide treatment (3 mg/kg) also significantly inhibited muscle NHE-1 protein expression within 2 h of reperfusion after 4 h of ischemia, compared with the control (P <0.05; n = 3 pigs/group). These observations support our hypothesis that cariporide attenuates skeletal muscle infarction when administered at the onset of ischemia or reperfusion, and the mechanism involves attenuation of neutrophil accumulation and mitochondrial-free Ca(2+) overload and preservation of ATP synthesis in the early stage of reperfusion.
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This book is a study of the British Board of Film Censors in the 1970s. In permitting and refusing specific material to be shown on cinema screens the BBFC were dictating patterns of taste and helping shape and determine notions of acceptability. Contentious and controversial texts like A Clockwork Orange (1971), Straw Dogs (1971) The Devils (1971) and Life of Brian (1979) have been used to draw attention to the way in which the BBFC operated in the 1970s. While it is true to say that these films encountered major censorship problems, what of the hundreds of other films which were being classified at the same time? Did all films struggle with the British censors in this period, and can these famous examples be fitted into broader patterns of censorship policy and practice?
In studying over 250 film files from the BBFC archive, this work reveals how 1970s films such as Vampire Circus (1971), Confessions of a Window Cleaner (1974) and Carry on Emmannuelle (1978) also ran in to trouble with the film censor. This work explores the complex process of negotiation and compromise which affected all film submissions in the 1970s and the way in which the BBFC actively, and often sympathetically, negotiated with film directors, producers and distributors to assign the correct category to each film. The lack of any defined formal censorship policy in this period allowed the BBFC to work alongside the film industry and push cultural, social and artistic boundaries; however it also left the Board open to accusations of favouritism, subjectivity and personal bias.
This work is not simply a study of controversial films and contentious issues, but rather engages with wider issues of changing permission, legal struggles, the influence of the media and the legislative and governmental controls which both helped and hindered the BBFC in this important post-war decade. The approach used within this work focuses on historical and archival research, making it importantly inter-textual and offering a great deal to scholars from a number of associated disciplines, including history, social policy, media and communications and politics.
Resumo:
This chapter is an exploration of film censorship in the 1970s and the role of the British Board of Film Censors. It draws on material from the BBFC archive files and addresses issues of popular taste, taboo and changing standards of permission.
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The Mollusca is one of the most diverse, important and well-studied invertebrate phyla; however, relationships among major molluscan taxa have long been a subject of controversy(1-9). In particular, the position of the shell-less vermiform Aplacophora and its relationship to the better-known Polyplacophora (chitons) have been problematic: Aplacophora has been treated as a paraphyletic or monophyletic group at the base of the Mollusca(3,6,8), proximate to other derived clades such as Cephalopoda(2,3,10), or as sister group to the Polyplacophora, forming the clade Aculifera(1,5,7,11,12). Resolution of this debate is required to allow the evolutionary origins of Mollusca to be reconstructed with confidence. Recent fossil finds(13-16) support the Aculifera hypothesis, demonstrating that the Palaeozoic-era palaeoloricate 'chitons' included taxa combining certain polyplacophoran and aplacophoran characteristics(5). However, fossils combining an unambiguously aplacophoran-like body with chiton-like valves have remained elusive. Here we describe such a fossil, Kulindroplax perissokomos gen. et sp. nov., from the Herefordshire Lagerstatte(17,18) (about 425 million years BP), a Silurian deposit preserving a marine biota(18) in unusual three-dimensional detail. The specimen is reconstructed three-dimensionally through physical-optical tomography(19). Phylogenetic analysis indicates that this and many other palaeoloricate chitons are crown-group aplacophorans.
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GHMP kinases are a group of structurally-related small molecule kinases. They have been found in all kingdoms of life and are mostly responsible for catalysing the ATP-dependent phosphorylation of intermediary metabolites. Although the GHMP kinases are of clinical, pharmaceutical and biotechnological importance, the mechanism of GHMP-kinases is controversial. A catalytic base mechanism was suggested for mevalonate kinase that has a structural feature of the ?-phosphate of ATP close to an aspartate residue; however, for one GHMP member, homoserine kinase, where the residue acting as general base is absent, a direct phosphorylation mechanism was suggested. Furthermore, it has been proposed by some authors that all the GHMP kinases function via the direct phosphorylation mechanism. This controversy in mechanism has limited our ability to exploit these enzymes as drug targets and in biotechnology. Here the phosphorylation reaction mechanism of the human galactokinase, a member of GHMP kinase was investigated using molecular dynamics simulations and density functional theory-based QM/MM calculations (B3LYP-D/AMBER99). The reaction coordinates were localized by potential energy scan using adiabatic mapping method. Our results indicate that a highly conserved Glu174 captures Arg105 to the proximity of the a-phosphate of ATP forming a H-bond network, therefore the mobility of ATP in the large oxyanion hole is restricted. Arg228 functions to stabilize the negative charge developed at the ß,?-bridging oxygen of the ATP during bond cleavage. The reaction occurs via direct phosphorylation mechanism and the Asp186 in proximity of ATP does not directly participate in the reaction pathway. Since Arg228 is not conserved among GHMP kinases, reagents which form interactions with Arg228, and therefore can interrupt its function in phosphorylation may be developed into potential selective inhibitors for galactokinase.
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In spite of the controversy that they have generated, neutral models provide ecologists with powerful tools for creating dynamic predictions about beta-diversity in ecological communities. Ecologists can achieve an understanding of the assembly rules operating in nature by noting when and how these predictions are met or not met. This is particularly valuable for those groups of organisms that are challenging to study under natural conditions (e.g., bacteria and fungi). Here, we focused on arbuscular mycorrhizal fungal (AMF) communities and performed an extensive literature search that allowed us to synthesize the information in 19 data sets with the minimal requisites for creating a null hypothesis in terms of community dissimilarity expected under neutral dynamics. In order to achieve this task, we calculated the first estimates of neutral parameters for several AMF communities from different ecosystems. Communities were shown either to be consistent with neutrality or to diverge or converge with respect to the levels of compositional dissimilarity expected under neutrality. These data support the hypothesis that divergence occurs in systems where the effect of limited dispersal is overwhelmed by anthropogenic disturbance or extreme biological and environmental heterogeneity, whereas communities converge when systems have the potential for niche divergence within a relatively homogeneous set of environmental conditions. Regarding the study cases that were consistent with neutrality, the sampling designs employed may have covered relatively homogeneous environments in which the effects of dispersal limitation overwhelmed minor differences among AMF taxa that would lead to environmental filtering. Using neutral models we showed for the first time for a soil microbial group the conditions under which different assembly processes may determine different patterns of beta-diversity. Our synthesis is an important step showing how the application of general ecological theories to a model microbial taxon has the potential to shed light on the assembly and ecological dynamics of communities.