163,372 research outputs found
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A new look at the pathogenesis of asthma
No full textAsthma is an inflammatory disorder of the conducting airways that has strong association with allergic sensitization. The disease is characterized by a polarized Th-2 (T-helper-2)-type T-cell response, but in general targeting this component of the disease with selective therapies has been disappointing and most therapy still relies on bronchodilators and corticosteroids rather than treating underlying disease mechanisms. With the disappointing outcomes of targeting individual Th-2 cytokines or manipulating T-cells, the time has come to re-evaluate the direction of research in this disease. A case is made that asthma has its origins in the airways themselves involving defective structural and functional behaviour of the epithelium in relation to environmental insults. Specifically, a defect in barrier function and an impaired innate immune response to viral infection may provide the substrate upon which allergic sensitization takes place. Once sensitized, the repeated allergen exposure will lead to disease persistence. These mechanisms could also be used to explain airway wall remodelling and the susceptibility of the asthmatic lung to exacerbations provoked by respiratory viruses, air pollution episodes and exposure to biologically active allergens. Variable activation of this epithelial-mesenchymal trophic unit could also lead to the emergence of different asthma phenotypes and a more targeted approach to the treatment of these. It also raises the possibility of developing treatments that increase the lung's resistance to the inhaled environment rather than concentrating all efforts on trying to suppress inflammation once it has become established.<br/
Larry O. Spencer, Conference Author Presentation
No full textGen. Larry O. Spencer, USAF (Ret.), author of Dark Horse: A Journey from the Horseshoe to the Pentago
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Subjective reaction to vertical mechanical shocks of various waveforms
No full textTwo laboratory studies have been conducted to assess the discomfort caused to seated male subjects by exposures to vertical whole-body mechanical shocks. The first experiment was designed to obtain judgements of the discomfort of single "up" or "down" damped sinusoidal impulses. Sixteen subjects used the method of magnitude estimation to indicate the discomfort produced by damped sine waves at nominal frequencies of 1, 4 and 16 Hz, with damping ratios of 0·125, 0·250 and 0·707 and vibration dose values ranging from 0·6 to 4·0 m s-1·75. Analysis was also conducted to determine whether the growth of discomfort with increasing magnitude was influenced by frequency, duration or direction of motion. The results suggested that a single frequency weighting and a single duration weighting is appropriate at all magnitudes. Analysis was also conducted to determine whether the discomfort depends on the frequency, duration and direction of shocks when they are presented at a constant vibration dose value using frequency weighting Wb. There was no difference between the discomfort caused by "up" and "down" shocks of the same vibration dose value, but the Wb frequency weighting slightly underestimated sensitivity to low-frequency shocks. The second experiment sought to compare two methods of evaluating stimuli containing between one and 16 repeated shocks. The vibration dose value [∫o T a4(t) dt] 1 4 and a measure of dose related to "energy", [∫o T a2(t) dt] 1 2, were employed to predict the reduction in shock magnitude required to counteract any increased discomfort with a greater number of shocks. Subjects employed the method of paired comparison. Judgements of the relative discomfort of the stimuli presented in pairs indicated that the vibration dose value provided the more accurate method of evaluating the discomfort of the shocks.</p
Organic synthesis in ionic liquids
No full textSolvents play an important role in organic chemistry. Most reactions must be carried out in organic solvents, thus chemists have to deal with large volumes of solvents everyday. Solvents are highly damaging chemicals for two main reasons; (a) they are used on a large scale and (b) they are volatile which makes storage and handling difficult. For environmental protection and reduction of damage to humans, clean technologies have become a major concern throughout both industry and academia. Therefore, the search for the replacement of damaging solvents has become a high priority.
Based on such an idea, reactions involving the room temperature and moisture stable 1,3- dialkylimidazolium ionic liquids, have been carried out in an effort to replace the common bench solvents. They are a new type of solvent with attractive properties allowing for their use as both solvent and catalyst in some cases.
Therefore, throughout this project the ambient temperature 1,3-dialkylimidazolium ionic liquid was employed firstly for the reduction of simple aldehydes and ketones. In the exploration of these ionic liquids as possible replacements for classical organic solvents, we discovered that the reduction of aldehydes and ketones with sodium borohydride in [bmim]PF6 can be achieved. The ionic liquid can be recycled, and in some cases the product alcohol may be distilled directly from the ionic liquid eliminating classical organic solvents entirely.
Secondly, free radical addition reactions using tributyltin hydride, a variety of alkenes and alkyl halides were carried out in the ionic liquids [bmim]BF4 and [bmim]PF6. The reactions using tributyltin hydride were carried out under a number of experimental conditions but the toxicity of the tin by-products produced was a major concern. The ionic liquid was capable of dissolving all reactants and extraction of the products was efficient but the tin by-products proved extremely difficult to remove. (Tris)trimethylsilylsilane was then used in an effort to remove the toxicity and by-product problems. The hydrosilylated product was formed but the target compound was not synthesised. The use of the ionic liquid in these radical reactions, although not a complete success, the hydrosilylated product was formed which suggests that the ionic liquid did stabilise radicals formed.
Finally, a novel type of ionic liquid was synthesised and investigated. These compounds were based on 1-vinylimidazole and the synthesis was very efficient and easily carried out. A series of 1-vinyl-3-alkyl-imidazolium bromide, tetrafluoroborate and hexafluorophosphate compounds were synthesised. It was hoped that the vinyl group of these ionic liquids could be used in a Diels-Alder synthesis using a variety of dienes
Theory and practice in critical thinking A level and the evacuation of knowledge thesis
No full textThe concept of critical thinking has been influential in curriculum policy and practice across sectors of UK education and has been identified as a key consideration in recent consultations about A level reform. The purpose of this study is to describe the meanings attributed to critical thinking in expert accounts and to compare these with policy maker and participant meanings in the context of A level Critical Thinking. A distinctive feature is the attention given to underlying epistemological and ontological assumptions of these accounts. The prevailing concept of critical thinking is of a universally applicable set of skills and dispositions for assessing reasoning and evidence, which derives from the informal logic movement and rests on a fallibilist epistemology. This contrasts with discipline specific concepts. In social realist theory critical thinking has been associated with ‘soft genericism’ and implicated in an ‘evacuation of knowledge’. A critique and extension of this theory is proposed which differentiates between multiple forms and functions of critical thinking in the curriculum. Evidence on student views was gathered in a mixed methods case study, supplemented by a teacher response activity. Students attributed high value to critical thinking and were confident in their ability to apply skills to academic and life situations; whilst they felt that these skills were not taught in other subjects. In apparent contradiction, teachers suggested correspondence between the skills expected for high performance across subjects and those in A level Critical Thinking. Additionally, they emphasized the importance of subject specific contextualising to depth of critical evaluation. It was concluded that knowledge and critical thinking are complementary rather than conflicting forces in education and that a differently conceived critical thinking based on social constructionist epistemology is compatible with and essential to the knowledge curriculum envisaged by social realists
Dietary intervention improves the survival of cultured greenlip abalone (Haliotis laevigata Donovan) at high water temperature
No full textAbstract not availableDavid A.J. Stone, Matthew S. Bansemer, Brett Lange, Elise N. Schaefer, Gordon S. Howarth, James O. Harri
A study of langmuir-blodgett films of valinomycin
No full textThe deposition and characterisation of Langmuir-Blodgett (LB) films containing the ionophore valinomycin are described. In particular, the thesis concentrates on two specific mixed LB systems incorporating the ionophore, namely, arachidic acid/valinomycin and L-a-phosphatidic acid dipalmitoyl (DPPA)/valinomycin. The extremely sensitive spectroscopic technique of attenuated total reflection (ATR) Fourier transform infrared (FTRIR) spectroscopy is used to investigate the interaction of these ultra-thin LB structures with aqueous solutions containing potassium ions. It is shown that LB layers of pure valinomycin do not complex with potassium ions and that, in order for complexation to occur, the ionophore must be mixed with a secondary component. The formation of the valinomycin-potassium (VM/K(^+)) complex in the arachidic acid/vahnomycin system is demonstrated and the effects of the mole-fraction of arachidic acid, and of the potassium ion concentration upon complexation are described. The IR studies also reveal profound structural changes in the fatty acid matrix upon complexation, and the important result that dissociation of the VM/K(^+) complex does not occur in this mixed system. However, it is shown that if the fatty acid molecule is replaced by the phosphohpid molecule, DPPA, then both formation and dissociation of the complex occur. The results, however, indicate that this system is unstable with loss of the LB film into the aqueous solution during immersion. A number of attempts to eliminate this problem are described. The fabrication and characterisation of ion-selective-field-effect transistors (IS-FETs) are also reported. One of the aims of the research is to develop a potassium- ion sensor, and with this in mind, the deposition of LB films onto the gate surface of the ISFET is demonstrated. The K(^+)-response of the LB film coated devices is described and the results interpreted in terms of the IR evidence
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