4,762 research outputs found
Nanoscavenger based dispersion preconcentration: sub-micron particulate extractants for analyte collection and enrichment
No full textA new approach has been developed for the preconcentration of analytes from solution using nanoscavengers; monodisperse functionalised particles of sub-micron dimensions, that can be suspended as a quasi-stable sol in an aqueous solution, and quantitatively recovered with the analyte by conventional filtration. No external agitation of the sample is required as the particles move naturally through the sample by Brownian motion, convection and sedimentation. By careful choice and control of their particle size and surface chemistries, nanoscavengers can be designed to suit a number of different analytical problems. Surface modification of these nanometre-sized particles, through the grafting of complexing or partitioning functional groups, can produce nanoscavengers having affinities for specific analytes and operating through a wide range of mechanisms from covalent bonding to hydrophobic interaction. The approach is illustrated by the development of an extraction-based preconcentration of metals from solution that employs sub-micron Stober-type silica spheres, the surfaces of which have been modified using chelating diamine and dithiocarbamate groups. The concept has potentially widespread applicability as it is neither limited to metal extractions, nor to the use of silica-based nanoscavengers. Minimal involvement of organic solvents make nanoscavengers a potentially environmentally benign ("green") alternative to many conventional solvent extraction techniques
G Protein Regulation of Ion Channels and Abscisic Acid Signaling in Arabidopsis Guard Cells
No full textThe phytohormone abscisic acid (ABA) promotes plant water conservation by decreasing the apertures of stomatal pores in the epidermis through which water loss occurs. We found that Arabidopsis thaliana plants harboring transferred DNA insertional mutations in the sole prototypical heterotrimeric GTP-binding (G) protein alpha subunit gene, GPA1, lack both ABA inhibition of guard cell inward K(+) channels and pH-independent ABA activation of anion channels. Stomatal opening in gpa1 plants is insensitive to inhibition by ABA, and the rate of water loss from gpa1 mutants is greater than that from wild-type plants. Manipulation of G protein status in guard cells may provide a mechanism for controlling plant water balance
Role of a heterotrimeric G protein in regulation of Arabidopsis seed germination
No full textSeed germination is regulated by many signals. We investigated the possible involvement of a heterotrimeric G protein complex in this signal regulation. Seeds that carry a protein null mutation in the gene encoding the alpha subunit of the G protein in Arabidopsis (GPA1) are 100-fold less responsive to gibberellic acid (GA), have increased sensitivity to high levels of Glc, and have a near-wild-type germination response to abscisic acid and ethylene, indicating that GPA1 does not directly couple these signals in germination control. Seeds ectopically expressing GPA1 are at least a million-fold more responsive to GA, yet still require GA for germination. We conclude that the GPA1 indirectly operates on the GA pathway to control germination by potentiation. We propose that this potentiation is directly mediated by brassinosteroids (BR) because the BR response and synthesis mutants, bri1-5 and det2-1, respectively, share the same GA sensitivity as gpa1 seeds. Furthermore, gpa1 seeds are completely insensitive to brassinolide rescue of germination when the level of GA in seeds is reduced. A lack of BR responsiveness is also apparent in gpa1 roots and hypocotyls suggesting that BR signal transduction is likely coupled by a heterotrimeric G protein at various points in plant development
Alan Moore Comics as Performance, Fiction as Scalpel
No full textEclectic British author Alan Moore (b. 1953) is one of the most acclaimed and controversial comics writers to emerge since the late 1970s. He has produced a large number of well-regarded comic books and graphic novels while also making occasional forays into music, poetry, performance, and prose. In Alan Moore: Comics as Performance, Fiction as Scalpel , Annalisa Di Liddo argues that Moore employs the comics form to dissect the literary canon, the tradition of comics, contemporary society, and our understanding of history. The book considers Moore's narrative strategies and pinpoints the main thematic threads in his works: the subversion of genre and pulp fiction, the interrogation of superhero tropes, the manipulation of space and time, the uses of magic and mythology, the instability of gender and ethnic identity, and the accumulation of imagery to create satire that comments on politics and art history. Examining Moore's use of comics to scrutinize contemporary culture, Di Liddo analyzes his best-known works-- Swamp Thing, V for Vendetta, Watchmen, From Hell, Promethea , and Lost Girls . The study also highlights Moore?s lesser-known output, such as Halo Jones, Skizz , and Big Numbers , and his prose novel Voice of the Fire. Alan Moore: Comics as Performance, Fiction as Scalpel reveals Moore to be one of the most significant and distinctly postmodern comics creators of the last quarter-century.Intro -- Contents -- Preface and Acknowledgments -- Introduction -- CHAPTER 1. Formal Considerations on Alan Moore's Writing -- CHAPTER 2. Chronotopes: Outer Space, the Cityscape, and the Space of Comics -- CHAPTER 3. Moore and the Crisis of English Identity -- CHAPTER 4. Finding a Way into Lost Girls -- Conclusion -- Notes -- Bibliography -- Index -- A -- B -- C -- D -- E -- F -- G -- H -- I -- J -- K -- L -- M -- N -- O -- P -- Q -- R -- S -- T -- U -- V -- W -- Y -- ZEclectic British author Alan Moore (b. 1953) is one of the most acclaimed and controversial comics writers to emerge since the late 1970s. He has produced a large number of well-regarded comic books and graphic novels while also making occasional forays into music, poetry, performance, and prose. In Alan Moore: Comics as Performance, Fiction as Scalpel , Annalisa Di Liddo argues that Moore employs the comics form to dissect the literary canon, the tradition of comics, contemporary society, and our understanding of history. The book considers Moore's narrative strategies and pinpoints the main thematic threads in his works: the subversion of genre and pulp fiction, the interrogation of superhero tropes, the manipulation of space and time, the uses of magic and mythology, the instability of gender and ethnic identity, and the accumulation of imagery to create satire that comments on politics and art history. Examining Moore's use of comics to scrutinize contemporary culture, Di Liddo analyzes his best-known works-- Swamp Thing, V for Vendetta, Watchmen, From Hell, Promethea , and Lost Girls . The study also highlights Moore?s lesser-known output, such as Halo Jones, Skizz , and Big Numbers , and his prose novel Voice of the Fire. Alan Moore: Comics as Performance, Fiction as Scalpel reveals Moore to be one of the most significant and distinctly postmodern comics creators of the last quarter-century.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
Politics of state constitutional reform
No full textIncludes bibliographical references and index.edited by G. Alan Tarr and Robert F. Williams.Constitutional revision in Florida : planning, politics, policy, and publicity / Rebecca Mae Salokar -- Constitutional revision in California : the triumph of amendment over revision / Bruce E. Cain -- Adopting a new constitution : lessons from Virginia / A. E. Dick Howard -- Constitutional reform in Alabama : long time in coming / H. Bailey Thomson -- The mandatory constitutional convention question referendum : the New York experience in national context / Gerald Benjamin -- Direct democracy and constitutional reform : campaign finance initiatives in Colorado / Anne G. Campbell
Post-war British working-class fiction with special reference to the novels of John Braine, Alan Sillitoe, Stan Barstow, David Storey and Barry Hines
No full textThis study is about British working-class fiction in the post-war period.
It covers various authors such as Robert Tressell, George Orwell, Walter Greenwood, Lewis Grassic Gibbon and DH Lawrence from the early twentieth century; writers traditionally classified as 'Angry Young Men' like John Osborne, Arnold Wesker, Shelagh Delaney, John Wain and
Kingsley Amis; and working-class novelists like John Braine, Stan Barstow, David Storey, Alan Sillitoe and Barry Hines from the 1950s and 1960s.
Some of the main issues dealt with in the course of this study are language, form, community, self/identity/autobiography, sexuality and relationship with bourgeois art. The major argument centres on two questions: representation of working-class life, and the
relationship between working-class literary tradition and dominant ideologies.
We will be arguing that while working-class fiction succeeded in challenging and rupturing bourgeois literary tradition, on the level of language and linguistic medium of expression for example, it utterly failed to break away from dominant, bourgeois modes of literary production in relation to form, for instance.
Our argument is situated within Marxist approaches to literature, a political and aesthetic position from which we attempt an analysis and an evaluation of this working-class literary tradition. These critical approaches provide us also with the theoretical tool to define the political perspective of this tradition, and to judge whether it was confined to a descriptive mode of representation or
located in a radical, political outlook
Synthesis and modification of mercapto-submicron scavenger for real-time extraction and preconcentration of As(III)
No full textThe gradual increase of arsenic in aquatic layers over the last decades has necessitated the early detection of low levels of arsenic on real time due to its hazardous impact on health. Here, the mercapto-submicron scavenger was synthesized and utilized for solid-phase dispersion extraction technique for real-time extraction and preconcentration of arsenite As(iii). Because of particle size, they naturally dispersed without the need for any additional power. The formation of particles and the achievement of the modification of the particles were confirmed by SEM, TEM, size distributions, CHN analysis, FT-IR spectroscopy, micro-Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), zeta potential, energy dispersive X-ray analysis and (EDX) and thermogravimetric analysis (TGA), which confirmed the formation of particles in the size of 253 ± 34 nm, the chemical implantation of the mercapto groups on the surface was successfully accomplished with a loading of 0.281 mmol g-1. The particles showed proper dispersion and stability in the aqueous phase before and after being associated with As(iii). The chelating process between As(iii) and mercapto groups was assessed by XPS which confirmed that the mercapto-submicron scavenger can sequestrate As(iii) from water with maximum efficiency. Several factors that could optimize the process were assessed such as the effect of sorbent dose, pH, contact time, sample volumes, eluents, and matrix interference. The As(iii) calibration curve showed a positive linear correlation in the range of 0-100 μg L-1 and coefficient of determination (r2 = 0.9981). Optimum recovery was obtained with an equilibrium time of 30 min at pH = 8.5. It was found that the release of As(iii) from the mercapto-submicron scavenger was eluent dependent and the maximum recovery at the optimum conditions was 98 ± 3%. The average recovery of As(iii) from three different ground water locations was 97.15%.</p
Selective pre-concentration of selenite from aqueous samples using mercapto-silica
No full textSilica gel modified with 3-mereaptopropyl-trimethoxysilane was used for the selective separation and pre-concentration of selenite (Se(IV)) from aqueous solutions containing Se(IV) and selenate (Se(VI)). Over a wide range of acidity, from 2 mol 1(-1) HCl to pH 9.00, Se(IV) was taken up by the mercaptopropyl-silica with nearly 100% efficiency; Se(VI) however was unretained. Se(IV) content was determined by hydride generation atomic absorption spectrometry (HGAAS), following batch release of the selenium from the pre-concentration medium by acidic periodate. The overall pre-concentration efficiency, including both take-up and elution, in the range of 89-106%. The method was applied to spiked seawater samples containing as low as 800 ng 1(-1) Se in selenite form. This solid-phase extraction system offers several major advantages over conventional solvent extraction procedures. It firstly exhibits high selectivity for Se(IV) over Se(VI). Using the solid-phase media, pre-concentration of Se(IV) in dilute water samples can be carried out in the field, stabilizing the selenite-selenium in a convenient form for transport and storage. In addition, selenium stored on silica is derived solely from Se(IV) overcoming problems of selenium redox speciation changes and loss during storage
The construction of Karen Karnak: The multi-author-function
No full textThis thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author
Is There an Impact of Household Computer Ownership on Childrens Educational Attainment in Britain?
No full textIf personal computers (PCs) are used to enhance learning and information gathering across avariety of subjects, then a home computer might reasonably be considered an input in aneducational production function. Using data on British youths from the British HouseholdPanel Survey between 1991 and 2001, this paper attempts to explore the link betweenownership of a home computer at ages 15 and 17 and subsequent educational attainment inthe principal British school examinations taken at ages 16 (GCSEs) and 18 (A levels). Thedata show a significant positive associatio n between PC ownership and both the number ofGCSEs obtained and the probability of passing five or more GCSEs. These results survive aset of individual, household, and area controls, including using other household durables and\"future\" PC ownership as proxies for household wealth and other unobservable householdlevel effects. Home computer ownership is also associated with a significant increase in theprobability of passing at least one A level conditional on having passed five and increase inthe probability of successfully completing three or more A levels, conditional on havingpassed at least one A level.Human capital, Economic Impact, Personal Computers
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