4,787 research outputs found
Interview with Ronald Sukenick, author
No full textRonald Sukenick is the author of Up, The Death of the Novel, Other Stories, and the experimental novel, Out. In this interview Sukenick discusses the development of his fiction in light of his own experiences. Interviewed by Charles Russell, research specialist for the UW-Milwaukee Center for Twentieth Century Studies.GrayscaleSoun
Electrokinetic measurements of membrane capacitance and conductance for pancreatic -cells
No full textAuthor Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of IEE for personal use, not for redistribution. The definitive version was published in IEE Proceedings - Nanobiotechnology 152 (2005): 189-193, doi:10.1049/ip-nbt:20050040.Membrane capacitance and membrane conductance values are reported for insulin secreting cells (primary β-cells and INS-1 insulinoma cells) determined using the methods of dielectrophoresis and electrorotation. The membrane capacitance value of 12.57 (± 1.46) mF/m2 obtained for β-cells, and the values 9.96 (± 1.89) mF/m2 to 10.65 (± 2.1) mF/m2 obtained for INS-1 cells, fall within the range expected for mammalian cells. The electrorotation results for the INS-1 cells lead to a value of 36 (± 22) S/m2 for the membrane conductance associated with ion channels, if values in the range 2nS to 3 nS are assumed for the membrane surface conductance. This membrane conductance value falls within the range reported for INS cells obtained using the whole-cell patch-clamp technique. However, the total ‘effective’ membrane conductance value of 601 (± 182) S/m2 obtained for the INS-1 cells by dielectrophoresis is significantly larger (by a factor of around three-fold) than the values obtained by electrorotation. This could result from an increased membrane surface conductance, or increased passive conduction of ions through membrane pores, induced by the larger electric field stresses experienced by cells in the dielectrophoresis experiments.This study was financed by a gift from the Denis Robinson Memorial Fund to RP and NIH grants NCRR RR001395 and DK06984 to PJSS
Nonlinear Production, Abatement, Pollution and Materials Balance Reconsidered
No full textIn the environmental economics literature the standard approach of modeling nonlinear production and abatement processes is to treat waste emissions "simply as another factor of production" (Cropper and Oates 1992). That approach doesn't map the materials flow involved completely and hides, moreover, the exact links between production, residuals generation and abatement. This paper shows that production functions with emissions treated as inputs can be reconstructed as a subsystem of a comprehensive production-cum-abatement technology that is in line with the materials-balance principle. In a simple economy with full regard of the materials flow it also explores the consequences for allocative efficiency and efficiency-restoring taxation of multiple and interdependent residuals generated in the transformation processes of production, abatement and consumption. Finally, the paper demonstrates that efficiency may require setting the emissions tax rate above or below conventionally defined marginal abatement cost if the residual subject to abatement is not the only residual causing pollution.residuals, abatement, pollution, materials balance
Dielectrophoretic investigations of internal cell properties
No full textDielectrophoresis (DEP) is a term which describes the motion of polarisable particles
induced by a non-uniform electric field. It has been the subject of research into a variety of
fields including nanoassembly, particle filtration and biomedicine. The application of DEP to
the latter has gained significant interest in recent years, driven by the development of
microfluidic “Lab-on-a-chip” devices designed to perform sophisticated biochemical
processes. It provides the ability to characterise and selectively manipulate cells based on
their distinct dielectric properties in a manner which is non-invasive and label free, by using
electrodes which can be readily integrated with microfluidic channels.
Under appropriate conditions a biological cell will experience a DEP force directing it either
towards or away from concentrations in the electric field. At a so-called “crossover
frequency” the cell is effectively invisible to the field resulting in no DEP force, a response
typically observed in the 1 kHz to 1 MHz range. Its value is a function of cell membrane
dielectric properties and has been the subject of research directed at devices capable of using
it to both characterise and sort cells.
The aim of this work was to investigate the behaviour of a higher frequency crossover
referred to as fxo2, predicted to occur in the 1 MHz to 1 GHz range. At these frequencies the
electric field is expected to penetrate the cell membrane and behave as a function of
intracellular dielectric properties. Standard lithography techniques have been used to
fabricate electrodes carefully designed to operate at these frequencies. The existence of fxo2
was then confirmed in murine myeloma cells, in good agreement with dielectric models
derived from impedance spectroscopy. A temperature dependent decrease in its value was
observed with respect to the time that cells were suspended in a DEP solution. This decrease
is consistent with previous studies which indicated an efflux of intracellular ions under
similar conditions.
An analytical derivation of fxo2 demonstrates its direct proportionality to intracellular
conductivity. Direct control of the crossover was achieved by using osmotic stress to dilute
the intracellular compartment and thereby alter its conductivity. By using a fluorophore
which selectively binds to potassium, a strong relationship has been demonstrated between
the value of fxo2 and the concentration of intracellular potassium. Measurements of fxo2 for an
unfed culture demonstrated a correlation with viability and subtle shifts in its distribution
were caused by the early stages of chemically induced apoptosis
A Framework for Studying Organizational Innovation in Research Libraries
No full textThe objective of this paper is two-fold: to propose a theoretical framework and model for studying organizational innovation in research libraries and to set forth propositions that can provide directions for future empirical studies of innovation in research libraries. Research libraries can be considered members of a class of organizations referred to here as institutional nonprofits. As such, these organizations inherit many of the innovative properties that are associated with the broader sector of service organizations. However, institutional nonprofits have unique characteristics that distinguish them from other service organizations such as government agencies and for-profit service firms. In this paper, institutional theory is used to explain the forces that are acting on the research library. Research from organizational learning, structural contingency theory, and typologies of service organizations are used to establish a more encompassing innovation framework. Based on the literature review, the theoretical framework, and empirical studies, this paper presents a process model and propositions that characterize how the research library might innovate. These propositions can be tested in empirical studies to develop a fuller understanding of innovation in research libraries.The published version of this article is available at: http://crl.acrl.org/content/73/6/525.full.pdf+htmlPeer reviewe
Information Retrieval in Domain Specific Databases: An Analysis to Improve the User Interface of the Alcohol Studies Database
No full textAcademic libraries are becoming more directly involved in the design and publishing of electronic information resources, including bibliographic databases, electronic journals, and digital archives. As a result, librarians are dealing with many user interface design issues that computer scientists and information specialists in other fields have encountered. Transaction log analysis can provide a rich source of information on user behavior and insights as to how user interfaces can be improved. This article describes the methodology and results of the log analysis for the Alcohol Studies Database (ASDB), a domain-specific database supported by the Center of Alcohol Studies and Rutgers University Libraries (RUL). The goals of this study were to better understand user search behavior, to analyze failure rates, and to develop approaches for improving the user interface.Peer reviewedThis article was published in College & Research Libraries, May 2003. The published version is open access and available at: http://crl.acrl.org/content/64/3/229.abstrac
Article by Ronald Atkins
No full textPhotocopied article by Ronald Atkins about new releases by Mike Westbrook, Chris McGregor, Wynton Marsalis, Chick Corea and Edward Wilkerson. The author describes shortly each recording
Unifying Frameworks for Library and Information Science: An Analysis of Three Perspectives
No full textThis article argues that there are emerging new roles for academic librarians and that a more focused discussion on the theoretical foundations of Library and Information Science (LIS) will provide guidance for both the discipline and the profession. The analysis herein examines a possible theoretical foundation or framework for LIS from three perspectives: the philosophy of information, social epistemology, and cybersemiotics. The primary advocates of these three perspectives are L. Floridi, J. Shera, and S. Brier respectively. This analysis addresses three questions: how does each perspective view LIS?, can the perspectives clarify the relationship between librarianship and information science, and can one of these perspectives suggest how the profession of academic librarianship should transform itself to meet the demands of the scholar in the 21st century? The analysis will proceed along four dimensions: a) knowledge and information, b) the focus on society and the individual, c) the meaning and structure of information, and d) how a unifying framework of LIS might deal with the practice of librarianship.Paper submitted for the course Communication, Information, and Media Processes (Professors Mokros, Kantor, and Pavlik), December 13, 2007
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