The Role of Indexing in Subject Retrieval

On first reading the list of speakers proposed for this institute, I became aware of being rather the "odd man out" for two reasons. Firstly, I was asked to present a paper on PRECIS which is very much a verbal indexing system-at a conference dominated by contributions on classification schemes with a natural bias, as the centenary year approaches, toward the Dewey Decimal Classification (DDC). Secondly, I feared (quite wrongly, as it happens) that I might be at variance with one or two of my fellow speakers, who would possibly like to assure us, in an age when we can no longer ignore the computer, that traditional library schemes such as DDC and Library of Congress Classification (LCC) are capable of maintaining their original function of organizing collections of documents, and at the same time are also well suited to the retrieval of relevant citations from machine-held files. In this context, I am reminded of a review of a general collection of essays on classification schemes which appeared in the Journal of Documentation in 1972. Norman Roberts, reviewing the papers which dealt specifically with the well established schemes, deduced that "all the writers project their particular schemes into the future with an optimism that springs, perhaps, as much from a sense of emotional involvement as from concrete evidence." Since I do not believe that these general schemes can play any significant part in the retrieval of items from mechanized files, it appeared that I had been cast in the role of devil's advocate.published or submitted for publicatio

Investigation of factors controlling the expression of molecules involved in neurite outgrowth

Nerve growth factor (NGF) induced morphological differentiation of the pheochromocytoma PC12 cell line is accompanied by cell surface modulation of the expression of specific cell surface recognition molecules. Changes in the relative expression of the Thy-1 glycoprotein, the neural cell adhesion molecule (N-CAM) and the LI antigen correlate with the onset of neuritic outgrowth indicating a role for these molecules in the neuritogenic process. NGF induced modulation of cell surface glycoprotein expression is, initially brought about by transcription dependent mechanisms, suggesting that the PC12 cell may be a suitable model for the investigation of primary signal transduction events. Studies utilising activators of adenylate cyclase and protein kinase C demonstrate that NGF induced differentiation events are mediated by a variety of independently acting transduction routes. Morphological and biochemical responses to NGF are sensitive to secondary cellular signals. Activators of adenylate cyclase acted synergistically with NGF to promote an accelerated phase of neuritic outgrowth while concomitantly causing differential modulation of NGF induced glycoprotein expression. Analysis of the morphological and biochemical status of PC12 cells grown on monolayer cultures of non-neuronal cells provided further evidence that responses to NGF are not immutable. While growth on myotubes and glioma cells provided permissible substrates for differentiation, PC12 cells grown on monolayers of skin fibroblasts failed to respond morphologically to NGF and in addition, NGF induced increases in the expression of neurofilament protein and the Thy-1 antigen were suppressed. The ability of primed PC12 cells to differentiate on fibroblast monolayers indicates that the inhibitory effects of fibroblast contact are directed at a component of primary, transcription dependent NGF-induced gene activation. Finally, the basic fibroblast growth factor (bFGF) was able to reproduce morphological and biochemical responses associated with NGF induced differentiation. A kinase inhibitor, K252a, was used to discriminate between responses induced by the two growth factors since its effects are specific for NGF

Electrical characterization of single-walled carbon nanotubes : leading toward electronic devices

This thesis presents research involving the electrical characterization of single-walled carbon nanotubes produced by the pulsed-laser vaporization technique. Carbon nanotubes were suspended in organic solvents and separated using ultrasonic excitation. The dispersed nanotubes were either physically deposited or spin-deposited onto electrode structures that were prefabricated using standard electron-beam lithography. Atomic force microscopy was used to locate and measure nanotubes that spanned across metal electrodes. Two-probe charge transport measurements were then made on these nanotube samples. The first sample exhibited current rectification, while many other carbon nanotubes were damaged by electrical breakdown. The effect of manipulating a nanotube at the electrode junction is also demonstrated. It was found that a potential barrier could be introduced, changing the I-V response of the nanotube device. Then, p-channel field-effect transistor behavior is shown for an individual single-walled carbon nanotube. Finally, an electrodeposition technique is presented for reducing the large contact resistance between a nanotube and the metal electrodes. This technique decreased the electrode-nanotube contact resistance by a factor of more than six, and maintained the semiconducting behavior of the nanotube. Energy band diagram models are used to try to explain some of the observed electronic properties

Coupling Analysis, Simulation, and Experimentation in Natural and Engineered Biological Systems at the Molecular Scale

Cellular functions are controlled by genetic regulatory networks called gene circuits. Recently, there has been much interest in how gene circuits deal with or even exploit stochastic fluctuations in molecular species within the cellular environment. Through a coupling of analysis and simulation with experimentation, this dissertation work furthers the understanding of gene circuit noise behavior and makes significant contributions to the analytical and experimental tools that are currently available for the study and design of natural and synthetic gene circuits. In this study, models are developed for unregulated and autoregulated gene circuits. Results from the analysis are compared to computer simulations and experimental results. Exact stochastic simulations show that the derived analytical expressions are valid even for populations as low as 10 molecules, despite linear approximations made by the analysis. The experimental portion of this work presents a novel method for acquiring in vivo measurements of real-time gene expression. The techniques developed here are used to report the very first measurements of frequency content in gene circuit noise and verify theoretical predictions that negatively autoregulated gene circuits shift their noise spectra up to higher frequency. Through measured shifts in noise spectra, these frequency measurements can also reveal subtle and condition-dependent regulatory pathways. Measured noise spectra may also permit in vivo estimation of gene circuit kinetic rate parameters

Expertise and Dynamics within Crowdsourced Musical Knowledge Curation: A Case Study of the Genius Platform

Many platforms collect crowdsourced information primarily from volunteers. As this type of knowledge curation has become widespread, contribution formats vary substantially and are driven by diverse processes across differing platforms. Thus, models for one platform are not necessarily applicable to others. Here, we study the temporal dynamics of Genius, a platform primarily designed for user-contributed annotations of song lyrics. A unique aspect of Genius is that the annotations are extremely local -- an annotated lyric may just be a few lines of a song -- but also highly related, e.g., by song, album, artist, or genre. We analyze several dynamical processes associated with lyric annotations and their edits, which differ substantially from models for other platforms. For example, expertise on song annotations follows a ``U shape'' where experts are both early and late contributors with non-experts contributing intermediately; we develop a user utility model that captures such behavior. We also find several contribution traits appearing early in a user's lifespan of contributions that distinguish (eventual) experts from non-experts. Combining our findings, we develop a model for early prediction of user expertise.Comment: 9 pages. 10 figure

Using VALiD to understand value from the stakeholder perspective

A “value agenda” has arisen in the UK’s cultural development in recent years. In the construction sector, a desire to make worthwhile building investments that are socially beneficial as well as commercially successful has become commonplace. This value agenda has become embodied in government policy which has, in turn, shaped the investment strategies of public bodies. Construction projects are becoming concerned with engaging directly with stakeholders to understand and reflect their attitudes, opinions and values in the final solution. In the private sector, the value agenda has stimulated business and societal debate to the stage where fulfilment of stakeholders’ expectations is seen as a precursor to commercial success. It is increasingly held that people seek to use buildings and facilities that reflect their values and which, therefore, they feel at ease with. In response to the above, VALiD (Value in Design) has been developed as a flexible framework that helps construction project teams explore and understand stakeholders’ values as a precursor to delivering value. Within this framework, VALiD defines value as the relationship of stakeholder benefits sought, sacrifices accepted, and resources expended. It is defined individually for every stakeholder in recognition that each has different underlying values and, therefore, a different perception of value. The use of VALiD to define project objectives and assess value delivery performance is described. The paper presents a summary of construction organisations’ response to this treatment of value, including the status of its development through continuing industry and academic research in the UK

Solving design problems to add value

Value management is well established in construction to structure early project briefing and to agree satisficing project values and objectives among project stakeholders. Current practice concentrates on the consideration of value during project definition. This paper proposes Integral Value Engineering as a design management practice that considers value in design throughout project resolution and delivery. An expansion of value management principles is proposed to include the adoption of a problem-solving approach and value-adding tools. These can help assemble value-adding frameworks in which design activity is more explicitly focused on project values. The use of problem solving frameworks to relate design method and outcome to project values is described and the notion of documenting these relationships to create a value-adding audit trail introduced. Integral Value Engineering is defined as the consideration of value when solving design problems, irrespective of the project stage in which they occur or their technical nature. The adaptability of the problem solving approach is discussed, together with its ability to accommodate the extensive variability in problem scope and concurrency in construction projects. The role of individual design engineers as practitioners of Integral Value Engineering is also described; this focuses on collaborative forums to incorporate the expertise of specialised suppliers. A web-based Value-Adding Toolbox is described to disseminate value-adding tool descriptions, methods and examples within a single organisation or managed value chain. The paper concludes that, for integral value engineering to be effective, suitable metrics must be identified to monitor the extent to which technical design solutions satisfy overall project values. This would allow responsive mechanisms to be defined so that design development can be managed throughout project duration to ensure that the satisficing values initially defined by value management at project outset will be delivered

Integral value engineering in design

Construction industry clients demand certainty in project cost, quality and time. The inability of traditionally composed design teams to consistently deliver this suggests that their expertise is sometimes inadequate. As clients become more dynamic in the next millennium, they are likely to demand greater certainty when construction projects are implemented to support frequent revisions in their short term function. By establishing a collaborative working framework it is proposed that supply chains can be better managed to identify and design out potential problems using integrated, collaborative design processes. This proposal is being investigated by the Integrated Collaborative Design (ICD) research project, a collaboration of AMEC Construction, Loughborough University and eleven supply organisations, supported by the EPSRC and DETR through the IDAC Link programme. Focusing on one component of the ICD project, this paper reviews existing, reactive, value engineering methods and by identifying their inadequacies establishes the need for an integrated approach. A value management context is described which integrates value engineering into continuous design processes. The paper discusses the opportunities for utilising supplier design expertise by modelling design process information flows. It also identifies potential cultural barriers to the use of design processes incorporating integral value engineering techniques and describes the linkage to other ICD components that are addressing these issues

Construction value management revisited: the designer's role

Value management is well established in construction. The method provides a structured, documentable consideration of project stakeholders to ensure that projects are required, framed to satisfy values and sufficiently supported by all stakeholders to ensure successful completion. A variety of construction-specific value management methods exist and many UK design management contractors offer the practice to clients as a structured method of considering the role of each project in adding value to clients’ business activities. Value management in construction has grown from the manufacturing sector, but historical review suggests it was extrapolated verbatim, with limited revision for construction application. The soundness of this foundation is examined. The paper reviews the extent to which designers are currently provided with mechanisms to consider stakeholder values during the project stages when most design output is produced. Integral Value Engineering is proposed to continuously relate ongoing design activity to the project values current at the time of each design task’s completion. The paper describes a toolbox of value-adding tools that provide project designers with methods of structuring design activity to relate technical design solutions to stakeholder values. Development of the toolbox as a web-based resource is reviewed, and its supporting role confirmed by validation exercises. The paper concludes by establishing the need for all designers in the supply chain to be provided with methods of structuring their problem solving processes to address value delivery, and the suitability of the value-adding toolbox to them. Future work must develop means of actively maintaining a shared understanding of values throughout project progression, providing a framework and objective for ongoing design activity