bluuebunny/crossref_metadata_2025 huggingface dataset:
Commercial security on the Internet
Authors: Liddy Carrie
Published: July 2002

There is a growing trend to delivering more efficient and more effective products and services with fewer and fewer resources. This trend is reflected in both the commercial and government sectors. The Internet is being viewed as the vehicle that could resolve many of these business delivery challenges. With the advent of public key security and certification, the transition from current business delivery to future Internet‐based systems is now possible. Deals with how public key cryptography may be used for business applications in the future, and also considers the theoretical applications of public key technology and certification processes. Examples of current technical solutions will be addressed in a future paper.
National (UK) Computer Security Survey 1996
Authors: Kearvell‐White Brian
Published: July 2002

Presents the UK survey of 15,000 finance directors in the UK and Ireland with annual turnovers of £10 million or more. States that the objective was to gain information about attitudes towards computer security and measures taken to secure information. Contains five headings: BS 7799; managing data; working with third parties; protecting the organization; and awareness and compliance. The sections covering BS 7799, managing data; and protecting the organization have been extracted.
Compassion in World Farming: an imaging and text retrieval case
Authors: Harrington Catherine
Published: July 2002

Discusses the issues associated with a surge in information demand in a relatively small organization. Introduces the idea of imaging and text retrieval to handle information demand. Discusses the criteria used by the Compassion in World Farming (CIWF) organization to make its decision on selecting a product. Presents situations in which use of the imaging and text retrieval system has had significant impact on the day‐to‐day conduct of business in the organization.
A model for the future of electronic commerce
Authors: Oliver Susan
Published: July 2002

Presents a discussion of traditional market segmentation in the context of the changing parameters of trade presented by electronic commerce. The discussion is based on two years of research by the director of an Australian futures research and scenario planning consultancy. Considers the three worlds of commerce labelled “marketplace”, “marketspace” and “customerspace”. Introduces and discusses the unprecedented business roles resulting from the intersections of these three worlds of commerce. Hypothesizes about the future of customer interrelationships based on these ways of trading and the emerging business roles. Highlights the major challenges to businesses for competing effectively in this future scenario.
Seamless secured transactions
Authors: Liddy Carrie , Sturgeon Alice
Published: July 2002

Discusses the requirements ‐ both technical and geopolitical ‐ for enabling seamless, secure transactions over the Internet. Discusses options in technical approaches, including trusted third party (TTP) and self‐signed certification authorities. Depicts the relevant layers of interactions each option entails. Explains the structures of proprietary keying systems and of hierarchical certification authorities. Addresses the geopolitical elements ‐ especially policy and procedures, and national legal frameworks ‐ required to effectively implement the trust that secure transactions require.
Database gateway processor risk analysis using fuzzy logic
Authors: Moscato Donald R.
Published: July 2002

Many large organizations maintain a significant amount of their data in what are currently referred to as legacy systems. In order to provide end users access to the firm’s legacy applications many organizations have opted to provide what is referred to as a database gateway system. An organization must be able to calculate its exposure in the event of a disaster occurring. Performance, recovery and monitoring considerations of the database gateway system have to be included in the risk analysis. The traditional approach to performing a risk analysis adheres to the procedure: identify the exposures or threats to the system; identify the assets at risk; determine the probability of the exposures happening; compute the expected loss for each asset and threat; consider the impact of existing controls; run a high/low analysis to determine the domain of risk exposure. Explains, in non‐technical terms, the basic concepts of the application of fuzzy logic modelling to risk analysis.
Industrial information‐weight security models
Authors: Portougal V. , Janczewski Lech J.
Published: July 2002

The paper discusses a set of models which can assist in developing security profiles of objects and subjects operating within industrial or commercial organisations’ databases. In these databases the information objects are often related to each other, having a hierarchical or even a network structure. A set of objects may be allowed to calculate other objects of a database. Security clearance must incorporate such possibilities.
Information and the nation: the 1997 Waigani Seminar
Authors: Evans John
Published: July 2002

This paper describes Papua New Guinea’s 1997 Waigani Seminar on Information and the Nation and the main themes: traditional knowledge; publications; sectoral information needs; human resources; and information and communication technology developments in Papua New Guinea. There is a summary of the main recommendations and of workshops run in association with the seminar.
A report on the Joint Symposium on Library and Information Science Studies, Zhongshan University, China, 29 March‐2 April 1998
Authors: Wing‐Ngao Heung
Published: July 2002

Reports on the first of two joint symposia to be held in South China during 1998. The Zhongshan University Symposium focused on library automation and networking, with six sessions on specific subthemes and 47 papers on such topics as information resources development and digital libraries, Internet information applications and services, resource sharing and regional cooperation. Participants at the symposium concluded that the standardisation of a Chinese encoding system to cater for all Chinese characters from China, Taiwan, Japan and Korea is a prerequisite for future cooperation and resource sharing. In addition, the panellists agreed that it is important to concentrate on developing library and information networks, especially using Internet technology and related resources.
The changing face of library and information science education in China in the 1990s
Authors: Tang Jinhong
Published: July 2002

This article investigates the renaming of departments of library and information science (LIS) in China in the 1990s. It analyses the technological, economic, social and government factors which affect education for LIS in contemporary China. Problems facing education for LIS in China are considered and suggestions made.
OSCAR at Ohio State University: a report
Authors: Henry Marcia
Published: July 2002

To access OSCAR use the following three steps: Type Telnet OSCAR.US.OHIO‐STATE/EDU
or Telnet 128. 146. 15. 27. Enter V for VT100. Enter Y to confirm. To exit: Enter N to reach main menu. Enter X at main menu.
Regional Web pages for OPACs: the New York State Electronic Doorway Library Network and British Library OPAC 97
Authors: Henry Marcia
Published: July 2002

Briefly describes two regional Web sites which offer links to OPACs ‐ the New York State Electronic Doorway Library Network and British Library OPAC 97.
“Doing it quickly”: use of a generic Web application platform for the rapid deployment of new services
Authors: McCleary John , Fladd Cara
Published: July 2002

With the Web sweeping through every aspect of campus services, how do you quickly deliver complex services without reinventing the wheel each time? The ability to quickly create support processes allows development staff to be more productive, and provides better service to clients. The use of collaborative development methodologies have been shown to be effective in the delivery of high customer satisfaction, fast prototyping of new services, and rapid deployment of operational processes. Discusses the aspects and benefits of rapidly developing and implementing Web‐based services with limited resources, and our success with tools that support collaborative development.
CyberInteractor ‐ a teaching and research tool
Authors: Bedell Louis R. , Somers Mark D.
Published: July 2002

An original computer‐based tool, dubbed CyberInteractor, is described. CyberInteractor is designed to facilitate immediate student feedback to an instructor and to other students in a classroom setting or via the World Wide Web. Feedback is saved in a database for educational research purposes. Students view a question that can include pictures, diagrams, a movie or sound clip, random numbers, and calculations involving the random numbers. After responding, they receive feedback showing how other students in the same class have responded. Newsgroups enable students to explain their reasoning. Instructors can give pre‐tests and post‐tests, and collect the answers and student discussions in files that can be analyzed later, thus facilitating the collection and processing of data from large numbers of students.
If you build it, will they come?
Authors: Kestner Neil , Hall Randall , Limbach Patrick , Butler Leslie
Published: July 2002

Describes how a core group of faculty built the Lucid Chemistry Web Site over four years and how students in large first and second year chemistry courses have started to use it (slowly at first, and now to near 100 percent participation in some classes). The facility has been developed for use by key administrative units (Testing and Evaluation, Computer Services). Now coming to the Lucid Chemistry Web Site are roughly one‐half of the chemistry department instructors and tenure‐track faculty. Asks whether the task of teaching needs more “builders”. Argues that more administrative involvement is needed with material creation and distribution. Will more users come? Yes, 100 percent participation by both teachers and students is a possibility. Mechanisms for achieving this goal are explored.
The constraints of providing a CD‐ROM‐based information service in a developing environment: a case study of the National Veterinary Research Institute Library, Vom
Authors: Jimba Samuel W. , Oladele Benedict A.
Published: July 2002

The introduction of information technologies in libraries is no longer a matter to be considered. Any library that has not implemented the use of these technologies to its services is considered outdated. The changes brought about by the convergence of computer and telecommunications technologies into the library has totally revolutionalized the nature of services. Unfortunately, libraries in the developing countries of the world are unable to keep up with these developments. Various problems are militating against the full implementation of technologies in these libraries. Analyzes these problems from a study of a veterinary library in Nigeria which uses a CD‐ROM to offer services to its clients. Makes suggestions and recommendations toward overcoming these problems in developing countries.
Internet‐based security incidents and the potential for false alarms
Authors: Evans M.P. , Furnell S.M.
Published: July 2002

The paper explains the background to experimental work that was conducted with the aim of measuring aspects of the WWW (specifically the average lifetime of a web link and the impact of the “Millennium Bug”), but which inadvertently caused two perceived security breaches on remote systems. The paper explains the nature of these incidents and considers why, when over 700,000 IP addresses were randomly sampled in the experimental study, only two sites considered the activity to be an attempt to breach their security. It is concluded that, while the appropriate protection of Internet‐based systems is undoubtedly of importance, the problems experienced during the experimental study suggest a lack of uniformity in what different organisations will class as a security breach.
Implications of the dynamics of the new networked economy for e‐business start‐ups: the case of Philips’ Access Point
Authors: Tovstiga George , Fantner Ernest J.
Published: July 2002

Explores how the spread of connectivity and the introduction of new standards is driving the emergence of entirely new value constructs that deliver to multiple stakeholders. Examines the new economics of network growth and the associated “economics of increasing returns”. Looks at the dynamic trajectory of this function from the perspective of new business development at the various stages of the trajectory, and derives management implications for each stage in terms of appropriate competitive and market strategies, organizational structure and management practices. Applies the resulting framework to discuss specific implications for the business start‐up of Access Point, Philips’ new multimedia, voice technology‐based information and on‐line services venture that has at its core a disruptive technology.
KIDSPHERE
Authors: Carlitz Robert D.
Published: July 2002

The KIDSPHERE mailing list is an online service which was created
to further the development of school networking. The growth of this
service has paralleled the rapid rise in the use of the Internet by
students and teachers in schools around the world. Describes the history
of KIDSPHERE, how the service is used, and what value it provides to its
subscribers. Services of this type play an important role in building a
community of educators on the Internet and in furthering the goals of
educational reform.
An overview of catalog design problems in resource discovery
Authors: Goodchild Andrew
Published: July 2002

Discusses some of the problems designers face in building catalogs in large networks and relates them back to the resource discovery problem. Currently many catalogs tend to be built in an ad hoc fashion ‐ which leads to a great variety in the quality of publicly accessible network catalogs. Furthermore, the research surrounding these catalogs tends to focus on narrow technical issues ‐ resulting in difficult‐to‐use catalogs. Addresses this problem by providing a usability framework based on the library science and human computer interaction literature, and demonstrates some of those principles via an example of a prototype. Results are interesting to resource discovery tool developers in that a framework for understanding the general resource discovery problem is provided and some techniques for dealing with those problems are presented.
Developing an intranet: tool selection and management issues
Authors: Chou David C.
Published: July 2002

Intranet adopts the same information technology that the Internet utilizes for network processing with the exception of system boundaries. Moving corporate systems onto an intranet environment will increase the data traffic within corporate network. In order to smooth out data traffic in the network, adopting a high‐quality management process to the intranet is needed. This article discusses the costs and benefits of adopting the intranet, tool availability and selection criteria, and some management issues for developing an intranet.
Investigating the future of Internet regulation
Authors: Westphal Heidemarie , Towell Elizabeth
Published: July 2002

The Internet, which began as a communication network controlled by the US Government, is a free and open international information superhighway. The number of Internet users and the variety of information found on the network have grown dramatically in the last decade. This rapid growth also occurred with minimal control of content or acceptable uses of the Internet. This study was designed to investigate the future of Internet regulation. Surveys were sent out to 510 Internet providers in 40 countries. Respondents indicated that some regulation may be necessary, but the cultural diversity in the world will make it difficult to implement.
Telecommunication and information infrastructures in the Botswana and SADC development strategy
Authors: Afullo Thomas J.O.
Published: July 2002

By 2016, Botswana aspires to triple its 1994 per capita income and to completely diversify its economic base. The Southern African Development Community (SADC) objectives, as spelt out in the SADC Policy document, emphasise the attainment of enhanced development and economic growth, poverty alleviation, and support of the socially disadvantaged through regional integration. Since telecommunications have long been recognised as the engine for economic growth, the aspirations of SADC and Botswana are consistent with the SADC Protocol on Transport, Communications, and Metrology, which aims at developing a reliable, efficient, vibrant, consumer‐driven telecommunications sector. We examine the focus of the World Bank and the International Telecommunications Union, in global telecommunications development. We then discuss the efforts of Botswana and other SADC states in ensuring that they take advantage of the private sector finances to build reliable, sophisticated public telecommunications networks for entry into the Global Information Infrastructure (GII).
Of teams and teambuilding
Authors: Kipp Michael F. , Kipp Mary Ann
Published: July 2002

In this article, the authors discuss the characteristics and dynamics of effective teams. They consider the factors influencing interpersonal interactions within a team and consequently propose that there is a variety of strategies which may be employed in any teambuilding initiative. The authors suggest a number of key points which they consider to be vital to any intervention to improve team effectiveness.
A review of executive teamwork
Authors: Luce Matthews Lauri
Published: July 2002

In the present review, top management groups (TMGs) are examined within the context of small group models and recent research studies. Differences and similarities among TMGs and other types of groups are highlighted. Five models of small groups are discussed. In this review, these models are summarized and organized using systems theory by identifying key inputs, processes, outcomes, and moderators for each model. Finally, key research conducted with TMGs, including demography, is examined and synthesized.
An early account of scientific management as applied to women’s work with comment by Frederick W. Taylor
Authors: Nyland Chris
Published: July 2002

The core of this paper is a reproduction of a study published in 1911 by Clark and Wyatt entitled “Scientific management as applied to women’s work”. The paper is significant because it provides a very early eyewitness “warts‐and‐all” account of scientific management as applied to women’s labor. It is also of interest because Frederick Taylor both read the work and corresponded with one of the authors. Hence it provides a rare insight into Taylor’s ideas regarding gender relations and the place of women in industry.
Is postmodern organization theory sceptical?
Authors: Weinstein Deena , Weinstein Michael A.
Published: July 2002

The practitioners of postmodern organization theory have had to respond to the charge that postmodernism has a declivity toward skepticism. Their response to organizational skepticisim is to decenter dominant theories, paradigms and organizational forms, rather than to negate them. Decentering supplements discourse by augmenting its repertoire; the opposite of skepticism, which diminishes its object. The main ways in which postmodern organization theories try to overcome the specific sceptical position of paradigm incommensurability (the reduction of discourse about organizations and organizational discourse to a solipsism of private language games) are described and assessed in terms of three positions: John Hassard’s “multiple paradigm” approach on the level of methodology, Stewart Clegg’s “embedded rationalities” on the level of empirical conceptualization, and Kenneth Gergen’s “heteroglossia” on the level of discursive practice. Hassard and Clegg are engaged in the mapping function of postmodern organization theory, whereas Gergen is engaged in deconstraining organizations.
Selective laser sintering of alumina with polymer binders
Authors: Subramanian Kamatchi , Vail Neal , Barlow Joel , Marcus Harris
Published: July 2002

The selective laser sintering (SLS) process is used to prepare test bars from Al2O3/polymer binder powders. Finds that binder‐coated A12O3 particles formed bars that were approximately twice as strong as could be formed from mixtures of alumina and polymer binder at the same binder level and processing conditions. In mixed systems, bar strengths increased nearly in proportion to increases in polymer binder content over the 20‐40 per cent volume binder range. Parts made in any particular laser scanning mode showed optimum values for strength and density as the laser energy density was systematically increased from 2‐8cal/cm2. Suggests that optima result from the counteracting influences of energy density on binder fusion and thermal degradation. The optimum energy density is mode or geometry sensitive and shifts to lower values as the laser scanning vector is reduced. Concludes that this behaviour is probably the result of the lower heat losses. Equivalently better utilization of laser energy is associated with the shorter scan vectors. Some of the SLS fabricated bars were infiltrated with colloidal alumina, fired to remove the binder, and sintered at 1,600°C to achieve alumina bars with 50 per cent relative densities, interconnected porosity, and strengths between 2 and 8MPa.
Viscosity analysis of photopolymer and glass‐fibre composites for rapid layered manufacturing
Authors: Zak G. , Chan A.Y.F. , Park C.B. , Benhabib B.
Published: July 2002

Refers to how the mechanical properties of polymer‐based composite objects produced via rapid layered fabrication methods can be improved significantly using short discontinuous fibres as reinforcements. Notes in this context, that the viscosity of the uncured fibre‐photopolymer composite liquids affects the raw‐material handling, the layer formation and the draining operations. Assesses the effects of aspect ratio, surface coating and volume fraction of short glass fibres on the viscosity of the fibre‐photopolymer composite liquids. Based on extensive experimentation and analysis, concludes that the shear viscosity of the composite liquids increases with increasing fibre‐volume fraction, showing that this effect is more pronounced at low shear rates than at high shear rates. Reveals, similarly, that the aspect ratio of the dispersed fibres has a stronger effect on the increase of viscosity at low shear rates and that the surface coating of the dispersed fibres also affects the viscosity of the composite liquids.
Investigation into the curing and thermal behavior of an epoxy‐based UV curable coating in microelectronics assembly
Authors: Fo Tsang Chi
Published: July 2002

UV curing processes of materials have to be specially designed accordingly in order to obtain the optimized property for different electronics applications. The purpose of this study is to characterize and study the curing and thermal behavior of a two‐component epoxy‐based UV curable coating in electronics assembly with various thermal analysis techniques. Curing behavioral change in terms of UV light, UV exposure time, wavelength, modulus, thermal stability, organic volatile outgassing and volume was discussed. Process optimization of coating materials that were UV cured at 30°, 100° and 150°C for 1 and 10 min was further investigated. Moreover, the relationship between photocuring conditions and the resultant surface hardness was studied and correlated from the results of dynamic microhardness measurements. Thermal and hardness properties of the above processed coating materials before and after isopropyl alcohol saturation were also investigated.
A simple modification of a flip‐chip bonder to allow large area chip attach
Authors: Fuchs S. , Rindelhardt K. , Barrett J. , Stam F.
Published: July 2002

Describes the modification of a laboratory flip‐chip bonder to allow bonding of very large chips. The original optical system of the bonder was designed for chip sizes up to 5.0 ¥ 5.0mm2. It was desired to use the system for bonding chips larger than this, up to 23.0 ¥ 23.0mm2. Therefore a modification of the existing system was needed. Several options for purely optical modifications were identified and investigated. It was concluded that all optical solutions considered were not feasible because of either size or cost. Therefore attention was directed to a “mechanical solution”. The system was modified using a guide‐rail to move the microscope along the chip diagonally. It was proven that this works reliably for any size of chip. The overall costs of this solution are relatively low. It can be easily implemented for this type of bonder, which is widely used in laboratory flip‐chip research.
Assembly and reliability of flip chip on boards using ACAs or eutectic solder with underfill
Authors: Zhong Zhaowei
Published: July 2002

Reports the research and development results on flip chip on FR‐4 and ceramics, using anisotropic conductive film (ACF), anisotropic conductive paste (ACP), or eutectic solder with underfill. Several types of ACF and ACP with different types of conductive particles and adhesives were investigated. Simple but high yield procedures for reworking flip chip on board using ACP and ACF were developed. Processes for flip chip on FR‐4 and ceramic boards using eutectic solder bumps with underfill were also evaluated. The flip chips were assembled on test vehicles for temperature cycling and high‐temperature high‐humidity tests. The reliability performance of the three processes (gold bumps with ACF, gold bumps with ACP, and eutectic solder bumps with underfill) is compared.
A two‐stage process for eliciting and prioritising critical knowledge
Authors: Preiss Kenneth J.
Published: July 2002

An overview of knowledge elicitation, representation and prioritisation of key performance indicators (CSFs) necessary for success in direct selling in a dynamic market on a woman‐to‐woman basis is presented. The CSFs were elicited using the Repertory Grid (RepGrid) method. The RepGrid method allows for construct elicitation and the exploration of constructing indices, such as, frame differentiation, frame complexity, frame integration and construct centrality. The CSF constructs are then prioritised using the Analytic Hierarchic Process. The proposed two‐stage methodology offers the benefit of eliciting individual mental constructs about critical knowledge, the representation of those constructs in a meaningful form, and the representation of repositories of knowledge of multiple entities across and within organisations.
The National Biological Information Infrastructure: coming of age
Authors: Cotter Gladys , Frame Mike , Sepic Ron , Zolly Lisa
Published: July 2002

Coordinated by the US Geological Survey, the National Biological Information Infrastructure (NBII) is a Web‐based system that provides increased access to data and information on the nation’s biological resources. The NBII can be viewed from a variety of perspectives. This article – an individual case study and not a broad survey with extensive references to the literature – addresses the structure of the NBII related to thematic sections, infrastructure sections and place‐based sections, and other topics such as the Integrated Taxonomic Information System (one of our more innovative tools) and the development of our controlled vocabulary.
Designed heterodimerizing leucine zippers with a ranger of pIs and stabilities up to 10−15 M
Authors: Moll Jonathan R. , Ruvinov Sergei B. , Pastan Ira , Vinson Charles
Published: July 2002

We have designed a heterodimerizing leucine zipper system to target a radionuclide to prelocalized noninternalizing tumor‐specific antibodies. The modular nature of the leucine zipper allows us to iteratively use design rules to achieve specific homodimer and heterodimer affinities. We present circular‐dichroism thermal denaturation measurements on four pairs of heterodimerizing leucine zippers. These peptides are 47 amino acids long and contain four or five pairs of electrostatically attractive g ↔ e′ (i, i′ +5) interhelical heterodimeric interactions. The most stable heterodimer consists of an acidic leucine zipper and a basic leucine zipper that melt as homodimers in the micro (Tm = 28°C) or nanomolar (Tm = 40°C) range, respectively, but heterodimerize with a Tm >90°C, calculated to represent femtamolar affinities. Modifications to this pair of acidic and basic zippers, designed to destabilize homodimerization, resulted in peptides that are unstructured monomers at 4 μM and 6°C but that heterodimerize with a Tm = 74°C or Kd(37) = 1.1 × 10−11 M. A third heterodimerizing pair was designed to have a more neutral isoelectric focusing point (pI) and formed a heterodimer with Tm = 73°C. We can tailor this heterodimerizing system to achieve pharmacokinetics aimed at optimizing targeted killing of cancer cells.
Epitope mapping of a monoclonal antibody against human thrombin by H/D‐exchange mass spectrometry reveals selection of a diverse sequence in a highly conserved protein
Authors: Baerga‐Ortiz Abel , Hughes Carrie A. , Mandell Jeffrey G. , Komives Elizabeth A.
Published: July 2002

The epitope of a monoclonal antibody raised against human thrombin has been determined by hydrogen/deuterium exchange coupled to MALDI mass spectrometry. The antibody epitope was identified as the surface of thrombin that retained deuterium in the presence of the monoclonal antibody compared to control experiments in its absence. Covalent attachment of the antibody to protein G beads and efficient elution of the antigen after deuterium exchange afforded the analysis of all possible epitopes in a single MALDI mass spectrum. The epitope, which was discontinuous, consisting of two peptides close to anion‐binding exosite I, was readily identified. The epitope overlapped with, but was not identical to, the thrombomodulin binding site, consistent with inhibition studies. The antibody bound specifically to human thrombin and not to murine or bovine thrombin, although these proteins share 86% identity with the human protein. Interestingly, the epitope turned out to be the more structured of two surface regions in which higher sequence variation between the three species is seen.
α1H mRNA in single skeletal muscle fibres accounts for T‐type calcium current transient expression during fetal development in mice
Authors: Berthier Christine , Monteil Arnaud , Lory Philippe , Strube Caroline
Published: July 2002

Calcium channels are essential for excitation‐contraction coupling and muscle development. At the end of fetal life, two types of Ca2+ currents can be recorded in muscle cells. Whereas L‐type Ca2+ channels have been extensively studied, T‐type channels have been poorly characterized in skeletal muscle. We describe here the functional and molecular properties of T‐type calcium channels in developing mouse skeletal muscle. The T‐type current density increased transiently during prenatal myogenesis with a maximum at embryonic day E16 followed by a drastic decrease until birth. This current showed similar electrophysiological and pharmacological properties at all examined stages. It displayed a wide window current centred at about −35 and −55 mV in 10 and 2 mm external Ca2+, respectively. Activation and inactivation kinetics were fast (3 and 16 ms, respectively). The current was inhibited by nickel and amiloride with an IC50 of 5.4 and 156 μm, respectively, values similar to those described for cloned T‐type α1H channels. Whole muscle tissue RT‐PCR analysis revealed mRNAs corresponding to α1H and α1G subunits in the fetus but not in the adult. However, single‐fibre RT‐PCR demonstrated that only α1H mRNA was present in prenatal fibres, suggesting that the α1G transcript present in muscle tissue must be expressed by non‐skeletal muscle cells. Altogether, these results demonstrate that the α1H subunit generates functional T‐type calcium channels in developing skeletal muscle fibres and suggest that these channels are involved in the early stages of muscle differentiation.
Quantification of the response of rat medullary raphe neurones to independent changes in pHo and PCO2
Authors: Wang Wengang , Bradley Stefania Risso , Richerson George B.
Published: July 2002

The medullary raphe nuclei contain putative central respiratory chemoreceptor neurones that are highly sensitive to acidosis. To define the primary stimulus for chemosensitivity in these neurones, the response to hypercapnic acidosis was quantified and compared with the response to independent changes in PCO2 and extracellular pH (pHo). Neurones from the ventromedial medulla of neonatal rats (P0‐P2) were dissociated and maintained in tissue culture for long enough to develop a mature response (up to 70 days). Perforated patch clamp recordings were used to record membrane potential and firing rate while changes were made in pHo, PCO2 and/or [NaHCO3]o from baseline values of 7.4, 5 % and 26 mm, respectively. Hypercapnic acidosis (PCO2 9 %; pHo 7.17) induced an increase in firing rate to 285 % of control in one subset of neurones (‘stimulated neurones’) and induced a decrease in firing rate to 21 % of control in a different subset of neurones (‘inhibited neurones’). Isocapnic acidosis (pHo 7.16; [NaHCO3]o 15 mm) induced an increase in firing rate of stimulated neurones to 309 % of control, and a decrease in firing rate of inhibited neurones to 38 % of control. In a different group of neurones, isohydric hypercapnia (9 % PCO2; [NaHCO3]o 40 mm) induced an increase in firing rate of stimulated neurones by the same amount (to 384 % of control) as in response to hypercapnic acidosis (to 327 % of control). Inhibited neurones also responded to isohydric hypercapnia in the same way as they did to hypercapnic acidosis. In Hepes‐buffered solution, both types of neurone responded to changes in pHo in the same way as they responded to changes in pHo in bicarbonate‐buffered Ringer solution. It has previously been shown that all acidosis‐stimulated neurones in the medullary raphe are immunoreactive for tryptophan hydroxylase (TpOH‐ir). Here it was found that TpOH‐ir neurones in the medullary raphe were immunoreactive for carbonic anhydrase type II and type IV (CA II and CA IV). However, CA immunoreactivity was also common in neurones of the hypoglossal motor nucleus, inferior olive, hippocampus and cerebellum, indicating that its presence is not uniquely associated with chemosensitive neurones. In addition, under the conditions used here, acetazolamide (100 μm) did not have a significant effect on the response to hypercapnic acidosis. We conclude that chemosensitivity of raphe neurones can occur independently of changes in pHo, PCO2 or bicarbonate. The results suggest that a change in intracellular pH (pHi) may be the primary stimulus for chemosensitivity in these putative central respiratory chemoreceptor neurones.
Lamina‐specific membrane and discharge properties of rat spinal dorsal horn neurones in vitro
Authors: Ruscheweyh Ruth , Sandkühler Jürgen
Published: July 2002

Membrane and discharge properties determine the input‐output relationship of neurones and are therefore of paramount importance for the functions of neural circuits. Here, we have tested the hypothesis that neurones in different laminae of the spinal dorsal horn differ in their electrophysiological properties. Whole‐cell patch‐clamp recordings from dorsal horn neurones in a rat transverse spinal cord slice preparation were used to record active and passive membrane properties. Neurones from superficial dorsal horn laminae had higher membrane resistances and broader action potentials than deep dorsal horn neurones. Action potential thresholds were highest in lamina II neurones, representing low membrane excitability. Five types of firing patterns were identified in response to depolarising current injections. Tonic‐firing neurones discharged action potentials at regular intervals throughout the current pulse. Delayed‐firing neurones showed a delayed onset of firing in response to current injections that was due to activation of a transient voltage‐dependent outward current, presumably an A‐current. Another group of neurones fired a short initial burst of action potentials. Single‐spiking neurones discharged only one action potential at the onset of a depolarising pulse. Phasic‐bursting neurones showed irregular bursts of action potentials. Firing patterns were unequally distributed among laminae. Tonic‐firing neurones were numerous in lamina I and deeper laminae but were not found in lamina II. Delayed‐firing neurones were encountered in laminae I and II but not in deeper laminae. Most of the neurones showing an initial burst were found in lamina II. These differences in membrane and discharge properties probably contribute to lamina‐specific processing of sensory, including nociceptive, information.
An Equivalent Mean Day Calculation to Predict Monthly Average Daily Utilizability for Flat Plate Collectors
Authors: Satyamurty V. V. , Babu K. Sarath , Lahiri P. K.
Published: July 2002

An equivalent mean day for the calculation of monthly average daily utilizability is proposed in the present article. The equivalent mean day is characterized by a clearness index equal to the average of the clearness indices of the days that contribute to the useful energy. It has been shown that the monthly average daily utilizability can be calculated from the utilizability calculated for a single day, the equivalent mean day. The method has been validated for flat plate collectors of general orientation with extensive comparisons. [S0199-6231(00)00402-0]
Physiological Flow Simulation in Residual Human Stenoses After Coronary Angioplasty
Authors: Banerjee Rupak K. , Back Lloyd H. , Back Martin R. , Cho Young I.
Published: July 2002

To evaluate the local hemodynamic implications of coronary artery balloon angioplasty, computational fluid dynamics (CFD) was applied in a group of patients previously reported by [Wilson et al. (1988), 77, pp. 873–885] with representative stenosis geometry post-angioplasty and with measured values of coronary flow reserve returning to a normal range (3.6±0.3). During undisturbed flow in the absence of diagnostic catheter sensors within the lesions, the computed mean pressure drop Δp˜ was only about 1 mmHg at basal flow, and increased moderately to about 8 mmHg for hyperemic flow. Corresponding elevated levels of mean wall shear stress in the midthroat region of the residual stenoses, which are common after angioplasty procedures, increased from about 60 to 290 dynes/cm2 during hyperemia. The computations (Re˜e≃100-400;αe=2.25) indicated that the pulsatile flow field was principally quasi-steady during the cardiac cycle, but there was phase lag in the pressure drop−mean velocity Δp−u¯ relation. Time-averaged pressure drop values, Δp˜, were about 20 percent higher than calculated pressure drop values, Δps, for steady flow, similar to previous in vitro measurements by Cho et al. (1983). In the throat region, viscous effects were confined to the near-wall region, and entrance effects were evident during the cardiac cycle. Proximal to the lesion, velocity profiles deviated from parabolic shape at lower velocities during the cardiac cycle. The flow field was very complex in the oscillatory separated flow reattachment region in the distal vessel where pressure recovery occurred. These results may also serve as a useful reference against catheter-measured pressure drops and velocity ratios (hemodynamic endpoints) and arteriographic (anatomic) endpoints post-angioplasty. Some comparisons to previous studies of flow through stenoses models are also shown for perspective purposes. [S0148-0731(00)00304-6]
Shell Stability Related to Pattern Formation in Plants
Authors: Steele C. R.
Published: July 2002

In the last few years we have studied the possible relation of instability of a shell surface to the patterns that develop in plants. In the present work, it is found that there is a linear relation between the epidermis (tunica) thickness and the wavelength between new leaves (primordia). This relation is near the buckling wavelength calculated from the geometry of the tunica and interior (corpus) cells. The main focus is on the changes in pattern that occur. (1) The wild variety of snapdragon has primordia that bulge out of plane, while a mutant has in-plane folding. A crude mechanical model is an elastic ring constrained at the outer diameter and subjected to uniform growth, represented by thermal expansion. It is found that the difference in the in-plane and out-of-plane buckling can be accounted for by a modest change in one geometric parameter. (2) The second change is that in the unicellular alga Acetabularia. The geometry consists of a standard cylindrical pressure vessel with a nearly hemispherical end cap. At a point in time, the end cap flattens and a uniform circumferential array of new shoots forms. A mechanical model for the growth is proposed, in which the wall consists of a viscous material with a locally linear relation between mean stress and creep (growth) rate. The result is that the elliptical shape for stable growth can be regulated by one parameter of viscosity. The results reinforce the suggestion that the stability of the surface is instrumental in the generation of plant patterns, and that substantial change in pattern can be controlled by the modification of few mechanical parameters. [S0021-8936(00)03002-6]
Quasi-Static Propagation of Subinterfacial Cracks
Authors: Lee H. , Krishnaswamy S.
Published: July 2002

The problem of quasi-static crack propagation in a three-point bend specimen containing an initial crack that is parallel to and offset from a bimaterial interface is considered. An approximate dislocation-based fracture model is used to identify conditions under which such cracks are attracted to or repelled by the interface. Possible configurations (material/geometry) where such subinterfacial cracks experience pure mode I conditions are determined. Experimental results are presented showing quasi-static crack propagation of subinterfacial cracks for three regimes: (attractive) into the interface; (repulsive) away from the interface; as well as (equilibrium) parallel to the interface. [S0021-8936(00)01903-6]
The Kinematics of Wheat Struck by a Wind Gust
Authors: Farquhar T. , Wood J. Z. , van Beem J.
Published: July 2002

A nonlinear model of the kinematics of a wheat stalk struck by a wind gust is developed. Individual stalks were excited from each of many directions and observed by videophotography. The underdamped flexural response involved anisotropic circling motion that can be reproduced by a nonlinear system of ODEs. In the model, the horizontal path traveled by the grain mass is described in principal coordinates XI and XII. The four required constants are stiffnesses kI<kII in these directions, linear viscous damping ζ, and coupling strength β related to a torque imposed by wind drag. This stem torque can cause nonlinear coupling if both XI and XII are excited and if kI≠kII, such that damping can vary by 30 percent over each cycle. The directionality of the single stalk may promote interplant collision, which could have important integrated effects on crop behavior at larger size scales. [S0021-8936(00)02303-5]
Image Singularity System to Represent Two Circular Cylinders of Different Diameter
Authors: Lee D. K.
Published: July 2002

The singularity system to represent two circular cylinders poised under different ambient flow fields is considered in the present research. The singularity system, composed of a series of singularities, has to be truncated for numerical calculations. A rational criterion to determine how many terms of this series should be retained to maintain the prescribed accuracy is provided through analysis of the converging property of the series. A particular emphasis is put on how to deal with the discrete vortex model of a boundary layer, this possibility being the basis for the development of a tool to simulate vortex shedding from a structure composed of two circular cylinders. The principle in obtaining the present singularity system can be applied to more-than-two-cylinders structures. Only the series becomes more complex with an increase in the number of cylinders. [S0098-2202(00)01704-1]
Real-Time Implementation of Sliding Mode Observer for Synchronous Rectification of the Automotive Electrical Power Supply System
Authors: Chen De-Shiou , Utkin Vadim I. , Zarei Shahram , Miller John M.
Published: July 2002

This paper presents the methods for estimating automotive alternator’s back electromotive forces without a direct mechanical sensor of the rotor position. The design approach combines the merits of the sliding mode observer technique with the basics of a conventional observer. It is shown that the back electromotive forces may be observed based on system’s phase current model by sensing only electrical variables of the synchronous rectifier. Experimental results are presented for validation of the proposed observation algorithms. [S0022-0434(00)01404-0]
Improved Bilinear Routh Approximation Method for Discrete-Time Systems
Authors: Choo Younseok
Published: July 2002

Hwang and Shieh proposed a bilinear Routh approximation method for reducing the order of discrete-time systems. A reduced model derived by the method is not only stable whenever an original model is stable, but also fits the first few time-moments of the original one. This paper addresses the possibility of improving the method by letting the impulse response energy of the original model also be conserved in the reduced model without destroying the stability preserving and time-moments matching properties.
Comparison of and Discrepancies Between TMY and TMY2S Predictions for Simple Photovoltaic and Wind Energy Simulations
Authors: Massie Darrell D. , Kreider Jan F.
Published: July 2002

A new typical meteorological year (TMY2s) data set has been derived from the 1961–1990 National Solar Radiation Data Base (NSRDB). This paper compares PV and wind energy system simulation results using new TMY2s data with results using the original TMY data set. PV and aerogenerator simulations are compared in seven different climatic regions of the United States. Results indicate that PV simulations using TMY2s data provide higher energy values for cloudy regions where the clearness index is low and lower energy values for sunnier climates. TMY2s wind simulations produce lower energy predictions in nearly all cases tested.
High-Temperature Reliability of Advanced Ceramics
Authors: Ohji Tatsuki
Published: July 2002

This paper describes high-temperature reliability, particularly creep and creep rupture behavior of three engineering ceramics—silicon nitride, silicon carbide, and alumina-based silicon-carbide-particulate ceramics—which are considered the most potential candidates for the use of blades of high-efficiency ceramic gas turbine. The structural reliability of silicon nitride is very often limited due to the softening of glassy phases formed at grain boundaries. On the other hand, silicon carbide, which generally does not contain glassy phase at the grain boundaries, shows excellent creep resistance even at very high temperatures. Finally, it is shown that creep resistance of alumina can be markedly improved by dispersing nano-sized silicon carbide particles into the grain boundary.