bluuebunny/crossref_metadata_2025 huggingface dataset:
The following is the abstract of the article discussed in the subsequent letter:
Authors: Silber Jeffrey H.
Published: November 2004

Wall stress, although commonly used as an index of afterload, fails to take into account forces generated within the wall of the left ventricle (LV) that oppose systolic fiber shortening. Wall stress may, therefore, misrepresent fiber stress, the force resisting fiber shortening, particularly in the presence of an abnormal LV thickness-to-dimension ratio ( h/ D). M-mode LV echocardiograms were obtained from 207 patients with a wide range of values for LV mass and/or h/ D. Diagnoses were valvar aortic stenosis, coarctation repair, anthracycline treated, and severe aortic and/or mitral regurgitation. End-systolic wall stress (WSes) and fiber stress (FSes) were expressed as age-corrected Z scores relative to a normal population. The difference between WSes and FSes was extreme when h/ D was elevated or reduced [WSes Z score − FSes Z score = 0.14 × ( h/ D)−1.47 − 2.13; r = 0.78, P < 0.001], with WSes underestimating FSes when h/ D was increased and overestimating FSes when h/ D was decreased. Analyses of myocardial mechanics based on wall stress have limited validity in patients with abnormal ventricular geometry.
Canal–Otolith Interactions After Off-Vertical Axis Rotations. II. Spatiotemporal Properties of Roll and Pitch Postrotatory Vestibuloocular Reflexes
Authors: Hess Bernhard J. M. , Jaggi-Schwarz Karin , Misslisch Hubert
Published: November 2004

We have examined the spatiotemporal characteristics of postrotatory eye velocity after roll and pitch off-vertical axis rotations (OVAR). Three rhesus monkeys were placed in one of 3 orientations on a 3-dimensional (3D) turntable: upright (90° roll or pitch OVAR), 45° nose-up (45° roll OVAR), and 45° left ear-down (45° pitch OVAR). Subjects were then rotated at ±60°/s around the naso-occipital or interaural axis and stopped after 10 turns, in one of 7 final head orientations, each separated by 30°. We found that postrotatory eye velocity showed horizontal–vertical components after roll OVAR and horizontal–torsional components after pitch OVAR that varied systematically as a function of final head orientation. The quantitative analysis suggests that, in contrast to the analogous yaw OVAR paradigm, a system of up to 3 real, gravity-dependent eigenvectors and eigenvalues determines the spatiotemporal characteristics of the residual eye velocities after roll and pitch OVAR. One of these eigenvectors closely aligned with gravity, whereas the other 2 determined the orientation of the earth horizontal plane. We propose that the spatial characteristics of eye velocity after roll and pitch OVAR follow the physical constraints of stationary orientation in a gravitational field and reflect the brain’s best estimate of head-in-space orientation within an internal representation of 3D space.
Vestibular Gaze Stabilization: Different Behavioral Strategies for Arboreal and Terrestrial Avians
Authors: Haque Asim , Dickman J. David
Published: November 2004

In birds, it is thought that head movements play a major role in the reflexive stabilization of gaze and vision. In this study, we investigated the contributions of the eye and head to gaze stabilization during rotations under both head-fixed [vestibuloocular (VOR)] and head-free conditions in two avian species: pigeons and quails. These two species differ both in ocular anatomy (the pigeon has 2 distinct foveal regions), as well as in behavioral repertoires. Pigeons are arboreal, fly extended distances, and can navigate. Quails are primarily engrossed in terrestrial niches and fly only short distances. Unlike the head-fixed VOR gains that were under-compensatory for both species, gaze gains under head-free conditions were completely compensatory at high frequencies. This compensation was achieved primarily with head movements in pigeons, but with combined head and eye-in-head contributions in the quail. In contrast, eye-in-head motion, which was significantly reduced for head-free compared with head-fixed conditions, contributed very little to overall gaze stability in pigeons. These results suggest that disparity between the stabilization strategies employed by these two birds may be attributed to differences in species-specific behavior and anatomy.
Single-Column Thalamocortical Network Model Exhibiting Gamma Oscillations, Sleep Spindles, and Epileptogenic Bursts
Authors: Traub Roger D. , Contreras Diego , Cunningham Mark O. , Murray Hilary , LeBeau Fiona E. N. , Roopun Anita , Bibbig Andrea , Wilent W. Bryan , Higley Michael J. , Whittington Miles A.
Published: November 2004

To better understand population phenomena in thalamocortical neuronal ensembles, we have constructed a preliminary network model with 3,560 multicompartment neurons (containing soma, branching dendrites, and a portion of axon). Types of neurons included superficial pyramids (with regular spiking [RS] and fast rhythmic bursting [FRB] firing behaviors); RS spiny stellates; fast spiking (FS) interneurons, with basket-type and axoaxonic types of connectivity, and located in superficial and deep cortical layers; low threshold spiking (LTS) interneurons, which contacted principal cell dendrites; deep pyramids, which could have RS or intrinsic bursting (IB) firing behaviors, and endowed either with nontufted apical dendrites or with long tufted apical dendrites; thalamocortical relay (TCR) cells; and nucleus reticularis (nRT) cells. To the extent possible, both electrophysiology and synaptic connectivity were based on published data, although many arbitrary choices were necessary. In addition to synaptic connectivity (by AMPA/kainate, NMDA, and GABAAreceptors), we also included electrical coupling between dendrites of interneurons, nRT cells, and TCR cells, and—in various combinations—electrical coupling between the proximal axons of certain cortical principal neurons. Our network model replicates several observed population phenomena, including 1) persistent gamma oscillations; 2) thalamocortical sleep spindles; 3) series of synchronized population bursts, resembling electrographic seizures; 4) isolated double population bursts with superimposed very fast oscillations (>100 Hz, “VFO”); 5) spike-wave, polyspike-wave, and fast runs (about 10 Hz). We show that epileptiform bursts, including double and multiple bursts, containing VFO occur in rat auditory cortex in vitro, in the presence of kainate, when both GABAAand GABABreceptors are blocked. Electrical coupling between axons appears necessary (as reported previously) for persistent gamma and additionally plays a role in the detailed shaping of epileptogenic events. The degree of recurrent synaptic excitation between spiny stellate cells, and their tendency to fire throughout multiple bursts, also appears critical in shaping epileptogenic events.
Numerical Investigations of Perforated Laminates in the Presence of Residual Ply Stresses
Authors: Pahr D. H. , Schuecker C. , Rammerstorfer F. G. , Pettermann H. E.
Published: November 2004

Finite element-based first-ply failure strength investigations of perforated laminates in the presence of residual ply stresses are presented. Unitcell models are applied, where inter-and intra-laminar failures as well as free-edge effects are taken into account on the ply level. The critical stress states contain constant and variable stress parts, which mean that nonradial loading paths are considered. Failure envelopes are computed for different layups and residual stress levels. This way the strength evaluation of structures containing perforated laminates can be performed on the macroscopic, i.e. structural, level.
Ballistic Penetration of Conically Cylindrical Steel Projectile into Plain-woven Fabric Target – A Finite Element Simulation
Authors: Gu Bohong
Published: November 2004

This paper gives a finite element model to simulate the entire process of multilayered fabric target perforated by conically cylindrical steel projectile on the basis of the description of the actual structure of fabric considering crimps of warp and weft yarns. Commercially available finite element code Ls-Dyna is incorporated with the Weibull constitutive equations of filament yarns at high strain rate to simulate the ballistic impact response. The projectile and yarns in the fabric are meshed with a eight-node hexahedron element (Solid 164 in Ls-Dyna). From the comparisons of the residual velocities of the projectile, and deformation and damages of the fabric target after ballistic perforation between the experimental results and theoretical ones, it is proven that at the yarn-structural hierarchy, the finite element method with explicit algorithm and code Ls-Dyna could precisely simulate the ballistic impact between the steel projectile and the fabric target. It is also found from calculations that only when the mechanical properties and constitutive equations at a high strain rate are adopted in the finite element model, can the precision of simulation be improved. An interesting and nonintuitive result is that the existence of fabric interspaces between the interweaved yarns could not decrease the kinetic energy absorptions of the fabric target perforated by the projectile under the ballistic impact. The original ideas of this paper are the considerations of the actual structure of multilayered fabric target and the constitutive equations of yarns at a high strain rate in the finite element model. Compared with other papers in this field, the FEM model proposed in this paper can simulate the interaction between the projectile and the multilayered fabric target more precisely in fabric target deformation, kinetic energy absorption, and strain wave distribution. This model can also be extended to other fabric structures and materials under the ballistic impact.
The Pakistan Water Knowledge Network
Authors: Zaman Asad Uz
Published: November 2004

Paper presented at the Sixth Water Information Summit: Breaking The Barriers Let Water Information Flow! Waterweb Consortium and IRC International Water and Sanitation Centre September 9-12 Delft, The Netherlands 2003. Describes the aims and functions of the Pakistan Water Gateway (PWG), a one stop website for all water related information pertaining to Pakistan. The Gateway is envisioned as the first step towards the development of a Pakistan Water Knowledge Network that will complement the efforts of federal and provincial government departments and water institutes and ultimately function as a digital bridge between national and international networks of governments and water related non-government groups, facilitate capacity building and raise awareness about water issues. Key features include: content in local languages; online monthly newsletter; knowledge base of water sector organizations in Pakistan; research abstracts and papers; calendar of events; experts directory; experts group; feedback system; employment opportunities; online forums; e-learning; emerging portals.
Rio de la Plata and its Maritime Front Environmental Information System and Portal: tools used and lessons learned
Authors: Himschoot Patricia Hilda , Fernández Virginia , Arciet Juan , Goldsmidt Viviana , Fabricant Jorge
Published: November 2004

Paper presented at the Sixth Water Information Summit: Breaking The Barriers Let Water Information Flow! Waterweb Consortium and IRC International Water and Sanitation Centre September 9-12 Delft, The Netherlands 2003. Describes the aims, development and functions of the Integrated Information System of the FREPLATA Project and the creation of the Rio de la Plata and its Maritime Front Portal, a cooperative Internet gateway to environmental and spatial information on the Rio de Plata region. The FREPLATA project is a cooperative activity of 18 institutions in Argentina and Uruguay. The Project and institutions with suitably trained personnel designed, developed and implemented databases, applications and standards which enable the systematization of information and constitute tools for management and decision-making.
Building the Capacity of NGOs and CBOs in Uganda through Information
Authors: Nafula Caroline Batanda
Published: November 2004

Paper presented at the Sixth Water Information Summit: Breaking The Barriers Let Water Information Flow! Waterweb Consortium And IRC International Water and Sanitation Centre September 9-12 Delft, The Netherlands 2003. Focuses on the ways in which the Uganda Water and Sanitation NGO Network (UWASNET) is attempting to bridge the information gap between non-governmental organizations (NGOs), communirty-based organizations (CBOs) and other water and sanitation sector stakeholders at local, regional and international levels. Highlights how appropriate information is disseminated to UWASNET members and discusses the value of information collection and dissemination and how these are used to build the capacity of members. Concludes that, through sharing and learning from others, NGOs can start to think ‘outside the box’ and thus exploit the enormous potential of increasing the knowledge base of their organizations.
Sanicon: an Internet portal for information on sanitation
Authors: Odhiambo Frank
Published: November 2004

Paper presented at the Sixth Water Information Summit: Breaking The Barriers Let Water Information Flow! Waterweb Consortium and IRC International Water and Sanitation Centre September 9-12 Delft, The Netherlands 2003. Presents a case study of the aims, development and functioning of Sanitation Connection (Sanicon) an Internet subject gateway for sanitation information. Considers aspects of Internet portals in general and the issue of information overload. Discusses the reasons for the development of Sanicon and its main design features, the usage of Internet resources, the tools available for measuring usage and the limitations of usage statistics. Considers the different ways in which content is selected and presented in Sanicon, the arrangements for editorial direction and the financial resources required for such an initiative. Presents the issues to be considered in planning an Internet-based subject gateway based on the Sanicon experience.
The Southern Africa Water Information Network - SAWINET: a case study on sharing information and experience on integrated water resources management in Southern Africa
Authors: Takawira Andrew
Published: November 2004

Paper presented at the Sixth Water Information Summit: Breaking The Barriers Let Water Information Flow! Waterweb Consortium and IRC International Water and Sanitation Centre September 9-12 Delft, The Netherlands 2003. Describes the organization, membership, aims and functions of the Southern African Water Information Network (SAWINET), a web-based source of information on integrated water resources management (IWRM) specifically designed to meet the needs of the Southern African water sector. Despite the low level of access to the Internet in Southern Africa, SAWINET is a valuable mechanism of accessing IWRM information and experience in Southern Africa. It is a one-stop centre that reduces the frustrations of searching for water information on the web.
Speaking of Sound
Authors: Porcello Thomas
Published: November 2004

This paper examines the role of speech-about-sound in sound-recording practice and the training of prospective sound engineers. The shift from apprenticeship to institutional learning in the mid-1980s is described as an effect of the digitization of the recording process, and provides a background to discussing how recording degree programs teach ‘professional audition’ to students via processes of instruction and internships. Two conversations recorded during a studio session are then analyzed to uncover the range of linguistic resources that novices and professionals use to talk about sound and to illustrate how talk about work is fundamental to the process of work. The paper concludes by suggesting that the institutional instructional model reconfigures the profession’s tacit knowledge by making explicit discussion of sound more ingrained in professional training.
Engineering the Performance
Authors: Horning Susan Schmidt
Published: November 2004

At the dawn of sound recording, recordists were mechanical engineers whose only training was on the job. As the recording industry grew more sophisticated, so did the technology used to make records, yet the need for recording engineers to use craft skill and tacit knowledge in their work did not diminish. This paper explores the resistance to formalized training of recording engineers and the persistence of tacit knowledge as an indispensable part of the recording engineer’s work. In particular, the concept of ‘microphoning’ - the ability to choose and use microphones to best effect in the recording situation - is discussed as an example of tacit knowledge in action. The recording studio also becomes the site of collaboration between technologists and artists, and this collaboration is at its best a symbiotic working relationship, requiring skills above and beyond either technical or artistic, which could account for one level of ‘performance’ required of the recording engineer. Described by one studio manager as ‘a technician and a diplomat’, the recording engineer performs a number of roles - technical, artistic, socially mediating - that render the concept of formal training problematic, yet necessary for the operation of technically complex equipment
Golden Ears and Meter Readers
Authors: Perlman Marc
Published: November 2004

Scientific claims to knowledge and the uses of technological artifacts are both inherently contestable, but both are not usually contested together. Consumers of ‘specialty’ audio equipment (known as the ‘high end’), however, connect both forms of resistance. These ‘audiophiles’ construct their own universe of meaning around their equipment; they cultivate a distinctive vocabulary and set of attitudes. In this they resemble other groups of users dedicated to supposedly antiquated technology. But they also engage in controversy to defend themselves against knowledge-claims that would delegitimize their universe of meaning. These debates concern recording formats or media (the relative merits of the compact disk [CD] and long-playing record [LP]), user ‘tweaks’ of purchased equipment, and the supposed audibility of differences between different brands of amplifiers, cables, or CD players. In all of these cases, audiophiles resist the claims of audio engineering by privileging their personal experiences, and they argue against scientific methodologies that seem to expose those experiences as illusory. Some of these patterns of epistemic contestation resemble those in non-musical domains (such as biomedicine). But audiophiles also make epistemic use of values crucial to their identity as music-lovers. They appeal to a common understanding of music as an exemplary locus of subjectivity, emotion, and self-surrender, in order to ward off the criticisms directed at them from a science they construe as objective, detached, and dispassionate
California Noise
Authors: Waksman Steve
Published: November 2004

Tinkering has long figured prominently in the history of the electric guitar. During the late 1970s and early 1980s, two guitarists based in the burgeoning Southern California hard rock scene adapted technological tinkering to their musical endeavors. Edward Van Halen, lead guitarist for Van Halen, became the most celebrated rock guitar virtuoso of the 1980s, but was just as noted amongst guitar aficionados for his tinkering with the electric guitar, designing his own instruments out of the remains of guitars that he had dismembered in his own workshop. Greg Ginn, guitarist for Black Flag, ran his own amateur radio supply shop before forming the band, and named his noted independent record label, SST, after the solid state transistors that he used in his own tinkering. This paper explores the ways in which music-based tinkering played a part in the construction of virtuosity around the figure of Van Halen, and the definition of artistic ‘independence’ for the more confrontational Black Flag. It further posits that tinkering in popular music cuts across musical genres, and joins music to broader cultural currents around technology, such as technological enthusiasm, the do-it-yourself (DIY) ethos, and the use of technology for the purposes of fortifying masculinity
Judicial Predictability and Federal Stability
Authors: Bednar Jenna
Published: November 2004

Institutions structure incentive environments for strategic actors. What is the effect of a flawed institution - one that is not perfectly predictable - on strategic behavior? This paper focuses on the influence of the judiciary on inter-governmental rivalry in a federation, in particular considering how shifts in judicial predictability affect federal opportunism. Results of the model indicate that governments in a federation challenge one another’s behavior in court less frequently as the judiciary grows more predictable but the effect of predictability on opportunism depends upon the cost of challenging an agent. When costs are low, increasing the predictability of the court increases opportunism, contrary to intuition. The model is extended to consider the effect of a biased court.
The Drumchapel Project
Authors: Mclelland Dorothy , Crawford John
Published: November 2004

The Drumchapel Project was a joint exploratory project between Glasgow Caledonian University, a 1992 university, and Drumchapel High School, a secondary school in a deprived area of Glasgow. The initial aim was to explore ICT skill levels among the school pupils but an information literacy agenda emerged in the course of the Project. Focus groups of pupils and questionnaires, administered to both students and staff, were used. The questionnaires were also administered to staff and students in a school in a more affluent area of Glasgow for comparative purposes (Hyndland Secondary School). Home computer ownership was found to be higher than expected and ICT skills levels were comparable to Hyndland pupils. Drumchapel High School was found to be where pupils learned most of their skills. The home and local learning centres were found to be much less important. The school library was found to be a greatly underutilized resource due to staffing restraints. The need for an integrated information literacy/ICT skills training strategy linking secondary and tertiary education was the main finding.
Young people’s use of non-fiction books at home
Authors: Shenton Andrew K.
Published: November 2004

Although many studies devoted to the information behaviour of young people have drawn attention to youngsters’ tendency to rely heavily on information sources within the home on account of their ready accessibility, work addressing in detail the exploitation of non-fiction books in these domestic settings is rare. This article draws on the findings of a wide-ranging qualitative research project conducted in the north-east of England with four to 18-year-olds to investigate, in particular, the nature of the volumes within home libraries that are consulted, the circumstances in which they are used, youngsters’ attitudes to the books they employ and the problems that they encounter when exploiting them. The article closes by assessing the implications of the findings, especially for the design of information materials and for libraries.
Investigating non-use of libraries in the UK using the mass-observation archive
Authors: Mcnicol Sarah
Published: November 2004

The Mass-Observation Archive at the University of Sussex sends regular ‘directives’ to its panel of volunteer correspondents around the UK asking them to reflect on various issues relating to the day-to-day lives of ordinary people. Two directives from the 1980s and 1990s relate to libraries, books and reading habits. These sets of written responses are valuable resources for library history and information science researchers because they include the opinions of non-users, which are notoriously difficult to obtain using conventional research methods. The use of such an approach may help to counter some of the criticisms of current library history practices as being outmoded and irrelevant. Not only is library history undervalued by historians, it is also frequently dismissed within the LIS field in general. Linking library history to issues of current concern, such as non-users, may create opportunities to demonstrate the relevance of library history more widely. This article reports on the findings of a study of the directive responses, focusing on non-use of libraries, and highlights the implications for librarians and library historians.
Hawks, Zealots and Hypocrites, but Not Free Riders: The Logics of Cooperation in Llano Del Beal
Authors: Linares Francisco
Published: November 2004

This article will study the mobilization of the residents of Llano del Beal (Cartagena, Spain), between 1987 and 1991, to defend their ‘quality of life,’ an objective that was in conflict with the interests of the region’s mining industry. The analysis, supported by qualitative data obtained from interviews and documents, rests on Olson’s paradigm of collective action (1971 [1965]). I argue that this paradigm has found itself subject to what could be described as a ‘dictatorship of the prisoner’s dilemma’, and attempt to show how a variety of ‘logics’ (‘zealots,’ ‘hypocrites,’ ‘hawks’) led the action in Llano del Beal, thus avoiding the many dilemmas of collective action. This article is the result of efforts to bring to light the way that these logics facilitated the emergence of social norms which, along with an exceptional leadership process, allowed the residents to achieve their goals. The conclusions of this empirical investigation serve to outline some reflections on the usefulness of its theoretical framework.
State Welfare Spending and Religiosity
Authors: Gill Anthony , Lundsgaarde Erik
Published: November 2004

What accounts for cross-national variation in religiosity as measured by church attendance and non-religious rates? Examining answers from both secularization theory and the religious economy perspective, we assert that cross-national variation in religious participation is a function of government welfare spending and provide a theory that links macro-sociological outcomes with individual rationality. Churches historically have provided social welfare. As governments gradually assume many of these welfare functions, individuals with elastic preferences for spiritual goods will reduce their level of participation since the desired welfare goods can be obtained from secular sources. Cross-national data on welfare spending and religious participation show a strong negative relationship between these two variables after controlling for other aspects of modernization.
Cooperation as a Transmitted Cultural Trait
Authors: Bisin Alberto , Topa Giorgio , Verdier Thierry
Published: November 2004

In this paper, we study an endogenous cultural selection mechanism for cooperative behavior in a setting where agents are randomly matched in a one-shot interaction Prisoner’s Dilemma, and may or may not have complete information about their opponent’s preferences. We focus on an endogenous socialization mechanism in which parents spend costly effort to transmit directly their trait to their offspring, taking into account the impact of (oblique) societal pressures on cultural transmission. For various ranges of parameter values, this mechanism generates a polymorphic population with a long-run presence of cooperative agents, even where replicator and indirect evolutionary mechanisms would bring about a monomorphic population with non-cooperation. Further, under some circumstances, the long-run fraction of cooperative agents is shown to be larger under incomplete than complete information.
The Impact of Universal Newborn Hearing Screening
Authors: Young Alys , Tattersall Helen , McCracken Wendy , Bamford John
Published: November 2004

This article presents results from qualitative interviews with 27 education services working as the lead agency with deaf children and families in sites where the universal newborn hearing screening programme (NHSP) is being piloted in England. This segment of data focuses specifically on how the social work role and practice is perceived by teachers of the deaf. It demonstrates the difficulties encountered in multi-agency working in the absence of specialist deaf child social workers: the perceived impact of deaf child referrals not satisfactorily fitting within any consistent organizational structure within social services; the poor liaison between education and social services over newly identified deaf children; the effects of parental information based on a limited understanding of the social work role and duties. The findings are set within current government initiatives to improve multi-agency working with disabled children and deaf children under three
Tapping the Perspectives of Children
Authors: Mishna Faye , Antle Beverley J. , Regehr Cheryl
Published: November 2004

The unique ethical issues related to conducting research with children are insufficiently distinguished from issues in working with vulnerable groups, despite a shift to recognizing children as active in the research process. Qualitative researchers are challenged to consider complex ethical issues related to children and are obligated to protect their rights, freedoms, safety, and dignity. While some issues are similar to those in any research context, the nature of the researcher-participant relationship, and the unstructured nature of qualitative research methods, add a dimension of risk. This article examines ethical issues in qualitative research with children: (1) consent and assent; (2) the obligation to protect children from harm while respecting
Recruiting Diverse Groups of Young People to Research
Authors: Munford Robyn , Sanders Jackie
Published: November 2004

Ethical matters in research with children and young people, such as recruitment procedures and gaining informed consent, have been a fruitful ground for exploring issues such as power and protection, researcher responsibility and social versus individual good, that feature in all human research. It has also raised for debate the extent to which children and young people are similar to, or different from, adults and whether they require special protection to manage their involvement. A four-step process for recruiting young people into a qualitative research project is outlined. Young people were recruited as fully consenting participants and, at the same time, adult requirements that parents be informed and agree to their children’s involvement was achieved. The process discussed enables the exercise of parental responsibility while not discounting the rights and needs of children for recognition of their agency and autonomy
Tensile properties of gas tungsten arc weldments in commercially pure titanium, Ti–6Al–4V and Ti–15V–3Al–3Sn–3Cr alloys at different strain rates
Authors: Wang S.H. , Wei M.D.
Published: November 2004

The influence of microstructure and strain rate on the mechanical behaviour of three titanium alloys having applications in aerospace, namely, commercially pure titanium (α phase), Ti–6Al–4V (α + β phases) and Ti– 15V–3Cr–3Sn–3Al (β phase) is investigated for both the parent metals and their gas tungsten arc weldments. The results indicate that the tensile strengths of the three as received titanium alloys and their weldments increase with increasing strain rate. However, their elongations decrease with increasing strain rate. The as received Ti–6Al–4V alloy and its weldment, with a mixed α and β phase microstructure, have the maximum strength and microhardness. Commercial purity titanium metal and its weldment exhibit the minimum strength and microhardness. The tough Ti–15V–3Cr–3Sn–3Al alloy and its weldment, having a fully β phase microstructure, appear to have optimum strength and microhardness. The tensile properties of all three titanium alloy weldments are inferior to those of the as received metals.
Integrated fracture mechanics approach to analyse fatigue behaviour of welded joints
Authors: Chapetti M.D. , Belmonte J. , Tagawa T. , Miyata T.
Published: November 2004

Current fracture mechanics methods for fatigue assessment, including those that consider thresholds for crack propagation, are based on long crack behaviour. The present work is concerned with an attempt to predict the fatigue strength of welded joints using a fracture mechanics approach that takes into account the fatigue behaviour of short cracks. The methodology estimates the fatigue crack propagation rate as a function of the difference between the applied driving force and the material threshold for crack propagation, which is a function of crack length. The fatigue strength of butt welded specimens stressed transversely was analysed. Experimental results from the literature were used for comparison. Estimations are obtained by using only the fatigue limit and the fatigue propagation threshold for long cracks, and the applied stress distribution along the crack path obtained from simple finite element models. The influence of plate thickness, initial crack length, and reinforcement angle on fatigue strength of butt welded joints was analysed. Results show good agreement with experimental trends.
New structure of automatic torch and new approach for controlling drop transfer in rotating spray welding arc
Authors: Luo J. , Lin Y. , Luo Q. , Wu Y.
Published: November 2004

Using computer aided design/computer aided manufacturing technology, an automatic welding system is designed and manufactured for high current, high speed, and high deposition metal arc active gas (MAG) welding. The welding torch structure is evaluated and optimised via the finite element method and practical welding technology experiments. Finally, the process of high deposition MAG welding is investigated, and it is highlighted that on application of a longitudinal magnetic field to the high deposition MAG welding process, a steady metal transfer and drop deposition condition can be achieved, which is suited to the demands of high current, high speed welding technology.
Planning of randomized early detection trials
Authors: Hu Ping , Zelen Marvin
Published: November 2004

Consider a randomized clinical trial to evaluate the benefit of screening an asymptomatic population. Suppose that the subjects are randomized into a usual care and a study group. The study group receives one or more periodic early detection examinations aimed at diagnosing disease early, when there are no signs or symptoms. Early detection clinical trials differ from therapeutic trials in that power is affected by: i) the number of exams, ii) the time between exams and iii) the ages at which exams will be given. These design options do not exist in therapeutic trials. Furthermore; long-term follow-up may result in a reduction of power. In general, power increases with number of examinations, and the optimal follow-up time is dependent on the spacing between examinations. Clinical trials in which the usual care group receives benefit are also discussed. Two designs are discussed, for example the ‘up-front design’ in which all subjects receive an initial exam and then are randomized to the usual care and study groups and the ‘close-out design’ in which the usual care group receives an exam which is timed to be given at the same time as the last exam in the study group. Both families of designs significantly reduce the power. Power calculations are made for two clinical trials, which actually used these two designs.
Diversity of model approaches for breast cancer screening: a review of model assumptions by The Cancer Intervention and Surveillance Network (CISNET) Breast Cancer Groups
Authors: Boer Rob , Plevritis Sylvia , Clarke Lauren
Published: November 2004

The National Cancer Institute-sponsored Cancer Intervention and Surveillance Network program on breast cancer is composed of seven research groups working largely independently to model the impact of screening and adjuvant therapy on breast cancer mortality trends in the US from 1975 to 2000. Each of the groups has chosen a different modeling methodology without purposeful attempt to be in contrast with each other. The seven groups have met biannually since November 2000 to discuss their methodology and results. This article investigates the differences in methodology. To facilitate this comparison, each of the groups submitted a description of their model into a uniformly structured web based ‘model profiler’. Six of the seven models simulate a preclinical natural history that cannot be observed directly with parameters estimated from published evidence concerning screening and therapy effects. The remaining model regards published evidence on intervention effects as prior information and updates that with information from the US population in a Bayesian type analysis. In general, the differences between the models appear to be small, particularly among the models driven by natural history assumptions. However, we demonstrate that such apparently small differences can have a large impact on surveillance of population trends. We describe a systematic approach to evaluating differences in model assumptions and results, as well as differences in modeling culture underlying the differences in model structure and parameters.
Computerized Physician Order Entry and Online Decision Support
Authors: Handler Jonathan A. , Feied Craig F. , Coonan Kevin , Vozenilek John , Gillam Michael , Peacock Peter R. , Sinert Rich , Smith Mark S.
Published: November 2004

Computerized physician order entry (CPOE) and decision support systems (DSS) can reduce certain types of error but often slow clinicians and may increase other types of error. The net effect of these systems on an emergency department (ED) is unknown. The consensus participants combined published evidence with expert opinion to outline recommendations for success. These include seamless integration of CPOE and DSS into systems and workflow; ensuring access to Internet‐based and other online support material in the clinical arena; designing systems specifically for the ED and measuring their impact to ensure an overall benefit; ensuring that CPOE systems provide error and interaction checking and facilitate weight‐ and physiology‐based dosing; using interruptive alerts only for the highest‐severity events; providing a simple, vendor‐independent interface for institutional customization of CPOE alert thresholds; maximizing the use of automated systems and passive data capture; and ensuring the widespread availability of CPOE and DSS using secure wireless and portable technologies where appropriate. Decisions regarding CPOE and DSS in the ED should be guided by the ED chair or designee. Much of what is believed to be true regarding CPOE and DSS has not been adequately studied. Additional CPOE and DSS research is needed quickly, and this research should receive funding priority. DSS and CPOE hold great promise to improve patient care, but not all systems are equal. Evidence must guide these efforts, and the measured outcomes must consider the many factors of quality care.
Supporting Clinical Practice at the Bedside Using Wireless Technology
Authors: Bullard Michael J. , Meurer David P. , Colman Ian , Holroyd Brian R. , Rowe Brian H.
Published: November 2004

Objectives: Despite studies that show improvements in both standards of care and outcomes with the judicious application of clinical practice guidelines (CPGs), their clinical utilization remains low. This randomized controlled trial examined the use of a wirelessly networked mobile computer (MC) by physicians at the bedside with access to an emergency department information system, decision support tools (DSTs), and other software options. Methods: Each of ten volunteer emergency physicians was randomized using a matched‐pair design to work five shifts in standard fashion (desktop computer [DC] access) and five shifts with a wirelessly networked MC. Work pattern issues and electronic CPG/DST use were compared using end‐of‐shift satisfaction questionnaires and review of a CPG/DST database. Repeated‐measures analysis of variance was used to examine between‐shift differences. Results: A total of 100 eight‐hour shifts were evaluated; 99% compliance with postshift questionnaires was achieved. Using a seven‐point Likert scale (MC values first), MCs were rated as being as fast (5.04 vs. 4.54; p = 0.13) and convenient (5.08 vs. 4.14; p = 0.07) as DCs. Overall, physicians rated MCs to be less efficient (3.18 vs. 4.30; p = 0.02) but encouraged more frequent use of DSTs (4.10 vs. 3.47; p = 0.03) without impacting doctor–patient communication (2.78 vs. 2.96; p = 0.51). During the study period, physician use of an intranet Web application (eCPG) was more frequent during shifts assigned to the MC when compared with the DC (eCPG uses/shift, 3.6 vs. 2.0; p = 0.033). Conclusions: The MC technology permitted physicians to access information at the bedside and increased the use of CPG/DST tools. According to physicians, patients appeared to accept their use of information technology to assist in decision making. Development of improved computer technology may address the major limitation of MC portability.
Virtual TeleStroke Support for the Emergency Department Evaluation of Acute Stroke
Authors: Schwamm Lee H. , Rosenthal Eric S. , Hirshberg Alan , Schaefer Pamela W. , Little Elizabeth A. , Kvedar Joseph C. , Petkovska Iva , Koroshetz Walter J. , Levine Steven R.
Published: November 2004

Objectives: Telemedicine‐enabled acute stroke consultation (TeleStroke) may be useful to determine eligibility for treatment with tissue plasminogen activator (tPA) and provide support to emergency departments without on‐site stroke expertise. Methods: Emergency physicians consulted with stroke neurologists via two‐way videoconferencing in the evaluation of patients with possible acute stroke. History, neurologic examination, and computed tomography of the head were reviewed to determine eligibility for treatment with tPA. Interpretations of computed tomography were compared for inter‐rater reliability between the neurologist and the neuroradiologist using a conventional workstation. Videotape and written records were analyzed to determine time intervals, patient management, and user satisfaction. Results: The authors reviewed data from 24 patients evaluated over 27 months at an island‐based hospital. The mean National Institutes of Health Stroke Scale score was 5.7 (range, 0–22). Fifteen patients arrived at the emergency department less than three hours after symptom onset; 12 were presented for TeleStroke consultation within three hours after symptom onset. Eight of these 12 (75%) had acute ischemic stroke, and six of these eight potentially eligible patients (75%) received intravenous tPA. There was very good agreement among all remote readers for detecting the one case of imaging exclusion (subdural hemorrhage). There were no protocol violations, and a mean (± SD) consult‐to‐needle time of 36 (± 15) minutes and door‐to‐needle time of 106 (± 22) minutes was achieved. Transfer was avoided in 11 patients. Physicians believed that TeleStroke consultation improved care in >95% of the cases. Conclusions: TeleStroke videoconferencing can support emergency department–based evaluation of acute stroke and may facilitate tPA delivery in neurologically underserved facilities. A prospective, randomized trial is needed to determine if these systems are superior to traditional telephone consultation.
Automating Research Data Collection
Authors: Shapiro Jason S. , Bessette Michael J. , Baumlin Kevin M. , Ragin Deborah Fish , Richardson Lynne D.
Published: November 2004

This article reviews the capabilities, advantages, and disadvantages of three forms of automated data collection—scannable data forms, Web‐based forms, and handheld computers—compared with the current standard of data entry by hand on paper forms. Each of these methods is reviewed with respect to ease of use, experience required of designer, end‐user training requirements, costs, flexibility, speed, accuracy/error rate, potential for data loss, need for technical support, and equipment and/or software requirements. A discussion of their appropriate application to various kinds of studies is included, followed by examples of research studies using each of these methods.
Independent roles of thedachshundandeyes absentgenes in BMP signaling, axon pathfinding and neuronal specification
Authors: Miguel-Aliaga Irene , Allan Douglas W. , Thor Stefan
Published: November 2004

In the Drosophila nerve cord, a subset of neurons expresses the neuropeptide FMRFamide related (Fmrf). Fmrf expression is controlled by a combinatorial code of intrinsic factors and an extrinsic BMP signal. However, this previously identified code does not fully explain the regulation of Fmrf. We have found that the Dachshund (Dac) and Eyes Absent (Eya)transcription co-factors participate in this combinatorial code. Previous studies have revealed an intimate link between Dac and Eya during eye development. Here, by analyzing their function in neurons with multiple phenotypic markers, we demonstrate that they play independent roles in neuronal specification, even within single cells. dac is required for high-level Fmrf expression, and acts potently together with apterous and BMP signaling to trigger Fmrf expression ectopically, even in motoneurons. By contrast, eya regulates Fmrf expression by controlling both axon pathfinding and BMP signaling, but cannot trigger Fmrf ectopically. Thus, we show that dac and eya perform entirely different functions in a single cell type to ultimately regulate a single phenotypic outcome.
Stabilization of β-catenin in the mouse zygote leads to premature epithelial-mesenchymal transition in the epiblast
Authors: Kemler Rolf , Hierholzer Andreas , Kanzler Benoît , Kuppig Stefan , Hansen Kati , Taketo Makoto M. , de Vries Wilhelmine N. , Knowles Barbara B. , Solter Davor
Published: November 2004

Many components of the Wnt/β-catenin signaling pathway are expressed during mouse pre-implantation embryo development, suggesting that this pathway may control cell proliferation and differentiation at this time. We find no evidence for a functional activity of this pathway in cleavage-stage embryos using the Wnt-reporter line, BAT-gal. To further probe the activity of this pathway, we activated β-catenin signaling by mating a zona pellucida3-cre(Zp3-cre) transgenic mouse line with a mouse line containing an exon3-floxedβ-catenin allele. The result is expression of a stabilized form ofβ-catenin, resistant to degradation by the GSK3β-mediated proteasome pathway, expressed in the developing oocyte and in each cell of the resulting embryos. Nuclear localization and signaling function of β-catenin were not observed in cleavage-stage embryos derived from these oocytes. These results indicate that in pre-implantation embryos, molecular mechanisms independent of the GSK3β-mediated ubiquitination and proteasome degradation pathway inhibit the nuclear function of β-catenin. Although the mutant blastocysts initially developed normally, they then exhibited a specific phenotype in the embryonic ectoderm layer of early post-implantation embryos. We show a nuclear function of β-catenin in the mutant epiblast that leads to activation of Wnt/β-catenin target genes. As a consequence,cells of the embryonic ectoderm change their fate, resulting in a premature epithelial-mesenchymal transition.