bluuebunny/crossref_metadata_2025 huggingface dataset:
“I wyll be thy true servaunte / And trewely serve thee”: Guildhall Minstrelsy in the Gest of Robyn Hode
Authors: Ho Dean A.
Published: May 2005

Although the Gest of Robyn Hode is familiar as the earliest-known verse life of the medieval English outlaw, virtually no scholars have offered detailed conjecture about the manner of its earliest performance. Offering an analysis of the potential of the aged text as performed
A Virtual Reality—Based Exercise System for Hand Rehabilitation Post-Stroke
Authors: Adamovich Sergei V. , Merians Alma S. , Boian Rares , Lewis Jeffrey A. , Tremaine Marilyn , Burdea Grigore S. , Recce Michael , Poizner Howard
Published: May 2005

This paper presents preliminary results from a virtual reality (VR)-based system for hand rehabilitation that uses a CyberGlove and a Rutgers Master II-ND haptic glove. This computerized system trains finger range of motion, finger flexion speed, independence of finger motion, and finger strength using specific VR simulation exercises. A remote Web-based monitoring station was developed to allow telerehabilitation interventions. The remote therapist observes simplified versions of the patient exercises that are updated in real time. Patient data is stored transparently in an Oracle database, which is also Web accessible through a portal GUI. Thus the remote therapist or attending physician can graph exercise outcomes and thus evaluate patient outcomes at a distance. Data from the VR simulations is complemented by clinical measurements of hand function and strength. Eight chronic post-stroke subjects participated in a pilot study of the above system. In keeping with variability in both their lesion size and site and in their initial upper extremity function, each subject showed improvement on a unique combination of movement parameters in VR training. Importantly, these improvements transferred to gains on clinical tests, as well as to significant reductions in task-completion times for the prehension of real objects. These results are indicative of the potential feasibility of this exercise system for rehabilitation in patients with hand dysfunction resulting from neurological impairment.
Comparison of Two VR Platforms for Rehabilitation: Video Capture versus HMD
Authors: Rand Debbie , Kizony Rachel , Feintuch Uri , Katz Noomi , Josman Naomi , Rizzo Albert “Skip” , Weiss Patrice L. (Tamar)
Published: May 2005

In recent years, clinical studies have begun to demonstrate the effectiveness of VR as an intervention tool for a variety of neurological conditions. There remain, however, a number of important issues that must be addressed in order to determine how widely VR-based intervention should be applied, and the user and platform characteristics that may be important when using VR in clinical settings. One of the unresolved issues that must be addressed is the suitability of particular VR platforms in relation to the therapeutic goals one wishes to achieve. Studying and identifying the characteristics of each platform may assist the therapist in choosing a suitable VR platform for the patient's needs. The purpose of this paper is to describe the results of a study of healthy participants (N = 89) using 2 different VR platforms in combination with 1 of the 2 virtual environments that was designed to compare the sense of presence, incidence of side effects, perceived exertion, and performance. The data demonstrate significant differences in some of the key characteristics of both VR platforms and environments as they affect participants' sense of presence, performance, side effects, and exertion. We conclude that when seeking a suitable VR therapeutic application, the user's characteristics together with attributes of the VR platform must be taken into consideration since both appear to have an impact on key outcome measures.
A Neuroimaging Pilot Study of Task Loading and Executive Function Using a Virtual Apartment
Authors: Baumann Stephen
Published: May 2005

Frontal-lobe injuries often adversely affect cognitive functions such as planning and decision making. These are known as executive functions, and they reside largely in the frontal lobes of the brain. In preparation for studies of patients with cognitive deficits, including a large study of Vietnam veterans with frontal-lobe injuries, 3 normal subjects participated in a functional magnetic resonance imaging (fMRI) pilot study of cognitive function while using an interactive virtual apartment constructed with computer-game development software. At least 1 day prior to the fMRI scan, subjects were given a passive tour of multiple environments within a virtual world and then allowed to practice navigating through the world using a joystick and touch pad. Within a week they returned for the fMRI study, in which they were given 2 minutes on each of 5–7 contiguous runs to perform tasks within the virtual apartment that were designed to be increasingly difficult (i.e., task loading). For example, in one of the least difficult runs, they were asked to navigate through a small apartment of 5 rooms and to turn on all of the light switches. In the last and potentially most difficult run, they were asked to find and open all of the closets (4) in the apartment and mentally categorize and count the number of items within the closets. After the data were detrended and filtered, the effects of task performance on brain-activation patterns were computed. There was a statistically significant correlation between subjective rating of task difficulty and pixel intensity in the anterior frontal lobes compatible with highly significant bilateral activation when the more difficult tasks were compared to the less difficult tasks. This study illustrates how virtual environments can be used for more naturalistic studies of executive function, and it provides normative data for later comparison with head-injured patients.
Manipulation Practice for Upper-Limb Amputees Using Virtual Reality
Authors: Kuttuva Manjuladevi , Burdea Grigore , Flint James , Craelius William
Published: May 2005

We developed a novel interface that gives upper-limb amputees a virtual hand that can manipulate objects in a challenging environment. The interface registers specific myokinetic activity of the residual limbs, and encodes the intended voluntary movements that are then actualized as virtual hand motions. The composite myokinetic interface-virtual reality (MKI-VR) system consists of an array of pressure sensors mounted in an arm sleeve, sensors of elbow- and shoulder-joint angles, a trained filter derived from the pseudoinverse of a response matrix, and a virtual hand model, programmed in Java 3D. Users can manipulate virtual objects such as balls and pegs in a 3D training environment, while their performance at various difficulty levels is scored. In preliminary tests, upper-limb amputees readily gained the ability to grasp and release virtual objects. We propose the utility of the MKI-VR system both as an assessment tool for rehabilitation engineers, and as a motivator for amputees to exercise and thereby maintain their residual motor ability.
Virtual-Environment-Based Telerehabilitation in Patients with Stroke
Authors: Holden Maureen K. , Dyar Thomas A. , Schwamm Lee , Bizzi Emilio
Published: May 2005

We describe a telerehabilitation system that has been developed in our laboratory, and initial results following use of the system on 2 patients with stroke. The system allows a therapist in a remote location to conduct treatment sessions, using a virtual-environment-based motor-training system, with a patient who is located at home. The system consists of a patient computer with motion-capture equipment and video camera, a therapist computer with video camera, and virtual-environment software that is synchronized over a high-speed Internet connection. The patient's movements are animated within the context of a virtual scene as she attempts to imitate a prerecorded movement, while the therapist can direct and monitor the activity in real time, as displayed in the animated virtual scene and via videoconference. The design, technical testing, and clinical feasibility testing of the system are reported. Results from the first 2 stroke patients to use the system indicate that patients made significant gains in upper-extremity function as measured by standard clinical tests and by their subjective report. As well, both patients demonstrated gains on quantitative kinematic measures of upper-extremity trajectories performed in the real world, indicating transfer of training from VE to real-world performance.
Building Exposure: Synergy of Interaction and Narration Through the Social Channel
Authors: Herbelin Bruno , Ponder Michal , Thalmann Daniel
Published: May 2005

The ability to build and control exposure through a seamless synergy of interaction and narration is a strongly required feature of a new type of immersive-VR training and therapy system. This paper presents a practical approach for immersive-VR training and therapy applications based on interactive storytelling. It provides detailed description of a working implementation of the Interactive Narration Space (INS); this approach combines and satisfies both interaction and narration requirements through the use of high-level social interaction. By introducing the Social Channel, we aim at minimizing the contradictions between control over the story required by the trainer/therapist and interaction required by the trainee/patient. These concepts and their practical realization have been investigated in the context of emergency-situation training and psychotherapeutic exposure, and could validate the usability of mediated interaction with a virtual assistant.
Zoos and Eyes: Contesting Captivity and Seeking Successor Practices
Authors: Acampora Ralph
Published: May 2005

This paper compares the phenomenological structure of zoological exhibition to the pattern prevalent in pornography. It examines several disanalogies between the two, finds them lacking or irrelevant, and concludes that the proposed analogy is strong enough to serve as a critical lens through which to view the institution of zoos. The central idea uncovered in this process of interpretation is paradoxical: Zoos are pornographic in that they make the nature of their subjects disappear precisely by overexposing them. The paper asserts that the keep are thus degraded or marginalized through the marketing and consumption of their very visibility and criticizes the pretense of preservation. Furthermore, the paper subjects the related framework of captivity to Foucauldian analysis and critique—we see that the "zoöpticon" deserves designation as an island of power in the carceral archipelago of hegemonic social institutions mapped by Foucault. Hence, this paper suggests that the zoo as we know it be phased out in favor of richer and less oppressive modes of encountering other forms of life; toward this end, the paper explores and assesses alternative approaches to, and practices of, nonhuman animal spectatorship and cross-species conviviality.
Designer Cows: The Practice of Cattle Breeding Between Skill and Standardization
Authors: Grasseni Cristina
Published: May 2005

Cattle fair arenas are panopticon-like spaces that are instrumental in dissecting the cow's body into functional parts or traits. The arena aestheticizes a partitioning gaze that is codified in a marking system: the "linear evaluation protocol" for milk cows. The positioning of the nonhuman animal body into a highly artificial context allows one to view the cow as a self-standing object, ready to be partitioned. The exhibition space of the cattle fair and the surveying eye of the cattle fair judge aim to recreate a laboratory space within the relatively "artisanal" and approximate context of the breeding practice. However, there are several limitations, down sides, and contingencies that contrast the project of standardization of the skilled practice of breeding.
Trophy Shots: Early North American Photographs of Nonhuman Animals and the Display of Masculine Prowess
Authors: Brower Matthew
Published: May 2005

This essay examines the relationship between the display of non-human animal trophies and masculinity through an analysis of progressive-era American wildlife photography. In the 1890s, North American animal photographers began circulating their images in sporting journals and describing their practice as a form of hunting. These camera hunters exhibited their photographs as proof of sportsmanship, virility, and hunting prowess.
Falling in Love with Horses: The International Thoroughbred Auction
Authors: Cassidy Rebecca
Published: May 2005

Based on fieldwork in Newmarket, England, and Kentucky, this paper examines the acts of looking that take place at international thoroughbred horse auctions. Racehorse caretakers (owners) employ bloodstock agents to select the yearling thoroughbred who will make the best racehorse as a 2-year-old and, hopefully, successful stallion or broodmare after retiring from the track as a 4- or 5-year old. The paper assesses the criteria used to assess yearlings: pedigree, conformation, and "that something extra."The paper concludes that the ambiguous status of the bloodstock agent derives from the liminal task the agent performs, communicating with a young, nonhuman animal to discover the animal's essential properties. Selecting yearlings depends upon a process of divination that mitigates against the characterization of western thought as "rational" and opposed to decision-making processes conventionally thought of as "non-normal" or irrational.
Decentralizing Government and Decentering Gender: Lessons from Local Government Reform in South Africa
Authors: Beall Jo
Published: May 2005

Localization and decentralization are frequently presented as good for women. However, the reality is not so clear cut. Local government is the tier that is closest to people, but relationships, structures, and processes of local governance can limit both the space for women’s participation and the policy potential for addressing gender issues. The experience of democratic reform in South Africa is invariably held up as an example of good practice in advancing gender equity in governance. Critically drawing on this experience, the article points out some of the paradoxes for women and gender equity that arise from decentralization strategies and governance at the local level.
Problems and Prospects for Democratic Settlements: South Africa as a Model for the Middle East and Northern Ireland?
Authors: Jung Courtney , Lust-Okar Ellen , Shapiro Ian
Published: May 2005

Intense ethnic, racial, and religious violence led many to classify South Africa, Northern Ireland, and Israel/Palestine as intractable conflicts. Yet they diverged, with only South Africa achieving a lasting settlement. The authors explain why. The authors analyze them as a distinctive type of negotiated transition. The ancién regime is an imperfect democracy, subject to electoral constraints and legitimated by democratic principles that it violates. This constrains negotiations but helps manage difficult commitment problems. The authors show how the principals navigated constraints and took advantage of opportunities in South Africa but have failed—so far—to do so in the other two conflicts.
Cultural Values and Communication Online
Authors: Warden Clyde A. , Chen Judy F. , Caskey D’Arcy
Published: May 2005

Whereas many researchers have examined differences in values and behavior between Westerners and Asians, fewer have investigated differences within Asian cultural groups. A recent government initiative in Taiwan to encourage international education has led to the development of an international MBA program at the National Cheng Kung University in Tainan; both Chinese and Southeast Asian students participate in the program. They exhibit different behaviors in their classes, particularly in their postings in online discussion boards. For reasons that can be partly explained by the students’ responses on a Chinese-Value Survey, Chinese students tend to post fewer messages than Southeast Asians, and both groups post fewer messages than Westerners in the classes under study. Instructors in multicultural classes have to consider such differences when they design assignments and set expectations for students in online discussions.
The MBA in Singapore
Authors: Rogers Priscilla S. , Wong Irene F.H.
Published: May 2005

This study assesses communication training provided in MBA and executive MBA programs in Singapore. The authors found that Singapore is a microcosm in terms of (a) requirements for English competency, (b) the variety of communication offerings, and (c) the lack of uniformity in the delivery of communication training. Whereas Singaporean MBA/EMBA programs sit in a highly internationalized environment with substantial foreign student intake, and whereas Singapore is known for adopting best practices in education from around the world, communication training for management evidences a veneer of Asian content and imitation rather than innovation. These findings caused the authors to rethink what they have traditionally regarded as management communication and to consider the need for further internationalization, not only in this multicultural city-state but worldwide.
Effect of heat treatment and interlayer on weld strength and microstructure of solid state joints between Cu and Al powder metallurgical preform tubes
Authors: Krishna B. Vamsi , Venugopal P. , Rao K. Prasad
Published: May 2005

Solid state joints made between Cu and Al powder metallurgical preforms by cold extrusion were heat treated at various temperatures and for various times with and without an interlayer (Ni) to evaluate the interfacial microstructure and weld strength. The heat treatment conditions were optimised for highest weld strength without deleterious effects in terms of intermetallic compounds, Kirkendall voids, etc. Heat treatment of these joints made without an interlayer resulted in a 40% increase in the strength. However, under some processing conditions different intermetallic compounds and phases were formed during heat treatment without an interlayer. Application of an interlayer in the form of powder allowed partial interdiffusion of metal at the interface and this minor interdiffusion had no influence on the weld strength and microstructure. Finer interlayer particle size increased the weld strength by eliminating physical discontinuities and residual particles at the interface. The heat treatment of Cu–Al joints made using 1 μm Ni powder as the interlayer increased the strength by 82% in comparison with that in the as extruded condition.
Friction Skew-stir welding of lap joints in 5083–0 aluminium
Authors: Cantin G. M. D. , David S. A. , Thomas W. M. , Lara-Curzio E. , Babu S. S.
Published: May 2005

A variant of the friction stir welding technique developed at TWI, called Skew-stir (tradename) was applied to the welding of lap joints in Al alloy AA5083–0. This technique differs from the conventional method in that the axis of the tool is given a slight inclination, or skew, to that of the machine spindle. It is particularly advantageous in instances where a wide weld region is required, such as lap joints in which the interface is perpendicular to the machine axis. The microstructures and mechanical properties of welds made using both a conventional pin type probe and the rotary Skew-stir technique with an A-Skew (tradename) probe were studied. The joints made using the Skew-stir technique sustained significantly higher tensile loads and had longer fatigue lives compared with those made using the conventional pin type probe.
Effect of power source characteristic on CO2 short circuiting arc welding
Authors: Yamane S. , Xiang S. , Kaneko Y. , Oshima K.
Published: May 2005

Some problems are reported concerning the observation of the weld pool and effects of the power source characteristic on arc stability in CO2 short circuiting arc welding. First, the effect of a power source with a constant voltage characteristic on CO2 short circuiting arc welding is investigated by analysing the behaviour of the voltage and the current. From the results of this analysis, the cause of spatter generation is identified. A new power source characteristic is then proposed to improve the stability and the self-regulation of the arc. By adjusting the power source characteristic, the metal transfer can be stabilised in the CO2 short circuiting arc welding process, i.e. the present authors have developed a power source having a non-linear characteristic. Its performance is verified by carrying out experiments.
Friction welding of pure titanium and pure nickel
Authors: Fuji A. , Horiuchi Y. , Yamamoto K.
Published: May 2005

The joint tensile strength and metallurgical properties of a friction welded joint of commercially pure Ti and pure Ni has been investigated in as welded and post-weld heat treated conditions. While friction pressure did not significantly impinge on joint tensile strength, joint tensile strength was affected by friction time. A 1–1·5 μm thick interlayer is essential to join pure Ti and pure Ni using friction welding. A maximum joint tensile strength of 450 MPa was achieved and the joint fractured in the Ti original (not heat affected zone) substrate, i.e. the joint efficiency was approximately 112% relative to Ti substrate and 94·5% relative to Ni substrate. The joint tensile strength abruptly decreased as heating temperature was increased to 873 K and/or the Larson-Miller parameter was increased to approximately 19–20 × 103. The joint tensile strength rapidly decreased with increasing interlayer thickness up to approximately 10 μm, and then remained constant for further increase in interlayer thickness. Four layers occurred at the interface of joints heated to more than 873 K, namely Ti2Ni, TiNi, TiNi2, TiNi3. The fracture of heated joints propagated mainly in the Ti2Ni layer and/or at the interface between the TiNi and TiNi3 layers.
Long fatigue crack growth behaviour of ferritic steel weld metal
Authors: Venkateswaran P. , Raman S. Ganesh Sundara , Pathak S. D.
Published: May 2005

Single edge notched weld joint specimens were tested at different stress levels to study the long fatigue crack growth behaviour of a ferritic steel (nuclear grade SA333 Grade 6 steel) weld metal at two stress ratios R of 0·1 and – 1. A two slope behaviour was noticed in the crack growth rate versus stress intensity factor range plots at both stress ratios. Different parameters were employed to generalise the load ratio effect on fatigue crack growth rate.
Laser welding of copper–nickel alloys: A numerical and experimental analysis
Authors: Ferro P. , Bonollo F. , Tiziani A.
Published: May 2005

Melt run trials were carried out on Cu–Ni bars using a CO2 laser source in order to analyse the effects of welding parameters (i.e. laser power, welding speed) on geometrical characteristics and on the microstructure of the bead. Experimental results were then used to determine the source parameters to be employed in a finite element model (FEM) of the welding process, with particular attention paid to the thermal field induced by the laser beam. A specific procedure, named ‘automatic remeshing technique’, was used in order to minimise the computation time. The aim was to create a reliable numerical model, suitable for the optimisation, in practical cases, of welding processes of these kinds of materials. A good correlation, in terms of predicted cooling rates, with the values calculated from SDAS measurements, was observed.
Influence of GMAW-P current waveforms on heat input and weld bead shape
Authors: Joseph A. , Farson D. , Harwig D. , Richardson R.
Published: May 2005

Manufacturers use different, proprietary pulse current programming algorithms in their synergic ‘one knob control’ pulsed gas metal arc welding (GMAW-P) power supplies. Since the different pulse waveforms produced by these supplies can produce somewhat different welding characteristics, inconsistent results can be obtained when transferring welding procedures between different GMAW-P power supplies. A primary objective of this work was to characterise the differences in welding heat input and weld bead shape that could be produced by the pulsed current waveforms from four different commercial supplies. To eliminate the affects of subtle differences in electrical characteristics and to ensure that the exact shape of all waveforms was fully known, the comparison was also done by simulating the waveforms generated by three of the four power supplies on the fourth supply, which was equipped with waveform programming capability. Then, the four waveforms were used to create ‘bead on plate’ welds over a range of wire feed speed settings, and corresponding heat inputs were calculated from current and voltage samples recorded by a computer data acquisition system during welding. Welds were also done at the same wire feed speed setting using a constant voltage supply. All welds were then cross-sectioned for penetration and dilution measurements. In general, all of the waveforms produced good metal transfer and weld quality. However, the heat input and beads shapes varied noticeably. The heat inputs for the four pulse waveforms and constant voltage welds differed by as much as 150 J mm−1 (17% of the maximum heat input) at the highest wire feed speed of 212 mm s−1. The weld penetration differed by 1 mm (22% of the maximum penetration) at a wire feed speed of 169 mm s−1 and the dilution differed a maximum value of 6.5% dilution (22% of the maximum dilution) at a wire feed speed of 169 mm s−1.
Study of single side single pass submerged arc welding using reusable backing strip
Authors: Mandal N. R. , Maiti Rajiv
Published: May 2005

An attempt has been made to establish a submerged arc welding procedure that will enable the production of welded butt joints in thin steel plate, having proper fusion and reinforcement geometry in a single welding run. In this work, the combined effect of the basic welding parameters, i.e. voltage, current, and speed, along with the effect of thickness, on weld penetration have been studied. Also an attempt has been made to develop a flux filled reusable backing strip. In the present investigation submerged arc welding flux in its powdered form has been used without application of any external pressure and also without any additives. Experiments have been carried out extensively on 6 mm and 8 mm thick C–Mn steel plate specimens. This form of backing strip has shown great promise towards achieving single side single run welding. The welds achieved in this single side single pass welding process are not yet 100% satisfactory, however, the results indicate the feasibility of the process to achieve quality welds to meet relevant quality standards.
Probing the role of instantaneous current waveform in numerical modelling of resistance spot welding process
Authors: De A. , Dorn L. , Momeni K.
Published: May 2005

In numerical modelling of the resistance spot welding process, a significant input parameter is the value of the weld current and traditionally, the rms value corresponding to the actual, instantaneous current waveform is used. The rms value implies a constant weld current for the entire weld time instead of the real-time current waveforms. Although the rms value represents an effective approximation of the real-time current waveform, the influence of the peak current and of the current slopes in each half cycle on the welding process cannot be realised in modelling when the rms value is used. Mathematically, an alternating current waveform with higher peak value and lower current on-time in each half cycle may correspond to a rms value that is nearly similar corresponding to another waveform with lower peak value and larger current on-time in each half cycle. The resulting rate of heating and the subsequent size of the weld nugget may not be the same for both the current signals since the resistive heating in resistance spot welding is transient in nature. This is precisely observed in the present work through a detailed investigation using three different ac spot welding machines. A two-dimensional, axisymmetric model is used to analyse the spot welding process using both the actual current waveform and the corresponding rms value as inputs. The computed weld dimensions show better predictions with the instantaneous current waveform as input rather than the corresponding rms value.
Effect of vibration on weld metal hardness and toughness
Authors: Pučko B. , Gliha V.
Published: May 2005

Vibration of welded parts is usually applied to achieve effects similar to thermal stress relief. With vibration, it is not only residual stresses that are affected. Using two different welding processes, the influence of vibration on hardness and toughness of the weld was measured. For each welding process, two series of Charpy specimens were made over the temperature range from -60 to +20°C. The only difference between the two series was in performing welding with or without vibration. Slight differences in weld metal hardness were observed. Toughness measurements show an increase in impact toughness and a significant increase in fracture toughness in samples which were vibrated during welding.
Welding of AA6061-(Al2O3)p composite: Effect of weld process variables and post-welding heat treatment on microstructure and mechanical properties
Authors: de Salazar J. M. Gómez , Soria A. , Barrena M. I.
Published: May 2005

Metal–matrix composites reinforced with Al2O3 particles combine the properties of the matrix (ductility and toughness) with the ceramic properties of the reinforcements (high strength). However, their wide application as structural materials requires a proper development of their joint process. The present work describes the results obtained from microstructural (optical and scanning electron microscopy) and mechanical evaluation (hardness and tensile tests) of the welded aluminium–matrix composite (AA6061) reinforced with 10% and 20% volume fraction Al2O3 particles (W6A10 and W6A20, respectively) using the MIG (metal inert gas) welding process and ER5356 (AlMg5) as filler material. A characteristic of the welds carried out in composites is that the size of the melt pool is wider than in the unreinforced materials, for the same welding conditions. This is caused by the lower thermal conductivity of the composites. Furthermore, composites act as an insulator reducing the cooling rate of the bath. The thermal effect of welding on different types of joints results in a loss of the mechanical properties in the heat affected zones (HAZ). These properties can be recovered with post-welding heat treatment.
Hot cracking of welds on heat treatable aluminium alloys
Authors: Cheng C. M. , Chou C. P. , Lee I. K. , Lin H. Y.
Published: May 2005

The Spot Varestraint test was used to evaluate the hot cracking susceptibility of several aluminium alloys namely 6061-T6, 6061-T6 (H), 7075-T6, 7075-T6 (H). The effects of augment strain, the number of thermal cycles and cold working (rolling) on the cracking susceptibility were investigated, and the total crack length was used to evaluate the hot cracking susceptibility. The results indicate that the number of thermal cycles is irrelevant to the hot cracking susceptibility in the weld fusion zone, but does affect this susceptibility in the heat affected zone (HAZ). More thermal cycles correspond to larger hot cracks in the HAZ, especially in the weld metal HAZ. The hot cracking susceptibility of materials increased with augment strain in both the fusion zone and the HAZ. Cold working of the materials can reduce their hot cracking susceptibility. The hot cracking susceptibility of 7075-T6 aluminium alloys is higher than that of 6061-T6. There was significant Cu segregation in the HAZ of 7075-T6 aluminium alloy, resulting in a higher susceptibility to hot cracking in this zone.
Effects of in situ nickel particle addition on the microstructure and microhardness of Sn–Ag solder
Authors: Lee H. T. , Lee Y. H.
Published: May 2005

In this study, various amounts of Ni particles were added in situ to Sn–3·5 wt-%Ag lead free solder to form new composite solders. Copper substrates were then dipped into these solders and aged at 150°C for 0, 25, 225, or 1000 h. The microstructure and microhardness of the as solidified solder and the aged solder/copper couples were investigated. Experimental results revealed that the addition of Ni particles increased the microhardness of the composite solder. Ni additions of less than 3 wt-% yielded a microstructure of β-Sn grains surrounded by a eutectic mixture of Ag3Sn and a Sn rich matrix. An intermetallic compound of Ni3Sn4 particles was dispersed throughout the eutectic. For 5 wt-%Ni addition, the Ni3Sn4 phase and the remaining Ni particles were agglomerated. In the case of copper substrate dipped with a thick layer of composite solder, water quenched and then aged at 150°C, the induced (Ni, Cu)3Sn4 particles coarsened and agglomerated. Additionally, the intermetallic (Cu, Ni)6Sn5 compound layer formed at the solder/Cu interface thickened with increasing Ni content.
New general double ellipsoid heat source model
Authors: Hongyuan Fang , Qingguo Meng , Wenli Xu , Shude Ji
Published: May 2005

Based on the tridimensional Gauss distribution of power density, a general double ellipsoid welding heat source model has been developed. This model not only consists of all the characteristics of a double ellipsoid model, but also can deal with the situation where, under an external disturbance, the arc's backbone is not perpendicular to the work surface. This general double ellipsoid model is validated by measured results of the temperature field during twin wire welding. Using the non-linear finite element software Marc, the temperature field during twin wire welding was calculated using both the double ellipsoid heat source and the general double ellipsoid heat source. The thermal cycling curves and the weld pool cross-section obtained by the general double ellipsoid heat source tally well with the experimental results.
Microstructures of gas metal arc weld metal of 950 MPa class steel
Authors: Gouda M. , Takahashi M. , Ikeuchi K.
Published: May 2005

The effects of shielding gas composition on the properties and microstructure of single pass weld metals produced by GMA (gas metal arc) groove welding of 950 MPa class steel plates have been investigated. The shielding gas employed was a mixture of argon (Ar) and carbon dioxide (CO2) (0–25%), and the weld heat input was ∼3 kJ mm. With increasing CO2 content, the hardness of the weld metal decreased from 380 HV to 280 HV, and the absorbed energy of the Charpy impact test decreased from 130 J to 90 J. The microstructures of the weld metal, consisting primarily of low carbon martensite and carbide free bainite, became more bainitic as the CO2 content of the shielding gas was increased. It was also found that the MA constituent, embrittling microstructure, was formed in the granular bainitic area, the volume fraction of which increased with the CO2 content of the shielding gas.
Joining phenomena during friction stage of A7075-T6 aluminium alloy friction weld
Authors: Kimura M. , Kusaka M. , Seo K. , Fuji A.
Published: May 2005

This paper describes the effect of friction welding conditions on joining phenomena during the friction stage of type 7075-T6 aluminium alloy (A7075) friction welds. The friction torque had wear and seizure stages until the initial peak torque when A7075 was welded under high friction speed and low friction pressure, i.e. 27 · 5 rev s−1 and 30 MPa. Initial seizure and joining began at the central region (centre axis) of the welded interface, and extended towards the peripheral region (outer surface). On the other hand, when A7075 was welded under high friction speed and high friction pressure, i.e. 27 · 5 rev s−1 and 90 MPa, almost no wear stage existed before the initial peak torque. Initial seizure and joining began at the peripheral region of the welded interface and extended towards the central region. Then, the friction torque reached an initial peak torque when the welded interface was joined completely and upsetting of both base metals started. As a conclusion, the joining mechanism of A7075 friction welding was similar to that of low carbon steel.
Development of functional human blood and immune systems in NOD/SCID/IL2 receptor γ chainnull mice
Authors: Ishikawa Fumihiko , Yasukawa Masaki , Lyons Bonnie , Yoshida Shuro , Miyamoto Toshihiro , Yoshimoto Goichi , Watanabe Takeshi , Akashi Koichi , Shultz Leonard D. , Harada Mine
Published: May 2005

Here we report that a new nonobese diabetic/severe combined immunodeficient (NOD/SCID) mouse line harboring a complete null mutation of the common cytokine receptor γ chain (NOD/SCID/interleukin 2 receptor [IL2r] γnull) efficiently supports development of functional human hemato-lymphopoiesis. Purified human (h) CD34+ or hCD34+hCD38– cord blood (CB) cells were transplanted into NOD/SCID/IL2rγnull newborns via a facial vein. In all recipients injected with 105 hCD34+ or 2 × 104 hCD34+hCD38– CB cells, human hematopoietic cells were reconstituted at approximately 70% of chimerisms. A high percentage of the human hematopoietic cell chimerism persisted for more than 24 weeks after transplantation, and hCD34+ bone marrow grafts of primary recipients could reconstitute hematopoiesis in secondary NOD/SCID/IL2rγnull recipients, suggesting that this system can support self-renewal of human hematopoietic stem cells. hCD34+hCD38– CB cells differentiated into mature blood cells, including myelomonocytes, dendritic cells, erythrocytes, platelets, and lymphocytes. Differentiation into each lineage occurred via developmental intermediates such as common lymphoid progenitors and common myeloid progenitors, recapitulating the steady-state human hematopoiesis. B cells underwent normal class switching, and produced antigen-specific immunoglobulins (Igs). T cells displayed the human leukocyte antigen (HLA)–dependent cytotoxic function. Furthermore, human IgA-secreting B cells were found in the intestinal mucosa, suggesting reconstitution of human mucosal immunity. Thus, the NOD/SCID/IL2rγnull newborn system might be an important experimental model to study the human hemato-lymphoid system.
T cell–mediated suppression of angiogenesis results in tumor protective immunity
Authors: Zhou He , Luo Yunping , Mizutani Masato , Mizutani Noriko , Reisfeld Ralph A. , Xiang Rong
Published: May 2005

Antiangiogenic intervention is known to inhibit tumor growth and dissemination by attacking the tumor's vascular supply. Here, we report that this was achieved for the first time using an oral DNA minigene vaccine against murine vascular endothelial growth factor receptor 2 (FLK-1), a self-antigen overexpressed on proliferating endothelial cells in the tumor vasculature. Moreover, we identified the first H-2Db–restricted epitope, FLK400 (VILT-NPISM), specifically recognized by cytotoxic T lymphocytes (CTLs). Such CTLs were capable of killing FLK-1+ endothelial cells, resulting in suppression of angiogenesis and long-lived tumor protection. The specificity of this immune response was indicated because the DNA vaccine encoding the entire FLK-1 gene also induced a FLK400-specific CTL response. This minigene vaccine strategy provides a more flexible alternative to whole-gene vaccination and facilitates in-depth mechanism studies to tailor DNA vaccines for optimal T-cell activation and tumor protection.
Antigen-specific T-cell memory is preserved in children treated for acute lymphoblastic leukemia
Authors: Haining W. Nicholas , Neuberg Donna S. , Keczkemethy Heather L. , Evans John W. , Rivoli Stephen , Gelman Rebecca , Rosenblatt Howard M. , Shearer William T. , Guenaga Javier , Douek Daniel C. , Silverman Lewis B. , Sallan Stephen E. , Guinan Eva C. , Nadler Lee M.
Published: May 2005

Despite profound T-cell immunodeficiency, most patients treated with chemotherapy do not succumb to infection. The basis for residual protective immunity in lymphopenic patients is not known. We prospectively measured T-cell numbers, thymopoiesis, and T-cell memory in 73 children undergoing a 2-year chemotherapy regimen for acute lymphoblastic leukemia (ALL) and compared them to an age-matched cohort of 805 healthy children. Most patients had profound defects in CD4 and CD8 T-cell numbers at diagnosis that did not recover during the 2 years of therapy. Thymic output and the fraction of naive T cells were significantly lower than in healthy controls. However, the remaining T-cell compartment was enriched for antigen-experienced, memory T cells defined both by phenotype and by function. This relative sparing of T-cell memory may, in part, account for the maintenance of protective immunity in lymphopenic patients treated for ALL. Moreover, because the memory T-cell compartment is least affected by ALL and its treatment, strategies to induce immunity to pathogens or tumor antigens in cancer patients may be most successful if they seek to expand pre-existing memory T cells. (Blood. 2005; 106:1749-1754)
Phylogenetic reconstruction of ancestral character states for gene expression and mRNA splicing data
Authors: Rossnes Roald , Eidhammer Ingvar , Liberles David A
Published: May 2005

Background

As genomes evolve after speciation, gene content, coding sequence, gene expression, and splicing all diverge with time from ancestors with close relatives. A minimum evolution general method for continuous character analysis in a phylogenetic perspective is presented that allows for reconstruction of ancestral character states and for measuring along branch evolution.

Results

A software package for reconstruction of continuous character traits, like relative gene expression levels or alternative splice site usage data is presented and is available for download at http://www.rossnes.org/phyrex. This program was applied to a primate gene expression dataset to detect transcription factor binding sites that have undergone substitution, potentially having driven lineage-specific differences in gene expression.

Conclusion

Systematic analysis of lineage-specific evolution is becoming the cornerstone of comparative genomics. New methods, like phyrex, extend the capabilities of comparative genomics by tracing the evolution of additional biomolecular processes.
Potential genetic modifiers of the cystic fibrosis intestinal inflammatory phenotype on mouse chromosomes 1, 9, and 10
Authors: Norkina Oxana , De Lisle Robert C
Published: May 2005

Background

Although cystic fibrosis is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, the severity of disease is highly variable indicating the influence of modifier genes. The intestines ofCftrdeficient mice (CF mice: Cftrtm1Unc) are prone to obstruction by excessive mucus accumulation and are used as a model of meconium ileus and distal intestinal obstruction syndrome. This phenotype is strongly dependent on the genetic background of the mice. On the C57Bl/6 background, the majority of CF mice cannot survive on solid mouse chow, have inflammation of the small intestine, and are about 30% smaller than wild type littermates. In this work potential modifier loci of the CF intestinal phenotype were identified.

Results

CF mice on a mixed genetic background (95% C57Bl/6 and 5% 129Sv) were compared to CF mice congenic on the C57Bl/6 background for several parameters of the intestinal CF phenotype. CF mice on the mixed background exhibit significantly greater survival when fed dry mouse chow, have reduced intestinal inflammation as measured by quantitative RT-PCR for marker genes, have near normal body weight gain, and have reduced mucus accumulation in the intestinal crypts. There was an indication of a gender effect for body weight gain: males did not show a significant improvement at 4 weeks of age, but were of normal weight at 8 weeks, while females showed improvement at both 4 and 8 weeks. By a preliminary genome-wide PCR allele scanning, three regions were found to be potentially associated with the milder phenotype. One on chr.1, defined by marker D1Mit36, one on chr. 9 defined by marker D9Mit90, and one on chr. 10, defined by marker D10Mit14.

Conclusion

Potential modifier regions were found that have a positive impact on the inflammatory phenotype of the CF mouse small intestine and animal survival. Identification of polymorphisms in specific genes in these regions should provide important new information about genetic modifiers of the CF intestinal phenotype.
A generally applicable validation scheme for the assessment of factors involved in reproducibility and quality of DNA-microarray data
Authors: van Hijum Sacha AFT , de Jong Anne , Baerends Richard JS , Karsens Harma A , Kramer Naomi E , Larsen Rasmus , den Hengst Chris D , Albers Casper J , Kok Jan , Kuipers Oscar P
Published: May 2005

Background

In research laboratories using DNA-microarrays, usually a number of researchers perform experiments, each generating possible sources of error. There is a need for a quick and robust method to assess data quality and sources of errors in DNA-microarray experiments. To this end, a novel and cost-effective validation scheme was devised, implemented, and employed.

Results

A number of validation experiments were performed on Lactococcus lactis IL1403 amplicon-based DNA-microarrays. Using the validation scheme and ANOVA, the factors contributing to the variance in normalized DNA-microarray data were estimated. Day-to-day as well as experimenter-dependent variances were shown to contribute strongly to the variance, while dye and culturing had a relatively modest contribution to the variance.

Conclusion

Even in cases where 90 % of the data were kept for analysis and the experiments were performed under challenging conditions (e.g. on different days), the CV was at an acceptable 25 %. Clustering experiments showed that trends can be reliably detected also from genes with very low expression levels. The validation scheme thus allows determining conditions that could be improved to yield even higher DNA-microarray data quality.
Age related clinical features of childhood Coeliac disease in Australia
Authors: Stone Monique L , Bohane Timothy D , Whitten Kylie E , Tobias Vivienne H , Day Andrew S
Published: May 2005

Background

To describe the presenting clinical features of coeliac disease in a single paediatric centre, and to determine if the presenting features vary with age.

Methods

A review was conducted of children who had been referred with clinical suspicion of coeliac disease to the paediatric gastroenterology department of a tertiary paediatric hospital in Sydney, Australia. Coeliac disease was defined using standard histological criteria. Medical records were reviewed retrospectively.

Results

Clinical data were available for 74 cases of proven coeliac disease. Only 9% of patients were less than 2 years of age at diagnosis. Pre-school children (age <5 years) presented with different symptoms to school children (age ≥ 5 years). The most common presenting features in younger children were diarrhoea, irritability and weight loss. However, in older children, abdominal pain was the most common presenting feature.

Conclusion

We found a significant difference in the clinical features of coeliac disease in pre-school compared to school age children.
Epidemiologic measures and policy formulation: lessons from potential outcomes
Authors: Greenland Sander
Published: May 2005

This paper provides a critique of the common practice in the health-policy literature of focusing on hypothetical outcome removal at the expense of intervention analysis. The paper begins with an introduction to measures of causal effects within the potential-outcomes framework, focusing on underlying conceptual models, definitions and drawbacks of special relevance to policy formulation based on epidemiologic data. It is argued that, for policy purposes, one should analyze intervention effects within a multivariate-outcome framework to capture the impact of major sources of morbidity and mortality. This framework can clarify what is captured and missed by summary measures of population health, and shows that the concept of summary measure can and should be extended to multidimensional indices.