bluuebunny/crossref_metadata_2025 huggingface dataset:
Packaging of chemicals in the defensive secretory glands of the sea hareAplysia californica
Authors: Johnson Paul M. , Kicklighter Cynthia E. , Schmidt Manfred , Kamio Michiya , Yang Hsiuchin , Elkin Dimitry , Michel William C. , Tai Phang C. , Derby Charles D.
Published: December 2005

Sea hares protect themselves from predatory attacks with several modes of chemical defenses. One of these is inking, which is an active release of a protective fluid upon predatory attack. In many sea hares including Aplysia californica and A. dactylomela, this fluid is a mixture of two secretions from two separate glands, usually co-released: ink,a purple fluid from the ink gland; and opaline, a white viscous secretion from the opaline gland. These two secretions are mixed in the mantle cavity and directed toward the attacking predator. Some of the chemicals in these secretions and their mechanism of action have been identified. In our study,we used western blots, immunocytochemistry, amino acid analysis, and bioassays to examine the distribution of these components: (1) an l-amino acid oxidase called escapin for A. californica and dactylomelin-P for A. dactylomela, which has antimicrobial activity but we believe its main function is in defending sea hares against predators that evoke its release; and (2) escapin's major amino acid substrates - l-lysine and l-arginine. Escapin is exclusively produced in the ink gland and is not present in any other tissues or secretions. Furthermore, escapin is only sequestered in the amber vesicles of the ink glandand not in the red-purple vesicles, which contain algal-derived chromophores that give ink its distinctive purple color. The concentration of escapin and dactylomelin-P in ink, both in the gland and after its release, is as high as 2 mg ml-1, or 30 μmol ml-1, which is well above its antimicrobial threshold. Lysine and arginine (and other amino acids) are packaged into vesicles in the ink and opaline glands, but arginine is present in ink and opaline at <1 mmol l-1 and lysine is present in ink at <1 mmol l-1 but in opaline at 65 mmol l-1. Our previous results showed that both lysine and arginine mediate escapin's bacteriostatic effects, but only lysine mediates its bactericidal effects. Given that escapin's antimicrobial effects require concentrations of lysine and/or arginine >1 mmol l-1, our data lead us to conclude that lysine in opaline is the primary natural substrate for escapin in ink. Furthermore, packaging of the enzyme escapin and its substrate lysine into two separate glands and their co-release and mixing at the time of predatory attack allows for the generation of bioactive defensive compounds from innocuous precursors at the precise time they are needed. Whether lysine and/or arginine are substrates for escapin's antipredatory functions remains to be determined.
Running over rough terrain: guinea fowl maintain dynamic stability despite a large unexpected change in substrate height
Authors: Daley Monica A. , Usherwood James R. , Felix Gladys , Biewener Andrew A.
Published: December 2005

In the natural world, animals must routinely negotiate varied and unpredictable terrain. Yet, we know little about the locomotor strategies used by animals to accomplish this while maintaining dynamic stability. In this paper, we perturb the running of guinea fowl with an unexpected drop in substrate height (ΔH). The drop is camouflaged to remove any visual cue about the upcoming change in terrain that would allow an anticipatory response. To maintain stability upon a sudden drop in substrate height and prevent a fall, the bird must compensate by dissipating energy or converting it to another form. The aim of this paper is to investigate the control strategies used by birds in this task. In particular, we assess the extent to which guinea fowl maintain body weight support and conservative spring-like body dynamics in the perturbed step. This will yield insight into how animals integrate mechanics and control to maintain dynamic stability in the face of real-world perturbations. Our results show that, despite altered body dynamics and a great deal of variability in the response, guinea fowl are quite successful in maintaining dynamic stability, as they stumbled only once(without falling) in the 19 unexpected perturbations. In contrast, when the birds could see the upcoming drop in terrain, they stumbled in 4 of 20 trials(20%, falling twice), and came to a complete stop in an additional 6 cases(30%). The bird's response to the unexpected perturbation fell into three general categories: (1) conversion of vertical energy(EV=EP+EKv) to horizontal kinetic energy (EKh), (2) absorption of EV through negative muscular work(-ΔEcom), or (3) converting EPto vertical kinetic energy (EKv), effectively continuing the ballistic path of the animal's center of mass (COM) from the prior aerial phase. However, the mechanics that distinguish these categories actually occur along a continuum with varying degrees of body weight support and actuation by the limb, related to the magnitude and direction of the ground reaction force(GRF) impulse, respectively. In most cases, the muscles of the limb either produced or absorbed energy during the response, as indicated by net changes in COM energy (Ecom). The limb likely begins stance in a more retracted, extended position due to the 26 ms delay in ground contact relative to that anticipated by the bird. This could explain the diminished decelerating force during the first half of stance and the exchange between EP and EK during stance as the body vaults over the limb. The varying degree of weight support and energy absorption in the perturbed step suggests that variation in the initial limb configuration leads to different intrinsic dynamics and reflex action. Future investigation into the limb and muscle mechanics underlying these responses could yield further insight into the control mechanisms that allow such robust dynamic stability of running in the face of large, unexpected perturbations.
Information governance standards for managing e-health information
Authors: Huston Janis L
Published: December 2005

Integrity of patient information, from both a quality and a security perspective, is critical to patient care. In the UK, the information governance initiative of the National Health Service (NHS) provides a framework to monitor and control the management of confidential patient data. Information governance standards grew out of the Data Accreditation Programme, first proposed in the 1998 NHS document Information for Health. The Data Accreditation Programme was based on a three-stage assessment of data quality in acute hospitals. Stage one required internal review of policy and procedures for data input into computerized patient administration systems. Stage two involved an external audit to verify compliance with the standards. Stage three mandated audits of data outputs, focusing on clinical coding quality. Before stage three of the programme was fully implemented, the standards were incorporated into the information governance initiative, in which standards were expanded to include primary care and other health-care settings. These standards address many information management issues, including security and data quality, which are key concerns in telemedicine and e-health applications. Compliance is essential for the successful implementation of the NHS Care Records Service, which will allow sharing of electronically stored patient information across the UK.
The clinical champion role in the development of a successful telehealth wound care project for remote Australia
Authors: Ellis Isabelle
Published: December 2005

The role of a clinical champion in a wound care project was examined in terms of an emancipatory processes framework. During the project the role changed significantly, as the needs of the project changed. In the early phase of the project, the clinical champion's role was that of team leader. During the middle phase of the project, the clinical champion's role changed to health services advocate and coach. During the final phase of the project, the clinical champion's role changed again, to that of salesperson and academic. Experience with the clinical issue being addressed by the new service, and clear motivation to complete the project, thereby seeing the new service established, allowed the clinical champion to motivate the team to overcome the difficulties in the change process.
Transmission of online digital documents for the health assessment component of e-visa applications
Authors: Macdermott Anthony , Crowe Bernard
Published: December 2005

Up to 350,000 health assessments are conducted annually for persons seeking a visa to enter Australia. Health screening is conducted by accredited panel doctors and radiologists in the visa applicant's home country. Their findings are forwarded to the appropriate government department in Australia. The move to an e-visa system, with certain visas being available via the Internet, has seen the introduction of a compatible electronic health assessment system. An online system to support health assessment processing was implemented in two stages. The first, eHealthl, has been in operation since July 2002 and the second, eHealth2, commenced in November 2003. In a pilot trial in Singapore during 2003 and 2004, 5000 student visa applications (87%) were lodged through the eHealth2 system. The main advantage of the eHealth2 process is the rapid transmission of a digital photograph and X-ray image. This avoids the delay of sending documents and films by post. The success of the pilot has led to the expansion of eHealth2 to other electronic visa sectors, such as working holiday makers, long-stay business people and visitors. The eHealth2 system is fully operational in Singapore, Hong Kong, Japan, South Korea and Taiwan.
Web-based patient records and treatment guidelines in paediatric oncology
Authors: Hira Adilson Yuuji , Lopes Thiago Tognoli , De Mello André Nebel , Filho Vicente Odone , Zuffo Marcelo Knörich , De Deus Lopes Roseli
Published: December 2005

We have established a Web-based system in Brazil offering health information in childhood cancer and services such as electronic patient records and treatment protocols. The system was based on open-source software. The database has records for about 3200 patients from 30 Brazilian hospitals. An evaluation by doctors from the six hospitals comprising the Neuroblastoma Cooperative Group was positive, mainly because the system allows easy online access, but also because the electronic register performs data validation when information is inserted. Our experience shows that it is possible to use a Web-based system to provide paediatric cancer services at a distance.
Evaluation of the Western Australian Department of Health telehealth project
Authors: Dillon Eric , Loermans Jozef , Davis Dale , Xu Cathy
Published: December 2005

In 1999, the Department of Health in Western Australia began a telehealth project, which finished in 2004. The 75 videoconferencing sites funded by the project were part of a total state-wide videoconference network of 104 sites. During the period from January 2002 to December 2003, a total of 3266 consultations, case reviews and patient education sessions took place. Clinical use grew to 30% of all telehealth activity. Educational use was approximately 40% (1416 sessions) and management use was about 30% (1031 sessions). The average overhead cost per telehealth session across all regions and usage types was ɇA192. Meaningful comparisons of the results of the present study with other public health providers were difficult, because many of the available Websites on telehealth were out of date. Despite the successful use of telehealth to deliver clinical services in Western Australia, sustaining the effort in the post-project phase will present significant challenges.
Telemedical treatment at home of diabetic foot ulcers
Authors: Clemensen Jane , Larsen Simon B , Ejskjaer Niels
Published: December 2005

The treatment of diabetic foot ulcers may not always be well organized and not all patients have access to expert evaluation. We investigated the use of telemedicine to enable a visiting nurse (in the patient's home) to coordinate the treatment with experts (at the hospital). The equipment consisted of a UMTS videophone and an Internet-based patient record. Field studies were carried out at the outpatient clinic and by following visiting nurses. A total of 15 participants were invited to five workshops and experiments held in our laboratories, at the hospital, and between hospital and patients’ homes. Finally, in a pilot test, five patients were offered three teleconsultations at their homes in lieu of visits to the hospital. Preliminary results were promising: (1) both clinicians and patients found the equipment easy to use; (2) the doctor could prescribe treatment at a distance; (3) the visiting nurse had realtime contact with the hospital and treatment could begin immediately according to the doctor's orders; (4) the patient saved time in not having to travel to the hospital.
Challenges for implementing wireless hand-held technology in health care: Views from selected Queensland nurses
Authors: Gururajan Raj , Moloney Clint , Soar Jeffrey
Published: December 2005

Many health-care providers in Australia are exploring the use of wireless technology to improve service delivery. It appears that the solutions so far have been dictated by the hardware vendors and that the business case is yet to drive the implementations. A focus group discussion was facilitated with eight senior management staff involved in health care in Western Australia. This resulted in a set of challenges, which were used to invite opinions from nursing staff in Queensland. A total of 31 interviews were conducted. The analysis returned a set of 63 themes, which were grouped. These groupings reflected the challenges as lack of user-friendly applications, unreliable technology, substandard testing, shortage of staff, concerns for security, reliance on technology, existing problems, work schedule, training, outdated health policy, coverage of wireless links, confidentiality and lack of awareness. The interviews clearly indicated the need for training and awareness procedures. The present study provides some of the information necessary to realize an enterprise-wide implementation of wireless technology.
Case management and adherence to an online disease management system
Authors: Robertson Lucy , Smith Michael , Tannenbaum Dennis
Published: December 2005

Non-adherence to treatment presents a significant obstacle to achieving favourable health outcomes. We have studied consumers’ adherence to an online disease management system for depression, called Recovery Road. Recovery Road was implemented on a pilot basis for mental health care in Western Australia. Recovery Road was available for use by consumers and clinicians to augment usual treatment. One hundred and thirty consumers who had been diagnosed with major depression were enrolled. Consumers who used Recovery Road (n=98) were provided with education, progress monitoring, e-consultation, e-diary and online evidenced-based therapy. Consumers received either standard, automated adherence reminders by email (n = 69), or case management, which included personalized email and telephone follow-up in response to non-adherence (n = 29). After the first eight sessions, the adherence was 84% in the case management group and 55% in the automatic reminders group. The results suggest that case management increases adherence to online disease management systems.
Establishment of the Brazilian telehealth network for paediatric oncology
Authors: Hira Adilson Yuuji , Lopes Thiago Tognoli , De Mello André Nebel , Filho Vicente Odone , Zuffo Marcelo Knörich , De Deus Lopes Roseli
Published: December 2005

A telemedicine network has been established in Brazil to support distance medical practice in paediatric oncology. ONCONET comprises a national network of universities, research institutes and medical institutions. The system is Web-based and hosted on a high-performance computing infrastructure based on clusters of computers. It is based on open-source software, designed to provide high performance, fault tolerance and high availability. The ONCONET began operation in 2004. Currently, 30 hospitals affiliated to the Brazilian Society for Paediatric Oncology are users of the ONCONET. Six hospitals are connected by broadband access through the National Education and Research Network and 24 by conventional Internet access. The Multimedia Patients Registry also became operational in 2004, and its database contains information on 3200 patients from the 30 hospitals. The technological platform was notable for its low production cost. It thus appears to be a sustainable solution to the problem of delivering continuing medical education in a large country with widely dispersed health professionals.
Delivery of child development services by videoconferencing: A review of four years’ experience in Queensland
Authors: Bailey Maggie A , Smith Anthony C , Fitzgerald Antoinette , Taylor Eileen
Published: December 2005

In 2001 the Child Development Unit (CDU) in Brisbane piloted a series of monthly multidisciplinary case discussions via videoconference in the area of child development. During 2001 two sessions were provided; during 2004 there were 40. The substantial growth in 2004 was due to the expansion of child development services to include special interest group meetings and multipoint case conference meetings. In 2004, a total of 49 h of videoconferencing was conducted. The average session length was 75 min. Education and training sessions were delivered to 32 hospitals and health centres in Queensland and northern New South Wales. The maximum number of sites involved during a single videoconference was 25. The average number of attendees for each videoconference was five per site, including allied health staff, nurses and paediatricians. The delivery of child development services via videoconference has been shown to be useful in Queensland, especially for allied health staff working in regional and remote areas. The growth of the programme indicates its acceptance as a mainstream child development service in Queensland.
Auto TeleCare – understanding the failures and successes of small business in telehealth
Authors: Mcmahon David
Published: December 2005

Auto TeleCare provided an automatic daily telephone service for people living alone. The business used an interactive voice response (IVR) system to call clients at a set time each day. The clients were required to press a button on their telephone to listen to a message (e.g. joke of the day), thereby indicating that they were alright. If the client did not respond, staff would call the given list of contacts to check on the client's welfare. The service was first offered in December 2003 and there was a lot of interest from clients and health-care groups. Although the technology was sophisticated, it was very simple for the clients to use. However, it was the marketing and advertising costs of the business that in the end proved to be too costly. The number of clients required for commercial viability was calculated to be 3000, and after nearly 15 months of business it was decided to close the business.
Bad me paranoia in early psychosis: A relatively rare phenomenon
Authors: Fornells‐Ambrojo Miriam , Garety Philippa A.
Published: December 2005

Purpose. The aim of this study was to follow up Trower and Chadwick's (1995) proposal that there are two types of paranoia: poor me paranoia, in which the persecution is believed to be undeserved, and bad me paranoia, in which the persecution is seen as a deserved punishment.

Method. A cross‐sectional design was used. A group of 40 participants with early psychosis, who were experiencing persecutory delusions, were assessed using a semi‐structured interview on the content of their beliefs.

Results. An extremely low rate of bad me paranoia was found in the sample of participants with early psychosis.

Conclusions. People with persecutory delusions who are in the initial stages of their illness do not tend to believe that they are being justifiably punished. Stigma and depression are put forward as tentative explanations of the development of this evaluative belief with time.
Opposition to redistributive employment policies for women: The role of policy experience and group interest
Authors: Garcia Donna M. , Desmarais Serge , Branscombe Nyla R. , Gee Stephanie S.
Published: December 2005

We examined whether group interest affected ideological beliefs and attitudes towards redistributive policies among men and women. We found that group interest influenced meritocratic and neo‐sexist beliefs and support for gender‐based affirmative action and comparable worth policies. Men and women differed in their ideological beliefs and support for the redistributive policies only when they had conscious experience with these policies. Those with policy experience expressed policy attitudes that corresponded with their gender group's interests, while those lacking such experience did not. We also noted group interest effects within each gender: men who had conscious experience with the policies expressed more opposition and greater neo‐sexism and meritocratic beliefs than did men who were not consciously experienced with these policies. In contrast, consciously experienced women expressed more policy support than did their not consciously experienced counterparts. Overall, our findings indicate that group interest is an important determinant of policy attitudes and related ideological beliefs.
Clearing the air: The effect of experimenter race on target's test performance and subjective experience
Authors: Marx David M. , Goff Phillip Atiba
Published: December 2005

According to stereotype threat theory (Steele, 1997), stereotyped targets underperform on challenging tests, in part because they are worried about being viewed in terms of the negative stereotype that they are intellectually inferior. How then are the negative effects of stereotype threat reduced for stereotyped targets? To examine this issue, a study was conducted to investigate whether stereotype threat's adverse effects are reduced when a Black experimenter administers a verbal test to Black participants. We further examined the question of whether Black participants have a subjective awareness of stereotype threat. Results showed that when a Black experimenter gave a verbal test to Black participants, they did not suffer the typical performance decrements associated with stereotype threat. Additionally, results supported the hypothesis that Black participants have conscious access to the experience of stereotype threat and that this effect is partially mediated by their endorsement of the stereotype.
Group‐based guilt as a predictor of commitment to apology
Authors: McGarty Craig , Pedersen Anne , Wayne Leach Colin , Mansell Tamarra , Waller Julie , Bliuc Ana‐Maria
Published: December 2005

Whether the Australian government should officially apologize to Indigenous Australians for past wrongs is hotly debated in Australia. The predictors of support amongst non‐Indigenous Australians for such an apology were examined in two studies. The first study (N=164) showed that group‐based guilt was a good predictor of support for a government apology, as was the perception that non‐Indigenous Australians were relatively advantaged. In the second study (N=116) it was found that group‐based guilt was an excellent predictor of support for apology and was itself predicted by perceived non‐Indigenous responsibility for harsh treatment of Indigenous people, and an absence of doubts about the legitimacy of group‐based guilt. National identification was not a predictor of group‐based guilt. The results of the two studies suggest that, just as individual emotions predict individual action tendencies, so group‐based guilt predicts support for actions or decisions to be taken at the collective level.
How the past weighs on the present: Social representations of history and their role in identity politics
Authors: Liu James H. , Hilton Denis J.
Published: December 2005

Socially shared representations of history have been important in creating, maintaining and changing a people's identity. Their management and negotiation are central to interethnic and international relations. We present a narrative framework to represent how collectively significant events become (selectively) incorporated in social representations that enable positioning of ethnic, national and supranational identities. This perspective creates diachronic (temporal) links between the functional (e.g. realistic conflict theory), social identity, and cognitive perspectives on intergroup relations. The charters embedded in these representations condition nations with similar interests to adopt different political stances in dealing with current events, and can influence the perceived stability and legitimacy of social orders. They are also instrumental in determining social identity strategies for reacting to negative social comparisons, and can influence the relationships between national and ethnic identities.
Attention, task difficulty, and ADHD
Authors: Nigg Joel T.
Published: December 2005

Comments on analysis of attention tasks in Attention Deficit Hyperactivity Disorder (ADHD) provided by Wilding (2005) points out that whereas many regulatory functions, including alertness or arousal, appear to be impaired in ADHD, demonstrating basic attention deficits in selection or orienting functions in the disorder has proven difficult. Yet several issues remain to be addressed in the field with regard to attentional function in ADHD. These include the need for further scrutiny of effects of perceptual load, the psychometric problem of differential task difficulty and differential deficit, relative value of complex versus simple tasks, and consideration of heterogeneity in ADHD. Heterogeneity pertains both to additional analysis of ADHD subtypes, in light of speculation that the Inattentive type may be characterized by true attention problems, and to newer analyses of potential distinct etiological groups within subtype. New analyses of attentional operations have a role to play in these future directions.
"Got Race?" The Production of Haole and the Distortion of Indigeneity in the Rice Decision
Authors: Rohrer Judy
Published: December 2005

This paper is part of a larger project that explores haole (white people, foreigners) as a colonial form of whiteness in Hawai'i—as a dynamic social assemblage. Haole was forged and reforged in over two centuries of colonization, and it must be understood through that history. I use the recent Supreme Court decision in Harold F Rice v Benjamin J Cayetano, 528 US 495 (2000 ), as an entry point into the interrogation of haole. Framed by the dominant discourse, the case appeared to be about Native Hawaiians (asking questions about who they are and what rights they have), and not about haole (assuming there are no questions as to who they are and what rights they have).

The Rice case illustrates how Western law renders indigenous claims inarticulable by racializing native peoples, while simultaneously normalizing white subjectivity by insisting on a color-blind ideology. The inherent contradiction in these two positions—race matters/race does not matter—is played out in the frictions surrounding the Rice decision and is evidence of the cracks in the hegemony of Western law that complicate any easy binary of colonizer–colonized. Through an analysis of Rice, I explore how the Western legal framework is set up to accept the teleological narrative of the development, to problematize native identity, and to naturalize white subjectivity. I then broaden the lens to explore the ways Rice points to an epistemological disconnect between Western notions of the production of knowledge and indigenous articulations of the same.
The Jew Bill of 1753: Masculinity, Virility, and the Nation
Authors: Rabin Dana Y.
Published: December 2005

This study seeks to show that opposition to the Jewish Naturalization Act (26 Geo. II. c.26) with its images of Christianity, law, and property reveals a constitutive moment in the formation of Britain as a nation. The Act, which had passed both the Commons and the Lords, was repealed because of popular outcry. While the "Jew Bill" has been studied in the context of Anglo-Jewish history, this incident can also serve to illustrate several British political and cultural preoccupations of the mid-eighteenth century. I argue that the discourse about Jews in the pamphlets and prints highlights contemporary concerns about the deep religious and political divisions within the polity. The controversy around the Bill underscored the fissured nature of Christian Britain and recharged lingering English fears about rebellion and civil unrest so prominent in the seventeenth century. The contrast of a divided Britain and the representation of a cohesive Jewish nation presented a threat but also an opportunity for galvanizing a broad spectrum of political culture.
Oblique Subjects: A Common Germanic Inheritance
Authors: Eythorsson. Thorhallur , Baredal Johanna
Published: December 2005

We argue that subject-like obliques of the impersonal construction show behavioral properties
of syntactic subjects in Old Germanic, contrary to standard assumptions (Cole et al. 1980). Subject
tests, including control infinitives, reveal that subject-like obliques in Old and Early Middle
English, Old Swedish, and Old Norse-Icelandic exhibit behavioral properties of subjects, as they
do in Modern Icelandic and Faroese. We also present new data from Modern German, illustrating
the same syntactic behavior of corresponding arguments in that language. Thus, we conclude that
subject-like obliques exhibit behavioral properties of syntactic subjects from the earliest attested
Germanic period onwards. Our findings contradict the standard view that these arguments were
objects, which gradually acquired subject properties. We show that data from Gothic intended to
support the standard view has been misinterpreted. Given the validity of our findings there are
no grounds for reconstructing a stage at which subject-like obliques were objects in Germanic.
A Numerical Method for the Recovery of Local Potentials and Currents Due to Corrosion of Steel in Concrete
Authors: Kranc SC , Sagüés AA
Published: December 2005

Diagnostic electrical measurements intended to quantify the rate of corrosion often prove difficult to interpret due to the distribution of currents within the concrete electrolyte. In this paper an inverse method to recover estimates of local values for the potential and current density at the concrete-steel interface from measurements at the exterior surface is presented. An idealized model system has been investigated in a series of numerical experiments. Several example problems in corrosion diagnostics have been analyzed and the results compared favorably to direct solutions.
Use of Electrochemical Techniques to Assess Performance of Corrosion Protection Systems for Reinforced Concrete Structures—A Review
Authors: Islam M , Daily SF
Published: December 2005

Electrochemical methods for controlling corrosion of reinforcing steel in concrete involve techniques that interfere with the electrochemical reactions occurring on the embedded steel surface. Included in this category are cathodic protection, electrochemical chloride extraction, re-alkalization (for carbonation damage), and corrosion inhibitors. Assessing and monitoring the performance of these corrosion protection systems for steel in concrete can sometimes be challenging. Several techniques and devices are available. In recent years different electrochemical techniques have been utilized. The present paper discusses the use of the older devices and the more recently developed devices such as the “ladder” probe and the microprocessor controlled electrical resistance probe for evaluating and monitoring the performance of reinforced concrete corrosion protection systems. Remote monitoring options are also discussed.
Use of Broken Charpy V-notch Specimens from a Surveillance Program for Fracture Toughness Determination
Authors: Scibetta M , Lucon E , Chaouadi R , van Walle E , Gérard R
Published: December 2005

Broken Charpy specimens from the surveillance program of a Belgian nuclear power plant are used to obtain the fracture toughness in the transition regime using the master curve concept. Two approaches are used. The first one is based on the reconstitution of Charpy specimens that are subsequently precracked and tested in three-point bending. The second approach is an innovative one that makes use of miniature Compact Tension specimens, which are machined from the broken pieces of the original Charpy specimens. Both approaches lead to consistent results. The recently developed miniature Compact Tension design has the advantage to use less material and is less costly in terms of machining operation. For the material investigated in this research, the current regulation, based on a semi-empirical approach to obtain the lower bound fracture toughness, is demonstrated to be conservative as compared to the direct fracture toughness determination.
The History of Instrumented Impact Testing
Authors: Manahan MP , Siewert TA
Published: December 2005

Pendulum impact testing is widely known to have a history that extends back to the turn of the 20th century. To many researchers today, instrumentation of the impact test to acquire a load-time history, and thereby to provide important data in addition to absorbed energy, is usually considered to be a relatively recent development. However, our literature review has shown that starting from the earliest test machine development work, researchers have been interested in designing equipment capable of measuring both the energy expended in fracturing the specimen, and the force-deflection and energy-deflection curves. This paper recounts the early history of instrumented impact testing, and shows that it also extends back over 100 years. In fact, the earliest known paper on instrumented impact testing predates the first pendulum test machine publication by one year.
Use of Carbodiimides as Stabilizing Agents to Deliver Water—Labile Active Ingredients in Liquid Systems Including Aqueous Medium—Amitraz as a Case Study
Authors: Narayanan KS , Jon DI , Beestman G
Published: December 2005

Several active ingredients such as sulfonylureas and diimidines (Amitraz) are unstable in water. They undergo hydrolysis producing metabolites that are no longer biologically active. The rate of hydrolysis is a function of several factors, such as the solvent system, access to water, pH, temperature, ionic strength, and the types of emulsifiers used in the liquid matrices. Some of the active ingredients undergo rapid hydrolysis even with the residual water present in the emulsifier system in an organic emulsifiable concentrate formulation. It is therefore difficult to formulate such active ingredients in liquid delivery systems. Use of carbodiimides like Stabaxol I® (bis-2,6-diisopropylphenylcarbodiimide) as a water scavenger to stabilize oil-based formulations for Amitraz is well documented and is commercially practiced. We have found that unique combinations of carbodiimides with specific solvent-emulsifier-polymer blends in a buffered system can produce stable microemulsions of Amitraz in water. Such aqueous formulations with 200–500 ppm Amitraz in >99 % water, were stable with 95 % retention on accelerated storage at 50°C for two weeks. This data translates to greater than two years stability at room temperature. Such formulations may be extended to deliver sulfonylureas. We also observed that the concentrate and the matrix containing Stabaxol I® and emulsifiers can produce gels on storage, adversely affecting physical stability. We have identified several additives and alternatives to prevent gel formation enabling long-term storage stability of the matrix and the concentrate. Examples with supporting data will be provided. A rationale and proposed mechanism for the enhanced stability and potential biological activity will be discussed.
Simulation on the Decrease in Threshold Stress Intensity Factor (SIF) Range due to High Maximum SIF
Authors: Meshii T , Ishihara K , Asakura T
Published: December 2005

In this paper, a method is proposed to quantitatively estimate the decrease in threshold stress intensity factor (SIF) range due to high maximum SIF, that is observed for some materials in constant maximum SIF fatigue crack growth tests. The parameters for the simulation were inversely determined from the experimental data of carbon steel, Al and Ti alloys with the aid of genetic algorithm. The set of candidate parameters named as a “generation” were repeatedly generated and evaluated until the experimental data were reproduced by the simulation. A very interesting fact was that though the test conditions for these three materials were different, the obtained simulation parameters seemed to be independent of material. Finally, the proposed method was validated by comparing predictions with experimentally determined values of the decrease in threshold on an embrittled carbon steel.
Analysis of Creep Crack Initiation and Growth in Different Geometries for 316H and Carbon Manganese Steels
Authors: Davies CM , Mueller F , Nikbin KM , O'Dowd NP , Webster GA
Published: December 2005

Results obtained from a European collaborative project aimed at producing a draft code of practice for creep crack growth testing are presented. The tests were performed on an Austenitic Type 316H Stainless Steel at 550°C and a carbon manganese steel at 400°C. A range of specimen test geometries has been examined. These are the single edge notched specimen in tension and bending, the double edge notched specimen in tension, the middle cracked specimen in tension, and the C-shaped specimen in tension. The results obtained are compared to those obtained using the standard compact tension specimen following the ASTM Standard Test Method for Measurement of Creep Crack Growth Rates in Metals (E 1457). Creep crack creep growth rates and initiation times have been correlated with the fracture mechanics parameter C*. The applicability of the stress intensity factor K to describe the creep cracking behavior is also assessed. Recommendations are made to support the use of different geometries in creep crack growth and/or creep crack initiation testing.
A Novel Method to Evaluate the Influence of Hydrogen on Fatigue Properties of High Strength Steels
Authors: Matsubara Y , Hamada H
Published: December 2005

In rolling contact fatigue, hydrogen is believed to contribute to early flaking failures under some conditions. Hydrogen diffuses quickly in steels, even at room temperature, thus resulting in its dissipation into the surrounding atmosphere. This condition presents a uniquely difficult challenge for evaluating the intrinsic fatigue properties related to hydrogen embrittlement. In order to compensate for this, we employed ultrasonic fatigue testing at a loading frequency of 20 kHz, because a high loading frequency offsets the rapid hydrogen loss. In this report, the fatigue properties of hydrogen pre-charged JIS-SUJ2 (SAE52100 equivalent) were assessed. The amount of hydrogen was quantitatively measured by thermal desorption analysis. The diffusion coefficient of hydrogen was determined via electrochemical hydrogen permeation testing. These results indicate that the magnitude of fatigue strength reduction is directly proportional to the diffusible hydrogen content. Included with this report is our proposed method for evaluating fatigue strength related to hydrogen embrittlement.
Attentional Selection and Action Selection in the Ventral and Orbital Prefrontal Cortex
Authors: Rushworth Matthew F. S. , Buckley Mark J. , Gough Patricia M. , Alexander Iona H. , Kyriazis Diana , McDonald Kathryn R. , Passingham Richard E.
Published: December 2005

Different accounts of the ventral and orbital prefrontal cortex (PFv+o) have emphasized either its role in learning conditional rules for action selection or the attentional selection of behaviorally relevant stimuli. Although the accounts are not mutually exclusive, it is possible that the involvement of PFv+o in conditional action selection is a consequence of its role in selecting relevant stimuli or that its involvement in attentional selection is a consequence of the conditional rules present in many attentional paradigms. Five macaques learned a conditional action-selection task in which the difficulty of identifying the stimulus relevant for guiding action selection was varied in a simple manner by either altering its distance from the action or presenting additional distracting stimuli. Simply increasing the spatial separation between the instructing stimulus led to slower responses. Experiment 1 showed that bilateral PFv+o lesions impaired conditional action selection even when attentional demands were kept to a minimum, but there was evidence that the impairment was exacerbated by manipulating stimulus selection difficulty. Experiment 2 confirmed the importance of PFv+o for conditional action selection even when stimulus selection difficulty was minimal. Experiments 3 and 4 demonstrated that the action-selection impairment was significantly increased by making identification of the behaviorally relevant stimulus difficult. PFv+o is central to the use of conditional rules when selecting courses of action, but conditional rules are also represented in premotor and striatal regions. A special contribution of PFv+o may be initial selection of behaviorally relevant stimuli.
Early and Late Mechanisms of Surround Suppression in Striate Cortex of Macaque
Authors: Webb Ben S. , Dhruv Neel T. , Solomon Samuel G. , Tailby Chris , Lennie Peter
Published: December 2005

The response of a neuron in striate cortex to an optimally configured visual stimulus is generally reduced when the stimulus is enlarged to encroach on a suppressive region that surrounds its classical receptive field (CRF). To characterize the mechanism that gives rise to this suppression, we measured its spatiotemporal tuning, its susceptibility to contrast adaptation, and its capacity for interocular transfer. Responses to an optimally configured grating confined to the CRF were strongly suppressed by annular surrounding gratings drifting at a wide range of temporal and spatial frequencies (including spatially uniform fields) that extended from well below to well above the range that drives most cortical neurons. Suppression from gratings capable of driving cortical CRFs was profoundly reduced by contrast adaptation and showed substantial interocular transfer. Suppression from stimuli that lay outside the spatiotemporal passband of most cortical CRFs was relatively stronger when the stimulus on the CRF was of low contrast, was generally insusceptible to contrast adaptation, and showed little interocular transfer. Our findings point to the existence of two mechanisms of surround suppression: one that is prominent when high-contrast stimuli drive the CRF, is orientation selective, has relatively sharp spatiotemporal tuning, is binocularly driven, and can be substantially desensitized by adaptation; the other is relatively more prominent when low-contrast stimuli drive the CRF, has very broad spatiotemporal tuning, is monocularly driven, and is insusceptible to adaptation. Its character suggests an origin in the input layers of primary visual cortex, or earlier.
Specificity in the Projections of Prefrontal and Insular Cortex to Ventral Striatopallidum and the Extended Amygdala
Authors: Reynolds Sheila M. , Zahm Daniel S.
Published: December 2005

The basal forebrain functional-anatomical macrosystems, ventral striatopallidum, and extended amygdala are innervated by substantially coextensive distributions of neurons in the prefrontal and insular cortex. This suggests two alternative organizational schemes: convergent, in which a given cortical area projects exclusively to only one of these macrosystems and divergent, in which a given cortical area innervates both forebrain macrosystems. To examine the underlying organization and possibly discriminate between these alternatives, rats were injected with two retrograde tracers in different parts of ventral striatopallidum or extended amygdala (homotypic injection pairs) or with one tracer in each macrosystem (heterotypic). The prefrontal and insular cortex was evaluated microscopically for overlap of retrograde labeling and double labeling of neurons. Homotypic injection pairs in the ventral striatum and extended amygdala produced extensive overlap of retrogradely labeled neurons and significant double labeling, suggesting that cortical projections spread broadly within macrosystems. In contrast, heterotypic injection pairs produced significant overlap of retrograde labeling but negligible double labeling, indicating that ventral striatopallidum and extended amygdala receive inputs from separate sets of prefronto- and insular cortical neurons. The caudomedial shell of the nucleus accumbens, a supposed “transition” zone between striatopallidum and extended amygdala, had extended amygdala-like afferents but produced few double-labeled neurons and these only when paired with ventral striatopallidum. The data suggest that a modular organization of the basal forebrain, with postulated independent information processing by the ventral striatopallidal and extended amygdala macrosystems, is reflected in a corresponding segregation of output neurons in the prefrontal and insular cortices.
A Genetic Screen for Mutations That Affect Cranial Nerve Development in the Mouse
Authors: Mar Lynn , Rivkin Elena , Kim Dennis Y. , Yu Joanna Y. , Cordes Sabine P.
Published: December 2005

Cranial motor and sensory nerves arise stereotypically in the embryonic hindbrain, act as sensitive indicators of general and region-specific neuronal development, and are directly or indirectly affected in many human disorders, particularly craniofacial syndromes. The molecular genetic hierarchies that regulate cranial nerve development are mostly unknown. Here, we describe the first mouse genetic screen that has used direct immunohistochemical visualization methods to systematically identify genetic loci required for cranial nerve development. After screening 40 pedigrees, we recovered seven new neurodevelopmental mutations. Two mutations model human genetic syndromes. Mutation 7-1 causes facial nerve anomalies and a reduced lower jaw, and is located in a region of conserved synteny with an interval associated with the micrognathia and mental retardation of human cri-du-chat syndrome. Mutation 22-1 is in thePax3gene and, thus, models human Waardenburg syndrome. Three mutations cause global axon guidance deficits: one interferes with initial motor axon extension from the neural tube, another causes overall axon defasciculation, and the third affects general choice point selection. Another two mutations affect the oculomotor nerve specifically. Oculomotor nerve development, which is disrupted by six mutations, appears particularly sensitive to genetic perturbations. Phenotypic comparisons of these mutants identifies a “transition zone” that oculomotor axons enter after initial outgrowth and in which new factors govern additional progress. The number of interesting neurodevelopmental mutants revealed by this small-scale screen underscores the promise of similar focused genetic screens to contribute significantly to our understanding of cranial nerve development and human craniofacial syndromes.