bluuebunny/crossref_metadata_2025 huggingface dataset:
Circulating Tumor Cell Number and Prognosis in Progressive Castration-Resistant Prostate Cancer
Authors: Danila Daniel C. , Heller Glenn , Gignac Gretchen A. , Gonzalez-Espinoza Rita , Anand Aseem , Tanaka Erika , Lilja Hans , Schwartz Lawrence , Larson Steven , Fleisher Martin , Scher Howard I.
Published: December 2007

Purpose: The development of tumor-specific markers to select targeted therapies and to assess clinical outcome remains a significant area of unmet need. We evaluated the association of baseline circulating tumor cell (CTC) number with clinical characteristics and survival in patients with castrate metastatic disease considered for different hormonal and cytotoxic therapies.

Experimental Design: CTC were isolated by immunomagnetic capture from 7.5-mL samples of blood from 120 patients with progressive clinical castrate metastatic disease. We estimated the probability of survival over time by the Kaplan-Meier method. The concordance probability estimate was used to gauge the discriminatory strength of the informative prognostic factors.

Results: Sixty-nine (57%) patients had five or more CTC whereas 30 (25%) had two cells or less. Higher CTC numbers were observed in patients with bone metastases relative to those with soft tissue disease and in patients who had received prior cytotoxic chemotherapy relative to those who had not. CTC counts were modestly correlated to measurements of tumor burden such as prostate-specific antigen and bone scan index, reflecting the percentage of boney skeleton involved with tumor. Baseline CTC number was strongly associated with survival, without a threshold effect, which increased further when baseline prostate-specific antigen and albumin were included.

Conclusions: Baseline CTC was predictive of survival, with no threshold effect. The shedding of cells into the circulation represents an intrinsic property of the tumor, distinct from extent of disease, and provides unique information relative to prognosis.
Phase I Evaluation of CDP791, a PEGylated Di-Fab′ Conjugate that Binds Vascular Endothelial Growth Factor Receptor 2
Authors: Ton N.C. , Parker G.J.M. , Jackson A. , Mullamitha S. , Buonaccorsi G.A. , Roberts C. , Watson Y. , Davies K. , Cheung S. , Hope L. , Power F. , Lawrance J. , Valle J. , Saunders M. , Felix R. , Soranson J.A. , Rolfe L. , Zinkewich-Peotti K. , Jayson G.C.
Published: December 2007

Purpose: Specific blocking of vascular endothelial growth factor receptor 2 (VEGFR-2) is a novel therapeutic approach. Here, we report the first phase I clinical trial evaluation of CDP791, a PEGylated di-Fab′ conjugate that binds VEGFR-2.

Experimental Design: Cohorts of patients received CDP791 at doses between 0.3 and 30 mg/kg every 3 weeks for the initial two doses.

Results: The compound was well tolerated with no dose-limiting toxicity. Dose-related hypertension was observed in patients receiving CDP791 10 mg/kg or more and several patients on the higher doses developed infusion-related cutaneous hemangiomata arising 28 to 106 days after the first drug administration and resolving 3 weeks after cessation. Biopsy and histologic evaluation showed that CDP791-bound VEGFR-2 is non-phosphorylated, suggesting that the drug is biologically active. Concentrations of CDP791 considered biologically relevant were sustained for 3 weeks when doses of 10 mg/kg or more were administered. Although no reductions in vascular permeability were recorded using dynamic contrast enhanced magnetic resonance imaging (DCE-MRI), there was a significant dose level–related reduction in tumor growth. While challenging the recent dogma that active VEGF inhibitors should modulate DCE-MRI measurements of vascular permeability, this highlights the potential of serial three-dimensional tumor measurements to detect tumor growth arrest. Twelve patients received drug for more than two treatments, although no partial or complete responses were seen.

Conclusion: The data show that CDP791 is biologically active and well tolerated, achieving appropriate plasma concentrations when administered at 10 mg/kg or more every 3 weeks.
Anti–Mesothelin Immunotoxin SS1P in Combination with Gemcitabine Results in Increased Activity against Mesothelin-Expressing Tumor Xenografts
Authors: Hassan Raffit , Broaddus V. Courtney , Wilson Shannon , Liewehr David J. , Zhang Jingli
Published: December 2007

Purpose: To determine the antitumor activity of the anti–mesothelin immunotoxin SS1P in combination with gemcitabine against mesothelin-expressing tumor xenografts.

Experimental Design: The in vitro activity of SS1P in combination with gemcitabine against the mesothelin-expressing cell line A431/K5 was evaluated using cytotoxicity and apoptosis assays. The antitumor activity of this combination was evaluated in nude mice bearing A431/K5 tumor xenografts. Tumor-bearing mice were treated with different doses and schedules of gemcitabine alone, SS1P alone (0.2 mg/kg i.v. every other day × three doses), or with both agents together, and tumor volumes were measured over time.

Results: In vitro studies failed to show the synergy of SS1P plus gemcitabine against the mesothelin-expressing A431/K5 cells. In contrast, in the in vivo setting, there was a marked synergy when SS1P was combined with gemcitabine for the treatment of mesothelin-expressing tumor xenografts. This synergy was present using different doses and schedules of gemcitabine administration. In mice treated with fractionated doses of gemcitabine in combination with SS1P, complete tumor regression was observed in all mice and was long-lasting in 60% of the animals. Also, this antitumor activity was specific to SS1P because HA22, an immunotoxin targeting CD22 not expressed on A431/K5 cells, did not increase the efficacy of gemcitabine.

Conclusions: SS1P in combination with gemcitabine results in marked antitumor activity against mesothelin-expressing tumors. This combination could be potentially useful for the treatment of human cancers that express mesothelin and are responsive to gemcitabine therapy.
Unsupervised Acquisition of Predominant Word Senses
Authors: McCarthy Diana , Koeling Rob , Weeds Julie , Carroll John
Published: December 2007

There has been a great deal of recent research into word sense disambiguation, particularly since the inception of the Senseval evaluation exercises. Because a word often has more than one meaning, resolving word sense ambiguity could benefit applications that need some level of semantic interpretation of language input. A major problem is that the accuracy of word sense disambiguation systems is strongly dependent on the quantity of manually sense-tagged data available, and even the best systems, when tagging every word token in a document, perform little better than a simple heuristic that guesses the first, or predominant, sense of a word in all contexts. The success of this heuristic is due to the skewed nature of word sense distributions. Data for the heuristic can come from either dictionaries or a sample of sense-tagged data. However, there is a limited supply of the latter, and the sense distributions and predominant sense of a word can depend on the domain or source of a document. (The first sense of “star” for example would be different in the popular press and scientific journals). In this article, we expand on a previously proposed method for determining the predominant sense of a word automatically from raw text. We look at a number of different data sources and parameterizations of the method, using evaluation results and error analyses to identify where the method performs well and also where it does not. In particular, we find that the method does not work as well for verbs and adverbs as nouns and adjectives, but produces more accurate predominant sense information than the widely used SemCor corpus for nouns with low coverage in that corpus. We further show that the method is able to adapt successfully to domains when using domain specific corpora as input and where the input can either be hand-labeled for domain or automatically classified.
The old authorities in South African practice
Authors: Farlam Ian
Published: December 2007

The old authorities have been quoted in, and relied on by, the courts of the Cape and subsequently in the other territories making up the Republic of South Africa from the foundation of the colony by the Dutch East India Company in the middle of the seventeenth century. By the end of the nineteenth century not only were the main authorities extensively quoted in the courts but the doctrines they contained were being incorporated in the textbooks that were being written. And that is still the position. It is not likely that the new generation of judges to be appointed in the next few decades will frequently consult the old authorities for guidance but the civil component of the law, already anchored in the judgments of the courts and the textbooks, will forever be part of the law. When the old authorities are consulted, it is likely that those used will primarily be those available in English translation.
Gerechtelijke nationale cultuur en haar blinde vlek: de mercuriales en gelegenheidsredes van Charles Faider als procureur-generaal bij het Hof van Cassatie (1871–1885)
Authors: Delbecke Bram
Published: December 2007

This article sketches the attitude of the Belgian liberal magistrate and politician Charles Faider towards the constitutional civil liberties and freedoms. One can discover an interesting paradox by comparing his opening speeches and his acts as a politician. In the speeches he gave as procureur-général at the Cour de cassation, Faider consequently emphasised the beneficiary effects of the liberal 1831 Belgian Constitution. In his discourse, the Belgian magistrates were the best guards of the splendid future of the nation, because they fully understood the age-old national tradition of civil liberties. However, as a politician, he did not hesitate to limit the constitutional rights and liberties. Due to the political pressure of Napoleon III, he limited the freedom of the press by outlawing insulting foreign heads of state. The gap between his discourse and his practice is the perfect expression of an interesting paradox: in the 19th-century Belgian nation state, liberty and national identity profoundly influenced each other, but at the same time restricted their mutual possibilities, because the overall image of a free but responsable nation had to be maintained.
The Construction of Grievance
Authors: Aspinall Edward
Published: December 2007

This article makes a case for extending social constructivist approaches to the study of grievance in natural resource conflicts. It does this by analyzing the separatist conflict in Aceh, Indonesia, which is often portrayed as a paradigmatic resource conflict due to the importance of the natural gas industry there. It is argued here, however, that natural resource exploitation promoted conflict in Aceh only because it became entangled in wider processes of identity construction and was reinterpreted back to the population by ethnic political entrepreneurs in a way that legitimated violence. Rather than any intrinsic qualities of natural resource extraction, the key factor was the presence of an appropriate identity-based collective action frame. The argument is strengthened by comparison with two other resource-rich Indonesian provinces where resource extraction patterns were similar to Aceh but where no protracted violence occurred because similar identity resources were not available to local actors.
Military Famine, Human Rights, and Child Hunger
Authors: Jenkins J. Craig , Scanlan Stephen J. , Peterson Lindsey
Published: December 2007

Discussions of world hunger have focused on economic growth and international food aid, assuming that food supply is the critical issue. The authors show that food access rooted in social stratification and military power is the central problem. Synthesizing the entitlement and military famine approaches to hunger, the authors examine the effects of food supply, economic growth, social stratification, and military power on child hunger in less developed countries (1990-2000) using a cross-national analysis. Child hunger is largely due to gender stratification, militarization, and armed conflict. Halting wars, expanding political rights, and improving gender equity reduce child hunger. Economic growth and programmatic international food aid reduce child hunger, but there are no benefits from increased total food supply or international emergency relief. Child hunger is an access problem best addressed by expanding social and political rights, reducing armed conflict and militarization, and improving women's status. Early warning and relief efforts should focus on these concerns instead of the ``supply'' concerns traditionally emphasized.
African American Divorce in Virginia and Washington, D.C., 1865-1930
Authors: Penningroth Dylan C.
Published: December 2007

This article explores the dynamics of divorce among African Americans from 1865 through the early years of the Great Migration. It builds on recent sociolegal scholarship that sees law as local, experiential, and improvised, drawing on local court records from Virginia and Washington, D.C. By focusing on divorce, a legal proceeding in which the litigants were nearly always of the same race, the article recovers underexamined dimensions of African American life and suggests ways of moving beyond familiar dyads of race relations. Far from avoiding southern lower courts, African Americans pressed hundreds of suits, and participated vigorously in the legal process as litigants, clients, and witnesses. The legal process also involved translating popular notions, including those of gender and race, into legal categories. Black women who ended their marriages had to navigate a treacherous “politics of respectability.” Finally, African American divorce was linked in complex ways to the Great Migration.
Measuring tourist satisfaction by attribute and motivation: The case of a nature-based resort
Authors: Fang Meng  , Tepanon Yodmanee , Uysal Muzaffer
Published: December 2007

Measuring tourist satisfaction plays an important role in marketing tourism products and services. The purpose of this study is to examine the relationship between destination attribute importance and performance, travel motivation, and satisfaction. It is hypothesized that tourist satisfaction of a destination is a function of attribute importance, performance, and travel motivation. A nature-based resort, serving as a short-term family vacation destination in South-east Virginia, was used as the study site for this research. Factor analyses were employed to identify the dimensions of the destination attributes on importance and performance, as well as tourist motivations. The composite delineated factors were used as indicators to measure the overall tourist satisfaction in the regression analysis. The results revealed that friendly/quality services and lodging performance are significant factors in determining the overall satisfaction, whereas food and location are of significant importance in the satisfaction evaluation. Travel motivation, `family/friend togetherness' in particular, although not a statistical significant factor, practically explains its influence on the overall tourist satisfaction of a resort destination.
Understanding the use of celebrity endorsers for hospitality firms
Authors: Magnini Vincent P. , Honeycutt Earl D. , Cross Ashley M.
Published: December 2007

Promotional clutter makes it extremely difficult for hospitality firms to capture the attention of prospective buyers with sales messages. One way firms attempt to penetrate clutter is by utilizing an effective celebrity endorser. When the proper celebrity endorser is selected to represent a firm, sales and brand image can be significantly bolstered. Conversely, selecting an inappropriate celebrity endorser severely reduces sales and brand reputation. This research study collected data from a convenience sample of 213 adults in the USA and found that trustworthiness, expertise, and genuine support are important characteristics for an effective celebrity endorser to possess. Further, the findings confirm that a match between the celebrity's and company's image and values and the celebrity being perceived by the buyer as part of his/her reference group are also statistically significant characteristics of an effective endorser.
Profiling four wheel drive tourism markets for desert Australia
Authors: Taylor Andrew , Prideaux Bruce
Published: December 2007

Sales of four wheel drive (4WD) recreational vehicles in Australia continue to grow at a faster rate than for other vehicle types. Meanwhile anecdotal reporting suggests there is a growing demand for 4WD tourism experiences to Australia's desert areas. To date there has been no segmentation of 4WD tourism markets and this has encouraged destination marketing organizations and product developers in desert areas to adopt a broad-brushed approach for attracting visitors. In this article we present findings from focus groups and surveys of 4WD enthusiasts conducted at large 4WD shows to propose a segmentation of the market. The findings emphasize that the market is not homogeneous. For desert areas, the Explorer-traveller segment expresses a high favourability for trips there; however, other segments are important. Those directly and indirectly involved in 4WD tourism should benefit from applying this understanding to develop products and experiences which reflect the motivations and experiential aspirations of their target segments.
Using Saccharomyces cerevisiae to Test the Mutagenicity of Household Compounds: An Open Ended Hypothesis-Driven Teaching Lab
Authors: Marshall Pamela A.
Published: December 2007

In our Fundamentals of Genetics lab, students perform a wide variety of labs to reinforce and extend the topics covered in lecture. I developed an active-learning lab to augment the lecture topic of mutagenesis. In this lab exercise, students determine if a compound they bring from home is a mutagen. Students are required to read extensive background material, perform research to find a potential mutagen to test, develop a hypothesis, and bring to the lab their own suspected mutagen. This lab uses a specially developed strain of Saccharomyces cerevisiae, D7, to determine if a compound is a mutagen. Mutagenesis of the D7 genome can lead to a scorable alteration in the phenotypes of this strain. Students outline and carry out a protocol for treatment of the yeast tester strain, utilizing the concept of dose/response and positive and negative controls. Students report on their results using a PowerPoint presentation to simulate giving a scientific presentation. The students' self-assessment of their knowledge indicated that, in all cases, the students felt that they knew more about the assay, mutagenesis, and the relationship between genotype and phenotype (P < 0.05) after completing the exercise.
Undergraduate Research Experiences Support Science Career Decisions and Active Learning
Authors: Lopatto David
Published: December 2007

The present study examined the reliability of student evaluations of summer undergraduate research experiences using the SURE (Survey of Undergraduate Research Experiences) and a follow-up survey disseminated 9 mo later. The survey further examines the hypothesis that undergraduate research enhances the educational experience of science undergraduates, attracts and retains talented students to careers in science, and acts as a pathway for minority students into science careers. Undergraduates participated in an online survey on the benefits of undergraduate research experiences. Participants indicated gains on 20 potential benefits and reported on career plans. Most of the participants began or continued to plan for postgraduate education in the sciences. A small group of students who discontinued their plans for postgraduate science education reported significantly lower gains than continuing students. Women and men reported similar levels of benefits and similar patterns of career plans. Undergraduate researchers from underrepresented groups reported higher learning gains than comparison students. The results replicated previously reported data from this survey. The follow-up survey indicated that students reported gains in independence, intrinsic motivation to learn, and active participation in courses taken after the summer undergraduate research experience.
Business Change Process, Creativity and the Brain
Authors: YEATS ROWENA M. , YEATS MARTYN F.
Published: December 2007

Abstract:  Resolution of a critical organizational problem requires the use of carefully selected techniques. This is the work of a management consultant: facilitating a business change process in an organizational setting. Here, an account is provided of a practitioner's reflections on one such case study that demonstrates a structure for a business change process. The reflective account highlights certain affective states and social behaviors that were extracted from participants during the business change process. These affective states and social behaviors are mediated by specific neural networks in the brain that are activated during organizational intervention.
By breaking down the process into the affective states and social behaviors highlighted, cognitive neuroscience can be a useful tool for investigating the neural substrates of such intervention. By applying a cognitive neuroscience approach to examine organizational change, it is possible to converge on a greater understanding of the neural substrates of everyday social behavior.
Being Fed Up
Authors: MOJZISCH ANDREAS , SCHULZ‐HARDT STEFAN
Published: December 2007

Abstract:  Being fed up with something is a prevalent and fundamental human experience. Although the relevance of mental satiation, that is, the process of becoming fed up with an action, is highly acknowledged in organizational psychology, almost no empirical research has examined this concept. In this article, we take a social cognitive neuroscience approach to mental satiation. By building on and extending the classic work of Lewin and Karsten, we propose a new model of mental satiation that focuses on the cognitive, motivational, and neural processes underlying mental satiation. Our model starts with the assumption that repeated performance of an action undermines one's need for competence and hence leads to a loss of intrinsic motivation. We then distinguish between two phases of the satiation process: The first phase is characterized by a loss of intrinsic motivation to perform the action. The second phase starts when the intrinsic motivation has vanished and volitional control is required to continue the action. We predict that the loss of intrinsic motivation in the first phase of the satiation process is correlated with a decrease in activity in brain regions associated with positive hedonic experience, such as the nucleus accumbens, the ventral pallidum, and the medial orbitofrontal cortex. In contrast, the growing aversion toward the action during the second phase of the satiation process is predicted to be correlated with an increase in activity in brain regions associated with unpleasant affect and volitional control, such as the amygdala, the anterior insula, and the anterior cingulate cortex.
Hormonal and Genetic Influences on Processing Reward and Social Information
Authors: CALDÚ XAVIER , DREHER JEAN‐CLAUDE
Published: December 2007

Abstract: Social neuroscience is an emerging interdisciplinary field that combines tools from cognitive, cellular, and molecular neuroscience to understand the neural mechanisms underlying human interactions, emphasizing the complementary nature of different organization levels in the social and biological domains. Previous studies focused on the molecular/neuronal substrates of a variety of complex behaviors, such as parental behavior and pair bonding. Less is known about the various factors influencing interindividual differences in reward processing and decision making in social contexts, both relying upon the dopaminergic system. This review concerns (1) basic electrophysiological findings and recent neuroimaging findings showing that reward processing and social interaction processes share common neural substrates and (2) genetic and hormonal influences on these processes. Recent research combining molecular genetics, endocrinology, and neuroimaging demonstrated that variations in dopamine‐related genes and in hormone levels affect the physiological properties of the dopaminergic system in nonhuman primates and modulate the processing of reward and social information in humans. These findings are important because they indicate the neural influence of genes conferring vulnerability to develop neuropathologies such as drug addiction and pathological gambling. Taken together, the reviewed data start to unveil the relationships between genes, hormones, and the functioning of the reward system, as well as decision making in social contexts, and provide a link between molecular, cellular, and social cognitive levels in humans.
Neural Correlates of Corporate Camaraderie and Teamwork
Authors: LEVINE CATHERINE
Published: December 2007

Abstract: Corporate citizenship creates an ethical and professional accountability among the employee, the organization, and the outside market. Teamwork is an essential part of this corporate accountability because it increases communication and confidence within the organization and promotes camaraderie and goal completion. Cognitive neuroscience research has been able to localize socialization to various areas of the limbic system, which includes, among other structures, the hypothalamus and amygdala, and is associated with the prefrontal cortex. These neurocortical areas can be monitored while set tasks are performed experimentally or observed naturally. Within the framework of cognitive neuroscience, one can evaluate the neural architecture involved in various states of organizational behavior. One can then use this framework as an overlay in the corporate environment to track project completion and profitability.
Research Possibilities for Organizational Cognitive Neuroscience
Authors: BUTLER MICHAEL J.R. , SENIOR CARL
Published: December 2007

Abstract:  In this article, we identify research possibilities for organizational cognitive neuroscience that emerge from the papers in this special issue. We emphasize the intriguing finding that the papers share a common theme—the use of cognitive neuroscience to investigate the role of emotions in organizational behavior; this suggests a research agenda in its own right. We conclude the article by stressing that there is much yet to discover about how the mind works, especially in organizational settings.
God and Country: An Introduction
Authors: Castelli Elizabeth A.
Published: December 2007

elizabeth a. castelli is Professor of Religion at Barnard College at Columbia University. She is the author, most recently, of Martyrdom and Memory: Early Christian Culture Making (Columbia University Press, 2004), and the editor of the journal, Postscripts: The Journal of Sacred Texts and Contemporary Worlds, published by Equinox (uk).
Sex, Law, and Other Reasonable Endeavors
Authors: Skerrett Kathleen Roberts
Published: December 2007

kathleen roberts skerrett is Associate Professor of Religious Studies at Grinnell College.
Contact stresses in conical rollers
Authors: Ali M , Shakoor M , Flugrad D , Qamhiyah A
Published: December 2007

In this paper, the pure rolling contact stresses in conical rollers under normal loading are studied. The existing analytical expression for pure rolling contact pressure in uniform cross-section cylinders is modified to determine the contact area, the contact pressure, and its distribution in conical rollers under normal loading. The Hertzian contact stresses are determined for the modified pure rolling contact pressure distribution. The theoretical results are compared with the finite element analysis using ABAQUS, for different vertex angles, materials, and loads. The results of the theoretical model are found to be consistent with the finite element simulations in predicting the contact pressure, the distribution, and the contact stresses in conical rollers.
Bending of uniformly loaded circular plates supported by a tapered cross stiffener
Authors: Kimura K , Okamoto M , Uemura K
Published: December 2007

In the present paper, the problems of the bending of a uniformly loaded circular plate are treated, which is supported by a crossed and tapered beam grid formed of two beams intersecting at the centre of the plate at right angles. In the case where the beam stiffeners are not welded to the circular plate, gaps between the plate and the beams may partially open according to the beam taper and support conditions of the plate and the beams. Thus, a method to find contact parts between the plate and the beams is proposed. Stress and deflection results using the proposed method are presented in dimensionless graphical form for different beam tapers and support conditions of the plate and the beams.
Interfacial parameter analyses for sleeve-pin-shaft connections under axial and torsional cyclic loading using the finite element method
Authors: Jen Y-M , Wei C-L
Published: December 2007

This study investigates the interfacial behaviour of the contact surfaces of the sleeve-pin-shaft connections under axial and torsional cyclic loading. Fatigue experiments for the connections have been performed in a previous study using a biaxial material testing system. The fretting fatigue cracks initiated at the pin-hole edge of the shafts were found to be the main cause of failure of the connections. In this work, the fretting wear parameters and cyclic stress/strain behaviour of the contact surfaces of the components are simulated using the elastic-plastic finite element method. Several representative interfacial parameters, such as contact pressure, slip displacement, and tangential stress along the pin-hole edge of the shaft are considered herein. The effect of the coefficient of friction between the contact surfaces on the stress/strain behaviour on the pin-hole edge is also investigated. These simulated results can be applied in the future to elucidate the complicated failure mechanism that results from interaction between the plain fatigue and fretting fatigue behaviours of the contact surfaces.
Analytical model development for the prediction of the frictional resistance of a capsule endoscope inside an intestine
Authors: Kim J-S , Sung I-H , Kim Y-T , Kim D-E , Jang Y-H
Published: December 2007

For the purpose of optimizing the design of the locomotion mechanism as well as the body shape of a self-propelled capsule endoscope, an analytical model for the prediction of frictional resistance of the capsule moving inside the small intestine was first developed. The model was developed by considering the contact geometry and viscoelasticity of the intestine, based on the experimental investigations on the material properties of the intestine and the friction of the capsule inside the small intestine. In order to verify the model and to investigate the distributions of various stress components applied to the capsule, finite element (FE) analyses were carried out. The comparison of the frictional resistance between the predicted and the experimental values suggested that the proposed model could predict the frictional force of the capsule with reasonable accuracy. Also, the FE analysis results of various stress components revealed the stress relaxation of the intestine and explained that such stress relaxation characteristics of the intestine resulted in lower frictional force as the speed of the capsule decreased. These results suggested that the frontal shape of the capsule was critical to the design of the capsule with desired frictional performance. It was shown that the proposed model can provide quantitative estimation of the frictional resistance of the capsule under various moving conditions inside the intestine. The model is expected to be useful in the design optimization of the capsule locomotion inside the intestine.
A dynamic model of simulating stress distribution in the distal femur after total knee replacement
Authors: Shi J F , Wang C J , Laoui T , Hart W , Hall R
Published: December 2007

The aim of this study has been to develop a dynamic model of the knee joint after total knee replacement (TKR) to analyse the stress distribution in the distal femur during daily activities. Using MSC/ADAMS and MSC/MARC software, a dynamic model of an implanted knee joint has been developed. This model consists of the components of the knee prosthesis as well as the bones and ligaments of the knee. The femur, tibia, fibula, and patella have been modelled as mixed cortico-cancellous bone. The distal part of femur has been modelled as a flexible body with springs used to simulate the ligaments positioned at their anatomical insertion points.

With this dynamic model a gait cycle was simulated. Stress shielding was identified in the distal femur after TKR, which is consistent with other investigators' results. Interestingly, higher stresses were found in the bone adjacent to the femoral component peg.

This dynamic model can now be used to analyse the stress distribution in the distal femur with different load conditions. This will help to improve implant designs and will allow comparison of prostheses from different manufacturers.
Quantification of the coupled motion that occurs with axial rotation and lateral bending of the head-neck complex: An experimental examination
Authors: Senouci M , FitzPatrick D , Quinlan J F , Mullett H , Coffey L , McCormack D
Published: December 2007

The vertebrae of the cervical spine exhibit out-of-plane or coupled motion during axial rotation and lateral bending. Quantifying the range of motion (ROM) of this occurrence can aid the understanding of cervical spine injury mechanisms and disorders, as well as the development of new treatment methods. Previous studies have formulated ratios to describe coupled motion obtained from in-vitro examinations. The aim of the present study was to use in-vivo test data to develop mathematical relationships to quantify the coupled motion that occurs with axial rotation and lateral bending of the head-neck complex. Using a three-dimensional motion analyser it was possible to trace the coupling effect throughout the full range of unrestricted head-neck motion. Values for primary and coupled ROMs were obtained, showing no significant difference between male and female primary ROMs but a small disparity between male and female coupled ROMs. Regression equations were found to quantify coupled motion throughout the range of axial rotation and lateral bending.

The present experimental study also examines the range of horizontally fixed axial rotation of the head to determine the minimum amount of coupled lateral bending that takes place, which has not been measured previously.
Can cobalt levels estimate in-vivo wear of metal-on-metal bearings used in hip arthroplasty?
Authors: Khan M , Kuiper J H , Richardson J B
Published: December 2007

High levels of cobalt and chromium ions are detected in the blood and urine of patients with metal-on-metal (MoM) hip replacement. These elements are released as a result of wear at the bearing surfaces. Wear rates depend on a multitude of factors, which include the bearing geometry, carbon content, manufacturing processes, lubrication, speed and direction of sliding of the surfaces, pattern of loading, and orientation of the components. In-vivo wear of MoM bearings cannot be reliably measured on X-rays because no distinction can be made between the bearing surfaces. Hip simulator studies have shown that wear rates are higher during the initial bedding-in phase and subsequently drop to very low levels. Accordingly, metal ion levels would be expected to decrease with the use of the bearing, measured as implantation time following surgery. However, several clinical studies have found that metal ion levels either gradually rise or fluctuate instead of decreasing to lower levels. Moreover, hip simulator studies predict that large-diameter bearings have lower wear rates than small-diameter bearings. In clinical studies, however, metal levels in patients with large-diameter bearings are unexpectedly higher than those in patients with small-diameter bearings.

As a consequence, high cobalt ion levels in patients do not necessarily imply that their MoM bearings produce much wear debris at the time that their levels were measured; it may simply be due to accumulation of wear debris from the preceding time. Exercise-related cobalt rise may overcome this limitation and give a better assessment of the current wear status of a MoM bearing surface than a measure of cobalt levels only.
Increasing patients' body mass. Are the criteria for testing stemmed femoral components in total hip arthroplasty still valid?
Authors: Wroblewski B M , Siney P D , Fleming P A
Published: December 2007

The increasing incidence of obesity in the population is a topic of current interest. This trend is reflected in patients undergoing primary Charnley hip replacement. Over a 21 year period from January 1986 to October 2006, during which 6910 primary operations were performed, the body mass of patients increased at a mean rate of 0.48 kg/year. The findings suggest that the test criteria for the endurance of stemmed femoral components be modified. The maximum load should be increased from 2.3 kN to 2.5 kN to reflect patients' increasing weight. The duration of the test should be increased from 5 × 106 cycles during which the ‘femoral component shall not fracture’ to 10 × 106 cycles in order to reflect not only the patients' activity level but also the 4-11 year period at risk for stem fracture, and so ‘reflect developing clinical experience’.
Model predictive control for non-linear missiles
Authors: Hu X. B. , Chen W. H.
Published: December 2007

The present paper reports an attempt of applying model predictive control (MPC) to design an autopilot for a non-linear missile. The non-linear, fast dynamics of the missile raise three issues in the design of an MPC algorithm: the choice of the MPC performance index, in particular the terminal weighting term, to compromise the performance and the stability requirements; loss of the global minimum in the online optimization since it is a nonlinear optimization; and the computational time limitation imposed by the fast sampling requirement. For the first issue, a procedure is developed to determine the terminal weighting term using a new representation of the control sequence in the moving horizon. For the other two issues, a new initial control profile and an associated control strategy are adopted in each optimization routine. It is shown that the new MPC algorithm can guarantee stability, even when a local minimum is attained in the online optimization or the optimization process has to stop owing to the limitation of the sampling time. Simulation results carried on the missile show that good performance and stability are achieved by the new MPC algorithm, whereas four other current MPC algorithms lose their stability.
A new approach for modelling and identification of the pneumatic artificial muscle manipulator based on recurrent neural networks
Authors: Ahn K. K. , Anh H. P. H.
Published: December 2007

Pneumatic artificial muscles (PAMs) are widely used in the various fields of medical robots and other industrial applications. As a powerful tool of intelligent control, neural networks nowadays are applied effectively to model, identify, and control highly non-linear systems, including the PAM manipulator. In the current paper a prototype PAM manipulator is modelled through recurrent neural networks (NN) modelling and identification based on experimental input-output training data. The proposed incremental back-propagation (INCBP) algorithm, which yields faster convergence than a conventional back-propagation (BP) algorithm, is applied to train the neural networks. The realization of the INCBP algorithm is given. An evaluation is carried out for different non-linear NN auto-regressive with exogenous input (NNARX) models of a PAM manipulator, using recurrent NN with various input nodes as well as various hidden layer nodes. For the first time, the non-linear NNARX model scheme of the prototype PAM manipulator has been investigated. The results show that the non-linear NNARX model trained by INCBP yields better performance and higher accuracy than the traditional linear ARX model. These results can be applied in modelling, identifying, and controlling not only the PAM manipulator, but also other highly non-linear systems.
A delay-range-dependent approach to global robust stability for discrete-time uncertain recurrent neural networks with interval time-varying delay
Authors: Lu C. Y.
Published: December 2007

The current paper performs a global robust stability analysis for a class of discrete-time recurrent neural networks (DRNNs) with norm-bounded time-varying parameter uncertainties and interval time-varying delay. The activation functions are assumed to be globally Lipschitz continuous. An appropriate type of Lyapunov functional is proposed to establish the sufficient conditions for the DRNNs. The criteria are formulated by means of the feasibility of linear matrix inequalities (LMIs), which can be easily checked in practice. Two numerical examples are given to illustrate the effectiveness and applicability.
Low-emission combustion of a pre-chamber-type compression ignition natural gas engine
Authors: Sasaki H , Sekiyama S , Hashimoto M , Nakashima K
Published: December 2007

A pre-chamber-type compression ignition natural gas engine was constructed and its performance and NO emissions were investigated. The pre- and main chambers made of ceramics were connected by a throat valve that opened during the compression stroke. An homogenous fuel air charge mixed with exhaust gas recirculation (EGR) gases was introduced into the main chamber, while a smaller amount of fuel was supplied into the pre-chamber during the intake stroke. The mixture in the pre-chamber was auto-ignited when the compressed hot gases in the main chamber were introduced into the pre-chamber through the throat valve during the compression stroke. The engine was operated without knock under various load conditions by adjusting the throat valve opening timing appropriately. The influences of the throat valve opening timing, compression ratio, and pre-chamber volume ratio on torque and NO emissions were investigated. Test results showed that: (a) at conditions when the thermal efficiencies were high, the patterns of the rate of heat release were similar to each other and independent of the compression ratio and pre-chamber volume ratio; (b) the optimum throat valve opening timing was strongly dependent on compression ratio and pre-chamber volume ratio; and (c) at conditions when the rate of heat release displayed two peaks - first low peak corresponding to the initial combustion in the pre-chamber and second high peak corresponding to combustion in the main chamber - low NO emissions below 20 ppm featuring homogeneous charge compression ignition (HCCI) combustion were achieved.
Dynamic behaviour and stability of marine propulsion systems
Authors: Figari M , Altosole M
Published: December 2007

The paper describes an approach used to study the dynamic behaviour of marine propulsion systems. The method consists of three main steps: analytical modelling of the ship propulsion system, stability analysis of the system, and dynamic behaviour of the propulsion plant. The model is based on non-linear first-order differential equations. The concepts of ‘geometric non-linear dynamics’ are used to highlight some important properties of the model. One of the main advantages of the method is that it enables some important dynamic properties of the propulsion system to be highlighted without solving the differential equations of motion. In particular circumstances an analytical solution of the proposed model is possible; the solution includes the steady state behaviour of the system, which is useful for the engine-propulsion matching.
A multi-sensor data fusion navigation system for an unmanned surface vehicle
Authors: Xu T , Sutton R , Sharma S
Published: December 2007

Worldwide there is an increasing interest in the development of unmanned surface vehicles (USVs). In order for such vehicles to undertake missions, they require accurate, robust, and reliable navigation systems. This paper describes the implementation of a fault tolerant autonomous navigation approach for a USV named Springer. An intelligent multi-sensor data fusion navigation algorithm is proposed that is based on a modified form of a federated Kalman filter (FKF) utilizing a fuzzy logic adaptive technique. The fuzzy adaptive technique is used to adjust the measurement noise covariance matrix R to fit the actual statistics of the noise profile present in the incoming sensor measured data using a covariance matching method. Information feedback factors employed in the FKF are tuned on the basis of the accuracy of each sensor. In order to compare the fault-tolerant performance, several fuzzy-logic-based cascaded Kalman filter architectures are also considered. Simulation results demonstrate the algorithm's capability under different types of sensor fault.
Dynamic stability of the air-lifted catamaran
Authors: Vassalos D , Xie N , Jasionowski A , Lee B S
Published: December 2007

The air-lifted catamaran (ALC) is an innovative fast marine transportation concept, comprising the application and variation of a new, skirtless air cushion and air lubrication, thus rendering it a hybrid of a catamaran and an SES (surface effect ship). Its features and capabilities are beyond those of current, conventional high-speed monohulls and catamarans. The present paper presents pertinent studies on stability concerning this craft, including dynamic stability, stability in turning, and directional stability. The stability analysis takes into account air compressibility in the cushion, and is carried out in the time domain. Some simulated results are presented and discussed, and requirements for design and operation of the craft, based on IMO HSC Code 2000, are briefly outlined.
A Facile KF/Al2O3-mediated, One-pot Synthesis of Symmetrical Trithiocarbonates from Alkyl Halides and Carbon Disulfide
Authors: Movassagh Barahman , Soleiman-Beigi Mohammad , Nazari Mohammad
Published: December 2007

A facile, efficient, and convenient method has been developed for the one-pot synthesis of symmetrical trithiocarbonates from carbon disulfide and various alkyl halides in the presence of KF/Al2O3 in DMF at room temperature.
Observation of Arsenic Transfer in Leaf Tissue of Hyperaccumulator Fern by Utilizing Synchrotron Radiation Micro-XRF Imaging
Authors: Kitajima Nobuyuki , Kashiwabara Teruhiko , Fukuda Naoki , Endo Satoshi , Hokura Akiko , Terada Yasuko , Nakai Izumi
Published: December 2007

We have directly observed the early process of arsenic transfer in the leaf tissue of hyperaccumulator fern (Pteris vittata L.) within 12 h after the arsenic feeding, by utilizing a synchrotron radiation micro-XRF imaging. This study visually revealed for the first time that arsenic transferred from the root to the marginal part of the leaf within 1 h after feeding. Arsenic accumulated in the region of the vascular bundle and transferred to the paraphysis prior to the sporangium.
Solvo-thermal Preparation of Cadmium Telluride Nanoparticles from a Novel Single Source Molecular Precursor
Authors: Selvakumar D , Tripathi Santosh Kumar , Singh Rajendra , Nasim M
Published: December 2007

A convenient solvo-thermal route has been developed for the preparation of cadmium telluride nanoparticles using a novel single source molecular precursor. The X-ray diffraction pattern confirms the face-centered-cubic structure and average diameter of the nanocrystallite is calculated to be 29.5 nm. SEM image clearly shows the needle-like structure which is further supported by TEM image where agglomerated nanoparticles are clearly seen.