bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-term implant—bone fixation of the femoral component in total knee replacement
Authors: Cristofolini L , Affatato S , Erani P , Leardini W , Tigani D , Viceconti M
Published: April 2008

Success of total knee replacement (TKR) depends on the prosthetic design. Aseptic loosening of the femoral component is a significant failure mode that has received little attention. Despite the clinical relevance of failures, no protocol is available to test long-term implant—bone fixation of TKR in vitro. The scope of this work was to develop and validate a protocol to assess pre-clinically the fixation of TKR femoral components. An in vitro protocol was designed to apply a simplified but relevant loading profile using a 6-degrees-of-freedom knee simulator for 1 000 000 cycles. Implant—bone inducible micromotions and permanent migrations were measured at three locations throughout the test. After test completion, fatigue damage in the cement was quantified. The developed protocol was successfully applied to a commercial TKR. Additional tests were performed to exclude artefacts due to swelling or creep of the composite femur models. The components migrated distally; they tilted towards valgus in the frontal plane and in extension in the sagittal plane. The migration patterns were consistent with clinical roentgen-stereophotogrammetric recordings with TKR. Additional indicators were proposed that could quantify the tendency to loosen/stabilize. The type and amount of damage found in the cement, as well as the migration patterns, were consistent with clinical experience with the specific TKR investigated. The proposed pre-clinical test yielded repeatable results, which were consistent with the clinical literature. Therefore, its relevance and reliability was proved.
Tribological assessment of a flexible carbon-fibre-reinforced poly(ether—ether—ketone) acetabular cup articulating against an alumina femoral head
Authors: Scholes S C , Inman I A , Unsworth A , Jones E
Published: April 2008

New material combinations have been introduced as the bearing surfaces of hip prostheses in an attempt to prolong their life by overcoming the problems of failure due to wear-particle-induced osteolysis. This will hopefully reduce the need for revision surgery. The study detailed here used a hip simulator to assess the volumetric wear rates of large-diameter carbon-fibre-reinforced pitch-based poly(ether—ether—ketone) (CFR-PEEK) acetabular cups articulating against alumina femoral heads. The joints were tested for 25×106 cycles. Friction tests were also performed on these joints to determine the lubrication regime under which they operate. The average volumetric wear rate of the CFR-PEEK acetabular component of 54 mm diameter was 1.16 mm3/106 cycles, compared with 38.6 mm3/106 cycles for an ultra-high-molecular-weight polyethylene acetabular component of 28 mm diameter worn against a ceramic head. This extremely low wear rate was sustained over 25×106 cycles (the equivalent of up to approximately 25 years in vivo). The frictional studies showed that the joints worked under the mixed—boundary lubrication regime. The low wear produced by these joints showed that this novel joint couple offers low wear rates and therefore may be an alternative material choice for the reduction of osteolysis.
Understanding the differences between the wear of metal-on-metal and ceramic-on-metal total hip replacements
Authors: Figueiredo-Pina C G , Yan Y , Neville A , Fisher J
Published: April 2008

Hip simulator studies have been carried out extensively to understand and test artificial hip implants in vitro as an efficient alternative to obtaining long-term results in vivo. Recent studies have shown that a ceramic-on-metal material combination lowers the wear by up to 100 times in comparison with a typical metal-on-metal design. The reason for this reduction remains unclear and for this reason this study has undertaken simple tribometer tests to understand the fundamental material loss mechanisms in two material combinations: metal-on-metal and ceramic-on-ceramic.

A simple-configuration reciprocating pin-on-plate wear study was performed under open-circuit potential (OCP) and with applied cathodic protection (CP) in a serum solution using two tribological couples: firstly, cobalt—chromium (Co—Cr) pins against Co—Cr plates; secondly, Co—Cr pins against alumina (Al2O3) plates. The pin and plate surfaces prior to and after testing were examined by profilometry and scanning electron microscopy.

The results showed a marked reduction in wear when CP was applied, indicating that total material degradation under the OCP condition was attributed to corrosion processes. The substitution of the Co—Cr pin with an Al2O3 plate also resulted in a dramatic reduction in wear, probably due to the reduction in the corrosion—wear interactions between the tribological pair.
Do Clinicians Always Maximize Patient Outcomes? A Conjoint Analysis of Preferences for Carotid Artery Testing
Authors: Sassi Franco , Mckee Martin
Published: April 2008

Objectives

The value clinicians place on diagnostic information is subject to psychological influences and systematic biases, but there is limited evidence of how these factors may affect patients’ health outcomes. We assessed the relative value attached by experienced clinicians to different diagnostic test characteristics and how their preferences relate to patient outcomes, focusing on strategies for testing symptomatic patients for carotid artery stenosis.

Methods

Using conjoint analysis, experienced neurologists and vascular surgeons ranked 10 diagnostic strategies defined in terms of four characteristics. Clinicians’ preferences were analysed using an ordered probit model and compared with those obtained using a risk neutral expected value (EV) model developed to predict the consequences of each strategy as if the clinicians’ sole goal were to optimize patient outcome. Results were tested for internal consistency and robustness to key model assumptions.

Results

Preferences for positive predictive value (PPV), relative to negative predictive value (NPV), elicited from the clinicians diverged substantially from those estimated by the EV model based on 5-year stroke-free survival (ratios of 20.8 and 232.8, respectively). Conversely, preferences for NPV, relative to test morbidity, from the two models matched closely.

Conclusions

Clinicians attached substantially more importance to the PPV of carotid artery tests than would be justified by ther impact on patient outcomes. Cognitive errors and attitudes to risk are likely to play an important role in explaining this finding. This study casts doubts on the validity of common assumptions made in the evaluation of health interventions, and in clinical and policy decisions.
Modelling the Expected Net Benefits of Interventions to Reduce the Burden of Medication Errors
Authors: Karnon Jonathan , Mcintosh Aileen , Dean Joanne , Bath Peter , Hutchinson Allen , Oakley Jeremy , Thomas Nicky , Pratt Peter , Freeman-Parry Louise , Karsh Ben-Tzion , Gandhi Tejal , Tappenden Paul
Published: April 2008

Objectives

The aim of this study is to estimate the potential costs and benefits of three key interventions (computerized physician order entry [CPOE], additional ward pharmacists and bar coding) to help prioritize research to reduce medication errors.

Methods

A generic model structure was developed to describe the incidence and impacts of medication errors in hospitals. The model follows pathways from medication error points at alternative stages of the medication pathway through to the outcomes of undetected errors. The model was populated from a systematic review of the medication errors literature combined with novel probabilistic calibration methods. Cost ranges were applied to the interventions, the treatment of preventable adverse drug events (pADEs), and the value of the health lost as a result of an ADE.

Results

The model predicts annual health service costs of between £0.3 million and £1 million for the treatment of pADEs in a 400-bed acute hospital in the UK. Including only health service costs, it is uncertain whether any of the three interventions will produce positive net benefits, particularly if high intervention costs are assumed. When the monetary value of lost health is included, all three interventions have a high probability of producing positive net benefits with a mean estimate of around £31.5 million for CPOE over a five-year time horizon.

Conclusions

The results identify the potential cost-effectiveness of interventions aimed at medication errors, as well as identifying key drivers of cost-effectiveness that should be specifically addressed in the design of primary evaluations of medication error interventions.
Patient Choice in General Practice: The Implications of Patient Satisfaction Surveys
Authors: Robertson Ruth , Dixon Anna , Le Grand Julian
Published: April 2008

Objectives

To identify factors that explain patient satisfaction with general practice physicians and hence that may drive patients’ choice of practice.

Methods

Logistic regression analysis of English National Health Service national patient survey data is used to identify the aspects of general practice care that are associated with high levels of overall satisfaction among patients.

Results

Confidence and trust in the doctor is the most important factor in explaining the variation in overall patient satisfaction (predicting 82% of satisfaction levels accurately). The seven variables relating to the relationship between patient and doctor have stronger explanatory power than other aspects of the general practitioner (GP) experience. The variables with the lowest overall predictive power are whether the patient was told how long they would have to wait in the surgery (72%), the length of time they had to wait after their appointment time (74%) and ability to get through to the surgery on the phone (74%).

Conclusions

Patients value the quality of their relationship with their doctor more than the appearance of the surgery, accessibility of appointments and their experience in the waiting room. This suggests that, if current restrictions on choice of GP were removed, we would in theory expect a patient's choice to be driven by the quality of the doctor-patient relationship. Once a patient establishes a good relationship with a GP, however, we might expect them to be loyal and therefore unlikely to change practice unless the relationship with the doctor breaks down. Although relationship factors are important to the satisfaction of patients, it is not clear that they will lead large numbers of people to change their GP.
The Quality of Mixed Methods Studies in Health Services Research
Authors: O'cathain Alicia , Murphy Elizabeth , Nicholl Jon
Published: April 2008

Objectives

To assess the quality of mixed methods studies in health services research (HSR).

Methods

We identified 118 mixed methods studies funded by the Department of Health in England between 1994 and 2004, and obtained proposals and/or final reports for 75. We applied a set of quality questions to both the proposal and report of each study, addressing the success of the study, the mixed methods design, the individual qualitative and quantitative components, the integration between methods and the inferences drawn from completed studies.

Results

Most studies were completed successfully. Researchers mainly ignored the mixed methods design and described only the separate components of a study. There was a lack of justification for, and transparency of, the mixed methods design in both proposals and reports, and this had implications for making judgements about the quality of individual components in the context of the design used. There was also a lack of transparency of the individual methods in terms of clear exposition of data collection and analysis, and this was more a problem for the qualitative than the quantitative component: 42% (19/45) versus 18% (8/45) of proposals (p 5 0.011). Judgements about integration could rarely be made due to the absence of an attempt at integration of data and findings from different components within a study.

Conclusions

The HSR community could improve mixed methods studies by giving more consideration to describing and justifying the design, being transparent about the qualitative component, and attempting to integrate data and findings from the individual components.
Evidence-Based Medicine and Patient Choice: The Case of Heart Failure Care
Authors: Sanders Tom , Harrison1 Stephen , Checkland1 Kath
Published: April 2008

Objectives

The implementation of evidence-based medicine and policies aimed at increasing user involvement in health care decisions are central planks of contemporary English health policy. Yet they are potentially in conflict. Our aim was to explore how clinicians working in the field of heart failure resolve this conflict.

Methods

Qualitative semi-structured interviews were carried out with health professionals who were currently caring for patients with heart failure, and observations were conducted at one dedicated heart failure clinic in northern England.

Results

While clinicians acknowledged that patients’ ideas and preferences should be an important part of treatment decisions, the widespread acceptance of an evidence-based clinical protocol for heart failure among the clinic doctors significantly influenced the content and style of the consultation.

Conclusion

Evidence-based medicine was used to buttress professional authority and seemed to provide an additional barrier to the adoption of patient-centred clinical practice.
How to Write a Good Research Paper
Authors: Light Kate , Glanville Julie , Stirk Lisa
Published: April 2008

There are numerous websites that aim to help students write research papers but it is necessary to look a little further to find websites that are relevant to researchers wishing to publish in peer-reviewed journals. Here we review sites that address scientific writing style, present guidelines for reporting trials and other studies, and provide access to submission requirements for individual journals. Additionally, we list some other relevant sites.

If you would like to alert readers to useful web pages or suggest topics for this column, please send details to:
The Bicriterion Multimodal Assignment Problem: Introduction, Analysis, and Experimental Results
Authors: Pedersen Christian Roed , Nielsen Lars Relund , Andersen Kim Allan
Published: April 2008

We consider the bicriterion multimodal assignment problem, which is a new generalization of the classical linear assignment problem. A two-phase solution method using an effective ranking scheme is presented. The algorithm is valid for generating all nondominated criterion points or an approximation. Extensive computational results are conducted on a large library of test instances to test the performance of the algorithm and to identify hard test instances. Also, test results of the algorithm applied to the bicriterion assignment problem are provided.
A Lifted Linear Programming Branch-and-Bound Algorithm for Mixed-Integer Conic Quadratic Programs
Authors: Vielma Juan Pablo , Ahmed Shabbir , Nemhauser George L.
Published: April 2008

This paper develops a linear-programming-based branch-and-bound algorithm for mixed-integer conic quadratic programs. The algorithm is based on a known higher-dimensional or lifted polyhedral relaxation of conic quadratic constraints. The algorithm is different from other linear-programming-based branch-and-bound algorithms for mixed-integer nonlinear programs in that it is not based on cuts from gradient inequalities and it sometimes branches on integer feasible solutions. The algorithm is tested on a series of portfolio optimization problems. It is shown that it significantly outperforms commercial and open-source solvers based on both linear and nonlinear relaxations.
Assessing the Consequences of a Channel Switch
Authors: Chen Xinlei (Jack) , John George , Narasimhan Om
Published: April 2008

Switching marketing channels is an expensive and sticky decision. While a number of theories suggest efficiency and strategic differences between channels, there is virtually no work on combining these ideas into an empirically workable methodology to assess the impact of a channel switch. In this study, we undertake to close this gap with an empirical study of the sports drink market, featuring competing producers and heterogeneous channels.

We estimate demand and cost parameters for a number of alternative models of competitive interaction and use these estimates to study the switching of Gatorade from its extant (independent wholesaler) channel to the direct store delivery (DSD) channel belonging to Pepsi.

Our initial results indicate the following: Pepsi should switch Gatorade to the DSD channel only if (i) the switch decreases Gatorade's manufacturing cost by at least 14%, or (ii) the switch increases the share of profit it can obtain by at least 13%, or (iii) the switch enhances demand by the equivalent of a price cut of 4.96¢ for a 32-ounces package. Absent these increases, Pepsi should not switch. Our methodology and results speak to both managers contemplating a channel switch and antitrust authorities faced with the task of evaluating the consequences of a change in vertical structure.
Findings—Biased but Efficient: An Investigation of Coordination Facilitated by Asymmetric Dominance
Authors: Amaldoss Wilfred , Bettman James R. , Payne John W.
Published: April 2008

In several marketing contexts, strategic complementarity between the actions of individual players demands that players coordinate their decisions to reach efficient outcomes. Yet coordination failure is a common occurrence. We show that the well-established psychological phenomenon of asymmetric dominance can facilitate coordination in two experiments. Thus, we demonstrate a counterintuitive result: A common bias in individual decision making can help players to coordinate their decisions to obtain efficient outcomes. Further, limited steps of thinking alone cannot account for the observed asymmetric dominance effect. The effect appears to be due to increased psychological attractiveness of the dominating strategy, with our estimates of the incremental attractiveness ranging from 3%–6%. A learning analysis further clarifies that asymmetric dominance and adaptive learning can guide players to an efficient outcome.
Competition and Cooperation in Decentralized Push and Pull Assembly Systems
Authors: Granot Daniel , Yin Shuya
Published: April 2008

In this paper, we study a decentralized assembly system consisting of a single assembler who buys complementary components from independent suppliers under two contracting schemes: push and pull. In both schemes, the component suppliers are allowed to freely form coalitions (or alliances) among themselves to better coordinate their pricing or production decisions. We show that the sole driver of the inefficiency in a push system, which is due to horizontal decentralization of suppliers, is the number of alliances that were formed. Specifically, it is shown that in a push system, the assembler's profit, the total profit of all suppliers and the consumers' surplus are all decreasing in the number of coalitions, and are thus maximized when the grand coalition is formed. We further carry out a stability analysis of coalition structures to verify to what extent suppliers can reduce or eliminate the inefficiency due to their decentralization by forming alliances. We show that in a push system with more than two suppliers and a power demand distribution, myopic suppliers would act independently, resulting with a least efficient channel, which makes all channel members, as well as the end consumers, worse off. On the other hand, we prove that farsighted suppliers would form the grand coalition and thus be able to completely eliminate the inefficiency stemming from their decentralization. Finally, it is shown that, in contrast to a push system, in a pull system the suppliers can easily coordinate their production quantities to eliminate the inefficiency due to their decentralization.
Quantity Discounts Under Demand Uncertainty
Authors: Altintas Nihat , Erhun Feryal , Tayur Sridhar
Published: April 2008

To motivate buyers to increase their order quantity, suppliers often rely on a well-established and widely used approach—they offer quantity discounts. This practice is in large part driven to obtain improved economies in transportation through higher truckload utilization. Recently, transportation rates, which are increasing faster than other costs, have become a larger portion of total net landed cost, placing the traditional quantity-discount practices under scrutiny. Many suppliers are left perplexed as to why their approach is not effective anymore, and some are even concerned that their overall profits may have actually decreased due to their discount parameters. In this paper, we study a multiperiod model, with a buyer facing stochastic end-item demand and a supplier offering an all-units quantity discount to him, to understand better the dynamics of such systems. We provide guidelines and insights on how to set effective discount parameters, and when not to expect much from them. We derive the optimal policy of the buyer, develop insights as to why the policy is complex, study the supplier's profit as a function of her offered quantity-discount scheme (accommodating the buyer's optimal policy), and discover a new phenomenon that is distinct and structurally different from the well-known bullwhip effect.
Constrained Growth: How Experience, Legitimacy, and Age Influence Risk Taking in Organizations
Authors: Desai Vinit M.
Published: April 2008

Poor performance indicates that an organization's routines are not well suited for its environment and prompts decision makers to search for solutions. However, results conflict regarding how this search process influences risk taking in organizations. Managers in some organizations facing actual or expected performance shortfalls tend to take risks, while managers in other poorly performing organizations avoid risky changes. This conflict is interesting because some level of risk taking appears necessary for organizations to remain competitive, adapt to their environment, and improve performance. This study examines several mechanisms that moderate risk taking following performance shortfalls. First, I draw from organizational learning theories to argue that organizations with limited operating experience are less buffered from failure, and hence that poor performance constrains risk taking at these organizations. Second, I argue that organizations with poor legitimacy are also less buffered, and hence that performance shortfalls also lead to risk aversion at these organizations. Third, I draw from structural inertia theory to suggest that older organizations are less able to support risk taking following performance shortfalls. A test of these hypotheses on the capacity expansion behavior of U.S. railroad companies generally supports these hypotheses, although the effect of age is weaker. The findings contribute to theories of organizational learning and to several perspectives in organization theory more broadly.
Emotional Aperture and Strategic Change: The Accurate Recognition of Collective Emotions
Authors: Sanchez-Burks Jeffrey , Huy Quy Nguyen
Published: April 2008

This paper introduces emotional aperture, defined as the ability to recognize the composition of diverse emotions in a collective (e.g., group or business unit). We develop the thesis that a leader's ability to respond effectively to patterns of shared emotions that arise during strategic change and other emotionally turbulent organizational processes depends on the leader's ability to use emotional aperture. Additionally, we describe key cultural, psychological, and contextual enablers and impediments to achieving the necessary focus and accuracy that characterize the effective use of emotional aperture in organizations. This paper provides an initial conceptualization of how individuals can adjust their attention to group-level emotions and thus extends existing notions of emotional competencies (e.g., emotional intelligence) that have focused more narrowly on individual-level emotions.
Ownership Structure and the Relationship Between Financial Slack and R&D Investments: Evidence from Korean Firms
Authors: Kim Hicheon , Kim Heechun , Lee Peggy M.
Published: April 2008

We use agency theory to examine the influence of ownership structure on the relationship between financial slack and R&D investments, highlighting how that relationship might differ depending on the identity of the owners, and their potentially different interests. In doing so, we extend the scope of agency theory by examining the principal-principal conflicts of interests that may exist among different types of owners. Using a sample of Korean manufacturing firms in R&D-intensive industries between 1998 and 2003, we find that financial slack has an inverted U-shaped relationship with R&D investments. Furthermore, that relationship varies depending on the presence of different types of owners. Family ownership positively moderates the relationship between financial slack and R&D investments, whereas domestic institutional investors and foreign investors negatively moderate that relationship. Our results show that distinguishing among different types of owners is instrumental in enhancing our understanding of the nature of the relationship between financial slack and R&D investments.
Allocating Costs in a Collaborative Transportation Procurement Network
Authors: Özener Okan Örsan , Ergun Özlem
Published: April 2008

We study a logistics network in which shippers collaborate and bundle their shipment requests to negotiate better rates with a common carrier. In this setting, shippers can identify collaborative routes with decreased overall empty truck movements. After the optimal routes that minimize total cost of covering all the shippers' demands are determined, this cost is allocated among the shippers. Our goal is to devise cost-allocation mechanisms that ensure the sustainability of the collaboration. We first develop cost-allocation mechanisms with well-known properties from the cooperative game theory literature, such as budget balance, stability, and cross-monotonicity. Next, we define a set of new properties, such as a guaranteed discount from the standalone cost for each shipper, desirable in our setting, and propose several cost-allocation schemes that could lead to implementable solutions. We also perform a computational study on randomly generated and real-life data to derive insights on the performance of the developed allocation schemes.
Intramarket Optimization for Express Package Carriers
Authors: Schenk Luke , Klabjan Diego
Published: April 2008

The flow of packages and documents in collective groups, called splits, of an express package carrier consists of picking up the packages by a courier at customers' locations and bringing them to a station for sorting. Next the splits are transported, either in bulk or containerized conveyances, to a major regional sorting facility called the ramp. In this work we focus on the afternoon and evening operations concerned with stations and the ramp. We deal with the sorting decisions at the stations and the ramp, as well as the transportation decisions among these locations. We model these processes by means of a dynamic program where time periods represent time slices in the afternoon and evening. The resulting myopic problem is a linear mixed-integer program. The overall model is solved by approximate dynamic programming where the value function is approximated by a linear function. Further strategies are developed to speed up the algorithm and decrease the time needed to find feasible solutions. The methodology is tested on several instances from an international express package carrier. Our solutions are substantially better than the current best practice.
Legal Remedies for the Negligent Expert
Authors: Dwyer Déirdre
Published: April 2008

How should the legal system respond when someone who has provided evidence in their capacity as an expert is perceived to have done so negligently? The question is considered in the context of both civil and criminal litigation in England and Wales. The Sally Clark litigation is used here as the main exemplar. Possible remedies are evaluated both as a means of penalising past negligence, and of preventing future negligence.
Disciplinary Uniformity in Uniform—A Success of the Human Rights Act 1998?
Authors: Gale Chris
Published: April 2008

Apart from an awareness of shameful treatment to some shell-shocked soldiers on active duty in the First World War, the subjects of military discipline in general and courts-martial in particular are unlikely to permeate the consciousness of the public at large or, indeed, the vast majority of criminal lawyers. This article explores some of the history of both, the current position in relation to courts-martial and the planned reforms under the Armed Forces Act 2006. That the Human Rights Act 1998 exposed some of the anomalities and worst practices of courts-martial is undeniable. It seems equally likely that the 1998 Act was at least a catalyst for the wholesale review and modernisation of military discipline carried out by the 2006 Act.
Interpretation of Complex Modulus Test Results for Asphalt-Aggregate Mixes
Authors: Levenberg Eyal , Shah Ayesha
Published: April 2008

In this paper, a slightly different approach than usual is suggested to interpret complex modulus results for asphalt-aggregate mixes. Similar to current/common methods, the proposed analysis “forces” the test data to comply with thermo-rheological simplicity and linear viscoelastic (solid) behavior. However, unlike current methods, use is made of both dynamic modulus and phase angle data to obtain a master curve along with the corresponding time-temperature shifting. This is done by assuming a mathematical expression for the relaxation spectrum instead of an equation for the dynamic modulus master curve. Consequently, better compliance with linear viscoelastic theory is a-priori ensured for all subsequent analyses. Moreover, using the proposed method, conversion of the test results from the frequency domain to the time domain arises as a natural and simple outcome of the procedure which does not require sophisticated inversion techniques that are known to be computationally problematic. Complex modulus test results obtained for three different asphalt mixes are presented and analyzed in order to demonstrate the applicability of the proposed method.
Services and Service Composition – An Introduction (Services und Service Komposition – Eine Einführung)
Authors: Dustdar Shahram , Papazoglou Mike P.
Published: April 2008

In this overview paper, we discuss the basic principles underlying service-oriented computing in general, and (Web) services in particular. We discuss the important differences between (Web) services and Web applications and other models in Internet computing. Finally, we discuss where we see the future research challenges in the area of service composition.
Business Process Standards – Current Landscape (Landkarte aktueller Standards zur Beschreibung von Geschäftsprozessen: WS-BPEL, BPEL4People, BPEL-SPE, BPELJ, SCA)
Authors: Kloppmann Matthias , König Dieter , Pfau Gerhard
Published: April 2008

The landscape of current specifications for the description of business processes consists of the Web Services Business Process Execution Language (WS-BPEL) as an adopted standard, and a number of functional extensions allowing for human interactions (BPEL4People), sub-processes with life-cycle coupling (BPEL-SPE), and Java integration (BPELJ). Also relevant for the assembly of portable, executable applications is the Service Component Architecture (SCA) which provides a model for service-based components complementing WS-BPEL. This paper provides an overview of the current business process standards landscape and its further evolution.
Quality of Service in SOA Environments. An Overview and Research Agenda (Quality of Service in SOA-Umgebungen)
Authors: Curbera Francisco , Khalaf Rania , Mukhi Nirmal
Published: April 2008

Interoperability and componentization are the two defining characteristics of Service Oriented Architectures (SOA). From a middleware perspective this means standardized quality of service (QoS) protocols and QoS-rich service descriptions. This paper provides an architectural overview of quality of service issues in SOA environments and a review of open problems and current research directions.
Semantic Execution Environments for Semantics-Enabled SOA (Ausführungsumgebungen für eine um Semantik erweiterte SOA)
Authors: Norton Barry , Pedrinaci Carlos , Domingue John , Zaremba Michal
Published: April 2008

Much recent work in SOA has concentrated on documenting reference architectures. In this paper we present on-going work on the establishment of such an architecture within the OASIS SEE TC, detailing how the benefits of semantic Web services can be applied to SOA and the role of semantic execution environments, such as the IRS and WSMX.
Sequentielle Formelübersetzung (Sequential Formula Translation)
Authors: Samelson Klaus , Bauer Friedrich L.
Published: April 2008

Die Syntax einer Formelsprache wie ALGOL läßt sich als Folge von Zuständen beschreiben, die durch ein Keller genanntes Element angezeigt werden, Die Übergänge werden gesteutert durch zulässige Zustand-Zeichen-Paare, die sich in Form einer Übergangsmatrix darstellen lassen. Diese Beschreibung liefert gleichzeitig eine äußerst einfache Vorschrift zur Übersetzung der Anweisungen der Formelsprache in Maschienprogramme. Lediglich Optimierungsprozesse wie die rekursive Adressenfortschaltung entziehen sich der sequentiellen Behandlung.
Quality of General Movements Is Related to White Matter Pathology in Very Preterm Infants
Authors: Spittle Alicia J. , Brown Nisha C. , Doyle Lex W. , Boyd Roslyn N. , Hunt Rod W. , Bear Merilyn , Inder Terrie E.
Published: April 2008

OBJECTIVE. Preterm infants are at an increased risk for abnormalities of general movements, which predict subsequent poor neurodevelopmental outcome. The cerebral lesion that predisposes the preterm infant to abnormal general movements remains unknown. The objective of this study was to determine the association between MRI-defined cerebral abnormalities and general movements at 1 and 3 months' corrected age in infants who were born very preterm.

METHODS. Eighty-six preterm infants (<30 weeks' gestation) were prospectively recruited and underwent brain MRI at term-equivalent age to investigate the relationship between qualitative white and gray matter pathology and abnormality of general movements. Standardized videotaped recordings of general movements were obtained at 1 and 3 months postterm (±1 week) and scored without knowledge of the MRI findings. At 1 month corrected age, general movements of a writhing character were classified as normal or abnormal (poor repertoire, cramped synchronized, or chaotic). At 3 months' corrected age, fidgety general movements were classified as present or absent.

RESULTS. At 1 month, 53 (62%) infants had abnormal general movements, 46 of whom had poor repertoire general movements and 7 of whom had cramped synchronized general movements. At 3 months, 23 (25%) infants had absent fidgety movements. At both 1 and 3 months of age, consistently abnormal general movement classifications were related to increasing white matter abnormality on MRI. In contrast, there were no significant relationships between general movement classifications and gray matter abnormalities, either individually or in total.

CONCLUSION. The significant relationships between general movements at 1 and 3 months and cerebral white matter abnormalities on MRI in the very preterm infant support the concept that abnormal general movements reflect white matter injury.
Percutaneously Inserted Central Catheter for Total Parenteral Nutrition in Neonates: Complications Rates Related to Upper Versus Lower Extremity Insertion
Authors: Hoang Viet , Sills Jack , Chandler Michelle , Busalani Erin , Clifton-Koeppel Robin , Modanlou Houchang D.
Published: April 2008

OBJECTIVE. The objective of this study was to compare the complication rates of upper versus lower extremity percutaneously inserted central catheters used for total parenteral nutrition in neonates.

METHODS. During a 48-month study period, 396 neonates were identified as having had percutaneously inserted central venous catheters. A total of 370 catheters were inserted from the upper and 107 from the lower extremity. Data retrieved and analyzed were birth weight, gestational age, age at placement, duration in place, duration of total parenteral nutrition, type of infusates, catheter-related bloodstream infection, phlebitis, leakage, occlusion, necrotizing enterocolitis, intraventricular hemorrhage, serum creatinine, liver function tests, and length of hospitalization.

RESULTS. The median birth weight and gestational age were 940 g and 28 weeks. The rate of catheter-related bloodstream infection was 11.6% for the upper and 9.3% in the lower extremity catheters. The most common organism was coagulase-negative Staphylococcus for both upper and lower extremity catheters and significantly higher with catheters from the upper extremity. Lower extremity catheters were in place longer, and the time from insertion to complication was also longer. The rate of cholestasis was higher for the upper extremity catheters. Multiple regression analysis showed that the most significant contributor to cholestasis was duration of time the catheters were in place and the duration of total parenteral nutrition administration. Receiver operating characteristics curve demonstrated higher sensitivity for duration of catheters in predicting cholestasis with duration of total parenteral nutrition being more specific.

CONCLUSION. Lower extremity percutaneously inserted central venous catheters had lower rates of catheter-related bloodstream infection, longer time to first complication, and lower cholestasis despite longer duration of total parenteral nutrition. When possible, lower extremity inserted catheters should be used for the administration of total parenteral nutrition.
Carbon(IV) oxide Capture and Sequestration in Nigeria: Prospects and Challenges
Authors: Isehunwa O. S. , Makinde A. A. , Olamigoke O.
Published: April 2008

The capture and storage of carbon dioxide (CCS) produced during the combustion of fossil fuels now offers one option for attaining large scale reductions in the emissions of greenhouse gases and thus, promote a clean environment. It is now becoming clear that CCS technologies could promote the use or consumption of fossil fuels than otherwise previously thought.

This paper presents an overview of the techniques involved in the capture and sequestration of carbondioxide(CO2). The opportunities and the challenges of the application of CCS in Nigeria are considered.

It is concluded that the development of gas utilization schemes and power plants makes it imperative for Nigeria to give attention to CCS technologies.
A Correlation to Predict the Viscosity of Light Crude Oils
Authors: Isehunwa O. S. , Olamigoke O. , Makinde A. A.
Published: April 2008

Direct viscosity measurements are often expensive or unavailable. Therefore, empirical correlations are often used for predicting the viscosity of crude oils. However, several published correlations are either too simplistic or too complex for routine operational use. Many of the common correlations in use were developed using data from other regions of the world.

Empirical correlations for predicting the viscosity of light crude oils in the Niger Delta have been presented in this paper.

Data from over 400 oil reservoirs from the Niger Delta were collected. The samples were representative of the two crude oil viscosity regimes: above and below the bubble point. After normalquality checks, non-linear multiple regression with linear partial correlation coefficient techniques were used to establish simple correlations between viscosity, pressure, temperature, oil specific gravity and solution gas oil ratio.

Statistical error analysis of the developed correlation showed average absolute relative percentage error of4.00% and 3.25% and R2 of 0.99 and 0.97 for oil viscosity above and below the bubble point respectively. These results constitute considerable improvements over existing correlations.
Safety Aspects of Handling and Using Fecal Material from Urine‐Diversion Toilets—A Field Investigation
Authors: Austin L. M. , Cloete T. E.
Published: April 2008

The most advantageous approach to pathogen destruction in a urine‐diversion toilet vault is to maximize the effects of various environmental factors (i.e., pH, temperature, moisture content, type of bulking agent, and storage time). To quantify these effects, a field experiment was set up, consisting of 6 urine‐diversion toilet vaults, each with a different combination of feces and bulking agent (soil, ash, wood shavings, sodium hydroxide, or straw) and ventilation (ventpipe/no ventpipe). The pH of the mixes varied from 6.37 to 10.09. Temperature probes, which were connected to a data logger, were inserted to the heaps, and the logger monitored over a period of nearly 10 months. Mean heap temperatures ranged from 16.8°C in winter to 27.6°C in summer. In addition, samples were taken at intervals from the various heaps in the vaults and also from an open heap exposed to the elements. The samples were subjected to microbiological testing to quantify the pathogen dieoff over time. In the vaults, there was a 3log 10 (99.9%) reduction of total coliform between 130 and 250 days, fecal coliform between 100 and 250 days, and fecal streptococci from 125 days and longer. In the open heap, these times varied, from 115 days for both total and fecal coliform, to 140 days for fecal streptococci. Viable Ascaris ova were reduced to zero between 44 and 174 days in the vaults and by 44 days in the open heap. The results of this research showed that ventilation of the vault by means of a ventpipe does not result in any meaningful difference in the vault temperature or the rate of pathogen dieoff. While the type of bulking agent used does not significantly affect the temperature of the heap, it does have an effect on the rate of pathogen dieoff. The ordinary soil mix was seen to give the best results, and this was ascribed to the effect of competing microorganisms in the soil itself. It is concluded that, for safety, vaults of urine‐diversion toilets should be sized for a storage period of 9 to 12 months from the last use.
Odorous Volatile Organic Sulfides in Wastewater Treatment Plants in Guangzhou, China
Authors: Sheng Yanqing , Chen Fanzhong , Wang Xinming , Sheng Guoying , Fu Jiamo
Published: April 2008

Odorous volatile organic sulfides (VOSs) in headspace atmosphere and wastewaters were identified and quantified synchronously in two municipal wastewater treatment plants (WWTPs) in Guangzhou, China. Dimethyl sulfide (DMS), with concentrations ranging from 0.66 to 5.41 mg/m 3, was the major VOS in air samples. Carbonyl sulfide (COS), carbon disulfide (CS 2), and dimethyl disulfide (DMDS) ranged from 0.01 to 0.21, 0.03 to 0.44, and 0.06 to 1.61 mg/m 3, respectively. Methanethiol was not found in any gas samples. The concentrations of DMS in wastewaters ranged from 23.68 to 308.17 mg/m 3 and were also the highest values compared with other VOSs, for all of the treatment processes. Methanethiol was detected in all wastewater samples, except that from the aeration tank, which ranged from 113.08 to 216.82 mg/m 3. The COS, carbon disulfide, and DMDS in wastewaters ranged from 0.11 to 2.21, 1.37 to 23.29, and 0.24 to 106.75 mg/m 3, respectively. Odors from pollution related to VOS were different in the two plants, and they were strongly associated with the characteristics of incoming wastewater and treatment processes. The VOSs in ambient air samples from nearby residential areas downwind of the plant border were also measured, and the results strongly suggested that control measures are needed for odor pollution in the WWTPs to mitigate malodor in the surrounding neighborhoods.
Effects of pH and Iron Concentrations on Sulfide Precipitation in Wastewater Collection Systems
Authors: Nielsen Asbjørn Haaning , Hvitved‐Jacobsen Thorkild , Vollertsen Jes
Published: April 2008

Sulfide precipitation by addition of iron salts is a widely used strategy for sulfide control in wastewater collection systems. Several parameters, such as pH, oxidation–reduction conditions, and reactant concentrations, are known to affect the feasibility of the method. However, their combined effects are difficult to predict for complex media, such as wastewater. This study investigates the effect of pH and reactant concentrations on the efficiency of iron sulfide precipitation in anaerobic municipal wastewater. Laboratory experiments showed that, when the pH was below 7, typically less than 40% of the added ferrous iron reacted by sulfide precipitation, although sulfide was in excess. However, when the pH was above 8, almost complete precipitation of all the added ferrous iron was observed. Varying the ferric‐iron‐to‐ferrous‐iron ratio demonstrated that improved efficiency could be achieved when using a 1:1 mixture of ferric chloride and ferrous sulfate.
Cultural Values, Life Experiences, and Wisdom
Authors: Le Thao N.
Published: April 2008

Wisdom is considered one ideal endpoint of human development across cultures. Studies have provided evidence for certain facilitating conditions such as challenging and stressful life events because they increase differentiation through accommodative changes, resulting in greater tolerance for uncertainty, and less projection tendencies and self-centeredness. Positive experiences may also facilitate wisdom by fostering integration and coherence. However, cultural values, particularly conservation and openness, may moderate these experiences for older adults. In a sample of middle-aged to older community dwelling European American adults ( n = 97), results suggested that experiencing a macrosocial event as a negative experience, and spiritual/existential as a positive experience, interacted with conservation value to predict transcendent wisdom. Among Vietnamese American adults ( n = 102), macrosocial event alone was negatively related to transcendent wisdom. These results suggest that not endorsing conservation value as one grows older and experiences different life events is beneficial for wisdom.
Ravishing or Ravaged: Women's Relationships with Women in the Context of Aging and Western Beauty Culture
Authors: Gosselink Carol A. , Cox Deborah L. , McClure Sarissa J. , De Jong Mary L. G.
Published: April 2008

We undertook this narrative analysis study to explore the complexities of women's relationships with other women within the sociocultural milieu of beautyism and ageism. Using an open-ended narrative framework, four focus groups of women living in different regions throughout the U.S. were conducted and analyzed to identify thematic categories within and across group sessions. We discuss four of the six key themes discovered in response to the primary research question: How does beauty culture shape women's experiences of aging and their relationships with women of all ages? We conclude that Western idealized beauty standards exert a divisive impact on women's relationships with each other across the life span, negatively affecting their socioemotional well-being, especially in old age.