bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Extrusion Conditions on Melt Viscoelasticity during Capillary Flow of Low-Density Polyethylene
Authors: Liang J.Z.
Published: December 2008

The melt viscoelastic properties of a low-density polyethylene (LDPE) are measured, at temperatures varying from 140°C to 170°C and in a wide range of extrusion rates by means of a capillary rheometer, to identify the influence of extrusion conditions (such as temperature, die diameter, and flow rate) on the melt viscoelastic behavior. The results show that the entry pressure drop (▵Pen) and the melt extension stress are a quadric function of extrusion rate (V), and it decreases with an increase in die diameter (d). Similarly, the die-swell ratio (B) increases nonlinearly with increasing V and shear stress at the channel wall. The dependence of B on temperature corresponds approximately with the Arrhenius expression. Under these experimental conditions, the ▵Pen and B increase roughly as an exponential function with an increase in the channel contraction ratio.
Spiritual Job Satisfaction in an Iranian Nursing Context
Authors: Ravari Ali , Vanaki Zohreh , Houmann Hydarali , Kazemnejad Anooshirvan
Published: December 2008

This article reports the results of a qualitative study that used a deep interview method. The aim was to gather lived experiences of clinical nurses employed at government-funded medical centres regarding the non-materialistic and spiritual aspects of the profession that have had an important impact on their job satisfaction. On analysing the participants' concepts of spiritual satisfaction, the following themes were extracted: spiritually pleasant feelings, patients as celestial gifts, spiritual commitment, spiritual penchant, spiritual rewards, and spiritual dilemmas. Content analysis of the data indicated that nurses who viewed these dimensions of job satisfaction as a significant factor considered nursing as an opportunity to worship God while providing care for patients, and regarded their aim as achieving patients' contentment by providing nursing care compatible with scientific care methods.
An Overview of Moral Distress and the Paediatric Intensive Care Team
Authors: Austin Wendy , Kelecevic Julija , Goble Erika , Mekechuk Joy
Published: December 2008

A summary of the existing literature related to moral distress (MD) and the paediatric intensive care unit (PICU) reveals a high-tech, high-pressure environment in which effective teamwork can be compromised by MD arising from different situations related to: consent for treatment, futile care, end-of-life decision making, formal decision-making structures, training and experience by discipline, individual values and attitudes, and power and authority issues. Attempts to resolve MD in PICUs have included the use of administrative tools such as shift worksheets, the implementation of continuing education, and encouragement to report. The literature does not yet show these approaches to be effective in the resolution of MD. The need to acknowledge MD among PICU teams is discussed and an argument made that, to facilitate understanding among team members, practice stories need to be shared.
Artificial Neural Network (ANN)-based Crack Identification in Aluminum Plates with Lamb Wave Signals
Authors: Ye Lu  , Lin Ye  , Zhongqing Su  , Limin Zhou  , Li Cheng
Published: December 2008

An inverse analysis based on the artificial neural network technique is introduced for effective identification of crack damage in aluminum plates. The concepts of digital damage fingerprints and damage parameter database, which are prerequisites for neural network developing and training, are presented. Parameterized modeling for finite element analysis and an information mapping approach are applied to constitute the damage parameter database cost-effectively. The generalization performance of the neural network is examined by a process of `leave-one-out' cross-validation and diverse factors are discussed, based on which the optimization of the neural network architecture is evaluated. The capability of this inverse approach is assessed by two crack cases from experiments, with good accuracy obtained in damage parameters (central position, size, and orientation).
Developing Students' Literacy Skills Using High-Tech Speech-Generating Augmentative and Alternative Communication Devices
Authors: Wilkins Julia , Ratajczak Amy
Published: December 2008

This article outlines practical techniques for developing literacy skills in users of high-tech speech-generating augmentative and alternative communication (AAC) devices. The recommended strategies are intended for general classroom teachers who teach literacy skills to students with typical speech. Many students who use high-tech AAC devices participate in grade-level instruction. Strategies based on the National Reading Panel's research-based findings for effective reading instruction are used as guidelines for adapting instruction to incorporate users of AAC. Techniques for teaching phonemic awareness, phonics, vocabulary development, and text comprehension are provided. Because of the emphasis placed on oral reading in developing fluency, this skill area is not directly addressed. Rather, this article provides strategies for developing a skill more directly relevant to AAC users— multimodal meaning making. In using the strategies outlined in this article, classroom teachers will be able to increase the literacy skills of all students with very little adaptation to instruction.
Developing Behavioral Fluency for Students With Autism
Authors: Kubina Richard M. , Yurich Kirsten K.L.
Published: December 2008

With the increase of students with autism in public schools, alternative schools, and in-home programming, attention to effective learning procedures has increased. A general model based on precision teaching for practicing behavior to fluency is presented as a guide for teachers and parents. This model applies to a wide variety of skills and can be tailored for individual students. The procedure for conducting efficient practice fall into four broad categories: (a) planning the practice routine, (b) developing the practice routine, (c) implementing the practice methods, and (d) analysis of data.
The Logarithmic Singularity of a Generally Accelerating Dislocation from the Dynamic Energy—Momentum Tensor
Authors: Luqun Ni  , Markenscoff Xanthippi
Published: December 2008

An accelerating dislocation exhibits a logarithmic singularity in the near field (associated with the acceleration), which had been earlier derived from the full solution. Here, the existence and evaluation of the logarithmic singularity are obtained solely from the leading terms (1/ r) of the near-field expansions (which are the same as those of the steady-state motion with the instantaneous velocity of the accelerating motion as the uniform velocity) by means of a conservation law involving the dynamic energy—momentum tensor. It is also shown that logarithmic terms of the near-field expansions are independent of the angular coordinate, a question that was posed in the past by David Barnett, and which is critical in this analysis. The self-force and effective mass for an accelerating dislocation depends essentially on that logarithmic singularity as shown by Eshelby and more generally by Ni and Markenscoff.
Chirality-Dependent Mechanical Behavior of Carbon Nanotubes Based on an Anisotropic Elastic Shell Model
Authors: Ru C.Q.
Published: December 2008

Motivated by recently reported chirality-dependent mechanical phenomena of small-radius carbon nanotubes, an anisotropic elastic shell model is developed in the present paper for small-radius single-walled carbon nanotubes. Due to curvature-derived elastic anisotropy, small-radius single-walled carbon nanotubes are better described by anisotropic plane-stress relations rather than graphite sheets of hexagonal symmetry which are governed by an isotropic plane-stress relation. Based on an orthotropic plane-stress elastic relation for zigzag and armchair single-walled carbon nanotubes, the suggested model is formulated for chiral single-walled carbon nanotubes of arbitrary chiral angle through a small-angle (less than π/12) rotation of the coordinate system. The results obtained show that the suggested anisotropic shell model can explain the chirality-dependent mechanical phenomena reported in the recent literature, and could be used to study chirality-dependent mechanical behavior of multi-walled carbon nanotubes of smaller innermost radii.
Extreme Lamé Compliance in Crystals of Trigonal Symmetry: the Case of α-Quartz
Authors: Wheeler Lewis
Published: December 2008

The variation of the Lamé compliance with direction is explored for elastic crystals associated with the trigonal class possessing six independent compliances (associated with point groups 32, 3 m, 3 m). A new decomposition of the compliance tensor is presented that simplifies the Lamé compliance by reducing the number of elastic parameters required to analyze how it varies with direction. The common form of quartz referred to as α-quartz falls within this class and is known to possess such interesting elastic properties as negative Poisson ratios. The Lamé compliance is a convenient indicator of this negativity and furnishes a sharp connection between its extreme directions and the underlying lattice orientation of the material.
Yielding and Strain Hardening in Metallic Thin Films on Substrates: an Edge Dislocation Climb Model
Authors: Nix W.D.
Published: December 2008

Yielding and strain hardening in metallic thin films on substrates are studied using a simple edge dislocation climb model, modified to mimic dislocation processes in passivated, single crystal FCC metal films with a (111) texture. The aim of the modeling is to produce closed-form solutions for the yield strength and rate of strain hardening that can be compared with experiment. The models give a good account of the dependence of the yield strength of passivated gold films on silicon substrates on the film thickness and they are in broad agreement with the experimental observation that plastic flow in passivated metal films is characterized by very high rates of strain hardening. However, these simple models fail to predict the observed decrease in the rate of strain hardening with increasing film thickness, a result that requires more computationally intensive discrete dislocation modeling.
Association between synapsin III gene promoter SNPs and multiple sclerosis in Basque patients
Authors: Otaegui D , Zuriarrain O , Castillo-Triviño T , Aransay AM , Ruíz-Martinez J , Olaskoaga J , Marti-Masso JF , Lopez de Munain A
Published: December 2008

Background

Synapsins are a family of neuron-specific phosphoproteins, one of whose subunits is encoded by the SYN3 gene. This gene is located close to one of the multiple sclerosis susceptibility regions (in 22q13.1). Two single-nucleotide polymorphisms (SNPs) (rs133945 and rs133946) in the promoter region of this gene have been proposed as factors protecting against MS. This relationship is not clear because another report failed to found such association.

Objectives

In an attempt to clarify this association, the frequency of these SNPs was analyzed in a population of 221 Spanish MS patients with a cluster of 72 Basque patients and in 373 controls with a cluster of 138 controls of a Basque origin.

Methods

The SNis analysis was performed by 9 PCR.

Results

According to our findings, these SNPs are differently distributed in the two populations. This significant bias should therefore be taken into account in association studies. Our data suggest that the C/C genotype in rs133946 and the G/G genotype in rs133945 could be protecting factors against MS in the Basque population.
Increase of CD4+TNFα+IL-2−T cells in cerebrospinal fluid of multiple sclerosis patients
Authors: Shi N , Kawano Y , Matsuoka T , Mei FJ , Ishizu T , Ohyagi Y , Kira J
Published: December 2008

Intracellular production of TNFα and IL-2 after stimulation with phorbol myristate/ionomycin was flowcytometrically measured in CD4+ T cells from peripheral blood (PB) and cerebrospinal fluid (CSF) of 29 patients with multiple sclerosis (MS), and 16 with other inflammatory and 41 with other non-inflammatory neurological diseases. In CSF, the percentages of CD4+TNFα+IL-2−T cells were significantly higher in patients with MS than either of the controls, whereas no difference was found in CD4+TNFα+IL-2+T or CD4+TNFα−IL-2+T cells. The increase was more pronounced at relapse than in remission. No significant change was detected in PB. These findings suggested that CD4+TNFα+IL-2−T cells are intrathecally upregulated in MS.
At-risk Mothers' Parenting Capacity: An Epistemological Analysis of Change Through Intensive Intervention
Authors: Worsham Nancy L. , Kretchmar-Hendricks Molly D. , Swenson Natalia , Goodvin Rebecca L.
Published: December 2008

Using an epistemological framework, we examine the process of change for two at-risk mothers participating in the Children's Ark, an innovative foster care program. The Children's Ark invited at-risk mothers who had lost custody of their children to live in a structured, supervised environment with their infants/toddlers while receiving intensive intervention. Focusing on two mothers who completed the program and regained custody of their children, we developed a coding system from Women's ways of knowing (Belenky, Clinchy, Goldberger, & Tarule, 1986) to analyze entry and discharge interviews, and as a means of exploring alternative conceptualizations to the helping professions' understanding of at-risk families. In terms of an epistemological framework, we found that mothers increased their capacity to acknowledge their own minds and voices and those of their children. Additionally, mothers came to recognize their capacity to generate knowledge, especially through dialogue and relationships with others. In conclusion, we discuss the utility of an epistemological perspective in describing and exploring change in at-risk mothers, including possible implications for practice.
Exploring Young Women's Understandings of the Development of Difficulties: A Narrative Biographical Analysis
Authors: Brooks Emily , Dallos Rudi
Published: December 2008

This article describes a qualitative research study which used in-depth interviews to elicit young women's narratives about the meanings they hold regarding the important experiences in their lives, and their understandings of the development of difficulties that have led them to be in contact with Child and Adolescent Mental Health Services (CAMHS). Five young women (aged 15—17 years) who were current users of CAMHS were interviewed. A narrative analysis was conducted on the data. The findings revealed how contact with services may have impacted on their developing sense of self during this important transitional period of their lives. The young women's stories differed in the extent to which they drew on themes of difficulties as indicators of illness or the result of difficult life events. Their sense-making appeared to be influenced by the relationships, contexts and discourses which they were exposed to and embedded within.
Intimate relationships and women involved in the sex trade: perceptions and experiences of inclusion and exclusion
Authors: Jackson Lois A. , Augusta-Scott Tod , Burwash-Brennan Marilee , Karabanow Jeff , Robertson Karyn , Sowinski Barbara
Published: December 2008

This article reports on a qualitative study exploring the intimate (non-work) relationships of women involved in the sex trade. Women working in the sex industry and intimate partners of women in the industry were interviewed in order to understand how intimate relationships are perceived as influencing the women's general health and well-being. The research suggests that intimate relationships can, and do, provide a space for feelings of inclusion and safety that are perceived as positive forces in women's general health and well-being. At the same time, however, feelings and experiences of exclusion (fuelled by the dominant stigmatizing discourse related to prostitution) can enter into intimate relationships, and are perceived as having a negative impact on the women's well-being, particularly their emotional health. Although there are attempts to keep the women's work separate from the intimate relationship, cross-over between the two spheres does occur. The research suggests that health care and service providers need to look beyond the women's working lives, and understand the relationships between work and home, as well as the ways in which intimate relationships can influence women's lives and health through both positive and negative forces.
How Perspective-Taking Helps and Hinders Group-Based Guilt as a Function of Group Identification
Authors: Zebel Sven , Doosje Bertjan , Spears Russell
Published: December 2008

In two studies we hypothesized that outgroup perspective-taking promotes group-based guilt among weakly identified perpetrator group members, but hinders it among higher identifiers. In Study 1, native Dutch participants ( N = 153) confronted their group's past mistreatment of outgroups, while perspective-taking was manipulated. This manipulation significantly increased guilt among lower identifiers, but decreased guilt among higher identifiers. In addition, guilt predicted positively participants' support for reparation. In Study 2 ( N = 217), we replicated this interaction and elaborated on its underlying processes. As predicted, perspective-taking positively predicted feelings of compassion for outgroup members, as well as the perceived responsibility of the ingroup for the harm inflicted. Path analyses indicated the dual role of compassion: it predicted guilt positively among lower identifiers, but negatively among higher identifiers. The double-edged potential of perspective-taking for improving relations between groups that have a history on conflict is discussed.
Denmark, Sweden and Norway
Authors: Lund Anker Brink , Berg Christian Edelvold
Published: December 2008

The demonopolization of public service radio and television in Europe has brought about tougher competition in market terms. This, in turn, has made the conduct of broadcasters more businesslike. Public regulators, therefore, have attempted to secure programme diversity at a higher level than would be the case under strict commercial conditions. In Scandinavia, one important way of doing this has been to license hybrid channels that, while being financed by advertising, are at the same time acting under public service obligations with nationwide, terrestrial must-carry privileges. The authors evaluate these regulatory measures on data from Norway, Sweden and Denmark in terms of audience share and open and reflexive diversity, and conclude that the Scandinavian way of conducting co-regulation could serve as an inspiration to regulators around the world — especially in EU member states.
Belgium
Authors: d'Haenens Leen , Antoine Frédéric , Saeys Frieda
Published: December 2008

Although Belgium's broadcasting history can be considered a perfect example of the overall situation in Western Europe, the country's specific cultural makeup and political shifts are also reflected in its media environment. The media system is characterized by a fairly high degree of cross-ownership, while major differences can be found in the degree of cultural protection. This article examines the stances being taken in the French- and Flemish-Speaking Communities: contextually, in terms of cross-ownership regulation; institutionally, as to the mission of the public broadcaster ( pur sang or broader); and content-wise, with respect to home-grown, high identity value productions, as opposed to transnational productions from foreign players.
Switzerland
Authors: Künzler Matthias
Published: December 2008

Diversity is an important guiding principle of Switzerland's overall policy and media policy since the country consists of different political and economic entities but also of three language regions. Surprisingly, only weak media concentration regulations were introduced to protect media diversity. This article looks for the reasons behind this paradoxical situation by examining parliamentary debates about media and competition regulations. It becomes apparent that decision-makers encouraged cross-media ownership assuming that it would strengthen regional publishing houses in order to maintain regional diversity within the country. Alongside this goal was with the intention to establish a strong public service broadcaster, which would enable comprehensive domestic programmes despite the high market shares of foreign broadcasting stations.
Diversity through Delay?
Authors: Steinmaurer Thomas
Published: December 2008

The media system in Austria can be seen as a typical example of a small state market with a giant next-door neighbour sharing the same language. In addition to an extraordinary high concentration rate in the print media market, the delay in liberalizing the broadcasting market — wherein politics still maintains a strong position — led to the strengthening of the public broadcaster's position and therefore helped to maintain a certain kind of programme diversity. New challenges now arising from European competition law concerning the role of PSBs in the broadcasting market make very real the question of media diversity in a changing regulation environment.
Keeping Up Appearances
Authors: Sousa Helena , Costa e Silva Elsa
Published: December 2008

Since the end of a 50-year-long authoritarian regime in Portugal in the mid-1970s, political discourses and legal texts have incorporated media diversity as a fundamental democratic value. The 1976 Constitution prohibited cross-media concentration and subsequent media legislation contemplated pluralism as a vital societal dimension. This recognition, however, has always been expressed in vague, ineffectual terms as no government has ever had a real interest in preventing concentration of media ownership or in guaranteeing broadcasting content diversity. In an ever fragile political environment, governments have either encouraged `friendly' media groups or, fearing adverse reaction, abstained from acting against the perceived interests of the established ones. Taking advantage of the smallness of the country, media owners have efficiently argued that scale was necessary to maintain the media in national hands, and that concentration in itself was a guarantee of media content diversity. The `foreign enemy' argument has served the interests of both successive governments and domestic multimedia groups.
The European and Global Dimension
Authors: Puppis Manuel , d'Haenens Leen , Steinmaurer Thomas , Künzler Matthias
Published: December 2008

State size matters. However, small states do not only share structural peculiarities but also feature different political and historic traditions. This helps explain why the connection between smallness and media regulation is far from clear. Thus, it is suggested here to amend existing typologies of media systems with the notion of smallness, which would allow for more systematic comparative research. In addition, future research on small states needs to consider issues of Europeanization and globalization, examining the role of small states in decision-making on the supranational and international level.
Organized fraud and organizing frauds
Authors: Levi Michael
Published: December 2008

This article examines the settings for frauds in the context of crime networks, fraud opportunities and of a victim-centric typology of fraud. It demonstrates the variety of actors, settings and the variable need for knowing collaboration between co-offenders in frauds of different types. It explores what is known about those involved in the organization of some forms of frauds; how they find both co-offenders and victims in face-to-face and remote settings; and the barriers to growth of the `fraud business'. It concludes that the globalization of crime is part of contingent relationships between settings, with their rich and varied opportunities (reflecting patterns of business, consumer and investment activities), the variable abilities of would-be perpetrators to recognize and act on those opportunities (the `crime scripts' perspective), and their interactions with controls (including, but not restricted to, law enforcement). Constructs of `organized crime' are becoming less obsessed with the structure of groups than with what people need from the largely illicit and largely licit worlds before they commit fraud. Although some frauds are committed by generic transnational `organized crime' networks, others are merely mobile small groups or individuals who can transplant techniques wherever they go; and others still commit very large one-off frauds without a need for long-term or any involvement in `organized crime'.
Human trafficking
Authors: Goodey Jo
Published: December 2008

This article looks at the phenomenon of trafficking in human beings, with examples drawn from intergovernmental organizations, the European Union and the UK. It begins by outlining legal recognition of and current responses to trafficking, and goes on to present an overview of what we currently know and don't know about the extent and nature of this crime in relation to its various manifestations. The article critically examines policy responses to trafficking in the light of what are often, at best, sketchy data. The existence of a trafficking `industry', both as an organized crime `industry' and as an IGO and NGO `industry', is introduced in the arcicle through legal and policy responses that set out to identify, map and counter trafficking. The article concludes by asking where the focus on trafficking is heading, and if it will be supported in future by more robust evidence for policy development.
Researching the organization of serious crimes
Authors: Edwards Adam , Levi Michael
Published: December 2008

In a sense, the problem of organized crime is the concept of `organized crime' itself. The implications of shifting the analytical focus from explanations of `it' toward building theories of the organization of serious crimes are considered in relation to three ways of framing research: organized crime as an external threat; the organization of serious crimes through routine activities; and their organization through social relations. Beyond taxonomic assessments of various threats, organized crime groups, their regional theatres of operation and involvement in illicit markets, a major fault-line exists within social scientific studies of the organization of serious crimes over the appropriate scope of inquiry. Specifically, whether this should be limited to the particular settings in which discrete serious crime events occur and/or broadened to encompass the social structural antecedents of these events. This boils down to an argument over what constitutes the necessary relations for the commission of serious crimes for economic gain, and how their contingent concentration in certain places and moments amongst particular populations can be adequately explained. This also suggests that the interplay between more remote `distal' causes, situational opportunities presented by public and private sector controls, and pre-existing networks of relationships have to be understood in combination for an adequate explanatory account of the organization of crimes.
Building memory: Architecture, networks and users
Authors: Guggenheim Michael
Published: December 2008

Why are buildings such disputed objects with regard to time and memory, and what makes them peculiar? With the help of actor-network theory and the theory of functional differentiation, I show how objects in general relate to time and how objects can stabilize memories. I demonstrate the different ways in which networks place objects in time and how they are isolated and multiplied to relate to functional systems. I then argue that buildings cannot be controlled by functional systems because they cannot be isolated. This is so because they are singulars, occupy a stable location and are used by multiple users at the same time. For this reason I call them mutable immobiles. As mutable immobiles, buildings develop very complex relationships to times. They are changed and even converted to other building types, which cuts them off from their networks even though they still occupy the same location.
The place of trauma: Memory, hauntings, and the temporality of ruins
Authors: Trigg Dylan
Published: December 2008

Implicit in theoretical treatments of the memory of trauma is the fragmented reception of the past. While a great deal of research has approached this issue from the perspective of oral testimony, what has remained underdeveloped is the role sites of memory play in contributing to our understanding of trauma. Accordingly, in this article, I intend make a foray into this convergence between place and trauma through undertaking a phenomenological investigation of the testimonial attributes of ruins. In doing so, I will pursue two central questions. First, insofar as the built environment is able to contain memory, how does the place of trauma testify to history? Second, if ruins are by their nature contingent and dynamic, how can the past be spatially preserved without creating a false unity between time and the event? In response to these questions, I will put forward the notion that sites of trauma articulate memory precisely through refusing a continuous temporal narrative. My conclusion is that the appearance of the ruin, understood phenomenologically, allows us to approach the spatio-temporality of trauma in terms of a logic of hauntings and voids.
Distinct functions of Wnt/β-catenin signaling in KV development and cardiac asymmetry
Authors: Lin Xueying , Xu Xiaolei
Published: December 2008

The Wnt/β-catenin pathway exhibits distinct and developmental stage-specific roles during cardiogenesis. However, little is known about the molecular mechanisms of Wnt/β-catenin signaling in the establishment of cardiac left-right (LR) asymmetry. Using zebrafish as an animal model, we show here that Wnt/β-catenin signaling is differentially required in cardiac LR patterning. At an early stage, during asymmetric signal generation,Wnt/β-catenin signaling is necessary for Kupffer's vesicle development and for the regulation of both heart and visceral laterality. At a later stage, during asymmetric signal propagation, excessive Wnt/β-catenin signaling inhibits the transmission of asymmetric cues from the lateral plate mesoderm (LPM) to the cardiac field but not to the developing gut; as such, it only regulates heart laterality. Molecular analysis identifies Gata4 as the downstream target of Wnt/β-catenin signaling in the cardiac field that responds to the Wnt/β-catenin signaling and regulates the competence of the heart field to express left-sided genes. In summary, our results reveal a previously unexpected role of Wnt-Gata4 signaling in the control of asymmetric signal propagation from the LPM to the cardiac field.
Evaluation of the Modification of Diet in Renal Disease equation (eGFR) against simultaneous, dual-marker multi-sample measurements of glomerular filtration rate
Authors: Peters A Michael , Bird Nicholas J , Halsall Ian , Peters Christina , Michell A Robert
Published: December 2008

Background

Estimation of glomerular filtration rate (GFR) using plasma creatinine remains controversial, especially when GFR approaches normal values. The aim was to re-examine estimated GFR (eGFR) using dual-reference GFR measurements.

Methods

eGFR (simplified modified Modification of Diet in Renal Disease equation) was compared with GFR measured with iohexol for predicting GFR measured with 51Cr-ethylenediaminetetraacetic acid (EDTA). Dual six-sample GFR (20–240 min postinjection) was measured in 60 patients and 20 normal volunteers with 51Cr-EDTA (GFREDTA) and iohexol (GFRiohexol) injected into separate arms and sampled contralaterally. This was repeated in the normal volunteers under fasting conditions (twice in nine). Percentage bias, imprecision (SD of bias) and disagreement (sign-less difference) between eGFR and GFREDTA were compared with those between GFRiohexol and GFREDTA.

Results

Changes between fasting and postprandial eGFR correlated significantly with corresponding changes in GFRiohexol and GFREDTA. eGFR predicted GFREDTA less precisely (SD 19.9%) than GFRiohexol (10.5%; P < 0.01). Although eGFR showed a poorer correlation with GFREDTA when GFREDTA > 80 mL/min/1.73 m2 compared with <80 mL/min/1.73 m2, there was no significant difference with respect to imprecision or disagreement of >20 or 30%. However, eGFR was closer than GFRiohexol to GFREDTA in a higher fraction of studies when GFREDTA > 80 mL/min/1.73 m2 (28/60) than when it was <80 mL/min/1.73 m2 (9/37; P < 0.05).

Conclusion

eGFR is inferior to GFRiohexol for predicting GFREDTA. The disagreement between GFRiohexol and GFREDTA illustrates the extent to which uncertainty in GFREDTA contributes to the performance of eGFR. eGFR performs no better at lower, compared with higher levels of GFR.
Family tracing to identify patients with Familial Hypercholesterolaemia: the second Audit of the Department of Health Familial Hypercholesterolaemia Cascade Testing Project
Authors: Hadfield S G , Horara S , Starr B J , Yazdgerdi S , Marks D , Bhatnagar D , Cramb R , Egan S , Everdell R , Ferns G , Jones A , Marenah C B , Marples J , Prinsloo P , Sneyd A , Stewart M F , Sandle L , Wang T , Watson M S , Humphries S E
Published: December 2008

Background

Family tracing is a method recognized to find new patients with familial hypercholesterolaemia (FH). We have implemented family tracing led by FH Nurses and have determined acceptability to patients, feasibility and costs.

Methods

Nurses were located at five National Health Service (NHS) Trusts; they identified FH patients and offered them family tracing. Responses and test results were recorded on a database and summarized on a family pedigree.

Results

The majority (∼70%) of index cases participated; the proportion was lower when patients had been discharged from the clinics and in metropolitan areas. On average, 34% (range 13–50%) of relatives lived outside the catchment area of the clinics and could not attend the nurse-led FH clinics. Of the previously untested relatives, 76% who lived in the catchment area of the clinic came forward to be tested. One-third of the relatives who came forward for testing were children ≤16 y of age. The proportion of relatives diagnosed as likely to have FH was lower than would be predicted (30% vs. 50%). This was mainly due to the uncertainty of a diagnosis based on lipid measurements. The average cost to identify and test one relative was approximately £500 but was higher in the metropolitan areas.

Conclusion

Cascade testing for FH in the UK is feasible, acceptable and likely to be cost-effective if it is a routine aspect of clinical care. However, national implementation would require an integrated infrastructure, so that all individuals have access to testing, and specialist services for the management of young people.
Appropriate laboratory utilization in diagnosing pulmonary embolism
Authors: Eva Fiappo , Rosanna Quattrin , Laura Calligaris , Piero Cappelletti , Silvio Brusaferro
Published: December 2008

Background

The appropriateness of clinical laboratory use in hospital clinical practice is a very debated question. In fact diagnostic tests are essential tools for disease screening or diagnosis but at the same time they represent an important expenditure.

Methods

A quantitative study was conducted in an Italian general hospital with 535 beds and about 27,000 admissions per year. The sample was made of all patients discharged from the hospital with DRG 78 between the period 1 January 2005 and 31 December 2005.

Results

The Emergency Department (ED) discharged 2.9% (116/4009) of patients with pulmonary embolism diagnosis in the year 2005. The percentage of prescription inappropriateness inferred by analysis of all required tests by operative unit was 21.7% (950/4385). The approximate estimate of the economic value of unnecessarily required tests was of 3495€. Of these 96.5% (112/116) had enlisting criteria. All haematological and clinical-chemical tests (1295) concerning studied patients were analysed. About 70.4% (93/132) of d-dimer tests were ordered in ED. In the studied patients, unfractionated heparin was administered in 17.8% (20/112) of the cases, low-molecular weight heparin in 79.5% (89/112) and heparin therapy was not administered in 2.7% (three of 112).

Conclusion

This study uses a method to assess the quality of laboratory test orders using results as a tool to estimate the impact of economic resources devolved in executing inappropriate tests.
Criteria for opiate identification using liquid chromatography linked to tandem mass spectrometry: problems in routine practice
Authors: Fox Elizabeth J , Twigger Shirley , Allen Keith R
Published: December 2008

Background

Liquid chromatography linked to tandem mass spectrometry (LC/MS/MS) is being increasingly used for drug confirmation. At present, no official criteria exist for drug identification using this technique although the European Union (EU) criteria for compound identification have been adopted. These criteria are evaluated with respect to opiate confirmation by LC/MS/MS and problems highlighted.

Methods

Urine samples screened positive for opiates by immunoassay were subjected to confirmation by LC/MS/MS using multiple reaction monitoring (MRM) and two separate buffer systems of pH 6.8 and 8.0, respectively. The EU criteria for compound identification were applied for confirmation of morphine, 6-monoacetylmorphine (6MAM), codeine and dihydrocodeine (DHC).

Results

Using the pH 6.8 buffer, confirmation could be achieved for 84%, 94%, 96% and 95%, respectively, for samples demonstrating MRM chromatographic peaks at retention times for morphine, 6MAM, codeine and DHC. Failure to meet the EU criteria was mainly attributed to low signal-to-noise (S:N) ratios or excessively high drug concentrations. Isobaric interferences and poor chromatography were also contributing factors. The identification of morphine was considerably improved with chromatography at pH 8.0 owing to resolution of interferences. Oxycodone metabolites were a potential problem for the identification of DHC.

Conclusion

Isobaric interferences can pose a problem with drug identification using LC/MS/MS. Optimizing chromatographic conditions is important to overcome these interferences. Consideration needs to be given to investigating drug metabolites as well as parent drugs in method development.
Development and validation of an improved test for the measurement of human faecal elastase-1
Authors: Kampanis Petros , Ford Loretta , Berg Jonathan
Published: December 2008

Background

Human faecal elastase-1 (FE-1) is an established biochemical test for the investigation of pancreatic exocrine insufficiency. Conventional extraction methods for FE-1 analysis can give false-positive results with watery stools. This is a major limitation as patients investigated for pancreatic disease commonly produce such stools. We have developed an improved FE-1 test that overcomes water interference by measuring the enzyme in dried faeces.

Methods

A novel collection device for FE-1 analysis that involves drying and weighing the stool sample was developed in our laboratory and compared with a conventional wet method, E1 Quick-Prep (Schebo, Biotech AG, Germany). The concentration of faecal FE-1 was determined using a commercially available enzyme-linked immunosorbent assay method (Schebo).

Results

FE-1 values obtained using the new dry extraction procedure (mean 1777 μg/g dry stool) were higher when compared with the conventional wet analysis (mean 402 μg/g stool). A 1:2 dilution in water, mimicking a loose stool, was found to affect FE-1 results obtained using the conventional wet extraction procedure. The new dry extraction method gave consistent results when water content was varied in the original stool sample.

Conclusion

We have demonstrated that our new device overcomes water interference, allowing results to be obtained from stool samples that would otherwise be unsuitable for FE-1 analysis.
Lithocholic acid as a biomarker of intrahepatic cholestasis of pregnancy during ursodeoxycholic acid treatment
Authors: Lucangioli Silvia E , Castaño Gustavo , Contin Mario D , Tripodi Valeria P
Published: December 2008

Background

The diagnosis and treatment of intrahepatic cholestasis of pregnancy (ICP) has important implications on fetal health. The biochemical parameter commonly used in the diagnosis of ICP is the determination of the concentration of total serum bile acids (TSBA). However, bile acid profile, especially lithocholic acid (LCA) analysis is a more sensitive and specific biomarker for differential diagnosis of this pathology and also could be an alternative to evaluate the efficiency of ursodeoxycholic acid (UDCA) for ICP treatment.

Methods

Serum bile acid (SBA) profiles including LCA determination, were studied in 28 ICP patients using a capillary electrophoresis method. The effects of UDCA treatment on bile acid profile, were analysed in 23 out of 28 ICP patients and the two samples obtained before and 15 days after treatment were compared. Two samples taken as controls were also obtained from each of five patients without therapy.

Results

A dramatic decrease in LCA concentrations and maintenance of TSBA concentrations were found in all patients after UDCA therapy, whereas SBA profiles together with LCA values did not change in patients without therapy.

Conclusion

We propose LCA as an alternative biomarker and a more sensitive parameter than TSBA to evaluate the effectiveness of UDCA treatment, at least in ICP patients from Argentina.
A meta-analysis of leptin reference ranges in the healthy paediatric prepubertal population
Authors: Venner Allison A , Doyle-Baker Patricia K , Lyon Martha E , Fung Tak S
Published: December 2008

Objective

The initial discovery of leptin (1994) has given rise to a substantial number of published studies. This study aimed at identifying the published data on the reference ranges of total, free and bound leptin concentration in the healthy prepubertal population.

Methods

A search was conducted on original English language studies published from 1994 to 2005 in the following databases: PubMed ( n = 58), EMBASE ( n = 4), Biological Abstracts ( n = 2) and Science Finder Scholar ( n = 66). A cited reference search was completed in Science Citation Index on studies with a leptin range. A meta-analysis was completed on included studies containing a dataset and a sample size for a leptin concentration range and/or mean±standard deviation for a healthy prepubertal population. Preanalytical and analytical variations were examined. Preanalytical variables included aspects such as fasting state and gender, while analytical variation comprised the type of leptin assay methodology.

Results

Twelve studies met the inclusion criteria. One study examined free leptin; 11 studies examined total concentration. No studies reported leptin reference ranges established by Clinical and Laboratory Standards Institute (CLSI) criteria, although four studies reported specific study leptin ranges. The methodology of enzyme-linked immunosorbent assay demonstrated a wider leptin range than radio immunoassay (0.56–36.35 vs. 1.01–12.21 ng/mL). Males had a significantly lower mean leptin concentration than females ( P = 0.0006); obese children had a higher concentration than non-obese ( P = 0.0001).

Conclusion

No studies have established CLSI-based leptin reference ranges in prepubertal healthy children and there is a wide variation in the published leptin concentrations. These differences suggest that caution should be used in the interpretation and comparison between studies.
Cost-effectiveness of voluntary HIV screening in Russia
Authors: Tole S P , Sanders G D , Bayoumi A M , Galvin C M , Vinichenko T N , Brandeau M L , Owens D K
Published: December 2008

Russia has one of the world's fastest growing HIV epidemics, and HIV screening has been widespread. Whether such screening is an effective use of resources is unclear. We used epidemiologic and economic data from Russia to develop a Markov model to estimate costs, quality of life and survival associated with a voluntary HIV screening programme compared with no screening in Russia. We measured discounted lifetime health-care costs and quality-adjusted life years (QALYs) gained. We varied our inputs in sensitivity analysis. Early identification of HIV through screening provided a substantial benefit to persons with HIV, increasing life expectancy by 2.1 years and 1.7 QALYs. At a base-case prevalence of 1.2%, once-per-lifetime screening cost $13,396 per QALY gained, exclusive of benefit from reduced transmission. Cost-effectiveness of screening remained favourable until prevalence dropped below 0.04%. When HIV-transmission-related costs and benefits were included, once-per-lifetime screening cost $6910 per QALY gained and screening every two years cost $27,696 per QALY gained. An important determinant of the cost-effectiveness of screening was effectiveness of counselling about risk reduction. Early identification of HIV infection through screening in Russia is effective and cost-effective in all but the lowest prevalence groups.
Condom use in the year following a sexually transmitted disease clinic visit
Authors: Peterman T A , Tian L H , Warner L , Satterwhite C L , Metcalf C A , Malotte K C , Paul S M , Douglas J M ,   the RESPECT-2 Study Group
Published: December 2008

Consistent condom use can prevent sexually transmitted infections (STIs), but few studies have measured how the prevalence of consistent use changes over time. We measured the prevalence and correlates of consistent condom use over the course of a year. We did a secondary analysis of data from an HIV prevention trial in three sexually transmitted disease clinics. We assessed condom use during four three-month intervals for subjects and across their partnerships using unconditional logistic regression. Condom use was also assessed for subjects during all three-month intervals combined. The 2125 subjects reported on 5364 three-month intervals including 7249 partnership intervals. Condoms were always used by 24.1% of subjects and 33.2% of partnerships during a three-month interval. Over the year, 82% used condoms at least once but only 5.1% always used condoms. Always use of condom was more likely for subjects who had sex only once (66.5%) compared with >30 times (6.4%); one-time partnerships (64.1%) compared with main partnerships (22.2%); and in new partnerships (44.0%) compared with partnerships that were not new (24.5%). Although consistent condom use may prevent STIs, condoms were rarely used consistently during the year of follow-up.
Can a clinical prediction tool guide HIV-testing decisions? Experience at a national hospital in Guatemala
Authors: Anderson M R , Samayoa B , O'Sullivan L F , Fletcher J , Arathoon E
Published: December 2008

The USA and international recommendations no longer emphasize using risk factors to target groups for HIV-testing. Using a Guatemalan database of HIV tests, we developed a clinical prediction rule to guide decisions on HIV-testing. Prior to HIV-testing, data were collected on demographics, risk factors and prior testing. Based on a theoretical construct incorporating demographics, known HIV risk factors and symptoms, we developed a logistic regression model to predict HIV seropositivity. Between 2000 and 2005, 16,471 tests were performed, of which 19.8% were positive. The algorithm successfully predicted 1883 of 2489 HIV-positive tests (sensitivity 76%, likelihood ratio [LR]-positive 2.45) and 6282 of 9086 HIV-negative tests (specificity 69%, LR-negative 0.35). Although the model indices are robust, applying the model in a clinical setting would have little impact on improving selective testing practices. Our findings support current recommendations for universal HIV-testing, not selective testing based on risk factors. Before these recommendations can be adopted widely in Guatemala, treatment access needs to be assured and protections put in place for people diagnosed with HIV infection.