bluuebunny/crossref_metadata_2025 huggingface dataset:
Legal Issues in Home Care: Current Trends, Risk-Reduction Strategies, and Opportunities for Improvement
Authors: Dailey Maureen , Newfield James
Published: January 2005

Home health nurse malpractice litigation and judgments are increasing. The legal and home health practice environments are evolving in streams of tumultuous change. The legal view of nurse practice lags behind the realities of nurse practice. Evidence-based practice is evolving and becoming the expected standard of practice. This article summarizes the current home health malpractice trends and identifies current factors affecting change in both the legal and home health environments. Strategies and resources to reduce nurse malpractice risk in home care are discussed.
Vastus lateralis vastus medialis obliquus muscle activity during the application of inhibition and facilitation taping techniques
Authors: Janwantanakul Prawit , Gaogasigam Chitanongk
Published: January 2005

Objective: To evaluate the effect of inhibition and facilitation taping techniques on the activity of vastus lateralis and vastus medialis obliquus.

Design: Repeated-measures design.

Setting: Laboratory in an educational institution.

Subjects: Thirty healthy females aged between 18 and 23 years.

Intervention: Subjects were tested during the application of inhibition tape, facilitation tape and no tape to vastus lateralis in random order.

Main outcome measures: Electromyographic activity of vastus lateralis and vastus medialis obliquus during stair descent was recorded using bipolar surface electrodes.

Results: Electromyographic activity of vastus lateralis and vastus medialis obliquus during the application of inhibition tape or facilitation tape did not alter significantly compared with no tape condition.

Conclusions: Taping designed to inhibit or facilitate muscle activity via sensory stimulation does not affect vastus lateralis or vastus medialis obliquus activity in healthy subjects. Further investigation is required to find a means of muscle taping that could be recommended as an intervention for patients with patellofemoral pain syndrome.
A national survey of health professionals and volunteers working in voluntary hospices in the UK. II. Staff and volunteers' experiences of working in hospices
Authors: Addington-Hall Julia M , Karlsen Saffron
Published: January 2005

In this paper we report findings of a 1999 nationally representative survey of independent hospices in the UK, focusing on hospice staff and volunteers' experiences of working in hospices. Nineteen of 25 sampled services participated, and these differed little in terms of service provision, size and region from the total sample of 175 services. A response rate of 70% for randomly sampled hospice staff and volunteers was achieved (n504). There were significant intergroup differences (doctors, nurses, nursing auxiliaries, other staff and volunteers) in participants' reported experience of working in the hospice with, for example, doctors being more likely than other groups to feel appreciated and to report receiving adequate support from hospice management. Overall, 31% of respondents wanted more support from management. Half had considered leaving the hospice (65% nurses, 60% other staff, 55% nursing auxiliaries, 40% doctors and 37% volunteers). Nurses who had considered leaving were less satisfied than other nurses with, for example, support from hospice management, and less likely to feel valued by the hospice. These results raise questions about the quality of the relationship between hospice trustees, managers and staff, and about the realities of enhancing multiprofessional teamwork in organizations where there are significant differences between staff groups in perception of, and satisfaction with, the working environment. Voluntary hospice trustees and managers face a difficult task in managing and supporting staff whilst also negotiating relationships with the NHS at a time of rapid change, and ensuring hospices' financial viability. Access to high quality leadership programmes may play an important role in ensuring voluntary hospices are characterized by effective, supportive working relationships.
Introducing an integrated care pathway for the last days of life
Authors: Mirando Sally , Davies Paul D , Lipp Allyson
Published: January 2005

Integrated care pathways (ICPs) are multiprofessional documents designed to enable the implementation of evidence-based care and support the practical delivery of clinical governance. However, the implementation of care pathways is resource intensive and few evaluations have been conducted with respect to these areas or to the efficacy of care pathways to change practice and improve outcomes in care. This project sought to address these issues and the report outlines the approach taken by a palliative care team in South Wales, UK, to implement a care pathway for the dying throughout a district general hospital and six community hospitals. Dying can be a complex area of care and changing practice can be challenging, therefore a PRINCE Project management approach was taken and a full-time project nurse employed for the life of the project. This paper describes the strategies used to approach implementing a care pathway and provides a template for other teams who may embark on similar projects. At the end of the project, the care pathway was successfully implemented and provided demonstrable outcomes of care for those dying from cancer and nonmalignant diseases. Strikingly, a large number of patients dying from nonmalignant disease were cared for via the pathway, which was not expected.
The stresses of volunteering in a hospice: a qualitative study
Authors: Dein Simon , Abbas Syed Qamar
Published: January 2005

Objectives: This study examined the stresses associated with hospice volunteering, ways of coping and perception of available support. Methods: Two focus groups were conducted comprising 17 volunteers. The data obtained were transcribed and analysed using thematic analysis. Results: Reported stressors included losing patients and dealing with disfigurement. However, informants generally reported the work as satisfying and generally stress free. Coping strategies ranged from keeping a distance from clients, religious faith, to the realization that death was a merciful end and was not necessarily painful. Informants generally perceived support to be adequate. Conclusions: The implications of these findings for training volunteers are discussed, especially the need to educate volunteers about the symptoms and signs of cancer.
Nasal dermoid sinus cysts in adults
Authors: Vaghela H.M. , Bradley P.J.
Published: January 2005

Nasal dermoid sinus cysts (NDSC) are rare congenital lesions that most frequently present in children, but have been reported in adults.

This article reviews adult (more than 16 years of age) nasal dermoid sinus cysts as they present, their radiological investigation, surgical approach and outcome. Thirty-eight previously published cases are reviewed, to which a further six cases are added.

All 44 cases are tabulated and reviewed. The risk of intracranial extension is 27.5 per cent, especially men with a dermal sinus. Recurrences are likely if the NDSC is not completely excised.

Curative treatment is surgical. It is recommended that all adults who present with a dermal cyst and/or sinus in the region of the nasal dorsum should be investigated by computed tomography (CT) and/or magnetic resonance (MRI). This is to delineate deep tissue involvement and to exclude a possible associated intracranial extension, prior to recommending surgical excision.
Pathophysiology and diagnostic value of urinary trypsin inhibitors
Authors: Pugia Michael J. , Lott John A.
Published: January 2005

Inflammation is an important indicator of tissue injury. In the acute form, there is usually accumulation of fluids and plasma components in the affected tissues. Platelet activation and the appearance in blood of abnormally increased numbers of polymorphonucleocytes, lymphocytes, plasma cells and macrophages usually occur. Infectious disorders such as sepsis, meningitis, respiratory infection, urinary tract infection, viral infection, and bacterial infection usually induce an inflammatory response. Chronic inflammation is often associated with diabetes mellitus, acute myocardial infarction, coronary artery disease, kidney diseases, and certain auto-immune disorders, such as rheumatoid arthritis, organ failures and other disorders with an inflammatory component or etiology. The disorder may occur before inflammation is apparent. Markers of inflammation such as C-reactive protein (CRP) and urinary trypsin inhibitors have changed our appraisal of acute events such as myocardial infarction; the infarct may be a response to acute infection and (or) inflammation.

We describe here the pathophysiology of an anti-inflammatory agent termed urinary trypsin inhibitor (uTi). It is an important anti-inflammatory substance that is present in urine, blood and all organs. We also describe the anti-inflammatory agent bikunin, a selective inhibitor of serine proteases. The latter are important in modulating inflammatory events and even shutting them down.
The predictive power of serum κ/λ ratios for discrimination between monoclonal gammopathy of undetermined significance and multiple myeloma
Authors: Bergón Enrique , Miravalles Elena , Bergón Elena , Miranda Isabel , Bergón Marta
Published: January 2005

The predictive power of serum κ/λ ratios on initial presentation of immunoglobulin G (IgG) or IgA monoclonal component was studied to differentiate between monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM) patients. The retrospective study involved 145 patients clinically diagnosed with monoclonal gammopathy of undetermined significance or multiple myeloma, who had serum M-protein IgG <35g/L or IgA <20g/L at M-protein detection. Serum light chains κ and λ were measured by fixed-time nephelometry. Test performance indices, predictive values and likelihood ratios were calculated according to the Weissler recommendation. MM patients were considered as diseased and MGUS patients as non-diseased in order to estimate the performance characteristics of serum κ/λ ratios. There was a statistically significant difference in κ/λ ratios distribution between both groups of patients, in both M-protein κ-type (Mann-Whitney U=168, p<0.001) and in M-protein λ-type (Mann-Whitney U=143, p<0.001). Negative likelihood ratios at threshold levels of 0.6 and 4.2 were 2.17- and 3.32-fold greater, respectively, than positive likelihood ratios, so that the predictive power of a serum κ/λ ratio within these limits is better in ruling out (negative predictive power) than ruling in disease (positive predictive power). The post-test characteristics of a serum κ/λ ratio interval between 0.6 and 4.2 in discriminating MGUS from MM in our geographic population were: sensitivity 0.96 (0.93–0.99 95%CI); specificity 0.70 (0.63–0.77); positive predictive value 0.68 (0.64–0.73); negative predictive value 0.96 (0.94–0.99); likelihood ratios (+)LR 3.23 (2.68–4.04); and (−)LR 17.16 (11.00–63.00). Thus, serum M-protein with a κ/λ ratio between 0.6 and 4.2 increases the posterior probability of MGUS from 0.60 to 0.96 in asymptomatic patients, for whom only monitoring may be suggested when the serum κ/λ ratio is within these limits.
Interference of dextran in biuret-type assays of serum proteins
Authors: Delanghe Joris R. , Hamers Nicole , Taes Youri E. , Libeer Jean-Claude
Published: January 2005

Dextran interference in biuret-type assays of total serum proteins was investigated in a Belgian National External Quality Assurance Survey with 256 participants. In vitro supplementation of therapeutic (10% Gentran 70
The late Greco-Roman and Byzantine contribution towards the evolution of laboratory examinations of bodily excrement. Part 2: sputum, vomit, blood, sweat, autopsies
Authors: Diamandopoulos Athanasios A. , Goudas Pavlos C.
Published: January 2005

Although the establishment of medical laboratory institutions was a continuous process that matured only after the 16th century, several attempts had already been made to attain a diagnosis by investigating bodily excrement. In the first part of our work, published in a previous issue of this journal, we presented data on urine, sperm, menses and stools. In this paper we present data on sputum, vomit, blood, sweat, and autopsies, thus completing the list of human materials used for laboratory examinations. All the data used are extracted from codices of Late Antiquity and Byzantium and translated by us. We did not study medical texts from the other great ancestors of Western medicine, namely Arabic and Jewish writings. From the texts cited, it is apparent that the lack of technological means was no obstacle for the doctor to create an “examinational” mind, i.e., to try to correlate the macroscopic findings in the excrement with the pathophysiological mechanism that induced them, solely with the use of the senses. This not only applies to the examination of urine, as is commonly assumed, but also to many other excrements of the upper and lower orifices of the body, as well as the human body as a whole.
Driving and Side Task Performance: The Effects of Display Clutter, Separation, and Modality
Authors: Horrey William J. , Wickens Christopher D.
Published: January 2005

In-vehicle technologies (IVTs) create additional tasks for the driver. To the extent that these devices degrade driving performance, there will be safety concerns. This study examines the effects of display clutter from overlay, display separation, and modality on driving and IVT task performance. In a fixed-base simulator, 22 drivers drove different routes and responded to infrequent, unexpected road hazards while engaging in a phone number task presented by different displays. Visual displays were located on a head-up (overlaid on the visual horizon or adjacently, just above the vehicle hood) or head-down display (HDD) located near the midconsole. Alternatively, digits were presented auditorily. In general, there were no differences in performance for the adjacent and overlay displays; however, there were costs associated with the HDD and auditory display for some measures. In particular, responses to hazard events were slowed when drivers used the HDD. Overall, the adjacent display best supported performance on all relevant tasks. Potential applications of this research include the design of IVTs with respect to location and modality.
Speech-Based E-Mail and Driver Behavior: Effects of an In-Vehicle Message System Interface
Authors: Jamson A. Hamish , Westerman Stephen J. , Hockey G. Robert J. , Carsten Oliver M. J.
Published: January 2005

As mobile office technology becomes more advanced, drivers have increased opportunity to process information "on the move." Although speech-based interfaces can minimize direct interference with driving, the cognitive demands associated with such systems may still cause distraction. We studied the effects on driving performance of an in-vehicle simulated "E-mail" message system; E-mails were either system controlled or driver controlled. A high-fidelity, fixed-base driving simulator was used to test 19 participants on a car-following task. Virtual traffic scenarios varying in driving demand. Drivers compensated for the secondary task by adopting longer headways but showed reduced anticipation of braking requirements and shorter time to collision. Drivers were also less reactive when processing E-mails, demonstrated by a reduction in steering wheel inputs. In most circumstances, there were advantages in providing drivers with control over when E-mails were opened. However, during periods without E-mail interaction in demanding traffic scenarios, drivers showed reduced braking anticipation. This may be a result of increased cognitive costs associated with the decision making process when using a driver-controlled interface when the task of scheduling E-mail acceptance is added to those of driving and E-mail response. Actual or potential applications of this research include the design of speech-based in-vehicle messaging systems.
Lessons From a Comparison of Work Domain Models: Representational Choices and Their Implications
Authors: Burns Catherine M. , Bisantz Ann M. , Roth Emilie M.
Published: January 2005

As methods in cognitive work analysis become more widely applied, questions regarding the impact of modeling choices and similarities in modeling efforts across projects and domains are increasingly relevant. However, no explicit comparison of models of similar systems has been reported. This paper compares independently developed work domain analysis (WDA) models of two command and control environments. Similarities in model content and the types of nodes included provide evidence that WDA techniques can capture fundamental elements regarding purposes and constraints. These points of agreement provide a common starting point for developing work domain representations of military command and control systems. The comparison also revealed differences between the models. Although differences in content reflected differences in scope of coverage and level of detail, other differences corresponded to more fundamental choices in modeling approach. These included the treatment of sensors, level of integration in the model, and representation of particular abstract constraints. Examination of these more fundamental differences pointed to important degrees of freedom in how to represent a WDA and clarified the implications of these modeling choices for guiding design. Actual or potential applications of this research include aiding analysts in making work domain modeling choices as well as producing work domain models of command and control environments.
The Apparent and Effective Dimensionality of Representations of Objects
Authors: Spence Ian
Published: January 2005

Information displays commonly use 2-D and 3-D objects even though the numbers represented are 1-D. This practice may be problematic because the psychophysical relation between perceived and physical magnitudes is generally nonlinear for areas and volumes. Nonetheless, this research shows that apparent 2-D and 3-D objects can produce linear psychophysical functions if only one dimension shows variation. Processing time increases with the number of dimensions in the objects that show variation, not with the apparent dimensionality. Indeed, when only one dimension showed variation, apparent 3-D objects were judged more quickly than were apparent 2-D or 1-D objects. These results present a challenge for computational models of size perception and have implications for the design of information displays. Actual or potential applications of this research include the design and use of statistical graphs and information displays; objects that display variation in more than one dimension should not be used to represent single (1-D) numerical variables if they are to be judged accurately and rapidly.
Predicting Practical Fitness to Drive in Drivers With Visual Field Defects Caused by Ocular Pathology
Authors: Coeckelbergh Tanja R. M. , Brouwer Wiebo H. , Cornelissen Frans W. , Kooijman Aart C.
Published: January 2005

Vision, viewing efficiency, visual attention, and on-road driving performance were assessed in 100 participants with central and/or peripheral visual field defects caused by ocular pathology. Driving was evaluated by the Dutch driving license authority making use of the protocol for investigating practical fitness to drive. A smaller percentage of participants with central visual field defects passed the on road driving test, in comparison with participants with peripheral or mild field defects. The predictive power of a model based on the current vision requirements for driving significantly increased when taking compensatory viewing efficiency into account. The results of the latter model were comparable to those of a model based on tests of visual attention and contrast sensitivity. Despite the increased explained variance of practical fitness to drive when taking higher-order visual functions into account, sensitivity and specificity remained quite low, limiting the use of these tests in identifying unfit drivers. Actual or potential applications of this research include the development of training programs to improve practical fitness to drive in drivers with visual field defects.
Tobacco Use and Cessation Among a Household-Based Sample of US Urban Men Who Have Sex With Men
Authors: Greenwood Gregory L. , Paul Jay P. , Pollack Lance M. , Binson Diane , Catania Joseph A. , Chang Jason , Humfleet Gary , Stall Ron
Published: January 2005

Objectives. We examined tobacco use and cessation among a probability sample of urban men who have sex with men (MSM) living in 4 large US cities.

Methods. Of the 2402 men who were eligible for follow-up from a previously recruited probability sample, 1780 (74%) completed tobacco surveys between January and December 1999.

Results. Current smoking rates were higher for urban MSM (31.4%; 95% confidence interval [CI]=28.6%, 34.3%) than for men in the general population (24.7%; 95% CI=21.2%, 28.2%). Among MSM, 27% were former smokers. A complex set of sociodemographic, tobacco-related, and other factors were associated with cessation.

Conclusions. Results support earlier reports that smoking rates are higher for MSM compared with men in the general population. Findings related to cessation underscore the need to target tobacco control efforts for MSM.
Gender Differences in Psychiatric Disorders at Juvenile Probation Intake
Authors: Wasserman Gail A. , McReynolds Larkin S. , Ko Susan J. , Katz Laura M. , Carpenter Jennifer R.
Published: January 2005

Objective. We identified gender differences in psychiatric disorders among youths at probation intake.

Methods. We measured disorders with the Voice Diagnostic Interview Schedule for Children among 991 randomly selected youths (200 girls) at probation intake in 8 Texas counties. Logistic regression analyses predicted diagnostic clusters by gender, adjusting for demographics and offense characteristics.

Results. Demographic and offense characteristics explained small but interpretable and specific variance in diagnostic profile. Girls’ rates of anxiety and affective disorders were higher than boys’ (odds ratios = 0.59 and 0.32, respectively). Girls with violent offenses, compared with other groups, were 3 to 5 times as likely to report anxiety disorders.

Conclusions. Among youths with conduct problems, girls demonstrated an elevated risk for co-occurring anxiety or affective disorder.
A Longitudinal Analysis of Unmet Need for Oral Treatment in a National Sample of Medical HIV Patients
Authors: Marcus Marvin , Maida Carl A. , Coulter Ian D. , Freed James R. , Der-Martirosian Claudia , Liu Honghu , Freed Benjamin A. , Guzmán-Becerra Norma , Andersen Ronald M.
Published: January 2005

This longitudinal study examines perceived unmet dental need in a nationally representative probability sample of HIV-infected persons in medical care. A logistic regression analysis modeled the relationship between unmet need and explanatory variables. We estimate that 40% of HIV/AIDS patients report an unmet need associated with being male, being unemployed, injecting drugs, being heterosexual, lacking dental insurance, and having less education. Disparities in unmet need are related to socioeconomic status rather than to disease stage or ethnicity.
Working While Ill as a Risk Factor for Serious Coronary Events: The Whitehall II Study
Authors: Kivimäki Mika , Head Jenny , Ferrie Jane E. , Hemingway Harry , Shipley Martin J. , Vahtera Jussi , Marmot Michael G.
Published: January 2005

Objectives. Although sick, some people take no time off work, a phenomenon called “sickness presenteeism.” This study examined the association between sickness presenteeism and incidence of serious coronary events.

Methods. The analyses were based on a cohort of 5071 male British civil servants without previous myocardial infarction. Baseline screening included measurements of health status and coronary risk factors. Absence records were assessed for the 3 years subsequent to baseline screening. The outcome of interest was incident nonfatal myocardial infarction or fatal coronary heart disease (mean length of follow-up=9.1 years).

Results. Seventeen percent of unhealthy employees took no absence during the 3-year follow-up. Their incidence of serious coronary events was twice as high as that of the unhealthy employees with moderate levels of sickness absenteeism (after adjustment for conventional risk factors, hazard ratio 1.97, 95% confidence interval=1.02, 3.83).

Conclusions. Employers and employees should be aware of the potential harmful effects caused by sickness presenteeism.
Infant Mortality and Income in 4 World Cities: New York, London, Paris, and Tokyo
Authors: Rodwin Victor G. , Neuberg Leland G.
Published: January 2005

Objectives. We investigated the association between average income or deprivation and infant mortality rate across neighborhoods of 4 world cities.

Methods. Using a maximum likelihood negative binomial regression model that controls for births, we analyzed data for 1988–1992 and 1993–1997.

Results. In Manhattan, for both periods, we found an association (.05% significance level) between income and infant mortality. In Tokyo, for both periods, and in Paris and London for period 1, we found none (5% significance level). For period 2, the association just missed statistical significance for Paris, whereas for London it was significant (5% level).

Conclusions. In stark contrast to Tokyo, Paris, and London, the association of income and infant mortality rate was strongly evident in Manhattan.
Effects of Snowfalls on Motor Vehicle Collisions, Injuries, and Fatalities
Authors: Eisenberg Daniel , Warner Kenneth E.
Published: January 2005

Objectives. We estimated the effects of snowfalls on US traffic crash rates between 1975 and 2000.

Methods. We linked all recorded fatal crashes (1.4 million) for the 48 contiguous states from 1975 through 2000 to daily state weather data. For a subsample including 17 states during the 1990s, we also linked all recorded property-damage-only crashes (22.9 million) and nonfatal-injury crashes (13.5 million) to daily weather data. Employing negative binomial regressions, we investigated the effects of snowfall on crash counts. Fixed effects and other controls were included to address potential confounders.

Results. Snow days had fewer fatal crashes than dry days (incidence rate ratio [IRR] = 0.93; 95% confidence interval [CI] = 0.90, 0.97), but more nonfatal-injury crashes (IRR = 1.23; 95% CI = 1.18, 1.29) and property-damage-only crashes (IRR=1.45; 95% CI=1.38, 1.52). The first snowy day of the year was substantially more dangerous than other snow days in terms of fatalities (IRR = 1.14; 95% CI=1.08, 1.21), particularly for elderly drivers (IRR=1.34; 95% CI=1.23, 1.50).

Conclusions. The toll of snow-related crashes is substantial. Our results may help estimate the potential benefits of safety innovations currently proposed by meteorology and traffic safety experts.
Interpolation inh‐Version Finite Element Spaces
Authors: Apel Thomas
Published: January 2005

Interpolation operators associate with a function an element from a finite element space. The difference between the two functions is calledinterpolation error. Estimates of the interpolation error are used for a priori and a posteriori estimation of the discretization error of finite element methods. For a priori error estimates, one can often use thenodal interpolant. To get optimal error bounds, the maximum available regularity of the solution has to be used. The situation is different for a posteriori error estimates. For the investigation of residual‐type error estimators, local interpolation error estimates for functions from the Sobolev spaceW1, 2(Ω) are needed. Such estimates can be obtained for many finite elements only forquasi‐interpolation operators, where point values of functions or derivatives are replaced in the definition of the interpolation operators by certain averaged values.

This paper gives an overview of different interpolation operators and their error estimates. The discussion restricts theh‐version of the finite element method, but it includes interpolation on the basis of triangular/tetrahedral and quadrilateral/hexahedral meshes, affine and nonaffine elements, isotropic and anisotropic elements, and Lagrangian and other elements.
Coupling of Boundary Element Methods and Finite Element Methods
Authors: Stephan Ernst P.
Published: January 2005

For the numerical treatment of elliptic boundary value problems, the coupling of boundary element methods and finite element methods is widely used. Usually, the FEM is applied in a bounded subdomain, whereas the BEM subdomain may be unbounded, but without inhomogeneous or nonlinear material behavior. This chapter gives a survey of FE/BE coupling for elliptic interface problems with emphasis on mathematics. We concentrate on the symmetric coupling method because of its general applicability and give a priori and a posteriori error estimates. Further, we address implementational aspects such as suitable preconditioning for appropriate solvers of the Galerkin equations. As new developments, we consider a least squares coupling method with first‐order systems in the FEM domain and consider both primal and dual FE/BE coupling methods for interface problems with Signorini contact condition. Besides standard formulations, mixed FEM formulations are also considered. Applications in elasticity are discussed. We present proofs of essential theorems because we feel that these proofs are essential for understanding the mathematical aspects. We also present illustrative numerical examples and provide a list of references to the current literature.
Elastoplastic and Viscoplastic Deformations in Solids and Structures
Authors: Armero F.
Published: January 2005

This chapter presents a summary of some recent developments in the formulation and the numerical integration of elastoplastic and viscoplastic models of solids and structures. A brief description of the constitutive relations in these models in both the infinitesimal and finite deformation ranges is presented first. A key aspect of the elastoplastic models is the yield condition constraining the stress state to the so‐calledelastic domain, with the viscoplastic models resulting in a regularization of this unilateral constraint. This constrained character of the problem leads naturally to the traditional return‐mapping algorithms used in the numerical integration of the local plastic evolution equations. The resulting discrete equations correspond to the so‐calledclosest‐point projectionequations by which an elastic trial state is projected onto the elastic domain. The mathematical structure of these equations is studied to obtain efficient numerical techniques for their solution. In particular, the rich variational structure of the associated problem is investigated in detail. Primal and dual variational formulations are derived for the elastoplastic and viscoplastic models. Both lead to unilaterally constrained elastoplastic problems reflecting the underlying constrained physical system. Augmented Lagrangian extensions of these formulations resulting in unconstrained forms of the discrete equations, both in their primal and dual versions, are also explored. The different numerical algorithms associated with each of these formulations, referred generically as closest‐point projection (CPPM) algorithms, are presented in detail for a general plastic model, not necessarily associated.
Shakedown and Safety Assessment
Authors: Zouain Nestor
Published: January 2005

The main subjects of this chapter are the variational formulations for the computation of a safety factor in shakedown analysis, the numerical procedures available to implement this analysis, and an overview on the wide field of applications and conceptual extensions.

In structural engineering and solid mechanics, the wordshakedown, introduced in the 1940s by W. Prager, became, since then, synonymous with elastic adaptation in the presence of variable loadings, a safe stabilized phenomenon, often due to some limited plastic deformation (or equivalently, due to the residual stress distribution associated with inelastic strains).

Concerning the failure analysis of ductile structures, the termsalternating plasticityandincremental collapse, besidesplastic collapse, are also widely used to identify failure modes under variable loadings. A structure undergoesalternating plasticitywhen the fluctuating loading program produces, after any arbitrarily large time, some plastic deformation as well as a subsequent vanishing of the net plastic deformation. This induces failure due to low‐cycle fatigue. Likewise, the structure fails byincremental collapsewhen plastic deformations accumulate in the form of a compatible strain distribution that leads to excessive inelastic deformation.

Shakedown analysis allows working under the realistic assumption that only the range of variable loadings is known, unlike the usual prescription of a particular loading history. That is, we deal withdirect methodsthat are based solely on the knowledge of a range of load variations (or a reference loading, in limit analysis) in this chapter. It is worth emphasizing that the differences between incremental and direct methods go beyond the computational advantages frequently obtained with the latter ones. In fact, the fundamental questions about whether or not critical loads or cycles do exist, independently from loading histories, can only be answered by the theories of direct methods.

The mathematical foundations of shakedown theory strongly rest on optimization theory and the related areas of convex analysis and mathematical programming. The present chapter contains simplified derivations of the statical, kinematical, and mixed variational principles of shakedown theory by means of the basic techniques of convex analysis. Moreover, numerical procedures suitable to solve the shakedown analysis problem are discussed here in the framework of mathematical programming techniques combined with common procedures in the field of finite element methods.

Applications in fundamental examples are then presented, namely, (a) a restrained block under thermo‐mechanical loadings, (b) the classical Bree problem of a tube under variable pressure and temperature, with a more realistic model and including an exact solution, (c) a plate with a circular hole subjected to variable tractions, and (d) a plate with simulated imperfections showing critical mechanisms with strongly localized deformations.
Computational Contact Mechanics
Authors: Wriggers P. , Zavarise G.
Published: January 2005

This paper describes modern techniques used to solve contact problems within Computational Mechanics. On the basis of a continuum description of contact, the mathematical structure of the contact formulation for finite element methods is derived. Emphasis is also placed on the constitutive behavior at the contact interface for normal and tangential (frictional) contact. Furthermore, different discretization schemes currently applied to solve engineering problems are formulated for small and finite strain problems. These include isoparametric interpolations, node‐to‐segment discretizations and also mortar and Nitsche techniques. Furthermore, several algorithms related to spatial contact search and fulfillment of the inequality constraints at the contact interface are discussed. Here, especially the penalty and Lagrange multiplier schemes are considered and also SQP‐ and linear‐programming methods are reviewed.
Computational Modeling of Forming Processes
Authors: Perić D. , Owen D. R. J.
Published: January 2005

This chapter discusses some of the relevant computational strategies that permit the simulation of industrial scale forming processes within realistic time frames and computational resources. The need for rigorous consideration of both theoretical and algorithmic issues is emphasized, particularly in relation to the computational treatment of finite strain elastoplastic (viscoplastic) deformation, the modeling of frictional contact conditions and element technology capable of dealing with plastic incompressibility. Practically important aspects such as adaptive mesh refinement procedures are discussed and attention is given to choice of appropriate error indicators for inelastic materials and the transfer of solution parameters between successive meshes. The role of explicit solution techniques in the simulation of large‐scale forming processes is also discussed.
Multifield Problems
Authors: Schrefler B. A.
Published: January 2005

This chapter deals with multifield problems with overlapping domains. A review of a series of typical problems belonging to this filed is first presented where examples of up to six overlapping fields are shown. Then the most popular solution procedures are discussed. They are either the monolithic method or methods involving some matrix partitioning. These methods are illustrated on selected model problems. The respective numerical properties and connected problems are discussed and examples are shown.
Vortex Methods
Authors: Winckelmans G. S.
Published: January 2005

Vortex methods are presented, from the fundamentals to the advanced subjects. These methods are well suited to simulating unsteady, convection‐dominated, flows (inviscid and viscous). The spectrum of applicability is thus quite large. Examples are presented in incompressible flows (unbounded flows and bluff‐body flows) and in combustion.
Incompressible Viscous Flows
Authors: Rannacher Rolf
Published: January 2005

In this article, we describe some approaches to the efficient numerical computation of viscous incompressible flows governed by the Navier–Stokes equations. We concentrate onlaminarflows, stationary as well as nonstationary, for Reynolds numbers of moderate size, and in general domains. The emphasis is on spatial discretization by the finite element method. We discuss the treatment of the incompressibility constraint, the time‐stepping process, techniques of error control and mesh adaptation and the solution of the resulting indefinite algebraic equations.
Blood Flow
Authors: Taylor Charles A.
Published: January 2005

Computational methods can be used to simulate blood flow and vessel dynamics, test hypotheses of disease formation under controlled conditions, and evaluate devices that have not yet been built and treatments that have not yet been implemented. In this chapter, we review computational methods for quantifying blood flow velocity and pressure fields in human arteries. These methods include numerical solutions used to compute blood flow based on lumped parameter, linear, and nonlinear one‐dimensional and three‐dimensional models of blood flow. Computational models can be idealized or constructed from imaging data and applications include improved design of surgical procedures and patient‐specific preoperative planning.
Can specific deficits in executive functioning explain the behavioral characteristics of CHARGE syndrome: A case study
Authors: Nicholas Jude
Published: January 2005

I present the case of a 12‐year‐old girl diagnosed with CHARGE syndrome. As an infant she had shown typical characteristics of CHARGE. Neuroimaging revealed asymmetrical ventriculomegaly. Both her teacher and parents reported academic and psychosocial problems. Neuropsychological assessment revealed significant executive dysfunction, including attention difficulties. We discuss the possible association between executive deficits and school and psychosocial problems. This case also highlights the importance of evaluating executive function in children with CHARGE, which is particularly useful in efficiently identifying needs for direct intervention. © 2005 Wiley‐Liss, Inc.
Speculations on the pathogenesis of CHARGE syndrome
Authors: Williams Marc S.
Published: January 2005

To be seriously considered, a theory about the pathogenesis of a multiple congenital anomaly syndrome should meet three criteria: (1) it should explain all of the anomalies associated with the syndrome; (2) it should explain why certain anomalies are not associated with the syndrome; and (3) it should predict anomalies that could be associated with the syndrome, but have not yet been described. The theory must eventually pass the ultimate test, that is, molecular confirmation of the proposed mechanism. Several theories about the pathogenesis of CHARGE syndrome have been proposed, but none of these meet the three criteria stated above. In this study, the author proposes that CHARGE syndrome is due to a disruption of mesenchymal–epithelial interaction (epithelial includes ectoderm and endoderm). The theory is tested against the major, minor, and occasional anomalies that are used to make the clinical diagnosis of CHARGE syndrome. Review of the known embryology of the organs and tissues involved in CHARGE syndrome confirms that mesenchymal–epithelial interactions are necessary for proper formation of these organs and tissues. The presence of limb anomalies in approximately one‐third of CHARGE syndrome patients fulfills criteria #3 above, in that limb anomalies were not felt to be a part of CHARGE syndrome until relatively recently. It is known that some patients with chromosomal abnormalities have a phenotype that overlaps with CHARGE syndrome. Given that critical developmental pathways must be robust and redundant in order to minimize errors, it may be that disruption of more than one gene is necessary to generate the CHARGE phenotype, as has been proposed for the holoprosencephaly sequence. Mutations and deletions of CHD7 have recently been identified as causing CHARGE syndrome in more than 50% of tested patients. Given this gene classes' putative role as a general controller of developmental gene expression as well as mesodermal patterning, it would fit the hypothesized mechanisms discussed in the study. © 2005 Wiley‐Liss, Inc.
Methylation: Its role in the environmental mobility of heavy elements
Authors: Thayer John S
Published: January 2005

Formation of bonds between methyl groups and heavy elements (metals or metalloids) alters various physical properties such as solubility or volatility. This alteration enhances the mobility of the heavy metal and can play a major role in the environmental cycles for these elements. Environmental methylation has been established as a major factor in the environmental movement of mercury and arsenic, and very probably affects other elements similarly. Two methylating agents (methylcobalamin and methyl iodide) have been found to mobilize metals out of water‐insoluble compounds and/or anoxic sediments. These two compounds react with quite different substrates, but the kinetics of the resulting dissolutions follow virtually identical patterns. These reactions proceed through formation of a methylated intermediate on the substrate surface, followed by movement of the heavy element out of the solid lattice into the surrounding solution.
Model studies of trialkyltin–protein interactions: 13C NMR analysis of solution equilibria of the complex between trimethyltin and methyl N‐benzoyl‐l‐leucyl‐l‐histidinate
Authors: Harrison Philip G , Sharpe Nelson W
Published: January 2005

13C NMR spectra for the 1:1 complex between methyl N‐benzoyl‐l‐leucyl‐l‐histidinate and the trimethyltin moiety in d‐chloroform (CDC13), d4‐methanol (CD3OD) dimethyl sulphoxide (DMSO) and d6‐DMSO/H2O solvents are reported, and contrasted with those for the free ligand. The spectra are interpreted in terms of a variety of solution equilibria illustrating the nature of the interaction between the trimethyltin species and primarily the imidazole ring of the histidine residue. Evidence for the preferential stability of pentacoordinate solution structures about tin is presented.
An international intercalibration for methylmercury in biological tissue
Authors: Thibaud Y. , Cossa D.
Published: January 2005

An intercalibration exercise between 13 laboratories from seven countries was conducted for comparing the methylmercury measurement techniques for marine biological tissues. Analyses have been conducted on two sets of samples: a fish muscle and a mussel soft tissue. Most of the participating laboratories performed six replicate analyses, allowing statistical comparisons. Various analytical techniques have been used, including cold vapour atomic absorption spectrophotometry (CVAA), electron capture gas liquid chromatography (GCEC), neutron activation (NAA), and inductively coupled plasma–isotopic dilution mass spectrometry (ICPIDMS). All of these methods offer similar results. They allow us to define consensus values which seem good estimates of the real concentrations. In addition the results show, for most of the participating laboratories, good accuracy and precision in the determination.
A comparative study on acute toxicity of methylarsonic acid, dimethylarsinic acid and trimethylarsine oxide in mice
Authors: Kaise Toshikazu , Yamauchi Hiroshi , Horiguchi Yoshiya , Tani Takayuki , Watanabe Shigenobu , Hirayama Teruhisa , Fukui Shozo
Published: January 2005

The acute toxicity of methylarsonic acid, CH3AsO(OH)2 (MAA), dimethylarsininc acid, (CH3)2AsO(OH) (DMAA), and trimethylarsine oxide, (CH3)3AsO (TMAO), were examined in mice with oral administration.

The LD50 values of MAA, DMAA and TMAO were 1.8, 1.2 and 10.6 g kg−1 respectively. The toxicity of MAA and DMAA was very much lower than that for inorganic arsenic compounds. It was shown that TMAO has a similar acute toxicity to arsenobetaine. On the other hand, when the mice were administered 14.4 g kg−1 of TMAO once only orally, a garlic‐like odor (trimethylarsine, (CH3)3As) was definitely detectable in the exhalation of the animals by the human olfactory sense within about a few minutes.
Changes in fungal and bacterial populations in soil treated with two triorganotin(IV) compounds
Authors: Kuthubutheen A J , Wickneswari R , Kumar Das V G
Published: January 2005

The effects of two triorganotin(IV) compounds, diphenylbutyltin bromide (Ph2BuSnBr) and triphenyltin chloride·triphenylphosphine oxide (Ph3SnCl·Ph3PO), on soil bacterial and fungal populations were compared with that of Thiram and the commercial triorganotin fungicide ‘Brestan’ (triphenyltin acetate, Ph3SnOAc). Soil fungal populations were reduced most by Thiram, then by Ph3SnCl·Ph3PO, Ph2BuSnBr and Ph3SnOAc, in that order. Following the application of the compounds, there was a marked increase in the bacterial population in soil, the increase being greatest with Thiram and least with Ph3SnCl·Ph3PO. The triorganotin(IV) compounds were less harmful to soil fungi than Thiram. In Thiram‐treated soil, recolonization was slower than in soil treated with the triorganotin(IV) compounds. More species of fungi were tolerant to and persisted after application of the triorganotin(IV) compounds compared with Thiram. Among the fungi that were tolerant to the triorganotin(IV) compounds were cellulolytic species such as Trichoderma.
The degradation of triphenyltin biocides in neoprene‐based elastomeric marine antifouling coatings: 119mSn Mössbauer and chemical speciation studies
Authors: Allen David W , Brooks John S , Bailey Stephen
Published: January 2005

The fate of a series of triphenyltin biocides on incorporation into neoprene elastomers has been studied by 119mSn Mössbauer spectroscopy, together with supporting chemical derivatization techniques. It is shown that triphenyltin compounds undergo drastic degradation on incorporation into neoprene, suffering cleavage of phenyl–tin bonds to give a mixture of products in which all stages of dephenylation are present, including stannic chloride. This degradation occurs not only in elastomers cured at 150°C, but also in room temperature solvent‐cast samples.