bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of continuum breakdown on hypersonic aerothermodynamics
Authors: Lofthouse Andrew J. , Boyd Iain D. , Wright Michael J.
Published: March 2007

Hypersonic vehicles experience different flow regimes during flight due to changes in atmospheric density. Hybrid continuum-particle methods, based on computational fluid dynamics (CFD) and direct simulation Monte Carlo (DSMC) methods, are being developed to simulate the flow in different hypersonic regimes. These methods use a breakdown parameter to determine regions of the flow where the CFD physics are no longer valid. The current study investigates the effect of continuum breakdown on surface aerothermodynamic properties (pressure, shear stress, and heat transfer rate) of a cylinder in a Mach 10 flow of argon gas for several different flow regimes, from the continuum to a rarefied gas. CFD and DSMC solutions are obtained at each flow condition. Total drag predictions differ by less than 1% for a continuum flow while CFD predicts a 26% higher drag than DSMC for a rarefied flow. Peak heat transfer rate differences range from less than 1% for a continuum flow to more than 32% for a rarefied flow, again with CFD predicting the higher value. Differences in drag and heat transfer are expected to decrease with the use of velocity slip and temperature jump boundary conditions with the CFD method.
Correlation between structural defects and properties in large La–Sr–Mn–O single crystals
Authors: Monot-Laffez Isabelle , Dominiczak Maguy , Giovannelli Fabien , Ruyter Antoine , Rossell Marta D. , Van Tendeloo Gustaaf
Published: March 2007

Structural, magnetic, and electrical properties of La0.8Sr0.2MnO3 single crystals grown by the floating zone technique have been investigated using x-ray Laue diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy and magnetic force microscopy (MFM) magnetization and resistivity measurements. The aim of this work was to identify growth defects and their possible correlation with the transport properties or magnetic self-organization. The analysis by x-ray Laue diffraction and SEM reveals large single crystal structure without any extended microdefects and with a homogeneous composition. TEM observations show nanometric defects present only in the central part of the grown rod and allow to identify these defects as nanocracks resulting from a high stress gradient during the growth. Transport measurements indicate that there is an effect of the variation of oxygen content but the conducting behavior between 300 and 5K is not affected by the presence of the nanocracks. Moreover, the magnetic behavior of the single crystal, observed by MFM, shows that the magnetic ordering of the domains is strongly connected to the structural properties and the amount of defects.
Terahertz microcavity lasers with subwavelength mode volumes and thresholds in the milliampere range
Authors: Chassagneux Y. , Palomo J. , Colombelli R. , Dhillon S. , Sirtori C. , Beere H. , Alton J. , Ritchie D.
Published: March 2007

The authors demonstrate terahertz microcavity lasers with ultralow current thresholds (Ith≈4mA) and with reduced mode volumes of ≈0.7(λeffective)3, i.e., less than one cubic wavelength. A double metal waveguide with reduced active core thickness (5.82μm) is used to achieve confinement in the vertical direction, without compromising the laser performances. Confinement in the longitudinal direction is obtained using microdisk resonators. The guiding properties of surface plasmons are exploited to guide the mode with the metal contact. This makes the use of a resonator with vertical and smooth sidewalls unnecessary. The emission wavelength is λ≈114μm. The devices lase up to 70K in pulsed mode, and they achieve continuous-wave operation up to 60K.
The NHERF1 PDZ2 Domain Regulates PKA–RhoA–p38-mediated NHE1 Activation and Invasion in Breast Tumor Cells
Authors: Cardone Rosa A. , Bellizzi Antonia , Busco Giovanni , Weinman Edward J. , Dell'Aquila Maria E. , Casavola Valeria , Azzariti Amalia , Mangia Anita , Paradiso Angelo , Reshkin Stephan J.
Published: March 2007

Understanding the signal transduction systems governing invasion is fundamental for the design of therapeutic strategies against metastasis. Na+/H+exchanger regulatory factor (NHERF1) is a postsynaptic density 95/disc-large/zona occludens (PDZ) domain-containing protein that recruits membrane receptors/transporters and cytoplasmic signaling proteins into functional complexes. NHERF1 expression is altered in breast cancer, but its effective role in mammary carcinogenesis remains undefined. We report here that NHERF1 overexpression in human breast tumor biopsies is associated with metastatic progression, poor prognosis, and hypoxia-inducible factor-1α expression. In cultured tumor cells, hypoxia and serum deprivation increase NHERF1 expression, promote the formation of leading-edge pseudopodia, and redistribute NHERF1 to these pseudopodia. This pseudopodial localization of NHERF1 was verified in breast biopsies and in three-dimensional Matrigel culture. Furthermore, serum deprivation and hypoxia stimulate the Na+/H+exchanger, invasion, and activate a protein kinase A (PKA)-gated RhoA/p38 invasion signal module. Significantly, NHERF1 overexpression was sufficient to induce these morphological and functional changes, and it potentiated their induction by serum deprivation. Functional experiments with truncated and binding groove-mutated PDZ domain constructs demonstrated that NHERF1 regulates these processes through its PDZ2 domain. We conclude that NHERF1 overexpression enhances the invasive phenotype in breast cancer cells, both alone and in synergy with exposure to the tumor microenvironment, via the coordination of PKA-gated RhoA/p38 signaling.
PhyloGena—a user-friendly system for automated phylogenetic annotation of unknown sequences
Authors: Hanekamp Kristian , Bohnebeck Uta , Beszteri Bánk , Valentin Klaus
Published: March 2007

Motivation: Phylogenomic approaches towards functional and evolutionary annotation of unknown sequences have been suggested to be superior to those based only on pairwise local alignments. User-friendly software tools making the advantages of phylogenetic annotation available for the ever widening range of bioinformatically uninitiated biologists involved in genome/EST annotation projects are, however, not available. We were particularly confronted with this issue in the annotation of sequences from different groups of complex algae originating from secondary endosymbioses, where the identification of the phylogenetic origin of genes is often more problematic than in taxa well represented in the databases (e.g. animals, plants or fungi).

Results: We present a flexible pipeline with a user-friendly, interactive graphical user interface running on desktop computers that automatically performs a basic local alignment search tool (BLAST) search of query sequences, selects a representative subset of them, then creates a multiple alignment from the selected sequences, and finally computes a phylogenetic tree. The pipeline, named PhyloGena, uses public domain software for all standard bioinformatics tasks (similarity search, multiple alignment, and phylogenetic reconstruction). As the major technological innovation, selection of a meaningful subset of BLAST hits was implemented using logic programing, mimicing the selection procedure (BLAST tables, multiple alignments and phylogenetic trees) are displayed graphically, allowing the user to interact with the pipeline and deduce the function and phylogenetic origin of the query. PhyloGena thus makes phylogenomic annotation available also for those biologists without access to large computing facilities and with little informatics background. Although phylogenetic annotation is particularly useful when working with composite genomes (e.g. from complex algae), PhyloGena can be helpful in expressed sequence tag and genome annotation also in other organisms.

Availability: PhyloGena (executables for LINUX and Windows 2000/XP as well as source code) is available by anonymous ftp from http://www.awi.de/en/phylogena

Contact: kvalentin@awi-bremerhaven.de
Improving metabolic flux estimation via evolutionary optimization for convex solution space
Authors: Chen Jiusheng , Zheng Haoran , Liu Haiyan , Niu Junqing , Liu Jianping , Shen Tie , Rui Bin , Shi Yunyu
Published: March 2007

Motivation: Flux estimation by using 13 C-labeling pattern information of metabolites is currently the only method that can give accurate, detailed quantification of all intracellular fluxes in the central metabolism of a microorganism. In essence, it corresponds to a constrained optimization problem which minimizes a weighted distance between measured and simulated results. Characteristics, such as existence of multiple local minima, non-linear and non-differentiable make this problem a special difficulty.

Results: In the present work, we propose an evolutionary-based global optimization algorithm taking advantage of the convex feature of the problem's solution space. Based on the characteristics of convex spaces, specialized initial population and evolutionary operators are designed to solve 13C-based metabolic flux estimation problem robustly and efficiently. The algorithm was applied to estimate the central metabolic fluxes in Escherichia coli and compared with conventional optimization technique. Experimental results illustrated that our algorithm is capable of achieving fast convergence to good near-optima and maintaining the robust nature of evolutionary algorithms at the same time.

Availability: Available from the authors upon request.

Contact:  hrzheng@ustc.edu.cn

Supplementary information: Colour versions of the figure are available online as a part of the Supplementary data.
Phylogenetic exploration of bacterial genomic rearrangements
Authors: Fremez Romain , Faraut Thomas , Fichant Gwennaele , Gouzy Jérôme , Quentin Yves
Published: March 2007

Summary: We present a graphical tool dedicated to the exploration of bacterial genome rearrangements. The principle of this exploration relies on the reconstruction of ancestral genomes at each internal node of a gene-order-based phylogenetic tree. This tool allows the selection of internal nodes to visualize the rearrangements between the inferred chromosome of this node and its direct descendant on the tree.

Availability: PEGR is available at the Genopole Toulouse Bioinformatics platform.

Supplementary information: Online supplementary data are available at PEGR web site: http://bioinfo.genopole-toulouse.prd.fr/pegr.
Culture ofDrosophila: The Laboratory Setup
Authors: Ashburner Michael , Roote John
Published: March 2007

INTRODUCTION

Since its introduction to experimental biology more than 90 years ago,Drosophila melanogasterhas proved to be an easily cultured and robust laboratory animal. Although culture techniques and the ways in which flies are handled have changed over the years, if he were to enter a fly room today, T.H. Morgan would clearly recognize what is being done, and why. This article provides the basic methods for the laboratory culture ofD. melanogaster. The intelligent culture ofDrosophilarequires a basic understanding of the life cycle of this fly. For this reason, we begin by describing the life cycle ofDrosophilaand then present information for setting up a fly laboratory.
Protein Arrays: Preparation of Microscope Slides
Authors: MacBeath Gavin
Published: March 2007

INTRODUCTION

This protocol describes the preparation of glass microscope slides with two particularly useful substrates: aldehyde and BSA-NHS. On aldehyde slides, amines on the proteins form a Schiff base with the aldehydes on the slide. BSA-NHS (bovine serum albumin-N-hydroxysuccinimide) slides contain a layer of BSA molecules that are chemically activated for covalent attachment of proteins to the slide. In this case, amines on the proteins of interest form amide or urea bonds with the activated carboxylates or activated amines of the BSA, respectively.
Protein Arrays: Sandwich Approach for Analyzing Complex Solutions
Authors: MacBeath Gavin
Published: March 2007

INTRODUCTION

Protein arrays can be used to quantitate the abundance and modification states of proteins in complex mixtures. For this application, it is necessary to array-capture reagents, such as antibodies, on the slides and then use these molecules to specifically capture their cognate antigens from solution. The investigator has a choice in either labeling the proteins that are under study or detecting the captured proteins by an indirect labeling method. In the latter case, which is detailed in this protocol, each protein is captured by one antibody (or other capture reagent) and then detected in a second step with a second reagent. The second reagent, which in this case is also an antibody, recognizes the protein at a site that does not overlap with the recognition site of the capture reagent. In this sandwich approach, the second reagent is labeled and so provides the signal. The advantage of this approach is that it does not require labeling the proteins themselves. Moreover, additional specificity is gained by using two different reagents for each protein. The disadvantage, however, is that it is more difficult to assemble matched pairs of antibodies for each protein of interest.
General Method for MALDI-MS Analysis of Proteins and Peptides
Authors: Frecklington David
Published: March 2007

INTRODUCTION

For MALDI-TOF-MS analysis of proteins and peptides, samples are cocrystallized with an excess of organic matrix that absorbs at a specific wavelength (usually, UV337nm). Typically, sinapinic acid (SA) is the matrix of choice for large proteins, whereas α-cyano-4-hydroxy-cinnamic acid (HCCA) is the preferred matrix for peptide mapping. Following a short laser pulse, analytes are protonated and desorbed into the gas phase, and their m/z values are determined in a TOF mass analyzer. Mass accuracy determinations vary from ±0.01% to 0.1% depending on the sample preparation technique and the method used for mass calibration.
Cleavage of Asn-Gly Bonds by Hydroxylamine: Figure 1.
Authors: Simpson Richard J.
Published: March 2007

INTRODUCTION

Selective cleavage of Asn-Gly bonds in proteins by hydroxylamine generates a relatively small number of large peptide fragments. This protocol describes a procedure for performing Asn-Gly bond cleavage in solution.
Performic Acid Oxidation of Proteins
Authors: Simpson Richard J.
Published: March 2007

INTRODUCTION

Disulfide bond cleavage is a prerequisite to many peptide-mapping strategies. It facilitates protein unfolding and thus optimizes proteolytic digestion. It also simplifies the interpretation of peptide maps by removing possible peptide fragment(s) in the mixture that are held together by disulfide bonds. This protocol describes the performic acid oxidation method for cleaving disulfide bonds. It is convenient for determining the combined cysteine and cystine content and the total methionine content of a protein.
Maintaining a Population of Drosophila
Authors: Sisson John Charles
Published: March 2007

INTRODUCTION

The Drosophila embryo is a superb source of proteins for studies aimed at characterizing a variety of cellular functions, including replication, transcription, translation, signal transduction, and the functions of the extracellular matrix and the cytoskeleton. The success of these studies requires the efficient production of gram quantities of embryos by large populations of adult flies. This protocol outlines a simple and efficient method for maintaining a population of Drosophila.
In Vitro Transcription Using Drosophila Nuclear Extracts
Authors: Pazin Michael J.
Published: March 2007

INTRODUCTION

Drosophila nuclear extracts are often used in gene expression studies. This protocol describes RNA polymerase II transcription in vitro using a Drosophila embryonic nuclear extract called soluble nuclear fraction (SNF). Transcription and RNA purification are followed by detection of the transcripts by primer extension with reverse transcriptase and a labeled oligonucleotide.
Preparation of Membrane Proteins from Drosophila Embryos
Authors: Zhang Claire X. , Hsieh Tao-shih
Published: March 2007

INTRODUCTION

Drosophila embryos provide a unique system for the study of membrane proteins because of an extensive database in both genetics and biochemistry. Drosophila early embryos have an extraordinary peak in membrane biogenesis with a 23-fold increase in membrane area over ~45 minutes. This protocol describes purification of Drosophila membranes using equilibrium sedimentation in a sucrose density step gradient (0.5 M, 2.0 M, 2.5 M). It also includes two methods to determine the membrane association of a protein of interest: (1) alkaline wash and (2) Triton X-114 phase separation.
Culturing Large Populations of Drosophila for Protein Biochemistry
Authors: Sisson John Charles
Published: March 2007

INTRODUCTION

The Drosophila embryo is a superb source of proteins for studies aimed at characterizing a variety of cellular functions, including replication, transcription, translation, signal transduction, and the functions of the extracellular matrix and the cytoskeleton. The success of these studies is dependent upon the maintenance of an efficient laboratory fly facility. This article outlines the basic requirements for maintaining Drosophila in large or small laboratories.
An integrated model for the effect of budesonide on ACTH and cortisol in healthy volunteers
Authors: Lönnebo Anna , Grahnén Anders , Karlsson Mats O.
Published: March 2007

What is already known about this subject

• The functionality of the HPA axis through cortisol production has been the subject for several investigations.

• Modelling of cortisol production has been described by endogenous substance models utilizing a combination of indirect response functions and sum of cosine functions.

• The effect of glucocorticoid drugs on cortisol production has been investigated using these models.

What this study adds

• Previous investigations (models) have not primarily considered the combined action of ACTH and cortisol.

• Since ACTH drives cortisol production we adopted, for our modelling, the same approach as previous investigations but we distinguished between two types of models for the production of cortisol (driven by ACTH), one being the sum of cosine functions, the other being described by surges.

• The presented surge‐based model can serve as a tool for further understanding of the HPA axis and may also prove useful in the development of drugs interacting with the axis.

Aims

Budesonide, a glucocorticosteroid, is used as a first‐line treatment for asthma. The aim of the study was to develop a PK/PD model for the effect of budesonide on ACTH and cortisol.

Methods

The modelling data were generated by conducting a single‐blind, randomized, placebo‐controlled cross‐over study. Ten healthy volunteers inhaled placebo (Placebo Turbohaler) and 1600 µg budesonide (Pulmicort Turbohaler), with a wash‐out period of 7 days between treatments. Baseline concentrations of cortisol and ACTH were measured after placebo treatment and concentrations of cortisol, ACTH and budesonide were assessed after budesonide treatment. A one‐compartment disposition model was used for budesonide disposition. Based on indirect response models, two types of models, distinguishing between production driven by a sum of cosine functions and production driven by surges, were used in parallel to describe the data.

Results

The surge‐based approach was the most appropriate, based on goodness‐of‐fit, objective function values and number of parameters. The surge‐based model that integrated both ACTH and cortisol data was chosen as the final model. The estimated half‐lives of endogenous ACTH and cortisol were 9 and 113 min, respectively. The budesonide and ACTH concentrations producing 50% of the maximal response (IC50 and A50) were 0.325 µg l−1 and 4.96 pmol l−1.

Conclusions

The present PK/PD model of the effect of budesonide on ACTH and cortisol can serve as a tool for further understanding of the hypothalamic‐pituitary‐adrenal (HPA) axis and be useful in the development of drugs interacting with the axis.
The proteasome inhibitors bortezomib and PR‐171 have antiproliferative and proapoptotic effects on primary human acute myeloid leukaemia cells
Authors: Stapnes Camilla , Døskeland Anne P. , Hatfield Kimberley , Ersvær Elisabeth , Ryningen Anita , Lorens James B. , Gjertsen Bjørn Tore , Bruserud Øystein
Published: March 2007

Proteasome inhibitors represent a new class of antineoplastic drugs that are considered in the treatment of haematological malignancies. We compared the effects of the reversible proteasome inhibitor bortezomib (Velcade®) and the epoxomicin derivative PR‐171, an irreversible inhibitor, on primary human acute myeloid leukaemia (AML) cells. Both drugs inhibited autocrine‐ and cytokine‐dependent proliferation of primary AML blasts when tested at nanomolar levels (0·1–100 nmol/l). The antiproliferative effect was independent of basal chymotrypsin‐like proteasome activity (showing a 20‐fold variation between patients), genetic abnormalities, morphological differentiation and CD34 expression when testing a large group of consecutive patients (n = 54). The effect was retained in cocultures with bone marrow stromal cells. In addition, both drugs enhanced apoptosis. The effect of PR‐171 could be detected at lower concentrations than for bortezomib, especially when testing the influence on clonogenic AML cell proliferation. Both drugs had divergent effects on AML cells’ constitutive cytokine release. Furthermore, both drugs caused a decrease in proliferation and viability when tested in combination with idarubicin or cytarabine. An antiproliferative effect on primary human acute lymphoblastic leukaemia cells was also detected. We conclude that nanomolar levels of the proteasome inhibitors tested had dose‐dependent antiproliferative and proapoptotic effects on primary AML cells in vitro.
Constraints on recovery: using molecular methods to study connectivity of aquatic biota in rivers and streams
Authors: HUGHES JANE M.
Published: March 2007

1. The ‘Field of Dreams Hypothesis’ states ‘if we build it, they will come’, referring to the assumption that if habitats are restored, species will recolonise them. However, the ability of a species to recolonise a restored site will depend not only on the appropriate habitat being present, but also on the ability to get there. This is likely to depend on both the species’ dispersal behaviour and the position of a site in the landscape.

2. Animals with good potential for dispersal are more likely to be able to disperse to newly restored sites. Similarly, sites in lowland streams with limited altitudinal differences between sites may be easier to reach than upstream sites. This is because upstream sites are connected to one another via lowland streams that have different characteristics and therefore may be difficult for animals to traverse.

3. In this paper, genetic data from a range of freshwater species that have been analysed in my laboratory are used to assess the importance of life cycle and position in the landscape (i.e. upland versus lowland streams) on connectivity patterns (and thus recolonisation potential) among populations.

4. In general, contemporary dispersal across catchment boundaries is negligible, except for aquatic insects with an adult flight stage. Dispersal among streams within catchments appears to be more limited than was predicted from knowledge on life histories, except for fish in lowland rivers and streams.

5. As predicted, dispersal of fish, crustaceans and molluscs among streams within catchments is significantly greater in lowland rivers than in upland streams.

6. Overall, these analyses suggest that, with the exception of most insects, and fishes in lowland rivers, natural recolonisation of restored sites is only likely from sites within the same stream. If a species has disappeared from the whole stream, then restoration of habitat alone may not be sufficient for its re‐establishment.
Psychological aspects and coping styles of parents with Haemophilic child undergoing a programme of counselling and psychological support
Authors: BOTTOS A. M. , ZANON E. , SARTORI M. T. , GIROLAMI A.
Published: March 2007

Summary.  Parents of children affected by haemophilia must face, often without prior knowledge, the difficult challenge imposed by such a pathology. To satisfy the need of information, guideline and psychological support for a better quality of life, 30 parents with haemophiliac children have participated in a programme of counselling and psychological support. Such a programme has the aim of guiding the group trough a process of discovery, comparison and personal growth and stimulating adaptive processes of problem–solving and decision–making. The aim of this paper was to verify how the programme influenced coping strategies and other psychological constructs such as depression and anxiety. Subjects of this study were administered the following psychological tests: COPE (coping, orientation to problems experienced), BDI (beck depression inventory), STAI‐Y form (state–trait anxiety inventory) at the beginning and at the end of the programme. The results show that by the end of the programme subjects are characterized by a greater use of problem–focused coping strategies, typical of individuals who think that the situation is susceptible to change, and a minor use of emotion–focused coping strategies, related to individuals who regard the situation as immutable. The use of avoidance –focused coping strategies seems to remain at the same level even if it was low. Also the other psychological aspects investigated, namely depression and anxiety, did receive a positive influence. The results show how significant such programme has been for parents.
Self‐evaluation and peer review – an example of action research in promoting self‐determination of patients with rheumatoid arthritis
Authors: Löfman Päivi , Pietilä Anna‐Maija , Häggman‐Laitila Arja
Published: March 2007

Aims and objectives.  The aim of this paper was to describe the areas that have been performed well and the areas in need of further development of rheumatoid arthritis patients.

Background.  Nurses’ self‐evaluation and peer review are important methods for ascertaining the changes and success in the development of nursing practice. To date, there has been minimal research regarding the use of those evaluation methods in nursing practice.

Design.  The findings of self‐evaluation and peer review of nurses are described in a participatory action research study aimed at promotion of self‐determination for patients with rheumatoid arthritis.

Methods.  In self‐evaluation, the collection of data was accomplished using a self‐evaluation instrument with the permanent nursing staff (n = 18), then analysed through quantitative methods. For peer review, the data were gathered through focus groups (n = 21) using a tool similar to the one used for self‐evaluation. The participants included many of the same nurses as in self‐evaluation. The data were analysed using qualitative content analysis.

Results.  Well‐performed areas in nursing of rheumatoid arthritis patients were found to be promoting patient participation, supporting self‐determination, performing patient‐centred nursing and raising patient self‐respect. The areas in need of development were connected to the nursing staff themselves: increasing collaboration of nursing staff, decreasing authoritarianism in nursing care and developing nursing practice with colleagues.

Conclusions.  Self‐evaluation and peer review are complementary and support one another, especially since nurses were found to be more critical in their self‐evaluations than in peer review.

Relevance to clinical practice.  Both evaluation tools proved to be useful methods in the evaluation phase of the action research process as a means of professional development. Also assisting in the development of clinical nursing practice.
Difficult asthma: people's perspectives on taking corticosteroid therapy
Authors: Gamble Jacqueline , Fitzsimons Donna , Lynes Dave , Heaney Liam Gabriel
Published: March 2007

Aims and objectives.  This study aimed to explore the experiences of patients with difficult asthma, who take corticosteroid therapy, and provide insight into why some patients comply with therapy, whilst others do not.

Background.  Asthma is growing in prevalence and affects more than 100 million people worldwide. Corticosteroids are the mainstay treatment but, despite considerable risk to the individual in terms of morbidity and mortality, compliance is low. Previous research has been mainly quantitative and analysed variables associated with compliance, doing little to increase professional understanding of the patient's perspective on taking corticosteroid treatment.

Methods.  A hermeneutic phenomenological approach was selected as most appropriate for this study. Unstructured interviews were undertaken with a purposive sample of 10 participants. Interviews were taped, transcribed and the data were analysed using a multi‐step technique described by Holloway.

Findings.  Fear of side effects was the strongest theme to emerge; illustrated by the negative images participants described such as weight gain, anxiety, irritability and depression. Participants related control and power over their condition to knowledge and information. They wanted more information, but believed that health professionals assumed they were already well informed. Costs and benefits of treatment were weighed up before decisions were made. Participants described feelings of ‘not being themselves’ and personality changes resulting in the loss of their role within relationships. Routine, time and opinions of significant others, also impacted on taking steroids.

Conclusion.  Decision‐making was a complex process, involving evaluation of the personal costs and benefits of treatment; fear of side effects was the dominant concern. Compliance with treatment saves lives in this population.

Relevance to clinical practice.  This study uncovers issues participants consider when making decisions regarding adherence and highlights the importance of the nurse's role in eliciting patients’ concerns and the providing appropriate information to allay fears and misconceptions.
A review of clinical decision making: models and current research
Authors: Banning Maggi
Published: March 2007

Aims and objectives.  The aim of this paper was to review the current literature clinical decision‐making models and the educational application of models to clinical practice. This was achieved by exploring the function and related research of the three available models of clinical decision making: information‐processing model, the intuitive‐humanist model and the clinical decision‐making model.

Background.  Clinical decision making is a unique process that involves the interplay between knowledge of pre‐existing pathological conditions, explicit patient information, nursing care and experiential learning. Historically, two models of clinical decision making are recognized from the literature; the information‐processing model and the intuitive‐humanist model. The usefulness and application of both models has been examined in relation the provision of nursing care and care related outcomes. More recently a third model of clinical decision making has been proposed. This new multidimensional model contains elements of the information‐processing model but also examines patient specific elements that are necessary for cue and pattern recognition.

Design.  Literature review.

Methods.  Evaluation of the literature generated from MEDLINE, CINAHL, OVID, PUBMED and EBESCO systems and the Internet from 1980 to November 2005.

Results.  The characteristics of the three models of decision making were identified and the related research discussed.

Conclusions.  Three approaches to clinical decision making were identified, each having its own attributes and uses. The most recent addition to the clinical decision making is a theoretical, multidimensional model which was developed through an evaluation of current literature and the assessment of a limited number of research studies that focused on the clinical decision‐making skills of inexperienced nurses in pseudoclinical settings. The components of this model and the relative merits to clinical practice are discussed.

Relevance to clinical practice.  It is proposed that clinical decision making improves as the nurse gains experience of nursing patients within a specific speciality and with experience, nurses gain a sense of saliency in relation to decision making. Experienced nurses may use all three forms of clinical decision making both independently and concurrently to solve nursing‐related problems. It is suggested that O'Neill's clinical decision‐making model could be tested by educators and experienced nurses to assess the efficacy of this hybrid approach to decision making.
Nursing staff competence, work strain, stress and satisfaction in elderly care: a comparison of home‐based care and nursing homes
Authors: Hasson Henna , Arnetz Judith E
Published: March 2007

Abstract  Aims.  The aims of this study were to: (1) compare older people care nursing staff's perceptions of their competence, work strain and work satisfaction in nursing homes and home‐based care; and (2) to examine determinants of work satisfaction in both care settings.

Background.  The shift in older people care from hospitals to community‐based facilities and home care has had implications for nursing practice. Lack of competence development, high levels of work strain and low levels of work satisfaction among nursing staff in both care settings have been associated with high turnover. Few studies have compared staff perceptions of their competence and work in nursing homes as opposed to home‐based care.

Design.  A cross‐sectional questionnaire survey.

Methods.  Nursing staff perceptions of their competence, work strain, stress and satisfaction were measured by questionnaire in 2003 in two older people care organizations in Sweden. Comparisons of all outcome variables were made between care settings both within and between the two organizations. Multiple regression analysis was used to determine predictors of work satisfaction in home care and nursing homes respectively.

Results.  In general, staff in home‐based care reported significantly less sufficient knowledge compared with staff in nursing homes. However, home care staff experienced significantly less physical and emotional strain compared with staff in nursing homes. Ratings of work‐related exhaustion, mental energy and overall work satisfaction did not differ significantly between care settings. In both care settings, work‐related exhaustion was the strongest (inverse) predictor of work satisfaction.

Conclusions.  Future interventions should focus on counteracting work‐related exhaustion and improving competence development to improve work satisfaction among older people care nursing staff in both care settings.

Relevance to clinical practice.  Work‐related exhaustion and lack of competence development may have significant negative implications for work satisfaction among older people care nursing staff in both home care and nursing homes.
Nutritional screening and perceived health in a group of geriatric rehabilitation patients
Authors: Söderhamn Ulrika , Bachrach‐Lindström Margareta , Ek Anna‐Christina
Published: March 2007

Aims and objectives.  (i) To perform a nutritional screening using the Nutritional Form For the Elderly and relate the results to perceived health in a group of geriatric rehabilitation patients; and (ii) to compare the screening results and nurses’ nutritional notes in the nursing documentation.

Background.  Undernutrition is an under‐recognized problem among older patients. Using a screening instrument is a way to detect patients at risk for undernutrition.

Design.  A cross‐sectional study conducted in Sweden.

Methods.  A sample of 147 geriatric rehabilitation patients was consecutively included and was interviewed with the screening instrument, questions about background variables, perceived health and health‐related issues. Higher screening scores indicate higher risk for undernutrition. Parametric and nonparametric statistical tests were used. When nurses’ nutritional notes in the nursing documentation were corresponding to the content in any of the response alternatives for each screening item, the notes were marked as existent.

Results.  The screening results showed that 55% of the patients were at medium risk and 14% at high risk for undernutrition. Patients in perceived ill health had higher screening scores than those in perceived good health. Associations were also found between receiving help, perceiving helplessness, not being active and not feeling satisfied and higher screening scores. The content of nine of 15 items in the instrument was mentioned in a number of nursing records.

Conclusions.  The prevalence of older patients at medium or high risk for undernutrition was high. To be at high risk for undernutrition was associated with perceived ill health. Nurses’ nutritional notes in the nursing documentation showed deficiencies, indicating that all patients at medium or high risk for undernutrition were not identified.

Relevance to clinical practice.  The results suggest that nurses need a screening instrument to highlight older nutritional at‐risk patients in need of further awareness and investigation.
Predictors of psychosocial adjustment in people with physical disease
Authors: Kocaman Nazmiye , Kutlu Yasemin , Özkan Mine , Özkan Sedat
Published: March 2007

Aims.  The purpose of this paper was to examine the demographic, medical and psychosocial variables that result in the deterioration of psychosocial adjustment in patients with physical disease, the meaning their illness has for them and their coping style.

Methods.  The study was carried out in inpatient clinics of the Istanbul Faculty of Medicine (n = 198). The following evaluation instruments were used: a semi‐structured questionnaire, the Psychosocial Adjustment to Illness Scale‐Self Report (PAIS‐SR), the Meaning of Illness Questionnaire (MIQ), the Hospital Anxiety–Depression Scale, the Multivariate Perceived Social Support Questionnaire and the Ways of Coping Inventory (WCI). Variables to be related with psychosocial adjustment were analysed by using Forward Logistic Regression.

Results.  The mean age of patients was 36·9 (SD 12·9) (18–65), 55% of which were women, the average PAIS‐SR score was 1·02 (SD 0·41) (0·7–2·26); 47% of the patients had poor adjustment scores. Univariate analysis showed that psychosocial adjustment was affected by having children (p = 0·02), anxiety, depression, locus of control, perceived social support (p < 0·001), information level about their illness and its treatment (p = 0·01), the subscales of WCI [escape‐avoidance (p < 0·001), distancing (p = 0·002), planned problem solving (p < 0·001), positive re‐appraisal (p = 0·02)]. The psychosocial adjustment of patients with respiratory or infectious illnesses or bone‐muscle‐skeletal disorders was even less (p = 0·03). All 33 items of the MIQ were found to have a significant impact on psychosocial adjustment (p < 0·001). According to the regression analysis, the best predictors of psychosocial adjustment were: depression (p < 0·001) and the meaning of illness for patient (p < 0·01).

Conclusions.  Having a physical illness is an important stress factor. In providing assistance, a number of factors should be taken into consideration, including how the patient perceives his illness, the impact the illness has on the patient's life, and a determination of the degree of depression being experienced by the patient.

Relevance to clinical practice.  The study indicated some predictors in the assesment of psychosocial adjustment and care of patients with physical illness. In daily clinical practice, among the patients with physical illness, those with a negative perception of their illness and those who define depression should be given special attention for psychosocial support.
An investigation of overeruption of posterior teeth with partial occlusal contact
Authors: CRADDOCK H. L.
Published: March 2007

Summary  The need and demand for replacement of missing posterior teeth may increase as the UK population is predicted to be at least partially dentate for life. Replacement with either fixed or removable prostheses may be indicated, and the tooth positional changes of adjacent or opposing teeth may require consideration. The objectives of this study are to: (1) Investigate the extent of overeruption associated with partially opposed posterior teeth; (2) Determine if overeruption is associated with tipping of the partially opposed tooth and examine the extent of tip. Ninety‐one patients with either partially or completely unopposed posterior teeth were included in the study. For each group the extent of overeruption of the tooth was measured. Differences in the extent of overeruption and tipping were analysed. Correlations between the presence of partial tooth contact and the extent of overeruption and degree of tipping of the unopposed tooth were analysed. There was no significant difference in the extent of overeruption between the unopposed and partially opposed groups. The partially opposed teeth displayed a greater degree of tipping than the unopposed group. There was no significant correlation between the extent of overeruption and the degree of tipping, nor between the extent of overeruption and the presence of partial tooth contact. There was, a significant correlation between the degree of tooth tip and the presence of partial tooth contact. (1) Partial tooth contact does not appear to prevent or reduce overeruption; (2) Partially opposed teeth show an increased degree of tip relative to teeth with complete lack of occlusal contact. The findings suggest that partial tooth contact should not be relied on clinically to maintain vertical tooth position.
Evolutionary history of lamprey paired speciesLampetra fluviatilis(L.) andLampetra planeri(Bloch) as inferred from mitochondrial DNA variation
Authors: ESPANHOL RUTE , ALMEIDA PEDRO R. , ALVES M. JUDITE
Published: March 2007

A remarkable trend in the evolution of lampreys is the occurrence in most genera of ‘paired species’, in which the parasitic anadromous lampreys are believed to have given rise to nonparasitic freshwater resident populations. The present work examines the phylogeography of the European paired speciesLampetra fluviatilisandLampetra planeri, in an attempt to elucidate species pair evolutionary history. We studied sequence variation in cytochromeband ATPase 6, 8 mitochondrial genes in 63 individuals from 21 localities of the paired species throughout their distribution range. Results from the phylogenetic and nested clade analyses were largely consistent, suggesting the existence of three major evolutionary lineages: lineage I and possibly lineage II are widespread throughout Europe, while the most ancestral lineage III is apparently restricted to the Iberian Peninsula. The high genetic diversity observed in the Iberian Peninsula is probably the result of refugial persistence and subsequent accumulation of variation over several ice ages, whereas the low levels of genetic diversity observed in central and northern Europe should reflect a rapid postglacial colonization. Results suggest thatL. planerioriginated within at least two distinct evolutionary lineages, rejecting the single origin hypothesis. The observed lack of taxa monophyly within lineage I may be the result of ongoing gene flow if the two taxa are alternate life‐history forms of a single species. However, structure within lineage I is also consistent with the hypothesis of divergence of taxa after postglacial dispersion (around 2000 generations ago) with incomplete lineage sorting. Further testing of the alternative hypotheses is warranted.
Remnants of ancient genetic diversity preserved within captive groups of scimitar‐horned oryx (Oryx dammah)
Authors: IYENGAR A. , GILBERT T. , WOODFINE T. , KNOWLES J. M. , DINIZ F. M. , BRENNEMAN R. A. , LOUIS E. E. , MACLEAN N.
Published: March 2007

Scimitar‐horned oryx, now considered extinct in the wild, persists in large numbers in captivity. In this first molecular genetic study on this species, we explore the patterns of genetic diversity across European, North American, and a few other captive groups using microsatellite markers and mitochondrial control region sequencing. Strong population structure was not evident from microsatellite data but we discovered deep divergence within the mitochondrial DNA haplotypes from a network analysis where three disconnected networks were obtained, with estimated divergence times ofc.2.1–2.7 million years. Mismatch distribution analyses suggest population expansionsc.1.2 and 0.5 million years ago. We discuss our findings in the context of historical climatic changes in North Africa and use information obtained on current patterns of genetic diversity within captive groups to make recommendations for future captive management and reintroduction strategies.
Population structure and the co‐evolution between social parasites and their hosts
Authors: BRANDT MIRIAM , FISCHER‐BLASS BIRGIT , HEINZE JÜRGEN , FOITZIK SUSANNE
Published: March 2007

Co‐evolutionary trajectories of host–parasite interactions are strongly affected by the antagonists’ evolutionary potential, which in turn depends on population sizes as well as levels of recombination, mutation, and gene flow. Under similar selection pressures, the opponent with the higher evolutionary rate is expected to lead the co‐evolutionary arms race and to develop local adaptations. Here, we use mitochondrial DNA sequence data and microsatellite markers to assess the amount of genetic variability and levels of gene flow in two host–parasite systems, each consisting of an ant social parasite — the European slavemaker Harpagoxenus sublaevis and the North American slavemaker Protomognathus americanus— and its two main host species. Our population genetic analyses revealed limited gene flow between individual populations of both host and parasite species, allowing for a geographic mosaic of co‐evolution. In a between‐system comparison, we found less genetic variability and more pronounced structure in Europe, where previous behavioural studies demonstrated strong local adaptation. Within the European host–parasite system, the larger host species Leptothorax acervorum exhibited higher levels of both genetic variability and gene flow, and previous field data showed that it is less affected by the social parasite H. sublaevis than the smaller host Leptothorax muscorum, which has genetically depleted and isolated populations. In North America, the parasite P. americanus showed higher levels of gene flow between sites, but overall less genetic diversity than its hyper‐variable main host species, Temnothorax longispinosus. Interestingly, recent ecological and chemical studies demonstrated adaptation of P. americanus to local host populations, indicating the importance of migration in co‐evolutionary interactions.