bluuebunny/crossref_metadata_2025 huggingface dataset:
Nostalgia, goodness and ethical paradox
Authors: Brogden Lace Marie , Patterson Donna
Published: April 2007

We research in Saskatchewan, in the Dry Land elucidated by Trevor Herriot (2001). We start with his notion that `those of us who live west of the 100th meridian have been using nostalgia to construct a romance fiction out of our history… there is no denying the power of nostalgia' (p. 2). Our landscape shapes us as we in turn shape it, we feel obligated to be sensitive to the glamours of nostalgia. Our prairie landscape evokes questions: What does it mean to research ethically in this space? What are the possible foci of our nostalgia? And, how do we navigate the ethical paradoxes in which we find ourselves? This article argues that research pushed by cultural norms creates double-binds around notions of `good' and `R/right'. By juxtaposing nostalgia and goodness, we examine ethical paradoxes facing us as academics in renegotiating these double-binds.
Learning in focus groups
Authors: Wibeck Victoria , Dahlgren Madeleine Abrandt , Öberg Gunilla
Published: April 2007

The focus group is a research methodology in which a small group of participants gathers to discuss a specified issue under the guidance of a moderator. The discussions are tape-recorded, transcribed and analysed. Notably, the interaction between focus group participants has seldom been evaluated, analysed or discussed in empirical research. We argue that considering the focus group in light of current research into interaction in problem-based learning (PBL) tutorial groups would facilitate the deliberate exploitation of group processes in designing focus groups, staging data collection and analysing and interpreting data. When the analytical focus shifts from mere content analysis to an analysis of what the participants themselves are trying to learn, one can explore not only what the participants are talking about, but also how they are trying to understand and conceptualise the issue under discussion.
Simplifying the Personal Network Name Generator
Authors: Marin Alexandra , Hampton Keith N.
Published: April 2007

Researchers studying personal networks often collect network data using name generators and name interpreters. We argue that when studying social support, multiple name generators ensure that researchers sample from a multidimensional definition of support. However, because administering multiple name generators is time consuming and strains respondent motivation, researchers often use single name generators. We compared network measures obtained from single generators to measures obtained from a six-item multiple-name generator. Although some single generators provided passable estimates of some measures, no single generator provided reliable estimates across a broad spectrum of network measures. We then evaluated two alternative methods of reducing respondent burden: (1) the MMG, a multiple generator using the two most robust name generators and (2) the MGRI, a six-item name generator with name interpreters administered for a random subset of alters. Both the MMG and the MGRI were more reliable than single generators when measuring size, density, and mean measures of network composition or activity, though some single name generators were more reliable for measures consisting of sums or counts.
Describing Changes in Personal Networks over Time
Authors: Feld Scott L. , Suitor J. Jill , Hoegh Jordana Gartner
Published: April 2007

Social ties are continuously being created and lost as well as changing their nature over time. We emphasize that network descriptions are specific to their particular definitions of ties. Then, we suggest that studies of change can focus on: (1) individual ties, or whole personal networks; and (2) whether ties are gained or lost, or change their characteristics over time. For each of four possible study types, we describe an ideal type, provide a concrete empirical example, and briefly describe illustrative published work. Particular networks can rarely be regarded as random samples of meaningful populations, and generalization to populations of networks requires often challenging theoretical considerations of the nature of the relevant populations, as well as statistical considerations of random sampling error. Nevertheless, systematic description of changes within particular networks provides the bases for more general understanding of processes and outcomes of changes of social networks over time.
Policy Salience and the Causal Structure of Representation
Authors: Kuklinski James H. , McCrone Donald J.
Published: April 2007

In earlier research, Cnudde and McCrone (1966) presented a revised version of the Miller and Stokes model of representation, which they contend to be an accurate portrait of the causal processes by which public preferences are translated into roll call votes. Using nonrecursive analytic techniques, we reexamine their thesis and conclude that it is correct. On policy domains that representatives believe to be highly salient to their constituencies, legislators' perceptions are the key linkage mechanism. Conversely, when representatives see a policy domain as relatively less salient, the influence of their perceptions declines.
Candidate Images Among Voters and Nonvoters in 1976
Authors: Maddox William S.
Published: April 2007

An analysis of 1976 data indicates that nonvoters' images of presidential candidates do not differ drastically from the images expressed by voters. Nonvoters respond to fewer candidates and tend to rate some "outsider" figures more positively and "establishment" figures less positively. With regard to most candidates, however, nonvoters' perceptions resemble those of fellow partisan identifiers more than those of fellow nonvoters. Tests of candidate-related explanations of turnout provide more support for the "indifference" and "other preference" hypotheses than for alienation, but the utility of these explana tions varies across partisan groupings.
Nursing practice related to sexuality: A review and recommendations
Authors: Waterhouse Julie
Published: April 2007

Sexuality is an important aspect of patient care, but research consistently demonstrates that nurses do not address sexuality unless the client asks specific questions. Review of research on sexuality-related practice suggests that nurses acknowledge their professional responsiblity to address sexuality with clients, but may not feel comfortable doing so. Continuing education on sexuality is of questionable value in improving practice. Recommendations for improving sexuality-related practice include requiring multiple experiences addressing sexuality of nursing students and new staff, as well as increased research to identify more specific nursing strategies for addressing clients' sexual concerns.
Prescribing the boundaries of nursing practice: Professional regulation and nurse presaibing
Authors: Shepherd Eileen , Rafferty Anne Marie , James Veronica
Published: April 2007

In October 1994 nurse prescribing was launched for the first time in Britain in eight community demonstration sites. Using nurse prescribing as an illustration, this paper aims to explore the regulation of nursing and the influence of medicine on the expansion of the nurse's role. Arguing that professional development and regulation must be understood within the context of state control, the paper questions whether nurse prescribing represents a genuine development in nursing roles or is merely an act of tacit delegation by a medical profession which is itself subject to loss of autonomy. Recognising historical renegotiation in divisions of health-care labour, sections on the introduction of nurse prescribing; changing professional boundaries; and regulation in nursing, medicine and pharmacy, are used to critique nurse prescribing as an example of growing nursing professionalisation.
An exploration of clinical risk management from a nursing perspective
Authors: Faugier Jean , Ashworth Gina , Lancaster John , Ward Derek
Published: April 2007

This paper outlines the concept of clinical risk management (CRM), a vital component in health service providers' total quality strategies. It is argued that, owing to the nature of health-care professions, and the introduction of legislative changes, CRM has gained prominence as a proactive quality management strategy. The authors conclude that while CRM undoubtedly raises standards of patient care, the future implementation and direction of the strategy may be governed by both patient expectations and the changing nature of the'new NHS'.
Triangulation of data collection: Practicalities and problems in a study of informal carers of terminally ill cancer patients
Authors: Rose Karen E. , Webb Christine
Published: April 2007

Triangulation of data collection is often seen as a way of enhancing rigour in research. In a study of the experiences of informal carers of terminally ill cancer patients, a qualitative approach was employed, relying on unstructured interviews. However, it was planned to utilise a triangulation strategy by administering a mood adjective checklist (MACL) to informants. Justification for the choice of MACL is given, followed by discussion of the difficulties encountered when carrying out the research plan. Four reasons for these difficulties are identified: reliability of the instrument, duty of care, control, and mixing qualitative and quantitative research strategies. Some of these difficulties might apply generally to research studies but some were peculiar to the particular research situation. This highlights both the necessity to be sensitive to the special needs of different research populations and the advantage of adopting a flexible approach to triangulation in data collection. While information obtained from use of the MACL could not be used in the way originally intended, by adopting a flexible approach it was possible to use these data as a means of triangulating in a broader sense and thus to shed light from a different source on the caring experience.
The role of demonstrations in the learning of nursing psychomotor skills
Authors: Melby Vidar , Canning Anne , Coates Viv , Forster Alan , Gallagher Ann , McCartney Anne , McCartney Mary
Published: April 2007

The learning of nursing psychomotor skills has traditionally been associated with lecturer demonstrations. In recent years there has been an increased emphasis on the development of independent learning within nurse education, and this study aims to investigate the potential for self-learning of psychomotor skills in nursing. Students were sampled from a number of different nurse education facilities in Northern Ireland, and a true experiment was carried out. Results indicate that students can learn a psychomotor skill both with and without a demonstration. Students who received a demonstration appeared to pay more attention to the principles of asepsis and communication; however these students were also more likely to pick up bad habits from the lecturer. This study adds to the existing research base for the learning and teaching of psychomotor skills in nursing.
Stigma: Its impact on professional responses to the needs of marginalised groups
Authors: Faugier Jean , Sargeant Mary
Published: April 2007

The stigma associated with drug-use, prostitution and mental and physical illness is not just an experience, it is an active and dynamic process which is often perpetrated by professional responses. Stigma is a complex social phenomenon which resists simple definition. This paper examines the concept of stigma in relation to deviance and explores the notion of a trajectory from one to the other. It highlights the influence of public perceptions of deviance on drug abuse and explores the particular implications for female drug-users. By considering how the actions of health professionals may be reinforcing deviant labels, it emphasises the urgent need for educational interventions. Health professionals need to understand the sociological basis of stigma to create a consciousness of their own professional action. They are in a unique position to intervene and cut across this trajectory to promote awareness and change.
Nursing supply and demand: Reviewing the evidence
Authors: Buchan James , O'May Fiona
Published: April 2007

This paper reviews research on the supply of, and demand for, nurses. It examines the utility of various data indicators of nursing 'shortages' and highlights potential shortcomings in their application. The paper also assesses the linkages between nurses' pay and nurses' labour market behaviour, reviewing the comparatively few papers which have taken a UK perspective on this issue. The current situation of a mismatch between nurses' supply and demand in the UK is also examined, with the clear indication that there is the potential for an increase in mismatch as demand increases, while future supply appears problematic. Finally, the paper reviews the main recommendations from previous national studies on nursing shortages in the UK, and concludes that many lessons from these studies have been ignored, as a cycle of nursing shortages has continued to be apparent in the UK.
Designing questionnaires and achieving high response rates in a longitudinal study of nurse diplomates' careers
Authors: Robinson Sarah , Marsland Louise , Murrells Trevor , Hickey Gary , Hardyman Rachel , Tingle Alison
Published: April 2007

The careers of those qualifying from diploma courses are of considerable interest, given the substantial professional and financial investment made in the Project 2000 strategy. This paper is concerned with a longitudinal study of the careers of a nationally drawn cohort of diplomates qualifying from the adult, child, mental health and learning disability branches in 1997/98. Reasons for choosing a longitudinal design are described, together with the problems it presents and the strategies developed to tackle these in the course of the project to date. The paper then turns to the ways in which the aims of the project are being pursued in the context of two linked questionnaires: the first sent to the cohort at qualification and the second six months later. The importance of pilot work is discussed throughout the paper.
Clinical supervision in a mental health in-patient area
Authors: Hughes Robert , Morcom Carolyn
Published: April 2007

This longitudinal study aimed to identify those factors which hindered or enabled a system of clinical supervision to become established and maintained in a mental health in-patient area. It also aimed to examine the characteristics influencing the effectiveness of such a system. Results show that a committed, enthusiastic clinical manager is the key: when the physical environment and psychological atmosphere are conducive, irrefutable benefits are evident. The evidence suggests that the increased knowledge that results from the practice of clinical supervision would result in positive consequences at all levels of the organisation. Those factors which hindered supervision mainly related to practicalities, time management issues, and levels of support. Recommendations are related to the need for a comprehensive continuing training programme for all levels of nursing staff and the importance of strategic planning.
Overseas nurses' experiences of working in clinical settings in England, and the experiences of their hosts: A phenomenological study
Authors: Cooke Mary
Published: April 2007

This study examined the views of overseas nurses visiting clinical areas in England and compared their views with the opinions of the host nurses and midwives. The views of higher education managers who supported the visits was also explored. The views of theorists such as Husserl, Heidegger, Sartre and Taylor are used to define the philosophy underpinning the methodology. The methodology used is supported by Haase and themes devised by Schaffer are applied to assess the attitudes of the facilitators. Rigorous applications of criteria to determine credibility, applicability, consistency and confirmability have been applied. Visiting professionals' views were surveyed and taped interviews were transcribed. The higher education managers were interviewed and their transcripts were analysed. The findings provide an insight into the expectations of the visitors and their experiences, and these are contrasted with the activities and adaptations made by the clinical managers. The comments of the managers of the higher education institutes are diverse and offer positive and negative insights into the rationale for supporting the visits. The conclusions offer thought for further inquiry.
Patient-sensitive treatment decision- making? Preferences and perceptions in a sample of renal patients
Authors: Caress Ann-Louise , Luker Karen A. , Ackrill Peter
Published: April 2007

Patient participation in various aspects of healthcare is rapidly expanding. However, patients' preferences with regard to participation in treatment decision-making remain relatively under-explored, as does the congruence between such preferences and patients' perceptions of their actual role in decision-making. The aims of this study were to identify and to compare treatment decision-making role preferences and perceptions of the actual decisional role in a sample of renal patients.

A cross-sectional survey was conducted at a single regional renal unit in the North of England. A convenience sample of 405 patients was obtained (pre-dialysis N=155; dialysis N=103; transplant N=147). Preferred and perceived role were identified using a card sort technique (choice of five options, active to passive). Rationales for role preference were recorded verbatim.

Most patients were found to prefer passive (N=186, 45.9%; 95% Cl 41.2- 50.9) or collaborative (N=147; 36.3%; 95% Cl 31.3-40.7) decisional roles; perceived role was typically passive (N=319; 78.8%; 95% Cl 74.8-82.8). Trust in health professionals, perceived lack of knowledge and severity of condition were the most frequently cited determinants of role preference. Patients' decisional role preferences were often at variance with their perceived roles. Taking a highly active role in treatment decision-making was undesirable to most patients. Trust in healthcare professionals was an important contributor to desire to defer or retain control over treatment decisions.
Using single case experimental design to evaluate the clinical effect of a multidisciplinary training in psychosocial interventions for people with serious mental health problems
Authors: Repper Julie
Published: April 2007

The provision of skilled support for people with serious mental health problems is informed by research evidence that specific interventions can improve outcome for clients and their carers in a number of areas, and that professionals can be taught these skills. However, evidence of treatment gains is limited and tenuous: there are problems with definitions of populations and interventions, and there is poor comparability between studies. In addition, there are specific difficulties in the evaluation of multidisciplinary training where different professionals have different roles, responsibilities and levels of baseline knowledge and skills. This paper considers the use of single case experimental design in the evaluation of the clinical outcome of a multidisciplinary, postgraduate, skills-based training in psychosocial interventions for people who have serious mental health problems. Single case design has the potential to overcome many of the factors that militate against the use of a randomised controlled trial; furthermore, generalisability is improved by replication across a small group of mixed clients: it allows the impact of the course on each client to be assessed in terms of his/her own goals and permits some explanation of treatment effects as well as giving an insight into the factors which help and hinder students attempting to implement evidence-based practice with this client group.
Immigrants to the New World: Nursing as an academic discipline
Authors: Meerabeau Liz
Published: April 2007

The following is an edited version of Professor Liz Meerabeau's inaugural lecture given at the University of Greenwich on April 21, 1998
Research into school nursing: Some methodological questions
Authors: DeBell Diane
Published: April 2007

This paper explores a range of research methodology issues, all based in the social sciences, which emerged from an in-depth study of school nursing that was carried out in East Norfolk during 1996. The full report of the research itself (DeBell and Everett, 1997) presents the findings of that work. The paper here, in contrast, uses that research exercise as an opportunity to explore questions about research methodology and to suggest the philosophical roots of the methodological approaches used in this particular research. Such questions are usually only of secondary interest to the key findings in published work. Here, the findings are implied while the methodological issues are moved to the foreground. The underlying intention behind the paper is to reflect on some of the philosophical roots of the methodological approaches used in nursing research. In particular, the intention is to offer this specific research project as a subject for debate and discussion about research methodology itself. How do researchers design a project to answer a research question? What are the implications for research outcome, if any, of selecting one set of approaches rather than another? And, particularly, does nursing research need to establish its capability for philosophical reflection?
Shared decision-making using an interactive video disk system for women with early breast cancer
Authors: Maslin Anna M. , Baum Michael , Secker Walker Jan , A'Hern Roger , Prouse Andrew
Published: April 2007

This study piloted and evaluated an interactive video disk system (IVD) using a shared decision-making programme (SDP) for women with early breast cancer. The study aimed to determine the acceptability of an interactive video disk system, in addition to the standard informational care and support provided by the clinicians and clinical nurse specialist, as a means of providing information about the risks and benefits of treatment choices. An experimental randomised study design was chosen, using as its main outcome measures the SF36, the Hospital Anxiety and Depression (HAD) scale, and a further questionnaire aimed at eliciting patients' satisfaction with their treatment choice. One hundred patients were recruited, and at nine months 94% of questionnaires were returned. The HAD scale overall summary scores, for both groups, indicated a significant fall in anxiety at nine months (p<0.001). The SF36 Questionnaire demonstrated nil of significant note. The IVD system was very highly evaluated. When patients were asked if they would recommend the IVD to someone they knew with a diagnosis of breast cancer, 92% said 'yes'. Overall there was a high degree of satisfaction in both groups. The study does support the significance of effective communication by the clinician and clinical nurse specialist (CNS) in breast care. The use of the IVD technology appears to be acceptable to and highly rated by the women.
Comparing and contrasting unstructured interviews with newly qualified nurses and senior health service personnel
Authors: Marsland Louise
Published: April 2007

Fourteen newly qualified nurses and 27 senior health service personnel were interviewed, using an unstructured format, for a study exploring careers guidance. Through comparing and contrasting the two sets of interviews, important differences in the approaches required to elicit trustworthy data emerged. This paper covers strategies used to encourage participation, establish rapport, manage the interview, and keep the interview productive with members of the two groups. The implications of sampling strategies, the interview setting and gender issues are also considered.
meso-Tetrakis(α,α,α,α-o-amidophenyl)porphinatoiron(II) Bearing a Proximal Histidyl Group at the β-Pyrrolic Position via an Acyl Bond: Synthesis and O2 Coordination in Aqueous Media
Authors: Nakagawa Akito , Komatsu Teruyuki , Tsuchida Eishun
Published: April 2007

meso-Tetrakis(α,α,α,α-o-(1-methylcyclohexanamido)phenyl)porphinatoiron(III) bearing a proximal histidyl group at the β-pyrrolic position via an acyl bond (4c) has been synthesized. Human serum albumin (HSA) incorporating the ferrous complex (4d) formed a stable O2 adduct under physiological conditions (pH 7.4, 37 °C). Although an electron-withdrawing acyl group is attached to the porphyrin periphery, the O2-binding affinity of HSA-4d was slightly higher than that of a similar analogue with a histidyl–alkylene group (2d).
Ionic Liquid-mediated Preparation Strategy for CuCl Nanocrystal
Authors: Wang Ling , Xu Chao , Zhang Xiaochun , Ying Taokai
Published: April 2007

CuCl was obtained through a novel route in the absence of concentrated acid or additives. The formation of nanocrystal CuCl was confirmed by XRD, SEM, TEM, and EDX studies. In this paper, an ecologically and environmentally friendly preparation route of CuCl nanocrystal was proposed.
Lewis Acid Character of Zero-valent Gold Nanoclusters under Aerobic Conditions: Intramolecular Hydroalkoxylation of Alkenes
Authors: Kamiya Ikuyo , Tsunoyama Hironori , Tsukuda Tatsuya , Sakurai Hidehiro
Published: April 2007

Gold nanoclusters stabilized by poly(N-vinyl-2-pyrrolidone) (Au:PVP NCs, φ = 1.3 nm) behave as Lewis acid catalyst in aqueous media under aerobic conditions, to promote the intramolecular hydroalkoxylation of unactivated alkenes. Molecular oxygen generates a reaction center having the Lewis acidic character on the surface of Au NCs in which constituent gold atoms are formally in zero-valence state.
Amino Acid Derived Epoxide Ring Opening under Microwave Irradiation
Authors: Vaiana Nadia , Rizzi Luca , Romeo Sergio
Published: April 2007

A solvent-free microwave-assisted methodology for the obtainment of the hydroxyethylamine (HEA) isostere is described. A phenylalanine derived aminoalkyl epoxide is allowed to react with a dipeptide amine using basic alumina partially deactivated with water under microwave irradiation. The HEA is obtained in very short time (3 min). This methodology is amenable to application in a parallel or automatic sequential format.
Optimized Active Noise Control of Semiclosed Aircraft Interiors
Authors: Kletschkowski Thomas , Sachau Delf , Böhme Sten , Breitbach Harald
Published: April 2007

A new method for optimizing the actuator and sensor positions applied to active noise control of semiclosed aircraft interiors is presented. This approach starts with the measurement of transfer functions between all possible actuator and sensor positions. Based on these evidences the minimum number and optimal position of the actuators and sensors are computed by optimization. The expected noise reduction and the necessary electrical inputs are calculated for the optimal configuration. These numerical results are then compared with experimental data for the optimal setup implemented into a mock-up of the semiclosed aircraft interior.
Experimental Results on Active Control of Buzz Saw Noise Tones of Aero Engines
Authors: Maier R. , Zillmann J. , Enghardt L. , Genoulaz N.
Published: April 2007

The potential of active noise control (ANC) to reduce buzz saw noise tones has been evaluated in the framework of the European funded project SILENCE(R). A scaled fan with 0.85m diameter from Rolls-Royce was used as test vehicle. Testing took place at a new facility at Anecom Aerotest located near Berlin. The paper deals with the results obtained by applying a modal control algorithm [1], [2] developed by EADS-CRC. With this algorithm, control was restricted to single azimuthal modes, whereby the mode number is equal to the engine order due to the special properties of buzz saw noise tones. The algorithm and its realtime implementation are presented in some detail. Furthermore, main advantages as well as drawbacks of the control concept are discussed. A ring of 30 loudspeakers mounted at the inner wall of the inlet duct was used as secondary acoustic sources and a single ring with 30 microphones made from electret film material has been used as error sensors. The film microphones were directly glued on the inlet duct. The sound field with and without active control has been measured in the duct by two microphone rings upstream of the error sensor ring and in the far-field by a circular microphone array in a single plane. The far-field measurements have been evaluated by SNECMA. The induct measurements were used by DLR to perform a mode decomposition of the sound field. The control of up to 3 buzz saw noise tones has been successfully demonstrated simultaneously.
Design and Testing of a Hybrid Passive/Active Acoustic Treatment for Nacelle Inlets
Authors: Galland Marie-Annick , Mazeaud Benoit
Published: April 2007

This paper deals with the design and testing of a hybrid acoustic treatment combining porous material properties and active control techniques, intended to reduce time-varying tones in flow-duct applications. A dedicated digital adaptive feedback control algorithm was developed to operate independently cell by cell, enabling easy subsequent increase of the liner surface. Large active panels of 54 cells were tested with pure sine waves from 850 Hz to 2 kHz for flow velocities up to Mach 0.3. Convergence was very rapid and stable for all cells. A detailed analysis of the experimental results is given, with comparisons with results for numerical simulation in the no-flow case. In agreement with predictions, active functioning was generally more effective up to 1 kHz, and the hybrid liner provided overall noise reduction that was largely independent of frequency.
Reduction of Axial Turbomachinery Tonal Noise by Means of Flow Induced Secondary Sources Using an Extremum-Seeking Control Technique
Authors: Lemke O. , Becker R. , Neise W. , King R. , Möser M.
Published: April 2007

In conventional active noise control experiments, loudspeakers are used to generate the secondary anti-phase sound field to be superimposed destructively with the sound waves radiated from the primary source. In the present study, aerodynamic sound sources are used to actively control the tonal noise of an axial fan. This is achieved by disturbing the flow field around the blade tips in such a way that additional periodic forces are set up which in turn form the secondary sound sources. To disturb the flow, air is blown into the blade tip region through the casing wall. The resulting aerodynamic sound sources are adjustable in both amplitude and phase. Results for closed loop control of the blade passing frequency using an extremum-seeking control technique are presented.
The utility of transactional and transformational leadership for predicting performance and satisfaction within a path‐goal theory framework
Authors: Vecchio Robert P. , Justin Joseph E. , Pearce Craig L.
Published: April 2007

In a test of hypotheses derived from the integration of principles of path‐goal theory (House, 1996) and transformational leadership theory (Bass, 1985), data collected from 179 high school teachers and their principals were examined with hierarchical regression analysis. Augmentation analysis indicated that transactional leadership had a stronger role in explaining unique criterion variance beyond the contribution of transformational leadership, than did transformational leadership relative to transactional leadership. In addition, both the transactional and transformational leadership had a negative interactive relationship for predicting the outcome of performance, such that leader vision and leader intellectual stimulation were more positively correlated with employee performance when leader use of contingent reward was low. These augmentation effects, in conjunction with the findings of negative moderation, suggest that transactional leadership may have greater potential predictive value than previously assumed.
Noggin Inhibits Postoperative Resynostosis in Craniosynostotic Rabbits
Authors: Cooper Gregory M , Curry Chris , Barbano Timothy E , Burrows Anne M , Vecchione Lisa , Caccamese John F , Norbutt Craig S , Costello Bernard J , Losee Joseph E , Moursi Amr M , Huard Johnny , Mooney Mark P
Published: April 2007

Inhibition of bone formation after surgery to correct craniosynostosis would alleviate the need for secondary surgeries and decrease morbidity and mortality. This study used a single dose of Noggin protein to prevent resynostosis and improve postoperative outcomes in a rabbit model of craniosynostosis.

Introduction: Craniosynostosis is defined as the premature fusion of one or more of the cranial sutures, which causes secondary deformations of the cranial vault, cranial base, and brain. Current surgical intervention involves extirpation of the fused suture to allow unrestricted brain growth. However, resynostosis of the extirpated regions often occurs. Several bone morphogenetic proteins (BMPs), well-described inducers of ossification, are involved in bone healing. This study tested the hypothesis that a postoperative treatment with Noggin, an extracellular BMP inhibitor, can inhibit resynostosis in a rabbit model of human familial nonsyndromic craniosynostosis.

Materials and Methods: Thirty-one New Zealand white rabbits with bilateral coronal suture synostosis were divided into three groups: (1) suturectomy controls (n = 13); (2) suturectomy with BSA in a slow-resorbing collagen vehicle, (n = 8); and (3) suturectomy with Noggin in a slow-resorbing collagen vehicle (n = 10). At 10 days of age, a 3 × 15-mm coronal suturectomy was performed. The sites in groups 2 and 3 were immediately filled with BSA-loaded gel or Noggin-loaded gel, respectively. Serial 3D-CT scan reconstructions of the defects and standard radiographs were obtained at 10, 25, 42, and 84 days of age, and the sutures were harvested for histological analysis.

Results: Radiographic analysis revealed that Noggin-treated animals had significantly greater coronal suture marker separation by 25 days and significantly greater craniofacial length at 84 days of age compared with controls. 3D-CT analysis revealed that Noggin treatment led to significantly greater defect areas through 84 days and to increased intracranial volumes at 84 days of age compared with other groups. Histological analysis supported CT data, showing that the untreated and BSA-treated groups had significant healing of the suturectomy site, whereas the Noggin-treated group had incomplete wound healing.

Conclusions: These data support our hypothesis that inhibition of BMP activity using Noggin may prevent postoperative resynostosis in this rabbit model. These findings also suggest that Noggin therapy may have potential clinical use to prevent postoperative resynostosis in infants with craniosynostosis.
Genetic Architecture of Conspecific Sperm Precedence inAllonemobius fasciatusandA. socius
Authors: Britch Seth C , Swartout Emma J , Hampton Daniel D , Draney Michael L , Chu Jiming , Marshall Jeremy L , Howard Daniel J
Published: April 2007

The evolution of barriers to gene exchange is centrally important to speciation. We used the crickets Allonemobius fasciatus and A. socius to investigate the genetic architecture of conspecific sperm precedence (CSP), a postinsemination prezygotic reproductive barrier. With amplified fragment-length polymorphism (AFLP) markers and controlled crosses we constructed linkage maps and estimated positions of QTL associated with CSP. The majority of QTL have low to moderate effects, although a few QTL exist in A. socius with large effects, and the numbers of QTL are comparable to numbers of genes accounting for species differences in other studies. The QTL are spread across many unlinked markers, yet QTL placed with linked markers are on a small number of linkage groups that could reflect the role of the large Allonemobius sex chromosome in prezygotic isolation. Although many QTL had positive effects on conspecific sperm utilization several QTL also exerted negative effects, which could be explained by intraspecific sexual conflict, sperm competition, or epistasis of introgressed genes on novel backgrounds. One unexpected outcome was that A. socius CSP alleles have a stronger effect than those from A. fasciatus in hybrid females, causing hybrids to behave like A. socius with regard to sperm utilization. Implications of this asymmetry in the Allonemobius hybrid zone are discussed.
Genetic Modifiers of the Drosophila Blue Cheese Gene Link Defects in Lysosomal Transport With Decreased Life Span and Altered Ubiquitinated-Protein Profiles
Authors: Simonsen Anne , Cumming Robert C , Lindmo Karine , Galaviz Vanessa , Cheng Susan , Rusten Tor Erik , Finley Kim D
Published: April 2007

Defects in lysosomal trafficking pathways lead to decreased cell viability and are associated with progressive disorders in humans. Previously we have found that loss-of-function (LOF) mutations in the Drosophila gene blue cheese (bchs) lead to reduced adult life span, increased neuronal death, and widespread CNS degeneration that is associated with the formation of ubiquitinated-protein aggregates. To identify potential genes that participate in the bchs functional pathway, we conducted a genetic modifier screen based on alterations of an eye phenotype that arises from high-level overexpression of Bchs. We found that mutations in select autophagic and endocytic trafficking genes, defects in cytoskeletal and motor proteins, as well as mutations in the SUMO and ubiquitin signaling pathways behave as modifiers of the Bchs gain-of-function (GOF) eye phenotype. Individual mutant alleles that produced viable adults were further examined for bchs-like phenotypes. Mutations in several lysosomal trafficking genes resulted in significantly decreased adult life spans and several mutants showed changes in ubiquitinated protein profiles as young adults. This work represents a novel approach to examine the role that lysosomal transport and function have on adult viability. The genes characterized in this study have direct human homologs, suggesting that similar defects in lysosomal transport may play a role in human health and age-related processes.
Gametogenesis in the Chlamydomonas reinhardtii minus Mating Type Is Controlled by Two Genes, MID and MTD1
Authors: Lin Huawen , Goodenough Ursula W
Published: April 2007

In the unicellular algae Chlamydomonas reinhardtii, the plus and minus mating types are controlled by a complex locus, MT, where the dominant MID gene in the MT− locus has been shown to be necessary for expression of minus-specific gamete-specific genes in response to nitrogen depletion. We report studies on MID expression patterns during gametogenesis and on a second gene unique to the MT− locus, MTD1. Vegetative cells express basal levels of MID. An early activation of MID transcription after nitrogen removal, and its sequence similarity to plant RWP-RK proteins involved in nitrogen-responsive processes, suggest that Mid conformation/activity may be nitrogen sensitive. A second stage of MID upregulation correlates with the acquisition of mating ability in minus gametes. Knockdown of MTD1 by RNAi in minus strains results in a failure to differentiate into gametes of either mating type after nitrogen deprivation. We propose that intermediate Mid levels are sufficient to activate MTD1 transcription and to repress plus gamete-specific genes and that MTD1 expression in turn allows the threshold-level MID expression needed to turn on minus gamete-specific genes. We further propose that an MTD1-equivalent system, utilizing at least one gene product encoded in the MT+ locus, is operant during plus gametogenesis.
Characterization of BEAF Mutations Isolated by Homologous Recombination in Drosophila
Authors: Roy Swarnava , Gilbert Matthew K , Hart Craig M
Published: April 2007

The Drosophila BEAF-32A and BEAF-32B proteins bind to the scs′ insulator and to hundreds of other sites on Drosophila chromosomes. These two proteins are encoded by the same gene. We used ends-in homologous recombination to generate the null BEAFAB-KO allele and also isolated the BEAFA-KO allele that eliminates production of only the BEAF-32A protein. We find that the BEAF proteins together are essential, but BEAF-32B alone is sufficient to obtain viable flies. Our results show that BEAF is important for both oogenesis and development. Maternal or zygotic BEAF is sufficient to obtain adults, although having only maternal BEAF impairs female fertility. In the absence of all BEAF, a few fertile but sickly males are obtained. Using both a chromosomal position-effect assay and an enhancer-blocking assay, we find that BEAF is necessary for scs′ insulator function. Lack of BEAF causes a disruption of male X polytene chromosome morphology. However, we did not find evidence that dosage compensation was affected. Position-effect variegation of the wm4h allele and different variegating y transgenes was enhanced by the knockout mutation. Combined with the effects on male X polytene chromosomes, we conclude that BEAF function affects chromatin structure or dynamics.
A Primary Assembly of a Bovine Haplotype Block Map Based on a 15,036-Single-Nucleotide Polymorphism Panel Genotyped in Holstein–Friesian Cattle
Authors: Khatkar Mehar S , Zenger Kyall R , Hobbs Matthew , Hawken Rachel J , Cavanagh Julie A L , Barris Wes , McClintock Alexander E , McClintock Sara , Thomson Peter C , Tier Bruce , Nicholas Frank W , Raadsma Herman W
Published: April 2007

Analysis of data on 1000 Holstein–Friesian bulls genotyped for 15,036 single-nucleotide polymorphisms (SNPs) has enabled genomewide identification of haplotype blocks and tag SNPs. A final subset of 9195 SNPs in Hardy–Weinberg equilibrium and mapped on autosomes on the bovine sequence assembly (release Btau 3.1) was used in this study. The average intermarker spacing was 251.8 kb. The average minor allele frequency (MAF) was 0.29 (0.05–0.5). Following recent precedents in human HapMap studies, a haplotype block was defined where 95% of combinations of SNPs within a region are in very high linkage disequilibrium. A total of 727 haplotype blocks consisting of ≥3 SNPs were identified. The average block length was 69.7 ± 7.7 kb, which is ∼5–10 times larger than in humans. These blocks comprised a total of 2964 SNPs and covered 50,638 kb of the sequence map, which constitutes 2.18% of the length of all autosomes. A set of tag SNPs, which will be useful for further fine-mapping studies, has been identified. Overall, the results suggest that as many as 75,000–100,000 tag SNPs would be needed to track all important haplotype blocks in the bovine genome. This would require ∼250,000 SNPs in the discovery phase.
Mitochondrial Genome Haplotype Hypervariation Within the Isopod Parasitic Nematode Thaumamermis cosgrovei
Authors: Tang Sha , Hyman Bradley C
Published: April 2007

Characterization of mitochondrial genomes from individual Thaumamermis cosgrovei nematodes, obligate parasites of the isopod Armadillidium vulgare, revealed that numerous mtDNA haplotypes, ranging in size from 19 to 34 kb, are maintained in several spatially separated isopod populations. The magnitude and frequency of conspecific mtDNA size variation is unprecedented among all studied size-polymorphic metazoan mitochondrial genomes. To understand the molecular basis of this hypervariation, complete nucleotide sequences of two T. cosgrovei mtDNA haplotypes were determined. A hypervariable segment, residing between the atp6 and rrnL genes, contributes exclusively to T. cosgrovei mtDNA size variation. Within this region, mtDNA coding genes and putative nonfunctional sequences have accumulated substitutions and are duplicated and rearranged to varying extents. Hypervariation at this level has enabled a first insight into the life history of T. cosgrovei. In five A. vulgare hosts infected with multiple nematodes, four carried nematodes with identical mtDNA haplotypes, suggesting that hosts may become infected by ingesting a recently hatched egg clutch or become parasitized by individuals from the same brood prior to dispersal of siblings within the soil.
Joint Estimates of Quantitative Trait Locus Effect and Frequency Using Synthetic Recombinant Populations ofDrosophila melanogaster
Authors: Macdonald Stuart J , Long Anthony D
Published: April 2007

We develop and implement a strategy to map QTL in two synthetic populations of Drosophila melanogaster each initiated with eight inbred founder strains. These recombinant populations allow simultaneous estimates of QTL location, effect, and frequency. Five X-linked QTL influencing bristle number were resolved to intervals of ∼1.3 cM. We confirm previous observations of bristle number QTL distal to 4A at the tip of the chromosome and identify two novel QTL in 7F–8C, an interval that does not include any classic bristle number candidate genes. If QTL at the tip of the X are biallelic they appear to be intermediate in frequency, although there is evidence that these QTL may reside in multiallelic haplotypes. Conversely, the two QTL mapping to the middle of the X chromosome are likely rare: in each case the minor allele is observed in only 1 of the 16 founders. Assuming additivity and biallelism we estimate that identified QTL contribute 1.0 and 8.7%, respectively, to total phenotypic variation in male abdominal and sternopleural bristle number in nature. Models that seek to explain the maintenance of genetic variation make different predictions about the population frequency of QTL alleles. Thus, mapping QTL in eight-way recombinant populations can distinguish between these models.
The Bursicon Gene in Mosquitoes: An Unusual Example of mRNA Trans-splicing
Authors: Robertson Hugh M , Navik Julia A , Walden Kimberly K O , Honegger Hans-Willi
Published: April 2007

The bursicon gene in Anopheles gambiae is encoded by two loci. Burs124 on chromosome arm 2L contains exons 1, 2, and 4, while burs3 on arm 2R contains exon 3. Exon 3 is efficiently spliced into position in the mature transcript. This unusual gene arrangement is ancient within mosquitoes, being shared by Aedes aegypti and Culex pipiens.
Sex-Specific Viability, Sex Linkage and Dominance in Genomic Imprinting
Authors: Van Cleve Jeremy , Feldman Marcus W
Published: April 2007

Genomic imprinting is a phenomenon by which the expression of an allele at a locus depends on the parent of origin. Two different two-locus evolutionary models are presented in which a second locus modifies the imprinting status of the primary locus, which is under differential selection in males and females. In the first model, a modifier allele that imprints the primary locus invades the population when the average dominance coefficient among females and males is $\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({>}\frac{1}{2}\) \end{document}$ and selection is weak. The condition for invasion is always heavily contingent upon the extent of dominance. Imprinting is more likely in the sex experiencing weaker selection only under some parameter regimes, whereas imprinting by either sex is equally likely under other regimes. The second model shows that a modifier allele that induces imprinting will increase when imprinting has a direct selective advantage. The results are not qualitatively dependent on whether the modifier locus is autosomal or X linked.