bluuebunny/crossref_metadata_2025 huggingface dataset:
Methodological issues in interviewing families in family nursing research
Authors: Åstedt‐Kurki Päivi , Paavilainen Eija , Lehti Kristiina
Published: March 2003

Methodological issues in interviewing families in family nursing research

Aim of the study. The aim of this study is to discuss what methodological problems can be met in family research with one family member as an interviewee speaking on behalf of the whole family and, vice versa, what is the meaning of having multiple family members or the whole family unit as informants.

Background. Family nursing research is part of multidisciplinary research with families. It is a basis for family nursing and contributes to research, especially from the perspective of family welfare and its promotion. Family nursing research generates knowledge concerning families’ and family members’ wellbeing and experiences and expectations of nursing and health care.

Methods. The examination of methodological problems while pursuing family research is based on two studies conducted in Finland.

Findings. Quantitative methods add to the general knowledge of families. Qualitative methods are well suited to the study of family experiences. Family interviews performed for research purposes differ from interviews aiming at caring for families. They aim at obtaining knowledge of families on a general level so as to improve family nursing. Family research has to be looked at as a whole. It faces many challenges such as the definition of the family, gaining access, methods of data collection and data management.

Conclusions. A family is a complex system and research with families need flexible, sensitive and practical methods. Family research should also aim at developing new methods for data collection and analysis.
Humour between nurse and patient, and among staff: analysis of nurses’ diaries
Authors: Åstedt‐Kurki Päivi , Isola Arja
Published: March 2003

Humour between nurse and patient, and among staff: analysis of nurses’ diaries

Aim of the study. The aim of this study was to investigate the occurrence of humour both between nurses and patients and among nursing staff.

Background. Humour has positive effects on both a person’s physiology and the psyche. Laughter signifies positive things to people; it may add to feelings of togetherness, closeness and friendliness. The use of humour is an indication of mental well‐being and it minimizes the effect of negative factors and protects from difficulties.

Methods. The data consisted of diaries written by nurses (n=16), which were analysed inductively using content analysis.

Findings. The main categories of humour between nurse and patient were nurse‐based humour, co‐operation‐orientated humour and patient‐orientated humour. Humour among staff consisted of the main category of resource‐orientated humour.

Conclusion. The consequences of humour between nurse and patient enabled them both to cope with various unpleasant procedures. It helped them to manage difficult situations and led to an improvement in the working climate. Humour among staff helped nurses to cope with their work and created a better atmosphere on the ward.
Exploring the Nursing Minimum Data Set for The Netherlands using multidimensional scaling techniques
Authors: Griens A.M.G.F. , Goossen W.T.F. , Van der Kloot W.A.
Published: March 2003

Exploring the Nursing Minimum Data Set for The Netherlands using multidimensional scaling techniques

Rationale. To fulfil the need for a systematic collection of nursing data that give insight in nursing care and its benefits and costs, a nursing minimum data set (NMDS) has been developed and validated for Dutch general hospitals. A NMDS provides data describing the diversity in patient populations and variability in nursing activities that can be analysed in various ways.

Aim of the study. To explore and compare the fundamental underlying dimensions describing patient problems and nursing interventions in Dutch general hospital wards.

Methods. Data of predominantly nominal and ordinal measurement level that were collected with the NMDS for The Netherlands on 15 Dutch hospital wards underwent two consecutive steps: first, they were transformed into metric data by means of RIDIT (relative to an identified distribution) analysis; secondly, they were analysed by means of multidimensional scaling.

Results. Multidimensional scaling techniques yielded a fairly good three‐dimensional solution of the NMDS data. Hospital wards could be distinguished from each other on the basis of patient problems and nursing interventions most common on some wards but not on others. The core aspects underlying patient problems concerned dependency problems, life threatening problems and endogenous–exogenous problems, while discriminating nursing interventions were cure–care activities, internally–externally oriented activities and psychosocial–physical interventions.

Limitations. Not all types of hospital wards were represented, which limits the representativity of the results for Dutch general hospitals. Furthermore, the patient sample size over the 15 wards was relatively small.

Conclusion. The constructs are consistent with NMDS findings in Belgium and findings from practice, which contributes to their content validity.
Thriving – a useful theoretical perspective to capture the experience of well‐being among frail elderly in nursing homes?
Authors: Bergland Ådel , Kirkevold Marit
Published: March 2003

Thriving – a useful theoretical perspective to capture the experience of well‐being among frail elderly in nursing homes?

Aim. The aim of this article is to discuss the concept of thriving and its adequacy in describing the experience of well‐being among physically frail nursing home residents.

Background. There is a lack of theoretical perspectives describing nursing home residents’ experience of well‐being.

Method. The article is based on a literature review and analysis of how the concept of thriving is used in different professional traditions. Three different theoretical perspectives are presented: (1) thriving as an outcome of growth and development; (2) thriving as a psychological state; (3) thriving as an expression of physical health state. In the second part of the paper, the three perspectives are discussed.

Conclusion. The authors suggest that there is a need to develop a new concept: that of thriving in physically frail nursing home residents. The article discusses how each of the three theoretical perspectives may contribute to the formation of this concept.
The needs of children visiting on adult intensive care units: a review of the literature and recommendations for practice
Authors: Clarke Clare , Harrison Dawn
Published: March 2003

The needs of children visiting on adult intensive care units: a review of the literature and recommendations for practice

Aim. The purpose of this paper is to review the current literature and research available and to identify specific, nursing interventions to meet the needs of child visiting within the ICU setting.

Background. According to recent surveys children are still restricted from visiting their critically ill family and friends on many adult intensive care units (ICUs) within the United Kingdom (UK). Imposing restrictive visiting policies does not respect the rights of patients and their families to be together and to support each other during a period of stress and crisis.

Method. The motivation to undertake the study was derived from a critical incident involving a small boy who was not allowed to visit his critically ill mother. She subsequently died. Reflection on the available literature identified the value and role of intuition in expert clinical judgement, but the need to support this with evidence based knowledge.

Conclusion. The implications for practice are discussed and recommendations for further research are made.
The changing training needs of clinical nurse managers: exploring issues for continuing professional development
Authors: Gould Dinah , Kelly Daniel , Goldstone Len , Maidwell Anna
Published: March 2003

The changing training needs of clinical nurse managers: exploring issues for continuing professional development

Aims of the study. To identify areas where clinical nurse managers perceived that they would benefit from further training and to make recommendations for planning future programmes to meet their needs.

Background. The effectiveness of the clinical nurse manager has traditionally been associated with maintaining standards of care. Continuing professional development (CPD) is essential to ensure this important group feel adequately prepared to perform their role and has been recognized as an important factor in maintaining job satisfaction and reducing wasteful staff turnover. A review of the literature indicated that since the 1980s the CPD needs of clinical nurse managers have tended to be overlooked despite increasing complexity of the tasks expected of them. Thus it appeared that a fresh study to address these needs would be justified and should take into account sources of work‐related stress and variables relating to job satisfaction.

Methods. The study involved clinical nurse managers employed in all four acute hospital National Health Service (NHS) trusts where training needs were served by a major inner city educational consortium. Data collection proceeded in two stages. Initially interviews were undertaken with a random sample of 15 clinical nurse managers to provide in‐depth, qualitative data. This information was used to develop a survey questionnaire distributed to the remaining 182 clinical nurse managers in each of the trusts.

Results. Data from the interviews indicated that clinical nurse managers appeared to feel clinically competent but generally experienced lack of confidence when dealing with a range of issues, in particular; human resources, managing budgets, deputizing for senior colleagues across the trust (‘acting up’) and using information technology in everyday practice. Response rate to the survey was good (65%). The results corroborated the interview findings, indicating a need for updating in the same wide range of topics. There were few differences in training needs across all four trusts. Clinical nurse managers who perceived that they had been well‐prepared for their role demonstrated higher levels of job satisfaction. Perceived preparation for clinical leadership was the same irrespective of the employing trust, length of time in post and other sociodemographic variables.

Conclusions. The study findings confirm that CPD remains a major issue for clinical nurse managers in the United Kingdom (UK) and that providing opportunities for such development may be an important factor in enhancing job satisfaction. The study findings should help those providing CPD to plan more effectively for this group and have implications for staff recruitment and retention.
Rethinking the birthing body: Cartesian dualism and perinatal nursing
Authors: Goldberg Lisa
Published: March 2003

Rethinking the birthing body: Cartesian dualism and perinatal nursing

Aim of the paper. This paper highlights the pervasive influence of a Cartesian metaphysics on the medical paradigm and its profound impact on the practice of perinatal nursing in North America.

Background. Modern perinatal health care practices are founded on a Cartesian metaphysics that reduce birthing women to the status of object. Such practices deny the holistic aims of perinatal nursing.

Methods. A philosophical inquiry informs the tenets of this metaphysical discussion regarding the foundations of perinatal nursing practices.

Findings. Although perinatal health care is founded on a Cartesian metaphysics, an alternative paradigm of embodied practice is suggested as a way of viewing birthing women as embodied subjects.

Conclusion. If the foundations of health care, which have been built on a Cartesian metaphysics, are not re‐examined, perinatal nurses will be providing care that further reduce women to the status of object.
Development of an instrument to measure strategic and clinical quality indicators in postoperative pain management
Authors: Idvall Ewa , Hamrin Elisabeth , Unosson Mitra
Published: March 2003

Development of an instrument to measure strategic and clinical quality indicators in postoperative pain management

Aim of the study. To develop and evaluate psychometric properties, that is reliability and validity, of an instrument to measure strategic and clinical quality indicators in postoperative pain management.

Background. Strategic and clinical quality indicators in postoperative pain management were previously developed from a tentative model of important aspects of surgical nursing care and assessed to have content validity, that is to be essential for the quality of care, realistic to carry out and possible for nurses to use to influence management.

Methods. The quality indicators were converted to items suitable for a patient questionnaire and were scored on a 5‐point scale, with higher scores indicating higher quality of care. Inpatients from five surgical wards took part in this study on their second postoperative day. The response rate was 96% and the average ages of the female (n=120) and the male (n=78) respondents were 62 and 63 years, respectively.

Results. Items in the total scale had an average inter‐item correlation >0·20 and an item‐total correlation >0·30. Cronbach’s coefficient α was 0·84 for the total scale. Four factors entitled ‘communication’, ‘action’, ‘trust’ and ‘environment’ emerged from an orthogonal factor analysis, with a cumulative variance of 61·4%. Patients who received epidural analgesia had higher scores on the total scale compared with those who did not receive epidural analgesia. Patients who reported more pain than expected had lower scores on the total scale compared with those who did not report more pain than expected. Correlation between the total scale and an overall pain relief satisfaction question was 0·53.

Conclusion. The results suggest initial support for the new instrument as a measure of strategic and clinical quality indicators in postoperative pain management, but it must be further refined, tested and evaluated.
SHORT REPORT: Nursing education in Norway
Authors: Kyrkjebø Jane Mikkelsen , Mekki Tone Elin , Hanestad Berit Rokne
Published: March 2003

Short Report: Nursing education in Norway

Aim. The aim of this paper is to describe nursing education in Norway and some essential questions and challenges regarding the undergraduate and newly graduated nurses' competencies and functionally preparedness.

Background. The first formal training of nurses in Norway started in Oslo in 1886. Since then the education has changed considerably. As long as society is changing, and nurses are going to meet and adapt to societies needs, the education of nurses will also have to change continuously. The present general plan of nursing education has gone through a long process. The discussions have concerned the content of medical and natural science subjects, the practical part of the training and the relation between theory and practice.

Challenges. There are challenges in nursing education in Norway today. We have seen that recruitment has decreased, and that nurses seek jobs where they are better paid. To increase the accessibility distance and part‐time education has been established. The theory–practice gap will always exist. Therefore we should aim to prepare the students to minimize this gap in a way that they can combine training of nursing with training in improvement. The demand of a masters degree to be a nursing teacher has reduced the teachers' ability to keep up their practical skills. The government pays nursing teachers who want to practice as nurses for several months to maintain their salary level during that period.

Conclusions. There are many possibilities to improve nursing education in Norway. We are on our way with highly qualified teachers and students, and we still have enough good applicants. The new general plan and new law for universities and university colleges offer great opportunities. However, the shortage of nurses is a great challenge for further quality improvement both in clinical practice and in education.
Defining and measuring nursing productivity: a concept analysis and pilot study
Authors: Holcomb Barbara R. , Hoffart Nancy , Fox Michael H.
Published: March 2003

Defining and measuring nursing productivity: a concept analysis and pilot study

Aims. The purpose of this article is fourfold. First we report a concept analysis of nursing productivity to show the complexity of the concept and its measurement. We then show how the concept analysis was used to design a method for measuring nursing productivity. Third, we describe how we used this measure in a pilot study of the impact of a differentiated Registered Nurse (RN) practice model on productivity. Finally, we identify the challenges encountered and present recommendations for nurse executives and researchers based on our findings.

Rationale. We believe our experience can be useful to nurse executives and researchers who are interested in studying the impact of care delivery models on nursing productivity.

Design. We defined productivity as the ratio of output (patient care hours per patient day) to input (paid salary and benefit dollars). We conducted a pilot test using the productivity measure developed from the concept analysis to determine the effects of a differentiated RN practice model on patient, staff, and organizational outcomes. The purpose of the pilot study was to determine whether the data needed to measure productivity could be obtained from administrative databases and to develop the steps and process for the analysis. We analysed data by 2‐week pay periods for two quarters prior to implementation of the differentiated nursing practice model and for two quarters after implementation to assess for changes in nursing productivity.

Results. Pilot testing showed that we could detect changes in productivity using this measurement approach. It also revealed several challenges in using administrative databases to measure productivity.

Conclusions. We discuss these challenges with recommendations for both nurse executives and researchers. The most reasonable approach for operational decision‐making is longitudinal monitoring of productivity by organizational units combined with indicators of quality of patient care.
Assessing practice of student nurses: methods, preparation of assessors and student views
Authors: Calman Lynn , Watson Roger , Norman Ian , Redfern Sally , Murrells Trevor
Published: March 2003

Assessing practice of student nurses: methods, preparation of assessors and student views

Aims. To describe the methods of measuring progress in achieving competence of preregistration nursing and midwifery students used by institutions of higher and further education in Scotland and to describe the philosophy and approaches to competence assessment in each institution.

Background. Institutions of higher and further education in Scotland operate a variety of schemes to assess the clinical practice of student nurses. These are based on different philosophies and practices and this raises the question of which are valid and reliable.

Methods. All institutions in Scotland providing validated Diploma of Higher Education programmes for preregistration nursing and midwifery participated in this study. Data were collected by postal questionnaire, review of programme documentation and supplemented with interviews with key stakeholders. The directors of the 13 programmes (seven nursing and six midwifery programmes) were surveyed and also 12 group interviews with students (six nursing and six midwifery student groups) from seven institutions. Students from all four branches were represented and 72 students (36 nurses and 36 midwives) were interviewed.

Results. Four key findings were identified and related to competence assessment methods, preparation of practice assessors, consequences of failure to meet expected level of outcome and students' views.

Conclusions. There has been a change in theoretical frameworks of assessment instruments used since the 1992 programmes commenced and only a limited number of approaches to clinical assessment are used in Scotland. Students' views suggested that they had little confidence in methods of clinical competence assessment and there was no formal validity and reliability testing within institutions. A lack of consistency in the training of student assessors in the clinical areas was identified. Some of these issues may be resolved with the development of a national instrument for competence assessment.
The construction of a modern epidemic: the implications for women of the gendering of coronary heart disease
Authors: Lockyer Lesley , Bury Michael
Published: March 2003

Aim.  This aim of this paper is to examine critically the implications for women of a gendered construction of coronary heart disease.

Design.  The paper takes the form of a literature review between 1969 and 2002 of nursing, medical and social science literature written in the English language that explores the experience of women with coronary heart disease.

Findings.  Coronary heart disease has been constructed during the 20th century as a disease of affluence that affects high achieving men. However coronary heart disease is a major cause of morbidity and mortality among women. The literature suggests that this gendered construction has influenced not only health professionals' perceptions of coronary heart disease but also lay theories of candidature, so that the collective consciousness sees women as being at low risk. Moreover, that this construction of coronary heart disease as a male disease has led to a service provision engineered to meet male needs that arguably can be seen to militate against women. This has resulted in women being diagnosed when they are further along the disease trajectory. It also means that once diagnosis has made then they are less likely to be referred for investigations, treatment and rehabilitation.

Conclusion.  The implications of this construction for the care of women with coronary heart disease may result in ‘gender‐neutral’ care. This may mean that decisions about care are made in the light of nurses' own knowledge and experience of nursing male patients, with the consequence that women patients' individual needs are not met.
Disability, spiritual beliefs and the church: the experiences of adults with disabilities and family members
Authors: Treloar Linda L.
Published: March 2003

Aims.  This paper reports the findings of a qualitative interpretive study that explored how people with disabilities and family members use their spiritual beliefs to establish meaning for disability, and to respond to the challenges of lived experience with disability. The participants' perceptions of the evangelical Christian church's influence on their spiritual experiences related to disability suggest recommendations for improved integration by the church. Applications are drawn for helping professionals and religious leaders who provide holistic care.

Background/rationale.  Although there is a well‐established literature on coping in families with disabled children, little is known about how people use spiritual beliefs to establish meaning for and respond to life with disability. Even less is known about how people with a particular set of shared spiritual beliefs make meaning for lived experience with disability.

Design/methods.  The author interviewed 30 persons, comprising two major groups: 13 parents of children with mixed developmental disabilities and nine adults with physical disabilities. Predominantly white, the participants lived in a south‐western metropolitan area in the United States of America (USA) in 1998.

Findings.  Trial or difficulty contributed to spiritual challenge, the breaking of self, reliance on God, and strengthened faith in God. The participants chose to live with thankfulness and joy despite difficulties common to experience with disability. The participants' spiritual beliefs stabilized their lives, providing meaning for the experience of disability, assistance with coping and other benefits. The participants' recommendations include increased assistance by the church in promoting theological understanding of disability, and religious support using a continuing model of caring.

Conclusions.  Although the study design limits the generalizability of the findings, applications can be drawn for helping professionals and religious leaders who provide holistic care
Nurse supervisors' actions in relation to their decision‐making style and ethical approach to clinical supervision
Authors: Berggren Ingela , Severinsson Elisabeth
Published: March 2003

Aim. The aim of the study was to explore the decision‐making style and ethical approach of nurse supervisors by focusing on their priorities and interventions in the supervision process.

Background. Clinical supervision promotes ethical awareness and behaviour in the nursing profession.

Methods. A focus group comprised of four clinical nurse supervisors with considerable experience was studied using qualitative hermeneutic content analysis.

Findings. The essence of the nurse supervisors' decision‐making style is deliberations and priorities. The nurse supervisors' willingness, preparedness, knowledge and awareness constitute and form their way of creating a relationship. The nurse supervisors' ethical approach focused on patient situations and ethical principles. The core components of nursing supervision interventions, as demonstrated in supervision sessions, are: guilt, reconciliation, integrity, responsibility, conscience and challenge. The nurse supervisors' interventions involved sharing knowledge and values with the supervisees and recognizing them as nurses and human beings.

Conclusion. Nurse supervisors frequently reflected upon the ethical principle of autonomy and the concept and substance of integrity. The nurse supervisors used an ethical approach that focused on caring situations in order to enhance the provision of patient care. They acted as role models, shared nursing knowledge and ethical codes, and focused on patient related situations. This type of decision‐making can strengthen the supervisees' professional identity. The clinical nurse supervisors in the study were experienced and used evaluation decisions as their form of clinical decision‐making activity. The findings underline the need for further research and greater knowledge in order to improve the understanding of the ethical approach to supervision.
An Experimental study of reduced parental effort and future reproductive success in the puffin, Fratercula arctica
Authors: Wernham Christine V. , Bryant David M.
Published: March 2003

1.  The puffin, a long‐lived seabird, was studied on the Isle of May, East Scotland between 1990 and 1992. During two of these years, parental effort was experimentally decreased by supplementary feeding of young. This aimed to identify inter‐year reproductive costs, and show whether they took the form of reduced adult survival, reduced fledging success and/or a reduction in the ‘quality’ of offspring in the following year.

2.  The feeding treatment significantly reduced the daily number of feeds delivered by experimental parents by 67% in 1990 and 87% in 1991.

3.  The proportions of experimental and control parents returning to the colony in the year following manipulation did not differ significantly, although in 1991, 2·5 times as many controls (young unfed) as experimental birds (young fed) failed to return.

4.  The fledging success of experimental pairs in the year following manipulation (68%) was significantly higher than that of controls (24%).

5.  Experimental pairs raised young with significantly higher body condition (Residual Peak Mass) than that of controls in the year following manipulation (1992).

6.  Experimental parents did not differ from controls in their body condition (Lipid Reserve Mass) or rate of reserve depletion, either in the year of manipulation or in the following breeding season; hence there was no evidence for a role of the measured component of body condition in the cost mechanism.

7.  The study demonstrated inter‐year reproductive costs for puffins and supported the hypothesis that long‐lived species reduce the ‘quality’ of their offspring or abandon a breeding attempt rather than compromise their survival and future opportunities to reproduce.
Winter herbivory by voles during a population peak: the relative importance of local factors and landscape pattern
Authors: HAMBÄCK PETER A. , SCHNEIDER MICHAEL , OKSANEN TARJA
Published: March 2003

1.  We studied the relative role of local habitat variables and landscape pattern on vole–plant interactions in a system with grey‐sided voles (Clethrionomys rufocanus (Sund.)) and their favourite winter food plant, bilberry (Vaccinium myrtillus L.). The study was conducted during a vole peak year (1992–93) in a tundra area in northern Norway.

2.  Using Mantel statistics we were able to separate the direct effects of the spatial patterning of habitats and the indirect effects due to spatial aggregations of similar habitats.

3.  Results indicate that knowledge about the explicit spatial patterning of patches does not improve our understanding of the system. Instead, two local factors, vegetation height and bilberry biomass, explained more than 50% of the variation in cutting intensity in winter (defined as the proportion of above‐ground shoots cut). Increasing vegetation height increased, and increasing bilberry biomass decreased, the cutting intensity.

4.  The conclusion that grey‐sided voles are able to distribute themselves relative to habitat quality was also partially supported by our estimated over‐winter persistence by voles in the various habitats. Vole persistence was uncorrelated with vegetation height, the important predictor of autumn vole density, but tended to correlate with the deviation from the relation between vegetation height and autumn vole density. This conforms to the expectations from the theory of ideal‐free habitat distribution.

5.  The cue for vole habitat choice, i.e. vegetation height, indicates that either predation or freezing risk is important for voles when selecting over‐wintering habitat.
A seasonal shift in egg‐laying behaviour in response to cues of future competition in a treehole mosquito
Authors: Edgerly J. S. , Mcfarland M. , Morgan P. , Livdahl T.
Published: March 2003

1. We tested a set of hypotheses to predict egg‐laying behaviour in Aedes triseriatus in the field in Massachusetts. These hypotheses reflect three main themes: females avoid competitive or predatory threats to their larvae; females judge larvae or eggs as cues to future permanence or productivity within a treehole; and females are either opportunistic ovipositors, or hedge their bets by scattering their eggs in multiple habitats. We predicted that mosquitoes might vary in their response depending on whether their offspring will hatch immediately or enter diapause and hatch the next year.

2. We stocked artificial treeholes with larvae at four densities ranging from 0 to 90 larvae per habitat for four trials in 1992 and eight trials in 1994. In 1992, we added predatory Anopheles barberi larvae to half the replicates of each density level. In 1994, we tested for an interaction between egg and larval density by stocking additional traps with eggs in batches of 0, 20 and 200, and larvae in densities as in the previous trials.

3. The population revealed a significant interaction between time of year and larval density. More eggs accumulated in traps stocked with fewer larvae (0 or 15) early in the season, but females showed a slight positive response to higher densities (45 or 90) later on, after their offspring were all likely to enter diapause. These results suggest that potential ambiguities of larval cues, with indications of habitat permanence as well as adversity of future competition, are resolved by females. Females did not respond differentially to the predatory Anopheles barberi larvae.

4. The estimated batch size obtained in oviposition traps did not differ from the fecundity of field‐caught females allowed to oviposit under confinement in laboratory vials, suggesting that bet‐hedging by scattering of eggs among multiple habitats did not occur.

5. An unexpected result, a positive response to higher egg densities, is discussed in light of studies on other insects. This result conflicts with our predictions based on females choosing less competitive environments for their larvae and also conflicts with previously published accounts of avoidance of eggs in this species. Preference for habitats with conspecific eggs might be explained if eggs reflect habitat stability or if larvae gain an advantage from being in an aggregation. Neither hypothesis is resolved by the present study.
Exploring stable pattern formation in models of tussock moth populations
Authors: Wilson William G. , Harrison Susan P. , Hastings Alan , Mccann Kevin
Published: March 2003

1. The western tussock moth (Orgyia vetusta) at the University of California Bodega Marine Reserve (Sonoma County, California, USA) exhibits dense, localized populations in the midst of extensive habitats where variation in host plant quality or predator abundance is unable to explain the restricted extent of the outbreaks.

2. Two primary features suggest that the host patterning is intrinsically generated: (i) female tussock moths are wingless, producing a low effective dispersal distance for the hosts; and (ii) the tussock moth population is attacked by several species of widely dispersing wasp and fly parasitoids.

3. We consider a set of spatially explicit host–parasitoid models to examine whether intrinsically generated patterns are possible within this system. These models include a spatially extended Nicholson–Bailey model to examine general features of pattern formation in host–parasitoid systems, and two system‐specific models, an individual‐based simulation and a population‐level analytic model, to examine the details of this empirical system.

4. Both stable patterning and rapid extinction of the host population are initial‐condition dependent outcomes of the general and specific models, implying that an intrinsically generated stable host pattern is feasible within the tussock moth system.

5. Stable patterning is enhanced by a large parasitoid‐to‐host dispersal ratio, local host resource limitation, and increased parasitism at the host patch's edge.
Associations between parasitism and host genotype in natural populations ofDaphnia(Crustacea: Cladocera)
Authors: Little Tom J. , Ebert Dieter
Published: March 2003

1. Numerous models of parasite−host coevolution have shown that parasitism could play a key role in a wide range of biological phenomena. One critical assumption underlying models of parasite−host coevolution is that natural selection acts on genetic variation for host susceptibility, but this assumption has rarely been tested in the wild.

2.Clonal hosts are particularly suitable for detecting associations between genotypes and parasitism, because multi‐locus gene complexes are preserved during reproduction, and following clonal selection, hosts which differ at resistance loci may also show differences at neutral marker loci. In this study, allozymes were used to search for associations between multi‐locus host genotypes (clones) and parasitism within 25 cyclically parthenogenetic populations ofDaphnia.

3.Rates of parasitism were observed ranging from 0% to 48% of adult females, and infection by microparasites was found to significantly reduce host fecundity.

4.Significant differences were detected between the clonal composition of parasitized and healthyDaphniain 12 populations, showing that the proportion of individuals infected varies among clones. Six populations were sampled repeatedly to determine whether this variation was associated with temporal changes in both host clonal frequencies and population genetic characteristics (Hardy−Weinberg equilibrium, genotypic linkage disequilibrium). Three of the six temporally sampled populations showed changes in genetic structure that were consistent with the expectations of parasite‐mediated selection, while the other three did not. These latter three populations all had low parasite prevalence (indicating low selection intensities) and/or comprised primarily rare clones, thus limiting the statistical power of the study to detect parasite‐mediated effects.

5.The results show the presence of genetic variation for the likelihood of contracting disease withinDaphniapopulations. These associations between infection and host genotype could result from genetic variation for parasite resistance or within‐pond spatial arrangement of both host genotypes and parasite prevalences. Either factor would lead to parasite‐mediated selection and the modulation of gene frequecies within populations.
Coexistence mechanisms of mycophagous drosophilids on multispecies fungal hosts: aggregation and resource partitioning
Authors: Toda Masanori J. , Kimura Masahito T. , Tuno Nobuko
Published: March 2003

1. In nature various mechanisms that provide some refuges for inferior species to escape from competition act together to promote the species coexistence in a local community. We propose a method to evaluate simultaneously the relative importance of different mechanisms for the species coexistence, focusing on a mycophagous drosophilid community depending on a multispecies fungal host system, where two mechanisms – aggregation over patches of single fungal species and resource partitioning at the fungal species level – can act together. The data are based on the numbers of adult insects emerging from naturally occurring fungi collected from a temperate forest in northern Japan.

2.We confirm the finding ofSevenster & van Alphen (1996)that large patches are low‐density refuges despite the large absolute numbers of competitors on them, and therefore adopt new measures for intra‐ and interspecific aggregations and the species‐persistence criterion, which were developed bySevenster (1996)to take account of variable patch sizes in calculating the aggregation measures.

3.The calculated measures are compared among three analyses for fungal resources: AR‐analysis (the original data‐set from multispecies fungal patches) in which both aggregation and resource partitioning can act together; R‐analysis (combining the data for all patches of each fungal species) in which only resource partitioning at the fungal species level can act; and A‐analysis (calculating the measures independently for each fungal species) in which only aggregation process can act as a coexistence mechanism.

4.Intraspecific aggregation over multispecies fungal patches is strengthened by both aggregation and resource partitioning processes.

5.We reconfirm the finding ofSevenster & van Alphen (1996)that interspecific associations are consistent over years, and support their claim that such consistent associations should be taken as real aspects of the community structure.

6.Measures for the persistence criterion (T), the ‘relative effect of competitor aggregation’, are less than unity, satisfying the necessary and sufficient condition for the species persistence, in most drosophilid species concerned; these tend to be smaller in AR‐analysis than in R‐ or A‐analysis, suggesting facilitation of the species coexistence by both aggregation and resource partitioning in the mycophagous drosophilid community studied.

7.Differences inT‐value between AR‐ and R‐analyses and between AR‐ and A‐analyses may indicate relative contributions of aggregation and resource partitioning, respectively, to the species coexistence. We propose a method to compare various communities in a multi‐dimensional space with regard to the relative importance of different coexistence mechanisms.
Effects of experimental habitat fragmentation and connectivity on root vole demography
Authors: Ims Rolf A. , Andreassen Harry P.
Published: March 2003

1. We used a factorial experimental design to test whether habitat fragmentation (two different fragment sizes) and connectivity (presence and absence of corridors between small fragments) affected population growth rate and two conventional measures of the demographic structure (proportion of reproductive adults and sex ratio) in 12 enclosed populations of root voles.

2. Because the matriline has been suggested to be a functional entity affecting the demography of Microtus populations, we employed a study protocol (including laboratory‐raised founder animals and intensive live trapping combined with fluorescent powder techniques), which enabled us to track the matrilineal genealogy in the populations. Thus, the effect of habitat structure on the matrilineal structure of the populations, quantified by the Shannon–Wiener diversity index, could be tested for the first time.

3. Population growth rate was density dependent, but neither this population parameter nor sex ratio and proportion of reproductive adults differed between the habitat treatments. This was unexpected since the presumed determinants of Microtus demography, such as individual space use, dispersal distances and spatio‐social organization had earlier been found to differ between the treatments.

4. The matrilineal structure (diversity) of the populations changed in response to the experimental habitat manipulations. In corridor‐connected systems, some matrilines became numerically dominant, which lead to reduced matrilineal diversity compared to systems with isolated habitat fragments. We hypothesize that some matrilines were able to colonize and exploit corridor‐connected fragments better than other matrilines. Matrilineal diversity was not related to any other demographic attribute (growth rate, sex ratio and functional stage structure) at the population level.

5. Our results suggest that fragmentation‐induced changes of individual and matrilineal level attributes do not necessarily propagate into population level differences in vital rates. The notion that matrilines may be a functional entity in Microtus populations could not be supported.

6. Our experimental results suggest that population genetics, more than population demography, may be sensitive to habitat fragmentation and connectivity, within the specific temporal and spatial extent explored. In particular, the effect of corridors on matrilineal diversity imply that population genetic studies based on mtDNA markers should consider habitat connectivity when analysing genetic diversity.
Are incubation and fledging periods longer in the tropics?
Authors: Geffen Eli , Yom‐Tov Yoram
Published: March 2003

1. It is commonly believed that the smaller clutch size of tropical compared with temperate birds is a response to a high predation rate. If this is true, one would expect incubation and fledging periods in the tropics to be shorter than in temperate regions, but they are generally thought to be longer in the tropics than in northern temperate areas.

2. In this paper we show that among passerines in both the Old and the New World, there is little or no difference in either incubation or fledging periods between temperate and tropical areas.

3. We suggest that tropical birds differ from temperate ones in their clutch size and extended post‐fledging periods, which is necessary for juvenile survival, but probably not in other life history parameters.
A state‐dependent model of activity patterns in homing limpets: balancing energy returns and mortality risks under constraints on digestion
Authors: Burrows Michael T. , Santini Giacomo , Chelazzi Guido
Published: March 2003

1. Different species of limpets, and different populations of the same species, show an impressive variation in temporal organization of foraging activity. Field studies also reveal different patterns of activity among individuals of the same population.

2. Many hypotheses have been proposed to explain the observed behavioural patterns, in terms of effects of several biotic and abiotic factors acting in different tidal phases, yet without taking into account possible interactions among environmental and internal factors. Moreover, the importance of energy reserves and food processing has rarely been considered in this context.

3. The role of different environmental factors and functional traits in shaping the organization of foraging of limpets at different time scales was analysed by using a state‐dependent optimal foraging model, based on stochastic dynamic programming. The model includes interaction among mortality risks and energy costs incurred during the different tidal phases, the effect of different levels of energy reserves, gut fullness and changing food availability.

4. The model is able to reproduce a variety of foraging patterns with reference to the tidal cycle when changing combinations of values assigned to the risk of mortality, energy costs and food availability. The model also shows that the level of energy reserves, gut volume and rate of food processing can be of major importance in determining the short‐term organization of activity within each foraging phase.
Contrasting interference functions and foraging dispersion in two species of shorebird (Charadrii)
Authors: Yates Michael G. , Stillman Richard A. , Goss‐Custard John D.
Published: March 2003

1. Above a threshold density of ≈ 100 birds ha‐1, strong interference occurred between redshankTringa totanus(Linnaeus) feeding by sight on the amphipod crustaceanCorophium volutator(Pallas). No aggressive interactions occurred between the birds and the probable cause was prey depression.

2. Redshank fed in a square metre of mud that had recently been exploited by another redshank much less often than would be expected by chance. By avoiding areas where prey would have been recently exploited, the feeding rate of redshank was up to three times faster than it would have been had they not avoided other foraging redshank.

3. Bar‐tailed godwit fed in a square metre of mud that had been recently exploited by another godwit much more often than would be expected by chance in randomly moving birds. They tended to flock while foraging and showed no tendency to avoid areas where prey would have been recently exploited.

4. There was no evidence that interference occurred between bar‐tailed godwitLimosa lapponica(Linnaeus) feeding on the polychaete lugwormArenicola marina(Linnaeus) at densities below 300 birds ha‐1, even though aggressive interactions occurred between birds.