bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inter‐ocean dispersal is an important mechanism in the zoogeography of hakes (Pisces:Merlucciusspp.)
Authors: Grant W. Stewart , Leslie Robin W. 
Published: March 2003

AimTo present new genetic data and to review available published genetic data that bear on the phylogeny of hakes in the genusMerluccius. To construct a zoogeographical model from a summary phylogenetic tree with dated nodes. To search for an explanation of antitropical distributions in hakes. To assess peripheral isolate, centrifugal and vicariance models of speciation in view of the molecular phylogeny and zoogeography of hakes.LocationsNorthern and southern Atlantic Ocean, eastern Pacific Ocean, South Pacific Ocean.MethodsElectrophoretic analysis of 20 allozyme loci in 10 species of hakes. Phylogenetic tree construction with parsimony and bootstrap methods. Reanalysis of previous genetic data. Analysis of zoogeographical patterns with geographical distributions of molecular genetic markers.ResultsPhylogenetic analyses of new and previous allozyme data and previous mitochondrial DNA data indicate a deep genetic partition between Old‐ and New‐World hakes with genetic distances corresponding to 10–15 Myr of separation. This time marks a widening rift between Europe and North America and a rapid drop in ocean temperatures that subdivided an ancestral population of North Atlantic hake. Two Old‐World clades spanning the equator include pairs of sister taxa separated by tropical waters. Divergence times between these pairs of sister‐taxa variously date to the early Pliocene and late Pleistocene. Amongst New‐World hakes, pairs of sister taxa are separated by equatorial waters, by the Southern Ocean, and by the Panama Isthmus. These genetic separations reflect isolation by the rise of the Isthmus 3–4 Ma and by Pliocene and Pleistocene dispersals. Pairs of species occurring in sympatry or parapatry in six regions do not reflect sister‐species relationships, but appear to reflect allopatric divergence and back dispersals of descendent species. Some geographically isolated regional populations originating within the last few hundreds of thousands of years merit subspecies designations.ConclusionsVicariance from tectonic movement of continental plates or ridge formation cannot account for the disjunct distributions of most hake sister taxa. Molecular genetic divergences place the origin of most hake species diversity in the last 2–3 Myr, a period of negligible tectonic activity. Distributions of many hake species appear to have resulted from dispersals and back dispersals across both warm equatorial waters and cool waters in the Southern Ocean, driven by oscillations in climate and ocean temperatures. Genetic and ecological divergence prevents hybridization and competitive exclusion between sympatric species pairs in six regions. Sister‐taxa relationships and estimates of divergence are consistent with the modified peripheral isolate model of speciation in which vicariances, range expansions and contractions, dispersals and founder events lead to isolated populations that subsequently diverge to form new species.
Interactive effects of human activities, herbivory and fire on quaking aspen (Populus tremuloides) age structures in western Wyoming
Authors: Hessl Amy E. , Graumlich Lisa J. 
Published: March 2003

AimFire suppression, elk (Cervus elaphusErxleben) browsing and drought have been suggested as possible explanations for low aspen (Populus tremuloidesMichx.) ramet regeneration in elk winter range of the Greater Yellowstone Area (GYA) during the twentieth century. This study analyses the relationship between the rates of aspen regeneration, biophysical factors and human land use since 1830. This approach reveals the importance of indirect human impacts, especially through fire and elk management strategies, on forest structure.LocationThis study was conducted in and around the winter range of the Jackson Hole elk herd in western Wyoming, USA. Aspen stands in this region represent the ecotone between coniferous forest and sagebrush‐grassland vegetation.MethodsAge structures of aspen stands were reconstructed from tree‐rings in order to determine how variation in drought, elk populations and fire occurrence may have affected aspen ramet regeneration since 1830. The effects of recent prescribed fires and elk browse on aspen regeneration were also evaluated by measuring stem height, browse intensity and age of ramets <2 m tall in prescribed burns and in unburned areas.ResultsAspen ramet regeneration has occurred consistently but at low frequencies since 1830, with three peaks of regeneration: 1860–85, 1915–40 and 1955–90. Periods of frequent ramet regeneration coincided with low to moderate elk populations and aspen regenerated only sporadically when elk populations were high. Based on a comparison of the age structures with a tree‐ring reconstruction of Palmer drought severity index (PDSI), observed PDSI and annual precipitation, drought variability appears unrelated to episodes of aspen regeneration. Recent regeneration patterns suggest that fire does not enhance the recruitment of tree‐sized aspen stems in the presence of elk browse, although sample sizes were small. Since 1900, elk hunting and spatially clustered elk feeding in the study area has facilitated low but consistent regeneration of aspen ramets in the twentieth century. In contrast, extremely low ramet regeneration has been observed in national parks of the Rocky Mountains, where elk have been managed according to the `natural regulation' policy (no hunting or feeding) since 1969.Main conclusionsOver time, different management strategies have altered the interactions between fire, herbivory and aspen regeneration suggesting that management history and the causes of change in management, should be explicitly included in ecological studies and future management strategies. These results also point to the value of using the spatial and temporal variation in human interactions with ecological systems as a method for understanding ecological relationships.
Genetic variation of the endangered holoparasiteDactylanthus taylorii(Balanophoraceae) in New Zealand
Authors: Holzapfel Sebastian , Faville Marty Z. , Gemmill Chrissen E. C. 
Published: March 2003

AimDactylanthus tayloriiHook. f. (Balanophoraceae) is an endemic, endangered root‐holoparasitic flowering plant in New Zealand. We investigated genetic variation within and among populations of the species over its entire known distribution range to study distinctness of populations, geographical distribution of genetic variation, the level of gene flow among populations and implications of the findings for conservation.LocationPopulations ofD. tayloriiwere sampled from the central, eastern and western North Island of New Zealand and from the only known population on an offshore island (Little Barrier Island) off the north‐east coast of the North Island.MethodsRandom amplified polymorphic DNA (RAPD) profiles were obtained from inflorescence samples of 146 tuber clumps in seventeen populations. We usedUPGMAcluster analysis based on Nei's genetic distance and analysis of molecular variance (AMOVA) to calculate partitioning of genetic variation within and among populations and the relationship between geographical and genetic distance.ResultsReproducible RAPD markers, including several that were specific to single populations, show that all populations sampled are unique. Populations can be grouped into two main clusters based on genetic variation, corresponding to an eastern and western distribution, respectively, and separated by the Taupo Volcanic Zone. Genetic variation is predominantly (63%) among as opposed to within populations and is not correlated with geographical distance below the regional scale.Main conclusionsResults indicate long isolation and restricted gene flow among populations, both of which are interpreted mainly as characteristics of the species rather than as results of human influence. Widespread disturbance of vegetation through repeated volcanic events, with a dominant eastern direction of ash flow and tephra formation, are seen as the likely mechanism for the regional grouping of genetic variation into two clusters. Results support the national coordination of conservation management ofD. tayloriiand identify priorities for protection. Because geographical distance is not a good indicator for genetic similarity, findings cannot be extrapolated to populations that have not been sampled; the usual concept of nearest‐provenance‐based sourcing (eco‐sourcing) of seeds for restoration may not apply to the species.
Habitat islands in fire‐prone vegetation: do landscape features influence community composition?
Authors: Clarke Peter J. 
Published: March 2003

Aim, LocationLandscape features, such as rock outcrops and ravines, can act as habitat islands in fire‐prone vegetation by influencing the fire regime. In coastal and sub‐coastal areas of Australia, rock outcrops and pavements form potential habitat islands in a matrix of fire‐prone eucalypt forests. The aim of this study was to compare floristic composition and fire response traits of plants occurring on rocky areas and contrast them with the surrounding matrix.MethodsPatterns of plant community composition and fire response were compared between rocky areas and surrounding sclerophyll forests in a range of climate types to test for differences. Classification and ordination were used to compare floristic composition and univariate analyses were used to compare fire response traits.ResultsThe rock outcrops and pavements were dissimilar in species composition from the forest matrix but shared genera and families with the matrix. Outcrops and pavements were dominated by scleromorphic shrubs that were mainly killed by fire and had post‐fire seedling recruitment (obligate seeders). In contrast, the most abundant species in the adjacent forest matrix were species that sprout after fire (sprouters).Main conclusionsFire frequency and intensity are likely to be less on outcrops than in the forest matrix because the physical barrier of rock edges disrupts fires. Under the regime of more frequent fires, obligate seeders have been removed or reduced in abundance from the forest matrix. This process may have also operated over evolutionary time‐scales and resulted in convergence towards obligate seeding traits on outcrop fire shadows. In contrast, there may have been convergence towards sprouting in the forest matrix as a result of selection for persistence under a regime of frequent fire.
The historical bridge between the Amazon and the Atlantic Forest of Brazil: a study of molecular phylogeography with small mammals
Authors: Costa Leonora P. 
Published: March 2003

Abstract Aim  To examine how the genetic diversity of selected taxa of forest‐dwelling small mammals is distributed between and within the major rain forest domains of Amazonia and Atlantic Forest and the intervening interior forests of Brazil, as inferred by the relationships between gene genealogies and geography. I also addressed the historical importance of the central Brazilian forests in connecting Amazon and Atlantic Forest populations of rodents and marsupials.Methods  I evaluated variation in the mitochondrial cytochrome b gene to estimate the levels of sequence divergence between those taxa occurring throughout the Amazon, Atlantic Forest, and forests in the Cerrado and Caatinga regions. I inferred the hierarchical relationships between haplotypes, populations and formal taxa using the cladistic approach of maximum parsimony. I compared areas and the clades identified by superimposing cladograms on the geographical distribution of samples. The degree of concordance both in phylogeny and the depth of the nodes in these phylogenies, in addition to patterns of geographical distribution of clades, permitted me to make inferences on how, when and where the taxa differentiated.Results  Sequence similarity is often greater between samples from the Atlantic Forest and either Amazon or central Brazilian forests than it is within each of the two rain forest domains. The Atlantic Forest clades are either not reciprocally monophyletic or are the sister group to all the other clades. There is some indication of northern and southern components in the Atlantic Forest. Given the geographical distribution of clades and the relatively deep levels of divergence, the central Brazilian area does not behave as a separate region but is complementary to either Amazon or Atlantic Forest. Patterns of area relationships differ across taxa, suggesting that different processes and/or historic events affected the diversification within each lineage.Main conclusions  The Amazon and the Atlantic forests are not exclusive in terms of their small mammal faunas; both overlap broadly with taxa occurring in gallery forests and dry forests in central Brazil. Central Brazilian forests are an integral part of the evolutionary scenario of lowland small mammals, playing an important role as present and past habitats for rain forest species. Therefore, representatives from this area should always be included in analyses of the evolutionary history of lowland rain forest faunas. The incongruence of branching patterns among areas is in agreement with recent results presented for Neotropical passerine birds and indicates that a single hypothesis of Neotropical area relationships is unlikely. These findings reinforce the idea that speciation in the Neotropics will not be explained by any single model of vicariance or climatic changes.
Psychiatric patients' views on the concept of self‐determination: findings from a descriptive study
Authors: Välimäki Maritta 
Published: March 2003

• Using content analysis of unstructured interviews, this study examined the views of 72 long‐term psychiatric patients on the concept of self‐determination.• The aim was to shed further light on the meaning of the concept for the purpose of developing a better tool for evaluation.• One‐third of the patients were familiar with the concept, another third had never heard of self‐determination.• The majority (52 patients) presented their views and definitions regardless of whether they had heard of the concept before.• Content analysis revealed two central aspects in the definitions: an intrapersonal aspect, with self‐determination defined in relation to the patients themselves or to their own activities; and an interpersonal aspect, with the focus on the patients' relationship with other persons.• In spite of its limitations, the study certainly adds to our understanding of the concept of self‐determination.• It demonstrates that psychiatric patients are capable of offering valuable insights into key concepts of nursing, even if they are abstract.• The results open new avenues for strengthening the self‐determination of psychiatric patients.
Nursing development units: their structure and orientation
Authors: Redfern Sally , Stevens Warren 
Published: March 2003

• This paper provides background material about the Department of Health funded Nursing Development Units (NDUs), specifically their biographical and contextual characteristics, their aims and values, and their organization of work and resources acquired.• The data were drawn from questionnaires to clinical leaders and from documentation.• The findings are summarized under five questions which address the NDUs' values and aims, their organization of work, multiprofessional working, activeness in acquiring resources and support and the effect of the host organization.• Taken as a whole, the aims match the vision of the ideal NDU specified by the pioneers of the NDU movement, and most clinical leaders subscribed to primary nursing as their preferred mode of organizing nursing work.• Multiprofessional working was a common feature and there was considerable evidence of equality in team membership status.• A small number of NDUs had been awarded grants for research and most were successful in generating income from conferences.• Nearly all had links with an academic institution.• NDUs that had the support of their Trust's management were able to market their services successfully.• Our findings indicate that many NDUs have made good progress but their clinical leaders are the first to admit that there is much more to be done.
Increasing collaboration within a multidisciplinary neurorehabilitation team: the early stages of a small action research project
Authors: Bennett  
Published: March 2003

• This paper describes how the process of action research is being used in undertaking a team‐focused, practice‐based project.• The problems that the team has previously experienced in initiating change are outlined.• An explanation is advanced as to why action research is an appropriate strategy for the team to adopt, and the early stages of the action research project are described.• This is followed by a discussion of how the outcome of such research can be generalizable from one clinical setting to another.
Nurse specialists’ perceptions of their role and function in relation to starting an adult diabetic on insulin
Authors: Sigurdardóttir Árún K. 
Published: March 2003

• The purpose of this study was to describe how diabetes nurse specialists perceived their role and function in relation to starting adult patients with insulin dependent diabetes on insulin.• Using Heideggerian hermeneutic phenomenology as a research method, six diabetes nurse specialists were interviewed and the interviews were analysed according to Colaizzi’s method of phenomenological inquiry.• Results showed that the diabetes nurses perceived their role to be composed of six themes: educator; promoter of physical skill acquisition; psychological supporter; advocate of individualized care; promoter of self‐care; ‘safeguard’ in assessing and ensuring patient safety.• These results support findings from other studies, that the diabetes nurse specialist role seems to be more complex than descriptions in the nursing literature offer.
Identifying approaches to meet assessed needs in health visiting
Authors: Cowley Sarah , Billings Jennifer Ruth 
Published: March 2003

• An action research project, based in a single fundholding practice on the south coast of England, aimed to identify the health needs of families with resident children, then use the contracting system to redirect health visiting services to meet those needs.• After assessing the health needs, it was necessary to assess the potential of a range of health visiting approaches that might be proposed to meet those needs.• This paper explains how the approaches were assessed for use in the local area and why funding for two additional, innovative posts was deemed necessary.• Despite the unsophisticated evidence base for health visiting interventions, a case can be made for commissioning particular service approaches by using a combination of survey data and results from controlled and uncontrolled service evaluations.• The supportive focus of health visitor home visiting remains an appropriate use of existing resources, but the usual intensity of visiting may be insufficient for full effectiveness. To rationalize such services by targeting them only at individuals with established needs risks an exacerbation of deteriorating health trends across an area.• Alternatively, augmenting home visiting with a community development approach to improve the adverse social environments in which families live may help to change the underlying factors that contribute to ill‐health and prove more widely cost‐effective.
Effect of education on evidence‐based care and handling of peripheral intravenous lines
Authors: Lundgren Anna , Wahren Lis Karin 
Published: March 2003

• Deficient routines in use, care, handling and documentation of peripheral intravenous vein cannulae (PIV) have previously been reported, and complications have been noted in 50–75% of the patients.• The aim of the study was to examine whether specially trained nurses change their actions to decrease complications when using cannulae.• The study included 36 nurses assigned to experimental and control groups. The experimental group followed an education programme explaining how to use and take care of a PIV.• To evaluate the intervention document analysis, observations and patient interviews were performed in 99 patients with 172 PIVs in situ for less than 24 h.• After the education programme, fewer complications, more carefully performed care and handling, and better documentation and information were found in the experimental group. Nurses in the control group followed current routines, which resulted in a greater degree of complications.• Education in evidence‐based care and handling gives nurses the opportunity to improve their ability to use theoretical knowledge in clinical problems.
The development of a collaborative stroke training programme for nurses
Authors: Dowswell George , Forster Anne , Young John , Sheard Jayne , Wright Philip , Bagley Pam 
Published: March 2003

• The effectiveness of multidisciplinary stroke rehabilitation may be enhanced by nurses and therapists adopting a single consistent approach to the positioning and mobilizing of patients. As patients can spend as little as 4% of the waking day receiving ‘therapy’ there is considerable potential for a more dynamic nursing intervention, which may contribute to improving patient care.• We aimed to investigate whether physiotherapists could step back from direct patient treatment in order to participate in a structured training programme for nurses involved with patients recovering from stroke on an established elderly care rehabilitation ward in a district general hospital.• Qualitative methods were used within a participatory action research framework to describe the development process and content of the training programme. Nursing staff, physiotherapists and their respective managers were interviewed to identify perceived training needs. This informed the structure and content of the training course and allowed insight into interprofessional working.• We found that nursing staff were highly motivated to undertake rehabilitation training and to develop a more consistent interdisciplinary approach. A course of six theoretical and practical sessions, on normal movement, positioning and transferring patients, the upper limb, and gait re‐education, was delivered to participating nursing staff over a five month period. This was supplemented by practical, informal individual patient/physiotherapist/nursing sessions. Details are provided for those wishing to replicate the course elsewhere.• In conclusion, nursing staff, physiotherapists and physiotherapy tutors participated fully in the establishment, development, delivery and review of the course. As participants in the project became committed to its aims, creative solutions were found to the practical problems which arose. The course addressed important professional issues and provided reasonable opportunities to practise skills.
Reflective narrative and dementia care
Authors: Graham  
Published: March 2003

• This study was an enquiry into how clinical supervision could enable a team of six community psychiatric nurses to provide improved patient‐centred care. It also examined how feelings of burn‐out, stress and tedium when caring for people with dementia could be relieved.• The methodology used in the study analysed the process, enabling the findings to be studied. This is new paradigm research, requiring the researcher and participants to be equal and active coenquirers into the process facilitating the enquiry.• Six community psychiatric nurses allowed their period of supervision to be recorded over six months in order to identify relevant issues of concern and resolution in their practice. It was anticipated that the experiences revealed during supervision would provide a means by which the nurses could develop their skill and knowledge and improve their care‐giving.• The findings suggest that the education of community psychiatric nurses needs to enable them to develop the ability to demonstrate emotional competence and to carry out self‐questioning.