bluuebunny/crossref_metadata_2025 huggingface dataset:
Birds of paradise, vicariance biogeography and terrane tectonics in New Guinea
Authors: Heads Michael
Published: March 2003

Aim

The subspecies of Paradisaeidae are mapped and the distribution patterns correlated with aspects of New Guinea tectonics.

Location

New Guinea, the northern Moluccas, and north‐eastern Australia.

Methods

Panbiogeographical analysis (Crawet al., 1999).

Results

Pteridophora,Loboparadisaea,Parotia carolaeand others are notably absent from the Vogelkop, Huon and Papuan Peninsulas, accreted terranes in the north and east of New Guinea. Coupled with this, putative sister taxa in each ofAstrapia,ParotiaandParadisaeashow massively disjunct affinities between the Vogelkop and Huon Peninsulas:Astrapia nigra(Vogelkop) andA. rothschildi(Huon Peninsula);Parotia sefilata(Vogelkop) andP. wahnesi(Huon); andParadisaea rubra(Western Papuan Islands by the Vogelkop) andP. guilielmi(Huon Peninsula). In the last two species the males have oil‐green throat coloration extending above the eye to cover the front of the crown, the eye is reddish‐brown not yellow, the rectrices are longer and the inner vane of the outermost primaries is not emarginate.

Main conclusions

The disjunct affinities among the accreted terranes (Vogelkop, Huon, etc.), together with the absences there of groups likePteridophora, are incompatible with usual dispersal models of New Guinea biogeography, but are compatible with recent analyses of vicariance biogeography and terrane tectonics (Michaux, 1994;Flannery, 1995;de Boer & Duffels, 1996a,b; Polhemus, 1996;Polhemus & Polhemus, 1998). Birds of paradise are sedentary forest dwellers with small home ranges and are tolerant of disturbance, and so it is suggested that populations have been caught in the dramatic geological movements (lateral and vertical) of different parts of New Guinea and this has led to fragmentation and juxtaposition of ranges, as well as altitudinal anomalies.
Spatial and temporal pattern of white spruce regeneration within mixed‐grass prairie in the Spruce Woods Provincial Park of Manitoba
Authors: Chhin Sophan , Wang G. Geoff
Published: March 2003

Aim

Thirty white spruce [Picea glauca (Moench) Voss] islands were sampled to study the temporal and spatial pattern of white spruce regeneration at its southern limit of distribution.

Location

The study was conducted within three mixed‐grass prairies in the Spruce Woods Provincial Park (SWPP) of south‐western Manitoba.

Methods

White spruce seedlings, saplings and trees were mapped and measured in relation to eight sectors and five zones delimited by four transect lines extending through the centre of each island oriented north to south, west to east, north‐west to south‐east and north‐east to south‐west.

Results

Temporal patterns of regeneration were negatively correlated with July temperature at the time of establishment and up to 30 years after establishment. Height growth of seedlings and saplings were also negatively correlated with July temperature. Seedlings, saplings and trees were concentrated on the north vs. south aspect and within 4–12 m from the island centre. Seedlings grew almost exclusively in association with creeping juniper (Juniperus horizontalis Moench).

Main conclusions

Results of the study suggest that white spruce recruitment and growth reflect past climatic variation, and microclimatic and microsite conditions promoting soil moisture retention and/or fire risk reduction facilitate white spruce germination and establishment.
Large‐scale phytogeographical patterns in East Asia in relation to latitudinal and climatic gradients
Authors: Qian Hong , Song Jong‐Suk , Krestov Pavel , Guo Qinfeng , Wu Zemin , Shen Xiansheng , Guo Xiaosi
Published: March 2003

Aim  This paper aims at determining how different floristic elements (e.g. cosmopolitan, tropical, and temperate) change with latitude and major climate factors, and how latitude affects the floristic relationships between East Asia and the other parts of the world.

Location  East Asia from the Arctic to tropical regions, an area crossing over 50° of latitudes and covering the eastern part of China, Korea, Japan and the eastern part of Russia.

Methods  East Asia is divided into forty‐five geographical regions. Based on the similarity of their world‐wide distributional patterns, a total of 2808 indigenous genera of seed plants found in East Asia were grouped into fourteen geographical elements, belonging to three major categories (cosmopolitan, tropical and temperate). The 50°‐long latitudinal gradient of East Asia was divided into five latitudinal zones, each of c. 10°. Phytogeographical relationships of East Asia to latitude and climatic variables were examined based on the forty‐five regional floras.

Results  Among all geographical and climatic variables considered, latitude showed the strongest relationship to phytogeographical composition. Tropical genera (with pantropical, amphi‐Pacific tropical, palaeotropical, tropical Asia–tropical Australia, tropical Asia–tropical Africa and tropical Asia geographical elements combined) accounted for c. 80% of the total genera at latitude 20°N and for c. 0% at latitude 55–60°N. In contrast, temperate genera (including holarctic, eastern Asia–North America, temperate Eurasia, temperate Asia, Mediterranean, western Asia to central Asia, central Asia and eastern Asia geographical elements) accounted for 15.5% in the southernmost latitude and for 80% at 55–60°N, from where northward the percentage tended to level off. The proportion of cosmopolitan genera increased gradually with latitude from 5% at the southernmost latitude to 21% at 55–60°N, where it levelled off northward. In general, the genera present in a more northerly flora are a subset of the genera present in a more southerly flora.

Main conclusions  The large‐scale patterns of phytogeography in East Asia are strongly related to latitude, which covaries with several climatic variables such as temperature. Evolutionary processes such as the adaptation of plants to cold climates and current and past land connections are likely responsible for the observed latitudinal patterns.
Continental rain forest fragments in Singapore resist invasion by exotic plants
Authors: Teo Debbie H. L. , Tan Hugh T. W. , Corlett Richard T. , Wong Choong Min , Lum Shawn K. Y.
Published: March 2003

Abstract Aim  In general, the plant communities of oceanic islands suffer more from exotic plant invasions than their continental equivalents. At least part of this difference may be contributed by differences in non‐biological factors, such as the antiquity and intensity of human impacts and the absence of internal barriers to dispersal, rather than differences in inherent invasibility. We tested the resistance of species‐rich continental rain forests to plant invasion on a small, continental island that has been subject to prolonged and intensive human impact.

Location  Singapore is a 683‐km2 equatorial island <1 km from the Asian mainland and with a population of 4 million people. It has a continental biota but has been subject to human impacts as intense as on any oceanic island.

Methods  We sampled twenty‐nine sites in seven vegetation types, ranging from urban wasteland to fragments of primary lowland rain forest. In each sample plot, all plant species were identified, exotic cover was estimated, and a range of environmental variables measured. Additional qualitative surveys for exotic invasion were made in other forest areas in Singapore. The data were analysed by Spearman's rank correlation coefficient.

Results  The number of exotic species recorded at a site was unrelated to the number of native species. Across all sites, percentage canopy opening had the highest correlation with the number of exotic species, while soil pH (which largely reflects the incorporation of calcareous construction wastes) had the highest correlation if the mangrove sites were excluded. There were no exotics in mangrove forest and only a tropical American, bird‐dispersed shrub, Clidemia hirta (L.) D. Don (Melastomataceae: Koster's Curse), in primary and tall secondary forest patches. The species‐poor early stages of woody plant succession on highly degraded soils were also very resistant to exotic plant invasion.

Main conclusions  Long‐isolated rain forest fragments in an exotic‐dominated continental island landscape resist invasion by exotic plants, suggesting that the problems on oceanic islands may reflect an inherently greater invasibility. This study also adds to the increasing evidence that the floras of tropical rain forest fragments in South‐east Asia are remarkably resilient on a time‐scale of decades to a century or more.
Plant collecting spread and densities: their potential impact on biogeographical studies in Thailand
Authors: Parnell J. A. N. , Simpson D. A. , Moat J. , Kirkup D. W. , Chantaranothai P. , Boyce P. C. , Bygrave P. , Dransfield S. , Jebb M. H. P. , Macklin J. , Meade C. , Middleton D. J. , Muasya A. M. , Prajaksood A. , Pendry C. A. , Pooma R. , Suddee S. , Wilkin P.
Published: March 2003

AimsTo produce representative aggregate maps of plant collection locations in Thailand and discuss their impact on biogeographical studies in Thailand and the surrounding region.

LocationThailand.

MethodsA representative data set comprising 6593 plant specimen records for Thailand has been assembled. The data set contains ± all known collections for fifteen representative plant families and further records for another 104. All records are localized to Changwat (province), 6441 to at least quarter degree square.

ResultsAnalysis shows that the spread of collecting activity in Thailand is markedly uneven; 20% of collections come from a single Changwat (Chiang Mai) and 53% of Changwat have fifty or fewer collections. The distribution of collections by Changwat and by quarter degree square is erratic with most squares and Changwat having few collections, both in proportionate and absolute terms. Some of the most densely forested Changwats and squares appear undercollected. Distribution maps for common, easily recognized tree species in the genusSyzygiumshow distributional gaps.

ConclusionsThailand is defined as an undercollected country. Even within the few well‐collected quarter degree squares the spread of collecting is still poor; almost all collections being localized to one of three mountain ranges or their foothills. There are many gaps in collecting activity which make impossible a straightforward interpretation of biogeographical pattern. It is argued that targeted collecting activity is needed, that assembly of this type of data set is therefore essential and that our data set and its interpretation is a model for all countries in the region.
Developing an audit tool for primary nursing
Authors: RYAN ASSUMPTA A. , LOGUE HUGH F.
Published: March 2003

• Despite the proliferation of research on primary nursing, most studies have investigated the effects of primary nursing on quality of care, job satisfaction and collegial relationships.

• Few researchers have attempted to isolate the key dimensions of primary nursing in an observable and measurable form.

• The purpose of this exploratory study was to devise an audit tool for primary nursing that builds on Mead's research and incorporates views of patients/clients, relatives, nurses and other members of the multidisciplinary team.

• Preliminary findings suggest that the audit is a useful indicator of the extent to which the crucial elements of primary nursing are present or absent in any clinical setting.

• Furthermore it suggests that while many wards claim to practise primary nursing there is a considerable variation in the extent to which this is actually carried out.
Priorities for mental health and learning disability nurse education in the UK: a case study
Authors: NORMAN IAN J.
Published: March 2003

• The closure of psychiatric and mental handicap hospitals, the emphasis on community rather than hospital care and the distinction between health and social care for people in the community, with its funding implications, have demanded that mental health and learning disability nurses face the challenges of developing new skills and new ways of working.

• In this paper the findings of a study funded by the English National Board for Nursing, Midwifery and Health Visiting (ENB) are reported. This study explored the impact of these reforms on nurses and their practice, and identified the educational needs of mental health and learning disability nurses that have changed as a result.

• The study took a multiple‐case study approach and involved interviews with 22 `key informants' and 88 mental health and 59 learning disability stakeholders in six sites, three in each nursing specialty.

• Inductive analysis of the interview data revealed 20 categories which summarize the major issues facing the two nursing specialties.

• These categories are discussed under seven themes and issues for nurse education are raised.
Latex allergy: how to identify it and the people at risk
Authors: BOWYER REBECCA V. ST. L.
Published: March 2003

• Some patients and staff are more at risk to latex allergy than others.

• This paper identifies those people and the ways in which their allergy can be confirmed.

• Recommendations are made for their care and to prevent sensitization occurring.
The psychological impact of working in emergencies and the role of debriefing
Authors: ROBBINS IAN
Published: March 2003

• It has been suggested that there are three major disasters each week world‐wide of such a magnitude that local services are overwhelmed.

• Nurses are frequently involved in assisting in emergencies.

• This paper reviews current work looking at the impact of working in emergency settings and overseas humanitarian aid work.

• There is evidence that being at a disaster site or overseas humanitarian operation can be psychologically damaging.

• Strategies aimed at reducing this damage, such as debriefing, are poorly evaluated but often carried out as an act of faith.

• This is an area that needs to be addressed as nurses will increasingly be involved in this work.
Blood transfusion from the recipient’s perspective
Authors: Fitzgerald Mary , Hodgkinson Brent , Thorp Dawn
Published: March 2003

• This paper reports on an interpretative research study that set out to develop a rich description of patients’ experiences of the process of preparing for and receiving a blood transfusion.

• The themes of information‐giving and receiving; reactions, both physical and emotional; and the care and treatment participants received through the experience are presented.
Oral health status of psychiatric patients
Authors: Sjögren Reet , Nordström Gun
Published: March 2003

• Many patients suffering from long‐term psychiatric illness are on medication for long periods. These medications frequently cause xerostomia leading to an increased risk of caries, gingivitis, periodontitis and stomatitis.

• Oral hygiene is therefore of the utmost importance for these patients. Nurses interact with patients on a daily basis, and therefore they are the psychiatric care‐givers of choice to support these patients.

• The main aim of this study was to describe the oral health status of patients in short‐term and long‐term psychiatric care by means of oral assessment. A second aim was to discover whether the assessment guide used could distinguish any differences between these two groups.

• A modified version of the Oral Assessment Guide (OAG) developed by Eilers et al. (1988)
was used. In addition, new items/categories were developed, forming the Oral Assessment Guide for Psychiatric Care (OAG‐PC). A total of 57 patients in psychiatric care, short‐term (n=32) and long‐term (n=25), were assessed by the OAG‐PC.

• Patients in long‐term psychiatric care had significantly higher scores on the total OAG‐PC compared with those in short‐term psychiatric care, indicating a worse oral health status. Statistically significant differences were also found in relation to the following OAG‐PC categories: odour from the mouth, mucous membranes, gums, teeth or dentures, calculus on teeth and appearance of teeth.

• Further research should be focused on the difficulties for nurses in approaching their patients in order to perform oral care and on evaluating the effect of teaching and training psychiatric nurses in oral care, preferably with the assistance of the OAG‐PC.

• This assessment guide may thereby also be valuable for nurses’ documentation in estimating, planning, implementing and evaluating their psychiatric patients’ oral care needs.
The public health problem of acute respiratory illness in childcare
Authors: McCutcheon Helen , Fitzgerald Mary
Published: March 2003

• Acute respiratory illness continues to be a significant problem for children attending childcare.

• The problems for the child are in terms of prevalence, incidence, and quality of life.

• Additional costs relate to parental absence from work and loss of earnings.

• This paper reports on the literature, and notes that little research has been undertaken to determine whether there are long‐term risks or benefits to experiencing acute respiratory illness in early childhood.

• Research to date is presented, and the role of public health nurses is discussed in relation to how they might assist in reducing the incidence/prevalence of acute respiratory illness in children attending childcare.
Effects of normal saline on endotracheal suctioning
Authors: Akgül Sevim , Akyolcu Neriman
Published: March 2003

•  This study was designed to determine the effects of saline solution administered prior to endotracheal suctioning by nurses working in intensive care on oxygenation, heart rate and long‐term pulmonary hygiene.

•  The study was carried out on an experimental basis in the Intensive Care Unit of a university hospital in Turkey. A total of 20 patients were included, who were mechanically ventilated because of pulmonary or cardiovascular problems or trauma.

•  Data were collected using a data form. Each patient was monitored for 5 minutes following suctioning with or without saline solution and findings of heart rate, SpO2, and blood gas measurements were recorded. Data were analysed using percentage calculations, the student's t‐test and the Friedman test.

•  The study showed that most of the patients were between 60 and 69 years and were intubated because of respiratory insufficiency.

•  Evaluation of blood gases following suctioning with or without saline solution showed partial decreases in pO2, pCO2, HCO3, and oxygen saturation (SaO2), which did not reach a significant level.

•  No significant difference was found between pH levels recorded prior to and 5 minutes after suctioning without saline solution; however, the increase in pH following suctioning with saline solution was significant.

•  Patients undergoing suctioning with saline solution exhibited significantly increased heart rates in the fourth and fifth minutes, whereas no increases were detected in these undergoing suctioning without saline solution. SpO2 values obtained by pulse oxymeter did not show significant differences.

•  Saline solution administered with suctioning resulted in undesirable, although not significant, alterations in oxygen saturation and arterial blood gas levels.
Assessing student nurse clinical competency: will we ever get it right?
Authors: Dolan Gina
Published: March 2003

• In 1997, a revised system was introduced at the University of Glamorgan, Wales, to assess student nurse clinical competency. This was firstly as a result of concerns that the previous system was based on limited documentary evidence, and, secondly as the Welsh National Board for Nursing and Midwifery issued new competency statements.

• This article reports an evaluative research study which aimed to determine whether the revised system was an effective measure of clinical competency.

• A series of focus groups were conducted with students, tutors and clinical preceptors to discuss their experiences of using the revised system. A content analysis was conducted of all evidence written by students to support the achievement of clinical competency.

• The findings of the focus groups indicated that each group had some initial problems with the assessment process. The main concern for all groups was lack of consistency and uncertainty in the assessment process. Although the introduction of written evidence to support clinical competency was welcomed, many felt that too much evidence was required.

• Content analysis of competency documentation aimed to compare student evidence and to determine whether there were inconsistencies in the assessment process.

• There were many variations in the evidence obtained from students, in particular the amount of evidence written by each student.

• The findings clearly indicate that further revisions are necessary to ensure that the system is implemented in the most effective way.

• The Fitness for Practice report (UKCC, 1999) has ensured that competency‐based assessment is here to stay in the UK. Evaluative research of this type is important to ensure that we adopt the most suitable approach to assessing clinical competency.
District nurses' experiences of providing care in residential care home settings
Authors: Goodman Claire , Woolley Rosemary , Knight Denise
Published: March 2003

• Little research describes the involvement and contribution of primary health care services in residential homes, despite policy and research concerns that older people in residential homes are a vulnerable population for whom care must be improved.

• The aim of this research was to explore the actual and potential contribution of primary care nurses in residential homes for older people, particularly district nurses.

• Five focus groups were held with district nurses in one county in England, to explore how participants represented their views, values and experiences of working in residential homes.

• Our major finding was the importance of context in shaping the experience of district nursing involvement. General practitioner attachment determined the frequency of visiting homes and affected workload. District nurses had regular contact with residential homes for discrete nursing tasks, but appropriateness of referrals and input was not agreed.

• The focus group discussions with district nurses revealed how problematic their work in residential homes was and a lack of consensus about their role. The data suggested that uncertainty about providing care in a setting that straddles the health and social care, public and private divide, and anxieties about managing their workload overshadowed their acknowledged concerns about the older people in residential care homes. Further research is needed to substantiate the findings, obtain residents' views and address issues of how to achieve integrated and equitable health and social care for this group.
Video home training as a method of supporting family life control
Authors: Häggman‐Laitila Arja , Pietilä Anna‐Maija , Friis Leila , Vehviläinen‐Julkunen Katri
Published: March 2003

• The purpose of this study was to describe video home training as a method of early support in problems of family life control.

• Answers were sought to the following questions: how does a family counsellor use video home training to support families' own resources and family life control, and what are the uses and benefits of video home training from parents' perspective?

• The data consisted of the videotaped counselling sessions and family service plans for five families, and were analysed using the general method of analysing photographs and video material developed by anthropologist‐photographers.

• Video home training as a method in supporting family life control consisted of goal‐orientated reflection by parents on videotaped episodes of their everyday family life under the guidance of a family counsellor. The process of videotaping family life, in‐depth analysis of the videotapes, recognition of instances of successful interaction, and search for new alternatives gave participants a feeling that it would be possible for them to make their everyday life fluent and functional.

• The findings show that video home training helped the families to gain better control over their family life.
Interactive multimedia and concrete three‐dimensional modelling
Authors: Baxter J. H. , Preece P. F. W.
Published: March 2003

A multimedia package for teaching about the phases of the moon to Year 8 (12‐year‐old) students was compared with a conventional three‐dimensional modelling approach. Both methods were highly and equally effective in terms of student learning, and the effectiveness of the multimedia package did not depend on a student’s experience of computers or attitude towards computers. The package was also equally effective for male and female students.
Back to the cave or playing away? Gender roles in home‐from‐home environments
Authors: Chaplin Davina
Published: March 2003

Abstract: This paper theorizes the gender roles that are played out in the alternative spaces acquired by purchasers of second homes in foreign rural environments. These homes are often constructed by their owners (both men and women) as bolt‐holes, simple places of escape from normal routines; the lived reality is that they become arenas in which men often play at cave‐building or peasant‐style farming, while women find a different context for creative home‐making, shopping and socializing, and the caring ethic of being involved with children, grandchildren and visitors. Both genders are freed from the constraints of their normal working lives, but the ambivalent nature of the context which is both home and holiday is one in which work is present, in the form of do‐it‐yourself or doing the domestic, while at the same time it provides opportunity for forms of ludic behaviour. Drawing from a series of unstructured interviews, I examine the consumption practices of second home owners and analyse the ways in which informants reflect on their activities and identities. The home‐and‐yet‐away context allows the experiences and meanings of home and away from home to be explored from both genders’ perspectives, leading to conclusions about the dynamics of gender relationships in situations that combine routine and novelty.
Personal vs. non‐personal sources of information used in the purchase of men’s apparel
Authors: Kinley Tammy L. , Conrad Raig A. , Brown Gene
Published: March 2003

This study identifies and examines the relationship between several segmentation variables and the personal and promotional (non‐personal) cues used in the information‐gathering step of the purchase decision process. In the context of this study, personal cues refer to family members, coworkers and friends. Promotional or non‐personal cues refer to magazine advertisements, television advertisements, store displays and salespersons. Information regarding the use of personal and promotional cues was gathered from a national, random sample of 440 male consumers. The study found that adult male consumers report using promotional cues more frequently than personal information sources.
The effect of linear density of polyamide filaments on the comfort and performance of ladies hosiery
Authors: Byrne M.S. , Carty P. , Scriven K.
Published: March 2003

This study used 49 female consumers, to investigate the effect of variation in the linear density of polyamide filaments used in the construction of ladies opaque tights, on a range of comfort and performance factors. Two sets of tights were used. Each set consisted of three types of tights manufactured from micro, semi‐micro and conventional filaments respectively. The first set incorporated Lycra in alternate courses while the second set incorporated Lycra in every course. The hosiery was assessed by means of a number of ranking and rating scales after having been worn and washed five times. The tights made from micro and semi‐micro filaments were generally much preferred to those made from conventionally thicker filaments. The differences between the perceptions of tights made from the micro and semi‐micro filaments were small, and there appears little to be gained by using the lowest linear density micro filaments. Consumers preferences with regard to overall comfort agreed closely with preferences emerging from initial handle assessments. The hypothesis is advanced that for clothing worn next to the skin handle assessments could obviate the need for more expensive, time consuming and lengthy wearer trials.
Altitudinal and seasonal variation of frost resistance of Fagus crenata and Betula ermanii along the Pacific slope of Mt. Fuji, Japan
Authors: Gansert DirK. , Backes Katharina , Kakubari Yoshitaka
Published: March 2003

1 Frost resistance of Fagus crenata (Siebold’s beech) and Betula ermanii (Japanese mountain birch) was investigated with respect to the species’ altitudinal distribution on the Pacific slope of Mt. Fuji from 1996 to 1997. Flint’s Index of Injury, which is based on electrolyte leakage from freeze‐injured tissue, was used to assess frost hardiness of shoots produced in the previous growing season.

2
Fagus crenata is found on the lower slopes (700–1600 m a.s.l.). Mid‐ to late November hardening of shoots was enhanced, midwinter damage below −30 °C reduced and dehardening delayed nearer the upper limit. To here temperatures began to rise at least 3 weeks before dehardening began. Shade crown shoots were more susceptible to deep‐freeze damage than light crown shoots. If the ultimate upper distribution limit was determined by frost hardiness, F. crenata would be expected to occur up to 1800 m altitude.

3
Betula ermanii is found between 1600 m and 2800 m, and intensive hardening occurred at all altitudes during the second half of October. Frost hardiness increased considerably with altitude up to the forest limit, where frost acclimation preceded the temperature decline by 2 weeks. Once maximum frost resistance had been attained freezing to −47 °C failed to cause tissue injury. Dehardening began slightly later at the tree line, but the time–course was the same at all altitudes. Main and lateral shoots did not differ in frost hardiness.

4 Comparison of monthly air temperature minima over the past 66 years with the course of frost resistance showed that F. crenata and B. ermanii found on the Pacific slope of Mt. Fuji were unlikely to suffer damage by frost.

5 The observed uppermost distribution limit for B. ermanii at 2800 m altitude on Mt. Fuji is considered both with our observations and with previous hypotheses.
Species‐specific spatial pattern of below‐ground plant parts in a montane grassland community
Authors: Pecháčková Sylvie , During Heinjo J. , Rydlová Věra , Herben Tomáš
Published: March 2003

1 We investigated the fine‐scale below‐ground distribution of plant parts in a mountain grassland. Roots and rhizomes were identified to the species level by tracking their connections to above‐ground parts.

2 Fine‐scale horizontal heterogeneity of total root and rhizome biomass at different depths was recorded at the same time in the same grassland.

3 Both pairwise and multivariate statistical analysis showed that in the 0–3 cm layer the frequencies of roots and rhizomes of individual plants were closely coupled to the occurrence of the same species immediately above‐ground. In contrast, in the 3–6 cm layer, these correlations peaked when root and rhizome frequencies were compared with plants above‐ground displaced by a horizontal distance of 2 cm. This confirms the predominantly inclined growth of both roots and rhizomes; while the inclined growth has been shown regularly by studying single plants, the current study shows its prevalence at the community level as well.

4 The similarity to the above‐ground patterns in the upper soil layer was due to the spatial constraints of plant presence above‐ground; in contrast, the spatial patterns in the 3–6 cm layer were independent of plant presence above‐ground. The role of root growth plasticity is discussed in this context.

5 Autocorrelation analysis of the root data revealed that there was a pronounced difference in the grain of horizontal spatial pattern between total root biomass and species‐specific root frequencies. All the species had rather loose root systems and clumps of one species rarely extended more than 0.5 cm. In contrast, there was significant long‐range clumping of root biomass up to 10 cm. The below‐ground heterogeneities in overall biomass and in species‐specific distributions were therefore probably determined by different environmental processes.

6 No such difference in clumping range between total biomass and species‐specific frequencies was observed in above‐ground parts. This was attributed to homogeneity of the above‐ground resource (light) compared with the inherently heterogeneous nature of the below‐ground resources, and the different nature of competition for these resources may account for differences in vegetation patterns above‐ and below‐ground.
Effects of the past and the present on species distribution: land‐use history and demography of wintergreen
Authors: Donohue Kathleen , Foster David R. , Motzkin Glenn
Published: March 2003

1 Past land use can have long‐term effects on plant species’ distributional patterns if alterations in resources and environmental conditions have persistent effects on population demography (environmental change) and/or if plants are intrinsically limited in their colonization ability (historical factors).

2 We evaluated the role of environmental alteration vs. historical factors in controlling distributional patterns of Gaultheria procumbens, a woody, clonal understorey species with a pronounced restriction to areas that have never been ploughed, and near absence from adjoining areas that were ploughed in the 19th century. The demographic study was conducted in scrub oak and hardwood plant communities on an extensive sand plain, where it was possible to control for the effect of variation in environment prior to land use.

3 The observed demographic effects were contrary to the hypothesis that persistent environmental alteration depressed demographic performance and limited the distribution of G. procumbens. We observed no overall effect of land‐use history on stem density, stem recruitment or flower production. In fact, some aspects of performance were enhanced in previously ploughed areas. Populations in previously ploughed areas exhibited less stem mortality in scrub oak transitions, an increase in germination, seedling longevity and proportion of potentially reproductive stems in both plant communities, a trend for slower observed rates of population decline in both plant communities, and a higher projected rate of population growth in the scrub oak transitions. Thus, particularly in scrub oak communities, the lower abundance of G. procumbens in formerly ploughed than in unploughed areas contrasted with its performance.

4 The limited occurrence of G. procumbens in formerly farmed areas was explained instead by its slow intrinsic growth rate, coupled with limited seedling establishment. Lateral population extension occurred exclusively through vegetative growth, allowing a maximum expansion of 43 cm year−1.

5 We conclude that inherent limitations in the colonizing ability of some plant species may present a major obstacle in the restoration or recovery of plant communities on intensively disturbed sites, even in the absence of persistent environmental effects that depress population growth.
Canopy seed banks in Mediterranean pines of south‐eastern Spain: a comparison between Pinus halepensis Mill., P. pinaster Ait., P. nigra Arn. and P. pinea L.
Authors: Tapias Raúl , Gil Luis , Fuentes‐Utrilla Pablo , Pardos José A.
Published: March 2003

Canopy seed banks were analysed in post‐fire stands of Pinus halepensis, P. pinaster, P. nigra, and P. pinea. We determined age when flowering begins, age of first cone bearing, presence of serotinous cones and cone‐opening temperatures.

By 15 years after the fire, P. halepensis had developed a large canopy seed bank (3–100 × 104 seeds ha−1). Fruiting started at 5 years of age. More than 86% of the cones were serotinous and had opening temperatures from 49.3 to 51.3 °C. Cones from adult trees opened at lower temperatures than those from young trees.

A 16‐year‐old P. pinaster stand had a smaller seed bank (12 000 viable seeds ha−1) and a lower percentage of serotinous cones (66.7%), with lower cone‐opening temperature (45.8 ± 0.8 °C) and later first fruiting (12 years) than any of our three P. halepensis populations.

Populations of P. nigra and P. pinea did not show any fire adaptations: flowering was insignificant even 15 years after fire, and none of the cones produced were serotinous.

Serotinous cones represent a fire‐survival strategy for P. halepensis and P. pinaster. Early flowering is also necessary for successful post‐fire colonization in species or populations where crown fires are frequent. Late flowering and non‐serotinous cones of P. nigra and P. pinea suggest that they may have evolved where ignition leads only to low intensity ground fires.
Multiple scale composition and spatial distribution patterns of the north‐eastern Minnesota presettlement forest
Authors: Friedman Steven K. , Reich Peter B. , Frelich Lee E.
Published: March 2003

Bearing tree data were used to characterize the composition and spatial structure of the southern boreal presettlement forest in north‐eastern Minnesota, United States of America. Data collected during the General Land Office Survey (GLO) between 1853 and 1917, represents 35 324 samples (each with 1–4 trees) in a 3.2 million‐hectare landscape. Nine tree species contributed at least 1% to the overall composition. Individuals of white pine and red pine were larger than all other species and represented 9% of the tree population, while accounting for 27% of the standing basal area. Black spruce, paper birch and larch, the three most abundant species, collectively accounted for 51% of the population and 38% of the basal area.

Eight physiographic zones were characterized by differences in glacial histories, geological surfaces, soil complexes and topographic properties, and supported different compositional mixes of the nine important species.

Fifty‐six per cent of all four‐tree plots had three or four individuals of a single species. This level of conspecific aggregation is an order of magnitude greater than would be expected based on a random distribution of the same population of trees and species. Jack pine had the greatest plot‐scale aggregation, with 45% of all plots containing jack pine trees having three or four jack pine individuals. Jaccard association of similarity values of species co‐occurrence ranged from less than 0.05 to 0.24, indicating limited plot–scale interspecific associations.

Landscape spatial patterns of the species were measured at two spatial scales, 1–10 km and from 5 to 50 km. Conspecific autocorrelation patterns were positive while interspecific autocorrelation patterns tended to be either neutral or negative. Hence, plots dominated by any given species tended to spatially aggregate near other such plots, out to substantial distances.

Forest tree spatial patterns reflect complex fine to landscape‐scale relationships involving environmental factors, disturbance events and regeneration strategies. Management and long‐term conservation of forest landscapes should consider multiscale patterns in order to re‐establish forest structural properties eliminated following the disruption of natural disturbance processes.
Effects of disturbance on germination and seedling establishment in a coastal prairie grassland: a test of the competitive release hypothesis
Authors: Jutila Heli M. , Grace James B.
Published: March 2003

1 We evaluated the responses of native grassland sods to a variety of types of disturbance in order to assess hypotheses about the competitive effects of established vegetation on seed germination and seedling establishment. In particular, we consider whether germination is more responsive to the magnitude and duration of vegetation removal (competitive release) or to individual disturbance types (specific effects).

2 Field‐collected sods of coastal tallgrass prairie were subjected to no manipulation, cutting with clippings left, cutting with clippings removed (hayed), burning, and complete destruction of established vegetation under greenhouse conditions. The emergence and fate of seedlings, as well as light penetration through the canopy, were followed for a period of 4.5 months.

3 Total seedling emergence increased from cut to control, hayed, burned and plants‐removed treatments. Several periods of increased seedling emergence suggested responses to both light penetration and seasonal change.

4 Species richness was lowest in cut sods and highest in sods that had plants removed or were burned. Rarefaction analysis showed that these differences were largely those expected from differences in seedling number, except for the cut treatment, which produced fewer species per seedling than other treatments.

5 Indicator species analysis and ordination methods revealed that seedling community composition overlapped strongly across all treatments, although the area of ordination space did increase with increasing numbers of seedlings.

6 Overall, most of the effects of disturbance could be explained by cumulative light penetration to the soil surface, an indicator of total competitive release, although a few specific effects could be found (particularly for the cutting treatment). Thus, these results generally support the competitive release hypothesis.
Population dynamics of Zea diploperennis, an endangered perennial herb: effect of slash and burn practice
Authors: Sánchez‐Velásquez Lázaro R. , Ezcurra Exequiel , Martínez‐Ramos Miguel , Álvarez‐Buylla Elena , Lorente Rogelia
Published: March 2003

Zea diploperennis is a wild relative of maize that is endemic to the Sierra de Manantlán Biosphere Reserve in Mexico. Because this species is a priority for conservation in the reserve, the effects on its populations of the most common types of anthropogenic disturbance – slash‐and‐burn, and slash without subsequent burning – were investigated in three populations for 5 years.

The patterns of establishment and mortality were similar in all populations studied. Numbers of ears and fruits produced were significantly higher when disturbances were applied.

Because permanence is the most important stage in contributing to λ, the results suggest that the first genets to become established have an advantage over newly recruited plants.

When the two disturbance types were applied, λ was close to 1 or > 1. After the first disturbance, λ increased by almost 100%. In almost all situations, with or without disturbance, the persistence loops of Z. diploperennis are the most important life history pathways in the relative contribution to λ. In general, when λ increases, sexual growth loops also increase in importance, and persistence loops decrease. Changes in λ are not related to changes in vegetative growth loops.

If populations of Z. diploperennis are not disturbed at least once every 5 years, then species will go locally extinct in the wild.
Pulp handling by vertebrate seed dispersers increases palm seed predation by bruchid beetles in the northern Amazon
Authors: Silvius Kirsten M. , Fragoso José M. V.
Published: March 2003

The simultaneous use of fruits and seeds by invertebrate seed predators and vertebrate seed dispersers produces complex ecological interactions that reduce the predictability of seed fate.

Cocosoid palm seeds in the Neotropics are subject to high mortality by bruchid beetle infestation and such attack is the major cause of mortality for seeds of the palmAttalea maripaat our study site in the northern Brazilian Amazon.

The exocarp and mesocarp of 1400 fruits were manipulated in different ways to simulate handling by vertebrates. No eggs of the bruchid beetle,Pachymerus cardo, were laid on intact control fruits, while the highest numbers of eggs were received by fruits whose exocarp and mesocarp had been partially removed, as if by primates and rodents (mean of 15.9 and 18.9 eggs fruit−1, respectively, during the peak fruiting season). Fruits with intact mesocarp but no exocarp, and fruits with all mesocarp and exocarp removed, received low numbers of eggs (mean of 4.6 and 6.6 eggs per fruit, respectively, during the peak fruiting season). Thus both exocarp and mesocarp deter oviposition, and removal of these fruit structures increases fruit susceptibility to infestation.

Oviposition rates declined as the fruiting season progressed, but oviposition preferences remained the same. Seed mortality was high for any fruit on which eggs were laid.

Large rodents and primates, which have been considered among the most effective seed dispersers for large‐seeded Neotropical trees such as palms, actually increased the susceptibility of seeds to bruchid beetle attack. Removal of (intact) seeds by other dispersers may be necessary to ensure seed survival.

These results indicate that the reliability of seed dispersers cannot be gauged without a complete understanding of variables that affect seed viability.
Improving the utilization of clinical laboratory tests
Authors: Wu Alan H. B.
Published: March 2003

Reimbursement policies for health care services are greatly diminishing in the U.S. and Western Europe. Hence, there is an increasing need for doctors and other care givers to reduce costs without compromising the quality of the care being delivered. The clinical laboratory is viewed as an area of high costs where significant reductions have been targeted. Efficient utilization of laboratory services can be achieved by elimination of the general health panel, removal of old tests or those that provide redundant information, a reduction in the use of standing orders, more judicious use of drug assays, acceptance of clinical practice guidelines, and use of reflex testing algorithms. New technologies such as DNA probes can substantially improve diagnostic efficiency. Point‐of‐care testing devices which have higher costs than incremental central laboratory expenses should only be used if they reduce overall operating expenses. Implementation of expert systems can make remaining tests more effective. Doctors and laboratorians must collaborate to achieve more efficient utilization practices.
On the scientific inference from clinical trials
Authors: Holmberg L. , Baum M. , Md H. O. Adami
Published: March 2003

We have not been able to describe clearly how we generalize findings from a study to our own ‘everyday patients’. This difficulty is not surprising, since generalization deals with how empirical observations are related to the growth of scientific knowledge, which is a major philosophical problem. An argument, sometimes used to discard evidence from a trial, is that the patient sample was too selected and therefore not ‘representative’ enough for the results to be meaningful for generalization. In this paper, we discuss issues of representativeness and generalizability. Other authors have shown that generalization cannot only depend on statistical inference. Then, how do randomized clinical trials contribute to the growth of knowledge? We discuss three aspects of the randomized clinical trial ( Mant 1999), First, the trial is an empirical experiment set up to study the intervention on the question as specifically and as much in isolation from other – biasing and confounding – factors as possible (
Rothman & Greenland 1998). Second, the trial is set up to challenge our prevailing hypotheses (or prejudices) and the trial is above all a help in error elimination (
Popper 1992). Third, we need to learn to see new, unexpected and thought‐provoking patterns in the data from a trial. Point one – and partly point two – refers to the paradigm of the controlled experiment in scientific method. How much a study contributes to our knowledge, with respect to points two and three, relates to its originality. In none of these respects is the representativeness of the patients, or the clinical situations, crucial for judging the study and its possible inferences. However, we also discuss that the biological domain of disease that was studied in a particular trial has to be taken into account. Thus, the inference drawn from a clinical study is not only a question of statistical generalization, but must include a jump from the world of experiences into the world of reason, assessment and theoretical judgement.