bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbon sequestration in arid‐land forest
Authors: GRÜNZWEIG J. M. , LIN T. , ROTENBERG E. , SCHWARTZ A. , YAKIR D.
Published: May 2003

Rising atmospheric CO2 concentrations may lead to increased water availability because the water use efficiency of photosynthesis (WUE) increases with CO2 in most plant species. This should allow the extension of afforestation activities into drier regions. Using eddy flux, physiological and inventory measurements we provide the first quantitative information on such potential from a 35‐year old afforestation system of Aleppo pine (Pinus halepensis Mill.) at the edge of the Negev desert. This 2800 ha arid‐land forest contains 6.5 ± 1.2 kg C m−2, and continues to accumulate 0.13–0.24 kg C m−2 yr−1. The CO2 uptake is highest during the winter, out of phase with most northern hemispheric forest activity. This seasonal offset offers low latitude forests ∼10 ppm higher CO2 concentrations than that available to higher latitude forests during the productive season, in addition to the 30% increase in mean atmospheric CO2 concentrations since the 1850s. Expanding afforestation efforts into drier regions may be significant for C sequestration and associated benefits (restoration of degraded land, reducing runoff, erosion and soil compaction, improving wildlife) because of the large spatial scale of the regions potentially involved (ca. 2 × 109 ha of global shrub‐land and C4 grassland). Quantitative information on forest activities under dry conditions may also become relevant to regions predicted to undergo increasing aridity.
Projected climate change effects on Rocky Mountain and Great Plains birds: generalities of biodiversity consequences
Authors: PETERSON A. TOWNSEND
Published: May 2003

Climate change effects on biodiversity are already manifested, and yet no predictive knowledge characterizes the likely nature of these effects. Previous studies suggested an influence of topography on these effects, a possibility tested herein. Bird species with distributions restricted to montane (26 species) and Great Plains (19 species) regions of central and western North America were modeled, and climate change effects on their distributions compared: in general, plains species were more heavily influenced by climate change, with drastic area reductions (mode 35% of distributional area lost under assumption of no dispersal) and dramatic spatial movements (0–400 km shift of range centroid under assumption of no dispersal) of appropriate habitats. These results suggest an important generality regarding climate change effects on biodiversity, and provide useful guidelines for conservation planning.
Functional ecology of shrub seedlings after a natural recruitment event at the Nevada Desert FACE Facility
Authors: HOUSMAN DAVID C. , ZITZER STEPHEN F. , HUXMAN TRAVIS E. , SMITH STANLEY D.
Published: May 2003

Seedling recruitment is an important determinant of community structure in desert ecosystems. Positive photosynthetic growth and water balance responses to increasing atmospheric carbon dioxide (CO2) concentrations ([CO2]) are predicted to be substantial in desert plants, suggesting that recruitment could be stimulated. However, to date no studies have addressed the response of perennial plant recruitment in natural populations of desert shrubs exposed to elevated [CO2]. In April 1997, we employed Free‐Air Carbon Dioxide Enrichment (FACE) in order to increase atmospheric [CO2] in an undisturbed Mojave Desert ecosystem from ambient (∼∼ 370 µmol mol−1) to elevated CO2 (∼∼ 550 µmol mol−1). From 1997 to 2001 we seasonally examined survival, growth, gas exchange and water potential responses of Larrea tridentata and Ambrosia dumosa seedlings that germinated in Fall, 1997. Recruitment densities were not influenced by [CO2] in either species, although a two‐fold higher adult Ambrosia density under elevated [CO2] resulted in two‐fold higher seedling density (0.87 vs 0.40 seedlings m−2). Mortality was greatest for both species during the first summer (1998), despite above‐average rainfall during the previous Winter–Spring. A significant [CO2] × time interaction revealed that early survival was greater under elevated CO2, whereas a significant species time interaction revealed that overall survival was greater for Ambrosia (28%) than for Larrea (15%), regardless of [CO2]. Microsite (understorey or interspace) alone had no significant influence on survival. Significant species, microsite and species × microsite effects on growth (seedling height, stem diameter and canopy size) were found, but elevated CO2 had minimal impact on these parameters. Photosynthetic rates (Asat) for both species were higher at elevated [CO2] during certain seasons, but not consistently so. These results suggest that increased atmospheric [CO2] may enhance carbon (C) assimilation and survival of aridland perennial shrubs during favourable growing conditions, but that it may not counteract the effects of prolonged drought on mortality.
Fluctuations of Vanessa cardui butterfly abundance with El Niño and Pacific Decadal Oscillation climatic variables
Authors: VANDENBOSCH ROBERT
Published: May 2003

Annual 4th of July Butterfly Count data spanning more than 20 years are examined to explore Vanessa cardui (Painted Lady) population fluctuations with ENSO (El Niño) and Pacific Decadal Oscillation (PDO) indices. California, Colorado and Nebraska censuses exhibit a strong positive correlation with the strong El Niño events of 1982–1983 and 1997–1998 and the weaker event of 1991–1992. Regression analysis shows the population fluctuations are strongly coupled to climate variations on both short (El Niño) and longer (Pacific Decadal Oscillation) time scales. Recognizing the sensitivity to these time scales is important for predicting longer‐term global climate change effects.
Environmental control of fine root dynamics in a northern hardwood forest
Authors: TIERNEY GERALDINE L. , FAHEY TIMOTHY J. , GROFFMAN PETER M. , HARDY JANET P. , FITZHUGH ROSS D. , DRISCOLL CHARLES T. , YAVITT JOSEPH B.
Published: May 2003

Understanding how exogenous and endogenous factors control the distribution, production and mortality of fine roots is fundamental to assessing the implications of global change, yet our knowledge of control over fine root dynamics remains rudimentary. To improve understanding of these processes, the present study developed regression relationships between environmental variables and fine root dynamics within a northern hardwood forest in New Hampshire, USA, which was experimentally manipulated with a snow removal treatment. Fine roots (< 1 mm diameter) were observed using minirhizotrons for 2 years in sugar maple and yellow birch stands and analyzed in relation to temperature, water and nutrient availability. Fine root dynamics at this site fluctuated seasonally, with growth and mortality peaking during warmer months. Monthly fine root production was strongly associated with mean monthly air temperature and neither soil moisture nor nutrient availability added additional predictive power to this relationship. This relationship exhibited a seasonal temperature hysteresis, which was altered by snow removal treatment. These results suggest that both exogenous and endogenous cues may be important in controlling fine root growth in this system. Proportional fine root mortality was directly associated with mean monthly soil temperature, and proportional fine root mortality during the over‐winter interval was strongly related to whether the soil froze. The strong relationship between fine root production and air temperature reported herein contrasts with findings from some hardwood forest sites and indicates that controls on fine root dynamics vary geographically. Future research must more clearly distinguish between endogenous and exogenous control over fine root dynamics in various ecosystems.
Interannual variability of plant phenology in tussock tundra: modelling interactions of plant productivity, plant phenology, snowmelt and soil thaw
Authors: Van Wijk M. T. , Williams M. , J. A.  , G. R.
Published: May 2003

We present a linked model of plant productivity, plant phenology, snowmelt and soil thaw in order to estimate interannual variability of arctic plant phenology and its effects on plant productivity. The model is tested using 8 years of soil temperature data, and three years of bud break data of Betula nana. Because the factors that trigger the end of the growing season of arctic vegetation are less well known than those of the start of the growing season, three hypotheses were formulated and tested for their effects on productivity and its sensitivity to climate change; the hypothesised factors determining the end of the growing season were frost, photoperiod and periodic constraints.

The performance of the soil thermal model was good; both the onset of soil thaw in spring and the initiation of freezing in autumn were predicted correctly in most cases. The phenology model predicted the bud break date of Betula nana closely for the three different years. The soil thaw model predicted similar growing season start dates under current climate as the models based on sum of temperatures, but it made significantly different predictions under climate change scenarios, probably because of the non‐linear interactions between snowmelt and soil thaw. The uncertainty about the driving factors for the end of the growing season, in turn, resulted in uncertainty in the interannual variability of the simulated annual gross primary productivity (GPP). The interannual variability ranged from − 25 to + 26% of the mean annual GPP for the frost hypothesis, from − 20 to + 20% for the photoperiod hypothesis and only from − 7 to + 7% for the periodic hypothesis. The different hypotheses also resulted in different sensitivity to climate change, with the frost hypothesis resulting in 30% higher annual GPP values than the periodic hypothesis when air temperatures were increased by 3 °C.
Soil‐surface carbon dioxide efflux and microbial biomass in relation to tree density 13 years after a stand replacing fire in a lodgepole pine ecosystem
Authors: LITTON CREIGHTON M. , RYAN MICHAEL G. , KNIGHT DENNIS H. , STAHL PETER D.
Published: May 2003

The effects of fire on soil‐surface carbon dioxide (CO2) efflux,FS, and microbial biomass carbon,Cmic, were studied in a wildland setting by examining 13‐year‐old postfire stands of lodgepole pine differing in tree density (< 500 to > 500 000 trees ha−1) in Yellowstone National Park (YNP). In addition, young stands were compared to mature lodgepole pine stands (∼110‐year‐old) in order to estimate ecosystem recovery 13 years after a stand replacing fire. Growing seasonFSincreased with tree density in young stands (1.0 µmol CO2 m−2 s−1in low‐density stands, 1.8 µmol CO2 m−2 s−1in moderate‐density stands and 2.1 µmol CO2 m−2 s−1in high‐density stands) and with stand age (2.7 µmol CO2 m−2 s−1in mature stands). Microbial biomass carbon in young stands did not differ with tree density and ranged from 0.2 to 0.5 mg C g−1dry soil over the growing season;Cmicwas significantly greater in mature stands (0.5–0.8 mg C g−1dry soil). Soil‐surface CO2efflux in young stands was correlated with biotic variables (above‐ground, below‐ground and microbial biomass), but not with abiotic variables (litter and mineral soil C and N content, bulk density and soil texture). Microbial biomass carbon was correlated with below‐ground plant biomass and not with soil carbon and nitrogen, indicating that plant activity controls not only root respiration, butCmicpools and overallFSrates as well. These findings support recent studies that have demonstrated the prevailing importance of plants in controlling rates ofFSand suggest that decomposition of older, recalcitrant soil C pools in this ecosystem is relatively unimportant 13 years after a stand replacing fire. Our results also indicate that realistic predictions and modeling of terrestrial C cycling must account for the variability in tree density and stand age that exists across the landscape as a result of natural disturbances.
MuSICA, a CO2, water and energy multilayer, multileaf pine forest model: evaluation from hourly to yearly time scales and sensitivity analysis
Authors: OGÉE J. , BRUNET Y. , LOUSTAU D. , BERBIGIER P. , DELZON S.
Published: May 2003

The current emphasis on global climate studies has led the scientific community to set up a number of sites for measuring long‐term biospheric fluxes, and to develop a wide range of biosphere–atmosphere exchange models. This paper presents a new model of this type, which has been developed for a pine forest canopy. In most coniferous species the canopy layer is well separated from the understorey and several cohorts of needles coexist. It was therefore found necessary to distinguish several vegetation layers and, in each layer, several leaf classes defined not only by their light regime and wetness status but also by their age. This model, named MuSICA, is a multilayer, multileaf process‐based model. Each submodel is first independently parameterized using data collected at a EUROFLUX site near Bordeaux (Southwestern France). Particular care is brought to identify the seasonal variations in the various physiological parameters. The full model is then evaluated using a two‐year long data set, split up into 12 day‐type classes defined by the season, the weather type and the soil water status. Beyond the good overall agreement obtained between measured and modelled values at various time scales, several points of further improvement are identified. They concern the seasonal variations in the stomatal response of needles and the soil/litter respiration, as well as their interaction with soil or litter moisture. A sensitivity analysis to some of the model features (in‐canopy turbulent transfer scheme, leaf age classes, water retention, distinction between shaded and sunlit leaves, number of layers) is finally performed in order to evaluate whether significant simplifications can be brought to such a model with little loss in its predictive quality. The distinction between several leaf classes is crucial if one is to compute biospheric fluxes accurately. It is also evidenced that accounting for in‐canopy turbulent transfer leads to better estimates of the sensible heat flux.
Using satisfaction to measure the quality of palliative care: a review of the literature
Authors: Aspinal Fiona , Addington‐Hall Julia , Hughes Rhidian , Higginson Irene J.
Published: May 2003

Background. The advent of clinical governance in British health policy has placed increased demands on health care providers and practitioners to ascertain the quality of their services. Traditional indicators of quality of health care, such as death or recovery rates, are not appropriate in palliative care. Thus, it is important to establish alternative approaches to measuring the quality of palliative care services and interventions.

Aims. Satisfaction levels have been used widely in palliative care to assess quality. A literature review was conducted which aimed to explore the strengths and weaknesses of using satisfaction as an indicator of the quality of palliative care services. It also aimed to provide a solid basis upon which further work could be built.

Methods. Five electronic databases were searched using key words and phrases and key authors. Hand searches were conducted of four journals that contributed significantly to the concept of satisfaction, and reference lists of reviewed papers were scrutinized. Relevant papers were reviewed, data were extracted and these data were thematically analysed.

Findings. There are a number of important unresolved issues in the literature with regard to using satisfaction as an indicator of the quality of palliative care services. First, few alternatives to satisfaction are available. Secondly, satisfaction is under‐theorized and no widely accepted definition exists. Thirdly, there are methodological inconsistencies across studies. It is important to take into account these findings when planning and implementing change following service evaluation using satisfaction as a measure.

Conclusions. Relying on findings of satisfaction surveys to determine clinical and policy amendments in palliative care may not result in improvements in overall quality of care. Using satisfaction as a method of assessing the quality of health care services is particularly problematic and requires further investigation in both practical and conceptual terms.
Clinical practice in a computer world: considering the issues
Authors: Hughes Rhidian A
Published: May 2003

Background. In an era when information technology developments are being harnessed by governments to improve patient care, it is important to consider the issues raised by the use of computers in health care practice and policy.

Aim. The aim of this paper is to provide an appraisal of considerations raised by the use of computers in health care.

Review focus. Drawing on a range of studies in the social and medical sciences, the paper reviews the considerations. The introduction to the paper maps out the policy context, which is followed by three substantive sections: first, computer hardware and software considerations; second, issues around confidentiality; and third, personal, social and cultural considerations.

Conclusion. This paper demonstrates that information technology developments must be allied with government or state direction and should be informed by evidence. Whilst the issues discussed are of primary relevance to the United Kingdom National Health Service, they have wider relevance to health care systems internationally.
Functional status in older women following hip fracture
Authors: Curry Linda Cox , Hogstel Mildred O. , Davis Gail C.
Published: May 2003

Background. Women aged 65 years and over are at high risk for a fractured hip because of osteoporosis. One of the devastating effects of a fracture is the loss of ability to live independently.

Aim. The major aim of this study was to describe the functional status, or ability to perform activities of daily living, of women aged 65 years and older who had experienced a fractured hip in the recent past and to explore possible differences in selected variables (e.g. age and length of rehabilitation) for those who were fully performing activities of daily living at least 6 months after fracture and those who were not.

Design. Following Institutional Review Board approval, data were collected from 23 Caucasian women ranging from 65 to 95 years of age (M = 82, sd = 6·83) who had experienced fractured hips related to a fall in the recent past (6 months to 4 years). All were living independently prior to their fractures. Three Registered Nurses, in a structured interview, collected the data using a Demographic Data Form, an Osteoporosis Risk Factor Checklist, the Katz Index of Independence in Activities of Daily Living, and the Lawton Instrumental Activities of Daily Living Scales.

Results. Nine of the participants reported prior fractures, suggesting that this could have been a risk factor for this group. Eighteen achieved the maximum independence score of six on the Katz Index of Independence in Activities of Daily Living; help with bathing was required by the other five. Of the Instrumental Activities of Daily Living, those requiring physical activity for home maintenance were the most problematic. Ability to perform Instrumental Activities of Daily Living was significantly related to ability to perform the activities required to live independently.

Conclusions. Results suggest that achieving a functional level that will support independence is possible for older women who were residing independently prior to a hip fracture.
Negotiated care: a model for nursing work in the renal setting
Authors: Polaschek Nick
Published: May 2003

Aim. This article outlines a model for the nursing role in the chronic health care context of renal replacement therapy.

Methods. Materials from several streams of literature are used to conceptualize the potential for nursing work in the renal setting as negotiated care. In order to present the role of the renal nurse in this way it is contextualized by viewing the renal setting as a specialized social context constituted by a dominant professional discourse and a contrasting client discourse.

Discussion. While performing specific therapeutic activities in accord with the dominant discourse, renal nurses can develop a relationship with the person living on dialysis, based on responsiveness to their subjective experience reflecting the renal client discourse. In contrast to the language of noncompliance prevalent in the renal setting, nurses can, through their relationship with renal clients, facilitate their attempts to negotiate the requirements of the therapeutic regime into their own personal life situation. Nurses can mediate between the dominant and client discourses for the person living on dialysis. Care describes the quality that nurses actively seek to create in their relationships with clients, through negotiation, in order to support them to live as fully as possible while using renal replacement therapy.

Conclusion. Within chronic health care contexts, shaped by the acute curative paradigm of biomedicine, the model of nursing work as negotiated care has the potential to humanize contemporary medical technologies by responding to clients' experiences of illness and therapy.
Barriers to paediatric nurses' research utilization
Authors: McCleary Lynn , Brown G. Ted
Published: May 2003

Background. A number of studies have investigated barriers to research utilization among nurses in various countries, and standardized scales have been validated to study this. Reported barriers have been categorized as individual, organizational and environmental, with organizational characteristics generally accounting for more variance. However, information about research utilization among paediatric nurses is lacking.

Aim. The objective of the research reported here was to investigate barriers to research utilization and relationships between those barriers and participation in research, self‐reported research utilization and education among paediatric nurses.

Design. A survey of all nurses in a paediatric teaching hospital; 176 nurses (33·3%) responded. Two standardized measures were used, the Barriers Scale and the Edmonton Research Orientation Scale.

Results. Lack of time to read research was the most frequently cited barrier to using research and administrators not allowing implementation was the least frequently cited. Characteristics of the communication and of the setting were more likely to be cited as barriers to research use than were characteristics of the nurse. Nurses who reported higher levels of actual research use were slightly less likely to see characteristics within themselves as barriers. Those who had taken a course about reading or using research were more likely to see the organization as a barrier. Barriers to research use were not associated with self‐reported understanding of research.

Conclusions. These results are congruent with previous findings that implementing research in practice is a complex process. They indicate that individual nurses' knowledge about research may not be as important as the process by which organizations implement research. However, the Barriers Scale measures general perceptions about barriers to research utilization and not nurses' specific experiences with barriers to implementing particular research.
The association between knee temperature and pain in elders with osteoarthritis of the knee: a pilot study
Authors: Tsai Pao‐Feng , Richards Kathy , Tatom Iris
Published: May 2003

Background. Osteoarthritis is a highly prevalent, disabling condition that causes significant pain and suffering among older adults. Cognitively impaired elders are as susceptible to osteoarthritis as their peers. However, since they have diminished ability to communicate their pain, an alternative method to detect osteoarthritis pain in cognitively impaired elders is urgently needed. Because the late stages of osteoarthritis involve joint inflammation with a mild increase in local temperature, skin surface temperature might reasonably be expected to serve as a proxy measure of osteoarthritis pain. If knee surface temperature could be shown to predict pain in cognitively intact elders, it could be used as a proxy measure of pain for cognitively impaired elders.

Aim. To test this, the study reported here assessed the relationship between knee surface temperature and pain in cognitively intact elders with osteoarthritis of the knee.

Methods. We recruited 12 cognitively intact elders with documented osteoarthritis of the knee who lived in retirement apartments. Elders' pain and knee temperature were measured three times on three separate occasions. Osteoarthritis pain of the knee was measured using the Knee Pain Scale and the Western Ontario and McMaster Osteoarthritis Index pain subscale. A YSI Model 4000 Dual Channel Display Telethermometer was used to measure knee temperature.

Results. We found no significant associations between knee temperature and any of the pain measures used, with one exception. However, body mass index, amount of pain medication used and activity level observed during the interview were significantly related to elders' pain.

Conclusion. Knee temperature does not appear to predict knee pain in elders with osteoarthritis of the knee. Body mass index, use of pain medication and activity level are better predictors of this.
Integration into higher education: key implementers' views on why nurse education moved into higher education
Authors: Burke Linda M.
Published: May 2003

Aim. The aim of this paper is to discuss the opinions of the key individuals involved in implementing the integration of nurse education into higher education in the United Kingdom (UK) about why nurse education moved into higher education and why this happened when it did.

Background. In 1995 the last of the old‐style schools of nursing in the UK was fully integrated into higher education and were detached financially, legally and organizationally from District Health Authorities. However, only 6 years before, when Working Paper 10 was produced, there were only a few nursing degree courses located within higher education. What made this move into higher education particularly noteworthy was that there was never a clear statement of intent from the government that this integration of health care education was intended. Despite the fact that this is one of the most significant changes ever to take place in nurse education, there has been relatively little empirical research about why the development occurred.

Methods. A qualitative approach was selected for this study and the methods used were policy analysis and interviews. A purposeful sample of 70 implementers involved in the integration process was selected and asked for their views on this issue.

Findings. Participants believed that integration had occurred because of a combination of complex factors, but there was a division between those who thought that it was centrally planned and others who felt that it was an accidental outcome of the particular events of the time.

Conclusions. It is not clear whether policy was influencing action or action influencing policy. Understanding of why this change occurred is needed if health care professionals wish to have greater control over future changes in education.
Irish nursing students' changing self‐esteem and fear of negative evaluation during their preregistration programme
Authors: Begley Cecily M. , White Patricia
Published: May 2003

Background. Studies on Irish nursing and midwifery professions have demonstrated that stress and bullying are frequent problems that may lead to depression and low self‐esteem. Self‐esteem is linked to social anxiety and is therefore related to fear of negative evaluation. It is important to study nursing students' feelings about self‐esteem and negative evaluation, and to assess whether or not both these constructs change as students progress through their preregistration education programme.

Aim. This study explored nursing students' perceived levels of self‐esteem and their fear of negative evaluation prior to, and nearing the completion of, their 3‐year preregistration programme.

Methods. A descriptive, quantitative, comparative survey design was used. All students in the first intake of 1995 in two general nursing schools in Southern Ireland agreed to take part (n = 72). A questionnaire developed from the Rosenberg Self‐esteem Scale and the Watson and Friend Fear of Negative Evaluation Scale was used to collect data at the start of their programme and again 2 months before completion.

Results. In general, students' reported self‐esteem rose as they neared the end of their education programme and their fear of negative evaluation decreased; however, their overall self‐esteem levels at their highest were only average.

Conclusions. Many of the studies examining self‐esteem have produced contradictory results. An examination of the organizational factors that contribute to self‐esteem may increase our understanding of the phenomenon. Self‐esteem is a complex, multifaceted phenomenon. While there is no single factor that can increase or decrease a person's self‐esteem, this study has explored the potential impact of the fear of negative evaluation on self‐esteem. Nursing students' self‐esteem might be increased by expansion of intrinsic job characteristics, improving their job satisfaction and providing frequent positive feedback.
Measuring nursing workload in intensive care: an observational study using closed circuit video cameras
Authors: Adomat Reneé , Hicks Carolyn
Published: May 2003

Background. There is an increasing demand for intensive care provision in the United Kingdom (UK), partly because of a national shortage of intensive care beds. The problem is compounded by the current method for calculating the nurse: patient ratio using a Nurse Workload Patient Category scoring system or similar adaptations used in many intensive care units. This ratio is calculated by using patient category or dependency scales, which operate on the assumption that the more critically ill the patient, the more nurse time is needed to care for the patient. However, many mechanically ventilated critically ill patients (allocated a high category of care) may need less nursing care than patients who are self‐ventilating and allocated a lower level of dependence.

Purpose. In this study, a video recorder was used to document nurse activity for 48 continuous shifts in two intensive care units to determine the accuracy of the Nursing Workload Patient Category scoring system in measuring nurse workload.

Methods. The video data were correlated later with the Patient Category allocated to the patient by the nurse at the time.

Results. The results of this observational study demonstrated that, despite complex care needs, a high percentage of nursing activities observed in each unit consisted of low skill activity. Furthermore, nurses spent less time with patients categorized as in need of intensive care than those in need of high dependency care in both units.

Conclusion. The findings suggest that existing nurse:patient ratio classifications may be inappropriate, since nurses spent less time with critically ill patients. Radical reconsideration of nursing levels and skill mix might make it possible to increase intensive care provision because fewer nurses would be needed to staff each bed. The findings support alternative and more flexible systems for assessing workload and the use of different nurse:patient ratios.
Primary health care provision for adults with a learning disability
Authors: Elaine Powrie
Published: May 2003

Background. During the last decade, primary care has been designated as the main provider of health care to people with learning disabilities. Practice nurses based in primary care teams are increasingly the first points of contact with health services. They make an important contribution to promoting good health, with health screening and illness prevention work being a significant part of their role. However, little is known about their views or involvement regarding the provision of primary care for people with learning disabilities. There is therefore a need to explore the nursing perspective, from within primary care, on the current provision of care for people with a learning disability.

Research aim. To inform the learning disability service of the role of primary care in current service provision for people with learning disabilities.

Research method. A survey of all practice nurses currently employed by Grampian Health Board in Aberdeen was conducted in June 2001. An initial pilot study was conducted in primary care and learning disability services. Data collection took place during June and July 2001. All practice nurses working in the geographical region of Grampian were invited to participate.

Results. Communication barriers exist, preventing access to health screening and treatment for some people with learning disabilities. Independent living skills, for example dietary management and budgeting, require additional community support. These conditions pose complex problems for practice nurses and other members of the primary care team.

Conclusion. This study indicates a need for closer support and partnership with the learning disability service. The factors necessary for providing health care to people with learning disabilities extend beyond the domain of primary care teams. The findings of this survey have important implications for education and support to enable carers and professionals to provide a high standard of care.
Stress analysis in a post‐restored tooth utilizing the finite element method
Authors: Toparli M.
Published: May 2003

summary  This study utilized the finite element method (FEM) to predict distribution of stresses in dentin of an endodontically treated tooth, restored with cast post and cores. For this investigation an axisymmetric model of a maxillary second pre‐molar that included an alveolar bone was analysed. The three tooth models evaluated were Ti–Ti alloy, NiCr–AuPd alloy and Ti–NiCr alloy as post‐material and crown material with porcelain. A load of 200 N at an angle of 45° to the longitudinal axis was applied on the occlusal margin of each model. The tooth was assumed isotropic, homogenous and elastic. The author prepared a calculation program using fortran 77. Investigation of the stress distributions was made in five regions; namely bottom of post, top of post, cole, metal–cement interface and metal–porcelain interface. The distributions of radial and axial stresses were plotted with length of radial.
Evaluation of cetylpyridinium chloride for infection control in storage solution
Authors: Ziskind D. , Gleitman J. , Rotstein I. , Friedman M.
Published: May 2003

summary  Storage solution is used in in vitro experimental studies to prevent dehydration of teeth collected immediately after extraction and to prevent bacterial and fungal growth in the storage media. The chemical nature of the storing agent may affect the tooth structure and material properties at the tested interface. The aim of this study was to evaluate the use of 0·1% cetylpyridinium chloride (CPC) as a new storage solution and to assess the possible effect of 0·1% thymol on microleakage and bond strength. Forty extracted human teeth were collected from 10 different dental clinics. Immediately after extraction, the teeth were randomly divided and immersed in four different storage solutions. Two test solutions of 0·1% CPC (group C) and 0·1% thymol (group T) were compared with phosphate‐buffered saline (Group S – positive control) and to 3% H2O2 (group H – negative control). Bond strength test and dye penetration evaluation were then carried out. The findings suggest that the use of 0·1% CPC as storage solution does not affect bond strength to enamel. However, it may increase dye penetration at the cervical margin. The effect of 0·1% thymol on shear bond strength and dye penetration is similar to the effect of phosphate‐buffered saline.
Stress distribution of abutments and base displacement with precision attachment‐ and telescopic crown‐retained removable partial dentures
Authors: Saito M. , Miura Y. , Notani K. , Kawasaki T.
Published: May 2003

summary  Five types of removable partial dentures (two attachment dentures, two telescopic dentures and one clasp denture) were designed. The two attachment dentures were retained by the rigid‐precision attachments with or without a stabilizing arm, and the two telescope dentures were retained with cone telescope crowns with or without cross‐arch stabilization. The stresses acting on abutment teeth and denture bases and the movements of denture bases were investigated, and the influences of denture design were clarified. The stress acting on a terminal abutment tooth retained by a rigid‐precision attachment or cone telescopic crown was larger than that acting on a terminal abutment tooth retained by a clasp. The attachment dentures tended to concentrate more stress at the terminal abutment tooth than did the telescopic dentures. The stress of denture base of an attachment denture and a telescopic denture was less than that of a clasp denture. There was no difference between the stresses of attachment and telescopic dentures. The displacement of the denture base tended to be less when the denture was designed with a rigid connection for the retainer and with cross‐arch stabilization.
An infection control protocol: effectiveness of immersion solutions to reduce the microbial growth on dental prostheses
Authors: Pavarina A. C. , Pizzolitto A. C. , Machado A. L. , Vergani C. E. , Giampaolo E. T.
Published: May 2003

summary  This investigation evaluated the effectiveness of an infection control protocol for cleansing and disinfecting removable dental prostheses. Sixty‐four dentures were rubbed with sterile cotton swab immediately after they had been taken from patients' mouths. Samples were individually placed in the culture medium and immediately incubated at 37 ± 2 °C. The dentures were scrubbed for 1 min with 4% chlorhexidine, rinsed for 1 min in sterile water and placed for 10 min in one of the following immersion solutions: 4% chlorhexidine gluconate, 1% sodium hypochlorite, Biocide (iodophors) and Amosan (alkaline peroxide). After the disinfection procedures, the dentures were immersed in sterile water for 3 min, reswabbed and the samples were incubated. All samples obtained in the initial culture were contaminated with micro‐organisms. All the lower dentures immersed in Biocide showed positive growth, and the upper dentures were positive for growth in six of eight dentures. The 4% chlorhexidine gluconate, 1% sodium hypochlorite and Amosan solutions have been proved effective to reduce the growth of the micro‐organisms in the 10 min immersion period. The protocol evaluated in this study seems to be a viable method to prevent cross‐contamination between dental personnel and patients.
A preliminary report on a computer‐assisted dental cast analysis system used for the prosthodontic treatment
Authors: Kojima T. , Sohmura T. , Nagao M. , Wakabayashi K. , Nakamura T. , Takahashi J.
Published: May 2003

summary 

To accomplish computerized 3D morphological analyses of maxillary and mandibular casts with malocclusions on the same co‐ordinate system, a new reference co‐ordinate located on soft tissue has been proposed consisting of the top of maxillary bilateral tubercles and incisive papilla on the maxillary cast. To test the validity of this co‐ordinate system, the angles of the occlusal plane in this system were examined on 10 subjects with normal occlusion. In addition, to analyse maxillary and mandibular casts on the same co‐ordinate system, a bite block was made under the intercuspal position. The maxillary cast was measured by 3D measuring system, then, the bite block was placed on maxillary casts, and measured similarly. To examine the position reproducibility of this method, 3D co‐ordinates of the apex of the buccal cusp of the mandibular pre‐molar in five bite blocks were determined. The angles formed of the occlusal plane were 1·3 ± 1·3° and 0·2 ± 1·1° on the sagittal and frontal base plane, respectively. This co‐ordinate system had enough stability to replace the occlusal plane. By the measurement of bite blocks, the co‐ordinates of the mandibular cusp tips were determined within the deviation of 0·2 mm.
The effect of simulated intrapulpal pressure on bond strength to enamel and dentine
Authors: Sengun A. , Ozturk B. , Ozer F.
Published: May 2003

summary  The purpose of this study was to evaluate the effect of simulated intrapulpal pressure on the shear bond strength (SBS) of a self‐etching bonding system (Clearfil Liner Bond II) to both enamel and dentine surfaces. Forty‐two caries‐free human molar teeth were randomly assigned to two equal groups (n=21). One group of 21 teeth was connected to a special pulpal pressure machine, which is developed to simulate in vivo conditions. The buccal and lingual surfaces of the teeth were prepared with a diamond wheel to create flat dentine and enamel surfaces. A self‐etching bonding system was then applied under pulpal pressure and 2·5 mm diameter composite cylinders were bonded to the prepared surfaces. The samples were then stored in distilled water at room temperature for 24 h under pulpal pressure before SBS was tested. The second restored group was used as a control and the teeth were not connected to the pulpal pressure apparatus during material application and test procedures. They were stored for 24 h in distilled water at room temperature before the SBS test. Fracture analysis of the enamel and dentinal surfaces was performed using a stereomicroscope. Shear bond strength values to dentine was significantly reduced with pulpal pressure (P < 0·001). However, in the enamel, SBS was increased (P < 0·001). In the control group, the SBS values to dentine and enamel did not show any significant difference (P > 0·05). Based on these results, it can be concluded that further analysis of enamel histology and bonding mechanisms are needed.
Influence of tea on intrinsic colour of previously bleached enamel
Authors: Attin T. , Manolakis A. , Buchalla W. , Hannig C.
Published: May 2003

summary  Aim of the study was to evaluate the influence of tea applied at various time intervals after bleaching of enamel on intrinsic tooth colour. Ninety bovine specimens were distributed among six groups (A–F, n=15). The samples of group A–D were bleached with the 10% carbamide peroxide (CP) gel VivaStyle for 8 h, followed by storing in artificial saliva for the remaining period of the day. The specimens were removed from the saliva at different intervals (A: 0 min, B: 60 min, C: 240 min) and immersed in freshly prepared black tea for 10 min. Group D (bleaching, no tea), E (no bleaching, but tea) and F (no bleaching, no tea) served as controls. These procedures were repeated for 8 days. Colour was measured at baseline, after each day, and after final cleaning using the CIELab‐system. Then Δb (initial b‐value – final reading), ΔL, and composite colour (ΔE) were statistically analysed. External bleaching (A–D) led to a distinct whitening effect with lower Δb‐ (=reduction in yellow) and higher ΔL‐values (=increase in brightness) compared with controls. The Δb‐ and ΔL‐values of the samples A–C were not significantly different from the samples which were bleached only. No significant difference was observed comparing specimens of group A–C. It is concluded that application of tea directly after bleaching with 10% CP does not significantly effect the outcome of a bleaching treatment irrespective of the time interval elapsed between the bleaching procedure and the contact of the tooth surface with tea.
The dynamic range of TMJ sounds
Authors: Widmalm S. E. , Djurdjanovic D. , McKay D. C.
Published: May 2003

summary  It is of clinical interest to record the amplitudes of temporomandibular joint (TMJ) sounds. The aim was to test the hypothesis that sealing the meatus, when placing a microphone in the ear canal affects such recording by increasing the sound pressure level (SPL). Bilateral recordings of 249 TMJ clickings were made from three subjects, using sampling rates of 48 or 96 kHz and 24 bits A/D conversion, with and without the ear canals sealed by Silicone putty. The peak‐to‐peak equivalent sound pressure level (peSPL) was higher (P < 0·001) when the ear canal was sealed (range of mean differences was 8·3–24·9 dB peSPL). This means that the signal to noise ratio can be improved by sealing the meatus because the electronic noise level is not increased. Most important is that the dynamic range of the clicking sounds was 62 dB that is larger than the effective dynamic range of a 16 bits sound card. Future studies are needed to establish normative peSPL values. However, cards with at least 24 bits A/D conversion will be required, especially in patients with suspected disc displacement with reduction, where the difference in loudness between opening and closing clicking often is large.
Analysis of depth of the microporosity in a nickel–chromium system alloy – effects of electrolytic, chemical and sandblasting etching
Authors: Neto H. G. , Cândido M. S. M. , Júnior A. L. R. , Garcia P. P. N. S.
Published: May 2003

summary  The present study was designed to analyse the average depth of the microporosity of a nickel–chromium (Ni–Cr) system alloy (Verabond II). The metal surface was subject to one of the following surface treatment: (i) Electrolytic etching in nitric acid 0·5 N at a current density of 250 mA cm−2; (ii) chemical etching with CG‐Etch etchant; and (iii) Sandblasting with alumina particles 50 μm. Half of the samples were polished before the surface treatments. The depth of porosity was measured through photomicrographs (500×) with a profilometer, and the data were statistically analysed using an analysis of variance (anova) followed by Tukey's test. The conclusions were (i) Differents surface treatment of the Ni–Cr system alloy lead to different depths of microporosity; (ii) The greatest depth of porosity was observed in non‐polished alloy; (iii) The greatest and identical depth of microporosity was observed following electrolytic etching and chemical etching; (iv) The least and identical depth of microporosity was observed with chemical etching and sandblasting with alumina particles 50 μm, and (v) Chemical etching showed an intermediary depth.
Treatment with removable partial dentures: a longitudinal study. Part I
Authors: Vanzeveren C. , D'Hoore W. , Bercy P. , Leloup G.
Published: May 2003

summary  The aim of this study was to evaluate the effectiveness of an oral rehabilitation by removable partial denture (RPD). Between 1983 and 1994, 629 patients were provided with an RPD at the Dental School of the Université catholique de Louvain. All the RPDs were constructed with a cobalt–chromium framework. All the treatments were provided by dental students under the supervision of clinical instructors. At recall time (1998–2000), 269 patients could not be reached neither by telephone nor by mail and 27 had died. Consequently, 333 patients were called for clinical examination and 254 of these (76·3%) actually attended. For a total of 292 RPDs fitted for these 254 patients, 218 (74·7%) were still being worn at the time of the check‐up. Seventy‐four dentures were considered to be ‘failures’, either because they were replaced by another RPD or by a complete denture, or because they had actually never been worn. The statistical analysis (Mantel–Haenszel and Kaplan–Meier) shows that the number of failures is significantly higher at the lower jaw compared with the upper jaw. Most of the failures are attributable to RPDs with free‐end saddles and, in particular, to class I mandibular dentures. The patients are wearing their denture(s) mostly continuously (63·6%) and award a high degree of satisfaction to their denture. In general, the results recorded may be considered as very satisfactory, all the more so as we have no regular recall procedures established at our school and as check‐up asked for spontaneously by the patients in the course of the period of observation are most of the time occasional or non‐existent.