bluuebunny/crossref_metadata_2025 huggingface dataset:
How great tits maintain synchronization of their hatch date with food supply in response to long‐term variability in temperature
Authors: Cresswell Will , Mccleery Robin
Published: December 2004

Breeding birds increase their fitness by synchronizing their production of chicks with a peak of food abundance. Synchronization is primarily achieved by varying first egg date, but yearly temperature variations may delay or accelerate the food peak after the first egg has been laid. We tested the extent to which great tits (Parus major L.) can strategically change their synchronization of hatch date with the food peak after the first egg has been laid by changing clutch size, laying interval and the amount of incubation. We also tested whether these possible synchronization change mechanisms resulted in changes in breeding success, because if the food peak is late relative to first egg date, we would predict more of the population to have larger clutches and/or a hatch date synchronous with the food peak date.

Great tits modified synchronization strategically by varying clutch size and the onset of incubation after clutch completion. When first egg date was early but then followed by cold weather so that the food peak was late, clutch sizes were larger, and when first egg date was late and temperatures were low, mean incubation periods were shorter if the food peak was early.

Over the 39‐year period of the study, the period between the first egg date and food peak increased significantly by 1·7 days more than the period between the food peak and hatch date. Great tits have maintained synchronization by significantly increasing their incubation period.

Overall, the proportion of nests that had synchronous hatch dates depended on the yearly temperature pattern: the decline in variance between date of clutch completion and hatch was significantly greater in years where prelaying temperatures were higher (i.e. early first egg dates) and has therefore increased in recent years because of climate change. In warm early seasons (and more often in recent years) more of the great tits that laid relatively late had sufficient time to complete their clutches before having to start incubation in order to hatch in time for the food peak.

The increased proportion of synchronized nests in recent years probably resulted in increased chick output: a greater proportion of recent nests successfully fledged all of the chicks that hatched and the number of young fledged per successful nest also increased in recent years. These changes may have arisen because the proportion of nests with disadvantageous asynchronous hatching and/or smaller clutches has decreased. As the proportion of great tits that start nesting too late to synchronize has declined so selection for early laying has also declined in recent years.
The effects of spawning age distribution on salmon persistence in fluctuating environments
Authors: Hill M. Forrest , Botsford Louis W. , Hastings Alan
Published: December 2004

Understanding the role endogenous vs. exogenous forces play in determining the dynamics and abundance of natural populations has important implications for their conservation.

Changes in environmental conditions often have different effects on closely related species. For instance, recent studies show that a physical shift in ocean conditions in the mid‐1970s in the California current have reduced coho salmon (Oncorhynchus kisutsch) populations, but not chinook salmon (O. tshawytscha).

An important question is whether this pattern is due to differences in the ability of coho and chinook salmon to respond to changing ocean conditions or to differences in their life‐history traits.

We analysed a series of population models to test whether observed abundance patterns of coho and chinook salmon could be explained by one of the major differences in their life history, the spawning age distribution; in the California current, female coho salmon are considered to be obligate semelparous, spawning at age 3, while chinook salmon are considered indeterminate semelparous, with populations spawning over a range of ages.

Results from a deterministic model indicate that the sensitivity of the population growth rate to changes in ocean survival depends little on the spawning age structure, especially when the growth rate is small (λ ≈ 1).

Analysis of linear and non‐linear stochastic models indicate that the probability of persistence increases with the width of the spawning age distribution, as the fraction of adults spawning at age 3 decreases from 100% to 95%. Further increases in the spawning age distribution have negligible affects on persistence.

Because coho salmon are not absolutely obligate semelparous (e.g. as many as 25% of males can spawn precociously at age 2 and their effect on annual reproduction is unknown), this range of sensitivity does not provide a firm basis for assuming that the observed abundance patterns of coho and chinook is due to differences in their spawning age distribution.

While other life‐history differences could play a role, we recommend that ongoing field studies focus on the different effects changing ocean conditions have on the survival of individual salmon species.
Sexual dimorphism in susceptibility to parasites and cell‐mediated immunity in great tit nestlings
Authors: Tschirren Barbara , Fitze Patrick S. , Richner Heinz
Published: December 2004

Parasites can affect host fitness, provoke host responses, and thereby mediate host life history evolution. As life history strategies are often sex‐specific, immunological or behavioural responses of the host aiming to reduce the impact of parasites may be sexually dimorphic, e.g. as a consequence of sex differences in the resource allocation trade‐off between parasite defence, morphological traits and body functions. Parasites may therefore affect males and females differently leading to sex specific patterns of parasite susceptibility.

In an experimental field study, we manipulated the ectoparasite load of great tit nests (Parus major) and investigated its effects on male and female nestlings. As susceptibility to parasites may be linked to the ability of the nestlings to fight off parasites immunologically, we further investigated sex differences in cell‐mediated immunity using a phytohaemagglutinin (PHA) assay.

Body mass, metatarsus length and overall body size, but not feather length, showed a sexual dimorphism at the end of the nestling period. A significant interaction between the effects of sex and parasite treatment on the sexually dimorphic traits indicates that the parasite effect is sex‐specific. While no differences in morphological traits were found in females raised in infested and uninfested nests, parasitized males were significantly smaller and lighter than males raised in uninfested nests. Further, we found a pronounced sexual dimorphism in the response to the PHA assay with males showing a reduced cellular immunity. The parasite treatment had a non‐significant effect on the PHA response and the PHA response of males and females were not influenced differently by parasites.

Our study shows that sexual dimorphism in susceptibility to parasites and immunocompetence develops early in life, and suggests sex‐specific strategies in the allocation of limited resources. Possible mechanisms of sex differences in susceptibility to parasites and immunocompetence during postnatal growth and the consequences for optimal sex allocation strategies of the parents are discussed.
Detection of imperfect population synchrony in an uncertain world
Authors: Cazelles Bernard , Stone Lewi
Published: December 2004

We propose the method of ‘phase analysis’ for studying the spatio‐temporal fluctuations of animal populations, and use this method for helping identify remarkable synchronized population fluctuations that may sometimes be found over very large spatial domains.

The method requires decomposing the observed time series of population fluctuations into two components – one that quantifies the changing phase of the signal, and the other that quantifies the changing amplitude.

Two populations are considered to be ‘phase synchronized’ if there is locking or synchrony between their phase components, while their associated amplitudes may nevertheless remain largely uncorrelated.

Since environmental noise often masks population synchrony, a null hypothesis approach is used to detect whether the phase variables are locked more than would be expected by chance alone.

The technique is thus particularly appropriate for ecological analyses where it is often important to study evidence of weak interactions in irregular non‐stationary and noisy time series. Because climatic patterns (and predicted climate changes) almost certainly influence population dynamics, the approach appears particularly relevant for analysing the potential links between climatic fluctuations and population abundance.
Linking landscape patterns of resource distribution with models of aggregation in ovipositing stream insects
Authors: Lancaster Jill , Downes Barbara J. , Reich Paul
Published: December 2004

Many species rely on resources that are discrete patches distributed across the landscape. Models of the coexistence of such taxa often require intraspecific aggregation of individuals on some patches, brought about by choices made during dispersal and patch location. Few studies have employed spatially explicit measures of dispersion to detect whether and how any aggregation of individuals is influenced by the dispersion of resource patches in natural landscapes.

For two species of caddisfly (Hydrobiosidae) in two stream stretches, we mapped the spatial distribution of potential and exploited patches (emergent rocks as oviposition sites) and enumerated egg masses on each rock. Point pattern analysis, based on Ripley's K‐function, was used to describe the spatial pattern of potential and exploited oviposition sites, and to test hypotheses about how site selection behaviour of females influences dispersion.

Emergent rocks were clumped and equally abundant in both stretches. As documented previously, egg masses of Ulmerochorema and Apsilochorema were aggregated within oviposition sites. Both species showed velocity‐specific preferences for oviposition sites: oviposition of Ulmerochorema occurred most often on rocks in fast flowing water (>0·30 m s−1); oviposition of Apsilochorema on rocks in slow water (<0·30 m s−1).

Our perception of how caddisflies deposit eggs into the stream landscape varied with the neutral landscape model. The most informative neutral landscape compared the spatial pattern of oviposition sites with the underlying pattern of emergent rocks, while constraining the random selection of rocks to reflect species’ velocity preferences. Oviposition sites of Ulmerochorema were clumped, over and above the background pattern of emergent rocks. Oviposition sites of Apsilochorema were over‐dispersed.

Hydrobiosid caddisflies appear to make decisions about egg‐laying at different scales. We propose a mechanistic explanation, based on what we know about the oviposition behaviour of these species, to explain how the observed patterns might arise. Our results emphasize the importance of quantifying resource patch use in natural (rather than artificial) landscapes.
Experimental manipulation of habitat structure: a retrogression of the small mammal succession
Authors: Fox Barry J. , Taylor Jennifer E. , Thompson Peter T.
Published: December 2004

The habitat accommodation model for animal succession proposed that animal species enter a succession when changes in the vegetation succession reach a threshold of habitat suitable to that species. As the vegetation succession moves on, the habitat becomes less suited to that species and it is competitively excluded by species better suited to the habitat.

The main species in the mammalian succession following fire for wet heath in eastern Australia are rodents, with Pseudomys gracilicaudatus (eastern chestnut mouse) being followed by Rattus lutreolus (swamp rat) which becomes dominant with increasing time since fire. The abundance of both species has been shown to correlate with vegetation density, but in markedly different ways, and asymmetric interspecific competition has been demonstrated using controlled, replicated removal experiments in the field.

We used this system to examine if vegetation density is causal, manipulating the habitat by clipping to remove 60–70% of the vegetative cover from the 10 m × 10 m area surrounding each of six trapping stations on each grid. There were four experimental plots clipped, each with two abutting grids, one clipped and one unclipped, and a further four control plots each with two abutting grids that remained undisturbed.

We monitored the effects on each species with three censuses in January 1993 (summer) before clipping in early February, and on five further censuses, three in February (late summer) to assess immediate, short‐term effects, one in August (winter) and one in December 1993 (early summer).

The abundance of Rattus lutreolus was significantly reduced by clipping the vegetation, while the abundance of Pseudomys gracilicaudatus remained relatively unchanged by the clipping.

Two species that are abundant on early succession stages in dry heath succession, but occurred at very low abundance on these wet heath habitats before clipping, P. novaehollandiae (New Holland mouse) and Mus domesticus (house mouse), showed marked increases in abundance on clipped and control plots soon after clipping.

An abundance index based on the standardized difference between clipped and control plots, was used to assess responses to habitat manipulation. Rattus lutreolus demonstrated significant negative index values, Pseudomys gracilicaudatus had index values close to zero until the winter census, P. novaehollandiae and Mus domesticus showed positive abundance indices soon after clipping. The order of significant responses to the habitat manipulation was revealed as: Mus domesticus→Pseudomys novaehollandiae→ P. gracilicaudatus→ Rattus lutreolus.

The impact of a habitat manipulation experiment on these four species of rodents produced a retrogression of the small‐mammal succession. This demonstrated a causal role for vegetation density, which provided insight into the mechanisms that operate during the succession following fire, and supported the habitat accommodation model for animal succession.
Trophic facilitation by introduced top predators: grey wolf subsidies to scavengers in Yellowstone National Park
Authors: Wilmers Christopher C. , Crabtree Robert L. , Smith Douglas W. , Murphy Kerry M. , Getz Wayne M.
Published: December 2004

The reintroduction of grey wolves Canis lupus (L.) to Yellowstone National Park provides a natural experiment in which to study the effects of a keystone predator on ecosystem function.

Grey wolves often provision scavengers with carrion by partially consuming their prey.

In order to examine how grey wolf foraging behaviour influences the availability of carrion to scavengers, we observed consumption of 57 wolf‐killed elk Cervus elaphus (L.) and determined the percentage of edible biomass eaten by wolves from each carcass.

We found that the percentage of a carcass consumed by wolves increases as snow depth decreases and the ratio of wolf pack size to prey size and distance to the road increases. In addition, wolf packs of intermediate size provide the most carrion to scavengers.

Applying linear regression models to the years prior to reintroduction, we calculate carrion biomass availability had wolves been present, and contrast this to a previously published index of carrion availability. Our results demonstrate that wolves increase the time period over which carrion is available, and change the variability in scavenge from a late winter pulse dependent primarily on abiotic environmental conditions to one that is relatively constant across the winter and primarily dependent on wolf demographics. Wolves also decrease the year‐to‐year and month‐to‐month variation in carrion availability.

By transferring the availability of carrion from the highly productive late winter, to the less productive early winter and from highly productive years to less productive ones, wolves provide a temporal subsidy to scavengers.
Declining survival rates in a reintroduced population of the Mauritius kestrel: evidence for non‐linear density dependence and environmental stochasticity
Authors: Nicoll M. A. C. , Jones Carl. G. , Norris Ken
Published: December 2004

We studied a reintroduced population of the formerly critically endangered Mauritius kestrel Falco punctatus Temmink from its inception in 1987 until 2002, by which time the population had attained carrying capacity for the study area. Post‐1994 the population received minimal management other than the provision of nestboxes.

We analysed data collected on survival (1987–2002) using program MARK to explore the influence of density‐dependent and independent processes on survival over the course of the population's development.

We found evidence for non‐linear, threshold density dependence in juvenile survival rates. Juvenile survival was also strongly influenced by climate, with the temporal distribution of rainfall during the cyclone season being the most influential climatic variable. Adult survival remained constant throughout.

Our most parsimonious capture–mark–recapture statistical model, which was constrained by density and climate, explained 75·4% of the temporal variation exhibited in juvenile survival rates over the course of the population's development.

This study is an example of how data collected as part of a threatened species recovery programme can be used to explore the role and functional form of natural population regulatory processes. With the improvements in conservation management techniques and the resulting success stories, formerly threatened species offer unique opportunities to further our understanding of the fundamental principles of population ecology.
Strong context‐dependent virulence in a host–parasite system: reconciling genetic evidence with theory
Authors: Brown Mark J. F. , Schmid‐Hempel Regula , Schmid‐Hempel Paul
Published: December 2004

Parasites can have dramatic effects on the ecology of their hosts. Such strong host–parasite interactions are the result of either parasites with generally high virulence, or generally benign parasites that nevertheless express context‐dependent virulence. Theoretically, one indication that an apparently benign parasite nevertheless has a large impact on its host should be the existence of strong genotypic interactions between host and parasite.

Crithidia bombi (Trypanosomatidae) is a highly prevalent but generally benign gut parasite of the bumble‐bee Bombus terrestris. The demonstration of strong genotypic interactions between C. bombi and B. terrestris, however, suggests that context‐dependent virulence may have a large impact on the host population. We thus investigated the effects of C. bombi across the entire life cycle of its host, including the stressful times of hibernation and colony‐founding. Owing to the high prevalence and rates of transmission of the parasite in field populations, we used a large‐scale laboratory experiment.

Under stressful hibernation, infected queens lost more mass. Infection also significantly reduced colony‐founding success, colony size, male production and overall fitness, by up to 40%. These findings show that strong genotypic host–parasite interactions may indeed be a reliable indicator that apparently benign and highly prevalent parasites are nevertheless exerting a dramatic impact on their host populations.
Estimating natal dispersal movement rates of female European ducks with multistate modelling
Authors: Blums Peter , Nichols James D. , Hines James E. , Lindberg Mark S. , Mednis Aivars
Published: December 2004

We used up to 34 years of capture–recapture data from about 22 100 new releases of day‐old female ducklings and multistate modelling to test predictions about the influence of environmental, habitat and management factors on natal dispersal probability of three species of ducks within the Engure Marsh, Latvia.

The mean natal dispersal distances were very similar (c. 0·6–0·7 km) for all three species and were on average 2·7 times greater than breeding dispersal distances recorded within the same study system.

We were unable to confirm the kinship hypothesis and found no evidence that young first‐nesting females nested closer to their relatives (either mother or sister) than to the natal nest.

Young female northern shovelers, like adults, moved from small islands to the large island when water level was high and vice versa when water level was low before the construction of elevated small islands. Movement probabilities between the two strata were much higher for young shovelers than adults, suggesting that young birds had not yet developed strong fidelity to the natal site. Movements of young female tufted ducks, unlike those of shovelers, were not dependent on water level fluctuations and reflected substantial flexibility in choice of first nesting sites.

Data for young birds supported our earlier conclusion that common pochard nesting habitats in black‐headed gull colonies were saturated during the entire study period. Young females, like the two adult age groups, moved into and out of colonies with similar probability. Fidelity probability of female pochards to each stratum increased with age, being the lowest (0·62) for young (DK) females, intermediate (0·78) for yearlings (SY) and the highest (0·84) for adult (ASY) females.

Young female tufted ducks, like adults, showed higher probabilities of moving from islands to emergent marshes when water levels were higher both before and after habitat management. The relationship between the spring water levels and movement was much weaker for young females than for adults.

Young female diving ducks exhibited much stronger (compared to adults) asymmetric movement with respect to proximity to water, with higher movement probabilities to near‐water locations than away from these locations.

Local survival of day‐old ducklings during the first year of life was time‐specific and very low (means for different strata/states 0·01–0·08) because of high rates of emigration and prefledging mortality.
The population dynamical implications of covert infections in host–microparasite interactions
Authors: Boots Michael , Greenman Jon , Ross David , Norman Rachel , Hails Rosie , Sait Steven
Published: December 2004

The persistence of parasites that are only seen in intermittent outbreaks has intrigued ecologists. Long the subject of speculation, there is now evidence that viral insect diseases can cause covert as well as overt infections.

Typically, infection leads to overtly diseased individuals that are infectious and die as a result of the disease, but it can also produce other individuals that show a covert, non‐infectious pathology, which is typically asymptomatic. Covertly infected individuals do not die as a result of infection, although they may be affected sublethally such that their reproductive output falls, they may transmit the covert infection vertically and, crucially, they may convert at some rate to overt infectious individuals. In this way the parasites are able to persist in host populations and can be detected only by the use of molecular techniques.

Here, we apply novel analytical techniques to a general host–parasite modelling framework and examine the population dynamical consequences of such covert infections.

The interplay between various stabilizing and destabilizing forces leads to a highly complex pattern of host dynamics, including a theoretically intriguing pinch point. Covert infections may be stabilizing or destabilizing depending on the specific characteristics of the interaction, particularly in relation to the rate of conversion from covert to overt infection.

In general terms, intermediate rates of conversion are stabilizing, while high and low rates may each destabilize the host population. In contrast, there is no consistent pattern for the role of vertical transmission because, in some cases, high levels are stabilizing while in others they are destabilizing.

Thus, our results demonstrate that relatively subtle pathogen effects such as covert infections can have important and novel dynamical impacts on the host–pathogen interaction. It also suggests that the effects of covert infection are likely to be system‐specific and information may be required on a system‐by‐system basis in order to make predictions.
Caddisfly diapause aggregations facilitate benthic invertebrate colonization
Authors: McCabe Declan J. , Gotelli Nicholas J.
Published: December 2004

We used natural and manipulative field experiments to examine the effects of caddisfly (Trichoptera) diapause aggregations on benthic macroinvertebrates communities in a Vermont river.

Natural substrates with aggregations of Neophylax and Brachycentrus (Trichoptera: Uenoidae and Brachycentridae) had higher species richness than did substrates lacking aggregations. Aggregations of caddisfly cases added to artificial substrates (bricks) also accumulated greater abundance, species density (number of species per unit area), and species richness (number of species per standard number of individuals) than did control bricks.

Low‐density, uniformly spaced, Brachycentrus cases accumulated higher species density and species richness than did an equivalent density of clumped cases. Similarly, empty Neophylax cases accumulated higher diversity than did cases still occupied by Neophylax pupae.

Although natural substrates had higher species richness than artificial substrates, substrate type did not change qualitatively the effect of caddisfly aggregations on species richness.

We subsampled individuals randomly from aggregations and control surfaces to provide an estimate of species richness unbiased by abundance. Expected species richness was higher in aggregations than on control surfaces. These results suggest that caddisfly aggregations increase species density by altering the shape of the species–abundance distribution as well as by accumulating individuals and species passively.

We conclude that caddisfly diapause aggregations increase habitat complexity and facilitate colonization of other benthic species.
Literacy, readability and cultural barriers: critical factors to consider when educating older African Americans about anticoagulation therapy
Authors: Wilson Feleta L. , Racine Eric , Tekieli Virginia , Williams Barbara
Published: December 2004

• The number of patients on anticoagulation therapy has increased dramatically over the past two decades. Yet, few studies have examined the psychosocial barriers of low literacy, culture and inappropriate patient education materials used to teach older African Americans about their anticoagulation therapy.

• The aims of this study were to investigate literacy levels among older patients, and evaluate the readability and determine the cultural sensitivity of written information used in an anticoagulation management clinic.

• A descriptive, correlational design was used. Patients' (n = 62) knowledge levels and the readability and cultural sensitivity of written materials were examined. The Rapid Estimate of Adult Literacy in Medicine (REALM) was used to measure reading skills of patients, while the SMOG formula (a formula for assessing readability) was used to test the readability of written educational materials used in an Anticoagulation Management Clinic. A Knowledge Information Profile, developed for this study by one of the authors (Wilson), was used to measure patient knowledge about warfarin, medication side‐effects and food sources of vitamin K. A modified, culturally sensitive and easy‐to‐read pamphlet was used as an alternative teaching tool in the study.

• The results of the study revealed the average self‐reported for highest grade completed in school was twelfth grade; however, the actual mean reading skills were between seventh and eighth grade. The readability of the written information was three to four grades higher than patients' reading abilities. None of the patient education materials were culturally sensitive.

• This study underscores the importance of having information that is understandable and culturally relevant to prevent the outcome of internal bleeding. Nurses have a vital role in educating patients and ensuring that teaching materials are appropriate for the target population.
Implementing aromatherapy in nursing and midwifery practice
Authors: Rawlings Fran , Meerabeau Liz
Published: December 2004

• This paper reports the results of a small qualitative study of nurses and midwives who had undertaken a course in aromatherapy, one of the most popular complementary therapies in the UK. In particular, it examines barriers to putting their knowledge into practice.

• Participants had completed the aromatherapy course between 9 months and 2 years previously, and worked in a variety of settings. All were approached via their employing NHS trust.

• The interviews which took place in the clinical area were tape recorded and generally lasted for about 40 minutes.

• Data were analysed using the procedure outlined by Colaizzi (1978) Significant statements were clustered into themes, guided by whether they had a ‘look alike/feel alike’ quality, and were subsequently validated with the informants.

• The main themes discussed in this paper are the personal and professional benefits that respondents reported from undertaking the course, organizational issues and the frustrations they experienced because of delays in implementing changes in practice.
Having a child with asthma – quality of life for Swedish parents
Authors: Dalheim‐Englund Ann‐Charlotte , Rydström Ingela , Rasmussen Birgit Holritz , Möller Christian , Sandman Per‐Olof
Published: December 2004

Background.  Asthma is the most common chronic childhood disease. Childhood asthma contributes significantly to morbidity among children and has a significant impact on the quality of life (QoL) and daily routines of both the children and their parents.

Aim and objective.  The purpose of this study was to investigate how Swedish parents of children with asthma experience their QoL, and to investigate whether there were differences concerning QoL between parents within the same family. The purpose was also to investigate possible connections between their QoL and background variables.

Method.  A total of 371 parents of children with asthma (57% mothers and 43% fathers) participated in the study. The Paediatric Asthma Caregiver's Quality Of Life Questionnaire (PACQLQ) was used to measure the parents’ QoL, i.e. how the child's asthma interferes with the parents’ normal activities and how it has made them feel.

Results.  The findings show that most parents of children with asthma evaluated their QoL as close to the positive end of the scale, and there was close agreement in the scoring between parents within the same family. Significant associations were found between parents’ lower QoL outcome and living in the North of Sweden. There were also significant associations between fathers’ lower QoL outcome and having a child younger than 13 years of age and mothers’ lower QoL outcome and having a child with severe asthma. Although the result shows that a child's asthma did not influence the parents’ QoL to a greater degree, it is still important for healthcare workers to help these parents to sustain and improve their well‐being.

Conclusions.  The fact that they just evaluated their QoL during the preceding week only, and did so at the time when their children were being treated with asthma medication, might have influenced the results in a positive direction.
Varicose veins: a qualitative study to explore expectations and reasons for seeking treatment
Authors: Palfreyman Simon John , Drewery‐Carter Kim , Rigby Kathryn , Michaels Jonathan A , Tod Angela Mary
Published: December 2004

Background.  Patients experience a wide range of symptoms from varicose veins and are seeking treatment from health care providers. However, there is little data on the relative effectiveness of the treatments available. Patients are therefore often confronted with a choice regarding treatment that they are ill‐equipped to make. This lack of certainty and the resultant potential for variability in treatment decisions can mean that patients have expectations that are unrealistic or unfulfilled.

Aims and objectives.  The aim of our study was to explore patients’ expectations and reasons for seeking treatment for varicose veins. Additional aims included the exploration of symptoms associated with varicose veins and their impact on quality of life.

Design.  Qualitative study conducted in a large NHS Trust.

Methods.  A total of 16 patients, who had been referred to a specialist vascular service for the treatment of varicose veins, were recruited. Semi‐structured interviews were used to explore the patients’ reasons for seeking treatment. Framework analysis was used to analyse the data from the anonymized transcripts.

Results.  Participants attributed a wide range of symptoms to their varicose veins, and were actively seeking treatment with the expectation that they would gain symptom relief. The symptoms attributed to their varicose veins had a significant negative impact on their quality of life and lifestyle. Improving the cosmetic appearance of their legs was seen as a secondary benefit.

Conclusions.  The perceived symptoms of varicose veins can impact on lifestyle and quality of life. Patients seek treatment with the expectation of treatment outcomes that are not supported by robust clinical evidence. Appropriate education and management of such expectations are an essential step in caring for this group of patients.

Relevance to clinical practice.  Nurses are caring for patients with varicose veins in a range of clinical settings. When caring and providing information for this group of patients, nurses need to be aware of the impact of varicose vein symptoms and to understanding that patients may have unrealistic expectations or invalid reasons for seeking treatment.
Bed articles for nursing care – state of the art in two German hospitals
Authors: Boggatz Thomas , Grabowski Kati , Winne Heike , Gunzelmann Frank , Tuschke Hagen , Dassen Theo
Published: December 2004

Background.  Bed articles are basic instruments for positioning. Research about this topic has concentrated on evidence for better practice. However, little is known about what practitioners really do.

Aims and objectives.  This study intended to identify the most common bed articles used for positioning in two German hospitals, and to determine the decision‐maker for their application and the purposes and criteria for their choice.

Methods.  Nursing experts from 100 wards were interviewed with the help of a structured questionnaire and based on these data a list of the 10 most frequent devices was compiled.

Results.  Supporting the body position was the most frequent intervention performed by German nurses, mainly with the help of hydraulic beds, pillows and blankets. Nurses were the main decision‐makers for the use of these bed articles. Their choice was mainly based on work experience and patients’ desires. Guidelines and literature played a minor role in this process.

Relevance to clinical practice.  If nurses, despite the medical doctors’ role as the main decision‐maker in German hospitals, exert significant influence on this aspect of care, they can support their position by evidence‐based practice.
Reflection, the way to professional development?
Authors: Gustafsson Christine , Fagerberg Ingegerd
Published: December 2004

Background.  Many studies have focused on reflection and the advantages that can be gained from the practice of reflection among Registered Nurses (RNs) but, what are the implications of the nurses’ reflections, what do they reflect about, and how do they deal with their reflections?

Aims and objectives.  The aim of this study was to describe the RNs’ experiences of reflection in relation to nursing care situations, and to understand how RNs use reflection in their daily work. What are the implications of the nursing care situations that the RNs’ reflect upon? What consequences did the practice of reflection have in nursing care situations in relation to the RNs professional development?

Design and method.  The study was carried out with interviews and the phenomenographic method. Interviews were carried out with four RNs. The choice of informants was made with purposive sampling with the aim of finding informants who could bring the kind of knowledge that was necessary for the study.

Results.  The qualitative differences regarding the RNs’ experiences of reflection were categorized as follows: to reflect (to think back – consider, mirroring, to reflect before and reflect after, to use experiences), nursing care situations (ethical considerations, to have courage, to use one's imagination, empathy) and consequences (to meet the unique, empathy, development). Finally, the findings were implicated in the model of professional development.

Conclusion.  By using reflection as a tool, many advantages can be gained in the development of nursing care. Encouraging RNs to reflect upon nursing situations, in order to promote the nurse's professional development, will imply better nursing care for the patients. The model for professional development implies a simplified representation of the thoughts pertaining to professional nursing development.

Relevance to clinical practice.  The relevance for clinical practice will be to understand the contents of the RNs reflections, to recognize the advantages of reflective practice and how and when to use such measures. Furthermore, to show how the model for professional development can be used in order to create a framework for evaluating these observations and consequently, for expressing tacit knowledge.
The development and pilot evaluation of a nutrition education intervention programme for pregnant teenage women (food for life)
Authors: Wrieden W. L. , Symon A.
Published: December 2004

Background  A healthy diet in pregnancy is important for both maternal and infant health but this may be difficult to achieve particularly for groups such as teenage pregnant women, many of whom are from disadvantaged backgrounds. To our knowledge this is the first report of a practical nutrition education programme for this group in the UK.

Method  An intervention was designed incorporating seven informal food preparation sessions, which allowed opportunities for discussion of nutritional, and other topics (e.g. food safety and well‐being in pregnancy). Midwives in a community centre setting led the sessions.

The acceptability of the package to participants and midwives was recorded and pre‐ and post‐intervention data collected on sociodemographic details, dietary intake (using an eating‐habits questionnaire and a 24‐h dietary recall) and cooking skills.

Results  The midwives found the package easy to follow and use. The 16 (of the 120 invited) women who attended found the courses helpful but objective evaluation of dietary intake was not possible because of poor compliance.

Conclusions  The nutrition education programme was favourably received by midwives and the women who participated. However recruitment was problematic and alternative methods of delivering and evaluating such a package should be investigated.
High GAD65 autoantibody levels in nondiabetic adults are associated with HLA but not with CTLA‐4 or INS VNTR
Authors: Rolandsson O. , Hägg E. , Janer M. , Rutledge E. , Gaur L. K. , Nilsson M. , Hallmans G. , Lernmark Å.
Published: December 2004

Abstract.  Rolandsson O, Hägg E, Janer M, Rutledge E, Gaur LK, Nilsson M, Hallmans G, Lernmark Å (Umeå University, Umeå, Sweden; Institute for Systems Biology and University of Washington, Seattle, WA, USA). High GAD65 autoantibody levels in nondiabetic adults are associated with HLA but not with CTLA‐4 or INS VNTR. J Intern Med 2003; 253: 447–453.

Objectives.  To explore the relationship between genetic background and antibody levels in a nondiabetic population. We evaluated if high levels of autoantibodies against the 65 kDa isoform of glutamic acid decarboxylase (GAD65Ab), were associated with high‐risk genes, i.e. HLA, CTLA‐4 and INS VNTR genes.

Design and subjects.  Seventy‐five (M/F 39/36) subjects exceeding the 95th percentile of GAD65 autoantibody index and 75 age and sex matched subjects below the 95th percentile, randomly selected amongst participants in the Västerbotten Intervention Programme.

Methods.  The GAD65 Ab were measured in a radioligand‐binding assay. HLA class II typing was performed by an oligoblot hybridization method. CTLA‐4 repeat length was analysed and divided into short forms and long forms. Class I and class III alleles of INS VNTR were detected. Differences in distribution were tested by Pearson chi‐square with Yates correction. Odds ratios (OR) were used to compare groups calculated with Cochran's and Mantel–Haenszel statistics.

Results.  The DQB1*0201‐DQA1*0501‐DRB1*03 haplotype was increased in subjects with high GAD65Ab levels (P = 0.04). This increase seemed to be explained by a difference in haplotype frequencies amongst men (P = 0.01). Calculating OR showed a significant association between the DQB1*0201‐DQA1*0501‐DRB1*03 haplotype and elevated levels of GAD65Ab in all subjects (OR 2.2, 95% CI 1.02–4.9) as well as in men (OR 4.6, 95% CI 1.3–15.9). There was no association between high levels of GAD65Ab and either INS VNTR or CTLA‐4 polymorphisms.

Conclusion.  Our study suggests that adult males with the DQB1*0201‐DQA1*0501‐DRB1*03 haplotype tend to develop high GAD65Ab titres. As none of these subjects have developed diabetes these data suggest that HLA may be important in GAD65Ab formation but that additional factors are required for the progression to overt type 1 diabetes.
Life‐threatening thrombotic complications of relative polycythaemia
Authors: Biswas M. , Prakash P. K. , Cossburn M. , Myers K. , Hanna F.
Published: December 2004

Abstract.  Biswas M, Prakash PK, Cossburn M, Myers K, Hanna F. Life‐threatening thrombotic complications of relative polycythaemia (Case Report). J Intern Med 2003; 253: 481–483.

Relative polycythaemia refers to raised haematocrit with normal red cell mass. Plasma volume may be reduced. This condition is associated with acute hypoxia, smoking, alcohol and diuretics. We describe two life‐threatening thrombotic events in two patients with relative polycythaemia under age 40 years. The first had myocardial infarction and on admission haemoglobin was 21.6 g dL−1. The second developed pulmonary embolism and haemoglobin was 19.1 g dL−1. Both patients received antithrombotic measures and isovolumetric venesection. Sixteen patients (age <40 years) who attended our accident and emergency department in 1 year had a haemoglobin level of >18.0 g dL−1. Recognition of relative polycythaemia in at risk‐individuals may help reduce thrombotic risk.
DNA vaccines: a review
Authors: Liu M. A.
Published: December 2004

Abstract. Liu MA (Strasbourg, France and Karolinska Institute, Stockholm, Sweden). DNA vaccines: a review (Review). J Intern Med 2003; 253: 402–410.

The DNA vaccines are simple rings of DNA containing a gene encoding an antigen, and a promoter/terminator to make the gene express in mammalian cells. They are a promising new approach for generating all types of desired immunity: cytolytic T lymphocytes (CTL), T helper cells and antibodies, whilst being a technology that has the potential for global usage in terms of manufacturing ease, broad population administration and safety. This review gives an overview of the mechanisms, preclinical and clinical efficacy of DNA vaccines, and point out the limitations of the first generation of such vaccines, and some of the promising second‐generation developments. This technology is also being utilized in the field of proteomics as a tool to elucidate the function of genes. The breadth of applications for DNA vaccines thus ranges from prophylactic vaccines to immunotherapy for infectious diseases, cancer, and autoimmune and allergic diseases.
The reliability of different formulae to predict creatinine clearance
Authors: Verhave J. C. , Baljé‐Volkers C. P. , Hillege H. L. , De Zeeuw D. , De Jong P. E.
Published: December 2004

Abstract.  Verhave JC, Baljé‐Volkers CP, Hillege HL, de Zeeuw D, de Jong PE (University Medical Center Groningen, Groningen University, Institute of Drug Exploration, Groningen, the Netherlands). The reliability of different formulae to predict creatinine clearance. J Intern Med 2003; 253: 563–573.

Objectives.  Creatinine clearance (CCR) is a commonly used tool to measure glomerular filtration rate (GFR) in clinical practice. This tool requires collection of 24‐h urine, which is quite bothersome. Several different formulae have been used to estimate GFR using plasma creatinine and other easy formulae to obtain biometrical data. We examined 10 formulae and compared them with actually measured CCR in a large sample of the general population.

Design.  Cross‐sectional cohort study.

Setting.  University hospital outpatient clinic, a population based study.

Subjects.  A total of 8592 inhabitants of the city of Groningen, 28–75 years of age. The cohort is enriched for microalbuminuria.

Results.  In general, the formulae did not give an accurate estimation of CCR, particularly not in male and in obese subjects. Six formulae, including the Cockcroft–Gault gave a fairly good estimation of CCR in the overall population and in subgroups of specific gender, body mass index and age. All formulae however, gave an underestimation of the measured CCR in higher ranges of CCR and an overestimation in the lower ranges. Moreover, the age‐related decline of CCR is hard to approximate with a formula.

Conclusions.  We conclude that formulae to estimate CCR in the general population, although giving a fairly good estimate of mean CCR, do not offer reliable data on CCR in the upper and lower ranges and do not adequately estimate the age–related decline in CCR.
Current status of blood substitute research: towards a new paradigm
Authors: Winslow R. M.
Published: December 2004

Abstract. Winslow RM (University of California, San Diego, CA, USA). Current status of blood substitute research: towards a new paradigm (Minisymposium). J Intern Med 2003; 253: 508–517.

For many reasons, haemoglobin, modified to prolong its circulation time, seems to be the optimal choice for a cell‐free O2 carrier (blood substitute) because of its capacity to reversibly bind O2 in the lung and release it in tissue. After refining methods to prepare highly purified haemoglobin solutions and to chemically or genetically modify haemoglobin to overcome renal toxicity and to prolong retention time, a number of unwanted effects were observed in human clinical trials. These included symptoms referable to the GI tract, elevated pancreatic enzymes and hypertension, presumed to be the result of vasoconstriction. Studies on the mechanism of vasoconstriction induced by haemoglobin, using new techniques to investigate the microcirculation have led to a surprising new paradigm for the design of safe and effective solutions. These include increased O2 affinity (low P50) and increased viscosity and oncotic pressure. These second‐generation solutions hold greater promise for clinical development.
Future generations of red blood cell substitutes
Authors: Chang T. M. S.
Published: December 2004

Chang TMS (Artificial Cells & Organs Research Center, McGill University, Montreal, Quebec, Canada). Future generations of red blood cell substitutes (Minisymposium). J Intern Med 2003; 253: 527–535.

Polyhaemoglobins (PolyHb) and perfluorochemicals are in advanced phase III clinical trials and conjugated haemoglobins in phase II clinical trial. New recombinant human haemoglobin with no vasoactivity is being developed. A soluble macromolecule of PolyHb–catalase–superoxide dismutase is being studied as an oxygen carrier with antioxidant properties. New artificial red blood cells that are more like RBC are being developed. One is based on haemoglobin lipid vesicles. A more recent one is based on nano‐dimension artificial red blood cells containing haemoglobin and RBC enzymes with membrane formed from composite copolymer of polyethylene glycol–polylactic acid. Their circulation time is double that of PolyHb.