bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of inhibitor epitope profile on the neutralizing effect against plasma‐derived and recombinant factor VIII concentrates in vitro
Authors: Astermark J. , Voorberg J. , Lenk H. , DiMichele D. , Shapiro A. , Tjönnfjord G. , Berntorp E.
Published: September 2003

Summary.  The inhibitory capacity of plasma samples from 24 patients with severe haemophilia A and high‐responding inhibitors were evaluated in a concentrate‐based assay using two plasma‐derived (Haemate and Monoclate‐P) and three recombinant (Helixate, Recombinate and ReFacto) factor VIII concentrates and correlated with the corresponding epitope profile. In most, but not all, inhibitor plasmas with a relatively low reactivity against the von Willebrand‐containing product Haemate, the main epitopes were located in the FVIII light chain. The reactivities within the group of recombinant products varied in that the reactivity against the B‐domain deleted ReFacto was in general higher than that against Recombinate and Helixate. This difference did not correlate with any particular epitope profile and indicates that the B‐domain, type of formulation and/or purification procedures may have an impact on the inhibitor reactivity in vitro. The ratio between the inhibitor titres in the concentrate‐based assay and the Bethesda assay was dependent on the inhibitor plasma and concentrate used. Taken together, our results show that the reactivity of inhibitor plasmas varies considerably between different FVIII concentrates and that it does not fully correlate with the epitope profile. Potential clinical implications of the observed differences in inhibitor reactivity are discussed.
Progression of HIV infection and mortality by hepatitis C infection in patients with haemophilia over 20 years
Authors: Quintana M. , Del Amo J. , Barrasa A. , Pérez‐Hoyos S. , Ferreros I. , Hernández F. , Villar A. , Jiménez V. , Bolúmar F.
Published: September 2003

Summary.  Hepatitis C virus (HCV) infection is an important cause of mortality in human immune deficiency virus (HIV)‐positive haemophiliacs. This study describes progression to AIDS, death from HCV end‐stage liver disease (ESLD) and all‐cause mortality over 20 years. All HIV‐positive haemophiliacs in La Paz University Hospital were included in this cohort. HIV seroconversion was estimated using mathematical techniques for interval‐censored data from 1979 to 1985. Poisson regression was used to estimate rates of AIDS, death from ESLD and all causes in different periods: before 1988, 1988–89, 1990–91, 1992–93, 1994–95, 1996–97 and 1998–2001 using competing risk models. Among 383 cohort members, global AIDS incidence was 9.7 per 100 person‐years, peaking in 1992–93 and dropping by 87% in 1998–2001 compared with before 1988 [incidence rate ratio (IRR) 0.13; 95% CI: 0.03–0.53]. Overall mortality was 7.5 per 100 person‐years, was highest from 1992 to 1997, and fell by 66% in 1998–2001 compared with before 1988 (IRR 0.34; 95% CI: 0.14–0.81). Eighteen (5%) persons died of ESLD which represented 19% of deaths before 1988, 4% during 1988–89, 1990–91 and 1992–93, 2% in 1994–95, 10% in 1996–97 and 33% in 1998–2001. Overall death rate from ESLD was 0.5 cases per 100 person‐years with no statistically significant trend observed over time. Important reductions in HIV disease progression to AIDS and death have been observed from 1998 to 2001, and can be attributed to highly active antiretroviral therapy. Although no increase in the rate of HCV‐related deaths can be demonstrated, HCV accounts for an increasing proportion of deaths in the recent years.
An acquired factor VIII inhibitor in association with a myeloproliferative/myelodysplastic disorder presenting with severe subcutaneous haemorrhage
Authors: Biss T. , Crossman L. , Neilly I. , Hanley J.
Published: September 2003

Summary.  We report a 71‐year‐old man who presented with severe subcutaneous and later psoas muscle haemorrhage in the presence of a raised white cell count and hepatosplenomegaly. A circulating factor VIII (FVIII) inhibitor was detected and bone marrow morphology confirmed the presence of a myeloproliferative/myelodysplastic disorder. Initial treatment with high dose FVIII followed by recombinant factor VIIa was unsuccessful. Haemorrhage was controlled by the administration of activated prothrombin complex concentrate (FEIBA; Baxter healthcare, CA, USA) in combination with prednisolone, cyclophosphamide and i.v. immunoglobulin. The inhibitor became undetectable 14 weeks after presentation. The white cell count responded initially to hydroxyurea and later to cyclophosphamide. There have been only two previous reports of acquired haemophilia A in association with myelodysplastic disorders and no previous report of an association with a myeloproliferative disorder.
Psychological aspects and coping in haemophilic patients: a case–control study
Authors: Canclini M. , Saviolo‐Negrin N. , Zanon E. , Bertoletti R. , Girolami A. , Pagnan A.
Published: September 2003

Summary.  Although enormous progress has been made in recent years in the field of haemophilia, some problems still await solution, such as the risk of sudden haemorrhage, the sequelae of haemophilic arthropathy and social activities. We, therefore, carried out a case–control study in which some psychological dimensions (social expectations, tendency to depression, state of anxiety and self‐esteem) were evaluated in a group of 60 haemophiliacs. A control group was formed of 78 healthy subjects matched for age, socio‐economic class and level of education. The methodology used was the administration of self‐assessment questionnaires which investigate and provide a quantitative measure of psychological dimensions. The results can be subjected to statistical analysis. Three self‐assessment questionnaires were used: (i) the Marlowe–Crowne scale, (ii) the Beck Inventory (1978) version modified by Cusinato (1990) and (iii) the S.T.A.I. – form. Our aim was to evaluate: (i) whether there are significant differences in the considered psychological aspects between haemophiliacs and healthy subjects; (ii) whether there is a significant correlation between the psychological dimensions considered in the haemophiliacs and in the healthy subjects. The results showed that the haemophiliacs have a good psychological adaptation to their disease with the exception of their greater tendency to have less self‐esteem than do the healthy subjects. As far as concerns the second aim, we found than self‐esteem correlated with all the psychological variables investigated. This information could indicate the enormous importance that the psychological variable ‘self‐esteem’ plays in haemophiliacs with respect to whether or not they develop depressive disorders and/or anxiety states.
On‐demand vs. prophylactic treatment for severe haemophilia in Norway and Sweden: differences in treatment characteristics and outcome
Authors: Steen Carlsson K. , Höjgård S. , Glomstein A. , Lethagen S. , Schulman S. , Tengborn L. , Lindgren A. , Berntorp E. , Lindgren B.
Published: September 2003

Summary. Using an 11‐year panel of 156 Norwegian and Swedish patients with severe haemophilia, and including retrospective case‐book data from birth, we compared the differences in the haemophilia‐related resource use between on‐demand and prophylactic treatment. Patients treated on‐demand had more surgery (arthrodeses, prostheses implantations and synovectomies) and more days lost from work. Median annual factor‐concentrate consumption among adults (18+) was 211 000 IU [interquartile range (IQR) 154 000–268 000] or 3 024 IU kg−1year−1for patients on prophylactic treatment and 55 000 IU (IQR 28 000–91 000) for on‐demand patients (780 IU kg−1 year−1). This was partly explained by the fact that the median dose per kg body weight was twice as great 28, (IQR 24–32) for prophylaxis compared with 14 (IQR 12–16) for on‐demand. Prescribed dose per kg body weight was found to be an important factor explaining the variation in total annual factor‐concentrate consumption per patient for both types of treatment. Other variables included in the panel‐data regression analysis were the number of weeks on secondary prophylaxis for on‐demand patients and age, body weight and type of haemophilia for children (0–17 years) on prophylaxis. Differences were consistently substantial and will affect both costs and benefits of the two treatment strategies.
Comparison of papilla healing following sulcular full‐thickness flap and papilla base flap in endodontic surgery
Authors: Velvart P. , Ebner‐Zimmermann U. , Ebner J. P.
Published: September 2003

Aim  To compare the loss of papilla height when using the papilla base incision (PBI) or the standard papilla mobilization incision in marginal full‐thickness flap in cases with no evidence of marginal periodontitis.

Methodology  Twelve healthy patients referred for surgical treatment of persisting apical periodontitis, who were free from periodontal disease and had intact interdental papillae, were included in the study. The preoperative papilla height was recorded by measuring the distance between a reproducible coronal point on the tooth and the most coronal point of the papilla. The flap design consisted of two releasing incisions connected by a horizontal incision. The marginal incision involved the complete mobilization of the entire papilla in one interproximal space, and the PBI in the other interproximal space. The PBI consisted of a shallow first incision at the base of the papilla and a second incision directed to the crestal bone creating a split thickness flap in the area of the papilla base. Further, apically, a full‐thickness flap was raised. In the other interproximal space, the buccal papilla was carefully incised and elevated completely. Following flap retraction, standard root‐end resection and root‐end filling were performed. Flap closure was achieved with microsurgical sutures. The PBI was sutured with two to three interrupted sutures (size 7/0) and the elevated papilla was reapproximated with vertical mattress sutures, which were removed 3–5 days after the surgery. The height of the interdental papilla was evaluated preoperatively and postoperatively after 1 month and at the 3‐month recall, using plaster replicas. The loss of papilla height was measured using a laser scanner. Twelve papilla‐paired sites were evaluated. The results were statistically analysed using the t‐test.

Results  Complete closure of the wound was achieved in all treated sites followed by uneventful healing in all patients. The total mobilization of the papilla resulted in loss of papilla height of 1.10 ± 0.71 mm at 1 month and 1.25 ± 0.81 mm at the 3‐month recall. At the 3‐month recall, the retraction had increased in nine sites, whereas in three sites, the loss of height had slightly diminished compared to 1 month. In contrast, after the PBI, only minor changes could be detected: 0.07 ± 0.09 mm at 1 month and 0.10 ± 0.15 mm at 3 months. There was a significant difference between the two incision techniques studied (P < 0.007).

Conclusions  In patients with healthy marginal periodontal conditions, the PBI allows rapid and predictable recession‐free healing, whereas complete mobilization of the papilla led to a marked loss of the papilla height. In aesthetically relevant areas, the use of the PBI is recommended, to avoid opening of the interproximal space, when periradicular surgical treatment is necessary.
Root canal treatment of three‐rooted maxillary first and second premolars – a case report
Authors: Soares J. A. , Leonardo R. T.
Published: September 2003

Aim  To report the diagnosis and successful clinical management of a patient with anatomical variation in maxillary first and second premolars.

Summary  Maxillary premolars have a highly variable root canal morphology, but it is rare, especially in the second premolar, to find three canals. This article describes the diagnosis and clinical management of first and second premolars with three canals and three separate roots, drawing particular attention to radiographic interpretation and access refinements.

Key learning points 

Clinicians should be aware of anatomical variations in maxillary premolars and be able to apply this knowledge in radiographic and clinical interpretation.

Access cavity refinements may be required for stress‐free entry to complex anatomy.

Complex premolar anatomy may be predictably managed following its identification and negotiation.
Facilitation of iontophoretic drug delivery through intact and caries‐affected dentine
Authors: Puapichartdumrong P. , Ikeda H. , Suda H.
Published: September 2003

Aim  To investigate the facilitative role of iontophoresis in drug delivery through intact and caries‐affected dentine into the pulp.

Methodology  Forty‐eight intact dentine or caries‐affected dentine discs were prepared from freshly extracted human third molars. The hydraulic conductance was measured before and after the experiments. Drug diffusion with and without iontophoresis (0.05 mA, 10 min) was evaluated using a split‐chamber device. The enamel side chamber was filled with metronidazole (MN), sodium salicylate (SS) or naproxen sodium (NA), while the pulpal side was circulated with phosphate buffered saline (PBS) and pressurized (15 cmH2O). Samples were collected after 1 h. Drug concentrations of the pulpal side solution were determined using a spectrophotometer. Then, electrical impedance of each dentine disc was measured. Finally, the dentine disc surfaces were observed by scanning electron microscopy.

Results  Drug diffusion was significantly influenced by iontophoresis, caries‐induced changes in dentine and the drugs used (three‐way anova, P < 0.05). The diffusion of all the drugs through caries‐affected dentine was significantly less than that through intact dentine (independent t‐test, P < 0.05). Also, iontophoresis facilitated the diffusion of all the drugs through intact and caries‐affected dentine. The drug diffusion of SS was significantly higher than MN and NA (one‐way anova, P < 0.05), independent of iontophoresis.

Conclusions  Presence of dental caries may inhibit drug diffusion through dentine into the pulp. However, iontophoresis could enhance the delivery of ionized drugs through both intact and caries‐affected dentine.
Diagnostic accuracy of endoscopy in periradicular surgery – a comparison with scanning electron microscopy
Authors: Von Arx T. , Montagne D. , Zwinggi C. , Lussi A.
Published: September 2003

Aim  To compare the accuracy of endoscopic diagnostics with the scanning electron microscope (SEM) in evaluating elements of periradicular surgery.

Methodology  The material consisted of 22 extracted human molars, which were subjected to the following treatments: orthograde root‐canal obturation, root‐end resection and root‐end cavity preparation with diamond‐coated sonic microtips. After each step, the cut root face was inspected with an endoscope, and subsequently, the roots were duplicated for SEM evaluation. Endoscope findings were compared to those obtained with SEM serving as the ‘gold standard’ with a blinded observer. The presence of the following structures was assessed including specificity and sensitivity: isthmuses, accessory canals, obturation gaps, microfractures and chipping of cavity margins.

Results  The specificity and sensitivity of the identification of isthmuses or accessory canals was 100% each for the endoscope compared to SEM. The sensitivity of identification of obturation gaps, crack formation or chipping ranged between 73 and 95% (except intradentine cracks with only 36% sensitivity). The specificity of the same parameters ranged between 77 and 100% for the endoscope compared to SEM.

Conclusions  With the exception of intradentine cracks, the endoscope accurately identified microstructures following root‐end resection and root‐end preparation. The endoscope could be considered for use during intraoperative diagnostics in periradicular surgery.
Measurement of periapical pressure created by occlusal loading
Authors: Dobó‐Nagy C. , Fejérdy P. , Angyal J. , Harasztosi L. , Daróczi L. , Beke D. , Wesselink P. R.
Published: September 2003

Aim  To develop an in vitro model in which the pressure in the periapical tissues can be measured during loading.

Methodology  Extracted human maxillary central incisors were embedded in resin blocks that had physical characteristics similar to those of bone and periodontal ligament. Each tooth was loaded with 20, 40, 50, 60, 75, 85, 100, 200, 300 and 450 N vertical forces from the incisal edge of the crown on three consecutive occasions. A minute resistor embedded in the periapical space was used to detect apical pressure changes during occlusal loading. The ratio of apical pressure changes (ΔP) to the loading force changes (ΔF) was calculated.

Results  The periapical pressure detected was in direct proportion to the loading force. The mean value of ΔP/ΔF was 5.994 kPa N−1 (SD = 2.04).

Conclusions  Direct proportionality was found between the coronal loading and the apical hydrostatic pressure. The ΔP/ΔF ratio determined in this study makes it easier to estimate the apical hydrostatic pressure values during occlusal loading of single‐rooted teeth. In this study, the apical pressure generated under occlusal loading was the same magnitude as that estimated with the finite element method.
A model of human hunting impacts in multi‐prey communities
Authors: Rowcliffe J. Marcus , Cowlishaw Guy , Long Janice
Published: September 2003

The hunting of wild animals for consumption by people currently threatens many species with extinction. In the tropics, where the threat is most acute, hunting frequently targets many prey species simultaneously, yet our understanding of the dynamics of hunting in such multi‐prey systems is limited. This study addressed this issue by modelling the effects of human hunters on prey population dynamics in a multi‐species prey community. Both pursuit hunting (in which offtake depends partly on hunters’ prey preferences) and trap hunting (in which the offtake is determined solely by random processes) were considered as submodels.

The pursuit hunting submodel was validated against studies of subsistence hunting in tropical forests, while the trap hunting submodel was validated against data from five studies of offtake rates by snare hunters in subSaharan Africa. In all cases, observed prey removal rates were predicted well by the model.

Simulations demonstrated the emergence of distinctive prey profiles at different intensities of hunting, related to sequences of overexploitation dependent on species’ vulnerabilities to exploitation.

Synthesis and applications. A model is developed to explore the impacts of harvesting on multi‐species prey communities. Model predictions can be used to aid the interpretation of incomplete monitoring data, such as snapshots of the species taken by hunters. This will improve our ability to assess the sustainability of multi‐species hunting systems using the limited information typically available in these cases.
Predicting the impacts of harvesting using structured population models: the importance of density‐dependence and timing of harvest for a tropical palm tree
Authors: Freckleton R. P. , Matos D. M. Silva , Bovi M. L. A. , Watkinson A. R.
Published: September 2003

Structured population models are used in a range of forms to predict the long‐term behaviour of populations of economic or conservation interest. Such models rarely include density‐dependence and do not account explicitly for the ordering of events within a generation.

We analysed a model for the harvesting of adults of the edible palm Euterpe edulis in which the role of density‐dependence had been clearly defined. We modified the timing of harvesting in relation to the point in the life cycle at which populations were censused.

It is shown that the timing, form and intensity of harvesting are all important in determining asymptotic population behaviour. If harvesting affects only those individuals that were recorded as being adults at the start of a year, then the model predicts that all adults may be harvested without population eradication. In contrast, if harvesting also affects individuals moving from the next smaller size class during the course of a year then populations can, under some forms of harvesting, tolerate much lower levels of harvesting.

If density‐dependence is not taken into consideration, predictions of population responses to harvesting may be erroneous. A review of transition matrices for woody plants indicates that many of these may have been derived from populations subject to strong population regulation.

Synthesis and applications. In the specific case of E. edulis our model shows that, although populations appear to be robust to very high levels of harvesting, when modelled as affecting only reproductive adults, this conclusion may be sensitive to varying the timing and form of harvest, and to the assumption that only reproductive individuals are removed. Structure population models used to determine levels of harvesting should account for the existence of density‐dependence as well as its timing.
Pollination of Coffea canephora in relation to local and regional agroforestry management
Authors: Klein A.‐M. , Steffan‐Dewenter I. , Tscharntke T.
Published: September 2003

Pollination of crops depends on local agricultural management and the quality of adjacent habitats. Lowland coffee Coffea canephora, is an important tropical cash crop. Fruit set depends on cross‐pollination by bees, so inadequate pollination leads to reduced yield. In this study we analyse the relationship between bee pollinators, fruit set in coffee, and the local and regional agroforestry systems to identify the optimal conditions for pollinators.

We analysed the abundance and species composition of coffee flower‐visiting bees in 15 agroforestry systems differing in distance to forest (important for wood‐nesting species), light intensity (important for ground‐nesting species), blossom cover of coffee and noncoffee‐flowering plants, and species richness of flowering plants (as pollen and nectar resources) in Central Sulawesi (Indonesia). We examined which factors were most important for optimal pollination success. We carried out bagged and open pollination experiments in each agroforestry system, to measure the pollination efficiency of 15 bee species.

The number of social bee species decreased with distance to forest, whereas the number of solitary bee species increased with light intensity (less shade) and greater quantities of blossoms.

Fruit set of open pollinated flowers (as opposed to manually cross‐pollinated flowers) increased with the diversity and abundance of flower‐visiting bees. In the agroforestry systems studied, a bee community of 20 species or more led to a higher fruit set (95%) than a species‐poor bee community of six species (70% fruit set).

Pollination activity by members of the species‐rich solitary bee assemblage led to higher levels of fruit set than that arising from pollination activity by members of the more abundant social bee assemblage.

Synthesis and applications. A species‐rich and abundant bee assemblage will facilitate high pollination success in lowland coffee. This will increase fruit set and coffee yield. Farmers can encourage different species of bees through simple management measures such as growing coffee in shade beneath a variety of trees; by pruning trees to increase levels of sunlight and numbers of flowering herbs; and by increasing the availability of nesting sites for solitary bees. Weed control and the use of herbicides should be kept to a minimum so that a diverse nectar and pollen resource is available to bees throughout the year. Natural forests and forest fragments should be preserved in the vicinity of coffee agroforestry systems (< 500 m) so that forest‐nesting social bees can travel easily to the coffee fields to pollinate the flowers.
Annual losses of weed seeds due to predation in organic cereal fields
Authors: Westerman P. R. , Wes J. S. , Kropff M. J. , Van Der Werf W.
Published: September 2003

Post‐dispersal seed losses in annual arable weed species are poorly quantified, but may be of significance for natural population control, especially if they can be manipulated. We hypothesized that weed seed predation on the soil surface was significant, so we measured rates in the field to estimate annual seed losses due to predation.

Temporal patterns of weed seed losses due to predation (‘demand’) as well as weed seed production (‘supply’) were measured from May to June until harvest in August 1999 and 2000 during 2‐week exposure periods in four organic cereal fields in the Netherlands. The proportion of weed seeds lost to predators Mi (number of seeds consumed per number of seeds exposed per 14 days) was measured, using cards containing seeds of Stellaria media, Chenopodium album or Avena fatua. Seed production, Yi (number of seeds per m2 per 14 days), was measured in 2000, using seed traps.

Annual seed loss due to predation, M̄ (number of seeds consumed per number of seeds produced per year), was calculated based on Mi and the exposure period of seeds to predators, starting with seed shed and ending with seed burial. The importance of the length of the exposure period on total seed loss was explored using a model.

The temporal trend in Mi was consistent among farms and years: high in June and early July, lower in the second half of July and negligible in August and after harvest. Total seed production varied considerably among fields, i.e. 800–16 000 seeds per m2 per year. The timing of peak seed production also varied substantially.

Calculated M̄ ranged from 32% to 70%, when assuming continuous exposure of seeds to predators from seed shed till crop harvest. When exposure was limited to 2 or 4 weeks after seed shed, M̄ decreased to 18–57% or 28–67%, respectively. Differences between fields and weed species were mainly due to differences in the timing of seed shed.

Synthesis and applications. Our results suggest that seed predation in organic cereal fields is an important factor shaping the population dynamics of arable weeds. A combination of environmental conditions (hot and dry weather) and agricultural practices (an early crop sowing) can advance weed phenology and postpone seed burial, resulting in higher proportions of weed seed loss to predation in cereals.
The marine survival and growth of wild and hatchery‐reared Atlantic salmon
Authors: Jonsson Nina , Jonsson Bror , Hansen Lars Petter
Published: September 2003

Catches of Atlantic salmon Salmo salar L. decreased in the 1980s and 1990s over its entire area in the North Atlantic and smolts were often released for stock enhancement. However, there are questions about their survival and performance relative to fully wild fish. This paper reports on the survival and sea growth of River Imsa salmon released from 1981 to 1999 as 1‐ and 2‐year‐old hatchery and wild smolts.

Survival was significantly higher for wild than hatchery fish. Hatchery salmon released as 2‐year‐old smolts had lower survival, were captured more in coastal than freshwaters, grew more slowly and attained maturity younger than corresponding 1‐year‐old smolts.

The survival rate of hatchery fish released as 2‐year‐old smolts, but not 1‐year‐olds and wild smolts, decreased during the 1980s and 1990s. Growth rates at sea, adult size and the proportion of multi‐sea‐winter fish of all three groups also decreased over time.

Catches in coastal relative to freshwaters were higher for two‐ than one‐sea‐winter fish. Salmon captured in coastal water were greater in length than those captured in rivers. Mean specific growth rate at sea was similar for wild and hatchery salmon released as 1‐year‐old smolts, and higher than in hatchery fish released as 2‐year‐olds.

The proportion of two‐sea‐winter salmon correlated positively with the specific growth rate in the first year at sea. Total capture of wild adult salmon in rivers and Norwegian home waters each year correlated positively with the specific growth rate in the first year at sea. The same correlation held for hatchery fish released as 2‐ but not 1‐year‐old smolts.

Synthesis and applications. The coastal fishery was size‐selective in reducing the size and age of salmon. Releases of 1‐year‐old smolts were financially more profitable than those of 2‐year‐olds. Decreasing production of River Imsa salmon since 1981 was chiefly caused by reduced sea‐age at maturity and growth rate at sea of both hatchery and wild fish. A counteracting measure would be to reduce the size selectivity of the salmon fisheries.
Evidence for indigenous selection and distribution of the shea tree, Vitellaria paradoxa, and its potential significance to prevailing parkland savanna tree patterns in sub‐Saharan Africa north of the equator
Authors: Maranz S. , Wiesman Z.
Published: September 2003

Aim  Woody vegetation patterns in African savannas north of the equator are closely connected to human presence, but the distinctions between natural and anthropogenic landscapes have not been clear to many observers. Criteria for identifying savanna landscapes on a continuum of intensity of anthropic impact are explored.

Methods  A key savanna tree species, Vitellaria paradoxa (Sapotaceae), was used as model for evaluating anthropic impact. Fruits harvested from tree populations across the species range were analysed for variation in traits valued by indigenous peoples. A simple selection index was used to scale tree populations from a hypothetical wild state to a hypothetical domesticated state. Index values were compared with trait values along climate zone gradients and evaluated in the context of indigenous savanna management practices and historical species distribution reports.

Results  Trait values such as fruit size and shape, pulp sweetness, and kernel fat content show a significant influence of temperature and rainfall. At the same time, the mean values of groups of traits vary perpendicular to the general climatic zone gradient. Selection index values between Vitellaria populations vary up to sixfold, with highest values in central Burkina Faso. Comparison of present day Vitellaria distribution with historical range limits show range expansion by human migration.

Main conclusions  The prevalence of major economic tree species in the savannas of Africa north of the equator is a strong indicator of human involvement in tree dispersal. This conclusion is supported by paleobotanical evidence and by recent Vitellaria range expansion as a result of human migration. The presence of high mean values of several Vitellaria fruit traits in central Burkina Faso suggests that selection for desired characteristics has occurred. The impact of indigenous savanna peoples on woody species composition and spatial distribution is probably much greater than usually thought and is the result of a deliberate strategy of altering the landscape to provide needed human resources.
The trans‐Pacific zipper effect: disjunct sister taxa and matching geological outlines that link the Pacific margins
Authors: McCarthy Dennis
Published: September 2003

AimTo combine analyses of trans‐Pacific sister taxa with geological evidence in order to test the hypothesis of the existence of a Panthalassa superocean.

LocationThe study is concerned with taxa, both fossil and extant, from East Asia, Australia, New Zealand, South America and North America.

MethodsPhylogenetic and distributional analyses of trans‐Pacific biota were integrated with geological evidence from the Pacific and circum‐Pacific regions.

ResultsA series of recent biogeographical analyses delineates a zipper‐like system of sister areas running up both margins of the Pacific, with each section of western North and South America corresponding to a particular section from East Asia/Australia/New Zealand. These sister areas coincide neatly with a jigsaw‐like fit provided by the matching Mesozoic coastlines that bracket the Pacific.

Main conclusionsThe young age (<200 Myr) of oceanic crust, the matching Mesozoic circum‐Pacific outlines, and a corresponding system of interlocking biogeographical sister areas provide three independent avenues of support for a closed Pacific in the Upper Triassic–Lower Jurassic. The hypothesis of the existence and subsequent subduction of the pre‐Pacific superocean Panthalassa is not only unnecessary, it conflicts with this evidence. Panthalassa‐based paleomaps necessitate the invention of dozens of additional hypotheses of species‐dependent, trans‐oceanic dispersal events, often involving narrow‐range taxa of notoriously limited vagility, in order to explain repeated examples of the same biogeographical pattern. Removing the vanished‐superocean hypothesis reunites both the matching geological outlines and all the disjunct sister taxa. In brief, what appears to be a multi‐era tangle of convoluted, trans‐oceanic distributions on Panthalassa‐based paleomaps is actually a relatively simple biogeographical pattern that is explainable by a single vicariant event: the opening and expansion of the Pacific.
Adaptive latitudinal trends in the mandible shape of Apodemus wood mice
Authors: Renaud Sabrina , Michaux Johan R.
Published: September 2003

Aim Size and shape of the mandible are investigated across the latitudinal range of the European wood mouse (Apodemus sylvaticus), in order to address the relative importance of genetic structure, insularity, and geographical gradient in patterning morphological variation. Results are compared with those on two Asiatic species of wood mice, A. argenteus and A. speciosus.

Location The European wood mouse is sampled by a set of trapping localities including both, islands and mainland populations, as well as the four genetic groups identified in previous studies. The localities cover a latitudinal gradient from 55° N to 36° N.

Methods Different Fourier methods are applied to the outlines of mandibles and their results compared in the case of A. sylvaticus. All provide similar results and allow a quantification of the size and shape variations across the geographical range of the European wood mouse. Using the method allowing for the best reduction of the informative data set, a comparison of the European wood mouse with the two Asiatic species was performed.

Results Within the European wood mouse A. sylvaticus, a strong latitudinal gradient in mandible shape overrides the influence of insularity and genetic structure. Yet, random morphological divergence in insular conditions can be identified as a secondary process of shape differentiation. Size displays no obvious pattern of variation, neither with insularity or latitude. A comparison with two other species of wood mice suggests that a similar latitudinal gradient in mandible shape exists in different species, mandibles being flatter in the north and wider in the south.

Main conclusion The latitudinal gradient in mandible shape observed in the three species of wood mice is interpreted as an intraspecific adaptive response to gradual changes in feeding behaviour.
A method using indicator plants to map local climatic variation in the Kangerlussuaq/Scoresby Sund area, East Greenland
Authors: Karlsen Stein R. , Elvebakk Arve
Published: September 2003

AbstractAimTo describe a method for mapping local climatic variation using plants as temperature indicators.

LocationThe study area is situated on the northern side near the mouth of the fiord Kangerlussuaq/Scoresby Sund, East Greenland (70–71°N). The study area consists of three subareas, divided into 136 1 × 1 km study units. It was selected because of its very strong climatic gradient as shown by data from four meteorological stations in the area, with mean July temperatures ranging from 2.7 to 9.3 °C.

MethodsThe method is based on the fact that most vascular plant species occurring in the Arctic have circumpolar distribution patterns obviously limited by temperatures to a varying extent. By comparing the circumpolar distribution maps with summer temperatures, species are grouped according to minimum temperature demands and assigned indicator values. In the field, frequency and abundance of all indicator species and the occurrence of habitats are recorded in all study units. Indicator values and abundance data are entered into a formula of Index of Thermophily, and the resulting values are modified according to deviating habitat diversity and cover of unproductive areas. Index values are supposed to reflect local climatic conditions, and the results are tested by comparing with temperatures measured in the field.

ResultsA total of 147 taxa, 139 of these being vascular plants, were defined in six categories of temperature indicators. The Index of Thermophily values calculated for the 136 study units show a complex pattern and a strong positive relationship with the temperatures measured during 1991 and 1993, withr2values of 0.82 and 0.92, respectively. The unmodified Index version gave slightly lower correlations. A very strong gradient is demonstrated from the extremely cold coastal community of Uunarteq/Kap Tobin to more protected sites only 20 km inland, where a similar climate is found at 1100 m altitude. Favourable slopes also produce a favourable climate at altitudes of 700 m. The warmest sites are the south‐facing slopes of five deep river gorges, all with similar Index values and the occurrence ofSalixshrubs. The results are used to make a local bioclimatic map, including allowances for topographic features and detailed knowledge on the occurrence of concentrations of thermophilous plants. Here fourteen climate classes are mapped in detail, and these mapping units can be correlated to four of five subzones present in the Arctic on a circumpolar scale. The correlation with these subzones shows that the study area has the strongest horizontal climate gradient recorded from the Arctic.

Main conclusionsThe strong positive correlation between the calculated Index of Thermophily values and measured temperatures indicate that the present method is successful in mapping local bioclimatic heterogeneity in the Arctic.
The decay of similarity with geographical distance in parasite communities of vertebrate hosts
Authors: Poulin Robert
Published: September 2003

Aim The rate at which similarity in species composition decays with increasing distance was investigated among communities of parasitic helminths in different populations of the same host species. Rates of distance decay in similarity of parasite communities were compared between populations of fish and mammal hosts, which differ with respect to their vagility and potential to disperse parasite species over large distances.

Location Data on helminth communities were compiled for several populations of three mammalian host species (Ondatra zibethicus, Procyon lotor and Canis latrans) and three fish host species (Perca flavescens, Catostomus commersoni and Esox lucius) from continental North America.

Methods Distances between localities and similarity in the composition of helminth communities, the latter computed using the Jaccard index, were calculated for all possible pairs of host populations within each host species. Similarity values were then regressed against distance to see if they decayed at exponential rates, as reported for plant communities; the significance of the regressions was assessed using randomization tests.

Results The number of hosts examined per population did not correlate with the number of helminth species found per population, and thus sampling effort is unlikely to have confounded the results. In four (two mammals and two fish) of the six host species, similarity in helminth communities decayed exponentially with distance. When the log of similarity is plotted against untransformed distance, the slopes obtained for the two fish species are lower than those obtained for the two mammalian host species.

Main conclusions Similarity in the composition of parasite communities appears to decay exponentially with increasing distance in some host species, but not in all host species. The rate of decay is not necessarily associated with the vagility of the host. Although distance decay of similarity is generally occurring, it seems that other ecological processes, related either to the host or its habitat, can obscure it.
The range expansion of the great‐tailed grackle (Quiscalus mexicanus Gmelin) in North America since 1880
Authors: Wehtje Walter
Published: September 2003

Aims  This study aimed to document and describe the current range expansion of the great‐tailed grackle (Quiscalus mexicanus Gmelin) into the USA. By examining the habitat associations and pattern of spread of this species, I intended to determine the factors responsible for this remarkable expansion by a tropical species into a temperate environment.

Location  This study focused on the spread of the great‐tailed grackle in the continental USA, Canada and Baja California.

Methods  I used published records, museum specimens, and egg collections to document this range expansion from 1880 through 2002. In addition I surveyed large portions of Arizona, Nevada, southern Utah and southern California for great‐tailed grackles during 2000 and 2001. The data gathered was used to create maps in order to quantify the rate of spread of this species.

Results  Between 1880 and 2000 the great‐tailed grackle expanded its breeding range in the USA from c. 64,000 km2 to more than 3,561,000 km2, an increase of 5530%. The average annual rate of increase is 3.4%, but has lessened during the past 20 years. Northward movement in the eastern portion of the range has slowed down, reflecting this decrease. However, in the central and western portion of the species range, the rate of northward movement is still accelerating. During this expansion, the average time between first sighting in a state and first breeding was 5.8 years. The species has become less migratory during its range expansion, wintering in 17 of the 20 states where it breeds.

Main conclusions  This range expansion has been marked by great‐tailed grackles preferring human‐modified environments as breeding grounds, especially in the western states. This association appears to benefit the species in two ways; nest predation is lessened in such areas compared with natural conditions, whereas human activities tend to generate an abundant and consistent food supply for feeding offspring. Wintering birds are often associated with cattle feed lots and large‐scale dairies, where abundant waste grain provides them with a reliable food supply. Given the continued human population increase throughout large areas of the western USA, the great‐tailed grackle will continue its range expansion.
Signalling mechanism coupled to 5‐hydroxytryptamine4 receptor‐mediated facilitation of fast synaptic transmission in the guinea‐pig ileum myenteric plexus
Authors: Galligan J. J. , Pan H. , Messori E.
Published: September 2003

5‐hydroxytryptamine (HT)4 receptor agonists stimulate gastrointestinal motility partly by facilitating acetylcholine release from myenteric neurones. However, the signalling mechanisms that couple 5‐HT4 receptor activation to increased transmitter release in the myenteric plexus are unknown. We used conventional intracellular electrophysiological methods to record fast excitatory postsynaptic potentials (fEPSPs) from neurones in the guinea‐pig ileum myenteric plexus preparation. The substituted benzamide, renzapride, acted at 5‐HT4 receptors to facilitate fEPSPs. This response was mimicked by forskolin, an activator of adenylate cyclase. Facilitation of fEPSPs by renzapride and forskolin was not blocked by treating tissues with pertussis toxin (PTX) (2 h, 2 μg mL−1). Facilitation of fEPSPs caused by renzapride was blocked by the non‐selective protein kinase inhibitors, staurosporine (1 μmol L−1) and H‐8 (30 μmol L−1) and by the selective protein kinase A (PKA) inhibitor, H‐89 (10 μmol L−1). These data indicate that 5‐HT4 receptors act via a PTX‐resistant mechanism to activate PKA. Protein kinase A activation leads to an increase in transmitter release from myenteric nerve terminals and a facilitation of fast excitatory synaptic transmission.
Cholinergic and nitrergic innervation of ICC‐DMP and ICC‐IM in the human small intestine
Authors: Wang X.‐Y. , Paterson C. , Huizinga J. D.
Published: September 2003

With functional evidence emerging that interstitial cells of Cajal (ICC) play a role in smooth muscle innervation, detailed knowledge is needed about the structural aspects of enteric innervation of the human gut. Conventional electronmicroscopy (EM), immunohistochemistry and immuno‐EM were performed on the musculature of the distal human ileum focusing on ICC associated with the deep muscular plexus (ICC‐DMP) and intramuscular ICC (ICC‐IM). ICC‐DMP could be identified by EM but not by c‐Kit immunohistochemistry. Immuno‐EM revealed that ICC‐DMP were innervated by both cholinergic and nitrergic nerves, and were the only cells to possess specialized synapse‐like junctions with nerve varicosities and gap junction contacts with smooth muscle cells. c‐Kit positive ICC near the deep muscular plexus were not ICC‐DMP, but ICC‐IM located in septa. ICC‐IM were innervated by both cholinergic and nitrergic nerves but without specialized contacts. Varicosities of both nerve types were also found scattered throughout the musculature without specialized contact with any ICC. No ICC showed immunoreactivity for neuronal nitric oxide synthase. As ICC‐DMP form synapse‐like junctions with cholinergic and nitrergic nerves and gap junction contacts with muscle cells, it is hypothfesized that ICC‐DMP hold a specialized function related to innervation of smooth muscle of the human intestine.
Intragastric distribution of a standardized meal in health and functional dyspepsia: correlation with specific symptoms
Authors: Piessevaux H , Tack J , Walrand S , Pauwels S , Geubel A
Published: September 2003

Abstract  In functional dyspepsia, abnormal intragastric distribution of a test meal has been identified but has never been correlated to any symptom pattern. The aim of this study was to compare the intragastric distribution of a meal between functional dyspepsia patients and controls, and to correlate distribution with symptom patterns, using scintigraphic gastric emptying studies. In forty patients with functional dyspepsia and 29 healthy volunteers, scintigraphic planar images were obtained immediately after ingestion of a mixed radiolabelled test meal and every 20 min for 2 h. The images of the stomach were divided into proximal and distal compartments. The mean intragastric distribution was similar in patients and controls. Over the whole test, 18 (45%) and 20 (50%) patients had a distal redistribution of the solid and liquid phase of the meal, respectively, while proximal retention of these phases was found in 13 (33%) and 9 (23%) patients. Early satiety was associated with early distal redistribution of the liquid phase and fullness was associated with late proximal retention. This study shows similar intragastric distribution of a test meal in health and functional dyspepsia. Within the patient group, an association between abnormal intragastric distribution patterns and symptom profiles was found, which might be related to different pathophysiological mechanisms.