bluuebunny/crossref_metadata_2025 huggingface dataset:
Myoblast migration is prevented by a calpain‐dependent accumulation of MARCKS
Authors: Dedieu S. , Mazères G. , Poussard S. , Brustis J.‐J. , Cottin P.
Published: November 2003

Abstract Calpains, also called calcium activated neutral cysteine proteases are presently known to play pivotal roles in physiological and biological phenomena such as signal transduction, cell spreading and motility, apoptosis, regulation of cell cycle and regulation of muscle cell differentiation. Concerning this last point, calpains have been shown to play a crucial role during the earlier myogenesis. In this study we have analyzed the involvement of calpains during an important step of myogenesis: myoblast migration. Our findings show that myoblast migration was drastically reduced when the expression of μ‐ and m‐calpain was decreased. We have also observed that MARCKS (myristoylated alanine rich C kinase substrate), a protein localized at focal adhesion sites, was significantly accumulated when the expression levels of calpains were decreased. Also, using phorbol myristate acetate, (an activator of PKC) and plasmids carrying the full‐length cDNA of MARCKS or a cDNA fragment lacking the phosphorylation site domain, we demonstrated that normal myoblast migration is dependent on MARCKS phosphorylation and localization.
Tyrosine kinase‐mediated cell signalling in the activation of Mytilus hemocytes: possible role of STAT‐like proteins
Authors: Canesi Laura , Betti Michele , Ciacci Caterina , Citterio Barbara , Pruzzo Carla , Gallo Gabriella
Published: November 2003

Abstract In bivalve molluscs, cell‐mediated immunity is carried out by circulating hemocytes, resembling the monocyte/macrophage lineage of vertebrates, that can kill the microbes through phagocytosis and various cytotoxic reactions. Previous data demonstrated that activation of MAPKs (Mitogen Activated Protein Kinases) is involved in the response of mussel hemocytes (Mytilus galloprovincialis Lam.) to bacterial challenge. In this work, the possibility that modulation of components of tyrosine kinase‐mediated cell signalling may participate in the activation of mussel hemocytes was investigated. Cell pre‐treatment with the macrophage activator IFNγ significantly increased the bactericidal activity of mussel hemocytes towards E. coli. Human recombinant IFNγ stimulated tyrosine phosphorylation of different members of STAT‐like proteins (Signal Transducers and Activators of Transcription), as evaluated by Western blotting of hemocyte protein extracts with specific anti‐phospho‐STAT antibodies. A similar increase in phosphorylation of immunoreactive STATs was observed in hemocytes incubated with E. coli, this indicating that tyrosine phosphorylation of STAT‐like members represents a physiological step in hemocyte activation. IFNγ lead to persistent phosphorylation of immunoreactive STAT1, a transcription factor that plays a critical role in innate immunity towards Gram negative bacteria in mammalian systems; moreover, hemocyte pretreatment with IFNγ significantly increased bacteria‐induced STAT1 phosphorylation, whereas IFNα did not. IFNγ also transiently affected the phosphorylation state of different MAPKs. The extent and time course of MAPK phosphorylation induced by IFNγ were distinct from those elicited by either IFNα or bacterial challenge. Overall, the results indicate that the hemocyte function can be modulated by heterologous cytokines and bacterial signals that act in concert through tyrosine kinase‐mediated transduction pathways converging on STAT‐ and MAPK‐like members.
Involvement of myosin in intracellular motility and cytomorphogenesis in Micrasterias
Authors: Oertel Anke , Holzinger Andreas , Lütz‐Meindl Ursula
Published: November 2003

Myosin was detected on Western blots of Micrasterias denticulata extracts by use of antibodies from different sources. Inhibitors with different targets of the actomyosin system, such as the myosin ATPase‐blockers N‐ethylmaleimide (NEM) and 2,3‐butanedione monoxime (BDM), or the myosin light chain kinase inhibitor 1‐(5‐iodonaphthalene‐1‐sulfonyl)‐1H‐hexhydro‐1,4‐diazapine (ML7), had similar effects on intracellular motility during cell development in the green alga Micrasterias, thus pointing towards a participation of myosin in these processes. The drugs markedly altered the mode of postmitotic nuclear migration, slowed down cytoplasmic streaming, changed cell pattern development and prevented normal chloroplast distribution and spreading into the growing semicell. In addition, an increase and dilatations in ER cisternae and marked morphological changes of the Golgi system were observed by transmission electron microscopy after exposure of growing cells to BDM.

Neither BDM nor ML7 exhibited any effect on the distribution or arrangement of the cortical F‐actin network nor on the F‐actin basket around the nucleus, characteristic of untreated growing Micrasterias cells (J Cell Sci 107 (1994) 1929). This is particularly interesting since BDM caused disintegration of the microtubule system co‐localized to the F‐actin cage during normal nuclear migration. Together with the fact that other microtubules not connected to the F‐actin system remained uninfluenced by BDM, this observation is evidence of an integrative function of myosin between the cytoskeleton elements.
Impact of glafenine hydrochloride on human endothelial cells and human vascular smooth muscle cells: a substance reducing proliferation, migration and extracellular matrix synthesis
Authors: Schöber Wolfgang , Tran Quoc Bao , Muringaseril Matthew , Wiskirchen Jakub , Kehlbach Rainer , Rodegerdts Enno , Wiesinger Benjamin , Claussen Claus D , Duda Stephan H
Published: November 2003

The aim of this study was to examine the effects of glafenine hydrochloride (a nonsteroidal anti‐inflammatory drug) on proliferation, clonogenic activity, cell‐cycle, migration, and the extracellular matrix protein tenascin of human aortic smooth muscle cells (haSMCs) and human endothelial cells (ECs) in vitro.

HaSMCs and ECs were seeded in tissue culture flasks. The cells were treated for 4 days with glafenine hydrochloride (10 μM, 50 μM, 100 μM). Half of the treated groups were incubated again with glafenine hydrochloride, the other half received medium free of glafenine hydrochloride every 4 days until day 20. The growth kinetics and clonogenic activity were assessed. Cell cycle distribution was investigated by FACS, migratory ability was evaluated, and effects on extracellular matrix synthesis were assessed by immunofluorescence.

Glafenine hydrochloride inhibited the proliferation and clonogenic activity of haSMCs and ECs in a dose‐dependent manner. A block in the G2/M phase and a reduction in the G1 phase occurred. The migratory ability of haSMCs was impaired in a dose‐dependent manner and the extracellular matrix protein tenascin was reduced. As glafenine hydrochloride has the ability to fully inhibit proliferation and to partially inhibit migration in haSMCs, it could be an interesting substance for further research in the field of restenosis therapy.
Women have later onset than men in schizophrenia—but only in its paranoid form. Results of the DSP project
Authors: Salokangas Raimo K.R. , Honkonen Teija , Saarinen Soile
Published: November 2003

According to the literature, schizophrenia begins in men earlier than in women. It has been argued that the gender-bound age difference is due to the protective antidopaminergic effect of estrogens in women. However, the effect of gender on the age of onset may vary between different types of schizophrenias, and can also be modulated by marital status and by age at onset of illness. Comprehensive data were collected on 3306 DSM IIR schizophrenia patients, aged 15–64 years, who had been discharged from psychiatric hospitals in Finland in 1982, 1986 and 1990. The age of onset of illness (AOI) was defined by the age at the first admission (AFA). Male patients were admitted earlier than female patients, and a small second peak in women appeared at the age of 40–44. However, there were no gender differences in AFA within diagnostic subgroups, except in paranoid schizophrenia in which AFA was lower in men than in women even when marital status was taken into account. Within paranoid schizophrenia, this effect of gender was significant only in those of the patients whose AFA was higher than 30 years. It is suggested that there is no gender difference in AOI in early onset schizophrenia. In later onset, paranoid schizophrenia, the illness seems to manifest in women later than in men.
Lithium augmentation in venlafaxine non-responders: an open study
Authors: Bertschy G. , Ragama-Pardos E. , Aït-Ameur A. , Muscionico M. , Favre S. , Roth L.
Published: November 2003

Thirteen major depressive patients not responding to a 4-week venlafaxine 300 mg treatment were eligible for a 4-week open trial of lithium addition. Two patients had to stop lithium for a possible moderate serotonin syndrome and five patients became responders, including one dramatic response and two semi-rapid responses.
Gender differences and outcome in schizophrenia: a 2-year follow-up study in a large community sample
Authors: Usall J. , Ochoa S. , Araya S. , Márquez M. ,   NEDES group (Assessment Research Group in Schizophrenia)
Published: November 2003

This study examined gender differences in the short-term (2 years) course of schizophrenia in a sample of 200 schizophrenic (DSM-IV criteria) outpatients (74 women and 126 men). Number and length of hospitalizations during the prospective follow-up were recorded. After 2 years, men were found to have more hospitalizations and longer stays than women. Among subjects who had at least one hospitalization (12 women and 38 men), men had greater length of hospitalization. In conclusion, schizophrenic women had a significantly better short-term outcome.
Clients with long-term mental disabilities in a Swedish county—conditions of life, needs of support and unmet needs of service provided by the public health and social service sectors
Authors: Jansson Lennart , Sonnander Karin , Wiesel Frits-Axel
Published: November 2003

Objective

The purpose of the study was to identify and describe conditions of life and needs of support and public service for clients with a mental disability in a Swedish county population.

Methods

Public health care and social service providers identified clients and completed a questionnaire concerning the clients’ conditions of life and their special needs. A consecutively recruited sample of clients completed a similar questionnaire.

Results

Totally, 1261 clients were identified. The prevalence of clients with mental disabilities was in the urban and rural areas, 6.4/1000 inhabitants and 4.5/1000 inhabitants, respectively. The most prevalent unmet need (42.9%) was to participate in social and scheduled activities. Almost half of the group was reported to need support in activities of daily living. Clients living in urban settings more often needed support with activities of daily living (P < 0.001), whereas clients living in rural settings more often needed support with job training (P < 0.001) or finding work (P < 0.01). Clients and psychiatric care providers reported the needs of the clients in the same areas; however, clients reported a fewer number of needs than did the care providers.

Conclusions

By using both psychiatric care and social service providers, effective case findings of clients with a mental disability were possible to achieve. In general, there was high agreement between psychiatric care providers and clients regarding the clients’ number of needs of support and their unmet needs of service. However, at the individual level, the agreement between client and psychiatric care providers was lower.
Behavioural disturbances following Japanese B encephalitis
Authors: Monnet François P.
Published: November 2003

Clinically, Japanese B encephalitis (JBE) is often overlooked as its occurrence in Western countries is rare. However, its neurological, cognitive and psychiatric sequelae constitute a major public health problem in the Far East where JBE is endemic. European and American subjects may however experience the JBE when returning from a Far East journey. In such cases, misdiagnosis is frequent because of the unawareness of psychiatrists and physicians. The present review, therefore, documents the behavioural and cognitive sequelae of JBE. This reactivates the debate concerning the vaccination against the virus all the more that the literature enlightens the importance of the vaccination for those who undertake frequent and extensive tourist excursions to the Orient but still discusses it for occasional travellers. Following is a case-report of a young western European post-graduate student who has contracted JBE by experiencing an acute febrile delirium during an unusual short stay in South East Asia. Pyramidal syndrome, Parkinsonism and amnesia were the prominent acute deficits. Whereas these faded in great part during convalescence, emotional and behavioural instability associated with affective involvement, obsessive–compulsive symptoms and cognitive impairments appeared. A partial recovery was however obtained with neuroleptics, lithium and following electro-convulsive therapy. Organic personality syndrome was persistent and thereafter constituted the main sequelae syndrome. Hypersomnia and several enuretic episodes persisted.
Alternative splicing generates a novel non‐secretable resistin isoform in Wistar rats1
Authors: Del Arco A , Peralta S , Carrascosa J.M , Ros M , Andrés A , Arribas C
Published: November 2003

Resistin is a secreted adipose tissue hormone that belongs to the resistin‐like molecule family. We report here a new alternatively spliced isoform of the rat resistin gene, named S‐resistin (short resistin), detected in adipose tissue by reverse transcription‐polymerase chain reaction (RT‐PCR). A comparison of this cDNA variant and genomic sequences indicates the lack of the second exon containing the secretory consensus signal. Both cDNAs, resistin and S‐resistin, were carboxy‐tagged with FLAG epitope and transiently expressed in cultured cell lines. While the resistin‐FLAG construct gives the expected pattern for a secretion protein, the S‐resistin‐FLAG construct yielded a predominant nuclear staining. These results indicate that this splicing event regulates the fate and probably the function of the mature protein.
Functional consequences of an in vivo mutation in exon 10 of the human GLUT1 gene
Authors: Lange Peter , Gertsen Elena , Monden Ingrid , Klepper Jörg , Keller Konrad
Published: November 2003

The functional consequences of an in vivo heterozygous insertion mutation in the human facilitated glucose transporter isoform 1 (GLUT1) gene were investigated. The resulting frameshift in exon 10 changed the primary structure of the C‐terminus from 42 in native GLUT1 to 61 amino acid residues in the mutant. Kinetic studies on a patient's erythrocytes were substantiated by expressing the mutant cDNA in Xenopus laevis oocytes. K
m and V
max values were clearly decreased explaining pathogenicity. Targeting to the plasma membrane was comparable between mutant and wild‐type GLUT1. Transport inhibition by cytochalasin B was more effective in the mutant than in the wild‐type transporter. The substrate specificity of GLUT1 remained unchanged.
Mineral dust and global tropospheric chemistry: Relative roles of photolysis and heterogeneous uptake
Authors: Bian Huisheng , Zender Charles S.
Published: November 2003

We investigate the influence of mineral dust on tropospheric chemistry in the present climate at the global scale. The analysis examines the effects of dust on photolysis and heterogeneous uptake, operating independently and together. In numerical experiments the size‐resolved, time‐varying mineral dust distribution predicted by the global Dust Entrainment and Deposition (DEAD) model perturbs the gas phase species in a global chemical transport model (University of California at Irvine (UCI) CTM). We find that the photolysis perturbation dominates limited regions in the low to middle troposphere, while heterogeneous uptake dominates the rest of atmosphere. Coupling of the photochemical and heterogeneous effects of dust is weak in the global mean but moderate in dusty regions, where coupling is sometimes responsible for more than 20% of local O3 changes. Ozone and odd‐nitrogen concentrations are perturbed in opposite directions by photolysis and heterogeneous chemistry, resulting in a weak net change. However, both processes decrease the concentrations of OH and HO2. The global mean change due to dust is −0.7% for tropospheric O3, −11.1% for OH, −5.2% for HO2, and −3.5% for HNO3. Large seasonal signals are present near dust source regions. Over the North African region and tropical Atlantic Ocean downwind, OH decreases by −66.8%, six times more than the global mean reduction. Interestingly, net photolysis‐induced annual mean O3 changes are greater in the Southern Hemisphere than in the Northern Hemisphere, where significantly more dust and O3 precursors reside. In polar regions, O3 change is dominated by transported O3 and is not sensitive to local dust concentration. O3 change due to photolysis depends not only on dust vertical structure but also on the availability of O3 precursors. O3 change due to heterogeneous reactions on dust is sensitive to dust vertical structure, mainly through the influence of temperature on uptake rates.
Filament eruption without coronal mass ejection
Authors: Choudhary Debi Prasad , Moore Ronald L.
Published: November 2003

We report characteristics of quiescent filament eruptions that were not associated with coronal mass ejections (CMEs). We examined 12 quiescent filament eruptions, each of which was located far from disk center (≥0.7 RSun) in diffuse remnant magnetic fields of decayed active regions, was well observed in full‐disk movies in Hα and Fe XII, and had good coronagraph coverage. Of the 12 events, 9 were associated with CMEs and 3 were not. Even though the two kinds of eruption were indistinguishable in their magnetic setting and in the eruptive motion of the filament in the Hα movies, each of the CME‐producing eruptions produced a two‐ribbon flare in Hα and a coronal arcade and/or two‐ribbon flare in Fe XII, and each of the non‐CME‐producing eruptions did not. From this result, and the appearance of the eruptive motion in the Fe XII movies, we conclude that the non‐CME‐associated filament eruptions are confined eruptions like the confined filament eruptions in active regions.
Effect of strain rate on constitutive properties for the shear failure of intact granite in seismogenic environments
Authors: Kato Aitaro , Ohnaka Mitiyasu , Yoshida Shingo , Mochizuki Hiromine
Published: November 2003

To investigate how the constitutive parameters prescribing the slip‐dependent law for the shear failure of intact rock are affected by strain rate, we conducted a series of triaxial fracture experiments at a strain rate in the range from 10−5 to 10−7/s in seismogenic environments using Tsukuba granite samples. The experimental results showed that the peak shear strength decreases modestly with a reduction in strain rate, according to a logarithmic law. The reduction rate tested at wet conditions was larger than at dry conditions. It was found that the maximum slip‐weakening rate slightly increases with an increase in strain rate at wet conditions. This indicates that the mechanical instability of the shear failure process is slightly enhanced by an increase in strain rate.
Third molar position following Bionator treatment
Authors: Dolce Calogero , Wheeler Timothy T. , Fusco Adam D. , Johnson Paul D. , Ruskin James D. , Oberdofer Martha L.
Published: November 2003

Third molar eruption is an unpredictable event. The position of the third molar continuously changes during development. The purpose of this study was to evaluate the influence of Bionator treatment on third molar position against an untreated control group. A Bionator is a loose‐fitting intra‐oral appliance that postures the mandible forward, thereby producing skeletal and dentoalveolar changes. Data were obtained from direct measurements of existing longitudinal panoramic radiographs taken during the course of a randomized study investigating Class II malocclusion treatment options. The following variables were analyzed: mandibular third molar depth in relation to the cemento‐enamel junction of the second molar; anterior–posterior (A–P) position in relation to the anterior border of the ramus; and angulation registered at the functional occlusal plane. Analysis of variance and ordinal logistic regression were used to investigate relationships between the variables. Angulation of the third molars changed substantially with varying depths (p<0.0008) and A–P positions
(p<0.0001), but did not appear to relate appreciably to dental
age (p>0.5) or treatment condition (p>0.4). The A–P
position was significantly correlated to dental age (p>0.004) and
Bionator treatment (p<0.0001), whereas depth was marginally
associated with dental age (p<0.07) and not influenced by
Bionator treatment (p>0.5). Third molars adopt a position further anterior in relation to the ramus with Bionator treatment than they do in controls. As dental age increases, Bionator use appears to positively influence third molar position.
Accuracy, confidence and consistency in diagnosing Class III malocclusion with diagnostic records: a two‐center study
Authors: Ngan Peter , White Carl , Shuen Suwen , Beck Michael , Fields Jr. Henry
Published: November 2003

The objective of this study was to determine the accuracy, confidence and consistency in diagnosing the Class III malocclusion in children by diagnostic records. Ten orthodontists from the state of West Virginia and 20 from the state of Ohio were asked to classify the dental and skeletal occlusion of eight patients. Six of the cases were patients with Class III malocclusion. Two cases, one with a Class II division 1 malocclusion and one with a Class I malocclusion, were used as distractors. Diagnosis of these cases was established by four published cephalometric analyses, which served as the ‘gold standard’, to determine the number of correct responses from the participants. Four faculty members were employed to confirm the cephalometric and clinical diagnosis of these cases with a full set of records. Participants were asked to diagnose the cases using only study casts and facial profile photographs for the first time. After an interval of 30 days, the procedure was repeated with the addition of lateral cephalograms and tracings. The accuracy in diagnosing malocclusion was determined by the percentage of correct responses. The level of confidence was determined by calculating the median of a 5‐point graded response utilizing the following confidence values: 1=not at all, 2=slightly, 3=moderately, 4=very, 5=absolutely. Differences between ‘with’ and ‘without’ lateral cephalograms were analyzed non‐parametrically using the Wilcoxon matched‐pairs signed‐ranks test. The results from both centers show the accuracy in dental classification of Class III malocclusion was quite good (83%±17.1% in the West Virginia group and 93%±14.1% in the Ohio group). The accuracy in skeletal classification was poor (72%±16.3 in the West Virginia group and 53%±7.03 in the Ohio group). The addition of lateral cephalograms and tracings did not improve the accuracy of dental or skeletal classification. However, clinicians felt more confident in their diagnoses with the information provided by lateral cephalograms and tracings. The consistency in dental and skeletal classification was fair and poor, respectively. These results suggest that clinicians are not consistent in diagnosing the Class III malocclusion and that skeletal classification of Class III malocclusion in children could be difficult. The addition of lateral cephalograms and tracings do not contribute to the accuracy of diagnosis.
Assessment of mesiodistal tooth angulation on the panoramic radiograph
Authors: Kim Dong Mok , Park Kyung Duk , Kwon Oh Won
Published: November 2003

Tilting of the head has been suggested as a potential source of error when the clinician assesses the angulation of teeth in the panoramic radiograph. If a reference line that could be stable in variations of head positioning during the radiographic exposure could be found, then the examination of the radiograph would be more accurate. We examined the effects of three different head positions on the panoramic image in ten volunteer patients. Our findings suggest that the upper and lower margins of the film are useful reference lines in estimating the mesiodistal angulation of six anteriors, and the mandibular plane is more useful in assessing the angulations of posterior teeth and canines.
Arcuate foramen: prevalence by age, gender, and degree of calcification
Authors: Cederberg Robert A. , Benson Byron W. , Nunn Martha , English Jeryl D.
Published: November 2003

The aim of the present study was to evaluate the prevalence of calcification of the oblique atlanto‐occipital ligaments (OAOLs, arcuate ligaments) relative to gender, age, and degree of calcification. Lateral cephalometric radiographs of 255 subjects presenting for orthodontic evaluation were reviewed. Population size was determined by power analysis. Two calibrated raters reviewed the films and classified the degree of calcification using a standardized rating scale. Class 1 ligaments demonstrated no calcification, Class 2 ligaments were less than half calcified, Class 3 ligaments were at least half calcified, and Class 4 ligaments were completely calcified. Of the subjects, 158 were Class 1 (62%), 70 were Class 2 (20%), 18 were Class 3 (7%), and 29 were Class 4 (11%). There was no evidence that the degree of ligamentous calcification of the arcuate ligaments differed by gender (p>0.10) or age
(p=0.8891). This suggests that the anomaly is congenital in origin.
Effects of environmental perturbations on abundance of subarctic plants after three, seven and ten years of treatments
Authors: Graglia Enrico , Jonasson Sven , Michelsen Anders , Schmidt Inger K. , Havström Mats , Gustavsson Lars
Published: November 2003

Analyses of changes in vegetation were carried out after three, seven and ten years of fertilizer addition, warming and light attenuation in two subarctic, alpine dwarf shrub heaths. One site was just above the tree line, at ca 450 m a.s.l., and the other at a much colder fell‐field at ca 1150 m altitude. The aim was to investigate how the treatments affected the abundance of different species and growth forms over time, including examinations of transient changes. Grasses, which increased in abundance by fertilizer addition, and cryptogams, which, by contrast, decreased by fertilizer addition and warming, were the most sensitive functional groups to the treatments at both sites. Nutrient addition exerted a stronger and more consistent effect than both shading and warming. Warming at the fell‐field had slightly greater effect than at the warmer tree line with an increase in deciduous shrubs. The decreased abundance of mosses and lichens to fertilizer addition and/or warming was most likely an indirect treatment effect, caused by competition through increased abundance and overgrowth of grasses. Such changes in species composition are likely to alter decomposition rates and the water and energy exchange at the soil surface. We observed few, if any, transient effects of declining responses during the 10 yr of treatments. Instead, there were many cumulative effects of the treatments for all functional groups and many interactions between time and treatment, suggesting that once a change in community composition is triggered, it will continue with unchanged or accelerated rate for a long period of time.
Effects of summer grazing by reindeer on composition of vegetation, productivity and nitrogen cycling
Authors: Olofsson Johan , Kitti Heidi , Rautiainen Pirjo , Stark Sari , Oksanen Lauri
Published: November 2003

In this study, we investigated the effect of reindeer grazing on tundra heath vegetation in northern Norway. Fences, erected 30 yr ago, allowed us to compare winter grazed, lightly summer grazed and heavily summer grazed vegetation at four different sites. At two sites, graminoids dominated the heavily grazed zone completely, while ericoid dwarf shrubs had almost disappeared. In the other two areas, the increase of graminoids was almost significant. At one of the sites where graminoids dominated the heavily grazed area, we also measured plant biomass, primary production and nitrogen cycling. In this site, heavy grazing increased primary production and rate of nitrogen cycling, while moderate grazing decreased primary production. These results were inconsistent with the view that the highest productivity is found at intermediate grazing pressure. These results rather support the hypothesis that intensive grazing can promote a transition of moss‐rich heath tundra into productive, graminoid‐dominated steppe‐like tundra vegetation. Moreover the results suggests that intermittent intensive reindeer grazing can enhance productivity of summer ranges.
Local recruitment of great and blue tits (Parus major, P. caeruleus) in relation to study plot size and degree of isolation
Authors: Matthysen Erik , Adriaensen Frank , Dhondt André A.
Published: November 2003

Few studies are available that analyse variation in dispersal rates between populations. Here we present data on the degree of local recruitment (LR) of great and blue tits (Parus major, P. caeruleus) in a large number of nest‐box plots in northern Belgium that vary in size, degree of isolation and population density. These plots have been studied for varying lengths of time over the past 40 yr. As expected, LR was higher among male than female birds, and this difference was most pronounced in blue tits. Regardless of species and sex, more local recruits were found in larger plots but also in plots with a higher population density. Thus, LR increased with population size (number of pairs) but levelled off in the largest populations at ca 50% for male birds. LR was higher in forest fragments compared to plots inside continuous forest, suggesting that fragmentation reduces exchange among local populations. However, LR was not related to the degree of isolation of individual fragments. We also found a weak but significant increase in LR with productivity (number of nestlings) of plots, but no relationship with other demographic variables.
Succession of bee communities on fallows
Authors: Steffan‐Dewenter Ingolf , Tscharntke Teja
Published: November 2003

Wild bee communities were studied on one‐ to five‐year‐old set‐aside fields with naturally developed vegetation (n=20), and old orchard meadows (n=4) to analyse effects of secondary succession on species diversity, resource use and associated life history traits. General theory predicts a steady increase of species richness with age of succession. In contrast, we found a first maximum in species richness of bees on two‐year‐old set‐aside fields and a second on old meadows. Successional changes of bee communities were related to changes of vegetation. The transition from pioneer successional stages, dominated by annuals, to early successional stages, dominated by perennials, resulted in the highest species richness of flowering plants in the second year within the first five years of succession. Species richness of flowering plants was the best predictor variable for species richness of bees, whereas the cover of flowering plants correlated with the abundance of bees. Annual plants were visited more often and perennials less often than expected from their flower cover. Halictidae tended to prefer flowers of annuals, whereas Megachilidae, Apidae and Anthophoridae significantly preferred perennials. In departure from successional theory, body size, proportion of specialised bees and proportion of parasitic bees did not significantly increase with successional age, but number of generations and the proportion of soil‐nesting bees decreased with successional age. Comparison of different management types showed that set‐aside fields with naturally developed vegetation supported much more specialised and endangered bee species than set‐aside fields sown with Phacelia tanacetifolia.
Predicting rat presence on small islands
Authors: Palmer Miquel , Pons Guillem X.
Published: November 2003

We analyzed data on presence or absence of 156 vascular plant species on 14 islets of the Cabrera National Park archipelago and found a significant correlation between rat presence and floristic composition. By contrast, island area, island height, and storm exposition seem to have no effect on species composition. We chose a subset of plants favoured or depressed by rat presence for a non‐linear principal component analysis and evaluated successfully the usefulness of such a subset in predicting rat presence using a randomization method. To optimally allocate resources, rat eradication campaigns should be focused in islets displaying rat‐free vegetation type.
Diet of raccoon dogs in summer in the Finnish archipelago
Authors: Kauhala Kaarina , Auniola Markus
Published: November 2003

The diet of raccoon dogs in summer was examined in the Finnish archipelago and compared with their diet on the mainland. Faeces were collected from latrines in the outer archipelago and the inhabited islands in May–July 1998 and 1999. Remains of waterfowl, especially those of female eider, occurred frequently in the faeces of raccoon dogs on the uninhabited islands, but less frequently on the inhabited islands and only occasionally on the mainland. Since many female eider died of disease during the summer in 1998 and 1999, and white‐tailed eagles are known to prey on brooding eider, it is probable that raccoon dogs did not themselves kill all the eider they consumed. Even if they did, they would only take a few percent of female eider population each year. It is thus improbable that raccoon dogs affect the size of the eider population in the Finnish archipelago. Frogs, reptiles, shrews and carrion occurred frequently in the diet on the mainland, but only occasionally in the outer archipelago. It is possible that raccoon dogs have decimated frog populations on small islands, as they are easy prey and occur frequently in the diet of raccoon dogs on the mainland. Small rodents are important prey for raccoon dogs on the mainland and on inhabited islands, but less important in the outer archipelago in early summer.
Feeding habits of the otter and the American mink in Białowieża Primeval Forest (Poland) compared to other Eurasian populations
Authors: Je˛drzejewska Bogumiła , Sidorovich Vadim E. , Pikulik Mikhail M. , Je˛drzejewski Włodzimierz
Published: November 2003

Diets of the otter Lutra lutra and the American mink Mustela vison were studied by scat analysis on five woodland rivers and streams in eastern Poland. Fish constituted 51% of food biomass consumed by otters in spring‐summer and 40% in autumn‐winter, with common fish (perch Perca fluviatilis, pike Esox lucius, and roach Rutilus rutilus) being captured most frequently by the otters. Amphibians (mainly Rana temporaria, which also dominated in the living community) made up 34% of otters’ food biomass in spring‐summer and 58% in autumn‐winter. American mink relied on three prey groups: fish (40% in spring‐summer, and 10% in autumn‐winter), frogs (32% and 51%, respectively), and small mammals (21% and 36%). Out of available Micromammalia, mink strongly selected the root vole Microtus oeconomus. The cold season diet of both otter and mink depended on river size. On small rivers with forested valleys, otters and mink fed nearly exclusively on amphibians (72–90% of food biomass). With size of a river increasing and riverside habitat becoming more open (sedge and reed marshes instead of forests), otters shifted to catching predominantly fish (up to 76% in diet) and mink to preying on small mammals (up to 65% in diet).  Review of literature on otter and mink in Eurasia showed that their diets did not change with latitude (as indicators of climate severity and duration of water freezing) but they depended on habitats. In otter diet, the mean share of fish declined from 94% (SE 1.7) on sea shores, to 71% (SE 2.9) on lakes and fish ponds, to 64% (SE 2.8) on rivers and streams. The roles of amphibians and crustaceans increased in the same gradient (from 0 to 15%, and from 3 to 7%, respectively). On inland waters, the abundance of crayfish was the essential factor differentiating otters’ diet composition. In Eurasia, the staple food types of American mink on rivers and streams were fish (on average, 27% in diet, SE 3.9), mammals (30%, SE 5.0), and amphibians (17%, SE 4.8), whereas on lakes and ponds mink fed predominantly on birds (on average, 33% in diet, SE 10.1) and fish (28%, SE 9.5). In the Palaearctic region, over a wide gradient of habitats, otters appeared strongly specialised on prey taken from water, whereas American mink was a typical generalist capable of utilising several prey groups originating from both water and land.
Community structure of ectomycorrhizal fungi across an alpine/subalpine ecotone
Authors: Kernaghan G. , Harper K. A.
Published: November 2003

In order to assess changes in the community structure of ectomycorrhizal fungi across the tree line, data on distributions of fungi and their host plants, as well as on edaphic factors and stand age, were collected at two montane sites in the Front Range of the Canadian Rockies. Canonical correspondence analysis (CCA) was used to explore relationships between fungal species composition and environmental factors. Richness and diversity of ectomycorrhizal fungi decreased with elevation, in spite of the fact that host plant diversity was highest at the ecotone between the subalpine forest and the alpine zone. Both host plant distribution and edaphic factors were important in explaining the observed changes in fungal species diversity and composition. The majority of ectomycorrhizal fungi found in the subalpine forest and at the ecotone were conifer associates, while a large proportion of those in the alpine zone were non‐host specific and able to form mycorrhizae with both angiosperms and gymnosperms. The abundance of non‐host specific fungi in the alpine zone is expected to provide a favorable environment for the establishment of conifer seedlings above the present tree line.
Farmland carabid beetle communities at multiple levels of spatial scale
Authors: Kinnunen Heidi , Tiainen Juha , Tukia Harri
Published: November 2003

Carabid beetle communities were studied at three levels of spatial scale, i.e. within fields (three sets of traps, mean distance 15 m), between fields (five fields within 1 km from each other) and between patches of farmland (four study areas 4–8 km from each other). We compared carabid assemblages sampled on five crop types in each study area, i.e. ley, set‐aside, spring cereal, potato, and sugar beet. Because of small sample sizes, only the community composition was studied within fields with a DCA ordination, but the differences were small. Analyses of species richness, activity density, community composition as revealed by DCA ordinations, dominance structure, diversity, and evenness showed that carabid communities varied significantly among patches of farmland but not between fields with different crops within the patches. Only the communities of potato fields were found to resemble each other. Only five carabid beetle species showed a preference for crops, and twelve species favoured some study areas. We conclude that the effect of spatial scale should be emphasised in further studies as it seems that carabid beetles may be very localised even in agricultural habitats.
Explaining the seasonal decline in litter size in European ground squirrels
Authors: Huber Susanne , Hoffmann Ilse E. , Millesi Eva , Dittami John , Arnold Walter
Published: November 2003

In European ground squirrels Spermophilus citellus as in many ground squirrel species, late born litters are composed of fewer young than early born litters. Two alternative though not mutually exclusive hypotheses may explain this seasonal pattern of change in litter size. On the one hand, the production of few large young late in the season may be an adaptation to time limitations on the offspring, that have to complete growth and fattening prior to hibernation. Then one would expect a trade‐off between offspring number and size as the breeding season progresses. At its extreme, this hypothesis would predict that total maternal effort should be equal independent of litter size. Alternatively, litter size may be determined by physiological limitations on the mother, in that highly constrained mothers breed later and produce smaller litters. Then one would expect reduced overall maternal effort in highly constrained mothers of smaller litters. In this case, a trade‐off between litter size and offspring size would not be expected. We found that total maternal effort in terms of gestation length and the duration of lactation increased with increasing litter size, thus supporting the second hypothesis. Lactation was not terminated at natal emergence. It extended a relatively long period of time beyond the time of first litter emergence depending on litter size. During prolonged lactation, individual young of large litters made up body mass to young of small litters. As a consequence, juvenile weaning body mass was unaffected by litter size although offspring body mass at natal emergence was inversely related to litter size. This additional weight gain in young of large litters compensated for initial survival disadvantages and presumably affected fecundity at yearling age.
Influence of land use history on seed banks in European temperate forest ecosystems: a review
Authors: Bossuyt Beatrijs , Hermy Martin
Published: November 2003

This study summarises European research on seed banks in temperate forest systems and analyses for differences in seed bank composition between geographically scattered forests with a different land use history. Special attention is given to seed bank characteristics of ancient forest species. Results of Detrended Correspondence Analysis suggest that historical land use is a key factor in determining the seed bank composition. Particularly seed banks of forests on former heathland sites differ from seed banks of ancient forest due to a high contribution of early successional species. The effect of former land use decreases after 50 yr, due to seed senescence. Total seed density decreases with recent forest age. Seed bank composition of eastern European forests is different from northern or western European forests, a difference which is mainly caused by species with a higher Ellenberg indicator value for continentality, temperature and reaction. In general, ancient forest species are poorly represented. Only a limited number is mentioned to have a persistent seed bank, and their densities are relatively low, which means that restoration of typical ancient forest vegetation can not rely on the seed bank. However, there is still a considerable lack of knowledge concerning seed bank and germination characteristics of forest species.
Body size determines the strength of the latitudinal diversity gradient
Authors: Hillebrand Helmut , Azovsky Andrey I.
Published: November 2003

In most groups of organisms, the species richness decreases from the tropics to the poles. The mechanisms causing this latitudinal diversity gradient are still controversial. We present data from a comprehensive weighted meta‐analysis on the strength of the latitudinal gradient in relation to body size. We sampled literature data on the correlation between species richness and latitude for a variety of organisms, ranging from trees to protozoa. In addition, own data on the presence of large‐scale diversity patterns for diatoms were included, both for local and regional species richness. The strength of the latitudinal gradient was positively correlated to the size of the organisms. Strongest decreases of species richness to the poles was found for large organisms like trees and vertebrates, whereas meiofauna, protozoa and diatoms showed weak or no correlations between species richness and latitude. These results imply that latitudinal gradients are shaped by non‐equilibrium (regional) processes and are persistent under conditions of dispersal limitation.
Topographic spatial characterisation of grey seal Halichoerus grypus breeding habitat at a sub‐seal size spatial grain
Authors: Twiss S. D. , Thomas C. J. , Pomeroy P. P.
Published: November 2003

Expansion within breeding colonies may critically depend upon the availability of suitable breeding habitat. Here we use topographic modelling in a GIS to characterise suitable pupping habitat and accurately predict the pattern of colonisation in an expanding grey seal breeding colony – the Isle of May (Scotland). We use high resolution images from large format aerial photographs of the colony to generate sub‐metre accurate Digital Terrain Models (DTMs). GIS modelling with these DTMs provides topographic measures of elevation, slope and ease of access to sea and freshwater pools at a 2 m grid cell size. Seal locations during the 1994 breeding season, with sex‐age class, were also digitised from the same images. We examine how the physical attributes of cells (locations) with and without pups differ and identify areas suitable for pupping but remaining unoccupied during 1994. We predict patterns of future colonisation by characterising areas differentiated by the densities of pups within 5 m grid cells and identifying areas, both occupied or unoccupied, with a potential for increased future pupping densities. Our predictions were tested by examining pup distributions observed in the 1998 breeding season. Occupied sites were significantly closer to freshwater pools and access to the sea (p<0.001) than unoccupied sites suggesting that proximity to water may restrict colony expansion before all areas of suitably flat terrain are occupied. All pup density classes occurred in sites with similar slope values and distance to pools. However, higher pupping densities occurred closer to access points (p=0.014). Pup densities observed in 1998 revealed that our 1994 predictions were accurate (p<0.0001). Only 12% of 466 grid cells had higher densities in 1998 than predicted, of which 88% differed by only 1 pup. These incorrectly classified cells occurred at the expanding edge of the colony (in a more topographically homogenous area) and at the main access points from the sea (major traffic zones). These results demonstrate the value of the accurate quantification of topographic parameters at the appropriate spatial grain (in this case below the size of the individual) for use in habitat classification and predictions of habitat utilisation.