bluuebunny/crossref_metadata_2025 huggingface dataset:
Dobutamine Stress Echocardiography Identifies Patients with Angina and Dynamic Left Ventricular Outflow Obstruction in Physiological Exercise
Authors: Cabrera‐Bueno Fernando J. , Gómez‐Doblas Juan J. , Garcia‐Pinilla Jose M. , Montiel‐Trujillo Angel , Jiménez‐Navarro Manuel , Martinez‐del‐Valle Dolores , Jiménez‐Hoyuela Jose M. , De Teresa‐Galván Eduardo
Published: February 2009

Background and Methods: To determine whether patients with no heart disease who develop dynamic left ventricular outflow obstruction (DLVOTO) during dobutamine echocardiography (DE) reproduce the phenomenon during exercise echocardiography (EE), DE and EE were performed in 78 patients (59 ± 9 years) with effort angina and no alterations in SPECT. Thirty‐eight (48.7%) patients had DLVOTO during DE and 15 (19.2%) during EE. This phenomenon during EE was reproducible in 39.4% of the patients with DLVOTO on DE, and 100% of the patients with DLVOTO during EE had it during DE. Independent factors predicting DLVOTO during EE were the LVOT diameter (OR 0.33 (0.14–0.74)) and the left ventricular (LV) mass index (OR 1.05 (1.01–1.08)). No cardiovascular events were noted after 26±3 months. The reproducibility of DLVOTO during EE in patients with unexplained angina and with DLVOTO on DE is associated with the size of the LVOT and the LV mass index. The long‐term prognosis is excellent.
The Value of 2D Strain Imaging during Stress Testing
Authors: Moonen Marie , Lancellotti Patrizio , Zacharakis Dimitrios , Pierard Luc
Published: February 2009

Stress echocardiography is increasingly used but its major limitation is the subjective interpretation of wall motion changes requiring experience. Speckle tracking enables simultaneous evaluation of radial, longitudinal, and circumferential myocardial deformation. Recently, two‐dimensional (2D) strain has been found to be as reliable as sonomicrometry for the assessment of left ventricular (LV) regional function. In the presence of inducible ischemia, longitudinal and circumferential abnormalities preceed the decrease in radial deformation. Optimal cutoffs have been obtained from 2D strain rate (SR) at peak dobutamine stress to predict coronary artery disease. However, 2D strain rate does not yet provide incremental accuracy to visual interpretation by experts. Speckle tracking strain could be useful to better identify contractile reverse and biphasic response of viable myocardium but there are not yet clinical studies published in this setting. Preliminary results suggest that 2D strain obtained during exercise could be useful in asymptomatic patients with severe aortic stenosis or organic mitral regurgitation (MR). In conclusion, the reliability and clinical importance of 2D strain during stress will be specified by further investigations.
Myocardial Metastasis in Patient with Cholangiocarcinoma
Authors: Chang Sung‐A , Kim Hyung‐Kwan , Oh Do‐Youn , Kim Yong‐Jin , Sohn Dae‐Won
Published: February 2009

Myocardium is a rare site for metastasis. We present here the case of myocardial metastasis from cholangiocarcinoma.
Continuing Medical Education Program in Echocardiography
Authors: Fan Pohoey , Diaz Tulio , Pencina Michael J. , Benjamin Emelia J. , Aragam Jayashri , Fuller Deborah L. , Pencina Karol M. , Levy Daniel , Vasan Ramachandran S.
Published: February 2009

Article Title: Prevalence, Clinical Correlates and Prognosis of Discrete Upper Septal Thickening on Echocardiography: The Framingham Heart Study
Influence of Nature of Filler on Densification of Anorthite‐Based Crystallizable Glass+Ceramic System for Low Temperature Cofired Ceramics Application
Authors: Kumar C. J. Dileep , Sowmya T. K. , Sunny E. K. , Raghu N. , Venkataramani N. , Kulkarni Ajit R.
Published: February 2009

This paper deals with the critical aspects of sintering of crystallizable glass+ceramic system, which is a critical part of low‐temperature‐cofired ceramics (LTCC) process. Densification studies clearly revealed the influence of filler's nature especially at lower glass contents (≤70 vol%) and lower sintering temperatures. In this temperature range, marked improvement in density was observed in the order cordierite>fused silica>mullite>alumina. The decisive role played by wetting of glass on filler has been demonstrated using heating microscopy and wetting studies. However, densification was not influenced by the nature of filler at higher glass contents (>70 vol%) and at higher sintering temperatures. This is because in this range of glass content viscous flow of glass dominates the wetting behavior. This paper brings out the salient features responsible for the sintering behavior of anorthite glass+ceramic LTCC composition.
Backscatter Electron Imaging and Electron Backscatter Diffraction Characterization of LaCoO3 During In Situ Compression
Authors: Karlsen Morten , Einarsrud Mari‐Ann , Lein Hilde L. , Grande Tor , Hjelen J. , Vullum Per Erik
Published: February 2009

Ferroelastic domain reorientation in polycrystalline rhombohedral LaCoO3 has been demonstrated by backscatter electron (BSE) imaging and electron backscatter diffraction (EBSD) combined with in situ compression testing. Four different domain orientations were confirmed in line with expectation from crystallography. During in situ compression reorientation of domains were observed favoring domains with the c‐axis close to perpendicular to the stress field. In situ compression combined with BSE/EBSD is shown to be an excellent tool for studying the influence of mechanical stress on grain/domain structure in polycrystalline ceramics.
Toluene‐Impaired Drivers: Behavioral Observations, Impairment Assessment, and Toxicological Findings
Authors: Capron Brian , Logan Barry K.
Published: February 2009

Abstract:  Toluene is an aromatic hydrocarbon solvent frequently abused for its euphoric and intoxicating properties. This report describes a series of six cases involving drivers arrested for driving under the influence who subsequently tested positive for toluene. Case data including driving behavior, physiological signs and symptoms, evidence of impairment, and toxicology findings were reviewed. Blood toluene concentrations in the drivers ranged from 12 to 45 mg/L (median 23 mg/L, mean 25 mg/L, SD 12.1 mg/L). All drivers were determined to be intoxicated, and displayed symptoms including balance problems, confusion and disorientation, loss of coordination, and inability to follow instructions. They also displayed horizontal but not vertical nystagmus, elevated pulse and blood pressure, and lower body temperature. These findings are consistent with prior reports that subjects with blood toluene concentrations above 10 mg/L are invariably under the influence and their driving skills are affected.
Group IIA phospholipase A2 as a prognostic marker in prostate cancer: relevance to clinicopathological variables and disease‐specific mortality
Authors: MIRTTI TUOMAS , LAINE VELI JUKKA O. , HIEKKANEN HEIKKI , HURME SAIJA , ROWE OUTI , NEVALAINEN TIMO J. , KALLAJOKI MARKKU , ALANEN KALLE
Published: February 2009

Group IIA Phospholipase A2 (PLA2‐IIA), a key enzyme in arachidonic acid and eicosanoid metabolism, participates in a variety of inflammatory processes but possibly also plays a role in tumor progression in vivo. Our aim was to determine the mRNA and protein expression of PLA2‐IIA during prostate cancer progression in localized and metastatic prostate tumors. We evaluated the prognostic significance of PLA2‐IIA expression in biochemical recurrence, clinical recurrence and disease‐specific survival after surgical treatment. The expression of PLA2‐IIA was examined by immunohistochemistry and chromogenic in situ hybridization in tissue microarrays of radical prostatectomy specimens and advanced/metastatic carcinomas. The expression data were analyzed in conjunction with clinical follow‐up information and clinicopathological variables. The mRNA and protein expression of PLA2‐IIA was significantly increased in Gleason pattern grade 2–4 carcinomas compared with benign prostate (p‐values 0.042–0.001). In metastases, the expression was significantly lower than in local cancers (p=0.001). The PLA2‐IIA expression correlated positively with Ki‐67 and α‐methylacyl CoA racemase (AMACR) expression. The prognostic evaluation revealed decreased PLA2‐IIA protein expression among patients who had died of prostate cancer. In conclusion, PLA2‐IIA expression is increased in carcinoma when compared with benign prostate. However, metastatic carcinoma showed decreased expression of PLA2‐IIA when compared with primary carcinomas. PLA2‐IIA may serve as a marker for highly proliferating, possibly poorly differentiated prostate carcinomas. The protein expression of PLA2‐IIA may be diminished in patients who consequently die of prostate cancer.
Overexpression of cyclooxygenase‐2 in urothelial carcinoma in conjunction with tumor‐associated‐macrophage infiltration, hypoxia‐inducible factor‐1α expression, and tumor angiogenesis
Authors: CHEN WAN‐TZU , HUNG WEN‐CHUN , KANG WAN‐YI , HUANG YA‐CHUN , SU YUE‐CHIU , YANG CHING‐HSIU , CHAI CHEE‐YIN
Published: February 2009

This study examines whether the expression of cyclooxgenase‐2 (COX‐2) in urothelial carcinoma (UC) is associated with macrophage infiltration, hypoxia‐inducible factor‐1α (HIF‐1α) expression and angiogenesis. We investigated the expression of COX‐2 associated with HIF‐1α and performed double immunohistochemical analysis of 216 UCs for COX‐2 expression and the correlation with tumor‐associated‐macrophage (TAM) density and microvessel density (MVD) in situ. A high expression of COX‐2 was positively correlated with tumor invasiveness, histologic grade and HIF‐1α expression in UC (p<0.0001, p=0.003, p<0.0001, respectively). Quantification of double staining of COX‐2/CD34 and COX‐2/CD68 showed that a higher MVD and TAM density was found in COX‐2 high‐expression than in COX‐2 low‐expression tumor fields (p<0.0001). Adjacent to the principal of COX‐2 expression areas, MVD value and TAM density were significantly increased in HIF‐1α high‐expression specimens compared with HIF‐1α low‐expression ones (p<0.0001). Interestingly, our data revealed that high COX‐2 expression (p=0.002), high HIF‐1α expression (p<0.0001) and TAM density (p<0.0001) were all associated with high MVD value. Our results suggest that COX‐2 may produce a cooperative effect in promoting tumor progression and may be involved in the process of angiogenesis through increasing TAM infiltration or HIF‐1α regulation by hypoxia.
Increased p53 immunoreactivity in proliferative inflammatory atrophy of prostate is related to focal acute inflammation
Authors: WANG WANZHONG , BERGH ANDERS , DAMBER JAN‐ERIK
Published: February 2009

Proliferative inflammatory atrophy (PIA) of prostate has been proposed as a precursor lesion of prostate cancer. The aim of the current study was to evaluate the expression of p53 protein in PIA lesions and to investigate the relationship between p53 staining and Ki‐67, glutathione S‐transferase‐π (GSTP1) and cyclooxygenase‐2 (COX‐2) immunohistochemical expression. The results revealed that p53 nuclear immunostaining appeared in PIA lesions in 2.1±3.4% (mean±SD) of the basal and 0.9±2.3% of the luminal epithelial cells. Both these values were significantly higher than those in normal‐appearing acini (p<0.0001). Increased p53 expression in luminal cells was related to focal infiltration of polymorphonuclear leucocytes. A positive correlation between p53 expression and Ki‐67 was found in COX‐2‐positive PIA lesions (r=0.610, p<0.0001). Half of the p53‐positive epithelial cells expressed diffuse GSTP1 immunostaining in the same lesions. The present study demonstrates an increased p53 expression in PIA lesions, and inflammation, especially acute inflammation, may play a role in the induction of p53 over‐expression, particularly as cells in PIA lesions are known to have a reduced defence against DNA damage.
Increased lymphatic vascular density is seen before colorectal cancers reach stage II and growth factor FGF‐2 is downregulated in tumor tissue compared with normal mucosa
Authors: SUNDLISÆTER EIRIK , RØSLAND GRO VATNE , HERTEL JENS KRISTOFFER , SAKARIASSEN PER ØYSTEIN , ALMÅS BJARTE , DICKO ALY , SØNDENAA KARL
Published: February 2009

Lymphangiogenesis is an important event in progression of colorectal cancer (CRC), and the estimated lymphatic vascular density (LVD) probably indicates facilitated lymphatic tumor cell invasion and metastasis. However, at what time point during tumor progression this process is triggered, is unclear. The aim of this study was twofold. Firstly, to examine LVD in paired samples of CRC tissue and normal mucosa with specific emphasis on possible difference in LVD between tumors stages II and III, and secondly, the expression of the lymphangiogenic growth factor fibroblast growth factor‐2 (FGF‐2). Eighteen patients were studied. Immunostaining for podoplanin was performed to highlight lymphatic vessels. FGF‐2 mRNA expression was determined by quantitative real‐time RT‐PCR, whereas protein expression was quantitatively assessed by densitometric analysis of Western blot signal intensity. The immunoblots were further validated by FGF‐2 immunostaining of histological sections. LVD was significantly increased in tumor tissue compared with the normal mucosa but no changes in LVD between stages II and III CRC was observed. FGF‐2 was found to be downregulated both at the mRNA and protein level in tumor tissues compared with normal mucosa. Lymphangiogenesis was triggered early in tumor development. An increased LVD was established before the tumor reached stage II. FGF‐2 was downregulated in tumor tissue. The importance of this finding remains unclear.
Environmental and genetic variation in body condition and blood profile of great tit Parus major nestlings
Authors: Cláudia Norte Ana , Sheldon Ben C. , Sousa José P. , Ramos Jaime A.
Published: February 2009

Health state parameters in natural populations can be used as bioindicators of environmental health if they respond to environmental cues. We studied to which extent health state parameters (morphological, biochemical, and haematological) were determined by the environment in which nestling birds were reared or by their genotype, using a cross‐fostering experiment in great tits Parus major. Morphological parameters and plasma protein, had a higher environmental than genetic component of variance which could be related with food availability differing between rearing nests. Glutathione peroxidase, an enzyme involved in antioxidant protection, also had a relatively high environmental component of variance, suggesting that nestlings in different rearing nests were exposed to different degrees of oxidative stress. Plasma cholinesterases were more influenced by the birds’ genotype than by the rearing environment. The parameters with the lowest residual variance and the highest environmental component of variance such as glutathione peroxidase, plasma protein and morphological parameters (tarsus length and weight) would be more adequate as bioindicators.
Habitat quality, nestling diet, and provisioning behaviour in great tits Parus major
Authors: Wilkin Teddy A. , King Lucy E. , Sheldon Ben C.
Published: February 2009

Variation in early nutrition is often a strong predictor of offspring condition and fitness. In the case of woodland passerine birds, nestling diet is determined by the spatiotemporal distribution of prey items such as caterpillars during the nestling period, and is usually quantified as differences in provisioning behaviour between habitats. However, the habitat level does not account for variation between individual territories, the level at which competition and selection are assumed to operate. Here we use nestbox cameras and Radio Frequency Identification technology (RFID) to simultaneously assess variation in both nestling diet (components) and provisioning rates (quantity) among a sample (n=22) of different quality great tit Parus major territories selected from a larger breeding population (n=310 fledged broods) in a single year. Caterpillars were by far the most numerous item provisioned to nestlings (mean=75% of prey items), as expected given the known importance of this food source for this species. Broods raised close to an oak tree, or far from the woodland edge, were provisioned the highest proportion of caterpillars. Provisioning rates declined seasonally and there was a weak association between low provisioning rates and caterpillar rich diets. During the first week of the nestling stage, nestling condition was unrelated to the proportion of caterpillars in the diet, provisioning rates and oak proximity. Condition at fledging was slightly improved in broods fed a higher proportion of caterpillars in the diet and in broods raised close to an oak tree. However, in our data early breeding was the only predictor of recruitment success, although power was low for this test. Analyses of long‐term data (41 years) from the same population confirmed a relationship between oak proximity and fledgling mass, but not recruitment success. Our results suggest that territory level environmental variation can affect offspring condition, probably through observed changes in nestling diet, but that such variation does not necessarily produce discernable effects on offspring fitness.
Human alveolar bone cell proliferation, expression of osteoblastic phenotype, and matrix mineralization on porous titanium produced by powder metallurgy
Authors: Rosa Adalberto Luiz , Crippa Grasiele Edilaine , De Oliveira Paulo Tambasco , Taba Jr Mario , Lefebvre Louis‐Philippe , Beloti Marcio Mateus
Published: February 2009

Objective: This study aimed at investigating the influence of the porous titanium (Ti) structure on the osteogenic cell behaviour.

Materials and methods: Porous Ti discs were fabricated by the powder metallurgy process with the pore size typically between 50 and 400 μm and a porosity of 60%. Osteogenic cells obtained from human alveolar bone were cultured until subconfluence and subcultured on dense Ti (control) and porous Ti for periods of up to 17 days.

Results: Cultures grown on porous Ti exhibited increased cell proliferation and total protein content, and lower levels of alkaline phosphatase (ALP) activity than on dense Ti. In general, gene expression of osteoblastic markers–runt‐related transcription factor 2, collagen type I, alkaline phosphatase, bone morphogenetic protein‐7, and osteocalcin was lower at day 7 and higher at day 17 in cultures grown on porous Ti compared with dense Ti, a finding consistent with the enhanced growth rate for such cultures. The amount of mineralized matrix was greater on porous Ti compared with the dense one.

Conclusion: These results indicate that the porous Ti is an appropriate substrate for osteogenic cell adhesion, proliferation, and production of a mineralized matrix. Because of the three‐dimensional environment it provides, porous Ti should be considered an advantageous substrate for promoting desirable implant surface–bone interactions.
Black stain and dental caries in Filipino schoolchildren
Authors: Heinrich‐Weltzien Roswitha , Monse Bella , Van Palenstein Helderman Wim
Published: February 2009

Abstract –  Black stain is defined as dark pigmented exogenous substance in lines or dots parallel to the gingival margin and firmly adherent to the enamel at the cervical third of the tooth crowns in the primary and permanent dentition.

Objectives:  This study was conducted to assess the prevalence of black stain on teeth of Filipino children and to determine a possible association between black stain and caries levels. The study was designed to test the following hypotheses: (i) the prevalence of black stain does not differ between children from schools with oral health intervention programs and those from schools without an intervention program, (ii) the prevalence of black stain does not differ in children attending easily accessible and remote schools, (iii) caries prevalence and caries experience do not differ in children with and without black stain and (iv) the caries distribution at the surface level does not differ in children with and without black stain.

Methods:  In total, 32 elementary schools were included. 19 schools with a comprehensive school‐based preventive oral health program, seven schools with a basic preventive program and six control schools. All sixth graders of these schools (n = 1748) aged 11.7 ± 1.1 years were clinically examined for black stain. DMFT was assessed in 1121 children by seven calibrated dentists using WHO criteria. DMFS was scored in 627 children by two calibrated dentists.

Results:  Black stain was found in 16% of this population. The prevalence of black stain did not differ significantly between children attending schools with different oral health intervention programs. Thus, hypothesis 1 was accepted. The prevalence of black stain was significantly higher (P < 0.05) in remote than in more accessible schools. Thus, hypothesis 2 was rejected. Children with black stain had significantly lower (P < 0.05) caries prevalence and caries experience than children without black stain. Thus, hypothesis 3 was rejected. No difference was found in the DMFS pattern of occlusal, smooth and proximal surfaces between children with and without black stain. Thus hypothesis 4 was accepted.

Conclusions:  The presence of black stain is associated with lower levels of caries, but a difference in the distribution of caries in black stain children was not noticed. The interplay between black stain, caries, oral microflora and diet remains unclear and urges further research.
On the Reliability of Quantitative Volumetric and Structural Neuroimaging
Authors: Klein J. , Laun F. , Erhard P. , Diehl V. , Hahn H. K.
Published: February 2009

Quantitative neuroimaging techniques have become emerging technologies within clinical practice. In this paper, we survey a few clinical applications where quantification methods have received increasing attention, namely in the area of brain atrophy, lesion load computation and quantification of diffusion processes. We focus on the reliability and reproducibility of such methods and will use the example of quantitative diffusion tensor imaging to discuss methodological details. There, we show possible avenues for evaluating correctness and reliability. On the one hand, we show results from our novel hardware phantom experiments, where axonal fibres are emulated by synthetic industry fibres. On the other hand, we present a new framework for constructing software phantoms which can be used to evaluate, for example, the impact of partial volume effects in case of axonal loss as to be found in multiple sclerosis. Advantages and disadvantages as well as pitfalls of quantification and evaluation techniques are illustrated throughout the paper.
Computer‐Aided Diagnosis in Thoracic Computed Tomography
Authors: Van Ginneken B.
Published: February 2009

Current computed tomography (CT) technology allows for isotropic, sub‐millimetre resolution acquisition of the thorax in a few seconds. These thin‐slice chest scans have become indispensable in thoracic radiology, but have also increased the time and effort required from radiologists for reporting. Industry has focused on the development of computer‐aided diagnosis (CAD) tools to facilitate the interpretation of thoracic CT data. In this paper I discuss the three most ‘senior’ CAD applications for chest CT: nodule detection, nodule volumetry and quantification of emphysema. Are these applications ready for widespread application?
Computer‐Aided Detection in Mammography
Authors: Karssemeijer N.
Published: February 2009

In breast cancer imaging many innovations continue to take place. This article discusses computer‐aided detection (CAD) of breast cancer in mammograms, which is the first large‐scale application of independent computerized interpretation of radiological images. Thousands of systems have already been installed worldwide and use of CAD is rapidly expanding with the introduction of digital mammography. Radiologists are generally pleased with the new technology, in particular for its ability to mark clustered microcalcifications with high sensitivity. However, most believe that the performance of CAD for mass detection should still be improved to make it more useful. Most clinical studies indicate that CAD is effective in practice, both for detection of masses and microcalcifications. Future developments show a trend towards using CAD not only for detection but also for characterization of lesions.
Spontaneous and initiated succession on unvegetated slopes in the abandoned lignite‐mining area of Goitsche, Germany
Authors: Kirmer Anita , Mahn Ernst‐Gerhard
Published: February 2009

Abstract. In this study, we examined the colonization of unvegetated, dry slopes in the lignite‐mining area of Goitsche, Germany. The plots, characterized by different habitat conditions, were studied from 1994–2000.

The vegetation development on treated plots was compared to untreated plots showing spontaneous succession. For initial treatments we used fresh plant clippings from a species‐rich sandy grassland (Armerion elongatae) mowed at the end of July. Soil seed bank samples, taken at the beginning of the experiments and cultivated for 18 months, confirmed that the vegetation development on the slopes started with primary succession. Because seed rain is considered to be an important factor in primary succession, we also studied the diaspore input during the first year. The hospitable Quaternary substrate of Site I (pH = 4.1–4.7, 92 % sand) supports fast vegetation development on treated and untreated plots. On treated plots, we have identified plant assemblages similar to initial stages of the Armerion elongatae community. On control plots, Coryne‐phorion communities have established spontaneously. At Site II (mixed Quaternary and Tertiary substrate, pH = 3.0–3.5,40 % sand) the total cover and number of psammophytic species was low. Treated plots showed development towards ruderal sandy grassland, but the establishment of Calamagrostis epigejos would eventually lead to monodominant stands. Untreated control plots showed basically the same pattern, however the development was slower. At Site III (pH = 1.8–2.8, 34 % sand), the hostile Tertiary substrate impeded the succession on both treated and untreated plots because low pH and therefore high amounts of Al3+ produced elemental toxicity to plants. The application of plant clippings accelerated the vegetation development in sites with a pH exceeding 3.

On plots with the initial treatment, vegetation cover and total number of species were higher than on untreated plots. The application of fresh plant clippings from areas with similar habitat conditions appears to be a viable alternative to traditional restoration methods.
Effects of reclamation measures on plant colonization on lignite waste in the eastern Pyrenees, Spain
Authors: Ninot J.M. , Herrero P. , Ferré A. , Guàrdia R.
Published: February 2009

Abstract. This paper deals with vegetation establishment on waste dumps in the montane and submontane belts of the eastern Pyrenees, where submediterranean Quercus humilis forests, Pinus sylvestris forests and mesoxerophilous pastures make up most of the landscape; these are considered as target communities for reclamation. The waste consists of marl and lime regolith, very poor in nutrients and structure (Poch et al. 1989). The dumps were terraced in 1985–1986; some were left for spontaneous re‐colonization and others were reclaimed in various ways. In 1992 we took 36 vegetation samples on the dumps, based on the point quadrat procedure, to evaluate the colonization status and the differences between reclamation techniques. The samples were analysed on the basis of their species composition (ecological groups and multivariate analysis) and structural aspects (coverage, diversity, etc.). Reclamation treatment results varied widely, most of the dumps showing a low degree of naturalness. Colonizing vegetation ranged from a mixture of opportunist and stress‐resistant taxa, forming poorly covered surfaces on the dumps where colonization has been poor, to dense grasslands dominated by one (or a few) introduced competitive grass species, where reclamation procedures had been intensive. Sowing treatments, where pasture species were sown onto dumps, produced intermediate results, as resulting vegetation cover was similar to control plots and naturalness was low, but in a few cases they yielded more interesting swards, fairly dense and diverse, and including high numbers of spontaneous species. Choice of sown species and proximity to undisturbed vegetation accelerate succession.
Restoration success of low‐production plant communities on former agricultural soils after top‐soil removal
Authors: Verhagen R. , Klooker J. , Bakker J.P. , van Diggelen R.
Published: February 2009

Abstract. The success inrestoring seven low‐production vegetation types on former agricultural soil after top‐soil removal was investigated. The colonization and establishment of target species in permanent plots was recorded during the first nine years after restoration measures were taken. For each permanent plot abiotic site conditions were used to determine which of the vegetation types could persist there. A comparison of the actual vegetation in the permanent plots with reference releves of the selected vegetation type revealed a gradually increasing similarity during consecutive years for five vegetation types. This was due to the occurrence of an increasing number of target species and the number of permanent plots they occurred in. However, nine years after top‐soil removal a large number of the target species were still lacking from the vegetation in the permanent plots, although most were present in the local species pool. Seed dispersal therefore seems to be a major limiting factor for restoration of these low‐production vegetation types on formerly agricultural soils.
Species richness and species turnover in a successional heathland
Authors: Chytrý Milan , Sedláková Iva , Tichý Lubomír
Published: February 2009

Abstract. Changes in species richness and species turnover during secondary succession following experimental disturbance were studied in eight permanent plots in a species‐rich dry heathland in the southern part of the Czech Republic. The treatments applied were sod‐cutting, burning, cutting of above‐ground biomass, and control. The plots were sampled annually between 1992 and 2000; species richness was analysed at three scales, 25 cm × 25 cm, 1 m × 1 m, and 3 m × 3 m.

Disturbances resulted in increased species richness. The highest vascular plant richness was attained during the secondary succession after sod‐cutting, where species established on exposed bare ground. Less severe disturbances by burning and cutting also caused a slight increase in the number of vascular plant species. For bryophytes and lichens, the highest increase in the number of species was also found in the sod‐cut plots, where all cryptogams were removed by the disturbance. At the scale of 3 m × 3 m, species richness of both vascular plants and cryptogams peaked in 1995–1996, i.e. 3–4 yrs after the disturbance, and slowly decreased or slightly fluctuated without any trend thereafter. At smaller scales it either peaked later or constantly increased over the entire observation period of 9 yrs. Species mobility, expressed as species accumulation over time, was lower than reported from grasslands. Rates of species turnover, calculated as Jaccard dissimilarity between pairs of consecutive years, corresponded across different scales. This implies that successional dry heathlands have a higher small‐scale mobility than heathlands which are apparently stable at larger scale.
Herbaceous vegetation change in variable rangeland environments: The relative contribution of grazing and climatic variability
Authors: Fuhlendorf Samuel D. , Briske David D. , Smeins Fred E.
Published: February 2009

Abstract. A 44‐yr record of herbaceous vegetation change was analysed for three contrasting grazing regimes within a semi‐arid savanna to evaluate the relative contribution of confined livestock grazing and climatic variability as agents of vegetation change. Grazing intensity had a significant, directional effect on the relative composition of short‐ and mid‐grass response groups; their composition was significantly correlated with time since the grazing regimes were established. Interannual precipitation was not significantly correlated with response group composition. However, interannual precipitation was significantly correlated with total plant basal area while time since imposition of grazing regimes was not, but both interannual precipitation and time since the grazing regimes were established were significantly correlated with total plant density. Vegetation change was reversible even though the herbaceous community had been maintained in an altered state for ca. 60 yr by intensive livestock grazing. However, ca. 25 yr were required for the mid‐grass response group to recover following the elimination of grazing and recovery occurred intermittently. The increase in mid‐grass composition was associated with a significant decrease in total plant density and an increase in mean individual plant basal area. Therefore, we failed to reject the hypotheses based on the proportional change in relative response group composition with grazing intensity and the distinct effects of grazing and climatic variability on response group composition, total basal area and plant density. Long‐term vegetation change indicates that grazing intensity established the long‐term directional change in response group composition, but that episodic climate events defined the short‐term rate and trajectory of this change and determines the upper limit on total basal area. The occurrence of both directional and non‐directional vegetation responses were largely a function of (1) the unique responses of the various community attributes monitored and (2) the distinct temporal responses of these community attributes to grazing and climatic variation. This interpretation supports previous conclusions that individual ecosystems may exist in equilibrial and non‐equilibrial states at various temporal and spatial scales.
Modeling landscape patterns of understory tree regeneration in the Pacific Northwest, USA
Authors: Wimberly Michael C. , Spies Thomas A.
Published: February 2009

Abstract. Vegetation maps serve as the basis for spatial analysis of forest ecosystems and provide initial information for simulations of forest landscape change. Because of the limitations of current remote sensing technology, it is not possible to directly measure forest understory attributes across large spatial extents. Instead we used a predictive vegetation mapping approach to model Tsuga heterophylla and Picea sitchensis seedling patterns in a 3900‐ha landscape in the Oregon Coast Range, USA, as a function of Landsat TM imagery, aerial photographs, digital elevation models, and stream maps. Because the models explained only moderate amounts of variability (R2 values of 0.24–0.56), we interpreted the predicted patterns as qualitative spatial trends rather than precise maps.

P. sitchensis seedling patterns were tightly linked to the riparian network, with highest densities in coastal riparian areas. T. heterophylla seedlings exhibited complex patterns related to topography and overstory forest cover, and were also spatially clustered around patches of old‐growth forest. We hypothesize that the old growth served as refugia for this fire‐sensitive species following wildfires in the late 19th and early 20th centuries. Low levels of T. heterophylla regeneration in hardwood‐dominated forests suggest that these patches may succeed to shrublands rather than to conifer forest.

Predictive models of seedling patterns could be developed for other landscapes where georeferenced inventory plots, remote sensing data, digital elevation models, and climate maps are available.
Foraging geese, vegetation loss and soil degradation in an Arctic salt marsh
Authors: Jefferies Robert L. , Rockwell Robert F.
Published: February 2009

Abstract.The North American mid‐continent population of Lesser snow geese (Chen caerulescens caerulescensL.) has increased by ca. 7% per year, largely as a result of geese feeding on agricultural crops in winter and on migration. We describe the long‐term effects of increasing numbers of geese at an arctic breeding ground (La Pérouse Bay, Manitoba) on intertidal salt‐marsh vegetation. Between 1985 and 1999 goose grubbing caused considerable loss of graminoid vegetation along transects in intertidal marshes. Loss of vegetation led to bare sediment with a plant cover of less than 2%. Changes in vegetation could not be described by simple linear, geometric or exponential functions; most losses occurred between 1988 and 1990 and losses were staggered in time between individual transects, some of which had all vegetation removed.

Between 1979 and 1999 the standing crop in July in remaining intact heavily‐grazed swards ofPuccinellia phry‐ganodesandCarex subspathaceafell from 40–60 g m‐2to 20–30 g m‐2. Intense grazing on remaining patches of sward has restricted growth of these clonal forage plants and hypersalinity of bare sediments has precluded re‐establishment of vegetation. Between 1989 and 1993 numbers of faecal droppings in grazed plots reached maximum values of 15–22 droppings m‐2wk‐1. Since then peak values have remained at less than 13 droppings m‐2wk‐1. The loss of vegetation and changes in soil conditions have resulted in the establishment of an alternative stable state (hypersaline bare sediment).
Long‐term vegetation changes in experimentally grazed and ungrazed back‐barrier marshes in the Wadden Sea
Authors: Bos Daan , Bakker Jan P. , de Vries Yzaak , van Lieshout Suzan
Published: February 2009

Abstract. Vegetation succession in three back‐barrier salt marshes in the Wadden Sea was studied using a data set comprising 25 years of vegetation development recorded at permanent quadrats. The effect of livestock grazing on succession was assessed by comparing quadrats where grazing was experimentally prevented or imposed. We studied changes at the species level as well as at the level of the plant community. Special attention is given to effects on plant species richness and community characteristics that are relevant for lagomorphs (hares and rabbits) and geese. Inundation frequency and grazing were most important in explaining the variation in species abundance data. The three marshes studied overlap in the occurrence of different plant communities and the observed patterns were consistent between them. Clear differences in frequency and abundance of plant species were observed related to grazing. Most plant species had a greater incidence in grazed treatments. Species richness increased with elevation, and was 1.5 to 2 × higher in the grazed salt marsh. Grazing negatively influenced Atriplex portulacoides and Elymus athericus, whereas Puccinellia maritima and Festuca rubra showed a positive response. The communities dominated by Elymus athericus, Artemisia maritima and Atriplex portulacoides were restricted to the ungrazed marsh. Communities dominated by Puccinellia maritima, Juncus gerardi and Festuca rubra predominantly occurred at grazed sites. As small vertebrate herbivores prefer these plants and communities for foraging, livestock grazing thus facilitates for them.
Early changes in species composition of upland sown grassland under extensive grazing management
Authors: Marriott Carol A. , Bolton G.R. , Barthram G.T. , Fisher J.M. , Hood K.
Published: February 2009

Abstract. Due to economic pressures and policy changes Lolium perenne‐Trifolium repens sown swards in upland UK sheep systems are likely to become less intensively managed. We present results from the first 5 yr of a long‐term experiment studying vegetation change under more extensive grazing management at three sites. One treatment was representative of current, intensive management and 5 were unfertilized with different intensities of seasonal grazing. The species composition of unfertilized, ungrazed swards changed dramatically within 2 yr and the sown species had virtually disappeared by year 5. Ranunculus repens, Poa trivialis, Agrostis gigantea, Juncus spp. and Carex spp. became dominant at the wettest site. Grasses were dominant at the other sites. In contrast, the sown species were retained in the unfertilized, grazed treatments; there were small shifts in abundance of the species present initially and few additions or losses of species. Some colonizing species were present in the seed bank whereas others with a transient seed bank appeared to have invaded from neighbouring vegetation. Implications of these results for compensation schemes to reduce animal output and increase biodiversity are discussed.
70 years of permanent plot research in The Netherlands
Authors: Smits N.A.C. , Schaminée J.H.J. , van Duuren L.
Published: February 2009

Abstract. Within the framework of the Dutch ‘Network Ecological Monitoring’, a large set of new permanent plots has been established to monitor selected plant communities throughout The Netherlands for studying the effects of environmental changes on species composition of semi‐natural communities. This national programme will also make use of pre‐existing permanent plots. These plots reflect the long and comprehensive history of research using permanent plots in The Netherlands, where the first permanent plots were established in the early 1930s. To enhance the usefulness of preexisting permanent plots, a comprehensive permanent plot database was compiled. This database was derived from the Dutch National Vegetation Database, that was established for the recent vegetation classification of The Netherlands. This was supplemented with information from various organizations and a number of individual researchers. Currently, the permanent plot database contains ca. 6000 permanent plots. More than 2500 of these plots have been sampled at least 5, and ca. 1500 plots at least 10. Most of the plots are from grasslands, followed by forests and dune systems.

This database not only provides insight into vegetation succession, fluctuations within plant communities over time, and the effects of changes of the environment on the vegetation but, indirectly, italso offers the possibility of studying the long‐term behaviour of individual plant species (e.g. establishment, competition, longevity). For the Network Ecological Monitoring a selection of these (historical) plots will be added to the new network of permanent plots in The Netherlands, thus supplying information of past vegetation conditions.
Restoring riparian meadows currently dominated by Artemisa using alternative state concepts ‐ above‐ground vegetation response
Authors: Wright J. Michael , Chambers Jeanne C.
Published: February 2009

Abstract. Livestock overgrazing and stream incision in the western USA often result in encroachment and dominance of Artemisia tridentata ssp. tridentata (Big sagebrush) in riparian areas that formerly supported meadows. To define the alternative states and thresholds for these ecosystems, we conducted a restoration experiment that included sites with high, intermediate or low water tables. We used a paired‐plot approach in which one plot on each site was burned and seeded with native grasses and forbs typical of naturally occurring dry meadow and Artemisia/Leymus cinereus ecological types, while adjacent unburned plots served as controls. Sites with high and intermediate water tables had greater initial abundances of perennial grasses typical of dry meadows, such as Leymus triticoides and Poa secunda ssp. juncifolia, and these species increased after the burn. In contrast, sites with low water tables were dominated by annual forbs such as Chenopo‐dium album and Descurainia pinnata after the burn. Biomass increased progressively from 1997 to 1999 on burned plots, while controls showed little change. Burning effects were microsite specific, with former Artemisia microsites exhibiting lower biomass than interspaces initially, but similar or higher biomass by the third year. Establishment of seeded species was low and species composition was determined largely by pre‐burn vegetation. Artemisia dominated sites with high water tables appear to represent an alternative state of the dry meadow ecological type, while sites with low water table sites have crossed an abiotic threshold governed by water tables and represent a new ecological type. Burning is an effective tool for restoring relatively high water table sites, but low water table sites will require burning and seeding with species adapted to more xeric conditions.
Restoration of species‐rich flood‐plain meadows from abandoned arable fields in NE France
Authors: Vécrin M.P. , van Diggelen R. , Grévilliot F. , Muller S.
Published: February 2009

Abstract. Attempts to restore species‐rich flood‐plain meadows from abandoned arable fields in the valley of the river Meuse, NE France, were studied. The study area was sown with a commercial seed mixture, composed of Phleumpratense, Festuca pratensis, Lolium perenne and Trifolium repens. The above‐ground vegetation in the study area 1, 2 and 3 yr after restoration was compared to (1) the vegetation present during the previous 5‐yr fallow stage and (2) target flood‐plain meadows. Before restoration, the above‐ground fallow vegetation was dominated by ruderal and annual species, while only very few meadow species were present. Sowing led to tall, dense vegetation, mainly dominated by the sown species. Ruderal and annual species had decreased 3 yr after restoration, but target species were still poorly represented. Species richness was significantly lower in the sown site than in the semi‐natural target meadows and the vegetation had a different composition. Analysis of the soil seed bank of the restored meadow showed that only a few meadow species were present and that it was dominated by a few ruderal species.

Three years after sowing, the vegetation of our experimental site is moving slowly towards the target communities but impoverished seed sources seem to limit the success of this restoration operation and will lead to under‐saturated communities.
Are potential natural vegetation maps a meaningful alternative to neutral landscape models?
Authors: Ricotta Carlo , Carranza Maria Laura , Avena Giancarlo , Blasi Carlo
Published: February 2009

Abstract. In this paper, we present a short overview of neutral landscape models traditionally adopted in the landscape ecological literature to differentiate landscape patterns that are the result of simple random processes from patterns that are generated from more complex ecological processes. Then, we present another family of models based on Tuxen’ s definition of potential natural vegetation that play an important role, especially in Europe, for landscape planning and management. While neutral landscape models by their very nature do not take into account vegetation dynamics, nor abiotic constraints to vegetation distribution, the concept of potential natural vegetation includes the effects of vegetation dynamics in a spatially explicit manner. Therefore, we believe that distribution maps of potential natural vegetation may represent an ecological meaningful alternative to neutral landscape models for evaluating the effects of landscape structure on ecological processes.