bluuebunny/crossref_metadata_2025 huggingface dataset:
Non‐uniqueness with refraction inversion – a syncline model study
Authors: Palmer Derecke
Published: June 2009

Non‐uniqueness occurs with the 1D parametrization of refraction traveltime graphs in the vertical dimension and with the 2D lateral resolution of individual layers in the horizontal dimension. The most common source of non‐uniqueness is the inversion algorithm used to generate the starting model. This study applies 1D, 1.5D and 2D inversion algorithms to traveltime data for a syncline (2D) model, in order to generate starting models for wave path eikonal traveltime tomography.

The 1D tau‐p algorithm produced a tomogram with an anticline rather than a syncline and an artefact with a high seismic velocity. The 2D generalized reciprocal method generated tomograms that accurately reproduced the syncline, together with narrow regions at the thalweg with seismic velocities that are less than and greater than the true seismic velocities as well as the true values.

It is concluded that 2D inversion algorithms, which explicitly identify forward and reverse traveltime data, are required to generate useful starting models in the near‐surface where irregular refractors are common. The most likely tomogram can be selected as either the simplest model or with a priori information, such as head wave amplitudes.

The determination of vertical velocity functions within individual layers is also subject to non‐uniqueness. Depths computed with vertical velocity gradients, which are the default with many tomography programs, are generally 50% greater than those computed with constant velocities for the same traveltime data. The average vertical velocity provides a more accurate measure of depth estimates, where it can be derived.

Non‐uniqueness is a fundamental reality with the inversion of all near‐surface seismic refraction data. Unless specific measures are taken to explicitly address non‐uniqueness, then the production of a single refraction tomogram, which fits the traveltime data to sufficient accuracy, does not necessarily demonstrate that the result is either ‘correct’ or the most probable.
Plant–soil interactions in the expansion and native range of a poleward shifting plant species
Authors: Van GRUNSVEN ROY H. A. , Van Der PUTTEN WIM H. , MARTIJN BEZEMER T. , BERENDSE FRANK , VEENENDAAL ELMAR M.
Published: June 2009

Climate warming causes range shifts of many species toward higher latitudes and altitudes. However, range shifts of host species do not necessarily proceed at the same rates as those of their enemies and symbionts. Here, we examined how a range shifting plant species performs in soil from its original range in comparison with soil from the expansion range. Tragopogon dubius is currently expanding from southern into north‐western Europe and we examined how this plant species responds to soil communities from its original and expansion ranges. We compared the performance of T. dubius with that of the closely related Tragopogon pratensis, which has a natural occurrence along the entire latitudinal gradient. Inoculation with the rhizosphere soil from T. dubius populations of the original range had a more negative effect on plant biomass production than inoculation with rhizosphere soil from the expansion range. Interestingly, the nonrange expander T. pratensis experienced a net negative soil effect throughout this entire range. The effects observed in this species pair may be due to release from soil born enemies or accumulation of beneficial soil born organisms. If this phenomenon applies broadly to other species, then range expansion may enable plants species to show enhanced performance.
Carbon stored in human settlements: the conterminous United States
Authors: CHURKINA GALINA , BROWN DANIEL G. , KEOLEIAN GREGORY
Published: June 2009

Urban areas are home to more than half of the world's people, responsible for >70% of anthropogenic release of carbon dioxide and 76% of wood used for industrial purposes. By 2050 the proportion of the urban population is expected to increase to 70% worldwide. Despite fast rates of change and potential value for mitigation of carbon dioxide emissions, the organic carbon storage in human settlements has not been well quantified. Here, we show that human settlements can store as much carbon per unit area (23–42 kg C m−2urban areas and 7–16 kg C m−2exurban areas) as tropical forests, which have the highest carbon density of natural ecosystems (4–25 kg C m−2). By the year 2000 carbon storage attributed to human settlements of the conterminous United States was 18 Pg of carbon or 10% of its total land carbon storage. Sixty‐four percent of this carbon was attributed to soil, 20% to vegetation, 11% to landfills, and 5% to buildings. To offset rising urban emissions of carbon, regional and national governments should consider how to protect or even to increase carbon storage of human‐dominated landscapes. Rigorous studies addressing carbon budgets of human settlements and vulnerability of their carbon storage are needed.
Exposure to preindustrial, current and future atmospheric CO2 and temperature differentially affects growth and photosynthesis in Eucalyptus
Authors: GHANNOUM OULA , PHILLIPS NATHAN G. , CONROY JANN P. , SMITH RENEE A. , ATTARD RENEE D. , WOODFIELD ROSLYN , LOGAN BARRY A. , LEWIS JAMES D. , TISSUE DAVID T.
Published: June 2009

To investigate if Eucalyptus species have responded to industrial‐age climate change, and how they may respond to a future climate, we measured growth and physiology of fast‐ (E. saligna) and slow‐growing (E. sideroxylon) seedlings exposed to preindustrial (290), current (400) or projected (650 μL L−1) CO2 concentration ([CO2]) and to current or projected (current +4 °C) temperature. To evaluate maximum potential treatment responses, plants were grown with nonlimiting soil moisture. We found that: (1) E. sideroxylon responded more strongly to elevated [CO2] than to elevated temperature, while E. saligna responded similarly to elevated [CO2] and elevated temperature; (2) the transition from preindustrial to current [CO2] did not enhance eucalypt plant growth under ambient temperature, despite enhancing photosynthesis; (3) the transition from current to future [CO2] stimulated both photosynthesis and growth of eucalypts, independent of temperature; and (4) warming enhanced eucalypt growth, independent of future [CO2], despite not affecting photosynthesis. These results suggest large potential carbon sequestration by eucalypts in a future world, and highlight the need to evaluate how future water availability may affect such responses.
Annual wood production in a tropical rain forest in NE Costa Rica linked to climatic variation but not to increasing CO2
Authors: CLARK DAVID B. , CLARK DEBORAH A. , OBERBAUER STEVEN F.
Published: June 2009

Increased atmospheric [CO2] could theoretically lead to increased forest productivity (‘CO2 fertilization’). This mechanism was hypothesized as a possible explanation for biomass increases reported from tropical forests in the last 30+ years. We used unique long‐term records of annually measured stands (eighteen 0.5 ha plots, 10 years) and focal tree species (six species, 24 years) to assess the effects of rainfall, temperature, and atmospheric [CO2] on annual wood production in a neotropical rain forest. Our study area was a meso‐scale section (600 ha) of old‐growth Tropical Wet Forest in NE Costa Rica. Using the repeated remeasurements we directly assessed the relative effects of interannual climatic variation and increasing atmospheric [CO2] on wood production. A remarkably simple two‐factor model explained 91% of the interannual variance in stand‐level tree growth; the statistically independent factors were total dry season rainfall (positive effect, r2=0.85) and night‐time temperature (negative effect, r2=0.42). Stand‐level tree mortality increased significantly with night‐time temperature. After accounting for dry season rainfall and night‐time temperature, there was no effect of annual [CO2] on tree growth in either the stand or focal species data. Tree growth in this Tropical Wet Forest was surprisingly sensitive to the current range of dry season conditions and to variations in mean annual night‐time temperature of 1–2°. Our results suggest that wood production in the lowland rainforests of NE Costa Rica (and by extension in other tropical regions) may be severely reduced in future climates that are only slightly drier and/or warmer.
Oligotrophication outweighs effects of global warming in a large, deep, stratified lake ecosystem
Authors: STICH H. B. , BRINKER ALEXANDER
Published: June 2009

Between 1951 and 1979, total phosphorous concentrations in Lake Constance increased from 7 to 87 μg L−1. Following wastewater treatment, phosphorus levels were brought under control, returning to 7.6 μg L−1 by spring 2007. The biological and chemical data from 1980 to 2004 were first modelled by seasonal time series analyses and then used to create a general model. Excluding collinear variables allowed the data set to be condensed to six variables that could be fitted into a general linear model that explained ∼75% of the observed annual variation in chlorophyll a. A clear seasonal influence was apparent, with chlorophyll a tracking trends in temperature and the progress of spring. A nonseasonal influence was also observed in the interaction of two biological components, the proportion of phytoplankton biomass available to Daphnia (i.e. the percentage of ingestible size <30 μm) and the grazing intensity. In combination, these biotic variables had a negative impact on chlorophyll a levels. In contrast, the concentration of soluble reactive phosphorus (SRP) correlated positively with chlorophyll a. The effect of SRP showed a significant seasonal component, as it was more abundant in spring than at other times of year. In general, the model predicts a negative exponential response of chlorophyll a to further depletion of SRP in Lake Constance, while the temperature trends predicted by current global warming scenarios will result in a moderate increase in productivity. Data from 2005 to 2007 were used to verify the model. The modelled chlorophyll a values were nonbiased and showed a close match to the measured values (r2: 75%). Thus the applicability, reliability, and informative value of the model for pelagic Lake Constance was confirmed. The approach might easily be applied to other waters.
Elevated atmospheric CO2 increases microbial growth rates in soil: results of three CO2 enrichment experiments
Authors: BLAGODATSKAYA EVGENIA , BLAGODATSKY SERGEY , DORODNIKOV MAXIM , KUZYAKOV YAKOV
Published: June 2009

Increasing the belowground translocation of assimilated carbon by plants grown under elevated CO2 can cause a shift in the structure and activity of the microbial community responsible for the turnover of organic matter in soil. We investigated the long‐term effect of elevated CO2 in the atmosphere on microbial biomass and specific growth rates in root‐free and rhizosphere soil. The experiments were conducted under two free air carbon dioxide enrichment (FACE) systems: in Hohenheim and Braunschweig, as well as in the intensively managed forest mesocosm of the Biosphere 2 Laboratory (B2L) in Oracle, AZ. Specific microbial growth rates (μ) were determined using the substrate‐induced respiration response after glucose and/or yeast extract addition to the soil. For B2L and both FACE systems, up to 58% higher μ were observed under elevated vs. ambient CO2, depending on site, plant species and N fertilization. The μ‐values increased linearly with atmospheric CO2 concentration at all three sites. The effect of elevated CO2 on rhizosphere microorganisms was plant dependent and increased for: Brassica napus=Triticum aestivum<Beta vulgaris<Populus deltoides. N deficiency affected microbial growth rates directly (N limitation) and indirectly (changing the quantity of fine roots). So, 50% decrease in N fertilization caused the overall increase or decrease of microbial growth rates depending on plant species. The μ‐value increase was lower for microorganisms growing on yeast extract then for those growing on glucose, i.e. the effect of elevated CO2 was smoothed on rich vs. simple substrate. So, the r/K strategies ratio can be better revealed by studying growth on simple (glucose) than on rich substrate mixtures (yeast extract). Our results clearly showed that the functional characteristics of the soil microbial community (i.e. specific growth rates) rather than total microbial biomass amount are sensitive to increased atmospheric CO2. We conclude that the more abundant available organics released by roots at elevated CO2 altered the ecological strategy of the soil microbial community specifically a shift to a higher contribution of fast‐growing r‐selected species was observed. These changes in functional structure of the soil microbial community may counterbalance higher C input into the soil under elevated atmospheric CO2 concentration.
Biotic interactions may overrule direct climate effects on spring phytoplankton dynamics
Authors: GAEDKE URSULA , RUHENSTROTH‐BAUER MIRIAM , WIEGAND INA , TIROK KATRIN , ABERLE NICOLE , BREITHAUPT PETRA , LENGFELLNER KATHRIN , WOHLERS JULIA , SOMMER ULRICH
Published: June 2009

To improve our mechanistic understanding and predictive capacities with respect to climate change effects on the spring phytoplankton bloom in temperate marine systems, we used a process‐driven dynamical model to disentangle the impact of potentially relevant factors which are often correlated in the field. The model was based on comprehensive indoor mesocosm experiments run at four temperature and three light regimes. It was driven by time‐series of water temperature and irradiance, considered edible and less edible phytoplankton separately, and accounted for density‐dependent grazing losses. It successfully reproduced the observed dynamics of well edible phytoplankton in the different temperature and light treatments. Four major factors influenced spring phytoplankton dynamics: temperature, light (cloudiness), grazing, and the success of overwintering phyto‐ and zooplankton providing the starting biomasses for spring growth. Our study predicts that increasing cloudiness as anticipated for warmer winters for the Baltic Sea region will retard phytoplankton net growth and reduce peak heights. Light had a strong direct effect in contrast to temperature. However, edible phytoplankton was indirectly strongly temperature‐sensitive via grazing which was already important in early spring at moderately high algal biomasses and counter‐intuitively provoked lower and later algal peaks at higher temperatures. Initial phyto‐ and zooplankton composition and biomass also had a strong effect on spring algal dynamics indicating a memory effect via the broadly under‐sampled overwintering plankton community. Unexpectedly, increased initial phytoplankton biomass did not necessarily lead to earlier or higher spring blooms since the effect was counteracted by subsequently enhanced grazing. Increasing temperature will likely exhibit complex indirect effects via changes in overwintering phytoplankton and grazer biomasses and current grazing pressure. Additionally, effects on the phytoplankton composition due to the species‐specific susceptibility to grazing are expected. Hence, we need to consider not only direct but also indirect effects, e.g. biotic interactions, when addressing climate change impacts.
Protease‐activated receptor 2 signalling promotes dendritic cell antigen transport and T‐cell activationin vivo
Authors: Ramelli Giancarlo , Fuertes Silvia , Narayan Sharmal , Busso Nathalie , Acha‐Orbea Hans , So Alexander
Published: June 2009

Deficiency of protease‐activated receptor‐2 (PAR2) modulates inflammation in several models of inflammatory and autoimmune disease, although the underlying mechanism(s) are not understood. PAR2 is expressed on endothelial and immune cells, and is implicated in dendritic cell (DC) differentiation. We investigatedin vivothe impact of PAR2 activation on DCs and T cells in PAR2 wild‐type (WT) and knockout (KO) mice using a specific PAR2 agonist peptide (AP2). PAR2 activation significantly increased the frequency of mature CD11chighDCs in draining lymph nodes 24 hr after AP2 administration. Furthermore, these DCs exhibited increased expression of major histocompatibility complex (MHC) class II and CD86. A significant increase in activated (CD44+ CD62−) CD4+and CD8+T‐cell frequencies was also observed in draining lymph nodes 48 hr after AP2 injection. No detectable change in DC or T‐cell activation profiles was observed in the spleen. The influence of PAR2 signalling on antigen transport to draining lymph nodes was assessed in the context of delayed‐type hypersensitivity. PAR2 WT mice that were sensitized by skin‐painting with fluorescein isothiocyanate (FITC) to induce delayed‐type hypersensitivity possessed elevated proportion of FITC+DCs in draining lymph nodes 24 hr after FITC painting when compared with PAR2 KO mice (0·95% versus 0·47% of total lymph node cells). Collectively, these results demonstrate that PAR2 signalling promotes DC trafficking to the lymph nodes and subsequent T‐cell activation, and thus provides an explanation for the pro‐inflammatory effect of PAR2 in animal models of inflammation.
Natural lysophospholipids reduce Mycobacterium tuberculosis‐induced cytotoxicity and induce anti‐mycobacterial activity by a phagolysosome maturation‐dependent mechanism in A549 type II alveolar epithelial cells
Authors: Greco Emanuela , Santucci Marilina B. , Sali Michela , De Angelis Francesca R. , Papi Massimiliano , De Spirito Marco , Delogu Giovanni , Colizzi Vittorio , Fraziano Maurizio
Published: June 2009

Human alveolar epithelial cells actively contribute to the innate immune response in the lung and play an important role in mycobacterial dissemination during primary infection, by undergoing cell death and by releasing mycobacteria. In the present study, we report that natural lysophospholipids, such as lysophosphatidic acid or sphingosine 1‐phosphate, reduce Mycobacterium tuberculosis‐induced cytotoxicity and enhance anti‐mycobacterial activity in the A549 cell line, used as a model of type II alveolar epithelial cells. Intracellular mycobacterial killing was strictly dependent on phagolysosome maturation, which in turn was promoted by the activation of a Ca2+dependent phospholipase D. Finally, the restriction of mycobacteria in highly microbiocidal compartments was associated, in vitro, with a significant decrease in mycobacterial dissemination to macrophages. Taken as whole, these results suggest that the pulmonary lysophospholipid microenvironment may play a protective role during the early phases of host–pathogen interaction by enhancing anti‐mycobacterial activity in type II alveolar epithelial cells.
An integrated view of the regulation of NKG2D ligands
Authors: Stern‐Ginossar Noam , Mandelboim Ofer
Published: June 2009

NKG2D is one of the best characterized activating receptors and is expressed on natural killer cells and on various T‐cell subsets. This receptor recognizes several different ligands that are induced by cellular stresses. In this review, we described the mechanisms controlling the expression of NKG2D ligands, with the emphasis on post‐transcriptional and post‐translational regulation.
Endodontics or implants? A review of decisive criteria and guidelines for single tooth restorations and full arch reconstructions
Authors: Zitzmann N. U. , Krastl G. , Hecker H. , Walter C. , Weiger R.
Published: June 2009

This review describes practical criteria and a systematic process to aid the treatment planning decision of whether to preserve teeth by root canal treatment (RCT) or extract and provide an implant. Recommendations presented are based on best available evidence from the literature and the expert views of specialists in endodontics and restorative dentistry, including dental implantology. A MEDLINE search was conducted using the terms ‘root canal therapy’, ‘dental implants’, ‘decision making’, ‘treatment planning’, ‘outcome’ and ‘human’, and supplemented by hand‐searching. When evaluating the outcome of root canal treatment, an observation period of 4–5 years is required for complete healing of periapical lesions. Dental implants, however, present a de novo situation and a functional period of at least 5 years is often required before peri‐implant diseases are established and detected. Good long‐term success rates and greater flexibility in clinical management indicate that RCT or retreatment should be performed first in most instances unless the tooth is judged to be unrestorable. When deciding if a compromised tooth of questionable prognosis should be maintained or replaced by an implant, both local, site‐specific and more general patient‐related factors should be considered. Following systematic evaluation and consideration of the best treatment option in a particular case, a treatment recommendation may then be given in favour or against tooth retention. Whilst single risks are possibly accepted for single tooth restorations, teeth with questionable prognosis and multiple pre‐treatment requirements are better not included as abutments in fixed dental prostheses to reduce the risk to survival of the entire restoration.
Apexification: the beginning of its end
Authors: Huang G. T.‐J.
Published: June 2009

Apexification is a procedure for treating and preserving immature permanent teeth that have lost pulp vitality. It contrasts apexogenesis in terms of its outcome in that apical maturation and normal root thickness cannot be obtained. Apexification has been a routine practice for such teeth for many decades, and despite a literature replete with discussion, including recent artificial barrier methods with mineral trioxide aggregate, ultimately there has been no major breakthrough to improve this treatment. Recently, two new clinical concepts have emerged. One involves a revitalization approach to achieve tissue generation and regeneration. In this method, new living tissue is expected to form in the cleaned canal space, allowing continued root development in terms of both length and thickness. The other is the active pursuit of pulp/dentine regeneration via tissue engineering technology to implant or re‐grow pulps. Although the technology is still at its infancy, it has the potential to benefit immature pulpless teeth by allowing continued growth and maturation. With this understanding, it may be predicted that apexification will become less needed in years to come. This study will overview the recent concept of pulp revitalization in the treatment of immature teeth with nonvital pulps and the emerging research on pulp tissue engineering and regeneration.
The prevalence of anterior teeth with dens invaginatus in the western mediterranean region of Turkey
Authors: Kirzioğlu Z. , Ceyhan D.
Published: June 2009

Aim  To assess the prevalence and type of dens invaginatus in anterior teeth of a selected population and to report associated dental complications.

Methodology  The records of patients examined in the Department of Paedodontics, Faculty of Dentistry, Süleyman Demirel University, Isparta, Turkey between 1999 and 2006 were screened and a total of 2477 patients who had complete records with satisfactory radiographs were selected. The type of dens invaginatus and the presence of apical pathosis was determined from radiographs. Other dental abnormalities, syndromes and systemic diseases were noted. Variations in crown shape were also recorded.

Results  Dens invaginatus was detected in 300 out of 2477 patients, with a prevalence of 12%; 82% of affected patients had dens invaginatus bilaterally. Maxillary lateral incisors were the most affected teeth. The majority of the teeth had normal crown morphology (95%). The most commonly seen type of dens invaginatus was type I (94%). Overall 33% of the patients with type III dens invaginatus and 4% of the patients with type II dens invaginatus had apical pathosis. No associations with other systemic diseases and syndromes and some limited association with hypodontia and dens evaginatus were detected.

Conclusion  A carefull oral examination, radiographs, a suitable treatment plan and follow‐up programme are crucial for early diagnosis and treatment for teeth with dens invaginatus.
A comparative study of physicochemical properties of AH Plus, Epiphany, and Epiphany SE root canal sealers
Authors: Resende L. M. , Rached‐Junior F. J. A. , Versiani M. A. , Souza‐Gabriel A. E. , Miranda C. E. S. , Silva‐Sousa Y. T. C. , Sousa Neto M. D.
Published: June 2009

Aim  To assess the physicochemical properties and the surface morphology of AH Plus, Epiphany, and Epiphany SE root canal sealers.

Methodology  Five samples of each material were employed for each test according to ANSI/ADA specification 57. The samples were assigned to four groups: (i) AH Plus; (ii) Epiphany; (iii) Epiphany + Thinning Resin; (iv) Epiphany SE. The distilled water used during the solubility test was submitted to spectrometry to verify the release of calcium ions. The morphologies of the external surface and the cross‐section of the samples were analysed by means of a scanning electron microscope (SEM). Statistical analysis was performed by using One‐Way anova and post hoc Tukey–Kramer tests with the null hypothesis set as 5%.

Results  Setting time, flow and radiopacity results were in accordance with ANSI/ADA requirements whereas the dimensional change of all sealers and solubility of Epiphany did not fulfil ANSI/ADA protocols. AH Plus and Epiphany SE were similar in terms of flow, radiopacity, solubility and dimensional change. The spectrometry test revealed significant calcium ion release from Epiphany with and without the thinning resin. SEM analysis revealed essentially a homogeneous surface with compact layer and some rough areas.

Conclusions  Setting time, flow, and radiopacity tests conformed to ANSI/ADA standardization. The dimensional change in all groups and the solubility of Epiphany were greater than values considered acceptable, with higher amounts of calcium ion release. Epiphany SE revealed more organized, compacted, and homogeneous polymers in a reduced resin matrix when compared with the other groups.
The nociceptive and anti‐nociceptive effects of white mineral trioxide aggregate
Authors: Abbasipour F. , Rastqar A. , Bakhtiar H. , Khalilkhani H. , Aeinehchi M. , Janahmadi M.
Published: June 2009

Aim  To assess the nociceptive and antinociceptive effects of white mineral trioxide aggregate (WMTA) using the orofacial formalin test in rats.

Methodology  Rats (n = 10 in each group) were separately injected into the ipsilateral upper lip with either 40 μL of a 2.5% formalin solution and eugenol (50 mg kg−1) or WMTA (5, 10 and 20 mg dissolved in 0.2 mL saline) alone. In a second experiment to evaluate antinociception effects, 15 min prior to formalin injection, rats were pre‐treated with either white ProRoot MTA (20 mg dissolved in 0.2 mL saline) or eugenol. The time each rat spent rubbing the injected site with its paw, as an index of nociception, was recorded for a period of 45 min.

Results  Administration of 40 μL white ProRoot MTA (5, 10 and 20 mg per 0.2 mL) alone did not produce any significant nociceptive response. Moreover, prior treatment with WMTA caused significant (P < 0.001) inhibition of formalin‐induced nociception. Injection of eugenol (50 mg kg−1) provoked the first phase of a nociceptive response, although its intensity was reduced compared with that produced by formalin. Pre‐treatment with eugenol significantly (P < 0.0001) inhibited the induction of nociception by formalin. Comparison of the behavioural responses observed in WMTA and eugenol‐treated rats alone or in combination with formalin revealed that WMTA did not only induce pain behaviour but also prevented formalin‐induced nociception.

Conclusion  White mineral trioxide aggregate, when compared with eugenol, was more effective in treating nociceptive pain in the orofacial formalin test.
The evaluation of displacement resistance of glass FRC posts to root dentine using a thin slice push‐out test
Authors: Toman M. , Toksavul S. , Sarıkanat M. , Firidinoğlu K. , Akın A.
Published: June 2009

Aim  To investigate and compare the displacement resistance of glass fibre reinforced composite (FRC) posts to root dentine after luting with different adhesive systems.

Methodology  A total of 32 noncarious extracted human mandibular premolars were prepared for post‐cementation using the FRC Postec system (Ivoclar Vivadent, Schaan, Liechtenstein) and divided into four groups (n = 8). The posts in each group were luted with one or other of the following materials. Group 1: Variolink II/Excite DSC (etch‐and‐rinse, dual‐curing), group 2: Clearfil Esthetic Cement/ED Primer II (self‐etch, dual‐curing), group 3: Multilink/Multilink Primer (self‐etch, chemical‐curing) and group 4: Multilink Sprint (self‐adhesive, dual‐curing). Specimens were sectioned to obtain slices with the post in the centre and with the root dentine overlaid by the autopolymerizing acrylic resin on each side. The displacement resistance was measured using a Universal Testing Machine at a crosshead speed of 0.5 mm min−1. The displacement resistance of the specimens were calculated and expressed in MPa. Data were analysed with one‐way anova and post hoc Tukey’s test (P < 0.05).

Results  Mean (SD) values of displacement resistance data in MPa are as follows: group 1, 12.08 (2.13); group 2, 12.39 (2); group 3, 11.3 (1.23); group 4, 14.29 (1.84). There were statistically significant differences amongst the groups (P = 0.021). A statistically significant difference was observed for the displacement resistance values between groups 3 and 4 (P = 0.015), that is between Multilink/Multilink Primer and Multilink Sprint.

Conclusions  Glass FRC posts luted with self‐adhesive luting system exhibited higher displacement resistance than when luted with chemical‐curing self‐etch luting system.
Complicated crown fractures – management and treatment options
Authors: Aggarwal V. , Logani A. , Shah N.
Published: June 2009

Aim  Complicated crown fractures involve enamel, dentine and the pulp. The incidence of complicated crown fractures ranges from 2% to 13% of all dental injuries and the most commonly involved tooth is the maxillary central incisor. Various treatment modalities are available depending upon the clinical, physiological and radiographic status of the involved tooth. The aim of this article was to discuss techniques for the management of complicated crown fractures.

Summary  Management of complicated crown fractures depends upon several factors with the result that various clinical modalities have been suggested. Seven case reports of complicated crown fractures are presented and risks/benefits of the treatment plans are discussed.
Sealing ability, water sorption, solubility and toothbrushing abrasion resistance of temporary filling materials
Authors: Pieper C. M. , Zanchi C. H. , Rodrigues‐Junior S. A. , Moraes R. R. , Pontes L. S. , Bueno M.
Published: June 2009

Aim  To evaluate marginal seal, water sorption, solubility and loss of mass after brushing of several temporary filling materials.

Methodology  For marginal seal, Class I cavities, including endodontic access preparations, were made in human molar teeth and restored using one or other of several temporary filling materials (n = 10): zinc oxide/calcium sulphate‐based cement (Cavit, 3M,ESPE, St. Paul, MN, USA), zinc oxide/eugenol cement (IRM, Dentsply Caulk, Milford, DE, USA), glass ionomer cement (Vidrion R, SSWhite, Rio de Janeiro, RJ, Brazil) or a dimethacrylate‐based filling (Bioplic, Biodinâmica, Londrina, PR, Brazil). Dye penetration was assessed after thermocycling and immersion in 0.5% basic fuchsine solution. For water sorption, solubility and loss of mass analyses, disc‐shaped specimens were made. Water sorption and solubility were evaluated by mass alteration after storage in distilled water for 7 days (n = 7). Loss of mass was calculated based on the difference of mass after abrasion with a toothbrush (n = 5), and surfaces were analysed by SEM. Data of water sorption, solubility and loss of mass were submitted to anova and Tukey’s test, and marginal sealing data to Kruskal–Wallis test (P < 0.05).

Results  Statistically significant differences were observed for marginal sealing (P < 0.0001), water sorption (P < 0.01), solubility (P < 0.01) and loss of mass (P < 0.05). Bioplic had the best marginal seal. Cavit had the greatest water sorption and solubility. Vidrion R and Bioplic had the lowest solubility. Loss of mass after brushing was higher for Cavit, followed by Bioplic, IRM and Vidrion R. Cavit and Vidrion R were worn aggressively by brushing.

Conclusions  The resin‐based temporary filling Bioplic produced the best marginal seal, and was associated with the lowest water sorption, solubility and loss of mass.
Limitations of previously published systematic reviews evaluating the outcome of endodontic treatment
Authors: Wu M‐K. , Shemesh H. , Wesselink P. R.
Published: June 2009

The aim of this work was to identify the limitations of previously published systematic reviews evaluating the outcome of root canal treatment. Traditionally, periapical radiography has been used to assess the outcome of root canal treatment with the absence of a periapical radiolucency being considered a confirmation of a healthy periapex. However, a high percentage of cases confirmed as healthy by radiographs revealed apical periodontitis on cone beam computed tomography (CBCT) and by histology. In teeth, where reduced size of the existing radiolucency was diagnosed by radiographs and considered to represent periapical healing, enlargement of the lesion was frequently confirmed by CBCT. In clinical studies, two additional factors may have further contributed to the overestimation of successful outcomes after root canal treatment: (i) extractions and re‐treatments were rarely recorded as failures; and (ii) the recall rate was often lower than 50%. The periapical index (PAI), frequently used for determination of success, was based on radiographic and histological findings in the periapical region of maxillary incisors. The validity of using PAI for all tooth positions might be questionable, as the thickness of the cortical bone and the position of the root tip in relation with the cortex vary with tooth position. In conclusion, the serious limitations of longitudinal clinical studies restrict the correct interpretation of root canal treatment outcomes. Systematic reviews reporting the success rates of root canal treatment without referring to these limitations may mislead readers. The outcomes of root canal treatment should be re‐evaluated in long‐term longitudinal studies using CBCT and stricter evaluation criteria.
Variation in dispersal mortality and dispersal propensity among individuals: the effects of age, sex and resource availability
Authors: Bowler Diana E. , Benton Tim G.
Published: June 2009

1. Dispersal of individuals between habitat patches depends on both the propensity to emigrate from a patch and the ability to survive inter‐patch movement. Environmental factors and individual characteristics have been shown to influence dispersal rates but separating the effects of emigration and dispersal mortality on dispersal can often be difficult. In this study, we use a soil mite laboratory system to investigate factors affecting emigration and dispersal mortality.

2. We tested the movement of different age groups in two‐patch systems with different inter‐patch distances. Differences in immigration among age groups were primarily driven by differences in emigration but dispersal mortality was greater for some groups. Immigration declined with increasing inter‐patch distance, which was due to increasing dispersal mortality and decreasing emigration.

3. In a second experiment, we compared the dispersal of recently matured males and females and tested the impact of food availability during the developmental period on their dispersal. Dispersal was found to be male biased but there was no significant sex bias in dispersal mortality. There was some evidence that food availability could affect emigration and dispersal mortality.

4. These results demonstrate that both emigration and dispersal mortality can be affected by factors such as individual age and resource availability. Understanding these effects is likely to be important for predicting the fitness costs and population consequences of dispersal.
Assessing landscape connectivity with calibrated cost‐distance modelling: predicting common toad distribution in a context of spreading agriculture
Authors: Janin Agnès , Léna Jean‐Paul , Ray Nicolas , Delacourt Christophe , Allemand Pascal , Joly Pierre
Published: June 2009

1. Capturing the relative influence of landscape composition and configuration in real landscapes remains a challenge. Cost‐distance modelling provides an interesting approach to the assessment of landscape complexity in a functional way. However, resistances allotted to landscape elements in cost‐distance modelling frequently remain defined on the basis of expert advice. To overcome this weakness, we computed resistance coefficients withouta prioriknowledge through a calibration/validation method enabling us to test the impact of the matrix heterogeneity on the occurrence of the common toadBufo bufo,the cycles of which imply migrations between complementary habitats.

2. We used cost‐distance modelling to elaborate an integrative parameter of landscape composition and configuration in the form of a potential movement zone. We first applied a calibration procedure that systematically tested different resistance values for each landscape element with a large data set. The robustness of the calibrated resistances was then evaluated using two supplementary validation data sets from contrasted landscapes. Finally, in order to isolate the relative influence of landscape configuration, we compared the predictive power of the calibrated potential movement zone with that of landscape composition only.

3. The landscape matrix strongly influences common toad occurrence: selected resistances were low for forests and meadows and intermediate to high for crops. Within the two validation data sets, the potential movement zone was positively and significantly related to toad occurrence and had a better predictive power than landscape composition.

4. Synthesis and applications. This study provides a tool to manage landscape structure in accordance with the ecological requirements of amphibian populations, especially habitat complementation. This method has minimal biological information requirements and therefore could be widely used to investigate the crucial influence of landscape composition and configuration on a broad range of species, and to design functional ecological networks.
Spatial covariance between biodiversity and other ecosystem service priorities
Authors: Anderson Barbara J. , Armsworth Paul R. , Eigenbrod Felix , Thomas Chris D. , Gillings Simon , Heinemeyer Andreas , Roy David B. , Gaston Kevin J.
Published: June 2009

1.  Ecosystems support biodiversity and also provide goods and services that are beneficial to humans. The extent to which the locations that are most valuable for ecosystem services coincide with those that support the most biodiversity is of critical importance when designing conservation and land management strategies. There are, however, few studies on which to base any kind of conclusion about possible spatial patterns of association between ecosystem services and biodiversity. Moreover, little is known about the sensitivity of the conclusions to the quality of the data available, or to the choice and size of the region used for analysis.

2.  Here, we first present national‐scale estimates of the spatial covariance in areas important for ecosystem services and biodiversity (richness of species of conservation concern), using Britain as a case study. We then explore how these associations are sensitive to the spatial resolution of the available data, the spatial extent of our study region and to regional variation across the study area.

3.  Our analyses reveal a mixture of negative and positive associations. In particular, the regionalization analysis shows that one can arrive at diametrically opposing conclusions about relationships between ecosystem services and biodiversity by studying the same question within different areas, even within a moderately small island.

4.
 Synthesis and applications. In a policy context, the location‐specific nature of relationships between ecosystem services and biodiversity underscores the importance of multi‐scale environmental decision‐making, so as to reflect both local conditions and broader‐scale priorities. The results also suggest that efforts to establish general patterns of congruence in ecosystem services and biodiversity may offer a less constructive way forward than do more regional approaches.
Assessing biodiversity by remote sensing in mountainous terrain: the potential of LiDAR to predict forest beetle assemblages
Authors: Müller Jörg , Brandl Roland
Published: June 2009

1. Effective biodiversity management can only be implemented if data are available on assemblage–environment relationships. The level of detail needs to be relevant to the scale of planning and decision making. A number of remote‐sensing methods are available, but there are few studies that link information collected at both landscape and local scales. This is particularly true for arthropods even though these organisms are ecologically very important.

2. We assessed the predictive power of habitat variables measured by airborne laser scanning (light detection and ranging; LiDAR) to model the activity, richness and composition of assemblages of forest‐dwelling beetles. We compared the results with data acquired using conventional field methods. We sampled beetles with pitfall traps and flight‐interception traps at 171 sampling stations along an elevation gradient in a montane forest.

3. We found a high predictive power of LiDAR‐derived variables, which captured most of the predictive power of variables measured in ground surveys. In particular, mean body size and species composition of assemblages showed considerable predictability using LiDAR‐derived variables. The differences in the predictability of species richness and diversity of assemblages between trap types can be explained by sample size. We expect predictabilities with R2 of up to 0·6 for samples with 250 individuals on average.

4. The statistical response of beetle data and the ecological interpretability of results showed that airborne laser scanning can be used for cost‐effective mapping (LiDAR : field survey : beetles 15 : 100 : 260 € ha−1) of biodiversity even in remote mountain areas and in structurally complex habitats, such as forests.

5. Synthesis and applications. The strong relationship between characteristics of beetle assemblages to variables derived by laser scanning provides an opportunity to link data from local ground surveys of hyperdiverse taxa to data collected remotely at the landscape scale. This will enable conservation managers to evaluate habitats, define hotspots or map activity, richness and composition of assemblages at scales relevant for planning and management. In addition to the large area that can be sampled remotely, the grain of the data allows a single tree to be identified, which opens up the possibility of planning management actions at local scales.
Clinical significance of low‐grade renal artery stenosis
Authors: Dechering D. G. , Kruis H. M. E. , Adiyaman A. , Thien Th. , Postma C. T.
Published: June 2009

Abstract.  Dechering DG, Kruis HME, Adiyaman A, Thien Th, Postma CT (Radboud University, Nijmegen, The Netherlands, and University Hospital Münster, Münster, Germany). Clinical significance of low‐grade renal artery stenosis. J Intern Med 2010; 267: 305–315.

Background.  Patients with a renal artery stenosis (RAS) >50% carry an increased risk for future cardiovascular (CV) events. Experimental literature on this topic suggests that this might as well be true for subjects with lower‐grade RAS.

Methods.  Recruitment in this longitudinal cohort study was conducted from 1982 to 2002 in a Dutch University Hospital. Included in this study were 301 hypertensive patients clinically suspected of having RAS. Study participants were radiologically classified as having no, a low‐grade (<50% lumen narrowing) or high‐grade (≥50%) RAS. A predetermined composite CV end‐point was defined as one of the following: myocardial infarction or ‘objectified’ angina pectoris, ischaemic stroke or death from any CV cause. Other end‐points were the occurrence of CV complications, all‐cause plus CV mortality and decline in renal function.

Results.  During a median follow‐up of 8.2 years, the incidence of the composite end‐point totalled 79 events. After full adjustment in Cox models, a significant risk increase in high‐grade [hazard ratio (HR) 2.81; P = 0.002] and low‐grade RAS (HR 2.32; P = 0.038) was observed. Other end‐points did not differ significantly between study groups.

Conclusion.  Hypertensive subjects with RAS of any extent, compared with hypertensives without RAS, carry a substantially increased risk for future CV events. Therefore, even in patients with low‐grade RAS, aggressive pharmacological treatment strategies should be adopted as a preventive measure.
Self‐pressurized rapid freezing (SPRF): a novel cryofixation method for specimen preparation in electron microscopy
Authors: LEUNISSEN J.L.M. , YI H.
Published: June 2009

A method is described for the cryofixation of biological specimens for ultrastructural analysis and immunocytochemical detection studies. The method employs plunge freezing of specimens in a sealed capillary tube into a cryogen such as liquid propane or liquid nitrogen. Using this method a number of single‐cell test specimens were well preserved. Also multicellular organisms, such as Caenorhabditis elegans, could be frozen adequately in low ionic strength media or even in water. The preservation of these unprotected specimens is comparable to that achieved with high‐pressure freezing in the presence of cryoprotectant. The results are explained by the fact that cooling of water in a confined space below the melting point gives rise to pressure build‐up, which may originate from the conversion of a fraction of the water content into low‐density hexagonal ice and/or expansion of water during supercooling. Calculations indicate the pressure may be similar in magnitude to that applied in high‐pressure freezing. Because the specimens are plunge cooled, suitable cryogens are not limited to liquid nitrogen. It is shown that a range of cryogens and cryogen temperatures can be used successfully. Because the pressure is generated inside the specimen holders as a result of the cooling rather than applied from an external source as in high‐pressure freezing, the technique has been referred to as self‐pressurized rapid freezing.