bluuebunny/crossref_metadata_2025_split huggingface dataset:
Greater seed production in elevated CO2is not accompanied by reduced seed quality inPinus taedaL.
Authors: WAY DANIELLE A. , LADEAU SHANNON L. , MCCARTHY HEATHER R. , CLARK JAMES S. , OREN RAM , FINZI ADRIEN C. , JACKSON ROBERT B. 
Published: June 2009

AbstractFor herbaceous species, elevated CO2often increases seed production but usually leads to decreased seed quality. However, the effects of increased atmospheric CO2on tree fecundity remain uncertain, despite the importance of reproduction to the composition of future forests. We determined how seed quantity and quality differed for pine trees grown for 12 years in ambient and elevated (ambient+200 μL L−1) CO2, at the Duke Forest free‐air CO2enrichment (FACE) site. We also compared annual reproductive effort with yearly measurements of aboveground net primary productivity (ANPP), precipitation (P), potential evapotranspiration (PET) and water availability [precipitation minus potential evapotranspiration (P−PET)] to investigate factors that may drive interannual variation in seed production. The number of mature, viable seeds doubled per unit basal area in high‐CO2plots from 1997 to 2008 (P<0.001), but there was no CO2effect on mean seed mass, viability, or nutrient content. Interannual variation in seed production was positively related to ANPP, with a similar percentage of ANPP diverted to reproduction across years. Seed production was negatively related to PET (P<0.005) and positively correlated with water availability (P<0.05), but showed no relationship with precipitation (P=0.88). This study adds to the few findings that, unlike herbaceous crops, woody plants may benefit from future atmospheric CO2by producing larger numbers of seeds without suffering degraded seed quality. Differential reproductive responses between functional groups and species could facilitate woody invasions or lead to changes in forest community composition as CO2rises.
Spatial patterns of climatic changes in the Eurasian north reflected in Siberian larch tree‐ring parameters and stable isotopes
Authors: SIDOROVA OLGA V. , SIEGWOLF ROLF T. W. , SAURER MATTHIAS , NAURZBAEV MUKHTAR M. , SHASHKIN ALEXANDER V. , VAGANOV EUGENE A. 
Published: June 2009

AbstractA spatial description of climatic changes along circumpolar regions is presented based on larch tree‐ring width (TRW) index, latewood density (MXD), δ13C, δ18O of whole wood and cellulose chronologies from eastern Taimyr (TAY) and north‐eastern Yakutia (YAK), Russia, for the period 1900–2006, in comparison with a δ13C cellulose chronology from Finland (FIN) and a δ18O ice core record from Greenland (GISP2). Correlation analysis showed a strong positive relationships between TRW, MXD, stable isotope chronologies and June, July air temperatures for TAY and YAK, while the precipitation signal was reflected differently in tree‐ring parameters and stable isotope data for the studied sites. Negative correlations were found between July, August precipitation from TAY and stable isotopes and MXD, while May, July precipitations are reflected in MXD and stable isotopes for the YAK. No significant relationships were found between TRW and precipitation for TAY and YAK. The areas of significant correlations between July gridded temperatures and TRW, MXD and stable isotopes show widespread dimension from east to west for YAK and from north to south for TAY. The climate signal is stronger expressed in whole wood than in cellulose for both Siberian regions. The comparison analysis between δ13C cellulose chronologies from FIN and TAY revealed a similar declining trend over recent decades, which could be explained by the physiological effect of the increasing atmospheric CO2. TRW, MXD and δ13C chronologies from TAY and YAK show a negative correlation with North Atlantic Oscillation index, while the δ18O chronologies show positive correlations, confirming recent warming trend at high latitudes. The strong correlation between GISP2 and δ18O of cellulose from YAK chronologies reflects the large‐scale climatic signal connected by atmospheric circulation patterns expressed by precipitation.
Risk of predation enhances the lethal effects of UV‐B in amphibians
Authors: ALTON LESLEY A. , WILSON ROBBIE S. , FRANKLIN CRAIG E. 
Published: June 2009

AbstractAmphibian declines are a prominent part of the global biodiversity crisis and have received special consideration because they have occurred relatively recently, on a global scale, and in seemingly pristine habitats where no obvious anthropogenic cause is apparent. Although several causes for declines have been implicated, the isolation of a singular cause has proven elusive. Consequently, it has been hypothesized that complex interactions between multiple environmental stressors, particularly those associated with global change, may be responsible. Increasing ultraviolet‐B radiation (UV‐B) associated with stratospheric ozone depletion is one such stressor that has received considerable attention. UV‐B causes enhanced lethal effects when combined with other factors such as aquatic pH, contaminants, temperature and pathogens, but little is known of how UV‐B interacts with pervasive biological stressors, such as risk of predation. We exposed Limnodynastes peronii tadpoles to UV‐B and predatory chemical cues in a controlled laboratory experiment to determine their independent and interactive effects on survival and morphology. We show that UV‐B and risk of predation interact synergistically to enhance mortality above the additive effects of the independent stressors, and that exposure to UV‐B affects the ability of tadpoles to morphologically respond to predatory chemical cues (i.e. predator‐induced phenotypic plasticity), which has implications for their survival in an environment with predators. This highlights the importance of considering both anthropogenic and naturally occurring stressors when examining the underlying causes of amphibian declines.
Global climate change and litter decomposition: more frequent fire slows decomposition and increases the functional importance of invertebrates
Authors: BRENNAN KARL E. C. , CHRISTIE FIONA J. , YORK ALAN 
Published: June 2009

AbstractOf the many mechanisms by which global climate change may alter ecosystem processes perhaps the least known and insidious is altered disturbance regimes. We used a field‐based experiment to examine the climate change scenario of more frequent fires with altered invertebrate assemblages on the decomposition ofEucalyptusleaves. Our design comprised three fire regimes [long‐term fire exclusion (FE), long‐term frequent burning (FB) and FE altered to FB (FEFB)] and two litter bag mesh sizes (8.0 and 0.2 mm) that either permitted or denied access to the leaf litter by most invertebrates. We found a significant interaction effect between fire regime and mesh size in losses of litter mass and net carbon (C). Compared with the regime of FE, with more frequent burning (FB and FEFB) the pace of decomposition was slowed by 41% (when access to litter by most invertebrates is not impeded). For the regime of FE, denying access to leaf litter by most invertebrates did not alter the pace of decomposition. Conversely, under regimes of frequently burning, restricting access to the litter by most invertebrates altered the pace of decomposition by 46%. Similar results were found for net C. For net losses of nitrogen (N), no interaction effects between fire regime and mesh size were detected, although both main effects were significant. Our results show that by modifying disturbance regimes such as fire frequency, global climate change has the potential to modify the mechanism by which ecosystems function. With more FB, decomposition is driven not only by fire regime induced changes in substrate quality and/or physiochemical conditions but through the interaction of disturbance regime with animal assemblages mediating ecosystem processes.
Plasma cell toll‐like receptor (TLR) expression differs from that of B cells, and plasma cell TLR triggering enhances immunoglobulin production
Authors: Dorner Marcus , Brandt Simone , Tinguely Marianne , Zucol Franziska , Bourquin Jean‐Pierre , Zauner Ludwig , Berger Christoph , Bernasconi Michele , Speck Roberto F. , Nadal David 
Published: June 2009

SummaryToll‐like receptors (TLRs) are key receptors of the innate immune system and show cell subset‐specific expression. We investigated the messenger RNA (mRNA) expression of TLR genes in human haematopoietic stem cells (HSC), in naïve B cells, in memory B cells, in plasma cells from palatine tonsils and in plasma cells from peripheral blood. HSC and plasma cells showed unrestricted expression of TLR1–TLR9, in contrast to B cells which lacked TLR3, TLR4 and TLR8 but expressed mRNA of all other TLRs. We demonstrated, for the first time, that TLR triggering of terminally differentiated plasma cells augments immunoglobulin production. Thus, boosting the immediate antibody response by plasma cells upon pathogen recognition may point to a novel role of TLRs.
Toll‐like receptor 4 signalling through MyD88 is essential to control Salmonella enterica serovar Typhimurium infection, but not for the initiation of bacterial clearance
Authors: Talbot Suzanne , Tötemeyer Sabine , Yamamoto Masahiro , Akira Shizuo , Hughes Katherine , Gray David , Barr Tom , Mastroeni Pietro , Maskell Duncan J. , Bryant Clare E. 
Published: June 2009

SummaryToll‐like receptor‐4 (TLR4) is important in protection against lethal Salmonella enterica serovar Typhimurium (S. Typhimurium) infection. Control of the early stages of sublethal S. Typhimurium infection in mice depends on TLR4‐dependent activation of macrophages and natural killer (NK) cells to drive an inflammatory response. TLR4 signals through the adapter proteins Mal/MyD88 and TRIF‐related adaptor molecule (TRAM)/TIR‐domain‐containing adaptor‐inducing interferon‐b (TRIF). In the mouse typhoid model we showed that TLR4 and MyD88, but not Mal or TRIF, are essential for the control of exponential S. Typhimurium growth. TRIF−/− mice have a higher bacterial load in comparison with wild‐type mice during a sublethal infection because TRIF is important for bacterial killing during the first day of systemic disease. Minimal pro‐inflammatory responses were induced by S. Typhimurium infection of macrophages from TLR4−/−, MyD88−/− and TRIF−/− mice in vitro. Pro‐inflammatory responses from Mal−/− macrophages were similar to those from wild‐type cells. The pro‐inflammatory responses of TRIF−/− macrophages were partially restored by the addition of interferon‐γ (IFN‐γ), and TRIF−/− mice produced markedly enhanced IFN‐γ levels, in comparison to wild‐type mice, probably explaining why bacterial growth can be controlled in these mice. TLR4−/−, MyD88−/−, TRIF−/− and Mal−/− mice all initiated clearance of S. Typhimurium, suggesting that TLR4 signalling is not important in driving bacterial clearance in comparison to its critical role in controlling early bacterial growth in mouse typhoid.
Retracted: Dissociated expression of natural killer 1.1 and T‐cell receptor by invariant natural killer T cells after interleukin‐12 receptor and T‐cell receptor signalling
Authors: Emoto Masashi , Shimizu Takamitsu , Koike Hiromi , Yoshizawa Izumi , Hurwitz Robert , Kaufmann Stefan H. E. , Emoto Yoshiko 
Published: June 2009

SummaryInvariant (i) natural killer T (NKT) cells become undetectable after stimulation with α‐galactosylceramide (α‐GalCer) or interleukin (IL)‐12. Although down‐modulation of surface T‐cell receptor (TCR)/NKR‐P1C (NK1.1) expression has been shown convincingly after stimulation with α‐GalCer, it is unclear whether this also holds true for IL‐12 stimulation. To determine whether failure to detect iNKT cells after IL‐12 stimulation is caused by dissociation/internalization of TCR and/or NKR‐P1C, or by block of de novo synthesis of these molecules, and to examine the role of IL‐12 in the disappearance of iNKT cells after stimulation with α‐GalCer, surface (s)/cytoplasmic (c) protein expression, as well as messenger RNA (mRNA) expression of TCR/NKR‐P1C by iNKT cells after stimulation with α‐GalCer or IL‐12, and the influence of IL‐12 neutralization on the down‐modulation of sTCR/sNKR‐P1C expression by iNKT cells after stimulation with α‐GalCer were examined. The s/cTCR+ s/cNKR‐P1C+ iNKT cells became undetectable after in vivo administration of α‐GalCer, which was partially prevented by IL‐12 neutralization. Whereas s/cNKR‐P1C+ iNKT cells became undetectable after in vivo administration of IL‐12, s/cTCR+ iNKT cells were only marginally affected. mRNA expression of TCR/NKR‐P1C remained unaffected by α‐GalCer or IL‐12 treatment, despite the down‐modulation of cTCR and/or cNKR‐P1C protein expression. By contrast, cTCR+ cNKR‐P1C+ sTCR− sNKR‐P1C− iNKT cells and cNKR‐P1C+ sNKR‐P1C− iNKT cells were detectable after in vitro stimulation with α‐GalCer and IL‐12, respectively. Our results indicate that TCR and NKR‐P1C expression by iNKT cells is differentially regulated by signalling through TCR and IL‐12R. They also suggest that IL‐12 participates, in part, in the disappearance of iNKT cells after stimulation with α‐GalCer by down‐modulating not only sNKR‐P1C, but also sTCR.
Effect of damping properties on fracture resistance of root filled premolar teeth: a dynamic finite element analysis
Authors: Ou K‐L. , Chang C‐C. , Chang W‐J. , Lin C‐T. , Chang K‐J. , Huang H‐M 
Published: June 2009

AbstractAim  To evaluate the ex vivo effects of damping on stress concentration in root filled premolar teeth.Methodology  Damping ratios of maxillary premolar teeth that had undergone root canal treatment were tested in a laboratory model. In addition, two‐dimensional finite element (FE) models were established for dynamic analysis.Results  The mean‐damping ratio was significantly lower in premolar teeth that had undergone root canal preparation (8.50 ± 0.53%) than in unprepared teeth (14.42 ± 2.17%) (P < 0.05). However, root filling had a significant positive effect on the damping ratio of the tooth (10.84 ± 1.70%) (P < 0.05). When the damping ratio was taken into consideration, FE analysis revealed that peak stresses in the apical one‐third of the root on the buccal side were reduced by 31.8% when mastication forces were applied on the palatal cusp and occlusal fossa.Conclusion  Pulp tissue plays an important role in providing protective effects when teeth are subjected to a dynamic load. However, root filled teeth do not provide such protective effects.
Root and canal morphology of mandibular first and second molar teeth in a Jordanian population
Authors: Al‐Qudah A. A. , Awawdeh L. A. 
Published: June 2009

AbstractAim  To examine the root and canal morphology of mandibular permanent first and second molar teeth in a Jordanian population.Methodology  A total of 685 extracted mandibular first and second permanent molar teeth were collected from dental clinics within north Jordan. The teeth were examined visually and the root number and morphology were recorded. After that, access cavities were prepared, pulp tissue dissolved by sodium hypochlorite and the root canals injected with Indian ink. Stained teeth were decalcified with 10% nitric acid, dehydrated with ascending concentrations of alcohol and rendered clear by immersion in methyl salicylate. The following observations were evaluated: (i) number of canals per root; (ii) number of root canals per tooth; (iii) canal configuration in each root; (iv) number and location of lateral canals and (v) presence of intercanal communications.Results  Of 330 mandibular first molars, the majority had three (48%) or four (46%) canals, whilst 4% had a third disto‐lingual root. Of 355 mandibular second molars, 58% had three canals, 19% two and 17% had four canals, whilst 10% had C‐shaped roots. The most prevalent canal configuration in the mesial root of both first (53%) and second (40%) molars was type IV, and in distal roots was type I (54% in first and 79% in second molars).Conclusions  Jordanian mandibular first and second molar teeth exhibit features close to the average Caucasian root and canal morphology.
A radiographic assessment of the prevalence of pulp stones in a group of Turkish dental patients
Authors: Gulsahi A. , Cebeci A. I. , Özden S. 
Published: June 2009

AbstractAim  To determine the prevalence of pulp stones in a group of patients using radiographs, and to assess any associations with age, gender, systemic diseases, tooth type, jaw, caries, restorations, impacted third molars and dental anomalies including dens invaginatus, taurodontism, dens evaginatus and microdontia.Methodology  A total of 519 patients were selected randomly amongst patients referred to Oral Diagnosis and Radiology Department, Faculty of Dentistry, Ankara University. After clinical inspection, full‐mouth periapical radiographs were obtained. An oral radiologist examined the radiographs to identify pulp stones. Frequency distribution of teeth with pulp stones was calculated and statistical analysis was performed with chi‐square test.Results  Of the patients, 313 (60%) were female and 206 (40%) were male. Sixty (12%) had one or more teeth that contained pulp stones. Amongst the 13 474 teeth examined radiographically, 627 (5%) had pulp stones. There was no significant association between pulp stone occurrence and gender or systemic diseases. As age increased, the prevalence of pulp stones increased (P < 0.01). Molars had statistically more pulp stones than premolars and incisors (P < 0.001). Frequencies in both maxillary and mandibular jaw were similar. There was no association between pulp stones and impacted third molars, caries, restorations or dental anomalies.Conclusions  The prevalence of pulp stones increased with age and was significantly higher in molar teeth than premolars and incisors. There was no significant association between pulp stones and gender, systemic diseases, impacted third molars, condition of the crown and dental anomalies.
Viability of human fibroblasts in coconut water as a storage medium
Authors: Moreira‐Neto J. J. S. , Gondim J. O. , Raddi M. S. G. , Pansani C. A. 
Published: June 2009

AbstractAim  To evaluate the effectiveness of a new storage medium for avulsed teeth, coconut water, in maintaining the viability of human fibroblasts.Methodology  Cell viability after different time periods was evaluated in the following storage media: coconut water, coconut water with sodium bicarbonate, milk, saline and still mineral water. Human fibroblasts were seeded in Eagle’s minimal essential medium (EMEM) supplemented with 7.5% foetal calf serum. After trypsinisation, 100 μL of culture medium containing approximately 104 cells mL−1 were collected and pipetted into the wells of 96‐well plates, which were incubated overnight in 5% CO2 and 95% air mixture at 37 °C. EMEM was then replaced by the storage media and the plates were incubated at 37 °C for 1, 2 and 4 h. Cell viability was determined using the neutral red assay. The proportions of viable cells after exposure to the storage media were analysed statistically by anova and the least significant difference (LSD) test (α = 5%).Results  Milk had the greatest capacity to maintain cell viability (P < 0.05), followed by coconut water with sodium bicarbonate and saline. Coconut water was significantly worse at maintaining cell viability compared to milk, coconut water with sodium bicarbonate and saline. The smallest number of viable cells was observed for mineral water (P < 0.05).Conclusion  Coconut water was worse than milk in maintaining human fibroblast cell viability.
Microflora in teeth associated with apical periodontitis: a methodological observational study comparing two protocols and three microscopy techniques
Authors: Richardson N. , Mordan N. J. , Figueiredo J. A. P. , Ng Y‐L. , Gulabivala K. 
Published: June 2009

AbstractAim  The aim of this study was to compare two protocols to examine bacterial colonization in teeth associated with chronic apical periodontitis with acute episodes (ap), using light microscopy (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM).Methodology  Nine root samples (seven teeth) were processed using either Eastman Dental Institute (EDI) (n = 4 teeth/4 roots) or Zurich (n = 3 teeth/5 roots) protocols. The roots were sectioned longitudinally; one root portion was viewed with SEM, descriptively dividing its length into apical, middle and coronal; semi‐thin and ultra‐thin transverse sections were viewed under LM and TEM from each third of the other root portion. Each root was therefore examined using all microscopy techniques. Observations of bacterial presence, description and distribution within the root canal lumen and root dentine were systematically recorded using pre‐determined criteria.Results  The Zurich technique gave a more predictable division of the root, but the surface was slightly smeared and demineralization was incomplete. The Eastman Dental Institute (EDI) approach appeared to provide better ultrastructural detail. Bacteria were detected in eight of the nine roots. Bacterial biofilms were commonly seen adhering to the root canal surface, containing various cellular morphotypes: rods, cocci, filaments and spirochaetes. Bacteria were more evident apically than coronally, associated with the canal wall but were more commonly evident coronally than apically within the dentinal tubules. Polymorphs (PMNs) were found in all the root thirds, especially apically, often numerous and walling off the bacterial biofilm from the remaining canal lumen.Conclusions  Both protocols had merits and de‐merits. The combination of microscopy techniques offered complementary views of intra‐radicular bacterial colonization. The perception of confinement of the host/microbial interface at the apical foramen is not entirely correct; PMNs may be found even in the coronal third of root canals containing necrotic pulp tissue.
Maternal investment in relation to sex ratio and offspring number in a small mammal – a case for Trivers and Willard theory?
Authors: Koskela Esa , Mappes Tapio , Niskanen Tuuli , Rutkowska Joanna 
Published: June 2009

Summary 1.  Optimal parental sex allocation depends on the balance between the costs of investing into sons vs. daughters and the benefits calculated as fitness returns. The outcome of this equation varies with the life history of the species, as well as the state of the individual and the quality of the environment. 2.
We studied maternal allocation and subsequent fecundity costs of bank voles, Myodes glareolus, by manipulating both the postnatal sex ratio (all‐male/all‐female litters) and the quality of rearing environment (through manipulation of litter size by −2/+2 pups) of their offspring in a laboratory setting. 3.  We found that mothers clearly biased their allocation to female rather than male offspring regardless of their own body condition. Male pups had a significantly lower growth rate than female pups, so that at weaning, males from enlarged litters were the smallest. Mothers produced more milk for female litters and also defended them more intensively than male offspring. 4.  The results agree with the predictions based on the bank vole life history: there will be selection for greater investment in daughters rather than sons, as a larger size seems to be more influencial for female reproductive success in this species. Our finding could be a general rule in highly polygynous, but weakly dimorphic small mammals where females are territorial. 5.  The results disagree with the narrow sense Trivers & Willard hypothesis, which states that in polygynous mammals that show higher variation in male than in female reproductive success, high‐quality mothers are expected to invest more in sons than in daughters.