bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intraspecific facilitation: a missing process along increasing stress gradients – insights from simulated shrub populations
Authors: Malkinson Dan , Jeltsch Florian 
Published: November 2007

In recent years many field studies have been conducted to assess the relative importance of facilitation and competition in structuring vegetation communities in different environments. Herein, we present a simulation model which systematically explores the relative importance of intra‐specific facilitation and competition between adult shrubs and seedlings for spatial pattern formation. A grid‐based simulation model was constructed and calibrated using data collected in the field from Sarcopoterium spinosum populations in Israel to simulate population dynamics along a rainfall gradient. A series of simulation experiments was conducted in which manipulations of seedling survival probabilities were carried out to assess the relative importance of these processes in generating spatial patterns. Increased survival probabilities of first‐year shrubs in open areas were used to simulate competition effects, while increased survival probabilities in the vicinity of shrubs were used to simulate facilitation effects.Simulation results were then compared to shrub spatial patterns observed in the field. The results indicate that facilitation is not an important process in generating intra‐specific spatial patterns. Rather, in mesic environments with high precipitation, competition is the dominant process generating spatial patterns, resulting in regular spacing of shrubs, similarly to the patterns observed in the field (L(h) values<0). In arid sites, where precipitation values are lower, and stress conditions are higher, the dominant process generating spatial patterns was random mortality due to drought conditions. The resulting spatial patterns in this case are random (L(h)∼0), whereas observed field populations exhibited clumped patterns (L(h)>0). We conclude that as stress conditions increase, the importance of intraspecific neighborhood interactions decrease whereas the importance of environmental factors increase in dictating intra‐specific spatial pattern formation. Consequently in mesic environments intra‐specific competition among adults determines the emerging patterns, while intraspecific facilitation is a negligible process.
A putative RNA‐binding protein has a role in virulence in Ralstonia solanacearum GMI1000
Authors: FRANKS ASHLEY , MARK‐BYRNE G. LOUISE , DOW J. MAXWELL , O’GARA FERGAL 
Published: November 2007

SUMMARYMolecular signals contained in root exudates are thought to induce specific transcriptional changes in bacteria within the rhizosphere, promoting the expression of genes associated with rhizosphere function. We have previously used Pseudomonas aeruginosa PAO1 as a model organism to identify novel genes with roles in rhizosphere competitiveness through analysis of those which showed altered transcription in response to root exudates. One such gene, PA4753, encodes a putative RNA‐binding protein. Homologues of PA4753 occur in other rhizosphere‐associated bacteria, including the phytopathogen Ralstonia solanacearum. In this study, we have tested the role of this homologue, Rsc1524, in the virulence of R. solanacearum GMI1000. Disruption of Rsc1524 resulted in a decrease in virulence in tomato and Arabidopsis. This was associated with an increase in the level of specific extracellular plant wall‐degrading enzymes. Expression of Rsc1524 was influenced by different plant root exudates and root exudate components, which suggests that it may play a role in molecular signalling between bacteria and plants underpinning wilt pathogenesis.
A randomised, crossover comparison between the CobraPLA® and the LMA Classic™ in paralysed patients*
Authors: Nam S. B. , Han D. W. , Chang C. H. , Lee J. S. 
Published: November 2007

SummaryWe performed a randomised, crossover study in 38 anaesthetised and paralysed patients to compare the performance of the CobraPLA® and the LMA Classic™ during controlled ventilation. The median (IQR [range]) airway leak pressure was 23.0 (20–24 [12–30]) cmH2O for the CobraPLA and 15.0 (12–19 [8–30]) cmH2O for the LMA Classic (p < 0.001). The median (IQR [range]) insertion time was 15.0 (11–26 [9–31]) s for the CobraPLA and 22.5 (20–25 [15–50]) s for the LMA Classic (p < 0.001). There was no significant difference between the two devices for the number of insertion and reposition attempts, the anatomical position scored by fibreoptic bronchoscopy or the peak and plateau airway pressures. There were no adverse events during anaesthesia. The CobraPLA provides a better airway leak pressure and takes less time to insert than the LMA Classic in paralysed patients. Our data show that the CobraPLA can be used to secure a patent airway during controlled ventilation in selected patients.
Pulmonary function and inflammatory markers in patients undergoing coronary revascularisation with or without cardiopulmonary bypass
Authors: Heijmans J. H. , Liem K. S. A. E. , Damoiseaux G. M. C. , Maessen J. G. , Roekaerts P. M. H. J. 
Published: November 2007

SummaryLung injury after cardiac surgery is believed to result from cardiopulmonary bypass and its pro‐inflammatory effects. To test this hypothesis, we compared the oxygenation ratios, extravascular lung water indices and systemic and pulmonary tumour necrosis factor alpha (TNF‐α) and interleukin (IL)‐8 at predetermined intervals in coronary artery surgery patients with or without cardiopulmonary bypass. No differences in oxygenation ratios or extravascular lung water indices were found. Serum values of TNF‐α and IL‐8 increased in both groups but were higher in the cardiopulmonary bypass group (end of surgery: mean (SD) TNF‐α 3.68 (2.5) vs 2.20 (1.2) pg.ml−1 (p = 0.043 (CI 0.05–2.9)) and mean (SD) IL‐8 19.45 (10.8) vs 6.31 (5.3) pg.ml−1 (p = 0.001 (CI 6.9–19.3)). In broncho‐alveolar lavage fluid, TNF‐α and IL‐8 increased in both groups with no differences between the groups.
Contamination of anaesthetic machines with pathogenic organisms*
Authors: Baillie J. K. , Sultan P. , Graveling E. , Forrest C. , Lafong C. 
Published: November 2007

SummaryHospital‐acquired infections are commonly resistant to antibiotics and cause substantial morbidity and mortality in susceptible populations. Although there is no direct contact between the anaesthetic machine's controls and the patient, there is considerable potential for colonising organisms to be carried between the anaesthetic machine and the patient on the anaesthetist's hands. We performed two cross‐sectional studies of bacterial contamination on anaesthetic machines before and after a simple intervention. Without warning, during theatre sessions, bacterial cultures were obtained from anaesthetic equipment. A new departmental policy of cleaning anaesthetic equipment with detergent wipes between cases was then introduced. Six weeks later, again without warning, a further set of cultures was taken. There was significant reduction in the proportion of cultures containing pathogenic bacteria (from 14/78 cultures (18%; 95% CI 9.4–26.5%) before the intervention to 5/77 cultures (6%; 95% CI 1.0–12%) after the intervention (p = 0.03)). The intervention was quick, easy and enthusiastically taken up by the majority of staff. We conclude that cleaning of anaesthetic equipment between cases should become routine practice.
The role of liquid‐based cytology in the investigation of thyroid lesions
Authors: Stamataki M. , Anninos D. , Brountzos E. , Georgoulakis J. , Panayiotides J. , Christoni Z. , Peros G. , Karakitsos P. 
Published: November 2007

Objective:  This study investigates the role of liquid‐based cytology by ThinPrep® technique in the detection of thyroid lesions.Methods:  In all, 252 specimens from 157 patients for pre‐operative evaluation of thyroid nodules, prepared by the ThinPrep®, were examined. In all cases thyroidectomy followed the initial cytological evaluation. All cytological diagnoses were correlated to the histological ones.Results:  According to our findings, a sensitivity of 87.80%, a specificity of 99.50%, a positive predictive value of 97.30%, a negative predictive value of 97.56% and an overall accuracy of 97.52% were observed in fine needle aspiration cytology in correlation to the histological diagnosis after thyroidectomy.Conclusions:  ThinPrep® technique is a valid method for the pre‐operative cytological diagnosis of thyroid nodules, offering the possibility of ancillary techniques, such as immunocytochemical and molecular methods and can, therefore, be potentially complementary to histological evaluation for further investigation of follicular lesions.
Non‐enzymatic hydrolysis of fluorescein diacetate (FDA) in a Mediterranean oak (Quercus ilex L.) litter
Authors: Alarcón‐Gutiérrez E. , Floch C. , Ruaudel F. , Criquet S. 
Published: November 2007

SummaryWe show the presence of interfering substances when the total microbial activity in litter samples is measured with fluorescein diacetate (FDA), and we propose some methodological modifications to avoid such interference. Three distinct litter layers (the OhLn, the OhLv and the OhLf) of evergreen oak (Quercus ilex L.) were characterized by 13C CPMAS NMR and the spectra show that the recalcitrant aromatic and phenolic compounds increase with the degree of degradation of litter. A wide range of sources of interference in the hydrolysis of FDA was found. To understand the origin of this interference, sterilized litter materials (i.e. γ‐irradiated or autoclaved) and a wide range of organic substances (i.e. amino acids, glucose, sorbitol and organic humic acids) were investigated. Insignificant differences on the FDA hydrolysis activity (FDA activity) were found in the γ‐irradiated and non‐irradiated OhLn litter, indicating that γ‐irradiation does not destroy enzymes. Conversely, after heat‐sterilization of litter, samples showed FDA activity corresponding to 60, 34.8 and 30.8% (in the OhLn, the OhLv and the OhLf layers, respectively) of that of control litters. This indicates the presence of non‐enzymatic interfering substances in the FDA assays. As the humification and litter depth increased, hydrolysis of FDA due to interferences decreased, indicating degradation and/or chelation of interfering substances. We hypothesize that lysine, arginine, histidine and cysteine are mainly responsible for the hydrolysis of FDA. We suggest that the use of phosphate buffer (50 mm, pH 7.0) with incubation < 30 minutes, in combination with a temperature between 30 and 40°C, produces insignificant interference in the determination of the final FDA activity in litter samples.
Soil podzolization induced by reforestation as shown by sequential and kinetic extractions of Fe and Al
Authors: Cornu S. , Besnault A. , Bermond A. 
Published: November 2007

SummaryThe impact of 60‐year‐old reforestation on soil evolution was studied by following the evolution of Fe and Al distribution as an indicator of early podzolization. We determined the distribution of Al and Fe in soils by combining sequential and kinetic extractions. We extracted the soil sequentially with: 1 mol litre−1 sodium acetate at pH 5.5 (stage 1); twice with 0.1 mol litre−1 sodium pyrophosphate at pH 10 (stage 2 and 2b); and with 1 mol litre−1 hydroxylamine in 4.3 mol litre−1 acetic acid solution at 90°C (stage 3). For each, we drew a kinetic‐extraction curve. We show that no re‐adsorption, precipitation or complexation with dissolved organic matter occurred for the reaction times recommended in this procedure, that is 6 hours for stage 1, 1.5 hours for stage 2 and 2b and 3 hours for stage 3. For a given extraction, the kinetic curves have the same shape for all samples, that is their behaviour is similar for a given reagent. Sequential extraction can therefore be used to compare the speciation of metals in different samples taken from the same soil. In addition, 60 years after reforestation by beech, a decrease of 12 and 17% is noted in the total Fe and Al contents, respectively, in the 0–10 cm layer, accompanied by a re‐distribution of these elements within the different soil compartments: a decrease of the Fe and Al bound to oxy‐hydroxide in favour of organic complexes and more soluble forms. Sequential extraction is therefore a good indicator of the first pedogenetic modifications induced by human intervention through reforestation.
The impact of successive infections on the lung microenvironment
Authors: Didierlaurent Arnaud , Goulding John , Hussell Tracy 
Published: November 2007

SummaryThe effect of infection history on the immune response is ignored in most models of infectious disease and in preclinical vaccination studies. No one, however, is naïve and repeated microbial exposure, in particular during childhood, shapes the immune system to respond more efficiently later in life. Concurrent or sequential infections influence the immune response to secondary unrelated pathogens. The involvement of cross‐reactive acquired immunity, in particular T‐cell responses, is extensively documented. In this review, we discuss the impact of successive infections on the infected tissue itself, with a particular focus on the innate response of the respiratory tract, including a persistent alteration of (1) epithelial or macrophage expression of Toll‐like receptors or adherence molecules used by subsequent bacteria to invade the host, (2) the responsiveness of macrophages and neutrophils and (3) the local cytokine milieu that affects the activation of local antigen‐presenting cells and hence adaptive immunity to the next infection. We emphasize that such alterations not only occur during coinfection, but are maintained long after the initial pathogen is cleared. As innate responses are crucial to the fight against local pathogens but are also involved in the maintenance of the homeostasis of mucosal tissues, dysregulation of these responses by repeated infections is likely to have a major impact on the outcome of infectious or allergic disease.
Importance of sampling design and analysis in animal population studies: a comment on Sergio et al.
Authors: Kéry Marc , Royle J. Andrew , Schmid Hans 
Published: November 2007

Summary

The use of predators as indicators and umbrellas in conservation has been criticized. In the Trentino region, Sergio et al. (2006; hereafter SEA) counted almost twice as many bird species in quadrats located in raptor territories than in controls. However, SEA detected astonishingly few species. We used contemporary Swiss Breeding Bird Survey data from an adjacent region and a novel statistical model that corrects for overlooked species to estimate the expected number of bird species per quadrat in that region.
There are two anomalies in SEA which render their results ambiguous. First, SEA detected on average only 6·8 species, whereas a value of 32 might be expected. Hence, they probably overlooked almost 80% of all species. Secondly, the precision of their mean species counts was greater in two‐thirds of cases than in the unlikely case that all quadrats harboured exactly the same number of equally detectable species. This suggests that they detected consistently only a biased, unrepresentative subset of species.
Conceptually, expected species counts are the product of true species number and species detectability p. Plenty of factors may affect p, including date, hour, observer, previous knowledge of a site and mobbing behaviour of passerines in the presence of predators. Such differences in p between raptor and control quadrats could have easily created the observed effects. Without a method that corrects for such biases, or without quantitative evidence that species detectability was indeed similar between raptor and control quadrats, the meaning of SEA's counts is hard to evaluate. Therefore, the evidence presented by SEA in favour of raptors as indicator species for enhanced levels of biodiversity remains inconclusive.
Synthesis and application. Ecologists should pay greater attention to sampling design and analysis in animal population estimation. Species richness estimation means sampling a community. Samples should be representative for the community studied and the sampling fraction among communities compared should be the same on average, otherwise formal estimation approaches must be applied to avoid misleading inference.
Genome scans detect consistent divergent selection among subtidal vs. intertidal populations of the marine angiosperm Zostera marina
Authors: OETJEN KATHARINA , REUSCH THORSTEN B. H. 
Published: November 2007

AbstractGenome scans are a powerful tool to detect natural selection in natural populations among a larger sample of marker loci. We used replicated habitat comparisons to search for consistent signals of selection among contrasting populations of the seagrass Zostera marina, a marine flowering plant with important ecological functions. We compared two different habitat types in the North Frisian Wadden Sea, either permanently submerged (subtidal) or subjected to aerial exposure (intertidal). In three independent population pairs, each consisting of one tidal creek and one tidal flat population each, we carried out a genome scan with 14 expressed sequence tag (EST)‐derived microsatellites situated in 5′‐ or 3′‐untranslated regions of putative genes, in addition to 11 anonymous genomic microsatellites. By using two approaches for outlier identification, one anonymous and two EST‐derived microsatellites showed population differentiation patterns not consistent with neutrality. These microsatellites were detected in several parallel population comparisons, suggesting that they are under diverging selection. One of these loci is linked to a putative nodulin gene, which is responsible for water channelling across cellular membranes, suggesting a functional link of the observed genetic divergence with habitat characteristics.
Severe respiratory disorders in term neonates
Authors: Gouyon Jean‐Bernard , Ribakovsky C. , Ferdynus C. , Quantin C. , Sagot P. , Gouyon B. ,   Burgundy Perinatal Network
Published: November 2007

SummaryFew prospective population‐based studies of respiratory diseases have been conducted in term neonates. We aimed to describe mechanically ventilated respiratory disorders in term neonates and associated risk factors in a regional‐based study of livebirths between 37 and 41 weeks. The study was prospective for epidemiological data recording, and retrospective for collecting additional data from charts of neonates with severe (mechanically ventilated) respiratory disorders.A total of 14 813 neonates with gestational age (GA) 37–38 weeks and 50 187 neonates with GA 39–41 weeks were included. The overall incidences (per thousand livebirths) of mechanically ventilated transient tachypnoea of the newborn (TTN) respiratory distress syndrome (RDS) and meconium aspiration syndrome (MAS) were 0.72‰[95% CI 0.53‰, 0.96‰], 0.38‰[95% CI 0.25‰, 0.57‰] and 0.61‰[95% CI 0.44‰, 0.84‰], respectively. Increasing GA from 37 to 41 weeks was associated with a significant decrease in incidence of RDS and TTN without any significant change for MAS.Multivariable analysis was used to identify independent factors associated with severe respiratory disorders: in the 37–38 weeks group – Apgar score ≤3 at 1 min, elective caesarean section (CS), emergency CS and placental abruption; in the 39–41 weeks group – Apgar score ≤3 at 1 min, elective CS, emergency CS, meconium‐stained amniotic fluid and abnormal cardiotocography. Comparing the population attributable risks, the main risk factor of severe respiratory disorders was elective CS in the 37–38 weeks group and meconium‐stained amniotic fluid in the 39–41 weeks group.
A review of the ecology and management of Ranunculus acris subsp. acris in pasture
Authors: LAMOUREAUX S L , BOURDÔT G W 
Published: November 2007

Summary Ranunculus acris subsp. acris is widespread in pastures across Europe. In New Zealand, it persists in dairy pastures throughout the country, despite the annual use of herbicides, causing a loss in the national yield of milk solids estimated at NZ$156 million in the 2001–2002 milking season. Its persistence appears to be due in part to the production of a blistering agent, protoanemonin, which deters grazing animals, combined with evolved resistance to herbicides and a resilience imparted by a stout rhizome supporting dormant axillary buds. The latter enables regeneration after damage inflicted by herbicides, fungi and other control agents, and facilitates lateral spread and asexual reproduction. Its persistence in dairy pastures may also be influenced by plants recruiting from seeds which are formed annually subject to the availability of insect pollinators. Based on a review of observations and experiments conducted mainly in Europe and New Zealand, we propose a detailed life‐cycle model for R. acris. This provides the basis for a matrix population model that will identify the life‐cycle stages that contribute most to population growth and, hence, the extent to which each of these would need to be targeted for improved management in dairy pastures in New Zealand.
Genetic variation in transforming growth factor‐beta1 gene associated with increased risk of esophageal squamous cell carcinoma
Authors: Wei Y.‐S. , Xu Q.‐Q. , Wang C.‐F. , Pan Y. , Liang F. , Long X.‐K. 
Published: November 2007

AbstractThe genetic alterations leading to esophageal squamous cell carcinoma (ESCC) are gradually being discovered. A wide variety of genes have been associated with ESCC development as well as tumor progression. Transforming growth factor‐β1 (TGF‐β1) is a multifunctional cytokine; it promotes tumor growth and metastasis in later stages of of cancer development. Variations in the DNA sequence in the TGF‐β1 gene may lead to altered TGF‐β1 production and/or activity, and so this can modulate an individual’s susceptibility to ESCC. To test this hypothesis, we investigated the association of the TGF‐β1 gene −509 C/T and 869 T/C (Leu10Pro) polymorphisms and their haplotypes with the risk of ESCC. 247 patients with ESCC and 260 age‐ and sex‐matched controls were studied using a polymerase chain reaction–restriction fragment length polymorphism. There were significant differences in the genotype and allele distribution of 869 T/C polymorphism of the TGF‐β1 gene among cases and controls. The 869 TC and CC genotypes were associated with a significantly increased risk of ESCC as compared with the 869 TT genotypes [odds ratio (OR) = 1.882, 95% confidence interval (CI) 1.212–2.923, P = 0.005 and OR = 2.099, 95% CI 1.288–3.421, P = 0.003, respectively]. Consistent with the results of the genotyping analyses, the –509 T/869 C haplotype was associated with a significantly increased risk of ESCC as compared with the –509 C/869 T haplotype (OR = 1.463; 95% CI 1.120–1.912; P = 0.005). This study shows for the first time that TGF‐β1 gene 869 T/C polymorphism may contribute to a genetic risk factor for ESCC in a Chinese population.
Severe acute graft‐vs‐host disease in a patient with acute monocytic leukemia having a recombination event between HLA‐A/B loci from a multiple recombinant family
Authors: Sun Y. , Kong F. , Ren S. , Yuan F. , Liang F. , Liu N. , Jin L. , Xi Y. 
Published: November 2007

AbstractHuman leukocyte antigen (HLA) recombination, particularly multiple recombinations can produce novel haplotypes, thereby complicating donor–recipient selection and possibly inducing severe graft‐vs‐host disease (GVHD) after nonfully matched allogeneic hematopoietic stem cell transplantation. Here, we report for the first time that a 30‐year‐old female acute monocytic leukemia patient with an HLA‐A/B recombinant haplotype, who has three unmatched and one HLA‐B/DRB1 recombinant haplotype siblings, presented grade IV acute GVHD (aGVHD) after transplantation from a sibling with a single allele only mismatch at the classical HLA‐A locus. Furthermore, using a new three‐dimensional structure modeling application, we inferred that the structural differences in peptide‐binding and T‐cell receptor interaction sites can significantly change the immunogenicity of mismatched HLA molecules, potentially one of the main causes of aGVHD.