bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ecosystem recovery: heathland response to a reduction in nitrogen deposition
Authors: POWER SALLY A. , GREEN EMMA R. , BARKER CHRIS G. , BELL J. NIGEL B. , ASHMORE MIKE R. 
Published: May 2006

AbstractAtmospheric deposition of nitrogen is responsible for widespread changes in the structure and function of sensitive seminatural ecosystems. The proposed reduction in emissions of nitrogenous pollutants in Europe under the Gothenburg Protocol raises the question of whether affected ecosystems have the potential to recover to their previous condition and, if so, over what timescale. Since 1998, we have monitored the response of a lowland heathland in southern England following the cessation of a long‐term nitrogen addition experiment, and subsequent management, assessing changes in vegetation growth and chemistry, soil chemistry and the soil microbial community. Persistent effects of earlier nutrient loading on Calluna growth and phenology, and on the abundance of lichens, were apparent up to 8 years after nitrogen additions ceased, indicating the potential for long‐term effects of modest nutrient loading (up to 15.4 kg N ha−1 yr−1, over 7 years) on heathland ecosystems. The size and activity of the soil microbial community was elevated in former N‐treated plots, 6–8 years after additions ceased, suggesting a prolonged effect on the rate of nutrient cycling. Although habitat management in 1998 reduced nitrogen stores in plant biomass, effects on belowground nitrogen stores were small. Although some parameters (e.g. soil pH) recover pretreatment levels relatively rapidly, others (e.g. vegetation cover and microbial activity) respond much more slowly, indicating that the ecological effects of even small increases in nitrogen deposition will persist for many years after deposition inputs are reduced. Indeed, calculations suggest that the additional soil nitrogen storage associated with 7 years of experimental nitrogen inputs could sustain the observed effects on plant growth and phenology for several decades. Carry over effects on plant phenology and sensitivity to drought suggest that the persistence of vegetation responses to nitrogen deposition should be integrated into long‐term assessments of the impact of global climate change on sensitive ecosystems.
A matter of timing: changes in the first date of arrival and last date of departure of Australian migratory birds
Authors: BEAUMONT LINDA J. , McALLAN IAN A. W. , HUGHES LESLEY 
Published: May 2006

AbstractAlthough there is substantial evidence that Northern Hemisphere species have responded to climatic change over the last few decades, there is little documented evidence that Southern Hemisphere species have responded in the same way. Here, we report that Australian migratory birds have undergone changes in the first arrival date (FAD) and last date of departure (LDD) of a similar magnitude as species from the Northern Hemisphere. We compiled data on arrival and departure of migratory birds in south‐east Australia since 1960 from the published literature, Bird Observer Reports, and personal observations from bird watchers. Data on the FAD for 24 species and the LDD for 12 species were analyzed. Sixteen species were short‐ to middle‐distance species arriving at their breeding grounds, seven were long‐distance migrants arriving at their nonbreeding grounds, and one was a middle‐distance migrant also arriving at its nonbreeding ground. For 12 species, we gathered data from more than one location, enabling us to assess the consistency of intraspecific trends at different locations. Regressions of climate variables against year show that across south‐east Australia average annual maximum and minimum temperatures have increased by 0.17°C and 0.13°C decade−1 since 1960, respectively. Over this period there has been an average advance in arrival of 3.5 days decade−1; 16 of the 45 time‐series (representing 12 of the 24 species studied) showed a significant trend toward earlier arrival, while only one time‐series showed a significant delay. Conversely, there has been an average delay in departure of 5.1 days decade−1; four of the 21 departure time‐series (four species) showed a significant trend toward later departure, while one species showed a significant trend toward earlier departure. However, differences emerge between the arrival and departure of short‐ to middle‐distance species visiting south‐east Australia to breed compared with long‐distance species that spend their nonbreeding period here. On average, short‐ to middle‐distance migrants have arrived at their breeding grounds 3.1 days decade−1 earlier and delayed departure by 8.1 days decade−1, thus extending the time spent in their breeding grounds by ∼11 days decade−1. The average advance in arrival at the nonbreeding grounds of long‐distance migrants is 6.8 days decade−1. These species, however, have also advanced departure by an average of 6.9 days decade−1. Hence, the length of stay has not changed but rather, the timing of events has advanced. The patterns of change in FAD and LDD of Australian migratory birds are of a similar magnitude to changes undergone by Northern Hemisphere species, and add further evidence that the modest warming experienced over the past few decades has already had significant biological impacts on a global scale.
Lipopolysaccharide induces CXCL2/macrophage inflammatory protein‐2 gene expression in enterocytes via NF‐κB activation: independence from endogenous TNF‐α and platelet‐activating factor
Authors: De Plaen Isabelle G. , Han Xin‐Bing , Liu Xueli , Hsueh Wei , Ghosh Sankar , May Michael J. 
Published: May 2006

SummaryCXCL2 (macrophage inflammatory protein‐2 (MIP‐2)), a critical chemokine for neutrophils, has been shown to be produced in the rat intestine in response to platelet‐activating factor (PAF) and to mediate intestinal inflammation and injury. The intestinal epithelium, constantly exposed to bacterial products, is the first line of defence against micro‐organisms. It has been reported that enterocytes produce proinflammatory mediators, including tumour necrosis factor (TNF) and PAF, and we showed that lipopolysaccharide (LPS) and TNF activate nuclear factor (NF)‐κB in enterocytes. However, it remains elusive whether enterocytes release CXCL2 in response to LPS and TNF via a NF‐κB‐dependent pathway and whether this involves the endogenous production of TNF and PAF. In this study, we found that TNF and LPS markedly induced CXCL2 gene expression in IEC‐6 cells, TNF within 30 min, peaking at 45 min, while LPS more slowly, peaking after 2 hr. TNF‐ and LPS‐ induced CXCL2 gene expression and protein release were completely blocked by pyrrolidine dithiocarbamate (PDTC) and helenalin, two potent NF‐κB inhibitors. NEMO‐binding domain peptide, a specific inhibitor of inhibitor protein κB kinase (IKK) activation, a major upstream kinase mediating NF‐κB activation, significantly blocked CXCL2 gene expression and protein release induced by LPS. WEB2170 (PAF antagonist) and anti‐TNF antibodies had no effect on LPS‐induced CXCL2 expression. In conclusion, CXCL2 gene is expressed in enterocytes in response to both TNF and LPS. LPS‐induced CXCL2 expression is dependent on NF‐κB activation via the IKK pathway. The effect of LPS is independent of endogenous TNF and PAF.
Functional modulation of human intestinal epithelial cell responses by Bifidobacterium infantis and Lactobacillus salivarius
Authors: O'Hara Ann M. , O'Regan Padraig , Fanning Áine , O'Mahony Caitlin , MacSharry John , Lyons Anne , Bienenstock John , O'Mahony Liam , Shanahan Fergus 
Published: May 2006

SummaryIntestinal epithelial cells (IECs) and dendritic cells (DCs) play a pivotal role in antigen sampling and the maintenance of gut homeostasis. However, the interaction of commensal bacteria with the intestinal surface remains incompletely understood. Here we investigated immune cell responses to commensal and pathogenic bacteria. HT‐29 human IECs were incubated with Bifidobacterium infantis 35624, Lactobacillus salivarius UCC118 or Salmonella typhimurium UK1 for varying times, or were pretreated with a probiotic for 2 hr prior to stimulation with S. typhimurium or flagellin. Gene arrays were used to examine inflammatory gene expression. Nuclear factor (NF)‐κB activation, interleukin (IL)‐8 secretion, pathogen adherence to IECs, and mucin‐3 (MUC3) and E‐cadherin gene expression were assayed by TransAM assay, enzyme‐linked immunosorbent assay (ELISA), fluorescence, and real‐time reverse transcriptase–polymerase chain reaction (RT‐PCR), respectively. IL‐10 and tumour necrosis factor (TNF)‐α secretion by bacteria‐treated peripheral blood‐derived DCs were measured using ELISA. S. typhimurium increased expression of 36 of the 847 immune‐related genes assayed, including NF‐κB and IL‐8. The commensal bacteria did not alter expression levels of any of the 847 genes. However, B. infantis and L. salivarius attenuated both IL‐8 secretion at baseline and S. typhimurium‐induced pro‐inflammatory responses. B. infantis also limited flagellin‐induced IL‐8 protein secretion. The commensal bacteria did not increase MUC3or E‐cadherin expression, or interfere with pathogen binding to HT‐29 cells, but they did stimulate IL‐10 and TNF‐α secretion by DCs. The data demonstrate that, although the intestinal epithelium is immunologically quiescent when it encounters B. infantis or L. salivarius, these commensal bacteria exert immunomodulatory effects on intestinal immune cells that mediate host responses to flagellin and enteric pathogens.
Natural killer cells prime the responsiveness of autologous CD4+ T cells to CTLA4‐Ig and interleukin‐10 mediated inhibition in an allogeneic dendritic cell–mixed lymphocyte reaction
Authors: Newland Ashley , Russ Graeme , Krishnan Ravi 
Published: May 2006

SummaryCytotoxic T‐lymphocyte antigen 4 immunoglobulin (CTLA4‐Ig) and interleukin (IL)‐10 are immunomodulatory molecules which target CD28 costimulation by acting either directly or indirectly on the CD80/86 receptors on dendritic cells (DCs). This study examined the effect of combined treatment with CTLA4‐Ig and IL‐10 on T‐cell responsiveness in a dendritic cell–mixed lymphocyte reaction (DC‐MLR). T cells derived from nylon wool enrichment (NWT cells) demonstrated 15% (P = 0·006) and 10% (P = 0·0015) inhibition of proliferation with suboptimal doses of IL‐10 (5 ng/ml) and CTLA4‐Ig (20 ng/ml), respectively. Combined treatment with both agents resulted in 38% inhibition (P = 0·004) of the MLR response compared with untreated controls. In contrast to NWT cells, which consisted of CD4+, CD8+ and CD56+ (NK) cells, purified CD4+ T cells were less responsive to immunomodulation by CTLA4‐Ig and IL‐10. Repletion of the CD4+ T cells with NK cells restored IL‐10 and CTLA4‐Ig mediated immunomodulation, suggesting a role for NK cells in the regulation of DC–T‐cell interactions. The specific effect of NK cells on DC activation was demonstrated by CD80 up‐regulation on DCs in the absence of T cells. However, in the absence of DCs, NK cells augmented the proliferation of autologous CD4+ T cells stimulated by anti‐CD3 monoclonal antibody (mAb), which was blocked by CTLA4‐Ig. It is proposed that, in the MLR, immunomodulation by suboptimal CTLA4‐Ig and IL‐10 is influenced by cellular interactions of NK cells with DCs and T cells involving DC lysis and costimulation. Thus, NK cells prime both DCs and T cells to low doses of CTLA4‐Ig and IL‐10 during alloimmune responses, providing evidence for the potential interaction between innate and adaptive immunity.
Influence of maternal mass and condition on energy transfer in Weddell seals
Authors: WHEATLEY KATHRYN E. , BRADSHAW COREY J. A. , DAVIS LLOYD S. , HARCOURT ROBERT G. , HINDELL MARK A. 
Published: May 2006

Summary

Environmental variation influences food abundance and availability, which is reflected in the reproductive success of top predators. We examined maternal expenditure, offspring mass and condition for Weddell seals in 2 years when individuals exhibited marked differences in these traits.
For females weighing 355 kg there was a positive relationship between maternal post‐partum mass (MPPM) and lactation length, but below this there was no relationship, suggesting that heavier females were able to increase lactation length but lighter females were restricted to a minimum lactation period of 33 days.
Overall, females were heavier in 2002, but in 2003 shorter females were lighter than similar‐sized females in 2002 suggesting that the effects of environmental variability on foraging success and condition are more pronounced in smaller individuals.
There was no relationship between MPPM and pup birth mass, indicating pre‐partum investment did not differ between years. However, there was a positive relationship between MPPM and pup mass gain. Mass and energy transfer efficiency were 10·2 and 5·4% higher in 2002 than 2003, which suggests costs associated with a putatively poor‐resource year were delayed until lactation.
Heavier females lost a higher proportion of mass during lactation in both years, so smaller females may not have been able to provide more to their offspring to wean a pup of similar size to larger females.
MPPM had only a small influence on total body lipid; therefore, regardless of mass, females had the same relative body composition. Females with male pups lost a higher percentage of lipid than those with female pups, but by the end of lactation female pups had 4·5% higher lipid content than males.
It appears that for Weddell seals the consequences of environmentally induced variation in food availability are manifested in differences in maternal mass and expenditure during lactation. These differences translate to changes in pup mass and condition at weaning with potential consequences for future survival and recruitment.
Evaluating the power of monitoring plot designs for detecting long‐term trends in the numbers of common guillemots
Authors: SIMS MICHELLE , WANLESS SARAH , HARRIS MICHAEL P. , MITCHELL P. IAN , ELSTON DAVID A. 
Published: May 2006

Summary

In recent years concerns have been raised regarding the status of the common guillemot Uria aalge in the UK. Numbers have declined in several regions, highlighting the need for continued monitoring of this internationally important population. However, the extent to which the current monitoring scheme is capable of detecting declines and options for improving efficiency has received little attention.
We investigated the power of different monitoring design options for detecting long‐term trends in abundance at a colony of guillemots. The ability to detect trends in abundance was reduced by the large temporal and spatial variability in colony attendance. Taking a linear mixed model approach, we obtained details on the sources and sizes of the variance components using count data collected from monitoring plots on the Isle of May, Scotland, and assessed how best to allocate sampling effort in the light of the count variability structure.
Our results indicated that trend detection will be improved by counting birds in more plots rather than by increasing the number of counts at existing plots.
The revisit pattern of counts at the monitoring plots during the seasonal counting period had little effect on trend detection power. However, given the practical issues associated with counting guillemots, alternative revisit patterns to the current approach are preferred.
For a fixed number of visits per plot, power is strongly influenced by the choice of revisit design if the day‐to‐day variation in colony attendance is increased.
Synthesis and applications. Aspects of the UK seabird monitoring scheme can be improved. Changes to the allocation of sampling effort and the plot‐revisit pattern will improve both the statistical power to detect long‐term trends and the efficiency of conducting the survey. We stress the importance of considering the structure and magnitude of the count variation in a power analysis because judicious design decisions depend on the relative magnitude of these variance components.
A fungal endophyte of black spruce (Picea mariana) needles is also an aquatic hyphomycete
Authors: SOKOLSKI SERGE , PICHÉ YVES , CHAUVET ÉRIC , BÉRUBÉ JEAN A. 
Published: May 2006

AbstractAn aquatic hyphomycete, Dwayaangam sp., was isolated from superficially sterilized black spruce (Picea mariana) needles submerged in aerated water in a small glass chamber (microcosm). The internal transcribed spacer (ITS) sequence of this fungus and of a commonly encountered foliar endophyte isolated from P. mariana showed a high degree of similarity. When sporulation was induced in the microcosm, both the aquatic hyphomycete and the endophyte isolate produced similar aquatic conidia after 30 days, which is longer than previously documented in similar studies. Without the use of molecular tools, the link between the aquatic and endophytic phases of the fungus would have gone unnoticed. This is the first time that a fungal endophyte of conifer needles has been shown to have an aquatic phase. Its presence both as a foliar endophyte and a sporulating aquatic fungus suggests an alternating life cycle between the two environments.
Genetic differentiation in relation to marine landscape in a broadcast‐spawning bivalve mollusc (Placopecten magellanicus)
Authors: KENCHINGTON E. L. , PATWARY M. U. , ZOUROS E. , BIRD C. J. 
Published: May 2006

AbstractMarine bivalves are sessile or sedentary as adults but have planktonic larvae which can potentially disperse over large distances. Consequently larval transport is expected to play a prominent role in facilitating gene flow and determining population structure. The sea scallop (Placopecten magellanicus) is a dioecious species with high fecundity, broadcast spawning and a c. 30‐day planktonic larval stage, yet it forms discrete populations or ‘beds’ which have significantly different dynamics and characteristics. We analysed variation at six microsatellite loci in 12 locations throughout the geographic range of the species from Newfoundland, Canada, to New Jersey, USA. Significant differentiation was present and the maximum pairwise θ value, between one of the Newfoundland samples in the north and a sample from the southern portion of the range, was high at 0.061. Other proximate pairs of samples had no detectable genetic differentiation. Mantel tests indicated a significant isolation by distance, but only when one of the populations was excluded. A landscape genetic approach was used to detect areas of low gene flow using a joint analysis of spatial and genetic information. The two major putative barriers inferred by Monmonier's algorithm were then used to define regions for an analysis of molecular variance (amova). That analysis showed a significant but low percentage (1.2%) of the variation to be partitioned among regions, negligible variation among populations within regions, and the majority of the variance distributed between individuals within populations. Prominent currents were concordant with the demarcation of the regions, while a novel approach of using particle tracking software to mimic scallop larval dispersal was employed to interpret within‐region genetic patterns.
11 Gastric myoelectric activity while viewing and eating food in obese participants
Authors: WANG JY , STERN RM 
Published: May 2006

Purpose:  This study observed the reactions of the stomach to food viewing and food eating in obese people.Method:  The participants were 20 obese (mean BMI of 32) and 20 normal‐weighted (mean BMI of 21) undergraduate students, who were required to fast for at least 4 hours preceding the experiment. They viewed a video clip of food for 6 minutes; consumed food till full; and viewed the same video clip of food 30 minutes after the meal. Cutaneous electrogastrograms (EGGs) were recorded during the entire procedure. Questionnaires concerning the participants’ perception of somatic and affective changes during the tasks were completed.Results:  The percentages of bradygastric, normal and tachygastric EGG activity were very similar between obese group and normal‐weighted group during the baseline period. During the first food image viewing, an increase in normal 3 cpm activity and a decreased in bradygastric activity occurred in both groups, but obese participants showed less of an increase in 3 cpm activity than normal‐weighted participants and the percentage of bradygastric activity was higher in obese group than in the normal‐weighted group. During the 30 min. period following the meal, a higher percentage of bradygastric activity and a lower percentage of 3 cpm activity were observed in obese participants than in normal‐weighted participants. Furthermore, obese participants showed a different pattern of change in 3 cpm and bradygastric activity than normal‐weighed participants during the 30 min. The whole 30‐min period was divided into five 6‐min periods. In the obese group, the percentage of 3 cpm activity decreased in the third and forth 6‐min periods and increased to the highest level in the last 6‐min period, while in the normal‐weighted group, the 3 cpm percentage was the greatest in the first 6‐min period. Obese participants and normal‐weighted participants reacted similarly to the second food image exposure, except that a higher increase in 3 cpm activity was observed in the normal‐weighted group in the period after the termination of viewing the food images.Conclusions:  These data suggest that obese people react to food images and to food eating differently from normal‐weighted people. EGG activity in obese participants needs further investigation.
19 Electrogastrography differentiates enteric myopathy from neuropathy in adults with severe motility disorders of the gut
Authors: ABID S , LINDBERG G 
Published: May 2006

Background:  Chronic intestinal pseudo‐obstruction, enteric dysmotility and slow transit constipation are severe motility disorders of the gut that usually are associated with an underlying enteric neuropathy or myopathy. Electrogastrography (EGG) is a non‐invasive technique that records gastric myoelectric activity.Aim of the study:  To determine whether EGG can differentiate enteric myopathy from neuropathy as the primary pathology in patients with severe motility disorders of the gut.Material and methods:  This is a retrospective analysis of patients with various motility disorders of the gut that underwent full thickness small bowel biopsy. A single bipolar channel measured the EGG. The ability of EGG to differentiate between myopathy and neuropathy was tested by comparing 21 variables from EGG.Results:  A total of 38 patients, 35 (92%) females, mean age 42 ± 13 years, were analysed. Twenty patients had enteric dysmotility (19 with neuropathy and one with myopathy), 12 had slow transit constipation (10 with neuropathy and two with myopathy), and six had chronic intestinal pseudo‐obstruction (three with neuropathy and three with myopathy). Patients with myopathy showed higher percentage of fasting time with DF in bradygastric and tachygastric frequency bands and a higher postprandial DF (Table) than did patients with neuropathic motility disorders.Conclusions:  Patients with visceral myopathy exhibited more arrhythmia during fasting and a higher DF following the test meal and this indicates that myopathies are associated with more electrical disturbances than neuropathies. EGG may be considered for differentiating between these two disease entities.

Comparison of EGG parameters in visceral myopathy and neuropathy

EGG parameter
Myopathy N = (6)
Neuropathy N = (32)
P value

Fasting bradygastria%α
9 (3–14)
0 (0–15)
<0.001

Fasting tachygastria%α
24 (3–42)
8 (0–69)
<0.05

Fasting normal%α
56 (19–94)
88 (31–100)
<0.001

Postprandial DF
3.9 ± 2.5
3.1 ± 0.1
<0.05

DF: Dominant Frequency; α median and range.