bluuebunny/crossref_metadata_2025_split huggingface dataset:
Probiotics in infancy induce protective immune profiles that are characteristic for chronic low‐grade inflammation
Authors: Marschan E. , Kuitunen M. , Kukkonen K. , Poussa T. , Sarnesto A. , Haahtela T. , Korpela R. , Savilahti E. , Vaarala O. 
Published: February 2008

SummaryBackground
Probiotics are widely studied both in the treatment and prevention of allergic diseases, but their mode of action is poorly known.Objective
Our aim was to examine the effect of probiotic bacteria on in vivo cytokine, antibody, and inflammatory responses in allergy‐prone infants.Methods
In a randomized double‐blind study, probiotic bacteria or placebo were given for 1 month before delivery to mothers and for 6 months to infants with a family history of allergy. Plasma samples were analysed for C‐reactive protein (CRP), total IgA and IgE, food‐specific IgA, IgG, and IgE, IL‐2, IL‐4, IL‐6, IL‐10, TNF‐α, and IFN‐γ. We analysed the associations of immunological and inflammatory parameters at age 6 months with probiotic treatment and allergic phenotype at 2 years.Results
Infants receiving probiotic bacteria had higher plasma levels of CRP (P=0.008), total IgA (P=0.016), total IgE (P=0.047), and IL‐10 (P=0.002) than infants in the placebo group. Increased plasma CRP level at age 6 months was associated with a decreased risk of eczema [odds ratio (OR) 0.41 [95% confidence interval (CI) 0.17–0.99], P=0.046], and with a decreased risk of allergic disease [OR 0.38 (95% CI 0.16–0.87), P=0.023] at age 2 years, when adjusted with probiotic use.Conclusion
The association of CRP with a decreased risk of eczema at 2 years of age in allergy‐prone children supports the view that chronic, low‐grade inflammation protects from eczema. Probiotic‐induced low‐grade inflammation was characterized by elevation of IgE, IgA, and IL‐10, the changes typically observed in helminth infection‐associated induction of regulatory mechanisms. The findings emphasize the role of chronic microbial exposure as an immune modulator protecting from allergy.
Reproductive potential of a marine ecosystem engineer at the edge of a newly expanded range
Authors: LING SCOTT D. , JOHNSON C. R. , FRUSHER S. , KING C. K. 
Published: February 2008

AbstractGlobal climate change is leading to redistribution of marine species and altering ecosystem dynamics. Given recent poleward range extension of the barrens‐forming sea urchin Centrostephanus rodgersii (Diadematidae) from mainland Australia to Tasmania, there is a need to understand the population dynamics of this ecologically important species in the Tasmanian environment. This paper informs possible population dynamics of C. rodgersii in Tasmania by examining its reproductive ecology in this new environment. Reproductive periodicity (gonad index and propensity to spawn) was assessed bimonthly over 18 months at four sites in eastern Tasmania spanning ∼2° in latitude. At all sites, C. rodgersii displayed a strong seasonal cycle in gonad production with major spawning occurring in winter (∼August) at minimum annual water temperature. Gametes from Tasmanian C. rodgersii were viable as determined by fertilization and early development trials. However, development to the two‐arm stage at ∼3 weeks was strongly dependent on water temperature across the 8–20 °C temperature range, with poor development occurring below 12 °C. The range of temperatures tolerated by Tasmanian C. rodgersii larvae was similar to that of larvae from its native New South Wales range, indicating that this species has not undergone an adaptive shift to the cooler Tasmanian environment. There was also no evidence for an adaptive shift in reproductive phenology. Importantly, coastal water temperatures in eastern Tasmania during the peak spawning in August fluctuate about the 12 °C larval development threshold. Recent warming of the eastern Tasmanian coast and further warming predicted by global climate change will result in an environment increasingly favourable for the reproduction and development of C. rodgersii.
Microbial activity and soil respiration under nitrogen addition in Alaskan boreal forest
Authors: ALLISON STEVEN D. , CZIMCZIK CLAUDIA I. , TRESEDER KATHLEEN K. 
Published: February 2008

AbstractClimate warming could increase rates of soil organic matter turnover and nutrient mineralization, particularly in northern high‐latitude ecosystems. However, the effects of increasing nutrient availability on microbial processes in these ecosystems are poorly understood. To determine how soil microbes respond to nutrient enrichment, we measured microbial biomass, extracellular enzyme activities, soil respiration, and the community composition of active fungi in nitrogen (N) fertilized soils of a boreal forest in central Alaska. We predicted that N addition would suppress fungal activity relative to bacteria, but stimulate carbon (C)‐degrading enzyme activities and soil respiration. Instead, we found no evidence for a suppression of fungal activity, although fungal sporocarp production declined significantly, and the relative abundance of two fungal taxa changed dramatically with N fertilization. Microbial biomass as measured by chloroform fumigation did not respond to fertilization, nor did the ratio of fungi : bacteria as measured by quantitative polymerase chain reaction. However, microbial biomass C : N ratios narrowed significantly from 16.0 ± 1.4 to 5.2 ± 0.3 with fertilization. N fertilization significantly increased the activity of a cellulose‐degrading enzyme and suppressed the activities of protein‐ and chitin‐degrading enzymes but had no effect on soil respiration rates or 14C signatures. These results indicate that N fertilization alters microbial community composition and allocation to extracellular enzyme production without affecting soil respiration. Thus, our results do not provide evidence for strong microbial feedbacks to the boreal C cycle under climate warming or N addition. However, organic N cycling may decline due to a reduction in the activity of enzymes that target nitrogenous compounds.
The effects of stem density of tropical swards and age of grazing cattle on their foraging behaviour
Authors: Benvenutti M. A. , Gordon I. J. , Poppi D. P. 
Published: February 2008

AbstractThe effects of stem density of tropical swards and age of cattle on their foraging behaviour were evaluated using artificial microswards, consisting of leaves of 20 cm in height and high tensile‐resisting stems of 25 cm in height of Panicum maximum. The treatments consisted of a factorial combination of four stem densities of swards (0, 100, 200 and 400 stems m−2) and two ages of cattle (1‐ and 3‐year‐old steers). There was a significant interaction between stem density of sward and age of cattle for bite area (BA), bite mass (BM) and instantaneous intake rate (IIR). Stem density had a significant negative effect on these variables describing ingestive behaviour which was particularly strong for older steers. In leaf‐only swards, mature cattle achieved a much greater BA (106·5 vs. 57·9 cm2), BM (0·88 vs. 0·47 g DM) and IIR (46·9 vs. 17·2 g DM min−1) than did young cattle. However, these variables were very similar across ages of cattle at the highest stem density of sward. These results show the importance of the high tensile‐resisting stems as deterrents of the grazing process in tropical pastures, particularly in older cattle.
Influence of solar radiation on the productivity and nutritive value of herbage of cool‐season species of an understorey sward in a mature conifer woodland
Authors: Neel J. P. S. , Feldhake C. M. , Belesky D. P. 
Published: February 2008

AbstractSilvopastoral systems in the Appalachian region of the USA could increase the carrying capacity of livestock and contribute to a reliable supply of high‐quality herbage. In 2000, 2001 and 2002, the influence of solar radiation [0·20, 0·50 or 0·80 of maximum solar radiation (MSR); treatments 20‐, 50‐ and 80‐MSR respectively] on the productivity and nutritive value of a mixture of sown grasses and legumes established under a mature stand of conifers was investigated. Yields of dry matter (DM), crude protein (CP), total non‐structural carbohydrates (TNC) and total digestible nutrients (TDN) were greater for the 80‐MSR treatment except in 2000 when DM yield did not differ. As a proportion of the sward, introduced species (Dactylis glomerata L., Trifolium repens L., and Lolium perenne L.) increased over time for the MSR‐80 treatment, corresponding with a decrease in the proportion of bare area and of non‐introduced species. CP concentration of herbage was 207 g kg−1 DM or greater across treatments and years with higher concentrations on the 20‐ and 50‐MSR treatments. Herbage from the 80‐MSR treatment had a greater concentration of TNC than that of the 20‐ and 50‐MSR treatments. Estimated concentration of TDN was similar for all treatments in 2000 and greater for the 80‐MSR treatment than the other two treatments in 2001 and 2002. High CP concentrations in herbage, as a result of appropriate thinning of trees in an Appalachian silvopastoral systems, could be utilized as a protein supplement to herbage with low CP and higher fibre concentrations.
Effect of different grazing management systems on the herbage mass and pasture height of a Nardus stricta grassland in western Scotland, United Kingdom
Authors: Holland J. P. , Waterhouse A. , Robertson D. , Pollock M. L. 
Published: February 2008

AbstractThe aims of this study were to examine the effect of three grazing treatments (year‐round stocking rates of 0·8 ewes ha−1, 0·5 ewes ha−1 and 0·5 ewes ha−1 plus grazing cattle in summer), imposed for 4 years, on the herbage mass and surface height of a Nardus stricta‐dominated grassland in western Scotland and to obtain estimates of annual productivity of this grassland. Nardus stricta‐dominated grassland comprised proportionately 0·20 of the grazing area. Stocking rate of sheep had no significant effect on the herbage mass of the grassland in the first 2 years of the experiment, although mean summer pasture heights were significantly higher under the lower stocking rate of sheep. The pasture on the treatment with cattle grazing in summer had a significantly lower herbage mass and lower surface height than the two sheep‐only grazing treatments. Year‐to‐year variation in the herbage mass and surface height of herbage in summer was greater than the effect of treatments. Despite changes in surface height, the structural diversity of the grasslands was not increased by the treatments. The annual production of vascular plant material ranged from 417 g DM m−2 in 1994 to 628 g DM m−2 in 1996.
Effects of species aggregation, habitat and season on the accuracy of double‐sampling to measure herbage mass in a lowland grassland ecosystem
Authors: Ebrahimi A. , Bossuyt B. , Hoffmann M. 
Published: February 2008

AbstractDouble‐sampling, as a cost‐effective and sufficiently accurate method, is an acknowledged method for estimating herbage mass at the level of the plant species up to the total plant community. It was investigated whether adjusting visual estimations of double‐sampling is applicable at different levels of species aggregation when different seasons and habitats are involved. The method was used in six different habitats of the same ecosystem, a grassland nature reserve in western Belgium, based on eight sampling periods. A general linear model was used to analyse the data at four levels of species aggregation. The correlation between estimated and measured values of herbage mass was significant for the majority of graminoid species at the levels of the sub‐life‐form and total plant community but not at the level of the life‐form. Interaction of habitat type and measured herbage mass, and interaction of date and measured herbage mass, were significant for a minority of species. A significant interaction of both date and habitat with measured herbage mass was found in some cases at the level of the sub‐life‐form and total plant community. Results suggest that the double‐sampling method is reliable for most graminoids and at the sub‐life‐form level, but should be applied more cautiously for forbs species, and when different sampling periods and habitat types are involved at the level of the life‐form. To avoid producing several calibration lines at the level of the species and to overcome deficiency of observations at this level, lumping morphologically similar species from the same vegetation stratum in sub‐life‐form groups is recommended for adjusting estimated herbage mass.
Effect of breed of cattle and season on diet selection and defoliation of competitive plant species in semi‐natural grasslands
Authors: Hessle A. , Wissman J. , Bertilsson J. , Burstedt E. 
Published: February 2008

AbstractTo maintain biodiversity in semi‐natural grasslands, the choice of breed of livestock and season of grazing can be important. The objective was to determine the effects of breed and season on the composition of plant fragments in the faeces of cattle grazing a heterogeneous semi‐natural grassland. Twelve heifers of the traditional Swedish Väneko breed (live weight 309 kg) and twelve heifers of the Charolais breed (live weight 431 kg) were allocated to three pastures per breed. Faeces samples were collected in spring, summer and autumn for micro‐histological examination of plant fragments. On the same occasion, defoliation of four competitive plant species was recorded. Faecal plant fragments mainly consisted of grasses but also herbs, whereas Cyperaceae, despite their abundance on the pastures, only composed a small proportion of fragments. Season affected the composition of plant fragments in the faeces, with a higher proportion of Cyperaceae and herbs in spring than later in the grazing period (P < 0·001), and the heifers ingesting more grasses and woody plants in autumn. In spite of a clear difference in live weight between the two breeds, no effects of breed on the composition of plant fragments in faeces were observed, although Väneko heifers defoliated more Filipendula ulmaria in spring than the Charolais heifers (P < 0·01). In addition, defoliation of Alnus glutinosa increased later in the grazing period (P < 0·05), especially for the Väneko heifers, indicating control of pernicious brushwood by grazing may be more effective in autumn.
Genotype × environment interactions for herbage yield of perennial ryegrass sward plots in Ireland
Authors: Conaghan P. , Casler M. D. , McGilloway D. A. , O’Kiely P. , Dowley L. J. 
Published: February 2008

AbstractPerennial ryegrass (Lolium perenne L.) is by far the most widely sown grass species in Ireland. Genotype × environment (G × E) interactions are a frequent occurrence in herbage yield evaluations. The objectives were to determine (i) the nature and relative magnitudes of the pertinent G × E interaction variance components for dry matter yield of perennial ryegrass sward plots in Ireland and (ii) the optimal allocation of replicates, locations and years in a testing programme. Sixteen perennial ryegrass cultivars were sown at six locations throughout Ireland between 2000 and 2004. Plots from each sowing were harvested for 2 consecutive years under a simulated mixed grazing and conservation management programme. The largest component of the G × E variance was generally genotype × location × year emphasizing the need for evaluation of genotypes across locations and years to adequately characterize genotypes for differences in yield. Relative differences among genotypes from year to year and location to location were due mainly to changes in genotype rankings. Weather was estimated to have a greater effect on annual variation in herbage yield than age of stand. The optimum allocation of resources for a testing programme was estimated at four replicates per location, and either two locations and 3 sowing years or three locations and 2 sowing years with 2 harvest years for each sowing year. The most appropriate option depends on the relative importance of time vs. financial resources.
Fungal contamination of big‐bale grass silage on Irish farms: predominant mould and yeast species and features of bales and silage
Authors: O’Brien M. , O’Kiely P. , Forristal P. D. , Fuller H. T. 
Published: February 2008

AbstractThe extent of visible fungal growth and the identity of the predominant fungi causing spoilage of baled grass silage were recorded on 180 farms in Ireland. Fungal growth was evident on bales on 174 of the 180 farms visited and on 331 of the 360 bales examined. The mean proportion of surface area of bale, that was affected, was 0·06. Silage‐making method, storage characteristics and geographical location were significantly associated with the level of fungal contamination on bales. Fungal contamination was higher (P < 0·001) in bales where the surrounding polythene stretch‐film was visibly damaged compared with bales where the film appeared intact. A strong positive relationship was found between polythene film damage and dry‐matter content of the silage. The predominant fungus affecting the largest numbers of bales wasPenicillium roqueforti. Other fungi frequently isolated includedSchizophyllum commune,Pichia fermentansandPenicillium paneum. The distribution of individual fungi on bales was associated with geographical location, weather at harvest, and lactic and butyric acid concentrations of the silage.Penicillium roquefortiandP. paneumwere more common on bales harvested in dry weather and with higher concentrations of butyric and propionic acids in the silage. Overall, a high incidence of visible fungal growth was recorded on bales throughout the country and the extent of colonization and fungal species occurring were not random.
Effect of offering silage during housing at night on the performance of grazing dairy cows and on labour requirements
Authors: Ferris C. P. , Binnie R. C. , Frost J. P. , Patterson D. C. 
Published: February 2008

AbstractIn the UK, dairy cows are increasingly housed at night throughout the grazing season. However, there is limited information on cow performance and the impact on labour requirements when a forage supplement is offered during housing at night throughout the entire grazing season. The effects of housing at night were studied in two experiments, in which two treatments were compared. On treatment part‐grazing (PG), dairy cows were given access to grazing by day and were offered grass silage while housed at night, and, on treatment continuous grazing (CG), dairy cows were given access to grazing both by day and by night. Experiments 1 (138‐d duration) and 2 (127‐d duration) involved sixty (primiparous) and seventy‐six (primiparous and multiparous) Holstein‐Friesian dairy cows respectively. Concentrates were offered during milking at 4·0 and 3·0 kg per cow per day in Experiments 1 and 2 respectively. In Experiment 1, total milk output was significantly higher with treatment PG than treatment CG (P < 0·01) while the reverse occurred in Experiment 2 (P < 0·001). Milk protein concentration was significantly higher with treatment CG in Experiments 1 and 2 (P < 0·001). Cows on treatment CG in Experiment 2 had significantly higher body condition scores and live weights at the end of experiment than those on treatment PG (P < 0·05). Weekly labour requirements were calculated to be proportionally 0·04 lower on treatment PG than on treatment CG. When offered silage during housing at night, the response of grazing dairy cows was largely determined by the grazing conditions encountered and the quality of the forage offered.
Manipulation of herbage production by altering the pattern of applying nitrogen fertilizer
Authors: Hennessy D. , O’Donovan M. , French P. , Laidlaw A. S. 
Published: February 2008

AbstractThe redistribution of herbage production during the growing season to synchronize herbage supply with feed demand by livestock by altering the application pattern of a range of nitrogen (N) fertilizer rates was studied. Application rates of N were 50, 150 and 250 kg N ha−1 per annum and patterns were with 0·60 of N fertilizer applied before June (treatment RN) and with only 0·20 of N fertilizer before June (treatment IN). Treatments were imposed in a cutting (simulated grazing) experiment (Experiment 1), which was conducted for 2 years and a grazing experiment (Experiment 2) which was conducted for 3 years. In both experiments, herbage production was reduced in April and May and increased in the June–October period on treatment IN relative to RN, but annual herbage production was not significantly affected except in the third year of Experiment 2, when treatment RN had significantly (P < 0·05) higher herbage production than treatment IN. Crude protein (CP) concentration of herbage was lower in April and May on treatment IN than treatment RN. However, CP concentration of herbage was rarely below 150 g kg−1 DM and so it is unlikely that livestock productivity would be compromised. On treatment IN, concentrations of CP in herbage were higher in the late summer than on treatment RN, which may increase livestock productivity during July and August when livestock productivity is often lower. Altering the strategy of application of N fertilizer did not affect in vitro dry matter digestibility of herbage.
Anthropogenic disturbance and the formation of oak savanna in central Kentucky, USA
Authors: McEwan Ryan W. , McCarthy Brian C. 
Published: February 2008

AbstractAim  To deepen understanding of the factors that influenced the formation of oak savanna in central Kentucky, USA. Particular attention was focused on the link between historical disturbance and the formation of savanna ecosystem structure.Location  Central Kentucky, USA.Methods  We used dendrochronological analysis of tree‐ring samples to understand the historical growth environment of remnant savanna stems. We used release detection and branch‐establishment dates to evaluate changes in tree growth and the establishment of savanna physiognomy. We contrasted our growth chronology with reference chronologies for regional tree growth, climate and human population dynamics.Results  Trees growing in Kentucky Inner Bluegrass Region (IBR) savanna remnants exhibited a period of suppression, extending from the establishment date of the tree to release events that occurred c. 1800. This release resulted in a tripling of the annual radial growth rate from levels typical of oaks suppressed under a forest canopy (< 1 mm year−1) to levels typical of open‐grown stems (3 mm year−1). The growth releases in savanna trees coincided with low branch establishment. Over the release period, climatic conditions remained relatively constant and growth in regional forest trees was even; however, the growth increase in savanna stems was strongly correlated with a marked increase in Euro‐American population density in the region.Main conclusions  Our data suggest that trees growing in savanna remnants originated in the understorey of a closed canopy forest. We hypothesize that Euro‐American land clearing to create pasturelands released these trees from light competition and resulted in the savanna physiognomy that is apparent in remnant stands in the IBR. Although our data suggest that savanna trees originated in a forest understorey, this system structure itself may have been a result of an unprecedented lack of Native American activity in the region due to population loss associated with pandemics brought to North America by Euro‐Americans. We present a hypothetical model that links human population dynamics, land‐use activities and ecosystem structure. Our model focuses on the following three land‐use eras: Native American habitation/utilization; land abandonment; and Euro‐American land clearance. Ecological understanding of historical dynamics in other ecosystems of eastern North America may be enhanced through recognition of these eras.