bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exposure to dogs is associated with a decreased tumour necrosis factor‐α‐producing capacity in early life
Authors: Lappalainen M. H. J. , Huttunen K. , Roponen M. , Remes S. , Hirvonen M.‐R. , Pekkanen J. 
Published: July 2010

SummaryBackground
It appears that contacts with furred animals early in life and already during gestation contribute to the immunological development in humans, but the mechanisms and relevant exposures are not clear.Objective
To investigate whether exposure to animals during pregnancy and the first year of life is associated with early immune development, determined as stimulated cytokine responses of children at birth and at age 1 year.Methods
Cord blood (n=228) and peripheral venous blood (n=200) samples 1 year after birth were collected and stimulated with Gram‐positive superantigen Staphylococcal enterotoxin B, Gram‐negative bacterial lipopolysaccharide (LPS) and the combination of mitogenic phorbol 12‐myristate 13‐acetate and calcium ionophore ionomycin (P/I) for 24 and 48 h. TNF‐α, IFN‐γ, IL‐5, IL‐8 and IL‐10 responses were measured by ELISA. For each cytokine, the time‐point with the highest response was chosen for further analyses. Animal contacts were surveyed by self‐administered questionnaires.Results
Dog ownership was associated with decreased TNF‐α‐producing capacity at birth (P/I: median 841 vs. 881 pg/106 WBC, P=0.05) and 1 year after birth (P/I: 1290 vs. 1530, P=0.01; LPS: 425 vs. 508, P=0.02). Associations remained significant after adjustment for potential confounders. Cat ownership was not associated with cytokine production.Conclusion
Having a dog in the household in infancy and already during pregnancy may be associated with reduced innate immune responses in early childhood. The observed attenuation of cytokine production may help in preventing exaggerated immune responses against harmless antigens later in life. Thus, intensive exposure to dogs in early life may be beneficial during normal immune maturation. Cite this as: M. H. J. Lappalainen, K. Huttunen, M. Roponen, S. Remes, M.‐R. Hirvonen and J. Pekkanen, Clinical & Experimental Allergy, 2010 (40) 1498–1506.
Towards better prediction of seed dispersal by animals
Authors: Cousens Roger D. , Hill Julian , French Kris , Bishop Ian D. 
Published: July 2010

Summary 1. Animals are the most important dispersal vector for a vast number of terrestrial plants. 2. Whereas our understanding of dispersal by wind has taken enormous conceptual strides in recent years, our ability to predict dispersal patterns by animals remains crude by comparison despite the large volume of research on this topic. 3. We review published models of dispersal by animals, discuss component processes that have been modelled in other contexts and indicate approaches that could usefully be taken in the future. 4. The current problem restricting progress is that few animal dispersal models include the processes most likely to cause dispersal to change over time or space. Thus, they are context‐specific, predicting only under the conditions from which data were collected. 5. The key to deeper understanding is to ask ‘What determines the behaviour of the vector; and what determines the influence of the vector on the trajectory of a seed’ (rather than what is the behaviour of the vector in a case study and how far does it move seeds in that study). This leads naturally to process‐based models with the ability to predict over a range of scenarios. 6. Priority processes for a more mechanistic approach include: animal movement within a landscape; linking gut throughput, defecation, feeding rate and other behaviours; and detachment from an animal’s surface. Models of gut throughput are probably already sufficient to include them in a dispersal model. Perhaps the best way to achieve progress would be to initiate an international working group of experts in modelling and the particular biological processes.
Future atmospheric CO2 leads to delayed autumnal senescence
Authors: TAYLOR GAIL , TALLIS MATTHEW J. , GIARDINA CHRISTIAN P. , PERCY KEVIN E. , MIGLIETTA FRANCO , GUPTA POOJA S. , GIOLI BENIAMINO , CALFAPIETRA CARLO , GIELEN BIRGIT , KUBISKE MARK E. , SCARASCIA‐MUGNOZZA GIUSEPPE E. , KETS KATRE , LONG STEPHEN P. , KARNOSKY DAVID F. 
Published: July 2010

AbstractGrowing seasons are getting longer, a phenomenon partially explained by increasing global temperatures. Recent reports suggest that a strong correlation exists between warming and advances in spring phenology but that a weaker correlation is evident between warming and autumnal events implying that other factors may be influencing the timing of autumnal phenology. Using freely rooted, field‐grown Populus in two Free Air CO2 Enrichment Experiments (AspenFACE and PopFACE), we present evidence from two continents and over 2 years that increasing atmospheric CO2 acts directly to delay autumnal leaf coloration and leaf fall. In an atmosphere enriched in CO2 (by ∼45% of the current atmospheric concentration to 550 ppm) the end of season decline in canopy normalized difference vegetation index (NDVI) – a commonly used global index for vegetation greenness – was significantly delayed, indicating a greener autumnal canopy, relative to that in ambient CO2. This was supported by a significant delay in the decline of autumnal canopy leaf area index in elevated as compared with ambient CO2, and a significantly smaller decline in end of season leaf chlorophyll content. Leaf level photosynthetic activity and carbon uptake in elevated CO2 during the senescence period was also enhanced compared with ambient CO2. The findings reveal a direct effect of rising atmospheric CO2, independent of temperature in delaying autumnal senescence for Populus, an important deciduous forest tree with implications for forest productivity and adaptation to a future high CO2 world.
Revising a process‐based biogeochemistry model (DNDC) to simulate methane emission from rice paddy fields under various residue management and fertilizer regimes
Authors: FUMOTO TAMON , KOBAYASHI KAZUHIKO , LI CHANGSHENG , YAGI KAZUYUKI , HASEGAWA TOSHIHIRO 
Published: July 2010

AbstractA comprehensive biogeochemistry model, DNDC, was revised to simulate crop growth and soil processes more explicitly and improve its ability to estimate methane (CH4) emission from rice paddy fields under a wide range of climatic and agronomic conditions. The revised model simulates rice growth by tracking photosynthesis, respiration, C allocation, tillering, and release of organic C and O2 from roots. For anaerobic soil processes, it quantifies the production of electron donors [H2 and dissolved organic carbon (DOC)] by decomposition and rice root exudation, and simulates CH4 production and other reductive reactions based on the availability of electron donors and acceptors (NO3−, Mn4+, Fe3+, and SO42−). Methane emission through rice is simulated by a diffusion routine based on the conductance of tillers and the CH4 concentration in soil water. The revised DNDC was tested against observations at three rice paddy sites in Japan and China with varying rice residue management and fertilization, and produced estimates consistent with observations for the variation in CH4 emission as a function of residue management. It also successfully predicted the negative effect of (NH4)2SO4 on CH4 emission, which the current model missed. Predicted CH4 emission was highly sensitive to the content of reducible soil Fe3+, which is the dominant electron acceptor in anaerobic soils. The revised DNDC generally gave acceptable predictions of seasonal CH4 emission, but not of daily CH4 fluxes, suggesting the model's immaturity in describing soil heterogeneity or rice cultivar‐specific characteristics of CH4 transport. It also overestimated CH4 emission at one site in a year with low temperatures, suggesting uncertainty in root biomass estimates due to the model's failure to consider the temperature dependence of leaf area development. Nevertheless, the revised DNDC explicitly reflects the effects of soil electron donors and acceptors, and can be used to quantitatively estimate CH4 emissions from rice fields under a range of conditions.
Comparison of phenology trends by land cover class: a case study in the Great Basin, USA
Authors: BRADLEY BETHANY A. , MUSTARD JOHN F. 
Published: July 2010

AbstractDirect impacts of human land use and indirect impacts of anthropogenic climate change may alter land cover and associated ecosystem function, affecting ecological goods and services. Considerable work has been done to identify long‐term global trends in vegetation greenness, which is associated with primary productivity, using remote sensing. Trend analysis of satellite observations is subject to error, and ecosystem change can be confused with interannual variability. However, the relative trends of land cover classes may hold clues about differential ecosystem response to environmental forcing. Our aim was to identify phenological variability and 10‐year trends for the major land cover classes in the Great Basin. This case study involved two steps: a regional, phenology‐based land cover classification and an identification of phenological variability and 10‐year trends stratified by land cover class. The analysis used a 10‐year time series of Advanced Very High Resolution Radiometer satellite data to assess regional scale land cover variability and identify change. The phenology‐based regional classification was more detailed and accurate than national or global products. Phenological variability over the 10‐year period was high, with substantial shifts in timing of start of season of up to 9 weeks. The mean long‐term trends of montane land cover classes were significantly different from valley land cover classes due to a poor response of montane shrubland and pinyon‐juniper woodland to the early 1990s drought. The differential response during the 1990s suggests that valley ecosystems may be more resilient and montane ecosystems more susceptible to prolonged drought. This type of regional‐scale land cover analysis is necessary to characterize current patterns of land cover phenology, distinguish between anthropogenically driven land cover change and interannual variability, and identify ecosystems potentially susceptible to regional and global change.
Effects of climate on population fluctuations of ibex
Authors: GRØTAN VIDAR , SÆTHER BERNT‐ERIK , FILLI FLURIN , ENGEN STEINAR 
Published: July 2010

AbstractPredicting the effects of the expected changes in climate on the dynamics of populations require that critical periods for climate‐induced changes in population size are identified. Based on time series analyses of 26 Swiss ibex (Capra ibex) populations, we show that variation in winter climate affected the annual changes in population size of most of the populations after accounting for the effects of density dependence and demographic stochasticity. In addition, precipitation during early summer also influenced the population fluctuations. This suggests that the major influences of climate on ibex population dynamics operated either through loss of individuals during winter or early summer, or through an effect on fecundity. However, spatial covariation in these climate variables was not able to synchronize the population fluctuations of ibex over larger distances, probably due to large spatial heterogeneity in the effects of single climate variables on different populations. Such spatial variation in the influence of the same climate variable on the local population dynamics suggests that predictions of influences of climate change need to account for local differences in population dynamical responses to climatic conditions.
Infrared heater arrays for warming ecosystem field plots
Authors: KIMBALL BRUCE A. , CONLEY MATTHEW M. , WANG SHIPING , LIN XINGWU , LUO CAIYUN , MORGAN JACK , SMITH DAVID 
Published: July 2010

AbstractThere is a need for methodology to warm open‐field plots in order to study the likely effects of global warming on ecosystems in the future. Herein, we describe the development of arrays of more powerful and efficient infrared heaters with ceramic heating elements. By tilting the heaters at 45° from horizontal and combining six of them in a hexagonal array, good uniformity of warming was achieved across 3‐m‐diameter plots. Moreover, there do not appear to be obstacles (other than financial) to scaling to larger plots. The efficiency [ηh (%); thermal radiation out per electrical energy in] of these heaters was higher than that of the heaters used in most previous infrared heater experiments and can be described by: ηh= 10 + 25exp(− 0.17 u), where u is wind speed at 2 m height (m s− 1). Graphs are presented to estimate operating costs from degrees of warming, two types of plant canopy, and site windiness. Four such arrays were deployed over plots of grass at Haibei, Qinghai, China and another at Cheyenne, Wyoming, USA, along with corresponding reference plots with dummy heaters. Proportional integral derivative systems with infrared thermometers to sense canopy temperatures of the heated and reference plots were used to control the heater outputs. Over month‐long periods at both sites, about 75% of canopy temperature observations were within 0.5 °C of the set‐point temperature differences between heated and reference plots. Electrical power consumption per 3‐m‐diameter plot averaged 58 and 80 kW h day− 1 for Haibei and Cheyenne, respectively. However, the desired temperature differences were set lower at Haibei (1.2 °C daytime, 1.7 °C night) than Cheyenne (1.5 °C daytime, 3.0 °C night), and Cheyenne is a windier site. Thus, we conclude that these hexagonal arrays of ceramic infrared heaters can be a successful temperature free‐air‐controlled enhancement (T‐FACE) system for warming ecosystem field plots.
Climatic connectivity between Africa and Europe may serve as a basis for phenotypic adjustment of migration schedules of trans‐Saharan migratory birds
Authors: SAINO NICOLA , AMBROSINI ROBERTO 
Published: July 2010

AbstractMost European migratory birds wintering in sub‐Saharan Africa have anticipated arrival to the breeding areas over the past decades. This phenological change may be ultimately caused by warming of the Northern Hemisphere via evolutionary changes or phenotypic plasticity in migration behavior. First arrival dates are negatively predicted by temperatures upon arrival to the breeding grounds. This seems puzzling, because migrants should be unable to predict weather conditions at long range. Migrants can enjoy diverse fitness benefits from early arriving. However, if weather conditions at destination cannot be predicted, early arrival can also entail severe costs. If meteorological conditions in Europe during breeding covary with those in sub‐Saharan Africa during late winter, long‐distance migrants may have a clue to predict meteorological conditions in their breeding areas while they are still in Africa and adjust their migration schedule consequently, an idea that has never been tested. We analyzed the correlation between March–April temperature anomalies (Tan) in Europe and FebruaryTanin the Sahel and sub‐Sahel, where long‐distance migrants winter or stop‐over.Tanin Africa negatively predictedTanin Europe, the association being particularly strong (unsigned effect size,zr>0.35) for eastern Sahel and northern and eastern Europe, where the risks of early arrival may be larger. However, the strength of the correlations betweenTanin the two continents has declined during the last 25 years; thus, possibly, partly compromising adaptive mechanisms of adjustment of migration. The existence of such climatic connectivity leads to several predictions, including that positiveTanin Africa should delay arrival. Consistent with this prediction, we found that first arrival dates of seven long‐distance migratory species positively covaried with FebruaryTanin Africa. Thus, while wintering, migrants might be able to predict meteorological conditions at the beginning of the breeding season, and phenotypically adjust migration schedules to optimally tune arrival date.
Combined statistical and dynamical assessment of simulated vegetation–rainfall interactions in North Africa during the mid‐Holocene1
Authors: NOTARO MICHAEL , WANG YI , LIU ZHENGYU , GALLIMORE ROBERT , LEVIS SAMUEL 
Published: July 2010

AbstractA negative feedback of vegetation cover on subsequent annual precipitation is simulated for the mid‐Holocene over North Africa using a fully coupled general circulation model with dynamic vegetation, FOAM‐LPJ (Fast Ocean Atmosphere Model‐Lund Potsdam Jena Model). By computing a vegetation feedback parameter based on lagged auto‐covariances, the simulated impact of North African vegetation on precipitation is statistically quantified. The feedback is also dynamically assessed through initial value ensemble experiments, in which North African grass cover is initially reduced and the climatic response analyzed. The statistical and dynamical assessments of the negative vegetation feedback agree in sign and relative magnitude for FOAM‐LPJ. The negative feedback on annual precipitation largely results from a competition between bare soil evaporation and plant transpiration, with increases in the former outweighing reductions in the latter given reduced grass cover. This negative feedback weakens and eventually reverses sign over time during a transient simulation from the mid‐Holocene to present. A similar, but weaker, negative feedback is identified in Community Climate System Model Version 2 (CCSM2) over North Africa for the mid‐Holocene.
Phosphorus inputs unmask negative effects of ultraviolet radiation on algae in a high mountain lake
Authors: CARRILLO P. , DELGADO‐MOLINA J. A. , MEDINA‐SÁNCHEZ J. M. , BULLEJOS F. J. , VILLAR‐ARGAIZ M. 
Published: July 2010

AbstractUltraviolet solar radiation (UVR) and atmospheric nutrient loads to pristine ecosystems are global climate change phenomena that simultaneously affect aquatic organisms in ways not easily predicted by single factor studies. Plankton in a high mountain lake was exposed in situ to increasing phosphorus (P) concentrations (mimicking atmospheric pulses) in absence or presence of UVR in order to identify their interactive effect on functional [primary production, organic carbon (C) release (EOC), and percentage of C released (%EOC)], growth rate, structural–physiological (algal biomass, sestonic C, P content, chlorophyll a (Chl a), and Chl a : C ratio, P cell quota, cell‐specific Chl a), and stoichiometric (autotroph C : P ratio) traits. The availability of P after the pulse determined the intensity of responses by primary producers to UVR stress. All structural–physiological and functional variables significantly increased by up to two orders of magnitude in response to P enrichment. UV radiation, over a long‐term scale, exerted significant deleterious effects on most structural–physiological variables when inorganic P was added at high levels (≥30 μg P L−1). The subsequent unexpected negative synergistic UVR × P effect on algal development did not support our initial hypothesis that P input might buffer the harmful UVR effect. UVR exerted a weak negative effect on primary production but strongly enhanced the absolute and percentage excretion of C (up to 60%), mechanism responsible of a significant reduction in autotroph C : P ratios. We propose that low sestonic C : P ratios are the outcome of an adaptive strategy of algae in environments with high UVR exposure and extreme nutrient limitation and have important implications for C flux through grazing vs. microbial food webs in oligotrophic systems.
Getting biodiversity intactness indices right: ensuring that ‘biodiversity’ reflects ‘diversity’
Authors: FAITH D. P. , FERRIER S. , WILLIAMS K. J. 
Published: July 2010

AbstractThe 2010 biodiversity target of a ‘significant reduction in the current rate of biodiversity loss’ presents challenges for effective measurement of changes in global/regional biodiversity. A simple ‘biodiversity intactness index’ (BII) is attractive in using available data and expert opinion, but is seen to be only weakly linked to ‘biodiversity’ in its usual sense of ‘variation’. An example illustrates how an improved BII score could result even when there are large species losses. A family of alternative biodiversity ‘representativeness indices’ better reflect variation. They use the same readily available information, plus simple species–area relationships (SAR) and genetic diversity curves. A new genetic‐diversity abundance‐fraction curve, like SAR, is linear in log–log space. The new representativeness indices incorporate, through range‐abundance curves, the abundance fraction estimates normally used for BII. Land use or climate change impacts therefore can reflect partial rather than total biodiversity losses at localities. Estimates of biodiversity gains/losses using these indices enable a novel regional planning‐based approach for addressing the 2010 target.
Nitrogen addition reduces soil respiration in a mature tropical forest in southern China
Authors: MO JIANGMING , ZHANG WEI , ZHU WEIXING , GUNDERSEN PER , FANG YUNTING , LI DEJUN , WANG HUI 
Published: July 2010

AbstractResponse of soil respiration (CO2 emission) to simulated nitrogen (N) deposition in a mature tropical forest in southern China was studied from October 2005 to September 2006. The objective was to test the hypothesis that N addition would reduce soil respiration in N saturated tropical forests. Static chamber and gas chromatography techniques were used to quantify the soil respiration, following four‐levels of N treatments (Control, no N addition; Low‐N, 5 g N m−2 yr−1; Medium‐N, 10 g N m−2 yr−1; and High‐N, 15 g N m−2 yr−1 experimental inputs), which had been applied for 26 months before and continued throughout the respiration measurement period. Results showed that soil respiration exhibited a strong seasonal pattern, with the highest rates found in the warm and wet growing season (April–September) and the lowest rates in the dry dormant season (December–February). Soil respiration rates showed a significant positive exponential relationship with soil temperature, whereas soil moisture only affect soil respiration at dry conditions in the dormant season. Annual accumulative soil respiration was 601±30 g CO2‐C m−2 yr−1 in the Controls. Annual mean soil respiration rate in the Control, Low‐N and Medium‐N treatments (69±3, 72±3 and 63±1 mg CO2‐C m−2 h−1, respectively) did not differ significantly, whereas it was 14% lower in the High‐N treatment (58±3 mg CO2‐C m−2 h−1) compared with the Control treatment, also the temperature sensitivity of respiration, Q10 was reduced from 2.6 in the Control with 2.2 in the High‐N treatment. The decrease in soil respiration occurred in the warm and wet growing season and were correlated with a decrease in soil microbial activities and in fine root biomass in the N‐treated plots. Our results suggest that response of soil respiration to atmospheric N deposition in tropical forests is a decline, but it may vary depending on the rate of N deposition.