bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nickel acts as an adjuvant during cobalt sensitization
Authors: Bonefeld Charlotte Menné , Nielsen Morten Milek , Vennegaard Marie T. , Johansen Jeanne Duus , Geisler Carsten , Thyssen Jacob P. 
Published: January 2015

AbstractMetal allergy is the most frequent form of contact allergy with nickel and cobalt being the main culprits. Typically, exposure comes from metal‐alloys where nickel and cobalt co‐exist. Importantly, very little is known about how co‐exposure to nickel and cobalt affects the immune system. We investigated these effects by using a recently developed mouse model. Mice were epicutaneously sensitized with i) nickel alone, ii) nickel in the presence of cobalt, iii) cobalt alone, or iv) cobalt in the presence of nickel, and then followed by challenge with either nickel or cobalt alone. We found that sensitization with nickel alone induced more local inflammation than cobalt alone as measured by increased ear‐swelling. Furthermore, the presence of nickel during sensitization to cobalt led to a stronger challenge response to cobalt as seen by increased ear‐swelling and increased B and T cell responses in the draining lymph nodes compared to mice sensitized with cobalt alone. In contrast, the presence of cobalt during nickel sensitization only induced an increased CD8+ T cell proliferation during challenge to nickel. Thus, the presence of nickel during cobalt sensitization potentiated the challenge response against cobalt more than the presence of cobalt during sensitization to nickel affected the challenge response against nickel. Taken together, our study demonstrates that sensitization with a mixture of nickel and cobalt leads to an increased immune response to both nickel and cobalt, especially to cobalt, and furthermore that the adjuvant effect appears to correlate with the inflammatory properties of the allergen..
The role of vegetation–microclimate feedback in promoting shrub encroachment in the northern Chihuahuan desert
Authors: He Yufei , D'Odorico Paolo , De Wekker Stephan F.J. 
Published: January 2015

AbstractMany arid and semi‐arid landscapes around the world are affected by a shift from grassland to shrubland vegetation, presumably induced by climate warming, increasing atmospheric CO2 concentrations, and/or changing land use. This major change in vegetation cover is likely sustained by positive feedbacks with the physical environment. Recent research has focused on a feedback with microclimate, whereby cold intolerant shrubs increase the minimum nocturnal temperatures in their surroundings. Despite the rich literature on the impact of land cover change on local climate conditions, changes in microclimate resulting from shrub expansion into desert grasslands have remained poorly investigated. It is unclear to what extent such a feedback can affect the maximum extent of shrub expansion and the configuration of a stable encroachment front. Here, we focus on the case of the northern Chihuahuan desert, where creosotebush (Larrea tridentata) has been replacing grasslands over the past 100–150 years. We use a process‐based coupled atmosphere‐vegetation model to investigate the role of this feedback in sustaining shrub encroachment in the region. Simulations indicate that the feedback allows juvenile shrubs to establish in the grassland during average years and, once established, reduce their vulnerability to freeze‐induced mortality by creating a warmer microclimate. Such a feedback is crucial in extreme cold winters as it may reduce shrub mortality. We identify the existence of a critical zone in the surroundings of the encroachment front, in which vegetation dynamics are bistable: in this zone, vegetation can be stable both as grassland and as shrubland. The existence of these alternative stable states explains why in most cases the shift from grass to shrub cover is found to be abrupt and often difficult to revert.
The linkages between photosynthesis, productivity, growth and biomass in lowland Amazonian forests
Authors: Malhi Yadvinder , Doughty Christopher E. , Goldsmith Gregory R. , Metcalfe Daniel B. , Girardin Cécile A. J. , Marthews Toby R. , del Aguila‐Pasquel Jhon , Aragão Luiz E. O. C. , Araujo‐Murakami Alejandro , Brando Paulo , da Costa Antonio C. L. , Silva‐Espejo Javier E. , Farfán Amézquita Filio , Galbraith David R. , Quesada Carlos A. , Rocha Wanderley , Salinas‐Revilla Norma , Silvério Divino , Meir Patrick , Phillips Oliver L. 
Published: January 2015

AbstractUnderstanding the relationship between photosynthesis, net primary productivity and growth in forest ecosystems is key to understanding how these ecosystems will respond to global anthropogenic change, yet the linkages among these components are rarely explored in detail. We provide the first comprehensive description of the productivity, respiration and carbon allocation of contrasting lowland Amazonian forests spanning gradients in seasonal water deficit and soil fertility. Using the largest data set assembled to date, ten sites in three countries all studied with a standardized methodology, we find that (i) gross primary productivity (GPP) has a simple relationship with seasonal water deficit, but that (ii) site‐to‐site variations in GPP have little power in explaining site‐to‐site spatial variations in net primary productivity (NPP) or growth because of concomitant changes in carbon use efficiency (CUE), and conversely, the woody growth rate of a tropical forest is a very poor proxy for its productivity. Moreover, (iii) spatial patterns of biomass are much more driven by patterns of residence times (i.e. tree mortality rates) than by spatial variation in productivity or tree growth. Current theory and models of tropical forest carbon cycling under projected scenarios of global atmospheric change can benefit from advancing beyond a focus on GPP. By improving our understanding of poorly understood processes such as CUE, NPP allocation and biomass turnover times, we can provide more complete and mechanistic approaches to linking climate and tropical forest carbon cycling.
Urgent need for warming experiments in tropical forests
Authors: Cavaleri Molly A. , Reed Sasha C. , Smith W. Kolby , Wood Tana E. 
Published: January 2015

AbstractAlthough tropical forests account for only a fraction of the planet's terrestrial surface, they exchange more carbon dioxide with the atmosphere than any other biome on Earth, and thus play a disproportionate role in the global climate. In the next 20 years, the tropics will experience unprecedented warming, yet there is exceedingly high uncertainty about their potential responses to this imminent climatic change. Here, we prioritize research approaches given both funding and logistical constraints in order to resolve major uncertainties about how tropical forests function and also to improve predictive capacity of earth system models. We investigate overall model uncertainty of tropical latitudes and explore the scientific benefits and inevitable trade‐offs inherent in large‐scale manipulative field experiments. With a Coupled Model Intercomparison Project Phase 5 analysis, we found that model variability in projected net ecosystem production was nearly 3 times greater in the tropics than for any other latitude. Through a review of the most current literature, we concluded that manipulative warming experiments are vital to accurately predict future tropical forest carbon balance, and we further recommend the establishment of a network of comparable studies spanning gradients of precipitation, edaphic qualities, plant types, and/or land use change. We provide arguments for long‐term, single‐factor warming experiments that incorporate warming of the most biogeochemically active ecosystem components (i.e. leaves, roots, soil microbes). Hypothesis testing of underlying mechanisms should be a priority, along with improving model parameterization and constraints. No single tropical forest is representative of all tropical forests; therefore logistical feasibility should be the most important consideration for locating large‐scale manipulative experiments. Above all, we advocate for multi‐faceted research programs, and we offer arguments for what we consider the most powerful and urgent way forward in order to improve our understanding of tropical forest responses to climate change.
Climate warming and agricultural stressors interact to determine stream macroinvertebrate community dynamics
Authors: Piggott Jeremy J. , Townsend Colin R. , Matthaei Christoph D. 
Published: January 2015

AbstractGlobal climate change is likely to modify the ecological consequences of currently acting stressors, but potentially important interactions between climate warming and land‐use related stressors remain largely unknown. Agriculture affects streams and rivers worldwide, including via nutrient enrichment and increased fine sediment input. We manipulated nutrients (simulating agricultural run‐off) and deposited fine sediment (simulating agricultural erosion) (two levels each) and water temperature (eight levels, 0–6°C above ambient) simultaneously in 128 streamside mesocosms to determine the individual and combined effects of the three stressors on macroinvertebrate community dynamics (community composition and body size structure of benthic, drift and insect emergence assemblages). All three stressors had pervasive individual effects, but in combination often produced additive or antagonistic outcomes. Changes in benthic community composition showed a complex interplay among habitat quality (with or without sediment), resource availability (with or without nutrient enrichment) and the behavioural/physiological tendency to drift or emerge as temperature rose. The presence of sediment and raised temperature both resulted in a community of smaller organisms. Deposited fine sediment strongly increased the propensity to drift. Stressor effects were most prominent in the benthic assemblage, frequently reflected by opposite patterns in individuals quitting the benthos (in terms of their propensity to drift or emerge). Of particular importance is that community measures of stream health routinely used around the world (taxon richness, EPT richness and diversity) all showed complex three‐way interactions, with either a consistently stronger temperature response or a reversal of its direction when one or both agricultural stressors were also in operation. The negative effects of added fine sediment, which were often stronger at raised temperatures, suggest that streams already impacted by high sediment loads may be further degraded under a warming climate. However, the degree to which this will occur may also depend on in‐stream nutrient conditions.
Rain events decrease boreal peatland net CO2 uptake through reduced light availability
Authors: Nijp Jelmer J. , Limpens Juul , Metselaar Klaas , Peichl Matthias , Nilsson Mats B. , van der Zee Sjoerd E. A. T. M. , Berendse Frank 
Published: January 2015

AbstractBoreal peatlands store large amounts of carbon, reflecting their important role in the global carbon cycle. The short‐term exchange and the long‐term storage of atmospheric carbon dioxide (CO2) in these ecosystems are closely associated with the permanently wet surface conditions and are susceptible to drought. Especially, the single most important peat forming plant genus, Sphagnum, depends heavily on surface wetness for its primary production. Changes in rainfall patterns are expected to affect surface wetness, but how this transient rewetting affects net ecosystem exchange of CO2 (NEE) remains unknown. This study explores how the timing and characteristics of rain events during photosynthetic active periods, that is daytime, affect peatland NEE and whether rain event associated changes in environmental conditions modify this response (e.g. water table, radiation, vapour pressure deficit, temperature). We analysed an 11‐year time series of half‐hourly eddy covariance and meteorological measurements from Degerö Stormyr, a boreal peatland in northern Sweden. Our results show that daytime rain events systematically decreased the sink strength of peatlands for atmospheric CO2. The decrease was best explained by rain associated reduction in light, rather than by rain characteristics or drought length. An average daytime growing season rain event reduced net ecosystem CO2 uptake by 0.23–0.54 gC m−2. On an annual basis, this reduction of net CO2 uptake corresponds to 24% of the annual net CO2 uptake (NEE) of the study site, equivalent to a 4.4% reduction of gross primary production (GPP) during the growing season. We conclude that reduced light availability associated with rain events is more important in explaining the NEE response to rain events than rain characteristics and changes in water availability. This suggests that peatland CO2 uptake is highly sensitive to changes in cloud cover formation and to altered rainfall regimes, a process hitherto largely ignored.
Combination of heat treatment and chitosan coating to improve postharvest quality of wolfberry (Lycium barbarum)
Authors: Ban Zhaojun , Wei Wenwen , Yang Xiangzheng , Feng Jianhua , Guan Junfeng , Li Li 
Published: January 2015

SummaryThe synergistic application of hot water dip at 42 °C for 30 min and 1% chitosan coating on differentiation in postharvest quality traits, microstructure as well as microbiological evolution of wolfberry fruits was investigated. Fresh wolfberry fruits were stored at 2 ± 0.5 °C and 90% relative humidity (RH) for 28 days. Results indicated the combination of prestorage heat treatment and chitosan coating maintained higher levels of ascorbic acid, total phenolic contents and antioxidant capacity as well as lower decay, compared with untreated wolfberry fruits. The possible mechanism was that the heat treatment almost sealed open stomata to limit the sites of pathogen penetration into fruits independently, followed by the biofilm formed by chitosan which controlled secondary infections as well as slowed changes in fruit respiration and metabolic activity in wolfberries. The synergistically treated fruit also exhibited a higher acceptability obtained by sensory analysis after cold storage. In this sense, the integrated application of heat treatment and chitosan coating could be regarded as an effective strategy to extend storage life and maintain the postharvest quality of wolfberry fruits.
Influence of extraction methods on functional properties of protein concentrates prepared from South African bambara groundnut landraces
Authors: Arise Abimbola K. , Amonsou Eric O. , Ijabadeniyi Oluwatosin A. 
Published: January 2015

SummaryFunctional properties of protein concentrates prepared from three bambara groundnut landraces using acid precipitation and salt solubilisation methods were evaluated. The protein content of bambara grains (26–27%) was similar for the three landraces. The acid precipitation gave a much higher yield of protein concentrates (52%), which were also high in protein (79%) compared to the salt solubilisation method (yield: 25%, protein content: 57%). Functional properties of proteins were more influenced by the methods of preparation rather than the landraces. Protein concentrate prepared by salt solubilisation method showed higher emulsifying (63–66%), foaming (53–57%), water (1.4–2.0 mg mL−1) and oil absorption properties (2.2–2.6 mg mL−1) than the acid‐precipitated concentrates (53–57%, 63–66%, 2.0–2.7 mg mL−1, 1.4–1.7 mg mL−1). The foaming capacity and stability of all the protein concentrates decreased with increasing pH from 3 to 8. Salt solubilisation may be the most appropriate method for the enhanced functionality and utilisation of bambara groundnuts’ protein concentrates.
Elucidation of colour development and microstructural characteristics of Allium sativum fumigated with acetic acid
Authors: Li Li , Wang Dan , Li Xihong , Wang Yu , Ju Xiaofeng 
Published: January 2015

SummaryIt has been well known that the greening of Allium sativum cloves could be formed after immersed in acetic acid solution. Nonetheless, no investigation was reported on colour development of A. sativum in response to acetic acid vapour until now. In this study, the brief exposure of A. sativum to acetic acid vapour (200–400 ppm) was combined with controlled atmosphere (5%, 20% and 80% CO2) packaging storage to break cell membrane and green garlic. The garlic bulbs were fumigated with acetic acid before controlled CO2 atmosphere packaging for 25 days at 4 °C. Fumigation with 200 ppm acetic acid followed by high CO2 atmosphere packaging (80% CO2) facilitated the garlic greening. It was also verified that γ‐glutamyl transpeptidase was involved in garlic greening in present study, and the compromise of glacial acetic acid vapour fumigation and CO2 gas atmosphere in package stored at low temperature could result in garlic greening as well.
Effect of enterohaemorrhagic Escherichia coli O157:H7‐specific enterohaemolysin on interleukin‐1β production differs between human and mouse macrophages due to the different sensitivity of NLRP3 activation
Authors: Cheng Yu‐Li , Song Li‐qiong , Huang Yuan‐Ming , Xiong Yan‐Wen , Zhang Xiao‐Ai , Sun Hui , Zhu Xin‐Ping , Meng Guang‐Xun , Xu Jian‐Guo , Ren Zhi‐Hong 
Published: January 2015

SummaryEnterohaemorrhagic Escherichia coli (EHEC) O157:H7 infection in humans can cause acute haemorrhagic colitis and severe haemolytic uraemic syndrome. The role of enterohaemolysin (Ehx) in the pathogenesis of O157:H7‐mediated disease in humans remains undefined. Recent studies have revealed the importance of the inflammatory response in O157:H7 pathogenesis in humans. We previously reported that Ehx markedly induced interleukin‐1β (IL‐1β) production in human macrophages. Here, we investigated the disparity in Ehx‐induced IL‐1β production between human and mouse macrophages and explored the underlying mechanism regarding the activation of NOD‐like receptor family, pyrin domain containing 3 (NLRP3) inflammasomes. In contrast to the effects on human differentiated THP‐1 cells and peripheral blood mononuclear cells, Ehx exerted no effect on IL‐1β production in mouse macrophages and splenocytes because of a disparity in pro‐IL‐1β cleavage into mature IL‐1β upon caspase‐1 activation. Additionally, Ehx significantly contributed to O157:H7‐induced ATP release from THP‐1 cells, which was not detected in mouse macrophages. Confocal microscopy demonstrated that Ehx was a key inducer of cathepsin B release in THP‐1 cells but not in mouse IC‐21 cells upon O157:H7 challenge. Inhibitor experiments indicated that O157:H7‐induced IL‐1β production was largely dependent upon caspase‐1 activation and partially dependent upon ATP signalling and cathepsin B release, which were both involved in NLRP3 activation. Moreover, inhibition of K+ efflux drastically diminished O157:H7‐induced IL‐1β production and cytotoxicity. The findings in this study may shed light on whether and how the Ehx contributes to the development of haemolytic uraemic syndrome in human O157:H7 infection.
Which life course model better explains the association between socioeconomic position and periodontal health?
Authors: Shin Bo‐Mi , Ryu Jae‐In , Sheiham Aubrey , Do Loc Giang , Jung Se‐Hwan 
Published: January 2015

AbstractAimTo assess whether the relationship between socioeconomic position (SEP) and periodontal health fitted the Critical Period or the Social Mobility life course models.MethodsA nationally representative sample of 5570 Korean adults from KNHANES IV study. Log‐binomial regression models adjusting for adulthood or childhood socioeconomic (SES) variables was used to assess independent effects of socioeconomic differences for childhood, adulthood and period of transition from child to adult in periodontal health.ResultsIn the Critical Period model, poorer periodontal status was associated with SES disadvantage in adulthood and not predicted by SES disadvantage in childhood. For the intergenerational Social Mobility model, prevalence of current periodontal disease was only different for females aged 30–39 and 40–49 years, after adjustment. Prevalence of periodontal disease in females was highest in the downwardly mobile group.ConclusionsThe Critical Period model was better at explaining association between socioeconomic position and periodontal health, such as the adulthood socioeconomic variables (SEP), had a stronger effect than childhood factors on periodontal disease. The Social Mobility model explained more of the variation in the association between SEP and periodontal health among women than among men.
White matter microstructure and developmental improvement of hyperactive/impulsive symptoms in attention‐deficit/hyperactivity disorder
Authors: Francx Winke , Zwiers Marcel P. , Mennes Maarten , Oosterlaan Jaap , Heslenfeld Dirk , Hoekstra Pieter J. , Hartman Catharina A. , Franke Barbara , Faraone Stephen V. , O'Dwyer Laurence , Buitelaar Jan K. 
Published: January 2015

BackgroundA developmental improvement of symptoms in attention‐deficit/hyperactivity disorder (ADHD) is frequently reported, but the underlying neurobiological substrate has not been identified. The aim of this study was to determine whether white matter microstructure is related to developmental improvement of ADHD symptoms.MethodsA cross‐sectional magnetic resonance imaging (MRI) analysis was embedded in a prospective follow‐up of an adolescent cohort of ADHD and control subjects (NeuroIMAGE). Mean age at baseline was 11.9 years, mean interval of follow‐up was 5.9 years. About 75.3% of the original cohort was retained successfully. Data of 101 participants with ADHD combined type at baseline and 40 healthy controls were analysed. ADHD symptoms were measured with semistructured, investigator‐based interviews and Conners' questionnaires, on the basis of DSM‐IV criteria. Fractional anisotropy (FA) and mean diffusivity (MD) indices of white matter microstructure were measured using whole brain diffusion tensor imaging at follow‐up only. In a dimensional analysis FA and MD were related to change in ADHD symptoms. To link this analysis to DSM‐IV diagnoses, a post hoc categorical group analysis was conducted comparing participants with persistent (n = 59) versus remittent (n = 42) ADHD and controls.ResultsOver time, participants with ADHD showed improvement mainly in hyperactive/impulsive symptoms. This improvement was associated with lower FA and higher MD values in the left corticospinal tract at follow‐up. Findings of the dimensional and the categorical analysis strongly converged. Changes in inattentive symptoms over time were minimal and not related to white matter microstructure.ConclusionsThe corticospinal tract is important in the control of voluntary movements, suggesting the importance of the motor system in the persistence of hyperactive/impulsive symptoms.