bluuebunny/crossref_metadata_2025_split huggingface dataset:
Linking vegetation change, carbon sequestration and biodiversity: insights from island ecosystems in a long‐term natural experiment
Authors: Wardle David A. , Jonsson Micael , Bansal Sheel , Bardgett Richard D. , Gundale Michael J. , Metcalfe Daniel B. 
Published: December 2011

Summary1. Despite recent interest in linkages between above‐ and below‐ground communities and their consequences for ecosystem processes, much remains unknown about their responses to long‐term ecosystem change. We synthesize multiple lines of evidence from a long‐term ‘natural experiment’ to illustrate how ecosystem retrogression (the decline in ecosystem process rates due to long‐term absence of major disturbance) drives vegetation change, and thus above‐ground and below‐ground carbon (C) sequestration, and communities of consumer biota.2. Our study system involves 30 islands in Swedish boreal forest that form a 5000‐year, fire‐driven retrogressive chronosequence. Here, retrogression leads to lower plant productivity and slower decomposition and a community shift from plants with traits associated with resource acquisition to those linked with resource conservation.3. We present consistent evidence that above‐ground ecosystem C sequestration declines, while below‐ground and total C storage increases linearly for at least 5000 years following fire absence. This increase is driven primarily by changes in vegetation characteristics, impairment of decomposer organisms and absence of humus combustion.4. Data from contrasting trophic groups show that during retrogression, biomass or abundance of plants and decomposer biota decreases, while that of above‐ground invertebrates and birds increases, due to different organisms accessing resources via distinct energy channels. Meanwhile, diversity measures of vascular plants and above‐ground (but not below‐ground) consumers respond positively to retrogression.5. We show that taxonomic richness of plants and above‐ground consumers are positively correlated with total ecosystem C storage, suggesting that conserving old‐growth forests simultaneously maximizes biodiversity and C sequestration. However, we find little observational or experimental evidence that plant diversity is a major driver of ecosystem C storage on the islands relative to other biotic and abiotic factors.6. Synthesis.Our study reveals that across contrasting islands differing in exposure to a key extrinsic driver (historical disturbance regime and resulting retrogression), there are coordinated responses of soil fertility, vegetation, consumer communities and ecosystem C sequestration, which all feed back to one another. It also highlights the value of well‐replicated natural experiments for tackling questions about above‐ground–below‐ground linkages over temporal and spatial scales that are otherwise unachievable.
How fundamental plant functional trait relationships scale‐up to trade‐offs and synergies in ecosystem services
Authors: Lavorel Sandra , Grigulis Karl 
Published: December 2011

Summary1. Ecosystem services (ES) lie at the core of the interactions among humans and ecosystems. Fundamental understanding of the ecological mechanisms underlying the simultaneous provision of multiple ES has been lagging behind policy and management needs and stands out as a research priority. In this paper, we focus on interactions between ES resulting from fundamental functional mechanisms.2. Plant diversity contributes significantly to the delivery of ES. Specifically, functional composition strongly determines different ecosystem properties and services. Knowledge on associations and trade‐offs among different plant traits is well established, but the consequences for ecosystem functioning and the resulting ability for ecosystems to provide multiple services have only started to be explored. We present a conceptual framework linking environmental change to changes in ecosystem functioning and to changes in ES through plant traits. We explicitly consider the leaf economics and size axes of plant functional variation, and how their responses to key environmental variables are expected to scale‐up to ecosystem properties and ES.3. The framework was tested using a structural equation modelling formalism to understand the trait‐based mechanisms driving trade‐offs in ES in mountain grasslands. Variations along the leaf economics spectrum (LES) towards more exploitative strategies in response to increasing fertility led to a combined increase in several ES valued by local stakeholders, including agronomic value, cultural value and soil water retention. Surprisingly, and contrary to published hypotheses, soil carbon sequestration in the studied subalpine system did not increase at lower fertility which was associated with more conservative plant strategies. Independent variation in LES and height provided alternative pathways to biomass production.4. Synthesis: A trait‐based framework can support the understanding and aid the management of multiple ES. We recommend testing this framework in a variety of contexts and at larger scales, using additional trait axes such as wood density or seed size.
Metapopulations and metacommunities: combining spatial and temporal perspectives in plant ecology
Authors: Alexander Helen M. , Foster Bryan L. , Ballantyne Ford , Collins Cathy D. , Antonovics Janis , Holt Robert D. 
Published: December 2011

Summary1. Metapopulation and metacommunity theories occupy a central role in ecology, but can be difficult to apply to plants. Challenges include whether seed dispersal is sufficient for population connectivity, the role of seed banks and problems with studying colonization and extinction in long‐lived and clonal plants. Further, populations often do not occupy discrete habitat patches. Despite these difficulties, we present case studies to illustrate explicit integration of spatial and temporal data in plant ecology.2. First, on the population level, we focused on two early successional species that lack discrete habitat patches. Multi‐year data sets taken with a grid approach and simple models permit the analysis of landscape dynamics that reflect regional as well as local processes. Using Silene latifolia, we examined colonization. We found evidence for seed dispersal and connectivity among populations across a large landscape. With Helianthus annuus, a species with seed banks, we determined the degree to which landscape‐level patterns of abundance were predicted by local processes (previous year recruitment at a site plus seed banks) vs. seed dispersal. Local processes dominated dynamics.3. Second, at the community level, we utilized a landscape‐level experiment to examine the influence of environmental gradients and spatial processes (dispersal limitation) on community composition during 18 years of succession. Throughout succession, environmental and spatial factors both contributed significantly to spatial variation in species composition (beta diversity). When connectivity was disrupted, space was the dominant factor underlying beta diversity, and this did not change over time. Across more connected communities, spatial effects diminished over succession as the importance of environmental factors increased, consistent with species‐sorting metacommunity models.4. Synthesis. Metapopulation/metacommunity concepts emphasize the interaction between space and time in ecological processes. Spatial processes, such as long‐distance dispersal, play a crucial role in creating new populations. Temporal processes, including seed banks, may dominate dynamics at both local and regional scales. The relative importance of spatial vs. temporal processes changes as populations persist and communities assemble over time; these patterns may only emerge after many years. Integrating long‐term data with spatial data is thus essential for understanding spatio‐temporal patterns inherent in metapopulation and metacommunity theories.
A general integrative framework for modelling woody biomass production and carbon sequestration rates in forests
Authors: Coomes David A. , Holdaway Robert J. , Kobe Richard K. , Lines Emily R. , Allen Robert B. 
Published: December 2011

Summary1. Forests are an important, yet poorly understood, component of the global carbon cycle. We develop a general integrative framework for modelling the influences of stand age, environmental conditions, climate change and disturbance on woody biomass production and carbon sequestration. We use this framework to explore drivers of carbon cycling in New Zealand mountain beech forests, using a 30‐year sequence of data from 246 permanent inventory plots.2. A series of disturbance events (wind, snow storms, earthquakes and beetle outbreaks) had major effects on carbon fluxes: by killing large trees, they removed significant quantities of carbon from the woody biomass pool, and by creating canopy gaps, they reduced the crown area index (CAI) of stands (i.e. canopy area per unit ground area) and woody biomass production. A patch‐dynamics model, which we parameterized using permanent plot data, predicts that episodic disturbance events can create long‐term (c. 100‐year) oscillations in carbon stocks at the regional scale.3. Productivity declined with stand age, as shown in many other studies, but the effect was hard to detect because of canopy disturbance. Individual trees can increase productivity by adjusting the positioning, nutrient content and angle of leaves within canopies. We show that such optimization is most effective when trees are large and suggest it reduces the impact of water and nutrient limitation in old stands.4. We found no evidence that forests were responding to changing climatic conditions, although strong altitudinal trends in biomass production indicate that global warming could alter carbon fluxes in future.5. Synthesis.Our study emphasizes the critical role of disturbance in driving forest carbon fluxes. Losses of biomass arising from tree death (particularly in older stands) exceeded gains arising from growth for most of the 30‐year study, moving 0.3 Mg C ha−1 year−1from biomass to detritus and atmospheric pools. Large‐scale disturbance events are prevalent in many forests world‐wide, and these events are likely to be a driving factor in determining forest carbon sequestration patterns over the next century.
Helping medical learners recognise and manage unconscious bias toward certain patient groups
Authors: Teal Cayla R , Gill Anne C , Green Alexander R , Crandall Sonia 
Published: December 2011

Medical Education 2012: 46: 80–88Context  For the last 30 years, developments in cognitive sciences have demonstrated that human behaviour, beliefs and attitudes are shaped by automatic and unconscious cognitive processes. Only recently has much attention been paid to how unconscious biases based on certain patient characteristics may: (i) result in behaviour that is preferential toward or against specific patients; (ii) influence treatment decisions, and (iii) adversely influence the patient–doctor relationship. Partly in response to accreditation requirements, medical educators are now exploring how they might help students and residents to develop awareness of their own potential biases and strategies to mitigate them.Methods  In this paper, we briefly review key cognition concepts and describe the limited published literature about educational strategies for addressing unconscious bias.Discussion  We propose a developmental model to illustrate how individuals might move from absolute denial of unconscious bias to the integration of strategies to mitigate its influence on their interactions with patients and offer recommendations to educators and education researchers.
Multilocus coalescent analysis of haemoglobin differentiation between low‐ and high‐altitude populations of crested ducks (Lophonetta specularioides)
Authors: BULGARELLA MARIANA , PETERS JEFFREY L. , KOPUCHIAN CECILIA , VALQUI THOMAS , WILSON ROBERT E. , McCRACKEN KEVIN G. 
Published: December 2011

AbstractHypoxia is a key factor determining survival, and haemoglobins are targets of selection in species native to high‐altitude regions. We studied population genetic structure and evaluated evidence for local adaptation in the crested duck (Lophonetta specularioides). Differentiation, gene flow and time since divergence between highland and lowland populations were assessed for three haemoglobin genes (αA, αD, βA) and compared to seven reference loci (six autosomal introns and mtDNA). Four derived amino acid replacements were found in the globin genes that had elevatedΦSTvalues between the Andean highlands and Patagonian lowlands. A single βA‐globin polymorphism at a site known to influence O2affinity was fixed for different alleles in the two populations, whereas three αA‐ and αD‐globin polymorphisms exhibited high heterozygosity in the highlands but not in the lowlands. Coalescent analyses supported restricted gene flow for haemoglobin alleles and mitochondrial DNA but nonzero gene flow for the introns. Simulating genetic data under a drift–migration model of selective neutrality, the βA‐globin fell outside the 95% confidence limit of simulated data, suggesting that directional selection is maintaining different variants in the contrasting elevational environments, thereby restricting migration of βA‐globin alleles. The αA‐ and αD‐globins, by contrast, did not differ from the simulated values, suggesting that variants in these genes are either selectively neutral, or that the effects of selection could not be differentiated from background levels of population structure and linkage disequilibrium. This study illustrates the combined effects of selection and population history on inferring levels of population divergence for a species distributed across an altitudinal gradient in which selection for hypoxia resistance has likely played an important role.
Patients’ attitudes towards patient involvement in safety interventions: results of two exploratory studies
Authors: Davis Rachel E. , Sevdalis Nick , Pinto Anna , Darzi Ara , Vincent Charles A. 
Published: December 2011

AbstractBackground  In recent years, patient‐focused interventions have been introduced aimed at increasing patient involvement in safety‐related behaviours. However, patients’ attitudes towards these interventions and comfort in participating in the recommended behaviours remain largely unexplored.Objective  To evaluate patients’ attitudes towards a video and leaflet aimed at encouraging patient involvement in safety‐related behaviours.Design  Two exploratory studies employing a within‐subjects mixed‐methods design.Setting  Six hospital wards on an inner‐city London teaching hospital.Participants  Medical and surgical inpatients: 80 patients in study 1 (mean age 55; 69% men) and 80 patients in study 2 (mean age 52; 60% men).Intervention  Patients watched the PINK patient safety video (study 1) or read the National Patient Safety Agency’s ‘Please Ask’ about staying in hospital leaflet (study 2).Main outcome measures  Perceived comfort in participating in safety‐related behaviours; attitudes towards the video or leaflet.Results  Both video and leaflet increased patients’ perceived comfort in engaging in some (but not all) safety‐related behaviours (P < 0.05). In both studies, the majority of patients questioned whether the intervention could help to reduce medical errors in health care. Suggestions on how the video/leaflet could be improved mainly related to content and layout.Conclusion  Video and leaflet could be effective at encouraging patient involvement in some safety‐related behaviours. Further in‐depth research on patients’ attitudes towards different educational materials is required to help inform future policies and interventions in this very important but under‐researched area.
Aicardi–Goutieres syndrome: from patients to genes and beyond
Authors: Chahwan C , Chahwan R 
Published: December 2011

Chahwan C, Chahwan R. Aicardi–Goutieres syndrome: from patients to genes and beyond.Aicardi–Goutières syndrome (AGS) is a hereditary neurodegenerative disorder characterized mainly by early onset progressive encephalopathy, concomitant with an increase in interferon‐α levels in the cerebrospinal fluid. Although it was initially mistaken for intrauterine viral infections, AGS has now been genetically attributed to a lack of adequate processing of cellular nucleic acid debris, which culminates in the perpetual trigger of the innate and acquired immune responses. Although the exact mechanisms governing AGS are not fully understood, significant strides have been recently achieved in better characterizing the disorder and the molecular functions of the five known proteins found mutated in AGS. Studies have now uncovered that AGS is tightly linked with the predisposition to other autoimmune disorders such as familial chilblain lupus and systemic lupus erythematosus. Moreover, at least two of the proteins mutated in AGS, namely TREX1 and SAMHD1, also seem to have antagonistic roles in safeguarding humans from human immunodeficiency virus (HIV) infections. We hereby synthesize the current developments into the greater framework of AGS and suggest that a better understanding of AGS might help usher a better treatment not only for some autoimmune disorders but also possibly for patients suffering from HIV infections, too.
A formula for determining the standard liver volume in children: A special reference for neonates and infants
Authors: Saeki Isamu , Tokunaga Shoji , Matsuura Toshiharu , Hayashida Makoto , Yanagi Yusuke , Taguchi Tomoaki 
Published: December 2011

Saeki I, Tokunaga S, Matsuura T, Hayashida M, Yanagi Y, Taguchi T. A formula for determining the standard liver volume in children: A special reference for neonates and infants.Abstract:  Accurately evaluating the ratio of GV to the SLV (GV/SLV) is important in successful pediatric liver transplantation. However, the formula used to calculate the SLV of children, including neonates and infants, has not yet been established. The aim of the current study was to estimate the SLV of children, including neonates, and to establish an accurate formula. The LV of 100 children (including 7 neonates and 15 infants) were measured using thin slice (3–5 mm) helical CT images. Their BSA was calculated from height and weight. A new formula to estimate the SLV was established as follows: SLV (mL) = 689.9 × BSA (m2) − 24.7. The SLV of children was significantly lower than that in previous reports (p < 0.001). A formula for calculating the SLV of children including neonates was established. This new formula will be useful in pediatric liver transplantation.
Lactate levels predict mortality and need for peritoneal dialysis in children undergoing congenital heart surgery
Authors: MAARSLET L. , MØLLER M. B. , DALL R. , HJORTHOLM K. , RAVN H. 
Published: December 2011

BackgroundThe purpose of this study was to investigate whether an initial post‐operative lactate level is a predictor of mortality, need for peritoneal dialysis (PD), duration of intubation or length of stay (LOS) in the intensive care unit (ICU) in children undergoing cardiac surgery.MethodA retrospective, observational follow‐up study was conducted in 206 children undergoing cardiac surgery from 2006 to 2007. Multivariate logistics regression analyses were performed to determine whether the lactate level was an independent risk factor. The lactate concentration at arrival in the ICU, outcome and risk factors (patient demographics, surgical complexity, duration of cardiopulmonary bypass and inotropic score) were obtained from the electronic patient data management program and medical records.ResultThe median (interquartile range) lactate level was 1.9 mmol/l (1.3–2.7) in children immediately after cardiac surgery and a mortality of 3.9%. Eight percent of the children had a lactate level higher than 4.5 mmol/l. An increased lactate level ≥4.5 mmol/l resulted in an odds ratio (95% confidence intervals) of 8.4 (1.5–46.1) for mortality and an odds ratio of 16.9 (2.7–106.8) for PD after adjusting for Risk Adjustment for Congenital Heart Surgery 1. Because of the low number of deaths, limited confounder analysis was performed. Duration of intubation and LOS in the ICU were not associated with the initial lactate level when adjusting for confounders.ConclusionThe initial post‐operative lactate level was a predictor of mortality and need for PD in children undergoing surgery for congenital heart disease.
Cost of cooperation rules selection for cheats in bacterial metapopulations
Authors: DUMAS Z. , KÜMMERLI R. 
Published: December 2011

AbstractBacteria secrete a large variety of beneficial metabolites into the environment, which can be shared as public goods among producing bacteria, but also be exploited by nonproducing cheats. Here, we focus on cooperative production of iron‐chelating molecules (siderophores) in the bacterium Pseudomonas aeruginosa to study how relevant ecological factors influence selection for cheating. We designed patch‐structured metapopulations that allowed us introducing among‐patch ecological variation. We found that cheating readily evolved in uniform iron‐limited environments. This finding is explained by severe iron limitation demanding high siderophore‐production efforts, which results in high metabolic costs accruing to cooperators, and thereby facilitates the spread of cheats. In contrast, we observed a significant reduction or even negation of selection for cheating in metapopulations where we introduced patches with increased iron availability and/or opportunities to recycle siderophores. These findings are compatible with the view that cheats are less likely to invade in environments that allow bacteria to reduce siderophore‐production efforts, as this lowers the overall metabolic costs accruing to cooperators. Because we increased iron availability and siderophore recycling opportunities moderately, and only in some patches, our findings demonstrate that already‐small local variations in ecological conditions as occurring in nature can significantly affect selection for public‐goods secretion in microbes. In addition, we found that most (84.6%) of the evolved cheats were partially deficient for siderophore production and not loss‐of‐function mutants. Genetic considerations indicate that mutations leading to partial deficiency occur more frequent than mutations leading to loss of function, but also suggest that partially deficient mutants might often be the more competitive cheats.
A new cell line from Spodoptera exigua (Lepidoptera: Noctuidae) and its differentially expressed genes
Authors: Zhang A. , Li X. , Zhang H. , Wang H. , Miao L. , Zhang J. , Qin Q. 
Published: December 2011

AbstractA new cell line, designated IOZCAS‐Spex XI, was established from the pupal ovaries of Spodoptera exigua (Lepidoptera: Noctuidae) in TNM‐FH medium containing 10% foetal bovine serum. The spherical cells were predominant among the various cell types. The population‐doubling time during the logarithmic phase of growth was 81.7 h. It was confirmed that the cell line originated from S. exigua by DAF‐PCR technique. Analysis of susceptibility to baculovirus showed that the new cell line was susceptible to S. exigua nucleopolyhedrovirus (SeNPV), Autographa californica multiple NPV (AcMNPV) and slightly susceptible to S. litura NPV (SpltNPV), while not permissive to Helicoverpa armigera NPV and Hyphantria cunea NPV (HcNPV). Real‐Time PCR analysis was carried out to compare some differentially expressed genes between the cell line and the primary culture. The result showed that marked significant differences were observed in the expression of the genes of SUMO‐1 activating enzyme, BCCIP‐like protein, 10 kDa HSP, CypA, receptor for activated PKC, PDI‐like protein ERp57, ALDH, DEAD box ATP‐dependent RNA helicase‐like protein (P < 0.01), while a significant difference was obtained in the expression of GST gene between the cell line and the primary culture (P < 0.05).