bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flower traits, habitat, and phylogeny as predictors of pollinator service: a plant community perspective
Authors: Herrera Carlos M. 
Published: December 2019

AbstractPollinator service is essential for successful sexual reproduction and long‐term population persistence of animal‐pollinated plants, and innumerable studies have shown that insufficient service by pollinators results in impaired sexual reproduction (“pollen limitation”). Studies directly addressing the predictors of variation in pollinator service across species or habitats remain comparatively scarce, which limits our understanding of the primary causes of natural variation in pollen limitation. This paper evaluates the importance of pollination‐related features, evolutionary history, and environment as predictors of pollinator service in a large sample of plant species from undisturbed montane habitats in southeastern Spain. Quantitative data on pollinator visitation were obtained for 191 insect‐pollinated species belonging to 142 genera in 43 families, and the predictive values of simple floral traits (perianth type, class of pollinator visitation unit, and visitation unit dry mass), phylogeny, and habitat type were assessed. A total of 24,866 pollinator censuses accounting for 5,414,856 flower‐minutes of observation were conducted on 510 different dates. Flowering patch and single flower visitation probabilities by all pollinators combined were significantly predicted by the combined effects of perianth type (open vs. restricted), class of visitation unit (single flower vs. flower packet), mass of visitation unit, phylogenetic relationships, and habitat type. Pollinator composition at insect order level varied extensively among plant species, largely reflecting the contrasting visitation responses of Coleoptera, Diptera, Hymenoptera, and Lepidoptera to variation in floral traits. Pollinator composition had a strong phylogenetic component, and the distribution of phylogenetic autocorrelation hotspots of visitation rates across the plant phylogeny differed widely among insect orders. Habitat type was a key predictor of pollinator composition, as major insect orders exhibited decoupled variation across habitat types in visitation rates. Comprehensive pollinator sampling of a regional plant community has shown that pollinator visitation and composition can be parsimoniously predicted by a combination of simple floral features, habitat type, and evolutionary history. Ambitious community‐level studies can help to formulate novel hypotheses and questions, shed fresh light on long‐standing controversies in pollination research (e.g., “pollination syndromes”), and identify methodological cautions that should be considered in pollination community studies dealing with small, phylogenetically biased plant species samples.
Transpiration from subarctic deciduous woodlands: Environmental controls and contribution to ecosystem evapotranspiration
Authors: Sabater Ana M. , Ward Helen C. , Hill Timothy C. , Gornall Jemma L. , Wade Thomas J. , Evans Jonathan G. , Prieto‐Blanco Ana , Disney Mathias , Phoenix Gareth K. , Williams Mathew , Huntley Brian , Baxter Robert , Mencuccini Maurizio , Poyatos Rafael 
Published: December 2019

AbstractPotential land–climate feedbacks in subarctic regions, where rapid warming is driving forest expansion into the tundra, may be mediated by differences in transpiration of different plant functional types. Here, we assess the environmental controls of overstorey transpiration and its relevance for ecosystem evapotranspiration in subarctic deciduous woodlands. We measured overstorey transpiration of mountain birch canopies and ecosystem evapotranspiration in two locations in northern Fennoscandia, having dense (Abisko) and sparse (Kevo) overstories. For Kevo, we also upscale chamber‐measured understorey evapotranspiration from shrubs and lichen using a detailed land cover map. Subdaily evaporative fluxes were not affected by soil moisture and showed similar controls by vapour pressure deficit and radiation across sites. At the daily timescale, increases in evaporative demand led to proportionally higher contributions of overstorey transpiration to ecosystem evapotranspiration. For the entire growing season, the overstorey transpired 33% of ecosystem evapotranspiration in Abisko and only 16% in Kevo. At this latter site, the understorey had a higher leaf area index and contributed more to ecosystem evapotranspiration compared with the overstorey birch canopy. In Abisko, growing season evapotranspiration was 27% higher than precipitation, consistent with a gradual soil moisture depletion over the summer. Our results show that overstorey canopy transpiration in subarctic deciduous woodlands is not the dominant evaporative flux. However, given the observed environmental sensitivity of evapotranspiration components, the role of deciduous trees in driving ecosystem evapotranspiration may increase with the predicted increases in tree cover and evaporative demand across subarctic regions.
Facilitation of an invader by a native habitat‐former increases along interacting gradients of environmental stress
Authors: Uyà Marc , Bulleri Fabio , Wright Jeffrey T. , Gribben Paul E. 
Published: December 2019

AbstractNative habitat‐forming species can facilitate invasion by reducing environmental stress or consumer pressure. However, the intensity of one stressor along a local gradient may differ when expanding the scale of observation to encompass major variations in background environmental conditions. In this study, we determined how facilitation of the invasive porcelain crab, Petrolisthes elongatus, by the native tube‐forming serpulid, Galeolaria caespitosa, varied with environmental gradients at local (tidal height) and larger (wave exposure) spatial scales. G. caespitosa constructs a complex calcareous matrix on the underside of intertidal boulders and we predicted that its positive effects on P. elongatus density would increase in intensity with shore height and be stronger at wave‐sheltered than wave‐exposed locations. To test these predictions, we conducted two experiments. First, we determined the effects of serpulid presence (boulders with live or dead serpulid matrix vs. bare boulders) at six shore heights that covered the intertidal distribution of P. elongatus. Second, we determined the effects of serpulid presence (present vs. absent), shore height (high vs. low) and wave exposure (sheltered vs. exposed) on crabs across six locations within the invaded range in northern Tasmania, Australia. In Experiment 1, the presence of serpulids (either dead or alive) enhanced P. elongatus densities at all shore heights, with facilitation intensity (as determined by a relative interaction index; RII) tending to increase with shore height. In Experiment 2, serpulids facilitated P. elongatus across shore heights and wave exposures, although crab densities were lower at high shore levels of wave‐sheltered locations. However, the intensity of crab facilitation by serpulids was greater on wave‐sheltered than on wave‐exposed shores, but only at the high shore level. This study demonstrates that local effects of native habitat‐formers on invasive species are dependent on prevailing environmental conditions at larger spatial scales and that, under more stressful conditions, invaders become increasingly reliant on positive interactions with native habitat‐formers. Increased strength of local‐scale facilitation by native species, dampening broader scale variations in environmental stressors, could enhance the ability of invasive species to establish self‐sustaining populations in the invaded range.
Limits to polycentricity? Institutional layering and policy feedbacks of building energy performance requirements in Sweden
Authors: Smedby Nora 
Published: December 2019

AbstractLocal governments have come to play an increasingly active role in addressing current environmental challenges. In addition to improving the environmental performance of a specific city, such initiatives can potentially spur policy change at other levels of government and thereby contribute to the addressing of global environmental challenges. This type of interplay between local and higher levels of government has been insufficiently addressed by environmental governance research. This study addresses this research gap by looking at the case of regulatory energy performance requirements on buildings in Sweden. Through a case study methodology, the research turns to policy documents and interviews. The research shows how local energy performance requirements on buildings provided tensions that impeded their own longevity but contributed to raising ambitions in national regulation. The research contributes to work on polycentric governance by accounting for the existence of hierarchies through the use of concepts from historical institutionalism. In this regard, the study suggests that governance initiatives are prone to institutional layering that, through policy feedback processes, conditions their impact in terms of reaching overarching policy goals. The research is important as it adds empirical substance to the discussion on the potential and limits of local governments in addressing current environmental challenges.
Sex‐ and age‐related differences in the management and outcomes of chronic heart failure: an analysis of patients from the ESC HFA EORP Heart Failure Long‐Term Registry
Authors: Lainščak Mitja , Milinković Ivan , Polovina Marija , Crespo‐Leiro Marisa G. , Lund Lars H. , Anker Stefan D. , Laroche Cécile , Ferrari Roberto , Coats Andrew J.S. , McDonagh Theresa , Filippatos Gerasimos , Maggioni Aldo P. , Piepoli Massimo F. , Rosano Giuseppe M.C. , Ruschitzka Frank , Simić Dragan , Ašanin Milika , Eicher Jean‐Christophe , Yilmaz Mehmet B. , Seferović Petar M. ,   on behalf of the European Society of Cardiology Heart Failure Long‐Term Registry Investigators Group
Published: December 2019

AbstractAimsThis study aimed to assess age‐ and sex‐related differences in management and 1‐year risk for all‐cause mortality and hospitalization in chronic heart failure (HF) patients.Methods and resultsOf 16 354 patients included in the European Society of Cardiology Heart Failure Long‐Term Registry, 9428 chronic HF patients were analysed [median age: 66 years; 28.5% women; mean left ventricular ejection fraction (LVEF) 37%]. Rates of use of guideline‐directed medical therapy (GDMT) were high (angiotensin‐converting enzyme inhibitors/angiotensin receptor blockers, beta‐blockers and mineralocorticoid receptor antagonists: 85.7%, 88.7% and 58.8%, respectively). Crude GDMT utilization rates were lower in women than in men (all differences: P ≤ 0.001), and GDMT use became lower with ageing in both sexes, at baseline and at 1‐year follow‐up. Sex was not an independent predictor of GDMT prescription; however, age >75 years was a significant predictor of GDMT underutilization. Rates of all‐cause mortality were lower in women than in men (7.1% vs. 8.7%; P = 0.015), as were rates of all‐cause hospitalization (21.9% vs. 27.3%; P < 0.001) and there were no differences in causes of death. All‐cause mortality and all‐cause hospitalization increased with greater age in both sexes. Sex was not an independent predictor of 1‐year all‐cause mortality (restricted to patients with LVEF ≤45%). Mortality risk was significantly lower in patients of younger age, compared to patients aged >75 years.ConclusionsThere was a decline in GDMT use with advanced age in both sexes. Sex was not an independent predictor of GDMT or adverse outcomes. However, age >75 years independently predicted lower GDMT use and higher all‐cause mortality in patients with LVEF ≤45%.
A randomised, double‐blind, placebo‐controlled trial of metformin on myocardial efficiency in insulin‐resistant chronic heart failure patients without diabetes
Authors: Larsen Anders Hostrup , Jessen Niels , Nørrelund Helene , Tolbod Lars Poulsen , Harms Hendrik Johannes , Feddersen Søren , Nielsen Flemming , Brøsen Kim , Hansson Nils Henrik , Frøkiær Jørgen , Poulsen Steen Hvitfeldt , Sörensen Jens , Wiggers Henrik 
Published: December 2019

AbstractAimsThe present study tested the hypothesis that metformin treatment may increase myocardial efficiency (stroke work/myocardial oxygen consumption) in insulin‐resistant patients with heart failure and reduced ejection fraction (HFrEF) without diabetes.Methods and resultsThirty‐six HFrEF patients (ejection fraction 37 ± 8%; median age 66 years) were randomised to metformin (n = 19) or placebo (n = 17) for 3 months in addition to standard heart failure therapy. The primary endpoint was change in myocardial efficiency expressed as the work metabolic index (WMI), assessed by 11C‐acetate positron emission tomography and transthoracic echocardiography. Compared with placebo, metformin treatment (1450 ± 550 mg/day) increased WMI [absolute mean difference, 1.0 mmHg·mL·m‐2·106; 95% confidence interval (CI) 0.1 to 1.8; P = 0.03], equivalent to a 20% relative efficiency increase. Patients with above‐median plasma metformin levels displayed greater WMI increase (25% vs. –4%; P = 0.02). Metformin reduced myocardial oxygen consumption (–1.6 mL O2·100 g‐1·min‐1; P = 0.014). Cardiac stroke work was preserved (–2 J; 95% CI –11 to 7; P = 0.69). Metformin reduced body weight (–2.2 kg; 95% CI –3.6 to –0.8; P = 0.003) and glycated haemoglobin levels (–0.2%; 95% CI –0.3 to 0.0; P = 0.02). Changes in resting and exercise ejection fraction, global longitudinal strain, and exercise capacity did not differ between groups.ConclusionMetformin treatment in non‐diabetic HFrEF patients improved myocardial efficiency by reducing myocardial oxygen consumption. Measurement of circulating metformin levels differentiated responders from non‐responders. These energy‐sparing effects of metformin encourage further large‐scale investigations in heart failure patients without diabetes.
Association between systolic ejection time and outcomes in heart failure by ejection fraction
Authors: Patel Priyesh A. , Ambrosy Andrew P. , Phelan Matthew , Alenezi Fawaz , Chiswell Karen , Van Dyke Melissa K. , Tomfohr Jennifer , Honarpour Narimon , Velazquez Eric J. 
Published: December 2019

AbstractAimsWorsening heart failure (HF) is associated with shorter left ventricular systolic ejection time (SET), but there are limited data describing the relationship between SET and clinical outcomes. Thus, the objective was to describe the association between SET and clinical outcomes in an ambulatory HF population irrespective of ejection fraction (EF).Methods and resultsWe identified ambulatory patients with HF with reduced EF (HFrEF) and HF with preserved EF (HFpEF) who had an outpatient transthoracic echocardiogram performed between August 2008 and July 2010 at a tertiary referral centre. Multivariable logistic regression was used to evaluate the association between SET and 1‐year outcomes. A total of 545 HF patients (171 HFrEF, 374 HFpEF) met eligibility criteria. Compared with HFpEF, HFrEF patients were younger [median age 60 years (25th–75th percentiles 50–69) vs. 64 years (25th–75th percentiles 53–74], with fewer females (30% vs. 56%) and a similar percentage of African Americans (36% vs. 35%). Median (25th–75th percentiles) EF with HFrEF was 30% (25–35%) and with HFpEF was 54% (48–58%). Median SET was shorter (280 ms vs. 315 ms, P < 0.001), median pre‐ejection period was longer (114 ms vs. 89 ms, P < 0.001), and median relaxation time was shorter (78.7 ms vs. 93.3 ms, P < 0.001) among patients with HFrEF vs. HFpEF. Death or HF hospitalization occurred in 26.9% (n = 46) HFrEF and 11.8% (n = 44) HFpEF patients. After adjustment, longer SET was associated with lower odds of the composite of death or HF hospitalization at 1 year among HFrEF but not HFpEF patients.ConclusionLonger SET is independently associated with improved outcomes among HFrEF patients but not HFpEF patients, supporting a potential role for normalizing SET as a therapeutic strategy with systolic dysfunction.
Bone marrow‐derived mesenchymal stromal cell treatment in patients with ischaemic heart failure: final 4‐year follow‐up of the MSC‐HF trial
Authors: Mathiasen Anders B. , Qayyum Abbas A. , Jørgensen Erik , Helqvist Steffen , Kofoed Klaus F. , Haack‐Sørensen Mandana , Ekblond Annette , Kastrup Jens 
Published: December 2019

AbstractAimsThe study assessed 4‐year outcomes of intramyocardial injections of autologous bone marrow‐derived mesenchymal stromal cells (MSCs) in patients with ischaemic heart failure.Methods and resultsThe MSC‐HF trial was a randomized, double‐blind, placebo‐controlled trial. Patients were randomized 2:1 to intramyocardial injections of MSCs or placebo. The primary endpoint was change in left ventricular end‐systolic volume (LVESV), measured by magnetic resonance imaging or computed tomography. Sixty patients aged 30–80 years with ischaemic heart failure, New York Heart Association class II–III, left ventricular ejection fraction (LVEF) <45% and no further treatment options were randomized. Patients were followed clinically for 12 months and in addition 4‐year data of hospitalizations and survival were retrieved. After 12 months, LVESV was significantly reduced in the MSC group and not in the placebo group, with difference between groups of 17.0 ± 16.2 mL (95% confidence interval 8.3–25.7, P = 0.0002). There were also significant improvements in LVEF of 6.2% (P < 0.0001), stroke volume of 16.1 mL (P < 0.0001) and myocardial mass (P = 0.009) between groups. A significant dose–response effect was also observed. Moreover, a significant reduction in the amount of scar tissue and quality of life score in the MSC group but not in the placebo group was observed. After 4 years, there were significantly fewer hospitalizations for angina in the MSC group and otherwise no differences in hospitalizations or survival. No side effects were identified.ConclusionsIntramyocardial injections of autologous bone marrow‐derived MSCs improved myocardial function and myocardial mass in patients with ischaemic heart failure.
Spatiotemporal reconstructions of global CO2‐fluxes using Gaussian Markov random fields
Authors: Dahlén Unn , Lindström Johan , Scholze Marko 
Published: December 2019

AbstractAtmospheric inverse modeling is a method for reconstructing historical fluxes of green‐house gas between land and atmosphere, using observed atmospheric concentrations and an atmospheric tracer transport model. The small number of observed atmospheric concentrations in relation to the number of unknown flux components makes the inverse problem ill‐conditioned, and assumptions on the fluxes are needed to constrain the solution. A common practice is to model the fluxes using latent Gaussian fields with a mean structure based on estimated fluxes from combinations of process modeling (natural fluxes) and statistical bookkeeping (anthropogenic emissions). Here, we reconstruct global CO2 flux fields by modeling fluxes using Gaussian Markov random fields (GMRFs), resulting in a flexible and computational beneficial model with a Matérn‐like spatial covariance and a temporal covariance arriving from an autoregressive model in time domain.In contrast to previous inversions, the flux is defined on a spatially continuous domain, and the traditionally discrete flux representation is replaced by integrated fluxes at the resolution specified by the transport model. This formulation removes aggregation errors in the flux covariance, due to the traditional representation of area integrals by fluxes at discrete points, and provides a model closer resembling real‐life space–time continuous fluxes.
Bayesian spatial extreme value analysis of maximum temperatures in County Dublin, Ireland
Authors: O'Sullivan John , Sweeney Conor , Parnell Andrew C. 
Published: December 2019

SummaryIn this study, we begin a comprehensive characterization of temperature extremes in Ireland for the period 1981–2010. We produce return levels of anomalies of daily maximum temperature extremes for an area over Ireland, for the 30‐year period 1981–2010. We employ extreme value theory (EVT) to model the data using the generalized Pareto distribution (GPD) as part of a three‐level Bayesian hierarchical model. We use predictive processes in order to solve the computationally difficult problem of modeling data over a very dense spatial field. To our knowledge, this is the first study to combine predictive processes and EVT in this manner. The model is fit using Markov chain Monte Carlo algorithms. Posterior parameter estimates and return level surfaces are produced, in addition to specific site analysis at synoptic stations, including Casement Aerodrome and Dublin Airport. Observational data from the period 2011–2018 are included in this site analysis to determine if there is evidence of a change in the observed extremes. An increase in the frequency of extreme anomalies, but not the severity, is observed for this period. We found that the frequency of observed extreme anomalies from 2011 to 2018 at the Casement Aerodrome and Phoenix Park synoptic stations exceed the upper bounds of the credible intervals from the model by 20% and 7%, respectively. Using predictive processes made possible a fourfold increase in the domain considered, while still allowing all data across the grid to be used to inform the posterior distributions.
Investigation of CO2/N2 injection in tight oil reservoirs with confinement effect
Authors: Wu Shouya , Li Zhaomin , Wang Zhuangzhuang , Sarma Hemanta K. , Zhang Chao , Wu Mingxuan 
Published: December 2019

AbstractThis paper investigates the CO2/N2 injection process in tight oil reservoirs considering the confinement effect. To study the microscopic physical mechanisms, the confinement effect is characterized by properties shift and capillarity and introduced into the flash calculation to obtain the phase equilibrium of mixture fluids (tight oil/CO2/N2) in tight porous media. The results indicate that the injected nitrogen gas could effectively maintain the reservoir pressure, while it also weakens the effects of the CO2 injection recovery mechanisms, notably diffusivity and viscosity reduction. In addition, a dual‐pore tight oil reservoir model is set up to investigate the CO2/N2 injection with ultra‐low permeability and hydraulic fracturing. The basic CO2 injection parameters are optimized by the orthogonal method. Based on CO2 injection process, three injection schemes of CO2/N2 injection, which are mixed‐gas injection, CO2‐alternating‐N2 (CAN) injection, and N2‐alternating‐CO2 (NAC) injection, were investigated and a comparative analysis was made for the pressure distribution, CO2 mole fraction distribution, and cumulative oil production. Based on this analysis, the CAN injection process proved to be the best injection scheme. A parametric analysis further suggested that the nitrogen gas injection rate was the most important factor. Besides, the effect of gravity drainage, reservoir permeability, nature fractures, and permeability heterogeneity on the oil production of CAN injection process were also investigated in detail. The results show that tight oil reservoir with better vertical connectivity, poor fracture growth, and higher heterogeneity is more favorable for the CO2/N2 injection process.