bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fitting functional response surfaces to data: a best practice guide
Authors: Uszko Wojciech , Diehl Sebastian , Wickman Jonas 
Published: April 2020

AbstractDescribing how resource consumption rates depend on resource density, conventionally termed “functional responses,” is crucial to understanding the population dynamics of trophically interacting organisms. Yet, accurately determining the functional response for any given pair of predator and prey remains a challenge. Moreover, functional responses are potentially complex surfaces in multidimensional space, where resource density is only one of several factors determining consumption rates. We explored how three sources of error can be addressed in the design and statistical analysis of functional response experiments: ill‐chosen spacing of prey densities, heteroscedastic variance in consumption rates, and non‐independence of parameters of the function describing prey consumption in relation to prey density and additional environmental factors. We generated extensive, virtual data sets that simulated feeding experiments in which both prey density and environmental temperature were varied, and for which the true, deterministic functional response surface was known and realistic variance had been added. We compared eight different methods of functional response fitting, one of which stood out as best performing. We subsequently tested several conclusions from the simulation study against experimental data of zooplankton feeding on algae across a broad range of temperatures. We summarize our main findings in three best practice guidelines for the experimental estimation of functional response surfaces, of which the second is the most important: (1) space prey densities logarithmically, starting from very low densities; (2) log‐transform prey consumption data prior to fitting; and (3) fit a multivariate functional response surface to all data (including all prey densities and other factors, in our case temperature) in a single step. We also observed that functional response surfaces were fitted more accurately and precisely than their component parameters. The latter occurred because parameter estimates were non‐independent, which is an inevitable feature of fitting complex nonlinear functions to data: A given response surface can often be described with near‐equal accuracy by multiple parameter combinations. We therefore conclude that fitted functional response models perform better at optimizing the fit of the overall response surface than at determining how component parameters, such as the attack rate or handling time, depend on environmental factors such as temperature.
Pollinator declines and the stability of plant–pollinator networks
Authors: Ramos‐Jiliberto Rodrigo , Moisset de Espanés Pablo , Vázquez Diego P. 
Published: April 2020

AbstractPopulation declines of pollinators constitute a major concern for the fate of biodiversity and associated ecosystem services in a context of global change. Massive declines of pollinator populations driven by habitat loss, pollution, and climate change have been reported, whose consequences at community and ecosystem levels remain elusive. We conducted a mathematical modeling and computer simulation study to assess the dynamic consequences of pollinator declines for the biodiversity of plants and pollinators. Specifically, we evaluated the effects of increased mortality and decreased carrying capacity of specialist vs. generalist and effective vs. ineffective pollinators visiting specialist vs. generalist plants on long‐term community biomass and species persistence. Our results reveal that increased larval mortality and increased competition for space among larvae had the greatest impacts on the decline of pollinator diversity. In contrast, the largest sustained decreases in pollinator biomass were driven by increased adult mortality in spite of a small increase in pollinator species persistence. Decreased pollinator diversity led in turn to decreased plant diversity. Attacking pollinators with high degree and connected mostly to low‐degree plants produced the greatest losses of plant diversity. Pollinator effectiveness had no noticeable effect on persistence. Our results illuminate our understanding of the consequences of pollinator declines for the maintenance of biodiversity.
Intra‐ and inter‐annual variation in gray whale body condition on a foraging ground
Authors: Soledade Lemos Leila , Burnett Jonathan D. , Chandler Todd E. , Sumich James L. , Torres Leigh G. 
Published: April 2020

AbstractBaleen whales store energy gained on foraging grounds to support reproduction and other metabolic needs while fasting for long periods during migration. Whale body condition can be used to monitor foraging success, and thus better understand and anticipate individual‐ and population‐level trends in reproduction and survival. We assessed the body condition of eastern North Pacific gray whales (Eschrichtius robustus) on their foraging grounds along the Oregon coast, USA, from June to October of three consecutive years (2016–2018). We used drone photogrammetry and applied the body area index (BAI) to measure and compare whale body condition, which is a continuous, unitless metric similar to the body mass index in humans. A total of 289 drone flights were carried out over 106 photo‐identified whales, which were grouped into demographic units by sex, maturity, and female reproductive status. Calves and pregnant females displayed the highest BAIs, followed by resting females, mature males, and, finally, lactating females, reflecting the significant energetic demands on reproductive females. In all three years, gray whale body condition improved with the progression of feeding seasons, demonstrating the accumulation of body energy reserves on the foraging grounds. Yet, body condition was significantly better in 2016 than in 2017 and 2018 when overall body depletion was observed, indicating a difference in prey availability and/or quality between years. We analyzed local upwelling patterns between 2013 and 2018 as an oceanographic proxy for prey and determined significantly greater upwelling between 2013 and 2015 than low upwelling years between 2016 and 2018. We hypothesize that these upwelling patterns created ecosystem shifts in primary productivity and zooplankton prey of gray whales, causing carry‐over effects between foraging success and body condition in subsequent years. This study demonstrates the value of monitoring whale body condition to better understand temporal variation in foraging success, and potentially detect and describe the causes of anomalous changes in whale population health, such as the 2019 gray whale mortality event.
Magnetic resonance‐based biomarkers in nonalcoholic fatty liver disease and nonalcoholic steatohepatitis
Authors: Caussy Cyrielle , Johansson Lars 
Published: April 2020

AbstractNonalcoholic fatty liver disease is a growing epidemic affecting 30% of the adult population in the Western world. Its progressive form, nonalcoholic steatohepatitis (NASH), is associated with an increased risk of advanced fibrosis, cirrhosis and liver‐related mortality. Therefore, the detection of NAFLD and risk stratification according to the severity of the disease is crucial for the management of patients with NAFLD. Liver biopsy for such risk stratification strategies is limited by its cost and risks; therefore, noninvasive alternatives have been developed. Among noninvasive biomarkers developed in NAFLD, magnetic resonance (MR)‐based biomarkers have emerged as key noninvasive biomarkers in NAFLD with the ability to accurately detect hepatic steatosis and liver fibrosis. The potential utility of MRI for the detection of NASH and functional liver assessment has also recently emerged. In the current review, we will discuss the data supporting the utility of MR‐based biomarker for the detection of features of NAFLD and its potential use in clinical practice and clinical research in NAFLD.
Forecasting the carbon price sequence in the Hubei emissions exchange using a hybrid model based on ensemble empirical mode decomposition
Authors: Wu Qunli , Liu Ziting 
Published: April 2020

AbstractThe prediction of carbon price is exceedingly essential for the regulators, investors, and participants of the carbon trading market. It is the basis for formulating market policies and improving risk management capabilities. China's carbon price series are nonlinear and nonstationary, so it is difficult to predict accurately with traditional models. This paper proposes a multiscale ensemble prediction model based on ensemble empirical mode decomposition (EEMD‐ADD) to improve the prediction accuracy of carbon price. Firstly, EEMD is used to decompose the carbon price sequence into several intrinsic mode functions (IMFs), and these IMFs are divided into high‐frequency component, low‐frequency component and the trend component. Then, LSSVM, PSO‐LSSVM, and BA‐LSSVM are used to predict the three components respectively after comparative analysis. Finally, the results are combined to obtain the final prediction value. In the empirical analysis of the Hubei Emissions Exchange, the proposed model outperforms other comparative models. The RMSE, MAE, and MAPE values of the EEMD‐ADD model are 0.6180, 0.4726, and 1.6342, and the DS, CP, and CD values are 94.36, 92.16, and 96.48. In addition, the model performed best in other time periods. The results suggest that the proposed model is effective and could predict carbon prices more accurately.
Porous aluminosilicates catalysts for low and medium matured shale oil in situ upgrading
Authors: Meng Xianglong , Bian Junjie , Li Jing , Ma Zhongliang , Long Qiulian , Su Jianzheng 
Published: April 2020

AbstractFor medium and low matured shale oil exploration, in situ upgrading could promote the oil recovery. There are two main disadvantages herein, high exploration temperature and large energy consumption. The new approach has been proposed to apply porous aluminosilicate catalysts for shale oil highly efficient upgrading at 350°C, H‐clin and Ni‐clin catalysts were prepared with natural clinoptilolite. Al‐SBA‐15 catalysts were synthesized by following one‐step crystallization procedure, and firstly employed for shale oil in situ upgrading. Kinetic studies of pyrolysis showed that the activation energy of organic matter conversion in shale was reduced from 113.80 kJ mol−1 to 37.28 kJ mol−1. After the catalyst addition, shale oil conversion temperature was declined, the reaction rate was increased, and the energy consumption of in situ upgrading was reduced. In Sinopec patented testing instrument, hydrocarbon generation and hydrocarbon expulsion unit, shale oil catalytic conversion showed increased hydrocarbon generation by 2%‐16%. Under the same reaction conditions, the Al‐SBA‐15 (Si/Al = 5) revealed the best activity for hydrocarbon generation, and the efficiency was elevated to 32.67%, twice as that of thermal conversion. The quality of catalytically produced oil was promoted, by improving the further cracking of bitumen to light oil and gas. The results have a breakthrough significance for intensifying the high‐efficiency hydrocarbon generation and expulsion process of low and medium matured shale oil.
Frequent alternate wetting and drying irrigation mitigates the effect of low phosphorus on rice grain yield in a 4‐year field trial by increasing soil phosphorus release and rice root growth
Authors: Xu Feiyun , Song Tao , Wang Ke , Xu Weifeng , Chen Guanglei , Xu Min , Zhang Qian , Liu Jianping , Zhu Yiyong , Rensing Christopher , Zhang Jianhua , Yuan Wei 
Published: April 2020

AbstractThe nonrenewable nutrient phosphorus (P) has low mobility in soil and is often present in forms that are unavailable to crop plants. Alternate wetting and drying irrigation is one of the widely promoted water‐saving irrigation techniques and can increase mineral nutrient availability; however, its interaction with P in paddy fields remains unclear. We conducted a 4‐year field experiment to determine whether a specific regime of frequent alternate wetting and drying (FAWD15) irrigation and low P usage (P45) had synergistic effects on rice yield, rice growth, water use efficiency (WUE), agronomic P use efficiency (AEp), and soil residual fertilizer P. We found that compared to the continuously flooded (CF) irrigation, FAWD15 irrigation maintained rice yield under low P usage condition in a 4‐year field trial. Our results also showed that under low P usage, FAWD15 resulted in high AEp and WUE, and reduced residual fertilizer P. Further, FAWD15 irrigation increased labile P release and resulted in increased root growth by improving root sucrose distribution. These results suggest that FAWD15 irrigation can mitigate the effect of low P usage on rice grain yield by increasing soil P release and root growth in paddy fields.
Are industry‐level indicators more helpful to forecast industrial stock volatility? Evidence from Chinese manufacturing purchasing managers index
Authors: Wei Yu , Bai Lan , Yang Kun , Wei Guiwu 
Published: April 2020

AbstractEffectively explaining and accurately forecasting industrial stock volatility can provide crucial references to develop investment strategies, prevent market risk and maintain the smooth running of national economy. This paper aims to discuss the roles of industry‐level indicators in industrial stock volatility. Selecting Chinese manufacturing purchasing managers index (PMI) and its five component PMI as the proxies of industry‐level indicators, we analyze the contributions of PMI on industrial stock volatility and further compare the volatility forecasting performances of PMI, macroeconomic fundamentals and economic policy uncertainty (EPU), by constructing the individual and combination GARCH‐MIDAS models. The empirical results manifest that, first, most of the PMI has significant negative effects on industrial stock volatility. Second, PMI which focuses on the industrial sector itself is more helpful to forecast industrial stock volatility compared with the commonly used macroeconomic fundamentals and economic policy uncertainty. Finally, the combination GARCH‐MIDAS approaches based on DMA technique demonstrate more excellent predictive abilities than the individual GARCH‐MIDAS models. Our major conclusions are robust through various robustness checks.
Local Fuel Starvation Degradation of an Automotive PEMFC Full Size Stack
Authors: Obermaier M. , Rauber M. , Bauer A. , Lochner T. , Du F. , Scheu C. 
Published: April 2020

AbstractThe achievement of durability targets is an important challenge for the commercialization of fuel cell electric vehicles (FCEV). In order to meet the requirements, knowledge about the most severe degradation mechanisms of fuel cell stacks under automotive conditions is crucial. In the present work, degradation analysis of an automotive full size stack is performed. Herein, we focus on defects at the cathode catalyst layer and their interrelation including inhomogeneous adhesion of the microporous layer on the catalyst layer, crack formation, cathode catalyst layer thinning and wrinkling of the catalyst coated membrane. In addition, we report linear and circular Pt depositions on top of the cathode catalyst layer, which have to the best of our knowledge not been described in literature yet. For the latter, a degradation mechanism based on liquid water formation, local fuel starvation and current density distribution at the interface between microporous layer and cathode catalyst layer is postulated. Finally, a fast indication for stack degradation is suggested by correlating different degradation phenomena. This improved stack analysis approach allowed us to detect local differences in degradation on both cell and stack level.
Functional differentiation in the human ventromedial frontal lobe: A data‐driven parcellation
Authors: Chase Henry W. , Grace Anthony A. , Fox Peter T. , Phillips Mary L. , Eickhoff Simon B. 
Published: April 2020

AbstractVentromedial regions of the frontal lobe (vmFL) are thought to play a key role in decision‐making and emotional regulation. However, aspects of this area's functional organization, including the presence of a multiple subregions, their functional and anatomical connectivity, and the cross‐species homologies of these subregions with those of other species, remain poorly understood. To address this uncertainty, we employed a two‐stage parcellation of the region to identify six distinct structures within the region on the basis of data‐driven classification of functional connectivity patterns obtained using the meta‐analytic connectivity modeling (MACM) approach. From anterior to posterior, the derived subregions included two lateralized posterior regions, an intermediate posterior region, a dorsal and ventral central region, and a single anterior region. The regions were characterized further by functional connectivity derived using resting‐state fMRI and functional decoding using the Brain Map database. In general, the regions could be differentiated on the basis of different patterns of functional connectivity with canonical “default mode network” regions and/or subcortical regions such as the striatum. Together, the findings suggest the presence of functionally distinct neural structures within vmFL, consistent with data from experimental animals as well prior demonstrations of anatomical differences within the region. Detailed correspondence with the anterior cingulate, medial orbitofrontal cortex, and rostroventral prefrontal cortex, as well as specific animal homologs are discussed. The findings may suggest future directions for resolving potential functional and structural correspondence of subregions within the frontal lobe across behavioral contexts, and across mammalian species.
Hepatitis B Virus DNA Polymerase Restrains Viral Replication Through the CREB1/HOXA Distal Transcript Antisense RNA Homeobox A13 Axis
Authors: Zhao Xiaopei , Fan Hongxia , Chen Xi , Zhao Xiaoqing , Wang Xu , Feng Yujie , Liu Min , Li Shengping , Tang Hua 
Published: April 2020

Background and Aims
Long noncoding RNAs (lncRNAs) have been associated with infection and hepatitis B virus (HBV)‐related diseases, though the underlying mechanisms remain unclear.

Approach and Results
We obtained HBV‐HCC lncRNA profiles by deep sequencing and found HOXA distal transcript antisense RNA (HOTTIP) to be significantly up‐regulated. RT‐qPCR indicated that HOTTIP is highly expressed in HBV‐positive hepatoma tissue and induced by HBV in vitro. Virological experiments showed that HOTTIP significantly suppresses the generation of hepatitis B viral surface antigen, hepatitis B viral e antigen and HBV replication. Homeobox A13 (HOXA13), a downstream factor of HOTTIP, was found to bind to HBV enhancer I and X promotor to repress the production of HBV pregenome RNA (pgRNA) and total RNA as well as HBV replication, suggesting that HOXA13 mediates HOTTIP‐induced suppression of HBV replication. More interestingly, HBV DNA polymerase (DNA pol) binds to and stabilizes cAMP‐responsive element‐binding protein 1 (CREB1) mRNA to facilitate translation of the protein, which, in turn, binds to the regulatory element of HOTTIP to promote its expression.

Conclusions
Our findings demonstrate that HBV DNA pol attenuates HBV replication through activation of the CREB1‐HOTTIP‐HOXA13 axis. These findings shed light on the mechanism by which HBV restrains replication to contribute to persistent infection.
Specific angiogenic peptide binding with injectable cardiac ECM collagen gel promotes the recovery of myocardial infarction in rat
Authors: Feng Manman , Liu Xinyu , Hou Xianglin , Chen Jixuan , Zhang Hong , Song Siqi , Han Xiaohua , Shi Chunying 
Published: April 2020

AbstractRestoring blood supply is an effective way for the therapy of myocardial infarction (MI). It was reported a specific angiogenic peptide (VMP) derived from vascular endothelial growth factor (VEGF) could activate its receptor to mimic the biological activity of VEGF. In this study, in order to improve the local concentration in infarction region, a collagen‐binding domain was synthesized with VMP to construct collagen binding domain (CBD)‐VMP peptides. The fused CBD‐VMP could bind specifically to collagen which was rich in cardiac extracellular matrix (c‐ECM), without impacting the biological activity of VMP peptides. When the CBD‐VMP peptides loaded on collagen scaffold and implanted into the rats subcutaneously, significant vascularization was observed. Then, CBD‐VMP peptides binding with injectable c‐ECM injected into the MI rat by intramuscular administration, significant blood vessels regeneration, and decrease of cell apoptosis were observed, that corelated with the recovery of cardiac function. It might be an alternative promising strategy for the clinical application of MI.
The Effect of Biochemical Remission on Bone Metabolism in Cushing's Syndrome: A 2-Year Follow-Up Study
Authors: Braun Leah T , Fazel Julia , Zopp Stephanie , Benedix Sarina , Osswald-Kopp Andrea , Riester Anna , Rubinstein German , Seidensticker Max , Beuschlein Felix , Drey Michael , Bidlingmaier Martin , Schmidmaier Ralf , Reincke Martin 
Published: April 2020

ABSTRACT
Endogenous Cushing's syndrome (CS) is a rare cause of secondary osteoporosis. The long-term consequences for bone metabolism after successful surgical treatment remain largely unknown. We assessed bone mineral density and fracture rates in 89 patients with confirmed Cushing's syndrome at the time of diagnosis and 2 years after successful tumor resection. We determined five bone turnover markers at the time of diagnosis, 1 and 2 years postoperatively. The bone turnover markers osteocalcin, intact procollagen-IN-propeptide (PINP), alkaline bone phosphatase, CTX-I, and TrAcP 5b were measured in plasma or serum by chemiluminescent immunoassays. For comparison, 71 sex-, age-, and body mass index (BMI)-matched patients in whom Cushing's syndrome had been excluded were studied. None of the patients received specific osteoanabolic treatment. At time of diagnosis, 69% of the patients had low bone mass (mean T-score = −1.4 ± 1.1). Two years after successful surgery, the T-score had improved in 78% of patients (mean T-score 2 years postoperatively −1.0 ± 0.9). The bone formation markers osteocalcin and intact PINP were significantly decreased at time of diagnosis (p ≤ 0.001 and p = 0.03, respectively), and the bone resorption marker CTX-I and TrAcP 5b increased. Postoperatively, the bone formation markers showed a three- to fourfold increase 1 year postoperatively, with a moderate decline thereafter. The bone resorption markers showed a similar but less pronounced course. This study shows that the phase immediately after surgical remission from endogenous CS is characterized by a high rate of bone turnover resulting in a striking net increase in bone mineral density in the majority of patients. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.
Right coronary artery‐coronary sinus fistula diagnosed by three‐dimensional echocardiography
Authors: Li Xiao‐dong , Zhang Yan‐li , Su Qiao‐hui , Wang Xiao‐cong , Xu Hui 
Published: April 2020

AbstractRight coronary artery‐coronary sinus fistula is a very rare congenital anomaly in which a right coronary artery fistula drains into the right atrium, right ventricle, or pulmonary artery. A right coronary artery‐coronary sinus fistula was diagnosed in a 44‐year‐old man by three‐dimensional echocardiography and confirmed by computed tomography angiography and surgery. Relevant published experience in diagnosing this kind of anomaly is summarized.