bluuebunny/crossref_metadata_2025_split huggingface dataset:
An achievable rate region and a capacity outer bound for 3‐user Gaussian multiple access channel with feedback
Authors: Boostanpour Jafar , Abed Hodtani Ghosheh 
Published: March 2018

SummaryExtension of the Ozarow capacity theorem for 2‐transmitter Gaussian multiple access channel (MAC) with feedback to the channels with more than 2 transmitters is a widely studied and long standing problem (for example, see the Kramer sum‐capacity region). In this paper, we investigate and analyze this possible extension. Specifically, exploiting a class of Schalkwijk‐Kailath linear feedback codes, we obtain an achievable rate region for 3‐user Gaussian MAC with full feedback and also a capacity outer bound. Then the results are extended for a case where there is no feedback link for one user, and the corresponding achievable rate region and capacity outer bound are computed. Furthermore, the gap between the derived rates and the sum capacity of 3‐user Gaussian MAC with full and partial feedback is computed under special assumptions.
Relax online resource allocation algorithms for D2D communication
Authors: Hossen Md Sakhawat , Hassan Md Yeakub , Hussain Faisal , Choudhury Salimur , Alam Muhammad Mahbub 
Published: March 2018

SummaryMaximizing the system sumrate by sharing the resource blocks among the cellular user equipments and the D2D (device to device) pairs while maintaining the quality of service is an important research question in a D2D communication underlaying cellular networks. The problem can be optimally solved in offline by using the weighted bipartite matching algorithm. However, in long‐term evolution and beyond (4G and 5G) systems, scheduling algorithms should be very efficient where the optimal algorithm is quite complex to implement. Hence, a low complexity algorithm that returns almost the optimal solution can be an alternative to this research problem. In this paper, we propose 2 less complex stable matching–based relax online algorithms those exhibit very close to the optimal solution. Our proposed algorithms deal with fixed number of cellular user equipments and a variable number of D2D pairs those arrive in the system online. Unlike online matching algorithms, we consider that an assignment can be revoked if it improves the objective function (total system sumrate). However, we want to minimize the number of revocation (ie, the number of changes in the assignments) as a large number of changes can be expensive for the networks too. We consider various offline algorithms proposed for the same research problem as relaxed online algorithms. Through extensive simulations, we find that our proposed algorithms outperform all of the algorithms in terms of the number of changes in assignment between 2 successive allocations while maintaining the total system sumrate very close to the optimal algorithm.
Neonicotinoid insecticides negatively affect performance measures of non‐target terrestrial arthropods: a meta‐analysis
Authors: Main Anson R. , Webb Elisabeth B. , Goyne Keith W. , Mengel Doreen 
Published: March 2018

AbstractNeonicotinoid insecticides are currently the fastest‐growing and most widely used insecticide class worldwide. Valued for their versatility in application, these insecticides may cause deleterious effects in a range of non‐target (beneficial) arthropods. However, it remains unclear whether strong patterns exist in terms of their major effects, if broad measures of arthropod performance are negatively affected, or whether different functional groups are equally vulnerable. Here, we present a meta‐analysis of 372 observations from 44 field and laboratory studies that describe neonicotinoid effects on 14 arthropod orders across five broad performance measures: abundance, behavior, condition, reproductive success, and survival. Across studies, neonicotinoids negatively affected all performance metrics evaluated; however, magnitude of the effects varied. Arthropod behavior and survival were the most negatively affected and abundance was the least negatively affected. Effects on arthropod functional groups were inconsistent. Pollinator condition, reproductive success, and survival were significantly lower in neonicotinoid treatments compared to untreated controls; whereas, neonicotinoid effects on detritivores were not significant. Although magnitude of arthropod response to neonicotinoids varied among performance measures and functional groups, we documented a consistent negative relationship between exposure to neonicotinoid insecticides in published studies and beneficial arthropod performance.
Noise Discrimination Method for Partial Discharge Current Focused on Damped Oscillation Waveform
Authors: Torii Hirotaka , Hayase Yuji , Yamashiro Keisuke , Matsumoto Satoshi 
Published: March 2018

SUMMARYOnline partial discharge (PD) measurement is very important for insulation monitoring of high‐voltage equipment. One of the biggest challenges performing online monitoring is discrimination between PD detect signals and external noises. Experimental results using high‐frequency current transformer (CT) sensor show that the current waveforms associated with various PD signals are all damped cosine waveforms, and have unique frequency and decay times of damped oscillation. Therefore, we focused attention on the damped oscillation waveform of the PD current, especially damped cosine waveform having a different number of oscillations. In addition to this, the noise discrimination method using wavelet transform or short‐time Fourier transform is effective. Those noise discriminating processes are applicable to online PD current measurement system.
Nutrient remobilization in tree foliage as affected by soil nutrients and leaf life span
Authors: Achat David Ludovick , Pousse Noémie , Nicolas Manuel , Augusto Laurent 
Published: March 2018

AbstractNutrient remobilization is a key process in nutrient conservation in plants and in nutrient cycling in ecosystems. To predict the productivity of terrestrial ecosystems, we thus need to improve our understanding of the factors that control remobilization. We studied the remobilization rates of several major nutrients (N, P, S, K, Ca, and Mg) in 102 forest ecosystems representing large environmental gradients at the country scale (France). Total amounts or availability of nutrients in soils were correlated with nutrient remobilization: the larger the soil nutrient pool, the lower the remobilization rate (e.g., P remobilization decreased with increasing total or extractable inorganic P in soils). Soil type and soil parent material influenced nutrient remobilization indirectly through their effect on soil nutrients. Nutrient remobilization was also affected by the quality of soil organic matter (C:N and C:P ratios) and K‐Ca‐Mg antagonisms. In addition to soil properties, plant‐related parameters (nutrient concentrations in foliage and leaf life span) and climate variables (e.g., precipitation and actual evapotranspiration) were also correlated with nutrient remobilization. Using multivariate analysis, we found that soil nutrient richness and the life span of the leaf were generally the two most important factors controlling nutrient remobilization. As a whole, the nutrient remobilization rate is regulated by soil nutrients through negative feedback. This general ecological pattern is modulated by ecophysiological constraints of plants, mainly leaf life span or the capability of plants to move Ca through the phloem sap.
Herbivory and eutrophication mediate grassland plant nutrient responses across a global climatic gradient
Authors: Anderson T. Michael , Griffith Daniel M. , Grace James B. , Lind Eric M. , Adler Peter B. , Biederman Lori A. , Blumenthal Dana M. , Daleo Pedro , Firn Jennifer , Hagenah Nicole , Harpole W. Stanley , MacDougall Andrew S. , McCulley Rebecca L. , Prober Suzanne M. , Risch Anita C. , Sankaran Mahesh , Schütz Martin , Seabloom Eric W. , Stevens Carly J. , Sullivan Lauren L. , Wragg Peter D. , Borer Elizabeth T. 
Published: March 2018

AbstractPlant stoichiometry, the relative concentration of elements, is a key regulator of ecosystem functioning and is also being altered by human activities. In this paper we sought to understand the global drivers of plant stoichiometry and compare the relative contribution of climatic vs. anthropogenic effects. We addressed this goal by measuring plant elemental (C, N, P and K) responses to eutrophication and vertebrate herbivore exclusion at eighteen sites on six continents. Across sites, climate and atmospheric N deposition emerged as strong predictors of plot‐level tissue nutrients, mediated by biomass and plant chemistry. Within sites, fertilization increased total plant nutrient pools, but results were contingent on soil fertility and the proportion of grass biomass relative to other functional types. Total plant nutrient pools diverged strongly in response to herbivore exclusion when fertilized; responses were largest in ungrazed plots at low rainfall, whereas herbivore grazing dampened the plant community nutrient responses to fertilization. Our study highlights (1) the importance of climate in determining plant nutrient concentrations mediated through effects on plant biomass, (2) that eutrophication affects grassland nutrient pools via both soil and atmospheric pathways and (3) that interactions among soils, herbivores and eutrophication drive plant nutrient responses at small scales, especially at water‐limited sites.
Intraspecific trait variation and the leaf economics spectrum across resource gradients and levels of organization
Authors: Fajardo Alex , Siefert Andrew 
Published: March 2018

AbstractUnderstanding patterns of functional trait variation across environmental gradients offers an opportunity to increase inference in the mechanistic causes of plant community assembly. The leaf economics spectrum (LES) predicts global tradeoffs in leaf traits and trait‐environment relationships, but few studies have examined whether these predictions hold across different levels of organization, particularly within species. Here, we asked (1) whether the main assumptions of the LES (expected trait relationships and shifts in trait values across resource gradients) hold at the intraspecific level, and (2) how within‐species trait correlations scale up to interspecific or among‐community levels. We worked with leaf traits of saplings of woody species growing across light and soil N and P availability gradients in temperate rainforests of southern Chile. We found that ITV accounted for a large proportion of community‐level variation in leaf traits (e.g., LMA and leaf P) and played an important role in driving community‐level shifts in leaf traits across environmental gradients. Additionally, intraspecific leaf trait relationships were generally consistent with interspecific and community‐level trait relationships and with LES predictions—e.g., a strong negative intraspecific LMA–leaf N correlation—although, most trait relationships varied significantly among species, suggesting idiosyncrasies in the LES at the intraspecific level.
The role of landscape connectivity in resistance, resilience, and recovery of multi‐trophic microarthropod communities
Authors: Shackelford Nancy , Standish Rachel J. , Lindo Zoë , Starzomski Brian M. 
Published: March 2018

AbstractThere is a need to find generalizable mechanisms supporting ecological resilience, resistance, and recovery. One hypothesized mechanism is landscape connectivity, a habitat configuration that allows movement of biotic and abiotic resources between local patches. Whether connectivity increases all or only one of resistance, resilience, and recovery has not been teased apart, however, and has been difficult to test at large scales and for complex trophic webs. Natural microcosms offer a complex system that can be manipulated to test questions at a landscape‐scale relative to the community of study. Here, we test the role of connectivity in altering resistance, resilience, and recovery to a gradient of heating disturbance in moss microcosms. To test across trophic levels, we focused on community composition as our metric of response and applied three connectivity treatments – isolation, connected to an equally disturbed patch, and connected to an undisturbed patch. We found that connectivity between equally disturbed patches boosted resistance of communities to disturbance. Additionally, recovery was linear and rapid in communities connected to undisturbed landscapes, hump shaped when connected to equally disturbed landscapes, and linear but slow in isolated communities. We did not find thresholds on the disturbance gradient at which disturbed communities exhibited zero or increasing dissimilarity to controls through time, so were unable to draw conclusions on the role of connectivity in ecological resilience. Ultimately, isolated communities exhibited increasingly variable composition and slow recovery patterns even in control communities when compared with connected treatments.
Linking tree genetics and stream consumers: isotopic tracers elucidate controls on carbon and nitrogen assimilation
Authors: Compson Zacchaeus G. , Hungate Bruce A. , Whitham Thomas G. , Koch George W. , Dijkstra Paul , Siders Adam C. , Wojtowicz Todd , Jacobs Ryan , Rakestraw David N. , Allred Kiel E. , Sayer Chelsea K. , Marks Jane C. 
Published: March 2018

AbstractLeaf litter provides an important nutrient subsidy to headwater streams, but little is known about how tree genetics influence energy pathways from litter to higher trophic levels. Despite the charge to quantify carbon (C) and nitrogen (N) pathways from decomposing litter, the relationship between litter decomposition and aquatic consumers remains unresolved. We measured litter preference (attachments to litter), C and N assimilation rates, and growth rates of a shredding caddisfly (Hesperophylax magnus, Limnephilidae) in response to leaf litter of different chemical and physical phenotypes using Populus cross types (P. fremontii, P. angustifolia, and F1 hybrids) and genotypes within P. angustifolia. We combined laboratory mesocosm studies using litter from a common garden with a field study using doubly labeled litter (13C and 15N) grown in a greenhouse and incubated in Oak Creek, Arizona, USA. We found that, in the lab, shredders initially chose relatively labile (low lignin and condensed tannin concentrations, rapidly decomposing) cross type litter, but preference changed within 4 d to relatively recalcitrant (high lignin and condensed tannin concentrations, slowly decomposing) litter types. Additionally, in the lab, shredder growth rates were higher on relatively recalcitrant compared to labile cross type litter. Over the course of a three‐week field experiment, shredders also assimilated more C and N from relatively recalcitrant compared to labile cross type litter. Finally, among P. angustifolia genotypes, N assimilation by shredders was positively related to litter lignin and C:N, but negatively related to condensed tannins and decomposition rate. C assimilation was likewise positively related to litter C:N, and also to litter %N. C assimilation was not associated with condensed tannins or lignin. Collectively, these findings suggest that relatively recalcitrant litter of Populus cross types provides more nutritional benefit, in terms of N fluxes and growth, than labile litter, but among P. angustifolia genotypes the specific trait of litter recalcitrance (lignin or tannins) determines effects on C or N assimilation. As shredders provide nutrients and energy to higher trophic levels, the influence of these genetically based plant decomposition pathways on shredder preference and performance may affect community and food web structure.
Site conditions determine a key native plant's contribution to invasion resistance in grasslands
Authors: Hulvey Kristin B. , Teller Brittany J. 
Published: March 2018

AbstractMany plant invasion studies in grasslands suggest that resident plants that share functional traits with invaders can reduce invasion by competing for limiting resources. However, since invasion studies often occur in highly controlled plots or microcosms, it is unclear how heterogeneous site conditions alter competitive interactions under realistic scenarios. To explore how landscape heterogeneity affects biotic resistance provided by competitive resident plants, we conducted a field‐based experiment across four sites in California grasslands. Plots contained naturally occurring populations of nativeHemizonia congesta,but differed in other characteristics, including litter cover, annual grass cover, soil moisture, and species richness. We invaded plots with the functionally similar nonnativeCentaurea solstitalis(yellow starthistle) and, at one site, supplemented one‐half of the established plots with water to test the effects of increasing a limiting resource. As in simplified plots and microcosms, increasingH. congestaabundance reduced starthistle biomass by competing for limited soil moisture, but only in plots with high starthistle germination. We conclude that higher abundances of nativeH. congestacan reduce starthistle invasion in heterogeneous grasslands, but competition is also affected by both abiotic (soil moisture) and biotic (starthistle germination number) conditions that vary across sites.
River food webs: an integrative approach to bottom‐up flow webs, top‐down impact webs, and trophic position
Authors: Benke Arthur C. 
Published: March 2018

AbstractThe majority of food web studies are based on connectivity, top‐down impacts, bottom‐up flows, or trophic position (TP), and ecologists have argued for decades which is best. Rarely have any two been considered simultaneously. The present study uses a procedure that integrates the last three approaches based on taxon‐specific secondary production and gut analyses. Ingestion flows are quantified to create a flow web and the same data are used to quantify TP for all taxa. An individual predator's impacts also are estimated using the ratio of its ingestion (I) of each prey to prey production (P) to create an I/P web. This procedure was applied to 41 invertebrate taxa inhabiting submerged woody habitat in a southeastern U.S. river. A complex flow web starting with five basal food resources had 462 flows >1 mg·m−2·yr−1, providing far more information than a connectivity web. Total flows from basal resources to primary consumers/omnivores were dominated by allochthonous amorphous detritus and ranged from 1 to >50,000 mg·m−2·yr−1. Most predator–prey flows were much lower (<50 mg·m−2·yr−1), but some were >1,000 mg·m−2·yr−1. The I/P web showed that 83% of individual predator impacts were weak (<10%), whereas total predator impacts were often strong (e.g., 35% of prey sustained an impact >90%). Quantitative estimates of TP ranged from 2 to 3.7, contrasting sharply with seven integer‐based trophic levels based on longest feeding chain. Traditional omnivores (TP = 2.4–2.9) played an important role by consuming more prey and exerting higher impacts on primary consumers than strict predators (TP ≥ 3). This study illustrates how simultaneous quantification of flow pathways, predator impacts, and TP together provide an integrated characterization of natural food webs.
ForC: a global database of forest carbon stocks and fluxes
Authors: Anderson‐Teixeira Kristina J. , Wang Maria M. H. , McGarvey Jennifer C. , Herrmann Valentine , Tepley Alan J. , Bond‐Lamberty Ben , LeBauer David S. 
Published: March 2018

AbstractForests play an influential role in the global carbon (C) cycle, storing roughly half of terrestrial C and annually exchanging with the atmosphere more than five times the carbon dioxide (CO2) emitted by anthropogenic activities. Yet, scaling up from field‐based measurements of forest C stocks and fluxes to understand global scale C cycling and its climate sensitivity remains an important challenge. Tens of thousands of forest C measurements have been made, but these data have yet to be integrated into a single database that makes them accessible for integrated analyses. Here we present an open‐access global Forest Carbon database (ForC) containing previously published records of field‐based measurements of ecosystem‐level C stocks and annual fluxes, along with disturbance history and methodological information. ForC expands upon the previously published tropical portion of this database, TropForC (https://doi.org/10.5061/dryad.t516f), now including 17,367 records (previously 3,568) representing 2,731 plots (previously 845) in 826 geographically distinct areas. The database covers all forested biogeographic and climate zones, represents forest stands of all ages, and currently includes data collected between 1934 and 2015. We expect that ForC will prove useful for macroecological analyses of forest C cycling, for evaluation of model predictions or remote sensing products, for quantifying the contribution of forests to the global C cycle, and for supporting international efforts to inventory forest carbon and greenhouse gas exchange. A dynamic version of ForC is maintained at on GitHub (https://GitHub.com/forc-db), and we encourage the research community to collaborate in updating, correcting, expanding, and utilizing this database. ForC is an open access database, and we encourage use of the data for scientific research and education purposes. Data may not be used for commercial purposes without written permission of the database PI. Any publications using ForC data should cite this publication and Anderson‐Teixeira et al. (2016a) (see Metadata S1). No other copyright or cost restrictions are associated with the use of this data set.
Prevalence, clinical correlates, and outcomes of anaemia in multi‐ethnic Asian patients with heart failure with reduced ejection fraction
Authors: Goh Vera J. , Tromp Jasper , Teng Tiew‐Hwa K. , Tay Wan Ting , Van Der Meer Peter , Ling Lieng Hsi , Siswanto Bambang B. , Hung Chung‐Lieh , Shimizu Wataru , Zhang Shu , Narasimhan Calambur , Yu Cheuk Man , Park Sang Weon , Ngarmukos Tachapong , Liew Houng Bang , Reyes Eugenio , Yap Jonathan , MacDonald Michael , Richards Mark A. , Anand Inder , Lam Carolyn S.P. ,   on behalf of the ASIAN‐HF investigators
Published: March 2018

AbstractAimsRecent international heart failure (HF) guidelines recognize anaemia as an important comorbidity contributing to poor outcomes in HF, based on data mainly from Western populations. We sought to determine the prevalence, clinical correlates, and prognostic impact of anaemia in patients with HF with reduced ejection fraction across Asia.Methods and resultsWe prospectively studied 3886 Asian patients (60 ± 13 years, 21% women) with HF (ejection fraction ≤40%) from 11 regions in the Asian Sudden Cardiac Death in Heart Failure study. Anaemia was defined as haemoglobin <13 g/dL (men) and <12 g/dL (women). Ethnic groups included Chinese (33.0%), Indian (26.2%), Malay (15.1%), Japanese/Korean (20.2%), and others (5.6%). Overall, anaemia was present in 41%, with a wide range across ethnicities (33–54%). Indian ethnicity, older age, diabetes, and chronic kidney disease were independently associated with higher odds of anaemia (all P < 0.001). Ethnicity modified the association of chronic kidney disease with anaemia (Pinteraction = 0.045), with the highest adjusted odds among Japanese/Koreans [2.86; 95% confidence interval (CI) 1.96–4.20]. Anaemic patients had lower Kansas City Cardiomyopathy Questionnaire scores (P < 0.001) and higher risk of all‐cause mortality and HF hospitalization at 1 year (hazard ratio = 1.28, 95% CI 1.08–1.50) compared with non‐anaemic patients. The prognostic impact of anaemia was modified by ethnicity (Pinteraction = 0.02), with the greatest hazard ratio in Japanese/Koreans (1.82; 95% CI 1.14–2.91).ConclusionsAnaemia is present in a third to more than half of Asian patients with HF and adversely impacts quality of life and survival. Ethnic differences exist wherein prevalence is highest among Indians, and survival is most severely impacted by anaemia in Japanese/Koreans.