bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predator‐ and competitor‐induced responses in amphibian populations that evolved different levels of pesticide tolerance
Authors: Jones Devin K. , Hua Jessica , Mattes Brian M. , Cothran Rickey D. , Hoverman Jason T. , Relyea Rick A. 
Published: February 2021

AbstractExposure to agrochemicals can drive rapid phenotypic and genetic changes in exposed populations. For instance, amphibian populations living far from agriculture (a proxy for agrochemical exposure) exhibit low pesticide tolerance, but they can be induced to possess high tolerance following a sublethal pesticide exposure. In contrast, amphibian populations close to agriculture exhibit high, constitutive tolerance to pesticides. A recent study has demonstrated that induced pesticide tolerance appears to have arisen from plastic responses to predator cues. As a result, we might expect that selection for constitutive pesticide tolerance in populations near agriculture (i.e., genetic assimilation) will lead to the evolution of constitutive responses to natural stressors. Using 15 wood frog (Rana sylvatica) populations from across an agricultural gradient, we conducted an outdoor mesocosm experiment to examine morphological (mass, body length, and tail depth) and behavioral responses (number of tadpoles observed and overall activity) of tadpoles exposed to three stressor environments (no‐stressor, competitors, or predator cues). We discovered widespread differences in tadpole traits among populations and stressor environments, but no population‐by‐environment interaction. Subsequent linear models revealed that population distance to agriculture (DTA) was occasionally correlated with tadpole traits in a given environment and with magnitudes of plasticity, but none of the correlations were significant after Bonferroni adjustment. The magnitudes of predator and competitor plasticity were never correlated with the magnitude of pesticide‐induced plasticity that we documented in a companion study. These results suggest that while predator‐induced plasticity appears to have laid the foundation for the evolution of pesticide‐induced plasticity and its subsequent genetic assimilation, inspection of population‐level differences in plastic responses show that the evolution of pesticide‐induced plasticity has not had a reciprocal effect on the evolved plastic responses to natural stressors.
Estimating predator functional responses using the times between prey captures
Authors: Coblentz Kyle E. , DeLong John P. 
Published: February 2021

AbstractPredator functional responses describe predator feeding rates and are central to predator–prey theory. Ecologists have measured thousands of predator functional responses using the same basic experimental method. However, this design is ill‐suited to address many current questions regarding functional responses. We derive a new experimental design and statistical analysis that quantifies functional responses using the times between a predators’ feeding events requiring only one or a few trials. We examine the feasibility of the experimental method and analysis using simulations to assess the ability of the statistical model to estimate functional response parameters and perform a proof‐of‐concept experiment estimating the functional responses of two individual jumping spiders. Our simulations show that the statistical method reliably estimates functional response parameters. Our proof‐of‐concept experiment illustrates that the method provides reasonable estimates of functional response parameters. By virtue of the fewer number of trials required to measure a functional response, the method derived here promises to expand the questions that can be addressed using functional response experiments and the systems in which they can be measured. Thus, we hope that our method will refine our understanding of functional responses and predator–prey interactions more generally.
Plasticity and selection drive hump‐shaped latitudinal patterns of flowering phenology in an invasive intertidal plant
Authors: Chen Xincong , Liu Wenwen , Pennings Steven C. , Zhang Yihui 
Published: February 2021

AbstractPatterns of flowering phenology can affect the success of plant invasions, especially when introduced species spread across a wide range of latitude into different climatic conditions. We combined a 4‐yr field survey and a 3‐yr common garden experiment with the invasive grassSpartina alterniflorathat is now widespread along the coast of China to document the latitudinal pattern of flowering phenology, determine if phenology was related to climate or oceanographic variables, and determine whether phenology patterns were fixed versus plastic. In the field, first flowering day displayed a hump‐shaped relationship with latitude, with low‐ and high‐latitude plants flowering 100 d and 10 d earlier than plants at middle latitudes, respectively. Peak flowering day showed a similar hump‐shaped relationship with latitude, with the interval between first and peak flowering day decreasing with increasing latitude. First flowering day had a hump‐shaped relationship with annual growing degree days but a linear positive relationship with tidal range. In the common garden, first flowering day decreased linearly with increasing latitude of origin, as did peak flowering day, and the interval between first and peak flowering day increased with increasing latitude. First flowering day in the common garden had weak or no relationships with abiotic variables at the sites of origin. In both the field and common garden, first flowering day was later in site years for which plants were taller. These results indicate a high degree of plasticity in flowering phenology, with plants flowering later in the field at sites with intermediate temperatures and high tide ranges. Common garden results indicate some selection for earlier flowering at sites with low temperatures, consistent with a shorter growing season. Consistent with life‐history theory, plants flowered later under conditions favoring vigorous growth. Earlier flowering and smaller size of plants at high and low latitudes suggests thatS. alterniflorahas already occupied much of the geographic range favorable for it on the East Coast of Asia.
Fatty Acids and Flavor Components in the Oil Extracted from Golden Melon Seeds
Authors: Chen Lihua , Li Dongna , Zhu Chuchu , Ma Xia , Rong Yuzhi 
Published: February 2021

AbstractFor complete utilization of raw materials and edible oil production, the oil from golden melon seeds (GSs) is extracted via the cold‐pressing, hot‐pressing, and ultrasound‐assisted aqueous enzymatic extraction (AEE), and the fatty acid composition, and nutritional value of the extracted GS oils (GSOs) are analyzed. The volatile compounds present in the GSOs are determined using gas chromatography–mass spectrometry. The aroma profiles of different GSO samples are further distinguished by using an electronic nose. A total of 16 fatty acids are identified in the GSO samples, with atherogenic, thrombogenic, and nutritive value indices ranging from 0.142–0.151, 0.366–0.403, and 5.019–5.299, respectively. Moreover, 43 volatile compounds, including esters, hydrocarbons, alcohols, ketones, pyrazines, and aldehydes are identified. The cold‐pressed GSO presents fresh and fruity flavors, while the hot‐pressed GSO presents roasted, nutty, fatty, and fruity flavors, and the GSO obtained via AEE presents fatty and fruity flavors. The acid and peroxide contents of these oil samples are 0.69–079 mg g−1 and 5.17–5.79 mmol kg−1, respectively. The results indicate that the extraction method affects the fatty acid composition, flavor components, and physiochemical properties of the GSO. This study may help promote the development of edible GSO.Practical applications: With high demand for edible oils, it is of great significance to find natural edible oils from different sources. The oil in golden melon seeds is extracted by different methods. Their fatty acid composition and flavor components are analyzed. The GSO extracted via AEE method is rich in fatty acids composition. This work would guide the development of an edible GSO and increase the value of golden melon.
Hydrological and meteorological data from research catchments at the Marcell Experimental Forest, Minnesota, USA
Authors: Sebestyen Stephen D. , Lany Nina K. , Roman Daniel Tyler , Burdick Jacob M. , Kyllander Richard L. , Verry Elon Sandy , Kolka Randall K. 
Published: February 2021

AbstractThe Marcell Experimental Forest (MEF) in northern Minnesota, USA, with hydrological research and monitoring of peatland catchments in a low‐topographic relief landscape, contrasts with the mountainous terrain that typifies most research catchments. Six research catchments were instrumented and hydrological and meteorological monitoring was initiated during 1960. Paired‐catchment studies, which started during 1969, have been used to assess land management and environmental change effects on forests, water availability, and biogeochemistry. Over the decades, the research and collaborations have proliferated to include new monitoring and ecosystem experiments. We provide an overview of available datasets and access information for hydrological and meteorological data. Data on streamflow, water table elevation, precipitation, snow, ground frost, air temperature, soil moisture, upland runoff, and water chemistry are discoverable with associated metadata and are archived through several Web‐based, community repositories. The research programme is ongoing and we anticipate updates on an annual or more frequent basis. Additionally, we aim to release other physical, chemical, and isotopic measurements associated with long‐term catchment monitoring and studies at the MEF.
Spatiotemporal patterns of ENSO‐precipitation relationships in the tropical Andes of southern Peru and Bolivia
Authors: Jonaitis Joseph A. , Perry L. Baker , Soulé Peter T. , Thaxton Christopher , Andrade‐Flores Marcos F. , Vargas Tania Ita , Ticona Laura 
Published: February 2021

AbstractPrecipitation in the outer tropical Andes is highly seasonal, exhibits considerable interannual variability, and is vital for regulating freshwater availability, flooding, glacier mass balance, and droughts. The primary driver of interannual variability is El Niño Southern Oscillation (ENSO), with most investigations reporting that the El Niño (La Niña) results in negative (positive) precipitation anomalies across the region. Recent investigations, however, have identified substantial spatiotemporal differences in ENSO‐precipitation relationships. Motivated by the dissimilarity of these findings, this study examines a carefully selected data set (≥ 90% completeness) of ground‐based precipitation observations from 75 high‐elevation (≥ 2,500 m above sea level) meteorological stations in the tropical Andes of southern Peru and Bolivia for the period 1972–2016. Distinct groups of stations and associated variability in precipitation characteristics (e.g., total seasonal precipitation, wet season onset, and wet season length) are identified. Using no spatial constraints, the K‐Means algorithm optimally grouped stations into five easily identifiable groups. The groups farthest from the Amazon basin had significant negative (positive) precipitation anomalies (p < .05) during El Niño (La Niña), aligning with the traditional view of ENSO‐precipitation relationships while groups closest to the Amazon had opposite relationships. Additionally, though studies have reported delays in the wet season, years characterized by El Niño had an earlier wet season onset in all five groups. These findings may aid in improving seasonal climate prediction and managing water resources, and could allow for improved interpretation of tropical Andean ice cores.
Probabilistic assessment of crop yield loss to drought time‐scales in Xinjiang, China
Authors: Li Huawei , Li Yongping , Huang Guohe , Sun Jie 
Published: February 2021

AbstractFrequent drought events under climate change are endangering food security and sustainable agricultural development. Quantitative assessment of crop yield anomalies under drought conditions is essential for effective water resources management and adaptative drought risk mitigation strategies. In this study, a copula‐based bivariate probabilistic framework model is developed to assess the impacts of drought events on crop yield, where the correlation of crop yield anomalies and standardized precipitation evapotranspiration index (SPEI) at multi‐month lags are quantified. This model has advantages in quantifying the impacts of drought scales on crop yield through the joint probability of the corresponding series. Then, the model is applied to Xinjiang Province in Northwestern China, an arid region with extensive agricultural activities. SPEI and yield anomalies of wheat, maize and cotton during 1984–2015 are firstly identified, and then copula‐based framework is constructed to quantify probabilistic crop yield losses caused by drought events. Finally, crop water amounts and irrigation requirements under different drought severity conditions are compared and analysed. Our findings are: (a) wheat and maize yield anomalies are vulnerable to long drought time‐scales, with exceedance probabilities of required yield anomalies returning to normal are 19.3% for wheat and 21.1% for maize, while cotton is susceptible to short drought time‐scales, with exceedance probability of 42.3% for drought recovery; (b) response of wheat crop yield anomalies to the SPEI at 1‐, 3‐, 6‐ and 12‐month scales is the most sensitive, followed by maize, and cotton is the least; (c) under extreme drought conditions, the probability of cotton yield reduction is lower than that of wheat and maize. Results may enhance our understanding of the impacts of drought scales on crops during the growing season, thus providing general guidance for rational irrigation management of crops and incentives for irrigation to mitigate drought risk, ultimately promoting sustainable agricultural development.
Isomer separation and analysis of amphiphilic polysialogangliosides using reversed‐phase liquid chromatography‐mass spectrometry
Authors: Park Jun Young , Shrestha Sarmila Amatya , Cha Sangwon 
Published: February 2021

AbstractGangliosides are amphiphilic, acidic glycosphingolipids possessing one or more sialic acid residues and several isobaric structural isomers with different abundances and bioactivities. Therefore, the distinction between these isomers is crucial for their proper profiling. Although liquid chromatography–mass spectrometry has been successfully employed for this purpose, the distinction process can still be improved, particularly regarding liquid chromatography. Recently, a reversed‐phase liquid chromatography method that could separate disialoganglioside isomers was reported; however, the distinction of trisialoganglioside isomers using reversed‐phase liquid chromatography has not been demonstrated. Here, we investigated the practicality of a reversed‐phase liquid chromatography with an octadecylsilane column for separating polysialoganglioside isomers and successfully achieved the isomer separation of disialogangliosides and trisialogangliosides for the first time. We also confirmed several crucial factors in the mobile‐phase composition, which affect the differential retention and mass spectral response of the isomers. First, an organic modifier, acetonitrile, exhibited superior selectivity against polysialogangliosides over methanol. Second, ammonium bicarbonate was the best ammonium salt additive among those tested, in terms of the separation efficiency and mass spectral response. Third, as the ammonium salt concentration increased, the negative electrospray ionization response was extensively suppressed, and the retention of gangliosides increased.
Optimisation of microwave‐assisted extraction and functional elucidation of bioactive compounds from Cola nitida pod
Authors: Olalere Olusegun Abayomi , Gan Chee‐Yuen , Akintomiwa Olumide Esan , Adeyi Oladayo , Adeyi Abiola 
Published: February 2021

AbstractIntroductionThe quality characteristics and stability of phenolic by‐products from Cola nitida wastes are critical factors for drug formulation and food nutraceutical applications.ObjectivesIn this study, the effect of electromagnetic‐based microwave‐reflux extraction on the total phenolic content, antioxidant capacity, morphological characteristics, physisorption and chromatographic phenolic profiles were successfully investigated. These physicochemical analyses are often employed in the standardisation of dried herbal and food nutraceutical products.Material and methodsIn this study, the electromagnetic‐based extraction process was optimised using the Box–Behnken design. The oleoresin bio‐products were subsequently characterised to determine the total phenolic content, morphological and microstructural degradation. These analyses were conducted to elucidate the effect of the microwave heating on the C. nitida pod powder.ResultsFrom the predicted response, the optimal percentage yield was achieved at 26.20% under 5.39 min of irradiation time, 440 W microwave power and oven temperature of 55°C. Moreover, the rapid estimation of the phenolic content and antioxidant capacity were recorded at 124.84 ± 0.064 mg gallic acid equivalent (GAE)/g dry weight (d.w.) and 6.93 ± 0.34 μg/mL, respectively. The physicochemical characterisation results from the Fourier‐transform infrared spectroscopy, field emission scanning electron microscopy and physisorption analyses showed remarkable changes in the micro‐surface area (13.66%) characteristics.ConclusionThe recorded optimal conditions established a basis for future scale‐up of microwave extraction parameters with a potential for maximum yield. The physiochemical characterisation revealed the functional characteristics of C. nitida and their tolerance to microwave heating.
Attitudes towards involving children in decision‐making surrounding lung transplantation
Authors: Barsky Emily E. , Berbert Laura M. , Dahlberg Suzanne E. , Truog Robert D. 
Published: February 2021

AbstractBackgroundMedical care has shifted from a paternalistic model towards one centered around patient autonomy and shared decision‐making (SDM), yet the role of the pediatric patient in decision‐making is unclear. Studies suggest that many children with chronic disease are capable of making medical decisions at a young age, yet no standardized approaches have been developed for involving children in these decisions.MethodsThis is a single‐center survey study investigating the attitudes of pediatric pulmonologists towards involvement of children in decisions regarding lung transplantation, utilizing a hypothetical case scenario with systematic manipulation of age and maturity level. We evaluated physician belief regarding ultimate decision‐making authority, reconciliation of parent–child discordance, and utility of ethics and psychiatry consultation services.ResultsThe majority of pediatric pulmonologists at this center believe decision‐making authority rests with the parents. The effects of age and maturity are unclear. In instances of parent–child disagreement, physicians are more likely to try to convince parents to defer to the child if the child is both older and more mature. Physicians are divided on the utility of ethics and psychiatry consultations.ConclusionInvolvement of children with cystic fibrosis in SDM is broadly supported but inconsistently implemented. Despite evidence that children with chronic disease may have decisional capacity at a young age, the majority of physicians still grant decisional authority to parents. There are numerous barriers to involving children in decisions, including legal considerations. The role of age and maturity level in influencing these decisions appears small and warrants further investigation.
New feedback control techniques of quaternion fuzzy neural networks with time‐varying delay
Authors: Aouiti Chaouki , Jallouli Hediene 
Published: February 2021

AbstractThis article addresses the problems of fixed‐time stabilization for a class of quaternion fuzzy neural networks (QFNNs) with time‐varying delay. The QFNNs are developed by dividing our system into four real‐valued parts based on the Hamilton rule. Then, based on fixed‐time stability theory, some inequality techniques, and selecting the appropriate controllers and Lyapunov function, a novel criterion guaranteeing the fixed‐time stabilization and the finite‐time stabilization of the addressed system is derived. Finally, three numerical examples are presented to show the effectiveness of our theoretical results.
Space‐time modeling of child mortality at the Admin‐2 level in a low and middle income countries context
Authors: Godwin Jessica , Wakefield Jon 
Published: February 2021

AbstractThe Sustainable Development Goals call for a total reduction of preventable child mortality before 2030. Further, the goals state the desirability to have subnational mortality estimates. Estimates at this level are required for health interventions at the subnational level. In a low and middle income countries context, the data on mortality typically consist of household surveys, which are carried out with a stratified, cluster design, and census microsamples. Most household surveys collect full birth history (FBH) data on birth and death dates of a mother's children, but censuses collect summary birth history (SBH) data which consist only of the number of children born and the number that died. In previous work, direct (survey‐weighted) estimates with associated variances were derived from FBH data and smoothed in space and time. Unfortunately, the FBH data from household surveys are usually not sufficiently abundant to obtain yearly estimates at the Admin‐2 level (at which interventions are often made). In this paper we describe four extensions to previous work: (i) combining SBH data with FBH data, (ii) modeling on a yearly scale, to combine data on a yearly scale with data at coarser time scales, (iii) adjusting direct estimates in Admin‐2 areas where we do not observe any deaths due to small sample sizes, (iv) acknowledge differences in data sources by modeling potential bias arising from the various data sources. The methods are illustrated using household survey and census data from Kenya and Malawi, to produce mortality estimates from 1980 to the time of the most recent survey, and predictions to 2020.
Corn Starch‐Chitosan Proportion Affects Biodegradable Film Performance for Food Packaging Purposes
Authors: Bof María Julieta , Locaso Delia Elisa , García María Alejandra 
Published: February 2021

AbstractThis work proposes an advance towards the scaling of biodegradable films based on corn starch and chitosan, considering the relevant film properties that condition their use for food packaging and their economic feasibility. The influence of corn starch: chitosan (CS:CH) proportion and chitosan molecular weight used in the formulation is also studied. Chitosan (CH) addition improves film forming dispersions (FFDs) stability stored under refrigerated conditions and enhances the film UV barrier properties and elongation at break, however material costs are higher. Films
with higher starch content exhibited higher elastic modulus and tensile strength. Water vapor barrier, heat‐sealing capacity, and sealing resistance also increase with the corn starch (CS) proportion in film formulation. Taking into consideration the chitosan type used, the polymer‐plasticiser and polymer‐solvent interactions prevail and led to the development of more flexible materials in film formulations with low molecular weight chitosan (LMW‐CH). Meanwhile, polymer‐polymer interactions also became relevant in those obtained with MMW‐CH leading to resistant films. The obtained results indicate that composite films could be used in food packaging design, with those formulated with 75% CS and 25% medium molecular weight chitosan (MMW‐CH) being a good option considering both the film's properties as well as its economical feasibility.