bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluating Sierra Nevada Yellow‐Legged Frog Distribution Using Environmental DNA
Authors: Bedwell Mallory E. , Hopkins Kristina V. S. , Dillingham Colin , Goldberg Caren S. 
Published: May 2021

ABSTRACTGenetic tools that identify species from trace DNA samples could supplement traditional survey methods to clarify distributional limits of rare species. For species with legal habitat protection, elevational limits of distributions are used to determine where management actions may affect endangered species. The endangered Sierra Nevada yellow‐legged frog (Rana sierrae) generally is found down to 1,370 m, but in the Plumas National Forest, California, USA, there are a number of historical records below this elevation, resulting in protections extending to 1,067 m. This species is phenotypically similar to the foothill yellow‐legged frog (R. boylii), with which it occasionally hybridizes. We used a combination of genetic methods to investigate the fine‐scale distribution of the Sierra Nevada yellow‐legged frog in the Plumas National Forest. We collected and analyzed environmental DNA (eDNA) samples from all accessible lower elevation sites with records of Sierra Nevada yellow‐legged frog (n = 17) and swabbed 220 individuals for genetic identification from 2016–2018 to clarify the distribution of this endangered species. We created a climatic suitability model using the validated Sierra Nevada yellow‐legged frog records and current (1970–2000) climate models to assess additional highly suitable localities for Sierra Nevada yellow‐legged frog presence using eDNA capture. We did not confirm detection of Sierra Nevada yellow‐legged frog eDNA at any historical sites and identified all swabbed individuals from below 1,370 m (n = 144) as foothill yellow‐legged frogs. We located a new Sierra Nevada yellow‐legged frog site (at 1,919 m) during surveys guided by the climatic suitability model. It does not appear after extensive eDNA and genetic sampling that the Sierra Nevada yellow‐legged frog occurs below 1,370 m in this portion of their range at present. Our results show that eDNA sampling can be used as an effective management tool to evaluate historical locations and previously unknown suitable localities for current presence of a species of interest. © 2021 The Authors. The Journal of Wildlife Management published by Wiley Periodicals LLC on behalf of The Wildlife Society.
Effect of livestock manure on soil microbial and nutrient dynamics in zaï cropping systems of the Sahel
Authors: Traoré Salifou , Ouédraogo Pauline , Bayen Philippe , Bationo Babou André , Lee Nathan , Lorenz Nicola , Dick Richard P. 
Published: May 2021

AbstractThe zaï cropping system that involves precision manure placement in small excavated soil pits is designed to restore the productivity of encrusted and degraded soils of the Sahel. However, there is little information on the effectiveness of zaï cropping to improve soil quality, particularly as to how it relates to manure sources. Therefore, our objective was to determine the effect of manure type on plant nutrient availability and soil microbial activity in relation to crop productivity. The experiment had a randomized block design with the following treatments with all manure amendments applied at 6 Mg ha−1: 1) sheep (Ovis aries), 2) goats (Capra hircus), and 3) cattle (Bos indicus) manures; 4) an equal mix of all three manures; and 5) a control with no manure amendment ‐ after which sorghum (Sorghum bicolor [L.] Moench) was planted. Soil samples (0–20 cm) were taken from zaï pits at the sorghum boot stage and analyzed for a suite of plant‐available nutrients, microbial composition, and enzyme activities. The results showed that the zaï system with manure amendments significantly increased soil pH, plant‐available nitrogen by three‐fold, and phosphorus by two‐fold over the control. Goat or mixed manure amended soils had significantly higher enzyme activities than sheep or cattle manure. Manure type also shifted the EL‐FAME biomarkers for bacteria, fungi, and protozoa indicating a more favorable copiotrophic environment in manure amended soils. zaï cropping systems amended with the higher quality or the mixed manure had greater microbial responses, nutrient availability, and crop productivity than the lower quality manure.
Long‐term monitoring and evaluation of land development in a reclamation area under rapid urbanization: A case‐study in Qiantang New District, China
Authors: Hu Tangao , Fan Jinjin , Hou Hao , Li Yao , Li Yue , Huang Kangning 
Published: May 2021

AbstractLand reclamation has occurred extensively worldwide to accommodate urbanization and economic development, especially in developing countries like China. However, we have a limited understanding of the long‐term dynamics and key drivers of land use/cover change in the reclaimed area. In this study, we monitored the detailed spatiotemporal evolution of land reclamation from 1973 to 2018 in Qiantang New District using time‐series LANDSAT and SENTINEL‐2A images and then compared the differences of landscape changes between reclaimed, which are the new‐built land from Qiantang River, and inland areas. Key findings include: (1) A significant decreasing trend for areas near the Qiantang River along the coastline (212.21 to 80.99 km2) and an increasing trend for constructed land (10.05 to 120.89 km2) from 1973 to 2018 was detected; (2) The development modes of the inland area and reclaimed area were significantly different. Development in the inland area was similar to other Chinese cities, whereas the reclaimed area was relatively complex with two main changing paths; and (3) Year 2008 was an important turning point in the perspective of urbanization in the study area. Before 2008, urbanization was random and uncontrolled. After 2008, new governance on land appeared and changed the landscape into a compact and uniform pattern. The proposed framework should reveal the detailed trajectory of land reclamation in small areas and provide insights and tools for better understanding the impact of human activities on the landscape pattern in coastal regions under rapid urbanization.
High irradiation and low discharge promote the dominant role of phytoplankton in riverine nutrient dynamics
Authors: Kamjunke Norbert , Rode Michael , Baborowski Martina , Kunz Julia Vanessa , Zehner Jakob , Borchardt Dietrich , Weitere Markus 
Published: May 2021

AbstractRivers play a relevant role in the nutrient turnover during the transport from land to ocean. Here, highly dynamic planktonic processes are more important compared to streams making it necessary to link the dynamics of nutrient turnover to control mechanisms of phytoplankton. We investigated the basic conditions leading to high phytoplankton biomass and corresponding nutrient dynamics in eutrophic, 8th order River Elbe (Germany). In a first step, we performed six Lagrangian sampling campaigns in the lower river section at different hydrological conditions. While nutrient concentrations remained high at low algal densities in autumn and at moderate discharge in summer, high algal concentrations occurred at low discharge in summer. Under these conditions, concentrations of silica and nitrate decreased and rates of nitrate assimilation were high. Soluble reactive phosphorus was depleted and particulate phosphorus increased inversely. Rising molar C:P ratios of seston indicated a phosphorus limitation of phytoplankton, so far rarely observed in eutrophic large rivers. Global radiation combined with mixing depth had a strong predictive power to explain maximum chlorophyll concentration. In a second step, we estimated nutrient turnover exemplarily for N during the campaign with the lowest discharge based on mass balances and metabolism‐based process measurements. Mass balance calculations revealed a total nitrate uptake of 423 mg N m−2d−1. Increasing phytoplankton density dominantly explained whole river gross primary production and related assimilatory nutrient uptake. In conclusion, riverine nutrient uptake strongly depends on the growth conditions for phytoplankton, which are favored at high irradiation and low discharge.
Unexpected shift from phytoplankton to periphyton in eutrophic streams due to wastewater influx
Authors: Bergbusch Nathanael T. , Hayes Nicole M. , Simpson Gavin L. , Leavitt Peter R. 
Published: May 2021

AbstractPollution with nitrogen (N) and phosphorous (P) impairs streams by favoring suspended algae and cyanobacteria over diatom‐rich periphyton. Recently, wastewater treatment plants have been upgraded to biological nutrient removal to eliminate both P and N (mainly NH4+), although little is known of the effects of this effluent on flowing waters. Here, we used high performance liquid chromatography to quantify how the abundance and composition of phytoplankton and periphyton varied in response to both influx of effluent produced by biological nutrient removal and physico‐chemical conditions in small, turbid, P‐rich streams of the northern Great Plains. At the catchment scale, analysis with generalized additive models (GAMs) explained 40.5–62.6% of deviance in total phototroph abundance (as Chl a) and 72.5–82.5% of deviance in community composition (as biomarker carotenoids) in both planktonic and benthic habitats when date‐ and site‐specific physico‐chemical parameters were used as predictors. In contrast, GAMs using wastewater input (as aqueous δ15N) as a predictor explained up to 50% of deviance in Chl a, and ~60% of deviance in community composition, in both suspended (51.6% of Chl a, 67.1% of composition) and attached communities (21.5% of Chl a, 58.8% of composition). Phytoplankton was replaced by periphyton within a 60‐km wastewater‐impacted reach due to dilution of streams by transparent effluent and addition of urban NO3−, although predominance of phytoplankton was re‐established after confluence with higher‐order streams. Overall, influx of effluent shifted turbid, phytoplankton‐rich streams to clear ecosystems with abundant epilithon by improving water transparency and providing NO3− to favor benthic diatoms and chlorophytes.
Complexities of disturbance response in a marine food web
Authors: Lewis Kristy A. , Christian Robert R. , Martin Charles W. , Allen Kira L. , McDonald Ashley M. , Roberts Victoria M. , Shaffer Michelle N. , Valentine John F. 
Published: May 2021

ABSTRACTA primary aspect of applied marine ecology assesses how food webs change in response to ecosystem disturbances. In 2010, the drilling rig Deepwater Horizon (DWH) discharged ~3.19 million barrels of crude oil into the northern Gulf of Mexico. The spill, followed by widespread dispersant application to enhance oil degradation, represented a significant anthropogenic disturbance in the region. We created network models of four multi‐year periods, to represent the acute and chronic food web responses to the DWH spill. Using ecological network analysis (ENA) and information theory, we compared multiple food web metrics among these periods in the context of food web resilience theory. This analysis was conducted at three levels of hierarchical organization: whole ecosystem, nekton community, and individual nekton taxa. We analyzed how individual taxa contribute to resilience of the food web with a novel informational index: Redundancy/Ascendency. Apparent responses to the disturbance differed across hierarchical levels. Some metrics dependent on biomass change and flow distribution temporarily increased during the years immediately following the discharge and subsequently returned to pre‐DWH levels. Metrics of energy flow linked to primary production rose in the last two periods, perhaps reflecting eutrophication. Other metrics changed little or had no obviously explainable patterns. Overall, our results indicate the nektonic food web in this region is flexible to disturbance and likely has redundant energy pathways explaining the reported ecosystem resilience to the DWH spill. We show that an ENA, when applied to multiple levels of ecosystem hierarchy, may aid understanding of marine food web resilience.
Pulmonary Vascular Resistance Predicts Mortality and Graft Failure in Transplantation Patients With Portopulmonary Hypertension
Authors: Jose Arun , Shah Shimul A. , Anwar Nadeem , Jones Courtney R. , Sherman Kenneth E. , Elwing Jean M. 
Published: May 2021

Portopulmonary hypertension (POPH) is a pulmonary vascular disease associated with significant morbidity and mortality in those with liver disease, conferring a higher mortality in patients awaiting liver transplantation (LT). Although not a transplant indication, patients with POPH can experience significant clinical improvement following LT, and those maintaining a mean pulmonary artery pressure (MPAP) <35mm Hg and a pulmonary vascular resistance (PVR) <5 Woods units (WU) are granted additional listing points to expedite LT. The effect of POPH on posttransplant outcomes such as mortality and graft failure, however, is not well defined. We performed a retrospective cohort study of the US Organ Procurement and Transplantation Network database of all adult patients who underwent LT between January 1, 2006, and December 1, 2020. Using adjusted accelerated failure time models, we examined the relationship between a diagnosis of POPH and outcomes following LT and the relationship between pre‐LT hemodynamics and post‐LT survival (alive with a functioning graft) in patients with POPH. Compared with those undergoing transplants without exception points, patients with POPH had comparable post‐LT survival rates but were significantly more likely to have graft failure. Both pre‐LT MPAP and PVR predicted post‐LT survival in POPH, with a pre‐LT PVR of ≥1.6 WU, more than doubling the hazard for mortality (death or a nonfunctioning graft; coefficient, 2.01; standard error, 0.85; hazard ratio, 2.21; P = 0.02). POPH may confer a significantly higher risk of post‐LT graft failure compared with patients with cirrhosis without POPH, and a pre‐LT PVR of ≥1.6 WU may predict post‐LT survival. Further investigation into the relationship between pre‐LT hemodynamics, right ventricular function, and post‐LT outcomes of mortality and graft failure in POPH is needed.
When do you trust AI? The effect of number presentation detail on consumer trust and acceptance of AI recommendations
Authors: Kim Jungkeun , Giroux Marilyn , Lee Jacob C. 
Published: May 2021

AbstractWhen do consumers trust artificial intelligence (AI)? With the rapid adoption of AI technology in the field of marketing, it is crucial to understand how consumer adoption of the information generated by AI can be improved. This study explores a novel relationship between number presentation details associated with AI and consumers' behavioral and evaluative responses toward AI. We theorized that consumer trust would mediate the preciseness effect on consumer judgment and evaluation of the information provided by AI. The results of five studies demonstrated that the use of a precise (vs. imprecise) information format leads to higher evaluations and behavioral intentions. We also show mediational evidence indicating that the effect of number preciseness is mediated by consumer trust (Studies 2, 4, and 5). We further show that the preciseness effect is moderated by the accuracy of AI‐generated information (Study 3) and the objective product quality of the recommended products (Study 4). This study provides theoretical implications to the AI acceptance literature, the information processing literature, the consumer trust literature, and the decision‐making literature. Moreover, this study makes practical implications for marketers of AI businesses including those who strategically use AI‐generated information.
Molcular Weight Distribution in Di Metal Cyanide Catalyzed Polymerization 1: Fundamental Distribution for Length Dependent Propagation Constant and Segments
Authors: Bachmann Rolf , Klinger Marcel , Jupke Andreas 
Published: May 2021

AbstractDi metal cyanide (DMC) catalyzed living polymerization is characterized by a) the “catch‐up” kinetics with a length dependent propagation rate constant (n: chain length), favoring the growth of small molecules and b) segmental growth caused by the repeated attachment and detachment of a growing end to a catalyst site. Whereas the inverse square law reduces polydispersity, growth in segments increases it. Analytic expressions of “catch‐up” molecular weight distributions (MWD) are given for , and . To include segments, the theory originally developed for quasi living polymerizations is generalized to arbitrary distributions for the number of segments as well as the MWD of the segments themselves. General simple relationships allow calculating the moments of composite distributions in terms of the moments of the underlying distributions.
Response of surface ozone concentration to emission reduction and meteorology during the COVID‐19 lockdown in Europe
Authors: Deroubaix Adrien , Brasseur Guy , Gaubert Benjamin , Labuhn Inga , Menut Laurent , Siour Guillaume , Tuccella Paolo 
Published: May 2021

AbstractThe lockdown period (March–May 2020) during the COVID‐19 pandemic in Europe led to a reduction in the anthropogenic emissions of primary pollutants. For three‐quarters of over 1,100 available monitoring stations, the average nitrogen dioxide (NO2) concentrations decreased by at least 2.7 μg·m−3 (or 25%) compared with the average concentrations recorded during the same period of the previous seven years. This reduction was not specific to urban or rural areas because the relative reduction was of similar magnitude in both areas. The ozone (O3) response differed spatially, with positive anomalies in Northern Europe and negative anomalies in Southwestern Europe. Reduced cloudiness and related enhanced radiation in Northern Europe played a significant role in the increase of surface O3 concentrations by shifting the photochemical partitioning between NO2 and O3 toward more O3. The level of total oxidant (Ox = O3 + NO2) remained unchanged, except in Southwestern Europe where it decreased. Several episodes lasting a few days of a high level of total oxidants were observed in Northern Europe. The results illustrate the complexity of the atmospheric response to the unprecedented reduction in the emission of primary pollutants.
Substrate‐Driven Differences in Tryptophan Catabolism by Gut Microbiota and Aryl Hydrocarbon Receptor Activation
Authors: Huang Zhan , Schoones Tessa , Wells Jerry M. , Fogliano Vincenzo , Capuano Edoardo 
Published: May 2021

ScopeThis study aims to investigate the effect of tryptophan sources on tryptophan catabolism by gut microbiota and the aryl hydrocarbon receptor (AhR) activation.Methods and ResultsFour substrates (free tryptophan, soybean protein, single and clustered soybean cells) containing an equimolar amount of tryptophan, but with a different bioaccessibility are studied using in vitro batch fermentation. Tryptophan catabolites are identified by LC‐MS/MS. AhR activity is measured by HepG2‐Lucia AhR reporter cells. The total amount of tryptophan‐derived catabolites increases with decreasing level of substrate complexity. Indole is the major catabolite produced from tryptophan and it is the most abundant in the free tryptophan fermentation. Indole‐3‐acetic acid and indole‐3‐aldehyde are abundantly generated in the soybean protein fermentation. The soybean cell fermentation produced high concentrations of tryptamine. Interestingly, large amounts of short‐chain fatty acids (SCFAs) are also found in the soybean cell and protein fermentation. Both tryptophan‐derived catabolites and SCFAs are able to increase AhR reporter activity over time in all four groups.ConclusionThis study illustrates that bacterial catabolism of tryptophan and resulting AhR activation in the gut is modulated by the food matrix, suggesting a role for food design to improve gut health.
Potential Mechanisms of Improved Activity of Natural Killer Cells Induced by the Consumption of F‐MRP for 8 weeks
Authors: Han Youngmin , Lee Soyeon , Lee Jong Ho , Yoo Hye Jin 
Published: May 2021

ScopeThe authors used metabolomics to investigate the nutritional modulatory effect of fermented Maillard‐reactive whey protein (F‐MRP) on the activity of natural killer (NK) cells.Methods and ResultsFifty subjects who had participated in our previous intervention study were included in the present study in the test (n = 20) and placebo groups (n = 30). Additional analyses using ultra performance liquid chromatography‐mass spectrometry (UPLC‐MS) and gas chromatography (GC)‐MS were conducted to identify relevant metabolic features. After 8 weeks, the activity of lipoprotein‐associated phospholipase A2 (Lp‐PLA₂) (p = 0.021), levels of interleukin (IL)‐1β (p = 0.001), and activity of NK cells were considerably increased in the test group compared with those in the placebo group. Based on the metabolites discovered by UPLC‐MS, ten altered metabolic pathways were observed in the test group after 8 weeks of F‐MRP consumption. Specific pathways with most pronounced associations with immune‐enhancing effect of F‐MRP included aminoacyl‐tRNA biosynthesis, glycine/serine/threonine metabolism, arginine/proline metabolism, and sphingolipid metabolism.ConclusionsThe present study demonstrated the effects of 8 weeks of F‐MRP supplementation on the metabolic status manifested as changes in the Lp‐PLA2 activity, IL‐1β level, and activity of NK cells. Intermediate metabolites of the identified metabolic pathways can be used to confirm the immune‐enhancing efficacy of short‐term supplementation.