bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seaduck engineers in the Arctic Archipelago: nesting eiders deliver marine nutrients and transform the chemistry of island soils, plants, and ponds
Authors: Clyde N. , Hargan K. E. , Forbes M. R. , Iverson S. A. , Blais J. M. , Smol J. P. , Bump J. K. , Gilchrist H. G. 
Published: March 2021

AbstractSeabirds are thought to provide ecological services such as the movement of nutrients between marine and terrestrial ecosystems, which may be especially critical to productivity and diversity in nutrient-poor environments. Most Arctic ecosystems are unaffected by local human impacts and are naturally nutrient poor and especially sensitive to warming. Here, we assessed the effects of nesting common eider ducks (Somateria mollissima) on soil, vegetation, and pond sediments on island archipelagoes in Hudson Strait between Nunavut and Québec, Canada. Soil, moss, and pond sediments were significantly higher in nitrogen on islands with large numbers of nesting eiders compared to sites with no nesting birds. The highest concentrations of nitrogen in soils and moss occurred at the margins of ponds on eider islands, which correspond to the areas of highest eider use. δ15N and δ34S values in soils, moss, and sediments indicated substantial marine-derived organic matter inputs at the higher nutrient sites. We propose that by foraging on coastal marine benthic invertebrates and returning to islands to nest, eider ducks bio-transport and concentrate marine-derived nutrients to their colony islands, fertilizing Arctic island ecosystems in the process. As common eiders nest on thousands of low to mid-latitude islands throughout the circumpolar Arctic, these nutrient inputs likely dramatically affect biota and ecosystem functioning throughout the tundra biome.
Kinetic modeling of anaerobic degradation of plant-derived aromatic mixtures by Rhodopseudomonas palustris
Authors: Ma Yanjun , Donohue Timothy J. , Noguera Daniel R. 
Published: March 2021

AbstractRhodopseudomonas palustris is a model microorganism for studying the anaerobic metabolism of aromatic compounds. While it is well documented which aromatics can serve as sole organic carbon sources, co-metabolism of other aromatics is poorly understood. This study used kinetic modeling to analyze the simultaneous degradation of aromatic compounds present in corn stover hydrolysates and model the co-metabolism of aromatics not known to support growth of R. palustris as sole organic substrates. The simulation predicted that p-coumaroyl amide and feruloyl amide were hydrolyzed to p-coumaric acid and ferulic acid, respectively, and further transformed via p-coumaroyl-CoA and feruloyl-CoA. The modeling also suggested that metabolism of p-hydroxyphenyl aromatics was slowed by substrate inhibition, whereas the transformation of guaiacyl aromatics was inhibited by their p-hydroxyphenyl counterparts. It also predicted that substrate channeling may occur during degradation of p-coumaroyl-CoA and feruloyl-CoA, resulting in no detectable accumulation of p-hydroxybenzaldehyde and vanillin, during the transformation of these CoA ligated compounds to p-hydroxybenzoic acid and vanillic acid, respectively. While the simulation correctly represented the known transformation of p-hydroxybenzoic acid via the benzoyl-CoA pathway, it also suggested co-metabolism of vanillic acid and syringic acid, which are known not to serve as photoheterotrophic growth substrate for R. palustris.
PatchIndex: exploiting approximate constraints in distributed databases
Authors: Kläbe Steffen , Sattler Kai-Uwe , Baumann Stephan 
Published: March 2021

AbstractCloud data warehouse systems lower the barrier to access data analytics. These applications often lack a database administrator and integrate data from various sources, potentially leading to data not satisfying strict constraints. Automatic schema optimization in self-managing databases is difficult in these environments without prior data cleaning steps. In this paper, we focus on constraint discovery as a subtask of schema optimization. Perfect constraints might not exist in these unclean datasets due to a small set of values violating the constraints. Therefore, we introduce the concept of a generic PatchIndex structure, which handles exceptions to given constraints and enables database systems to define these approximate constraints. We apply the concept to the environment of distributed databases, providing parallel index creation approaches and optimization techniques for parallel queries using PatchIndexes. Furthermore, we describe heuristics for automatic discovery of PatchIndex candidate columns and prove the performance benefit of using PatchIndexes in our evaluation.
Potential toxicity of leachate from the municipal landfill in view of the possibility of their migration to the environment through infiltration into groundwater
Authors: Jabłońska-Trypuć Agata , Wydro Urszula , Wołejko Elżbieta , Pietryczuk Anna , Cudowski Adam , Leszczyński Jacek , Rodziewicz Joanna , Janczukowicz Wojciech , Butarewicz Andrzej 
Published: March 2021

AbstractLeachate from landfills is a product of complex biological and physicochemical processes occurring during waste storage. In the present study, the toxicity of landfill leachate (LL) to human and bacterial cells was investigated for better understanding of LL environmental toxicity. Studies regarding LL physicochemical properties and cytotoxicity analysis were conducted. In Escherichia coli, Pseudomonas fluorescens, Bacillus subtilis, fibroblasts and melanoma A-375 cells, cell viability assays were applied. For the determination of LL antibacterial activity, twofold dilution series of LL were prepared in the range from 50% to 0.1% (50%, 25%, 12.5%, 6.25%, 3.13%, 1.56%, 0.78%, 0.39%, 0.2%, 0.1%). Human cells viability was examined at LL concentrations of 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 5%, 10%, 15%, 20% and 30%. ROS (reactive oxygen species) content and apoptosis level were also measured in bacterial and human cells under the influence of LL. Unexpectedly obtained results indicate stimulation of bacterial viability by LL. Fibroblasts under the influence of LL showed decrease in their viability and increase in apoptosis level and A-375 melanoma cells showed an increase in relative viability and decrease in apoptosis. ROS level in bacterial cells was elevated in higher LL concentrations and decreased in lower LL concentrations. In human cells, ROS content was rather high in both tested cell lines. Presented results indicate cytotoxic potential of analyzed LL and the necessity of LL monitoring because it may pose a health hazard for exposed human populations and the whole human environment.
More than the sum of their parts: reconstituting the paleopathological profile of the individual and commingled Neolithic populations of Western Switzerland
Authors: Abegg C. , Desideri J. , Dutour O. , Besse M. 
Published: March 2021

AbstractThis research focuses on the Neolithic populations of Western Switzerland (5500–2200 BCE) and on establishing their paleopathological profile. This chronological period presents varying burial practices, and the aim was to be able to synthesise all information regarding the pathologies these populations exhibited, in such a way that statistical tests could be performed to determine whether geographical (site location), biological (age, sex, stature) and chronological factors played a role in lesion distribution. As a result, a methodology was devised to consider bone lesions in both a quantified and qualified manner, and able to handle individualised, multiple and commingled remains. The statistical analysis showed that pathological profiles differed depending on site location, with some exhibiting patterns that raise further questions as to the socio-economical functioning of these prehistoric societies. Biological factors also appear to play a role in lesion distribution, with immature individuals exhibiting more metabolic deregulations, whilst the adults—as expected—showed more signs of degenerative pathologies. Some chronological evolution of health is also perceivable; however, the small sample size available for some periods means these results are tentative at best. These remains, however, proved more than an accumulation of bone lesions, and the qualified data collected from them also yielded individual and collective narratives of health. Instances of infectious diseases were discovered, indicating that pathologies such as tuberculosis were a persistent presence at the time, with all the consequences this entails.
Effects of competitive physical activity on serum irisin levels and bone turnover markers
Authors: Gaudio A. , Rapisarda R. , Xourafa A. , Zanoli L. , Manfrè V. , Catalano A. , Signorelli S. S. , Castellino P. 
Published: March 2021

Abstract
Background
Irisin, a myokine, is a polypeptide derived from the cleavage of the extracellular domain of fibronectin domain-containing protein 5, a receptor that is present on different tissues (skeletal muscle, pericardium, myocardium, and brain), whose functions are not yet fully defined.

Purpose
The main aim of our study was to evaluate the effect of competitive physical activity on serum irisin levels and bone turnover markers.

Methods
Fifteen male footballers and an equal number of subjects of the same age and gender, but with a predominantly sedentary lifestyle, had their serum levels of irisin and bone turnover markers measured. Bone mineral status was evaluated in both groups by quantitative bone ultrasound of the calcaneus. In addition, only in footballers, biochemical analyses were repeated after 3 months.

Results
We did not observe significant differences in the serum levels of calcium, phosphorus, and parathyroid hormone between the two groups. The footballers had significantly higher quantitative bone ultrasound, 25-OH vitamin D, and creatinine values than the controls. There were also no significant differences in the bone alkaline phosphatase, carboxy-terminal telopeptide of type I collagen, osteoprotegerin, sclerostin or Dkk-1 values, while the irisin levels (+ 89%, p < 0.001) and RANKL were significantly higher in the footballers compared to those in the controls.

Conclusion
Our study shows that footballers have significantly higher serum irisin values than the general population. Irisin could be the "trait d’union" between bone health and physical activity.
Dynamics of the Causes Of Crime: a Life-Course Application of Situational Action Theory for the Transition from Adolescence to Adulthood
Authors: Kessler Georg , Reinecke Jost 
Published: March 2021

Abstract
Purpose
According to the Developmental Ecological Action Model (DEA) of the situational action theory (SAT), changes in crime rates over the life-course are explained through personal (moral) maturation and socio-ecological selection. This assumption is empirically tested by comparing results for the conditioning effect of the principle of moral correspondence (as an essential part of SAT’s perception-choice process) on crime rates for the transition from adolescence to adulthood.

Methods
Comparing two waves of a German longitudinal study (CrimoC, 17 and 26 years old, n = 1738), a series of logistic and multinomial logistic regressions and ensuing estimated transition probabilities capture the cross-sectional but also developmental processes involved. Additionally, the CrimoC study offers a differential analysis of offending scales, separating offenses into youth and adult crimes.

Results
The principle’s conditioning effect on crime could be replicated at both times. We can observe a general trend of individual transitions, which correspond to predicted personal maturation and socio-ecological selection. The transitions correlate with the expected reduction in crime rates over time. Males and females show comparable results. The separation into different offending scales yielded tentative insights.

Conclusion
We found stability in the mechanisms leading to crime as proffered by SAT and DEA across time. Personal (moral) maturation and socio-ecological selection are likely to be the driving forces behind reducing crime in adulthood. Future research needs to explain in detail how life-course events influence these factors. Considering adult crimes in the analysis is a promising endeavor that warrants further investigation.
Phase growth in alpha brass with thin layer of electroplated zinc during homogenization annealing
Authors: Basak P. S. 
Published: March 2021

AbstractDiffusion mechanism in between thin electroplated Zn coating and Cu – 37wt%Zn substrate during homogenization annealing substantially depends on electroplating parameters. Experiments carried out to determine phase growth and solute profile at various current densities reveal that the increase of current density tends to reduce phase growth. The coefficient of phase growth has been determined and is found to be dependent on the relative density of plating layer.
Performance evaluation of graphite and titanium oxide powder mixed dielectric for electric discharge machining of Ti–6Al–4V
Authors: Alam Shahriar Tanvir , Amin AKM Nurul , Hossain Md. Ibrahim , Huq Maliha , Tamim Shaqauit Hossain 
Published: March 2021

AbstractTi–6Al–4V is the most commonly used titanium alloy in aerospace, marine, and biomedical applications. Due to the properties of poor machinability in conventional machining, Electrical Discharge Machining (EDM) is considered a prospective alternative for machining this strategic material. This study aims at enhancing the performance of powder mixed EDM (PMEDM) in the machining of Ti–6Al–4V with the application of two different types of powders, namely Graphite (Gr) and Titanium Oxide (TiO2) powders, with different concentrations in dielectric—kerosene. The effect of these powers and their relative quantities are studied in terms of metal removal rate (MRR), tool wear rate, Surface Roughness, and surface integrity. Machining is performed using the copper electrode and kerosene as the dielectric medium. A separate container and a submersible pump are used to limit the quantity of powder and keep the powder in suspension, respectively. Design of experiments guided by Design-Expert software is employed to minimize the number of experimental runs and develop empirical models of response parameters in terms of the variable parameters—peak current, powder type, and powder concentration. Findings indicate that TiO2 powder has a much higher effect on MRR compared to graphite powder, as the maximum MRR in the case of TiO2 powder is recorded 41.01 mm3/min against 11.98 mm3/min for graphite powder, i.e., 3.42 times higher. Similarly, the tool wear ratio for TiO2 powder is 0.0704 against 0.1219 for graphite powder at the maximum MRR, which is 1.73 times lower compared to that of graphite powder. The same ratios at the minimum MRR for TiO2 is 0.0098, and for graphite power is 0.0282, which is again 2.88 times lower compared to that of graphite powder. In terms of average surface roughness, Ra, the performance of TiO2 is far better compared to graphite powder since the maximum surface roughness attained with TiO2 powder is 3.265 μm against 9.936 μm for graphite powder at the highest MRR and the same attained at the lowest MRR are 2.228 μm and 2.411 μm for TiO2 and graphite powders respectively. The mechanism of the effects of PMEDM on surface texture has also been observed using SEM images to study the influence of powder concentration on surface morphology.
Miocene to Early Pleistocene Depositional History and Tectonic Evolution of the Issyk‐Kul Basin, Central Tian Shan
Authors: Roud Sophie C. , Wack Michael R. , Gilder Stuart A. , Kudriavtseva Anna , Sobel Edward R. 
Published: March 2021

AbstractThe Issyk‐Kul Basin (Kyrgyzstan), situated in the central Tian Shan Mountains, hosts the largest and deepest mountain lake in Central Asia. Erosion of the surrounding Terskey and Kungey ranges led to the accumulation of up to 4 km of sediment in the adjacent depression. Creation of the basin from regional shortening and uplift likely initiated around the Oligocene‐Miocene, yet precise age control is sparse. To better understand the timing of these processes, we obtained magnetostratigraphic age constraints on fossil‐poor, fluvio‐lacustrine sediments exposed south of Lake Issyk‐Kul, that agree well with previous age constraints of the equivalent strata outside the Issyk‐Kul Basin. Two 500–650 m thick sections comprised mainly of Chu Group sediments were dated at 6.3–2.8 Ma and 7.0–2.4 Ma (late Miocene to early Pleistocene). Together with reinterpreted magnetostratigraphic constraints from underlying strata, we find that syn‐tectonic deposition commenced at ∼22 Ma with average sedimentation rates <10 cm/ka. Sedimentation rates increased to 10–30 cm/ka at 7 Ma, concurrent with accelerated uplift in the Terskey Range to the south. A deformation event in one section (Kaji‐Say) between 5 and 3 Ma together with concurrent shifts of depositional centers throughout the basin signal the onset of substantial uplift of the Kungey Range to the north at ∼5 Ma. This uplift and deformation transformed the Issyk‐Kul area into a closed basin that facilitated the formation of a deep lake. Lacustrine facies deposited around 3 Ma mark the existence of Lake Issyk‐Kul by that time.
An Enhanced MOD16 Evapotranspiration Model for the Tibetan Plateau During the Unfrozen Season
Authors: Yuan Ling , Ma Yaoming , Chen Xuelong , Wang Yuyang , Li Zhaoguo 
Published: March 2021

AbstractEvapotranspiration (ET) is composed of soil evaporation (ETs), canopy transpiration (ETc), and canopy intercepted water evaporation (ETw), and it plays an indispensable role in the water and energy cycles of land surface processes. More accurate estimations of variations in ET are essential for natural hazard monitoring and water resource management. An improved algorithm for ETs with soil moisture and texture (SMT) and an optimized ETc based on the MOD16 model (MOD16‐STM) are proposed for the cold, arid, and semiarid regions of the Tibetan Plateau (TP). The nonlinear relationships between the soil surface resistance (rss) and soil surface hydration state in different soil textures were redefined by using five flux tower measurements over the TP. The value of the mean potential stomatal conductance per unit leaf area (CL) used for ETc calculation in grasslands was optimized at 0.0038 (m s−1). The MOD16‐STM was compared with the MOD16 and a soil water index‐based Priestley‐Taylor algorithm (SWI‐PT) at five independent sites. The results showed that the half‐hourly, daily, and monthly estimations from the MOD16‐STM were closer to observations than those from the other two models. The results indicated that the MOD16‐STM increased R2 by 0.2/0.05 and the index of agreement by 0.37/0.23 and deceased RMSE by 43.89/42.77 W m−2 and the absolute mean bias (|MB|) by 46.23/45.89 W m−2, when compared to the results of the MOD16 at daily/monthly scales. The results suggested that the MOD16‐STM will produce more accurate ET estimates over the flux sites and has great potential for ET estimation and land surface model improvement for the TP region.
Improved Modeling of Spatiotemporal Variations of Fine Particulate Matter Using a Three‐Dimensional Variational Data Fusion Method
Authors: Zhang Xuguo , Fung Jimmy C. H. , Lau Alexis K. H. , Zhang Shaoqing , Huang Wei 
Published: March 2021

AbstractThe spatiotemporal concentration of multiple pollutants is crucial information for pollution control strategies to safeguard public health. Despite considerable efforts, however, significant uncertainty remains. In this study, a three‐dimensional variational model is coupled with a data assimilation (DA) system to analyze the spatiotemporal variation of PM2.5 for the whole of China. Monthly simulations of six sensitivity scenarios in different seasons, including different assimilation cycles, are carried out to assess the impact of the assimilation frequency on the PM2.5 simulations and the model simulation accuracy afforded by DA. The results show that the coupled system provides more reliable initial fields to substantially improve the model performance for PM2.5, PM10, and O3. Higher assimilation frequency improves the simulation in all geographic areas. Two statistical indicators—the root mean square error and the correlation coefficient of PM2.5 mass concentrations in the analysis field—are improved by 12.19 µg/m3 (33%) and 0.21 (48%), respectively. Although the 24‐h assimilation cycle considerably improves the model, assimilation at a 6‐h cycle raises the performance for PM2.5 to the performance goal level. The analysis shows that assimilating at a 24‐h cycle diminishes over time, whereas the positive impact of the 6‐h cycle persists. One pivotal finding is that the assimilation of PM2.5 in the outermost domain results in a substantial improvement in PM2.5 prediction for the innermost domain, which is a potential alternative method to the existing domain‐wide data fusion algorithm. The effect of assimilation varies among topographies, a finding that provides essential support for further model development.
Spatiotemporal Variation of Groundwater Recharge in the Lower Reaches of the Poyang Lake Basin, China: Insights From Stable Hydrogen and Oxygen Isotopes
Authors: Mao Hairu , Wang Guangcai , Shi Zheming , Liao Fu , Xue Yang 
Published: March 2021

AbstractUnderstanding of groundwater recharge and associated hydrological processes is important for sustainable management and utilization of water resources, especially in the monsoon regions. However, few systematic studies have been conducted on the spatiotemporal variation of groundwater recharge. In this study, stable isotopes of precipitation and groundwater were used to explore the spatiotemporal variation of groundwater recharge in the lower reaches of the Poyang Lake Basin of China, a region affected by the interplay of different monsoons. The results indicated that isotopic values (δ2H and δ18O) of precipitation exhibited obvious seasonal variations, higher in winter and lower in summer, controlled by different monsoons. The stable isotopes of groundwater also presented distinct seasonal variations, revealing the dominant influence of seasonal precipitation, but they had different characteristics in space. In the northern study area and Rao and Xin Basins, the isotopic signatures of groundwater showed the shift to lower values in summer and higher values in winter, consistent with those of precipitation, while in the Ganfu Plain, which is characterized by poorly permeable strata, isotopic signatures of groundwater presented opposite temporal variations than those of precipitation (lagged behind precipitation). The characteristics of groundwater isotopes might be linked with the spatial heterogeneity of groundwater recharge rate, which was affected by recharge mechanisms, lithology of aquifer materials, and interaction between groundwater and lake water. This study provides insights into the groundwater recharge of the Poyang Lake Basin and other similar areas.