bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identifying evaporation fractionation and streamflow components based on stable isotopes in the Kaidu River Basin with mountain–oasis system in north‐west China
Authors: Haiyan Chen , Yaning Chen , Weihong Li , Xinming Hao , Yupeng Li , Qifei Zhang 
Published: June 2018

AbstractBased on stable isotopes in stream water, groundwater, and meltwater in the Kaidu River Basin, NW China, we estimated the evaporation enrichment of stable oxygen isotopes in different types of water and separated the contribution of each streamflow component in river run‐off. Our results indicated that δ18O and δ2H in stream water did not vary with altitude regularly but with seasons, with low concentrations in spring and high concentrations in summer. However, the seasonal variations of δ18O and δ2H in groundwater were not as obvious. The mean evaporation enrichment was between 26% and 44% for δ18O. Of the various water types under investigation, we found glaciers were influenced the most, showing an evaporation enrichment of 44%, followed by oasis groundwater (37%), stream water (36%), and mountain groundwater (26%). Overall, meltwater and groundwater were the predominant streamflow components, with their contributions were governed by temperature, and varied both temporally and specially. In the oasis region, groundwater was the predominant contributor (64% in spring, 50% in summer, and 66% in autumn), whereas in the mountains, groundwater was the dominant in spring (53%) and autumn (51%), and meltwater contributed the most in summer (52%). Precipitation contributed less than 15% to the streamflow.
Climate change and hydrology at the prairie margin: Historic and prospective future flows of Canada's Red Deer and other Rocky Mountain rivers
Authors: Philipsen Laurens J. , Gill Karen M. , Shepherd Anita , Rood Stewart B. 
Published: June 2018

AbstractThe South Saskatchewan River Basin of southern Alberta drains the transboundary central Rocky Mountains region and provides the focus for irrigation agriculture in Canada. Following extensive development, two tributaries, the Oldman and Bow rivers, were closed for further water allocations, whereas the Red Deer River (RDR) remains open. The RDR basin is at the northern limit of the North American Great Plains and may be suitable for agricultural expansion with a warming climate. To consider irrigation development and ecological impacts, it is important to understand the regional hydrologic consequences of climate change. To analyse historic trends that could extend into the future, we developed century‐long discharge records for the RDR, by coordinating data across hydrometric gauges, estimating annual flows from seasonal records, and undertaking flow naturalization to compensate for river regulation. Analyses indicated some coordination with the Pacific decadal oscillation and slight decline in summer and annual flows from 1912 to 2016 (−0.13%/year, Sen's slope). Another forecasting approach involved regional downscaling from the global circulation models, CGCMI‐A, ECHAM4, HadCM3, and NCAR‐CCM3. These projected slight flow decreases from the mountain headwaters versus increases from the foothills and boreal regions, resulting in a slight increase in overall river flows (+0.1%/year). Prior projections from these and other global circulation models ranged from slight decrease to slight increase, and the average projection of −0.05%/year approached the empirical trend. Assessments of other rivers draining the central and northern Rocky Mountains revealed a geographic transition in flow patterns over the past century. Flows from the rivers in Southern Alberta declined (around −0.15%/year), in contrast to increasing flows in north‐eastern British Columbia and the Yukon. The RDR watershed approaches this transition, and this study thus revealed regional differentiation in the hydrological consequences from climate change.
Effects of the geometry of two‐dimensional fractures on their hydraulic aperture and on the validity of the local cubic law
Authors: Hajjar Ahmad , Scholtès Luc , Oltéan Constantin , Buès Michel Antoine 
Published: June 2018

AbstractFlow through rough fractures is investigated numerically in order to assess the validity of the local cubic law for different fracture geometries. Two‐dimensional channels with sinusoidal walls having different geometrical properties defined by the aperture, the amplitude, and the wavelength of the walls' corrugations, the corrugations asymmetry, and the phase shift between the two walls are considered to represent different fracture geometries. First, it is analytically shown that the hydraulic aperture clearly deviates from the mean aperture when the walls' roughness, the phase shift, and/or the asymmetry between the fracture walls are relatively high. The continuity and the Navier–Stokes equations are then solved by means of the finite element method and the numerical solutions compared to the theoretical predictions of the local cubic law. Reynolds numbers ranging from 0.066 to 66.66 are investigated so as to focus more particularly on the effect of flow inertial effects on the validity of the local cubic law. For low Reynolds number, typically less than 15, the local cubic law properly describes the fracture flow, especially when the fracture walls have small corrugation amplitudes. For Reynolds numbers higher than 15, the local cubic law is valid under the conditions that the fracture presents a low aspect ratio, small corrugation amplitudes, and a moderate phase lag between its walls.
Validating the KAGIS black‐box GIS‐based model in a Mediterranean karst aquifer: Case of study of Mela aquifer (SE Spain)
Authors: Valdes‐Abellan Javier , Pla Concepción , Fernandez‐Mejuto Miguel , Andreu José Miguel 
Published: June 2018

AbstractKarst Aquifer GIS‐based model (KAGIS model) is developed and applied to Mela aquifer, a small karst aquifer located in a Mediterranean region (SE Spain). This model considers different variables, such as precipitation, land use, surface slope and lithology, and their geographical heterogeneity to calculate both, the run‐off coefficients and the fraction of precipitation which contributes to fill the soil water reservoir existing above the aquifer. Evapotranspiration uptakes deplete water, exclusively, from this soil water reservoir and aquifer recharge occurs when water in the soil reservoir exceeds the soil field capacity. The proposed model also obtains variations of the effective porosity in a vertical profile, an intrinsic consequence of the karstification processes. A new proposal from the Nash–Sutcliffe efficiency index, adapted to arid environments, is presented and employed to evaluate the model's ability to predict the water table oscillations. The uncertainty in the model parameters is determined by the Generalized Likelihood Uncertainty Estimation method. Afterwards, when KAGIS is calibrated, wavelet analysis is applied to the resulting data in order to evaluate the variability in the aquifer behaviour. Wavelet analysis reveals that the rapid hydrogeological response, typical of a wide variety of karst systems, is the prevailing feature of Mela aquifer. This study proves that KAGIS is a useful tool to quantify recharge and discharge rates of karst aquifers and can be effectively applied to develop a proper management of water resources in Mediterranean areas.
The role of operating parameters and irradiation on the electrochemical degradation of tetracycline on boron doped diamond anode in environmentally relevant matrices
Authors: Frontistis Zacharias , Meriç Sureyya 
Published: June 2018

AbstractBACKGROUNDNowadays, due to the inappropriate use of antibiotics, significant quantities have been detected in environmental samples. Therefore there is a need for a technology to eliminate the accumulation of pharmaceuticals in receiving water bodies. In recent years electrochemical oxidation showed superior efficiency for the purification of water from pharmaceuticals.RESULTSboron doped diamond (BDD) showed better efficiency than platinum electrode and stainless steel for the degradation of 500 µg L−1 tetracycline (TC) with 0.1 mol L−1·Na2SO4. The presence of 200 mg L−1 bicarbonates decreased the apparent kinetic constant from 0.328 to 0212 min−1. Instead, the addition of 200 mg L−1 NaCl increased the kinetic constant by almost four times, while the presence of 10 mg L−1 of humic acid decreased the kinetic constant by 18%. The process was favored in real environmental matrices like bottled water and wastewater in comparison with ultrapure water. The use of BDD as both anode and cathode enhanced the efficiency by almost 20%. The presence of UVA or solar radiation increased the decomposition of tetracycline by 14%. Changes in toxicity to Vibrio fisheri bacteria during treatment of TC in the secondary effluent are mainly attributed to the formation of intermediates of the water matrix itself and does not follow the TC removal.CONCLUSIONSElectrochemical oxidation was favored for removal of TC in real water matrices due to the presence of chlorides. The use of BDD as both anode and cathode with simultaneous solar irradiation is a promising technology for water remediation from TC. © 2018 Society of Chemical Industry
Behavioral variation in nesting phenology may offset sex‐ratio bias in tuatara
Authors: Nelson Nicola J. , Keall Susan N. , Refsnider Jeanine M. , Carter Anna L. 
Published: June 2018

AbstractThe nest environment for eggs of reptiles has lifelong implications for offspring performance and success, and, ultimately, for population viability and species distributions. However, understanding the various abiotic and biotic drivers of nesting is complex, particularly regarding variation in nesting behavior of females and consequences for sex ratios in species with temperature‐dependent sex determination (TSD). We investigated how nest construction and nesting phenology affect the incubation environment of a reptile with TSD, the tuatara (Sphenodon punctatus), a species that is at risk from climate‐mediated male bias in population sex ratios. Using longitudinal behavioral data, we addressed the following questions. (1) Does nesting behavior vary with seasonal or location cues? (2) Does variation in nesting phenology or nest construction affect the incubation environment? We aimed to investigate whether female tuatara could modify nesting behavior to respond to novel environments, including a warming climate, allowing for successful incubation and balanced population sex ratios, maintaining population viability throughout their historic range. We predicted that earlier nesting after warm winters increased the likelihood that females will be produced, despite the sex determining system where males are produced from warmer temperatures. Further research is needed to understand the extent to which nesting behavior varies by individual through time, and across the range of tuatara, and the importance of habitat variability in maintaining production of females under future climate warming.
Sensitive monitoring of taurine biomarker in unprocessed human plasma samples using a novel nanocomposite based on poly(aspartic acid) functionalized by graphene quantum dots
Authors: Shadjou Nasrin , Alizadeh Salar , Hasanzadeh Mohammad 
Published: June 2018

AbstractThe rapid and accurate determination of the level of taurine biomarker in various tissues and body fluids can be of great interest in the early diagnosis of several important pathologies and diseases. For the first time, this study reports on the electropolymerization of a low toxic and biocompatible nanocomposite “poly(aspartic acid)–graphene quantum dots (GQDs)” as a novel strategy for surface modification of glassy carbon electrode and preparation a new interface for measurement of taurine. Electrochemical deposition, as a well‐controlled synthesis procedure, has been used for subsequently layer‐by‐layer preparation of GQDs nanostructures on poly(aspartic acid) using cyclic voltammetry techniques in the regime of −1.5 to 2 V. The field emission scanning electron microscopy indicated immobilization of uniformly GQDs onto poly(aspartic acid) film. The modified electrode appeared as an effective electroactivity for detection of taurine biomarker using cyclic voltammetry, chronoamperometry, and differential pulse voltammetry. Enhancement of peak currents is ascribed to the fast heterogeneous electron transfer kinetics that arise from the synergistic coupling between the excellent properties of poly(aspartic acid) as semiconducting polymer, GQDs as high density of edge plane sites, and subtle electronic characteristics to chemical modification. Under the optimized analysis conditions, the prepared sensor for detection of taurine showed a low limit of quantification 0.001mM. Finally, the resulting prepared sensor allow the quantification of these biomarkers directly in biological samples without need of derivatization schemes or sample pretreatment.
Genetic support vector machines as powerful tools for the analysis of biomedical Raman spectra
Authors: Hunter Robert , Anis Hanan 
Published: June 2018

AbstractThe growing number of applications of Raman spectroscopy in medicine necessitates the development of robust and accurate processing methods. The two major tasks for which Raman spectra are used are quantifying chemical species in a sample (regression) and discriminating chemically distinct samples (classification). Conventionally, linear techniques, primarily projection to latent structures (PLS), are used to perform these tasks. However, there are a number of nonlinearities that may arise when acquiring the Raman spectra of biomedical samples, such as scattering differences between tissues or autofluorescence variances, which makes nonlinear methods more suitable. To this end, we compared kernelized support vector machines (SVM) to PLS for a number of biomedical Raman datasets. Additionally, this work develops a genetic SVM, wherein the parameters of a SVM are selected by a classical genetic algorithm instead of the conventional grid search. This facilitates the use of complex kernels, which yield higher performance than simple kernel functions. We have found that this genetic SVM outperforms PLS in all of the regression tasks examined in this paper, while yielding equivalent results for classification tasks. Additionally, we have found that the genetic algorithm provides significant time savings in the optimization of the SVM parameters over grid search.
Synergistic thermo‐Raman and calorimetric kinetic study of the cation modifier's role in binary metaphosphate glasses
Authors: Sendova Mariana , Jiménez José A. 
Published: June 2018

AbstractA comprehensive temperature‐dependent Raman spectroscopy and differential scanning calorimetry study has been performed on three metaphosphate glasses with different modifying cations (Ca2+, Ba2+, and Pb2+). The P–NBO (nonbridging oxygen) Raman spectral feature, the force constant, and the glass transition activation energy (AETg) are shown to be strongly correlated to the relative effective nuclear charge difference between the modifying and the glass former cations, ζ. In addition, the estimated AETg values between 3.6(2) and 4.7(2) eV are found to be in the range of the P–O bond energy values in the phosphate glasses. The study contributes to the enrichment of the bond exchange kinetic theory of the glass transition in general and to the bond modifying mechanism of the cations. The authors propose that Raman spectroscopy alone can be implemented reliably for evaluation not only of AETg, but for calculation of the Morse potential of the moiety crucial for the onset of glass transition. Alternatively, in glasses without Raman scattering, the force constant of the critical moiety can be deduced from calorimetric measurements alone. The proposed analytical methodology broadens Raman spectroscopy and calorimetric applications and offers a viable technique for all types of glass matrices.
Protein hydrolysates and ultrafiltered < 1 KDa fractions from Phaseolus lunatus, Phaseolus vulgaris and Mucuna pruriens exhibit antihyperglycemic activity, intestinal glucose absorption and α‐glucosidase inhibition with no acute toxicity in rodents
Authors: Nuñez‐Aragón Pablo N , Segura‐Campos Maira , Negrete‐León Elizabeth , Acevedo‐Fernández Juan J , Betancur‐Ancona David , Chel‐Guerrero Luis , Castañeda‐Corral Gabriela 
Published: June 2018

AbstractBACKGROUNDProtein hydrolysates from food plants, such as legumes, have emerged as a new alternative to treat hyperglycemia, an important risk factor contributing to the development of type 2 diabetes mellitus (T2DM) and its complications. The aim of this work was to assess the antihyperglycemic activity and inhibition of α‐glucosidase, and intestinal glucose absorption, and acute toxicity of total hydrolysates and < 1 kDa fractions from Phaseolus lunatus L., Phaseolus vulgaris L., and Mucuna pruriens (L.) DC., obtained by hydrolysis with Alcalase®‐Flavourzyme® or pepsine‐pancreatin enzymatic systems.RESULTSIn vivo results showed that three of six total hydrolysates and four of six < 1 kDa fractions suppressed starch‐induced postprandial hyperglycemia (ED50 range between 1.4 and 93 mg kg−1). In vitro, total hydrolysates and fractions, particularly from M. pruriens, inhibited carbohydrate intestinal absorption (from 19.2 to 40%), and α‐glucosidase activity (IC50 from 0.86 to 75 mg mL−1). Finally, none of the hydrolysates and fractions tested did not show any signs of toxicity (LD50 > 5000 mg kg−1).CONCLUSIONThese results suggest that hydrolysates and < 1 kDa fractions from P. lunatus, P. vulgaris and M. pruriens are suitable candidates to treat or prevent T2DM. © 2018 Society of Chemical Industry
Kinetics, mass transfer, and thermodynamic and statistical modeling study for esterification of valeric acid with n‐butanol: Homogeneous and heterogeneous catalysis
Authors: Khudsange Chandrakant R. , Wasewar Kailas L. 
Published: June 2018

AbstractThe esterification of valeric acid with n‐butanol was studied with homogeneous and heterogeneous catalysts. The activity and performance of homogeneous p‐toluenesulfonic acid and heterogeneous cation exchange resin catalysts Amberlyst 36, Indion 190, and Amberlite IRC‐50 were evaluated. The pseudo‐homogeneous kinetic model was used to investigate the kinetic parameters of homogeneous‐ and heterogeneous‐catalyzed esterification. The UNIFAC (universal functional activity coefficient) approach was used to study the nonideality of the esterification reaction. The reaction was statistically modeled and optimized by the application of response surface methodology. The effects of independent variables such as reaction temperature, initial molar ratio, and catalyst loading on the conversion of valeric acid were investigated. The optimized conditions for the esterification reaction catalyzed by Amberlyst‐36 were found as temperature 360.4 K, initial molar ratio 3.8, and catalyst loading 6.7 wt%. The predicted conversion (89%) at these optimized conditions is in good agreement with the experimental conversion (87.3 ± 1.6%).
Nonstoichiometric Stille Coupling Polycondensation via an Intramolecular Pd(0) Catalyst Transfer Using Excess Phthalimide Monomer
Authors: Terayama Kosuke , Goto Eisuke , Higashihara Tomoya 
Published: June 2018

AbstractNonstoichiometric polycondensations via Stille coupling reactions are successfully used to obtain high‐molecular‐weight π‐conjugated polymers using 2,5‐bis(trimethylstannyl)thiophene and a dibromo phthalimide monomer, N‐hexyldecyl‐3,6‐dibromophthalimide (2), in excess from 1:1 to 1:10. The intramolecular Pd(0) catalyst transfer on 2 substituted at the polymer terminal occurs as suggested by the model reaction between 2‐(tributylstannyl)thiophene and an equimolar amount of N‐octyl‐3,6‐dibromophthalimide (4), and the reaction generates only the disubstituted compound and excess 4 in an almost 1:1 ratio. The effect of the structures of the ligands and monomers on the polymerization under nonstoichiometric conditions is investigated to elucidate the criteria for the successful intramolecular catalyst transfer. The combination of the imide structure and an electron‐rich ligand is important for promoting the catalyst transfer.
Novel Mechanism of Fatty Acid Sensing in Enteroendocrine Cells: Specific Structures in Oxo‐Fatty Acids Produced by Gut Bacteria Are Responsible for CCK Secretion in STC‐1 Cells via GPR40
Authors: Hira Tohru , Ogasawara Shono , Yahagi Asuka , Kamachi Minami , Li Jiaxin , Nishimura Saki , Sakaino Masayoshi , Yamashita Takatoshi , Kishino Shigenobu , Ogawa Jun , Hara Hiroshi 
Published: June 2018

ScopeThe secretion of gut hormones, such as cholecystokinin (CCK) is stimulated by fatty acids. Although a chain length–dependent mechanism has been proposed, other structural relationships to releasing activity remain unclear. We aimed to elucidate specific structures in fatty acids that are responsible for their CCK‐releasing activity, and related sensing mechanisms in enteroendocrine cells.Methods and resultsCCK secretory activities were examined in a murine CCK‐producing cell line STC‐1 by exposing the cells to various modified fatty acids produced by gut lactic acid bacteria. The effects of fatty acids on gastric emptying rate as a CCK‐mediated function were examined using acetaminophen and phenol red methods in rats. Out of more than 30 octadecanoic‐derived fatty acids tested, 5 oxo‐fatty acids potently stimulated CCK secretion without cytotoxic effects in STC‐1 cells. Three fatty acids had a distinct specific structure containing one double bond, whereas the other two had two double bonds, nearby an oxo residue. CCK secretion induced by representative fatty acids (10‐oxo‐trans‐11‐18:1 and 13‐oxo‐cis‐9,cis‐15‐18:2) was attenuated by a fatty acid receptor G‐protein coupled receptor 40 antagonist. Oral administration of 13‐oxo‐cis‐9,cis‐15‐18:2 lowered the gastric emptying rate in rats in a dose‐ and structure‐dependent manner.ConclusionThese results reveal a novel fatty acid‐sensing mechanism in enteroendocrine cells.
Initial assessment versus gradual change in early childhood behavior problems―Which better foretells the future?
Authors: McDermott Paul A. , Rovine Michael J. , Buek Katharine W. , Reyes Roland S. , Chao Jessica L. , Watkins Marley W. 
Published: June 2018

AbstractLeading research argues the distinct importance of earliest detection of childhood behavior problems and the value of discovering subsequent change patterns as children transition through the early education years. This study examined the relative contributions of earliest assessments of children's problem behaviors as compared to the changes in those behaviors over time for the prediction of important later outcomes. Focusing on the representative national sample from the Head Start Impact Study (n = 3,827), classroom behavior problems were assessed across 4 years spanning prekindergarten through first grade. Individual child indices were derived in multilevel growth modeling to reflect initial assessments and subsequent change patterns. These indices were thereafter applied in multilevel logistic regression and receiver operating characteristic curve analyses to predict later academic and social difficulties. Both children's initial assessments and their transitional changes proved to be good predictors of most outcomes, where the accuracy for initial assessments and transitional changes was effectively equivocal. The evidence clarifies that initial assessment of behavior problems is sufficient to predict later outcomes; additional assessments did not augment forecasting accuracy nor did the combination of both initial assessment and information about subsequent change improve accuracy. Implications are discussed for assessment theory and practice.