bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seasonal differences in relationships between changes in spring phenology and dynamics of carbon cycle in grasslands
Authors: Xie Zhiying , Zhu Wenquan , Qiao Kun , Zhan Pei , Li Peixian 
Published: May 2019

AbstractGlobal warming is dramatically altering the plant phenology of terrestrial ecosystem and thus has caused significant effects on the terrestrial carbon cycle. Many studies have investigated the relationships between the spring phenological changes and the dynamics of carbon cycle, but the seasonal differences in these relationships are still unclear. This study used eddy covariance measurements of grassland net ecosystem productivity (NEP) from nineFLUXNETsites (73 site‐years of data) to investigate the relationships between the spring phenological changes (i.e., early green‐up,EGU; middle green‐up,MGU; and late green‐up,LGU) and the dynamics of carbon cycle (includingNEP; ecosystem respiration,ER; and gross ecosystem production,GEP) at a ten‐day scale. Weak relationships were found between the spring phenological changes and the dynamics ofERat all sites. The advance of spring phenology mainly caused significant increases inGEP(orNEP) during the initial 20–50 d after the green‐up date at most sites. With an advancement of 1 d inEGU(MGUandLGU),GEPandNEPwere increased by 1.5–6.0 (3.5–7.1 and 2.4–4.7) and 0.7–3.6 (1.5–3.9 and 1.9–4.7) g C/m2during the early growing season (EGS), respectively. The advance of spring phenology did not have significant impacts onGEP(orNEP) during the middle and late growing season (MGSandLGS) at most sites, but yielded a significant decrease inGEP(orNEP) duringMGSat a few sites. As the grasslands turning green, the duration of the impact of the changes inEGU,MGU, andLGUonGEP(orNEP) was reduced, whereas the magnitude of the impact of the changes on the ten‐day cumulativeGEP(orNEP) was increased at most sites. Thus, there were two possible impact models for the spring phenological changes on the dynamics of carbon cycle for grasslands: The advance of spring phenology only increases theGEP(orNEP) duringEGS, and the advance of spring phenology only decreases theGEP(orNEP) duringMGS. These results could be helpful in further understanding the influences of spring phenological changes on the dynamics of carbon cycle for grasslands.
Exposure to historical burn rates shapes the response of boreal caribou to timber harvesting
Authors: Lafontaine Alexandre , Drapeau Pierre , Fortin Daniel , Gauthier Sylvie , Boulanger Yan , St‐Laurent Martin‐Hugues 
Published: May 2019

AbstractStudying the response of wildlife to anthropogenic disturbances in light of their evolutionary history may help explain their capacity to adapt to novel ecological conditions. In the North American boreal forest, wildfire has been the main natural disturbance driving ecosystem dynamics for thousands of years. Boreal caribou (Rangifer tarandus caribou) is a threatened ungulate for which widespread decline has been associated with the rapid expansion of timber harvesting across its range. Although caribou may not be adapted to this new type of disturbance, cutovers share many similarities with wildfires by producing large landscapes of whole‐stand removal associated with an increased predation risk for caribou. We hypothesized that caribou with more evolutionary experience of fire disturbance should better perceive the cues associated with disturbances and adjust their behavior toward human disturbance accordingly. Given the extensive distribution of caribou populations in the boreal forest, we assessed how their historical exposure to wildfires could explain their behavioral response toward both burned and cutover areas. Our results indicate that caribou from regions with high historical burn rates displayed a consistent avoidance of recent burns (<5 yr old), and that this behavior translated in a similar avoidance of recent cutover, providing support to the cue similarity hypothesis. On the contrary, caribou with less evolutionary experience of wildfires were more likely to select recently disturbed (<5 yr‐old and 6–20 yr‐old) habitats. In the context that timber harvesting and its associated road network has been linked to increased mortality in boreal caribou populations, we discuss how this naïve habitat use of clearcuts can be exacerbated by historical disturbance regimes and become maladaptive for this endangered species.
Affinity capillary electrophoresis employed for determination of stability constants of antamanide complexes with univalent and divalent cations in methanol
Authors: Pangavhane Sachin , Makrlík Emanuel , Ruzza Paolo , Kašička Václav 
Published: May 2019

AbstractAffinity capillary electrophoresis (ACE) and pressure‐assisted ACE were employed to study the noncovalent molecular interactions of antamanide (AA), cyclic decapeptide from the deadly poisonous fungus Amanita phalloides, with univalent (Li+, Na+, K+, and NH4+) and divalent (Mg2+ and Ca2+) cations in methanol. The strength of these interactions was quantified by the apparent stability constants of the appropriate AA‐cation complexes. The stability constants were calculated using the nonlinear regression analysis of the dependence of the effective electrophoretic mobility of AA on the concentration of the above ions in the BGE (methanolic solution of 20 mM chloroacetic acid, 10 mM Tris, pHMeOH 7.8, containing 0–50 mM concentrations of the above ions added in the form of chlorides). Prior to stability constant calculation, the AA effective mobilities measured at actual temperature inside the capillary and at variable ionic strength of the BGEs were corrected to the values corresponding to the reference temperature of 25°C and to the constant ionic strength of 10 mM. From the above ions, sodium cation interacted with AA moderately strong with the stability constant 362 ± 16 L/mol. K+, Mg2+, and Ca2+ cations formed with AA weak complexes with stability constants in the range 37–31 L/mol decreasing in the order K+ > Ca2+ > Mg2+. No interactions were observed between AA and small Li+ and large NH4+ cations.
Precise measurement and control of the pressure‐driven flows for microfluidic systems
Authors: Zeng Wen , Fu Hai 
Published: May 2019

AbstractThe pressure‐driven device is designed and the flow rates of the microfluidic systems can be supplied by the pressure‐driven flows, which can significantly reduce the flow‐rate fluctuations coming from the pump source. For pressure‐driven flows, the flow rates of the fluids can be predicted by measuring the pressure drop along a polytetrafluoroethylene (PTFE) tubing. Especially, by varying the geometrical parameters of the PTFE tubing, the predicted flow rates of the fluids are compared with the experimental measurements, and the testing precision of the pressure‐driven flows can be obtained. Meanwhile, the dynamic characteristics of the open‐loop and closed‐loop control pressure‐driven device are comparatively studied. Particularly, a proportional and integral (PI) controller is integrated with the closed‐loop control pressure‐driven device, and the effects of the parameters of the PI controller on the dynamic characteristics of the pressure‐driven devices are mainly discussed. Most importantly, by improving the dynamic characteristics of the pressure‐driven devices, precise measurement and control of the pressure‐driven flows can be achieved for microfluidic systems.
An improved particle shifting technique for incompressible smoothed particle hydrodynamics methods
Authors: Akbari Hassan 
Published: May 2019

SummaryThe smoothed particle hydrodynamics (SPH) method is one of the powerful Lagrangian tools for modeling free surface flows. However, it suffers from particle disorder, which leads to interpolation and numerical errors. To overcome this problem, several techniques have been introduced until now, among which the particle shifting technique (PST) based on Fick's law is an efficient one. The current form of this method needs tuning parameters to fulfill numerical stability criteria. In this study, to eliminate calibration factors, a new shifting coefficient is derived theoretically based on particle positions before and after shifting, regardless of other parameters such as velocity, pressure, time step intervals, etc. The only required input is particle positions, and the main concern is conserving particle densities in their updated positions. In addition to the proposed PST, a new distribution index (DI) is introduced for measuring the spatial uniformity of particles. Furthering the research, some novel treatments are also studied to improve particle movements near free surface boundary. The proposed idea is only assessed for ISPH method in this study, and its performance in other SPH schemes needs more investigations. Following this innovative method, it is validated by modeling different cases including dam break flow, paddle movement, and elliptical water drop. In all cases, particle arrangements have been improved by means of the modified shifting method. In that sense, good agreements between simulation results with experimental data, analytical solutions, and other numerical methods approve the ability of the developed method in simulating free surface flows.
An improved axisymmetric lattice Boltzmann flux solver for axisymmetric isothermal/thermal flows
Authors: Zhang Liangqi , Chen Zhen , Yang Liming , Zhang Mengqi 
Published: May 2019

SummaryIn this work, an improved axisymmetric lattice Boltzmann flux solver (LBFS) is proposed for simulation of axisymmetric isothermal and thermal flows. This solver globally resolves the axisymmetric Navier‐Stokes (N‐S) equations through the finite volume strategy and locally reconstructs numerical fluxes with solutions to the lattice Boltzmann equation. Compared with previous axisymmetric LBFS, some novel strategies are adopted in this work to simplify the formulations and improve the accuracy. First, the macroscopic equations are reformulated to reduce the number of source terms and remove spatial derivatives involved in the source terms. Second, the local reconstruction of numerical fluxes utilizes relationships given by the Chapman‐Enskog analysis and combines the radial coordinate (r) with the local solution to the standard LB equation. By adopting these two modifications, the present axisymmetric LBFS avoids the fractional‐step formulation and the finite‐difference approximation adopted in the previous solver, which reduces the complexity of implementation. Moreover, an alternative way of predicting intermediate pressure is proposed, which could effectively fix the inaccurate resolution of the pressure field in previous axisymmetric LBFS. Further extensions are made to enrich the applicability of the present solver in thermal axisymmetric flows. Validations on various benchmark tests are carried out for comprehensive evaluation of the robustness and flexibility of the proposed solver.
The effect of Perilla (Perilla frutescens) leaf extracts on the quality of surimi fish balls
Authors: Zhao Yueliang , Kong Hongyun , Zhang Xu , Hu Xiaoqian , Wang Mingfu 
Published: May 2019

AbstractThe effects of Perilla frutescens leaf extract (PLE) on the quality of surimi fish balls were investigated in the present study. Firstly, the extract was prepared by solvent extraction using 95% ethanol. Then, the phenolics in the extract were analyzed by instrumental analysis. The total phenolic content in the PLE was found to be 14.51 mg gallic acid equivalent (GAE)/g dry weight (DW). The amount of caffeic acid, ferulic acid, rosmarinic acid, quercetin, and apigenin, determined by high‐performance liquid chromatography (HPLC), was 4.80, 5.10, 2.95, 6.46, and 3.93 mg/g DW, respectively. Furthermore, the PLE was found to show high free radical scavenging activity toward DPPH and ABTS radicals with IC50 values of 12.15 and 7.26 μg/ml, respectively. When PLE was fortified into surimi fish balls at 0.03% and stored at 4°C, it was found to slow down lipid and protein oxidation during storage of surimi fish balls as evidenced by the significant reduction in TBARS values and protein carbonyl contents (p < 0.05). PLE (0.03%) also decreased the formation of total volatile basic nitrogen (TVB‐N) and inhibited the growth of E. coli compared with the control group (p < 0.05). In addition, the overall acceptability of PLE‐added (0.03%) samples was higher than control samples during the storage process (p < 0.05) by sensory analysis. Overall, PLE have the potential to be used as a natural food additive to improve the shelf life and sensorial qualities of surimi fish ball.
Formation timing and genesis of Madiu fluorite deposit in East Qinling, China: Constraints from fluid inclusion, geochemistry, and H–O–Sr–Nd isotopes
Authors: Zhao Yu , Pei Qiuming , Zhang Shou‐ting , Guo Guanghua , Li Junjun , Liu Wengang , Hu Xinkai , Song Kairui , Wang Liang 
Published: May 2019

The Heyu fluorite ore district is newly discovered in the East Qinling metallogenic belt (EQMB), central China. In this district, the large Madiu fluorite deposit contains five Mesozoic granite‐hosted orebodies. The deposit may have formed at shallow depth and occurred as continuous veins controlled by a series of N‐S‐ or NE‐trending, steeply dipping faults. The fluorite mineralization can be divided into two stages (I and II). Fluid inclusions in stage I fluorite homogenized at 132.2°C to 342.5°C (peak at 170°C–210°C) with salinities of 0.18 to 4.43 wt% NaCl equiv, whilst those in stage II fluorite homogenized at 122.2°C to 305.7°C (peak at 130°C–170°C) and salinities of 0.18 to 3.71 wt% NaCl equiv. Raman spectroscopic analysis of the fluid inclusions reveals that they comprise predominantly H2O. The rare earth element (REE) characteristics indicate that the deposit is of hydrothermal origin. The δ18OH2O (−8.8‰ to −0.5‰) and δDH2O (−69.0‰ to −61.9‰) values show a subhorizontal trend, suggesting that the oxygen isotopic compositions were modified by fluid–rock interactions. Fluid inclusion and stable isotopic data suggest that the ore‐forming fluids belong to a meteoric water‐sourced, medium–low temperature, and low salinity NaCl–H2O system. Initial fluorite 87Sr/86Sr ratios (0.708879–0.709682) resemble those of the Heyu batholith. The water–rock reaction, which leached Ca from the host rock and increased the fluid pH, was likely causative to the ore precipitation. Geochemical and mineralization features suggest that the Madiu fluorite deposit is best classified as a fault‐controlled hydrothermal vein‐type fluorite deposit. The Sm–Nd isochron age of 118.9 ± 7.8 Ma and its regional age correlation suggest that the fluorite mineralization occurred under regional extension or lithospheric thinning setting and that the fluorite mineralization was an important component of the Early Cretaceous mineralization event in the EQMB.
Converging function, structure, and behavioural features of emotion regulation in very preterm children
Authors: Urbain Charline , Sato Julie , Hammill Christopher , Duerden Emma G. , Taylor Margot J. 
Published: May 2019

AbstractChildren born very preterm (VPT; <32 weeks' gestational age) are at high risk for emotional regulation and social communication impairments. However, the underlying neurobiological correlates of these difficulties remain poorly understood. Using a multimodal approach, including both magnetoencephalographic and structural magnetic resonance imaging, we investigated the functional, structural, and behavioural characteristics of socio‐emotional processing in 19 school‐age children born VPT and 21 age‐matched term‐born (TB) children (7–13 years). Structural MRI analyses were conducted on a subset of these groups (16 VPT and 21 age‐matched TB). Results showed that the inhibition of aversive socio‐emotional stimuli was associated with a sustained reduction of right frontoparietal functional brain activity in children born VPT children. Moreover, whole brain structural analyses showed that reductions of cortical thickness or volume in these regions were associated with poor socio‐emotional performance in children born VPT. Hence, our results suggest that functional and structural alterations encompassing the frontoparietal areas might be a biological marker of less efficient emotion regulation processes/performance in school‐age children born VPT. These findings open up novel avenues to investigate the potential impact of such atypicalities, and in particular, those related to the atypical maturation of the medial prefrontal regions, on the frequent development of psychiatric disorders in this vulnerable population.
Functional connectivity along the anterior–posterior axis of hippocampal subfields in the ageing human brain
Authors: Dalton Marshall A. , McCormick Cornelia , De Luca Flavia , Clark Ian A. , Maguire Eleanor A. 
Published: May 2019

AbstractWhile age‐related volumetric changes in human hippocampal subfields have been reported, little is known about patterns of subfield functional connectivity (FC) in the context of healthy ageing. Here we investigated age‐related changes in patterns of FC down the anterior–posterior axis of each subfield. Using high resolution structural MRI we delineated the dentate gyrus (DG), CA fields (including separating DG from CA3), the subiculum, pre/parasubiculum, and the uncus in healthy young and older adults. We then used high resolution resting state functional MRI to measure FC in each group and to directly compare them. We first examined the FC of each subfield in its entirety, in terms of FC with other subfields and with neighboring cortical regions, namely, entorhinal, perirhinal, posterior parahippocampal, and retrosplenial cortices. Next, we analyzed subfield to subfield FC within different portions along the hippocampal anterior–posterior axis, and FC of each subfield portion with the neighboring cortical regions of interest. In general, the FC of the older adults was similar to that observed in the younger adults. We found that, as in the young group, the older group displayed intrinsic FC between the subfields that aligned with the tri‐synaptic circuit but also extended beyond it, and that FC between the subfields and neighboring cortical areas differed markedly along the anterior–posterior axis of each subfield. We observed only one significant difference between the young and older groups. Compared to the young group, the older participants had significantly reduced FC between the anterior CA1‐subiculum transition region and the transentorhinal cortex, two brain regions known to be disproportionately affected during the early stages of age‐related tau accumulation. Overall, these results contribute to ongoing efforts to characterize human hippocampal subfield connectivity, with implications for understanding hippocampal function and its modulation in the ageing brain.
Testing the Universal Soil Loss Equation‐MB equation in plots in Central and South Italy
Authors: Di Stefano Costanza , Pampalone Vincenzo , Todisco Francesca , Vergni Lorenzo , Ferro Vito 
Published: May 2019

AbstractPlanning soil conservation strategies requires predictive techniques at event scale because a large percentage of soil loss over a long‐time period is due to relatively few large storms. Considering runoff is expected to improve soil loss predictions and allows relation of the process‐oriented approach with the empirical one, furthermore, the effects of detachment and transport on soil erosion processes can be distinguished by a runoff component. In this paper, the empirical model USLE‐MB (USLE‐M based), including a rainfall‐runoff erosivity factor in which the event rainfall erosivity index EI30 of the Universal Soil Loss Equation (USLE) multiplies the runoff coefficient QR raised to an exponent b1 > 1 is tested by the measurements carried out for the Masse (10 plots) and Sparacia (22 plots) experimental stations in Italy. For the Masse experimental station, an exponent b1 > 1 was also estimated by tests carried out by a nozzle‐type rainfall simulator. For each experimental site in fallow conditions, the effect of the sample size of the plot soil loss measurements on the estimate of the b1 coefficient was also studied by the extraction of a fixed number N of randomly obtained pairs of the normalized soil loss and runoff coefficient. The analysis showed that the variability of b1 with N is low and that 350 pairs are sufficient to obtain a stable estimate of b1. A total of 1,262 soil loss data were used to parameterize the model both locally and considering the two sites simultaneously. The b1 exponent varied between the two sites (1.298–1.520), but using a common exponent (1.386) was possible. Using a common b1 exponent for the two experimental areas increases the practical interest for the model and allows the estimation of a baseline component of the soil erodibility factor, which is representative of the at‐site soil intrinsic and quasi‐static properties. Development of a single USLE‐MB model appears possible, and sampling other sites is advisable to develop a single USLE‐MB model for general use.
A district‐wide population‐based descriptive study of emergency peripartum hysterectomy in a middle‐income country
Authors: Heitkamp Anke , Seinstra Jorrit , van den Akker Thomas , Vollmer Linda , Gebhardt Stefan , van Roosmalen Jos , de Vries Johanna I. , Theron Gerhard 
Published: May 2019

AbstractObjectiveTo determine incidence, risk indicators, and outcomes of emergency peripartum hysterectomy (EPH) in Metro East, Cape Town, South Africa.MethodsA population‐based district‐wide prospective descriptive study of EPH in public hospitals from November 2014 to November 2015. Women were enrolled by using the WHO maternal near miss tool and followed until discharge. EPH was defined as hemorrhage or infection leading to hysterectomy during pregnancy or within 42 days of delivery.ResultsFifty‐nine women experienced EPH with an overall incidence of 14.3 per 10 000 women: 32 procedures were for postpartum hemorrhage, 27 for puerperal sepsis. Two women died: one from sepsis; one from hemorrhage. Overall, 51 (86%) women delivered by cesarean, and 23/51 (45%) by repeat cesarean. As compared with hemorrhage, EPH for sepsis involved older women (mean age, 31.5 vs 24.4 years) and those with higher gravidity (median, 3 vs 1), and was associated with longer hospital admission (median, 11.5 vs 4 days), with occurrence later postpartum (median, 8 vs 0 days), and more frequently with complications.ConclusionsThe incidence of EPH for sepsis was higher than previously reported. Repeat cesarean was strongly associated with EPH. Clinical characteristics of sepsis‐related EPH compared unfavorably with those of hemorrhage‐related EPH.