bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of particle stock and phytoplankton community structure in regulating particulate organic carbon export in a large marginal sea
Authors: Cai Pinghe , Zhao Daochen , Wang Lei , Huang Bangqin , Dai Minhan 
Published: February 2015

AbstractIn this study, we utilize 234Th/238U disequilibrium to determine particulate organic carbon (POC) export from the euphotic zone in the South China Sea. Depth profiles of 234Th, total chlorophyll, pigments, and POC were collected during four cruises from August 2009 to May 2011, covering an entire seasonal cycle of spring, summer, autumn, and winter. The extensive data set that was acquired allows for an evaluation of the seasonal variability of upper ocean POC export and its controls in a large marginal sea. The results show that 234Th fluxes from the euphotic zone fall in the range of 528−1550, 340−2694, and 302–2647 dpm m−2 d−1 for the coastal, shelf, and basin regimes, respectively. In these regimes, POC/234Th ratios at the base of the euphotic zone fall in the range of 5.7–58.2, 4.6–44.0, and 2.5–15.5 μmol dpm−1, respectively. Accordingly, for the coastal, shelf, and basin regimes, the mean POC export fluxes from the euphotic zone are 24.3, 18.3, and 6.3 mmolC m−2 d−1, respectively. Seasonal variations in POC export flux are remarkable in the study area, and POC export peaks were generally observed in autumn. We use a simple linear regression (LLS) method to examine the correlation of POC export versus POC stock and versus plankton community structure. We found a strong correlation (R2 = 0.73, p < 0.005) between POC export flux and the fraction of diatom in the coastal area, indicating that POC export flux in this province is driven by large phytoplankton, in particular, diatoms. In the shelf area, a relatively strong correlation (R2 = 0.54, p < 0.0001) was noted for POC export flux and POC stock in the euphotic zone. This indicates that POC export flux in the South China Sea shelf is primarily controlled by POC stock. In contrast, in the South China Sea basin, we identified a weak but intriguing correlation (R2 = 0.26, p < 0.0001) between POC export flux and the fraction of haptophytes and prasinophytes that are typically < 5 μm in size. This suggests that mechanisms controlling POC export flux in the South China Sea basin are complicated. However, small phytoplankton may play a significant role in controlling POC export flux since they dominate the phytoplankton community structure in this region.
On the transport modes of fine sediment in the wave boundary layer due to resuspension/deposition: A turbulence‐resolving numerical investigation
Authors: Cheng Zhen , Yu Xiao , Hsu Tian‐Jian , Ozdemir Celalettin E. , Balachandar S. 
Published: February 2015

AbstractPrevious field observations revealed that the wave boundary layer is one of the main conduits delivering fine sediments from the nearshore to continental shelves. Recently, a series of turbulence‐resolving simulations further demonstrated the existence of a range of flow regimes due to different degrees of sediment‐induced density stratification controlled by the sediment availability. In this study, we investigate the scenario in which sediment availability is governed by the resuspension/deposition from/to the bed. Specifically, we focus on how the critical shear stress of erosion and the settling velocity can determine the modes of transport. Simulations reveal that at a given wave intensity, which is associated with more energetic muddy shelves and a settling velocity of about 0.5 mm/s, three transport modes, ranging from the well‐mixed transport (mode I), two‐layer like transport with the formation of lutocline (mode II), and laminarized transport (mode III) are obtained as the critical shear stress of erosion reduces. Moreover, reductions in the settling velocity also yield similar transitions of transport modes. We also demonstrate that the onset of laminarization can be well explained by the reduction of wave‐averaged bottom stress to about 0.39 Pa due to attenuated turbulence by sediments. A 2‐D parametric map is proposed to characterize the transition from one transport mode to another as a function of the critical shear stress and the settling velocity at a fixed wave intensity.
A model for subglacial flooding through a preexisting hydrological network during the rapid drainage of supraglacial lakes
Authors: Adhikari S. , Tsai V. C. 
Published: February 2015

AbstractIncreasingly large numbers of supraglacial lakes form and drain every summer on the Greenland Ice Sheet. Some of these lakes drain rapidly within the timescale of a few hours, and the vertical discharge of water during these events may find a preexisting film of water potentially within a distributed drainage system of linked cavities. Here we present a model for subglacial flooding applied specifically to such circumstances. One of many interesting results we find is that water flows in from the far field prior to the arrival of flooding. We systematically evaluate the effect of initial ice/bed opening on the degree of perturbation to the subglacial system. Of particular importance, we find that floods propagate much faster and vertical displacements are much greater for larger openings. For 10 and 1 cm of initial opening, for example, floods travel about 68% and 50% farther than in the fully coupled ice/bed scenario after 2 h of drainage, respectively. For the same choices of initial opening, the elastostatic displacement at the injection point is about 1.39 and 1.26 times that of the fully coupled scenario. Using the framework with a preexisting water film results in avoiding the pressure singularity that is inherent to classical hydrofracture models, thus opening an avenue for integrating the likes of our model within continuum subglacial hydrological models. Furthermore, we foresee that the theory presented can be used to potentially infer subglacial hydrological conditions from surface observables.
The relationship of conodont biofacies to spatially variable water mass properties in the Late Pennsylvanian Midcontinent Sea
Authors: Herrmann Achim D. , Barrick James E. , Algeo Thomas J. 
Published: February 2015

AbstractMolybdenum and uranium enrichment factors and nitrogen isotopes suggest that an interplay of open ocean upwelling and riverine runoff led to distinct spatial and secular variations in water mass properties within the epicontinental Late Pennsylvanian Midcontinent Sea of North America. In particular, the intensity of continental runoff influenced the flux of bulk organic matter to the sediment. Benthic anoxia appears to have been controlled by the vertical density gradient in the water column associated with continental runoff combined with the advection of basinal water. Anoxic conditions were stronger in proximal (i.e., more shoreward) areas of the Midcontinent Shelf, indicating that anoxia did not develop primarily due to upwelling of nutrient‐rich waters along the southern shelf margin, as previously suggested. Changes in water mass redox conditions not only drove authigenic enrichment of redox‐sensitive trace elements across the basin but also had a strong effect on the spatial distribution of various conodont taxa. Our analysis suggests that the widely accepted depth‐stratification model for the distribution of conodonts is incomplete. Conodont biofacies distributions seem to have been controlled by physicochemical properties of the water mass (e.g., salinity, temperature, nutrients, turbidity, and/or dissolved oxygen levels) that may correspond less directly to water depth. The proximity to terrestrial freshwater influx and the strength of anoxia/euxinia in the subpycnoclinal water mass played significant roles in the spatial and temporal distributions of conodont taxa.
Developmental Trends in False Memory Across Adolescence and Young Adulthood: A Comparison of DRM and Memory Conformity Paradigms
Authors: McGuire Katherine , London Kamala , Wright Daniel B. 
Published: February 2015

SummaryLittle is known about the reliability of eyewitness memory among adolescents as most memory research has focused primarily on adults and young children. A number of studies recently have emerged outlining conditions where memory suggestibility increases from early childhood to adulthood. These developmental reversals are found in semantic association tasks such as the Deese–Roediger–McDermott (DRM) paradigm and have not yet been thoroughly investigated among adolescents. In the current study, we examined DRM performance among 11–21 year olds (N = 245). Extending the work comparing children and adults, false memory on the DRM task increased with age. False memory on the DRM task was not associated with false memory on a memory conformity task. The different memory processes involved with the tasks and the implications for legal psychology are discussed. Copyright © 2015 John Wiley & Sons, Ltd.
Preparation of hydrophilic polysulfone membrane using polyacrylic acid with polyvinyl pyrrolidone
Authors: Sharma Nilay , Purkait Mihir Kumar 
Published: February 2015

ABSTRACTThis study examined the consequences of the addition of polyvinyl pyrrolidone (PVP) of different molecular weights with constant molecular weight of polyacrylic acid (PAA) on the morphology and permeation properties of polysulfone (PSF) membranes. The asymmetric polymeric membranes were prepared by phase inversion process using PSF in N‐methyl‐2‐pyrrolidone (NMP) as a solvent. The surface structure and morphology of the prepared membranes were analyzed by field‐emission scanning electron microscope (FESEM) and atomic force microscopy (AFM). The pore number, average pore size and area of pores for all the membranes were determined by permeability method. These ultrafiltration membranes were subjected to characterizations such as measurement of pure water flux (PWF), compaction factor (CF), bovine serum albumin (BSA) rejection for finding the permeability performance, whereas equilibrium water content, contact angle, porosity, hydraulic resistance, and ion exchange capacity (IEC) are measured for evaluating the hydrophilicity. Results demonstrate that the flux performance of the membranes and morphological parameters own a crucial inter‐relationship with the molecular weight of PVP. The membrane pore area and pore number were found to be increased by increasing molecular weight of PVP with constant molecular weight of PAA. A detailed comparative study was done with Chakrabarty et al. (J. Membr. Sci. 2008, 309, 209) and found better in almost all the aspects. All the resulting parameters were compared and concluded with the fact that addition of small amount of PAA in PSF/PVP/NMP casting solution can be better than addition of PVP alone. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41964.
Bio‐nanocomposite films based on cellulose nanocrystals filled polyvinyl alcohol/chitosan polymer blend
Authors: El Miri Nassima , Abdelouahdi Karima , Zahouily Mohamed , Fihri Aziz , Barakat Abdellatif , Solhy Abderrahim , El Achaby Mounir 
Published: February 2015

ABSTRACTBio‐nanocomposite films based on polyvinyl alcohol/chitosan (PVA/CS) polymeric blend and cellulose nanocrystals (CNC) were prepared by casting a homogenous and stable aqueous mixture of the three components. CNC used as nanoreinforcing agents were extracted at the nanometric scale from sugarcane bagasse via sulfuric acid hydrolysis; then they were characterized and successfully dispersed into a PVA/CS (50/50, w/w) blend to produce PVA/CS–CNC bio‐nanocomposite films at different CNC contents (0.5, 2.5, 5 wt %). Viscosity measurement of the film‐forming solutions and structural and morphological characterizations of the solid films showed that the CNC are well dispersed into PVA/CS blend forming strong interfacial interactions that provide an enhanced load transfer between polymer chains and CNC, thus improving their properties. The obtained bio‐nanocomposite films are mechanically strong and exhibit improved thermal properties. The addition of 5 wt % CNC within a PVA/CS blend increased the Young's modulus by 105%, the tensile strength by 77%, and the toughness by 68%. Herein, the utilization of Moroccan sugarcane bagasse as raw material to produce high quality CNC has been explored. Additionally, the ability of the as‐isolated CNC to reinforce polymer blends was studied, resulting in the production of the aforementioned bio‐nanocomposite films with improved properties. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42004.
Flame retardancy and mechanical properties of pet‐based composites containing phosphorus and boron‐based additives
Authors: Kilinc Mert , Cakal Gaye O. , Bayram Goknur , Eroglu Inci , Özkar Saim 
Published: February 2015

ABSTRACTFlame retardancy of poly(ethylene terephthalate), PET, was improved using different flame retardant additives such as triphenylphosphate, triphenylphosphine oxide, zinc borate, and boron phosphate (BP). Composites were prepared using a twin screw extruder and subsequently injection molded for characterization purposes. The flame retardancy of the composites was determined by the limiting oxygen index (LOI) test. Smoke emission during fire was also evaluated in terms of percent light transmittance. Thermal stability and tensile properties of PET‐based composites were compared with PET through TGA and tensile test, respectively. The LOI of the flame retardant composites increased from 21% of neat PET, up to 36% with the addition of 5% BP and 5% triphenyl phosphate to the matrix. Regarding the smoke density analysis, BP was determined as an effective smoke suppressant for PET. Enhanced tensile properties were obtained for the flame retardant PET‐based composites with respect to PET. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42016.
Polyglycidyl nitrate (PGN)‐based energetic thermoplastic polyurethane elastomers with bonding functions
Authors: Zhang Zaijuan , Luo Nan , Wang Zhen , Luo Yunjun 
Published: February 2015

ABSTRACTPGN‐based ETPUEs were synthesized using mixture of chain extenders including 1, 4‐butanediol and Diethyl Bis(hydroxymethyl)malonate (DBM). Through the special chain extenders DBM, the –COOR was introduced into the energetic thermoplastic polyurethane elastomers (ETPUEs) and further enhances the adhesion between ETPUE and nitramine solid ingredients in propellants. From the analysis, with the percentage of DBM increasing, the work of adhesion (Wa) between nitramine solid ingredients and ETPUEs increased and the maximum stress (σm) of ETPUEs decreased on the other hand. In order to test the bonding functions of different ETPUEs, the RDX/ETPUE propellants were prepared and the stress–strain curves of all propellants were tested. The results showed that the ETPUE‐75 with 75% DBM can prevent the dewetting and improve the mechanical properties of propellants. The ETPUE prepared with chain extender including 1, 4‐butanediol and DBM were valuable for application in propellants. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2015,132, 42026.
Green nanocomposites filled with spent coffee grounds
Authors: Lee Hyun Kyung , Park Young Gi , Jeong Taikyeong , Song Young Seok 
Published: February 2015

ABSTRACTThis study evaluated physical properties of the nanocomposites reinforced by used coffee grounds. Coffee grounds were ball‐milled and filtered in an effort to secure nanoparticles for the fabrication of polyvinyl alcohol (PVA)/coffee nanocomposites. We analyzed the particle size distribution of coffee particles and investigated mechanical and optical properties of the prepared nanocomposites. Carbon black (CB)‐filled nanocomposites were also prepared to understand the physical behavior of the nanocomposites reinforced with coffee grounds and to explore the possibility of replacing CBs with nanosized coffee grounds used as a composite filler. It was found that the tensile strength and Young's modulus of PVA/coffee grounds nanocomposites were significantly enhanced compared with those of the PVA/CB nanocomposites. In addition, morphological observation for the nanocomposites was carried out using scanning electron microscopy (SEM). © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42043.
Overexpression of the microRNA miR‐433 promotes resistance to paclitaxel through the induction of cellular senescence in ovarian cancer cells
Authors: Weiner‐Gorzel Karolina , Dempsey Eugene , Milewska Malgorzata , McGoldrick Aloysius , Toh Valerie , Walsh Aoibheann , Lindsay Sinead , Gubbins Luke , Cannon Aoife , Sharpe Daniel , O'Sullivan Jacintha , Murphy Madeline , Madden Stephen F. , Kell Malcolm , McCann Amanda , Furlong Fiona 
Published: February 2015

AbstractAnnually, ovarian cancer (OC) affects 240,000 women worldwide and is the most lethal gynecological malignancy. High‐grade serous OC (HGSOC) is the most common and aggressive OC subtype, characterized by widespread genome changes and chromosomal instability and is consequently poorly responsive to chemotherapy treatment. The objective of this study was to investigate the role of the microRNA miR‐433 in the cellular response of OC cells to paclitaxel treatment. We show that stable miR‐433 expression in A2780 OC cells results in the induction of cellular senescence demonstrated by morphological changes, downregulation of phosphorylated retinoblastoma (p‐Rb), and an increase in β‐galactosidase activity. Furthermore, in silico analysis identified four possible miR‐433 target genes associated with cellular senescence: cyclin‐dependent kinase 6 (CDK6), MAPK14, E2F3, and CDKN2A. Mechanistically, we demonstrate that downregulation of p‐Rb is attributable to a miR‐433‐dependent downregulation of CDK6, establishing it as a novel miR‐433 associated gene. Interestingly, we show that high miR‐433 expressing cells release miR‐433 into the growth media via exosomes which in turn can induce a senescence bystander effect. Furthermore, in relation to a chemotherapeutic response, quantitative real‐time polymerase chain reaction (qRT‐PCR) analysis revealed that only PEO1 and PEO4 OC cells with the highest miR‐433 expression survive paclitaxel treatment. Our data highlight how the aberrant expression of miR‐433 can adversely affect intracellular signaling to mediate chemoresistance in OC cells by driving cellular senescence.
Preparative Enantioseparation of (RS)‐Baclofen: Determination of Molecular Dissymmetry
Authors: Vashistha Vinod Kumar , Bhushan Ravi 
Published: February 2015

AbstractThe present work reports preparative enantioseparation of (RS)‐baclofen using thin‐layer chromatography (TLC) and high‐performance liquid chromatography (HPLC). Diastereomers were synthesized using a new monochloro‐s‐triazine‐based chiral derivatizing reagent (CDR), namely, N‐(4‐chloro‐6‐piperidinyl‐[1,3,5]‐triazine‐2‐yl)‐L‐phenylalanine, under microwave irradiation. Acetonitrile‐0.1% aq. triflouroacetic acid in gradient elution mode and CH3OH‐CH2Cl2 (4:5; v/v) were successful as mobile phase in HPLC and TLC, respectively. The two diastereomers were isolated by preparative TLC. Molecular dissymmetry was established by developing the lowest energy optimized structures of the diastereomers based on Density Functional Theory and with the help of 1H NMR showing anisotropic effect associated with aromatic ring of s‐triazine (in the CDR). The configuration of diastereomers was established as [L‐Phe‐(R)‐Bac] and [L‐Phe‐(S)‐Bac], where the first notation refers to the configuration of chiral auxiliary (of the CDR) and the second to that of the analyte Bac. Limits of detection were found to be 0.056 and 0.061 ng mL−1, respectively, for the two diastereomers. Determination of absolute configuration of the two diastereomers lent support to the elution order and separation mechanism.Chirality 27:299–305, 2015. © 2015 Wiley Periodicals, Inc.
Preferential Enrichment of DL‐Leucine Using Cocrystal Formation With Oxalic Acid Under Nonequilibrium Crystallization Conditions
Authors: Manoj Kochunnoonny , Takahashi Hiroki , Morita Yoko , Gonnade Rajesh G. , Iwama Sekai , Tsue Hirohito , Tamura Rui 
Published: February 2015

AbstractBy utilizing the preferential enrichment (PE) technique, we achieved an improved enantiomeric resolution of DL‐leucine (Leu) using a 1:1 cocrystal (DL‐1) of DL‐Leu and oxalic acid. The crystal structure analysis of DL‐1 indicated the occurrence of a novel type of phase transition and subsequent preferential redissolution of one enantiomer from the resulting crystals into solution. Chirality 27:405–410 2015. © 2015 Wiley Periodicals, Inc.
Complex offspring size effects: variations across life stages and between species
Authors: Sun Zhao , Hamel Jean‐François , Parrish Christopher C. , Mercier Annie 
Published: February 2015

AbstractClassical optimality models of offspring size and number assume a monotonically increasing relationship between offspring size and performance. In aquatic organisms with complex life cycles, the size–performance function is particularly hard to grasp because measures of performance are varied and their relationships with size may not be consistent throughout early ontogeny. Here, we examine size effects in premetamorphic (larval) and postmetamorphic (juvenile) stages of brooding marine animals and show that they vary contextually in strength and direction during ontogeny and among species. Larger offspring of the sea anemone Urticina felina generally outperformed small siblings at the larval stage (i.e., greater settlement and survival rates under suboptimal conditions). However, results differed when analyses were conducted at the intrabrood versus across‐brood levels, suggesting that the relationship between larval size and performance is mediated by parentage. At the juvenile stage (15 months), small offspring were less susceptible than large ones to predation by subadult nudibranchs and both sizes performed similarly when facing adult nudibranchs. In a sympatric species with a different life history (Aulactinia stella), all juveniles suffered similar predation rates by subadult nudibranchs, but smaller juveniles performed better (lower mortalities) when facing adult nudibranchs. Size differences in premetamorphic performance of U. felina were linked to total lipid contents of larvae, whereas size‐specific predation of juvenile stages followed the general predictions of the optimal foraging strategy. These findings emphasize the challenge in gathering empirical support for a positive monotonic size–performance function in taxa that exhibit complex life cycles, which are dominant in the sea.