bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compensation of the Meyer‐Neldel Compensation Law for H diffusion in minerals
Authors: Jones Alan G. 
Published: May 2014

AbstractThe Meyer‐Neldel Rule (MNR), or compensation law, linearly relates the preexponent term to the logarithm of the excitation enthalpy for any process that is thermally driven in an Arrhenian manner, and MNR fits can be used to calibrate and validate laboratory experimental results. Both robust least squares linear regressions and nonrobust regressions on selected subsets for individual minerals with sufficient experimental data demonstrate that hydrogen diffusion in minerals obeys the MNR with differing MNR intercepts and gradients depending on the mineral. In particular, nominally anhydrous mantle minerals have very distinct and different MNR parameters compared to hydrous and crustal minerals, with garnet proving to be an outlier lying in between the two. Furthermore, the variations of the estimated intercepts and gradients of the various MNRs are not random, but remarkably they themselves fall on a striking linear trend. This observation, if more broadly true, has profound implications for materials sciences and understanding of solid‐state physics, as it implies that the compensation rule is itself compensated.
Paleointensity of the geomagnetic field in the Late Cretaceous and earliest Paleogene obtained from drill cores of the Louisville seamount trail
Authors: Yamazaki Toshitsugu , Yamamoto Yuhji 
Published: May 2014

AbstractInformation on the strength of the geomagnetic field is important for understanding the behavior of the geodynamo. Polarity reversal frequency increases toward the late Cenozoic since the end of the Cretaceous Normal Superchron. Accumulating reliable paleointensity data in this time interval is still desired for elucidating the possibility of a link between reversal frequency and paleointensity. We conducted a paleointensity study on 288 samples from four seamounts from ∼74 to ∼50 Ma in age that constitutes the Louisville seamount trail. Based on thermomagnetic curves and scanning electron microscopy, we first excluded 134 samples that showed evidence for low‐temperature oxidation. We then applied the Tsunakawa‐Shaw method with low‐temperature demagnetization and double heating after rejecting some samples that do not preserve stable primary remanence, and 52 successful results were obtained. An average virtual axial dipole moment (VADM) of 3.75 ± 1.52 (1022 Am2) was obtained at Site U1372 on Canopus seamount (∼74 Ma) based on 16 independent measurements. Sites U1373 and U1374 on Rigil seamount (∼70 Ma) yielded a mean of 3.79 ± 1.40 (n = 16), and Site U1376 on Burton seamount (∼65 Ma) yielded a mean of 3.70 ± 1.37 (n = 8). These VADMs are similar to the long‐term average of the last 200 Myr by Tauxe et al. (2013) and the mean of the last 5 Myr by Yamamoto and Tsunakawa (2005). The volcanic sequence drilled at Site U1372 probably belongs to Chron C33n of 5.59 Myr long, whereas others belong to shorter chrons. Our results support no discernible relationship between polarity length and paleointensity.
Global magnetodisk disturbances and energetic particle injections at Jupiter
Authors: Louarn Philippe , Paranicas Christopher P. , Kurth William S. 
Published: May 2014

AbstractMeasurements made by the Galileo Energetic Particles Detector and the plasma wave/radio instrument are analyzed to establish relationships between dynamic processes observed independently in the distant and the inner Jovian disk (at 80–120 Jovian radii (RJ) and 10–25 RJ, respectively). It is first shown that global magnetospheric disturbances identified from the radio emissions (the “energetic events” are well correlated with reconnection/reconfiguration events observed at the outer edge of the disk. Then, considering all Galileo perijoves, it is also demonstrated that the energetic events occurring as Galileo was at less than ~25 RJ are systematically associated with new injections of energetic particles seen from ~10 to 25 RJ. This demonstrates that major disturbances commonly affect the whole magnetodisk, from 10 to 80–120 RJ. Overall, their phenomenology involves simultaneous auroral activation, formation of new sources of radio emission (narrow‐band kilometric radiation) and particle injections in the Io torus, magnetic reconfigurations, and radial flow bursts in the distant disk, over time scale of a few hours.
MESSENGER observations of large dayside flux transfer events: Do they drive Mercury's substorm cycle?
Authors: Imber Suzanne M. , Slavin James A. , Boardsen Scott A. , Anderson Brian J. , Korth Haje , McNutt Ralph L. , Solomon Sean C. 
Published: May 2014

AbstractThe large‐scale dynamic behavior of Mercury's highly compressed magnetosphere is predominantly powered by magnetic reconnection, which transfers energy and momentum from the solar wind to the magnetosphere. The contribution of flux transfer events (FTEs) at the dayside magnetopause to the redistribution of magnetic flux in Mercury's magnetosphere is assessed with magnetic field data acquired in orbit about Mercury by the Magnetometer on the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft. FTEs with core fields greater than the planetary field just inside the magnetopause are prevalent at Mercury. Fifty‐eight such large‐amplitude FTEs were identified during February and May 2012, when MESSENGER sampled the subsolar magnetosheath. The orientation of each FTE was determined by minimum variance analysis, and the magnetic flux content of each was estimated using a force‐free flux rope model. The average flux content of the FTEs was 0.06 MWb, and their durations imply a transient increase in the cross‐polar cap potential of ~25 kV. For a substorm timescale of 2–3 min, as indicated by magnetotail flux loading and unloading, the FTE repetition rate (10 s) and average flux content (assumed to be 0.03 MWb) imply that FTEs contribute at least ~30% of the flux transport required to drive the Mercury substorm cycle. At Earth, in contrast, FTEs are estimated to contribute less than 2% of the substorm flux transport. This result implies that whereas at Earth, at which steady‐state dayside reconnection is prevalent, multiple X‐line dayside reconnection and associated FTEs at Mercury are a dominant forcing for magnetospheric dynamics.
Managing flow, sediment, and hydropower regimes in the Sre Pok, Se San, and Se Kong Rivers of the Mekong basin
Authors: Wild Thomas B. , Loucks Daniel P. 
Published: May 2014

AbstractThe Lancang/Mekong River Basin is presently undergoing a period of rapid hydropower development. In its natural undeveloped state, the river transports about 160 million metric tons of sediment per year, maintaining the geomorphologic features of the basin, sustaining habitats, and transporting the nutrients that support ecosystem productivity. Despite the importance of sediment in the river, currently little attention is being paid to reservoir sediment trapping. This study is devoted to assessing the potential for managing sediment and its impact on energy production in the Se San, Sre Pok, and Se Kong tributaries of the Mekong River. These tributaries drain a set of adjacent watersheds that are important with respect to biodiversity and ecological productivity, and serve as a significant source of flow and sediment to the mainstream Mekong River. A daily sediment transport model is used to assess tradeoffs among energy production and sediment and flow regime alteration in multiple reservoir systems. This study finds that eventually about 40%–80% of the annual suspended sediment load may be trapped in reservoirs. Clearly, these reservoirs will affect the rivers' sediment regimes. However, even after 100 years of simulated sedimentation, reservoir storage capacities and hydropower production at most reservoir sites are not significantly reduced. This suggests that the strongest motivation for implementing measures to reduce trapped sediment is their impact not on hydropower production but on fish migration and survival and on sediment‐dependent ecosystems such as the Vietnam Delta and Cambodia's Tonle Sap Lake.
Brief communication: The size of the human frontal sinuses in adults presenting complete persistence of the metopic suture
Authors: Guerram Amine , Le Minor Jean‐Marie , Renger Stéphane , Bierry Guillaume 
Published: May 2014

ABSTRACTThe notion of absence of the frontal sinuses in human individuals presenting a persistence of the metopic suture is considered as classical in many treatises of reference; however, precise studies are very rare and even controversial. The purpose of this study was thus to provide original data to confirm or refute this classical affirmation with the perspective of some original insights into biological significance of the frontal sinuses and the factors influencing their exceptional polymorphism. The material consisted of 143 dry skulls of adult individuals (European Homo sapiens), distributed in two groups: 80 skulls presenting a complete frontal closure with total disappearance of the metopic suture, and 63 skulls presenting a complete persistence of the metopic suture. Each skull was radiographed in oblique projection using the occipitomental view. A simple morphological quantification of the sinus size was defined with four categories: (1) aplasia, (2) hypoplasia, (3) medium size, (4) hyperplasia. Statistically significant difference in frontal sinusal size was found between both groups of skulls. Absent and small sinuses were considerably more frequent in skulls with persistence of the metopic suture (57.9 vs. 11.9%): small frontal sinuses (hypoplasia) were much more frequent (50.8 vs. 9.4%), although the frequency of absence of frontal sinuses (aplasia) was only slightly higher (7.1 vs. 2.5%). Am J Phys Anthropol 154:621–627, 2014. © 2014 Wiley Periodicals, Inc.
Polyhexamethylene guanidine hydrochloride shows bactericidal advantages over chlorhexidine digluconate against ESKAPE bacteria
Authors: Zhou Zhongxin , Wei Dafu , Lu Yanhua 
Published: May 2014

AbstractMore information regarding the bactericidal properties of polyhexamethylene guanidine hydrochloride (PHMG) against clinically important antibiotic‐resistant ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens needs to be provided for its uses in infection control. The bactericidal properties of PHMG and chlorhexidine digluconate (CHG) were compared based on their minimum inhibitory concentrations (MICs), minimum bactericidal concentrations, and time‐course–killing curves against clinically important antibiotic‐susceptible and antibiotic‐resistant ESKAPE pathogens. Results showed that PHMG exhibited significantly higher bactericidal activities against methicillin‐resistant Staphylococcus aureus, carbapenem‐resistant Klebsiella pneumoniae, and ceftazidime‐resistant Enterobacter spp. than CHG. A slight bactericidal advantage over CHG was obtained against vancomycin‐resistant Enterococcus faecium, ciprofloxacin‐ and levofloxacin‐resistant Acinetobacter spp., and multidrug‐resistant Pseudomonas aeruginosa. In previous reports, PHMG had higher antimicrobial activity against almost all tested Gram‐negative bacteria and several Gram‐positive bacteria than CHG using MIC test. These studies support the further development of covalently bound PHMG in sterile‐surface materials and the incorporation of PHMG in novel disinfectant formulas.
Enhancement of ginsenoside biosynthesis and secretion by Tween 80 in Panax ginseng hairy roots
Authors: Liang Yanlong , Wu Jianjun , Li Yao , Li Jian , Ouyang Yong , He Zhi , Zhao Shoujing 
Published: May 2014

AbstractWe evaluated the effect of Tween 80 permeabilization on ginsenoside secretion in Panax ginseng hairy roots. Tween 80 (1.2%, w/v) had no significant effect on hairy root vitality. After a 25‐day treatment with Tween 80, approximately 76% of the total ginsenosides was released into the surrounding medium. In the case of control, the ginsenosides secreted into the medium were negligible. Furthermore, when compared with control, the level of total ginsenosides was enhanced by approximately threefold under Tween treatment. Additionally, secretion of the typical ginsenoside monomers including Rb1, Rg1, and Re was analyzed, indicating that the most of them were released into the medium. Moreover, it was observed that dammarenediol synthase, a key enzyme involved in ginsenoside biosynthesis, was upregulated at both gene expression and enzyme activity levels. The expression of genes CYP716A47 and CYP716A53v2 encoding Cyt P450 enzymes catalyzing the formation of protopanaxadiol from dammarenediol and protopanaxatriol from protopanaxadiol, respectively, was slightly upregulated. These results clearly demonstrated that Tween 80 could act not only as an efficient permeabilizer to enhance ginsenoside secretion from the hairy roots, but also as an elicitor to promote the biosynthesis of ginsenoside.
CD and NMR conformational studies of a peptide encompassing the Mid Loop interface of Ship2–Sam
Authors: Mercurio Flavia A. , Scognamiglio Pasqualina L. , Di Natale Concetta , Marasco Daniela , Pellecchia Maurizio , Leone Marilisa 
Published: May 2014

ABSTRACTThe lipid phosphatase Ship2 is a protein that intervenes in several diseases such as diabetes, cancer, neurodegeneration, and atherosclerosis. It is made up of a catalytic domain and several protein docking modules such as a C‐terminal Sam (Sterile alpha motif) domain. The Sam domain of Ship2 (Ship2–Sam) binds to the Sam domains of the EphA2 receptor (EphA2–Sam) and the PI3K effector protein Arap3 (Arap3–Sam). These heterotypic Sam–Sam interactions occur through formation of dimers presenting the canonical “Mid Loop/End Helix” binding mode. The central region of Ship2–Sam, spanning the C‐terminal end of α2, the α3 and α4 helices together with the α2α3 and α3α4 interhelical loops, forms the Mid Loop surface that is needed to bind partners Sam domains. A peptide encompassing most of the Ship2–Sam Mid Loop interface (Shiptide) capable of binding to both EphA2–Sam and Arap3–Sam, was previously identified. Here we investigated the conformational features of this peptide, through solution CD and NMR studies in different conditions. These studies reveal that the peptide is highly flexible in aqueous buffer, while it adopts a helical conformation in presence of 2,2,2‐trifluoroethanol. The discovered structural insights and in particular the identification of a helical motif, may lead to the design of more constrained and possibly cell permeable Shiptide analogs that could work as efficient antagonists of Ship2–Sam heterotypic interactions and embrace therapeutic applications. © 2014 Wiley Periodicals, Inc. Biopolymers 101: 1088–1098, 2014.
Bacterial community structure and activity of sulfate reducing bacteria in a membrane aerated biofilm analyzed by microsensor and molecular techniques
Authors: Liu Hong , Tan Shuying , Sheng Zhiya , Liu Yang , Yu Tong 
Published: May 2014

ABSTRACTThe activities and vertical spatial distribution of sulfate reducing bacteria (SRB) in an oxygen (O2)‐based membrane aerated biofilm (MAB) were investigated using microsensor (O2 and H2S) measurements and molecular techniques (polymerase chain reaction‐denaturing gradient gel electrophoresis [PCR‐DGGE] and fluorescence in situ hybridization [FISH]). The O2 concentration profile revealed that O2 penetrated from the bottom (substratum) of the gas permeable membrane, and was gradually consumed within the biofilm until it was completely depleted near the biofilm/bulk liquid interface, indicating oxic and anoxic zone in the MAB. The H2S concentration profile showed that H2S production was found in the upper 285 µm of the biofilm, indicating a high activity of SRB in this region. The results from DGGE of the PCR‐amplified dissimilatory sulfite reductase subunit B (dsrB) gene and FISH showed an uneven spatial distribution of SRB. The maximum SRB biomass was located in the upper biofilm. The information from the molecular analysis can be supplemented with that from microsensor measurements to better understand the microbial community and activity of SRB in the MAB. Biotechnol. Bioeng. 2014;111: 2155–2162. © 2014 Wiley Periodicals, Inc.
Construction of a yeast‐based signaling biosensor for human angiotensin II type 1 receptor via functional coupling between Asn295‐mutated receptor and Gpa1/Gi3 chimeric Gα
Authors: Nakamura Yasuyuki , Ishii Jun , Kondo Akihiko 
Published: May 2014

ABSTRACTAngiotensin II (Ang II) type 1 receptor (AGTR1) is a G‐protein‐coupled receptor (GPCR). Its natural ligand, Ang II, is an important effector molecule controlling blood pressure and volume in the cardiovascular system, and is consequently involved in various diseases such as hypertension and heart failure. Thus, the signaling mediator, AGTR1, is a significant molecular target in medicinal and therapeutic fields. Yeast is a useful organism for sensing GPCR signaling because it provides a simplified version of the complicated machinery used by mammalian cells for signal transduction. Although yeast cells can successfully transmit a signal through a variety of human GPCRs expressed in the cell membrane, there have been no reports of the functional activation of AGTR1‐mediated signaling in yeast cells. In the present study, we introduced a single mutation into human AGTR1 and used yeast‐human chimeric Gα to exert the functional activation of AGTR1 in yeast cells. The engineered yeast cells expressing AGTR1 mutated at Asn295 and the chimeric Gα successfully transmitted the signal inside the yeast cells in response to Ang II peptide and its analogs (Ang III and Ang IV peptides) added to the assay medium. Further, we demonstrated that the autocrine Ang II peptide and its analog, produced and secreted by the engineered yeast cells, could by themselves promote AGTR1‐mediated signaling. This means that screening for agonistic peptides with various sequences from a self‐produced genetic library would be a viable strategy. Thus, the constructed yeast biosensor, integrating an Asn295‐mutated AGTR1 receptor, will be valuable in the design of drugs to treat AGTR1‐related diseases. Biotechnol. Bioeng. 2014;111: 2220–2228. © 2014 Wiley Periodicals, Inc.
Magnetostrictive particle based biosensors for in situ and real‐time detection of pathogens in water
Authors: Zhang Kewei , Fu Liling , Zhang Lin , Cheng Z.‐Y. , Huang Tung‐Shi 
Published: May 2014

ABSTRACTBiosensors for in situ detection of pathogenic bacteria in liquid are developed using magnetostrictive particles (MSP) as the sensor platform. The sensing elements used are phage E2 against Salmonella typhimurium, monoclonal antibody against Listeria monocytogenes, polyclonal antibody against Escherichia coli, and polyclonal antibody against Staphylococcus aureus, respectively. These biosensors were characterized in cultures with different populations ranging from 5 × 101 to 5 × 108 cfu/mL. It is found that the MSP‐based biosensors work well in water and have a rapid response with a response time in minutes, which makes the MSP‐based sensors suitable for in situ and real‐time detection of pathogenic bacteria in liquid. The experimental results show that all MSP‐phage and MSP‐antibody biosensors in size of 1.0 mm × 0.3 mm × 15 µm exhibit a detection limit better than 100 cfu/mL. Based on the Hill plot, it is concluded that each bacterial cell is bound onto the sensor surface through about four‐to‐five sites. When the cultures with low population (<106 cfu/mL) are tested, both MSP‐phage and MSP‐antibody sensors exhibit the similar response. However, the phage‐MSP sensors exhibit a higher capability in the capture of target bacterial cell. Biotechnol. Bioeng. 2014;111: 2229–2238. © 2014 Wiley Periodicals, Inc.
Specific photosynthetic rate enhancement by cyanobacteria coated onto paper enables engineering of highly reactive cellular biocomposite “leaves”
Authors: Bernal Oscar I. , Mooney Charles B. , Flickinger Michael C. 
Published: May 2014

ABSTRACTWe describe a latex wet coalescence extrusive coating method that produces up to 10‐fold specific photosynthetic rate enhancements by nitrate‐limited non‐growing cyanobacteria deposited onto paper, hydrated and placed in the gas‐phase of small tube photobioreactors. These plant leaf‐like biocomposites were used to study the tolerance of cyanobacteria strains to illumination and temperature using a solar simulator. We report sustained CO2 absorption and O2 production for 500 h by hydrated gas‐phase paper coatings of non‐growing Synechococcus PCC7002, Synechocystis PCC6803, Synechocystis PCC6308, and Anabaena PCC7120. Nitrate‐starved cyanobacteria immobilized on the paper surface by the latex binder did not grow out of the coatings into the bulk liquid. The average CO2 consumption rate in Synechococcus coatings is 5.67 mmol m−2 h−1 which is remarkably close to the rate reported in the literature for Arabidopsis thaliana leaves under similar experimental conditions (18 mmol m−2 h−1). We observed average ratios of oxygen production to carbon dioxide consumption (photosynthetic quotient, PQ) between 1.3 and 1.4, which may indicate a strong dependence on nitrate assimilation during growth and was used to develop a non‐growth media formulation for intrinsic kinetics studies. Photosynthetic intensification factors (PIF) (O2 production by nitrate‐limited cyanobacteria in latex coatings/O2 produced by nitrate‐limited cell suspensions) in cyanobacteria biocomposites prepared from wet cell pellets concentrated 100‐ to 300‐fold show 7–10 times higher specific reactivity compared to cells in suspension under identical nitrate‐limited non‐growth conditions. This is the first report of changes of cyanobacteria tolerance to temperature and light intensities after deposition as a thin coating on a porous matrix, which has important implications for gas‐phase photobioreactor design using porous composite materials. Cryo‐fracture SEM and confocal microscopy images of cell coating distribution on the paper biocomposite suggest that the spatial arrangement of the cells in the coating can affect photoreactivity. This technique could be used to fabricate very stable, multi‐organism composite coatings on flexible microfluidic devices in the gas‐phase capable of harvesting light in a broader range of wavelengths, to optimize thermotolerant, desiccation tolerant, or halotolerant cyanobacteria that produce O2 with secretion of liquid‐fuel precursors synthesized from CO2. Biotechnol. Bioeng. 2014;111: 1993–2008. © 2014 Wiley Periodicals, Inc.