bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct Observations of Biological Carbon Export From Profiling Floats in the Subtropical North Atlantic
Authors: Estapa M. L. , Feen M. L. , Breves E. 
Published: February 2019

AbstractThe complex interplay of biological and physical mechanisms comprising the ocean's biological carbon pump has not been well characterized to date, due to the difficulty of observing these mechanisms in situ at adequate spatial and temporal resolution. An annual time series is presented of direct measurements of export production and particle properties collected using optical sediment trap‐equipped profiling floats cycling every 1.5–2.5 days. The observations indicate strong variability in particle export and bio‐optical properties, influenced by the spring bloom, mesoscale eddy activity, and the mixed layer pump. Temporal and vertical decoupling of fluxes at depths ranging from 150 to 1,000 m was also observed, and remineralization length scales were more variable than predicted by temperature‐ and oxygen‐based models. Net primary production was computed from float observations using a modification of the Carbon‐based Productivity Model and used to estimate export and export (e‐) ratios, which were compared to predictions of literature export models. Mechanistic models explicitly incorporating ecosystem processes and their depth dependence may perform better at reproducing regional observations collected at high temporal resolution.
Field Response of Magnetic Vortices in Dusty Olivine From the Semarkona Chondrite
Authors: Nichols Claire I. O. , Einsle Joshua F. , Im Mi‐Young , Kasama Takeshi , Saghi Zineb , Midgley Paul A. , Harrison Richard J. 
Published: February 2019

AbstractRecent paleomagnetic studies have constrained the strength and longevity of the magnetic field generated by the solar nebula, which has broad implications for the early evolution of the solar system. Paleomagnetic evidence was recorded by nanoscale iron inclusions in olivine crystals in the Semarkona LL 3.0 chondrite. These dusty olivines have been shown to be credible carriers of ancient magnetic remanence. The small scale of the iron inclusions presents several challenges for defining their fundamental magnetic properties. Here we present the first correlative study of the response of these magnetic structures under applied laboratory fields. Results show that the majority of particles are in a single‐vortex state and exhibit stable magnetic behavior in applied fields up to 200 mT. Experimental observations using Lorentz microscopy and magnetic transmission X‐ray microscopy are shown to compare well with the results of finite‐element micromagnetic simulations derived from 3‐D models of the particles obtained using electron tomography. This correlative approach may be used to characterize the fundamental magnetic behavior of many terrestrial and extraterrestrial paleomagnetic carriers in the single‐vortex to multivortex size range, which represent the vast majority of stable magnetic carriers in rocks and meteorites.
Diagnosing Secular Variations in Retrospective ENSO Seasonal Forecast Skill Using CMIP5 Model‐Analogs
Authors: Ding Hui , Newman Matthew , Alexander Michael A. , Wittenberg Andrew T. 
Published: February 2019

AbstractRetrospective tropical Indo‐Pacific forecasts for 1961–2015 are made using 28 models from the fifth phase of the Coupled Model Intercomparison Project (CMIP5) plus four models from the North American Multi‐Model Ensemble (NMME), using a model‐analog technique. Forecast ensembles are extracted from preexisting model simulations, by finding those states that initially best match an observed anomaly and tracking their subsequent evolution, requiring no additional model integrations. Model‐analog forecasts from the 10 “best” CMIP5 models have skill for sea surface temperature and precipitation comparable to that of both the NMME model‐analog forecast ensemble and (since 1982) traditional assimilation‐initialized NMME hindcasts. The El Niño–Southern Oscillation (ENSO) forecast skill has no trend over the 55‐year period, and its decadal variations appear largely random, although the skill does improve during epochs of increased ENSO activity. Including the CMIP5‐projected effects of external radiative forcings improves the tropical sea surface temperature skill of the model‐analog forecasts but not within the ENSO region.
Crater Statistics on the Dark‐Toned, Mafic Floor Unit in Jezero Crater, Mars
Authors: Shahrzad Stephanie , Kinch Kjartan M. , Goudge Timothy A. , Fassett Caleb I. , Needham Debra H. , Quantin‐Nataf Cathy , Knudsen Cecillie P. 
Published: February 2019

AbstractJezero crater is a ~45‐km impact crater on the margin of Isidis basin on Mars. Jezero is the landing site for NASA's Mars 2020 rover mission. The crater hosts a paleolake, and fluvio‐lacustrine deposits formed in this lake remain accessible to exploration. A dark‐toned deposit on the crater floor overlies light‐toned carbonate‐bearing deposits and has been interpreted as a lava flow. We determined the average thickness of this deposit at the margins to be ~13.0 ± 0.8 m. We analyzed the statistics of impact craters superposed on this deposit and estimated its model age as 2.6 ± 0.5 Ga in the Hartmann system, placing it most likely in the Early Amazonian. The error estimate here includes an estimate of the uncertainty associated with the crater counts. Acquisition, caching, and eventual return of a sample from this unit could provide an important calibration point for Mars crater chronology.
Roles of Subducted Pelagic and Terrigenous Sediments in Early Jurassic Mafic Magmatism in NE China: Constraints on the Architecture of Paleo‐Pacific Subduction Zone
Authors: Zhao Liang , Guo Feng , Fan Weiming , Huang Miwei 
Published: February 2019

AbstractThe role of subducted sediments in arc magmatism has been widely documented. However, identifying the sedimentary provenance (e.g., pelagic vs. terrigenous) input in subduction systems is difficult because of the wide compositional range of sedimentary components and the complex magmatic evolution of arcs. Here we report zircon U‐Pb‐Hf‐O isotopes and whole‐rock elemental and Sr‐Nd‐Hf isotopic compositions of four Early Jurassic subduction‐related mafic intrusions from the Yanbian area, NE China. These rocks show typical trace element and isotopic features of arc magmas. In combination with the published data, we discover two distinct elemental‐isotopic arrays of the Early Jurassic mafic rocks across the arc magmatic belt. Such geochemical variations are mainly attributed to variable subducted sediment input into the mantle wedge instead of crustal contamination or assimilation during magmatic evolution. The mantle source for the southern Yanbian mafic rocks was enriched by addition of a crustal component dominated by terrigenous sediments, whereas that for the northern Lesser Hinggan‐Zhangguangcai Range, mafic rocks was modified by another crustal component comprising mainly pelagic sediments. The results can be best interpreted if the southern part was a continental arc as opposed to an oceanic arc in the north, which is analogous to the modern Kamchatka‐Honshu‐Izu‐Bonin‐Mariana arc systems in the western Pacific. Our reconstructed architecture, based mainly on the geochemical data, further suggests that the Khanka‐Jiamusi‐Buleya Massif was probably sinistrally and northwardly displaced to the present position after Mesozoic subduction of the Paleo‐Pacific Ocean.
Differential Incorporation of Bacteria, Organic Matter, and Inorganic Ions Into Lake Ice During Ice Formation
Authors: Santibáñez Pamela A. , Michaud Alexander B. , Vick‐Majors Trista J. , D'Andrilli Juliana , Chiuchiolo Amy , Hand Kevin P. , Priscu John C. 
Published: February 2019

AbstractThe segregation of bacteria, inorganic solutes, and total organic carbon between liquid water and ice during winter ice formation on lakes can significantly influence the concentration and survival of microorganisms in icy systems and their roles in biogeochemical processes. Our study quantifies the distributions of bacteria and solutes between liquid and solid water phases during progressive freezing. We simulated lake ice formation in mesocosm experiments using water from perennially (Antarctica) and seasonally (Alaska and Montana, United States) ice‐covered lakes. We then computed concentration factors and effective segregation coefficients, which are parameters describing the incorporation of bacteria and solutes into ice. Experimental results revealed that, contrary to major ions, bacteria were readily incorporated into ice and did not concentrate in the liquid phase. The organic matter incorporated into the ice was labile, amino acid‐like material, differing from the humic‐like compounds that remained in the liquid phase. Results from a control mesocosm experiment (dead bacterial cells) indicated that viability of bacterial cells did not influence the incorporation of free bacterial cells into ice, but did have a role in the formation and incorporation of bacterial aggregates. Together, these findings demonstrate that bacteria, unlike other solutes, were preferentially incorporated into lake ice during our freezing experiments, a process controlled mainly by the initial solute concentration of the liquid water source, regardless of cell viability.
The Spatial Dependence of Flood Hazard and Risk in the United States
Authors: Quinn Niall , Bates Paul D. , Neal Jeff , Smith Andy , Wing Oliver , Sampson Chris , Smith James , Heffernan Janet 
Published: February 2019

AbstractIn this paper we seek to understand the nature of flood spatial dependence over the conterminous United States. We extend an existing conditional multivariate statistical model to enable its application to this large and heterogenous region and apply it to a 40‐year data set of ~2,400 U.S. Geological Survey gauge series records to simulate 1,000 years of U.S. flooding comprising more than 63,000 individual events with realistic spatial dependence. A continental‐scale hydrodynamic model at 30 m resolution is then used to calculate the economic loss arising from each of these events. From this we are able to compute the probability that different values of U.S. annual total economic loss due to flooding are exceeded (i.e., a loss‐exceedance curve). Comparing these data to an observed flood loss‐exceedance curve for the period 1988–2017 shows a reasonable match for annual losses with probability below 10% (e.g., >1 in 10‐year return period). This analysis suggests that there is a 1% chance of U.S. annual fluvial flood losses exceeding $78Bn in any given year, and a 0.1% chance of them exceeding $136Bn. Analysis of the set of stochastic events and losses yields new insights into the nature of flooding and flood risk in the United States. In particular, we confirm the strong relationship between flood affected area and event peak magnitude, but show considerable variability in this relationship between adjacent U.S. regions. The analysis provides a significant advance over previous national flood risk analyses as it gives the full loss‐exceedance curve instead of simply the average annual loss.
Enhanced superconductivity close to a non-magnetic quantum critical point in electron-doped strontium titanate
Authors: Tomioka Yasuhide , Shirakawa Naoki , Shibuya Keisuke , Inoue Isao H. 
Published: February 2019

AbstractStudies on quantum critical points (QCP) have focused on magnetic QCPs to date. Remarkable phenomena such as superconductivity due to avoided criticality have been discovered, but we focus here on the non-magnetic counterpart, i.e., the superconductivity of SrTiO3 regarded as being close to a ferroelectric QCP. Here we prepare high-quality Sr1−xLaxTi(16O1−z18Oz)3 single crystals without localisation at low temperatures, which allow us to systematically investigate the La substitution of Sr as an alternative to introducing oxygen vacancies. Analysis of our data based on a theoretical model predicts an appearance of the ferroelectric QCP around 3 × 1018 cm−3. Because of the QCP, the superconducting dome of Sr1−xLaxTiO3 can be raised upwards. Furthermore, remarkable enhancement of Tc (~0.6 K) is achieved by 18O exchange on the Sr1−xLaxTiO3 crystals. These findings provide a new knob for observing intriguing physics around the ferroelectric QCP.
Kingdom-wide comparison reveals the evolution of diurnal gene expression in Archaeplastida
Authors: Ferrari Camilla , Proost Sebastian , Janowski Marcin , Becker Jörg , Nikoloski Zoran , Bhattacharya Debashish , Price Dana , Tohge Takayuki , Bar-Even Arren , Fernie Alisdair , Stitt Mark , Mutwil Marek 
Published: February 2019

AbstractPlants have adapted to the diurnal light-dark cycle by establishing elaborate transcriptional programs that coordinate many metabolic, physiological, and developmental responses to the external environment. These transcriptional programs have been studied in only a few species, and their function and conservation across algae and plants is currently unknown. We performed a comparative transcriptome analysis of the diurnal cycle of nine members of Archaeplastida, and we observed that, despite large phylogenetic distances and dramatic differences in morphology and lifestyle, diurnal transcriptional programs of these organisms are similar. Expression of genes related to cell division and the majority of biological pathways depends on the time of day in unicellular algae but we did not observe such patterns at the tissue level in multicellular land plants. Hence, our study provides evidence for the universality of diurnal gene expression and elucidates its evolutionary history among different photosynthetic eukaryotes.
Commercial fishing patterns influence odontocete whale-longline interactions in the Southern Ocean
Authors: Tixier Paul , Burch Paul , Richard Gaetan , Olsson Karin , Welsford Dirk , Lea Mary-Anne , Hindell Mark A. , Guinet Christophe , Janc Anais , Gasco Nicolas , Duhamel Guy , Villanueva Maria Ching , Suberg Lavinia , Arangio Rhys , Söffker Marta , Arnould John P. Y. 
Published: February 2019

AbstractThe emergence of longline fishing around the world has been concomitant with an increase in depredation-interactions by odontocete whales (removal of fish caught on hooks), resulting in substantial socio-economic and ecological impacts. The extent, trends and underlying mechanisms driving these interactions remain poorly known. Using long-term (2003–2017) datasets from seven major Patagonian toothfish (Dissostichus eleginoides) longline fisheries, this study assessed the levels and inter-annual trends of sperm whale (Physeter macrocephalus) and/or killer whale (Orcinus orca) interactions as proportions of fishing time (days) and fishing area (spatial cells). The role of fishing patterns in explaining between-fisheries variations of probabilities of odontocete interactions was investigated. While interaction levels remained globally stable since the early 2000s, they varied greatly between fisheries from 0 to >50% of the fishing days and area. Interaction probabilities were influenced by the seasonal concentration of fishing effort, size of fishing areas, density of vessels, their mobility and the depth at which they operated. The results suggest that between-fisheries variations of interaction probabilities are largely explained by the extent to which vessels provide whales with opportunities for interactions. Determining the natural distribution of whales will, therefore, allow fishers to implement better strategies of spatio-temporal avoidance of depredation.
Enteral Activation of WR-2721 Mediates Radioprotection and Improved Survival from Lethal Fractionated Radiation
Authors: Molkentine Jessica M. , Fujimoto Tara N. , Horvath Thomas D. , Grossberg Aaron J. , Garcia Carolina J. Garcia , Deorukhkar Amit , de la Cruz Bonilla Marimar , Lin Daniel , Samuel Errol L. G. , Chan Wai Kin , Lorenzi Philip L. , Piwnica-Worms Helen , Dantzer Robert , Tour James M. , Mason Kathryn A. , Taniguchi Cullen M. 
Published: February 2019

AbstractUnresectable pancreatic cancer is almost universally lethal because chemotherapy and radiation cannot completely stop the growth of the cancer. The major problem with using radiation to approximate surgery in unresectable disease is that the radiation dose required to ablate pancreatic cancer exceeds the tolerance of the nearby duodenum. WR-2721, also known as amifostine, is a well-known radioprotector, but has significant clinical toxicities when given systemically. WR-2721 is a prodrug and is converted to its active metabolite, WR-1065, by alkaline phosphatases in normal tissues. The small intestine is highly enriched in these activating enzymes, and thus we reasoned that oral administration of WR-2721 just before radiation would result in localized production of the radioprotective WR-1065 in the small intestine, providing protective benefits without the significant systemic side effects. Here, we show that oral WR-2721 is as effective as intraperitoneal WR-2721 in promoting survival of intestinal crypt clonogens after morbid irradiation. Furthermore, oral WR-2721 confers full radioprotection and survival after lethal upper abdominal irradiation of 12.5 Gy × 5 fractions (total of 62.5 Gy, EQD2 = 140.6 Gy). This radioprotection enables ablative radiation therapy in a mouse model of pancreatic cancer and nearly triples the median survival compared to controls. We find that the efficacy of oral WR-2721 stems from its selective accumulation in the intestine, but not in tumors or other normal tissues, as determined by in vivo mass spectrometry analysis. Thus, we demonstrate that oral WR-2721 is a well-tolerated, and quantitatively selective, radioprotector of the intestinal tract that is capable of enabling clinically relevant ablative doses of radiation to the upper abdomen without unacceptable gastrointestinal toxicity.
Induction of GNMT by 1,2,3,4,6-penta-O-galloyl-beta-D-glucopyranoside through proteasome-independent MYC downregulation in hepatocellular carcinoma
Authors: Kant Rajni , Yen Chia-Hung , Hung Jung-Hsien , Lu Chung-Kuang , Tung Chien-Yi , Chang Pei-Ching , Chen Yueh-Hao , Tyan Yu-Chang , Chen Yi-Ming Arthur 
Published: February 2019

AbstractGlycine-N-methyl transferase (GNMT) a tumor suppressor for hepatocellular carcinoma (HCC) plays a crucial role in liver homeostasis. Its expression is downregulated in almost all the tumor tissues of HCC while the mechanism of this downregulation is not yet fully understood. Recently, we identified 1,2,3,4,6-penta-O-galloyl-beta-D-glucopyranoside (PGG) as a GNMT promoter enhancer compound in HCC. In this study, we aimed to delineate the mechanism by which PGG enhances GNMT expression and to investigate its effect on GNMT suppression in HCC. Microarray and pathway enrichment analysis revealed that MYC was a major target of PGG. PGG suppressed MYC mRNA and protein expression in Huh7 and Hep G2 cells in a dose- and time-dependent fashion. Furthermore, MYC expression was also reduced in xenograft tumors in PGG treated mice. Moreover, shRNA-mediated knocked-down or pharmacological inhibition of MYC resulted in a significant induction of GNMT promoter activity and endogenous GNMT mRNA expression in Huh7 cells. In contrast, overexpression of MYC significantly inhibited GNMT promoter activity and endogenous GNMT protein expression. In addition, antibodies against MYC effectively precipitated the human GNMT promoter in a chromatin immunoprecipitation assay. Lastly, GNMT expression was negatively correlated with MYC expression in human HCC samples. Interestingly, PGG not only inhibited MYC gene expression but also promoted MYC protein degradation through proteasome-independent pathways. This work reveals a novel anticancer mechanism of PGG via downregulation of MYC expression and establishes a therapeutic rationale for treatment of MYC overexpressing cancers using PGG. Our data also provide a novel mechanistic understanding of GNMT regulation through MYC in the pathogenesis of HCC.
A widespread internal resonance phenomenon in functionally graded material plates with longitudinal speed
Authors: Zhang Y. F. , Liu J. T. 
Published: February 2019

AbstractA widespread internal resonance phenomenon is detected in axially moving functionally graded material (FGM) rectangular plates. The geometrical nonlinearity is taken into account with the consideration of von Kármán nonlinear geometric equations. Using d’Alembert’s principle, governing equation of the transverse motion is derived. The obtained equation is further discretized to ordinary differential equations using the Galerkin technique. The harmonic balance method is adopted to solve the above equations. Additionally, stability analysis of steady-state solutions is presented. Research shows that a one-to-one internal resonance phenomenon widely exists in a large range of constituent volume distribution in moving FGM plates. Moreover, it is found that this internal resonance phenomenon can easily happen even though the FGM plates are under extremely small external excitation or with very large damping.
Assessment of incidence and various demographic risk factors of traumatic humeral shaft fractures in China
Authors: Ji Chenni , Li Jia , Zhu Yanbin , Liu Song , Fu Lei , Chen Wei , Zhang Yingze 
Published: February 2019

AbstractAs a sub-study of the China National Fracture Study, this study aimed to better determine the incidence and risk factors of humeral shaft fracture in mainland China. We obtained all the data on humeral shaft fracture from the China National Fracture Study reported in 2017. Trained research teams personally interviewed all qualifying household members using a standardised questionnaire. A total of 512,187 (259649 boys and men, 252538 girls and women) questionnaires were collected and analysed from 112 neighbourhood communities and 223 administrative villages using stratified random sampling and the probability proportional to size method. The population-weighted incidence rate of humeral shaft fracture was 7.22 (95% confidence interval 4.90, 9.55) per 100,000 populations in 2014. Previous fracture history was an independent risk factor in adults of both sexes. Smoking was identified as an independent risk factor for humeral shaft fracture for men. Alcohol consumption and menstruation ceasing before the age of 46 years were considered as independent risk factors for women. Given the above data, specific public-health policies focusing on promoting a smoke-free environment and reducing alcohol intake should be encouraged. People who have had a fracture and women whose menstruation had ceased before the age of 46 should be vigilant against humeral shaft fracture.