bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determining Seasonal Emergence and Control Programs for Henbit (Lamium amplexicauleL.)
Authors: Woolam Brandi C. , Stephenson Daniel O. , Blouin David C. 
Published: September 2018

AbstractHenbit is a winter annual weed that is not effectively controlled by spring-applied herbicide applications. Research was conducted to determine henbit’s emergence pattern and whether fall-applied residual herbicides would be effective for henbit control in the spring. Henbit emerges in Louisiana from late October through March, but emergence predominantly occurs in the last week of October through the first week of December. Applying paraquat plus flumioxazin, oxyfluorfen, or rimsulfuron:thifensulfuron November 1 through December 15 provided better than 90% henbit control in March. Applying paraquat plusS-metolachlor on November 15 or December 1 provided 92% henbit control, which was similar to flumioxazin, oxyfluorfen, and rimsulfuron:thifensulfuron. The addition of flumioxazin, oxyfluorfen, or rimsulfuron:thifensulfuron to paraquat reduced the height of henbit plants by 4% to 22% of nontreated plants when applied November 1 through December 15. These studies indicate that crop producers can achieve control of henbit in March following November 1 through December 15 applications of paraquat plus flumioxazin or rimsulfuron:thifensulfuron; however, paraquat plus oxyfluorfen can be applied October 15 through December 15 to achieve similar control.
Ionospheric Scintillation Observation Using Space‐Borne Synthetic Aperture Radar Data
Authors: Mohanty S. , Singh G. , Carrano C. S. , Sripathi S. 
Published: September 2018

AbstractNetworks of ground‐based global navigation satellite system (GNSS) receivers have been widely used to monitor scintillation caused by irregularities in the disturbed ionosphere. Due to the relative sparseness of such networks, however, scintillation measurements are lacking in many regions of the globe, and even in well‐instrumented geographic areas, the spacing between receivers is often too large to study the systematic spatial changes in scintillation characteristics, for example, across the equatorial anomaly region. This paper discusses the potential of studying ionospheric scintillations using low‐frequency synthetic aperture radar (SAR). It compares standard metrics of scintillation including the amplitude scintillation index S4 and vertically integrated strength of turbulence CkL, from GNSS and SAR, on two different dates with varying ionospheric conditions. For this study, polarimetric L‐band SAR images acquired from the Phased Array‐type L‐band Synthetic Aperture Radar sensor onboard the Advanced Land Observational Satellite‐2 have been used. A number of GNSS satellites also observed the particular scintillation event that was encountered by SAR on the night of 23 March 2015 over the southern and mid‐central India. The S4 index derived from SAR are computed using previously published techniques in terms of radar backscatter (σ°) enhancement and the image contrast. The results show a favorable correlation with the GNSS observations. Along with accurate information about satellite geometry and operating frequency, few spectral properties of ionospheric irregularities, such as spectral index, anisotropy, and outer scale, have been assumed from historically available low‐latitude scintillation observations to calculate the turbulence strength parameter. The results are well corroborated by measurements from four GNSS stations in India, thus demonstrating the utility of the SAR measurements in augmenting and complementing the ionospheric scintillation diagnostics available from GNSS.
A New Enceladus Global Control Network, Image Mosaic, and Updated Pointing Kernels From Cassini's 13‐Year Mission
Authors: Bland M. T. , Becker T. L. , Edmundson K. L. , Roatsch Th. , Archinal B. A. , Takir D. , Patterson G. W. , Collins G. C. , Schenk P. M. , Pappalardo R. T. , Cook D. A. 
Published: September 2018

AbstractNASA's Cassini spacecraft spent 13 years exploring the Saturn system, including 23 targeted flybys of the small, geologically active moon Enceladus. These flybys provided a wealth of image data from Cassini's Imaging Science Subsystem. To improve the usability of the Enceladus data set, we created a new, global photogrammetric control network for Enceladus that enabled compilation of a versatile cartographic package to support geologic mapping and other investigations. The network used 586 images in four image filters with a pixel scale generally between 50 and 500 m per pixel and a phase angle less than 120° and consisted of 10,362 tie points and 173,704 individual image measures, averaging nearly 17 measures per tie point. Least squares bundle adjustment resulted in a root‐mean‐square residual of 0.45 pixel, corresponding to root‐mean‐square ground point uncertainties of 66, 51, and 46 m in latitude, longitude, and radius, respectively. Using our geodetic control network, we created new global image mosaics, coregistered flyby mosaics to support geologic mapping, and updated pointing kernels for every image used in the solution. These products, including the updated pointing kernels, are available to the community through NASA's Planetary Data System Imaging Annex. The bundle adjustment solution also yielded independently determined shape information, resulting in radii within the stated uncertainty of International Astronomical Union values. The challenges of the data set, and the technical methodology described here are applicable to bodies imaged during multiple flybys with variable viewing and illumination geometry, including other midsized satellites of Saturn, and the Europa Clipper mission.
Subsurface Fluid Pressure and Rock Deformation Monitoring Using Seismic Velocity Observations
Authors: Doetsch Joseph , Gischig Valentin S. , Villiger Linus , Krietsch Hannes , Nejati Morteza , Amann Florian , Jalali Mohammadreza , Madonna Claudio , Maurer Hansruedi , Wiemer Stefan , Driesner Thomas , Giardini Domenico 
Published: September 2018

AbstractFluid pressure within the Earth's crust is a key driver for triggering natural and human‐induced seismicity. Measuring fluid pressure evolution would be highly beneficial for understanding the underlying driving mechanisms and supporting seismic hazard assessment. Here we show that seismic velocities monitored on the 20‐m scale respond directly to changes in fluid pressure. Our data show that volumetric strain resulting from effective stress changes is sensed by seismic velocity, while shear dislocation is not. We are able to calibrate seismic velocity evolution against fluid pressure and strain with in situ measurements during a decameter‐scale fluid injection experiment in crystalline rock. Thus, our 4‐D seismic tomograms enable tracking of fluid pressure and strain evolution. Our findings demonstrate a strong potential toward monitoring transient fluid pressure variations and stress changes for well‐instrumented field sites and could be extended to monitoring hydraulic stimulations in deep reservoirs.
Large Midlatitude Stratospheric Temperature Variability Caused by Inertial Instability: A Potential Source of Bias for Gravity Wave Climatologies
Authors: Rapp M. , Dörnbrack A. , Preusse P. 
Published: September 2018

AbstractStratospheric temperature perturbations (TP) that have previously been misinterpreted as due to gravity waves are revisited. The perturbations observed by radio occultations during December 2015 had peak‐to‐peak amplitudes of 10 K extending from the equator to midlatitudes. The vertically stacked and horizontally flat structures had a vertical wavelength of 12 km. The signs of the TP were 180∘ phase shifted between equatorial and midlatitudes at fixed altitude levels. High‐resolution operational analyses reveal that these shallow temperature structures were caused by inertial instability due to the large meridional shear of the polar night jet at its equatorward flank in combination with Rossby wave breaking. Large stratospheric TP owing to inertial instability do frequently occur in the Northern Hemisphere (Southern Hemisphere) from October to April (April to October) in the 39 years of ECMWF Re‐Analysis‐Interim data. During 10% of the days, TP exceed 5 K (peak to peak).
A Turbulence‐Based Bed‐Load Transport Model for Bare and Vegetated Channels
Authors: Yang J. Q. , Nepf H. M. 
Published: September 2018

AbstractPrevious studies have shown that sediment transport models based on bed shear stress (τ) are not accurate for regions with vegetation. The present study demonstrated that the inaccuracy arises from the influence of vegetation‐generated turbulence. Bed‐load transport rate, Qs, and near‐bed velocity were measured in a sediment‐recirculating flume with model vegetation of different vegetation volume fractions (ϕ) and with bare sand beds. At the same τ, the measured Qs increased with increasing ϕ, suggesting that vegetation‐generated turbulence, which also increased with increasing ϕ, was augmenting the bed‐load transport. At the same near‐bed turbulent kinetic energy, kt, the Qs measured in both bare and vegetated channels agreed within uncertainty, suggesting that kt may be a more universal predictor of bed‐load transport than bed shear stress. A τ‐based bed‐load transport model was reinterpreted as a kt‐based model. The new kt‐based model predicted the Qs measurements for both bare and vegetated channels.
Net Community Production in the Southern Ocean: Insights From Comparing Atmospheric Potential Oxygen to Satellite Ocean Color Algorithms and Ocean Models
Authors: Nevison Cynthia , Munro David , Lovenduski Nicole , Cassar Nicolas , Keeling Ralph , Krummel Paul , Tjiputra Jerry 
Published: September 2018

AbstractThe contribution of oceanic net community production (NCP) to the observed seasonal cycle in atmospheric potential oxygen (APO) is estimated at Cape Grim, Tasmania. The resulting APONCP signal is compared to satellite and ocean model‐based estimates of POC export and NCP across the Southern Ocean. The satellite products underestimate the amplitude of the observed APONCP seasonal cycle by more than a factor of 2. Ocean models suggest two reasons for this underestimate: (1) Current satellite products substantially underestimate the magnitude of NCP in early spring. (2) Seasonal O2 outgassing is supported in large part by storage of carbon in DOC and living biomass. More DOC observations are needed to help evaluate this latter model prediction. Satellite products could be improved by developing seasonally dependent relationships between remote sensing chlorophyll data and in situ NCP, recognizing that the former is a measure of mass, the latter of flux.
Abundance and Emission Flux of the Anthropogenic Iron Oxide Aerosols From the East Asian Continental Outflow
Authors: Yoshida Atsushi , Ohata Sho , Moteki Nobuhiro , Adachi Kouji , Mori Tatsuhiro , Koike Makoto , Takami Akinori 
Published: September 2018

AbstractAnthropogenic iron oxide (FeOx) aerosols can affect atmospheric radiation, marine biogeochemistry, and human health. However, due to lack of observational data, their atmospheric abundance and emission flux are not well understood. In this study, we observed size‐resolved concentrations of FeOx (170–2100 nm) and black carbon (BC, 70–850 nm) aerosols at a remote site in the East China Sea in March 2016 using a modified single‐particle soot photometer (SP2). Light signals measured by the SP2 and particle morphology and compositions analyzed by a transmission electron microscope revealed that most of the observed FeOx aerosols are of anthropogenic origin. Clear correlations were found between mass concentrations of FeOx and BC (R2 = 0.717) and between FeOx and carbon monoxide (CO) (R2 = 0.718) in air masses from China, indicating that their emission sources are spatially similar. The correlation slopes of mass concentration (ng/m3) are ~0.3 and 0.0015, respectively. Based on the correlation slopes and emission inventories of BC and CO in China, we estimated emission flux of anthropogenic FeOx aerosols from China to be 0.21–0.49 FeTg/yr. Based on the observed size distribution and previous studies on mass fraction of FeOx and non‐FeOx, we also estimated emission flux of anthropogenic Fe (FeOx + non‐FeOx) in PM10 as 0.74–1.7 FeTg/yr. These emission fluxes from China are comparable to global emission fluxes in currently reported inventories of anthropogenic Fe (0.51–1.91 FeTg/yr). Our results suggest that the current emission inventories of anthropogenic Fe are underestimated.
Cold Tropical Pacific Sea Surface Temperatures During the Late Sixteenth‐Century North American Megadrought
Authors: Cook Benjamin I. , Williams A. Park , Smerdon Jason E. , Palmer Jonathan G. , Cook Edward R. , Stahle David W. , Coats Sloan 
Published: September 2018

AbstractThe late 16th‐century North American megadrought was notable for its persistence, extent, intensity, and occurrence after the main interval of megadrought activity during the Medieval Climate Anomaly. Forcing from sea surface temperatures (SSTs) in the tropical Pacific is considered a possible driver of megadroughts, and we investigate this hypothesis for the late 16th‐century event using two new 600‐year long hydroclimate field reconstructions from Mexico and Australia. Areas represented by these reconstructions have strong teleconnections to tropical Pacific SSTs, evidenced by the leading principal component in each region explaining ∼40% of local hydroclimate variability and correlating significantly with the boreal winter (December‐January‐February) NINO 3.4 index. Using these two principal components as predictors, we develop a skillful reconstruction of the December‐January‐February NINO 3.4 index. The reconstruction reveals that the late 16th‐century megadrought likely occurred during one of the most persistent and intense periods of cold tropical Pacific SST anomalies of the last 600 years (1566–1590 C.E.; median NINO 3.4 = −0.79 K). This anomalously cold period coincided with a major filling episode for Kati Thanda‐Lake Eyre in Australia, a hydroclimate response dynamically consistent with the reconstructed SST state. These results offer new evidence that tropical Pacific forcing was an important driver of the late 16th‐century North American megadrought over the Southwest and Mexico, highlighting the large amplitude of natural variability that can occur within the climate system.
The Influence of Spatial Variability of Width Functions on Regional Peak Flow Regressions
Authors: Perez Gabriel , Mantilla Ricardo , Krajewski Witold F. 
Published: September 2018

AbstractThe authors investigated the relation between the width function and the regional variability of peak flows. The authors explored 34 width function descriptors (WFDs), in addition to drainage area, as potential candidates for explaining the regional peak flow variability. First, using hydrologic simulations of uniform rainfall events with variable rainfall duration and constant rainfall intensity for 147 watersheds across the state of Iowa, they demonstrated that WFDs are capable of explaining spatial variability of peak flows for individual rainfall‐runoff events under idealized physical conditions. This theoretical exercise indicates that the inclusion of WFDs should drastically improve regional peak flow estimates with a reduction of the root mean square error by more than half in comparison with a regression model based on drainage area only. The authors followed the simulation with an analysis of estimated peak flow quantiles from 94 stream gauges in Iowa to determine if the WFDs have a similar explanatory power. The correlations between WFDs and peak flow quantiles are not as high as those found for simulated events, which indicates that results from event scale simulations do not translate directly to peak flow quantiles. The spatial variability of peak flow quantiles is influenced by other physical and statistical processes that are also variable in space. These results are consistent with recent work on event‐based scaling of peak flows that shows that the spatiotemporal variability of flood mechanisms is larger than the one expected from geomorphology alone.
Endothelial cell activation on 3D-matrices derived from PDGF-BB-stimulated fibroblasts is mediated by Snail1
Authors: Herrera Alberto , Herrera Mercedes , Guerra-Perez Natalia , Galindo-Pumariño Cristina , Larriba María Jesús , García-Barberán Vanesa , Gil Beatriz , Giménez-Moyano Sara , Ferreiro-Monteagudo Reyes , Veguillas Pilar , Candia Antonio , Peña Raúl , Pinto Jesús , García-Bermejo Mª Laura , Muñoz Alberto , García de Herreros Antonio , Bonilla Félix , Carrato Alfredo , Peña Cristina 
Published: September 2018

AbstractCarcinomas, such as colon cancer, initiate their invasion by rescuing the innate plasticity of both epithelial cells and stromal cells. Although Snail is a transcriptional factor involved in the Epithelial-Mesenchymal Transition, in recent years, many studies have also identified the major role of Snail in the activation of Cancer-Associated Fibroblast (CAF) cells and the remodeling of the extracellular matrix. In CAFs, Platelet-derived growth factor (PDGF) receptor signaling is a major functional determinant. High expression of both SNAI1 and PDGF receptors is associated with poor prognosis in cancer patients, but the mechanism(s) that underlie these connections are not understood. In this study, we demonstrate that PDGF-activated fibroblasts stimulate extracellular matrix (ECM) fiber remodeling and deposition. Furthermore, we describe how SNAI1, through the FAK pathway, is a necessary factor for ECM fiber organization. The parallel-oriented fibers are used by endothelial cells as “tracks”, facilitating their activation and the creation of tubular structures mimicking in vivo capillary formation. Accordingly, Snail1 expression in fibroblasts was required for the co-adjuvant effect of these cells on matrix remodeling and neoangiogenesis when co-xenografted in nude mice. Finally, in tumor samples from colorectal cancer patients a direct association between stromal SNAI1 expression and the endothelial marker CD34 was observed. In summary, our results advance the understanding of PDGF/SNAI1-activated CAFs in matrix remodeling and angiogenesis stimulation.
Long non-coding RNA CCAL/miR-149/FOXM1 axis promotes metastasis in gastric cancer
Authors: Luo Xi , Wang Gui-Hua , Bian Zhao-Lian , Li Xi-Wen , Zhu Bing-Ying , Jin Chun-Jing , Ju Shao-Qing 
Published: September 2018

AbstractEarly evidence indicates that the long non-coding RNA CCAL plays a critical role in cancer progression and metastasis. However, the overall biological role and clinical significance of CCAL in gastric tumourigenesis and progression remain largely unknown. We observed that CCAL was upregulated in gastric cancer tissues and was associated with the tumour-node-metastasis stage. Functional experiments showed that CCAL promoted gastric cancer cell proliferation and metastasis in vitro and in vivo. Luciferase reporter assay indicated that CCAL directly bind to miR-149. Moreover, knockdown of CCAL significantly reduced the expression of FOXM1, a direct target of miR-149. We also showed that FOXM1 suppression by miR-149 could be partially rescued by CCAL overexpression. In addition, we identified a negative correlation between the mRNA expression of CCAL and miR-149 in gastric cancer tissues. Furthermore, we observed a negative correlation between the expression of miR-149 and FOXM1 and a positive correlation between CCAL and FOXM1 levels. These results demonstrated that the CCAL/miR-149/FOXM1 axis functions as a key regulator in gastric cancer metastasis and CCAL potentially represents a biomarker for diagnosis and potential target for therapy in the future.
E4BP4 promotes thyroid cancer proliferation by modulating iron homeostasis through repression of hepcidin
Authors: Zhou Qinyi , Chen Jun , Feng Jialin , Wang Jiadong 
Published: September 2018

AbstractIron homeostasis is critical to mammals, and dysregulation in iron homeostasis usually leads to severe disorders including various cancers. Massive hepcidin secretion is an indicator of thyroid cancer, but the molecular mechanisms responsible for this dysregulation are unknown. Hepcidin secretion from thyroid cancer cells also leads to decreased expression of the iron exporter, ferroportin (FPN), and increased intracellular iron retention, which promote cancer proliferation. In this study, we examined the role of hepcidin in thyroid cancer (TC) and the molecular bases of its signaling. Synthesis of hepcidin is regulated by the BMP4/7 agonist SOSTDC1, which was downregulated in TC; SOSTDC1 downregulation was correlated with G9a-mediated hypermethylation in its promoter. The binding of G9a to the SOSTDC1 promoter requires E4BP4, which interacts with G9a to form a multi-molecular complex that contributes to SOSTDC1 silencing. Silencing of E4BP4 or G9a has similar effects to SOSTDC1 overexpression, which suppresses secretion of hepcidin and inhibits TC cell proliferation. Furthermore, our in vivo xenograft data indicated that depletion of E4BP4 also inhibits cancer growth, reduces hepcidin secretion, and reduces G9a nuclear transportation. Iron homeostasis and tumor growth in TC may be regulated by an E4BP4-dependent epigenetic mechanism. These findings suggest a new mechanism of cellular iron dysfunction through the E4BP4/G9a/SOSTDC1/hepcidin pathway, which is an essential link in TC.
Sensitizing non-small cell lung cancer to BCL-xL-targeted apoptosis
Authors: Shen Qi , Li Jun , Mai Junhua , Zhang Zhe , Fisher Andrew , Wu Xiaoyan , Li Zhaoqi , Ramirez Maricela R. , Chen Shuqing , Shen Haifa 
Published: September 2018

AbstractLung cancer is the leading cause of death in the United States, with non-small cell lung cancers (NSCLC) accounting for 85% of all cases. By analyzing the expression profile of the pro-apoptotic and anti-apoptotic proteins, we have assigned NSCLCs into two distinct groups. While single agent treatment with the BCL-2/BCL-xL/BCL-w inhibitor ABT-263 (navitoclax) did not trigger apoptosis in either group, cells with a moderate to high level of MCL-1 expression were sensitive to ABT-263 treatment when MCL-1 expression was suppressed with a gene-specific siRNA. In contrast, those with a low MCL-1 expression did not undergo apoptosis upon combination treatment with ABT-263 and MCL-1 siRNA. Further studies revealed that cells with a low MCL-1 expression had low mitochondrial priming, and treatment with the chemotherapy drug docetaxel raised the mitochondrial priming level and consequently sensitized cells to ABT-263. These results establish a rationale for molecular profiling and a therapeutic strategy to treat NSCLC patients with pro-apoptotic anti-cancer drugs based on their MCL-1 expression level.