bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abiotic control of underwater light in a drinking water reservoir: Photon budget analysis and implications for water quality monitoring
Authors: Watanabe Shohei , Laurion Isabelle , Markager Stiig , Vincent Warwick F. 
Published: July 2015

AbstractIn optically complex inland waters, the underwater attenuation of photosynthetically active radiation (PAR) is controlled by a variable combination of absorption and scattering components of the lake or river water. Here we applied a photon budget approach to identify the main optical components affecting PAR attenuation in Lake St. Charles, a drinking water reservoir for Québec City, Canada. This analysis showed the dominant role of colored dissolved organic matter (CDOM) absorption (average of 44% of total absorption during the sampling period), but with large changes over depth in the absolute and relative contribution of the individual absorption components (water, nonalgal particulates, phytoplankton and CDOM) to PAR attenuation. This pronounced vertical variation occurred because of the large spectral changes in the light field with depth, and it strongly affected the average in situ diffuse absorption coefficients in the water column. For example, the diffuse absorption coefficient for pure‐water in the ambient light field was 10‐fold higher than the value previously measured in the blue open ocean and erroneously applied to lakes and coastal waters. Photon absorption budget calculations for a range of limnological conditions confirmed that phytoplankton had little direct influence on underwater light, even at chlorophyll a values above those observed during harmful algal blooms in the lake. These results imply that traditional measures of water quality such as Secchi depth and radiometric transparency do not provide a meaningful estimate of the biological state of the water column in CDOM‐colored lakes and reservoirs.
Ionospheric disturbances in the vicinity of the Chelyabinsk meteoroid explosive disruption as inferred from dense GPS observations
Authors: Perevalova N. P. , Shestakov N. V. , Voeykov S. V. , Takahashi H. , Guojie M. 
Published: July 2015

AbstractThe paper describes results of studying effects of total electron content (TEC) variations triggered by the Chelyabinsk meteoroid airburst as inferred from unique data of a dense GPS network located around the final part of the meteoroid atmospheric path. Well‐pronounced TEC disturbances with an average period of about 10 min and amplitude of 0.07–0.5 TECU (total electron content unit, 1 TECU = 1016 el m−2) were detected. These disturbances were initiated by an ionospheric source activated about 5–6 min after the airburst. The disturbance velocity damping with time and distance from the airburst was revealed using a GPS interferometric technique. Several modes of TEC disturbances with propagation velocities ranging from 250 to 660 m/s were distinguished through the distance‐time diagram analysis. The estimated position of ionospheric source of TEC disturbances is shifted 36 km southwestward from the airburst, which is most likely to be associated with the conjoint influence of TEC data errors, damping and anisotropy of TID propagation velocity.
Numerical simulation of an elve modulated by a gravity wave
Authors: Marshall R. A. , Yue Jia , Lyons Walter A. 
Published: July 2015

AbstractRecent video observations have shown that elves—the visible manifestation of the lightning electromagnetic pulse (EMP) interacting with the lower ionosphere—can be modulated by neutral density fluctuations at lower ionosphere altitudes due to gravity waves. The elve emissions thus illuminate the gravity wave structure. Here we use a finite difference time domain (FDTD) model of the lightning EMP to simulate elve emissions in the presence of neutral density fluctuations representative of gravity waves. We show that observable elve striations can be generated by gravity waves with a neutral density perturbation of as low as 5% at elve altitudes near 85 km. Higher perturbations lead to more pronounced striations. The depth of the optical signature perturbation is found to be similar in magnitude to the neutral density perturbation at elve altitudes, although the relationship depends on viewing geometry, gravity wave geometry, and the elve‐causative lightning peak current moment.
Stratospheric intrusions, the Santa Ana winds, and wildland fires in Southern California
Authors: Langford A. O. , Pierce R. B. , Schultz P. J. 
Published: July 2015

AbstractThe Santa Ana winds of Southern California have long been associated with wildland fires that can adversely affect air quality and lead to loss of life and property. These katabatic winds are driven primarily by thermal gradients but can be exacerbated by northerly flow associated with upper level troughs passing through the western U.S. In this paper, we show that the fire danger associated with the passage of upper level troughs can be further increased by the formation of deep tropopause folds that transport extremely dry ozone‐rich air from the upper troposphere and lower stratosphere to the surface. Stratospheric intrusions can thus increase surface ozone both directly through transport and indirectly through their influence on wildland fires. We illustrate this situation with the example of the Springs Fire, which burned nearly 25,000 acres in Ventura County during May 2013.
Improved outer boundary conditions for outer radiation belt data assimilation using THEMIS‐SST data and the Salammbo‐EnKF code
Authors: Maget V. , Sicard‐Piet A. , Bourdarie S. , Lazaro D. , Turner D. L. , Daglis I. A. , Sandberg I. 
Published: July 2015

AbstractOver the last decade, efforts have been made in the radiation belt community to develop data assimilation tools in order to improve the accuracy of radiation belts models. In this paper we present a new method to correctly take into account the outer boundary conditions at L* = 8 in such an enhanced model of the radiation belts. To do that we based our work on the Time History of Events and Macroscale Interactions during Substorms/Solid State Telescope data set. Statistics are developed to define a consistent electron distribution at L* = 8 (in both equatorial pitch angle and energy), and a variance‐covariance matrix is estimated in order to more realistically drive the Monte Carlo sampling required by the Ensemble Kalman Filter (EnKF). Data processing is first described as well as caveats avoided, and then the use of these information in a machinery such as the EnKF is described. It is shown that the way the Monte Carlo simulations are performed is of great importance to realistically reproduced outer boundary distribution needed by the physic‐based Salammbô model. Finally, EnKF simulations are performed and compared during September 2011 in order to analyze the improvements gained using this new method of defining outer boundary conditions. In particular, we highlight in this study that such a method provides great improvement in the reconstruction of the dynamics observed at geosynchronous orbit, both during quiet and active magnetic conditions.
A numerical study of the effects of migrating tides on thermosphere midnight density maximum
Authors: Ruan Haibing , Du Jian , Cook Matt , Wang Wenbin , Yue Jia , Gan Quan , Dou Xiankang , Lei Jiuhou 
Published: July 2015

AbstractIn this study, we employed the National Center for Atmospheric Research Thermosphere Ionosphere Electrodynamics General Circulation Model (TIEGCM) and the extended Canadian Middle Atmosphere Model (eCMAM) to investigate the role of the migrating terdiurnal tide on the formation and variation of the thermosphere midnight temperature maximum (MTM) and midnight mass density maximum (MDM). The migrating terdiurnal tide from the eCMAM was applied at the TIEGCM's lower boundary, along with the migrating diurnal and semidiurnal tides from the Global‐Scale Wave Model. Several numerical experiments with different combinations of tidal forcing at the TIEGCM's lower boundary were carried out to determine the contribution of each tide to MTM/MDM. We found that the interplay between diurnal, semidiurnal, and terdiurnal tides determines the formation of MTM/MDM and their structure in the upper thermosphere. The decrease of thermospheric mass density after MDM reaches its maximum at ~02:00 local time is mainly controlled by the terdiurnal tide. Furthermore, we examined the generation mechanisms of the migrating terdiurnal tide in the upper thermosphere and found that they come from three sources: upward propagation from the lower thermosphere, in situ generation via nonlinear interaction, and thermal excitation.
The Dst index underestimates the solar cycle variation of geomagnetic activity
Authors: Temerin Michael , Li Xinlin 
Published: July 2015

AbstractIt is known that the correction of the Kyoto Dst index for the secular variation of the Earth's internal field produces a discontinuity in the Kyoto Dst index at the end of each year. We show that this secular correction also introduces a significant baseline error to the Kyoto Dst index that leads to an underestimate of the solar cycle variation of geomagnetic activity and of the strength of the ring current as measured by the Kyoto Dst index. Thus, the average value of the Kyoto Dst index would be approximately 13 nT more negative for the active year 2003 compared to quiet years 2006 and 2009 if the Kyoto Dst index properly measured the effects of the ring current and other currents that influence the Dst observatories. Discontinuities in the Kyoto Dst index at the end of each year have an average value of about 5 nT, but the discontinuity at the end of year 2002 was approximately 12 nT, and the discontinuity at the end of year 1982 may have been as large as 20 nT.
Ammonia and methane dairy emission plumes in the San Joaquin Valley of California from individual feedlot to regional scales
Authors: Miller David J. , Sun Kang , Tao Lei , Pan Da , Zondlo Mark A. , Nowak John B. , Liu Zhen , Diskin Glenn , Sachse Glen , Beyersdorf Andreas , Ferrare Richard , Scarino Amy Jo 
Published: July 2015

AbstractAgricultural ammonia (NH3) emissions are highly uncertain, with high spatiotemporal variability and a lack of widespread in situ measurements. Regional NH3 emission estimates using mass balance or emission ratio approaches are uncertain due to variable NH3 sources and sinks as well as unknown plume correlations with other dairy source tracers. We characterize the spatial distributions of NH3 and methane (CH4) dairy plumes using in situ surface and airborne measurements in the Tulare dairy feedlot region of the San Joaquin Valley, California, during the NASA Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality 2013 field campaign. Surface NH3 and CH4 mixing ratios exhibit large variability with maxima localized downwind of individual dairy feedlots. The geometric mean NH3:CH4 enhancement ratio derived from surface measurements is 0.15 ± 0.03 ppmv ppmv−1. Individual dairy feedlots with spatially distinct NH3 and CH4 source pathways led to statistically significant correlations between NH3 and CH4 in 68% of the 69 downwind plumes sampled. At longer sampling distances, the NH3:CH4 enhancement ratio decreases 20–30%, suggesting the potential for NH3 deposition as a loss term for plumes within a few kilometers downwind of feedlots. Aircraft boundary layer transect measurements directly above surface mobile measurements in the dairy region show comparable gradients and geometric mean enhancement ratios within measurement uncertainties, even when including NH3 partitioning to submicron particles. Individual NH3 and CH4 plumes sampled at close proximity where losses are minimal are not necessarily correlated due to lack of mixing and distinct source pathways. Our analyses have important implications for constraining NH3 sink and plume variability influences on regional NH3 emission estimates and for improving NH3 emission inventory spatial allocations.
The microphysical pathway to contrail formation
Authors: Kärcher B. , Burkhardt U. , Bier A. , Bock L. , Ford I. J. 
Published: July 2015

AbstractA conceptual framework to predict microphysical and optical properties of contrail particles within a wingspan behind the source aircraft is developed. Results from two decades of contrail observations and numerical simulations are reviewed forming the basis of theoretical model development. The model utilizes cloud theory applied to the dynamics and thermodynamics of jet aircraft exhaust plumes in upper tropospheric conditions. Droplet nuclei include soot particles emitted from aircraft engines and atmospheric particles entrained into the plume. These precursor particles activate into copious homogeneously freezing water droplets as the plume relative humidity rises beyond liquid water saturation. A unimodal size spectrum of ice particles develops wherein ice particles grow to micrometer mean sizes. Contrail particle formation is analyzed over a wide range of soot emissions relating to conventional jet fuels as well as to alternative aviation fuels producing much less soot and volatile particle emissions. For current aviation fuels and propulsion technology, the number of contrail ice particles scales roughly in proportion to the number of emitted soot particles that act as water condensation nuclei despite their poor hygroscopicity. Close to the contrail formation threshold, only few plume particles can be water activated and freeze. Implications for effects of alternative fuels on contrails, an arena for future scientific exploration, are outlined.
Accounting for aerosol scattering in the CLARS retrieval of column averaged CO2 mixing ratios
Authors: Zhang Qiong , Natraj Vijay , Li King‐Fai , Shia Run‐Lie , Fu Dejian , Pongetti Thomas J. , Sander Stanley P. , Roehl Coleen M. , Yung Yuk L. 
Published: July 2015

AbstractThe California Laboratory for Atmospheric Remote Sensing Fourier transform spectrometer (CLARS‐FTS) deployed at Mount Wilson, California, has been measuring column abundances of greenhouse gases in the Los Angeles (LA) basin in the near‐infrared spectral region since August 2011. CLARS‐FTS measures reflected sunlight and has high sensitivity to absorption and scattering in the boundary layer. In this study, we estimate the retrieval biases caused by aerosol scattering and present a fast and accurate approach to correct for the bias in the CLARS column averaged CO2 mixing ratio product, XCO2. The high spectral resolution of 0.06 cm−1 is exploited to reveal the physical mechanism for the bias. We employ a numerical radiative transfer model to simulate the impact of neglecting aerosol scattering on the CO2 and O2 slant column densities operationally retrieved from CLARS‐FTS measurements. These simulations show that the CLARS‐FTS operational retrieval algorithm likely underestimates CO2 and O2 abundances over the LA basin in scenes with moderate aerosol loading. The bias in the CO2 and O2 abundances due to neglecting aerosol scattering cannot be canceled by ratioing each other in the derivation of the operational product of XCO2. We propose a new method for approximately correcting the aerosol‐induced bias. Results for CLARS XCO2 are compared to direct‐Sun XCO2 retrievals from a nearby Total Carbon Column Observing Network (TCCON) station. The bias‐correction approach significantly improves the correlation between the XCO2 retrieved from CLARS and TCCON, demonstrating that this approach can increase the yield of useful data from CLARS‐FTS in the presence of moderate aerosol loading.
Fast accessing Web3D contents using lightweight progressive meshes
Authors: Wen Laixiang , Xie Ning , Jia Jinyuan 
Published: July 2015

AbstractAccessing Web3D contents is relatively slow through Internet under limited bandwidth. Preprocessing of 3D models can certainly alleviate the problem, such as 3D compression and progressive meshes (PM). But none of them considers the similarity between components of a 3D model, so that we could take advantage of this to further improve the efficiency. This paper proposes a similarity‐aware data reduction method together with PM, called lightweight progressive meshes (LPM). LPM aims to excavate similar components in a 3D model, generates PM representation of each component left after removing redundant components, and organizes all the processed data using a structure called lightweight scene graph. The proposed LPM possesses four significant advantages. First, it can minimize the file size of 3D model dramatically without almost any precision loss. Because of this, minimal data is delivered. Second, PM enables the delivery to be progressive, so called streaming. Third, when rendering at client side, due to lightweight scene graph, decompression is not necessary and instanced rendering is fully exerted. Fourth, it is extremely efficient and effective under very limited bandwidth, especially when delivering large 3D scenes. Performance on real data justifies the effectiveness of our LPM, which improves the state‐of‐the‐art in accessing Web3D contents. Copyright © 2015 John Wiley & Sons, Ltd.
Gab1 amplifies signaling in response to low‐intensity stimulation by HGF
Authors: Aasrum Monica , Ødegård John , Thoresen Gunn Hege , Brusevold Ingvild J. , Sandnes Dagny L. , Christoffersen Thoralf 
Published: July 2015

AbstractThe receptor tyrosine kinases EGFR and Met induce phosphorylation of the docking protein Gab1, and there is evidence that Gab1 may have a role in the signaling from these receptors. Studying hepatocytes, we previously found that although Gab1 mechanistically interacted in different ways with EGFR and Met, it was involved in mitogenic signaling induced by both EGF and HGF. It has been reported that in EGFR, Gab1 is required particularly at a low dose of EGF. Whether this also applies to HGF/Met signaling has not been investigated. We have studied the role of Gab1 in activation of the Akt and ERK pathways at low‐ and high‐intensity stimulation with EGF and HGF in cultured hepatocytes. In cells where Gab1 was depleted by a specific Gab1‐directed siRNA, the EGF‐induced phosphorylation of ERK was lowered and HGF‐induced phosphorylation of both ERK and Akt was substantially reduced. These effects were more marked at low‐dose HGF stimulation. The inhibitory consequence of Gab1 depletion was particularly pronounced for HGF‐induced Akt phosphorylation. The results suggest that Gab1 is an important signal amplifier for low‐intensity stimulation by HGF.
Acute polyhydramnios after maternal status epilepticus
Authors: Shindo Ryosuke , Aoki Shigeru , Kasai Michi , Takahashi Tsuneo , Hirahara Fumiki 
Published: July 2015

Key Clinical MessageMaternal status epilepticus can cause fetal hypoxic ischemic encephalopathy that in turn results in acute polyhydramnios caused by fetal dysphagia; thus, acute polyhydramnios is a symptom that should lead to a suspicion of fetal dysphagia caused by hypoxic ischemic encephalopathy.
Polymyositis and fatal interstitial pneumonia following pelvic irradiation that led to unexpectedly severe adverse effects: a case report
Authors: Oike Takahiro , Ohno Tatsuya , Shirai Katsuyuki , Inoue Takashi , Nakano Takashi 
Published: July 2015

Key Clinical MessageInterstitial pneumonia (IP) sometimes precedes collagen vascular disease (CVD) onset. A patient with bladder cancer and mild IP received pelvic irradiation and experienced unexpectedly severe urinary toxicity followed by polymyositis onset and fatal IP exacerbation. Careful observation for “alarm adverse effects” of radiotherapy in IP patients may help predicting CVD onset.
Antibacterial activity of chlorhexidine after final irrigation with ethanol: CLSM and culture‐based method analysis
Authors: Suman Juliana Martins , Kuga Milton Carlos , Abreu Da Rosa Ricardo , Santini Manuela Favarin , Grazziotin‐Soares Renata , Montagner Francisco , Só Marcus ViníCius Reis 
Published: July 2015

ABSTRACTThis study investigated the effect of 95% ethanol on the antibacterial properties of 2% chlorexidine (CHX) over monospecies biofilm (Enterococcus faecalis) through a culture‐based method, and over multispecies biofilm using confocal laser scanning microscopy (CLSM). For monospecies model, E. faecalis biofilm was induced in 40 root canals. The irrigation procedures were: S—saline solution; S/CHX—saline solution + CHX; E—ethanol; and E/CHX—ethanol + CHX. Microbial sampling was performed at three periods: before (S1), immediately after (S2), and 72 h after the final flush (S3). For multispecies biofilm model, 28 sterilized bovine dentin blocks were fixed on a removable orthodontic device to allow intraoral biofilm development. Seven samples were used in each group. Statistical analysis was carried out by using the Kruskal–Wallis test and Dunn's test for multiple comparisons. There was a significant reduction in CFUs count immediately after the final flush (S2) in all experimental groups (P < 0.05). However, only S/CHX, E and E/CHX groups had CFU counts close to zero, without differences among them (P > 0.05). After 72h (S3), the S/CHX and E/CHX groups had CFU counts near zero (P > 0.05). The CFU count increased in S3 for S and E groups (P < 0.05). CLSM showed that the percentages of remaining live cells were similar in S/CHX, E, and E/CHX groups (P > 0.05). The S group had the highest percentage of live cells (P < 0.05). The 95% ethanol did not interfere in the antibacterial properties of 2% CHX over mono‐ and multispecies biofilms. Microsc. Res. Tech. 78:682–687, 2015. © 2015 Wiley Periodicals, Inc.
Risk factors for postoperative recurrence of intraductal papillary mucinous neoplasms of the pancreas based on a long‐term follow‐up study: proposals for follow‐up strategies
Authors: Yogi Tatsuji , Hijioka Susumu , Imaoka Hiroshi , Mizuno Nobumasa , Hara Kazuo , Tajika Masahiro , Tanaka Tsutomu , Ishihara Makoto , Shimizu Yasuhiro , Hosoda Waki , Yatabe Yasushi , Niwa Yasumasa , Yoshimura Kenichi , Bhatia Vikram , Fujita Jiro , Yamao Kenji 
Published: July 2015

AbstractBackgroundThe aim of this study was to examine the associations between postoperative clinicopathological features of intraductal papillary mucinous neoplasm (IPMN) and recurrence over a long follow‐up period.MethodsWe retrospectively assessed 153 IPMN patients who underwent resection.ResultsThe resected tumors showed low/intermediate‐grade dysplasia (LGD/IGD), high‐grade dysplasia (HGD), T1a (stromal invasion ≤5 mm), and invasive intraductal papillary mucinous carcinoma (IPMC), in 54.9%, 22.2%, 4.6%, and 18.3% of patients, respectively. The median follow‐up period after surgery was 46.4 (6.0–216.3) months, with an overall recurrence rate of 17.0%; the recurrence rates by histological type were 6.0%, 5.9%, 42.9%, and 57.1% for LGD/IGD, HGD, T1a, and invasive IPMC, respectively. Multivariate analysis revealed that recurrences related with tumor location, mural nodule size, presence of invasive cancer, lymph node metastasis, IPMN in the remnant pancreas, and main pancreatic duct dilatation after surgery. Recurrence occurred within the remnant pancreas in all LGD‐T1a patients and as extrapancreatic metastasis in all patients with invasive IPMC. Of the total recurrences, 15.4% occurred over 5 years postoperatively.ConclusionsThe postoperative follow‐up protocol for patients with LGD‐T1a should be similar to non‐resected IPMN, and that for invasive IPMC should be the same as for pancreatic ductal adenocarcinoma patients.