bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Use of StorAge Selection Functions to Assess Time‐Variant Travel Times in Lakes
Authors: Smith A. A. , Tetzlaff D. , Soulsby C. 
Published: July 2018

AbstractLakes can store water for long periods of time, which influences the transport of water and hydrologic tracers and changes catchment transit times downstream. However, the impact that the transit time of lakes has on catchment transit times has received little attention to date. We derived water and isotope mass balances for two lakes and examine the use of time‐variant transit time solutions with StorAge Selection functions to estimate the water ages of evaporation and lake outflows. We used the convolution of the StorAge Selection function transit time estimations with inflow transit times to estimate the transit times downstream of each lake. The lakes exhibited contrasting storage effects for discharge; with direct storage effects (newest water exiting during low flow) for a larger lake fed by a small catchment, and inverse storage effects (newest water exiting during high flow) for a smaller lake with a large catchment. The water and isotope mass balance yielded estimates of daily and annual evaporation fluxes, which were similar between the two lakes. The proposed framework is an effective tool to identify the effects of precipitation, surface inflow, and evaporation on the transit times for relatively small, shallow lakes, using a combination of water and isotope mass balance methods.
Methane Ebullition From Subtropical Peat: Testing an Ebullition Model Reveals the Importance of Pore Structure
Authors: Wright William , Ramirez Jorge A. , Comas Xavier 
Published: July 2018

AbstractThe role of subtropical peatlands as a source for methane gas is not well understood, partly due to uncertainties surrounding environmental controls on gas ebullition patterns. Past studies have pointed to an array of environmental factors controlling ebullition, although we have found that ebullition patterns can be replicated by a model considering only physical parameters of the peat matrix. Here we tested a computer model for gas ebullition and storage against a natural system for the first time, using a suite of field measurements in the Florida Everglades. Modeled ebullition showed patterns similar to those observed in the field in terms of frequency distribution and magnitude, specifically from areas of higher density peat fabric. These results suggest that the internal structure of the peat soil is an important control on spatial and temporal patterns of ebullition in the Everglades and should be considered when investigating environmental controls on ebullition patterns.
A Probabilistic Approach to Injection‐Induced Seismicity Assessment in the Presence and Absence of Flow Boundaries
Authors: Hosseini S. M. , Goebel T. H. W. , Jha B. , Aminzadeh F. 
Published: July 2018

AbstractInduced seismicity models that do not account for the effects of flow boundary conditions and uncertainty in initial stresses on the seismicity rate fail to predict the seismicity observed in real‐world injection sites. We present a model for the probabilistic assessment of induced seismicity that incorporates in situ stresses, pressure, and reservoir boundary conditions. The model considers a randomly distributed network of faults undergoing frictional failure due to pressure‐induced effective stresses. A semianalytical method is used to capture the effect of flow boundary conditions on pressure and seismicity rate based on pressure diffusion and Mohr‐Coulomb failure. We compare the model predictions with induced seismicity observations in Paradox Valley and German Continental Deep Drilling Program. We demonstrate that differences in the flow boundary conditions can drastically change the seismic response to injection. The strongest difference is observed for a closed boundary reservoir for which the induced seismicity rate increases exponentially.
Coastal Sulfur Plumes off Peru During El Niño, La Niña, and Neutral Phases
Authors: Ohde T. 
Published: July 2018

AbstractFor the first time, the impact of the El Niño‐Southern Oscillation (ENSO) on the surface sulfur plumes off the Peruvian upwelling system has been studied. The investigations demonstrated a strong correlation between the ENSO and the sulfur plumes in the coastal areas of Callao and Pisco. During the El Niño phases, the sulfur plumes disappeared almost completely because of equatorial remotely forced oxygenation episodes. The La Niña events were associated with strong oxygen deficiency over the Peruvian shelf, supporting the formation of hydrogen sulfide and, consequently, the occurrence of sulfur plumes. This impact was smaller at Callao, because the La Niña phases in this coastal area were interrupted by weak oxygenation events. During the neutral phases, oxygen‐poor waters were also present in the Peruvian shelf areas, promoting the large size of sulfur plumes. However, they were not forced by the remotely driven processes resulting from ENSO phenomena.
In Situ Observations of Phase Changes in Shock Compressed Forsterite
Authors: Newman M. G. , Kraus R. G. , Akin M. C. , Bernier J. V. , Dillman A. M. , Homel M. A. , Lee S. , Lind J. , Mosenfelder J. L. , Pagan D. C. , Sinclair N. W. , Asimow P. D. 
Published: July 2018

AbstractShockwave data on mineral‐forming compounds such as Mg2SiO4 are essential for understanding the interiors of Earth and other planets, but correct interpretation of these data depends on knowing the phase assemblage being probed at high pressure. Hence, direct observations of the phase or phases making up the measured states along the forsterite Hugoniot are essential to assess whether kinetic factors inhibit the achievement of the expected equilibrium, phase‐separated assemblage. Previous shock recovery experiments on forsterite, which has orthorhombic space group Pbnm, show discrepant results as to whether forsterite undergoes segregation into its equilibrium phase assemblage of compositionally distinct structures upon shock compression. Here we present the results of plate impact experiments on polycrystalline forsterite conducted at the Dynamic Compression Sector of the Advanced Photon Source. In situ X‐ray diffraction measurements were used to probe the crystal structure(s) in the shock state and to investigate potential decomposition into periclase and bridgmanite. In contrast to previous interpretations of the forsterite shock Hugoniot, we find that forsterite does not decompose but instead reaches the forsterite III structure, which is a metastable structure of Mg2SiO4 with orthorhombic space group Cmc21.
Meridional Shift of the Oyashio Extension Front in the Past 36 Years
Authors: Wu Baolan , Lin Xiaopei , Qiu Bo 
Published: July 2018

AbstractThe meridional shift of Oyashio Extension (OE) front in the past 36 years was analyzed by using the high‐resolution Optimum Interpolation SST data. The annual mean OE front has moved northward in its eastern part (between 157°E and 172°E) by 0.018°/year but no obvious poleward shift in the western OE front (between 145°E and 157°E). It is shown that the trade wind became stronger and broader, and the whole wind field moved northward in the past 36 years, shifting the zero wind stress curl line (or the zero Sverdrup streamline) and the eastern OE front northward. The above mechanism is confirmed by a 1.5‐layer reduced‐gravity model simulation as well as the altimetry data. Meanwhile, the local Ekman heat transport anomaly due to the wind field changes is found to be one of the contributors to the northward shift of the eastern OE front. However, both wind stress curl and local Ekman heat transport anomalies do not favor northward shift of the western OE front.
Detection of Intraseasonal Oscillations in SMAP Salinity in the Bay of Bengal
Authors: Subrahmanyam Bulusu , Trott Corinne B. , Murty V. S. N. 
Published: July 2018

AbstractAnalysis of Soil Moisture Active Passive (SMAP) mission derived sea surface salinity (SSS) during April 2015 to December 2017 in the Bay of Bengal (BoB) shows first revelation of new insight of existence of 30‐ to 90‐day and 10‐ to 20‐day period Intraseasonal Oscillations (ISOs) in SSS—all phase‐locked during August–December. The seasonal SMAP SSS anomaly (SSSA) minimum (−0.5 to −1.0 practical salinity unit, psu) occurs in October and exhibits year‐to‐year variation, while SSSA maximum (0.5 psu) occurs in June during 2015–2017. Interestingly, these ISOs encompass the negative phase of seasonal SSSA minimum (August–December) in a year and are related to seasonal variations in river discharge and surface freshwater flux (precipitation and evaporation), that in turn are impacted by the climatic events. Wavelet analysis reveals larger amplitude (−0.2 to 0.35 psu) 30‐ to 90‐day ISO in northern BoB during August–November. The northward propagation of the SSS ISOs would modulate the postmonsoon air‐sea interactions across the BoB.
Monsoonal Forcing of European Ice‐Sheet Dynamics During the Late Quaternary
Authors: Kaboth‐Bahr Stefanie , Bahr André , Zeeden Christian , Toucanne Samuel , Eynaud Frédérique , Jiménez‐Espejo Francisco , Röhl Ursula , Friedrich Oliver , Pross Jörg , Löwemark Ludvig , Lourens Lucas J. 
Published: July 2018

AbstractThe dynamics of Northern Hemisphere ice sheets during Late Quaternary glacials have yet been dominantly examined from a Laurentide Ice Sheet perspective, which helped shaping the idea of moisture‐starved glacials and small‐scale ice volume variability. However, the waxing and waning of the European Ice Sheet (EIS) casts doubt on this perception. Understanding EIS dynamics under glacial boundary conditions is crucial because its meltwater pulses influence global climate by weakening deepwater formation in the North Atlantic Ocean. Here we show that the advection of subtropical water toward the continental margin of western Europe lead to enhanced moisture availability on the continent and fueled the growth of EIS lobes during glacials. This warm‐water pooling was caused by monsoonally paced enhanced Mediterranean Outflow Water (MOW) entrainment that dragged subtropical surface waters toward the European margin. This mechanism presents a yet unrecognized marine‐terrestrial pathway that allows low‐latitude forcing to shape high‐latitude glaciations.
Laboratory Observations of Tremor‐Like Events Generated During Preslip
Authors: Zhuo Yan‐Qun , Liu Peixun , Chen Shunyun , Guo Yanshuang , Ma Jin 
Published: July 2018

AbstractThe origins of tremors and their relation to fault slip and impending earthquakes remain unclear. Laboratory studies on tremor‐like acoustic emission events generated during preslip may shed some light on the above issues. We conducted stick‐slip experiments and observed tremor‐like events and preslip in the laboratory. The results show the following. (1) The dominant frequency of tremor‐like events increases with accelerating preslip. (2) The evolution of tremor‐like events is spatiotemporally consistent with that of preslip. (3) Interactions between preslip and high‐frequency events indicate the formation of a positive feedback effect between the expansion of preslip and failure of asperities, which leads to stick‐slip instability. Thus, we propose that tremors may be caused by stress variations derived from asperity interactions along fault surfaces at dry conditions. The increasing dominant frequency of tremors may imply the accelerating preslip of an upcoming earthquake.
Integrated genetic and epigenetic analysis of myxofibrosarcoma
Authors: Ogura Koichi , Hosoda Fumie , Arai Yasuhito , Nakamura Hiromi , Hama Natsuko , Totoki Yasushi , Yoshida Akihiko , Nagai Momoko , Kato Mamoru , Arakawa Erika , Mukai Wakako , Rokutan Hirofumi , Kawai Akira , Tanaka Sakae , Shibata Tatsuhiro 
Published: July 2018

AbstractMyxofibrosarcoma (MFS) is a common adult soft tissue sarcoma characterized by an infiltrative growth pattern and a high local recurrence rate. Here we report the genetic and epigenetic landscape of MFS based on the results of whole-exome sequencing (N = 41), RNA sequencing (N = 29), and methylation analysis (N = 41), using 41 MFSs as a discovery set, and subsequent targeted sequencing of 140 genes in the entire cohort of 99 MFSs and 17 MFSs' data from TCGA. Fourteen driver genes are identified, including potentially actionable therapeutic targets seen in 37% of cases. There are frequent alterations in p53 signaling (51%) and cell cycle checkpoint genes (43%). Other conceivably actionable driver genes includingATRX,JAK1,NF1,NTRK1, and novel oncogenicBRAFfusion gene are identified. Methylation patterns cluster into three subtypes associated with unique combinations of driver mutations, clinical outcomes, and immune cell compositions. Our results provide a valuable genomic resource to enable the design of precision medicine for MFS.
Thresholds of lake and reservoir connectivity in river networks control nitrogen removal
Authors: Schmadel Noah M. , Harvey Judson W. , Alexander Richard B. , Schwarz Gregory E. , Moore Richard B. , Eng Ken , Gomez-Velez Jesus D. , Boyer Elizabeth W. , Scott Durelle 
Published: July 2018

AbstractLakes, reservoirs, and other ponded waters are ubiquitous features of the aquatic landscape, yet their cumulative role in nitrogen removal in large river basins is often unclear. Here we use predictive modeling, together with comprehensive river water quality, land use, and hydrography datasets, to examine and explain the influences of more than 18,000 ponded waters on nitrogen removal through river networks of the Northeastern United States. Thresholds in pond density where ponded waters become important features to regional nitrogen removal are identified and shown to vary according to a ponded waters’ relative size, network position, and degree of connectivity to the river network, which suggests worldwide importance of these new metrics. Consideration of the interacting physical and biological factors, along with thresholds in connectivity, reveal where, why, and how much ponded waters function differently than streams in removing nitrogen, what regional water quality outcomes may result, and in what capacity management strategies could most effectively achieve desired nitrogen loading reduction.
In-orbit operation of an atomic clock based on laser-cooled 87Rb atoms
Authors: Liu Liang , Lü De-Sheng , Chen Wei-Biao , Li Tang , Qu Qiu-Zhi , Wang Bin , Li Lin , Ren Wei , Dong Zuo-Ren , Zhao Jian-Bo , Xia Wen-Bing , Zhao Xin , Ji Jing-Wei , Ye Mei-Feng , Sun Yan-Guang , Yao Yuan-Yuan , Song Dan , Liang Zhao-Gang , Hu Shan-Jiang , Yu Dun-He , Hou Xia , Shi Wei , Zang Hua-Guo , Xiang Jing-Feng , Peng Xiang-Kai , Wang Yu-Zhu 
Published: July 2018

AbstractAtomic clocks based on laser-cooled atoms are widely used as primary frequency standards. Deploying such cold atom clocks (CACs) in space is foreseen to have many applications. Here we present tests of a CAC operating in space. In orbital microgravity, the atoms are cooled, trapped, launched, and finally detected after being interrogated by a microwave field using the Ramsey method. Perturbing influences from the orbital environment on the atoms such as varying magnetic fields and the passage of the spacecraft through Earth’s radiation belt are also controlled and mitigated. With appropriate parameters settings, closed-loop locking of the CAC is realized in orbit and an estimated short-term frequency stability close to 3.0 × 10−13τ−1/2 has been attained. The demonstration of the long-term operation of cold atom clock in orbit opens possibility on the applications of space-based cold atom sensors.
Mie-coupled bound guided states in nanowire geometric superlattices
Authors: Kim Seokhyoung , Kim Kyoung-Ho , Hill David J. , Park Hong-Gyu , Cahoon James F. 
Published: July 2018

AbstractAll-optical operation holds promise as the future of computing technology, and key components include miniaturized waveguides (WGs) and couplers that control narrow bandwidths. Nanowires (NWs) offer an ideal platform for nanoscale WGs, but their utility has been limited by the lack of a comprehensive coupling scheme with band selectivity. Here, we introduce a NW geometric superlattice (GSL) that allows narrow-band guiding in Si NWs through coupling of a Mie resonance with a bound-guided state (BGS). Periodic diameter modulation creates a Mie-BGS-coupled excitation that manifests as a scattering dark state with a pronounced scattering dip in the Mie resonance. The frequency of the coupled mode, tunable from the visible to near-infrared, is determined by the pitch of the GSL. Using a combined GSL-WG system, we demonstrate spectrally selective guiding and optical switching and sensing at telecommunication wavelengths, highlighting the potential to use NW GSLs for the design of on-chip optical components.
Changes in low-level neural properties underlie age-dependent visual decision making
Authors: Arani Elahe , van Ee Raymond , van Wezel Richard 
Published: July 2018

AbstractAging typically slows down cognitive processes, specifically those related to perceptual decisions. However, the neurobiological mechanisms underlying these age-associated changes are still elusive. To address this, we studied the effect of aging on both perceptual and binocular rivalry in various presentation conditions. Two age groups of participants reported their spontaneous percept switches during continuous presentation and percept choices during intermittent presentation. We find no significant age effect on the mean and cumulative frequencies of percept switch durations under continuous presentation. However, the data show a significant age effect on coefficient of variation, ratio of standard deviation to mean of percept durations. Our results also reveal that the alternation rate for percept choices significantly declines at an older age under intermittent presentation. The latter effect is even more pronounced at shorter inter-stimulus durations. These results together with the predictions of existing neural models for bistable perception imply that age-dependency of visual perceptual decisions is caused by shifts in neural adaptation and noise, not by a change in inhibition strength. Thus, variation in the low-level neural properties, adaptation and noise, cause age-dependent properties in visual perceptual decisions.
Assessment of the efficacy of different procedures that remove and disassemble alpha-synuclein, tau and A-beta fibrils from laboratory material and surfaces
Authors: Fenyi Alexis , Coens Audrey , Bellande Tracy , Melki Ronald , Bousset Luc 
Published: July 2018

Abstractα-synuclein fibrillar polymorphs, Tau and Aß 1–42 fibrillar assemblies have been shown to propagate, amplify and trigger the formation of protein deposits reminiscent of those present within the central nervous system of patients developing synucleinopathies, tauopathies and amyloid plaques after injection intracerebrally, intramuscularly, intraperitoneally or within the blood stream of model animals. They are thus hazardous and there is need for decontamination and inactivation procedures for laboratory surfaces and non-disposable material. We assessed the effectiveness of different reagents to clean and disassemble potentially pathogenic assemblies adsorbed on non-disposable materials in laboratories. We show that commercial detergents and SDS are way more suited to detach α-synuclein fibrillar polymorphs, Tau and Aß 1–42 fibrillar assemblies from contaminated surfaces and disassemble the fibrils than methods designed to decrease PrP prion infectivity. Our observations reveal that the choice of the most adapted cleaning procedure for one given protein assembly or fibrillar polymorph should integrate detergent’s cleaning efficiency, material compatibility and capacity to dismantle assemblies. We provide an integrated representation where desorption and neutralization efficacy and surface compatibility are combined to facilitate the choice of the most adapted decontamination procedure. This representation, together with good laboratory practices, contributes to reducing potential health hazards associated to manipulating protein assemblies with prion-like properties.
Temporal evolution of hydroclimatic teleconnection and a time-varying model for long-lead prediction of Indian summer monsoon rainfall
Authors: Dutta Riya , Maity Rajib 
Published: July 2018

AbstractSeveral cases of failure in the prediction of Indian Summer Monsoon Rainfall (ISMR) are the major concern for long-lead prediction. We propose that this is due to the temporal evolution of association/linkage (inherent concept of temporal networks) with various factors and climatic indices across the globe, such as El Niño-Southern Oscillation (ENSO), Equatorial Indian Ocean Oscillation (EQUINOO), Atlantic Multidecadal Oscillation (AMO), North Atlantic Oscillation (NAO), Pacific Decadal Oscillation (PDO) etc. Static models establish time-invariant (permanent) connections between such indices (predictors) and predictand (ISMR), whereas we hypothesize that such systems are temporally varying in nature. Considering hydroclimatic teleconnection with two major climate indices, ENSO and EQUINOO, we showed that the temporal persistence of the association is as low as three years. As an application of this concept, a statistical time-varying model is developed and the prediction performance is compared against its static counterpart (time-invariant model). The proposed approach is able to capture the ISMR anomalies and successfully predicts the severe drought years too. Specifically, 64% more accurate performance (in terms of RMSE) is achievable by the recommended time-varying approach as compared to existing time-invariant concepts.
Structural and functional studies of the metalloregulator Fur identify a promoter-binding mechanism and its role in Francisella tularensis virulence
Authors: Pérard J. , Nader S. , Levert M. , Arnaud L. , Carpentier P. , Siebert C. , Blanquet F. , Cavazza C. , Renesto P. , Schneider D. , Maurin M. , Coves J. , Crouzy S. , Michaud-Soret I. 
Published: July 2018

AbstractFrancisella tularensis is a Gram-negative bacterium causing tularaemia. Classified as possible bioterrorism agent, it may be transmitted to humans via animal infection or inhalation leading to severe pneumonia. Its virulence is related to iron homeostasis involving siderophore biosynthesis directly controlled at the transcription level by the ferric uptake regulator Fur, as presented here together with the first crystal structure of the tetrameric F. tularensis Fur in the presence of its physiological cofactor, Fe2+. Through structural, biophysical, biochemical and modelling studies, we show that promoter sequences of F. tularensis containing Fur boxes enable this tetrameric protein to bind them by splitting it into two dimers. Furthermore, the critical role of F. tularensis Fur in virulence and pathogenesis is demonstrated with a fur-deleted mutant showing an attenuated virulence in macrophage-like cells and mice. Together, our study suggests that Fur is an attractive target of new antibiotics that attenuate the virulence of F. tularensis.