bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatiotemporal Variations of Ambient Concentrations of Trace Elements in a Highly Polluted Region of China
Authors: Liu Shuhan , Zhu Chuanyong , Tian Hezhong , Wang Yuxuan , Zhang Kai , Wu Bobo , Liu Xiangyang , Hao Yan , Liu Wei , Bai Xiaoxuan , Lin Shumin , Wu Yiming , Shao Panyang , Liu Huanjia 
Published: March 2019

AbstractAnthropogenic emissions of trace elements (TEs) into the atmosphere have warranted global concern due to their adverse effects on human health and the ecosystem. We adapted the Weather Research and Forecasting (WRF) and Models‐3/Community Multiscale Air Quality (CMAQ) modeling system to predict the spatial and temporal concentrations of 11 TEs (arsenic, selenium, lead, cadmium, chromium, nickel, antimony, manganese, cobalt, copper, and zinc) in fine particulate matter (PM2.5) in January, April, July, and October of 2012 over Beijing, Tianjin, and Hebei (BTH) region of Northern China, one of the most polluted areas in China with frequent occurrences of haze episodes. A localized emission inventory that includes both conventional air pollutants and TEs established by our previous study was used in the model. Predicted concentrations of TEs were compared with observations collected at a site located in Beijing Normal University. The results show that arsenic, selenium, lead, copper, nickel, and zinc predictions better agree with observations made in both months. Manganese, antimony, and cobalt simulations display different abilities to reproduce observations between months. Chromium predictions have lower correlation coefficients. Cadmium predictions, similar to previous findings, show the least ability to reproduce observations. According to the model predictions, higher concentrations of TEs are primarily identified in the central and southern areas of the BTH region, and seasonally January sees the highest TEs. Potential causes for high concentrations of TEs were examined by evaluating emissions and contributions from major sources. Finally, specific countermeasures for emissions reduction of TEs were proposed.
Corrections of Radiosonde‐Based Precipitable Water Using Ground‐Based GPS and Applications on Historical Radiosonde Data Over China
Authors: Zhang Weixing , Lou Yidong , Cao Yunchang , Liang Hong , Shi Chuang , Huang Jinfang , Liu Wenxuan , Zhang Yong , Fan Binbin 
Published: March 2019

AbstractThe usage of radiosonde humidity data in climate studies and atmospheric reanalysis has been greatly hampered by the inhomogeneity issue mainly caused by radiosonde sensor changes. In this work, high‐quality precipitable water (PW) products derived from a national Global Positioning System (GPS) network in China covering the period from 1999 to 2015 were used to quantify errors in radiosonde‐derived PW products for different radiosonde types. Correlations between PW biases and factors including the station location, mean PW, weighted mean temperature (Tm), and solar elevation angle were carefully analyzed. Biases in PW products derived from the mechanical radiosondes (GZZ2, used at most stations before 2001) show strong correlations with the station elevation and Tm, and a PW correction model was then developed. For GTS1 and GTS1‐1 (widely used in current operational system), due to the unobvious correlations between PW biases and these factors, corrections were estimated as mean values of PW biases at all collocated stations. For GTS1‐2, GTS2(U)‐1, and TD2‐A (used at a few stations), subject to insufficient GPS‐radiosonde collocated stations, they are left uncorrected. The corrected radiosonde‐derived PW products (referred as Corr) were compared with the uncorrected products (referred as Raw) as well as PW products derived from the radiosonde data homogenized using the method proposed by Dai et al. (2011; referred as Dai, https://doi.org/10.1175/2010JCLI3816.1). Corr products show better agreements with GPS‐derived PW than Raw and Dai, and artificial significant decreasing PW trends in the recent two decades in Raw products were greatly reduced after applying the proposed corrections.
Analysis of Dual Nature of Heat Flux Predicted by Monin‐Obukhov Similarity Theory: An Impact of Empirical Forms of Stability Correction Functions
Authors: Srivastava Piyush , Sharan Maithili 
Published: March 2019

AbstractThe behavior of sensible heat flux H with stability parameter ζ in the stable atmospheric surface layer is analyzed within the framework of Monin‐Obukhov similarity theory (MOST). Using MOST equations, H is expressed as a function of ζ and wind shear ∂U/∂z. A systematic mathematical analysis is carried out to analyze the behavior of H with ζ utilizing the linear as well as various nonlinear empirical functional forms of the similarity functions. In case of linear form, for a given value of H, two different values of ζ along with the “downward heat flux maximum” with a unique critical point are found to occur. However, for the other selected empirical similarity functions, more than two values of ζ having the same magnitude of H may occur suggesting the existence of multiple critical points. Further, the observational variation of H with ζ is analyzed using data from three different sites. Data suggest the existence of two different stability regimes for the same magnitude of heat flux. However, the data do not support the existence of multiple values of ζ for the same magnitude of H, as predicted by MOST with the other selected empirical forms of similarity functions. This suggests that the phenomenon of existence of downward heat flux maximum, as predicted by MOST equations, depends on the functional form of the similarity functions, and it appears to break down for some selected empirical forms of similarity functions under very stable conditions.
Surface Meteorological Conditions and Boundary Layer Height Variations During an Air Pollution Episode in Nanjing, China
Authors: Yin J. , Gao C. Y. , Hong J. , Gao Z. , Li Y. , Li X. , Fan S. , Zhu B. 
Published: March 2019

AbstractThe evolution of planetary boundary layer (PBL) was investigated using observations from a laser ceilometer, an eddy covariance system, and an automatic meteorological station in the north of Nanjing city during an air pollution episode in 2016–2017 winter. Based on 7‐day observation under clean to polluted day, we recorded the temporal variations of backscatter signals observed by the ceilometer, and then intercompared the planetary boundary layer height (PBLH) retrieved from individual methods. The results show that backscatter signal gradient, standard deviation, and wavelet transform analysis methods generated similar PBLH values and PBL diurnal variation patterns. Moreover, the PBL structure varied diurnally, with distinct patterns corresponding to clean and polluted days. Based on these measurements, the relationships between PBLH, weather conditions, and contaminants were analyzed. Results show that on clean days, strong surface turbulence exchange makes the PBL fully developed and makes the PBLH increase sharply after sunrise, with a maximum of 1,483 m; on polluted days, stable synoptic conditions and the weaker wind speeds facilitated the accumulation of air pollutants, leading to smaller net surface radiation and weaker turbulence. Consequently, these conditions during polluted days led to lower PBLH values, which were typically less than 900 m.
Sensitivity of Simulated Aerosol Properties Over Eastern North America to WRF‐Chem Parameterizations
Authors: Crippa P. , Sullivan R. C. , Thota A. , Pryor S. C. 
Published: March 2019

AbstractAerosol properties and their climatic feedbacks are characterized by high uncertainty in both global and regional model simulations. We explore sources of uncertainty in the representation of aerosol properties using an ensemble of simulations performed at 24‐km resolution with WRF‐Chem over eastern North America. The sensitivity of aerosol optical depth (AOD) and near‐surface fine particle concentrations (PM2.5) to planetary boundary layer (PBL) and aerosol schemes (modal with secondary organic aerosol versus sectional but excluding secondary organic aerosol), as well as different emission inventories (National Emission Inventory [NEI] 2005 versus 2011) is examined. We quantify the spread among ensemble members with respect to the model setup and compute statistical metrics to identify the run configuration that exhibits greatest fidelity relative to observations of aerosol and meteorological properties. Use of the Modal Aerosol Dynamics Model for Europe/Secondary Organic Aerosol Model scheme leads to highest agreement with Moderate Resolution Imaging Spectroradiometer clear‐sky AOD observations particularly when the 2005 NEI is used (with either PBL scheme). These members exhibit small negative mean fractional bias over the simulation domain (<2%) and relatively high spatial correlation in summertime mean monthly AOD (>0.5). The aerosol scheme and NEI dominate the ensemble spread in AOD. Near‐surface PM2.5 is also dependent on PBL scheme and is best reproduced in runs adopting a sectional approach and emissions for 2011. Thus, WRF‐Chem configuration associated with highest agreement with AOD observations is not the same as for PM2.5, possibly reflecting the importance of columnar water vapor in dictating AOD or other unexplored uncertainties linking surface mass concentrations to column optical properties.
Hot Spots of Climate Extremes in the Future
Authors: Xu Lianlian , Wang Aihui , Wang Dan , Wang Huijun 
Published: March 2019

AbstractA Regional Extreme Climatic Change Index (RECCI), simultaneously considering the changes in intensity, frequency and interannual variability of three major extreme climatic variables (i.e., precipitation, temperature and wind speed), is constructed to represent regional changes of climate extremes in response to global warming. First, the daily outputs from 13 models in the Coupled Model Intercomparison Project phase 5 project in both historical and future simulations under the Representative Concentration Pathway 8.5 scenario are used to compute the extreme climatic indices. Second, the RECCI is computed on both annual and seasonal time scales during three periods (i.e., 2016–2035, 2046–2065 and 2080–2099) over 26 subregions. Finally, the spatiotemporal change of the RECCI is investigated, and then, the 26 subregions are classified into four categories for each period. The first category with the largest RECCI value is very sensitive to global warming, which is called hot spots of climate extremes. The results show that most hot spots are not time invariant on annual and seasonal time scales with some exceptions. On the annual time scale, the Amazon Basin is the only persistent hot spot in all three periods. For the seasonal time scale in March‐April‐May, the climate extremes in the Amazon Basin always display the strongest responsiveness to global warming, and the Eastern Africa is the only persistent hot spot in June‐July‐August in three periods. Similar results are also found for the other two seasons and periods. In addition, the change in extreme temperature is crucial over the East Asia with change in frequency prominent.
Multicycle Dynamics of the Aksay Bend Along the Altyn Tagh Fault in Northwest China: 2. The Realistically Complex Fault Geometry
Authors: Duan Benchun , Liu Zaifeng , Elliott Austin J. 
Published: March 2019

AbstractWe study rupture behavior of the Aksay bend along the Altyn Tagh fault in northwest China over multiple earthquake cycles. A finite element method is used to numerically simulate spontaneous rupture during a coseismic process, and a viscoelastic model is used to analytically compute the fault stresses during an interseismic process. We find that the Aksay bend is an effective barrier to halt dynamically propagating ruptures from either side of the bend within a range of model parameters, with statistically only about 10% of ruptures jumping across the bend and propagating through almost the entire local fault system. Secondary complexities in fault geometry within the bend, in particular those portions that align relatively well with the regional strike of the fault system, play a critical role in these occasionally jumping ruptures. Well‐developed fault patches with shear stress close to shear strength allow dynamically propagating ruptures to penetrate into the bend and are more susceptible to the dynamic triggering that enables rupture to jump across the bend onto the other strand. We identify additionally nine large rupture scenarios with different occurrences, and most of them rupture one strand outside the bend with triggered slip on some portions of the same or the other strand within the bend. Slip rate distributions from the models show significantly reduced fault slip within the bend and a permanently locked portion on the south strand near the peak of the Altun Mountains. These findings have important implications for seismic hazard assessments of complex fault systems worldwide.
The Tectonics and Active Faulting of Haiti from Seismicity and Tomography
Authors: Possee Daniel , Keir Derek , Harmon Nicholas , Rychert Catherine , Rolandone Frédérique , Leroy Sylvie , Corbeau Jordane , Stuart Graham , Calais Eric , Illsley‐Kemp Finnigan , Boisson Dominique , Momplaisir Roberte , Prépetit Claude 
Published: March 2019

AbstractOblique convergence of the Caribbean and North American plates has partitioned strain across a major transpressional fault system that bisects the island of Hispaniola. The devastating MW 7.0, 2010 earthquake that struck southern Haiti, rupturing an unknown fault, highlighted our limited understanding of regional fault segmentation and its link to plate boundary deformation. Here we assess seismic activity and fault structures across Haiti using data from 33 broadband seismic stations deployed for 16 months. We use traveltime tomography to obtain relocated hypocenters and models of Vp and Vp/Vs crustal structure. Earthquake locations reveal two clusters of seismic activity. The first corresponds to aftershocks of the 2010 earthquake and delineates faults associated with that rupture. The second cluster shows shallow activity north of Lake Enriquillo (Dominican Republic), interpreted to have occurred on a north‐dipping thrust fault. Crustal seismic velocities show a narrow low‐velocity region with an increased Vp/Vs ratio (1.80–1.85) dipping underneath the Massif de la Selle, which coincides with a southward‐dipping zone of hypocenters to a depth of 20 km beneath southern Haiti. Our observations of seismicity and crustal structure in southern Haiti suggests a transition in the Enriquillo fault system from a near vertical strike‐slip fault along the Southern Peninsula to a southward‐dipping oblique‐slip fault along the southern border of the Cul‐de‐Sac‐Enriquillo basin. This result, consistent with recent geodetic results but at odds with the classical seismotectonic interpretation of the Enriquillo fault system, is an important constraint in our understanding of regional seismic hazard.
Two types of amyloidosis presenting in a single patient: a case series
Authors: Sidiqi M. Hasib , McPhail Ellen D. , Theis Jason D. , Dasari Surendra , Vrana Julie A. , Drosou Maria Eleni , Leung Nelson , Hayman Suzanne , Rajkumar S. Vincent , Warsame Rahma , Ansell Stephen M. , Gertz Morie A. , Grogan Martha , Dispenzieri Angela 
Published: March 2019

AbstractThe amyloidoses are a group of disorders with overlapping clinical presentations, characterized by aggregation and tissue deposition of misfolded proteins. The nature and source of the amyloidogenic protein determines therapy, therefore correct subtyping is critical to patient management. We report the clinicopathologic features of nine patients diagnosed with two amyloid types confirmed by liquid chromatography-coupled tandem mass spectrometry. The most common types were transthyrethin (n = 9) and immunoglobulin-derived (n = 7). Two patients did not have immunoglobulin-derived amyloidosis despite the presence of a monoclonal gammopathy. Eight patients were diagnosed with two types concurrently, and one patient had an 11-year interval between diagnoses. Histopathological distribution of amyloid was variable with vascular, interstitial, and periosteal deposits seen. Identification of a second type was incidental in seven patients, but led to genetic counselling in one patient and therapy directed at both amyloid subtypes in another. With longer survival of myeloma and AL amyloidosis patients and increasing prevalence of patients with wild-type transthyretin amyloidosis due to an aging population, the phenomenon of two amyloid types in a single patient will be encountered more frequently. In light of revolutionary new therapies for transthyretin amyloidosis (patisiran, tafamidis, and inotersen), recognition of dual amyloid types is highly clinically relevant.
Quantum electrodynamics at room temperature coupling a single vibrating molecule with a plasmonic nanocavity
Authors: Ojambati Oluwafemi S. , Chikkaraddy Rohit , Deacon William D. , Horton Matthew , Kos Dean , Turek Vladimir A. , Keyser Ulrich F. , Baumberg Jeremy J. 
Published: March 2019

AbstractInteractions between a single emitter and cavity provide the archetypical system for fundamental quantum electrodynamics. Here we show that a single molecule of Atto647 aligned using DNA origami interacts coherently with a sub-wavelength plasmonic nanocavity, approaching the cooperative regime even at room temperature. Power-dependent pulsed excitation reveals Rabi oscillations, arising from the coupling of the oscillating electric field between the ground and excited states. The observed single-molecule fluorescent emission is split into two modes resulting from anti-crossing with the plasmonic mode, indicating the molecule is strongly coupled to the cavity. The second-order correlation function of the photon emission statistics is found to be pump wavelength dependent, varying from g(2)(0) = 0.4 to 1.45, highlighting the influence of vibrational relaxation on the Jaynes-Cummings ladder. Our results show that cavity quantum electrodynamic effects can be observed in molecular systems at ambient conditions, opening significant potential for device applications.
Urban pollution greatly enhances formation of natural aerosols over the Amazon rainforest
Authors: Shrivastava Manish , Andreae Meinrat O. , Artaxo Paulo , Barbosa Henrique M. J. , Berg Larry K. , Brito Joel , Ching Joseph , Easter Richard C. , Fan Jiwen , Fast Jerome D. , Feng Zhe , Fuentes Jose D. , Glasius Marianne , Goldstein Allen H. , Alves Eliane Gomes , Gomes Helber , Gu Dasa , Guenther Alex , Jathar Shantanu H. , Kim Saewung , Liu Ying , Lou Sijia , Martin Scot T. , McNeill V. Faye , Medeiros Adan , de Sá Suzane S. , Shilling John E. , Springston Stephen R. , Souza R. A. F. , Thornton Joel A. , Isaacman-VanWertz Gabriel , Yee Lindsay D. , Ynoue Rita , Zaveri Rahul A. , Zelenyuk Alla , Zhao Chun 
Published: March 2019

AbstractOne of the least understood aspects in atmospheric chemistry is how urban emissions influence the formation of natural organic aerosols, which affect Earth’s energy budget. The Amazon rainforest, during its wet season, is one of the few remaining places on Earth where atmospheric chemistry transitions between preindustrial and urban-influenced conditions. Here, we integrate insights from several laboratory measurements and simulate the formation of secondary organic aerosols (SOA) in the Amazon using a high-resolution chemical transport model. Simulations show that emissions of nitrogen-oxides from Manaus, a city of ~2 million people, greatly enhance production of biogenic SOA by 60–200% on average with peak enhancements of 400%, through the increased oxidation of gas-phase organic carbon emitted by the forests. Simulated enhancements agree with aircraft measurements, and are much larger than those reported over other locations. The implication is that increasing anthropogenic emissions in the future might substantially enhance biogenic SOA in pristine locations like the Amazon.
Shuttling a single charge across a one-dimensional array of silicon quantum dots
Authors: Mills A. R. , Zajac D. M. , Gullans M. J. , Schupp F. J. , Hazard T. M. , Petta J. R. 
Published: March 2019

AbstractSignificant advances have been made towards fault-tolerant operation of silicon spin qubits, with single qubit fidelities exceeding 99.9%, several demonstrations of two-qubit gates based on exchange coupling, and the achievement of coherent single spin-photon coupling. Coupling arbitrary pairs of spatially separated qubits in a quantum register poses a significant challenge as most qubit systems are constrained to two dimensions with nearest neighbor connectivity. For spins in silicon, new methods for quantum state transfer should be developed to achieve connectivity beyond nearest-neighbor exchange. Here we demonstrate shuttling of a single electron across a linear array of nine series-coupled silicon quantum dots in ~50 ns via a series of pairwise interdot charge transfers. By constructing more complex pulse sequences we perform parallel shuttling of two and three electrons at a time through the array. These experiments demonstrate a scalable approach to physically transporting single electrons across large silicon quantum dot arrays.
Loss of a proteostatic checkpoint in intestinal stem cells contributes to age-related epithelial dysfunction
Authors: Rodriguez-Fernandez Imilce A. , Qi Yanyan , Jasper Heinrich 
Published: March 2019

AbstractA decline in protein homeostasis (proteostasis) has been proposed as a hallmark of aging. Somatic stem cells (SCs) uniquely maintain their proteostatic capacity through mechanisms that remain incompletely understood. Here, we describe and characterize a ‘proteostatic checkpoint’ in Drosophila intestinal SCs (ISCs). Following a breakdown of proteostasis, ISCs coordinate cell cycle arrest with protein aggregate clearance by Atg8-mediated activation of the Nrf2-like transcription factor cap-n-collar C (CncC). CncC induces the cell cycle inhibitor Dacapo and proteolytic genes. The capacity to engage this checkpoint is lost in ISCs from aging flies, and we show that it can be restored by treating flies with an Nrf2 activator, or by over-expression of CncC or Atg8a. This limits age-related intestinal barrier dysfunction and can result in lifespan extension. Our findings identify a new mechanism by which somatic SCs preserve proteostasis, and highlight potential intervention strategies to maintain regenerative homeostasis.
Topological transitions among skyrmion- and hedgehog-lattice states in cubic chiral magnets
Authors: Fujishiro Y. , Kanazawa N. , Nakajima T. , Yu X. Z. , Ohishi K. , Kawamura Y. , Kakurai K. , Arima T. , Mitamura H. , Miyake A. , Akiba K. , Tokunaga M. , Matsuo A. , Kindo K. , Koretsune T. , Arita R. , Tokura Y. 
Published: March 2019

AbstractManipulating topological spin textures is a key for exploring unprecedented emergent electromagnetic phenomena. Whereas switching control of magnetic skyrmions, e.g., the transitions between a skyrmion-lattice phase and conventional magnetic orders, is intensively studied towards development of future memory device concepts, transitions among spin textures with different topological orders remain largely unexplored. Here we develop a series of chiral magnets MnSi1−xGex, serving as a platform for transitions among skyrmion- and hedgehog-lattice states. By neutron scattering, Lorentz transmission electron microscopy and high-field transport measurements, we observe three different topological spin textures with variation of the lattice constant controlled by Si/Ge substitution: two-dimensional skyrmion lattice in x = 0–0.25 and two distinct three-dimensional hedgehog lattices in x = 0.3–0.6 and x = 0.7–1. The emergence of various topological spin states in the chemical-pressure-controlled materials suggests a new route for direct manipulation of the spin-texture topology by facile mechanical methods.