bluuebunny/crossref_metadata_2025_split huggingface dataset:
Time series clustering and classification via frequency domain methods
Authors: Holan Scott H. , Ravishanker Nalini 
Published: July 2018

Technological innovations combined with various scientific inquiries have resulted in a broad array of classification and clustering applications. Many of these applications directly involve classifying or clustering time series and have leveraged recent methodological advances within the frequency (spectral) domain. This paper reviews methods for clustering/classifying time series in the frequency domain and, in particular, describes various methods for different types of time series ranging from linear and stationary to nonlinear and nonstationary. Our perspective is cast from the statistics/data science literature and does not migrate into the literature on signal processing. Finally, we also summarize various aspects related to implementation, thereby providing the necessary context for interested practitioners.This article is categorized under:Statistical Models > Time Series ModelsStatistical Learning and Exploratory Methods of the Data Sciences > Clustering and ClassificationData: Types and Structure > Time Series, Stochastic Processes, and Functional DataStatistical and Graphical Methods of Data Analysis > Bayesian Methods and Theory
Fear of missing out and sleep: Cognitive behavioural factors in adolescents' nighttime social media use
Authors: Scott Holly , Woods Heather Cleland 
Published: July 2018

ABSTRACTIntroductionSocial media use has been linked to poor adolescent sleep outcomes, but the mechanisms behind this association are not yet well understood. This study examines links between adolescents' social media habits, fear of missing out and sleep outcomes, using path analysis to evaluate a model of proposed underlying mechanisms.MethodsAdolescents aged 12–18 years (N = 101) completed questionnaire measures.ResultsNighttime social media use was associated with later bedtimes, increased pre‐sleep cognitive arousal, longer sleep onset latency and shorter sleep duration. Path analysis supported a model whereby fear of missing out predicted shorter sleep duration via two distinct mechanisms: (1) at a behavioural level, by driving late night social media use, which delays bedtimes; (2) at a cognitive level, by increasing pre‐sleep cognitive arousal, thus further delaying sleep onset.ConclusionsEfforts to develop and evaluate intervention strategies should therefore consider not only social media behaviours but also underlying cognitive factors, such as fear of missing out.
Female Office Workers With Moderate Neck Pain Have Increased Anterior Positioning of the Cervical Spine and Stiffness of Upper Trapezius Myofascial Tissue in Sitting Posture
Authors: Kocur Piotr , Wilski Maciej , Lewandowski Jacek , Łochyński Dawid 
Published: July 2018

AbstractBackgroundWork‐related neck disorders are among the most common dysfunctions in office workers. Understanding cervical myofascial mechanical characteristics that differentiate symptomatic from asymptomatic office workers is crucial for the understanding of musculoskeletal dysfunctions in workers with neck pain.ObjectiveTo assess the effect of moderate work‐related neck disorders on head posture and stiffness and perceived pain threshold of the upper trapezius (UT) and sternocleidomastoid (SCM) muscles.DesignCross‐sectional study.SettingWork environment.ParticipantsSixteen office workers with diagnosed moderate work‐related neck disorders and 16 asymptomatic office workers matched for sex, age, body mass index, and the nature and duration of their work.InterventionNot applicable.OutcomeThe primary outcome measure consisted of measurements of head posture using craniovertebral angle and myotonometric muscle stiffness (Newtons per meter) of the UT and SCM muscles. The secondary output variable was the perceived pain threshold algometry of the studied muscles.ResultsCompared with controls, subjects with work‐related neck pain had a significantly smaller craniovertebral angle (by 8.3%; Cohen d = 0.88, P = .02) and greater stiffness of the UT myofascial tissue (by 11.3%; Cohen d = 1.05, P = .006). No significant differences in perceived pain threshold of the myofascial tissue of the UT or SCM muscles were found between groups.ConclusionIn this study female office workers with neck pain had increased anterior positioning of the head and stiffness of the UT muscle in the sitting posture, which was not associated with changes in the pressure pain threshold of this muscle.Level of EvidenceIII
Hegel, Deleuze/Guattari and Political Immanence: The Sons of Rousseau
Authors: Hristov George 
Published: July 2018

AbstractIn the article I argue that Hegel and Deleuze/Guattari construct two distinct political paths toward immanence. Both of these paths have as their starting point Rousseau’s bourgeois. I show that both thinkers follow Rousseau in his attempt to construct political immanence and abandon the position of private man. However, in doing so they move in opposite directions. Hegel seeks to convert the bourgeois into the citizen, with the intention of reformulating the immanence of state-life presented in the The Social Contract by extending mutual recognition a distinct space in the form of civil society. In contrast Deleuze/Guattari move in the direction of becoming-animal along the lines of the Discourse on Inequality, by reformulating the relationship between life and society. At the same time, I argue that the overcoming of the problems that Hegel and Deleuze/Guattari identified in Rousseau introduces new ones and that the dangers inherent in the project of immanence cannot disappear.
The ethics of negative emissions
Authors: Lenzi Dominic 
Published: July 2018

Non-technical abstractLimiting dangerous climate change is widely believed to require negative emissions. This prospect has sparked concerns about whether negative emissions could be scaled up quickly enough, along with concerns about their likely ethical costs. Building upon scenario modelling, this paper examines ethical concerns with negative emissions via the comparison of three alternate climate futures. This paper shows that the severity of concerns depends upon implementation conditions, and especially the extent of deferred mitigation. Negative emissions can be a valuable means of limiting dangerous climate change, or an unjust gamble against the future.
Interhemispheric Survey of Polar Cap Aurora
Authors: Reidy J. A. , Fear R. C. , Whiter D. K. , Lanchester B. , Kavanagh A. J. , Milan S. E. , Carter J. A. , Paxton L. J. , Zhang Y. 
Published: July 2018

AbstractThis study investigates the interhemispheric nature of polar cap auroras via ultraviolet imaging, combined with particle data, to determine whether they occur on open or closed field lines. Data from the SSUSI (Special Sensor Ultraviolet Spectrographic Imager) instrument on board the DMSP (Defence Meteorological Satellite Program) spacecraft are examined. The DMSP spacecraft are in 90‐min orbits; hence, images of each hemisphere are separated by 45 min providing a good opportunity for interhemispheric study. 21 polar cap arc (PCA) events are recorded in December 2015 which have particle data from the SSJ/4 particle spectrometer associated with an arc in at least one hemisphere. Nine events are found to contain "arcs" consistent with a closed field line mechanism, that is, arcs associated with an ion signature present in both hemispheres. Six events contained arcs that were consistent with an "open field line" mechanism, that is, they were associated with electron‐only precipitation. Events containing arcs that were not consistent with either of these expectations are also explored, including an example of a "non‐conjugate" theta aurora and an interesting example of auroral morphology similar to a PCA which is associated with a geomagnetic storm. Seasonal effects are also investigated through a statistical analysis of PCAs over 4 months in 2015. It is found that PCAs are visible in the SSUSI data at least 20% of the time and that it is likely some are missed due to the spacecraft field of view and poor sensitivity in the summer hemisphere due to increased solar illumination.
Under What Conditions Can We Trust Retrieved Cloud Drop Concentrations in Broken Marine Stratocumulus?
Authors: Zhu Yannian , Rosenfeld Daniel , Li Zhanqing 
Published: July 2018

AbstractIn this study, we show how to obtain more reliable satellite‐retrieved cloud drop number concentrations (Nd) from Moderate Resolution Imaging Spectroradiometer (MODIS) standard cloud products. Nd is important as a fundamental cloud property that determines cloud albedo, precipitation‐forming processes, cloud longevity, and fractional cover, all of which determine cloud radiative effects. Nd is determined by cloud base aerosols and updrafts. Satellite retrievals of Nd for marine stratocumulus clouds are performed based on the assumption of a nearly adiabatic cloud column. The retrievals, however, are fraught with problems that cause large biases (e.g., the retrieved Nd for partially filled cloudy pixels are less than one third of the retrieved Nd for the convective cores) and limit the usefulness of Nd, especially in broken cloud fields. The Nd of the brightest 10% of cloudy pixels are selected because the brightest clouds are the convective cores that most closely follow adiabatic parcels, a key assumption of our retrieval. It is shown that this criterion is representative of pixels that are also fully surrounded by cloudy pixels (Nd agreement within 5%).
Observations and Modeling of Increased Nitric Oxide in the Antarctic Polar Middle Atmosphere Associated With Geomagnetic Storm‐Driven Energetic Electron Precipitation
Authors: Newnham D. A. , Clilverd M. A. , Rodger C. J. , Hendrickx K. , Megner L. , Kavanagh A. J. , Seppälä A. , Verronen P. T. , Andersson M. E. , Marsh D. R. , Kovács T. , Feng W. , Plane J. M. C. 
Published: July 2018

AbstractNitric oxide (NO) produced in the polar middle and upper atmosphere by energetic particle precipitation depletes ozone in the mesosphere and, following vertical transport in the winter polar vortex, in the stratosphere. Medium‐energy electron (MEE) ionization by 30–1,000 keV electrons during geomagnetic storms may have a significant role in mesospheric NO production. However, questions remain about the relative importance of direct NO production by MEE at altitudes ~60–90 km versus indirect NO originating from auroral ionization above 90 km. We investigate potential drivers of NO variability in the southern‐hemisphere mesosphere and lower thermosphere during 2013–2014. Contrasting geomagnetic activity occurred during the two austral winters, with more numerous moderate storms in the 2013 winter. Ground‐based millimeter‐wave observations of NO from Halley, Antarctica, are compared with measurements by the Solar Occultation For Ice Experiment (SOFIE) spaceborne spectrometer. NO partial columns over the altitude range 65–140 km from the two observational data sets show large day‐to‐day variability and significant disagreement, with Halley values on average 49% higher than the corresponding SOFIE data. SOFIE NO number densities, zonally averaged over geomagnetic latitudes −59° to −65°, are up to 3 × 108/cm3higher in the winter of 2013 compared to 2014. Comparisons with a new version of the Whole Atmosphere Community Climate Model, which includes detailedD‐region ion chemistry (WACCM‐SIC) and MEE ionization rates, show that the model underestimates NO in the winter lower mesosphere whereas thermospheric abundances are too high. This indicates the need to further improve and verify WACCM‐SIC with respect to MEE ionization, thermospheric NO chemistry, and vertical transport.
Reservoir Imaging Using Ambient Noise Correlation From a Dense Seismic Network
Authors: Lehujeur M. , Vergne J. , Schmittbuhl J. , Zigone D. , Le Chenadec A. ,   EstOF Team
Published: July 2018

AbstractIn September 2014, a dense temporary seismic network (EstOF) including 288 single‐component geophones was deployed during 1 month in the Outre‐Forêt region of the Upper Rhine Graben (France), where two deep geothermal projects (Soultz‐sous‐Forêts and Rittershoffen) are currently in operation. We apply ambient seismic noise correlation to estimate the empirical Green's function of the medium between the ~41,200 station pairs in the network. The noise correlation functions obtained are comparable to those from previous studies based on the sparse long‐term networks settled in the area mostly to monitor the induced seismic activity. However, the dense spatial coverage of the EstOF network improves our ability to identify the main phases of the Green's function. Both the fundamental mode and the first overtone of the Rayleigh waves are identified between most station pairs. P waves are also evidenced. We analyze the statistical distribution of the Rayleigh wave group velocity between station pairs as a function of the period (between 0.8 and 5 s), the station pair orientation, the distance over wavelength ratio and the signal‐to‐noise ratio. From these observations, we build a high‐resolution three‐dimensional S wave velocity model of the upper crust (down to 3 km deep) around the regional deep geothermal reservoirs. This model is consistent with local geological structures but also evidences nonlithological variations, particularly at depth in the basement. These variations are interpreted as large‐scale temperature anomalies related to deep hydrothermal circulation.
Sediment Dynamics in Wind Wave‐Dominated Shallow‐Water Environments
Authors: Nelson K. S. , Fringer O. B. 
Published: July 2018

AbstractSediment dynamics driven by waves and currents in shallow‐water estuarine environments impacts many physical and biological processes and is important to the estuary‐wide sediment budget. Observational restrictions have limited our ability to understand the physics governing sediment entrainment and mixing in these environments. To this end, we use direct numerical simulation to simulate sediment transport processes in shallow, combined wave‐ and current‐driven flows. Simulations are run with depth‐averaged currents ranging from 0 to 9 cm/s, while wave conditions are held constant with a bottom orbital velocity and period of 10 cm/s and 3 s, respectively. Our results indicated that for wave‐dominated conditions, waves reduce vertical momentum fluxes and the associated bottom drag, thereby accelerating mean currents. Conversely, currents do not significantly affect the wave velocity field. However, they increase the bed shear stress and change the timing and duration of sediment entrainment throughout the wave cycle. Counterintuitively, these effects lead to lower suspended sediment concentrations near the bed for a portion of the wave cycle. By analyzing sediment fluxes, waves are shown to drive near‐bed sediment dynamics while currents control vertical mixing above the buffer layer, where downward settling is predominantly balanced by the current‐generated vertical turbulent sediment flux. In the absence of currents, sediment concentrations are negligible above the wave boundary layer because mixing is weak. We show that the time‐ and phase‐averaged sediment concentration profiles for wave and current conditions resemble the theoretical Rouse profile derived for equilibrium conditions in statistically steady, unidirectional turbulent channel flow.
Comparison of Daytime Low‐Level Cloud Properties Derived From GOES and ARM SGP Measurements
Authors: McHardy Theodore M. , Dong Xiquan , Xi Baike , Thieman Mandana M. , Minnis Patrick , Palikonda Rabindra 
Published: July 2018

AbstractLarge‐scale satellite data are critical for both verifying and improving general circulation model parameterizations of clouds and radiation for climate prediction. For reliable application of satellite data sets in cloud processes and climate models, it is important to have a reasonable estimate of the errors in the derived cloud properties. The daytime single‐layered low‐level cloud properties retrieved by the Geostationary Operational Environmental Satellite system (GOES) are compared with ground‐based observations and retrievals over the Department of Energy Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Central Facility from June 1998 to December 2006. The GOES retrievals are made via the Visible‐Infrared Solar‐infrared Split‐window Technique. They are spatially averaged within a 0.15° × 0.15° box centered on the ARM SGP site, and the ARM surface observations are temporally averaged ±15 min around the GOES scans to produce collocated pairs. Comparisons are made for monthly means, diurnal means, and one‐to‐one GOES and ARM collocated pairs. GOES Teff is highly correlated with ARM Ttop cloud temperature, having an R2 value of 0.75, though GOES exhibits a cold bias. GOES‐retrieved τ and liquid water path have very good agreement with ARM retrievals with R2s of 0.45 and 0.47, while re (GOES), on average, is about 2 μm greater than ARM re. An examination of solar and viewing geometry has shown that GOES‐retrieved mean re and τ values are impacted by solar zenith angle and especially scattering angle, which is not unexpected and needs to be accounted for by users.
Merge and separation of NuA4 and SWR1 complexes control cell fate plasticity in Candida albicans
Authors: Wang Xiongjun , Zhu Wencheng , Chang Peng , Wu Hongyu , Liu Haoping , Chen Jiangye 
Published: July 2018

AbstractPhenotypic plasticity is common in development. Candida albicans, a polymorphic fungal pathogen of humans, possesses the unique ability to achieve rapid and reversible cell fate between unicellular form (yeast) and multicellular form (hypha) in response to environmental cues. The NuA4 histone acetyltransferase activity and Hda1 histone deacetylase activity have been reported to be required for hyphal initiation and maintenance. However, how Hda1 and NuA4 regulate hyphal elongation is not clear. NuA4 histone acetyltransferase and SWR1 chromatin remodeling complexes are conserved from yeast to human, which may have merged together to form a larger TIP60 complex since the origin of metazoan. In this study, we show a dynamic merge and separation of NuA4 and SWR1 complexes in C. albicans. NuA4 and SWR1 merge together in yeast state and separate into two distinct complexes in hyphal state. We demonstrate that acetylation of Eaf1 K173 controls the interaction between the two complexes. The YEATS domain of Yaf9 in C. albicans can recognize an acetyl-lysine of the Eaf1 and mediate the Yaf9-Eaf1 interaction. The reversible acetylation and deacetylation of Eaf1 by Esa1 and Hda1 control the merge and separation of NuA4 and SWR1, and this regulation is triggered by Brg1 recruitment of Hda1 to chromatin in response nutritional signals that sustain hyphal elongation. We have also observed an orchestrated promoter association of Esa1, Hda1, Swr1, and H2A.Z during the reversible yeast–hyphae transitions. This is the first discovery of a regulated merge of the NuA4 and SWR1 complexes that controls cell fate determination and this regulation may be conserved in polymorphic fungi.
FABP4 as a key determinant of metastatic potential of ovarian cancer
Authors: Gharpure Kshipra M. , Pradeep Sunila , Sans Marta , Rupaimoole Rajesha , Ivan Cristina , Wu Sherry Y. , Bayraktar Emine , Nagaraja Archana S. , Mangala Lingegowda S. , Zhang Xinna , Haemmerle Monika , Hu Wei , Rodriguez-Aguayo Cristian , McGuire Michael , Mak Celia Sze Ling , Chen Xiuhui , Tran Michelle A. , Villar-Prados Alejandro , Pena Guillermo Armaiz , Kondetimmanahalli Ragini , Nini Ryan , Koppula Pranavi , Ram Prahlad , Liu Jinsong , Lopez-Berestein Gabriel , Baggerly Keith , S. Eberlin Livia , Sood Anil K. 
Published: July 2018

AbstractThe standard treatment for high-grade serous ovarian cancer is primary debulking surgery followed by chemotherapy. The extent of metastasis and invasive potential of lesions can influence the outcome of these primary surgeries. Here, we explored the underlying mechanisms that could increase metastatic potential in ovarian cancer. We discovered that FABP4 (fatty acid binding protein) can substantially increase the metastatic potential of cancer cells. We also found that miR-409-3p regulates FABP4 in ovarian cancer cells and that hypoxia decreases miR-409-3p levels. Treatment with DOPC nanoliposomes containing either miR-409-3p mimic or FABP4 siRNA inhibited tumor progression in mouse models. With RPPA and metabolite arrays, we found that FABP4 regulates pathways associated with metastasis and affects metabolic pathways in ovarian cancer cells. Collectively, these findings demonstrate that FABP4 is functionally responsible for aggressive patterns of disease that likely contribute to poor prognosis in ovarian cancer.
Non-hysteretic first-order phase transition with large latent heat and giant low-field magnetocaloric effect
Authors: Guillou F. , Pathak A. K. , Paudyal D. , Mudryk Y. , Wilhelm F. , Rogalev A. , Pecharsky V. K. 
Published: July 2018

AbstractFirst-order magnetic transitions (FOMTs) with a large discontinuity in magnetization are highly sought in the development of advanced functional magnetic materials. Isosymmetric magnetoelastic FOMTs that do not perturb crystal symmetry are especially rare, and only a handful of material families, almost exclusively transition metal-based, are known to exhibit them. Yet, here we report a surprising isosymmetric FOMT in a rare-earth intermetallic, Eu2In. What makes this transition in Eu2In even more remarkable is that it is associated with a large latent heat and an exceptionally high magnetocaloric effect in low magnetic fields, but with tiny lattice discontinuities and negligible hysteresis. An active role of the Eu-5d and In-4p states and a rather unique electronic structure borne by In to Eu charge transfer, altogether result in an unusual exchange mechanism that both sets the transition in motion and unveils an approach toward developing specific magnetic functionalities ad libitum.
Exploring the performance of nanostructured reagents with organic-group-defined morphology in cross-coupling reaction
Authors: Kashin Alexey S. , Degtyareva Evgeniya S. , Eremin Dmitry B. , Ananikov Valentine P. 
Published: July 2018

AbstractThe great impact of the nanoscale organization of reactive species on their performance in chemical transformations creates the possibility of fine-tuning of reaction parameters by modulating the nano-level properties. This methodology is extensively applied for the catalysts development whereas nanostructured reactants represent the practically unexplored area. Here we report the palladium- and copper-catalyzed cross-coupling reaction involving nano-structured nickel thiolate particles as reagents. On the basis of experimental findings we propose the cooperative effect of nano-level and molecular-level properties on their reactivity. The high degree of ordering, small particles size, and electron donating properties of the substituents favor the product formation. Reactant particles evolution in the reaction is visualized directly by dynamic liquid-phase electron microscopy including recording of video movies. Mechanism of the reaction in liquid phase is established using on-line mass spectrometry measurements. Together the findings provide new opportunities for organic chemical transformations design and for mechanistic studies.