bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative appraisal of the Amyloid Imaging Taskforce appropriate use criteria for amyloid‐PET
Authors: Altomare Daniele , Ferrari Clarissa , Festari Cristina , Guerra Ugo Paolo , Muscio Cristina , Padovani Alessandro , Frisoni Giovanni B. , Boccardi Marina ,   for the Incremental Diagnostic Value of Amyloid PET With [F]‐Florbetapir (INDIA‐FBP) Working Group
Published: April 2018

AbstractIntroductionWe test the hypothesis that amyloid–positron emission tomography prescriptions, considered appropriate based on the Amyloid Imaging Taskforce (AIT) criteria, lead to greater clinical utility than AIT‐inappropriate prescriptions.MethodsWe compared the clinical utility between patients who underwent amyloid–positron emission tomography appropriately or inappropriately and among the subgroups of patients defined by the AIT criteria. Finally, we performed logistic regressions to identify variables associated with clinical utility.ResultsWe identified 171 AIT‐appropriate and 67 AIT‐inappropriate patients. AIT‐appropriate and AIT‐inappropriate cases did not differ in any outcomes of clinical utility (P > .05). Subgroup analysis denoted both expected and unexpected results. The logistic regressions outlined the primary role of clinical picture and clinical or neuropsychological profile in identifying patients benefitting from amyloid–positron emission tomography.DiscussionContrary to our hypothesis, also AIT‐inappropriate prescriptions were associated with clinical utility. Clinical or neuropsychological variables, not taken into account by the AIT criteria, may help further refine criteria for appropriateness.
Evidence of demyelination in mild cognitive impairment and dementia using a direct and specific magnetic resonance imaging measure of myelin content
Authors: Bouhrara Mustapha , Reiter David A. , Bergeron Christopher M. , Zukley Linda M. , Ferrucci Luigi , Resnick Susan M. , Spencer Richard G. 
Published: April 2018

AbstractIntroductionWe investigated brain demyelination in aging, mild cognitive impairment (MCI), and dementia using a direct magnetic resonance imaging marker of myelin.MethodsBrains of young and old controls, and old subjects with MCI, Alzheimer's disease, or vascular dementia were scanned using our recently developed myelin water fraction (MWF) mapping technique, which provides greatly improved accuracy over previous comparable methods. Maps of MWF, a direct and specific myelin measure, and relaxation times and magnetization transfer ratio, indirect and nonspecific measures, were constructed.ResultsMCI subjects showed decreased MWF compared with old controls. Demyelination was greater in Alzheimer's disease or vascular dementia. As expected, decreased MWF was accompanied by decreased magnetization transfer ratio and increased relaxation times. The young subjects showed greater myelin content than the old subjects.DiscussionWe believe this to be the first demonstration of myelin loss in MCI, Alzheimer's disease, and vascular dementia using a method that provides a quantitative magnetic resonance imaging–based measure of myelin. Our findings add to the emerging evidence that myelination may represent an important biomarker for the pathology of MCI and dementia. This study supports the investigation of the role of myelination in MCI and dementia through use of this quantitative magnetic resonance imaging approach in clinical studies of disease progression, and relationship of functional status to myelination status. Furthermore, mapping MWF may permit myelin to serve as a therapeutic target in clinical trials.
Assessment of Behavioral Health Concerns in the Community Affected by the Flint Water Crisis — Michigan (USA) 2016
Authors: Fortenberry Gamola Z. , Reynolds Patricia , Burrer Sherry L. , Johnson-Lawrence Vicki , Wang Alice , Schnall Amy , Pullins Price , Kieszak Stephanie , Bayleyegn Tesfaye , Wolkin Amy 
Published: April 2018

AbstractObjectivesThe Flint Community Resilience Group (Flint, Michigan USA) and the Centers for Disease Control and Prevention (CDC; Atlanta, Georgia USA) assessed behavioral health concerns among community members to determine the impact of lead contamination of the Flint, Michigan water supply.MethodsA Community Assessment for Public Health Emergency Response (CASPER) was conducted from May 17 through May 19, 2016 using a multi-stage cluster sampling design to select households and individuals to interview.ResultsOne-half of households felt overlooked by decision makers. The majority of households self-reported that at least one member experienced more behavioral health concerns than usual. The prevalence of negative quality of life indicators and financial concerns in Flint was higher than previously reported in the Michigan 2012 and 2014 Behavioral Risk Factor Surveillance System (BRFSS) survey.ConclusionsThe following can be considered to guide recovery efforts in Flint: identifying additional resources for behavioral health interventions and conducting follow-up behavioral health assessments to evaluate changes in behavioral health concerns over time; considering the impact of household economic factors when implementing behavioral health interventions; and ensuring community involvement and engagement in recovery efforts to ease community stress and anxiety.FortenberryGZ, ReynoldsP, BurrerSL, Johnson-LawrenceV, WangA, SchnallA, PullinsP, KieszakS, BayleyegnT, WolkinA. Assessment of behavioral health concerns in the community affected by the Flint water crisis — Michigan (USA) 2016. Prehosp Disaster Med. 2018;33(3):256–265.
THE SEMANTICS OF VALUE-RANGE NAMES AND FREGE’S PROOF OF REFERENTIALITY
Authors: SCHIRN MATTHIAS 
Published: April 2018

AbstractIn this article, I try to shed some new light onGrundgesetze§10, §29–§31 with special emphasis on Frege’s criteria and proof of referentiality and his treatment of the semantics of canonical value-range names. I begin by arguing against the claim, recently defended by several Frege scholars, that the first-order domain inGrundgesetzeis restricted to value-ranges (including the truth-values), but conclude that there is an irresolvable tension in Frege’s view. The tension has a direct impact on the semantics of the concept-script, not least on the semantics of value-range names. I further argue that despite first appearances truth-value names (sentences) play a distinguished role as semantic “target names” for “test names” in the criteria of referentiality (§29) and do not figure themselves as “test names” regarding referentiality. Accordingly, I show in detail that Frege’s attempt to demonstrate that by virtue of his stipulations “regular” value-range names have indeed been endowed with a unique reference, can plausibly be regarded as a direct application of the context principle. In a subsequent section, I turn to some special issues involved in §10. §10 is closely intertwined with §31 and in my and Richard Heck’s view would have been better positioned between §30 and §31. In a first step, I discuss the piecemeal strategy which Frege applies when he attempts to bestow a unique reference on value-range names in §3, §10–§12. In a second step, I critically analyze his tentative, but predictably unsuccessful proposal (in a long footnote to §10) to identify all objects whatsoever, including those already clad in the garb of value-ranges, with their unit classes. In conclusion, I present two arguments for my claim that Frege’s identification of the True and the False with their unit classes in §10 is illicit even if both the permutation argument and the identifiability thesis that he states in §10 are regarded as formally sound. The first argument is set out from the point of view of the syntax of his formal language. It suggests though that a reorganization of the exposition of the concept-script would have solved at least one of the problems to which the twin stipulations in §10 give rise. The second argument rests on semantic considerations. If it is sound, it may call into question, if not undermine the legitimacy of the twin stipulations.
Direct EUV/X‐Ray Modulation of the Ionosphere During the August 2017 Total Solar Eclipse
Authors: Mrak Sebastijan , Semeter Joshua , Drob Douglas , Huba J. D. 
Published: April 2018

AbstractThe great American total solar eclipse of 21 August 2017 offered a fortuitous opportunity to study the response of the atmosphere and ionosphere using a myriad of ground instruments. We have used the network of U.S. Global Positioning System receivers to examine perturbations in maps of ionospheric total electron content (TEC). Coherent large‐scale variations in TEC have been interpreted by others as gravity wave‐induced traveling ionospheric disturbances. However, the solar disk had two active regions at that time, one near the center of the disk and one at the edge, which resulted in an irregular illumination pattern in the extreme ultraviolet (EUV)/X‐ray bands. Using detailed EUV occultation maps calculated from the National Aeronautics and Space Administration Solar Dynamics Observatory Atmospheric Imaging Assembly images, we show excellent agreement between TEC perturbations and computed gradients in EUV illumination. The results strongly suggest that prominent large‐scale TEC disturbances were consequences of direct EUV modulation, rather than gravity wave‐induced traveling ionospheric disturbances.
Subsidence of Ionospheric Flows Triggered by Magnetotail Magnetic Reconnection During Transpolar Arc Brightening
Authors: Nowada Motoharu , Fear Robert C. , Grocott Adrian , Shi Quan‐Qi , Yang Jun , Zong Qiu‐Gang , Wei Yong , Fu Sui‐Yan , Pu Zu‐Yin , Mailyan Bagrat , Zhang Hui 
Published: April 2018

AbstractA transpolar arc (TPA), which extended from postmidnight to prenoon, was seen on 16 September 2001 in the Northern Hemisphere under northward interplanetary magnetic field (IMF)‐Bz and weakly dawnward IMF‐By conditions. Super Dual Auroral Radar Network detected significant westward plasma flows just equatorward of the poleward edge of the midnight sector auroral oval. These plasma flows were confined to closed field lines and are identified as the ionospheric plasma flow signature of tail reconnection during IMF northward nonsubstorm intervals (TRINNIs). These TRINNI flows persisted for 53 min from prior to the TPA appearance to the cessation of TPA growth. They are usually observed before (and during) intervals when TPAs are present, but in this case, subsided after the TPA was completely connected to the dayside. Additional slower flows across the open/closed polar cap boundary were seen at the TPA onset time in the same magnetic local time sector as the nightside end of the TPA. These ionospheric flows suggest that magnetotail reconnection significantly contributed to the TPA formation, as proposed by Milan et al. (, https://doi.org/10.1029/2004JA010835). We propose a possible scenario for an absence of the TRINNI flows during the TPA brightening by considering the relation between the extent of the magnetotail reconnection line mapped onto nightside auroral oval and the TPA width; TRINNI flows would subside when the extent of X‐line is comparable to the TPA width. Therefore, our results suggest that the fate (absence or presence) of TRINNI flows on closed field lines during the TPA formation would be closely related with magnetotail reconnection extent.
Buoyancy Waves in Earth's Magnetosphere: Calculations for a 2‐D Wedge Magnetosphere
Authors: Wolf R. A. , Toffoletto F. R. , Schutza A. M. , Yang J. 
Published: April 2018

AbstractTo improve theoretical understanding of the braking oscillations observed in Earth's inner plasma sheet, we have derived a theoretical model that describes k∥ = 0 magnetohydrodynamic waves in an idealized magnetospheric configuration that consists of a 2‐D wedge with circular‐arc field lines. The low‐frequency, short‐perpendicular‐wavelength mode obeys a differential equation that is often used to describe buoyancy oscillations in a neutral atmosphere, so we call those waves “buoyancy waves,” though the magnetospheric buoyancy force results from magnetic tension rather than gravity. Propagation of the wave is governed mainly by a position‐dependent frequency ωb, the “buoyancy frequency,” which is a fundamental property of the magnetosphere. The waves propagate if ωb > ω but otherwise evanesce. In the wedge magnetosphere, ωb turns out to be exactly the fundamental oscillation frequency for poloidal oscillations of a thin magnetic filament, and we assume that the same is true for the real magnetosphere. Observable properties of buoyancy oscillations are discussed, but propagation characteristics vary considerably with the state of the magnetosphere. For a given event, the buoyancy frequency and propagation characteristics can be determined from pressure and density profiles and a magnetic field model, and these characteristics have been worked out for one typical configuration. A localized disturbance that initially resembles a dipolarizing flux bundle spreads east‐west and also penetrates into the plasmasphere to some extent. The calculated amplitude near the center of the original wave packet decays in a few oscillation periods, even though our calculation includes no dissipation.
Laboratory Investigation Into the Formation and Dissociation Process of Gas Hydrate by Low‐Field NMR Technique
Authors: Ge Xinmin , Liu Jianyu , Fan Yiren , Xing Donghui , Deng Shaogui , Cai Jianchao 
Published: April 2018

AbstractWe monitored the gas hydrate through low‐field nuclear magnetic resonance measurement. An observed decrease of the relaxation time (T2) intensity corresponds to the formation process, whereas an increase of the intensity corresponds to the dissociation process. The right domain of the spectrum with T2 larger than 10 ms disappears gradually with the formation time, whereas the left domain with T2 smaller than 1 ms remains invariant, indicating the gas hydrate forms preferentially in larger pores. In addition, the right domain increases rapidly with the dissociation time, revealing that the gas hydrate preferentially decomposes in large pores. The spectrum distributions move toward the fast relaxation domain with the growth of gas hydrate, because the generated gas hydrate occupies the large pore and accelerate the relaxation rate. There is no obvious relationship between the gas hydrate saturation and the porosity, whereas the volume and preliminary dissociation ratio are strongly correlated with the porosity.
Numerical Modeling of Historical Storm Tides and Waves and Their Interactions Along the U.S. East and Gulf Coasts
Authors: Marsooli Reza , Lin Ning 
Published: April 2018

AbstractWe apply a coupled circulation‐wave model to simulate extreme sea levels induced by tropical cyclones at the basin scale. We quantify storm tides, surges, waves, and their interactions for historical tropical cyclones (1988–2015) in the western North Atlantic Ocean. Comparisons between model results and field observations along the U.S. East and Gulf Coasts indicate that the overall performance of the model is satisfactory, with a root‐mean‐square error, bias, and Willmott skill of, respectively, 0.31, −0.04 m, and 0.9 for storm tides and 1.94 m, −0.22 m, and 0.87 for significant wave heights. Model results show that the highest surge levels were generated in Western Long Island Sound and NY/NJ Harbor, along the coasts of the Carolinas and Southwest Florida, near the Mississippi River delta, and along the coasts of Louisiana and East Texas. We find that the nonlinear tide‐surge interaction is often significant, but its contribution to peak storm tides induced by the most extreme events (i.e., storms that caused storm tides larger than 2 m) was moderate (−12% to 5%). We find that the maximum wave setup was relatively large (tens of cm) in most coastal regions, but it did not necessarily coincide with the peak storm tide. The contribution of wave setup to peak storm tides induced by the most extreme events was less than 17%. Finally, we show that while some offshore storms did not affect the coastal areas with high storm surges or strong winds, they generated the largest historical wave setup at the coast.
Investigating Satellite Precipitation Uncertainty Over Complex Terrain
Authors: Bartsotas N. S. , Anagnostou E. N. , Nikolopoulos E. I. , Kallos G. 
Published: April 2018

AbstractThe estimation of heavy precipitation events is a particularly difficult task, especially over high mountainous terrain typically associated with scant availability of in situ observations. Therefore, quantification of precipitation variability in such data‐limited regions relies on remote sensing estimates, due to their global coverage and near real‐time availability. However, strong underestimation of precipitation associated with low‐level orographic enhancement often limits the quantitative use of these data in applications. This study utilizes state‐of‐the‐art numerical weather prediction simulations, toward the reduction of quantitative errors in satellite precipitation estimates and an insight on the nature of detection limitations. Satellite precipitation products based on different retrieval algorithms (Climate Prediction Center morphing method, Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks‐Cloud Classification System, and Global Satellite Mapping of Precipitation) are evaluated for their performance in a number of storm events over mountainous areas with distinct storm characteristics: Upper Blue Nile in Ethiopia and Alto Adige in NE Italy. High‐resolution (1 and 2 km) simulations from the Regional Atmospheric Modeling System/Integrated Community Limited Area Modeling System are used to derive adjustments to the magnitude of satellite estimates. Finally, a microphysical investigation is presented for occurrences of erroneous precipitation detection from the satellite instruments. Statistical indexes showcase improvement in numerical weather prediction‐adjusted satellite products and microphysical commodities among cases of no detection are discussed.
Analysis of Rock Abundance on Lunar Surface From Orbital and Descent Images Using Automatic Rock Detection
Authors: Li Yuan , Wu Bo 
Published: April 2018

AbstractInformation on the distribution and abundance of rocks on the lunar surface is essential for understanding the characteristics of lunar regolith and for selecting suitable landing sites for lunar exploration missions. This paper first presents a novel automatic rock detection approach based on the gradient differences in illumination direction. Multiple‐source images covering different regions of the lunar surface are then used for rock detection and rock abundance analysis, including the Chang'E‐3 descent images (0.02–0.17 m/pixel) around the landing area, the Lunar Reconnaissance Orbiter (LRO) Narrow Angle Camera images (0.3–1.1 m/pixel) at the landing sites of the Chang'E‐3, Luna 17, and Luna 23, and the LRO Narrow Angle Camera image mosaic (1.5 m/pixel) in the Oceanus Procellarum area. A rock abundance model using an exponential form is derived from the results of the abovementioned analysis to describe the overall cumulative fractional area of rocks versus their diameters. The rock detection results and the derived rock abundance estimated by the proposed model are compared with the ground measurements obtained using the rover images of the Chang'E‐3 landing site and the LRO Diviner Radiometer‐derived rock abundance. A comparison analysis indicates that the derived rock abundance model can feasibly represent the rock abundance in various situations on local and large scales. In general, a remarkable consistency is observed between our results and the results obtained using the ground measurements at the Chang'E‐3 landing site and the orbit measurements from the Diviner radiometer, while our rock detection results and rock abundance model exhibit better performance in presenting detailed information in local areas. Further analyses on rock abundance and the crater morphology and other crater characteristics in the Oceanus Procellarum area indicate that it is feasible to use rock abundance information to estimate the surface maturity.
Atmospheric Signature of the Agulhas Current
Authors: Nkwinkwa Njouodo Arielle Stela , Koseki Shunya , Keenlyside Noel , Rouault Mathieu 
Published: April 2018

AbstractWestern boundary currents play an important role in the climate system by transporting heat poleward and releasing it to the atmosphere. While their influence on extratropical storms and oceanic rainfall is becoming appreciated, their coastal influence is less known. Using satellite and climate reanalysis data sets and a regional atmospheric model, we show that the Agulhas Current is a driver of the observed band of rainfall along the southeastern African coast and above the Agulhas Current. The Agulhas current's warm core is associated with sharp gradients in sea surface temperature and sea level pressure, a convergence of low‐level winds, and a co‐located band of precipitation. Correlations among wind convergence, sea level pressure, and sea surface temperature indicate that these features show high degree of similarity to those in the Gulf Stream region. Model experiments further indicate that the Agulhas Current mostly impacts convective rainfall.
The Twisted Configuration of the Martian Magnetotail: MAVEN Observations
Authors: DiBraccio Gina A. , Luhmann Janet G. , Curry Shannon M. , Espley Jared R. , Xu Shaosui , Mitchell David L. , Ma Yingjuan , Dong Chuanfei , Gruesbeck Jacob R. , Connerney John E. P. , Harada Yuki , Ruhunusiri Suranga , Halekas Jasper S. , Soobiah Yasir , Hara Takuya , Brain David A. , Jakosky Bruce M. 
Published: April 2018

AbstractMeasurements provided by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft are analyzed to investigate the Martian magnetotail configuration as a function of interplanetary magnetic field (IMF) BY. We find that the magnetotail lobes exhibit a ~45° twist, either clockwise or counterclockwise from the ecliptic plane, up to a few Mars radii downstream. Moreover, the associated cross‐tail current sheet is rotated away from the expected location for a Venus‐like induced magnetotail based on nominal IMF draping. Data‐model comparisons using magnetohydrodynamic simulations are in good agreement with the observed tail twist. Model field line tracings indicate that a majority of the twisted tail lobes are composed of open field lines, surrounded by draped IMF. We infer that dayside magnetic reconnection between the crustal fields and draped IMF creates these open fields and may be responsible for the twisted tail configuration, similar to what is observed at Earth.
Mineral Dust Instantaneous Radiative Forcing in the Arctic
Authors: Kylling A. , Groot Zwaaftink C. D. , Stohl A. 
Published: April 2018

AbstractMineral dust sources at high and low latitudes contribute to atmospheric dust loads and dust deposition in the Arctic. With dust load estimates from Groot Zwaaftink et al. (, https://doi.org/10.1002/2016JD025482), we quantify the mineral dust instantaneous radiative forcing (IRF) in the Arctic for the year 2012. The annual‐mean top of the atmosphere IRF is 0.225 W/m2, with the largest contributions from dust transported from Asia south of 60°N and Africa. High‐latitude (>60°N) dust sources contribute about 39% to top of the atmosphere IRF and have a larger impact (1 to 2 orders of magnitude) on IRF per emitted kilogram of dust than low‐latitude sources. Mineral dust deposited on snow accounts for nearly all of the bottom of the atmosphere IRF of 0.135 W/m2. More than half of the bottom of the atmosphere IRF is caused by dust from high‐latitude sources, indicating substantial regional climate impacts rarely accounted for in current climate models.