bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reflection imaging of the Moon's interior using deep‐moonquake seismic interferometry
Authors: Nishitsuji Yohei , Rowe C. A. , Wapenaar Kees , Draganov Deyan 
Published: April 2016

AbstractThe internal structure of the Moon has been investigated over many years using a variety of seismic methods, such as travel time analysis, receiver functions, and tomography. Here we propose to apply body‐wave seismic interferometry to deep moonquakes in order to retrieve zero‐offset reflection responses (and thus images) beneath the Apollo stations on the nearside of the Moon from virtual sources colocated with the stations. This method is called deep‐moonquake seismic interferometry (DMSI). Our results show a laterally coherent acoustic boundary around 50 km depth beneath all four Apollo stations. We interpret this boundary as the lunar seismic Moho. This depth agrees with Japan Aerospace Exploration Agency's (JAXA) SELenological and Engineering Explorer (SELENE) result and previous travel time analysis at the Apollo 12/14 sites. The deeper part of the image we obtain from DMSI shows laterally incoherent structures. Such lateral inhomogeneity we interpret as representing a zone characterized by strong scattering and constant apparent seismic velocity at our resolution scale (0.2–2.0 Hz).
Cyclic steps on ice
Authors: Yokokawa M. , Izumi N. , Naito K. , Parker G. , Yamada T. , Greve R. 
Published: April 2016

AbstractBoundary waves often form at the interface between ice and fluid flowing adjacent to it, such as ripples under river ice covers, and steps on the bed of supraglacial meltwater channels. They may also be formed by wind, such as the megadunes on the Antarctic ice sheet. Spiral troughs on the polar ice caps of Mars have been interpreted to be cyclic steps formed by katabatic wind blowing over ice. Cyclic steps are relatives of upstream‐migrating antidunes. Cyclic step formation on ice is not only a mechanical but also a thermodynamic process. There have been very few studies on the formation of either cyclic steps or upstream‐migrating antidunes on ice. In this study, we performed flume experiments to reproduce cyclic steps on ice by flowing water, and found that trains of steps form when the Froude number is larger than unity. The features of those steps allow them to be identified as ice‐bed analogs of cyclic steps in alluvial and bedrock rivers. We performed a linear stability analysis and obtained a physical explanation of the formation of upstream‐migrating antidunes, i.e., precursors of cyclic steps. We compared the results of experiments with the predictions of the analysis and found the observed steps fall in the range where the analysis predicts interfacial instability. We also found that short antidune‐like undulations formed as a precursor to the appearance of well‐defined steps. This fact suggests that such antidune‐like undulations correspond to the instability predicted by the analysis and are precursors of cyclic steps.
Alongshore sediment bypassing as a control on river mouth morphodynamics
Authors: Nienhuis Jaap H. , Ashton Andrew D. , Nardin William , Fagherazzi Sergio , Giosan Liviu 
Published: April 2016

AbstractRiver mouths, shoreline locations where fluvial and coastal sediments are partitioned via erosion, trapping, and redistribution, are responsible for the ultimate sedimentary architecture of deltas and, because of their dynamic nature, also pose great management and engineering challenges. To investigate the interaction between fluvial and littoral processes at wave‐dominated river mouths, we modeled their morphologic evolution using the coupled hydrodynamic and morphodynamic model Delft3D‐SWAN. Model experiments replicate alongshore migration of river mouths, river mouth spit development, and eventual spit breaching, suggesting that these are emergent phenomena that can develop even under constant fluvial and wave conditions. Furthermore, we find that sediment bypassing of a river mouth develops though feedbacks between waves and river mouth morphology, resulting in either continuous bypassing pathways or episodic bar bypassing pathways. Model results demonstrate that waves refracting into the river mouth bar create a zone of low alongshore sediment transport updrift of the river mouth, which reduces sediment bypassing. Sediment bypassing, in turn, controls the river mouth migration rate and the size of the river mouth spit. As a result, an intermediate amount of river discharge maximizes river mouth migration. The fraction of alongshore sediment bypassing can be predicted from the balance between the jet and the wave momentum flux. Quantitative comparisons show a match between our modeled predictions of river mouth bypassing and migration rates observed in natural settings.
Mars surface context cameras past, present, and future
Authors: Gunn M. D. , Cousins C. R. 
Published: April 2016

AbstractMars has been the focus of robotic space exploration since the 1960s, in which time there have been over 40 missions, some successful, some not. Camera systems have been a core component of all instrument payloads sent to the Martian surface, harnessing some combination of monochrome, color, multispectral, and stereo imagery. Together, these data sets provide the geological context to a mission, which over the decades has included the characterization and spatial mapping of geological units and associated stratigraphy, charting active surface processes such as dust devils and water ice sublimation, and imaging the robotic manipulation of samples via scoops (Viking), drills (Mars Science Laboratory (MSL) Curiosity), and grinders (Mars Exploration Rovers). Through the decades, science context imaging has remained an integral part of increasingly advanced analytical payloads, with continual advances in spatial and spectral resolution, radiometric and geometric calibration, and image analysis techniques. Mars context camera design has encompassed major technological shifts, from single photomultiplier tube detectors to megapixel charged‐couple devices, and from multichannel to Bayer filter color imaging. Here we review the technological capability and evolution of science context imaging instrumentation resulting from successful surface missions to Mars, and those currently in development for planned future missions.
Rapid variability of Antarctic Bottom Water transport into the Pacific Ocean inferred from GRACE
Authors: Mazloff Matthew R. , Boening Carmen 
Published: April 2016

AbstractAir‐ice‐ocean interactions in the Antarctic lead to formation of the densest waters on Earth. These waters convect and spread to fill the global abyssal oceans. The heat and carbon storage capacity of these water masses, combined with their abyssal residence times that often exceed centuries, makes this circulation pathway the most efficient sequestering mechanism on Earth. Yet monitoring this pathway has proven challenging due to the nature of the formation processes and the depth of the circulation. The Gravity Recovery and Climate Experiment (GRACE) gravity mission is providing a time series of ocean mass redistribution and offers a transformative view of the abyssal circulation. Here we use the GRACE measurements to infer, for the first time, a 2003–2014 time series of Antarctic Bottom Water export into the South Pacific. We find this export highly variable, with a standard deviation of 1.87 sverdrup (Sv) and a decorrelation timescale of less than 1 month. A significant trend is undetectable.
Modeling magnetospheric energetic particle escape across Earth's magnetopause as observed by the MMS mission
Authors: Mauk Barry H. , Cohen Ian J. , Westlake Joseph H. , Anderson Brian J. 
Published: April 2016

AbstractA longstanding puzzle is that the escape of magnetospheric energetic particles (greater than tens of keV) across Earth's magnetopause into the magnetosheath is common irrespective of conditions thought to engender magnetic reconnection and boundary normal magnetic fields. Multiple causes for escape have been invoked, including interactions with strong gradients, wave scattering, boundary dynamics, and boundary normal fields. Here we tackle only part of the problem by developing a relatively simple kinetic model including critical features not utilized in previous models. We find that particles can often completely escape without invoking waves or unmodeled magnetosheath structures for both northwardly and southwardly magnetosheath fields. Because multiple means of escape are found to be available, the particles are hard to completely contain, consistent with observations. The model also predicts specific pitch angle evolution signatures that uniquely identify boundary normal field‐enabled escape, now reported in a companion paper as observed by the Magnetospheric Multiscale (MMS) mission.
Will the Tibetan Plateau warming depend on elevation in the future?
Authors: Guo Donglin , Yu Entao , Wang Huijun 
Published: April 2016

AbstractElevation‐dependent warming, greater warming at higher elevations, tends to accelerate the ablation of solid water reserves on the Tibetan Plateau and is thus expected to affect the sustainable water supply of the plateau. In the context of a global climate that is predicted to continue to warm, whether elevation‐dependent warming exists on the Tibetan Plateau in the future and, if so, what its characteristics and mechanisms are, are important issues that have not yet been fully assessed. Using six sets of high‐resolution outputs from dynamical downscaling simulations based on regional climate models, we investigated the future situation regarding the elevation dependency of climate warming on the Tibetan Plateau. The simulated air temperature trends from the six simulations are validated using meteorological station observations. The trends from only two simulations are selected for analysis due to their statistically significant correlation with the observations. The warming rate first increases to a peak and then slightly declines along with elevation increasing from 2000 m to 5600 m. The peak of the warming rate is reached at variable elevations (4400–5200 m), which depends on the intensity of the warming. The elevation at which this peak occurs increases when the warming intensifies. Such elevation‐dependent warming is mostly caused by the decrease in upward short‐wave radiation due to the depletion of snow based on surface energy budget analysis. These results provide some understanding of the future elevation‐dependent warming on the Tibetan Plateau, which will be useful for evaluating the sustainability of water resources of the Tibetan Plateau water‐affected area.
Patient‐Physician Discordance in Global Assessment in Rheumatoid Arthritis: A Systematic Literature Review With Meta‐Analysis
Authors: Desthieux Carole , Hermet Aurore , Granger Benjamin , Fautrel Bruno , Gossec Laure 
Published: April 2016

ObjectiveThe integration of the patient in therapeutic decision‐making is important in the management of rheumatoid arthritis (RA), but the patient opinion regarding disease status may differ from the physician's opinion. The aim of this study was to assess in the published literature the frequency and drivers of patient‐physician discordance in global assessment in RA.MethodsA systematic literature review of all articles published up to January 2015 in Medline or Embase, reporting discordance in RA, was conducted by 2 investigators. Discordance was defined based on the absolute difference of patient global (PGA) and physician global assessments (PhGA) on 0–10‐cm scales. The frequency of discordance and its predictors were collected in each study. Frequencies of discordance were pooled by meta‐analysis using random effect.ResultsIn all, 12 studies were selected (i.e., 11,879 patients): weighted mean ± SD age was 55.1 ± 13.9 years, weighted mean ± SD disease duration was 10.4 ± 9.3 years, and 80.7% were women. The value of the difference |PGA − PhGA| defining discordance varied between ≥0.5 cm (n = 2 studies) to ≥3 cm (n = 5 studies); the weighted mean value was 2.7 cm. The pooled percentage of patients with discordance was 43% (95% confidence interval 36%–51%; range 25%–76%). PGA was usually higher than PhGA. The drivers of PGA were pain and functional incapacity, whereas drivers of PhGA were joint counts and acute‐phase reactants.ConclusionDiscordance in global assessment was most frequently defined as a difference of 3 points or more; even with such a stringent definition, up to half the patients were found to be discordant. The long‐term consequences of this discordance remain to be determined.
Mapping Perceptions of Lupus Medication Decision‐Making Facilitators: The Importance of Patient Context
Authors: Qu Haiyan , Shewchuk Richard M. , Alarcón Graciela , Fraenkel Liana , Leong Amye , Dall'Era Maria , Yazdany Jinoos , Singh Jasvinder A. 
Published: April 2016

ObjectiveNumerous factors can impede or facilitate patients’ medication decision‐making and adherence to physicians’ recommendations. Little is known about how patients and physicians jointly view issues that affect the decision‐making process. Our objective was to derive an empirical framework of patient‐identified facilitators to lupus medication decision‐making from key stakeholders (including 15 physicians, 5 patients/patient advocates, and 8 medical professionals) using a patient‐centered cognitive mapping approach.MethodsWe used nominal group patient panels to identify facilitators to lupus treatment decision‐making. Stakeholders independently sorted the identified facilitators (n = 98) based on their similarities and rated the importance of each facilitator in patient decision‐making. Data were analyzed using multidimensional scaling and hierarchical cluster analysis.ResultsA cognitive map was derived that represents an empirical framework of facilitators for lupus treatment decisions from multiple stakeholders’ perspectives. The facilitator clusters were 1) hope for a normal/healthy life, 2) understand benefits and effectiveness of taking medications, 3) desire to minimize side effects, 4) medication‐related data, 5) medication effectiveness for “me,” 6) family focus, 7) confidence in physician, 8) medication research, 9) reassurance about medication, and 10) medication economics.ConclusionConsideration of how different stakeholders perceive the relative importance of lupus medication decision‐making clusters is an important step toward improving patient‐physician communication and effective shared decision‐making. The empirically derived framework of medication decision‐making facilitators can be used as a guide to develop a lupus decision aid that focuses on improving physician‐patient communication.
Mentoring Relationship Closures in Big Brothers Big Sisters Community Mentoring Programs: Patterns and Associated Risk Factors
Authors: DeWit David J. , DuBois David , Erdem Gizem , Larose Simon , Lipman Ellen L. , Spencer Renée 
Published: April 2016

AbstractPrevious research suggests that early mentoring relationship (MR) closures may have harmful consequences for the health and well‐being of youth participating in community‐based mentoring programs. However, knowledge of the factors that lead some MRs to close early has been slow to emerge. This study examined patterns and correlates of early versus on‐time MR closures among 569 youth participating in Big Brothers Big Sisters community mentoring programs. Thirty‐four percent of youth experienced an early MR closure prior to the end of the program's 12 month period of commitment. The probability of closure was highest at 12 months into the MR. Early closures were positively associated with youth gender (girls), behavioral difficulties, and match determination difficulties. Early and on‐time closures were associated with youth extrinsic motives for joining the program. Early MR closures were negatively associated with youth perceptions of parent emotional support, parent social support, high quality MR, weekly contact in MR, and parent support of the MR. Implications for programming are discussed.
Chiral Recognition of Carboxylates—Receptors, Analytical Tools, and More
Authors: Ulatowski Filip , Jurczak Janusz 
Published: April 2016

AbstractMost carboxylic acids, which are among the most common molecules in biological systems, are chiral. The enantiomers of these species are commonly distinguished in nature, but such recognition has proven quite difficult to reproduce by using artificial receptors. Better knowledge of the chiral recognition of carboxylates is therefore crucial for a full understanding of host–guest phenomena in nature, and also for the design of new analytical devices. In this Focus Review we summarize and discuss the methods employed to evaluate receptors, and present a variety of structural designs that have been utilized in chiral receptors. Some advanced functions of receptors in sensors and sensor arrays are also reviewed.
Copper‐Catalyzed Double Decarboxylative Coupling Reactions of Alkynyl Carboxylic Acid and Glyoxylic Acid: Synthesis of Propargyl Amines and Imidazopyridines
Authors: Choi Jinseop , Lim Jeongah , Irudayanathan Francis Mariaraj , Kim Han‐Sung , Park Jaerim , Yu Su Been , Jang Yuna , Raja Gabriel Charles Edwin , Nam Kye Chun , Kim Jimin , Lee Sunwoo 
Published: April 2016

AbstractThe reaction of alkynyl carboxylic acids, glyoxylic acid derivatives, and amines in the presence of a copper catalyst afforded the corresponding propargyl amines in good yields. The alkynyl carboxylic acid of this coupling reaction shows similar reactivity to that of a terminal alkyne, and the reactivity of the glyoxylic acid is almost identical to that of an aldehyde. When 2‐aminopyridine was employed as the amine source, imidazopyridine derivatives were formed in good yields.
Palladium‐Catalyzed Direct Amination of Allylic Alcohols in Aqueous Media
Authors: Du Zhengyin , Yan Yufei , Fu Ying , Wang Kehu 
Published: April 2016

AbstractPalladium chloride‐catalyzed amination of allylic alcohols with aromatic amines in the presence of triphenylphosphine and trifluoroacetic acid in the aqueous phase gave a wide range of allylamines in good to excellent yields under mild conditions. This protocol has a wide substrate scope and broad functional group tolerance. It is an environmentally friendly and highly atom‐economical method for N‐allylamine synthesis. A plausible mechanism involving a (π‐allyl)palladium complex intermediate is proposed.
Practice patterns in endoscopic dacryocystorhinostomy: survey of the American Rhinologic Society
Authors: Chen Sonia , Le Christopher H. , Liang Jonathan 
Published: April 2016

BackgroundThe introduction of advanced endoscopic techniques has facilitated significant growth in endoscopic dacryocystorhinostomy (EnDCR). The purpose of this study is to evaluate clinical practice patterns of otolaryngologists performing EnDCR.MethodsA 25‐item survey was electronically disseminated to the American Rhinologic Society (ARS) membership from November 17, 2014 to December 14, 2014. The target group encompassed 1157 ARS members.ResultsA total of 85 (7.3%) physicians completed the survey. EnDCR was performed by 87% of respondents. The annual average number of EnDCR cases ranged from 1 to 10 in 65% of respondents, 11 to 25 in 15%, 26 to 50 in 6%, and >50 in 1%. A total of 48% of respondents had some to a lot of DCR exposure during training, and 60% had completed a rhinology fellowship. Respondents frequently perform preoperative nasal endoscopy and computed tomography (CT) imaging, but very infrequently perform ophthalmologic workup. Lacrimal stents were used often or always in 80%, with 38% keeping stents in place for 6 to 8 weeks. The mucosal flap preservation technique was used often or always in 40%. Topical antimetabolites were used often or always in only 1%. Ophthalmology was present in most cases to perform lacrimal intubation. Postoperative antibiotics, topical ophthalmic steroids, and oral steroids were prescribed often or always in 62%, 47%, and 23%, respectively. Postoperative endoscopic debridement was performed often or always in 69%. A total of 81% of respondents followed DCR patients for >2 months, with 17% following these patients for >1 year.ConclusionThere is widespread integration of EnDCR procedures into rhinologic clinical practice among respondents. EnDCR practice patterns demonstrate moderate variation. In conjunction with evidence‐based medicine, these trends can highlight areas of controversy and help advance patient care.
Lewis‐Säure‐unterstützte metallkatalysierte Kreuzkupplung: Alkylierung von Arylmethylethern unter C‐O‐Bindungsspaltung ohne β‐Hydrideliminierung
Authors: Liu Xiangqian , Hsiao Chien‐Chi , Kalvet Indrek , Leiendecker Matthias , Guo Lin , Schoenebeck Franziska , Rueping Magnus 
Published: April 2016

AbstractDiverse Arylmethylether können durch Trialkylaluminiumverbindungen mittels einer Alkylierung unter C‐O‐Bindungsspaltung in wertvolle Produkte überführt werden, wobei die bislang limitierenden β‐Hydrideliminierungen vermieden werden. Basierend auf der Vielfalt natürlich vorhandener oder leicht zugänglicher Anisolderivate ermöglicht die neue Nickel‐katalysierte dealkoxylierende Alkylierung orthogonale Synthesestrategien, die zunächst die dirigierenden und/oder aktivierenden Eigenschaften von Methoxysubstituenten an aromatischen Systemen ausnutzen und diese anschließend durch eine Alkylkette ersetzen.
High‐Affinity Proton Donors Promote Proton‐Coupled Electron Transfer by Samarium Diiodide
Authors: Chciuk Tesia V. , Anderson William R. , Flowers Robert A. 
Published: April 2016

AbstractThe relationship between proton‐donor affinity for SmII ions and the reduction of two substrates (anthracene and benzyl chloride) was examined. A combination of spectroscopic, thermochemical, and kinetic studies show that only those proton donors that coordinate or chelate strongly to SmII promote anthracene reduction through a PCET process. These studies demonstrate that the combination of SmII ions and water does not provide a unique reagent system for formal hydrogen atom transfer to substrates.
An Iodine‐Vapor‐Induced Cyclization in a Crystalline Molecular Flask
Authors: Knichal Jane V. , Shepherd Helena J. , Wilson Chick C. , Raithby Paul R. , Gee William J. , Burrows Andrew D. 
Published: April 2016

AbstractA vapor‐induced cyclization has been observed in the host environment of a crystalline molecular flask (CMF), within which 1,8‐bis(2‐phenylethynyl)naphthalene (bpen), a diarenynyl system primed for cyclization, was exposed to iodine vapor to yield the corresponding indeno[2,1‐α]phenalene species. The cyclization process, unique in its vapor‐induced, solvent‐free nature, was followed spectroscopically, and found to occur concurrently with the displacement of lattice solvent for molecular iodine in CMF⋅0.75 bpen⋅2.25 CHCl3⋅H2O. The cyclization occurred under mild conditions and without the need to suspend the crystals in solvent. The ability of CMFs to host purely gas‐induced reactions is further highlighted by the subsequent sequential oxidation reaction of cyclized 7‐iodo‐12‐phenylindeno[2,1‐α]phenalene (ipp) with molecular oxygen derived from air, yielding 12‐hydroxy‐7‐iodo‐2‐phenylindeno[2,1‐α]phenalen‐1(12H)‐one (hipp).