bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterizing the extreme 2015 snowpack deficit in the Sierra Nevada (USA) and the implications for drought recovery
Authors: Margulis Steven A. , Cortés Gonzalo , Girotto Manuela , Huning Laurie S. , Li Dongyue , Durand Michael 
Published: June 2016

AbstractAnalysis of the Sierra Nevada (USA) snowpack using a new spatially distributed snow reanalysis data set, in combination with longer term in situ data, indicates that water year 2015 was a truly extreme (dry) year. The range‐wide peak snow volume was characterized by a return period of over 600 years (95% confidence interval between 100 and 4400 years) having a strong elevational gradient with a return period at lower elevations over an order of magnitude larger than those at higher elevations. The 2015 conditions, occurring on top of three previous drought years, led to an accumulated (multiyear) snowpack deficit of ~ −22 km3, the highest over the 65 years analyzed. Early estimates based on 1 April snow course data indicate that the snowpack drought deficit will not be overcome in 2016, despite historically strong El Niño conditions. Results based on a probabilistic Monte Carlo simulation show that recovery from the snowpack drought will likely take about 4 years.
Climate variability and extremes, interacting with nitrogen storage, amplify eutrophication risk
Authors: Lee Minjin , Shevliakova Elena , Malyshev Sergey , Milly P. C. D. , Jaffé Peter R. 
Published: June 2016

AbstractDespite 30 years of basin‐wide nutrient‐reduction efforts, severe hypoxia continues to be observed in the Chesapeake Bay. Here we demonstrate the critical influence of climate variability, interacting with accumulated nitrogen (N) over multidecades, on Susquehanna River dissolved nitrogen (DN) loads, known precursors of the hypoxia in the Bay. We used the process model LM3‐TAN (Terrestrial and Aquatic Nitrogen), which is capable of capturing both seasonal and decadal‐to‐century changes in vegetation‐soil‐river N storage, and produced nine scenarios of DN‐load distributions under different short‐term scenarios of climate variability and extremes. We illustrate that after 1 to 3 yearlong dry spells, the likelihood of exceeding a threshold DN load (56 kt yr−1) increases by 40 to 65% due to flushing of N accumulated throughout the dry spells and altered microbial processes. Our analyses suggest that possible future increases in climate variability/extremes—specifically, high precipitation occurring after multiyear dry spells—could likely lead to high DN‐load anomalies and hypoxia.
Magnetic reconnection and modification of the Hall physics due to cold ions at the magnetopause
Authors: André M. , Li W. , Toledo‐Redondo S. , Khotyaintsev Yu. V. , Vaivads A. , Graham D. B. , Norgren C. , Burch J. , Lindqvist P.‐A. , Marklund G. , Ergun R. , Torbert R. , Magnes W. , Russell C. T. , Giles B. , Moore T. E. , Chandler M. O. , Pollock C. , Young D. T. , Avanov L. A. , Dorelli J. C. , Gershman D. J. , Paterson W. R. , Lavraud B. , Saito Y. 
Published: June 2016

AbstractObservations by the four Magnetospheric Multiscale spacecraft are used to investigate the Hall physics of a magnetopause magnetic reconnection separatrix layer. Inside this layer of currents and strong normal electric fields, cold (eV) ions of ionospheric origin can remain frozen‐in together with the electrons. The cold ions reduce the Hall current. Using a generalized Ohm's law, the electric field is balanced by the sum of the terms corresponding to the Hall current, the v × B drifting cold ions, and the divergence of the electron pressure tensor. A mixture of hot and cold ions is common at the subsolar magnetopause. A mixture of length scales caused by a mixture of ion temperatures has significant effects on the Hall physics of magnetic reconnection.
Stress drop estimates and hypocenter relocations of induced seismicity near Crooked Lake, Alberta
Authors: Clerc Fiona , Harrington Rebecca M. , Liu Yajing , Gu Yu Jeffrey 
Published: June 2016

AbstractWe use a sequence of induced earthquakes near Crooked Lake, Alberta, to investigate the physical differences between induced and tectonic earthquakes. Starting with the Natural Resources Canada earthquake catalogue, we use a spectral ratio method to calculate the static stress drops of a group of relocated earthquakes ranging from December 2013 to June 2015. We find that stress drops fall within the high side of the typical reported range of tectonic events and show no correlation with earthquake magnitude, depth, or distance from the well. The stress drops appear roughly constant for events with Mw 3 to 4. Relocated hypocenters cluster both spatially and temporally around corresponding injection wells and appear to migrate deeper with increasing time from injection. Fine‐scale lineations apparent in relocated hypocenters could indicate the presence and orientation of fault planes, consistent with the published focal mechanism solutions of M 4+ events in the area.
The oceanic influence on the rainy season of Peninsular Florida
Authors: Misra Vasubandhu , Mishra Akhilesh 
Published: June 2016

AbstractIn this study we show that the robust surface ocean currents around Peninsular Florida, namely, the Loop and the Florida Currents, affect the terrestrial wet season of Peninsular Florida. We show this through two novel regional coupled ocean‐atmosphere models with different bathymetries that dislocate and modulate the strength of these currents and thereby affect the overlying sea surface temperature (SST) and upper ocean heat content. This study show that a weaker current system produces colder coastal SSTs along the Atlantic coast of Florida that reduces the length of the wet season and the total seasonal accumulation of precipitation over Peninsular Florida relative to the regional climate model simulation, in which these currents are stronger. The moisture budget reveals that as a result of these forced changes to the temperature of the upper coastal Atlantic Ocean, overlying surface evaporation and atmospheric convection is modulated. This consequently changes the moisture flux convergence leading to the modulation of the terrestrial wet season rainfall over Peninsular Florida that manifests in changes in the length and distribution of daily rain rate of the wet season. The results of this study have implications on interpreting future changes to hydroclimate of Peninsular Florida owing to climate change and low‐frequency changes to the Atlantic meridional overturning circulation that comprises the Loop and the Florida Currents as part of its upper branch.
Assessment of marine boundary layer cloud simulations in the CAM with CLUBB and updated microphysics scheme based on ARM observations from the Azores
Authors: Zheng X. , Klein S. A. , Ma H.‐Y. , Bogenschutz P. , Gettelman A. , Larson V. E. 
Published: June 2016

AbstractTo assess marine boundary layer (MBL) cloud simulations in three versions of the Community Atmosphere Model (CAM), three sets of short‐term global hindcasts are performed and compared to Atmospheric Radiation Measurement Program (ARM) observations on Graciosa Island in the Azores from June 2009 to December 2010. The three versions consist of CAM5.3 with default schemes (CAM5.3), CAM5.3 with Cloud Layers Unified By Binormals (CLUBB‐MG1), and CAM5.3 with CLUBB and updated microphysics scheme (CLUBB‐MG2). Our results show that relative to CAM5.3 default schemes, simulations with CLUBB better represent MBL cloud base height, the height of the major cloud layer, and the daily cloud cover variability. CLUBB also better simulates the relationship of cloud fraction to cloud liquid water path (LWP) most likely due to CLUBB's consistent treatment of these variables through a probability distribution function (PDF) approach. Subcloud evaporation of precipitation is substantially enhanced in simulations with CLUBB‐MG2 and is more realistic based on the limited observational estimate. Despite these improvements, all model versions underestimate MBL cloud cover. CLUBB‐MG2 reduces biases in in‐cloud LWP (clouds are not too bright) but there are still too few of MBL clouds due to an underestimate in the frequency of overcast scenes. Thus, combining CLUBB with MG2 scheme better simulates MBL cloud processes, but because biases remain in MBL cloud cover CLUBB‐MG2 does not improve the simulation of the surface shortwave cloud radiative effect (CRESW).
Aspects of the Chemical Energetics of Carbon–Aluminum Bonded Species
Authors: Slayden Suzanne W. , Liebman Joel F. 
Published: June 2016

Abstract

The current chapter discusses the chemical energetics of carbon‐aluminum bonded species, both the “conventional” trivalent organoaluminum compounds such as monomeric Me
3
Al and its dimer and a variety of species of often surprising stoichiometry and structure.

The study begins with the “simple” binary aluminum carbides, starting with AlC (neutral and ions). Incorporation of hydrogen leads to consideration of dimethylaluminum ionic compounds derived from the cationic [Me
2
Al]
+
and anionic [Me
2
AlO]
−
.

Methyldialuminum species with one Al–Al bond and at least one Al–C bond, ranging from [Al
2
Me]
+
to [Al
2
Me
7
]
−
, are then examined.

The experimental enthalpies of formation, vaporization and dimerization of trialkylalanes are tabulated. The most recent enthalpy of formation value for Et3Al is used to recommend slightly revised enthalpies of formation for trialkylalanes and the related alkylaluminum hydrides and halides.
The interplay of aluminum and aromaticity is reviewed in the context of aluminum rich rings and clusters, relatively classical heterocycles such as aluminoles, and binding of neutral and cationic monoatomic Al with aromatics.
The chapter closes with a discussion of aluminum halide complexes of benzene and cyclobutadiene derivatives.
Neurologic syndrome associated with homozygous mutation at MAG sialic acid binding site
Authors: Roda Ricardo H. , FitzGibbon Edmond J. , Boucekkine Houda , Schindler Alice B. , Blackstone Craig 
Published: June 2016

AbstractThe MAG gene encodes myelin‐associated glycoprotein (MAG), an abundant protein involved in axon–glial interactions and myelination during nerve regeneration. Several members of a consanguineous family with a clinical syndrome reminiscent of Pelizaeus–Merzbacher disease and demyelinating leukodystrophy on brain MRI were recently found to harbor a homozygous missense p.Ser133Arg MAG mutation. Here, we report two brothers from a nonconsanguineous family afflicted with progressive cognitive impairment, neuropathy, ataxia, nystagmus, and gait disorder. Exome sequencing revealed the homozygous missense mutation p.Arg118His in MAG. This Arg118 residue in immunoglobulin domain 1 is critical for sialic acid binding, providing a compelling mechanistic basis for disease pathogenesis.
Acetyl Bromide Promoted Sequence via Allene Intermediates: Metal‐Free Construction of 2,3‐Dihydroindenes and Isoindolines
Authors: Liu Le , Yao Jinzhong , Chen Dianpeng , Zhou Hongwei 
Published: June 2016

Abstract2,3‐Dihydroindenes and isoindolines are important skeletons present in medicinal and synthetic chemistry. In this paper, an acetyl bromide promoted metal‐free construction of 2,3‐dihydroindenes and isoindolines with high synthetic efficiency is developed.magnified image
Lösungsprozessierte MoS2‐Nanoplättchen: Herstellung, Hybridisierung und Anwendungen
Authors: Zhang Xiao , Lai Zhuangchai , Tan Chaoliang , Zhang Hua 
Published: June 2016

AbstractMoS2‐Nanoplättchen gehören zu einer neuen Klasse dünner zweidimensionaler Übergangsmetalldichalkogenid‐Nanomaterialien. Aufgrund ihrer einzigartigen Struktur und faszinierenden Eigenschaften sind sie sehr interessant für die Forschung. Lösungsbasierte Verfahren sind vielversprechende Methoden für die skalierbare Herstellung, Funktionalisierung und Hybridisierung von MoS2‐Nanoplättchen und ermöglichen so die Erforschung von MoS2‐Nanomaterialien für verschiedene interessante Anwendungen. Dieser Aufsatz gibt einen Überblick über die aktuellen Fortschritte bei der Herstellung und Weiterverarbeitung von MoS2‐Nanoplättchen in Lösung. Besonderes Augenmerk gilt den Synthesestrategien, der Funktionalisierung und Hybridisierung sowie Eigenschaften und Anwendungen. Abschließend werden die Herausforderungen und Zukunftsaussichten dieses sehr aktuellen Forschungsgebiets besprochen.
Oxidationsreaktionen mit bioinspirierten einkernigen Nicht‐Häm‐Oxidometallkomplexen
Authors: Engelmann Xenia , Monte‐Pérez Inés , Ray Kallol 
Published: June 2016

AbstractDie selektive Funktionalisierung starker C‐H‐Bindungen sowie die Oxidation von Wasser durch preiswerte und ungiftige Metalle sind einige der Schlüsselziele der heutigen chemischen Forschung. Es wurde vorgeschlagen, dass hochvalente Eisen‐, Mangan‐ und Kupferkerne als reaktive Intermediate an diesen wichtigen Oxidationsreaktionen, die von biologischen Systemen ausgeführt werden, beteiligt sind, was sie zu begehrten Zielobjekten für biomimetische Synthesestudien macht. Die Herstellung und Charakterisierung von Modell‐Oxidometallkomplexen von Eisen, Mangan und Kupfer, zusammen mit detaillierten Reaktivitätsstudien, kann dazu beitragen, die Rolle der sterischen und elektronischen Eigenschaften der Metallzentren zur Regulierung der Reaktivität entsprechender Metalloenzyme zu verstehen. Dieser Aufsatz bietet einen fokussierten Rückblick auf die jüngsten Fortschritte in der biomimetischen Komplexchemie hochvalenter Oxidometallkerne der letzten fünf bis zehn Jahre, die mit unserem Verständnis von biologischen Systemen in Beziehung gebracht werden können.
Synthese von Aeruginosin‐Chlorsulfopeptiden und Untersuchung ihrer Toxizität
Authors: Scherer Manuel , Bezold Dominik , Gademann Karl 
Published: June 2016

AbstractGesundheitsschädliche Algenblüten treten weltweit immer häufiger auf. Daher bedarf es Studien zur Identifikation der verantwortlichen Toxine sowie zu deren Wirkmechanismus, um die Ökosysteme inklusive der betroffenen Menschen und Tiere schützen zu können. In der hier vorgestellten Arbeit wurde das Chlorsulfopeptid Aeruginosin 828A, das für Krebstiere ähnlich toxisch ist wie das bekannte Microcystin‐LR, erstmals synthetisiert. Darüber hinaus wurden drei Kongenere mit verschiedenen Permutationen der Chlorid‐ und Sulfat‐Substituenten hergestellt, mit denen Toxizitätsstudien ohne das Risiko von Kontaminationen durch andere natürliche Toxine durchgeführt werden konnten. In einem Toxizitätsassay mit dem empfindlichen Biberschwanzfeenkrebs (Thamnocephalus platyurus) zeigte sich, dass die Toxizität in Gegenwart der Sulfat‐Gruppe hoch ist, während das Chlorid‐Derivat NMR‐spektroskopischen Untersuchungen zufolge eine andere Konformation einnimmt, was die Protease‐Inhibition beeinflussen könnte.
The Cation–π Interaction in Small‐Molecule Catalysis
Authors: Kennedy C. Rose , Lin Song , Jacobsen Eric N. 
Published: June 2016

AbstractCatalysis by small molecules (≤1000 Da, 10−9 m) that are capable of binding and activating substrates through attractive, noncovalent interactions has emerged as an important approach in organic and organometallic chemistry. While the canonical noncovalent interactions, including hydrogen bonding, ion pairing, and π stacking, have become mainstays of catalyst design, the cation–π interaction has been comparatively underutilized in this context since its discovery in the 1980s. However, like a hydrogen bond, the cation–π interaction exhibits a typical binding affinity of several kcal mol−1 with substantial directionality. These properties render it attractive as a design element for the development of small‐molecule catalysts, and in recent years, the catalysis community has begun to take advantage of these features, drawing inspiration from pioneering research in molecular recognition and structural biology. This Review surveys the burgeoning application of the cation–π interaction in catalysis.
Investigating the Toxicity of the Aeruginosin Chlorosulfopeptides by Chemical Synthesis
Authors: Scherer Manuel , Bezold Dominik , Gademann Karl 
Published: June 2016

AbstractHarmful algal blooms are becoming more prevalent all over the world, and identification and mechanism‐of‐action studies of the responsible toxins serve to protect ecosystems, livestock, and humans alike. In this study, the chlorosulfopeptide aeruginosin 828A, which rivals the well‐known toxin microcystin LR in terms of crustacean toxicity, has been synthesized for the first time. Furthermore, three congeners with different permutations of the chloride and sulfate groups were prepared, thereby enabling toxicity studies without the risk of contamination by other natural toxins. Toxicity assays with the sensitive crustacean Thamnocephalus platyurus demonstrated that the introduction of a sulfate group leads to pronounced toxicity, and NMR spectroscopic evidence suggests that the chloride substituent modulates the conformation, which in turn might influence protease inhibition.
Asymmetric Desymmetrization via Metal‐Free C−F Bond Activation: Synthesis of 3,5‐Diaryl‐5‐fluoromethyloxazolidin‐2‐ones with Quaternary Carbon Centers
Authors: Tanaka Junki , Suzuki Satoru , Tokunaga Etsuko , Haufe Günter , Shibata Norio 
Published: June 2016

AbstractWe disclose the first asymmetric activation of a non‐activated aliphatic C−F bond in which a conceptually new desymmetrization of 1,3‐difluorides by silicon‐induced selective C−F bond scission is a key step. The combination of a cinchona alkaloid based chiral ammonium bifluoride catalyst and N,O‐bis(trimethylsilyl)acetoamide (BSA) as the silicon reagent enabled the efficient catalytic cycle of asymmetric Csp3−F bond cleavage under mild conditions with high enantioselectivities. The ortho effect of the aryl group at the prostereogenic center is remarkable. This concept was applied for the asymmetric synthesis of promising agrochemical compounds, 3,5‐diaryl‐5‐fluoromethyloxazolidin‐2‐ones bearing a quaternary carbon center.
Correlation of Secretory Activity of Neutrophils With Genotype in Patients With Familial Mediterranean Fever
Authors: Gohar Faekah , Orak Banu , Kallinich Tilmann , Jeske Marion , Lieber Mareike , von Bernuth Horst , Giese Arnd , Weissbarth‐Riedel Elisabeth , Haas Johannes‐Peter , Dressler Frank , Holzinger Dirk , Lohse Peter , Neudorf Ulrich , Lainka Elke , Hinze Claas , Masjosthusmann Katja , Kessel Christoph , Weinhage Toni , Foell Dirk , Wittkowski Helmut 
Published: June 2016

ObjectiveFamilial Mediterranean fever (FMF) is an autoinflammatory disorder caused by pyrin‐encoding MEFV mutations. Patients present with recurrent but self‐limiting episodes of acute inflammation and often have persistent subclinical inflammation. The pathophysiology is only partially understood, but neutrophil overactivation is a hallmark of the disease. S100A12 is a neutrophil‐derived proinflammatory danger signal that is strongly elevated in active FMF. This study was undertaken to characterize the secretory activity of neutrophils in vitro and investigate the association of S100A12 with disease activity and genotype in patients with FMF.MethodsNeutrophils from FMF patients carrying the p.M694V mutation (1 compound heterozygous and 5 homozygous) and neutrophils from 4 healthy control subjects were purified and stimulated in vitro. Neutrophil secretion of S100A12, interleukin‐18 (IL‐18), IL‐1β, and caspase 1 was determined. Based on these in vitro analyses, serum concentrations of S100A12, IL‐18, and IL‐1β were also analyzed in 128 clinically and genetically characterized patients with FMF.ResultsIn vitro, unstimulated neutrophils from p.M694V‐positive patients spontaneously secreted more S100A12, IL‐18, and caspase 1 compared to neutrophils from healthy controls. Serum concentrations of S100A12 correlated with disease activity and genotype, with the levels being highest in homozygous patients and with compound heterozygotes displaying higher levels than heterozygotes. Compared to individuals negative for the p.M694V mutation, heterozygous, compound heterozygous, or homozygous p.M694V‐positive patients had higher serum levels of S100A12 and IL‐18 during inactive and subclinical disease.ConclusionThe FMF phenotype is known to be more severe in patients carrying the p.M694V mutation. This report describes 2 molecules secreted by unconventional secretory pathways, S100A12 and IL‐18, whose concentrations correlated with clinical disease activity and genotype in patients with FMF. In this clinically and genetically heterogeneous disease, management of these surrogate markers might help to improve patient care and outcomes.
Suppression of Inflammatory Arthritis by Human Gut‐DerivedPrevotella histicolain Humanized Mice
Authors: Marietta Eric V. , Murray Joseph A. , Luckey David H. , Jeraldo Patricio R. , Lamba Abhinav , Patel Robin , Luthra Harvinder S. , Mangalam Ashutosh , Taneja Veena 
Published: June 2016

ObjectiveThe gut microbiome regulates host immune homeostasis. Rheumatoid arthritis (RA) is associated with intestinal dysbiosis. This study was undertaken to test the ability of a human gut‐derived commensal to modulate immune response and treat arthritis in a humanized mouse model.MethodsWe isolated a commensal bacterium,Prevotella histicola,that is native to the human gut and has systemic immune effects when administered enterally. Arthritis‐susceptible HLA–DQ8 mice were immunized with type II collagen and treated withP histicola. Disease incidence, onset, and severity were monitored. Changes in gut epithelial proteins and immune response as well as systemic cellular and humoral immune responses were studied in treated mice.ResultsWhen treated withP histicolain prophylactic or therapeutic protocols, DQ8 mice exhibited significantly decreased incidence and severity of arthritis compared to controls. The microbial mucosal modulation of arthritis was dependent on regulation by CD103+ dendritic cells and myeloid suppressors (CD11b+Gr‐1+ cells) and by generation of Treg cells (CD4+CD25+FoxP3+) in the gut, resulting in suppression of antigen‐specific Th17 responses and increased transcription of interleukin‐10. Treatment withP histicolaled to reduced intestinal permeability by increasing expression of enzymes that produce antimicrobial peptides as well as tight junction proteins (zonula occludens 1 and occludin). However, the innate immune response via Toll‐like receptor 4 (TLR‐4) and TLR‐9 was not affected in treated mice.ConclusionOur results demonstrate that enteral exposure toP histicolasuppresses arthritis via mucosal regulation.P histicolais a unique commensal that can be explored as a novel therapy for RA and may have few or no side effects.