bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mitigation of drought negative effect on ecosystem productivity by vegetation mixing
Authors: Van den Hoof Catherine , Lambert Fabrice 
Published: October 2016

AbstractVegetation diversity and interaction is thought to have a beneficial effect on ecosystem functioning, particularly improving ecosystem resistance to drought. This is of significant importance in the context of a warmer world, as extreme events such as droughts become more likely. Most of the studies performed so far on vegetation interaction are based on observations. Here we use the land surface model JULES to study the potential of vegetation mixing to mitigate the negative effect of drought events on the land surface through interaction, a mechanism which is difficult to study in situ at large scales. Using a set of simulations with mixed and unmixed vegetation, we show that the carbon, water, and energy fluxes are significantly affected by vegetation competition for water resources. The interaction is in general beneficial for the ecosystem carbon assimilation due to a better use of water resources. This benefit is highest when traits between vegetation types concerning resource competition overlap least. For a tree‐grass combination, mixing improves carbon assimilation by 5% to 8% during summer. The benefit of mixing increases further under progressively more resource‐limited conditions up to an inflection point with a benefit of 14%, after which it falls back to zero under extremely dry conditions. Mixing also tends to reduce the interannual variability of the ecosystem carbon sink and therefore improves the resistance of the ecosystem. Our results highlight the importance of vegetation interaction in climate simulations and impact studies and the potential of vegetation mixing as a mitigation tool.
Modeling geomagnetic induction hazards using a 3‐D electrical conductivity model of Australia
Authors: Wang Liejun , Lewis Andrew M. , Ogawa Yasuo , Jones William V. , Costelloe Marina T. 
Published: October 2016

AbstractThe surface electric field induced by external geomagnetic source fields is modeled for a continental‐scale 3‐D electrical conductivity model of Australia at periods of a few minutes to a few hours. The amplitude and orientation of the induced electric field at periods of 360 s and 1800 s are presented and compared to those derived from a simplified ocean‐continent (OC) electrical conductivity model. It is found that the induced electric field in the Australian region is distorted by the heterogeneous continental electrical conductivity structures and surrounding oceans. On the northern coastlines, the induced electric field is decreased relative to the simple OC model due to a reduced conductivity contrast between the seas and the enhanced conductivity structures inland. In central Australia, the induced electric field is less distorted with respect to the OC model as the location is remote from the oceans, but inland crustal high‐conductivity anomalies are the major source of distortion of the induced electric field. In the west of the continent, the lower conductivity of the Western Australia Craton increases the conductivity contrast between the deeper oceans and land and significantly enhances the induced electric field. Generally, the induced electric field in southern Australia, south of latitude −20°, is higher compared to northern Australia. This paper provides a regional indicator of geomagnetic induction hazards across Australia.
Diel discharge cycles explained through viscosity fluctuations in riparian inflow
Authors: Schwab Michael , Klaus Julian , Pfister Laurent , Weiler Markus 
Published: October 2016

AbstractDiel (also called diurnal) discharge patterns with minima in the afternoon are generally explained by the daily cycle of evapotranspiration, while maxima in the afternoon are often linked to freeze‐thaw cycles. In a schistose and forested headwater catchment in Luxembourg, we observed daily discharge maxima in the afternoon, although temperatures remained persistently above zero and vegetation was still in a dormant state. We show that diel water temperature fluctuations––and therefore viscosity fluctuations––in the upper layer of the riparian zone can be an explanation for the observed daily discharge maxima in the afternoon during the dormant season. In the transition period between the dormant and the growing season, the counteracting viscosity and evapotranspiration processes cancel each other out. Subsequently, during the growing season, evapotranspiration is the dominant process guiding the diel discharge pattern; nevertheless, the viscosity effect might still be present, but invisible. We believe this finding also to be of relevance when analyzing daily fluctuations of biogeochemicals in stream water.
Drainage mechanisms in porous media: From piston‐like invasion to formation of corner flow networks
Authors: Hoogland Frouke , Lehmann Peter , Mokso Rajmund , Or Dani 
Published: October 2016

AbstractWater drainage from porous media is a highly dynamic process often marked by rapid piston‐like air invasion events at the front and other rapid interfacial reconfigurations. Liquid phase entrapped behind the moving front drains at significantly slower rates often via gravity driven flow through corners and crevices. This distribution of slowly draining residual water phase determines the plant available water and biological functioning of soils. The study aims to determine the conditions for the flow regime transition from piston‐like invasion at a drainage front to slower corner dominated flow at the pore and sample scale. This transition was observed experimentally for sand and glass beads with fast X‐ray tomography, revealing water fragmentation into clusters of full pores interconnected by water corner films. The observed liquid morphology at the transition from piston to corner flow was reproduced by a quasi‐static pore network model and predicted by percolation theory. The amount of capillary‐retained water at flow transition controlling the subsequent drainage dynamics could be reproduced by an idealized star shaped pore whose geometry is deduced from macroscopic properties of the porous medium. Predictions of water content thresholds at flow transitions were in agreement with other critical saturation values associated with cessation of solute diffusion and of internal drainage (at field capacity) highlighting the criticality of water phase continuity disruption for formation of relatively stable unsaturated conditions controlled by slow corner flow that support life in soil.
Novel NALCN variant: altered respiratory and circadian rhythm, anesthetic sensitivity
Authors: Lozic Bernarda , Johansson Stefan , Lovric Kojundzic Sanja , Markic Josko , Knappskog Per Morten , Hahn Angelika F. , Boman Helge 
Published: October 2016

AbstractThe sodium leak channel, a Na+‐permeable, nonselective cation channel, is widely expressed in the nervous system, contributing a basal Na+‐leak conductance and regulating neuronal excitability. A 3‐year‐old girl, heterozygous for a de novo missense mutation in NALCN (c.956C>T; p.Ala319Val) predicted to be deleterious, presented from birth with: stimulus‐induced, episodic contractures of the limbs and face with associated respiratory distress; distal arthrogryposis; severe axial hypotonia; and severe global developmental delay (CLIFAHDD syndrome). In infancy, she manifested a reversed sleep‐wake rhythm, nocturnal life‐threatening respiratory rhythm disturbances with central apnea. Sevoflurane sensitivity caused respiratory depression and cardiac arrest.
Mud‐Bath Therapy in Addition to Usual Care in Bilateral Knee Osteoarthritis: An Economic Evaluation Alongside a Randomized Controlled Trial
Authors: Ciani Oriana , Pascarelli Nicola Antonio , Giannitti Chiara , Galeazzi Mauro , Meregaglia Michela , Fattore Giovanni , Fioravanti Antonella 
Published: October 2016

ObjectiveTo perform a cost‐effectiveness analysis of mud‐bath therapy (MBT) in addition to usual treatment compared to usual treatment alone in patients with bilateral knee osteoarthritis (OA).MethodsAn economic evaluation alongside a randomized controlled trial was conducted. Patients were randomly assigned to receive either a 2‐week cycle of MBT in addition to their usual treatment or to continue routine care alone. The EuroQol 5‐domain questionnaire was administered at baseline, 2 weeks, and at 3, 6, 9, and 12 months. Direct health care resource consumption data up until 12 months were derived from a daily diary given to patients and returned at prescheduled followup visits.ResultsA total of 103 patients were included (n = 53 for MBT patients; n = 50 for controls). Overall, patients in the MBT group accrued mean ± SD 0.835 ± 0.10 quality‐adjusted life years (QALYs) compared to 0.753 ± 0.11 in the control group (P < 0.001). Average direct costs per patient (€303 versus €975; P < 0.001) were higher in the control group, primarily because of hospitalization for total knee replacement and use of intraarticular hyaluronic acid. Bootstrapping replications of costs and QALY sample distributions consistently indicated that the MBT therapy combined with standard therapy represents a dominant strategy as compared with standard therapy alone. The probability of MBT being cost‐effective at standard cost‐effectiveness thresholds (e.g., €20,000/QALY) is 100%.ConclusionThe results of this cost‐effectiveness analysis support the use of MBT as midterm complementary therapy in the management of knee OA.
Results of an Observational Cohort Study of Hyperuricemia as a Predictor of Poor Physical Performance in the Elderly
Authors: Veronese Nicola , Stubbs Brendon , Trevisan Caterina , Bolzetta Francesco , De Rui Marina , Maggi Stefania , Sartori Leonardo , Musacchio Estella , Zambon Sabina , Perissinotto Egle , Noale Marianna , Crepaldi Gaetano , Manzato Enzo , Sergi Giuseppe 
Published: October 2016

ObjectiveHyperuricemia is frequent in older people and associated with several medical conditions. The relationship between hyperuricemia and physical performance is limited. We aimed to investigate the association between hyperuricemia and physical performance over a 4.4‐year followup in the elderly.MethodsA total of 1,904 community‐dwelling older participants were followed for a mean of 4.4 years. Hyperuricemia at baseline was defined using serum uric acid concentrations ≥6 and ≥7 mg/dl for women and men, respectively. Objective physical performance tests measured included the Short Physical Performance Battery (SPPB), 4‐meter gait speed, chair‐stands time, leg extension and flexion, handgrip strength, and the 6‐minute walking test.ResultsAt baseline, participants with hyperuricemia (n = 98 men, 232 women) scored significantly worse in all the tests investigated. After adjusting for 19 covariates, men with hyperuricemia at baseline had an increased risk of having poor SPPB scores at followup (odds ratio [OR] 1.44 [95% confidence interval (95% CI) 1.21–1.72]; P < 0.0001), poor chair‐stands time (OR 1.40 [95% CI 1.18–1.6]; P < 0.0001), poor leg extension (OR 1.47 [95% CI 1.21–1.7]; P < 0.0001), and poor handgrip strength (OR 1.54 [95% CI 1.24–1.90]; P < 0.0001). Among women, hyperuricemia was associated with an increased risk of having poor scores in all the SPPB items and in leg flexion (OR 1.26 [95% CI 1.08–1.49]; P = 0.03).ConclusionHyperuricemia seems to be significantly associated with poor physical performance in older people, over a followup of 4.4 years. The relationship appears to be more consistent in men than in women. Further longitudinal research is required to better understand the relationships and potential biologic pathways.
A High Performance Stretchable Asymmetric Fiber‐Shaped Supercapacitor with a Core‐Sheath Helical Structure
Authors: Yu Jiali , Lu Weibang , Smith Joseph P. , Booksh Karl S. , Meng Linghui , Huang Yudong , Li Qingwen , Byun Joon‐Hyung , Oh Youngseok , Yan Yushan , Chou Tsu‐Wei 
Published: October 2016

The emerging fiber‐shaped supercapacitors (FSSs) have motivated tremendous research interest in energy storage devices. However, challenges still exist in the pursuit of combination of excellent electrochemical performance and mechanical stretchability. Here, a core‐sheath asymmetric FSS is first made by wrapping gel electrolyte coated carbon nanotube (CNT)@MnO2 core fiber with CNT@PPy composite film. Then a stretchable helical structure is formed by over‐twisting the FSS. The resulted stretchable asymmetric FSS exhibits a specific capacitance of 60.435 mF cm−2 at the scan rate of 10 mV s−1 and the capacitance performance is well maintained during repeated stretching to 20% strain. Furthermore, a high energy density of 18.88 μW h cm−2 is achieved for the stretchable FSS due to its high specific capacitance and extended potential window of 1.5 V.
Physical activity patterns and biomarkers of cardiovascular disease risk in hunter‐gatherers
Authors: Raichlen David A. , Pontzer Herman , Harris Jacob A. , Mabulla Audax Z. P. , Marlowe Frank W. , Josh Snodgrass J. , Eick Geeta , Colette Berbesque J. , Sancilio Amelia , Wood Brian M. 
Published: October 2016

AbstractObjectivesTime spent in moderate‐to‐vigorous physical activity (MVPA) is a strong predictor of cardiovascular health, yet few humans living in industrialized societies meet current recommendations (150 min/week). Researchers have long suggested that human physiological requirements for aerobic exercise reflect an evolutionary shift to a hunting and gathering foraging strategy, and a recent transition to more sedentary lifestyles likely represents a mismatch with our past in terms of physical activity. The goal of this study is to explore this mismatch by characterizing MVPA and cardiovascular health in the Hadza, a modern hunting and gathering population living in Northern Tanzania.MethodsWe measured MVPA using continuous heart rate monitoring in 46 participants recruited from two Hadza camps. As part of a larger survey of health in the Hadza, we measured blood pressure (n = 198) and biomarkers of cardiovascular health (n = 23) including C‐reactive protein, cholesterol (Total, HDL, and LDL), and triglycerides.ResultsWe show that Hadza participants spend large amounts of time in MVPA (134.92 ± 8.6 min/day), and maintain these activity levels across the lifespan. In fact, the Hadza engage in over 14 times as much MVPA as subjects participating in large epidemiological studies in the United States. We found no evidence of risk factors for cardiovascular disease in this population (low prevalence of hypertension across the lifespan, optimal levels for biomarkers of cardiovascular health).ConclusionsOur results provide evidence that the hunting and gathering foraging strategy involves high levels of MVPA, supporting the evolutionary medicine model for the relationship between MVPA and cardiovascular health.
Finsler geometry of topological singularities for multi‐valued fields: Applications to continuum theory of defects
Authors: Yajima Takahiro , Nagahama Hiroyuki 
Published: October 2016

Topological singularity in a continuum theory of defects and a quantum field theory is studied from a viewpoint of differential geometry. The integrability conditions of singularity (Clairaut‐Schwarz‐Young theorem) are expressed by a torsion tensor and a curvature tensor when a Finslerian intrinsic parallelism holds for the multi‐valued function. In the context of the quantum field theory, the singularity called an extended object is expressed by the torsion when the intrinsic parallelism is related to the spontaneous breakdown of symmetry. In the continuum theory of defects, the path‐dependency of point and line defects within a crystal is interpreted by the non‐vanishing condition of torsion tensor in a non‐Riemannian space osculated from the Finsler space, and the domain is not simply connected. On the other hand, for the rotational singularity, an energy integral (J‐integral) around a disclination field is path‐independent when a nonlinear connection is single‐valued. This means that the topological expression for the sole defect (Gauss‐Bonnet theorem with genus ) is understood by the integrability of nonlinear connection.image
Silyl Formates as Surrogates of Hydrosilanes and Their Application in the Transfer Hydrosilylation of Aldehydes
Authors: Chauvier Clément , Thuéry Pierre , Cantat Thibault 
Published: October 2016

AbstractSilyl formates are investigated for the first time as surrogates of hydrosilanes. In the presence of a well‐defined ruthenium catalyst, these reagents are shown to promote the chemoselective reduction of a variety of aldehydes by transfer hydrosilylation. Mechanistic investigations have shown that genuine hydrosilane species are avoided during catalysis. The mechanism involves a sequence of decarboxylation/insertion/transmetallation steps.
Characterization and Reactivity Studies of a Terminal Copper–Nitrene Species
Authors: Corona Teresa , Ribas Lídia , Rovira Mireia , Farquhar Erik R. , Ribas Xavi , Ray Kallol , Company Anna 
Published: October 2016

AbstractHigh‐valent terminal copper–nitrene species have been postulated as key intermediates in copper‐catalyzed aziridination and amination reactions. The high reactivity of these intermediates has prevented their characterization for decades, thereby making the mechanisms ambiguous. Very recently, the Lewis acid adduct of a copper–nitrene intermediate was trapped at −90 °C and shown to be active in various oxidation reactions. Herein, we describe for the first time the synthesis and spectroscopic characterization of a terminal copper(II)–nitrene radical species that is stable at room temperature in the absence of any Lewis acid. The azide derivative of a triazamacrocyclic ligand that had previously been utilized in the stabilization of aryl–CuIII intermediates was employed as an ancillary ligand in the study. The terminal copper(II)–nitrene radical species is able to transfer a nitrene moiety to phosphines and abstract a hydrogen atom from weak C−H bonds, leading to the formation of oxidized products in modest yields.
A Cooperative Strategy for the Highly Selective Intermolecular Oxycarbonylation Reaction of Alkenes using a Palladium Catalyst
Authors: Li Ming , Yu Feng , Qi Xiaoxu , Chen Pinhong , Liu Guosheng 
Published: October 2016

AbstractA novel method for intermolecular functionalization of terminal and internal alkenes has been designed. The electrophilic reagent, hypervalent iodine, plays a key role in this process by activating the alkene C=C bond for nucleophilic addition of the palladium catalyst. This process generates an iodonium‐containing palladium species which undergoes CO insertion. The new approach, intermolecular oxycarbonylaton reactions of alkenes, has been achieved and carried out under mild reaction conditions to produce the corresponding β‐oxycarbonylic acids with excellent efficiencies and levels of regio‐ and diastereoselectivity.
Solvens‐induzierte reduktive Aktivierung von CO2 durch Bismut und Änderung des Reaktionsprodukts von Metalloformiat nach Oxalat
Authors: Thompson Michael C. , Ramsay Jacob , Weber J. Mathias 
Published: October 2016

AbstractEs wurde untersucht, wie sich die reduktive Aktivierung von CO2 durch einen atomaren Bi‐Modellkatalysator unter aprotischer Solvatisierung verändert. Infrarot‐Photodissoziationsspektroskopie massenselektierter [Bi(CO2)n]−‐Clusterionen wurde genutzt, um die Strukturveränderung der molekularen ionischen Kerne dieser Cluster bei wachsender Clustergröße zu verfolgen. Die Interpretation der Infrarotspektren erfolgte durch Vergleich mit Ergebnissen auf der Basis von Dichtefunktionaltheorie. Die Resultate zeigen, dass CO2 mit Bi in Gegenwart eines Zusatzelektrons ein Metalloformiat‐Ion (BiCOO−) bildet. Solvatisierung durch zusätzliche CO2‐Moleküle führt zur Stabilisierung eines BiI‐Oxalat‐Komplexes und damit zur Änderung des Kernions.
Direct Synthesis of Pyrroles by Dehydrogenative Coupling of Diols and Amines Catalyzed by Cobalt Pincer Complexes
Authors: Daw Prosenjit , Chakraborty Subrata , Garg Jai Anand , Ben‐David Yehoshoa , Milstein David 
Published: October 2016

AbstractHerein, the first example of base‐metal‐catalyzed dehydrogenative coupling of diols and amines to selectively form functionalized 1,2,5‐substituted pyrroles liberating water and hydrogen gas as the sole by‐products is presented. The reaction is catalyzed by pincer complexes of earth‐abundant cobalt.
Convergent Assembly of the Tetracyclic Meroterpenoid (−)‐Cyclosmenospongine by a Non‐Biomimetic Polyene Cyclization
Authors: Speck Klaus , Wildermuth Raphael , Magauer Thomas 
Published: October 2016

AbstractThe cationic cyclization of polyenes constitutes a powerful and elegant transformation, which has been utilized by nature's biosynthetic machinery for the construction of complex polycyclic terpenoids. Previous studies by chemists to mimic this cyclization in the laboratory were limited to different modes of activation using biosynthetic‐like precursors, which accommodate only simple methyl‐derived substituents. Here we describe the development of an unprecedented and highly efficient polyene cyclization of an aryl enol ether containing substrate. The cyclization was shown to proceed in a stepwise manner to generate three rings and three consecutive stereocenters, two of which are tetrasubstituted, in a single flask. The developed transformation is of great synthetic value and has enabled the convergent assembly of the tetracyclic meroterpenoid (−)‐cyclosmenospongine.
Absolut minimales Sampling in der hochdimensionalen NMR‐Spektroskopie
Authors: Hansen Alexandar L. , Brüschweiler Rafael 
Published: October 2016

AbstractStandardmäßige dreidimensionale (3D‐)Fourier‐Transformations(FT)‐NMR‐Experimente von molekularen Systemen erfordern häufig lange Messzeiten, die durch das umfangreiche Sampling entlang der indirekten Zeitbereiche verursacht werden, damit eine hinreichende spektrale Auflösung erhalten werden kann. In den letzten Jahren wurde eine Fülle von alternativen Sampling‐Methoden vorgeschlagen, um diesen Engpass zu vermeiden. Aufgrund ihrer algorithmischen Komplexität für vorgegebene NMR‐Proben und Experimente ist es jedoch häufig schwierig, die minimale Abtastinformation und die damit verbundene minimale Messzeit zu bestimmen. Hier wird die Methode des absoluten minimalen Samplings (AMS) vorgestellt, die auf gängige 3D‐NMR‐Experimente angewendet werden kann. Für die Proteine Ubiquitin und Arginin‐Kinase wird gezeigt, wie man für das weitverbreitete 3D‐HNCO‐Experiment präzise Kohlenstofffrequenzen mithilfe eines einzigen Zeitinkrements erhält, während für andere, z. B. das 3D‐HN(CA)CO‐Experiment, alle relevanten Informationen in nur sechs Schritten erhältlich sind, wodurch eine Beschleunigung um einen Faktor 7–50 erreicht wird.
Strukturelle Grundlage der Transkription: 10 Jahre nach dem Chemie‐Nobelpreis
Authors: Hantsche Merle , Cramer Patrick 
Published: October 2016

AbstractIn allen lebenden Zellen bildet die Transkription den ersten Schritt der Expression genetischer Information. Ihrer Regulation unterliegen Zelldifferenzierung, Morphogenese sowie Antworten auf Umweltveränderungen. Während der Transkription verwendet das Enzym RNA‐Polymerase DNA als Vorlage, um eine komplementäre RNA‐Kopie von einem Gen herzustellen. Wir beschreiben die Entwicklungen in unserem strukturellen Verständnis der Transkription in Eukaryoten, die in den letzten 10 Jahren nach der Verleihung des Nobelpreises für Chemie an Roger Kornberg im Jahr 2006 erzielt wurden. Eine Aufklärung der Transkriptionsinitiation und ‐elongation zeichnet sich ab, wohingegen die Mechanismen der Transkriptionsregulation weitgehend unverstanden bleiben. In diesem Feld wurden strukturbiologische Hybridmethoden entwickelt, die verschiedene Techniken zur Bestimmung der dreidimensionalen Architektur von großen und transienten makromolekularen Komplexen kombinieren.