bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving a global model from the boundary layer: Total turbulent energy and the neutral limit Prandtl number
Authors: Pithan Felix , Angevine Wayne , Mauritsen Thorsten 
Published: May 2015

AbstractModel intercomparisons have identified important deficits in the representation of the stable boundary layer by turbulence parametrizations used in current weather and climate models. However, detrimental impacts of more realistic schemes on the large‐scale flow have hindered progress in this area. Here we implement a total turbulent energy scheme into the climate model ECHAM6. The total turbulent energy scheme considers the effects of Earth's rotation and static stability on the turbulence length scale. In contrast to the previously used turbulence scheme, the TTE scheme also implicitly represents entrainment flux in a dry convective boundary layer. Reducing the previously exaggerated surface drag in stable boundary layers indeed causes an increase in southern hemispheric zonal winds and large‐scale pressure gradients beyond observed values. These biases can be largely removed by increasing the parametrized orographic drag. Reducing the neutral limit turbulent Prandtl number warms and moistens low‐latitude boundary layers and acts to reduce longstanding radiation biases in the stratocumulus regions, the Southern Ocean and the equatorial cold tongue that are common to many climate models.
Seeing the landscape for the trees: Metrics to guide riparian shade management in river catchments
Authors: Johnson Matthew F. , Wilby Robert L. 
Published: May 2015

AbstractRising water temperature (Tw) due to anthropogenic climate change may have serious consequences for river ecosystems. Conservation and/or expansion of riparian shade could counter warming and buy time for ecosystems to adapt. However, sensitivity of river reaches to direct solar radiation is highly heterogeneous in space and time, so benefits of shading are also expected to be site specific. We use a network of high‐resolution temperature measurements from two upland rivers in the UK, in conjunction with topographic shade modeling, to assess the relative significance of landscape and riparian shade to the thermal behavior of river reaches. Trees occupy 7% of the study catchments (comparable with the UK national average) yet shade covers 52% of the area and is concentrated along river corridors. Riparian shade is most beneficial for managing Tw at distances 5–20 km downstream from the source of the rivers where discharge is modest, flow is dominated by near‐surface hydrological pathways, there is a wide floodplain with little landscape shade, and where cumulative solar exposure times are sufficient to affect Tw. For the rivers studied, we find that approximately 0.5 km of complete shade is necessary to off‐set Tw by 1°C during July (the month with peak Tw) at a headwater site; whereas 1.1 km of shade is required 25 km downstream. Further research is needed to assess the integrated effect of future changes in air temperature, sunshine duration, direct solar radiation, and downward diffuse radiation on Tw to help tree planting schemes achieve intended outcomes.
The dynamic effects of sea level rise on low‐gradient coastal landscapes: A review
Authors: Passeri Davina L. , Hagen Scott C. , Medeiros Stephen C. , Bilskie Matthew V. , Alizad Karim , Wang Dingbao 
Published: May 2015

AbstractCoastal responses to sea level rise (SLR) include inundation of wetlands, increased shoreline erosion, and increased flooding during storm events. Hydrodynamic parameters such as tidal ranges, tidal prisms, tidal asymmetries, increased flooding depths and inundation extents during storm events respond nonadditively to SLR. Coastal morphology continually adapts toward equilibrium as sea levels rise, inducing changes in the landscape. Marshes may struggle to keep pace with SLR and rely on sediment accumulation and the availability of suitable uplands for migration. Whether hydrodynamic, morphologic, or ecologic, the impacts of SLR are interrelated. To plan for changes under future sea levels, coastal managers need information and data regarding the potential effects of SLR to make informed decisions for managing human and natural communities. This review examines previous studies that have accounted for the dynamic, nonlinear responses of hydrodynamics, coastal morphology, and marsh ecology to SLR by implementing more complex approaches rather than the simplistic “bathtub” approach. These studies provide an improved understanding of the dynamic effects of SLR on coastal environments and contribute to an overall paradigm shift in how coastal scientists and engineers approach modeling the effects of SLR, transitioning away from implementing the “bathtub” approach. However, it is recommended that future studies implement a synergetic approach that integrates the dynamic interactions between physical and ecological environments to better predict the impacts of SLR on coastal systems.
Distinct patterns of microbial metabolism associated to riverine dissolved organic carbon of different source and quality
Authors: Berggren Martin , del Giorgio Paul A. 
Published: May 2015

AbstractDissolved organic carbon (DOC) in rivers contains a wide range of molecules that can be assimilated by microbes. However, there is today no integrated understanding of how the source and composition of this DOC regulate the extent to which the DOC can support microbial growth and respiration. We analyzed patterns in microbial metabolism of DOC from different streams and rivers in Québec, by combining short‐term bacterial production and respiration measurements with long‐term DOC loss and analyses of bacterial use of different single substrates. We show that distinct metabolic patterns indeed exist across catchments, reflecting the varying nature and sources of the DOC. For example, DOC from forest headwaters systematically supported the highest bacterial growth efficiency (BGE) that was recorded, while in contrast DOC in peat bog drainage was used with significantly lower BGE. The carbon consumption in clear mountain rivers, possibly represented by autochthonous algal DOC, supported the highest bacterial respiration rates and the highest long‐term DOC losses. By using principle component analysis, we demonstrate how the major axes of variation in all of the measured metabolic responses are tightly connected to spectrofluorometrical DOC composition indicators and to isotopic indicators of DOC source. If causality is assumed, our results imply that changes in DOC supply from different sources, for example, caused by land use or climate change, should result in dramatic changes in the patterns of aquatic microbial metabolism and thus in altered aquatic ecosystem functioning, with likely consequences for food‐web structures and greenhouse gas balances.
A randomized controlled trial of exercise in spinal and bulbar muscular atrophy
Authors: Shrader Joseph A. , Kats Ilona , Kokkinis Angela , Zampieri Cris , Levy Ellen , Joe Galen O. , Woolstenhulme Joshua G. , Drinkard Bart E. , Smith Michaele R. , Ching Willie , Ghosh Laboni , Fox Derrick , Auh Sungyoung , Schindler Alice B. , Fischbeck Kenneth H. , Grunseich Christopher 
Published: May 2015

AbstractObjectiveTo determine the safety and efficacy of a home‐based functional exercise program in spinal and bulbar muscular atrophy (SBMA).MethodsSubjects were randomly assigned to participate in 12 weeks of either functional exercises (intervention) or a stretching program (control) at the National Institutes of Health in Bethesda, MD. A total of 54 subjects enrolled, and 50 completed the study with 24 in the functional exercise group and 26 in the stretching control group. The primary outcome measure was the Adult Myopathy Assessment Tool (AMAT) total score, and secondary measures included total activity by accelerometry, muscle strength, balance, timed up and go, sit‐to‐stand test, health‐related quality of life, creatine kinase, and insulin‐like growth factor‐1.ResultsFunctional exercise was well tolerated but did not lead to significant group differences in the primary outcome measure or any of the secondary measures. The functional exercise did not produce significantly more adverse events than stretching, and was not perceived to be difficult. To determine whether a subset of the subjects may have benefited, we divided them into high and low functioning based on baseline AMAT scores and performed a post hoc subgroup analysis. Low‐functioning individuals receiving the intervention increased AMAT functional subscale scores compared to the control group.InterpretationAlthough these trial results indicate that functional exercise had no significant effect on total AMAT scores or on mobility, strength, balance, and quality of life, post hoc findings indicate that low‐functioning men with SBMA may respond better to functional exercises, and this warrants further investigation with appropriate exercise intensity.
Depression and anxiety in chronic rhinosinusitis
Authors: Tomoum Mohamed O. , Klattcromwell Cristine , DelSignore Anthony , Ebert Charles , Senior Brent A. 
Published: May 2015

BackgroundBoth depression and anxiety have been suspected to impact quality of life adversely in patients with chronic rhinosinusitis (CRS). The objective of this work was to assess for the presence of anxiety and/or depression in the setting of CRS and to assess their impact on disease‐related quality of life by analyzing the correlation between the Rhinosinusitis Disability Index (RSDI) and the Hospital Anxiety and Depression score (HADS), as well as the Lund‐Kennedy nasal endoscopic scores.MethodsA total of 124 patients with CRS were prospectively evaluated in the outpatient setting using the RSDI and HADS questionnaires as well as the Lund‐Kennedy nasal endoscopy scoring system.ResultsThe total RSDI and its subscale scores had moderate to very strong correlation with the HADS total score and each of its subscale scores in comparison to their poor correlation with Lund‐Kennedy endoscopic score. CRS patients with depression or anxiety scores 8 to 10 (possible case of clinically significant depression or anxiety) and 11 to 21 (probable case) reported worse total RSDI and subscale scores when compared with those with normal scores (0 to 7). There was no significant difference in the Lund‐Kennedy endoscopic scores between the different groups of anxiety and depression scores.ConclusionDepression and anxiety are prevalent in CRS. The total RSDI and its different subscale scores exhibit moderate to very strong correlation with depression/anxiety scores as determined by HADS, whereas poor correlation was seen with the Lund‐Kennedy endoscopic score.
Sniffin’ Sticks and olfactory system imaging in patients with Kallmann syndrome
Authors: Ottaviano Giancarlo , Cantone Elena , D'Errico Arianna , Salvalaggio Alessandro , Citton Valentina , Scarpa Bruno , Favaro Angela , Sinisi Antonio Agostino , Liuzzi Raffaele , Bonanni Guglielmo , Di Salle Francesco , Elefante Andrea , Manara Renzo , Staffieri Alberto , Martini Alessandro , Brunetti Arturo 
Published: May 2015

BackgroundThe relationship between olfactory function, rhinencephalon and forebrain changes in Kallmann syndrome (KS) have not been adequately investigated. We evaluated a large cohort of male KS patients using Sniffin’ Sticks and MRI in order to study olfactory bulb (OB) volume, olfactory sulcus (OS) depth, cortical thickness close to the OS, and olfactory phenotype.MethodsOlfaction was assessed administering Sniffin’ Sticks®, in 38 KS patients and 17 controls (by means of Screening 12 test®). All subjects underwent magnetic resonance imaging (MRI) to study OB volume, sulcus depth, and cortical thickness.ResultsCompared to controls, KS patients showed smaller OB volume (p<0.0001), reduced sulcus depth (p<0.0001), and thicker cortex in the region close to the OS (p<0.0001). Anosmic KS patients had smaller OB than controls and hyposmic KS patients; there was no difference between hyposmic KS patients and controls. OB volume correlated with Sniffin’ Sticks score (r = 0.64; p < 0.001), OS depth (p<0.0001) and, inversely, with cortical thickness changes (p<0.0001). Sniffin’ Sticks showed an inverse correlation with cortical thickness (r = −0.5; p<0.0001) and a trend toward a statistically significant correlation with OS depth.ConclusionThe present study provides further evidence of the strict relationship between olfaction and OB volume. The strong correlation between OB volume and the overlying cortical changes highlights the key role of rhinencephalon in forebrain embryogenesis.
Catenane: fünfzig Jahre molekulare Verschlingungen
Authors: Gil‐Ramírez Guzmán , Leigh David A. , Stephens Alexander J. 
Published: May 2015

AbstractEin halbes Jahrhundert nach der ersten gerichteten Synthese eines [2]Catenans durch Schill und Lüttringhaus existiert heutzutage eine Vielzahl an Strategien zur Synthese von Hopf‐Verschlingungen (einfach verzahnten Ringen), der einfachsten Klasse der Catenane. Die Präzision und Effektivität, mit der geeignete Template und/oder nichtkovalente Wechselwirkungen Bausteine anordnen können, ermöglichten die Synthese komplizierter – und häufig schöner – verzahnter Systeme höherer Ordnung, darunter Salomonische Verschlingungen, Borromäische Ringe und ein Davidstern‐Catenan. In diesem Aufsatz werden die zahlreichen Strategien, die im 21. Jahrhundert zur Synthese von Catenanen zur Verfügung stehen, vorgestellt und potenzielle Anwendungen untersucht. Des Weiteren werden die Herausforderungen bei der Synthese noch komplizierterer Topologien aufgezeigt.
Zu den stabilisierenden Effekten in Carbengoldkomplexen
Authors: Nunes dos Santos Comprido Laura , Klein Johannes E. M. N. , Knizia Gerald , Kästner Johannes , Hashmi A. Stephen K. 
Published: May 2015

AbstractDie Bindungsverhältnisse und stabilisierenden Effekte in Carbengoldkomplexen werden mittels Dichtefunktionaltheorie (DFT) und intrinsischen Bindungsorbitalen (IBO) untersucht. Die π‐stabilisierenden Einflüsse organischer Substituenten auf das goldkoordinierte Carben‐Kohlenstoffatom werden für eine Reihe von kürzlich isolierten und charakterisierten Komplexen berechnet, ebenso wie für Zwischenstufen prototypischer 1,6‐Enin‐Cyclisierungen. Die Ergebnisse zeigen die Wichtigkeit dieser Effekte für Goldkomplexe, insbesondere aufgrund des niedrigen π‐Rückbindungsbeitrags des Goldatoms.
Far‐Red and Near‐IR AIE‐Active Fluorescent Organic Nanoprobes with Enhanced Tumor‐Targeting Efficacy: Shape‐Specific Effects
Authors: Shao Andong , Xie Yongshu , Zhu Shaojia , Guo Zhiqian , Zhu Shiqin , Guo Jin , Shi Ping , James Tony D. , Tian He , Zhu Wei‐Hong 
Published: May 2015

AbstractThe rational design of high‐performance fluorescent materials for cancer targeting in vivo is still challenging. A unique molecular design strategy is presented that involves tailoring aggregation‐induced emission (AIE)‐active organic molecules to realize preferable far‐red and NIR fluorescence, well‐controlled morphology (from rod‐like to spherical), and also tumor‐targeted bioimaging. The shape‐tailored organic quinoline–malononitrile (QM) nanoprobes are biocompatible and highly desirable for cell‐tracking applications. Impressively, the spherical shape of QM‐5 nanoaggregates exhibits excellent tumor‐targeted bioimaging performance after intravenously injection into mice, but not the rod‐like aggregates of QM‐2.
Photoelectrocyclization as an Activation Mechanism for Organelle‐Specific Live‐Cell Imaging Probes
Authors: Tran Mai N. , Chenoweth David M. 
Published: May 2015

AbstractPhotoactivatable fluorophores are useful tools in live‐cell imaging owing to their potential for precise spatial and temporal control. In this report, a new photoactivatable organelle‐specific live‐cell imaging probe based on a 6π electrocyclization/oxidation mechanism is described. It is shown that this new probe is water‐soluble, non‐cytotoxic, cell‐permeable, and useful for mitochondrial imaging. The probe displays large Stokes shifts in both pre‐activated and activated forms, allowing simultaneous use with common dyes and fluorescent proteins. Sequential single‐cell activation experiments in dense cellular environments demonstrate high spatial precision and utility in single‐ or multi‐cell labeling experiments.
Inhibition of Ras Signaling by Blocking Ras–Effector Interactions with Cyclic Peptides
Authors: Upadhyaya Punit , Qian Ziqing , Selner Nicholas G. , Clippinger Sarah R. , Wu Zhengrong , Briesewitz Roger , Pei Dehua 
Published: May 2015

AbstractRas genes are frequently activated in human cancers, but the mutant Ras proteins remain largely “undruggable” through the conventional small‐molecule approach owing to the absence of any obvious binding pockets on their surfaces. By screening a combinatorial peptide library, followed by structure–activity relationship (SAR) analysis, we discovered a family of cyclic peptides possessing both Ras‐binding and cell‐penetrating properties. These cell‐permeable cyclic peptides inhibit Ras signaling by binding to Ras‐GTP and blocking its interaction with downstream proteins and they induce apoptosis of cancer cells. Our results demonstrate the feasibility of developing cyclic peptides for the inhibition of intracellular protein–protein interactions and of direct Ras inhibitors as a novel class of anticancer agents.
Catalytic Asymmetric Synthesis of Phosphine Boronates
Authors: Hornillos Valentín , Vila Carlos , Otten Edwin , Feringa Ben L. 
Published: May 2015

AbstractThe first catalytic enantioselective synthesis of ambiphilic phosphine boronate esters is presented. The asymmetric boration of α,β‐unsaturated phosphine oxides catalyzed by a copper bisphosphine complex affords optically active organoboronate esters that bear a vicinal phosphine oxide group in good yields and high enantiomeric excess. The synthetic utility of the products is demonstrated through stereospecific transformations into multifunctional optically active compounds.
Catenanes: Fifty Years of Molecular Links
Authors: Gil‐Ramírez Guzmán , Leigh David A. , Stephens Alexander J. 
Published: May 2015

AbstractHalf a century after Schill and Lüttringhaus carried out the first directed synthesis of a [2]catenane, a plethora of strategies now exist for the construction of molecular Hopf links (singly interlocked rings), the simplest type of catenane. The precision and effectiveness with which suitable templates and/or noncovalent interactions can arrange building blocks has also enabled the synthesis of intricate and often beautiful higher order interlocked systems, including Solomon links, Borromean rings, and a Star of David catenane. This Review outlines the diverse strategies that exist for synthesizing catenanes in the 21st century and examines their emerging applications and the challenges that still exist for the synthesis of more complex topologies.
From Carbanions to Organometallic Compounds: Quantification of Metal Ion Effects on Nucleophilic Reactivities
Authors: Corral‐Bautista Francisco , Klier Lydia , Knochel Paul , Mayr Herbert 
Published: May 2015

AbstractThe influence of the metal on the nucleophilic reactivities of indenyl metal compounds was quantitatively determined by kinetic investigations of their reactions with benzhydrylium ions (Ar2CH+) and structurally related quinone methides. With the correlation equation log k2=sN(N+E), it can be derived that the ionic indenyl alkali compounds are 1018 to 1024 times more reactive (depending on the reference electrophile) than the corresponding indenyltrimethylsilane.
Instantaneous Hydrolysis of Nerve‐Agent Simulants with a Six‐Connected Zirconium‐Based Metal–Organic Framework
Authors: Moon Su‐Young , Liu Yangyang , Hupp Joseph T. , Farha Omar K. 
Published: May 2015

AbstractA nerve‐agent simulant based on a phosphate ester is hydrolyzed using a MOF‐based catalyst. Suspensions of MOF‐808 (6‐connected), a material featuring 6‐connected zirconium nodes, display the highest hydrolysis rates among all MOFs that have been reported to date. A plug‐flow reactor was also prepared with MOF‐808 (6‐connected) as the active layer. Deployed in a simple filtration scheme, the reactor displayed high hydrolysis efficiency and reusability.
Ultrathin Spinel‐Structured Nanosheets Rich in Oxygen Deficiencies for Enhanced Electrocatalytic Water Oxidation
Authors: Bao Jian , Zhang Xiaodong , Fan Bo , Zhang Jiajia , Zhou Min , Yang Wenlong , Hu Xin , Wang Hui , Pan Bicai , Xie Yi 
Published: May 2015

AbstractElectrochemical water splitting is a clean technology for H2 fuels, but greatly hindered by the slow kinetics of the oxygen evolution reaction (OER). Herein, a series of spinel‐structured nanosheets with oxygen deficiencies and ultrathin thicknesses were designed to increase the reactivity and the number of active sites of the catalysts, which were then taken as an excellent platform for promoting the water oxidation process. Theoretical investigations showed that the oxygen vacancies confined in the ultrathin nanosheet could lower the adsorption energy of H2O, leading to increased OER efficiency. As expected, the NiCo2O4 ultrathin nanosheets rich in oxygen vacancies exhibited a large current density of 285 mA cm−2 at 0.8 V and a small overpotential of 0.32 V, both of which are superior to the corresponding values of bulk samples or samples with few oxygen deficiencies and even higher than those of most reported non‐precious‐metal catalysts. This work should provide a new pathway for the design of advanced OER catalysts.
Concerted Ring Opening and Cycloaddition of Chiral Epoxy Enolsilanes with Dienes
Authors: Krenske Elizabeth H. , Lam Sarah , Ng Jerome P. L. , Lo Brian , Lam Sze Kui , Chiu Pauline , Houk Kendall N. 
Published: May 2015

AbstractSilyl‐triflate‐catalyzed (4+3) cycloadditions of epoxy enolsilanes with dienes provide a mild and chemoselective synthetic route to seven‐membered carbocycles. Epoxy enolsilanes containing a terminal enolsilane and a single stereocenter undergo cycloaddition with almost complete conservation of enantiomeric purity, a finding that argues against the involvement of oxyallyl cation intermediates which have been previously proposed for these types of reactions. Reported are theoretical and experimental investigations of the cycloaddition mechanism. The major enantiomers of the cycloadducts are derived from SN2‐like reactions of the silylated epoxide with the diene, in which stereospecific ring opening and formation of the two new CC bonds occur in a single step. Calculations predict, and experiments confirm, that the observed small losses of enantiomeric purity are traced to a triflate‐mediated double SN2 cycloaddition pathway.