bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimating error cross‐correlations in soil moisture data sets using extended collocation analysis
Authors: Gruber A. , Su C.‐H. , Crow W. T. , Zwieback S. , Dorigo W. A. , Wagner W. 
Published: January 2016

AbstractGlobal soil moisture records are essential for studying the role of hydrologic processes within the larger earth system. Various studies have shown the benefit of assimilating satellite‐based soil moisture data into water balance models or merging multisource soil moisture retrievals into a unified data set. However, this requires an appropriate parameterization of the error structures of the underlying data sets. While triple collocation (TC) analysis has been widely recognized as a powerful tool for estimating random error variances of coarse‐resolution soil moisture data sets, the estimation of error cross covariances remains an unresolved challenge. Here we propose a method—referred to as extended collocation (EC) analysis—for estimating error cross‐correlations by generalizing the TC method to an arbitrary number of data sets and relaxing the therein made assumption of zero error cross‐correlation for certain data set combinations. A synthetic experiment shows that EC analysis is able to reliably recover true error cross‐correlation levels. Applied to real soil moisture retrievals from Advanced Microwave Scanning Radiometer‐EOS (AMSR‐E) C‐band and X‐band observations together with advanced scatterometer (ASCAT) retrievals, modeled data from Global Land Data Assimilation System (GLDAS)‐Noah and in situ measurements drawn from the International Soil Moisture Network, EC yields reasonable and strong nonzero error cross‐correlations between the two AMSR‐E products. Against expectation, nonzero error cross‐correlations are also found between ASCAT and AMSR‐E. We conclude that the proposed EC method represents an important step toward a fully parameterized error covariance matrix for coarse‐resolution soil moisture data sets, which is vital for any rigorous data assimilation framework or data merging scheme.
Adaptive sliding mode observation in a network of dynamical systems
Authors: Menon Prathyush P. , Edwards Christopher , Shtessel Yuri B. 
Published: January 2016

SummaryThis paper considers the problem of reconstructing state information in all the nodes of a complex network of dynamical systems. The individual nodes comprise a known linear part and unknown but bounded uncertainties in certain channels of the system. A supervisory adaptive sliding mode observer configuration is proposed for estimating the states. A linear matrix inequality (LMI) approach is suggested to synthesise the gains of the sliding mode observer. Although deployed centrally to estimate all the states of the complex network, the design process depends only on the dynamics of an individual node of the network. The methodology is demonstrated by considering a network of Chua oscillators. Copyright © 2016 John Wiley & Sons, Ltd.
Food mechanical properties and dietary ecology
Authors: Berthaume Michael A. 
Published: January 2016

AbstractInterdisciplinary research has benefitted the fields of anthropology and engineering for decades: a classic example being the application of material science to the field of feeding biomechanics. However, after decades of research, discordances have developed in how mechanical properties are defined, measured, calculated, and used due to disharmonies between and within fields. This is highlighted by “toughness,” or energy release rate, the comparison of incomparable tests (i.e., the scissors and wedge tests), and the comparison of incomparable metrics (i.e., the stress and displacement‐limited indices). Furthermore, while material scientists report on a myriad of mechanical properties, it is common for feeding biomechanics studies to report on just one (energy release rate) or two (energy release rate and Young's modulus), which may or may not be the most appropriate for understanding feeding mechanics. Here, I review portions of materials science important to feeding biomechanists, discussing some of the basic assumptions, tests, and measurements. Next, I provide an overview of what is mechanically important during feeding, and discuss the application of mechanical property tests to feeding biomechanics. I also explain how 1) toughness measures gathered with the scissors, wedge, razor, and/or punch and die tests on non‐linearly elastic brittle materials are not mechanical properties, 2) scissors and wedge tests are not comparable and 3) the stress and displacement‐limited indices are not comparable. Finally, I discuss what data gathered thus far can be best used for, and discuss the future of the field, urging researchers to challenge underlying assumptions in currently used methods to gain a better understanding between primate masticatory morphology and diet. Am J Phys Anthropol 159:S79–S104, 2016. © 2016 Wiley Periodicals, Inc.
Bone morphologies and histories: Life course approaches in bioarchaeology
Authors: Agarwal Sabrina C. 
Published: January 2016

ABSTRACTThe duality of the skeleton as both a biological and cultural entity has formed the theoretical basis of bioarchaeology. In recent years bioarchaeological studies have stretched the early biocultural concept with the adoption of life course approaches in their study design and analyses, making a significant contribution to how we think about the role of postnatal plasticity. Life course theory is a conceptual framework used in several scientific fields of biology and the social sciences. Studies that emphasize life course approaches in the examination of bone morphology in the past are united in their interrogation of human life as a result of interrelated and cumulative events over not only the timeframe of individuals, but also over generations at the community level. This article provides an overview of the theoretical constructs that utilize the life course concept, and a discussion of the different ways these theories have been applied to thinking about trajectories of bone morphology in the past, specifically highlighting key recent studies that have used life course approaches to understand the influence of growth, stress, diet, activity, and aging on the skeleton. The goal of this article is to demonstrate the scope of contemporary bioarchaeological studies that illuminate the importance of environmental and behavioral influence on bone morphology. Understanding how trajectories of bone growth and morphology can be altered and shaped over the life course is critical not only for bioarchaeologists, but also researchers studying bone morphology in living nonhuman primates and fossil primate skeletons. Am J Phys Anthropol 159:S130–S149, 2016. © 2016 American Association of Physical Anthropologists
Does the primate pattern hold up? Testing the functional significance of infraorbital foramen size variation among marsupials
Authors: Spriggs Amanda N. , Muchlinski Magdalena N. , Gordon Adam D. 
Published: January 2016

ABSTRACTObjectivesThe relative size of the infraorbital foramen (IOF) has been used to infer the ecology of extinct primates for several decades. Primates have relatively smaller IOFs than most other mammals, which may result from the fact that they pre‐process and manipulate food with their hands rather than their muzzles. In primates, relative IOF area co‐varies with diet, where insectivores and folivores have relatively smaller IOFs than frugivores. We wanted to determine whether the observed patterns associated with IOF variation hold across other orders.Materials and MethodsWe examined how relative IOF area differs among marsupials occupying different ecological niches. Marsupials were chosen because they converge with primates in both ecology and morphology, but unlike primates, some marsupials approach and pre‐process foods only with their muzzles. We measured IOF area and cranial lengths from 72 marsupial species, and behavioral feeding data were obtained from a subset of this sample (N = 20).ResultsRelative IOF area did not vary significantly between substrate preferences. However, relative IOF area differed significantly by diet category (P < 0.001). Species that specialize in feeding on non‐grassy leaves have significantly smaller relative IOF areas than species which primarily feed on grasses, insects, vertebrates, or some combination thereof. Behavioral analyses support that folivorous marsupials approach and remove food with the hands more often than marsupials from other dietary groups.DiscussionResults suggest that relatively small IOF area may reflect increased reliance on the hands while feeding, and that relative IOF size can be used as an indicator of feeding behavior. Am J Phys Anthropol 160:30–40, 2016. © 2016 Wiley Periodicals, Inc.
Antarlides: A New Type of Androgen Receptor (AR) Antagonist that Overcomes Resistance to AR‐Targeted Therapy
Authors: Saito Shun , Fujimaki Takahiro , Panbangred Watanalai , Igarashi Yasuhiro , Imoto Masaya 
Published: January 2016

AbstractProstate cancer is treated with androgen receptor (AR) antagonists but most patients experience disease progression after long‐term treatment with these compounds. Therefore, new AR antagonists are required for patient follow‐up treatment. In the course of screening for a new AR antagonist, we isolated the novel compounds antarlides A–E (1–5) from Streptomyces sp. BB47. Antarlides are mutually isomeric with respect to the double bond and have a 22‐membered‐ring macrocyclic structure. The full stereostructure of 1 was established by chemical modifications, including methanolysis, the Trost method, acetonide formation, and the PGME method. 1–5 inhibited the binding of androgen to ARs in vitro. In addition, 2 inhibited the transcriptional activity of not only wild‐type AR but also mutant ARs, which are seen in patients with acquired resistance to clinically used AR antagonists. Therefore, antarlides are a potent new generation of AR antagonists that overcome resistance.
Mechanochromism and Mechanical‐Force‐Triggered Cross‐Linking from a Single Reactive Moiety Incorporated into Polymer Chains
Authors: Zhang Huan , Gao Fei , Cao Xiaodong , Li Yanqun , Xu Yuanze , Weng Wengui , Boulatov Roman 
Published: January 2016

AbstractIncorporation of small reactive moieties, the reactivity of which depends on externally imposed load (so‐called mechanophores) into polymer chains offers access to a broad range of stress‐responsive materials. Here, we report that polymers incorporating spirothiopyran (STP) manifest both green mechanochromism and load‐induced addition reactions in solution and solid. Stretching a macromolecule containing colorless STP converts it into green thiomerocyanine (TMC), the mechanically activated thiolate moiety of which undergoes rapid thiol–ene click reactions with certain reactive C=C bonds to form a graft or a cross‐link. The unique dual mechanochemical response of STP makes it of potentially great utility both for the design of new stress‐responsive materials and for fundamental studies in polymer physics, for example, the dynamics of physical and mechanochemical remodeling of loaded materials.
Photoresponsive Formation of an Intermolecular Minimal G‐Quadruplex Motif
Authors: Thevarpadam Julie , Bessi Irene , Binas Oliver , Gonçalves Diana P. N. , Slavov Chavdar , Jonker Hendrik R. A. , Richter Christian , Wachtveitl Josef , Schwalbe Harald , Heckel Alexander 
Published: January 2016

AbstractThe ability of three different bifunctional azobenzene linkers to enable the photoreversible formation of a defined intermolecular two‐tetrad G‐quadruplex upon UV/Vis irradiation was investigated. Circular dichroism and NMR spectroscopic data showed the formation of G‐quadruplexes with K+ ions at room temperature in all three cases with the corresponding azobenzene linker in an E conformation. However, only the para–para‐substituted azobenzene derivative enables photoswitching between a nonpolymorphic, stacked, tetramolecular G‐quadruplex and an unstructured state after E–Z isomerization.
Basenfreie katalytische asymmetrische C‐C‐Kupplung mit terminalen Inamiden als effizienter Zugang zu multifunktionellen Trifluormethylalkoholen
Authors: Cook Andrea M. , Wolf Christian 
Published: January 2016

AbstractDie asymmetrische Addition terminaler Inamide an Trifluormethylketone mit einem leicht zugänglichem chiralen Zink‐Katalysator ergibt CF3‐substituierte tertiäre Propargylalkohole mit bis zu 99 % Ausbeute und 96 % ee. Der Ausschluss von organischen Zinkadditiven und Basen sowie der Nutzen der Produkte für Synthesen sind besondere Merkmale dieser Reaktion. Der Wert der β‐Hydroxy‐β‐trifluormethylinamide ist exemplarisch mit ausgewählten Umwandlungen zu chiralen Z‐ und E‐Enamiden, einem Amid und N,O‐Ketenacetalen belegt. Die äußerst regioselektive Hydratisierung, stereoselektive Reduktionen und Hydroacyloxylierungen erfolgen mit hohen Ausbeuten und ohne Erosion des ee der verwendeten β‐Hydroxyinamide.
Spurlose Synthese von asymmetrisch modifizierten, bivalenten Nukleosomen
Authors: Lechner Carolin C. , Agashe Ninad D. , Fierz Beat 
Published: January 2016

AbstractKombinationen verschiedener posttranslationaler Modifikationen (PTMs) von Histon‐Proteinen haben einen direkten Einfluss auf die epigenetische Genregulation. Obwohl Histone paarweise in Nukleosomen vorliegen, sind die individuellen Histonvarianten nicht zwangsläufig gleich modifiziert, sondern weisen oftmals unterschiedliche PTMs auf (sie sind “asymmetrisch”). Insbesondere in embryonalen Stammzellen (ESCs) existiert eine “bivalente” Chromatinsignatur, gekennzeichnet durch die Koexistenz von H3, entweder trimethyliert an Lysin 4 (H3K4me3) oder 27 (H3K27me3) im gleichen Nukleosom. Wir beschreiben hier ein generell anwendbares und modulares Verfahren zur Herstellung von asymmetrisch modifizierten Nukleosomen. Mittels dieser Methode können wir darlegen, dass die H3K27‐spezifische Lysin‐Methyltransferase (KMT) Polycomb Repressive Complex 2 (PRC2) in bivalenten Nukleosomen durch H3K4me3 inhibiert wird, allerdings nur solange sich die PTM auf demselben H3‐Molekül befindet. Im Gegensatz dazu stimuliert die Anwesenheit von H3K27me3 die Aktivität von PRC2 über das gesamte Nukleosom, und hebt den hemmenden Effekt von H3K4me3 auf. Um in ESCs eine bivalente Chromatinsignatur zu erhalten, muss folglich die Aktivität von PRC2 entweder lokal eingeschränkt oder gar aktiv rückgängig gemacht werden.
Cobalt‐Catalyzed Annulation of Salicylaldehydes and Alkynes to Form Chromones and 4‐Chromanones
Authors: Yang Junfeng , Yoshikai Naohiko 
Published: January 2016

AbstractA unique cobalt(I)–diphosphine catalytic system has been identified for the coupling of salicylaldehyde (SA) and an internal alkyne affording a dehydrogenative annulation product (chromone) or a reductive annulation product (4‐chromanone) depending on the alkyne substituents. Distinct from related rhodium(I)‐ and rhodium(III)‐catalyzed reactions of SA and alkynes, these annulation reactions feature aldehyde C−H oxidative addition of SA and subsequent hydrometalation of the C=O bond of another SA molecule as common key steps. The reductive annulation to 4‐chromanones also involves the action of Zn as a stoichiometric reductant. In addition to these mechanistic features, the CoI catalysis described herein is complementary to the RhI‐ and RhIII‐catalyzed reactions of SA and internal alkynes, particularly in the context of chromone synthesis.
Stretch‐Induced Drug Delivery from Superhydrophobic Polymer Composites: Use of Crack Propagation Failure Modes for Controlling Release Rates
Authors: Wang Julia , Kaplan Jonah A. , Colson Yolonda L. , Grinstaff Mark W. 
Published: January 2016

AbstractThe concept of using crack propagation in polymeric materials to control drug release and its first demonstration are reported. The composite drug delivery system consists of highly‐textured superhydrophobic electrosprayed microparticle coatings, composed of biodegradable and biocompatible polymers poly(caprolactone) and poly(glycerol monostearate carbonate‐co‐caprolactone), and a cellulose/polyester core. The release of entrapped agents is controlled by the magnitude of applied strain, resulting in a graded response from water infiltration through the propagating patterned cracks in the coating. Strain‐dependent delivery of the anticancer agents cisplatin and 7‐ethyl‐10‐hydroxycamptothecin to esophageal cancer cells (OE33) in vitro is observed. Finally the device is integrated with an esophageal stent to demonstrate delivery of fluorescein diacetate, using applied tension, to an ex vivo esophagus.
Nickel‐Catalyzed Activation of Acyl C−O Bonds of Methyl Esters
Authors: Hie Liana , Fine Nathel Noah F. , Hong Xin , Yang Yun‐Fang , Houk Kendall N. , Garg Neil K. 
Published: January 2016

AbstractWe report the first catalytic method for activating the acyl C−O bonds of methyl esters through an oxidative‐addition process. The oxidative‐addition adducts, formed using nickel catalysis, undergo in situ trapping to provide anilide products. DFT calculations are used to support the proposed reaction mechanism, to understand why decarbonylation does not occur competitively, and to elucidate the beneficial role of the substrate structure and the Al(OtBu)3 additive on the kinetics and thermodynamics of the reaction.
Elastic Organic Crystals of a Fluorescent π‐Conjugated Molecule
Authors: Hayashi Shotaro , Koizumi Toshio 
Published: January 2016

AbstractAn elastic organic crystal of a π‐conjugated molecule has been fabricated. A large fluorescent single crystal of 1,4‐bis[2‐(4‐methylthienyl)]‐2,3,5,6‐tetrafluorobenzene (over 1 cm long) exhibited a fibril lamella morphology based on slip‐stacked molecular wires, and it was found to be a remarkably elastic crystalline material. The straight crystal was capable of bending more than 180° under applied stress and then quickly reverted to its original shape upon relaxation. In addition, the fluorescence quantum yield of the crystal was about twice that of the compound in THF solution. Mechanical bending–relaxation resulted in reversible change of the morphology and fluorescence. This research offers a more general approach to flexible crystals as a promising new family of organic semiconducting materials.
Near‐IR Emitting Iridium(III) Complexes with Heteroaromatic β‐Diketonate Ancillary Ligands for Efficient Solution‐Processed OLEDs: Structure–Property Correlations
Authors: Kesarkar Sagar , Mróz Wojciech , Penconi Marta , Pasini Mariacecilia , Destri Silvia , Cazzaniga Marco , Ceresoli Davide , Mussini Patrizia R. , Baldoli Clara , Giovanella Umberto , Bossi Alberto 
Published: January 2016

AbstractThree NIR‐emitting neutral IrIII complexes [Ir(iqbt)2(dpm)] (1), [Ir(iqbt)2(tta)] (2), and [Ir(iqbt)2(dtdk)] (3) based on the 1‐(benzo[b]thiophen‐2‐yl)‐isoquinolinate (iqtb) were synthesized and characterized (dpm=2,2,6,6‐tetramethyl‐3,5‐heptanedionate; tta=2‐thienoyltrifluoroacetonate; dtdk=1,3‐di(thiophen‐2‐yl)propane‐1,3‐dionate). The compounds emit between λ=680 and 850 nm with high luminescence quantum yields (up to 16 %). By combining electrochemistry, photophysical measurements, and computational modelling, the relationship between the structure, energy levels, and properties were investigated. NIR‐emitting, solution‐processed phosphorescent organic light‐emitting devices (PHOLEDs) were fabricated using the complexes. The devices show remarkable external quantum efficiencies (above 3 % with 1) with negligible efficiency roll‐off values, exceeding the highest reported values for solution‐processible NIR emitters.
Copolymerization of Ethylene and Polar Monomers by Using Ni/IzQO Catalysts
Authors: Tao Wen‐jie , Nakano Ryo , Ito Shingo , Nozaki Kyoko 
Published: January 2016

AbstractThe replacement of precious metals in catalysis by earth‐abundant metals is currently one of the urgent challenges for chemists. Whereas palladium‐catalyzed copolymerization of ethylene and polar monomers is a valuable method for the straightforward synthesis of functionalized polyolefins, the corresponding nickel‐based catalysts have suffered from poor thermal tolerance and low molecular weight of the polymers formed. Herein, we report a series of neutral nickel complexes bearing imidazo[1,5‐a]quinolin‐9‐olate‐1‐ylidene (IzQO) ligands. The Ni/IzQO system can catalyze ethylene polymerization at 50–100 °C with reasonable activity in the absence of any cocatalyst, whereas most known nickel‐based catalysts are deactivated at this temperature range. The Ni/IzQO catalyst was successfully applied to the copolymerization of ethylene with allyl monomers to obtain the corresponding copolymers with the highest molecular weight reported for a Ni‐catalyzed system.
Chromatographic NMR Spectroscopy with Hollow Silica Spheres
Authors: González‐García Tania , Margola Tommaso , Silvagni Adriano , Mancin Fabrizio , Rastrelli Federico 
Published: January 2016

AbstractThe use of micrometric hollow silica spheres is described as a strategy to reduce magnetic field inhomogeneities in the context of NMR chromatography. When employed as a stationary phase, hollow silica microspheres allow the use of common solution‐state NMR instruments to measure the diffusion coefficient perturbation induced by the interaction of the analytes with the silica surface.
Breast Cancer Stem Cell Potent Copper(II)–Non‐Steroidal Anti‐Inflammatory Drug Complexes
Authors: Boodram Janine N. , Mcgregor Iain J. , Bruno Peter M. , Cressey Paul B. , Hemann Michael T. , Suntharalingam Kogularamanan 
Published: January 2016

AbstractThe breast cancer stem cell (CSC) potency of a series of copper(II)–phenanthroline complexes containing the nonsteroidal anti‐inflammatory drug (NSAID), indomethacin, is reported. The most effective copper(II) complex in this series, 4, selectivity kills breast CSC‐enriched HMLER‐shEcad cells over breast CSC‐depleted HMLER cells. Furthermore, 4 reduces the formation, size, and viability of mammospheres, to a greater extent than salinomycin, a potassium ionophore known to selectively inhibit CSCs. Mechanistic studies revealed that the CSC‐specificity observed for 4 arises from its ability to generate intracellular reactive oxygen species (ROS) and inhibit cyclooxygenase‐2 (COX‐2), an enzyme that is overexpressed in breast CSCs. The former induces DNA damage, activates JNK and p38 pathways, and leads to apoptosis.
Efficient Access to Multifunctional Trifluoromethyl Alcohols through Base‐Free Catalytic Asymmetric C−C Bond Formation with Terminal Ynamides
Authors: Cook Andrea M. , Wolf Christian 
Published: January 2016

AbstractThe asymmetric addition of terminal ynamides to trifluoromethyl ketones with a readily available chiral zinc catalyst gives CF3‐substituted tertiary propargylic alcohols in up to 99 % yield and 96 % ee. The exclusion of organozinc additives and base as well as the general synthetic utility of the products are key features of this reaction. The value of the β‐hydroxy‐β‐trifluoromethyl ynamides is exemplified by selective transformations to chiral Z‐ and E‐enamides, an amide, and N,O‐ketene acetals. The highly regioselective hydration, stereoselective reduction, and hydroacyloxylation reactions proceed with high yields and without erosion of the ee value of the parent β‐hydroxy ynamides.
A Diradical Approach towards BODIPY‐Based Dyes with Intense Near‐Infrared Absorption around λ=1100 nm
Authors: Ni Yong , Lee Sangsu , Son Minjung , Aratani Naoki , Ishida Masatoshi , Samanta Animesh , Yamada Hiroko , Chang Young‐Tae , Furuta Hiroyuki , Kim Dongho , Wu Jishan 
Published: January 2016

AbstractA diradical approach to obtain stable organic dyes with intense absorption around λ=1100 nm is reported. The para‐ and meta‐quinodimethane‐bridged BODIPY dimers BD‐1 and BD‐2 were synthesized and were found to have a small amount of diradical character. These molecules exhibited very intense absorption at λ=1088 nm (ɛ=6.65×105 M−1 cm−1) and 1136 nm (ɛ=6.44×105 M−1 cm−1), respectively, together with large two‐photon‐absorption cross‐sections. Structural isomerization induced little variation in their diradical character but distinctive differences in their physical properties. Moreover, the compounds showed a selective fluorescence turn‐on response in the presence of the hydroxyl radical but not with other reactive oxygen species.