bluuebunny/crossref_metadata_2025_split huggingface dataset:
Future change in ocean productivity: Is the Arctic the new Atlantic?
Authors: Yool A. , Popova E. E. , Coward A. C. 
Published: October 2015

AbstractOne of the most characteristic features in ocean productivity is the North Atlantic spring bloom. Responding to seasonal increases in irradiance and stratification, surface phytopopulations rise significantly, a pattern that visibly tracks poleward into summer. While blooms also occur in the Arctic Ocean, they are constrained by the sea‐ice and strong vertical stratification that characterize this region. However, Arctic sea‐ice is currently declining, and forecasts suggest this may lead to completely ice‐free summers by the mid‐21st century. Such change may open the Arctic up to Atlantic‐style spring blooms, and do so at the same time as Atlantic productivity is threatened by climate change‐driven ocean stratification. Here we use low and high‐resolution instances of a coupled ocean‐biogeochemistry model, NEMO‐MEDUSA, to investigate productivity. Drivers of present‐day patterns are identified, and changes in these across a climate change scenario (IPCC RCP 8.5) are analyzed. We find a globally significant decline in North Atlantic productivity (> −20%) by 2100, and a correspondingly significant rise in the Arctic (> +50%). However, rather than the future Arctic coming to resemble the current Atlantic, both regions are instead transitioning to a common, low nutrient regime. The North Pacific provides a counterexample where nutrients remain high and productivity increases with elevated temperature. These responses to climate change in the Atlantic and Arctic are common between model resolutions, suggesting an independence from resolution for key impacts. However, some responses, such as those in the North Pacific, differ between the simulations, suggesting the reverse and supporting the drive to more fine‐scale resolutions.
Walking Speed As a Potential Indicator of Cartilage Breakdown Following Anterior Cruciate Ligament Reconstruction
Authors: Pietrosimone Brian , Troy Blackburn J. , Harkey Matthew S. , Luc Brittney A. , Hackney Anthony C. , Padua Darin A. , Driban Jeffrey B. , Spang Jeffrey T. , Jordan Joanne M. 
Published: October 2015

ObjectiveTo determine whether or not self‐selected walking speed associates with serum biomarkers of cartilage (collagen and proteoglycan) breakdown in anterior cruciate ligament reconstructed (ACLR) individuals.MethodsTwenty individuals with a history of a primary unilateral ACLR participated in this cross‐sectional study. Resting blood was collected from each participant prior to completing 5 walking gait trials at a self‐selected comfortable speed. Walking speed was evaluated in a 3‐dimensional motion capture laboratory and determined from the velocity of the pelvic center of mass. Sera were assessed for collagen type II cleavage product (C2C) and proteoglycan (aggrecan) concentrations using commercially available specific enzyme‐linked immunosorbent assays. Pearson's product‐moment (r) and Spearman's (ρ) correlations were used to evaluate associations between walking speed and biomarkers of cartilage breakdown metabolism. Partial correlations were used to determine whether covariates influenced associations between walking speed and biomarkers of cartilage breakdown.ResultsACLR individuals with a slower walking speed demonstrated higher concentrations of serum C2C (r = −0.52, P = 0.02), while there was no significant association between walking speed and aggrecan concentrations (ρ = −0.29, P = 0.31). After accounting for the variance associated with stance phase duration, ACLR individuals with a slower walking speed still demonstrated greater serum C2C concentrations (partial r = −0.53, P = 0.02).ConclusionACLR individuals who habitually walk slower may experience a greater degree of collagen breakdown, suggesting that walking speed may be a future useful clinical indicator for identifying individuals with higher levels of cartilage breakdown and preradiographic osteoarthritic joint changes.
An adaptive digital filter for noise attenuation in sampled control systems
Authors: Kennedy Hugh L. 
Published: October 2015

SummaryA recursive smoothing filter employing a bank of fading‐memory polynomial sub‐filters is presented. Variance estimates are used to mix the outputs of the sub‐filters, imparting variable gain and phase characteristics that permit it to automatically adapt to signal parameter changes. The proposed adaptive technique does not involve the estimation of plant parameters; therefore, it may be used in both open‐loop and closed‐loop configurations. In open‐loop estimation problems, variable gain/bandwidth allows it to reduce the impact of random errors caused by sensor noise and the impact of bias errors caused by model mismatch during ‘maneuvers’. In feedback control problems, variable phase/delay allows it to act as a lag filter for an improved steady‐state response (i.e. greater noise attenuation) and act as a lead filter, or a proportional‐derivative controller, for an improved transient response (i.e. increased closed‐loop damping) for input discontinuities. Copyright © 2015 John Wiley & Sons, Ltd.
A Robust Infinite Zirconium Phenolate Building Unit to Enhance the Chemical Stability of Zr MOFs
Authors: Mouchaham Georges , Cooper Lucy , Guillou Nathalie , Martineau Charlotte , Elkaïm Erik , Bourrelly Sandrine , Llewellyn Philip L. , Allain Clémence , Clavier Gilles , Serre Christian , Devic Thomas 
Published: October 2015

AbstractA novel Zr‐chain based MOF, namely MIL‐163, was designed and successfully synthesized using a bis‐1,2,3‐trioxobenzene ligand. Endowed with large square‐shaped channels of 12 Å width, it shows remarkable water uptake (ca. 0.6 cm3 g−1 at saturating vapor pressure) and a remarkable stability in simulated physiological media, where archetypical Zr carboxylate MOFs readily degrade.
The Trifluoromethyl Anion
Authors: Lishchynskyi Anton , Miloserdov Fedor M. , Martin Eddy , Benet‐Buchholz Jordi , Escudero‐Adán Eduardo C. , Konovalov Andrey I. , Grushin Vladimir V. 
Published: October 2015

AbstractFirst evidence for the existence of free trifluoromethyl anion CF3− has been obtained. The 3D‐caged potassium cation in [K(crypt‐222)]+ is inaccessible to CF3−, thus rendering it uncoordinated (“naked”). Ionic [K(crypt‐222)]+ CF3− has been characterized by single‐crystal X‐ray diffraction, solution NMR spectroscopy, DFT calculations, and reactivity toward electrophiles.
The Role of Follicular Helper T Cell Molecules and Environmental Influences in Autoantibody Production and Progression to Inflammatory Arthritis in Mice
Authors: Chevalier Nina , Macia Laurence , Tan Jian K. , Mason Linda J. , Robert Remy , Thorburn Alison N. , Wong Connie H. Y. , Tsai Louis M. , Bourne Katherine , Brink Robert , Yu Di , Mackay Charles R. 
Published: October 2015

ObjectiveAntibody‐mediated autoimmunity involves cognate interactions between self‐reactive T cells and B cells during germinal center (GC) reactions. The aim of this study was to determine the role of essential follicular helper T (Tfh) cell molecules (CXCR5, signaling lymphocytic activation molecule–associated protein) on autoreactive CD4+ cells and the role of certain environmental influences that may determine GC‐driven autoantibody production and arthritis development.MethodsWe transferred self‐reactive CD4+ cells from KRN‐Tg mice into recipient mice, which induced autoantibodies and autoinflammatory arthritis. This model allowed manipulation of environmental effects, such as inflammation, and use of transferred cells that were genetically deficient in important Tfh cell–associated molecules.ResultsA deficiency of signaling lymphocytic activation molecule–associated protein (SAP) in CD4+ cells from KRN‐Tg mice completely protected against arthritis, indicating that stable T cell–B cell interactions are required for GC formation, autoantibody production, and arthritis induction. In contrast, a CXCR5 deficiency in CD4+ cells from KRN‐Tg mice still induced disease when these cells were transferred into wild‐type mice, suggesting that T cell help for B cells could rely on other migration mechanisms. However, various manipulations influenced this system, including elimination of bystander effects through use of CD28−/− recipient mice (reduced disease) or use of inflammation‐inducing Freund's complete adjuvant (progression to arthritis). We also examined the capacity of preexisting GCs with a nonautoimmune specificity to co‐opt autoimmune T cells and observed no evidence for any influence.ConclusionIn addition to the quality and quantity of cognate CD4+ cell help, external factors such as inflammation and noncognate CD4+ cell bystander activation trigger autoimmunity by shaping events within autoimmune GC responses. SAP is an essential molecule for autoimmune antibody production, whereas the importance of CXCR5 varies depending on the circumstances.
Modeling and verification of process parameters for the production of tannase by Aspergillus oryzae under submerged fermentation using agro‐wastes
Authors: Varadharajan Venkatramanan , Vadivel Sudhan Shanmuga , Ramaswamy Arulvel , Sundharamurthy Venkatesaprabhu , Chandrasekar Priyadharshini 
Published: October 2015

AbstractTannase production by Aspergillus oryzae using various agro‐wastes as substrates by submerged fermentation was studied in this research. The microbe was isolated from degrading corn kernel obtained from the corn fields at Tiruchengode, India. The microbial identification was done using 18S rRNA gene analysis. The agro‐wastes chosen for the study were pomegranate rind, Cassia auriculata flower, black gram husk, and tea dust. The process parameters chosen for optimization study were substrate concentration, pH, temperature, and incubation period. During one variable at a time optimization, the pomegranate rind extract produced maximum tannase activity of 138.12 IU/mL and it was chosen as the best substrate for further experiments. The quadratic model was found to be the effective model for prediction of tannase production by A. oryzae. The optimized conditions predicted by response surface methodology (RSM) with genetic algorithm (GA) were 1.996% substrate concentration, pH of 4.89, temperature of 34.91 °C, and an incubation time of 70.65 H with maximum tannase activity of 138.363 IU/mL. The confirmatory experiment under optimized conditions showed tannase activity of 139.22 IU/mL. Hence, RSM‐GA pair was successfully used in this study to optimize the process parameters required for the production of tannase using pomegranate rind.
Active‐Metal Template Synthesis of a Halogen‐Bonding Rotaxane for Anion Recognition
Authors: Langton Matthew J. , Xiong Yaoyao , Beer Paul D. 
Published: October 2015

AbstractThe synthesis of an all‐halogen‐bonding rotaxane for anion recognition is achieved by using active‐metal templation. A flexible bis‐iodotriazole‐containing macrocycle is exploited for the metal‐directed rotaxane synthesis. Endotopic binding of a CuI template facilitates an active‐metal CuAAC iodotriazole axle formation reaction that captures the interlocked rotaxane product. Following copper‐template removal, exotopic coordination of a more sterically demanding rhenium(I) complex induces an inversion in the conformation of the macrocycle component, directing the iodotriazole halogen‐bond donors into the rotaxane’s interlocked binding cavity to facilitate anion recognition.
Stereoselective Behavior of the Chiral Herbicides Diclofop‐Methyl and Diclofop During the Soy Sauce Brewing Process
Authors: Lu Yuele , Zhang Dong , Liao Yahui , Diao Jinling , Chen Xiaolong 
Published: October 2015

AbstractChiral pesticides are now receiving more and more attention in the food‐making process. This experiment studied the enantioselective behavior of diclofop‐methyl (DM) and its main metabolite, diclofop (DC), during the soy sauce brewing process. Two kinds of commonly used strains, Aspergillus oryzae and Saccharomyces rouxii, were investigated. However, they showed a different degradation ability to the enantiomers of DM and DC. It was observed that (–)‐(S)‐DM was degraded much faster than (+)‐(R)‐DM by Saccharomyces rouxii, while no stereoselective degradation was found by Aspergillus oryzae. DC represented a relatively long residue period in this fermentation process and both strains showed a weak degradation ability to DC, especially Saccharomyces rouxii. There was little DC detected in the final product, while most of the DC residues persisted in the lees, which were usually used as animal feeds or discarded into the environment directly as waste. Therefore, more attention should be paid to the soy sauce brewing process concerning pesticide residues both in the final product and byproducts. Chirality 28:78–84, 2016. © 2015 Wiley Periodicals, Inc.
Schreiben im Chemieunterricht
Authors: Beerenwinkel Anne , Hefti Claudia , Lindauer Thomas , Schmellentin Claudia 
Published: October 2015

AbstractEpistemisches Schreiben gilt als ein wichtiges Mittel zur Unterstützung des Verstehensprozesses und der Erkenntnisgewinnung: Beim Schreiben werden Gedanken geklärt und weiterentwickelt. Zudem wird das fachliche Verstehen für die Lehrperson sichtbar. Sein Potenzial für das Lernen im Chemieunterricht ist bislang allerdings wenig ausgeschöpft und nur unzureichend erforscht. Um Schreiben im Chemieunterricht produktiv für das Lernen der Schüler und Schülerinnen nutzbar zu machen, müssen bestimmte Bedingungen beachtet werden. Diese werden im Beitrag diskutiert. Dazu wird zunächst nach der Bedeutung des epistemischen Schreibens für den Lernprozess im Chemieunterricht gefragt. Anschließend werden Anregungen gegeben, wie Schreiben durch kleine Aufträge und mittels didaktischer Strukturierung in den Chemieunterricht integriert werden könnte.
The importance of analyzing neighbor competitive response in the target–neighbor experimental design
Authors: Barry Kevin J. , Dudash Michele R. 
Published: October 2015

AbstractThe role of competition in community structure and species interactions is universal. However, how one quantifies the outcome of competitive interactions is frequently debated. Here, we review the strengths and weaknesses of the target–neighbor design, a type of additive design where one of the competing species is reduced to a single individual and where controls and analyses are used for the target, but not for the neighbors. We conducted a literature review to determine how the target–neighbor design has been typically used and analyzed. We found that historically, targets were often smaller than neighbors and introduced after neighbor establishment; thus, targets would have little effect on neighbors. However, as co‐establishment of targets and neighbors of similar size is now common, the target is more likely to affect the neighbors than in its earlier usage. This can be problematic, because if targets have a significant effect on neighbor performance, bias is introduced into the assessment of the target results. As target treatment controls are necessary to determine the absolute effect of neighbors on target growth, we advocate that analysis of the neighbor competitive response serves as a necessary control for unexpected target x neighbor interactions.
Synthesis and Structural Analysis of 1,4,7,10‐Tetraazacyclododecane‐1,4,7,10‐­tetraazidoethylacetic Acid (DOTAZA) Complexes
Authors: Kriemen Ella , Holzapfel Malte , Ruf Erik , Rehbein Julia , Maison Wolfgang 
Published: October 2015

AbstractHerein, we present the synthesis and structural analysis of metal complexes of enantiomerically pure 1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetraazidoethylacetic acid (DOTAZA). DOTAZA is a new tunable analog of DOTA, a clinically approved chelator for various pharmaceutically relevant metal ions. In this work, we investigate the complexation chemistry of DOTAZA and report the crystal structures of a number of complexes with pharmaceutically relevant metal ions such as Gd3+ [magnetic resonance imaging (MRI)], Eu3+ (luminescence spectroscopy), Y3+ [positron emission tomography (PET)], In3+ [single‐photon‐emission computed tomography (SPECT)], and Na+. These structures provide useful information for imaging applications and demonstrate the potential of DOTAZA to form stable complexes. Owing to its clickable azide functionalities, it may be used for the development of tailored imaging reagents that retain the positive complexation chemistry of the parent compound DOTA.
Synthesis of PtIV‐Biomolecule Conjugates through Click Chemistry
Authors: Gabano Elisabetta , Ravera Mauro , Tinello Stefano , Osella Domenico 
Published: October 2015

AbstractThe azide‐functionalized PtIV complex {(OC‐6–34)‐chlorido(cyclobutane‐1,1′‐dicarboxylato)(cyclohexane‐1R,2R‐diamine)[2‐hydroxyethyl(2‐{2‐[2‐(2‐azidoethoxy)ethoxy]ethoxy}ethyl)carbamate]platinum(IV)} was synthesized and characterized to obtain a starting complex that was suitable for coupling with appropriate biological carriers in a drug targeting and delivery strategy. The following click reaction (CuI‐catalyzed Huisgen cycloaddition, CuAAC) was successfully applied for coupling with three different model biomolecules that can be exploited for selective targeting of the platinum conjugate toward tumor cells; i.e., the amino acid alanine and the dipeptide lysine‐alanine, both previously alkyne‐functionalized with pent‐4‐ynoic acid, and the hormone 17α‐ethynylestradiol. The title complex demonstrated very good compatibility with both CuAAC reaction and solid‐phase peptide synthesis conditions, making it a suitable antiproliferative fragment for the design of nanovectors.
Metal‐Catalyzed Cross‐Coupling Reactions of Aminopyridines
Authors: Dias Pires Marina J. , Poeira Diogo L. , Marques M. Manuel B. 
Published: October 2015

AbstractThe aminopyridines are key building blocks in the synthesis of bioactive heterocyclic compounds such as azaindoles and imidazopyridines. The role of metal‐catalyzed methods in aminopyridine functionalization, in particular the catalytic systems used, reaction conditions and the influence of aminopyridine substituents on the reaction outcome, is outlined. The review covers different metal‐catalyzed reactions developed for C–C and C–N bond formation. One‐pot and multicomponent reactions directed towards aminopyridine‐based heterocyclic compounds are also covered. Besides cross‐coupling reactions, other reactions involving metal catalysts, such as C–H activation and oxidative cyclization, are also reported. The idea is to give the reader an overview of the challenges and limitations of the use of metal‐catalyzed synthesis for aminopyridine functionalization in order to make a useful contribution to chemists working in organic synthesis field.
Isolation and Total Synthesis of Albu­peptins A–D: 11‐Residue Peptaibols from the Fungus Gliocladium album
Authors: Otto Alexander , Laub Annegret , Porzel Andrea , Schmidt Jürgen , Wessjohann Ludger , Westermann Bernhard , Arnold Norbert 
Published: October 2015

AbstractFour new 11‐mer peptaibols, named albupeptins A–D (1–4), were isolated from cultures of the fungus Gliocladium album. Their structures were elucidated on the basis of 1D and 2D NMR spectroscopy, as well as ESI‐HRMSn analysis. The sequence of albupeptin A (1) was thus identified as Ac‐Aib1‐Aib2‐Val3‐Leu4‐Aib5‐Pro6‐Iva7‐Leu8‐Gln9‐Aib10‐Leuol11. Albupeptins B (2) and C (3) feature an exchange of Aib5 by Iva5 and of Aib1 by Iva1, respectively, and albupeptin D (4) contains both Iva1 and Iva5 residues. The stereochemistry of the isolated peptaibols 1–4 was unambiguously assigned by 1H NMR chemical shift analysis in conjunction with solid‐phase peptide synthesis. By using this approach, the absolute configuration of the Iva residues in albupeptins A (1) and C (3) was determined to be D, whereas albupeptins B (2) and D (4) feature an additional Iva5 residue with an L configuration. Thus, albupeptins B (2) and D (4) belong to the rare class of peptaibols that have both stereoisomers of Iva in the same sequence.
Shale gas in North America and Europe
Authors: Stephenson Michael H. 
Published: October 2015

AbstractAccording to the U.S. Energy Information Administration, shale gas will provide half of the United States’ domestic gas by 2035. The United States has already moved from being one of the world's largest importers of gas to being self‐sufficient in less than a decade, bringing hundreds of thousands of jobs and attracting back companies that long ago left America in search of cheap manufacturing costs. But the increase in shale gas extraction has also had an environmental cost. There is clear scientific evidence of leaking shale gas wells and induced earthquakes, and in some areas a population increasingly turning against the industry. The technology of horizontal drilling and hydraulic fracturing that was developed in the United States is now being tried outside the United States, including in Europe, Argentina, and China. There are clear reasons why shale gas might be attractive to Europe. It may offer security of energy supply to some countries particularly dependent on Russian gas; it could stimulate growth and jobs; and it could supply a cleaner fuel than coal in power stations. However, prospective shale often underlies areas of high population density in Europe, and moreover, populations that are unfamiliar with onshore gas operations. The main challenge in Europe therefore is not mainly technological but for the industry to achieve a “social license” and for Government and regulations to be manifestly protecting the public and property.
Heston‐Type Stochastic Volatility with a Markov Switching Regime
Authors: Elliott Robert J. , Nishide Katsumasa , Osakwe Carlton‐James U. 
Published: October 2015

AbstractWe construct a Heston‐type stochastic volatility model with a Markov switching regime to price a plain‐vanilla stock option. A semi‐analytic solution, which contains a matrix ODE is obtained and numerically calculated. Our model is flexible enough to provide a wide variety of volatility surfaces for the same volatility level but different regimes. © 2015 Wiley Periodicals, Inc. Jrl Fut Mark 36:902–919, 2016