bluuebunny/crossref_metadata_2025_split huggingface dataset:
Global change effects on humid tropical forests: Evidence for biogeochemical and biodiversity shifts at an ecosystem scale
Authors: Cusack Daniela F. , Karpman Jason , Ashdown Daniel , Cao Qian , Ciochina Mark , Halterman Sarah , Lydon Scott , Neupane Avishesh 
Published: July 2016

AbstractGovernment and international agencies have highlighted the need to focus global change research efforts on tropical ecosystems. However, no recent comprehensive review exists synthesizing humid tropical forest responses across global change factors, including warming, decreased precipitation, carbon dioxide fertilization, nitrogen deposition, and land use/land cover changes. This paper assesses research across spatial and temporal scales for the tropics, including modeling, field, and controlled laboratory studies. The review aims to (1) provide a broad understanding of how a suite of global change factors are altering humid tropical forest ecosystem properties and biogeochemical processes; (2) assess spatial variability in responses to global change factors among humid tropical regions; (3) synthesize results from across humid tropical regions to identify emergent trends in ecosystem responses; (4) identify research and management priorities for the humid tropics in the context of global change. Ecosystem responses covered here include plant growth, carbon storage, nutrient cycling, biodiversity, and disturbance regime shifts. The review demonstrates overall negative effects of global change on all ecosystem properties, with the greatest uncertainty and variability in nutrient cycling responses. Generally, all global change factors reviewed, except for carbon dioxide fertilization, demonstrate great potential to trigger positive feedbacks to global warming via greenhouse gas emissions and biogeophysical changes that cause regional warming. This assessment demonstrates that effects of decreased rainfall and deforestation on tropical forests are relatively well understood, whereas the potential effects of warming, carbon dioxide fertilization, nitrogen deposition, and plant species invasions require more cross‐site, mechanistic research to predict tropical forest responses at regional and global scales.
Effects of changes in rock microstructures on permeability: 3‐D printing investigation
Authors: Head D. , Vanorio T. 
Published: July 2016

AbstractRocks are naturally heterogeneous; two rock samples with identical bulk properties can vary widely in microstructure. Understanding how the microstructure and bulk properties of rocks then evolve during experiments and computations simulating diagenesis is inherently a multiscale problem. The advent of modern 3‐D printing has provided an unprecedented opportunity to link those scales by combining the strengths of digital and experimental rock physics. In this study, we take a computerized tomography‐scanned model of a natural carbonate pore space then iteratively digitally manipulate, 3‐D print, and measure the flow properties in the laboratory. This approach allows us to access multiple scales digitally and experimentally and test hypotheses about how changes in rock microstructure due to compaction and dissolution affect bulk transport properties in a repeatable manner.
Response of the equatorial ionosphere to the geomagnetic DP 2 current system
Authors: Yizengaw E. , Moldwin M. B. , Zesta E. , Magoun M. , Pradipta R. , Biouele C. M. , Rabiu A. B. , Obrou O. K. , Bamba Z. , de Paula E. R. 
Published: July 2016

AbstractThe response of equatorial ionosphere to the magnetospheric origin DP 2 current system fluctuations is examined using ground‐based multiinstrument observations. The interaction between the solar wind and magnetosphere generates a convection electric field that can penetrate to the ionosphere and cause the DP 2 current system. The quasiperiodic DP 2 current system, which fluctuates coherently with fluctuations of the interplanetary magnetic field (IMF) Bz, penetrates nearly instantaneously to the dayside equatorial region at all longitudes and modulates the electrodynamics that governs the equatorial density distributions. In this paper, using magnetometers at high and equatorial latitudes, we demonstrate that the quasiperiodic DP 2 current system penetrates to the equator and causes the dayside equatorial electrojet (EEJ) and the independently measured ionospheric drift velocity to fluctuate coherently with the high‐latitude DP 2 current as well as with the IMF Bz component. At the same time, radar observations show that the ionospheric density layers move up and down, causing the density to fluctuate up and down coherently with the EEJ and IMF Bz.
Modeling physical chemistry of the Io plasma torus in two dimensions
Authors: Copper M. , Delamere P. A. , Overcast‐Howe K. 
Published: July 2016

AbstractPeriodicities in the Io plasma illustrate the rich complexity of magnetosphere‐ionosphere coupling in space plasmas. The confounding System IV period (slower than the rotation of Jupiter's magnetic field ≡ System III) remains a mystery of the torus. Common to both System III and IV are modulations of the superthermal electron population. The small fraction (<1%) of hot electrons plays a vital role in torus physical and chemical properties, modulating the abundance and temperature of ion species. Building on previous models of torus physical chemistry, we have developed a two‐dimensional model that includes azimuthal and radial transport (diffusion equation) while averaging chemical processes in latitude. This paper presents initial results of the model, demonstrating the role of hot electrons in forming a single‐peaked torus structure. The effect of azimuthal shear is investigated as plasma is transported radially outward, showing how the torus properties evolve during transport from a chemically dominated regime (inner torus) to a transport dominated regime (outer torus). Surprisingly, we find that hot electron populations influence torus properties at all radial distances. While many of our results are preliminary, suggestions for future modeling experiments are suggested to provide additional insight into the origin of the ubiquitous superthermal electrons.
Right‐hand polarized 4fce auroral roar emissions: 2. Nonlinear generation theory
Authors: Yoon P. H. , LaBelle J. , Weatherwax A. T. 
Published: July 2016

AbstractAuroral roar emissions are commonly interpreted as Z (or upper hybrid) mode naturally excited by precipitating auroral electrons. Subsequent conversion to escaping radiation makes it possible for these emissions to be detected on the ground. Most emissions are detected as having left‐hand (L) circular (or ordinary O) polarization, but the companion paper presents a systematic experimental study on the rare occurrence of the right‐hand polarized, or equivalently, extraordinary (X) mode 4fce emission. A similar observation was reported earlier by Sato et al. (2015). The suggested emission mechanism is the nonlinear coalescence of two upper hybrid roars at 2fce. The present paper formulates a detailed theory for such an emission mechanism.
Impact of seasonality and anthropogenic impoundments on dissolved organic matter dynamics in the Klamath River (Oregon/California, USA)
Authors: Oliver Allison A. , Spencer Robert G. M. , Deas Michael L. , Dahlgren Randy A. 
Published: July 2016

AbstractRivers play a major role in the transport and processing of dissolved organic matter (DOM). Disturbances that impact DOM dynamics, such as river impoundments and flow regulation, have consequences for biogeochemical cycling and aquatic ecosystems. In this study we examined how river impoundments and hydrologic regulation impact DOM quantity and quality by tracking spatial and seasonal patterns of DOM in a large, regulated river (Klamath River, USA). Dissolved organic carbon (DOC) concentrations decreased downstream and longitudinal patterns in DOC load varied by season. Export of DOM (as DOC) was largely driven by river flow, while DOM composition was strongly influenced by impoundments. Seasonal algal blooms in upstream lentic reaches provided a steady source of algal DOM that was processed in downstream reaches. DOM at upstream sites had an average spectral slope ratio (SR) > 1, indicating algal‐derived material, but decreased downstream to an average SR < 1, more indicative of terrestrial‐derived material. The increasingly terrestrial nature of DOM exported from reservoirs likely reflects degraded algal material that becomes increasingly more recalcitrant with distance from upstream source and additional processing. As a result, DOM delivered to free‐flowing river reaches below impoundments was less variable in composition. Downstream of impoundments, tributary influences resulted in increasing contributions of terrestrial DOM from the surrounding watershed. Removal of the four lower dams on the Klamath River is scheduled to proceed in the next decade. These results suggest that management should consider the role of impoundments on altering DOM dynamics, particularly in the context of dam removal.
Enantioselective Copper‐Catalyzed Propargylic Etherification of Propargylic Esters with Phenols Promoted by Inorganic Base Additives
Authors: Shao Long , Zhang De‐Yang , Wang Ya‐Hui , Hu Xiang‐Ping 
Published: July 2016

AbstractAn enantioselective copper‐catalyzed propargylic etherification of both aromatic and aliphatic propargylic esters with phenols has been developed, in which the employment of inorganic base additives, in particular cesium carbonate (Cs2CO3), was found to significantly promote not only the reactivity but also the enantioselectivity of the reaction. By using a structurally hindered chiral ketimine P,N,N‐ligand, a wide range of optically active propargylic ethers were prepared in high yields and with excellent enantioselectivities (up to 98% ee).magnified image
What Consumers Are Looking for in Strawberries: Implications from Market Segmentation Analysis
Authors: Wang Jingjing , Yue Chengyan , Gallardo Karina , McCracken Vicki , Luby James , McFerson Jim 
Published: July 2016

ABSTRACTAn online choice experiment was conducted to investigate U.S. consumer preferences for attributes of fresh market strawberry fruit. Using a latent class logit model, three different groups of consumers are identified: “Balanced Consumers,” “Experience Attribute Sensitive Consumers,” and “Search Attribute Sensitive Consumers.” This information on consumer segmentation can help the fresh market strawberry industry identify target markets, and provides valuable information to breeders, growers, and retailers to prioritize fruit attributes in their breeding, growing, or product sourcing decisions.
Fragmentverknüpfung und ‐optimierung von Hemmstoffen der Aspartylprotease Endothiapepsin: Fragmentbasiertes Wirkstoffdesign beschleunigt durch dynamische kombinatorische Chemie
Authors: Mondal Milon , Radeva Nedyalka , Fanlo‐Virgós Hugo , Otto Sijbren , Klebe Gerhard , Hirsch Anna K. H. 
Published: July 2016

AbstractFragmentbasiertes Wirkstoffdesign (FBWD) führt zu pharmakologisch aktiven Substanzen für biologische Targets. Obschon es zahlreiche Beispiele für FBWD anhand von Fragmentwachstum und ‐optimierung gibt, wird die Verknüpfung von Fragmenten nur selten verwendet. Dynamische kombinatorische Chemie (DKC) ist zu einer erfolgreichen Strategie für die Identifizierung von Hits für biologische Targets herangewachsen. Wir berichten hier über die synergistische Kombination von Fragmentverknüpfung und DKC, um Inhibitoren der Aspartylprotease Endothiapepsin zu identifizieren. Aufbauend auf Röntgenkristallstrukturen von Endothiapepsin im Komplex mit Fragmenten haben wir eine Bibliothek von Bisacylhydrazonen entworfen und DKC benutzt, um potente Hemmstoffe des Enzyms zu identifizieren: Der stärkste Hemmstoff besitzt einen IC50‐Wert von 54 nm, was eine 240‐fache Steigerung der Affinität im Vergleich zu den Ausgangstreffern darstellt. Anschließend hat die Röntgenkristallographie den vorhergesagten Bindungsmodus bestätigt und somit die Effizienz der Kombination aus Fragmentverknüpfung und DKC als Strategie für die Identifizierung von Hits unterstrichen. Die Methode kann für eine Reihe biologischer Targets Anwendung finden und sollte das Potenzial haben, die Optimierung eines Hits zu einer Leitstruktur zu vereinfachen.
Detection of LacZ‐Positive Cells in Living Tissue with Single‐Cell Resolution
Authors: Doura Tomohiro , Kamiya Mako , Obata Fumiaki , Yamaguchi Yoshifumi , Hiyama Takeshi Y. , Matsuda Takashi , Fukamizu Akiyoshi , Noda Masaharu , Miura Masayuki , Urano Yasuteru 
Published: July 2016

AbstractThe LacZ gene, which encodes Escherichia coli β‐galactosidase, is widely used as a marker for cells with targeted gene expression or disruption. However, it has been difficult to detect lacZ‐positive cells in living organisms or tissues at single‐cell resolution, limiting the utility of existing lacZ reporters. Herein we present a newly developed fluorogenic β‐galactosidase substrate suitable for labeling live cells in culture, as well as in living tissues. This precisely functionalized fluorescent probe exhibited dramatic activation of fluorescence upon reaction with the enzyme, remained inside cells by anchoring itself to intracellular proteins, and provided single‐cell resolution. Neurons labeled with this probe preserved spontaneous firing, which was enhanced by application of ligands of receptors expressed in the cells, suggesting that this probe would be applicable to investigate functions of targeted cells in living tissues and organisms.
Precise Modulation of the Breathing Behavior and Pore Surface in Zr‐MOFs by Reversible Post‐Synthetic Variable‐Spacer Installation to Fine‐Tune the Expansion Magnitude and Sorption Properties
Authors: Chen Cheng‐Xia , Wei Zhangwen , Jiang Ji‐Jun , Fan Yan‐Zhong , Zheng Shao‐Ping , Cao Chen‐Chen , Li Yu‐Hao , Fenske Dieter , Su Cheng‐Yong 
Published: July 2016

AbstractTo combine flexibility and modifiability towards a more controllable complexity of MOFs, a post‐synthetic variable‐spacer installation (PVSI) strategy is used to implement kinetic installation/ uninstallation of secondary ligands into/from a robust yet flexible proto‐Zr‐MOF. This PVSI process features precise positioning of spacers with different length, size, number, and functionality, enabling accurate fixation of successive breathing stages and fine‐tuning of pore surface. It shows unprecedented synthetic tailorability to create complicated MOFs in a predictable way for property modification, for example, CO2 and R22 adsorption/separation, thermal/chemical stability, and extended breathing behavior.
Fragment Linking and Optimization of Inhibitors of the Aspartic Protease Endothiapepsin: Fragment‐Based Drug Design Facilitated by Dynamic Combinatorial Chemistry
Authors: Mondal Milon , Radeva Nedyalka , Fanlo‐Virgós Hugo , Otto Sijbren , Klebe Gerhard , Hirsch Anna K. H. 
Published: July 2016

AbstractFragment‐based drug design (FBDD) affords active compounds for biological targets. While there are numerous reports on FBDD by fragment growing/optimization, fragment linking has rarely been reported. Dynamic combinatorial chemistry (DCC) has become a powerful hit‐identification strategy for biological targets. We report the synergistic combination of fragment linking and DCC to identify inhibitors of the aspartic protease endothiapepsin. Based on X‐ray crystal structures of endothiapepsin in complex with fragments, we designed a library of bis‐acylhydrazones and used DCC to identify potent inhibitors. The most potent inhibitor exhibits an IC50 value of 54 nm, which represents a 240‐fold improvement in potency compared to the parent hits. Subsequent X‐ray crystallography validated the predicted binding mode, thus demonstrating the efficiency of the combination of fragment linking and DCC as a hit‐identification strategy. This approach could be applied to a range of biological targets, and holds the potential to facilitate hit‐to‐lead optimization.
Second‐Generation Non‐Covalent NAAA Inhibitors are Protective in a Model of Multiple Sclerosis
Authors: Migliore Marco , Pontis Silvia , Fuentes de Arriba Angel Luis , Realini Natalia , Torrente Esther , Armirotti Andrea , Romeo Elisa , Di Martino Simona , Russo Debora , Pizzirani Daniela , Summa Maria , Lanfranco Massimiliano , Ottonello Giuliana , Busquet Perrine , Jung Kwang‐Mook , Garcia‐Guzman Miguel , Heim Roger , Scarpelli Rita , Piomelli Daniele 
Published: July 2016

AbstractPalmitoylethanolamide (PEA) and oleoylethanolamide (OEA) are endogenous lipid mediators that suppress inflammation. Their actions are terminated by the intracellular cysteine amidase, N‐acylethanolamine acid amidase (NAAA). Even though NAAA may offer a new target for anti‐inflammatory therapy, the lipid‐like structures and reactive warheads of current NAAA inhibitors limit the use of these agents as oral drugs. A series of novel benzothiazole–piperazine derivatives that inhibit NAAA in a potent and selective manner by a non‐covalent mechanism are described. A prototype member of this class (8) displays high oral bioavailability, access to the central nervous system (CNS), and strong activity in a mouse model of multiple sclerosis (MS). This compound exemplifies a second generation of non‐covalent NAAA inhibitors that may be useful in the treatment of MS and other chronic CNS disorders.
Selective Synthesis of Partially Protected Nonsymmetric Biphenols by Reagent‐ and Metal‐Free Anodic Cross‐Coupling Reaction
Authors: Wiebe Anton , Schollmeyer Dieter , Dyballa Katrin M. , Franke Robert , Waldvogel Siegfried R. 
Published: July 2016

AbstractThe oxidative cross‐coupling of aromatic substrates without the necessity of leaving groups or catalysts is described. The selective formation of partially protected nonsymmetric 2,2′‐biphenols via electroorganic synthesis was accomplished with a high yield of isolated product. Since electric current is employed as the terminal oxidant, the reaction is reagent‐free; no reagent waste is generated as only electrons are involved. The reaction is conducted in an undivided cell, and is suitable for scale‐up and inherently safe. The implementation of O‐silyl‐protected phenols in this transformation results in both significantly enhanced yields and higher selectivity for the desired nonsymmetric 2,2′‐biphenols. The use of a bulky silyl group to block one hydroxyl moiety makes the final product less prone to oxidation. Furthermore, the partially silyl‐protected 2,2′‐biphenols are versatile building blocks that usually require tedious or low‐yielding synthetic pathways. Additionally, this strategy facilitates a large variety of new substrate combinations for oxidative cross‐coupling reactions.
Stereoselective β‐Mannosylation by Neighboring‐Group Participation
Authors: Elferink Hidde , Mensink Rens A. , White Paul B. , Boltje Thomas J. 
Published: July 2016

AbstractThe stereoselective synthesis of glycosidic bonds is the main challenge of oligosaccharide synthesis. Neighboring‐group participation (NGP) of C2 acyl substituents can be used to provide 1,2‐trans‐glycosides. Recently, the application of NGP has been extended to the preparation of 1,2‐cis‐glycosides with the advent of C2 chiral auxiliaries. However, this methodology has been strictly limited to the synthesis of 1,2‐cis‐gluco‐type sugars. Reported herein is the design and synthesis of novel mannosyl donors which provide 1,2‐cis‐mannosides by NGP of thioether auxiliaries. A key element in the design is the use of 1C4 locked mannuronic acid lactones to enable NGP of the C2 auxiliary. In addition to C2 participation a new mode of remote participation of the C4 benzyl group was identified and provides 1,2‐cis‐mannosides.
Highly Efficient Access to Both Geometric Isomers of Silyl Enol Ethers: Sequential 1,2‐Brook/Wittig Reactions
Authors: Matsuya Yuji , Wada Kentaro , Minato Daishiro , Sugimoto Kenji 
Published: July 2016

AbstractNovel sequential 1,2‐Brook/Wittig reactions were developed for the preparation of silyl enol ethers. This method enables highly selective preparation of both geometric isomers of glyoxylate silyl enol ethers, using aldehydes (E‐selective) and tosylimines (Z‐selective) as a Wittig electrophile. The salt‐free conditions of this reaction system are likely to be advantageous for switching the selectivity. The optimal reaction conditions and generality of the reaction were investigated, and plausible explanations for the observed selectivity were also discussed.
Determination of the minimum sample size for a reliable strength measurement of talc‐filled polypropylene fibers
Authors: Nohut S. , Tascan M. 
Published: July 2016

ABSTRACTAccurate determination of mechanical properties plays an important role to comment on improvement in the mechanical properties of particle‐filled PP fibers. However, the existing standards are not totally suitable for reliable strength determination of particle‐filled PP fibers. In the framework of this study, microsized talc particle‐filled PP fibers were produced with different talc ratio and tensile strength measurements were performed with various gage lengths. Statistical Akaike Information Criterion analysis shows that strength distribution of talc‐filled PP fibers is best characterized by Weibull distribution function. It is reported that, the gage length has almost no influence of Weibull parameters of pure PP fibers while strong effects on Weibull parameters of talc‐filled PP fibers. It is shown that if the tensile strength of talc‐filled PP fibers is to be measured, at least 50 samples, which is more than value suggested by existing standard, should be used for a reliable determination of Weibull parameters. Therefore, the main aim of this study is to question the feasibility of minimum sample size suggested by the existing ASTM D3822 standard for reliable strength measurement of talc filled PP fibers. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44083.
Functionalized galactoglucomannan‐based hydrogels for the removal of metal cations from aqueous solutions
Authors: Elgueta Elizabeth , Sánchez Julio , Dax Daniel , Xu Chunlin , Willför Stefan , Rivas Bernabé L , González Marianela 
Published: July 2016

ABSTRACTNew types of hydrogels derived from O‐acetyl galactoglucomannan (AcGGM) hemicellulose have been synthesized and characterized. The objective of this work was to analyze the sorption capacity (S) of three types of hydrogels containing AcGGM derivatives incorporated into the carboxylic groups of the polymer chain in the AA hydrogel, sulfonic groups in the APA hydrogel, and amide groups in the acrylamide (Aam) hydrogel. These hydrogels are capable of interacting and removing ions such as cadmium [Cd(II)], copper [Cu(II)], lead [Pb(II)], nickel [Ni(II)], and zinc [Zn(II)]. The results show that AA and Aam hydrogels had a lower sorption capacity of ions compared to the APA hydrogel, which had a high sorption capacity. The maximal sorption capacity was determined by the successive enrichment method, obtaining Pb(II) amount of 48.3 mg/g of AA hydrogel, 65.8 mg/g of APA hydrogel, and 40.8 mg/g of Aam hydrogel. Hence, Pb(II) ions are greatly retained by the three hydrogels. These results are promising for the development of new materials with potential applications in metal ion removal. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44093.