bluuebunny/crossref_metadata_2025_split huggingface dataset:
The role of mineral aerosols in shaping the regional climate of West Africa
Authors: Marcella Marc P. , Eltahir Elfatih A. B. 
Published: November 2013

AbstractThis article examines the role of mineral aerosols in the regional climate of West Africa. Analysis is completed by comparing two 30 year simulations using a regional climate model (RegCM3‐IBIS). The two simulations are identical in structure except one includes the representation of mineral aerosols via a fully coupled radiatively interactive dust emissions and aerosol tracer model; the other simulation does not. To discern the impact of dust on West Africa's climate, comparisons are made between the two simulations' surface climatology as well as atmospheric dynamics. It is found that RegCM3‐IBIS and its dust model perform well in simulating the temporal and spatial distributions of mineral aerosols over the Sahel and Sahara. Consistent with previous studies over the region, RegCM3‐IBIS simulates high‐dust loading over the region (aerosol optical depth of 0.5–1.1), which results in significant incident shortwave radiation attenuation (25–50 W/m2) and temperature cooling (0.5°C–1.25°C). Depending on the underlying surface brightness, the top of atmosphere net radiative forcing may be positive (bright desert surfaces) or negative (dark, vegetated surface) with important implications on surface temperature cooling. Here it is proposed that the effects of dust on West African rainfall are distinctly different across the ocean‐land border and the desert border region of the Sahel/Sahara. Nevertheless, in both regions, the change in rainfall is less than 10% of the total annual values. Therefore, this work concludes that the current, observed, dust loading over West Africa does not significantly affect rainfall via changes in the radiation budget. However, it is important to note that this work does not include mineral aerosol effects on sea surface temperatures, which may be significant in influencing the results.
Environmental controls over methane emissions from bromeliad phytotelmata: The role of phosphorus and nitrogen availability, temperature, and water content
Authors: Kotowska Martyna M. , Werner Florian A. 
Published: November 2013

AbstractTank bromeliads are common epiphytic plants throughout neotropical forests that store significant amounts of water in phytotelmata (tanks) formed by highly modified leafs. Methanogenic archaea in these tanks have recently been identified as a significant source of atmospheric methane. We address the effects of environmental drivers (temperature, tank water content, sodium phosphate [P], and urea [N] addition) on methane production in anaerobically incubated bromeliad slurry and emissions from intact bromeliad tanks in montane Ecuador. N addition ≥ 1 mg g−1 had a significantly positive effect on headspace methane concentrations in incubation jars while P addition did not affect methane production at any dosage (≤ 1 mg g−1). Tank bromeliads (Tillandsia complanata) cultivated in situ showed significantly increased effluxes of methane in response to the addition of 26 mg N addition per tank but not to lower dosage of N or any dosage of P (≤ 5.2 mg plant−1). There was no significant interaction between N and P addition. The brevity of the stimulatory effect of N addition on plant methane effluxes (1–2 days) points at N competition by other microorganisms or bromeliads. Methane efflux from plants closely followed within‐day temperature fluctuations over 24 h cycles, yet the dependency of temperature was not exponential as typical for terrestrial wetlands but instead linear. In simulated drought, methane emission from bromeliad tanks was maintained with minimum amounts of water and regained after a short lag phase of approximately 24 h. Our results suggest that methanogens in bromeliads are primarily limited by N and that direct effects of global change (increasing temperature and seasonality, remote fertilization) on bromeliad methane emissions are of moderate scale.
Redistribution of forest carbon caused by patch blowdowns in subalpine forests of the Southern Rocky Mountains, USA
Authors: Wohl Ellen 
Published: November 2013

AbstractPatch blowdowns varying in size from 0.1 to 33 ha affected several areas in Rocky Mountain National Park, Colorado, USA, during the winter of 2011–2012. These blowdowns resulted in substantial redistribution of forest carbon by snapping and uprooting trees, thereby increasing instream wood recruitment, recruitment of dead wood to the forest floor, and exposure of organic soil on uprooted tree plates. Estimates of carbon redistribution at five sites in Rocky Mountain National Park range as high as 308 Mg C/ha in high‐severity patches to 106 Mg C/ha in low‐severity patches, of which typically 10–30% is soil C and the remainder is downed wood. Masses of carbon redistributed from living to dead biomass at high‐severity sites represent a substantial portion of average total biomass in old‐growth subalpine forests in the region. Consequently, the potential for increasing frequency and/or severity of blowdowns under a warming climate represents a significant potential source of terrestrial carbon to the atmosphere. The majority of this carbon is in the form of downed wood that becomes a carbon source to the atmosphere, although interactions between downed wood and river processes can locally increase carbon storage in floodplain soil. Predictions of changes in precipitation and wind patterns, and associated changes in wildfire and insect infestation, suggest that blowdowns may become more common in future in the Southern Rockies, but the consequences for carbon dynamics depend on site‐specific interactions between blowdowns and other processes such as floodplain storage of organic matter.
Inferring fault rheology from low‐frequency earthquakes on the San Andreas
Authors: Beeler N. M. , Thomas Amanda , Bürgmann Roland , Shelly David 
Published: November 2013

AbstractFamilies of recurring low‐frequency earthquakes (LFEs) within nonvolcanic tremor (NVT) on the San Andreas fault in central California show strong sensitivity to shear stress induced by the daily tidal cycle. LFEs occur at all levels of the tidal shear stress and are in phase with the very small, ~400 Pa, stress amplitude. To quantitatively explain the correlation, we use a model from the existing literature that assumes the LFE sources are small, persistent regions that repeatedly fail during shear of a much larger scale, otherwise aseismically creeping fault zone. The LFE source patches see tectonic loading, creep of the surrounding fault which may be modulated by the tidal stress, and direct tidal loading. If the patches are small relative to the surrounding creeping fault then the stressing is dominated by fault creep, and if patch failure occurs at a threshold stress, then the resulting seismicity rate is proportional to the fault creep rate or fault zone strain rate. Using the seismicity rate as a proxy for strain rate and the tidal shear stress, we fit the data with possible fault rheologies that produce creep in laboratory experiments at temperatures of 400 to 600°C appropriate for the LFE source depth. The rheological properties of rock‐forming minerals for dislocation creep and dislocation glide are not consistent with the observed fault creep because strong correlation between small stress perturbations and strain rate requires perturbation on the order of the ambient stress. The observed tidal modulation restricts ambient stress to be at most a few kilopascal, much lower than rock strength. A purely rate dependent friction is consistent with the observations only if the product of the friction rate dependence and effective normal stress is ~ 0.5 kPa. Extrapolating the friction rate strengthening dependence of phyllosilicates (talc) to depth would require the effective normal stress to be ~50 kPa, implying pore pressure is lithostatic. If the LFE source is on the order of tens of meters, as required by the model, rate‐weakening friction rate dependence (e.g., olivine) at 400 to 600°C requires that the minimum effective pressure at the LFE source is ~ 2.5 MPa.
Neutron background environment measured by the Mars Science Laboratory's Dynamic Albedo of Neutrons instrument during the first 100 sols
Authors: Jun I. , Mitrofanov I. , Litvak M. L. , Sanin A. B. , Kim W. , Behar A. , Boynton W. V. , DeFlores L. , Fedosov F. , Golovin D. , Hardgrove C. , Harshman K. , Kozyrev A. S. , Kuzmin R. O. , Malakhov A. , Mischna M. , Moersch J. , Mokrousov M. , Nikiforov S. , Shvetsov V. N. , Tate C. , Tret'yakov V. I. , Vostrukhin A. 
Published: November 2013

AbstractThe Dynamic Albedo of Neutrons (DAN) instrument on board Mars Science Laboratory has been operating successfully since the landing and has been making measurements regularly along Curiosity's traverse at the surface. DAN measures thermal (E < 0.4 eV) and epithermal neutrons (0.4 eV < E < ~1 keV) while operating in two different modes: active and passive. The active mode uses a pulsed neutron generator (PNG) to study the geological characteristics of the subsurface. In the passive mode, DAN measures the background neutron environment. This paper presents results of measurements in the passive mode from landing through to sol 100 and provides an interpretation of the data based on extensive Monte Carlo simulations. The main observations are summarized as follows: (1) the thermal neutron counts vary strongly along the rover traverse while the epithermal counts do not show much variation; (2) the neutrons from the Multi‐Mission Radioisotope Thermoelectric Generator (MMRTG) are a larger contributor to the DAN passive data than the Galactic Cosmic Ray (GCR)‐induced neutrons; (3) for the MMRTG neutrons, both the thermal and the epithermal counts increase as a function of the subsurface water content; (4) on the other hand, for the GCR‐induced neutrons, the thermal counts increase but the epithermal counts decrease as a function of the subsurface water content; and (5) relative contributions by the MMRTG and GCR to the DAN thermal neutron counts at the Rocknest site, where the rover was stationed from sol 59 to sol 100, are estimated to be ~60% and ~40%, respectively.
Regulation of bacterial metabolic activity by dissolved organic carbon and viruses
Authors: Xu Jie , Jing Hongmei , Sun Mingming , Harrison Paul J. , Liu Hongbin 
Published: November 2013

AbstractThe regulation of bacterial metabolic activity by viruses and dissolved organic carbon (DOC) was examined using natural microbial communities in three treatments (active viruses, inactive viruses, and virus free) at two contrasting coastal sites (pristine vs. eutrophic) with substantial differences in environmental conditions during the wet and dry seasons. Our results showed that net growth rates and production of bacterioplankton were reduced primarily by viruses via repressing metabolically active bacteria with high nucleic acid (HNA) content which had a high capacity for incorporating carbon, while bacterial respiration was primarily regulated by DOC lability. The quality of organic matter played a more important role in regulating bacterial growth efficiency (BGE) than the supply of organic matter in eutrophic coastal waters. The lack of HMW‐DOC and high carbon demand in the virus‐free treatment resulted in a significant increase in cell‐specific bacterial respiration, which was responsible for the lowest bacterial growth efficiency among the three treatments. The presence of viruses did not necessarily lower bacterial growth efficiency since virus‐induced mortality alleviated bacterial carbon demand and enhanced carbon cycling. Virus‐induced mortality was greater in relatively pristine waters than eutrophic waters, likely since the high supply of substrates alleviated the pressure of viral infection, through extracellular proteases produced by bacteria, which might result in the hydrolytic destruction or modification of viral capsids. An important implication of our results was that the input of riverine DOC and nutrients improved bacterial metabolic activity by alleviating virus‐induced mortality of bacteria in estuarine and coastal waters.
Nitrogen Dioxide‐Catalyzed Electrophilic Iodination of Arenes
Authors: Ren Yun‐Lai , Shang Huantao , Wang Jianji , Tian Xinzhe , Zhao Shuang , Wang Qian , Li Fuwei 
Published: November 2013

AbstractNitrogen dioxide is demonstrated to be an effective catalyst precursor for the iodination of alkoxy‐substituted benzenes and naphthalenes. Different from the transition metal catalysts, nitrogen dioxide can be easily separated from the final products, and is free of heavy metal waste. Although the present catalyst precursor is toxic, it does not stain the final products due to its low‐boiling character. No other reagents apart from 0.5 equiv. of iodine (I2), 6.5 mol% nitrogen dioxide and acetonitrile solvent were used in the iodination, and basically all the iodine atoms in the iodine source were transferred to the iodination products, showing that the presented protocol is highly atom‐economic and practical.magnified image
Family history and clefting as major criteria for CHARGE syndrome
Authors: Hughes Susan Starling , Welsh Holly I. , Safina Nicole P. , Bejaoui Khemissa , Ardinger Holly H. 
Published: November 2013

ABSTRACTCHARGE syndrome is an autosomal dominant malformation syndrome associated with mutations in CHD7. The condition is typically sporadic with few familial cases reported. The diagnosis of CHARGE syndrome is based on a combination of major and minor criteria comprised of structural and functional abnormalities, most of which are part of the original CHARGE acronym, although additional anomalies have been added. To date, family history has not been considered in the diagnostic criteria. Here we report a family with a previously unreported missense mutation in exon 31 of CHD7, in which family history played a role in the diagnosis of CHARGE syndrome. Given the tremendous phenotypic variability and the dominant nature of CHARGE syndrome, we propose that family history be included as a major diagnostic criterion. A positive family history would include any individual with an apparently isolated unilateral major CHARGE anomaly or someone with a few of the minor features. Our cases support this proposal; had family history not been considered in this case, CHD7 testing might not have been pursued, leading to incomplete medical follow‐up and erroneous genetic counseling. Additionally, with the increased incidence of orofacial clefting in this family, as well as in the literature, we suggest that cleft lip and/or palate be added to the major diagnostic criteria for CHARGE syndrome. © 2013 Wiley Periodicals, Inc.
Komplexe mit Stickstoffradikalliganden: Einteilung, spektroskopische Eigenschaften, Reaktivität und katalytische Anwendungen
Authors: Olivos Suarez Alma I. , Lyaskovskyy Volodymyr , Reek Joost N. H. , van der Vlugt Jarl Ivar , de Bruin Bas 
Published: November 2013

AbstractDer vorliegende Aufsatz gibt einen Überblick über die elektronische Struktur, die spektroskopischen Eigenschaften und die (katalytische) Reaktivität von Komplexen mit Stickstoffradikalliganden. Komplexe mit Aminyl‐ ([M(.NR2)]), Nitren/Imidyl‐ ([M(.NR)]) oder Nitridylradikalliganden ([M(.N)]) sind nachweisbare und manchmal auch isolierbare Spezies, die trotz ihres Radikalcharakters oft selektive Reaktionsmuster gegenüber einer Vielzahl organischer Substrate zeigen. Für Komplexe mit Stickstoffradikalliganden wird ein Klassifizierungssystem vorgestellt, das auf ihrer Elektronenstruktur basiert und sie als Einelektronen‐reduzierte Fischer‐Systeme, Einelektronen‐oxidierte Schrock‐Systeme oder Systeme mit (fast) kovalenter M‐N‐π‐Bindung beschreibt. Experimentelle, für die Bestimmung des Aufenthaltsortes des Radikals (d. h. Metall oder Ligand) relevante Ergebnisse werden diskutiert, und aktuelle Beispiele aus der Literatur belegen die Verwendung von Komplexen mit Stickstoffradikalliganden in den (katalytischen) Synthesen verschiedener organischer Stickstoffverbindungen wie Aziridine und Amine. Dieser Aufsatz soll dazu beitragen, die (katalytische) Reaktivität von Stickstoffradikalliganden und ihre Rolle bei der Feinabstimmung der Reaktivität von Koordinationsverbindungen besser zu verstehen.
Clamshell Opening in the Mixed‐Metal Supramolecular Aggregates Formed by Fourfold Reduced Corannulene for Maximizing Intercalated Metal Content
Authors: Filatov Alexander S. , Zabula Alexander V. , Spisak Sarah N. , Rogachev Andrey Yu. , Petrukhina Marina A. 
Published: November 2013

AbstractThe first members of a new class of supramolecular organometallic compounds with mixed‐alkali‐metal cluster cores, LiK5 and Li3K3, sandwiched between two four‐fold reduced corannulene decks are prepared and fully characterized. The triple‐decker supramolecular anions, [(C20H104−)(LiK5)6+(C20H104−)]2− and [(C20H104−)(Li3K3)6+(C20H104−)]2−, illustrate a record ability of bowl‐shaped and highly charged corannulene to provide all its sites, five benzene rings fused to a central five‐membered ring, for binding of six alkali‐metal ions. The previously unseen engagement of the hub‐site of C20H104− in lithium binding is accompanied by unprecedented shifts up to −24 ppm in 7Li NMR spectra. The discussion of product formation mechanism, augmented by calculations, is provided.
Complexes with Nitrogen‐Centered Radical Ligands: Classification, Spectroscopic Features, Reactivity, and Catalytic Applications
Authors: Suarez Alma I. Olivos , Lyaskovskyy Volodymyr , Reek Joost N. H. , van der Vlugt Jarl Ivar , de Bruin Bas 
Published: November 2013

AbstractThe electronic structure, spectroscopic features, and (catalytic) reactivity of complexes with nitrogen‐centered radical ligands are described. Complexes with aminyl ([M(.NR2)]), nitrene/imidyl ([M(.NR)]), and nitridyl radical ligands ([M(.N)]) are detectable and sometimes even isolable species, and despite their radical nature frequently reveal selective reactivity patterns towards a variety of organic substrates. A classification system for complexes with nitrogen‐centered radical ligands based on their electronic structure leads to their description as one‐electron‐reduced Fischer‐type systems, one‐electron‐oxidized Schrock‐type systems, or systems with a (nearly) covalent MN π bond. Experimental data relevant for the assignment of the radical locus (i.e. metal or ligand) are discussed, and the application of complexes with nitrogen‐centered radical ligands in the (catalytic) syntheses of nitrogen‐containing organic molecules such as aziridines and amines is demonstrated with recent examples. This Review should contribute to a better understanding of the (catalytic) reactivity of nitrogen‐centered radical ligands and the role they play in tuning the reactivity of coordination compounds.
Nanopore‐Based Sequencing and Detection of Nucleic Acids
Authors: Ying Yi‐Lun , Zhang Junji , Gao Rui , Long Yi‐Tao 
Published: November 2013

AbstractNanopore‐based techniques, which mimic the functions of natural ion channels, have attracted increasing attention as unique methods for single‐molecule detection. The technology allows the real‐time, selective, high‐throughput analysis of nucleic acids through both biological and solid‐state nanopores. In this Minireview, the background and latest progress in nanopore‐based sequencing and detection of nucleic acids are summarized, and light is shed on a novel platform for nanopore‐based detection.
The Cross‐Dehydrogenative Coupling of CH Bonds: A Versatile Strategy for CC Bond Formations
Authors: Girard Simon A. , Knauber Thomas , Li Chao‐Jun 
Published: November 2013

AbstractOver the last decade, substantial research has led to the introduction of an impressive number of efficient procedures which allow the selective construction of CC bonds by directly connecting two different CH bonds under oxidative conditions. Common to these methodologies is the generation of the reactive intermediates in situ by activation of both CH bonds. This strategy was introduced by the group of Li as cross‐dehydrogenative coupling (CDC) and discloses waste‐minimized synthetic alternatives to classic coupling procedures which rely on the use of prefunctionalized starting materials. This Review highlights the recent progress in the field of cross‐dehydrogenative CC formations and provides a comprehensive overview on existing procedures and employed methodologies.
Polypropylene fibers fabricated via a needleless melt‐electrospinning device for marine oil‐spill cleanup
Authors: Li Haoyi , Wu Weifeng , Bubakir Mahmoud M. , Chen Hongbo , Zhong Xiangfeng , Liu Zhaoxiang , Ding Yumei , Yang Weimin 
Published: November 2013

ABSTRACTUltrafine polypropylene (PP) fibers as oil sorbents were fabricated via a needleless melt‐electrospinning device and were characterized by scanning electron microscopy and contact‐angle analysis. PP fibers of various diameters and porosities were obtained by the manipulation of the applied electrical field. The effects of the fiber diameter and porosity on the oil‐sorption capacity and oil‐retention behavior were investigated. The experimental results demonstrate that for fiber diameter on the microscale, the porosity played a paramount role in determining the oil‐sorption capacities. The maximum oil‐sorption capacity of the resulting PP fibers with regard to motor oil and peanut oil were 129 and 80 g/g, respectively; these values were approximately six to seven times that of commercial PP nonwoven fabricated through the melt‐blown method. In addition, even after seven sorption/desorption cycles, the oil‐sorption capacity of the chosen sample was still maintained around 80 g/g, and above 97%, oil could be recovered. This indicated excellent reusability and recoverability. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40080.
Theoretical and practical considerations in electrostatic depositioning of charged polymers
Authors: Zeeb Benjamin , Thongkaew Chutima , Weiss Jochen 
Published: November 2013

ABSTRACTAn interfacial engineering technology, based on the electrostatic deposition of charged polyelectrolytes onto surfaces of oppositely charged templates is reviewed with an emphasis on practical applications in the food, pharmaceutical and personal care industries. On interfaces of disperse systems consecutively deposited polymers provide major advantages in terms of physical and chemical stability of dispersions against superimposed stresses (pH, temperature, ionic strength, freezing, chilling, dehydration, lipid oxidation). The controlled deposition of multiple layers allows for a controlled and triggered release of incorporated functional components. This review highlights the basic principles of the layer‐by‐layer (LbL) electrostatic deposition method as well as some major advantages and drawbacks of this approach. An overview of several systems that can be used as templates for the deposition including emulsion droplets, liposomal vehicles, colloidal aggregates, and planar surfaces is given. Suitable substrates for the deposition are presented with a focus on charged biopolymers such as proteins or polysaccharides since they play an essential role in the formulation and stabilization of food, pharmaceutical and personal care applications. Issues and difficulties associated with implementing the technology on a larger, industrial scale are discussed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40099.