bluuebunny/crossref_metadata_2025 huggingface dataset:
Site conditions determine a key native plant's contribution to invasion resistance in grasslands
Authors: Hulvey Kristin B. , Teller Brittany J.
Published: March 2018

Many plant invasion studies in grasslands suggest that resident plants that share functional traits with invaders can reduce invasion by competing for limiting resources. However, since invasion studies often occur in highly controlled plots or microcosms, it is unclear how heterogeneous site conditions alter competitive interactions under realistic scenarios. To explore how landscape heterogeneity affects biotic resistance provided by competitive resident plants, we conducted a field‐based experiment across four sites in California grasslands. Plots contained naturally occurring populations of nativeHemizonia congesta,but differed in other characteristics, including litter cover, annual grass cover, soil moisture, and species richness. We invaded plots with the functionally similar nonnativeCentaurea solstitalis(yellow starthistle) and, at one site, supplemented one‐half of the established plots with water to test the effects of increasing a limiting resource. As in simplified plots and microcosms, increasingH. congestaabundance reduced starthistle biomass by competing for limited soil moisture, but only in plots with high starthistle germination. We conclude that higher abundances of nativeH. congestacan reduce starthistle invasion in heterogeneous grasslands, but competition is also affected by both abiotic (soil moisture) and biotic (starthistle germination number) conditions that vary across sites.
River food webs: an integrative approach to bottom‐up flow webs, top‐down impact webs, and trophic position
Authors: Benke Arthur C.
Published: March 2018

The majority of food web studies are based on connectivity, top‐down impacts, bottom‐up flows, or trophic position (TP), and ecologists have argued for decades which is best. Rarely have any two been considered simultaneously. The present study uses a procedure that integrates the last three approaches based on taxon‐specific secondary production and gut analyses. Ingestion flows are quantified to create a flow web and the same data are used to quantify TP for all taxa. An individual predator's impacts also are estimated using the ratio of its ingestion (I) of each prey to prey production (P) to create an I/P web. This procedure was applied to 41 invertebrate taxa inhabiting submerged woody habitat in a southeastern U.S. river. A complex flow web starting with five basal food resources had 462 flows >1 mg·m−2·yr−1, providing far more information than a connectivity web. Total flows from basal resources to primary consumers/omnivores were dominated by allochthonous amorphous detritus and ranged from 1 to >50,000 mg·m−2·yr−1. Most predator–prey flows were much lower (<50 mg·m−2·yr−1), but some were >1,000  mg·m−2·yr−1. The I/P web showed that 83% of individual predator impacts were weak (<10%), whereas total predator impacts were often strong (e.g., 35% of prey sustained an impact >90%). Quantitative estimates of TP ranged from 2 to 3.7, contrasting sharply with seven integer‐based trophic levels based on longest feeding chain. Traditional omnivores (TP = 2.4–2.9) played an important role by consuming more prey and exerting higher impacts on primary consumers than strict predators (TP ≥ 3). This study illustrates how simultaneous quantification of flow pathways, predator impacts, and TP together provide an integrated characterization of natural food webs.
ForC: a global database of forest carbon stocks and fluxes
Authors: Anderson‐Teixeira Kristina J. , Wang Maria M. H. , McGarvey Jennifer C. , Herrmann Valentine , Tepley Alan J. , Bond‐Lamberty Ben , LeBauer David S.
Published: March 2018

Forests play an influential role in the global carbon (C) cycle, storing roughly half of terrestrial C and annually exchanging with the atmosphere more than five times the carbon dioxide (CO2) emitted by anthropogenic activities. Yet, scaling up from field‐based measurements of forest C stocks and fluxes to understand global scale C cycling and its climate sensitivity remains an important challenge. Tens of thousands of forest C measurements have been made, but these data have yet to be integrated into a single database that makes them accessible for integrated analyses. Here we present an open‐access global Forest Carbon database (ForC) containing previously published records of field‐based measurements of ecosystem‐level C stocks and annual fluxes, along with disturbance history and methodological information. ForC expands upon the previously published tropical portion of this database, TropForC (https://doi.org/10.5061/dryad.t516f), now including 17,367 records (previously 3,568) representing 2,731 plots (previously 845) in 826 geographically distinct areas. The database covers all forested biogeographic and climate zones, represents forest stands of all ages, and currently includes data collected between 1934 and 2015. We expect that ForC will prove useful for macroecological analyses of forest C cycling, for evaluation of model predictions or remote sensing products, for quantifying the contribution of forests to the global C cycle, and for supporting international efforts to inventory forest carbon and greenhouse gas exchange. A dynamic version of ForC is maintained at on GitHub (https://GitHub.com/forc-db), and we encourage the research community to collaborate in updating, correcting, expanding, and utilizing this database. ForC is an open access database, and we encourage use of the data for scientific research and education purposes. Data may not be used for commercial purposes without written permission of the database PI. Any publications using ForC data should cite this publication and Anderson‐Teixeira et al. (2016a) (see Metadata S1). No other copyright or cost restrictions are associated with the use of this data set.
Prevalence, clinical correlates, and outcomes of anaemia in multi‐ethnic Asian patients with heart failure with reduced ejection fraction
Authors: Goh Vera J. , Tromp Jasper , Teng Tiew‐Hwa K. , Tay Wan Ting , Van Der Meer Peter , Ling Lieng Hsi , Siswanto Bambang B. , Hung Chung‐Lieh , Shimizu Wataru , Zhang Shu , Narasimhan Calambur , Yu Cheuk Man , Park Sang Weon , Ngarmukos Tachapong , Liew Houng Bang , Reyes Eugenio , Yap Jonathan , MacDonald Michael , Richards Mark A. , Anand Inder , Lam Carolyn S.P. ,   on behalf of the ASIAN‐HF investigators
Published: March 2018

Aims

Recent international heart failure (HF) guidelines recognize anaemia as an important comorbidity contributing to poor outcomes in HF, based on data mainly from Western populations. We sought to determine the prevalence, clinical correlates, and prognostic impact of anaemia in patients with HF with reduced ejection fraction across Asia.

Methods and results

We prospectively studied 3886 Asian patients (60 ± 13 years, 21% women) with HF (ejection fraction ≤40%) from 11 regions in the Asian Sudden Cardiac Death in Heart Failure study. Anaemia was defined as haemoglobin <13 g/dL (men) and <12 g/dL (women). Ethnic groups included Chinese (33.0%), Indian (26.2%), Malay (15.1%), Japanese/Korean (20.2%), and others (5.6%). Overall, anaemia was present in 41%, with a wide range across ethnicities (33–54%). Indian ethnicity, older age, diabetes, and chronic kidney disease were independently associated with higher odds of anaemia (all P < 0.001). Ethnicity modified the association of chronic kidney disease with anaemia (Pinteraction = 0.045), with the highest adjusted odds among Japanese/Koreans [2.86; 95% confidence interval (CI) 1.96–4.20]. Anaemic patients had lower Kansas City Cardiomyopathy Questionnaire scores (P < 0.001) and higher risk of all‐cause mortality and HF hospitalization at 1 year (hazard ratio = 1.28, 95% CI 1.08–1.50) compared with non‐anaemic patients. The prognostic impact of anaemia was modified by ethnicity (Pinteraction = 0.02), with the greatest hazard ratio in Japanese/Koreans (1.82; 95% CI 1.14–2.91).

Conclusions

Anaemia is present in a third to more than half of Asian patients with HF and adversely impacts quality of life and survival. Ethnic differences exist wherein prevalence is highest among Indians, and survival is most severely impacted by anaemia in Japanese/Koreans.
Augmentation of glucagon‐like peptide‐1 receptor signalling by neprilysin inhibition: potential implications for patients with heart failure
Authors: Packer Milton
Published: March 2018

Augmentation of glucagon‐like peptide‐1 (GLP‐1) receptor signalling is an established approach to the treatment of type 2 diabetes. However, endogenous GLP‐1 and long‐acting GLP‐1 receptor analogues are degraded not only by dipeptidyl peptidase‐4, but also by neprilysin. This observation raises the possibilities that endogenous GLP‐1 contributes to the clinical effects of neprilysin inhibition and that patients concurrently treated with sacubitril/valsartan and incretin‐based drugs may experience important drug–drug interactions. Specifically, potentiation of GLP‐1 receptor signalling may underlie the antihyperglycaemic actions of sacubitril/valsartan. Neprilysin inhibitors may also be able to augment the effects of long‐acting GLP‐1 analogues to increase heart rate and myocardial cyclic AMP, and thus, potentiate these deleterious actions; if so, concomitant treatment with GLP‐1 receptor agonists may limit the efficacy of neprilysin inhibitors in patients with both heart failure and diabetes. For patients not concurrently treated with GLP‐1 analogues, the action of neprilysin to enhance the effects of GLP‐1 may be particularly relevant in the brain, where augmentation of GLP‐1 and other endogenous peptides may act to inhibit amyloid‐induced neuroinflammation and cytotoxicity and improve memory formation and executive functioning. Experimentally, neprilysin inhibitors may also potentiate the effects of endogenous GLP‐1 and GLP‐1 receptor agonists on blood vessels and the kidney. The role of neprilysin in the metabolism of endogenous GLP‐1 and long‐acting GLP‐1 analogues points to a range of potential pathophysiological effects that may be clinically relevant to patients with heart failure, with or without diabetes.
Aberrant cell signalling in PBMCs upon IFN‐α stimulation in primary Sjögren's syndrome patients associates with type I interferon signature
Authors: Davies Richard , Hammenfors Daniel , Bergum Brith , Vogelsang Petra , Gavasso Sonia , Brun Johan G. , Jonsson Roland , Appel Silke
Published: March 2018

Primary Sjögren's syndrome (pSS) is a complex systemic autoimmune disease with heterogeneous disease manifestations. Genetic predisposition, hormonal and environmental factors are all thought to contribute to disease etiology and pathogenesis. A better understanding of the disease pathogenesis is required in order to establish new targeted therapies. We analysed MAPK/ERK and JAK/STAT signalling networks in peripheral blood mononuclear cells (PBMCs) upon stimulation with interferon alpha 2b (IFN‐α2b) by flow cytometry to define potentially dysfunctional intracellular signalling pathways involved in disease pathogenesis. Cells derived from pSS patients displayed small but significant increases in basal phosphorylation levels of numerous signalling proteins compared to cells from healthy donors. The phosphorylation profiles following stimulation with IFNα2b differed significantly between pSS patients and healthy donors, especially regarding STAT1 Y701. PCA further grouped patients according to clinical characteristics. Type I IFN induced gene expression was found to negatively correlate with the IFN‐α2b induced phosphorylation of STAT3 S727 in T cells and positively with pSTAT1 Y701 in B cells. Increases in pSTAT1 Y701 were associated with the presence of autoantibodies. Our results indicate involvement of both STAT3 S727 and STAT1 Y701 pathways in pSS patients. Therapies targeting these pathways might therefore be beneficial for certain subgroups of patients.
Hypersensitive Self‐Referencing Detection Traces of Water in Ethyl Alcohol by Dual‐Emission Lanthanide Metal–Organic Frameworks
Authors: Ji Guanfeng , Wang Jinzeng , Gao Xuechuan , Liu Jingjuan , Guan Weihua , Liu Houting , Liu Zhiliang
Published: March 2018

A sequence of isostructural lanthanide metal–organic frameworks (MOFs) [TbxEu1–xNa(HL2)2(H3L2)0.5]·EtOH [H3L2 = 5‐hydroxy‐isophthalic acid] (x = 0.1–0.9) are successfully obtained by doping TbIII and EuIII into the same framework. A fluent change in their photoluminescence is achieved by varying the ratio of TbIII/EuIII from 1:9 to 9:1. Among the obtained lanthanide MOFs, [Tb0.5Eu0.5Na(HL2)2(H3L2)0.5]·EtOH displays remarkable dual emission, with macroscopic bright red–orange luminescence in ethyl alcohol that is easily quenched, even with a low water content, thus presenting an innovative approach for an ideal chemical sensor for the detection of trace amounts of water in ethyl alcohol. As the water content increases, the probe exhibits a distinguishable change in its luminescence. To the best of our knowledge, it is quite rare for a self‐referencing luminescent sensor to be able to quantify the amount of water in ethyl alcohol over a wide range (0.01–3.2 %). The detection limit of the codoped Ln MOFs is 0.01 %, which is ahead of other reported MOF‐based sensors.
Cyclic RGD‐Coated Ultrasmall Gd2O3 Nanoparticles as Tumor‐Targeting Positive Magnetic Resonance Imaging Contrast Agents
Authors: Ahmad Mohammad Yaseen , Ahmad Mohammad Wasi , Cha Hyunsil , Oh In‐Taek , Tegafaw Tirusew , Miao Xu , Ho Son Long , Marasini Shanti , Ghazanfari Adibehalsadat , Yue Huan , Ryeom Hun‐Kyu , Lee Jongmin , Chae Kwon Seok , Chang Yongmin , Lee Gang Ho
Published: March 2018

The excellent theranostic properties of gadolinium oxide (Gd2O3) nanoparticles (GNPs) make them very useful as high‐performance positive magnetic resonance imaging (T1 MRI) contrast agents, X‐ray computed tomography (CT) contrast agents, and gadolinium neutron capture therapy (GdNCT) agents in tumor targeting. Among these applications, tumor‐targeting T1 MRI is investigated in this study. To this end, we employ cyclic RGDs (cRGDs; cyclic Arg–Gly–Asp peptides) as tumor‐targeting ligands to coat ultrasmall GNPs (particle diameter = 1.0–2.5 nm). Five types of commercial cRGDs are used in the coating. The cRGD‐coated GNPs (cRGD‐GNPs) are prepared through one‐pot syntheses. They exhibit longitudinal water‐proton relaxivity (r1) values of 10.0–18.7 s–1 mm–1, with r2/r1 ratios of 1.4–1.7 (r2 = transverse water‐proton relaxivity), which are 3–5 times higher than those of commercial Gd chelates. The in vivo tumor targeting of the cRGD‐GNPs is demonstrated by taking T1 MR images in a model mouse with a liver tumor using one of the five cRGD‐GNP sample solutions prepared. Approximately threefold contrast enhancements are observed in the T1 MR images in the tumor region of the liver than in the normal part of the liver, following intravenous administration of the solution. These results demonstrate that cRGD‐GNPs are potential tumor‐targeting T1 MRI contrast agents.
Light‐Induced Spin‐State Switching of the MoIV Centre in Trinuclear [CuII(diamine)2]2[MoIV(CN)8] Molecules
Authors: Korzeniak Tomasz , Sasmal Sujit , Pinkowicz Dawid , Stefańczyk Olaf , Sieklucka Barbara
Published: March 2018

New trinuclear molecules [Cu(meen)2]2[MoIV(CN)8]·5H2O (1) and [Cu(eten)2]2[Mo(CN)8]·7H2O (2) (meen = N‐methyl‐ethylenediamine; eten = N‐ethyl‐ethylenediamine) have been prepared and characterised by X‐ray diffraction and dc magnetometry. The crystal structure of 1 and 2 consists of trinuclear Cu2Mo molecules interacting through weak semicoordination bonds and resulting in the formation of 2D and 3D supramolecular networks, respectively. In the ground state, both molecules exhibit simple paramagnetic behaviour, with very weak antiferromagnetic interaction present at low temperatures. The photomagnetic studies of 1 and 2, performed using 436 nm light, have shown a significant increase in the magnetisation upon irradiation that might be explained in terms of a singlet–triplet transition at MoIV.
NaCl Replacement with KCl Affects Lipolysis, Microbiological and Sensorial Features of Soppressata Molisana
Authors: Tremonte Patrizio , Gambacorta Giuseppe , Pannella Gianfranco , Trani Antonio , Succi Mariantonietta , La Gatta Barbara , Tipaldi Luca , Grazia Luigi , Sorrentino Elena , Coppola Raffaele , Di Luccia Aldo
Published: March 2018

The influence of partial replacement of NaCl with KCl on the lipolysis and on the microbial and sensory features of Soppressata molisana is investigated during 50 days of ripening. In addition, the relation between KCl and a multiple strain starter culture is also considered and the effects of their combination on some quality features are examined. The lipolysis, the microbiological and sensorial features and the lipid oxidation of experimental batches, are compared with those exhibited by control batches. The results highlight that the KCl, used as an alternative salt, is able to inhibit undesirable microorganisms equally to NaCl, ensuring the safety of the final products. In addition, a stimulating effect on the growth of added bacteria is detected in presence of KCl, with a resulting better fermentative process. In fact, the addition of KCl, even if produces a decrease in lipolytic activities, improves the nutritional value of soppressata molisana, in terms of higher PUFA/SFA ratio. These advantages are further amplified when the alternative salt is used in combination with the starter culture. Finally, the combined use of KCl and starter culture reduces the lipid oxidation and seems crucial for maintaining the sensorial features.

Pratical Applications: The main findings of the present research highlight that the use of KCl in combination with an appropriately selected starter culture allows the production of healthier and safety dry‐fermented sausage (soppressata molisana) and consistent with WHO guidelines and modern consumers demand.

Partial replacement of NaCl with KCl affects the behaviour of fermentative and lipolytic process in Soppressata molisana. KCl, in combination with a multiple strain starter culture, improves the nutritional features of dry‐fermented sausage by promoting lower SFA and higher MUFA and PUFA levels. Moreover, the innovative approach preserves sensorial features of traditional‐fermented sausages limiting lipid oxidation.
Chemical Glucosylation of Labile Natural Products Using a (2‐Nitrophenyl)acetyl‐Protected Glucosyl Acetimidate Donor
Authors: Weber Julia , Schwarz Markus , Schiefer Andrea , Hametner Christian , Häubl Georg , Fröhlich Johannes , Mikula Hannes
Published: March 2018

The synthesis of (2‐nitrophenyl)acetyl (NPAc)‐protected glucosyl donors is described that were designed for the neighboring‐group assisted glucosylation of base‐labile natural products also being sensitive to hydrogenolysis. Glycosylation conditions were optimized using a trichloroacetimidate glucosyl donor, and cyclohexylmethanol and (+)‐menthol as model acceptors. The approach was then extended to a one‐pot procedure for the synthesis of 1,2‐trans‐glycosides. This method was finally applied for improved synthesis of the masked mycotoxin T2‐O‐β,d‐glucoside.
Highly Regioselective Isoquinoline Synthesis via Nickel‐Catalyzed Iminoannulation of Alkynes at Room Temperature
Authors: Sun Jian‐Guo , Zhang Xiao‐Yu , Yang Hua , Li Ping , Zhang Bo
Published: March 2018

A simple and cost‐efficient nickel catalytic system for the annulation of 2‐haloaldimines with alkynes to synthesize 3,4‐disubstituted and 3‐substituted isoquinolines at room temperature has been developed. The air‐stable and inexpensive Ni(dppe)Cl2 was employed as a precatalyst, and Et3N was found to be an essential additive for obtaining high yields. By using this nickel catalytic system one‐pot three‐component direct synthesis of isoquinolines starting with simple 2‐halobenzaldehydes, tert‐butylamine, and alkynes were also achieved. These reactions occur in moderate to excellent yields with complete regioselectivity. Moreover, these reactions feature a broad substrate scope, easy scalability, operational simplicity, and excellent practicality.
Conformationally Constrained Mono‐Fluorinated Arginine as a Cationic Label for Solid‐State 19F NMR Analysis of Membrane‐Bound Peptides
Authors: Michurin Oleg M. , Tolmachova Kateryna , Afonin Sergii , Babii Oleg , Grage Stephan L. , Ulrich Anne S. , Komarov Igor V. , Radchenko Dmytro S.
Published: March 2018

A conformationally constrained mono‐fluorinated analogue of arginine, (1S,3S)‐1‐amino‐3‐fluoro‐3‐(guanidinomethyl)cyclobutane‐1‐carboxylic acid (F‐CbArg), has been designed as a label for solid‐state 19F NMR spectroscopy. The compound was synthesized and its structural and functional similarity to arginine demonstrated in the context of a representative antimicrobial peptide. The cationic 19F NMR label was incorporated into the amphiphilic helix of temporin A and provided information on water and phosphate contacts within the lipid environment, thereby demonstrating the utility of F‐CbArg in structural studies of membrane‐bound peptides.
λ3‐Pyrroloazaphosphinines with Relatively Stable P=C Double Bonds
Authors: Huang Haiyang , Wei Zhibin , Hou Jingjing , Wang Ruoqing , Tao Guanyu , Wang Mincan , Duan Zheng , Mathey François
Published: March 2018

The first pyrroloazaphosphinines with nitrogen at the junction, 7a and 7b, have been prepared by a special route involving the collapse of the phosphorus bridges of appropriate 7‐phosphanorbornenes. The parent molecule 7a has a strictly planar azaphosphinine ring with some electronic delocalization according to DFT computations. Its P=C double bond does not react with 2,3‐dimethylbutadiene unless P is coordinated to Mo(CO)5. Compound 7a reacts with CuI to give a new type of polymeric complex [–Cu‐µ2‐7a–]n in which P acts as a bridging ligand and the ligand planes are antiparallel. The benzo‐annulated and bromo‐substituted 7b displays a skewed ring according to DFT computations and its P=C double bond is reactive toward 2,3‐dimethylbutadiene without complexation.
Carbon Nanohorn‐modified Carbon Fiber Microelectrodes for Dopamine Detection
Authors: Puthongkham Pumidech , Yang Cheng , Venton B. Jill
Published: March 2018

Carbon nanohorns (CNHs), closed cone‐shaped cages of sp2‐hybridized carbons, are a promising nanomaterial to improve carbon‐fiber microelectrode (CFME) dues to their high specific surface area and edge planes, but few studies have tested their electrochemical properties. Here, we tested dopamine detection at electrodeposited CNHs on CFME (CNH/CFME). The optimized concentration of CNHs in the deposition solution is 0.5 mg/mL, and the optimized electrodeposition waveform is 10 cycles of triangular waveform scanned from −1.0 V and +1.0 V at 50 mV/s. Using fast‐scan cyclic voltammetry, the optimized CNH/CFME enhances dopamine peak current to 2.3±0.2 times that of the CFME. To further increase the current, CNH/CFMEs were oxidized in NaOH (ox‐CNH/CFME), which creates more defects and surface oxide groups to adsorb dopamine. The oxidative etching further increases the peak current to 3.5±0.2 times of the CFME, and ox‐CNH/CFME had a limit of detection of 6±2 nM. The dopamine anodic current at ox‐CNH/CFME was stable for 8 h of continuous scanning. The ox‐CNH/CFME enhanced the anodic peak current for other cationic neurotransmitters including epinephrine, norepinephrine, and serotonin, but less enhancement was found for ascorbic acid, showing higher selectivity for cationic molecules. CNHs also decreased tissue biofouling at CFME. Thus, electrodeposited CNHs are a promising new method for increasing the surface area and current of CFMEs for dopamine detection.
Extraction approaches used for the determination of biologically active compounds (cyclitols, polyphenols and saponins) isolated from plant material
Authors: Ligor Magdalena , Ratiu Ileana‐Andreea , Kiełbasa Anna , Al‐Suod Hossam , Buszewski Bogusław
Published: March 2018

Based on the bioactive properties of certain compounds, such as antioxidant and anti‐inflammatory activities, an interesting subject of research are natural substances present in various parts of plants. The choice of the most appropriate method for separation and quantification of biologically active compounds from plants and natural products is a crucial step of any analytical procedure. The aim of this review article is to present an overview of a comprehensive literature study from the last 10 years (2007–2017), where relevant articles exposed the latest trends and the most appropriate methods applicable for separation and quantification of biologically active compounds from plant material and natural products. Consequently, various extraction methods have been discussed, together with the available procedures for purification and pre‐concentration and dedicated methods used for analysis.
On the electrophoretic mobilities of partially charged oligosaccharides as a function of charge patterning and degree of polymerization
Authors: Irani Amir H. , Mercadante Davide , Williams Martin A.K.
Published: March 2018

Fully or partially charged oligosaccharide molecules play a key role in many areas of biology, where their fine structures are crucial in determining their functionality. However, the separation of specific charged oligosaccharides from similar moieties that typically coexist in extracted samples, even for those that are unbranched, and in cases where each saccharide moiety can only carry a single charge or not, is far from trivial. Typically such molecules are characterized by a degree of polymerization n and a number m (and distribution) of charged residues, and must be separated from a plethora of similar species possessing different combinations of n and m. Furthermore, the separation of the possible isomers of each species of fixed n and m is a formidable challenge to analytical chemists. Herein, we report the results of molecular dynamics simulations that have been performed in order to calculate the free solution electrophoretic mobilities of galacturonides and charged oligosaccharides derived from digests of the important plant cell‐wall polysaccharide pectin. The simulations are compared with an experiment and are found to correctly predict the loss of resolution of fully charged species above a critical degree of polymerization n and the ionic strength dependence of the electrophoretic mobilities of different partially charged oligosaccharides. It is expected that having a predictive tool for the calculation of the electrophoretic mobilities of differently charged oligosaccharide species in hand will allow experimental conditions that optimize the resolution of particular species to be ascertained and understood.
Hydrothermal Decarboxylation of Corn Distillers Oil for Fuel‐Grade Hydrocarbons
Authors: Hossain Md. Zakir , Jhawar Anil Kumar , Chowdhury Muhammad B. I. , Xu William Z. , Charpentier Paul A.
Published: March 2018

Catalytic hydrothermal conversion of non‐edible corn distillers oil (CDO), a low‐value by‐product of the ethanol industries, into high value fuel‐grade hydrocarbons was investigated in near‐supercritical water. The decarboxylation experiments were conducted using activated carbon in a 300 mL batch stirred tank reactor at reaction temperatures of 300–400 °C with pressure ranges from 2200–2500 psi (≈15–17 MPa), water/CDO (v/v) ratios of 2:1 to 5:1, and reaction times of 0.5 to 4 h at constant stirring speed (800 rpm). For the first time, complete removal of the −COO− group from CDO was achieved at 400 °C with 4 h of reaction time and a water/CDO (v/v) ratio of 4:1. The liquid products obtained were a mixture of saturated hydrocarbons, mainly C8–C16 (selectivity 49.7 %) and heptadecane (48.9 %) which have similar specific gravity, higher heating value (HHV), cloud points, and pour points to those of commercial fuels. 65 % liquid yield was obtained under optimal reaction conditions. The reaction mechanism was found to follow pseudo‐first‐order kinetics with an activation energy 66.1±3 kJ mol−1, which is much lower than similar reported literature values for the decarboxylation process.
Assessment of a capacity spectrum seismic design approach against cyclic and seismic experiments on full‐scale precast RC structures
Authors: Dal Lago Bruno , Molina Francisco J.
Published: March 2018

Within the last decades, simplified methods alternative to dynamic nonlinear analysis have been developed to estimate the seismic performance of structures toward a performance‐oriented design. Considering drift as the main parameter correlated with structural damage, its estimation is of main importance to assess the structural performance. While traditional force‐based design deals with calibrated force reduction factors based on the expected structural ductility, other methods are based on the definition of a viscous damping factor defined as a function of the expected energy dissipated by the structure. An example is the capacity spectrum method. This method can be applied even without any a priori calibration or designer arbitrariness. This allows considering several peculiarities of the seismic behavior of precast structures, which may be influenced by nontraditional hysteresis of connections and members, interaction with the cladding panels,P‐δeffects, etc. The paper aims at verifying the soundness and accuracy of this method through the comparison of its predictions against the results of cyclic and pseudodynamic tests on precast structures, including single‐ and multistory buildings either stiff or flexible, obtained on full‐scale building prototypes tested within the framework of recent research projects (namely, “Precast Structures EC8,” “Safecast,” and “Safecladding”). Two simple methodologies of determination of the equivalent viscous damping from a force‐displacement cycle, based on the dissipated energy in relation to 2 different estimates of the elastic strain energy, are addressed and compared. Comments on the possible use of this procedure for the estimation of the seismic performance of precast structures are provided.
Displacement reduction effect and simplified evaluation method for SDOF systems using a clutching inerter damper
Authors: Wang Meng , Sun Feifei
Published: March 2018

This study evaluates the response reduction effect of linear single degree of freedom systems with a clutching inerter damper (CID) via parametric analysis under harmonic excitations and real earthquake records. The cause of the displacement reduction effect of a CID is inherited from the inertial mass damper (IMD)—reducing the nominal load intensity by increasing the mass by inertance. Additionally, the displacement reduction effect is further enhanced by the clutching effect, which speeds up the decreasing of the velocity response from an instantaneous extremum to 0. Thus, the CID is more effective than the IMD at reducing displacement responses. For example, the displacement response for a long‐period structure with a CID can be reduced by approximately 53%, while for an IMD, it can only be reduced by approximately 24%. Additionally, the linear single degree of freedom system with a CID is a weak nonlinear system reserving homogeneity, indicating that the response reduction factor will provide enough information to reveal the seismic reduction effect of the CID and that there is no need to consider the amplitude of the input excitations. To simplify the analysis of such nonlinear systems, an equivalent linearization method and a simplified formula of displacement reduction factors for code‐based designs are proposed and validated by another independent set of records from the European Strong‐motion Database.
Location and probability of shoal margin collapses in a sandy estuary
Authors: van Dijk Wout M. , Mastbergen Dick R. , van den Ham Geeralt A. , Leuven Jasper R. F. W. , Kleinhans Maarten G.
Published: March 2018

Channel bank failure, and collapses of shoal margins and beaches due to flow slides, have been recorded in Dutch estuaries for the past 200 years but have hardly been recognized elsewhere. Current predictions lack forecasting capabilities, because they were validated and calibrated for historic data of cross‐sections in specific systems, allowing local hindcast rather than location and probability forecasting. The objectives of this study were to investigate where on shoal margins collapses typically occur and what shoal margin collapse geometries and volumes are, such that we can predict their occurrence. We identified shoal margin collapses, generally completely submerged, from bathymetry data by analyzing digital elevation models of difference of the Western Scheldt for the period 1959–2015. We used the bathymetry data to determine the conditions for occurrence, specifically to obtain slope height and angle, and applied these variables in a shoal margin collapse predictor. We found 299 collapses along 300 km of shoal margin boundaries over 56 years, meaning that more than five collapses occur on average per year. The average shoal margin collapse body is well approximated by a 1/3 ellipsoid shape, covers on average an area of 34 000 m2 and has an average volume of 100 000 m3. Shoal margin collapses occur mainly at locations where shoals take up a proportionally larger area than average in the cross‐section of the entire estuary, and occur most frequently where lateral shoal margin displacement is low. A receiver operating characteristic curve shows that the forecasting method predicts the shoal margin collapse location well. We conclude that the locations of the shoal margin collapses are well predicted by the variation in conditions of the relative slope height and angle within the Western Scheldt, and likely locations are at laterally relatively stable shoal margins. This provides hypotheses aiding the recognition of these features in sandy estuaries worldwide. Copyright © 2018 John Wiley & Sons, Ltd.
Investigation of a new passive sampler for the detection of munitions compounds in marine and freshwater systems
Authors: Warren Joseph K. , Vlahos Penny , Smith Richard , Tobias Craig
Published: March 2018

Over the last century, unexploded ordnances have been disposed of in marine shelf systems because of a lack of cost-effective alternatives. Underwater unexploded ordnances have the potential to leak 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitro-1,3,5-triazine (RDX), commonly used chemical munitions, and contaminate local waters, biota, and sediments. The rate at which this contamination occurs in the environment is relatively unknown, and the cost- and time-prohibitive nature of sampling across sites makes mapping difficult. In the present study we assessed the efficacy of ethylene-vinyl acetate (EVA) for sampling relatively soluble munitions compounds over a range of environmental conditions (i.e., changes in temperature and salinity) and optimized the composition of the passive sampling polymer. The EVA sampler was able to successfully detect ambient concentrations of lingering munitions compounds from field sites containing unexploded ordnances. The sampler affinity for the munitions in terms of an EVA–water partition coefficient was greater than the standard octanol water values for each target compound. Partitioning of compounds onto EVA over the natural ranges of salinity did not change significantly, although uptake varied consistently and predictably with temperature. Increasing the vinyl acetate to ethylene ratio of the polymer corresponded to an increase in uptake capacity, consistent with enhanced dipole–dipole interactions between the munitions and the polymer. This sampler provides a cost-effective means to map and track leakage of unexploded ordnances both spatially and temporally. Environ Toxicol Chem 2018;37:1990–1997. © 2018 SETAC
Characterizing the behavior, uptake, and toxicity of NM300K silver nanoparticles in Caenorhabditis elegans
Authors: Kleiven Merethe , Rossbach Lisa M. , Gallego-Urrea Julian A. , Brede Dag A. , Oughton Deborah H. , Coutris Claire
Published: March 2018

Using Caenorhabditis elegans as a model organism, we addressed the potential linkage among toxicity of NM300K Ag nanoparticles (AgNPs), their particle size distribution, and the presence of dissolved Ag in the test media. Of the 3 endpoints assessed (growth, fertility, and reproduction), reproduction was the most sensitive, with the 50% effect concentration (EC50) ranging from 0.26 to 0.84 mg Ag L−1 and 0.08 to 0.11 mg Ag L−1 for NM300K and AgNO3, respectively. Silver uptake by C. elegans was similar for both forms of Ag, whereas bioaccumulation was higher in AgNO3 exposure. The observed differences in toxicity between NM300K and AgNO3 did not correlate with bioaccumulated Ag, which suggests that toxicity is a function of the type of exposing agent (AgNPs vs AgNO3) and its mode of action. Before addition of the food source (Escherichia coli), size fractionation revealed that dissolved Ag comprised 13 to 90% and 4 to 8% of total Ag in the AgNO3 and NM300K treatments, respectively. No dissolved Ag was detectable in the actual test media due to immediate Ag adsorption to bacteria. The results of the present study indicate that information on behavior and characterization of exposure conditions is essential for nanotoxicity studies. Environ Toxicol Chem 2018;37:1799–1810. © 2018 SETAC

Abstract

Exposure to AgNO3 induced higher toxicity to nematodes than NM300K silver nanoparticles. This could not be explained by differences in bioaccumulation, but by Ag speciation in the exposure media. EC50 = 50% effect concentration.
Deep learning–based network application classification for SDN
Authors: Zhang Chuangchuang , Wang Xingwei , Li Fuliang , He Qiang , Huang Min
Published: March 2018

Accurate application classification is important and useful to improve network performance. However, with the continuous expansion of network scale and the rapid increase of network users, it is very difficult for the existing application classification methods to accurately identify and classify network applications. Currently, most classification methods are suitable for small‐scale data sets and cannot achieve high classification accuracy because of the shallow learning structure and the limited learning ability. The emergence of deep learning technology and software‐defined networking (SDN) enables the application classification method to process large‐scale data. In this paper, by leveraging the SDN architecture, we present a novel hybrid deep neural network–based application classification method, which achieves high classification accuracy without the manual feature selection and extraction. In the proposed application classification framework, by taking the advantage of the logical centralized control and powerful computing capability, the massive network traffic is easily collected and processed by the SDN controller. The processed data is used to train the hybrid deep neural network, which is composed of the stacked autoencoder and softmax regression layer. The deep flow features can be obtained from the stacked autoencoder automatically instead of the manual feature selection and extraction. The softmax regression layer is used as the classifier to realize the application classification. Finally, simulation results demonstrate that our proposed classification method is effective and gets higher classification accuracy than the support vector machine–based classification method.
Analyzing selective relaying for multiple‐relay–based differential DF‐FSO network with pointing errors
Authors: Agarwal Deepti , Bansal Ankur , Kumar Ashwni
Published: March 2018

In this paper, we examine differential modulation for the decode‐and‐forward(DF) based cooperative free‐space optical (FSO) network. We consider multiple relays for transmitting differential binary phase‐shift keying (DBPSK) data from an optical source to destination along with a direct path between the two. The relays utilize the selective relaying protocol where the source data is forwarded to the destination only in the case of error‐free decoding by the relays. We derive the unified expression of probability density function (PDF) of the signal‐to‐noise ratio (SNR) for generalized‐
(
) distribution with pointing error (PE) considering both intensity modulation/direct detection (IM/DD) and heterodyne detection techniques. The derived unified PDF of SNR for
distribution is mathematically combined with the unified PDF of SNR for the Gamma‐Gamma (GG) distribution. This combining enables us to obtain a single closed‐form expression for a particular performance metric, which is applicable to both
and GG distributions with PE and both IM/DD and heterodyne detection techniques. More specifically, we derive the average bit error rate (ABER) and outage probability(OP) for the considered multiple‐relay–based DF‐FSO network. Furthermore, we analyze the asymptotic BER and asymptotic outage performances for the considered system at high SNR of source to relay links and obtain the diversity order, analytically. The impact of different power allocation schemes on ABER and OP is determined by utilizing the power allocation factor. The derived results clearly demonstrate the impact of severe atmospheric conditions, PE, the type of detection scheme, and the number of relays on the network performance. All the derived analytical results are verified through simulations.
Regularization modelling for large‐eddy simulation in wall‐bounded turbulence: An explicit filtering‐based approach
Authors: Chatterjee Tanmoy , Peet Yulia T.
Published: March 2018

A comprehensive analysis of a filtering‐based regularization model for large‐eddy simulation has been carried out for fully developed turbulent channel flow, and its potency as a large‐eddy simulation candidate has been tested by comparison with eddy‐viscosity subgrid‐scale models. The exponentially accurate spectral element method, particularly open‐source code Nek5000, has been used for such computations. The simulations in the channel flow have been performed at moderately high bulk Reynolds number on the basis of half channel width, 20 000, and compared against the direct numerical simulation database for the mean flow profile, second‐order statistics, and their streamwise energy spectra. The results show that the filtering‐based regularization model is in reasonably good agreement with the subgrid‐scale models, and they also elucidate valuable insights on the filter‐based regularization.
Sum of all Black–Scholes–Merton models: An efficient pricing method for spread, basket, and Asian options
Authors: Choi Jaehyuk
Published: March 2018

Contrary to the common view that exact pricing is prohibitive owing to the curse of dimensionality, this study proposes an efficient and unified method for pricing options under multivariate Black–Scholes–Merton (BSM) models, such as the basket, spread, and Asian options. The option price is expressed as a quadrature integration of analytic multi‐asset BSM prices under a single Brownian motion. Then the state space is rotated in such a way that the quadrature requires much coarser nodes than it would otherwise or low varying dimensions are reduced. The accuracy and efficiency of the method is illustrated through various numerical experiments.
Regional structural control on the distribution of world‐class gold deposits: An overview from the Giant Jiaodong Gold Province, China
Authors: Deng Jun , Yang Li‐Qiang , Li Rui‐Hong , Groves David I. , Santosh M. , Wang Zhong‐Liang , Sai Sheng‐Xun , Wang Si‐Rui
Published: March 2018

The Jiaodong gold province in northeastern China is the country's premier gold resource and globally one of the most important gold provinces. The late Early Cretaceous gold metallogeny in this belt remains an enigma as it is hosted in the Archean Jiaobei Terrane of the North China Block and, to a lesser extent, within the Palaeoproterozoic Sulu Terrane of the South China Block. The driving force for widespread Late Jurassic and Early Cretaceous granitic magmatism, the switchover from a compressional to extensional tectonic regime, and gold mineralization are considered to be a combination of plate subduction with lithospheric delamination and consequent asthenospheric upwelling. Although many aspects related to the genesis of the gold deposits in Jiaodong have been resolved, the spatial distribution of the world‐class gold deposits in this belt, which is of vital importance to brownfields and greenfields exploration, has been poorly understood in terms of the structural evolution of the province. In the northwestern segment of the Jiaobei Terrane, the world‐class gold deposits of Sanshandao in the west, through Jiaojia, to Linglong in the east define a broadly E–W corridor. This corridor links a series of east‐verging jogs on ore‐controlling NNE‐trending oblique‐slip faults that are subparallel to an lithospheric‐scale Tan‐Lu Fault to the west. There is cryptic evidence that these jogs line up in the E–W trend due to reactivation of Palaeoproterozoic to Mesozoic faults and folds that were part of the structural architecture of the terranes prior to the gold event. These jogs induced deviations in the local principal stresses relative to regional equivalent stresses, with resultant heterogeneous strain, increased rock permeability, and focussed ore‐fluid ingress. Both disseminated/microbreccia‐stockwork and vein‐type gold deposits formed in this corridor, with the former being predominant and the latter having a higher gold grade. In contrast, predominant vein‐type gold deposits in the eastern segment of the Jiaobei and Sulu terranes tend to form N–S corridors. These vein‐type ores may relate to rotational strain induced by movement on pairs of more linear NNE‐trending faults with the same kinematic movement sense.
Axoglial synapses are formed onto pioneer oligodendrocyte precursor cells at the onset of spinal cord gliogenesis
Authors: Osterstock Guillaume , Le Bras Barbara , Arulkandarajah Kalaimakan Hervé , Le Corronc Hervé , Czarnecki Antonny , Mouffle Christine , Bullier Erika , Legendre Pascal , Mangin Jean‐Marie
Published: March 2018

Virtually all oligodendrocyte precursors cells (OPCs) receive glutamatergic and/or GABAergic synapses that are lost upon their differentiation into oligodendrocytes in the postnatal and adult brain. Although OPCs are generated at mid‐embryonic stages, several weeks before the onset of myelination, it remains unknown when and where OPCs receive their first synapses and become susceptible to the influence of neuronal activity. In the embryonic spinal cord, neuro‐epithelial precursors in the pMN domain cease generating cholinergic motor neurons (MNs) to produce OPCs when the first synapses are formed in the ventral‐lateral marginal zone. We discovered that when the first synapses form onto MNs, axoglial synapses also form onto the processes of neuro‐epithelial precursors located in the marginal zone as they differentiate into OPCs. After leaving the neuro‐epithelium, these pioneer OPCs preferentially accumulate in the marginal zone where they are contacted by functional glutamatergic and GABAergic synapses. Spontaneous activity of these axoglial synapses was significantly potentiated by cholinergic signaling acting through presynaptic nicotinic acetylcholine receptors. Moreover, we discovered that chronic nicotine treatment significantly increases early OPC proliferation and density in the marginal zone. Our results demonstrate that OPCs are contacted by functional synapses as soon as they emerge from their precursor domain and that embryonic spinal cord colonization by OPCs can be regulated by cholinergic signaling acting onto these axoglial synapses.