bluuebunny/crossref_metadata_2025_split huggingface dataset:
An M component with a concurrent dart leader traveling along different paths during a lightning flash
Authors: Stolzenburg M. , Marshall T. C. , Karunarathne S. , Karunarathna N. , Orville R. E. 
Published: September 2015

AbstractUtilizing time‐correlated high‐speed video and electric field change data, a seven‐stroke lightning flash is described in which the fifth return stroke (RS) occurs 0.80 ms after the fourth RS connects to a different ground location 3.3 km away. The fifth RS is 0.34 ms after an M component starts down the different channel. The fifth stroke involves a dart leader traveling concurrently, though slower than the M component, in a prior channel to ground. There was no indication of leader advance along this path earlier during the fourth RS. The fourth stroke involves a stepped leader that started from the end of an observed prior dart leader branch which did not previously propagate to ground. The concurrent M component and dart leader are preceded by an in‐cloud event evidenced by a large‐amplitude, fast electric field change pulse, at 6.1 km estimated altitude, inferred as the connection to the channel for the M component. The M component current apparently initiates the dart leader about 40 µs later. A visible channel length of 10,400 m allows for the 2‐D propagation speed of the M component luminosity to be estimated in the range of 1.0 to 1.2 × 108 m s−1. The concurrent dart leader travels a visible length of 3445 m with 2‐D speed of 1.7 × 107 m s−1, similar to other dart leaders in this flash. Luminosity evolution along the channel through the RS and M component is also described. Estimated optical risetimes of three separate M components are 80–200 µs at 520 m above ground.
Effect of ions on sulfuric acid‐water binary particle formation: 2. Experimental data and comparison with QC‐normalized classical nucleation theory
Authors: Duplissy J. , Merikanto J. , Franchin A. , Tsagkogeorgas G. , Kangasluoma J. , Wimmer D. , Vuollekoski H. , Schobesberger S. , Lehtipalo K. , Flagan R. C. , Brus D. , Donahue N. M. , Vehkamäki H. , Almeida J. , Amorim A. , Barmet P. , Bianchi F. , Breitenlechner M. , Dunne E. M. , Guida R. , Henschel H. , Junninen H. , Kirkby J. , Kürten A. , Kupc A. , Määttänen A. , Makhmutov V. , Mathot S. , Nieminen T. , Onnela A. , Praplan A. P. , Riccobono F. , Rondo L. , Steiner G. , Tome A. , Walther H. , Baltensperger U. , Carslaw K. S. , Dommen J. , Hansel A. , Petäjä T. , Sipilä M. , Stratmann F. , Vrtala A. , Wagner P. E. , Worsnop D. R. , Curtius J. , Kulmala M. 
Published: September 2015

AbstractWe report comprehensive, demonstrably contaminant‐free measurements of binary particle formation rates by sulfuric acid and water for neutral and ion‐induced pathways conducted in the European Organization for Nuclear Research Cosmics Leaving Outdoor Droplets chamber. The recently developed Atmospheric Pressure interface‐time of flight‐mass spectrometer was used to detect contaminants in charged clusters and to identify runs free of any contaminants. Four parameters were varied to cover ambient conditions: sulfuric acid concentration (105 to 109 mol cm−3), relative humidity (11% to 58%), temperature (207 K to 299 K), and total ion concentration (0 to 6800 ions cm−3). Formation rates were directly measured with novel instruments at sizes close to the critical cluster size (mobility size of 1.3 nm to 3.2 nm). We compare our results with predictions from Classical Nucleation Theory normalized by Quantum Chemical calculation (QC‐normalized CNT), which is described in a companion paper. The formation rates predicted by the QC‐normalized CNT were extended from critical cluster sizes to measured sizes using the UHMA2 sectional particle microphysics model. Our results show, for the first time, good agreement between predicted and measured particle formation rates for the binary (neutral and ion‐induced) sulfuric acid‐water system. Formation rates increase with RH, sulfuric acid, and ion concentrations and decrease with temperature at fixed RH and sulfuric acid concentration. Under atmospheric conditions, neutral particle formation dominates at low temperatures, while ion‐induced particle formation dominates at higher temperatures. The good agreement between the theory and our comprehensive data set gives confidence in using the QC‐normalized CNT as a powerful tool to study neutral and ion‐induced binary particle formation in atmospheric modeling.
Controls on nitrous oxide production and consumption in reservoirs of the Ohio River Basin
Authors: Beaulieu Jake J. , Nietch Christopher T. , Young Jade L. 
Published: September 2015

AbstractAquatic ecosystems are a globally significant source of nitrous oxide (N2O), a potent greenhouse gas, but estimates are largely based on studies conducted in streams and rivers with relatively less known about N2O dynamics in reservoirs. Due to long water residence times and high nitrogen (N) loading rates, reservoirs support substantial N processing and therefore may be particularly important sites of N2O production. Predicting N2O emissions from reservoirs is difficult due to complex interactions between microbial N processing in the oxygen‐poor hypolimnion and oxygen‐rich epilimnion. Here we present the results of a survey of N2O depth profiles in 20 reservoirs draining a broad range of land use conditions in four states in the U.S. Nitrous oxide was supersaturated in the epilimnion of 80% of the reservoirs and was undersaturated in only one, indicating that reservoirs in this region are generally a source of N2O to the atmosphere. Nitrous oxide was undersaturated in the hypolimnion of 10 reservoirs, supersaturated in 9, and transitioned from supersaturation to undersaturation in 1 reservoir that was monitored periodically from midsummer to fall. All reservoirs with a mean hypolimnion nitrate concentration less than 50 µg N L−1 showed evidence of net N2O consumption in the hypolimnion. All reservoirs sampled during lake turnover supported N2O production throughout the water column. These results indicate that N2O dynamics in reservoirs differ widely both among systems and through time but can be predicted based on N and oxygen availability and degree of thermal stratification.
A Bistable Switch in Dynamic Thiodepsipeptide Folding and Template‐Directed Ligation
Authors: Mukherjee Rakesh , Cohen‐Luria Rivka , Wagner Nathaniel , Ashkenasy Gonen 
Published: September 2015

AbstractBistable reaction networks provide living cells with chemically controlled mechanisms for long‐term memory storage. Such networks are also often switchable and can be flipped from one state to the other. We target here a major challenge in systems chemistry research, namely developing synthetic, non‐enzymatic, networks that mimic such a complex function. Therefore, we describe a dynamic network that depending on initial thiodepsipeptide concentrations leads to one of two distinct steady states. This bistable system is readily switched by applying the appropriate stimuli. The relationship between the reaction network topology and its capacity to invoke bistability is then analyzed by control experiments and theory. We suggest that demonstrating bistable behavior using synthetic networks further highlights their possible role in early evolution, and may shine light on potential utility for novel applications, such as chemical memories.
The effects of on‐street parking on the service rate of nearby intersections
Authors: Cao Jin , Menendez Monica , Nikias Vasileios 
Published: September 2015

SummaryAn on‐street parking maneuver can often start a temporary bottleneck, leading to additional delay endured by the following vehicles. If the maneuver occurs near a signalized intersection, the service rate of the intersection might be reduced. In this paper, a model is built to analyze the effects of parking maneuvers on the intersection service rate. Based on the hydrodynamic theory of traffic flow, the perturbation caused by the parking maneuver is analyzed. Using dimensional analysis, we illustrate the relation between the background conditions, the distance from the parking area to the intersection, and the intersection service rate. Based on this relation, one can compute the service rate reduction caused by existing on‐street parking areas. A minimum distance between the parking area and the intersection to avoid such reduction can be accordingly found. Numerical examples based on empirical data from the city of Zurich, Switzerland, are provided to illustrate the practical applications. Although the analysis is based on streets with a single lane per direction, the findings can provide some insights regarding different situations. We hope such findings can be used as a basis for developing on‐street parking design guidelines. Copyright © 2015 John Wiley & Sons, Ltd.
Diversity in Reduction with Short‐Chain Dehydrogenases: Tetrahydroxynaphthalene Reductase, Trihydroxynaphthalene Reductase, and Glucose Dehydrogenase
Authors: Conradt David , Schätzle Michael A. , Husain Syed Masood , Müller Michael 
Published: September 2015

AbstractNAD(P)H‐dependent oxidoreductases from the short‐chain dehydrogenases/reductases (SDRs) family possess high functional diversity. Three SDRs, namely, tetrahydroxy‐ and trihydroxynaphthalene reductases (T4HNR, T3HNR) involved in the dihydroxynaphthalene‐melanin biosynthesis of the phytopathogenic fungus Magnaporthe grisea, and glucose dehydrogenase (GDH) from Bacillus subtilis, were characterized regarding their substrate range and functional behavior. T4HNR and T3HNR share activities towards the stereoselective reduction of 2‐tetralone derivatives and 2,3‐dihydro‐1,4‐naphthoquinones and show distinct but different stereochemical outcome in the case of epoxy‐1,4‐napthoquinones as substrates. GDH shares the activity towards 2,3‐dihydro‐1,4‐naphthoquinones, however, with low stereocontrol. Moreover, GDH reduces 2‐hydroxy‐2,3‐dihydro‐1,4‐naphthoquinone into trans‐4‐hydroxyscytalone with a high diastereomeric excess (96 %), whereas T4HNR gave the cis diastereomer (diastereomeric excess>99 %). Thus, SDRs provide a much higher functional and stereochemical diversity than previously thought, already exemplified by many transformations of three members of this enzyme family.
Efficient Counter Electrode Manufactured from Ag2S Nanocrystal Ink for Dye‐Sensitized Solar Cells
Authors: He Qingquan , Huang Shoushuang , Zai Jiantao , Tang Nianqi , Li Bo , Qiao Qiquan , Qian Xuefeng 
Published: September 2015

AbstractIt is generally believed that silver or silver‐based compounds are not suitable counter electrode (CE) materials for dye‐sensitized solar cells (DSSCs) due to the corrosion of the I−/I3− redox couple in electrolytes. However, Ag2S has potential applications in DSSCs for catalyzing I3− reduction reactions because of its high carrier concentration and tiny solubility product constant. In the present work, CE manufactured from Ag2S nanocrystals ink exhibited efficient electrocatalytic activity in the reduction of I3− to I− in DSSCs. The DSSC consisting of Ag2S CE displayed a higher power conversion efficiency of 8.40 % than that of Pt CE (8.11 %). Moreover, the devices also showed the characteristics of fast activity onset, high multiple start/stop capability and good irradiated stability. The simple composition, easy preparation, stable chemical property, and good catalytic performance make the developed Ag2S CE as a promising alternative to Pt CE in DSSCs.
Innovative Disulfide Esters of Dithiocarbamic Acid as Women‐Controlled Contraceptive Microbicides: A Bioisosterism Approach
Authors: Mandalapu Dhanaraju , Lal Nand , Kumar Lokesh , Kushwaha Bhavana , Gupta Sonal , Kumar Lalit , Bala Veenu , Yadav Santosh K. , Singh Pratiksha , Singh Nidhi , Maikhuri Jagdamba P. , Sankhwar Satya N. , Shukla Praveen K. , Siddiqi Imran , Gupta Gopal , Sharma Vishnu L. 
Published: September 2015

AbstractIn an ongoing effort to discover an effective, topical, dual‐function, non‐surfactant contraceptive vaginal microbicide, a novel series of 2,2′‐disulfanediylbis(3‐(substituted‐1‐yl)propane‐2,1‐diyl) disubstituted‐1‐carbodithioates were designed by using a bioisosterism approach. Thirty‐three compounds were synthesized, and interestingly, most demonstrated multiple activities: they were found to be spermicidal at a minimal effective concentration of 1–0.001 %, trichomonacidal against drug‐susceptible and resistant Trichomonas strains at minimal inhibitory concentration (MIC) ranges of 10.81–377.64 and 10.81–754.14 μM, respectively, and fungicidal at MIC 7.93–86.50 μM. These compounds were also found to be non‐cytotoxic to human cervical (HeLa) epithelial cells and vaginal microflora (Lactobacilli) in vitro. The most promising compound, 2,2′‐disulfanediylbis(3‐(pyrrolidin‐1‐yl)propane‐2,1‐diyl)dipyrrolidine‐1‐carbodithioate (5), exhibited spermicidal activity 15‐fold higher than that of the marketed spermicide Nonoxynol‐9 (N‐9) and also demonstrated microbicidal potency. To identify common structural features required for spermicidal activity, a 3D‐QSAR analysis was carried out, as well as in vivo efficacy studies and fluorescent labeling studies to determine the biological targets of compound 5.
Phase Transformations of Copper Sulfide Nanocrystals: Towards Highly Efficient Quantum‐Dot‐Sensitized Solar Cells
Authors: Liu Lige , Liu Chang , Fu Wenping , Deng Luogen , Zhong Haizheng 
Published: September 2015

AbstractOwing to their high electrical conductivity, tunable plasmonic absorption spectra, low cost, and abundance in nature, Cu2−xS nanocrystals are of great interest as functional materials for photovoltaic and photothermal applications. With the aim of developing low‐cost high‐efficiency quantum‐dot‐sensitized solar cells, solution‐processed Cu2−xS nanocrystal films are synthesized and their phase transformations upon thermal treatment are investigated. A combination of experimental results and theoretical analysis illustrates the thermodynamic evolution of the crystal structures and the composition caused by the thermal‐annealing process. The use of Cu2−xS nanocrystal films as counter electrodes in quantum‐dot‐sensitized solar cells is also explored. The devices have an optimized power‐conversion efficiency of 5.81 % for tetragonal Cu2S nanocrystal films that are derived from annealed Cu1.8S nanocrystal films.
Conspicuous male coloration impairs survival against avian predators in Aegean wall lizards, Podarcis erhardii
Authors: Marshall Kate L.A. , Philpot Kate E. , Stevens Martin 
Published: September 2015

AbstractAnimal coloration is strikingly diverse in nature. Within‐species color variation can arise through local adaptation for camouflage, sexual dimorphism and conspicuous sexual signals, which often have conflicting effects on survival. Here, we tested whether color variation between two island populations of Aegean wall lizards (Podarcis erhardii) is due to sexual dimorphism and differential survival of individuals varying in appearance. On both islands, we measured attack rates by wild avian predators on clay models matching the coloration of real male and female P. erhardii from each island population, modeled to avian predator vision. Avian predator attack rates differed among model treatments, although only on one island. Male‐colored models, which were more conspicuous against their experimental backgrounds to avian predators, were accordingly detected and attacked more frequently by birds than less conspicuous female‐colored models. This suggests that female coloration has evolved primarily under selection for camouflage, whereas sexually competing males exhibit costly conspicuous coloration. Unexpectedly, there was no difference in avian attack frequency between local and non‐local model types. This may have arisen if the models did not resemble lizard coloration with sufficient precision, or if real lizards behaviorally choose backgrounds that improve camouflage. Overall, these results show that sexually dimorphic coloration can affect the risk of predator attacks, indicating that color variation within a species can be caused by interactions between natural and sexual selection. However, more work is needed to determine how these findings depend on the island environment that each population inhabits.
Signatures of selection in the three‐spined stickleback along a small‐scale brackish water – freshwater transition zone
Authors: Konijnendijk Nellie , Shikano Takahito , Daneels Dorien , Volckaert Filip A.M. , Raeymaekers Joost A. M. 
Published: September 2015

AbstractLocal adaptation is often obvious when gene flow is impeded, such as observed at large spatial scales and across strong ecological contrasts. However, it becomes less certain at small scales such as between adjacent populations or across weak ecological contrasts, when gene flow is strong. While studies on genomic adaptation tend to focus on the former, less is known about the genomic targets of natural selection in the latter situation. In this study, we investigate genomic adaptation in populations of the three‐spined sticklebackGasterosteus aculeatusL. across a small‐scale ecological transition with salinities ranging from brackish to fresh. Adaptation to salinity has been repeatedly demonstrated in this species. A genome scan based on 87 microsatellite markers revealed only few signatures of selection, likely owing to the constraints that homogenizing gene flow puts on adaptive divergence. However, the detected loci appear repeatedly as targets of selection in similar studies of genomic adaptation in the three‐spined stickleback. We conclude that the signature of genomic selection in the face of strong gene flow is weak, yet detectable. We argue that the range of studies of genomic divergence should be extended to include more systems characterized by limited geographical and ecological isolation, which is often a realistic setting in nature.
PEGylated DOTA‐AHA‐Based GdIII Chelates: A Relaxometric Study
Authors: Fontes André , Karimi Shima , Helm Lothar , Ferreira Paula M. , André João P. 
Published: September 2015

AbstractThree PEGylated derivatives of 6‐amino‐2‐[4,7,10‐tris(carboxymethyl)‐1,4,7,10‐tetrazacyclododec‐1‐yl]hexanoic acid (DOTA‐AHA) with different molecular weights were prepared and characterized. Their GdIII chelates were studied in aqueous solution through variable‐temperature 1H nuclear magnetic relaxation dispersion (NMRD) and 17O NMR spectroscopy to determine their relaxivities and the parameters that govern them. The relaxivity varied from 5.1 to 6.5 mM–1 s–1 (37 °C and 60 MHz) as the molecular weight of the polyethylene glycol (PEG) chain increased and was slightly higher than that of the parent chelate Gd(DOTA‐AHA), owing to a small contribution of a slow global rotation of the complexes. A variable‐temperature 1H NMR spectroscopy study of several LnIII chelates of DOTA‐A(PEG750)HA allowed the determination of the isomeric M/m ratio (M = square‐antiprismatic isomer and m = twisted square‐antiprismatic isomer; the latter presents a much faster water exchange), which was estimated to be ca. 1:0.2 for the GdIII chelate, very close to that of [Gd(DOTA)]–. This explains why the PEGylated GdIII chelate has a water rate exchange similar to that of [Gd(DOTA)]–. The predominance of the M isomer is a consequence of the bulky PEG moiety, which does not favor the stabilization of the m isomer in sterically crowded systems at the substituent site, in contrast to what happens with less packed asymmetrical DOTA‐type chelates with substitution at one of the four acetate C(α) atoms.
Simplified cryopreservation of the microalga Chlorella vulgaris integrating a novel concept for cell viability estimation
Authors: Morschett Holger , Reich Sebastian , Wiechert Wolfgang , Oldiges Marco 
Published: September 2015

Microalgae currently receive growing attention as promising candidates for future bio‐economy concepts. However, the reliable maintenance of production strains remains challenging. The well‐established serial subculturing techniques suffer from low long‐time stability and high effort and are therefore stepwise being replaced by cryopreservation. Currently, available protocols are often deduced from cell culture technology and are rather complex. This study aimed to investigate if less complex approaches can be applied. We introduce an easy‐to‐use cryopreservation protocol based on the model organism Chlorella vulgaris. To overcome error‐prone viability estimation by plating techniques, an alternative method using growth pattern analysis was developed. As revealed by growth pattern analysis, the preservation of stationary phase cells proved superior to the commonly applied concept of freezing cells from the growing phase. Controlled‐rate cooling using simple devices resulted in reproducibly high post‐thawing viabilities in the range of 63 ± 2%. Moreover, the presented protocol highlights the potential of simplifying microalgal cryo‐preservation procedures, thereby reducing the required labor and material need to a minimum. Apart from the viability analysis of the cryopreserved microalga C. vulgaris, this approach seems to have the potential to be applied for other algae species and microorganisms, as well.
Comparing the effect of encapsulated and unencapsulated fennel extracts on the shelf life of minced common kilka (Clupeonella cultriventris caspia) and Pseudomonas aeruginosa inoculated in the mince
Authors: Bagheri Roya , Izadi Amoli Rabeeh , Tabari Shahndasht Nastaran , Shahosseini Seyed Rasoul 
Published: September 2015

AbstractThe quality of minced kilka (Clupeonella cultriventris caspia) with gum arabic encapsulated (0.3% and 0.5% w/w) and unencapsulated fennel extract (FE) (0.3% and 0.5% w/w) stored at 4°C was examined over a storage period of 15 days. The control and the treated fish samples were analyzed periodically for microbiological (total viable count [TVC] and total psychrotrophic count [TPC]) and chemical (peroxide value (PV) and total volatile nitrogen (TVB‐N)) parameters. Also the inhibitory effect of encapsulated and unencapsulated FE was evaluated against Pseudomonas aeruginosa, inoculated in minced kilka. According to the results, encapsulated FE samples showed the lowest amount of lipid oxidation and microbial deterioration during the storage period compared with the control and pure extract treatments. Although, the encapsulated FE at 0.5% showed drastic bacterial effect against Pseudomonas aeruginosa compared to others. Generally, gum arabic encapsulation could help to obtain higher antimicrobial and antioxidant activity in lower FE concentrations in minced fish.
Gene expression profiling of Mycobacterium tuberculosisLipoarabinomannan‐treated macrophages: A role of the Bcl‐2 family member A1 in inhibition of apoptosis in mycobacteria‐infected macrophages
Authors: Halder Priyanka , Kumar Ranjeet , Jana Kuladip , Chakraborty Sohini , Ghosh Zhumur , Kundu Manikuntala , Basu Joyoti 
Published: September 2015

AbstractMacrophages play an important role in the establishment of infection by intracellular pathogens. Mycobacterium tuberculosis is known to inhibit apoptosis and to downregulate immune responses of host cells using various strategies, including activation of peroxisome proliferator‐activated receptor (PPAR)γ. Mannose‐capped lipoarabinomannan (ManLAM) is one of the known bacterial effectors that plays a role in subversion of host immunity and activation of PPARγ. Here, we have used an unbiased global gene expression profiling approach to understand (a) how ManLAM regulates host cell immune responses and (b) the role of PPARγ in modulating ManLAM‐induced host cell signaling. We have demonstrated that ManLAM‐dependent inhibition of macrophage apoptosis is mediated by the upregulation of the antiapoptotic B‐cell CLL/lymphoma 2 (Bcl2) family member A1. Our in silico analyses suggested that ManLAM‐mediated PPARγ signaling is linked to important functions such as phagocytosis, cytoskeleton remodeling, cell survival, and autophagy. We have validated that ManLAM upregulates signal transducer and activator of transcription (STAT5)α, an important transcriptional regulator of cell survival in a PPARγ‐dependent manner. © 2015 IUBMB Life, 67(9):726–736, 2015