bluuebunny/crossref_metadata_2025 huggingface dataset:
Marine Carbonate Component in the Mantle Beneath the Southeastern Tibetan Plateau: Evidence From Magnesium and Calcium Isotopes
Authors: Liu Fang , Li Xin , Wang Guiqin , Liu Yufei , Zhu Hongli , Kang Jinting , Huang Fang , Sun Weidong , Xia Xiaoping , Zhang Zhaofeng
Published: November 2017

Tracing and identifying recycled carbonates is a key issue to reconstruct the deep carbon cycle. To better understand carbonate subduction and recycling beneath the southeastern Tibetan Plateau, high‐K cal‐alkaline volcanic rocks including trachy‐basalts and trachy‐andesites from Tengchong were studied using Mg and Ca isotopes. The low δ26Mg (−0.31 ± 0.03‰ to −0.38 ± 0.03‰) and δ44/40Ca (0.67 ± 0.07‰ to 0.80 ± 0.04‰) values of these volcanic rocks compared to those of the mantle (−0.25 ± 0.07‰ and 0.94 ± 0.05‰, respectively) indicate the incorporation of isotopically light materials into the mantle source, which may be carbonate‐bearing sediments with low δ26Mg and δ44/40Ca values. In addition, no correlations of δ26Mg and δ44/40Ca with either SiO2 contents or trace element abundance ratios (e.g., Sm/Yb and Ba/Y) were observed, suggesting that limited Mg and Ca isotopic fractionation occurred during cal‐alkaline magmatic differentiation. A binary mixing model using Mg–Ca isotopes shows that 5–8% carbonates dominated primarily by dolostone were recycled back into the mantle. Since Tengchong volcanism is still active and probably related to ongoing plate tectonic movement, we propose that the recycled carbonates are derived from oceanic crust related to the ongoing subduction of the Indian plate.
Oceanographic Controls on the Variability of Ice‐Shelf Basal Melting and Circulation of Glacial Meltwater in the Amundsen Sea Embayment, Antarctica
Authors: Kimura Satoshi , Jenkins Adrian , Regan Heather , Holland Paul R. , Assmann Karen M. , Whitt Daniel B. , Van Wessem Melchoir , van de Berg Willem Jan , Reijmer Carleen H. , Dutrieux Pierre
Published: November 2017

Ice shelves in the Amundsen Sea Embayment have thinned, accelerating the seaward flow of ice sheets upstream over recent decades. This imbalance is caused by an increase in the ocean‐driven melting of the ice shelves. Observations and models show that the ocean heat content reaching the ice shelves is sensitive to the depth of thermocline, which separates the cool, fresh surface waters from warm, salty waters. Yet the processes controlling the variability of thermocline depth remain poorly constrained. Here we quantify the oceanic conditions and ocean‐driven melting of Cosgrove, Pine Island Glacier (PIG), Thwaites, Crosson, and Dotson ice shelves in the Amundsen Sea Embayment from 1991 to 2014 using a general circulation model. Ice‐shelf melting is coupled to variability in the wind field and the sea‐ice motions over the continental shelf break and associated onshore advection of warm waters in deep troughs. The layer of warm, salty waters at the calving front of PIG and Thwaites is thicker in austral spring (June–October) than in austral summer (December–March), whereas the seasonal cycle at the calving front of Dotson is reversed. Furthermore, the ocean‐driven melting in PIG is enhanced by an asymmetric response to changes in ocean heat transport anomalies at the continental shelf break: melting responds more rapidly to increases in ocean heat transport than to decreases. This asymmetry is caused by the inland deepening of bathymetry and the glacial meltwater circulation around the ice shelf.
Approximate Dispersion Relations for Waves on Arbitrary Shear Flows
Authors: Ellingsen S. Å. , Li Y.
Published: November 2017

An approximate dispersion relation is derived and presented for linear surface waves atop a shear current whose magnitude and direction can vary arbitrarily with depth. The approximation, derived to first order of deviation from potential flow, is shown to produce good approximations at all wavelengths for a wide range of naturally occuring shear flows as well as widely used model flows. The relation reduces in many cases to a 3‐D generalization of the much used approximation by Skop (1987), developed further by Kirby and Chen (1989), but is shown to be more robust, succeeding in situations where the Kirby and Chen model fails. The two approximations incur the same numerical cost and difficulty. While the Kirby and Chen approximation is excellent for a wide range of currents, the exact criteria for its applicability have not been known. We explain the apparently serendipitous success of the latter and derive proper conditions of applicability for both approximate dispersion relations. Our new model has a greater range of applicability. A second order approximation is also derived. It greatly improves accuracy, which is shown to be important in difficult cases. It has an advantage over the corresponding second‐order expression proposed by Kirby and Chen that its criterion of accuracy is explicitly known, which is not currently the case for the latter to our knowledge. Our second‐order term is also arguably significantly simpler to implement, and more physically transparent, than its sibling due to Kirby and Chen.
Azimuthal Ocean Wave Emerged in SAR Image Spectra Under Specific Condition
Authors: Yoshida T.
Published: November 2017

Velocity bunching causes nonlinear modulations in synthetic aperture radar (SAR) images of oceanic scenes. SAR images for the azimuth waves exhibit destructive wavy patterns because of azimuthal distortion caused by velocity bunching. Meanwhile, velocity bunching creates constructive wavy patterns for long waves in certain cases. This paper aims to provide a simple indication for practical interpretation of plausible wavy patterns. A numerical simulation had been performed to address how velocity bunching forms a clear wave‐like pattern caused by orbital motions of a long single swell under a certain condition. More specifically, when the azimuth shifts caused by the orbital motions of the azimuth wave concentrate in the wave trough or crest, the bunching causes a strong single peak in the SAR images. This paper explains the mechanism of displaying plausible wavy patterns from the viewpoint of the ocean wave spectra and this specific condition. First, the simulation was validated for irregular waves generated from ocean wave spectra matching actual buoy data from which SAR images were simultaneously obtained. The SAR image spectra showed longer waves than those of the ocean wave spectra estimated via buoy data. The simulated spectra exhibited a similar trend to the actual SAR image, thus validating the numerical simulation. Next, an additional numerical simulation was conducted for irregular waves under the specific condition. The simulated results suggest that if a significant wave height and wavelength match the specific condition, the long waves in SAR image spectra can be similar to the original ocean wave spectra.
Mesoscale Eddy Activity and Transport in the Atlantic Water Inflow Region North of Svalbard
Authors: Crews L. , Sundfjord A. , Albretsen J. , Hattermann T.
Published: November 2017

Mesoscale eddies are known to transport heat and biogeochemical properties from Arctic Ocean boundary currents to basin interiors. Previous hydrographic surveys and model results suggest that eddy formation may be common in the Atlantic Water (AW) inflow area north of Svalbard, but no quantitative eddy survey has yet been done for the region. Here vorticity and water property signatures are used to identify and track AW eddies in an eddy‐resolving sea ice‐ocean model. The boundary current sheds AW eddies along most of the length of the continental slope considered, from the western Yermak Plateau to 40°E, though eddies forming east of 20°E are likely more important for slope‐to‐basin transport. Eddy formation seasonality reflects seasonal stability properties of the boundary current in the eastern portion of the study domain, but on and immediately east of the Yermak Plateau enhanced eddy formation during summer merits further investigation. AW eddies tend to be anticyclonic, have radii close to the local deformation radius, and be centered in the halocline. They transport roughly 0.16 Sv of AW and, due to their warm cores, 1.0 TW away from the boundary current. These findings suggest eddies may be important for halocline ventilation in the Eurasian Basin, as has been shown for Pacific Water eddies in the Canadian Basin.
Dynamics of the Sediment Plume Over the Yangtze Bank in the Yellow and East China Seas
Authors: Luo Zhifa , Zhu Jianrong , Wu Hui , Li Xiangyu
Published: November 2017

A distinct sediment plume exists over the Yangtze Bank in the Yellow and East China Seas (YECS) in winter, but it disappears in summer. Based on satellite color images, there are two controversial viewpoints about the formation mechanism for the sediment plume. One viewpoint is that the sediment plume forms because of cross‐shelf sediment advection of highly turbid water along the Jiangsu coast. The other viewpoint is that the formation is caused by local bottom sediment resuspension and diffused to the surface layer through vertical turbulent mixing. The dynamic mechanism of the sediment plume formation has been unclear until now. This issue was explored by using a numerical sediment model in the present paper. Observed wave, current, and sediment data from 29 December 2016 to 16 January 2017 were collected near the Jiangsu coast and used to validate the model. The results indicated that the model can reproduce the hydrodynamic and sediment processes. Numerical experiments showed that the bottom sediment could be suspended by the bottom shear stress and diffuse to the surface layer by vertical mixing in winter; however, the upward diffusion is restricted by the strong stratification in summer. The sediment plume is generated locally due to bottom sediment resuspension primarily via tide‐induced bottom shear stress rather than by cross‐shelf sediment advection over the Yangtze Bank.
Microseisms Generated by Super Typhoon Megi in the Western Pacific Ocean
Authors: Lin Jianmin , Lin Jian , Xu Min
Published: November 2017

Microseisms generated by the super typhoon Megi (13–24 October 2010) were detected on both land‐based and island‐based seismic stations. We applied temporal frequency spectrum analysis to investigate the temporal evolution of the microseisms. When Megi was over the deep basins of the Philippine Sea, only weak microseisms with short‐period double frequency (SPDF, ∼0.20–0.40 Hz) were observed. However, after Megi traveled into the shallower waters of the South China Sea, microseisms with both long‐period double frequency (LPDF, ∼0.12–0.20 Hz) and SPDF were recorded. The excitation source regions of the microseisms were analyzed using seismic waveform records and synthetic modeling in frequency domain. Results reveal that part of the LPDF microseisms were excited in coastal source regions, while the intensity of both LPDF and SPDF microseisms correlated well with the distance from seismic stations to the typhoon center. Synthetic computations of equivalent surface pressure and corresponding microseisms show that the wave‐to‐wave interaction induced by coastal reflection has primary effects on microseismic frequency band of ∼0.10–0.20 Hz. The coastal generation of the dispersive LPDF microseisms is also supported by the observation of ocean swells induced by Megi through the images of C‐band ENVISAT‐ASAR satellite during its migration process. Two source regions of the microseisms during the life span of Megi are finally distinguished: One was mainly located in the left‐rear quadrant of the typhoon center that generated both LPDF and SPDF microseisms at shallow seas, while the other one was near the coasts that generated mostly LPDF microseisms.
Wind Forced Variability in Eddy Formation, Eddy Shedding, and the Separation of the East Australian Current
Authors: Bull Christopher Y. S. , Kiss Andrew E. , Jourdain Nicolas C. , England Matthew H. , van Sebille Erik
Published: November 2017

The East Australian Current (EAC), like many other subtropical western boundary currents, is believed to be penetrating further poleward in recent decades. Previous observational and model studies have used steady state dynamics to relate changes in the westerly winds to changes in the separation behavior of the EAC. As yet, little work has been undertaken on the impact of forcing variability on the EAC and Tasman Sea circulation. Here using an eddy‐permitting regional ocean model, we present a suite of simulations forced by the same time‐mean fields, but with different atmospheric and remote ocean variability. These eddy‐permitting results demonstrate the nonlinear response of the EAC to variable, nonstationary inhomogeneous forcing. These simulations show an EAC with high intrinsic variability and stochastic eddy shedding. We show that wind stress variability on time scales shorter than 56 days leads to increases in eddy shedding rates and southward eddy propagation, producing an increased transport and southward reach of the mean EAC extension. We adopt an energetics framework that shows the EAC extension changes to be coincident with an increase in offshore, upstream eddy variance (via increased barotropic instability) and increase in subsurface mean kinetic energy along the length of the EAC. The response of EAC separation to regional variable wind stress has important implications for both past and future climate change studies.
Modulation of the Ganges‐Brahmaputra River Plume by the Indian Ocean Dipole and Eddies Inferred From Satellite Observations
Authors: Fournier S. , Vialard J. , Lengaigne M. , Lee T. , Gierach M. M. , Chaitanya A. V. S.
Published: November 2017

The Bay of Bengal receives large amounts of freshwater from the Ganga‐Brahmaputra (GB) river during the summer monsoon. The resulting upper‐ocean freshening influences seasonal rainfall, cyclones, and biological productivity. Sparse in situ observations and previous modeling studies suggest that the East India Coastal Current (EICC) transports these freshwaters southward after the monsoon as an approximately 200 km wide, 2,000 km long “river in the sea” along the East Indian coast. Sea surface salinity (SSS) from the Soil Moisture Active Passive (SMAP) satellite provides unprecedented views of this peculiar feature from intraseasonal to interannual timescales. SMAP SSS has a 0.83 correlation and 0.49 rms‐difference to 0–5 m in situ measurements. SMAP and in stu data both indicate a SSS standard deviation of ∼0.7 to 1 away from the coast, that rises to 2 pss within 100 km of the coast, providing a very favorable signal‐to‐noise ratio in coastal areas. SMAP also captures the strong northern BoB, postmonsoon cross‐shore SSS contrasts (∼10 pss) measured along ship transects. SMAP data are also consistent with previous modeling results that suggested a modulation of the EICC/GB plume southward extent by the Indian Ocean Dipole (IOD). Remote forcing associated with the negative Indian Ocean Dipole in the fall of 2016 indeed caused a stronger EICC and “river in the sea” that extended by approximately 800 km further south than that in 2015 (positive IOD year). The combination of SMAP and altimeter data shows eddies stirring the freshwater plume away from the coast.
An Improved Triple Collocation Analysis Algorithm for Decomposing Autocorrelated and White Soil Moisture Retrieval Errors
Authors: Dong Jianzhi , Crow Wade T.
Published: November 2017

If not properly account for, autocorrelated retrieval errors can lead to inaccurate results in soil moisture data analysis and reanalysis. Here we propose a more generalized form of the triple collocation analysis algorithm (GTC) capable of decomposing the total error variance of remotely sensed surface soil moisture retrievals into their autocorrelated and the serially white components. Synthetic tests demonstrate the robustness and accuracy of GTC—even in the presence of significant temporal data gaps. However, the accuracy of GTC error autoregressive parameter estimates is relatively more sensitive to temporal data availability. In addition, land surface model soil moisture predictions collected from phase 2 of the North American Land Data Assimilation System and remotely sensed surface soil moisture retrievals obtained from the European Space Agency Climate Change Initiative (ESA CCI) are applied for a real data demonstration. Despite expectations to the contrary, significant error autocorrelation is found in the remotely sensed‐based ESA CCI soil moisture data sets. In particular, ESA CCI‐Act (i.e., the subset of ESA CCI soil moisture retrievals based on active scattomotter data) demonstrates the largest autoregressive parameters over low biomass areas. Conversely, ESA CCI‐Pas retrievals (based on passive radiometer data) have larger error autoregressive parameters over high biomass areas. As such, results clarify circumstances in which errors in remotely sensed surface soil moisture retrievals cannot be considered serially white.
Satellite Ocean Aerosol Retrieval (SOAR) Algorithm Extension to S‐NPP VIIRS as Part of the “Deep Blue” Aerosol Project
Authors: Sayer A. M. , Hsu N. C. , Lee J. , Bettenhausen C. , Kim W. V. , Smirnov A.
Published: November 2017

The Suomi National Polar‐Orbiting Partnership (S‐NPP) satellite, launched in late 2011, carries the Visible Infrared Imaging Radiometer Suite (VIIRS) and several other instruments. VIIRS has similar characteristics to prior satellite sensors used for aerosol optical depth (AOD) retrieval, allowing the continuation of space‐based aerosol data records. The Deep Blue algorithm has previously been applied to retrieve AOD from Sea‐viewing Wide Field‐of‐view Sensor (SeaWiFS) and Moderate Resolution Imaging Spectroradiometer (MODIS) measurements over land. The SeaWiFS Deep Blue data set also included a SeaWiFS Ocean Aerosol Retrieval (SOAR) algorithm to cover water surfaces. As part of NASA's VIIRS data processing, Deep Blue is being applied to VIIRS data over land, and SOAR has been adapted from SeaWiFS to VIIRS for use over water surfaces. This study describes SOAR as applied in version 1 of NASA's S‐NPP VIIRS Deep Blue data product suite. Several advances have been made since the SeaWiFS application, as well as changes to make use of the broader spectral range of VIIRS. A preliminary validation against Maritime Aerosol Network (MAN) measurements suggests a typical uncertainty on retrieved 550 nm AOD of order ±(0.03+10%), comparable to existing SeaWiFS/MODIS aerosol data products. Retrieved Ångström exponent and fine‐mode AOD fraction are also well correlated with MAN data, with small biases and uncertainty similar to or better than SeaWiFS/MODIS products.
Mathematical Modelling of Arctic Polygonal Tundra with Ecosys: 2. Microtopography Determines How CO2 and CH4 Exchange Responds to Changes in Temperature and Precipitation
Authors: Grant R. F. , Mekonnen Z. A. , Riley W. J. , Arora B. , Torn M. S.
Published: November 2017

Differences of surface elevation in arctic polygonal landforms cause spatial variation in soil water contents (θ), active layer depths (ALD), and thereby in CO2 and CH4 exchange. Here we test hypotheses in ecosys for topographic controls on CO2 and CH4 exchange in trough, rim, and center features of low‐ and flat‐centered polygons (LCP and FCP) against chamber and eddy covariance (EC) measurements during 2013 at Barrow, Alaska. Larger CO2 influxes and CH4 effluxes were measured with chambers and modeled with ecosys in LCPs than in FCPs and in lower features (troughs) than in higher (rims) within LCPs and FCPs. Spatially aggregated CO2 and CH4 fluxes from ecosys were significantly correlated with EC flux measurements. Lower features were modeled as C sinks (52–56 g C m−2 yr−1) and CH4 sources (4–6 g C m−2 yr−1), and higher features as near C neutral (−2–15 g C m−2 yr−1) and CH4 neutral (0.0–0.1 g C m−2 yr−1). Much of the spatial and temporal variations in CO2 and CH4 fluxes were modeled from topographic effects on water and snow movement and thereby on θ, ALD, and soil O2 concentrations. Model results forced with meteorological data from 1981 to 2015 indicated increasing net primary productivity in higher features and CH4 emissions in some lower and higher features since 2008, attributed mostly to recent rises in precipitation. Small‐scale variation in surface elevation causes large spatial variation of greenhouse gas (GHG) exchanges and therefore should be considered in estimates of GHG exchange in polygonal landscapes.
A putative curved DNA region upstream of rcsA in Escherichia coli plays a key role in transcriptional regulation by H‐NS
Authors: Meenakshi Shanmugaraja , Karthik Maruthan , Munavar M. Hussain
Published: November 2017

It is well established that in Escherichia coli, the histone‐like nucleoid structuring (H‐NS) protein also functions as negative regulator of rcsA transcription. However, the exact mode of regulation of rcsA transcription by H‐NS has not been studied extensively. Here, we report the multicopy effect of dominant‐negative hns alleles on the transcription of rcsA based on expression of cps‐lac transcriptional fusion in ∆lon, ∆lon rpoB12, ∆lon rpoB77 and lon+ strains. Our results indicate that H‐NS defective in recognizing curved DNA fails to repress rcsA transcription significantly, while nonoligomeric H‐NS molecules still retain the repressor activity to an appreciable extent. Together with bioinformatics analysis, our study envisages a critical role for the putative curved DNA region present upstream of rcsA promoter in the transcriptional regulation of rcsA by H‐NS.
Birth and death of a phantom
Authors: Dieguez Sebastian , Kaeser Mélanie , Roux Camille , Cottet Jérôme , Annoni Jean‐Marie , Schmidlin Eric
Published: November 2017

Patients with supernumerary phantom limb report experiencing an additional limb duplicating its physical counterpart, usually following a stroke with sensorimotor disturbances. Here, we report a short‐lasting case of a right upper supernumerary phantom limb with unusual visuomotor features in a healthy participant during a pure Jacksonian motor seizure unexpectedly induced by continuous Theta‐Burst Stimulation over the left primary motor cortex. Electromyographic correlates of the event followed the phenomenological pattern of sudden appearance and brutal dissolution of the phantom, adding credit to the hypothesis that supernumerary phantom limb results from a dynamic resolution of conflictual multimodal information.
Mechanical Properties in Metal–Organic Frameworks: Emerging Opportunities and Challenges for Device Functionality and Technological Applications
Authors: Burtch Nicholas C. , Heinen Jurn , Bennett Thomas D. , Dubbeldam David , Allendorf Mark D.
Published: November 2017

Some of the most remarkable recent developments in metal–organic framework (MOF) performance properties can only be rationalized by the mechanical properties endowed by their hybrid inorganic–organic nanoporous structures. While these characteristics create intriguing application prospects, the same attributes also present challenges that will need to be overcome to enable the integration of MOFs with technologies where these promising traits can be exploited. In this review, emerging opportunities and challenges are identified for MOF‐enabled device functionality and technological applications that arise from their fascinating mechanical properties. This is discussed not only in the context of their more well‐studied gas storage and separation applications, but also for instances where MOFs serve as components of functional nanodevices. Recent advances in understanding MOF mechanical structure–property relationships due to attributes such as defects and interpenetration are highlighted, and open questions related to state‐of‐the‐art computational approaches for quantifying their mechanical properties are critically discussed.
Solution Adsorption Formation of a π‐Conjugated Polymer/Graphene Composite for High‐Performance Field‐Effect Transistors
Authors: Liu Yun , Hao Wei , Yao Huiying , Li Shuzhou , Wu Yuchen , Zhu Jia , Jiang Lei
Published: November 2017

Semiconducting polymers with π‐conjugated electronic structures have potential application in the large‐scale printable fabrication of high‐performance electronic and optoelectronic devices. However, owing to their poor environmental stability and high‐cost synthesis, polymer semiconductors possess limited device implementation. Here, an approach for constructing a π‐conjugated polymer/graphene composite material to circumvent these limitations is provided, and then this material is patterned into 1D arrays. Driven by the π–π interaction, several‐layer polymers can be adsorbed onto the graphene planes. The low consumption of the high‐cost semiconductor polymers and the mass production of graphene contribute to the low‐cost fabrication of the π‐conjugated polymer/graphene composite materials. Based on the π‐conjugated system, a reduced π–π stacking distance between graphene and the polymer can be achieved, yielding enhanced charge‐transport properties. Owing to the incorporation of graphene, the composite material shows improved thermal stability. More generally, it is believed that the construction of the π‐conjugated composite shows clear possibility of integrating organic molecules and 2D materials into microstructure arrays for property‐by‐design fabrication of functional devices with large area, low cost, and high efficiency.
Optical Properties of 2D Semiconductor WS2
Authors: Cong Chunxiao , Shang Jingzhi , Wang Yanlong , Yu Ting
Published: November 2017

2D semiconductor tungsten disulfide (WS2) attracts significant interest in both fundamental physics and many promising applications such as light emitters, photodetectors/sensors, valleytronics, and flexible nanoelectronics, due to its fascinating optical, electronic, and mechanical properties. Herein, basic exciton properties of monolayer WS2 are reviewed including neutral excitons, charged excitons, bounded excitons, biexcitons, and the effects of electrostatic gating, chemical doping, strain, magnetic field, circular polarized light, and substrate on these excitonic structures. Besides basic excitonic emission, single‐photon emission, exciton–polaritons, and stimulated emission in monolayer WS2 are also discussed. The understanding of these optical phenomena is critical for the development of potential optical applications in electronic and optoelectronic devices. Finally, a summary and future prospective of the challengers and developments regarding 2D semiconductor WS2 is presented.
Potassium 2‐oxo‐3‐enoates as Effective and Versatile Surrogates for α, β‐Unsaturated Aldehydes in NHC‐Catalyzed Asymmetric Reactions
Authors: Gao Yaru , Ma Yafei , Xu Chen , Li Lin , Yang Tianjian , Sima Guoqing , Fu Zhenqian , Huang Wei
Published: November 2017

Potassium 2‐oxo‐3‐enoates, which are readily prepared at scale and easily stored, have been found to be effective and versatile surrogates for α,β‐unsaturated aldehydes in NHC‐catalyzed asymmetric reactions. Promoted by chiral N‐heterocyclic carbenes combined with LiCl, these easy‐to‐handle solid salts could release of CO2 and then undergo asymmetric reactions via homoenolate and α, β‐unsaturated acyl azolium intermediate. The reactions have broad substrate scopes with high enantioselectivities.

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Size‐Controlled Graphene Nanodot Arrays/ZnO Hybrids for High‐Performance UV Photodetectors
Authors: Tang Ruidie , Han Sancan , Teng Feng , Hu Kai , Zhang Zhiming , Hu Mingxiang , Fang Xiaosheng
Published: November 2017

Graphene nanodots (GNDs) are one of the most attractive graphene nanostructures due to their tunable optoelectronic properties. Fabricated by polystyrene‐nanosphere lithography, uniformly sized graphene nanodots array (GNDA) is constructed as an ultraviolet photodetector (PD) with ZnO nanofilm spin coated on it. The size of GNDA can be well controlled from 45 to 20 nm varying the etching time. It is revealed in the study that the photoelectric properties of ZnO/GNDA PD are highly GNDA size‐dependent. The highest responsivity (R) and external quantum efficiency of ZnO/GNDA (20 nm) PD are 22.55 mA W−1 and 9.32%, almost twofold of that of ZnO PD. Both ZnO/GNDA (20 nm) PD and ZnO/GNDA (30 nm) PD exhibit much faster response speed under on/off switching light and have shorter rise/decay time compared with ZnO PD. However, as the size of GNDA increase to 45 nm, the PD appears poor performance. The size‐dependent phenomenon can be explained by the energy band alignments in ZnO/GNDA hybrids. These efforts reveal the enhancement of GNDs on traditional photodetectors with tunable optoelectronic properties and hold great potential to pave a new way to explore the various remarkable photodetection performances by controlling the size of the nanostructures.
Assessment of cumulative health risk in the World Trade Center general responder cohort
Authors: Bello Ghalib A. , Teitelbaum Susan L. , Lucchini Roberto G. , Dasaro Christopher R. , Shapiro Moshe , Kaplan Julia R. , Crane Michael A. , Harrison Denise J. , Luft Benjamin J. , Moline Jacqueline M. , Udasin Iris G. , Todd Andrew C.
Published: November 2017

Background

Multiple comorbidities have been reported among rescue/recovery workers responding to the 9/11/2001 WTC disaster. In this study, we developed an index that quantifies the cumulative physiological burden of comorbidities and predicts life expectancy in this cohort.

Methods

A machine learning approach (gradient boosting) was used to model the relationship between mortality and several clinical parameters (laboratory test results, blood pressure, pulmonary function measures). This model was used to construct a risk index, which was validated by assessing its association with a number of health outcomes within the WTC general responder cohort.

Results

The risk index showed significant associations with mortality, self‐assessed physical health, and onset of multiple chronic conditions, particularly COPD, hypertension, asthma, and sleep apnea.

Conclusion

As an aggregate of several clinical parameters, this index serves as a cumulative measure of physiological dysregulation and could be utilized as a prognostic indicator of life expectancy and morbidity risk.
The clinical ultrasound report: Guideline for sonographers
Authors: Necas Martin
Published: November 2017

The reporting roles of sonographers in Australasia vary considerably. A large number of sonographers already routinely produce formal reports, while others are moving into clinical ultrasound roles where reporting is expected. This article summarises the best practice in reporting of ultrasound examinations based on international literature and addresses key topics including report structure, clinical content, style and language. Numerous examples and sample phrases are provided and common pitfalls are discussed.
Doppelt regioselektive asymmetrische C‐Allylierung von Isoxazolinonen: Iridium‐katalysierte N‐Allylierung mit nachfolgender Aza‐Cope‐Umlagerung
Authors: Rieckhoff Stefan , Meisner Jan , Kästner Johannes , Frey Wolfgang , Peters René
Published: November 2017

Isoxazolinone sind biologisch und synthetisch interessante, dicht funktionalisierte Heterocyclen, die lange Zeit nicht in enantiomerenangereicherter Form über asymmetrische Katalyse zugänglich waren. Neben dem Mangel an enantioselektiven Methoden ist die Funktionalisierung der Isoxazolinone oft durch Regioselektivitätsprobleme aufgrund der Konkurrenz mehrerer nukleophiler Zentren innerhalb der Heterocyclen erschwert. Hier beschreiben wir die erste regio‐ und enantioselektive C‐Allylierung von Isoxazolinonen. Diese verlief mit hoher Regioselektivität zugunsten eines linearen Allylierungsprodukts, obwohl Iridium‐Phosphoramidit‐Katalysatoren üblicherweise verzweigte Isomere bilden. Unsere Studien deuten darauf hin, dass dies eine Folge einer Reaktionskaskade ist. Eine anfängliche regio‐ und enantioselektive N‐Allylierung bildet ein verzweigtes Allylintermediat, und eine nachfolgende spontane [3,3]‐Umlagerung ermöglicht einen Chiralitätstransfer.
Double Regioselective Asymmetric C‐Allylation of Isoxazolinones: Iridium‐Catalyzed N‐Allylation Followed by an Aza‐Cope Rearrangement
Authors: Rieckhoff Stefan , Meisner Jan , Kästner Johannes , Frey Wolfgang , Peters René
Published: November 2017

Isoxazolinones are biologically and synthetically interesting densely functionalized heterocycles, which for a long time were not accessible in enantioenriched form by asymmetric catalysis. Next to the deficit of enantioselective methods, the functionalization of isoxazolinones is often plagued by regioselectivity issues due to the competition of various nucleophilic centers within the heterocycles. We report the first regio‐ and enantioselective C‐allylations of isoxazolinones. These occur with high regioselectivity in favor of the linear allylation products, although Ir phosphoramidite catalysts were used, which commonly results in branched isomers. Our studies suggest that this outcome is the result of a reaction cascade via an initial regio‐ and enantioselective N‐allylation to provide a branched allyl intermediate, followed by a spontaneous [3,3]‐rearrangement resulting in chirality transfer.
Synthesis, characterization and catalytic activity in Suzuki–Miyaura coupling of palladacycle complexes with n‐butyl‐substituted N‐heterocyclic carbene ligands
Authors: Fırıncı Rukiye , Emin Günay M. , Gökçe Aytaç G.
Published: November 2017

A series of monomeric palladacycle complexes bearing n‐butyl‐substituted N‐heterocyclic carbenes, namely [Pd(NHC)X(dmba)] (dmba: dimethylbenzylamine and [Pd(NHC)X(ppy)]; NHC: 1‐n‐butyl‐3‐substituted benzylimidazol‐2‐ylidene; ppy: 2‐phenylpyridine), were prepared either by transmetallation from the corresponding silver carbene complexes or by the reaction of the corresponding acetate‐bridged palladacycle dimer with N‐heterocyclic carbene ligands in high yields. The palladium(II) complexes were characterized using elemental analyses, APCI‐MS, 1H NMR and 13C NMR spectroscopies. These complexes are efficient in the Suzuki–Miyaura coupling reaction between phenylboronic acid and aryl bromides.
Degradation of Carbon Tetrachloride by nanoscale Zero‐Valent Iron @ magnetic Fe3O4: Impact of reaction condition, Kinetics, Thermodynamics and Mechanism
Authors: Lv Xiaofan , Li Hong , Ma Yiyang , Yang Hui , Yang Qi
Published: November 2017

Nano‐scale zero‐valent Iron (nZVI) attached on the Fe3O4 nanoparticles were prepared and creatively applied in the reductive dechlorination of Carbon Tetrachloride (CT). The characterization results of the synthesized composite indicated a main component of nZVI particles assembled on the surface of Fe3O4 with a layer of iron‐oxide film on the periphery, of which the dispersibility was better and the specific surface area was larger. The effects of different reaction conditions like temperature, initial pH values, Fe0@Fe3O4 dosage and initial CT concentrations on the removal of CT were evaluated. Under the optimum conditions, the Fe0@Fe3O4 composites showed a CT removal efficiency of 89.1% in 60 min, which was much greater than that of nZVI (61.7%) and Fe3O4 particles (14.3%). The removal process obeyed the pseudo‐first‐order kinetic model. Synergy effects of the constituents in the composite which can promote the relative rates of mass transfer to reactive sites were proposed to be existed and the magnetism of Fe3O4 could help to overcome the aggregation and surface passivation problem of nZVI. Thus, Fe0@Fe3O4 nanoparticles in our study can effectively complete the reductive dechlorination of CT and an improved nZVI catalyst is provided for the remediation of chlorinated organic compounds.
Magnetic‐based picolinaldehyde–melamine copper complex for the one‐pot synthesis of hexahydroquinolines via Hantzsch four‐component reactions
Authors: Khazaei Ardeshir , Mahmoudiani Gilan Maryam , Sarmasti Negin
Published: November 2017

A picolinaldehyde–melamine copper complex was loaded on a magnetic Fe3O4 core, so that it contained 0.33 mmol of Cu per gram, and was used as an efficient catalyst. The as‐synthesized catalyst was characterized using various techniques, including Fourier transform infrared spectroscopy, X‐ray diffraction, energy‐dispersive X‐ray spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry and thermogravimetric analysis. The catalyst was used to activate the raw materials in the synthesis of
hexahydroquinoline derivatives in one‐pot four‐component reactions. Low reaction time (minutes versus half an hour), solvent‐free condition and magnetically separable catalyst are some salient features of the developed catalyst. Also, the optimum amount of catalyst and temperature were determined as 0.07 g and 87.6 °C, respectively, which were obtained using response surface methodology and optimization techniques.
Ruthenium(II)–arene complexes of diimines: Effect of diimine intercalation and hydrophobicity on DNA and protein binding and cytotoxicity
Authors: Ganeshpandian Mani , Palaniandavar Mallayan , Muruganantham Amsaveni , Ghosh Swapan K. , Riyasdeen Anvarbatcha , Akbarsha Mohammad Abdulkader
Published: November 2017

A series of half‐sandwich Ru(II)–arene complexes [Ru(η6‐benzene)(diimine)Cl](PF6) (1–4), where diimine is 1,10‐phenanthroline (1), 5,6‐dimethyl‐1,10‐phenanthroline (2), dipyrido[3,2‐a:2′,3′‐c]phenazine (3) or 11,12‐dimethyldipyrido[3,2‐a:2′,3′‐c]phenazine (4), have been isolated and characterized using analytical and spectral methods. Complex 2 possesses a familiar pseudo‐octahedral ‘piano‐stool’ structure. The intrinsic DNA binding affinity of the complexes depends upon the diimine ligand: 3 (dppz) > 4 (11,12‐dmdppz) > 2 (5,6‐dmp) > 1 (phen). The π‐stacking interaction of extended planar ring of coordinated dppz (3) in between the DNA base pairs is more intimate than that of phen (1), and the incorporation of methyl groups on the dppz ring (4) discourages the stacking interaction leading to a lower DNA binding affinity for 4 than 3. Docking studies show that all the complexes bind in the major groove of DNA. Interestingly, 3 shows an ability to convert supercoiled DNA into nicked circular DNA even at 20 μM concentration beyond which complete oxidative DNA degradation is observed. The protein binding affinity of the complexes decreases in the order 4 > 3 > 2 > 1, and the higher protein binding affinity of 4 illustrates the strong involvement of methyl groups on dppz ring in hydrophobic interaction with protein. Also, 4 cleaves protein more efficiently than the other complexes in the presence of H2O2. It is notable that 2, 3 and 4 display cytotoxicity against human cervical cancer cell lines (SiHa) with potency higher than the currently used drug cisplatin. Acridine orange/ethidium bromide staining studies reveal that 3 induces apoptosis in cancer cells much more efficiently than 4.
Strategic Culture and Indonesian Maritime Security
Authors: Arif Muhamad , Kurniawan Yandry
Published: November 2017

Strategic culture plays a significant role in shaping current practices of maritime security in Indonesia. Rooted in the history and experiences of the military and the state itself, Indonesian maritime strategic culture shapes the perceived roles and responsibilities of the Indonesian primary and most capable maritime security agency, the Tentara Nasional Indonesia Angkatan Laut. Albeit institutional, doctrinal reform and weapons modernisation, the navy appears to be reluctant to relinquish its long‐standing law enforcement and internal security roles resulting in overlap of roles and responsibilities among the various maritime security agencies in Indonesia. This article argues that the historically shaped strategic culture, particularly the blurred distinction between ‘defence’ or sovereignty protection and ‘security’ or law enforcement, has not allowed the Tentara Nasional Indonesia Angkatan Laut to focus on the increasingly demanding traditional military roles. An understanding of Indonesian strategic history and culture as well as its civil‐military relations is thus essential to comprehend this problem.
Indian Ocean humpback dolphin (Sousa plumbea) movement patterns along the South African coast
Authors: Vermeulen Els , Bouveroux Thibaut , Plön Stephanie , Atkins Shanan , Chivell Wilfred , Cockcroft Vic , Conry Danielle , Gennari Enrico , Hörbst Sandra , James Bridget S. , Kirkman Stephen , Penry Gwenith , Pistorius Pierre , Thornton Meredith , Vargas‐Fonseca O. Alejandra , Elwen Simon H.
Published: November 2017

The Indian Ocean humpback dolphin was recently uplisted to ‘Endangered’ in the recent South African National Red List assessment. Abundance estimates are available from a number of localized study sites, but knowledge of movement patterns and population linkage between these sites is poor. A national research collaboration, the SouSA project, was established in 2016 to address this key knowledge gap. Twenty identification catalogues collected between 2000 and 2016 in 13 different locations were collated and compared.

Photographs of 526 humpback dolphins (all catalogues and photos) were reduced to 337 individuals from 12 locations after data selection. Of these, 90 matches were found for 61 individuals over multiple sites, resulting in 247 uniquely, well‐marked humpback dolphins identified in South Africa.

Movements were observed along most of the coastline studied. Ranging distances had a median value of 120 km and varied from 30 km up to 500 km. Long‐term site fidelity was also evident in the data. Dolphins ranging along the south coast of South Africa seem to form one single population at the western end of the species' global range.

Current available photo‐identification data suggested national abundance may be well below previous estimates of 1000 individuals, with numbers possibly closer to 500. Bearing in mind the poor conservation status of the species in the country, the development of a national Biodiversity Management Plan aimed at ensuring the long‐term survival of the species in South Africa is strongly recommended. At the same time, increased research efforts are essential, particularly to allow for an in‐depth assessment of population numbers and drivers of changes therein.

The present study clearly indicates the importance of scientific collaboration when investigating highly mobile and endangered species.
Synthesis, antitumor activity evaluation, and DNA‐binding study of coumarin‐based agents
Authors: Amin Kamilia M. , Taha Aly M. , George Riham F. , Mohamed Nada M. , Elsenduny Fardous F.
Published: November 2017

A novel series of coumarin‐thiadiazole heterocycle derivatives was synthesized by the nucleophilic substitution reaction. The synthesized compounds were structurally verified by IR, 1H NMR, 13C NMR, mass spectra, and elemental analyses. The antitumor activity of the synthesized compounds was evaluated through DNA binding assays and the 60‐cell line panel according to the US NCI‐DTP protocol or a selection of human tumor cell lines: breast cancer (MCF‐7), liver cancer (HepG‐2), and colorectal cancer (HCT‐116). Most of the compounds had better DNA/ethidium bromide fluorescence quenching rather than methyl green displacement, suggesting superior DNA intercalation over DNA groove binding. Compounds 8 and 14b showed the best quenching effect with KSV = 4.27 × 105 M−1. Moreover, the results for compounds 8, 4c, and 4e revealed a possible dual DNA binding mode with the intercalation to be superior, with KSV 4.27 × 105, 3.96 × 105, and 3.51 × 105 M−1, respectively, compared to 42%, 45%, and 43% methyl green displacement, respectively. Out of the 60‐cell line panel, the leukemia HL‐60 cell line was the most susceptible to growth inhibition when treated with 14a, resulting in 61% growth, followed by the lung carcinoma cell line NCI‐H522 showing 67% growth when treated with 9. Moreover, compound 10c had an IC50 value of 24.9 μg/mL against the HepG‐2 cell line.
Toward an anatomy of IR system component performances
Authors: Ferro Nicola , Silvello Gianmaria
Published: November 2017

Information retrieval (IR) systems are the prominent means for searching and accessing huge amounts of unstructured information on the web and elsewhere. They are complex systems, constituted by many different components interacting together, and evaluation is crucial to both tune and improve them. Nevertheless, in the current evaluation methodology, there is still no way to determine how much each component contributes to the overall performances and how the components interact together. This hampers the possibility of a deep understanding of IR system behavior and, in turn, prevents us from designing ahead which components are best suited to work together for a specific search task. In this paper, we move the evaluation methodology one step forward by overcoming these barriers and beginning to devise an “anatomy” of IR systems and their internals. In particular, we propose a methodology based on the General Linear Mixed Model (GLMM) and analysis of variance (ANOVA) to develop statistical models able to isolate system variance and component effects as well as their interaction, by relying on a grid of points (GoP) containing all the combinations of the analyzed components. We apply the proposed methodology to the analysis of two relevant search tasks—news search and web search—by using standard TREC collections. We analyze the basic set of components typically part of an IR system, namely, stop lists, stemmers, and n‐grams, and IR models. In this way, we derive insights about English text retrieval.
Recommending books to be exchanged online in the absence of wish lists
Authors: Pera Maria Soledad , Ng Yiu‐Kai
Published: November 2017

An online exchange system is a web service that allows communities to trade items without the burden of manually selecting them, which saves users' time and effort. Even though online book‐exchange systems have been developed, their services can further be improved by reducing the workload imposed on their users. To accomplish this task, we propose a recommendation‐based book exchange system, called EasyEx, which identifies potential exchanges for a user solely based on a list of items the user is willing to part with. EasyEx is a novel and unique book‐exchange system because unlike existing online exchange systems, it does not require a user to create and maintain a wish list, which is a list of items the user would like to receive as part of the exchange. Instead, EasyEx directly suggests items to users to increase serendipity and as a result expose them to items which may be unfamiliar, but appealing, to them. In identifying books to be exchanged, EasyEx employs known recommendation strategies, that is, personalized mean and matrix factorization, to predict book ratings, which are treated as the degrees of appeal to a user on recommended books. Furthermore, EasyEx incorporates OptaPlanner, which solves constraint satisfaction problems efficiently, as part of the recommendation‐based exchange process to create exchange cycles. Experimental results have verified that EasyEx offers users recommended books that satisfy the users' interests and contributes to the item‐exchange mechanism with a new design methodology.