bluuebunny/crossref_metadata_2025 huggingface dataset:
Aggregate Earnings and (Un)employment Rate: Evidence from Nigeria
Authors: Odoemelam Ndubuisi , Grace Ofoegbu, N. , Regina Okafor, G.
Published: September 2019

The purpose of this study is to investigate the association between aggregate accounting earnings of quoted Nigerian firms and (un)employment changes. This study examined the influence of selected macroeconomic variables on the relationship between aggregate earnings and (un)employment change. This study analyzes aggregated earnings of 101 quoted firms and (un)employment rate data from the year 2006 to 2017. Aggregated earnings yearly observations were used in this study, with each yearly observation equal to the cross-sectional sum of sample firms’ yearly earnings. Results show that corporate aggregate earnings growth is (negatively) positively and significantly associate with (un)employment changes. Selected macroeconomic indicators statistically and significantly influence the aggregate earnings growth association with (un)employment changes. Robustness of our analysis in this study allowed us to document in strong terms that in an emerging economy, corporate aggregate earnings significantly associated with (un)employment (i.e., as corporate earnings increases, more investment will be made, and job seekers will be employed thereby reducing the unemployment rate). One implication of our results is that aggregate accounting earnings contain information about (un)employment changes in Nigeria. Our results suggest that effective monetary policies aimed at reducing inflation and interest rate as well as enabling economic policies encouraging and efficient mobilizing of fund from surplus side to deficit side of the economy will reduce unemployment and lead to employment.
Synthesis, Properties of a New (Polymer and Chalcone)
Authors: Attia Mohana Faroug
Published: September 2019

This paper included two objectives: (i) Synthesis of Polymer {poly 2- [1- phenyl -3-(4-methyl phenyl)-4, 5-dihydropyrazole-5-yl-(4-phenoxy carbonyl)] styrene} PMDPCS and structure characterized by FT-IR, 1H-NMR spectra and Uv/Vis and XRD. (ii) Synthesis of chalcone {3-(4-(dimethylamino) phenyl)-2-phenyl-(2E) propen-1-one} (DAPPP) for absorption and fluorescence spectra under different solvents and concentrations.  Also, under various concentrations, organic solvents and pump pulse energies of Nd: YAG laser, the amplified spontaneous emission (ASE) was studied. Additionally, under the same identical conditions, the amplified spontaneous emission spectra of DAPPP in solution were compared with a conventional laser dye of coumarin 503. Finally, the gain and the fluorescence quantum yield of DAPPP were determined.
Vehicular Fleet Expansion and Accidents Variation Numbers: A Contribution to the Analysis of the D. Pedro I-Tamoios Exporter Road Axis
Authors: Vernalha Estevão Brasil Ruas , Seixas Sônia Regina da Cal , Hoefel João Luiz de Moraes
Published: September 2019

Aims: This paper aims to analyse the evolution of the fleet of vehicles on the D. Pedro I Export Corridor Axis, in the period 1998-2016 and its potential relationship with vehicle accident mortality rates with two municipalities cut by this route - Atibaia and Caraguatatuba.

Study Design:  The focus was to investigate to what extent the intensification of the current fleet can be related as a factor directly responsible for the increase of the occurrence of accidents, using as an indicator for this measurement the mortality rate due to accidents of Traffic.

Place and Duration of Study: Study realized in São Paulo State, Brazil, for 36 months, from July 2015 to July 2018. The data used and analysed to diverse indicators were from 1998 to 2016.

Methodology: The methodology for the analysis of the intensification of the current fleet in the studied region was based on the comparison between the evolution figures of the fleets and the mortality rates due to transport accidents. In this way, all values were arranged on an identical horizontal axis (referring to the years), to show possible correlations.

Results: The relationship between the circulation fleet increase and the increase of accidents represents the negative impact of the processes of social and environmental changes that are occurring in the region. These processes link urbanisation, risks and vulnerability due to the lack of adequate urban planning and road safety infrastructure that exposes the population of these municipalities to a higher risk of accidents.

Conclusion: The data on the evolution of vehicle fleet in the exporting Corridor unequivocally evidences an accelerated urbanisation process, while mortality rates indicate the absence or inefficiency of public sector-oriented police and the health of the population, which hinder this process and may indicate negative impacts on society as a whole.
Geospatial Analysis of Groundwater Potential Zones in Keffi, Nassarawa State, Nigeria
Authors: Abdullahi D. R. , Oladosu O. O. , Samson S. A. , Abegunde L. O. , Balogun T. A. , Mzuyanda C.
Published: September 2019

Aim: Employ the use of Remote Sensing and Geographic Information System (GIS) to analyze areas of groundwater potentials in Keffi LGA to meet the rate of water demand.

Study Design:  The study is designed to delineate and analyze the drainage characteristics, and map out the groundwater potential zones.

Place and Duration of Study: The study is conducted in Keffi LGA of Nassarawa State, Nigeria in 2018.

Methodology: Both spatial and non-spatial data were utilized for this research, including Ground Control Points, satellite imageries, and maps. The data generated consisting of the rainfall, NDVI, lineament, geology, slope, and relief were prepared into thematic layers and used for the generation of the drainage morphometric parameters and multi-criteria overlay analysis. Each of the layer used has inputs were ranked based on their relative importance in controlling groundwater potential, and divided into classes using the hydro-geological properties. The groundwater potential analysis reveals four distinct zones representing high, moderate, less and least groundwater potential zones. The delineated groundwater potential map was verified using the available Ground Control Point of boreholes across the study area.

Results: The drainage of the study area falls in the 4th order, with the drainage density ranging from 0.2 to 1.6. From the groundwater potential map generated using the rainfall, lineament, geology, drainage density, slope, soil, and NDVI attributes, areas categorized having the moderate groundwater potentials cover about 89.1 km2, while the least cover 0.1 km2 of the study area.  Validating the result with borehole locations across the location shows that the boreholes are dug based on the availability of water following the groundwater potentials, and; 59.8% of the settlement area falls within the moderate groundwater potential classes.

Conclusion: The area has adequate capacity for water supply, and only those within the high groundwater potential classes can access groundwater throughout the year.
Optimal damper design strategy for braced structures based on generalized response spectrum analysis
Authors: Terazawa Yuki , Takeuchi Toru
Published: September 2019

This paper presents a damper design strategy for highly indeterminate 3D structures utilizing computational optimization and generalized response spectrum analysis, which is extended to incorporate non‐proportional damping. This enables a more efficient design process compared to trial‐and‐error with nonlinear response history analysis. The efficiency of the proposed design strategy is verified, analyzed and then applied to a series of illustrative examples including retrofit of an existing lattice tower structure and new build buckling‐restrained braced frames.
Progress of Photodetectors Based on the Photothermoelectric Effect
Authors: Lu Xiaowei , Sun Lin , Jiang Peng , Bao Xinhe
Published: September 2019

High‐performance uncooled photodetectors operating in the long‐wavelength infrared and terahertz regimes are highly demanded in the military and civilian fields. Photothermoelectric (PTE) detectors, which combine photothermal and thermoelectric conversion processes, can realize ultra‐broadband photodetection without the requirement of a cooling unit and external bias. In the last few decades, the responsivity and speed of PTE‐based photodetectors have made impressive progress with the discovery of novel thermoelectric materials and the development of nanophotonics. In particular, by introducing hot‐carrier transport into low‐dimensional material–based PTE detectors, the response time has been successfully pushed down to the picosecond level. Furthermore, with the assistance of surface plasmon, antenna, and phonon absorption, the responsivity of PTE detectors can be significantly enhanced. Beyond the photodetection, PTE effect can also be utilized to probe exotic physical phenomena in spintronics and valleytronics. Herein, recent advances in PTE detectors are summarized, and some potential strategies to further improve the performance are proposed.
On the Reversibility and Fragility of Sodium Metal Electrodes
Authors: Deng Yue , Zheng Jingxu , Warren Alexander , Yin Jiefu , Choudhury Snehashis , Biswal Prayag , Zhang Duhan , Archer Lynden A.
Published: September 2019

Metallic sodium is receiving renewed interest as a battery anode material because the metal is earth‐abundant, inexpensive, and offers a high specific storage capacity (1166 mAh g−1 at −2.71 V vs the standard hydrogen potential). Unlike metallic lithium, the case for Na as the anode in rechargeable batteries has already been demonstrated on a commercial scale in high‐temperature Na||S and Na||NiCl2 secondary batteries, which increases interest. The reversibility of room temperature sodium anodes is investigated in galvanostatic plating/stripping reactions using in situ optical visualization and galvanostatic polarization measurements. It is discovered that electronic disconnection of mossy metallic Na deposits (“orphaning”) is a dominant source of anode irreversibility in liquid electrolytes. The disconnection is shown by means of direct visualization studies to be triggered by a root‐breakage process during the stripping cycle. As a further step toward electrode designs that are able to accommodate the fragile Na deposits, electrodeposition of Na is demonstrated in nonplanar electrode architectures, which provide continuous and morphology agnostic access to the metal at all stages of electrochemical cycling. On this basis, nonplanar Na electrodes are reported, which exhibit exceptionally high levels of reversibility (Coulombic efficiency >99.6% for 1 mAh cm−2 Na throughput) in room‐temperature, liquid electrolytes.
Endowing Soft Photo‐Actuators with Intelligence
Authors: Hu Jing , Wang Wenzhong , Yu Haifeng
Published: September 2019

Stimuli‐responsive materials change their physical or chemical properties in response to external stimuli just like they have thoughts, which plays an important role in developing intelligent living systems for human beings. Thereto, recently developed soft photo‐actuators based on functional polymers demonstrate their capabilities of performing diverse mechanical movements, such as walking, swimming, and gripping, under the control of the light stimulus. Different from conventional electric power‐driven robots, soft photo‐actuators can complete the procedures of sensing light signals and converting them into mechanical work simultaneously without complex serial‐parallel circuits. They are promising candidates for soft robotics due to their advantages in miniaturization, controllability, and functionality. Herein, the progress of soft photo‐actuators regarding their materials structure and working mechanisms and the design strategy for a robust and intelligent system are elucidated. In addition, the significance of introducing self‐feedback loops to the actuator in realizing automatic and continuous motion is also emphasized. In future, soft photo‐actuators will be utilized in biomimetic or medical systems if their intelligent performances are further improved.
Photocatalytic BiVO4 Microswimmers with Bimodal Swimming Strategies
Authors: Heckel Sandra , Simmchen Juliane
Published: September 2019

Photocatalytic micromotors are developing rapidly and environmental applications seem very promising and within reach. However, the complex synthesis strategies, jointly with the large band gaps of most efficient swimmers inhibit both, applications and upscaling. Herein, a simple solvothermal synthesis of well defined, catalytically active BiVO4 microparticles, which can propel efficiently without asymmetrization is presented. Those microparticles respond to blue and UV light and are able to switch between different motion strategies, similar to bacterial microswimmers. These behavioral changes are controlled by changing the pH value of the environment.
Electrolyte Chemistry Enables Simultaneous Stabilization of Potassium Metal and Alloying Anode for Potassium‐Ion Batteries
Authors: Wang Hua , Yu Dandan , Wang Xiao , Niu Zhiqiang , Chen Mengxue , Cheng Liwei , Zhou Wei , Guo Lin
Published: September 2019

Alloying anodes are promising high‐capacity electrode materials for K‐ion batteries (KIBs). However, KIBs based on alloying anodes suffer from rapid capacity decay due to the instability of K metal and large volume expansion of alloying anodes. Herein, the effects of salts and solvents on the cycling stability of KIBs based on a typical alloying anode such as amorphous red phosphorus (RP) are investigated, and the potassium bis(fluorosulfonyl)imide (KFSI) salt‐based carbonate electrolyte is versatile to achieve simultaneous stabilization of K metal and RP electrodes for highly stable KIBs. This salt‐solvent complex with a moderate solvation energy can alleviate side reactions between K metal and the electrolyte and facilitate K+ ion diffusion/desolvation. Moreover, robust SEI layers that form on K metal and RP electrodes can suppress K dendrite growth and resist RP volume change. This strategy of electrolyte regulation can be applicable to other alloying anodes for high‐performance KIBs.
Particle‐in‐a‐Frame Nanostructures with Interior Nanogaps
Authors: Lee Seunghoon , Kim Jaeyoung , Yang Hyunwoo , Cortés Emiliano , Kang Seungwoo , Han Sang Woo
Published: September 2019

Designing plasmonic hollow colloids with small interior nanogaps would allow structural properties to be exploited that are normally linked to an ensemble of particles but within a single nanoparticle. Now, a synthetic approach for constructing a new class of frame nanostructures is presented. Fine control over the galvanic replacement reaction of Ag nanoprisms with Au precursors gave unprecedented Au particle‐in‐a‐frame nanostructures with well‐defined sub‐2 nm interior nanogaps. The prepared nanostructures exhibited superior performance in applications, such as plasmonic sensing and surface‐enhanced Raman scattering, over their solid nanostructure and nanoframe counterparts. This highlights the benefit of their interior hot spots, which can highly promote and maximize the electric field confinement within a single nanostructure.
Photostimulus‐Responsive Large‐Area Two‐Dimensional Covalent Organic Framework Films
Authors: Yu Fei , Liu Wenbo , Li Bang , Tian Dan , Zuo Jing‐Lin , Zhang Qichun
Published: September 2019

Using an external stimulus to modulate the electronic structure of covalent organic frameworks (COFs) is very important because such a response will endow them with additional functions. A two‐dimensional (2D) COF, constructed from a photo‐responsive unit (1,2‐bis(5‐formyl‐2‐methylthien‐3‐yl)cyclopentene), can reversibly switch its electrical conductivity 200 times from low state (the open form) to high state (the closed form) upon irradiation with UV light and reversible with visible light. This reversible phenomenon can be monitored through a circuit containing a light‐emitting diode (LED). Photoinduced ring‐closing/opening reactions do not destroy the integrity of the frameworks, and both processes follow logarithmic carrier generation with time. Moreover, the correlation between COFs electronic properties and changes in photoinduced kinetics and absorption curves has been demonstrated.
Interplay of Atomic Interactions in the Intermetallic Semiconductor Be5Pt
Authors: Amon Alfred , Svanidze Eteri , Ormeci Alim , König Marcus , Kasinathan Deepa , Takegami Daisuke , Prots Yurii , Liao Yen‐Fa , Tsuei Ku‐Ding , Tjeng Liu Hao , Leithe‐Jasper Andreas , Grin Yuri
Published: September 2019

Semiconducting substances form one of the most important families of functional materials. However, semiconductors containing only metals are very rare. The chemical mechanisms behind their ground‐state properties are only partially understood. Our investigations have rather unexpectedly revealed the semiconducting behaviour (band gap of 190 meV) for the intermetallic compound Be5Pt formed at a very low valence‐electron count. Quantum‐chemical analysis shows strong charge transfer from Be to Pt and reveals a three‐dimensional entity of vertex‐condensed empty Be4 tetrahedrons with multi‐atomic cluster bonds interpenetrated by the framework of Pt‐filled vertex‐condensed Be4 tetrahedrons with two‐atomic polar Be−Pt bonds. The combination of strong Coulomb interactions with relativistic effects results in a band gap.
Elaborating Complex Heteroaryl‐Containing Cycles via Enantioselective Palladium‐Catalyzed Cycloadditions
Authors: Trost Barry M. , Jiao Zhiwei , Hung Chao‐I. (Joey)
Published: September 2019

A general method for asymmetric synthesis of heteroaryl‐containing cycles via palladium‐catalyzed cyclization is reported. Most classes of nitrogen‐containing aromatics, including pyridines, quinolines, pyrimidines, various azoles and the derivatives of nucleobases are compatible substrates, offering various heteroaryl‐substituted cyclopentane, pyrrolidine, furanidine and bicyclo[4.3.1]decadiene derivatives with good to excellent enantioselectivity and diastereoselectivity.
Numerical investigation on the influence of nozzle–organization–mode of split burner on flow field distribution and combustion characteristics of a 300‐MWe subcritical down‐fired boiler
Authors: Du He , Zeng Lingyan , Liu Shuxuan , Li Xiaoguang , Yuan Zhenhua , Xie Cheng , Liu Wenjie , Yang Xiuchao , Chen Zhichao , Li Zhengqi
Published: September 2019

Numerical simulations are carried out to investigate the influence of burner nozzle–organization–mode (N–O–M) on flow field distribution and combustion characteristics of a 300‐MWe subcritical down‐fired boiler. Three typical N–O–Ms respectively designed with Mitsui Babcock Energy Limited (MBEL), fuel‐lean coal/air flow down‐setting (FD), and multi‐injection multistaging combustion (MIMSC) technology are studied, plus industrial‐size measurements on the original MBEL boiler. Vertical velocity attenuation index (η) and maximum dimensionless penetrating depth (γ) are introduced to estimate the transfer effect and penetrating capacity of pulverized coal/air flow. Results uncover that under the N–O–M based on MBEL technology, flow field and temperature field are deflective. η is 9.257. Under N–O–Ms based on FD and MIMSC technology, flow field and temperature field present obvious symmetry. η respectively are 4.365 and 2.921. γ are correspondingly about 0.8 and 1.36. Carbon content in fly ash and NOx emissions at furnace outlet are lowest (5.77% and 735.21 mg/m3 (O2 = 6%)) under the N–O–M with MIMSC technology. The bigger the η is, the worse penetrating characteristics of coal/air flow is, resulting in poor burnout of pulverized coal. Therefore, MIMSC technology is recommended for the boiler improvement, and η should be taken into account in the design of new down‐fired boiler N–O–Ms.
Pipeline Integrity Testing to Assess the Useful Life of Pipeline Infrastructure
Authors: Igar Karyn , Lauri Phil , Shoenberger Paul , Spencer David , Ellison Dan , Omae Amy
Published: September 2019

Key Takeaways

Mesa Water District found that a condition‐based program was a better option than age‐based estimates to determine the remaining useful life of its pipelines.

Asbestos–cement pipe was the primary focus of the testing program.

Mesa Water estimates that it will avoid spending $231 million in unnecessary pipe replacement over the next 30 years.
California's First Swimming Lake Using Recycled Water
Authors: Bourke Michael F. , Bunts Donald , Butler Patricia A.
Published: September 2019

Key Takeaways

From 1978 to 2016, Lake Mission Viejo was refilled in part with purchased drinking water, which has been controversial, especially during times of drought.

Lake Mission Viejo Association and Santa Margarita Water District executed a plan to fill the lake with recycled water to provide an environmentally sustainable, drought‐proof water supply.

The fast‐track project was a success as a result of careful planning, public outreach, innovative funding, and a tested treatment process.
Engineering of a Red Fluorogenic Protein/Merocyanine Complex for Live‐Cell Imaging
Authors: Santos Elizabeth M. , Berbasova Tetyana , Wang Wenjing , Salmani Rahele Esmatpour , Sheng Wei , Vasileiou Chrysoula , Geiger James H. , Borhan Babak
Published: September 2019

A reengineered human cellular retinol binding protein II (hCRBPII), a 15‐kDa protein belonging to the intracellular lipid binding protein (iLBP) family, generates a highly fluorescent red pigment through the covalent linkage of a merocyanine aldehyde to an active site lysine residue. The complex exhibits “turn‐on” fluorescence, due to a weakly fluorescent aldehyde that “lights up” with subsequent formation of a strongly fluorescent merocyanine dye within the binding pocket of the protein. Cellular penetration of merocyanine is rapid, and fluorophore maturation is nearly instantaneous. The hCRBPII/merocyanine complex displays high quantum yield, low cytotoxicity, specificity in labeling organelles, and compatibility in both cancer cell lines and yeast cells. The hCRBPII/merocyanine tag is brighter than most common red fluorescent proteins.
The Development of Biophotovoltaic Systems for Power Generation and Biological Analysis
Authors: Wey Laura T. , Bombelli Paolo , Chen Xiaolong , Lawrence Joshua M. , Rabideau Clayton M. , Rowden Stephen J. L. , Zhang Jenny Z. , Howe Christopher J.
Published: September 2019

Biophotovoltaic systems (BPVs) resemble microbial fuel cells, but utilise oxygenic photosynthetic microorganisms associated with an anode to generate an extracellular electrical current, which is stimulated by illumination. Study and exploitation of BPVs have come a long way over the last few decades, having benefited from several generations of electrode development and improvements in wiring schemes. Power densities of up to 0.5 W m−2 and the powering of small electrical devices such as a digital clock have been reported. Improvements in standardisation have meant that this biophotoelectrochemical phenomenon can be further exploited to address biological questions relating to the organisms. Here, we aim to provide both biologists and electrochemists with a review of the progress of BPV development with a focus on biological materials, electrode design and interfacial wiring considerations, and propose steps for driving the field forward.
Effect of sintering temperature of potassium feldspar‐limestone/dolomite on composition and microstructure of silicate fertilizers
Authors: Li Xiaoyan , Yu Weimin , Zhao Bingqiang
Published: September 2019

Acid soils call for a fertilizer providing base cations (Ca, Mg, K, et al.) and releasing nutrients with a gradual rate. The dissolution rate from soil minerals such as potassium feldspar (KAlSi3O8) is believed to be too slow to provide agronomic benefits. Using limestone (CaCO3) and/or dolomite (CaMg(CO3)2) as the additives, crystalline structure breakdown of potassium feldspar is achieved by high‐temperature treatment and a K‐containing multi‐nutrient silicate fertilizer is thus produced. Effect of sintering temperature on the available nutrient contents, mineral phases, and microstructure was investigated. The evolution of K‐containing minerals and their relative dissolution rate were discussed. The dissolution behaviors of other calcium/magnesium silicates were also analyzed. After sintered at 1220°C, the plant‐available Si, Ca, K, and Mg contents in the fertilizer were 15.1%, 21.6%, 5.4%, and 2.4%, with the proportion of 45% potassium feldspar, 33% limestone, and 22% dolomite. Kalsilite (KAlSiO4) was proved to be the most effective one among potassium feldspar (KAlSi3O8), leucite (KAlSi2O6), and kalsilite (KAlSiO4), which was totally soluble after 30 minutes extraction in 0.5 mol/L HCl acid. Pseudwollastonite (Ca3Si3O9) was totally soluble while gehlenite (Ca2Al2SiO7) and akermanite (Ca2MgSi2O7) could only be dissolved after extraction of several times. Chemical reaction processes between KAlSi3O8 and CaO/MgO were discussed, and dicalcium silicate (Ca2SiO4, C2S) should be avoided in the reaction system.
Molecular Flexibility and Bend in Semi‐Rigid Liquid Crystals: Implications for the Heliconical Nematic Ground State
Authors: Mandle Richard J. , Goodby John W.
Published: September 2019

The NTB phase phases possess a local helical structure with a pitch length of a few nanometers and is typically exhibited by materials consisting of two rigid mesogenic units linked by a flexible oligomethylene spacer of odd parity, giving a bent shape. We report the synthesis and characterisation of two novel dimeric liquid crystals, and perform a computational study on 10 cyanobiphenyl dimers with varying linking groups, generating a large library of conformers for each compound; this allows us to present molecular bend angles as probability weighted averages of many conformers, rather than use a single conformer. We validate conformer libraries by comparison of interproton distances with those obtained from solution‐based 1D 1H NOESY NMR, finding good agreement between experiment and computational work. Conversely, we find that using any single conformer fails to reproduce experimental interproton distances. We find the use of a single conformer significantly overestimates the molecular bend angle while also ignoring flexibility; in addition, we show that the average bend angle and flexibility are both linked to the relative stability of the NTB phase.
Small Structural Differences between Two Ferrocenyl Diphenols Determine Large Discrepancies of Reactivity and Biological Effects
Authors: Tonolo Federica , Salmain Michèle , Scalcon Valeria , Top Siden , Pigeon Pascal , Folda Alessandra , Caron Benoit , McGlinchey Michael J. , Toillon Robert‐Alain , Bindoli Alberto , Jaouen Gérard , Vessières Anne , Rigobello Maria Pia
Published: September 2019

The ferrocenyl diphenol complexes 1,1‐bis(4′‐hydroxyphenyl)‐2‐ferrocenyl‐but‐1‐ene (1) and 1,2‐bis(4′‐hydroxyphenyl)‐1‐ferrocenyl‐but‐1‐ene [(Z)‐2], which differ by the relative position of the two phenolic substituents, display dramatically different antiproliferative activities on cancer cells (1is far more cytotoxic than2). In this study, our goal was to discover the origin of this difference by comparing their reactivity and biological behaviour. In terms of common behaviour, we found that1and2are both efficient inhibitors of thioredoxin reductase (TrxR) in vitro after oxidation by a horseradish peroxidase/H2O2system. However, as1is only a moderate inhibitor of TrxR in MDA‐MB‐231 cells, TrxR is probably not the major target responsible for the cytotoxicity of1. In terms of differences, we noted that1induced a significant redox imbalance characterised by lipid peroxidation and thiol oxidation, and a moderate decrease of the mitochondrial membrane potential in breast cancer cells, whereas2has almost no effect. These results underline the importance of thetransconfiguration in the ferrocenyl–double bond–phenol motif, which is present in1but iscisin (Z)‐2.
The presence of helical flow can suppress areas of disturbed shear in parameterised models of an arteriovenous fistula
Authors: Cunnane Connor V. , Cunnane Eoghan M. , Moran Daniel T. , Walsh Michael T.
Published: September 2019

Areas of disturbed shear that develop following arteriovenous fistula (AVF) creation are believed to trigger the onset of intimal hyperplasia (IH), leading to AVF dysfunction. The presence of helical flow can suppress the flow disturbances that lead to disturbed shear in other areas of the vasculature. However, the relationship between helical flow and disturbed shear remains unevaluated in AVF. In this study, computational fluid dynamics (CFD) is used to evaluate the relationship between geometry, helical flow, and disturbed shear in parameterised models of an AVF characterised by four different anastomosis angles. The AVF models with a small anastomosis angle demonstrate the lowest distribution of low/oscillating shear and are characterised by a high helical intensity coupled with a strong balance between helical structures. Contrastingly, the models with a large anastomosis angle experience the least amount of high shear, multidirectional shear, as well as spatial and temporal gradients of shear. Furthermore, the intensity of helical flow correlates strongly with curvature (r = 0.73, P < .001), whereas it is strongly and inversely associated with taper (r = −0.87, P < .001). In summary, a flow field dominated by a high helical intensity coupled with a strong balance between helical structures can suppress exposure to low/oscillating shear but is ineffective when it comes to other types of shear. This highlights the clinical potential of helical flow as a diagnostic marker of exposure to low/oscillating shear, as helical flow can be identified in vivo with the use of ultrasound imaging.
Hierarchical Self‐Assembly of Tetrakis(1‐pyrenyl)porphyrins into Microscopic Petals and Flowers with Ultrasensitive Room‐Temperature NO2 Sensing in a Broad Humidity Range
Authors: Sun Qiqi , Liu Qi , Gong Lei , Wang Chiming , Kong Xia , Yang Chaoyi , Feng Weigang , Qi Dongdong , Dai Fangna , Li Xiyou , Chen Yanli
Published: September 2019

A metal free meso‐tetrakis(1‐pyrenyl)porphyrin H2T[(Pyr)4]P (1) and its cobalt congener CoT[(Pyr)4]P (2) are firstly fabricated into the hierarchical nanopetals and micro‐ball‐flowers, respectively, by a simple solution‐based method. Unexpectedly highly sensitive, stable, selective and reproducible responses to 50–400 ppb NO2 gas are obtained at room temperature for the aggregates of both 1 and 2, within 2 min dynamic exposure period at a broad relative humidity (RH) range of 0%‐75%. In particular, the micro‐ball‐flowers of 2 achieve a sensitivity of 91.4 and 214% ppm−1 at 45% RH and 75% RH, respectively, demonstrating the potentials as chemical sensors operating in real‐world atmospheres. Furthermore, the sensitivity of 1 and 2 remains almost unchanged under 0%–75% RH after 6 months. The present work represents one of the best results among organic‐based ppb‐level NO2 sensors operating under a broad RH range in terms of sensitivity and stability to humidity variations at room temperature.
Selective Cellulose Hydrogenolysis to Ethanol Using Ni@C Combined with Phosphoric Acid Catalysts
Authors: Liu Qiying , Wang Haiyong , Xin Haosheng , Wang Chenguang , Yan Long , Wang Yingxiong , Zhang Qi , Zhang Xinghua , Xu Ying , Huber George W. , Ma Longlong
Published: September 2019

Invited for this month′s cover is the group of Longlong Ma at the Guangzhou Institute of Energy Conversion, CAS. The Front Cover shows the conversion of renewable biomass into cellulosic ethanol in water over Ni@C catalyst under mild conditions. In this work, a new one‐pot method is developed for production of ethanol from renewable and sustainable cellulose. With the aid of Ni@C catalyst and H3PO4, cellulose is directly converted into ethanol with high yield of 69.1 %, and an ethanol concentration up to 89 g L−1. The Full Paper itself is available at 10.1002/cssc.201901110.
Differential responses of amphibian and reptile assemblages to size of riparian buffers within managed forests
Authors: Guzy Jacquelyn C. , Halloran Kelly M. , Homyack Jessica A. , Thornton‐Frost Jamie E. , Willson John D.
Published: September 2019

Streamside management zones (i.e., riparian buffers;SMZs) are commonly implemented within managed forests to protect water quality but may also provide habitat for riparian‐associated wildlife. Yet, little research has rigorously addressed the value ofSMZs for wildlife, particularly for cryptic species such as amphibians and reptiles. Previous studies of herpetofauna withinSMZs have focused on one or a few stream‐associated species, and questions remain regarding variation among species or guilds and what roleSMZs serve toward conservation of herpetofaunal diversity in managed forests. However, recent statistical advances have improved our ability to analyze large multi‐species presence–absence data sets, accounting for low detection rates typical for some herpetofaunal species. Our study represents an extensive landscape‐scale examination of herpetofaunal communities withinSMZs using a multi‐species occupancy approach. We conducted four replicate surveys at 102 headwater streams, spanning a gradient ofSMZwidths and adjacent forest stand ages, within the Ouachita Mountains, Arkansas,USA. We used a hierarchical Bayesian community occupancy model to estimate species richness and species‐specific occupancy responses toSMZand overstory characteristics, accounting for variation in occupancy and detection attributable to site and sampling covariates. We documented high richness (37 species) withinSMZs. Across the herpetofaunal community, occupancy and species richness were consistently positively associated withSMZwidth, with maximum predicted richness of 30 species occurring at sites with buffers extending 51 m on either side of the stream. However, we documented considerable variation among groups and species within groups, underscoring the potential for different responses to forest management among taxa. Reptile predicted richness increased more rapidly up toSMZs of ~35 m, whereas maximum salamander predicted richness was not seen until anSMZwidth of 55 m. Estimated salamander richness was highest withinSMZs embedded in mature managed pine stands and was higher inSMZs comprised of a deciduous or mixed overstory vs. a pine overstory. Compared to salamanders, more anuran species showed high mean estimated occupancy (>75%) at narrowerSMZs (<30 m). Collectively, our results indicate thatSMZs surrounding small first‐order streams in intensively managed forests not only protect water quality, but also can support diverse amphibian and reptile communities.
Fire‐mediated habitat change regulates woodland bird species and functional group occurrence
Authors: Gosper Carl R. , Watson Simon J. , Fox Elizabeth , Burbidge Allan H. , Craig Michael D. , Douglas Tegan K. , Fitzsimons James A. , McNee Shapelle , Nicholls A. O. , O'Connor James , Prober Suzanne M. , Watson David M. , Yates Colin J.
Published: September 2019

In an era characterized by recurrent large wildfires in many parts of the globe, there is a critical need to understand how animal species respond to fires, the rates at which populations can recover, and the functional changes fires may cause. Using quantified changes in habitat parameters over a ~400‐yr post‐fire chronosequence in an obligate‐seeding Australian eucalypt woodland, we build and test predictions of how birds, as individual species and aggregated into functional groups according to their use of specific habitat resources, respond to time since fire. Individual bird species exhibited four generalized response types to time since fire: incline, decline, delayed, and bell. All significant relationships between bird functional group richness or abundance and time since fire were consistent with predictions based on known time‐since‐fire‐associated changes in habitat features putatively important for these bird groups. Consequently, we argue that the bird community is responding to post‐fire successional changes in habitat as per the habitat accommodation model, rather than to time since fire per se, and that our functional framework will be of value in predicting bird responses to future disturbances in this and other obligate‐seeder forest and woodland ecosystems. Most bird species and functional groups that were affected by time since fire were associated with long‐unburned woodlands. In the context of recent large, stand‐replacement wildfires that have affected a substantial proportion of obligate‐seeder eucalypt woodlands, and the multi‐century timescales over which post‐fire succession occurs, it would appear preferable from a bird conservation perspective if fires initiating loss of currently long‐unburned woodlands were minimized. Once long‐unburned woodlands are transformed by fire into recently burned woodlands, there is limited scope for alternative management interventions to accelerate the rate of habitat development after fire, or supplement the resources formerly provided to birds by long‐unburned woodlands, with the limited exception of augmenting hollow availability for key hollow‐nesting species.
Reproductive skew in cooperative breeding: Environmental variability, antagonistic selection, choice, and control
Authors: Nonacs Peter
Published: September 2019

A multitude of factors may determine reproductive skew among cooperative breeders. One explanation, derived from inclusive fitness theory, is that groups can partition reproduction such that subordinates do at least as well as noncooperative solitary individuals. The majority of recent data, however, fails to support this prediction; possibly because inclusive fitness models cannot easily incorporate multiple factors simultaneously to predict skew. Notable omissions are antagonistic selection (across generations, genes will be in both dominant and subordinate bodies), constraints on the number of sites suitable for successful reproduction, choice in which group an individual might join, and within‐group control or suppression of competition. All of these factors and more are explored through agent‐based evolutionary simulations. The results suggest the primary drivers for the initial evolution of cooperative breeding may be a combination of limited suitable sites, choice across those sites, and parental manipulation of offspring into helping roles. Antagonistic selection may be important when subordinates are more frequent than dominants. Kinship matters, but its main effect may be in offspring being available for manipulation while unrelated individuals are not. The greater flexibility of evolutionary simulations allows the incorporation of species‐specific life histories and ecological constraints to better predict sociobiology.
Framework for using downscaled climate model projections in ecological experiments to quantify plant and soil responses
Authors: Owen Rachel K. , Webb Elisabeth B. , Goyne Keith W. , Svoma Bohumil M. , Gautam Sagar
Published: September 2019

Soil and plant responses to climate change can be quantified in controlled settings. However, the complexity of climate projections often leads researchers to evaluate ecosystem response based on general trends, rather than specific climate model outputs. Climate projections capture spatial and temporal climate extremes and variability that are lost when using mean climate trends. In addition, application of climate projections in experimental settings remains limited. Our objective was to develop a framework to incorporate statistically downscaled climate model projections into the design of temperature and precipitation treatments for ecological experiments. To demonstrate the utility of experimental treatments derived from climate projections, we used wetlands in the Great Plains as a model ecosystem for evaluating plant and soil responses. Spatial and temporal projections were selected to capture variability and intensity of projected future conditions for exemplary purposes. To illustrate climate projection application for ecological experiments, we developed temperature and precipitation treatments based on moderate‐emissions scenario climate outputs (i.e.,RCP4.5–650 ppmCO2equivalent). Our temperature treatments captured weekly trends that represented cool, average, and warm temperature predictions, and our daily precipitation treatments mimicked various seasonal precipitation trends and extreme events projected for the late 21st century. Treatments were applied to two short‐term controlled experiments evaluating (1) plant germination (temperature treatment applied in growth chamber) and (2) soil nitrogen cycling (precipitation treatment applied in greenhouse) responses to projected future conditions in the Great Plains. Our approach provides flexibility for selecting appropriate and precise climate model outputs to design experimental treatments. Using these techniques, ecologists can better incorporate variation in climate model projections for experimentally evaluating ecosystem responses to future climate conditions, reduce uncertainty in predictive ecological models, and apply predicted outcomes when making management and policy decisions.
Tri‐trophic interactions mediate the spread of a vector‐borne plant pathogen
Authors: Clark Robert E. , Basu Saumik , Lee Benjamin W. , Crowder David W.
Published: September 2019

Many insect herbivores are vectors that transmit plant pathogens as they forage. Within food webs, vectors interact with a range of host plants, other herbivores, and predators. Yet, few studies have examined how tri‐trophic interactions involving vectors affect the spread of pathogens. Here we assessed effects of food web structure on aphid vectors and the prevalence of an aphid‐borne persistent pathogen (Pea enation mosaic virus, PEMV) in pea plants. We experimentally manipulated ladybird predators, alternative host plants, and non‐vector herbivores and assessed responses of pea aphids and PEMV using structural equation models. We show that variation in bottom‐up, top‐down, and horizontal interactions mediated PEMV prevalence. Predators reduced PEMV prevalence by consuming aphids, but an alternative host plant (vetch) had the opposite effect by promoting aphid movement and abundance. Non‐vector herbivores (pea leaf weevil) increased PEMV susceptibility in peas. In turn, weevils offset the positive effects of predators on PEMV, but increased the negative effects of vetch. Our results show that tri‐trophic interactions within insect and plant food webs can mediate vector biology with synergistic and opposing effects on pathogens. Continuing to assess how community‐wide interactions affect vectors will aid in our understanding of vector‐borne pathosystems.
Chalcogenide Materials and Derivatives for Photovoltaic Applications
Authors: Buffiere Marie , Dhawale Dattatray S. , El-Mellouhi Fedwa
Published: September 2019

Chalcogenide AB(S,Se)3 materials have recently attracted increased attention as they could simultaneously solve both the stability and toxicity issues faced by conventional perovskite solar cells. Computer‐aided design of metal chalcogenide semiconductors has experienced important progress over the past few years, leading to the discovery of very promising AB(S,Se)3 compounds and derivatives for application as absorbers in thin‐film photovoltaic devices. Experimental evidence demonstrates that the synthesis of such compounds is possible, confirming the theoretical predictions, although more research work needs to be done to further investigate the optoelectrical properties of the corresponding thin films. With the aim to provide an exhaustive starting point to further develop chalcogenide absorbers and related devices, this Review presents both an overview of the predicted chalcogenide materials and interesting derivatives for thin‐film solar cells applications, as well as a summary of the synthesis techniques developed so far to prepare such materials. The possible challenges that can be encountered during the development of chalcogenide‐based solar cells are also discussed.
Petrogenesis and tectonic implications of the early Carboniferous volcanic rocks in West Junggar, NW China
Authors: Weng Kai , Ma Zhongping , Cao Kai , Dong Yunpeng , Chen Bo , Zhao Xiaojian
Published: September 2019

Carboniferous magmatism in the Darbut region is critical for understanding the evolutionary history of the accretionary orogenesis of the West Junggar area in the Central Asian Orogenic Belt. In this paper, zircon U–Pb geochronological, whole‐rock geochemical and Sr–Nd–Pb–Hf isotopic analyses of the basalts, basaltic andesite, and dacite from the Carboniferous Tailegula Formation, Darbut region, have been performed. The magmatic zircons from basalt, basaltic andesite, and dacite yield concordia U–Pb isotope ages of 344 ± 4, 347 ± 3, and 340 ± 5 Ma, respectively, which are interpreted as the crystallization ages of these rocks. The basalts and basaltic andesite are characterized by an alkali composition; high Nb/Yb, Th/Yb, Ta/Yb, La/Sm, and Sm/Yb trace element ratios and Pb isotopic ratios; moderate (87Sr/86Sr)i ratios; low (143Nb/144Nb)i ratios; and positive εNd(t) (+0.66 − +4.73) and εHf(t) (+1.7 − +15.2) values. These characteristics indicate that the magmas were derived from mixed mantle sources, that is, enriched mantle sources and high U/Pb ratio mantle (HIMU) component sources with ≤10% partial melting of garnet and spinel lherzolite. The samples display pronounced light rare earth elements (LREEs) and incompatible element enrichment patterns with positive Nb–Ta anomalies and a high Pb content and Nb/La ratios but low (Th/Nb)N ratios and a lower degree of partial melting, implying that these rocks were formed in a continental extensional setting. Based on our results and that of previous studies, we conclude that the early Carboniferous volcanic rocks in the Darbut region formed by mantle plume or regional‐scale mantle upwelling in a continental extensional setting after closure of the Junggar Ocean.
Metamorphic evolution and tectonic significance of ultrahigh‐temperature mafic granulites in the southern part of the Shiguai area, Daqingshan, China
Authors: Yang Yan , Liang Chenyue , Zheng Changqing , Zhang Jinrui , Xu Xuechun , Guo Tengda , Zhou Xiao , Hu Pengyue , Han Xiaomeng , Hao Yujie
Published: September 2019

Ultrahigh‐temperature (UHT) mafic granulites in the southern part of the Shiguai area in Daqingshan, China, crop out within the Shanheyuan Gneiss of the Khondalite Belt (KB), a Paleoproterozoic tectonic belt in the Western Block of the North China Craton (NCC). The UHT mafic granulites occur within hypersthene‐bearing dioritic–granitic gneiss as irregular lenses and deformed dike swarms. Four metamorphic generation assemblages (M1–M4) are recognized in the studied samples. M1 is defined by the enclosed orthopyroxene and clinopyroxene within the “red eye” corona of the garnet, representing the prograde metamorphic stage. M2 (UHT granulite‐facies) is marked by the appearance of “red eye” corona of the garnet, with mineral assemblages of grt–cpx–opx–pl–ilm–q. M3 is defined by spinel‐rich symplectites between garnet and orthopyroxene, including grt–opx–pl–spl–mt–ilm. M4 (amphibolite facies) is featured by the development of amphibole. Phase equilibrium modelling and some critical thermobarometers are combined to constrain the P–T evolution of the studied samples. The P–T conditions for the M1–M4 are respectively estimated at ~8 kbar/~771–852°C, ~9.4–10.0 kbar/~930–965°C, ~5.0–5.4 kbar/~865–910°C, ~5.0–5.2 kbar/~675–682°C, which define a clockwise P–T path, involving near‐isothermal decompression following the peak metamorphism. The P–T path indicates that the rocks underwent a sequence of tectonothermal processes that started with crustal thickening (M1–M2), followed by rapid crustal uplift (M3) and cooling (M4). This process is inferred that the metamorphism of the UHT mafic granulites was associated with rapid exhumation and uplift that followed the continent–continent collision and amalgamation of the Yinshan and Ordos blocks. This amalgamation formed the Paleoproterozoic KB in the Western Block of the NCC.