bluuebunny/crossref_metadata_2025_split huggingface dataset:
Limnological Comparisons of Threats to Aquatic Life Owing to Thermal Stratification in two Morphometrically Different Urban Shallow Lakes
Authors: Samal Nihar R. , Roy Pankaj K. , Roy Malabika B. , Mazumdar Asis Mazumdar 
Published: November 2017

A minimum value in the Dissolved Oxygen distribution of two shallow lakes namely, Rabindra Sarobar in south Kolkata and Subhas Sarobar in East Kolkata in the Gangetic Delta plain, has been observed to develop in the Hypolimnion during the stratified period. This minimum is usually explained by the accumulation of organic matter from the overlying layer of water. The introduction of organic matter from allochthonous and autochthonous sources is also a likely contributor to the accelerated oxygen depletion within Hypolimnion. The thermal stratification, in general, which occurs in these tropical lakes, is of direct relevance in maintaining the water quality standards, particularly for higher aquatic life. The present article attempts to investigate the possible depletion of hypolimnetic oxygen depletion as a result of the impact of thermal stratification. These investigations will be the basic guidelines for the fishermen and their livelihoods potentially depend upon the different varieties of fishing on daily basis. The massive summer fish kills in these lakes is a major devastating happenings that is reported by the fishermen and also it is well evident from our experimental observations. The comparison of the biodiversity of these two lakes is attempted in the present investigation. Key Words: Thermal stratification, Dissolved Oxygen, Tropical Shallow Lake, Hypolimnion, biodiversity
Polyketones: Synthesis and Applications
Authors: Vavasori Andrea , Ronchin Lucio 
Published: November 2017

AbstractPolyketones, also known as aliphatic polyketone, are a relatively new class of polymers obtained by the perfectly alternating copolymerization or terpolymerization of α‐olefins with carbon monoxide. The polymerization is well catalyzed by Pd(II) complexes; the activity of which strongly depends by the nature of the ligand, promoting agents, and solvent used. Owing to their excellent mechanical properties, thermoplastic polyketones have found diverse industrial applications ranging from fibers, fire‐retardant materials, and film coatings to membranes, packaging materials, and adhesives. Herein, we review the synthesis, properties, and applications of polyketones. In addition, industrial production of polyketone is also discussed.
Intermediate‐Scale Experimental Study to Improve Fundamental Understanding of Attenuation Capacity for Leaking CO2 in Heterogeneous Shallow Aquifers
Authors: Plampin Michelle R. , Porter Mark L. , Pawar Rajesh J. , Illangasekare Tissa H. 
Published: November 2017

AbstractTo assess the risks of Geologic Carbon Sequestration (GCS), it is crucial to understand the fundamental physicochemical processes that may occur if and when stored CO2 leaks upward from a deep storage reservoir into the shallow subsurface. Intermediate‐scale experiments allow for improved understanding of the multiphase evolution processes that control CO2 migration behavior in the subsurface, because the boundary conditions, initial conditions, and porous media parameters can be better controlled and monitored in the laboratory than in field settings. For this study, a large experimental test bed was designed to mimic a cross section of a shallow aquifer with layered geologic heterogeneity. As water with aqueous CO2 was injected into the system to mimic a CO2‐charged water leakage scenario, the spatiotemporal evolution of the multiphase CO2 plume was monitored. Similar experiments were performed with two different sand combinations to assess the relative effects of different types of geologic facies transitions on the CO2 evolution processes. Significant CO2 attenuation was observed in both scenarios, but by fundamentally different mechanisms. When the porous media layers had very different permeabilities, attenuation was caused by local accumulation (structural trapping) and slow redissolution of gas phase CO2. When the permeability difference between the layers was relatively small, on the other hand, gas phase continually evolved over widespread areas near the leading edge of the aqueous plume, which also attenuated CO2 migration. This improved process understanding will aid in the development of models that could be used for effective risk assessment and monitoring programs for GCS projects.
Cartograms Facilitate Communication of Climate Change Risks and Responsibilities
Authors: Döll Petra 
Published: November 2017

AbstractCommunication of climate change (CC) risks is challenging, in particular if global‐scale spatially resolved quantitative information is to be conveyed. Typically, visualization of CC risks, which arise from the combination of hazard, exposure and vulnerability, is confined to showing only the hazards in the form of global thematic maps. This paper explores the potential of contiguous value‐by‐area cartograms, that is, distorted density‐equalizing maps, for improving communication of CC risks and the countries' differentiated responsibilities for CC. Two global‐scale cartogram sets visualize, as an example, groundwater‐related CC risks in 0.5° grid cells, another one the correlation of (cumulative) fossil‐fuel carbon dioxide emissions with the countries' population and gross domestic product. Viewers of the latter set visually recognize the lack of global equity and that the countries' wealth has been built on harmful emissions. I recommend that CC risks are communicated by bivariate gridded cartograms showing the hazard in color and population, or a combination of population and a vulnerability indicator, by distortion of grid cells. Gridded cartograms are also appropriate for visualizing the availability of natural resources to humans. For communicating complex information, sets of cartograms should be carefully designed instead of presenting single cartograms. Inclusion of a conventionally distorted map enhances the viewers' capability to take up the information represented by distortion. Empirical studies about the capability of global cartograms to convey complex information and to trigger moral emotions should be conducted, with a special focus on risk communication.
Observations Directly Linking Relativistic Electron Microbursts to Whistler Mode Chorus: Van Allen Probes and FIREBIRD II
Authors: Breneman A. W. , Crew A. , Sample J. , Klumpar D. , Johnson A. , Agapitov O. , Shumko M. , Turner D. L. , Santolik O. , Wygant J. R. , Cattell C. A. , Thaller S. , Blake B. , Spence H. , Kletzing C. A. 
Published: November 2017

AbstractWe present observations that provide the strongest evidence yet that discrete whistler mode chorus packets cause relativistic electron microbursts. On 20 January 2016 near 1944 UT the low Earth orbiting CubeSat Focused Investigations of Relativistic Electron Bursts: Intensity, Range, and Dynamics (FIREBIRD II) observed energetic microbursts (near L = 5.6 and MLT = 10.5) from its lower limit of 220 keV, to 1 MeV. In the outer radiation belt and magnetically conjugate, Van Allen Probe A observed rising‐tone, lower band chorus waves with durations and cadences similar to the microbursts. No other waves were observed. This is the first time that chorus and microbursts have been simultaneously observed with a separation smaller than a chorus packet. A majority of the microbursts do not have the energy dispersion expected for trapped electrons bouncing between mirror points. This confirms that the electrons are rapidly (nonlinearly) scattered into the loss cone by a coherent interaction with the large amplitude (up to ∼900 pT) chorus. Comparison of observed time‐averaged microburst flux and estimated total electron drift shell content at L = 5.6 indicate that microbursts may represent a significant source of energetic electron loss in the outer radiation belt.
Effect of Seismogenic Depth and Background Stress on Physical Limits of Earthquake Rupture Across Fault Step Overs
Authors: Bai Kangchen , Ampuero Jean‐Paul 
Published: November 2017

AbstractEarthquakes can rupture geometrically complex fault systems by breaching fault step overs. Quantifying the likelihood of rupture jump across step overs is important to evaluate earthquake hazard and to understand the interactions between dynamic rupture and fault growth processes. Here we investigate the role of seismogenic depth and background stress on physical limits of earthquake rupture across fault step overs. Our computational and theoretical study is focused on the canonical case of two parallel strike‐slip faults with large aspect ratio, uniform prestress and friction properties. We conduct a systematic set of 3‐D dynamic rupture simulations with different seismogenic depth, step over distance, and initial stresses. We find that the maximum step over distanceHcthat a rupture can jump depends on seismogenic depthWand strength excess to stress drop ratioS, commonly used to evaluate probable rupture velocity, as, wheren= 2 whenHc/W< 0.2 (orS> 1.5) andn= 1 otherwise. The critical nucleation size, largely controlled by frictional properties, has a second‐order effect onHc. Rupture on the secondary fault is mainly triggered by the stopping phase emanated from the rupture end on the primary fault. Asymptotic analysis of the peak amplitude of stopping phases sheds light on the mechanical origin of the relations betweenHc,W, andS, and leads to the scaling regime withn= 1 in far field andn= 2 in near field. The results suggest that strike‐slip earthquakes on faults with large seismogenic depth or operating at high shear stresses can jump wider step overs than observed so far in continental interplate earthquakes.
Space‐Time Patterns of Meteorological Drought Events in the European Greater Alpine Region Over the Past 210 Years
Authors: Haslinger K. , Blöschl G. 
Published: November 2017

AbstractDroughts may have tremendous impacts on humans. However, the space‐time characteristics of droughts are not very well understood, as case studies usually focus on individual drought events. Here we investigate the spatiotemporal drought characteristics of a large sample of events over the past 210 years in the Greater Alpine Region of Central Europe. We use monthly precipitation data, and flag, for each grid point, time steps with precipitation below a 20% percentile. We then propose a new method that detects drought events by connecting the flagged elements to space‐time drought regions. In contrast to the traditional drought indices that are based on a fixed, prescribed time window, this method is able to identify droughts of different durations in an objective way. The data show multidecadal variations of drought frequency, duration, intensity, and severity, but no consistent trends over the 210 year period. The top 5% of events in terms of their severity show a shift in seasonality from winter/spring events in the late nineteenth century toward autumn events during the last decades of the twentieth century. The most severe events center either in the Northwest or in the Southeast of the region analyzed. We found no significant correlations of drought frequency, duration, intensity, and severity with the temperature increases in the past three decades. Dry springs significantly enhance temperatures during summer droughts, suggesting a soil moisture‐temperature feedback.
pH/Ultrasound Dual‐Responsive Gas Generator for Ultrasound Imaging‐Guided Therapeutic Inertial Cavitation and Sonodynamic Therapy
Authors: Feng Qianhua , Zhang Wanxia , Yang Xuemei , Li Yuzhen , Hao Yongwei , Zhang Hongling , Hou Lin , Zhang Zhenzhong 
Published: November 2017

AbstractHerein, a pH/ultrasound dual‐responsive gas generator is reported, which is based on mesoporous calcium carbonate (MCC) nanoparticles by loading sonosensitizer (hematoporphyrin monomethyl ether (HMME)) and modifying surface hyaluronic acid (HA). After pinpointing tumor regions with prominent targeting efficiency, HMME/MCC‐HA decomposes instantaneously under the cotriggering of tumoral inherent acidic condition and ultrasound (US) irradiation, concurrently accompanying with CO2 generation and HMME release with spatial/temporal resolution. Afterward, the CO2 bubbling and bursting effect under US stimulus results in cavitation‐mediated irreversible cell necrosis, as well as the blood vessel destruction to further occlude the blood supply, providing a “bystander effect.” Meanwhile, reactive oxygen species generated from HMME can target the apoptotic pathways for effective sonodynamic therapy. Thus, the combination of apoptosis/necrosis with multimechanisms consequently results in a remarkable antitumor therapeutic efficacy, simultaneously minimizing the side effects on major organs. Moreover, the echogenic property of CO2 make the nanoplatform as a powerful ultrasound contrast agent to identify cancerous lesions. Based on the above findings, such all‐in‐one drug delivery platform of HMME/MCC‐HA is utilized to provide the US imaging guidance for therapeutic inertial cavitation and sonodynamic therapy simultaneously, which highlights possibilities of advancing cancer theranostics in biomedical fields.
Flexible and Adaptable Light‐Emitting Coatings for Arbitrary Metal Surfaces based on Optical Tamm Mode Coupling
Authors: Jiménez‐Solano Alberto , Galisteo‐López Juan F. , Míguez Hernán 
Published: November 2017

AbstractThis study demonstrates a design that maximizes the power radiated into free space from a monolayer of nanoemitters embedded in a flexible distributed Bragg reflector conformably attached to a metal surface. This is achieved by positioning the light source at the precise depth within the multilayer for which optical Tamm states provide enhanced quantum yield and outcoupling efficiency, which are combined to optimize the luminous power radiated by the surface of the ensemble. This approach, based on the adhesion of flexible multilayer stacks onto metal surfaces with an arbitrary curvature, is versatile and permits the realization of spectrally narrow monodirectional or self‐focusing light‐emitting surfaces.
Cyclopropanation of Benzene Rings by Oxidatively Generated α‐Oxo Gold Carbene: One‐Pot Access to Tetrahydropyranone‐Fused Cycloheptatrienes from Propargyl Benzyl Ethers
Authors: Ji Kegong , Zhang Liming 
Published: November 2017

AbstractCyclopropanations of benzene rings by oxidatively generated α‐oxo gold carbenes are for the first time demonstrated in a Buchner reaction, in which readily available propargyl benzyl ethers are converted in one‐pot to tetrahydropyranone‐fused cycloheptatrienes via sequential oxidative gold catalysis and base‐promoted isomerization. Additional examples of arene cyclopropanations without fragmentation of the cyclopropane ring are also realized.magnified image
Fabrication of Solvent‐Resistant Copolyimide Membranes for Pervaporation Recovery of Amide Solvents
Authors: Xu Rong , Guo Meng , Wang Jin , Zhang Qi , Zhong Jing 
Published: November 2017

AbstractDimethylformamide and dimethylacetamide are important industrial chemicals, which are used, e.g., as solvents in the manufacturing of polyurethane products. They are conventionally recovered by distillation associated with high energy consumption and operating costs. In contrast, pervaporation is an energy‐efficient membrane separation method. Ceramic‐supported copolyimide membranes were synthesized via the two‐step thermal imidization method and applied to pervaporation recovery of dimethylformamide and dimethylacetamide. The prepared membrane demonstrated high resistance to the two amides in a wide concentration range. Effects of operating parameters such as feed temperature and feed concentration on pervaporation performances were investigated. The results showed that the copolyimide membrane is a promising candidate for the recovery of high concentrations of amide solvents.
Axial Backmixing and Residence Time Distribution in a Miniaturized, Stirred‐Pulsed Extraction Column
Authors: Soboll Sebastian , Bittorf Lukas , Kockmann Norbert 
Published: November 2017

AbstractAxial backmixing is an important issue in extraction columns since it heavily affects the mass transfer performance. A miniaturized, stirred‐pulsed column was investigated regarding its backmixing characteristics in the continuous phase, using the system water/n‐butyl acetate. Residence time distributions were determined through pulse experiments with potassium chloride, which was detected via electrical conductivity. To perform the conductivity measurement without distortion of the two‐phase flow, electrodes with an annular design that precisely line up with the inner column wall were manufactured. This design is a promising alternative for use in small‐scale tubular devices where commercial electrodes do not fit and in applications where interference with the flow must be avoided.
Mesenchymal Stem Cell Preparation and Transfection‐free Ferumoxytol Labeling for MRI Cell Tracking
Authors: Liu Li , Ho Chien 
Published: November 2017

AbstractMesenchymal stem cells (MSCs) are multipotent cells and are the most widely studied cell type for stem cell therapies. In vivo cell tracking of MSCs labeled with an FDA‐approved superparamagnetic iron‐oxide (SPIO) particle by magnetic resonance imaging (MRI) provides essential information, e.g., MSC engraftment, survival, and fate, thus improving cell therapy accuracy. However, current methodology for labeling MSCs with Ferumoxytol (Feraheme®), the only FDA‐approved SPIO particle, needs transfection agents. This unit describes a new “bio‐mimicry” protocol to prepare more native MSCs by using more “in vivo environment” of MSCs, so that the phagocytic activity of cultured MSCs is restored and expanded MSCs can be labeled with Ferumoxytol, without the need for transfection agents and/or electroporation. Moreover, MSCs re‐size to a more native size, reducing from 32.0 to 19.5 μm. The MSCs prepared from this protocol retain more native properties and would be useful for biomedical applications and MSC‐tracking studies by MRI. © 2017 by John Wiley & Sons, Inc.
Human Adipose‐Derived Stromal Cell Isolation Methods and Use in Osteogenic and Adipogenic In Vivo Applications
Authors: Brett Elizabeth , Tevlin Ruth , McArdle Adrian , Seo Eun Young , Chan Charles K.F. , Wan Derrick C. , Longaker Michael T. 
Published: November 2017

AbstractAdipose tissue represents an abundant and easily accessible source of multipotent cells, which may serve as excellent building blocks for tissue engineering. This article presents a newly described protocol for isolating adipose‐derived stromal cells (ASCs) from human lipoaspirate, compared to the standard protocol for harvesting ASCs established in 2001.Human ASC isolation is performed using two methods, and resultant cells are compared through cell yield, cell viability, cell proliferation and regenerative potential. The osteogenic and adipogenic potential of ASCs isolated using both protocols are assessed in vitro and gene expression analysis is performed. The focus of this series of protocols is the regenerative potential of both cell populations in vivo. As such, the two in vivo animal models described are fat graft retention (soft tissue reconstruction) and calvarial defect healing (bone regeneration). The techniques described comprise fat grafting with cell assisted lipotransfer, and calvarial defect creation healed with cell‐seeded scaffolds. © 2017 by John Wiley & Sons, Inc.
Potential contributions of root decomposition to the nitrogen cycle in arctic forest and tundra
Authors: Träger Sabrina , Milbau Ann , Wilson Scott D. 
Published: November 2017

AbstractPlant contributions to the nitrogen (N) cycle from decomposition are likely to be altered by vegetation shifts associated with climate change. Roots account for the majority of soil organic matter input from vegetation, but little is known about differences between vegetation types in their root contributions to nutrient cycling. Here, we examine the potential contribution of fine roots to the N cycle in forest and tundra to gain insight into belowground consequences of the widely observed increase in woody vegetation that accompanies climate change in the Arctic. We combined measurements of root production from minirhizotron images with tissue analysis of roots from differing root diameter and color classes to obtain potential N input following decomposition. In addition, we tested for changes in N concentration of roots during early stages of decomposition, and investigated whether vegetation type (forest or tundra) affected changes in tissue N concentration during decomposition. For completeness, we also present respective measurements of leaves. The potential N input from roots was twofold greater in forest than in tundra, mainly due to greater root production in forest. Potential N input varied with root diameter and color, but this variation tended to be similar in forest and tundra. As for roots, the potential N input from leaves was significantly greater in forest than in tundra. Vegetation type had no effect on changes in root or leaf N concentration after 1 year of decomposition. Our results suggest that shifts in vegetation that accompany climate change in the Arctic will likely increase plant‐associated potential N input both belowground and aboveground. In contrast, shifts in vegetation might not alter changes in tissue N concentration during early stages of decomposition. Overall, differences between forest and tundra in potential contribution of decomposing roots to the N cycle reinforce differences between habitats that occur for leaves.
How do emerging multinationals configure political connections across institutional contexts?
Authors: Chen Liang , Li Yi , Fan Di 
Published: November 2017

Research SummaryForming informal ties with political agents is viewed as a viable strategy for multinational enterprises seeking to enter emerging countries. Less is known about the conditions under which political connection is most helpful for firms dealing with cross‐border institutional distance. We discuss the distinctive mechanisms through which emerging multinationals may benefit from both home and host political connections. Based on the strategy tripod perspective, we postulate that the importance of different types of connections depends on the overall configurations of a firm’s resources and industry characteristics, and these may change with institutional distance. Our analysis of a sample of Chinese high‐tech manufacturing firms yields new insights into political connections, institutional distance, and the strategy tripod perspective.Managerial SummaryPolitical connections play an important role in firms’ international expansion. In this study, we consider the importance of home political connections and host political connections in overcoming institutional barriers to foreign entry. We show that this importance varies, depending on firms’ resource bases and industry dynamics, and it may switch from a useful asset to a dispensable one under certain circumstances. We reach our conclusion from an analysis of Chinese high‐tech manufacturing firms’ foreign direct investment.