bluuebunny/crossref_metadata_2025_split huggingface dataset:
A global model of tropospheric chlorine chemistry: Organic versus inorganic sources and impact on methane oxidation
Authors: Hossaini Ryan , Chipperfield Martyn P. , Saiz‐Lopez Alfonso , Fernandez Rafael , Monks Sarah , Feng Wuhu , Brauer Peter , von Glasow Roland 
Published: November 2016

AbstractChlorine atoms (Cl) are highly reactive toward hydrocarbons in the Earth's troposphere, including the greenhouse gas methane (CH4). However, the regional and global CH4 sink from Cl is poorly quantified as tropospheric Cl concentrations ([Cl]) are uncertain by ~2 orders of magnitude. Here we describe the addition of a detailed tropospheric chlorine scheme to the TOMCAT chemical transport model. The model includes several sources of tropospheric inorganic chlorine (Cly), including (i) the oxidation of chlorocarbons of natural (CH3Cl, CHBr2Cl, CH2BrCl, and CHBrCl2) and anthropogenic (CH2Cl2, CHCl3, C2Cl4, C2HCl3, and CH2ClCH2Cl) origin and (ii) sea‐salt aerosol dechlorination. Simulations were performed to quantify tropospheric [Cl], with a focus on the marine boundary layer, and quantify the global significance of Cl atom CH4 oxidation. In agreement with observations, simulated surface levels of hydrogen chloride (HCl), the most abundant Cly reservoir, reach several parts per billion (ppb) over polluted coastal/continental regions, with sub‐ppb levels typical in more remote regions. Modeled annual mean surface [Cl] exhibits large spatial variability with the largest levels, typically in the range of 1–5 × 104 atoms cm−3, in the polluted northern hemisphere. Chlorocarbon oxidation provides a tropospheric Cly source of up to ~4320 Gg Cl/yr, sustaining a background surface [Cl] of <0.1 to 0.5 × 103 atoms cm−3 over large areas. Globally, we estimate a tropospheric methane sink of ~12–13 Tg CH4/yr due the CH4 + Cl reaction (~2.5% of total CH4 oxidation). Larger regional effects are predicted, with Cl accounting for ~10 to >20% of total boundary layer CH4 oxidation in some locations.
The uptake of HO2 on meteoric smoke analogues
Authors: James Alexander D. , Moon Daniel R. , Feng Wuhu , Lakey Pascale S. J. , Frankland Victoria L. , Heard Dwayne E. , Plane John M. C. 
Published: November 2016

AbstractThe kinetics of heterogeneous HO2 uptake onto meteoric smoke particles (MSPs) has been studied in the laboratory using analogues of MSP aerosol entrained into a flow tube. The uptake coefficient, γ, was determined on synthetic amorphous olivine (MgFeSiO4) to be (6.9 ± 1.2) × 10−2 at a relative humidity (RH) of 10%. On forsterite (Mg2SiO4), γ = (4.3 ± 0.4) × 10−3 at RH = 11.6% and (7.3 ± 0.4) × 10−2 at RH = 9.9% on fayalite (Fe2SiO4). These results indicate that Fe plays a more important mechanistic role than Mg in the removal of HO2 from the gas phase. Electronic structure calculations show that Fe atoms exposed at the particle surface provide a catalytic site where HO2 is converted to H2O2 via an Eley‐Rideal mechanism, but this does not occur on exposed surface Mg atoms. The impact of this heterogeneous process in the middle atmosphere was then investigated using a whole atmosphere chemistry‐climate model which incorporates a microphysical treatment of MSPs. Using a global MSP production rate from meteoric ablation of 44 t/day, heterogeneous uptake (with γ = 0.2) on MSPs significantly alters the HOx budget in the nighttime polar vortex. This impact is highly latitude dependent and thus could not be confirmed using currently available satellite measurements of HO2, which are largely unavailable at latitudes greater than 70°.
Estimation of three‐phase relative permeability by simulating fluid dynamics directly on rock‐microstructure images
Authors: Jiang F. , Tsuji T. 
Published: November 2016

AbstractGiven the world's growing demand for energy, a combination of geological CO2 sequestration and enhanced oil recovery (EOR) technologies is currently regarded as a promising solution, as it would provide a means of reducing carbon emissions into the atmosphere while also leading to the economic benefit of simultaneously recovering oil. The optimization of injection strategies to maximize CO2 storage and increase the oil recovery factors requires complicated pore‐scale flow information within a reservoir system consisting of coexisting oil, water, and CO2 phases. In this study, an immiscible three‐phase lattice‐Boltzmann (LB) model was developed to investigate the complicated flow state with interaction between water, oil, and CO2 systems in porous media. The two main mechanisms of oil remobilization, namely, double‐drainage and film flow, can be captured by our model. The estimation of three‐phase relative permeability is proposed using the digital rock physics (DRP) simulations. The results indicate that the relative permeability of CO2 as calculated using our steady state method is not sensitive to the initial oil fraction if the oil distribution is originally uniform. Baker's (1988) empirical model was tested and found to be able to provide a good prediction of the three‐phase relative permeability data. Our numerical method provides a new tool for accurately predicting three‐phase relative permeability data directly based on micro‐CT rock images.
Plant Responses to Freezing
Authors: Fujikawa Seizo 
Published: November 2016

Abstract

During the course of evolution, plants have developed complex mechanisms to survive under a freezing condition. The ability of temperate plants to endure freezing differs depending on the season and depending on the region they inhabit in relation to the environmental temperatures. The prerequisite for survival of plants under a freezing condition is avoidance of lethal intracellular freezing in living cells. Depending on the function in living cells, such avoidance mechanisms change due to the difference in responses of cell walls as well as the plasma membrane to extracellular ice. Owing to these differences, living plant cells adapt to freezing by extracellular freezing and deep supercooling and also by extraorgan freezing, in which cells adapt by an intermediate form between extracellular freezing and deep supercooling.

Key Concepts

The first step of freezing resistance is the blocking of cell walls and plasma membranes against inoculation of extracellular ice.

Living cells in most temperate plant tissues respond to freezing by extracellular freezing, in which cell walls inhibit ice penetration but allow dehydration.

Interbilayer events, which are caused by the close approach of membranes by mechanical stress of freezing, are the main cause of injury by extracellular freezing.

Many cold acclimation‐induced changes are related to inhibition of or reduction in the incidence of interbilayer events.

Adaptation by deep supercooling occurs in cells with rigid and thick walls, which do not allow penetration of ice or dehydration.

Supercooling capacity is changed by intracellular contents, especially by the interaction of antiice nucleation polyphenols with ice nucleators.

Dormant buds of many woody plants respond to freezing by extraorgan freezing, in which formation of extracellular ice is excluded in tissues with freezing‐susceptible cells.
Communications, Radar, and Wireless Sensor Networks, Detection in
Authors: Varshney Pramod K. , Viswanathan Ramanarayanan 
Published: November 2016

AbstractDetection of signals in noise arises in a number of engineering applications. Here, we restrict our attention to three applications within electrical engineering, namely, communications, radar signal processing, and wireless sensor networks. We first formulate signal detection problems in a general framework and then discuss them in the context of the three applications. Because of space limitations, the topics have been selected to provide a broader exposure to this field. Many references have been provided for additional insights.
Operations Research, Simulation
Authors: Sharkey Phoebe D. 
Published: November 2016

AbstractSimulation models have been indispensable tools for decision makers in many different public and private environments. Simulation models are created in order to provide valuable insight to decision makers by replicating real‐life decision scenarios and exploring more complete information about the relative uncertainties and their impacts in those environments. This article discusses the methodology of developing a simulation model that involves the abstraction of a real‐life system into a symbolic model format. The multiple stages required in a Monte Carlo simulation study include the (i) problem statement definition; (ii) information gathering and data preparation; (iii) model conceptualization; (iv) model implementation; (v) analysis and interpretation; (vi) verification and validation; and (vii) implementation and documentation. Once a model has been verified and validated as accurately representing the real‐world environment, many “What if” questions about the system can be posed. Illustrative examples are presented.
Dynamic Allocation Index
Authors: Gittins John C. 
Published: November 2016

AbstractGiven a constant stream of some resource and a set of projects each of which generates a stochastic reward stream when the resource stream is allocated to it, the question arises of how to adaptively allocate the resource stream between the projects so as to maximize the overall payoff. The dynamic allocation (or Gittins) index for a project is a function defined on the state space of the project for which under exponential discounting the overall payoff is maximized by a policy of allocating the resource stream at each decision time to the project for which the index value is currently the largest. This article discusses the uses and calculation of these indices and the optimality of index‐based policies.
Spatial Analysis in Ecology
Authors: Fortin Marie‐Josée , Dale Mark R.T. , Ver Hoef Jay M. 
Published: November 2016

Abstract

The first step in understanding ecological processes is to identify their spatial patterns. Ecological data are usually characterized by spatial structures and as such, they are said to be spatially autocorrelated.
Spatial autocorrelation
refers to the pattern where the values of a quantitative variable are more similar at nearby locations than expected by chance alone. Most ecological data exhibit some degree of spatial autocorrelation that is modulated by the spatial sampling design used to record the data and the method used to analyze them. Furthermore, ecological data can be the end result of several processes operating at different spatial scales. In such cases, ecological data are a composite of large‐scale trends at the macroscale, gradients and patchiness at mesoscale, and random patterns at local and microscales. Hence, to estimate the magnitude and the extent of spatial autocorrelation, various spatial statistics can be used. Here, we review the spatial statistics most commonly used by ecologists.
Mixed‐Mode Surveys
Authors: Klausch Thomas , Schouten Barry 
Published: November 2016

Abstract
Surveys can be conducted with a variety of survey modes. Over the past decade, and following the emergence of the Web, many surveys have moved to designs in which multiple modes are combined, the so‐called mixed‐mode surveys. The contemporary modes are telephone, face‐to‐face, mail/paper, and online through various devices (desktop/laptop, tablet, and smartphone). Survey modes affect all errors known to reduce the accuracy of survey statistics. An extensive literature has been developed around mode comparisons and multimode survey design and estimation. In the article, the impact of the choice of modes on survey error is discussed and methodology is presented to reduce method effects that result from the choice of modes.
Informative Cluster Size
Authors: Williamson John M. 
Published: November 2016

Abstract
Correlated outcomes are collected in many areas of research and occur for a variety of reasons. Valid inference is reliant upon properly accounting for the correlation among outcomes within subjects. Analysis should also consider informative cluster size, which occurs when cluster size is related to the outcome of interest and is common in studies with periodontal, surgical outcome, and reproductive toxicology data, among others. Such methods of analysis are increasingly available.
Project Management in the Oil & Gas Industry – ABayesian Approach
Authors: Caron Franco , Ruggeri Fabrizio 
Published: November 2016

AbstractA reliable “estimate at completion” from the early stage of project execution is essential in order to enable efficient and proactive project management. Thenonrepetitiveanduncertainnature of projects and the involvement ofmultiple stakeholdersrequire the use and integration of multiple informative sources in order to provide accurate forecasts. Moreover, in the Oil & Gas industry, projects are characterized by a high level of complexity and financial impact.The article aims at multiple objectives such as introducing the need for the identification and utilization of all the available knowledge in order to improve the forecasting process; developing a Bayesian approach in order to integrate the diverse knowledge sources; exploring the integration of data records and experts' judgment related to the ongoing project; exploring the integration of data records related to projects completed in the past and to the ongoing project; and finally developing a Bayesian model capable of using three different knowledge sources, data records and experts' judgments related to the ongoing project and data records related to similar projects completed in the past.The model has been tested in a set of large and complex projects in the Oil & Gas industry, in order to forecast the final duration and the final cost. The results show a higher forecasting accuracy of the Bayesian model compared to the traditional earned value management (EVM) methodology.
Optimal Dynamic Treatment Regimes
Authors: Davidian Marie , Tsiatis Anastasios A. , Laber Eric B. 
Published: November 2016

Abstract
A dynamic treatment regime is a set of sequential decision rules, each corresponding to a key decision point in a disease or disorder process that dictates the next treatment for a patient based on accrued information on the patient. An optimal dynamic treatment regime is a regime that leads to the most favorable outcome on average if used to select treatment for the entire patient population. This entry reviews a statistical framework in which an optimal dynamic treatment regime can be defined precisely and methods by which it can be estimated from data under appropriate assumptions.
Noninferiority Margin and Other Methodological Issues in Designing Noninferiority Trials: A Review
Authors: Gupta Sandeep Kumar 
Published: November 2016

AbstractNoninferiority clinical trials help in detecting a new treatment that have roughly the same effectiveness, yet may offer different advantages. Thus, noninferiority trials can be used in a situation when a new treatment has almost the same effectiveness as its comparator but may offer other advantages over the existing drug such as a novel method of administration or a better safety profile. Some argue that noninferiority trials only benefit pharmaceutical companies as they permit medicines without any added effectiveness to get marketing authorization. There are many basic differences between noninferiority and superiority trials. Noninferiority clinical trials aim to prove that the test product is not unreasonably inferior, or “noninferior” than the comparator by more than a prestipulated margin. From a methodological perspective, compared to superiority trials, noninferiority trials have methodological issues in design and analysis that can influence proper inference and also noninferiority trials are a source of great dispute. One of the pivotal but arduous steps in planning noninferiority trial is itemizing a noninferiority margin: a prelude below which it can be accepted that the experimental drug is not worse than its comparator.
Degenerative Ataxias: challenges in clinical research
Authors: Subramony Sub H. 
Published: November 2016

AbstractThe degenerative ataxias are a very heterogeneous group of disorders that include numerous genetic diseases as well as apparently “sporadic” entities. There has been an explosion of discoveries related to genetic defects and related pathomechanisms that has brought us to the threshold of meaningful therapies in some but not all of these diseases. There also continues to be lack of knowledge of the causation of disease in a sizeable proportion of these patients. The overall rarity of ataxias as a whole and certainly of the individual genetic entities together with slow and variable progression and variable prognosis in juxtaposition with a rapid development of possible therapies in the horizon such as gene replacement and gene knock‐down strategies places the ataxias in a unique position distinct from other similar neurodegenerative diseases. The pace of laboratory research seems not matched by the pace of clinical research and clinical trial readiness. This review summarizes the author's views on the various challenges in translational research in ataxias and hopes to stimulate further thought and discussions on how to bring real help to these patients.
A novel preparation method of polyaluminum chloride/polyacrylamide composite coagulant: Composition and characteristic
Authors: Wang Xiaoping , Tang Xiaomin , Feng Ping , Li Xinyu , Zhao Chuanliang , Chen Wei , Zheng Huaili 
Published: November 2016

ABSTRACTInorganic/organic composite coagulants have drawn a wide attention through the years owing to its superior coagulation behaviors. In this study, polyaluminum chloride (PAC)/polyacrylamide (PAM) composite coagulant was synthesized by ultraviolet (UV) irradiation by using PAC and acrylamide (AM) as raw materials, urea as a solubilizer, and 2,2′‐Azobis[2‐(2‐imidazolin‐2‐yl)propane]dihydrochloride (VA‐044) as an initiator. The effect of total monomer mass fraction, solubilizer dosage and initiator dosage on the viscosity and molecular weight of PAC/PAM composite coagulant was discussed. The results suggest that the composite coagulant with high polymerization degree, intrinsic viscosity of 1483 mL/g and molecular weight of 7.38 million, could be obtained when the total monomer mass fraction of 40%, urea dosage of 1.5% and initiator dosage of 0.6% are chosen in the preparation. It is a potential preparation method of composite coagulant with short preparation time and high preparation efficiency. Fourier transform infrared spectrum and 1H nuclear magnetic resonance spectroscopy represent that the coagulant for polyaluminum chloride and polypropylene are copolymer. Thermal gravimetric analysis describes the high thermal stability of composite coagulant. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44500.
Bounded‐Input Control of the Quadrotor Unmanned Aerial Vehicle: A Vision‐Based Approach
Authors: Asl Hamed Jabbari , Yoon Jungwon 
Published: November 2016

AbstractIn this paper, a bounded‐input controller is designed for the quadrotor vertical take‐off and landing unmanned aerial vehicle (UAV). Visual information is used to localize the aircraft with respect to its environment and an image‐based visual servo scheme is developed to navigate the motion of it. The visual features are selected from perspective image moments and projected on a rotated image plane, which simplifies the controller design. The flow of the features is used as the linear velocity information, and the controller assumes angular velocity and attitude information available for feedback. To design the controller, the dynamics of the quadrotor are decoupled into two parts: translational dynamics and rotational dynamics. First visual data are used to design a bounded‐input controller for the translational dynamics, and then a saturated controller is designed for the rotational dynamics. The boundedness of the controller increases the chance of keeping the visual features in the field of view of the camera. Furthermore, the controllers also cope with the unknown depth of the image, and the external disturbances. The complete stability analysis of the overall system is presented to show that all states are bounded and the error signals converge to zero asymptotically. Simulation examples are provided in both nominal and perturbed conditions which show the effectiveness of the proposed theoretical results.
An efficient orange–red‐emitting LiNa3P2O7:Sm3+ pyrophosphate: Structural and optical analysis for solid‐state lighting
Authors: Dillip G.R. , Munirathnam K. , Raju B. Deva Prasad , Sushma N. John , Joo S.W. 
Published: November 2016

AbstractA trivalent rare‐earth ion (Sm3+)‐doped LiNa3P2O7 (LNPO) phosphor was synthesized using a conventional high‐temperature solid‐state reaction route. A predominant orthorhombic phase of LNPO was observed in all X‐ray diffraction patterns. The surface states of the LNPO:Sm phosphor were confirmed by X‐ray photoelectron spectroscopy. Under 401 nm excitation, the Sm‐doped LNPO phosphors showed sharp emission peaks at 563, 600 and 647 nm that are related to the f–f transition of Sm3+ ions. The optimum concentration of Sm3+ (9 mol%) produced Commission Internationale de l'Eclairage chromaticity coordinates, color rendering index and correlated color temperature of (0.564, 0.434), 42 and 1843 K, respectively.
Substrate specificity of an actively assembling amyloid catalyst
Authors: Heier Jason L. , Mikolajczak Dorian J. , Böttcher Christoph , Koksch Beate 
Published: November 2016

AbstractIn the presence of Zn2+, the catalytic, amyloid‐forming peptide Ac‐IHIHIQI‐NH2, was found to exhibit enhanced selectivity for hydrophobic p‐nitrophenyl ester substrates while in the process of self‐assembly. As opposed to the substrate p‐nitrophenyl acetate, which was more effectively hydrolyzed with Ac‐IHIHIQI‐NH2 in its fully fibrillar state, the hydrophobic substrate Z‐L‐Phe‐ONp was converted with a second‐order rate constant more than 11‐times greater when the catalyst was actively assembling. Under such conditions, Z‐L‐Phe‐ONp hydrolysis proceeded at a greater velocity than the more hydrophilic and otherwise more labile ester Boc‐L‐Asn‐ONp. When assembling, the catalyst also showed increased selectivity for the L‐enantiomer of Z‐Phe‐ONp. These findings suggest the occurrence of increased interactions of hydrophobic moieties of the substrate with exposed hydrophobic surfaces of the assembling peptides and present valuable features for future de novo design consideration.
Development of a targeted method for quantification of gypenoside XLIX in rat plasma, using SPE and LC–MS/MS
Authors: Guo Song , Sui Chengxu , Ma Ying 
Published: November 2016

AbstractA sensitive, selective and rapid liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed for the quantification of gypenoside XLIX, a naturally occurring gypenoside of Gynostemma pentaphyllum in rat plasma and then validated according to the US Food and Drug Administration's Guidance for Industry: Bioanalytical Method Validation. Plasma samples were prepared by a simple solid‐phase extraction. Separation was performed on a Waters XBridgeTM BEH C18 chromatography column (4.6 × 50 mm, 2.5 μm) using a mobile phase of acetonitrile and water (62.5:37.5, v/v). Gypenoside XLIX and the internal standard gypenoside A were detected in the negative ion mode using selection reaction monitoring of the transitions at m/z 1045.6 → 913.5 and 897.5 → 765.4, respectively. The calibration curve was linear (R2 > 0.990) over a concentration range of 10–7500 ng/mL with the lower quantification limit of 10 ng/mL. Intra‐ and inter‐day precision was within 8.6% and accuracy was ≤10.2%. Stability results proved that gypenoside XLIX and the IS remained stable throughout the analytical procedure. The validated LC–MS/MS method was then applied to analyze the pharmacokinetics of gypenoside XLIX after intravenous administration to rats (1.0, 2.0 and 4.0 mg/kg).