bluuebunny/crossref_metadata_2025 huggingface dataset:
Kriging for Functional Data
Authors: Giraldo Ramón , Mateu Jorge
Published: September 2014

Spatial functional data analysis is a relatively new topic in statistics. We have functional data when a random variable takes its values in a functional space and is observed at some sampling points. In this article, we focus on the case of functional data presenting spatial dependence, and present an overview of the existing methodology to make spatial predictions when the data values are functions. Kriging and its several related versions are widely known and used for spatial data. However, when the spatial data are functions, a bridge between functional data analysis and geostatistics has to be built. Ordinary kriging as well as cokriging and multivariate spatial prediction adapted to the case where the observations at each sampling location consist of samples of random functions are reviewed and compared.
Landscape Pattern Metrics
Authors: McGarigal Kevin
Published: September 2014

Real landscapes contain complex spatial patterns in the distribution of resources that vary over time; quantifying these patterns and their dynamics is the purview of landscape pattern analysis. Landscape pattern analysis involves quantifying the spatial heterogeneity of point patterns, linear networks, continuous surface patterns, and categorical patch mosaics, and sometimes custom hybridizations of these basic models, although the focus in landscape ecology and of this article has been on patch mosaics. In this context, landscape metrics are algorithms that quantify specific spatial characteristics of patches, classes of patches, or entire landscape mosaics, or of the patch mosaic in the neighborhood of each focal cell. These metrics fall into two categories: those that quantify the composition of the map without reference to spatial attributes (i.e., the variety and abundance of patch types), and those that quantify the spatial configuration of the map (i.e., the spatial character and arrangement, position, or orientation of patches within the class or landscape). Metrics are further categorized as structural metrics that measure physical structure of the mosaic without explicit reference to a particular phenomenon, or functional metrics that require additional parameterization and measure the structure of the mosaic as it relates to a specific organism or ecological process. Not surprisingly, landscape metrics are highly sensitive to landscape definition with respect to the thematic content and resolution, spatial grain and extent, and the landscape boundary. The current use and interpretation of landscape metrics is constrained by the lack of a proper theoretical understanding of metric behavior across a wide range of landscape structure gradients, the lack of a proper spatial and/or temporal reference framework for ecologically interpreting the computed value of each metric, and the challenges of choosing a parsimonious suite of metrics for a particular application given the plethora of existing metrics. Ultimately, the definition of the landscape, the establishment of a meaningful reference framework, and the choice of metrics should be based on some hypothesis about the observed landscape pattern and what processes or constraints might be responsible for that pattern. Fortunately, programs like FRAGSTATS make the calculation of landscape metrics practical and accessible to all landscape ecologists.
Monitoring, Biological
Authors: Smith Eric P.
Published: September 2014

In the environmental context, biological monitoring refers to the gathering of information on biological organisms to assess the environmental impact or the biological health of the environment. In a strict sense, the term applies to a continuing collection of data used to establish whether explicitly stated quality control conditions are being met. Other terms that are related include biological surveys, assessment, and surveillance. Biological surveys are commonly carried out by national agencies to monitor birds, whales, fish, and other organisms. Volunteer‐based surveys are an integral part of biomonitoring.
Natural Resources Modeling
Authors: Rathbun Stephen L.
Published: September 2014

Environmental resources are biotic, including fish and game populations, timber, and grasslands, or abiotic, including water, air, and soil. Interest may focus on either the quantity of available resources (e.g. volume of available timber, or size of fish populations), or their quality (e.g. the concentration of contaminants in air, water, or soil samples). Environmental resource models can lead to a better understanding of environmental processes, and assist managers in making decisions regarding sustainable levels of resource exploitation, remediation of impaired habitats, and the maintenance of biodiversity. This article describes univariate and multivariate methods for predicting the data at unsampled sites from observations at sampled sites. Univariate models are used when the values of the explanatory variables are available at all sites for which predictions are desired. A multivariate approach is required when the explanatory variables are measured only at a sample of sites. For both approaches, models for the spatial correlation structure of the data are considered, including both parametric and nonparametric forms. Methods for model fitting and spatial prediction are described.
Official Statistics, Environmental
Authors: Ross N. Phillip , Kollander Mel
Published: September 2014

The generation of
official
statistics on the environment is an evolving activity as nations begin to understand better the impact of anthropogenic environmental pollution on the state of the world's environment. Countries are experiencing increasing pressure to compete globally and to provide for the health and welfare of their human populations. These countries are realizing that proper measures of the environment are necessary for their ability to compete in the global market place and participate as members in geographic trading blocs. This pressure will have a positive effect on the production of
official
environmental statistics worldwide. In this article, we provide a brief overview of
official
statistics activities of a number of countries and international organizations that provide
official
statistics on the environment. Emphasis is on North American and European
official
statistics activities. We provide references to several web sites that provide broader information on environmental statistics for other areas of the world.
Population Dynamics
Authors: J. Quinn Terrance
Published: September 2014

Population dynamics is the study of change in an animal or fish population. Studies range from field work to collect biological data to complex mathematical and statistical models. Contemporary models attempt to achieve biological realism by containing components representing key factors affecting the population and uncertainty in those processes by adding stochastic effects. Estimation of animal abundance is an important subject and includes mark‐recapture, line‐transect, and several other methods. The simplest useful population model is the logistic, in which a population has sigmoidal growth to the carrying capacity. More complex models may include age and/or length structure, natural and harvesting mortality, recruitment of new individuals into the population, individual growth, reproductive parameters, species interactions, spatial structure, and movement. A common feature of realistic models that have an equilibrium carrying capacity is that there is density‐dependence in some population process that causes a reduction in the rate of increase as the population gets large. For example, many studies have found density‐dependence in early life survival. An important use of population dynamics models is stock assessment of fisheries. Scientists collect fisheries and biological data to estimate population parameters in assessment models that are then used to develop a sustainable harvest strategy.
P
opulation
V
iability
A
nalysis
Authors: McCarthy Michael A. , Possingham Hugh P.
Published: September 2014

Population viability analysis (PVA) assesses risks of population decline of species, and how those risks can be managed. Typically, stochastic population models are used to characterize the deterministic and stochastic components that govern changes in population size. Sources of stochasticity include demographic stochasticity due to the chance birth and death of individuals, stochasticity in the environment that is common to all individuals, chance variation in genetic composition, and spatial structure. These factors can interact to create extinction vortices that drive population decline. Predicted risks of population decline from PVA models are usually uncertain due to imprecise parameter estimates, imperfect knowledge about factors that influence dynamics, and uncertainty about future conditions. Despite these sources of uncertainty, changes in risks due to management can be predicted more reliably. Using these changes in risk, PVA can help determine efficient management strategies for reducing high contemporary rates of extinction.
Predictive Scores
Authors: Gneiting Tilmann
Published: September 2014

Predictive scores assess the quality of forecasts, by assigning a numerical score based on the forecast and on the event or value that materializes. Probabilistic forecasts take the form of a predictive probability distribution. Their evaluation calls for the use of proper scoring rules, such as the logarithmic score or the continuous ranked probability score. Effective point forecasting requires a directive in the form of a target functional, say a quantile or the mean of the predictive distribution. It is then critical for the scoring function to be decision theoretically consistent, so that the expected score is minimized when following the directive. For example, the squared error is consistent when the point forecast is desired to be a mean, and the absolute error is consistent when we seek a median.
Satellite Data
Authors: Shao Guofan
Published: September 2014

Earth observation satellites collect data relevant to a wide range of land resource topics and there are a variety of satellite data that are designed for different purposes. Satellite data are collected, transmitted, stored, and analyzed in digital forms. Satellite data have a broad range of spatial, spectral, radiometric, and temporal characteristics. Commonly used terms are spatial, spectral, radiometric, and temporal resolutions. A general indication of advancement of satellite data is that their resolutions are getting higher over time. Satellite can be used alone, to derive new data, and integrated with other geospatial data sources. While most of commercial satellite data can be purchased from data providers, many governmental satellite data can be downloaded without charge from US government websites.
Screening Effect, Geostatistical
Authors: Du Juan
Published: September 2014

This article reviews various applications and some theory of the screening effect, which describes the phenomenon where a spatial interpolant primarily depends on nearby observations in kriging. Justified by the screening effect, the nearest‐neighbor approach has been widely used in practice, mainly to reduce computational burden. However, caution needs to be exercised in choosing model and observation locations, since there may be no screening effect in some cases.
Seemingly Unrelated Regressions
Authors: Bartels R.
Published: September 2014

Seemingly unrelated regression (SUR) is a widely used modeling approach introduced by Zellner for situations where several linear regression relationships are being investigated at the same time. Examples of the use of SUR in environmetrics include Boisvert et al., who considered separate equations for the effect of water contamination on both the purchase price and rental value of farmland, and Xu, who estimated separate equations for the impact of environmental legislation on the output of each of a number of industrial sectors. The key feature in these cases is that each of the linear equations, on its own, satisfies the classical conditions underpinning the linear regression model, and hence the ordinary least squares (OLS) estimator can be used to estimate each equation individually. However, if the error terms of the different equations are correlated across the equations, then joint estimation of the equations may be able to exploit this cross equation correlation to obtain more efficient estimates.
Soil Surveys
Authors: Brus Dick J. , Lark Richard Murray
Published: September 2014

The aim of a soil survey is to predict soil conditions at unvisited sites. In traditional soil survey, the use of statistics is principally for
post hoc
evaluation of the quality of the choropleth map in terms of purity and within‐ and between‐map unit variance of soil properties. Probability sampling designs have been proposed for this. Pedometrical soil surveys treat all phases of the soil survey explicitly as a statistical problem. This had led to the adoption and development of, amongst other techniques, optimized sampling for mapping purposes, automated fuzzy classification of soil profiles, and geostatistical interpolation. Typically covariates related to the soil‐forming factors and derived from remotely sensed images or digital elevation models are integrated into the geostatistical prediction.
Spatial Analysis in Ecology
Authors: Fortin Marie‐josée , Dale Mark R.T. , Ver Hoef Jay M.
Published: September 2014

The first step in understanding ecological processes is to identify patterns. Ecological data are usually characterized by spatial structures due to spatial autocorrelation.
Spatial autocorrelation
refers to the pattern in which observations from nearby locations are more likely to have similar magnitude than by chance alone. The magnitude, intensity, as well as extent of spatial autocorrelation can be quantified using spatial statistics. Most ecological data exhibit some degree of spatial autocorrelation, depending on the scale at which the data were recorded and then analyzed. Ecological phenomena are also characterized by the multiple ecological processes that act upon them; these processes often operate at more than one spatial scale. Ecological data are a composite of several spatial scales: trends at macroscales; patches, gradients and patterns at meso‐ and local scales; and random patterns at local and microscales. The different processes and patterns at different scales are not necessarily linear or additive, and this contributes to the degree of spatial dependence in the data.
Species Competition
Authors: Young Linda J.
Published: September 2014

Competition occurs when the interaction of two organisms has an adverse effect on both. The primary models for competition are based on the Lotka‐Volterra equations. Replacement series experiments are a standard approach to evaluating the competitive relationships of two or more species. Measures of niche overlap, such as similarity indices, are often used as initial indicators of competition although they are recognized not to be true measures of competition. The probability of a species being present may be related to environmental variables and the presence of other species using logistic regression.
Species Interaction Networks
Authors: Chiu Grace S.
Published: September 2014

To gain insight into the food web structure through analysis of empirical food webs, it is necessary to disentangle the complex interdependence among the species interactions that form the food web. This article reviews some basics for making sense of species trophic (feeding) interactions and any associated nonconsumption information. It then provides some details of a more novel statistical‐model‐based social network analysis approach. The inference for food web structure resulting from the single rigorous quantitative analysis incorporates trophic data and any available nontrophic data, and accounts for uncertainty inherent in the data. The inference can reveal trophic patterns simultaneously from three different perspectives of feeding behavior: trophic activity, predator's preference, and so‐called prey's preference.
Species Richness
Authors: Gerow Kenneth
Published: September 2014

Species richness (i.e., number of species present) is a tantalizingly simple parameter that is exceedingly difficult to estimate well, primarily because of the bedeviling role of rare and hard to detect species. The collection of estimation approaches is rich, eclectic, and diverse, with no single method standing out as always best.
Standards, Environmental
Authors: Esterby Sylvia
Published: September 2014

This article describes the past, present, and future techniques by which environmental standards are set. Concern regarding the lack of acknowledgment of uncertainty and variability in many standards, and thus in reported results on compliance, has lead to an emphasis on the role of statistical methodology in environmental standard setting. Research into the feasibility, advantages, and disadvantages of such methodology is ongoing, but much remains to be done. Encompassing within its line of investigation areas, such as toxicology, environmental sampling methodology, and spatiotemporal modeling, and affecting the fundamental procedures of industry, traffic management, medical and environmental agencies, to name just a few of many, this area of the rapidly growing field of environmetrics may prove to be one of the most far‐reaching and important statistical applications in the coming years.
Surveillance, Environmental
Authors: Järpe Eric
Published: September 2014

In many environmental random processes it is relevant to consider a sudden shift in a parameter of the probability distribution of the random variables. This parameter may be a mean level of the process or the natural variation of the variables. Suddenly the parameter can shift to some other, commonly higher, value or to another, commonly increasing, function in time and/or space. To prevent or mitigate the fatal consequences such shifts could imply, it is often of utter importance to detect the change as accurately and quickly as possible. Therefore, stopping rules which are functions of the random process data observed are evaluated, on‐line or retrospectively, in order to indicate a systematic change. Different shift processes are mentioned. An example with data from the Swedish Radiation Safety Authority is given.
Switching Process
Authors: Shumway Robert H.
Published: September 2014

Often, there is a need to develop models that describe environmental processes that change regimes at unknown points in time or space. Dynamic regression or state–space models that are switching from one regime to the other according to an evolving stationary discrete state Markov chain have great potential for modeling changing environmental phenomena. Processes that involve these kinds of models are often referred to as
switching processes
or hidden Markov processes.
Tail Dependence Functions, Statistical Inference for
Authors: Peng Liang , Zhang Zhengjun
Published: September 2014

Predicting extreme events plays an important role in environmental risk management. Tail dependence functions are naturally adopted in statistical inference of extreme events. In this article, we review some methodologies proposed in the literature.
Threshold Models
Authors: Drees Holger
Published: September 2014

Models for exceedances over high thresholds are motivated by limit theorems from extreme value theory. For univariate observations this approach leads to generalized Pareto models. In contrast, natural models for the dependence of vectors of exceedances are infinite dimensional.
Uncertainty Analysis
Authors: Smith Eric P.
Published: September 2014

Mathematical, statistical, and other models are often developed to aid researchers and management in making decisions about environmental problems and the associated risk. Uncertainty analysis is associated with a set of methods to aid in understanding the limitations in the decision process and predictions from these models. Uncertainty is typically associated with deterministic (model, parameter) and stochastic (variation) components. Several methods for estimating the uncertainty such as Monte Carlo methods, frequentist and Bayesian analysis, and sensitivity analysis are described. Common problems in uncertainty such as safety and extrapolation factors, decision making under uncertainty, and estimation of uncertainty are discussed.
Weather Prediction
Authors: Lin Charles
Published: September 2014

At the heart of the weather forecast procedure is the numerical weather prediction model. The governing equations are the equations for the three spatial components of momentum, temperature, humidity and mass. The model is made from a spatial discretization of the governing equations on the entire globe using numerical methods (e.g. finite difference and spectral methods). The finite model grid size means that parameterizations of physical processes such as mixing and convective adjustment are necessary. Such models typically have millions of degrees of freedom, and frequently require supercomputers for their efficient solution. The equations are integrated forward in time, again using numerical methods, starting from some initial state. Global forecasts of meteorological quantities such as surface temperature and precipitation are made for up to about two weeks.
Flow Over Complex Terrain, Numerical Modeling of
Authors: Lundquist Katherine A. , Chow Fotini Katopodes
Published: September 2014

This article provides a general description of numerical modeling over complex terrain, including both diagnostic and prognostic approaches and their associated advantages and limitations. Diagnostic models solve simplified versions of the equations of motion and are widely used in the engineering community for simulations of flow over complex terrain. These models produce a description of the steady‐state flow, while requiring few inputs and being computationally efficient. Diagnostic models do not predict time evolution of flow, and are often only appropriate for terrain with small slopes. Prognostic models solve the full equations of motion and are used for both engineering and numerical weather prediction applications. Details of the implementation of prognostic models vary widely, but they are capable of producing time‐varying descriptions of the flow and handling very complex terrain with no limitations on terrain slope. These models can require detailed three‐dimensional inputs and large computational resources. Additional simplifications can reduce these requirements, but generally at the expense of functionality, such as producing a steady‐state solution or the inability to handle arbitrarily complex terrain.
Uncertainty Quantification, Physical Models
Authors: He Xian , Zhang Hao
Published: September 2014

A physical model refers to a deterministic mathematical model that is built partially based upon physical or biological principles. Because it is deterministic, it is vital to quantify the uncertainty of its output. The ensemble is a common method for a model whose output can be simulated efficiently. For those models that are more computationally demanding to simulate, statistical emulation and stochastic differential models are two useful approaches. This article briefly reviews these methods.
Exceedance Over Threshold
Authors: Drees Holger
Published: September 2014

We consider methods from extreme value statistics to fit threshold models to univariate or multivariate samples. Moreover, the influence of serial dependence between observations on the estimation accuracy and on quantities of interest, such as return levels, is discussed.
Ortho‐ vs Bay‐Functionalization: A Comparative Study on Tetracyano‐Terrylenediimides
Authors: Battagliarin Glauco , Puniredd Sreenivasa Reddy , Stappert Sebastian , Zajaczkowski Wojciech , Wang Suhao , Li Chen , Pisula Wojciech , Müllen Klaus
Published: September 2014

In this paper n‐type semiconductors synthesized via selective fourfold cyanation of the ortho‐ and bay‐positions (2,5,10,13‐ and 1,6,9,14‐positions respectively) of teyrrylenediimides are reported. A detailed study about the impact of the diverse functionalization topologies on the optoelectronic properties, self‐organization from solution, solid‐state packing, and charge carrier transport in field‐effect transistors is presented. The ortho‐substitution preserves the planarity of the core and favors high order in solution processed films. However, the strong intermolecular interactions lead to a microstructure with large aggregates and pronounced grain boundaries which lower the charge carrier transport in transistors. In contrast, the well‐soluble bay‐functionalized terrylenediimide forms only disordered films which surprisingly result in n‐type average mobilities of 0.17 cm2/Vs after drop‐casting with similar values in air. Processing by solvent vapor diffusion enhances the transport to 0.65 cm2/Vs by slight improvement of the order and surface arrangement of the molecules. This mobility is comparable to highest n‐type conductivities measured for solution processed PDI derivatives demonstrating the high potential of TDI‐based semiconductors.
Organic Electrochemical Transistors for Clinical Applications
Authors: Leleux Pierre , Rivnay Jonathan , Lonjaret Thomas , Badier Jean‐Michel , Bénar Christian , Hervé Thierry , Chauvel Patrick , Malliaras George G.
Published: September 2014

The ability of organic electrochemical transistors is explored to record human electrophysiological signals of clinical relevance. An organic electrochemical transistor (OECT) that shows a high (>1 mS) transconductance at zero applied gate voltage is used, necessitating only one power supply to bias the drain, while the gate circuit is driven by cutaneous electrical potentials. The OECT is successful in recording cardiac rhythm, eye movement, and brain activity of a human volunteer. These results pave the way for applications of OECTs as an amplifying transducer for human electrophysiology.
More nonlocality with less entanglement in a tripartite atom‐optomechanical system
Authors: Zhang Jing , Zhang Tiancai , Xuereb André , Vitali David , Li Jie
Published: September 2014

Quantum effects in hybrid atomic optomechanics in a system comprising a cloud of atoms and a mobile mirror mediated by a single‐mode cavity are studied. Tripartite nonlocality is observed in the atom‐light‐mirror system, as demonstrated by the violation of the Mermin‐Klyshko (MK) inequality. It has been shown [C. Genes, et al., PRA 77, 050307 (R) (2008)] that tripartite entanglement is optimized when the cavity is resonant with the anti‐Stokes sideband of the driving laser and the atomic frequency matches the Stokes one. However, we show that this is not the case for the nonlocality. The MK function achieves minima when the atoms are resonant with both the Stokes and anti‐Stokes sidebands, and unexpectedly, we find violation of the MK inequality only in a parameter region where entanglement is far from being maximum. A negative relation exists between nonlocality and entanglement with consideration of the possibility of bipartite nonlocality in the violation of the MK inequality. We also study the non‐classicality of the mirror by post‐selected measurements, e.g. Geiger‐like detection, on the cavity and/or the atoms. We show that with feasible parameters Geiger‐like detection on the atoms can effectively induce mechanical non‐classicality.
Assessment of cytochrome P450‐mediated drug–drug interaction potential of orteronel and exposure changes in patients with renal impairment using physiologically based pharmacokinetic modeling and simulation
Authors: Lu Chuang , Suri Ajit , Shyu Wen Chyi , Prakash Shimoga
Published: September 2014

Orteronel is a nonsteroidal, selective inhibitor of 17,20‐lyase that was recently in phase 3 clinical development as a treatment for castration‐resistant prostate cancer. In humans, the primary clearance route for orteronel is renal excretion. Human liver microsomal studies indicated that orteronel weakly inhibits CYP1A2, 2C8, 2C9 and 2C19, with IC50 values of 17.8, 27.7, 30.8 and 38.8 µm, respectively, whereas orteronel does not inhibit CYP2B6, 2D6 or 3A4/5 (IC50 > 100 µm). Orteronel also does not exhibit time‐dependent inhibition of CYP1A2, 2B6, 2C8, 2C9, 2C19, 2D6 or 3A4/5. The results of a static model indicated an [I]/Ki ratio >0.1 for CYP1A2, 2C8, 2C9 and 2C19. Therefore, a physiologically based pharmacokinetic (PBPK) model was developed to assess the potential for drug–drug interactions (DDIs) between orteronel and theophylline, repaglinide, (S)‐warfarin and omeprazole, which are sensitive substrates of CYP1A2, 2C8, 2C9 and 2C19, respectively. Simulation of the area under the plasma concentration–time curve (AUC) of these four CYP substrates in the presence and absence of orteronel revealed geometric mean AUC ratios <1.25. Therefore, in accordance with the 2012 US FDA Draft Guidance on DDIs, orteronel can be labeled a ‘non‐inhibitor’ and further clinical DDI evaluation is not required. In PBPK models of moderate and severe renal impairment, the AUC of orteronel was predicted to increase by 52% and 83%, respectively. These results are in agreement with those of a clinical trial in which AUC increases of 38% and 87% were observed in patients with moderate and severe renal impairment, respectively. Copyright © 2014 John Wiley & Sons, Ltd.
A highly selective and simple fluorescent sensor for mercury (II) ion detection based on cysteamine‐capped CdTe quantum dots synthesized by the reflux method
Authors: Ding Xiaojie , Qu Lingbo , Yang Ran , Zhou Yuchen , Li Jianjun
Published: September 2014

Cysteamine (CA)‐capped CdTe quantum dots (QDs) (CA–CdTe QDs) were prepared by the reflux method and utilized as an efficient nano‐sized fluorescent sensor to detect mercury (II) ions (Hg2+). Under optimum conditions, the fluorescence quenching effect of CA–CdTe QDs was linear at Hg2+ concentrations in the range of 6.0–450 nmol/L. The detection limit was calculated to be 4.0 nmol/L according to the 3σ IUPAC criteria. The influence of 10‐fold Pb2+, Cu2+ and Ag+ on the determination of Hg2+ was < 7% (superior to other reports based on crude QDs). Furthermore, the detection sensitivity and selectivity were much improved relative to a sensor based on the CA–CdTe QDs probe, which was prepared using a one‐pot synthetic method. This CA–CdTe QDs sensor system represents a new feasibility to improve the detection performance of a QDs sensor by changing the synthesis method. Copyright © 2014 John Wiley & Sons, Ltd.
Simple and sensitive LC‐MS/MS‐based assay for the quantification of dimemorfan in human plasma for use in a pharmacokinetic study
Authors: Tan Hongyi , Peng Jinfu , Pei Qi , Yang Liu , Chen Jun , Guo Chengxian , Hua Ye , Yuan Hong , Yang Guoping
Published: September 2014

Dimemorfan phosphate has been widely used for 40 years throughout the world for the treatment of coughs. This is the first report on the use of an LC‐MS/MS‐based assay for the determination of dimemorfan in human plasma using estazolam as an internal standard after one‐step protein precipitation with acetonitrile. Chromatographic separation was achieved on a Phenomenex Luna C18 column (3 µm, 50 × 2.0 mm) using a fast gradient method, which involves water and methanol as the mobile phase (both containing 0.1% formic acid). Dimemorfan and estazolam were detected with proton adducts at m/z values of 255.8 → 155.1 and 295.0 → 267.0, respectively, in the selected reaction monitoring positive mode. The linear dynamic range of the assay was 0.04–5.00 ng/mL. The chromatographic run time for each plasma sample was <5 min. The method was proven to be accurate, precise, and repeatable. Finally, the developed method was successfully applied for the determination of dimemorfan in a pharmacokinetic study using healthy Chinese subjects. Copyright © 2014 John Wiley & Sons, Ltd.
Childhood maltreatment and amygdala connectivity in methamphetamine dependence: a pilot study
Authors: Dean Andy C. , Kohno Milky , Hellemann Gerhard , London Edythe D.
Published: September 2014

Introduction

Childhood maltreatment, a well‐known risk factor for the development of substance abuse disorders, is associated with functional and structural abnormalities in the adult brain, particularly in the limbic system. However, almost no research has examined the relationship between childhood maltreatment and brain function in individuals with drug abuse disorders.

Methods

We conducted a pilot study of the relationship between childhood maltreatment (evaluated with the Childhood Trauma Questionnaire; Bernstein and Fink 1998) and resting‐state functional connectivity of the amygdala (bilateral region of interest) with functional magnetic resonance imaging in 15 abstinent, methamphetamine‐dependent research participants. Within regions that showed connectivity with the amygdala as a function of maltreatment, we also evaluated whether amygdala connectivity was associated positively with negative affect and negatively with healthy emotional processing.

Results

The results indicated that childhood maltreatment was positively associated with resting‐state connectivity between the amygdala and right hippocampus, right parahippocampal gyrus, right inferior temporal gyrus, right orbitofrontal cortex, cerebellum, and brainstem. Furthermore, connectivity between the amygdala and hippocampus was positively related to measures of depression, trait anxiety, and emotion dysregulation, and negatively related to self‐compassion and dispositional mindfulness.

Conclusions

These findings suggest that childhood maltreatment may contribute to increased limbic connectivity and maladaptive emotional processing in methamphetamine‐dependent adults, and that healthy emotion regulation strategies may serve as a therapeutic target to ameliorate the associated behavioral phenotype. Childhood maltreatment warrants further investigation as a potentially important etiological factor in the neurobiology and treatment of substance use disorders.
Design, Synthesis, Photophysical Studies and Electrochemistry of Carbazole‐, Oxadiazole‐, and Oxadiazole‐Triarylamine‐Containing Rhenium(I) Diimine Alkynyl Complexes
Authors: Chung Wai‐Kin , Wong Keith Man‐Chung , Yam Vivian Wing‐Wah
Published: September 2014

A series of rhenium(I) diimine alkynyl complexes with various electron‐ and hole‐transporting moieties has been synthesized and characterized. Their electronic absorption, emission and electrochemical properties have also been studied.
Palladium‐Catalyzed 2H‐1,2,3‐Triazole‐Directed Oxidative Alkoxylation of Arenes with Alcohols
Authors: Shi Wenjuan , Shi Zhangjie
Published: September 2014

A palladium catalyzed ortho‐alkoxylation of aryl CH bond was accomplished with primary and secondary alcohols as alkoxylation reagents and with triazole as new directing group. This transformation has a good functional group tolerance and is not sensitive to moisture and air.
Minimum Amount of Extracting Solvent of (A1A2···At−1)/(A2A3···At) Separation When Using Non‐barren Extracting Solvent
Authors: Cheng Fu‐Xiang , Wu Sheng , Wang Song‐Ling , Zhang Bo , Liu Yan , Liao Chun‐Sheng , Yan Chun‐Hua
Published: September 2014

Hyperlink extraction technology, by virtue of its remarkable advantage of decreasing the use of chemicals in multi‐component separation, has been extensively employed in rare earth separation industry in China. In hyperlink processes, non‐barren extracting solvent and scrubbing agent solution which contain the component(s) involved in starting feed are employed in order to save both alkali for saponification and acid for scrubbing. Minimum amount of extracting solvent (denoted as Smin) and that of scrubbing agent solution (denoted as Wmin) are important parameters to determine the consumption amounts of alkali and acid for a given countercurrent extraction separation. This article therefore discusses the influence of using non‐barren extracting solvent and scrubbing agent solution on Smin and Wmin of an (A1A2···At−1)/(A2A3···At) separation. The equations for Smin and Wmin are derived, and the variation of the composition of final raffinate as well as that of final extract are determined, which will provide a valuable guidance for the design of hyperlink extraction processes of multi‐component separation, such as rare earths separation.
Formaldehyde‐fixation of platelets for flow cytometric measurement of phosphatidylserine exposure is feasible
Authors: Rochat Sophie , Alberio Lorenzo
Published: September 2014

Strong platelet activation results in a redistribution of negatively charged phospholipids from the cytosolic to the outer leaflet of the cellular membrane. Annexin V has a high affinity to negatively charged phospholipids and can be used to identify procoagulant platelets. Formaldehyde fixation can cause factitious Annexin V binding. Our aim was to evaluate a method for fixing platelets avoiding additional Annexin V binding. We induced expression of negatively charged phospholipids on the surface of a fraction of platelets by combined activation with convulxin and thrombin in the presence of Annexin V‐fluorescein isothiocyanate and calcium. Aliquots of resting and activated platelets were fixed with a low concentration, calcium‐free formaldehyde solution. Both native platelets and fixed platelets were analyzed by flow cytometry immediately and after a 24‐h storage at 4°C. We observed that the percentage of Annexin V positive resting platelets ranged from 1.5 to 9.3% for the native samples and from 0.4 to 12.8% for the fixed samples (P = 0.706, paired t‐test). The amount of Annexin V positive convulxin/thrombin activated platelets varied from 12.9 to 35.4% without fixation and from 15.3 to 36.3% after formalin fixation (P = 0.450). After a 24‐h storage at 4°C, Annexin V positive platelets significantly increased both in the resting and in the convulxin/thrombin activated samples of native platelets (both P < 0.001), while results for formalin fixed platelets did not differ from baseline values (P = 0.318 for resting fixed platelets; P = 0.673 for activated fixed platelets). We conclude that platelet fixation with a low concentration, calcium‐free formaldehyde solution does not alter the proportion of Annexin V positive platelets. This method can be used to investigate properties of procoagulant platelets by multicolor flow‐cytometric analysis requiring fixation steps. © 2014 International Society for Advancement of Cytometry
Asymmetric Mannich Reaction of Malonates with Aldimines Using YbIII‐Pybox Complexes Supported on Self‐Assembled Organic–Inorganic Hybrid Silica with an Imidazolium Framework
Authors: Karimi Babak , Jafari Ehsan , Enders Dieter
Published: September 2014

Yb(OTf)3/iPr‐pybox (3b) immobilized on a self‐assembled organic–inorganic hybrid silica with ionic liquid phase (SAILP) (Catalyst A) behaves as an efficient and recyclable catalyst in the enantioselective Mannich reaction of malonate esters with N‐Boc aldimines to afford the corresponding products in good yields and enantioselectivities. In particular, it has been shown that the use of catalyst A resulted in much superior enantioselectivities in comparison with either 1:2 Yb(OTf)3/3b on a periodic mesoporous organosilica with 10 percent imidazolium framework (catalyst C) or a catalyst comprising 1:1 Yb(OTf)3/3b on SAILP under the same reaction conditions. Catalyst A could be recycled and reused at least four times with only a slight decrease in either catalytic activity or enantioselectivity.
Enhanced Photochemical Sensitivity in Photochromic Diarylethenes Based on a Benzothiophene/Thiophene Nonsymmetrical Structure
Authors: Galangau Olivier , Kimura Yuka , Kanazawa Rui , Nakashima Takuya , Kawai Tsuyoshi
Published: September 2014

Photosensitivity of molecules is one of the central subjects of organic photochemistry. In this article, we present how and why a benzothiophene moiety impacts the photochromic quantum yield for the photochemical pericyclic ring closing of the hexatriene moiety. Two compounds were prepared: a symmetrical one incorporating two fluorenylthiophene units, and its corresponding nonsymmetrical partner, where one of the thiophene units was replaced by a benzothiophene group. Interestingly, the latter presents relatively high cyclization quantum yield (0.74), a value close to the largest one so far reported. Based on crystal structures, VT‐NMR data and DFT calculations, we demonstrate that introducing a benzothiophene in the molecular scaffold induces skeleton stiffening by means of CH–π interactions and steric repulsions, and leads to increased population of the reactive conformer in the ambient conditions.
Solution‐ and Solid‐State Luminescent Borate Complexes Based on a Substituted π‐Conjugated 2‐(6′‐Hydroxy‐5′‐benzofuryl) Scaffold
Authors: Benelhadj Karima , Massue Julien , Retailleau Pascal , Chibani Siwar , Le Guennic Boris , Jacquemin Denis , Ziessel Raymond , Ulrich Gilles
Published: September 2014

This paper describes the synthesis of π‐conjugated fluorophores based either on an anil or a benzoxazole scaffold incorporating a rigid 2‐(6′‐hydroxy‐5′‐benzofuryl) fragment. Their subsequent coordination to a BF2 motif led to highly luminescent BIII complexes called boranils or HBBO borate complexes, respectively. All the new compounds were characterized by NMR spectroscopy, mass spectrometry, and elemental analysis. The study of their optical properties in solution revealed two distinct photophysical behaviors depending on the substitution. Complexes bearing a strong electron‐donating p‐nBu2NC6H4 group displayed a marked internal charge transfer (ICT) leading to a pronounced solvatochromism with λem ranging from 507 to 663 nm and quantum yields of up to 87 %. Alternatively, borate complexes functionalized with p‐tBuC6H4 or p‐OMeC6H4 displayed fluorescence in the visible range that is not influenced by the nature of the solvent. Although the emission of the boranils was quenched in the solid state, HBBO borate complexes displayed intense fluorescence from 489 to 567 nm and quantum yields of up to 23 %. Finally, the excited states of a selection of borate complexes were modeled by using time‐dependent DFT, which allowed calculation of the dipole moments of the dyes in their excited states.
Copper‐Catalyzed Asymmetric Addition to Isatins to give 3‐Hydroxy‐2‐oxindoles by C–H Activation
Authors: Deng Tao , Wang Hongjun , Cai Chun
Published: September 2014

A copper‐catalyzed asymmetric addition to isatins to give 3‐hydroxy‐2‐oxindoles by C–H activation with a fluorous bis(oxazoline) as ligand is presented. The corresponding products were obtained in 35–66 % yields with enantioselectivities up to 92 %. The fluorous ligand can be easily recovered and reused at least three times without significant loss in its activity.
Chiral selectors in CE: Recent developments and applications (2012‐mid 2014)
Authors: Stavrou Ioannis J. , Mavroudi Maria C. , Kapnissi‐Christodoulou Constantina P.
Published: September 2014

There is a large number of chiral selectors (CSs) that have, over the years, been synthesized and used in electrophoretic enantioseparations. This report highlights the most important CSs applied in CE during the period 2012 to mid‐2014. It is mainly focused on method developments and validations, along with pharmaceutical and biomedical applications. Even though numerous publications have, through the years, reported the utilization of CSs in enantioseparations, only the ones applied in electrophoretic techniques the last approximately three years are demonstrated in this review article. In particular, cyclodextrins, cyclofructants, linear and branched oligo‐ and polysaccharides, antibiotics, and polymeric surfactants are presented, and their advantages, their chiral recognition mechanisms, and their performance are discussed.
Recent development of hybrid organic‐silica monolithic columns in CEC and capillary LC
Authors: Ou Junjie , Liu Zhongshan , Wang Hongwei , Lin Hui , Dong Jing , Zou Hanfa
Published: September 2014

As an attractive alternative to organic and silica monoliths, hybrid organic–inorganic monolith somewhat combines the advantages of them, such as high surface area, excellent mechanical strength, and thermal stability. We have reviewed the preparation and application of hybrid monoliths in 2011 and 2013. The preparation approaches have been mainly summarized into three categories: (1) common sol–gel process using trialkoxysilanes and tetraalkoxysilanes as precursors; (2) “one‐pot” process of alkoxysilanes and organic monomers simultaneously via sol–gel chemistry and free radical polymerization; and (3) other polymerization of silane‐containing monomers. Herein, we would focus on the recent progress and development of preparation approaches, mainly covering the literatures since July of 2012. First, the direct synthesis approach of hybrid monoliths via sol–gel chemistry and following postmodification was an important route to fabricate various monolithic stationary phases, particularly, to modify the hybrid monoliths containing amino, epoxy, vinyl, and other groups. Second, “one‐pot” process, as a novel preparation approach of hybrid monoliths, was further developed in the past 2 years, in which various organic functional monomers, not only water‐soluble monomers, but also hydrophobic monomers could be added in the preparation system. Other polymerization techniques in the preparation of organic monolithic materials, particularly, free radical polymerization and ring‐opening polymerization, were successfully transferred to fabricate the hybrid monoliths by using silane‐containing monomers including POSS monomers or other self‐synthesized monomers.
An improvement for multidimensional characteristic‐based scheme by using different selected waves
Authors: Fathollahi Reza , Zamzamian Kamiar
Published: September 2014

In this study, an improved multidimensional characteristic‐based (MCB) scheme, used for calculation of incompressible flows via artificial compressibility method, is presented. The new idea uses four different waves instead of traditional waves, which were used in the original MCB scheme corresponding to coordinate axes. In the new selection of waves, the number of compatibility relations is increased to eight, and therefore, more information reaches to each face in order to estimate convective fluxes. Numerical tests show that the new improved MCB scheme is faster in terms of convergence and demonstrates the same accuracy by the older one. Also, it needs less CPU time in comparison with traditional MCB scheme for running the computer code at the same conditions. The new scheme is able to use higher CFL numbers compared with the old MCB scheme. Results obtained by the new proposed method are in good agreement with the benchmark solutions at the wide range of Reynolds numbers. Copyright © 2014 John Wiley & Sons, Ltd.