bluuebunny/crossref_metadata_2025 huggingface dataset:
Inverted barometer contributions to recent sea level changes along the northeast coast of North America
Authors: Piecuch Christopher G. , Ponte Rui M.
Published: June 2015

Regional sea level (SL) changes reflect dynamic and isostatic ocean effects. Recent works have interpreted accelerated and extreme SL changes along the northeast coast of North America primarily in terms of dynamic changes; however, dedicated study of isostatic changes related to surface atmospheric pressure loading—the inverted barometer (IB) effect—has been lacking. This investigation uses five different atmospheric pressure products to analyze the influence of the IB effect on annual mean SL from tide gauge records. The IB effect explains ∼25% of interannual SL variance and accounts for ∼50% of the magnitude of a recent extreme event of SL rise along Atlantic Canada and New England. Estimated IB effects also amount to ∼10–30% of recent multidecadal SL accelerations over the Mid‐Atlantic Bight and Southern New England. These findings reiterate the need for careful estimation and removal of isostatic effects for studies of dynamic SL.
Grain growth and transformation of pedogenic magnetic particles in red Ferralsols
Authors: Long Xiaoyong , Ji Junfeng , Balsam William , Barrón Vidal , Torrent José
Published: June 2015

Soil magnetism depends on the mineral composition and grain size distribution of magnetic particles. The accumulation of magnetic particles with different grain sizes has been found in the laboratory to precede the formation of hematite (Hm), which competes with goethite (Gt) in natural systems. To explore changes in the correlation between magnetic particles and Hm during pedogenesis, we focus on three representative red Ferrasol profiles with comparable total concentrations of iron oxides but different Hm/(Hm + Gt) ratios, from 0.14 to 0.74. Superparamagnetic particles and single‐domain particles commonly become enriched as the concentration of Hm increases in the profiles. However, the accumulation rates of the particles decrease with Hm/(Hm + Gt) along the profiles. We attributed these changes to the simultaneous grain growth of pedogenic magnetic particles and their partial transformation into Hm once a large amount of pedogenic magnetic particles have accumulated in hematitic soils.
Recent spatiotemporal patterns in temperature extremes across conterminous United States
Authors: Mutiibwa Denis , Vavrus Steven J. , McAfee Stephanie A. , Albright Thomas P.
Published: June 2015

With a warming climate, understanding the physical dynamics of hot and cold extreme events has taken on increased importance for public health, infrastructure, ecosystems, food security, and other domains. Here we use a high‐resolution spatial and temporal seamless gridded land surface forcing data set to provide an assessment of recent spatiotemporal patterns in temperature extremes over the conterminous United States (CONUS). We asked the following: (1) How are temperature extremes changing across the different regions of CONUS? (2) How do changes in extremes vary on seasonal, annual, and decadal scales? (3) How do changes in extremes relate to changes in mean conditions? And (4) do extremes relate to major modes of ocean‐atmosphere variability? We derive a subset of the CLIMDEX extreme indices from the North American Land Data Assimilation phase 2 forcing data set. While there were warming trends in all indices, daytime temperature extremes warmed more than nighttime. Spring warming was the strongest and most extensive across CONUS, and summer experienced the strongest and most extensive decrease in cold extremes. Increase in winter warm extremes appeared weakening relative to the rapid 1950–1990 increase found in previous studies. The Northeast and Midwest experienced the most warming, while the Northwest and North Great Plains saw the least. We found changes in average temperatures were more associated with changes in cold extremes than warm extremes. Since 2006 there have been 5 years when more than 5% of the U.S. experienced at least 90 warm days, something not observed in the previous 25 years. The unusually warm first decade of 21st century could have been associated with the warm conditions of near El Niño–Southern Oscillation‐neutral phase of the decade, and possibly amplified by anthropogenic forcing. The widespread, lengthy, and severe extreme hot events documented here during the past three decades underscore the need to implement thoughtful adaptation plans in the very near future, to the growing evidence of increasing warm extremes across United States.
Subglacial hydrology and ice stream margin locations
Authors: Perol Thibaut , Rice James R. , Platt John D. , Suckale Jenny
Published: June 2015

Fast‐flowing ice streams in West Antarctica are separated from the nearly stagnant ice in the adjacent ridge by zones of highly localized deformation known as shear margins. It is presently uncertain what mechanisms control the location of shear margins and possibly allow them to migrate. In this paper we show how subglacial hydrological processes can select the shear margin location, leading to a smooth transition from a slipping to a locked bed at the base of an ice stream. Our study uses a two‐dimensional thermomechanical model in a cross section perpendicular to the direction of flow. We confirm that the intense straining at the shear margins can generate large temperate regions within the deforming ice. Assuming that the melt generated in the temperate ice collects in a drainage channel at the base of the margin, we show that a channel locally decreases the pore pressure in the subglacial till. Therefore, the basal shear strength just outside the channel, assuming a Coulomb‐plastic rheology, can be substantially higher than that inferred under the majority of the stream. Results show that the additional basal resistance produced by the channel lowers the stress concentrated on the locked portion of the bed. Matching the model to surface velocity data, we find that shear margins are stable when the slipping‐to‐locked bed transition occurs less than 500 m away from a channel operating at an effective pressure of 200 kPa and for a hydraulic transmissivity equivalent to a basal water film of order 0.2 mm thickness.
Actuarial Science
Authors: Klugman Stuart
Published: June 2015

Actuarial science is an applied mathematical and statistical discipline in which data‐driven models are constructed to quantify and manage financial risk. The termactuarial statisticsis not in common use because a well‐defined set of statistical techniques useful to actuaries has not been established. This article could also be viewed as a discussion of the types of data (mortality, morbidity, accident frequency, and severity) collected by actuaries but that will not be the focus in this article. This article concentrates on three particular statistical endeavors in which actuaries have played a major role – construction of mortality tables, credibility theory, and estimation of outstanding claims and their variability.
Data Masking for Disclosure Limitation
Authors: Massell Paul B. , Freiman Michael H. , McKenna Laura V.
Published: June 2015

Governmental agencies that conduct surveys and censuses collect data from respondents with the purpose of releasing it in the form of statistical summaries. The more detailed the summary is, the more likely a data intruder will be able to extract confidential data about individual respondents from the released data. However, there are various ways of redesigning the data product and/or modifying the data themselves to protect the data while preserving their usefulness. We discuss methods that achieve these two goals: (i) a data intruder will not be able to extract, with high confidence, confidential data directly from the data product or derive confidential microdata from several data products; and (ii) the released data are still quite detailed and useful to most data users, including researchers. Such “data‐masking” methods comprise a fast growing field often calledstatistical disclosure control.

We discuss some simpler methods that have been used for decades, such as detail reduction, cell suppression, and data swapping; some methods developed in the 1990s, such as rank swapping, data shuffling, and multiplicative noise; and some methods developed in recent decade, such as randomization of microdata with constraints (PRAM) and synthetic data.
Bayes Factors
Authors: Berger James , Pericchi Luis
Published: June 2015

Bayes factors are the primary tool used in Bayesian inference for hypothesis testing and model selection. They also are used by non‐Bayesians in the construction of test statistics. For instance, in the testing of simple hypotheses, the Bayes factor equals the ordinary likelihood ratio. Bayesian Model Selection discusses the use of Bayes factors in model selection. Statistical Evidence discusses the general use of Bayes factors in quantifying statistical evidence. We argue that: Science needs to abandon p‐values and adopt Bayes factors.
Kappa Coefficient
Authors: Kraemer Helena C.
Published: June 2015

Abstract

The population definitions of the intraclass kappa used for the assessment of agreement or reliability between two or more measurements of a single nonordered categorical measure and of the weighted kappa used for the assessment of correlation between two nonordered categorical measures, and their sample estimation are reviewed. Examples from the
DSM
‐5 field trials are used to illustrate the approaches.
Genetics and Genomics, Statistics in
Authors: Ewens Warren J.
Published: June 2015

Statistical concepts and methods, together with those of stochastic process theory, arise in at least four broad areas in genetics. First, standard statistical methods of estimation and hypothesis testing are used to estimate genetic parameters and test hypotheses about these parameters. Second, several central themes of plant and animal breeding theory and biological evolution are phrased in statistical terms and make substantial use of statistical techniques. Third, stochastic process theory is used to investigate properties of the evolution of a population subject to random changes in gene frequency. Finally, statistical methods are central to several currently active areas in genomics. Many statistical concepts, including in particular the Analysis of Variance, first arose in the context of genetics.
Collective Risk Models
Authors: Sheldon Lin X. , Willmot Gordon E.
Published: June 2015

This article reviews models for aggregate claims arising from an insurance portfolio when policy replacements are allowed. It presents various models and approaches to the evaluation of aggregate claims.
Ordering of Insurance Risk
Authors: Rüschendorf Ludger
Published: June 2015

Ordering of risks is a basic tool for analyzing risks and their premiums. It is an extension of the classical mean‐variance approach of Markovitz. We introduce some of the basic orderings as stochastic order and stop loss order and present some applications for the comparison of individual and collective risk models to the diversification of risks and to reinsurance contracts. In particular, we demonstrate the dramatic influence of positive dependence in a risk portfolio on the total risk. Obtaining sharp bounds on the influence of positive dependence in a portfolio on the total risk is an actual active research area.
Environmental Teratogenesis, Statistics for
Authors: Chen James J. , George E. Olusegun
Published: June 2015

Teratology is the study of adverse effects of environmental agents on the developing system. The major source of information for studying potential teratogenic (developmental) effects of chemicals on humans is generally the animal dose–response experiments. Quantitative risk assessment involves an assessment of the relationship between exposure and adverse health effects to derive an allowable exposure level. Acceptable levels of human exposure are derived by dividing the lower confidence limit benchmark dose by the product of several uncertainty factors. This article describes the statistical models and benchmark approach for quantitative risk assessment of developmental effects. The benchmark dose method involves selection of a dose–response function to fit animal experimental data. The benchmark dose and its lower confidence limit are then estimated from the fitted dose–response model. The dose–response function for continuous response data is modeled using the litter‐based analysis. The dose–response function for dichotomous response data is modeled using beta binomial.
Life Distributions, Simulation of
Authors: Zio Enrico
Published: June 2015

This article introduces the principles underlying the simulation of the probability distributions that typically characterize the life/failure processes of engineered components and systems. The basic procedures for sampling random numbers are reviewed and examples are provided with reference to the uniform, exponential, and Weibull distributions that are among the most commonly used probability distributions in reliability, availability, and safety analysis.
Random Number Generation and Quasi‐MonteCarlo
Authors: L'Ecuyer Pierre
Published: June 2015

Probability theory defines random variables and stochastic processes in terms of probability spaces, an abstract notion whose concrete and exact realization on a computer is far from obvious. (Pseudo)random number generators (RNGs) implemented on computers are actually deterministic programs that imitate, to some extent, independent random variables uniformly distributed over the interval (i.i.d. , for short). RNGs are a key ingredient for Monte Carlo simulations, probabilistic algorithms, computer games, cryptography, casino machines, and so on. In this article, we outline the main principles underlying the design and testing of RNGs for statistical computing and simulation. Then, we indicate how random numbers can be transformed to generate random variates from other distributions. Finally, we summarize the main ideas on quasi‐random points, which are more evenly distributed than independent random point and permit one to estimate integrals more accurately for the same number of function evaluations.
Numerical Algorithms
Authors: Horebeek Johan Van
Published: June 2015

We give an overview of several computer‐intensive numerical algorithms that have special relevance in applications with an intrinsic stochastic component.
Stochastic Simulation
Authors: Bølviken Erik
Published: June 2015

Stochastic simulation is reviewed with its main areas of application in insurance, finance, and economics and its principal techniques of implementation. An extensive list of references into many fields is provided.
Operations Research: Mathematical Methods
Authors: Bäuerle Nicole , Stein Oliver
Published: June 2015

In this section, we present the most important optimization problems arising in deterministic operations research and give a concise survey of common solution techniques. More precisely, we consider linear programming, combinatorial optimization, integer programming, nonlinear programming, and dynamic programming. Typical problems in these areas are also mentioned.
Credibility Theory
Authors: Norberg Ragnar
Published: June 2015

This survey of actuarial credibility theory traces its origins, describes its evolutionary history, gives an account of its main issues and results, and assesses its merits with a view to related work in statistical science.
Reinsurance – Terms, Conditions, and Methods of Placing
Authors: Czapiewski Colin
Published: June 2015

The placing of reinsurance business is changing, with the role of intermediaries and methods of placement being constantly assessed in light of the costs. Smaller lines with many reinsurers are being replaced by much larger lines with few reinsurers. New forms of reinsurance are being introduced to reflect the requirements of the reinsured more accurately. In view of the more legal examination of contracts, the accuracy of the terms, conditions, exclusions, and other aspects of policy wording are now more important than ever before. The recent growth in the importance of modeling property catastrophes by independent firms has changed this field considerably.
Epidemic Models, Structured Population
Authors: O'Neill Philip D. , Neal Peter J.
Published: June 2015

Real‐life epidemics invariably occur within populations composed of individuals who do not mix with each other entirely at random. Instead, there is frequently a nonhomogeneous mixing structure, so that individuals are more likely to spend time with those they live or work with, or who are geographically close, for example. In this article, we review a number of stochastic epidemic models, which attempt to incorporate population structure, providing descriptions of the models and highlighting associated results of interest. Aspects of related statistical inference are also considered. Such models offer a more realistic alternative to those that assume homogeneous mixing of either the entire population or large subpopulations.
Correspondence Analysis of Longitudinal Data
Authors: de Rooij Mark , van der Heijden P. G. M.
Published: June 2015

Correspondence analysis is an exploratory tool for the analysis of associations between categorical variables, the results of which may be displayed graphically. For longitudinal data, two types of analysis can be distinguished: the first focuses on transitions, whereas the second investigates trends. For transitional analysis with two time points, an analysis of the transition matrix (showing the relative frequencies for pairs of categories) provides insight into the structure of departures from independence in the transitions. Transitions between more than two time points can also be studied simultaneously. In trend analyses often the trajectories of different groups are compared. Examples for all these analyses are provided.
Complementary Medicines
Authors: Gueguen Juliette , Hill Catherine , Barry Caroline
Published: June 2015

Complementary medicine comprises many different disciplines and some, for instance, acupuncture, chiropractic, herbal medicine, and homoeopathy, are widely used. Patients with chronic pain show particular high rates of use. Efficacy and safety evaluations are warranted to sort out helpful interventions from unsafe practices. Thousands of randomized trials have evaluated the efficacy of the most popular complementary medicines but there is less information on their safety. However, important methodological problems in design and conduct, disagreement on the practice, variability of comparisons, and discordant interpretation of the trial results of studies have precluded reaching solid consensual conclusions. The challenge is to design studies in a way that fully satisfies methodological standards and that is consistent with everyday practice of complementary medicines including individualization of treatment and holistic aspects. The specific methodological problems of trials evaluating complementary medicines are discussed, with an emphasis on the necessity to use the full spectrum of trial designs, from very explanatory to completely pragmatic, in order to achieve a complete evaluation.
Second‐Order Factor Analysis: Confirmatory
Authors: Tisak John , Tisak Marie S.
Published: June 2015

Confirmatory second‐order factor analysis could be conceptualized as a further factor analysis of the results of an initial factor analysis of some observed variables. Specifically, the initial or first‐order factor means, variances, and covariances are re‐analyzed into more general or abstracted variables. For pedagogical reasons, this approach is initially developed via first‐ and second‐order multivariate multiple regression analyses using measured or observed variables. Next by analogy, the approach is extended to latent variates or unobserved factors. Throughout this article, an illustration is presented using Thurstone's Primary Mental Abilities, Horn and Cattell's Fluid and Crystallized Intelligences, and Spearmen's General Intelligence. Lastly, this second‐order factor analysis was extended to multiple populations.
Mathematical Psychology
Authors: Chechile Richard A.
Published: June 2015

Mathematical psychology is a branch of theoretical psychology that uses mathematics as a tool for psychological measurement of latent processes as a means to characterize the regular behavioral patterns that emerge from experimental studies. An example of the measurement of latent processes is a research that decomposes memory loss into separate components owing to storage and retrieval changes. Other models in mathematical psychology provide a detailed description of the results from many memory experiments. Mathematical psychologists have addressed a wide range of psychological problems and have utilized a diverse set of mathematical tools.
Clinical Trial Misconduct
Authors: Rennie Drummond , Murphy Constance
Published: June 2015

This article reviews the history and impact of research misconduct. It outlines some of the early cases that prompted standards and legislation. Finally, it discusses recent research abuses within and outside the United States.
Resampling Methods
Authors: Tu Wanzhu , Li Shanshan
Published: June 2015

This article presents an overview of existing resampling methods and their applications in parameter estimation and statistical inference. It describes the essential concepts and basic operating procedures of the most frequently used resampling methods, including the jackknife, bootstrap, permutation test, and cross‐validation. This article also discusses the interconnections among these methods. Finally, it briefly reviews the currently available software for implementation of the commonly used resampling procedures.
Zero‐Inflated Count Time Series
Authors: Charlton Sarah
Published: June 2015

Count data sometimes have an overabundance of zeros. A common choice to model these types of data is the zero‐inflated model, which is a mixture of a standard discrete count distribution and a degenerate distribution at zero. The model parameters can be estimated with an expectation–maximization algorithm. This article describes how to extend these models to incorporate time dependence in both the count and the zero‐inflation components of the zero‐inflated model via an observation‐driven approach. A series of daily counts of excess pollution levels observed at an air monitoring station near Houston, TX, is used to illustrate the ideas. Multivariate zero‐inflation models are also discussed.
On‐the‐Night Prediction of the Scottish Independence Referendum 2014
Authors: Fisher Stephen D.
Published: June 2015

This article discusses the methodology and experience of predicting the outcome of the September 2014 Scottish Independence Referendum from the flow of district‐level results for the
BBC
.
Advanced Concentration Gradient Cathode Material with Two‐Slope for High‐Energy and Safe Lithium Batteries
Authors: Lim Byung‐Beom , Yoon Sung‐Jun , Park Kang‐Joon , Yoon Chong S. , Kim Sung‐Jin , Lee Juhyon J. , Sun Yang‐Kook
Published: June 2015

Li[Ni0.65Co0.13Mn0.22]O2 cathode with two‐sloped full concentration gradient (TSFCG), maximizing the Ni content in the inner part of the particle and the Mn content near the particle surface, is synthesized via a specially designed batch‐type reactor. The cathode delivers a discharge capacity of 200 mAh g−1 (4.3 V cutoff) with excellent capacity retention of 88% after 1500 cycles in a full‐cell configuration. Overall electrochemical performance of the TSFCG cathode is benchmarked against conventional cathode (CC) with same composition and commercially available Li[Ni0.8Co0.15Al0.05]O2 (NCA). The TSFCG cathode exhibits the best cycling stability, rate capability, and thermal stability of the three electrodes. Transmission electron microscopy analysis of the cycled TSFCG, CC, and NCA cathodes shows that the TSFCG electrode maintains both its mechanical and structural integrity whereas the NCA electrode nearly pulverizes due to the strain during cycling.
16.1% Efficient Hysteresis‐Free Mesostructured Perovskite Solar Cells Based on Synergistically Improved ZnO Nanorod Arrays
Authors: Mahmood Khalid , Swain Bhabani Sankar , Amassian Aram
Published: June 2015

Significant efficiency improvements are reported in mesoscopic perovskite solar cells based on the development of a low‐temperature solution‐processed ZnO nanorod (NR) array exhibiting higher NR aspect ratio, enhanced electron density, and substantially reduced work function than conventional ZnO NRs. These features synergistically result in hysteresis‐free, scan‐independent, and stabilized devices with an efficiency of 16.1%. Electron‐rich, nitrogen‐doped ZnO (N:ZnO) NR‐based electron transporting materials (ETMs) with enhanced electron mobility produced using ammonium acetate show consistently higher efficiencies by one to three power points than undoped ZnO NRs. Additionally, the preferential electrostatic interaction between the ­nonpolar facets of N:ZnO and the conjugated polyelectrolyte polyethylenimine (PEI) has been relied on to promote the hydrothermal growth of high aspect ratio NR arrays and substantially improve the infiltration of the perovskite light absorber into the ETM. Using the same interactions, a conformal PEI coating on the electron‐rich high aspect ratio N:ZnO NR arrays is ­successfully applied, resulting in a favorable work function shift and altogether leading to the significant boost in efficiency from <10% up to >16%. These results largely surpass the state‐of‐the‐art PCE of ZnO‐based perovskite solar cells and highlight the benefits of synergistically combining mesoscale control with doping and surface modification.
Gaucher disease types 1 and 3: Phenotypic characterization of large populations from the ICGG Gaucher Registry
Authors: Grabowski Gregory A. , Zimran Ari , Ida Hiroyuki
Published: June 2015

Study of the natural history of Gaucher disease has revealed marked phenotypic variation. Correlations to genotypes could provide insight into individual susceptibility to varying disease severity, which may impact whole‐life medical care, reproductive decisions, and therapeutic choices for affected families. Importantly, pre‐symptomatic or prospective interventions or the use of therapies with significant risk require accurate risk‐benefit analyses based on the prognosis for individual patients. The body of international data held within the International Collaborative Gaucher Group (ICGG) Gaucher Registry provides an unprecedented opportunity to characterize the phenotypes of Gaucher disease types 1 and 3 and to appreciate demographic and ethnic factors that may influence phenotypes. The diversity of GBA gene mutations from patients with Gaucher disease represented in the ICGG Gaucher Registry database and in the literature provides the basis for initial genotype/phenotype correlations, the outcomes of which are summarized here.Am. J. Hematol. 90:S12–S18, 2015. © 2015 Wiley Periodicals, Inc.
Reversible cerebral vasoconstriction syndrome and posterior reversible encephalopathy syndrome in a boy with Loeys‐Dietz syndrome
Authors: Akazawa Yohei , Inaba Yuji , Hachiya Akira , Motoki Noriko , Matsuzaki Satoshi , Minatoya Kenji , Morisaki Takayuki , Morisaki Hiroko , Kosaki Kenjiro , Kosho Tomoki , Koike Kenichi
Published: June 2015

Loeys‐Dietz syndrome (LDS) is an autosomal dominant connective tissue disorder, caused by heterozygous mutations in TGFBR1 or TGFBR2 and characterized by vascular complications (cerebral, thoracic, and abdominal arterial aneurysms and/or dissections) and skeletal manifestations. We here report the first patient with LDS presenting with reversible cerebral vasoconstriction syndrome (RCVS), a clinico‐radiological condition characterized by recurrent thunderclap headaches, with or without neurological symptoms, and reversible vasoconstriction of cerebral arteries. The patient was a 9‐year‐old boy with a heterozygous TGFBR2 mutation, manifesting camptodactyly, talipes equinovarus, and lamboid craniosynostosis. He complained of severe recurrent headaches 2 months after total aortic replacement for aortic root dilatation and a massive Stanford type B aortic dissection. A thoracic CT scan revealed a left subclavian artery dissection. Brain MRI and MRA detected bilateral internal carotid artery constriction along with a cortical subarachnoid hemorrhage without intracranial aneurysms. Subsequently, he developed visual disturbance and a generalized seizure associated with multiple legions of cortical and subcortical increased signals including the left posterior lobe, consistent with posterior reversible encephalopathy syndrome (PRES), a condition characterized by headaches, visual disorders, seizures, altered mentation, consciousness disturbances, focal neurological signs, and vasogenic edema predominantly in the white matter of the posterior lobe. Vasoconstriction of the internal carotid artery was undetectable 2 months later, and he was diagnosed as having RCVS. Endothelial dysfunction, associated with impaired TGF‐β signaling, might have been attributable to the development of RCVS and PRES. © 2015 Wiley Periodicals, Inc.
Phenomenology of the Pyramid Scheme
Authors: Banks Tom
Published: June 2015

We review the Pyramid Scheme, the only class of models known to be consistent with phenomenology, coupling unification, and the Cosmological SUSY Breaking (CSB) relation between the gravitino mass and the cosmological constant (c.c.). These models are Terascale effective field theories, which have a super‐Poincare invariant, discrete R symmetric limit. R breaking terms come from diagrams in which a gravitino is exchanged with the horizon, and satisfy peculiar selection rules, which solve the μ problem, the strong CP problem, and the problem of low dimension operators in the theory, which violate B and L. The model predicts large Dirac and Majorana masses for gauginos, which make these states heavier than corresponding squarks and sleptons by a factor of roughly . Gluinos are too heavy to be seen at the 14 TeV LHC, and the NLSP is a right handed slepton (the three sleptons are quite degenerate), which decays promptly into a gravitino and a lepton.

image
Shape‐Persistent, Sterically Crowded Star Mesogens: From Exceptional Columnar Dimer Stacks to Supermesogens
Authors: Lehmann Matthias , Maier Philipp
Published: June 2015

Hexasubstituted C3‐symmetric benzenes with three oligophenylenevinylene (OPV) arms and three pyridyl or phenyl substituents are shape‐persistent star mesogens that are sterically crowded in the center. Such molecular structures possess large void spaces between their arms, which have to be filled in condensed phases. For the neat materials, this is accomplished by an exceptional formation of dimers and short‐range helical packing in columnar mesophases. The mesophase is thermodynamically stable for the pyridyl compound. Only this derivative forms filled star‐shaped supermesogens in the presence of various carboxylic acids. The latter do not arrange as dimers, but as monomers along the columnar stacks. In this liquid crystal (LC) phase, the guests are completely enclosed by the hosts. Therefore, the host can be regarded as a new LC endoreceptor, which allows the design of columnar functional structures in the future.
Poly(ethylene glycol) methyl ether methacrylate‐graft‐chitosan nanoparticles as a biobased nanofiller for a poly(lactic acid) blend: Radiation‐induced grafting and performance studies
Authors: Kongkaoroptham Parichart , Piroonpan Thananchai , Hemvichian Kasinee , Suwanmala Phiriyatorn , Rattanasakulthong Watcharee , Pasanphan Wanvimol
Published: June 2015

In this study, we aimed to modify chitosan (CS) as a novel compatible bio‐based nanofiller for improving the compatibility including the thermal and mechanical properties of poly(lactic acid) (PLA). The modification of CS with poly(ethylene glycol) methyl ether methacrylate (PEGMA) was done by radiation‐induced graft copolymerization. The effects of the dose rate, irradiation dose, and PEGMA concentration on the degree of grating (DG) were investigated. The chemical structure, packing structure, thermal stability, particle morphology, and size of the PEGMA‐graft‐chitosan nanoparticles (PEGMA‐graft‐CSNPs) were characterized by fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, and transmission electron microscopy. The compatibility of the PEGMA‐graft‐CSNP/PLA blends was also assessed by field emission scanning electron microscopy. The PEGMA‐graft‐CSNPs exhibited a spherical shape with the DG and particle sizes in the ranges of 3–145% and 35–104 nm, respectively. The PEGMA‐graft‐CSNPs showed compatible with PLA because of the grafted PEGMA segment. A model case study of the PEGMA‐graft‐CSNP/PLA blend demonstrated the improvement not only the compatibility but also thermal stability flexibility, and ductility of PLA. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42522.
Solution blown sulfonated poly(ether sulfone)/poly(ether sulfone) nanofiber‐Nafion composite membranes for proton exchange membrane fuel cells
Authors: Wang Hang , Zhuang Xupin , Li Xiaojie , Wang Wei , Wang Yannan , Cheng Bowen
Published: June 2015

A composite membrane of sulfonated poly(ether sulfone) (SPES)/poly(ether sulfone) (PES) nanofiber (NF) mat impregnated with Nafion was prepared and evaluated for its potential use as a proton conductor for proton exchange membrane (PEM) fuel cells. The supporting composite nanofibrous mat was prepared by solution blowing of a mixture of SPES/PES solution. The characteristics of the SPES/PES NF and the composite membrane, such as morphology, thermal stability, and performance of membrane as PEMs, were investigated. The performance of composite membranes was compared with that of Nafion117. The introduction of solution blown NFs to composite membranes modestly improved proton conductivity, water swelling, and methanol permeability. Therefore, composite membrane containing SPES/PES NFs can be considered as a novel PEM for fuel cell applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42572.
Social structure in a critically endangered Indo‐Pacific humpback dolphin (Sousa chinensis) population
Authors: Dungan Sarah Z. , Wang John Y. , Araújo Claryana C. , Yang Shih‐Chu , White Bradley N.
Published: June 2015

Social behaviour can be a vital aspect of population viability when it influences survivorship and reproductive fitness, which is often the case for especially social species, including cetaceans. Understanding this relationship is important in at‐risk populations, where knowledge of network structure can provide insight into how they may respond to human impacts.

Association patterns in the critically endangered eastern Taiwan Strait (ETS) population of Indo‐Pacific humpback dolphins, Sousa chinensis, were investigated using the seasonally collected (2007–2010) photo‐identification data of 74 individuals.

Social network structure was characterized by high strength and reach, features that are thought to be atypical for the species.

Standardized lagged association rates were best fitted by a two‐level model: short‐term associations that dissipated in less than a day, and long‐term associations projected to persist nearly 10 years. These persisting relationships were primarily among calves and their inferred mothers. The short‐term associations, which were probably limiting the network's modularity, seemed to occur among more weakly associated individuals temporarily participating in large mother–calf groups.

When associations were defined by proximity (within one body‐length), relationships involving calves were characterized by a significantly high clustering coefficient, and some calves had high associations with other calves and more than one adult, making maternal relationships ambiguous. This could be evidence for cooperative calf rearing, which may be important for calf survivorship and initiating dyadic relationships among calves.

Given their apparent uniqueness among populations of this species, the association patterns observed among the ETS S. chinensis, calves and their inferred mothers in particular, could be a response to conditions (small population size, isolation, confined distribution, and anthropogenic stressors) that make long‐term cooperative behaviour advantageous. Thus, minimizing human impacts that disrupt social dynamics, such as interactions with fisheries and habitat fragmentation, should help to improve this population's long‐term viability.

Copyright © 2015 John Wiley & Sons, Ltd.
Sol‐gel synthesis and luminescent properties of red‐emitting Y(P,V)O4:Eu3+ phosphors
Authors: Zhang Xinguo , Zhou Fangxiang , He Pei , Zhang Min , Gong Menglian
Published: June 2015

Eu3+‐activated Y(P,V)O4 phosphors were prepared by the EDTA sol‐gel method, and the corresponding morphologies and luminescent properties were investigated. The sample particles were relatively spheroid with size of 2–3 µm and had a smooth surface. The excitation spectra for Y(P,V)O4:Eu3+ consisted of three strong excitation bands in the 200–350 nm range, which were attributed to a Eu3+‐ O2− charge‐transfer band and 1A1−1 T1/1 T2 transitions in VO43−. The as‐synthesized phosphors exhibited a highly efficient red luminescence at 613 nm due to the Eu3+ 5D0−7 F2 electric dipole transition. With the increase in the V5+/P5+ ratio, the luminescence intensity of the red phosphor under UV excitation was greatly improved due to enhanced VO43− → Eu3+ energy transfer. Copyright © 2015 John Wiley & Sons, Ltd.
Improving recombinant protein production in the Chlamydomonas reinhardtii chloroplast using vivid Verde Fluorescent Protein as a reporter
Authors: Braun‐Galleani Stephanie , Baganz Frank , Purton Saul
Published: June 2015

Microalgae have potential as platforms for the synthesis of high‐value recombinant proteins due to their many beneficial attributes including ease of cultivation, lack of pathogenic agents, and low‐cost downstream processing. However, current recombinant protein levels are low compared to other microbial platforms and stable insertion of transgenes is available in only a few microalgal species. We have explored different strategies aimed at increasing growth rate and recombinant protein production in the Chlamydomonas reinhardtii chloroplast. A novel fluorescent protein (vivid Verde Fluorescent Protein, VFP) was expressed under the control of the native atpA promoter/5'UTR element. VFP levels were detected by western blotting, with increased protein levels observed when co‐expressed with a gene encoding the Escherichia coli Spy chaperone. We used these transformant lines to study the effect of temperature, light and media on recombinant protein production and cell growth. VFP levels and fluorescence, assessed by flow cytometry, allowed a determination of improved cultivation conditions as 30°C under mixotrophic mode. These conditions were tested for the accumulation of an antimicrobial endolysin (Cpl‐1) of potential commercial interest, observing that the outcome obtained for VFP could not be easily replicated for Cpl‐1. This study suggests that recombinant protein expression is product‐specific and needs to be optimized individually.
Donor characteristics and risk of hepatocellular carcinoma recurrence after liver transplantation
Authors: Orci L A , Berney T , Majno P E , Lacotte S , Oldani G , Morel P , Mentha G , Toso C
Published: June 2015

Background

To date, studies assessing the risk of post-transplant hepatocellular carcinoma (HCC) recurrence have focused on tumour characteristics. This study investigated the impact of donor characteristics and graft quality on post-transplant HCC recurrence.

Methods

Using the Scientific Registry of Transplant Recipients patients with HCC who received a liver transplant between 2004 and 2011 were included, and post-transplant HCC recurrence was assessed. A multivariable competing risk regression model was fitted, adjusting for confounders such as recipient sex, age, tumour volume, α-fetoprotein, time on the waiting list and transplant centre.

Results

A total of 9724 liver transplant recipients were included. Patients receiving a graft procured from a donor older than 60 years (adjusted hazard ratio (HR) 1·38, 95 per cent c.i. 1·10 to 1·73; P = 0·006), a donor with a history of diabetes (adjusted HR 1·43, 1·11 to 1·83; P = 0·006) and a donor with a body mass index of 35 kg/m2 or more (adjusted HR 1·36, 1·04 to 1·77; P = 0·023) had an increased rate of post-transplant HCC recurrence. In 3007 patients with documented steatosis, severe graft steatosis (more than 60 per cent) was also linked to an increased risk of recurrence (adjusted HR 1·65, 1·03 to 2·64; P = 0·037). Recipients of organs from donation after cardiac death donors with prolonged warm ischaemia had higher recurrence rates (adjusted HR 4·26, 1·20 to 15·1; P = 0·025).

Conclusion

Donor-related factors such as donor age, body mass index, diabetes and steatosis are associated with an increased rate of HCC recurrence after liver transplantation.
MATLAB and FPGA‐based interactive tool for exploring concepts on compressed sensing
Authors: Rico‐Aniles Daniel , Ramirez‐Cortes Juan Manuel , Rangel‐Magdaleno Jose , Gomez‐Gil Pilar , Peregrina‐Barreto Hayde , Alarcon‐Aquino Vicente
Published: June 2015

This paper presents an educational platform developed to explore some concepts related to the relatively new signal acquisition paradigm known as Compressed Sensing (CS). CS aims to acquire a signal with sparse or compressible representation in a suitable domain, using a number of samples under the limit established by the Nyquist–Shannon sampling theorem. The application consists of a graphical user interface in MATLAB, and a low‐cost FPGA Xilinx Spartan 6, which in that way form a powerful and low‐cost design station adequate to perform a number of CS experiments. Reconstruction of signals is carried out using a Greedy algorithm which solves the underdetermined system in real time with a novel Chebyshev‐type matrix inversion. Effects related to the number of samples defined in the measurement matrix, and the use of different spaces, such as Discrete Cosine Transform, or Discrete Wavelet Transform, can be easily studied with the described tool. Results derived from its use in graduate courses are discussed. © 2015 Wiley Periodicals, Inc. Comput Appl Eng Educ 23:921–930, 2015; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21664
Predictive validity of the HCR‐20 for violent and non‐violent sexual behaviour in a secure mental health service
Authors: O'Shea Laura E. , Thaker Dev‐Kishan , Picchioni Marco M. , Mason Fiona L. , Knight Caroline , Dickens Geoffrey L.
Published: June 2015

Background

Violent and non‐violent sexual behaviour is a fairly common problem among secure mental health service patients, but specialist sexual violence risk assessment is time‐consuming and so performed infrequently.

Aims

We aimed to establish whether a commonly used violence risk assessment tool, the Health Clinical Risk management 20(HCR‐20), has predictive validity specifically for inappropriate sexual behaviour.

Methods

A pseudo‐prospective cohort design was used for a study in the adult wards of a large provider of specialist secure mental health services. Routine clinical team HCR‐20 assessments were extracted from records, and incidents involving inappropriate sexual behaviour were recorded for the 3 months following assessment.

Results

Of 613 patients, 104 (17%) had engaged in at least one inappropriate sexual behaviour; in 65 (10.6%), the sexual act was violent. HCR‐20 total score, clinical and risk management subscales, predicted violent and non‐violent sexual behaviour. The negative predictive value of the HCR‐20 for inappropriate sexual behaviour was over 90%.

Conclusions

Prediction of violent sexual behaviour may be regarded as well within the scope of the HCR‐20 as a structured professional judgement tool to aid violence risk prediction, but we found that it also predicts behaviours that may be of concern but fall below the violence threshold. High negative predictive values suggest that HCR‐20 scores may have some utility for screening out patients who do not require more specialist assessment for inappropriate sexual behaviour. Copyright © 2015 John Wiley & Sons, Ltd.
Trends in cervical intraepithelial neoplasia Grade 2+ after human papillomavirus vaccination: The devil is in the details
Authors: Brar Harinder , Covens Allan
Published: June 2015

Eight years since the introduction of the adolescent HPV vaccination programs, as the vaccinated cohort enters adulthood, the impact of these vaccination programs is now being assessed through surrogate markers such as the incidence of high‐grade cervical dysplasia (cytology/histology) and the incidence of genital warts. Early data from the HPV‐IMPACT study shows that although there has been a noticeable drop in CIN2+ incidence rates, the results may be confounded by the recent changes in cervical screening guidelines. This study is significant in that it is the first to report on changes in high‐grade histological abnormalities in the postvaccination era. Despite the confounding effect of changing cervical cancer screening guidelines, the findings cannot be completely ignored. With wider acceptance and standardization of cervical cancer screening guidelines and with an increasing number of women entering the vaccinated cohort, the magnitude of vaccine effectiveness should become more obvious. Further studies are needed to assess the changes in high‐grade histological abnormalities in the post‐vaccine era.
Are high drug prices for hematologic malignancies justified? A critical analysis
Authors: Chhatwal Jagpreet , Mathisen Michael , Kantarjian Hagop
Published: June 2015

In the past 15 years, treatment outcomes for hematologic malignancies have improved substantially. However, drug prices have also increased drastically. This commentary examines the value of the treatment of hematologic malignancies at current prices in the United States through a reanalysis of a systematic review evaluating 29 studies of 9 treatments for 4 hematologic malignancies. Incremental cost‐effectiveness ratios (ICERs) were calculated on the basis of drug prices in the United States in 2014. Sixty‐three percent of the studies (15 of 24) had ICERs higher than $50,000 per quality‐adjusted life‐year (QALY), the benchmark widely used by health economists to define cost‐effectiveness. In studies evaluating the current standard‐of‐care treatments for chronic myeloid leukemia, the ICERs for tyrosine kinase inhibitors versus hydroxyurea or interferon ranged from $210,000 to $426,000/QALY. The lower ICER values were mostly obtained from 11 studies evaluating rituximab, which was approved by the Food and Drug Administration in 1997 (ICER range, $37,000‐$69,000/QALY). In conclusion, the costs of the majority of new treatments for hematologic cancers are too high to be deemed cost‐effective in the United States. Cancer 2015;121:3435–43. © 2015 American Cancer Society.
Formation and Fragmentation of Protonated Molecules after Ionization of Amino Acid and Lactic Acid Clusters by Collision with Ions in the Gas Phase
Authors: Poully Jean‐Christophe , Vizcaino Violaine , Schwob Lucas , Delaunay Rudy , Kocisek Jaroslav , Eden Samuel , Chesnel Jean‐Yves , Méry Alain , Rangama Jimmy , Adoui Lamri , Huber Bernd
Published: June 2015

Collisions between O3+ ions and neutral clusters of amino acids (alanine, valine and glycine) as well as lactic acid are performed in the gas phase, in order to investigate the effect of ionizing radiation on these biologically relevant molecular systems. All monomers and dimers are found to be predominantly protonated, and ab initio quantum–chemical calculations on model systems indicate that for amino acids, this is due to proton transfer within the clusters after ionization. For lactic acid, which has a lower proton affinity than amino acids, a significant non‐negligible amount of the radical cation monomer is observed. New fragment‐ion channels observed from clusters, as opposed to isolated molecules, are assigned to the statistical dissociation of protonated molecules formed upon ionization of the clusters. These new dissociation channels exhibit strong delayed fragmentation on the microsecond time scale, especially after multiple ionization.