bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatiotemporal evolution of electron characteristics in the electron diffusion region of magnetic reconnection: Implications for acceleration and heating
Authors: Shuster J. R. , Chen L.‐J. , Hesse M. , Argall M. R. , Daughton W. , Torbert R. B. , Bessho N.
Published: March 2015

Based on particle‐in‐cell simulations of collisionless magnetic reconnection, the spatiotemporal evolution of electron velocity distributions in the electron diffusion region (EDR) is reported to illustrate how electrons are accelerated and heated. Approximately when the reconnection rate maximizes, electron distributions in the vicinity of the X line exhibit triangular structures with discrete striations and a temperature (Te) twice that of the inflow region. Te increases as the meandering EDR populations mix with inflowing electrons. As the distance from the X line increases within the electron outflow jet, the discrete populations swirl into arcs and gyrotropize by the end of the jet with Te about 3 times that of the X line. Two dominant processes increase Te and produce the spatially and temporally evolving EDR distributions: (1) electric field acceleration preferential to electrons which meander in the EDR for longer times and (2) cyclotron turning by the magnetic field normal to the reconnection layer.
The global structure and time evolution of dayside magnetopause surface eigenmodes
Authors: Hartinger M. D. , Plaschke F. , Archer M. O. , Welling D. T. , Moldwin M. B. , Ridley A.
Published: March 2015

Theoretical work and recent observations suggest that the dayside magnetopause may support its own eigenmode, consisting of propagating surface waves which reflect at the northern and southern ionospheres. These magnetopause surface eigenmodes (MSEs) are a potential source of magnetospheric ultralow‐frequency (ULF) waves with frequencies less than 2 mHz. Here we use the Space Weather Modeling Framework to study the magnetospheric response to impulsive solar wind dynamic pressure increases. Waves with 1.8 mHz frequency are excited whose global properties are largely consistent with theoretical predictions for MSE and cannot be explained by other known ULF wave modes. These simulation results lead to two key findings: (1) MSE can be sustained in realistic magnetic field geometries with nonzero flow shear and finite current layer thickness at the magnetopause and (2) MSE can seed the growth of tailward propagating surface waves via the Kelvin‐Helmholtz instability.
Industry and Business, Statistics in
Authors: Snee Ronald D.
Published: March 2015

Statistics has been used in industry and business around the world since the mid‐twentieth century. This article discusses how statistics is used in industry including areas of application, statistical methods used, history of statistics in industry, careers for statisticians in industry, and the expanding role on statisticians in industry. References are provided to enable the reader to further explore the subject.
Latent‐Variable Modeling
Authors: Moustaki I. , Knott M. , Bartholomew D. J.
Published: March 2015

The article provides an overview of latent variable models including the classical factor analysis model, factor models for categorical manifest variables, structural equation models and more recent extensions for mixed (categorical and continuous) manifest and latent variables. Emphasis is given on model specification, estimation methods, goodness‐of‐fit test statistics, and factor scores.
Exponential Autoregressive Models
Authors: Billard L.
Published: March 2015

This article focuses on exponential autoregressive time series models. A key feature of these models is that the observations have marginal exponential distributions. The models are described, and estimation of the model parameters and prediction are discussed. A review of other related models is also included.
Bootstrap and Jackknife, Overview
Authors: Martin Michael A. , Roberts Steven
Published: March 2015

A quarter of a century ago, the advent of fast, cheap computing saw the emergence of computationally intensive methods that sought to exploit the data itself as a resource for information rather than relying on restrictive classical distributional assumptions that often failed to hold in practice. Methods such as the whimsically named jackknife and bootstrap have found wide use among practitioners in a variety of contexts. In this article, the basic uses of resampling techniques are described, with particular attention to bias and variance estimation and confidence interval construction. Implementation of these techniques in popular statistical software is also described.
Perfect Sampling
Authors: Connor Stephen B.
Published: March 2015

Perfect simulation algorithms provide a method for generating aperfectsample from the stationary distribution of an ergodic Markov chain. We introduce two such algorithms, coupling from the past (CFTP) and dominated CFTP (domCFTP), and demonstrate their use with some simple examples.
Quality Control, Computing in
Authors: Noguera John , Breslaw Jon
Published: March 2015

The article provides a brief survey of important advances in quality control tools that are available to practitioners using current statistical quality software tools. The tools discussed include the use of the noncentral distribution function for power and sample size, exact statistics for small sample nonparametric tests and contingency tables, confidence intervals in measurement systems analysis, dealing with nonnormality and autocorrelation in statistical process control, and the use of genetic algorithms in the design and analysis of experiments.
Six Sigma Method
Authors: Does Ronald J.M.M. , Mast Jeroen De
Published: March 2015

Six Sigma is built on principles and methods that have proven themselves over the twentieth century. It has incorporated the most effective approaches and integrated them into a full program. It offers a management structure for organizing continuous improvement of routine tasks, such as manufacturing, service delivery, accounting, nursing, sales, and other work that is done routinely. Further, it offers a method and tools for carrying out improvement projects effectively.
Asset Shares
Authors: Forfar David O.
Published: March 2015

The article looks at asset shares, a concept primarily used in the United Kingdom in respect of with‐profits business (either conventional or unitized) but applicable to any policy where the bonus distribution is at the discretion of the insurance company.
Disability Insurance
Authors: Pitacco Ermanno
Published: March 2015

We first describe types of disability insurance products, and common policy conditions. Then a probabilistic model for insurance covers providing disability annuities is defined, adopting a time‐discrete approach. The construction of actuarial values, premiums, and reserves follows. A more general actuarial framework is finally sketched, by adopting the multistate approach.
Surplus in Life and Pension Insurance
Authors: O'Brien Christopher David
Published: March 2015

Surplus in life insurance is a key issue for participating business: actuarial control over the emergence and distribution of surplus is a major subject in the management of life insurance companies. Although we, here, concentrate on surplus in the context of participating life business, surplus is also relevant in any kind of fund in which long‐term liabilities may be valued on the basis of assumptions about the future. For example, shareholders have needs and expectations of surplus in nonparticipating life business, with premium rates and payouts being determined with a view to rewarding shareholders, who have provided capital and run risks. In pensions business, there are similar issues concerning the sources, size, analysis, and uses of surplus.
Pooling in Insurance
Authors: Aase Knut K.
Published: March 2015

In this article, we explore how pooling of economic risks is dealt with in insurance and reinsurance. Consider an average individual. Instead of facing risks in isolation, the individual may sort out a larger group of people with similar risks, and together work out a scheme how to share these. This should be done so that everyone comes out better than, or at least as good as, standing alone. In the article, I try to explain, by several examples, how pooling works in insurance. Pension insurance is our first example, where we point out how how pooling takes place along several different dimensions. A major concept is the
mutuality principle
, which we relate to both pension insurance and the theory of syndicates. We present some examples outside the field of insurance, with the same basic features, that of pooling individual risks. The last aspect of pooling that we discuss is best explained in the framework of information economics. This we do in a section about adverse selection.
Effect Size Measures
Authors: Kirk Roger E.
Published: March 2015

A variety of measures of effect magnitude are described. Many of the measures can be classified as either measures of effect size (typically, standardized mean differences) or measures of strength of association. There also is a large group of statistics that do not fit into either category. Measures of effect magnitude are used for a variety of purposes: (i) to estimate the sample size required to achieve an acceptable power, (ii) to integrate the results of empirical research studies in meta‐analyses, (iii) to supplement the information provided by null‐hypothesis significance tests, and (iv) to determine whether research results are practically significant.
Trellis Graphics
Authors: Everitt Brian , Sarkar Deepayan
Published: March 2015

In trellis graphics one, two, or more variables are plotted and conditioned on different values or categories of a given variable (or variables). Component panels representing subsets of the data defined by levels of the conditioning variables are arranged in a single display in a manner that makes comparison easier. Many different types of plots lend themselves to this treatment, including scatterplots and three‐dimensional scatterplots. Trellis graphics help in understanding both the structure of the data and how well proposed models for the data actually fit.
Structural Equation Modeling: Software
Authors: Rigdon Edward E.
Published: March 2015

The first widely distributed special‐purpose software for estimating factor‐based structural equation models appeared almost 40 years ago. Today, researchers can choose from a variety of packages that differ markedly in terms of their intellectual heritage, interface, statistical sophistication, flexibility, integration with other statistical packages, and cost. Pioneers
LISREL
and
EQS
continue to offer their strengths. Mplus appears to be the package with the broadest set of out‐of‐the‐box ready capabilities, although a rapidly developing offering from Stata may pose future competition. Most recently, strong alternatives have appeared within the open‐source R environment, particularly including the increasingly sophisticated lavaan and the extremely flexible
OpenMx
. Despite numerous advances, there is still substantial room for improvement.
Adaptive Random Assignment
Authors: Berger Vance W. , Zhou YanYan , Martin Keshia‐Lee
Published: March 2015

The primary objective of a comparative trial is to provide a precise and valid treatment comparison. Another objective may be to minimize exposure to the inferior treatment, the identity of which may be revealed only during the course of the study. Unrestricted randomization is not generally used because it is susceptible to chronological bias, and this would interfere with the first objective, the valid treatment comparison. Yet, too many restrictions lead to a predictable allocation sequence, which can also compromise validity. It can be a challenge to find the right balance of restrictions on the randomization, and sometimes a covariate‐adaptive design is used. When the second objective is considered as well, the solution must necessarily be a response‐adaptive design that evolves depending on the responses of those enrolled.
Predictors of disability worsening in clinically isolated syndrome
Authors: Jokubaitis Vilija G. , Spelman Tim , Kalincik Tomas , Izquierdo Guillermo , Grand'Maison François , Duquette Pierre , Girard Marc , Lugaresi Alessandra , Grammond Pierre , Hupperts Raymond , Cabrera‐Gomez José , Oreja‐Guevara Celia , Boz Cavit , Giuliani Giorgio , Fernández‐Bolaños Ricardo , Iuliano Gerardo , Lechner‐Scott Jeannette , Verheul Freek , van Pesch Vincent , Petkovska‐Boskova Tatjana , Fiol Marcela , Moore Fraser , Cristiano Edgardo , Alroughani Raed , Bergamaschi Roberto , Barnett Michael , Slee Mark , Vella Norbert , Herbert Joseph , Shaw Cameron , Saladino Maria Laura , Amato Maria Pia , Liew Danny , Paolicelli Damiano , Butzkueven Helmut , Trojano Maria ,   the MSBasis Study Group
Published: March 2015

Objective

To assess demographic, clinical, magnetic resonance imaging, and treatment exposure predictors of time to 3 or 12‐month confirmed disability worsening in clinically isolated syndrome (CIS) and early multiple sclerosis (MS).

Methods

We utilized the MSBase Incident Study (MSBasis), a prospective cohort study of outcome after CIS. Predictors of time to first 3 and 12‐month confirmed expanded disability status scale worsening were analyzed using Cox proportional hazards regression.

Results

About 1989 patients were analyzed, the largest seen‐from‐onset cohort reported to‐date. A total of 391 patients had a first 3‐month confirmed disability worsening event, of which 307 were sustained for 12 months. Older age at CIS onset (adjusted hazard ratio: aHR 1.17, 95% 1.06, 1.30), pyramidal (aHR 1.45, 95% CI 1.13, 1.89) and ambulation (HR 1.60, 95% CI 1.09, 2.34) system dysfunction, annualized relapse rate (aHR 1.20, 95% CI 1.18, 1.22), and lower proportion of observation time on treatment were associated with 3‐month confirmed worsening. Predictors of time to 12‐month sustained worsening included pyramidal system dysfunction (Hazard ratio: aHR 1.38, 95% CI 1.05, 1.83), and older age at CIS onset (aHR 1.17, 95% CI 1.04, 1.31). Greater proportion of follow‐up time exposed to treatment was associated with greater reductions in the rate of worsening.

Interpretation

This study provides class IV evidence for a strong protective effect of disease‐modifying treatment to reduce disability worsening events in patients with CIS and early MS, and confirms age and pyramidal dysfunction at onset as risk factors.
A case study of brain morphometry in triplets discordant for Down syndrome
Authors: Adeyemi Elizabeth I. , Giedd Jay N. , Lee Nancy Raitano
Published: March 2015

Down syndrome, the most common genetic cause of intellectual disability, offers the opportunity to explore the associations between genetics and both neuroanatomic and neuropsychological phenotypes. This case report summarizes the findings of a neuroimaging and neuropsychology study of two adolescent females with Down syndrome and their same‐sex discordant triplet siblings (one from each family; n = 4). Using high‐resolution magnetic resonance imaging and surface based morphometric approaches, we offer the first in vivo report of cortical surface area reductions and increases in the thickness of the cortical sheet in youth with Down syndrome relative to their typically developing same‐sex triplet siblings. © 2015 Wiley Periodicals, Inc.
Facing up to the challenges of advancing Craniofacial Research
Authors: Trainor Paul A. , Richtsmeier Joan T.
Published: March 2015

Craniofacial anomalies are among the most common human birth defects and have considerable functional, aesthetic, and social consequences. The early developmental origin as well as the anatomical complexity of the head and face render these tissues prone to genetic and environmental insult. The establishment of craniofacial clinics offering comprehensive care for craniofacial patients at a single site together with international research networks focused on the origins and treatment of craniofacial disorders has led to tremendous advances in our understanding of the etiology and pathogenesis of congenital craniofacial anomalies. However, the genetic, environmental, and developmental sources of many craniofacial disorders remain unknown. To overcome this problem and further advance craniofacial research, we must recognize current challenges in the field and establish priority areas for study. We still need (i) a deeper understanding of variation during normal development and within the context of any disorder, (ii) improved genotyping and phenotyping and understanding of the impact of epigenetics, (iii) continued development of animal models and functional analyses of genes and variants, and (iv) integration of patient derived cells and tissues together with 3D printing and quantitative assessment of surgical outcomes for improved practice. Only with fundamental advances in each of these areas will we be able to meet the challenge of translating potential therapeutic and preventative approaches into clinical solutions and reduce the financial and emotional burden of craniofacial anomalies. © 2015 Wiley Periodicals, Inc.
Formal Synthesis of the Human Rhinovirus 3 C Protease Inhibitor (−)‐Thysanone
Authors: Mulay Sandip V. , Gholap Sachin P. , Fernandes Rodney A.
Published: March 2015

A strategy based on Dötz benzannulation and an oxa‐Pictet‐Spengler reaction toward the formal synthesis of a human rhinovirus (HRV) 3C protease inhibitor, the pyranonaphthoquinone (−)‐thysanone, is presented.
Preparation and properties of polymerizable 1,8‐naphthalimide fluorescent dye grafted linear low‐density polyethylene
Authors: Lin Zesen , Zhang Jianfu , Ma Haifeng , Yao Zhanhai
Published: March 2015

Light converting greenhouse films are novel plastic films for agriculture. In this study, 4‐methoxy‐N‐allyl‐1,8‐naphthalimide (MOANI) was grafted onto linear low‐density polyethylenes (LLDPE‐g‐MOANI) by melt reactive mixing. The effects of monomer concentration, chamber temperature, and reaction time on grafting degree were systematically studied. Evidence of the grafting reaction was determined by 1HNMR, FTIR, UV–Vis, and fluorescence spectrometry. Dynamic rheological properties, isothermal crystallization kinetics, surface morphologies of LLDPE, LLDPE‐g‐MOANI, and blends of LLDPE and MOANI (LLDPE/MOANI) were also analyzed. In addition, mechanical and fluorescent properties of unpurified LLDPE‐g‐MOANI films were further studied after the UV condensation weathering and acceleration migration test, respectively. We demonstrated that the cross‐linking of LLDPE could be inhibited effectively by the graft of MOANI; the grafted MOANI acted as a nucleation agent to accelerate crystallization; the grafted MOANI effectively inhibited the aging process of LLDPE and the migration of free MOANI to the surface of the unpurified LLDPE‐g‐MOANI film. The modified LLDPE showed the potential application in long‐term light converting films. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42172.
Polyhedral oligomeric silsesquioxane/silica/polydimethylsiloxane rubber composites with enhanced mechanical and thermal properties
Authors: Zhang Dian , Huang Guangsu , Shi Yunhui , Zhang Guangya , Liu Yufeng
Published: March 2015

Composites of polydimethylsiloxane (PDMS) rubber modified by three kinds of polyhedral oligomeric silsesquioxanes (POSSs) as well as fumed silica were prepared through solution blending and then open two‐roll mill blending with curing agent. Subsequently, the influences of POSS on mechanical and thermal properties of the resulting composites were investigated in detail. The addition of POSS significantly enhanced the tensile strength and elongation at break of the composite but lowered the tensile modulus, which could be ascribed to the interruption of silica–silica and silica–PDMS interactions. Octamethylsilsesquioxane (OMS)/silica/PDMS and octaphenylsilsesquioxane (OPS)/silica/PDMS composites did not show desirable mechanical and thermal properties. Nevertheless, heptaphenylvinylsilsesquioxane (VPS)/silica/PDMS composite with 5 wt % VPS exhibited enhanced glass transition temperature (Tg), mechanical properties, and thermal stability. Further studies revealed that more VPS unfavorably affected properties of the composite. Scanning electron microscope and X‐ray diffraction demonstrated that owing to the grafting reaction, 5 wt % VPS in the rubber matrix could form microcrystal domains the most effectively. Thus, the improved mechanical properties and thermal stability just resulted from the the formation of microcrystal domains and the increase in stiffness of PDMS chains because of the graft of VPS onto PDMS. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42173.
Architecture–process relationships in stochastic honeycombs
Authors: Hostetter Megan , Hibbard Glenn
Published: March 2015

Stochastic honeycomb sandwich panels are fabricated through a simple process of melt‐stretching molten polymer blanks. This study mapped their internal architecture over a wide domain of material process space, defined by the areal density and melt‐stretch rate. The internal architectures were characterized using both topological and geometric parameters: the node density, the total length of webs, the Euler number, and a characteristic fractal area fraction. The mechanical response of the polymer melt was quantified in terms of peak stress and stiffness, along with apparent elongation viscosity. The observed architectures and polymer melt responses were consistent with a varying activated entanglement density in the melt and illustrate how the fabrication conditions can be tuned to obtain a desired architecture. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42174.
Ability and Disability in Autism Spectrum Disorder: A Systematic Literature Review Employing the International Classification of Functioning, Disability and Health‐Children and Youth Version
Authors: de Schipper Elles , Lundequist Aiko , Coghill David , de Vries Petrus J. , Granlund Mats , Holtmann Martin , Jonsson Ulf , Karande Sunil , Robison John E. , Shulman Cory , Singhal Nidhi , Tonge Bruce , Wong Virginia C.N. , Zwaigenbaum Lonnie , Bölte Sven
Published: March 2015

Objective: This study is the first in a series of four empirical investigations to develop International Classification of Functioning, Disability and Health (ICF) Core Sets for Autism Spectrum Disorder (ASD). The objective was to use a systematic review approach to identify, number, and link functional ability and disability concepts used in the scientific ASD literature to the nomenclature of the ICF‐CY (Children and Youth version of the ICF, covering the life span). Methods: Systematic searches on outcome studies of ASD were carried out in Medline/PubMed, PsycINFO, ERIC and Cinahl, and relevant functional ability and disability concepts extracted from the included studies. These concepts were then linked to the ICF‐CY by two independent researchers using a standardized linking procedure. New concepts were extracted from the studies until saturation of identified ICF‐CY categories was reached. Results: Seventy‐one studies were included in the final analysis and 2475 meaningful concepts contained in these studies were linked to 146 ICF‐CY categories. Of these, 99 categories were considered most relevant to ASD (i.e., identified in at least 5% of the studies), of which 63 were related to Activities and Participation, 28 were related to Body functions, and 8 were related to Environmental factors. The five most frequently identified categories were basic interpersonal interactions (51%), emotional functions (49%), complex interpersonal interactions (48%), attention functions (44%), and mental functions of language (44%). Conclusion: The broad variety of ICF‐CY categories identified in this study reflects the heterogeneity of functional differences found in ASD—both with respect to disability and exceptionality—and underlines the potential value of the ICF‐CY as a framework to capture an individual's functioning in all dimensions of life. The current results in combination with three additional preparatory studies (expert survey, focus groups, and clinical study) will provide the scientific basis for defining the ICF Core Sets for ASD for multipurpose use in basic and applied research and every day clinical practice of ASD. Autism Res 2015, 8: 782–794. © 2015 The Authors Autism Research published by Wiley Periodicals, Inc. on behalf of International Society for Autism Research
Maternal occupational exposure to ionizing radiation and major structural birth defects
Authors: Lim Hyeyeun , Agopian A.J. , Whitehead Lawrence W. , Beasley Charles W. , Langlois Peter H. , Emery Robert J. , Waller Dorothy Kim ,   the National Birth Defects Prevention Study
Published: March 2015

Background

Ionizing radiation (IR) is known to be carcinogenic and mutagenic, but little is known about the association between maternal occupational exposure to IR and birth defects.

Methods

We studied 38,009 mothers who participated in the National Birth Defects Prevention Study and delivered between 1997 and 2009. We assessed odds ratios [ORs] for the association between maternal occupations with potential exposure to IR and 39 birth defects.

Results

We observed significant odds ratios (ORs) for isolated hydrocephaly (adjusted OR [AOR], 2.1; 95% confidence interval [CI], 1.1–4.2), isolated anotia/microtia (AOR, 2.0; 95% CI, 1.0–4.0), isolated colonic atresia (crude OR, 7.5; 95% CI, 2.5–22.3), isolated omphalocele (AOR, 2.3; 95% CI, 1.1–4.6) and isolated anencephaly (crude OR, 0.23; 95% CI, 0.06–0.94). We also observed a nonsignificant OR for birth defects in aggregate (AOR, 2.0; 95% CI, 0.9–4.6) among mothers with potential occupational exposure to fluoroscopy.

Conclusion

We assessed 39 birth defects, observing that maternal occupations with potential exposure to IR were associated with a significantly increased risk for 4 birth defects and a significantly protected risk for 1 birth defect. These results should be interpreted cautiously because our measurement of exposure is qualitative, some of these associations may be due to occupational exposures that are correlated with IR and some may be due to chance. However, these findings serve as the first evaluation of these relationships in a large study and may be useful for generating hypotheses for future studies. Birth Defects Research (Part A) 103:243–254, 2015. © 2015 Wiley Periodicals, Inc.
Advances in ultrasound imaging for congenital malformations during early gestation
Authors: Rayburn William F. , Jolley Jennifer A. , Simpson Lynn L.
Published: March 2015

BACKGROUND: With refinement in ultrasound technology, detection of fetal structural abnormalities has improved and there have been detailed reports of the natural history and expected outcomes for many anomalies. The ability to either reassure a high‐risk woman with normal intrauterine images or offer comprehensive counseling and offer options in cases of strongly suspected lethal or major malformations has shifted prenatal diagnoses to the earliest possible gestational age. METHODS: When indicated, scans in early gestation are valuable in accurate gestational dating. Stricter sonographic criteria for early nonviability guard against unnecessary intervention. Most birth defects are without known risk factors, and detection of certain malformations is possible in the late first trimester. RESULTS: The best time for a standard complete fetal and placental scan is 18 to 20 weeks. In addition, certain soft anatomic markers provide clues to chromosomal aneuploidy risk. Maternal obesity and multifetal pregnancies are now more common and further limit early gestation visibility. CONCLUSION: Other advanced imaging techniques during early gestation in select cases of suspected malformations include fetal echocardiography and magnetic resonance imaging. Birth Defects Research (Part A) 103:260–268, 2015. © 2015 Wiley Periodicals, Inc.
Are Corporate Carbon Management Practices Reducing Corporate Carbon Emissions?
Authors: Doda Baran , Gennaioli Caterina , Gouldson Andy , Grover David , Sullivan Rory
Published: March 2015

This paper is the first large scale, quantitative study of the impact of corporate carbon management practices on corporate greenhouse gas (GHG) emissions. Using data for 2009 and 2010 from the Carbon Disclosure Project survey, we find little compelling evidence that commonly adopted management practices are reducing emissions. This finding is unexpected and we propose three possible explanations for it. First, it may be because corporate carbon data and management practice information have not been reported in a standardized way. Second, there may be a delay between the application of corporate carbon management practices and their impact on emissions performance. Third, carbon management practices are not sufficiently impact‐oriented, meaning there is no relationship to observe. Our findings are important for policymakers designing corporate GHG reporting standards, for the multiple stakeholders trying to understand the drivers of corporate carbon performance, and for the corporate managers responsible for measuring, reporting and mitigating emissions. Copyright © 2015 The Authors. Corporate Social Responsibility and Environmental Management published by ERP Environment and John Wiley & Sons Ltd.
Hair cortisol concentrations in higher‐ and lower‐stress mother–daughter dyads: A pilot study of associations and moderators
Authors: Ouellette Sarah J. , Russell Evan , Kryski Katie R. , Sheikh Haroon I. , Singh Shiva M. , Koren Gideon , Hayden Elizabeth P.
Published: March 2015

Hair cortisol concentrations (HCC) are receiving increased attention as a novel biomarker of psychophysiological responses to chronic stress, with potential relevance for psychopathology risk research. We examined the validity of HCC as a marker of psychosocial stress in mother (Mage = 37.87 years)–daughter (Mage = 7.62 years) dyads characterized by higher (n = 30) or lower (n = 30) maternal chronic stress. Additionally, we examined whether early care moderated similarity of HCC levels within dyads. Higher‐stress mothers had significantly lower HCC compared to lower‐stress mothers, consistent with other research showing that chronic stress leads to blunted HPA axis activity over time. Further, HCC in daughters were significantly and positively associated with previously assessed salivary cortisol stress reactivity. Finally, mother–daughter HCC associations were significantly moderated by negative parenting styles, such that associations became stronger as quality of parenting decreased. Findings overall indicate that HCC may be a useful marker of cortisol responses to chronic stress. © 2015 Wiley Periodicals, Inc. Dev Psychobiol 57: 519–534, 2015.
Blood group AB is protective factor for gestational diabetes mellitus: a prospective population‐based study in Tianjin, China
Authors: Zhang Cuiping , Li Yi , Wang Leishen , Sun Shurong , Liu Gongshu , Leng Junhong , Guo Jia , Lv Li , Li Weidong , Zhang Cuilin , Hu Gang , Yu Zhijie , Yang Xilin
Published: March 2015

Background

The ABO blood types are associated with cancers, cardiovascular diseases and type 2 diabetes mellitus but whether they are also associated with gestational diabetes mellitus (GDM) is unknown. We examined the relationship between the ABO blood types and the risk of GDM in a prospective population‐based Chinese cohort.

Methods

From 2010 to 2012, we recruited 14 198 pregnant women within the first 12 weeks of gestation in Tianjin, China. All women had a glucose challenge test (GCT) at 24–28 gestational weeks, followed by a 75‐g 2‐h oral glucose tolerance test if the results from GCT were ≥7.8 mmol/L. GDM was diagnosed based on the glucose cut‐points of the International Association of Diabetes and Pregnancy Study Group criteria. Logistic regression was used to obtain odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for traditional risk factors. Stratified analysis was performed by family history of diabetes (yes versus no). Sensitivity analyses were also performed by using the World Health Organization (WHO) criteria for GDM.

Results

Women with blood groups A, B or O (i.e. non‐AB) were associated with increased risk of GDM as compared with those with blood group AB (adjusted OR: 1.44, 95% CI: 1.13–1.83). Sensitivity analyses showed that the result was consistent using WHO criteria. The adjusted OR of blood group non‐AB versus AB for GDM was enhanced among women with a family history of diabetes (2.69, 1.21–5.96) and attenuated among those without (1.33, 1.03–1.71).

Conclusions

Blood group AB was a protective factor against GDM in pregnant Chinese women. Copyright © 2015 John Wiley & Sons, Ltd.
The gene encoding the mouse contactin‐1 axonal glycoprotein is regulated by the collier/Olf1/EBF family early B‐Cell factor 2 transcription factor
Authors: Bizzoca Antonella , Picocci Sabrina , Corsi Patrizia , Arbia Stefania , Croci Laura , Consalez G. Giacomo , Gennarini Gianfranco
Published: March 2015

The Contactin‐1 axonal glycoprotein (formerly F3/Contactin) plays a relevant role in cerebellar ontogenesis, as shown in Contactin‐1 KO‐mice and in transgenic mice misexpressing the corresponding cDNA from a heterologous promoter. Likewise, null mutant mice for the Collier/Olf1/Early B‐cell family transcription factor EBF2, in which Purkinje neuron development is primarily affected, exhibit abnormalities in cerebellar corticogenesis. Here, to evaluate the contribution to the Ebf2 null phenotype of changes in the profile of Contactin‐1, we study its expression in Ebf2 null mice. In addition, we explore the activation profile of the Cntn1 gene promoter upon transferring the Ebf2 mutation to transgenic mice expressing an enhanced green fluorescent protein reporter under control of Cntn1 gene regulatory sequences. In Ebf2 null mice, Contactin‐1 protein expression and Cntn1 gene promoter activity are both downregulated during embryonic and early postnatal cerebellar development, both in the rostral and caudal folia, while in the latter an upregulation is observed at postnatal day 8. In vitro, vectors driving EBF1,2,3 transcription factors from a cytomegalovirus (CMV) promoter transactivate a Cntn1‐Choline acetyltransferse (CAT) promoter‐reporter construct in cotransfection assays and, accordingly, by chromatin immunoprecipitation, we show that the Cntn1 gene 5′ flanking region is bound by the EBF2 transcription factor, consistent with the evidence that this region bears the cognate deoxyribonucleic acid (DNA) consensus sequences. These data indicate that Contactin‐1 expression is dependent upon EBF factors, suggesting that the Cntn1 gene belongs to the expanding regulatory cascade driven by these transcriptional regulators so that changes in its activation may contribute to the phenotype of Ebf2 null mutant mice. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 75: 1420–1440, 2015
Metabolomics analysis of muscle from piglets fed low protein diets supplemented with branched chain amino acids using HPLC‐high‐resolution MS
Authors: Wang Xian , Wei Hongkui , Cao Jingjing , Li Zhen , He Pingli
Published: March 2015

Low protein (LP) diet can reduce feed costs and decrease nitrogen emission. Branched chain amino acids (BCAA), especially leucine, have been shown to influence muscle protein metabolism. Here, we used HPLC‐high‐resolution MS‐based metabolomics approach to investigate the effects of LP diet supplemented with BCAA on metabolome in the muscle of piglets. The 10–21 kg piglets were fed with LP diet supplemented with BCAA. Amino acids (AAs) and metabolomics profiles of plasma, muscle, and liver were analyzed. Free AA profiles of plasma showed increased levels of BCAA. Multivariate analysis showed significant difference in skeletal muscle metabolites among different diet treatment groups, and most of the identified differential compounds were involved in AA metabolism and protein anabolism. These compounds, including alanine, glutamine, sarcosine, ornithine, proline, methionine, and threonine, all increased in the BCAA supplemented group compared with normal protein diet group. Metabolic pathway analysis suggested that BCAA could be converted to nonessential AAs and their metabolites by direct or indirect synthesis under LP diets, which could participate in the muscle protein synthesis or energy metabolism, and ultimately reduced nitrogen emission.
Combination of CE‐MS and advanced chemometric methods for high‐throughput metabolic profiling
Authors: Ortiz‐Villanueva Elena , Jaumot Joaquim , Benavente Fernando , Piña Benjamín , Sanz‐Nebot Victoria , Tauler Romà
Published: March 2015

In this work, an untargeted approach based on capillary electrophoresis‐mass spectrometry (CE‐MS) in combination with multivariate data analyses is proposed as a high‐throughput general methodology for metabolomic studies. First, total ion electropherograms (TIEs) were considered for exploratory and classification purposes by means of principal component analysis (PCA) and partial least squares discriminant analysis (PLS‐DA). Then, multivariate curve resolution alternating least squares (MCR‐ALS) was applied to the multiple full scan MS data sets. This strategy permitted the resolution of a large number of metabolites being characterized by their electrophoretic peaks and their corresponding mass spectra. The proposed approach allowed solving additional electrophoretic issues, such as background noise contributions, low signal‐to‐noise ratios, asymmetric peaks and migration time shifts. The usefulness of the proposed methodology is demonstrated in a comparative study of the metabolic profiles from baker's yeast (Saccharomyces cerevisiae) samples cultured at two temperatures, 30°C and 37°C. A total number of 80 metabolites were relevant to yeast samples differentiation at the two temperatures and almost 50 of them were tentatively identified based on their accurate experimental molecular mass. The results show that changes in amino acid, nucleotide and lipid metabolic pathways participated in the acclimatization of yeast cells to grow at 37°C.
Genotoxic effects of the antimalarial drug lumefantrine in human lymphocytes in vitro and computational prediction of the mechanism associated with its interaction with DNA
Authors: de Lucca Renato M.R. , Batista Júnior João , Fontes Cor J. Fernandes , de Oliveira Bahia Marcelo , Bassi‐Branco Carmen L.
Published: March 2015

Lumefantrine (LF) is an aryl‐amino alcohol antimalarial drug used in artemisinin‐based combination therapies against malaria worldwide. In this study, we investigated the genotoxic effects of LF in human lymphocytes in vitro, and the potential noncovalent interaction of LF with DNA using a 3D DNA‐docking model. The number of DNA breaks and the frequency of nuclear buds (NBUDS) was significantly increased (P < 0.01 and P <0. 05, respectively) at LF concentrations of 60, 80, and 100 µg/mL (LF60, LF80, and LF100, respectively). Frequency (‰) of micronuclei (MN) formation also increased after LF treatments. However, this was only significant for LF100 (P = 0.01) and LF80 (P = 0.001). LF did not affect the frequency of nucleoplasmic bridges (NPBs) (P = 0.12) or the nuclear division index (NDI) (P = 0.32). Computational analysis suggests that LF may interact noncovalently with DNA via the DNA minor groove surface with a predicted binding affinity energy of −7.2 kcal/mol and showing a favorable shape complementary to this groove. Our results suggest that LF has clastogenic effects in human lymphocytes in vitro due to noncovalent interaction with the minor groove of DNA. Environ. Mol. Mutagen. 56:556–562, 2015. © Wiley Periodicals, Inc.
Models of germ cell development and their application for toxicity studies
Authors: Ferreira Daniel W. , Allard Patrick
Published: March 2015

Germ cells are unique in their ability to transfer genetic information and traits from generation to generation. As such, the proper development of germ cells and the integrity of their genome are paramount to the health of organisms and the survival of species. Germ cells are also exquisitely sensitive to environmental influences although the testing of germ cell toxicity, especially in females, has proven particularly challenging. In this review, we first describe the remarkable odyssey of germ cells in mammals, with an emphasis on the female germline, from their initial specification early during embryogenesis to the generation of mature gametes in adults. We also describe the current methods used in germ cell toxicity testing and their limitations in examining the complex features of mammalian germ cell development. To bypass these challenges, we propose the use of alternative model systems such as Saccharomyces cerevisiae, Drosophila melanogaster, Caenorhabditis elegans, and in vitro germ cell methods that have distinct advantages over traditional toxicity models. We discuss the benefits and limitations of each approach, their application to germ cell toxicity studies, and the need for computational approaches to maximize the usefulness of these models. Together, the inclusion of these alternative germ cell toxicity models will be invaluable for the examination of stages not easily accessible in mammals as well as the large scale, high‐throughput investigation of germ cell toxicity. Environ. Mol. Mutagen. 56:637–649, 2015. © 2015 Wiley Periodicals, Inc.
Induction of centrosome amplification by formaldehyde, but not hydroquinone, in human lymphoblastoid TK6 cells
Authors: Ji Zhiying , McHale Cliona M. , Bersonda Jessica , Tung Judy , Smith Martyn T. , Zhang Luoping
Published: March 2015

Benzene and formaldehyde (FA) are important industrial chemicals and environmental pollutants that cause leukemia by inducing DNA damage and chromosome aberrations in hematopoietic stem cells (HSC), the target cells for leukemia. Our previous studies showed that workers exposed to benzene and FA exhibit increased levels of aneuploidy in their blood cells. As centrosome amplification is a common phenomenon in human cancers, including leukemia, and is associated with aneuploidy in carcinogenesis, we hypothesized that benzene and FA would induce centrosome amplification in vitro. We treated human lymphoblastoid TK6 cells with a range of concentrations of hydroquinone (HQ, a benzene metabolite) or FA for 24 h, allowed the cells to recover in fresh medium for 24 h, and examined centrosome amplification; chromosomal gain, loss, and breakage; and cytotoxicity. We included melphalan and etoposide, chemotherapeutic drugs that cause therapy‐related acute myeloid leukemia and that have been shown to induce centrosome amplification as well as chromosomal aneuploidy and breakage, as positive controls. Melphalan and etoposide induced centrosome amplification and chromosome gain and breakage in a dose‐dependent manner, at cytotoxic concentrations. HQ, though cytotoxic, did not induce centrosome amplification or any chromosomal aberration. FA‐induced centrosome amplification and cytotoxicity, but did not induce chromosomal aberrations. Our data suggest, for the first time, that centrosome amplification is a potential mechanism underlying FA‐induced leukemogenesis, but not benzene‐induced leukemogenesis, as mediated through HQ. Future studies are needed to delineate the mechanisms of centrosome amplification and its association with DNA damage, chromosomal aneuploidy and carcinogenesis, following exposure to FA. Environ. Mol. Mutagen. 56:535–544, 2015. © Wiley Periodicals, Inc.
Effect of incorporation of soy flour to wheat flour on nutritional and sensory quality of biscuits fortified with mushroom
Authors: Farzana Tasnim , Mohajan Suman
Published: March 2015

The research study was conducted to evaluate the quality characteristics of soy‐mushroom‐enriched biscuits which could be used as a protein supplemented cereal snack food. In this study, wheat flour was replaced with soy flour at different levels that is 20% (T3), 15% (T2), and 10% (T1) and without soy flour was kept as control (To). Mushroom was added in both biscuits. Biscuits were analyzed for chemical and sensory parameters. Protein content of soy flour‐supplemented biscuits increased from 11.07% to 17.86% as compared to control along with a significant increased in fat (17.36–20.89%), fiber (0.48–0.92%), iron (1.56–1.99 mg/100 g), and energy value (463–485 Kcal/g). Ash content also increased but not significantly. Results from chemical analyses and organoleptic evaluation indicate that good quality biscuits can be prepared by substituting wheat flour with 15% soy flour and addition of mushroom powders may affect the backing quality. Protein Energy Malnutrition (PEM) of the Bangladeshi population can be reduced through the development of biscuits in this way.
Human pulvinar functional organization and connectivity
Authors: Barron Daniel S. , Eickhoff Simon B. , Clos Mareike , Fox Peter T.
Published: March 2015

The human pulvinar is the largest thalamic area in terms of size and cortical connectivity. Although much is known about regional pulvinar structural anatomy, relatively little is known about pulvinar functional anatomy in humans. Cooccurrence of experimentally induced brain activity is a traditional metric used to establish interregional brain connectivity and forms the foundation of functional neuroimaging connectivity analyses. Because functional neuroimaging studies report task‐related coactivations within a standardized space, meta‐analysis of many whole‐brain studies can define the brain's interregional coactivation across many tasks. Such an analysis can also detect and define variations in functional coactivations within a particular region. Here we use coactivation profiles reported in ∼ 7,700 functional neuroimaging studies to parcellate and define the pulvinar's functional anatomy. Parcellation of the pulvinar's coactivation profile identified five clusters per pulvinar of distinct functional coactivation. These clusters showed a high degree of symmetry across hemispheres and correspondence with the human pulvinar's cytoarchitecture. We investigated the functional coactivation profiles of each resultant pulvinar cluster with meta‐analytic methods. By referencing existent neuroimaging and lesion‐deficit literature, these profiles make a case for regional pulvinar specialization within the larger human attention‐controlling network. Reference to this literature also informs specific hypotheses that can be tested in subsequent studies in healthy and clinical populations. Hum Brain Mapp 36:2417–2431, 2015. © 2015 Wiley Periodicals, Inc.