bluuebunny/crossref_metadata_2025 huggingface dataset:
Regression Analysis, Linear
Authors: Rosenthal Sonny
Published: November 2017

Linear regression is a versatile analysis. Simple linear regression shows the relationship between a dependent variable and an independent variable. Multiple regression controls for and models the effects of additional independent variables, and can include interaction effects. Hierarchical regression separates independent variables into theoretically meaningful blocks. A useful function of linear regression is to predict values of the dependent variable, although such prediction does not imply causation. Linear regression is available for a number of quantitative methods, including cross‐sectional surveys, longitudinal surveys, and experimental designs.
Research Program
Authors: Basil Michael , Potter Robert F.
Published: November 2017

An important foundation in our life in academia is our expertise. In most cases we think of our research program as a single “line” of research. Interestingly, however, a research program does not have to be constrained to a single paradigm, theory, or a singular line of research. A research program, does, however, benefit from connections that allow a synergy to develop among the theories, questions, or methods that are used. This entry offers suggestions to newer scholars on how to establish, build, and sustain a research program. These suggestions are culled from our own experiences as well as looking at those of others we have known or studied.
Research Question
Authors: Gayle Marks P.
Published: November 2017

Developing a central research question is fundamental to research design. The question focuses the topic and purpose of research by defining what will be studied and how. Research findings answer the question in a meaningful way and contribute knowledge to the discipline.
Response Latency
Authors: Samson Lelia
Published: November 2017

This entry introduces response latency as a communication science research method. Using response latency in experimental studies advances our comprehension of the cognitive processes involved both during message processing and as part of contemplating messages during subsequent questioning; it enables researchers to understand how audience members process, store, focus on, access, and think about media messages. This entry presents a short introduction into the origins, categories, and basic characteristics of the response latency measure. It then discusses the theoretical foundations of the use of response latency in media psychology experiments, its procedural and methodological considerations, its feasibility, validity, reliability as well as other issues pertinent to the use of response time in communication research.
Rhetoric of Social Intervention Model
Authors: Opt Susan K.
Published: November 2017

The Rhetoric of Social Intervention model is a systemic, communication approach for analyzing, interpreting, and designing interventions that encourage or discourage social‐system change. The model directs attention to the constitutive and functional process of ideology rather than its content. It primarily has been used in historical/critical case studies to foreground the communication dynamics generating and hindering social‐system change. Case studies indicate that practitioners might use the model as a means to monitor naming processes potentially to plan for social change and to create interventions to promote/impede change.
Rhetorical Criticism
Authors: Leeman Richard W.
Published: November 2017

Rhetorical criticism is the practice of interpreting the persuasive art found in a communicative act. The method may be employed for the purpose of illuminating theory or for better understanding a particular rhetorical event. A wide variety of critical approaches are available to the critic, but regardless of the critical lens employed, good rhetorical criticism evidences a close attention to the text and context, and an ability to thoughtfully and carefully use the critical approach selected in order to further one's understanding of the rhetorical act.
Rolling Cross‐Section
Authors: Kenski Kate , Filer Christine R.
Published: November 2017

The rolling cross‐section (RCS) design is a type of repeated cross‐sectional design that allows for the capturing of dynamic changes in public opinion. This entry compares the RCS design to single cross‐section and panel designs. The basic features of the RCS design are described. Then, the benefits and limitations of the RCS design are offered.
Sampling, Nonrandom
Authors: Saldaña Magdalena
Published: November 2017

Nonrandom sampling is the procedure in which members of a population are chosen based on criteria other than random selection. The widespread use of online surveys has increased the use of nonrandom sampling, and researchers have developed several methods to improve the representativeness of nonrandom samples. Convenience sampling, purposive sampling, quota sampling, and snowball sampling are the most common nonrandom sampling designs.
Sampling, Qualitative
Authors: Smulowitz Stacy
Published: November 2017

Each researcher has a different strategy when it comes to sampling. However, all researchers must make certain sampling decisions which will surely impact the outcome of their research. These decisions reflect the where, who, and when of conducting research. There are a variety of sampling methods available to researchers to help make the best sampling decision for each research study. This entry reviews the following types of sampling: purposeful, theoretical, random, stratified, systematic, criterion, snowball, homogeneous, maximum variation, typical instance, and extreme instance.
Scratch Notes
Authors: Arora Aarti B. , Bubp Rebecca L.
Published: November 2017

Scratch notes, also known as jots or jottings, are short notes written by a researcher, during observations and/or fieldwork, or shortly thereafter. Scratch notes are an important tool in conducting participant observation in qualitative research. Scratch notes employ various written forms such as shorthand, diagrams, phrases, words, images, and even doodles. This writing tool provides a visual mental marker that allows the researcher to recall distinct elements from their observation. These elements include but are not limited to, sensory details, emotions, behaviors, and interactions, which can add to or describe the observation or setting. The researcher later incorporates the scratch notes into their field notes. This entry explains how scratch notes are an essential tool in qualitative research which permits the researcher to design and record detailed field notes.
Secondary Research/Analysis
Authors: Hmielowski Jay D.
Published: November 2017

This entry provides an overview of secondary data analysis. It describes what constitutes secondary data analysis, the benefits of secondary data analysis, and the pitfalls of secondary data analysis. Finally, it proves some issues that scholars should think about before diving into a secondary data analysis project.
Secondary Task Reaction Time
Authors: Basil Michael
Published: November 2017

One important question for communication research is how people make sense of communication messages. At issue is the process of understanding those messages and the difficulty or the amount of effort a person needs to devote to understanding the messages. Because our mental resources are believed to be limited, one way to measure the effort being expended is by judging how many resources remain. Specifically, while people are engaged in the primary task of processing a communication message, we gauge the remaining resources by measuring the efficiency with which they can perform a secondary task. After a review of the foundations and research behind this measure, its use and prescriptions for its use are provided.
Statistical Significance (Testing)
Authors: Lepa Steffen
Published: November 2017

Statistical significance testing is a central technique for everyday empirical‐quantitative work in media and communication research. Its most common form, the null hypothesis significance test, represents a well‐established method of legitimating knowledge claims drawn from statistical analyses based on random samples. Nevertheless, intended epistemological meaning of the procedure and also correct interpretation of its result are commonly misunderstood. Furthermore, a prevalent view of regarding the “significance” of statistical estimations as providing a measure for meaningfulness of study results has also led to various forms of questionable research and publication practices. Nevertheless, significance testing is still a well‐accepted technique in our field. This entry explains the different versions and their interpretation, and tries to abolish common misunderstandings. It also gives an overview on extensions and alternatives that have been historically developed, as well as practical recommendations for meaningful reporting of significance test results.
Statistics, Descriptive
Authors: Naab Teresa K.
Published: November 2017

Descriptive statistics are procedures to summarize and present a set of observations or a set of data. This is achieved by displaying frequency distributions in tables and in graphical format (e.g., bar chart, histogram, polygon), by computing measures of central tendency (e.g., mode, median, mean), and measures of variability (e.g., range, mean absolute deviation around the mean, variance, standard deviation). The selection of appropriate measures depends on the measurement scale of the variables, which can be nominal, ordinal, interval, or ratio.
Structural Equation Modeling
Authors: Hutchens Myiah J.
Published: November 2017

Structural equation modeling is a class of statistical models that includes confirmatory factor analysis, path analysis, and hybrid models, among others. It is a flexible framework that can be used to test causal and correlational data, and can be used for both exploratory and confirmatory processes. This entry describes the basic model‐building process for all structural equation models. Additionally, distinctions between various models, all of which fall under the umbrella of structural equation modeling, are addressed.
Survival Analysis
Authors: Arendt Florian
Published: November 2017

Survival analysis is defined as a set of methods for analyzing time to event data. The main outcome is the time until the occurrence of an event (e.g., cessation of smoking after exposure to health‐related messages). This entry introduces one of the most popular approaches, the Kaplan–Meier method. The method includes a graphical depiction in the form of a step function with sudden changes in estimated probabilities at times at which the event of interest occurred. Unlike traditional statistical approaches such as ANOVA or regression analysis, survival analysis using the Kaplan–Meier method uses information from both “censored” and “uncensored” observations. Importantly, survival functions of two or more groups of an experimental or nonexperimental between‐subjects factor can be compared for significant differences.
Test Theory, Classical Test Theory
Authors: Frey Felix
Published: November 2017

Test theory is concerned with methods and criteria for the construction, evaluation and comparison of “tests,” that is, procedures for measuring observables or constructs of interest. These methods and criteria rest on assumptions about the composition of measurements as well as the properties of these components and the relationship among them. The most prominent test‐theoretical frameworks are classical test theory (CTT) and item response theory (IRT), including the Rasch model. Within the CTT framework influential quality criteria like objectivity, reliability, and validity as well as methods for assessing them have been developed. Considering the small number of simple assumptions made by CTT, it has proven quite fruitful, even in comparison to “modern” test theories (e.g., IRT) which overcome certain limitations of CTT at the expense of stronger assumptions and greater mathematical complexity.
Theory and Empirically Based Theory Development
Authors: Hepp Andreas
Published: November 2017

Theory, as defined in this entry, is understood as based on empirical (media and communication) research in a dual way: on the one hand, as guiding this research and, on the other hand, as a result of this research. Due to recent developments in the field of media and communications, many established theories—which mainly were rooted in ideas and models of so‐called “mass communication”—seem to be limited for describing present processes of media and communications. As a consequence, empirically based theory development has gained high importance, and is therefore outlined as fundamental for media and communication research.
Validity
Authors: Lynch Teresa
Published: November 2017

Validity refers to two separate areas of concern in communication research. The first of those areas is the extent to which a measure reflects its intended concept. The term is distinct from reliability, although if a measure is valid this assumes that the measure is also reliable. Three established dimensions of validity exist:
content
,
criterion
, and
construct validity
. Statistical techniques such as confirmatory factor analysis and multitrait‐multimethod modeling can provide empirical evidence of validity. The second area in which scholars may consider issues related to validity is in experimental design. Experimental validity consists of two components,
internal validity
and
external validity
. Unlike measurement validity, experimental validity relies on logic, delineation, and establishment of cause‐and‐effect relationships.
Verification and Falsification
Authors: Fretwurst Benjamin
Published: November 2017

“Falsification” is to be understood as the refutation of statements, and in contrast, “verification” refers to statements that are shown to be true. The goal of science is to create knowledge by identifying true statements as true (verified) and false statements as false (falsified). Popper showed that hypothesis cannot be empirically verified but only falsified. In the social sciences, with their probabilistic statements about large quantities of individual objects, empirical tests are performed using samples. The statistical analyses of random samples are the protocol sentences of social science and therefore the basis of falsification and verification in empirical communication science too.
Digital Ethnography
Authors: Kaur‐Gill Satveer , Dutta Mohan J.
Published: November 2017

Digital ethnography, an emerging field in ethnography poses questions about the communicative phenomena taking place in a technologically mediated world. Digitized spaces today are where communities of all kinds exist. Experiences of day‐to‐day realities take place in digitally connected spaces and the storied lives of communities are told through the online sphere. These spaces are where identities are negotiated, cultural practices enacted, and social phenomena of various kinds are manifested, a worthy area for interpretation for ethnographers interested in the tradition of story‐telling to understand the social world. The entry discusses digital ethnography and what the process entails, the emergence of the method of inquiry, and the various debates that currently exist regarding the value of conducting ethnography in online spaces. It presents the various issues and contentions digital ethnographers grapple with when identifying their field site for interpretation, and considers various perspectives on the nature of conducting digital ethnography.
Temperature‐Regulated Gene Expression
Authors: Schöffl Friedrich , Panikulangara Tressa Jacob
Published: November 2017

The sections in this article are

Heat Stress

Cold Stress

Perspectives for Plant Biotechnology
Applications of Inducible Transcription in Plant Research and Biotechnology
Authors: Tomsett Brian , Tregova Angela , Caddick Mark
Published: November 2017

The sections in this article are

Introduction

Conditional Expression of Transgenes

Applications to Plant Functional Genomics

Potential Applications to Plant Biotechnology

Conclusions
Phytochromes
Authors: Hiltbrunner Andreas , Nagy Ferenc , Schäfer Eberhard
Published: November 2017

The sections in this article are

Introduction

Historical Aspects

Properties ofphyAin vitro

Properties in Yeast Cells

In vivoProperties of Phytochromes

Intracellular Localisation of Phytochromes

Intracellular Localisation ofphyBin Dark and Light

Intracellular Localisation ofphyAin Dark and Light

Intracellular Localisation ofphyC,phyDandphyEin Dark and Light

Phytochrome/PIF3Co‐Localisation and Nuclear Speckles

Regulation of Intracellular Localisation of Phytochromes

Acknowledgements
Phototropins and OtherLOV‐Containing Proteins
Authors: Christie John M.
Published: November 2017

The sections in this article are

Introduction

Phototropins and Their Biological Functions

Phototropin Structure, Localization and Activity

Light Sensing by theLOVDomains

Phototropin Signaling

OtherLOV‐Containing Proteins

Conclusions and Future Perspectives

Acknowledgements
The Role of Ubiquitin/Proteasome‐Mediated Proteolysis in Photoreceptor Action
Authors: Feng Suhua , Deng Xing Wang
Published: November 2017

The sections in this article are

Introduction

Overview of the Ubiquitin/Proteasome System

Role ofCOP/DET/FUSProteins in Photoreceptor‐Mediated Signal Transduction and Ubiquitin/Proteasome‐Mediated Proteolysis

Other Connection Points between Light Signaling and Selective Proteolysis

Concluding Remarks

Note
Red:Far‐Red Ratio Perception and Shade Avoidance
Authors: Franklin Keara A. , Whitelam Garry C.
Published: November 2017

The sections in this article are

Introduction

Natural Light Environment

Shade Avoidance Syndrome

Phytochrome Regulation of Shade Avoidance

The Roles of Other Signals in Shade Avoidance

Signalling in Shade Avoidance

The Adaptive Value of Shade Avoidance

Conclusions
Import of Nuclear‐Encoded Mitochondrial Proteins
Authors: Glaser Elzbieta , Whelan James
Published: November 2017

The sections in this article are

Introduction

Mitochondrial‐Targeting Signals

Cytosolic Factors

Sorting of Precursors between Mitochondria and Chloroplasts

Translocation Machinery

Proteolytic Events

Evolution of Protein Import Components

Genomic Perspective of Mitochondrial Protein Import Components

Concluding Remarks

Acknowledgements
Mitochondrial Electron Transport and Oxidative Stress
Authors: Møller Ian M.
Published: November 2017

The sections in this article are

Introduction

The Standard Electron Transport Chain

The Alternative Oxidase

NAD(P)HDehydrogenases

Substrates for theNAD(P)HDehydrogenases

Oxidative Stress –ROSTurnover

MitochondrialDNAand Lipid Oxidation

Mitochondrial Protein Oxidation

Fate of Oxidised Proteins

How to Prevent the Transfer of Oxidative Damage to the Next Generation?

Concluding Remarks

Acknowledgements
Cell Cycle Control during Leaf Development
Authors: Fleming Andrew J.
Published: November 2017

The sections in this article are

Introduction

The Cell Cycle and Cell Division during Leaf Initiation

The Cell Cycle and Cell Division during Leaf Growth

The Cell Cycle and Cell Division during Leaf Differentiation

Conclusions

Acknowledgments
Stress Reduction of 3D Printed Compliance‐Tailored Multilayers
Authors: Kumar Shanmugam , Wardle Brian L. , Arif Muhamad F. , Ubaid Jabir
Published: November 2017

Multilayered multi‐material interfaces are encountered in an array of fields. Here, enhanced mechanical performance of such multi‐material interfaces is demonstrated, focusing on strength and stiffness, by employing bondlayers with spatially‐tuned elastic properties realized via 3D printing. Compliance of the bondlayer is varied along the bondlength with increased compliance at the ends to relieve stress concentrations. Experimental testing to failure of a tri‐layered assembly in a single‐lap joint configuration, including optical strain mapping, reveals that the stress and strain redistribution of the compliance‐tailored bondlayer increases strength by 100% and toughness by 60%, compared to a constant modulus bondlayer, while maintaining the stiffness of the joint with the homogeneous stiff bondlayer. Analyses show that the stress concentrations for both peel and shear stress in the bondlayer have a global minimum when the compliant bond at the lap end comprises ≈10% of the bondlength, and further that increased multilayer performance also holds for long (relative to critical shear transfer length) bondlengths. Damage and failure resistance of multi‐material interfaces can be improved substantially via the compliance‐tailoring demonstrated here, with immediate relevance in additive manufacturing joining applications, and shows promise for generalized joining applications including adhesive bonding.
Functional Defective Metal‐Organic Coordinated Network of Mesostructured Nanoframes for Enhanced Electrocatalysis
Authors: Yilmaz Gamze , Tan Chuan Fu , Hong Minghui , Ho Ghim Wei
Published: November 2017

Although defects are traditionally perceived as undesired feature, the prevalence of tenacious low‐coordinated defects can instead give rise to desirable functionalities. Here, a spontaneous etching of mesostructured crystal, cyanide‐bridged cobalt‐iron (CN‐CoFe) organometallic hybrid into atomically crafted open framework that is populated with erosion‐tolerant high surface energy defects is presented. Unprecedently, the distinct mechanistic etching pathway dictated by the mesostructured assembly, bulk defects, and strong intercoordinated cyanide‐bridged hybrid mediates not only formation of excess low‐coordinated defects but also more importantly stabilizes them against prevailing dissolution and migration issues. Clearly, the heteropolynuclear cyanide bonded inorganic mesostructured clusters sanction the restructuring of a new breed of stable organometallic polymorph with 3D accessible structure enclosed by electrochemical active atomic stepped edges and high index facets. The exceptional electrocatalysis performance supports the assertion that defective mesostructured polymorph offers a new material paradigm to synthetically tailor the elementary building block constituents toward functional materials.
Avoiding Energy Loss on TADF Emitters: Controlling the Dual Conformations of D–A Structure Molecules Based on the Pseudoplanar Segments
Authors: Wang Kai , Zheng Cai‐Jun , Liu Wei , Liang Ke , Shi Yi‐Zhong , Tao Si‐Lu , Lee Chun‐Sing , Ou Xue‐Mei , Zhang Xiao‐Hong
Published: November 2017

The recent introduction of thermally activated delayed fluorescence (TADF) emitters is regarded as an important breakthrough for the development of high efficiency organic light‐emitting devices (OLEDs). The planar D and A groups are generally used to construct TADF emitters for their rigid structure and large steric hindrance. In this work, it is shown that many frequently used nonaromatic (noncontinuous conjugation or without satisfying Hückel's rule) planar segments, such as 9,9‐dimethyl‐9,10‐dihydroacridine, are actually pseudoplanar segments and have two possible conformations–a planar form and a crooked form. Molecules constructed from pseudoplanar segments can thus have two corresponding conformations. Their existence can have significant impact on the performance of many TADF emitters. Two design strategies are presented for addressing the problem by either (1) increasing the rigidity of these groups to suppress its crooked form or (2) increasing the steric hindrance of the linked group to minimize energy of the emitters with the highly twisted form. Following these strategies, two new emitters are synthesized accordingly and successfully applied in OLEDs demonstrating high external quantum efficiencies (20.2% and 18.3%).
Surface Wrinkling and Porosity of Polymer Particles toward Biological and Biomedical Applications
Authors: Visaveliya Nikunjkumar R. , Leishman Christopher W. , Ng Kara , Yehya Nicolas , Tobar Nelson , Eisele Dorthe M. , Köhler Johann Michael
Published: November 2017

Polymer particles are promising particulate materials for renowned biomedical applications such as targeted drug delivery, tissue engineering, and biosensing. Surface properties of the polymer particles are of key importance for biomedical applications because they directly interact with biological systems. Particularly, wrinkled as well as porous surfaces possess an enhanced ability for cell attachment without any additional chemical modification. Therefore, a key objective is to fabricate the particles with desired degree of wrinkles and porosity. Many methods such as solvent evaporation, plasma treatment, emulsion instability, and electrospraying are being employed for the generation of porous, wrinkled and/or textured surfaces. Advantageously, an application of microfluidics can support the induction of surface instabilities on droplets in a case of droplet‐based systems. Furthermore, microfluidics allows tuning of size and shape of the generated droplets as well as particles with desired surface textures. In this minireview article, surface characteristics (especially surface wrinkles and porosity) of the hydrophobic and hydrophilic polymer particles are presented for the potential applications toward biological as well as biomedical field. In addition, the impact of microfluidics is highlighted in order to produce the polymer particles of functional surface properties.
Charge and Discharge Processes and Sodium Storage in Disodium Pyridine‐2,5‐Dicarboxylate Anode—Insights from Experiments and Theory
Authors: Padhy Harihara , Chen Yingqian , Lüder Johann , Gajella Satyanarayana Reddy , Manzhos Sergei , Balaya Palani
Published: November 2017

A combined experimental and computational study of disodium pyridine‐2,5‐dicarboxylate (Na2PDC) is presented exploring the possibility of using it as a potential anode for organic sodium‐ion batteries. This electrode material can reversibly insert/release two Na cations per formula unit, resulting in high reversible capacity of 270 mA h g−1 (236 mA h g−1 after accounting for the contribution from Super P carbon) with excellent cyclability 225 mA h g−1, with retention of 83% capacity after 100 cycles, and good rate performance with reversible capacity of 138 mA h g−1 at a 5 C rate. The performance of disodium pyridine dicarboxylate is therefore found to be superior to that of the related and well investigated disodium terephthalate. The material shows two voltage plateaus at about 0.6 V up to Na2+1PDC and then 0.4 V up to full sodiation, Na2+2PDC. The first plateau is attributed to the coordination of inserted Na to nitrogen atoms with bond formation, i.e., a different mechanism from the terephthalate analog. The subsequent plateau is due to coordination to the carboxylic groups.
Long Cycle Life, Low Self‐Discharge Sodium–Selenium Batteries with High Selenium Loading and Suppressed Polyselenide Shuttling
Authors: Wang Hui , Jiang Yang , Manthiram Arumugam
Published: November 2017

The use of selenium as a cathode in rechargeable sodium–selenium batteries is hampered by low Se loading, inferior electrode kinetics, and polyselenide shuttling between the cathode and anode. Here a high‐performance sodium–selenium cell is presented by coupling a binder‐free, self‐interwoven carbon nanofiber–selenium cathode with a light‐weight carbon‐coated bifunctional separator. With this strategy, electrodes with a high Se mass loading (4.4 mg cm−2) render high reversible capacities of 599 mA h g−1 at 0.1C rate and 382 mA h g−1 at 5C rate. In addition, this novel cell offers good shelf‐life with a low self‐discharge, retaining 93.4% of its initial capacity even after resting for six months. As evidenced by experimental and density functional theory analysis, the remarkable dynamic (cycle life) and static (shelf‐life) stabilities originate from the high electrical conductivity, improved Na‐ion accessibility through the 3D interconnected open channels, and highly restrained polyselenide shuttle. The results demonstrate the viability of high‐performance sodium–selenium batteries with high selenium loading.
Firm reputation, advertising investment, and price premium: The role of collective brand membership in high‐quality wines
Authors: Sellers‐Rubio Ricardo , Mas‐Ruiz Francisco , Sancho‐Esper Franco
Published: November 2017

Research has recognized that the price of an experience good is not only determined by firm and collective reputation, which act as proxies of firm product quality, but also by the firm's advertising investment. This study examines whether pricing these goods as a function of firm advertising investment and firm reputation depends on a collective, versus noncollective, brand strategy. The central assumption of this article is that a collective brand can increase perceived differentiation among the individual brands associated with it, and thus, that collective brand membership can moderate the effects of firm advertising investment and firm reputation on product price. The results obtained from a panel of companies in an experience‐goods industry (i.e., wineries) between 1999 and 2013 show that the relative effect of collective brand membership on product price is higher when the company has higher advertising investment and a higher reputation. [EconLit citations:Q11, Q13, M37]
Numerical simulation on flow behavior of twin‐liquid films over a vertical plate with an open window
Authors: Xie Hanguang , Hu Jianguang , Dai Gance
Published: November 2017

A novel element for gas–liquid contact, a plate with rectangular windows was designed to enhance absorption process. Coexistence and interaction of wall‐bounded films and confined free films named as “twin‐liquid films” were observed on the plate. Volume of fluid (VOF) method was used to simulate its flow behavior. Flow phenomena such as flow around a step‐in, jet impingement, varicose waves, and sinuous waves were observed. Different from thin films flow on an unperforated plate, larger mean velocity, thinner film thickness, more intensive capillary waves, and stronger vorticity on the free surfaces were detected inside the window, and the disturbances could propagate over the whole plate. Three‐dimensional simulation results generally agreed with our experimental observations and further demonstrated complex wavy structures both inside and outside the window. The results would broaden traditional knowledge of liquid films flow and clarify the mechanism of mass transfer intensification for the plate with windows. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1458–1468, 2018
Studies on mild catalytic synthesis of methyl acrylate via one‐step aldol reaction
Authors: Wang Gang , Sararuk Chidchon , Li Zeng‐Xi , Li Chun‐Shan , Wang Hui , Zhang Suo‐Jiang
Published: November 2017

One‐step catalytic synthesis of methyl acrylate from methyl acetate and trioxane, with 90.7% yield and 91.8% selectivity, was realized at 10–25°5. NMR analysis confirmed the ester enolization with generation of [i‐Pr2EtN‐H]+[TfO]− in the presence of i‐Pr2EtN and Bu2BOTf, which was affected by solvent and base. The depolymerization of trioxane into formaldehyde was catalyzed by Bu2BOTf. The in‐situ catalytic mechanism and efficiency of [i‐Pr2EtN‐H]+[TfO]− was determined and analyzed. Mechanism‐based kinetic and thermodynamic studies were conducted for better understanding of this route. Also the primary process design and product separation simulation were carried out. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1359–1372, 2018
DEM study on the discharge characteristics of lognormal particle size distributions from a conical hopper
Authors: Zhao Ya , Yang Shiliang , Zhang Liangqi , Chew Jia Wei
Published: November 2017

This study employs the discrete element method (DEM) to investigate the impact of the widths of lognormal particle size distributions (PSDs) with the same mean particle diameter on hopper discharge behaviors, namely, discharge rate, particle velocities, and size‐segregation. Results reveal that (i) the hopper discharge rate decreases as PSD width increases; (ii) the mean discharge rates are constant with time, but the fluctuations increase as the PSD width increases; (iii) the overall size‐segregation increases with PSD width; (iv) the overall mean particle diameters of the narrower PSDs do not exceed the initial mean of 5 mm, whereas that of wider ones do; (v) the relationship between PSD width and particle velocities is non‐monotonic with no consistent trends; and (vi) no direct correlation exists between particle velocity and size‐segregation. The results here provide valuable insights on the behavior of the prevalent polydisperse mixtures in hoppers. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1174–1190, 2018
Adapting the T0‐T4 implementation science model to occupational health and safety in agriculture, forestry, and fishing: A scoping review
Authors: Tinc Pamela J. , Gadomski Anne , Sorensen Julie A. , Weinehall Lars , Jenkins Paul , Lindvall Kristina
Published: November 2017

Background

Despite much research to develop life‐saving innovations for the agriculture, forestry, and fishing workforce, these populations continue to face the highest fatal and non‐fatal injury rates in the United States, as many of these solutions are not fully adopted.

Methods

A scoping review was conducted to provide an overview of research to practice efforts in this field. The language used to describe these initiatives, the utility of the NIH T0‐T4 model, and the progress along the research to practice continuum were examined.

Results

Fourteen eligible references demonstrated that progress in implementation science is lacking and that there is little consistency in how researchers apply the T0‐T4 model; thus, a new model is presented.

Conclusions

Researchers in this field face several challenges when moving from research to practice. While some challenges are addressed with the proposed model, additional resources and infrastructure to support such initiatives are necessary.
Occupational generalized urticaria and anaphylaxis after inhalation of cefuroxime in a nurse
Authors: Merget Rolf , Sander Ingrid , Fartasch Manigé , van Kampen Vera , Röseler Stefani , Merk Hans , Wurpts Gerda , Raulf Monika , Brüning Thomas
Published: November 2017

We present the case of a 53 years old nonatopic female nurse who experienced repeated anaphylactic reactions at work without involvement in drug‐specific tasks such as crushing of tablets or preparation of injections. The causal allergen was not identified until a further severe anaphylactic reaction occurred after oral use of cefuroxime during a respiratory infection. Sensitization to cefuroxime was demonstrated by specific IgE, basophil activation test and skin prick test. An inhalation challenge with a dosimeter induced generalized urticaria after a cumulative dose of about 10 μg of the drug, but no asthmatic reaction. Complete exposure cessation was initiated and a 1‐year follow‐up was without further allergic reactions. We conclude that work‐related systemic allergic reactions to β‐lactam antibiotics may occur in nurses after inhalation of low doses and without perceived association with drug‐specific tasks like handling of antibiotics.
A retrospective analysis of cardiometabolic health in a large cohort of truck drivers compared to the American working population
Authors: Thiese Matthew S. , Hanowski Richard J. , Moffitt Gary , Kales Stefanos N. , Porter Richard. J. , Ronna Brenden , Hartenbaum Natalie , Hegmann Kurt T.
Published: November 2017

Background

Truck drivers face many health challenges, including lifestyle, diet, inactivity, stressors, and social support.

Methods

A repeated cross‐sectional analysis compared 88,246 truck drivers with data from (n = 11 918) the National Health and Nutrition Examination Survey (NHANES). Trends over time for body mass index (BMI), high blood pressure, diabetes mellitus, heart disease, and sleep disorders were analyzed, adjusting for potential confounders.

Results

Truck drivers had significantly worsening health metrics between 2005 and 2012 compared to NHANES participants. Truck drivers were significantly more likely to be obese and morbidly obese with prevalence odds ratios (POR) and 95% confidence intervals (95%CI) of 1.99 (1.87, 2.13) and 2.34 (2.16, 2.54), respectively. Measured blood pressure, self‐reported high blood pressure, diabetes mellitus, and heart disease all significantly increased. Also, sleep disorders increased among truck drivers from 2005 to 2012 (POR = 6.55, 95%CI 5.68, 7.55).

Conclusion

These data suggest disproportionate increases in poor health among truck drivers from 2005 to 2012.
Entwicklung einer DNA‐Polymerase für die direkte m6A‐Sequenzierung
Authors: Aschenbrenner Joos , Werner Stephan , Marchand Virginie , Adam Martina , Motorin Yuri , Helm Mark , Marx Andreas
Published: November 2017

Methoden zur Analyse von RNA‐Modifikationen sind essenziell für das Forschungsfeld der Epitranskriptomik. N6‐Methyladenosin (m6A) ist die häufigste Modifikation in der mRNA von Säugetieren und erfüllt Funktionen in der Regulation der Genexpression. Techniken zur Detektion dieser Modifikation basieren derzeit auf der Anreicherung von m6A‐haltigen RNA‐Fragmenten durch Antikörper. Dieser m6A‐spezifische Schritt vor der Sequenzierung ist nötig, da die Information über die Modifikation während der reversen Transkription (RT) gelöscht wird. Um die Nachteile einer solchen indirekten Detektion zu überwinden, haben wir uns zum Ziel gesetzt, neue DNA‐Polymerasen zu entwickeln, die eine direkte m6A‐Sequenzierung ermöglichen. Zu diesem Zweck wurde ein Verfahren etabliert, das die Identifizierung von RT‐aktiven KlenTaq‐DNA‐Polymerase‐Varianten mit einer erhöhten Fehleinbaurate gegenüber m6A ermöglicht. So konnten m6A‐haltige Stellen direkt aus RNA‐Sequenzierungsdaten identifiziert werden.
Mild condition dissolution of high molecular weight cotton cellulose in 1‐butyl‐3‐methylimidazolium acetate/N,N‐dimethylacetamide solvent system
Authors: Acharya Sanjit , Hu Yang , Abidi Noureddine
Published: November 2017

To investigate the effective dissolution of high molecular weight (MW) cellulose macromolecules at ambient conditions, cellulose (DP > 4,000) derived from cotton fiber waste was dissolved in 1‐butyl‐3‐methylimidazolium acetate (BMIMAc)/N,N‐dimethylacetamide (DMAc) solvent in this study. High MW cotton cellulose achieves a solubility between 3% and 5% cellulose concentrations using BMIMAc/DMAc solvent at ambient conditions. Rheological studies showed that all cellulose/solvent solutions displayed a shear thinning behavior. Results from the physical characterization revealed that well‐dissolved cotton cellulose exhibited highly porous structure and the crystalline structure of cotton cellulose was highly disrupted during dissolution and regeneration processes. This study is the first to report on the ability of BMIMAc/DMAc solvent system to dissolve high MW cellulose under ambient conditions, which represents an energy‐saving and environmentally friendly approach. As cellulose used in this study was derived from low quality waste cotton fibers, the potential utilization of such cotton cellulose may create a competitive market for low quality cotton and target advanced applications of cellulose‐based products for green materials and energy. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45928.
A new substitute for formalin: Application to embalming cadavers
Authors: Haizuka Yoshinori , Nagase Miki , Takashino Satoshi , Kobayashi Yasushi , Fujikura Yoshihisa , Matsumura George
Published: November 2017

The development of formalin‐free fixatives is an urgent issue in gross anatomy because of the health hazard and the tissue‐hardening actions of formalin. We recently identified the fixative, antimicrobial, and preservative effects of N‐vinyl‐2‐pyrrolidone (NVP), a precursor of the water‐soluble macromolecular polymer polyvinylpyrrolidone, in animal experiments. The aim of the present study is to investigate whether NVP solution can be used as an alternative to formalin in human cadaveric dissection. Twelve donated cadavers were infused with NVP via the femoral and common carotid arteries using a peristaltic pump. Experienced teaching staff members in our department dissected the cadavers and examined their macroanatomical properties. The NVP‐embalmed corpses showed no sign of decomposition or fungal growth. The bodies remained soft and flexible. Notably, the shoulder, elbow, wrist, phalangeal, hip, knee, cervical spine, and temporomandibular joints were highly mobile, almost equivalent to those of living individuals. The range of motion of most joints was greater in the NVP‐fixed than formalin‐fixed cadavers. Under the dermis, the subcutaneous fat was markedly reduced and the connective tissues were transparent, so the ligaments, cutaneous nerves, and veins were easily discernible. The abdominal wall and the visceral organs remained pliable and elastic, resembling those of fresh cadavers. The lungs, liver, and gastrointestinal tract were moveable in the thoracic and abdominal cavities and were readily isolated. NVP can be used successfully as a fixative and preservative solution for human cadavers; furthermore, NVP‐embalmed bodies could be valuable for learning clinical skills and for training, and for developing innovative medical devices. Clin. Anat. 31:90–98, 2018. © 2017 Wiley Periodicals, Inc.
Types of value and cost in consumer–green brands relationship and loyalty behaviour
Authors: Papista Erifili , Chrysochou Polymeros , Krystallis Athanasios , Dimitriadis Sergios
Published: November 2017

Recent literature has proposed the dynamic construct of customer value (CV) as an alternative approach to studying proenvironmental consumer purchase and loyalty behaviour. This study empirically tests and validates a model pertaining to the factors that motivate and/or hinder the development of the relationship between consumers and green brands. Findings from a survey on green brands in the detergent category indicate that a set of value dimensions and (purchase) costs have a significant influence on perceptions of CV, which, as an overall assessment construct, mediate the relationship between value dimensions and costs and loyalty to the green brand. This research also examines the moderating effect of involvement on the relationships between the 3 antecedents (value dimensions, purchase costs, and switching costs) and perceived CV. Overall, the current study offers a multiattribute understanding of consumers' relational behaviour, concluding with several value‐enhancing and cost‐minimising implications for green marketing practitioners.
The sustainability‐age dilemma: A theory of (un)planned behaviour via influencers
Authors: Johnstone Leanne , Lindh Cecilia
Published: November 2017

This study investigates the relation between age and sustainability awareness for consumers via the third, mediating variable of influencers to reduce the intention‐behaviour purchase gap. It proposes that traditional theories of planned behaviour are limited as they do not account for unconscious and indirect pathways to axiological change. A structural model with the 3 constructs of age, influencers, and sustainability awareness is tested with linear structural relations on a sample of 788 consumers, complemented with focus groups and interviews to generate deeper insight into the model's constructs. The results demonstrate a relationship between age and sustainability awareness, as well as between the importance of influencers for increased sustainability awareness in younger consumers, namely, millennials. This suggests that practitioners should work with influencers perceived as trustworthy to increase sustainability awareness for the millennial subset consumer group. The methodology applies a mixed approach, interpreting both qualitative and quantitative aspects, and contributes to the ethical consumerism literature with new knowledge on age differences connected to sustainability awareness, particularly highlighting on the influence of influencers for the younger generations.
Nucleophilic Water Capture or Proton Loss: Single Amino Acid Switch Converts δ‐Cadinene Synthase into Germacradien‐4‐ol Synthase
Authors: Loizzi Marianna , González Veronica , Miller David J. , Allemann Rudolf K.
Published: November 2017

δ‐Cadinene synthase is a sesquiterpene cyclase that utilises the universal achiral precursor farnesyl diphosphate (FDP) to generate predominantly the bicyclic sesquiterpene δ‐cadinene and about 2 % germacradien‐4‐ol, which is also generated from FDP by the cyclase germacradien‐4‐ol synthase. Herein, the mechanism by which sesquiterpene synthases discriminate between deprotonation and reaction with a nucleophilic water molecule was investigated by site‐directed mutagenesis of δ‐cadinene synthase. If W279 in δ‐cadinene synthase was replaced with various smaller amino acids, the ratio of alcohol versus hydrocarbon product was directly proportional to the van der Waals volume of the amino acid side chain. DCS‐W279A is a catalytically highly efficient germacradien‐4‐ol synthase (kcat/KM=1.4×10−3 μm s−1) that produces predominantly germacradien‐4‐ol in addition to 11 % δ‐cadinene. Water capture is not achieved through strategic positioning of a water molecule in the active site, but through a coordinated series of loop movements that allow bulk water access to the final carbocation in the active site prior to product release.
A T7 RNA Polymerase Mutant Enhances the Yield of 5′‐Thienoguanosine‐Initiated RNAs
Authors: Lyon Seth , Gopalan Venkat
Published: November 2017

Spectroscopic methods, which are used to establish RNA structure–function relationships, require strategies for post‐synthetic, site‐specific incorporation of chemical probes into target RNAs. For RNAs larger than 50 nt, the enzymatic incorporation of a nucleoside or nucleotide monophosphate guanosine analogue (G analogue) at their 5′‐end is routinely achieved by T7 RNA polymerase (T7RNAP)‐mediated in vitro transcription (IVT) of the appropriate DNA template containing a GTP‐initiating class III Φ6.5 promoter. However, when high G analogue:GTP ratios are used to bias G analogue incorporation at the 5′‐end, RNA yield is compromised. Here, we show that the use of a T7RNAP P266L mutant in IVT with 10:1 thienoguanosine (thG):GTP increased the percent incorporation and yield of 5′‐thG‐initiated precursor tRNA for a net ≈threefold gain compared to IVT with wild‐type T7RNAP. We also demonstrated that a one‐pot multienzyme approach, consisting of transcription by T7RNAP P266L and post‐transcriptional cleanup by polyphosphatase and an exonuclease, led to essentially near‐homogeneous 5′‐thG‐modified transcripts. This approach should be of broad utility in preparing 5′‐modified RNAs.
Flavin‐N5 Covalent Intermediate in a Nonredox Dehalogenation Reaction Catalyzed by an Atypical Flavoenzyme
Authors: Dai Yumin , Kizjakina Karina , Campbell Ashley C. , Korasick David A. , Tanner John J. , Sobrado Pablo
Published: November 2017

The flavin‐dependent enzyme 2‐haloacrylate hydratase (2‐HAH) catalyzes the conversion of 2‐chloroacrylate, a major component in the manufacture of acrylic polymers, to pyruvate. The enzyme was expressed in Escherichia coli, purified, and characterized. 2‐HAH was shown to be monomeric in solution and contained a non‐covalent, yet tightly bound, flavin adenine dinucleotide (FAD). Although the catalyzed reaction was redox‐neutral, 2‐HAH was active only in the reduced state. A covalent flavin‐substrate intermediate, consistent with the flavin‐acrylate iminium ion, was trapped with cyanoborohydride and characterized by mass spectrometry. Small‐angle X‐ray scattering was consistent with 2‐HAH belonging to the succinate dehydrogenase/fumarate reductase family of flavoproteins. These studies establish 2‐HAH as a novel noncanonical flavoenzyme.