bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of O‐methylated (−)‐epigallocatechin gallate (EGCG) on LPS‐induced osteoclastogenesis, bone resorption, and alveolar bone loss in mice
Authors: Tominari Tsukasa , Ichimaru Ryota , Yoshinouchi Shosei , Matsumoto Chiho , Watanabe Kenta , Hirata Michiko , Grundler Florian M.W. , Inada Masaki , Miyaura Chisato
Published: November 2017

(−)‐Epigallocatechin‐3‐O‐gallate (EGCG), present in green tea, exhibits antioxidant and antiallergy effects. EGCG3″Me, a 3‐O‐methylated derivative of EGCG, has been reported to show similar biological functions; the inhibitory activity of EGCG3″Me in a mouse allergy model was more potent than that of EGCG, probably due to the efficiency of absorption from the intestine. However, the functional potency of these EGCGs is controversial in each disease model. We previously observed that EGCG suppressed inflammatory bone resorption and prevented alveolar bone loss in a mouse model of periodontosis. In this study, we examined the role of EGCG3″Me in bone resorption using a mouse model of periodontitis. Lipopolysaccharide (LPS)‐induced osteoclast formation was suppressed by adding EGCG3″Me to cocultures of osteoblasts and bone marrow cells, and LPS‐induced bone resorption was also inhibited by EGCG3″Me in calvarial organ cultures. EGCG3″Me acted on osteoblasts and suppressed prostaglandin E (PGE) production, which is critical for inflammatory bone resorption, by inhibiting the expression of COX‐2 and mPGES‐1, key enzymes for PGE synthesis. In osteoclast precursor macrophages, EGCG3″Me suppressed RANKL‐dependent differentiation into mature osteoclasts. In a mouse model of periodontitis, LPS‐induced bone resorption was suppressed by EGCG3″Me in organ culture of mouse alveolar bone, and the alveolar bone loss was further attenuated by the treatment of EGCG3″Me in the lower gingiva in vivo. EGCG3″Me may be a potential natural compound for the protection of inflammatory bone loss in periodontitis.
Alpha and Beta Error (Accumulation)
Authors: Ryffel Fabian A.
Published: November 2017

As a consequence of sampling errors, statistical significance tests sometimes yield erroneous outcomes. Specifically, two errors may occur in hypothesis tests: Alpha error occurs when the null hypothesis is erroneously rejected, and beta error occurs when the null hypothesis is wrongly retained. The present entry describes these two types of errors, examines how statistical tests are designed to avoid alpha errors, and considers how the two types of errors are related to statistical power. In addition, the problem of alpha inflation is considered and the practice of adjusting alpha to mitigate this problem is briefly discussed.
Bayesian Statistics
Authors: Vogelgesang Jens , Scharkow Michael
Published: November 2017

This entry provides a general overview of the history and the main elements of Bayesian statistics. To develop a better understanding, references are made to the similarities and differences between the Bayesian and classical approaches to statistics. The Bayesian approach to statistics allows prior knowledge to be incorporated into a statistical model. Bayes' theorem provides a mathematical rule to update the prior knowledge with new data. The results of a Bayesian analysis are characterized by a posterior distribution, which balances the prior knowledge—specified using a particular form of probability distribution—and the data likelihood.
Chicago School of Ethnography
Authors: Monteagut Lorraine E.
Published: November 2017

The Chicago School of Ethnography largely refers to research conducted between 1917 and 1942 by students of Robert E. Park and Ernest W. Burgess, sociologists at the University of Chicago who positioned urban society as the locus of social change. Ethnographers centered on face‐to‐face interactions and everyday experience in urban locales, assuming the role of “other” to produce descriptive narratives portraying a “slice of life.” Park and Burgess fostered a collective approach to interpreting their pupils' research, integrating researchers' conversations and collaborations into a consistent school of thought about urban society.
Cinema Studies
Authors: Crane Jonathan L.
Published: November 2017

Having spent more than a century asking how spectacles of mediated representation rework what it means to communicate as individuals and members of linked collectives, cinema studies can serve as a potent source of inspiration, orientation, and heuristic utility for scholars united by an allied commitment to qualitative methods. In so doing, cinema studies' overarching commitment to qualitative methods has been realized in a complex, kaleidoscopic succession of theoretical paradigms and fragmented problematics. This entry explores some of the most important paradigmatic through lines in cinema studies with reference to common theoretical issues shared by qualitative scholars across the academy.
Cluster Analysis
Authors: Mahrt Merja
Published: November 2017

Cluster analysis is a technique used to classify objects into groupings that are most different from each other, while the objects they contain are most similar to one another. A range of variants exist to determine similarity between objects and to assign objects to clusters. Cluster analysis is often used to explore structures hidden in a dataset. Usually, no clear‐cut indicators of statistical significance are available, so the researcher has to assess the validity of a cluster solution via different methods. This often involves numerous analyses using different measures of similarity or classifying algorithms. Stability and replicability of clusters as well as meaningful group comparisons indicate a good cluster solution.
Conceptualization
Authors: Schmid‐Petri Hannah
Published: November 2017

Conceptualization means the definition of abstract concepts used in social science research. In the course of conceptualization, the researcher has to define the main concepts used (conceptual definition), decide how these concepts should be measured, that is, find appropriate indicators (operational definition), and has to ensure that the measurements used are accurate and valid.
Correspondence Analysis
Authors: Schmitz Andreas
Published: November 2017

This chapter presents the basic idea of the multivariate technique “correspondence analysis,” a family of quantitative methods for the analysis of categorical data. The most common variants of correspondence analysis in practice are the bivariate case (simple correspondence analysis orCA) and the multivariate case (multiple correspondence analysis orMCA). One of the main features of this relational technique is the transformation of tabular associations into latent dimensions and graphical visualizations, so‐called “spaces.”
Critical Discourse Analysis
Authors: Bartesaghi Mariaelena , Pantelides Kate
Published: November 2017

This entry focuses on what critical discourse analysis (CDA)doesrather than is, exploring its origins, current work, and compelling features. First, by examining its potential to address the multimodality of texts, as well as intertextual and interdiscursive connections between language and social action and, second, reviewing the work of its major scholars. The entry also addresses the promise and shortcomings ofCDAas ideologically driven social research, in the hope of a productive transdisciplinary dialogue.
Critical Ethnography
Authors: Meade Melissa R.
Published: November 2017

Critical ethnography developed from poststructuralist critiques of ethnography and from engagement with critical theory within anthropology. These engagements produced a succession of feminist, postcolonial, self‐reflexive, and embodied critical ethnographies that challenged both notions of objective science and also the imperialist foundations of the discipline of anthropology. As thiscrisis of representationunfolded, critical ethnographies began to engage new methodological, philosophical, hermeneutical, and political questions, ideas, and practices.
Critical Methods
Authors: Mcdonald James
Published: November 2017

This entry traces the intellectual foundations and contemporary development of critical methods in communication research. More specifically, this entry outlines the metatheoretical assumptions and commitments of empirical critical communication research, cites exemplars of critical communication research, and summarizes the criteria through which critical communication research can be evaluated. In addition, this entry points to new directions in critical communication research and distinct intellectual traditions such as feminism, critical race theory, postcolonialism, and queer theory.
Data Transcription
Authors: Churcher Kalen M. A.
Published: November 2017

This entry provides a definition of data transcription, describes the practice of data transcription, and touches upon some of the concerns surrounding the process. Data transcription begins with establishing the unit of analysis to be studied, as well as choosing the individual to conduct the analysis. The entry addresses the process by which information is or is not included in a transcription, as well as the types of transcription that may occur. Finally, it situates data transcription within the qualitative research process and details what someone may anticipate from a transcription and the transcription process.
Deductive Reasoning
Authors: Steinberg Edo
Published: November 2017

Deductive reasoning is a method that uses rules of logic to come to a conclusion about specific cases from premises about the general population to which the case belongs. When using deductive reasoning, we state a premise about the general population. If an individual is part of that population, we conclude that the premise also applies to that individual. Competing theories see deduction as based on factual knowledge, formal rules of inference, mental models, or a combination of two or all of these.
Discriminant Analysis
Authors: Link Elena , Emde Katharina
Published: November 2017

The primary goal of discriminant analysis (DA) is to explain and predict a categorical variable by a combination of interval predictor variables. Its use is twofold: (i) DA determines predictors that separate best between cases. (ii) It assigns new cases into the existing groups according to their values regarding the independent variables. The article describes assumptions, general concepts, and evaluation criteria of discriminant analysis and gives an overview of different classification rules. Additionally, it indicates potential problems, limitations, and difficulties inherent to DA and compares the method to alternative procedures.
Dose‐Response Methodology
Authors: Arendt Florian
Published: November 2017

A dose‐response (DR) account uses an experimental methodology and tries to describe the relationship between a dose and the elicited response. There are a number of factors in media effects research which have an intrinsic ranking. One relevant variable that exists for all media is weight of exposure operationalized, for example, as the frequency or intensity. In most cases, researchers use ordinal interpretations of these variables (e.g., effects of “none,” “intermediate,” or “massive” exposure). However, statistical theory recommends that researchers should, whenever possible, use metric scaling due to its increased information. A DR account of media effects takes this recommendation seriously and experimentally manipulates the independent dose‐variable in such a way that this variable could be interpreted as metric. Nonlinear regression analysis is used to describe the functional relationship. A DR account can be used to investigate nonlinear effects in experimental media effects research (e.g., thresholds, offset).
Electrodermal Activity (EDA)
Authors: Bailey Rachel L.
Published: November 2017

Electrodermal activity is a measure of electrical activity on the surface of the skin or originating from the skin. It has been used for more than a century in psychological studies and continues to become easier to apply in a variety of contexts as technology improves. In communication research, the most popular metric is exosomatic; that is, a small current is introduced from outside the body. Of these types of metrics, conductivity is the more popular. The conductivity of the skin surface is due to how much sweat the body is producing. Researchers place sensor electrodes in areas of the body known to sweat more during times of emotional arousal or increased attention. Skin conductivity level (SCL), a tonic measure, is used to examine the emotional arousal elicited by different types of external messages over longer periods of time while skin conductivity response (SCR), a phasic measure, is used to examine the emotional arousal or potential short‐term attention (orienting) in response to a specific stimulus. The many forms of electrodermal activity measurement have been useful across psychology and communication research contexts to investigate attention and emotion for many decades. It is likely that this will continue to be so as these fields move in the direction of complexity science.
Emergent Design
Authors: Pailthorpe Brittany C.
Published: November 2017

Emergent design refers to the ability to adapt to new ideas, concepts, or findings that arise while conducting qualitative research. In contrast to more structured approaches, an emergent design welcomes unanticipated information, often adding to the richness of the data. Although the emergent characteristic is an important part ofgrounded theory, emergent design is not limited only to the data collection and analysis. An emergent approach to qualitative research is embedded within every stage from conceptualization to publication. The researcher takes cues from the data, process, or conclusions, and the whole study is a reflection of varying levels of emergent characteristics within that research process.
E
‐Prime (Software)
Authors: Taylor Paul J. , Marsh John E.
Published: November 2017

The basics components of E‐Prime are described. E‐Prime is a suite of computer programs developed by Psychology Software Tools, Inc. to allow the design and implementation of computer‐based experiments.
Eye Tracking
Authors: Cummins R. Glenn
Published: November 2017

Eye tracking serves as a useful technique for assessing visual attention to media messages or technologies (e.g., tablet computers, smart phones, handheld games) in one's visual field, as well as providing granular measures of intra‐stimulus attention allocation to specific message elements. Given the primacy of attention in the reception and processing of communication content, scholars have employed eye tracking across many media formats, technologies and contexts including print, television and online advertising, news, and health messages.
Feminism and Feminist Research
Authors: Breede Deborah Cunningham
Published: November 2017

There have been few ideologies, philosophies, and/or methodologies as hotly debated as feminism for as many centuries of human existence. Into this morass, add the academic inquiries into epistemology, the challenged notions of validity and resonance, the tensions among the theoretical and the applied, the individual and the generalizable—the often ambiguous notions surrounding the types, strengths, weaknesses, methods, and purposes of research methods—and the methodological tool box fills with political implications and other consequences that span social relationships, communication networks, cultural practices, economics, the personal, and the political. Theory, method, and for some, the scaffolding of an ethical and philosophical framework for living—a way of being—feminism, and feminist researchers, span a wide range of disciplines, genres, topics, methods, and approaches. Frequently elusive and ephemeral, contested and disputed, the aim here is to summarize current feminist research methods that inform and enrich knowledge emerging from the diffuse field of communication studies. This entry provides a basic understanding of feminist epistemology through its discussion of feminist research methods. An overview of current directions of feminist research methods is shared that envisions the future of the methodology, and examples of feminist research methods are discussed. Finally, an extensive bibliography is provided.
Fiction as Method in Qualitative Research
Authors: Marsh Jaclyn Sanders , Dyer Maria Jose Armendariz , Bubp Rebecca L. , Myers Jade
Published: November 2017

Fiction as method in qualitative research developed from the larger genre of arts‐based research. Fiction as method exists within a continuum of arts‐based methods ranging from those scholars who take aesthetic license with their work but primarily base their writing on accounts that are close to the experience; to scholars who fictionalize portions of a narrative ethnography (alter existing elements of a narrative for the purpose of providing anonymity to study participants or achieving literary aims); to scholars who write fictional accounts which are rooted in the writer's imagination in order to make a specific claim or point.
Fieldwork
Authors: Dunn Tasha R.
Published: November 2017

Originating in anthropology, fieldwork is a method through which researchers generate knowledge about social life by observing the cultural behavior, cultural knowledge, and cultural artifacts of a given group of people in their natural environment. When applied to the discipline of communication, fieldwork is used to discover patterns of communication within communities and the ways in which these patterns convey and construct social meaning.
Item Parceling
Authors: Matsunaga Masaki
Published: November 2017

Item parceling refers to a controversial practice of aggregating observed items into one or several “parcel(s)” and using thus formed parcel(s) as the indicator(s) of a latent variable. This article introduces this technique, explains briefly its merits and demerits, and discusses conditions necessary for an appropriate use. Item parceling can reduce a number of problems (e.g., random errors and nonnormality) that often present difficulty in latent variable analyses and significantly improve a model's fit to given data. Parceling may also lead to misspecification of a model, however, and thus it may cause misrepresentation of the phenomena under study. It is argued that parceling should only be used when the purpose of a study is to examine the associations among theoretical constructs (as opposed to exploring the latent factor structure underlying a set of observed scores), and the scales used can be safely assumed to be unidimensional.
MediaLab/DirectRT
Authors: Jarvis Blair
Published: November 2017

MediaLab is user‐friendly software researchers can use to create a variety of questionnaires. DirectRT is user‐friendly software capable of millisecond‐level resolution in the presentation of stimuli and collection of reaction time. Both MediaLab and DirectRT require computers running a Windows Operating System. More information and trial copies are available at
www.empirisoft.com
.
Member Checks
Authors: Arora Aarti B.
Published: November 2017

Member checks are an effective technique and procedure applied in qualitative research to ensure and establish (the) validity of a researcher's findings by seeking feedback from the participants in response to the raw data originally collected from them. Qualitative research is based on the concept that multiple realities prevail. Hence, member checks enable the researcher to share her/his initial findings with study participants (or representatives of the population studied) to ensure an appropriate representation of their culture, establish credibility for the researcher, and validate the study. Member checks can take place formally as well as informally, as and when opportunities arise in the field, and also after the interviews are transcribed. This entry highlights the positive aspects, problems, and drawbacks of member checks.
Mixed Methods Research
Authors: Onwuegbuzie Anthony J. , Gerber Hannah R. , Schamroth Abrams Sandra
Published: November 2017

Currently, there are three major research traditions: quantitative research, qualitative research, and mixed methods research. In the context of Western philosophy, the origins of these three traditions can be traced back to ancient times. Communication research also can be traced back to ancient times. Since 1960, the mixed methods research movement has gained in popularity. Unfortunately, based on previous prevalence rate studies, the use of mixed methods research approaches has not kept pace. Our own study of articles published in two highly ranked communication research journals confirmed this, with only between 4.4% and 9.7% of mixed methods research studies published in these two journals between 2010 and 2014. Thus, we provide both a framework and rationale for communication researchers to conduct mixed methods research. We contend that because rapidly growing Web 2.0 digital technologies have led to communication that is increasingly digitally mediated, the question no longer should bewhethermixed methods research techniques should be used by communication researchers buthow.
NodeXL
Authors: Himelboim Itai , Smith Marc A.
Published: November 2017

NodeXL (Network Overview, Discovery and Exploration in Excel) is a powerful and easy‐to‐use interactive network visualization and analysis tool that leverages the widely available MS Excel application as the platform for representing network data, performing advanced network analysis at the node, link, network, and cluster levels, and visual exploration of networks. The tool supports multiple social network data providers that import graph data (nodes and edge lists) into the Excel spreadsheet. Social media data sources include Twitter, Facebook, YouTube, Flickr, email, blogs, wikis, and the World Wide Web.
Qualitative Methodology
Authors: Meyen Michael
Published: November 2017

Focusing on the two core elements of qualitative methodology, that there is a high level of internal diversity and a clear distinction from quantitative methodology, this entry first addresses the role of methods in academic discussions. After that, common worldviews, perspectives, and procedures in qualitative research are presented. After portraying different qualitative approaches, the entry finally discusses the position of qualitative research in the academic discipline of communication, and future challenges.
Quantitative Methodology
Authors: Wrench Jason S.
Published: November 2017

Quantitative research methods involve a range of issues. This entry defines what is meant by the term “quantitative research” along with the term “methodology” in an effort to understand the parameters for this field of study. It then delves into the philosophical underpinnings of quantitative research methods along with the debate between significance versus hypothesis testing. The entry ends with a discussion of ten common misconceptions that people make about quantitative research methods.
Question Types
Authors: Park Byungho
Published: November 2017

This entry covers various types of questions available for communication researchers. Through the proper use of questions, one can effectively apply further analysis techniques varying from textual analysis to mathematical operations and statistical techniques. More importantly, using the wrong type of question will pose an obstacle to proper data analysis. Furthermore, certain types of questions allow the researcher to target/filter datasets according to specific subjects. Multiple filters and data targeting are now possible with the help of modern computer technology.
Reflexivity
Authors: Faulkner Sandra L. , Trotter Stormy P.
Published: November 2017

Reflexivity means being aware of and acknowledging the researcher's contribution to the construction of meanings throughout the research process and the impossibility of remaining outside of one's subject matter. It is a key concept in many qualitative methodologies, including feminist research, ethnography, and poststructural research. The degree to which and how qualitative researchers include reflexivity in their work depends on their methodological concerns.
Reliability
Authors: Krippendorff Klaus
Published: November 2017

Reliability
invokes a sense of trust in something, here in the data used in scientific research. This entry walks the reader through four conditions under which data can be relied upon, distinguishes three kinds of reliability, and describes the data required to establish the reliability of a population of data to be analyzed. It defines the

c

α‐agreement coefficient capable of assessing the reliability of data that consist of categorized or valued predefined units of analysis, sketches several extensions of this coefficient to other reliability data, and offers three standards for accepting data as sufficiently reliable to warrant subsequent analyses. It also compares several common agreement measures, associating each with the form of data to which they are applicable and the conditions under which they could serve as reliability coefficients. It ends with a precautionary note on four ways in which reported reliabilities might be called into question if not dismissed.
Replication
Authors: Koch Thomas
Published: November 2017

Replication is defined as the repetition of an original study to specify, validate, and/or extend the previous findings. Two basic types of replications can be differentiated: On the one hand, direct replications that attempt to duplicate an original procedure as closely as possible, and, on the other hand, conceptual replications that attempt to test findings of a prior study with different methods and designs. While direct replications are carried out mainly to reduce random error and to validate the reliability and conclusions of previous findings, conceptual replications also aim at extending the conclusions of an original study.
Representation/Representativeness
Authors: Thompson‐Hayes Marceline , Webb Lynne M.
Published: November 2017

Qualitative researchers attempt to accurately represent informants' voices. Accurate representation is especially challenging when studying small or difficult‐to‐access populations, such as transsexual teens. Effective strategies for achieving accurate representation include representativeness in selecting informants/messages to study, using informants' words in research reports (e.g., theme labels), and revising based on informant feedback.
SAS
(Software)
Authors: Choi Yoon Hyung
Published: November 2017

SAS is a data management and statistical analysis software that can be used for most statistical analyses that are frequently conducted by communication researchers, such as regression and ANOVAs. It can also be used for more advanced statistical analysis such as multilevel modeling and structural equation modeling. SAS is also well known for its data management capabilities and its ability to handle large amounts of data. Whereas SAS has a steeper learning curve when compared to other statistical programs, it is much more flexible and can conduct complex analyses.
Scale Development
Authors: Vooris Ryan , Clavio Galen
Published: November 2017

Psychometric scales are an important element of scientific inquiry, focusing on the measurement of psychological constructs that might otherwise be inaccessible to researchers. This entry details the process by which scales are developed in the social sciences. The concepts of reliability and validity are explored in depth, detailing the processes that scholars should undertake to ensure that planned scales capture what is intended. Following that, a detailed, step‐by‐step approach to scale development is provided, containing information on the articulation of target constructs, the analysis of sample data, and all major steps in between.
Semiotics
Authors: Westerfelhaus Robert
Published: November 2017

This entry provides an overview of the main features of the field of semiotic theory, noting its key concepts and major figures. Special attention is devoted to the dyadic and triadic conceptions of the sign, the three primary types of signs identified by Peirce, the organization of the codes that govern the use and interpretation of signs, the nature of semiotic texts, and the roles of authors and readers.
SPSS
(Software)
Authors: Frey Felix
Published: November 2017

SPSS (currently officially “IBM® SPSS® Statistics”) is a commercially distributed software suite for data management and statistical analysis and the name of the company originally developing and distributing the program. Introduced in 1968, it helped revolutionize research practices in the social sciences, enabling researchers to conduct complex statistical analyses on their own. Presently, Windows, Mac, and Linux versions of SPSS are available with major version updates released every one to two years. SPSS is a comparably easy‐to‐handle statistics program providing commonly used procedures. As such, it is widely used in academia, including in communication studies, although it is facing increasingly tough competition from more comprehensive and free open‐source software.
Triangulation
Authors: Schwarzenegger Christian
Published: November 2017

Triangulation is a metaphor rather than a precise concept. It is used to describe research strategies that systematically combine several perspectives for answering research questions. This combination can include the application of theories, methods, and data sources or perspectives of investigators. Triangulation thus aims to overcome problems of validity or biases in each stage of the research process and promises to help approach the complexity of social reality by combining various perspectives on it. All methods have strengths and weaknesses; through the combined use of multiple theories, methods, data, and investigators in the same empirical analysis, the individual strengths of each component can be capitalized. Triangulation enables researchers to approach their problems with all relevant and appropriate methods.
Unobtrusive Measures in Studying Social Media
Authors: Hsueh Hua Chen Vivian
Published: November 2017

This entry defines and describes unobtrusive measures. It highlights the advantages and disadvantages of unobtrusive measures, as well as their application in the study of social media.
Contrapuntal Analysis
Authors: Thomas Lindsey J.
Published: November 2017

This entry provides a general overview of contrapuntal analysis and describes contrapuntal analysis in relationship to the interpersonal communication theory relational dialectics theory (RDT). Contrapuntal analysis is a form of dialogic analysis, which attends to multiple cultural perspectives that can be held within a text. As an analytic companion to RDT, contrapuntal analysis illuminates the ways in which multiple value‐laden perspectives struggle for dominance in ongoing processes of meaning‐making, thus aligning contrapuntal analysis with critical discourse analysis.
Photoreceptor Interactions with Other Signals
Authors: Josse Eve‐Marie , Halliday Karen J.
Published: November 2017

The sections in this article are

Introduction

Light–Clock Connections

Light–Hormone Connections

Light and Auxin Signal Integration

The Tropisms

Light and
GA
Signal Integration

The Thermosensory Pathways
The Unique Biology of Mitochondrial Genome Instability in Plants
Authors: Mackenzie Sally A.
Published: November 2017

The sections in this article are

Introduction

Unusual and Dynamic Nature of the Plant Mitochondrial Genome

MitochondrialDNARecombination is Controlled by the Nucleus

Recombination versus Replication in Plant Mitochondrial Genome Dynamics

Nuclear Regulation of MitochondrialDNAMaintenance

Cellular and Developmental Responses to Mitochondrial Genome Rearrangement in Plants

Plant Mitochondrial Genome and its Adaptations

Acknowledgements
Cytoplasmic Male Sterilities and Mitochondrial Gene Mutations in Plants
Authors: Budar Françoise , Berthomé Richard
Published: November 2017

The sections in this article are

Introduction

The Identification and Characteristics ofCMSGenes

Current Hypotheses Concerning Sterility Mechanisms and the Role of Mitochondria in Plant Reproduction

The Restoration of Fertility by Nuclear Genes

Restorers asPPRProteins, Biochemical and Evolutionary Implications

Concluding Remarks

Acknowledgements
The Plant Cyclins
Authors: Nieuwland Jeroen , Menges Margit , Murray James A.H.
Published: November 2017

The sections in this article are

Introduction

The Plant Cyclin Family

Expression of Cyclins during the Cell Cycle

Cyclins in Plant Development

Concluding Remarks

Acknowledgments
TheUPS: An Engine that Drives the Cell Cycle
Authors: Genschik Pascal , Criqui Marie Claire
Published: November 2017

The sections in this article are

The Molecular Machinery Mediating Ubiquitin‐Dependent Proteolysis

TheSCFandAPC/C: The Two MasterE3sRegulating the Cell Cycle

Cell Cycle Targets of the Proteolytic Machinery

Conclusion
Auxin Fuels the Cell Cycle Engine during Lateral Root Initiation
Authors: Vanneste Steffen , Inzé Dirk , Beeckman Tom
Published: November 2017

The sections in this article are

Introduction

Cell Cycle Regulation during Lateral Root Development

Stemness of the Xylem‐Pole‐Associated Pericycle

Auxin Signalling during Lateral Root Initiation

Post‐Transcriptional Feedback Mechanisms on Auxin Signalling

Polar Auxin Transport Defines Lateral Root Boundaries

Cytokinins Inhibit Lateral Root Development

Brassinosteroids Regulate Auxin Transport

Light Alters Auxin Sensitivity

Conclusions and Perspectives
Controlled and Reversible Stepwise Growth of Linear Copper(I) Chains Enabled by Dynamic Ligand Scaffolds
Authors: Rivada‐Wheelaghan Orestes , Aristizábal Sandra L. , López‐Serrano Joaquín , Fayzullin Robert R. , Khusnutdinova Julia R.
Published: November 2017

Reversible stepwise chain growth in linear CuI assemblies can be achieved by using the dynamic, unsymmetric naphthyridinone‐based ligand scaffolds L1 and L2. With the same ligand scaffolds, the length of the linear copper chain can be varied from two to three and four copper atoms, and the nuclearity of the complex is easily controlled by the stepwise addition of a CuI precursor to gradually increase the chain length, or by the reductive removal of Cu atoms to decrease the chain length. This represents a rare example of a stepwise controlled chain growth in extended metal atom chains (EMACs). All complexes are formed with excellent selectivity, and the mutual transformations of the complexes of different nuclearity were found to be fast and reversible. These unusual rearrangements of metal chains of different nuclearities were achieved by a stepwise “sliding” movement of the naphthyridinone bridging fragment along the metal chain.
An analysis of the validity of retraction annotation in pubmed and the web of science
Authors: Schmidt Marion
Published: November 2017

Research on scientific misconduct relies increasingly on retractions of articles. An interdisciplinary line of research has been established that empirically assesses the phenomenon of scientific misconduct using information on retractions, and thus aims to shed light on aspects of misconduct that previously were hidden. However, comparability and interpretability of studies are to a certain extent impeded by an absence of standards in corpus delineation and by the fact that the validity of this empirical data basis has never been systematically scrutinized. This article assesses the conceptual and empirical delineation of retractions against related publication types through a comparative analysis of the coverage and consistency of retraction annotation in the databases PubMed and the Web of Science (WoS), which are both commonly used for empicial studies on retractions. The searching and linking approaches of the WoS were subsequently evaluated. The results indicate that a considerable number of PubMed retracted publications and retractions are not labeled as such in the WoS or are indistinguishable from corrections, which is highly relevant for corpus and sample strategies in the WoS.
Modelling transition phenomena of scientific coauthorship networks
Authors: Xie Z. , Ouyang Z. , Li J. , Dong E. , Yi D.
Published: November 2017

In a range of scientific coauthorship networks, transitions emerge in degree distribution, in the correlation between degree and local clustering coefficient, etc. The existence of those transitions could be regarded because of the diversity in collaboration behaviors of scientific fields. A growing geometric hypergraph built on a cluster of concentric circles is proposed to model two specific collaboration behaviors, namely the behaviors of research team leaders and those of the other team members. The model successfully predicts the transitions, as well as many common features of coauthorship networks. Particularly, it realizes a process of deriving the complex “scale‐free” property from the simple “yes/no” decisions. Moreover, it provides a reasonable explanation for the emergence of transitions with the difference of collaboration behaviors between leaders and other members. The difference emerges in the evolution of research teams, which synthetically addresses several specific factors of generating collaborations, namely the communications between research teams, academic impacts and homophily of authors.
Expression of tabersonine 16‐hydroxylase and 16‐hydroxytabersonine‐O‐methyltransferase in Catharanthus roseus hairy roots
Authors: Sun Jiayi , Zhao Le , Shao Zengyi , Shanks Jacqueline , Peebles Christie A.M.
Published: November 2017

The monoterpene indole alkaloids vindoline and catharanthine, which are exclusively synthesized in the medicinal plant Catharanthus roseus, are the two important precursors for the production of pharmaceutically important anti‐cancer medicines vinblastine and vincristine. Hairy root culture is an ideal platform for alkaloids production due to its industrial scalability, genetic and chemical stability, and availability of genetic engineering tools. However, C. roseus hairy roots do not produce vindoline due to the lack of expression of the seven‐step pathway from tabersonine to vindoline [Murata & De Luca (2015) Plant Journal, 44, 581–594]. The present study describes the genetic engineering of the first two genes tabersonine 16‐hydroxylase (T16H) and 16‐O‐methyl transferase (16OMT) in the missing vindoline pathway under the control of a glucocorticoid‐inducible promoter to direct tabersonine toward vindoline biosynthesis in C. roseus hairy roots. In two transgenic hairy roots, the induced overexpression of T16H and 16OMT resulted in the accumulation of vindoline pathway metabolites 16‐hydroxytabersonine and 16‐methoxytabersonine. The levels of root‐specific alkaloids, including lochnericine, 19‐hydroxytabersonine and hörhammericine, significantly decreased in the induced hairy roots in comparison to the uninduced control lines. This suggests tabersonine was successfully channeled to the vindoline pathway away from the roots competing pathway based on the overexpression. Interestingly, another two new metabolites were detected in the induced hairy roots and proposed to be the epoxidized‐16‐hydroxytabersonine and lochnerinine. Thus, the introduction of vindoline pathway genes in hairy roots can cause unexpected terpenoid indole alkaloids (TIA) profile alterations. Furthermore, we observed complex transcriptional changes in TIA genes and regulators detected by RT‐qPCR which highlight the tight regulation of the TIA pathway in response to T16H and 16OMT engineering in C. roseus hairy roots.
Savings from reducing low-value general surgical interventions
Authors: Malik H T , Marti J , Darzi A , Mossialos E
Published: November 2017

Background

Finding opportunities for improving efficiency is important, given the pressure on national health budgets. Identifying and reducing low-value interventions that deliver little benefit is key. A systematic literature evaluation was done to identify low-value interventions in general surgery, with further assessment of their cost.

Methods

A multiplatform method of identifying low value interventions was undertaken, including a broad literature search, a targeted database search, and opportunistic sampling. The results were then stratified by impact, assessing both frequency and cost.

Results

Seventy-one low-value general surgical procedures were identified, of which five were of high frequency and high cost (highest impact), 22 were of high cost and low frequency, 23 were of low cost and high frequency, and 21 were of low cost and low frequency (lowest impact). Highest impact interventions included inguinal hernia repair in minimally symptomatic patients, inappropriate gastroscopy, interval cholecystectomy, CT to diagnose appendicitis and routine endoscopy in those who had CT-confirmed diverticulitis. Their estimated cost was €153 383 953.

Conclusion

Low-value services place a burden on health budgets. Stopping only five high-volume, high-cost general surgical procedures could save the National Health Service €153 million per annum.
Pseudoprogression as an adverse event of glioblastoma therapy
Authors: Balaña Carmen , Capellades Jaume , Pineda Estela , Estival Anna , Puig Josep , Domenech Sira , Verger Eugenia , Pujol Teresa , Martinez‐García Maria , Oleaga Laura , Velarde JoseMaria , Mesia Carlos , Fuentes Rafael , Marruecos Jordi , Del Barco Sonia , Villà Salvador , Carrato Cristina , Gallego Oscar , Gil‐Gil Miguel , Craven‐Bartle Jordi , Alameda Francesc ,   on behalf of the GLIOCAT Group
Published: November 2017

We explored predictive factors of pseudoprogression (PsP) and its impact on prognosis in a retrospective series of uniformly treated glioblastoma patients. Patients were classified as having PsP, early progression (eP) or neither (nP). We examined potential associations with clinical, molecular, and basal imaging characteristics and compared overall survival (OS), progression‐free survival (PFS), post‐progression survival (PPS) as well as the relationship between PFS and PPS in the three groups. Of the 256 patients studied, 56 (21.9%) were classified as PsP, 70 (27.3%) as eP, and 130 (50.8%) as nP. Only MGMT methylation status was associated to PsP. MGMT methylated patients had a 3.5‐fold greater possibility of having PsP than eP (OR: 3.48; 95% CI: 1.606–7.564; P = 0.002). OS was longer for PsP than eP patients (18.9 vs. 12.3 months; P = 0.0001) but was similar for PsP and nP patients (P = 0.91). OS was shorter–though not significantly so—for PsP than nP patients (OS: 19.5 vs. 27.9 months; P = 0.63) in methylated patients. PPS was similar for patients having PsP, eP or nP (PPS: 7.2 vs. 5.4 vs. 6.7; P = 0.43). Neurological deterioration occurred in 64.3% of cases at the time they were classified as PsP and in 72.8% of cases of eP (P = 0.14). PsP confounds the evaluation of disease and does not confer a survival advantage in glioblastoma.
Resveratrol Interferes with an Early Step in the Fibrillization Pathway of Human Lysozyme and Modulates it towards Less‐Toxic, Off‐Pathway Aggregates
Authors: Kamal Zaidi Fatima , Bhat Rajiv
Published: November 2017

The effect of resveratrol, a polyphenol in red wine, on the amyloid fibril formation of human lysozyme (HuL) was investigated, towards elucidating the mechanism of resveratrol action and probing its role as a possible modulator of lysozyme aggregation and toxicity. By using a number of biophysical tools, resveratrol was observed to alter the fibrillization kinetics of HuL and inhibit its fibrillization by binding with weak to moderate affinity to the conformations populated at the early stages of the pathway with concomitant stabilization of these initial conformations. The marginal decrease in the lifetime of HuL in the presence of resveratrol by time‐resolved fluorescence measurements indicated the involvement of a static quenching mechanism in the interaction between HuL and resveratrol. Docking studies predicted the binding of resveratrol to aggregation‐prone regions in HuL, and structure and activity analyses demonstrated the retention of much of the α‐helical structure and activity of HuL in the presence of resveratrol. Resveratrol modulated the fibrillization pathway towards less‐hydrophobic, less‐toxic, off‐pathway aggregates. These results demonstrate that binding of resveratrol to HuL could protect against the formation of pathogenic, cytotoxic aggregates formed in amyloidogenic disorders, such as systemic amyloidosis; thus suggesting its potential as a plausible therapeutic agent against lysozyme amyloidosis.
PROS1 novel splice‐site variant decreases protein S expression in patients from two families with thrombotic disease
Authors: Menezes Juliane , Ventura Célia , Costa João Matos , Parreira Elsa , Romão Luísa , Gonçalves João
Published: November 2017

Key Clinical Message

Our results prove that c.1871‐14T>G is causative of type I PS deficiency, highlighting the importance of performing mRNA‐based studies in order to evaluate variants pathogenicity. We evidence the increased risk of venous thromboembolism associated with this cryptic splice‐site variant if present in patients with PS deficiency.
Polymer Amplified Enantioselectivity in the Fluorescent Recognition of Prolinol
Authors: Wang Yachen , Hu Lingling , Zhao Feng , Yu Shanshan , Tian Jun , Shi Dan , Wang Xinjing , Yu Xiaoqi , Pu Lin
Published: November 2017

A 1,1′‐bi‐2‐naphthol (BINOL)‐aldehyde‐based polymer has been synthesized that exhibits enantioselective fluorescent enhancement toward prolinol. It is found that the polymer shows greatly amplified enantioselectivity over the parent small‐molecule sensor under the same conditions. This is attributed to the photoinduced electron transfer processes between the BINOL units in the polymer chain as well as the different steric environment provided by the polymer.
Tuning the Electronic Properties of Prussian Blue Analogues for Efficient Water Oxidation Electrocatalysis: Experimental and Computational Studies
Authors: Alsaç Elif Pınar , Ülker Emine , Nune Satya Vijaya Kumar , Dede Yavuz , Karadas Ferdi
Published: November 2017

Although several Prussian Blue analogues (PBAs) have been investigated as water oxidation catalysts, the field lacks a comprehensive study that focuses on the design of the ideal PBA for this purpose. Here, members of a series of PBAs with different cyanide precursors have been investigated to study the effect of hexacyanometal groups on their electrocatalytic water oxidation activities. Cyclic voltammetric, chronoamperometric, and chronopotentiometric measurements have revealed a close relationship between the electron density of electroactive cobalt sites and electrocatalytic activity, which has also been confirmed by infrared and XPS studies. Furthermore, pH‐dependent cyclic voltammetry and computational studies have been performed to gain insight into the catalytic mechanism and electronic structure of cyanide‐based systems to identify possible intermediates and to assign the rate‐determining step of the target process.
Facet‐Specific Ligand Interactions on Ternary AgSbS2 Colloidal Quantum Dots.
Authors: Choi Hyekyoung , Kim Sungwoo , Luther Joseph M. , Kim Sang‐Wook , Shin Dongwoon , Beard Matthew C. , Jeong Sohee
Published: November 2017

Invited for the cover of this issue are the groups of Matthew C. Beard at the National Renewable Energy Laboratory (U.S.A) and Sohee Jeong at KIMM and UST, Daejeon (Republic of Korea). The image depicts solar light shining onto a quantum dot. Read the full text of the article at 10.1002/chem.201703681.