bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arabidopsis: Flower Development and Patterning
Authors: Krizek Beth A 
Published: May 2015

AbstractThe development of flowers and floral organs is directed by intricate genetic programmes, many aspects of which appear to be shared among angiosperms. Early acting genes establish floral meristem identity in flower primordia initiated at the periphery of the inflorescence meristem. Later, floral organ primordia arise at precise positions within these floral meristems and take on one of the four distinct identities (sepals, petals, stamens and carpels). The ABCE model, supported by both molecular and genetic experiments inArabidopsis, explains how a small number of regulatory genes (called floral homeotic genes or floral organ identity genes) act in different combinations to specify these different organ types. The floral organ identity genes encode transcription factors that form distinct higher order protein complexes in different regions of a flower primordium to control the expression of target genes responsible for organogenesis.Key ConceptsLateral organs produced by the shoot apical meristem during reproductive development acquire their identity as flowers through the action of floral meristem identity genes such asLEAFYandAPETALA1.The identities of each of the four organ types of a flower (sepal, petal, stamen and carpel) is conferred by a unique combination of floral organ identity gene activities, referred to as class A, B, C and E in the ABCE model.The activities of the class A, B and C genes are restricted to particular regions within a developing flower primarily, but not exclusively, through transcriptional regulation.The MADS domain transcription factors encoded by the class A, B, C and E genes form unique tetrameric transcriptional regulatory complexes in cells of each floral whorl.The transcriptional regulatory complexes formed by the A, B, C and E proteins regulate distinct sets of genes at different stages of flower development.Many aspects of the genetic programmes conferring floral meristem identity and floral organ identity are conserved among all angiosperms.
Cell Wall Biosynthesis
Authors: Kumar Manoj , Turner Simon 
Published: May 2015

Abstract

Plant cell walls encase the plant cells and provide many structural and functional roles. Cell walls are complex structures consisting mainly of polysaccharides (cellulose, hemicellulose and pectin), glycoproteins and phenolic compounds (lignin). Most plant cell wall polymers are synthesised from ‘activated’ precursors by the action of transferases. Cellulose is synthesised at the plasma membrane (PM) by a large complex moving in the plane of PM and extruding cellulose chains into the wall. The hemicelluloses are synthesised in the endomembrane system by resident glycosyl transferase enzymes and transported to the wall. These individual components are then cross‐linked and assembled into the complex matrix structure that comprises functional cell walls. Woody cell walls also contain lignin. Lignin is synthesised in the wall by oxidative coupling of individual monomeric subunits.

Key Concepts

All plant cells are encased in a multilayered cell wall.

Plant cell walls are an important renewable resource.

Plant cell walls are composed of polysaccharides (cellulose, hemicellulose and pectin), cell wall proteins and phenolic compounds.

Most of the polysaccharides are synthesised from activated precursors, NDP sugars and incorporated into the growing polymer catalysed by the action of glycosyl transferases (GTs).

Cellulose is synthesised by the cellulose synthase complex (CSC) moving in the plane of plasma membrane, extruding cellulose chains into the cell wall.

Hemi‐celluloses and pectin are synthesised and modified in the endomembrane system before being deposited into the apoplast for assembly into the cell wall.

Lignin monomers are synthesised in the cytoplasm and transported to the wall.

Laccases have an essential role in lignin formation by catalysing the oxidative coupling of the lignin monomers in the apoplast.

Cell wall composition varies greatly between cell types and can change as the cell differentiates and with the developmental stages of cells and the plant.

The cell wall has an important function in regulating how plant cells achieve their final size and shape and consequently have an essential role in regulating plant growth.
Collective Cell Migration in Tissue Building
Authors: Muñoz‐Soriano Verónica , Paricio Nuria 
Published: May 2015

Abstract

Collective cell migration (CCM) is an essential process during tissue building and morphogenesis of animal body plans, but it can also occur in pathogenic situations. A detailed study of this cell behaviour in several model systems has allowed to determine that cells move coordinately but interact differently while migrating together, thus defining several categories of collective cell movements. They are regulated by guidance signals that act as chemoattractants and allow directionality of movement and whose levels, together with the action of repulsive molecular cues, influence this movement. Besides, cells in the moving group affect each other through cell–cell interactions but they also interplay with the environment. Here, we describe the specific features of CCM and its different manifestations
in vivo
. We also discuss the potential relevance of the results obtained in the study of this cell behaviour in deciphering the molecular and cellular mechanisms underlying tumour invasion and metastasis.

Key Concepts

Cells can move either individually or collectivelly.

Collective cell migration occurs during morphogenesis of animal body plans.

Abnormal collective migration underlies pathological states such as tumour cell invasion and metastasis.

During collective cell migration, groups of cells move together directionally and in a coordinated manner.

Collective cell movements are regulated by dynamic gradients of extracellular signalling molecules, environmental geometrical constraints and intercellular communication.

Different types of collective cell movements have been defined according to the interactions among the cells in the moving cluster.

The use of
in vitro
,
in vivo
and theoretical models is contributing to understand how collective cell migration occurs.
Culture and Social Networks
Authors: Fuhse Jan A. 
Published: May 2015

Abstract
Since the early 1990s, social networks and culture are increasingly seen as intertwined and studied in conjunction. This “cultural turn” of network research is based on the relational sociology of Harrison White and others. It links classical structuralism with cultural analysis. Three approaches to the linkage of culture and social networks can be distinguished: The first traces cultural developments, for example, in science or in art, to network constellations: collective identities arise out of densely connected networks; new styles emerge at the intersection of network clusters from the combination of previously unconnected repertoires. The second approach views social networks themselves as intricately interwoven with culture. Roles in a network (e.g., kinship roles) are built on culturally available blueprints (institutions). As are relationships that varyingly adopt relationship frames such as “love” or “patronage.” Styles and collective identities develop from network constellations and shape them in turn. The third approach analyzes culture itself as a network of symbols and concepts. Their meaning lies in the relations to other concepts and symbols. Network analyses of culture have frequently analyzed the meaning of role categories and of relationship frames, thus linking the three approaches. Areas of particular interest for going forward include research on micro‐events in networks, the interplay of networks with ethnic categories and cultural differences, and the role of networks in societal fields.
Evolutionary Perspectives on Animal and Human Personality
Authors: Manson Joseph H. , Fairbanks Lynn A. 
Published: May 2015

Abstract

Among many nonhuman animals, individuals differ consistently in their response tendencies (e.g., shy vs bold) across multiple contexts. Researchers have tested evolutionary hypotheses accounting for these phenomena, and have also begun exploring evolutionary explanations for human personality variation. For evolutionary biologists, a trait's significance lies in its effects on
fitness
, that is, the lifetime reproductive success of individuals who bear the trait, including indirect effects through the reproductive success of genetic relatives. Recent evolutionary personality research has pursued several alternative theoretical lines of inquiry:
balancing selection
models explore whether optimal levels of personality traits vary across time, space, or trait frequency distribution;
mutation‐selection balance
models propose that selection for a single optimum personality configuration is undermined by mutations at multiple genetic loci; and
facultative calibration models
hold that personality trait levels are adjusted, during individual development, to other characteristics that affect social bargaining power. A promising general approach links personality variation to variation in life history strategy, that is, the allocation of effort among the competing demands of growth, somatic maintenance, mate acquisition, and parental investment. Emerging areas of research include relationships between personality variation and biological fitness in humans and other primates; the extent to which personality trait levels are adjusted based on individual condition; the degree to which situational flexibility varies among individuals; and whether proposed structural models of personality, such as the human five‐factor model (extraversion, neuroticism, agreeableness, conscientiousness, and openness to experience) are species‐typical or are affected by variable ecological and social conditions.
Global Income Inequality
Authors: Firebaugh Glenn 
Published: May 2015

Abstract
This essay describes the evolution of global income inequality over the past two‐and‐a‐half centuries, and its likely evolution during the twenty‐first century. Global income inequality—the sum of inequality within and between nations—is massive today, the legacy of uneven growth in the world's regions since the advent of the Industrial Revolution. Because incomes shot up in the West while lagging behind in Asia and Africa over most of this period, between‐nation income inequality grew dramatically, and most global income inequality now lies between nations. Economic growth remains uneven across the world's regions, but the fastest growth is occurring in populous poor regions of the world, compressing between‐nation inequality. As a result, global income inequality is currently receding, according to most (but not all) investigations of the matter. The compression of global inequality is attributable to rapid economic growth in China and India: If the rate of economic growth in China and India were the same as in the rest of the world, global income inequality would not be declining. The slow rate of economic growth in sub‐Saharan Africa, on the other hand, is retarding the decline. A high level of global income inequality is problematic in large part because it results in abject poverty for masses of people. If average income in the world continues to rise, alleviating abject poverty in the twenty‐first century, for future generations the level of global income inequality might matter much less than the level of income inequality within local communities.
Health and Social Inequality
Authors: Pescosolido Bernice A. 
Published: May 2015

Abstract
The link between social cleavages and life chances has been a mainstay of sociology, social science, and public health's contribution to understanding well‐being, morbidity, and mortality. From early classic work to the most recent studies, inequality has been associated with the incidence and prevalence of disease, access to health care, and higher‐than‐expected death rates, even for infants. Importantly, these differences have been documented for individuals, for neighborhoods, and for nations. On all of these key indicators, there is a clear gradient, whether measured by socioeconomic status (SES), education, or even social networks. Recent work has restated and expanded the impact of inequality through the Theory of Fundamental Causes and a focus on “health disparities.” The latter targets group membership by race, ethnicity, and/or gender, to name a few social characteristics. However, challenges arise from pushing our understandings of the role of inequalities further as status configurations, for example, only proxy the social interactions, social conditions, and social experiences that produce inequality. New theoretical and empirical research also suggests that incorporating biology into our understanding of how social inequality translates into poor health, unequal treatment, and premature death can be done by synthesizing new visions of sociocultural embeddedness with biological embedding into a complex systems framework for health and health care research. This integration dismisses the “old silos” and calls for increased collaborations across the sociomedical sciences, medicine, and genetics.
Implicit Attitude Measures
Authors: Mitchell Gregory , Tetlock Philip E. 
Published: May 2015

Abstract
Owing to concerns about the willingness and ability of people to report their attitudes accurately in response to direct inquiries, psychologists have developed a number of unobtrusive, or implicit, measures of attitudes. The most popular contemporary implicit measures equate spontaneous responses to stimuli with attitudes about those stimuli. Although these measures have been used to open important new lines of inquiry, they suffer from reliability and construct validity problems and administration limitations. Researchers conducting basic research on attitudes may fruitfully utilize implicit measures as part of a multipronged measurement strategy, but researchers seeking to predict behavior from attitudes should continue to rely on explicit measures of attitudes, taking care to minimize reactive bias and to formulate the attitude questions at the same level of specificity as the behavior to be predicted.
Leadership
Authors: Tecza Adrienne , Johnson Dominic 
Published: May 2015

Abstract
Historically, research on human leadership has been the sole domain of the social sciences, and has focused on the formalized role leaders have come to play in modern institutions. However, an independent yet parallel body of work has recently emerged in biology, where evolutionary theory is being used to investigate the origins and function of leader–follower dynamics in nonhuman animals. In recent years, interdisciplinary scholars in evolutionary psychology have attempted to merge these previously disparate research traditions, investigating whether the leader–follower relationships that evolved to help our species overcome challenges in the past holds insights for leadership strategies in our modern world. In this essay, we investigate the feasibility of such an interdisciplinary approach, the obstacles it faces, and the promise it holds for the future of leadership research.
Immigrant Sociocultural Adaptation, Identification, and Belonging
Authors: Mahler Sarah J. 
Published: May 2015

Abstract
For over 150 years and motivated by mass rural‐to‐urban migrations precipitated by industrialization, social scientists have been studying the experiences of newcomers into established sociocultural contexts. They rightly hypothesized that people's identifications with their social groups, their feelings of belonging in particular, might be altered in societies where the scope and scale of social life rapidly expanded well beyond the face‐to‐face relations characteristic of smaller‐scale societies. In addition, new forms of social solidarities and polarizations were swiftly emerging and taking hold. Early theorists faced the daunting task of not only chronicling these changes but also of theorizing in an age of newly forged and not yet sharpened social science analytical tools. Today the opposite is true; multiple models and almost innumerable publications compete to shed just a little more light on this complex social reality. Yet there is still room for innovation. Toward that goal I identify an approach meriting twenty‐first century focus: bridging heretofore separate approaches to understanding the experiences of immigrant versus native newcomers, that is, acculturation versus enculturation. Scholars of immigration have studied acculturation intensively—the processes of adapting to new cultural contexts by people who come to these contexts firmly established culturally from their homelands. Meanwhile, the same scholars almost completely ignore enculturation—the processes involved in learning culture and belonging that occupy infants and young children. Drawing upon advances in understanding the brain‐culture nexus, this essay argues that knowing more about enculturation can inform and improve understanding of acculturation. These concepts should form an analytical continuum examining how people come to identify and belong socially and how and why these shift in the course of life—particularly with migration.
Laccase‐Catalyzed Dimerization of Piceid, a Resveratrol Glucoside, and its Further Enzymatic Elaboration
Authors: Gavezzotti Paolo , Bertacchi Federica , Fronza Giovanni , Křen Vladimír , Monti Daniela , Riva Sergio 
Published: May 2015

AbstractThe laccase‐catalyzed oxidation of piceid, the 3‐β‐D‐glucopyranosyl derivative of the stilbenic phytoalexin resveratrol, allowed isolation of the corresponding β‐5 like trans‐dehydrodimer in good yield (45%) avoiding chromatography. This compound was then submitted to the action of a small library of commercially available hydrolases. While the cellulase from Trichoderma viride was able to fully hydrolyze the diglycosylated dimer to give the corresponding β‐5 like trans‐dehydrodimer of resveratrol, the β‐glucosidase from almonds allowed the isolation of a monoglycosylated intermediate in reasonable yield. The diastereoisomers and the enantiomers of the isolated dimeric products were separated using a semi‐preparative chiral column. The basic antioxidant properties of these new dimers have been determined.magnified image
Designer Microorganisms for Optimized Redox Cascade Reactions – Challenges and Future Perspectives
Authors: Bayer Thomas , Milker Sofia , Wiesinger Thomas , Rudroff Florian , Mihovilovic Marko. D. 
Published: May 2015

AbstractAn immense number of chemical reactions are carried out simultaneously in living cells. Nature’s optimization approach encompasses the assembly of reactions in cascades and to embed them in finely tuned metabolic networks. With the vast progress in the field of biocatalysis, man‐made cascades, especially redox cascades, have reached a degree of complexity that needs tools for improved control and optimization. Combined strategies from biocatalysis, metabolic engineering and synthetic biology lead to the establishment of artificial metabolic pathways with minimized interference with the cellular host environment. This review will focus on genetic and metabolic engineering tools for the assembly and introduction of de novo redox pathways into the host Escherichia coli and will present state of the art redox cascades performed by tailor‐made microbial cell factories.magnified image
The Significance of Ion Conduction in a Hybrid Organic–Inorganic Lead‐Iodide‐Based Perovskite Photosensitizer
Authors: Yang Tae‐Youl , Gregori Giuliano , Pellet Norman , Grätzel Michael , Maier Joachim 
Published: May 2015

AbstractThe success of perovskite solar cells has sparked enormous excitement in the photovoltaic community not only because of unexpectedly high efficiencies but also because of the future potential ascribed to such crystalline absorber materials. Far from being exhaustively studied in terms of solid‐state properties, these materials surprised by anomalies such as a huge apparent low‐frequency dielectric constant and pronounced hysteretic current–voltage behavior. Here we show that methylammonium (but also formamidinium) iodoplumbates are mixed conductors with a large fraction of ion conduction because of iodine ions. In particular, we measure and model the stoichiometric polarization caused by the mixed conduction and demonstrate that the above anomalies can be explained by the build‐up of stoichiometric gradients as a consequence of ion blocking interfaces. These findings provide insight into electrical charge transport in the hybrid organic–inorganic lead halide solar cells as well as into new possibilities of improving the photovoltaic performance by controlling the ionic disorder.
Poly(l‐lactic acid) with the organic nucleating agent N,N,N′‐tris(1H‐benzotriazole) trimesinic acid acethydrazide: Crystallization and melting behavior
Authors: Cai Yan‐Hua , Tang Ying , Zhao Li‐Sha 
Published: May 2015

ABSTRACTN,N,N′‐Tris(1H‐benzotriazole) trimesinic acid acethydrazide (BD) was synthesized from 1H‐benzotriazole acetohydrazide and trischloride to serve as an organic nucleating agent for the crystallization of poly(l‐lactic acid) (PLLA). First, the thermogravimetric analysis of BD exhibited a high thermal decomposition temperature; this indicated that BD maybe used as a heterogeneous nucleating agent of PLLA. Then, the effect of BD on the crystallization and melting behavior of PLLA was investigated through differential scanning calorimetry, depolarized light intensity measurements, and wide‐angle X‐ray diffraction. The appearance of a nonisothermal crystallization peak and increases in the glass‐transition temperature and the intensity of the diffraction peak suggested that the presence of BD accelerated the overall PLLA crystallization. Upon cooling at a rate of 1°C/min, the addition of just 0.5 wt % BD to PLLA increased the onset crystallization temperature from 101.4 to 111.3°C, and the nonisothermal crystallization enthalpy increased from 0.1 to 38.6 J/g. The isothermal crystallization behavior showed that the crystallization half‐time of PLLA with 0.5 wt % BD (PLLA/0.5% BD) decreased from 49.9 to 1.1 min at 105°C. However, the equilibrium melting point of PLLA/0.5% BD was lower than that of the pristine PLLA; this resulted from the increasing nucleating density of PLLA. The melting behavior of PLLA/0.5% BD further confirmed that BD improved the crystallization of PLLA, and the double‐melting peaks of PLLA/0.5% BD were assigned to melting–recrystallization. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42402.