bluuebunny/crossref_metadata_2025 huggingface dataset:
Capital in General and Competition
Authors: Moseley Fred
Published: September 2018

This chapter argues that capital in general and competition are the two main levels of abstraction in Marx’s theory in Capital and that they correspond to the theories of the production of surplus value in Capital I and II and the distribution of surplus value in Capital III. The main question addressed at the level of capital in general is the production of surplus value or the determination of the total surplus value produced in the economy as a whole. The main question addressed at the level of abstraction of competition is the distribution of surplus value, or the division of the total surplus value into individual parts (first the equalization of the rate of profit across industries and then the further division of the total surplus value into commercial profit, interest, and rent).
Global Capital Accumulation and the Specificity of Latin America
Authors: Starosta Guido
Published: September 2018

This chapter addresses the theme of Latin America and its relationship with the works and ideas of Karl Marx from three different angles. First, it offers an overview of the textual evidence of the scattered passages in which Marx comments on the realities of Latin American countries. In the second place, it provides a critical review of the major controversies around Marx’s direct references to this region’s societies among Latin American Marxist scholars. Lastly, it discusses the original and creative work by Latin American authors that, taking Marx’s mature critique of political economy as presented in the Grundrisse, the 1859 Contribution and Capital as point of departure, have attempted to develop it further in order to provide a rigorous account of the specificity of capital accumulation in Latin America through the systematic categorial unfolding of the determinations of the value-form (i.e., through the worldwide uneven development of the “law of value”).
American Folk Dance and Movement
Authors: Morales Eric César
Published: September 2018

This chapter examines the moving body as a performance site for cultural values and histories in America. It encourages cross-cultural analysis of structured movement systems that include both dance and nondance, while also examining historical approaches to dance and how dance can serve practical and aesthetic purposes. Dance is a powerful vehicle for understanding folklore since populations around the world transmit their folktales, mythologies, and histories physically—in conjunction with or in lieu of oral storytelling. Attempts to define folk dance and the forms of movement that are included in relation to tradition, mostly from anthropology, are covered and the suggestion is made to develop folkloristic approaches to the subject. This essay locates current conceptualizations of folk, ethnic, and American dance, and it suggests that folkloristics can better analyze dance, specifically narrative dance, through the metaframework of choreopoetics. This is an approach grounded in methexis rather than mimesis that engages with the community-centered aspects of narrative dance, analyzing it as a holistic unit and taking into account the staging, movement, costuming, music, and unseen layers deemed important by a cultural group.
Perineuronal Nets in the Superior Olivary Complex
Authors: Morawski Markus , Sonntag Mandy
Published: September 2018

This chapter addresses perineuronal nets in the superior olivary complex, a collection of nuclei in the auditory brainstem that are involved in the processing of sound source location. Perineuronal nets, a specific form of extracellular matrix, are believed to control synaptic plasticity. They surround neuronal somata and dendrites of specific types of neurons, among which are many neurons of the superior olivary complex. The chapter describes the distribution of perineuronal nets in the superior olivary complex, focusing on controversial results and discussing underlying reasons. In addition, it considers the development of perineuronal nets and highlights differences between the main components of perineuronal nets, including the proteoglycans aggrecan, brevican, and neurocan. Finally, it introduces current concepts on the function of perineuronal nets that are specifically based on experimental data collected in the superior olivary complex and point to a contribution of perineuronal nets to synaptic transmission and neuronal excitability.
Glial Cells in the Auditory Brainstem
Authors: Milinkeviciute Giedre , Cramer Karina S.
Published: September 2018

The auditory brainstem carries out sound localization functions that require an extraordinary degree of precision. While many of the specializations needed for these functions reside in auditory neurons, additional adaptations are made possible by the functions of glial cells. Astrocytes, once thought to have mainly a supporting role in nervous system function, are now known to participate in synaptic function. In the auditory brainstem, they contribute to development of specialized synapses and to mature synaptic function. Oligodendrocytes play critical roles in regulating timing in sound localization circuitry. Microglia enter the central nervous system early in development, and also have important functions in the auditory system’s response to injury. This chapter highlights the unique functions of these non-neuronal cells in the auditory system.
Brainstem Encoding of Speech and Music Sounds in Humans
Authors: Kraus Nina , Nicol Trent
Published: September 2018

The encoding of speech and music in the auditory brainstem is available at the human scalp via the auditory-evoked frequency following response. The FFR, primarily reflecting activity in the inferior colliculus, may be evoked by speech or music stimulation and represents the combined activity of sensorimotor, cognitive, and reward centers in the brain. Its response properties, like the inferior colliculus itself, are influenced by long-term experience with sound. The transparency, individual-level reliability, and ability to gauge neural plasticity provide the researcher and clinician a powerful probe of auditory processing in the human brainstem. With it, we have learned a great deal about how mechanisms of decline, deprivation, and enrichment affect the processing of complex signals such as music and speech in the human brainstem.
The Cochlear Nuclei
Authors: Oertel Donata , Cao Xiao-Jie , Recio-Spinoso Alberto
Published: September 2018

Plasticity in neuronal circuits is essential for optimizing connections as animals develop and for adapting to injuries and aging, but it can also distort the processing, as well as compromise the conveyance of ongoing sensory information. This chapter summarizes evidence from electrophysiological studies in slices and in vivo that shows how remarkably robust signaling is in principal cells of the ventral cochlear nucleus. Even in the face of short-term plasticity, these neurons signal rapidly and with temporal precision. They can relay ongoing acoustic information from the cochlea to the brain largely independently of sounds to which they were exposed previously.
Ethics and Migration Crises
Authors: Sager Alex
Published: September 2018

The topic of ethics and migration crises has two dimensions. First, there are questions in the ethics of representation. Media, pundits, and researchers frequently describe large-scale migration as a crisis with insufficient attention to the cogency of the crisis label or the ethical issues it raises. Second, migration crises give rise to duties not to deprive people of their rights to seek safety and asylum, to protect people deprived of their rights, and to aid migrants in crisis situations. There are ways in which receiving countries are playing a role in causing migration crises through their foreign and economic policies and their attempts to restrict migration, and they instead have obligations to aid.
Decolonization, Nation Building, and Migration Crises in Southeast Asia
Authors: Bosma Ulbe
Published: September 2018

This chapter explores the mechanisms and underlying socioeconomic causes of the forced migrations that attended the decolonization of Southeast Asia. It is argued that these migrations share many characteristics with those in the wake of dissolution of the empires of the European continent after the First World War. Unlike in Europe, however, most of the displacements remained under the radar of the international refugee agencies even if they entailed harrowing conditions and human suffering. Expulsion of colonial elites to Europe, China, or Japan were rubricized as repatriations rather than international migrations, even if they involved migrants having to leave for countries they had never seen before. For most of the decolonization era that extended well into the 1970s, only international refugee diasporas were identified as migration crises. They were nonetheless just the tip of the iceberg of all the displacements that attended the decades of decolonization and nation building. It is only since the 1990s that internal displacements in Southeast Asia have become defined as migration crises as part of global turn on this subject.
The Post-Communist Identity Crisis and Queer Migration from Poland
Authors: Mole Richard C.M.
Published: September 2018

An examination of the lived experiences of Polish queer migrants in London shows how a crisis in Polish national identity following the collapse of communism in 1989 constructed nonheterosexuals as a threat to Polish norms and values, thus fueling homophobic rhetoric, violence, and discrimination and prompting queer Poles to view migration as a potential means of escape and self-realization. An analysis of the narratives of twenty-five Polish LGBQ migrants living in London revealed different modes of domestic and cross-border queer migration as well as a range of ways in which sexuality directly and indirectly influenced their decision to move abroad.
Migration, Crises, and Social Transformation in India Since the 1990s
Authors: Rao Smriti , Vakulabharanam Vamsi
Published: September 2018

Since liberalization, urban migration in India has increased in quantity, but also changed in quality, with permanent marriage migration and temporary, circular employment migration rising, even as permanent economic migration remains stagnant. This chapter understands internal migration in India to be a reordering of productive and reproductive labor that signifies a deep transformation of society. The chapter argues that this transformation is a response to three overlapping crises: an agrarian crisis, an employment crisis, and a crisis of social reproduction. These are not crises for capitalist accumulation, which they enable. Rather, they make it impossible for a majority of Indians to achieve stable, rooted livelihoods.
Effects of Climate Change on Migration Crises in Oceania
Authors: Fröhlich Christiane , Klepp Silja
Published: September 2018

So-called “climate migration” has been presented as a phenomenon causing a multitude of crises on different levels, in the worst case leading to political instability and violence. Oceania is considered a prime example for this assumed linear causality, since sea level rise is threatening to displace large numbers of people. The chapter outlines how global warming impacts migration crises in the Pacific region, focusing on securitization tendencies and critically inquiring into who defines what a crisis is. In order to understand the underlying logic of climate change securitization in the field of human mobility in Oceania, it is necessary to uncover relevant power structures which determine a) who defines what can be considered a (migration) crisis, b) how human mobility challenges preestablished ideas of citizenship, belonging and national identity, and c) how climate change figures in these topical fields and political processes.
A Gendered Analysis of the European Refugee “Crisis”
Authors: Freedman Jane
Published: September 2018

This chapter examines the experiences of women arriving in Europe in the context of the current refugee ‘crisis.’ Based on empirical research in various sites in the European Union (including Greece, Serbia, France, and Germany), the chapter explores the various sources and types of insecurity faced by women, and also the ways in which the label of ‘vulnerability’ can be used strategically to advance migration strategies. The chapter explores ways in which national and EU level policies have impacted women’s experiences of migration, and the ways in which the crisis labeling and securitization of migration to the EU have had gendered impacts on refugees themselves.
The Crisis Mentality of Russian Migration Management
Authors: Schenk Caress
Published: September 2018

Although on the periphery of the migrant-receiving world as traditionally conceived, Russia is well entrenched in the global migration crisis. Migration crisis in Russia is largely a political construction, yet it is often framed as any other type of crisis (e.g. terrorism, geopolitical conflict, economic crisis), marked by a perception of existential threat, urgent public pressure, and uncertainty. This discussion of Russian policymakers’ approach shows how routinizing crisis decision making, through repeated reactionary moves that are institutionalized into law, creates continued crisis feedback loops that reinforce short-term policy horizons and fails to address long-standing demographic and labor market problems related to migration.
Migration Flows and Migration Crisis in Southern Europe
Authors: Maddaloni Domenico , Moffa Grazia
Published: September 2018

This chapter examines the main migration flows concerning the countries of southern Europe; those are a) the immigration from developed countries b) the so-called ‘new emigration’, and c) the persistent flow of migrants, refugees, and asylum seekers. They receive a very different treatment in local political debates, which are dominated by the concern for ‘the crisis,’ (i. e., the whole range of economic, social, and political changes arising from neoliberal globalization). While discussing the current literature on these topics, the chapter shows how these flows are politically constructed for the purposes of the establishment. At the same time, the chapter highlights the relationships between these trends and the general changes affecting southern European countries.
Refugee and Romani Immigrant Populations in Barcelona
Authors: Casademont Falguera Xavier , Prieto-Flores Òscar , Feu Gelis Jordi
Published: September 2018

This chapter describes how the migration crisis is constructed in Barcelona taking into consideration the role of political, media, and social movements. The chapter compares the response to the refugee population and to the Romani immigrant population. It argues that not all constructions of refugees as crises align with negative stereotypes and rejection. In the Barcelona case, the political, social, and media actors fostered an explicit action in favor of receiving refugees and put pressure on the central government and European institutions in the EU to attend to their requests. Nevertheless, for the Romani immigrant population, actors emphasized expulsion and rejection.
The Proteomics and Metabolomics of Pain
Authors: Gomez-Varela David , Schmidt Manuela
Published: September 2018

This article critically discusses the opportunities and challenges of proteomics and metabolomics in the context of pain research and clinical practice. Painful pathologies are extremely complex and often inadequately managed. In order to significantly improve therapeutic options of pain syndromes, a system-wide analysis of the underlying mechanisms is fundamental. To this end, the article highlights the potential of firmly integrating proteomics and metabolomics into the pain researcher’s toolbox. The article introduces technological aspects of mass spectrometry and also associated stumbling blocks for its standardization in clinical research. Lastly, it outlines the path towards personalized systems pain medicine via the definition of pain phenomes—from multilayered molecular data to phenotypical profiles and integrated analysis of disease networks.
Atmospheres and the Clinical Encounter
Authors: Costa Cristina , Carmenates Sergio , Madeira Luís , Stanghellini Giovanni
Published: September 2018

Atmospheres in the clinical encounter are intersubjective phenomena experienced by the participants in that situation. In this chapter we will first unveil essential aspects of the ontology and the phenomenology of atmospheres and their role in the process of understanding. We will suggest a specific attitude during the psychiatric interview that allows the assessment of these phenomena, which we coin fragile understanding, relying on the pre-reflective domains of experience. We conclude that the training of psychiatrists in this kind of understanding might have important implications in the extension of the science of psychopathology, adding to the accuracy of diagnosis and enhancing the therapeutic dimension of the psychiatric interview.
Better Together
Authors: Pawelski James O. , Tay Louis
Published: September 2018

Positive psychology is a science, yet its subject matter overlaps significantly with that of the humanities. Differing methods of inquiry could lead to an antagonistic relationship between positive psychology and the various disciplines in the humanities, but this chapter explores the value of collaborative relations between these domains. It begins by noting ways in which the humanities have influenced—and continue to influence—positive psychology, and goes on to advocate an extensive, robust, and formal collaboration between positive psychology and the humanities. Positive psychology stands to benefit from such a collaboration through access to a rich repository of information about human experience and the quest to understand and cultivate human flourishing, through conceptual analyses and more robust and nuanced constructs, and through a new domain of positive interventions. Two extended discussions demonstrate some of the benefits that can accrue to positive psychology through collaboration with the humanities. First, a careful philosophical analysis of the “positive” in positive psychology shows how the humanities can help deepen positive psychology’s conceptual roots. Second, the presentation of a conceptual model for operationalizing the well-being effects of the humanities shows how collaboration can open up significant new programs of scientific inquiry into the roles of philosophy, history, religion, literature, music, film, and visual and performance art for understanding, enjoying, and advancing human flourishing.
Positive Psychology of Infancy and Early Childhood
Authors: Coffey John K.
Published: September 2018

This chapter provides a perspective on early childhood optimal development to identify the factors that set a foundation for flourishing across the lifespan. I examine possible links between developmental and positive psychological science to highlight how optimizing development begins in infancy. This perspective involves identifying the early childhood outcomes associated with short- and long-term flourishing. Whenever possible, these should be intrinsically motivated or even have innate roots. The chapter will have a heavy focus on the long-term outcomes because short-term (or concurrent) and long-term outcomes may not always be congruent. This perspective is not about accelerating developmental processes or advocating an unrealistic expectation of protecting children from all adversity. Accordingly, another element of this perspective involves finding ways to help children respond to adversity in healthy ways. Finally, the perspective focuses on outcomes that can be targeted for promotion and intervention as a way to increase chances of flourishing.
The First Century of the Town of Tornio
Authors: Nurmi Risto
Published: September 2018

The town of Tornio, on the border of present-day Finland and Sweden, was founded in 1621, on the order of the King of Sweden, to replace the old medieval marketplace on the estuary of the Tornio river. It was the northernmost urban site in Europe at the time. The founding and early development of the town was part of the broader trade-political process in the emerging Kingdom of Sweden during the early modern age. The original town was a small, wooden trading-post-like place, settled mostly by peasants from the surrounding countryside. This chapter provides an overview of Tornio’s urban development in its first century of existence, and discusses the development of the built environment based on the results of archaeological studies conducted since the 1960s. Lastly, the chapter addresses the early urbanization process of the inhabitants by considering their relationships with artefacts during the early phases of the town.
Monuments
Authors: Wendling Holger , Eggert Manfred K. H.
Published: September 2018

During the European Iron Age, human impact on the environment was considerable. Far from the impenetrable forests once envisaged, there had been extensive woodland clearance. A wide range of settlement types existed in intensively exploited landscapes. Sites and their hinterlands were often structured around older monuments, intentionally incorporated and integrated into local belief systems. Ancestral cemeteries, natural features, and places of resource procurement all acted as foci of collective identity, playing major roles in the mental construction of the landscape, intertwining sacred and profane. Structured settlement environs indicate an increasing importance of property rights and delimitation of social units. Social hierarchies were reproduced by architectural variability in settlements using monumental buildings as social markers, both in urban and rural contexts. The chapter also considers Iron Age exploitation of forests, which like other landscapes were heavily managed, their resources vital for constructing buildings, fortifications, and supplying the charcoal crucial for ironworking.
Warriors, War, and Weapons; or Arms, the Armed, and Armed Violence
Authors: James Simon
Published: September 2018

For many archaeologists, the warrior remains a central icon of the European Iron Age, although warfare is largely ignored by others. This chapter critiques and contextualizes the notion of the ‘warrior’ in a variety of social contexts, ranging from middle Iron Age Wessex, late Iron Age Gaul and Dacia, the Sarmatian ‘horse peoples’, to the Germanic confederations of the Roman Iron Age. Considerable archaeological evidence exists relating to armed violence: weapons and equipment, military infrastructure, and pathological data, alongside iconography and classical texts. Some European Iron Age societies developed war-making capacities far beyond the Celtic warrior stereotype, with powerful and sophisticated armies, while mercenaries mastered Greco-Roman military practices. Other societies invested heavily in weaponry, but armed violence was probably largely interpersonal rather than intercommunal. The chapter seeks to develop more sophisticated ways of understanding the use of the sword, literal and figural, in the European Iron Age.
Feasting and Commensal Rituals
Authors: Joy Jody
Published: September 2018

Feasting was an important means of social communication in Iron Age Europe and has been described as a kind of social glue—creating and recreating society by bringing people together to mark important events and ceremonies, through the communal consumption of large quantities of food and drink. This chapter examines the archaeological and literary evidence for Iron Age feasting, focusing in particular on the various social roles of the feast and the often elaborate material culture involved. A picture is built up of the varied types of feast that took place, and the types of food and drink that were consumed at them.
Regions, Groups, and Identity
Authors: Thurston T. L.
Published: September 2018

Archaeologists once viewed super-individual identity as primordial and tied to territorial boundaries, useful for describing an orderly past and creating national or ethnic genealogies. Current research ties identities not to regions, but to groups: complex cultural constructions, expressed in varied yet simultaneous manifestations of bonds with family, lineage, clan, or polity, each with multiple shifting markers. These can involve kinship, status, gender, age, occupation, shared experience, and social memory, in turn impacted by wider sociopolitical, religious, and economic concerns. Between Iron Age groups, cooperation, détente, and conflict were equally likely; trade, travel, and familiarity resulted in material and ideological co-mingling, while still preserving difference, and involved symbolic and practical novelty, as well as continuity with the past. Once, such complexities caused archaeologists to label identity research impossible or unnecessary, but its exclusion often leads to misinterpretation. Fortunately, thoughtful considerations of method, materiality, and scale have resulted in productive new approaches.
Textiles and Perishable Materials
Authors: Banck-Burgess Johanna
Published: September 2018

This chapter challenges traditional views on Iron Age dress. Recent research has greatly enhanced our understanding of how textiles were manufactured in Iron Age Europe. The variety of qualities, textures, techniques, raw materials, colours, and cuts give insights into the detailed knowledge of the craftspeople involved. Textiles used for dress, blankets, or furniture fittings were appreciated not only for their appearance, but also for the quality of the work. In everyday life, their optical qualities were used to express and signal gender, social roles and status, while the labour expended on textiles found in wealthy burials underlines both the status of the deceased and the extent of conspicuous consumption in funerary rituals—for instance, for wrapping grave furniture and goods. The chapter also looks at experimental data showing how labour-intensive textile production was, and the types of clothing and accessories found in different archaeological contexts or depicted in visual representations.
Tissue self-organization underlies morphogenesis of the notochord
Authors: Norman James , Sorrell Emma L. , Hu Yi , Siripurapu Vaishnavi , Garcia Jamie , Bagwell Jennifer , Charbonneau Patrick , Lubkin Sharon R. , Bagnat Michel
Published: September 2018

The notochord is a conserved axial structure that in vertebrates serves as a hydrostatic scaffold for embryonic axis elongation and, later on, for proper spine assembly. It consists of a core of large fluid-filled vacuolated cells surrounded by an epithelial sheath that is encased in extracellular matrix. During morphogenesis, the vacuolated cells inflate their vacuole and arrange in a stereotypical staircase pattern. We investigated the origin of this pattern and found that it can be achieved purely by simple physical principles. We are able to model the arrangement of vacuolated cells within the zebrafish notochord using a physical model composed of silicone tubes and water-absorbing polymer beads. The biological structure and the physical model can be accurately described by the theory developed for the packing of spheres and foams in cylinders. Our experiments with physical models and numerical simulations generated several predictions on key features of notochord organization that we documented and tested experimentally in zebrafish. Altogether, our data reveal that the organization of the vertebrate notochord is governed by the density of the osmotically swelling vacuolated cells and the aspect ratio of the notochord rod. We therefore conclude that self-organization underlies morphogenesis of the vertebrate notochord.

This article is part of the Theo Murphy meeting issue on ‘Mechanics of development’.
Mechanics of cortical folding: stress, growth and stability
Authors: Garcia K. E. , Kroenke C. D. , Bayly P. V.
Published: September 2018

Cortical folding, or gyrification, coincides with several important developmental processes. The folded shape of the human brain allows the cerebral cortex, the thin outer layer of neurons and their associated projections, to attain a large surface area relative to brain volume. Abnormal cortical folding has been associated with severe neurological, cognitive and behavioural disorders, such as epilepsy, autism and schizophrenia. However, despite decades of study, the mechanical forces that lead to cortical folding remain incompletely understood. Leading hypotheses have focused on the roles of (i) tangential growth of the outer cortex, (ii) spatio-temporal patterns in the birth and migration of neurons, and (iii) internal tension in axons. Recent experimental studies have illuminated not only the fundamental cellular and molecular processes underlying cortical development, but also the stress state, mechanical properties and spatio-temporal patterns of growth in the developing brain. The combination of mathematical modelling and physical measurements has allowed researchers to evaluate hypothesized mechanisms of folding, to determine whether each is consistent with physical laws. This review summarizes what physical scientists have learned from models and recent experimental observations, in the context of recent neurobiological discoveries regarding cortical development. Here, we highlight evidence of a combined mechanism, in which spatio-temporal patterns bias the locations of primary folds (i), but tangential growth of the cortical plate induces mechanical instability (ii) to propagate primary and higher-order folds.

This article is part of the Theo Murphy meeting issue ‘Mechanics of development’.
Embryo movements regulate tendon mechanical property development
Authors: Pan Xuan Sabrina , Li Jiewen , Brown Edward B. , Kuo Catherine K.
Published: September 2018

Tendons transmit forces from muscles to bones to enable skeletal motility. During development, tendons begin to bear load at the onset of embryo movements. Using the chick embryo model, this study showed that altered embryo movement frequency led to changes in elastic modulus of calcaneal tendon. In particular, paralysis led to decreased modulus, whereas hypermotility led to increased modulus. Paralysis also led to reductions in activity levels of lysyl oxidase (LOX), an enzyme that we previously showed is required for cross-linking-mediated elaboration of tendon mechanical properties. Additionally, inhibition of LOX activity abrogated hypermotility-induced increases in modulus. Taken together, our findings suggest embryo movements are critical for tendon mechanical property development and implicate LOX in this process. These exciting findings expand current knowledge of how functional tendons form during development and could guide future clinical approaches to treat tendon defects associated with abnormal mechanical loadingin utero.

This article is part of the Theo Murphy meeting issue ‘Mechanics of development’.
New functions for the proprioceptive system in skeletal biology
Authors: Blecher Ronen , Heinemann-Yerushalmi Lia , Assaraf Eran , Konstantin Nitzan , Chapman Jens R. , Cope Timothy C. , Bewick Guy S. , Banks Robert W. , Zelzer Elazar
Published: September 2018

Muscle spindles and Golgi tendon organs (GTOs) are two types of sensory receptors that respond to changes in length or tension of skeletal muscles. These mechanosensors have long been known to participate in both proprioception and stretch reflex. Here, we present recent findings implicating these organs in maintenance of spine alignment as well as in realignment of fractured bones. These discoveries have been made in several mouse lines lacking functional mechanosensors in part or completely. In both studies, the absence of functional spindles and GTOs produced a more severe phenotype than that of spindles alone. Interestingly, the spinal curve phenotype, which appeared during peripubertal development, bears resemblance to the human condition adolescent idiopathic scoliosis. This similarity may contribute to the study of the disease by offering both an animal model and a clue as to its aetiology. Moreover, it raises the possibility that impaired proprioceptive signalling may be involved in the aetiology of other conditions. Overall, these new findings expand considerably the scope of involvement of proprioception in musculoskeletal development and function.

This article is part of the Theo Murphy meeting issue ‘Mechanics of development’.
The same but different: cell intercalation as a driver of tissue deformation and fluidity
Authors: Tetley Robert J. , Mao Yanlan
Published: September 2018

The ability of cells to exchange neighbours, termed intercalation, is a key feature of epithelial tissues. Intercalation is predominantly associated with tissue deformations that drive morphogenesis. More recently, however, intercalation that is not associated with large-scale tissue deformations has been described both during animal development and in mature epithelial tissues. This latter form of intercalation appears to contribute to an emerging phenomenon that we refer to as tissue fluidity—the ability of cells to exchange neighbours without changing the overall dimensions of the tissue. Here, we discuss the contribution of junctional dynamics to intercalation governing both morphogenesis and tissue fluidity. In particular, we focus on the relative roles of junctional contractility and cell–cell adhesion as the driving forces behind intercalation. These two contributors to junctional mechanics can be used to simulate cellular intercalation in mechanical computational models, to test how junctional cell behaviours might regulate tissue fluidity and contribute to the maintenance of tissue integrity and the onset of disease.

This article is part of the Theo Murphy meeting issue ‘Mechanics of development’.
Three-dimensional microscopy and image analysis methodology for mapping and quantification of nuclear positions in tissues with approximate cylindrical geometry
Authors: Campinho Pedro , Lamperti Paola , Boselli Francesco , Vermot Julien
Published: September 2018

Organogenesis involves extensive and dynamic changes of tissue shape during development. It is associated with complex morphogenetic events that require enormous tissue plasticity and generate a large variety of transient three-dimensional geometries that are achieved by global tissue responses. Nevertheless, such global responses are driven by tight spatio-temporal regulation of the behaviours of individual cells composing these tissues. Therefore, the development of image analysis tools that allow for extraction of quantitative data concerning individual cell behaviours is central to study tissue morphogenesis. There are many image analysis tools available that permit extraction of cell parameters. Unfortunately, the majority are developed for tissues with relatively simple geometries such as flat epithelia. Problems arise when the tissue of interest assumes a more complex three-dimensional geometry. Here, we use the endothelium of the developing zebrafish dorsal aorta as an example of a tissue with cylindrical geometry and describe the image analysis routines developed to extract quantitative data on individual cells in such tissues, as well as the image acquisition and sample preparation methodology.

This article is part of the Theo Murphy meeting issue ‘Mechanics of development’.
The mechanical impact ofcol11a2loss on joints;col11a2mutant zebrafish show changes to joint development and function, which leads to early-onset osteoarthritis
Authors: Lawrence Elizabeth A. , Kague Erika , Aggleton Jessye A. , Harniman Robert L. , Roddy Karen A. , Hammond Chrissy L.
Published: September 2018

Collagen is the major structural component of cartilage, and mutations in the genes encoding type XI collagen are associated with severe skeletal dysplasias (fibrochondrogenesis and Stickler syndrome) and early-onset osteoarthritis (OA). The impact of the lack of type XI collagen on cell behaviour and mechanical performance during skeleton development is unknown. We studied a zebrafish mutant forcol11a2and evaluated cartilage, bone development and mechanical properties to address this. We show that incol11a2mutants, type II collagen is made but is prematurely degraded in maturing cartilage and ectopically expressed in the joint. These changes are correlated with increased stiffness of both bone and cartilage; quantified using atomic force microscopy. In the mutants, the skeletal rudiment terminal region in the jaw joint is broader and the interzone smaller. These differences in shape and material properties impact on joint function and mechanical performance, which we modelled using finite element analyses. Finally, we show thatcol11a2heterozygous carriers reach adulthood but show signs of severe early-onset OA. Taken together, our data demonstrate a key role for type XI collagen in maintaining the properties of cartilage matrix; which when lost leads to alterations to cell behaviour that give rise to joint pathologies.

This article is part of the Theo Murphy meeting issue ‘Mechanics of development’.
World Influence of Infectious Diseases from Wikipedia Network Analysis
Authors: Rollin Guillaume , Lages José , Shepelyansky Dima L.
Published: September 2018

We consider the network of 5 416 537 articles of English Wikipedia extracted in 2017. Using the recent reduced Google matrix (REGOMAX) method we construct the reduced network of 230 articles (nodes) of infectious diseases and 195 articles of world countries. This method generates the reduced directed network between all 425 nodes taking into account all direct and indirect links with pathways via the huge global network. PageRank and CheiRank algorithms are used to determine the most influential diseases with the top PageRank diseases being Tuberculosis, HIV/AIDS and Malaria. From the reduced Google matrix we determine the sensitivity of world countries to specific diseases integrating their influence over all their history including the times of ancient Egyptian mummies. The obtained results are compared with the World Health Organization (WHO) data demonstrating that the Wikipedia network analysis provides reliable results with up to about 80 percent overlap between WHO and REGOMAX analyses.
A transposable element insertion is the switch between alternative life history strategies
Authors: Woronik Alyssa , Tunström Kalle , Perry Michael W. , Neethiraj Ramprasad , Stefanescu Constanti , de la Paz Celorio-Mancera Maria , Brattström Oskar , Hill Jason , Lehmann Philipp , Käkelä Reijo , Wheat Christopher W.
Published: September 2018

Tradeoffs affect resource allocation during development and result in fitness consequences that drive the evolution of life history strategies. Yet despite their importance, we know little about the mechanisms underlying life history tradeoffs in wild populations. Many species ofColiasbutterflies exhibit an alternative life history strategy (ALHS) where females divert resources from wing pigment synthesis to reproductive and somatic development. Due to this reallocation, a wing color polymorphism is associated with the ALHS: individuals have either yellow/orange or white wings. Here we map the genetic basis of the ALHS switch inColias croceato a transposable element insertion downstream of theColiashomolog ofBarH-1, a homeobox transcription factor. Using CRISPR/Cas9 gene editing, antibody staining, and electron microscopy we find morph-specific specific expression ofBarH-1suppresses the formation of pigment granules in wing scales. Lipid and transcriptome analyses reveal physiological differences associated with the ALHS. These findings characterize a novel mechanism for a female-limited ALHS and show that the switch arises via recruitment of a transcription factor previously known for its function in cell fate determination in pigment cells of the retina.
Data indicate the importance of expert agencies in conservation policy
Authors: Evans Michael J. , Malcom Jacob W. , Li Ya-Wei
Published: September 2018

ABSTRACT

Data on the implementation of laws and policies are essential to the evaluation and improvement of governance. For conservation laws like the U.S. Endangered Species Act (ESA), such data can inform actions that may determine the persistence or extinction of species. A central but controversial part of the ESA is section 7, which requires federal agencies to conserve threatened and endangered species. One way they do this is by consulting with expert agencies for the ESA, the U.S. Fish and Wildlife Service (FWS) and the National Marine Fisheries Service (NMFS), on actions they may undertake that impact listed species. Using data from all 24,893 consultations recorded by NMFS from 2000 through 2017, we show that federal agencies misestimated the effects of their actions on listed species in 21% of consultations, relative to the conclusions reached by NMFS. In 71% of these cases the federal agency underestimated the effects of their action. Those discrepancies were particularly important for the conservation of 14 species in 22 consultations, where the agency concluded that its action would not harm a species, while NMFS determined the action would jeopardize the species’ existence. Patterns of misestimation varied among federal agencies, and some of the agencies most frequently involved in consultation also frequently misestimated their effects. Jeopardy conclusions were very rare—about 0.3% of consultations—with a few project types more likely to lead to jeopardy. These data highlight the importance of consultation with the expert agencies and reveal opportunities to make the consultation process more effective.

SIGNIFICANCE STATEMENT

The US Endangered Species Act is the strongest environmental law any nation has enacted to conserve imperiled species. However, policy debates over how the Act should be implemented continue to this day. This study provides the first comprehensive evaluation of how the National Marine Fisheries Service (NMFS) implements one of the Act’s most important conservation programs – consultations under section 7. Our results reveal novel insights into the importance of NMFS role in ensuring federal actions do not jeopardize the existence of listed species. By using data to inform policy debate, we identify approaches to implementing section 7 that would undermine the conservation of imperiled species, and those that could improve the efficiency of the program without sacrificing these protections.
The EBI2-oxysterol axis promotes the development of intestinal lymphoid structures and colitis
Authors: Wyss Annika , Raselli Tina , Schmelczer Gérard , Klinke Glynis , Perkins Nathan , Hersberger Martin , Spalinger Marianne R. , Atrott Kirstin , Lang Silvia , Frey-Wagner Isabelle , Scharl Michael , Sailer Andreas W. , Pabst Oliver , Rogler Gerhard , Misselwitz Benjamin
Published: September 2018

The gene encoding for Epstein-Barr virus-induced G-protein coupled receptor 2 (EBI2) is a risk gene for inflammatory bowel disease (IBD). Together with its oxysterol ligand 7α,25-dihydroxycholesterol, EBI2 mediates migration and differentiation of immune cells. However, the role of EBI2 in the colonic immune system remains insufficiently studied.

We found increased mRNA expression of EBI2 and oxysterol synthesizing enzymes (CH25H, CYP7B1) in the inflamed colon of patients with ulcerative colitis and mice with acute or chronic dextran sulfate sodium (DSS) colitis. Accordingly, we detected elevated extraintestinal levels of 25-hydroxylated oxysterols, including 7α,25-dihydroxycholesterol in mice with acute colonic inflammation. Knockout of EBI2 or CH25H did not affect severity of DSS colitis; however, inflammation was decreased in male EBI2-/- mice in the IL-10 colitis model.

The colonic immune system comprises mucosal lymphoid structures, which accumulate upon chronic inflammation in IL-10-deficient mice and in chronic DSS colitis. However, EBI2-/- mice formed significantly less colonic lymphoid structures at baseline and showed defects in inflammation-induced accumulation of lymphoid structures.

In summary, we report induction of the EBI2-7α,25-dihydroxycholesterol axis in colitis and a role of EBI2 for the accumulation of lymphoid tissue during homeostasis and inflammation. These data implicate the EBI2-7α,25-dihydroxycholesterol axis in IBD pathogenesis.
Endoglycan plays a role in axon guidance and neuronal migration by negatively regulating cell-cell adhesion
Authors: Baeriswyl Thomas , Dumoulin Alexandre , Schaettin Martina , Tsapara Georgia , Niederkofler Vera , Helbling Denise , Avilés Evelyn , Frei Jeannine A. , Wilson Nicole H. , Gesemann Matthias , Stoeckli Esther T.
Published: September 2018

Cell migration and axon guidance are important steps in the formation of neural circuits. Both steps depend on the interactions between cell surface receptors and molecules on cells along the pathway. In addition to cell-cell adhesion, these molecular interactions provide guidance information. The fine-tuning of cell-cell adhesion is an important aspect of cell migration, axon guidance, and synapse formation.

Here, we show that Endoglycan, a sialomucin, plays a role in axon guidance and cell migration in the central nervous system. In the absence of Endoglycan, commissural axons failed to properly navigate the midline of the spinal cord. In the developing cerebellum, a lack of Endoglycan prevented migration of Purkinje cells and resulted in a stunted growth of the cerebellar lobes. Taken together, these results support the hypothesis that Endoglycan acts as a ‘lubricant’, a negative regulator of cell-cell adhesion, in both commissural axon guidance and Purkinje cell migration.
phylogenize:correcting for phylogeny reveals genes associated with microbial distributions
Authors: Bradley Patrick H. , Pollard Katherine S.
Published: September 2018

Phylogenetic comparative methods are powerful but presently under-utilized ways to identify microbial genes underlying differences in community composition. These methods help to identify functionally important genes because they test for associations beyond those expected when related microbes occupy similar environments. We presentphylogenize, a pipeline with web, QIIME2, and R interfaces that allows researchers to perform phylogenetic regression on 16S amplicon and shotgun sequencing data and to visualize results.phylogenizeapplies broadly to both host-associated and environmental microbiomes. Using Human Microbiome Project and Earth Microbiome Project data, we show thatphylogenizedraws similar conclusions from 16S versus shotgun sequencing and reveals both known and candidate pathways associated with host colonization.

Availability

phylogenizeis available athttps://phylogenize.organdhttps://bitbucket.org/pbradz/phylogenize.

Contact

kpollard@gladstone.ucsf.edu
REC114 partner ANKRD31 controls number, timing and location of meiotic DNA breaks
Authors: Boekhout Michiel , Karasu Mehmet E. , Wang Juncheng , Acquaviva Laurent , Pratto Florencia , Brick Kevin , Eng Diana Y. , Camerini-Otero R. Daniel , Patel Dinshaw J. , Keeney Scott
Published: September 2018

Double-strand breaks (DSBs) initiate the homologous recombination that is crucial for meiotic chromosome pairing and segregation. Here we unveil mouse ANKRD31 as a lynchpin governing multiple aspects of DSB formation. Spermatocytes lacking ANKRD31 have altered DSB locations and fail to target DSBs to sex chromosomes’ pseudoautosomal regions (PAR). They also have delayed/fewer recombination sites but, paradoxically, more DSBs, suggesting DSB dysregulation. Unrepaired DSBs and pairing failures—stochastic on autosomes, nearly absolute on X and Y—cause meiotic arrest and sterility in males.Ankrd31-deficient females have reduced oocyte reserves. A crystal structure defines direct ANKRD31– REC114 molecular contacts and reveals a surprising pleckstrin homology domain in REC114.In vivo, ANKRD31 stabilizes REC114 association with the PAR and elsewhere. Our findings inform a model that ANKRD31 is a scaffold anchoring REC114 and other factors to specific genomic locations, promoting efficient and timely DSB formation but possibly also suppressing formation of clustered DSBs.