Coral bleaching has impacted reefs worldwide and the predictions of near‐annual bleaching from over two decades ago have now been realized. While technology currently provides the means to predict large‐scale bleaching, predicting reef‐scale and within‐reef patterns in real‐time for all reef users is limited. In 2020, heat stress across the Great Barrier Reef underpinned the region's third bleaching event in 5 years. Here we review the heterogeneous emergence of bleaching across Heron Island reef habitats and discuss the oceanographic (...) drivers that underpinned variable bleaching emergence. We do so as a case study to highlight how reef end‐user groups who engage with coral reefs in different ways require targeted guidance for how, and when, to alter their use of coral reefs in response to bleaching events. Our case study of coral bleaching emergence demonstrates how within‐reef scale nowcasting of coral bleaching could aid the development of accessible and equitable bleaching response strategies on coral reefs. Also see the video abstract here: https://youtu.be/N9Tgb8N-vN0. (shrink)

If we are to ensure the persistence of species in an increasingly warm world, of interest is the identification of drivers that affect the ability of an organism to resist thermal stress. Underpinning any organism's capacity for resistance is a complex interplay between biological and physical factors occurring over multiple scales. Tropical coral reefs are a unique system, in that their function is dependent upon the maintenance of a coral–algal symbiosis that is directly disrupted by increases in (...) water temperature. A number of physical factors have been identified as affecting the biological responses of the coral organism under broadscale thermal anomalies. One such factor is water flow, which is capable of modulating both organismal metabolic functioning and thermal environments. Understanding the physiological and hydrodynamic drivers of organism response to thermal stress improves predictive capabilities and informs targeted management responses, thereby increasing the resilience of reefs into the future. (shrink)

Studies of how scientists select research problems suggest the process involves weighing a number of factors, including funding availability, likelihood of success versus failure, and perceived publishability of likely results, among others. In some fields, a strong personal interest in conducting science to bring about particular social and environmental outcomes plays an important role. Conservation biologists are frequently motivated by a desire that their research will contribute to improved conservation outcomes, which introduces a pair of challenging questions for managers of (...) science and scholars of policies governing science: 1) How do scientists integrate that goal into their processes of research priority evaluation, and 2) How can managers and funders of science utilize that knowledge in designing and administering funding programs? I use Q method to uncover four distinct schools of thought amongst researchers and knowledge-users about the merits of possible research priorities for coral reefs; one of the axes along which these schools of thought differ is in their interpretation of how science can and should interact with policy. The results reveal that perceived severity of reef stressors plays a role for some participants. Disciplinary training does not appear to be a major influence on research priority evaluation, but individual participants indicated professional expediency does prevent some researchers from pursuing or advocating that others pursue topics outside of that disciplinary specialty. Influences on and processes in research prioritization uncovered in this study have the potential to lead to counter-productive disciplinary path dependencies. From these results and building on outside literature, I conclude that better coordination and communication about research priorities across disciplines and with broader stakeholders – including knowledge users – could improve the research enterprise’s ability to contribute to meaningful societal and conservation goals. These findings are relevant to researchers and research administrators across disciplines that seek to conduct or fund science that is useful in addressing specific goals. (shrink)

Diving into the life of the tropical coral reefs and Amadou Hampâté Ba’s reflections on the person conjoin in this work, which is at once philosophical and poetic. The permeable parameters of philosophy, which enable thought to hover between unstable contours rather than to prioritize secure foundations, open to a porous imagination, tracing and retracing panoramic geographies and contemporary tensions of globalization and development. Porous imagination slips, glides, between archipelagos of clay rooftops and refuge dotting the Sudan and (...) the smallest of creatures, source of half the earth’s oxygen and base of the global food chain, the plankton. Concomitantly, ideational codes of nation, continent, humanity, nature, land and water interactively stretch and unwind, shaping a polymetrics of sites and an aesthetics of nourishment. In an epoch beset by the treacherous fractals of overpowering domination and luminous liberation, the morphosis of philosophy through transdisciplinary and transcultural interpretation offers new ways of listening to and retuning songs of sorrow and lament. Pp. 429-435. (shrink)

This paper aims to establish the connection between the theoretical and practical aims of the Office of the Hydrographer of the British Admiralty and Charles Darwin’s (1809–1882) work on coral reefs from 1835 to 1842. I also emphasize the consistent zoological as well as geological reasoning contained in these texts. The Office’s influences have been previously overlooked, despite the Admiralty’s interest in using coral reefs as natural instruments. I elaborate on this by introducing the work of (...) Alexander Dalrymple (1737–1808), the first hydrographer of the Admiralty and a figure who has flown under the radar of the history of coral reef theories. I show that Dalrymple introduced a unified account of coral reefs in which multiple features of the coral reefs, such as their shape, slope of the sides, ridges, channels, and elevation relative to the water, were all explained by the action of the winds and waves—and proposed that one could use these features to predict seafaring conditions around the islands. Then, I show that Darwin’s “Coral Islands” (1835) and his _Coral Reefs_ monograph (1842) spoke to these hydrographical issues and did so, at times, by way of zoological reasoning. It was, for instance, the coral behavior and the related notion of a zoological or botanical _station_ that ultimately proved the biggest blow to the Admiralty’s aim to use the coral reefs as instruments because it eroded many uniform predictions regarding the past or future of a coral reef. Connecting these themes leads us to a surprising conclusion: that Darwin’s theory of coral reefs, long a model instance of Darwin making uniform predictable inferences, was, in actuality, also his first formal encounter with something at times the entire opposite. (shrink)

Aggregation methods allow one to replace a large scale dynamical system (micro-system) by a reduced dynamical system (macro-system) governing a small number of global variables. This aggregation of variables can be performed when two time scales exist, a fast time scale and a slow time scale. Perturbation theory allows to obtain an approximated aggregated dynamical system which describes the behaviour of a few number of slow time varying variables which are constants of motion of the fast part of the micro-system. (...) Aggregation methods are applied to the case of the devastation of the great barrier reef by the starfishes. We recall the Antonelli/Kazarinoff model which implies a stable limit cycle for the corals and starfish populations. This prey-predator model describes the interactions between two species of corals and the starfish. Then, we generalize the Antonelli/Kazarinoff model to the case of two spatial patches with a fast part describing the starfish migration on the patches and the human manipulation of the communities by divers and, a slow part describing the growth and the interactions between the populations. We obtain an aggregated model governing the total coral densities on the patches and the total starfish population. This model can exhibit stable limit cycle oscillations and a Hopf bifurcation. The critical value of the bifurcation parameter is expressed in terms of the proportions of coral species and starfish on the two patches. This implies for example that rather than random killing of starfish by the Australian military, it may be better to send teams of divers to outbreaking reefs when they first occur who will then manipulate the community structure to increase protection. (shrink)

Coral reefs provide substantial benefits to humans by generating biologically diverse ecosystems and reducing coastal hazards. However, in recent years, mass mortality of coral reefs due to bleaching has been witnessed in the ocean worldwide. Bleaching induced by the loss of the symbiotic relationship between algae and coral is mainly attributed to climate change. Marine protected areas (MPAs) can effectively prevent local disturbances but are less likely to conserve the coral reefs from global (...) events like climate change. Other conservation and restoration methods can be useful to protect and replenish the coral population temporarily, but whether they are feasible as sustainable conservation strategies is still equivocal. Coral reef mass mortality is not an exceptional occurrence but is linked to various instances of ecological loss, serving as an S.O.S. signal of severe prolonged climate extremes. (shrink)

In this paper I challenge the notion that a healthy and resilient coral is (in all cases) a fast‐growing coral, and by inference, that a reef characterised by a fast trajectory toward high coral cover is necessarily a healthy and resilient reef. Instead, I explain how emerging evidence links fast skeletal extension rates with elevated coral‐algae (symbiotic) respiration rates, most‐often mediated by nutrient‐enlarged symbiont populations and/or rising sea temperatures. Elevated respiration rates can act to reduce the (...) autotrophic capacity (photosynthesis:respiration ratio) of the symbiosis. This restricts the capacity of the coral host to build and maintain sufficient energy reserves (e.g. lipids) needed to sustain essential homeostatic functions, including sexual reproduction and biophysical stress resistance. Moreover, it explains the somewhat paradoxical scenario, whereby at the ecological instant before the reef‐building capacity of the symbiosis is lost, a reef can look visually at its best and be accreting CaCO3 at its maximum. (shrink)

Coral reefs have been challenged by the current rate and severity of environmental change that might outpace their ability to adapt and survive. Current research focuses on understanding how microbial communities and epigenetic changes separately affect phenotypes and gene expression of corals. Here, we provide the hypothesis that coral‐associated microorganisms may directly or indirectly affect the coral's phenotypic response through the modulation of its epigenome. Homologs of ankyrin‐repeat protein A and internalin B, which indirectly cause histone (...) modifications in humans, as well as Rv1988 histone methyltransferase, and the DNA methyltransferases Rv2966c, Mhy1, Mhy2, and Mhy3 found in coral‐associated bacteria indicate that there are potential host epigenome‐modifying proteins in the coral microbiome. With the ideas presented here, we suggest that microbiome manipulation may be a means to alter a coral's epigenome, which could aid the current efforts to protect coral reefs. Also see the video abstract here: https://youtu.be/CW9GbChjKM4. (shrink)

ArgumentWhat does “life” become at a moment when biological inquiry proceeds by manufacturing biological artifacts and systems? In this article, I juxtapose two radically different communities, synthetic biologists and Hyperbolic Crochet Coral Reef crafters (HCCR). Synthetic biology is a decade-old research initiative that seeks to merge biology with engineering and experimental research with manufacture. The HCCR is a distributed venture of three thousand craftspeople who cooperatively fabricate a series of yarn and plastic coral reefs to draw attention (...) to the menace climate change poses to the Great Barrier and other reefs. Interpreting these two groups alongside one another, I suggest that for both, manufacturing biological artifacts advances their understandings of biology: in a rhetorical loop, they build new biological things in order to understand the things they are making. The resulting fabrications condense scientific and folk theories about “life” and also undo “life” as a coherent analytic object. (shrink)

The diploblastic Cnidaria form one of the most ancient metazoan phyla and thus provide a useful outgroup for comparative studies of the molecular control of development in the more complex, and more often studied, triploblasts. Among cnidarians, the reef building coral Acropora is a particularly appropriate choice for study. Acropora belongs to the Anthozoa, which several lines of evidence now indicate is the basal class within the phylum Cnidaria, and has the practical advantages that its reproduction is predictable, external (...) and accessible and that the base content of its genome is not strongly biased. The Acropora system has already provided insights into ancestral linkages of homeobox genes and the evolution of the Pax genes, and has the potential to provide further new perspectives on the age, role in development, and evolution of these and other gene families. BioEssays 22:291–296, 2000. © 2000 John Wiley & Sons, Inc. (shrink)

In 1961, Lee Chin Eng jumpstarted the reef hobby, a hobby dedicated to the modeling of coral reefs in captivity, with an article in Tropical Fish Hobbyist. He illustrated the article with eight photographs; these images were meaningful to the hobbyists viewing them and they conveyed both information about the tank system and also claims about Lee's expertise. This paper examines three genres of photographs—landscapes, active, and passive portraiture—that appeared in Lee's article and how and why they have (...) proliferated in the reef hobbyist community over the last sixty years. By tracing the history of these genres, we can better understand natural knowledge producers rely on photographs to exchange knowledge and cement community identity. (shrink)

In this paper I argue that the value attributed to coral reefs drives the characterisation of evidence for their regeneration or degradation. I observe that regeneration and degradation depend on an understanding of what an ecosystem looks like when undegraded (a baseline), and that many mutually exclusive baselines can be given for any single case. Consequently, facts about ecological processes are insufficient to usefully and non-arbitrarily characterise changes to ecosystems. By examining how baselines and the value of (...) class='Hi'>reefs interact in coral and algal reef examples, I argue that considering the value of an ecosystem is a necessity when describing processes like regeneration and degradation. This connects value as studied in socio-ecological and economic research with values as discussed in the philosophy of science literature. It also explains why such a broad range of processes may be considered regenerative, including those which introduce significant novelty, as well as pointing towards ways to mediate related debates, such as those surrounding novel and ‘pristine’ ecosystems. (shrink)

A través de la lectura de David McNally y utilizando de apoyo diferentes expresiones artísticas, hacemos un mapeo de los imaginarios resultantes de entender al capital en su monstruosidad, tal y como expuso Marx en sus textos. A partir de esas premisas recorremos el concepto de «marxismo gótico» y abordamos la problemática de la violencia representada visualmente, desde las lecciones de anatomía hasta la noción de «lo gore».

Science education in the early years is vital in assisting young children to come to know about and understand the world around them. Science in Early Childhood covers the theoretical underpinnings and practical applications of teaching science in early childhood settings in way that is engaging and accessible. It is a comprehensive resource for students, as well as early childhood teachers and carers and provides up-to-date coverage of the Early Years Learning Framework. This text explores the current issues and debates (...) in early childhood science education from an Australian perspective, whilst recognising the links to international practice and research. A summary at the start of each chapter helps students identify the key themes and ideas in early science education and application boxes throughout the text illustrate how theories relate to practice. Written by experts in the field, Science in Early Childhood is essential reading for pre-service teachers. (shrink)

Start-up organisations are small companies that experience a high level of growth and considerable risk to their very survival until they evolve into stable, established companies. This situation presents a particular set of challenges in terms of corporate governance, yet research on the governance of start-ups is limited. This research paper examines and comments on the governance of start-up organisations in New Zealand. The study replicates and extends previous New Zealand-based research of boards of established companies. From the data gathered (...) from the two surveys, conclusions can be drawn as to the role and focus of boards in start-ups versus established companies. The results are consistent with a model of active ownership which identifies key differences from established companies that could improve the governance of start-ups. The results also highlight the dependence of what might constitute effective corporate governance for a start-up on the strategic context of the company and its life cycle stage. (shrink)

Companies are beginning to recognise the concept of Corporate Social Responsibility as presenting a new business model and an opportunity for building innovative forms of competitive advantage. Boards are instrumental in shaping and overseeing such strategies and active engagement around what it means to be a responsible and responsive enterprise can strengthen the Board's potential as a strategic influence on long-term value creation. Yet many companies align with Friedman's contention that adopting and practising CSR is a distraction from their core (...) obligation, which is to act in their shareholders' best interests. Based on directors' perceptions, the paper examines responses by Boards to socially related aspects of their governance role and reports on their external orientation and receptiveness toward wider social obligations. The findings suggest that these Boards hold a narrow view of their fiduciary duty, which is closer to the shareholder model than the stakeholder approach to corporate governance. (shrink)

A lo largo de los siglos XVII y XVIII se desarrollaron sucesivas reformulaciones del contrato social a partir de la propuesta hobbesiana, categorizadas hoy en día bajo el rótulo de contractualismo clásico. Dentro de tales propuestas se sostiene que fue con Rousseau con quien el contrato social alcanzó su momento de plena madurez, racionalizándose y profundizándose sus consecuencias democráticas. Así pues, el contrato social es —dentro de la filosofía política— el elemento más significativo para sustentar la teoría del Estado moderno. (...) Sin embargo, una importante consecuencia de dicha teorización es el hecho de que el naciente Estado moderno detente para sí el monopolio de la violencia. Así pues, es posible que un obscuro trasfondo de violencia se oculte tras la formulación contractualista. El artículo que sigue pretende desarrollar un análisis de la teoría del contrato social, particularmente en la formulación de Rousseau, a partir de la teoría mimética de René Girard, con el objetivo de encontrar en su obra más representativa El contrato social, rastros de la violencia mimética y el mecanismo de chivo expiatorio planteados en la teoría girardiana. (shrink)

Global concerns over environmental and social issues in agrifood value chains have increased and are reflected in a number of voluntary sustainability standards and regulatory initiatives. However, these initiatives are often based on poor knowledge of production realities, creating a disconnect between producing and consuming countries. Through narrative analysis, this paper reveals asymmetries in the responsibilities of the various actors participating in Ecuadorian banana value chains, providing clear problem- and solution-framings. Despite the broad range of actors interviewed, our analysis reveals (...) convergence in two main narratives that reflect asymmetries amongst local actors in terms of their ability to participate, ability to maintain participation, and adaptation strategies in view of changing external factors. One narrative relates to sustainability adaptations, the cost of which is not shared among all value chain actors. This is combined with a downward trend in the price of bananas and the lack of a differentiated price to account for losses and costs arising from increasing sustainability standards. Another narrative reflects a value chain structure that threatens small-farm survival. It highlights the urgency of protecting small-farm activity by enforcing national regulation and developing new market segments/models that understand small-scale producer reality. Study results show that the multitude of standards is not seen as beneficial and that downstream actors rather wish for common minimum standards to reduce business costs. Compatibility between standards and local realities should be a priority for global sustainability standards adoption. Building on the problems and solution-framings of local value chain links, we give voice to local actors, and link their perceptions to existing literature and discursive politics while contributing to social transparency and addressing the democratic deficit in agrifood value chains. (shrink)

The importance of GS for understanding Nietzsche’s philosophy cannot be overestimated. While it can be disputed whether or not modern Nietzsche scholarship started with the revaluation of GS—as the editors claim with Giorgio Colli—the work forms an important link between the early and late writings of Nietzsche and especially Z. Klassiker Auslegen—Interpreting Classics—is a series dedicated to interpreting important works of philosophy as a whole through chapters successively discussing the individual chapters of the work. The book at hand consists of (...) two introductions—one for the volume, another one discussing the genesis of the edition of GS—and eight chapters covering each of the preface, the “Prelude in... (shrink)

En el siglo XIX, médicos europeos desarrollaron estudios científicos sobre técnica vocal y su aplicación artística. Profesionales y aficionados al canto deseaban conocer estos nuevos recursos y descubrimientos sobre la fonación, la respiración y las últimas tendencias interpretativas. El objetivo de esta investigación es documentar a través de una metodología descriptiva las principales innovaciones en la técnica vocal que se presentaron en cinco tratodos españoles de canto publicados en la segunda mitad del siglo XIX. La incorporación de estos avances influyeron (...) de forma directa en la enseñanza del canto. (shrink)

This paper explores the ways in which neoliberal schooling is threatening education. We define education as the development of cognitive and imaginative capacities for understanding of and critical engagement with social reality. Education opens horizons of possibility for collective and individual life-experience and activity by exposing the one-sidedness and contradictions of ruling-value systems. Schooling, by contrast, subordinates thought and imagination to the reproduction of the ruling money-value system, narrowing horizons of possibility for collective and individual life to service to the (...) prevailing structure of power. Our paper draws on our overlapping experiences as educators, one in the university system, the other in the adult education system. In both systems, students’ life-requirement for education is subordinated to the capitalist need for compliant wage-labourers and consumers. In opposition to this instrumentalization we will present an interpretation of “real world education” as a unique form of collective work through which teachers and students construct alternatives that can serve as the guiding ideas for new projects for social and political transformation. (shrink)

Resumen La literatura universal, se encuentra poblada de arquetípicos que comparten una condición de desamparo y marginalidad, siendo la literatura realista de la segunda mitad del siglo XIX la que constata y da cuenta de su condición. En un mismo sentido, también la Biblia presenta un sinnúmero de personajes similares, marcando un punto de inflexión al llamarlo bienaventurados. Así pues, el presente estudio bíblico-literario, se centra en el arquetipo de la “viuda pobre”, sosteniendo dicha ficción literaria es una clave interpretativa (...) de la realidad, a la luz de la teoría literaria de la Estética de la Recepción. El articulo estudia la “viuda pobre” como un imaginario cultural y estableciendo la recepción de dicho imaginario en los cuentos “El Chiflón del diablo” y “El pago” del escritor chileno Baldomero Lillo, demostrando cómo el dialogo entre cultura y Biblia representa un aporte a la comprensión de determinadas ficciones literarias como categorías antropológicas.Universal literature is crowded by archetypical characters who share abandonment and marginalization conditions, being second half 19,h century realistic literature that confirms and exposes those conditions. In that sense, The Holy Bible presents a number of those characters. Resides, it highlights a turning point, hence, The Beatitudes point out: “Blessed are the poor in spirit, for theirs is the kingdom of heaven”. Thus, the following biblical-literary study, centered in the “Poor widow” archetype, aims to the establishment of literary fiction as interpretative key of reality, under Wolfgang Iser Aesthetics Reception's theory as its methodology. The objective aims to postulate “Poor Widow” as a Cultural imaginary, and finally to establish the reception of that imaginary within the stories “El Chiflón del Diablo” and “El Pago” by the chilean writer Baldomero Lillo, demonstrating that the dialog between culture and The Holy Bible represents a contribution to some literary fiction s as anthropological categories. (shrink)

Animals use their chemosensory systems to detect and discriminate among chemical cues in the environment. Remarkable progress has recently been made in our knowledge of the molecular and cellular basis of chemosensory perception in insects, based largely on studies in Drosophila. This progress has been possible due to the identification of gene families for olfactory and gustatory receptors, the use of electro‐physiological recording techniques on sensory neurons, the multitude of genetic manipulations that are available in this species, and insights from (...) several insect model systems. Recent studies show that the superfamily of chemoreceptor proteins represent the essential elements in chemosensory coding, endowing chemosensory neurons with their abilities to respond to specific sets of odorants, tastants or pheromones. Investigating how insects detect chemicals in their environment can show us how receptor protein structures relate to ligand binding, how nervous systems process complex information, and how chemosensory systems and genes evolve. BioEssays 28:23–34, 2006. © 2005 Wiley Periodicals, Inc. (shrink)

Resumen En este trabajo se realiza un análisis exploratorio sobre lo que se ha venido concibiendo como un nuevo campo del saber científico desde hace algunas décadas, nos referimos a la neuroteología. También se pretende entender hasta qué punto la filosofía naturalista contemporánea puede estar vinculada con la neuroteología -sobre todo cuando el naturalismo implica, en la mayoría de los casos, un reduccionismo que conduce al materialismo-, teniendo en conside ración que en las distintas áreas neurocientíficas tiene lugar un fisicalismo, (...) esto es, una reducción de las propiedades o procesos cognitivos a meros procesos cerebrales e interacciones neuronales, que, gracias a la tecnología, hoy pueden ser visualizados por distintos instrumentos y técnicas.In this work an exploratory analysis is carried out on what has been conceived as a new field of scientific knowledge for some decades, we refer to neurotheology. It is also intended to under- stand to what extent contemporary naturalistic philosophy can be linked to neurotheology - especially when naturalism implies, in most cases, a reductionism that leads to materialism -, taking into account that in the different neuroscientific areas it has instead a physicalism, that is, a reduction of cognitive properties or processes to mere brain processes and neural interactions, which, thanks to technology, can now be visualized by different instruments and techniques. (shrink)

La subtitulación cuenta con un gran potencial didáctico que facilita el diseño universal de aprendizaje. Mediante el análisis de percepciones con datos cuantitativos y cualitativos se persigue conocer tanto las ideas previas sobre los usos pedagógicos de la subtitulación como la percepción de los futuros profesores de idiomas de educación secundaria de su potencial como herramienta o recurso didáctico que favorezca la integración. Los resultados muestran que los docentes de lenguas de Educación Secundaria Obligatoria están familiarizados con la subtitulación como (...) consumidores, pero necesitan formación pedagógica para incluirla en su práctica docente y así, hacer la docencia más inclusiva. (shrink)

Tissues are shaped and patterned by mechanical and chemical processes. A key mechanical process is the positioning of the mitotic spindle, which determines the size and location of the daughter cells within the tissue. Recent force and position-fluctuation measurements indicate that pushing forces, mediated by the polymerization of astral microtubules against­ the cell cortex, maintain the mitotic spindle at the cell center in Caenorhabditis elegans embryos. The magnitude of the centering forces suggests that the physical limit on the accuracy and (...) precision of this centering mechanism is determined by the number of pushing microtubules rather than by thermally driven fluctuations. In cells that divide asymmetrically, anti-centering, pulling forces generated by cortically located dyneins, in conjunction with microtubule depolymerization, oppose the pushing forces to drive spindle displacements away from the center. Thus, a balance of centering pushing forces and anti-centering pulling forces localize the mitotic spindles within dividing C. elegans cells. We discuss microtubule-based mechanisms of the mitotic spindle positioning, a key mechanical process that shapes and patterns tissues. The magnitude of the centering forces indicates that the physical limit on the accuracy and precision of centering is set by the number of contributing microtubules rather than by thermally driven fluctuations. (shrink)

Tissues are shaped and patterned by mechanical and chemical processes. A key mechanical process is the positioning of the mitotic spindle, which determines the size and location of the daughter cells within the tissue. Recent force and position-fluctuation measurements indicate that pushing forces, mediated by the polymerization of astral microtubules against­ the cell cortex, maintain the mitotic spindle at the cell center in Caenorhabditis elegans embryos. The magnitude of the centering forces suggests that the physical limit on the accuracy and (...) precision of this centering mechanism is determined by the number of pushing microtubules rather than by thermally driven fluctuations. In cells that divide asymmetrically, anti-centering, pulling forces generated by cortically located dyneins, in conjunction with microtubule depolymerization, oppose the pushing forces to drive spindle displacements away from the center. Thus, a balance of centering pushing forces and anti-centering pulling forces localize the mitotic spindles within dividing C. elegans cells. We discuss microtubule-based mechanisms of the mitotic spindle positioning, a key mechanical process that shapes and patterns tissues. The magnitude of the centering forces indicates that the physical limit on the accuracy and precision of centering is set by the number of contributing microtubules rather than by thermally driven fluctuations. (shrink)

This book examines influential conceptions of sport and then analyses the interplay of challenging borderline cases with the standard definitions of sport. It is meant to inspire more thought and debate on just what sport is, how it relates to other activities and human endeavors, and what we can learn about ourselves by studying sport.