Skeletal muscle stem cells or satellite cells are responsible for muscle regeneration in the adult. Although satellite cells are highly resistant to stress, and display greater capacity to repair molecular damage than the committed progeny, their regenerative potential declines with age. During ageing, satellite cells switch to a state of permanent cell cycle arrest or senescence which prevents their activation. A recent study reveals that the senescence of satellite cell relies on defective (...) autophagy, the quality control mechanism that degrades damaged proteins and organelles. Molecular damage is generated by oxidative stress that also promotes epigenetic changes that activate the expression of master genes, in a double‐hit mechanism that ensures senescence. Importantly, genetic, and pharmacological correction of defective autophagy reverses satellite cell senescence and restores muscle regeneration in geriatric mice, with perspectives of modulating age‐related functional decline of muscle. This study provides new clues to understand stem cell and organismal ageing. (shrink)

Cellular mechanisms whereby quiescent stem cells sense tissue injury and transition to an activated state are largely unknown. Quiescent skeletal muscle stem cells (MuSCs, also called satellite cells) have elaborate, heterogeneous projections that rapidly retract in response to muscle injury. They may therefore act as direct sensors of their niche environment. Retraction is driven by a Rac‐to‐Rho GTPase activity switch that promotes downstream MuSC activation events. These and other observations lead to several hypotheses: (1) projections are (...) morphologically dynamic at quiescence, providing a surveillance function for muscle damage; (2) quiescent projection dynamics are regulated by the relative balance of Rac and Rho activities promoted by niche‐derived cues; (3) projections, particularly their associated filopodia, sense tissue damage via changes to the biomechanical properties of the niche and/or detection of signaling cues released by damaged myofibers; and (4) the dynamic nature of projections results in a population of MuSCs with heterogeneous functional properties. These concepts may extend to other types of quiescent stem cells, as well as prove useful in translational research settings. (shrink)

Cell‐based therapies for degenerative diseases of the musculature remain on the verge of feasibility. Myogenic cells are relatively abundant, accessible, and typically harbor significant proliferative potential ex vivo. However, their use for therapeutic intervention is limited due to several critical aspects of their complex biology. Recent insights based on mouse models have advanced our understanding of the molecular mechanisms controlling the function of myogenic progenitors significantly. Moreover, the discovery of atypical myogenic cell types with the ability to cross the (...) blood‐muscle barrier has opened exciting new therapeutic avenues. In this paper, we outline the major problems that are currently associated with the manipulation of myogenic cells and discuss promising strategies to overcome these obstacles. (shrink)

Among emotions, surprise has been extensively studied in psychology. In linguistics, surprise, like other emotions, has mainly been studied through the syntactic patterns involving surprise lexemes. However, little has been done so far to correlate the reaction of surprise investigated in psychological approaches and the effects of surprise on language. This cross-disciplinary volume aims to bridge the gap between emotion, cognition and language by bringing together nine contributions on surprise from different backgrounds - psychology, human-agent interaction, linguistics. Using different methods (...) at different levels of analysis, all contributors concur in defining surprise as a cognitive operation and as a component of emotion rather than as a pure emotion. Surprise results from expectations not being met and is therefore related to epistemicity. Linguistically, there does not exist an unequivocal marker of surprise. Surprise may be either described by surprise lexemes, which are often associated with figurative language, or it may be expressed by grammatical and syntactic constructions. Originally published as a special issue of Review of Cognitive Linguistics 13:2 (2015). (shrink)

Nous étudions dans cet article les différentes formes de prédication seconde détachée en position initiale dans un corpus comparable composé de textes d’économie en anglais et en français. Ce corpus a été annoté sous le logiciel Analec. L’enjeu est de montrer en quoi un même phénomène syntaxique est exploité, sur le plan discursif, de façon divergente dans chacune des deux langues. Une étude qualitative et quantitative des prédications secondes du corpus montre que la prédication seconde prend le plus souvent la (...) forme d’une participiale en –ing en anglais, où elle se spécialise dans un rôle méta-énonciatif de balise textuelle pour le lecteur, ce qui n’est pas le cas en français. (shrink)

This study presents a sociological profile of Peruvian female industrialists and some narratives of their struggle for personal independence and entrepreneurial success within the context of global restructuring and local deindustrialization. The study adopts the classical definition of woman's economic independence as a result of women's participation in the world of paid labor.

Surprise is treated as an affect in Aristotelian philosophy as well as in Cartesian philosophy. In experimental psychology, surprise is considered to be an emotion. In phenomenology, it is only addressed indirectly (Husserl, Heidegger, Levinas), with the important exception of Ricoeur and Maldiney; it is reduced to a break in cognition by cognitivists (Dennett). Only recently was it broached in linguistics, with a focus on lexico-syntactic categories. As for the expression of surprise, it has been studied in connection with evidentiality (...) in languages that encode surprise morphosyntactically. However, how surprise is encoded in languages that lack an evidential morphosyntactic system has been largely unexplored. This book provides new insights into the dynamics of surprise based on a heuristic hypothesis tested against the investigation of time, language and emotion. It is intended to arouse the interest of a multidisciplinary audience keen on crossing the disciplinary borders of phenomenology, cognitive sciences, and pragmatics. The theoretical approaches adopted in this collection of articles rely on experiments and corpus data. They advance knowledge by building on robust empirical results coming from psychology, microphenomenology, linguistics and physiology. (shrink)

Platelets have important hemostatic functions in repairing blood vessels upon tissue injury. Cytokines, growth factors, and metabolites stored in platelet α‐granules and dense granules are released upon platelet activation and clotting. Emerging evidence indicates that such platelet‐derived signaling factors are instrumental in guiding tissue regeneration. Here, we discuss the important roles of platelet‐secreted signaling factors in skeletal muscle regeneration. Chemokines secreted by platelets in the early phase after injury are needed to recruit neutrophils to injured muscles, and impeding this early (...) step of muscle regeneration exacerbates inflammation at later stages, compromises neo‐angiogenesis and the growth of newly formed myofibers, and reduces post‐injury muscle force production. Platelets also contribute to the recruitment of pro‐regenerative stromal cells from the adipose tissue, and the platelet releasate may also regulate the metabolism and proliferation of muscle satellite cells, which sustain myogenesis. Therefore, harnessing the signaling functions of platelets and the platelet secretome may provide new avenues for promoting skeletal muscle regeneration in health and disease. (shrink)

Centrosomes are the main microtubule organizing centers in animal cells. In particular during embryogenesis, they ensure faithful spindle formation and proper cell divisions. As metazoan centrosomes are eliminated during oogenesis, they have to be reassembled upon fertilization. Most metazoans use the sperm centrioles as templates for new centrosome biogenesis while the egg's cytoplasm re-prepares all components for on-going centrosome duplication in rapidly dividing embryonic cells. We discuss our knowledge and the experimental challenges to analyze zygotic centrosome reformation, which (...) requires genetic experiments to enable scrutinizing respective male and female contributions. Male and female knockout animals and mRNA injection to mimic maternal expression of centrosomal proteins could point a way to the systematic molecular dissection of the process. The most recent data suggest that timely expression of centrosome components in oocytes is the key to zygotic centrosome reformation that uses male sperm as coordinators for de novo centrosome production. Centrosome reformation at fertilization is essential for metazoan development. It requires a complicated interplay of sperm centrioles and the cytoplasm of the oocyte, which has eliminated its centrioles during oogenesis. The male centrioles launch centrosome duplication using female centrosome proteins for the first metazoan cell divisions. (shrink)

The quantization error in a fixed-size Self-Organizing Map (SOM) with unsupervised winner-take-all learning has previously been used successfully to detect, in minimal computation time, highly meaningful changes across images in medical time series and in time series of satellite images. Here, the functional properties of the quantization error in SOM are explored further to show that the metric is capable of reliably discriminating between the finest differences in local contrast intensities and contrast signs. While this capability of the QE (...) is akin to functional characteristics of a specific class of retinal ganglion cells (the so-called Y-cells) in the visual systems of the primate and the cat, the sensitivity of the QE surpasses the capacity limits of human visual detection. Here, the quantization error in the SOM is found to reliably signal changes in contrast or colour when contrast information is removed from or added to the image, but not when the amount and relative weight of contrast information is constant and only the local spatial position of contrast elements in the pattern changes. While the RGB Mean reflects coarser changes in colour or contrast well enough, the SOM-QE is shown to outperform the RGB Mean in the detection of single-pixel changes in images with up to five million pixels. This could have important implications in the context of unsupervised image learning and computational building block approaches to large sets of image data (big data). (shrink)

This book is about how big is the universe and how small are quarks, and what are the sizes of dozens of things between these two extremes. It describes the sizes of atoms and planets, quarks and galaxies, cells and sequoias. It is a romp through forty-five orders of magnitude from the smallest sub-nuclear particles we have measured, to the edge of the observed universe. It also looks at time, from the epic age of the cosmos to the fleeting (...) lifetimes of ethereal particles. It is a narrative that trips its way from stellar magnitudes to the clocks on GPS satellites, from the nearly logarithmic scales of a piano keyboard through a system of numbers invented by Archimedes and on to the measurement of the size of an atom. (shrink)

Geocentric Greek astronomers called seven heavenly bodies visible to the naked eye (sun, moon, Mercury, Venus, Mars, Jupiter, and Saturn) πλανητες—wanderers—because unlike all the other αστρα, their relative positions were constantly changing. While the Romans changed the Greek names of the individual planets to those still in use, they retained the generic name, which now occurs in many European languages. In acentric modern astronomy a planet is a satellite of a star. In addition to the five actual planets known (...) to the Greeks, Earth, Uranus, and Neptune also orbit the sun, a smallish star about half the distance from the centre of the Milky Way to its outer reaches. Earth is the only planet on which life is known for certain to exist. The search is on for concrete evidence of existing or formerly existing life on Mars (Dunbar B. et al. Perseverance Mars rover. NASA. https://www.nasa.gov/perseverance. Retrieved 06/16/2021, 2021). Technology for detecting the chemical signature of life in the atmospheres of some planets of other stars may become available in the near future (Fujii Y. et al. Astrobiology 18 (6): 739–778, 2018)—proving a point made by (Lovelock J. Gaia: A new look at life on earth. Oxford University Press, New York, 1979) that life is a whole-planet phenomenon. That is, the Earth does not just harbour or support life; it has a life of its own. The Earth is a living planet in relationship to which individual organisms are as ephemeral cells (Vernadsky VI. Am Sci 33:1–12, 1945). (shrink)

There is growing evidence of evolutionary genome plasticity. The evolution of repetitive DNA elements, the major components of most eukaryotic genomes, involves the amplification of various classes of mobile genetic elements, the expansion of satellite DNA, the transfer of fragments or entire organellar genomes and may have connections with viruses. In addition to various repetitive DNA elements, a plethora of large and small RNAs migrate within and between cells during individual development as well as during evolution and contribute (...) to changes of genome structure and function. Such migration of DNA and RNA molecules often results in horizontal gene transfer, thus shaping the whole genomic network of interconnected species. Here, we propose that a high evolutionary dynamism of repetitive genome components is often related to the migration/movement of DNA or RNA molecules. We speculate that the cytoplasm is probably an ideal compartment for such evolutionary experiments. (shrink)

Image segmentation in land cover regions which are overlapping in satellite imagery, is one crucial challenge. To detect true belonging of one pixel becomes a challenging problem while classifying mixed pixels in overlapping regions. In current work, we propose one new approach for image segmentation using a hybrid algorithm of K-Means and Cellular Automata algorithms. This newly implemented unsupervised model can detect cluster groups using hybrid 2-Dimensional Cellular-Automata model based on K-Means segmentation approach. This approach detects different land use (...) land cover areas in satellite imagery by existing K-Means algorithm. Since it is a discrete dynamical system, cellular automaton realizes uniform interconnecting cells containing states. In the second stage of current model, we experiment with a 2-dimensional cellular automata to rank allocations of pixels among different land-cover regions. The method is experimented on the watershed area of Ajoy river (India) and Salinas (California) data set with true class labels using two internal and four external validity indices. The segmented areas are then compared with existing FCM, DBSCAN and K-Means methods and verified with the ground truth. The statistical analysis results also show the superiority of the new method. (shrink)

The paper tries to show that an evolutionary perspective helps us to address what is called the adaptation problem, that is, the remarkable coherence, and seemingly successful design, existing between our cognitive tools and the phenomena of the material world. It argues that a fine-grained description of the structure and function of experimental techniques—as a special type amongst evolving scientific practices—is a condition for a better understanding and, ultimately, an explanation of how adaptation among the heterogeneous elements of experimental knowledge (...) is attained. Some apparently contradictory features of techniques, such as their high context-dependency and their capabilities to reproduce and diversify outside their original contexts, are addressed with the help of the concepts of technical variation and the historical entrenchment of phenomena in techniques. In order to do so, a case-study on the construction of satellite-DNA and the evolution of nucleic acid hybridization, a research project carried out by Roy J. Britten and his colleagues in the 1960s, is presented in detail. This case illustrates the close relationship existing between the evolution of techniques and the stabilization of phenomena in experimental biology. (shrink)

On 16 September 1987, the main chlorofluorocarbon-producing and -consuming countries signed the Montreal Protocol, despite the absence of a scientific consensus on the mechanisms of ozone depletion over Antarctica. We argue in this article that the rapid diffusion from late 1985 onwards of satellite images showing the Antarctic ozone hole played a significant role in this diplomatic outcome. Whereas negotiators claimed that they chose to deliberately ignore the Antarctic ozone hole during the negotiations since no theory was able yet (...) to explain it, the images still loomed large for many of the actors involved. In Western countries, the National Aeronautics and Space Administration's (NASA) satellite visualizations were diffused through the general press and television stations. Other popular and mass media outlets followed quickly. In describing the circulation and appropriation processes of these images within and beyond the scientific and negotiation arenas, we show that the ozone hole images did play an important part in ozone diplomacy in the two years leading up to the signing of the Montreal Protocol, both in the expert and diplomatic arenas and as public diplomacy tools. We conclude by encouraging scholars to engage with new visual archives and to contribute to the development of the vibrant new field of research on visual diplomacy. (shrink)

In the bygone days of U-2 spy planes and Sputnik, the only ethical issues attached to satellites seemed to involve military secrecy and national boundaries. Now, with high-powered lenses, infrared senso ry devices, ubiquitous sateIEites, and instan,t high-resolution image transmission, the communication ethics issues-like the powers of global observation-have greatly magnified. Possibly, conventional warfare has become obsolete because television networks have access to a worldwide satellite images that show troops, fleets, and fighter squadrons forming prior to attack. Civilian privacy (...) has changed drastically as well because backyard sunbathers, naturalists, couples, speeding vehicles, and naked paramours seen through bedroom windows can all be identified, photographed, and publicized without their awareness or permission. Because the power, range, fuequency, and commercialism of such space photography will increase, ethicists must survey the surveillance. Vendors in many countries now routinely sell space imagery to news outlets. This means there are at least two types of communication ethics to consider: (a) In journalism ethics, editors and producers must decide whether they will publish many types of invasive photographs, some of which may also deal with military secrecy; and (b) in new media ethics, decisions about who employs, duplicates, regulates, as well as who sells and buys satellite imagery, must be monitored and debated. (shrink)

Currently, we find ourselves in a paradigm in which we believe that accepting climate change data will lead to a kind of automatic action toward the preservation of our environment. I have argued elsewhere (Fried 2020) that this lack of civic action on climate data is significant when placed in the historical, military context of the technologies that collect this data––Earth remote sensing technologies. However, I have not yet discussed the phenomenological or moral implications of this context, which are deeply (...) interconnected. In this paper, I assert that Earth remote sensing technologies can, if we are not careful, lead us to a kind of environmental deskilling. This assertion comes in four parts. First, the military context of Earth remote sensing technologies––which collect important data on climate change––acts as a kind of stability, as defined by Don Ihde and others. Second, I invoke Sir Patrick Heelan to argue that the theoretical underpinnings of Earth systems science do not translate from military to environmental praxes as we imagine they do. Third, Hannah Arendt makes the case that a state’s trust in simplifying narratives like that of climate data, meant to create “islands” of certainty in an uncertain world, can be self-defeating. That is to say, they can silence public action. I extend these arguments through Vallor’s analysis of moral deskilling, in which she points out that an overemphasis on autonomous data collection––and trust in a kind of automated decision-making on that data––can deskill us from important questions relevant to our collective flourishing. In all of these examples, the lines between environmental and military research are blurry. (shrink)

“Stem Cells Dependently Arising and Empty” May 2021, Buddhism and Culture (a Korean-language Buddhist magazine sponsored by the Foundation for the Promotion of Korean Buddhism), Korea.

It has become customary to conceptualize the living cell as an intricate piece of machinery, different to a man-made machine only in terms of its superior complexity. This familiar understanding grounds the conviction that a cell's organization can be explained reductionistically, as well as the idea that its molecular pathways can be construed as deterministic circuits. The machine conception of the cell owes a great deal of its success to the methods traditionally used in molecular biology. However, the recent introduction (...) of novel experimental techniques capable of tracking individual molecules within cells in real time is leading to the rapid accumulation of data that are inconsistent with an engineering view of the cell. This paper examines four major domains of current research in which the challenges to the machine conception of the cell are particularly pronounced: cellular architecture, protein complexes, intracellular transport, and cellular behaviour. It argues that a new theoretical understanding of the cell is emerging from the study of these phenomena which emphasizes the dynamic, self-organizing nature of its constitution, the fluidity and plasticity of its components, and the stochasticity and non-linearity of its underlying processes. (shrink)

This photographic essay is about places that have the same names but are often worlds apart. Satellite Cities looks at the naming of settlements and suburbs primarily in Johannesburg and Cape Town, and their parallels in other parts of the world. It examines the possibility of relationships or connections between these disparate places, and their realities as sites of conflict and struggle, and of war, liberation, and reconciliation.

In this brief chapter, Lloyd sets the stage for the following three papers, most centrally, Santer et al., which discusses whether the satellite data fit with climate models. Its target is a paper by Douglass et al., which claimed that satellite and weather balloon data showed that the climate models were wrong and could not be trusted. The Santer and Wigley “Fact Sheet” gives a nontechnical summary of what is wrong with the Douglass paper, while the full story (...) is in Chap. 5, a reprint of the Santer et al. paper. The context and import of this work is discussed in Lloyd. In this introduction, Lloyd emphasizes the timeliness of this work, as climate deniers testify in Congress presently. (shrink)

Currently, we find ourselves in a paradigm in which we believe that accepting climate change data will lead to a kind of automatic action toward the preservation of our environment. I have argued elsewhere (Fried 2020) that this lack of civic action on climate data is significant when placed in the historical, military context of the technologies that collect this data––Earth remote sensing technologies. However, I have not yet discussed the phenomenological or moral implications of this context, which are deeply (...) interconnected. In this paper, I assert that Earth remote sensing technologies can, if we are not careful, lead us to a kind of environmental deskilling. This assertion comes in four parts. First, the military context of Earth remote sensing technologies––which collect important data on climate change––acts as a kind of stability, as defined by Don Ihde and others. Second, I invoke Sir Patrick Heelan to argue that the theoretical underpinnings of Earth systems science do not translate from military to environmental praxes as we imagine they do. Third, Hannah Arendt makes the case that a state’s trust in simplifying narratives like that of climate data, meant to create “islands” of certainty in an uncertain world, can be self-defeating. That is to say, they can silence public action. I extend these arguments through Vallor’s analysis of moral deskilling, in which she points out that an overemphasis on autonomous data collection––and trust in a kind of automated decision-making on that data––can deskill us from important questions relevant to our collective flourishing. In all of these examples, the lines between environmental and military research are blurry. (shrink)

Reprint of the ed. published by Viking Press, New York.

This essay traces the recent history of 3D satellite animation from its military origins to its visibility in the civic sphere. Specifically, technologies unveiled in 2004 as Google Earth first received widespread public visibility in the television coverage of the 2003 U.S. invasion of Iraq. The essay first maps the political economy of the “military-media-geotech” complex, focusing mainly on the coverage of the Iraq War as an nexus of interests. Second, the essay analyzes the aesthetic uses of 3D (...) class='Hi'>satellite animation on the news during this period, including how these imaging practices meshed with existing discourses such as the clean war, the weaponization of the civic gaze, and others. The essay concludes with thoughts regarding what these practices mean for the efficacy of the deliberative citizen, public life, and the meaning of war. (shrink)

Talk of different types of cells is commonplace in the biological sciences. We know a great deal, for example, about human muscle cells by studying the same type of cells in mice. Information about cell type is apparently largely projectible across species boundaries. But what defines cell type? Do cells come pre-packaged into different natural kinds? Philosophical attention to these questions has been extremely limited [see e.g., Wilson (Species: New Interdisciplinary Essays, pp 187–207, 1999; Genes and (...) the Agents of Life, 2005; Wilson et al. Philos Top 35(1/2):189–215, 2007)]. On the face of it, the problems we face in individuating cellular kinds resemble those biologists and philosophers of biology encountered in thinking about species: there are apparently many different (and interconnected) bases on which we might legitimately classify cells. We could, for example, focus on their developmental history (a sort of analogue to a species’ evolutionary history); or we might divide on the basis of certain structural features, functional role, location within larger systems, and so on. In this paper, I sketch an approach to cellular kinds inspired by Boyd’s Homeostatic Property Cluster Theory, applying some lessons from this application back to general questions about the nature of natural kinds. (shrink)

The paper lists all the predictions and observations of eclipses of Jupiter's satellites 1668–1678 and compares them with modern computations of the these eclipses by J. H. Lieske. We discuss Roemer's method that led to his discovery of the retardment of light and finally we shall interpret Roemer's calculations.

(Recipient of the 2020 Everett Mendelsohn Prize.) This article revisits the development of the protoplasm concept as it originally arose from critiques of the cell theory, and examines how the term “protoplasm” transformed from a botanical term of art in the 1840s to the so-called “living substance” and “the physical basis of life” two decades later. I show that there were two major shifts in biological materialism that needed to occur before protoplasm theory could be elevated to have equal status (...) with cell theory in the nineteenth century. First, I argue that biologists had to accept that life could inhere in matter alone, regardless of form. Second, I argue that in the 1840s, ideas of what formless, biological matter was capable of dramatically changed: going from a “coagulation paradigm” that had existed since Theophrastus, to a more robust conception of matter that was itself capable of movement and self-maintenance. In addition to revisiting Schleiden and Schwann’s original writings on cell theory, this article looks especially closely at Hugo von Mohl’s definition of the protoplasm concept in 1846, how it differed from his primordial utricle theory of cell structure two years earlier. This article draws on Lakoff and Johnson’s theory of “ontological metaphors” to show that the cell, primordial utricle, and protoplasm can be understood as material container, object, and substance, and that these overlapping distinctions help explain the chaotic and confusing early history of cell theory. (shrink)

While the clinical promise of much stem cell research remains largely theoretical, patients are nonetheless pursuing unproven stem cell therapies in jurisdictions around the world—a phenomenon referred to as “stem cell tourism.” These treatments are generally advertised on a direct-to-consumer basis via the Internet. Research shows portrayals of stem cell medicine on such websites are overly optimistic and the claims made are unsubstantiated by published evidence. However, anecdotal evidence suggests that parents are pursing these “treatments” for their children, despite potential (...) physical and financial risk. Physicians are in a unique position as they can be expected to be involved in, or privy to, such decisions. In this paper, we consider what duties physicians may have toward minor patients whose parents/guardians wish to engage in stem cell tourism on their behalf. We use the Canadian perspective to address the broadly relevant issues raised by this trend. (shrink)

The stunning possibility of “reprogramming” differentiated somatic cells to express a pluripotent stem cell phenotype (iPS, induced pluripotent stem cell) and the “ground state” character of pluripotency reveal fundamental features of cell fate regulation that lie beyond existing paradigms. The rarity of reprogramming events appears to contradict the robustness with which the unfathomably complex phenotype of stem cells can reliably be generated. This apparent paradox, however, is naturally explained by the rugged “epigenetic landscape” with valleys representing “preprogrammed” attractor (...) states that emerge from the dynamical constraints of the gene regulatory network. This article provides a pedagogical primer to the fundamental principles of gene regulatory networks as integrated dynamic systems and reviews recent insights in gene expression noise and fate determination, thereby offering a formal framework that may help us to understand why cell fate reprogramming events are inherently rare and yet so robust. (shrink)