While neuroscientists often characterize brain activity as representational, many philosophers have construed these accounts as just theorists’ glosses on the mechanism. Moreover, philosophical discussions commonly focus on finished accounts of explanation, not research in progress. I adopt a different perspective, considering how characterizations of neural activity as representational contributes to the development of mechanistic accounts, guiding the investigations neuroscientists pursue as they work from an initial proposal to a more detailed understanding of a mechanism. I develop one illustrative example involving (...) research on the information-processing mechanisms mammals employ in navigating their environments. This research was galvanized by the discovery in the 1970s of place cells in the hippocampus. This discovery prompted research in what the activity of these cells represents and how place representations figure in navigation. It also led to the discovery of a host of other types of neurons—grid cells, head-direction cells, boundary cells—that carry other types of spatial information and interact with place cells in the mechanism underlying spatial navigation. As I will try to make clear, the research is explicitly devoted to identifying representations and determining how they are constructed and used in an information processing mechanism. Construals of neural activity as representations are not mere glosses but are characterizations to which neuroscientists are committed in the development of their explanatory accounts. (shrink)

The comprehensive liberalisation of the electricity market at the end of the last century has initiated a dynamic development. The politically determined disjunction of the network operation from generation, commerce and distribution which broke open the value added chain concerning the business organisation is to induce competition and consequently lower prices. Thus, besides a secure electricity supply, profitability, efficiency, quality and environmental aspects constitute present aims and have led to an enormous increase of complexity in the power supply. Furthermore, the (...) imponderability and uncertainty of competition processes in a liberated market aggravate prognoses for future investment decisions. Not least the anymore rising electricity demand, the emerging of a single European power market as well as technically pushed changes in the production structure, due to the emergence of alternative forms of power generation such as wind or solar energy, biomass energy or fuel cells, account for electric networks which afford complex planning and regulation mechanisms. This article gives a survey of various requirements posed on electricity networks and concludes with a short description of solution approaches to safeguard a cost-saving and secured future electricity supply. (shrink)

"This wholeheartedly interdisciplinary book explores the possibility of domain specific cooperation between philosophy and psychology concerning questions on spatial representation. Its leitmotif is the importance of movement in concord with the workings of the body schema. Against the background of embodiment, situatedness, and Susan Hurley's notion of a ninety-degree shift it is spelled out how true, domain specific cooperation between the disciplines can be accomplished. By enriching Grush's naturalistic account of representation (emulation theory) with insights stemming from teleosemantics, the notion (...) of the body schema is clarified and connected to the notion of a nonconceptual point of view. Translating this latter notion into three key capacities allows to draw on insights from neuroscience concerning place cells, head-direction cells, and grid cells. These cell types can be mapped on our key capacities, which shows that the nonconceptual point of view already is apparent on a very low level of analysis. Elaborating on Evans's notion of a travel-based space allows to sketch an account of spatial representation underwritten by the importance of movement and emulation and helps us to grasp spatial content's special framework role. Moreover, it provides a satisfying answer to the question of how a representation of space might be built up that enables higher-level cognition, yet, stands in continuity to sensorimotor research."--Publisher's description. (shrink)

In this commentary, we highlight a difficulty for metric navigation arising from recent data with grid and place cells: the integration of piecemeal representations of space in environments with repeated boundaries. Put simply, it is unclear how place and grid cells might provide a global representation of distance when their fields appear to represent repeated boundaries within an environment. One implication of this is that the capacity for spatial inferences may be limited.

The study of spatial cognition has provided considerable insight into how animals (including humans) navigate on the horizontal plane. However, the real world is three-dimensional, having a complex topography including both horizontal and vertical features, which presents additional challenges for representation and navigation. The present article reviews the emerging behavioral and neurobiological literature on spatial cognition in non-horizontal environments. We suggest that three-dimensional spaces are represented in a quasi-planar fashion, with space in the plane of locomotion being computed separately and (...) represented differently from space in the orthogonal axis bicoded.” We argue that the mammalian spatial representation in surface-travelling animals comprises a mosaic of these locally planar fragments, rather than a fully integrated volumetric map. More generally, this may be true even for species that can move freely in all three dimensions, such as birds and fish. We outline the evidence supporting this view, together with the adaptive advantages of such a scheme. (shrink)

A common way to understand memory structures in the cognitive sciences is as a cognitive map​. Cognitive maps are representational systems organized by dimensions shared with physical space. The appeal to these maps begins literally: as an account of how spatial information is represented and used to inform spatial navigation. Invocations of cognitive maps, however, are often more ambitious; cognitive maps are meant to scale up and provide the basis for our more sophisticated memory capacities. The extension is not meant (...) to be metaphorical, but the way in which these richer mental structures are supposed to remain map-like is rarely made explicit. Here we investigate this missing link, asking: how do cognitive maps represent non-spatial information?​ We begin with a survey of foundational work on spatial cognitive maps and then provide a comparative review of alternative, non-spatial representational structures. We then turn to several cutting-edge projects that are engaged in the task of scaling up cognitive maps so as to accommodate non-spatial information: first, on the spatial-isometric approach​ , encoding content that is non-spatial but in some sense isomorphic to spatial content; second, on the ​ abstraction approach​ , encoding content that is an abstraction over first-order spatial information; and third, on the ​ embedding approach​ , embedding non-spatial information within a spatial context, a prominent example being the Method-of-Loci. Putting these cases alongside one another reveals the variety of options available for building cognitive maps, and the distinctive limitations of each. We conclude by reflecting on where these results take us in terms of understanding the place of cognitive maps in memory. (shrink)

Reinvention of the form of expression is a conceptual approach characteristic for the evolution of all arts. This research study provides one such step forward in the advancement of scientific paper, a standard form of expression in natural sciences, toward more progressive terrains. The paper adopts the form of a theatrical play where a scientific family of four attempts to find the way around a writer’s block (Act I). Their idealess sense of confinement is overcome through arts or, more specifically, (...) through scientific research implementing the aesthetics of music as its key element. The characters record compositions differing in the degrees of consonance, rhythmicity and tonality, and play them to birds to observe their vocal and behavioral responses (Act II). They note that the birdsong volume drops significantly when the piano tunes, especially the compositionally complex ones, are played to the birds and increases signifcantly when the white noise of ocean waves is played. The bird count experiment proves indirectly that the birdsong volume reduction is an auditory response of the birds to music rather than the effect of their migrating to or away from the sound source. This science with the flavor of art elevates the characters beyond the limits of their confinement and they, exalted and uplifted, gain ideas for creative research in their own disciplines of biomedical science (Act III). They relinquish the newly gained freedom in favor of embracing love for humanity that underlies medical research and return to their confinement, where they conduct, in the coda of the paper, a series of experiments that venture beyond musicology and ornithology and fall in the domains of tissue engineering and drug delivery, but also psychology (Act III). First, sparrow nests are used as templates for tissue engineering constructs, which facilitate the growth of human fibroblastic cells better than their artificial, gridded replicas. Next, the shell of an Easter egg, predominantly calcite in composition, is used with success as a drug delivery carrier. Lastly, the bird nest drawing experiment demonstrates a greater mental health of children than that of the adults, correlating with one of the overarching points of the paper, which is to present children as a model for grownups to follow rather than the other way around. Over the course of the play, the characters discuss the value of the various fusions between art and science, question the limits of human language and repeatedly go off-topic to celebrate the freeness of the creative thinking process. The play reports on real-life research methods and scientific results through a narrative, without diminishing their empirical rigor and analytical accuracy. (shrink)

Over many centuries, the homing pigeon has been selectively bred for returning home from a distant location. As a result of this strong selective pressure, homing pigeons have developed an excellent spatial navigation system. This system passes through the hippocampal formation, which shares many striking similarities to the mammalian hippocampus; there are a host of shared neuropeptides, interconnections, and its role in the storage and manipulation of spatial maps. There are some notable differences as well: there are unique connectivity patterns (...) and spatial encoding strategies. This review summarizes the comparisons between the avian and mammalian hippocampal systems, and the responses of single neurons in several general categories: location and place cells responding in specific areas, path and goal cells responding between goal locations, context-dependent cells that respond before or during a task, and pattern, grid, and boundary cells that increase firing at stable intervals. Head-direction cells, responding to a specific compass direction, are found in mammals and other birds but not to date in pigeons. By studying an animal that evolved under significant adaptive pressure to quickly develop a complex and efficient spatial memory system, we may better understand the comparative neurology of neurospatial systems, and plot new and potentially fruitful avenues of comparative research in the future. (shrink)

The acceptability of sentences in natural language is constrained not only grammaticality, but also by the relationship between what is being conveyed and such factors as context and the beliefs of interlocutors. In many languages the critical element in a sentence (its focus) must be given grammatical prominence. There are different accounts of the nature of focus marking. Some researchers treat it as the grammatical realization of a potentially arbitrary feature of universal grammar and do not provide an explicit account (...) of its origins; others have argued, however, that focus marking is a (grammaticalized) functional solution to the problem of efficiently transmitting information via a noisy channel. By adding redundancy to highlight critical elements in particular, focus protects key parts of the message from noise. If this information‐theoretic account is true, then we should expect focus‐like behavior to emerge even in non‐linguistic communication systems given sufficient noise and pressures for efficiency. We tested this in an experiment in which participants played a simple communication game in which they had to click cells on a grid to communicate one of two line figures drawn across the grid. We manipulated the noise, available time, and required effort, and measured patterns of redundancy. Because the lines in many cases overlapped, meaning that only some parts of each line could be used to distinguish it from the other, we were able to compare the extent to which effort was expended on adding redundancy to critical (non‐overlapping) and non‐critical (overlapping) parts of the message. The results supported the information‐theoretic account of focus and shed light on the emergence of information structure in language. (shrink)

Cardiovascular modelling has been a major research subject for the last decade. Different cardiac models have been developed at a cellular level as well as at the whole organ level. Most of these models are defined by a comprehensive cellular modelling using continuous formalisms or by a tissue-level modelling often based on discrete formalisms. Nevertheless, both views still suffer from difficulties that reduce their clinical applications: the first approach requires heavy computational resources while the second one is not able to (...) reproduce certain pathologies.This paper presents an original methodology trying to gather advantages from both approaches, by means of a hybrid model mixing discrete and continuous formalisms. This method has been applied to define a hybrid model of cardiac action potential propagation on a 2D grid of endocardial cells, combining cellular automata and a set of cells defined by the Beeler-Reuter model. For simulations under physiological and ischemic conditions, results show that the action potential propagation as well as electrogram reconstructions are consistent with clinical diagnosis. Finally, the advantage of the proposed approach is discussed within the frame of cardiac modelling and simulation. (shrink)

Background The first COVID-19 wave started in February 2020 in France. The influx of patients requiring emergency care and high-level technicity led healthcare professionals to fear saturation of available care. In that context, the multidisciplinary Ethics- Support Cell (EST) was created to help medical teams consider the decisions that could potentially be sources of ethical dilemmas. Objectives The primary objective was to prospectively collect information on requests for EST assistance from 23 March to 9 May 2020. The secondary aim was (...) to describe the Cell’s functions during that period. Research design This observational, real-time study of requests for Cell consultations concerned ethical dilemmas arising during a public health crisis. The EST created a grid to collect relevant information (clinical, patient’s/designated representative’s preferences and ethical principles strained by the situation), thereby assuring that each EST asked the same questions, in the same order. Participants and research context Only our university hospital’s clinicians could request EST intervention. Ethical considerations The hospital Research Ethics Committee approved this study (no. CER-2020-107). The patient, his/her family, or designated representative was informed of this ethics consultation and most met with EST members, which enabled them to express their preferences and/or opposition. Findings/results 33 requests (patients’ mean age: 80.8 years; 29 had COVID-19: 24 with dyspnea, 30 with comorbidities). 17 Emergency Department solicitations concerned ICU admission, without reference to resource constraints; others addressed therapeutic proportionality dilemmas. Discussion Intervention-request motives concerned limited resources and treatment intensity. Management revolved around three axes: the treatment option most appropriate for the patient, the feasibility of implementation, and dignified care for the patient. Conclusions COVID-19 crisis forced hospitals to envisage prioritization of ICU access. Established decision-making criteria and protocols do not enable healthcare professionals to escape ethical dilemmas. That acknowledgement highlights ethical risks, enhances the added-value of nursing and encourages all players to be vigilant to pursue collective deliberations to achieve clear and transparent decisions. (shrink)

Utilization of renewable energies in association with energy storage is increased in different applications such as electrical vehicles, electric boats, and smart grids. A robust controller strategy plays a significant role to optimally utilize the energy resources available in a power system. In this paper, a suitable controller for the energy resources of an EB which consists of a 5 kW solar power plant, 5 kW fuel cell, and 2 kW battery package is designed based on the linear parameter varying (...) controller design approach. Initially, all component dynamics are augmented, and by exploiting the sector-nonlinearity approach, the LPV representation is derived. Then, the LPV control method determines the suitable gains of the states’ feedbacks to provide the required pulse commands of the boost converters of the energy resources to regulate the DC-link voltage and supply the power of EB loads. Comparing with the state-of-the-art nonlinear control methods, the developed control approach assures the stability of the overall system, as it considers all component dynamics in the design procedure. The real-time simulation results demonstrate the performance of the designed controller in the creation of a constant DC-link voltage. (shrink)

In the following we study the evolution of support networks among egoists who differ widely in their degree of neediness, are free to choose their partners, and do so in opportunistic ways. No central authority is involved. The question we address is to what degree and under what aspect it shapes the structure of emerging solidarity networks whether we model egoistic actors as rational actors in a game theoretical sense or as adaptive actors, i.e. learning beings following a simple learning (...) mechanism which is driven by success and failure.1 The central modelling ideas to address that question are: Support relationships are modelled by a 2-person support game. The social space in which a network can emerge is a 2-dimensional cellular grid. Actors can play the support game simultaneously with all their neighbours. Not all cells are occupied. From time to time players have the opportunities to migrate. In one model we make our actors rational beings, in a second one we make them adaptive agents. Obviously we use a cellular automata framework of modelling . Especially because of its simplicity that framework has often proved fruitful for analysing micro/macro relations. (shrink)

Il s’agira ici de faire apparaître la régressivité — possibilité perpétuelle d’adjoindre un degré supplémentaire à l’énoncé — comme le principe même de l’ironie, ce qui conduit à la concevoir non comme une grille sémiotique et axiologique, mais comme une dynamique.La réflexion part de la cellule de base qu’est le signe ironique en tant que structure hiérarchisée à deux degrés, selon la conception traditionnelle. Cette dualité est d’abord analysée du point de vue sémantique, dans le cadre tropologique, puis sur les (...) plans axiologique, actantiel et énonciatif, ce qui aboutit à l’hypothèse de l’ironie comme trope métadiscursif, cumulant l’usage et la mention . Dans ce cadre, l’ironie se conçoit comme une représentation de représentation, comme un processus d’auto-duplication agissant par réflexivité critique et comique, et donc capable de se perpétuer virtuellement à l’infini puisque, s’appliquant à lui-même, il peut toujours ajouter un degré au précédent, sans pour autant l’annuler : le signe à deux niveaux ne constitue que la réalisation minimale de l’ironie, dont le second degré peut lui-même être réfléchi par un troisième, etc. Le « pouvoir réfléchissant » de l’ironie fait ainsi sa « force ascensionnelle » régressive, selon deux expressions empruntées à Proust.Interne au signe, ce dynamisme permet aussi, à l’échelle d’une oeuvre, de greffer différentes sortes d’ironie les unes sur les autres : la puissance créatrice du processus régressif conduit à envisager son rôle dans l’oeuvre d’art, en l’occurrence À la recherche du temps perdu, dont le texte multiplie de façon exemplaire et retorse les strates d’ironie. La Recherche, qui aura préalablement servi de support à toutes les analyses, permettra, par l’intermédiaire de Bergotte — écrivain ironiste dont le génie consiste dans le « pouvoir réfléchissant » et l’énergie créatrice dans la « force ascensionnelle » —, de poser la question de l’actualisation de la régressivité ironique dans l’oeuvre littéraire.Regressivity, as the perpetual possibility of adding a further degree to an utterance is the very principle of irony, which is thus conceived not under a semiotic and axiological grid, but as a dynamics.Reflection starts from the ironic sign as the basic cell and as a two tiered hierarchical structure, according to the traditional conception. This duality is first analysed from a semantical point of view, within the tropological framework, then on the axiological, actancial and utterance theoretic levels. This leads us to the hypothesis that irony is a metadiscursive trope, bringing together use and mention . Within this framework, irony is a representation of representation, an auto-duplicative process which acts through critical and comical reflectivity, and which is liable to perpetuate itself indefinitely, since, being auto-applicative, a new degree can always be added to the previous one, without cancelling itself : the two tiered sign being only the minimal realisation of irony, whose second degree can itself be reflected through a third, and so on. The “reflective power” of irony thus produces its “ascending force”.This mechanism internal to the sign allows also, at the level of the work, to plug different kinds of ironies onto each other : the creative power of the regressive process allows us to envisage its role in the work of art, in the case at hand in Remembrance of Things Past, whose text multiplies the various layers of irony. Proust’s work, which is here the basis of all our analyses, allows Bergotte — the ironist writer whose genius consists in the “reflective power” and in the “ascending force” — to raise the question of the actualisation of the ironical regressivity of the literary work. (shrink)

The vast majority (> 95%) of single-gene mutations in yeast affect not only the expression of the mutant gene, but also the expression of many other genes. These data suggest the presence of a previously uncharacterized ‘gene expression network’—a set of interactions between genes which dictate gene expression in the native cell environment. Here, we quantitatively analyze the gene expression network revealed by microarray expression data from 273 different yeast gene deletion mutants.(1) We find that gene expression interactions form a (...) robust, error-tolerant ‘scale-free’ network, similar to metabolic pathways(2) and artificial networks such as power grids and the internet.(3-5) Because the connectivity between genes in the gene expression network is unevenly distributed, a scale-free organization helps make organisms resistant to the deleterious effects of mutation, and is thus highly adaptive. The existence of a gene expression network poses practical considerations for the study of gene function, since most mutant phenotypes are the result of changes in the expression of many genes. Using principles of scale-free network topology, we propose that fragmenting the gene expression network via ‘genome-engineering’ may be a viable and practical approach to isolating gene function. BioEssays 24:267–274, 2002. © 2002 Wiley Periodicals, Inc.; DOI 10.1002/bies.10054. (shrink)

Reinvention of the form of expression is a conceptual approach characteristic for the evolution of all arts. This research study provides one such step forward in the advancement of scientific paper, a standard form of expression in natural sciences, toward more progressive terrains. The paper adopts the form of a theatrical play where a scientific family of four attempts to find the way around a writer’s block (Act I). Their idealess sense of confinement is overcome through arts or, more specifically, (...) through scientific research implementing the aesthetics of music as its key element. The characters record compositions differing in the degrees of consonance, rhythmicity and tonality, and play them to birds to observe their vocal and behavioral responses (Act II). They note that the birdsong volume drops significantly when the piano tunes, especially the compositionally complex ones, are played to the birds and increases signifcantly when the white noise of ocean waves is played. The bird count experiment proves indirectly that the birdsong volume reduction is an auditory response of the birds to music rather than the effect of their migrating to or away from the sound source. This science with the flavor of art elevates the characters beyond the limits of their confinement and they, exalted and uplifted, gain ideas for creative research in their own disciplines of biomedical science (Act III). They relinquish the newly gained freedom in favor of embracing love for humanity that underlies medical research and return to their confinement, where they conduct, in the coda of the paper, a series of experiments that venture beyond musicology and ornithology and fall in the domains of tissue engineering and drug delivery, but also psychology (Act III). First, sparrow nests are used as templates for tissue engineering constructs, which facilitate the growth of human fibroblastic cells better than their artificial, gridded replicas. Next, the shell of an Easter egg, predominantly calcite in composition, is used with success as a drug delivery carrier. Lastly, the bird nest drawing experiment demonstrates a greater mental health of children than that of the adults, correlating with one of the overarching points of the paper, which is to present children as a model for grownups to follow rather than the other way around. Over the course of the play, the characters discuss the value of the various fusions between art and science, question the limits of human language and repeatedly go off-topic to celebrate the freeness of the creative thinking process. The play reports on real-life research methods and scientific results through a narrative, without diminishing their empirical rigor and analytical accuracy. (shrink)

Many ontologies posit levels of existence. A whole exists at a level above its parts; a set exists at a level above its members. Hardware objects are at the lowest level in a computational ontology. Software objects exist at higher levels. The game of life illustrates a stratified computational ontology. The cells in the life grid are the hardware objects. An event is a function from cells to values 0 or 1. A process is a series of (...) events. A process contains a software object iff its content is generated by some rule that is independent of the rule for cells. We give a precise existence axiom for software objects. As expected, blinkers, gliders, puffer trains, and so on are software objects. Software objects satisfy traditional conceptions of materiality. Our conception of software objects has intriguing links to modern conceptions of material particles in terms of symmetry groups and topological invariants. Software objects are not abstract. (shrink)

We reviewed the output of research and innovation cooperation between Russia and the US, including publications and patents, in the four prospective areas of energy efficiency and renewable energy during 2007-2011. Joint US-Russia research groups appear to focus primarily on hydrogen energy (fuel cells), followed by solar photovoltaics. The upcoming areas of smart grid and biofuels were left out entirely both from research and innovation collaboration. Russian patents in green energy technologies registered in the US are very low (...) in comparison to those from Japan, Korea, and China. (shrink)

A model of face representation, inspired by the biology of the visual system, is compared to experimental data on the perception of facial similarity. The face representation model uses aggregate primary visual cortex (V1) cell responses topographically linked to a grid covering the face, allowing comparison of shape and texture at corresponding points in two facial images. When a set of relatively similar faces was used as stimuli, this Linked Aggregate Code (LAC) predicted human performance in similarity judgment experiments. (...) When faces of perceivable categories were used, dimensions such as apparent sex and race emerged from the LAC model without training. The dimensional structure of the LAC similarity measure for the mixed category task displayed some psychologically plausible features but also highlighted differences between the model and the human similarity judgements. The human judgements exhibited a racial perceptual bias that was not shared by the LAC model. The results suggest that the LAC based similarity measure may offer a fertile starting point for further modelling studies of face representation in higher visual areas, including studies of the development of biases in face perception. (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)

This essay examines the role of social interactions in the search for blood stem cells, in a recent episode of biomedical research. Linked to mid-20th century cell biology, genetics and radiation research, the search for blood stem cells coalesced in the 1960s and took a developmental turn in the late 1980s, with significant ramifications for immunology, stem cell and cancer biology. Like much contemporary biomedical research, this line of inquiry exhibits a complex social structure and includes several prominent (...) scientific successes, recognized as such by participating researchers. I use personal interviews and the published record to trace the social interactions crucial for scientific success in this episode. All recognized successes in this episode have two aspects: improved models of blood cell development, and new interfaces with other lines of research. The narrative of the search for blood stem cells thus yields a robust account of scientific success in practice, which generalizes to other scientific episodes and lends itself to expansion to include wider social contexts. (shrink)

The ArgumentMicroscopical consideration played a crucial role in German physiology in the period of, grosso modo, 1780–1830. Specifically, a conception of material change was established, according to which all life is grounded in the process of the generation of microscopical forms out of an amorphous, primitive generative substance. Embryological development, tissue growth, and the generation of microorganisms were all considered to be the manifestation of this fundamental developmental process. In contrast to the common historiography, I try to understand Theodor Schwann's (...) 1838 discovery of the cell theory in terms of the epistemological categories he applied to the prevailing conceptions of life and living matter. I argue that Schwann was able to discern cells not because of any superior microscopical methods, but rather as part of his wider investigative endeavor to explicate life processes according to specific causal agents. I argue that Schwann was able to demonstrate the existence of cells only when he considered animal tissues in terms of a causal relation between specific material agents and their effect, that is, the developmental history of tissue. (shrink)

BACKGROUND -/- The need for detailed description and modeling of cells drives the continuous generation of large and diverse datasets. Unfortunately, there exists no systematic and comprehensive way to organize these datasets and their information. CELDA (Cell: Expression, Localization, Development, Anatomy) is a novel ontology for the association of primary experimental data and derived knowledge to various types of cells of organisms. -/- RESULTS -/- CELDA is a structure that can help to categorize cell types based on species, (...) anatomical localization, subcellular structures, developmental stages and origin. It targets cells in vitro as well as in vivo. Instead of developing a novel ontology from scratch, we carefully designed CELDA in such a way that existing ontologies were integrated as much as possible, and only minimal extensions were performed to cover those classes and areas not present in any existing model. Currently, ten existing ontologies and models are linked to CELDA through the top-level ontology BioTop. Together with 15.439 newly created classes, CELDA contains more than 196.000 classes and 233.670 relationship axioms. CELDA is primarily used as a representational framework for modeling, analyzing and comparing cells within and across species in CellFinder, a web based data repository on cells (http://cellfinder.org). -/- CONCLUSIONS -/- CELDA can semantically link diverse types of information about cell types. It has been integrated within the research platform CellFinder, where it exemplarily relates cell types from liver and kidney during development on the one hand and anatomical locations in humans on the other, integrating information on all spatial and temporal stages. CELDA is available from the CellFinder website: http://cellfinder.org/about/ontology. (shrink)

: Experiments involving the transplantation of human stem cells and their derivatives into early fetal or embryonic nonhuman animals raise novel ethical issues due to their possible implications for enhancing the moral status of the chimeric individual. Although status-enhancing research is not necessarily objectionable from the perspective of the chimeric individual, there are grounds for objecting to it in the conditions in which it is likely to occur. Translating this ethical conclusion into a policy recommendation, however, is complicated by (...) the fact that substantial empirical and ethical uncertainties remain about which transplants, if any, would significantly enhance the chimeric individual's moral status. Considerations of moral status justify either an early-termination policy on chimeric embryos, or, in the absence of such a policy, restrictions on the introduction of pluripotent human stem cells into early-stage developing animals, pending the resolution of those uncertainties. (shrink)

The concept of the energid (which refers to “energy,” or “vital force”; in modern terms, adenosine triphosphate, ATP) is that the smallest unity of life is the nucleus and the amount of protoplasm the nucleus can “control” metabolically. The concept of the cell as a nucleus-protoplasm “unit” confined by either a cell membrane or cell wall (e.g., mammalian or land plant cells) is rejected. Examples of multinucleate organisms such as coenocytic algae are presented as “proof of concept” of the (...) energid. [Abstract and keywords not in original.]. (shrink)

This paper presents an account of the nature of stem cells based on the philosophical concept of disposition. It is argued that stem cells can be conceived as dispositional objects, and adopting this attitude allows overcoming some of the controversies surrounding the nature of stemness (most notably, the state vs. entity debate) because it offers a framework that accommodates the lessons from different theories. Additionally, the account is simultaneously useful for interpreting stem cell experiments and guiding potential interventions. (...) The account shows how different levels, both molecular and emergent network-level, play the primary causal role in explaining some empirical results, and hence they suggest that the explanations can be mechanistic or topological, respectively. The realization that any of these levels may play a more prominent causal role than another allows suggesting interventions at the genetic, molecular and population levels. (shrink)

With a previous paper (Niu & Wang, 1995), a general, hypothetical outline of the mechanism of carcinogenesis was proposed. With reference to the fact of starvation-induced hypermutation in micro-organisms, we propose that the hypoxia commonly seen in the cells at the centre of solid tumours might also result in hypermutation, and then p53-dependent programmed cell death. Like the apparently adaptive mutations in micro-organisms, only those genes (e.g. p53) that enable the cells to escape from apoptosis may be selected.

This paper gives insight into the Islamic bioethical discussion on harvesting and using human embryonic and adult stem cells. It describes some of the Islamic legal mechanisms involved in the bioethical discourse among Muslims. As the contemporary Islamic bioethical discourse is very diverse, the paper focuses on the critical discussion of related resolutions of the Saudi-based Islamic Fiqh Academy due to the esteem in which the IFA is held in the Islamic world and the pertinence of their rulings on (...) this issue. This study discusses the different sources of human adult and embryonic stem cells and their use from an Islamic perspective, while questioning some directions the Islamic bioethical discourse has taken. The paper invites interested parties to deliberate the use of some of the legal means resorted to in the ongoing Islamic bioethical discourse. (shrink)