121 research outputs found
Explorations in the Deictic Field
This paper focuses on the ways in which speakers make reference to themselves, to one another, and to objects in the everyday settings of talk. Drawing on research in linguistic anthropology, sociology, and linguistics, it proposes an approach to language based on the concepts of communicative practice, deictic field, and socially constituted objects of reference. Found in all human languages, deictics are expressions like English "this," "that," "here," and "there" whose meanings depend strictly on the occasions of their use. This paper critically examines current approaches to deixis, proposes an alternative framework based on the sociological concept of field, and applies this framework to deictic practice in Yucatec Maya. Drawing on the work of Buhler, Goffman, and Bourdieu, it adapts the field concept to the semiotic structure of deixis. The result is an analysis of deictic practice as an emergent construal of socially embedded deictic fields involving practical equivalences, counterpart relations among objects, and rules of thumb
The plurality of temporal reckoning among the Maya
This paper presents an overview of time reckoning in several domains of Maya language and culture, as observed in the Sierra region of Yucatan in the last decades of the twentieth century. It demonstrates that multiple systems of temporal reckoning and orientation co-operate in the traditional domains of daily practice, and it attempts to formulate principles by which different systems are combined in actional frameworks It is argued that most cyclicity in contemporary Yucatec Maya is derivative of natural or social processes and that in rituals it results from the translation of spatial arrays into temporal sequences. The paper tracks the varieties of cyclic and spiral time measurement in several domains, where different units and levels of temporal measurement and different rhythms are observed: 1) the field of co-presence in which utterances are performed, including deictic time; 2) the diurnal cycle and its actional correlates; 3) the agricultural cycles, the forest life cycle and the labor they imply; 4) domestic space whose time involves in addition the age and generational relations among co-residents; 5) ritual time in Yucatec shamanic practice, which is given special attention. Ritual practices display the most dramatic cyclicity, compounded by sedimentation, deictic time, historical time and cosmological space. Their chronometric dimensions are so elaborate that rituals can be considered a time machine. Viewed from practice, there is no single modality of Maya time, but a diachronic synchronization of multiple temporal streams which produces time as the variable product of tzol reproduction and meyah ‘work.’Este artÃculo presenta una vista de conjunto de las formas de comput del tiempo en varios dominios de la cultura y de la lengua maya, tal como fueron observadas en la región de la sierra de Yucatán en los últimos decenios del siglo xx. Se demuestra que una multiplicidad de sistemas de cálculo y orientación temporales cooperan en los ámbitos tradicionales de las prácticas cotidianas, y se intenta formular ciertos principios que rigen la combinación de los diferentes sistemas dentro de los marcos de la acción. Se arguye que la mayor parte de las configuraciones cÃclicas de los mayas yucatecos contemporáneos puede derivarse de procesos naturales o sociales y que, en el ritual, resulta de la traducción de disposiciones espaciales en secuencias temporales. El autor rastrea la variedad de mediciones del tiempo en varios dominios, para los cuales se observa una diversidad tanto de unidades y niveles de medida temporal como de ritmos: 1) el campo de co-presencia en el cual ocurren las enunciaciones, incluyendo el tiempo deÃctico; 2) el ciclo diurno y sus correlatos accionales ; 3) los ciclos agrÃcolas y silvestres, y las labores que implican ; 4) el espacio doméstico que supone además la edad y las relaciones intergeneracionales entre coresidentes. 5) el tiempo ritual en las prácticas chamanicas yucatecas, al cual se presta mayor atención. Éstas prácticas manifiestan la forma de ciclicidad más dramática, compuesta por sedimentación, tiempo deÃctico, tiempo cÃclico y espacio cosmológico. Sus dimensiones cronométricas son tan elaboradas que los rituales pueden ser considerados como máquinas del tiempo. Del punto de vista de las prácticas, no existe una modalidad del tiempo maya única, sino una sincronización diacrónica de corrientes temporales múltiples que hacen del tiempo un producto variable del ordenamiento ‘tzol’ y del trabajo ‘meyah’.Cet article présente une vue d’ensemble des formes de comput du temps dans plusieurs domaines de la culture et de la langue maya, telle qu’observée dans la région centrale du Yucatán durant les dernières décennies du xxe siècle. Il s’attache à démontrer qu’une multiplicité de systèmes de calcul et d’orientation temporels sont conjointement à l’œuvre dans les domaines traditionnels des pratiques quotidiennes. Il tente de formuler certains des principes qui régissent la combinaison des différents systèmes au sein de cadres actionnels. L’auteur argumente que la plupart des configurations cycliques des Mayas yucatèques contemporains sont dérivées de processus naturels ou sociaux et que, dans le rituel, elles résultent de la traduction de dispositions spatiales dans des séquences temporelles. Il recherche la variété des mesures du temps dans plusieurs domaines, où on observe une diversité tant d’unités et niveaux de mesure temporelle que de rythmes : 1) le champ de co-présence au sein duquel prennent place les énonciations, incluant le temps déictique ; 2) le cycle diurne et ses corrélats actionnels ; 3) les cycles agricoles et sylvestres et les tâches qu’ils impliquent ; 4) l’espace domestique pour lequel s’ajoutent l’âge et les relations intergénérationnelles entre co-résidents ; 5) le temps rituel dans les pratiques chamaniques yucatèques, auquel il est porté une particulière attention. Ces pratiques manifestent la forme de cyclicité la plus dramatique, composée par sédimentation de temps déictique, temps historique et espace cosmologique. Leurs dimensions chronométriques sont si élaborées que les rituels peuvent être considérés comme des machines à voyager dans le temps. Du point de vue des pratiques, il n’y a pas une simple modalité du temps maya, mais plutôt une synchronisation diachronique de courants temporels multiples qui fait du temps une variable soumise à l’ordonnancement ‘tzol’ et au travail ‘meyah’
Présent passé, passé présent : les enjeux de l’histoire régressive
L’anthropologie s’est longtemps interrogé sur le rapport entre la société comme système actuel d’une part, et l’histoire plus ou moins longue dont elle est issue, de l’autre. Sont impliqués les disciplines de l’archive et du terrain, la diachronie de l’histoire et la synchronie dynamique du présent, le passage du passé au présent, et son inverse, la contingence et la necessité, la valeur des pratiques culturelles du présent comme archive vivante du passé, et la réproduction des « visions » culturelles. Toutes ces problématiques sont en jeu dans le projet de l’histoire regressive selon Nathan Wachtel. qui a ouvert tout un horizon de recherches Americanistes. Ces recherches comprennent « la nouvelle philologie » de Lockhart et de ses élèves, les recherches de VR Bricker, M. Edmonson, NM Farriss, G. Jones, d’Aurore Monod Becquelin et de moi-même en zone Maya, et une litterature importante qui réanalyse le monde colonial dans des termes qui auraient été impensables pour les chercheurs de générations antérieurs. Une esquisse des grands débats contemporains dans la zone maya présente la possibilité de mieux cerner le génératif cette approche de la societé dans l’histoire
Discussion
Mme Carmen BERNANDMerci beaucoup pour l’exposé. Devant ces quatre exposés d’une très grande richesse, je ne peux pas lancer une question unique comme cela a été réalisé la veille. C’est sans doute par incompétence de ma part, mais je vais tout de même faire quelques commentaires de ce qui m’a impressionnée et ensuite lancer la discussion avec les personnes intéressées et la salle. Au fur et à mesure que j’entendais les communications et surtout les citations de ces trois ouvrages de Nathan qu..
Mutations in CENPE define a novel kinetochore-centromeric mechanism for microcephalic primordial dwarfism
Defects in centrosome, centrosomal-associated and spindle-associated proteins are the most frequent cause of primary microcephaly (PM) and microcephalic primordial dwarfism (MPD) syndromes in humans. Mitotic progression and segregation defects, microtubule spindle abnormalities and impaired DNA damage-induced G2-M cell cycle checkpoint proficiency have been documented in cell lines from these patients. This suggests that impaired mitotic entry, progression and exit strongly contribute to PM and MPD. Considering the vast protein networks involved in coordinating this cell cycle stage, the list of potential target genes that could underlie novel developmental disorders is large. One such complex network, with a direct microtubule-mediated physical connection to the centrosome, is the kinetochore. This centromeric-associated structure nucleates microtubule attachments onto mitotic chromosomes. Here, we described novel compound heterozygous variants in CENPE in two siblings who exhibit a profound MPD associated with developmental delay, simplified gyri and other isolated abnormalities. CENPE encodes centromere-associated protein E (CENP-E), a core kinetochore component functioning to mediate chromosome congression initially of misaligned chromosomes and in subsequent spindle microtubule capture during mitosis. Firstly, we present a comprehensive clinical description of these patients. Then, using patient cells we document abnormalities in spindle microtubule organization, mitotic progression and segregation, before modeling the cellular pathogenicity of these variants in an independent cell system. Our cellular analysis shows that a pathogenic defect in CENP-E, a kinetochore-core protein, largely phenocopies PCNT-mutated microcephalic osteodysplastic primordial dwarfism-type II patient cells. PCNT encodes a centrosome-associated protein. These results highlight a common underlying pathomechanism. Our findings provide the first evidence for a kinetochore-based route to MPD in humans
Can Monkeys Choose Optimally When Faced with Noisy Stimuli and Unequal Rewards?
We review the leaky competing accumulator model for two-alternative forced-choice decisions with cued responses, and propose extensions to account for the influence of unequal rewards. Assuming that stimulus information is integrated until the cue to respond arrives and that firing rates of stimulus-selective neurons remain well within physiological bounds, the model reduces to an Ornstein-Uhlenbeck (OU) process that yields explicit expressions for the psychometric function that describes accuracy. From these we compute strategies that optimize the rewards expected over blocks of trials administered with mixed difficulty and reward contingencies. The psychometric function is characterized by two parameters: its midpoint slope, which quantifies a subject's ability to extract signal from noise, and its shift, which measures the bias applied to account for unequal rewards. We fit these to data from two monkeys performing the moving dots task with mixed coherences and reward schedules. We find that their behaviors averaged over multiple sessions are close to optimal, with shifts erring in the direction of smaller penalties. We propose two methods for biasing the OU process to produce such shifts
The direct effect of Focal Adhesion Kinase (FAK), dominant-negative FAK, FAK-CD and FAK siRNA on gene expression and human MCF-7 breast cancer cell tumorigenesis
<p>Abstract</p> <p>Background</p> <p>Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that plays an important role in survival signaling. FAK has been shown to be overexpressed in breast cancer tumors at early stages of tumorigenesis.</p> <p>Methods</p> <p>To study the direct effect of FAK on breast tumorigenesis, we developed Tet-ON (tetracycline-inducible) system of MCF-7 breast cancer cells stably transfected with FAK or dominant-negative, C-terminal domain of FAK (FAK-CD), and also FAKsiRNA with silenced FAK MCF-7 stable cell line. Increased expression of FAK in isogenic Tet-inducible MCF-7 cells caused increased cell growth, adhesion and soft agar colony formation <it>in vitro</it>, while expression of dominant-negative FAK inhibitor caused inhibition of these cellular processes. To study the role of induced FAK and FAK-CD <it>in vivo</it>, we inoculated these Tet-inducible cells in nude mice to generate tumors in the presence or absence of doxycycline in the drinking water. FAKsiRNA-MCF-7 cells were also injected into nude mice to generate xenograft tumors.</p> <p>Results</p> <p>Induction of FAK resulted in significant increased tumorigenesis, while induced FAK-CD resulted in decreased tumorigenesis. Taq Man Low Density Array assay demonstrated specific induction of FAKmRNA in MCF-7-Tet-ON-FAK cells. DMP1, encoding cyclin D binding myb-like protein 1 was one of the genes specifically affected by Tet-inducible FAK or FAK-CD in breast xenograft tumors. In addition, silencing of FAK in MCF-7 cells with FAK siRNA caused increased cell rounding, decreased cell viability <it>in vitro </it>and inhibited tumorigenesis <it>in vivo</it>. Importantly, Affymetrix microarray gene profiling analysis using Human Genome U133A GeneChips revealed >4300 genes, known to be involved in apoptosis, cell cycle, and adhesion that were significantly down- or up-regulated (p < 0.05) by FAKsiRNA.</p> <p>Conclusion</p> <p>Thus, these data for the first time demonstrate the direct effect of FAK expression and function on MCF-7 breast cancer tumorigenesis <it>in vivo </it>and reveal specific expression of genes affected by silencing of FAK.</p
Metabolic Network for the Biosynthesis of Intra- and Extracellular alpha-Glucans Required for Virulence of Mycobacterium tuberculosis
Mycobacterium tuberculosis synthesizes intra- and extracellular alpha-glucans that were believed to originate from separate pathways. The extracellular glucose polymer is the main constituent of the mycobacterial capsule that is thought to be involved in immune evasion and virulence. However, the role of the alpha-glucan capsule in pathogenesis has remained enigmatic due to an incomplete understanding of alpha-glucan biosynthetic pathways preventing the generation of capsule-deficient mutants. Three separate and potentially redundant pathways had been implicated in alpha-glucan biosynthesis in mycobacteria: the GlgC-GlgA, the Rv3032 and the TreS-Pep2-GlgE pathways. We now show that alpha-glucan in mycobacteria is exclusively assembled intracellularly utilizing the building block alpha-maltose-1-phosphate as the substrate for the maltosyltransferase GlgE, with subsequent branching of the polymer by the branching enzyme GlgB. Some alpha-glucan is exported to form the alpha-glucan capsule. There is an unexpected convergence of the TreS-Pep2 and GlgC-GlgA pathways that both generate alpha-maltose-1-phosphate. While the TreS-Pep2 route from trehalose was already known, we have now established that GlgA forms this phosphosugar from ADP-glucose and glucose 1-phosphate 1000-fold more efficiently than its hitherto described glycogen synthase activity. The two routes are connected by the common precursor ADPglucose, allowing compensatory flux from one route to the other. Having elucidated this unexpected configuration of the metabolic pathways underlying alpha-glucan biosynthesis in mycobacteria, an M. tuberculosis double mutant devoid of alpha-glucan could be constructed, showing a direct link between the GlgE pathway, alpha-glucan biosynthesis and virulence in a mouse infection model
Expression of Constitutively Active CDK1 Stabilizes APC-Cdh1 Substrates and Potentiates Premature Spindle Assembly and Checkpoint Function in G1 Cells
Mitotic progression in eukaryotic cells depends upon the activation of cyclin-dependent kinase 1 (CDK1), followed by its inactivation through the anaphase-promoting complex (APC)/cyclosome-mediated degradation of M-phase cyclins. Previous work revealed that expression of a constitutively active CDK1 (CDK1AF) in HeLa cells permitted their division, but yielded G1 daughter cells that underwent premature S-phase and early mitotic events. While CDK1AF was found to impede the sustained activity of APC-Cdh1, it was unknown if this defect improperly stabilized mitotic substrates and contributed to the occurrence of these premature M phases. Here, we show that CDK1AF expression in HeLa cells improperly stabilized APC-Cdh1 substrates in G1-phase daughter cells, including mitotic kinases and the APC adaptor, Cdc20. Division of CDK1AF-expressing cells produced G1 daughters with an accelerated S-phase onset, interrupted by the formation of premature bipolar spindles capable of spindle assembly checkpoint function. Further characterization of these phenotypes induced by CDK1AF expression revealed that this early spindle formation depended upon premature CDK1 and Aurora B activities, and their inhibition induced rapid spindle disassembly. Following its normal M-phase degradation, we found that the absence of Wee1 in these prematurely cycling daughter cells permitted the endogenous CDK1 to contribute to these premature mitotic events, since expression of a non-degradable Wee1 reduced the number of cells that exhibited premature cyclin B1oscillations. Lastly, we discovered that Cdh1-ablated cells could not be forced into a premature M phase, despite cyclin B1 overexpression and proteasome inhibition. Together, these results demonstrate that expression of constitutively active CDK1AF hampers the destruction of critical APC-Cdh1 targets, and that this type of condition could prevent newly divided cells from properly maintaining a prolonged interphase state. We propose that this more subtle type of defect in activity of the APC-driven negative-feedback loop may have implications for triggering genome instability and tumorigenesis
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Bourdieusian Reflections on Language: Unavoidable Conditions of the Real Speech Situation
The main purpose of this paper is to shed light on Pierre Bourdieu’s conception of language. Although he has dedicated a significant part of his work to the study of language and even though his analysis of language has been extensively discussed in the literature, almost no attention has been paid to the factthat Bourdieu’s account of language is based on a number of ontological presuppositions, that is, on a set of universal assumptions about the very nature of language. This article aims to fill this gap in the literature by offering a detailed overview of 10 key features which, from a Bourdieusian point of view, can be regarded as inherent in language. On the basis of this enquiry,the study seeks todemonstrate that——contraryto commonbelief——there is not only a Bourdieusian sociology of language but also a Bourdieusian philosophy of language, which provides a useful theoretical framework for examining the unavoidable conditions of the real speech situation. The paper draws to a close by reflecting on the flaws and limitations of Bourdieu’s approach to language
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