45 research outputs found

    The parent?infant dyad and the construction of the subjective self

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    Developmental psychology and psychopathology has in the past been more concerned with the quality of self-representation than with the development of the subjective agency which underpins our experience of feeling, thought and action, a key function of mentalisation. This review begins by contrasting a Cartesian view of pre-wired introspective subjectivity with a constructionist model based on the assumption of an innate contingency detector which orients the infant towards aspects of the social world that react congruently and in a specifically cued informative manner that expresses and facilitates the assimilation of cultural knowledge. Research on the neural mechanisms associated with mentalisation and social influences on its development are reviewed. It is suggested that the infant focuses on the attachment figure as a source of reliable information about the world. The construction of the sense of a subjective self is then an aspect of acquiring knowledge about the world through the caregiver's pedagogical communicative displays which in this context focuses on the child's thoughts and feelings. We argue that a number of possible mechanisms, including complementary activation of attachment and mentalisation, the disruptive effect of maltreatment on parent-child communication, the biobehavioural overlap of cues for learning and cues for attachment, may have a role in ensuring that the quality of relationship with the caregiver influences the development of the child's experience of thoughts and feelings

    Study of ttbar Production in ppbar Collisions Using Total Transverse Energy

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    We analyze a sample of W + jet events collected with the Collider Detector at Fermilab (CDF) in ppbar collisions at sqrt(s) = 1.8 TeV to study ttbar production. We employ a simple kinematical variable "H", defined as the scalar sum of the transverse energies of the lepton, neutrino and jets. For events with a W boson and four or more jets, the shape of the "H" distribution deviates by 3.8 standard deviations from that expected from known backgrounds to ttbar production. However this distribution agrees well with a linear combination of background and ttbar events, the agreement being best for a top mass of 180 GeV/c^2.Comment: Postscript file (gzip+uuencode). 5-page, two-column PRL format (RevTex). Submitted to Phys. Rev. Lett. 09 June 199

    Balanced scorecard implementation in Jordan: An initial analysis

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    This paper analyses the state of implementation of the balanced scorecard (BSC) among Jordanian industrial companies. From an economic perspective, Jordan is an exemplar of an advanced developing nation in the Middle Eastern region. The paper is part of a wider investigation into the usage of Western developed performance measurement diversity techniques in the Jordanian context. A quantitative survey of 168 companies provided insight into the level of implementation, diffusion and purposes for the use of the BSC approach among medium and large industrial companies. The results showed that 35.1% of the surveyed companies used the BSC approach. The finding also indicated that approximately a further 30% of the responding companies were either considering or currently implementing the BSC approach. The results revealed some inconsistency in terms of the types and number of BSC perspectives used. Companies that had implemented the BSC used different perspectives in their BSC with a greater focus on the original four perspectives as suggested by the original authors Kaplan and Norton

    Physical models of thin film polycrystalline solar cells based on measured grain-boundary and electronic-parameter properties. Final report, September 18, 1978-December 31, 1979

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    The research has sought the following: to identify and characterize the basic photovoltaic mechanisms that govern the conversion efficiency of polycrystalline thin-film solar cells; to experimentally determine the electronic parameters related to these photovoltaic mechanisms; and to relate these mechanisms and parameters to the conversion efficiency through theoretical physical models developed for engineering design. These objectives are all intimately related. The emphasis of the work has been on polysilicon, although it is building a foundation of understanding useful for similar research in the future on other thin-film materials. Progress is reported. (WHK

    Physical models of thin film polycrystalline solar cells based on measured grain-boundary and electronic-parameter properties. Quarterly report

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    Solar cells fabricated on polycrystalline silicon, either bulk or thin-film, can potentially be cost-effective when used in terrestrial photovoltaic energy-conversion systems. To achieve this goal, the polysilicon cell efficiency must be increased considerably from its present values. A severe limitation to the cell efficiency is due to the grain boundaries and their influence on carrier recombination. To remove this limitation, an understanding of the fundamental physics underlying the effects of the grain boundaries on cell performance is helpful. This fundamental physics is discussed, and models are developed for recombination currents in polysilicon pn-junction solar cells. Several analytic approximations, suggested by physical insight, are used and checked ultimately for self-consistency with the results of the analysis. The models are defined such that their parameters can be related directly to measurements, and the models are hence useful in interpreting experimental results. They also can be used to study, in a systematic way, cell-design modifications to improve the efficiency, e.g., grain-boundary passivation techniques

    Glucocorticoid Regulation of Human and Ovine Parturition: The Relationship Between Fetal Hypothalamic-Pituitary-Adrenal Axis Activation and Intrauterine Prostaglandin Production

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    International audienceBirth in many animal species and in humans is associated with activation of hypothalamic-pituitary-adrenal function in the fetus and the increased influence of glucocorticoids on trophoblast cells of the placenta and fetal membranes. We suggest that in ovine pregnancy glucocorticoids directly increase fetal placental prostaglandin production, and indirectly increase prostaglandin production by maternal uterine tissues through the stimulation of placental estradiol synthesis. The events of ovine parturition are compared with those of human parturition. In the latter, we suggest similar direct effects of glucocorticoids on prostaglandin synthesis and metabolism in fetal membranes and similar indirect effects mediated by glucocorticoid-stimulated increases in intrauterine corticotropin-releasing hormone expression

    The fetal placental hypothalamic–pituitary–adrenal (HPA) axis, parturition and post natal health

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    International audienceA general characteristic of fetal endocrine maturation across different species is the enhanced activity of the fetal hypothalamic-pituitary-adrenal (HPA) axis during late gestation. Precocious activation of this axis may occur when the fetus is exposed to an adverse intra-uterine environment, such as hypoxemia. HPA development is associated with increased levels of ACTH(1-39) and adrenal corticosteroids (cortisol in sheep and human) in the fetal circulation, and increased expression of mRNA encoding corticotrophin releasing hormone (CRH) in the hypothalamus, proopiomelanocortin (POMC) in the pituitary, and key steroidogenic enzymes in the fetal adrenal. At term, increased levels of cortisol act on the placenta/trophoblast derived cells to increase expression of prostaglandin synthase Type II (PGHS-II). In human gestation, cortisol also decreases expression of 15-hydroxyprostaglandin dehydrogenase (PGDH) in chorionic trophoblast cells. Increased synthesis and decreased metabolism of prostaglandin (PG) results, during late gestation, in enhanced output of primary PG, which in turn increases the activity of 11 beta-hydroxysteroid dehydrogenase (11 beta HSD) in the human fetal membranes. Increased chorionic 11 beta HSD-1 results in increased local generation of cortisol from cortisone, with further paracrine/autocrine stimulation of PG output. Increased fetal cortisol contributes to the maturation of organ systems required for postnatal extra-uterine survival. However, excessive levels of feto-placental glucocorticoid, derived from maternal administration of synthetic corticosteroids or sustained endogenous fetal cortisol production, results in intrauterine growth restriction. Fetal sheep, exposed to maternal betamethasone in late gestation, develop insulin resistance and exaggerated adrenal responses to HPA stimulation by 6-12 months postnatal life. Thus, the level of fetal HPA activity is crucial not only for determining gestation length, but may also predict pathophysiologic adjustments in later life
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