4,586 research outputs found

    On the design of an interactive biosphere for the GLAS general circulation model

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    Improving the realism and accuracy of the GLAS general circulation model (by adding an interactive biosphere that will simulate the transfers of latent and sensible heat from land surface to atmosphere as functions of the atmospheric conditions and the morphology and physiology of the vegetation) is proposed

    Bion And Schön: Psychoanalytic Perspectives On Reflection In Action

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    Schön’s concept of ‘reflection in action’, particularly when interpreted from a sociocultural perspective, is often used as frame with which to consider the relationship between theoretical and tacit knowledge in the work of teachers. This paper presents an alternative interpretative frame for Schön which makes use of the ideas of Wilfred Bion, perhaps the most influential psychoanalyst of the second half of the twentieth century. It is argued that it is the productive emotional struggle with uncertainty that lies within Schön’s moment, which ultimately leads to the teacher coming to a moment of decision about what the child might need in a particular situation. This (contingent) understanding arises from a dialectic intertwining of knowledge derived from intersubjective relationship and theoretical knowledge, for example, about typical and atypical development in children. Implications for professional practice particularly in relation to working with children with special educational needs are discussed

    A search for inverse magnetic catalysis in thermal quark-meson models

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    We explore the parameter space of the two-flavor thermal quark-meson model and its Polyakov loop-extended version under the influence of a constant external magnetic field BB. We investigate the behavior of the pseudo critical temperature for chiral symmetry breaking taking into account the likely dependence of two parameters on the magnetic field: the Yukawa quark-meson coupling and the parameter T0T_0 of the Polyakov loop potential. Under the constraints that magnetic catalysis is realized at zero temperature and the chiral transition at B=0B=0 is a crossover, we find that the quark-meson model leads to thermal magnetic catalysis for the whole allowed parameter space, in contrast to the present picture stemming from lattice QCD.Comment: 8 pages, 5figure

    Numerical simulation of the world ocean circulation

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    A multi-level model, based on the primitive equations, is developed for simulating the temperature and velocity fields produced in the world ocean by differential heating and surface wind stress. The model ocean has constant depth, free slip at the lower boundary, and neglects momentum advection; so that there is no energy exchange between the barotropic and baroclinic components of the motion, although the former influences the latter through temperature advection. The ocean model was designed to be coupled to the UCLA atmospheric general circulation model, for the study of the dynamics of climate and climate changes. But here, the model is tested by prescribing the observed seasonally varying surface wind stress and the incident solar radiation, the surface air temperature and humidity, cloudiness and the surface wind speed, which, together with the predicted ocean surface temperature, determine the surface flux of radiant energy, sensible heat and latent heat

    Professional uncertainty, knowledge and relationship in the classroom: A psychosocial perspective

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    The extent to which teachers should make use of theoretical and expert knowledge as opposed to tacit experiential knowledge, and how these might be combined, is a perennial issue in discussions on pedagogy. This book addresses these debates through a creative development of the concept of productive uncertainty. Using case studies focusing on teachers working with children with autism, a particularly fertile crucible for considering uncertainty, the book explores how the radical 20th century psychoanalyst Wilfred Bion's epistemological approach to uncertainty can be used to re-frame Donald Schön's concept of reflection in action, offering a new perspective on the practice of teachers and other caring professionals. Several areas of potential uncertainty are identified, including uncertainty relating to areas of practice including diagnosis, the relationship between expert knowledge and practice, the implications of autism for autonomy and agency, and uncertainties in relation to the understanding of and use of new technologies. A strong argument is made, based on both theoretical and empirical grounds, that in juggling between theoretical and tacit knowledge in the classroom there is more to be gained by staying with the struggle with uncertainty than by fleeing from it too early, into the promise of expert solutions. Consideration is also given to the relative importance of specific theoretical training for teachers, both in general and in relation to working with children with special educational needs, in the context of international and UK policy developments in this area. This book will be of key value to researchers and postgraduates in the fields of education studies, teacher thinking and research, psychoanalytically informed psychosocial studies, as well as to practitioners working in special educational needs/autism education

    On thermal nucleation of quark matter in compact stars

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    The possibility of a hadron-quark phase transition in extreme astrophysical phenomena such as the collapse of a supernova is not discarded by the modern knowledge of the high-energy nuclear and quark-matter equations of state. Both the density and the temperature attainable in such extreme processes are possibly high enough to trigger a chiral phase transition. However, the time scales involved are an important issue. Even if the physical conditions for the phase transition are favorable (for a system in equilibrium), there may not be enough time for the dynamical process of phase conversion to be completed. We analyze the relevant time scales for the phase conversion via thermal nucleation of bubbles of quark matter and compare them to the typical astrophysical time scale, in order to verify the feasibility of the scenario of hadron-quark phase conversion during, for example, the core-collapse of a supernova.Comment: 6 pages, 4 figures, talk given at the International Conference SQM2009, Buzios, Rio de Janeiro, Brazil, Sep.27-Oct.2, 200

    Inclusive pedagogy and knowledge in special education: addressing the tension

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    There has been an increasing focus in policy and practice on adopting inclusive pedagogy as a way of reconceptualising how schools work with children with special educational needs (SEN). The paper considers the split between knowledge and pedagogy inherent in some dominant strains of inclusive pedagogy. Drawing on the ‘knowledge turn’ in curriculum studies, we argue that although an analytical distinction between knowledge and pedagogy may be useful, too strong a delineation between the two fails to best serve the needs of children with special needs. Specific implications for teacher education in relation to SEN in England are considered

    Gene Expression Profile Changes After Short-activating RNA-mediated Induction of Endogenous Pluripotency Factors in Human Mesenchymal Stem Cells

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    It is now recognized that small noncoding RNA sequences have the ability to mediate transcriptional activation of specific target genes in human cells. Using bioinformatics analysis and functional screening, we screened short-activating RNA (saRNA) oligonucleotides designed to target the promoter regions of the pluripotency reprogramming factors, Kruppel-like factor 4 (KLF4) and c-MYC. We identified KLF4 and c-MYC promoter-targeted saRNA sequences that consistently induced increases in their respective levels of nascent mRNA and protein expression in a time- and dose-dependent manner, as compared with scrambled sequence control oligonucleotides. The functional consequences of saRNA-induced activation of each targeted reprogramming factor were then characterized by comprehensively profiling changes in gene expression by microarray analysis, which revealed significant increases in mRNA levels of their respective downstream pathway genes. Notably, the microarray profile after saRNA-mediated induction of endogenous KLF4 and c-MYC showed similar gene expression patterns for stem cell- and cell cycle-related genes as compared with lentiviral vector-mediated overexpression of exogenous KLF4 and c-MYC transgenes, while divergent gene expression patterns common to viral vector-mediated transgene delivery were also noted. The use of promoter-targeted saRNAs for the activation of pluripotency reprogramming factors could have broad implications for stem cell research

    Nucleation of quark matter in protoneutron star matter

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    The phase transition from hadronic to quark matter may take place already during the early post-bounce stage of core collapse supernovae when matter is still hot and lepton rich. If the phase transition is of first order and exhibits a barrier, the formation of the new phase occurs via the nucleation of droplets. We investigate the thermal nucleation of a quark phase in supernova matter and calculate its rate for a wide range of physical parameters. We show that the formation of the first droplet of a quark phase might be very fast and therefore the phase transition to quark matter could play an important role in the mechanism and dynamics of supernova explosions.Comment: v3: fits version published in Physical Review

    Evaluation of Aposphaeria amaranthi as a Bioherbicide for Pigweed (Amaranthus Spp.)

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    Studies were conducted to determine the potential of the fungus, Aposphaeria amaranth!, as a bioherbicide for pigweeds (Amaranthus spp.). Experiments to establish the environmental parameters necessary for control of tumble pigweed (A. albus) demonstrated that an 8-hr dew period was sufficient for control of seedlings with four to six leaves, and that temperatures ranging from 20 to 28 C were conducive for disease development. Conidial concentrations as lowas 1x 10s conidia per ml also were sufficient for plant mortality. Host range tests demonstrated pathogenicity of A. amaranthi to several other species of Amaranthus, including biotypes resistant to triazine herbicides. Disease on redroot pigweed (A. retroflexus) was enhanced by incorporation of surfactants into inoculum suspensions. Field tests conducted in 1990 resulted in 73% control of redroot pigweed and 99% control of tumble pigweed. These results suggest that Aposphaeria amaranthi has potential as a bioherbicide for controlling pigweeds
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