741 research outputs found

    Regression and the Maternal in the History of Psychoanalysis, 1900-1957

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    This paper examines the history of the concept of ‘regression’ as it was perceived by Sandor Ferenczi and some of his followers in the first half of the twentieth century. The first part provides a short history of the notion of ‘regression’ from the late nineteenth century to Ferenczi's work in the 1920s and 1930s. The second and third parts of the paper focus on two other thinkers on regression, who worked in Britain, under the influence of the Ferenczian paradigm – the interwar Scottish psychiatrist, Ian D. Suttie; and the British-Hungarian psychoanalyst, and Ferenczi's most important pupil, Michael Balint. Rather than a descriptive term which comes to designate a pathological mental stage, Ferenczi understood ‘regression’ as a much more literal phenomenon. For him, the mental desire to go backwards in time is a universal one, and a consequence of an inevitable traumatic separation from the mother in early childhood, which has some deep personal and cultural implications. The paper aims to show some close affinities between the preoccupation of some psychoanalysts with ‘regression’, and the growing interest in social and cultural aspects of ‘motherhood’ and ‘the maternal role’ in mid-twentieth-century British society

    Peculiarities of ball-milling induced crystalline-amorphous transformation in Cu-Zr-Al-Ni-Ti alloys

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    An amorphization process in (Cu49Zr45-xAl6+x)100-y-zNiyTiz (x = 1, y, z = 0; 5; 10) induced by ball-milling is reported in the present work. The aim was investigation of the effect of Ni and Ti addition to Cu49Zr45Al6 and Cu49Zr44Al7 based alloys as well as type of initial phases on the amorphization processes. Also the milling time sufficient for obtaining fully amorphous state was determined. The entire milling process lasted 25 h. Drastic structural changes were observed in each alloy after first 5 h of milling. In most cases, after 15 h of milling the powders had fully amorphous structure according to XRD except for those ones, where TEM revealed a few nanosized crystalline particles in the amorphous matrix. In (Cu49Zr45Al6)80Ni10Ti10 alloy the amorphization process took place after 12 h of milling and the amorphous state was stable up to 25 h of milling. In the case of (Cu49Zr44Al7)80Ni10Ti10 alloy the powders have fully amorphous structure between 12 h and 15 h of milling. © 2015 Elsevier Ltd. All rights reserved

    Symmetries in Quantum Key Distribution and the Connection between Optimal Attacks and Optimal Cloning

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    We investigate the connection between the optimal collective eavesdropping attack and the optimal cloning attack where the eavesdropper employs an optimal cloner to attack the quantum key distribution (QKD) protocol. The analysis is done in the context of the security proof in [Devetak and Winter, Proc. of the Roy. Soc. of London Series A, 461, 207 (2005); Kraus, Gisin and Renner, Phys. Rev. Lett. 95, 080501 (2005)] for discrete variable protocols in d-dimensional Hilbert spaces. We consider a scenario in which the protocols and cloners are equipped with symmetries. These symmetries are used to define a quantum cloning scenario. We find that, in general, it does not hold that the optimal attack is an optimal cloner. However, there are classes of protocols, where we can identify an optimal attack by an optimal cloner. We analyze protocols with 2, d and d+1 mutually unbiased bases where d is a prime, and show that for the protocols with 2 and d+1 MUBs the optimal attack is an optimal cloner, but for the protocols with d MUBs, it is not. Finally, we give criteria to identify protocols which have different signal states, but the same optimal attack. Using these criteria, we present qubit protocols which have the same optimal attack as the BB84 protocol or the 6-state protocol

    Strong binding of myosin heads stretches and twists the actin helix

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    AbstractCalculation of the size of the power stroke of the myosin motor in contracting muscle requires knowledge of the compliance of the myofilaments. Current estimates of actin compliance vary significantly introducing uncertainty in the mechanical parameters of the motor. Using x-ray diffraction on small bundles of permeabilized fibers from rabbit muscle we show that strong binding of myosin heads changes directly the actin helix. The spacing of the 2.73-nm meridional x-ray reflection increased by 0.22% when relaxed fibers were put into low-tension rigor (<10kN/m2) demonstrating that strongly bound myosin heads elongate the actin filaments even in the absence of external tension. The pitch of the 5.9-nm actin layer line increased by ∼0.62% and that of the 5.1-nm layer line decreased by ∼0.26%, suggesting that the elongation is accompanied by a decrease in its helical angle (∼166°) by ∼0.8°. This effect explains the difference between actin compliance revealed from mechanical experiments with single fibers and from x-ray diffraction on whole muscles. Our measurement of actin compliance obtained by applying tension to fibers in rigor is consistent with the results of mechanical measurements

    Why Muscle is an Efficient Shock Absorber

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    Copyright: © 2014 Ferenczi et al. Skeletal muscles power body movement by converting free energy of ATP hydrolysis into mechanical work. During the landing phase of running or jumping some activated skeletal muscles are subjected to stretch. Upon stretch they absorb body energy quickly and effectively thus protecting joints and bones from impact damage. This is achieved because during lengthening, skeletal muscle bears higher force and has higher instantaneous stiffness than during isometric contraction, and yet consumes very little ATP. We wish to understand how the actomyosin molecules change their structure and interaction to implement these physiologically useful mechanical and thermodynamical properties. We monitored changes in the low angle x-ray diffraction pattern of rabbit skeletal muscle fibers during ramp stretch compared to those during isometric contraction at physiological temperature using synchrotron radiation. The intensities of the off-meridional layer lines and fine interference structure of the meridional M3 myosin x-ray reflection were resolved. Mechanical and structural data show that upon stretch the fraction of actin-bound myosin heads is higher than during isometric contraction. On the other hand, the intensities of the actin layer lines are lower than during isometric contraction. Taken together, these results suggest that during stretch, a significant fraction of actin-bound heads is bound non-stereo-specifically, i.e. they are disordered azimuthally although stiff axially. As the strong or stereo-specific myosin binding to actin is necessary for actin activation of the myosin ATPase, this finding explains the low metabolic cost of energy absorption by muscle during the landing phase of locomotion.The work was funded by the Russian Foundation for Basic Research (RFBR) grants 11-04-00908 to A.K.T. and 11-04-00750 to S.Y.B., by the Presidium of the Russian Academy of Sciences to S.Y.B., by the Medical Research Council (UK) G0501704 to M.A.F, by an EBSA Travel Fellowship to G.V.K., and by a Royal Society Travel award to N.A.K. and A.K.T

    Attachment styles and personal growth following romantic breakups: The mediating roles of distress, rumination, and tendency to rebound

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    © 2013 Marshall et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This article has been made available through the Brunel Open Access Publishing Fund.The purpose of this research was to examine the associations of attachment anxiety and avoidance with personal growth following relationship dissolution, and to test breakup distress, rumination, and tendency to rebound with new partners as mediators of these associations. Study 1 (N = 411) and Study 2 (N = 465) measured attachment style, breakup distress, and personal growth; Study 2 additionally measured ruminative reflection, brooding, and proclivity to rebound with new partners. Structural equation modelling revealed in both studies that anxiety was indirectly associated with greater personal growth through heightened breakup distress, whereas avoidance was indirectly associated with lower personal growth through inhibited breakup distress. Study 2 further showed that the positive association of breakup distress with personal growth was accounted for by enhanced reflection and brooding, and that anxious individuals’ greater personal growth was also explained by their proclivity to rebound. These findings suggest that anxious individuals’ hyperactivated breakup distress may act as a catalyst for personal growth by promoting the cognitive processing of breakup-related thoughts and emotions, whereas avoidant individuals’ deactivated distress may inhibit personal growth by suppressing this cognitive work
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