Flux rope, hyperbolic flux tube, and late EUV phases in a non-eruptive circular-ribbon flare

We present a detailed study of a confined circular flare dynamics associated with 3 UV late phases in order to understand more precisely which topological elements are present and how they constrain the dynamics of the flare. We perform a non-linear force free field extrapolation of the confined flare observed with the HMI and AIA instruments onboard SDO. From the 3D magnetic field we compute the squashing factor and we analyse its distribution. Conjointly, we analyse the AIA EUV light curves and images in order to identify the post-flare loops, their temporal and thermal evolution. By combining both analysis we are able to propose a detailed scenario that explains the dynamics of the flare. Our topological analysis shows that in addition to a null-point topology with the fan separatrix, the spine lines and its surrounding Quasi-Separatix Layers halo (typical for a circular flare), a flux rope and its hyperbolic flux tube (HFT) are enclosed below the null. By comparing the magnetic field topology and the EUV post-flare loops we obtain an almost perfect match 1) between the footpoints of the separatrices and the EUV 1600~\AA{} ribbons and 2) between the HFT's field line footpoints and bright spots observed inside the circular ribbons. We showed, for the first time in a confined flare, that magnetic reconnection occured initially at the HFT, below the flux rope. Reconnection at the null point between the flux rope and the overlying field is only initiated in a second phase. In addition, we showed that the EUV late phase observed after the main flare episode are caused by the cooling loops of different length which have all reconnected at the null point during the impulsive phase.Comment: Astronomy & Astrophysics, in pres

Stomach content analyses of mullet from the Swartkops estuary

The stomach content of four species of mullet (Mugil cephalus, Liza dumerili, Liza richardsonii and Liza tricuspidens), was analyzed. The nature of the stomach content gave some indication of the areas in which each species of mullet had been feeding, the type of substratum from which each had been feeding and the diatom species which each ate

Synchronous Behavior of Two Coupled Electronic Neurons

We report on experimental studies of synchronization phenomena in a pair of analog electronic neurons (ENs). The ENs were designed to reproduce the observed membrane voltage oscillations of isolated biological neurons from the stomatogastric ganglion of the California spiny lobster Panulirus interruptus. The ENs are simple analog circuits which integrate four dimensional differential equations representing fast and slow subcellular mechanisms that produce the characteristic regular/chaotic spiking-bursting behavior of these cells. In this paper we study their dynamical behavior as we couple them in the same configurations as we have done for their counterpart biological neurons. The interconnections we use for these neural oscillators are both direct electrical connections and excitatory and inhibitory chemical connections: each realized by analog circuitry and suggested by biological examples. We provide here quantitative evidence that the ENs and the biological neurons behave similarly when coupled in the same manner. They each display well defined bifurcations in their mutual synchronization and regularization. We report briefly on an experiment on coupled biological neurons and four dimensional ENs which provides further ground for testing the validity of our numerical and electronic models of individual neural behavior. Our experiments as a whole present interesting new examples of regularization and synchronization in coupled nonlinear oscillators.Comment: 26 pages, 10 figure

Courts, care proceedings and outcomes uncertainty: the challenges of achieving and assessing ‘good outcomes’ for children after child protection proceedings

The professed aim of any social welfare or legal intervention in family life is often to bring about ‘better outcomes for the children’. But there is considerable ambiguity about ‘outcomes’, and the term is far too often used in far too simplistic a way. This paper draws on empirical research into the outcomes of care proceedings for a randomly selected sample of 616 children in England and Wales, about half starting proceedings in 2009-10, and the others in 2014-15. The paper considers the challenges of achieving and assessing ‘good outcomes’ for the children. Outcomes are complex and fluid for all children, whatever the court order. One has to assess the progress of the children in the light of their individual needs and in the context of ‘normal’ child development; and in terms of the legal provisions and policy expectations. A core paradox is that some of the most uncertain outcomes are for children who remain with or return to their parents; yet law and policy require that first consideration is given to this option. Greater transparency about the uncertainty of outcomes is a necessary step towards better understanding the risks and potential benefits of care proceedings

Individual, Family and Abuse Characteristics of 700 British Child and Adolescent Sexual Abusers

The individual, family and abuse characteristics of 700 children and young people referred to nine UK services over a nine-year period between 1992 and 2000 as a result of their sexually abusive behaviours were examined. The most common age at referral was 15 years, though a third of all referrals related to children aged 13 or under. Thirty-eight per cent of the sample were identified as learning disabled. Surprisingly high rates of sexual and non-sexual victimisation were present in the backgrounds of the children and young people referred. A wide range of abusive behaviours was perpetrated with just over half of the sample having penetrated or having attempted to penetrate another individual. Victims were usually known to the abuser but in 75 per cent of cases were not related. Fifty-one per cent of the sample abused females only, though 49 per cent had at least one male victim. The implications for policy and practice with children and young people with harmful sexual behaviours are discussed

Multiple roles for membrane-associated protein trafficking and signaling in gravitropism

Gravitropism is a process that allows plant organs to guide their growth relative to the gravity vector. It requires them to sense changes in their orientation and generate a biochemical signal that they transmit to the tissues that drive organ curvature. Trafficking between the plasma membrane and endosomal compartments is important for all of these phases of the gravitropic response. The sedimentation of starch-filled organelles called amyloplasts plays a key role in sensing reorientation, and vacuolar integrity is required for amyloplast sedimentation in shoots. Other proteins associated with the vesicle trafficking pathway contribute to early gravity signal transduction independently of amyloplast sedimentation in both roots and hypocotyls. Phosphatidylinositol signaling, which starts at the plasma membrane and later affects the localization of auxin efflux facilitators, is a likely second messenger in the signal transduction phase of gravitropism. Finally, membrane-localized auxin influx and efflux facilitators contribute to a differential auxin gradient across the gravistimulated organs, which directs root curvature