A study of zinc resistance and accumulation of zinc in scapania undulata (L) Dum

Scapania undulata (L.) Dum. is a bryophyte which is common in the upland streams of the North East of England. The zinc resistance of S. undulata from zinc enriched and from low zinc sites was investigated by means of laboratory toxicity tests and field transplants. The results obtained do not suggest that the populations of S. undulata at the zinc enriched sites studied are genetically adapted, zinc resistant ecotypes of the species. The enrichment ratio of zinc in S. undulata at a number of sites was investigated and considerable variation between sites was found. The effects of the concentration of zinc in the medium, light and temperature on the uptake of zinc by S. undulata under aboratory conditions were also investigated. The rate of uptake of zinc was found to increase as the concentration of zinc in the medium increased, up to a concentration of 60 mg 1(^-1). The saturation point was found to be approximately the same for a two day period as for the initial half hour, with some indication of ^ small increase In the rate of uptake of zinc at concentrations greater than 60 mg 1(^-1) over the two-day period. Material incubated in medium containing 1 mg 1(^-1) zinc in the light for a period of four days was found to contain approximately 15% more zinc than material incubated in darkness. The rate of uptake of zinc by dead material at 32 ºC from medium containing 2 mg 1(^-1) zinc was found to be greater than that of live material at 14 ºC and there was some indication of a greater rate of uptake by live material at 24ºC than at l4 ºC. The results of these experiments are discussed in terms of the relative importance's of active and passive mechanisms of uptake of zinc in S. undulata and the validity of using this species for monitoring the levels of zinc in stream waters

Chatting with chatbots: Sign making in text-based human–computer interaction

This paper investigates the kind of sign making that goes on in text-based human–computer interaction, between human users and chatbots, from the point of view of integrational linguistics. A chatbot serves as a “conversational” user interface, allowing users to control computer programs in “natural language”. From the user’s perspective, the interaction is a case of semiologically integrated activity, but even if the textual traces of a chat may look like a written conversation between two humans the correspondence is not one-to-one. It is argued that chatbots cannot engage in communication processes, although they may display communicative behaviour. They presuppose a (second-order) language model, they can only communicate at the level of sentences, not utterances, and they implement communicational sequels by selecting from an inventory of executable skills. Instead of seeing them as interlocutors in silico, chatbots should be seen as powerful devices for humans to make signs with.    &nbsp

On Writing Neo-Victorian Fiction: \u3ci\u3eJames Miranda Barry \u3c/i\u3e(1999) and \u3ci\u3eSophie and the and the Sibyl: A Victorian Romance\u3c/i\u3e (2015)

This is the text of the Forty-Fourth George Eliot Memorial Lecture delivered at the Chilvers Coton Heritage Centre on 10 October, 2015. An extended version of this article will appear in late 2016 or early 2017 as an interview/essay in the series \u27anglistik & englischunterricht\u27: Christina Flotmann and Anna Lienen (eds.), Victorian Ideologies in Contemporary British Culture, Heidelberg: Winter Verlag. My first historical novel - lames Miranda Barry (1999) was not born a Neo-Victorian novel, but became one. And it had a very personal link to my own life. Barry was a nineteenth-century colonial doctor and medical reformer, who had a very successful and colourful career in remote parts of the Empire. He spent an important period of his life in Jamaica, then a British colony, during the 1830s, taking care of the army garrison stationed on the island to protect the interests of the Crown and put down the numerous slave revolts. The British maintained a regiment there until the island\u27s independence on 6 August 1962. I come from Jamaica: my father was Jamaican and my mother is English. Our house in the Blue Mountains near Greenwich, where the army barracks was situated, had been built by my father on the foundations of the old colonial barracks constructed by Dr James Barry to acclimatize the troops, so that they did not all die from yellow fever upon their arrival on the island . But 1 didn \u27t know that when I began my work on Barry. What interested me was the rumour that leaked out when Barry died in the early 1870s, that he was in fact, a woman. But was he? Which brings me to my second historical novel, Sophie and the Sibyl: A Victorian Romance (Bloomsbury, 2015), which, this time is quite self-consciously written as a NeoVictorian Novel, in awareness that this particular genre has a literary history and an associated, developing body of criticism. Hallucinating Foucault represented two writers, one fictional and the other an historical character, the philosopher Michel Foucault. This time, in Sophie and the Sibyl, I decided to settle my scores with the Victorian writer I most admire, cherish, re-read and adore: Marian Evans Lewes, better known, but never addressed, or described, except in letters, as George Eliot. George Eliot is a textual rather than a lived identity. Oddly enough, Eliot herself, like Barry, although not in the same way, was both man and woman. The magisterial voice of her narrators is often, but not always, masculine. She relished her male pseudonym, while her identity remained secret, and she assumed a male voice in her writing for the Westminster Review. Her writing name has never been abandoned. For us, her readers now, Marian Evans Lewes is never named as the author of Middlemarch. The person who wrote the books is still George Eliot

Dynamical structure in neural population activity

The question of how the collective activity of neural populations in the brain gives rise to complex behaviour is fundamental to neuroscience. At the core of this question lie considerations about how neural circuits can perform computations that enable sensory perception, motor control, and decision making. It is thought that such computations are implemented by the dynamical evolution of distributed activity in recurrent circuits. Thus, identifying and interpreting dynamical structure in neural population activity is a key challenge towards a better understanding of neural computation. In this thesis, I make several contributions in addressing this challenge. First, I develop two novel methods for neural data analysis. Both methods aim to extract trajectories of low-dimensional computational state variables directly from the unbinned spike-times of simultaneously recorded neurons on single trials. The first method separates inter-trial variability in the low-dimensional trajectory from variability in the timing of progression along its path, and thus offers a quantification of inter-trial variability in the underlying computational process. The second method simultaneously learns a low-dimensional portrait of the underlying nonlinear dynamics of the circuit, as well as the system's fixed points and locally linearised dynamics around them. This approach facilitates extracting interpretable low-dimensional hypotheses about computation directly from data. Second, I turn to the question of how low-dimensional dynamical structure may be embedded within a high-dimensional neurobiological circuit with excitatory and inhibitory cell-types. I analyse how such circuit-level features shape population activity, with particular focus on responses to targeted optogenetic perturbations of the circuit. Third, I consider the problem of implementing multiple computations in a single dynamical system. I address this in the framework of multi-task learning in recurrently connected networks and demonstrate that a careful organisation of low-dimensional, activity-defined subspaces within the network can help to avoid interference across tasks

Review of Sophie and the Sibyl: A Victorian Romance

George Eliot\u27s afterlife in adaptations of and sequels to her works is thin compared to those of such contemporaries as Dickens and the Brontes, and similarly the number of novels in which she appears as a character is meagre. True, as early as 1881 the characterization of Theresa in The Autobiography of Mark Rutherford was inspired by the friendship of its author, William Hale White, with Marian Evans in the 1850s, when both lived in publisher John Chapman\u27s house at 142 Strand. Theresa is an idealized character, but recall White\u27s corrective to George Eliot\u27s Life ... by her husband 1. W Cross, in which he laments the absence of salt and spice in the Marian Evans that Cross is carefully recreating. Patricia Duncker, offering George Eliot as the Sibyl in Sophie and the Sibyl: A Victorian Romance, the latest novel to depict her, goes rather for salt and vinegar. Between White and Duncker there has been a smattering of fictional representations of George Eliot. Some, like J. E. Buckrose\u27s Silhouette of Mary Ann (1931) and Elfrida Vipont\u27s Towards a High Attic: The Early Life of George Eliot (1970), concentrate on the young Marian Evans, up to the point at which she enters into the relationship with Lewes and becomes George Eliot and a published author. Others focus on the relationship with John Cross, which is more susceptible to psychologizing and less to anxious moralizing than that with Lewes. In lohnnie Cross (1983), Terence de Vere White presents an infantilized Cross, overwhelmed by his bride\u27s sexual demands. In one of the episodes of The Puttermesser Papers (1997), Cynthia Ozick allows her heroine Ruth Puttermesser a romance with a painter, a copyist, in which she channels George Eliot and he Cross: the copyist insists that the key emotional dynamic was Cross\u27s infatuation with Lewes, triangulated through George Eliot. Deborah Weisgall in The World Before Her (2008) makes Cross a staid but devoted businessman, and George Eliot more wily and less dependent than in most accounts, fictional or otherwise. Most recently, Robert Muscutt in Heathen and Outcast: Scenes in the Life of George Eliot (2011) employs the novelist\u27s disciple Edith Simcox as presiding narrator, calling on other voices to show a feisty Mary Ann, making central her relationship with brother Isaac (here relentlessly rigid, domineering, vindictive and materialistic)

On Writing Neo-Victorian Fiction: James Miranda Barry (1999) and Sophie and The Sibyl: A Victorian Romance (2015)

My first historical novel - James Miranda Barry (1999) was not born a Neo-Victorian novel, but became one. And it had a very personal link to my own life. Barry was a nineteenth-century colonial doctor and medical reformer, who had a very successful and colourful career in remote parts of the Empire. He spent an important period of his life in Jamaica, then a British colony, during the 1830s, taking care of the army garrison stationed on the island to protect the interests of the Crown and put down the numerous slave revolts. The British maintained a regiment there until the island\u27s independence on 6 August 1962. I come from Jamaica: my father was Jamaican and my mother is English. Our house in the Blue Mountains near Greenwich, where the army barracks was situated, had been built by my father on the foundations of the old colonial barracks constructed by Dr James Barry to acclimatize the troops, so that they did not all die from yellow fever upon their arrival on the island. But I didn’t know that when I began my work on Barry. What interested me was the rumour that leaked out when Barry died in the early 1870s, that he was in fact, a woman. But was he? No one knows what sex Barry actually was. His recent biographer, Rachel Holmes, argues that he was a hermaphrodite.\u27 We would now perhaps describe him as a transgender individual, but we cannot ever know for certain. Whatever he was, he certainly gave a command performance. So my theme was the dramatic interrogation of gender and identity. I decided to create a character that was neither man nor woman, but drew on both roles, sometimes of necessity and sometimes for his own pleasure. I wanted to create someone who was isolated, secretive, trapped inside his own head, and yet absolutely at liberty to be whoever he chose to be. The impulse behind this re-imagining of Dr James Miranda Barry came from my own unease at the roles being offered to me as a woman

Towards In Vivo Imaging of Cancer Sialylation

In vivo assessment of tumor glucose catabolism by positron emission tomography (PET) has become a highly valued study in the medical management of cancer. Emerging technologies offer the potential to evaluate in vivo another aspect of cancer carbohydrate metabolism related to the increased anabolic use of monosaccharides like sialic acid (Sia). Sia is used for the synthesis of sialylated oligosaccharides in the cell surface that in cancer cells are overexpressed and positively associated to malignancy and worse prognosis because of their role in invasion and metastasis. This paper addresses the key points of the different strategies that have been developed to image Sia expression in vivo and the perspectives to translate it from the bench to the bedside where it would offer the clinician highly valued complementary information on cancer carbohydrate metabolism that is currently unavailable in vivo

The question of sustainability

The question of sustainabilit

Dynamics on the manifold: Identifying computational dynamical activity from neural population recordings

The question of how the collective activity of neural populations gives rise to complex behaviour is fundamental to neuroscience. At the core of this question lie considerations about how neural circuits can perform computations that enable sensory perception, decision making, and motor control. It is thought that such computations are implemented through the dynamical evolution of distributed activity in recurrent circuits. Thus, identifying dynamical structure in neural population activity is a key challenge towards a better understanding of neural computation. At the same time, interpreting this structure in light of the computation of interest is essential for linking the time-varying activity patterns of the neural population to ongoing computational processes. Here, we review methods that aim to quantify structure in neural population recordings through a dynamical system defined in a low-dimensional latent variable space. We discuss advantages and limitations of different modelling approaches and address future challenges for the field

A sanitation technology demonstration centre to enhance decision making in South Africa

Limited understanding of the characteristics of different sanitation technology options may affect acceptance of certain technologies in certain circumstances, as well as lead to little appreciation by the users of the long-term financial, environmental and institutional implications of operating and maintaining the various sanitation systems. In South Africa, this has resulted in disturbing increases in the numbers of poorly operated and maintained sanitation technologies across South Africa. The need to establish a facility where people could acquaint themselves with the various sanitation systems was recognised by the CSIR and WRC who made funding available for the establishment of the Sanitation Technology Demonstration Centre at the CSIR. This Centre is aimed at informing local, provincial and national authority officials, NGO’s, CBO’s, consultants, schools, universities, and importantly, communities themselves in order for them to make informed and educated decisions and choices regarding sanitation technologies