Adults are more efficient in creating and transmitting novel signalling systems than children

Iterated language learning experiments have shown that meaningful and structured signalling systems emerge when there is pressure for signals to be both learnable and expressive. Yet such experiments have mainly been conducted with adults using language-like signals. Here we explore whether structured signalling systems can also emerge when signalling domains are unfamiliar and when the learners are children with their well-attested cognitive and pragmatic limitations. In Experiment 1, we compared iterated learning of binary auditory sequences denoting small sets of meanings in chains of adults and 5-7-year old children. Signalling systems became more learnable even though iconicity and structure did not emerge despite applying a homonymy filter designed to keep the systems expressive. When the same types of signals were used in referential communication by adult and child dyads in Experiment 2, only the adults, but not the children, were able to negotiate shared iconic and structured signals. Referential communication using their native language by 4-5-year old children in Experiment 3 showed that only interaction with adults, but not with peers resulted in informative expressions. These findings suggest that emergence and transmission of communication systems is unlikely to be driven by children, and point to the importance of cognitive maturity and pragmatic expertise of learners as well as feedback-based scaffolding of communicative effectiveness by experts during language evolution

Optical Rogue Waves in Vortex Turbulence

We present a spatio-temporal mechanism for producing 2D optical rogue waves in the presence of a turbulent state with creation, interaction and annihilation of optical vortices. Spatially periodic structures with bound phase lose stability to phase unbound turbulent states in complex Ginzburg- Landau and Swift-Hohenberg models with external driving. When the pumping is high and the external driving is low, synchronized oscillations are unstable and lead to spatio-temporal turbulence with high excursions in amplitude. Nonlinear amplification leads to rogue waves close to turbulent optical vortices, where the amplitude tends to zero, and to probability distribution functions with long tails typical of extreme optical events.Comment: 5 pages, 7 figure

A Scarlet Ending

Dancing a duet with my shadow by integrating dance and digital media in an elaborate and entertaining performance

Exploring children’s perceptions of their local environment in relation to time spent outside

This study aims to understand how children perceive their environment, exploring the affordances children perceive to influence their physical activity (PA) behaviour when outside. Participants included boys and girls aged 10–12 years (n = 15) living in Scotland. Children's visual and verbal representations of their perceived environment were analysed to assess environmental determinants of PA. The findings suggested that physical affordances that offer a sense of risk were important to children's play spaces. Social affordances influenced where the children went in their environment and the features they utilised as part of play behaviour; strangers were considered threatening depending on whether the activity was recognised

Unlocking the potential of anti-CD33 therapy in adult and childhood acute myeloid leukaemia

Acute Myeloid Leukaemia (AML) develops when there is a block in differentiation and uncontrolled proliferation of myeloid precursors, resulting in bone marrow failure. AML is a heterogeneous disease clinically, morphologically, and genetically, and biological differences between adult and childhood AML have been identified. AML comprises 15-20% of all children less than fifteen years diagnosed with acute leukaemia. Relapse occurs in up to 40% of children with AML and is the commonest cause of death.1,2 Relapse arises from leukaemic stem cells (LSCs) that persist after conventional chemotherapy. The treatment of AML is challenging and new strategies to target LSCs are required. The cell surface marker CD33 has been identified as a therapeutic target, and novel anti-CD33 immunotherapies are promising new agents in the treatment of AML. This review will summarise recent developments emphasising the genetic differences in adult and childhood AML, while highlighting the rationale for CD33 as a target for therapy, in all age groups

The Influence of the Endothelium on the Response of Vascular Smooth Muscle

This project was carried out to examine the influence of the vascular endothelium on the responses of the underlying smooth muscle. I have examined the influence of the endothelium on sensitivity of the smooth muscle to calcium and the interaction of a Ca2+-channel activator and blocker. A further study was carried out to examine how the initial tone affects the responses to both contractile and relaxatory agents and how the size of the induced tone affects the ability of Ach to cause relaxation. I studied the changes, if any, in this relationship in certain cardiovascular diseases. These effects were studied in an isolated aortic ring from the rat and also a complete vascular bed, the perfused rat tail. The following is a summary of the results: 1) Removal of the vascular endothelium from isolated aortic rings affects the sensitivity of the tissue to various agonists. The influence on the responses is greater for some agonists than for others. The agonists influenced to the greatest extent had both the pD2 and the maximum response significantly changed by removal of the endothelium: these agonists were either alpha1-adrenoceptor partial agonists or alpha2-adrenoceptor agonists in other tissues. The agonist affected to the least extent, the thromboxane mimetic drug U46619 showed no significant change on removal of the endothelium in either the maximum response or the pD2 value. 2) The presence of the vascular endothelium had no influence on the actions at alpha1-adrenoceptors, of the selective antagonists prazosin and corynanthine, or the alpha2-adrenoceptor antagonist, Wyeth 26703. The results using Wyeth 26703 did not support the possibility of alpha2-adrenoceptor stimulation releasing EDRF, since it had the same effect on responses to NA in tissues with both an intact and disrupted endothelium. 3) Increasing the initial length in aortic ring segments caused a length-dependent increase in the resting tension. The absence of the endothelium had no significant effect on the resting tensions compared with intact tissues. The size of the contraction to Phe (1uM) and relaxation to Ach (1uM) (tone induced by Phe) were dependent on the initial length of the preparation. The optimum stretch to demonstrate the proportionate effect of Ach (1uM) did not coincide with the optimum for Phe-induced contractions. 4) The size of the induced tone against which Ach produced relaxation affected the sensitivity to this agent. The greater the size of the induced tone the less sensitive the tissue was to relaxation. Atropine did not affect the size of the tone induced by NA but inhibited the relaxation to Ach. BAY-K 8644, a calcium channel facilitator, increased the tone induced by NA and inhibited the relaxation to Ach to a greater extent than would be expected by increase in tone alone. The cx2-antagonist drug Wyeth 26703, at concentrations where it acts selectively at alpha2-adrenoceptors (in other tissues), had no effect on NA-induced tone or on Ach-induced relaxation. 5) Using a maximal concentration of NA (3uM) in rat aortic rings, with either an intact or disrupted endothelium, in both a buffered and unbuffered calcium system, the contractile response was shown to be dependent on the concentration of extracellular calcium. At concentrations of calcium greater than 1.25mM the response started to fall off. This response was not potentiated using either system in the presence of BAY-K 8644 (1uM) but was significantly inhibited in the presence of nifedipine (1muM). 6) Using a submaximal concentration of NA (30nM) in the rat aortic rings either intact or disrupted, in an unbuffered system, again the response was shown to be dependent on the concentration of extracellular calcium. In this system the responses to NA (30nM) were potentiated by BAY-K 8644 (1-100nM). The potentiation was similar regardless of the presence of the endothelium and reached a maximum at BAY-K (10nM). In the presence of this drug the drop in maximum response at high concentrations of calcium was still evident. 7) In the presence of nifedipine (0.1-1muM) the responses to NA (30nM) were inhibited to a similar extent in both intact and disrupted rings. With this drug the drop in the maximum response at high calcium concentrations was not seen

Asset-based and citizen-led development : using a diffracted power lens to analyze the possibilities and challenges

Asset-based community development or Asset-based and citizen-led development (ABCD) is being used in a range of development contexts. Some researchers have been quick to dismiss ABCD as part of the neoliberal project and an approach that perpetuates unequal power relations. This article uses a diffracted power analysis to explore the possibilities associated with ABCD as well as the challenges. It focuses on the application of ABCD in the Philippines, Ethiopia and South Africa, and finds that ABCD can reverse internalized powerlessness, strengthen opportunities for collective endeavours and help to build local capacity for action

UK university fundraising : an analysis of inequality and its perpetuation

PhD ThesisInequality in UK society has emerged as one of the key themes in contemporary British politics, despite more than 50 years of government policy geared towards its reduction. UK universities have been tasked with the societal mission of enabling social mobility and reducing inequality, and their number, and the size of their student bodies has grown significantly since 1992. Neoliberalism has marketized and largely privatised the UK higher education sector, yet it attracts more than £1billion in philanthropic support annually. Much work has been done in the US to understand universities, philanthropy, and the process of raising funds. This study presents the results of the first academic work to examine how private philanthropy acts at universities in the UK, and how it impacts their function in society. Using publicly available information for the sector, and by examining in depth 11 universities of greatly differing heritage and wealth, this study uses quantitative and qualitative techniques to elucidate and explain the degree of inequality present among UK universities, and philanthropy’s role in its genesis and perpetuation. It identifies a link between university reputation and ability to attract philanthropic support, and explains how elite universities are able to apply their very large philanthropic incomes to enhance the endowments of personal capital of their students, thereby maintaining their dominance over other, less well endowed, universities. It critically reviews how universities view philanthropy and how fundraising functions are constituted in university organisations. By identifying and challenging the myths of university functions and fundraising, it explains why government policy has not succeeded in replicating US levels of philanthropic support for UK universities. Applying Bourdieusian sociology, new institutional theory and the strategy literature, this study enhances our understanding of how social processes act to conserve the status quo, even as powerful actors seek to enact change

Allelic segregation and independent assortment in <i>T. brucei</i> crosses: proof that the genetic system is Mendelian and involves meiosis

The genetic system on Trypanosoma brucei has been analysed by generating large numbers of independent progeny clones from two crosses, one between two cloned isolates of Trypanosoma brucei brucei and one between cloned isolates of T. b. brucei and Trypanosoma brucei gambiense, Type 2. Micro and minisatellite markers (located on each of the 11 megabase housekeeping chromosomes) were identified, that are heterozygous in one or more of the parental strains and the segregation of alleles at each locus was then determined in each of the progeny clones. The results unequivocally show that alleles segregate in the predicted ratios and that alleles at loci on different chromosomes segregate independently. These data provide statistically robust proof that the genetic system is Mendelian and that meiosis occurs. Segregation distortion is observed with the minisatellite locus located on chromosome I of T. b. gambiense Type 2 and neighboring markers, but analysis of markers further along this chromosome did not show distortion leading to the conclusion that this is due to selection acting on one part of this chromosome. The results obtained are discussed in relation to previously proposed models of mating and support the occurrence of meiosis to form haploid gametes that then fuse to form the diploid progeny in a single round of mating