Regulation of synaptic connectivity: levels of fasciclin II influence synaptic growth in the Drosophila CNS

Much of our understanding of synaptogenesis comes from studies that deal with the development of the neuromuscular junction (NMJ). Although well studied, it is not clear how far the NMJ represents an adequate model for the formation of synapses within the CNS. Here we investigate the role of Fasciclin II (Fas II) in the development of synapses between identified motor neurons and cholinergic interneurons in the CNS of Drosophila. Fas II is a neural cell adhesion molecule homolog that is involved in both target selection and synaptic plasticity at the NMJ in Drosophila. In this study, we show that levels of Fas II are critical determinants of synapse formation and growth in the CNS. The initial establishment of synaptic contacts between these identified neurons is seemingly independent of Fas II. The subsequent proliferation of these synaptic connections that occurs postembryonically is, in contrast, significantly retarded by the absence of Fas II. Although the initial formation of synaptic connectivity between these neurons is seemingly independent of Fas II, we show that their formation is, nevertheless, significantly affected by manipulations that alter the relative balance of Fas II in the presynaptic and postsynaptic neurons. Increasing expression of Fas II in either the presynaptic or postsynaptic neurons, during embryogenesis, is sufficient to disrupt the normal level of synaptic connectivity that occurs between these neurons. This effect of Fas II is isoform specific and, moreover, phenocopies the disruption to synaptic connectivity observed previously after tetanus toxin light chain-dependent blockade of evoked synaptic vesicle release in these neurons

Automatic estimation of flux distributions of astrophysical source populations

In astrophysics a common goal is to infer the flux distribution of populations of scientifically interesting objects such as pulsars or supernovae. In practice, inference for the flux distribution is often conducted using the cumulative distribution of the number of sources detected at a given sensitivity. The resulting "$\log(N>S)$-$\log (S)$" relationship can be used to compare and evaluate theoretical models for source populations and their evolution. Under restrictive assumptions the relationship should be linear. In practice, however, when simple theoretical models fail, it is common for astrophysicists to use prespecified piecewise linear models. This paper proposes a methodology for estimating both the number and locations of "breakpoints" in astrophysical source populations that extends beyond existing work in this field. An important component of the proposed methodology is a new interwoven EM algorithm that computes parameter estimates. It is shown that in simple settings such estimates are asymptotically consistent despite the complex nature of the parameter space. Through simulation studies it is demonstrated that the proposed methodology is capable of accurately detecting structural breaks in a variety of parameter configurations. This paper concludes with an application of our methodology to the Chandra Deep Field North (CDFN) data set.Comment: Published in at http://dx.doi.org/10.1214/14-AOAS750 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

The dark side of political marketing

Purpose This article discusses exploratory research into the perceptions of British Muslims towards Islamist ideological messaging to contribute to the general debate on ‘radicalisation'. The article discusses the findings of discussion groups in the light of research previously undertaken in the propaganda/psychology fields, from the perspective of Reversal Theory. Methodology/approach Four focus groups were undertaken with a mixture of Bangladeshi and Pakistani British Muslims who were shown a selection of Islamist propaganda media clips, garnered from the internet. The research is intended to provide exploratory indications of how British Muslims receive Islamist communication messages in order to provoke further research in this critical field. Findings We propose that Islamist communications focus on eliciting change in emotional states, specifically inducing the paratelic-excitement mode, by focusing around a meta-narrative of Muslims as a unitary grouping self- defined as victim to Western aggression. Early indicators are that some genres of Islamist propaganda may be more effective than others in generating these emotional change states (e.g. cartoons) and some groupings appear to be more susceptible than others. We conclude that our British Muslim respondents were unsympathetic to the Islamist ideological messaging contained in our sample of propaganda clips. Research limitations/implications The research highlights the difficulties in undertaking research in such a sensitive field. We propose a series of four testable propositions to guide future research looking specifically at whether those subjects who are more likely to be excited by Islamist communication include those with weakly held identities, younger males, those feeling contempt for Western culture, and the use of specific media genre formats. Originality/value of paper The article provides an insight into how British Muslims might respond to Islamist communications, indicating that whilst most are not susceptible to inducement of paratelic-excitement, others are likely to be, dependent on which genre of clip is used, the messages contained therein, and who that clip is targeted at

Low-temperature magnetic fluctuations in the Kondo insulator SmB6

We present the results of a systematic investigation of the magnetic properties of the three-dimensional Kondo topological insulator SmB6 using magnetization and muon-spin relaxation/rotation (muSR) measurements. The muSR measurements exhibit magnetic field fluctuations in SmB6 below 15 K due to electronic moments present in the system. However, no evidence for magnetic ordering is found down to 19 mK. The observed magnetism in SmB6 is homogeneous in nature throughout the full volume of the sample. Bulk magnetization measurements on the same sample show consistent behavior. The agreement between muSR, magnetization, and NMR results strongly indicate the appearance of intrinsic bulk magnetic in-gap states associated with fluctuating magnetic fields in SmB6 at low temperature.Comment: 5 pages, 5 figure

Death and best interests: a response to the legal challenge

In an earlier paper I argued that we do not have an objective conception of best interests and that this is a particular problem because the courts describe that they use an ‘…objective approach or test. That test is the best interests of the patient’ when choosing for children. I further argued that there was no obvious way in which we could hope to develop an objective notion of best interests. As well as this, I argued that a best-interest-based approach was a particular problem around the time of death of some children. A response from a legal perspective argued that, while there is not a clear conception of objective best interests, the courts have a well-described approach to finding a child's objective best interests. In this paper, I argue that without clear agreement on an objective conception of best interests, the courts are unable to locate an objective sense of best interests and that the solutions do not solve the problems that were identified in the initial paper ‘Death and best interests’

Meningococcal disease in children in Merseyside, England:a 31 year descriptive study

Meningococcal disease (MCD) is the leading infectious cause of death in early childhood in the United Kingdom, making it a public health priority. MCD most commonly presents as meningococcal meningitis (MM), septicaemia (MS), or as a combination of the two syndromes (MM/MS). We describe the changing epidemiology and clinical presentation of MCD, and explore associations with socioeconomic status and other risk factors. A hospital-based study of children admitted to a tertiary children's centre, Alder Hey Children's Foundation Trust, with MCD, was undertaken between 1977 to 2007 (n = 1157). Demographics, clinical presentations, microbiological confirmation and measures of deprivation were described. The majority of cases occurred in the 1-4 year age group and there was a dramatic fall in serogroup C cases observed with the introduction of the meningococcal C conjugate (MCC) vaccine. The proportion of MS cases increased over the study period, from 11% in the first quarter to 35% in the final quarter. Presentation with MS (compared to MM) and serogroup C disease (compared to serogroup B) were demonstrated to be independent risk factors for mortality, with odds ratios of 3.5 (95% CI 1.18 to 10.08) and 2.18 (95% CI 1.26 to 3.80) respectively. Cases admitted to Alder Hey were from a relatively more deprived population (mean Townsend score 1.25, 95% CI 1.09 to 1.41) than the Merseyside reference population. Our findings represent one of the largest single-centre studies of MCD. The presentation of MS is confirmed to be a risk factor of mortality from MCD. Our study supports the association between social deprivation and MCD

Controlling magnetic order and quantum disorder in molecule-based magnets

We investigate the structural and magnetic properties of two molecule-based magnets synthesized from the same starting components. Their different structural motifs promote contrasting exchange pathways and consequently lead to markedly different magnetic ground states. Through examination of their structural and magnetic properties we show that [Cu(pyz)(H2O)(gly)2](ClO4)2 may be considered a quasi-one-dimensional quantum Heisenberg antiferromagnet whereas the related compound [Cu(pyz)(gly)](ClO4), which is formed from dimers of antiferromagnetically interacting Cu2+ spins, remains disordered down to at least 0.03 K in zero field but shows a field-temperature phase diagram reminiscent of that seen in materials showing a Bose-Einstein condensation of magnons

Assent for children's participation in research is incoherent and wrong

When children are considered for participation in research, British and international guidelines suggest that they should provide assent in addition to their parents' consent. However, examination of these guidelines shows there is confusion regarding the concept of assent. Furthermore, the need for assent may cause problems. The guidelines should be revised: the parents of incompetent children should consent for them and competent children should consent on their own behalf

Technological impacts on market attitudes and behaviors

Technology has had a profound effect on twentieth century society and is increasingly changing the nature of the way we live our lives in the twenty first century, particularly, but not solely, through innovations in digital and social media marketing. As media and other technologies change, the question arising concerns how these changes impact on consumers’ attitudes and behaviors, and consequently on their lives. In this special edition, nine papers are presented, outlining cutting-edge research exploring how changing technologies affect consumer attitudes, emotions and behaviors in a variety of country settings and industries. In this introductory editorial, the papers are outlined in further detail, with a brief exposition of their contribution