A fully-coherent all-sky search for gravitational-waves from compact binary coalescences

We introduce a fully-coherent method for searching for gravitational wave signals generated by the merger of black hole and/or neutron star binaries. This extends the coherent analysis previously developed and used for targeted gravitational wave searches to an all-sky, all-time search. We apply the search to one month of data taken during the fifth science run of the LIGO detectors. We demonstrate an increase in sensitivity of 25% over the coincidence search, which is commensurate with expectations. Finally, we discuss prospects for implementing and running a coherent search for gravitational wave signals from binary coalescence in the advanced gravitational wave detector data.Comment: 17 pages, 12 figure

Avoiding unseen obstacles : Subcortical vision is not sufficient to maintain normal obstacle avoidance behaviour during reaching

Acknowledgement This work was funded by the RS MacDonald Charitable Trust (awarded to C. Hesse in June 2013). T. Schenk was supported by a grant from the German Research Council (DFG – SCHE 735/3-1). The authors would like to thank Dr Stefanie Biehl for her valuable advice on lesion localisation based on the CT and MRI scans of the patients. We would also like to thank all the patients for taking part in our experiments and for giving up so much of their free time.Peer reviewedPostprin

Psycho-medical discourse in South African research on teenage pregnancy

Catriona Macleod and Kevin Durrheim apply a Foucauldian analysis to the scientific literature on teenage pregnancy

The roles of resident, central and effector memory CD4 T cells in protective immunity following infection or vaccination

Immunological memory provides rapid protection to pathogens previously encountered through infection or vaccination. CD4 T cells play a central role in all adaptive immune responses. Vaccines must, therefore, activate CD4 T cells if they are to generate protective immunity. For many diseases, we do not have effective vaccines. These include HIV, tuberculosis and malaria, which are responsible for many millions of deaths each year across the globe. CD4 T cells play many different roles during the immune response coordinating the actions of many other cells. In order to harness the diverse protective effects of memory CD4 T cells we need to understand how memory CD4 T cells are generated and how they protect the host. Here we review recent findings on the location of different subsets of memory CD4 T cells that are found in peripheral tissues (tissue resident memory T cells) and in the circulation (central and effector memory T cells). We discuss the generation of these cells and the evidence that demonstrates how they provide immune protection in animal and human challenge models

The conjugalisation of reproduction in South African teenage pregnancy literature

The “conjugalisation of reproduction”, in which childbearing is legitimated only within a marital alliance, underlies some of the pathologisation of the single, female-headed household in the pre-democracy South African teenage pregnancy literature. I utilise a poststructural feminist framework that draws on elements of Derrida’s and Foucault’s work to analyse the conjugalisation of reproduction in South African research. The conjugalisation of reproduction relies on (1) the insidious “unwed” signifier which interpenetrates the term “teenage pregnancy”, allowing the scientific censure of non-marital adolescent re-production without the invocation of moralisation, and (2) the fixation of the husband-wife and parents-children axes of alliance as the main elements for the deployment of sexuality and reproduction in the form of the family. Pregnant teenagers are, in Derridean terms, undecidables: they are neither children (owing to their reproductive status) nor adults (owing to their age), but simultaneously both. Marriage is the authority that decides them, allowing them to join the ranks of adult reproductive subjects

The new moral order and racism in South Africa post 11 September 2001

In this paper we argue that globalisation imposes on ‘developing’ countries more than an economic order; they find themselves with the moral imperative to align themselves with the West against its Others, increasingly portrayed as Islamic fundamentalists. The 11 September terror attacks in the United States of America have pushed this process to a new level, with the attacks represented as no less than a barbaric attack on ‘civilisation’. Through an analysis of a newspaper article reporting on the disciplining of a Muslim woman in for wearing an Osama Bin Laden t-shirt to work in South Africa, we indicate how this moral representation of the 11 September events and the Islamic Other have unique local effects. In South Africa it creates yet more possibilities for racialising practices to continue without being framed in explicitly racial terms. We further reflect on the implications of these events, and the complex interplay of the global and the local they demonstrate, for critical psychology in South Africa

The chaotic solar cycle II. Analysis of cosmogenic 10Be data

Context. The variations of solar activity over long time intervals using a solar activity reconstruction based on the cosmogenic radionuclide 10Be measured in polar ice cores are studied. Methods. By applying methods of nonlinear dynamics, the solar activity cycle is studied using solar activity proxies that have been reaching into the past for over 9300 years. The complexity of the system is expressed by several parameters of nonlinear dynamics, such as embedding dimension or false nearest neighbors, and the method of delay coordinates is applied to the time series. We also fit a damped random walk model, which accurately describes the variability of quasars, to the solar 10Be data and investigate the corresponding power spectral distribution. The periods in the data series were searched by the Fourier and wavelet analyses. The solar activity on the long-term scale is found to be on the edge of chaotic behavior. This can explain the observed intermittent period of longer lasting solar activity minima. Filtering the data by eliminating variations below a certain period (the periods of 380 yr and 57 yr were used) yields a far more regular behavior of solar activity. A comparison between the results for the 10Be data with the 14C data shows many similarities. Both cosmogenic isotopes are strongly correlated mutually and with solar activity. Finally, we find that a series of damped random walk models provides a good fit to the 10Be data with a fixed characteristic time scale of 1000 years, which is roughly consistent with the quasi-periods found by the Fourier and wavelet analyses.Comment: 8 pages, 11 figure

(Dis)allowances of lesbians’ sexual identities: Lesbian identity construction in racialised, classed, familial, and institutional spaces

This article explores how lesbian identity construction is facilitated and constrained by the raced, classed, gendered, familial, and geographical spaces that women occupy. We present a narrative-discursive analysis of eight lesbians’ stories of sexuality, told within a historically white university in South Africa. Three interpretative repertoires that emerged in the narratives are discussed. The ‘disallowance of lesbian identity in particular racialised and class-based spaces’ repertoire, deployed by black lesbians only, was used to account for their de-emphasis of a lesbian identity through the invocation of a threat of danger and stereotyping. The ‘disjuncture of the (heterosexual) family and lesbian identity’ repertoire emphasised how the expectation of support and care within a family does not necessarily extend to acceptance of a lesbian identity

Improved methods for detecting gravitational waves associated with short gamma-ray bursts

In the era of second generation ground-based gravitational wave detectors, short gamma-ray bursts (GRBs) will be among the most promising astrophysical events for joint electromagnetic and gravitational wave observation. A targeted search for gravitational wave compact binary merger signals in coincidence with short GRBs was developed and used to analyze data from the first generation LIGO and Virgo instruments. In this paper, we present improvements to this search that enhance our ability to detect gravitational wave counterparts to short GRBs. Specifically, we introduce an improved method for estimating the gravitational wave background to obtain the event significance required to make detections; implement a method of tiling extended sky regions, as required when searching for signals associated to poorly localized GRBs from Fermi Gamma-ray Burst Monitor or the InterPlanetary Network; and incorporate astrophysical knowledge about the beaming of GRB emission to restrict the search parameter space. We describe the implementation of these enhancements and demonstrate how they improve the ability to observe binary merger gravitational wave signals associated with short GRBs.Comment: 13 pages, 6 figure