The stratigraphical distribution of Mid-Cretaceous foraminifera near Ventor, Isle of Wight

Ventnor No. 2 Borehole, located near Ventnor, Isle of Wight, penetrated the basal part of the Chalk Group and the Selborne Group before terminating in the upper part of the Lower Greensand Group (Sandrock Formation). The borehole was examined for Foraminifera, and although they were not seen in the Sandrock Formation and Monks Bay Sandstone Formation, the remainder of the borehole yielded moderately low diversity assemblages dominated by agglutinated species. Foraminiferal zones 3–6 (H dentatus to M. fallax/M. rostratum macrofaunal zones) were identified in the Gault Formation and zones 6 (lower) to 6a (M. fallax/M. rostratum to A. briacensis macrofaunal zones) were identified in the Upper Greensand Formation. Assemblages from the overlying West Melbury Marly Chalk Formation were used to identify foraminiferal zones BGS1-BGS3 (M. mantelli and M. dixoni macrofaunal zones)

Dark Matter In Disk Galaxies II: Density Profiles as Constraints on Feedback Scenarios

The disparity between the density profiles of galactic dark matter haloes predicted by dark matter only cosmological simulations and those inferred from rotation curve decomposition, the so-called cusp-core problem, suggests that baryonic physics has an impact on dark matter density in the central regions of galaxies. Feedback from black holes, supernovae and massive stars may each play a role by removing matter from the centre of the galaxy on shorter timescales than the dynamical time of the dark matter halo. Our goal in this paper is to determine constraints on such feedback scenarios based on the observed properties of a set of nearby galaxies. Using a Markov Chain Monte Carlo (MCMC) analysis of galactic rotation curves, via a method developed in a previous paper, we constrain density profiles and an estimated minimum radius for baryon influence, $r_1$, which we couple with a feedback model to give an estimate of the fraction of matter within that radius that must be expelled to produce the presently observed halo profile. We show that in the case of the gas rich dwarf irregular galaxy DDO 154, an outflow from a central source (e.g. a black hole or star forming region) could produce sufficient feedback on the halo without removing the disk gas. We examine the rotation curves of 8 galaxies taken from the THINGS data set and determine constraints on the radial density profiles of their dark matter haloes. For some of the galaxies, both cored haloes and cosmological $\rho \propto r^{-1}$ cusps are excluded. These intermediate central slopes require baryonic feedback to be finely tuned. We also find for galaxies which exhibit extended cores in their haloes (e.g. NGC 925), the use of a split power-law halo profile yields models without the unphysical, sharp features seen in models based on the Einasto profile.Comment: 17 pages, 19 figures Submitted to MNRA

Localising fast radio bursts and other transients using interferometric arrays

A new population of sources emitting fast and bright transient radio bursts has recently been identified. The observed large dispersion measure values of FRBs suggests an extragalactic origin and an accurate determination of their positions and distances will provide an unique opportunity to study the magneto-ionic properties of the IGM. So far, FRBs have all been found using large dishes equipped with multi-pixel arrays. While large single dishes are well-suited for the discovery of transient sources they are poor at providing accurate localisations. A 2D snapshot image of the sky, made with a correlation interferometer array, can provide an accurate localisation of many compact radio sources simultaneously. However, the required time resolution to detect FRBs and a desire to detect them in real time, makes this currently impractical. In a beamforming approach, where many narrow tied-array beams are produced, the advantages of single dishes and interferometers can be combined. We present a proof-of-concept analysis of a new non-imaging method that utilises the additional spectral and comparative spatial information obtained from multiple overlapping TABs to estimate a transient source location with up to arcsecond accuracy in almost real time. We show that this method can work for a variety of interferometric configurations, including for LOFAR and MeerKAT, and that the estimated angular position may be sufficient to identify a host galaxy without reference to other simultaneous or follow-up observations. With this method, many transient sources can be localised to small fractions of a HPBW of a TAB, in the case of MeerKAT, sufficient to localise a source to arcsecond accuracy. In cases where the position is less accurately determined we can still significantly reduce the area that need be searched for associated emission at other wavelengths and potential host galaxies.Comment: 17 pages, 12 figures, accepted for publication in the Astronomy and Astrophysics journal, updated Table

Straddling realities: The urban foundation and social change in contemporary South Africa

African Studies Seminar series. Paper presented May 1982Until perhaps as recently as a year ago, it would have been tempting to construct a 'radical' critique of the Urban Foundation (UF) around the apparent compatibility of the organization's programme with the objectives of the 'Total Strategy' formulated by the government of P.W. Botha. Indeed, elements of such an analysis remain central to the argument that will be advanced here. But since the events of the past year have exposed the deep-seated antipathy of an important section of the government's electoral base towards any attempt at 'meaningful reform', the inadequacy of a critique which simply continues to assert the UF's complicity in 'Total Strategy' must be confronted. After the recent much-heralded 'report back' conference between Botha and leading businessmen fizzled out inconclusively in Cape Town, it would be merely naive to attempt to maintain the notion of an unpvoblematic partnership of 'state' and 'capital' in a joint project aimed at co-opting the black 'middle classes' under the guise of implementing an essentially hollow reform strategy. What I shall be trying to do in this article, therefore, is to shift the analysis of the UFVs role in contemporary South Africa beyond the terms of this now somewhat unproductive polemic. I propose to approach the problem in two stages. In the first place, I want to locate the UF within the framework of the present (November 1981) conjuncture in South Africa by tracing, briefly and somewhat schematically, certain developments bearing on the role of the Foundation during the nearly five years that have elapsed since it was initially set up in December 1976. Secondly, I shall argue that these developments have left the UF in a position in which it is poised between the reality in which it first took shape and the reality of the present, and I shall explore some of the dimensions of the critical strategic choice with which I believe it is now faced. Throughout, in order to keep the length of this article within acceptable limits and to avoid unnecessary references to matters that have received extensive coverage in the press, I will assume a degree of broad familiarity on the part of readers with the more general aims and activities of the UF

A place to live : The resolution of the African housing crisis in Johannesburg, 1944-1954

African Studies Seminar series. Paper presented 27 July 1981In March 1944, the African township of Orlando near Johannesburg witnessed the first of a wave of squatter movements which was to sweep across the Witwatersrand during the next three or four years. The movements were, for the most part, a desperate response to the apparent inability or reluctance of the authorities to tackle the massive backlog in housing provision which had developed, in the major industrial centres as African workers and their families flooded in to meet the expanding labour demand brought about by the wartime economic boom. Although South Africa had already experienced phases of rapid urbanization during earlier periods (notably the First World War), the magnitude of the problem which now confronted the state's housing apparatus was unprecedented and soon took on the dimensions of a full-blown crisis as decisive action to remedy the situation failed to materialize. By the beginning of 1955, however, not quite eleven years after the squatters had first thrust themselves into the official consciousness, an editorial in Bantu - the periodical published by the Department of Native Affairs to disseminate its 'viewpoint' amongst the African population - could claim: The solution of the Bantu housing problem has now reached a stage which we can call the end of the beginning. Improved houses are being completed every day. During the next ten years hundreds of thousands of Bantu will be properly housed for the first time (2). This paper is an attempt to move towards an explanation of how this 'solution' of the 'Bantu housing problem' was finally achieved and, more specifically, of how the foundations of what we now know as Soweto came to be laid. It focuses on the resolution of certain strategic issues linked to the provision of African housing and on the establishment of the particular legislative and institutional framework within which the concrete practices that were to generate the form of the 'modern' township were brought into play. In coming to terms with the mass of detailed and often confusing empirical material on which the paper is based, I have tried to avoid the danger of remaining trapped at the level of merely descriptive narrative by explicitly situating the evolution of African housing policy within the political and economic context on which, I would argue, it was always predicated. In this respect, I have found what I consider to be a useful point of entry into the labyrinth of 'facts' in Manuel Castells' conceptualisation of 'urban planning' as the theoretical field of state intervention in the 'urban', where the latter "refers not only to a spatial form, but expresses the social organization of the processes of reproduction"

Surface profile and acoustic emission as diagnostics of tool wear in face milling

This thesis examines the relationship between progressive wear of cutting inserts during a face milling operation and the acoustic emission and surface profile generated by that process. Milling experiments were performed on a range of workpiece materials using both eight point and single point inseý arrangements contained in two cutters of different geometries. Surface profile measurements were made using a stylus profilometer at intervals during the experiments. Correlations between the wear state as measured by the length of the flank wear land (Vb) and the spatial frequency content of the surface profiles were established. Investigations into the variation of fractal dimension of a milled surface with Vb demonstrated that no correlation was observable between these quantities. Acoustic emission (AE) measurements were made using a non-contacting fibre-optic interferometer which allowed the rms of the AE signal and its mean frequency to be determined. Correlations between these parameters and Vb were established for a range of workpiece materials and cutter geometries. It was shown that neither AE measurements nor surface profile measurements in isolation could predict tool wear state in all situations. The advantages of fusing data from surface profile and AE sources via an artificial neural network in tool wear monitoring were demonstrate

De concentv amisso qvaerendo: An investigation into the relative benefits of three different types of ambient music on the observed agitated behaviour and quality of life of dementia sufferers in residential aged care facilities

There is an increasing body of research evidence to support the use of music as a therapeutic modality in reducing the agitated behaviour frequently associated with late-stage dementia. Although much of this evidence suggests that music interventions are most effective when they are “individualized”, this type of intervention is often difficult to implement in large, busy, aged care facilities where residents may be located together in communal areas during the day. The challenge therefore is to try and identify a particular musical genre which, when played as “ambient” or “background” music, demonstrates a consistent capacity to reduce agitated behaviour in late-stage dementia across resident populations in multiple facilities. This study was designed to test the comparative utility of three different types of background music identified in the existing research literature as being of possible benefit in this context. These three types of music were: gentle classical music, familiar music and baroque music. Using a sample of 65 older people with late-stage dementia living in a total of eight residential aged care facilities, this quasi-experimental study used quantitative measures to assess a specific range of agitated behaviours over a one week intervention period. The specific agitated behaviours were documented using the Scale for the Observation of Agitation in Persons with Dementia (SOAP-D) scale (Hurley, Volicer, Camberg, Ashley, Woods, Odenheimer, Ooi, McIntyre, & Mahoney, 1999). In addition, the Quality of Life in Alzheimer’s Disease (QoL-AD) tool (Logsdon, 1999) was used to collect collateral information from family members or experienced care staff at each of the participating facilities about whether they perceived that the playing of music exerted any influence on the quality of life of participants. Participants were randomly assigned to one of five experimental subgroups of equal size. Participants in three of the five groups received exposure to audio recordings of music. Participants in one of the two remaining sub-groups were exposed to a non-musical intervention (audio recordings of storybooks) at the same time of day as the participants in the three music groups. Data relating to behaviour and perceived quality of life were recorded in the same manner for this group. The final group of participants acted as the control group for the study. Quantitative data were collected in the same manner for this group: however, they were exposed to no intervention. In addition, a series of structured interviews was undertaken with experienced care providers at each of the participating residential aged care facilities. The purpose of this procedure was to determine whether the experiences and subjective opinions of staff regarding the utility of music as an intervention to settle agitated behaviour in late-stage dementia and improve quality of life were consistent with the observational data recorded using the SOAP-D scale in conjunction with the proxy-rated QoL-AD scale. Results of the study indicated that overall levels of agitated behaviour were less within the three groups exposed to music compared with the nonmusic intervention group and the control. However, perceived quality of life was not measurably improved in any of the three music intervention groups. This study supports the continued use of music as a therapeutic intervention in the management of maladaptive behaviour associated with late-stage dementia, although the results do not support the preferential use of any of the three selected music forms