3,830 research outputs found
Participatory Planning and the Global South: A Case Study of Local Planning and Development in Vrygrond
Includes bibliographical references.Urbanisation is occurring most rapidly in the global South, where cities are characterised by increasing levels of poverty, socio-spatial inequality, and informality. Mainstream planning theories have tended to originate from the North, responding to a context that differs greatly from that of cities of the South where theories have been uncritically adopted and imposed. State planning systems in developing countries often reflect traditional technocratic approaches and have become increasingly disengaged from rapidly changing urban conditions. In a context in which neoliberalism is becoming increasingly hegemonic, such planning systems may serve the interests of capital over the needs of the poor. There has therefore been a call to focus on developing descriptive and explanatory theories through case research from which new and more contextually appropriate approaches to planning might emerge. I offer the case of Vrygrond as a contribution to this ongoing endeavour to ‘theorize from the South’, regrounding planning theory and practice in the realities and complexities of global South contexts. The case study explores the nature of development in the densely populated, low-income settlement in Cape Town, from 1997 to 2014. The main research question asks how services, public facilities and amenities have been secured in Vrygrond, and how planning theory and practice might learn from this experience. The dissertation therefore draws on semi-structured interviews to understand the interaction between development processes adopted by key actors and contextual factors which include racial and ethnic diversity, power struggles, oppositional forms of citizenship, mistrust, and pervasive crime. The findings are then interpreted through the application of three contrasting theoretical frameworks of technocratic planning, communicative and collaborative planning, and co-production. I argue that the assumptions underlying technocratic and communicative planning are problematic in the context of Vrygrond, and that co-production might be better placed to respond to a lack of access to public facilities as well as a broader sense of disempowerment and marginalization. Recommendations include institutional rearrangements that might foster a social context that would be more receptive to co-production. I call attention to the nature of citizenship in postapartheid communities, to social difference and power relations, and to the impact of crime and gangsterism on local governance, as important considerations for participatory planning approaches such as co-production
Semileptonic decays from full lattice QCD
We present first lattice QCD results for semileptonic form factors for the
decays and over the full
range, using both improved non-relativistic QCD (NRQCD) and fully relativistic
(HISQ) formalisms. These can be viewed as prototype calculations for
pseudoscalar to pseudoscalar and pseudoscalar to vector decays involving a transition. In particular we can use information from the relativistic
computations to fix the NRQCD current normalisations, which can then be used in
improved computations of decays such as and .Comment: 3 pages, 3 figures. Poster presented at the 16th International
Conference on B-Physics at Frontier Machines, 2-6 May 2016, Marseille, Franc
An investigation into a wavelet accelerated gauge fixing algorithm
We introduce an acceleration algorithm for coulomb gauge fixing, using the
compactly supported wavelets introduced by Daubechies. The algorithm is similar
to Fourier acceleration. Our provisional numerical results for on
lattices show that the acceleration based on the DAUB6 transform can
reduce the number of iterations by a factor up to 3 over the unaccelerated
algorithm. The reduction in iterations for Fourier acceleration is
approximately a factor of 7.Comment: Resubmitted as a uuencode-compressed-tar postscript file. A
Daubechies wavelet transform will transform a vector of length in
operations, and not in O(N log N) operations as we incorrectly stated in the
first version of this pape
Observations of the Structure and Dynamics of the Inner M87 Jet
M87 is the best source in which to study a jet at high resolution in
gravitational units because it has a very high mass black hole and is nearby.
The angular size of the black hole is second only to Sgr A*, which does not
have a strong jet. The jet structure is edge brightened with a wide opening
angle base and a weak counterjet. We have roughly annual observations for 17
years plus intensive monitoring at three week intervals for a year and five day
intervals for 2.5 months made with the Very Long Baseline Array (VLBA) at 43
GHz. The inner jet shows very complex dynamics, with apparent motions both
along and across the jet. Speeds from zero to over 2c are seen, with
acceleration observed over the first 3 milli-arcseconds. The counterjet
decreases in brightness much more rapidly than the main jet, as is expected
from relativistic beaming in an accelerating jet oriented near the
line-of-sight. Details of the structure and dynamics are discussed. The roughly
annual observations show side-to-side motion of the whole jet with a
characteristic time scale of about 9 years.Comment: 11 pages, 7 figures. Published in a special issue of Galaxies which
is the proceedings of "Blazars through Sharp Multi-Wavelength Eyes" edited by
J. L. Gomez, A. P. Marscher, and S. G. Jorsta
Precision tests of the J/psi from full lattice QCD: mass, leptonic width and radiative decay rate to eta_c
We show results from calculations in full lattice QCD of the mass, leptonic width and radiative decay rate to eta_c of the J/psi meson. These provide few % tests of QCD. Another (1.5%) test comes from comparison of time-moments of the vector charmonium correlator with results derived from the experimental values of R(e+e- to hadrons) in the charm region
Primary Sequence and Developmental Expression Pattern of mRNAs and Protein for an α1Subunit of the Sodium Pump Cloned from the Neural Plate ofXenopus laevis
AbstractExpression of a catalytic α subunit of the sodium pump was followed in earlyXenopusembryos for correlation with physiological experiments showing that the sodium pump controls cavity expansion and the differentiation of neurones from the neural plate. Two cDNAs (one full length, one partial) for α1subunit isoforms were cloned from a neural plate stageXenopuslibrary and sequenced. Other isoforms were not detected. Temporal and spatial expression patterns for α1subunit transcripts and protein revealed extensive developmental regulation. At all stages, cells involved in cavity generation (outer ectoderm and cells lining the archenteron) expressed α1transcripts with protein confined to the lateral and basal membranes. Before gastrulation, transcript levels were low and predominantly in animal cells. During gastrulation, α1mRNAs rose significantly. Transcripts and protein were down-regulated in future outer neural plate cells as the mesoderm invaginated. Protein appeared at the blastopore on apical surfaces of lip cells and apposing surfaces of invaginating cells, suggesting that the Na pump opposes entry of fluid. In early neurulae, α1mRNAs rose sharply. Transcript expression remained low in outer neural plate cells and increased in the endoderm, and protein appeared in the notochord. In midneurulae, transcripts returned in outer neural plate cells. Protein expression appeared on basal surfaces of deep neural plate cells and the floor plate, matching physiological observations. After neural tube closure, transcripts were detected in all dorsal structures. Protein was retained in the notochord and floor plate, was eliminated from the outer layer of the neural tube, and appeared on ependymal cells. The results are discussed in relation to previous physiological observations
The developing juvenile talus:Radiographic identification of distinct ontogenetic phases and structural trajectories
Trabecular bone architecture in the developing skeleton is a widely researched area of bone biomechanics; however, despite its significance in weight-bearing locomotion, the developing talus has received limited examination. This study investigates the talus with the purpose of identifying ontogenetic phases and developmental patterns that contribute to the growing understanding of the developing juvenile skeleton. Colour gradient mapping and radiographic absorptiometry were utilised to investigate 62 human tali from 38 individuals, ranging in age-at-death from 28 weeks intrauterine to 20 years of age. The perinatal talus exhibited a rudimentary pattern comparable to the structural organisation observed within the late adolescent talus. This early internal organisation is hypothesised to be related to the vascular pattern of the talus. After 2 years of age, the talus demonstrated refinement, where radiographic trajectories progressively developed into patterns consistent with adult trabecular organisation, which are linked to the forces associated with the bipedal gait, suggesting a strong influence of biomechanical forces on the development of the talus.</p
Heavy-light current-current correlators
The current-current correlator method has been used successfully to obtain
very accurate results for quark masses and the coupling alpha_s. The
calculations were done using Highly Improved Staggered Quarks (HISQ) and
heavy-heavy meson correlators. We now extend this work to the significantly
more challenging heavy-light case, reporting the first results here. The aim is
to determine nonperturbative Z factors for NRQCD heavy-light currents, but
first we test the method in the HISQ case where Z=1.Comment: 7 pages. Presented at the XXVIII International Symposium on Lattice
Field Theory (Lattice 2010), June 14-19 2010, Villasimius, Ital
Towards high-resolution astronomical imaging
This paper is a report from a recent meeting on "the Future of
high-resolution imaging in the visible and infrared", reviewing the
astronomical drivers for development and the technological advances that might
boost performance. Each of the authors listed contributed a section themselves.Comment: 6 pages, 7 figures, 11 contributors, Accepted for publication in
Astronomy & Geophysics of the RAS, June 2019 issu
Regression discontinuity designs in health: a systematic review
Background:
Regression discontinuity designs are non-randomized study designs that permit strong causal inference with relatively weak assumptions. Interest in these designs is growing but there is limited knowledge of the extent of their application in health. We aimed to conduct a comprehensive systematic review of the use of regression discontinuity designs in health research.
Methods:
We included studies that used regression discontinuity designs to investigate the physical or mental health outcomes of any interventions or exposures in any populations. We searched 32 health, social science, and grey literature databases (1 January 1960-1 January 2019). We critically appraised studies using eight criteria adapted from the What Works Clearinghouse Standards for regression discontinuity designs. We conducted a narrative synthesis, analyzing the forcing variables and threshold rules used in each study.
Results:
The literature search retrieved 7658 records, producing 325 studies that met the inclusion criteria. A broad range of health topics were represented. The forcing variables used to implement the design were age; socioeconomic measures; date or time of exposure or implementation; environmental measures such as air quality; geographic location; and clinical measures that act as a threshold for treatment. Twelve percent of the studies fully met the eight quality appraisal criteria. Fifteen percent of studies reported a pre-specified primary outcome or study protocol.
Conclusions:
This systematic review demonstrates that regression discontinuity designs have been widely applied in health research and could be used more widely still. Shortcomings in study quality and reporting suggest that the potential benefits of this method have not yet been fully realized
- …