475 research outputs found
Responsibility, refusal, and return: Thoughts on an ethics of inclination
In this article written in honour of Desmond Tutu, I raise inclination as put forward by Cavarero, together with disorientation/reorientation, as per Ahmed and Honig, to think differently about law, rule of law, and legal culture. Drawing on Ndebele, Klare and Van der Walt, I consider inclination as being also about abandoning those vertical and upright certitudes acquired by habit and culture. An ethics and ontology of inclination could, by way of refusal, disclose alternative understandings of law and rule of law. It could challenge those assumptions of certainty and truth that are so central to formalist and black-letter takes on law and current legal culture. I raise inclination also in the vein of a minor jurisprudence and joining McVeigh and Barr’s writing on minor jurisprudence to engage with the question of how to take responsibility for a lawful life, how to respond to the legacy of the past
Vascular disease in HIV/AIDS patients
Objectives. An ongoing prospective clinical survey to determine the spectrum of vascular disease in HIV/AIDS patients and the risk factors affecting clinical outcome in order to formulate a management protocol for future use.
Methods. Comprehensive screening for risk factors for vascular disease as well as HIV/AIDS-related conditions. Disease pattern and presentation are noted and patients treated accordingly. Vascular emergencies are managed regardless of HIV status because this information is usually not available at the time of presentation. Elective management is based on immune status and risk stratification.
Results. 42 patients tested positive for HIV. The majority of patients presented with occlusive disease (57%), followed by anearysms (21%) and vascular trauma (19%). A variety of vascular surgical procedures were performed on 36 patients. There was no surgical mortality and 10 patients developed complications, including 2 amputations and 7 cases of minor wound sepsis. The 3 patients who received preoperative antiretroviral therapy showed a marked reduction in viral count and a significant improvement in CD4 T-cell count.
Conclusion. Surgery can be safe and effective in HIV-positive patients provided the necessary precautions are taken to reduce surgical morbidity.
(South African Medical Journal: 2002 92(12): 974-977
The use of an automated flight test management system in the development of a rapid-prototyping flight research facility
An automated flight test management system (ATMS) and its use to develop a rapid-prototyping flight research facility for artificial intelligence (AI) based flight systems concepts are described. The ATMS provides a flight test engineer with a set of tools that assist in flight planning and simulation. This system will be capable of controlling an aircraft during the flight test by performing closed-loop guidance functions, range management, and maneuver-quality monitoring. The rapid-prototyping flight research facility is being developed at the Dryden Flight Research Facility of the NASA Ames Research Center (Ames-Dryden) to provide early flight assessment of emerging AI technology. The facility is being developed as one element of the aircraft automation program which focuses on the qualification and validation of embedded real-time AI-based systems
Afriforum v Malema: The limits of law and complexity
The Afriforum v Malema 2011 6 SA 240 (EqC) case drew considerable attention in the media and in the public discourse. The purpose of this note is to reflect upon the judgment from a theoretical vantage point. More specifically, by reading the judgment through an autopoietic systems theory lens, some points of criticism on the judgment in particular and the law in general become apparent. It is contended that the judgment illustrates how law necessarily excludes the factual complexity of a case, first by deciding which are the only facts legally relevant, and then second by reducing their meaning to a simple judgment of legal or illegal. Since law recognises only legal communication, this function means that the communication and identity are removed from legal subjects and given legal meanings. An attempt is made to open law to considerations external to what it traditionally considers to be relevant to its operation. The problem that law excludes facts it deems irrelevant is addressed through the introduction of a third value whereby to measure the legal and illegal, namely justice. Through asking if its judgments of legal or illegal are just, law becomes capable of reflexive self-observation. In this manner the very complex historical and narrative trappings of the case at hand do not need to be excluded as they are in the judgment. Rather than absolute, binary judgments, a slower, reflective engagement that makes modest claims is supported.
Wide-field global VLBI and MERLIN combined monitoring of supernova remnants in M82
From a combination of MERLIN (Multi-Element Radio-Linked Interferometer
Network) and global VLBI (Very Long Baseline Interferometry) observations of
the starburst galaxy M82, images of 36 discrete sources at resolutions ranging
from ~3 to ~80 mas at 1.7 GHz are presented. Of these 36 sources, 32 are
identified as supernova remnants, 2 are HII regions, and 3 remain unclassified.
Sizes, flux densities and radio brightnesses are given for all of the detected
sources. Additionally, global VLBI only data from this project are used to
image four of the most compact radio sources. These data provide a fifth epoch
of VLBI observations of these sources, covering a 19-yr time-line. In
particular, the continued expansion of one of the youngest supernova remnants,
43.31+59.3 is discussed. The deceleration parameter is a power-law index used
to represent the time evolution of the size of a supernova remnant. For the
source 43.31+59.3, a lower limit to the deceleration parameter is calculated to
be 0.53+/-0.06, based on a lower limit of the age of this source.Comment: 31 pages, 12 figures, 7 table
A new radiative cooling curve based on an up to date plasma emission code
This work presents a new plasma cooling curve that is calculated using the
SPEX package. We compare our cooling rates to those in previous works, and
implement the new cooling function in the grid-adaptive framework `AMRVAC'.
Contributions to the cooling rate by the individual elements are given, to
allow for the creation of cooling curves tailored to specific abundance
requirements. In some situations, it is important to be able to include
radiative losses in the hydrodynamics. The enhanced compression ratio can
trigger instabilities (such as the Vishniac thin-shell instability) that would
otherwise be absent. For gas with temperatures below 10,000 K, the cooling time
becomes very long and does not affect the gas on the timescales that are
generally of interest for hydrodynamical simulations of circumstellar plasmas.
However, above this temperature, a significant fraction of the elements is
ionised, and the cooling rate increases by a factor 1000 relative to lower
temperature plasmas.Comment: 11 pages, 6 figures. Typos fixed to match version on A&A
'forthcoming' website. Tables in text format online available at
http://www.phys.uu.nl/~schure/coolin
First Stars. II. Evolution with mass loss
The first stars are assumed to be predominantly massive. Although, due to the
low initial abundances of heavy elements the line-driven stellar winds are
supposed to be inefficient in the first stars, these stars may loose a
significant amount of their initial mass by other mechanisms.
In this work, we study the evolution with a prescribed mass loss rate of very
massive, galactic and pregalactic, Population III stars, with initial
metallicities and , respectively, and initial masses
100, 120, 150, 200, and 250 during the hydrogen and helium burning
phases.
The evolution of these stars depends on their initial mass, metallicity and
the mass loss rate. Low metallicity stars are hotter, compact and luminous, and
they are shifted to the blue upper part in the Hertzprung-Russell diagram. With
mass loss these stars provide an efficient mixing of nucleosynthetic products,
and depending on the He-core mass their final fate could be either
pair-instability supernovae or energetic hypernovae. These stars contributed to
the reionization of the universe and its enrichment with heavy elements, which
influences the subsequent star formation properties.Comment: Accepted for publication in Astrophysics & Space Science. 15 pages,
18 figure
Comprehensive multi-wavelength modelling of the afterglow of GRB050525A
The Swift era has posed a challenge to the standard blast-wave model of Gamma
Ray Burst (GRB) afterglows. The key observational features expected within the
model are rarely observed, such as the achromatic steepening (`jet-break') of
the light curves. The observed afterglow light curves showcase additional
complex features requiring modifications within the standard model. Here we
present optical/NIR observations, millimeter upper limits and comprehensive
broadband modelling of the afterglow of the bright GRB 0505025A, detected by
Swift. This afterglow cannot be explained by the simplistic form of the
standard blast-wave model. We attempt modelling the multi-wavelength light
curves using (i) a forward-reverse shock model, (ii) a two-component outflow
model and (iii) blast-wave model with a wind termination shock. The
forward-reverse shock model cannot explain the evolution of the afterglow. The
two component model is able to explain the average behaviour of the afterglow
very well but cannot reproduce the fluctuations in the early X-ray light curve.
The wind termination shock model reproduces the early light curves well but
deviates from the global behaviour of the late-time afterglow.Comment: 20 pages, 6 figures, accepted for publication in MNRA
Structure determination of a bio-inspired self-assembled light-harvesting antenna by solid-state NMR and molecular modeling
Solid state NMR/Biophysical Organic Chemistr
Dynamics of Relativistic Interacting Gases : from a Kinetic to a Fluid Description
Starting from a microscopic approach, we develop a covariant formalism to
describe a set of interacting gases. For that purpose, we model the collision
term entering the Boltzmann equation for a class of interactions and then
integrate this equation to obtain an effective macroscopic description. This
formalism will be useful to study the cosmic microwave background
non-perturbatively in inhomogeneous cosmologies. It should also be useful for
the study of the dynamics of the early universe and can be applied, if one
considers fluids of galaxies, to the study of structure formation.Comment: Latex file, 28 pages, accepted for publication in Class. Quant. Gra
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