12,401 research outputs found
Critical discourse analysis, description, explanation, causes: Foucault's inspiration versus Weber's perspiration
The FOUCAULTian governmentality approach, in relying on a teleology - the ultimate purpose of human endeavour is the quest for ever-growing human reason, a reason that is the universal basis of moral judgements, especially moral judgements about political and legal actions - leads not to description, explanation and the possible identification of causes, but to critique, to the inappropriate conflation of, on the one hand, description, explanation and the identification of causes with, on the other, political criticisms sourced in the teleology. Drawing on some of WEBER's methodological insights, an argument is developed that critical discourse analysis, in taking on the FOUCAULTian approach, gives up the best traditions of description, explanation and the identification of causes in favour of the expression, in many different forms, of the teleology
Like vs. Like: Strategy and Improvements in Supernova Cosmology Systematics
Control of systematic uncertainties in the use of Type Ia supernovae as
standardized distance indicators can be achieved through contrasting subsets of
observationally-characterized, like supernovae. Essentially, like supernovae at
different redshifts reveal the cosmology, and differing supernovae at the same
redshift reveal systematics, including evolution not already corrected for by
the standardization. Here we examine the strategy for use of empirically
defined subsets to minimize the cosmological parameter risk, the quadratic sum
of the parameter uncertainty and systematic bias. We investigate the optimal
recognition of subsets within the sample and discuss some issues of
observational requirements on accurately measuring subset properties.
Neglecting like vs. like comparison (i.e. creating only a single Hubble
diagram) can cause cosmological constraints on dark energy to be biased by
1\sigma or degraded by a factor 1.6 for a total drift of 0.02 mag. Recognition
of subsets at the 0.016 mag level (relative differences) erases bias and
reduces the degradation to 2%.Comment: 11 pages, 6 figure
Metal-rich T-dwarfs in the Hyades cluster
We present the results of a search for brown dwarfs (BDs) and very low mass
(VLM) stars in the 625 Myr-old, metal-rich ([Fe/H]=0.14) Hyades cluster. We
performed a deep (I=23, z=22.5) photometric survey over 16 deg around the
cluster center. We report the discovery of the first 2 BDs in the Hyades
cluster, with a spectral type T1 and T2, respectively. Their optical and
near-IR photometry, as well as their proper motion, are consistent with them
being cluster members. According to models, their mass is about 50 Jupiter
masses at an age of 625 Myr. We also report the discovery of 3 new very low
mass stellar members and confirm the membership of 15 others
Constraints on the sound speed of dark energy
We have studied constraints on the equation of state, , and speed of
sound, c_s, of the dark energy from a joint analysis of data from the cosmic
microwave background, large scale structure and type-Ia supernovae. We find
that current observations have no significant sensitivity to c_s. However,
there is a slight difference between models in which there are no dark energy
perturbations and models in which dark energy behaves as a fluid. Assuming that
there are no dark energy perturbations shifts the allowed region for to
slightly higher values. At present models with and without dark energy
perturbations provide roughly equally good fits to observations, but the
difference is potentially important for future parameter estimations. Finally,
we have also performed error forecasts for future measurements of c_s.Comment: 9 pages, 6 figures, Revte
Is Evolutionary Computation evolving fast enough?
Evolutionary Computation (EC) has been an active research area for over 60 years, yet its commercial/home uptake has not been as prolific as we might have expected. By way of comparison, technologies such as 3D printing, which was introduced about 35 years ago, has seen much wider uptake, to the extent that it is now available to home users and is routinely used in manufacturing. Other technologies, such as immersive reality and artificial intelligence have also seen commercial uptake and acceptance by the general public. In this paper we provide a brief history of EC, recognizing the significant contributions that have been made by its pioneers. We focus on two methodologies (Genetic Programming and Hyper-heuristics), which have been proposed as being suitable for automated software development, and question why they are not used more widely by those outside of the academic community. We suggest that different research strands need to be brought together into one framework before wider uptake is possible. We hope that this position paper will serve as a catalyst for automated software development that is used on a daily basis by both companies and home users
The role of endotoxin, the TNF family of cytokines and intracellular pH in perinatal hypoxic-ischemic brain injury
To explore the effect of endotoxin as a sensitising agent prior to neonatal hypoxiaischemia
differing doses of endotoxin (E. coli lipopolysaccharide, LPS) were given to
neonatal mice prior to hypoxia-ischemia, with sensitising effects noted at dosages of
0.3mg/kg of LPS or higher. Varying the time interval between endotoxin administration
and hypoxia-ischemia demonstrated that LPS given between 4 and 12 hours before
hypoxia-ischemia had a sensitising effect on subsequent hypoxia ischemia. In contrast,
LPS given at the time of or 24 hours before hypoxia-ischemia did not. To help
understand the mechanism by which this sensitising effect occurs, a dose-response
study of LPS alone was undertaken. Here, a dose-dependent activation of microglia
was demonstrated throughout the brain, particularly in the thalamus and cortex, by 12
hours following endotoxin administration. There was also evidence of vascular
endothelial activation (ICAM1) as early as 4 hours after endotoxin administration. To
study the role of the TNF cluster of cytokines (TNF alpha, lymphotoxin alpha and
lymphotoxin beta), animals with a deletion of the entire TNF cluster were examined.
Deletion of the TNF cluster was shown to abolish both endotoxin-mediated
sensitisation of the developing brain to subsequent hypoxia, and to prevent
upregulation of macrophage and vascular endothelium by endotoxin alone.
This study also examined the effects of hypoxia-ischemia on intracellular pH.
Increasing duration of hypoxia-ischemia resulted in a progressive intracellular acidosis
within the brain, initially ipsilateral to the carotid ligation, but becoming bilateral with
prolonged hypoxia. In the reoxygenation phase, there was a rebound intracellular
alkalosis at 6 hours of reoxygenation across the whole forebrain. Previous studies
have suggested that this alkalosis is mediated by a Na+/H+ exchanger. Blockade of
this transporter with N-methyl isobutyl amiloride prior to hypoxia-ischemia was shown
to confer neuroprotection in the developing brain
INSURING AGAINST LOSSES FROM TRANSGENIC CONTAMINATION
Concerns about contamination of the food supply and the financial losses that would result have limited the promise of certain genetically engineered plants. This article addresses the situation by constructing an insurance pricing model to protect against those losses. The model first estimates the physical dispersal of corn pollen subject to a number of parameters. This physical distribution is then used to calculate the premium for fair valued insurance that would be necessary to destroy contaminated fields. The flexible framework can be readily adapted to other crops, management practices, and regions.contemporaneous fertility, insurance, Lagrangian stochastic model, pharmaceutical-corn, pollen dispersal, Crop Production/Industries, Risk and Uncertainty,
Initial radio-frequency gas heating experiments to simulate the thermal environment in a nuclear light bulb reactor
Initial radio frequency gas heating experiments to simulate thermal environment in nuclear light bulb reacto
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