Expanded Parameters in the Self-Organized Critical Forest Fire Model

The forest fire model has frequently been used as a way to test the theory of Self-Organized Criticality, which is a model of complexity. The model analyzes commonalities in randomly generated forest fires using a computer simulation. In previous models, only the nearest neighbors to a tree on fire catch on fire, and it has been assumed that if further neighboring trees also catch on fire, then it will still exhibit self-organized criticality. Testing this assumption aids to the exploration of the applicability of self-organized criticality because the model is the most useful when it applies to a large range of systems, as closely related to nature as possible

Offending White Men: Racial Vilification, Misrecognition, and Epistemic Injustice

In this article I analyse two complaints of white vilification, which are increasingly occurring in Australia. I argue that, though the complainants (and white people generally) are not harmed by such racialized speech, the complainants in fact harm Australians of colour through these utterances. These complaints can both cause and constitute at least two forms of epistemic injustice (willful hermeneutical ignorance and comparative credibility excess). Further, I argue that the complaints are grounded in a dual misrecognition: the complainants misrecognize themselves in their own privileged racial specificity, and they misrecognize others in their own marginal racial specificity. Such misrecognition preserves the cultural imperialism of Australia’s dominant social imaginary—a means of oppression that perpetuates epistemic insensitivity.Bringing this dual misrecognition to light best captures the indignity that is suffered by the victims of the aforementioned epistemic injustices. I argue that it is only when we truly recognize difference in its own terms, shifting the dominant social imaginary, that “mainstream Australians”can do their part in bringing about a just society

Precision Weak Gravitational Lensing Using Velocity Fields: Fisher Matrix Analysis

Weak gravitational lensing measurements based on photometry are limited by shape noise, the variance in the unknown unlensed orientations of the source galaxies. If the source is a disk galaxy with a well-ordered velocity field, however, velocity field data can support simultaneous inference of the shear, inclination, and position angle, virtually eliminating shape noise. We use the Fisher Information Matrix formalism to forecast the precision of this method in the idealized case of a perfectly ordered velocity field defined on an infinitesimally thin disk. For nearly face-on targets one shear component, $\gamma_\times$, can be constrained to $0.003\frac{90}{I_0}\frac{25}{n_{\rm pix}}$ where $I_0$ is the S/N of the central intensity pixel and $n_{\rm pix}$ is the number of pixels across a diameter enclosing 80\% of the light. This precision degrades with inclination angle, by a factor of three by $i{=}50^\circ$. Uncertainty on the other shear component, $\gamma_+$, is about 1.5 (7) times larger than the $\gamma_\times$ uncertainty for targets at $i=10^\circ$ ($50^\circ$). For arbitrary galaxy position angle on the sky, these forecasts apply not to $\gamma_+$ and $\gamma_\times$ as defined on the sky, but to two eigenvectors in $(\gamma_+, \gamma_\times,\mu)$ space where $\mu$ is the magnification. We also forecast the potential of less expensive partial observations of the velocity field such as slit spectroscopy. We conclude by outlining some ways in which real galaxies depart from our idealized model and thus create random or systematic uncertainties not captured here. In particular, our forecast $\gamma_\times$ precision is currently limited only by the data quality rather than scatter in galaxy properties because the relevant type of scatter has yet to be measured.Comment: Accepted to ApJ, 17 pages, 14 figures. Diff from v1: added Sec 3.1 on degeneracies and Appendix with simulations confirming Fisher result

Work minimization accounts for footfall phasing in slow quadrupedal gaits

Quadrupeds, like most bipeds, tend to walk with an even left/right footfall timing. However, the phasing between hind and forelimbs shows considerable variation. Here, we account for this variation by modeling and explaining the influence of hind-fore limb phasing on mechanical work requirements. These mechanics account for the different strategies used by: (1) slow animals (a group including crocodile, tortoise, hippopotamus and some babies); (2) normal medium to large mammals; and (3) (with an appropriate minus sign) sloths undertaking suspended locomotion across a range of speeds. While the unusual hind-fore phasing of primates does not match global work minimizing predictions, it does approach an only slightly more costly local minimum. Phases predicted to be particularly costly have not been reported in nature

Sediment transport and erosion in the Fourchon area of Lafourche parish

NASA aerial photography in the form of color infrared and color positive transparencies is used as an aid in evaluating the rate and effect of erosion and sediment transport in Bay Champagne Louisiana

Moving people to deliver services : how can the WTO help?

The previous General Agreement on Trade in Services (GATS) negotiations produced little liberalization of the movement of individual service providers (mode 4), and the potentially large global gains from suchmovement remain unrealized. In the current negotiations, as part of the Doha Development Agenda, developing countries are seeking greater openness in their area of comparative advantage: the movement of providers unrelated to commercial presence abroad. At the same time, many multinational firms would like easier intra-corporate movement of their personnel. We describe how this coincidence of interest could be harnessed to deliver greater openness at least for skilled service providers.Environmental Economics&Policies,Health Monitoring&Evaluation,Decentralization,Public Health Promotion,Banks&Banking Reform,Trade and Services,Environmental Economics&Policies,Health Monitoring&Evaluation,Governance Indicators,Banks&Banking Reform

SO₂ emissions from basaltic eruptions, and the excess sulfur issue

Volcanic SO2 can affect the Earth's environment. Where no direct measurements of SO2 in the atmosphere are available, a petrologic method of assessing sulfur release from the magma must be used. However, in studies of arc-derived eruptions, satellite-based measurements of SO2 emissions using Total Ozone Mapping Spectrometer (TOMS) data are orders of magnitude greater than those calculated petrologically, implying that a separate S-rich gas phase in the magma chamber may be responsible for the excess sulfur. We test whether this applies in other settings. For Icelandic and Hawaiian basalts we find that petrologic SO2 values are comparable to measurements of SO2 by TOMS. Thus, for non-arc basalts, the petrologic method gives reliable estimates of SO2 released. The implied absence of excess sulfur in non-arc basaltic magmas is a reflection of source magma conditions, notably lower fO2 and volatile contents than arc magmas, inhibiting the exsolution of a S-rich gas prior to eruption