Colony-specific foraging areas of lactating New Zealand fur seals

Copyright © 2008 Inter-Research.During 2005 and 2006, 21 lactating New Zealand fur seals Arctocephalus forsteri were tracked from 4 breeding colonies in southern Australia. The distance between colonies ranged between 46 and 207 km. In total, 101 foraging trips were recorded (2 to 19 trips ind.–1). Seals initiated foraging trips on a colony-specific bearing (Cape Gantheaume 141 ± 34°, Cape du Couedic 188 ± 12°, North Neptune Island 204 ± 12° and Liguanea Island 235 ± 19°). During autumn, seals from Cape du Couedic, North Neptune Island and Liguanea Island predominantly targeted distant oceanic waters associated with the subtropical front (STF), while seals from Cape Gantheaume targeted shelf waters associated with a seasonal coastal upwelling, the Bonney upwelling. The distance of each colony from the STF (based on the preferred colony bearing) or the Bonney upwelling in the case of Cape Gantheaume was correlated with the maximum straight-line distances travelled (Cape Gantheaume 119 ± 57 km, Cape du Couedic 433 ± 99 km, North Neptune Island 564 ± 97 km and Liguanea Island 792 ± 82 km). The organisation of colony-specific foraging grounds appears to be influenced by the proximity of colonies to predictable local upwelling features, as well as distant oceanic frontal zones. Knowledge of whether New Zealand fur seals utilise colony-specific foraging grounds may be important in predicting and identifying critical habitats and understanding whether management requirements are likely to vary between different colonies.Alastair Martin Mitri Baylis, Brad Page, Simon David Goldsworth

Spin Gauge Theory of Gravity in Clifford Space: A Realization of Kaluza-Klein Theory in 4-Dimensional Spacetime

A theory in which 4-dimensional spacetime is generalized to a larger space, namely a 16-dimensional Clifford space (C-space) is investigated. Curved Clifford space can provide a realization of Kaluza-Klein theory. A covariant Dirac equation in curved C-space is explored. The generalized Dirac field is assumed to be a polyvector-valued object (a Clifford number) which can be written as a superposition of four independent spinors, each spanning a different left ideal of Clifford algebra. The general transformations of a polyvector can act from the left and/or from the right, and form a large gauge group which may contain the group U(1)xSU(2)xSU(3) of the standard model. The generalized spin connection in C-space has the properties of Yang-Mills gauge fields. It contains the ordinary spin connection related to gravity (with torsion), and extra parts describing additional interactions, including those described by the antisymmetric Kalb-Ramond fields.Comment: 57 pages; References added, section 2 rewritten and expande

Modelling the effects of past and future climate on the risk of bluetongue emergence in Europe

Vector-borne diseases are among those most sensitive to climate because the ecology of vectors and the development rate of pathogens within them are highly dependent on environmental conditions. Bluetongue (BT), a recently emerged arboviral disease of ruminants in Europe, is often cited as an illustration of climate's impact on disease emergence, although no study has yet tested this association. Here, we develop a framework to quantitatively evaluate the effects of climate on BT's emergence in Europe by integrating high-resolution climate observations and model simulations within a mechanistic model of BT transmission risk. We demonstrate that a climate-driven model explains, in both space and time, many aspects of BT's recent emergence and spread, including the 2006 BT outbreak in northwest Europe which occurred in the year of highest projected risk since at least 1960. Furthermore, the model provides mechanistic insight into BT's emergence, suggesting that the drivers of emergence across Europe differ between the South and the North. Driven by simulated future climate from an ensemble of 11 regional climate models, the model projects increase in the future risk of BT emergence across most of Europe with uncertainty in rate but not in trend. The framework described here is adaptable and applicable to other diseases, where the link between climate and disease transmission risk can be quantified, permitting the evaluation of scale and uncertainty in climate change's impact on the future of such diseases

Higher spin quaternion waves in the Klein-Gordon theory

Electromagnetic interactions are discussed in the context of the Klein-Gordon fermion equation. The Mott scattering amplitude is derived in leading order perturbation theory and the result of the Dirac theory is reproduced except for an overall factor of sixteen. The discrepancy is not resolved as the study points into another direction. The vertex structures involved in the scattering calculations indicate the relevance of a modified Klein-Gordon equation, which takes into account the number of polarization states of the considered quantum field. In this equation the d'Alembertian is acting on quaternion-like plane waves, which can be generalized to representations of arbitrary spin. The method provides the same relation between mass and spin that has been found previously by Majorana, Gelfand, and Yaglom in infinite spin theories

de Broglie waves as the "Bridge of Becoming" between quantum theory and relativity

It is hypothesized that de Broglie's 'matter waves' provide a dynamical basis for Minkowski spacetime in an antisubstantivalist or relational account. The relativity of simultaneity is seen as an effect of the de Broglie oscillation together with a basic relativity postulate, while the dispersion relation from finite rest mass gives rise to the differentiation of spatial and temporal axes. Thus spacetime is seen as not fundamental, but rather as emergent from the quantum level. A result by Solov'ev which demonstrates that time is not an applicable concept at the quantum level is adduced in support of this claim. Finally, it is noted that de Broglie waves can be seen as the "bridge of becoming" discussed by Elitzur and Dolev (2005).Comment: Forthcoming in Foundations of Science; reference added to recent work of Dolc

Evaluation of surface analysis methods for characterization of trace metal surface contaminants found in silicon IC manufacturing

A major topic at recent silicon-based integrated circuit (IC) manufacturing symposia is the pursuit of decreased contamination levels. The aim is to remove contamination from both processes and materials. In conjunction with this effort, characterization methods are being pushed to lower and lower detection limits. In this paper, we evaluate surface analysis methods used to determine the concentration of inorganic contamination on unpatterned Si wafers. We compare sampling depths, detection limits, and applicability of each method for use in support of Si IC manufacturing. This comparison is further limited to Fe and Cu which are transition metal contaminants associated with manufacturing yield loss. The surface analysis methods included in this evaluation are: Total Reflection X-Ray Fluorescence (TXRF or TRXRF); Secondary Ion Mass Spectrometry (SIMS); two post-ionization'' methods Surface Analysis by Laser Ionization (SALI) and Sputter Initiated Resonant Ionization Spectroscopy (SIRIS); Heavy Ion Backscattering Spectroscopy (HIBS); and Vapor Phase Phase Decomposition (VPD) based methods Atomic Absorption (VPD-AA) along with VPD-TXRF. Sets of 6 in. Si wafers with concentration levels between 10{sup 9} atoms/cm{sup 2} and 10{sup 12} atoms/cm{sup 2} Fe and Cu were characterized by TXRF, SIMS, SIRIS, and HIBS. This data allows estimation of detection limits (DLs) and relative method accuracy. In Section 1 we describe each surface analysis method and the circumstance under which it would be used to support Si IC manufacturing. The equipment used for this comparison and the 150 mm Si wafer set are described in Section 2. Results from each method are contrasted in Section 3. Finally, a conclusion is presented in Section 4