Health Assessment of Weddell Seals, \u3ci\u3eLeptonychotes weddellii\u3c/i\u3e, in McMurdo Sound, Antarctica

The demography of Weddell seals in eastern McMurdo Sound, Antarctica, has been well studied during the past three decades (e.g. Stirling 1971; Siniff et al. 1977; Testa and Siniff 1987; Hastings and Testa 1998; Gelatt et al. 2001). Detailed life-history data are available on thousands of seals tagged as pups in McMurdo Sound, making this population a rich resource for wildlife health studies because health parameters can be evaluated in the light of reproductive histories and genetic relationships of several generations of tagged seals. Recently, evidence of exposure to diseases generally associated with domestic animals and feral wildlife has been detected in Antarctic wildlife (Austin and Webster 1993; Olsen et al. 1996; Gardner et al. 1997; Retamal et al. 2000; Foster et al. 2002) and this has generated concern and debate regarding the risks of disease introduction to Antarctic wildlife. Antibodies to viruses that have caused large die-offs in phocids in other areas of the world have been detected in Weddell seals (Bengtson et al. 1991), and there is a historical report of a mass die-off of crabeater seals that may have had a viral etiology (Laws and Taylor 1957)

Aerial Surveys for Cetaceans in the Former Akutan, Alaska, Whaling Grounds

Randomized aerial surveys were flown between 26 July and 26 August 1984 to search for cetaceans in two areas of southwestern Alaska: one on both Bering Sea and Pacific Ocean sides of the Aleutian Islands near the defunct Akutan shore-whaling station, which operated from 1912 through 1938, the other overlapping continental slope and shallow continental shelf waters between the Aleutians and the Pribilof Islands. ... Searches covered about 3940 nautical miles (nm), including some 2403 nm of random transects. Sightings were made of gray whales (10 sightings, 14 individuals), fin whales (3, 11), minke whales (1, 1), unidentified beaked whales (1, 6), Dall's porpoises (47, 131), killer whales (8, 26), and harbor porpoises (4, 7). A Fourier series model was used to estimate density of Dall's porpoises as 115 individuals (CV=0.263) per 1000 sq nm on the whaling grounds and 16.6 individuals (CV=0.0) per sq nm in the Bering Sea north of the whaling grounds. These estimates are comparable to those previously reported for the same general areas (97.2 animals per 1000 sq nm, SD=49.5). There were too few sightings of other cetaceans to permit calculation of meaningful density estimates. At least four species of great whales (blue, fin, humpback and sperm) were sufficiently abundant during the first four decades of this century to support significant whaling activities within about 100 sq nm of Akutan (more than 5300 whales were caught during 23 years of whaling, 1912-39). Although previous studies of the fisheries showed a downward trend in catch per unit of effort and an increase in distance traveled to take whales, whales were still being taken at relatively high rates (0.28-0.51 whales per gross catcher day) at the end of the fishery in 1939. Populations of fin, humpback, blue and sperm whales were probably significantly reduced by shore and pelagic whaling conducted widely in the North Pacific since 1939. ...Key words: aerial surveys, cetaceans, Bering Sea, North Pacific Ocean, historical whaling Des relevés aériens ont été effectués au hasard entre le 26 juillet et le 26 août 1984, afin de déterminer la présence de cétacés dans deux régions du Sud-Ouest de l'Alaska : l'une située des deux côtés des îles Aléoutiennes (du côté de la mer de Béring et du côté de l'océan Pacifique), près de ce qui fut jadis le port baleinier d'Akukan qui resta en opération de 1912 à 1939; l'autre couvrant à la fois les eaux du talus continental et celles, peu profondes, de la plate-forme continentale, entre les îles Aléoutiennes et les îles Pribilof. Les relevés furent effectuées à des altitudes comprises entre 150 et 245 m, d'un appareil d'observation Partenavia P68, muni d'un nez de plexiglas, permettant de voir dans l'axe de déplacement. Les recherches ont été effectuées sur environ 3940 milles nautiques (mn), y compris 2403 mn de recoupements au hasard. One a relevé la présence de baleines grises (10 relevés, 14 individus), de rorquals communs (3, 11), de petits rorquals (1, 1), de baleines à bec non identifiées (1, 6), de marsouins de Dall (47, 131), d'épaulards (8, 26) et de marsouins communs. On a utilisé un modèle en séries de Fourier pour déterminer approximativement la densité de marsouins de Dall à 115 individus (CV = 0.263) aux 1000 mn² dans les zones de pêche à la baleine, et à 16.6 individus (CV = 0.0) aux 1000 mn² dans la mer de Béring au nord des zones de pêche. Ces évaluations sont comparables à celles rapportées précédemment pour ces mêmes zones en général (97.2 animaux aux 1000 mn², DS = 49.5). Trop peu d'autres cétacés ont été aperçus pour justifier le calcul des densités approximatives. Durant les quarante premières années de ce siècle, il y avait au moins quatre espèces de grandes baleines (rorquals bleus, rorquals communs, rorquals à bosse et cachalots) en quantité suffisante pour alimenter une industrie baleinière dans un rayon d'environ 100 mn d'Akutan. (Plus de 5300 baleines furent pêchées durant les 23 années que dura la pêche à la baleine, de 1912 à 1939). Bien que des études précédentes sur la pêche aient montré une tendance à la baisse du nombre de prises par rapport au nombre d'unités d'effort et une augmentation de la distance à parcourir pour capturer les baleines, celles-ci étaient capturées à un taux relativement élevé (de 0.28 à 0.51 baleine par unité d'effort brute par jour) à la fin de la pêche en 1939. Les populations de rorquals communs, de rorquals à bosse, de rorquals bleus et de cachalots ont probablement été réduites de façon significative par le pêche côtière et la pêche pélagique, qui ont été pratiquées à grande échelle dans le Pacifique Nord depuis 1939. Le petit nombre de cétacés aperçus durant les présents relevés porte à croire que les populations dans les zones de pêche et dans leur vicinité, restent peu élevées en raison de ces activités. Mots clés : relevé aérien, cétacés, mer de Béring, Pacifique Nord, ancienne pêche à la balein

A review of data on abundance, trends in abundance, habitat use and diet of ice-breeding seals in the Southern Ocean

The development of models of marine ecosystems in the Southern Ocean is becoming increasingly important as a means of understanding and managing impacts such as exploitation and climate change. Collating data from disparate sources, and understanding biases or uncertainties inherent in those data, are important first steps for improving ecosystem models. This review focuses on seals that breed in ice habitats of the Southern Ocean (i.e. crabeater seal, Lobodon carcinophaga; Ross seal, Ommatophoca rossii; leopard seal, Hydrurga leptonyx; and Weddell seal, Leptonychotes weddellii). Data on populations (abundance and trends in abundance), distribution and habitat use (movement, key habitat and environmental features) and foraging (diet) are summarised, and potential biases and uncertainties inherent in those data are identified and discussed. Spatial and temporal gaps in knowledge of the populations, habitats and diet of each species are also identified

Solving the Hamilton-Jacobi Equation for General Relativity

We demonstrate a systematic method for solving the Hamilton-Jacobi equation for general relativity with the inclusion of matter fields. The generating functional is expanded in a series of spatial gradients. Each term is manifestly invariant under reparameterizations of the spatial coordinates (``gauge-invariant''). At each order we solve the Hamiltonian constraint using a conformal transformation of the 3-metric as well as a line integral in superspace. This gives a recursion relation for the generating functional which then may be solved to arbitrary order simply by functionally differentiating previous orders. At fourth order in spatial gradients, we demonstrate solutions for irrotational dust as well as for a scalar field. We explicitly evolve the 3-metric to the same order. This method can be used to derive the Zel'dovich approximation for general relativity.Comment: 13 pages, RevTeX, DAMTP-R93/2

Assembly of the Inner Perivitelline Layer, a Homo log of the Mammalian Zona Pellucida: An Immunohistochemical and Ultrastructural Study

The avian inner perivitelline layer (IPVL), a homologous structure to the mammalian zona pellucida, is deposited between the granulosa cells and the oocyte cell membrane during folliculogenesis. The glycoprotein meshwork of the IPVL forms a 3-dimensional matrix and possesses important functions in the fertilization process: it contributes to the binding of avian spermatozoa to the oocyte and induces acrosomal exocytosis. In contrast to the zona pellucida of mammals, the IPVL does not prevent the physiological polyspermy found in birds. Previous studies have shown that in the Japanese quail (Cotumix japonica) at least 5 glycoproteins are constituents of the IPVL (ZP1, ZP2, ZP3, ZP4, and ZPD). In this study, we investigated the spatiotennporal assembly pattern of the IPVL during folliculogenesis using immunohistochemical and ultrastructural methods. The obtained results clearly show that these glycoproteins are incorporated into the IPVL at distinct points during follicular development, supporting the hypothesis that ZP2 and ZP4 form a type of prematrix into which ZP1, ZP3, and ZPD are integrated at a later stage of development. Copyright (C) 2011 S. Karger AG, Base

D3/D7 Inflationary Model and M-theory

A proposal is made for a cosmological D3/D7 model with a constant magnetic flux along the D7 world-volume. It describes an N=2 gauge model with Fayet-Iliopoulos terms and the potential of the hybrid P-term inflation. The motion of the D3-brane towards D7 in a phase with spontaneously broken supersymmetry provides a period of slow-roll inflation in the de Sitter valley, the role of the inflaton being played by the distance between D3 and D7-branes. After tachyon condensation a supersymmetric ground state is formed: a D3/D7 bound state corresponding to an Abelian non-linear (non-commutative) instanton. In this model the existence of a non-vanishing cosmological constant is associated with the resolution of the instanton singularity. We discuss a possible embedding of this model into a compactified M-theory setup.Comment: 30 pages, 4 figures, LaTeX; v2, minor typos corrected, one reference adde

Transport properties of strongly correlated metals:a dynamical mean-field approach

The temperature dependence of the transport properties of the metallic phase of a frustrated Hubbard model on the hypercubic lattice at half-filling are calculated. Dynamical mean-field theory, which maps the Hubbard model onto a single impurity Anderson model that is solved self-consistently, and becomes exact in the limit of large dimensionality, is used. As the temperature increases there is a smooth crossover from coherent Fermi liquid excitations at low temperatures to incoherent excitations at high temperatures. This crossover leads to a non-monotonic temperature dependence for the resistance, thermopower, and Hall coefficient, unlike in conventional metals. The resistance smoothly increases from a quadratic temperature dependence at low temperatures to large values which can exceed the Mott-Ioffe-Regel value, hbar a/e^2 (where "a" is a lattice constant) associated with mean-free paths less than a lattice constant. Further signatures of the thermal destruction of quasiparticle excitations are a peak in the thermopower and the absence of a Drude peak in the optical conductivity. The results presented here are relevant to a wide range of strongly correlated metals, including transition metal oxides, strontium ruthenates, and organic metals.Comment: 19 pages, 9 eps figure

Strongly Hyperbolic Extensions of the ADM Hamiltonian

The ADM Hamiltonian formulation of general relativity with prescribed lapse and shift is a weakly hyperbolic system of partial differential equations. In general weakly hyperbolic systems are not mathematically well posed. For well posedness, the theory should be reformulated so that the complete system, evolution equations plus gauge conditions, is (at least) strongly hyperbolic. Traditionally, reformulation has been carried out at the level of equations of motion. This typically destroys the variational and Hamiltonian structures of the theory. Here I show that one can extend the ADM formalism to (i) incorporate the gauge conditions as dynamical equations and (ii) affect the hyperbolicity of the complete system, all while maintaining a Hamiltonian description. The extended ADM formulation is used to obtain a strongly hyperbolic Hamiltonian description of Einstein's theory that is generally covariant under spatial diffeomorphisms and time reparametrizations, and has physical characteristics. The extended Hamiltonian formulation with 1+log slicing and gamma--driver shift conditions is weakly hyperbolic.Comment: This version contains minor corrections and clarifications. The format has been changed to conform with IOP styl

Closed circuits : kinship, neighborhood and incarceration in urban Portugal

The notion that prisons are a ‘world apart’, with their walls severing prisoners from their external relationships, and incarceration an interruption, ‘time away’ spent in a separate social universe, has provided an adequate framework for understanding the social realities of imprisonment in the past. But it has also created an analytical dead angle that prevents us from identifying the ramifying social effects of concentrated incarceration upon both the prison and heavily penalized lower-class neighborhoods. This article addresses these effects with data from an ethnographic revisit of a major women’s prison in Portugal, where the recomposition of the inmate population that has accompanied the rapid inflation of the country’s carceral population is especially pronounced and entails the activation of wide-ranging carceralized networks bringing kinship and neighborhood into the prison as well as the prison into the domestic world. The analysis focuses on the ways whereby these constellations have transformed the experience of confinement and the texture of correctional life, calling for a reconsideration of the theoretical status of the prison as a ‘total institution’ and for exploring anew the boundary that separates it (or not) from outside worlds.Wenner-Gren Foundation for Anthropological Research