The Equation of State for Cool Relativistic Two-Constituent Superfluid Dynamics

The natural relativistic generalisation of Landau's two constituent superfluid theory can be formulated in terms of a Lagrangian $L$ that is given as a function of the entropy current 4-vector $s^\rho$ and the gradient $\nabla\varphi$ of the superfluid phase scalar. It is shown that in the ``cool" regime, for which the entropy is attributable just to phonons (not rotons), the Lagrangian function $L(\vec s, \nabla\varphi)$ is given by an expression of the form $L=P-3\psi$ where $P$ represents the pressure as a function just of $\nabla\varphi$ in the (isotropic) cold limit. The entropy current dependent contribution $\psi$ represents the generalised pressure of the (non-isotropic) phonon gas, which is obtained as the negative of the corresponding grand potential energy per unit volume, whose explicit form has a simple algebraic dependence on the sound or ``phonon" speed $c_P$ that is determined by the cold pressure function $P$.Comment: 26 pages, RevTeX, no figures, published in Phys. Rev. D. 15 May 199

Pliocene Marine Transgressions of Northern Alaska: Circumarctic Correlations and Paleoclimatic Interpretations

At least three marine transgressions of Piliocene age are recorded by littoral to inner-shelf sediments of the Gubik Formation, which mantles the Arctic Coastal Plain of northern Alaska. The three recognized transgressions were eustatic high sea levels that, from oldest to youngest, are informally named the Colvillian, Bigbendian, and Fishcreekian transgressions. The geochronology is based up amino acid geochemistry, paleomagnetic studies, vertebrate and invertebrate paleontology, and strontium isotope age estimates. Pollen, plant macrofossils, and marine vertebrate and inventebrate remains indicate that these transgressions occurred when the Arctic was at least intermittently much warmer than it is now. The Colvillian transgression took place at sometime between 2.48 and 2.7 Ma, when adjacent coastal areas supported an open boreal forest or spruce-birch-woodland with scattered pine and rare fir and hemlock. The Bigbendian transgression occurred about 2.48 Ma. Climate conditions were probably slightly cooler than during the Colvillian transgression, but probably too warm for permafrost and too warm for even seasonal sea ice in the region. Nearby vegetation was open spruce-birch woodland or parkland, possibly with rare scattered pine. The Fishcreekian transgression took place sometime between 2.14 and 2.48 Ma and was also characterized by warm marine conditions without sea ice. During the waning stages of this transgression, however, terrestrial conditions were relatively cool, and coastal vegetation was herbaceous tundra with scattered larch trees in the vicinity. Other marine units from this time period occur around the Arctic Basin. The three oldest transgressions recognized from the Seward Peninsula may be broadly correlated with the three Piliocene transgresions of the Arctic Coastal Plain. The Tusatuvayam beds in Kamchatka possibly correlate with one of the two younger transgressions of northern Alaska. The non-marine Worth Point Formation of Banks Island may be younger than all three of the transgressions of the Arctic Coastal Plain, and marine sediment of the Beaufort Formation on Meighen Island is slightly older than the Colvillian transgression. None of the Piliocene marine units on Baffin Island can be confidently correlated with the high sea level events of northern Alaska. The upper Kap Kobenhavn Formation and the upper Loden Elv Formation of Greenland most likely correlate with the Fishcreekian transgression.Key words: Arctic, amino acids, Pliocene, Pleistocene, paleoclimate, marine transgressions, sea level, Alaska, Gubik FormationRÉSUMÉ. Au moins trois transgressions marines datant du pliocène sont inscrites dans les sediments allant du littoral à l’interieur de la plateforme de la formation Gubik, qui recouvre la plaine côtière arctique de l’Alaska septentrional. Les trois transgressions reconnues correspondent à des fortes remontées du niveau de la mer et ont reçu, dans l’ordre chronologique, les noms informels de formations "colvillienne", "bigbendienne" et "fishcreekienne". La géochronologie s’appuie sur la géochimie des acides aminés, des études paléomagnétiques, la paléontologie de vertébrés et d’invertébrés ainsi que sur des estimations de datation à l’isotope du strontium. Les pollens, les macrofossiles végétaux ainsi que les restes de vertébrés et d’invertébrés marins indiquent que ces transgressions se sont produites alors que l’Arctique  était, pour le moins de façon intermittente, beaucoup plus chaud que maintenant. La transgression colvillienne a eu lieu à un moment donné entre 2,48 et 2,7 Ma, alors que les zones côtières adjacentes supportaient une forêt boréale ouverte ou des bois d’épinettes-bouleaux avec quelques pins éparpillés et de rares sapins et pruches. La transgression bigbendienne a eu lieu aux alentours de 2,48 Ma. Les conditions climatiques étaient probablement un peut plus froides que durant la transgression colvillienne, mais aussi probablement trop chaudes pour le pergélisol et en tout cas trop chaudes pour permettre la création d’une banquise - même saisonnière - dans la region. La végétation proche consistait en des bois ou des forêts-parcs d’épinettes-bouleaux avec peut-êtrequelques pins éparpillés. La transgression fishcreekienne a pris place à un moment donné entre 2,14 et 2,48 Ma et a aussi été caractérisée par des conditions marines chaudes sans banquise. Durant le declin de cette transgression cependant, les conditions climatiques terrestres étaient relativement froides et la végétation côtière se composait de toundra herbacée semée de mélèzes aux alentours. D’autres unites marines datant de cette période se trouvent autour du bassin de l’Arctique. Les trois plus anciennes transgressions établies dans la péninsule Seward peuvent être dans l’ensemble corrélées avec les trois transgressions du pliocène de la plaine côtière arctique. Les couches Tusatuvayam dans la Kamchatka sont peut-être corréler avec l’une des deux transgressions les plus jeunes de l’Alaska septentrional. La formation non marine Worth Point de l’île de Banks est peut-être plus jeune que les trois transgressions de la plaine côtière arctique et les sediments marins de la formation de Beaufort dans l’île Meighen sont légèrement plus anciens que la transgression colvillienne. On ne peut avec certitude corréler aucune des unités marines du pliocène sur l’île de Baffin avec les événements eustatiques qui ont amené une  élévation du niveau marin dans l’Alaska septentrional. La partie supérieure de la formation Kap Kobenhavn et celle de la formation Loden Elv du Groenland sont probablement à corréler avec latransgression fishcreekienne.Mots clés: Arctique, acides aminés, pliocène, pléistocène. paléoclimat, transgressions marines, niveau de la mer, Alaska, formation de Gubi

Gravitational radiation from monopoles connected by strings

Monopole-antimonopole pairs connected by strings can be formed as topological defects in a sequence of cosmological phase transitions. Such hybrid defects typically decay early in the history of the universe but can still generate an observable background of gravitational waves. We study the spectrum of gravitational radiation from these objects both analytically and numerically, concentrating on the simplest case of an oscillating pair connected by a straight string.Comment: 18 pages, RevTex and 2 postscript figures. Submitted to Phys. Rev.

Instabilities in the two-dimensional cubic nonlinear Schrodinger equation

The two-dimensional cubic nonlinear Schrodinger equation (NLS) can be used as a model of phenomena in physical systems ranging from waves on deep water to pulses in optical fibers. In this paper, we establish that every one-dimensional traveling wave solution of NLS with trivial phase is unstable with respect to some infinitesimal perturbation with two-dimensional structure. If the coefficients of the linear dispersion terms have the same sign then the only unstable perturbations have transverse wavelength longer than a well-defined cut-off. If the coefficients of the linear dispersion terms have opposite signs, then there is no such cut-off and as the wavelength decreases, the maximum growth rate approaches a well-defined limit.Comment: 4 pages, 4 figure

Administration of human chorionic gonadotropin at embryo transfer induced ovulation of a first-wave dominant follicle and increased progesterone and transfer pregnancy rates

Beef Cattle Research, 2011 is known as Cattlemen’s Day, 2011Embryo transfer (ET) has become more widespread in recent years as a way to improve cattle genetics. According to the annual statistical survey of the American Embryo Transfer Association, more than 200,000 fresh and frozen bovine embryos were transferred in 2008. But despite advancements in reproductive technologies that have occurred since ET was commercialized in the 1970s, industrywide pregnancy rates are only 62.4 and 56.9% for fresh and frozen-thawed ET, respectively. Using ET helps avoid problems from failed fertilization; however, fertilization failure has been characterized as a relatively unimportant factor of pregnancy loss. Approximately 10% of pregnancy failures resulted from fertilization failure and another 10% from failed embryo development. Approximately 20 to 25% of the pregnancy loss in an ET program could be characterized as early embryonic loss

On the gravitational, dilatonic and axionic radiative damping of cosmic strings

We study the radiation reaction on cosmic strings due to the emission of dilatonic, gravitational and axionic waves. After verifying the (on average) conservative nature of the time-symmetric self-interactions, we concentrate on the finite radiation damping force associated with the half-retarded minus half-advanced ``reactive'' fields. We revisit a recent proposal of using a ``local back reaction approximation'' for the reactive fields. Using dimensional continuation as convenient technical tool, we find, contrary to previous claims, that this proposal leads to antidamping in the case of the axionic field, and to zero (integrated) damping in the case of the gravitational field. One gets normal positive damping only in the case of the dilatonic field. We propose to use a suitably modified version of the local dilatonic radiation reaction as a substitute for the exact (non-local) gravitational radiation reaction. The incorporation of such a local approximation to gravitational radiation reaction should allow one to complete, in a computationally non-intensive way, string network simulations and to give better estimates of the amount and spectrum of gravitational radiation emitted by a cosmologically evolving network of massive strings.Comment: 48 pages, RevTex, epsfig, 1 figure; clarification of the domain of validity of the perturbative derivation of the string equations of motion, and of their renormalizabilit

Can invasions occur without change? A comparison of G-matrices and selection in the peach-potato aphid, Myzus persicae

Most evolutionary research on biological invasions has focused on changes seen between the native and invaded range for a particular species. However, it is likely that species that live in human-modified habitats in their native range might have evolved specific adaptations to those environments, which increase the likelihood of establishment and spread in similar human-altered environments. From a quantitative genetic perspective, this hypothesis suggests that both native and introduced populations should reside at or near the same adaptive peak. Therefore, we should observe no overall changes in the G (genetic variance–covariance) matrices between native and introduced ranges, and stabilizing selection on fitness-related traits in all populations. We tested these predictions comparing three populations of the worldwide pest Myzus persicae from the Middle East (native range) and the UK and Chile (separately introduced ranges). In general, our results provide mixed support for this idea, but further comparisons of other species are needed. In particular, we found that there has been some limited evolution in the studied traits, with the Middle East population differing from the UK and Chilean populations. This was reflected in the structure of the G-matrices, in which Chile differed from both UK and Middle East populations. Furthermore, the amount of genetic variation was massively reduced in Chile in comparison with UK and Middle East populations. Finally, we found no detectable selection on any trait in the three populations, but clones from the introduced ranges started to reproduce later, were smaller, had smaller offspring, and had lower reproductive fitness than clones from the native range

Inhomogeneities in dusty universe - a possible alternative to dark energy?

There have been of late renewed debates on the role of inhomogeneities to explain the observed late acceleration of the universe. We have looked into the problem analytically with the help of the well known spherically symmetric but inhomogeneous Lemaitre-Tolman-Bondi(LTB) model generalised to higher dimensions. It is observed that in contrast to the claim made by Kolb et al the presence of inhomogeneities as well as extra dimensions can not reverse the signature of the deceleration parameter if the matter field obeys the energy conditions. The well known Raychaudhuri equation also points to the same result. Without solving the field equations explicitly it can, however, be shown that although the total deceleration is positive everywhere nevertheless it does not exclude the possibility of having radial acceleration, even in the pure dust universe, if the angular scale factor is decelerating fast enough and vice versa. Moreover it is found that introduction of extra dimensions can not reverse the scenario. To the contrary it actually helps the decelerating process.Comment: 14 pages, 4 figure

Hawking Radiation as Tunneling for Extremal and Rotating Black Holes

The issue concerning semi-classical methods recently developed in deriving the conditions for Hawking radiation as tunneling, is revisited and applied also to rotating black hole solutions as well as to the extremal cases. It is noticed how the tunneling method fixes the temperature of extremal black hole to be zero, unlike the Euclidean regularity method that allows an arbitrary compactification period. A comparison with other approaches is presented.Comment: 17 pages, Latex document, typos corrected, four more references, improved discussion in section

Relativistic superfluid models for rotating neutron stars

This article starts by providing an introductory overview of the theoretical mechanics of rotating neutron stars as developped to account for the frequency variations, and particularly the discontinuous glitches, observed in pulsars. The theory suggests, and the observations seem to confirm, that an essential role is played by the interaction between the solid crust and inner layers whose superfluid nature allows them to rotate independently. However many significant details remain to be clarified, even in much studied cases such as the Crab and Vela. The second part of this article is more technical, concentrating on just one of the many physical aspects that needs further development, namely the provision of a satisfactorily relativistic (local but not microscopic) treatment of the effects of the neutron superfluidity that is involved.Comment: 42 pages LateX. Contribution to Physics of Neutron Star Interiors, ed. D. Blasche, N.K. Glendenning, A. Sedrakian (ECT workshop, Trento, June 2000