Chlorophyll fluorescence-based high-throughput phenotyping facilitates the genetic dissection of photosynthetic heat tolerance in African (Oryza glaberrima) and Asian (Oryza sativa) rice.

Acknowledgements We are grateful to the University of Nottingham glasshouse staff for their assistance with general plant maintenance. We acknowledge the insight of two anonymous reviews whose comments greatly improved this manuscript. JR and JNF were supported by the Palaeobenchmarking Resilient Agriculture Systems (PalaeoRAS) project funded by the Future Food Beacon of the University of Nottingham.Peer reviewedPostprin

Deeply dredged submarine HIMU glasses from the Tuvalu Islands, Polynesia: Implications for volatile budgets of recycled oceanic crust

Ocean island basalts (OIB) with extremely radiogenic Pb-isotopic signatures are melts of a mantle component called HIMU (high µ, high 238U/204Pb). Until now, deeply dredged submarine HIMU glasses have not been available, which has inhibited complete geochemical (in particular, volatile element) characterization of the HIMU mantle. We report major, trace and volatile element abundances in a suite of deeply dredged glasses from the Tuvalu Islands. Three Tuvalu glasses with the most extreme HIMU signatures have F/Nd ratios (35.6 ± 3.6) that are higher than the ratio (∼21) for global OIB and MORB, consistent with elevated F/Nd ratios in end-member HIMU Mangaia melt inclusions. The Tuvalu glasses with the most extreme HIMU composition have Cl/K (0.11–0.12), Br/Cl (0.0024), and I/Cl (5–6 × 10−5) ratios that preclude significant assimilation of seawater-derived Cl. The new HIMU glasses that are least degassed for H2O have low H2O/Ce ratios (75–84), similar to ratios identified in end-member OIB glasses with EM1 and EM2 signatures, but significantly lower than H2O/Ce ratios (119–245) previously measured in melt inclusions from Mangaia. CO2-H2O equilibrium solubility models suggest that these HIMU glasses (recovered in two different dredges at 2500–3600 m water depth) have eruption pressures of 295–400 bars. We argue that degassing is unlikely to significantly reduce the primary melt H2O. Thus, the lower H2O/Ce in the HIMU Tuvalu glasses is a mantle signature. We explore oceanic crust recycling as the origin of the low H2O/Ce (∼50–80) in the EM1, EM2, and HIMU mantle domains

A closer look at the uncertainty relation of position and momentum

We consider particles prepared by the von Neumann-L\"uders projection. For those particles the standard deviation of the momentum is discussed. We show that infinite standard deviations are not exceptions but rather typical. A necessary and sufficient condition for finite standard deviations is given. Finally, a new uncertainty relation is derived and it is shown that the latter cannot be improved.Comment: 3 pages, introduction shortened, content unchange

Energy relaxation of an excited electron gas in quantum wires: many-body electron LO-phonon coupling

We theoretically study energy relaxation via LO-phonon emission in an excited one-dimensional electron gas confined in a GaAs quantum wire structure. We find that the inclusion of phonon renormalization effects in the theory extends the LO-phonon dominated loss regime down to substantially lower temperatures. We show that a simple plasmon-pole approximation works well for this problem, and discuss implications of our results for low temperature electron heating experiments in quantum wires.Comment: 10 pages, RevTex, 4 figures included. Also available at http://www-cmg.physics.umd.edu/~lzheng

Fluctuation Theorems for Entropy Production and Heat Dissipation in Periodically Driven Markov Chains

Asymptotic fluctuation theorems are statements of a Gallavotti-Cohen symmetry in the rate function of either the time-averaged entropy production or heat dissipation of a process. Such theorems have been proved for various general classes of continuous-time deterministic and stochastic processes, but always under the assumption that the forces driving the system are time independent, and often relying on the existence of a limiting ergodic distribution. In this paper we extend the asymptotic fluctuation theorem for the first time to inhomogeneous continuous-time processes without a stationary distribution, considering specifically a finite state Markov chain driven by periodic transition rates. We find that for both entropy production and heat dissipation, the usual Gallavotti-Cohen symmetry of the rate function is generalized to an analogous relation between the rate functions of the original process and its corresponding backward process, in which the trajectory and the driving protocol have been time-reversed. The effect is that spontaneous positive fluctuations in the long time average of each quantity in the forward process are exponentially more likely than spontaneous negative fluctuations in the backward process, and vice-versa, revealing that the distributions of fluctuations in universes in which time moves forward and backward are related. As an additional result, the asymptotic time-averaged entropy production is obtained as the integral of a periodic entropy production rate that generalizes the constant rate pertaining to homogeneous dynamics

Correlations, compressibility, and capacitance in double-quantum-well systems in the quantum Hall regime

In the quantum Hall regime, electronic correlations in double-layer two-dimensional electron systems are strong because the kinetic energy is quenched by Landau quantization. In this article we point out that these correlations are reflected in the way the partitioning of charge between the two-layers responds to a bias potential. We report on illustrative calculations based on an unrestricted Hartree-Fock approximation which allows for spontaneous inter-layer phase coherence. The possibility of studying inter-layer correlations by capacitive coupling to separately contacted two-dimensional layers is discussed in detail.Comment: RevTex style, 21 pages, 6 postscript figures in a separate file; Phys. Rev. B (in press

N-body simulations of gravitational dynamics

We describe the astrophysical and numerical basis of N-body simulations, both of collisional stellar systems (dense star clusters and galactic centres) and collisionless stellar dynamics (galaxies and large-scale structure). We explain and discuss the state-of-the-art algorithms used for these quite different regimes, attempt to give a fair critique, and point out possible directions of future improvement and development. We briefly touch upon the history of N-body simulations and their most important results.Comment: invited review (28 pages), to appear in European Physics Journal Plu

Snipe taxonomy based on vocal and non-vocal sound displays: the South American Snipe is two species

We analysed breeding sounds of the two subspecies of South American Snipe Gallinago paraguaiae paraguaiae and Gallinago paraguaiae magellanica to determine whether they might be different species: loud vocalizations given on the ground, and the tail‐generated Winnow given in aerial display. Sounds of the two taxa differ qualitatively and quantitatively. Both taxa utter two types of ground call. In G. p. paraguaiae, the calls are bouts of identical sound elements repeated rhythmically and slowly (about five elements per second (Hz)) or rapidly (about 11 Hz). One call of G. p. magellanica is qualitatively similar to those of G. p. paraguaiae but sound elements are repeated more slowly (about 3 Hz). However, its other call type differs strikingly: it is a bout of rhythmically repeated sound couplets, each containing two kinds of sound element. The Winnow of G. p. paraguaiae is a series of sound elements that gradually increase in duration and energy; by contrast, that of G. p. magellanica has two or more kinds of sound element that roughly alternate and are repeated as sets, imparting a stuttering quality. Sounds of the related Puna Snipe (Gallinago andina) resemble but differ quantitatively from those of G. p. paraguaiae. Differences in breeding sounds of G. p. paraguaiae and G. p. magellanica are strong and hold throughout their geographical range. Therefore we suggest that the two taxa be considered different species: G. paraguaiae east of the Andes in much of South America except Patagonia, and G. magellanica in central and southern Chile, Argentina east of the Andes across Patagonia, and Falklands/Malvinas.Fil: Miller, Edward H.. Memorial University Of Newfoundland; CanadáFil: Areta, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Jaramillo, Alvaro. San Francisco Bay Bird Observatory; Estados UnidosFil: Imberti, Santiago. Asociación Ambiente Sur, Rio Gallegos; ArgentinaFil: Matus, Ricardo. Kilómetro 7 Sur; Chil

The Political Economy of Failure: The Euro as an International Currency

How do international currencies get established and consolidated? What domestic and international political foundations support an international currency? And what kinds of macro-economic flows enable an international currency? In this essay we consider these perennial questions of modern IPE scholarship in reverse order to ask whether the euro could ever have become, or seek to become, a true international currency rivalling the US dollar, used not only for passive foreign exchange reserves but also as a major commercial currency outside the EU. We argue that the EU lacks the will, the ideas and the capacity to promote the euro into the status of an international currency. In this article, we concentrate on this final issue of capacity, as the will and ideas issues have already been well explored. Capacity is an issue coeval with, if not prior to, the first two issues. The EU's current institutional arrangements and its economic geography create macro-economic consequences that diminish the euro's capacity to operate as a top currency. These conflicts go beyond the well-recognized issue that the euro-zone is not an optimum currency area. Examining the euro's debilities sheds light not only on the euro's (in)capacity to rival the dollar as an international currency, but also on the future of both the euro and the dollar in the aftermath of the euro-zone crisis

US hegemony and the origins of Japanese nuclear power : the politics of consent

This paper deploys the Gramscian concepts of hegemony and consent in order to explore the process whereby nuclear power was brought to Japan. The core argument is that nuclear power was brought to Japan as a consequence of US hegemony. Rather than a simple manifestation of one state exerting material ‘power over' another, bringing nuclear power to Japan involved a series of compromises worked out within and between state and civil society in both Japan and the USA. Ideologies of nationalism, imperialism and modernity underpinned the process, coalescing in post-war debates about the future trajectory of Japanese society, Japan's Cold War alliance with the USA and the role of nuclear power in both. Consent to nuclear power was secured through the generation of a psychological state in the public mind combining the fear of nuclear attack and the hope of unlimited consumption in a nuclear-fuelled post-modern world