Incidence of Blossom-end Rot in Relation to Water-soluble Ca Concentration in Tomato Fruits as Affected by Ca Nutrition under Root Restriction

The rate of absorbed Ca to N was less than half of Enshi or Hoagland solution in tomato (Solanum lycopersicum Mill.) grown with restricted root zone volume in previous experiments. Tomato plants were grown in plastic pots containing 250 or 500ml of peat based medium with modified Enshi solutions containing 1, 2 or 4mM of Ca. The solutions were prepared by replacing a part of Ca(NO3)2・4H2O to NH4NO3. Although Ca concentration was higher than 2mM in drainage collected from plants supplied 1mM Ca solution, absorbed amount of Ca was very small and severe symptom of Ca deficiency was observed. Incidence of blossom-end rot (BER) increased with decrease in Ca concentration of the solution and yield decreased to 50% and 36% of 4mM control, in 2mM and 1mM plots, respectively. Among fractionated Ca in stem of lateral shoot, decrease in water-soluble fraction was remarkable compared to 1N NaCl- or 0.6N HCl-soluble fractions. Tomato plants were then grown with modified solutions containing 1~4mM of Ca and fractionated Ca was determined for distal half of fruits. With decrease in solution Ca, fruit Ca decreased in all fractions, and days to BER incidence after flowering also decreased. Significant relationship was found only between the water-soluble Ca concentration in fruit tissue and rate of BER incidence. Thus water-soluble Ca in tomato fruit may closely relate to BER incidence, and an efficient tool to estimate the potential risk of BER may possibly be developed by determining the Ca fraction in the stem of lateral shoots.根域制限下におけるトマトの養分吸収を調査した結果，培養液中Caの多くは排液とともに排出され，Ｎに対するCaの吸収比率は園試処方やHoagland処方中の比率の50%以下であった．そこで，園試処方培養液中のCa(NO3)2･4H2Oの一部をNH4NO3に置換してCa濃度１，２，４ﾋの培養液を作成し，日射比例給液制御下で ‘ハウス桃太郎’の根城制限栽培（培地容量250，500 ㎖）を行った．培養液のCa濃度が１ﾋであっても排液中のCa濃度が２ﾋよりも高く推移したが，Ca吸収量は極めて少なく，著しいCa欠乏症状が現れた．低Ca濃度区では尻腐れ果が多発し，１ﾋ区では第３果房より上段の果実は全て尻腐れ果となり，第９果房までの収量は２ﾋ区，１ﾋ区でそれぞれ４ﾋ区の50%，36%に低下した．腋芽茎中のCa濃度の低下は0.6N-NaCl可溶性画分や0.6N-HCl可溶性画分と比較して水溶性画分の低下が著しかった．そこで，Ca濃度が１～４ﾋの培養液を用いて点滴栽培を行い，果実中のCa濃度を分画して定量した．果実頂部のCa濃度はいずれの画分においても培養液中Ca濃度が低いほど低く，開花から尻腐れ症状が発生するまでの日数も短くなった．尻腐れ果発生率と果頂部の水溶性Ca濃度との間にのみ有意な負の相関が認められた．以上のことから，果実の水溶性Ca濃度がトマトの尻腐れ果発生リスクの大小に大きくかかわっており，植物体の水溶性Ca濃度測定は尻腐れ果発生防止のためのCa栄養診断に応用できる可能性が高いと考えられる

Stability of Simple Periodic Orbits and Chaos in a Fermi -- Pasta -- Ulam Lattice

We investigate the connection between local and global dynamics in the Fermi -- Pasta -- Ulam (FPU) $\beta$ -- model from the point of view of stability of its simplest periodic orbits (SPOs). In particular, we show that there is a relatively high $q$ mode $(q=2(N+1)/{3})$ of the linear lattice, having one particle fixed every two oppositely moving ones (called SPO2 here), which can be exactly continued to the nonlinear case for $N=5+3m, m=0,1,2,...$ and whose first destabilization, $E_{2u}$, as the energy (or $\beta$) increases for {\it any} fixed $N$, practically {\it coincides} with the onset of a ``weak'' form of chaos preceding the break down of FPU recurrences, as predicted recently in a similar study of the continuation of a very low ($q=3$) mode of the corresponding linear chain. This energy threshold per particle behaves like $\frac{E_{2u}}{N}\propto N^{-2}$. We also follow exactly the properties of another SPO (with $q=(N+1)/{2}$) in which fixed and moving particles are interchanged (called SPO1 here) and which destabilizes at higher energies than SPO2, since $\frac{E_{1u}}{N}\propto N^{-1}$. We find that, immediately after their first destabilization, these SPOs have different (positive) Lyapunov spectra in their vicinity. However, as the energy increases further (at fixed $N$), these spectra converge to {\it the same} exponentially decreasing function, thus providing strong evidence that the chaotic regions around SPO1 and SPO2 have ``merged'' and large scale chaos has spread throughout the lattice.Comment: Physical Review E, 18 pages, 6 figure

Moist static energy: definition, reference constants, a conservation law, and effects on buoyancy

Atmospheric thermodynamic variables are commonly computed under approximations. Although exact formulas are available, they are rarely used. This paper addresses some potential issues arising when using approximate formulas by taking the moist static energy as an example. An important conclusion is that the temperature dependence of latent heat must be taken into account. We also demonstrate that the zero-point energies of various species do not affect the moist static energy budget. The use of an exact formula for moist static energy increases its surface value by 15 K for a typical tropical sounding. However, the change of the parcel buoyancy by using the exact formula is less dramatic, although not negligible. Calculating, for example, the CAPE for convection parameterization, the use of an exact formula is likely not be critical for the practical purposes, but quantitative discrepancies can be as large as 50–200 J/kg

Synthesis, X-ray Crystal Structures, and Solid-state Fluorescence Properties of Novel 5,5-Dialkyl-9-dibutylamino-5H-benzo[b]naphtho[1,2-d]furan-6-one and 3,3-Dialkyl-9-dibutylamino-3H-benzo[kl]xanthen-2-one

After publication use "Published in European Journal of Organic Chemistry, Issue 18, 2008, pp. 3085-3094, WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Dielectric responses of the layered cobalt oxysulfide Sr_2Cu_2CoO_2S_2 with CoO_2 square-planes

We have studied the dielectric responses of the layered cobalt oxysulfide Sr$_2$Cu$_2$CoO$_2$S$_2$ with the CoO$_2$ square-planes. With decreasing temperature below the N\'eel temperature, the resistivity increases like a semiconductor, and the thermopower decreases like a metal. The dielectric constant is highly dependent on temperature, and the dielectric relaxation is systematically changed with temperature, which is strongly correlated to the magnetic states. These behaviors suggest that carriers distributed homogeneously in the paramagnetic state at high temperatures are expelled from the antiferromagnetically ordered spin domain below the N\'eel temperature.Comment: 3 pages, 4 eps figures, to be published in J. Appl. Phy

Geometrical properties of local dynamics in Hamiltonian systems: the Generalized Alignment Index (GALI) method

We investigate the detailed dynamics of multidimensional Hamiltonian systems by studying the evolution of volume elements formed by unit deviation vectors about their orbits. The behavior of these volumes is strongly influenced by the regular or chaotic nature of the motion, the number of deviation vectors, their linear (in)dependence and the spectrum of Lyapunov exponents. The different time evolution of these volumes can be used to identify rapidly and efficiently the nature of the dynamics, leading to the introduction of quantities that clearly distinguish between chaotic behavior and quasiperiodic motion on $N$-dimensional tori. More specifically we introduce the Generalized Alignment Index of order $k$ (GALI$_k$) as the volume of a generalized parallelepiped, whose edges are $k$ initially linearly independent unit deviation vectors from the studied orbit whose magnitude is normalized to unity at every time step. The GALI$_k$ is a generalization of the Smaller Alignment Index (SALI) (GALI$_2$ $\propto$ SALI). However, GALI$_k$ provides significantly more detailed information on the local dynamics, allows for a faster and clearer distinction between order and chaos than SALI and works even in cases where the SALI method is inconclusive.Comment: 45 pages, 10 figures, accepted for publication in Physica

Quasi-stationary chaotic states in multi-dimensional Hamiltonian systems

We study numerically statistical distributions of sums of chaotic orbit coordinates, viewed as independent random variables, in weakly chaotic regimes of three multi-dimensional Hamiltonian systems: Two Fermi-Pasta-Ulam (FPU-$\beta$) oscillator chains with different boundary conditions and numbers of particles and a microplasma of identical ions confined in a Penning trap and repelled by mutual Coulomb interactions. For the FPU systems we show that, when chaos is limited within "small size" phase space regions, statistical distributions of sums of chaotic variables are well approximated for surprisingly long times (typically up to $t\approx10^6$) by a $q$-Gaussian ($1<q<3$) distribution and tend to a Gaussian ($q=1$) for longer times, as the orbits eventually enter into "large size" chaotic domains. However, in agreement with other studies, we find in certain cases that the $q$-Gaussian is not the only possible distribution that can fit the data, as our sums may be better approximated by a different so-called "crossover" function attributed to finite-size effects. In the case of the microplasma Hamiltonian, we make use of these $q$-Gaussian distributions to identify two energy regimes of "weak chaos"-one where the system melts and one where it transforms from liquid to a gas state-by observing where the $q$-index of the distribution increases significantly above the $q=1$ value of strong chaos.Comment: 32 pages, 13 figures, Submitted for publication to Physica

Tropical Cyclogenesis Sensitivity to Environmental Parameters in Radiative-Convective Equilibrium

In this study, the relationship between the likelihood of tropical cyclogenesis and external environmental forcings is explored in the simplest idealized modelling framework possible: radiative-convective equilibrium on a doubly periodic f-plane. In such an environment, control of the equilibrium environmental sounding is reduced to three parameters: the sea-surface temperature, the Coriolis parameter, and the imposed background surface wind speed. Cloud-resolving mesoscale model simulations are used to generate environments of radiative-convective equilibrium determined by these three factors. The favourability of these environments for tropical cyclogenesis is measured in three ways: in terms of the maximum potential intensity (MPI) of the sounding, based on the thermodynamic theory of Emanuel; in terms of the ‘genesis potential’ determined by an empirical genesis parameter; and in terms of the propensity of weak initial vortices in these environments to form into tropical cyclones. The simulated environments of radiative—convective equilibrium with no vertical wind shear are found to be very favourable for tropical cyclogenesis. Weak initial vortices always transition to a tropical cyclone, even for rather low sea-surface temperatures. However, the time required for these vortices to make the transition from a weak, mid-level vortex to a rapidly developing tropical cyclone decreases as the MPI increases, indicating the importance of MPI in enhancing the frequency of cyclogenesis. The relationship between this ‘time to genesis’ and the thermodynamic parameters is explored. The time to genesis is found to be very highly (negatively) correlated to MPI, with little or no relationship to convective instability, Coriolis parameter, mid-level humidity, or the empirical genesis parameter. In some cases, tropical cyclones are found to form spontaneously from random convection. This formation is due to a cooperative interaction between large-scale moisture, long-wave radiation, and locally enhanced sea-surface fluxes, similar to the ‘aggregation’ of convection found in previous studies.National Science Foundation (U.S.) (Grant ATM-0432067

The key physical parameters governing frictional dissipation in a precipitating atmosphere

Precipitation generates small-scale turbulent air flows the energy of which ultimately dissipates to heat. The power of this process has previously been estimated to be around 2-4 W m-2 in the tropics: a value comparable in magnitude to the dynamic power of the global circulation. Here we suggest that this previous power estimate is approximately double the true figure. Our result reflects a revised evaluation of the mean precipitation path length Hp. We investigate the dependence of Hp on surface temperature,relative humidity,temperature lapse rate and degree of condensation in the ascending air. We find that the degree of condensation,defined as the relative change of the saturated water vapor mixing ratio in the region of condensation, is a major factor determining Hp. We estimate from theory that the mean large-scale rate of frictional dissipation associated with total precipitation in the tropics lies between 1 and 2 W m-2 and show that our estimate is supported by empirical evidence. We show that under terrestrial conditions frictional dissipation constitutes a minor fraction of the dynamic power of condensation-induced atmospheric circulation,which is estimated to be at least 2.5 times larger. However,because Hp increases with surface temperature Ts, the rate of frictional dissipation would exceed that of condensation-induced dynamics, and thus block major circulation, at Ts >~320 K in a moist adiabatic atmosphere.Comment: 12 pp, 2 figure