Expression patterns of ethylene biosynthesis genes from banana during fruit ripening and in relationship with finger drop

Banana finger drop is expressed as a dislodgement of individual fruits from the hand at the pedicel rupture area. As bananas fruit are marketed in hands of generally 4?9 fruits, this postharvest disorder considerably reduces the commercial value of the product. Together with a burst of ethylene production, finger drop phenomenon was found to be one of the main features closely associated with banana ripening. We have shown that finger drop process occur early after ripening induction and imply ethylene?regulated gene. In this study, we investigate at molecular level the putative relationship between ethylene and finger drop processes during ripening of Cavendish banana fruit. To this end, expression of ethylene biosynthesis genes (MaACO1, MaACO2, MaACS1, MaACS2, MaACS3 and MaACS4) was examined at median area (control zone) and compared to that in the pedicel rupture area (drop zone). During the 4 first days following the ripening induction, transcripts of all genes were detected in both zones, but accumulated differentially. MaACO2 mRNA levels did not change in either zone. Levels of MaACO1, MaACS1, MaACS2, MaACS4 mRNAs accumulated highly in the drop zone. A high the mRNA of MaACS3 gene accumulated highly in drop zone only at the harvest time. One day after ripening induction, this level decreased drastically at comparable level to that observed at median zone, and remain constant in both zones throughout postharvest ripening. The results demonstrate that finger drop process involved ripening ethylene biosynthesis. They also suggest that ethylene can be one of the regulator cues of finger drop process. (Résumé d'auteur

A Jang Equation Approach to the Penrose Inequality

We introduce a generalized version of the Jang equation, designed for the general case of the Penrose Inequality in the setting of an asymptotically flat space-like hypersurface of a spacetime satisfying the dominat energy condition. The appropriate existence and regularity results are established in the special case of spherically symmetric Cauchy data, and are applied to give a new proof of the general Penrose Inequality for these data sets. When appropriately coupled with an inverse mean curvature flow, analogous existence and regularity results for the associated system of equations in the nonspherical setting would yield a proof of the full Penrose Conjecture. Thus it remains as an important and challenging open problem to determine whether this system does indeed admit the desired solutions.Comment: 31 page

Spontaneous spin textures in dipolar spinor condensates

We have mapped out a detailed phase diagram that shows the ground state structure of a spin-1 condensate with magnetic dipole-dipole interactions. We show that the interplay between the dipolar and the spin-exchange interactions induces a rich variety of quantum phases that exhibit spontaneous magnetic ordering in the form of intricate spin textures.Comment: 4.1 pages, 4 figure

Domain studies of CoCr with perpendicular anisotropy

R.F. Magnetron sputtered CoCr films (79/21 at%) with various thicknesses are magnetically characterized. The domain structure is observed by digitally enhanced Kerr microscopy and depends on the Hc/Hk values of the samples. For low and high coercivity films a comparison is made between the measured VSM hysteresis, domain period and a theoretical domain model. The domain shape is a function of the magnetic history of the sample and the bending created by the deposition process

Diophantine approximation on Veech surfaces

We show that Y. Cheung's general $Z$-continued fractions can be adapted to give approximation by saddle connection vectors for any compact translation surface. That is, we show the finiteness of his Minkowski constant for any compact translation surface. Furthermore, we show that for a Veech surface in standard form, each component of any saddle connection vector dominates its conjugates. The saddle connection continued fractions then allow one to recognize certain transcendental directions by their developments

Rational, Replacement, and Local Invariants of a Group Action

The paper presents a new algorithmic construction of a finite generating set of rational invariants for the rational action of an algebraic group on the affine space. The construction provides an algebraic counterpart of the moving frame method in differential geometry. The generating set of rational invariants appears as the coefficients of a Groebner basis, reduction with respect to which allows to express a rational invariant in terms of the generators. The replacement invariants, introduced in the paper, are tuples of algebraic functions of the rational invariants. Any invariant, whether rational, algebraic or local, can be can be rewritten terms of replacement invariants by a simple substitution.Comment: 37 page

Neutron monitors and muon detectors for solar modulation studies: 2. ϕ\phi time series

The level of solar modulation at different times (related to the solar activity) is a central question of solar and galactic cosmic-ray physics. In the first paper of this series, we have established a correspondence between the uncertainties on ground-based detectors count rates and the parameter $\phi$ (modulation level in the force-field approximation) reconstructed from these count rates. In this second paper, we detail a procedure to obtain a reference $\phi$ time series from neutron monitor data. We show that we can have an unbiased and accurate $\phi$ reconstruction ($\Delta\phi/\phi\simeq 10\%$). We also discuss the potential of Bonner spheres spectrometers and muon detectors to provide $\phi$ time series. Two by-products of this calculation are updated $\phi$ values for the cosmic-ray database and a web interface to retrieve and plot $\phi$ from the 50's to today (\url{http://lpsc.in2p3.fr/crdb}).Comment: 15 pages, 5 figures, 2 tables. AdSR, in press. Web interface to get modulation parameter phi(t): new tab in http://lpsc.in2p3.fr/crd