Search

Solar activity (SA) oscillations over the past millennia are analyzed and extrapolated based on reconstructed solar-related records. Here, simple recurrent models of SA signal are applied and tested. The consequent results strongly suggest: (a) the existence of multi-millennial (~ 9500 years) scale solar oscillations, and (b) their persistence, over at least the last glacial-interglacial cycle. This empirical modelling of solar recurrent oscillations has also provided a consequent multi-millennial-scale experimental forecast, suggesting a solar decreasing trend toward Grand (Super) Minimum conditions for the upcoming period, AD2050-2250 (AD 3750-4450). Also, a recurrent linear influence of solar variation on continental tropical climate (CTC) has been assessed for the last 20 kyr, and extrapolated for the next centuries. Taking into account the importance of these estimated SA scenarios a comparison is made with other SA forecasts, and their possible associated astronomical forcing and influences on past and future CTC discussed. [ABSTRACT FROM AUTHOR]

The parameters to be taken into account when installing a drip irrigation system include the diameters of piping to be used in the irrigation installation. Certain applications developed for PC permit an approximate calculation of these diameters outside the installation environment, which makes on-site optimization of the system difficult. This paper presents a software application developed for Android mobile devices by which the user can immediately evaluate the responsiveness of all of the available optimum commercial diameters to operational changes, such as changing water demands (e.g., cultivation, water needs, and spacing), types of emitters used in the installation, or lateral feeding (from an extreme or from an intermediate point). The input data mainly required by the application are: emitter flow rates, the number of emitters, the space between emitters, the average pressure in the lateral, and the pressure tolerance. As a result, the application indicates if each irrigation lateral is valid or not for the situation provided by the user, and displays some graphics of the pressures in the lateral that indicate the pressures at the system's extremities, which permits identification of the critical points of the irrigation lateral. [ABSTRACT FROM AUTHOR]

Quantum scattering by a one-dimensional odd potential proportional to the square of the distance to the origin is considered. The Schrödinger equation is solved exactly and explicit algebraic expressions of the wavefunction are given. A complete discussion of the scattering function reveals the existence of Gamow (decaying) states and of resonances. [ABSTRACT FROM AUTHOR]

The P2Y14 receptor is a relatively broadly expressed G protein-coupled receptor that is prominently associated with immune and inflammatory cells as well as with many epithelia. This receptor historically was thought to be activated selectively by UDP-glucose and other UDP-sugars. However, UDP is also a very potent agonist of this receptor, and may prove to be one of its most important cognate activators. [ABSTRACT FROM AUTHOR]

The asymptotic expansion of the hypergeometric function [sub 2]F[sub 1] (a, b;c;z/b) in the case of quasiconfluence, i.e., for b → ∞ is revised. A very simple expansion, in terms of a semiasymptotic sequence of polynomials, is presented. Some properties of those polynomials are discussed. [ABSTRACT FROM AUTHOR]

The possibility of defining travelling waves in isotropic potentials going to −∞ at infinite distances and presenting a depression at the origin is examined. Resonances in such potentials are in correspondence with enhancements of the time delay, as it happens for finite-range potentials. [Copyright &y& Elsevier]

The possibility of expanding the S matrix in a multiple-reflection series (Debye expansion) is shown for an arbitrary-shape short-range potential. Ambiguity in the definition of outgoing and incoming waves inside the potential leads to an infinity of expansions. These are analyzed in a simple example (square well or barrier) in order to characterize the correct choice of outgoing and incoming waves. [ABSTRACT FROM AUTHOR]

The dependence of the Whittaker function M[SUBκ, μ] (z) on the parameter κ is considered. A convergent expansion in ascending powers and an asymptotic expansion in descending powers of κ are discussed. Some properties of the coefficients of the convergent expansion are shown. [ABSTRACT FROM AUTHOR]

The possibility of confining a quantum particle in an optical potential, the imaginary part of which would be related to the existence of inelastic reaction channels coupled to the elastic one, is considered. Pure imaginary potentials of various (constant, linear, and parabolic) radial shapes are studied. The numerical dependence of the energies and mean-lives of the confined states is explicitly shown. Analytical expressions for such dependence are also given in some cases. [ABSTRACT FROM AUTHOR]

Purpose To analyze the morphological changes of corneal nerves and its influence on corneal epithelial wound healing in a lacrimodeficient dry eye model in the guinea‐pig. Methods Corneal nerve architecture and the rate of corneal epithelial wound healing were studied in guinea‐pigs to whom the main lacrimal gland was removed 4 weeks before (dry eye) and in control animals. Eyes were fixed, cryoprotected and incubated with neuronal class III Beta‐tubulin antibody. Epithelial migration rate (EMR) and estimated time of healing (ETH) were calculated for 2mm‐diameter epithelial corneal debridations stained with fluorescein, photographed regularly until complete closure and analyzed with image processing software. Results Density (16±6 vs 27±11 nerves/mm2) and length (115±45 vs 186±74 µm) of subbasal nerves decreased significantly in dry eye. Subbasal nerves were less branched and tortuous. Epithelial nerve terminals were also reduced. EMR decreased significantly (63±4 vs 110±1 µm/h) and ETH increased significantly (38.6±1.8 vs 20.1±0.1 h) in dry eye. Conclusion The morphological appearance and the decreased density, length and branches of corneal subbasal nerves are suggestive of corneal nerve degeneration at 4 weeks after lacrimal gland removal. Lacrimodeficient eyes presented also a slowing‐down in corneal epithelial wound healing suggesting an early trophic defect consecutive to nerve damage. (Supported by: SAF2008‐00529, CSD2007‐00023, BFU2008‐04425, BFU2009‐07793 and RETICS RD07/0062/0012 from Ministerio de Ciencia e Innovación, Spain, and the Leonardo da Vinci Lifelong Learning Program.) [ABSTRACT FROM AUTHOR]