External Shape Differences between Sympatric Populations of Commercial Clams <Emphasis Type="Italic">Tapes decussatus</Emphasis> and <Emphasis Type="Italic">T. philippinarum</Emphasis>

The actual Italian production of clams is chiefly sustained by the native Tapes decussatus and the fortuitously imported Tapes philippinarum. Both species are commercialized as “Vongola verace”, but the commercial value of T. philippinarum is lower. The discrimination of species by sight is usually difficult and it cannot be done by observation based on shell morphology but only when animals open their valves hence displaying the two siphons. In this study, we propose a new, noninvasive method to discriminate individuals of both species based on the analysis of the external shape of their shells. Accordingly, in sympatric populations at two sites of the Po river outlet, we have chosen individuals (63 for T. decussatus and 57 for T. philippinarum) of comparable commercial size for which a certain genetic discrimination was previously done. Pictures of the left side valve were taken for all specimens. Their profiles were analyzed with the elliptic Fourier analysis. The mean outline for each species was graphically extracted. The coefficients of the harmonic equations were analyzed by multivariate classification (partial least squares discriminant analysis [PLSDA]). Results showed a high percentage of correct classification of individuals of both species (96.6%). Contour analysis reflected the overall shell shape and thus identified morphological aspects that were difficult to recognize and quantify in sight. The high percentage of correct classifications obtained by combining the analysis of elliptic Fourier harmonics with PLSDA demonstrated the feasibility of this method to discriminate species with a high level of resemblance.     

Root Exposure to 5-Aminolevulinic Acid (ALA) Affects Leaf Element Accumulation,Isoprene Emission,Phytohormonal Balance,and Photosynthesis of Salt-Stressed Arundo donax

Arundo donax has been recognized as a promising crop for biomass production on marginal lands due to its superior productivity and stress tolerance. However, salt stress negatively impacts A. donax growth and photosynthesis. In this study, we tested whether the tolerance of A. donax to salinity stress can be enhanced by the addition of 5-aminolevulinic acid (ALA), a known promoter of plant growth and abiotic stress tolerance. Our results indicated that root exposure to ALA increased the ALA levels in leaves along the A. donax plant profile. ALA enhanced Na⁺ accumulation in the roots of salt-stressed plants and, at the same time, lowered Na⁺ concentration in leaves, while a reduced callose amount was found in the root tissue. ALA also improved the photosynthetic performance of salt-stressed apical leaves by stimulating stomatal opening and preventing an increase in the ratio between abscisic acid (ABA) and indol-3-acetic acid (IAA), without affecting leaf methanol emission and plant growth. Supply of ALA to the roots reduced isoprene fluxes from leaves of non-stressed plants, while it sustained isoprene fluxes along the profile of salt-stressed A. donax. Thus, ALA likely interacted with the methylerythritol 4-phosphate (MEP) pathway and modulate the synthesis of either ABA or isoprene under stressful conditions. Overall, our study highlights the effectiveness of ALA supply through soil fertirrigation in preserving the young apical developing leaves from the detrimental effects of salt stress, thus helping of A. donax to cope with salinity and favoring the recovery of the whole plant once the stress is removed.     

Explicit versus implicit method for radiative heat transfer in gray and diffuse enclosures

The paper presents an explicit formulation of the radiative problem in gray enclosures. The method is based on a series expansion that derives the mutual radiation factors by means of summation of the contributions to the radiative thermal exchange given by the multi-reflection process. A mathematical proof that the infinite expansion converges to the well known solution, given by the implicit formulation and based on radiosities balance, is provided. Moreover a parametric analysis of the approximation induced by the explicit algorithm, as a result of the truncation order in the calculation of the series expansion, is carried out. The analysis shows how the precision of every approximation order is mainly related to the surface averaged infrared reflectance and is weakly dependent on the reflectance distribution. For high emissive and low reflecting surfaces, very few summations are required to meet high precision; the same level of precision is achievable also with medium and high reflecting surfaces, by increasing the truncation order of the series. More generally, the explicit formulation provides an alternative approach to problems involving multi-reflecting cavities in different engineering applications, from heat transfer to optics.     

Optimization of the procedure to burn textile fabrics by cone calorimeter: Part I. Combustion behavior of polyester

The aim of this study was the optimization of cone calorimeter to determine the burning behavior of textile fabrics. In particular, the combustion behavior of commercial polyester textile fabrics with varying densities was studied in terms of time to ignition (TTI), heat release rate (HRR), and relative peak (pkHRR) were monitored. Reproducibility and repeatability of the data have been verified by the influence of instrument variable including incident heat flux, the temperature of ceramic backing pads and retaining grid used during sample mounting as well as sample weight (as the number of fabric layers), the density of textiles, and the relative humidity. A low reproducibility has been obtained when a wire grid was not used to stabilize samples during the tests. The effects of these variables on TTI and pkHRR were observed. Copyright © 2010 John Wiley & Sons, Ltd.     

An automatic procedure for the synthesis and optimization of very low-frequency Gm–C integrators

Fully integrated low frequency filters are critical cells that should be carefully designed in order to avoid excessive area occupation. In this work we propose an automatic procedure capable of optimizing the design of G_m?CC integrators, which constitute the basis of a wide class of G_m?CC filters. The optimization target is minimizing the cell area with constraints on input range and low frequency noise. Lower and upper bounds can be fixed to most quantities and design parameters in order to avoid solutions that are not compatible with the physical limitations of the process. The program has been developed within the MATLAB^? platform, exploiting the optimization toolbox. The effect of several important design parameters on the optimization of low frequency integrators has been investigated using the proposed routine. The strong interaction between noise and low frequency constraints has been demonstrated, showing the impressive impact of strict noise specifications on the occupied area. The actual effectiveness of parameters such as the current division factor or approaches such as flicker noise rejection by means of chopper modulation has been investigated. Examples of integrator synthesis, performed using the proposed procedure configured with the parameters of a commercial CMOS process, are presented. The consistence between the characteristics of the cells and the initial specifications has been checked using electrical simulations showing a maximum discrepancy with the initial specifications of nearly 80%. A semi-manual method to refine the synthesized cells and improve the accuracy is proposed.     

A Model for Liquid-Striped Liquid Phase Separation in Liquids of Anisotropic Polarons

The phase separation between a striped polaron liquid at the particular density and a high density polaron liquid is described by a modified Van der Waals scheme. The striped polaron liquid represents the pseudo gap matter or Wigner-like polaron phase at 1/8 doping in cuprate superconductors. The model includes the tendency of pseudo-Jahn-Teller polarons to form anisotropic directional bonds at a preferential volume with the formation of different “liquid phases”. The model gives the coexistence of a first low density polaron striped liquid and a second high density liquid that appears in cuprate superconductors for doping larger than 1/8. We discuss how the strength of anisotropic bonds controls the variation the phase separation scenarios for complex systems in the presence of a quantum critical point where the phase separation vanishes.     

Multi-agent quality of experience control

International Journal of Control, Automation and Systems - In the framework of the Future Internet, the aim of the Quality of Experience (QoE) Control functionalities is to track the personalized...