Leaf and stand-level carbon uptake of a Mediterranean forest estimated using the satellite-derived reflectance indices EVI and PRI

Various aspects of global environmental change affect plant photosynthesis, the primary carbon input in ecosystems. Thus, accurate methods of measuring plant photosynthesis are important. Remotely sensed spectral indices can monitor in detail the green biomass of ecosystems, which provides a measure of potential photosynthetic capacity. In evergreen vegetation types, however, such as Mediterranean forests, the amount of green biomass changes little during the growing season and, therefore, changes in green biomass are not responsible for changes in photosynthetic rates in those forests. This study examined the net photosynthetic rates and the diametric increment of stems in a Mediterranean forest dominated by Quercus ilex using three spectral indices (normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), and photochemical reflectance index (PRI)) derived from Moderate Resolution Imaging Spectroradiometer (MODIS) sensors. Average annual EVI accounted for 83% of the variability of the diametric increment of Q. ilex stems over a 10 year period. NDVI was marginally correlated with the diametric increment of stems. This study was the first to identify a significant correlation between net photosynthetic rates and radiation use efficiency at the leaf level using PRI derived from satellite data analysed at the ecosystem level. These results suggest that each spectral index provided different and complementary information about ecosystem carbon uptake in a Mediterranean Q. ilex forest.     

The photoreceptive cells of the pineal gland in adult zebrafish (Danio rerio)

The zebrafish pineal gland plays a fundamental role in the regulation of the circadian rhythm through the melatonin secretion. The pinealocytes, also called photoreceptive cells, are considered the morphofunctional unit of pineal gland. In literature, the anatomical features, the cellular characteristics, and the pinealocytes morphology of zebrafish pineal gland have not been previously described in detail. Therefore, this study was undertaken to analyze the structure and ultrastructure, as well as the immunohistochemical profile of the zebrafish pineal gland with particular reference to the pinealocytes. Here, we demonstrated, using RT-PCR, immunohistochemistry and transmission electron microscopy, the expression of the mRNA for rhodopsin in the pineal gland of zebrafish, as well as its cellular localization exclusively in the pinealocytes of adult zebrafish. Moreover, the ultrastructural observations demonstrated that the pinealocytes were constituted by an outer segment with numerous lamellar membranes, an inner segment with many mitochondria, and a basal pole with the synapses. Our results taken together demonstrated a central role of zebrafish pinealocytes in the control of pineal gland functions.     

3D Simulation of Nano-Imprint Lithography

A proof of concept study of the feasibility of fully three-dimensional (3D) time-dependent simulation of nano-imprint lithography of polymer melt, where the polymer is treated as a structured liquid, has been presented. Considering the flow physics of the polymer as a structured liquid, we have followed the line initiated by de Gennes, using a Molecular Stress Function model of the Doi and Edwards type. We have used a 3D Lagrangian Galerkin finite element methods implemented on a parallel computer architecture. In a Lagrangian techniques, the node point follows the particle movement, allowing for the movement of free surfaces or interfaces. We have extended the method to handle the dynamic movement of the contact line between the polymer melt and stamp during mold filling.     

Analysing metals in bottle‐grade poly(ethylene terephthalate) by X‐ray fluorescence spectrometry

After a rigorous cleaning process, recycled food‐grade poly(ethylene terephthalate) (PET), can be mixed with virgin PET resin in different concentrations and used for packaging of soft drinks. Therefore, it is important to have an experimental method to distinguish the presence of recycled polymer in a batch and to check its “true quality.” One of the issues to be verified is the presence of inorganic contaminants due to the recycling process. X‐ray fluorescence technique is one alternative for this kind of analysis. The results obtained in this work show that bottle‐grade PET samples (PET‐btg) are made either via direct esterification or by a transesterification process. Samples that were subjected to thermo‐mechanical processings (superclean® processing, PET‐btg blends processed in our laboratory and soft drink PET packaging) present Fe Kα emission lines with higher intensities than those presented by virgin bottle‐grade PET. After applying principal component analysis, it can be concluded that Fe is an intrinsic contaminant after the recycling process, furnishing a way to indicate class separations of PET‐btg. A calibration and validation partial least squares model was constructed to predict the weight percent of post‐consumption bottle‐grade PET in commercial PET samples. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Structural Data on the Periplasmic Aldehyde Oxidoreductase PaoABC from Escherichia coli: SAXS and Preliminary X-ray Crystallography Analysis

The periplasmic aldehyde oxidoreductase PaoABC from Escherichia coli is a molybdenum enzyme involved in detoxification of aldehydes in the cell. It is an example of an αβγ heterotrimeric enzyme of the xanthine oxidase family of enzymes which does not dimerize via its molybdenum cofactor binding domain. In order to structurally characterize PaoABC, X-ray crystallography and small angle X-ray scattering (SAXS) have been carried out. The protein crystallizes in the presence of 20% (w/v) polyethylene glycol 3350 using the hanging-drop vapour diffusion method. Although crystals were initially twinned, several experiments were done to overcome twinning and lowering the crystallization temperature (293 K to 277 K) was the solution to the problem. The non-twinned crystals used to solve the structure diffract X-rays to beyond 1.80 Å and belong to the C2 space group, with cell parameters a = 109.42 Å, b = 78.08 Å, c = 151.77 Å, β = 99.77°, and one molecule in the asymmetric unit. A molecular replacement solution was found for each subunit separately, using several proteins as search models. SAXS data of PaoABC were also collected showing that, in solution, the protein is also an αβγ heterotrimer.     

Forward collision resolution-a technique for random multiple-accessto the adder channel

Consider M-Choose-T communications: T users or less, out of M potential users, are chosen at random to simultaneously transmit binary data over a common channel. A method for constructing codes that achieve error-free M-Choose-T communication over the noiseless adder channel (AC), at a nominal rate of 1/T bits per channel symbol per active user, is described and an efficient decoding procedure is presented. The use of such codes is referred to as forward collision resolution (FCR), as it enables correct decoding of collided messages without retransmissions. For any given T a code is available that yields a stable throughput arbitrarily close to 1 message/slot. Furthermore, if the occurrence of collisions is made known to the transmitters, such a throughput can be maintained for arbitrary T,T⩽M as well. If such feedback is not available, and T is random, the probability of an unresolved collision is significantly smaller than the probability of a collision in an uncoded system, at comparable message-arrival and information rates     

Galerkin and Least Squares Methods to Solve a 3D Convection–Diffusion–Reaction Equation with Variable Coefficients

This study addresses how to implement the Galerkin finite element and least square finite element methods using auxiliary equations to solve the partial differential equation numerically, which models the convection–diffusion–reaction, set on a steady 3D domain. In the spatial discretization, hexahedral elements with eight (linear element) and 27 (quadratic element) nodes were used, in which Lagrange interpolation functions were adopted in local coordinates. Turning all the formulation of the problem of global coordinates into local coordinates, the Gauss–Legendre quadrature method was used to integrate coefficients of the element matrices numerically. In addition to the formulation by the two methods, a computer code was implemented to simulate the phenomenon proposed. By using analytical solutions, sundry numerical error analysis was performed from L₂ norm (domain–average error) and L_∞ norm (domain–top error), thus validating the numerical results. A real case is proposed and assessed.     

Synthesis and characterization of aniline copolymers containing carboxylic groups and their application as sensitizer and hole conductor in solar cells

Copolymers of m-aminobenzoic acid and o-anisidine doped with p-toluenesulphonic acid in different proportions were successfully synthesized by oxidative polymerization. The copolymers were characterized by FT-IR, UV–vis, ¹H NMR and EPR spectroscopies, cyclic voltammetry, conductivity and SEM. The copolymer with equivalent amounts of the monomers o-anisidine and m-aminobenzoic acid presented the highest conductivity, The EPR analyses and SEM images show that this copolymer provides more homogeneous films with particle size distribution of approximately 1–2 μm. The copolymer with a high fraction of o-anisidine gives rises to films with larger particle sizes and a more defined electrochemical process. The m-aminobenzoic acid monomer was intentionally chosen in order to promote a better electronic coupling between the conducting copolymer and the TiO₂ surface. The copolymers were tested as both sensitizers and hole conducting materials in dye-sensitized solar cells. The device assembled using the copolymer with the highest proportion of m-aminobenzoic acid units as sensitizer produced the highest photocurrent (I_sc = 0.254 mA cm^?2) and photovoltage (V_oc = 0.252 V) at 100 mW cm^?2. The energy diagram shows that although the electronic injection from the conducting polymer excited state is an allowed process the regeneration of the positive charges created after the electron transfer process is forbidden, thus explaining the low efficiency of solar energy conversion. When this copolymer was applied as a hole conducting material, an improvement in the V_oc to 0.4 V, was observed, indicating that this material is more suitable for charge transport when applied in this type of solar cells.     

Inference on some parametric functions in the univeriate lognormal diffusion process with exogenous factors

In this paper we consider, for the univariate lognormal diffusion process with exogenous factors, the inference for some parametric functions that include as particular cases the trend and the covariance function of the process. Concretely, we obtain the UMVU estimators of these functions and the efficiency of them relative to the corresponding ML estimators. Finally, we conclude with an application to a particular case of exogenous factor. This research was partially supported by DGYCIT PB97-0855 and BFM2000-0602 Grants.     

Morphology of sealant/enamel interface after surface treatment with bioactive glass

The purpose of this study was to analyze, by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM), the morphology of sealant/enamel interface after surface treatment with Biosilicate. Before pits and fissures sealing, the occlusal surfaces of 10 sound human molars were sectioned perpendicularly at the fissures in order to obtain three slices for each tooth. Slices were randomly assigned into three groups (n = 10) according to sealing protocol: Group 1‐ Acid etching + Biosilicate + glass ionomer‐based sealant (Clinpro XT Varnish, 3M ESPE); Group 2‐ Acid etching + glass ionomer‐based sealant (Clinpro XT Varnish, 3M ESPE); Group 3‐ No sealing. All slices were subjected to thermal cycling (5,000 cycles; 5–55°C; dwell time: 30s). Half of the slices from each group (n = 5) were analyzed by CLSM and the other half by SEM. Groups 1 and 2 were also submitted to EDS analysis and their data were evaluated by Two‐Way ANOVA e Tukey's test (α=5%). EDS data analysis showed higher amounts of silicon (Si) ions than calcium (Ca) ions in Group 1 (P < 0.05); Group 2 presented higher amounts (P < 0.05) of Ca ions than Si ions. It may be concluded that the use of Biosilicate for surface treatment did not affect the morphology of glass ionomer‐based sealant/enamel interfaces. Microsc. Res. Tech. 78:1062–1068, 2015. © 2015 Wiley Periodicals, Inc.