Validation of LAI and assessment of winter wheat status using spectral data and vegetation indices from SPOT VEGETATION and simulated PROBA-V images

Due to the information gap between the VEGETATION sensors and Sentinel-3 mission, the Belgian state decided to build a small satellite, Project for Onboard Autonomy-Vegetation (PROBA-V), to ensure the continuity of the data record for vegetation studies. In this study, simulated PROBA-V data generated by the Landsat Thematic Mapper (TM) were used to evaluate the potential of this mission to assess winter wheat status. The root mean square error (RMSE) of PROBA-V's leaf area index (LAI), which was generated using the exponential method and the interpolation method, is 0.33 and 0.96 for March 2011 and 1.40 and 3.33 for May 2011, respectively. Système Pour l'Observation de la Terre (SPOT) VEGETATION's LAI does not show a significant relationship with the reference LAI values except for the LAI values during the stem elongation 100% phenological stage generated using the exponential method (correlation coefficient, r = 0.91; p = 0.01). For the tillering and stem elongation 100% phenological stages, linear regression models for the fraction of absorbed photosynthetically active radiation (FAPAR) with PROBA-V's normalized difference vegetation index (NDVI) were developed (coefficient of determination, R ², of 0.94 and 0.88). Exponential models for LAI (R ² of 0.91 and 0.93) and fresh weight of above-ground biomass (AGBf) (R ² of 0.90 and 0.93) with PROBA-V's near-infrared (NIR) and visible and near-infrared bands (VNIR B2) were developed accordingly. The assessment of winter wheat status showed that the highest and the lowest values of PROBA-V's simulated data (SD), i.e. NDVI, normalized difference water index (NDWI), and LAI of Field 2 and Field 4, correspond to the ground-measured biometric parameters.     

Bulge-Forming miRNases Cleave Oncogenic miRNAs at the Central Loop Region in a Sequence-Specific Manner

The selective degradation of disease-associated microRNA is promising for the development of new therapeutic approaches. In this study, we engineered a series of bulge-loop-forming oligonucleotides conjugated with catalytic peptide [(LeuArg)₂Gly]₂ (BC–miRNases) capable of recognizing and destroying oncogenic miR-17 and miR-21. The principle behind the design of BC–miRNase is the cleavage of miRNA at a three-nucleotide bulge loop that forms in the central loop region, which is essential for the biological competence of miRNA. A thorough study of mono- and bis-BC–miRNases (containing one or two catalytic peptides, respectively) revealed that: (i) the sequence of miRNA bulge loops and neighbouring motifs are of fundamental importance for efficient miRNA cleavage (i.e., motifs containing repeating pyrimidine–A bonds are more susceptible to cleavage); (ii) the incorporation of the second catalytic peptide in the same molecular scaffold increases the potency of BC–miRNase, providing a complete degradation of miR-17 within 72 h; (iii) the synergetic co-operation of BC–miRNases with RNase H accelerates the rate of miRNA catalytic cleavage by both the conjugate and the enzyme. Such synergy allows the rapid destruction of constantly emerging miRNA to maintain sufficient knockdown and achieve a desired therapeutic effect.     

Methodology to assess groundwater pollution conditions (current and pre-disposition) in the São Carlos and Ribeirão Preto regions,Brazil

The goal of the study was to establish a methodology for territorial zoning based on predicted groundwater pollution. The 31 attributes identified were divided into six different environmental components associated with the transport of contaminants to the geological medium. Two indices were obtained: the pre-disposition index (PI), and the potential pollution intensity index (PPII). The paper reports an assessment of the potential pollution of the groundwater in the sandstones of the Botucatu and Pirambóia Formations, Sao Paulo, Brazil. The region was divided into 447 units according to the type of land use, size of watershed and degree of lithological homogeneity. The units were assessed for potential pollution in the pre-disposition condition (based on geological/geotechnical data) and the complete condition (geological/geotechnical and situation specific data) using the analytical hierarchical process method. A high degree of pollution potential was established for 35 of the units in the complete condition and 157 units in the pre-disposition condition. The study has highlighted areas where attention to pollution control should be focused.      

Synergistic Effect in Selective Reduction of NO by Alkanes over Mechanically Mixed Oxide Catalysts

The process of selective catalytic reduction of nitrogen oxides by propane in the presence of O₂, as well as in the presence or absence of CO, was studied over series of commercial oxide catalysts used in petrochemical processes. For the first time synergistic effect was observed for catalytic systems consisting of mechanical mixtures of Cu–Zn–Ni–Al (catalyst I) + Fe–Cr (catalyst II) and Cu–Zn–Ni–Al (catalyst I) + Ni–Cr (catalyst III). The activity of these mixtures in nitrogen oxides reduction by propane was greater than that of individual components in each case. The worked-out catalytical systems showed high effectivity in the process of simultaneous removal of several toxic components: NO _x , CO, hydrocarbons – from model gas mixtures, as well as from real exhausts of automotive transport.     

Ru-Containing Polymeric Catalysts for Cellulose Conversion to Polyols

In this paper Ru-containing catalysts based on hypercrosslinked polystyrene (MN-270) and its functional analogues (MN-100 and MN-500) were studied for the first time in cellulose hydrolytic hydrogenation. The catalysts were characterized using transmission electron microscopy (TEM), high resolution TEM, and porosity measurements. Catalytic studies demonstrated that the catalyst containing 1.0 % Ru and based on MN-270 is the most active. The total yield of sorbitol and mannitol was 50 % on the average at 85 % cellulose conversion.     

High retention of polarization in polycrystalline M/PZT/M capacitors in the presence of depolarization field near grain boundaries

Recently, we reported on the photovoltaic current observed in poled capacitors with polycrystalline Pb(ZrTi)O(3) (PZT) films, where (111)-oriented PZT grains are separated by an ultrathin semiconductor PbO phase. This photocurrent is driven by the depolarization field, which is generated by residual uncompensated polarization charge located on grain boundaries near electrodes. We showed that the photocurrent can serve as a criterion of existence of the depolarization field and demonstrated that this field is retained in the film for at least one year. Here, we present new experimental and numerical results which confirm the proposed conception of the photovoltaic effect. We study the photocurrent depending on the kind of electrodes, preliminary illumination in an open-circuit regime, and light intensity of LED, and give evidence of retention of the depolarization field in the films for at least for one and one-half years. The numerical study of the photovoltaic effect at extremely high photogeneration rate shows that total compensation of the polarization charge by photoexcited carriers in these structures is impossible. This photovoltaic effect can be used for nondestructive readout in ferroelectric memory.