The dimensional nature of same–different discrimination behavior in pigeons.

We studied the dimensional nature of same–different discrimination behavior in pigeons. Birds first learned to discriminate between simultaneously presented displays of 16 identical items (Same arrays) and 16 nonidentical items (Different arrays), conditional on the color of the background. After discrimination mastery, we tested the birds with Mixture arrays comprising both identical and nonidentical items. Accuracy increased and reaction time decreased as the disparity in entropy (a measure of variability) between the arrays increased. As well, within each entropy disparity level, lower entropy values were more discriminable than higher entropy values. These results accord with a logarithmic relation between entropy and discriminative behavior and, thus, with the idea that the discrimination of Same from Different arrays follows Weber's Law. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Effect of diets containing adenosine, guanosine, inosine or xanthosine on the nucleotide content of Artemia. Influence of mycophenolic acid

Artemia uses the stored diguanosine tetraphosphate as a source of adenine and guanine nucleotides during development from the encysted gastrula to the free swimming larva. Further development of the larvae depends on a dietary source of purine rings. We have investigated the growth of Artemia in axenic cultures supplemented with 0.6 mg ml-1 of adenosine, guanosine, inosine or xanthosine. The total protein and soluble nucleotide content of Artemia grown in the presence of adenosine, guanosine or inosine was very similar, around (2 A260 units and 500 mg protein) and (4 A260 units and 1000 mg protein) after 4 and 6 days of postlarval development, respectively. The nucleotide pattern of those extracts subjected to HPLC were almost identical, the major peaks corresponding to ATP, ADP and AMP. Other nucleotides, not well characterized, were also present in those extracts. Mycophenolic acid (10 micrograms ml-1) inhibited the growth of Artemia (as measured by their protein and soluble nucleotide content) in the presence of adenosine and inosine as the purine source, and had no appreciable effect in the presence of guanosine. A quantitative analysis of the chromatographic peaks obtained from Artemia grown in the presence of any of the three nucleosides +/- mycophenolic acid showed that the effect of the antibiotic on each one of the chromatographic peaks was very similar, suggesting that Artemia, and probably other organisms as well, tend to maintain a balance between all nucleotides and to adjust the overall level to the limiting step(s) in their rates of synthesis/interconversion. Xanthosine was not able to support the development of Artemia.     

Estimation of forest biomass from light detection and ranging data by using machine learning

The use of data driven predictive systems is becoming widespread as innovations in machine learning techniques have allowed the training of increasingly sophisticated models via the available data. The light detection and ranging (LiDAR) remote sensing technique is being increasingly applied to obtain informative terrain maps, due to its ability to collect large amounts of data with satisfactory accuracy. This paper focuses on the application of machine‐learning‐based predictive systems for the extraction of biomass information from LiDAR data. Biomass information has inmense ecological and economical value. We demonstrate the estimation of the Pinus radiata biomass in the Arratia‐Nervión region (Spain). Biomass estimation is considered a regression problem in which the ground truth for some specific sample sites is available. The promising results obtained in this study indicate that LiDAR data can be used to carry out detailed biomass mappings by the extrapolation of the models trained in this study.     

Local Preirradiation of Infarcted Cardiac Tissue Substantially Enhances Cell Engraftment

The success of cell therapy for the treatment of myocardial infarction depends on finding novel approaches that can substantially implement the engraftment of the transplanted cells. In order to enhance cell engraftment, most studies have focused on the pretreatment of transplantable cells. Here we have considered an alternative approach that involves the preconditioning of infarcted heart tissue to reduce endogenous cell activity and thus provide an advantage to our exogenous cells. This treatment is routinely used in other tissues such as bone marrow and skeletal muscle to improve cell engraftment, but it has never been taken in cardiac tissue. To avoid long-term cardiotoxicity induced by full heart irradiation we developed a rat model of a catheter-based heart irradiation system to locally impact a delimited region of the infarcted cardiac tissue. As proof of concept, we transferred ZsGreen⁺ iPSCs in the infarcted heart, due to their ease of use and detection. We found a very significant increase in cell engraftment in preirradiated rats. In this study, we demonstrate for the first time that preconditioning the infarcted cardiac tissue with local irradiation can substantially enhance cell engraftment.     

Conditional same-different discrimination by pigeons: Acquisition and generalization to novel and few-item displays.

The authors explored whether pigeons can learn to discriminate simultaneously presented arrays of 16 identical (Same) visual items from arrays of 16 nonidentical (Different) visual items, when the correct choice was conditional on the presence of another cue: the color of the background. In one experiment, pigeons rapidly learned this task and, after training with arrays created from a 72-icon set, they exhibited nearly perfect transfer to novel testing arrays. In a second experiment, pigeons’ accuracy to 24-, 20-, 12-, and 8-icon arrays during later testing remained as high as accuracy to training arrays; although accuracy declined with 4- and 2-icon arrays, it was still significantly above chance. In both experiments, pigeons’ choice reaction time scores nicely complemented their choice accuracy scores. These results suggest that the conditional discrimination procedure is well suited to disclose same-different discrimination in pigeons and to elucidate the interaction between perception and abstraction in conceptual learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

New genotypes of table olives: profile of bioactive compounds

New table olive genotypes (48) coming from a cross‐breeding programme were evaluated. Most of the fruit traits covered a wide range of variability on the set of genotypes, fruit weight (1.1–9.7 g), pulp‐to‐pit ratio (1.7–10.0), fruit shape (1.0–1.6) and oil content (1.3–15.2%). This is the first time that healthy compounds such as triterpenic acids and phenolic compounds have also been evaluated in olive progenies. Genotypes were stored for 2 months in sterilised brine (5% NaCl and 0.5% acetic acid). A high amount of maslinic (685.0–1394.2 mg kg^?1 olive flesh) and oleanolic acids (275.3–817.9 mg kg^?1 olive flesh) was found in the flesh of olives stored. The main oleosidic and phenolic compounds evaluated in brines were hydroxytyrosol (1.9–8.4 mmol L^?1), hydroxytyrosol glucosides (0.4–19.8 mmol L^?1), oleuropein (0.0–4.7 mmol L^?1) and the antimicrobial compounds, dialdehydic form of decarboxymethyl elenolic acid linked to hydroxytyrosol (0.0–3.4 mmol L^?1) and decarboxymethyl elenolic acid (0.0–1.7 mmol L^?1), the latter two being observed in only ten genotypes. The wide range of variation observed for most compounds indicates that the contents of these healthy compounds may be used as selection criteria in table olive breeding programmes.     

Synthesis and characterization of reactive copolymeric microgels

Hydrogels whose diameters range in the nanosize scale were synthesized by precipitation copolymerization of 4‐nitrophenol acrylate (NPA) with methacrylamide (MeAM) and N‐isopropylacrylamide (NIPAM). The polymerization reaction process was followed by attenuated total reflectance Fourier‐transform infrared spectrometry (ATR‐FTIR) and the conversion was studied by UV‐vis spectrometry. Poly(NPA‐co‐MeAM) and poly(NPA‐co‐NIPAM) microgels were characterized by proton nuclear magnetic resonance (¹H‐NMR) spectrometry. The thermal properties were studied by both thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis. Transmission electron microscopy (TEM) of these microgels showed that the copolymer is located in spherical particles with a moderate polydispersity. The average particle diameter and the particle size distribution were measured in acetone by quasi‐elastic light scattering (QELS), which indicated a mean diameter close to 50 nm. Copyright © 2005 Society of Chemical Industry     

Enantioselective Synthesis of 4‐Isoxazolines by 1,3‐Dipolar Cycloadditions of Nitrones to Alkynals Catalyzed by Fluorodiphenylmethylpyrrolidines

The first organocatalytic enantioselective 1,3‐dipolar reaction between nitrones and alkynals catalyzed by (S)‐2‐(fluorodiphenylmethyl)pyrrolidine to give 4‐isoxazolines (2,3‐dihydroisoxazoles) with high enantiomeric excess, excellent yields and low catalyst loading (1–5 mol%) is presented. The catalytic loading could be reduced to 1 mol% with only slight increases in reaction times.     

Hydrolysis of poly(l-lactide)/ZnO nanocomposites with antimicrobial activity

This work investigates the effect of the incorporation of zinc oxide (ZnO) nanoparticles within a poly(l -lactic acid) (PLLA) matrix as an approach to speed up the hydrolysis of PLLA film surfaces. Hydrolysis was done by immersing nanocomposite films having 1 wt % of ZnO in 0.25 M sodium hydroxide at 58 °C. This concentration has been selected as it provides the maximum changes of physicochemical properties of hosting PLLA matrix. The evolution of the thermal properties, ultraviolet–visible transparency, wettability, and morphology were monitored at different time points. The amount of carboxylic groups onto PLLA/ZnO surfaces was quantified according to Toludine Blue-O assay. Hydrolysis was mainly limited to film surfaces, which were grafted by carboxylic groups as a result of the random scission of PLLA ester linkages. The presence of such functional groups decreases the inherent surface hydrophobicity of PLLA at short hydrolysis times. On the contrary, long hydrolyses increase the hydrophobicity as a result of surface nanostructuring induced by the degradation of PLLA to water-soluble oligomers. Overall, ZnO nanoparticles enable shorter surface modification times and provide a quick approach for the modification on the polarity of polylactide surfaces. The potential of hydrolyzed films as antimicrobial materials was explored using Gram-negative Escherichia coli as a model. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47786.