Search results for "Active [Galaxies]"

The Garden and Landscape as an Interdisciplinary Resource Between Experimental Science and Artistic-Musical Expression: Analysis of Competence Develo…

2020

The garden is a major educational resource that can be used for all areas of knowledge from an interdisciplinary perspective as it reflects the complexity and interactions of the natural environment. This research was carried out in the academic years 2017-2018 and 2018-2019 with 418 participants of from the second, third, and fourth year of the Degree in Primary Education at the University of Valencia. The use of the garden and the landscape is analyzed as a non-formal context for training primary school teachers through sensory experiences that contribute to the development of scientific and artistic competencies. The study focused on the relationship between natural sounds and emotions t…

Optical security and encryption with totally incoherent light

2001

We present a method for securing and encrypting information optically by use of totally incoherent illumination. Encryption is performed with a multichannel optical processor working under natural (both temporal and spatially incoherent) light. In this way, the information that is to be secured can be codified by use of color signals and self-luminous displays. The encryption key is a phase-only mask, providing high security from counterfeiting. Output encrypted information is recorded as an intensity image that can be easily stored and transmitted optically or electrically. Decryption or authentication can also be performed optically or digitally. Experimental results are presented.

Amphiphilic Polysaccharide Block Copolymers for pH-Responsive Micellar Nanoparticles

2017

A full polysaccharide amphiphilic block copolymer was prepared from end group-functionalized dextrans using copper-mediated azide-alkyne click chemistry. Sufficient modification of the reducing end in both blocks was achieved by microwave-enhanced reductive amination in a borate-buffer/methanol solvent system. The combination of a hydrophilic dextran block with a hydrophobic acetalated dextran block results in an amphiphilic structure that turns water-soluble upon acid treatment. The material has a low critical micelle concentration and self-assembles in water to spherical micellar nanoparticles. The formed nanoparticles have a narrow size distribution below 70 nm in diameter and disassembl…

Theoretical spectroscopy of organic systems

1999

Abstract The complete active space (CAS) SCF method in conjunction with the multiconfigurational second-order perturbation theory (CASPT2) has been applied to study the electronically excited states of basic organic compounds. As shown in the lecture with a number of examples, the CASPT2 method is capable of yielding accurate results for relative energies and other properties of excited states, provided that flexible one-electron basis sets are employed. The applications comprise an ample range of systems and problems, including polyenes, conjugated and unconjugated dienes, alternant and nonalternant hydrocarbons, polyenals, etc. As a whole these studies enable both qualitative and quantita…

Theoretical absorption and emission spectra of 1H- and 2H-benzotriazole

2003

Excitation energies, dipole moments, and transition properties for the lowest-lying 1(π, π*) and 1(n, π*) electronic states of two benzotriazole tautomers have been studied at the complete active space (CAS) SCF and multiconfigurational second-order perturbation (CASPT2) levels. With these results, the UV absorption spectra of 1H- and 2H-benzotriazole were first described individually, and then they were considered simultaneously in order to better understand the experimental, observed spectrum of benzotriazole. Aspects of the fluorescence of the compound have been also analyzed. The spectrum of benzotriazole is finally related to those of other azo-compounds.

Cluster-based active learning for compact image classification

2010

In this paper, we consider active sampling to label pixels grouped with hierarchical clustering. The objective of the method is to match the data relationships discovered by the clustering algorithm with the user's desired class semantics. The first is represented as a complete tree to be pruned and the second is iteratively provided by the user. The active learning algorithm proposed searches the pruning of the tree that best matches the labels of the sampled points. By choosing the part of the tree to sample from according to current pruning's uncertainty, sampling is focused on most uncertain clusters. This way, large clusters for which the class membership is already fixed are no longer…

Biomaterials in periapical regeneration after microsurgical endodontics: A narrative review

2021

Background: The objective of this narrative review was to analyze the available scientific evidence regarding the application of biomaterials in endodontic microsurgery and its influence in post-surgical tissue repair. Material and Methods: The review question was Do biomaterials used in endodontic microsurgery influence post-surgical tissue repair and regeneration? Systematic MEDLINE/PubMed review was used to evaluate and present the results. Results: The search yielded 131 references, 82 of which were selected for full text review after reading the abstracts. After a manual search in the references of the articles selected, 52 references were eliminated. Finally, 30 articles were selected…

High-content analysis of oxygen reactive species and oxidative stress for toxicology in vitro

2010

Even free radicals should follow some rules: a guide to free radical research terminology and methodology.

2014

Free radicals and oxidants are now implicated in physiological responses and in several diseases. Given the wide range of expertise of free radical researchers, application of the greater understanding of chemistry has not been uniformly applied to biological studies. We suggest that some widely used methodologies and terminologies hamper progress and need to be addressed. We make the case for abandonment and judicious use of several methods and terms and suggest practical and viable alternatives. These changes are suggested in four areas: use of fluorescent dyes to identify and quantify reactive species, methods for measurement of lipid peroxidation in complex biological systems, claims of…

Effect of temperature and organic nutrients on the biodegradation of linear alkylbenzene sulfonate (LAS) during the composting of anaerobically diges…

2004

Limits on the application of biosolids (anaerobically processed sludges from wastewater treatment plants) as fertilizers for the amendment of soil are becoming greater because of the accumulation of recalcitrant substances, making necessary the use of techniques that bring the concentration of xenobiotics to lower concentrations than those permitted. In general, the biosolids composting process is sufficient to reduce the usual concentration of linear alkylbenzene sulfonates (LAS) to low levels. In this work, an assessment is made on the effect of temperature in the capacity of enriched bacterial populations to biodegrade LAS, together with the influence that the available nutrients may hav…