1,956 research outputs found
Association of Social Data
According to the ILO International Labour Organisation about 218 million children between 5 and 17 years working in the world of which 50 have jobs at risk On the basis of this information arising questions on how to understand and find the factors that comprise the ratings of child labour and which properties are important to analyze these cases With the use of data mining techniques to find valid patterns on Brazilian social databases were evaluated data of child labour in the State of Tocantins located north of Brazil with a territory of 277 thousand and composed of 139 cities This work aims to identify factors that are deterministic to the practice of child labour and their relationships with financial indicators educational social and regional generating information that are not explicit in the Government database thus enabling a better monitoring and updating policies to that en
Critical Assessment Of Enhancement Factor Measurements In Surface-enhanced Raman Scattering On Different Substrates
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The SERS enhancement factor (SERS-EF) is one of the most important parameters that characterizes the ability of a given substrate to enhance the Raman signal for SERS applications. The comparison of SERS intensities and SERS-EF values across different substrates is a common practice to unravel the performance of a given substrate. In this study, it is shown that such a comparison may lack significance if we compare substrates of very distinct nature and optical properties. It is specifically shown that the SERS-EF values for static substrates (e.g. immobilized metallic nanostructures) cannot be compared to those of dynamic ones (e.g. colloidal metal nanoparticle solutions), and that the optical properties for the latter show strong dependence on the metal-molecule interaction dynamics. The most representative experimental results concerning the dynamic substrates have been supported by generalized Mie theory simulations, which are tools used to describe the substrate complexity and the microscopic information not usually taken into account.17332129421301Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
One Pot Use of Combilipases for Full Modification of Oils and Fats: Multifunctional and Heterogeneous Substrates
Lipases are among the most utilized enzymes in biocatalysis. In many instances, the main reason for their use is their high specificity or selectivity. However, when full modification of a multifunctional and heterogeneous substrate is pursued, enzyme selectivity and specificity become a problem. This is the case of hydrolysis of oils and fats to produce free fatty acids or their alcoholysis to produce biodiesel, which can be considered cascade reactions. In these cases, to the original heterogeneity of the substrate, the presence of intermediate products, such as diglycerides or monoglycerides, can be an additional drawback. Using these heterogeneous substrates, enzyme specificity can promote that some substrates (initial substrates or intermediate products) may not be recognized as such (in the worst case scenario they may be acting as inhibitors) by the enzyme, causing yields and reaction rates to drop. To solve this situation, a mixture of lipases with different specificity, selectivity and differently affected by the reaction conditions can offer much better results than the use of a single lipase exhibiting a very high initial activity or even the best global reaction course. This mixture of lipases from different sources has been called “combilipases” and is becoming increasingly popular. They include the use of liquid lipase formulations or immobilized lipases. In some instances, the lipases have been coimmobilized. Some discussion is offered regarding the problems that this coimmobilization may give rise to, and some strategies to solve some of these problems are proposed. The use of combilipases in the future may be extended to other processes and enzymes.This research was funded by Ministerio de Ciencia e Innovación-Spanish Government (project number CTQ2017-86170-R) and Generalitat Valenciana (PROMETEO/2018/076)
Enzyme production of d-gluconic acid and glucose oxidase: successful tales of cascade reactions
This review mainly focuses on the use of glucose oxidase in the production of D-gluconic acid, which is a reactant of undoubtable interest in different industrial areas. The enzyme has been used in numerous instances as a model reaction to study the problems of oxygen supply in bioreactors. One of the main topics in this review is the problem of the generated side product, hydrogen peroxide, as it is an enzyme-inactivating reagent. Different ways to remove hydrogen peroxide have been used, such as metal catalysts and use of whole cells; however, the preferred method is the coupling glucose oxidase with catalase. The different possibilities of combining these enzymes have been discussed (use of free enzymes, independently immobilized enzymes or co-immobilized enzymes). Curiously, some studies propose the addition of hydrogen peroxide to this co-immobilized enzyme system to produce oxygen in situ. Other cascade reactions directed toward the production of gluconic acid from polymeric substrates will be presented; these will mainly involve the transformation of polysaccharides (amylases, cellulases, etc.) but will not be limited to those (e.g., gluconolactonase). In fact, glucose oxidase is perhaps one of most successful enzymes, and it is involved in a wide range of cascade reactions. Finally, other applications of the enzyme have been reviewed, always based on the production of D-gluconic acid, which produces a decrease in the pH, a decrease in the oxygen availability or the production of hydrogen peroxide; in many instances, cascade reactions are also utilized. Thus, this review presents many different cascade reactions and discusses the advantages/drawbacks of the use of co-immobilized enzymes.We gratefully recognize the financial support from Ministerio de Ciencia e Innovación-Spanish Government and FEDER funds (project number CTQ2017-86170-R, RTI2018-095291-BI00, MAT2017-87579-R) and Generalitat Valenciana (PROMETEO/2018/076). DC thank to Ministerio de Ciencia e Innovacion-Spanish Government by a FPI. PWT thanks to the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001
Critical assessment of enhancement factor measurements in surface-enhanced raman scattering on different substrates
The SERS enhancement factor (SERS-EF) is one of the most important parameters that characterizes the ability of a given substrate to enhance the Raman signal for SERS applications. The comparison of SERS intensities and SERS-EF values across different substrates is a common practice to unravel the performance of a given substrate. In this study, it is shown that such a comparison may lack significance if we compare substrates of very distinct nature and optical properties. It is specifically shown that the SERS-EF values for static substrates (e.g. immobilized metallic nanostructures) cannot be compared to those of dynamic ones (e.g. colloidal metal nanoparticle solutions), and that the optical properties for the latter show strong dependence on the metal-molecule interaction dynamics. The most representative experimental results concerning the dynamic substrates have been supported by generalized Mie theory simulations, which are tools used to describe the substrate complexity and the microscopic information not usually taken into account17332129421301CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MINAS GERAIS - FAPEMIGFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPES
Emergent geometry from q-deformations of N=4 super Yang-Mills
We study BPS states in a marginal deformation of super Yang-Mills on R x S^3
using a quantum mechanical system of q-commuting matrices. We focus mainly on
the case where the parameter q is a root of unity, so that the AdS dual of the
field theory can be associated to an orbifold of AdS_5x S^5. We show that in
the large N limit, BPS states are described by density distributions of
eigenvalues and we assign to these distributions a geometrical spacetime
interpretation. We go beyond BPS configurations by turning on perturbative
non-q-commuting excitations. Considering states in an appropriate BMN limit, we
use a saddle point approximation to compute the BMN energy to all perturbative
orders in the 't Hooft coupling. We also examine some BMN like states that
correspond to twisted sector string states in the orbifold and we show that our
geometrical interpretation of the system is consistent with the quantum numbers
of the corresponding states under the quantum symmetry of the orbifold.Comment: 22 pages, 1 figure. v2: added references. v3:final published versio
UMA ABORDAGEM MULTIAGENTES PARA SISTEMA DEFENSIVO EM UM TIME DE FUTEBOL DE ROBÔS BÍPEDES
This article describes the defense module developed for an autonomous robot soccer team. Believing artificial intelligence is capable of overcoming limitations of movement such as slow walking, a new behaviour state was created and added to the decision making logic of our agents: a player marker focused on the opponent with current possession of the ball, defensively supporting the ally currently active. This module was developed during the 2014 edition of RoboCup, where it was initially validated and, later on, automatic tests were performed showing an improvement not only on the team's defense, but also in its overall performance. A few variables, such as ball possession, game concentration zone, among others were measured to estimate the impacts of adopting this module.Este artigo descreve o módulo de defesa cooperativa desenvolvido para um time autônomo de futebol de robôs. Acreditando que a inteligência artificial é capaz de superar limitações da movimentação, foi criado um novo estado comportamental para compor a tomada de decisão dos agentes: uma marcação focada no oponente com atual posse da bola, dando suporte de defesa ao jogador aliado em estado ativo. Este módulo foi desenvolvido durante a edição de 2014 da RoboCup, tendo sido inicialmente validado ainda em competição, e posteriormente através de testes automatizados, através dos quais foi possível perceber uma melhora não só na defesa do time, mas também em seu desempenho geral. Uma série de indicadores como posse de bola, zona de concentração de jogo entre outros foram mensurados para aferir os impactos da adoção deste módulo
Engineering shape anisotropy of Fe3O4-¿-Fe2O3 hollow nanoparticles for magnetic hyperthermia
The use of microwave-assisted synthesis (in water) of a-Fe2O3 nanomaterials followed by their transformation onto iron oxide Fe3O4-¿-Fe2O3 hollow nanoparticles encoding well-defined sizes and shapes [nanorings (NRs) and nanotubes (NTs)] is henceforth described. The impact of experimental variables such as concentration of reactants, volume of solvent employed, and reaction times/temperatures during the shape-controlled synthesis revealed that the key factor that gated generation of morphologically diverse nanoparticles was associated to the initial concentration of phosphate anions employed in the reactant mixture. All the nanomaterials presented were fully characterized by powder X-ray diffraction, field emission scanning electron microscopy, Fourier transform infrared, Mössbauer spectroscopy, and superconducting quantum interference device (SQUID). The hollow nanoparticles that expressed the most promising magnetic responses, NTs and NRs, were further tested in terms of efficiencies in controlling the magnetic hyperthermia, in view of their possible use for biomedical applications, supported by their excellent viability as screened by in vitro cytotoxicity tests. These systems NTs and NRs expressed very good magneto-hyperthermia properties, results that were further validated by micromagnetic simulations. The observed specific absorption rate (SAR) and intrinsic loss power of the NRs and NTs peaked the values of 340 W/g and 2.45 nH m2 kg-1 (NRs) and 465 W/g and 3.3 nH m2 kg-1 (NTs), respectively, at the maximum clinical field 450 Oe and under a frequency of 107 kHz and are the highest values among those reported so far in the hollow iron-oxide family. The higher SAR in NTs accounts the importance of magnetic shape anisotropy, which is well-predicted by the modified dynamic hysteresis (ß-MDH) theoretical model
Caracterización de la actividad enzimática del jugo gástrico de pulpo, Octopus vulgaris y de choco, Sepia officinalis a distintos pH. Digestibilidad in vitro de distintas dietas, con jugo gástrico de pulpo
Intensive culture of marine species has been increasing in many countries, such
as Japan, Norway, Spain, France, and Greece. Recent research to improve the quality and
quantity of aquatic animals production by understanding the process of feeding (ingestion,
digestion, and absorption), with emphasis on the digestive enzymatic capabilities is important
in order to understand metabolic processes and reduce costs and time on the development
of such diets. The impetus to increase knowledge about suitable inert diets to partially or
totally replace live feed would reduce this expensive part of the operation, particularly in new
potential species, such as the octopus, Octopus vulgaris, and the cuttlefi sh, Sepia offi cinalis,
which are two of the most promising cephalopods for large-scale culture. This work is
divided into two parts: (1) Enzymatic characterization, by determination of protease activity
of the gastric juice at pH ranges from 2 to 12, since this is the major responsible of digestion
processes, and (2) In vitro evaluation of several prepared diets, as well as a selection of
several natural animal protein sources, by means of a pH-Stat system The results of Part 1 showed that the digestive enzyme activity in total proteases from the gastric juice was higher
at pH 7 and 9, therefore being a more alkaline digestion for these species. Total proteases
activity was higher at pH 8, while the tripsin activity was higher at pH 7, for both species.
For Part 2, the natural diets (natural or liophylized squid, blue whiting and mussel) promoted
the highest digestibility, with the highest value being attained with liophylized squid (49%).
From the prepared diets, based on raw blue whiting paste, those diets agglutinated with
gelatine delivered the highest digestibility. The use of soy protein, as well as heating gelatine
as agglutinants, promoted poor digestibility
- …