The relationship between the effective tax rate and the nominal rate

The main goal of this investigation is to understand the relationship between the nominal rate and the effective tax rate and to evaluate if the differences between them depend on the value of the nominal rate. Based on a sample of 1,530 companies from 5 countries members of the European Union (Denmark, Slovenia, Finland, Luxembourg and the United Kingdom) there’s evidence that the effective tax rate is positively related to the nominal rate. The effective tax rate was calculated through the ratio between the value of the tax paid over the result before tax. When the nominal tax rate increases, the effective rate increases equally but with a slower growth. This relationship is softened if we take into account the value of the nominal tax rate, which shows that companies have the ability to manage the results in order to increase savings in tax.info:eu-repo/semantics/publishedVersio

Efeito do fogo nas propriedades químicas do solo em um fragmento de floresta nativa e plantio de cupuaçu em porto Velho, Rondônia.

O objetivo desse trabalho foi avaliar as alterações químicas do solo em uma área de floresta nativa, e uma de plantio de cupuaçu com idade de 20 anos, após um incêndio, ocorrido no Campo Experimental da Embrapa, no município de Porto Velho - RO

Avaliação das características do solo em uma recuperação de mata ciliar no município de ouro preto d'oeste, Rondônia.

Este trabalho foi realizado na bacia do rio Boa vista, localizada no município de Ouro Preto d´Oeste - Rondônia, com o intuito de avaliar os componentes químicos e resistência à penetração do solo submetido à recuperação da mata ciliar três anos após o plantio comparando com uma área ao lado de plantio convencional

Starch-based microparticles as carriers for the delivery of platelet-derived growth factor aimed to stimulate the proliferation of osteoblastic-like cells

We have previously shown that starch-based microparticles are bioactive [1], serve as substrates for the culture of osteoblast-like cells [2], and are suitable for controlled release applications [3]. In this way, we postulate that if we combine these different properties we could generate hybrid constructs with enhanced properties. Hence, we describe herein the encapsulation and release of Platelet-Derived Growth Factor (PDGF), as well as its mitogenic effect over osteoblast-like cells. PDGF was encapsulated into starch-based microparticles composed of a blend of 50:50 (wt/wt) starch with polylactic acid (SPLA). The loaded microparticles were tested for released PDGF up to 8 weeks and the released PDGF was quantified using ELISA specific for this growth factor. Bioactivity of released PDGF was assessed using a mouse calvaria cell line (MC3T3-E1) possessing a pre-osteoblastic phenotype. PDGF could be effectively encapsulated into SPLA microparticles. The release profile of PDGF shows there is a burst release in the first hours, and then a reduction in the released levels, with a steady release after 7 days. The release was quantified up to 8 weeks, with reduced, steady-level amounts being released. This release profile is typical for hydrophilic, biodegradable polymers, where the water uptake controls the first release stages, where the encapsulated agent is released by diffusion. In this particular application this behavior is desirable, since PDGF mitogenic effect over osteoblasts is only observed with an intermittent, higher-level supplementation, followed by a low-level, continuous one. The released PDGF bioactivity, evaluated by the response of MC3T3-E1 cells to culture medium supplemented with a defined dosage of either exogenous or released PDGF, reveals that PDGF encapsulated and released from SPLA microparticles is capable of stimulating the proliferation of MC3T3-E1 cells in levels comparable to those of exogenous PDGF. Both conditions significantly enhance the proliferation of osteoblastic cells, as compared to control conditions. In conclusion, we clearly demonstrate the potential of starch-based microparticles to be used as carriers for growth factors. These systems encapsulate, release and maintain the bioactivity of the entrapped growth factor. PDGF was effectively released in a defined profile compatible with the final goal of stimulating the proliferation of cells within a hybrid construct aimed to be used in tissue engineering applications.FCT (SFRH/BD/2001/4698) and European Union funded STREP Project Hippocrates (NNM-3-CT-2003-505758)

The effect of starch and starch-bioactive glass composite microparticles on the adhesion and expression of the osteoblastic phenotype of a bone cell line

There is a clear need for the development of microparticles that can be used simultaneously as carriers of stem/progenitor cells and as release systems for bioactive agents, such as growth factors or differentiation agents. In addition, when thinking on bone-tissueengineering applications, it would be very useful if these microparticles are biodegradable and could be made to be bioactive. Microparticles with all those characteristics could be cultured together with adherent cells in appropriate bioreactors to form in vitro constructs that can then be used in tissue-engineering therapies. In this work, we have characterized the response of MC3T3-E1 pre-osteoblast cells to starch-based microparticles. We evaluated the adhesion, proliferation, expression of osteoblastic markers and mineralization of cells cultured at their surface. The results clearly show that MC3T3-E1 pre-osteoblast cells adhere to the surface of both polymeric and composite starch-based microparticles and express the typical osteoblastic marker genes. Furthermore, the cells were found to mineralize the extracellular matrix (ECM) during the culture period. The obtained results indicate that starch-based microparticles, known already to be biodegradable, bioactive and able to be used as carriers for controlled release applications, can simultaneously be used as carriers for cells. Consequently, they can be used as templates for forming hybrid constructs aiming to be applied in bone-tissue-engineering applications

Starch-based microparticles as vehicles for the delivery of active platelet-derived growth factor

In a previous work, we described the use of starch-based microparticles as vehicles for the controlled release of corticosteroids. The goal of the present work is to evaluate the potential of these microparticles to incorporate and release platelet-derived growth factor (PDGF). The loading efficiency and release profile were evaluated, and PDGF was incorporated into and released from the matrix of starch-based microparticles. The release profile shows rapid release of PDGF in the first 24 h, after which there was a slow but constant release for up to 8 weeks. The maintenance of the PDGF biological activity after incorporation and release was evaluated by itsmitogenic effect over osteoblastic cells, and it was shown to be comparable to that of PDGF supplemented to the culture medium. This proves that the incorporation and release did not affect the biological activity of the growth factor (GF). The results clearly demonstrate that starchbased microparticles are suitable vehicles for the incorporation and release of GFs. When combined with previous results, these materials also suggest their ability to enhance the regenerating potential of tissue engineering hybrid constructs

Progresso genético para produtividade e peso de 100 grãos em 14 anos do Programa de Melhoramento de Arroz Irrigado de Minas Gerais.

O objetivo deste estudo foi estimar o progresso genético e ambiental da produtividade e peso de 100 grãos do programa de melhoramento de arroz irrigado do estado de Minas Gerais no período de 1998 a 2012

Antibody-Antigen Binding Interface Analysis in the Big Data Era

Antibodies have become the Swiss Army tool for molecular biology and nanotechnology. Their outstanding ability to specifically recognise molecular antigens allows their use in many different applications from medicine to the industry. Moreover, the improvement of conventional structural biology techniques (e.g., X-ray, NMR) as well as the emergence of new ones (e.g., Cryo-EM), have permitted in the last years a notable increase of resolved antibody-antigen structures. This offers a unique opportunity to perform an exhaustive structural analysis of antibody-antigen interfaces by employing the large amount of data available nowadays. To leverage this factor, different geometric as well as chemical descriptors were evaluated to perform a comprehensive characterization