Meson decay in a corrected 30P3^P_0 model

Extensively applied to both light and heavy meson decay and standing as one of the most successful strong decay models is the $3^P_0$ model, in which $q\bar{q}$ pair production is the dominant mechanism. The pair production can be obtained from the non-relativistic limit of a microscopic interaction Hamiltonian involving Dirac quark fields. The evaluation of the decay amplitude can be performed by a diagrammatic technique for drawing quark lines. In this paper we use an alternative approach which consists in a mapping technique, the Fock-Tani formalism, in order to obtain an effective Hamiltonian starting from same microscopic interaction. An additional effect is manifest in this formalism associated to the extended nature of mesons: bound-state corrections. A corrected $3^P_0$ is obtained and applied, as an example, to $b_{1}\to\omega\pi$ and $a_{1}\to\rho\pi$ decays.Comment: 3 figures. To appear in Physical Review

Salinity Induced Changes in the Leaf Anatomy of the Mangrove Avicennia Marina Along the Anthropogenically Stressed Tropical Creek

The mangrove Avicennia marina is a dominant mangrove along the anthropogenically stressed tropical Thane creek, west coast of India. Leaf anatomy of the mangrove along the Thane creek, was assessed in relation to stationwise and seasonwise variations in salinity. It was noticed that under the conditions of higher salinity, Avicennia marina showed increased thickness of hypodermal water storage tissue in the leaf (for conservation of water) and produced taller salt extruding glands at the lower epidermis to eliminate more salt; whereas, the thickness of the photosynthetic mesophyllic tissue significantly reduced. At lower salinity or with reduction in salinity in monsoon, contrary to above occurred. These changes probably explain the stunted growth of Avicennia marina in high salinity environment and its vigorous growth at lower salinity

Desinfestação de erva-mate in vitro.

EVINCI. Resumo 016

Nano-hydroxyapatite in oral care cosmetics: characterization and cytotoxicity assessment

Nano-hydroxyapatite has been used as an oral care ingredient, being incorporated in several products for the treatment of dental hypersensitivity and enamel remineralisation. Despite its promising results, regulatory and safety concerns have been discussed and questioned by the European Scientific Committee on Consumer Safety (SCCS) regarding the usage of hydroxyapatite nanoparticles in oral care products. In this work, a commercially available nano-hydroxyapatite was characterized and its cytocompatibility towards human gingival fibroblasts was evaluated, as well as its irritation potential using the in vitro HET-CAM assay. All the conditions chosen in this study tried to simulate the tooth brushing procedure and the hydroxyapatite nanoparticles levels normally incorporated in oral care products. The commercial hydroxyapatite nanoparticles used in this study exhibited a rod-like morphology and the expected chemical and phase composition. The set of in vitro cytotoxicity parameters accessed showed that these nanoparticles are highly cytocompatible towards human gingival fibroblasts. Additionally, these nanoparticles did not possess any irritation potential on HET-CAM assay. This study clarifies the issues raised by SCCS and it concludes that this specific nano-hydroxyapatite is cytocompatible, as these nanoparticles did not alter the normal behaviour of the cells. Therefore, they are safe to be used in oral care products.The authors acknowledge the support of the Biointerfaces and Nanotechnology i3S Scientific Platform, as well as Luís Teixeira and Marta Ferro from University of Aveiro for the characterization of the HA-NP with TEM. Financial support from the European Union (FEDER funds POCI/01/0145/FEDER/007265) and National Funds (FCT/MEC, Fundação para a Ciência e Tecnologia and Ministério da Educação e Ciência) under the Partnership Agreement PT2020 UID/QUI/50006/2019 is acknowledged

Gosto de barro em tambaquis: problemas e recomendações.

bitstream/item/211442/1/gosto-barro-tambaqui.pd

Comparing Experiences of Constitutional Reforms to Enshrine the Right to Water in Brazil, Colombia, and Peru: Opportunities and Limitations

In this paper we compare recent efforts towards the constitutionalization of the right to water in Brazil, Colombia, and Peru to understand the opportunities and limitations related to the attempts to enhance access to piped water to the highest normative level. Peru passed a constitutional amendment in 2017 while Brazil and Colombia have seen much right-to-water activism but have not succeeded in passing such reforms. We explore the role of the existing domestic legal frameworks on drinkable water provision and water management towards the approval of constitutional amendments. We find that all three countries have specialized laws, water governing institutions, and constitutional jurisprudence connecting access to water with rights, but the legal opportunity structures to enforce socio-economic rights vary; they are stronger in Colombia and Brazil, and weaker in Peru. We argue that legal opportunity structures build legal environments that influence constitutional reform success. Legal opportunity structures act as incentives both for social movements to push for reforms and for actors with legislative power to accept or reject them. Our findings also show that in some contexts political cost is a key element of constitutional reforms that enshrine the right to water; therefore, this is an element that should be considered when analyzing these processes.publishedVersio