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Manejo genético para a conservação ex situ do Mutum-do-Sudeste, Crax blumenbachii (aves, cracidae)
(Universidade Federal de São Carlos, 2015-01-30) Costa, Mariellen Cristine; Francisco, Mercival Roberto; https://lattes.cnpq.br/4305313620456233; https://lattes.cnpq.br/2645130303841091
Captive populations of endangered species are often small, isolated, and founded by a limited number of individuals, which makes them more susceptible to genetic drift and inbreeding effects. Thus, the preservation of the maximum genetic variability is a major concern of captive breeding programs, and understanding the levels of population structuring and genetic variability is important for developing management strategies of captive populations. The Red-billed Curassow (Crax blumenbachii) is endemic to the Brazilian lowland Atlantic Forests and is considered extinct in most of its original distribution. A captive breeding program was initiated during the 70s with the independent foundation of two breeding stocks, that posteriorly supplied animals to other aviaries. With the success of the captive propagation, a reintroduction program has started in 1991, and more than 226 animals have been released into the wild so far. However, animals descending from only one aviary have been used, and the capability of other lineages to increase genetic variability in these, and future released populations, has never been investigated. Then, we analyzed the genetic structure and diversity of the founders and two further important breeding facilities reproducing this species, using 8 microsatellite loci. Bayesian clustering analysis revealed two distinct groups that were in Hardy–Weinberg equilibrium and did not present significant evidences of inbreeding. The existence of two distinct lineages in captivity has implications for breeding and reintroduction programs. We recommend populations to be managed as independent units, but admixted individuals should be produced as a manner to increase reintroduction success.
Scaffolds de óxido de titânio e biosilicato para aplicações médicas e odontológicas obtidos com o uso de partículas orgânicas
(Universidade Federal de São Carlos, 2015-01-30) Fernandes, Mérilin Cristina dos Santos; Paulin Filho, Pedro Íris; https://lattes.cnpq.br/9542027656569433; Morelli, Márcio Raymundo; https://lattes.cnpq.br/0172837599844991; https://lattes.cnpq.br/2740250822457796
Scaffolds are an alternative to natural grafts to help bone regeneration in large bone defects. Regardless of the material chosen for its manufacture, scaffold should have a suitable dimensional microenvironment to promote osteogenesis and an appropriate mechanical stability for the defect site. Titanium dioxide (TiO2) is a highly biocompatible ceramic with good osteoconductive properties and high reliability mechanical; biosilicate has excellent bioactivity level. Thus, in order to fabricate scaffolds allying positive mechanical strength and bioactivity characteristics necessary to a good product, biosilicate was pioneered combined with TiO2. Among the techniques available for scaffolds production, the sacrificial template method, in which porosity is generated by thermal elimination of organic materials added to the ceramic matrix, has a low cost, simplicity and versatility. Different sacrificial agents were tested and the presentation of sawdust as a promising material in scaffolds manufacture proved to be innovative and satisfactory. Microstructural analyzes showed that controlled addition of wood sawdust amounts generated a homogeneous and highly interconnected pore structure with 63% apparent porosity and an average pore size higher than 200 μm. Bioactivity tests in SBF showed that after 4 days of immersion has already observed starting precipitation of hydroxycarbonate apatite in products with biosilicate, and after 12 days of immersion the scaffold was fully covered by this mineral. Mechanical tests allowed evaluating the scaffolds behavior when they are requested by tensile efforts, and revealed for samples with maximum porosity obtained, higher values of strength for samples containing biosilicate. The produced scaffolds had success in the pore structure obtained by sacrificial template method being biosilicato addition guaranteed improvements in bioactivity and mechanical strength.
Estudo das propriedades dos filmes de fosfato de cálcio produzidos pela técnica de sputtering
(Universidade Federal de São Carlos, 2015-01-30) Piraja, Juliana; López, Johnny Vilcarromero; https://lattes.cnpq.br/6059162410604594; Cruz, Térsio Guilherme de Souza; http://lattes.cnpq.br/0705292304279277; Durrant, Steven Frederick; http://lattes.cnpq.br/5137862536106636
The study of calcium phosphate coatings, in particular hydroxyapatite for applications on metal implants, has increased in order to improve the interaction between the tissue and the implant. In this work, calcium phosphate thin films were deposited by rf-sputtering and rf-magnetron sputtering techniques over Si and Ti substrates. For the films deposited by rf-sputtering the target was pressed at 2,5x103 kg and sintered at 600° C for 1 h. For the films deposited by rf-magnetron sputtering the target was pressed in the range of 1,5x103 kg to 3,5x103 kg and sintered in the range of RT (room temperature) to 750° C for 1 h. The chemical structure, composition and morphology of the coatings were evaluated using X-ray diffraction (XRD), infrared transmission (FTIR), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), thickness measurements and bioactivity evaluation over biologic fluid in vitro (SBF) procedures on the sample were made. The purpose of this work was evaluate the influence of the deposition parameters used in the sample prepared by rf-sputtering such as self bias voltage and substrate temperature on the structural properties and physicochemical characteristics of coatings. By the analysis of X-ray diffraction in samples prepared by rf-sputtering and rf-magnetron sputtering it was noted a significant crystallization of coatings resulting from the presence of (002) and (112) peaks and 30 nm grain size. Infra-red spectra results of the samples prepared by rf-sputtering and rf-magnetron sputtering showed one vibration frequency normally observed on hydroxyapatite samples at 1030 cm-1 and 520 cm-1. The presence of this very intense and defined bands indicated that the phosphate bands are well-ordered and similar to the hydroxyapatite s structure. EDS analysis showed that the ratio between the atomic concentration Ca/P of thin films prepared by rf-sputtering decreased with the increase of rf power. On the other hand, a ratio of 1,67 was obtained for coatings prepared by rf-magnetron sputtering. It was also observed that the maximum deposition rate occurred in samples prepared by rf-sputtering at 200°C. SEM analysis revealed the presence of hydroxyapatite grains uniformly distributed in the films prepared by both techniques. These results indicate that the films have potential for biomedical applications.