Classificação de fibrados principais

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Florianópolis, 1980

Genetic diversity and population structure of Vriesea reitzii (Bromeliaceae), a species from the Southern Brazilian Highlands

The Southern Brazilian Highlands are composed by a mosaic of Mixed Ombrophilous Forest (MOF) and grassland formations, an interesting landscape for the study of population structure. We analyzed the genetic diversity within and among populations of the MOF-endemic bromeliad Vriesea reitzii by genotyping seven nuclear microsatellite loci in 187 individuals from six populations. We characterized levels of genetic diversity and assessed the genetic structure among populations. Vriesea reitzii populations showed high levels of genetic variation (number of alleles 28 - 43, allelic richness 3.589 - 5.531) and moderate levels of genetic differentiation (FST = 0.123, RST = 0.096). The high levels of genetic diversity may be explained by species life-history traits, such as habit and mating system. The moderate structure may be a product of the combination of ancient and contemporary gene flow, resulting from the expansion of the forest in the Holocene, and/or due to facilitated dispersal mediated by the MOF’s mosaic landscape. The genetic results indicated no imminent threat to this bromeliad. However, the species is highly associated with the MOF, putting landscape conservation at the center of conservation efforts for the species’ maintenance

Tradeoffs in the externalities of pig production are not inevitable

Farming externalities are believed to co-vary negatively, yet trade-offs have rarely been quantified systematically. Here we present data from UK and Brazilian pig production systems representative of most commercial systems across the world ranging from ‘intensive’ indoor systems through to extensive free range, Organic and woodland systems to explore co-variation among four major externality costs. We found that no specific farming type was consistently associated with good performance across all domains. Generally, systems with low land use have low greenhouse gas emissions but high antimicrobial use and poor animal welfare, and vice versa. Some individual systems performed well in all domains but were not exclusive to any particular type of farming system. Our findings suggest that trade-offs may be avoidable if mitigation focuses on lowering impacts within system types rather than simply changing types of farming

FATORES CRÍTICOS DE SUCESSO DE PROGRAMAS DE EDUCAÇÃO A DISTÂNCIA VIA INTERNET

Empresas e instituições de ensino têm realizado investimentos significativos na implementação de programas de Educação a Distância (EAD), que utilizam a internet como principal tecnologia de informação e comunicação. O atual cenário econômico, cultural e tecnológico favorece a criação de um mercado eletrônico de aprendizagem, justificando tais investidas. A Educação a Distância aparenta mover-se em direção à internet, mas o caminho é difícil,por causa das muitas incertezas. Estas incertezas, com o grande número de variáveis envolvidas nos programas EAD via internet, dificultam para gestores que se mantenha o foco nos pontos essenciais. Assim, o objetivo deste trabalho é identificar os fatores críticos de sucesso dos programas de educação a distância via internet. Para isso foi realizado um questionário de perguntas com estudantes da UNIASSELVI (Polo de Porto Alegre), que responderam questões sobre o AVA (Ambiente Virtual de Aprendizagem), sobre a qualidade da informação, usabilidade, interatividade, velocidade, arquitetura da informação, confiabilidadee segurança. A partir destes resultados, teremos uma conclusão sobre a influência deste método de estudo e sua contribuição humana. Assim é mais seguro afirmar que, sem prestar atenção aos sete fatores críticos identificados, a probabilidade de que aconteçam problemas com um programa de educação a distância é alta

Investigation of the occurrence of pesticide residues in rural wells and surface water following application to tobacco

In this work the exposure of wells and surface water to pesticides, commonly used for tobacco cropping, was assessed. Water consumption wells and surface water flows were sampled at different times. After a preconcentration step with solid phase extraction (SPE), the selected pesticides were determined by gas chromatography with electron capture detection (GC-ECD) or high performance liquid chromatography with diode array detection (HPLC-DAD). No pesticides were detected in the well water samples and surface water flow in the winter season. However, in the spring and summer higher concentrations of chlorpyrifos and imidacloprid were found in the water source samples. Atrazine, simazine and clomazone were also found. The occurrence of pesticides in collected water samples was related with the application to tobacco

Development, characterization, and transferability of SSR markers for Vriesea carinata (Bromeliaceae) based on RNA sequencing

Premise of the Study: Expressed sequence tag–simple sequence repeat (EST-SSR) markers were isolated for Vriesea carinata, an endemic bromeliad from the Brazilian Atlantic Forest. These SSR loci may be used to investigate the genetic diversity and population structure of this species and related bromeliads. Methods and Results: Based on the transcriptome data of V. carinata, 30 primer pairs were designed and selected for initial validation. Of these primer pairs, 16 generated suitable SSR loci in 69 individuals. The number of alleles per locus ranged from one to 13; the levels of observed and expected heterozygosity per locus ranged from 0.000 to 1.000 and from 0.000 to 0.935, respectively. All loci produced heterologous amplification. Transferability of the loci was tested in 15 species belonging to three Bromeliaceae subfamilies. Conclusions: The developed EST-SSR markers revealed polymorphism in the four studied populations and could be useful to investigate the genetic diversity of V. carinata and related species. The markers may also be suitable for novel gene annotation and discovery

A gas chromatographic method for the determination of the fungicide chlorothalonil in tomatoes and cucumbers and its application to dissipation studies in experimental greenhouses

A new method to evaluate the levels of residue and the dissipation of chlorothalonil fungicide in tomatoes and cucumbers grown in experimental greenhouses was developed and validated. The vegetables were submitted to a single spraying with chlorothalonil at half, equal to and double of the recommended dose. Chlorothalonil residues were extracted in Ultra-Turrax system using ethyl acetate in the presence of anhydrous sodium sulphate and determined by gas chromatography with electron capture detection. The analytical curves were linear from 0.005 to 5.0 mg L-1, with coefficient of determination higher then 0.995. The assays provide acceptable results with RSD values below 10.5% and recoveries were between 92.2 and 114.5% for tomatoes, and between 86.2 and 103.3% for cucumbers, both obtained from spiked samples at 0.028, 0.28, 2.8 and 5.0 mg kg-1 levels. Statistical interpretation of residue levels fitted to a first-order model for the dissipation behavior of chlorothalonil. The mean half-life after treatments at the recommended dose, in the two experimental years, was 8.8 days for tomatoes and 1.6 days for cucumbers. The higher decrease rate of chlorothalonil residues in cucumbers is mainly due to the higher growth rate of this vegetable relative to tomato. The developed method has proven to be efficient for the determination of chlorothalonil residues in tomatoes and cucumbers with a limit of quantification of 0.02 mg kg-1 level, permitting to evaluate the risk of consumer exposure to these residues

Neoadjuvant multikinase inhibitor in patients with locally advanced unresectable thyroid carcinoma

Background: Papillary thyroid carcinoma (PTC) is the most common and less aggressive thyroid cancer, but some patients may display locally advanced disease. Therapeutic options are limited in these cases, particularly for those patients with unresectable tumors. Neoadjuvant therapy is not part of the recommended work up. Methods: Report a case of an unresectable grossly locally invasive PTC successfully managed with neoadjuvant therapy and provide a systematic review (SR) using the terms “Neoadjuvant therapy” AND “Thyroid carcinoma.” Results: A 32-year-old man with a 7.8 cm (in the largest dimension) PTC was referred to total thyroidectomy, but tumor resection was not feasible due to extensive local invasion (trachea, esophagus, and adjacent structures). Sorafenib, a multikinase inhibitor (MKI), was initiated; a 70% tumor reduction was observed after 6 months, allowing new surgical intervention and complete resection. Radioactive iodine (RAI) was administered as adjuvant therapy, and whole body scan (WBS) shows uptake on thyroid bed. One-year post-surgery the patient is asymptomatic with a status of disease defined as an incomplete biochemical response. The SR retrieved 123 studies on neoadjuvant therapy use in thyroid carcinoma; of them, 6 were extracted: 4 case reports and 2 observational studies. MKIs were used as neoadjuvant therapy in three clinical cases with 70–84% of tumor reduction allowing surgery. Conclusion: Our findings, along with other reports, suggest that MKIs is an effective neoadjuvant therapy and should be considered as a therapeutic strategy for unresectable grossly locally invasive thyroid carcinomas