ABSTRACT The use of resistant cultivars is the main strategy to control Fusarium wilt on tomato, caused by Fusarium oxysporum f. sp. lycopersici . This study aimed to quantify the incidence and distribution of this disease in the region of Nova Friburgo, RJ, as well as the type of resistance of tomato cultivars to the three FOL races. Samples of healthy and wilted plants from 40 properties were evaluated for the presence of vascular discouloration. Seventeen tomato cultivars were evaluated for resistance to the three FOL races using a grading scale. Classification for resistance/susceptibility, incidence and percentage of infection of the vascular system, fresh weight accumulation and seedling length were determined. All the cultivars analysed behaved as similar to immune (SI) to race 1 of FOL and similar to immune or partial resistance to race 2. Only Aguamiel cultivar presented a SI reaction to FOL race 3. None of the cultivars presented a SI reaction to the three races. It can be concluded that failures on the control of the disease in this region can be attributed to the majority use of cultivars with incomplete resistance to the three FOL races. The seed packages also contain incomplete information about FOL resistance.

Abstract Eugenol is a phenolic compound with numerous biological activities. It is widely used in dentistry to treat toothache and pulpitis. In particular, eugenol may be used for tooth whitening procedures to minimize dental sensitivity in patients. However, eugenol has some disadvantages such as its volatility, its photosensitivity, and immediate effect, which can be avoided by using pharmaceutical nanotechnology. The aim of the present study was to obtain, characterize, quantify, and evaluate the physicochemical stability of eugenol-loaded Eudragit RS100 nanocapsules. The nanocapsules (NCs) were prepared by interfacial deposition of the preformed polymer method. The NCs were characterized through morphological and spectroscopic studies. The encapsulation efficiency was achieved by quantifying the non-encapsulated eugenol using a previously developed and validated analytical method. The physicochemical stability of NCs was assessed at predetermined time intervals for 90 days after preparation. The nanocapsules were successfully prepared by the chosen method and had a predominantly spherical shape with a smooth surface. The mean size, the polydispersion index, and the zeta potential were in agreement to literature data. Infrared spectra ensured that the nanoencapsulation process did not result in chemical reactions between the drug and the polymer. The formulations showed encapsulation efficiency higher than 90% and remained stable after 60 days of preparation. Thus, eugenol-loaded Eudragit RS100 nanocapsules may be further considered as an alternative formulation for dental sensitivity in order to provide a controlled release, a decreased toxicity, and a better dental sensitivity relief.

ABSTRACT Turbulent flow is responsible for a significant portion of damages and failures in dams. This paper sought to introduce novel approaches to the estimation of typical parameters used in the design of stilling basins. The standard deviations of pressure samples of 24 hydraulic jumps were analysed throughout the stilling basin longitudinal centreline, and the positions of maximum pressure fluctuation were identified. Next, mean and extreme pressures occurring at this position were calculated. Finally, these parameters were plotted against the inflow Froude number and curves were adjusted to the data. The position where maximum turbulence of undular, weak and oscillating jumps occurs varies according to the Froude number. Steady and strong jumps are more likely to induce negative pressures on the stilling basin. The findings of this paper broaden the knowledge on which regions of the stilling basin must receive special attention, and on how to minimize the chances of damages.

RESUMO O escoamento turbulento é responsável por diversos danos e falhas nas barragens. Neste artigo, introduz-se uma abordagem para estimar parâmetros característicos do dimensionamento de bacias de dissipação. Os desvios padrão das amostras de pressão de 24 ressaltos hidráulicos foram analisados em todo o eixo longitudinal da bacia de dissipação, e as posições de flutuação de pressão máxima foram identificadas. Em seguida, foram calculadas as pressões médias e extremas que ocorrem nesta posição. Finalmente, estes parâmetros foram plotados em relação ao número de Froude incidente e foram ajustadas curvas aos dados. A posição onde ocorre a máxima turbulência de ressaltos ondulados, fracos e oscilantes varia de acordo com o número de Froude. Ressaltos firmes e fortes são mais propensos a gerarem pressões negativas na bacia de dissipação. As conclusões ampliam o conhecimento sobre quais regiões da bacia de dissipação devem receber atenção especial e como minimizar as chances de danos.

ABSTRACT Purpose: To evaluate the long-chain fatty acid and major compounds levels in the feces after prophylactic oral use of Lacticaseibacillus casei in an experimental model of intestinal mucositis. Methods: Fifteen Swiss mice were randomly divided into three groups (n=5/group): The negative or positive control groups (n = 5) received saline orally for 18 days and an the intraperitoneal (i.p.) of saline or 5 Fluorouracil (450 mg/kg) in 15th day, respectability. L. casei group received oral concentration of L. casei (1x109 CFU/mL) for 18 days, the i.p. injection of 5-fluorouracil (450 mg/kg) in 15th days. Tissue samples from colon and each small intestine segment were collected for histopathological analysis. Stool samples were collected. Fecal composition of long-chain fatty acids and sterols were analysed by gas chromatography-mass spectrometry on the 15th and the 18th day. Results: The mucosa layer of all small intestine segments of animals from L. casei showed well preserved epithelium and glands, without necrosis signs, but Goblet cells number decreased. Several long-chain fatty acids and sterols have been identified before and after in the groups. L. casei administration after 5-FU treatment reduced concentrations of linoleic acid (18:2) (p < 0.001) and oleic acid (18:1) (p < 0.001) in feces. Conclusions: L. casei prevented the mucosal damage associated with 5-FU-induced intestinal mucositis reduced long-chain fatty acid levels in the feces.

Resumo Observar e analisar as causas, os efeitos e as múltiplas consequências econômicas, sociais e sanitárias da pandemia da COVID-19 têm sido primordiais não apenas para a compreensão desse fenômeno mundial, mas também para a elaboração de alternativas e soluções que minimizem os impactos na vida das populações ao redor do mundo. Este artigo tem como principal objetivo entender a ascensão da renda básica emergencial como alternativa viável de política pública no cenário brasileiro, por meio do Auxílio Emergencial. Baseado na literatura de agenda-setting, em específico no conceito de eventos focalizadores (focusing events), recuperamos um breve histórico das políticas de transferência de renda e de combate à pobreza e os principais atores envolvidos, para entender mudanças, adaptações e soluções propostas para que a alternativa de renda básica emergencial pudesse ser considerada e aceita neste momento específico de crise.

Abstract Observing and analyzing the causes, effects, and multiple economic, social, and health consequences of the COVID-19 pandemic have been essential to understand this worldwide phenomenon and find solutions that minimize the impacts on peoples’ lives. This article aims to understand the rise of the emergency basic income as a viable policy to tackle the pandemic in Brazil. Based on the agenda-setting literature, specifically on the concept of focusing events, we present a brief history of cash transfer and poverty reduction policies, as well as the actors involved. The study discusses the changes, adaptations, and solutions proposed during the formulation of the emergency basic income as a policy to be considered and effectively adopted in this specific moment of crisis.

Resumen Observar y analizar las causas, efectos y las múltiples consecuencias económicas, sociales y de salud de la pandemia de COVID-19 han sido primordiales no solo para comprender este fenómeno mundial, sino también para el desarrollo de alternativas y soluciones que minimicen los impactos en la vida de poblaciones de todo el mundo. El principal objetivo de este artículo es entender el reconocimiento de la renta básica de emergencia como una alternativa viable de política pública en el escenario brasileño, que ha adoptado un “beneficio de emergencia”. Con base en la literatura de agenda-setting, específicamente en el concepto de eventos focales, recuperamos una reseña de las políticas de transferencia de renta, de reducción de la pobreza y los principales actores involucrados, para comprender los cambios, adaptaciones y soluciones propuestas para que la alternativa de renta básica de emergencia pudiera considerarse y aceptarse en este momento específico de crisis.

Abstract This paper aims to compare militia organizations in two peripheral late medieval kingdoms: Portugal and Sweden. In the Portuguese case, the «besteiros do conto» (crossbowmen) militia is the object of study, whereas in Sweden, the rural «uppbåd» peasant militia is analyzed. In this study, these two objects are compared in terms of origins, organization, leadership, relation to state or royal power, forms of service reimbursement, strategies of recruitment and training, campaign performance, estimated professionalism and impact on martial society. The aim is further to assess on what points we find similar developments, but also how they differ and the possible reasons for it.

Resumo Este artigo procura analisar dois corpos de combatentes armados com besta em dois reinos periféricos: Portugal e Suécia. Por um lado, para o caso português, será usado como objeto de estudo os besteiros do conto. Por outro, serão analisadas milícias de besteiros que assumiram um papel relevante na organização do exército do reino sueco. Nesse sentido, este estudo procurará analisar as origens, a organização, a estrutura de comando, as relações desenvolvidas com o Estado ou os poderes régios, as diferentes formas de pagamento pelo serviço militar, as estratégias de recrutamento e de treino, o desempenho armado em campanhas militares e, por fim, a eventual “profissionalização” de ambas as milícias, assim como o proeminente papel que desempenharam em teatros de operações. Com este estudo comparativo procura-se conhecer eventuais similaridades e possíveis diferenças no desenvolvimento histórico de ambas as milícias, tentando encontrar as respostas para essas problemáticas.

Abstract The war organization performed by the Portuguese Crown and by the Military Orders made themselves dependent on the recruitment of external people (namely from the aristocracy and from the municipal militias). Although the recruitment and the mobilization required to both some complex and joint procedures, we intend to understand if the Military Orders had assumed any independent role in this kind of missions. Thinking on these questions, we aim at contributing both to a deep knowledge of the Military Orders’ armies and to the relevance of their military groups within the royal armies in which they were involved.

Resumo A organização da guerra feita pela Coroa e pelas Ordens Militares em Portugal tornavam-nas dependentes do recrutamento de pessoas externas (aristocracia e milícias municipais). Embora o recrutamento e a mobilização envolvessem processos complexos por parte de ambas, pretendemos apurar se as Ordens Militares tinham alguma independência neste tipo de missões. Refletindo sobre estas questões, pretendemos contribuir tanto para o aprofundamento do conhecimento dos exércitos das Ordens Militares, como para o dos contingentes que estas forneciam para os exércitos régios em que eram incluídas.

ABSTRACT The present study evaluated the genetic variability of the broodstocks of tambaqui hatcheries in the Brazilian state of Pará. Samples were obtained from the caudal fin of 110 broodstocks from one hatchery in each of four municipalities (Santarém, Peixe-Boi, Breu-Branco, and Ulianópolis), representing all the individuals of each hatchery stock. The samples were genotyped using the multiplex system microsatellite markers. Data were used to calculate observed and expected heterozygosity, number of alleles per locus, and allelic richness. The effective population size and inbreeding coefficient were also calculated. The genetic differentiation between populations was evaluated by using FST, and population structuring by the most likely number of genetically homogenous populations and Unweighted Pair Group Method (UPGMA); the arithmetic means were based on Nei's. The indices indicated a loss of genetic variability in the broodstocks from Ulianópolis, Peixe-Boi, and Breu-Branco in comparison with wild tambaqui populations, although this was not apparent in the Santarém stock. A moderate level of genetic differentiation was found among the tambaqui broodstocks based on the FST estimates, which were reinforced by the structuring found in the Bayesian analysis and UPGMA. This reflects the domestication process, given that no such structuring is found in natural tambaqui populations. This moderate genetic differentiation associated with the loss of genetic variability found in the four tambaqui broodstocks from the state of Pará provides important insights for the development of future programs of genetic improvement, as well as the conservation of the genetic diversity of these stocks.

A series of new glycosylated 2-aryl-5-amidinobenzimidazoles derived from four different carbohydrates (D-glucose, D-galactose, N-acetyl-D-glucosamine and lactose) were synthesized by the condensation of the appropriate 4-formyl-3-methoxyphenyl glycoside with 4-amidino- or 4-N-isopropylamidino-ortho-phenylenediamine hydrochloride. All the compounds were properly characterized by high resolution mass spectrometry, uni- and bidimensional 1H and 13C nuclear magnetic resonance and then were evaluated for their antibacterial and antifungal potential. Considering the antifungal potential of them, two derivatives were active against Candida parapsilosis at 96.4 µmol L-1 and another was active against this same strain at 83.5 µmol L-1. In addition, one benzamidine showed activity against Candida glabrata at 97 µmol L-1. Considering the antibacterial potential of these compounds, six of them showed better activity against three different stains: three of them with IC50 of 96.4, 97 and 83.5 μmol L-1 against Gram-positive Micrococcus luteus, the other two with IC50 96.5 and 96.4 μmol L-1 against Gram-positive Enterococcus faecalis and one against Gram-negative Escherichia coli at 90.5 µmol L-1. These findings suggest this structural pattern can be employed for design of more potent agents for discovery of new antimicrobial drug candidates.

OBJECTIVES: The number of pancreatic transplants has decreased in recent years. Pancreatic grafts have been underutilized compared to other solid grafts. One cause of discard is the macroscopic appearance of the pancreas, especially the presence of fatty infiltration. The current research is aimed at understanding any graft-related association between fatty tissue infiltration of the pancreas and liver steatosis. METHODS: From August 2013 to August 2014, a prospective cross-sectional clinical study using data from 54 multiple deceased donor organs was performed. RESULTS: Micro- and macroscopic liver steatosis were significantly correlated with the donor body mass index ([BMI]; p=0.029 and p=0.006, respectively). Positive gamma associations between pancreatic and liver macroscopic and microscopic findings (0.98; confidence interval [CI]: 0.95-1 and 0.52; CI 0.04-1, respectively) were observed. Furthermore, comparisons of liver microscopy findings showed significant differences between severe versus absent (p<0.001), severe versus mild (p<0.001), and severe versus moderate classifications (p<0.001). The area under the receiver operating curve was 0.94 for the diagnosis of steatosis by BMI evaluation using a cut-off BMI of 27.5 kg/m2, which yielded 100% sensitivity, 87% specificity, and 100% negative predictive value. CONCLUSIONS: We observed a positive association of macroscopic and microscopic histopathological findings in steatotic livers with adipose infiltration of pancreatic grafts.

RESUMO CONTEXTO: O período pré-transplante é complexo e inclui grande quantidade de procedimentos. A gravidade da doença hepática predispõe a um alto número de internações e procedimentos de alto custo. Estudos em avaliação econômica são uma importante ferramenta para o manejo dos custos em lista de espera para o transplante hepático. OBJETIVO: O objetivo do presente estudo foi avaliar o custo total do paciente em lista de espera para o transplante hepático e os principais recursos relacionados ao alto custo. MÉTODOS: Foi realizado um estudo de coorte em 482 pacientes registrados em lista de espera para o transplante hepático. Os pacientes foram acompanhados por um período de 24 meses, no qual foram avaliados todos os custos de materiais, medicamentos, consultas, procedimentos internações, exames laboratoriais e de imagem, reposição de hemocomponentes e nutrição recebida. A quantidade total de cada recurso e componente utilizado foi obtida e multiplicada pelo seu valor unitário e, desta maneira, o custo individual de cada paciente foi obtido. RESULTADOS: O total gasto pelos 482 pacientes foi de US$ 6.064.986,51. Os custos ambulatoriais corresponderam a 32,4% do total (US$ 1.965.045,52) e os custos em internação corresponderam a 67,6% do total (US$ 4.099.940,99). Os principais determinantes do custo em ambulatório foram: medicamentos (44,31%) e exames laboratoriais e de imagem (31,68%). Os principais determinantes de custo em internações foram: medicamentos (35,20%), utilização do leito em enfermaria e em UTI (26,38%) e exames laboratoriais (13,72%) Pacientes com valores de MELD entre 25-30 foram os de maiores custos em lista de espera (US$ 16.686,74 ± 16,105.02) e os de menor custo foram os pacientes com MELD abaixo de 17 (US$ 5.703,22 ± 9.318,68). CONCLUSÃO: O custo total em lista de espera para o transplante hepático aumenta de acordo com a gravidade do paciente. Individualmente, internações, reposição de hemocomponentes e o tratamento do paciente com carcinoma hepatocelular são os principais determinantes de custo para os pacientes em lista de espera para o transplante hepático. Quanto maior o tempo de espera, maiores serão os custos em lista, causando maior impacto nos sistemas de saúde.

ABSTRACT BACKGROUND: The pre-transplant period is complex and includes lots of procedures. The severity of liver disease predisposes to a high number of hospitalizations and high costs procedures. Economic evaluation studies are important tools to handle costs on the waiting list for liver transplantation. OBJECTIVE: The objective of the present study was to evaluate the total cost of the patient on the waiting list for liver transplantation and the main resources related to higher costs. METHODS: A cost study in a cohort of 482 patients registered on waiting list for liver transplantation was carried out. In 24 months follow-up, we evaluated all costs of materials, medicines, consultations, procedures, hospital admissions, laboratorial tests and image exams, hemocomponents replacements, and nutrition. The total amount of each resource or component used was aggregated and multiplied by the unitary cost, and thus individual cost for each patient was obtained. RESULTS: The total expenditure of the 482 patients was US$ 6,064,986.51. Outpatient and impatient costs correspond to 32.4% of total cost (US$ 1,965,045.52) and 67.6% (US$ 4,099,940.99) respectively. Main cost drivers in outpatient were: medicines (44.31%), laboratorial tests and image exams (31.68%). Main cost drivers regarding hospitalizations were: medicines (35.20%), bed use in ward and ICU (26.38%) and laboratorial tests (13.72%). Patients with MELD score between 25-30 were the most expensive on the waiting list (US$ 16,686.74 ± 16,105.02) and the less expensive were those with MELD below 17 (US$ 5,703.22 ± 9,318.68). CONCLUSION: Total costs on the waiting list for liver transplantation increased according to the patient’s severity. Individually, hospitalizations, hemocomponents reposition and hepatocellular carcinoma treatment were the main cost drivers to the patient on the waiting list. The longer the waiting time, the higher the total cost on list, causing greater impact on health systems.

ABSTRACT This study aimed to compare the richness and composition of the epiphytic bryoflora between várzea and igapó forests in Caxiuanã National Forest, Brazilian Amazon. Bryophytes were collected on 502 phorophytes of Virola surinamensis. Average richness per phorophyte and composition between forests and between dry and rainy periods was tested by two-way analysis and by cluster analysis, respectively. In total, 54 species of 13 families were identified. Richness was greater in igapó forest (44 species) compared to várzea forest (38 species). There was no significant difference in the number of species between the studied periods. Cluster analysis showed the bryoflora composition was different between várzea and igapó, but not between dry and rainy periods. Results did not corroborate the hypothesis that várzea forests harbor higher species richness than igapó forests.

Este trabalho teve como objetivo conhecer a biologia reprodutiva da brioflora epífita de forófitos de Virola surinamensis (Rol. ex. Rottb.) Warb. na várzea e igapó na Floresta Nacional de Caxiuanã, para responder à seguinte pergunta: O período de reprodução das espé cies de briófitas é influenciado pelo ambiente devido a sazonalidade climática presente em florestas inundadas, sendo maior a ocorrência da reprodução sexuada e assexuada nos meses mais chuvosos? As briófitas foram identificadas e analisadas quanto ao tipo de reprodução, sistema sexual e estruturas reprodutivas. No total, foram analisadas 502 amostras de briófitas, resultando em 54 espécies, das quais 34 eram férteis. A comparação da fertilidade das espécies em diferentes condições ambientais (seca ou chuva e igapó ou várzea) foi avaliada pelo teste do qui-quadrado. A fertilidade das sete espécies testadas não pode ser definida por um padrão, com relação aos tipos de florestas e aos períodos. Entretanto, duas espécies foram associadas ao período com chuvas e outras duas espécies ao tipo de floresta, o que revela que, para algumas espécies de briófitas, investir na fertilidade constante pode estar favorecendo a manutenção das suas populações em florestas tropicais.

This work aimed to recognize the reproductive biology of the epiphytic bryoflora of phorophytes of Virola surinamensis (Rol. ex. Rottb.) Warb. in várzea and igapó forests in the Caxiuanã National Forest, to answer the following question: The reproductive period of the bryophyte species is influenced by the environment due the climatic seasonality present in flooded forests, being higher the occurrence of the sexual and asexual reproduction in the rainiest months? The bryophytes were identified and analyzed for the type of reproduction, sexual system and reproductive structures. In total, 502 samples of bryophytes were analyzed, resulting in 54 species, of which 34 were fertile. The comparison of the fertility of the species in different environmental conditions (dry or rainy, and igapó or várzea forest) was assessed using the chi-square test. The fertility of the seven studied species could not be defined by a pattern, considering the forest type and the seasonality. However, two species were associated to the forest type and two further species to the seasonality, showing that, for some bryophyte species, invest in constant fertility may be favoring the maintenance of their populations in tropical forests.

Resumo Objetivou-se propor a tabela normativa para a população brasileira de mulheres não ativas na pós-menopausa entre 50 e 69 anos por meio da bateria de teste de aptidão funcional da AAHPERD. Estudo de característica transversal, com 170 mulheres na pós-menopausa (dosagem de FSH>26,72 mIU/L). A população foi dividida em dois grupos: 50 a 59 anos (n=97) e de 60 a 69 anos (n=73). Os critérios de inclusão foram não participar de intervenção motora sistematizada nos seis meses anteriores ao período do estudo; não apresentar comprometimentos motores ou cognitivos que inviabilizassem a realização dos protocolos de avaliação, não apresentar comorbidade que pudessem impedir ou limitar a realização das avaliações. O grupo 50 a 59 anos apresentou valores médios de 55,6 ± 2,9 anos de idade, 54,0 ± 21,1 mUI/ ml para FSH, 11,3 ± 1,8 segundos para coordenação, 20,2 ± 4,0 repetições para força, 51,9 ± 11,8 centímetros para flexibilidade, 23,0 ± 2,4 segundos para agilidade e 497 ± 39 segundos para resistência aeróbia. O grupo de 60 a 69 anos apresentou média de 64,2 ± 2,8 anos de idade, 54,9 ± 16,1 mUI/ml para o FSH, 11,5 ± 2,5 segundos para coordenação, 20,2 ± 4,3 repetições para força, 54,4 ± 10,9 centímetros para flexibilidade, 24,5 ± 4,0 segundos para agilidade e 507 ± 47 segundos para resistência aeróbia. A proposta de apresentar uma tabela normativa foi possível com os dados analisados, sendo essa uma nova referência em relação a estudos de aptidão funcional especialmente em mulheres fisicamente inativas na pós-menopausa.

Abstract The aim of this study was to propose the normative table for the non-active postmenopausal Brazilian population composed of women aged 50-69 years through the AAHPERD functional fitness test battery. This is a cross-sectional study with 170 postmenopausal women (FSH dose> 26.72 mIU / L). The population was divided into two groups: 50-59 years (n = 97) and 60-69 years (n = 73). The inclusion criteria were not having participated of systematic motor intervention in the six months prior to the study period; not presenting motor or cognitive impairments that could impair the performance of evaluation protocols and absence of comorbidities that could prevent or limit evaluations. The group aged 50-59 years showed mean values of 55.6 ± 2.9 years for age, 54.0 ± 21.1 mIU / ml for FSH, 11.3 ± 1.8 seconds for coordination 20.2 ± 4.0 repetitions for strength, 51.9 ± 11.8 cm for flexibility, 23.0 ± 2.4 seconds for speed and 497 ± 39 seconds for aerobic resistance. The group aged 60-69 years showed mean values of 64.2 ± 2.8 years of age, 54.9 ± 16.1 mIU / ml for FSH, 11.5 ± 2.5 seconds for coordination, 20.2 ± 4.3 repetitions for strength, 54.4 ± 10.9 cm for flexibility, 24.5 ± 4.0 seconds for speed and 507 ± 47 seconds for aerobic resistance. The proposal of a normative table was made possible with the data analyzed, which is a new reference regarding functional fitness studies especially in physically inactive postmenopausal women.

RESUMO A introdução de espécies exóticas é considerada uma das principais causas da perda de biodiversidade. A Floresta Nacional de Carajás é uma das maiores províncias minerais do mundo. As atividades da mineração provocaram alterações dos habitats naturais, deixando áreas degradadas após a exploração mineral. Uma das áreas de mineração dentro da FLONA de Carajás foi usada para a extração de ouro. No processo de exploração, uma enorme cava foi formada pela remoção do solo que foi colocado em montes nas proximidades. Para evitar a erosão do solo desses montes, uma gramínea exótica, Urochloa decumbens (Stapf) R.D.Webster (Poaceae) foi plantada. O objetivo deste estudo foi comparar o impacto desta gramínea não-nativa na riqueza de espécies e composição de espécies da regeneração natural nas áreas degradadas. Quatro áreas foram comparadas, duas com e duas sem a presença de U. decumbens. Em cada área, vinte e quatro parcelas de 1m² foram estabelecidas. A riqueza de espécies e os tamanhos das populações da regeneração natural foram significativamente menores nas parcelas onde a gramínea exótica estava presente. Nosso estudo mostra que U. decumbens tem um efeito negativo sobre a riqueza de espécies e densidade populacional e sua presença alterou a composição e distribuição de formas de vida da regeneração natural das espécies.

ABSTRACT The introduction of exotic species is considered as one of the major causes of biodiversity loss. The National Forest of Carajás is one of the largest mineral provinces in the world. Mining activities caused changes of the natural habitats, leaving degraded areas after the mineral exploitation. One of the mining areas within FLONA Carajás was used for the extraction of gold. In the process of exploitation, a huge depression was formed by the removal of soil which was mounded up nearby. To prevent soil erosion of these mounds, an exotic grass, Urochloa decumbens (Stapf) R.D.Webster (Poaceae) was planted. The objective of this study was to compare the impact of this non-native grass on species richness and species composition of the natural regeneration in the degraded areas. Four areas were compared, two with and two without presence of U. decumbens. In each area, twenty four 1m²/plots were established. Species richness of the regeneration areas and population sizes were significantly lower in the plots where the exotic grass was present. Our study shows that U. decumbens had a negative effect on species richness and population density, and its presence changed the species composition and distribution of life forms of the natural regeneration.