ABSTRACT The application of flumioxazin and imazethapyr can affect the interactions between rhizobia and soybean in the rhizosphere. However, it remains unclear the effect of both herbicides, even when applied in mixture, on early nodulation and biological N fixation (BNF) in soybean, mainly related to some important biochemical traits in nodules. This study assessed the effect of flumioxazin, imazethapyr and their mixture on early nodulation and BNF in rhizosphere of soybean. The plant emergence, early nodulation, growth, and N accumulation were evaluated in soybean grown in sandy and clayey soils. The leghemoglobin content and glutamine synthetase (GS) activity were also assessed in fresh nodules. Individually, flumioxazin and imazethapyr did not affect the plant emergence, nodulation and N accumulation in soybean, while the mixture decreased significantly these parameters. Also, the values of leghemoglobin content and GS activity did not decrease with the application of the herbicides individually. The application of herbicides imazethapyr and flumioxazin separately negatively influenced the growth of soybean, while they do not influence the nodulation and N accumulation. However, the use of these herbicides in mixture can negatively influence the early nodulation and N fixation by native rhizobia.

Abstract The assessment of ecosystem functions in Cerrado is important to implement practices of conservation. Recently, a ‘rapid ecosystem function assessment’ (REFA) for measuring ecosystem functions has been proposed and tested as a suitable method. Thus, this study aimed to assess the proxies of ecosystem functions of three physiognomies of Cerrado through REFA. This method was applied in three different preserved physiognomies of Cerrado from Northeastern, Brazil, namely: Campo Graminoide (CG), Cerrado Stricto Sensu (CSS), and Cerradão (CD). All proxies for the selected ecosystem functions differed between sites and seasons. The above- and belowground primary productivity and microbial biomass C were higher in CD than in CSS and CG. The above- and belowground secondary productivity and decomposition were higher and similar in CD and CSS as compared to CG. The principal component analysis explained 89.8% of the data variation and clustered the majority of ecosystem functions with CD, in both seasons and CSS in the wet season. The proxies of ecosystem functions measured through REFA showed differences between the physiognomies of Cerrado. Since each physiognomy of Cerrado presents different plant richness and diversity, and soil conditions, these characteristics contribute to influencing multiple ecosystem functions.

Lima bean (Phaseolus lunatus) is an important species of the genus Phaseolus for human consumption in tropical regions. The seeds are important source of protein for people from South America, Africa and Mexico. In addition, as a legume plant, lima bean presents the ability to perform the biological nitrogen fixation (BNF) through the symbiosis with nitrogen-fixing bacteria. The studies about diversity and efficiency of lima bean-rhizobia symbiosis have increased worldwide, mainly in Latin America. These studies have shown Bradyrhizobium and Rhizobium as the main symbionts, although Sinorhizobium, Mesorhizobium and Allorhizobium have been found associated with lima bean. Also, there is a large variation in the efficiency of N fixation by the current isolates of rhizobia and some rhizobia have presented high capability for fixing N. This review aims to explore the studies about diversity and efficiency of rhizobia in symbiosis with lima bean.

El frijol de lima (Phaseolus lunatus) es una especie importante del género Phaseolus para consumo humano en regiones tropicales. Las semillas son una fuente importante de proteínas para las personas de América del Sur, África y México. Además, como leguminosas, el frijol de lima presenta la capacidad de realizar la fijación biológica de nitrógeno (BNF) a través de la simbiosis con bacterias fijadoras de nitrógeno. Los estudios sobre la diversidad y la eficiencia de la simbiosis de frijol de lima-rizobio han aumentado en todo el mundo, principalmente en América Latina. Estos estudios han demostrado que Bradyrhizobium y Rhizobium son los principales simbiontes, aunque Sinorhizobium, Mesorhizobium y Allorhizobium se han asociado al frijol de lima. Además, existe una gran variación en la eficacia de la fijación de N por los aislamientos actuales de rizobios y algunos rizobios han presentado una alta capacidad para reparar N. Esta revisión tiene como objetivo explorar los estudios sobre la diversidad y la eficacia de rizobios en simbiosis con frijol lima.

RESUMO: Este estudo avaliou a resposta do feijão-fava (Phaseolus lunatus L.) a aplicação de lodo de curtume compostado na nodulação, absorção de N e crescimento. Durante oito anos, o composto foi aplicado em doses de: 0, 2.5, 5, 10, e 20 Mg ha-1 (base seca). As plantas de feijão-fava mostraram maior nodulação nos tratamentos com o composto. Entretanto, os nódulos encontrados nestes tratamentos apresentaram menor biomassa, tamanho e diversidade do que os observados no tratamento sem composto. A acumulação de N aumentou com a aplicação da maior dose do composto (20 Mg ha-1), enquanto que houve um aumento nos teores de crômio na parte aérea com o aumento das doses do composto. Desta forma, o uso do lodo de curtume compostado, em longo prazo, aumenta a acumulação de crômio, aumentando a nodulação, enquanto diminui a diversidade de rizóbios nos nódulos.

ABSTRACT: This study evaluated the responses of lima bean (Phaseolus lunatus L.) to application of composted tannery sludge on nodulation, N uptake and plant growth. For eight years, the compost was applied at rates of: 0, 2.5, 5, 10, and 20 Mg ha-1 (dry basis). Plants of lima bean showed higher nodulation in treatments with compost; however, nodules reported in these treatments presented lower biomass, size and diversity than those reported in treatment without compost. Accumulation of N increased with the application of the highest rate (20 Mg ha-1), while there was an increase in chromium content in shoot with the increase in compost rates. Thus, the use of composted tannery sludge, in long-term, increases the accumulation of chromium in plants, increasing nodulation, while decrease rhizobia diversity in nodules.

Abstract: Different physiognomies across the Cerrado could influence the microbial C:N:P ratio in the soil since these physiognomies present different abundance and diversity of plant species. Thus, the aim of this study was to evaluate the microbial C:N:P ratio in soil across three different physiognomies of Cerrado in the Northeast, Brazil, namely campo graminóide (dominance of grasses), cerrado stricto sensu (dominance of grasses, shrubs, low trees, and woody stratum), and cerradão (dominance of woody stratum). Campo graminóide was characterized by lower values of total organic C, N, microbial C:P, N:P, and soil C:N. Cerrado stricto sensu presented average values for most of the measured parameters, while cerradão presented higher values of microbial C, N, P, organic C, N and soil C:P and C:N ratios. The principal component analysis showed that the samples grouped according to the sites, with a clear gradient from campo graminóide to cerradão. Therefore, the differences of vegetation across physiognomies of Cerrado influenced the soil microbial C:N:P ratio, where cerradão showed highest microbial C:N:P ratio than soil under campo graminóide.

ABSTRACT The different physiognomies and soil conditions across the Cerrado gradient may influence soil microbial biomass. The present study evaluated the soil microbial biomass and enzyme activity across a preserved Cerrado gradient and correlated these with environmental conditions. The site, sampling period and their interaction influenced soil microbial biomass and activity. Soil conditions, i.e., chemical and microclimatic properties, varied across the Cerrado gradient and influenced soil microbial biomass and activity. The highest and lowest values for microbial biomass and enzyme activity were found in Cerradao and Campo graminoide, respectively, during both seasons. Multivariate analysis showed that the sites were clearly separated into different groups, indicating that distinct physiognomies and environmental conditions influenced soil microbial biomass and enzyme activities.

ABSTRACTINTRODUCTION:The mosquito Aedes aegypti has evolved resistance to pyrethroid insecticides. The present study evaluated Ae. aegypti from Goiânia for the resistant phenotype and for mutations associated with resistance.METHODS:Insecticide dose-response bioassays were conducted on mosquitoes descended from field-collected eggs, and polymerase chain reaction (PCR) was used to genotype 90 individuals at sites implicated in pyrethroid resistance.RESULTS:All mosquito populations displayed high levels of resistance to deltamethrin, as well as high frequencies of the 1016Ile kdr and 1534Cys kdrmutations.CONCLUSIONS:Aedes aegypti populations in the Goiânia area are highly resistant to deltamethrin, presumably due to high frequencies of kdr(knockdown-resistance) mutations.

No Pantanal Sul, as araras-azuis (Anodorhynchus hyacinthinus), espécie em extinção, escolhem preferencialmente o manduvi (Sterculia apetala) como local de nidificação devido principalmente às características físicas da árvore. Porém, a composição química da madeira também pode interferir nesta seleção. Os objetivos deste trabalho foram determinar as principais classes de substâncias químicas presentes nas cascas de S. apetala em duas épocas do ano e seu potencial antifúngico. As cascas de árvores, com e sem a presença de ninhos de A. hyacinthinus, foram coletadas em janeiro (período de chuvas) e agosto (período de seca) de 2012. Por meio das análises fitoquímicas e quantificação de flavonóides, foram selecionadas amostras de uma árvore com ninho e outra sem ninho para determinar seu potencial antifúngico frente à Trichoderma sp. através da porcentagem de inibição do crescimento micelial (PIC). A investigação fitoquímica do extrato etanólico das cascas revelou a predominância de compostos fenólicos e flavonóides. O teor médio de fenóis totais foi superior para as amostras com ninho, em relação às sem ninho, nos dois períodos de coleta e, para flavonóides, os valores foram superiores em janeiro para a amostra com ninho e em agosto, para sem ninho. As amostras selecionadas apresentaram potencial antifúngico, sendo que com ninho, coletada em agosto (auge do período de reprodução das araras-azuis), resultou em um PIC de 51,3%, valor relacionado aos flavonóides e as cumarinas, fator que pode influenciar o sucesso reprodutivo da arara azul e outras espécies de aves nesta região. Este trabalho foi o primeiro a identificar os componentes químicos da casca do tronco de S. apetala.

In the Southern Pantanal, the hyacinth macaw (Anodorhynchus hyacinthinus), an endangered species, often chooses the manduvi tree (Sterculia apetala) as a nesting site, because of its physical properties. In addition, the chemical composition of the wood may also contribute to a nesting selection by the hyacinth macaws. The objective of this study was to determine the main chemical components of S. apetala bark for two seasons, and evaluate its fungicidal potential. Bark samples from S. apetala trees with and without nests of A. hyacinthinus were collected in January (wet season) and August (dry season) of 2012. The inhibition of mycelium growth (MGI) from tree samples with and without nests were assessed using a phytochemical analysis to evaluate their antifungal activity against Trichoderma sp. Phytochemical analysis confirmed the presence of phenolic compounds and flavonoids. In both seasons, samples obtained from nested trees had higher content of total phenols than those collected from non-nested trees. The average content of total flavonoids was higher in January for samples with nest and in August for samples without nest. All selected samples showed antifungal activity, and those with nest collected in August (peak of hyacinth macaw breeding) resulted in an MGI of 51.3%. Therefore, this percentage, related to the content of flavonoids and the presence of coumarins, may influence the reproductive success of hyacinth macaws and other species of birds, in this region. This is the first chemical study report with the stem bark of S. apetala.

This study used chemometric tools and a Geographic Information System (GIS) to determine the influence of organic matter and anthropogenic activity on the distribution of metal species between two major communities of the Middle Negro River Basin-AM. Higher concentrations of metal species were determined in flooded regions. The chemometric analysis showed the affinity of organic matter for potentially toxic metals, indicating its selectivity. GIS spatial analysis has shown that proximity to urban areas is a variable that is likely to influence the pattern of concentration of organic matter, and consequently the distribution of metal species between flooded and non-flooded areas.

O objetivo do presente trabalho foi otimizar o procedimento para extração de substâncias húmicas de turfa, utilizando fluxo contínuo, com diferentes extratores (NaOH, KOH e Na4P2O7). A influência do extrator na capacidade de complexação das substâncias húmicas por macro e micronutrientes também foi investigada. Os resultados mostraram que a extração por fluxo contínuo é eficaz, reduzindo o tempo necessário para o passo de extração e, além disso, indicando que as substâncias húmicas apresentaram elevada afinidade para os nutrientes essenciais Ca2+ e Mg2+. Além disso, as maiores capacidades de complexação foram obtidas quando utilizou o extrator Na4P2O7, mostrando não só a eficiência desse composto como agente de extração, mas também a sua aplicação promissora no processo, uma vez que a sua elevada capacidade de complexação permite disponibilizar os nutrientes complexados, bem como diminuir a quantidade de estes nutrientes que podem ser lixiviados, contribuindo, assim, para evitar contaminação do meio ambiente.

The aim of the present work was to optimize a procedure for extraction of humic substances (HS) from peat, using continuous flow with different extractants (NaOH, KOH and Na4P2O7). The influence of extractant on the complexing capacity of humic substances for macro and micronutrients was also investigated. Our results showed that the extraction by flow is efficient, reducing the time required in the extraction step and, furthermore, indicating that the extracted HS have a high affinity for the essential nutrients Ca and Mg. Moreover, an enhanced complexation was achieved by using Na4P2O7, demonstrating not only the efficiency of this compound as extractant, but also its promising application in the process, since its high complexing capacity allows to make available the complexed nutrients as well as diminishing the amount of these nutrients that could be lixiviated, thus contributing to prevent environmental contaminations.

As elevadas concentrações de mercúrio em diferentes matrizes ambientais na Amazônia têm sido atribuídas a atividades mineradoras. Entretanto, altas concentrações de mercúrio também estão presentes no solo e na água em locais como a Bacia do médio Rio Negro, distantes de fontes emissoras antropogênicas. A região Amazônica é caracterizada por dois diferentes regimes sazonais, bem definidos em períodos de cheias e vazantes. O objetivo deste trabalho foi investigar as influências sazonais na interação entre mercúrio e substâncias húmicas aquáticas (AHS), que são os principais complexantes orgânicos naturais. Os resultados obtidos por análise estatística multivariada dos dados mostraram que as substâncias húmicas possuem diferentes características estruturais, dependendo do período sazonal. A capacidade das substâncias húmicas em formar complexos com Hg(II) não está diretamente relacionada ao seu teor de carbono, mas sim natureza e disponibilidade dos grupos funcionais presentes em sua estrutura. Os grupos funcionais carboxílicos e aromáticos estão diretamente relacionados maior capacidade de complexação de AHS por íons mercúrio.

High mercury concentrations in different environmental matrices in the Amazon have been attributed to mining activities. However, high concentrations of mercury are also present in the soil and water in places like in the middle of the Negro River Basin, which is far away from any anthropogenic emission sources. The Amazon region is characterized by two different regional seasons, with well-defined flood and low water periods. The objective of this work was to investigate the seasonal influences of the interaction between mercury and aquatic humic substances (AHS), which are the main agents of the natural organic complexation capacity. The results of the multivariate statistical analysis of the data showed that the humic substances had different structural characteristics, depending on each season. The ability of humic substances to form complexes with Hg(II) is not directly related to their carbon content, but to the nature and availability of the functional groups present in its structure. The functional groups are carboxylic and aromatic directly related to the higher complexation capacity of AHS by mercury ions.

The region of Aracá River (Middle and Upper Rio Negro-AM) has peculiar characteristics, having soils with atypical profile and high organic matter contents in great deep. The levels of aluminum and iron in the soil samples increased as a function of depth and concentrations of mercury ranged from 0.097 to 0.964 µg g-1. Statistical analysis showed the degree of similarity between soil samples collected. The highest concentrations of mercury in soil samples are directly related to soil higher content of organic matter, directly influencing the fate and bioavailability of mercury species to the environment.

A queratose folicular espinulosa decalvante é afecção rara, de transmissão genética ligada ao X ou esporádica, caracterizada por hiperqueratose folicular e alopecia cicatricial. Inicia-se, geralmente, na primeira infância, exacerbando-se na adolescência. As terapias são pouco efetivas, com tratamento frustrante, quando já há alterações predominantemente cicatriciais. Relata-se caso de criança com quadro de alopecia cicatricial intensa, com alterações precoces (já ao nascimento) e rápida evolução para alopecia difusa cicatricial do couro cabeludo, o que tornou o tratamento limitado e desapontador.

Keratosis follicularis spinulosa decalvans is a rare disease, with genetic transmission either X-linked or sporadic, characterized by follicular hyperkeratosis and cicatricial alopecia. The disease usually begins in early childhood exacerbating throughout adolescence. The therapies are somewhat effective, with frustrating treatment when there are changes which are predominantly cicatricial. It is reported a case of child with intense cicatricial alopecia, with precocious changes (already present at birth) that rapidly evolved to diffuse cicatricial alopecia on the scalp, which has limited the treatment, with disappointing results.

FUNDAMENTOS: O corno cutâneo é lesão acentuadamente hiperqueratótica, cônica e circunscrita, que pode ocultar tanto lesões benignas como malignas. OBJETIVO: Identificar histopatologicamente as principais dermatoses que se apresentam clinicamente como corno cutâneo. MÉTODOS: Estudo histopatológico retrospectivo de 222 cornos cutâneos, a partir de laudos anatomopatológicos do Hospital de Clínicas de Uberlândia entre os anos de 1990 e 2006. RESULTADOS: A média de idade dos pacientes foi de 67,42 anos. O sexo feminino foi mais acometido (64,86%). O tempo médio de evolução foi de 16,92 meses. As localizações mais frequentes das lesões foram: cabeça (35,14%) e membros superiores (31,08%). Observaram-se lesões histopatologicamente benignas em 41,44% e lesões prémalignas ou malignas em 58,56% dos cornos cutâneos estudados. Entre as lesões pré-malignas, a queratose actínica foi encontrada em 83,84% dos casos; entre as malignas, o carcinoma espinocelular correspondeu a 93,75% dos casos. CONCLUSÕES: Este estudo mostrou que a maioria dos cornos cutâneos surgiu sobre áreas do corpo expostas à luz solar, predominantemente, cabeça e membros superiores. Considerando-se a elevada frequência de lesões prémalignas e também a presença de lesões malignas, sugere-se exérese cirúrgica seguida de estudo histopatológico dos cornos cutâneos, para confirmação de diagnóstico específico.

BACKGROUND: Cutaneous horn is a keratotic, conical and circumscribed lesion that can hide both benign or malignant lesions. OBJECTIVE: To identify,from a histopathological point of view, the main clinical dermatoses that are presented ,from a clinical point of view, as cutaneous horn. METHODS: RETROSPECTIVE HISTOPATHOLOGICAL STUDY OF 222 CASES OF CUTANEOUS HORNS THAT WERE CLASSIFIED AS SUCH BY ANATOMICAL-PATHOLOGICAL REPORTS OF THE UNIVERSITY HOSPITAL (HOSPITAL DE CLÍNICAS DE UBERLÂNDIA) FROM 1990 TO 2006. RESULTS: The average age of patients was 67,42. The female sex was more affected (64,86%). The average time of clinical evolution was 16,92 months. Lesions were mostly frequent located on the head (35,14%) and upper limbs (31,08%). Histopathological analysis considered 41,44 % of the lesions as benign and 58,56% as pre-malignant or malignant among the 222 cases of cutaneous horns studied. Within the group of pre-malignant lesions, actinic keratosis was found in 83,84% of the cases; within the group of malignant lesions, squamous cell carcinoma was found in 93,75% of the cases. CONCLUSIONS: This study showed that the majority of cutaneosus horns occured in areas of the body that are exposed to the sun, predominantly head and upper limbs. Considering the high frequency of pre-malignant lesions and also the presence of malignant lesions it is suggested surgical exeresis followed by histopathological study of the cutaneous horns for confirmation of specific diagnosis.