Alteration in soil fauna due to soil management and crop rotation in a long-term experiment

The evaluation of the population of meso and macrofauna organisms has been receiving attention in different studies related to soil quality. Therefore, the present study had as objective to evaluate the population of macro and mesofauna organisms, in an experimental area installed for 26 years in Paraná / RS. Among the 11 existing treatments, six were selected by lot, grew in a Conventional and No-tillage system. Soil fauna organisms were captured at 10 cm depth. The method used for the extraction of edaphic organisms was Tüllgren funnel. The collections were executed in blocks and repetitions that represented 312 samples. In the autumn, 60,138 m-2 individuals were estimated, and in the summer they were 28,348 m-2 individuals. The adoption of the long-term no-tillage system favors the biodiversity of the soil fauna in relation to the soil that has been undergoing two years of cultivation and four annual harrows since 1976. The native forest soil is more biodiverse than the cultivated one. The most representative edaphic taxon in the autumn were Acari, Collembola and Diptera, and in the summer they were Acari, Collembola, Hymenoptera and Larva of Lepidoptera. The phytosanitary management of the areas influence the diversity indexes of the edaphic fauna. The soil moisture abiotic factor acts severely under the edaphic fauna in the summer, being more evident in the conventional cropping system. The collection season conditioned to the abiotic factors - soil moisture and temperature - influences the density of individuals, species richness and the Shannon and Pielou indexes

Deep neck infection after third molar extraction: A case report

Deep neck infections are associated with high morbidity rates in dentistry. Early diagnosis and intervention play an essential part in decreasing morbidity rates. The present study aims to report a case of odontogenic deep neck infection after third molar extraction. A 51-year-old male patient underwent extraction of the mandibular right third molar. Seven days later, the patient developed symptoms and signs of progressive infection. Laboratorial and radiologic examinations in association with clinical investigations confirmed deep neck infection. Extraoral drainage was performed under orotracheal intubation. Postoperative laboratory tests and clinical examinations revealed signs of complete remission within a follow-up period of 10 days. Considering the invasive nature of pathogens related to deep neck infections, it is possible to infer that a combination of accurate diagnosis and early intervention plays an essential role in the field of maxillofacial surgery and pathology

Interaction between humic substances and metallic ions: a selectivity study of humic substances and their possible therapeutic application

The complexation capacity of humic substances extracted from peat samples taken from the Mogi River in Ribeirao Preto, SP, Brazil, was determined using metal ions (Al(III), Pb(II), Cr(VI) and Cd(II)), yielding the following order of affinity: Cr(VI)< Cd(II)<Pb(II)<Al(III). An oral LD50 test showed that these humic substances are nontoxic up to a maximum concentration of 512 mg kg-1. These findings reinforce the possibility of using humic substances as a metal detoxicant. ©2007 Sociedade Brasileira de Química

Current knowledge and future prospects of lima bean (Phaseolus lunatus)-rhizobia symbiosis

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.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

Substâncias Húmicas: Possibilidade de um Novo Agente Terapêutico

Humic substances (HS) are heterogeneous molecular aggregates, which have no defined structure and constitute the principal fraction of natural organic matter. They can act as complexation agents, due to their high density of functional groups, and therefore directly influence the transport, accumulation, bioavailability and toxicity of different substances. Metals are important environmental pollutants, since they are widely used during human activities, and following release are not either chemically or biologically degraded. Treatment of acute poisoning in humans caused by potentially toxic metals has employed complexation agents such as ethylenediaminetetraacetic acid (EDTA) or -aminoacids. However, some limitations of these materials such as the lack of selectivity of EDTA and the high cost of -aminoacids have provided the incentive for a search for alternatives. Previous studies of the properties of HS indicate their possible use as an alternative to these chelanting agents.Substâncias húmicas (SH) são agregados moleculares heterogêneos, possuem estrutura indefinida e constituem a principal fração da matéria orgânica natural. Devido ao elevado número de grupos funcionais presentes em sua estrutura, podem atuar como agentes complexantes, influenciando diretamente o transporte, acúmulo, biodisponibilidade e toxicidade de diferentes substâncias. Dentre os contaminantes ambientais, se destacam os metais, pela sua ampla aplicabilidade em diferentes setores e por não sofrerem degradação química ou biológica. O tratamento de intoxicações por metais potencialmente tóxicos em seres humanos vem sendo realizado por agentes complexantes, como o etilenodiaminotetraácetico (EDTA) e os -aminoácidos. Entretanto, algumas limitações, como a falta de seletividade do EDTA e o elevado custo dos -aminoácidos, têm incentivado a busca por outras substâncias quelantes. Nesse sentido, este artigo aborda as principais propriedades descritas na literatura que tornam as substâncias húmicas uma interessante alternativa como agente terapêutico, em casos de intoxicações por metais potencialmente tóxicos

Changes in the bacterial rare biosphere after permanent application of composted tannery sludge in a tropical soil

Composted tannery sludge (CTS) promotes shifts in soil chemical properties, affecting microbial communities. Although the effect of CTS application on the bacterial community has been studied, it is unclear whether this impact discriminates between the dominant and rare species. This present study investigated how the dominant and rare bacterial communities respond over time to different concentrations of CTS application (0, 2.5, 5, 10, and 20 tons/ha) for 180 days. The richness of operational taxonomic units (OTU) was 30-fold higher in the rare than in the dominant biosphere. While some phyla shifted their relative abundance differently in the dominant and rare biosphere, some genera increased their relative abundance under higher CTS concentrations, such as Nocardioides (∼100%), Rubrobacter (∼300%), and Nordella (∼400%). Undominated processes largely governed the dominant biosphere (76.97%), followed by homogeneous (12.51%) and variable (8.03%) selection, and to a lesser extent, the dispersal limitation (2.48%). The rare biosphere was driven by the CTS application as evidenced by the exclusively homogeneous selection (100%). This study showed that the rare biosphere was more sensitive to changes in soil chemical parameters due to CTS application, which evidences the importance explore this portion of the bacterial community for its biotechnological use in contaminated soils.</p