164 research outputs found
Comparative pollen preferences by africanized honeybees Apis mellifera L. of two colonies in Pará de Minas, Minas Gerais, Brazil
Pollen analysis in honey samples from the two main producing regions in the Brazilian northeast
Spatial distribution of pollen grains and spores in surface sediments of Guanabara Bay, Rio de Janeiro, Brazil
Palynological evidence of the replacement of the hygrophilous forest by field vegetation during the last 7,000 years B.P. in the northern coast of Rio de Janeiro, Brazil
Pollen types and levels of total phenolic compounds in propolis produced by Apis mellifera L. (Apidae) in an area of the Semiarid Region of Bahia, Brazil
Paleoenvironment interpretation of a 1760 years B.P. old sediment in a mangrove area of the Bay of Guanabara, using pollen analysis
Pulmonary hemorrhage syndrome associated with dengue fever, High-resolution computed tomography findings: a case report
Dengue hemorrhagic fever is an acute infectious disease caused by dengue virus. We described the high-resolution CT findings in a 70-year-old male with the disease, which was diagnosed by clinical examination and confirmed by serological methods. High-resolution CT demonstrated bilateral areas of consolidation with air bronchogram and ground glass opacities, as well as small bilateral pleural effusions. Dengue hemorrhagic fever should be considered in the differential diagnosis of diffuse pulmonary hemorrhage
Detection of Hepatitis B Virus Antigens in Paraffin-embedded Liver Specimens from the Amazon Region, Brazil
Removal of clay by stingless bees: load size and moisture selection
Some organisms disperse energy, associated with the transportation of resource, which is not necessarily food. Stingless bees of Central Amazonia (Melipona flavolineata and M. lateralis) collect clay in banks along streams for nest building. The moisture of the clay varies along the bank, and bees collect clay from specific location, indicating that there is some sort of preference regarding their selection. This study aims at identifying: if larger bees carry more clay; if there is a preference for moisture of substrates; and if bees are less efficient accumulating and transporting clay when it is wet. In order to do so, I measured the size of the bees and of the pellets of clay found in the corbicula. I set up a field experiment to test substrate preferences. The amount of clay transported, increased exponentially in accordance to the size of the bee, and the preferred substrate was the driest clay. The amount and the efficiency of removal of clay were not affected by the moisture of the substrate. Despite the wet clay being denser, it does not reduce the efficiency of exploitation of the resource, but suggests that bees spend more energy to carry the same quantity of wet clay, which may be the underlying mechanism explaining their preference for removing drier clay.Alguns organismos têm custos energéticos associados com o transporte de recursos, que não necessariamente são alimentos. Algumas abelhas sem ferrão da Amazônia Central (Melipona flavolineata e M. lateralis) coletam argila na margem de córregos para a construção do ninho. A umidade da argila varia ao longo do barranco e as abelhas coletam argila de pontos específicos, o que sugere que há preferência. Aqui testo se abelhas maiores transportam mais argila; se existe preferência pela umidade do substrato; e se abelhas são menos eficientes na coleta e transporte de argila com elevada umidade. Para isso, eu medi o tamanho das abelhas e das agregações de argila na corbícula. Eu realizei um experimento de campo para testar a preferência de umidade do substrato. A quantidade de argila transportada aumentou exponencialmente com o tamanho da abelha e o substrato preferido foi o de menor umidade. A quantidade de argila removida e a eficiência de remoção não foram influenciadas pela umidade do substrato. A argila com maior umidade é mais densa, o que sugere que as abelhas gastam mais energia para transportar a mesma quantidade de argila quando ela está mais úmida. Esse pode ser o mecanismo para explicar a preferência de remoção pela argila com menor umidade.Univ Fed Mato Grosso do Sul, Ecol Lab, Programa Posgrad Ecol &Conservacao, BR-79070900 Campo Grande, MS, BrazilUniv Estadual Paulista, Dept Ecol, Programa Posgrad Ecol &Biodiversidade, BR-13506900 Rio Claro, SP, BrazilUniv Estadual Paulista, Dept Ecol, Programa Posgrad Ecol &Biodiversidade, BR-13506900 Rio Claro, SP, Brazi
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