Spatial variability of macroinvertebrate assemblages and the influence of hydrological and environmental variables along the Sigi River, Tanzania-East Africa

The study of investigating the spatial and temporal variability of macroinvertebrate and their relation to hydrology, hydraulic and environmental factors was done along the Sigi River during two sampling periods in the dry (March) and wet (May) periods of 2012. The river was demarcated based on slope ranges and five river zones were identified as mountains streams (MS), upper foothills (UF), lower foothills (LF), rejuvenated foothills (REJ) and mature lower river (MR). Samples of macroinvertebrate were collected from the five river zones and measurements of hydrological (discharge), hydraulics (Depth, velocity and Froude number) and Environmental (pH, Temperature, substrate, conductivity) parameters were done in each zone. In characterizing the macroinvertebrate assemblages along the Sigi River diversity indices (number of taxa, total abundances, Margalef richness index and ShannonWiener index) were calculated and the most representative species for the spatial and temporal variation were identified. Melanoides and Afronurous showed differences in abundance in two samplings periods while Cleopatra, Potamonautes, Ephemerythus, Neoperla, Caenis, Ceratogomphus and Cheumatopsyche showed significant difference among the river zones. Spearman rank correlation and Distance Linear Model (DistLM) used to revealed physical factors governing the macroinvertebrate assemblages distribution. The study demonstrated that the variation of physical factors like discharge, temperature, conductivity and pH have an important role in the spatial distribution of macroinvertebrate assemblages along the river and the life cycle of macroinvertebrate (Afronurus) is important in determining the temporal variability.

The extinction of Neanderthals and the emergence of the Upper Paleolithic in Portugal

Este trabalho foi apresentado no âmbito de Provas de Agregação na área de Arqueologia. Estas provas académicas, constituídas por 3 fases, são de carácter público. Para cada fase existe um arguente, sendo as fases, respectivamente, a discussão do currículo do candidato, a análise de um relatório de uma disciplina do ensino universitário e uma lição-síntese, seguida de discussão. Esta última prova consiste numa apresentação de uma hora de um tema à escolha e, como parte constituinte das Provas de Agregação, pode ser pensada de duas formas essencialmente opostas: uma de entre as várias lições do programa da disciplina apresentado no relatório acima mencionado, fazendo por isso a descrição de uma qualquer parte do conteúdo desse mesmo programa; ou, pelo contrário, respeitar o título da prova e fazer-se uma verdadeira lição síntese, de carácter inédito.