Reply to the discussion by Dimitrios Kolymbas of the article entitled “Characteristic limitations of advanced plasticity and hypoplasticity models for cyclic loading of sands”

The authors welcome the note provided by Prof. Kolymbas regarding his analysis of the characteristic limitations using the Barodesy model. It is very enriching to let users know about the performance of some other constitutive models around the characteristic limitations shown by the authors. Self-criticism of own constitutive developments and letting the users be aware of each model’s advantages and limitations demonstrates the seriousness of each work and is essential for future improvements. In the following, the authors present some comments and thoughts regarding the simulations with the Barodesy mode

Seasonal and spatial distribution of Bacterioplankton in a fluvial-lagunar system of a tropical region: density, biomass, cellular volume and morphologic variation

The temporal and spatial fluctuations of Bacterioplankton in a fluvial-lagunar system of a tropical region (Pitimbu River and Jiqui Lake, RN) were studied during the dry and the rainy periods. The bacterial abundance varied from 2.67 to 5.1 Cells10(7)mL-1 and did not show a typical temporal variation, presenting only small oscillations between the rainy and the dry periods. The bacterial biomass varied from 123 µgC L-1 to 269 µgC L-1 in the sampling sites and the average cellular volume varied from 0.12 to 0.54µm³, showing a predominance of the rods. The temperature showed a positive correlation with the cellular volume of the rods (R=0.55; p=0.02) and vibrio (R=0.53; p=0.03). Significant spatial differences of biomass (Mann Whitney: p=0.01) and cellular volume of the morphotypes (Mann Whitney: p=0.003) were found between the sampling sites. The strong positive correlations of the water temperature and oxygen with bacterioplankton showed a probable high bacterial activity in this system.<br>A variação temporal e espacial do bacterioplâncton em um sistema fluvial-lagunar de região tropical foi estudada em períodos seco e chuvoso. As médias da abundância bacteriana variaram de 2,67 a 5,1 x 10(7) e não exibiram uma variação temporal marcante, tendo apresentado apenas pequenas oscilações entre os períodos chuvoso e seco. A biomassa bacteriana variou de 123 µg C L-1 a 269 µg C L-1 entre os locais de coleta e o volume celular médio de 0,12µm³ a 0,54µm³, ocorrendo predominância de bacilos. A temperatura mostrou correlação positiva com o volume celular de bacilos (R=0,55; p=0,02) e de vibriões (R=0,53; p=0,03). Foram encontradas diferenças espaciais significativas de biomassa (Mann Whitney: p=0,01) e volume celular dos morfotipos (Mann Whitney: p= 0,003), entre os locais de coleta. As fortes correlações positivas da temperatura da água e do oxigênio, com o bacterioplâncton, são sugestivas de uma provavelmente elevada atividade bacteriana nesse sistema