Preliminary insight into age and growth of the Iberian chub (Leuciscus pyrenaicus) in the sorraia system

An investigation of age and growth in the Iberian chub Leuciscus pyrenaicus Gunther, 1868 revealed a seasonal growth pattern, with annulus formation restricted to a short period of the year (May/June). Maximum ages were 6+ for both sexes. During and after the third year females grew at faster rates than males, and the most important decrease in growth rates occurred between age I! and Ill in males and between age Ill and IV in females. Mean back-calculated standard lengths of III and IV age classes were significantly higher in the River Sorraia. Mean weights of I and II age classes were higher in Sor stream whereas the individuals from III ad IV age classes were heavier in the River Sorraia. Shifts in growth rates arc discussed in relation to seasonal and spatial variations in the environmental conditions as well as to sexual maturity

The differential role of social networks. Strategies and routes in Brazilian migration to Portugal and the Netherlands

Abstract This paper draws on qualitative and quantitative data on the migration experiences of Brazilians living in Portugal and the Netherlands to reflect and expand upon the existing knowledge on the role of social networks in migration processes. We consider different migrant profiles based on principal migration motives to identify differentiated socio-demographic profiles and relate these to migration strategies. We show that differences in the ways migrants access and use social networks in their migration projects can be related to these different migration motives and profiles. Simultaneously, we compare two distinct immigration contexts both in terms of contemporary immigration regimes and working opportunities and historical links to Brazil. Our findings demonstrate that migration scholars need to move beyond the narrow conceptualisation of social networks based on community or kin relationships, to consider multiple configurations involving different agents – both in the origin and destination countries – at different stages of the migration process. In addition, we show that future analyses would benefit from taking into account the differences between migrants driven by distinct motivations in different places

Feeding behaviour of Barbus Bocagei assessed under a spatio-temporal approach

The feeding behaviour of Barbus bocagei was assessed in a lowland system by a two years survey Of two contrasting sites also talking into account, for the first time diurnal changes of fish diet and benthos availability

Performance analysis of pressurized irrigation systems operating on-demand using flow-driven simulation models

On-demand pressurized irrigation systems are designed to deliver water with the flow rate and pressure required by the farm irrigation systems, sprinkling or micro-irrigation, and respecting the time, duration and frequency decided by the farmers. Due to the variation in farm demand along the season and the day, a large spatial and temporal variability of flow regimes occurs in these systems, which may affect the performance of the farm systems and the yields of the irrigated crops. Therefore, there is a need to analyse those systems to identify and solve performance problems. In this research, two simulation models for the analysis of irrigation systems operating on-demand, ICARE and AKLA, are used and compared to assess the hydraulic performance of the irrigation network of the Lucefecit Irrigation System, in Southern Portugal. ICARE assesses the global performance of the irrigation system through the indexed characteristic curves, while AKLA provides for the identification of the relative pressure deficit and reliability at every hydrant. Both models adopt a flow-driven analysis approach, performing the analysis for multiple flow regimes. To support the hydraulic characterization of the system and for calibration of the steadystate hydraulic model, field measurements were performed at selected nodes of the network, including four hydrants. The analysis with ICARE does not provide for a sufficient identification of problems. In fact, poor performance is indicated when a few hydrants operate below the minimum pressure set at design. Differently, the analysis with AKLA, applied at the hydrant level, shows that the performance of the Lucefecit system is generally acceptable. AKLA identifies which hydrants operate below the required pressure and, therefore, allows to support any eventual related improvement. Results show that the performance of the system highly improved when changing the piezometric elevation from 260 to 265m a.s.l. However, this improvement is not sufficient because three hydrants still have high relative pressure deficit and low reliability. Solutions for those hydrants require increasing diameters of network pipes supplying them

Estudo comparativo de uma técnica de infestação artificial de células de obreiras quando aplicada isoladamente ou em simultâneo com outras técnicas

Este estudo teve como objectivo investigar a resposta ele colónias ele abelhas Apis melífera L. à infestação artificial de células ele obreira com ácaros Varroa Destuctor. Alvéolos com criação de obreiras de 7 dias após a operculação, de 6 colmeias, foram artificialmente infestados com ácaros. Em 3 colmeias, as células de obreira foram infestadas com ácaros mortos por congelação (ACV). Nas 3 colmeias restantes esta técnica foi também aplicada (CV) mas em conjunto com outras duas técnicas ele infestação: ácaros mortos naturalmente e ácaros vivos. Foram realizadas duas repetições por colmeia e um total de 4 ensaios nos meses de Junho a Setembro. A resposta higiénica das abelhas foi registada 24 horas após a infestação. As abelhas manifestaram dois comportamentos diferentes. No primeiro limparam completamente os alvéolos, retirando os ácaros e as crias das abelhas. No segundo, desopercularam e reopercularam os alvéolos, retirando os ácaros mas a cria permaneceu nos alvéolos. As abelhas manifestaram melhor o comportamento I em relação à introdução de ácaros mortos (p<-0,01), quando são aplicados todos os métodos em simultâneo

A versatile reactor for continuous monitoring of biofilm properties in laboratory and industrial conditions

Aims: The understanding of the dynamics of surface microbial colonization with concomitant monitoring of biofilm formation requires the development of biofilm reactors that enable direct and real-time evaluation under different hydrodynamic conditions. Methods and Results: This work proposes and discusses a simple flow cell reactor that provides a means to monitoring biofilm growth by periodical removing biofilm-attached slides for off-line, both non-destructive and destructive biofilm analyses. This is managed without the stoppage of the flow, thus reducing the contamination and the disturbance of the biofilm development. With this flow cell, biofilm growth and respiratory activity can be easily followed, either in well-defined laboratory conditions or in an industrial environment. Conclusions, Significance and Impact of the Study: The reproducible and typical biofilm development curves obtained, validated this flow cell and confirmed its potential for different biofilm-related studies, which can include biocidal treatment.Instituto de Biotecnologia e Química Fina(IBQF)

Homocysteine levels in pediatric renal transplant recipients.

Transplant Proc. 2003 May;35(3):1093-5. Homocysteine levels in pediatric renal transplant recipients. Mota C, Fonseca I, Santos MJ, Costa T, Faria MS, Henriques AC, Sarmento AM, Pereira E, Pereira M. Department of Paediatric Nephrology, Maria Pia Children's Hospital, R. da Boavista, 827, 4050-111, Porto, Portugal. [email protected] PMID: 12947872 [PubMed - indexed for MEDLIN

Microcystin-LR activates the ERK1/2 kinases and stimulates the proliferation of the monkey kidney-derived cell line Vero-E6

Microcystin-LR (MCLR) is a peptide produced by freshwater cyanobacteria that induces severe hepatotoxicity in humans and animals. MCLR is also a potent tumour promoter and it has been proposed that this activity is mediated by the inhibition of protein phosphatases PP1/PP2A, possibly through the activation of proto-oncogenes c-jun, c-fos and c-myc. However, the mechanisms underlying MCLR-induced tumour promotion are still largely unknown, particularly in non-liver cells. In previous studies we have demonstrated that micromolar concentrations of MCLR induce cytotoxic effects in the kidney Vero-E6 cell line. The purpose of the present work was to evaluate whether the exposure to subcytotoxic concentrations of MCLR was sufficient to induce the proliferation of Vero-E6 cells. Through BrdU incorporation assay we show that at nanomolar concentrations MCLR stimulates cell cycle progression in Vero-E6 kidney cell line. Moreover, the analysis of mitogen-activated protein kinases p38, JNK and ERK1/2 activity revealed that the proliferative effect of MCLR is associated with the activation of the pro-proliferative ERK1/2 pathway. These results emphasise the importance to confirm in vivo the impact of MCLR on tumour promotion at kidney level