Ecosystem models of bivalve aquaculture: Implications for supporting goods and services

In this paper we focus on the role of ecosystem models in improving our understanding of the complex relationships between bivalve farming and the dynamics of lower trophic levels. To this aim, we review spatially explicit models of phytoplankton impacted by bivalve grazing and discuss the results of three case studies concerning an estuary (Baie des Veys, France), a bay, (Tracadie Bay, Prince Edward Island, Canada) and an open coastal area (Adriatic Sea, Emilia-Romagna coastal area, Italy). These models are intended to provide insight for aquaculture management, but their results also shed light on the spatial distribution of phytoplankton and environmental forcings of primary production. Even though new remote sensing technologies and remotely operated in situ sensors are likely to provide relevant data for assessing some the impacts of bivalve farming at an ecosystem scale, the results here summarized indicate that ecosystem modelling will remain the main tool for assessing ecological carrying capacity and providing management scenarios in the context of global drivers, such as climate change

Produtividade de híbridos de abobrinha italiana cultivados sob diferentes coberturas de solo Yield of italian hibrid squash on different soil coverings

Um experimento foi realizado na empresa Sakata Seed Sudamerica Ltda., em Bragança Paulista-SP, de 22 de agosto a 11 de outubro de 2006, com o objetivo de avaliar diferentes tipos de materiais para cobertura do solo e seu efeito na ocorrência de frutos com sintomas de viroses e na produtividade de dois híbridos de abobrinha. O delineamento experimental utilizado foi de blocos casualizados, com quatro repetições. Os tratamentos foram arranjados em esquema de parcelas subdivididas, sendo as parcelas constituídas por seis tipos de cobertura de solo (polietileno preto, polietileno prata, polietileno branco, polipropileno preto, casca de arroz e solo descoberto); as sub-parcelas foram constituídas de dois híbridos de abobrinha [Novita Plus (cv. tipo caserta) e Samira (cv. tipo libanesa)]. Observou-se que a técnica de cobertura de solo com plástico, independentemente da coloração utilizada, mostrou-se superior ao solo descoberto para todas as características avaliadas. Entre os tipos de materiais coube o destaque para o polietileno prata que promoveu a maior produtividade e menor infecção de viroses, em relação às demais coberturas de solo. Entre os híbridos, Novita Plus foi superior a Samira para as características de pegamento de frutos, número de frutos por planta e produtividade, além de apresentar 12% a menos de frutos com sintomas de viroses em relação à Samira. Para o híbrido Novita Plus, cabe destacar que a detecção da ocorrência de sintomas de viroses nos frutos teve início somente a partir da oitava colheita nos tratamentos com polietileno prata, branco e casca de arroz. Para 'Samira', os sintomas nos frutos começaram já na segunda colheita nos tratamentos com solo descoberto e polipropileno preto, e a partir da quarta para as outras coberturas de solo.<br>The experiment was carried out in an area of Sakata Seed Sudamerica Ltda. in Bragança Paulista, Brazil, from August 22nd to October 11th, 2006, to evaluate different types of materials for soil covering and its effect on fruits with virus symptoms and on the yield of two hybrids of squash. The experimental design was randomized blocks, with four replications. The treatments followed a split-plot cheme, evaluating six soil coverings (black, silver and white polyethylene, black polypropylene, rice husk and bare soil) and two hybrids [(Novita Plus (cv. type Caserta) and Samira (cv. type Libanese)]. The technique of plastic soil covering, independently of the material used, was superior to bare soil. Among the materials the treatments using silver polyethylene promoted the highest yield and the lowest percentage of fruits with viruses in comparison to the other soil coverings. Among the hybrids, Novita Plus was superior to Samira in relation to the characteristics of fruit set, number of fruits per plants and yield, besides presenting 12% less fruits with virus symptoms in relation to Samira. For 'Novita Plus', the occurrence of virus symptoms began only at the eighth harvest on the treatments using silver and white polyethylene and rice husk. For 'Samira' the symptoms started at the second harvest on plants submitted to bare soil or black polypropylene and at fourth harvest on the other treatments

Innate immune responses in Lyme borreliosis: enhanced tumour necrosis factor-α and interleukin-12 in asymptomatic individuals in response to live spirochetes

Innate immunity is important for early defence against borrelia spirochetes and should play a role in the clinical outcome of the infection. In order to study early cytokine responses, in vitro differentiated dendritic cells (DCs) and whole blood cells from 21 patients with different clinical outcomes of Lyme neuroborreliosis were stimulated with live borrelia spirochetes. The borrelia-induced secretion of interleukin (IL)-4, IL-10, IL-12p70, interferon (IFN)-γ and tumour necrosis factor (TNF)-α in DCs and IL-1β, IL-6, IL-8, IL-10, IL-12p70, TNF-α, regulated upon activation normal T cell expressed and secreted (RANTES), monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1α, MIP-1β and eotaxin in whole blood cells was measured by enzyme-linked immunospot (ELISPOT) and multiplex arrays, respectively. We found increased numbers of TNF-α-secreting DCs (P = 0·018) in asymptomatic seropositive individuals compared to patients with subacute neuroborreliosis and seronegative controls. Asymptomatic individuals were also found to have elevated levels of IL-12p70 (P = 0·031) in whole blood cell supernatants compared to seronegative controls. These results are in line with previous experiments using cells of the adaptive immune response, indicating that strong T helper type 1 (Th1) proinflammatory responses might be associated with a successful resolution of Lyme disease