Organism-sediment interactions govern post-hypoxia recovery of ecosystem functioning

Hypoxia represents one of the major causes of biodiversity and ecosystem functioning loss for coastal waters. Since eutrophication-induced hypoxic events are becoming increasingly frequent and intense, understanding the response of ecosystems to hypoxia is of primary importance to understand and predict the stability of ecosystem functioning. Such ecological stability may greatly depend on the recovery patterns of communities and the return time of the system properties associated to these patterns. Here, we have examined how the reassembly of a benthic community contributed to the recovery of ecosystem functioning following experimentally-induced hypoxia in a tidal flat. We demonstrate that organism-sediment interactions that depend on organism size and relate to mobility traits and sediment reworking capacities are generally more important than recovering species richness to set the return time of the measured sediment processes and properties. Specifically, increasing macrofauna bioturbation potential during community reassembly significantly contributed to the recovery of sediment processes and properties such as denitrification, bedload sediment transport, primary production and deep pore water ammonium concentration. Such bioturbation potential was due to the replacement of the small-sized organisms that recolonised at early stages by large-sized bioturbating organisms, which had a disproportionately stronger influence on sediment. This study suggests that the complete recovery of organism-sediment interactions is a necessary condition for ecosystem functioning recovery, and that such process requires long periods after disturbance due to the slow growth of juveniles into adult stages involved in these interactions. Consequently, repeated episodes of disturbance at intervals smaller than the time needed for the system to fully recover organism-sediment interactions may greatly impair the resilience of ecosystem functioning.

Importance of heterogeneity in Porhyromonas gingivalis lipopolysaccharide lipid A in tissue specific inflammatory signaling

Lipopolysaccharide (LPS) of Porphyromonas gingivalis exists in at least two known forms, O-LPS and A-LPS. A-LPS shows heterogeneity in which two isoforms designated LPS1435/1449 and LPS1690 appear responsible for tissue specific immune signalingpathways activation and increased virulence. The modification of lipid A to tetra-acylated1435/1449 and/or penta-acylated1690 fatty acids indicates poor growth conditions and bioavailability of hemin. Hemin protects P. gingivalis from serum resistance and the lipid A serves as a site for its binding. The LPS1435/1449 and LPS1690 isoforms can produce opposite effects on the human Toll-like receptors (TLR) TLR 2 and TLR 4 activation. This enabless P. gingivalis to select the conditions for its entry, survival and that of its co-habiting species in the host, orchestrating its virulence to control innate immune pathway activation and biofilm dysbiosis. Thismini review describes a number of effects that LPS1435/1449 and LPS1690 can exert on the host tissues such as deregulation of the innate immune system, subversion of host cell autophagy, regulation of outer membrane vesicle production and adverse effects on pregnancy outcome. The ability to change its LPS1435/1449 and/or LPS1690 composition may enables P. gingivalis to paralyze local pro-inflammatory cytokine production, thereby gaining access to its primary location in periodontal tissue

Questionário específico para sintomas do joelho "Lysholm Knee Scoring Scale": tradução e validação para a língua portuguesa Specific questionnaire for knee symptoms - the "Lysholm Knee Scoring Scale": translation and validation into Portuguese

As doenças do joelho apresentam conseqüências variadas para a função e a qualidade de vida do indivíduo. Para traduzir, validar e verificar as propriedades de medida do questionário específico para sintomas do joelho "Lysholm Knee Scoring Scale" para a língua portuguesa, selecionamos, por conveniência, 50 pacientes (29 homens e 21 mulheres, média de idade 38,7 anos) com lesão de joelho (lesão meniscal, lesão do ligamento cruzado anterior, condromalácia ou artrose). A reprodutibilidade e a concordância ordinal inter e intra-entrevistador foram excelentes (alfa = 0,9). A concordância nominal inter-entrevistadores foi boa (Kappa = 0,7) e intra-entrevistador, excelente (Kappa = 0,8). No processo de validação, correlacionamos o questionário Lysholm com a escala numérica da dor (r=-0,6; p=0,001) e com o índice de Lequesne (r= -0,8; p=0,001). As correlações entre o Lysholm e a avaliação global da saúde pelo paciente e pelo terapeuta apresentaram-se fracas e não significantes. As correlações entre o questionário Lysholm e o SF-36 foram significantes nos aspectos físicos (r = 0,4; p = 0,04), de dor (r = 0,5; p = 0,001) e de capacidade funcional (r = 0,7; p = 0,0001). Concluímos que a tradução e adaptação cultural do "Lysholm knee scoring scale" para o nosso idioma apresentou reprodutibilidade e validade em pacientes com lesão meniscal, lesão do ligamento cruzado anterior, condromalácia ou artrose do joelho.<br>Knee diseases present variable consequences for an individual’s function and quality of life. For the purposes of translating, validating and checking the measurement properties of the specific questionnaire for knee symptoms - the "Lysholm Knee Scoring Scale" - into Portuguese, we selected, for convenience, 50 patients (29 males and 21 females, mean age = 38.7 years) with knee injuries (meniscal injury, anterior cruciate ligament injury, chondromalacia or arthrosis). Reproducibility and ordinal consistency inter- and intra-interviewer were excellent (alpha = 0.9). The nominal consistency inter-interviewers was good (Kappa = 0.7) and intra-interviewer was excellent (Kappa = 0.8). During validation process, we correlated the Lysholm questionnaire with the pain numerical scale (r=-0.6; p=0.001) and with he Lequesne index (r= -0.8; p=0.001). Correlations between Lysholm questionnaire and the global health evaluation by patient and by therapist were poor and not significant. The correlations between Lysholm questionnaire and SF-36 were significant for physical aspects (r = 0.4; p = 0.04), pain (r = 0.5; p = 0.001) and function (r = 0.7; p = 0.0001). We concluded that the translation and cultural adaptation of the "Lysholm knee scoring scale" into our language have proven to be reproducible and valid in patients with meniscal injury, anterior cruciate ligament injury, chondromalacia or knee arthrosis