Functional and structural parameters to assess the ecological status of a metal contaminated area in the tropics.

Ecological parameters (soil invertebrates, microbial activity, and plant community) were assessed in a metal contaminated site in an abandoned lead smelter and non-contaminated reference sites, as part of an ecological risk assessment (ERA). Vegetation cover inside the smelter area was lower and presented a more homogenous species composition than outside. A more simplified and less abundant vegetation community within the smelter area also simplified the habitat conditions, which in addition to metal toxicity, impaired the soil microbial and faunal communities. A significant reduction in the feeding activity was observed within the smelter area. Also a significant change in community composition of surface dwelling invertebrates was observed at those sites when compared to sites outside the smelter area. Moreover, basal respiration, microbial biomass C, dehydrogenase and phosphatase activity also decreased in several of these points under the smelter area. As a result, a significant impairment of organic material decomposition in the most contaminated sites was observed. Metal contamination affected the ecological status of the site, leading to a risk for ecosystem functioning and provisioning of ecosystem services like organic matter decomposition and nutrient cycling, even 17 years after the end of smelting activities. Regarding the sensitivity of the ecological parameters assessed, most were able to distinguish sites within the smelter area boundaries from those outside. However, only bait lamina (feeding activity), basal respiration and microbial biomass carbon presented high capacity to distinguish the level of soil contamination, since they were significantly correlated with metal loadings, and thus are promising candidates to be integrated in the Ecological Line of Evidence of an ERA.

Pacientes con sospecha de errores congéntitos del metabolismo: evaluación de la consulta a distancia en el marco del programa de referencia y contrarreferencia / Patients with suspected inborn errors of metabolism: evaluation of distance consultation within the framework of the referral/counter-referral program

Introducción: Los Errores Congénitos del Metabolismo (ECM) son enfermedades poco frecuentes, que para su diagnóstico requieren de especialistas y laboratorios específicos no disponibles en todo el país. El programa de referencia/contra-referencia del Hospital Garrahan ofrece la posibilidad de realizar consultas a través de la Oficina de Comunicación a Distancia (OCD). Objetivos: Evaluar la consulta de pacientes con sospecha de ECM en el marco del programa de referencia/contra-referencia. Comparar estas consultas con las efectuadas en forma presencial. Establecer indicadores de impacto y eficiencia asistencial para estas poblaciones. Explorar la calidad de las consultas a distancia y la percepción del consultante en relación a la respuesta obtenida. Metodología: Estudio prospectivo, observacional y comparativo.Unidad de estudio: consultas hechas a través de la OCD y consultas presenciales realizadas al servicio de ECM desde el 1 de julio de 2010 hasta el 15 de mayo de 2011. Se excluyeron las consultas sin intermediario médico y las motivadas por una pesquisa neonatal patológica. Resultados: Se realizaron 142 consultas a ECM a través de la OCD y 254 a través de otras vías de consulta presencial. El tiempo para responder a las consultas por OCD fue de X 30 hs (mediana 24,2 hs) y para las consultas presenciales (en pacientes internados: X 153,6 hs y mediana 48 hs y en pacientes ambulatorios X 1010 hs, mediana 216 hs). No hubo diferencia significativa entre ambos grupos en diagnósticos realizados (RR 0,58; IC: 0,29-1,14) ni en el tiempo necesario para alcanzar o descartar ECM (log rank test p 0,18). Tampoco hubo diferencias en la mortalidad de ambos grupos (RR: 1,1 IC 0,12-9,44). Conclusiones: La OCD es una forma eficiente de consulta al servicio de ECM con rápida respuesta del especialista,que permite diagnosticar o descartar ECM con frecuencia similar a las consultas por otras vías de consultas.

Introduction: Inborn errors of metabolism (IEM) are rare dis-eases. For the diagnosis they require specialists and special-ized laboratories which are not widely available in the country. The referral/counter-referral program of the Garrahan Hospital provides the possibility of consultation with specialists through the Office of Outreach Communication (OOC). Objectives: To evaluate consultations of patients with a suspected IEM within the framework of the referral/counter-referral program and to compare them with those of patients seen at the hospital; to determine impact and efficiency of care indicators for this patient population; to assess the quality of these distance consultations and how the response is perceived by the con-sulting physician. Methodology: A prospective, observational, and comparative study was conducted. Study subject: Con-sultations made through the OOC and consultations made at the service of IEM between July 1, 2010 and May 15, 2011. Consultations that were not made by a physician or those made following neonatal screening were excluded. Results: 142 consultations for IEM were made through the OOC and 254 were made directly at the service of IEM. Mean time to respond to consultations through the OOC was 30 hours (me-dian 24.2 hours) and mean time to respond to consultations at the service of IEM was 153.6 hours (median 48 hours) for inpatients and 1010 hours (median 216 hours) for outpatients. No significant difference was found in diagnoses made (RR 0.58; CI: 0.29-1.14) or in time needed to reach a diagnosis of or rule out IEM (log-rank test p=0.18) between both groups. There were no differences found in mortality between both groups (RR: 1.1; CI: 0.12-9.44). Conclusions: The OOC is an efficient tool for consultation at the service of IEM with a fast response by the specialist allowing to diagnose or rule out IEM with a response rate similar to other forms of consultation.

Effect of agitation on the performance of an anaerobic sequencing batch biofilm reactor in the treatment of dairy effluents.

Agitation rate is an important parameter in the operation of Anaerobic Sequencing Biofilm Batch Reactors (ASBBRs), and a proper agitation rate guarantees good mixing, improves mass transfer, and enhances the solubility of the particulate organic matter. Dairy effluents have a high amount of particulate organic matter, and their anaerobic digestion presents inhibitory intermediates (e.g., long-chain fatty acids). The importance of studying agitation in such batch systems is clear. The present study aimed to evaluate how agitation frequency influences the anaerobic treatment of dairy effluents. The ASBBR was fed with wastewater from milk pasteurisation process and cheese manufacture with no whey segregation. The organic matter concentration, measured as chemical oxygen demand (COD), was maintained at approximately 8,000 mg/L. The reactor was operated with four agitation frequencies: 500 rpm, 350 rpm, 200 rpm, and no agitation. In terms of COD removal efficiency, similar results were observed for 500 rpm and 350 rpm (around 90%) and for 200 rpm and no agitation (around 80%). Increasing the system's agitation thus not only improved the global efficiency of organic matter removal but also influenced volatile acid production and consumption and clearly modified this balance in each experimental condition.

Potential re-colonisation by cladocerans of an acidic tropical pond.

To predict how re-colonisation of acidified lakes will proceed, at least two approaches are possible: (i) to compare the life history traits of candidate species and determine which one has the highest fitness, and (ii) to simulate a more realistic scenario carrying out experiments with the grouping of the candidate species, so that the intrinsic rate of natural increase of each species is integrated with its sensitivity to low pH and its ability to compete with the other candidate populations. The objective of the present study was to investigate the future re-colonisation of such acidified systems, taking as case-study a tropical pond (Lagoa das Dunas, Camaçari, BA, Brazil) and four species of cladocerans occurring in nearby water bodies (Ceriodaphniacornuta, Ceriodaphniasilvestrii, Latonopsisaustralis and Macrothrix elegans), by comparing the two above mentioned approaches. The second approach included two sets of in situ microcosms experiments, one simulating the re-colonisation by immigrating ephippia, thus using neonates of each species as colonisers, and another simulating the immigration of adults. Both these simulations followed nearly the same trends. The integration of the effects of a higher temperature, a different photoperiod and species competition determined differences in the species densities ranking between the two approaches: life history versus microcosms. The densities of C. cornuta in the microcosms matched the biphasic concentration/response hormetic model, in the simultaneous presence of two increasingly intense stressors (interspecific competition and acidity), with a low-dose stimulation and a high-dose inhibition. The present study provided, thus, a further support to the acceptance of hormesis in ecotoxicology, also at the population level in multispecies experiments.