Effect of copper on soil functional stability measured by relative soil stability index (RSSI) based on two enzyme activities

Copper can affect essential processes in soils, often for long periods. Enzyme activity is considered a sensitive indicator to evaluate soil health and the potential toxic impact of a soil contaminant. Nevertheless, there is heterogeneity in the responses from enzyme activity assays because of the influence of pH and other physicochemical parameters on both enzyme activity and metal speciation. This leads to complications when comparing soils and limits the validity of the results. To overcome these problems, this paper evaluates resistance and recovery, quantified by using a relative soil stability index (RSSI), of the beta-glucosidase and protease activities towards an additional heat disturbance (17 h at 60 degrees C) in soils where soil organic matter, pH and Cu content were modified in a factorial setup. Chemical analyses (dissolved Cu, pCu(2+), dissolved organic carbon, pH) were performed both before the heat-perturbation and after the enzyme activity monitoring period. Results show that soil pH did not interfere with the RSSI scores of both enzymes. beta-glucosidase RSSI scores were scarcely affected by copper, making it inappropriate for evaluating copper-induced stress to soils. Protease activity shows stimulations of up to 2.5 times the activity of the unperturbed control in uncontaminated samples only. Thus, the protease RSSI score seems a good indicator for soil health relative to copper contamination given that all samples were affected by the presence of copper and high correlations were observed between RSSI scores and the different copper forms.     

Enhancing the economic potential of organic waste by co-composting using ratio modelling toward a circular economy

Journal of Material Cycles and Waste Management - Co-composting, a circular economy approach to waste management, has economic potential and environmental benefits through nutrient recycling and...     

Sub-lethal hydrops as a manifestation of dehydrated hereditary stomatocytosis in two consecutive pregnancies

Dehydrated hereditary stomatocytosis (DHS) is a rare congenital hemolytic anemia mapping to 16q23–q24. We showed recently that it is part of a pleiotropic syndrome likely to display pseudohyperkalemia and/or different forms of fetal and placental fluid collections. Here, we report a woman with DHS. She had two consecutive pregnancies associated with severe fetal hydrops. Hydrops would probably have been lethal in the absence of appropriate removal of ascites and excess amniotic fluid. In utero exchange transfusion, performed once, was useless, because anemia was not pronounced enough to be the cause of the hydrops. In both newborns, ascites resolved within a week following birth and never recurred. The association of hydrops and hemolytic anemia suggests the possibility of DHS. Symptomatic treatment of the hydrops assists survival until spontaneous resorption occurs. Copyright © 2003 John Wiley & Sons, Ltd.     

Shrub communities as inhibitors of plant succession in southern Quebec

The purpose of our research was to identify shrub species growing in southern Quebec that inhibit ecological succession in power-line corridors. Results are presented in three parts. First, clonal characteristics that allowed the establishment of stable communities were identified. Second, successional vector analysis identified those species that have the potential to inhibit succession. In poorly drained sites those species wereCornus stolonifera, C. obliqua, Salix petiolaris, andSpiraea alba. In well-drained sites, those species wereZanthoxylum americanum, Rubus idaeus, Spiraea alba, Rhus typhina, andThuja occidentalis. Third, analysis of variance showed that there is a significantly larger number of tree seedlings found in adjacent herbaceous communities than found under the dense cover ofCornus stolonifera, C. obliqua, Salix petiolaris, Spiraea alba, Rhus typhina, Rubus idaeus, Thuya occidentalis, andZanthoxylum americanum. These results indicate that the planting of selected shrub species could, through biological control, delay reforestation.     

Setting Realistic Recovery Targets for Two Interacting Endangered Species,Sea Otter and Northern Abalone

Failure to account for interactions between endangered species may lead to unexpected population dynamics, inefficient management strategies, waste of scarce resources, and, at worst, increased extinction risk. The importance of species interactions is undisputed, yet recovery targets generally do not account for such interactions. This shortcoming is a consequence of species‐centered legislation, but also of uncertainty surrounding the dynamics of species interactions and the complexity of modeling such interactions. The northern sea otter (Enhydra lutris kenyoni) and one of its preferred prey, northern abalone (Haliotis kamtschatkana), are endangered species for which recovery strategies have been developed without consideration of their strong predator–prey interactions. Using simulation‐based optimization procedures from artificial intelligence, namely reinforcement learning and stochastic dynamic programming, we combined sea otter and northern abalone population models with functional‐response models and examined how different management actions affect population dynamics and the likelihood of achieving recovery targets for each species through time. Recovery targets for these interacting species were difficult to achieve simultaneously in the absence of management. Although sea otters were predicted to recover, achieving abalone recovery targets failed even when threats to abalone such as predation and poaching were reduced. A management strategy entailing a 50% reduction in the poaching of northern abalone was a minimum requirement to reach short‐term recovery goals for northern abalone when sea otters were present. Removing sea otters had a marginally positive effect on the abalone population but only when we assumed a functional response with strong predation pressure. Our optimization method could be applied more generally to any interacting threatened or invasive species for which there are multiple conservation objectives. Definición de Metas de Recuperación Realistas para Dos Especies en Peligro Interactuantes, Enhydra lutris y Haliotis kamtschatkana     

Homing pigeons do extract directional information from olfactory stimuli

Summary Two groups of pigeons were kept from fledging time in two cages fully exposed to winds. From time to time, the cage containing experimentals was additionally exposed to an artificial air current coming from a specific direction and carrying a scent of benzaldehyde. When both groups were exposed to benzaldehyde scent during transportation and at the release site, the control birds flew homeward, whereas the experimentals oriented in the direction roughly opposite that from which they were used to perceiving the benzaldehyde at the loft. When benzaldehyde was not applied, experimental pigeons were homeward oriented like controls.     

Cerebro-costo-mandibular syndrome in a father and a female fetus: early prenatal ultrasonographic diagnosis and autosomal dominant transmission

Ultrasonography in a female fetus revealed cystic cervical hygroma, severe micrognathia, and vertebral and upper limb anomalies suggestive of cerebro-costo-mandibular syndrome (CCMS) which was diagnosed ultrasonographically at 16 weeks' gestation. The father is affected and presents with a Pierre Robin sequence, short stature and typical costovertebral anomalies. CCMS is a rare and severe disorder. The high frequency of sporadic cases, vertical transmission, and the excess of sibs affected via horizontal transmission suggest dominant autosomal mutation with possible germinal mosaicism. The vertical familial case detailed in the present report is a reminder of the high risk when one parent or one sibling is affected and the extreme variability of phenotype and costal ossification. Early prenatal ultrasound diagnosis is possible in a severely affected fetus. Copyright © 2001 John Wiley & Sons, Ltd.     

2,3,7,8-Substituted PCDDs and PCDFs in sea lion (Otaria flavescens) skin biopsies from two South-western Atlantic populations

Congener specific 2,3,7,8-chlorinated PCDDs and PCDFs were determined in skin biopsies taken from sea lions (Otaria flavescens) living in two areas of the South-western Atlantic on the coast of Argentina (Mar del Plata and Punta Bermeja). This is the first report on PCDDs and PCDFs in sea lion skin biopsies from the southern hemisphere. Differences were found in the congener pattern according to the sampling area. Animals living in the polluted area (Mar del Plata harbour) had detectable levels of all seventeen 2,3,7,8-substituted congeners. Sea lions living in a control environment (Punta Bermeja, Patagonia) only exhibited 5 detectable congeners out of all seventeen 2,3,7,8-substituted congeners. However, total levels were low in both colonies studied. These data are consistent with previous work which has indicated that dioxins occur at relatively low levels in marine mammals, possibly due to rapid catabolism or elimination.