As part of the tier 2 of a site-specific risk assessment, this study was the first reporting an intensive in situ application of the bait-lamina assay; two exposure periods (7 and 14 days) were tested during four seasons in ten different sites, within a uranium mine area and at two different depths. The most contaminated sites (by deposition of sludge from the effluent treatment pond) were discriminated after 14 days of exposure because extremely low percentages of feeding activity were recorded. Previous sub-lethal ecotoxicological assays, already had demonstrated that the habitat function of these soils is compromised. Nevertheless, seasonality has proved to have a significant influence on responses. Thus to strength conclusions about the impact of contaminants, the in situ bait-lamina assay should be performed on different annual seasons, at least for temperate regions. It was also found that some environmental parameters (e.g. soil moisture and litter) can act as confounding factors in the bait-lamina assay. 相似文献
Mast syndrome is a complicated form of human hereditary spastic paraplegias, caused by a mutation in the gene acid cluster protein 33, which encodes a protein designated as “maspardin.” Maspardin presents similarity to the α/β-hydrolase superfamily, but might lack enzymatic activity and rather be involved in protein–protein interactions. Association with the vesicles of the endosomal network also suggested that maspardin may be involved in the sorting and/or trafficking of molecules in the endosomal pathway, a crucial process for maintenance of neuron health. Despite a high conservation in living organisms, studies of maspardin in other animal species than mammals were lacking. In the cotton armyworm Spodoptera littoralis, an insect pest model, analysis of an expressed sequence tag collection from antenna, the olfactory organ, has allowed identifying a maspardin homolog (SlMasp). We have investigated SlMasp tissue distribution and temporal expression by PCR and in situ hybridization techniques. Noteworthy, we found that maspardin was highly expressed in antennae and associated with the structures specialized in odorant detection. We have, in addition, identified maspardin sequences in numerous “nonmammalian” species and described here their phylogenetic analysis in the context of metazoan diversity. We observed a strong conservation of maspardin in metazoans, with surprisingly two independent losses of this gene in two relatively distant ecdysozoan taxa that include major model organisms, i.e., dipterans and nematodes. 相似文献
Climate change is a global phenomenon that affects biophysical systems and human well-being. The Paris Agreement of the United Nations Framework Convention on Climate Change entered into force in 2016 with the objective of strengthening the global response to climate change by keeping global temperature rise this century well below 2 °C above pre-industrial levels and to pursue efforts to limit the temperature increase even further to 1.5 °C. The agreement requires all Parties to submit their “nationally determined contributions” (NDCs) and to strengthen these efforts in the years ahead. Reducing carbon emissions from deforestation and forest degradation is an important strategy for mitigating climate change, particularly in developing countries with large forests. Extensive tropical forest loss and degradation have increased awareness at the international level of the need to undertake large-scale ecological restoration, highlighting the need to identify cases in which restoration strategies can contribute to mitigation and adaptation. Here we consider Brazil as a case study to evaluate the benefits and challenges of implementing large-scale restoration programs in developing countries. The Brazilian NDC included the target of restoring and reforesting 12 million hectares of forests for multiple uses by 2030. Restoration of native vegetation is one of the foundations of sustainable rural development in Brazil and should consider multiple purposes, from biodiversity and ecosystem services conservation to social and economic development. However, ecological restoration still presents substantial challenges for tropical and mega-diverse countries, including the need to develop plans that are technically and financially feasible, as well as public policies and monitoring instruments that can assess effectiveness. The planning, execution, and monitoring of restoration efforts strongly depend on the context and the diagnosis of the area with respect to reference ecosystems (e.g., forests, savannas, grasslands, wetlands). In addition, poor integration of climate change policies at the national and subnational levels and with other sectorial policies constrains the large-scale implementation of restoration programs. The case of Brazil shows that slowing deforestation is possible; however, this analysis highlights the need for increased national commitment and international support for actions that require large-scale transformations of the forest sector regarding ecosystem restoration efforts. Scaling up the ambitions and actions of the Paris Agreement implies the need for a global framework that recognizes landscape restoration as a cost-effective nature-based solution and that supports countries in addressing their remaining needs, challenges, and barriers.
Pure fetal blood has been aspirated in utero from the umbilical vein near the placental insertion of the cord using a twenty gauge needle under ultrasound guidance. Sixty-six samples were taken on 63 pregnancies between 17 and 32 weeks of gestation. One to two millilitres of blood can be obtained easily without amniotic fluid dilution or contamination by maternal blood, as confirmed by the measurements of the mean corpuscular volume, the histogram distribution of the red blood cells and the hematocrit. In all cases the Kleihauer test and isoelectrofocusing of the hemoglobins were performed. Coagulation factors were also studied in 60 cases. In 17 cases a medical abortion was voluntarily induced after the procedure, and the follow-up was normal during the observation period after sampling. In the other cases, pregnancies have continued normally and twelve healthy babies have already been born. 相似文献
Understanding the strength and modes of interspecific interactions between introduced and resident species (native or previously introduced) is necessary to predict invasion success. We evaluated different mechanisms of interspecific competition among four species of polyphagous fruit flies (Diptera: Tephritidae) from the island of La Reunion: one endemic species, Ceratitis catoirii, and three exotic species, C. capitata, C. rosa, and Bactrocera zonata, that have successively invaded the island. Larval competition experiments, i.e., co-infestations of the same fruit, and behavioral interference experiments measuring the ability of one female to displace another from a fruit, were performed among all pairs of the four species. We observed asymmetric and hierarchical interactions among species in both larval and adult interference competition. In agreement with the hypothesis that invasion is competition-limited, the competitive hierarchy coincided with the temporal sequence of establishment on the island, i.e., each newly established species tended to be competitively dominant over previously established ones. 相似文献