A review of postfeeding larval dispersal in blowflies: implications for forensic entomology

Immature and adult stages of blowflies are one of the primary invertebrate consumers of decomposing animal organic matter. When the food supply is consumed or when the larvae complete their development and migrate prior to the total removal of the larval substrate, they disperse to find adequate places for pupation, a process known as postfeeding larval dispersal. Several important ecological and physiological aspects of this process were studied since the work by Green (Ann Appl Biol 38:475, 1951) 50 years ago. An understanding of postfeeding larval dispersal can be useful for determining the postmortem interval (PMI) of human cadavers in legal medicine, particularly because this interval may be underestimated if older dispersing larvae or those that disperse longer, faster, and deeper are not taken into account. In this article, we review the process of postfeeding larval dispersal and its implications for legal medicine, in particular showing that aspects such as burial behavior and competition among species of blowflies can influence this process and consequently, the estimation of PMI.     

The role of wetlands in the chromophoric dissolved organic matter release and its relation to aquatic ecosystems optical properties. A case of study: Katonga and Bunjako Bays (Victoria Lake; Uganda)

Chromophoric Dissolved Organic Matter (CDOM) is an important component in freshwater and marine ecosystems and plays direct and indirect role in biogeochemical cycles. CDOM originates from the degradation process of organic materials, usually macrophytes and planktons. The present work examines the importance of wetland derived CDOM on the optical and bio-optical properties of two bays of Lake Victoria (Uganda, Africa). This was achieved by determining the attenuation and extinction coefficients of filtered and unfiltered water samples from two equatorial bays on the Ugandan coastline of Lake Victoria. Katonga Bay is a wetland lined bay that receives water from the Katonga river, while Bunjako Bay is an outer bay between Katonga Bay and Lake Victoria. The results showed that attenuation was highest in Katonga Bay and the role of CDOM is most dominant near the river inlet. The quantity and quality of CDOM is extremely different in the two bays: in Katonga Bay it is possible to hypothesize a terrestrial origin of CDOM (transported by the wetland river). On the contrary, in Bunjako Bay, spectral measurements of absorption indicate a modified CDOM and/or alternative CDOM source. The terrestrial CDOM in Katonga Bay is more capable of absorbing harmful UV radiation than the CDOM present in the Bunjako Bay. The resulting optical environment in the former bay presented a water column with a very limited penetration of harmful UV radiation, while a higher penetration was observed in the Bunjako Bay.     

Development projects for small rural communities in the Brazilian Amazon region as potential strategies and practices of climate change adaptation

Climate scenarios for the Amazon region (Brazil) indicate an increase in temperature and a precipitation decrease, affecting society and economic activities, particularly small-scale rural communities. The research aims to identify, describe and evaluate factors present in sustainable development projects for small rural communities (Type- A Demonstration Projects - PDA and Alternatives to Deforestation and Burnt Projects - PADEQ), already implemented, for recognizing its potential use as strategies for adaptation to climate change for small rural communities in the Amazon region. The researches, concerning fifteen projects in Rondonia, Para and Mato Grosso States, were developed through document analysis, technical visits, and interviews with stakeholders of three projects about the community perception, vulnerability and adaptation capacity. The analysis of documents regarding the potential success of the projects highlights their short history, important in the local context, prospects for continuity, and community participation in decision making. Few activities developed in projects could be associated with climate change adaptation practices. Two strategies and practices are the most important: the social organization and the process of awareness and training of the community, and the diversification of the types and forms of agricultural production. The interviews indicate that adaptation is implemented in projects, but without considering the pressures of climate variability and change. While these projects were not planned in the context of climate change, the greatest role of the projects relates to the strengthening of the already existing adaptation capacity, creating good conditions for incorporation of new strategies and adaptation measures, now clearly associated to the objective to reduce the vulnerability to climate change and variability impacts.     

Choice of macroinvertebrate metrics to evaluate stream conditions in Atlantic Forest, Brazil

The development of biomonitoring programs based on the macroinvertebrate community requires the understanding of species distribution patterns, as well as of the responses of the community to anthropogenic stressors. In this study, 49 metrics were tested as potential means of assessing the condition of 29 first- and second-order streams located in areas of differing types of land use in São Paulo State, Brazil. Of the sampled streams, 15 were in well-preserved regions in the Atlantic Forest, 5 were among sugarcane cultivations, 5 were in areas of pasture, and 4 were among eucalyptus plantations. The metrics were assessed against the following criteria: (1) predictable response to the impact of human activity; (2) highest taxonomic resolution, and (3) operational and theoretical simplicity. We found that 18 metrics were correlated with the environmental and spatial predictors used, and seven of these satisfied the selection criteria and are thus candidates for inclusion in a multimetric system to assess low-order streams in São Paulo State. These metrics are family richness; Ephemeroptera, Plecoptera and Trichoptera (EPT) richness; proportion of Megaloptera and Hirudinea; proportion of EPT; Shannon diversity index for genus; and adapted Biological Monitoring Work Party biotic index.     

An integrated air quality forecast system for a metropolitan area

Air quality forecasting is an important issue in environmental research, due to the effects that air pollutants have on population health. To deal with this topic, in this work an integrated modelling system has been developed to forecast daily maximum eight hours ozone concentrations and daily mean PM10 concentrations, up to two days in advance, over an urban area. The presented approach involves two steps. In the first step, artificial neural networks are identified and applied to get point-wise forecasting. In the second step, the forecasts obtained at the monitoring station locations are spatially interpolated all over the domain using the cokriging technique, which allows to improve the spatial interpolation in the absence of densely sampled data. The integrated modelling system has been then applied to a case study over Northern Italy, performing a validation over space and time for the year 2004 and analyzing if the limit values for the protection of human health set by the European Commission are respected. The presented approach represents a fast and reliable way to provide decision makers and the general public with air quality forecasting, and to support prevention and precautionary measures.     

Photochemical persistence of sulfa drugs in aqueous medium: kinetic study and mathematical simulations

Environmental Science and Pollution Research - This study aimed at investigating the photochemical behavior of sulfa drugs containing five and six-membered heterocyclic substituents...     

Effect of hybridization with genome exclusion on extinction risk

Human‐induced habitat changes may lead to the breakdown of reproductive barriers between distantly related species. This phenomenon may result in fertile first‐generation hybrids (F₁) that exclude the genome of one parental species during gametogenesis, thus disabling introgression. The species extinction risk associated with hybridization with genome exclusion is largely underappreciated because the phenomenon produces only F₁ hybrid phenotype, leading to the misconception that hybrids are sterile and potentially of minor conservation concern. We used a simulation model that integrates the main genetic, demographic, and ecological processes to examine the dynamics of hybridization with genome exclusion. We showed that this mode of hybridization may lead to extremely rapid extinction when the process of genome exclusion is unbalanced between the interbreeding species and when the hybridization rate is not negligible. The coexistence of parental species was possible in some cases of asymmetrical genome exclusion, but show this equilibrium was highly vulnerable to environmental variation. Expanding the exclusive habitat of the species at risk allowed its persistence. Our results highlight the extent of possible extinction risk due to hybridization with genome exclusion and suggest habitat management as a promising conservation strategy. In anticipation of serious threats to biodiversity due to hybridization with genome exclusion, we recommend a detailed assessment of the reproductive status of hybrids in conservation programs. We suggest such assessments include the inspection of genetic content in hybrid gametes.