Wildlife corridors as a connected subgraph problem

Wildlife corridors connect areas of biological significance to mitigate the negative ecological impacts of habitat fragmentation. In this article we formalize the optimal corridor design as a connected subgraph problem, which maximizes the amount of suitable habitat in a fully connected parcel network linking core habitat areas, subject to a constraint on the funds available for land acquisition. To solve this challenging computational problem, we propose a hybrid approach that combines graph algorithms with Mixed Integer Programming-based optimization. We apply this technique to the design of corridors for grizzly bears in the U.S. Northern Rockies, illustrating the underlying computational complexities by varying the granularity of the parcels available for acquisition. The approach that is introduced is general and can be applied to other species or other similar problems, such as those occurring in social networks.     

Estimating the safety performance of urban intersections in Lisbon,Portugal

According to official statistics, a large percentage of crashes in Portugal are reported on urban roads. For instance, from 2004 to 2007, about 70% of all injury accidents and 43% of the fatalities occurred inside urban agglomerations. This important safety problem has also been observed on the urban network of Lisbon. Understanding this significant problem, the Government of the Portuguese Republic via its research grant agency – The Foundation for Science and Technology – funded a project whose primary objective consists of developing tools that would help estimating the safety performance of various components of the urban highway system in Lisbon. This paper documents one component of the safety tools that were developed and describes the steps that were taken to develop predictive models for estimating the safety performance of signalized and unsignalized intersections of Lisbon. Several crash predictive models were developed using the Poisson-gamma modeling framework. Two types of models were estimated: flow-only and models with covariates. They were estimated using crash and other related data collected at 44 three-legged and 50 four-legged intersections for the years 2004–2007, inclusively. It was found that some highway geometric design characteristics were associated with the crashes occurring at urban three- and four-legged intersections in Lisbon.     

Diet of the extinct Lava mouse <Emphasis Type="Italic">Malpaisomys insularis</Emphasis> from the Canary Islands: insights from dental microwear

Malpaisomys insularis is a mouse-like rodent endemic to the eastern Canary Islands. It became extinct during the fourteenth century. It was a remarkable species living under hyperarid conditions. A dental microwear analysis was performed in order to determine its former diet. The elevated number of fine scratches found in Malpaisomys molars suggests that it consumed a significant part of Poaceae, grass consumption leaving the most distinctive features on dental wear facets. A graminivorous diet with a high amount of abrasive items is in agreement with the broad teeth of Malpaisomys, considered as adapted to grass consumption. However, in the absence of potential competitors over its native range, it is likely that Malpaisomys also foraged on dicots to meet higher nutrient and energetic requirements. The ecology of Malpaisomys is discussed from these results in the context of the desertic climatic conditions of the eastern Canary Islands and with a special concern on its small body size in contrast to other large-sized island murine species such as the giant rats of the central Canary Islands.     

Modeling and forecasting daily maximum hourly ozone concentrations using the RegAR model with skewed and heavy-tailed innovations

This paper considers the modeling and forecasting of daily maximum hourly ozone concentrations in Laranjeiras, Serra, Brazil, through dynamic regression models. In order to take into account the natural skewness and heavy-tailness of the data, a linear regression model with autoregressive errors and innovations following a member of the family of scale mixture of skew-normal distributions was considered. Pollutants and meteorological variables were considered as predictors, along with some deterministic factors, namely week-days and seasons. The Oceanic Niño Index was also considered as a predictor. The estimated model was able to explain satisfactorily well the correlation structure of the ozone time series. An out-of-sample forecast study was also performed. The skew-normal and skew-t models displayed quite competitive point forecasts compared to the similar model with gaussian innovations. On the other hand, in terms of forecast intervals, the skewed models presented much better performance with more accurate prediction intervals. These findings were empirically corroborated by a forecast Monte Carlo experiment.     

Copper and lead ion removal from wastewater using fava d’anta fodder (Dimorphandra gardneriana Tulasne)

Environmental Geochemistry and Health - The contamination of bodies of water by potentially hazardous elements has in recent decades become an environmental problem that poses serious risks to...     

Ferronickel slag as free-draining rockfill dike material: a novel waste solution for mining regions

Journal of Material Cycles and Waste Management - Mining sites are vulnerable to erosion and siltation of rivers. While the construction of rockfill dikes can mitigate siltation, existing rockfill...     

Healthcare waste generation in hospitals per continent: a systematic review

Environmental Science and Pollution Research - There are increasing worldwide concerns about the negative impacts of healthcare waste generated in hospitals, especially in low- and middle-income...     

Bioactive Material with Microorganisms can Enhance the Micronutrients Solubilization and Sulfate Availability from Low Reactive Sources: Insight for Application as Coating Fertilizer Granules

Journal of Polymers and the Environment - Fertilization is essential to provide suitable conditions for plant development and crop productivity, but the environmental cost of fertilizers is a...     

A tubular ceramic membrane coated with TiO2-P25 for radial addition of H2O2 towards AMX removal from synthetic solutions and secondary urban wastewater

Environmental Science and Pollution Research - This work aims to integrate several hydrogen peroxide (H2O2) activation mechanisms, photolysis (UVC irradiation), chemical electron transfer (TiO2-P25...