Factors Affecting Infestation by Triatoma infestans in a Rural Area of the Humid Chaco in Argentina: A Multi-Model Inference Approach

Vector-borne transmission of Chagas disease remains a major public health problem in parts of Latin America. Triatoma infestans is the main vector in the countries located in the South American Cone, particularly in the Gran Chaco ecoregion where residual insecticide control has achieved only a moderate, irregular impact. To contribute to improved control strategies, we analyzed the factors associated with the presence and abundance of T. infestans in 327 inhabited houses in a well-defined rural area with no recent vector control interventions in the humid Argentine Chaco. Bugs were found mainly in domiciles, kitchens, storerooms, and chicken coops and nests, particularly where adequate refuge and animal hosts (humans, dogs, cats or poultry) were available. Domiciles constructed from mud were the most often infested, but brick-and-cement domiciles, even in good conditions, were also found infested. Availability of refuge and hosts for T. infestans are key targets for vector control. Ten-fold variations in domestic infestation observed across neighboring villages, and differences in the relevant factors for T. infestans presence with respect to other areas of the Gran Chaco region suggest that host management, building techniques and insecticide use need to be tailored to the local environment, socio-economic characteristics, and climatic conditions

On the nocturnal activity of Tipulinae (Diptera) as measured by a light trap II The influence of temperature cloud and moonlight on the number of insects capured

RESP-2009

Integrating GNSS, IMU, and Imagery for Automatic Orthomosaic Generation

The use of orthomosaic images from aerial or satellite data are increasingly common. While current acquisition methods are cost-effective on a national or regional scale, local scale imagery is prohibitively expensive for many target applications. In this paper we present a combined hardware and software solution, developed at the Geospatial Research Centre, which aims to reduce the cost of acquiring and processing imagery and related data in order to produce orthomosaics in a cost-effective manner on a small, local scale. The hardware component consists of a combined GNSS and inertial solution for determining the position and orientation of a sensor, typically a consumer-grade camera such as a digital SLR. The combination of imagery and navigation metadata allows images to be directly geo-referenced by projecting them on to readily available surface models. Refinements to this initial processing are also presented, which account for boresight and lens calibration error; automatically establishing a correspondence between image features for bundle adjustment; and reducing the visual appearance of any residual misalignments in the final mosaic. The use of commodity sensors and automated processing is an important step in reducing the cost of image acquisition and orthomosaic generation. The methods described are illustrated using two sample sequences. The first is a set of visible images captured from a digital SLR, and the second a set of frames extracted from a thermal video sequence. These two sequences demonstrate the range of imagery that can be processed, which can support applications ranging from environmental monitoring and precision agriculture to urban planning and infrastructure maintenance