Fine scale spatial investigation of multiple insecticide resistance and underlying target-site and metabolic mechanisms in Anopheles gambiae in central Côte d’Ivoire

Routine monitoring of occurrence, levels and mechanisms of insecticide resistance informs effective management strategies, and should be used to assess the effect of new tools on resistance. As part of a cluster randomised controlled trial evaluating a novel insecticide-based intervention in central Côte d’Ivoire, we assessed resistance and its underlying mechanisms in Anopheles gambiae populations from a subset of trial villages. Resistance to multiple insecticides in An. gambiae s.s. and An. coluzzii was detected across villages, with dose–response assays demonstrating extremely high resistance intensity to the pyrethroid deltamethrin (> 1,500-fold), and mortality following exposure to pyrethroid-treated bednets was low (< 30% mortality in cone bioassays). The 1014F kdr mutation was almost fixed (≥ 90%) in all villages but the 1575Y kdr-amplifying mutation was relatively rare (< 15%). The carbamate and organophosphate resistance-associated Ace-1 G119S mutation was also detected at moderate frequencies (22–43%). Transcriptome analysis identified overexpression of P450 genes known to confer pyrethroid resistance (Cyp9K1, Cyp6P3, and Cyp6M2), and also a carboxylesterase (COEAE1F) as major candidates. Cyp6P3 expression was high but variable (up to 33-fold) and correlated positively with deltamethrin resistance intensity across villages (r2 = 0.78, P = 0.02). Tools and strategies to mitigate the extreme and multiple resistance provided by these mechanisms are required in this area to avoid future control failures

Evaluating the impact of screening plus eave tubes on malaria transmission compared to current best practice in central Côte d'Ivoire : A two armed cluster randomized controlled trial

Background: Access to long-lasting insecticidal nets (LLINs) has increased and malaria has decreased globally, but malaria transmission remains high in parts of sub-Saharan Africa and insecticide resistance threatens current progress. Eave tubes are a new tool for the targeted delivery of insecticides against mosquitoes attempting to enter houses. The primary objective of this trial is to test whether screening plus eave tubes (SET) provides protection against malaria, on top of universal coverage with LLINs in an area of intense pyrethroid resistance. The trial will also assess acceptability and cost-effectiveness of the intervention. Methods/design: A two-armed, cluster randomized controlled trial will be conducted to evaluate the effect of SET on clinical malaria incidence in children living in central Côte d'Ivoire. Forty villages will be selected based on population size and the proportion of houses suitable for modification with SET. Using restricted randomization, half the villages will be assigned to the treatment arm (SET + LLINs) and the remainder will be assigned to the control arm (LLINs only). In both arms, LLINs will be distributed and in the treatment arm, householders will be offered SET. Fifty children aged six months to eight years old will be enrolled from randomly selected households in each of the 40 villages. Cohorts will be cleared of malaria parasites at the start of the study and one year after recruitment, and will be monitored for clinical malaria case incidence by active case detection over two years. Mosquito densities will be assessed using CDC light traps and human landing catches and a subset of Anopheles mosquitoes will be examined for parity status and tested for sporozoite infection. Acceptability of SET will be monitored using surveys and focus groups. Cost-effectiveness analysis will measure the incremental cost per case averted and per disability-adjusted life year (DALY) averted of adding SET to LLINs. Economic and financial costs will be estimated from societal and provider perspective using standard economic evaluation methods. Discussion: This study will be the first evaluation of the epidemiological impact of SET. Trial findings will show whether SET is a viable, cost-effective technology for malaria control in Côte d'Ivoire and possibly elsewhere. Trial registration: ISRCTN18145556, registered on 01 February 2017 - retrospectively registered

ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences

© 2018 Auhtors. The navigation of pedestrians can be regarded as their movements from one unoccupied space to another unoccupied and connected space. These movements generally occur in three types of environments: Indoor, outdoor, and semi-bounded (top-bounded, and/or side-bounded) spaces. While the two former types of spaces are subject to most of the attention, the latter (semi-bounded) also presents a valuable impact on the navigation behaviour. For example, top-bounded environments (e.g. roofs, shelters, etc.) are very popular for pedestrian navigation since a top structure can offer protection from harsh weather, rain, or strong sun. However, such semibounded spaces are completely missing in current navigation models and systems. This is partly explained by the fact that modelling the space, which is by defining a three-dimensional boundless and extensible component (mainly out of the indoor environment), is a very challenging task. In this paper, we propose a structure-based approach for top-bounded space extraction in the built environment, relying on 3D models. Thanks to the rapid expansion and availability of 3D city models, our approach can help to account for such type of spaces in 3D pedestrian navigation systems

Top-bounded spaces formed by the built environment for navigation systems

Navigation systems help agents find the right (optimal) path from the origin to the desired destination. Current navigation systems mainly offer the shortest (distance or time) path as the default optimal path. However, under certain circumstances, having a least-top-exposed path can be more interesting. For instance, on a rainy day, a path with as many places as possible covered by roofs/shelters is more attractive and pragmatic, since roofs/shelters can offer protection from rain. In this paper, we name environments that covered by roofs/shelters but not completely enclosed like indoors as “top-bounded environments/spaces” (e.g., porches), which are generally formed by built structures. This kind of space is completely missing in current navigation models and systems. Thus, we investigate how to use it for space-based navigation. After proposing a definition, a space model, and attributes of top-bounded spaces, we introduce a projection-based approach to generate them. Then, taking a pedestrian as an example agent, we select generated spaces considering whether the agent can visit/use the identified spaces. Finally, examples and a use case study demonstrate that our research can help to include top-bounded spaces in navigation systems/models. More navigation path types (e.g., least-top-exposed) can be offered for different agents (such as pedestrians, drones or robots)

Semantic enrichment of octree structured point clouds for multi-story 3D pathfinding

3D indoor navigation in multi-story buildings and under changing environments is still difficult to perform. 3D models of buildings are commonly not available or outdated. 3D point clouds turned out to be a very practical way to capture 3D interior spaces and provide a notion of an empty space. Therefore, pathfinding in point clouds is rapidly emerging. However, processing of raw point clouds can be very expensive, as these are semantically poor and unstructured data. In this article we present an innovative octree-based approach for processing of 3D indoor point clouds for the purpose of multi-story pathfinding. We semantically identify the construction elements, which are of importance for the indoor navigation of humans (i.e., floors, walls, stairs, and obstacles), and use these to delineate the available navigable space. To illustrate the usability of this approach, we applied it to real-world data sets and computed paths considering user constraints. The structuring of the point cloud into an octree approximation improves the point cloud processing and provides a structure for the empty space of the point cloud. It is also helpful to compute paths sufficiently accurate in their consideration of the spatial complexity. The entire process is automatic and able to deal with a large number of multi-story indoor environments

Detection of doors in a voxel model, derived from a point cloud and its scanner trajectory, to improve the segmentation of the walkable space

Generation of indoor networks for navigation will normally be done out of standard floor plans that are only 2D and is more often manual than automatic. These floor plans are drawn at a specific time and do not correspond to the reality, moreover some of those buildings were built already differently than designed. Then in due course the building will change both externally and internally. Also objects like furniture will be moved around in the building. If these changes are not updated in the map of the building, it becomes out of date and cannot be used for the creation of indoor navigable models anymore. To enable correct indoor navigation, we will need to have the current data of the indoor environment. This article concentrates on providing a new approach to generate up to date floor plans by using a mobile (and hand held) laser scanner in the fastest way. This device creates a point cloud and the corresponding trajectory at the same time. Because the mobile laser scanner device is operated by a walking human, the trajectory contains information about the surface the person is walking on. In this article, a method is explained for the detection of walkable spaces based on the analysis of the point cloud and its corresponding trajectory provided by the mobile laser scanner. Three steps will be used: voxelization, trajectory analysis and the identification of floor regions. Dynamic objects, doors, and furniture objects are also used to identify the surfaces which are available for navigation purposes. Three types of surfaces are considered: horizontal, slopes, and stairs

Spatio-temporal Change in Land Use and Land Cover: Implications for Conservation of Fina Faunal Reserve in Mali

The natural resources in FINA reserve of Mali are undergoing intense degradation coupled with increased  human pressure on the reserve. Vegetation in this reserve is severely threatened. Existing inventories  regarding such threats are currently out dated. There is, therefore, a crucial need to assess land use and land  cover change in the reserve. The methodological approach in this study has combined LULC change detection  with LULC intensity analysis. Using Landsat images, intensity analysis model was utilised in detecting  changes in land use and land cover in the reserve, and the changes were evaluated in relation to agricultural  activities in the reserve. The results revealed an increase in agricultural land by 2-4% per annum and a  decrease in savannah wood land by 2% per year from 1985 to 2013. Bare land and Savannah woodland were  found to be gradually replaced by agricultural land. The observed transition of vegetation cover to agricultural  land indicates the extent of human pressure on the reserve. Consequently, to preserve these ecosystems,  there is the need to initiate and implement measures aimed at limiting cultivation and other human activities  in the reserve. These measures should integrate food production and forestry, as well as involve rural  community participation through appropriate incentives.Keywords: Land Use and Land Cover Change, Category Level Analysis, Vegetation Dynamics, Fina faunal reserve