1,721,081 research outputs found
GPU-accelerated multi-objective optimization of fuel treatments for mitigating wildfire hazard
No full textFueltreatmentis considered a suitable way to mitigate the hazard related to potential wildfires on a landscape.
However, designing an optimal spatial layout oftreatment units represents a difficult optimization
problem. In fact, budget constraints, probabilistic nature of fire behaviour and complex interactions
among the different fuel treatment patches, give rise to challenging search spaces on typical landscapes.
In this study, we formulate the design problem in terms of a bi-objective optimization: minimizing both
the extension of land characterized by high fire hazard and the cost of treatment. Then, we propose a
computational approach that leads to a Pareto approximation set by exploiting an adapted version of
the Non-dominated Sorting Genetic Algorithm II (NSGA-II) together with General-Purpose computing
on Graphics Processing Units (GPGPU). Using an application example based on a real landscape, we also
show that the proposed methodology has the potential to effectively support the design of a suitable fuel
treatment for a landscape
GPU-accelerated multi-objective optimization of fuel treatments for mitigating wildfire hazard
No full textEffects of local and systemic immune challenges on the expression of selected salivary genes in the malaria mosquito anopheles coluzzii
Full text linkSalivary glands play a crucial tripartite role in mosquito physiology. First, they secrete factors that greatly facilitate both sugar and blood meal acquisition. Second, the transmission of pathogens (parasites, bacteria and viruses) to the vertebrate host requires both the recognition and invasion of the salivary glands. Third, they produce immune factors that both protect the organ from invading pathogens and are also able to exert their activity in the crop and the midgut when saliva is re-ingested during feeding. Studies on mosquito sialomes have revealed the presence of several female and/or male salivary gland-specific or enriched genes whose function is completely unknown so far. We focused our attention on these orphan genes, and we selected, according to sequence and structural features, a shortlist of 11 candidates with potential antimicrobial properties. Afterwards, using qPCR, we investigated their expression profile at 5 and 24 h after an infectious sugar meal (local challenge) or thoracic microinjection (systemic challenge) of Gram-negative (Escherichia coli, EC) or Gram-positive (Staphylococcus aureus, SA) bacteria. We observed a general increase in the transcript abundance of our salivary candidates between 5 and 24 h after local challenge. Moreover, transcriptional modulation was determined by the nature of the stimulus, with salivary gland-enriched genes (especially hyp15 upon SA stimulus) upregulated shortly after the local challenge and later after the systemic challenge. Overall, this work provides one of the first contributions to the understanding of the immune role of mosquito salivary glands. Further characterization of salivary candidates whose expression is modulated by immune challenge may help in the identification of possible novel antimicrobial peptides
An optimal Cellular Automata algorithm for simulating wildfire spread
No full textRaster-based methods for simulating wildfire spread are computationally more efficient than vectorbased
approaches. In spite of this, their success has been limited by the distortions that affect the fire
shapes. This work presents a Cellular Automata (CA) approach that is able to mitigate the problem of
distorted fire shapes thanks to a redefinition of the spread velocity, where the equations generally used
in vector-based approaches are modified by means of some correction factors. A numerical optimization
approach is used to find the optimal values for the correction factors. The results are compared to the
ones given by two Cellular Automata simulators from the literature under homogeneous conditions.
According to this work, the proposed approach provides better results, in terms of accuracy, at a comparable
computational cost. The proposed approach has then been compared to Farsite, a vector-based
fire-spread simulator, under realistic slope and wind conditions, producing equivalent results in a
reduced computational time
Individuazione dei gradi giorno relativi allo sviluppo della Lobesia botrana (Den. & Schiff.) in Sardegna.
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
