Self-organized UAV Traffic in Realistic Environments

We investigated different dense multirotor UAV traffic simulation scenarios in open 2D and 3D space, under realistic environments with the presence of sensor noise, communication delay, limited communication range, limited sensor update rate and finite inertia.We implemented two fundamental self-organized algorithms: one with constant direction and one with constant velocity preference to reach a desired target. We performed evolutionary optimization on both algorithms in five basic traffic scenarios and tested the optimized algorithms under different vehicle densities. We provide optimal algorithm and parameter selection criteria and compare the maximal flux and collision risk of each solution and situation. We found that i) different scenarios and densities require different algorithmic approaches, i.e., UAVs have to behave differently in sparse and dense environments or when they have common or different targets; ii) a slower-is-faster effect is implicitly present in our models, i.e., the maximal flux is achieved at densities where the average speed is far from maximal; iii) communication delay is the most severe destabilizing environmental condition that has a fundamental effect on performance and needs to be taken into account when designing algorithms to be used in real lif

Potential applications of filamentous fungus derived β-defensin-like antifungal proteins in agriculture

Many filamentous fungi are postharvest and destructive plant pathogens and are thus responsible for enormous crop losses worldwide. The antifungal proteins secreted by filamentous fungi are promising agents for prevention of fungal diseases in the agriculture. The extracellular β-defensin-like antifungal proteins derived from ascomycetous filamentous fungal species are especially interesting in this respect because of their chemical and biological properties. The main features of these extracellular proteins are a low molecular mass, a basic character, and the presence of 6-8 cysteine residues and several intramolecular disulfide bonds which provide them with a high stability against protease degradation, high temperature and within a broad pH range. The tertiary structure of these proteins is very similar to the β-defensins, it contains five antiparallel β-sheets connected by three loops. In spite of the fact that they are very different in their amino acid sequences; conserved homologous regions can be identified. Based on it they can be divided into two main groups: peptides which contain the Penicillium chrysogenum antifungal protein (PAF) cluster in their amino acid sequences, and peptides with Penicillium brevicompactum bubble protein (BP) cluster. Both of them have a potent antifungal activity, but the peptides with PAF-cluster are effective against filamentous fungi. These proteins secreted by taxonomical distinct species cause similar symptoms on the susceptible fungus, but they have different mode of action and species specificity, nevertheless, their structure is very similar. They have high stability and efficacy; their limited toxicity and low costs of production could make them suitable for use in practical respects in agricultural fields, especially in plant protection on the field and crop protection after the harvest

Potential applications of filamentous fungus derived β-defensin-like antifungal proteins in agriculture

Many filamentous fungi are postharvest and destructive plant pathogens and are thus responsible for enormous crop losses worldwide. The antifungal proteins secreted by filamentous fungi are promising agents for prevention of fungal diseases in the agriculture. The extracellular β-defensin-like antifungal proteins derived from ascomycetous filamentous fungal species are especially interesting in this respect because of their chemical and biological properties. The main features of these extracellular proteins are a low molecular mass, a basic character, and the presence of 6-8 cysteine residues and several intramolecular disulfide bonds which provide them with a high stability against protease degradation, high temperature and within a broad pH range. The tertiary structure of these proteins is very similar to the β-defensins, it contains five antiparallel β-sheets connected by three loops. In spite of the fact that they are very different in their amino acid sequences; conserved homologous regions can be identified. Based on it they can be divided into two main groups: peptides which contain the Penicillium chrysogenum antifungal protein (PAF) cluster in their amino acid sequences, and peptides with Penicillium brevicompactum bubble protein (BP) cluster. Both of them have a potent antifungal activity, but the peptides with PAF-cluster are effective against filamentous fungi. These proteins secreted by taxonomical distinct species cause similar symptoms on the susceptible fungus, but they have different mode of action and species specificity, nevertheless, their structure is very similar. They have high stability and efficacy; their limited toxicity and low costs of production could make them suitable for use in practical respects in agricultural fields, especially in plant protection on the field and crop protection after the harvest

Confirmation of the Disulfide Connectivity and Strategies for Chemical Synthesis of the Four-Disulfide-Bond-Stabilized Aspergillus giganteus Antifungal Protein, AFP

Emerging fungal infections require new, more efficient antifungal agents and therapies. AFP, a protein from Aspergillus giganteus with four disulfide bonds, is a promising candidate because it selectively inhibits the growth of filamentous fungi. In this work, the reduced form of AFP was prepared using native chemical ligation. The native protein was synthesized via oxidative folding with uniform protection for cysteine thiols. AFP's biological activity depends heavily on the pattern of natural disulfide bonds. Enzymatic digestion and MS analysis provide proof for interlocking disulfide topology (abcdabcd) that was previously assumed. With this knowledge, a semi-orthogonal thiol protection method was designed. By following this strategy, out of a possible 105, only 6 disulfide isomers formed and 1 of them proved to be identical with the native protein. This approach allows the synthesis of analogs for examining structure-activity relationships and, thus, preparing AFP variants with higher antifungal activity

Confirmation of the Disulfide Connectivity and Strategies for Chemical Synthesis of the Four-Disulfide-Bond-Stabilized Aspergillus giganteus Antifungal Protein, AFP

Emerging fungal infections require new, more efficient antifungal agents and therapies. AFP, a protein from Aspergillus giganteus with four disulfide bonds, is a promising candidate because it selectively inhibits the growth of filamentous fungi. In this work, the reduced form of AFP was prepared using native chemical ligation. The native protein was synthesized via oxidative folding with uniform protection for cysteine thiols. AFP's biological activity depends heavily on the pattern of natural disulfide bonds. Enzymatic digestion and MS analysis provide proof for interlocking disulfide topology (abcdabcd) that was previously assumed. With this knowledge, a semi-orthogonal thiol protection method was designed. By following this strategy, out of a possible 105, only 6 disulfide isomers formed and 1 of them proved to be identical with the native protein. This approach allows the synthesis of analogs for examining structure-activity relationships and, thus, preparing AFP variants with higher antifungal activity