Временная составляющая аналитической модели действий диспетчера управления воздушным движением

It has been considered the mathematical apparatus, allowing to find time characteristics of air traffic control dispatcher actions with the interface of an automated workplace of the regional dispatching centre of Uniform system of air movement organisation of Republic of Belarus.Рассмотрен математический аппарат, позволяющий находить временные характеристики действий диспетчера управления воздушным движением с интерфейсом автоматизированного рабочего места районного диспетчерского центра Единой системы организации воздушного движения Республики Беларусь

Влияние микробного препарата БакСиб на озимый ячмень и состояние чернозема южного

In the article, the authors showed the effectiveness of bacterization of winter barley variety Basalt with a complex microbial preparation BakSib. The authors used a semi-dry method of seed treatment (10 l/t of working solution) and a single treatment of vegetative plants on the southern chernozem together with chemical pesticides and without them. After treatment with the drug was observed: 1) a decrease in the number of microscopic fungi in the soil up to 3 times in the tillering phase and by 21% in the full ripeness phase in comparison with the control; 2) an increase in the number of ammonifiers from 44 to 81.4%; 3) an increase in the number of bacteria that assimilate mineral nitrogen from 79 to 116%. The authors revealed the stimulating effect of BakSib on the height of barley plants in all growth phases by 7.9–13.3% compared to the control. The yield of barley increased to 9%, and the number of grains per ear increased by 9.6% compared to the control and by 6.4% when comparing the full technology of plant protection of the farm and additional bacterization with BakSib. The authors also determined the compatibility of BakSib with the insecticide Clothianidin Pro (clothianidin 350 g/l) and the fungicide Sphinx (tebuconazole 60 g/l) for seed dressing. During the study, the authors found that under the action of chemical protectants, the initial titer of the biological product (1010–1012 cells) is reduced by 3-4 times. The maximum decrease noted for individual groups of Baksiba microorganisms is two orders of magnitude. The drug contributed to a prolonged increase in copiotrophic bacteria in the southern chernozem and replenishment of its nitrogen fund during the heading period, which is important for grain productivity due to increased mineralization of organic residues in the soil.Показана эффективность бактеризации озимого ячменя Базальт комплексным микробным препаратом БакСиб полусухим методом обработки семян (10 л/т рабочего раствора) и однократной обработкой вегетирующих растений на черноземе южном совместно с химическими пестицидами и без них. После обработки препаратом наблюдалось снижение численности микроскопических грибов в почве до 3 раз в фазе кущения и на 21% в фазе полной спелости в сравнении с контролем, увеличение числа аммонификаторов от 44 до 81,4%, увеличение численности бактерий, усваивающих минеральный азот, от 79 до 116%. Выявлено стимулирующее действие БакСиба на высоту растений ячменя во все фазы роста на 7,9–13,3% в сравнении с контролем. Урожайность ячменя повысилась до 9%, увеличилось количество зерен в колосе на 9,6% по сравнению с контролем и на 6,4% при сравнении полной технологии защиты растений хозяйства и дополнительной бактеризации препаратом БакСиб. Определена совместимость БакСиба с инсектицидом для протравливания семян Клотианидином Про (клотианидин 350 г/л) и фунгицидом Сфинксом (тебуконазол 60 г/л). Показано, что под действием химических протравителей исходный титр биопрепарата (1010–1012 клеток) снижается в 3–4 раза; максимальное снижение, отмеченное для отдельных групп микроорганизмов БакСиба, составляет два порядка. Препарат способствовал пролонгированному увеличению в черноземе южном копиотрофных бактерий и пополнению ее азотного фонда в важный для зерновой продуктивности период колошения за счет повышенной минерализации органических остатков в почве

Highly specific host-pathogen interactions influence Metarhizium brunneum blastospore virulence against Culex quinquefasciatus larvae

Entomopathogenic fungi are potential biological control agents of mosquitoes. Our group observed that not all mosquitoes were equally susceptible to fungal infection and observed significant differences in virulence of different spore types. Conidiospores and blastospores were tested against Culex quinquefasciatus larvae. Blastospores are normally considered more virulent than conidia as they form germ tubes and penetrate the host integument more rapidly than conidia. However, when tested against Cx. quinquefasciatus, blastospores were less virulent than conidia. This host-fungus interaction was studied by optical, electron and atomic force microscopy (AFM). Furthermore, host immune responses and specific gene expression were investigated. Metarhizium brunneum (formerly M. anisopliae) ARSEF 4556 blastospores did not readily adhere to Culex larval integument and the main route of infection was through the gut. Adhesion forces between blastospores and Culex cuticle were significantly lower than for other insects. Larvae challenged with blastospores showed enhanced immune responses, with increased levels of phenoloxidase, glutathione-S-transferase, esterase, superoxide dismutase and lipid peroxidase activity. Interestingly, M. brunneum pathogenicity/stress-related genes were all down-regulated in blastospores exposed to Culex. Conversely, when conidia were exposed to Culex, the pathogenicity genes involved in adhesion or cuticle degradation were up-regulated. Delayed host mortality following blastospore infection of Culex was probably due to lower adhesion rates of blastospores to the cuticle and enhanced host immune responses deployed to counter infection. The results here show that subtle differences in host-pathogen interactions can be responsible for significant changes in virulence when comparing mosquito species, having important consequences for biological control strategies and the understanding of pathogenicity processes

Creating a tobacco line with a weaker antifeedant property against colorado potato beetle

Background. Genetic modification of plants is one of the promising strategies to increase their resistance to insect pests. The development of metabolic or RNA interference systems for plant protection requires appropriate models of host-insect interactions. Nicotiana tabacum L. is a classical model plant used in molecular and metabolic engineering. We consider tobacco as a model for developing protective strategies against Colorado potato beetle (Leptinotarsa decemlineata Say, CPB). Normally, tobacco is toxic for CPB due to high content of nicotine and related alkaloids in leaves. Modification of the tobacco genome could provide tobacco genotypes with altered metabolism suitable for CPB feeding. It is known that different mutations in Berberine Bridge-Like (BBL) genes cause different alterations in tobacco leaf alkaloid levels. In the current study, the Cas9/gRNA system targeting members of the BBL gene family of tobacco was used to create a line which can serve as a diet for CPB. Results. In order to obtain tobacco with modified alkaloid content, two gRNAs matching target sequences in six BBL genes were selected. Each gRNA was cloned into a gRNA/Cas9 generic vector. The created constructs were mixed and used for biolistic transformation of tobacco leaf explants together with the pBI121 plasmid harboring the kanamycin resistance gene nptII and the reporter E.coli betaglucuronidase (GUS) gene. Regenerants were selected on 100 mg/l of kanamycin and checked for transgene presence by histochemical GUS-assay. Unexpectedly, the regenerated plants displayed a variety of adverse phenotypic effects including different degree of growth and rooting inhibition, early flowering, increased number of internodes, changes in leaf shape, fusion of flowers, longostyly, and partial sterility. Only one from seven obtained calli produced a population of regenerated plants without severe phenotypic abnormalities. The NtaBBL5-14 line of clonally propagated plants was selected from this population and used for a CPB feeding experiment. It was shown that CPB larvae consume the leaves of NtaBBL5-14 line ten times more efficiently than the leaves of control plants (97±0.5% vs. 9±3% in 24 h respectively). Conclusion. The NtaBBL5-14 tobacco line is suitable for CPB feeding and can be further used as a model for studies in plant-pest interaction. The modification of other genes regulating nicotine metabolism can be a promising strategy to obtain tobacco plants edible for CPB with less pleiotropic effects

The insect, Galleria mellonella, is a compatible model for evaluating the toxicology of okadaic acid

The polyether toxin, okadaic acid, causes diarrhetic shellfish poisoning in humans. Despite extensive research into its cellular targets using rodent models, we know little about its putative effect(s) on innate immunity. We inoculated larvae of the greater waxmoth, Galleria mellonella, with physiologically relevant doses of okadaic acid by direct injection into the haemocoel (body cavity) and/or gavage (force-feeding). We monitored larval survival and employed a range of cellular and biochemical assays to assess the potential harmful effects of okadaic acid. Okadaic acid at concentrations >75 ng/larva (>242 µg/kg) led to significant reductions in larval survival (>65%) and circulating haemocyte (blood cell) numbers (>50%) within 24 h post-inoculation. In the haemolymph, okadaic acid reduced haemocyte viability and increased phenoloxidase activities. In the midgut, okadaic acid induced oxidative damage as determined by increases in superoxide dismutase activity and levels of malondialdehyde (i.e., lipid peroxidation). Our observations of insect larvae correspond broadly to data published using rodent models of shellfish poisoning toxidrome, including complementary LD50 values; 206–242 μg/kg in mice, ~239 μg/kg in G. mellonella. These data support the use of this insect as a surrogate model for the investigation of marine toxins, which offers distinct ethical and financial incentives

The time component of analytical model of the air traffic control dispatcher actions

It has been considered the mathematical apparatus, allowing to find time characteristics of air traffic control dispatcher actions with the interface of an automated workplace of the regional dispatching centre of Uniform system of air movement organisation of Republic of Belarus

The effect of silicon dioxide nanoparticles combined with entomopathogenic bacteria or fungus on the survival of Colorado potato beetle and cabbage beetles

Three types of modified silicon dioxide nanoparticles (SiO2, 10-20 nm) with additives of epoxy, silane and amino groups, used independently and in combination with the entomopathogenic bacteria Bacillus thuringiensis subsp. morrisoni and fungus Metarhizium robertsii were tested against Colorado potato beetle (Leptinotarsa decemlineata) and cabbage beetles (Phyllotreta spp.). All three nanoparticles were found to have an entomocidal effect on Colorado potato beetle larvae and crucifer flea beetles when ingested. Increased susceptibility of insects to B. thuringiensis or M. robertsii blastospores and their metabolites was shown after exposure to the modified silicon dioxide nanoparticles. The potential of modified silicon dioxide nanoparticles to enhance the efficiency of biopesticides based on the bacteria B. thuringiensis and fungi M. robertsii is considered in the paper

Original Russian Text ©

It is known that crop plants' induced resistance to phyllophages, which is due to accumulation of secondary metabolites, decreases the viability of phyllophages and changes the sensitivity to entomopathogens It is known that tannins, including tannic acid, can form complexes with proteins; when oxidized to quinones in the midgut of insect, they can produce semiquinone radicals and other forms of reactive oxygen species In view of this, the goal of this study was to investigate the effect of a phenolic compound, tannic acid, on the development of L. dispar and its sensitivity to nuclear polyhedrosis. The ratio between the concentrations of oxidized and reduced thiol-containing compounds in insect midguts-an index reflecting the antioxidant status of the insect-was used as a criterion of the effect of this allelochemical on insect's organism. MATERIALS AND METHODS This study was performed with the gypsy moth ( L. dispar L., Lepidoptera: Lymantridae) caterpillars. The insects were collected at the egg phase in the natural population and then grown under laboratory conditions. The experiments were performed in spring and summer. The insects were grown either in an artificial nutrient medium in Petri dishes or on birch shoots in rearing cages at 23-25 ° C under at 16-h light period per day. Forage was treated with 0.9% aqueous solution of tannic acid (Sigma, United States). This concentration corresponds to the content of tannins in birch leaves defoliated in the previous year Biochemical analysis of the midgut was performed using the fourth-instar caterpillars on the fourth da

<i>Bacillus thuringiensis</i> Spores and Cry3A Toxins Act Synergistically to Expedite Colorado Potato Beetle Mortality

The insect integument (exoskeleton) is an effective physiochemical barrier that limits disease-causing agents to a few portals of entry, including the gastrointestinal and reproductive tracts. The bacterial biopesticide Bacillus thuringiensis (Bt) enters the insect host via the mouth and must thwart gut-based defences to make its way into the body cavity (haemocoel) and establish infection. We sought to uncover the main antibacterial defences of the midgut and the pathophysiological features of Bt in a notable insect pest, the Colorado potato beetle Leptinotarsa decemlineata (CPB). Exposing the beetles to both Bt spores and their Cry3A toxins (crystalline δ-endotoxins) via oral inoculation led to higher mortality levels when compared to either spores or Cry3A toxins alone. Within 12 h post-exposure, Cry3A toxins caused a 1.5-fold increase in the levels of reactive oxygen species (ROS) and malondialdehyde (lipid peroxidation) within the midgut – key indicators of tissue damage. When Cry3A toxins are combined with spores, gross redox imbalance and ‘oxidation stress’ is apparent in beetle larvae. The insect detoxification system is activated when Bt spores and Cry3A toxins are administered alone or in combination to mitigate toxicosis, in addition to elevated mRNA levels of candidate defence genes (pattern-recognition receptor, stress-regulation, serine proteases, and prosaposin-like protein). The presence of bacterial spores and/or Cry3A toxins coincides with subtle changes in microbial community composition of the midgut, such as decreased Pseudomonas abundance at 48 h post inoculation. Both Bt spores and Cry3A toxins have negative impacts on larval health, and when combined, likely cause metabolic derangement, due to multiple tissue targets being compromised