Baculoviruses, especially prevalent in Lepidoptera, have attracted the most attention as biological insect control agents. Infection with baculoviruses is usually fatal and therefore can affect the ...host population density, especially if virus transmission increases with host density. Lepidoptera larvae show a strong dose-dependent response to pathogens such as baculoviruses, so their response to various pathogen exposures was studied in this work. Models of virus exposure to insect hosts are usually judged by whether or not they generate cyclical population dynamics of multiple host generations. However, the existing theoretical models based on systems of differential equations are of little use for practical application due to the large number of variables and free parameters. In this regard, the possibility of using a mathematical model for describing the epizootic
Malacosoma neustria
L. and
Lymantria dispar
L. under the influence of the nuclear polyhedrosis virus is considered. To assess the sensitivity of insects to the effects of baculoviruses, laboratory experiments were carried out on the mortality of caterpillars under various infectious loads. In this paper, we consider the possibility of constructing a model for the lifetime of insects after exposure to baculoviruses as an analog of a second-order phase transition in physical systems and give estimates of the model parameters for two insect species at different titers of baculoviruses and at different ages of caterpillars. The dependence of the parameters of the proposed model on the nuclear polyhedrosis virus strains is shown. The importance of the applied parameters for the organization of forest protection measures is substantiated.
This work is dedicated to discussing the possibilities of describing the dynamics of forest insect outbreaks on different spatial scales. The properties of outbreaks are considered on a microspatial ...scale, where the distribution patterns of individuals across different food sources within the boundaries of a local territory or a stand are analyzed and, on a macrospatial scale, where the focus of the analysis are the indicators of the removal of the photosynthetic apparatus (leaves or needles) over the entire territory of the locus, including primary, secondary, and migratory loci. When analyzing the microspatial distribution of caterpillars on trees within loci on different stages of gradation, the model of the distribution of individuals on fodder trees is used as a second-order stage transition. The macrospatial processes that occur during the outbreak development include, first, the growth of an existing outbreak and the emergence of new connected damaged areas of the forest, and, second, the emergence of new unconnected secondary foci. To characterize the outbreaks, their fractal dimension D and the characteristics of the “viscous fingers” on the border of the outbreaks are used. Remote sensing data are used to calculate these characteristics. The proposed approaches can be used to predict the development of a forest insect outbreak. When constructing and verifying the models, we used data from the Siberian silk moth census and the tree colonization rate in the outbreak zone, as well as the remote sensing data on the areas and shapes of the foci in the districts of Krasnoyarsk krai during an outbreak of the Siberian silk moth
Dendrolimus sibiricus
Tschetv. in 2015–2019.
A
bstract
We consider within QCD collinear factorization the inclusive process
p
+
p
→
h
1
+
h
2
+
X
, where the pair of identified hadrons,
h
1
, h
2
, having large transverse momenta is produced in ...high-energy proton-proton collisions. In particular, we concentrate on the kinematics where the two identified hadrons in the final state are separated by a large interval of rapidity Δ
y
. In this case the (calculable) hard part of the reaction receives large higher order corrections ∼
. We provide a theoretical input for the resummation of such contributions with next-to-leading logarithmic accuracy (NLA) in the BFKL approach. Specifically, we calculate in NLA the vertex (impact-factor) for the inclusive production of the identified hadron. This process has much in common with the widely discussed Mueller-Navelet jets production and can be also used to access the BFKL dynamics at proton colliders. Another application of the obtained identified-hadron vertex could be the NLA BFKL description of inclusive forward hadron production in DIS.
The concentration dependence of a microwave frequency radiation from a solution of a functioning enzyme system (ES) (with the example of cytochrome P450 BM3 (CYP102A1) system during lauric acid (LA) ...hydroxylation) has been studied with a radiothermometric sensor. Registration of the radiation from the enzyme solution has been performed in the frequency range from 3.4 to 4.2 GHz at the enzyme concentrations from 10−10 М to 10−6 М. It has been demonstrated that the catalysis of LA hydroxylation in a reconstituted CYP102A1 system is accompanied by a generation of microwave radiation over the entire range of concentrations studied. It has been found that a transition from a multipulse mode (at nanomolar enzyme concentrations from 10−10М to 10−8М) to a single-pulse mode (at micromolar enzyme concentrations from 10−7М to 10−6М) is observed. This effect is discussed on the basis of assumptions considering possible realization of biomaser-like radiation in the enzyme system. The discovered concentration-based effect of the transition of an unsynchronized pulsed radiation into a synchronized one in ES can further be used in the development of novel methods of noninvasive diagnostics of diseases, in mathematical modeling of the functioning of living systems, and in the development of next-generation quantum computers.
The interactions between trees in a forest are manifested in a decrease in phytomass growth and the weakening and disappearance of some trees. One of the ways to identify the nature of the ...relationship between trees in a forest is to study the current functions of distribution of trees in the stand in terms of height and trunk diameter. In this case, various functions are used for description: gamma function, normal and logarithmically normal functions, Weibull function, etc. To theoretically substantiate the choice of a particular distribution to describe the diameters and heights of trees in a stand, in this paper, it is proposed to use the Gaussian Orthogonal Ensemble (GOE) model used in nuclear physics to describe the distribution of energy levels of atomic nuclei and to characterize interactions in chaotic systems. It is shown that the interactions both in the atomic nucleus and in the forest stand can be described by a general model. To describe the taxation indicators of trees, the characteristics of reciprocal heights and diameters are introduced. The GOE model for the forest stand was verified according to the inventory data. It is shown that the parameters of the normalized GOE model do not depend on the age of the stand.
The results of the micro- and nanostructures investigation of Sm(CoCuFe)5 alloys by means of scanning electron and atomic force microscopy are presented. It was shown that sequential high- and ...low-temperature heat treatments lead to the formation of a homogeneous microstructure with nanoscale compositional heterogeneities. Such a structure provides a coercive filed of up to 32 kOe. The coercivity and remanent magnetization of the samples in the temperature range from 300 to 700 K linearly decrease. The predominant coercivity mechanism in these materials is pinning on nanoscale inhomogeneities with an increased copper concentration. The fractal dimension of the surface of the Sm(CoCuFe)5 alloy metallographic specimen was determined at different stages of heat treatments. The comparative analysis of magnetic properties and microstructure in the framework of fractal geometry was carried out.
Research in the development of new therapeutic agents with a wide spectrum of the antiviral activity and a low ability to develop resistance remains the main dimension in combating the global threat ...to public health. The need for a parenteral form of favipiravir was dictated by the necessity to increase the efficacy of therapy in COVID-19 inpatients. This dosage form has expanded the possibilities of drug therapy in the inpatients, for whom a therapeutic effect acceleration and a high safety profile of the drugs used are especially important.
The aim
of the article is the evaluation of the efficacy and safety of a medicinal product containing favipiravir for the parenteral administration against the background of pathogenetic and symptomatic therapy, in comparison with standard therapy in hospitalized COVID-19 patients.
Materials and methods.
An open, randomized, multicenter comparative study was conducted in 6 research centers in the Russian Federation to evaluate the efficacy and safety of favipiravir, a lyophilisate for the preparation of a concentrate for the infusion solution administrated to the patients hospitalized with COVID-19. Screening procedures and randomization were completed in 217 patients, 209 of which had completed the study in accordance with the protocol.
Results.
Between the study groups, statistically significant differences have been found out, making it possible to consider the hypothesis of the drug Areplivir (favipiravir) superiority for the parenteral administration over the standard therapy, which included favipiravir (p. o.) and remdesivir. A comparative analysis has shown that a course of therapy with the parenteral favipiravir drug leads to a significant improvement in the condition of patients with COVID-19, significant benefits in terms of the speed and frequency of improvement in the clinical status of patients, as well as a reduction in the hospital stay length. It has been proven that therapy with a drug containing favipiravir for the parenteral administration does not adversely affect the parameters of clinical and biochemical blood tests, urinalysis, coagulograms, vital signs and ECG, which indicates the therapy safety. The study drug is characterized by a high safety profile and tolerability.
Conclusion.
The versatility and resistance to mutations of RNA-dependent RNA polymerase make it possible to consider it as the main target for combating the most common RNA viruses that cause ARVI, that determines the need further studies of favipiravir to expand the range of its indications.
Results are presented from an analysis of the nano- and magnetic domain structures of high coercive Sm(CoCuFe)
5
alloy using fractal geometry. Fractal dimension
D
f
of the nano- and domain ...structures are determined at different stages of heat treatment. It is shown that
D
f
~ 2.08 corresponds to the nanostructure of samples with a coercive force of 7 kOe, while
D
f
~ 2.3 corresponds to the nanostructure of samples with a coercive force of 32 kOe.
This article discusses a system for the molecular diagnosis of diseases at the early stages based on biochips using field effect nanotransistors. Practical questions relating to data processing to ...avoid signal distortion are addressed, as well as problems of signal visualization.
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