299 research outputs found

    Past distribution of Tilia-feeding Phyllonorycter micromoth (Lepidoptera: Gracillariidae) in the Russian Far East based on survey of historical herbarium

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    Distribution data of Tilia-feeding Phyllonorycter in the Russian Far East have been retrieved from a century-old Tilia herbarium stored in Vladivostok. Overall, 280 typical mines of Phyllonorycter, some with larvae and pupae, were found on 61 out of 799 herbarized specimens of Tilia spp. collected in Khabarovskii krai and Primorskii krai. For the first time, the presence of Tilia-feeding Phyllonorycter has been documented in Amurskaya oblast and Jewish Autonomous oblast. High densities of the leafminer have been recorded on Tilia amurensis sampled in Khabarovskii krai and Primorskii krai between 1937 and 2005 suggesting a population dynamics with recurrent outbreaks. Our results confirm the importance of historical herbarium collections in studying trophic interactions and invasion ecology of folivore organisms

    Calculation of the greens function of boundary value problems for linear ordinary differential equations

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    The Greens function is widely used in solving boundary value problems for differential equations, to which many mathematical and physical problems are reduced. In particular, solutions of partial differential equations by the Fourier method are reduced to boundary value problems for ordinary differential equations. Lets note that using the Greens function for a homogeneous problem, it is possible to calculate the solution of an inhomogeneous differential equation. Also, using the Greens function, one can solve the problem of finding eigenvalues, which are very relevant in quantum field theor

    Acute otitis externa in children: causes, diagnosis, treatment, clinical report

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    Acute otitis externa is a common disease in the pediatric population, characterized by diffuse inflammation of the external auditory canal. Typical symptoms of acute otitis externa include otology, itching, congestion, and a feeling of fullness in the sore ear. In the case of active inflammation, the process can go to the tympanic membrane, and acute otitis media will join the external one. Primary therapy for diffuse uncomplicated acute otitis externa should include a local antimicrobial drug, without systemic antibiotic therapy. Topical therapy with antibacterial drugs in combination with anesthetics is the most rational. A clinical case of a 12-year-old patient with acute diffuse otitis externa and otitis media with effusion; acute nasopharyngitis; and adenoiditis, which was established based on anamnesis and clinical data is presented. Complex therapy was prescribed, which included local antibiotic therapy with a complex topical drug for the treatment of imperforated otitis externa and imperforated otitis media. At reexamination 5 days later, the patient demonstrated positive dynamics, pain in the left ear was eliminated. In cases of uncomplicated diffuse otitis externa, as well as in cases of its combination with otitis media with effusion, topical antibiotic therapy is a major priority. It should be borne in mind that the topical medication is more effective with the cleansing of the external auditory canal from inflammatory secretion. If it is used correctly, it would provide positive dynamics without systemic antibiotic prescription. It preserves the microbiome and mobilizes the body’s defenses. The application of complex topical antibiotic drugs can be widely recommended in pediatric practice

    Integrating linear ordinary fourthorder differential equations in the MAPLE programming environment

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    This paper reports a method to solve ordinary fourth-order differential equations in the form of ordinary power series and, for the case of regular special points, in the form of generalized power series. An algorithm has been constructed and a program has been developed in the MAPLE environment (Waterloo, Ontario, Canada) in order to solve the fourth-order differential equation

    Zinc oxide-nickel cermet selective coatings obtained by sequential electrodeposition

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    The investigation of pulse electrodepositing modes influence on crystal structure, morphology and optical properties of ZnO has revealed the conditions in which quasi-one-dimensional (1D) ZnO nanorod arrays are formed as separate nanorods. Due to a sufficiently high resistance of zinc oxide, the electrodeposition of nickel on the fluorine doped tin oxide (FTO)/ZnO surfaces carried out in space between the ZnO nanorods. An incomplete filling of the gaps between nanorods by the nickel nanoparticles through subsequent Ni electrodeposition ensured the creation of ZnO–Ni graded cermets. The cermets, in which electrochemical filling of the spaces between ZnO nanorods by Ni, was performed in the pulse mode. It provided higher absorption of visible and near IR light. It was shown that the manufactured ZnO–Ni graded cermets have high light absorption combined with comparatively low thermal losses, so these cermets are promising cheap and affordable selective coatings for solar heat collectors

    GEOCHEMICAL ASSESSMENT OF THE POTENTIALLY TOXIC ELEMENTS BACKGROUND CONTENTS IN SOILS IN THE AREA OF THE SARALA GOLD ORE CLUSTER (THE REPUBLIC OF KHAKASSIA, RUSSIA)

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    We assessed the contents of Fe, Ni, Cu, Zn, As, Cr, Pb, Hg in soils of the residential settlements and surrounding areas exposed to anthropogenic load due to mining activities. The study object is located in the Kuznetsk Alatau (part of the Sarala gold ore cluster – SGOC), the village of Priiskovy and its tailings dump, the village of Ordzhonikidzevsky, the Republic of Khakassia). The background contents in the SGOC soils are the following: Fe 3.08–5.06 %, Ni 24.74–45.13 g/t, Cu 22.33–38.81 g/t, Zn 86.72–200 g/t, As 5.45–11.25 g/t, Cr 35.60–73.25 g/t, Pb 14.12–26.17 g/t, Hg 0.01–0.14 g/t. It was found that the background area has increased the natural contents of the studied elements. The soils sampled from the territory of the tailing dump are distinguished by the elevated element contents relative to the background values and especially by a sharp jump of the As and Zn contents (abnormal contents). The contents of all the elements examined in the soils of the territories in the vicinity of the tailing dump also exceed the background values of the SGOC with different proportions of cases and have the increased As, Cr, and Pb contents relative to the maximum permissible concentration of soils. Clustering of the data shows the presence of two clusters, which indicate the availability of the background and anomalous values associated with the technogenic impact of the mining industry in the study area of the Sarala gold ore cluster
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