143 results on '"Alexander Konstantinov"'
Search Results
2. Palaearctic flea beetle Phyllotreta ochripes (Curtis) (Coleoptera, Chrysomelidae, Galerucinae), herbivore of Alliaria petiolata (garlic mustard), new to North America
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Hume Douglas, George Hammond, Tyler Smith, Jessie Mutz, and Alexander Konstantinov
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invasive alien species ,adventive species ,biologi ,Biology (General) ,QH301-705.5 - Abstract
The univoltine leaf beetle Phyllotreta ochripes (Curtis, 1837b) is native to the Palaearctic Region from Japan to western Europe.This species was previously evaluated as a potential biological control agent against invasive populations of the woodland weed Alliaria petiolata (Bieb.) Cavara & Grande (Brassicaceae) in North America, but rejected because it could harm native and at-risk populations of Brassicaceae.First North American records are presented for Phyllotreta ochripes (Curtis, 1837). Specimens were examined from the USA: Illinois, Maryland, Michigan, Ohio and Pennsylvania. Internet photographs of apparent additional individuals from USA: Indiana, Michigan, Minnesota, Ohio, Pennsylvania, Tennessee, Wisconsin and Canada: Ontario were also examined. DNA barcoding analysis showed high genetic variability and possible cryptic species within European populations of P. ochripes. Diagnostic information is presented to distinguish P. ochripes. from other North American Chrysomelidae and a species distribution model to assess its potential spread in North America is presented.Phyllotreta ochripes breeds on invasive garlic mustard, Alliaria petiolata (Bieb.) Cavara & Grande (Brassicaceae) and also non-native Rorippa amphibia (L.) Besser and other species of Brassicaceae.A species distribution model and the range of its host plant A. petiolata, indicates the most suitable conditions for this species are in humid areas of eastern North America. However, most of the known records of this species were discovered in areas projected to have low suitability. This is likely a consequence of sampling bias towards western Europe and away from the eastern Asian portion of its native range. The United States of America and Canada are now known to be home to 72 or more species of adventive Chrysomelidae.
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- 2024
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3. Palearctic flea beetle and pest of hops and Cannabis, Psylliodes attenuata (Coleoptera, Chrysomelidae, Galerucinae), new to North America
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Hume Douglas, Justin Renkema, Tyler Smith, Alexander Konstantinov, and Joseph Moisan-De Serres
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invasive alien species ,adventive species ,crop pe ,Biology (General) ,QH301-705.5 - Abstract
The univoltine leaf beetle Psylliodes attenuata (Koch, 1803) is a pest of Cannabis and Humulus (Cannabaceae) and native to the Palaearctic Region, known from eastern Asia to western Europe.First North American records are presented for P. attenuata from Canada: Ontario and Québec. Adult beetle feeding damage to hops Humulus lupulus L. (Cannabacaea) plants is recorded from Québec. Diagnostic information is presented to distinguish P. attenuata from other North American Chrysomelidae and a preliminary assessment of its potential to spread in North America is presented. While our climate analysis is limited by a lack of data, it appears P. attenuata is physiologically capable of persisting throughout the range of Humulus in North America.The United States of America and Canada are now known to be home to 71 or more species of adventive Chrysomelidae.
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- 2024
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4. Findings from Lomonosov Moscow State University in Biochemistry Reported (The Mechanisms of Electrogenic Reactions In Bacterial Photosynthetic Reaction Centers: Studies In Collaboration With Alexander Konstantinov)
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Biochemistry ,Photosynthesis ,Biological sciences ,Health - Abstract
2021 MAR 9 (NewsRx) -- By a News Reporter-Staff News Editor at Life Science Weekly -- Investigators discuss new findings in Life Science Research - Biochemistry. According to news reporting [...]
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- 2021
5. Fabrician types of new world Oedionychina Chapuis, 1875 (Coleoptera, Chrysomelidae, Alticini) deposited in the Zoological Museum of Kiel University collections with notes on Fabrician types of other collections and new combinations for species formerly pl
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Martijn Van Roie, Michael Kuhlmann, Anne Mack, and Alexander Konstantinov
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type specimens ,lectotype designation ,nomenclature ,new combinations ,new status ,Zoology ,QL1-991 ,Botany ,QK1-989 - Abstract
Type specimens of Oedionychina Chapuis, 1875 described by Fabricius from the Kiel collection are examined and illustrated. Lectotypes are designated for the following species: Chrysomela albicollis Fabricius, 1787; Chrysomela nobilitata Fabricius, 1787; Chrysomela quadrifasciata Fabricius, 1787; Chrysomela quadriguttata Fabricius, 1781; Galleruca atomaria Fabricius, 1801; Galleruca decemguttata Fabricius, 1801; Galleruca fasciata Fabricius, 1798; Galleruca humeralis Fabricius, 1801; Galleruca lunata Fabricius, 1801; Galleruca nitida Fabricius, 1801; Galleruca obsoleta Fabricius, 1801; Galleruca petaurista Fabricius, 1801; Galleruca quadrinotata Fabricius, 1798; Galleruca sellata Fabricius, 1801. The species status is restored for Chrysomela quadriguttata Fabricius, 1781 and Alagoasa areata (Germar, 1824) comb. nov. The following new combinations are proposed: Phenrica quadriguttata (Fabricius, 1781), Asphaera nitida (Fabricius, 1801), Phenrica obsoleta (Fabricius, 1801), Alagoasa areata areata (Germar, 1824), Alagoasa areata decempunctata (Latreille, 1833), Alagoasa areata escuintla Bechyné, 1955, Alagoasa areata macromela Bechyné, 1958, Alagoasa areata praecessa Bechyné, 1959, Alagoasa areata recuperata Bechyné, 1959; all comb. nov. New placement: Galleruca avicenniae Fabricius, 1792 is removed from Alticini and placed in Galerucini incertae sedis; Galleruca trifasciata Fabricius, 1801 is removed from Chrysomelidae and placed in genus Ora Clark, 1865 (Scirtidae Fleming, 1821).
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- 2024
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6. Compactability Regularities Observed during Cold Uniaxial Pressing of Layered Powder Green Samples Based on Ti-Al-Nb-Mo-B and Ti-B
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Pavel Bazhin, Alexander Konstantinov, Andrey Chizhikov, Mikhail Antipov, Pavel Stolin, Varvara Avdeeva, and Anna Antonenkova
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compactability ,rheological regularities ,cold uniaxial pressing ,layered composite materials ,powder green samples ,TNM ,Mining engineering. Metallurgy ,TN1-997 - Abstract
We determined the compactability regularities observed during the cold uniaxial pressing of layered powder green samples, taking into account factors such as composition, height, and number of Ti–B (TiB) and Ti–Al–Nb–Mo–B (TNM) layers. The following composition was chosen for the TNM layer at %: 51.85Ti–43Al–4Nb–1Mo–0.15B, while for the Ti-B layer we selected the composition wt %: Ti-B-(20, 30, 40) Ti. Green samples were made containing both 100 vol % TiB and TNM, and those taken in the following proportions, vol %: 70TiB/30TNM, 50TiB/50TNM, 30TiB/70TNM; multilayer green samples were studied in the following proportions, vol %: 35TiB/30TNM/35TiB, 25TiB/25TNM/25TiB/25TNM, 35TNM/30TiB/35TNM. Based on the obtained rheological data, we determined the rheological characteristics of the layered green samples, including compressibility modulus, compressibility coefficient, relaxation time, and limiting value of linear section deformation. These characteristics were found to vary depending on the composition, height, and number of layers. Our findings revealed that reducing the TNM content in the charge billet composition improves the compaction of powder materials under the given technological parameters of uniaxial cold pressing. Moreover, we observed that increasing the boron content and decreasing the amount of titanium in the Ti–B composition enhances the compactability of powder materials. We also established a relationship between the compaction pressure interval and the density of the layered powder green sample.
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- 2023
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7. Influence of Layer-Thickness Proportions and Their Strength and Elastic Properties on Stress Redistribution during Three-Point Bending of TiB/Ti-Based Two-Layer Ceramics Composites
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Kirill Khvostunkov, Pavel Bazhin, Qing-Qing Ni, Arina Bazhina, Andrey Chizhikov, and Alexander Konstantinov
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two-layer composite ,cermet ,mathematical model ,stress redistribution ,flexural strength ,SHS ,Mining engineering. Metallurgy ,TN1-997 - Abstract
A mathematical model was developed to determine the order of failure of layers in a two-layer ceramics composite and to determine the conditions for achieving the maximum limit load under three-point loading. The model was set in the space of three “bilayer parameters”: the ratio of the thickness of the lower layer to the whole thickness of the beam, the ratio of Young’s moduli of the lower layer to the upper layer, and the ratio of flexural strengths of the materials of the lower layer to the upper layer. The adequacy of the model obtained was confirmed by experimental results on the three-point bending of the experimental specimens. The experimental samples were two-layer composites consisting of a cermet layer TiB/Ti and a layer of α-Ti. The samples were obtained by free self-propagating high-temperature synthesis (SHS) compression and with varying their thickness. The results obtained make it possible to predict in advance which layer, based on the specific bilayer parameters, will trigger the brittle fracture mechanism as well as to set the maximum destructive load of bilayer composites.
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- 2023
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8. Enhancing DNA barcode reference libraries by harvesting terrestrial arthropods at the Smithsonian's National Museum of Natural History
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Bernardo Santos, Meredith Miller, Margarita Miklasevskaja, Jaclyn McKeown, Niamh Redmond, Jonathan Coddington, Jessica Bird, Scott Miller, Ashton Smith, Seán Brady, Matthew Buffington, M. Lourdes Chamorro, Torsten Dikow, Michael Gates, Paul Goldstein, Alexander Konstantinov, Robert Kula, Nicholas Silverson, M. Alma Solis, Stephanie deWaard, Suresh Naik, Nadya Nikolova, Mikko Pentinsaari, Sean Prosser, Jayme Sones, Evgeny Zakharov, and Jeremy deWaard
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COI ,cox1 ,dark taxa ,OTUs ,BINs ,natural history ,Biology (General) ,QH301-705.5 - Abstract
The use of DNA barcoding has revolutionised biodiversity science, but its application depends on the existence of comprehensive and reliable reference libraries. For many poorly known taxa, such reference sequences are missing even at higher-level taxonomic scales. We harvested the collections of the Smithsonian’s National Museum of Natural History (USNM) to generate DNA barcoding sequences for genera of terrestrial arthropods previously not recorded in one or more major public sequence databases. Our workflow used a mix of Sanger and Next-Generation Sequencing (NGS) approaches to maximise sequence recovery while ensuring affordable cost. In total, COI sequences were obtained for 5,686 specimens belonging to 3,737 determined species in 3,886 genera and 205 families distributed in 137 countries. Success rates varied widely according to collection data and focal taxon. NGS helped recover sequences of specimens that failed a previous run of Sanger sequencing. Success rates and the optimal balance between Sanger and NGS are the most important drivers to maximise output and minimise cost in future projects. The corresponding sequence and taxonomic data can be accessed through the Barcode of Life Data System, GenBank, the Global Biodiversity Information Facility, the Global Genome Biodiversity Network Data Portal and the NMNH data portal.
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- 2023
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9. Land-Use Changes on Ob River Floodplain (Western Siberia, Russia) in Context of Natural and Social Changes over Past 200 Years
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Vladimir Ivanov, Ivan Milyaev, Alexander Konstantinov, and Sergey Loiko
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landscape dynamics ,historical ecology ,historical land-use maps ,GIS ,rural depopulation ,fallow grasslands ,Agriculture - Abstract
Over the past century, substantial changes in land use have taken place in the boreal zone of northern Eurasia. The consequences of these large-scale changes for the ecosystems of Europe have been well studied; however, they have not been addressed for the large expanses of Russia. We conducted a retrospective analysis of the landscape dynamics of the middle reaches of the Ob floodplain (Western Siberia) using multitemporal maps of the vegetation cover and land use for five time points (1830, 1910, 1950, 1976, and 2019). By the 1830s, all the land that was suitable for haymaking and plowing (rarely flooded and not swamped) had been put to agricultural use. The meadows of the Ob floodplain are human-controlled and were mainly formed before the 1830s. From the 1830s to the 1990s, the meadows were used in agriculture and their areas increased. The maximum development of the floodplain occurred in the 1970s and 1980s, when previous wetlands were put into operation through the construction of drainage systems. A massive abandonment of pastures and reclaimed land occurred in the late 20th century. According to the data over the last 30 years, abandoned meadows are resistant to overgrowth with trees and shrubs. The spatial configurations of the floodplain landscapes have also been quite stable. The main spatial changes are confined to the near-channel floodplain, with the formation of new near-channel shallows. The floodplain landscapes of the Ob River demonstrate substantial spatial and temporal stabilities, and long-standing agricultural development.
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- 2022
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10. Mechanical Activation of Smectite-Based Nanocomposites for Creation of Smart Fertilizers
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Maxim Rudmin, Santanu Banerjee, Boris Makarov, Kanipa Ibraeva, and Alexander Konstantinov
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smectite ,urea ,fertilizer nanocomposite ,mechanical activation ,controlled release fertilizer ,nitrogen fertilizer ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
This research presents the mechanical creation of smart fertilizers from a mixture of smectite and urea in a 3:2 ratio by using the planetary milling technique. The smectite–urea composites show intercalation between urea and mineral, which increases steadily with increasing activation time. A shift of X-Ray Diffraction basal reflections, intensities of Fourier transform infrared spectroscopy (FTIR) peaks, and weight losses in thermogravimetric analysis (TG) document the systematic crystallo-chemical changes of the composites related to nitrogen interaction with activation. Observations of the nanocomposites by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) corroborate the inference. Nitrogen intercalates with smectite in the interlayer space and remains absorbed either within micro-aggregates or on the surface of activated smectites. Soil leaching tests reveal a slower rate of nitrogen than that of traditional urea fertilizers. Different forms of nitrogen within the composites cause their differential release rates to the soil. The formulated nanocomposite fertilizer enhances the quality and quantity of oat yield.
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- 2022
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11. Strain Rate Dependencies and Competitive Effects of Dynamic Strength of Some Engineering Materials
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Ivan Smirnov and Alexander Konstantinov
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strength ,dynamic loading ,strain rate sensitivity ,strength competition effect ,incubation time ,structural time criteria ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Comparison of strength characteristics of engineering materials is usually based on comparison of data from quasi-static tests. However, under dynamic loads, strength characteristics of materials are unstable and the strength ratio of two materials can change dramatically. This paper presents a comparative study of the strain/stress rate dependencies of the critical stresses of various quasi-brittle and ductile engineering materials, as well as their various internal states. A case of continuously increasing load in compression and splitting tests is considered. Experimental results were obtained for bricks, mortar and limestone in dry, saturated and frozen states; copper and titanium in different structural states; and road bitumens with different modifiers. The results show that such dependencies can intersect, thereby realizing a strength competition effect. This means that one material can withstand higher stresses under a quasi-static load and lower stresses under a dynamic load in comparison with another material. Thus, such an intersection suggests that the choice of a material based on quasi-static parameters may be erroneous for structures intended for dynamic modes. The analysis of strain/stress rate dependencies of ultimate or yield strength is carried out on the basis of the incubation time approach. The introduction of dynamic strength characteristics with the dimension of time is considered. This parameter characterizes well the response of the materials to dynamic loading. The calculation results show the possibility of estimating the critical stresses and the strength competition effect at high rate loads using no more than three parameters, which can be easily used in engineering practice.
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- 2020
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12. Dos especies nuevas del género Bubiscus (Coleoptera, Chrysomelidae, Alticinae) de Ecuador
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Vilma Savini, Luis José Joly, and Alexander Konstantinov
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Clave ,Neotrópico ,Especies nuevas ,Buviscus voseri Savini et al. (2009) ,Bubiscus carinatus sp. nov. ,Bubiscus napo sp. nov ,Zoology ,QL1-991 - Abstract
El género Busbiscus fue descrito por Savini et al. 2009 en base a la especie B. voseri de Costa Rica. Se describen dos especies nuevas, Bubiscus carinatus y Bubiscus napo provenientes de Ecuador y se incluye una clave de identificación para las tres especies descritas del género.
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- 2015
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13. Revision of the Chaetocnema picipes species-group (Coleoptera, Chrysomelidae, Galerucinae, Alticini) in China, with descriptions of three new species
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Yong-Ying Ruan, Alexander Konstantinov, Si-Qin Ge, and Xing-Ke Yang
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Zoology ,QL1-991 - Abstract
The Chinese Chaetocnema picipes species-group is revised. It contains 5 species including 3 new species: C. cheni sp. n., C. constricta sp. n. and C. kingpinensis sp. n. The lectotype of C. fortecostata is designated. A key to all known species of this group from China and the illustrations of habitus and genitalia are provided. A distribution map of species is given.
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- 2014
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14. First record of leaf-hole shelters used and modified by leaf beetles (Coleoptera, Chrysomelidae), with descriptions of two new Orthaltica Crotch species from southern India
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Kaniyarikkal Prathapan, Alexander Konstantinov, K. Shameem, and A.P. Balan
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Zoology ,QL1-991 - Abstract
Behavioural novelties observed in adult leaf beetles of two new Orthaltica Crotch species include: 1) the use of low cost leaf-hole shelters, either in pre-formed holes produced by larger beetles that fed on the same leaf, or artificially created holes as part of an experiment; and 2) the use of faeces to partition the hole. Two new southern Indian species of the genus Orthaltica are described and illustrated: O. syzygium and O. terminalia. Host plants are identified for both species. A key to the Indian species of Orthaltica is provided.
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- 2013
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15. Role of sorbents in early growth of barley under copper and benzo(a)pyrene contaminated soils
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Anatoly BARAKHOV, Natalia CHERNİKOVA, Tamara DUDNİKOVA, Andrey BARBASHEV, Svetlana SUSHKOVA, Saglara MANDZHİEVA, Vishnu D RAJPUT, Rıdvan KIZILKAYA, Elizabeth KONSTANTİNOVA, Dmitry BREN, Tatiana MİNKİNA, and Alexander KONSTANTİNOV
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Heavy metals ,polycyclic aromatic hydrocarbons ,remediation ,sorbents ,biochar ,germination energy ,Fen ,Science ,Soil Science ,Plant Science ,Environmental Science (miscellaneous) ,Agronomy and Crop Science - Abstract
In modern economic and industrial realities, agricultural lands are often located next to industrial areas, which leads to soil contamination and, as a result, agricultural products with pollutants. Pollution of soils and plants by several pollutants of various nature has acquired huge proportions. There is a threat of migration of dangerous ecotoxicants, including heavy metals and benz[a]pyrene, one of the main persistent compounds, a marker of PAH soil contamination, along trophic chains that may be dangerous to public health. This study examines the use of various types of mineral sorbents (Tripoli, Brown coal, Diatomite) and mineral sorbents (Biochar, Granular activated coal) to reduce the toxic effects of pollutants on the sources of anthropogenic emissions of heavy metals and polycyclic aromatic hydrocarbons adjacent to the sources. Using scanning electron microscopy, it was found that the sorbents have a high specific surface area. With the help of phytotesting in combined contaminated soils, the optimal dose of sorbent administration was determined at the level of 1% and 2% for various pollution variants. In addition, the analyzed sorbents are ordered by the effect of reducing the phytotoxicity of combined soil pollution. It was found that the introduction of sorbents into contaminated soil contributed to an increase in the morphometric parameters of the test culture - barley (Hordeum sativum distichum), which confirms the effectiveness of the sorption remediation of jointly contaminated soils with heavy metals and benz(a)pyrene.
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- 2022
16. New genus and species of flea beetles (Coleoptera, Chrysomelidae, Galerucinae, Alticini) from Puerto Rico, with comments on flea beetle diversity in the West Indies and a key to the West Indian Monoplatini genera
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Alexander Konstantinov and Anna Konstantinova
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Zoology ,QL1-991 - Abstract
A new genus (Borinken) and five new species (Borinken elyunque, Distigmoptera chamorrae, Kiskeya elyunque, Ulrica eltoro, and U. iviei) from Puerto Rico are described and illustrated. A key to all West Indian Monoplatini genera is provided, as are keys to all species of Kiskeya and to the species of Ulrica from Puerto Rico. A list of the flea beetle genera, along with the number of species and some of the faunal features is presented and discussed for the West Indies.
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- 2011
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17. Review of the continental Oriental species of Lilioceris Reitter (Coleoptera, Chrysomelidae, Criocerinae) closely related to Lilioceris impressa (F.)
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Alexey Tishechkin, Alexander Konstantinov, Sanjay Bista, Robert Pemberton, and Ted Center
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Coleoptera ,Chrysomelidae ,Criocerinae ,Lilioceris ,key ,Oriental Region ,new synonyms ,Dioscorea bulbifera ,air potato ,biology ,Lilioceris cheni ,Zoology ,QL1-991 - Abstract
Criocerine leaf beetles found in Nepal feeding on Dioscorea bulbifera (L.), an exotic, invasive weed of Asian origin, were identified as Lilioceris cheni Gressitt and Kimoto based on a synopsis of the Oriental Lilioceris species and review of the Lilioceris impressa species group. All the continental, Oriental species included in the group are diagnosed and illustrated, and a key for their identification is provided. Species status of Lilioceris thibetana Pic, 1916 is resurrected. The following new synonyms are proposed: L. coomani (Pic, 1928) = L. egena (Weise, 1922), and L. subcostata (Pic, 1921a), L. laticornis (Gressit, 1942), L. inflaticornis Gressit and Kimoto, 1961, and L. maai Gressit and Kimoto, 1961 = L. impressa (Fabricius, 1787). Lectotypes of the following species are designated: L. coomani Pic, 1928; L. impressa (Fabricius, 1787); L. laosensis (Pic, 1916); L. malabarica (Jacoby, 1904); L. ruficornis (Pic, 1921b); L. subcostata (Pic, 1921a); L. thibetana (Pic, 1916); and L. unicolor (Hope, 1831).
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- 2011
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18. Cachiporrini, a remarkable new tribe of Lamprosomatinae (Coleoptera, Chrysomelidae) from South America
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Maria Chamorro and Alexander Konstantinov
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Zoology ,QL1-991 - Abstract
A new genus and species of Lamprosomatinae, Cachiporra extremaglobosa Chamorro & Konstantinov, is described from Brazil. A new tribe, Cachiporrini, is proposed. The first phylogenetic analysis of Lamprosomatinae based on adult morphological caharacters is conducted. Comparisons are made among lamprosomatine tribes and genera. A key to tribes is provided.
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- 2011
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19. Synopsis of warty leaf beetle genera of the world (Coleoptera, Chrysomelidae, Cryptocephalinae, Chlamisini)
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Maria Chamorro-Lacayo and Alexander Konstantinov
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Zoology ,QL1-991 - Abstract
The world genera of Chlamisini are reviewed, diagnosed, and illustrated. A key for their identification is provided. A replacement name is proposed, Kakita Chamorro-Lacayo & Konstantinov, nom. n., for Ceratochlamys Bokermann, 1961, a junior homonym of Ceratochlamys Habe, 1946 (Mollusca). Chlamisus rousei Medvedev, 1993 is designated as a junior synonym of Chlamisus straminea Suffrian, 1866, syn. n.
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- 2009
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20. Comparative analysis of dynamic strength and impact toughness of pipe steels
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Anatoly M. Bragov, Alexander Konstantinov, Andrey K. Lomunov, and Leopold Kruszka
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Stress (mechanics) ,Materials science ,Brittleness ,Tension (physics) ,Physics ,QC1-999 ,Charpy impact test ,Fracture (geology) ,Strain rate ,Plasticity ,Composite material ,Ductility - Abstract
To study the dynamic strength of pipe steels, a cycle of dynamic tests of three grades of pipeline steels (X80, X90, and X100) was performed, which included three types of experiments based on the Kolsky method: uniaxial tension of smooth specimens, as well as tension of specimens with a V-shaped annular notch and Charpy impact test according to the three-point bending pattern of beam-type specimens with a V-notch. In the last two cases, the fracture force and impact toughness, as well as the nominal fracture stress in the specimen, were determined. To assess the effect of “cold brittleness” and determine the temperature of the ductile-brittle transition, the specified test cycle was carried out in the temperature range from +20°C to –100°C. As shown by the test results, the studied steels have a fairly high ductility: the elongation at break is 25-30%. Therefore, the destruction of specimens directly in the first load cycle is not always possible. The use of an original system for registering additional loading cycles makes it possible to determine in which loading cycle the specimen ruptured. The limiting characteristics of plasticity (ψ and δ) of all tested steel grades are weakly dependent on both the strain rate and temperature (within the range of their variation). Whereas the impact toughness of steels significantly (2-3 times) decreases with a decrease in temperatures from room temperature to –100°C.
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- 2021
21. Mechanical Response Change in Fine Grain Concrete Under High Strain and Stress Rates
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D. A. Lamzin, Anatoly M. Bragov, Bilen Emek Abali, Andrey K. Lomunov, Alexander Konstantinov, Leonid A. Igumnov, Francesco dell’Isola, Research Institute for Mechanics, National Research Lobachevsky State University of Nizhny Novgorod Russian Federation, and Technische Universität Berlin (TU)
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Fine grain ,Materials science ,Strain (chemistry) ,0211 other engineering and technologies ,Kolsky method ,02 engineering and technology ,[PHYS.MECA]Physics [physics]/Mechanics [physics] ,Strain rate ,Reinforced concrete ,Dynamic increase factor (DIF) ,Fine grain concrete ,Stress (mechanics) ,High strain ,020303 mechanical engineering & transports ,0203 mechanical engineering ,021105 building & construction ,Composite material ,Experiments - Abstract
International audience; Experimental results on assessing the effects of strain and stress rates on the behavior of fine-grain concretes are presented. Specimens of fine-grain and fiberreinforced concretes were dynamically tested using the Kolsky method and its modification, the “Brazilian test”. As a result of the experiments, values of the Dynamic Increase Factor (DIF) were determined for both the materials studied. Their curves as a function of strain and stress rates were constructed. The experimental data is compared with the theoretically obtained values of DIF as a function of strain rate available in the literature
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- 2019
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22. Creation of database for strength calculation of constructions
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Anatoly M. Bragov, Andrey K. Lomunov, Alexander Konstantinov, Sergey Kapustin, and Sergey Isaev
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Database ,Computer science ,Physics ,QC1-999 ,05 social sciences ,050109 social psychology ,0501 psychology and cognitive sciences ,computer.software_genre ,computer - Abstract
The problems of creation of an automated system for obtaining, processing and storing experimental information on the physical and mechanical properties of structural materials, building materials and various soil media used to provide information support for automated computing systems for analysis of strength and design of structures are discussed. The developed database is focused on studying the effects of the behavior of structural materials under highly parametric influences of force, temperature and other physical fields, as well as on equipping and experimental substantiation of mathematical models describing these effects. In the proposed variant, the database is implemented as a client-server application executed on the Microsoft.Net Framework using a powerful database management system MS SQL Server. The content of the created bank is made up of sections of primary information, material properties and material models. In order to automate the processing of data at all stages of information conversion, a special “Desktop” subsystem is included in the bank, which allows aggregating data obtained from several different experiments, correcting the selected data, processing and converting it. Processing and transformation of data in the subsystem “Desktop” can be carried out either in manual mode or on the basis of special algorithms using appropriate mathematical methods.
- Published
- 2018
23. Investigation of strength properties of freshwater ice
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A. R. Filippov, R. A. Didenko, Yu. N. Shmotin, Anatoly M. Bragov, Andrey K. Lomunov, and A. Krundaeva, Leonid A. Igumnov, and Alexander Konstantinov
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Freshwater ice ,Materials science ,Compressive strength ,Dynamic strength ,Shear (geology) ,Physics ,QC1-999 ,Split-Hopkinson pressure bar ,Composite material ,Strain rate ,Engineering physics - Abstract
A study of the strength and deformation properties of freshwater ice under compression, tension and shear in a wide range of strain rates (10−4 − 3 ⋅ 103 s−1 ) and temperatures of − 5∘ C, − 20∘ C, − 40∘ C and − 60∘ C was performed. Static stress-strain curves of ice under compression were obtained on which the identified strength properties of ice as well as compressive modulus. To determine the mechanical properties of ice at high-speed loading the Kolsky method was used with various embodiments of split Hopkinson bar. The deformation curves were obtained at various loading conditions. Thereon breaking points were defined as well as their dependence on the strain rate and temperature. Also static and dynamic strength properties of ice at splitting and circular shear were defined. Increase in the dynamic strength properties upon the static ones for all loading conditions was marked.
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- 2015
24. Mechanical characterization of rocks at high strain rate
- Author
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Matteo Dotta, Daniele Forni, Anatoly M. Bragov, Ezio Cadoni, Alexander Konstantinov, and Andrey K. Lomunov
- Subjects
Physics ,Joint research ,High strain rate ,Tension (geology) ,QC1-999 ,Geotechnical engineering ,Split-Hopkinson pressure bar ,Compression (physics) ,Experimental research ,Characterization (materials science) ,Gneiss - Abstract
The paper presents the dynamic characterization in tension and compression of three rocks, Carrara marble, Onsernone gneiss and Peccia Marble, at high strain-rates. Two versions of a Split Hopkinson Bar have been used. The version for direct tension tests is installed at the DynaMat Laboratory of the University of Applied Sciences of Southern Switzerland, while the traditional version in compression is installed at the Laboratory of Dynamic Investigation of Materials of Lobachevsky State University. Results of the tests show a significantly strain-rate sensitive behaviour, exhibiting dynamic strength increasing with strain-rate. The experimental research has been developed in the frame of the Swiss-Russian Joint Research Program.
- Published
- 2012
25. Toulouse
- Author
-
Mudge, Stephen
- Subjects
Boris Godunov (Opera) -- Pezzino, Leonard -- Gelakhova, Irina -- Toczyska, Stefania -- Afanasenko, Viktor -- Ulyanov, Dmitry -- Anissimov, Alexander -- Konstantinov, Julian -- Langridge, Philip -- Kontarsky, Bernhard -- Mussorgsky, Modest -- Opera reviews ,Operas -- Opera reviews ,Arts, visual and performing ,Music - Abstract
In a year that will see a fair number of performances of Mussorgsky's Boris Godunov across France, the Theatre du Capitole in Toulouse kicked off the proceedings with a fine [...]
- Published
- 2005
26. Resurrection of Sphaenothecus cylindricollis (Casey, 1924), former synonym of Sphaenothecus bilineatus (Gory, 1831) (Coleoptera: Cerambycidae: Cerambycinae: Trachyderini).
- Author
-
LINGAFELTER, STEVEN W.
- Subjects
CERAMBYCIDAE ,SYNONYMS - Abstract
Spring-active Arizona specimens identified as Sphaenothecus bilineatus (Gory, 1831) were determined to represent another species, S. cylindricollis (Casey, 1924), which had been a synonym and is herein reinstated as a valid species. A diagnosis of S. cylindricollis is presented with morphological characters photographed, discussed, and compared to S. bilineatus. Specimen label data from institutional and private collections are provided for S. cylindricollis. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. Compactability Regularities Observed during Cold Uniaxial Pressing of Layered Powder Green Samples Based on Ti-Al-Nb-Mo-B and Ti-B.
- Author
-
Bazhin, Pavel, Konstantinov, Alexander, Chizhikov, Andrey, Antipov, Mikhail, Stolin, Pavel, Avdeeva, Varvara, and Antonenkova, Anna
- Subjects
COMPRESSIBILITY ,COMPACTING ,POWDERS ,COMPOSITE materials - Abstract
We determined the compactability regularities observed during the cold uniaxial pressing of layered powder green samples, taking into account factors such as composition, height, and number of Ti–B (TiB) and Ti–Al–Nb–Mo–B (TNM) layers. The following composition was chosen for the TNM layer at %: 51.85Ti–43Al–4Nb–1Mo–0.15B, while for the Ti-B layer we selected the composition wt %: Ti-B-(20, 30, 40) Ti. Green samples were made containing both 100 vol % TiB and TNM, and those taken in the following proportions, vol %: 70TiB/30TNM, 50TiB/50TNM, 30TiB/70TNM; multilayer green samples were studied in the following proportions, vol %: 35TiB/30TNM/35TiB, 25TiB/25TNM/25TiB/25TNM, 35TNM/30TiB/35TNM. Based on the obtained rheological data, we determined the rheological characteristics of the layered green samples, including compressibility modulus, compressibility coefficient, relaxation time, and limiting value of linear section deformation. These characteristics were found to vary depending on the composition, height, and number of layers. Our findings revealed that reducing the TNM content in the charge billet composition improves the compaction of powder materials under the given technological parameters of uniaxial cold pressing. Moreover, we observed that increasing the boron content and decreasing the amount of titanium in the Ti–B composition enhances the compactability of powder materials. We also established a relationship between the compaction pressure interval and the density of the layered powder green sample. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
28. Generation of Electric Potential Difference by Chromatophores from Photosynthetic Bacteria in the Presence of Trehalose under Continuous Illumination.
- Author
-
Vitukhnovskaya, Liya A., Zaspa, Andrei A., and Mamedov, Mahir D.
- Subjects
VOLTAGE ,PHOTOSYNTHETIC bacteria ,CHROMATOPHORES ,TREHALOSE ,RHODOBACTER sphaeroides ,MEMBRANE filters ,BIOACTIVE glasses ,BILAYER lipid membranes - Abstract
Measurement of electrical potential difference (Δψ) in membrane vesicles (chromatophores) from the purple bacterium Rhodobacter sphaeroides associated with the surface of a nitrocellulose membrane filter (MF) impregnated with a phospholipid solution in decane or immersed into it in the presence of exogenous mediators and disaccharide trehalose demonstrated an increase in the amplitude and stabilization of the signal under continuous illumination. The mediators were the ascorbate/N,N,N′N′-tetramethyl-p-phenylenediamine pair and ubiquinone-0 (electron donor and acceptor, respectively). Although stabilization of photoelectric responses upon long-term continuous illumination was observed for both variants of chromatophore immobilization, only the samples immersed into the MF retained the functional activity of reaction centers (RCs) for a month when stored in the dark at room temperature, which might be due to the preservation of integrity of chromatophore proteins inside the MF pores. The stabilizing effect of the bioprotector trehalose could be related to its effect on both the RC proteins and the phospholipid bilayer membrane. The results obtained will expand current ideas on the use of semi-synthetic structures based on various intact photosynthetic systems capable of converting solar energy into its electrochemical form. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
29. Influence of Layer-Thickness Proportions and Their Strength and Elastic Properties on Stress Redistribution during Three-Point Bending of TiB/Ti-Based Two-Layer Ceramics Composites.
- Author
-
Khvostunkov, Kirill, Bazhin, Pavel, Ni, Qing-Qing, Bazhina, Arina, Chizhikov, Andrey, and Konstantinov, Alexander
- Subjects
ELASTICITY ,SELF-propagating high-temperature synthesis ,YOUNG'S modulus ,FLEXURAL strength ,STRENGTH of materials ,CERAMICS ,BENDING strength - Abstract
A mathematical model was developed to determine the order of failure of layers in a two-layer ceramics composite and to determine the conditions for achieving the maximum limit load under three-point loading. The model was set in the space of three "bilayer parameters": the ratio of the thickness of the lower layer to the whole thickness of the beam, the ratio of Young's moduli of the lower layer to the upper layer, and the ratio of flexural strengths of the materials of the lower layer to the upper layer. The adequacy of the model obtained was confirmed by experimental results on the three-point bending of the experimental specimens. The experimental samples were two-layer composites consisting of a cermet layer TiB/Ti and a layer of α-Ti. The samples were obtained by free self-propagating high-temperature synthesis (SHS) compression and with varying their thickness. The results obtained make it possible to predict in advance which layer, based on the specific bilayer parameters, will trigger the brittle fracture mechanism as well as to set the maximum destructive load of bilayer composites. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
30. Enhancing DNA barcode reference libraries by harvesting terrestrial arthropods at the Smithsonian's National Museum of Natural History.
- Author
-
Santos, Bernardo F., Miller, Meredith E., Miklasevskaja, Margarita, McKeown, Jaclyn T. A., Redmond, Niamh E., Coddington, Jonathan A., Bird, Jessica, Miller, Scott E., Smith, Ashton, Brady, Seán G., Buffington, Matthew L., Chamorro, M. Lourdes, Dikow, Torsten, Gates, Michael W., Goldstein, Paul, Konstantinov, Alexander, Kula, Robert, Silverson, Nicholas D., Solis, M. Alma, and deWaard, Stephanie L.
- Subjects
GENETIC barcoding ,ARTHROPODA ,NATURAL history ,BIODIVERSITY ,ECOSYSTEM services - Abstract
The use of DNA barcoding has revolutionised biodiversity science, but its application depends on the existence of comprehensive and reliable reference libraries. For many poorly known taxa, such reference sequences are missing even at higher-level taxonomic scales. We harvested the collections of the Smithsonian's National Museum of Natural History (USNM) to generate DNA barcoding sequences for genera of terrestrial arthropods previously not recorded in one or more major public sequence databases. Our workflow used a mix of Sanger and Next-Generation Sequencing (NGS) approaches to maximise sequence recovery while ensuring affordable cost. In total, COI sequences were obtained for 5,686 specimens belonging to 3,737 determined species in 3,886 genera and 205 families distributed in 137 countries. Success rates varied widely according to collection data and focal taxon. NGS helped recover sequences of specimens that failed a previous run of Sanger sequencing. Success rates and the optimal balance between Sanger and NGS are the most important drivers to maximise output and minimise cost in future projects. The corresponding sequence and taxonomic data can be accessed through the Barcode of Life Data System, GenBank, the Global Biodiversity Information Facility, the Global Genome Biodiversity Network Data Portal and the NMNH data portal. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
31. Five new species of the genus Griburius Haldeman from Central America (Coleoptera: Chrysomelidae, Cryptocephalinae).
- Author
-
SASSI, Davide
- Subjects
SPECIES ,BEETLES ,CHRYSOMELIDAE - Abstract
Five new species of Griburius Haldeman, 1849 are described from Central America. The new taxa have been named: Griburius febriculosus sp. nov. from Mexico; Griburius gracilis sp. nov. from Mexico; Griburius mokaya sp. nov. from Costa Rica, Guatemala, Honduras, Mexico and Panama; Griburius puncturatus sp. nov. from Mexico; Griburius textus sp. nov. from Belize and Mexico. Besides, two further species of the same genus, i. e. Griburius gamma (Jacoby, 1889) from Mexico and Griburius equestris (Olivier, 1808) from the South of the U.S.A. have been redescribed and revised to make suitable comparisons possible. The lectotype of Griburius gamma and a neotype of Griburius equestris have been designated. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
32. Role of sorbents in early growth of barley under copper and benzo(a)pyrene contaminated soils.
- Author
-
Barakhov, Anatoly, Chernikova, Natalia, Dudnikova, Tamara, Barbashev, Andrey, Sushkova, Svetlana, Mandzhieva, Saglara, Rajput, Vishnu, Kızılkaya, Rıdvan, Konstantinova, Elizaveta, Bren, Dmitry, Minkina, Tatiana, and Konstantinov, Alexander
- Subjects
SOIL pollution ,SOIL remediation ,SORBENTS ,PYRENE ,POLYCYCLIC aromatic hydrocarbons ,BARLEY ,SOILS - Abstract
In modern economic and industrial realities, agricultural lands are often located next to industrial areas, which leads to soil contamination and, as a result, agricultural products with pollutants. Pollution of soils and plants by several pollutants of various nature has acquired huge proportions. There is a threat of migration of dangerous ecotoxicants, including heavy metals and benz[a]pyrene, one of the main persistent compounds, a marker of PAH soil contamination, along trophic chains that may be dangerous to public health. This study examines the use of various types of mineral sorbents (Tripoli, Brown coal, Diatomite) and mineral sorbents (Biochar, Granular activated coal) to reduce the toxic effects of pollutants on the sources of anthropogenic emissions of heavy metals and polycyclic aromatic hydrocarbons adjacent to the sources. Using scanning electron microscopy, it was found that the sorbents have a high specific surface area. With the help of phytotesting in combined contaminated soils, the optimal dose of sorbent administration was determined at the level of 1% and 2% for various pollution variants. In addition, the analyzed sorbents are ordered by the effect of reducing the phytotoxicity of combined soil pollution. It was found that the introduction of sorbents into contaminated soil contributed to an increase in the morphometric parameters of the test culture - barley (Hordeum sativum distichum), which confirms the effectiveness of the sorption remediation of jointly contaminated soils with heavy metals and benz(a)pyrene. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
33. Land-Use Changes on Ob River Floodplain (Western Siberia, Russia) in Context of Natural and Social Changes over Past 200 Years.
- Author
-
Ivanov, Vladimir, Milyaev, Ivan, Konstantinov, Alexander, and Loiko, Sergey
- Subjects
FLOODPLAINS ,SOCIAL change ,LAND cover ,AGRICULTURAL development ,SOCIAL context ,FLOODS - Abstract
Over the past century, substantial changes in land use have taken place in the boreal zone of northern Eurasia. The consequences of these large-scale changes for the ecosystems of Europe have been well studied; however, they have not been addressed for the large expanses of Russia. We conducted a retrospective analysis of the landscape dynamics of the middle reaches of the Ob floodplain (Western Siberia) using multitemporal maps of the vegetation cover and land use for five time points (1830, 1910, 1950, 1976, and 2019). By the 1830s, all the land that was suitable for haymaking and plowing (rarely flooded and not swamped) had been put to agricultural use. The meadows of the Ob floodplain are human-controlled and were mainly formed before the 1830s. From the 1830s to the 1990s, the meadows were used in agriculture and their areas increased. The maximum development of the floodplain occurred in the 1970s and 1980s, when previous wetlands were put into operation through the construction of drainage systems. A massive abandonment of pastures and reclaimed land occurred in the late 20th century. According to the data over the last 30 years, abandoned meadows are resistant to overgrowth with trees and shrubs. The spatial configurations of the floodplain landscapes have also been quite stable. The main spatial changes are confined to the near-channel floodplain, with the formation of new near-channel shallows. The floodplain landscapes of the Ob River demonstrate substantial spatial and temporal stabilities, and long-standing agricultural development. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
34. Museum Genomics of an Agricultural Super-Pest, the Colorado Potato Beetle, Leptinotarsa decemlineata (Chrysomelidae), Provides Evidence of Adaptation from Standing Variation.
- Author
-
Cohen, Zachary P, François, Olivier, and Schoville, Sean D
- Subjects
COLORADO potato beetle ,INSECTICIDE resistance ,GENOMICS ,GENETIC variation ,AGRICULTURAL pests ,BEETLES ,GENE frequency ,CHRYSOMELIDAE - Abstract
Despite extensive research on agricultural pests, our knowledge about their evolutionary history is often limited. A mechanistic understanding of the demographic changes and modes of adaptation remains an important goal, as it improves our understanding of organismal responses to environmental change and our ability to sustainably manage pest populations. Emerging genomic datasets now allow for characterization of demographic and adaptive processes, but face limits when they are drawn from contemporary samples, especially in the context of strong demographic change, repeated selection, or adaptation involving modest shifts in allele frequency at many loci. Temporal sampling, however, can improve our ability to reconstruct evolutionary events. Here, we leverage museum samples to examine whether population genomic diversity and structure has changed over time, and to identify genomic regions that appear to be under selection. We focus on the Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say 1824; Coleoptera: Chrysomelidae), which is widely regarded as a super-pest due to its rapid, and repeated, evolution to insecticides. By combining whole genome resequencing data from 78 museum samples with modern sampling, we demonstrate that CPB expanded rapidly in the 19th century, leading to a reduction in diversity and limited genetic structure from the Midwest to Northeast United States. Temporal genome scans provide extensive evidence for selection acting in resistant field populations in Wisconsin and New York, including numerous known insecticide resistance genes. We also validate these results by showing that known selective sweeps in modern populations are identified by our genome scan. Perhaps most importantly, temporal analysis indicates selection on standing genetic variation, as we find evidence for parallel evolution in the two geographical regions. Parallel evolution involves a range of phenotypic traits not previously identified as under selection in CPB, such as reproductive and morphological functional pathways that might be important for adaptation to agricultural habitats. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
35. Multiple origins of moss-inhabiting flea beetles (Coleoptera: Chrysomelidae): molecular phylogeny, overview of genera and a new genus from Africa.
- Author
-
Damaška, Albert František, Konstantinov, Alexander, and Fikáček, Martin
- Subjects
FLEA beetles ,MOLECULAR phylogeny ,CHRYSOMELIDAE ,BEETLES ,CLOUD forests - Abstract
Flea beetles (Alticini) are a diverse lineage of leaf beetles (Coleoptera: Chrysomelidae) with the majority of genera living on vascular plants. However, several genera are associated with mosses or leaf litter, as an alternative strategy, often accompanied by changes in morphology and biology. Here, we present the first comprehensive DNA-based phylogenetic analysis of Alticini including 13 moss-inhabiting genera. We show that moss-association is a common phenomenon in Alticini; based on our ancestral-state mapping, we reveal at least nine independent origins of moss-inhabiting, and four independent origins of leaf-litter-inhabiting life-strategy. Our findings illustrate that both cryptic strategies induce parallel evolution of similar ecomorphological adaptations, such as flight loss and a convex body shape. An overview of known moss-inhabiting flea beetle genera is also provided. We describe Benedictoides munclingeri gen. et sp. nov. from the cloud forests of Mount Cameroon, the first flea beetle genus clearly assigned to the moss-inhabiting strategy from tropical Africa. Additionally, our phylogeny provides new insights into the relationships among various flea beetle genera. We estimate six main clades grouping the majority of studied genera, and propose several new generic groups. Along with our phylogenetic results, we discuss moss-inhabiting flea beetle evolution and perspectives of their systematics. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
36. SPIRIT LIVES WHEREVER IT CHOOSES: THE ART OF MILA GOKHMAN.
- Author
-
Feinstein, Roni
- Abstract
The article discusses the life, career, and accomplishments of Ukrainian American artist Mila Gokhman. Topics explored include the way music, poetry, and nature serve as inspiration for her artworks, the abstract art techniques she demonstrated while in the Soviet Union in the 1960s, and her use of leather in the paintings "Spheres," "Golden Rain (Manna from Heaven to the Suffering Earth)," and "Sunset in the Golosievo Forest."
- Published
- 2022
37. A review of the sinica species group within the genus Lilioceris (Coleoptera, Chrysomelidae, Criocerinae).
- Author
-
Yuan Xu and Hongbin Liang
- Subjects
BEETLE anatomy ,FEMALE reproductive organs ,MALE reproductive organs ,SPECIES ,HOST plants ,BEETLES ,CHRYSOMELIDAE - Abstract
A new species group of the genus Lilioceris Reitter, 1913 is proposed and reviewed, the sinica group. It includes six species: L. gressitti Medvedev, 1958; L. rugata (Baly, 1865); L. sieversi (Heyden, 1887); L. sinica (Heyden, 1887); L. theana (Reitter, 1898) stat. nov.; and L. thibetana (Pic, 1916). Among them, L. theana is resurrected as a valid species from synonymy with L. rugata, and is newly reported from China. Redescriptions, an identification key, figures of habitus and male and female genitalia, geographic distributions, host plants, and habitats (if known) are provided for these species. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
38. Functional Morphology of the Thorax of the Click Beetle Campsosternus auratus (Coleoptera, Elateridae), with an Emphasis on Its Jumping Mechanism.
- Author
-
Ruan, Yongying, Zhang, Mengna, Kundrata, Robin, Qiu, Lu, Ge, Siqin, Yang, Xingke, Chen, Xiaoqin, and Jiang, Shihong
- Subjects
JUMP processes ,BEETLES ,MORPHOLOGY - Abstract
Simple Summary: Click beetles are well-known for the specialized thoracic structure, which they can click to thrust themselves into the air and to right themselves. Several aspects of their jumping mechanism were still not entirely clear prior to this study. We utilized traditional dissection, 3D virtual dissection, and high-speed filming techniques to investigate the functional morphology of their thorax. Our results show several new insights into their extraordinary clicking and jumping mechanisms. We investigated and described the thoracic structures, jumping mechanism, and promesothoracic interlocking mechanism of the click beetle Campsosternus auratus (Drury) (Elateridae: Dendrometrinae). Two experiments were conducted to reveal the critical muscles and sclerites involved in the jumping mechanism. They showed that M2 and M4 are essential clicking-related muscles. The prosternal process, the prosternal rest of the mesoventrite, the mesoventral cavity, the base of the elytra, and the posterodorsal evagination of the pronotum are critical clicking-related sclerites. The destruction of any of these muscles and sclerites resulted in the loss of normal clicking and jumping ability. The mesonotum was identified as a highly specialized saddle-shaped biological spring that can store elastic energy and release it abruptly. During the jumping process of C. auratus, M2 contracts to establish and latch the clicking system, and M4 contracts to generate energy. The specialized thoracic biological springs (e.g., the prosternum and mesonotum) and elastic cuticles store and abruptly release the colossal energy, which explosively raises the beetle body in a few milliseconds. The specialized trigger muscle for the release of the clicking was not found; our study supports the theory that the triggering of the clicking is due to the building-up of tension (i.e., elastic energy) in the system. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
39. The entrepreneurship ecosystem: stability and dynamism of social norms in digital transformation.
- Author
-
Nazarov, A.D., Shkalenko, Anna, and Konstantinov, Alexander
- Published
- 2021
- Full Text
- View/download PDF
40. Mechanical Activation of Smectite-Based Nanocomposites for Creation of Smart Fertilizers.
- Author
-
Rudmin, Maxim, Banerjee, Santanu, Makarov, Boris, Ibraeva, Kanipa, and Konstantinov, Alexander
- Subjects
MONTMORILLONITE ,UREA as fertilizer ,FOURIER transform infrared spectroscopy ,FERTILIZERS ,SOIL leaching ,NANOCOMPOSITE materials - Abstract
This research presents the mechanical creation of smart fertilizers from a mixture of smectite and urea in a 3:2 ratio by using the planetary milling technique. The smectite–urea composites show intercalation between urea and mineral, which increases steadily with increasing activation time. A shift of X-Ray Diffraction basal reflections, intensities of Fourier transform infrared spectroscopy (FTIR) peaks, and weight losses in thermogravimetric analysis (TG) document the systematic crystallo-chemical changes of the composites related to nitrogen interaction with activation. Observations of the nanocomposites by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) corroborate the inference. Nitrogen intercalates with smectite in the interlayer space and remains absorbed either within micro-aggregates or on the surface of activated smectites. Soil leaching tests reveal a slower rate of nitrogen than that of traditional urea fertilizers. Different forms of nitrogen within the composites cause their differential release rates to the soil. The formulated nanocomposite fertilizer enhances the quality and quantity of oat yield. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
41. Phylogenetic analysis of the family Megalopodidae (Coleoptera: Chrysomeloidea): better taxon‐sampling facilitates detection of new relationships and new taxa.
- Author
-
Rodríguez‐Mirón, Geovanni M., Zaragoza‐Caballero, Santiago, and Morrone, Juan J.
- Subjects
GONDWANA (Continent) ,PARSIMONIOUS models ,BEETLES ,ADULTS ,LIFTING & carrying (Human mechanics) ,TRIBES - Abstract
The systematics of Megalopodidae is not adequately known, in spite of it being a relatively small group of phytophagous beetles. The first phylogenetic analysis of Megalopodidae with a comprehensive generic representation (25 genera of 30 described, 10 subgenera and 77 species) is undertaken. A parsimony analysis under equal and implied weights was carried out based on 147 adult and larval morphological characters. Subfamilies Palophaginae and Zeugophorinae were recovered as monophyletic, by contrast with Megalopodinae, which proved to be paraphyletic. Atelederinae are proposed as a new subfamily. Also, three tribes and three subtribes within Megalopodinae are proposed: Leucasteini trib.n., Sphondyliini trib.n. and Megalopodini, the latter including Macrolophina subtrib.n., Temnaspidina subtrib.n. and Megalopodina. The genera Macrolopha, Kuilua, Poecilomorpha, Temnaspis, Antonaria, Agathomerus, Megalopus and Bothromegalopus were recovered as non‐monophyletic. New delimitations of the polyphyletic genera Poecilomorpha and Macrolopha are proposed, Clythraxeloma is resurrected, and the subgenera of Agathomerus are suppressed. The following new combinations are proposed: Kuilua apicata (Fairmaire), K. nyassae (Jacoby), Poecilomorpha cribricollis (Pic), P. minuta (Pic), Clythraxeloma assamensis (Jacoby), C. bipartita (Lacordaeri), C. discolineata (Pic), C. downesii (Baly), C. gerstaeckeri (Westwood), C. laosensis (Pic), C. maculata (Pic), C. mouhoti (Baly), C. nigrocyanea (Motschulsky), C. pretiosa (Reineck), Temnaspis tricoloripes (Pic) and Barticaria faciatus (Dalman). Clythraxeloma cyanipennis Kraatz is a restored combination. Distribution patterns of Megalopodidae largely conform to the breakup of Gondwanaland, with its main clades having particular distributions: Andean‐Australian (Palophaginae), Ethiopian (Leucasteini, Sphondyliini, and Macrolophina), Neotropical (Ateledrinae and Megalopodina) and Ethiopian‐Oriental‐Palaearctic (Temnaspidina the result of a secondary expansion. Zeugophorinae present a worldwide distribution, except for the Neotropical and Andean regions, which may be the result of geodispersal. The findings of the present study also shed light on groups with taxonomic issues, where phylogenetic analyses are strongly needed. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
42. Generation of Photoelectric Responses by Photosystem II Core Complexes in the Presence of Externally Added Cytochrome c.
- Author
-
Vitukhnovskaya, Liya A., Simonyan, Ruben A., Semenov, Alexey Yu., and Mamedov, Mahir D.
- Subjects
PHOTOSYSTEMS ,CHARGE exchange ,ELECTRON donors ,ELECTROPHILES ,QUINONE ,LIPOSOMES ,CYTOCHROME c ,SOLAR system - Abstract
The effect of exogenous cytochrome c (cyt c) on kinetics of photoelectric responses (Δψ) of two types of photosystem II (PSII) core complexes (intact – PSII with active water-oxidizing complex and Mn-depleted complex) reconstituted into liposomes has been investigated by direct electrometric technique. PSII complexes were localized in the proteoliposome membranes with their donor side outward. An additional electrogenic phase was observed in the kinetics of Δψ generation in response to a laser flash besides the main fast (<0.3 µs) electrogenic component due to electron transfer from the redox-active tyrosine Y
Z to the primary quinone acceptor QA in the presence of oxidized cyt c (cyt c3 + ) entrapped in the internal space of proteoliposomes with intact PSII complexes. This component with characteristic time τ ≈ 40 µs and relative amplitude of ~10% of the total Δψ was attributed to the vectorial electron transfer from QA − to cyt c3+ serving as an external acceptor. An additional electrogenic component with τ ~ 70 µs and a relative amplitude of ~20% of the total Δψ also appeared in the kinetics of Δψ formation, when cyt c2 + was added to the suspension of proteoliposomes containing Mn-depleted PSII core complexes. This component was attributed to the electrogenic transfer of an electron from cyt c2 + to photooxidized tyrosine YZ . These data imply that cyt c3+ serves as a very effective exogenous electron acceptor for QA − in the case of intact PSII core complexes, and cyt c2+ is an extremely efficient artificial electron donor for YZ in the Mn-depleted PSII. The obtained data on the roles of cyt c2+ and cyt c3 + as an electron donor and acceptor for PSII, respectively, can be used to develop hybrid photoelectrochemical solar energy-converting systems based on photosynthetic pigment–protein complexes. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
43. Volume contents.
- Published
- 2021
- Full Text
- View/download PDF
44. Revision of Oriental flea beetle genera with subparallel intercoxal ridges on the first abdominal ventrite (Coleoptera, Chrysomelidae, Galerucinae, Alticini).
- Author
-
Prathapan, K.D. and Konstantinov, A.S.
- Subjects
FLEA beetles ,CHRYSOMELIDAE ,BEETLES ,SYNONYMS ,SPECIES - Abstract
The Oriental flea beetle genera (Coleoptera, Chrysomelidae, Galerucinae, Alticini) with subparallel intercoxal ridges on the first abdominal ventrite are revised. Sahyadrialtica stephaniae gen. nov. and sp. nov. from south India are described. The following new synonyms are proposed: Lankanella Kimoto, 2000 syn. nov. (= Parategyrius Kimoto and Gressitt, 1966), Lankaphthona Medvedev, 2001 syn. nov. (= Parategyrius Kimoto and Gressitt, 1966), Paraphthona Medvedev, 2009 syn. nov. (= Parategyrius Kimoto and Gressitt, 1966) and Neorthella Medvedev, 2010 syn. nov. (= Lanka Maulik, 1926). Sphaeraltica Ohno, 1961 is proposed as the new replacement name for Ogloblinia Csiki, 1940 instead of Lesagealtica Döberl, 2009. New combinations are proposed due to the new and previously published synonyms. A checklist, comprising 96 species belonging to 10 genera in the Tegyrius genus group, is provided. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
45. Description of two new species of Glenea Newman, 1842 from southern India and reinstatement of Glenea vestalis Heller, 1934 (Coleoptera: Cerambycidae: Lamiinae: Saperdini).
- Author
-
Hiremath, Sangamesh R. and Lin, Mei-Ying
- Subjects
CERAMBYCIDAE ,SPECIES ,LIFE history theory ,BEETLES ,STAPHYLINIDAE - Abstract
Two new species of the genus Glenea Newman, 1842 are described from south India. Glenea vellayaniensis sp. nov. is described from Vellayani, a suburb of Trivandrum district, along the coastline of Kerala, and G. pseudoalbosignatipennis sp. nov. is described from the southern Western Ghats. Glenea vestalis Heller, 1934, previously treated as a junior synonym of G. pulchella Pascoe, 1858, is reinstated as a valid species owing to its differences in morphological and genital characters; in addition, both species are illustrated and revised. Glenea vellayaniensis sp. nov. is provisionally placed under Glenea sensu lato and compared with its morphologically similiar congeners, G. pulchella Pascoe, 1858 and G. vestalis Heller, 1934 along with comments on its generic affinity. Glenea pseudoalbosignatipennis sp. nov. is compared with G. albosignatipennis Breuning, 1950 and G. signaticollis Gahan, 1889 and a note on its life history is provided. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
46. Four peculiar new Metallactus species from Argentina (Coleoptera: Chrysomelidae, Cryptocephalinae).
- Author
-
SASSI, Davide
- Subjects
CHRYSOMELIDAE ,BEETLES ,CONVERGENT evolution ,SPECIES ,BEETLE anatomy ,STAPHYLINIDAE - Abstract
Metallactus canescens sp. nov., Metallactus aemulus sp. nov., Metallactus diaguita sp. nov., Metallactus nugator sp. nov. are described from Northern and Central Argentina. The new species are very similar to one another regarding their external look but can be distinguished above all on the basis of internal characters, in particular the morphology of the aedeagal median lobe. Besides, some traits of their external features, i. e. the thick dorsal setosity and the weak metallic hue, look quite uncommon within the genus Metallactus Suffrian, 1866 and remind of some species of genus Coscinoptera Lacordaire, 1848 (in particular C. tibialis Harold, 1875) and other undescribed species belonging to the genus Griburius Haldeman, 1849. This might be due to some kind of adaptive convergent evolution. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
47. Strain Rate Dependencies and Competitive Effects of Dynamic Strength of Some Engineering Materials.
- Author
-
Smirnov, Ivan and Konstantinov, Alexander
- Subjects
MATERIALS ,STRAIN rate ,DYNAMIC testing of materials ,DYNAMIC loads ,COMPRESSION loads ,COPPER-titanium alloys - Abstract
Comparison of strength characteristics of engineering materials is usually based on comparison of data from quasi-static tests. However, under dynamic loads, strength characteristics of materials are unstable and the strength ratio of two materials can change dramatically. This paper presents a comparative study of the strain/stress rate dependencies of the critical stresses of various quasi-brittle and ductile engineering materials, as well as their various internal states. A case of continuously increasing load in compression and splitting tests is considered. Experimental results were obtained for bricks, mortar and limestone in dry, saturated and frozen states; copper and titanium in different structural states; and road bitumens with different modifiers. The results show that such dependencies can intersect, thereby realizing a strength competition effect. This means that one material can withstand higher stresses under a quasi-static load and lower stresses under a dynamic load in comparison with another material. Thus, such an intersection suggests that the choice of a material based on quasi-static parameters may be erroneous for structures intended for dynamic modes. The analysis of strain/stress rate dependencies of ultimate or yield strength is carried out on the basis of the incubation time approach. The introduction of dynamic strength characteristics with the dimension of time is considered. This parameter characterizes well the response of the materials to dynamic loading. The calculation results show the possibility of estimating the critical stresses and the strength competition effect at high rate loads using no more than three parameters, which can be easily used in engineering practice. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
48. Algorithm for calculating hazard areas of a rock massif based on geomechanical data.
- Author
-
Guzev, M., Rasskazov, I., Makarov, V., Gladyr, Andrei, Rasskazov, Maksim, Konstantinov, Alexander, and Tereshkin, Andrei
- Published
- 2019
- Full Text
- View/download PDF
49. New State Records and Additions to the Alien Terrestrial Arthropod Fauna in the Hawaiian Islands.
- Author
-
Matsunaga, Janis N., Howarth, Francis G., and Kumashiro, Bernarr R.
- Subjects
PUBLIC records ,INTRODUCED species ,ANIMALS ,ISLANDS ,ACQUISITION of data - Abstract
An annotated list of 393 adventive terrestrial arthropod species plus three new varieties of known established species, which have been recorded in Hawaii since the Fourth Edition of Bishop Museum's Hawaiian Terrestrial Arthropod Checklist (Nishida 2002), is presented. This compilation includes records of over 362 nonnative arthropod species published between the years of 2001 and 2017 as well as over 30 new Hawaii State records that have not been previously recorded. Annotations include date first detected, island distribution, citation, relevant biological notes, and for new state and island records, the collection data. A separate table with about 150 entries lists the synonyms, misidentifications, deletions, and changes of status for species included in the 2002 checklist that were discovered during our research. However, the latter list is not comprehensive as a complete revision of the 2002 checklist was beyond the scope of our project. Also included is a bibliography of the approximately 270 source documents that were consulted. We intend for this publication to be a useful supplement to the 2002 edition of the Hawaiian Terrestrial Arthropod Checklist. [ABSTRACT FROM AUTHOR]
- Published
- 2019
50. Creation of database for strength calculation of constructions.
- Author
-
Bragov, Anatoly, Isaev, Sergey, Kapustin, Sergey, Konstantinov, Alexander, and Lomunov, Andrey
- Subjects
CONSTRUCTION materials ,STRENGTH of materials ,COMPUTER systems ,CLIENT/SERVER computing ,MICROSOFT .NET Framework - Abstract
The problems of creation of an automated system for obtaining, processing and storing experimental information on the physical and mechanical properties of structural materials, building materials and various soil media used to provide information support for automated computing systems for analysis of strength and design of structures are discussed. The developed database is focused on studying the effects of the behavior of structural materials under highly parametric influences of force, temperature and other physical fields, as well as on equipping and experimental substantiation of mathematical models describing these effects. In the proposed variant, the database is implemented as a client-server application executed on the Microsoft.Net Framework using a powerful database management system MS SQL Server. The content of the created bank is made up of sections of primary information, material properties and material models. In order to automate the processing of data at all stages of information conversion, a special "Desktop" subsystem is included in the bank, which allows aggregating data obtained from several different experiments, correcting the selected data, processing and converting it. Processing and transformation of data in the subsystem "Desktop" can be carried out either in manual mode or on the basis of special algorithms using appropriate mathematical methods. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
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