Morphology of crater and caldera lakes in the Far Eastern region of Russia and the features of their development

Volcanic lakes in the Kuril-Kamchatka region are difficult to access,and for this reason,they remain poorly studied,with only scattered and brief data available.The authors have conducted a study of 10 lake basins using modern digital echolocation survey techniques and have also compiled and summarized published data for 15 lakes in the region,calculating their main morphometric characteristics.It has been established that many caldera lake basins are modified by young explosive funnels,extrusive or effusive domes,and exhibit traces of hydrothermal activity.While lakes of the same genetic type in the Kuril-Kamchatka region are similar in depth and depression forms,the group of caldera lakes shows less homogeneity across all morphometric indicators.It was found that the absolute heights of the reservoirs on Kamchatka Peninsula are generally greater than those on the Kuril Islands,as is often the case with the size of their basins.The volcanic lakes under study can rapidly change their volume and shape under the influence of endogenous processes.For the first time for this region,on the base of repeated observations,underwater extrusive dome rate growth and the approximate rates of 2 lake level changes were calculated.Repeated observations of lakes in the Ksudach calderas(Kamchatka)and on Simushir Island indicate approximate rates of level changes:a decrease ranging within 0.5-0.6 m per year(over a 27-year observation interval)and an increase reaching up to 0.26 m per year(over a 48-year interval).The growth rate of the underwater extrusive dome in Lake Shtyubel has averaged 1-1.6 m per year over the past 25 years.This analysis has facilitated the first generalization regarding the morphology and developmental features of crater and caldera lakes in the Kuril-Kamchatka region of Russia,representing an important step in their study.The results obtained will provide a solid foundation for subsequent research in this region and may be of interest to researchers studying other volcanic lakes.

Effect of chitosan on tobacco mosaic virus(TMV) accumulation, hydrolase activity, and morphological abnormalities of the viral particles in leaves of N. tabacum L. cv. Samsun

The effect of chitosan on the development of infection caused by Tobacco mosaic virus(TMV) in leaves of Nicotiana tabacum L. cv. Samsun has been studied. It was shown that the infectivity and viral coat protein content in leaves inoculated with a mixture of TMV(2 μg/mL) and chitosan(1 mg/mL) were lower in the early period of infection(3 days after inoculation), by 63% and 66% respectively, than in leaves inoculated with TMV only. Treatment of leaves with chitosan 24 h before inoculation with TMV also caused the antiviral effects, but these were less apparent than when the virus and polysaccharide were applied simultaneously. The inhibitory effects of the agent decreased as the infection progressed. Inoculation of leaves with TMV together with chitosan considerably enhanced the activity of hydrolases(proteases, RNases) in the leaves, in comparison with leaves inoculated with TMV alone. Electron microscope assays of phosphotungstic acid(PTA)-stained suspensions from infected tobacco leaves showed that, in addition to the normal TMV particles(18 nm in diameter, 300 nm long), these suspensions contained abnormal(swollen, "thin" and "short") virions. The highest number of abnormal virions was found in suspensions from leaves inoculated with a mixture of TMV and chitosan. Immuno-electron microscopy showed that "thin" virus particles, in contrast to the particles of normal diameter, lost the ability to bind to specific antiserum. It seems that the chitosan-induced activation of hydrolases stimulates the intracellular degradation of TMV particles and hence hydrolase activation may be considered to be one of the polysaccharide-mediated cellular defense mechanisms that limit virus accumulation in cells.

Review of the Permian Camptoneuritidae(Insecta:Grylloblattida)

The Permian family Camptoneuritidae （Insecta： Grylloblattida） is reviewed. New synonymies are proposed： Camptoneuritidae Martynov, 1930 = Demopteridae Carpenter, 1950, syn. nov., = Jabloniidae Kukalova, 1964, syn. nov. Key to genera of Camptoneuritidae is given. All genera are redescribed and illustrated. Camptoneurites soyanensis sp. nov. from Soyana locality （Middle Permian, Kazanian Stage; Arkhangelsk Region, Russia） and Tyulkinia bashkuevi gen. et sp. nov. from Tyulkino locality （Lower Permian, Kungurian Stage; Perm Region, Russia） are described.

A New Mantispid-Like Species of Rhachiberothinae (Neuroptera:Berothidae) from Baltic Amber,with a Critical Review of the Fossil Record of the Subfamily

Whalfera wiszniewskii sp. nov. is described from the Late Eocene Baltic amber. The genus Whalfera is considered as the only fossil genus confidently assigned to the Rhachiberothinae. Others previously placed in this subfamily belong to Paraberothinae （except perhaps for Oisea）. The Late Eocene/present Rhachiberothinae and the Cretaceous Paraberothinae are considered to be the subfamilies of Berothidae.

Structural traits of woody plants and geomorphological conditions to the vegetation recovery at Ksudach caldera(Southern Kamchatka) since the explosive eruption in 1907

This study considers the restoration of the plant cover destroyed by a catastrophic volcano eruption in the south of Kamchatka Peninsula(the Ksudach caldera,Shtyubel cone),with a particular attention to the role of woody plants.It aims to qualitatively estimate(at a qualitative level)the rate of the primary succession development depending on the microrelief and the modern relief-forming processes.The vegetation recovery in the caldera after the Shtyubel cone eruption 109 years ago proceeds slowly and irregularly.It proceeds most slowly on a thick tephra mantle continuously disturbed by water and wind erosion,lahars,debris flows,landslides,etc.Such conditions are most typical of the western part of the caldera dominated by pumice fields with occasional patches of pioneer herbs and dwarf shrubs.Alpine tundra communities with gradually expanding patches of shrub alder develop in the southern,eastern and northeastern parts of the Ksudach caldera.Since 1997 the area of the shrub alder communities has increased by 1.9 times,while the alpine tundra–by 1.3 times only.The woody plants(dwarf shrubs and prostrate shrubs)are of particular importance in the process of the vegetation recovery on pumice fields.We suggest that the bark thickness of woody plants is an integrated indicator,which may serve for estimating the state of ecosystem in the course of the primary succession development on juvenile sediments.The extremely inhospitable environments cause changes in physiological processes in the plant body and in its bark in particular.The results show that woody plants have a"thin"bark and develop some structural-functional arrangements for keeping bark tissues at their minimum.So,the woody plant structure and the rate of changes in plant communities are under control of the geomorphic conditions and primarily–of physicochemical features of the pyroclastic cover.

Differing migration patterns and year-round habitat-use of allopatric nesting Eastern Tundra Bean Geese(Anser fabalis serrirostris)in East Asia

Sympatric Chinese-wintering Eastern Tundra Bean Geese(Anser fabalis serrirostris,ETBG)breed in two widely separated Arctic areas(Central Russian Arctic and Anadyr region);South Korean-wintering birds(Chaun-South Korea)breed in a third discrete area between these two.Such winter/summer segregation likely structures the population,potentially resulting in distinct migration patterns and habitat-use throughout the annual cycle.We tracked individuals using GPS-GSM transmitters from all three of these geographically discrete ETBG subpopulations to see whether this was the case,testing for differences in migration patterns,seasonal and diurnal habitat-use using remotely sensed land-cover mapping.Mean migration distance of Central Arctic-China and Chaun-South Korea individuals did not differ significantly,but Anadyr-China birds travelled 15–24%further(mean:1140 km,P<0.001).Despite this,mean spring migration durations were longest among Central ArcticChina ETBG,significantly longer than Anadyr-China geese,due to significantly longer stopovers,which were significantly longer than Chaun-South Korea birds.Autumn migration duration of Central Arctic-China and Chaun-South Korea individuals was significantly shorter than in spring,with fewer,shorter stopovers.Lack of significant differences in migration and stopover duration or numbers of stopovers between spring and autumn among Anadyr-China ETBG confirms this is a plastic trait,differing between subpopulations responding to prevailing conditions.Migration patterns and habitat-use differed significantly between all three ETBG subpopulations,although all tended to use wetlands more at night and croplands more in daytime in winter,suggesting specific adaptations and responses to differing conditions encountered along their different migration routes.Although untestable,we speculate that differences in habitat-use may affect fitness levels and genetic exchange between subpopulations,but based on our observations,conclude clear differences in migration and foraging ecology between these elements of the same subspecies,even in winter sympatry.

Reconstruction of the Indigenous Sources of Gold of the Glu-Kharinsky Placer (Kolyma River Basin, Magadan Region, Russia)

A comparative analysis of typomorphic features of gold placers and indigenous sources of gold was carried out for the Glukharinsky ore-placer node (the Nadezhda deposit and Glukharinskoye, Tyomnoye, and Tyi-Jurye ore occurrences). A correlation between fineness of placer native gold and composition of relic minerals preserved inside gold particles was obtained for the first time. This made it possible to establish mineral parageneses of native gold from potential indigenous sources. The study of placer gold fineness in combination with com-position of mineral inclusions allowed us to identify seven types of gold paragenesis: petzite-hessite with a fineness of 855‰, pyrite-polybasite-galena (a fineness of 670‰), bismuth telluride (900‰), cosalite-vikingite (790‰), galena (870‰), glaucodot (950‰), and hydrohematite (840‰). It was also shown that the placer contains the material from ore occurrences of different formation: gold-quartz-porphyry occurrences in granitoids (Au-Te-Bi type) and gold-silver occurrences. The method developed by us allows one to estimate the percentage of each ore source in placer formation.

Gupeiite Body in the Siberian Taiga (the Zone of Passage of the Tunguska Meteorite and the Vitim Bollid)

Many years have passed since the two cosmic bodies of the Tunguska meteorite and the Vitim bollid fell to Earth, but so far the substance of these bodies has not been found on Earth. Therefore, each metal body found on the territory of their passage is of particular interest. The body of iron silicide weighing 12 kg was studied, which was accidentally discovered by a hunter of the village of Kyker in the Siberian taiga on the right bank of the Nercha River, Tungokochensky district, Trans-Baikal Territory. Coordinates of the place of discovery are: 53º19'N lat, 116º19'E long. The territory is located in the zone of the passage of the Tunguska meteorite and the Vitim bollid, 25 km from the hunting village of Green Lake. The body is named “Ilekta” after the nearest stream flowing into the Nercha River. The composition and magnetic properties of the exotic find have been determined. It is established that its main mass is composed of iron silicide, gupesiite Fe3Si (zussite?) and contains inclusions of needle-like rhabdite. On the surface, the body is covered with a melting crust, with signs of boiling, a bubbly structure and a film of clay minerals of terrestrial origin. In the molten porous crust, eutectic-schreibersite-gupeiite is observed, and rare titanium carbide crystals are also noted. The magnetic susceptibility of the samples is not uniform (286.6 - 461.8 10-6E-06 m3/kg). It is assumed that a drop of melt separated from the flying space body, and experienced overheating and boiling of the surface layer in the dense layers of the atmosphere.

Function fitting for modeling seasonal normalized difference vegetation index time series and early forecasting of soybean yield

Forecasting crop yields based on remote sensing data is one of the most important tasks in agriculture.Soybean is the main crop in the Russian Far East.It is desirable to forecast soybean yield as early as possible while maintaining high accuracy.This study aimed to investigate seasonal time series of the normalized difference vegetation index(NDVI) to achieve early forecasting of soybean yield.This research used data from the Moderate Resolution Image Spectroradiometer(MODIS),an arable-land mask obtained from the VEGA-Science web service,and soybean yield data for 2008-2017 for the Jewish Autonomous Region(JAR) districts.Four approximating functions were fitted to model the NDVI time series:Gaussian,double logistic(DL),and quadratic and cubic polynomials.In the period from calendar weeks 22-42(end of May to mid-October),averaged over two districts,the model using the DL function showed the highest accuracy(mean absolute percentage error-4.0%,root mean square error(RMSE)-0.029,P <0.01).The yield forecast accuracy of prediction in the period of weeks 25-30 in JAR municipalities using the parameters of the Gaussian function was higher(P <0.05) than that using the other functions.The mean forecast error for the Gaussian function was 14.9% in week 25(RMSE was0.21 t ha) and 5.1%-12.9% in weeks 26-30(RMSE varied from 0.06 to 0.15 t ha) according to the2013-2017 data.In weeks 31-32,the error was 5.0%-5.4%(RMSE was 0.07 t ha) using the Gaussian parameters and 7.4%-7.7%(RMSE was 0.09-0.11 t ha) for the DL function.When the method was applied to municipal districts of other soy-producing regions of the Russian Far East.RMSE was0.14-0.32 t hain weeks 25-26 and did not exceed 0.20 t hain subsequent weeks.

Microsatellite Analysis of <i>Panax ginseng</i>Natural Populations in Russia

Panax ginseng C.A. Meyer is an endangered species in Russia. To restore this species, effective protective measures, including the reintroduction into favorable habitats, must be worked out considering the specificity of genetic structure of ginseng populations. One hundred and thirty-nine P. ginseng plants were collected from the forests of nine administrative areas of Primorsky Territory of Russia and transferred to a collection nursery for further investigation. Microsatellite markers were used to study the genetic diversity and the genetic structure of ginseng populations. For populations studied with SSR, the number of observed alleles was ranging from 15 to 25, allelic richness from 1.83 to 3.04, polymorphic loci from 62.5% to 87.7%, observed heterozygosity from 0.410 to 0.512 (an average of 0.453) and expected heterozygosity from 0.304 to 0.479, with an average of 0.393. The values of the inbreeding coefficient within populations (Fis) ranged from -0.447 to 0.056, and their average value was -0.296. Genetic differentiation among populations was significant (Fst = 0.115) but an isolation-by-distance pattern was not detected. UPGMA and MS-tree confirmed the presence of genetic structure within P. ginseng and visualized genetic relationships of populations with similar pattern. STRUCTURE analysis revealed the genetic admixture between different ginseng populations. It was established with SSR markers that P. ginseng still preserves substantial genetic resources although all populations are largely exhausted. Because ginseng populations are significantly differentiated all of them should be restored. Considering the admixture of ginseng populations it would be advisable to apply the individual assignment test to verify the content of indigenous populations and to identify the "true" population plants to serve as stock material for reintroduction.

Growth of Micropropagated Solanum tuberosum L.Plantlets under Artificial Solar Spectrum and Different Mono-and Polychromatic LED Lights

In agriculture,LED light sources have increasingly replaced the standard luminescent lamps and have acquired an important role in plant micropropagation.We studied the effect of different light sources such as narrow-band LEDs(bright blue,blue,green,yellow,deep red,and red)and wide-band LEDs(cold white,white,warm white,full spectrum,and an artificial solar spectrum sun box constructed by us)on development of potato plantlets in vitro.White luminescent lamps were used as a control.The light intensity of 49μmol·m^(-2)·s^(-1)was provided in all light treatments.We showed that the long-wave narrow-band light treatments were inapplicable for potato micropropagation,because plantlets were weak with small leaves,inhibited roots,and significantly elongated stems.Blue lights provided growth of shortened plantlets with large leaves,well-growing roots,and abundant green mass.The chlorophyll content was lower under blue and bright blue light and was at the same level in the remained treatments.Significant differences in the stomatal apparatus development were observed depending on the light source.These differences were not always reflected in the plantlet phenotype:e.g.,plantlets under blue and bright blue lights showed no differences in any characteristics except stomatal density and size of stomatal guard cells.We found no significant effect of blue light portion in the white lights and full spectrum on plantlet growth.An artificial solar spectrum sun box was the most suitable for potato micropropagation,because it supported the development of plantlets with good fitness,uniform internodes length,abundant roots and green mass accumulation.

Polyphyletic Origin of Ornamental Goldfish

Mitochondrial DNA fragment of cytb was compared in all species Carassius auratus complex and three forms of ornamental goldfish. It is shown that the phylogenetic relationships between complex species correspond to the existing views, based on mtDNA data and geographical distribution. All forms of ornamental goldfish have a monophyletic origin from Chinese goldfish C. auratus auratus. The analysis showed that three nuclear genes (rps7, GH1 and Rh) in the two forms of ornamental goldfish (Oriental twintail goldfish and Chinese Ranchu) were almost identical C. auratus auratus genes, while all three gene in another more simple form of goldfish (common goldfish) were highly homologous to carp Cyprinus carpio nuclear genes. The obtained data suggested that in the history of aquarium goldfish breeding occurred the stage of distant hybridization between goldfish and common carp. Subsequently, the nuclear genomes of some ornamental forms could be enriched by goldfish genes (a relatively recent form as Oriental twintail goldfish and Chinese Ranchu) or common carp genes (the simplest and most ancient forms like common goldfish) as a result of multidirectional breeding and selection of aquarium goldfish various forms.

Non-classical solutions of a continuum model for rock descriptions

The strain-gradient and non-Euclidean continuum theories are employed for construction of non- classical solutions of continuum models. The linear approximation of both models＇ results in identical structures in terms of their kinematic and stress characteristics. The solutions obtained in this study exhibit a critical behaviour with respect to the external loading parameter. The conclusions are obtained based on an investigation of the solution for the scalar curvature in the non-Euclidean continuum theory, The proposed analysis enables us to use different theoretical approaches for description of rock critical behaviour under different loading conditions.

A method to predict rockburst using temporal trend test and its application

Rockbursts have become a significant hazard in underground mining,underscoring the need for a robust early warning model to ensure safety management.This study presents a novel approach for rockburst prediction,integrating the Mann-Kendall trend test(MKT)and multi-indices fusion to enable real-time and quantitative assessment of rockburst hazards.The methodology employed in this study involves the development of a comprehensive precursory index library for rockbursts.The MKT is then applied to analyze the real-time trend of each index,with adherence to rockburst characterization laws serving as the warning criterion.By employing a confusion matrix,the warning effectiveness of each index is assessed,enabling index preference determination.Ultimately,the integrated rockburst hazard index Q is derived through data fusion.The results demonstrate that the proposed model achieves a warning effectiveness of 0.563 for Q,surpassing the performance of any individual index.Moreover,the model’s adaptability and scalability are enhanced through periodic updates driven by actual field monitoring data,making it suitable for complex underground working environments.By providing an efficient and accurate basis for decision-making,the proposed model holds great potential for the prevention and control of rockbursts.It offers a valuable tool for enhancing safety measures in underground mining operations.

Two lineages of bivalve transmissible neoplasia affect the blue mussel Mytilus trossulus Gould in the subarctic Sea of Okhotsk

There are increasing findings of the bivalve transmissible neoplasia derived from the Pacific mussel Mytilus trossulus(MtrBTN)in populations of different Mytilus species worldwide.The Subarctic is an area where this disease has not yet been sought despite the fact that Mytilus spp.are widespread there,and M.trossulus itself is a boreal species.We used flow cytometry of the hemolymph,hemocytology,and histology to diagnose disseminated neoplasia in a sample of M.trossulus from Magadan in the subarctic Sea of Okhotsk.Neoplasia was identified in 11 of 214 mussels studied.Using mtDNA COI sequencing,we revealed genotypes identical or nearly identical to known MtrBTN ones in the hemolymph of most of the diseased mussels.Both MtrBTN evolutionary lineages have been identified,the widespread MtrBTN2,and MtrBTN1,so far only known from M.trossulus in British Columbia on the other side of the Pacific from Magadan.In addition,MtrBTN2 was represented by 2 common diverged mtDNA haplolineages.These conclusions were confirmed for selected cancerous mussels by molecular cloning of COI and additional nuclear and mtDNA genes.On the background of high genetic diversity,different cancers were similar in terms of ploidy(range 4.0–5.8 n)and nuclear-to-cell ratio.Our study provides the first description of neoplasia and MtrBTN in mussels from the Sea of Okhotsk and from the Subarctic,of both MtrBTN1 and MtrBTN2 in the same mussel population,and the first direct comparison between these transmissible cancers.

Environmental Changes and Human Impacts on Landscapes near Medieval Steklyanukha-2 Fortress in Russia from Early Iron Age to Modern Times

The development of landscapes in one of the most populated river basins of the southern Russian Far East was studied using pollen and diatom data. The study sites were a multi-layered mountain fortress, Steklyanukha-2, and an Upper Holocene high floodplain sequence of the Steklyanukha River. Buried soil from the fluvial section acts as an environmental archive of the time in which people from the Yankovskaya archeological cultures settled in the river basin. The soil was formed under conditions of decreasing water supply in the valley and prolonged droughts. Findings of pollen Fagopyrum and Urtica signal economic activity in the Early Iron Age.Floodplain lake sediments accumulated from 1.6 to 0.5 kyr, when the valley was actively developed during the Middle Ages. There are signals of the development of secondary birch and oak forests. In the cultural layer of the fortress and lake sediments formed in the Middle Ages, Ambrosia and Xanthium pollens were found and are reliable evidence of agricultural activity in the valley. The pollens of plants typically seen in human-disturbed areas were also found. Indirect evidence of human activity includes non-pollen palynomorphs.The study of diatoms in a depression near a rampart confirmed the archaeologists' assumption that it was used as a water reserve. Pollen spectra from surface soils reflect agricultural activity in the river basin since the second half of the 19th century. The largest amount of pollen of alien and synanthropic plants and weeds, as well as spores of pathogenic fungi and fire indicators, were found here.

Reactive SPS of Al_(2)O_(3)–RE:YAG(RE=Ce;Ce+Gd)composite ceramic phosphors

Ultrafine-grained Al_(2)O_(3)–rare earth:yttrium aluminium garnet(Al_(2)O_(3)–RE:YAG)(RE=Ce;Ce+Gd)composite ceramics were obtained for the first time by reactive spark plasma sintering(SPS)using commercially available initial oxide powders.The effect of key sintering parameters(temperature,dwell time,and external pressure(P_(load)))on densification peculiarities,structural-phase states,and luminescent properties of composites was studied comprehensively.Differences in phase formation and densification between Ce-doped and Ce,Gd-codoped systems were shown.Parameters of reactive SPS,at which there is partial melting with the formation of near-eutectic zones of the Al_(2)O_(3)–YAG system/coexistence of several variations of the YAG-type phase,were established.Pure corundum–garnet biphasic ceramics with an optimal balance between microstructural and luminescence performance were synthesized at 1425℃/30 min/30–60 MPa.The external quantum efficiency(EQE)of the phosphor converters reached 80.7%and 72%with close lifetime of~63.8 ns,similar to those of commercial Ce:YAG materials,which is promising for further applications in the field of high-power white light-emitting diodes(WLEDs)and laser diodes(LDs).

Mortality of Amur tigers:The more things change,the more they stay the same

Poaching as well as loss of habitat and prey are identified as causes of tiger population declines.Although some studies have examined habitat requirements and prey availability,few studies have quantified cause-specific mortality of tigers.We used cumulative incidence functions(CIFs)to quantify cause-specific mortality rates of tigers,expanding and refining earlier studies to assess the potential impact of a newly emerging disease.To quantify changes in tiger mortality over time,we re-examined data first collected by Goodrich et al.(2008;study period 1:1992–2004)as well as new telemetry data collected since January 2005(study period 2:2005–2012)using a total of 57 tigers(27 males and 30 females)monitored for an average of 747 days(range 26–4718 days).Across the entire study period(1992 to 2012)we found an estimated average annual survival rate of 0.75 for all tigers combined.Poaching was the primary cause of mortality during both study periods,followed by suspected poaching,distemper and natural/unknown causes.Since 2005,poaching mortality has remained relatively constant and,if combined with suspected poaching,may account for a loss of 17–19%of the population each year.Canine distemper virus(CDV)may be an additive form of mortality to the population,currently accounting for an additional 5%.Despite this relatively new source of mortality,poaching remains the main threat to Amur tiger survival and,therefore,population growth.