Design: immersionnyy stage of project algorithm as metodika of mastering of hypertext

Possibility of the use of technology of the immersive use of hypertext is examined in visual-analog and bibliographic variantsРассматривается возможность применения технологии иммерсивного использования гипертекста в визуально-аналоговом и библиографическом варианта

ИЗУЧЕНИЕ ЗАВИСИМОСТИ ПРАВИЛЬНОСТИ РЕЗУЛЬТАТОВ РЕНТГЕНОФЛУОРЕСЦЕНТНОГО АНАЛИЗА АЭРОЗОЛЕЙ ОТ ЧИСЛА ИЗЛУЧАТЕЛЕЙ, ВЫРЕЗАННЫХ ИЗ ОДНОГО ФИЛЬТРА

The dependence of the accuracy of the X-ray fluorescence analysis (XRF) aerosol results on the number of emitters cut from the single loaded filter was studied. Analyses were performed using the synthetic "filters" in the form of the thin organic films of known analyte contents simulating real aerosol samples collected on the aspiration filters. The diameter of their working surface was 9 cm, which allowed to cut out 5 emitters with 3 cm diameter and to estimate the dependence of error of XRF results when varying the number (n) of emitters from 1 to 5. It was established that when using one emitter (n = 1) cut out from the central part of the inhomogeneous "filter" the error (variation coefficient Vni) in XRF results can reach 40%; when increasing their number the Vnivalue decreases, and when n = 5, it is about 6%, and this corresponds to a random error of the method. However, this procedure substantially increases the labor intensity of the analytical works. The applicability of the emitter was evaluated, consisting of the whole "filter" material of a working surface diameter of9 cm. Under these conditions the background intensity increases, which reduces the contrast of the X-ray spectrum by 6 times. The contrast decreases only by 25% when using double-layer emitters. Thus, for XRF it is recommended to collect the aerosols on filters with 5 cm diameter and to measure the analytical signal from the material of the whole sample.Key words: X-ray fluorescence analysis, aspiration filters loaded by aerosols, sample preparation, synthetic organic films, accuracy in the analysis results.(Russian)DOI: http://dx.doi.org/10.15826/analitika.2016.20.3.002 T.V. Stepanova, A.N. Smagunova, V.S. TolmachevaIrkutsk State University1 K. Marx St., Irkutsk, 664003, Russian Federation Изучена зависимость точности результатов рентгенофлуоресцентного анализа (РФА) аэрозолей от количества излучателей, вырезанных из одного нагруженного фильтра. Исследования выполняли с помощью синтетических «фильтров» в виде тонких органических пленок с известным содержанием аналитов, имитирующих реальные пробы аэрозолей, собранные на аспирационные фильтры. Диаметр их рабочей поверхности составлял 9 см, что позволило вырезать 5 излучателей диаметром 3 см и оценить зависимость погрешности результатов РФА при изменении числа (n) излучателей от 1 до 5. Установлено, что при использовании одного (n = 1) излучателя, вырезанного из центральной части неоднородного «фильтра», погрешность (коэффициент вариации Vнi) результатов РФА может достигать 40 %; с ростом их числа величина Vнi уменьшается, и при n = 5 она составляет примерно 6 %, что соответствует случайной погрешности метода, но этот прием существенно увеличивает трудоемкость аналитических работ. Оценили возможность использования излучателя, состоящего из всего материала «фильтра» с диаметром рабочей поверхности 9 см. В этих условиях возрастает интенсивность фона, что снижает контрастность рентгеновского спектра в 6 раз. При использовании двухслойных излучателей контрастность уменьшается только на 25 %, поэтому для РФА рекомендовали отбирать аэрозоли на фильтры диаметром 5 см и измерять аналитический сигнал от материала всей пробы.Ключевые слова: рентгенофлуоресцентный анализ, нагруженные аэрозолями аспирационные фильтры, приготовление излучателей, синтетические органические пленки, точность результатов анализа.DOI: http://dx.doi.org/10.15826/analitika.2016.20.3.00

MAIN STAGES OF CONTINENTAL CRUST FORMATION IN THE WESTERN ALDAN SHIELD: CONSTRAINTS FROM SM-ND ISOTOPE SYSTEMATICS OF CENOZOIC SANDS IN THE CHARA AND TOKKA BASINS

Previous geochronological and Sm-Nd isotopegeochemical studies have identified the main stages of the Precambrian continental crust formation in the central and eastern parts of the Aldan Shield [Kotov et al., 2006], while its western part (Chara-Olekma Geoblock) has not been adequately investigated yet in this respect.Previous geochronological and Sm-Nd isotopegeochemical studies have identified the main stages of the Precambrian continental crust formation in the central and eastern parts of the Aldan Shield [Kotov et al., 2006], while its western part (Chara-Olekma Geoblock) has not been adequately investigated yet in this respect

Magnetic stratigraphy of the Ordovician in the lower reach of the Kotuy River: the age of the Bysy-Yuryakh stratum and the rate of geomagnetic reversals on the eve of the superchron

© 2017, Pleiades Publishing, Ltd. Until recently, the existing data prevented the geophysicists from accurately dating the Bysy-Yuryakh stratum, which outcrops in the middle reach of the Kotuy River, constraining the time of its formation to a wide interval from the end of the Late Cambrian to the beginning of the Silurian. The obtained paleomagnetic data unambiguously correlate the Bysy-Yuryakh stratum to the Nyaian regional stage and constrain its formation, at least a considerable part of it, by the Tremadocian. This result perfectly agrees with the data on the Bysy-Yuryakh conodonts studied in this work and yields a spectacular example of the successful application of paleomagnetic studies in solving important tasks of stratigraphy and, correspondingly, petroleum geology. Within the Bysy-Yuryakh stratum, we revealed a large normal-polarity interval corresponding to the long ( > 1 Ma) period when the geomagnetic reversals were absent. This result, in combination with the data for the Tremadocian and Middle–Upper Cambrian sequences of the other regions, indicates that (1) the rate of occurrence of the geomagnetic reversals on the eve of the Ordovician Moyero superchron of reversed polarity was at most one reversal per Ma; (2) the superchron does not switch on instantaneously but is preceded by a certain gradual change in the operation conditions of the dynamo mechanism which, inter alia, manifests itself by the reduction of the frequency of geomagnetic reversals with the approach of the superchron. This finding supports the views according to which a process preparing the establishment of the superchrons takes place at the core–mantle boundary

Magnetic stratigraphy of the Ordovician in the lower reach of the Kotuy River: the age of the Bysy-Yuryakh stratum and the rate of geomagnetic reversals on the eve of the superchron

© 2017, Pleiades Publishing, Ltd. Until recently, the existing data prevented the geophysicists from accurately dating the Bysy-Yuryakh stratum, which outcrops in the middle reach of the Kotuy River, constraining the time of its formation to a wide interval from the end of the Late Cambrian to the beginning of the Silurian. The obtained paleomagnetic data unambiguously correlate the Bysy-Yuryakh stratum to the Nyaian regional stage and constrain its formation, at least a considerable part of it, by the Tremadocian. This result perfectly agrees with the data on the Bysy-Yuryakh conodonts studied in this work and yields a spectacular example of the successful application of paleomagnetic studies in solving important tasks of stratigraphy and, correspondingly, petroleum geology. Within the Bysy-Yuryakh stratum, we revealed a large normal-polarity interval corresponding to the long ( > 1 Ma) period when the geomagnetic reversals were absent. This result, in combination with the data for the Tremadocian and Middle–Upper Cambrian sequences of the other regions, indicates that (1) the rate of occurrence of the geomagnetic reversals on the eve of the Ordovician Moyero superchron of reversed polarity was at most one reversal per Ma; (2) the superchron does not switch on instantaneously but is preceded by a certain gradual change in the operation conditions of the dynamo mechanism which, inter alia, manifests itself by the reduction of the frequency of geomagnetic reversals with the approach of the superchron. This finding supports the views according to which a process preparing the establishment of the superchrons takes place at the core–mantle boundary

Palaeozoic carbonates and fossils of the Mendeleev Rise (eastern Arctic): A study of dredged seafloor material

© 2018 Elsevier Ltd Fossiliferous carbonate rocks dredged during the “Arctic-2012” cruise on the Mendeleev Rise (eastern Arctic) provide proof of the presence of Upper Silurian(?)–Middle Devonian, Famennian–Tournaisian, Bashkirian–Kasimovian, Gshelian–lower Asselian(?) and Kungurian–Kazanian carbonate deposits. The wide spectrum of facies includes deposits of both photic zone (with fusulinids, algae, relicts of microbial and coral reefs) and deeper dysphotic areas (with trilobites, deep-water tentaculitids and ostracods). The results obtained suggest that there were at least three periods of carbonate platform sedimentation during the latest Silurian(?) to Permian. The Late Silurian?–Devonian biota do not show biogeographical differentiation, but rather are distributed globally. Shallow-water foraminifera and some algae of early Pennsylvanian–basal Cisuralian age belong to the warm-water province. These forms are unknown in the Moscovian–Permian of the Boreal Realm (Taimyr, New Siberian Islands, Verkhoyanie, Omolon Massif) but are typical for Alaska and Arctic Canada, Wrangel Island, Chukotka, Polar Urals and Svalbard. The disappearance of warm-water biota during late Artinskian-Kungurian times led to a subsequent predominance of smaller foraminifera: this assemblage with Protonodosaria is widely distributed in Permian deposits of Novaya Zemlya, Urals, Barents Sea and the eastern Arctic. The warm-water Bashkirian-Asselian biota suggests that the Mendeleev-Chukotka-Wrangel block was a low-latitude shallow basin with predominant carbonate sedimentation, being part of the Arctida supercontinent, connected temporarily with the eastern margin of Laurasia (Chukcha-Alaska block)

Comparative cytogenetics of anembryonic pregnancies and missed abortions in human

Miscarriage is an important problem in human reproduction, affecting 10–15 % of clinically recognized pregnancies. The cases of embryonic death can be divided into missed abortion (MA), for which the ultrasound sign of the embryo death is the absence of cardiac activity, and anembryonic pregnancy (AP) without an embryo in the gestational sac. The aim of this study was to compare the frequency of chromosomal abnormalities in extraembryonic tissues detected by conventional cytogenetic analysis of spontaneous abortions depending on the presence or absence of an embryo. This is a retrospective study of 1551 spontaneous abortions analyzed using GTG-banding from 1990 to 2022 (266 cases of AP and 1285 cases of MA). A comparative analysis of the frequency of chromosomal abnormalities and the distribution of karyotype frequencies depending on the presence of an embryo in the gestational sac was carried out. Statistical analysis was performed using a chi-square test with a p < 0.05 significance level. The total frequency of chromosomal abnormalities in the study was 53.6 % (832/1551). The proportion of abnormal karyotypes in the AP and MA groups did not differ significantly and amounted to 57.1 % (152/266) and 52.9 % (680/1285) for AP and MA, respectively (p = 0.209). Sex chromosome aneuploidies and triploidies were significantly less common in the AP group than in the MA group (2.3 % (6/266) vs 6.8 % (88/1285), p = 0.005 and 4.9 % (13/266) vs 8.9 % (114/1285), p = 0.031, respectively). Tetraploidies were registered more frequently in AP compared to MA (12.4 % (33/266) vs. 8.2 % (106/1285), p = 0.031). The sex ratio among abortions with a normal karyotype was 0.54 and 0.74 for AP and MA, respectively. Thus, although the frequencies of some types of chromosomal pathology differ between AP and MA, the total frequency of chromosomal abnormalities in AP is not increased compared to MA, which indicates the need to search for the causes of AP at other levels of the genome organization, including microstructural chromosomal rearrangements, monogenic mutations, imprinting disorders, and epigenetic abnormalities

The study of the accuracy dependence of xrf aerosol results on the number of emitters cut from a single filter

The dependence of the accuracy of the X-ray fluorescence analysis (XRF) aerosol results on the number of emitters cut from the single loaded filter was studied. Analyses were performed using the synthetic “filters” in the form of the thin organic films of known analyte contents simulating real aerosol samples collected on the aspiration filters. The diameter of their working surface was 9 cm, which allowed to cut out 5 emitters with 3 cm diameter and to estimate the dependence of error of XRF results when varying the number (n) of emitters from 1 to 5. It was established that when using one emitter (n = 1) cut out from the central part of the inhomogeneous “filter” the error (variation coefficient Vni) in XRF results can reach 40%; when increasing their number the Vnivalue decreases, and when n = 5, it is about 6%, and this corresponds to a random error of the method. However, this procedure substantially increases the labor intensity of the analytical works. The applicability of the emitter was evaluated, consisting of the whole “filter” material of a working surface diameter of 9 cm. Under these conditions the background intensity increases, which reduces the contrast of the X-ray spectrum by 6 times. The contrast decreases only by 25% when using double-layer emitters. Thus, for XRF it is recommended to collect the aerosols on filters with 5 cm diameter and to measure the analytical signal from the material of the whole sample.Изучена зависимость точности результатов рентгенофлуоресцентного анализа (РФА) аэро- золей от количества излучателей, вырезанных из одного нагруженного фильтра. Исследования выполняли с помощью синтетических «фильтров» в виде тонких органических пленок с известным содержанием аналитов, имитирующих реальные пробы аэрозолей, собранные на аспирационные фильтры. Диаметр их рабочей поверхности составлял 9 см, что позволило вырезать 5 излучате- лей диаметром 3 см и оценить зависимость погрешности результатов РФА при изменении числа (n) излучателей от 1 до 5. Установлено, что при использовании одного (n = 1) излучателя, вырезанно- го из центральной части неоднородного «фильтра», погрешность (коэффициент вариации Vнi ) ре- зультатов РФА может достигать 40 %; с ростом их числа величина Vнi уменьшается, и при n = 5 она составляет примерно 6 %, что соответствует случайной погрешности метода, но этот прием суще- ственно увеличивает трудоемкость аналитических работ. Оценили возможность использования излучателя, состоящего из всего материала «фильтра» с диаметром рабочей поверхности 9 см. В этих условиях возрастает интенсивность фона, что снижает контрастность рентгеновского спектра в 6 раз. При использовании двухслойных излучателей контрастность уменьшается только на 25 %, поэтому для РФА рекомендовали отбирать аэрозоли на фильтры диаметром 5 см и измерять ана- литический сигнал от материала всей пробы

Six pelagic seabird species of the North Atlantic engage in a fly-and-forage strategy during their migratory movements

Funding Information: We thank all the fieldworkers for their hard work collecting data. Funding for this study was provided by the Norwegian Ministry for Climate and the Environment, the Norwegian Ministry of Foreign Affairs and the Norwegian Oil and Gas Association along with 8 oil companies through the SEATRACK project (www. seapop. no/ en/ seatrack). Fieldwork in Norwegian colonies (incl. Svalbard and Jan Mayen) was supported by the SEAPOP program (www.seapop.no, grant no. 192141). The French Polar Institute (IPEV project 330 to O.C.) supported field operation for Kongsfjord kittiwakes. The work on the Isle of May was also supported by the Natural Environment Research Council (Award NE/R016429/1 as part of the UK-SCaPE programme delivering National Capability). We thank Maria Bogdanova for field support and data processing. Finally, we thank 3 anonymous reviewers for their help improving the first version of the manuscript.Peer reviewedPublisher PD

Expression of the NUP153 and YWHAB genes from their canonical promoters and alternative promoters of the LINE-1 retrotransposon in the placenta of the first trimester of pregnancy

The placenta has a unique hypomethylated genome. Due to this feature of the placenta, there is a potential possibility of using regulatory elements derived from retroviruses and retrotransposons, which are suppressed by DNA methylation in the adult body. In addition, there is an abnormal increase in the level of methylation of the LINE-1 retrotransposon in the chorionic trophoblast in spontaneous abortions with both normal karyotype and aneuploidy on different chromosomes, which may be associated with impaired gene transcription using LINE-1 regulatory elements. To date, 988 genes that can be expressed from alternative LINE-1 promoters have been identified. Using the STRING tool, genes (NUP153 and YWHAB) were selected, the products of which have significant functional relationships with proteins highly expressed in the placenta and involved in trophoblast differentiation. This study aimed to analyze the expression of the NUP153 and YWHAB genes, highly active in the placenta, from canonical and alternative LINE-1 promoters in the germinal part of the placenta of spontaneous and induced abortions. Gene expression analysis was performed using real-time PCR in chorionic villi and extraembryonic mesoderm of induced abortions (n = 10), adult lymphocytes (n = 10), spontaneous abortions with normal karyotype (n = 10), and with the most frequent aneuploidies in the first trimester of pregnancy (trisomy 16 (n = 8) and monosomy X (n = 6)). The LINE-1 methylation index was assessed in the chorionic villi of spontaneous abortions using targeted bisulfite massive parallel sequencing. The level of expression of both genes from canonical promoters was higher in blood lymphocytes than in placental tissues (p < 0.05). However, the expression level of the NUP153 gene from the alternative LINE-1 promoter was 17 times higher in chorionic villi and 23 times higher in extraembryonic mesoderm than in lymphocytes (p < 0.05). The expression level of NUP153 and YWHAB from canonical promoters was higher in the group of spontaneous abortions with monosomy X compared to all other groups (p < 0.05). The LINE-1 methylation index negatively correlated with the level of gene expression from both canonical (NUP153 – R = –0.59, YWHAB – R = –0.52, p < 0.05) and alternative LINE-1 promoters (NUP153 – R = –0.46, YWHAB – R = –0.66, p < 0.05). Thus, the observed increase in the LINE-1 methylation index in the placenta of spontaneous abortions is associated with the level of expression of the NUP153 and YWHAB genes not only from alternative but also from canonical promoters, which can subsequently lead to negative consequences for normal embryogenesis