34 research outputs found

    Luminescence evidence for bulk and surface excitons in free xenon clusters

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    Cathodoluminescence spectra of free xenon clusters produced by condensation of xenon-argon gas mixtures in supersonic jets expanding into vacuum were studied. By varying initial experimental parameters, including xenon concentration, we could obtain clusters with a xenon core (300-3500 atoms) covered by an argon outer shell as well as shell-free xenon clusters (about 1500 atoms). The cluster size and temperature (about 40 K for both cases) were measured electronographically. Luminescence bands evidencing the existence of bulk and surface excitons were detected for shell-free xenon clusters. The emission from bulk excitons in small clusters is supposed to be due to processes of their multiple elastic reflections from the xenon-vacuum interface. A presence of an argon shell causes extinction of the excitonic bands. In addition, some new bands were found which have no analogs for bulk xenon cryosamples.Comment: The final modified version will be published in Phys. Rev. A 76 (2007

    A Tool for GIXRF/XRR simulation and data analysis

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    Ponencia presentada en el Monte Carlo Simulation Tools for X-Ray Imaging and Fluorescence Workshop, 2014The IAEA has developed a beamline end-station facility that it is currently installed at the newly developed XRF beamline of Elettra Sincrotrone Trieste, ItalyThe end-station called Ultra High Vacuum Chamber (UHVC) is a multipurpose facility for applying simultaneously various complementary and advanced variants of X-Ray Spectrometry (XRS) techniques, including: Total Reflection X-ray Fluorescence Analysis (TXRF) Grazing Incidence/Exit XRF analysis (GIXRF- GEXRF) Near Edge X-ray Absorption Fine Structure (NEXAFS) X-ray Reflectometry (XRR) The current development of GIXRF/XRR simulations/analysis tool aims at assisting end-users in data processing and interpretation.Fil: Leani, Juan José. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Leani, Juan José. Nuclear Science and Instrumentation Laboratory, IAEA Laboratories; Austria.Física Atómica, Molecular y Química (física de átomos y moléculas incluyendo colisión, interacción con radiación, resonancia magnética, Moessbauer Efecto.

    Complex analysis of flax seeds composition for breeding programs

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    Single plant selection using complex of seed quality traits requires development and optimization of the methods, which allow qualitative and quantitative analysis applying minimum quantity of seeds. The proposed evaluation scheme of seed composition enables optimal use of seed material for individual plant analysis: oil percentage (Rushkovsky’s extraction method), fatty acid composition (vaporliquid chromatography), protein and ash content (dynamic thermogravimetry), elemental composition (electron probe X-ray fluorescence method). Reproducibility of analytical methods used was assessed by the coefficient of variation, the reproducibility index (ARI) and the convergence of data on seasonal cultivation

    Direct observation of free excitons in luminescence spectra of xenon clusters

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    Luminescence of surface and free bulk excitons is detected in xenon for the first time for substrate-free rare-gas clusters. Xenon clusters were produced by the method of gas condensation in a supersonic jet emitted into vacuum. Optical study was accompanied by electron diffraction measurements to determine the structure of clusters.Comment: The more complete version of the paper is to be published in 'Low Temperature Physics' (2007

    Informative EST-SSR markers for genotyping and intraspecific differentiation of Brassica oleracea var. capitata L.

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    Brassica oleraceae var. capitata L. is characterized by a high level of intraspecific heterogeneity due to some biological features that cause difficulties for breeding creating genetically homogenous forms and maintaining their genetic purity. Microsatellites (SSR) are highly polymorphic markers of plant genomes and represent one of the most effective tools for assessing genetic polymorphism. Among microsatellites, EST-SSR are most interesting, because they are directly linked to the expressed sequences and for that reason are widely used for analysis of genetic diversity and population structure. In this work, we studied the effectiveness of the use of transferable EST-SSR markers for both analyzing white cabbage diversity and genotyping pure lines. As a result, 15 microsatellite loci were characterized for the information content, allelic frequencies and heterogeneity levels. The effective multiallelic markers (Bo20TR, BoDCTD4, BoPC34, BoPLD1, BoCalc, BoPC15) with high information content (PIC > 0.7) that could be successfully used for analysis of inter- and intravarietal polymorphism in B. oleracea var. capitata were identified. It has been shown that intervarietal polymorphism expressed as the allelic diversity of EST SSR loci greatly facilitates varietal identification and typing of individual plants for breeding purposes. Based on the SSR-evaluation and subsequent clustering, the genetic structure of the breeding collection was identified, which showed that most experimental forms, in spite of different origin, have a common ancestral genetic basis. The identified donors of rare alleles could potentially be a source of valuable genetic segregation for further B. oleracea breeding improvement

    An IAEA Multi-technique X-ray Spectrometry End-station at Elettra Sincrotrone Trieste: Benchmarking Results and Interdisciplinary Applications

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    The International Atomic Energy Agency (IAEA) jointly with the Elettra Sincrotrone Trieste (EST) operates a multipurpose X-ray spectrometry endstation at the X-ray Fluorescence beamline (10.1L). The facility has been available to external users since the beginning of 2015 through the peer-review process of EST. Using this collaboration framework, the IAEA supports and promotes synchrotron-radiation-based research and training activities for various research groups from the IAEA Member States, especially those who have limited previous experience and resources to access a synchrotron radiation facility. This paper aims to provide a broad overview about various analytical capabilities, intrinsic features and performance figures of the IAEA X-ray spectrometry endstation through the measured results. The IAEA-EST endstation works with monochromatic X-rays in the energy range 3.7-14keV for the Elettra storage ring operating at 2.0 or 2.4GeV electron energy. It offers a combination of different advanced analytical probes, e.g. X-ray reflectivity, X-ray absorption fine-structure measurements, grazing-incidence X-ray fluorescence measurements, using different excitation and detection geometries, and thereby supports a comprehensive characterization for different kinds of nanostructured and bulk materials.A broad overview of the various analytical capabilities, intrinsic features and performance figures of the IAEA X-ray spectrometry endstation operated at the X-ray Fluorescence beamline of Elettra Sincrotrone Trieste is given, and different applications are demonstrated to familiarize the user community with the applicable intersdisciplinary research.Fil: Karydas, A.. International Atomic Energy Agency; Austria. National Centre for Scientific Research "Demokritos"; GreciaFil: Czyzycki, M.. International Atomic Energy Agency; Austria. AGH University of Science and Technology. Faculty of Physics and Applied Computer Science ; PoloniaFil: Leani, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. International Atomic Energy Agency; AustriaFil: Migliori, A.. International Atomic Energy Agency; Austria. Nuclear Spectrometry And Appications Lab, Iaea. Onu; AustriaFil: Osán, J.. Hungarian Academy of Sciences Centre for Energy Research; Hungría. International Atomic Energy Agency; AustriaFil: Bogovac, M.. International Atomic Energy Agency; AustriaFil: Wrobel, P.. AGH University of Science and Technology. Faculty of Physics and Applied Computer Science ; PoloniaFil: Vakula, N.. International Atomic Energy Agency; AustriaFil: Padilla Alvarez, R.. International Atomic Energy Agency; AustriaFil: Menk, Ralf Hendrik. Elettra-Sincrotrone Trieste SCpA di Interesse Nazionale; Italia. University of Saskatchewan; CanadáFil: Gol, M. G.. Iranian Light Source Facility; IránFil: Antonelli, M.. Istituto Nazionale di Fisica Nucleare; Italia. Elettra-Sincrotrone Trieste SCpA di Interesse Nazionale; ItaliaFil: Tiwari, M. K.. Raja Ramanna Centre for Advanced Technology; IndiaFil: Caliri, C.. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Vogel Mikuš, K.. Jozef Stefan Institute; Eslovenia. University of Ljubljana; EsloveniaFil: Darby, I.. Elettra-Sincrotrone Trieste SCpA di Interesse Nazionale; Italia. International Atomic Energy Agency; AustriaFil: Kaiser, R.. International Atomic Energy Agency; Austri

    Генетический анализ останков из погребений XVII–XVIII вв. костела Божьего Тела в Несвиже

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    During archaeological excavation in the territory of the Corpus Christi Church in Nesvizh, the regular burials dated to the 17th–18th centuries were discovered. The genetic material extracted from the bones of seven unidentified individuals was analyzed using the forensic genetics approaches, including STR profiling and DNA phenotyping. The genetic examination revealed that the remains of three samples (#1, #2, #6) belonged to women, and the four others (#3, #4, #5, and #7) belonged to men. Autosomal STR-data and Y-chromosomal profiles were obtained for five samples. The kinship analysis excluded that woman #1 and men #3, #4, #5, #7 were first-degree relatives. According to the Y-STR profiles, men #3, #4, #7 referred to the haplogroup R1a, the haplotype of individual #5 corresponded to I2. The both haplogroups are widely represented in Eastern Europe, which, with a high degree of probability, suggests the Slavic origin of the individuals under investigation. To predict eye and hair color, we used the HIrisPlex DNA phenotyping system. The analysis gave the satisfactory results for woman #1 and man #7. In correspondence to the allelic variants of the 24 SNP system, woman #1 had an intermediate type of iris pigmentation and dark blond hair (p = 0.635) with dark shade (0.639), light skin tone, low tendency to sunburn, and a high probability of freckles and pigmented spots of the skin. For male #7, the HIrisPlex model predicted blue eye color with a high probability (p = 0.915), as well as blond hair color (p = 0.915) and light hair color shade (p = 0.962). Our data allow us to conclude that the unknown individuals under investigation have significant genetical and phenotypical similarity with the modern Belarusian population.В ходе археологических раскопок на территории костела Божьего Тела в Несвиже были обнаружены регулярные захоронения XVII–XVIII вв. Костные останки семи неизвестных лиц подвергнуты изучению с использованием подходов генетической экспертизы и ДНК-фенотипирования. Анализ маркеров половой принадлежности показал, что останки индивидов № 1, 2 и 6 принадлежат женщинам, индивидов № 3, 4, 5 и 7 – мужчинам. В ходе исследования STR маркеров аутосомной и Y-хромосомной ДНК были получены индивидуальные профили для пяти индивидов и исключено родство первого порядка между женщиной № 1 и мужчинами № 3, 4, 5 и 7. Согласно Y-STR профилям мужчины № 3, 4, 7 относятся к гаплогруппе R1a, гаплотип индивида № 5 соответствует гаплогруппе I2, которые широко представлены на территории Восточной Европы, что с высокой долей вероятности позволяет предполагать славянское происхождение исследуемых лиц. Для установления фенотипических особенностей индивидов использовали систему HIrisPlex, генотипирование в которой позволило получить удовлетворительные результаты для женщины № 1 и мужчины № 7. Данные оценки аллельных вариантов 24 SNP системы свидетельствуют в пользу славянского типа их внешности: с высокой вероятностью женщина № 1 имела зеленые глаза, темно-русые волосы и светлый оттенок кожи; мужчина № 7 являлся светлым шатеном с голубыми глазами. Совокупность полученных данных позволяет сделать вывод, что исследуемые останки принадлежат представителям населения, генетически и фенотипически схожего с современной белорусской популяцией

    Вариация пигментации радужки глаз белорусской популяции в связи с полиморфизмом генов HERC2 и OCA2

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    The human genetic phenotyping is one of the most intensely developing area of forensic genetics. Externally visible traits, including eye color, can be predicted by analyzing single nucleotide polymorphisms with a high predictive rate. We studied the polymorphisms rs12913832 and rs1800407 in the HERC2 and OCA2 genes, respectively, to evaluate its prognostic availability in relation to the iris pigmentation of the Belarusian population. For this, both eye images and DNA samples were collected from 314 individuals to analyze the key polymorphisms by the TaqMan assay. Our data confirmed a relevance of rs12913832:A>G and rs1800407:G>A in the prediction context. The highest values of the sensitivity (SE = 0.94) and the specificity (SP = 0.90) were obtained for rs12913832, demonstrating the high efficiency of this marker as a classifier of phenotypic groups. The presence of the ancestral dominant allele rs12913832-A causes a dark (brown) iris pigmentation, how- ever, the heterozygous state rs12913832:GA includes a range of mixed variants. The predictive value of rs1800407 for the genetic phenotyping is highly significant (SE = 0.98), but has a low specificity (SP = 0.14), thus rs1800407, not being an effective classifier, can be used as an auxiliary in the eye color predictive model. The analysis of a cumulative impact of the both poly- morphisms on the iris color variation shows their high prospects for the genetic phenotyping of the Belarusian population.Генетическое фенотипирование человека – новое, интенсивно развивающееся направление криминалистической генетики. Исследование генетических основ цветовой вариации глаз является одним из наиболее перспективных среди подходов, нацеленных на установление облика неизвестного индивида по характеристикам его ДНК. В данной работе проведено изучение полиморфизмов rs12913832 и rs1800407 в генах HERC2 и ОСA2 соответственно в связи с пигментацией радужки глаз белорусской популяции и дана оценка их прогностической эффективности для генетического фенотипирования. Полученные данные подтвердили значимый вклад в цветовую вариацию радужки глаз rs12913832:A>G и rs1800407:G>A. Высокие значения чувствительности (SE = 0,94) и специфичности (SP = 0,90) были получены для rs12913832, подтвердив эффективность данного маркера для использования в качестве классификатора фенотипических групп. Наличие предкового доминантного аллеля rs12913832-A обусловливает темную пигментацию радужки, однако гетерозиготное носительство rs12913832:GA включает значительный спектр смешанных вариантов. Однонуклеотидный полиморфизм rs1800407 характеризуется высокой чувствительностью (SE = 0,98), однако имеет низкое значение специфичности (SP = 0,14), следовательно, данный маркер, не являясь эффективным классификатором, может использоваться только как вспомогательный инструмент для предсказания цвета глаз. Оценка совокупного вклада изученных полиморфизмов в цветовую вариацию радужки глаз белорусской популяции показывает их высокий прогностический потенциал для генетического фенотипирования
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