Phage detection in the rhizosphere of higher antarctic plants using transmission electron microscopy

This work is focused on electron microscopy of soil samples from root zone of higher Antarctica plants Deschampsia antarctica and Colobanthus quitensis for detection of bacteriophages. Here we compared several techniques and proposed optimal method for isolation of phage suspensions from the substrate. For the first time, the biodiversity of bacteriophages and virus-like particles (VLPs) in the root zone of Antarctic plants has been evaluated. According to morphological description, the dimensions and taxonomic position of several bacteriophages were elucidated. Possible reasons for degradation of virus particles observed during the microscopy studies have been suggested.Дана робота присвячена електронномікроскопічному аналізові зразків ґрунту прикореневої зони вищих антарктичних рослин Deschampsia antarctica та Colobanthus quitensis з метою виявлення бактеріофагів. Порівняно та підібрано оптимальний метод виділення вірусних суспензій з субстрату. Вперше проаналізовано різноманіття вірусів бактерій та вірусоподібних часток у прикореневому ґрунті антарктичних рослин. За результатами електронної мікроскопії виявлено велику кількість фагових та вірусоподібних часток. За морфологічним описом визначено таксономічну приналежність окремих виявлених бактеріофагів та їхні розміри. Розглянуто можливі причини деградації вірусних часток, виявлених при ЕМ дослідженні.Данная работа посвящена электронномикроскопическому анализу образцов почвы прикорневой зоны высших антарктических растений Deschampsia antarctica и Colobanthus quitensis с целью обнаружения бактериофагов. Проведено сравнение и подобран оптимальный метод выделения вирусных суспензий из субстрата. Впервые проанализировано разнообразие вирусов бактерий и вирусоподобных частиц в прикорневой почве антарктических растений. Согласно морфологическому описанию, определены таксономическая принадлежность отдельных обнаруженных бактериофагов и их размеры. Рассмотрены возможные причины деградации вирусных частиц, обнаруженных при микроскопических исследованиях

Екологічний аудит меліорованих агроландшафтів в сучасних умовах

Проведен анализ проблемы экологического аудита мелиорированных агроландшафтов с целью стабилизации их экологического состояния и безопасного использования в условиях трансформации земельных отношений и рационального землепользования.Проведено аналіз проблеми екологічного аудиту меліорованих агроландшафтів з метою стабілізації їх екологічного стану та безпечного користування в умовах трансформації земельних відносин і раціонального землекористування

Search for long-lived superheavy eka-tungsten with radiopure ZnWO4_4 crystal scintillator

The data collected with a radioactively pure ZnWO$_4$ crystal scintillator (699 g) in low background measurements during 2130 h at the underground (3600 m w.e.) Laboratori Nazionali del Gran Sasso (INFN, Italy) were used to set a limit on possible concentration of superheavy eka-W (seaborgium Sg, Z = 106) in the crystal. Assuming that one of the daughters in a chain of decays of the initial Sg nucleus decays with emission of high energy $\alpha$ particle ($Q_\alpha > 8$ MeV) and analyzing the high energy part of the measured $\alpha$ spectrum, the limit N(Sg)/N(W) < 5.5 $\times$ 10$^{-14}$ atoms/atom at 90% C.L. was obtained (for Sg half-life of 10$^9$ yr). In addition, a limit on the concentration of eka-Bi was set by analysing the data collected with a large BGO scintillation bolometer in an experiment performed by another group [L. Cardani et al., JINST 7 (2012) P10022]: N(eka-Bi)/N(Bi) < 1.1 $\times$ 10$^{-13}$ atoms/atom with 90% C.L. Both the limits are comparable with those obtained in recent experiments which instead look for spontaneous fission of superheavy elements or use the accelerator mass spectrometry.Comment: 9 pages, 2 figures; in press on Physica Script

Investigation of rare nuclear decays with BaF2_2 crystal scintillator contaminated by radium

The radioactive contamination of a BaF$_2$ scintillation crystal with mass of 1.714 kg was measured over 101 hours in the low-background DAMA/R&D set-up deep underground (3600 m w.e.) at the Gran Sasso National Laboratories of INFN (LNGS, Italy). The half-life of $^{212}$Po (present in the crystal scintillator due to contamination by radium) was measured as $T_{1/2}(^{212}$Po) = 298.8$\pm$0.8(stat.)$\pm$1.4(syst.) ns by analysis of the events' pulse profiles. The $^{222}$Rn nuclide is known as 100% decaying via emission of $\alpha$ particle with $T_{1/2}$ = 3.82 d; however, its $\beta$ decay is also energetically allowed with $Q_\beta = 24\pm21$ keV. Search for decay chains of events with specific pulse shapes characteristic for $\alpha$ or for $\beta/\gamma$ signals and with known energies and time differences allowed us to set, for the first time, the limit on the branching ratio of $^{222}$Rn relatively to $\beta$ decay as $B_\beta < 0.13$% at 90% C.L. (equivalent to limit on partial half-life $T_{1/2}^\beta > 8.0$ y). Half-life limits of $^{212}$Pb, $^{222}$Rn and $^{226}$Ra relatively to $2\beta$ decays are also improved in comparison with the earlier results.Comment: 10 pages, 9 figures, 2 table

GISTECHNOLOGY FOR THE MONITORING OF SHARKA DISEASE IN THE ODESSA REGION

Plant virus causes many important plant diseases and are responsible for huge losses in crop production and quality in all parts of the world, and consequently, agronomists and plant pathologists have devoted considerable effort toward controlling virus diseases. One the most important virus on many Prunus species, causing great economic losses is Plum pox virus (PPV),casual agent of Sharka disease. Since its discovery, Sharka has been considered as a calamity in stone orchards. The virus has been detected in almost every country where any significant commercial stone fruit cultivation occurs [1]. The virus is entered into the list of regulated pests common in Ukraine. In Ukraine, the total area of PPV spread totals 4013,2764 ha. In Odessa region, 18.5 ha districts are in PPV quarantine. Six hotbeds of PPV infection totalling 28 hectares were found in Odessa region. For the first time in Odessa region, PPV was found on cherry trees. Peach and plum trees are hit equally. In this study, we use geographic information systems technology to identify potential locations in a Odessa region for controlling the spread of Plum pox virus. To our knowledge, this is the first attempt to employ GIS technology for controlling plant diseases in Ukraine. Provided it is properly maintained, the geospatial data, and the ability to generate detailed maps with it, is key to the success of PPV containment. Information management will be a key to improving for controlling the spread of Plum pox virus

Search for double beta decay of 136^{136}Ce and 138^{138}Ce with HPGe gamma detector

Search for double $\beta$ decay of $^{136}$Ce and $^{138}$Ce was realized with 732 g of deeply purified cerium oxide sample measured over 1900 h with the help of an ultra-low background HPGe $\gamma$ detector with a volume of 465 cm$^3$ at the STELLA facility of the Gran Sasso National Laboratories of the INFN (Italy). New improved half-life limits on double beta processes in the cerium isotopes were set at the level of $\lim T_{1/2}\sim 10^{17}-10^{18}$~yr; many of them are even two orders of magnitude larger than the best previous results.Comment: 21 pages, 6 figures, 3 tables; version accepted for publication on Nucl. Phys.

New limits on 2ε2\varepsilon, εβ+\varepsilon\beta^+ and 2β+2\beta^+ decay of 136^{136}Ce and 138^{138}Ce with deeply purified cerium sample

A search for double electron capture ($2\varepsilon$), electron capture with positron emission ($\varepsilon\beta^+$), and double positron emission $2\beta^+$) in $^{136}$Ce and $^{138}$Ce was realized with a 465 cm$^3$ ultra-low background HP Ge $\gamma$ spectrometer over 2299 h at the Gran Sasso underground laboratory. A 627 g sample of cerium oxide deeply purified by liquid-liquid extraction method was used as a source of $\gamma$ quanta expected in double $\beta$ decay of the cerium isotopes. New improved half-life limits were set on different modes and channels of double $\beta$ decay of $^{136}$Ce and $^{138}$Ce at the level of $T_{1/2}>10^{17}-10^{18}$ yr.Comment: 19 pages, 6 figures, 2 table

Improvement of radiopurity level of enriched 116^{116}CdWO4_4 and ZnWO4_4 crystal scintillators by recrystallization

As low as possible radioactive contamination of a detector plays a crucial role to improve sensitivity of a double beta decay experiment. The radioactive contamination of a sample of $^{116}$CdWO$_4$ crystal scintillator by thorium was reduced by a factor $\approx 10$, down to the level 0.01 mBq/kg ($^{228}$Th), by exploiting the recrystallization procedure. The total alpha activity of uranium and thorium daughters was reduced by a factor $\approx 3$, down to 1.6 mBq/kg. No change in the specific activity (the total $\alpha$ activity and $^{228}$Th) was observed in a sample of ZnWO$_4$ crystal produced by recrystallization after removing $\approx 0.4$ mm surface layer of the crystal.Comment: 14 pages, 5 figures and 2 table