570 research outputs found

    Anomalous population of 10^{10}He states in reactions with 11^{11}Li

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    Structure with the lowest energy observed in the 10^{10}He spectrum populated in the proton knockout reaction with 11^{11}Li beam has a peak at 1.2βˆ’1.51.2-1.5 MeV. This peak is usually interpreted as a resonant 0+0^+ ground state of 10^{10}He. Our theoretical calculations indicate that this peak is likely to be a pileup of 1βˆ’1^-, 0+0^+, and 2+2^+ excitations with very similar shapes. %We predict a very specific nature of the 1βˆ’1^- excitation in 10^{10}He. Moreover, the ``soft'' 1βˆ’1^- excitation appears to be the lowest one in energy. Such an anomalous continuum response is traced to the halo structure of 11^{11}Li providing extreme low energy shift to all the expected continuum excitations. Competitions of the initial state structure (ISS) and the final state interaction (FSI) effects on the spectrum and three-body correlations in 10^{10}He are discussed. Analogous effect of the extreme low-energy shift could also be expected in other cases of 2n2n emitters populated in reactions with halo nuclei. Simplified example of the 10^{10}He spectrum in Ξ±\alpha knockout from 14^{14}Be, is given. We also discuss limits on the properties of 9^{9}He stemming from the observed 10^{10}He spectrum.Comment: 10 pages, 13 figure

    Emerg. Infect. Dis

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    The multidrug-resistant (MDR) Salmonella enterica serotype Newport strain that produces CMY-2 Ξ²-lactamase(Newport MDR-AmpC) was the source of sporadic cases and outbreaks in humans in France during 2000–2005. Because this strain was not detected in food animals, it was most likely introduced into France through imported food products

    Spatial beam self-cleaning and supercontinuum generation with Yb-doped multimode graded-index fiber taper based on accelerating self-imaging and dissipative landscape

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    We experimentally demonstrate spatial beam self-cleaning and supercontinuum generation in a tapered Ytterbium-doped multimode optical fiber with parabolic core refractive index profile when 1064β€…nm pulsed beams propagate from wider (122β€…Β΅m) into smaller (37β€…Β΅m) diameter. In the passive mode, increasing the input beam peak power above 20β€…kW leads to a bell-shaped output beam profile. In the active configuration, gain from the pump laser diode permits to combine beam self-cleaning with supercontinuum generation between 520-2600β€…nm. By taper cut-back, we observed that the dissipative landscape, i.e., a non-monotonic variation of the average beam power along the MMF, leads to modal transitions of self-cleaned beams along the taper length

    Dependence of the Energy Spectrum of UHE Cosmic Rays on the Latitude of an Extensive Air Shower Array

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    Several energy spectra of cosmic rays with energies E_0 \geq 10^17 eV measured at the Yakutsk EAS, AGASA, Haverah Park, HiRes, Auger, and SUGAR arrays are considered. It is shown that the fairly good mutual agreement of the spectrum shapes can be achieved if the energy of each spectrum is multiplied by a factor K specific for each spectrum. These factors exhibit a pronounced dependence on the latitude of the above-mentioned arrays.Comment: 4 pages, 4 figure

    Three-body correlations in direct reactions: Example of 6^{6}Be populated in (p,n)(p,n) reaction

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    The 6^{6}Be continuum states were populated in the charge-exchange reaction 1^1H(6^{6}Li,6^{6}Be)nn collecting very high statistics data (∼5Γ—106\sim 5 \times 10^6 events) on the three-body Ξ±\alpha+pp+pp correlations. The 6^{6}Be excitation energy region below ∼3\sim 3 MeV is considered, where the data are dominated by contributions from the 0+0^+ and 2+2^+ states. It is demonstrated how the high-statistics few-body correlation data can be used to extract detailed information on the reaction mechanism. Such a derivation is based on the fact that highly spin-aligned states are typically populated in the direct reactions.Comment: submitted to Physical Review

    10He low-lying states structure uncovered by correlations

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    The 0+ ground state of the 10He nucleus produced in the 3H(8He,p)10He reaction was found at about 2.1Β±0.22.1\pm0.2 MeV (\Gamma ~ 2 MeV) above the three-body 8He+n+n breakup threshold. Angular correlations observed for 10He decay products show prominent interference patterns allowing to draw conclusions about the structure of low-energy excited states. We interpret the observed correlations as a coherent superposition of the broad 1- state having a maximum at energy 4-6 MeV and the 2+ state above 6 MeV, setting both on top of the 0+ state "tail". This anomalous level ordering indicates that the breakdown of the N=8 shell known in 12Be thus extends also to the 10He system.Comment: 5 pages, 5 figure

    Cosmic Rays: The Second Knee and Beyond

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    We conduct a review of experimental results on Ultra-High Energy Cosmic Rays (UHECR's) including measurements of the features of the spectrum, the composition of the primary particle flux and the search for anisotropy in event arrival direction. We find that while there is a general consensus on the features in the spectrum -- the Second Knee, the Ankle, and (to a lesser extent) the GZK Cutoff -- there is little consensus on the composition of the primaries that accompany these features. This lack of consensus on the composition makes interpretation of the agreed upon features problematic. There is also little direct evidence about potential sources of UHECRs, as early reports of arrival direction anisotropies have not been confirmed in independent measurements.Comment: 46 pages, 30 figures. Topical Review to appear in J. Physics

    Alkaloid content variability in the seeds of narrow-leafed lupine accessions from the VIR collection under the conditions of the Russian Northwest

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    Alkaloid content was assessed in the seeds of 59 narrow-leafed lupine (Lupinus angustifolius L.) accessions from the VIR collection in the environments of Leningrad Province. The selected set included accessions of different statuses (wild forms, landraces, and advanced cultivars) and different years of introduction to the collection. Alkaloids were analyzed using gas-liquid chromatography coupled with mass spectrometry. Concentrations of main alkaloids: lupanine, 13-hydroxylupanine, sparteine, angustifoline and isolupanine, and their total content were measured. The total alkaloid content variability identified in the seeds of the studied set of accessions was 0.0015 to 2.017 %. In most cases, the value of the character corresponded to the accession’s status: modern improved cultivars, with the exception of green manure ones, entered the group with the range of 0.0015–0.052 %, while landraces and wild forms showed values from 0.057 to 2.17 %. It is meaningful that the second group mainly included accessions that came to the collection before the 1950s, i. e., before the times when low-alkaloid cultivars were intensively developed. Strong variability of the character across the years was observed in the accessions grown under the same soil and climate conditions in both years. In 2019, the average content of alkaloids in the sampled set was 1.9 times higher than in 2020. An analysis of weather conditions suggested that the decrease in alkaloid content occurred due to a significant increase in total rainfall in 2020. Searching for links between the content of alkaloids and the type of pod (spontaneously non-dehiscent, or cultivated, spontaneously dehiscent, or wild, and intermediate) showed a tendency towards higher (approximately twofold in both years of research) total alkaloid content in the accessions with the wild pod type and the nearest intermediate one compared to those with the pod non-dehiscent without threshing. The correlation between the average total alkaloid content and seed color, reduced to three categories (dark, or wild, light, or cultivated, and intermediate), was significantly stronger in the group with dark seeds (5.2 times in 2019, and 3.7 times in 2020). There were no significant differences in the percentage of individual alkaloids within the total amount either between the years of research or among the groups with different pod types or the groups with different seed coat colors

    Research of the autocytokinins influence on the large intestine’s microflora in gastroenterological patients

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    Π’ΠΈΠ²Ρ‡Π΅Π½ΠΎ Π²ΠΏΠ»ΠΈΠ² ΠΏΡ€Π΅ΠΏΠ°Ρ€Π°Ρ‚Ρ–Π² Π°ΡƒΡ‚ΠΎΡ†ΠΈΡ‚ΠΎΠΊΡ–Π½Ρ–Π² Π½Π° Π·ΠΌΡ–Π½Ρƒ Π±Ρ–ΠΎΠ»ΠΎΠ³Ρ–Ρ‡Π½ΠΈΡ… властивостСй ΠΌΡ–ΠΊΡ€ΠΎΠΎΡ€Π³Π°Π½Ρ–Π·ΠΌΡ–Π², Π²ΠΈΠ΄Ρ–Π»Π΅Π½ΠΈΡ… Π²Ρ–Π΄ Ρ…Π²ΠΎΡ€ΠΈΡ… Π½Π° нСспСцифічний Π²ΠΈΡ€Π°Π·ΠΊΠΎΠ²ΠΈΠΉ ΠΊΠΎΠ»Ρ–Ρ‚. УстановлСно ΡΡ‚ΠΈΠΌΡƒΠ»ΡŽΠ²Π°Π»ΡŒΠ½Ρƒ Π΄Ρ–ΡŽ ΠΏΡ€Π΅ΠΏΠ°Ρ€Π°Ρ‚Ρ–Π² Π°ΡƒΡ‚ΠΎΡ†ΠΈΡ‚ΠΎΠΊΡ–Π½Ρ–Π² Π½Π° ріст прСдставників Π½ΠΎΡ€ΠΌΠ°Π»ΡŒΠ½ΠΎΡ— ΠΌΡ–ΠΊΡ€ΠΎΡ„Π»ΠΎΡ€ΠΈ товстої кишки Ρ‚Π° ΠΏΡ€ΠΈΠ³Π½Ρ–Ρ‡ΡƒΠ²Π°Π»ΡŒΠ½ΠΈΠΉ Π΅Ρ„Π΅ΠΊΡ‚ відносно ΡƒΠΌΠΎΠ²Π½ΠΎ-ΠΏΠ°Ρ‚ΠΎΠ³Π΅Π½Π½ΠΈΡ… ΠΌΡ–ΠΊΡ€ΠΎΠΎΡ€Π³Π°Π½Ρ–Π·ΠΌΡ–Π². З’ясовано, Ρ‰ΠΎ Π°ΡƒΡ‚ΠΎΡ†ΠΈΡ‚ΠΎΠΊΡ–Π½ΠΈ Π½Π΅ Π²ΠΈΡΠ²Π»ΡΡŽΡ‚ΡŒ достовірного Π²ΠΏΠ»ΠΈΠ²Ρƒ Π½Π° Π·ΠΌΡ–Π½Ρƒ антибіотикочутливості ΠΌΡ–ΠΊΡ€ΠΎΠΎΡ€Π³Π°Π½Ρ–Π·ΠΌΡ–Π².Β Π˜Π·ΡƒΡ‡Π΅Π½ΠΎ влияниС ΠΏΡ€Π΅ΠΏΠ°Ρ€Π°Ρ‚ΠΎΠ² Π°ΡƒΡ‚ΠΎΡ†ΠΈΡ‚ΠΎΠΊΠΈΠ½ΠΈΠ² Π½Π° смСну биологичСских свойств ΠΌΠΈΠΊΡ€ΠΎΠΎΡ€Π³Π°Π½ΠΈΠ·ΠΌΠΎΠ², Π²Ρ‹Π΄Π΅Π»Π΅Π½Π½Ρ‹Ρ… ΠΎΡ‚ Π±ΠΎΠ»ΡŒΠ½Ρ‹Ρ… нСспСцифичСский язвСнный ΠΊΠΎΠ»ΠΈΡ‚. УстановлСно ΡΡ‚ΠΈΠΌΡƒΠ»ΠΈΡ€ΡƒΡŽΡ‰Π΅Π΅ дСйствиС ΠΏΡ€Π΅ΠΏΠ°-Ρ€Π°Ρ‚ΠΎΠ² Π°ΡƒΡ‚ΠΎΡ†ΠΈΡ‚ΠΎΠΊΠΈΠ½ΠΈΠ² Π½Π° рост прСдставитСлСй Π½ΠΎΡ€ΠΌΠ°Π»ΡŒΠ½ΠΎΠΉ ΠΌΠΈΠΊΡ€ΠΎΡ„Π»ΠΎΡ€Ρ‹ толстой кишки ΠΈ подавляли Π½Ρ‹ΠΉ эффСкт Π² ΠΎΡ‚Π½ΠΎΡˆΠ΅Π½ΠΈΠΈ условно-ΠΏΠ°Ρ‚ΠΎΠ³Π΅Π½Π½Ρ‹Ρ… ΠΌΠΈΠΊΡ€ΠΎΠΎΡ€Π³Π°Π½ΠΈΠ·ΠΌΠΎΠ². ВыяснСно, Ρ‡Ρ‚ΠΎ Π°ΡƒΡ‚ΠΎΡ†ΠΈΡ‚ΠΎΠΊΠΈΠ½Ρ‹ Π½Π΅ ΠΏΡ€ΠΎΡΠ²Π»ΡΡŽΡ‚ сущСствСнного влияния Π½Π° ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ Π°Π½Ρ‚ΠΈΠ±ΠΈΠΎΡ‚ΠΈΠΊΠΎΡ‡ΡƒΠ²ΡΡ‚Π²ΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎΡΡ‚ΠΈ ΠΌΠΈΠΊΡ€ΠΎΠΎΡ€Π³Π°Π½ΠΈΠ·ΠΌΠΎΠ².The autocytokinins’ influence on the change of biological characteristics of the microorganisms secured from patients with non-specific ulcerous colitis has been studied. It has been found that autocytokinin samples have a stimulating influence on the growth of large intestine’s normal microflora and inhibiting effect to opportunistic pathogenic microorganisms. Autocytokinins are proved to have no significant influence on the antibiotic sensitivity of microorganisms
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