580 research outputs found
Magmatic overpressures, volatile exsolution and potential explosivity of fissure eruptions inferred via dike aspect ratios
Buoyant magmas abundant in exsolved volatiles (bubbles) drive the rapid upward-propagation of feeder dikes from magma chambers. The consequence of a feeder dike reaching the surface can result in an explosive volcanic eruption depending, partly, on the retention of volatiles. Therefore, timely detection of the vesicularity and overpressure of the magma during feeder dike ascent is critical for the prediction of the explosivity of any future eruption. In this study, we evaluated the explosivity of eruptions based on field investigations of the erupted products and the overpressure of magma in the conduit based on the dimensions of exposed feeder dikes. We found a positive correlation between the explosivity of eruptions and the magma overpressure generated in the conduit during recent fissure eruptions of Miyakejima volcano. Because the buoyancy of low-density magma produces positive overpressure at the dikeβs top, feeder dikes with highly-vesiculated magmas possess high amounts of overpressure. An enlargement of the opening width of a feeder dike by magmatic overpressure results in a higher flux of vesiculated magma, which causes vigorous explosive activity. Our results suggest the possibility of forecasting the explosivity of an impending eruption if the width (or opening) of an ascending feeder dike is monitored in real-time through measurements of ground deformation and seismicity induced by the dike
Magnesium substitution in calcium and strontium fluoro-phospho-aluminosilicate glasses by multinuclear 19F, 31P, 27Al, and 29Si MAS-NMR spectroscopy
Department of Trade and Industry, UK, under the project number of TP/5/REG/6/I/H0669
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Are both agricultural intensification and farmland abandonment threats to biodiversity? A test with bird communities in paddy-dominated landscapes
Land-use changes, including agricultural intensification and farmland abandonment, influence biodiversity in agricultural landscapes. However, few studies have focused on how the two major land-use changes affect different types of species at landscape scales. This study examined the relationships between the richness and abundance of five bird groups (agricultural wetland species, agricultural land species, grassland species, edge species, and woodland species) as well as the total species richness and abundance, and intensification or abandonment in 28 square, 100-ha grid cells in paddy-dominated landscapes in the Tone River basin of central Japan. Rice-field intensification and abandonment were not completely segregated spatially: intensification occurred in both plain and hilly areas surrounded by forests, while abandonment tended to occur in hilly areas. The effects of intensification and abandonment differed among species groups and between seasons. The richness or abundance of agricultural wetland species in summer were negatively associated with both intensification and abandonment. While the abundance of agricultural land species in winter and grassland species in both seasons were positively associated with intensification and abandonment, respectively. The total species richness and abundance did not show clear association with intensification and abandonment due to a variety of responses of the five bird groups. Based on prefectural Red Data Books, agricultural wetland species, followed by grassland species, were more threatened than other three groups in both summer and winter. This study found that (1) the diversity of habitats (including consolidated and abandoned farmlands) provides buffer areas for the different bird groups on different times of the year and (2) agricultural wetland species that use flooded rice fields in summer, such as egrets and shorebirds, are particularly threatened by both intensification and abandonment.We thank Yoshinori Tokuoka, Susumu Yamada, Eun-Young Kim, and Shori Yamamoto for providing land-use data. We also appreciate two anonymous reviewers for their constructive comments and suggestions. This study was conducted as part of the research project βDeveloping management techniques for agricultural and aquatic ecosystems in river basins in pursuit of coexistence with nature,β funded by the Agriculture, Forestry and Fisheries Research Council of Japan. N.K. and T.O. were also financially supported by JSPS (Japan Society for the Promotion of Science) KAKENHI Grant Numbers 25830154 and 24710038, respectively. T.A. was supported by the European Commissionβs Marie Curie International Incoming Fellowship Programme (PIIFGA-2011-303221).This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.agee.2015.08.01
Effects of ethyl-esterization, chain-lengths, unsaturation degrees, and hyperthermia on carcinostatic effect of omega-hydroxylated fatty acids
Aim: To evaluate promotive effect of hyperthermia on the carcinostatic activity of synthesized omega-hydroxy fatty acids (wHFAs) and their ethylesters agaist Ehrlich ascites tumor (EAT) cells. Methods: EAT cells were cultured with either wHFAs or their ethylester derivatives in a water bath at either 37 Β°C or 42 Β°C for 30 min, followed by incubation in a CO2 incubator for 20 or 72 h. Mitochondrial dehydrogenase-based WST-1 assay and trypan blue dye exclusion assay were then conducted after incubation. Morphological changes were observed by scanning electron microscopy (SEM). Results: Omega-HFA having a saturated 16-carbon straight-chain (wH16:0) was the most carcinostatic (at 37 Β°C β viability level: 60.0%; at 42 Β°C β 49.6% (WST-1)) among saturated and unsaturated wHFAs with 12, 15 or 16 carbon atoms, when administrated to EAT cells at 100 Β΅M for 20 h. Carcinostatic activity was markedly enhanced by ethyl-esterization of saturated fatty acids, such as wH16:0 (at 37 Β°C β 42.3%; at 42 Β°C β 11.2% , ibid) and wH15:0 (at 37 Β°C β 74.6%; at 42 Β°C β 25.3% , ibid), and their unsaturated counterparts were extremely effective only in combination with hyperthermia. Prolongation of the incubation period to 72 h at the same concentration increased appreciably their carcinostatic effect (wH16:0 ethylesther: 1.3%; wH15:0 ethylesther: 8.0%). These values were also supported by dye exclusion assay. The carcinostatic activity enhanced more markedly by hyperthermia (1.2%; 2.1%, ibid). SEM shows that wH16:0 ethylester-exposed EAT cells underwent extensive injury, such as deformation of cell structure or disappearance of microvilli. Conclusions: wH16:0 ethylester possesses high carcinostatic activity in vitro in combination with hyperthermia and may be utilized as potent anticancer therapeutic agent.Π¦Π΅Π»Ρ: ΠΏΡΠΎΠ°Π½Π°Π»ΠΈΠ·ΠΈΡΠΎΠ²Π°ΡΡ ΡΡΠΈΠ»ΠΈΠ²Π°ΡΡΠΈΠΉ ΡΡΡΠ΅ΠΊΡ Π³ΠΈΠΏΠ΅ΡΡΠ΅ΡΠΌΠΈΠΈ Π½Π° ΠΊΠ°Π½ΡΠ΅ΡΠΎΡΡΠ°ΡΠΈΡΠ΅ΡΠΊΡΡ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΡ ΡΠΈΠ½ΡΠ΅Π·ΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
ΠΎΠΌΠ΅Π³Π°Π³ΠΈΠ΄ΡΠΎΠΊΡΠΈΠ»ΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
ΠΆΠΈΡΠ½ΡΡ
ΠΊΠΈΡΠ»ΠΎΡ (HFAs) ΠΈ ΠΈΡ
ΡΡΠΈΠ»ΠΎΠ²ΡΡ
ΡΡΠΈΡΠΎΠ² ΠΏΠΎ ΠΎΡΠ½ΠΎΠ΅Π½ΠΈΡ ΠΊ ΠΊΠ»Π΅ΡΠΊΠ°ΠΌ Π°ΡΡΠΈΡΠ½ΠΎΠΉ ΠΎΠΏΡΡ
ΠΎΠ»ΠΈ ΡΠ»ΠΈΡ
Π°
(EAT). ΠΠ΅ΡΠΎΠ΄Ρ: ΠΊΠ»Π΅ΡΠΊΠΈ EAT ΠΈΠ½ΠΊΡΠ±ΠΈΡΠΎΠ²Π°Π»ΠΈ Ρ HFAs ΠΈΠ»ΠΈ ΠΈΡ
ΡΡΠΈΠ»ΡΡΠΈΡΠ½ΡΠΌΠΈ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΡΠΌΠΈ Π½Π° Π²ΠΎΠ΄Π½ΠΎΠΉ Π°Π½Π΅ ΠΏΡΠΈ 37 Β° ΠΈΠ»ΠΈ
42 Β° Π² ΡΠ΅ΡΠ΅Π½ΠΈΠ΅ 30 ΠΌΠΈΠ½ Ρ Π΄Π°Π»ΡΠ½Π΅ΠΉΠΈΠΌ ΠΊΡΠ»ΡΡΠΈΠ²ΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ Π² 2
ΠΈΠ½ΠΊΡΠ±Π°ΡΠΎΡΠ΅ Π½Π° ΠΏΡΠΎΡΡΠΆΠ΅Π½ΠΈΠΈ 20 ΠΈΠ»ΠΈ 72 Ρ, ΠΏΠΎΡΠ»Π΅ ΡΠ΅Π³ΠΎ Π°Π½Π°Π»ΠΈΠ·ΠΈΡΠΎΠ²Π°Π»ΠΈ
ΠΆΠΈΠ·Π½Π΅ΡΠΏΠΎΡΠΎΠ±Π½ΠΎΡΡΡ ΠΊΠ»Π΅ΡΠΎΠΊ ΠΌΠ΅ΡΠΎΠ΄Π°ΠΌΠΈ Π°Π½Π°Π»ΠΈΠ·Π° WST-1, ΠΎΡΠ½ΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ Π½Π° Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ ΠΌΠΈΡΠΎΡ
ΠΎΠ½Π΄ΡΠΈΠ°Π»ΡΠ½ΡΡ
Π΄Π΅Π³ΠΈΠ΄ΡΠΎΠ³Π΅Π½Π°Π·, ΠΈ ΠΏΠΎ
Π²ΠΊΠ»ΡΡΠ΅Π½ΠΈΡ ΡΡΠΈΠΏΠ°Π½ΠΎΠ²ΠΎΠ³ΠΎ ΡΠΈΠ½Π΅Π³ΠΎ. ΠΠΎΡΡΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡ ΠΊΠ»Π΅ΡΠΎΠΊ ΠΎΠΏΡΠ΅Π΄Π΅Π»ΡΠ»ΠΈ Ρ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ ΡΠΊΠ°Π½ΠΈΡΡΡΡΠ΅ΠΉ ΡΠ»Π΅ΠΊΡΡΠΎΠ½Π½ΠΎΠΉ
ΠΌΠΈΠΊΡΠΎΡΠΊΠΎΠΏΠΈΠΈ. Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ: ΠΏΡΠΈ ΠΊΡΠ»ΡΡΠΈΠ²Π°ΡΠΈΠΈ ΠΊΠ»Π΅ΡΠΎΠΊ EAT Π² ΠΏΡΠΈΡΡΡΡΡΠ²ΠΈΠΈ 100 M ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΠΉ Π² ΡΠ΅ΡΠ΅Π½ΠΈΠ΅ 20 Ρ ΠΎΠΌΠ΅Π³Π°-HFA
Ρ Π½Π°ΡΡΡΠ΅Π½Π½ΠΎΠΉ 16-ΡΠ³Π»Π΅ΡΠΎΠ΄Π½ΠΎΠΉ ΠΏΡΡΠΌΠΎΠΉ ΡΠ΅ΠΏΡΡ (H16:0) ΠΏΡΠΎΡΠ²Π»ΡΠ»ΠΈ Π½Π°ΠΈΠ±ΠΎΠ»Π΅Π΅ Π²ΡΡΠ°ΠΆΠ΅Π½Π½ΡΠΉ ΠΊΠ°Π½ΡΠ΅ΡΠΎΡΡΠ°ΡΠΈΡΠ΅ΡΠΊΠΈΠΉ ΡΡΡΠ΅ΠΊΡ (ΠΏΡΠΈ
37 Β° ΡΡΠΎΠ²Π΅Π½Ρ ΠΆΠΈΠ·Π½Π΅ΡΠΏΠΎΡΠΎΠ½ΠΎΡΡΠΈ ΡΠΎΡΡΠ°Π²ΠΈΠ» 60,0%; ΠΏΡΠΈ 42 Β° 49,6% (WST-1)) ΠΏΠΎ ΡΡΠ°Π²Π½Π΅Π½ΠΈΡ Ρ ΡΠ°ΠΊΠΎΠ²ΡΠΌ Π½Π°ΡΡΡΠ΅Π½Π½ΡΡ
ΠΈ Π½Π΅Π½Π°ΡΡΡΠ΅Π½Π½ΡΡ
HFAs, ΡΠΎΠ΄Π΅ΡΠΆΠ°ΡΠΈΡ
12, 15 ΠΈΠ»ΠΈ 16 Π°ΡΠΎΠΌΠΎΠ² ΡΠ³Π»Π΅ΡΠΎΠ΄Π°. Π°Π½ΡΠ΅ΡΠΎΡΡΠ°ΡΠΈΡΠ΅ΡΠΊΠ°Ρ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΡ Π·Π½Π°ΡΠΈΡΠ΅Π»ΡΠ½ΠΎ Π²ΠΎΠ·ΡΠ°ΡΡΠ°Π»Π° ΠΏΡΠΈ
ΡΡΠΈΠ»ΡΡΠ΅ΡΠΈΡΠΈΠΊΠ°ΡΠΈΠΈ Π½Π°ΡΡΡΠ΅Π½Π½ΡΡ
ΠΆΠΈΡΠ½ΡΡ
ΠΊΠΈΡΠ»ΠΎΡ, ΡΠ°ΠΊΠΈΡ
ΠΊΠ°ΠΊ H16:0 (ΠΏΡΠΈ 37 Β° 42,3%; ΠΏΡΠΈ 42 Β° 11,2%, ibid) ΠΈ H15:0
(ΠΏΡΠΈ 37 Β° 74,6%; ΠΏΡΠΈ 42 Β° 25,3% , ibid), Π² ΡΠΎ Π²ΡΠ΅ΠΌΡ ΠΊΠ°ΠΊ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΡΠ΅ Π½Π΅Π½Π°ΡΡΡΠ΅Π½Π½ΡΡ
ΠΊΠΈΡΠ»ΠΎΡ Π±ΡΠ»ΠΈ Π²ΡΡΠΎΠΊΠΎΡΡΡΠ΅ΠΊΡΠΈΠ²Π½Ρ
ΡΠΎΠ»ΡΠΊΠΎ Π² ΠΊΠΎΠΌΠ±ΠΈΠ½Π°ΡΠΈΠΈ Ρ Π³ΠΈΠΏΠ΅ΡΡΠ΅ΡΠΌΠΈΠ΅ΠΉ. Π£Π²Π΅Π»ΠΈΡΠ΅Π½ΠΈΠ΅ ΠΏΠ΅ΡΠΈΠΎΠ΄Π° ΠΈΠ½ΠΊΡΠ±Π°ΡΠΈΠΈ ΠΊΠ»Π΅ΡΠΎΠΊ Π΄ΠΎ 72 Ρ ΠΏΡΠΈ ΡΠΎΠΉ ΠΆΠ΅ ΠΊΠΎΠ½ΡΠ΅Π½ΡΡΠ°ΡΠΈΠΈ Π²Π΅ΡΠ΅ΡΡΠ²
ΠΏΡΠΈΠ²ΠΎΠ΄ΠΈΠ»ΠΎ ΠΊ Π·Π½Π°ΡΠΈΡΠ΅Π»ΡΠ½ΠΎΠΌΡ ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΡ ΠΈΡ
ΠΊΠ°Π½ΡΠ΅ΡΠΎΡΡΠ°ΡΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π΄Π΅ΠΉΡΡΠ²ΠΈΡ (ΡΡΠΈΠ»ΠΎΠ²ΡΠΉ ΡΡΠΈΡ H16:0 1,3%; ΡΡΠΈΠ»ΠΎΠ²ΡΠΉ ΡΡΠΈΡ
H15:0 ethylesther 8,0%), ΠΏΠΎΠ΄ΡΠ²Π΅ΡΠΆΠ΄Π΅Π½Π½ΠΎΠ³ΠΎ Π΄Π°Π½Π½ΡΠΌΠΈ ΠΎΠΊΡΠ°ΡΠΊΠΈ ΡΡΠΈΠΏΠ°Π½ΠΎΠ²ΡΠΌ ΡΠΈΠ½ΠΈΠΌ. ΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ Π³ΠΈΠΏΠ΅ΡΡΠ΅ΡΠΌΠΈΠΈ ΡΠ°ΠΊΠΆΠ΅ ΡΡΠΈΠ»ΠΈΠ²Π°Π»ΠΎ
ΠΊΠ°Π½ΡΠ΅ΡΠΎΡΡΠ°ΡΠΈΡΠ΅ΡΠΊΠΎΠ΅ Π΄Π΅ΠΉΡΡΠ²ΠΈΠ΅ ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΠΉ (1,2%; 2,1%, ibid). Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ SEM ΠΏΠΎΠΊΠ°Π·Π°Π»ΠΈ, ΡΡΠΎ
ΠΊΠ»Π΅ΡΠΊΠΈ EAT, ΠΈΠ½ΠΊΡΠ±ΠΈΡΠΎΠ²Π°Π½Π½ΡΠ΅ Ρ ΡΡΠΈΠ»ΠΎΠ²ΡΠΌ ΡΡΠΈΡΠΎΠΌ H16:0, ΡΠ°Π·ΡΡΠ°ΡΡΡΡ Ρ Π½Π°ΡΡΡΠ΅Π½ΠΈΠ΅ΠΌ ΠΊΠ»Π΅ΡΠΎΡΠ½ΠΎΠΉ ΡΡΡΡΠΊΡΡΡΡ ΠΈ ΠΈΡΡΠ΅Π·Π½ΠΎΠ²Π΅Π½ΠΈΠ΅ΠΌ
ΠΌΠΈΠΊΡΠΎΠ²ΠΎΠ»ΠΎΠΊΠΎΠ½. ΠΡΠ²ΠΎΠ΄Ρ: Π² ΠΊΠΎΠΌΠ±ΠΈΠ½Π°ΡΠΈΠΈ Ρ Π³ΠΈΠΏΠ΅ΡΡΠ΅ΡΠΌΠΈΠ΅ΠΉ ΡΡΠΈΠ»ΠΎΠ²ΡΠΉ ΡΡΠΈΡ H16:0 ΠΏΡΠΎ Π΅Ρ Π²ΡΡΠΎΠΊΡΡ ΠΊΠ°Π½ΡΠ΅ΡΠΎΡΡΠ°ΡΠΈΡΠ΅ΡΠΊΡΡ
Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΡ in vitro, ΡΡΠΎ Π³ΠΎΠ²ΠΎΡΠΈΡ ΠΎ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΡΡΠΈ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΡ ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΡ Π² ΡΠ΅ΡΠ°ΠΏΠΈΠΈ ΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΡΡ
Π·Π°Π±ΠΎΠ»Π΅Π²Π°Π½ΠΈΠΉ
Spatially explicit approach to estimation of total population abundance in field surveys.
Population abundance is fundamental in ecology and conservation biology, and provides essential information for predicting population dynamics and implementing conservation actions. While a range of approaches have been proposed to estimate population abundance based on existing data, data deficiency is ubiquitous. When information is deficient, a population estimation will rely on labor intensive field surveys. Typically, time is one of the critical constraints in conservation, and management decisions must often be made quickly under a data deficient situation. Hence, it is important to acquire a theoretical justification for survey methods to meet a required estimation precision. There is no such theory available in a spatially explicit context, while spatial considerations are critical to any field survey. Here, we develop a spatially explicit theory for population estimation that allows us to examine the estimation precision under different survey designs and individual distribution patterns (e.g. random/clustered sampling and individual distribution). We demonstrate that clustered sampling decreases the estimation precision when individuals form clusters, while sampling designs do not affect the estimation accuracy when individuals are distributed randomly. Regardless of individual distribution, the estimation precision becomes higher with increasing total population abundance and the sampled fraction. These insights provide theoretical bases for efficient field survey designs in information deficiency situations
Measurement of the cosmic-ray antiproton spectrum at solar minimum with a long-duration balloon flight over Antarctica
The energy spectrum of cosmic-ray antiprotons from 0.17 to 3.5 GeV has been
measured using 7886 antiprotons detected by BESS-Polar II during a
long-duration flight over Antarctica near solar minimum in December 2007 and
January 2008. This shows good consistency with secondary antiproton
calculations. Cosmologically primary antiprotons have been investigated by
comparing measured and calculated antiproton spectra. BESS-Polar II data show
no evidence of primary antiprotons from evaporation of primordial black holes.Comment: 4 pages, 4 figures, submitted to Physical Review Letter
Measurement of Cosmic-Ray Antiproton Spectrum at Solar Minimum with a Long-Duration Balloon Flight in Antarctica
The energy spectrum of cosmic-ray antiprotons (p(raised bar)'s) collected by the BESS-Polar II instrument during a long-duration flight over Antarctica in the solar minimum period of December 2007 through January 2008. The p(raised bar) spectrum measured by BESS-Polar II shows good consistency with secondary p(raised bar) calculations. Cosmologically primary p(raised bar)'s have been searched for by comparing the observed and calculated p(raised bar) spectra. The BESSPolar II result shows no evidence of primary p(raised bar)'s originating from the evaporation of PBH
Aggregatibacter actinomycetemcomitans Omp29 Is Associated with Bacterial Entry to Gingival Epithelial Cells by F-Actin Rearrangement
The onset and progressive pathogenesis of periodontal disease is thought to be initiated by the entry of Aggregatibacter actinomycetemcomitans (Aa) into periodontal tissue, especially gingival epithelium. Nonetheless, the mechanism underlying such bacterial entry remains to be clarified. Therefore, this study aimed to investigate the possible role of Aa outer membrane protein 29 kD (Omp29), a homologue of E. coli OmpA, in promoting bacterial entry into gingival epithelial cells. To accomplish this, Omp29 expression vector was incorporated in an OmpA-deficient mutant of E. coli. Omp29+/OmpAβ E. coli demonstrated 22-fold higher entry into human gingival epithelial line cells (OBA9) than Omp29β/OmpAβ E. coli. While the entry of Aa and Omp29+/OmpAβ E. coli into OBA9 cells were inhibited by anti-Omp29 antibody, their adherence to OBA9 cells was not inhibited. Stimulation of OBA9 cells with purified Omp29 increased the phosphorylation of focal adhesion kinase (FAK), a pivotal cell-signaling molecule that can up-regulate actin rearrangement. Furthermore, Omp29 increased the formation of F-actin in OBA9 cells. The internalization of Omp29-coated beads and the entry of Aa into OBA9 were partially inhibited by treatment with PI3-kinase inhibitor (Wortmannin) and Rho GTPases inhibitor (EDIN), both known to convey FAK-signaling to actin-rearrangement. These results suggest that Omp29 is associated with the entry of Aa into gingival epithelial cells by up-regulating F-actin rearrangement via the FAK signaling pathway
Precise measurements of hydrogen and helium isotopes with BESS-Polar II
A precise knowledge of cosmic-ray hydrogen and helium isotopes provides important information to better understand Galactic cosmic-ray propagation. Deuteron and helium 3 species are mainly secondary particles created by the spallation of primary proton and helium 4 particles during their propagation in the Galaxy. Secondary-to-primary ratios thus bring direct information on the average amount of material traversed by cosmic rays in the interstellar medium. The Balloon-borne Experiment with Superconducting Spectrometer BESS-Polar II flew over Antarctica for 24.5 days from December 2007 through January 2008, during the 23rd solar cycle minimum. The instrument is made of complementary particle detectors which allow to precisely measure the charge, velocity and rigidity of incident cosmic rays. It can accurately separate and precisely measure cosmic-ray hydrogen and helium isotopes between 0.2 and 1.5 GeV/nucleon. These data, which are the most precise to date, will be reported and their implications will be discussed
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