Major-element trend for shergottite melts and their source materials

The major-element compositions of shergottite melts, plotted against their mg [Mg/(Mg+Fe)] atomic ratios, form a narrow trend, which is designated the shergottite melt trend". Although the mg ratios range from 0.7 to 0.2, the silica contents of the trend are nearly constant from 47 to 53wt%, indicating that the shergottite melts are basaltic, never andesitic nor komatiitic. The trend is enriched in FeO with the range from 15 to 22wt%, and poor in Al_2O_3 with the range from 4 to 14wt%. The melts for nakhlites are poorer in SiO_2 and Al_2O_3 and richer in FeO than the shergottite melt trend. Although the melts for chassignite are similar to the shergottite melt trend, the melts for chassignite and nakhlites are more enriched in K_2O contents than the shergottites melts, indicating that they have a different origin from the latter. The bulk major-element compositions of terrestrial basalts, lunar basalts, and eucrites are compared to the shergottite melt trend. The terrestrial basalts and komatiites are poorer in FeO and richer in Al_2O_3, CaO, and Na_2O than the shergottite melt trend. The lunar low-Ti mare basalts and eucrites have rather similar compositions to the shergottite trend. However, their alkali and P_2O_5 contents are low in comparison to the shergottite trend, reflecting their planetary compositions. A plausible source material for olivine-phyric shergottites was estimated, and it may be a plagioclase peridotite with an mg ratio of 0.81 depleted in alkalis, CaO and Al_2O_3 contents. The partial melting to produce the shergottite trend may have taken place at low pressures, whereas the nakhlites and chassignite may have been produced under moderate (1-30kb) pressure conditions. The chassignite may have fractionated under a low-pressure condition to produce a large amount of cumulus olivine, whereas the nakhlites have not

Frontiers of torenia research: innovative ornamental traits and study of ecological interaction networks through genetic engineering

Advances in research in the past few years on the ornamental plant torenia (Torenia spps.) have made it notable as a model plant on the frontier of genetic engineering aimed at studying ornamental characteristics and pest control in horticultural ecosystems. The remarkable advantage of torenia over other ornamental plant species is the availability of an easy and high-efficiency transformation system for it. Unfortunately, most of the current torenia research is still not very widespread, because this species has not become prominent as an alternative to other successful model plants such as Arabidopsis, snapdragon and petunia. However, nowadays, a more global view using not only a few selected models but also several additional species are required for creating innovative ornamental traits and studying horticultural ecosystems. We therefore introduce and discuss recent research on torenia, the family Scrophulariaceae, for secondary metabolite bioengineering, in which global insights into horticulture, agriculture and ecology have been advanced. Floral traits, in torenia particularly floral color, have been extensively studied by manipulating the flavonoid biosynthetic pathways in flower organs. Plant aroma, including volatile terpenoids, has also been genetically modulated in order to understand the complicated nature of multi-trophic interactions that affect the behavior of predators and pollinators in the ecosystem. Torenia would accordingly be of great use for investigating both the variation in ornamental plants and the infochemical-mediated interactions with arthropods

Petrology of a new basaltic shergottite: Dhofar 378

Dhofar 378 is a new basaltic shergottite, consisting mainly of pyroxenes, plagioclase glass, phosphates, titanomagnetite, and mesostasis. It is one of the most ferroan shergottites and resembles the Los Angeles shergottite. Pyroxenes show remarkable chemical zoning from 0.4 of Mg/(Mg+Fe) to less than 0.1, and their REE patterns are depleted in light REE whereas the REE pattern of the bulk Dhofar 378 is flat. All plagioclase grains in the original lithology completely melted by an intense impact shock, and the plagioclase melts crystallized fibrous plagioclase to form the rims surrounding the plagioclase melts. Then, the melts quenched as plagioclase glass to form the cores. The shock stage of Dhofar 378 is higher than that of the Los Angeles shergottite. The degree of impact shock for Dhofar 378 may be about 55-75GPa and is the highest among all known martian meteorites

センジョウ カンソク データ ニ モトヅク ナンキョク リュツォ・ホルムワン テイチャクヒョウ ノ カキ ニオケル ヒョウアツ オヨビ セキセツシン ブンプ トクセイ ニツイテ

南極観測船「しらせ」船上で取得された海氷観測結果をもとに,リュツォ・ホルム湾定着氷の夏季における氷厚及び積雪深分布について考察した.ビデオ観測結果から求めた各年の全氷厚(氷厚+積雪深)確率密度分布は薄氷型と厚氷型に分けられることがわかった.また大陸沿岸から約km圏内では全氷厚及び積雪深は沿岸に向かって漸減する傾向を示した.これは北東方向の卓越風による積雪輸送によると考えられる.電磁誘導法によって観測された全氷厚分布には不連続的な変化が認められた.NOAAAVHRR画像と比較した結果,不連続の位置は定着氷流出後の再結氷域における一年氷と,未流出の厚い多年氷との境界に一致することがわかった.定着氷の流出範囲は年によって大きく変動する.流出位置が沖側に後退すると厚い多年氷域の割合が多くなり厚氷型になり,沿岸に近づくと積雪影響も相まって厚い多年氷域が縮小または消滅し,薄氷型になるというメカニズムが明らかになった.Sea ice observations have been conducted onboard the Antarctic Research Vessel Shirase" since . The authors summarize these data to investigate spatial and inter-annual variability of sea ice thickness and snow depth of the summer land-fast ice in Lutzow-Holmbukta. Probability density functions of annual total thickness (ice thickness+snow depth) derived from video observations are categorized into two types, i.e. a thin-ice and a thick-ice type. The total thickness distributions observed by the electro-magnetic inductive method have a clear discontinuity, which reects the past break-up of the land-fast ice. Thin rst-year ice develops oshore of this location, while multi-year ice mostly develops onshore. Ice thickness and snow depth gradually decrease toward the coast within about km oshore, probably due to snow drift driven by the strong northeasterly wind. It is concluded that the past breakup of the land-fast ice as well as snow depth have dominant inuence on the spatial distribution of ice thickness in Lutzow-Holmbukta. The extent of break-up varies signicantly year by year. The smaller extent enhances the development of thick multi-year ice, while the larger extent, coupled with the inuence of snow drift, enhances reduction or extinction of thick multi-year ice

Missing western half of the Pacific Plate: Geochemical nature of the Izanagi-Pacific Ridge interaction with a stationary boundary between the Indian and Pacific mantles

The source mantle of the basaltic ocean crust on the western half of the Pacific Plate was examined using Pb–Nd–Hf isotopes. The results showed that the subducted Izanagi–Pacific Ridge (IPR) formed from both Pacific (180–∼80 Ma) and Indian (∼80–70 Ma) mantles. The western Pacific Plate becomes younger westward and is thought to have formed from the IPR. The ridge was subducted along the Kurile–Japan–Nankai–Ryukyu (KJNR) Trench at 60–55 Ma and leading edge of the Pacific Plate is currently stagnated in the mantle transition zone. Conversely, the entire eastern half of the Pacific Plate, formed from isotopically distinct Pacific mantle along the East Pacific Rise and the Juan de Fuca Ridge, largely remains on the seafloor. The subducted IPR is inaccessible; therefore, questions regarding which mantle might be responsible for the formation of the western half of the Pacific Plate remain controversial. Knowing the source of the IPR basalts provides insight into the Indian–Pacific mantle boundary before the Cenozoic. Isotopic compositions of the basalts from borehole cores (165–130 Ma) in the western Pacific show that the surface oceanic crust is of Pacific mantle origin. However, the accreted ocean floor basalts (∼80–70 Ma) in the accretionary prism along the KJNR Trench have Indian mantle signatures. This indicates the younger western Pacific Plate of IPR origin formed partly from Indian mantle and that the Indian–Pacific mantle boundary has been stationary in the western Pacific at least since the Cretaceous

A high-resolution linkage map for comparative genome analysis and QTL fine mapping in Asian seabass, Lates calcarifer

10.1186/1471-2164-12-174BMC Genomics12-BGME

Characteristics of sea ice thickness and snow depth distributions of the land-fast ice during summer in Lutzow-Holmbukta, Antarctica,revealed from ship-based observations

Sea ice observations have been conducted onboard the Antarctic Research Vessel Shirase" since . The authors summarize these data to investigate spatial and inter-annual variability of sea ice thickness and snow depth of the summer land-fast ice in Lutzow-Holmbukta. Probability density functions of annual total thickness (ice thickness+snow depth) derived from video observations are categorized into two types, i.e. a thin-ice and a thick-ice type. The total thickness distributions observed by the electro-magnetic inductive method have a clear discontinuity, which reects the past break-up of the land-fast ice. Thin rst-year ice develops oshore of this location, while multi-year ice mostly develops onshore. Ice thickness and snow depth gradually decrease toward the coast within about km oshore, probably due to snow drift driven by the strong northeasterly wind. It is concluded that the past breakup of the land-fast ice as well as snow depth have dominant inuence on the spatial distribution of ice thickness in Lutzow-Holmbukta. The extent of break-up varies signicantly year by year. The smaller extent enhances the development of thick multi-year ice, while the larger extent, coupled with the inuence of snow drift, enhances reduction or extinction of thick multi-year ice