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Invited for the cover of this issue is the group of Yoshiaki Nishibayashi at The University of Tokyo, Japan. The cover image shows the synthesis of novel “metalloviologens” bearing PNP pincer ligands based on N-methyl-4,4′-bipyridinium. These complexes are stable toward two steps of single electron transfer, where p-quinoid-type complexes play a key role.

We successfully completed the development of a GaN based Tunable laser for Tapestry holographic data storage through collaborative research with InPhase Technologies in 2010. After the collaborative research, with the aim to achieve further advance development for commercial storage use, we have continued to improve the laser characteristics, especially coherence property and high optical output power are significant issues for holographic data storage. Longitudinal single mode lasing is one of most important property in hologram recording; therefore we addressed to optimize laser diode structure for external cavity laser. In parallel to that, we have reviewed not only a Laser diode structure but also laser drive processing, and have successfully developed a function. In the case of performing high visibility hologram recording, prior to exposing to medium, both the laser driving current and the wavelength are slightly adjusted to achieve single mode lasing. We call this function “Mode Stabilizer”. Mode Stabilizer can automatically execute the adjustments in combination with an internal mode sensor for visibility sensing. This function is advantageous in that erroneous page-recording can be avoided. Moreover, we achieved high optical output power of 100 mW increased from conventional 45 mW, by optimizing the device structure of GaN Laser diode. With this high optical output power, acceleration of recording bit rate becomes possible.

By the middle of 1960's, the International Oil Trusts had discovered and operated many giant oil fields in the Middle East region almost exclusively. They begun to relinquish the part of their concession based on their understanding on the shortage of unexplored big structures in this area and the growing power of oil producing countries. The several Japanese oil firms started their exploration and production activities on these relinquished areas. Under such a circumstances Japanese explorationists and engineers had carried out and realized substantial contribution.The drastic development of oil producing countries in Arabian Gulf area were realised in 1970's. They promoted the nationalization of oil resources by their newly established national oil companies in each countries, and emphasized the importance of secondary recovery scheme for the purpose of increasing the recovery percentage on the developed oil fields.The newly participated Japanese oil firms in this decade conducted their operation in good manner with their sophisticated techniques and established the mutual trust relationship between the oil producing countries.Some alternative energy resources replacing of petroleum could be utilized in some time in the far future. However, the maintenance of oil resources is essential for the mankind till such time. Particulary in our country, much more promotion of oil exploration is indispensable for the survival and prosperity in the 21st century, because of the most of the Japanese industries, business frameworks and personal life have been established on the foundation mainly composed of enormous consumption of oil resources.

The Arabian-Zagros sedimentary basin, renowned as a huge oil pool-bearing field, is composed of a large quantity of carbonate strata associated with a considerably limited argillaceous strata.During the past quarter century, various studies on the mechanisms of hydrocarbon generation and accumulation in the Persian Gulf area have been carried out. As the result, the following two different opinions concerning the oil generation and migration have been raised: A) catagenetic origin and long distance migration, and B) diagenetic origin and short distance migration. However, at present, the opinions and points of these two groups are independent each other and there are no sufficient discussions between them.The basic conception of the opinion (A) is that a possible source sediment should be placed to a deep burial depth through a sufficient geological time to generate petroleum via so-called “Kerogen”. This is a conception derived mostly from the studies on the argillaceous rocks. On the other hand, if we pay special attention to the organic and inorganic characteristics of carbonate rocks, particularly its efficient capability of hydrocarbon generation and the very likely possibility of generating hydrocarbons which directly generated from the organic matter of carbonate's own without via “Kerogen stage” as pointed out by TAGUCHI (1989), it is possible to accept the conception of (B) rather than (A).Based on the such previous studies and the geological evidences obtained from the actual exploration and exploitation in the studied area, conceivable characteristics for the oil production in this area should be summarized as follows. Namely, (1)extremely high volume of carbonate sediments in comparison with argillaceous sediments, (2)a difficulty of large scale vertical migration due to extensive distribution of dense evaporite (anhydrite, in particular) and (3)the existence of many depletion type oil fields which may have been formed by deterioration of reservoir in the down flank area during the course of the structural growth by high saturation of formation water, etc.Consequently, it is inferred that most of oil in the southern part of the Persian Gulf area might have originated from organic matter of carbonate rocks and accumulated in the favorable structures at the relatively early diagenetic stage through short primary migration pass.In future, more detailed geochemical studies on the carbonate rocks (especially pure carbonates) will be required to solve the diversities among those opinions mentioned above.(This abstract covers the contents of this Part 1 and Part 2 which is to follow. The subtitle of Part 2 is-“Noticeable points on the carbonate source rocks and the specific characters of the accumulation mechanism”-).

GD3 is an intracellular mediator of apoptotic signaling. Although GD3 is known to directly act on mitochondria, the dynamic responses of individual mitochondria to GD3 remain to be elucidated. In the current study, the membrane potential of single mitochondria is observed in the presence of GD3 or its analogues. Here, we report that (1) GD3 specifically induces gradual depolarizations of the inner membrane by a mechanism that differs from the permeability transition, and (2) the GD3-induced depolarizations are suppressed by cyclosporin A. These results suggest that GD3 depolarizes mitochondria by a mechanism distinct from but relevant to the permeability transition.

We realized room-temperature lasing of blue and green GaN-based vertical-cavity surface-emitting lasers (VCSELs), for the first time, by current injection. The blue GaN-based VCSEL had a threshold current of 1.5 mA and a threshold voltage of 3.3 V under continuous-wave operation. Its maximum output power was 0.70 mW and its laser emission wavelength was 451 nm. The green GaN-based VCSEL had a threshold current of 22 mA and a threshold voltage of 6.3 V under pulsed current operation. Its maximum output power was estimated to be over 0.80 mW and the laser emission wavelength was 503 nm.

We compared the lasing characteristics of GaN-based vertical-cavity surface-emitting lasers (VCSELs) fabricated using a GaN substrate with those fabricated using a sapphire substrate. The original substrates are removed from the devices after the devices have been bonded to Si substrates. Consequently, with the exception of the cavity length, the two kinds of fabricated VCSELs have almost the same structures. The VCSELs fabricated using a GaN substrate have a higher maximum output power (0.62 mW) and longer lifetimes than those fabricated using a sapphire substrate. Even for the VCSELs fabricated with a GaN substrate, 10-min operation causes their threshold current to increase.

We report the demonstration of CW lasing at room temperature in a GaN-based vertical-cavity surface-emitting laser (VCSEL) by current injection. The active region of the VCSEL consisted of a two-pair InGaN/GaN quantum well active layer. The optical cavity consisted of a 7-λ-thick GaN semiconductor layer and an indium tin oxide layer for p-contact embedded between two SiO2/Nb2O5 dielectric distributed Bragg reflectors. The VCSEL was mounted on a Si substrate by wafer bonding and the sapphire substrate was removed by laser lift-off. Under CW operation for an 8-µm aperture device, the threshold current was 7.0 mA and the emission wavelength was approximately 414 nm.

According to Dr. Ishiwada and present writers (1962), the Uvigerina akitaensis assemblage zone which makes practically the top of the Umegase formation disappears in the west side area of Chiba City and is replaced by sediments characterized by the cold shallow-water fauna. In the Funabashi FR-18, the top of Umegase formation lies at 665 m below the surface and the shallow-water fauna appears at the Otadai and upper formations. From these evidences, the Kazusa group changes lithofacies and biofacies from southeast to northwest. Judging from lithofacies, biofacies and sandstone percentage of the Kazusa group, two types, that is, primary and secondary, are recognized in its mode of sedimentation of sand. The secondary transported sands stand in some relation to gas potentiality because of their equigranular texture.

Microbiofacies of the Kazusa group in the western part of the Chiba gas field are extremely different from those of the eastern part. The Umegase and the underlying formations indicate mostly stable bathyal environment in the east side area of Chiba city. But in the west side area of Chiba city, the fossil foraminiferal faunas are of a shallow water habitat. Concerning these problems, the writers examined many samples collected from the gas wells. From the foraminiferal sequence of an exploratoly well P-1 and the biofacies maps (FIG. 2-FIG. 7) of the area, they have come to the following conclusion.The sedimentary environment in the Kiwada stage was bathyal one in the both side areas, except in Chiba district, where the f oraminiferal fauna shows a relatively shallow and marginal facies. It may be considered that some barrier was present in this district in the stages of lower Kazusa formations. The sedimentation behaviors in the west side area of this barrier were fairly different from those in the east side area, and these different characters have caused the different mode of natural gas accumulation. And also the presence of some relief of basement rocks in the district is more possible than it was imagined before.

The Miyata formation occurs in the southern part of the Miura peninsula, Kanagawa prefecture, Japan., Since previous publications on this formation have described chiefly its Foraminifera and Mollusca, the principal purpose of this paper is to describe the environmental conditions under which the formation was deposited as determined from a study of foraminiferal assemblages., The Miyata formation consists of conglomerate and cross-bedded sandstone containing shells, which are overlain in succession by sandstone, an alternation of sandstone, and siltstone, and fossiliferous sandstone., The Miyata formation overlies the Hayama and Hayashi formations unconformably and the Kwanto volcanic ash overlies the Miyata formation unconformably., The Miyata formation is about 20 meters thick at the cliff at Okine (locs., 1, 2)., It is bounded on the north and south by vertical faults., Forminifera were collected from 19 different localities in the Miyata formation, but in all cases from the same stratigraphic horizon., These collections were compared with Recent Foraminifera from the tidal zone and inter-tidal region in the vicinity of the Miura peninsula to aid in the determination of the paleo-environment of the Miyata foraminiferal assemblages., The following conclusions were reached : 1) The foraminiferal assemblages of the Miyata formation comprise species flourishing in shallow water., The east and central parts of the Miyata formation are deeper than the western part in depositional facies, as inferred from the bathymetrical distribution of the Foraminifera., 2) The distribution of the Foraminifera within the Miyata formation shows an intimate relationship with the litho-facies, particularly with the grain size distribution of the rocks., 3) The temperature of the sea water at the time of deposition of the formation, as inferred from the Foraminifera, was somewhat lower than or nearly the same as the present sea water adjacent to the peninsula., 4) The fossil Foraminifera comprise an assemblage which lived near the shore of the open-sea.