Pancreatic β-Cell Death, Regeneration and Insulin Secretion: Roles of Poly(ADP-Ribose) Polymerase and Cyclic ADP-Ribose

In the early 1980s, we proposed a unifying model for β-cell damage (The OKAMOTO model), in which poly(ADP-ribose) synthetase/ polymerase (PARP) activation plays an essential role in the consumption of NAD+, which leads to energy depletion and necrotic cell death. In 1984, we demonstrated that the administration of PARP inhibitors to 90% depancreatized rats induces islet regeneration. From the regenerating islet-derived cDNA library we isolated Reg (Regenerating Gene) and demonstrated that Reg protein induces βcell replication via the Reg receptor and ameliorates experimental diabetes. More recently, we showed that the combined addition of IL-6 and dexamethasone induces the Reg gene expression in β-cells and that PARP inhibitors enhance the expression. In 1993, we found that cyclic ADP-ribose (cADPR), a product synthesized from NAD+, is a second messenger for intracellular Ca+ mobilization for insulin secretion by glucose, and proposed a novel mechanism of insulin secretion, the CD38-cADPR signal system

Fundamental Analytics of Mirror Photogrammetry

Mirror photogrammetry is discussed fundamentally in this paper. First, the relationship between an object and the satellite picture (a photograph taken of the virtual object) is investigated and an interesting property of the satellite picture is clarified that parameters defining the mirror surface in the object space coordinate system are absorbed only by the exterior orientation elements of the reflected satellite picture (the mirror reflection of the satellite picture). Based on this fact, the orientation problem of overlapped mirror photographs is solved for various configurations of cameras and mirrors. In addition, the orientation calculation using mirror parameters as the orientation unknowns is described by introducing the law of reflection in terms of direction cosines. The non-central projective parameters such as those defining lens distortion, effect of lack of film flatness, and mirror undulation are considered separately

Different Considerations in Mirror Photogrammetry

The self calibration of a non-metric camera without object space information requires an assumption that the interior orientation is unchanged between more than two photographs taken of the same three-dimensional object. However, this criterion may not be valid for many non-metric cameras. On the other hand, it is not very difficult to manufacture high-quality front-surfaced mirrors with practically no undulation. Also, by placing such a plane mirror close to an object so that a non-metric camera can record not only the object directly but also its mirror reflection, the above assumption can be satisfied rigorously between the normal and satellite pictures taken on the same negative. In addition, constraints are generated among the exterior orientation parameters of the stereopair of mirror photographs. Based on both these findings and the potential theory of overlapped photographs (Okamoto [1986]), this paper discusses the self calibration problem of non-metric cameras employing plane mirrors in detail. Further, the constraints regarding the exterior orientation of overlapped mirror photographs prove to be replaced by coplanarity equations and object space information redundantly used. Finally, corrections techniques for mirror distortions are presented

General Orientation Problem of Photographs with Planar Objects

The orientation problem of photographs taken of planar objects can be treated as a special case for that of a three-dimensional object space. Based on this concept, this paper derived an orientation theory for a two-dimensional object space where the geometry of a picture can, in general, be determined by eight independent central projective parameters. First, the relationship between an object plane and its picture was explored in different ways. Then, the characteristics of the orientation problem were clarified for a stereopair of photographs and for multiple pictures overlapped. The orientation calculation was formulated algebraically with the DLT approach. The orientation methods proposed here are quite general and applicable to the rectification of non-metric photographs with planar objects. In particular, using distances as object space controls, we can form a model congruent to the object by means of a single photograph having non-linear distortions. Also, elements describing the non-linear errors can be provided from the potential of a stereopair of photographs. Furthermore, by employing three pictures overlapped, a united model similar to the object can be constructed without object space information, when we can assume that the interior orientation is unchanged in the three photographs

Mechanical Properties of Simply Supported Prestressed Concrete Beams under Repeated Over-Loadings

Results of an experimental investigation on the mechanical behavior of simply supported prestressed concrete beams under repeated over-loading are described. This load was characterized by higher maximum load near the failure and the relatively slow loading velocity counting at most 100 cycles to the failure. Differences between the dynamic properties of grouted beams and of non-grouted beams under these loadings are also discussed. Test results give many interesting suggestions for the theoretical approach on the load-deformation relation of prestressed concrete baems subject to repeated over-loadings. It must be noticed that the deformation-dependent change of dissipated energy for the prestressed concrete beam is quite different from that for steel structure and of U-shaped curves

Physical Relation of Source I to IRc2 in the Orion KL Region

We present mid-infrared narrow-band images of the Orion BN/KL region, and N-band low-resolution spectra of IRc2 and the nearby radio source "I." The distributions of the silicate absorption strength and the color temperature have been revealed with a sub-arcsecond resolution. The detailed structure of the 7.8 micron/12.4 micron color temperature distribution was resolved in the vicinity of IRc2. A mid-infrared counterpart to source I has been detected as a large color temperature peak. The color temperature distribution shows an increasing gradient from IRc2 toward source I, and no dominant temperature peak is seen at IRc2. The spectral energy distribution of IRc2 could be fitted by a two-temperature component model, and the "warmer component" of the infrared emission from IRc2 could be reproduced by scattering of radiation from source I. IRc2 itself is not self-luminous, but is illuminated and heated by an embedded luminous young stellar object located at source I.Comment: 20 pages, 11 figures. Minor corrections had been done in the ver.2. Accepted for publication in PAS

シリョウ:ヘイセイ 23ネンド コウカイ コウザ ホウシャノウ ト ホウシャセイ ブッシツ ノ カクサン ノ ショウカイ

平成23年度公開講座で説明した放射性物性の拡散についての解説記事は比較的に好評であったので、ここにその内容を紹介する。すでに、その一部は、畠中伸敏監修で日本規格協会より出版された「予防と未然防止」の著書の中でも紹介されているが、その際に紙面の都合で割愛された測定データの解釈などに関する考察も含めて、ほぼ全文をここに紹介するThe author has explained about radioactivity and dispersion of radioactive material in a 2011 open lecture of the Tokyo University of Information Sciences. As this lecture could get a favorable reception, brief summary of the lecture will be reproduced here. A part of the contents was already appeared in the boo

Mindin/F-spondin Family: Novel ECM Proteins Expressed in the Zebrafish Embryonic Axis

AbstractF-spondin is a secreted protein expressed at high levels by the floor plate cells. The C-terminal half of the protein contains six thrombospondin type 1 repeats, while the N-terminal half exhibited virtually no similarity to any other protein until recently, when aDrosophilagene termedM-spondinwas cloned; its product was found to share two conserved domains with the N-terminal half of F-spondin. We report the molecular cloning of four zebrafish genes encoding secreted proteins with these conserved domains. Two are zebrafish homologs ofF-spondin,while the other two, termedmindin1andmindin2,encode mutually related novel proteins, which are more related to theDrosophilaM-spondin than to F-spondin. During embryonic development, all four genes are expressed in the floor plate cells. In addition to the floor plate,mindin1is expressed in the hypochord cells, whilemindin2is expressed in the sclerotome cells. When ectopically expressed, Mindin proteins selectively accumulate in the basal lamina, suggesting that Mindins are extracellular matrix (ECM) proteins with high affinity to the basal lamina. We also report the spatial distribution of one of the F-spondin proteins, F-spondin2. F-spondin2 is localized to the thread-like structure in the central canal of the spinal cord, which is likely to correspond to Reissner's fiber known to be present in the vertebrate phylum. In summary, our study has defined a novel gene family of ECM molecules in the vertebrate, all of which may potentially be involved in development of the midline structure