Saitama Prefectural Police

任意の地すべり土塊中の抑止杭の最大抑止力とそれが発揮される瞬間の杭頭変位量の大きさについて, 地すべり土塊の形状や杭の施工位置, 地盤の物性などに基づいて系統的に調べることは, 実務上の意義が極めて大きい。これは地すべり対策事業のコストダウンと安全性向上に直結する。本研究では, 設計で利用されうる簡易な地すべりモデルを対象にして, 三次元弾塑性FEMに基づくパラメトリック・スタディが実施される。各解析ケースにおいては, 地すべり抑止杭の最大抑止力とその時の杭頭変位量が予測され, これらの値と各種条件との間の関係について考察がなされる。また, 現行設計法に基づく解との比較から, その留意点についてもあわせて検討がなされる。最後に, 三次元弾塑性FEMによる解析に要する時間コストを節約するため, FEMの結果を学習させたニューラル・ネットワークが構築され, これが実務において利用される方向性が示唆される。ニューラル・ネットワークに基づく最大抑止力の予測は極めて容易であり, 計算プログラムが非常に軽いため, ネットワーク・コンピューティングを前提とした設計システムの開発の可能性が示される。

The right 4th costal cartilages of 110 Japanese cadavers (55 males and 55 females) were radiographically examined to elucidate the sex differences in the pattern of calcification. Calcification was observed in the cartilages of both sexes aged over 20 years. Twenty out of 98 subjects showed no calcification despite being over 20 years old; so calcification at this site did not occur with aging in all adults, but was seen in approximately 80%. Calcification showed 3 patterns, which were marginal, central, and granular calcification pattern. The marginal pattern was observed in 39 subjects (33 males and 6 females), the central pattern in 15 (all female) and the granular pattern in 20 (1 male and 19 females). Detailed investigation of the internal structure at the distal ends of the ribs and the shape of the costochondral junction revealed better estimates of age compared with the degree of calcification alone, which showed wide individual variation. Radiographic examination of the costal cartilages is useful and conveniet for estimating the sex and age, not only of fragmentary and partial remains, but also of skeletons or badly decomposed bodies. Moreover, it may be effective as a screening test for identification after large-scale disasters.

N-Cyanomethylmethamphetamine (CMMA), N-formylmethamphetamine (FMA) and methamphetamine (MA) were given intraperitoneally to mouse and rat in doses of 3 mg/kg. The major metabolites of CMMA, FMA and MA in plasma were determined at short intervals after administration by GC-MS to obtain the area under the concentration-time curve (AUC). Regarding the plasma concentration of FMA after CMMA administration, a definite species difference was observed between mouse and rat. In rats given CMMA, FMA was the major component, followed by MA, amphetamine (AP), CMMA and N-formylamphetamine (FAP). In mice given CMMA, MA was a major component, followed by AP, FMA, CMMA and FAP. However, it was demonstrated that MA is also non-enzymatically produced from CMMA in plasma. Following FMA administration to rats, FMA was the major component in the plasma, showing the largest AUC value of the four metabolites, FMA, FAP, MA and AP. Following FMA administration to mice, MA showed the largest AUC value, followed by FMA, FAP and AP which were present at low levels even 5 min after injection and were scarcely detectable at 60 min. These results suggest two main mechanisms involved in the metabolism of the N-cyanomethyl group, one of which is the formation of MA by elimination of cyanoformaldehyde from N-alpha-hydroxylated CMMA and the other which is the formation of FMA by elimination of hydrogen cyanide from N-alpha-hydroxylated CMMA. The formation of FMA from CMMA was the predominant pathway in rats but not in mice.