コウソク ストレス ノ ハンノウセイ ニオケル ラット ノ ケイトウサ

ストレスは様々な疾患の発症に関与することが知られている.また個体がストレスを受けたときに起こる最も顕著な生体反応の一つが視床下部・下垂体・副腎軸の活性化である.視床下部・下垂体・副腎軸におけるラットの系統差を明らかにすることはストレスに対する生体反応,例えば免疫抑制 行動変化および高血圧などの研究を行う上でも意義がある.本特集ではSD(日本チャールズ・リバー : Crj), F344(Crj), Wistar(Crj), Wistar-Imamichi(WI,動物繁殖研究所 : Iar),およびLE(Iar)のそれぞれ成熟雄ラットを用いて,視床下部・下垂体・副腎軸の機能評価を行った我々の研究データを示すと共に,ストレス反応におけるラットの系統差について紹介する

Isospin character of low-lying states in 56Fe.

Low-lying states in {sup 56}Fe, up to an excitation energy of about 4 MeV, have been investigated by means of inelastic proton and deuteron scattering experiments at {ital E}{sub {ital p}}=65 and 400 MeV and at {ital E}{sub {ital d}}=56 MeV, respectively. Measured cross sections and analyzing powers have been compared with coupled-channels calculations using collective form factors; calculations in both the Schr{umlt o}dinger and Dirac formalisms have been carried out for the proton data. For each probe, the matrix elements have been deduced for transitions from the ground state and from the 2{sub 1}{sup +} state to six quadrupole (2{sup +}) states to one octupole (3{sub 1}{sup {minus}}) and two hexadecapole (4{sub 1}{sup +} and 4{sub 2}{sup +}) states. The obtained matrix elements and the previous values from {gamma} decay or electron inelastic scattering have been used to evaluate the isospin character of the transitions. To discuss the quadrupole mixed-symmetry states in {sup 56}Fe, the deduced neutron ({ital M}{sub {ital n}}) and proton ({ital M}{sub {ital p}}) components of the matrix elements, or equivalently the isoscalar ({ital M}{sub {ital s}}) and isovector ({ital M}{sub {ital v}}) parts, have been compared with theoretical calculations based on the neutron-proton interacting bosonmore » model and on the shell model evaluated in a full {ital f}-{ital p} configuration space. {copyright} {ital 1996 The American Physical Society.}« les

Study of stress in dairy cattle during student practical training on a farm

We investigated changes in cortisol (COR) concentration, which is well known as an index of stress in the serum of dairy cattle. The COR concentrations in serum obtained from dairy cattle were collected during practical training of first-year students on a farm attached to the Nippon Veterinary and Life Science University. Mean COR concentration in serum determined after practical training was significantly higher (P < 0.001) than that in serum collected before training. Discriminant analysis was used to classify the relation between COR concentration of serum collected before and after practical training. In conclusion, the data was bipartite according to the percentage of rise (rise rate) of COR concentration. Although the percentage of the rise was more than 300% in the high-rise-rate group, there was a significant negative correlation (P < 0.05) between age and COR concertation. It was thought that the high-rise-rate group has a chance to decrease stress after more experience. In contrast, the low-rise-rate group included 3 cattle indicating high COR concentration before and after practical training. Those 3 cattle were thought to be stressed easily. It is suggested that there was individual difference to stress