We report the first observation of coherent precession of magnetization in superfluid 3He A-like phase (CP-A) in aerogel. The coherent precession in bulk 3He A-phase is unstable due to the positive ...feedback of spin supercurrent to the gradient of phase of precession. It was predicted that the homogeneous precession will be stable if the orbital momentum of the 3He A-phase can be oriented along the magnetic field. We have succeeded to prepare this configuration by emerging 3He in uniaxially deformed anisotropic aerogel. The dissipation rate of coherent precession states in aerogel is much larger than that in bulk 3He B-phase. We propose a mechanism of this dissipation.
As part of an international validation project to establish a test protocol for the ‘Enhanced OECD Test Guideline no. 407’, a 28-day repeated dose study of flutamide was performed (1) to examine ...which of the current and/or additional parameters can detect endocrine effects of test chemicals most reliably and sensitively, (2) to investigate whether it is actually feasible to routinely include all additional parameters into the testing routine, and (3) to assess intra-laboratory variability by performing two identical studies (experiments A and B) in parallel using groups of five animals each per dose and sex. Groups of five male and five female CD(SD)IGS rats were treated by oral gavage with 0, 1, 10 and 100
mg
flutamide/kg body weight for at least 28 days. The dose level considered to be around the MTD (100
mg/kg) exerted the expected antiandrogenic effects on androgen related tissues: significant decrease of the weights of androgen dependent organs and the sperm count and increase in histopathological lesions. At the middle dose (10
mg/kg), significant decrease of prostate weight (ventral and dorso-lateral parts combined) was observed and it was suggested that weight measurement of androgen dependent organs provides the most reliable and sensitive endpoint with this protocol. As for the feasibility, because of many items in this protocol, selection should be based on the sensitivity. From our data, addition of weight measurement of androgen dependent organs to the items of the existing OECD 407 guideline might allow accurate screening for endocrine disruptors. At the dose level considered to be around the MTD, the findings achieving statistical significance in one experiment with five animals/dose/sex could be reproduced in the second experiment, and evaluation with the small groups was consistent with findings using the combined groups of 10 animals/dose/sex. The results demonstrate that the protocol can reliably detect antiandrogenic effects of flutamide.
The spatial distribution and seasonal variation in the concentrations in Lake Biwa of pesticides used in paddy fields were studied. Lake Biwa is the largest lake in Japan and is a recognized water ...resource for 14 million people in the Kinki district. Samples were collected nine times from April to December 2001 at ten sites within the lake and at the mouths of six influent rivers. Weekly sampling was also carried out at a single site on an effluent river. Among the 20 pesticides analyzed, the detection frequencies in surface water were almost 100% for simetryn, bromobutide, and isoprothiolane; around 75% for molinate and pyroquilon; around 30% for three herbicides and one fungicide; and almost zero for the remaining substances. The maximum concentrations of pesticides detected frequently in the lake were in the range 0.1–0.4 µg l⁻¹. The occurrence of a few pesticides below the thermocline may be explained by thermal stratification and vertical circulation. Although the thermocline suppressed vertical diffusion in spring and summer during pesticide application periods, a few pesticides remaining at the surface of the lake in winter were transported to the hypolimnion by vertical circulation and remained there even after the reestablishment of the thermocline. The half-lives of pesticides in the lake were estimated to be more than a year for simetryn, half a year for bromobutide, 1.5 months for molinate, and 1 month for dimepiperate. The main cause of elimination for molinate and dimepiperate was estimated to be degradation, that for simetryn was outflow, and for bromobutide both degradation and outflow were significant.
Superfluid super(3He A-like and B-like phases in 98% aerogel have been studied under rotation up to 2pi rad/s by using cw-NMR and Homogeneous Pressing Domain (HPD) NMR at 29 mT and 3.0 MPa. We ...studied the dissipation of the HPD in aerogel and found that the HPD-mode was destroyed by onset of the thermal runaway for sufficient large sample under a large field gradient. From the field dependence of the onset of thermal runaway, we estimated dissipation of the HPD in aerogel and compared with that of the bulk B-phase. When angular velocity of rotation goes beyond Omega) sub(c), vortices are introduced and pinned. We estimate roughly the excess dissipation due to vortices and compare it with that of vortices in bulk B-phase.
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