Pathology and epidemiology of canine distemper in raccoon dogs (Nyctereutes procyonoides).

From September to December 1991, a large number of free-ranging raccoon dogs (Nyctereutes procyonoides) died from a highly contagious disease in the vicinity of Tokyo. Eighteen seriously ill or dead animals were submitted for necropsy. The pathological findings resembled those in a masked palm civet (Paguma larvata) found infected with canine distemper virus (CDV) in the same area in late August 1991. The most striking features were pneumonia and gastroenteritis. Microscopical lesions consisted of cytoplasmic and intranuclear eosinophilic inclusion bodies in various organs and tissues, bronchiolointerstitial pneumonia, non-suppurative demyelinating encephalitis, lymphocytic depletion in various lymphoid tissues and catarrhal or necrotizing gastroenteritis. CDV-specific antigens, demonstrated immunohistochemically in the epithelial tissues, central nervous system and lymphoid tissues, corresponded with the presence of the eosinophilic inclusion bodies in sections of the same lesions stained with haematoxylin and eosin. Ultrastructurally, both cytoplasmic and intranuclear inclusion bodies were observed to be composed of aggregates of viral nucleocapsids. The study provided clear evidence that CDV was the cause of the disease. It is possible that the masked palm civet introduced the infection into the raccoon dog population.

Effect of physical fitness and training on physiological responses to hypogravity.

The studies on the orthostatic tolerance during the hypodynamics exposure seem to be significant in connection with the selection, training and health maintenance of astronauts. Using male human subjects of various physical fitness levels, fluctuations of their physical fitness through 2 weeks of vigorous athletic training were measured in many parameters. For some of the subjects, the effects of 6 hr thermal neutral water immersion exposure in head out supine position on the physical fitness parameters and orthostatic tolerability were compared before training with after training. The results obtained were as follows: (1) Before training, orthostatic tolerability before hypodynamics exposure increased, following the physical fitness levels; the value after the hypodynamics exposure decreased in all the cases, but no differences were observed between the physical fitness levels. (2) As a result of training an increase of the physical fitness capacity was observed. The increase of orthostatic tolerability before hypodynamics exposure was noticed except for athletes. (3) Before hypodynamics exposure the urinary excretion of noradrenaline on non-athlete subjects increased as the physicsl fitness level increased. The values were decreased by physical training, the more so the better the physical fitness. After hypodynamics exposure the same relation was observed. But for athletes the values remain more stable and the decrease by hypodynamics exposure was not so distinctive. Such decreased reaction to hypodynamic conditions seems to reveal the neuro hormonal mechanism for the detrimental adaptation of athletes to hypodynamics. These results suggest that stable athletes do not always have low orthostatic tolerability, but do not respond well to hypodynamic conditions, at least from the orthostatic point of view. The mechanism seems related to sympathetic nerve activity.

Effect of laser power and specimen temperature on atom probe analyses of magnesium alloys.

The influence of laser power, wave length, and specimen temperature on laser assisted atom probe analyses for Mg alloys was investigated. Higher laser power and lower specimen temperature led to improved mass and spatial resolutions. Background noise and mass resolutions were degraded with lower laser power and higher specimen temperature. By adjusting the conditions for laser assisted atom probe analyses, atom probe results with atomic layer resolutions were obtained from all the Mg alloys so far investigated. Laser assisted atom probe investigations revealed detailed chemical information on Guinier-Preston zones in Mg alloys.

Broadening the applications of the atom probe technique by ultraviolet femtosecond laser.

Laser assisted field evaporation using ultraviolet (UV) wavelength gives rise to better mass resolution and signal-to-noise ratio in atom probe mass spectra of metals, semiconductors and insulators compared to infrared and green lasers. Combined with the site specific specimen preparation techniques using the lift-out and annular Ga ion milling in a focused ion beam machine, a wide variety of materials including insulating oxides can be quantitatively analyzed by the three-dimensional atom probe using UV laser assisted field evaporation. After discussing laser irradiation conditions for optimized atom probe analyses, recent atom probe tomography results on oxides, semiconductor devices and grain boundaries of sintered magnets are presented.