A pathologic study on ocular disorders in calves in southern Kyushu, Japan

Of 822 calves, ranging in age between one day and six months necropsied between 1996 and 1998 at Miyazaki University, histological examination showed that 25 (3.0%) had ocular lesions. These ocular lesions consisted of suppurative inflammation (13 cases), cataract (seven cases), and retinal atrophy (five cases). Inflammatory changes were classified as suppurative keratitis (one case), keratitis and uveitis (ten cases), and uveitis and retinitis (two cases). Cataract was subclassified into three categories; cortical (three cases), nuclear (one case), and mature (three cases). These lesions were characterized by degenerative changes in the lens fibers and the appearance of eosinophilic globules known as Morganian globules. In the most severely affected case, there was capsular rupture of the lens, resulting in severe infiltration by eosinophils and histiocytes of the whole anterior chamber. Almost all the calves with retinal atrophy had been suffering from severe hydranencephaly and three had significantly raised levels of neutralization antibodies for the Akabane and/or Aino viruses. This study indicates that congenital arbovirus infections may predispose calves to ocular diseases, especially retinal atrophy.     

An epizootiological survey of necropsy cases (1993-1997) at University of the Philippines

An epizootiological survey of necropsied cases (1993-1997) at University of the Philippines was performed. A total of 368 cases included 238 avian and 111 porcine cases. Amongst avian cases, the major cause of death was infectious diseases in 212 (89%) cases including 97 (41%) bacterial, 36 (15%) viral, and 21(9%) parasitic diseases. The majority of the avian bacterial diseases presented as septicemia (73 cases) and the viral diseases as Newcastle disease (17 cases). In porcine cases, the major cause of death was also infectious diseases, in 100 (90%) cases including 52 bacterial and 29 viral diseases. Porcine bacterial diseases were classified into 36 septicemia, 4 hemophillosis and 4 colibacillosis. Amongst the porcine viral diseases, most cases were diagnosed as Hog cholera (22 cases).     

Amyloid angiopathy with cerebral hemorrhage and senile plaque in aged dogs

Amyloid angiopathy with cerebral hemorrhage and senile plaques was found in the brain of aged dogs. In all 9 cases examined, 13 to 19 years old, 6 males and 3 females, amyloid deposits were observed mostly in the wall of cerebral arterioles and capillaries showed hyaline degeneration. The accumulation of amyloid fibrils measuring about 10 nm in diameter was seen in the cerebral vessel wall by electron microscopy. The cerebral hemorrhage was observed in 6 of 9 dogs and 2 of them showed massive hemorrhage. The hemorrhagic foci were sometimes closely contact with the vessels involved in amyloid angiopathy. In addition, senile plaques being classified into 2 types were found in the cerebral cortex of 3 dogs. The first type was characterized by the accumulation of degenerative neurites and often contained granular argyrophilic material. The second type had a well-defined amyloid core with neuritic halo. Amyloid deposits were also found in or around intestinal vessel walls of 3 dogs. The amyloid deposited in the cerebral vessels, senile plaques and intestinal vessels showed characteristic green birefringence under the polarized light even after potassium permanganate treatment.     

The yohkoh mission for high-energy solar physics

The Japanese Yohkoh satellite is now in orbit observing the sun with a set of x-ray imagers and x-ray and gamma-ray spectrometers. The data from this successful mission provide new information on solar flares and the sun's corona. This paper discusses the Yohkoh observations and presents a sample of the first scientific results from the mission.     

Imaging quasiparticle interference in Bi2Sr2CaCu2O8+delta

Scanning tunneling spectroscopy of the high-Tc superconductor Bi2Sr2CaCu2O8+delta reveals weak, incommensurate, spatial modulations in the tunneling conductance. Images of these energy-dependent modulations are Fourier analyzed to yield the dispersion of their wavevectors. Comparison of the dispersions with photoemission spectroscopy data indicates that quasiparticle interference, due to elastic scattering between characteristic regions of momentum-space, provides a consistent explanation for the conductance modulations, without appeal to another order parameter. These results refocus attention on quasiparticle scattering processes as potential explanations for other incommensurate phenomena in the cuprates. The momentum-resolved tunneling spectroscopy demonstrated here also provides a new technique with which to study quasiparticles in correlated materials.     

Magnetohydrodynamic production of relativistic jets

A number of astronomical systems have been discovered that generate collimated flows of plasma with velocities close to the speed of light. In all cases, the central object is probably a neutron star or black hole and is either accreting material from other stars or is in the initial violent stages of formation. Supercomputer simulations of the production of relativistic jets have been based on a magnetohydrodynamic model, in which differential rotation in the system creates a magnetic coil that simultaneously expels and pinches some of the infalling material. The model may explain the basic features of observed jets, including their speed and amount of collimation, and some of the details in the behavior and statistics of different jet-producing sources.