Experimental allergic encephalomyelitis in agammaglobulinemic chickens

White Leghorn chickens were subjected to bursectomy and total body irradiation at hatching, thus rendering them agammaglobulinemic. At 4 weeks of age, these chickens and control chickens received lyophilized bovine spinal cord emulsified with complete Freund's adjuvant. Agammaglobulinemic chickens developed the lesions of allergic encephalomyelitis with the same frequency and intensity as the controls. Our findings support the contention that antibodies are not necessary for the development of experimental allergic encephalomyelitis.     

Cosmogenic and primordial radionuclides in lunar samples by nondestructive gamma-ray spectrometry

The (7)Be, (22)Na, (26)Al, (44)Ti, (46)SC, (48)V (51)Cr, (54)Mn, (56)Co, (57)Co, (57)CO, (40)K, (238)U, and (232)Th were measured in lunar fines and portions of three rocks. Major production of cosmogenic radionuclides is due to solar protons, thus their concentrations are far different than those in meteorites. Surface exposures of the rocks and fines are long compared with the 0.74 million year half-life of (26)Al. Lunar fines show substantially higher concentrations of low energy reaction products. The ratios of thorium to uranium are extremely constant at 3.8, which indicates very little geochemical differentiation and are in good agreement with a common nucleosynthesis for lunar and earth materials.     

Cosmic ray-produced radionuclides as tracers of atmospheric precipitation processes

Through recent developments in instrumental analysis it is now possible to measure with good precision the rainwater concentrations of five short-lived radionuclides which are produced by cosmic ray spallation of atmospheric argon. These measurements provide a method for studying the in-cloud nucleation times and aerosol scavenging efficiencies, and promise to provide information onshort-term processes which occur in rain and snow formation.     

Diverse plant and animal genetic records from Holocene and Pleistocene sediments

Genetic analyses of permafrost and temperate sediments reveal that plant and animal DNA may be preserved for long periods, even in the absence of obvious macrofossils. In Siberia, five permafrost cores ranging from 400,000 to 10,000 years old contained at least 19 different plant taxa, including the oldest authenticated ancient DNA sequences known, and megafaunal sequences including mammoth, bison, and horse. The genetic data record a number of dramatic changes in the taxonomic diversity and composition of Beringian vegetation and fauna. Temperate cave sediments in New Zealand also yielded DNA sequences of extinct biota, including two species of ratite moa, and 29 plant taxa characteristic of the prehuman environment. Therefore, many sedimentary deposits may contain unique, and widespread, genetic records of paleoenvironments.     

Uplifted marine terraces along the alpine fault, new zealand

Three types of evidence indicate that marine terraces are widespread in the Southern Alps of New Zealand. (i) Remnants of shore platforms occur as distinct levels of notched ridge crests and flat summits; degraded sea cliffs are common. (ii) Scattered quartz beach pebbles occur on 16 of 18 levels of exhumed shore platforms in the Fox- Franz Josef type area to altitudes as high as 1700 meters. (iii) Altitudinal spacings of New Zealand terrace flights allow correlation with 18 dated global marine terraces at New Guinea, which were formed during glacio-eustatic highstands of sea level within the last 336 x 10(3) years. Inferred uplift rates at Fox-Franz Josef increased from 3.2 to 7.8 meters per 10(3) years since about 135 x 10(3) to 140 x 10(3) years ago, presumably because of increased convergence between the Pacific and Australian plates.     

Cellular transforming genes

Cellular genes potentially capable of inducing oncogenic transformation have been identified by homology to the transforming genes of retroviruses and by the biological activity of cellular DNA's in transfection assays. DNA's of various tumors induce transformation with high efficiencies, indicating that oncogenesis can involve dominant genetic alterations resulting in activation of cellular transforming genes. The identification and characterization of cellular transforming genes and their possible involvement in naturally occurring cancers, is discussed.     

Multimodal signals: enhancement and constraint of song motor patterns by visual display

Many birds perform visual signals during their learned songs, but little is known about the interrelationship between visual and vocal displays. We show here that male brown-headed cowbirds (Molothrus ater) synchronize the most elaborate wing movements of their display with atypically long silent periods in their song, potentially avoiding adverse biomechanical effects on sound production. Furthermore, expiratory effort for song is significantly reduced when cowbirds perform their wing display. These results show a close integration between vocal and visual displays and suggest that constraints and synergistic interactions between the motor patterns of multimodal signals influence the evolution of birdsong.     

THE GOLDEN HAMSTER (CRICETUS AURATUS) AS A TEST ANIMAL FOR THE DIAGNOSIS OF LEPTOSPIROSIS

There is evidence that the golden hamster (Cricetus auratus) is the animal of choice for the isolation of leptospirae, especially of the Leptospira canicola type since young guinea pigs and mice are resistant to infection and rats are entirely refractory. Both the classical strain, L. icterohaemorrhagiae and L. canicola on isolation have been found to produce a fatal infection in hamsters. The present report deals with the isolation of L. canicola in two instances by the injection intraperitoneally into hamsters of urine obtained from dogs ill with suspected leptospirosis. Each of the dogs was apparently the source of infection for a human case of Canicola leptospirosis. The classical strain L. icterohaemorrhagiae was isolated from the dog for the first time in the United States. In this instance the organism was isolated by injecting both whole blood and urine from the patient intraperitoneally into young hamsters. The injection into hamsters of suitable material from patients infected with L. canicola and L. icterohaemorrhagiae is followed by a fatal leptospirosis in the test animal.