SONOGRAPHIC EVALUATION OF EXPERIMENTAL BILE DUCT LIGATION IN THE DOG

The common bile duct was surgically ligated in five normal adult dogs. Ultrasonographic examinations of the gallbladder and biliary system were performed after duct ligation at intervals of 24 hours. The sequence of biliary system dilation was from the common duct to the peripheral intrahepatic ducts. Common duct enlargement was evident in 24–48 hours, while peripheral biliary duct dilation was recognized by five to seven days after obstruction. When compared with hepatic and portal veins, dilated biliary ducts were more tortuous and had irregular branching patterns. Gross pathologic changes were correlated with ultrasonographic findings at seven, 14, 15, 18 and 21 days after obstruction.     

Limited host range in the idiobiont parasitoid Phymastichus coffea,a prospective biological control agent of the coffee pest Hypothenemus hampei in Hawaii

Phymastichus coffea LaSalle (Hymenoptera:Eulophidae) is an adult endoparasitoid of the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera:Curculionidae:Scolytinae), which has been introduced in many coffee producing countries as a biological control agent. To determine the effectiveness of P. coffea against H. hampei and environmental safety for release in Hawaii, we investigated the host selection and parasitism response of adult females to 43 different species of Coleoptera, including 23 Scolytinae (six Hypothenemus species and 17 others), and four additional Curculionidae. Non-target testing included Hawaiian endemic, exotic and beneficial coleopteran species. Using a no-choice laboratory bioassay, we demonstrated that P. coffea was only able to parasitize the target host H. hampei and four other adventive species of Hypothenemus: H. obscurus, H. seriatus, H. birmanus and H. crudiae. Hypothenemus hampei had the highest parasitism rate and shortest parasitoid development time of the five parasitized Hypothenemus spp. Parasitism and parasitoid emergence decreased with decreasing phylogenetic relatedness of the Hypothenemus spp. to H. hampei, and the most distantly related species, H. eruditus, was not parasitized. These results suggest that the risk of harmful non-target impacts is low because there are no native species of Hypothenemus in Hawaii, and P. coffea could be safely introduced for classical biological control of H. hampei in Hawaii.

     

Early results from the infrared astronomical satellite

For 10 months the Infrared Astronomical Satellite (IRAS) provided astronomers with what might be termed their first view of the infrared sky on a clear, dark night. Without IRAS, atmospheric absorption and the thermal emission from both the atmosphere and Earthbound telescopes make the task of the infrared astronomer comparable to what an optical astronomer would face if required to work only on cloudy afternoons. IRAS observations are serving astronomers in the same manner as the photographic plates of the Palomar Observatory Sky Survey; just as the optical survey has been used by all astronomers for over three decades, as a source of quantitative information about the sky and as a "roadmap" for future observations, the results of IRAS will be studied for years to come. IRAS has demonstrated the power of infrared astronomy from space. Already, from a brief look at a miniscule fraction of the data available, we have learned much about the solar system, about nearby stars, about the Galaxy as a whole and about distant extragalactic systems. Comets are much dustier than previously thought. Solid particles, presumably the remnants of the star-formation process, orbit around Vega and other stars and may provide the raw material for planetary systems. Emission from cool interstellar material has been traced throughout the Galaxy all the way to the galactic poles. Both the clumpiness and breadth of the distribution of this material were previously unsuspected. The far-infrared sky away from the galactic plane has been found to be dominated by spiral galaxies, some of which emit more than 50 percent and as much as 98 percent of their energy in the infrared-an exciting and surprising revelation. The IRAS mission is clearly the pathfinder for future missions that, to a large extent, will be devoted to the discoveries revealed by IRAS.     

Deposition of acidic species at a rural location in New South Wales,Australia

Wet-only rainwater composition on a daily basis, and atmospheric SO₂ and NO₂ concentrations on a monthly basis have been measured over a two year period at four sites ～100 km to the west of Sydney. Bulk aerosol composition on a monthly basis was also measured at one site. The study region is predominantly rural in character, but contains two coal-fired thermal power stations with a total installed capacity of 2320 MW, as well as several min or population centres, including a small city, with a total population of about 21,000. The measurement sites were located roughly on the perimeter of a circle of about 20 km radius having the power stations at its centre. Three of the sites were situated in rural settings, while the fourth was located on the outskirts of the small city of Lithgow. Atmospheric acid loadings at all sites were low by the standards usually associated with industrialised regions of Europe and North America, with about one third of rainwater total acidity provided by organic acids (formic, acetic and oxalic). At the three rural sites, total inorganic acid deposition, comprising measured wet deposition plus inferred dry deposition of acidic S and N species, averaged about 30 meq m^?2 y^?1, a low figure by most standards. At the site located near the city of Lithgow total deposition of acidic S and N species averaged about 80 meq m^?2 y^?1.     

Saturation of the southern ocean CO2 sink due to recent climate change

Based on observed atmospheric carbon dioxide (CO2) concentration and an inverse method, we estimate that the Southern Ocean sink of CO2 has weakened between 1981 and 2004 by 0.08 petagrams of carbon per year per decade relative to the trend expected from the large increase in atmospheric CO2. We attribute this weakening to the observed increase in Southern Ocean winds resulting from human activities, which is projected to continue in the future. Consequences include a reduction of the efficiency of the Southern Ocean sink of CO2 in the short term (about 25 years) and possibly a higher level of stabilization of atmospheric CO2 on a multicentury time scale.