Effects on microflora of using naphthalene or X-rays to reduce arthropod populations in the field

Summary Naphthalene or X-rays are often used to test the effect on soil processes of reducing or eliminating arthropods. Naphthalene, however, is shown here to reduce radial growth significantly in eight out of nine basidiomycete fungi tested. X-ray treatment, which killed only 24% of Onychiurus latus Gisin (Collembola), significantly reduced the radial growth rate of one of two fungi tested. These techniques are likely to affect the composition of microbial communities and therefore should be used only with extreme caution in field manipulation experiments involving fauna-microflora interactions.Dedicated to the late Prof.Dr. M.S. Ghilarov     

Interaction between two decomposer basidiomycetes and a collembolan under Sitka spruce: Distribution,abundance and selective grazing

The fungi Mycena galopus (Pers. ex Fr.) Kummer and Marasmius androsaceus (L. ex Fr.) Fr. produced over 99% of the fruit bodies on a site under Picea sitchensis Carr. In the laboratory M. androsaceus colonized litter from both the L and F₁ horizons more than twice as fast as M. galopus, but in the field its distribution was restricted to the L horizon whereas M. galopus occurred in the F₁ horizon. The collembolan Onychiurus latus Gisin, the most abundant mycophagous arthropod at the field site which consistently had basidiomycete hyphae in its gut, was found throughout the autumn in the litter horizons in densities up to 600 m^?2. This collembolan showed a marked preference for the mycelium of M. androsaceus rather than that of M. galopus in both laboratory and field tests. These results suggest that selective grazing by O. latus may be an important factor in determining the vertical distribution of these two fungi in the field.     

Trace element discharges from coal combustion for power production

Partition factors have been calculated to describe the distribution of 38 elements between slag, total fly ash, atmospherically emitted fly ash, and vapors for a coal fired steamplant. These factors have been generalized to other types of boilers, to calculate the annual U.S. discharge of trace elements due to coal combustion for power production. The magnitude of trace element mobilization by coal combustion is compared with industrial consumption of trace elements, and with estimates of their natural mobilization by weathering. Elemental flows due to coal consumption are never less than 1.5% of their weathering mobilization, and coal combustion introduces As, Co, Cu, Fe, Hg, Mo, Ni, Pb, Sc, Se, U, V, and Zn into the environment at rates comparable to their rates of introduction by weathering.     

Recruitment and Commercial Seed Procurement of the Blue Mussel Mytilus edulis in Maine

A thorough understanding of recruitment in the blue mussel is necessary if the new industry is to maximize seed procurement without impinging upon other fisheries. Larval appearance is a relatively precise event in Maine, cued to early summer water temperature of 10–12 C and, apparently, full moon spawning events. Mussel larvae are more abundant on the flood tides indicating inshore and estuarine retention, although this retention relates to the morphometry and relative energy of the system. Webb Cove, a wide embayment with maximum sample station current velocity of 0.2 m/s, showed a random ebb tide vs. flood tide larval distribution; the narrow, long Damariscotta River estuary with 0.35 m/s current velocity showed a two-fold flood tide larval enhancement and the Jordan River with 1.5 m/s current velocities showed up to a 14-fold flood tide enhancement of mussel larvae and bysally drifting juveniles. Thus certain Maine estuaries may act as larval traps, providing areas of concentrated settlement and seed abundance. Primary setting normally begins with a large initial pulse in June followed by one or more secondary pulses throughout the summer. Secondary settlement (reattachment of bysally drifting juveniles) occurs at lower levels throughout the year, especially in late July and early August. Maximum attachment of larvae and juveniles occurs during periods of maximum current velocity. Extensive eelgrass beds at the mouths of some estuaries (i.e., Jordan River) may be the sites of extensive primary and secondary setting. Great Eastern Mussel Farms, the industry component, guided by these studies, is testing the deployment of live and shell mussel cultch to develop and optimize a new seed procurement system.     

Generation and maintenance of gradients in taxonomic diversity

Latitudinal gradients in diversity of organisms represent an equilibrium distribution for at least the last 270 x 10(6) years. Faunas endemic to tropical regions evolved significantly faster than extra-tropical faunas. The latitude-dependent difference in rates of evolution also represents an equilibrium condition for at least the last 270 x 10(6) years and has consequences for paleontological correlation of rocks because the attainable resolution depends on rate of evolution and will thus be greater in tropic regions than in extra-tropical ones.     

Impact of Space Research on Science and Technology: Space techniques have provided new tools for science and applications

Science and technology are themselves a part of our modern culture. They contribute to the arts, furnish new media for human expression, provide better and new musical instruments and improved acoustics for enriched enjoyment of them, and give the artist new materials and techniques for his work. They enrich the humanities in furnishing man with a broader basis for understanding himself, his potentialities, and his place in nature. The historian has a better approach to his subject because of scientific methodology. The archeologist has a surer grasp on temporal relationships because of the tools that physics and chemistry give him for dating materials and identifying their sources. Slowly, an entire world absorbs the increased understanding of man and nature that science generates, and reflects that understanding in its literature, its social, political, and economic institutions, and its application to human daily living. Today, much of the world's population is aware of the world as a body of a solar system in a galaxy among millions of other galaxies. These people can conceive of man in a historical and cosmological perspective that did not exist in centuries past. As this understanding and these concepts spread to more and more of the world's people, it may be hoped that this common bond of understanding will not only give increased motivation to solve peaceably the problems that beset the world, but will also provide increased means for doing so.     

Report from the conference, ‘identifying obstacles to applying big data in agriculture’

Precision Agriculture - Data-centric technology has not undergone widespread adoption in production agriculture but could address global needs for food security and farm profitability. Participants...     

Incidence of contralateral versus ipsi-lateral neurological signs associated with lateralised Hansen type I disc extrusion

Asymmetrical neurological signs were noted in 50 dogs presenting with Hansen type I thoracolumbar disc extrusion. Thoracolumbar myelograms and surgical decompression were performed in all cases. Dogs were divided into two groups (acute and chronic) based on the duration of clinical signs prior to presentation to the University of Georgia. Lateralising extradural cord compressive lesions were noted on all myelograms. In the acute group, 35 per cent of the dogs had asymmetrical neurological signs contralateral to the myelographic and surgical lesion, while in the chronic group only 11 per cent had neurological signs contralateral to the lesion. There was found to be no significant difference in frequency of contralateral asymmetrical clinical signs between the two groups (Fischer's exact test; P = 0–095). The high frequency of contralateral signs documents the importance of thoracolumbar myelography for accurate localisation of the disc material before decompressive surgery.     

SONOGRAPHIC AND SCINTIGRAPHIC EVALUATION OF ACUTE RENAL ALLOGRAFT REJECTION IN CATS

The sonographic features of acute renal allograft rejection in humans and dogs are manifested by increase in renal cross-sectional area and reduction in renal cortical blood flow. These changes have not been investigated in cats. The objectives of this study were to evaluate sonographic and scintigraphic changes during acute renal allograft rejection in cats. Eight SPF, intact, adult, male cats received heterotopic renal allotransplantations. Immunosuppressive doses of cyclosporine and prednisolone were administered for 14 days and then discontinued to allow acute allograft rejection to occur. Serial measurements of renal cross-sectional area, resistive index (RI), echogenicity, and glomerular filtration rate (GFR) were performed to evaluate changes during acute rejection. Upon sonographic confirmation of absent diastolic blood flow or a 20% increase in cross-sectional area of the allograft, a nephrectomy and histopathologic evaluation were performed. Acute allograft rejection was confirmed histologically in all cats. Significant increases in renal cross-sectional area (P < 0.001) occurred postoperatively and during rejection. There were no significant changes in RI (P = 0.43) at any time. A subjective increase in medullary echogenicity and a decrease in corticomedullary demarcation were observed in the rejection period. While GFR decreased significantly in the immediate postoperative period (P < 0.001), no further change occurred during rejection (P = 0.42). Changes in RI and GFR do not appear to be sensitive indicators of acute renal allograft rejection in cats. Serial measurements of renal cross-sectional area appear to be a sensitive method for the early diagnosis of allograft rejection in feline renal transplant recipients.