Prevalence of some internal parasites found (1971–1989) in horses born on a farm in central kentucky     

E.T. Lyons PhD  J.H. Drudge DVM  ScD  S.C. Tolliver BS 《Journal of Equine Veterinary Science》1990,10(2)

Prevalence of several species of naturally acquired internal parasites are reported from a total of 97 horses (mostly mixed lighthorse type) from a farm in central Kentucky. The horses were born and raised in 2 adjacent fields (No. 4 - n=44 and No. 10 − n=53) over a 19-year-period (1971–1989). They were 100 to 537 days old (av. 281) when examined; an exception was a 819-day-old not calculated in the average age. Some of the horses were not examined for all of the parasites. These horses (never previously treated) were all used in critical or controlled tests for evaluation of antiparasitic activity of drugs. Dams and other horses in the fields rarely were given an antiparasitic compound.Prevalence and aggregate mean numbers of parasites in infected animals (in parentheses) for the 97 horses are: bots — Gasterophilus intestinalis 2nd instar, 65%(45), 3rd instar, 96%(210), Gasterophilus nasalis 2nd instar, 18%(10), 3rd instar, 63%(10); stomach worms — Habronema muscae, 73%(78), Draschia megastoma, 42%(53); ascarids — Parascaris equorum mature, 75%(45), immature 36%(29), tapeworms — Anoplocephala perfoliata, 33%(7); large strongyles — Strongylus vulgaris, 95%(80) (data on horses ≥180 days old), Strongylus edentatus, 94%(34) (data on horses ≥330 days old); pinworms — Oxyuris equi, 43%(87); eyeworms — Thelazia lacrymalis, 61%(6); S. vulgaris in cranial mesenteric artery, 92%(53); and S. edentatus in ventral abdominal wall, 98% (56). Differentiation was made for the data by season and by age of the horses when they were examined. Information from this research reflects the transmission patterns and prevalence of these parasites under natural conditions.  相似文献   

Occurrence of peptide and clavine ergot alkaloids in tall fescue grass   总被引：8，自引：0，他引：8  

P C Lyons  R D Plattner  C W Bacon 《Science (New York, N.Y.)》1986,232(4749):487-489

Evidence is presented that ergot alkaloids are ubiquitous in tall fescue pastures infected with the clavicipitaceous fungal endophyte Sphacelia typhina (or Acremonium coenophialum). Ergopeptide alkaloids, predominantly ergovaline, constituted 10 to 50 percent of the total ergot alkaloid concentration, which was as high as 14 milligrams per kilogram in sheaths and 1.5 milligrams per kilogram in blades. Ergot alkaloid concentrations were substantially increased by application of large amounts (10 millimoles per liter) of potassium nitrate or ammonium chloride to infected plants in the greenhouse. The results indicate that ergot alkaloids are probably responsible for the toxicity to cattle of this common pasture and lawn grass and that ergotism-like toxicoses may be caused by clavicipitaceous fungi other than Claviceps.  相似文献   

Sulfate and nitrate concentrations from a South greenland ice core     

Mayewski PA  Lyons WB  Spencer MJ  Twickler M  Dansgaard W  Koci B  Davidson CI  Honrath RE 《Science (New York, N.Y.)》1986,232(4753):975-977

An ice core in south Greenland covering the period 1869 to 1984 was analyzed for oxygen isotopes and chloride, nitrate, and sulfate concentrations. The data show that the "excess" (nonsea-salt) sulfate concentration has tripled since approximately 1900 to 1910 and the nitrate concentration has doubled since approximately 1955. The increases may be attributable to the deposition of these chemical specis from air masses carrying North American and Eurasian anthropogenic emissions.  相似文献   

Which uncertainty? Using expert elicitation and expected value of information to design an adaptive program     

Michael C. Runge  Sarah J. Converse  James E. Lyons 《Biological conservation》2011,(4):1214-1223

Natural resource management is plagued with uncertainty of many kinds, but not all uncertainties are equally important to resolve. The promise of adaptive management is that learning in the short-term will improve management in the long-term; that promise is best kept if the focus of learning is on those uncertainties that most impede achievement of management objectives. In this context, an existing tool of decision analysis, the expected value of perfect information (EVPI), is particularly valuable in identifying the most important uncertainties. Expert elicitation can be used to develop preliminary predictions of management response under a series of hypotheses, as well as prior weights for those hypotheses, and the EVPI can be used to determine how much management could improve if uncertainty was resolved. These methods were applied to management of whooping cranes (Grus americana), an endangered migratory bird that is being reintroduced in several places in North America. The Eastern Migratory Population of whooping cranes had exhibited almost no successful reproduction through 2009. Several dozen hypotheses can be advanced to explain this failure, and many of them lead to very different management responses. An expert panel articulated the hypotheses, provided prior weights for them, developed potential management strategies, and made predictions about the response of the population to each strategy under each hypothesis. Multi-criteria decision analysis identified a preferred strategy in the face of uncertainty, and analysis of the expected value of information identified how informative each strategy could be. These results provide the foundation for design of an adaptive management program.  相似文献   

Molybdenum isotope evidence for widespread anoxia in mid-Proterozoic oceans   总被引：2，自引：0，他引：2  

Arnold GL  Anbar AD  Barling J  Lyons TW 《Science (New York, N.Y.)》2004,304(5667):87-90

How much dissolved oxygen was present in the mid-Proterozoic oceans between 1.8 and 1.0 billion years ago is debated vigorously. One model argues for oxygenation of the oceans soon after the initial rise of atmospheric oxygen approximately 2.3 billion years ago. Recent evidence for H(2)S in some mid-Proterozoic marine basins suggests, however, that the deep ocean remained anoxic until much later. New molybdenum isotope data from modern and ancient sediments indicate expanded anoxia during the mid-Proterozoic compared to the present-day ocean. Consequently, oxygenation of the deep oceans may have lagged that of the atmosphere by over a billion years.  相似文献   

New phases of c60 synthesized at high pressure     

Iwasa Y  Arima T  Fleming RM  Siegrist T  Zhou O  Haddon RC  Rothberg LJ  Lyons KB  Carter HL  Hebard AF  Tycko R  Dabbagh G  Krajewski JJ  Thomas GA  Yagi T 《Science (New York, N.Y.)》1994,264(5165):1570-1572

The fullerene C(60) can be converted into two different structures by high pressure and temperature. They are metastable and revert to pristine C(60) on reheating to 300 degrees C at ambient pressure. For synthesis temperatures between 300 degrees and 400 degrees C and pressures of 5 gigapascals, a nominal face-centered-cubic structure is produced with a lattice parameter a(o) = 13.6 angstroms. When treated at 500 degrees to 800 degrees C at the same pressure, C(60) transforms into a rhombohedral structure with hexagonal lattice parameters of a(o) = 9.22 angstroms and c(o) = 24.6 angstroms. The intermolecular distance is small enough that a chemical bond can form, in accord with the reduced solubility of the pressure-induced phases. Infrared, Raman, and nuclear magnetic resonance studies show a drastic reduction of icosahedral symmetry, as might occur if the C(60) molecules are linked.  相似文献   

THE IMPORTANCE OF GEOGRAPHICAL RESEARCH     

Lyons HG 《Science (New York, N.Y.)》1915,42(1087):585-597

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Radar detection of cloud-seeding effects   总被引：1，自引：0，他引：1  

Hobbs PV  Lyons JH  Locatelli JD  Biswas KR  Radke LF  Weiss RR  Rangno AL 《Science (New York, N.Y.)》1981,213(4513):1250-1252

The effects on precipitation of artificially seeding clouds with Dry Ice have been monitored from cloud to ground with a radar that has a wavelength of 8.6 millimeters.  相似文献   

Active microbial sulfur disproportionation in the Mesoproterozoic     

Johnston DT  Wing BA  Farquhar J  Kaufman AJ  Strauss H  Lyons TW  Kah LC  Canfield DE 《Science (New York, N.Y.)》2005,310(5753):1477-1479

The environmental expression of sulfur compound disproportionation has been placed between 640 and 1050 million years ago (Ma) and linked to increases in atmospheric oxygen. These arguments have their basis in temporal changes in the magnitude of 34S/32S fractionations between sulfate and sulfide. Here, we present a Proterozoic seawater sulfate isotope record that includes the less abundant sulfur isotope 33S. These measurements imply that sulfur compound disproportionation was an active part of the sulfur cycle by 1300 Ma and that progressive Earth surface oxygenation may have characterized the Mesoproterozoic.  相似文献   

RESOLUTIONS ADOPTED BY THE INTERNATIONAL GEODETIC AND GEOPHYSICAL UNION     

Lallemand C  Lyons HG 《Science (New York, N.Y.)》1928,67(1729):196-197

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