Feeding patterns in five predatory fishes of the high Paranà River floodplain (PR, Brazil)     

V. L. L. de  Almeida  N. S. Hahn  A. E. A. de M. Vazzoler 《Ecology of Freshwater Fish》1997,6(3):123-133

Abstract— Between March 1992 and February 1993 five piscivorous fish species, Acestrorhynchus lacustris (Reinhardt, 1874), Hoplias malabaricus (Bloch, 1794), Rhaphiodon vulpinus Agassiz, 1829, Salminus maxillosus , Valenciennes, 1840 and Plagioscion squamosissimus (Heckel, 1840), of the high Paranà River floodplain showed a wide total prey spectrum though only three to four taxa were dominant in their diet. Shrimp, Macrobrachium amazonicum , were also common to the majority of species. Seasonal and spatial variations occurred throughout the study period probably due the availability of prey species. The main resources shared by the predators were also the most abundant in the area, with consumption markedly focused on prey about 5.0 cm long. Detrended correspondence analysis was effective in discriminating two groups of predators species that exploited distinct microhabitats. The predators with the least scores consumed small characids that inhabit mid-water or the littoral region, whereas those with the largest scores consumed prey associated to the bottom.  相似文献   

In vitro fertilization and further development of deep-frozen/thawed mouse oocytes     

U Michaelis  M Rubin  J Hahn 《DTW. Deutsche tier?rztliche Wochenschrift》1985,92(1):16-18

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Rhodococcus equi-associated osteomyelitis in foals     

EC FIRTH  MR ALLEY†  H HODGE 《Australian veterinary journal》1993,70(8):304-307

Two cases of Rhodococcus equl infection in foals are described, in which osteomyelitis was a feature. Because rhodococcal infection is usually low grade and chronic, and because the signs of early metaphysitis can be subtle, any articular or periarticular swelling in a foal from a farm with a history of rhodococcosis should be strongly suspected to be associated with R equl until proven otherwise.  相似文献   

Resistance to Sclerotinia sclerotiorum of 'high oleic' sunflower inbred lines     

S. Ronicke    V. Hahn  W. Friedt 《Plant Breeding》2005,124(4):376-381

Cultivation of sunflower (Helianthus annuus L.) is strongly affected by Sclerotinia sclerotiorum. To identify new sources of genetic diversity for sunflower breeding 25 sunflower inbred lines were analysed using eight Amplified Fragment Length Polymorphism (AFLP) primer combinations and their genetic similarities (GS) were estimated. Data were used to develop a Unweighted Pair Group Method using Arithmetic Averages (UPGMA) dendrogram. GS values of 0.58‐0.98 were observed but with no separate groupings dependant on oil quality. The inbred lines were screened for their reaction to inoculation with Sclerotinia sclerotiorum (Lib.) de Bary. Sunflower heads were artificially inoculated with S. sclerotiorum in three environments. Head infection was monitored after 1 week (lesion length) and 2 weeks (head rot). The F5 generation of a cross between a resistant (SWS‐B‐04) and a susceptible inbred line (SWS‐B‐01) was also tested for sclerotinia reaction across three environments. Significant differences in sclerotinia resistance, moderate heritabilities and a high correlation between the two assessments were observed. Inbred lines with a high level of resistance could be identified. These lines can be used for further breeding to improve sunflower sclerotinia resistance and to develop superior new hybrids.  相似文献   

Interspecific hybrids of sunflower as a source of Sclerotinia resistance     

S. Rönicke    V. Hahn    R. Horn    I. Grone    L. Brahm    H. Schnabl  W. Friedt 《Plant Breeding》2004,123(2):152-157

Sclerotinia sclerotiorum is considered the most devastating pathogen of sunflower grown in humid environments. In this study, progenies of partial hybrids between Helianthus maximiliani, a wild species that has been shown to be resistant to S. sclerotiorum, and H. annuus were characterized by amplified fragment length polymorphism (AFLP) analysis to identify whether there are introgressions from H. maximiliani into the cultivated sunflower at the molecular level. Wild species‐specific fragments as well as fragments not found in either parent were detected. Progenies tended to cluster together according to the original partial hybrids in the dendrogram by the use of bootstrap procedures. The progenies were studied for their reaction to S. sclerotiorum using artificial inoculation of sunflower heads. Some of the progenies showed a higher level of resistance compared with resistant inbred lines. It was possible to identify two AFLP‐fragments which seem to be linked to Sclerotinia resistance.  相似文献   

Optimal allocation of resources in evaluating current sunflower inbred lines for resistance to Sclerotinia     

J. Degener  A. E. Melchinger  V. Hahn 《Plant Breeding》1999,118(2):157-160

Sclerotinia sclerotiorum (Lib.) de Bary is a major limiting factor for sunflower (Helianthus annuus) production. This study was conducted to (1) evaluate a large number of current sunflower lines for their reaction to Sclerotinia, and (2) determine the optimum allocation of resources for their selection. A set of 85 inbred lines was screened under artificial leaf infection in three environments. The test revealed ample variation for all resistance traits in the current germplasm. A line selected from NDBLOS, an oilseed sunflower germplasm poo, and its derivatives were most resistant to Sclerotinia. Lines derived from interspecific crosses with the wild species Helianthus tuberosus and Helianthus argophyllus also showed satisfactory Sclerotinia resistance. The evaluation of five plants per plot in two replications and four environments appears to be a reasonable allocation of resources in order to optimize the selection response.  相似文献   

RADIO-IRON IN PLASMA DOES NOT EXCHANGE WITH HEMOGLOBIN IRON IN RED CELLS     

Hahn PF  Bale WF  Ross JF  Hettig RA  Whipple GH 《Science (New York, N.Y.)》1940,92(2380):131-132

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ABOLISHMENT OF ALIMENTARY LIPEMIA FOLLOWING INJECTION OF HEPARIN     

Hahn PF 《Science (New York, N.Y.)》1943,98(2531):19-20

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Approaches to environmental regulation: controlling chemicals and loading the dice     

Dowlatabadi H  Hahn RW 《Science (New York, N.Y.)》1986,233(4767):990-991

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Response: brain "identifier sequence"     

Owens GP  Chaudhari N  Hahn WE 《Science (New York, N.Y.)》1986,234(4779):1006

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