Electron microscopic virus diagnosis in dogs, cats, calves, swine and foals in the year 1989     

U Biermann  K Schmitt  H Krauss 《Berliner und Münchener tier?rztliche Wochenschrift》1991,104(4):117-119

During 1989 fecal and gut samples of 598 dogs, 189 cats, 496 calves, 100 pigs and 66 foals with diarrhoea were investigated for virus by electron microscopy. In samples of dogs and cats Parvovirus was detected in 18.5% and 8.5% of the samples, respectively; Coronavirus was found in 14.9% and in 16.4% of the specimens. In samples of calves Coronavirus dominated with a detection rate of 37.5%, followed by Rotavirus with 10.7% and not clearly identifiable particles resembling Coronavirus (4.2%). In 7.1% of the specimens Rotavirus as well as Coronavirus was found. In 33% of specimens from piglets Coronavirus was detected. 10.6% of the faeces from foals contained Coronavirus-like particles. Between 1987 and 1989 the detection rate of Parvovirus in faeces from dogs and cats decreased from 24.2% to 18.6% and from 17.5% to 8.5%. Coronaviruses in calves, dogs and cats increased from 22.9% to 37.5%, from 5.6% to 14.9% and from 8.2% to 16.4% of the samples investigated.  相似文献   

Kinetics of formation and functional properties of conjugates prepared by dry-state incubation of beta-lactoglobulin/acacia gum electrostatic complexes     

Schmitt C  Bovay C  Frossard P 《Journal of agricultural and food chemistry》2005,53(23):9089-9099

The formation of conjugates between beta-lactoglobulin and acacia gum based on electrostatic complexes formed at pH 4.2 was investigated upon dry-state incubation for up to 14 days at 60 degrees C and 79% relative humidity (RH). By means of SEC-HPLC and RP-HPLC, it was shown that the beta-lactoglobulin incubated alone was able to form polymers with molecular masses higher than 200 kDa until 50% of the initial monomeric protein disappeared after 14 days. In the presence of acacia gum at initial protein to polysaccharide weight mixing ratios of 2:1 and 1:2, only 35% of the initial beta-lactoglobulin monomers disappeared after 14 days. Using RP-HPLC, an apparent reaction order of 2 was found for the disappearance of monomeric beta-lactoglobulin both in the presence or absence of acacia gum. However, the reaction rate was faster in the absence of acacia gum. SDS-PAGE electrophoresis with silver staining confirmed the formation of beta-lactoglobulin/acacia gum conjugates. The solubility curves of the incubated beta-lactoglobulin showed a minimum around pH 4-5. By contrast, the minimum of solubility of the beta-lactoglobulin/acacia gum incubated mixtures shifted to lower pH values compared to initial mixtures. The conjugates exhibited higher foam capacity than the incubated protein as well as lower equilibrium air/water surface tension. Conjugation at ratio 1:2 led to increased interfacial viscosity (300 mN s m(-1) at 0.01 Hz) compared to beta-lactoglobulin alone (100 mN s m(-1) at 0.01 Hz), but similar interfacial elasticity (30-40 mN m(-1)). The foam capacity of the conjugates was significantly higher than that of the incubated beta-lactoglobulin as well as foam expansion and drainage time, especially at pH 5.3, i.e., higher than the pH of formation of the conjugates.  相似文献   

Population differentiation and genetic variation inform translocation decisions for Liatris scariosa var. novae-angliae, a rare New England grassland perennial     

Kelly Gravuer  Eric von Wettberg  Johanna Schmitt 《Biological conservation》2005,124(2):155-167

Augmentation of small rare species populations is sometimes suggested on genetic grounds. However, outbreeding depression via dilution of local adaptation or break-up of genomic coadaptation may occur. These effects depend on the causes of population divergence. Here, we compare genetic measures of population divergence in Liatris scariosa var. novae-angliae, a rare New England perennial. We measured G_ST, neutral marker subdivision, and Q_ST, quantitative subdivision of propagule and juvenile plant traits. G_ST was relatively high. Q_ST for leaf shape exceeded G_ST, indicating local adaptation, while Q_ST for other traits fell within or below the G_ST range. Local adaptation appears low for juvenile traits, although the high G_ST cautions against translocation because of potential coadaptation. If translocation is still required, however, donor populations should contain high quantitative genetic diversity. We assess population size and allozyme diversity as predictors of quantitative genetic variation, but find these poor proxies for direct measurement.  相似文献   

Time and scale of gully erosion in the Jedliczny Dol gully system, south-east Poland     

Anne Schmitt  Jan Rodzik  Wojciech Zg&#x;obicki  Christian Russok  Markus Dotterweich  Hans-Rudolf Bork 《CATENA》2006,68(2-3):124

Key catchments of the Roztocze loess area in south-east Poland have a great potential of revealing the history of long-term soil erosion and changes in land use. The knowledge of how and when soil erosion took place in the past helps one understand the impact of land use changes on the landscapes [Bork, H.-R., 1989. Soil erosion during the past Millennium in Central Europe and its significance within the geomorphodynamics of the Holocene. Catena 15, 121–131]. The Jedliczny Dol gully system near the town Zwierzyniec in south-east Poland was investigated by using detailed field stratigraphy and radiocarbon dating of charcoal and wood.In connection with new settlements which were established between the 14th and 16th centuries, arable land was cultivated and forests were used much more intensively. As a consequence, the loess soils were strongly eroded during heavy rainfalls. Up to 4 m of colluvial sediments were deposited in the gully system during the 15th and/or 16th centuries. The thickness of the colluvial sediments indicate severe erosion which might be related to excessive timber exploitation for the local glass and iron production. With the foundation of the so-called Ordinariat Zamoyski at the end of the 16th century, some parts of the area were presumably reforested. High pressure on the land at the beginning of the 19th century enabled a second main phase of gulling before 1900.Since 1890 at the latest, almost the whole catchment is used as a forest, however, concentrated runoff on compacted forest roads can still be high after heavy rainfalls.In loess areas soil erosion caused by intensive land use, triggered by heavy rainfalls, can change the landscape drastically. These changes will continue to influence how catchments react, even if land use gets less intensive again. This knowledge should be considered regarding future, sustainable land use and recent changes in land use in the south-eastern Polish loess regions.  相似文献   

Effects of antibiotics on soil microorganisms: time and nutrients influence pollution-induced community tolerance     

Heike Schmitt  Heidi Haapakangas 《Soil biology & biochemistry》2005,37(10):1882-1892

A method for the detection of the effects of antibiotics on soil microbial communities was optimised in the present study. We investigated the influence of measurement time and nutrient status on the pollution-induced community tolerance (PICT), using the sulfonamide sulfachloropyridazine (SCP) as model compound. The tolerance development in soil microcosms that were exposed to SCP under different conditions was compared with the background tolerance in SCP-unexposed microcosms. The tolerance of bacterial extracts from the soil microcosms was determined in Biolog^® multiwell plates as the SCP sensitivity of a range of physiological processes. The background tolerance was not affected by soil nutrient amendments, but an influence of the inoculum density in the microtiter plates was observed. Still, the variance of the background tolerance was low, which is in favour of the usage of community tolerance measurements for a selective detection of a toxicant impact. In line with the assumptions of the PICT concept, soil amendment with SCP led to an increase in community tolerance. This tolerance development was enhanced upon additional soil amendment with fresh pig slurry, and less by alfalfa meal addition. Tolerance increases were observed after a soil exposure to SCP of only 7 days, possibly because nutrient input facilitates the fast adaptation of the soil microbial community. However, a further increase in exposure time led to variable changes in the observed tolerance. Prolonged tolerance detection in the microtiter plates (11 days) enabled a clearer differentiation between different soil treatments, as it better resolved the EC₅₀ values of processes with a high tolerance to bacteriostatic antimicrobial compounds. For the detection of antibiotic effects on soil microbial communities, it is therefore recommended to use nutrient amendments (possibly fresh pig slurry), to standardize the soil exposure time, and to extend the period of Biolog plate measurement beyond 7 days.  相似文献   

ON THE OXIDATIVE NATURE OF THE NERVE IMPULSE     

Schmitt FO 《Science (New York, N.Y.)》1930,72(1875):583-584

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ROSAT Detection of an X-ray Shadow in the 1/4-keV Diffuse Background in the Draco Nebula     

Snowden SL  Mebold U  Hirth W  Herbstmeier U  Schmitt JH 《Science (New York, N.Y.)》1991,252(5012):1529-1532

The detection by the Roentgen satellite (ROSAT) x-ray telescope of a shadow in the 1/4-kiloelectron volt (C band, 0.1 to 0.284 kiloelectron volt) cosmic diffuse background is reported. The location and morphology of the local minimum in x-rays are in clear agreement with a discrete H I cloud. The shadow is very deep with a minimum level at 50 percent of the surrounding emission; therefore, a minimum of 50 percent of the observed off-cloud flux must originate on the far side of the cloud. The analysis of H I velocity components links the cloud with the Draco nebula (distance approximately 600 parsecs); it then follows that there is significant 1/4-kiloelectron volt x-ray emission at a large distance (>400 parsecs) from the galactic plane along this line of sight. The extent of the distant emission region is uncertain, and, if it indicates the existence of a hot galactic corona, it must be patchy in nature.  相似文献   

A MECHANISM FOR THE COORDINATION AND REGULATION OF THE MOVEMENT OF CILIA OF EPITHELIA     

Grave C  Schmitt FO 《Science (New York, N.Y.)》1924,60(1550):246-248

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Rubidium-strontium age and elemental and isotopic abundances of some trace elements in lunar samples     

Murthy VR  Schmitt RA  Rey P 《Science (New York, N.Y.)》1970,167(3918):476-479

Data on six lunar crystalline rocks give an apparent Rb-Sr isochron age of 4.42 +/- 0.24 x 10(9) years (95 percent confidence limits) and initial (87)Sr/(86)Sr ratio similar to that in a basaltic achondrite. Relationships between K, Rb, Sr, and Ba and depletion of Eu in these samples point to plagioclase separation from the melts that produced these rocks. The abundance of (157)Gd in the three lunar samples is similar to terrestrial abundance within < 0.2 percent, thus setting a limit of < 6 x 10(15) neutrons per square centimeter for the integrated thermal neutron flux difference between lunar and terrestrial materials.  相似文献   

A Lunar Occultation of the Dust-Scattering Halo Around GX 5-1 Observed with ROSAT     

Predehl P  Schmitt JH  Snowden SL  Trümper J 《Science (New York, N.Y.)》1992,257(5072):935-937

The x-ray source GX 5-1 in the galactic bulge has been observed with the position-sensitive proportional counter onboard the R?ntgen satellite (ROSAT) during and after a lunar occultation. Extended emission around the source was unambiguously discovered while the central source was behind the lunar rim. This emission is interpreted as a dust-scattering halo around GX 5-1 that has a fractional intensity of 28 percent, implying a grain column density between GX 5-1 and Earth of approximately 3 x 10(10) per square centimeter. The halo derived from imaging during the ROSAT all-sky survey is identical to that obtained from the lunar occultation, thus demonstrating that the ROSAT x-ray mirror scattering has not changed as compared with the mirror properties as measured in preflight calibrations.  相似文献