Fluorescence of dietary porphyrins as a basis for real-time detection of fecal contamination on meat     

Ashby KD  Wen J  Chowdhury P  Casey TA  Rasmussen MA  Petrich JW 《Journal of agricultural and food chemistry》2003,51(11):3502-3507

Digestion of green plants in the gastrointestinal (GI) tract produces degradation products from chlorophyll that cause ingesta and feces to be highly fluorescent. This property was exploited for development and construction of instruments to noninvasively detect minute quantities of feces on meat samples in real time. The presence of feces on meat products is a primary source of foodborne pathogens, such as Escherichia coli O157:H7 and Salmonella. This new technology provides a rapid and accurate alternative to the practice of visual inspection and augments more time-consuming biological testing methods. This innovation can assist meat processors and government inspectors in their efforts to provide safe and wholesome food to consumers.  相似文献   

Mercury concentrations in walleyes from Wisconsin (USA) Lakes     

R. C. Lathrop  P. W. Rasmussen  D. R. Knauer 《Water, air, and soil pollution》1991,56(1):295-307

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The analysis of vegetation for total mercury     

Pat E. Rasmussen  Greg Mierle  Jerome O. Nriagu 《Water, air, and soil pollution》1991,56(1):379-390

Over four hundred vegetation samples were collected for total Hg determination as part of a biogeochemical survey in the Precambrian Shield region near Huntsville, Ontario. An objective of the survey was to obtain accurate data describing the spatial and temporal variation of Hg concentrations in vegetation. Five tree species, clubmosses, mosses, lichen and fungi were collected along three transects each 8 to 10 km long. The samples were digested using a hot H₂SO₄/HNO₃ mixture followed by cold-vapor AAS detection. Very low detection limits (less than 1.0 ng g⁻¹) were achieved by performing the analyses in a clean, Hg-free laboratory. The Hg concentration of coniferous needles did not vary significantly over eight weeks of the summer, but did vary significantly between first and second year growth. In all tree species examined, Hg concentrations in needles/leaves were two to three times as high (by dry weight) as that in twig tissue from the same branch. Differences in Hg content between tissues of different types and ages constituted a major source of within-site variation between plants of the same species.  相似文献   

Critical loads for nitrogen deposition on forest ecosystems   总被引：2，自引：0，他引：2  

E. - D. Schulze  W. De Vries  M. Hauhs  K. Rosén  L. Rasmussen  C. -O. Tamm  J. Nilsson 《Water, air, and soil pollution》1989,48(3-4):451-456

Critical loads for N deposition are derived from an ecosystem's anion and cation balance assuming that the processes determining ecosystem stability are soil acidification and nitrate leaching. Depending on the deposition of S, the parent soil material, and the site quality critical N deposition rates will range between 20 to 200 mmol m^?2 yr^?1 (3 to 14 kg ha^?1 yr^?1) on silicate soils and reach 20 to 390 mmol m^?2 yr^?1 (3 to 48 kg ha^?1) on calcareous soils.  相似文献   

Modelling ”clean rain” treatments in acidified soils-EXMAN project results     

Charlotta Walse  Claus Beier  Per Warfvinge  Lennart Rasmussen 《Water, air, and soil pollution》1995,85(3):1807-1812

The SAFE dynamic model was applied to a ”clean rain” roof experiment performed within the EXMAN project. In the experiment ambient throughfall was removed and replaced with artificial ”clean throughfall”. Input of S, N and H to the forest ecosystem was reduced by 75–100%. The results of the modelling show, that the time scales of model predictions and experiments are the same. The change in base cation flux was well reproduced, while the simulation of changes in aluminum flux was less successful. pH stayed constant in the experiment as well as in the calculations.  相似文献   

Characterization of interdigital glands in the Asian elephant (Elephas maximus).     

L W Lamps  B R Smoller  L E Rasmussen  B E Slade  G Fritsch  T E Goodwin 《Research in veterinary science》2001,71(3):197-200

In the Asian elephant, wetness akin to perspiration is commonly observed on the cuticles and interdigital areas of the feet; this observation has lead to speculation regarding the existence of an interdigital gland. Our goal was to search for interdigital glands and characterise them morphologically, histochemically, and immunohistochemically. Necropsy samples of interdigital areas from two Asian elephants were obtained. Multiple sections were fixed and processed routinely, then stained with hematoxylin/eosin and differential mucin stains. Immunohistochemistry was also performed for cytokeratins 8 and 10. Interdigital glands resembling human eccrine glands were detected deep within the reticular dermis. Histochemical staining indicated neutral mucopolysaccharides and nonsulphated acid mucopolysaccharides in glandular secretions, and the glandular epithelium also showed immunoreactivity to cytokeratins 8 and 10. Both the histochemical and immunohistochemical staining patterns are analogous to human eccrine structures. This study shows with certainty that Asian elephants possess sweat glands as they are defined histologically.  相似文献   

Renal excretion of digoxin in swine and goats.     

F Rasmussen  M Nawaz  E Steiness 《Acta veterinaria Scandinavica》1975,16(4):525-536

In experiments on swine and goats the renal excretion of digoxin was examined, and it was found that the renal clearance of non-protein-bound digoxin in swine was lower than creatinine clearance which expresses filtration clearance. Correlation analysis showed that the renal clearance of digoxin in swine was not significantly influenced by the concentration of non-protein-bound digoxin in plasma and the pH of the urine, while there was a significant positive correlation between the clearance and the urine flow rate (Table 4). On the other hand, the renal clearance of digoxin in goats was significantly influenced by the concentration of non-proteinbound digoxin in plasma and by urine pH (Table 4). From these results it is concluded that glomerular filtration and back-diffusion are involved in the renal handling of digoxin in both swine and goats. In addition active tubular secretion is also involved in the renal excretion of digoxin in goats.  相似文献   

Pharmacokinetics of phenylbutazone and oxyphenabutazone in the pig.          下载免费PDF全文

E F Hvidberg  F Rasmussen 《Canadian journal of veterinary research》1975,39(1):80-88

The kinetics of phenylbutazone (pbz) and its main metabolite oxyphenbutazone (oxpbz) were investigated in seven pigs in order to determine if this animal might serve as a model for human investigations. The study was performed in two stages, one as single dose experiments using intravenous injection, the second as infusion experiments. The rate of elimination for both compounds was demonstrated to be much faster than in man. Similar results have been observed in several other animal species. The degree of protein binding (pbz 98%, ox-pbz 97%), the apparent specific volume of distribution (pbz 0.18 1/kg, ox-pbz 0.28 1/kg) and the renal clearance were found to be similar to results obtained in man and rat. Ox-pbz had a higher renal clearance (0.13 ml/min/kg) than pbz (0.003 ml/min/kg) but still the renal excretion constituted only a small fraction of the total elimination (pbz 0.5%, ox-pbz 5%). Provided real steady state conditions were obtained during the infusion experiments calculations based on the results from the single dose experiments in the same animal revealed that between 20 and 60% of the injected pbz was metabolized to the ring-hydroxylation product (ox-pbz). It is concluded that the pig model is not superior to other animal models for studies of pbz/ox-pbz. The rapid elimination pattern is the main problem in relation to human investigations.  相似文献   

Tissue damage and concentration at the injection site after intramuscular injection of chemotherapeutics and vehicles in pigs.     

F Rasmussen  O Svendsen 《Research in veterinary science》1976,20(1):55-60

Intramuscular injection sites were examined for macroscopical and microscopical changes and for residues of drugs six and 30 days after injection of chemotherapeutic preparations or vehicles in swine. The chemotherapeutic preparations contained sulphonamide and/or trimethoprim. All the chemotherapeutic preparations and the vehicles except physiological saline and sterile water caused macroscopical and microscopical changes, mainly appearing as areas of necrotic muscle tissue six days after the injection and as scar tissue 30 days after the injection. Residues of drugs were found at nearly all the injection sites six days after the injection, while 30 days after the injection only residues of sulphonamides were detectable in nearly half of the injection sites.  相似文献   

The role of flower and leaves in cut flower water uptake     

W.J. Carpenter  H.P. Rasmussen 《Scientia Horticulturae》1974,2(3):293-298

Removal of the cut rose flower of ‘Forever Yours’ decreased water uptake by 20.4%, leaf removal 78.5%, and both flower and leaf removal 95.2%. Cut carnation ‘White Sim’ water uptake declined 27.1, 37,3 and 59.6% after flower, leaf, or both were removed, respectively. A high rate of water uptake (40.4%) continued after both carnation flower and leaf removal.  相似文献