Gypsum Precipitation – A Medium to Control Sulphate Pollution of Freshwater Sediment Leachates     

Fajtl  Jiří  Tichý  Richard  Ledvina  Rostislav 《Water, air, and soil pollution》2002,135(1-4):141-156

To treat sulphate pollution resulting from freshwater sediments,an experimental study was done. This experimental study was carried out to determine the effects of pH values and calcium supplements (as CaCl₂) on the formation of gypsum in a representative wetland sediment that was aerated. It was foundthat the differences between dissolved sulphate in untreatedcontrol and the other treatments with CaCl₂ amendments canbe attributed to the precipitation of gypsum. At the same time, the system was highly affected by Ca adsorption/desorption thatwas controlled by pH values. ECOSAT equilibrium simulations showed that CaCl₂ additions (0.2–0.3 mol L^-1) to aerated freshwater sediment resulted in removal of 78–98% ofsulphate (from its total content) from the solution. It wascaused by favourable conditions for gypsum formation i.e. acidicpH values were not increased due to the neutral character of CaCl₂. On the contrary to CaCl₂ amendments, CaCO₃supplements (in the same Ca doses as applied in CaCl₂) caused the removal of only 5–25% of sulphate. The significantincrease of pH values after the application of CaCO₃ limitedgypsum formation due to high saturation of the system with CO₃ ^-2 and HCO₃ ^-. It resulted in the prevalence of CaCO₃ formation in this system. However, theaddition of Cl^- can facilitate the mobilisation of cationicmetals like Cd and Pb in the form of Cl^--complexes. Therefore, CaCl₂ treatment should be used in the sites thatdo not contain elevated amounts of these metals.  相似文献   

On the potential of documenting decadal-scale avifaunal change from before-and-after comparisons of museum and observational data across North America     

Fernando Machado-Stredel  Benedictus Freeman  Daniel Jiménez-Garcia  Marlon E.Cobos  Claudia Nu?ez-Penichet  Laura Jiménez  Ed Komp  Utku Perktas  Ali Khalighifar  Kate Ingenloff  Walter Tapondjou  Thilina de Silva  Sumudu Fernando  Luis Osorio-Olvera  A.Townsend Peterson 《中国鸟类》2022,(1):1-10

Studies of biodiversity dynamics have been cast on either long(systematics)or short(ecology)time scales,leaving a gap in coverage for moderate time scales of de...  相似文献   

Thrombocytopenia in Horses: 35 Cases (1989–1994)     

Debra C. Sellon  Jay Levine  Everett Millikin  Kate Palmer  Carol Grindem  Patrice Covington 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1996,10(3):127-132

The records of 3,952 equine patients presenting to the Veterinary Teaching Hospital at North Carolina State University College of Veterinary Medicine were evaluated to determine risk factors associated with thrombocytopenia. Of 2,346 horses from which a CBC was obtained, 35 (1.49%) were thrombocytopenic (platelet count < 75,000/μL). A reference population of 189 horses with normal platelet counts (75,000 to 300,000/μL) was also studied. Standardbred horses were at increased risk for thrombocytopenia. but age and gender were not identified as significant risk factors. Horses with infectious or inflammatory diseases were at increased risk for thrombocytopenia. The potential association of clinical and clinicopathologic factors with thrombocytopenia were assessed by reviewing a series of multiple logistic regression models. Clinical and clinicopathologic variables significantly associated with thrombocytopenia in the final model included increased PCV, increased band neutrophil count, increased total WBC, and decreased plasma protein concentration. Increased mature neutrophil count was associated with normal platelet counts. Thrombocytopenic horses were significantly more likely to die or be euthanized than were horses with normal platelet counts. J Vet Intern Med 1996;10:127–132. Copyright © 1996 by the American College of Veterinary Internal Medicine .  相似文献   

PRRSV planned exposure and the law     

O'Rourke K 《Journal of the American Veterinary Medical Association》2005,226(9):1461-1462

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Prion study raises questions     

O'Rourke K 《Journal of the American Veterinary Medical Association》2005,226(5):677-678

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AAHA dental care guidelines for dogs and cats     

Holmstrom SE  Bellows J  Colmery B  Conway ML  Knutson K  Vitoux J;AAHA 《Journal of the American Animal Hospital Association》2005,41(5):277-283

The purpose of this document is to provide guidelines for the practice of companion animal dentistry for the veterinary profession. Dental care is necessary to provide optimum health and quality of life. Diseases of the oral cavity, if left untreated, are often painful and can contribute to other local or systemic diseases. This paper includes guidelines for materials and equipment, dental cleaning and evaluation, client communication, and pet home care.  相似文献   

New form of BSE sparks discussion     

O'Rourke K 《Journal of the American Veterinary Medical Association》2004,224(8):1233-1234

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The catch-22 in regulating the slaughter industry. USDA encourages improvements in animal welfare at slaughterhouses     

O'Rourke K 《Journal of the American Veterinary Medical Association》2004,225(9):1318-1319

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Use of a jugular vein autograft for reconstruction of the cranial vena cava in a dog with invasive thymoma and cranial vena cava syndrome   总被引：1，自引：0，他引：1  

Holsworth IG  Kyles AE  Bailiff NL  Hopper K  Long C  Ilkiw JE 《Journal of the American Veterinary Medical Association》2004,225(8):1205-10, 1196

A spayed female dog was evaluated because of edema of the ventral cervical region, lethargy, cough, and reduced exercise tolerance. Invasive thymoma and cranial vena cava syndrome were diagnosed by use of ultrasound-guided fine-needle biopsy and contrast-enhanced helical computed tomography. Resection of the cranial vena cava and an autogenous jugular vein graft were used for restoration of normal venous return to the right atrium and alleviation of the cranial vena cava syndrome.  相似文献   

Veterinary response teams proliferate. Veterinarians train for disease outbreaks and disasters     

O'Rourke K 《Journal of the American Veterinary Medical Association》2004,225(8):1173

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