Effect of dietary niacin supplementation on serum constituents of periparturient dairy cattle     

G S Dufva  E E Bartley  T G Nagaraja  A D Dayton  R A Frey 《American journal of veterinary research》1984,45(9):1838-1841

A total of 60 multiparous periparturient Holstein cows were used to determine the differences in serum constituents between cows given supplemental niacin in the diet and cows not given supplemental niacin. Serum inorganic phosphorus concentration was consistently higher (P less than 0.10) and serum potassium, total calcium, and sodium concentrations and alkaline phosphatase activities were consistently lower in cows given supplemental niacin than in cows not given supplemental niacin. Serum chloride, creatinine, and albumin values also tended to be lower in niacin-supplemented cows. Serum total protein tended to be slightly higher in niacin-supplemented cows. There was no consistent difference in urea nitrogen between groups of cows.  相似文献   

Comparative lethal effects on mice of ruminal fluid from cattle fed hay or grain.     

T G Nagaraja  J R Wilson  E E Bartley  L R Fina  H D Anthony 《American journal of veterinary research》1979,40(6):770-773

Strained ruminal fluid from cattle fed hay or grain was lethal to mice when injected intraperitoneally, but the fluid from grain-fed cattle was approximately 3.7 times more toxic than that from hay-fed cattle. The lethal factor(s) was not resistant to heat, was nondialyzable, was retained on Seitz and membrane filters, and was associated with the bacterial fraction of ruminal fluid. We concluded that death of the mice resulted from infection produced by facultative bacteria normally in ruminal fluid. Ruminal fluid from grain-fed cattle contained a greater number of facultative bacteria than did that from hay-fed cattle.  相似文献   

Chemically induced fast solid-state transitions of omega-VOPO4 in vanadium phosphate catalysts     

Conte M  Budroni G  Bartley JK  Taylor SH  Carley AF  Schmidt A  Murphy DM  Girgsdies F  Ressler T  Schlögl R  Hutchings GJ 《Science (New York, N.Y.)》2006,313(5791):1270-1273

Vanadium phosphates are important catalysts for the oxidation of alkanes, and commercial catalysts comprise a complex range of V4+ and V5+ phosphates. We used three complementary in situ characterization methodologies-powder x-ray diffraction and laser Raman and electron paramagnetic resonance spectroscopies-to show that the metastable phase omega-VOPO4 is very sensitive to many of the reactants and products of butane oxidation. A rapid transformation from omega-VOPO4 to delta-VOPO4 occurs on exposure to butane at the reaction temperature, and hence the metastable omega-VOPO4 may play a role in the formation of commercial catalysts.  相似文献   

Increased Toxoplasma gondii positivity relative to age in 125 Scottish sheep flocks; evidence of frequent acquired infection     

Katzer F  Brülisauer F  Collantes-Fernández E  Bartley PM  Burrells A  Gunn G  Maley SW  Cousens C  Innes EA 《Veterinary research》2011,42(1):121

Toxoplasma gondii seroprevalence was determined in 3333 sheep sera from 125 distinct sheep flocks in Scotland, with the majority of flocks being represented by 27 samples, which were collected between July 2006 and August 2008. The selected farms give a representative sample of 14 400 sheep holdings identified in the Scottish Government census data from 2004. Overall T. gondii seroprevalence, at individual sheep level, was determined to be 56.6%; each flock tested, had at least a single positive animal and in four flocks all ewes tested positive. The seroprevalence of sheep increased from 37.7% in one year old stock to 73.8% in ewes that were older than six years, showing that acquired infections during the life of the animals is frequent and that environmental contamination by T. gondii oocysts must be significant. The median within-flock seroprevalence varied significantly across Scotland, with the lowest seroprevalence of 42.3% in the South and the highest seroprevalence of 69.2% in the far North of Scotland and the Scottish Islands, while the central part of Scotland had a seroprevalence of 57.7%. This distribution disequilibrium may be due to the spread and survival of oocysts on pasture and lambing areas. A questionnaire accompanying sampling of flocks identified farms that used Toxovax^®, a commercial vaccine that protects sheep from abortion due to T. gondii infection. Only 24.7% of farmers used the vaccine and the vaccine did not significantly affect the within flock seroprevalence for T. gondii. The implications for food safety and human infection are discussed.  相似文献   

Developing vaccines to control protozoan parasites in ruminants: dead or alive?     

Innes EA  Bartley PM  Rocchi M  Benavidas-Silvan J  Burrells A  Hotchkiss E  Chianini F  Canton G  Katzer F 《Veterinary parasitology》2011,180(1-2):155-163

Protozoan parasites are among some of the most successful organisms worldwide, being able to live and multiply within a very wide range of hosts. The diseases caused by these parasites cause significant production losses in the livestock sector involving reproductive failure, impaired weight gain, contaminated meat, reduced milk yields and in severe cases, loss of the animal. In addition, some protozoan parasites affecting livestock such as Toxoplasma gondii and Cryptosporidium parvum may also be transmitted to humans where they can cause serious disease. Data derived from experimental models of infection in ruminant species enables the study of the interactions between parasite and host. How the parasite initiates infection, becomes established and multiplies within the host and the critical pathways that may lead to a disease outcome are all important to enable the rational design of appropriate intervention strategies. Once the parasites invade the hosts they induce both innate and adaptive immune responses and the induction and function of these immune responses are critical in determining the outcome of the infection. Vaccines offer green solutions to control disease as they are sustainable, reducing reliance on pharmacological drugs and pesticides. The use of vaccines has multiple benefits such as improving animal health and welfare by controlling animal infections and infestations; improving public health by controlling zoonoses and food borne pathogens in animals; solving problems associated with resistance to acaricides, antibiotics and anthelmintics; keeping animals and the environment free of chemical residues and maintaining biodiversity. All of these attributes should lead to improved sustainability of animal production and economic benefit. Using different protozoan parasitic diseases as examples this paper will discuss various approaches used to develop vaccines to protect against disease in livestock and discuss the relative merits of using live versus killed vaccine preparations. A range of different vaccination targets and strategies will be discussed to help protect against: acute disease, congenital infection and abortion, persistence of zoonotic pathogens in tissues of food animals and passive transfer of immunity to neonates.  相似文献   

What is your diagnosis? Serum biochemical data from Sprague‐Dawley rats in a toxicology study     

Irizarry Rovira AR  Halstead BW  Jolly RA  Baker TK 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2011,40(4):559-560

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USE OF DEXTROSE BY EXCISED TOMATO ROOTS     

Robbins WJ  Bartley MA 《Science (New York, N.Y.)》1937,86(2230):290-291

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A single-molecule study of RNA catalysis and folding     

Zhuang X  Bartley LE  Babcock HP  Russell R  Ha T  Herschlag D  Chu S 《Science (New York, N.Y.)》2000,288(5473):2048-2051

Using fluorescence microscopy, we studied the catalysis by and folding of individual Tetrahymena thermophila ribozyme molecules. The dye-labeled and surface-immobilized ribozymes used were shown to be functionally indistinguishable from the unmodified free ribozyme in solution. A reversible local folding step in which a duplex docks and undocks from the ribozyme core was observed directly in single-molecule time trajectories, allowing the determination of the rate constants and characterization of the transition state. A rarely populated docked state, not measurable by ensemble methods, was observed. In the overall folding process, intermediate folding states and multiple folding pathways were observed. In addition to observing previously established folding pathways, a pathway with an observed folding rate constant of 1 per second was discovered. These results establish single-molecule fluorescence as a powerful tool for examining RNA folding.  相似文献   

Nonstationary Phase of the Plio-Pleistocene Asian Monsoon     

SC Clemens  DW Murray  WL Prell 《Science (New York, N.Y.)》1996,274(5289):943-948

Paleoclimate records indicate that the strength of the Asian summer monsoon is sensitive to orbital forcing at the obliquity and precession periods (41,000 and 23,000 years, respectively) and the extent of Northern Hemisphere glaciation. Over the past 2.6 million years, the timing (phase) of strong monsoons has changed by approximately 83 degrees in the precession and approximately 124 degrees in the obliquity bands relative to the phase of maximum global ice volume (inferred from the marine oxygen isotope record). These results suggest that one or both of these systems is nonstationary relative to orbital forcing.  相似文献   

Suppression of ovine lymphocyte activation by Teladorsagia circumcincta larval excretory-secretory products     

Tom N McNeilly  Mara Rocchi  Yvonne Bartley  Jeremy K Brown  David Frew  Cassandra Longhi  Louise McLean  Jenni McIntyre  Alasdair J Nisbet  Sean Wattegedera  John F Huntley  Jacqueline B Matthews 《Veterinary research》2013,44(1):70

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