DIMORPHISM IN THE DEVELOPMENTAL HISTORY OF THE SEX VEINS OF THE RABBIT     

Reagan FP  Tribe M 《Science (New York, N.Y.)》1928,68(1768):491-492

  相似文献   

Genetic and environmental factors affecting immunoglobulin G1 concentrations in ewe colostrum and lamb serum     

R P Gilbert  C T Gaskins  J K Hillers  C F Parker  T C McGuire 《Journal of animal science》1988,66(4):855-863

Presuckle colostral samples and lamb serum samples taken 36 h postpartum were assayed for immunoglobulin G1 (IgG1) concentration (mg/ml) using single radial immunodiffusion. Breeds sampled included Polypay (P), Rambouillet (R), Targhee (T), Columbia (C), Finnish Landrace (F) and Finn crosses (Fx). Sources of variation examined in IgG1 concentration in colostrum (dam trait) included dam's sire breed, dam's sire, age of ewe and number of lambs born. All sources of variation were statistically significant. Least-squares means of IgG1 levels for sire breed were 80, 64, 67, 64, 72 and 69 mg/ml for P, R, T, C, F and Fx breed groups, respectively. A fetal stimulus may exist to increase the mass of IgG1 in colostrum available for multiple births (61, 69 and 77 mg/ml for single, twin and triplet, respectively). Ewe age was a significant source of variation because of a high mean concentration of IgG1 in the yearling's colostrum (100 mg/ml), whereas only slight differences occurred between the other age groups (65 to 67 mg/ml), except for the 7-yr older group (53 mg/ml). Sources of variation examined in IgG1 concentration of lamb serum at 36 h postpartum (lamb trait) included lamb's sire breed, lamb's sire, age of dam, birth type and sex, with dam's colostral IgG1 concentration and day born as covariates. Sire within breed, birth type and the two covariates were significant. Least squares means for sire breed were 36, 32, 33, 32, 31 and 32 mg/ml of serum for P, R, T, C, F and Fx groups, respectively. Lamb serum IgG1 decreased as birth type increased. The heritability of IgG1, estimated by paternal half-sib analyses, was .19 +/- .12 for colostrum and .18 +/- .06 for lamb serum.  相似文献   

Evaluation of the dermal effects of cast padding in coaptation casts on dogs.     

S F Swaim  D M Vaughn  P J Spalding  K P Riddell  J A McGuire 《American journal of veterinary research》1992,53(7):1266-1272

Three configurations of cast padding and no cast padding were evaluated for their effects on skin in dogs. Padding was placed over bony prominences, between bony prominences, and over both areas for full-length padding under short-limb walking casts applied to 1 pelvic limb of Greyhounds. Evaluations were performed by pressure measurement over the calcaneal tuberosity, measurement of skin thromboxane B2 (TxB2) concentrations in skin over bony prominences, and measurement of plasma TxB2 concentrations. Pressure studies were performed to evaluate cutaneous pressures related to no cast padding and various configurations of cast padding. Concentrations of TxB2 in the skin were determined to evaluate the skin inflammatory effects of no padding and the padding configurations, and TxB2 concentrations in the plasma were analyzed to ascertain whether they could be used to predict impending dermal pressure lesions. Flexion of casted limbs revealed the greatest pressure over the calcaneal tuberosity with full-length cast padding. This was followed in decreasing order by no cast padding, padding over the prominences, and padding between the prominences. Compared with all other bony prominences and padding configurations, TxB2 skin concentrations were significantly higher over the calcaneal tuberosity when no padding was used and over the lateral base of metatarsal V when padding was placed between the prominences. Over the calcaneal tuberosity, this was attributed to the sharpness of the prominence and its potential for movement. This high TxB2 concentration corresponded to the high pressure found in the pressure studies. Over the lateral base of metatarsal V, the increase in TxB2 concentration was related to the mass of the prominence and the tendency for localized padding to settle around the area.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Microbial communities and their relevance for ecosystem models: Decomposition as a case study     

Krista L. McGuire  Kathleen K. Treseder 《Soil biology & biochemistry》2010,42(4):529-535

Soil microbial communities are so vastly diverse that complex interactions, which alter ecosystem functions, may occur among microbial species and functional groups. In this review, we explore the empirical evidence for situations when shifts in the community structure of microbes would elicit a change in ecosystem process rates, specifically decomposition, even when microbial biomass remains constant. In particular, we are interested in a subset of these scenarios in which knowledge of microbial community structure would improve model predictions for ecosystem functions. Results from microcosm and field studies indicate that microbial species diversity, functional group diversity, and community composition can all influence ecosystem process rates. The underlying mechanisms that may elicit changes in ecosystem functions from shifts in microbial community structure include evolutionary constraints on microbial trait adaptation, trait correlations, dispersal limitation, and species interactions. The extent of microbial diversity in soils is not known, so it is presently not possible to model all scenarios of microbial community structure shifts. However, by incorporating documented patterns in functional groups that are relevant for a particular ecosystem process and potential relationships between microbial phylogeny and function, the predictive power of process models will be significantly improved. The inclusion of this information into process models is critical for predicting and understanding how ecosystem functions may shift in response to global change.  相似文献   

Estimating stem respiration in trees by a mass balance approach that accounts for internal and external fluxes of CO2     

McGuire MA  Teskey RO 《Tree physiology》2004,24(5):571-578

The respiration rate of a tree stem has commonly been estimated from measurements of CO2 efflux to the atmosphere. These estimates assume that all CO2 efflux originates from respiration of local tissues and that all CO2 produced by local tissues escapes to the atmosphere through the bark. However, dissolved CO2 can be transported in the xylem stream, and CO2 concentration ([CO2]) in xylem can be up to three orders of magnitude greater than that of the atmosphere, suggesting that measurements of CO2 efflux do not account for all CO2 produced by respiration. Here, we propose a new mass balance approach for estimating the respiration rate of tree stems that accounts for both external and internal fluxes of CO2. We demonstrate this approach using measurements of CO2 efflux, sap flux and internal [CO(2)] to calculate the rate of CO2 production of a segment of stem tissue in situ. At different times of the day, CO2 produced by respiration of stem tissues followed different flux pathways. During daylight hours when sap was flowing, a large proportion of respired CO2 was carried away in the xylem stream, whereas at night, most respiratory CO2 escaped to the atmosphere through the bark. Our calculations showed errors in efflux-based estimates of respiration of up to 76% compared with estimates that include both internal and external fluxes.  相似文献   

Beef customer satisfaction: trained sensory panel ratings and Warner-Bratzler shear force values     

Lorenzen CL  Miller RK  Taylors JF  Neely TR  Tatum JD  Wise JW  Buyek MJ  Reagan JO  Savell JW 《Journal of animal science》2003,81(1):143-149

  相似文献   

Immunological reagents: catalysts for research progress.     

T C McGuire 《Equine veterinary journal》2001,33(7):628-629

  相似文献   

Effect of a high-fat diet on the performance response to porcine somatotropin (PST) in finishing pigs     

M J Azain  R W Seerley  J O Reagan  M K Anderson 《Journal of animal science》1991,69(1):153-161

One hundred sixty pigs were used in a 2 x 2 factorial design to compare the performance response to daily injection of porcine somatotropin (PST); (0 or 2 mg/d) in animals fed a 14% CP corn-soy diet (control, C) to those fed a diet with 10% added fat (F) and calorie:protein and lysine:protein ratios similar to that of the C diet. Treatments, assigned randomly to 20 pens (n = 5/treatment) of eight pigs each, were initiated at 90 kg body weight and continued for 28 d. Responses to PST and dietary fat were typical. These include improved gain and feed efficiency and decreased feed intake. The effects of dietary fat on intake and efficiency were accounted for largely by the difference in energy density of these diets. Across diets, PST treatment resulted in a 13% improvement in ADG (P less than .001), a 13% decrease in feed intake (P less than .0001) and a 22% improvement in efficiency (P less than .0001). Of particular interest were the additive (PST x diet interaction, P less than .2) effects of PST and dietary fat on gain in these animals. Pigs treated with PST that were fed the F diet had greater rates of gain than did PST-treated pigs fed the C diet (P less than .05). Treatment with PST increased ADG by 9% in pigs consuming the C diet vs 16% in pigs fed the F diet. Similarly, dietary fat resulted in 4 and 11% increases in ADG in pigs treated with 0 or 2 mg of PST/d.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Passive transfer of colostral immunoglobulins from ewe to lamb and its influence on neonatal lamb mortality   总被引：3，自引：0，他引：3  

M Sawyer  C H Willadsen  B I Osburn  T C McGuire 《Journal of the American Veterinary Medical Association》1977,171(12):1255-1259

The transfer of immunoglobulin G (IgG) and immunoglobulin M (IgM) from ewe to lamb was quantitated to determine the occurrence of failure in passive transfer. Concentrations of IgG and IgM in ewe serum did not correlate with those in the colostrum. Colostrum from all ewes contained abundant amounts of immunoglobulins when compared with serum values, with IgG being selectively concentrated over IgM. Absorption through the intestinal tract of the lamb appeared to be a nonselective process, lacking predilection for IgG and IgM. All lambs tested 24 hours after birth absorbed colostral immunoglobulins to some extent; however, 13 (14%) of 91 clinically normal lambs demonstrated some failure of passive transfer. In contrast, failure of passive transfer was found in 27 (46%) of 59 lambs dying of natural causes between 24 hours and 5 weeks of age. Evidence presented emphasizes the importance of absorption of adequate amounts of immunoglobulins to enable the newborn lamb to survive the first few weeks of life.  相似文献   

Spontaneous conjunctivitis and dacryoadenitis of mice   总被引：2，自引：0，他引：2  

J E Wagner  R G Garrison  D R Johnson  T J McGuire 《Journal of the American Veterinary Medical Association》1969,155(7):1211-1217

  相似文献