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21.
Serum immunoglobulin profiles of dairy cows chronically treated with recombinant bovine somatotropin
J L Burton B W McBride B W Kennedy J H Burton T H Elsasser B Woodward 《Journal of dairy science》1991,74(5):1589-1598
The objective of this study was to determine the effects of exogenous somatotropin on blood profiles of the major bovine Ig isotypes. Holsteins were treated with either 0, 10.3, or 20.6 mg recombinant bST/d. Subcutaneous injections were started between wk 4 and 5 of lactation and continued for 266 d. Blood samples were collected by coccygeal venipuncture throughout lactation for serum IgG, G1, G2, A, and M concentration determination. Cows treated with 10.3 mg of bST/d exhibited modest increases in mean blood concentrations of IgG (12.4%) and IgG2 (18.4%) relative to the other groups of cows. In addition, treated cows had 10.1% higher average concentration of IgA than controls. Somatotropin did not influence average lactational concentrations of IgG1 or IgM, although the group receiving 10.3 mg/d had higher late lactation concentrations of IgG1 than did the other two groups. However, treatment mean isotype concentrations were always within normal ranges, except for IgG2 from the 10.3 mg/d group, which were higher. The practical significance of elevated serum Ig concentrations observed in the present study is not known. However, the present data do show that bST administered at doses that increased milk yield had no apparent detrimental effect on humoral immunity as measured by blood concentrations of Ig. 相似文献
22.
DL McKinzie KL Nowak L Yorger WJ McBride JM Murphy L Lumeng TK Li 《Canadian Metallurgical Quarterly》1998,22(5):1170-1176
The alcohol-deprivation effect (ADE) was examined under 4-hr operant and 24-hr free-choice alcohol access in the alcohol-preferring (P) rat after deprivation intervals from 2 to 4 weeks. Results indicated that adult male P rats responding for 6 weeks on a concurrent FR-5/FR-1 schedule of reinforcement for alcohol and water, respectively, and then deprived of alcohol for 2 weeks, demonstrated a 40% increase in alcohol responding during the first 60 min of alcohol reinstatement. The alcohol deprivation effect was temporary, however, as responding did not differ from baseline levels on the second day of reinstatement. In a second experiment, weanling male and female P rats received 7 weeks of continuous access to alcohol, beginning at 21 days of age, and were then deprived of alcohol for 4 weeks. On the first day of alcohol reinstatement, P rats exhibited a 40% to 45% increase from baseline alcohol drinking levels, with alcohol intake returning to baseline levels by the 3rd day of reinstatement. Although alcohol intake was higher in females than in males when adjustment was made for body weight, there were no gender differences in the magnitude of the alcohol deprivation effect. Taken together, these results indicate that the ADE is a long-lasting phenomenon that occurs under both operant and continuous access conditions in the P rat, and thus these rats may be useful models for the study of factors involved in relapse of alcohol drinking. 相似文献
23.
Previously, we have described a template-assisted combinatorial peptide library based on the anti-tryptic reactive site loop of a Bowman-Birk inhibitor (BBI). Sequences that displayed inhibitory activity re-directed towards chymotrypsin were found to have a consensus binding motif, with their most striking feature being that exclusively threonine was found at the P2 position. The present study investigates the reason for this surprising specificity by maintaining the binding motif but systematically varying the P2 residue. From analysis of 26 variants, it is found that the requirements for inhibitory activity at P2 are finely tuned, and in agreement with the library work, threonine at P2 provides optimal inhibition. In addition, peptides with threonine at P2 are significantly less susceptible to hydrolysis. Examination of all available BBI sequences shows that threonine is very highly conserved at P2, which implies that the functional requirement extends to the full-length BBI protein. Our results are consistent with a dual requirement for hydrophobic recognition within the S2 pocket and maintenance of an inhibitory conformation via hydrogen bonding within the reactive-site loop. As the isolated peptide loop reproduces the active region of full-length BBI, these results explain why threonine is well conserved at P2 in this class of inhibitor. Furthermore, they illustrate that proteinase inhibitor specificity can have characteristics that are not easily predicted from information on the substrate preferences of a proteinase. 相似文献
24.
Other Index
Contents by Keyword 相似文献25.
Keunen JE Plaizier JC Kyriazakis I Duffield TF Widowski TM Lindinger MI McBride BW 《Journal of dairy science》2003,86(3):954-957
The effect of inducing subacute ruminal acidosis (SARA) on the free-choice intake of sodium bicarbonate (SB) was investigated in four midlactation Holstein cows in a switchover experiment with four 1-wk periods. The SARA was induced by replacing 25% of the ad libitum intake of total mixed ration (TMR) with pellets containing 50% ground wheat and 50% ground barley and restricting access to TMR from 0700 to 1700 h. Control consisted of feeding TMR ad libitum. Powdered SB was provided for ad libitum consumption. Rumen pH was measured continuously using indwelling pH probes. Induction of SARA reduced (P < 0.05) the average daily rumen pH from 6.08 to 5.87, increased (P < 0.05) the average duration of rumen pH below 6 from 547 min x d(-1) to 916 min x d(-1), and increased (P < 0.05) the average duration of rumen pH below 5.6 from 132 min x d(-1) to 397 min x d(-1) (P < 0.05) but did not significantly affect SB intake. Average intake of SB was 26.8 g x d(-1) during SARA and 34.5 g x d(-1) during control. These low SB intakes must not have substantially affected rumen pH. Sodium bicarbonate intake differed significantly (P < 0.05) between cows. These data indicate that cows did not select SB in order to attenuate SARA. 相似文献
26.
Ta-Hsuan Lin Menezes A.S. Andros F. McBride D.G. Lu S. Sammakia B. 《Electronics Packaging Manufacturing, IEEE Transactions on》2007,30(3):206-212
This paper addresses a new flip chip interconnection technology, flexible flip chip connection (F2C2) technology, for attaching silicon chips to a chip carrier using flexible copper wires. F2C2 is a novel approach to create area array flip chip interconnections using a matrix block of wires encapsulated with a heat-resistant, dissolvable substance. A slice from the wire matrix ingot is first attached to the chip using solder. The other end of the slice is then matched and soldered to the footprint of a substrate. Finally, the encapsulating, dissolvable substance is removed from the body of the slice, leaving the chip attached to the carrier by the inter- disposed, flexible copper wires. The compliant copper wire interconnections can accommodate the coefficient of thermal expansion (CTE) mismatch problem between die and substrate, thus eliminating the need for underfill. 相似文献
27.
The parcel delivery industry (PDI) is a very labor intensive industry, from the drivers of the pickup and delivery vans, to the unloaders, sorters, and loaders in the transshipment terminals. The labor efficiency is a key performance measure in the PDI. In this study, the focus is on developing a framework for improving labor efficiencies in a parcel transshipment terminal. The objective is to minimize the time required to transfer parcels from inbound trailers to outbound trailers. This paper is an exploratory study to developing a framework for a solution approach to solve large-scale parcel hub scheduling problems (PHSP). A binary integer programming (BIP) model is proposed along with a branch and bound (BaB) algorithm with lower and upper bounds. The computational study shows that the BaB algorithm is able to generate solutions for small-size problems. The proposed BIP model sets the ground work for developing solution approaches to much larger size problems. 相似文献
28.
An analysis of the relationship between ethology and comparative psychology is presented by an ethologist whose background was in agriculture, animal breeding, and evolutionary genetics. The view is presented that today, comparative psychology is largely an American name for the ethological work taking place in psychology departments throughout the world. Generally, those studying animal behavior or human ethology fill an important niche in psychology departments, providing the biological, particularly the evolutionary, complement to other fields of psychology. This role is functional, rather than having a theoretical foundation different from ethology. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
29.
The importance of generalizability for anomaly detection 总被引:1,自引:1,他引:0
In security-related areas there is concern over novel “zero-day” attacks that penetrate system defenses and wreak havoc. The
best methods for countering these threats are recognizing “nonself” as in an Artificial Immune System or recognizing “self”
through clustering. For either case, the concern remains that something that appears similar to self could be missed. Given
this situation, one could incorrectly assume that a preference for a tighter fit to self over generalizability is important
for false positive reduction in this type of learning problem. This article confirms that in anomaly detection as in other
forms of classification a tight fit, although important, does not supersede model generality. This is shown using three systems
each with a different geometric bias in the decision space. The first two use spherical and ellipsoid clusters with a k-means algorithm modified to work on the one-class/blind classification problem. The third is based on wrapping the self points
with a multidimensional convex hull (polytope) algorithm capable of learning disjunctive concepts via a thresholding constant.
All three of these algorithms are tested using the Voting dataset from the UCI Machine Learning Repository, the MIT Lincoln
Labs intrusion detection dataset, and the lossy-compressed steganalysis domain.
Gilbert “Bert” Peterson is an Assistant Professor of Computer Engineering at the Air Force Institute of Technology. Dr. Peterson received a BS degree
in Architecture, and an M.S. and Ph.D. in Computer Science at the University of Texas at Arlington. He teaches and conducts
research in digital forensics and artificial intelligence.
Brent McBride is a Communications and Information Systems officer in the United States Air Force. He received a B.S. in Computer Science
from Brigham Young University and an M.S. in Computer Science from the Air Force Institute of Technology. He currently serves
as Senior Software Engineer at the Air Force Wargaming Institute. 相似文献
30.
135 male and 256 female undergraduates completed the Self-Rating Depression Scale, Beck Depression Inventory, Depression Adjective Check Lists, State-Trait Anxiety Inventory, Taylor Manifest Anxiety Scale, S-R Inventory of Anxiousness, Marlowe-Crowne Social Desirability Scale, and Edwards Social Desirability Scale. Pearson correlation coefficients indicated strong relationships between measures of depression and between measures of anxiety. However, pairs of anxiety and depression measures correlated almost as strongly. All depression and anxiety measures were significantly associated with the Edwards Social Desirability Scale. Findings question the use of a self-report measure of depression to select "depressed" Ss among college students. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献