Utilization of hormonal profiles as indicators of reproductive capacity in beef heifers

Two studies were conducted to examine the extent to which prepuberal hormone secretion can be used as an indicator of reproductive capacity in the beef heifer. The first involved prepuberal hormonal differences in 3 breeds of heifers (Angus, Crossbreds (SPxAN and HPxAN) and Polled Herefords). Basal and GnRH stimulated blood samples were obtained from Angus (AN, n=29), Crossbred (XB, n=14) and Polled Hereford (HP, n=14) at 6 ages (3, 5, 7, 9, 11 and 12 mo) . Basal values resulted from the avg of 3 hourly bleedings; GnRH values resulted from the avg of bleeding effected 1.5 & 3 hours after GnRH. RIA\u27s were conducted for luteinizing hormone (LH, ng/ml), follicle stimulating hormone (FSH, ng/ml), progesterone (P4, pg/ml), androstenedione (δ4A, pg/ml), testosterone (T, pg/ml) and estradiol (E2, pg/ml). Polled Herefords were distinctive in having the highest levels of the gonadotrophins, the least amount of E2, and a longer time to reach puberty. Crossbreds were significantly heavier at all ages and highest in their basal & GnRH stimulated secretion of T (at all ages) and δ4A (9, 11 & 12 mo) . Angus showed a higher secretion of basal & GnRH stimulated secretion of δ4A at 3, 5 & 7 mo. Ovulation (P4 \u3e 1 ng/ml) was observed in XB at 9 mo, AN at 11 mo and only 1 HP expressed high P4 values by 12 mo of age. Groups of heifers that ovulated at an early age had higher basal & GnRH simulated secretion of E2 & δ4A at 3 & 9 mo respectively. The second study was conducted over 2 years to examine the relationship between δ4A and gonadal steroids and their correlation with number of ovarian follicles. Ovaries were removed from 16 mo old AN heifers (n=20) for Year-1 and 14 mo old ANG (n=10) and XB heifers (n=8) for Year-2. Follicles were enumerated, classified and correlated with basal and GnRH stimulated steroid concentrations in serum. Heifers were bled at 3, 5, 7, 9, 11 & 12 mo of age. Heifers with the highest number of primary follicles had significantly higher δ4A at 9 & 11 mo and higher testosterone at 7 mo. Primary follicle numbers were positively correlated with secondary, growing, atretic and total vesicular follicles (r=.5). These results suggest: 1) that δ4A, T and E, could be used to predict early age at puberty and 2) that basal and GnRH stimulated δ4A and T either before or around the time of weaning could be used to predict primary follicle numbers. Utilizing these results, prepuberal androgens in conjunction with E2 could be used to predict the potential reproductive capacity of the beef heifer

Exercising the NON-VON Primary Processing Subsystem

The Primary Processing Subsystem of the NON-VON supercomputer potentially may comprise thousands of custom nMOS integrated circuits. It is vital that faulty components be detected and located. This paper provides a collection of algorithms to exercise the Primary Processing Subsystem so that the manifestation of latent faults may be observed

A Knowledge-Based Expert Systems Primer and Catalog

For more than 20 years, artificial intelligence techniques have been applied to the development of computer programs that solve difficult problems. Although several expert systems are well known, it is all too easy to circumscribe the field based on these few examples. The purpose of this paper is to present the fundamentals of the field (the Primer), and to give a broad overview via concise descriptions of many rule-based expert systems and knowledge engineering frameworks (the Catalog)

Execution or OPS5 Production Systems on a Massively Parallel Machine

In recent years, the development of expert systems implemented by rule-based production systems has emerged as one of the dominant paradigms in the field of artificial intelligence. While production systems offer important advantages in large-scale AI applications, their use in such applications is typically very costly in execution time. In this paper, we describe an algorithm for executing production systems expressed in the OPS5 language on a massively parallel multiple-SIMD machine called NON-VON, portions of which are currently under construction at Columbia University. The algorithm, a parallel adaptation of Forgy's Rete Match, has been implemented and tested on an instruction-level simulator. We present a detailed performance analysis, based on the implemented code, for the averaged characteristics of six production systems having an average of 910 inference rules each. The analysis predicts an execution rate of more than 850 production firings per second using hardware comparable in cost to a VAX 11/780. By way of comparison, a LISP-based OPS5 interpreter running on a VAX 11/780 typically fires 1 to 5 rules per second, while a Bliss-based interpreter executes 5 to 12 rules per second

NON-VON's Performance on Certain Database Benchmarks

In a paper by Hawthorn and DeWitt, the projected performance of several proposed database machines was examined for three relational database queries. The present paper investigates the performance of a massively parallel machine called NON-VON for the same queries under comparable assumptions. In the case of simple queries, a NON-VON machine of comparable size to those considered by Hawthorn and DeWitt is found to be somewhat faster than the fastest machines examined in their study; for a more complex database operation, NON-VON is shown to be five to ten times faster than the fastest of these machines

Chemokine transport across human vascular endothelial cells

Leukocyte migration across vascular endothelium is mediated by chemokines that are either synthesized by the endothelium or transferred across the endothelium from the tissue. The mechanism of transfer of two chemokines, CXCL10 (interferon gamma inducible protein [IP]-10) and CCL2 (macrophage chemotactic protein [MCP]-1), was compared across dermal and lung microvessel endothelium and saphenous vein endothelium. The rate of transfer depended on both the type of endothelium and the chemokine. The permeability coefficient (Pe) for CCL2 movement across saphenous vein was twice the value for dermal endothelium and four times that for lung endothelium. In contrast, the Pe value for CXCL10 was lower for saphenous vein endothelium than the other endothelia. The differences in transfer rate between endothelia was not related to variation in paracellular permeability using a paracellular tracer, inulin, and immunoelectron microscopy showed that CXCL10 was transferred from the basal membrane in a vesicular compartment, before distribution to the apical membrane. Although all three endothelia expressed high levels of the receptor for CXCL10 (CXCR3), the transfer was not readily saturable and did not appear to be receptor dependent. After 30 min, the chemokine started to be reinternalized from the apical membrane in clathrin-coated vesicles. The data suggest a model for chemokine transcytosis, with a separate pathway for clearance of the apical surface

Leukotriene antagonists as first-line or add-on asthma controller therapy

Most randomized trials of treatment for asthma study highly selected patients under idealized conditions. METHODS: We conducted two parallel, multicenter, pragmatic trials to evaluate the real-world effectiveness of a leukotriene-receptor antagonist (LTRA) as compared with either an inhaled glucocorticoid for first-line asthma-controller therapy or a long-acting beta(2)-agonist (LABA) as add-on therapy in patients already receiving inhaled glucocorticoid therapy. Eligible primary care patients 12 to 80 years of age had impaired asthma-related quality of life (Mini Asthma Quality of Life Questionnaire [MiniAQLQ] score =6) or inadequate asthma control (Asthma Control Questionnaire [ACQ] score =1). We randomly assigned patients to 2 years of open-label therapy, under the care of their usual physician, with LTRA (148 patients) or an inhaled glucocorticoid (158 patients) in the first-line controller therapy trial and LTRA (170 patients) or LABA (182 patients) added to an inhaled glucocorticoid in the add-on therapy trial. RESULTS: Mean MiniAQLQ scores increased by 0.8 to 1.0 point over a period of 2 years in both trials. At 2 months, differences in the MiniAQLQ scores between the two treatment groups met our definition of equivalence (95% confidence interval [CI] for an adjusted mean difference, -0.3 to 0.3). At 2 years, mean MiniAQLQ scores approached equivalence, with an adjusted mean difference between treatment groups of -0.11 (95% CI, -0.35 to 0.13) in the first-line controller therapy trial and of -0.11 (95% CI, -0.32 to 0.11) in the add-on therapy trial. Exacerbation rates and ACQ scores did not differ significantly between the two groups. CONCLUSIONS: Study results at 2 months suggest that LTRA was equivalent to an inhaled glucocorticoid as first-line controller therapy and to LABA as add-on therapy for diverse primary care patients. Equivalence was not proved at 2 years. The interpretation of results of pragmatic research may be limited by the crossover between treatment groups and lack of a placebo group