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Biomedical subjects

J Bewley

Publications and source records attributed to J Bewley.

10 recordsLinked to original sources
PubMed2001

A comparison of free-stall barns used by modernized Wisconsin dairies.

A primary objective of the Wisconsin Dairy Modernization Survey was to compare features of free-stall barns available to dairy producers. This study used data from a large random sample of expanding dairy farms to determine whether the theoretical benefits of particular free-stall configurations bear out under on-farm conditions. Comparisons were made among herds using free-stall barns as their primary housing for new versus remodeled facilities, barn design, bedding used, feed-delivery design, manure removal strategies, animal restraint, maternity areas, overcrowding, and cooling methods. Producers who made the transition from tie-stall housing to free-stall housing were satisfied with this decision. New free-stall barns provided a more desirable environment for the herds than remodeled free-stall barns, although initial investments were higher. When new free-stall barns were compared, herds with four-row barns had higher production, lower somatic cell count, and higher stocking rates than herds with six-row barns. Respondents were more satisfied with four- and six-row barns than with two- and three-row barns. Respondents felt sand provided some advantages for cow comfort, while satisfaction with bedding cost and manure handling was higher with mattresses. Dairy Herd Improvement data showed no difference in milk production or somatic cell count for producers who chose sand or mattress-based free stalls. Respondents were more satisfied with the use of drive-through feeding than other feed-delivery designs. Most producers chose to use tractor scrapers to remove manure; however, producers who used automated systems were more satisfied with manure management. Few differences were observed when comparing self-locking head gates to palpation rails. Overcrowding did not have any adverse affect on production or user satisfaction with feed intake or cow comfort. Using supplemental cooling appeared to facilitate higher production.

Animal Feed↗
PubMed2001

Modeling milk production and labor efficiency in modernized Wisconsin dairy herds.

The 1999 Wisconsin Dairy Modernization Project was conducted to examine variation in milk production and labor efficiency among herds that had recently expanded. Data were obtained from a sample of Wisconsin herds that expanded between 1994 and 1998. Using rolling herd average milk production in 1998 as the dependent variable in the milk production model, milking frequency, bovine somatotropin use, sprinkler use, average linear somatic cell score, average age at first calving, average days dry, and rolling herd average milk production in 1994 predicted 69% of the variation in milk production. Milking three times daily, using bovine somatotropin, using sprinklers to cool cows, and decreasing linear somatic cell score, age at first calving, and days dry were associated with increased milk production. Each of these variables supports previous research from designed experiments with on-farm results. Variation in milk production is determined primarily by differences in management ability and management practices employed by the dairy producer. Using cows per full-time equivalent as the dependent variable in the labor efficiency model, acres per cow, number of people involved in the milking operation, milking system type, herd size, and interactions between milking system types and herd size predicted approximately 43% of the variation in labor efficiency. As expected, labor efficiency increased with larger herd sizes, fewer acres per cow, and fewer people involved in the milking process. Parallel milking parlors were associated with the highest cows per full-time equivalent followed by herringbone parlors, flat barns, and stall barns.

Animal Husbandry↗
PubMed2001

An overview of experiences of Wisconsin dairy farmers who modernized their operations.

Wisconsin dairy producers who modernized their operations between 1994 and 1998 had positive feelings about their expansion experiences, accompanied by increased production and improved profitability and quality of life. The average herd in this survey experienced increased production during the 5-yr period studied. Nearly all producers were satisfied with their expansion experience. The negative effect on milk production normally associated with expansion was minimal for most years and did not exist if all herds were summarized together. Managing labor appeared to be the most daunting challenge facing producers following expansion. Respondents who built all new facilities observed higher production, greater labor efficiency, and satisfaction with measures of profitability and quality of life than respondents who modified facilities or added no new facilities. As herd size increased, milk production, labor efficiency, and satisfaction with herd performance, profitability, and quality of life increased. Producers who built all new facilities spent less time on farm work, more time managing employees, and had less difficulty finding, training, supervising, and keeping farm employees than producers who modified facilities or added new facilities to existing operations. Larger herds were associated with an increased reliance on nonfamily labor. Managing labor appears to be an easier task for managers of larger herds. The most difficult challenges for producers who modernized their operations were with labor management, financing, and loan procurement, construction and cost overruns, and feet and leg health. Difficulties with expansion differed little between expansion types (same type, some new, or all new facilities) or herd sizes.

Animal Husbandry↗
PubMed2001

Producer satisfaction, efficiency, and investment cost factors of different milking systems.

A modernization survey was used to determine producer satisfaction, efficiency, and investment cost measures of different milking systems. The 301 producers included in this study expanded herd size by at least 50% for smaller herds (60 to 100 cows), or 40% for larger herds, (>100 cows) between 1994 and 1998. The milking systems analyzed and compared were stall barn with pipeline, flat barn parlor walk through and back-out, and herringbone or parallel parlor in old barn or new building. Investment costs per cow were higher for pit parlor in new building, $979. Parallel parlors had a higher cost per milking unit, $13,201, and cost per cow, $860, than herringbone, $8944 and $582, respectively. Herringbone parlors were used more hours per day, 10.75, than parallel parlors, 8.84, of similar size. Pit parlors in new buildings were more labor efficient, as measured by cows per worker hour, than stall barns with pipeline or flat parlor or pit parlors in old barns. Herringbone and parallel parlor in new building were similar for cows per hour (82 and 83) and cows per worker hour (41 and 43). Parallel or herringbone parlors in old barns had fewer cows per hour (63 and 58) than parallel or herringbone parlors in new buildings. Survey respondents showed greater satisfaction for time spent milking, physical comfort of milker, and milk quality for parlor types over stall barn with pipeline. Safety of operator satisfaction was higher for pit parlors than flat parlors or stall barn. No difference in satisfaction was observed between parallel and herringbone parlors.

Animals↗
PubMed1999

Gastric pressure during emergency caesarean section under general anaesthesia.

Gastric pressure and volume were measured in 20 pregnant women during emergency Caesarean section under general anaesthesia with neuromuscular block. Mean gastric pressure was 11 (range 4-19) mm Hg and we can predict that 99% of women undergoing emergency Caesarean section with neuromuscular block are likely to have gastric pressures of less than 25 mm Hg (mean + 3 SD). This has implications for the amount of cricoid pressure required during induction of anaesthesia. Gastric pressure increased during delivery to 19 mm Hg and fundal pressure caused a gastric pressure of 65 mm Hg in one woman. Gastric pressure decreased significantly after delivery (P < 0.001) to 8 mm Hg. Although we measured large gastric volumes (mean 112 (range 20-350) ml), there was no correlation between gastric volume and gastric pressure.

Adult↗
PubMed1998

The antiproliferative and cell cycle effects of 5,6,7, 8-tetrahydro-N5,N10-carbonylfolic acid, an inhibitor of methylenetetrahydrofolate dehydrogenase, are potentiated by hypoxanthine.

5,6,7,8-Tetrahydro-N5,N10-carbonylfolic acid (LY354899) has been demonstrated to inhibit the dehydrogenase activity of C1-tetrahydrofolate synthase. This compound was only moderately antiproliferative toward CCRF-CEM lymphocytic leukemia cells in culture, but induced apoptosis after long incubation times. Slightly greater potency was observed in CEM cells adapted to grow in low folate media. Cell cycle alterations induced by LY354899 were unique relative to antifolates that inhibit either the purine or thymidine de novo biosynthetic pathways. Based on the observed changes in DNA content, we hypothesized that inhibition of the dehydrogenase resulted in two temporally distinct events: the first was a purineless-like effect and the second was a thymineless-like effect that resulted in apoptosis. To test this hypothesis, we combined LY354899 with the purine salvage metabolite, hypoxanthine. This combination resulted in an earlier and more dramatic apoptotic response, indicating that the thymineless effect had been potentiated. Biochemical analysis of ribo- and deoxyribonucleoside triphosphates confirmed that inhibition of the dehydrogenase activity initially resulted in decreased pools of deoxypurines and deoxypyrimidines, followed 16 hr later by an increase in deoxyadenosine triphosphate (dATP) and a further decrease in deoxythymidine triphosphate (dTTP). These studies demonstrate that the inhibition of the dehydrogenase activity of C1-tetrahydrofolate synthase may represent a viable target for the development of novel antifolates. The results are discussed in terms of deoxypurine and deoxypyrimidine biosynthesis.

Antineoplastic Agents↗
PubMed1995

Respiratory arrest outside hospital.

Of 954 attempted resuscitations outside hospital performed by ambulance personnel, 48 patients (5%) had primary respiratory arrest. Comparing this group with those manifesting cardiorespiratory arrest, patients with primary respiratory arrest were significantly more likely to be female (25 of 48 vs 269 of 906-P < 0.005), were more likely to have a non-cardiac cause (67% vs. 22%-P < 0.00001) and more likely to have witnessed arrest. Of all arrests witnessed by ambulance crew, 35% were respiratory arrests. Basic and advanced life-support was delivered sooner. Outcome was significantly better, with 19 patients (40%) being discharged compared to only 49 patients (5.1%) discharged in cases of cardiorespiratory arrest (p < 0.00001). Considering that many respiratory arrests were witnessed by ambulance crew, the type of crew (EMT or paramedic) made no difference to outcome. Our findings suggest that patients manifesting respiratory arrest outside hospital are a heterogeneous group who have a relatively good prognosis regardless of the type of ambulance crew that attends.

Age Distribution↗
PubMed1989

Kinin receptors on epithelial cells and smooth muscle of the trachea.

Kallidin and bradykinin produce a biphasic response, contraction followed by relaxation on the isolated guinea-pig tracheal muscle. Two population of receptors appear to regulate the action of kinins on the trachea. Receptors on the epithelium seem to release chemical mediators that control the relaxation response. The question whether similar or different receptors modulate contraction of the smooth muscle may be answered by the use of appropriate antagonists. The occurrence of kinins in bronchial lavage of patients with asthma raises the question of the source of tissue kallikrein involved in the formation of kallidin. We have identified immunoreactive tissue kallikrein in the submucous glands of the trachea.

Acetylcholine↗