PubMed Health⌕ Search

Biomedical subjects

C V Thomas

Publications and source records attributed to C V Thomas.

14 recordsLinked to original sources
PubMed1996

A network simulation model of large herringbone and parallel milking parlors.

A network simulation model of herringbone and parallel milking parlors was built. Parlor performance was predicted based on the number of cows milked per hour and the amount of milk harvested per shift. Modeled parlors operated using a task-oriented milking routine. The simulation also modeled milking personnel, milking system vacuum pressure and pulsation ratio, and milk yield per cow per milking. The probability distributions of the model components that were used for validation were fitted from data collected from four dairies with the following parlors: double-16 herringbone, double-20 herringbone, double-35 parallel, and double-40 parallel. All fitted distributions were continuous, non-negative, and skewed to the right. The mean number of cows milked per hour (simulated and observed, respectively) was 1) double-16 herringbone, 164.8 and 164.6;2) double-20 herringbone, 207.6 and 206.6; 3) double-35 parallel, 319.2 and 320.2; and 4) double-40 parallel, 361.6 and 362.5. Mean milk yields harvested per shift were 1) double-16 herringbone, 9020 and 9030 kg; 2) double-20 herringbone, 14,800 and 14,746 kg; 3) double-35 parallel, 20,900 and 20,945 kg; and 4) double-40 parallel, 27,100 and 26,974 kg, for simulated and observed yields, respectively. Differences between simulated and observed means for either variable were not significant.

Animals↗
PubMed1996

Factors affecting the performance of simulated large herringbone and parallel milking parlors.

A simulation model of double-16 and double-20 herringbone and parallel milking parlors and double-32 and double-40 parallel milking parlors was used to examine the effects of size, design, operating characteristics of the milking system, management strategies, and milk yield on parlor performance. Analysis of factorial experiments indicated that smaller parlors were more efficient. Turns per hour and milk per stall per hour for double-16, -20, -32, and -40 parallel parlors were 5.87, 5.91, 5.21, and 5.00 turns/h and 56.19, 56.46, 49.66, and 47.94 kg/h, respectively. A wider pulsation ratio (60:40 to 70:30) increased performance measures about 4%, and increased vacuum pressure (46.6 to 50.8 kPa) increased performance measures > 6%. Parallel parlors outperformed herring-bones by nearly 8%. Abbreviated milking procedures resulted in a > 6% increase in performance measures over standard milking procedures. Performance response was significantly diminished when the amount of milking labor exceeded deficit amounts (20 to 32 units per milker) for abbreviated milking procedures or standard amounts (13.3 to 16 units per milker) for standard milking procedures. When milk yield increased, turns per hour decreased, but milk per stall per hour increased.

Animals↗
PubMed1994

Simulating individual cow milk yield for milking parlor simulation models.

A method of simulating individual cow milk yield per milking as a function of herd milk yield and month was formulated for milking parlor simulation models. Milk yield per milking was modeled for each month in three herd milk yield categories: 8165, 8845, and 9525 kg/yr of milk per cow. Actual individual cow DHIA test day milk weight data for three Florida dairy herds in each herd milk yield category and month were adjusted to the mean of their respective actual milk shipped per cow on test day then pooled and converted to a basis of three times per day milk yield per milking. After minor truncation, Weibull probability distributions fitted to these data sets adequately modeled milk yield per milking per cow. Analysis of simulation results for milk yield per milking per cow indicated no significant differences between actual and simulated means for any herd milk yield category or month. Simulations of monthly and yearly total herd milk yield for each herd indicated that fitted Weibull distributions also adequately modeled monthly and yearly herd milk yield characteristics and reflected seasonal herd milk yield patterns typical of Florida.

Animals↗
PubMed1993

Closure of large spina bifida defects: a simple technique based on anatomical details.

Much has been written about closure of large spina bifida defects. There is an increased demand to close these defects irrespective of the final outcome of the patient. Plastic surgeons may become involved in the closure of large defects. Perforator vessels of the back passing through the latissimus fascia can maintain viability of triangular island flaps. Therefore, such flaps can be used to close the large midline defects of spina bifida. This article reviews the literature and presents a simple technique based on anatomical properties of the region surrounding the defect.

Humans↗
PubMed1987

Thymic carcinoma and aplastic anemia: report of a previously undocumented association.

A case of thymic carcinoma documented after a 6-year history of aplastic anemia is reported. The anemia responded initially to steroids and antithymocyte globulin. The carcinoma may have arisen in a previous undetected thymoma; alternatively, an underlying abnormality, presumably immunologic, played a role in the development of the anemia and the thymic carcinoma.

Anemia, Aplastic↗
PubMed1987

Effects of colchicine on sulfated glycosaminoglycan production and cell detachment in pre-capillary pulmonary endothelial cells.

The effects of colchicine on the morphology, substrate adhesiveness, and production of glycosaminoglycan (GAG) macromolecules by cultured pre-capillary pulmonary endothelial cell were studied. Colchicine-treated cells demonstrated altered morphology and decreased substrate adhesiveness compared to untreated cells. In addition, [35S]sulfate incorporation into glycosaminoglycans was decreased 33% after treatment with colchicine. Spectrophotometric measurement of total cellular GAG revealed a similar GAG reduction in colchicine-treated cells. The composition of [35S]sulfate radiolabelled GAG was similar in cultures with and without colchicine, consisting of approximately 56% chondroitin sulfate and the remainder heparin/heparan sulfate. The results indicate that colchicine influences the biological behavior of pre-capillary endothelial cells, in part by altering the amount of glycosaminoglycan molecules produced.

Animals↗
PubMed1986

Primary Hodgkin's disease of the skull following a 3-year history of pseudotumor cerebri.

Hodgkin's disease involving contiguous areas of the skull, overlying soft tissue, and extending to the underlying epidural space, developed in a 29-year-old woman with a 3-year history of pseudotumor cerebri. The patient had been on varying doses of steroids since shortly after the development of headaches and papilledema in 1981. In 1984, following radiation therapy for Hodgkin's disease, the tumor and headaches resolved. Pseudotumor cerebri antedating Hodgkin's disease has not been previously reported. The pseudotumor cerebri may have been an early manifestation of Hodgkin's disease in an unusual location.

Adult↗
PubMed1985

Altered glycosaminoglycan production by HL-60 cells treated with 4-methylumbelliferyl-beta-D-xyloside.

Glycosaminoglycans, mainly chondroitin 4-sulfate, are located in the primary granules of human myeloid cells. These polyanionic carbohydrates are believed to play an important role in leukocyte maturation and function. To study the effect of altered chondroitin sulfate metabolism on human promyelocytic leukemia cells, we have treated HL-60 cells with 4-methylumbelliferyl-beta-D-xyloside. beta-D-Xylosides initiate the synthesis of free chondroitin sulfate chains. Cytochemical studies of treated cells demonstrated a marked increase in cytoplasmic granules stained with cationic dyes. This was confirmed by radiolabeled precursor incorporation studies that demonstrated a 344% increase in 35S-sulfate uptake into glycosaminoglycans associated with the cells and a 39% increase in incorporation into glycosaminoglycans released into the media. Chromatographic analyses of these glycosaminoglycans from treated cells demonstrated that the newly formed chondroitin sulfate chains were not attached to protein core and were of shorter length, but of greater charge density than chondroitin sulfate produced by control cells. Thus, beta-D-xyloside appears to alter the protein linkage, chain length, and sulfation of chondroitin sulfate produced by HL-60 cells, and these changes are morphologically evident. These biochemically altered cells may provide important information concerning the role of these macromolecules in myeloid development.

Cell Division↗
PubMed1982

Effects of premilking udder preparation on environmental bacterial contamination of milk.

Premilking udder preparations varied wetness and cleanliness of udders and teats at machine attachment. In Experiment I, in a prep stall with manual drying of teats only, udder surface drainage during milking increased standard plate counts compared to preparations with dryer udder surfaces at machine attachment. In Experiment 2, use of prep stall only and no udder and teat preparation had higher standard plate counts than preparations by prep stall with manual drying of udder and teats and by wet paper towels in wetting and cleaning and dry paper towels in drying teats. No preparation of udder and teats had higher standard plate count attributed to soiled teats at machine attachment. Udder surfaces should be dry, and teats should be clean and dry at machine attachment. Premilking udder preparations can affect milk quality as measured by milk bacterial count.

Animals↗
PubMed1980

Thin flaps.

Radically thinned flaps raised on a subdermal plane, or defatted to the subdermal plane, are described for skin cover for the hand and neck and thumb post construction. No further thinning is required and optimal functional and aesthetic results can be achieved.

Adult↗