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Biomedical subjects

D D Mann

Publications and source records attributed to D D Mann.

13 recordsLinked to original sources
PubMed2004

Ergonomic concerns with lightbar guidance displays.

This article reviews some ergonomic factors associated with agricultural guidance displays. Any technology or management decision that improves the efficiency of an agricultural operation can be considered an aspect of precision farming. Agricultural guidance displays are one such tool because they help to reduce guidance error (i.e., skipping and overlapping of implements within the field), which result in improper application of crop inputs at increased cost. Although each of the guidance displays currently available functions using a different principle, their key objective is to communicate useful guidance information to the operator of the agricultural machine. The case with which the operator obtains the required information depends on a number of ergonomic factors, such as color perceptibility, flash rate, attentional demand, display size, viewing distance, and height of placement of the display in the cab. Ergonomics can be defined as the application of knowledge to create a safe, comfortable, and effective work environment. Consequently, it is critical to consider ergonomics when designing guidance displays or when locating a display in the tractor cab. Without considering ergonomics, it is unlikely that the efficiency of the human-machine system can be optimized.

Agriculture↗
PubMed2003

Factors contributing to guidance performance when using a camera-based guidance aid.

A guidance aid is a device that provides guidance information to the driver rather than replacing the driver. With a camera-based guidance aid, the view seen by a forward-looking video camera is displayed on a monitor situated within the operator station of the vehicle. As the vehicle moves forward, images of the ground scroll vertically across the monitor. The rate at which the image scrolls, the image velocity, is related to the forward velocity of the vehicle, the placement of the camera (height and tilt angle), and the optical characteristics of the guidance camera. When tested with a tractor at forward velocities between 1.6 and 12.8 km/h, lateral error increased linearly as image velocity increased. Driver self-confidence decreased linearly as image velocity increased. Based on subjective feedback, drivers preferred a camera tilt angle of 20 degrees (over either 30 degrees or 40 degrees) because it yielded the greatest look-ahead distance. Statistically, a tilt angle of 30 degrees was best for a camera with a narrow field of view (narrow FOV, 20 degrees in the lateral direction). For a camera with a wide field of view (wide FOV, 39 degrees in the lateral direction), there was no statistical difference. For the narrow FOV camera, a camera height of 1.1 m yielded statistically smaller lateral errors than a camera height of 1.5 m. There was no statistical difference for the wide FOV camera. Overall, the lateral error was statistically smaller for the narrow FOV camera than for the wide FOV camera due to the difference in the lateral ratio for each camera, where the lateral ratio is the ratio of the lateral field of view of the camera to the fixed monitor width.

Accidents, Occupational↗
PubMed2000

Increasing osteopathic manipulative treatment skills and confidence through mastery learning.

Several recent studies document the declining use of osteopathic manipulative treatment (OMT) in clinical practice. In this article, the authors contend that developing new teaching materials based on the mastery learning approach can augment time-tested methods of teaching OMT and help to stop or reverse this decline. The Spencer technique for shoulder manipulation is used to demonstrate the development and evaluation of OMT mastery learning materials. These materials could be developed as part of a progressive teaching sequence requiring increasing diagnostic acumen, palpatory skill, and therapeutic subtlety. Such a program could be used throughout osteopathic medical training and for continuing medical education to increase skills and confidence in the use of OMT.

Clinical Competence↗
PubMed1997

An osteopathic prescription for medical education reform: Part 1. Curriculum and infrastructure.

Medical education has not kept pace with the evolving healthcare system. Criticism from industry and policy observers focuses on four major areas requiring reform: the curriculum, the fragmented educational infrastructure, the specialist-to-generalist mix, and the alienation from community and public health. The dominance of managed care organizations in the delivery and financing of healthcare is forcing a new set of physician competencies to the fore and changing projections of physician manpower and specialty needs. The authors address the four major criticisms from a uniquely osteopathic point-of-view. In this first of two articles, the authors describe the evolving osteopathic medical education model, and then employ a medical analogy to diagnose the causes of and propose treatments for curricular issues and infrastructure fragmentation. In the second article of the pair, they explore the causes of and propose strategies to address the generalist-to-specialist imbalance and the alienation of medicine from community and public health; the article also explores the role of technology in support of reform. In each article, the authors propose treatments to correct the problems in the osteopathic medical education model, and conclude that the profession is well-positioned to lead medical education reform.

Curriculum↗
PubMed1992

Synthesis and structure-activity relationships of 7-diazabicycloalkylquinolones, including danofloxacin, a new quinolone antibacterial agent for veterinary medicine.

A series of novel 6-fluoro-7-diazabicycloalkylquinolonecarboxylic acids substituted with various C8 (H, F, Cl, N) and N1 (ethyl, cyclopropyl, vinyl, 2-fluoroethyl, 4-fluorophenyl, 2,4-difluorophenyl) substituents, as well as, 9-fluoro-10-diazabicycloalkylpyridobenzoxazinecarboxylic acids, were prepared and evaluated for antibacterial activity against a range of important veterinary pathogenic bacteria. The diazabicycloalkyl side chains investigated at the 7-position (benzoxazine 10-position) include (1S,4S)-5-methyl-2,5-diazabicyclo[2.2.1]heptane (2), (1S,4S)-2,5-diazabicyclo[2.2.1]heptane (3), (1R,4R)-5-methyl-2,5-diazabicyclo[2.2.1]heptane (4), 8-methyl-3,8-diazabicyclo[3.2.1]octane (5), 9-methyl-3,9-diazabicyclo[4.2.1]nonane (6), 1,4-diazabicyclo[3.2.2]nonane (7), 1,4-diazabicyclo[3.3.1]nonane (8), and 9-methyl-3,9-diazabicyclo[3.3.1]nonane (9). Among these side chains, in vitro potency was not highly variable; other properties therefore proved more critical to the selection of possible development candidates. However, the relative potencies observed for several of these compounds in mouse, swine, and cattle infection models correlated well with those seen in vitro. A combination of the N1 cyclopropyl group and the C7 (1S,4S)-5-methyl-2,5-diazabicyclo[2.2.1]hept-2-yl appendage conferred the best overall antibacterial, physiochemical, and pharmacodynamic properties. Hence, danofloxacin (Advocin, 2c) (originally CP-76,136, 1-cyclopropyl-6-fluoro-7-[(1S,4S)-5-methyl-2,5-diazabicyclo[2.2.1] hept-2-yl]-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid) was selected as a candidate for development as a therapeutic antibacterial agent for veterinary medicine.

Actinobacillus Infections↗
PubMed1992

Pharmacokinetic study of danofloxacin in cattle and swine.

Pharmacokinetic values of a new quinolone antimicrobial, danofloxacin, were studied in cattle and swine. Plasma concentration was detected within 15 minutes after IM administration, peaked by 1 hour, and subsequently decreased, with half-life of 2.9 and 6.8 hours for cattle and swine, respectively. In swine, danofloxacin was absorbed, whether orally administered by gavage, in feed, or in drinking water. Danofloxacin concentrated in lung tissue at 4 to 7 times the plasma concentration. Lung tissue concentration exceeded the minimal inhibitory concentrations for im90portant respiratory tract pathogens for extended periods after administration of the drug by any of the routes studied. The major routes of excretion were in urine and bile.

Absorption↗
PubMed1984

Effect of subclinical levels of T-2 toxin on the bovine cellular immune system.

The effect of subclinical levels of mycotoxin T-2 on the cells of the bovine immune system was investigated in two in vivo experiments. In experiment 1, five calves were orally dosed with 0.3 mg/kg/day of T-2 toxin for 56 days and five calves were pair fed controls. The neutrophil function as measured by nitroblue tetrazolium reduction was reduced in the mycotoxin treated calves. The cutaneous reaction to intradermally injected phytohemagglutinin was reduced in the T-2 toxin treated calves. B-cell (SIg+) numbers increased slightly, but T-cell (PNA+) numbers were not affected during the experimental period. In the second experiment, six calves were given 0.5 mg/kg/day T-2 toxin orally for 28 days and six calves were pair fed controls. B-cell numbers and the response of a B-cell enriched fraction to phytohemagglutinin increased after toxin administration. T-cell numbers and the response of a T-cell enriched fraction and the whole mononuclear cell population to phytohemagglutinin was reduced only on day 19 posttoxin administration. The in vitro (T-2 toxin) exposure of the mononuclear cell population, B-cell enriched, or T-cell enriched fraction reduced their lymphoblastic response to mitogens. A 50% reduction was induced by as little as 1.4 ng/mL of T-2 toxin.

Animals↗
PubMed1983

Efficacy of aerosol, intranasal and intramuscular vaccination against selected bovine viral diseases.

An experiment was designed to compare the efficacy of an IM modified live vaccine, an IN temperature-sensitive vaccine, an IN modified live vaccine, and an aerosolized modified live vaccine (two concentrations) to stimulate specific serum antibody and protect calves from a known viral challenge. All vaccines except the IM vaccine contained IBR virus and PI3 virus. The IM vaccine and the IN vaccines provided excellent protection to an IBR challenge, but both concentrations of aerosolized vaccine provided only patial protection. The use of IN modified live vaccine resulted in IBR serum Ab titers in all the test calves (100%), while the IM preparation elicited a response in only 60% of test calves and the IN temperature sensitive vaccine resulted in serum Ab titers in 40% of test calves. The aerosolized vaccine induced IBR serum antibody titers in only 20% of the calves. The use of IN modified live and the aerosolized vaccine resulted in a greater immune response to the PI3 virus (60-80% sero-conversion) than did the temperature sensitive vaccine (20% sero-conversion).

Administration, Intranasal↗
PubMed1983

Effects of T-2 mycotoxin on bovine serum proteins.

Mycotoxin T-2 (0.5 mg/kg of body weight) was administered orally to mixed-breed beef calves. Serum protein fractions, immunoglobulin (Ig) G, IgM, and several complement protein concentrations were studied in control and toxin-treated calves. Total protein, albumin, and globulin concentrations all decreased in toxin-treated calves as compared with that in controls. Similarly, the concentrations of alpha-, beta 1-, and beta 2-globulin fractions were reduced in the toxin-treated calves more than those in controls. The IgG and IgM values were lower in toxin-treated calves than those in the controls. Complement proteins Bbov (of the alternate pathway) and the 3rd component of complement were lower in the toxin-treated calves. The fragment of Bbov activation, B gamma 2, was increased after toxin treatment, indicating that activation of the alternate complement pathway was responsible for at least some of the reduction of the 3rd component of complement.

Animals↗
PubMed1982

The effect of T-2 toxin on the bovine immune system: cellular factors.

The effect of T-2 toxin, a Fusarium metabolite, on the bovine cellular defense (immune) system was evaluated during high levels, chronic administration. The administration of T-2 toxin to calves at the rate of 0.6 mg/kg/day was associated with significant depression of lymphocyte responses to mitogens and significant decreases in chemotaxic migration of neutrophils.

Animals↗
PubMed1982

Effect of T-2 toxin on the bovine immune system: humoral factors.

The effect of a Fusarium metabolite, T-2 toxin, on the bovine humoral immune system was explored during high-level, chronic administration. T-2 toxin administered to calves for 43 days at the rate of 0.6 mg/kg per day was associated with alterations of serum protein fractions, immunoglobulin levels, and C3 levels. Significant reductions in the levels of alpha, beta 1, beta 2, and gamma globulins, but not albumin, occurred after T-2 toxin administration. Likewise, a decline in C3 and serum immunoglobulin levels were evident. The levels of immunoglobulin M and immunoglobulin A, but not immunoglobulin G, in toxin-treated calves were significantly lower than control levels.

Animals↗
PubMed1982

Evaluation of ketamine/xylazine anesthesia in the guinea pig: toxicological parameters.

The characteristics of ketamine/xylazine combinations were evaluated in guinea pigs. Particular attention was focused on the establishment of an LD50 and the development of a dose-response curve. Basic serum parameters (BUN, serum creatinine, and SGPT) were monitored for 5 days post-anesthesia. A large safety margin was indicated by an LD50 range of 361-373 mg/kg ketamine. The dose-response curve was linear between 40 and 120 mg/kg ketamine with constant 10 mg/kg xylazine. Although serum parameters were elevated 5 days postanesthesia they remained within normal limits for laboratory rodents.

Alanine Transaminase↗