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Biomedical subjects

B Hayes

Publications and source records attributed to B Hayes.

63 records · Page 4Linked to original sources

The distribution of the effects of genes affecting quantitative traits in livestock.

Meta-analysis of information from quantitative trait loci (QTL) mapping experiments was used to derive distributions of the effects of genes affecting quantitative traits. The two limitations of such information, that QTL effects as reported include experimental error, and that mapping experiments can only detect QTL above a certain size, were accounted for. Data from pig and dairy mapping experiments were used. Gamma distributions of QTL effects were fitted with maximum likelihood. The derived distributions were moderately leptokurtic, consistent with many genes of small effect and few of large effect. Seventeen percent and 35% of the leading QTL explained 90% of the genetic variance for the dairy and pig distributions respectively. The number of segregating genes affecting a quantitative trait in dairy populations was predicted assuming genes affecting a quantitative trait were neutral with respect to fitness. Between 50 and 100 genes were predicted, depending on the effective population size assumed. As data for the analysis included no QTL of small effect, the ability to estimate the number of QTL of small effect must inevitably be weak. It may be that there are more QTL of small effect than predicted by our gamma distributions. Nevertheless, the distributions have important implications for QTL mapping experiments and Marker Assisted Selection (MAS). Powerful mapping experiments, able to detect QTL of 0.1sigma(p), will be required to detect enough QTL to explain 90% the genetic variance for a quantitative trait.

Animals↗

Ventilation and ventilators.

The history of ventilation is reviewed briefly and recent developments in techniques of ventilation are discussed. Operating features of ventilators have changed in the past few years, partly as the result of clinical progress; yet, technology appears to have outstripped the clinician's ability to harness it most effectively. Clinical discipline and training of medical staff in the use of ventilators could be improved. The future is promising if clinician and designer can work together closely. Ergonomics of ventilators and their controls and the provision of alarms need special attention. Microprocessors are likely to feature prominently in the next generation of designs.

Adult↗

Ventilation and ventilators--an update.

In the five years which have passed since the previous review, the literature has been concerned more with the ways in which ventilators may be applied to patients and the effects of differing patterns of ventilation than with the design philosophy of the ventilators themselves. This account should be read in conjunction with that of 1982 [1].

Adult↗

Testis unis, testis nullas: one witness is no witness. Criticisms of the use of oral history in nursing research.

In research, there is no perfection: no perfect method, no perfect sample, and no perfect data analyses tool. Coming to this understanding helps the researcher identify the inadequacies of their preferred method. This paper discusses the criticisms of the oral history method, drawing reference to its challenges and difficulties in relation to its use in nursing research. Oral history has the advantage over more traditional historical approaches in that the narrators can interpret events, personalities and relationships within the interview that are not accessible from written sources. The oral history interview may also provide a forum for unveiling documents and photographs, which might not have been otherwise discovered. Nonetheless, oral history, like most methodologies, is not flawless. This paper discusses the limitations of oral history and suggests ways in which a nurse can use oral history to provide an account of aspects of nursing history.

Autobiographies as Topic↗

A new approach to RIS/DR interconnection.

The article focuses on a new, standards-based approach for linking modalities to a radiology information system (RIS) in the radiology department. Computers have been used in radiology for quite some time-for the complex processing of algorithms used by CT and MR, for example. The advent of computed radiography (CR) and direct radiography (DR) has helped bring x-ray film into the world of computers. DR uses a technology similar to that in digital cameras to convert the intensity and location of the diagnostic image into digital form. Many radiology departments now store images on disks and read from computer monitors in a reading room. With its high-volume radiology department, the Cleveland Clinic Foundation (CCF) has been a long-time user of one particular RIS system. As the department moved to DR implementation, it required a means to automatically include patient demographic information with the image at the time of study acquisition, so this information would be associated with the image throughout its history. Using an approach developed by several companies in connection with CCF, technologists now use only two interfaces on one computer screen. Further, a technologist can close the study from the DR unit, allowing more time for patient care. The collaborative effort between CCF and the companies involved has resulted in an exciting standards-based approach to linking its RIS and DR systems.

Data Display↗

Determinants of influenza vaccination uptake among hospital healthcare workers.

Influenza vaccination of health care workers is recommended for their own protection and that of their patients. There is serendipitous protection for their contacts outside of work. Influenza vaccination uptake has been historically poor. A questionnaire study of healthcare staff at a tertiary referral hospital was carried out to evaluate knowledge of and attitudes to influenza and its vaccine. There was a 36% response rate to the questionnaire, but with reasonably proportionate representation of the various occupational groups. The mean acceptance of vaccine in respondents was 30%; however the vaccination rate for the hospital in 2003 was 16.2% indicating that non-vaccinees were under represented in the study sample.. Vaccine uptake increased with age. Occupationally, doctors, clerical and catering/household staff had higher than mean reported uptake of vaccine. Nurse respondents reported vaccine uptake of 22%. The role of these factors is examined in determining vaccine acceptance. A strong belief in the effectiveness of influenza vaccine was shown to be the strongest predictor of vaccine uptake with 66% of this group taking vaccine. A maximum score in an 8-question knowledge test was only associated with a 51% vaccine uptake. Implications for campaigns to improve uptake are discussed.

Adolescent↗

Naloxone, theophylline, bromocriptine, and obstructive sleep apnea. Negative results.

A total of 28 male patients objectively diagnosed with obstructive sleep apnea syndrome (OSAS) participated in specific drug trials involving naloxone (an opioid antagonist), theophylline and bromocriptine mesylate (a dopamine agonist). All subjects were between 15 and 40% overweight. The group median apnea-hypopnea (A + H) index was 58. None of the drugs had any significant beneficial effects on the number and duration of upper airway apneas and hypopneas or directly related oxygen desaturation. Theophylline increased the diaphragmatic activity during REM sleep-related mixed apnea but had no impact on upper airway apnea in the studied population.

Adult↗

Palatopharyngoplasty and obstructive sleep apnea syndrome.

Thirty-five patients diagnosed with obstructive sleep apnea syndrome (OSAS) underwent palatopharyngoplasty (PPP) after an objective evaluation. They were all monitored polygraphically after surgery. The group's postsurgical results were positive, with significant improvement in the apnea-hypopnea index (A + H index) and oxygen desaturation. However, patients with hypopharyngeal or mandibular problems or massive obesity had poor postsurgical results. As no subject has been followed for longer than two years, the long-term prognosis for this surgical approach is unknown.

Follow-Up Studies↗