Search PubMed⌕ Search

Biomedical subjects

M Stevenson

Publications and source records attributed to M Stevenson.

197 records · Page 11Linked to original sources
PubMed1977

Polygraphic studies of kitten development: sleep state patterns.

The sequence of developmental changes in sleep pattern organization was derived from 12-hr recordings in 10-, 20 and 40-day-old kittens. Each characteristic of sleep patterning exhibited a distinct maturational sequence. Earlier changes (10-20 days) included quiet sleep (QS) increments and somatic activity decrements; later changes (20-40 days) included emergence of EEG slow waves and spindles, decrements in active sleep (AS), and diminution of QS respiratory variability. Changes in the lengths of state epochs and the types of state transitions spanned the period studied. We suggest that the differential development of the characteristics of sleep patterns reflects differential maturation of distinct nervous system elements.

Age Factors↗
PubMed1976

Gastric inhibitory polypeptide (GIP). Intestinal distribution and stimulation by amino acids and medium-chain triglycerides.

Radioimmunoassayable gastric inhibitory polypeptide was measured in extracts of canine antrum, duodenum, jejunum, and ileum. The highest GIP concentrations were found in the duodenum (347 +/- 53 ng/g) and jejunum (300 +/- 68 ng/g). An immunochemical similarity was demonstrable between porcine GIP and canine GIP. Dogs prepared with Mann Bollman fistulae were given an amino acid (AA) mixture or medium-chain triglycerides (MTC) by intraduodenal perfusion. With AA, a peak mean serum concentration of 672 +/- 106 pg/ml was reached 15 min after starting the perfusion. MCT resulted in a peak mean serum GIP concentration of 504 +/- 55 pg/ml 30 min after beginning the perfusion. When compared to results previously reported from this laboratory, AA and MCT are not as potent as corn oil (long-chain triglyceride) or glucose in stimulating GIP release. We conclude: (1) Immunoassayable GIP concentrations are highest in the canine proximal small intestine. (2) AA and MCT are weak stimulants of GIP release in the dog.

Amino Acids↗
PubMed1975

Assessment of clinical competence using objective structured examination.

To avoid many of the disadvantages of the traditional clinical examination we have introduced the structured clinical examination. In this students rotate round a series of stations in the hospital ward. At one station they are asked to carry out a procedure, such as take a history, undertake one aspect of physical examination, or interpret laboratory investigations in the light of a patient's problem, and at the next station they have to answer questions on the findings at the previous station and their interpretation. As they cannot go back to check on omissions multiple-choice questions have a minimal cueing effect. The students may be observed and scored at some stations by examiners using a check list. In the structured clinical examination the variables and complexity of the examination are more easily controlled, its aims can be more clearly defined, and more of the student's knowledge can be tested. The examination is more objective and a marking strategy can be decided in advance. The examination results in improved feed-back to students and staff.

Clinical Laboratory Techniques↗
PubMed1975

Tape/slide programmes for independent study. Methods of presentation to students.

Programmed audio tape/slide presentations have been presented to students by a variety of methods, (a) individual or pairs of students using automatic equipment in study booths; (b) students using simple portable equipment in or out of the learning centre; (c) groups of students in which discussion was encouraged; and (d) groups of students in which the student answered the questions individually without discussion. Each method has its advantages and disadvantages. With the exception of the groups without discussion, all were popular and chosen by a significant number of students as the method of choice. Automatic equipment in study booths was the most popular single method though the use of simple portable equipment had particular advantages. The majority of students prefer to have access to more than one method of presentation and attempts should be made to provide the learner with a variety of opportunities. The use of individual learning materials by groups of students should be further explored.

Attitude↗
PubMed1971

Isolation and characterization of temperature-sensitive mutants of vesicular stomatitis virus, New Jersey serotype.

Forty-eight temperature-sensitive (ts) mutants have been isolated from a wild-type strain of the New Jersey serotype of vesicular stomatitis virus (VSV) after exposure to the base analogue mutagen 5-fluorouracil. Of these mutants, 47 have been classified into 6 nonoverlapping complementation groups containing 21, 17, 4, 3, 2, and 1 mutant, respectively (1 mutant remaining unallocated). The ribonucleic acid (RNA) phenotype of 23 of these mutants has been established. Four of the six groups contain one or more mutants unable to synthesize detectable amounts of viral RNA under restrictive conditions (39 C). No complementation was observed in mixed infection with ts mutants from the five established complementation groups of the Indiana serotype of VSV.

Animals↗
PubMedDate not supplied

Where do patients with cancer die in Belfast?

BACKGROUND: Most patients with cancer prefer to die at home but the majority die in institutions. AIM: To determine place of death for patients with cancer in Belfast, to examine changes over time and identify factors associated with place of death. METHODS: A survey of deaths registered in Belfast over a six-month period for 1977, 1987 and 1997 identified patients dying from cancer. Epidemiological data included age, gender, malignancy, social class, marital status, area of residence and place of death. RESULTS: Home deaths fell from 35% in 1977 to 28% in 1997. Hospital deaths fell from 50% in 1977 to 40% in 1987 rising to 42% in 1997. Hospice deaths rose from 13% in 1977 to 25% in 1987 falling to 23% in 1997. There was an association between place of death and age, marital status, type of cancer and area of residence, but not with social class or gender. CONCLUSION: The majority of people fail to achieve a home death. Resources need to be targeted to those most at risk of an institutional death; females, the elderly, the unmarried, those with haematological malignancies and residents of South Belfast.

Aged↗
PubMedDate not supplied

Classification of the myoelectric signal using time-frequency based representations.

An accurate and computationally efficient means of classifying surface myoelectric signal patterns has been the subject of considerable research effort in recent years. Effective feature extraction is crucial to reliable classification and, in the quest to improve the accuracy of transient myoelectric signal pattern classification, an ensemble of time-frequency based representations are proposed. It is shown that feature sets based upon the short-time Fourier transform, the wavelet transform, and the wavelet packet transform provide an effective representation for classification, provided that they are subject to an appropriate form of dimensionality reduction.

Action Potentials↗