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Biomedical subjects

M E Magnello

Publications and source records attributed to M E Magnello.

5 recordsLinked to original sources
PubMed1998

Karl Pearson's mathematization of inheritance: from ancestral heredity to Mendelian genetics (1895-1909).

Long-standing claims have been made for nearly the entire twentieth century that the biometrician, Karl Pearson, and colleague, W. F. R. Weldon, rejected Mendelism as a theory of inheritance. It is shown that at the end of the nineteenth century Pearson considered various theories of inheritance (including Francis Galton's law of ancestral heredity for characters underpinned by continuous variation), and by 1904 he 'accepted the fundamental idea of Mendel' as a theory of inheritance for discontinuous variation. Moreover, in 1909, he suggested a synthesis of biometry and Mendelism. Despite the many attempts made by a number of geneticists (including R. A. Fisher in 1936) to use Pearson's chi-square (X2, P) goodness-of-fit test on Mendel's data, which produced results that were 'too good to be true', Weldon reached the same conclusion in 1902, but his results were never acknowledged. The geneticist and arch-rival of the biometricians, Williams Bateson, was instead exceptionally critical of this work and interpreted this as Weldon's rejection of Mendelism. Whilst scholarship on Mendel, by historians of science in the last 18 years, has led to a balanced perspective of Mendel, it is suggested that a better balanced and more rounded view of the hereditarian-statistical work of Pearson, Weldon, and the biometricians is long overdue.

Biometry↗
PubMed1992

Diurnal changes in perceptions of energy and mood.

Data from five separate groups of volunteers show that diurnal variation in perceptions of physical and mental energy ('vigour') can be simply measured by the use of visual analogue scales. In all five groups, perceptions of vigour were significantly higher in the morning than at other times of day. In three groups where energy levels were measured six times daily the values achieved between 10.00 h and 12.00 h were significantly higher (P < 0.05) than those recorded on rising or retiring. Some evidence was also found for the existence of high energy levels in the evening (particularly among the undergraduates) and for an 'afternoon dip' in energy in about 20% of subjects. Higher levels of positive affect were also found in the morning and levels recorded between 10.00 h and 12.00 h were significantly greater than those on rising or retiring, (P < 0.01). However, no similar diurnal variation was observed for negative affect. The difference may be due to the fact that positive affect has a distinct 'biological' component contributing to perceptions of energy, whilst negative affect depends more on features in the individual's environment, which show no consistent diurnal pattern.

Adult↗
PubMed1992

Fluctuations in perceived energy and mood among patients with chronic fatigue syndrome.

Patients currently suffering or recently recovered from chronic fatigue syndrome (CFS) were compared with each other and with a group of well-matched controls in a study of diurnal variation in levels of perceived mental and physical energy and positive and negative affect. Patients who were currently ill showed diurnal variation in patterns of energy, with maximum levels being recorded between 10.00 h and 12.00 h which were significantly higher (P < 0.05) than energy levels recorded on rising or retiring. This pattern was similar to the controls but average energy levels at each time point were lower (P < 0.05) among the ill patients. Recovered patients showed the same pattern, with mean energy levels falling between those of the ill patients and controls. Similar diurnal patterns were found for perceptions of positive, though not negative affect. Correlations between physical and mental energy and between both of these energy variables and positive affect were high (r = 0.75 to 0.85) in both controls and CFS patients. However, correlations with negative affect were low (eg r = -0.10) and non-significant. Total scores on the Hospital Anxiety and Depression Scale (HAD) were significantly higher (P < 0.05) among patients who were still ill than those who had recovered. Scores on the HAD Depression (but not Anxiety) subscale were also significantly higher among those who were still ill (P < 0.01). These findings may be of value in facilitating programmes of cognitive-behavioural modification intended to aid the recovery of patients with CFS.

Adult↗
PubMed1990

Measuring vitality.

Subjective perceptions of mental and physical energy were measured by the use of visual analogue scales (VAS) over the course of a week in a group of normal volunteers. These variables were found to correlate, highly both with one another and with assessments of vigour and fatigue measured with a standard adjectival format. In addition, high correlations were found with a measure of positive affect. These five variables also displayed characteristic patterns of diurnal variation. Physical and mental energy, vigour and positive affect were highest in the morning, falling progressively and significantly over the day. In contrast, fatigue showed the opposite pattern. Extraversion showed positive correlations with physical and mental energy, vigour and positive affect, and negative correlations with fatigue and negative affect, most being significant (P less than 0.05). Conversely, neuroticism showed a negative correlation with the first four energy variables but was positively related to fatigue and negative affect, most correlations again being significant. Physical and mental energy, vigour and positive affect also showed a positive correlation (P less than 0.01) with a measure of happiness. It is concluded that VAS-derived ratings of physical and mental energy are reliable indicators of self-perceived vigour and fatigue. They are easy to record and show sufficient short-term stability to be used in more extensive studies both of well-being and of its physiological correlates.

Adult↗