Fern Wilson

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Songbirds exhibit seasonal changes in the volumes of song control nuclei. Birds on long, spring-like days have larger nuclei than do birds on short, winter-like days. The mechanisms mediating volumetric changes have not been determined unequivocally, but testosterone (T) is probably involved. This study examined whether testicular factors are uniquely(More)
Thyroid hormone and long days interact to programme American tree sparrows (Spizella arborea) for seasonality (i.e. thyroid hormone-dependent photoperiodic gonadal growth, photorefractoriness, and postnuptial moult). This study explored in radiothyroidectomized (THX) males given thyroid hormone replacement therapy whether thyroid hormone acts within the(More)
Photoperiodic control of gonadotrophin secretion in male tree sparrows was studied by examining changes in plasma LH in castrated birds retained on short daylengths and in castrated birds transferred to long daylengths. Plasma LH concentrations were markedly higher in photostimulated birds than in non-photostimulated birds throughout the 25-day experiment,(More)
Photorefractoriness, a reversible state of unresponsiveness to daylengths of gonadostimulatory duration, terminates seasonal breeding in many photoperiodic species of birds. Whether the eyes are components of the mechanism that triggers photorefractoriness is an important, but heretofore unresolved, question. Although a role for extraocular photoreception(More)
We quantified the respiratory activity of 9 fetal lambs using computer-analysis of the diaphragmatic electromyogram (EMG) obtained during 2 h recording sessions interspersed over the last 13 days of gestation. The fetuses delivered unassisted at an average gestational age of 145 days (term = 147 days). During the last 2 h of labour the number of phasic EMG(More)
  • F E Wilson
  • 1990
The work reported here explored extraocular control of seasonal reproduction in a photoperiodic species. Photosensitive female tree sparrows (Spizella arborea) were subjected to bilateral or unilateral ocular enucleation or to sham operation and exposed to a photoregimen designed to stimulate luteinizing hormone (LH) secretion, to induce(More)
This Technical Design Report is dedicated to Tom Ypsilantis. Tom conceived the Ring Imaging Cherenkov detectors for particle identification in LHCb and he made an inestimable contribution to the LHCb RICH project. Tom would have wished to see these detectors in operation. He was totally dedicated to the project. He will be missed by the RICH group for his(More)
An experiment was performed to determine whether photorefractoriness in male tree sparrows is triggered by a testosterone-independent reduction in net photoperiodic drive or by a photoperiod-induced hypersensitivity of the hypothalamic-pituitary axis to testosterone negative feedback. Photosensitive male tree sparrows were transferred from 8 h light:16 h(More)
There is convincing evidence that euthyroid male American tree sparrows are already programmed for seasonal reproduction and postnuptial molt by Week 4 of photostimulation. To explore more precisely when, during early photostimulation, thyroid-dependent programming of seasonal events occurs, photosensitive male tree sparrows were radiothyroidectomized or(More)
Fifty infants who weighed 1250 g or less at birth were studied with serial real time cerebral ultrasound to evaluate the temporal relation of various perinatal factors to the onset and progression of periventricular haemorrhage (PVH). The significant antecedents of PVH were severe bruising at birth, low birthweight, short gestation, ratio of arterial oxygen(More)