Biomedical subjects
Matthew Richardson
Publications and source records attributed to Matthew Richardson.
Phonetic processing areas revealed by sinewave speech and acoustically similar non-speech.
The neural substrates underlying speech perception are still not well understood. Previously, we found dissociation of speech and nonspeech processing at the earliest cortical level (AI), using speech and nonspeech complexity dimensions. Acoustic differences between speech and nonspeech stimuli in imaging studies, however, confound the search for linguistic-phonetic regions. Presently, we used sinewave speech (SWsp) and nonspeech (SWnon), which replace speech formants with sinewave tones, in order to match acoustic spectral and temporal complexity while contrasting phonetics. Chord progressions (CP) were used to remove the effects of auditory coherence and object processing. Twelve normal RH volunteers were scanned with fMRI while listening to SWsp, SWnon, CP, and a baseline condition arranged in blocks. Only two brain regions, in bilateral superior temporal sulcus, extending more posteriorly on the left, were found to prefer the SWsp condition after accounting for acoustic modulation and coherence effects. Two regions responded preferentially to the more frequency-modulated stimuli, including one that overlapped the right temporal phonetic area and another in the left angular gyrus far from the phonetic area. These findings are proposed to form the basis for the two subtypes of auditory word deafness. Several brain regions, including auditory and non-auditory areas, preferred the coherent auditory stimuli and are likely involved in auditory object recognition. The design of the current study allowed for separation of acoustic spectrotemporal, object recognition, and phonetic effects resulting in distinct and overlapping components.
Monitoring the widening participation initiative for access to medical school: are present measures sufficient?
CONTEXT: Widening access to higher education is a political priority. Social trends among medical school applicants are presently monitored using information on parental occupation. However, not all students now provide this information on their university application forms. OBJECTIVES: To compare the demographic characteristics of applicants who do and do not provide information about parental occupation, and to consider the utility of an alternative measure based on area of residence (Townsend score). METHODS: We surveyed the application forms of all individuals domiciled in England who made applications to English medical schools in 1996-2003. RESULTS: During 1996-2003, the proportion of applicants who did not declare parental occupation rose from 4.6% to 18.2%. Younger applicants were more likely to state that their parents were employed in professional/managerial occupations than mature applicants. White applicants were more likely to be from professional/managerial classes (72%) than were Black (60%) or Asian (60%) applicants. Although an association between socioeconomic class based on parental occupation and Townsend score was noted, this masked substantial variation between demographic groups. Applicants who did not disclose their parents' occupations were more likely to be non-White and to live in deprived areas. However, White applicants who did not state parental occupation were equally distributed by Townsend score. CONCLUSIONS: The sole use of parental occupation or area-based measures to monitor widening participation programmes requires caution given the proportion of applicants who do not provide this information and the age and ethnic group differences noted.
Differentiation of speech and nonspeech processing within primary auditory cortex.
Primary auditory cortex (PAC), located in Heschl's gyrus (HG), is the earliest cortical level at which sounds are processed. Standard theories of speech perception assume that signal components are given a representation in PAC which are then matched to speech templates in auditory association cortex. An alternative holds that speech activates a specialized system in cortex that does not use the primitives of PAC. Functional magnetic resonance imaging revealed different brain activation patterns in listening to speech and nonspeech sounds across different levels of complexity. Sensitivity to speech was observed in association cortex, as expected. Further, activation in HG increased with increasing levels of complexity with added fundamentals for both nonspeech and speech stimuli, but only for nonspeech when separate sources (release bursts/fricative noises or their nonspeech analogs) were added. These results are consistent with the existence of a specialized speech system which bypasses more typical processes at the earliest cortical level.
The Institute of Medical Illustrators' 36th annual conference, Dunblane, 17-19 September 2003.
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Avipox sp. in a colony of gray-crowned rosy finches (Leucosticte tephrocotis).
Members of a wild-caught colony of 16 gray-crowned rosy finches (Leucosticte tephrocotis) were presented with dermal and mucosal lesions, anorexia, emaciation, lethargy, and sudden death. Lesions included dermatitis, conjunctivitis, and glossitis. Skin scrapings from and bacterial culture of dermal lesions yielded Staphylococcus aureus and Candida albicans. Necropsy and histologic examination revealed characteristic epidermal and mucosal pox lesions, with the presence of characteristic Bollinger body intracellular inclusions. Electron microscopy (EM) provided confirmation of pox virus infection. This epornitic resulted in the death or euthanasia of 12 birds (75% morbidity and associated mortality) and was brought to conclusion through culling of affected birds. The source of infection remains unknown, although multiple modes of introduction exist. Similar epornitics may be prevented through indoor, species-specific housing, and quarantine. Vaccination and antiparasitic treatment may reduce the risk of disease spread.
Outpatient transfusion practice and factors leading to inpatient transfusion in a pediatric hematology/oncology program.
Oral mucositis continues to be a common and debilitating side effect of the conditioning regimens that use high-dose chemotherapy with or without radiation for pediatric bone marrow transplantation. Limited interventions have demonstrated success in preventing or treating it. Administration of glutamine, which is a nitrogen-rich amino acid found in the body, has emerged as a possible method of preventing oral mucositis in patients undergoing bone marrow transplantation. Numerous studies have looked at the effects of oral glutamine supplementation during bone marrow transplant. The purpose of this article is to describe glutamine and how it functions, review the literature regarding the use of oral glutamine in the prevention of oral mucositis in bone marrow transplantion, discuss the administration concerns related to the pediatric setting, and stress the importance of the nurse's role at the bedside. Nurses working in pediatric bone marrow transplant play a key role in the assessment of oral mucositis, administration of oral glutamine, and education of the patient and family.