Showing papers by "Andrew J. Martin published in 2004"

Reduced neurocognition in children who snore.

Abstract: Obstructive sleep apnea syndrome (OSAS) has been associated with reduced neurocognitive performance in children, but the underlying etiology is unclear. The aim of this study was to evaluate the relationship between hypoxemia, respiratory arousals, and neurocognitive performance in snoring children referred for adenotonsillectomy. Thirteen snoring children who were referred for evaluation regarding the need for adenotonsillectomy to a children's hospital otolaryngology/respiratory department underwent detailed neurocognitive and polysomnographic (PSG) evaluation. PSGs were evaluated for respiratory abnormalities and compared with 13 nonsnoring control children of similar age who were studied in the same manner. The snoring children had an obstructive respiratory disturbance index within normal range (mean obstructive apnea/hypopnea index, 0.6/hr). Despite this, several domains of neurocognitive function were reduced in the snoring group. These included mean verbal IQ scores (snorers 92.6 vs. nonsnorers 110.2, P or = 3%, obstructive hypopneas with > or = 3% oxygen desaturations, and respiratory arousals and severity of neurocognitive deficits, with the greatest effect being on memory scores. The disruption of sleep in snoring children produced by relatively mild changes in oxygen saturation or by increases in respiratory arousals may have a greater effect on neurocognitive function than hitherto appreciated. A possible explanation for these neurocognitive deficits may be the combination of the chronicity of sleep disruption secondary to snoring which is occurring at a time of rapid neurological development in the first decade of life. Future studies need to confirm the reversal of these relatively mild neurocognitive decrements post adenotonsillectomy.

School motivation of boys and girls: Differences of degree, differences of kind, or both?

Abstract: The present study sought to explore invariance in factor structure, cluster profiles, and perceptual mapping in student motivation as a function of gender. Among a sample of 2,927 Australian high school students, motivation differences were explored using the Student Motivation Scale (Martin, 2001, 2002a, 2002b). The data clearly show that there are differences in the degree to which boys and girls are motivated, although generally effect sizes are small. Girls are statistically significantly higher in learning focus, planning, study management, and persistence while boys are significantly higher in self-sabotage or self-handicapping. Interestingly, girls are also significantly higher in anxiety. However, across boys and girls there is invariance in factor structure, cluster profiles, and perceptual mapping suggesting that there are no fundamental motivational differences of kind. That is, in relation to key facets of motivation, there is a highly similar factor structure across boys and girls, boys and girls can be grouped into parallel motivation clusters, and boys and girls seem to perceptually locate key motivational dimensions in similar ways. It is concluded that although girls have higher levels of motivation than boys on a number of dimensions, the two groups' fundamental motivation orientations do not appear to be markedly qualitatively different. This holds implications not only for data analysis but also for programmatic intervention aimed at enhancing or sustaining boys' and girls' motivation.

Discovering mental toughness : a qualitative study of mental toughness in elite athletes

Abstract: What is mental toughness? This research draws on the experience of elite athletes and coaches to unearth a conceptualisation and definition of mental toughness. The interviews of 33 elite athletes and coaches (including 25 current or former elite athletes, of whom 15 had achieved an Olympic Gold Medal or World Champion status) were transcribed verbatim and analysed qualitatively to reveal underpinning components of mental toughness. Mental toughness is multi-dimensional and consists of twelve components, including: self-efficacy, potential, mental selfconcept, task familiarity, value, personal bests, goal commitment, perseverance, task focus, positivity, stress minimisation, and positive comparisons. Mental toughness is defined as an unshakeable perseverance and conviction towards some goal despite pressure or adversity. This conceptualisation of mental toughness provides a platform from which instruments of measurement can be developed.

Restrictions to the Adaptation of Influenza A Virus H5 Hemagglutinin to the Human Host

Abstract: The binding specificities of a panel of avian influenza virus subtype H5 hemagglutinin (HA) proteins bearing mutations at key residues in the receptor binding site were investigated. The results demonstrate that two simultaneous mutations in the receptor binding site resulted in H5 HA binding in a pattern similar to that shown by human viruses. Coexpression of the ion channel protein, M2, from most avian and human strains tested protected H5 HA conformation during trafficking, indicating that no genetic barrier to the reassortment of the H5 surface antigen gene with internal genes of human viruses existed at this level.

The psychological performance inventory: Is the mental toughness test tough enough?

Abstract: Mental toughness, stemming in part from Loehr's 1986 classic research, is widely alluded to as a critical variable in the popular media and applied sport psychology. We evaluated the construct validity of responses to Loehr's (1986) Psychological Performance Inventory (PPI) by 263 student-athletes from an elite sports high school. As confirmatory factor analysis yielded a poor model fit and an improper solution for the a priori model, we pursued exploratory factor analyses that resulted in a 5-factor model that fitted the data well. However, further analyses showed that key correlates of mental toughness were more strongly correlated with the factors based on the original structure than factors based on the alternative structure. In conclusion, neither the original PPI nor the subset of PPI items in the better-fitting alternative model was a sound measure of mental toughness, indicating that a good fit is a necessary but not sufficient condition for construct validation. Good instrumentation must be strong in terms of conceptual/theoretical considerations, psychometric properties, and relationships to key correlates hypothesised to be meaningfully related to it.

PDBSprotEC: a Web-accessible database linking PDB chains to EC numbers via SwissProt

Abstract: Summary: A mapping between chains in the Protein Databank and Enzyme Classification numbers is invaluable for research into structure--function relationships. Mapping at the chain level is a non-trivial problem and we present an automatically updated Web-server, which provides this link in a queryable form and as a downloadable XML or flat file. Availability: The query interface and downloadable files may be accessed at http://www.bioinf.org.uk/pdbsprotec/ Supplementary information: Further details of the methods used are available at http://www.bioinf.org.uk/pdbsprotec/methods/

Poisoning in Older Adults: A 5-Year Experience of US Poison Control Centers

Abstract: BACKGROUNDPoisoning in older adults has received relatively little attention.OBJECTIVETo describe poison exposures in older adults reported to US poison centers and identify substances that pose a unique risk to this population. METHODS: A retrospective review of human exposures for patients aged 60 years reported to the American Association of Poison Control Center's Toxic Exposure Surveillance System from 1993 to 1997 was performed. Frequencies and cross-tabulations were used to describe the data. Hazard factor analysis was conducted to identify medications that pose risk in this population. Statistical analysis included χ2 and Fisher's exact test for hazard factors.RESULTSA total of 298 713 poison exposure cases were reported to US poison centers involving individuals aged 60 years between 1993 and 1997. The proportion of cases in this age group also steadily increased from 2.5% of all cases in 1993 to 3.4% of all cases in 1997. The mean age of the patients was 64.7 years, and 34.1% were males. Hazar...

Audio-visual interfaces in digital art

Abstract: This paper outlines the evolution, in the history of art and technology, of image-sound interface systems. This can be called the evolution of the "audiovisual discourse" in art and technology. Recent software for audio and visual material manipulation is briefly described and audiovisual digital art works, developed during the COSTART Research Project, are illustrated as examples of contemporary artistic projects concerned with this theme. Different artistic approaches in the use of audiovisual systems are identified on the basis of the historical research and the author's work, as artist and technologist, in collaboration with the artists participating to the project. Finally the role of the computer as audiovisual instrument is discussed.