Genetic and environmental sources of covariance between reading tests used in neuropsychological assessment and IQ subtests

In this study, we examined genetic and environmental influences on covariation among two reading tests used in neuropsychological assessment (Cambridge Contextual Reading Test [CCRT], [Beardsall, L., and Huppert, F. A. ( 1994). J. Clin. Exp. Neuropsychol. 16: 232 - 242], Schonell Graded Word Reading Test [SGWRT], [ Schonell, F. J., and Schonell, P. E. ( 1960). Diagnostic and attainment testing. Edinburgh: Oliver and Boyd.]) and among a selection of IQ subtests from the Multidimensional Aptitude Battery (MAB), [Jackson, D. N. (1984). Multidimensional aptitude battery, Ontario: Research Psychologists Press.] and the Wechsler Adult Intelligence Scale-Revised (WAIS-R) [Wechsler, D. (1981). Manual for the Wechsler Adult Intelligence Scale-Revised (WAIS-R). San Antonio: The Psychological Corporation]. Participants were 225 monozygotic and 275 dizygotic twin pairs aged from 15 years to 18 years ( mean, 16 years). For Verbal IQ subtests, phenotypic correlations with the reading tests ranged from 0.44 to 0.65. For Performance IQ subtests, phenotypic correlations with the reading tests ranged from 0.23 to 0.34. Results of Structural Equation Modeling (SEM) supported a model with one genetic General factor and three genetic group factors ( Verbal, Performance, Reading). Reading performance was influenced by the genetic General factor ( accounting for 13% and 20% of the variance for the CCRT and SGWRT, respectively), the genetic Verbal factor ( explaining 17% and 19% of variance for the CCRT and SGWRT), and the genetic Reading factor ( explaining 21% of the variance for both the CCRT and SGWRT). A common environment factor accounted for 25% and 14% of the CCRT and SGWRT variance, respectively. Genetic influences accounted for more than half of the phenotypic covariance between the reading tests and each of the IQ subtests. The heritabilities of the CCRT and SGWRT were 0.54 and 0.65, respectively. Observable covariance between reading assessments used by neuropsychologists to estimate IQ and IQ subtests appears to be largely due to genetic effects.

A proposed new classification system for whiplash associated disorders - implications for assessment and management

The development of chronic symptoms following whiplash injury is common and contributes substantially to costs associated with this condition. The currently used Quebec Task Force classification system of whiplash associated disorders is primarily based on the severity of signs and symptoms following injury and its usefulness has been questioned. Recent evidence is emerging that demonstrates differences in physical and psychological impairments between individuals who recover from the injury and those who develop persistent pain and disability. Motor dysfunction, local cervical mechanical hyperalgesia and psychological distress are present soon after injury in all whiplash injured persons irrespective of recovery. In contrast those individuals who develop persistent moderate/severe pain and disability show a more complex picture, characterized by additional impairments of widespread sensory hypersensitivity indicative of underlying disturbances in central pain processing as well as acute posttraumatic stress reaction, with these changes present from soon after injury. Based on this heterogeneity a new classification system is proposed that takes into account measurable disturbances in motor, sensory and psychological dysfunction. The implications for the management of this condition are discussed. (C) 2004 Elsevier Ltd. All rights reserved.

Policies for saving a rare Australian glider: economics and ecology

This paper considers the economics of conserving a species with mainly non-use value, the endangered mahogany glider. Three serial surveys of Brisbane residents provide data on the knowledge of respondents about the mahogany glider. The results supply information about the attitudes of respondents to the mahogany glider, to its conservation and relevant public policies, and about variations in these factors as the knowledge of participants of the mahogany glider alters. Similarly, data are provided and analysed about the willingness to pay of respondents to conserve the mahogany glider and how it changes. Population viability analysis is applied to estimate the required habitat area for a minimum viable population of the mahogany glider to ensure at least a 95% probability of its survival for 100 years. Places are identified in Queensland where the requisite minimum area of critical habitat can be conserved. Using the survey results as a basis, the likely willingness of groups of Australians to pay for the conservation of the mahogany glider is estimated and consequently their willingness to pay for the minimum required area of its habitat. Methods for estimating the cost of protecting this habitat are outlined. Australia-wide benefits are estimated to exceed the costs. Establishing a national park containing the minimum viable population of the mahogany glider is an appealing management option. This would also be beneficial in conserving other endangered wildlife species and ecosystems. Therefore, additional economic benefits to those estimated on account of the mahogany glider itself can be obtained. (C) 2004 Elsevier Ltd. All rights reserved.

Phenolic acids and abscisic acid in Australian Eucalyptus honeys and their potential for floral authentication

Seven phenolic acids related to the botanical origins of nine monofloral Eucalyptus honeys from Australia, along with two abscisic isomers, have been analyzed. The mean content of total phenolic acids ranges from 2.14 mg/100 g honey of black box (Eucalyptus largiflorens) honey to 10.3 mg/100 g honey of bloodwood (Eucalyptus intermedia) honey, confirming an early finding that species-specific differences of phytochemical compositions occur quantitatively among these Eucalyptus honeys. A common profile of phenolic acids, comprising gallic, chlorogenic, coumaric and caffeic acids, can be found in all the Eucalyptus honeys, which could be floral markers for Australian Eucalyptus honeys. Thus, the analysis of phenolic acids could also be used as an objective method for the authentication of botanical origin of Eucalyptus honeys. Moreover, all the honey samples analyzed in this study contain gallic acid as the main phenolic acid, except for stringybox (Eucalyptus globoidia) honey which has ellagic acid as the main phenolic acid. This result indicates that the species-specific differences can also be found in the honey profiles of phenolic acids. Further-more, the analysis of abscisic acid in honey shows that the content of abscisic acid varies from 0.55 mg/100 g honey of black box honey to 4.68 mg/ 100 g honey of bloodwood honey, corresponding to the contents of phenolic acids measured in these honeys. These results have further revealed that the HPLC analysis of honey phytochemical constituents could be used individually and/or jointly for the authentication of the botanical origins of Australian Eucalyptus honeys. (C) 2003 Elsevier Ltd. All rights reserved.

Factors underlying support or opposition to biotechnology among Australian food consumers and implications for retailer-led food regulation

Despite current findings that consumers, on average, have negative attitudes to biotechnologies such as cloning and genetic engineering, considerable variability can be found in the direction and strength of these attitudes. This paper presents a path analysis of attitudinal, motivational, demographic and behavioural variables that influence consumer dispositions towards biotechnology. Among these variables, those found to be most important were: consumers' level of motivation to find natural foods; the extent to which they were motivated by convenience; whether they did the shopping for their household on a regular basis; and their sex. In terms of direct effects on dispositions to biotechnology, motivation to find natural foods had a very strong negative effect while convenience had a very strong positive effect. Sex had a moderate direct effect with women less likely to be positively disposed towards biotechnology than men. In an apparent contradiction, taking responsibility for household shopping had an equally strong positive effect on both naturalness and convenience. However, sex also played a crucial role here with a very strong effect on motivation to find natural foods (women more motivated), a minor effect on convenience (women less motivated) and a strong effect on responsibility for household shopping (women more likely to shop). The policy implications of these findings are important, given the apparent oppositional trends of some sections of the food industry to endorse biotechnology, and of the supermarkets to deliver `clean and green' non-GM foods to consumers. (c) 2005 Elsevier Ltd. All rights reserved.