Relating body mass index to figural stimuli: population-based normative data for Caucasians

OBJECTIVE: To establish body mass index (BMI) norms for standard figural stimuli using a large Caucasian population-based sample. In addition, we sought to determine the effectiveness of the figural stimuli to identify individuals as obese or thin. DESIGN: All Caucasian twins born in Virginia between 1915 and 1971 were identified by public birth record. In addition, 3347 individual twins responded to a letter published in the newsletter of the American Association of Retired Persons (AARP). All adult twins (aged 18 and over) from both of these sources and their family members were mailed a 16 page 'Health and Lifestyle' questionnaire. SUBJECTS: BMI and silhouette data were available on 16 728 females and 11 366 males ranging in age from 18- 100. MEASUREMENTS: Self-report information on height-weight, current body size, desired body size and a discrepancy score using standard figural stimuli. RESULTS: Gender- and age-specific norms are presented linking BMI to each of the figural stimuli. Additional norms for desired body size and discrepancy scores are also presented. Receiver operating curves (ROC) indicate that the figural stimuli are effective in classifying individuals as obese or thin. CONCLUSIONS: With the establishment of these norms, the silhouettes used in standard body image assessment can now be linked to BMI. Differences were observed between women and men in terms of desired body size and discrepancy scores, with women preferring smaller sizes. The figural stimuli are a robust technique for classifying individuals as obese or thin.

Genetic and non-genetic factors affecting birth-weight and adult body mass index

Birthweight affects neonatal mortality and morbidity and has been used as a marker of foetal undernutrition in studies of prenatal effects on adult characteristics. It is potentially influenced by genetic and environmental influences on the mother, and effects of foetal genotype, which is partially derived from the maternal genotype. Interpretations of variation in birthweight and associated characteristics as being due to prenatal environment ignore other possible modes of materno-foetal transmission. Subjects were adult twins recruited through the Australian Twin Registry, aged 17 to 87 years, and the sample comprised 1820 men and 4048 women. Twins reported their own birthweight as part of a health questionnaire. Body Mass Index (BMI) was calculated from self-reports of height and weight. Correlations between co-twins' birthweights were high for both monozygotic (r = 0.77) and dizygotic (r = 0.67) pairs, leading to substantial estimates of shared environmental effects (56% of variance) with significant additive genetic (23%) and non-shared environmental (21%) components. Adult BMI was mainly influenced by genetic factors, both additive (36% of variance) and nonadditive (35%). The correlation between birthweight and BMI was positive, in that heavier babies became on average more obese adults. A bivariate model of birthweight and adult BMI showed significant positive genetic (rg = 0.16, p = 0.005) and environmental (re = 0.08, p = 0.000011) correlations. Intra-uterine environmental or perinatal influences shared by cotwins exercise a strong influence on birthweight, but the factors which affect both birthweight and adult BMI are partly genetic and partly non-shared environmental.

Efficiency of delivery of DNA to cells by bovine papillomavirus type-1 L1/L2 pseudovirions

To investigate the efficiency of encapsidation of plasmid by papillomavirus virus-like particles (PV VLPs), and the infectivity of the resultant PV pseudovirions, Cos-1 cells were transfected with an 8-kb plasmid incorporating a green fluorescent protein (GFP) reporter gene (pGSV), and infected with bovine PV (BPV-1) L1/L2 recombinant vaccinia virus to produce BPV1 pseudovirions. Approximately 1 in 1.5x10(4) of dense (1.35 g/ml) PV pseudovirions and 0.3 in 10(4) Of less-dense (1.29 g/ml) pseudovirions packaged an intact pGSV plasmid. The majority (>75%) of packaged plasmids contained deletions, and the deletions affected all tested genes. After exposure of Cos-1 cells to BPV-1 pseudovirions at an MOI of 40,000:1, 6% of cells expressed GFP giving a calculated efficiency of delivery of the pGSV plasmid, by pseudovirions which had packaged an intact plasmid, of approximately 5%. Plasmid delivery was not effected by purified pGSV plasmid, was blocked by antiserum against BPV-1, and was not blocked by DNase treatment of pseudovirions, confirming that delivery was mediated by DNA within the pseudovirion. We conclude that a major limitation to the use of PV pseudovirions as a gene delivery system is that intact plasmid DNA is not efficiently selected for packaging by VLPs in cell-based pseudovirions production systems.

Patient based method of assessing adverse events in clinical trials in rheumatology: the revised Stanford Toxicity Index

We describe the progress towards developing a patient rated toxicity index that meets all of the patient-important attributes defined by the OMERACT Drug Safety Working Party, These attributes are frequency, severity. importance to patient, importance to the clinician, impact on economics, impact on activities, and integration of adverse effects with benefits. The Stanford Toxicity Index (STI) has been revised to collect all attributes with the exception of impact on activities. However, since the STI is a part of the Health Assessment Questionnaire (HAQ). impact on activities is collected by the HAQ. In particular, a new question asks patients to rate overall satisfaction, taking into consideration both benefits and adverse effects. The nest step in the development of this tool is to ensure that the STI meets the OMERACT filter of truth, discrimination, and feasibility. Although truth and feasibility have been confirmed by comparisons within the ARAMIS database, discrimination needs to be assessed in clinical trials.

Body mass index and the prediction of percentage body fat in Australian Chinese women

Background Body mass index (BMI) is frequently related to percentage body fat. Nevertheless, the relationship between BMI and fat mass/height(2) (FM/H-2), theoretically, should be more appropriate. Aim: This study seeks to evaluate the relationship between BMI and both percentage body fat and FM/H-2 in a group of Chinese Australian females. Subjects and methods: Forty subjects took part in the study and all were Chinese females resident in Brisbane, Australia. Body mass index was calculated from height and weight. Percentage body fat and fat mass were calculated from measurements of total body water. Results: The use of BMI to predict FM/H-2 accounted for double the variance of that found when BMI was used to predict percentage body fat. Conclusions: As a consequence, it is possible that the use of BMI to predict FM/H-2 and not percentage body fat in the first instance may prove to be more useful in a number of adult populations. Nevertheless, with a relatively small sample size it is difficult, if not impossible, to test the developed equations on a validation group and further investigation into the findings described in this paper needs to be undertaken.

Quantitative PCR-ELAHA for the determination of retroviral vector transduction efficiency

Current methods to detect transduction efficiency during the routine use of integrating retroviral vectors in gene therapy applications may require the use of radioactivity and usually rely upon subjective determination of the results. We have developed two competitive quantitative assays that use an enzyme-linked, amplicon hybridization assay (ELAHA) to detect the products of PCR-amplified regions of transgene from cells transduced with Moloney murine leukemia virus vectors. The quantitative assays (PCR-ELAHA) proved to be simple, rapid, and sensitive, avoiding the need for Southern hybridization, complex histochemical stains, or often subjective and time-consuming tissue culture and immunofluorescence assays. The PCR-ELAHA systems can rapidly detect proviral DNA from any retroviral vector carrying the common selective and marker genes neomycin phosphotransferase and green fluorescent protein, and the methods described are equally applicable to other sequences of interest, providing a cheaper alternative to the evolving real-time PCR methods. The results revealed the number of copies of retrovector provirus present per stably transduced cell using vectors containing either one or both qPCR targets.

A proposed maceral index to predict combustion behavior of coal

To predict the combustion performance in pulverized coal-fired boilers, this paper examines existing indices and develops a maceral index (MI). These indices were compared with the data of 68 coals and blends in a range of the mean vitrinite reflectance from 0.25 to 1.63. The results showed that the fuel ratio and the mean vitrinite reflectance could qualitatively indicate the burnout of the coals and blends. The new MI, MI = L + V/R-2/I-1.25(HV/30)(2.5), provides a useful correlation for the burnout of the coals and blends. The correlation coefficient (I-) is 0.982 for the EER data, and 0.808 for the ACIRL data. The MI also has potential to correlate ignition and flame stability of the coals and blends. The MI predicts the burnout better than the other indices. (C) 2001 Elsevier Science Ltd. All rights reserved.

Reproduction in the squirrel glider, Petaurus norfolcensis (Petauridae) in south-east Queensland

Reproduction was studied across a three-year period in two south-east Queensland populations of the squirrel glider, Petaurus norfolcensis, by measuring morphological (body weight, scrotal diameter, cutaneous scent-gland activity, condition index) and physiological (plasma steroid levels) variables. Reproduction showed a seasonal pattern, with peak numbers of pouch young recorded in late autumn and winter. Declines in oestrogen concentrations outside the breeding period indicate that females are anoestrous in the summer months. Most (83%) reproductive females captured during the study were 2-3 years old, but all individuals over one year of age were found to have bred. Average litter size was 1.73 +/- 0.01 (n = 23). Scrotal diameter and testosterone concentrations showed no significant seasonal variation. It is suggested that this is due to the presence of both socially dominant and subordinate males in the data set. Maximum testosterone concentrations did coincide with periods of mating. The condition index showed no relationship with reproductive variables, but it is likely that this results from the manner in which the index was generated.

Biogeographical concordance and efficiency of taxon indicators for establishing conservation priority in a tropical rainforest biota

Prioritizing areas for conservation requires the use of surrogates for assessing overall patterns of biodiversity. Effective surrogates will reflect general biogeographical patterns and the evolutionary processes that have given rise to these and their efficiency is likely to lie influenced by several factors, including the spatial scale of species turnover and the overall congruence of the biogeographical history. We examine patterns of surrogacy for insects, snails, one family of plants and vertebrates from rainforests of northeast Queensland, an area characterized by high endemicity and an underlying history of climate-induced vicariance. Nearly all taxa provided some level of prediction of the conservation values For others. However, despite an overall correlation of the patterns of species richness and complementarity, the efficiency of surrogacy was highly asymmetric.. snails and insects were strong predictors of conservation priorities for vertebrates, but not vice versa. These results confirm predictions that taxon surrogates can be effective in highly diverse tropical systems where there is a strong history of vicariant biogeography, but also indicate that correlated patterns for species richness and/or complementarity do not guarantee that one taxon will be efficient as a surrogate for another. In our case, the highly diverse and narrowly distributed invertebrates were more efficient as predictors than the less diverse and more broadly distributed vertebrates.

The management of rice grown on raised beds with continuous furrow irrigation

A field experiment compared two rice (Oryza sativa L.) cropping systems: paddy or raised beds with continuous furrow irrigation; and trialled four cultivars: Starbonnet, Lemont, Amaroo and Ceysvoni, and one test line YRL39; that may vary in adaptation to growth on raised beds. The grain yield of rice ranged from 740 to 1250 g/m(2) and was slightly greater in paddy than on raised beds. Although there were early growth responses to fertilizer nitrogen on raised beds, the crop nitrogen content at maturity mostly exceeded 20 g/m(2) in both systems, so nitrogen was unlikely to have limited yield. Ceysvoni yielded best in both systems, a result of good post-anthesis growth and larger grain size, although its whole-grain mill-out percentage was poor relative to the other cultivars. Starbonnet and Lemont yielded poorly on raised beds, associated with too few tillers and too much leaf area. When grown on raised beds all cultivars experienced a delay in anthesis resulting in more tillers, leaf area and dry weight at anthesis, and probably a greater yield potential. The growth of rice after anthesis, however, was similar on raised beds and in paddy, so reductions in harvest index and grain size on raised beds were recorded. The data indicated that water supply was not a major limitation to rice growth on raised beds, but slower crop development was an issue that would affect the use of raised beds in a cropping system, especially in rice-growing areas where temperatures are too cool for optimal crop development. (C) 2001 Elsevier Science B.V. All rights reserved.

The influence of age on reproductive performance in the Brown Thornbill

I examined age effects on reproduction in the Brown Thornbill Acanthiza pusilla in Canberra, Australia. I found that the reproductive performance of both males and females improved with age, although only age-related improvement in male performance had a significant effect on annual reproductive success. Reproductive success improved with male age as a result of improved performance during two stages of the breeding cycle: first-year males were less likely to fledge young than those aged two or more, while both first and second-year males were less successful at raising fledglings to independence than males of three or more. Male performance appears to improve over three years as they gain experience at provisioning nestlings and caring for fledglings without attracting predators, rather than as a direct result of improved foraging skills. In contrast, reproductive success only improved slightly with female age, although females of two or more years initiated their first clutch earlier in the season than one-year-old females, and tended to be mure likely to re-nest if a breeding attempt failed. The poor performance of young females appears unlikely to be related to their foraging ability but may be associated with costs imposed by dispersing to a breeding vacancy earlier in the year. Although the reproductive performance of Brown Thornbills improves considerably with age 1 found no evidence that performance improved as a result of repeated breeding attempts with the same partner.

Modulation of the adrenocortical stress response in marine turtles (Cheloniidae): evidence for a hormonal tactic maximizing maternal reproductive investment

The relationships between reproductive condition, level of reproductive investment and adrenocortical modulation to capture stress in marine turtles form the basis of this study. When subjected to either capture or ecological stressors, nesting marine turtles have demonstrated adrenocortical responses that are both small in magnitude, and slow in responsiveness. These observations were further investigated to determine whether this minimal stress response was a physiological strategy to maximize reproductive investment in adult green Chelonia mydas and hawksbill Eretmochelys imbricata turtles. Female green and hawksbill turtles exhibited a decrease in adrenocortical responsiveness with progressive reproductive condition. Breeding turtles exhibited most suppression of their adrenocortical response to capture compared to both non-breeding and pre-breeding female counterparts. Nesting green turtles maintained a suppressed adrenocortical response to capture throughout the nesting season despite decreased reproductive investment. In contrast, male green and hawksbill turtles were less able to modulate their corticosterone (B) response to acute capture stress. During breeding, male turtles possessed significantly greater adrenocortical responses to capture than females. These results could indicate that the large reproductive investment necessary for female marine turtle reproduction might underlie the marked decrease in adrenocortical responsiveness. This hormonal mechanism could function as one strategy by which female marine turtles maximize their current reproductive event, even though under certain situations this mechanism could entail costs to female survival.