Wolbachia: why these bacteria are important to genome research

Intracellular bacteria of the genus Wolbachia were first discovered in mosquitoes in the 1920s. Their superficial similarity to pathogenic rickettsia initially raised interest in them as potential human pathogens. However, injection experiments with mice showed that they were non-pathogenic, and they were subsequently classified as symbionts of insects. Until the 1970s, Wolbachia was considered to infect a limited number of species of mosquitoes. It is now clear that Wolbachia is an extremely common intracellular agent of invertebrates, infecting nearly all the major groups of arthropods and other terrestrial invertebrates. Its wide host range and abundance can be attributed partly to the unusual phenotypes it exerts on the host it infects. These include the induction of parthenogenesis (the production of female offspring from unmated mothers) in certain insects, the feminization of genetic male crustaceans to functional phenotypic females, and the failure of fertilization in hosts when males and females have a different infection status (cytoplasmic incompatibility). All of these phenotypes favor maternal transmission of the intracellular Wolbachia. In the last year, Wolbachia has also been shown to be a widespread symbiont of filarial nematodes. It appears that Wolbachia is needed by the adult worm for normal fertility, indicating that Wolbachia is behaving like a classic mutualist in this case. This discovery exemplifies that the extent of the host range of Wolbachia and its associated phenotypes is still far from fully understood.

Impact of Commercial Search Engines and International Databases on Engineering Teaching and Research

For the last three decades, the engineering higher education and professional environments have been completely transformed by the "electronic/digital information revolution" that has included the introduction of personal computer, the development of email and world wide web, and broadband Internet connections at home. Herein the writer compares the performances of several digital tools with traditional library resources. While new specialised search engines and open access digital repositories may fill a gap between conventional search engines and traditional references, these should be not be confused with real libraries and international scientific databases that encompass textbooks and peer-reviewed scholarly works. An absence of listing in some Internet search listings, databases and repositories is not an indication of standing. Researchers, engineers and academics should remember these key differences in assessing the quality of bibliographic "research" based solely upon Internet searches.

Young children, adolescents and alcohol - Part I: Exploring knowledge and awareness of alcohol and related issues

This article explores young children's and adolescents' views pertaining to: knowledge and awareness of alcohol and alcohol related issues; social situations in which. alcohol use is present; orientation to alcohol risk; perceived and actual alcohol use; social image and reputation; and short and long term health beliefs in relation to alcohol. Forty focus groups were conducted with 240 primary school students (118 males and 122 females) and 24 focus groups were conducted with 192 high school students (90 males and 102 females); the total being 64 focus groups comprising 432 school students. Participants ages ranged from five years three months to 16 years 10 months. The videotaped discussions revealed that approximately 75% of the primary school-aged children and almost all of the high school students reported that they had tasted alcohol. Parents were primarily responsible for providing the alcohol. Virtually all participants recognised and were able to correctly name a selection of alcoholic and non-alcoholic beverages, and levels of knowledge and awareness of the health and safety aspects of alcohol were relatively mixed. Presentation of bottles and cans was reported as being important in attracting young persons. These data suggest there is an urgent need for research addressed to the development of prevention/intervention education curriculum materials for use with primary school-aged children.

Young children, adolescents and alcohol - Part II: Reputation enhancement and self-concept

The research reported builds on our earlier work (Houghton, Carroll, & Odgers, 1998) which explored young children's and adolescents' views pertaining to knowledge and awareness of alcohol and alcohol-related issues. In this second study 640 (286 male and 354 female) school students randomly selected from five primary schools and five high schools in Perth, Western Australia participated. Data were obtained using The Which Group picture booklet questionnaire which comprises five parts and utilises illustrations (drawn by a professional children's artist) to gather information about children's and adolescents' orientations towards alcohol risk social situations, reputation enhancement, self-concept, and other related issues. Of the sample, 73% of males and 70.6% of females had tried alcohol, with beer being consumed most often. Significantly more participants in higher Year levels had tried alcohol. Over 90% said they drank at a party. Multivariate analysis revealed that nine of the 11 dependent variables contributed to the significant main effect of alcohol risk group, of which three were self-concept variables and six were reputation enhancement variables. It appears that individuals with the highest levels of orientation to alcohol risk believe that they are liked by their families, are physically attractive and have greater confidence in themselves. They also have higher levels of Admiration of Alcohol Related Activities and also of prosocial activities. While striving to attain a non-conforming reputation these individuals also wish to be ideally perceived by others as conforming. Gender and Age differences are investigated.

Health-related quality of life in Australian children with asthma: lessons for the cross-cultural use of quality of life instruments

The development of Australian forms of the Childhood Asthma Questionnaires (CAQs) is reported. Focus group methods and psychometric analyses were used to establish the conceptual, semantic and technical equivalence of these forms with the UK versions. Both versions also provide for data collection from non-asthmatic youngsters. The internal consistency was found to be acceptable (Cronbach's alpha 0.52-0.90) and the health-related quality of life (HRQoL) scores were found to vary with asthma severity (p < 0.05). Comparison with the UK data revealed that the non-asthmatic scores were higher for Australian than British children (p < 0.001) but that the scores for children with asthma did not differ between the two countries. It was only In the Australian sample that the group with asthma reported impaired HRQoL when compared to their healthy peers. These findings were interpreted in the context of cultural expectations of life quality and conclusions are presented regarding the importance of the gap between experience and expectations. The difficulties raised by the developmental and cultural issues inherent in paediatric HRQoL research were discussed. Qual. Life Res. 7:409-419 (C) 1998 Kluwer Academic Publishers

Anxious children and their parents: What do they expect?

Assigned 73 children, ages 7 to 14, to 1 of 3 groups (anxious, clinical control, and nonclinical control) according to their diagnostic status. Within the anxious group, children were assigned to 1 of 2 further groups on the basis of self-reported parental anxiety-either the child anxiety only group or the child + parent anxiety group. All children completed an experimental task (giving a brief talk in front of a video camera), which was the focus for a series of structured family discussions between the child and his or her parents. The aims of the study were to measure and compare across groups (a) the evaluations of children and their parents regarding the child's predicted anxiety and skill level and (b) the effect of the family discussion on children's expectations. Results indicated that, prior to the family discussion, anxious children's expectations of their future performance did not differ from those of control children. Similarly, there were no differences in children's expectations between the child anxiety group and the child + parent anxiety group. Second, compared to mothers in the child anxiety group, mothers in the child + parent anxiety group expected that their children would be more anxious and more likely to choose an avoidant problem solution (but not less skilled). Finally, the family discussion was found to produce no changes in anxious children's expectations of their future performance. The implications of these findings are discussed.

The functional outcome of children after a burn injury: A pilot study

Assessment of functional outcome can be used as a measure of the effectiveness of intervention during recovery from a burn injury. This pilot study identifies the factors that are likely to be most important for determining standardized functional outcome measures for children after a burn injury; it highlights the contribution of these factors to variations in children's postburn outcomes. A focus group of 8 parents and a self-report questionnaire administered to 12 children and 13 parents were the means of obtaining information for this exploratory study. Itching was found to be one of the primary impairments that contributed to reduced functional outcome during skin healing after a burn injury. The activities of children who had been burned that were most frequently affected by the injury (as reported by parents) were schoolwork and sports; these were closely followed by sleeping, playing with other children, and unliked activities. Least affected activities were enjoying the family, eating, seeing friends, watching television, and bathing or showering. Eighty-five percent of parents reported at least some level of interference with the listed daily activities. Burn injuries are likely to cause interference with several aspects of a patient's daily life. As a result, families require ongoing support and monitoring. Further research should longitudinally compare the performance of children who have been burned with other children and adolescents.

A six-year longitudinal study of the relationship of physical activity to bone mineral accrual in growing children: The University of Saskatchewan bone mineral accrual study

To investigate the influence of physical activity on bone mineral accrual during the adolescent years, we analyzed 6 years of data from 53 girls and 60 boys. Physical activity, dietary intakes, and anthropometry were measured every 6 months and dual-energy X-ray absorptiometry scans of the total body (TB), lumbar spine (LS), and proximal femur (Hologic 2000, array mode) were collected annually. Distance and velocity curves for height and bone mineral content (BMC) were fitted for each child at several skeletal sites using a cubic spline procedure, from which ages at peak height velocity (PHV) and peak BMC velocity (PBMCV) were identified. A mean age- and gender-specific standardized activity (Z) score was calculated for each subject based on multiple yearly activity assessments collected up until age of PHV. This score was used to identify active (top quartile), average (middle 2 quartiles), or inactive (bottom quartile) groups. Two-way analysis of covariance, with height and weight at PHV controlled for, demonstrated significant physical activity and gender main effects (but no interaction) for PBMCV, for BMC accrued for 2 years around peak velocity, and for BMC at 1 year post-PBMCV for the TB and femoral neck and for physical activity but not gender at the LS (all p < 0.05). Controlling for maturational and size differences between groups, we noted a 9% and 17% greater TB BMC for active boys and girls, respectively, over their inactive peers 1 year after the age of PBMCV. We also estimated that, on average, 26% of adult TB bone mineral was accrued during the 2 years around PBMCV.

Parental reactions to infant death: The effects of resources and coping strategies

The aim of this research was to examine, from a stress and coping perspective, the effects of resources (both personal and environmental) and coping strategies on parental reactions to infant death. One hundred and twenty-seven parents (60 fathers, 67 mothers) participated in the study. The predictors of parental distress (background factors, resources, coping methods) were initially assessed at 4-6 weeks post-loss. Parental distress (assessed using a composite measure of psychiatric disturbance, physical symptoms, and perinatal grief) was further assessed at 6 months post-loss and at 15 months postloss. After control for the stability in adjustment across time, there was consistent evidence that higher levels of education were associated with lower levels of parental distress over time. Among mothers, the number of friends in whom mothers had the confidence to confide emerged as a positive predictor of adjustment to infant death. A reliance on problem-focused coping was associated with greater maternal distress at 6 months post-loss, whereas coping by seeking support was associated with less distress at 15 months post-loss. There is no evidence that background factors and resources influenced parental distress through coping.

Mothers' mental illness and child behavior problems: Cause-effect association or observation bias

Objective: A number, of studies have consistently found that a mother's mental health (particularly her level of depression) is a strong predictor of mental health problems experienced by her child(ren). However, the validity of this finding is in doubt because the majority of these studies have relied on maternal reports as indicators of children's behavior. Method: This prospective, longitudinal study examines data an the mental health of the mother from prior to the birth of her child to when the child reaches 14 years of age. Child behavior is measured at 14 years of age using reports from mother and child. Mother and child responses are compared to provide an indication of the possible magnitude of maternal observation bias in the reporting of child behavior problems. Results: Anxious and/or depressed mothers tend to report more cases of child behavior problems than do their mentally healthy counterparts or children themselves. Differences between mothers and youths In reporting behavior problems appear to be related to the mothers' mental health. Conclusions: Current maternal mental health impairment appears to have a substantial effect on the reporting of child behavior problems by the mother, thereby raising questions about the validity of reports of child behavior by persons who are currently emotionally distressed.

Goals and reputations amongst young children - The validation of the importance of goals and reputation enhancement scales

The aim of the present research was to provide school psychologists with valid instruments with which to assess the goals and reputations of young children. This was achieved by ascertaining whether the factor structures and the second-order factor models of the high school versions of the Importance of Goals (Carroll, et al., 1997) and Reputation Enhancement Scales (Carroll, et al., 1999) could be replicated with a primary school sample. Eight hundred and eighty-six 10 to 12 year old children were administered modified versions of the two scales, which were combined and renamed the Children's Activity Questionnaire. For the two scales, the factor structure proved replicable and reliable with the primary school sample. A comparison between the factor loadings of the primary school and the high school samples using the coefficient of congruence procedure demonstrated similarity indicating that the scales are replicable and able to be used with a younger primary school sample. Structural equation modelling indicated that the second-order factor structure of the Importance of Goals Scale was acceptable but this was not the case for the second-order factor structure of the Reputation Enhancement Scale.

Analysis of proximal femur DXA scans in growing children: Comparisons of different protocols for cross-sectional 8-month and 7-year longitudinal data

Dual-energy X-ray absorptiometry (DXA) is a widely used method for measuring bone mineral in the growing skeleton. Because scan analysis in children offers a number of challenges, we compared DXA results using six analysis methods at the total proximal femur (PF) and five methods at the femoral neck (FN), In total we assessed 50 scans (25 boys, 25 girls) from two separate studies for cross-sectional differences in bone area, bone mineral content (BMC), and areal bone mineral density (aBMD) and for percentage change over the short term (8 months) and long term (7 years). At the proximal femur for the short-term longitudinal analysis, there was an approximate 3.5% greater change in bone area and BMC when the global region of interest (ROI) was allowed to increase in size between years as compared with when the global ROI was held constant. Trend analysis showed a significant (p < 0.05) difference between scan analysis methods for bone area and BMC across 7 years. At the femoral neck, cross-sectional analysis using a narrower (from default) ROI, without change in location, resulted in a 12.9 and 12.6% smaller bone area and BMC, respectively (both p < 0.001), Changes in FN area and BMC over 8 months were significantly greater (2.3 %, p < 0.05) using a narrower FN rather than the default ROI, Similarly, the 7-year longitudinal data revealed that differences between scan analysis methods were greatest when the narrower FN ROI was maintained across all years (p < 0.001), For aBMD there were no significant differences in group means between analysis methods at either the PF or FN, Our findings show the need to standardize the analysis of proximal femur DXA scans in growing children.

Estimating the cost of contact for non-resident parents: A budget standards approach

Most Western countries have, for some time, provided income support and/or taxation relief to parents with children in their care. The significant amount of research into the costs of children to couple and sole parent households has been important in assessing and developing family support policies. Changing societal expectations about the level of involvement of fathers in child rearing activities has highlighted the need to understand the costs facing usually male non-resident parents in having contact with their children. The budget standards methodology is used in this paper to estimate the costs for non-resident parents exercising regular contact with their children. Costs of contact are found to be high. For contact with one child for 20 per cent of the year, costs of contact represent about 40 per cent of the costs of that same child in an intact couple household with a medium income and more than half of the costs of that child in a household with low income. Household infrastructure and transportation is the reason for high costs. One implication of this finding is that the total cost of children substantially increases when parents separate. The article discusses some policy implications of these findings. This research is of relevance to social security, taxation, family law and child support policies and administration.