A family-based intervention to increase fruit and vegetable consumption in adolescents : a pilot study

Objective: To evaluate the feasibility and effectiveness of a pilot family-based newsletter intervention to increase fruit and vegetable (FV) consumption among adolescents.
Design: Family-based, two-group randomised control trial with baseline, postintervention and follow-up measures. The intervention group received two FV newsletter packs over a 1 month period by postal mail. Social cognitive and behavioural choice theories provide the theoretical framework for the design and development of intervention materials. Control families were provided with all intervention materials at the end of the study. Adolescent FV consumption was assessed by an FFQ. Adolescent-reported barriers to eating FV, FV habits and preferences were the secondary outcomes, along with parent FV consumption, and parents reported knowledge, encouragement, home availability and accessibility of FV. Repeated-measures ANOVA was used to detect differences in behavioural and psychosocial outcomes between groups, time and group-by-time.
Setting: East Midlands, UK.
Subjects: Forty-nine parents and adolescents aged 12–14 years.
Results: Process evaluation indicated high reach, dose acceptability and fidelity of the intervention. At post-intervention and 6 weeks later at follow-up, adolescents in the intervention group had significantly higher fruit: (P0<·01) and vegetable (P<0·05) consumption and higher preferences for vegetables (P<0·01), compared with the control group. At post-intervention and follow-up, parents in the intervention group had significantly higher fruit (P<0·001) and vegetable (P<0·01) consumption and reported higher accessibility of fruit and vegetables (P<0·001), compared with those in the control group.
Conclusions: Family-based, newsletter interventions promoting FV consumption to adolescents appear to be feasible and effective at increasing FV consumption.

A cluster randomised trial of a telephone-based intervention for parents to increase fruit and vegetable consumption in their 3-to 5-year-old children : study protocol

Background: Inadequate fruit and vegetable consumption in childhood increases the risk of developing chronic disease. Despite this, a substantial proportion of children in developed nations, including Australia, do not consume sufficient quantities of fruits and vegetables. Parents are influential in the development of dietary habits of young children but often lack the necessary knowledge and skills to promote healthy eating in their children. The aim of this study is to assess the efficacy of a telephone-based intervention for parents to increase the fruit and vegetable consumption of their 3- to 5-year-old children.
Methods/Design: The study, conducted in the Hunter region of New South Wales, Australia, employs a cluster randomised controlled trial design. Two hundred parents from 15 randomly selected preschools will be randomised to receive the intervention, which consists of print resources and four weekly 30-minute telephone support calls delivered by trained telephone interviewers. The calls will assist parents to increase the availability and accessibility of fruit and vegetables in the home, create supportive family eating routines and role-model fruit and vegetable consumption. A further two hundred parents will be randomly allocated to the control group and will receive printed nutrition information only. The primary outcome of the trial will be the change in the child's consumption of fruit and vegetables as measured by the fruit and vegetable subscale of the Children's Dietary Questionnaire. Pre-intervention and post-intervention parent surveys will be administered over the telephone. Baseline surveys will occur one to two
weeks prior to intervention delivery, with follow-up data collection calls occurring two, six, 12 and 18 months following baseline data collection.
Discussion: If effective, this telephone-based intervention may represent a promising public health strategy to increase fruit and vegetable consumption in childhood and reduce the risk of subsequent chronic disease.
Trial registration: Australian Clinical Trials Registry ACTRN12609000820202

Health professionals' and dietetics practitioners' perceived effectiveness of fruit and vegetable parenting practices across six countries

Fruit and vegetable intake may reduce the risk of some chronic diseases. However, many children consume less-than-recommended amounts of fruit and vegetables. Because health professionals and dietetics practitioners often work with parents to increase children's fruit and vegetable intake, assessing their opinions about the effectiveness of parenting practices is an important step in understanding how to promote fruit and vegetable intake among preschool-aged children. Using a cross-sectional design, collaborators from six countries distributed an Internet survey to health and nutrition organization members. A self-selected sample reported their perceptions of the effectiveness of 39 parenting practices intended to promote fruit and vegetable consumption in preschool-aged children from May 18, 2008, to September 16, 2008. A total of 889 participants (55% United States, 22.6% Mexico, 10.9% Australia, 4.4% Spain, 3.3% Chile, 2.2% United Kingdom, and 1.6% other countries) completed the survey. The fruit and vegetable intake–related parenting practices items were categorized into three dimensions (structure, responsiveness, and control) based on a parenting theory conceptual framework and dichotomized as effective/ineffective based on professional perceptions. The theoretically derived factor structures for effective and ineffective parenting practices were evaluated using separate confirmatory factor analyses and demonstrated acceptable fit. Fruit and vegetable intake–related parenting practices that provide external control were perceived as ineffective or counterproductive, whereas fruit and vegetable intake–related parenting practices that provided structure, nondirective control, and were responsive were perceived as effective in getting preschool-aged children to consume fruit and vegetables. Future research needs to develop and validate a parent-reported measure of these fruit and vegetable intake–related parenting practices and to empirically evaluate the effect of parental use of the parenting practices on child fruit and vegetable consumption.

Optimal radio labellings of complete m-ary trees

A radio labelling of a connected graph G is a mapping f : V (G) → {0, 1, 2, ...} such that | f (u) - f (v) | ≥ diam (G) - d (u, v) + 1 for each pair of distinct vertices u, v ∈ V (G), where diam (G) is the diameter of G and d (u, v) the distance between u and v. The span of f is defined as max_u, _{v ∈ V (G)} | f (u) - f (v) |, and the radio number of G is the minimum span of a radio labelling of G. A complete m-ary tree (m ≥ 2) is a rooted tree such that each vertex of degree greater than one has exactly m children and all degree-one vertices are of equal distance (height) to the root. In this paper we determine the radio number of the complete m-ary tree for any m ≥ 2 with any height and construct explicitly an optimal radio labelling.

Australian consumers' views of fruit and vegetable policy options

An Internet survey was conducted among 511 respondents in Victoria, Australia, to ascertain their support for possible government fruit and vegetable promotion policies. The findings suggest that there is a strong and widespread support for policies which encourage country of origin labelling, local and increased production, subsidies, bans and taxes, and communication campaigns. The respondents’ Universalism values (e.g. valuing nature, harmony and beauty) were more pervasive predictors of their opinions than their demographic characteristics. The findings suggest that many Australians hold different views to the prevailing neoliberal views of the political establishment.

The effects of topological inaccuracy in evolutionary trees on the phylogenetic comparative method of independent contrasts

Computer simulations were used to test the effect of increasing phylogenetic topological inaccuracy on the results obtained from correlation tests of independent contrasts. Predictably, increasing the number of disruptions in the tree increases the likelihood of significant error in the r values produced and in the statistical conclusions drawn from the analysis. However, the position of the disruption in the tree is important: Disruptions closer to the tips of the tree have a greater effect than do disruptions that are close to the root of the tree. Independent contrasts derived from inaccurate topologies are more likely to lead to erroneous conclusions when there is a true significant relationship between the variables being tested (i.e., they tend to be conservative). The results also suggest that random phylogenies perform no better than nonphylogenetic analyses and, under certain conditions, may perform even worse than analyses using raw species data. Therefore, the use of random phylogenies is not beneficial in the absence of knowledge of the true phylogeny.

Minimum spanning trees for valley and ridge characterization in digital elevation maps

Texture synthesis employs neighbourhood matching to generate appropriate new content. Terrain synthesis has the added constraint that new content must be geographically plausible. The profile recognition and polygon breaking algorithm (PPA) [Chang et al. 1998] provides a robust mechanism for characterizing terrain as systems of valley and ridge lines in digital elevation maps. We exploit this to create a terrain characterization metric that is robust, efficient to compute and is sensitive to terrain properties.

Terrain regions are characterized as a minimum spanning tree derived from a graph created from the sample points of the elevation map which are encoded as weights in the edges of the graph. This formulation allows us to provide a single consistent feature definition that is sensitive to the pattern of ridges and valleys in the terrain Alternative formulations of these weights provide richer characteristicmeasures and we provide examples of alternate definitions based on curvature and contour measures.

We show that the measure is robust, with a significant portion derived directly from information local to the terrain sample. Global terrain characteristics introduce the issue of over- and underconnected valley/ridge lines when working with sub-regions. This is addressed by providing two graph construction strategies, which respectively provide an upper bound on connectivity as a single spanning tree, and a lower bound as a forest of trees.

Efficient minimum spanning tree algorithms are adapted to the context of terrain data and are shown to provide substantially better performance than previous PPA implementations. In particular, these are able to characterize valley and ridge behaviour at every point even in large elevation maps, providing a measure sensitive to terrain features at all scales.

The resulting graph based formulation provides an efficient and elegant algorithm for characterizing terrain features. The measure can be calculated efficiently, is robust under changes of neighbourhood position, size and resolution and the hybrid measure is sensitive to terrain features both locally and globally.

Involvement of rootstocks and their hydraulic conductance in the drought resistance of grafted rubber trees

Improving drought resistance of rubber trees has become a pressing issue with the extension of rubber plantations and the prevalence of seasonal drought. Root system is vital to water and nutrients uptake of all plants, therefore, rootstocks could play decisive roles in drought resistance of grafted rubber trees on a specific scion clone. To investigate the responses of different clone rootstocks and their grafted trees to water stress and find applicable methods for selecting drought resistant rootstocks, seven related parameters and root hydraulic properties of both seeds originated and grafted saplings of PB86, PR107, RRIM600 and GT1 were measured to assess their drought resistance. It was shown that the rootstock drought resistance and root hydraulic conductance may improve the drought resistance of the grafted rubber trees. Among the four clone rootstocks, GT1, which demonstrated more resistant to drought and higher root hydraulic conductance, was comparatively resistant to drought both for the seed propagation seedlings and grafted saplings. In addition, studies on the grafted saplings with different root hydraulic conductance further validated the possibility of selecting drought resistant rootstocks on the basis of rootstock hydraulic conductance using a high-pressure flow meter.