Global optimisation of neural networks using a deterministic hybrid approach

Selection of the topology of a neural network and correct parameters for the learning algorithm is a tedious task for designing an optimal artificial neural network, which is smaller, faster and with a better generalization performance. In this paper we introduce a recently developed cutting angle method (a deterministic technique) for global optimization of connection weights. Neural networks are initially trained using the cutting angle method and later the learning is fine-tuned (meta-learning) using conventional gradient descent or other optimization techniques. Experiments were carried out on three time series benchmarks and a comparison was done using evolutionary neural networks. Our preliminary experimentation results show that the proposed deterministic approach could provide near optimal results much faster than the evolutionary approach.

Strategies which aim to positively impact on weight, physical activity, diet and sedentary behaviours in children from zero to five years. A systematic review of the literature

Preventing the development of obesity in children is an international health priority. To assess the effectiveness of interventions designed to prevent obesity, promote healthy eating and/or physical activity and/or to reduce sedentary behaviours in 0–5-year-old children, a systematic review of the literature was performed. Literature searches were limited to articles published between January 1995 and June 2006, printed in English and sampling children aged 0–5-years. Searches excluded literature concerned with breastfeeding, eating disorders, and interventions which were school-based or concerned with obesity treatment. Two reviewers independently extracted data and assessed study strengths and weaknesses. Nine included studies were grouped based on the settings in which they were delivered. Most studies involved multi-approach interventions, were conducted in the USA and varied in study designs and quality. All showed some level of effectiveness on at least one obesity-behaviour in young children. These studies support, at a range of levels, the premise that parents are receptive to and capable of some behavioural changes that may promote healthy weight in their young children. The small quantity of research heralds the need, particularly given the potential for early intervention to have long-lasting impacts on individual and population health, to build in a substantial way upon this evidence base.

How much physical activity is enough to prevent unhealthy weight gain? Outcome of the IASO 1st Stock Conference and consensus statement

A consensus meeting was held in Bangkok, 21–23 May 2002, where experts and young scientists in the field of physical activity, energy expenditure and bodyweight regulation discussed the different aspects of physical activity in relation to the emerging problem of obesity worldwide. The following consensus statement was accepted unanimously.
‘The current physical activity guideline for adults of 30 minutes of moderate
intensity activity daily, preferably all days of the week, is of importance for
limiting health risks for a number of chronic diseases including coronary heart disease and diabetes. However for preventing weight gain or regain this guideline is likely to be insufficient for many individuals in the current environment. There is compelling evidence that prevention of weight regain in formerly obese individuals requires 60–90 minutes of moderate intensity activity or lesser amounts of vigorous intensity activity. Although definitive data are lacking, it seems likely that moderate intensity activity of approximately 45 to 60 minutes per day, or 1.7 PAL (Physical Activity Level) is required to prevent the transition to overweight or obesity. For children, even more activity time is recommended. A good approach for many individuals to obtain the recommended level of physical activity is to reduce sedentary behaviour by incorporating more incidental and leisure-time activity into the daily routine. Political action is imperative
to effect physical and social environmental changes to enable and encourage physical activity. Settings in which these environmental changes can be implemented include the urban and transportation infrastructure, schools, and workplaces.’

The effect of calcium supplementation on bone density in premenarcheal females: a co-twin approach

The age and developmental stage at which calcium supplementation produces the greatest bone effects remain controversial. We tested the hypothesis that calcium supplementation may improve bone accrual in premenarcheal females. Fifty-one pairs of premenarcheal female twins (27 monozygotic and 24 dizygotic; mean ± SD age, 10.3 ± 1.5 yr) participated in a randomized, single-blind, placebo-controlled trial with one twin of each pair receiving a 1200-mg calcium carbonate (Caltrate) supplement. Areal bone mineral density (aBMD) was measured at baseline and 6, 12, 18 and 24 months. There were no within-pair differences in height, weight, or calcium intake at baseline. Calcium supplementation was associated (P < 0.05) with increased aBMD compared with placebo, adjusted for age, height, and weight at the following time points from baseline: total hip, 6 months (1.9%), 12 months (1.6%), and 18 months (2.4%); lumbar spine, 12 months (1.0%); femoral neck, 6 months (1.9%). Adjusted total body bone mineral content was higher in the calcium group at 6 months (2.0%), 12 months (2.5%), 18 months (4.6%), and 24 months (3.7%), respectively (all P < 0.001). Calcium supplementation was effective in increasing aBMD at regional sites over the first 12–18 months, but these gains were not maintained to 24 months.

Economic Evaluation of a Primary Care Trial to Reduce Weight Gain in Overweight/Obese Children: The LEAP Trial

Background:- A common policy response to the childhood obesity epidemic is to recommend that primary care physicians screen for and offer counseling to the overweight/obese. As the literature suggests, this approach may be ineffective; it is important to document the opportunity costs incurred by brief primary care obesity interventions that ultimately may not alter body mass index (BMI) trajectory.

Methods:- Live, Eat and Play (LEAP) was a randomized controlled trial of a brief secondary prevention intervention delivered by family physicians in 2002-2003 that targeted overweight/ mildly obese children aged 5 to 9 years. Primary care utilization was prospectively audited via medical records, and parents reported family resource use by written questionnaire. Outcome measures were BMI (primary) and parent-reported physical activity and dietary habits (secondary) in intervention compared with control children.

Results:- The cost of LEAP per intervention family was AU $4094 greater than for control families, mainly due to increased family resources devoted to child physical activity. Total health sector costs were AU $873 per intervention family and AU $64 per control, a difference of AU $809 {P < .001). At 15 months, intervention children did not differ significantly in adjusted BMI or daily physical activity scores compared with the control group, but dietary habits had improved.

Conclusions:- This brief intervention resulted in higher costs to families and the health care sector, which could have been devoted to other uses that do create benefits to health and/or family well-being. This has implications for countries such as the United States, the United Kingdom, and Australia, whose current guidelines recommend routine surveillance and counseling for high child BMI in the primary care sector.

Outcomes of a group-randomized trial to prevent excess weight gain, reduce screen behaviours and promote physical activity in 10-year-old children : switch-play

Objectives : To evaluate the effectiveness of an intervention to prevent excess weight gain, reduce time spent in screen behaviours, promote participation in and enjoyment of physical activity (PA), and improve fundamental movement skills among children.

Participants : In 2002, 311 children (78% response; 49% boys), average age 10 years 8 months, were recruited from three government schools in low socioeconomic areas of Melbourne, Australia.

Design : Group-randomized controlled trial. Children were randomized by class to one of the four conditions: a behavioural modification group (BM; n=66); a fundamental movement skills group (FMS; n=74); a combined BM/FMS group (BM/FMS; n=93); and a control (usual curriculum) group (n=62). Data were collected at baseline, post intervention, 6- and 12-month follow-up periods.

Results : BMI data were available for 295 children at baseline and 268 at 12-month follow-up. After adjusting for food intake and PA, there was a significant intervention effect from baseline to post intervention on age- and sex-adjusted BMI in the BM/FMS group compared with controls (-1.88 kg m-2, P<0.01), which was maintained at 6- and 12-month follow-up periods (-1.53 kg m-2, P<0.05). Children in the BM/FMS group were less likely than controls to be overweight/obese between baseline and post intervention (adjusted odds ratio (AOR)=0.36, P<0.05); also maintained at 12-month follow-up (AOR=0.38, P<0.05). Compared with controls, FMS group children recorded higher levels and greater enjoyment of PA; and BM children recorded higher levels of PA and TV viewing across all four time points. Gender moderated the intervention effects for participation in and enjoyment of PA, and fundamental movement skills.

Conclusion : This programme represents a promising approach to preventing excess weight gain and promoting participation in and enjoyment of PA. Examination of the mediators of this intervention and further tailoring of the programme to suit both genders is required.

Assessing cost-effectiveness in obesity (ACE-Obesity) : an overview of the ACE approach, economic methods and cost results

Background : The aim of the ACE-Obesity study was to determine the economic credentials of interventions which aim to prevent unhealthy weight gain in children and adolescents. We have reported elsewhere on the modelled effectiveness of 13 obesity prevention interventions in children. In this paper, we report on the cost results and associated methods together with the innovative approach to priority setting that underpins the ACE-Obesity study.

Methods : The Assessing Cost-Effectiveness (ACE) approach combines technical rigour with 'due process' to facilitate evidence-based policy analysis. Technical rigour was achieved through use of standardised evaluation methods, a research team that assembles best available evidence and extensive uncertainty analysis. Cost estimates were based on pathway analysis, with resource usage estimated for the interventions and their 'current practice' comparator, as well as associated cost offsets. Due process was achieved through involvement of stakeholders, consensus decisions informed by briefing papers and 2nd stage filter analysis that captures broader factors that influence policy judgements in addition to cost-effectiveness results. The 2nd stage filters agreed by stakeholders were 'equity', 'strength of the evidence', 'feasibility of implementation', 'acceptability to stakeholders', 'sustainability' and 'potential for side-effects'.

Results : The intervention costs varied considerably, both in absolute terms (from cost saving [6 interventions] to in excess of AUD50m per annum) and when expressed as a 'cost per child' estimate (from <AUD1.0 [reduction of TV advertising of high fat foods/high sugar drinks] to >AUD31,000 [laparoscopic adjustable gastric banding for morbidly obese adolescents]). High costs per child reflected cost structure, target population and/or under-utilisation.

Conclusions : The use of consistent methods enables valid comparison of potential intervention costs and cost-offsets for each of the interventions. ACE-Obesity informs policy-makers about cost-effectiveness, health impact, affordability and 2nd stage filters for important options for preventing unhealthy weight gain in children. In related articles cost-effectiveness results and second stage filter considerations for each intervention assessed will be presented and analysed.

Using a qualitative approach to research to build trust between a non-Aboriginal researcher and Aboriginal participants (Australia)

This article focuses on the qualitative methodologies employed in a research project developed in collaboration with Aboriginal advisors and gaining an in-depth understanding of Aboriginal Victorian peoples' connection to their ancestral lands. It outlines why qualitative methodologies were used and highlights the ethical dimensions of working with Aboriginal Victorian communities. A research partnership was developed between Aboriginal Victorian communities and the non-Aboriginal researcher and this process was emphasised because in the past Australian Indigenous people have been grossly exploited in health research. The methods of semi-structured interviews and focus groups were used to gain a better understanding of this topic. The novel point of this article is that it provides an honest reflection of the benefits and limitations of this qualitative research process from the perspectives of a non-Aboriginal researcher and an Aboriginal participant, when emphasis is placed on a collaborative approach. The paper outlines what a successful qualitative research project looks like in Victorian Aboriginal communities. This can be used as a blueprint not only for working with Victorian Aboriginal communities, who have been marginalised within Australian society, but may also be relevant to other culturally diverse communities throughout the world.

Understanding the correlates of adolescents' TV viewing : a social ecological approach

Objective. To examine associations between social ecological factors and Dutch adolescents’ TV viewing. Design. Cross-sectional examination of predictors of adolescents’ TV viewing.

Participants. A total of 338 adolescents, aged 14 years (55% boys).

Measurements. Adolescents self-reported their age, ethnicity and TV viewing (dichotomized at two hours/day) and responded to items from all three social ecological domains; individual (cognitions based on the Theory of Planned Behaviour and TV viewing habit strength, and other behaviours, such as computer use), social (parental rules about TV viewing and parental TV viewing behavior) and physical environmental factors (TV in bedroom, physical activity equipment available). Parents reported demographic factors (e.g., ethnicity, education level), and their own TV viewing (mins/day); adolescents’ weight status (not overweight vs. overweight/obese) was calculated from objective measures of height and weight. Logistic regression analyses examined associations between socio-ecological factors and adolescents’ TV viewing, and whether associations were moderated by adolescents’ sex, parents’ education and ethnicity.

Results. Compared with others, overweight/obese adolescents (odds ratio (OR)=3.0; p≤0.001), those with high computer use (OR=2.3; p≤0.0001), with high TV viewing habit strength (OR=1.3; p≤0.0001), and those whose parents had high levels of TV viewing (OR=2.4; p≤0.01) were more likely to exceed two hours of TV viewing per day. The association with habit strength was moderated by gender, and the association with parents’ TV viewing was moderated by parents’ education and ethnicity.

Conclusions. Interventions should target parents’ TV viewing behaviors and aim to amend habitual, ‘mindless’ TV viewing among adolescents.

A comparative assessment of austempered ductile iron as a substitute in weight reduction applications

Manufacturing engineering has had to undergo drastic changes in the approach to material selection in order to meet new design challenges. In the automotive industry, researchers in their effort to reduce emissions and satisfy environmental regulations, have shifted their focus to new emerging materials such as high-strength aluminium alloys, metal matrix composites, plastics, polymers and of late, Austempered Ductile Iron (ADI). ADI is a good choice for design where the criterion is high performance at reduced weight and cost. The unique, ausferrite microstructure gives the material desirable material properties and an edge over other materials. A comparative study of ADI in terms of materials properties and machining characteristics with other materials is desirable to highlight the potential of the material. This paper focuses on a comparative assessment of material and machining characteristics of ADI for different applications. The properties under consideration are machinability, weight and cost savings and versatility. ADI has a higher strength-to-weight ratio than aluminium making it a ready alternative for material selection. In terms of machinability, there are some problems associated with machining of ADI due to its work hardening nature. This paper attempts to identify the possible potential applications of ADI, by critically reviewing specific applications such as machinability, overall economics and service.

Reducing unhealthy weight gain in Fijian adolescents : results of the Healthy Youth Healthy Communities study

Obesity is a significant problem among adolescents in Pacific populations. This paper reports on the outcomes of a 3-year obesity prevention study, Healthy Youth Healthy Communities, which was part of the Pacific Obesity Prevention in Communities project, undertaken with Fijian adolescents. The intervention was developed with schools and comprised social marketing, nutrition and physical activity initiatives and capacity building designed to reduce unhealthy weight, and the individual exposure period was just over 2-year duration. The evaluation incorporated a quasi-experimental, longitudinal design in seven intervention secondary schools near Suva (n = 874) and a matched sample of 11 comparison secondary schools from western Viti Levu (n = 2,062). There were significant differences between groups at baseline; the intervention group was shorter, weighed less, had a higher proportion of underweight and lower proportion of overweight, and better quality of life (Pediatric Quality of Life Inventory only). At follow-up, the intervention group had lower percentage body fat (-1.17) but also a lower increase in quality of life (Assessment of Quality of Life instrument: -0.02; Pediatric Quality of Life Inventory: -1.94) than the comparison group. There were no other differences in anthropometry, and behaviours’ changes showed a mixed pattern. In conclusion, this school-based health promotion programme lowered percentage body fat but did not reduce unhealthy weight gain or influence most obesity-promoting behaviours among Fijian adolescents. Despite growing evidence supporting the efficacy of community-based approaches to reduce obesity among children of European descent, findings from this study failed to demonstrate the efficacy of a community capacity-building approach among an adolescent sample drawn from a different sociocultural, economic and geographical context. Additional ‘top–down’ or other innovative approaches may be needed to reduce adolescent obesity in the Pacific.

Living to tell the tale : survival and connection

Memories too sharp for public handling most often stay in our private worlds where we all live, at some point or other, with the weight of regret, or sadness of things lost. The idea of living to tell the tale becomes in itself the story, and we keep counsel with that idea in early morning dreams, or late night fears. For most of us, that is as far as our story goes. Some women, however, move beyond that instinctive silence born of trauma. When the story they have to tell is also a trauma of nationality, of intercultural connection, and of women’s shared sense of survival, it can be tough reading. Judith McNeil’s memoir, The Girl With the Cardboard Port was set down, like this, in front of me.

Defining plant resistance to Phytophthora cinnamomi : a standardized approach to assessment

Phytophthora cinnamomi is a soil-borne plant pathogen that causes devastating disease in agricultural and natural systems worldwide. While a small number of species survive infection by the pathogen without producing disease symptoms, the nature of resistance, especially under controlled conditions, remains poorly understood. At present, there are no standardized criteria by which resistance or susceptibility to P. cinnamomi can be assessed, and we have used five parameters consisting of plant fresh weight, root growth, lesion length, relative chlorophyll content of leaves and pathogen colonization of roots to analyse responses to the pathogen. The parameters were tested using two plant species, Zea mays and Lupinus angustifolius, through a time course study of the interactions and resistance and susceptibility defined 7days after inoculation. A scoring system was devised to enable differentiation of these responses. In the resistant interaction with Z. mays, there was no significant difference in fresh weight, root length and relative chlorophyll content in inoculated compared with control plants. Both lesion size and pathogen colonization of root tissues were limited to the site of inoculation. Following inoculation L. angustifolius showed a significant reduction in plant fresh weight and relative leaf chlorophyll content, cessation of root growth and increased lesion lengths and pathogen colonization. We propose that this technique provides a standardized method for plant-P. cinnamomi interactions that could be widely used to differentiate resistant from susceptible species.

A systems approach to shape and topology optimisation of mechanical structures

Optimisation techniques have become more and more important as the possibility of simulating complex mechanical structures has become a reality. A common tool in the layout design of structural parts is the topology optimisation method, which finds an optimum material distribution within a given geometrical design space to best meet loading conditions and constraints. Another important method is shape optimisation, which optimises weight given parametric geometric constraints. In the case of complex shaped parts or elaborate assemblies, for example automobile body structures, shape optimisation is still hard to do; mainly due to the difficulty in translating shape design parameters into meaningful analysis models. Tools like the parametric geometry package SFE CONCEPT are designed to mitigate these issues. Nevertheless, shape methods usually cannot suggest new load path configurations, while topology methods are often confined to single parts. To overcome these limitations the authors have developed a method that combines both approaches into an Integral Shape/Topology Method (IST) that is capable of finding new optimal solutions. This is achieved by an automated optimisation loop and can be applied for both thin walled structures as well as solid 3D geometries. When optimising structures by applying IST, global optimum solutions can be determined that may not be obtained with isolated shape- or topology-optimisation methods.

A tabular approach to titration calculations

Titrations are common laboratory exercises in high school and university chemistry courses, because they are easy, relatively inexpensive, and they illustrate a number of fundamental chemical principles. While students have little difficulty with calculations involving a single titration step, there is a significant leap in conceptual difficulty when “scaling-up” to more involved titration calculations with two or more steps. Currently, there is no alternative approach for students who are unable to follow the standard textbook method for titration calculations. This paper presents a new method of setting out the titration calculations, which helps these weaker students to better organize the data. The connection between the new method and current models of learning is discussed to explain why the tabular approach is successful for students who have difficulty following the standard textbook method.