Emergent magnetic order and correlated disorder in formate metal-organic frameworks.

Magnetic materials with strong local interactions but lacking long-range order have long been a curiosity of physicists. Probing their magnetic interactions is crucial for understanding the unique properties they can exhibit. Metal-organic frameworks have recently gathered more attention as they can produce more exotic structures, allowing for controlled design of magnetic properties not found in conventional metal-oxide materials. Historically, magnetic diffuse scattering in such materials has been overlooked but has attracted greater attention recently, with advances in techniques. In this study, we investigate the magnetic structure of metal-organic formate frameworks, using heat capacity, magnetic susceptibility and neutron diffraction. In Tb(DCO2)3, we observe emergent magnetic order at temperatures below 1.2 K, consisting of two k-vectors. Ho(DCO2)3 shows diffuse scattering above 1.6 K, consistent with ferromagnetic chains packed in a frustrated antiferromagnetic triangular lattice, also observed in Tb(DCO2)3 above 1.2 K. The other lanthanides show no short- or long-range order down to 1.6 K. The results suggest an Ising-like one-dimensional magnetic order associated with frustration is responsible for the magnetocaloric properties, of some members in this family, improving at higher temperatures. This article is part of the theme issue 'Mineralomimesis: natural and synthetic frameworks in science and technology'.

A qualitative investigation into the levers and barriers to weight loss in children: opinions of obese children.

BACKGROUND: The alarming increase in the worldwide prevalence of childhood obesity is now recognised as a major public health concern. Failure to isolate and understand the external and internal factors contributing to successful weight loss may well be contributing to the ineffectiveness of current treatment interventions. AIM: To identify the physical and psychological levers and barriers to weight loss experienced by obese children using qualitative techniques. METHODS: 20 participants were randomly selected from a population of clinically obese children (7-15 years old) attending a weight-loss clinic for >3 months. The children expressed their opinions in a series of interviews and focus group sessions. Data were recorded, semitranscribed and analysed using the thematic framework analysis technique and behavioural-change models. RESULTS: Children described the humiliation of social torment and exclusion as the main reasons for wanting to lose weight, although initiation of behavioural change required the active intervention of a role model. The continuation of action was deemed improbable without continual emotional support offered at an individual level. Behavioural sacrifice, delayed parental recognition and previous negative experiences of weight loss were recognised as barriers to action. Participants identified shortcomings in their own physical abilities, the extended time period required to lose weight and external restrictions beyond their control as barriers to maintaining behavioural change. DISCUSSION: This study identifies the important levers and barriers experienced by obese children in their attempt to lose weight. Dealing with these levers and barriers while acknowledging the complex interplay of social and emotional factors unique to the individual may well promote successful weight control.

WATCH IT: a community based programme for obese children and adolescents.

BACKGROUND: The WATCH IT programme was developed to address the needs of obese children from disadvantaged communities in Leeds and has been running since January 2004. Results of the pilot phase, prior to a randomised controlled trial, are presented. METHODS: A process evaluation to assess success of implementation was conducted in December 2004. User views (parent and child) were obtained by semi-structured interviews and focus groups. Change in BMI SD score was calculated for children attending between January 2004 and November 2005. RESULTS: A total of 94 children (49 girls, 45 boys), mean age (SD) 12.2 (2.0) years attended. They were moderately to severely obese (mean BMI SDS 3.09 (0.45), with low quality of life and self-image scores. There was a significant reduction in overweight at 6 months (DeltaBMI SD -0.07), especially for teenagers (DeltaBMI SD -0.13) and girls (DeltaBMI SD -0.07). The programme was successfully implemented. By December 2004 mean attendance was 2.1 (0.7) clinics per month, and sports sessions 3.3 (1.7) sessions per month. Fourteen children dropped out and non-attendance was low (only 7.5% sessions missed in 12 months). Qualitative research indicated significant appreciation of the service, with reported increase in self-confidence and friendships, and reduction in self-harm. CONCLUSION: WATCH IT offers a model for a community based service for obese children. The programme suggests that effective care can be delivered by health trainers supervised by health professionals, and so potentially provides a cost effective programme within children's communities. These findings are encouraging, and need to be substantiated by extension to other locations and evaluation by randomised controlled trial.

Randomised controlled trial of primary school based intervention to reduce risk factors for obesity.

OBJECTIVE: To assess if a school based intervention was effective in reducing risk factors for obesity. DESIGN: Group randomised controlled trial. SETTING: 10 primary schools in Leeds. PARTICIPANTS: 634 children aged 7-11 years. INTERVENTION: Teacher training, modification of school meals, and the development of school action plans targeting the curriculum, physical education, tuck shops, and playground activities. MAIN OUTCOME MEASURES: Body mass index, diet, physical activity, and psychological state. RESULTS: Vegetable consumption by 24 hour recall was higher in children in the intervention group than the control group (weighted mean difference 0.3 portions/day, 95% confidence interval 0.2 to 0.4), representing a difference equivalent to 50% of baseline consumption. Fruit consumption was lower in obese children in the intervention group (-1.0, -1.8 to -0.2) than those in the control group. The three day diary showed higher consumption of high sugar foods (0.8, 0.1 to 1.6)) among overweight children in the intervention group than the control group. Sedentary behaviour was higher in overweight children in the intervention group (0.3, 0.0 to 0.7). Global self worth was higher in obese children in the intervention group (0.3, 0.3 to 0.6). There was no difference in body mass index, other psychological measures, or dieting behaviour between the groups. Focus groups indicated higher levels of self reported behaviour change, understanding, and knowledge among children who had received the intervention. CONCLUSION: Although it was successful in producing changes at school level, the programme had little effect on children's behaviour other than a modest increase in consumption of vegetables.

Evaluation of implementation and effect of primary school based intervention to reduce risk factors for obesity.

OBJECTIVES: To implement a school based health promotion programme aimed at reducing risk factors for obesity and to evaluate the implementation process and its effect on the school. DESIGN: Data from 10 schools participating in a group randomised controlled crossover trial were pooled and analysed. SETTING: 10 primary schools in Leeds. PARTICIPANTS: 634 children (350 boys and 284 girls) aged 7-11 years. MAIN OUTCOME MEASURES: Response rates to questionnaires, teachers' evaluation of training and input, success of school action plans, content of school meals, and children's knowledge of healthy living and self reported behaviour. RESULTS: All 10 schools participated throughout the study. 76 (89%) of the action points determined by schools in their school action plans were achieved, along with positive changes in school meals. A high level of support for nutrition education and promotion of physical activity was expressed by both teachers and parents. 410 (64%) parents responded to the questionnaire concerning changes they would like to see implemented in school. 19 out of 20 teachers attended the training, and all reported satisfaction with the training, resources, and support. Intervention children showed a higher score for knowledge, attitudes, and self reported behaviour for healthy eating and physical activity. CONCLUSION: This programme was successfully implemented and produced changes at school level that tackled risk factors for obesity.

'Fatalism', accident causation and prevention: issues for health promotion from an exploratory study in a Yoruba town, Nigeria.

As countries experience the 'epidemiological transition' with a relative decline in infectious diseases, accident rates tend to increase, particularly road traffic accidents. The health promotion interventions intended to prevent or minimize the consequences of accidents have been developed in predominantly Western, industrialized countries. Although some of these solutions have been applied with success to less developed countries, there are also good reasons why such solutions are ineffective when tried in a different context. Health promotion as developed in the West has a particular ideological bias, being framed within a secular, individualist and rationalist culture. Different cosmologies exist outside this culture, often described as 'fatalist' by Western commentators and as obstructing change. Changing these cosmologies or worldviews may not fit with the ethic of paying due respect to the cultural traditions of the 'target group'. Health promotion is therefore faced with a dilemma. In addition to different worldviews, the different levels of development also mean that solutions formulated in richer countries do not suit poorer countries. This paper uses a small exploratory study in a Yoruba town in Nigeria to examine these points. Interviews with key informants were held in March 1994 in Igbo-Ora and data were extracted from hospital records. Levels of accidents from available records are noted and people's ideas about accident prevention are discussed. Recommendations as to the way forward are then proposed.

Diatom motility: the search for independent replication of biological effects of extremely low-frequency electromagnetic fields.

PURPOSE: To investigate the hypothesis that exposure to a certain combination of static and time-varying electromagnetic fields (EMF) results in an increase in motility of the marine diatom Amphora coffeaeformis. MATERIALS AND METHODS: Diatom motility on agar was positively correlated with calcium ion (Ca2+) concentration. In previous experiments extremely low frequency EMF (16 Hz) had the greatest effect on diatoms at suboptimal for movement Ca2+ concentrations. To ensure that the required suboptimal Ca2+ concentration and resultant cell motility were found, a number of low concentrations of Ca2+ were experimentally tested. The EMF exposure conditions were those at the calculated calcium resonances (B(V)=0 microT; B(H)=20.9 microT; B(AC)=41.8 microT peak-peak 16 Hz) previously found to cause enhanced motility. Diatom movement on agar plates under EMF and control exposures was recorded. RESULTS: There was no significant difference in cell motility between control and EMF-exposed diatoms at each Ca2+ concentration tested. CONCLUSIONS: The study indicates that low-frequency EMF set at resonance conditions did not cause an increase in motility of the diatoms.

Diatom motility and low frequency electromagnetic fields--a new technique in the search for independent replication of results.

The hypothesis that exposure to a certain combination of static and alternating electromagnetic fields (EMFs) results in an increase in motility of the marine diatom Amphora coffeaeformis was tested. Diatom motility in three strains of A. coffeaeformis was positively correlated with extracellular calcium ion (Ca2+) concentration. The test apparatus consisted of two pairs of Helmholtz coils supported around the stage of a microscope linked to a video recorder and monitor. This system allowed real-time in vivo recordings of diatom speed under EMF and control exposures. The EMFs were calculated at calcium resonance values, previously found to cause enhanced motility. Computerised image analysis was used to calculate the distance moved by individual diatoms in 2-min periods before, during and after EMF or sham-EMF (control) exposure. The addition of EMF caused no significant increase in diatom motility. The results are discussed in relation to the use of diatom motility to measure EMF exposure effects.

Keeping Children Safe: The Effect on Parents' Daily Lives and Psychological Well-being.

The aim of this article is to present qualitative data from a study of mothers on a housing estate in Leeds, UK, enabling them to voice their concerns about child safety. The estate contains many environmental hazards, from traffic, 'drugusers', 'strangers' and litter. A high profile given to the vulnerability of children in public places has resulted in parents becoming ever vigilant and subjecting children to increased surveillance, in the face of a lack of environmental measures which would support their efforts to keep children safe. There are costs to parents in time and activities foregone. Moreover, the emphasis on the key role of parents in child safety and the perception of increasing hazards to children is affecting parents' psychological well-being. The article attempts to place parents' concerns within a social context which may begin to explain parental behaviour and anxieties.

Evaluation of the Effects of Extremely Low Frequency Electromagnetic Fields on Movement in the Marine Diatom Amphora coffeaeformis.

Published work has shown that population motility in the marine diatom Amphora coffeaeformis can be influenced by externally applied electromagnetic fields (EMFs). Here we report attempts to repeat these experiments, which have been proposed as a model for assessing the effects of EMFs on biological systems. Susceptibility to EMFs was tested using five strains of diatoms on agar plates at a very broad range of field conditions, but no effect on population motility was demonstrated. Exposure period to the EMFs, cell density, and position in the cell cycle had no effect on EMF susceptibility, and the direction and distance moved by the diatoms were not affected by EMFs. When tested after at least a month of preincubation at 20 {mu}T, diatoms of strains #2038, IIIB, and IIIF did show an EMF-induced increase in population motility over control cells (up to ~20%) at conditions predicted by the "ion cyclotron resonance" model, but this effect was ephemeral. Later, IIIB showed a similar increase that was abolished when (1) non-pre-incubated cells were used, (2) the EMF-producing coils were not energized, and (3) even harmonics were used. On observing the response of diatoms to EMFs in real time, a significant increase (~2-fold) in diatom speed over control cells was evident at "ion cyclotron resonance" conditions, using strain #2038 (pre-incubated at 20 {mu}T). The effect was abolished at an even harmonic. We conclude that EMFs can modulate diatom motility, but that the system is, as yet, not consistently reproducible.

Healthy eating in schools and "eating disorders"--are "healthy eating" messages part of the problem or part of the solution?

This is a discussion paper which raises questions about the possible links between health education which exhorts young people to watch their weight and eat a healthy diet and the increase in disturbed eating patterns and the desire to be thin, particularly amongst girls. It doesn't especially offer "answers", but suggests that research would be needed to investigate whether such a link exists. The paper derives from my own concerns as a health educator about how health messages are received. The background to concern about weight among young people is described, and some initiatives in schools which may help are discussed.

Oral warty dyskeratoma: literature review and report of case.

A case of intraoral warty dyskeratoma has been presented. Etiologic theories, diagnosis, and diagnostic techniques have been presented.