Sprinkler irrigation of rice fields reduces grain arsenic but enhances cadmium

Previous studies have demonstrated that rice cultivated under flooded conditions has higher concentrations of arsenic (As) but lower cadmium (Cd) compared to rice grown in unsaturated soils. To validate such effects over long terms under Mediterranean conditions a field experiment, conducted over 7 successive years was established in SW Spain. The impact of water management on rice production and grain arsenic (As) and cadmium (Cd) was measured, and As speciation was determined to inform toxicity evaluation. Sprinkler irrigation was compared to traditional flooding.

Both irrigation techniques resulted in similar grain yields (similar to 3000 kg grain ha(-1)). Successive sprinkler irrigation over 7 years decreased grain total As to one-sixth its initial concentration in the flooded system (0.55 to 0.09 mg As kg(-1)), while one cycle of sprinkler irrigation also reduced grain total As by one-third (0.20 mg kg(-1)). Grain inorganic As concentration increased up to 2 folds under flooded conditions compared to sprinkler irrigated fields while organic As was also lower in sprinkler system treatments, but to a lesser extent. This suggests that methylation is favored under water logging. However, sprinkler irrigation increased Cd transfer to grain by a factor of 10, reaching 0.05 mg Cd kg(-1) in 7 years. Sprinlder systems in paddy fields seem particularly suited for Mediterranean climates and are able to mitigate against excessive As accumulation, but our evidence shows that an increased Cd load in rice grain may result.

Revision rules in the theory of evidence

Combination rules proposed so far in the Dempster-Shafer theory of evidence, especially Dempster rule, rely on a basic assumption, that is, pieces of evidence being combined are considered to be on a par, i.e. play the same role. When a source of evidence is less reliable than another, it is possible to discount it and then a symmetric combination operation is still used. In the case of revision, the idea is to let prior knowledge of an agent be altered by some input information. The change problem is thus intrinsically asymmetric. Assuming the input information is reliable, it should be retained whilst the prior information should
be changed minimally to that effect. Although belief revision is already an important subfield of artificial intelligence, so far, it has been little addressed in evidence theory. In this paper, we define the notion of revision for the theory of evidence and propose several different revision rules, called the inner and outer
revisions, and a modified adaptive outer revision, which better corresponds to the idea of revision. Properties of these revision rules are also investigated.

Enabling Others in Social Work: Reflexivity and the Theory of Social Domains

This paper sets out a framework to structure reflexivity in social work practice. Based on the thinking of the sociologist, Derek Layder, it comprises five domains that impact on the individual and social life, namely: (i) psycho-biography – referring to a person’s unique experience throughout the life-course; (ii) situated activity – highlighting the impact of every day social interaction; (iii) social settings – addressing the role of organizations in social life; (iv) culture – covering the influence of attitudes, beliefs, tastes and ideas on symbolic meaning; and (v) politico-economy – alluding to the ramifications of political and economic forces on people’s lives. It is contended that power circulates throughout each domain as an enabling and constraining force. The paper then outlines a process for using the reflexive framework in ‘enabling’ activities such as practice learning, supervision, mentoring and coaching. By applying the framework in these contexts, it is argued that social workers can reflect critically on their role and develop emancipatory forms of practice.

Turbulent amplification of magnetic fields in laboratory laser-produced shock waves

X-ray and radio observations of the supernova remnant Cassiopeia A reveal the presence of magnetic fields about 100 times stronger than those in the surrounding interstellar medium. Field coincident with the outer shock probably arises through a nonlinear feedback process involving cosmic rays. The origin of the large magnetic field in the interior of the remnant is less clear but it is presumably stretched and amplified by turbulent motions. Turbulence may be generated by hydrodynamic instability at the contact discontinuity between the supernova ejecta and the circumstellar gas9. However, optical observations of Cassiopeia A indicate that the ejecta are interacting with a highly inhomogeneous, dense circumstellar cloud bank formed before the supernova explosion. Here we investigate the possibility that turbulent amplification is induced when the outer shock overtakes dense clumps in the ambient medium. We report laboratory experiments that indicate the magnetic field is amplified when the shock interacts with a plastic grid. We show that our experimental results can explain the observed synchrotron emission in the interior of the remnant. The experiment also provides a laboratory example of magnetic field amplification by turbulence in plasmas, a physical process thought to occur in many astrophysical phenomena.

An investigation into the factors influencing tooth brushing behaviour amongst school children living in Northern Ireland: An application of the Theory of Planned Behaviour.

Background: Northern Ireland has the worst oral health in the UK and its children have among the highest levels of tooth decay in Europe (DHSSPS, 2007).
Aim: The aim of this study is to investigate the factors influencing tooth brushing behaviour among Year 6 primary schoolchildren using the Theory of Planned Behaviour (TPB).
Method: Seven semi-structured focus groups involving 56 children were conducted during which children were asked questions about the factors that influence whether or not they brush their teeth. Thematic analysis was used with the purpose of eliciting the belief-based measures for all the TPB constructs.
Results: The findings suggest that children are knowledgeable about their teeth and are aware of the importance of maintaining good oral health; although a number of barriers to consistent tooth brushing exist.
Discussion: The findings will be used to inform stage 2 of the research project; questionnaire development to identify the factors influencing young people’s motivations to improve their tooth brushing behaviour and to assess their relative importance.

Developed turbulence and nonlinear amplification of magnetic fields in laboratory and astrophysical plasmas

The visible matter in the universe is turbulent and magnetized. Turbulence in galaxy clusters is produced by mergers and by jets of the central galaxies and believed responsible for the amplification of magnetic fields. We report on experiments looking at the collision of two laser-produced plasma clouds, mimicking, in the laboratory, a cluster merger event. By measuring the spectrum of the density fluctuations, we infer developed, Kolmogorov-like turbulence. From spectral line broadening, we estimate a level of turbulence consistent with turbulent heating balancing radiative cooling, as it likely does in galaxy clusters. We show that the magnetic field is amplified by turbulent motions, reaching a nonlinear regime that is a precursor to turbulent dynamo. Thus, our experiment provides a promising platform for understanding the structure of turbulence and the amplification of magnetic fields in the universe.

Intentions Toward Physical Activity and Resting Behavior in Pregnant Women: Using the Theory of Planned Behavior Framework in a Cross-Sectional Study

BACKGROUND: Pregnant women are recommended to 1) perform daily moderate-intensity physical activity and 2) limit the amount of sedentary time. Many women do not meet these recommendations. Reduced physical activity and increased sedentary behavior may result from women actively intending to rest during pregnancy. The Theory of Planned Behavior (TPB) has been used to assess attitudes (e.g., positive/negative beliefs), subjective norms (e.g., perception of others' views), perceived behavioral control (PBC) (e.g., self-efficacy), and intention toward exercising while pregnant but has not been applied to aspects pertaining to resting during pregnancy.

METHODS: Pregnant women (n = 345) completed a cross-sectional questionnaire that included two TPB Questionnaires where the target behaviors were 1) being physically active and 2) resting. Bootstrapped paired t tests, ANOVA, and linear hierarchal regression analyses were performed to identify predictors of intentions and whether intentions toward the two behaviors varied at different stages of pregnancy.

RESULTS: As women progressed in their pregnancy, their attitude, PBC, and intention toward being physically active all significantly declined. A positive attitude, subjective norms, and intention toward resting all significantly increased with the advancing trimester. Self-reported health conditions predicted lower intention for physical activity but not for resting.

DISCUSSION: The significantly inverse relationship between physical activity and resting across time suggests that women feel they should focus on one behavior at the expense of the other. Finding that women generally do not perceive these behaviors as mutually compatible has implications in strategizing as to how to encourage women to be active during pregnancy.