3D-visualization and analysis of macro- and meso-porosity of the upper horizons of a sodic, texture-contrast soil

The definitive version is available at www.blackwell-synergy.comThe lower E and upper B horizons of sodic, texture-contrast soils are a formidable barrier to most annual and many perennial crops. The research presented here is part of a wider study into the nature of subsoil constraints to root exploration. The aim of this study was to characterize in three dimensions the macro- and meso-porosity across the E horizon–Btn horizon interface of a sodic, texture-contrast soil using X-ray computed tomography (CT). Intact soil cores of 50-cm length and 15-cm diameter were scanned with a medical CT X-ray machine. The pore volume reconstructed from these scans had a resolution of 0.3 × 0.3 × 0.4 cm (in the x, y, z dimensions, respectively). This resolution allowed visualization and quantification of the macroporosity of the intact cores. Undisturbed samples of 1.5-cm diameter and 4-cm length were carefully excised from the interface and scanned with micro-CT X-ray equipment. The reconstructed pore volumes had an isotropic resolution of 19 μm that allowed analysis of the mesoporosity just on the boundary between the E and Btn horizons. Mesoporosity decreased across the interface and increased lower in the Btn horizon. The distribution of the pores at the macro- and meso-scales showed the importance of the smaller pores in the A and E horizons, whereas most of the porosity in the Btn horizon was attributed to the larger pores. Pores in this sodic, texture-contrast soil were not distributed homogeneously at either the macro- or meso-scale. A greater proportion of the pores in the E–B interface were horizontal than in the upper A1, upper E and lower Btn horizons. Some ‘coiling’ of the pores was also apparent in the interface. The shape of some pores (long tubular pores) suggested formation by roots as they drilled through the soil. The orientation of these pores was a function of physical (and possibly chemical) impedance at the interface.L. Jassogne, A. McNeill & D. Chittleboroug

A method for determination of retention of silver and cerium oxide manufactured nanoparticles in soils

Methods to study the retention of manufactured nanoparticles (MNP) are lacking for soils that are likely to be increasingly exposed to MNP. In this study we present, for the first time, a method to determine retention values (Kr) of Ag and CeO2 MNP, that can be ranked among solid–liquid partitioning (Kd) values of bulk (micrometre-sized) forms, soluble salts and other possible contaminants of soils. After method optimisation, suspensions containing 1.24 mg kg–1 Ag as Ag MNP and 1.30 mg kg–1 Ce as CeO2 MNP were added to five soils. More than 7% of Ag MNP occurred as soluble AgI after 24 h and the range of Kr values of Ag MNP (77–2165 L kg–1) and CeO2 MNP (1.1–2828 L kg–1) contrasted with Kd values of soluble AgI, CeIII and CeIV salts and bulk Ag and CeO2 powders in different soils.Geert Cornelis, Jason K. Kirby, Douglas Beak, David Chittleborough and Mike J. McLaughli

Effect of intervention aimed at increasing physical activity, reducing sedentary behaviour, and increasing fruit and vegetable consumption in children: Active for Life Year 5 (AFLY5) school based cluster randomised controlled trial

Objective To investigate the effectiveness of a school based intervention to increase physical activity, reduce sedentary behaviour, and increase fruit and vegetable consumption in children. Design Cluster randomised controlled trial. Setting 60 primary schools in the south west of England. Participants Primary school children who were in school year 4 (age 8-9 years) at recruitment and baseline assessment, in year 5 during the intervention, and at the end of year 5 (age 9-10) at follow-up assessment. Intervention The Active for Life Year 5 (AFLY5) intervention consisted of teacher training, provision of lesson and child-parent interactive homework plans, all materials required for lessons and homework, and written materials for school newsletters and parents. The intervention was delivered when children were in school year 5 (age 9-10 years). Schools allocated to control received standard teaching. Main outcome measures The pre-specified primary outcomes were accelerometer assessed minutes of moderate to vigorous physical activity per day, accelerometer assessed minutes of sedentary behaviour per day, and reported daily consumption of servings of fruit and vegetables. Results 60 schools with more than 2221 children were recruited; valid data were available for fruit and vegetable consumption for 2121 children, for accelerometer assessed physical activity and sedentary behaviour for 1252 children, and for secondary outcomes for between 1825 and 2212 children for the main analyses. None of the three primary outcomes differed between children in schools allocated to the AFLY5 intervention and those allocated to the control group. The difference in means comparing the intervention group with the control group was -1.35 (95% confidence interval -5.29 to 2.59) minutes per day for moderate to vigorous physical activity, -0.11 (-9.71 to 9.49) minutes per day for sedentary behaviour, and 0.08 (-0.12 to 0.28) servings per day for fruit and vegetable consumption. The intervention was effective for three out of nine of the secondary outcomes after multiple testing was taken into account: self reported time spent in screen viewing at the weekend (-21 (-37 to -4) minutes per day), self reported servings of snacks per day (-0.22 (-0.38 to -0.05)), and servings of high energy drinks per day (-0.26 (-0.43 to -0.10)) were all reduced. Results from a series of sensitivity analyses testing different assumptions about missing data and from per protocol analyses produced similar results. Conclusion The findings suggest that the AFLY5 school based intervention is not effective at increasing levels of physical activity, decreasing sedentary behaviour, and increasing fruit and vegetable consumption in primary school children. Change in these activities may require more intensive behavioural interventions with children or upstream interventions at the family and societal level, as well as at the school environment level. These findings have relevance for researchers, policy makers, public health practitioners, and doctors who are involved in health promotion, policy making, and commissioning services

Non-response to a life course socioeconomic position indicator in surveillance: comparison of telephone and face-to-face modes

© 2008 Chittleborough et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background Measurement of socioeconomic position (SEP) over the life course in population health surveillance systems is important for examining differences in health and illness between different population groups and for monitoring the impact of policies and interventions aimed at reducing health inequities and intergenerational disadvantage over time. While face-to-face surveys are considered the gold standard of interviewing techniques, computer-assisted telephone interviewing is often preferred for cost and convenience. This study compared recall of parents' highest level of education in telephone and face-to-face surveys. Methods Questions about father's and mother's highest education level were included in two representative population health surveys of South Australians aged 18 years and over in Spring 2004. A random sample selected from the electronic white pages (EWP) responded to a computer-assisted telephone interview (n = 2999), and a multistage clustered area sample responded to a face-to-face interview (n = 2893). A subsample of respondents in the face-to-face sample who owned a telephone that was listed in the EWP (n = 2206) was also compared to the telephone interview sample. Results The proportion of respondents who provided information about their father's and mother's highest education level was significantly higher in the face-to-face interview (86.3% and 87.8%, respectively) than in the telephone interview (80.4% and 79.9%, respectively). Recall was also significantly higher in the subsample of respondents in the face-to-face interview who had a telephone that was listed in the EWP. Those with missing data for parents' education were more likely to be socioeconomically disadvantaged regardless of the survey mode. Conclusion While face-to-face interviewing obtained higher item response rates for questions about parents' education, survey mode did not appear to influence the factors associated with having missing data on father's or mother's highest education level

The significance and lag-time of deep through flow: an example from a small, ephemeral catchment with contrasting soil types in the Adelaide Hills, South Australia

The importance of deep throughflow in a small (3.4 km2) ephemeral catchment in the Adelaide Hills of South Australia was investigated by detailed hydrochemical analysis of soil water and stream flow during autumn and early winter rains. In this Mediterranean climate with strong summer moisture deficits, several significant rainfalls are required to generate soil throughflow and stream flow (in ephemeral streams). During Autumn 2007, a large (127 mm) drought-breaking rain occurred in April followed by significant May rains; most of this precipitation occurred prior to the initiation of stream flow in late May. These early events, especially the 127 mm event, had low (depleted) stable water isotope values compared with both later rains and average winter precipitation. Thus, this large depleted early rain event provided an excellent natural tracer. During the June and July rainfall events, daily stream and soil water samples were collected and analysed. Results from major and trace elements, water isotopes (δ18O, δD), and dissolved organic carbon analysis clearly demonstrate that a large component of this early April and May rain was stored and later pushed out of deep soil or regolith zones. This pre-event water was identified in the stream as well as identified in deeper soil horizons due to its different isotopic signature which contrasted sharply with the June–July event water. Based on this data, the regolith and throughflow system for this catchment has been re-thought. The catchment area consists of about half sandy and half clayey soils. Regolith flow is now thought to be dominated by the sandy soil system not the clayey soil system. The clayey duplex soils had rapid response to rain events and saturation excess overland flow. The sandy soils had delayed soil throughflow and infiltration excess overland flow. A pulse of macropore throughflow was observed in the sandy soils three days after the rainfall event largely ended. The macropore water was a mixture of pre-event and event water, demonstrating the lag-time and mixing of the water masses in the sandy soil system. By contrast, the clayey soil horizons were dominated by pre-event water to a much lesser degree, demonstrating the quicker response and shallow flow through of the clayey soil system. Thus, the sandy terrain has a greater vadose zone storage and greater lag time of through-flow than the clayey terrain.E. Bestland, S. Milgate, D. Chittleborough, J. VanLeeuwen, M. Pichler and L. Solonink

Cohort profile: the avon longitudinal study of parents and children: ALSPAC mothers cohort

The Avon Longitudinal Study of Children and Parents (ALSPAC) was established to understand how genetic and environmental characteristics influence health and development in parents and children. All pregnant women resident in a defined area in the South West of England, with an expected date of delivery between 1st April 1991 and 31st December 1992, were eligible and 13 761 women (contributing 13 867 pregnancies) were recruited. These women have been followed over the last 19–22 years and have completed up to 20 questionnaires, have had detailed data abstracted from their medical records and have information on any cancer diagnoses and deaths through record linkage. A follow-up assessment was completed 17–18 years postnatal at which anthropometry, blood pressure, fat, lean and bone mass and carotid intima media thickness were assessed, and a fasting blood sample taken. The second follow-up clinic, which additionally measures cognitive function, physical capability, physical activity (with accelerometer) and wrist bone architecture, is underway and two further assessments with similar measurements will take place over the next 5 years. There is a detailed biobank that includes DNA, with genome-wide data available on >10 000, stored serum and plasma taken repeatedly since pregnancy and other samples; a wide range of data on completed biospecimen assays are available. Details of how to access these data are provided in this cohort profile

Patterns of aeolian deposition in subtropical Australia through the last glacial and deglacial periods

Published online by Cambridge University Press: 08 February 2021Debate about the nature of climate and the magnitude of ecological change across Australia during the last glacial maximum (LGM; 26.5–19 ka) persists despite considerable research into the late Pleistocene. This is partly due to a lack of detailed paleoenvironmental records and reliable chronological frameworks. Geochemical and geochronological analyses of a 60 ka sedimentary record from Brown Lake, subtropical Queensland, are presented and considered in the context of climate-controlled environmental change. Optically stimulated luminescence dating of dune crests adjacent to prominent wetlands across North Stradbroke Island (Minjerribah) returned a mean age of 119.9 ± 10.6 ka; indicating relative dune stability soon after formation in Marine Isotope Stage 5. Synthesis of wetland sediment geochemistry across the island was used to identify dust accumulation and applied as an aridification proxy over the last glacial-interglacial cycle. A positive trend of dust deposition from ca. 50 ka was found with highest influx occurring leading into the LGM. Complexities of comparing sedimentary records and the need for robust age models are highlighted with local variation influencing the accumulation of exogenic material. An inter-site comparison suggests enhanced moisture stress regionally during the last glaciation and throughout the LGM, returning to a more positive moisture balance ca. 8 ka.Richard J. Lewis, John Tibby, Lee J. Arnold, Patricia Gadd, Geraldine Jacobsen, Cameron Bar

The north west Adelaide health study: detailed methods and baseline segmentation of a cohort for selected chronic diseases

The North West Adelaide Health Study is a population-based biomedical cohort study investigating the prevalence of a number of chronic conditions and health-related risk factors along a continuum. This methodology may assist with evidence-based decisions for health policy makers and planners, and inform health professionals who are involved in chronic disease prevention and management, by providing a better description of people at risk of developing or already diagnosed with selected chronic conditions for more accurate targeting groups for health gain and improved health outcomes. Longitudinal data will provide information on progression of chronic conditions and allow description of those who move forward and back along the continuum over time. Detailed methods are provided regarding the random recruitment and examination of a representative sample of participants (n = 4060), including the rationale for various processes and valuable lessons learnt. Self-reported and biomedical data were obtained on risk factors (smoking, alcohol consumption, physical activity, family history, body mass index, blood pressure, cholesterol) and chronic conditions (asthma, chronic obstructive pulmonary disease, diabetes) to classify participants according to their status along a continuum. Segmenting this population sample along a continuum showed that 71.5% had at least one risk factor for developing asthma, chronic obstructive pulmonary disease or diabetes. Almost one-fifth (18.8%) had been previously diagnosed with at least one of these chronic conditions, and an additional 3.9% had at least one of these conditions but had not been diagnosed. This paper provides a novel opportunity to examine how a cohort study was born. It presents detailed methodology behind the selection, recruitment and examination of a cohort and how participants with selected chronic conditions can be segmented along a continuum that may assist with health promotion and health services planning.Janet F Grant, Catherine R Chittleborough, Anne W Taylor, Eleonora Dal Grande, David H Wilson, Patrick J Phillips, Robert J Adams, Julianne Cheek, Kay Price, Tiffany Gill and Richard E Ruffi