Self-regulation of driving and its relationship to driving ability among older adults

Although it is known that older drivers limit their driving, it is not known whether this self-regulation is related to actual driving ability. A sample of 104 older drivers, aged between 60 and 92, completed a questionnaire about driving habits and attitudes. Ninety of these drivers also completed a structured on-road driving test. A measure of self-regulation was derived from drivers’ self-reported avoidance of difficult driving situations. The on-road driving test involved a standard assessment used to determine fitness to drive. Of the 90 participants who completed the driving assessment, 68 passed the test, eight passed but were recommended to have driving lessons and 14 failed. Driving test scores for the study were based on the number of errors committed in the driving tests, with weightings given according to the seriousness of the errors. The most commonly avoided difficult driving situations were parallel parking and driving at night in the rain, while the least avoided situation was driving alone. Poorer performance on the driving test was not strongly related to overall avoidance of difficult driving situations. Stronger relationships were found between driving ability and avoidance of specific difficult driving situations. These specific driving situations were the ones in which the drivers had low confidence and that the drivers were most able to avoid if they wished to. These results may reflect a tendency for those with poorer driving ability to lose confidence in their driving, and begin to avoid difficult driving situations. However, there are a number of situations that drivers find difficult to avoid.M.R.J. Baldock, J.L. Mathias, A.J. McLean, A. Bernd

Continental-Scale Soil Organic Carbon Composition and Vulnerability Regulated by Regional Soil and Environmental Controls

Processes that control soil organic carbon (C) composition and dynamics over large scales are not well understood. Thus, our understanding of C cycling is incomplete, making it difficult to predict C gains and losses due to changes in climate, land use and management. In this paper, we show that controls on the composition of organic C, the particulate, humus (or mineral associated) and resistant fractions, and the potential vulnerability of C to decomposition across Australia are distinct, scale-dependent and variable

Quantitative evaluation of polymer gel dosimeters by broadband ultrasound attenuation

Ultrasound has been examined previously as an alternative readout method for irradiated polymer gel dosimeters, with authors reporting varying dose response to ultrasound transmission measurements. In this current work we extend previous work to measure the broadband ultrasound attenuation (BUA) response of irradiated PAGAT gel dosimeters, using a novel ultrasound computed tomography system

Reconstructing 3D x-ray CT images of polymer gel dosimeters using the zero-scan method

In this study x-ray CT has been used to produce a 3D image of an irradiated PAGAT gel sample, with noise-reduction achieved using the ‘zero-scan’ method. The gel was repeatedly CT scanned and a linear fit to the varying Hounsfield unit of each pixel in the 3D volume was evaluated across the repeated scans, allowing a zero-scan extrapolation of the image to be obtained. To minimise heating of the CT scanner’s x-ray tube, this study used a large slice thickness (1 cm), to provide image slices across the irradiated region of the gel, and a relatively small number of CT scans (63), to extrapolate the zero-scan image. The resulting set of transverse images shows reduced noise compared to images from the initial CT scan of the gel, without being degraded by the additional radiation dose delivered to the gel during the repeated scanning. The full, 3D image of the gel has a low spatial resolution in the longitudinal direction, due to the selected scan parameters. Nonetheless, important features of the dose distribution are apparent in the 3D x-ray CT scan of the gel. The results of this study demonstrate that the zero-scan extrapolation method can be applied to the reconstruction of multiple x-ray CT slices, to provide useful 2D and 3D images of irradiated dosimetry gels

Self-regulation of driving and older drivers' functional abilities

A sample of 90 adults aged between 60 and 91 completed a questionnaire about their driving behaviour, a battery of functional tests, and a structured on-road test. The section of the questionnaire featuring items about avoidance of difficult driving situations was used as an index of self-regulation of driving behaviour. The functional test battery consisted of mood, vision, physical functioning and neuropsychological tests. The on-road test used in the study was a standard assessment procedure developed by the Driver Assessment Rehabilitation Service to determine fitness to drive. Of the 90 participants in the study, 68 passed the driving test, 8 passed but were recommended to have lessons and 14 failed the test. Driving test scores for the study were based on the number of errors committed in the driving tests, with weightings given according to the seriousness of the errors. In order to identify risk factors for inadequate driver self-regulation, comparisons were made between the functional tests most strongly related to driving performance and the functional tests most strongly related to self-regulation. It was concluded that self-regulation of driving behaviour is inadequate among older drivers with poor contrast sensitivity, poor speed of information processing and poor visuospatial ability.M.R.J. Baldock, J.L. Mathias, A.J. McLean and A. Bernd

Deriving the ultrastructure of α-crustacyanin using lower-resolution structural and biophysical methods

The structure of α-crustacyanin has been determined to 30 Å resolution using negative-stain electron microscopy (EM) single-particle averaging and modelling with the β-crustacyanin dimer from the crystal structure (Protein Data Bank code 1gka), guided by PISA protein subunit interface calculations for 1gka, and compared with the protein arrangements observed in the crystal lattice of 1gka. This α-crustacyanin EM model has been checked against SAXS experimental data, including comparison with rigid-body models calculated from the SAXS data, and finally with analytical ultracentrifugation measurements

Assessment of the response of pollinator abundance to environmental pressures using structured expert elicitation

Policy-makers often need to rely on experts with disparate fields of expertise when making policy choices in complex, multi-faceted, dynamic environments such as those dealing with ecosystem services. For policy-makers wishing to make evidence-based decisions which will best support pollinator abundance and pollination services, one of the problems faced is how to access the information and evidence they need, and how to combine it to formulate and evaluate candidate policies. This is even more complex when multiple factors provide influence in combination. The pressures affecting the survival and pollination capabilities of honey bees (Apis mellifera), wild bees, and other pollinators are well documented, but incomplete. In order to estimate the potential effectiveness of various candidate policy choices, there is an urgent need to quantify the effect of various combinations of factors on the pollination ecosystem service. Using high-quality experimental evidence is the most robust approach, but key aspects of the system may not be amenable to experimentation or may be prohibitive based on cost, time and effort. In such cases, it is possible to obtain the required evidence by using structured expert elicitation, a method for quantitatively characterizing the state of knowledge about an uncertain quantity. Here we report and discuss the outputs of the novel use of a structured expert elicitation, designed to quantify the probability of good pollinator abundance given a variety of weather, disease, and habitat scenarios

Measuring And Modelling The Water Balance Of Low Rainfall Cropping Systems

In low-rainfall cropping systems, understanding the water balance, and in particular the storage of soil water in the rooting zone for use by crops, is considered critical for devising risk management strategies for grain-based farming. Crop-soil modeling remains a cost-effective option for understanding the interactions between rainfall, soil, and crop growth, from which management options can be derived. The objective of this study was to assess the error in the prediction of soil water content at key decision points in the season against continuous, multi-layer soil water measurements made with frequency domain reflectometry (FDR) probes in long-term experiments in the Mallee region of South Australia and New South Wales. Field estimates of the crop lower limit or drained upper limit were found to be more reliable than laboratory- based estimates, despite the fact that plant-available water capacity (PAWC) did not substantially differ between the methods. Using the Agricultural Production Systems sIMulator (APSIM) to simulate plant-available water over three-year rotations, predicted soil water was within 7 mm (PAWC 64 to 99 mm) of the measured data across all sowing events and rotations. Simulated (n = 46) wheat grain production resulted in a root mean square error (RMSE) of 492 kg ha-1, which is only marginally smaller than that of other field studies that derived soil water limits with less detailed methods. This study shows that using field-derived data of soil water limits and soil-specific settings for parameterization of other properties that determine soil evaporation and water redistribution enables APSIM to be widely applied for managing climate risk in low-rainfall environments

Families, work and social care in Europe. A qualitative study of care arrangements in Finland, France, Italy, Portugal and the UK

The SOCCARE Project studied social care arrangements of European families in five different socio-economic and cultural environments that represent the variety of European welfare states (Finland, France, Italy, Portugal and the UK). It focused on four key family types that all are heavily affected by the ongoing demographic, socio-economic and structural changes within European societies: 1) lone parent families, 2) dual-career families, 3) immigrant families and, 4) “double front carer” families (that have young children and, at the same time, elderly family members in need of care).European Commission, 5th Framework Programm

Evolution-based screening enables genome-wide prioritization and discovery of DNA repair genes

DNA repair is critical for genome stability and is maintained through conserved pathways. Traditional genome-wide mammalian screens are both expensive and laborious. However, computational approaches circumvent these limitations and are a powerful tool to identify new DNA repair factors. By analyzing the evolutionary relationships between genes in the major DNA repair pathways, we uncovered functional relationships between individual genes and identified partners. Here we ranked 17,487 mammalian genes for coevolution with 6 distinct DNA repair pathways. Direct comparison to genetic screens for homologous recombination or Fanconi anemia factors indicates that our evolution-based screen is comparable, if not superior, to traditional screening approaches. Demonstrating the utility of our strategy, we identify a role for the DNA damage-induced apoptosis suppressor (DDIAS) gene in double-strand break repair based on its coevolution with homologous recombination. DDIAS knockdown results in DNA double-strand breaks, indicated by ATM kinase activation and 53BP1 foci induction. Additionally, DDIAS-depleted cells are deficient for homologous recombination. Our results reveal that evolutionary analysis is a powerful tool to uncover novel factors and functional relationships in DNA repair