The effect of submersion in water and breathing modality (assisted breathing and apnea) on different stages of the information processing chain

Limited research has explored the impact of working underwater on the cognitive functioning of divers and even less has focused on the effect of breathing modality (assisted breathing and apnea) underwater. Research on the effect of submersion in water and apnea on cognitive performance is also very limited. As a result, the purpose of this study was to determine the effect of submersion in water and breathing modality on different stages of the information processing chain. This was achieved by testing participants in a laboratory setting under three conditions; on land, underwater with assisted breathing and underwater in apnea. Five different tests were used to determine which aspects of cognitive functioning were impaired in which condition. The recognition task result in the assisted breathing condition was significantly faster (p=0.04) but less accurate (p=0.01) than on land. The memory task was significantly (p=0.042) worse in terms of speed in the apnea condition compared to land, however accuracy was not affected. Performance in the visual detection task was impacted on in both underwater conditions compared to land with speed and accuracy being significantly worse (p<0.01) in the underwater conditions. These results indicate that simple tasks, (reaction time and tracking task) are not affected by condition whereas more complex tasks are. For tasks where an effect was found for only one condition, the effect was attributed to a specific aspect of that condition; either the breath hold or assisted breathing component of the condition. For tasks that were found to be affected in both underwater conditions, the effect was attributed to the actual submersion in water. The effect of the different conditions and the nature of the task they impact on should be considered for underwater work places as the general equipment used may impact on the quality of observations that are made

Quantile regression for mixed models with an application to examine blood pressure trends in China

Cardiometabolic diseases have substantially increased in China in the past 20 years and blood pressure is a primary modifiable risk factor. Using data from the China Health and Nutrition Survey, we examine blood pressure trends in China from 1991 to 2009, with a concentration on age cohorts and urbanicity. Very large values of blood pressure are of interest, so we model the conditional quantile functions of systolic and diastolic blood pressure. This allows the covariate effects in the middle of the distribution to vary from those in the upper tail, the focal point of our analysis. We join the distributions of systolic and diastolic blood pressure using a copula, which permits the relationships between the covariates and the two responses to share information and enables probabilistic statements about systolic and diastolic blood pressure jointly. Our copula maintains the marginal distributions of the group quantile effects while accounting for within-subject dependence, enabling inference at the population and subject levels. Our population-level regression effects change across quantile level, year and blood pressure type, providing a rich environment for inference. To our knowledge, this is the first quantile function model to explicitly model within-subject autocorrelation and is the first quantile function approach that simultaneously models multivariate conditional response. We find that the association between high blood pressure and living in an urban area has evolved from positive to negative, with the strongest changes occurring in the upper tail. The increase in urbanization over the last twenty years coupled with the transition from the positive association between urbanization and blood pressure in earlier years to a more uniform association with urbanization suggests increasing blood pressure over time throughout China, even in less urbanized areas. Our methods are available in the R package BSquare.Comment: Published at http://dx.doi.org/10.1214/15-AOAS841 in the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

The investigation into the optimisation of cross laminated timber panels for use in the Australia building industry

[Abstract]: This research paper will investigate the viability of using Low/Utility grade timber to construct timber beams, plate members and solid wall structures via a Cross-lamination process known as CLT. More specifically it will aim to uncover an optimum set to material specifications and dimensions for an engineered panel design. Due the many faults and defects in the utility grade timber it is often left to be used in wood chipping and wooden pallet manufacture, still this leaves a significant amount of product in storage, costing Hyne money. As well as producing a new structurally competitive product for Hyne Timber Australia, developing a method to structurally stabilise utility grade timber will drastically reduce wastage in the wood industry as well as provide an alternative to conventional brick and mortar building. The modelling procedure will be undertaken in the finite element modelling software package Strand 7. These models are built upon the current known data for the mechanical properties of Slash Pine. Utilising the known modulus of elasticity and the orientation of grain direction, a finite analysis can be performed, calculating stress and moment distributions and deflections under applied loading. The data gathered from these models will then be used to draw comparisons from standard slab performance tests and the expected usage of CLT panels to help assess with further research whether the development of CLT panels from timber of sub-par quality is viable

A randomized prospective long-term (\u3e 1 year) clinical trial comparing the efficacy and safety of radiofrequency ablation to 980nm laser ablation of the great saphenous vein

Purpose To compare the short- and long-term (\u3e1 year) efficacy and safety of radiofrequency ablation (ClosureFAST™) versus endovenous laser ablation (980 nm diode laser) for the treatment of superficial venous insufficiency of the great saphenous vein. Materials and methods Two hundred patients with superficial venous insufficiency of the great saphenous vein were randomized to receive either radiofrequency ablation or endovenous laser ablation (and simultaneous adjunctive therapies for surface varicosities when appropriate). Post-treatment sonographic and clinical assessment was conducted at one week, six weeks, and six months for closure, complications, and patient satisfaction. Clinical assessment of each patient was conducted at one year and then at yearly intervals for patient satisfaction. Results Post-procedure pain (p \u3c 0.0001) and objective post-procedure bruising (p = 0.0114) were significantly lower in the radiofrequency ablation group. Improvements in venous clinical severity score were noted through six months in both groups (endovenous laser ablation 6.6 to 1; radiofrequency ablation 6.2 to 1) with no significant difference in venous clinical severity score (p = 0.4066) or measured adverse effects; 89 endovenous laser ablation and 87 radiofrequency patients were interviewed at least 12 months out with a mean long-term follow-up of 44 and 42 months (p = 0.1096), respectively. There were four treatment failures in each group, and every case was correctable with further treatment. Overall, there were no significant differences with regard to patient satisfaction between radiofrequency ablation and endovenous laser ablation (p = 0.3009). There were no cases of deep venous thrombosis in either group at any time during this study. Conclusions Radiofrequency ablation and endovenous laser ablation are highly effective and safe from both anatomic and clinical standpoints over a multi-year period and neither modality achieved superiority over the other