Evaluation of a gamma monitor for survey of waste for shallow land burial

During an 8-month evaluation of the Gamma Waste Monitor, 54 reactor-area scrap casks and 8 shipments from the separations areas containing fission product activities were measured. It was concluded that a more accurate and detailed record of radionuclide burials can be obtained by using this monitor than by present methods of estimation. The monitor will significantly improve records and will provide a more reliable data base for evaluating long-term effects on the environment. Although the monitor can directly detect only gamma-emitting radionuclides, a method is proposed in this report for estimating the total radionuclide distribution by association with radionuclides that are detected. The monitor cannot assay transuranic waste and tritium. In many cases where the radionuclide emits two gamma rays of different energy, corrections for attenuation at other photon energies can be empirically derived from the spectrum. Complete details are included in the Appendix for operating the facility. Experimental data gathered during the evaluation period are contained in the body of this report

Regional Variation in the Incidence of End-Stage Renal Disease in Indigenous Australians

Objective: To evaluate regional variation in the incidence of end-stage renal disease (ESRD) in Indigenous Australians, and to examine the proximity to ESRD treatment facilities of Indigenous patients. Design: Secondary data review, with collection of primary data regarding patients' place of residence before beginning ESRD treatment. Participants: Indigenous ESRD patients who commenced treatment in Australia during 1993-1998. Methods: We obtained data from the Australian and New Zealand Dialysis and Transplant Registry regarding 719 Indigenous patients who started ESRD treatment between 1 January 1993 and 31 December 1998. We obtained primary data from the treating renal units to determine the place of residence before beginning renal replacement therapy. We calculated the average annual incidence of ESRD for each of the 36 Aboriginal and Torres Strait Islander Commission regions using population estimates based on the 1996 Census, and calculated standardised incidence ratios with 95% confidence intervals for each region. We compared the number of cases with the treatment facilities available in each region. Main outcome measure: Regional standardised ESRD incidence for Indigenous Australians referenced to the total resident population of Australia. Results: Standardised ESRD incidence among Indigenous Australians is highest in remote regions, where it is up to 30 times the national incidence for all Australians. In urban regions the standardised incidence is much lower, but remains significantly higher than the national incidence. Forty-eight per cent of Indigenous ESRD patients come from regions without dialysis or transplant facilities and 16.3% from regions with only satellite dialysis facilities. Conclusions: There is marked regional variation in the incidence of ESRD among Indigenous Australians. Because of the location of treatment centres, there is inequitable access to ESRD treatment services for a significant proportion of Indigenous patients

Investigating the Role of Current Strength in tDCS Modulation of Working Memory Performance in Healthy Controls

Transcranial direct current stimulation (tDCS) is a brain stimulation technique that has the potential to improve working memory (WM) deficits in many clinical disorders. The aim of this study was to investigate the role of current strength on the ability of anodal tDCS to improve WM, and secondly to investigate the time course of effects. Twelve healthy participants underwent three stimulation sessions consisting of 20 min of either 1 mA anodal tDCS, 2 mA anodal tDCS, or sham tDCS to the left dorsolateral prefrontal cortex (DLPFC) localized via F3, all whilst completing a WM task. Intra-stimulation and post-stimulation WM performances were measured using the n-back and Sternberg tasks respectively. Results revealed no significant improvements in participants’ accuracy, but a significant interaction was found with respect to current strength and time for accurate reaction time. The finding provides partial support for the hypothesis, in that it appears current strength may affect aspects of WM performance. However, more research is needed, and a higher difficulty level of WM tasks is one of the suggestions discussed for future research

Strain Hardening of Polymer Glasses: Entanglements, Energetics, and Plasticity

Simulations are used to examine the microscopic origins of strain hardening in polymer glasses. While stress-strain curves for a wide range of temperature can be fit to the functional form predicted by entropic network models, many other results are fundamentally inconsistent with the physical picture underlying these models. Stresses are too large to be entropic and have the wrong trend with temperature. The most dramatic hardening at large strains reflects increases in energy as chains are pulled taut between entanglements rather than a change in entropy. A weak entropic stress is only observed in shape recovery of deformed samples when heated above the glass transition. While short chains do not form an entangled network, they exhibit partial shape recovery, orientation, and strain hardening. Stresses for all chain lengths collapse when plotted against a microscopic measure of chain stretching rather than the macroscopic stretch. The thermal contribution to the stress is directly proportional to the rate of plasticity as measured by breaking and reforming of interchain bonds. These observations suggest that the correct microscopic theory of strain hardening should be based on glassy state physics rather than rubber elasticity.Comment: 15 pages, 12 figures: significant revision

Use of the Global Alliance for Musculoskeletal Health survey module for estimating the population prevalence of musculoskeletal pain: Findings from the Solomon Islands

Background: Musculoskeletal (MSK) conditions are common and the biggest global cause of physical disability. The objective of the current study was to estimate the population prevalence of MSK-related pain using a standardized global MSK survey module for the first time. Methods: A MSK survey module was constructed by the Global Alliance for Musculoskeletal Health Surveillance Taskforce and the Global Burden of Disease MSK Expert Group. The MSK module was included in the 2015 Solomon Islands Demographic and Health Survey. The sampling design was a two-stage stratified, nationally representative sample of households. Results: A total of 9214 participants aged 15-49 years were included in the analysis. The age-standardized four-week prevalence of activity-limiting low back pain, neck pain, and hip and/or knee pain was 16.8, 8.9, and 10.8%, respectively. Prevalence tended to increase with age, and be higher in those with lower levels of education. Conclusions: Prevalence of activity-limited pain was high in all measured MSK sites. This indicates an important public health issue for the Solomon Islands that needs to be addressed. Efforts should be underpinned by integration with strategies for other non-communicable diseases, aging, disability, and rehabilitation, and with other sectors such as social services, education, industry, and agriculture. Primary prevention strategies and strategies aimed at self-management are likely to have the greatest and most cost-effective impact

Tensile Fracture of Welded Polymer Interfaces: Miscibility, Entanglements and Crazing

Large-scale molecular simulations are performed to investigate tensile failure of polymer interfaces as a function of welding time $t$. Changes in the tensile stress, mode of failure and interfacial fracture energy $G_I$ are correlated to changes in the interfacial entanglements as determined from Primitive Path Analysis. Bulk polymers fail through craze formation, followed by craze breakdown through chain scission. At small $t$ welded interfaces are not strong enough to support craze formation and fail at small strains through chain pullout at the interface. Once chains have formed an average of about one entanglement across the interface, a stable craze is formed throughout the sample. The failure stress of the craze rises with welding time and the mode of craze breakdown changes from chain pullout to chain scission as the interface approaches bulk strength. The interfacial fracture energy $G_I$ is calculated by coupling the simulation results to a continuum fracture mechanics model. As in experiment, $G_I$ increases as $t^{1/2}$ before saturating at the average bulk fracture energy $G_b$. As in previous simulations of shear strength, saturation coincides with the recovery of the bulk entanglement density. Before saturation, $G_I$ is proportional to the areal density of interfacial entanglements. Immiscibiltiy limits interdiffusion and thus suppresses entanglements at the interface. Even small degrees of immisciblity reduce interfacial entanglements enough that failure occurs by chain pullout and $G_I \ll G_b$

Renal biopsy findings among Indigenous Australians: a nationwide review

Australia's Indigenous people have high rates of chronic kidney disease and kidney failure. To define renal disease among these people, we reviewed 643 renal biopsies on Indigenous people across Australia, and compared them with 249 biopsies of non-Indigenous patients. The intent was to reach a consensus on pathological findings and terminology, quantify glomerular size, and establish and compare regional biopsy profiles. The relative population-adjusted biopsy frequencies were 16.9, 6.6, and 1, respectively, for Aboriginal people living remotely/very remotely, for Torres Strait Islander people, and for non-remote-living Aboriginal people. Indigenous people more often had heavy proteinuria and renal failure at biopsy. No single condition defined the Indigenous biopsies and, where biopsy rates were high, all common conditions were in absolute excess. Indigenous people were more often diabetic than non-Indigenous people, but diabetic changes were still present in fewer than half their biopsies. Their biopsies also had higher rates of segmental sclerosis, post-infectious glomerulonephritis, and mixed morphologies. Among the great excess of biopsies in remote/very remote Aborigines, females predominated, with younger age at biopsy and larger mean glomerular volumes. Glomerulomegaly characterized biopsies with mesangiopathic changes only, with IgA deposition, or with diabetic change, and with focal segmental glomerulosclerosis (FSGS). This review reveals great variations in biopsy rates and findings among Indigenous Australians, and findings refute the prevailing dogma that most indigenous renal disease is due to diabetes. Glomerulomegaly in remote/very remote Aboriginal people is probably due to nephron deficiency, in part related to low birth weight, and probably contributes to the increased susceptibility to kidney disease and the predisposition to FSGS

Effect of Intraplant Insect Movement on Economic Thresholds

A simulation model was constructed to examine the effects of intraplant spatial dynamics of the lepidopteran pest complex of cabbage on direct damage to the marketable parts of the plant. Diurnal fluctuations in microclimate for different parts of the crop canopy were simulated with sine functions. Larval development rates for each species were simulated with logistic functions of temperature, the development process with time-varying distributed delays, and feeding rates with exponential functions of temperature and larval age. Larval transition probabilities within the crop canopy were modeled with either constants or definite integrals of the Beta probability density function, the shape parameters of which were modeled as functions of temperature. The model provided a good fit to data on changes in intraplant distribution of these larvae and intraplant distribution of feeding damage. Evaluation of model predictions suggests that a threshold population density used for management decisions should not be static, but should be a complex function of species, larval age distribution, and forecast temperatures. A model like the one presented here could serve as that complex functio

Development of Single-station Early Warning Lightning Alarm System

Lightning is one of the spectacular natural phenomena which happen on the earth. More than 2000 people are killed worldwide by lightning each year. The lightning monitoring system is important as the early warning alarm system. In this paper,lightning warning alarm system which can monitor and observe the lightning activity has been discussed. The system able to trigger the warning alarm whenever a lightning strikes at a particular area in 10 km radius from UMP Pekan, Pahang, Malaysia. The LabVIEW software was used as a data logger to measure, analyze and calculate the lightning distance. The accuracy of the system has been compared and validated by the Pekan Lightning Detection System (PLDS)

A comparison of statistical hadronization models

We investigate the sensitivity of fits of hadron spectra produced in heavy ion collisions to the choice of statistical hadronization model. We start by giving an overview of statistical model ambiguities, and what they tell us about freeze-out dynamics. We then use Montecarlo generated data to determine sensitivity to model choice. We fit the statistical hadronization models under consideration to RHIC data, and find that a comparison $\chi^2$ fits can shed light on some presently contentious questions.Comment: Proceedings for SQM2003 [7th Int. Conf. on Strangeness in Quark Matter (Atlantic Beach, NC, USA, Mar 12-17, 2003)], to be published in Journal of Physics G (Typos corrected, reference added