634 research outputs found

    Baseline environmental radon survey at Lake Way, Western Australia, September 1979.

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    A survey of radon and radon daughters in the air has been made at and within a few kilometres of the possible uranium mine near Millbillillie at the northern edge of Lake Way, Western Australia. The data have been correlated with meteorological measurements taken concurrently with the radon survey. In addition radon emanation rates and radon levels in water have been measured at a broad range of sites to define more closely the magnitude and extent of radon in the environment

    Meteorological and radiation measurements at Nabarlek, Northern Territory, June to July 1979.

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    A meteorological and radiation measurement program was conducted near the then developing uranium mine at Nabarlek in the Northern Territory. The two-filter tube radiation measuring technique was checked and compared with the continuous radon monitor and instant working level meter techniques. In general the Nabarlek meteorology was characterised by weak stable layers and good ventilation conditions with winds rarely less than 1ms -1. A comparison of wind measurements made near the open pit with those taken some 800 m away gave evidence of horizontal changes in the wind field over the site. Strong daytime winds gusting higher than 10 ms -1 caused a visible suspension of dust from the site. Dust deposition samples indicated that thorium-230 in air on site was a factor of twelve below the maximum permissible concentration for employees in Australia but uranium was lower by several orders of magnitude. The concentrations of radioactivity in the aquatic food pathway external radiation levels and radon daughter concentrations from deposited dust were likewise at least two orders of magnitude below the maximum concentrations permissible in Australia

    Cost of managing an episode of relapse in multiple sclerosis in the United States

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    BACKGROUND: The purpose of this study was to determine the direct medical US cost of managing multiple sclerosis relapses. METHODS: Direct data analysis and cost modeling were employed to derive typical resource use profiles and costs in 2002 US dollars, from the perspective of a third-party payer responsible for comprehensive health-care. The location and scope of health care services provided over a 90-day period were used to define three levels of relapse management. Hospitalization and resulting subsequent care was defined as high intensity management. A medium level of intervention was defined as either use of the emergency room, an observational unit, or administration of acute treatments, such as intravenous methylprednisolone in an outpatient or home setting. The lowest intensity of care comprised physician office visits and symptom-related medications. Data were obtained from many sources including all payer inpatient, ambulatory and emergency room databases from several states, fee schedules, government reports, and literature. All charges were adjusted using cost-to-charge ratios. RESULTS: Average cost per person for high management level was 12,870,basedonanalysisof4,634hospitalcases(meanage48years,7312,870, based on analysis of 4,634 hospital cases (mean age 48 years, 73% female). Hospital care comprised 71% of that cost. At discharge, 36% required inpatient sub-acute care, rehabilitation or home care. The typical cost per moderate episode was 1,847 and mild episode $243. CONCLUSIONS: Management strategies leading to a reduction in the frequency and severity of a relapse, less reliance on inpatient care, or increased access to steroid infusions in the home, would have a substantial impact on the economic consequences of managing relapses

    Effect of restricting silage feeding prepartum on time of calving, dystocia and stillbirth in Holstein-Friesian cows

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    A study was carried out to investigate the effect of restricting silage feeding on time of calving and calving performance in Holstein-Friesian cows. In the treatment group (n = 1,248 cows, 12 herds) silage feeding commenced in the evening (17:00 to 20:00 h), after a period of restricted access (2 to 10 h) while in the control group ad-libitum access to silage was provided over the 24 h period (n = 1,193 cows, 12 herds). Daytime and nighttime calvings were defined as calvings occurring between the hours of 06:30 and 00:29 and between 00:30 and 06:29, respectively. Restricting access to silage resulted in less calvings at night compared to cows with ad-libitum access to silage (18 vs 22%, P < 0.05). Cows with restricted access to silage had a higher percentage of difficult calvings (11 vs 7%, P < 0.001) and stillbirths (7 vs 5%, P < 0.05) compared to cows in the control group. The percentage of calvings at night was lower (13%) when access to silage was restricted for 10 h compared to 2, 4 or 6 h (22, 18, 25%, respectively) (P < 0.001). Calf sire breed, calf gender or cow parity did not influence time of calving. In conclusion, offering silage to pregnant Holstein-Friesian cows in the evening, after a period of restricted access, reduced the incidence of nighttime calvings, but increased the incidence of dystocia and stillbirth

    "They all work...when you stick to them" : a qualitative investigation of dieting, weight loss, and physical exercise, in obese individuals

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    BackgroundTo explore the extent to which people living with obesity have attempted to lose weight, their attitudes towards dieting, physical exercise and weight loss solutions, why their weight loss attempts have failed, and their opinions about what would be most beneficial to them in their struggle with their weight.MethodQualitative study, using open-ended interviews, of 76 people living with obesity in Victoria, Australia in 2006/7. Individuals with a BMI of 30 or over were recruited using articles in local newspapers, convenience sampling, and at a later stage purposive sampling techniques to diversify the sample. Data analysis was conducted by hand using a constant, comparative method to develop and test analytical categories. Data were interpreted both within team meetings and through providing research participants the chance to comment on the study findings.ResultsWhilst participants repeatedly turned to commercial diets in their weight loss attempts, few had used, or were motivated to participate in physical activity. Friends or family members had introduced most individuals to weight loss techniques. Those who took part in interventions with members of their social network were more likely to report feeling accepted and supported. Participants blamed themselves for being unable to maintain their weight loss or \u27stick\u27 to diets. Whilst diets did not result in sustained weight loss, two thirds of participants felt that dieting was an effective way to lose weight.ConclusionIndividuals with obesity receive numerous instructions about what to do to address their weight, but very few are given appropriate long term guidance or support with which to follow through those instructions. Understanding the positive role of social networks may be particularly important in engaging individuals in physical activity. Public health approaches to obesity must engage and consult with those currently living with obesity, if patterns of social change are to occur

    Mortality after discharge from long-term psychiatric care in Scotland, 1977 – 94: a retrospective cohort study

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    BACKGROUND: Recent United Kingdom strategies focus on preventable suicide deaths in former psychiatric in-patients, but natural causes of death, accidents and homicide may also be important. This study was intended to find the relative importance of natural and unnatural causes of death in people discharged from long-term psychiatric care in Scotland in 1977 –1994. METHODS: People discharged alive from psychiatric hospitals in Scotland in 1977 – 94 after a stay of one year or longer were identified using routine hospital records. Computer record linkage was used to link hospital discharges to subsequent death records. Mortality was described using a person-years analysis, and compared to the general population rates. RESULTS: 6,776 people were discharged in the time period. 1,994 people (29%) died by the end of follow-up, 732 more deaths than expected. Deaths from suicide, homicide, accident and undetermined cause were increased, but accounted for only 197 of the excess deaths. Deaths from respiratory disease were four times higher than expected, and deaths from other causes, including cardiovascular disease, were also elevated. CONCLUSION: Suicide is an important cause of preventable mortality, but natural causes account for more excess deaths. Prevention activities should not focus only on unnatural causes of death

    Testing foundations of quantum mechanics with photons

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    The foundational ideas of quantum mechanics continue to give rise to counterintuitive theories and physical effects that are in conflict with a classical description of Nature. Experiments with light at the single photon level have historically been at the forefront of tests of fundamental quantum theory and new developments in photonics engineering continue to enable new experiments. Here we review recent photonic experiments to test two foundational themes in quantum mechanics: wave-particle duality, central to recent complementarity and delayed-choice experiments; and Bell nonlocality where recent theoretical and technological advances have allowed all controversial loopholes to be separately addressed in different photonics experiments.Comment: 10 pages, 5 figures, published as a Nature Physics Insight review articl

    The Morphology and Intrinsic Excitability of Developing Mouse Retinal Ganglion Cells

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    The retinal ganglion cells (RGCs) have diverse morphology and physiology. Although some studies show that correlations between morphological properties and physiological properties exist in cat RGCs, these properties are much less distinct and their correlations are unknown in mouse RGCs. In this study, using three-dimensional digital neuron reconstruction, we systematically analyzed twelve morphological parameters of mouse RGCs as they developed in the first four postnatal weeks. The development of these parameters fell into three different patterns and suggested that contact from bipolar cells and eye opening might play important roles in RGC morphological development. Although there has been a general impression that the morphological parameters are not independent, such as RGCs with larger dendritic fields usually have longer but sparser dendrites, there was not systematic study and statistical analysis proving it. We used Pearson's correlation coefficients to determine the relationship among these morphological parameters and demonstrated that many morphological parameters showed high statistical correlation. In the same cells we also measured seven physiological parameters using whole-cell patch-clamp recording, focusing on intrinsic excitability. We previously reported the increase in intrinsic excitability in mouse RGCs during early postnatal development. Here we showed that strong correlations also existed among many physiological parameters that measure the intrinsic excitability. However, Pearson's correlation coefficient revealed very limited correlation across morphological and physiological parameters. In addition, principle component analysis failed to separate RGCs into clusters using combined morphological and physiological parameters. Therefore, despite strong correlations within the morphological parameters and within the physiological parameters, postnatal mouse RGCs had only limited correlation between morphology and physiology. This may be due to developmental immaturity, or to selection of parameters

    The time course of subsequent hospitalizations and associated costs in survivors of an ischemic stroke in Canada

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    BACKGROUND: Documentation of the hospitalizations rates following a stroke provides the inputs required for planning health services and to evaluate the economic efficiency of any new therapies. METHODS: Hospitalization rates by cause were examined using administrative data on 18,695 patients diagnosed with ischemic stroke (first or subsequent, excluding transient ischemic attack) in Saskatchewan, Canada between 1990 and 1995. Medical history was available retrospectively to January 1980 and follow-up was complete to March 2000. Analyses evaluated the rate and timing of all-cause and cardiovascular hospitalizations within discrete periods in the five years following the index stroke. Cardiovascular hospitalizations included patients with a primary diagnosis of ischemic stroke, transient ischemic attack, myocardial infarction, stable or unstable angina, heart failure or peripheral arterial disease. RESULTS: One-third (36%) of patients were identified by a hospitalized stroke. Mean age was 70.5 years, 48.0% were male, half had a history of stroke or a transient ischemic attack at the time of their index stroke. Three-quarters of the patients (72.7%) were hospitalized at least once during a mean follow-up of 4.6 years, accruing CAD $24 million in the first year alone. Of all hospitalizations, 20.4% were related to cardiovascular disease and 1.6% to bleeds. In the month following index stroke, 12.5% were admitted, an average of 1.04 times per patient hospitalized. Strokes accounted for 33% of all hospitalizations in the first month. The rate diminished steadily throughout the year and stabilized in the second year when approximately one-third of patients required hospitalization, at a rate of about one hospitalization for every two patient-years. Mean lengths of stay ranged from nine days to nearly 40 days. Close-fitting Weibull functions allow highly specific probability estimates. Other cardiovascular risk factors significantly increased hospitalization rates. CONCLUSION: After stroke, there are frequent hospitalizations accounting for substantial additional costs. Though these rates drop after one year, they remain high over time. The number of other cardiovascular causes of hospitalization confirms that stroke is a manifestation of disseminated atherothrombotic disease

    Gene expression in cardiac tissues from infants with idiopathic conotruncal defects

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    <p>Abstract</p> <p>Background</p> <p>Tetralogy of Fallot (TOF) is the most commonly observed conotruncal congenital heart defect. Treatment of these patients has evolved dramatically in the last few decades, yet a genetic explanation is lacking for the failure of cardiac development for the majority of children with TOF. Our goal was to perform genome wide analyses and characterize expression patterns in cardiovascular tissue (right ventricle, pulmonary valve and pulmonary artery) obtained at the time of reconstructive surgery from 19 children with tetralogy of Fallot.</p> <p>Methods</p> <p>We employed genome wide gene expression microarrays to characterize cardiovascular tissue (right ventricle, pulmonary valve and pulmonary artery) obtained at the time of reconstructive surgery from 19 children with TOF (16 idiopathic and three with 22q11.2 deletions) and compared gene expression patterns to normally developing subjects.</p> <p>Results</p> <p>We detected a signal from approximately 26,000 probes reflecting expression from about half of all genes, ranging from 35% to 49% of array probes in the three tissues. More than 1,000 genes had a 2-fold change in expression in the right ventricle (RV) of children with TOF as compared to the RV from matched control infants. Most of these genes were involved in compensatory functions (e.g., hypertrophy, cardiac fibrosis and cardiac dilation). However, two canonical pathways involved in spatial and temporal cell differentiation (WNT, <it>p </it>= 0.017 and Notch, <it>p </it>= 0.003) appeared to be generally suppressed.</p> <p>Conclusions</p> <p>The suppression of developmental networks may represent a remnant of a broad malfunction of regulatory pathways leading to inaccurate boundary formation and improper structural development in the embryonic heart. We suggest that small tissue specific genomic and/or epigenetic fluctuations could be cumulative, leading to regulatory network disruption and failure of proper cardiac development.</p
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