Decomposing the change in labour force indicators over time

In this paper we study changes in the size and the composition of the labour force in five OECD countries from 1983 through 2000. We apply a recent decomposition method to quantify the components of the change over time in the crude labour force rate and the mean age of the labour force. Our results show that the change in the crude labour force rate was dominated by the change in age-specific labour force participation rates. For the mean age of the labour force we find that for males the change in the age composition of the population predominately explains the overall change while the results for females are less clear-cut

Butyltin compounds in a sediment core from the old Tilbury basin, London, UK

Sections from a sediment core taken from the River Thames were analysed for butyltin species using gas chromatography with species-specific isotope dilution mass spectrometry. Results demonstrated that in most samples tributyltin concentrations of 20–60 ng/g accounted for <10% of the total butyltin species present, which is in agreement with data from other sediment samples which were historically contaminated with tributyltin. Vertical distribution of the organotin residues with depth throughout the core, with data on organochlorine compounds and heavy metals allowed for the construction of a consistent hypothesis on historical deposition of contaminated sediments. From this it was possible to infer that the concentrations of tributyltin in sediments deposited during the early 1960s were in the order of 400–600 lg/g by using degradation rate constants derived by other workers. Such values fall well within the range quoted for harbour sediments in the literature

To grow or to fluctuate: Optimal paths to demographic equilibria

The principal goal of this paper is to establish a firm fundament of population policy. It is shown how intertemporal optimisation theory can be used to fulfill this important task. In particular, this will be illustrated by calculating the optimal trade-off between the further growth (or shrinking) of a population and the fluctuations of its age-structure generated by the decline (or the increase) of the fertility. While the system dynamics of the age-structured optimal control model considered in this paper is described by the McKendrick-von Foerster partial differential equation, its objective functional is given by the discounted stream of the adaptation costs of the net reproduction rate (NRR) and the aforementioned trade-off. For the sake of obtaining analytic results the model is reduced to concentrated vitality rates. Its essential results for growing and declining populations are that under-/over shooting of the NRR is optimal for a short time horizon, whereas a fluctuating NRR takes over if the time horizon is extended. Numerical simulations for a stylized population structure show how the change in the NRR carries over to the total population and age-groups along time

Fertility decline and age-structure in China and India

China and India, two Asian countries that experienced a rapid decline in fertility since the middle of the twentieth century, are the focus of this paper. Although there is no doubt that lower fertility levels have many positive effects on the economy, development and sustainability, little is known about the optimal transition from high to medium or even low levels of fertility. Firstly, implementing policies that have the potential to reduce fertility is costly. Secondly, additional costs arise from adapting the infrastructure to a population that fluctuates quickly not only in terms of size but also with respect to the age structure. We apply an intertemporal optimisation model that takes the costs and benefits of fertility decline into account. The optimal time path depends on the cost structure, the planning horizon and the initial conditions. In the case of a long planning horizon and high initial fertility, it may even be optimal to reduce fertility temporarily below replacement level in order to slow down population growth at an early stage. A key finding of our formal investigation is that, under the same plausible parameter settings, the optimal paths for China and India differ substantially. Moreover, our analysis shows that India, where the fertility decline emerged as a consequence of societal and economic developments, followed a path closer to the optimal fertility transition than China, where the fertility decline was state-imposed. The mathematical approach deployed for this analysis provides insights into the optimal long-term development of fertility and allows for policy conclusions to be drawn for other countries that are still in the fertility transition process

A novel and practical screening tool for the detection of silent myocardial infarction in patients with type 2 diabetes

Silent myocardial infarction (MI) is a prevalent finding in patients with type 2 diabetes and is associated with significant mortality and morbidity. Late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR) is the most validated technique for detection of silent MI but is time consuming, costly and requires administration of intravenous contrast. We therefore planned to develop a simple and low cost population screening tool to identify those at highest risk of silent MI validated against the CMR reference standard.100 asymptomatic patients with type 2 diabetes underwent electrocardiogram (ECG), echocardiography, biomarker assessment and CMR at 3.0T including assessment of left ventricular ejection fraction and LGE. Global longitudinal strain (GLS) from 2 and 4 chamber cines was measured using feature tracking.17/100 patients with no history of cardiovascular disease had silent MI defined by LGE in an infarct pattern on CMR. Only 4 silent MI patients had Q waves on ECG. Patients with silent MI were older (65 vs 60, p=0.05), had lower E/A ratio (0.75 vs 0.89, p=0.004), lower GLS (-15.2% vs -17.7%, p=0.004) and higher NT-proBNP (106ng/L vs 52ng/L, p=0.003). A combined risk score derived from these 4 factors had an area under the receiver operating characteristic (ROC) curve of 0.823 (0.734-0.892), P<0.0001. A score of ?3/5 had 82% sensitivity and 72% specificity for silent MI.Using measures that can be derived in an outpatient clinic setting, we have developed a novel screening tool for the detection of silent MI in type 2 diabetes. The screening tool had significantly superior diagnostic accuracy than current ECG criteria for the detection of silent MI in asymptomatic patients

The patient's perspective of placebo use in daily practice: a qualitative study

QUESTIONS UNDER STUDY: The use of placebo outside of randomised controlled trials raises ethical and legal issues. So far, patients' perspectives have been considered only in quantitative studies. These studies did not distinguish between pure placebos (no pharmacological effect) and impure placebos (pharmacological ingredient, but no disease-specific effect). The aim of our study was to explore patients' conceptualisation, experiences and attitudes regarding the use of placebos in daily clinical practice. METHODS: Qualitative study with a convenience sample of 12 patients and semistructured interviews. The interviews were digitally recorded; full transcripts were obtained. The information was analysed in accordance with the qualitative content analysis method. RESULTS: The definition of placebo given by the participants mostly matched the common understanding of a pure placebo. Most participants supposed that placebos were mainly effective in diseases in which psychological influences play an important role. Furthermore, most participants believed that placebos themselves mainly worked via psychological effects. The acceptance of a hypothetical earlier use of a placebo depended on the success of the therapy. CONCLUSION: Patients were not aware of the differences between pure and impure placebos. Even regarding pure placebos, patients were more open than many physicians would expect. Trust between the patient and the general practitioner is an important element of the acceptance of a placebo. Appropriate communication could further increase the acceptance. Further research is needed to adapt the information given to the patient about possible placebo therapy

Toxic metal enrichment and boating intensity: sediment records of antifoulant copper in shallow lakes of eastern England

Tributyltin (TBT), an aqueous biocide derived from antifouling paint pollution, is known to have impacted coastal marine ecosystems, and has been reported in the sediment of the Norfolk and Suffolk Broads, a network of rivers and shallow lakes in eastern England. In the marine environment, the 1987 TBT ban has resulted in expanded use of alternative biocides, raising the question of whether these products too have impacted the Broads ecosystem and freshwaters in general. Here we examine the lake sediment record in the Norfolk and Suffolk Broads for contamination by copper (Cu) (as an active biocide agent) and zinc (Zn) (as a component of booster biocides), to assess their occurrence and potential for causing environmental harm in freshwater ecosystems. We find that, after the introduction of leisure boating, there is a statistically significant difference in Cu enrichment between heavily and lightly boated sites, while no such difference exists prior to this time. At the heavily boated sites the onset of Cu enrichment coincides with a period of rapid increase in leisure boating. Such enrichment is maintained to the present day, with some evidence of continued increase. We conclude that Cu-based antifouling has measurably contaminated lakes exposed to boating, at concentrations high enough to cause ecological harm. Similar findings can be expected at other boated freshwater ecosystems elsewhere in the world

The read-across hypothesis and environmental risk assessment of pharmaceuticals

This article is made available through the Brunel Open Access Publishing Fund. Copyright © 2013 American Chemical Society.Pharmaceuticals in the environment have received increased attention over the past decade, as they are ubiquitous in rivers and waterways. Concentrations are in sub-ng to low μg/L, well below acute toxic levels, but there are uncertainties regarding the effects of chronic exposures and there is a need to prioritise which pharmaceuticals may be of concern. The read-across hypothesis stipulates that a drug will have an effect in non-target organisms only if the molecular targets such as receptors and enzymes have been conserved, resulting in a (specific) pharmacological effect only if plasma concentrations are similar to human therapeutic concentrations. If this holds true for different classes of pharmaceuticals, it should be possible to predict the potential environmental impact from information obtained during the drug development process. This paper critically reviews the evidence for read-across, and finds that few studies include plasma concentrations and mode of action based effects. Thus, despite a large number of apparently relevant papers and a general acceptance of the hypothesis, there is an absence of documented evidence. There is a need for large-scale studies to generate robust data for testing the read-across hypothesis and developing predictive models, the only feasible approach to protecting the environment.BBSRC Industrial Partnership Award BB/ I00646X/1 and BBSRC Industrial CASE Partnership Studentship BB/I53257X/1 with AstraZeneca Safety Health and Environment Research Programme

The Liquid Argon Jet Trigger of the H1 Experiment at HERA

We report on a novel trigger for the liquid argon calorimeter which was installed in the H1 Experiment at HERA.This trigger, called the “Jet Trigger”, was running at level 1 and implemented a real-time cluster algorithm. Within only 800 ns, the Jet Trigger algorithm found local energy maxima in the calorimeter, summed their immediate neighbors, sorted the resulting jets by energy, and applied topological conditions for the final level 1 trigger decision. The Jet Trigger was in operation from the year 2006 until the end of the HERA running in the summer of 2007. With the Jet Trigger it was possible to substantially reduce the thresholds for triggering on electronsand jets, giving access to a largely extended phase space for physical observables which could not have been reached in H1 before. The concepts of the Jet Trigger may be an interesting upgrade option for the LHC experiments

Factors affecting variability in the urinary biomarker 1,6-hexamethylene diamine in workers exposed to 1,6-hexamethylene diisocyanate

Although urinary 1,6-hexamethylene diamine (HDA) is a useful biomarker of exposure to 1,6-hexamethylene diisocyanate (HDI), a large degree of unexplained intra- and inter-individual variability exists between estimated HDI exposure and urine HDA levels. We investigated the effect of individual and workplace factors on urine HDA levels using quantitative dermal and inhalation exposure data derived from a survey of automotive spray painters exposed to HDI. Painters' dermal and breathing-zone HDI-exposures were monitored over an entire workday for up to three separate workdays, spaced approximately one month apart. One urine sample was collected before the start of work with HDI-containing paints, and multiple samples were collected throughout the workday. Using mixed effects multiple linear regression modeling, coverall use resulted in significantly lower HDA levels (p = 0.12), and weekday contributed to significant variability in HDA levels (p = 0.056). We also investigated differences in urine HDA levels stratified by dichotomous and classification covariates using analysis of variance. Use of coveralls (p = 0.05), respirator type worn (p = 0.06), smoker status (p = 0.12), paint-booth type (p = 0.02), and more than one painter at the shop (p = 0.10) were all found to significantly affect urine HDA levels adjusted for creatinine concentration. Coverall use remained significant (p = 0.10), even after adjusting for respirator type. These results indicate that the variation in urine HDA level is mainly due to workplace factors and that appropriate dermal and inhalation protection is required to prevent HDI exposure