European aspects of standard setting in occupational hygiene and medicine

Occupational standards concerning the allowable concentrations of chemical compounds in the ambient air of workplaces have been established in several countries at national levels. With the integration of the European Union, a need exists for establishing harmonized Occupational Exposure Limits. For analytical developments, it is apparent that methods for speciation or fractionation of carcinogenic metal compounds will be of increasing practical importance for standard setting. Criteria of applicability under field conditions, cost-effectiveness, and robustness are practical driving forces for new developments. When the European Union issued a list of 62 chemical substances with Occupational Exposure Limits in 2000, 25 substances received a 'skin' notation. The latter indicates that toxicologically significant amounts may be taken up via the skin. Similar notations exist on national levels. For such substances, monitoring concentrations in ambient air will not be sufficient; biological monitoring strategies will gain further importance in the medical surveillance of workers who are exposed to such compounds. Proceedings in establishing legal frameworks for a biological monitoring of chemical exposures within Europe are paralleled by scientific advances in this field. A new aspect is the possibility of a differential adduct monitoring, using blood proteins of different half-life or lifespan. This technique allows differentiation between long-term mean exposure to reactive chemicals and short-term episodes, for example, by accidental overexposure. For further analytical developments, the following issues have been addressed as being particularly important: New dose monitoring strategies, sensitive and reliable methods for detection of DNA adducts, cytogenetic parameters in biological monitoring, methods to monitor exposure to sensitizing chemicals, and parameters for individual susceptibilities to chemical toxicants.

The use of prescribed drugs for common chronic conditions in South Africa in 1998

Purpose To determine the prescribed drug-utilisation pattern for six common chronic conditions in adult South Africans in a cross-sectional survey. Methods 13 826 randomly selected participants, 15 years and older, were surveyed by trained fieldworkers at their homes in 1998. Questionnaires included socio-demographic, chronic-disease and drug-use data. The prescribed drugs were recorded from participants' medication containers. The Anatomical Therapeutic Classification (ATC) code of the drugs for tuberculosis (TB), diabetes, hypertension, hyperlipidaemia, other atherosclerosis-related conditions, such as heart conditions or cerebrovascular accidents (CVA), and asthma or chronic obstructive pulmonary disease (COPD), was recorded. The use of logistic regression analyses identified the determinants of those patients who used prescription medication for these six conditions. Results 18.4% of the women and 12.5% of the men used drugs for the six chronic conditions. Men used drugs most frequently for hypertension (50.9%) and asthma or chronic bronchitis (24.3%), while in women it was for hypertension (59.9%) and diabetes (17.5%). The logistic regression analyses showed that women, wealthier and older people, and those with medical insurance used these chronic-disease drugs more frequently compared to men, younger or poor people, or those without medical insurance. The African population group used these drugs less frequently than any other ethnic group. The inappropriate use of methyldopa was found for 14.8% of all antihypertensive drugs, while very few people used aspirin. Conclusions The methodology of this study provides a means of ascertaining the chronic-disease drug-utilisation pattern in national health surveys. The pattern described, suggests an inequitable use of chronic-disease drugs and inadequate use of some effective drugs to control the burden of chronic diseases in South Africa. Copyright © 2004 John Wiley & Sons, Ltd.

Marginal costs of hospital-acquired conditions : information for priority-setting for patient safety programmes and research

Objective: To estimate the relative inpatient costs of hospital-acquired conditions. Methods: Patient level costs were estimated using computerized costing systems that log individual utilization of inpatient services and apply sophisticated cost estimates from the hospital's general ledger. Occurrence of hospital-acquired conditions was identified using an Australian ‘condition-onset' flag for diagnoses not present on admission. These were grouped to yield a comprehensive set of 144 categories of hospital-acquired conditions to summarize data coded with ICD-10. Standard linear regression techniques were used to identify the independent contribution of hospital-acquired conditions to costs, taking into account the case-mix of a sample of acute inpatients (n = 1,699,997) treated in Australian public hospitals in Victoria (2005/06) and Queensland (2006/07). Results: The most costly types of complications were post-procedure endocrine/metabolic disorders, adding AU$21,827 to the cost of an episode, followed by MRSA (AU$19,881) and enterocolitis due to Clostridium difficile (AU$19,743). Aggregate costs to the system, however, were highest for septicaemia (AU$41.4 million), complications of cardiac and vascular implants other than septicaemia (AU$28.7 million), acute lower respiratory infections, including influenza and pneumonia (AU$27.8 million) and UTI (AU$24.7 million). Hospital-acquired complications are estimated to add 17.3% to treatment costs in this sample. Conclusions: Patient safety efforts frequently focus on dramatic but rare complications with very serious patient harm. Previous studies of the costs of adverse events have provided information on ‘indicators’ of safety problems rather than the full range of hospital-acquired conditions. Adding a cost dimension to priority-setting could result in changes to the focus of patient safety programmes and research. Financial information should be combined with information on patient outcomes to allow for cost-utility evaluation of future interventions.

Behaviour of LSF floor systems with improved joist sections under fire conditions

Fire safety design of buildings is essential to safeguard lives and minimize the loss of damage to properties. Light-weight cold-formed steel channel sections along with fire resistive plasterboards are used to construct light gauge steel frame floor systems to provide the required fire resistance rating. However, simply adding more plasterboard layers is not an efficient method to increase FRR. Hence this research focuses on using joists with improved joist section profiles such as hollow flange sections to increase the structural capacity of floor systems under fire conditions and thus their FRR. In this research, the structural and thermal behaviour of LSF floor systems made of LiteSteel Beams with different plasterboard and insulation configurations was investigated using four full scale tests under standard fires. Based on the ultimate failure load of the floor joist at ambient temperature, transient state fire tests were conducted for different Load Ratios. These fire tests showed that the new LSF floor system has improved the FRR well above that of those made of lipped channel sections. The joist failure was predominantly due to local buckling of LSB compression flanges near mid-span with severe yielding of tension flanges. Fire tests have provided valuable structural and thermal performance data of tested floor systems that included time-temperature profiles, and failure times and temperatures. Average failure temperatures of LSB joists and reduced yield strengths were used to predict their ultimate moment capacities, which were compared with corresponding test capacities. This allowed an assessment in relation to the accuracy of current design rules for steel joists at elevated temperatures. This paper presents the details of full scale fire tests of LSF floor systems made of LSB joists with different plasterboard and insulation configurations and their results along with some important findings.

Shear tests of hollow flange channel beams with real support conditions

This paper presents the details of experimental studies on the effect of real support conditions on the shear strength of hollow flange channel beams, known as LiteSteel beams (LSB). The LSB has a unique shape of a channel beam with two rectangular hollow flanges, made using a unique manufacturing process. In many applications in the building industry LSBs are used with only one web side plate (WSP) at their supports. The WSPs are also often not full height plates. Past research studies showed that these real support connections did not provide the required simply supported conditions. Many studies have been carried out to evaluate the behaviour and design of LSBs with simply supported conditions subject to pure bending and predominant shear actions. To date, however, no investigation has been conducted into the effect of real support conditions on the shear strength of LSBs. Hence a detailed experimental study based on 25 shear tests was undertaken to investigate the shear behaviour and strength of LSBs with real support conditions. Simply supported test specimens of LSBs with aspect ratios of 1.0 and 1.5 were loaded at mid-span until failure. It was found that the effect of using one WSP on the shear behaviour of LSB is significant and there is about 25% shear capacity reduction due to the lateral movement of the bottom flange at the supports. Shear capacity of LSB was also found to decrease when full height WSPs were not used. Suitably improved support connections were developed to improve the shear capacity of LSBs based on test results. Details of the recommended support connections and shear capacity results are given in this paper.

Experimental study of cold-formed steel floors made of hollow flange channel section joists under fire conditions

Fire safety plays a vital role in building design because appropriate level of fire safety is important to safeguard lives and property. Cold-formed steel channel sections along with fire-resistive plasterboards are used to construct light-gauge steel frame (LSF) floor systems to provide adequate fire resistance ratings (FRR). It is common practice to use lipped channel sections (LCS) as joists in LSF floor systems, and past research has only considered such systems. This research focuses on adopting improved joist sections such as hollow flange channel (HFC) sections to improve the structural performance and FRR of cold-formed LSF floor systems under standard fire conditions. The structural and thermal performances of LSF floor systems made of a welded HFC, LiteSteel Beams (LSB), with different plasterboard and insulation configurations, were investigated using four full-scale fire tests under standard fires. These fire tests showed that the new LSF floor system with LSB joists improved the FRR in comparison to that of conventional LCS joists. Fire tests have provided valuable structural and thermal performance data of tested floor systems that included time-temperature profiles and failure times, temperatures, and modes. This paper presents the details of the fire tests conducted in this study and their results along with some important findings.

The treatment of recurrent abdominal pain in children : a controlled comparison of cognitive-behavioral family intervention and standard pediatric care

This study describes the results of a controlled clinical trial involving 44 7- to 14-year-old children with recurrent abdominal pain who were randomly allocated to either cognitive-behavioral family intervention (CBFI) or standard pediatric care (SPC). Both treatment conditions resulted in significant improvements on measures of pain intensity and pain behavior. However, the children receiving CBFI had a higher rate of complete elimination of pain, lower levels of relapse at 6- and 12-month follow-up, and lower levels of interference with their activities as a result of pain and parents reported a higher level of satisfaction with the treatment than children receiving SPC. After controlling for pretreatment levels of pain, children's active self-coping and mothers' caregiving strategies were significant independent predictors of pain behavior at posttreatment.

Measuring free ellagic acid: influence of extraction conditions on recovery by studying solubility and UV-Visible spectra

Recent investigations into plant tissues have indicated that the free form of the natural polyphenolic antioxidant, ellagic acid (EA), is much more plentiful than first envisaged; consequently a re-assessment of solvent systems for the extraction of this water-insoluble form is needed. As EA solubility and its UV-Vis spectrum, commonly used for detection and quantification, are both governed by pH, an understanding of this dependence is vital if accurate EA measurements are to be achieved. After evaluating the pH effects on the solubility and UV-Vis spectra of commercial EA, an extraction protocol was devised that promoted similar pH conditions for both standard solutions and plant tissue extracts. The extraction so devised followed by HPLC with photodiode-array detection (DAD) provided a simple, sensitive and validated methodology that determined free EA in a variety of plant extracts. The use of 100 % methanol or a triethanolamine-based mixture as the standard dissolving solvents were the best choices, while these higher pH-generating solvents were more efficient in extracting EA from the plants tested with the final choice allied to the plants’ natural acidity. Two of the native Australian plants anise myrtle (Syzygium anisatum) and Kakadu plum (Terminalia ferdinandiana) exhibited high concentrations of free EA. Furthermore, the dual approach to measuring EA UV-Vis spectra made possible an assessment of the effect of acidified eluent on EA spectra when the DAD was employed.

Anomalous triple gauge boson couplings in e(-)e(+) -> gamma gamma for noncommutative standard model

We investigate e(+)e(-) -> gamma gamma process within the Seiberg-Witten expanded noncommutative standard model (NCSM) scenario in the presence of anomalous triple gauge boson couplings. This study is done with and without initial beam polarization and we restrict ourselves to leading order effects of noncommutativity i.e. O(Theta). The noncommutative (NC) corrections are sensitive to the electric component ((Theta) over bar (E)) of NC parameter. We include the effects of Earth's rotation in our analysis. This study is done by investigating the effects of noncommutativity on different time averaged cross section observables. We have also defined forward backward asymmetries which will be exclusively sensitive to anomalous couplings. We have looked into the sensitivity of these couplings at future experiments at the International Linear Collider (ILC). This analysis is done under realistic ILC conditions with the center of mass energy (cm.) root s = 800 GeV and integrated luminosity L = 500 fb(-1). The scale of noncommutativity is assumed to be Lambda = 1 TeV. The limits on anomalous couplings of the order 10(-1) from forward backward asymmetries while much stringent limits of the order 10(-2) from total cross section are obtained if no signal beyond SM is seen. (C) 2012 Elsevier B.V. All rights reserved.

Soft-spring wall based non-periodic boundary conditions for non-equilibrium molecular dynamics of dense fluids

Non-equilibrium molecular dynamics (MD) simulations require imposition of non-periodic boundary conditions (NPBCs) that seamlessly account for the effect of the truncated bulk region on the simulated MD region. Standard implementation of specular boundary conditions in such simulations results in spurious density and force fluctuations near the domain boundary and is therefore inappropriate for coupled atomistic-continuum calculations. In this work, we present a novel NPBC model that relies on boundary atoms attached to a simple cubic lattice with soft springs to account for interactions from particles which would have been present in an untruncated full domain treatment. We show that the proposed model suppresses the unphysical fluctuations in the density to less than 1% of the mean while simultaneously eliminating spurious oscillations in both mean and boundary forces. The model allows for an effective coupling of atomistic and continuum solvers as demonstrated through multiscale simulation of boundary driven singular flow in a cavity. The geometric flexibility of the model enables straightforward extension to nonplanar complex domains without any adverse effects on dynamic properties such as the diffusion coefficient. (c) 2015 AIP Publishing LLC.

Prediction of Land Surface Temperature under Cloudy Conditions using Microwave Remote Sensing and ANN

Land surface temperature (LST) is an important variable in climate, hydrologic, ecological, biophysical and biochemical studies (Mildrexler et al., 2011). The most effective way to obtain LST measurements is through satellites. Presently, LST from moderate resolution imaging spectroradiometer (MODIS) sensor is applied in various fields due to its high spatial and temporal availability over the globe, but quite difficult to provide observations in cloudy conditions. This study evolves of prediction of LST under clear and cloudy conditions using microwave vegetation indices (MVIs), elevation, latitude, longitude and Julian day as inputs employing an artificial neural network (ANN) model. MVIs can be obtained even under cloudy condition, since microwave radiation has an ability to penetrate through clouds. In this study LST and MVIs data of the year 2010 for the Cauvery basin on a daily basis were obtained from MODIS and advanced microwave scanning radiometer (AMSR-E) sensors of aqua satellite respectively. Separate ANN models were trained and tested for the grid cells for which both LST and MVI were available. The performance of the models was evaluated based on standard evaluation measures. The best performing model was used to predict LST where MVIs were available. Results revealed that predictions of LST using ANN are in good agreement with the observed values. The ANN approach presented in this study promises to be useful for predicting LST using satellite observations even in cloudy conditions. (C) 2015 The Authors. Published by Elsevier B.V.

Invisible decays of the heavier Higgs boson in the minimal supersymmetric standard model

We consider the possibility that the heavier CP-even Higgs boson (H-0) in the minimal supersymmetric standard model (MSSM) decays invisibly into neutralinos in the light of the recent discovery of the 126 GeV resonance at the CERN Large Hadron Collider (LHC). For this purpose we consider the minimal supersymmetric standard model with universal, nonuniversal and arbitrary boundary conditions on the supersymmetry breaking gaugino mass parameters at the grand unified scale. Typically, scenarios with universal and nonuniversal gaugino masses do not allow invisible decays of the lightest Higgs boson (h(0)), which is identified with the 126 GeV resonance, into the lightest neutralinos in the MSSM. With arbitrary gaugino masses at the grand unified scale, such an invisible decay is possible. The second lightest Higgs boson can decay into various invisible final states for a considerable region of the MSSM parameter space with arbitrary gaugino masses as well as with the gaugino masses restricted by universal and nonuniversal boundary conditions at the grand unified scale. The possibility of the second lightest Higgs boson of the MSSM decaying into invisible channels is more likely for arbitrary gaugino masses at the grand unified scale. The heavier Higgs boson decay into lighter particles leads to the intriguing possibility that the entire Higgs boson spectrum of the MSSM may be visible at the LHC even if it decays invisibly, during the searches for an extended Higgs boson sector at the LHC. In such a scenario the nonobservation of the extended Higgs sector of the MSSM may carefully be used to rule out regions of the MSSM parameter space at the LHC.

Experimentally Determined Flame Properties near Flammability Limits Under Gravity and Microgravity Conditions

Flammability limits for flames propagating in a rich propane/air mixture under gravity conditions appeared to be 6.3% C3H8 for downward propagation and 9.2% C3H8 for upward propagation. Different limits might be explained by the action of preferential diffusion of the deficient reactant (Le < 1) on the limit flames, which are in different states of instability. In one of the previous studies, the flammability limits under microgtravity conditions were found to be between the upward and downward limits obtained in a standard flammability tube under normal gravity conditions. It was found in those experiments that there are two limits under microgravity conditions: one indicated by visible flame propagation and another indicated by an increase of pressure without observed flame propagation. These limits were found to be far behind the limit for downward-propagating flame at 1 g (6.3% C3H8) and close to the limit for upward-propagating flame at 1 g (9.2% C3H8). It was decided in the present work to apply a special schlieren system and instant temperature measuring system for drop tower experiments to observe combustion development during propagation of the flame front. A small cubic closed vessel (inner side, 9 cm 9 cm 9 cm) with schlieren quality glass windows were used to study limit flames under gravity and microgravity conditions. Flame development in rich limit mixtures, not visible in previous experiments under microgravity conditions for strait photography, was identified with the use of the schlieren method and instant temperature measuring system. It was found in experiments in a small vessel that there is practically no difference in flammability limits under gravity and microgravity conditions. In this paper, the mechanism of flame propagation under these different conditions is systematically studied and compared and limit burning velocity is estimated.

Density-potential mapping in the standard and quantum electrodynamical time-dependent density functional theory

131 p.

Effect of analytical conditions in wavelength dispersive electron microprobe analysis on the measurement of strontium-to-calcium (Sr/Ca) ratios in otoliths of anadromous salmonids

The use of strontium-to-calcium (Sr/Ca) ratios in otoliths is becoming a standard method to describe life history type and the chronology of migrations between freshwater and seawater habitats in teleosts (e.g. Kalish, 1990; Radtke et al., 1990; Secor, 1992; Rieman et al., 1994; Radtke, 1995; Limburg, 1995; Tzeng et al. 1997; Volk et al., 2000; Zimmerman, 2000; Zimmerman and Reeves, 2000, 2002). This method provides critical information concerning the relationship and ecology of species exhibiting phenotypic variation in migratory behavior (Kalish, 1990; Secor, 1999). Methods and procedures, however, vary among laboratories because a standard method or protocol for measurement of Sr in otoliths does not exist. In this note, we examine the variations in analytical conditions in an effort to increase precision of Sr/Ca measurements. From these findings we argue that precision can be maximized with higher beam current (although there is specimen damage) than previously recommended by Gunn et al. (1992).