Size-selective sampling of particulates using a physiologic sampling pump

Recent laboratory research indicates physiologic sampling of gas and vapor may provide more representative estimates of personal exposures than traditional methods. Modifications to the physiologic sampling pump (PSP) used in that research are described which extend its usefulness to size-selective sampling of particulates. PSPs used in previous research varied motor speed to keep sampling proportional to the subject's inhalation. This caused airflow and particle velocities through the collection device to continually change making those pumps unsuitable for sampling particulates. The modified implementation of the PSP pulls a constant airflow into and through a cyclone, then uses valves to either direct the airflow through, or divert the airflow around, the sampling filter. By using physiologic inputs to regulate the fraction of each second that air flows through the sampling filter, samples may be collected in proportion to inhalation rate. To evaluate the performance of a functional prototype 5 different sizes of monodisperse aerosols of ammonium fluorescein were generated by a vibrating orifice aerosol generator and introduced into a calm air chamber. To simulate different inhalation rates the valves of the PSP were energized using 9 different duty cycles. Efficiency curves are presented and compared to a standard respirable convention by bias mapping. The performance of the modified cyclone used in the PSP sampling head compared favorably with a commercially available cyclone of the same model, operating at a constant airflow (± 10% over almost all the size distributions of concern). The new method makes physiologic sampling of the respirable fraction of particulates feasible.     

Biomonitoring for exposure to multiple trace elements via analysis of urine from participants in the study of metals and assisted reproductive technologies (SMART)

Humans are exposed to concentrations of multiple trace elements through a variety of background sources; many are suspected reproductive toxicants. Prior to investigating associations between trace elements and human reproductive health, potential biomarkers of exposure should be characterized by sources of variability in the population at risk. Factors influencing elemental exposure should also be identified to ensure their consideration as potential confounding variables. The principal aim of this study is to characterize sources of variability for 19 trace elements measured in urine specimens collected from 55 women and 36 male partners completing a 1st cycle of in vitro fertilization (IVF). Urine specimens were analyzed using a biomonitoring method based on inductively coupled plasma-mass spectrometry (ICP-MS). Randomly selected urine specimens (～6%) were analyzed in duplicate, and these data were used to characterize sources of variability. Nine trace elements including As, Ba, Cd, Cs, Co, Cu, Mn, Mo, and Zn, were quantified in most specimens, indicating their utility in future epidemiologic studies of trace elements exposure and IVF outcomes. With few exceptions, normalizing urine using the traditional creatinine-correction procedure, or an alternative approach based on a linear regression model, increased residual variability only slightly. Sex and race appear to be important factors to consider in epidemiologic studies conducted in this population. Urine concentrations for most elements are similar to those reported in the 2005-2006 National Health and Nutrition Examination Survey (NHANES); however, differences in others may indicate regional trends or a unique exposure history for this infertile study population.     

Estimation of the contributions of long range transported aerosol in East Asia to carbonaceous aerosol and PM concentrations in Seoul, Korea using highly time resolved measurements: a PSCF model approach

The contributions of long range transported aerosol in East Asia to carbonaceous aerosol and particulate matter (PM) concentrations in Seoul, Korea were estimated with potential source contribution function (PSCF) calculations. Carbonaceous aerosol (organic carbon (OC) and elemental carbon (EC)), PM(2.5), and PM(10) concentrations were measured from April 2007 to March 2008 in Seoul, Korea. The PSCF and concentration weighted trajectory (CWT) receptor models were used to identify the spatial source distributions of OC, EC, PM(2.5), and coarse particles. Heavily industrialized areas in Northeast China such as Harbin and Changchun and East China including the Pearl River Delta region, the Yangtze River Delta region, and the Beijing-Tianjin region were identified as high OC, EC and PM(2.5) source areas. The conditional PSCF analysis was introduced so as to distinguish the influence of aerosol transported from heavily polluted source areas on a receptor site from that transported from relatively clean areas. The source contributions estimated using the conditional PSCF analysis account for not only the aerosol concentrations of long range transported aerosols but also the number of transport days effective on the measurement site. Based on the proposed algorithm, the condition of airmass pathways was classified into two types: one condition where airmass passed over the source region (PS) and another condition where airmass did not pass over the source region (NPS). For most of the seasons during the measurement period, 249.5-366.2% higher OC, EC, PM(2.5), and coarse particle concentrations were observed at the measurement site under PS conditions than under NPS conditions. Seasonal variations in the concentrations of OC, EC, PM(2.5), and coarse particles under PS, NPS, and background aerosol conditions were quantified. The contributions of long range transported aerosols on the OC, EC, PM(2.5), and coarse particle concentrations during several Asian dust events were also estimated. We also investigated the performance of the PSCF results obtained from combining highly time resolved measurement data and backward trajectory calculations via comparison with those from data in low resolutions. Reduced tailing effects and the larger coverage over the area of interest were observed in the PSCF results obtained from using the highly time resolved data and trajectories.     

Application of a battery of biomarkers in mussel digestive gland to assess long-term effects of the Prestige oil spill in Galicia and Bay of Biscay: tissue-level biomarkers and histopathology

In order to assess the biological effects of the Prestige oil spill (POS), mussels, Mytilus galloprovincialis, were collected in 22 localities along the North coast of the Iberian Peninsula over 3 years (April 2003-April 2006). Different tissue-level biomarkers including cell type composition (volume density of basophilic cells, Vv(BAS)) in digestive gland epithelium, structural changes of digestive alveoli (mean luminal radius to mean epithelial thickness, MLR/MET) and histopathological alterations (prevalence and intensity) of the digestive gland were analysed. Severe alterations in the general condition of the digestive gland tissue were observed all over the study area up to 2004-2005. High Vv(BAS) values were recorded mainly in Galicia but also to a lesser extent in the Bay of Biscay in 2003-2004. Atrophy of the digestive alveoli, measured in terms of MLR/MET, was detected all along the studied area up to 2006. Inflammatory responses cannot be related to pollution due to the POS: (a) prevalence and intensity of focal hemocytic infiltration were higher in the Bay of Biscay than in Galicia but they did not show a clear temporal trend; (b) high intensities of brown cell aggregates were only sporadically recorded; and (c) granulocytomas were more frequently recorded in the Bay of Biscay than in Galicia and especially in localities (i.e. Arrigunaga) subjected to chronic pollution. Likewise, Marteilia, trematodes, intracellular ciliates, unidentified eosinophilic bodies, R/CLO and Mytilicola did not follow any recognisable pattern that could be associated to the POS. In contrast, high Nematopsis intensities recorded in several localities in 2003 might suggest some response of local interest after the POS (i.e., in combination with particular factors/conditions). More data at a regional scale are needed before histopathology may provide a reliable ecosystem health assessment but the present results suggest that the approach is worthwhile. Overall, although Vv(BAS) returned to reference values by 2004-2005, MLR/MET values indicated that the mussel health condition was affected during the whole study period up to April 2006.     

Inhibitor resistance and in situ capability of nanoparticle based gene quantification

We have demonstrated the preliminary results of the in situ monitoring capability of an inhibitor resistant gene quantification assay using magnetic bead (MB) and quantum dot (QD) nanoparticles (hereafter "MB-QD assay") for the detection of E. coli O157:H7 in environmental samples. The selectivity of the MB-QD assay was demonstrated via the discrimination of the target bacteria in the presence of nonspecific microbial populations. The effect of temperature on the assay was examined to evaluate the necessity of elevated temperature incubation. The reagents (i.e., particle complex and particle-DNA conjugate) were also shown to have a stability of at least 10 days without refrigeration, therefore enabling prior preparation and the subsequent storage of these reagents. In addition, it was found that the MB-QD assay was resistant to the presence of naturally occurring inhibitors (i.e., humic acids, Ca(2+)) and residual reagents from DNA extraction (i.e., surfactant, ethanol). Overall the results indicated that the MB-QD assay is potentially suitable for further development as an in situ bacteria monitoring method for working with inhibitor laden samples without requiring additional purification steps and elevated temperature processes.     

Proactive socialization behavior in China: The mediating role of perceived insider status and the moderating role of supervisors' traditionality

This paper identified the dimensions of proactive socialization behavior among Chinese employees. We examined the mediating effects of perceived insider status on the relationships between proactive socialization behavior and socialization outcomes, and the moderating effect of supervisors' traditionality on the relationship between proactive socialization behavior and perceived insider status. Results from 280 newcomer–supervisor pairs supported the hypotheses that proactive socialization behavior was positively associated with task performance and social integration through perceived insider status. In addition, supervisors' traditionality significantly influenced the indirect relationships that proactive socialization behavior had with task performance and social integration via perceived insider status, such that the relationships became weaker as supervisors' traditionality increased. Copyright © 2013 John Wiley & Sons, Ltd.     

An evaluation approach using a HARA and FMEDA for the hardware SIL

Safety instrumented systems (SIS) are becoming increasingly complex, and form a growing proportion of programmable electronic parts. The IEC 61508 global standard was established to ensure the functional safety of SIS; however, it was expressed in highly macroscopic terms. The safety integrity level (SIL) is a criterion describing whether a component meets the safety requirements of a SIS. The safety requirements give a target SIL for the expected risks using hazard analysis and risk assessment (HARA). The SIL must correspond to the safety requirements. This study introduces an evaluation process for determining the hardware SIL through failure modes, effects, and diagnostic analysis (FMEDA). First, the components of the SIS subsystem are defined in terms of failure modes and effects, and then the failure rate and failure mechanism distribution are assigned to each component. The safety mode and detectability of each failure mode are determined for each component and, finally, the hardware SIL is evaluated. We perform a case study to evaluate the hardware SIL of the flame scanner system using HARA and FMEDA, where the safety requirement of the flame scanner was determined using the risk graph method. We verified that the hardware SIL of the flame scanner corresponded to the safety requirement.     

Flame acceleration in unconfined hydrogen/air deflagrations using infrared photography

Flame behavior and blast waves generated during unconfined hydrogen deflagrations were experimentally studied using infrared photography. Infrared photography enables expanding spherical flame behaviors to be measured and flame acceleration exponents to be evaluated. In the present experiments, hydrogen/air mixtures of various concentrations were filled in a plastic tent of thin vinyl sheet of 1 m³ and ignited by an electric spark. The onset of accelerative dynamics on the flame propagation was analyzed by the time histories of the flame radius and the stretched flame speed. The results demonstrated that the self-acceleration of the flame, which was caused by diffusional-thermal and hydrodynamic instabilities of the blast wave, was influenced by hydrogen deflagrations in unconfined areas. In particular, it was demonstrated that the overpressure rapidly increased with time. The burning velocity acceleration was greatly enhanced with spontaneous-turbulization.     

Flood Forecasting Using Neural Computing Techniques and Conceptual Class Segregation

Various neural networks models are developed and applied for flood forecasting at Sangye station (no. 1) of the Bocheong Stream catchment, which is one of the International Hydrological Program's representative catchments, Republic of Korea. The neural networks models (NNMs) are multilayer perceptron‐neural networks model (MLP‐NNM), generalized regression neural networks model (GRNNM), and Kohonen self‐organizing feature maps neural networks model (KSOFM‐NNM). Data used for model training and testing are divided into two groups: such as floods and typhoon events. Single conventional application and class segregation implementation are applied to evaluate the neural networks models. KSOFM‐NNM forecasts flood discharge more accurately than do MLP‐NNM and GRNNM for the testing data of Methods I and II for single conventional application and class segregation implementation. This study shows that class segregation can capture the dynamics of different physical processes and overcome the difficulties using single conventional application of neural networks models.     

Prenatal diagnosis of a familial complex chromosomal rearrangement involving chromosomes 5, 10, 16 and 18

We report one case of a familial complex chromosomal rearrangement (CCR) involving four different chromosomes 5, 10, 16 and 18. The CCR was detected prenatally at 20 weeks' gestation because of advanced maternal age and history of recurrent miscarriages. Cytogenetic analysis of cultured amniotic fluid cells with GTG banding showed a 46,XX,t(5;16;10;18)(q13;q22;q11.2;q21) karyotype. Parental cytogenetic study revealed that the mother has the same CCR. RBG banding, high-resolution banding and fluorescence in situ hybridization (FISH) were used to characterize further and confirm the conventional banding data. No physical abnormalities were shown in the targeted fetal ultrasonography examination. The parents decided to continue the pregnancy. The child is now 2 years old and has neither congenital anomalies nor evidence of delayed psychomotor development. The fetal targeted ultrasound and FISH analysis helped us reassure fetal status. Copyright © 2002 John Wiley & Sons, Ltd.