Accounting for Unobservable Exposure Time Bias Wh...

Data.gov (United States)

U.S. Department of Health & Human Services — Accounting for Unobservable Exposure Time Bias When Using Medicare Prescription Drug Data Unobservable exposure time is common among Medicare Part D beneficiaries,...

Time-activity relationships to VOC personal exposure factors

Science.gov (United States)

Edwards, Rufus D.; Schweizer, Christian; Llacqua, Vito; Lai, Hak Kan; Jantunen, Matti; Bayer-Oglesby, Lucy; Künzli, Nino

Social and demographic factors have been found to play a significant role in differences between time-activity patterns of population subgroups. Since time-activity patterns largely influence personal exposure to compounds as individuals move across microenvironments, exposure subgroups within the population may be defined by factors that influence daily activity patterns. Socio-demographic and environmental factors that define time-activity subgroups also define quantifiable differences in VOC personal exposures to different sources and individual compounds in the Expolis study. Significant differences in exposures to traffic-related compounds ethylbenzene, m- and p-xylene and o-xylene were observed in relation to gender, number of children and living alone. Categorization of exposures further indicated time exposed to traffic at work and time in a car as important determinants. Increased exposures to decane, nonane and undecane were observed for males, housewives and self-employed. Categorization of exposures indicated exposure subgroups related to workshop use and living downtown. Higher exposures to 3-carene and α-pinene commonly found in household cleaning products and fragrances were associated with more children, while exposures to traffic compounds ethylbenzene, m- and p-xylene and o-xylene were reduced with more children. Considerable unexplained variation remained in categorization of exposures associated with home product use and fragrances, due to individual behavior and product choice. More targeted data collection methods in VOC exposure studies for these sources should be used. Living alone was associated with decreased exposures to 2-methyl-1-propanol and 1-butanol, and traffic-related compounds. Identification of these subgroups may help to reduce the large amount of unexplained variation in VOC exposure studies. Further they may help in assessing impacts of urban planning that result in changes in behavior of individuals, resulting in shifts in

Influence of exposure time on toxicity-An overview.

Science.gov (United States)

Connell, Des W; Yu, Qiming J; Verma, Vibha

2016-04-29

Data on toxicity of chemicals is usually reported as the LD50, or LC50, with the exposure time from experimental testing in the laboratory reported. But the exposure time is not considered to be a quantifiable variable which can be used to evaluate its importance in expressed toxicity, often described in general terms such as acute, chronic and so on. For the last hundred years Habers Rule has been successfully used to extrapolate from reported exposure times to other exposure times which may be needed for setting standards, health risk assessments and other applications. But it has limitations particularly in environmental applications where exposure levels are low and exposure times are relatively long. The Reduced Life Expectancy (RLE) model overcomes these problems and can be utilised under all exposure conditions. It can be expressed as ln(LT50)=-a (LC50)(ν)+b where the constants ν, a and b can be evaluated by fitting the model to experimental data on the LC50, and corresponding LT50, together with the Normal Life Expectancy (NLE) of the organism being considered as a data point when the LC50 is zero. The constant, ν, at a value of unity gives a linear relationship and where νmodel for fish, invertebrates and mammals involving 115 data sets and with a wide range of organic and inorganic toxicants the RLE model gave correlation coefficients of >0.8 with 107 sets of data. The RLE model can be used to extrapolate from a limited data set on exposure times and corresponding LT50 values to any exposure time and corresponding LT50 value. The discrepancy between Haber's Rule and RLE model increases as the exposure time increases. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

The Napoleon Complex: When Shorter Men Take More.

Science.gov (United States)

Knapen, Jill E P; Blaker, Nancy M; Van Vugt, Mark

2018-05-01

Inspired by an evolutionary psychological perspective on the Napoleon complex, we hypothesized that shorter males are more likely to show indirect aggression in resource competitions with taller males. Three studies provide support for our interpretation of the Napoleon complex. Our pilot study shows that men (but not women) keep more resources for themselves when they feel small. When paired with a taller male opponent (Study 1), shorter men keep more resources to themselves in a game in which they have all the power (dictator game) versus a game in which the opponent also has some power (ultimatum game). Furthermore, shorter men are not more likely to show direct, physical aggression toward a taller opponent (Study 2). As predicted by the Napoleon complex, we conclude that (relatively) shorter men show greater behavioral flexibility in securing resources when presented with cues that they are physically less competitive. Theoretical and practical implications are discussed.

Differential gene expression profiling of mouse skin after sulfur mustard exposure: Extended time response and inhibitor effect

International Nuclear Information System (INIS)

Gerecke, Donald R.; Chen Minjun; Isukapalli, Sastry S.; Gordon, Marion K.; Chang, Y.-C.; Tong Weida; Androulakis, Ioannis P.; Georgopoulos, Panos G.

2009-01-01

Sulfur mustard (HD, SM), is a chemical warfare agent that within hours causes extensive blistering at the dermal-epidermal junction of skin. To better understand the progression of SM-induced blistering, gene expression profiling for mouse skin was performed after a single high dose of SM exposure. Punch biopsies of mouse ears were collected at both early and late time periods following SM exposure (previous studies only considered early time periods). The biopsies were examined for pathological disturbances and the samples further assayed for gene expression profiling using the Affymetrix microarray analysis system. Principal component analysis and hierarchical cluster analysis of the differently expressed genes, performed with ArrayTrack showed clear separation of the various groups. Pathway analysis employing the KEGG library and Ingenuity Pathway Analysis (IPA) indicated that cytokine-cytokine receptor interaction, cell adhesion molecules (CAMs), and hematopoietic cell lineage are common pathways affected at different time points. Gene ontology analysis identified the most significantly altered biological processes as the immune response, inflammatory response, and chemotaxis; these findings are consistent with other reported results for shorter time periods. Selected genes were chosen for RT-PCR verification and showed correlations in the general trends for the microarrays. Interleukin 1 beta was checked for biological analysis to confirm the presence of protein correlated to the corresponding microarray data. The impact of a matrix metalloproteinase inhibitor, MMP-2/MMP-9 inhibitor I, against SM exposure was assessed. These results can help in understanding the molecular mechanism of SM-induced blistering, as well as to test the efficacy of different inhibitors

Effects of shorter versus longer storage time of transfused red blood cells in adult ICU patients

DEFF Research Database (Denmark)

Rygård, Sofie L; Jonsson, Andreas B; Madsen, Martin B

2018-01-01

on the effects of shorter versus longer storage time of transfused RBCs on outcomes in ICU patients. METHODS: We conducted a systematic review with meta-analyses and trial sequential analyses (TSA) of randomised clinical trials including adult ICU patients transfused with fresher versus older or standard issue...... blood. RESULTS: We included seven trials with a total of 18,283 randomised ICU patients; two trials of 7504 patients were judged to have low risk of bias. We observed no effects of fresher versus older blood on death (relative risk 1.04, 95% confidence interval (CI) 0.97-1.11; 7349 patients; TSA......-adjusted CI 0.93-1.15), adverse events (1.26, 0.76-2.09; 7332 patients; TSA-adjusted CI 0.16-9.87) or post-transfusion infections (1.07, 0.96-1.20; 7332 patients; TSA-adjusted CI 0.90-1.27). The results were unchanged by including trials with high risk of bias. TSA confirmed the results and the required...

Pollen exposure and hospitalization due to asthma exacerbations: daily time series in a European city

Science.gov (United States)

Osborne, Nicholas J.; Alcock, Ian; Wheeler, Benedict W.; Hajat, Shakoor; Sarran, Christophe; Clewlow, Yolanda; McInnes, Rachel N.; Hemming, Deborah; White, Mathew; Vardoulakis, Sotiris; Fleming, Lora E.

2017-10-01

Exposure to pollen can contribute to increased hospital admissions for asthma exacerbation. This study applied an ecological time series analysis to examine associations between atmospheric concentrations of different pollen types and the risk of hospitalization for asthma in London from 2005 to 2011. The analysis examined short-term associations between daily pollen counts and hospital admissions in the presence of seasonal and long-term patterns, and allowed for time lags between exposure and admission. Models were adjusted for temperature, precipitation, humidity, day of week, and air pollutants. Analyses revealed an association between daily counts (continuous) of grass pollen and adult hospital admissions for asthma in London, with a 4-5-day lag. When grass pollen concentrations were categorized into Met Office pollen `alert' levels, `very high' days (vs. `low') were associated with increased admissions 2-5 days later, peaking at an incidence rate ratio of 1.46 (95%, CI 1.20-1.78) at 3 days. Increased admissions were also associated with `high' versus `low' pollen days at a 3-day lag. Results from tree pollen models were inconclusive and likely to have been affected by the shorter pollen seasons and consequent limited number of observation days with higher tree pollen concentrations. Future reductions in asthma hospitalizations may be achieved by better understanding of environmental risks, informing improved alert systems and supporting patients to take preventive measures.

Effects of long-time elevated temperature exposures on hot-isostatically-pressed power-metallurgy Udimet 700 alloys with reduced cobalt contents

Science.gov (United States)

Hart, F. H.

1984-01-01

Because almost the entire U.S. consumption of cobalt depends on imports, this metal has been designated "strategic'. The role and effectiveness of cobalt is being evaluated in commercial nickel-base superalloys. Udiment 700 type alloys in which the cobalt content was reduced from the normal 17% down to 12.7%, 8.5%, 4.3%, and 0% were prepared by standard powder metallurgy techniques and hot isostatically pressed into billets. Mechanical testing and microstructural investigations were performed. The mechanical properties of alloys with reduced cobalt contents which were heat-treated identically were equal or better than those of the standard alloy, except that creep rates tended to increase as cobalt was reduced. The effects of long time exposures at 760 C on mechanical properties and at 760 C and 845 C on microstructures were determined. Decreased tensile properties and shorter rupture lives with increased creep rates were observed in alloy modifications. The exposures caused gamma prime particle coarsening and formation of sigma phase in the alloys with higher cobalt contents. Exposure at 845 C also reduced the amount of MC carbides.

36 CFR 223.81 - Shorter advertising periods in emergencies.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Shorter advertising periods... OF AGRICULTURE SALE AND DISPOSAL OF NATIONAL FOREST SYSTEM TIMBER Timber Sale Contracts Advertisement and Bids § 223.81 Shorter advertising periods in emergencies. In emergency situations where prompt...

Mediation analysis with time varying exposures and mediators.

Science.gov (United States)

VanderWeele, Tyler J; Tchetgen Tchetgen, Eric J

2017-06-01

In this paper we consider causal mediation analysis when exposures and mediators vary over time. We give non-parametric identification results, discuss parametric implementation, and also provide a weighting approach to direct and indirect effects based on combining the results of two marginal structural models. We also discuss how our results give rise to a causal interpretation of the effect estimates produced from longitudinal structural equation models. When there are time-varying confounders affected by prior exposure and mediator, natural direct and indirect effects are not identified. However, we define a randomized interventional analogue of natural direct and indirect effects that are identified in this setting. The formula that identifies these effects we refer to as the "mediational g-formula." When there is no mediation, the mediational g-formula reduces to Robins' regular g-formula for longitudinal data. When there are no time-varying confounders affected by prior exposure and mediator values, then the mediational g-formula reduces to a longitudinal version of Pearl's mediation formula. However, the mediational g-formula itself can accommodate both mediation and time-varying confounders and constitutes a general approach to mediation analysis with time-varying exposures and mediators.

Do shorter wavelengths improve contrast in optical mammography?

International Nuclear Information System (INIS)

Taroni, P; Pifferi, A; Torricelli, A; Spinelli, L; Danesini, G M; Cubeddu, R

2004-01-01

The detection of tumours with time-resolved transmittance imaging relies essentially on blood absorption. Previous theoretical and phantom studies have shown that both contrast and spatial resolution of optical images are affected by the optical properties of the background medium, and high absorption and scattering are generally beneficial. Based on these observations, wavelengths shorter than presently used (680-780 nm) could be profitable for optical mammography. A study was thus performed analysing time-resolved transmittance images at 637, 656, 683 and 785 nm obtained from 26 patients bearing 16 tumours and 15 cysts. The optical contrast proved to increase upon decreasing wavelengths for the detection of cancers in late-gated intensity images, with higher gain in contrast for lesions of smaller size (<1.5 cm diameter). For cysts either a progressive increase or decrease in contrast with wavelength was observed in scattering images

Time and Place as Modifiers of Personal UV Exposure

Directory of Open Access Journals (Sweden)

Brian L. Diffey

2018-05-01

Full Text Available It is a common belief that, if we want to limit our sun exposure during outdoor recreational activities and holidays in order to avoid sunburn or reduce our risk of skin cancer, we need to reach for the bottle of sunscreen or cover up with clothing. As important as these measures are, there is another way to enjoy our time outdoors and still benefit from the experience. In this article, we consider the impact of time, place, and behaviour outdoors on our exposure to solar ultraviolet (UV radiation. Some of the simple actions we can take in controlling our UV exposure include being aware of the position of the sun in the sky, understanding how we can use the UV index to guide our outdoor exposure, and the importance of reducing our sun exposure around the middle of the day. Finally we review our preferred holiday activities and destinations, and the influence of outdoor leisure pursuits. By planning where and when we spend our leisure time in the sun, we can maximise our enjoyment whilst limiting our UV exposure.

Time and Place as Modifiers of Personal UV Exposure.

Science.gov (United States)

Diffey, Brian L

2018-05-30

It is a common belief that, if we want to limit our sun exposure during outdoor recreational activities and holidays in order to avoid sunburn or reduce our risk of skin cancer, we need to reach for the bottle of sunscreen or cover up with clothing. As important as these measures are, there is another way to enjoy our time outdoors and still benefit from the experience. In this article, we consider the impact of time, place, and behaviour outdoors on our exposure to solar ultraviolet (UV) radiation. Some of the simple actions we can take in controlling our UV exposure include being aware of the position of the sun in the sky, understanding how we can use the UV index to guide our outdoor exposure, and the importance of reducing our sun exposure around the middle of the day. Finally we review our preferred holiday activities and destinations, and the influence of outdoor leisure pursuits. By planning where and when we spend our leisure time in the sun, we can maximise our enjoyment whilst limiting our UV exposure.

Real-time personal exposure and health condition monitoring system

Energy Technology Data Exchange (ETDEWEB)

Saitou, Isamu; Kanda, Hiroaki; Asai, Akio; Takeishi, Naoki; Ota, Yoshito [Hitachi Aloka Medical, Ltd., Measuring Systems Engineering Dept., Tokyo (Japan); Hanawa, Nobuhiro; Ueda, Hisao; Kusunoki, Tsuyoshi; Ishitsuka, Etsuo; Kawamura, Hiroshi [Japan Atomic Energy Agency, Oarai Research and Development Center, Oarai, Ibaraki (Japan)

2012-03-15

JAEA (Japan Atomic Energy Agency) and HAM (Hitachi Aloka Medical, Ltd) have proposed novel monitoring system for workers of nuclear facility. In these facilities, exposure management for workers is mainly used access control and personal exposure recordings. This system is currently only for reports management but is not confirmative for surveillance when work in progress. Therefore, JAEA and HAM integrate access control and personal exposure recordings and two real-time monitoring systems which are position sensing and vital sign monitor. Furthermore change personal exposure management to real-time management, this system integration prevents workers from risk of accidents, and makes possible take appropriate action quickly. This novel system is going to start for tentative operation, using position sensing and real-time personal dosimeter with database in Apr. 2012. (author)

Radiographic apparatus and method for monitoring film exposure time

International Nuclear Information System (INIS)

Vatne, R.S.; Woodmansee, W.E.

1981-01-01

In connection with radiographic inspection of structural and industrial materials, method and apparatus are disclosed for automatically determining and displaying the time required to expose a radiographic film positioned to receive radiation passed by a test specimen, so that the finished film is exposed to an optimum blackening (density) for maximum film contrast. A plot is made of the variations in a total exposure parameter (representing the product of detected radiation rate and time needed to cause optimum film blackening) as a function of the voltage level applied to an X-ray tube. An electronic function generator storing the shape of this plot is incorporated into an exposure monitoring apparatus, such that for a selected tube voltage setting, the function generator produces an electrical analog signal of the corresponding exposure parameter. During the exposure, another signal is produced representing the rate of radiation as monitored by a diode detector positioned so as to receive the same radiation that is incident on the film. The signal representing the detected radiation rate is divided, by an electrical divider circuit into the signal representing total exposure, and the resulting quotient is an electrical signal representing the required exposure time. (author)

Representativeness of shorter measurement sessions in long-term indoor air monitoring.

Science.gov (United States)

Maciejewska, M; Szczurek, A

2015-02-01

Indoor air quality (IAQ) considerably influences health, comfort and the overall performance of people who spend most of their lives in confined spaces. For this reason, there is a strong need to develop methods for IAQ assessment. The fundamental issue in the quantitative determination of IAQ is the duration of measurements. Its inadequate choice may result in providing incorrect information and this potentially leads to wrong conclusions. The most complete information may be acquired through long-term monitoring. However it is typically perceived as impractical due to time and cost load. The aim of this study was to determine whether long-term monitoring can be adequately represented by a shorter measurement session. There were considered three measurable quantities: temperature, relative humidity and carbon dioxide concentration. They are commonly recognized as indicatives for IAQ and may be readily monitored. Scaled Kullback-Leibler divergence, also called relative entropy, was applied as a measure of data representativeness. We considered long-term monitoring in a range from 1 to 9 months. Based on our work, the representative data on CO2 concentration may be acquired while performing measurements during 20% of time dedicated to long-term monitoring. In the case of temperature and relative humidity the respective time demand was 50% of long-term monitoring. From our results, in indoor air monitoring strategies, there could be considered shorter measurement sessions, while still collecting data which are representative for long-term monitoring.

[Silicosis and industrial bronchitis by exposure to silica powders and cement].

Science.gov (United States)

Méndez-Vargas, María Martha; Báez-Revueltas, Fabiola Berenice; López-Rojas, Pablo; Tovalín-Ahumada, José Horacio; Zamudio-Lara, José Othón; Marín-Cotoñieto, Irma Araceli; Villeda, Francisco

2013-01-01

to identify the association between the exposure of workers to inorganic dust in a quarry and a cement factory and pulmonary diseases. a transverse study on data from 32 quarry workers (QWs) and 57 cement production line workers (CFWs) to inorganic-dust exposure was performed. Pulmonary function tests and chest X ray were done in both groups. there were differences between QWs and the CFWs; QWs were younger, shorter and thinner. The number of sick individuals might be considered significantly different, showing a smaller proportion on the cement production line. The quarry workers have been on the company for a shorter period of time and, in the end, they present more serious pulmonary problems with an average of 3 years working. the amount of free-silica that is managed on the quarry affects the workers in some way, even when literature states that the evolution of industrial bronchitis and silicosis have a period development of approximately 10 years.

High Numbers of Stromal Cancer-Associated Fibroblasts Are Associated With a Shorter Survival Time in Cats With Oral Squamous Cell Carcinoma.

Science.gov (United States)

Klobukowska, H J; Munday, J S

2016-11-01

Cancer-associated fibroblasts (CAFs) are fibroblastic cells that express α-smooth muscle actin and have been identified in the stroma of numerous epithelial tumors. The presence of CAFs within the tumor stroma has been associated with a poorer prognosis in some human cancers, including oral squamous cell carcinomas (SCCs). Cats frequently develop oral SCCs, and although these are generally highly aggressive neoplasms, there is currently a lack of prognostic markers for these tumors. The authors investigated the prognostic value of the presence of CAFs within the stroma of oral SCC biopsy specimens from 47 cats. In addition, several epidemiologic, clinical, and histologic variables were also assessed for prognostic significance. A CAF-positive stroma was identified in 35 of 47 SCCs (74.5%), and the median survival time (ST) of cats with CAF-positive SCCs (35 days) was significantly shorter than that of cats with CAF-negative SCCs (48.5 days) (P = .031). ST was also associated with the location of the primary tumor (P = .0018): the median ST for oropharyngeal SCCs (179 days) was significantly longer than for maxillary (43.5 days; P = .047), mandibular (42 days; P = .022), and sublingual SCCs (22.5 days; P = .0005). The median ST of sublingual SCCs was also shorter compared with maxillary SCCs (P = .0017). Furthermore, a significant association was identified between site and the presence of stromal CAFs (P = .025). On the basis of this retrospective study, evaluating the tumor stroma for CAFs in feline oral SCC biopsy specimens may be of potential prognostic value. © The Author(s) 2016.

Shorter preschool, leukocyte telomere length is associated with obesity at age 9 in Latino children.

Science.gov (United States)

Kjaer, T W; Faurholt-Jepsen, D; Mehta, K M; Christensen, V B; Epel, E; Lin, J; Blackburn, E; Wojcicki, J M

2018-04-01

The aim of this study was to determine the potential role of leukocyte telomere length as a biomarker for development of childhood obesity in a low-income Latino population. A birth cohort of Latino children (N = 201) in San Francisco (recruited May 2006-May 2007) was followed until age 9 and assessed annually for obesity and dietary intake. Leukocyte telomere length was measured at 4 and 5 years (n = 102) and assessed as a predictor for obesity at age 9, adjusting for known risk factors. Furthermore, leukocyte telomere length at age 4 and 5 was evaluated as a possible mediator of the relationship between excessive sugar-sweetened beverage consumption and obesity at age 9. Shorter leukocyte telomere length in preschoolers was associated with obesity at age 9 (adjusted odds ratio 0.35, 95% confidence interval 0.13-0.94) after adjustment for known risk factors. Telomere length mediated 11% of the relationship between excessive sugar-sweetened beverage consumption and obesity. Shorter leukocyte telomere length may be an indicator of future obesity risk in high-risk populations as it is particularly sensitive to damage from oxidative stress exposure, including those from sugar-sweetened beverages. © 2017 World Obesity Federation.

Female exposure to phthalates and time to pregnancy

DEFF Research Database (Denmark)

Thomsen, Anne Marie L.; Riis, Anders H.; Olsen, Jørn

2017-01-01

STUDY QUESTION: Is female exposure to phthalate metabolites associated with reduced fecundity, as estimated by prolonged time to pregnancy (TTP)? SUMMARY ANSWER: Female exposure to monoethyl phthalate (MEP) but not monobutyl phthalate (MBP), monobenzyl phthalate (MBzP) and monoethylhexyl phthalate...... with prospective data based on 229 women from a Danish cohort of 430 first pregnancy planning couples enrolled in 1992-1994. In 2009, urinary analyses of phthalate metabolites were performed on stored urine samples from this cohort. PARTICIPANTS/MATERIALS, SETTING AND METHODS: We analyzed MEP, MBP, MBzP and MEHP...... to estimate fecundability ratios (FRs) and 95% CI in relation to the average urine metabolite concentration exposure level, controlled for age and BMI, and the time-varying variables smoking and alcohol. MAIN RESULT AND ROLE OF CHANCE: Urinary concentration of MEP was associated with a decreased fecundity...

Channel-Island Connectivity Affects Water Exposure Time Distributions in a Coastal River Delta

Science.gov (United States)

Hiatt, Matthew; Castañeda-Moya, Edward; Twilley, Robert; Hodges, Ben R.; Passalacqua, Paola

2018-03-01

The exposure time is a water transport time scale defined as the cumulative amount of time a water parcel spends in the domain of interest regardless of the number of excursions from the domain. Transport time scales are often used to characterize the nutrient removal potential of aquatic systems, but exposure time distribution estimates are scarce for deltaic systems. Here we analyze the controls on exposure time distributions using a hydrodynamic model in two domains: the Wax Lake delta in Louisiana, USA, and an idealized channel-island complex. In particular, we study the effects of river discharge, vegetation, network geometry, and tides and use a simple model for the fractional removal of nitrate. In both domains, we find that channel-island hydrological connectivity significantly affects exposure time distributions and nitrate removal. The relative contributions of the island and channel portions of the delta to the overall exposure time distribution are controlled by island vegetation roughness and network geometry. Tides have a limited effect on the system's exposure time distribution but can introduce significant spatial variability in local exposure times. The median exposure time for the WLD model is 10 h under the conditions tested and water transport within the islands contributes to 37-50% of the network-scale exposure time distribution and 52-73% of the modeled nitrate removal, indicating that islands may account for the majority of nitrate removal in river deltas.

Shorter time since inflammatory bowel disease diagnosis in children is associated with lower mental health in parents.

Science.gov (United States)

Werner, H; Braegger, Cp; Buehr, P; Koller, R; Nydegger, A; Spalinger, J; Heyland, K; Schibli, S; Landolt, Ma

2015-01-01

This study assessed the mental health of parents of children with inflammatory bowel disease (IBD), compared their mental health with age-matched and gender-matched references and examined parental and child predictors for mental health problems. A total of 125 mothers and 106 fathers of 125 children with active and inactive IBD from the Swiss IBD multicentre cohort study were included. Parental mental health was assessed by the Symptom Checklist 27 and child behaviour problems by the Strengths and Difficulties Questionnaire. Child medical data were extracted from hospital records. While the mothers reported lower mental health, the fathers' mental health was similar, or even better, than in age-matched and gender-matched community controls. In both parents, shorter time since the child's diagnosis was associated with poorer mental health. In addition, the presence of their own IBD diagnosis and child behaviour problems predicted maternal mental health problems. Parents of children with IBD may need professional support when their child is diagnosed, to mitigate distress. This, in turn, may help the child to adjust better to IBD. Particular attention should be paid to mothers who have their own IBD diagnosis and whose children display behaviour problems. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Assessment of Nicotine Exposure From Active Human Cigarette Smoking Time

Directory of Open Access Journals (Sweden)

Cahours Xavier

2017-09-01

Full Text Available The burning of a cigarette is a series of consecutive sequences of both passive and active burnings when a smoking cycle is applied to the cigarette. A previous study, using a smoking machine, showed that cigarette nicotine yields are dependent linearly on the difference between the time of smouldering (passive burning and the time of smoking (active burning. It is predicted that the smoker’s nicotine yield increases when the intensity of smoking increases, i.e., when the time to smoke a cigarette (smoking time decreases. Note that observations made on machines might not be comparable to human behaviours. The aim of this study was to determine whether nicotine mouth-level exposure could be predicted through measurement of human smoking time. A smoking behaviour study was conducted to compare human smoking nicotine yields obtained from both filter tip analysis and the cigarette burning time model. Results showed that smokers’ exposure to the smoke depends essentially on the speed at which the cigarette is smoked. An increase in human smoking intensity, resulting in a decrease in smoking time, generates an increase in smoke exposure, whatever the puff number, puff duration, puff volume and filter ventilation (open or blocked. The association of a machine smoking yield with a corresponding smoking time, and the time taken by a consumer to smoke the cigarette would provide information on the exposure to smoke constituents in a simple and effective manner.

Wide-field time-correlated single photon counting (TCSPC) microscopy with time resolution below the frame exposure time

Energy Technology Data Exchange (ETDEWEB)

Hirvonen, Liisa M. [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom); Petrášek, Zdeněk [Max Planck Institute of Biochemistry, Department of Cellular and Molecular Biophysics, Am Klopferspitz 18, D-82152 Martinsried (Germany); Suhling, Klaus, E-mail: klaus.suhling@kcl.ac.uk [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom)

2015-07-01

Fast frame rate CMOS cameras in combination with photon counting intensifiers can be used for fluorescence imaging with single photon sensitivity at kHz frame rates. We show here how the phosphor decay of the image intensifier can be exploited for accurate timing of photon arrival well below the camera exposure time. This is achieved by taking ratios of the intensity of the photon events in two subsequent frames, and effectively allows wide-field TCSPC. This technique was used for measuring decays of ruthenium compound Ru(dpp) with lifetimes as low as 1 μs with 18.5 μs frame exposure time, including in living HeLa cells, using around 0.1 μW excitation power. We speculate that by using an image intensifier with a faster phosphor decay to match a higher camera frame rate, photon arrival time measurements on the nanosecond time scale could well be possible.

Hereditary angioedema attacks resolve faster and are shorter after early icatibant treatment.

Directory of Open Access Journals (Sweden)

Marcus Maurer

Full Text Available BACKGROUND: Attacks of hereditary angioedema (HAE are unpredictable and, if affecting the upper airway, can be lethal. Icatibant is used for physician- or patient self-administered symptomatic treatment of HAE attacks in adults. Its mode of action includes disruption of the bradykinin pathway via blockade of the bradykinin B(2 receptor. Early treatment is believed to shorten attack duration and prevent severe outcomes; however, evidence to support these benefits is lacking. OBJECTIVE: To examine the impact of timing of icatibant administration on the duration and resolution of HAE type I and II attacks. METHODS: The Icatibant Outcome Survey is an international, prospective, observational study for patients treated with icatibant. Data on timings and outcomes of icatibant treatment for HAE attacks were collected between July 2009-February 2012. A mixed-model of repeated measures was performed for 426 attacks in 136 HAE type I and II patients. RESULTS: Attack duration was significantly shorter in patients treated <1 hour of attack onset compared with those treated ≥ 1 hour (6.1 hours versus 16.8 hours [p<0.001]. Similar significant effects were observed for <2 hours versus ≥ 2 hours (7.2 hours versus 20.2 hours [p<0.001] and <5 hours versus ≥ 5 hours (8.0 hours versus 23.5 hours [p<0.001]. Treatment within 1 hour of attack onset also significantly reduced time to attack resolution (5.8 hours versus 8.8 hours [p<0.05]. Self-administrators were more likely to treat early and experience shorter attacks than those treated by a healthcare professional. CONCLUSION: Early blockade of the bradykinin B(2 receptor with icatibant, particularly within the first hour of attack onset, significantly reduced attack duration and time to attack resolution.

Journey-time exposure to particulate air pollution

Science.gov (United States)

Gulliver, John; Briggs, David J.

Journey-time exposures to particulate air pollution were investigated in Leicester, UK, between January and March 2005. Samples of TSP, PM 10, PM 2.5, and PM 1 were simultaneously collected using light scattering devices whilst journeys were made by walking an in-car. Over a period of two months, 33 pairs of walking and in-car measurements were collected along two circular routes. Average exposures while walking were seen to be higher than those found in-car for each of the particle fractions: average walking to in-car ratios were 1.2 (± 0.6), 1.5 (± 0.6), 1.3 (± 0.6), and 1.4 (± 0.6) μg m -3 for coarse (TSP-PM 10), intermediate (PM 10-PM 2.5), fine (PM 2.5-PM 1), and very fine particles (PM 1), respectively. Correlations between walking and in-car exposures were seen to be weak for coarse particles ( r=0.10, p=0.58), moderate for the intermediate particles ( r=0.49, pcar exposures were 25% higher than the same fixed-site monitor. Particles with an aerodynamic diameter of less than 2.5 μm were seen to be highly correlated between walking and in-car particle exposures and a rural fixed-site monitor about 30 km south of Leicester.

Assessing the importance of different exposure metrics and time-activity data to predict 24-H personal PM2.5 exposures.

Science.gov (United States)

Chang, Li-Te; Koutrakis, Petros; Catalano, Paul J; Suh, Helen H

Personal PM(2.5) data from two recent exposure studies, the Scripted Activity Study and the Older Adults Study, were used to develop models predicting 24-h personal PM(2.5) exposures. Both studies were conducted concurrently in the summer of 1998 and the winter of 1999 in Baltimore, MD. In the Scripted Activity Study, 1-h personal PM(2.5) exposures were measured. Data were used to identify significant factors affecting personal exposures and to develop 1-h personal exposure models for five different micro-environments. By incorporating the time-activity diary data, these models were then combined to develop a time-weighted microenvironmental personal model (model M1AD) to predict the 24-h PM(2.5) exposures measured for individuals in the Older Adults Study. Twenty-four-hour time-weighted models were also developed using 1-h ambient PM(2.5) levels and time-activity data (model A1AD) or using 24-h ambient PM(2.5) levels and time-activity data (model A24AD). The performance of these three models was compared to that using 24-h ambient concentrations alone (model A24). Results showed that factors affecting 1-h personal PM(2.5) exposures included air conditioning status and the presence of environmental tobacco smoke (ETS) for indoor micro-environments, consistent with previous studies. ETS was identified as a significant contributor to measured 24-h personal PM(2.5) exposures. Staying in an ETS-exposed microenvironment for 1 h elevated 24-h personal PM(2.5) exposures by approximately 4 microg/m 3 on average. Cooking and washing activities were identified in the winter as significant contributors to 24-h personal exposures as well, increasing 24-h personal PM(2.5) exposures by about 4 and 5 microg/m 3 per hour of activity, respectively. The ability of 3 microenvironmental personal exposure models to estimate 24-h personal PM(2.5) exposures was generally comparable to and consistently greater than that of model A24. Results indicated that using time-activity data with 1

Spindle assembly checkpoint protein expression correlates with cellular proliferation and shorter time to recurrence in ovarian cancer.

LENUS (Irish Health Repository)

McGrogan, Barbara

2014-07-01

Ovarian carcinoma (OC) is the most lethal of the gynecological malignancies, often presenting at an advanced stage. Treatment is hampered by high levels of drug resistance. The taxanes are microtubule stabilizing agents, used as first-line agents in the treatment of OC that exert their apoptotic effects through the spindle assembly checkpoint. BUB1-related protein kinase (BUBR1) and mitotic arrest deficient 2 (MAD2), essential spindle assembly checkpoint components, play a key role in response to taxanes. BUBR1, MAD2, and Ki-67 were assessed on an OC tissue microarray platform representing 72 OC tumors of varying histologic subtypes. Sixty-one of these patients received paclitaxel and platinum agents combined; 11 received platinum alone. Overall survival was available for all 72 patients, whereas recurrence-free survival (RFS) was available for 66 patients. Increased BUBR1 expression was seen in serous carcinomas, compared with other histologies (P = .03). Increased BUBR1 was significantly associated with tumors of advanced stage (P = .05). Increased MAD2 and BUBR1 expression also correlated with increased cellular proliferation (P < .0002 and P = .02, respectively). Reduced MAD2 nuclear intensity was associated with a shorter RFS (P = .03), in ovarian tumors of differing histologic subtype (n = 66). In this subgroup, for those women who received paclitaxel and platinum agents combined (n = 57), reduced MAD2 intensity also identified women with a shorter RFS (P < .007). For the entire cohort of patients, irrespective of histologic subtype or treatment, MAD2 nuclear intensity retained independent significance in a multivariate model, with tumors showing reduced nuclear MAD2 intensity identifying patients with a poorer RFS (P = .05).

Extending 3D near-cloud corrections from shorter to longer wavelengths

International Nuclear Information System (INIS)

Marshak, Alexander; Evans, K. Frank; Várnai, Tamás; Wen, Guoyong

2014-01-01

Satellite observations have shown a positive correlation between cloud amount and aerosol optical thickness (AOT) that can be explained by the humidification of aerosols near clouds, and/or by cloud contamination by sub-pixel size clouds and the cloud adjacency effect. The last effect may substantially increase reflected radiation in cloud-free columns, leading to overestimates in the retrieved AOT. For clear-sky areas near boundary layer clouds the main contribution to the enhancement of clear sky reflectance at shorter wavelengths comes from the radiation scattered into clear areas by clouds and then scattered to the sensor by air molecules. Because of the wavelength dependence of air molecule scattering, this process leads to a larger reflectance increase at shorter wavelengths, and can be corrected using a simple two-layer model [18]. However, correcting only for molecular scattering skews spectral properties of the retrieved AOT. Kassianov and Ovtchinnikov [9] proposed a technique that uses spectral reflectance ratios to retrieve AOT in the vicinity of clouds; they assumed that the cloud adjacency effect influences the spectral ratio between reflectances at two wavelengths less than it influences the reflectances themselves. This paper combines the two approaches: It assumes that the 3D correction for the shortest wavelength is known with some uncertainties, and then it estimates the 3D correction for longer wavelengths using a modified ratio method. The new approach is tested with 3D radiances simulated for 26 cumulus fields from Large-Eddy Simulations, supplemented with 40 aerosol profiles. The results showed that (i) for a variety of cumulus cloud scenes and aerosol profiles over ocean the 3D correction due to cloud adjacency effect can be extended from shorter to longer wavelengths and (ii) the 3D corrections for longer wavelengths are not very sensitive to unbiased random uncertainties in the 3D corrections at shorter wavelengths. - Highlights: �

Study of the examination times using radiation equipments and the radiation exposure control

Energy Technology Data Exchange (ETDEWEB)

Koshida, Kichiro; Orito, Takeo; Maekawa, Ryuichi; Hiraki, Tatsunosuke [Kanazawa Univ. (Japan). School of Paramedicine; Koga, Sukehiko

1985-01-01

The relation between the examination time and the exposure to the personnel was investigated. In order to minimize radiation injury, special exposure dose-rate distribution curves were performed at the maximum exposure condition setting the phantom, and the examination times could be limited from the exprosure dose for the place where the personnel presented. The examination times are possible to be ten times by those with the Medical X-ray Protective Aprons.

Exposure influences expressive timing judgments in music

NARCIS (Netherlands)

Honing, H.; Ladinig, O.

2009-01-01

This study is concerned with the question whether, and to what extent, listeners' previous exposure to music in everyday life, and expertise as a result of formal musical training, play a role in making expressive timing judgments in music. This was investigated by using a Web-based listening

Surgery for subacromial impingement syndrome in relation to intensities of occupational mechanical exposures across 10-year exposure time windows.

Science.gov (United States)

Dalbøge, Annett; Frost, Poul; Andersen, Johan Hviid; Svendsen, Susanne Wulff

2018-03-01

We aimed to identify intensities of occupational mechanical exposures (force, arm elevation and repetition) that do not entail an increased risk of surgery for subacromial impingement syndrome (SIS) even after prolonged durations of exposure. Additionally, we wanted to evaluate if exposure to hand-arm vibration (HAV) is an independent risk factor. We used data from a register-based cohort study of the entire Danish working population (n=2 374 403). During follow-up (2003-2008), 14 118 first-time events of surgery for SIS occurred. For each person, we linked register-based occupational codes (1993-2007) to a general population job exposure matrix to obtain year-by-year exposure intensities on measurement scales for force, upper arm elevation >90° and repetition and expert rated intensities of exposure to HAV. For 10-year exposure time windows, we calculated the duration of exposure at specific intensities above minimal (low, medium and high). We used a logistic regression technique equivalent to discrete survival analysis adjusting for cumulative effects of other mechanical exposures. We found indications of safe exposure intensities for repetition (median angular velocity 90° >2 min/day implied an increased risk reaching ORs of 1.7 and 1.5 after 10 years at low intensities. No associations were found for HAV. We found indications of safe exposure intensities for repetition. Any intensities of force and upper arm elevation >90° above minimal implied an increased risk across 10-year exposure time windows. No independent associations were found for HAV. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Association of Light Exposure on Physical Activity and Sedentary Time in Young People

Directory of Open Access Journals (Sweden)

Daniel Aggio

2015-03-01

Full Text Available Background: To investigate whether light exposure was associated with objectively measured physical activity (PA and sedentary behaviour in young people. Methods: Participants (n = 229, 46.7% female were young people (mean 8.8 years [SD ± 2.2] from the borough of Camden, UK. Daily sedentary time, moderate and vigorous PA (MVPA and light exposure were measured using a tri-axial accelerometer with an ambient light sensor during the summer. Multiple linear regression models examined associations between average daily light exposure, sedentary time and time in MVPA. Models were repeated investigating weekdays and weekend days separately. Analyses were adjusted for pre-specified covariables, including age, sex, device wear time, ethnic group, school and body fat. Results: There were significant associations between average daily light exposure and time sedentary (β coefficient = −11.2, 95% CI, −19.0 to −3.4 and in MVPA (β coefficient = 3.5, 95% CI, 1.2 to 5.9. Light exposure was significantly associated with weekend sedentary time (β coefficient = −10.0, 95% CI, −17.6, −2.4, weekend MVPA (β coefficient = 3.7, 95% CI, 1.7, 5.7, weekday sedentary time (β coefficient = −15.0, 95% CI, −22.7 to −7.2, but not weekday MVPA (β coefficient = 2.0, 95% CI, −0.5 to 4.5. Conclusion: Average daily light exposure is positively associated with time in MVPA and negatively associated with sedentary time. Increasing daylight exposure may be a useful intervention strategy for promoting physical activity.

Study of the examination times using radiation equipments and the radiation exposure control

International Nuclear Information System (INIS)

Koshida, Kichiro; Orito, Takeo; Maekawa, Ryuichi; Hiraki, Tatsunosuke; Koga, Sukehiko.

1985-01-01

It was investigated for the relation between the examination times and the exposure to the personnel. At the purpose to minimize the radiation injury, the special exposure dose-rate distribution curves were performed at the maximum exposure condition setting the phantom, and the examination times could be limited from the exprosure dose for the place where the personnel presented. The examination times are possible to be ten times by those with the Medical X-ray Protective Aprons. (author)

Lagged kernel machine regression for identifying time windows of susceptibility to exposures of complex mixtures.

Science.gov (United States)

Liu, Shelley H; Bobb, Jennifer F; Lee, Kyu Ha; Gennings, Chris; Claus Henn, Birgit; Bellinger, David; Austin, Christine; Schnaas, Lourdes; Tellez-Rojo, Martha M; Hu, Howard; Wright, Robert O; Arora, Manish; Coull, Brent A

2018-07-01

The impact of neurotoxic chemical mixtures on children's health is a critical public health concern. It is well known that during early life, toxic exposures may impact cognitive function during critical time intervals of increased vulnerability, known as windows of susceptibility. Knowledge on time windows of susceptibility can help inform treatment and prevention strategies, as chemical mixtures may affect a developmental process that is operating at a specific life phase. There are several statistical challenges in estimating the health effects of time-varying exposures to multi-pollutant mixtures, such as: multi-collinearity among the exposures both within time points and across time points, and complex exposure-response relationships. To address these concerns, we develop a flexible statistical method, called lagged kernel machine regression (LKMR). LKMR identifies critical exposure windows of chemical mixtures, and accounts for complex non-linear and non-additive effects of the mixture at any given exposure window. Specifically, LKMR estimates how the effects of a mixture of exposures change with the exposure time window using a Bayesian formulation of a grouped, fused lasso penalty within a kernel machine regression (KMR) framework. A simulation study demonstrates the performance of LKMR under realistic exposure-response scenarios, and demonstrates large gains over approaches that consider each time window separately, particularly when serial correlation among the time-varying exposures is high. Furthermore, LKMR demonstrates gains over another approach that inputs all time-specific chemical concentrations together into a single KMR. We apply LKMR to estimate associations between neurodevelopment and metal mixtures in Early Life Exposures in Mexico and Neurotoxicology, a prospective cohort study of child health in Mexico City.

Effects of magnetic field exposure on open field behaviour and nociceptive responses in mice.

Science.gov (United States)

Del Seppia, Cristina; Mezzasalma, Lorena; Choleris, Elena; Luschi, Paolo; Ghione, Sergio

2003-09-15

Results of previous studies have shown that nociceptive sensitivity in male C57 mice is enhanced by exposure to a regular 37 Hz or an irregularly varying (field. In order to test whether these fields affect more generally mouse behaviour, we placed Swiss CD-1 mice in a novel environment (open field test) and exposed them for 2 h to these two different magnetic field conditions. Hence, we analysed how duration and time course of various behavioural patterns (i.e. exploration, rear, edge chew, self-groom, sit, walk and sleep) and nociceptive sensitivity had been affected by such exposure. Nociceptive sensitivity was significantly greater in magnetically treated mice than in controls. The overall time spent in exploratory activities was significantly shorter in both magnetically treated groups (time), than in controls (42%). Conversely, the time spent in sleeping was markedly longer in the treated groups (both 27% of total time) than in controls (11%). These results suggest that exposure to altered magnetic fields induce a more rapid habituation to a novel environment.

Exposure Influences Expressive Timing Judgments in Music

Science.gov (United States)

Honing, Henkjan; Ladinig, Olivia

2009-01-01

This study is concerned with the question whether, and to what extent, listeners' previous exposure to music in everyday life, and expertise as a result of formal musical training, play a role in making expressive timing judgments in music. This was investigated by using a Web-based listening experiment in which listeners with a wide range of…

Shorter Perceived Outpatient MRI Wait Times Associated With Higher Patient Satisfaction.

Science.gov (United States)

Holbrook, Anna; Glenn, Harold; Mahmood, Rabia; Cai, Qingpo; Kang, Jian; Duszak, Richard

2016-05-01

The aim of this study was to assess differences in perceived versus actual wait times among patients undergoing outpatient MRI examinations and to correlate those times with patient satisfaction. Over 15 weeks, 190 patients presenting for outpatient MR in a radiology department in which "patient experience" is one of the stated strategic priorities were asked to (1) estimate their wait times for various stages in the imaging process and (2) state their satisfaction with their imaging experience. Perceived times were compared with actual electronic time stamps. Perceived and actual times were compared and correlated with standardized satisfaction scores using Kendall τ correlation. The mean actual wait time between patient arrival and examination start was 53.4 ± 33.8 min, whereas patients perceived a mean wait time of 27.8 ± 23.1 min, a statistically significant underestimation of 25.6 min (P perceived wait times at all points during patient encounters were correlated with higher satisfaction scores (P perceived and actual wait times were both correlated with higher satisfaction scores. As satisfaction surveys play a larger role in an environment of metric transparency and value-based payments, better understanding of such factors will be increasingly important. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

The relationships between short-term exposure to particulate matter and mortality in Korea: impact of particulate matter exposure metrics for sub-daily exposures

International Nuclear Information System (INIS)

Son, Ji-Young; Bell, Michelle L

2013-01-01

Most studies of short-term particulate matter (PM) exposure use 24 h averages. However, other pollutants have stronger effects in shorter timeframes, which has influenced policy (e.g., ozone 8 h maximum). The selection of appropriate exposure timeframes is important for effective regulation. The US EPA identified health effects for sub-daily PM exposures as a critical research need. Unlike most areas, Seoul, Korea has hourly measurements of PM 10 , although not PM 2.5 . We investigated PM 10 and mortality (total, cardiovascular, respiratory) in Seoul (1999–2009) considering sub-daily exposures: 24 h, daytime (7 am–8 pm), morning (7–10 am), nighttime (8 pm–7 am), and 1 h daily maximum. We applied Poisson generalized linear modeling adjusting for temporal trends and meteorology. All PM 10 metrics were significantly associated with total mortality. Compared to other exposure timeframes, morning exposure had the most certain effect on total mortality (based on statistical significance). Increases of 10 μg m −3 in 24 h, daytime, morning, nighttime, and 1 h maximum PM 10 were associated with 0.15% (95% confidence interval 0.02–0.28%), 0.14% (0.01–0.27%), 0.10% (0.03–0.18%), 0.12% (0.03–0.22%), and 0.10% (0.00–0.21%) increases in total mortality, respectively. PM 10 was significantly associated with cardiovascular mortality for 24 h, morning, and nighttime exposures. We did not identify significant associations with respiratory mortality. The results support use of a 24 h averaging time as an appropriate metric for health studies and regulation, particularly for PM 10 and mortality. (letter)

Odors: appetizing or satiating? Development of appetite during odor exposure over time.

Science.gov (United States)

Ramaekers, M G; Boesveldt, S; Lakemond, C M M; van Boekel, M A J S; Luning, P A

2014-05-01

Exposure to palatable food odors influences appetite responses, either promoting or inhibiting food intake. Possibly, food odors are appetizing after a short exposure (of circa 1-3 min), but become satiating over time (circa 10-20 min). To investigate the effect of odor exposure on general appetite and sensory-specific appetite (SSA) over time. In a cross-over study, 21 unrestrained women (age: 18-45 years; BMI: 18.5-25 kg m(-2)) were exposed for 20 min to eight different odor types: five food odors, two nonfood odors and no-odor. All odors were distributed in a test room at suprathreshold levels. General appetite, SSA and salivation were measured over time. All food odors significantly increased general appetite and SSA, compared with the no-odor condition. The nonfood odors decreased general appetite. All effects did not change over time during odor exposure. Savory odors increased the appetite for savory foods, but decreased appetite for sweet foods, and vice versa after exposure to sweet odors. Neither food odors nor nonfood odors affected salivation. Palatable food odors were appetizing during and after odor exposure and did not become satiating over a 20-min period. Food odors had a large impact on SSA and a small impact on general appetite. Moreover, exposure to food odors increased the appetite for congruent foods, but decreased the appetite for incongruent foods. It may be hypothesized that, once the body is prepared for intake of a certain food with a particular macronutrient composition, it is unfavorable to consume foods that are very different from the cued food.

Shorter daily dwelling time in peritoneal dialysis attenuates the epithelial-to-mesenchymal transition of mesothelial cells

Science.gov (United States)

2014-01-01

Background Peritoneal dialysis (PD) therapy is known to induce morphological and functional changes in the peritoneal membrane. Long-term exposure to conventional bio-incompatible dialysate and peritonitis is the main etiology of inflammation. Consequently, the peritoneal membrane undergoes structural changes, including angiogenesis, fibrosis, and hyalinizing vasculopathy, which ultimately results in technique failure. The epithelial-to-mesenchymal transition (EMT) of mesothelial cells (MCs) plays an important role during the above process; however, the clinical parameters associated with the EMT process of MCs remain to be explored. Methods To investigate the parameters impacting EMT during PD therapy, 53 clinical stable PD patients were enrolled. EMT assessments were conducted through human peritoneal MCs cultured from dialysate effluent with one consistent standard criterion (MC morphology and the expression of an epithelial marker, cytokeratin 18). The factors potentially associated with EMT were analyzed using logistic regression analysis. Primary MCs derived from the omentum were isolated for the in vitro study. Results Forty-seven percent of the patients presented with EMT, 28% with non-EMT, and 15% with a mixed presentation. Logistic regression analysis showed that patients who received persistent PD therapy (dwelling time of 24 h/day) had significantly higher EMT tendency. These results were consistent in vitro. Conclusions Dwelling time had a significant effect on the occurrence of EMT on MCs. PMID:24555732

[Solar exposure time for sunburn in Mexican population].

Science.gov (United States)

Castanedo Cázares, Juan Pablo; Torres Álvarez, Bertha; Sobrevilla Ondarza, Salvador; Ehnis Pérez, Adriana; Gordillo Moscoso, Antonio

2012-01-01

THe minimal erythemal dose (MED) quantifies an individual's sensitivity to UV radiation (UVR). To estimate it in our population and establish the time of exposure inducing it during daily activities would allow us to calculate risk intervals. From 2005-2012, the UV solar radiation was measured with terrestrial radiometry and compared to public UV index (UVI). We determined the MED in 90 individuals with the prevalent phototypes in Mexico (III, IV, V), and estimated the time needed for the development of sunburn. The average MED for phototype III was 39 (IC 95%: 35-42) mJ/cm2, for IV 48 (IC 95%:42-53) mJ/cm2, and for V was 84 (IC 95%:75-92) mJ/cm2 (ANOVA, p ≤ 0.001). Approximately, 80% of the daily UVR was accumulated between 10:00-16:00 h, and 77% of the annual UV dose is received between March-October. The public UVI had a high correlation with the one quantified at terrestrial level (r = 0.89; p ≤ 0.001). Mexico receives continuously high levels of UVR. Phototype III will present sunburn after 22-33 min in a summer day, while phototype V will require over one hour of exposure. This last group is at risk of chronic exposure without considering consequences.

Effects of post exposure bake temperature and exposure time on SU-8 nanopattern obtained by electron beam lithography

Science.gov (United States)

Yasui, Manabu; Kazawa, Elito; Kaneko, Satoru; Takahashi, Ryo; Kurouchi, Masahito; Ozawa, Takeshi; Arai, Masahiro

2014-11-01

SU-8 is a photoresist imaged using UV rays. However, we investigated the characteristics of an SU-8 nanopattern obtained by electron beam lithography (EBL). In particular, we studied the relationship between post-exposure bake (PEB) temperature and exposure time on an SU-8 nanopattern with a focus on phase transition temperature. SU-8 residue was formed by increasing both PEB temperature and exposure time. To prevent the formation of this, Monte Carlo simulation was performed; the results of such simulation showed that decreasing the thickness of SU-8 can reduce the amount of residue from the SU-8 nanopattern. We confirmed that decreasing the thickness of SU-8 can also prevent the formation of residue from the SU-8 nanopattern with EBL.

Assessment of the vaginal residence time of biomarkers of semen exposure.

Science.gov (United States)

Thurman, Andrea; Jacot, Terry; Melendez, Johan; Kimble, Thomas; Snead, Margaret; Jamshidi, Roxanne; Wheeless, Angie; Archer, David F; Doncel, Gustavo F; Mauck, Christine

2016-11-01

The primary objective of this pilot study is to determine and compare the residence time in the vagina of biomarkers of semen exposure for up to 15 days post exposure. The biomarkers are prostate-specific antigen (PSA), Y chromosome DNA, the sex determining region of the Y chromosome (SRY) and testis-specific protein Y-encoded 4 (TSPY4). The secondary objectives are to determine if biomarker concentrations differed between intercourse and inoculation groups, to establish whether the sampling frequency post exposure affected biomarker concentrations and decay profile and to determine if biomarker concentrations in vaginal swabs obtained by the participant at home were similar to swabs obtained by the nurse in the clinic. We randomized healthy women to unprotected intercourse (n=17) versus vaginal inoculation with the male partner's semen in the clinic (n=16). Women were then further randomized to have vaginal swabs obtained at either 7 or 4 time points after semen exposure, up to 15 days post exposure, either obtained at home by the participant or in the clinic by the research nurse. PSA and SRY were markers of recent semen exposure. TSPY4 was detectable in approximately 50% of participants at 15 days post exposure. Unprotected intercourse resulted in significantly higher concentrations of select biomarkers. Sampling frequency and home versus clinic sampling had no significant effect on biomarker concentrations. Objective biomarkers of recent or distant semen exposure may have great utility for verifying protocol compliance in a variety of clinical trials. Copyright © 2016 Elsevier Inc. All rights reserved.

Investigations of model polymers: Dynamics of melts and statics of a long chain in a dilute melt of shorter chains

International Nuclear Information System (INIS)

Bishop, M.; Ceperley, D.; Frisch, H.L.; Kalos, M.H.

1982-01-01

We report additional results on a simple model of polymers, namely the diffusion in concentrated polymer systems and the static properties of one long chain in a dilute melt of shorter chains. It is found, for the polymer sizes and time scales amenable to our computer calculations, that there is as yet no evidence for a ''reptation'' regime in a melt. There is some indication of reptation in the case of a single chain moving through fixed obstacles. No statistically significant effect of the change, from excluded volume behavior of the long chain to ideal behavior as the shorter chains grow, is observed

How to statistically analyze nano exposure measurement results: using an ARIMA time series approach

International Nuclear Information System (INIS)

Klein Entink, Rinke H.; Fransman, Wouter; Brouwer, Derk H.

2011-01-01

Measurement strategies for exposure to nano-sized particles differ from traditional integrated sampling methods for exposure assessment by the use of real-time instruments. The resulting measurement series is a time series, where typically the sequential measurements are not independent from each other but show a pattern of autocorrelation. This article addresses the statistical difficulties when analyzing real-time measurements for exposure assessment to manufactured nano objects. To account for autocorrelation patterns, Autoregressive Integrated Moving Average (ARIMA) models are proposed. A simulation study shows the pitfalls of using a standard t-test and the application of ARIMA models is illustrated with three real-data examples. Some practical suggestions for the data analysis of real-time exposure measurements conclude this article.

In Vitro Comparison of Holmium Lasers: Evidence for Shorter Fragmentation Time and Decreased Retropulsion Using a Modern Variable-pulse Laser.

Science.gov (United States)

Bell, John Roger; Penniston, Kristina L; Nakada, Stephen Y

2017-09-01

To compare the performance of variable- and fixed-pulse lasers on stone phantoms in vitro. Seven-millimeter stone phantoms were made to simulate calcium oxalate monohydrate stones using BegoStone plus. The in vitro setting was created with a clear polyvinyl chloride tube. For each trial, a stone phantom was placed at the open end of the tubing. The Cook Rhapsody H-30 variable-pulse laser was tested on both long- and short-pulse settings and was compared to the Dornier H-20 fixed-pulse laser; 5 trials were conducted for each trial arm. Fragmentation was accomplished with the use of a flexible ureteroscope and a 273-micron holmium laser fiber using settings of 1 J × 12 Hz. The treatment time (in minute) for complete fragmentation was recorded as was the total retropulsion distance (in centimeter) during treatment. Laser fibers were standardized for all repetitions. The treatment time was significantly shorter with the H-30 vs the H-20 laser (14.3 ± 2.5 vs 33.1 ± 8.9 minutes, P = .008). There was no difference between the treatment times using the long vs short pulse widths of the H-30 laser (14.4 ± 3.4 vs 14.3 ± 1.7 minutes, P = .93). Retropulsion differed by laser type and pulse width, H-30 long pulse (15.8 ± 5.7 cm), H-30 short pulse (54.8 ± 7.1 cm), and H-20 (33.2 ± 12.5 cm) (P laser fragmented stone phantoms in half the time of the H-20 laser regardless of the pulse width. Retropulsion effects differed between the lasers, with the H-30 causing the least retropulsion. Longer pulse widths result in less stone retropulsion. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of exposure time reduction towards sensitivity and SNR for computed radiography (CR) application in NDT

International Nuclear Information System (INIS)

Sapizah Rahim; Khairul Anuar Mohd Salleh; Noorhazleena Azaman; Shaharudin Sayuti; Siti Madiha Muhammad Amir; Arshad Yassin; Abdul Razak Hamzah

2010-01-01

Signal-to-noise ratio (SNR) and sensitivity study of Computed Radiography (CR) system with reduction of exposure time is presented. The purposes of this research are to determine the behavior of SNR toward three different thicknesses (step wedge; 5, 10 and 15 mm) and the ability of CR system to recognize hole type penetrameter when the exposure time decreased up to 80 % according to the exposure chart (D7; ISOVOLT Titan E). It is shown that the SNR is decreased with decreasing of exposure time percentage but the high quality image is achieved until 80 % reduction of exposure time. (author)

Shorter height is related to lower cardiovascular disease risk – A narrative review

Directory of Open Access Journals (Sweden)

Thomas T. Samaras

2013-01-01

Full Text Available Numerous Western studies have shown a negative correlation between height and cardiovascular disease. However, these correlations do not prove causation. This review provides a variety of studies showing short people have little to no cardiovascular disease. When shorter people are compared to taller people, a number of biological mechanisms evolve favoring shorter people, including reduced telomere shortening, lower atrial fibrillation, higher heart pumping efficiency, lower DNA damage, lower risk of blood clots, lower left ventricular hypertrophy and superior blood parameters. The causes of increased heart disease among shorter people in the developed world are related to lower income, excessive weight, poor diet, lifestyle factors, catch-up growth, childhood illness and poor environmental conditions. For short people in developed countries, the data indicate that a plant-based diet, leanness and regular exercise can substantially reduce the risk of cardiovascular disease.

Joint analysis of French and Czech uranium miners: lung cancer risk at low radon exposure rates and modifying effects of time since exposure and age at exposure

International Nuclear Information System (INIS)

Ladislav Tomasek; Agnes Rogel; Margot Tirmarche; Dominique Laurier

2006-01-01

The present analysis was conducted in the frame of European project 'Quantification of lung cancer risk after low radon exposure and low exposure rate: synthesis from epidemiologic and experimental data'. The overall goal of the project related to uranium miners was the evaluation of lung cancer dose-response relationship and of dose rate effects among European uranium miners exposed to low doses and low dose rates of radon decay products. In addition, modifying factors like attained age, age at exposure and time since exposure were investigated. The joint analysis of French and Czech uranium miners was conducted mainly in order to increase the statistical power and to allow a more detailed description of the variation of dose-response relationship in time. (N.C.)

Joint analysis of French and Czech uranium miners: lung cancer risk at low radon exposure rates and modifying effects of time since exposure and age at exposure

Energy Technology Data Exchange (ETDEWEB)

Ladislav Tomasek [National Radiation Protection Institute, Prague (Czech Republic); Agnes Rogel; Margot Tirmarche; Dominique Laurier [Institut de Radioprotection et de Surete Nucleaire, Fontenay-aux-Roses (France)

2006-07-01

The present analysis was conducted in the frame of European project 'Quantification of lung cancer risk after low radon exposure and low exposure rate: synthesis from epidemiologic and experimental data'. The overall goal of the project related to uranium miners was the evaluation of lung cancer dose-response relationship and of dose rate effects among European uranium miners exposed to low doses and low dose rates of radon decay products. In addition, modifying factors like attained age, age at exposure and time since exposure were investigated. The joint analysis of French and Czech uranium miners was conducted mainly in order to increase the statistical power and to allow a more detailed description of the variation of dose-response relationship in time. (N.C.)

Surgery for subacromial impingement syndrome in relation to intensities of occupational mechanical exposures across 10-year exposure time windows

DEFF Research Database (Denmark)

Dalbøge, Annett; Frost, Poul; Andersen, Johan Hviid

2018-01-01

OBJECTIVES: We aimed to identify intensities of occupational mechanical exposures (force, arm elevation and repetition) that do not entail an increased risk of surgery for subacromial impingement syndrome (SIS) even after prolonged durations of exposure. Additionally, we wanted to evaluate...... if exposure to hand-arm vibration (HAV) is an independent risk factor. METHODS: We used data from a register-based cohort study of the entire Danish working population (n=2 374 403). During follow-up (2003-2008), 14 118 first-time events of surgery for SIS occurred. For each person, we linked register...... of exposure at specific intensities above minimal (low, medium and high). We used a logistic regression technique equivalent to discrete survival analysis adjusting for cumulative effects of other mechanical exposures. RESULTS: We found indications of safe exposure intensities for repetition (median angular...

Left truncation results in substantial bias of the relation between time-dependent exposures and adverse events

NARCIS (Netherlands)

Hazelbag, Christijan M; Klungel, Olaf H; van Staa, Tjeerd P; de Boer, Anthonius; Groenwold, Rolf H H

PURPOSE: To assess the impact of random left truncation of data on the estimation of time-dependent exposure effects. METHODS: A simulation study was conducted in which the relation between exposure and outcome was based on an immediate exposure effect, a first-time exposure effect, or a cumulative

Left truncation results in substantial bias of the relation between time-dependent exposures and adverse events

NARCIS (Netherlands)

Hazelbag, Christijan M.; Klungel, Olaf H.; van Staa, Tjeerd P.; de Boer, Anthonius; Groenwold, Rolf H H

2015-01-01

PURPOSE: To assess the impact of random left truncation of data on the estimation of time-dependent exposure effects. METHODS: A simulation study was conducted in which the relation between exposure and outcome was based on an immediate exposure effect, a first-time exposure effect, or a cumulative

Interactive vs passive screen time and nighttime sleep duration among school-aged children.

Science.gov (United States)

Yland, Jennifer; Guan, Stanford; Emanuele, Erin; Hale, Lauren

2015-09-01

Insufficient sleep among school-aged children is a growing concern, as numerous studies have shown that chronic short sleep duration increases the risk of poor academic performance and specific adverse health outcomes. We examined the association between weekday nighttime sleep duration and 3 types of screen exposure: television, computer use, and video gaming. We used age 9 data from an ethnically diverse national birth cohort study, the Fragile Families and Child Wellbeing Study, to assess the association between screen time and sleep duration among 9-year-olds, using screen time data reported by both the child (n = 3269) and by the child's primary caregiver (n= 2770). Within the child-reported models, children who watched more than 2 hours of television per day had shorter sleep duration by approximately 11 minutes per night compared to those who watched less than 2 hours of television (β = -0.18; P computer use were associated with reduced sleep duration. For both child- and parent-reported screen time measures, we did not find statistically significant differences in effect size across various types of screen time. Screen time from televisions and computers is associated with reduced sleep duration among 9-year-olds, using 2 sources of estimates of screen time exposure (child and parent reports). No specific type or use of screen time resulted in significantly shorter sleep duration than another, suggesting that caution should be advised against excessive use of all screens.

Cosmic radiation exposure of future hypersonic flight missions

International Nuclear Information System (INIS)

Koops, L.

2017-01-01

Cosmic radiation exposure in air traffic grows with flight altitude, geographical latitude and flight time. For future high-speed intercontinental point-to-point travel, the trade-off between reduced flight time and enhanced dose rate at higher flight altitudes is investigated. Various representative (partly) hypersonic cruise missions are considered and in dependence on solar activity the integral route dose is calculated for envisaged flight profiles and trajectories. Our results are compared to those for corresponding air connections served by present day subsonic airliners. During solar maximum, we find a significant reduction in route dose for all considered high-speed missions compared to the subsonic reference. However, during solar minimum, comparable or somewhat larger doses result on transpolar trajectories with (partly) hypersonic cruise at Mach 5. Both solar activity and routing are hence found to determine, whether passengers can profit from shorter flight times in terms of radiation exposure, despite of altitude-induced higher dose rates. Yet, air crews with fixed number of block hours are always subject to larger annual doses, which in the considered cases take values up to five times the reference. We comment on the implications of our results for route planning and aviation decision-making in the absence of radiation shielding solutions. (author)

Duration and Timing of Exposure to Neighborhood Poverty and the Risk of Adolescent Parenthood

Science.gov (United States)

Wodtke, Geoffrey T.

2013-01-01

Theory suggests that the impact of neighborhood poverty depends on both the duration and timing of exposure. Previous research, however, does not properly analyze the sequence of neighborhoods to which children are exposed throughout the early life course. This study investigates the effects of different longitudinal patterns of exposure to disadvantaged neighborhoods on the risk of adolescent parenthood. It follows a cohort of children in the PSID from age 4 to 19 and uses novel methods for time-varying exposures that overcome critical limitations of conventional regression when selection processes are dynamic. Results indicate that sustained exposure to poor neighborhoods substantially increases the risk of becoming a teen parent and that exposure to neighborhood poverty during adolescence may be more consequential than exposure earlier during childhood. PMID:23720166

interactive effect of cowpea variety, dose and exposure time

African Journals Online (AJOL)

ACSS

variety (V), exposure time (T) and dose (D) on the tolerance of C. maculatus to both plant materials. The effect ... laboratories and institutions of higher education in several West .... Each value is the mean±S.E of 20 cowpea seeds. Means ...

Influence of different anoxic time exposures on active biomass, protozoa and filamentous bacteria in activated sludge.

Science.gov (United States)

Rodriguez-Perez, S; Fermoso, F G; Arnaiz, C

Medium-sized wastewater treatment plants are considered too small to implement anaerobic digestion technologies and too large for extensive treatments. A promising option as a sewage sludge reduction method is the inclusion of anoxic time exposures. In the present study, three different anoxic time exposures of 12, 6 and 4 hours have been studied to reduce sewage sludge production. The best anoxic time exposure was observed under anoxic/oxic cycles of 6 hours, which reduced 29.63% of the biomass production compared with the oxic control conditions. The sludge under different anoxic time exposures, even with a lower active biomass concentration than the oxic control conditions, showed a much higher metabolic activity than the oxic control conditions. Microbiological results suggested that both protozoa density and abundance of filamentous bacteria decrease under anoxic time exposures compared to oxic control conditions. The anoxic time exposures 6/6 showed the highest reduction in both protozoa density, 37.5%, and abundance of filamentous bacteria, 41.1%, in comparison to the oxic control conditions. The groups of crawling ciliates, carnivorous ciliates and filamentous bacteria were highly influenced by the anoxic time exposures. Protozoa density and abundance of filamentous bacteria have been shown as promising bioindicators of biomass production reduction.

Child and adolescent exposure to food and beverage brand appearances during prime-time television programming.

Science.gov (United States)

Speers, Sarah E; Harris, Jennifer L; Schwartz, Marlene B

2011-09-01

The food industry disproportionately markets to young people through product placements. Children and adolescents may be more susceptible to these disguised persuasive attempts. Quantify incidence and youth exposure to food and beverage brand appearances within shows on prime-time TV. Data on the number of food, beverage, and restaurant brand appearances within shows during prime-time programming in 2008 were purchased from Nielsen and analyzed by product category and company in 2010. Exposure to these brand appearances by children, adolescents, and adults were examined and compared with exposure to prime-time TV advertisements for the same categories and companies using additional Nielsen data. Food, beverage, and restaurant brands appeared a total of 35,000 times within prime-time TV programming examined by Nielsen in 2008. Regular soft drinks, traditional restaurants (i.e., not quickserve), and energy/sports drinks made up 60% of all brand appearances. Young people viewed relatively few of these appearances with one notable exception. Coca-Cola products were seen 198 times by the average child and 269 times by the average adolescent during prime-time shows over the year, accounting for 70% of child exposure and 61% of adolescent exposure to brand appearances. One show, American Idol, accounted for more than 95% of these exposures. Exposure of children to Coca-Cola products through traditional advertisements was much less common. Brand appearances for most food industry companies, except for Coca-Cola, are relatively rare during prime-time programming with large youth audiences. Coca-Cola has pledged to refrain from advertising to children, yet the average child views almost four Coke appearances on prime-time TV every week. This analysis reveals a substantial, potential loophole in current food industry self-regulatory pledges to advertise only better-for-you foods to children. Copyright © 2011 American Journal of Preventive Medicine. Published by Elsevier Inc

How to statistically analyze nano exposure measurement results: Using an ARIMA time series approach

NARCIS (Netherlands)

Klein Entink, R.H.; Fransman, W.; Brouwer, D.H.

2011-01-01

Measurement strategies for exposure to nano-sized particles differ from traditional integrated sampling methods for exposure assessment by the use of real-time instruments. The resulting measurement series is a time series, where typically the sequential measurements are not independent from each

Exposure Time Distributions reveal Denitrification Rates along Groundwater Flow Path of an Agricultural Unconfined Aquifer

Science.gov (United States)

Kolbe, T.; Abbott, B. W.; Thomas, Z.; Labasque, T.; Aquilina, L.; Laverman, A.; Babey, T.; Marçais, J.; Fleckenstein, J. H.; Peiffer, S.; De Dreuzy, J. R.; Pinay, G.

2016-12-01

Groundwater contamination by nitrate is nearly ubiquitous in agricultural regions. Nitrate is highly mobile in groundwater and though it can be denitrified in the aquifer (reduced to inert N2 gas), this process requires the simultaneous occurrence of anoxia, an electron donor (e.g. organic carbon, pyrite), nitrate, and microorganisms capable of denitrification. In addition to this the ratio of the time groundwater spent in a denitrifying environment (exposure time) to the characteristic denitrification reaction time plays an important role, because denitrification can only occur if the exposure time is longer than the characteristic reaction time. Despite a long history of field studies and numerical models, it remains exceedingly difficult to measure or model exposure times in the subsurface at the catchment scale. To approach this problem, we developed a unified modelling approach combining measured environmental proxies with an exposure time based reactive transport model. We measured groundwater age, nitrogen and sulfur isotopes, and water chemistry from agricultural wells in an unconfined aquifer in Brittany, France, to quantify changes in nitrate concentration due to dilution and denitrification. Field data showed large differences in nitrate concentrations among wells, associated with differences in the exposure time distributions. By constraining a catchment-scale characteristic reaction time for denitrification with water chemistry proxies and exposure times, we were able to assess rates of denitrification along groundwater flow paths. This unified modeling approach is transferable to other catchments and could be further used to investigate how catchment structure and flow dynamics interact with biogeochemical processes such as denitrification.

Bedtime and evening light exposure influence circadian timing in preschool-age children: A field study

Directory of Open Access Journals (Sweden)

Lameese D. Akacem

2016-11-01

Full Text Available Light exposure and sleep timing are two factors that influence inter-individual variability in the timing of the human circadian clock. The aim of this study was to quantify the degree to which evening light exposure predicts variance in circadian timing over and above bedtime alone in preschool children. Participants were 21 children ages 4.5–5.0 years (4.7±0.2 years; 9 females. Children followed their typical sleep schedules for 4 days during which time they wore a wrist actigraph to assess sleep timing and a pendant light meter to measure minute-by-minute illuminance levels in lux. On the 5th day, children participated in an in-home dim-light melatonin onset (DLMO assessment. Light exposure in the 2 h before bedtime was averaged and aggregated across the 4 nights preceding the DLMO assessment. Mean DLMO and bedtime were 19:22±01:04 and 20:07±00:46, respectively. Average evening light exposure was 710.1±1418.2 lux. Children with later bedtimes (lights-off time had more delayed melatonin onset times (r=0.61, p=0.002. Evening light exposure was not independently associated with DLMO (r=0.32, p=0.08; however, a partial correlation between evening light exposure and DLMO when controlling for bedtime yielded a positive correlation (r=0.46, p=0.02. Bedtime explained 37.3% of the variance in the timing of DLMO, and evening light exposure accounted for an additional 13.3% of the variance. These findings represent an important step in understanding factors that influence circadian phase in preschool-age children and have implications for understanding a modifiable pathway that may underlie late sleep timing and the development of evening settling problems in early childhood.

Population exposure to ultraviolet radiation in Finland 1920-1995: Exposure trends and a time-series analysis of exposure and cutaneous melanoma incidence

International Nuclear Information System (INIS)

Kojo, Katja; Jansen, Christer T.; Nybom, Pia; Huurto, Laura; Laihia, Jarmo; Ilus, Taina; Auvinen, Anssi

2006-01-01

Ultraviolet radiation (UVR) is the principal cause of cutaneous malignant melanoma (CMM). However, the relation between CMM and UVR exposure is not clear. We present the trends of population exposure to UVR and conduct a time-series analysis of the relation between UVR exposure and incidence of CMM. Data on CMM incidence were obtained from the Finnish Cancer Registry. Clothing coverage of the body was scored from archival photographs and the proportion of uncovered skin was used as a measure of solar exposure. Information on the number of sunny resort holidays, duration of annual holidays, and sunscreen sales were obtained from various sources. Exposed skin area doubled from 1920 to 1985. The average duration of annual holidays increased 30-fold. The number of sunny resort holidays and the sales of sunscreens increased rapidly from 1980. CMM was most strongly associated with solar exposure of 5-19 years earlier. There is a considerable decrease in clothing coverage during the 20th century. UVR exposure preceding CMM occurrence 4 years or less does not appear relevant, whereas the period 5-19 years prior to CMM occurrence might be the most relevant period. However, findings of ecological studies may not be applicable at the individual level

Odors: appetizing or satiating? Development of appetite during odor exposure over time

NARCIS (Netherlands)

Ramaekers, M.G.; Boesveldt, S.; Lakemond, C.M.M.; Boekel, van M.A.J.S.; Luning, P.A.

2014-01-01

Background: Exposure to palatable food odors influences appetite responses, either promoting or inhibiting food intake. Possibly, food odors are appetizing after a short exposure (of circa 1–3¿min), but become satiating over time (circa 10–20¿min). Objective: To investigate the effect of odor

SHORTER MENSTRUAL CYCLES ASSOCIATED WITH CHLORINATION BY-PRODUCTS IN DRINKING WATER

Science.gov (United States)

Shorter Menstrual Cycles Associated with Chlorination by-Products in Drinking Water. Gayle Windham, Kirsten Waller, Meredith Anderson, Laura Fenster, Pauline Mendola, Shanna Swan. California Department of Health Services.In previous studies of tap water consumption we...

Can pre-season fitness measures predict time to injury in varsity athletes?: a retrospective case control study

Directory of Open Access Journals (Sweden)

Kennedy Michael D

2012-07-01

Full Text Available Abstract Background The ability to determine athletic performance in varsity athletes using preseason measures has been established. The ability of pre-season performance measures and athlete’s exposure to predict the incidence of injuries is unclear. Thus our purpose was to determine the ability of pre-season measures of athletic performance to predict time to injury in varsity athletes. Methods Male and female varsity athletes competing in basketball, volleyball and ice hockey participated in this study. The main outcome measures were injury prevalence, time to injury (based on calculated exposure and pre-season fitness measures as predictors of time to injury. Fitness measures were Apley’s range of motion, push-up, curl-ups, vertical jump, modified Illinois agility, and sit-and-reach. Cox regression models were used to identify which baseline fitness measures were predictors of time to injury. Results Seventy-six percent of the athletes reported 1 or more injuries. Mean times to initial injury were significantly different for females and males (40.6% and 66.1% of the total season (p , respectively. A significant univariate correlation was observed between push-up performance and time to injury (Pearson’s r = 0.332, p . No preseason fitness measure impacted the hazard of injury. Regardless of sport, female athletes had significantly shorter time to injury than males (Hazard Ratio = 2.2, p . Athletes playing volleyball had significantly shorter time to injury (Hazard Ratio = 4.2, p  compared to those playing hockey or basketball. Conclusions When accounting for exposure, gender, sport and fitness measures, prediction of time to injury was influenced most heavily by gender and sport.

Effects of day-time exposure to different light intensities on light-induced melatonin suppression at night.

Science.gov (United States)

Kozaki, Tomoaki; Kubokawa, Ayaka; Taketomi, Ryunosuke; Hatae, Keisuke

2015-07-04

Bright nocturnal light has been known to suppress melatonin secretion. However, bright light exposure during the day-time might reduce light-induced melatonin suppression (LIMS) at night. The effective proportion of day-time light to night-time light is unclear; however, only a few studies on accurately controlling both day- and night-time conditions have been conducted. This study aims to evaluate the effect of different day-time light intensities on LIMS. Twelve male subjects between the ages of 19 and 23 years (mean ± S.D., 20.8 ± 1.1) gave informed consent to participate in this study. They were exposed to various light conditions (day-time light conditions). They were then exposed to bright light (300 lx) again between 01:00 and 02:30 (night-time light exposure). They provided saliva samples before (00:55) and after night-time light exposure (02:30). A one-tailed paired t test yielded significant decrements of melatonin concentration after night-time light exposure under day-time dim, 100- and 300-lx light conditions. No significant differences exist in melatonin concentration between pre- and post-night-time light exposure under day-time 900- and 2700-lx light conditions. Present findings suggest the amount of light exposure needed to prevent LIMS caused by ordinary nocturnal light in individuals who have a general life rhythm (sleep/wake schedule). These findings may be useful in implementing artificial light environments for humans in, for example, hospitals and underground shopping malls.

Integration of image exposure time into a modified laser speckle imaging method

Energy Technology Data Exchange (ETDEWEB)

RamIrez-San-Juan, J C; Salazar-Hermenegildo, N; Ramos-Garcia, R; Munoz-Lopez, J [Optics Department, INAOE, Puebla (Mexico); Huang, Y C [Department of Electrical Engineering and Computer Science, University of California, Irvine, CA (United States); Choi, B, E-mail: jcram@inaoep.m [Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA (United States)

2010-11-21

Speckle-based methods have been developed to characterize tissue blood flow and perfusion. One such method, called modified laser speckle imaging (mLSI), enables computation of blood flow maps with relatively high spatial resolution. Although it is known that the sensitivity and noise in LSI measurements depend on image exposure time, a fundamental disadvantage of mLSI is that it does not take into account this parameter. In this work, we integrate the exposure time into the mLSI method and provide experimental support of our approach with measurements from an in vitro flow phantom.

Integration of image exposure time into a modified laser speckle imaging method

International Nuclear Information System (INIS)

RamIrez-San-Juan, J C; Salazar-Hermenegildo, N; Ramos-Garcia, R; Munoz-Lopez, J; Huang, Y C; Choi, B

2010-01-01

Speckle-based methods have been developed to characterize tissue blood flow and perfusion. One such method, called modified laser speckle imaging (mLSI), enables computation of blood flow maps with relatively high spatial resolution. Although it is known that the sensitivity and noise in LSI measurements depend on image exposure time, a fundamental disadvantage of mLSI is that it does not take into account this parameter. In this work, we integrate the exposure time into the mLSI method and provide experimental support of our approach with measurements from an in vitro flow phantom.

Modeling Exposure to Heat Stress with a Simple Urban Model

Directory of Open Access Journals (Sweden)

Peter Hoffmann

2018-01-01

Full Text Available As a first step in modeling health-related urban well-being (UrbWellth, a mathematical model is constructed that dynamically simulates heat stress exposure of commuters in an idealized city. This is done by coupling the Simple Urban Radiation Model (SURM, which computes the mean radiant temperature ( T m r t , with a newly developed multi-class multi-mode traffic model. Simulation results with parameters chosen for the city of Hamburg for a hot summer day show that commuters are potentially most exposed to heat stress in the early afternoon when T m r t has its maximum. Varying the morphology with respect to street width and building height shows that a more compact city configuration reduces T m r t and therefore the exposure to heat stress. The impact resulting from changes in the city structure on traffic is simulated to determine the time spent outside during the commute. While the time in traffic jams increases for compact cities, the total commuting time decreases due to shorter distances between home and work place. Concerning adaptation measures, it is shown that increases in the albedo of the urban surfaces lead to an increase in daytime heat stress. Dramatic increases in heat stress exposure are found when both, wall and street albedo, are increased.

Investigating the American Time Use Survey from an Exposure Modeling Perspective

Science.gov (United States)

This paper describes an evaluation of the U.S. Bureau of Labor Statistics' American Time Use Survey (ATUS) for potential use in modeling human exposures to environmental pollutants. The ATUS is a large, on-going, cross-sectional survey of where Americans spend time and what activ...

Estimating time-varying exposure-outcome associations using case-control data: logistic and case-cohort analyses.

Science.gov (United States)

Keogh, Ruth H; Mangtani, Punam; Rodrigues, Laura; Nguipdop Djomo, Patrick

2016-01-05

Traditional analyses of standard case-control studies using logistic regression do not allow estimation of time-varying associations between exposures and the outcome. We present two approaches which allow this. The motivation is a study of vaccine efficacy as a function of time since vaccination. Our first approach is to estimate time-varying exposure-outcome associations by fitting a series of logistic regressions within successive time periods, reusing controls across periods. Our second approach treats the case-control sample as a case-cohort study, with the controls forming the subcohort. In the case-cohort analysis, controls contribute information at all times they are at risk. Extensions allow left truncation, frequency matching and, using the case-cohort analysis, time-varying exposures. Simulations are used to investigate the methods. The simulation results show that both methods give correct estimates of time-varying effects of exposures using standard case-control data. Using the logistic approach there are efficiency gains by reusing controls over time and care should be taken over the definition of controls within time periods. However, using the case-cohort analysis there is no ambiguity over the definition of controls. The performance of the two analyses is very similar when controls are used most efficiently under the logistic approach. Using our methods, case-control studies can be used to estimate time-varying exposure-outcome associations where they may not previously have been considered. The case-cohort analysis has several advantages, including that it allows estimation of time-varying associations as a continuous function of time, while the logistic regression approach is restricted to assuming a step function form for the time-varying association.

Cadmium and mercury exposure over time in Swedish children

Energy Technology Data Exchange (ETDEWEB)

Lundh, T., E-mail: Thomas.Lundh@med.lu.se [Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, SE−22185 Lund (Sweden); Axmon, A., E-mail: Anna.Axmon@med.lu.se [Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, SE−22185 Lund (Sweden); Skerfving, S., E-mail: Staffan.Skerfving@med.lu.se [Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, SE−22185 Lund (Sweden); Broberg, K., E-mail: Karin.Broberg@ki.se [Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, SE−22185 Lund (Sweden); Unit of Metals and Health, Institute of Environmental Medicine, Karolinska Institutet, Nobels väg 13, SE-171 77 Stockholm (Sweden)

2016-10-15

Purpose: Knowledge about changes in exposure to toxic metals over time remains very sparse, in particular for children, the most vulnerable group. Here, we assessed whether a reduction in environmental pollution with cadmium (Cd) and mercury (Hg) caused a change in exposure over time. In total, 1257 children (age 4–9) in two towns in Sweden were sampled once in 1986–2013. Blood concentrations of Cd (b-Cd; n=1120) and Hg (b-Hg; n=560) were determined. Results: The median b-Cd was 0.10 (geometric mean 0.10; range 0.010–0.61) μg/L and b-Hg was 0.91 (geometric mean 0.83; range 0.021–8.2) μg/L. Children living close to a smelter had higher b-Cd and b-Hg than those in urban and rural areas. There was no sex difference in b-Cd or b-Hg, and b-Cd and b-Hg showed no significant accumulation by age. b-Cd decreased only slightly (0.7% per year, p<0.001) over the study period. In contrast, b-Hg did show a clear decrease over the study period (3% per year, p<0.001). Conclusions: The exposure to Cd was very low but still might increase the risk of disease later in life. Moreover, b-Cd only showed a minor decrease, indicating that Cd pollution should be further restricted. b-Hg was relatively low and decreasing, probably because of reduced use of dental amalgam and lower Hg intake from fish. The b-Cd and b-Hg levels decreased much less than the levels of lead in the blood as previously found in the same children. - Highlights: • There are few studies of time trends for exposure to toxic metals, except for lead. • 1986–2013 we studied blood levels of cadmium and mercury in 1257 Swedish children. • The median blood concentration of cadmium was 0.10 μg/L, of mercury 0.83 μg/L. • Cadmium perhaps decreased by 0.7% per year, mercury by 3% per year. • Cadmium accumulation may result in toxic levels in elderly women.

Chronic ethanol exposure produces time- and brain region-dependent changes in gene coexpression networks.

Directory of Open Access Journals (Sweden)

Elizabeth A Osterndorff-Kahanek

Full Text Available Repeated ethanol exposure and withdrawal in mice increases voluntary drinking and represents an animal model of physical dependence. We examined time- and brain region-dependent changes in gene coexpression networks in amygdala (AMY, nucleus accumbens (NAC, prefrontal cortex (PFC, and liver after four weekly cycles of chronic intermittent ethanol (CIE vapor exposure in C57BL/6J mice. Microarrays were used to compare gene expression profiles at 0-, 8-, and 120-hours following the last ethanol exposure. Each brain region exhibited a large number of differentially expressed genes (2,000-3,000 at the 0- and 8-hour time points, but fewer changes were detected at the 120-hour time point (400-600. Within each region, there was little gene overlap across time (~20%. All brain regions were significantly enriched with differentially expressed immune-related genes at the 8-hour time point. Weighted gene correlation network analysis identified modules that were highly enriched with differentially expressed genes at the 0- and 8-hour time points with virtually no enrichment at 120 hours. Modules enriched for both ethanol-responsive and cell-specific genes were identified in each brain region. These results indicate that chronic alcohol exposure causes global 'rewiring' of coexpression systems involving glial and immune signaling as well as neuronal genes.

Techniques for controlling radiation exposure

International Nuclear Information System (INIS)

Ocken, H.; Wood, C.J.

1993-01-01

The US nuclear power industry has been remarkably successful in reducing worker radiation exposure over the past 10 years. There has been more than a fourfold reduction in person-rem per MW-year of electric power generated: from 1.8 person-rems in 1980 to only 0.4 person-rems in 1991. Despite this substantial improvement, challenges for the industry remain. Individual exposure limits have been tightened in the 1990 Recommendations of the International Commission on Radiological Protection, ICRP Publication 60, and there will be more requirements for special maintenance work as plants age, suggesting that vigorous efforts will be required to meet the 1995 industry goals for unit median collective exposure. No one method will suffice, but implementing suitable combinations from this compendium will help utilities to achieve their exposure goals. Radiation reduction is generally cost-effective: Outages are shorter, staffing requirements are reduced, and work quality is improved. Despite up-front costs, the benefits over the following one to three years typically outweigh the expenses

Time characteristics of distortion product otoacoustic emissions recovery function after moderate sound exposure

DEFF Research Database (Denmark)

de Toro, Miguel Angel Aranda; Ordoñez, Rodrigo Pizarro; Hammershøi, Dorte

2006-01-01

Exposure to sound of moderate level temporarily attenuates the amplitude of distortion product otoacoustic emissions (DPOAEs). These changes are similar to the changes observed in absolute hearing thresholds after similar sound exposures. To be able to assess changes over time across a broad...

Cosmic Radiation Exposure of Future Hypersonic Flight Missions.

Science.gov (United States)

Koops, L

2017-06-15

Cosmic radiation exposure in air traffic grows with flight altitude, geographical latitude and flight time. For future high-speed intercontinental point-to-point travel, the trade-off between reduced flight time and enhanced dose rate at higher flight altitudes is investigated. Various representative (partly) hypersonic cruise missions are considered and in dependence on solar activity the integral route dose is calculated for envisaged flight profiles and trajectories. Our results are compared to those for corresponding air connections served by present day subsonic airliners. During solar maximum, we find a significant reduction in route dose for all considered high-speed missions compared to the subsonic reference. However, during solar minimum, comparable or somewhat larger doses result on transpolar trajectories with (partly) hypersonic cruise at Mach 5. Both solar activity and routing are hence found to determine, whether passengers can profit from shorter flight times in terms of radiation exposure, despite of altitude-induced higher dose rates. Yet, aircrews with fixed number of block hours are always subject to larger annual doses, which in the considered cases take values up to five times the reference. We comment on the implications of our results for route planning and aviation decision-making in the absence of radiation shielding solutions. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A simple exposure-time theory for all time-nonlocal transport formulations and beyond.

Science.gov (United States)

Ginn, T. R.; Schreyer, L. G.

2016-12-01

Anomalous transport or better put, anomalous non-transport, of solutes or flowing water or suspended colloids or bacteria etc. has been the subject of intense analyses with multiple formulations appearing in scientific literature from hydrology to geomorphology to chemical engineering, to environmental microbiology to mathematical physics. Primary focus has recently been on time-nonlocal mass conservation formulations such as multirate mass transfer, fractional-time advection-dispersion, continuous-time random walks, and dual porosity modeling approaches, that employ a convolution with a memory function to reflect respective conceptual models of delays in transport. These approaches are effective or "proxy" ones that do not always distinguish transport from immobilzation delays, are generally without connection to measurable physicochemical properties, and involve variously fractional calculus, inverse Laplace or Fourier transformations, and/or complex stochastic notions including assumptions of stationarity or ergodicity at the observation scale. Here we show a much simpler approach to time-nonlocal (non-)transport that is free of all these things, and is based on expressing the memory function in terms of a rate of mobilization of immobilized mass that is a function of the continguous time immobilized. Our approach treats mass transfer completely independently from the transport process, and it allows specification of actual immobilization mechanisms or delays. To our surprize we found that for all practical purposes any memory function can be expressed this way, including all of those associated with the multi-rate mass transfer approaches, original powerlaw, different truncated powerlaws, fractional-derivative, etc. More intriguing is the fact that the exposure-time approach can be used to construct heretofore unseen memory functions, e.g., forms that generate oscillating tails of breakthrough curves such as may occur in sediment transport, forms for delay

Contrast characteristics of barium preparations and the timing of exposure

OpenAIRE

渋谷, 光一; 中桐, 義忠; 東, 義晴; 杉田, 勝彦; 小橋, 高郎; 大倉, 保彦; 丹谷, 延義; 三上, 泰隆; 平木, 祥夫

1995-01-01

We studied the relationship between the contrast characteristics of barium suspension and timing of exposure. We poured several kinds of barium preparations on the phantom manufactured by ourselves, and took X-ray pictures continuously by a DSA system. We analyzed each of the characteris-tics of the contrast. The time which was reguired for the contrast to reach the peak (Contrast Peak Time ; CPT) was unrelated with the kind of barium preparations used. It depended on the viscosity of the con...

Estimating time-varying exposure-outcome associations using case-control data: logistic and case-cohort analyses

Directory of Open Access Journals (Sweden)

Ruth H. Keogh

2016-01-01

Full Text Available Abstract Background Traditional analyses of standard case-control studies using logistic regression do not allow estimation of time-varying associations between exposures and the outcome. We present two approaches which allow this. The motivation is a study of vaccine efficacy as a function of time since vaccination. Methods Our first approach is to estimate time-varying exposure-outcome associations by fitting a series of logistic regressions within successive time periods, reusing controls across periods. Our second approach treats the case-control sample as a case-cohort study, with the controls forming the subcohort. In the case-cohort analysis, controls contribute information at all times they are at risk. Extensions allow left truncation, frequency matching and, using the case-cohort analysis, time-varying exposures. Simulations are used to investigate the methods. Results The simulation results show that both methods give correct estimates of time-varying effects of exposures using standard case-control data. Using the logistic approach there are efficiency gains by reusing controls over time and care should be taken over the definition of controls within time periods. However, using the case-cohort analysis there is no ambiguity over the definition of controls. The performance of the two analyses is very similar when controls are used most efficiently under the logistic approach. Conclusions Using our methods, case-control studies can be used to estimate time-varying exposure-outcome associations where they may not previously have been considered. The case-cohort analysis has several advantages, including that it allows estimation of time-varying associations as a continuous function of time, while the logistic regression approach is restricted to assuming a step function form for the time-varying association.

Time series models of environmental exposures: Good predictions or good understanding.

Science.gov (United States)

Barnett, Adrian G; Stephen, Dimity; Huang, Cunrui; Wolkewitz, Martin

2017-04-01

Time series data are popular in environmental epidemiology as they make use of the natural experiment of how changes in exposure over time might impact on disease. Many published time series papers have used parameter-heavy models that fully explained the second order patterns in disease to give residuals that have no short-term autocorrelation or seasonality. This is often achieved by including predictors of past disease counts (autoregression) or seasonal splines with many degrees of freedom. These approaches give great residuals, but add little to our understanding of cause and effect. We argue that modelling approaches should rely more on good epidemiology and less on statistical tests. This includes thinking about causal pathways, making potential confounders explicit, fitting a limited number of models, and not over-fitting at the cost of under-estimating the true association between exposure and disease. Copyright © 2017 Elsevier Inc. All rights reserved.

Non-linear behaviour of power density and exposure time of argon laser on ocular tissues

Energy Technology Data Exchange (ETDEWEB)

El-Sayed, E M; Talaat, M S; Salem, E F [Physics Department, Faculty of Science, Ain Shams University, Cairo (Egypt)

1997-12-31

In ophthalmology, the thermal effect of argon laser is the most widely used category of laser- tissue interaction. The rise in tissue temperature has to exceed a threshold value for photo coagulation of retinal blood vessels. This value mainly depends on the laser. The most suitable argon laser power P and exposure time (t) which would be more effective for thermal and electrical behaviour of chicken eye was studied. This was achieved by measuring the variations in ocular temperature in electroretinogram (ERG) records under the effect of argon experiment, while power density (P) and exposure time (t) were varied in four different ways for each dose (pt). Results indicated that for the same laser dose, the temperature distribution of the eye, using low power density and high exposure time was higher than that high power density and low exposure time, indicating non-linearity of the laser dose. This finding was confirmed by ERG records which showed similar variations in b-wave latency, amplitude and duration, for the laser exposure conditions. This indicates variations in retinal function due to laser-dependent temperature variations. 5 figs., 3 tabs.

Time and frequency characteristics of temporary threshold shifts caused by pure tone exposures

DEFF Research Database (Denmark)

Ordoñez, Rodrigo Pizarro; Hammershøi, Dorte

2011-01-01

The time-frequency characteristics of Temporary Threshold Shifts (TTS) caused by pure tones were determined using the Békésy audiometric method with narrow-band noise of short duration as the probe stimuli. Two experiments were done using exposures of 3 min at 100 dB above threshold. In the first....... In the second experiment, the TTS recovery curve produced by a 1 kHz pure tone exposure was assessed at 1.5 kHz, at approximately 15 s intervals for the first 5 min and at regularly increasing intervals up to 45 min after the exposure. The results showed a maximum in the recovery around 2 min after the exposure....... The data gathered in these experiments were used to construct a mathematical model of TTS recovery. The model describes both the 1/2-octave shift and the 2 min bounce and it can be used in the comparison of temporary changes in auditory function, assessed at different times and frequencies....

Variations with time and age in the relative risks of solid cancer incidence after radiation exposure

International Nuclear Information System (INIS)

Little, M.P.; Muirhead, C.R.; de Vathaire, F.; Charles, M.W.

1997-01-01

The Japanese atomic bomb survivor cancer incidence dataset and data on five groups exposed to radiation for medical reasons in childhood are analysed and evidence found for a reduction in the radiation-induced relative risk of cancers other than leukaemia with increasing time since exposure and age at exposure. The rate of the reductions in relative risk with time since exposure are not significantly different for those exposed in childhood and for those exposed in adulthood, if adjustment is made for the effects on the relative risk of age at exposure. For those irradiated in childhood, there is a statistically significant annual reduction of 5.8% (95% Cl 2.8, 8.9) in excess relative risk, and there are no strong indications of inter-cohort heterogeniety in the speed of reduction of relative risk. After adjustment for the effects of age at exposure, there is a significant annual reduction of 3.6% (95% Cl 1.6, 5.6) in excess relative risk in all age-at-exposure groups. There are significant reductions of 5.2% (95% Cl 3.7, 6.8) in excess relative risk per year of age at exposure. There are statistically significant (P = 0.04) interactions between the exponential adjustments to the excess relative risk for age at exposure and time since exposure in the Japanese data, but no indications (P = 0.38) of such interactions when powers of time since exposure and attained age are used to adjust the excess relative risk, so that the fit of the model with power adjustments is to be preferred to that of the model with exponential adjustments. (author)

Homework schedule: an important factor associated with shorter sleep duration among Chinese school-aged children.

Science.gov (United States)

Li, Shenghui; Yang, Qian; Chen, Zhe; Jin, Xingming; Jiang, Fan; Shen, Xiaoming

2014-09-03

This study was designed to examine the hypothesis that homework schedule has adverse impacts on Chinese children's sleep-wake habits and sleep duration. A random sample of 19,299 children aged 5.08 to 11.99 years old participated in a large, cross-sectional survey. A parent-administered questionnaire was completed to quantify children's homework schedule and sleep behaviors. Generally, it was demonstrated that more homework schedule was significantly associated with later bedtime, later wake time, and shorter sleep duration. Among all sleep variables, bedtime and sleep duration during weekdays appeared to be most affected by homework schedule, especially homework schedule during weekdays.

Exposure assessment in front of a multi-band base station antenna.

Science.gov (United States)

Kos, Bor; Valič, Blaž; Kotnik, Tadej; Gajšek, Peter

2011-04-01

This study investigates occupational exposure to electromagnetic fields in front of a multi-band base station antenna for mobile communications at 900, 1800, and 2100 MHz. Finite-difference time-domain method was used to first validate the antenna model against measurement results published in the literature and then investigate the specific absorption rate (SAR) in two heterogeneous, anatomically correct human models (Virtual Family male and female) at distances from 10 to 1000 mm. Special attention was given to simultaneous exposure to fields of three different frequencies, their interaction and the additivity of SAR resulting from each frequency. The results show that the highest frequency--2100 MHz--results in the highest spatial-peak SAR averaged over 10 g of tissue, while the whole-body SAR is similar at all three frequencies. At distances > 200 mm from the antenna, the whole-body SAR is a more limiting factor for compliance to exposure guidelines, while at shorter distances the spatial-peak SAR may be more limiting. For the evaluation of combined exposure, a simple summation of spatial-peak SAR maxima at each frequency gives a good estimation for combined exposure, which was also found to depend on the distribution of transmitting power between the different frequency bands. Copyright © 2010 Wiley-Liss, Inc.

A re-examination of the mere exposure effect: The influence of repeated exposure on recognition, familiarity, and liking.

Science.gov (United States)

Montoya, R Matthew; Horton, Robert S; Vevea, Jack L; Citkowicz, Martyna; Lauber, Elissa A

2017-05-01

To evaluate the veracity of models of the mere exposure effect and to understand the processes that moderate the effect, we conducted a meta-analysis of the influence of repeated exposure on liking, familiarity, recognition, among other evaluations. We estimated parameters from 268 curve estimates drawn from 81 articles and revealed that the mere exposure effect was characterized by a positive slope and negative quadratic effect consistent with an inverted-U shaped curve. In fact, such curves were associated with (a) all visual, but not auditory stimuli; (b) exposure durations shorter than 10 s and longer than 1 min; (c) both homogeneous and heterogeneous presentation types; and (d) ratings that were taken after all stimuli were presented. We conclude that existing models for the mere exposure effect do not adequately account for the findings, and we provide a framework to help guide future research. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Minimally invasive mitral valve surgery through right mini-thoracotomy: recommendations for good exposure, stable cardiopulmonary bypass, and secure myocardial protection.

Science.gov (United States)

Ito, Toshiaki

2015-07-01

An apparent advantage of minimally invasive mitral surgery through right mini-thoracotomy is cosmetic appearance. Possible advantages of this procedure are a shorter ventilation time, shorter hospital stay, and less blood transfusion. With regard to hard endpoints, such as operative mortality, freedom from reoperation, or cardiac death, this method is reportedly equivalent, but not superior, to the standard median sternotomy technique. However, perfusion-related complications (e.g., stroke, vascular damage, and limb ischemia) tend to occur more frequently in minimally invasive technique than with the standard technique. In addition, valve repair through a small thoracotomy is technically demanding. Therefore, screening out patients who are not appropriate for performing minimally invasive surgery is the first step. Vascular disease and inadequate anatomy can be evaluated with contrast-enhanced computed tomography. Peripheral cannulation should be carefully performed, using transesophageal echocardiography guidance. Preoperative detailed planning of the valve repair process is desirable because every step is time-consuming in minimally invasive surgery. Three-dimensional echocardiography is a powerful tool for this purpose. For satisfactory exposure and detailed observation of the valve, a special left atrial retractor and high-definition endoscope are useful. Valve repair can be performed in minimally invasive surgery as long as cardiopulmonary bypass is stable and bloodless exposure of the valve is obtained.

Changes in adaptability following perinatal morphine exposure in juvenile and adult rats.

Science.gov (United States)

Klausz, Barbara; Pintér, Ottó; Sobor, Melinda; Gyarmati, Zsuzsa; Fürst, Zsuzsanna; Tímár, Júlia; Zelena, Dóra

2011-03-05

The problem of drug abuse among pregnant women causes a major concern. The aim of the present study was to examine the adaptive consequences of long term maternal morphine exposure in offspring at different postnatal ages, and to see the possibility of compensation, as well. Pregnant rats were treated daily with morphine from the day of mating (on the first two days 5mg/kgs.c. than 10mg/kg) until weaning. Male offspring of dams treated with physiological saline served as control. Behavior in the elevated plus maze (EPM; anxiety) and forced swimming test (FST; depression) as well as adrenocorticotropin and corticosterone hormone levels were measured at postpartum days 23-25 and at adult age. There was only a tendency of spending less time in the open arms of the EPM in morphine treated rats at both ages, thus, the supposed anxiogenic impact of perinatal exposure with morphine needs more focused examination. In response to 5min FST morphine exposed animals spent considerable longer time with floating and shorter time with climbing at both ages which is an expressing sign of depression-like behavior. Perinatal morphine exposure induced a hypoactivity of the stress axis (adrenocorticotropin and corticosterone elevations) to strong stimulus (FST). Our results show that perinatal morphine exposure induces long term depression-like changes. At the same time the reactivity to the stress is failed. These findings on rodents presume that the progenies of morphine users could have lifelong problems in adaptive capability and might be prone to develop psychiatric disorders. Copyright © 2010 Elsevier B.V. All rights reserved.

Effects of time-variable exposure regimes of the insecticide chlorpyrifos on freshwater invertebrate communities in microcosms

NARCIS (Netherlands)

Zafar, M.I.; Wijngaarden, van R.; Roessink, I.; Brink, van den P.J.

2011-01-01

The present study compared the effects of different time-variable exposure regimes having the same time-weighted average (TWA) concentration of the organophosphate insecticide chlorpyrifos on freshwater invertebrate communities to enable extrapolation of effects across exposure regimes. The

The molecular basis of simple relationships between exposure concentration and toxic effects with time.

Science.gov (United States)

Tennekes, Henk A; Sánchez-Bayo, Francisco

2013-07-05

Understanding the toxicity of chemicals to organisms requires considering the molecular mechanisms involved as well as the relationships between exposure concentration and toxic effects with time. Our current knowledge about such relationships is mainly explained from a toxicodynamic and toxicokinetic perspective. This paper re-introduces an old approach that takes into account the biochemical mode of action and their resulting biological effects over time of exposure. Empirical evidence demonstrates that the Druckrey-Küpfmüller toxicity model, which was validated for chemical carcinogens in the early 1960s, is also applicable to a wide range of toxic compounds in ecotoxicology. According to this model, the character of a poison is primarily determined by the reversibility of critical receptor binding. Chemicals showing irreversible or slowly reversible binding to specific receptors will produce cumulative effects with time of exposure, and whenever the effects are also irreversible (e.g. death) they are reinforced over time; these chemicals have time-cumulative toxicity. Compounds having non-specific receptor binding, or involving slowly reversible binding to some receptors that do not contribute to toxicity, may also be time-dependent; however, their effects depend primarily on the exposure concentration, with time playing a minor role. Consequently, the mechanism of toxic action has important implications for risk assessment. Traditional risk approaches cannot predict the impacts of toxicants with time-cumulative toxicity in the environment. New assessment procedures are needed to evaluate the risk that the latter chemicals pose on humans and the environment. An example is shown to explain how the risk of time-dependent toxicants is underestimated when using current risk assessment protocols. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Radiation exposure in transcatheter patent ductus arteriosus closure: time to tune?

Science.gov (United States)

Villemain, Olivier; Malekzadeh-Milani, Sophie; Sitefane, Fidelio; Mostefa-Kara, Meriem; Boudjemline, Younes

2018-05-01

The aims of this study were to describe radiation level at our institution during transcatheter patent ductus arteriosus occlusion and to evaluate the components contributing to radiation exposure. Transcatheter occlusion relying on X-ray imaging has become the treatment of choice for patients with patent ductus arteriosus. Interventionists now work hard to minimise radiation exposure in order to reduce risk of induced cancers. We retrospectively reviewed all consecutive children who underwent transcatheter closure of patent ductus arteriosus from January 2012 to January 2016. Clinical data, anatomical characteristics, and catheterisation procedure parameters were reported. Radiation doses were analysed for the following variables: total air kerma, mGy; dose area product, Gy.cm2; dose area product per body weight, Gy.cm2/kg; and total fluoroscopic time. A total of 324 patients were included (median age=1.51 [Q1-Q3: 0.62-4.23] years; weight=10.3 [6.7-17.0] kg). In all, 322/324 (99.4%) procedures were successful. The median radiation doses were as follows: total air kerma: 26 (14.5-49.3) mGy; dose area product: 1.01 (0.56-2.24) Gy.cm2; dose area product/kg: 0.106 (0.061-0.185) Gy.cm2/kg; and fluoroscopic time: 2.8 (2-4) min. In multivariate analysis, a weight >10 kg, a ductus arteriosus width <2 mm, complications during the procedure, and a high frame rate (15 frames/second) were risk factors for an increased exposure. Lower doses of radiation can be achieved with subsequent recommendations: technical improvement, frame rate reduction, avoidance of biplane cineangiograms, use of stored fluoroscopy as much as possible, and limitation of fluoroscopic time. A greater use of echocardiography might even lessen the exposure.

Mendelian randomization analysis of a time-varying exposure for binary disease outcomes using functional data analysis methods.

Science.gov (United States)

Cao, Ying; Rajan, Suja S; Wei, Peng

2016-12-01

A Mendelian randomization (MR) analysis is performed to analyze the causal effect of an exposure variable on a disease outcome in observational studies, by using genetic variants that affect the disease outcome only through the exposure variable. This method has recently gained popularity among epidemiologists given the success of genetic association studies. Many exposure variables of interest in epidemiological studies are time varying, for example, body mass index (BMI). Although longitudinal data have been collected in many cohort studies, current MR studies only use one measurement of a time-varying exposure variable, which cannot adequately capture the long-term time-varying information. We propose using the functional principal component analysis method to recover the underlying individual trajectory of the time-varying exposure from the sparsely and irregularly observed longitudinal data, and then conduct MR analysis using the recovered curves. We further propose two MR analysis methods. The first assumes a cumulative effect of the time-varying exposure variable on the disease risk, while the second assumes a time-varying genetic effect and employs functional regression models. We focus on statistical testing for a causal effect. Our simulation studies mimicking the real data show that the proposed functional data analysis based methods incorporating longitudinal data have substantial power gains compared to standard MR analysis using only one measurement. We used the Framingham Heart Study data to demonstrate the promising performance of the new methods as well as inconsistent results produced by the standard MR analysis that relies on a single measurement of the exposure at some arbitrary time point. © 2016 WILEY PERIODICALS, INC.

Observing expertise-related actions leads to perfect time flow estimations.

Directory of Open Access Journals (Sweden)

Yin-Hua Chen

Full Text Available The estimation of the time of exposure of a picture portraying an action increases as a function of the amount of movement implied in the action represented. This effect suggests that the perceiver creates an internal embodiment of the action observed as if internally simulating the entire movement sequence. Little is known however about the timing accuracy of these internal action simulations, specifically whether they are affected by the level of familiarity and experience that the observer has of the action. In this study we asked professional pianists to reproduce different durations of exposure (shorter or longer than one second of visual displays both specific (a hand in piano-playing action and non-specific to their domain of expertise (a hand in finger-thumb opposition and scrambled-pixels and compared their performance with non-pianists. Pianists outperformed non-pianists independently of the time of exposure of the stimuli; remarkably the group difference was particularly magnified by the pianists' enhanced accuracy and stability only when observing the hand in the act of playing the piano. These results for the first time provide evidence that through musical training, pianists create a selective and self-determined dynamic internal representation of an observed movement that allows them to estimate precisely its temporal duration.

Long term exposure to respirable volcanic ash on Montserrat: a time series simulation

Science.gov (United States)

Hincks, T. K.; Aspinall, W. P.; Baxter, P. J.; Searl, A.; Sparks, R. S. J.; Woo, G.

2006-01-01

Frequent ash fallout from long-lived eruptions (with active phases greater than 5 years) may lead to local populations experiencing unacceptably high cumulative exposures to respirable particulate matter. Ash from Montserrat has been shown to contain significant levels of cristobalite and other reactive agents that are associated with an increased risk of developing pneumoconiosis (including silicosis) and other long-term health problems. There are a number of difficulties associated with estimating risks in populations due to uncertain and wide ranging individual exposures, change in behaviour with time and the natural variation in individual response. Present estimates of risk in workers and other population groups are simplifications based on a limited number of exposure measurements taken on Montserrat (1996-1999), and exposure-response curves from epidemiological studies of coal workers exposed to siliceous dust. In this paper we present a method for calculating the long-term cumulative exposure to cristobalite from volcanic ash by Monte Carlo simulation. Code has been written to generate synthetic time series for volcanic activity, rainfall, ash deposition and erosion to give daily ash deposit values and cristobalite fraction at a range of locations. The daily mean personal exposure for PM10 and cristobalite is obtained by sampling from a probability distribution, with distribution parameters dependent on occupation, ground deposit depth and daily weather conditions. Output from multiple runs is processed to calculate the exceedance probability for cumulative exposure over a range of occupation types, locations and exposure periods. Results are interpreted in terms of current occupational standards, and epidemiological exposure-response functions for silicosis are applied to quantify the long-term health risk. Assuming continuing volcanic activity, median risk of silicosis (profusion 1/0 or higher) for an average adult after 20 years continuous exposure is

Estimating the acute health effects of coarse particulate matter accounting for exposure measurement error.

Science.gov (United States)

Chang, Howard H; Peng, Roger D; Dominici, Francesca

2011-10-01

In air pollution epidemiology, there is a growing interest in estimating the health effects of coarse particulate matter (PM) with aerodynamic diameter between 2.5 and 10 μm. Coarse PM concentrations can exhibit considerable spatial heterogeneity because the particles travel shorter distances and do not remain suspended in the atmosphere for an extended period of time. In this paper, we develop a modeling approach for estimating the short-term effects of air pollution in time series analysis when the ambient concentrations vary spatially within the study region. Specifically, our approach quantifies the error in the exposure variable by characterizing, on any given day, the disagreement in ambient concentrations measured across monitoring stations. This is accomplished by viewing monitor-level measurements as error-prone repeated measurements of the unobserved population average exposure. Inference is carried out in a Bayesian framework to fully account for uncertainty in the estimation of model parameters. Finally, by using different exposure indicators, we investigate the sensitivity of the association between coarse PM and daily hospital admissions based on a recent national multisite time series analysis. Among Medicare enrollees from 59 US counties between the period 1999 and 2005, we find a consistent positive association between coarse PM and same-day admission for cardiovascular diseases.

Induction of hypospadias in a murine model by maternal exposure to synthetic estrogens

International Nuclear Information System (INIS)

Suk Kim, Kun; Torres, Carlos R.; Yucel, Selcuk; Raimondo, Kamakshi; Cunha, G.R.Gerald R.; Baskin, L.S.

2004-01-01

We tested the hypothesis that maternal exposure to synthetic estrogen can cause hypospadias in male offspring and defined the morphological changes in the disrupted urethral seam. Timed pregnant C57/6 mice were exposed to synthetic estrogens. The genital tubercles were examined for the presence of hypospadias using histology, three-dimensional computer reconstruction, and plastic cast injection molds of the urethra. Microscopic serial analysis confirmed the presence of hypospadias, which occurred in ∼50% of the synthetic-estrogen-treated male fetuses. No effect was seen in the female embryos. Plastic cast injection showed that affected males had a shorter total urethral length and loss of male anatomic features such as the prostatic utricle. Exposure to synthetic estrogens during pregnancy affects the normal development of the urethra in the mouse. We conclude that endocrine disrupters play an important role in genital tubercle anomalies

Analysis of real-time mixture cytotoxicity data following repeated exposure using BK/TD models

International Nuclear Information System (INIS)

Teng, S.; Tebby, C.; Barcellini-Couget, S.; De Sousa, G.; Brochot, C.; Rahmani, R.; Pery, A.R.R.

2016-01-01

Cosmetic products generally consist of multiple ingredients. Thus, cosmetic risk assessment has to deal with mixture toxicity on a long-term scale which means it has to be assessed in the context of repeated exposure. Given that animal testing has been banned for cosmetics risk assessment, in vitro assays allowing long-term repeated exposure and adapted for in vitro – in vivo extrapolation need to be developed. However, most in vitro tests only assess short-term effects and consider static endpoints which hinder extrapolation to realistic human exposure scenarios where concentration in target organs is varies over time. Thanks to impedance metrics, real-time cell viability monitoring for repeated exposure has become possible. We recently constructed biokinetic/toxicodynamic models (BK/TD) to analyze such data (Teng et al., 2015) for three hepatotoxic cosmetic ingredients: coumarin, isoeugenol and benzophenone-2. In the present study, we aim to apply these models to analyze the dynamics of mixture impedance data using the concepts of concentration addition and independent action. Metabolic interactions between the mixture components were investigated, characterized and implemented in the models, as they impacted the actual cellular exposure. Indeed, cellular metabolism following mixture exposure induced a quick disappearance of the compounds from the exposure system. We showed that isoeugenol substantially decreased the metabolism of benzophenone-2, reducing the disappearance of this compound and enhancing its in vitro toxicity. Apart from this metabolic interaction, no mixtures showed any interaction, and all binary mixtures were successfully modeled by at least one model based on exposure to the individual compounds. - Highlights: • We could predict cell response over repeated exposure to mixtures of cosmetics. • Compounds acted independently on the cells. • Metabolic interactions impacted exposure concentrations to the compounds.

Analysis of real-time mixture cytotoxicity data following repeated exposure using BK/TD models

Energy Technology Data Exchange (ETDEWEB)

Teng, S.; Tebby, C. [Models for Toxicology and Ecotoxicology Unit, INERIS, Parc Technologique Alata, BP 2, 60550 Verneuil-en-Halatte (France); Barcellini-Couget, S. [ODESIA Neosciences, Sophia Antipolis, 400 route des chappes, 06903 Sophia Antipolis (France); De Sousa, G. [INRA, ToxAlim, 400 route des Chappes, BP, 167 06903 Sophia Antipolis, Cedex (France); Brochot, C. [Models for Toxicology and Ecotoxicology Unit, INERIS, Parc Technologique Alata, BP 2, 60550 Verneuil-en-Halatte (France); Rahmani, R. [INRA, ToxAlim, 400 route des Chappes, BP, 167 06903 Sophia Antipolis, Cedex (France); Pery, A.R.R., E-mail: alexandre.pery@agroparistech.fr [AgroParisTech, UMR 1402 INRA-AgroParisTech Ecosys, 78850 Thiverval Grignon (France); INRA, UMR 1402 INRA-AgroParisTech Ecosys, 78850 Thiverval Grignon (France)

2016-08-15

Cosmetic products generally consist of multiple ingredients. Thus, cosmetic risk assessment has to deal with mixture toxicity on a long-term scale which means it has to be assessed in the context of repeated exposure. Given that animal testing has been banned for cosmetics risk assessment, in vitro assays allowing long-term repeated exposure and adapted for in vitro – in vivo extrapolation need to be developed. However, most in vitro tests only assess short-term effects and consider static endpoints which hinder extrapolation to realistic human exposure scenarios where concentration in target organs is varies over time. Thanks to impedance metrics, real-time cell viability monitoring for repeated exposure has become possible. We recently constructed biokinetic/toxicodynamic models (BK/TD) to analyze such data (Teng et al., 2015) for three hepatotoxic cosmetic ingredients: coumarin, isoeugenol and benzophenone-2. In the present study, we aim to apply these models to analyze the dynamics of mixture impedance data using the concepts of concentration addition and independent action. Metabolic interactions between the mixture components were investigated, characterized and implemented in the models, as they impacted the actual cellular exposure. Indeed, cellular metabolism following mixture exposure induced a quick disappearance of the compounds from the exposure system. We showed that isoeugenol substantially decreased the metabolism of benzophenone-2, reducing the disappearance of this compound and enhancing its in vitro toxicity. Apart from this metabolic interaction, no mixtures showed any interaction, and all binary mixtures were successfully modeled by at least one model based on exposure to the individual compounds. - Highlights: • We could predict cell response over repeated exposure to mixtures of cosmetics. • Compounds acted independently on the cells. • Metabolic interactions impacted exposure concentrations to the compounds.

Comparison of bioassays with different exposure time patterns: the added value of dynamic modelling in predictive ecotoxicology.

Science.gov (United States)

Billoir, Elise; Delhaye, Hèlène; Forfait, Carole; Clément, Bernard; Triffault-Bouchet, Gaëlle; Charles, Sandrine; Delignette-Muller, Marie Laure

2012-01-01

The purpose of this study was to compare Daphnia magna responses to cadmium between two toxicity experiments performed in static and flow-through conditions. As a consequence of how water was renewed, the two experiments were characterised by two different exposure time patterns for daphnids, time-varying and constant, respectively. Basing on survival, growth and reproduction, we addressed the questions of organism development and sensitivity to cadmium. Classical analysis methods are not designed to deal with the time dimension and therefore not suitable to compare effects of different exposure time patterns. We used instead a dynamic modelling framework taking all timepoints and the time course of exposure into account, making comparable the results obtained from our two experiments. This modelling framework enabled us to detect an improvement of organism development in flow-through conditions compared to static ones and infer similar sensitivity to cadmium for both exposure time patterns. Copyright © 2011 Elsevier Inc. All rights reserved.

Family History of Early Infant Death Correlates with Earlier Age at Diagnosis But Not Shorter Time to Diagnosis for Severe Combined Immunodeficiency

Directory of Open Access Journals (Sweden)

Anderson Dik Wai Luk

2017-07-01

Full Text Available BackgroundSevere combined immunodeficiency (SCID is fatal unless treated with hematopoietic stem cell transplant. Delay in diagnosis is common without newborn screening. Family history of infant death due to infection or known SCID (FH has been associated with earlier diagnosis.ObjectiveThe aim of this study was to identify the clinical features that affect age at diagnosis (AD and time to the diagnosis of SCID.MethodsFrom 2005 to 2016, 147 SCID patients were referred to the Asian Primary Immunodeficiency Network. Patients with genetic diagnosis, age at presentation (AP, and AD were selected for study.ResultsA total of 88 different SCID gene mutations were identified in 94 patients, including 49 IL2RG mutations, 12 RAG1 mutations, 8 RAG2 mutations, 7 JAK3 mutations, 4 DCLRE1C mutations, 4 IL7R mutations, 2 RFXANK mutations, and 2 ADA mutations. A total of 29 mutations were previously unreported. Eighty-three of the 94 patients fulfilled the selection criteria. Their median AD was 4 months, and the time to diagnosis was 2 months. The commonest SCID was X-linked (n = 57. A total of 29 patients had a positive FH. Candidiasis (n = 27 and bacillus Calmette–Guérin (BCG vaccine infection (n = 19 were the commonest infections. The median age for candidiasis and BCG infection documented were 3 months and 4 months, respectively. The median absolute lymphocyte count (ALC was 1.05 × 109/L with over 88% patients below 3 × 109/L. Positive FH was associated with earlier AP by 1 month (p = 0.002 and diagnosis by 2 months (p = 0.008, but not shorter time to diagnosis (p = 0.494. Candidiasis was associated with later AD by 2 months (p = 0.008 and longer time to diagnosis by 0.55 months (p = 0.003. BCG infections were not associated with age or time to diagnosis.ConclusionFH was useful to aid earlier diagnosis but was overlooked by clinicians and not by parents. Similarly, typical clinical features of

Analysis of real-time mixture cytotoxicity data following repeated exposure using BK/TD models.

Science.gov (United States)

Teng, S; Tebby, C; Barcellini-Couget, S; De Sousa, G; Brochot, C; Rahmani, R; Pery, A R R

2016-08-15

Cosmetic products generally consist of multiple ingredients. Thus, cosmetic risk assessment has to deal with mixture toxicity on a long-term scale which means it has to be assessed in the context of repeated exposure. Given that animal testing has been banned for cosmetics risk assessment, in vitro assays allowing long-term repeated exposure and adapted for in vitro - in vivo extrapolation need to be developed. However, most in vitro tests only assess short-term effects and consider static endpoints which hinder extrapolation to realistic human exposure scenarios where concentration in target organs is varies over time. Thanks to impedance metrics, real-time cell viability monitoring for repeated exposure has become possible. We recently constructed biokinetic/toxicodynamic models (BK/TD) to analyze such data (Teng et al., 2015) for three hepatotoxic cosmetic ingredients: coumarin, isoeugenol and benzophenone-2. In the present study, we aim to apply these models to analyze the dynamics of mixture impedance data using the concepts of concentration addition and independent action. Metabolic interactions between the mixture components were investigated, characterized and implemented in the models, as they impacted the actual cellular exposure. Indeed, cellular metabolism following mixture exposure induced a quick disappearance of the compounds from the exposure system. We showed that isoeugenol substantially decreased the metabolism of benzophenone-2, reducing the disappearance of this compound and enhancing its in vitro toxicity. Apart from this metabolic interaction, no mixtures showed any interaction, and all binary mixtures were successfully modeled by at least one model based on exposure to the individual compounds. Copyright © 2016 Elsevier Inc. All rights reserved.

Implications of shorter cells in PEP

International Nuclear Information System (INIS)

Wiedemann, H.

1975-01-01

Further studies on the beam-stay-clear requirements in PEP led to the conclusion that the vertical aperture needed to be enlarged. There are two main reasons for that: Observations at SPEAR indicate that the aperture should be large enough for a fully coupled beam. Full coupling of the horizontal and vertical betatron oscillations occurs not only occasionally when the energy, tune or betatron function at the interaction point is changed but also due to the beam/endash/beam effect of two strong colliding beams. The second reason for an increased aperture requirement is the nonlinear perturbation of the particle trajectories by the sextupoles. This perturbation increases a fully coupled beam by another 50% to 80%. Both effects together with a +-5 mm allowance for closed orbit perturbation result in a vertical beam-stay-clear in the bending magnets of +-4.8 to +-5.6 cm, compared to the present +-2.0 cm. This beam-stay-clear, together with additional space for vacuum chamber, etc., leads to very costly bending magnets. In this note, a shorter cell length is proposed which would reduce considerably the vertical beam-stay-clear requirements in the bending magnets. 7 figs

Copper patinas formed in different atmospheres and exposure times

International Nuclear Information System (INIS)

Lobo, V.M.M.; Almeida, M.E.; Balmayor, M.; Tomas, H.M.L.R.

1998-01-01

Atmospheric corrosion products in copper samples, known as patinas, formed in industrial-marine, severe-marine and rural atmospheres exposed for 1,2,3, and 4 years, have been studied. The nature and structure of the products formed, characterized by X-ray diffraction (XRD) and infrared spectrometry (FTIR) depend on the time of exposure and the type of atmosphere. Copper patinas have been extensively mentioned in the literature, but the structural nature of their compounds, which vary according to the time of exposure and types of atmospheres, is still not adequately described in the literature. In order to give a contribution to this area, copper panels were exposed for 1,2,3, and 4 years in different types of atmospheres representing situations commonly observed, and subsequently the patinas were studied by XRD and FTIR 150 mm x 1 mm copper panels from commercial copper were exposed to three different atmospheric conditions in Portugal: industrial-marine (Leixoes, near Oporto, highly industrialized city close to the Ocean, subject to SO 2 from refineries); rural (Pego, small village in rural environment). The panels, attached to the appropriate stands, in accordance with ISO 8565 (1), were exposed for periods of 1,2,3 and 4 years, adequately collected for laboratory analysis by infrared spectrometry (FTIR). (Author)

Time allocation shifts and pollutant exposure due to traffic congestion: an analysis using the national human activity pattern survey.

Science.gov (United States)

Zhang, Kai; Batterman, Stuart A

2009-10-15

Traffic congestion increases air pollutant exposures of commuters and urban populations due to the increased time spent in traffic and the increased vehicular emissions that occur in congestion, especially "stop-and-go" traffic. Increased time in traffic also decreases time in other microenvironments, a trade-off that has not been considered in previous time activity pattern (TAP) analyses conducted for exposure assessment purposes. This research investigates changes in time allocations and exposures that result from traffic congestion. Time shifts were derived using data from the National Human Activity Pattern Survey (NHAPS), which was aggregated to nine microenvironments (six indoor locations, two outdoor locations and one transport location). After imputing missing values, handling outliers, and conducting other quality checks, these data were stratified by respondent age, employment status and period (weekday/weekend). Trade-offs or time-shift coefficients between time spent in vehicles and the eight other microenvironments were then estimated using robust regression. For children and retirees, congestion primarily reduced the time spent at home; for older children and working adults, congestion shifted the time spent at home as well as time in schools, public buildings, and other indoor environments. Changes in benzene and PM(2.5) exposure were estimated for the current average travel delay in the U.S. (9 min day(-1)) and other scenarios using the estimated time shifts coefficients, concentrations in key microenvironments derived from the literature, and a probabilistic analysis. Changes in exposures depended on the duration of the congestion and the pollutant. For example, a 30 min day(-1) travel delay was determined to account for 21+/-12% of current exposure to benzene and 14+/-8% of PM(2.5) exposure. The time allocation shifts and the dynamic approach to TAPs improve estimates of exposure impacts from congestion and other recurring events.

Occupational exposures are associated with worse morbidity in patients with chronic obstructive pulmonary disease.

Science.gov (United States)

Paulin, Laura M; Diette, Gregory B; Blanc, Paul D; Putcha, Nirupama; Eisner, Mark D; Kanner, Richard E; Belli, Andrew J; Christenson, Stephanie; Tashkin, Donald P; Han, MeiLan; Barr, R Graham; Hansel, Nadia N

2015-03-01

Links between occupational exposures and morbidity in individuals with established chronic obstructive pulmonary disease (COPD) remain unclear. To determine the impact of occupational exposures on COPD morbidity. A job exposure matrix (JEM) determined occupational exposure likelihood based on longest job in current/former smokers (n = 1,075) recruited as part of the Subpopulations and Intermediate Outcomes in COPD Study, of whom 721 had established COPD. Bivariate and multivariate linear regression models estimated the association of occupational exposure with COPD, and among those with established disease, the occupational exposure associations with 6-minute-walk distance (6MWD), the Modified Medical Research Council Dyspnea Scale (mMRC), the COPD Assessment Test (CAT), St. George's Respiratory Questionnaire (SGRQ), 12-item Short-Form Physical Component (SF-12), and COPD exacerbations requiring health care utilization, adjusting for demographics, current smoking status, and cumulative pack-years. An intermediate/high risk of occupational exposure by JEM was found in 38% of participants. In multivariate analysis, those with job exposures had higher odds of COPD (odds ratio, 1.44; 95% confidence interval, 1.04-1.97). Among those with COPD, job exposures were associated with shorter 6MWDs (-26.0 m; P = 0.006); worse scores for mMRC (0.23; P = 0.004), CAT (1.8; P = 0.003), SGRQ (4.5; P = 0.003), and SF-12 Physical (-3.3; P Accounting for smoking, occupational exposure was associated with COPD risk and, for those with established disease, shorter walk distance, greater breathlessness, worse quality of life, and increased exacerbation risk. Clinicians should obtain occupational histories from patients with COPD because work-related exposures may influence disease burden.

Prenatal exposure to antifungal medication may change anogenital distance in male offspring

DEFF Research Database (Denmark)

Madelung Mogensen, Djamilla; Bergkvist Pihl, Maria; Skakkebæk, Niels E.

2017-01-01

BACKGROUND: Vaginal candidiasis is frequent among pregnant women and it is treated with anti-fungal medication (conazoles). Conazoles have anti-androgenic properties and prenatal exposure in rodents is associated with a shorter (less masculine) anogenital distance (AGD) in male offspring. To our...

High precision instrumentation for measuring the true exposure time in diagnostic X-ray examinations

International Nuclear Information System (INIS)

Silva, Danubia B.; Santos, Marcus A.P.; Barros, Fabio R.; Santos, Luiz A.P.

2013-01-01

One of the most important physical quantities to be evaluated in diagnostic radiology is the radiation exposure time experimented by the patient during the X-ray examination. IAEA and WHO organizations have suggested that any country must create a quality surveillance program to verify if each type of ionizing radiation equipment used in the hospitals and medical clinics are in conformity with the accepted uncertainties following the international standards. The purpose of this work is to present a new high precision methodology for measuring true exposure time in diagnostic X-ray examinations: pulsed, continuous or digital one. An electronic system named CronoX, which will be soon registered at the Brazilian Patent Office (INPI), is the equipment that provides such a high precision measurement. The principle of measurement is based on the electrical signal captured by a sensor that enters in a regeneration amplifier to transform it in a digital signal, which is treated by a microprocessor (uP). The signal treatment results in a two measured times: 1) T rx , the true X-ray exposure time; 2) T nx , the time in which the X-ray machine is repeatedly cut off during the pulsed irradiation and there is no delivery dose to the patient. Conventional Polymat X-ray equipment and dental X-ray machines were used to generate X-ray photons and take the measurements with the electronic systems. The results show that such a high precision instrumentation displays the true exposure time in diagnostic X-ray examinations and indicates a new method to be purposed for the quality surveillance programs in radiology. (author)

Serum phthalate levels and time to pregnancy in couples from Greenland, Poland and Ukraine.

Directory of Open Access Journals (Sweden)

Ina Olmer Specht

Full Text Available Phthalates are ubiquitous industrial chemicals that have been associated with altered reproductive function in rodents. Several human studies have reported an inverse association between male testosterone and phthalate levels. Our aim was to investigate time to pregnancy (TTP according to serum levels of diethylhexyl phthalate (DEHP and diisononyl phthalate (DiNP metabolites in both partners. In 2002-2004 we enrolled 938 pregnant women and 401 male spouses from Greenland, Poland and Ukraine. Six oxidized metabolites of DEHP and DiNP were summarized for each of the two parent compounds to provide proxies of the internal exposure. We used Cox discrete-time models to estimate fecundability ratios (FR and 95% confidence intervals (95% CIs for men and women according to their proxy-DEHP or -DiNP serum levels adjusted for a fixed set of covariates. The FR was slightly elevated among women with high levels of DEHP (FR=1.14, 95% CI 1.00;1.30 suggesting a shorter TTP in these women. The FR was unrelated to DiNP in women, whereas the results for men were inconsistent pointing in opposite directions. First-time pregnant women from Greenland with high serum DiNP levels had a longer TTP. This study spanning large contrast in environmental exposure does not indicate adverse effects of phthalates on couple fecundity. The shorter TTP in women with high levels of DEHP metabolites is unexplained and needs further investigation.

Lack of the correlation between biochemical effects on rats and blood carboxyhemoglobin concentrations in various conditions of single acute exposure to carbon monoxide

Energy Technology Data Exchange (ETDEWEB)

Sokal, J.A.

1975-01-01

The relationship between conditions of exposure to carbon monoxide (CO) and biochemical effects was investigated in experiments on rats. The magnitude and the time of biochemical disturbances in the tissues resulting from two different exposures consisting of 1 vol. percent CO for 4 min and 0.4 vol. percent CO for 40 min respectively were compared. In both cases, at the end of exposure the same level of blood carboxyhemoglobin (COHb) (about 50 percent) was reached. The biochemical determinations in the blood (pH, glucose, lactate, pyruvate) and brain tissue (lactate, pyruvate) were carried out immediately after termination of the exposure and after the time periods of restitution. CO exposure resulted in a decreased blood pH, increased level of blood glucose, as well as that of lactate and pyruvate both in blood and brain tissue. These changes were much more pronounced following the longer-lesser exposure than after the shorter-intense one, although blood concentrations of COHb was the same. The observed phenomenon puts some light on the frequently encountered lack of the correlation between COHb level in blood and severity of CO intoxication in clinical practice.

Web-Based Survey Application to Collect Contextually Relevant Geographic Data With Exposure Times: Application Development and Feasibility Testing

Science.gov (United States)

Tobin, Karin; Rudolph, Jonathan; Latkin, Carl

2018-01-01

Background Although studies that characterize the risk environment by linking contextual factors with individual-level data have advanced infectious disease and substance use research, there are opportunities to refine how we define relevant neighborhood exposures; this can in turn reduce the potential for exposure misclassification. For example, for those who do not inject at home, injection risk behaviors may be more influenced by the environment where they inject than where they live. Similarly, among those who spend more time away from home, a measure that accounts for different neighborhood exposures by weighting each unique location proportional to the percentage of time spent there may be more correlated with health behaviors than one’s residential environment. Objective This study aimed to develop a Web-based application that interacts with Google Maps application program interfaces (APIs) to collect contextually relevant locations and the amount of time spent in each. Our analysis examined the extent of overlap across different location types and compared different approaches for classifying neighborhood exposure. Methods Between May 2014 and March 2017, 547 participants enrolled in a Baltimore HIV care and prevention study completed an interviewer-administered Web-based survey that collected information about where participants were recruited, worked, lived, socialized, injected drugs, and spent most of their time. For each location, participants gave an address or intersection which they confirmed using Google Map and Street views. Geographic coordinates (and hours spent in each location) were joined to neighborhood indicators by Community Statistical Area (CSA). We computed a weighted exposure based on the proportion of time spent in each unique location. We compared neighborhood exposures based on each of the different location types with one another and the weighted exposure using analysis of variance with Bonferroni corrections to account for

One long chain among shorter chains : the Flory approach revisited

OpenAIRE

Raphaël , E.; Fredrickson , G.; Pincus , P.

1992-01-01

We consider the mean square end-to-end distance of a long chain immersed in a monodisperse, concentrated solution of shorter, chemically identical chains. In contrast with the earlier work of Flory, no simplifying assumption on the wave vector dependence of the effective potential between segments is made. In order to obtain a closed form expression for the dimension of the long chain, we first derive a general expression for the mean square end-to-end distance of a flexible chain with arbitr...

Shorter telomeres in peripheral blood mononuclear cells from older persons with sarcopenia: results from an exploratory study

Directory of Open Access Journals (Sweden)

Emanuele eMarzetti

2014-08-01

Full Text Available Background. Telomere shortening in peripheral blood mononuclear cells (PBMCs has been associated with biological age and several chronic degenerative diseases. However, the relationship between telomere length and sarcopenia, a hallmark of the aging process, is unknown. The aim of the present study was therefore to determine whether PBMC telomeres obtained from sarcopenic older persons were shorter relative to non-sarcopenic peers. We further explored if PBMC telomere length was associated with frailty, a major clinical correlate of sarcopenia.Methods. Analyses were conducted in 142 persons aged >/= 65 years referred to a geriatric outpatient clinic (University Hospital. The presence of sarcopenia was established according to the European Working Group on Sarcopenia in Older People criteria, with bioelectrical impedance analysis used for muscle mass estimation. The frailty status was determined by both the Fried’s criteria (physical frailty, PF and a modified Rockwood’s frailty index (FI. Telomere length was measured in PBMCs by quantitative real-time polymerase chain reaction according to the Telomere/Single copy gene ratio (T/S method.Results. Among 142 outpatients (mean age 75.0 ± 6.5 years, 59.2% women, sarcopenia was diagnosed in 23 individuals (19.3%. The PF phenotype was detected in 74 participants (52.1%. The average FI score was 0.46 ± 0.17. PBMC telomeres were shorter in sarcopenic subjects (T/S = 0.21; 95% CI: 0.18 – 0.24 relative to non-sarcopenic individuals (T/S = 0.26; 95%: CI: 0.24 – 0.28; p = 0.01, independent of age, gender, smoking habit, or comorbidity. No significant associations were determined between telomere length and either PF or FI.Conclusion. PBMC telomere length, expressed as T/S values, is shorter in older outpatients with sarcopenia. The cross-sectional assessment of PBMC telomere length is not sufficient at capturing the complex, multidimensional syndrome of frailty.

1H NMR-based metabolomics of time-dependent responses of Eisenia fetida to sub-lethal phenanthrene exposure

International Nuclear Information System (INIS)

Lankadurai, Brian P.; Wolfe, David M.; Simpson, Andre J.; Simpson, Myrna J.

2011-01-01

1 H NMR-based metabolomics was used to examine the response of the earthworm Eisenia fetida after exposure to sub-lethal concentrations of phenanthrene over time. Earthworms were exposed to 0.025 mg/cm 2 of phenanthrene (1/64th of the LC 50 ) via contact tests over four days. Earthworm tissues were extracted using a mixture of chloroform, methanol and water, resulting in polar and non-polar fractions that were analyzed by 1 H NMR after one, two, three and four days. NMR-based metabolomic analyses revealed heightened E. fetida responses with longer phenanthrene exposure times. Amino acids alanine and glutamate, the sugar maltose, the lipids cholesterol and phosphatidylcholine emerged as potential indicators of phenanthrene exposure. The conversion of succinate to fumarate in the Krebs cycle was also interrupted by phenanthrene. Therefore, this study shows that NMR-based metabolomics is a powerful tool for elucidating time-dependent relationships in addition to the mode of toxicity of phenanthrene in earthworm exposure studies. - Highlights: → NMR-based earthworm metabolomic analysis of the mode of action of phenanthrene is presented. → The earthworm species E. fetida were exposed to sub-lethal phenanthrene concentrations. → Both polar and non-polar metabolites of E. fetida tissue extracts were analyzed by 1 H NMR. → Longer phenanthrene exposure times resulted in heightened earthworm responses. → An interruption of the Krebs cycle was also observed due to phenanthrene exposure. - 1 H NMR metabolomics is used to determine the relationship between phenanthrene exposure and the metabolic response of the earthworm E. fetida over time and also to elucidate the phenanthrene mode of toxicity.

Unintentional exposure to ultraviolet radiation

International Nuclear Information System (INIS)

Sliney, D.H.

1987-01-01

To evaluate the risks from unintentional exposure to ultraviolet radiation (UVR), and to consider hazard control regulation, one must face first the problem of their state of scientific knowledge and the public's perception of UVR. Few people in the general public would question the health benefits of sunlight. Many flock to the beaches each summer to develop a healthy tan. Since the 1920's scientists have recognized that most of the benefits--and risks--of sunlight exposure result from the UVR present in sunlight. Dermatologists warn sunbathers to avoid exposure or protect themselves against the intense midday UVR or risk skin cancer. A growing number of scientists warn of hazards to the eye if UVR--perhaps even shorter visible wavelengths--are not filtered by lenses. In addition to any intentional exposure for health or cosmetic purposes, many people are also exposed to UVR without being aware of it or without their intent to be exposed. Outdoor workers are exposed to sunlight, many industrial workers (e.g., welders) are exposed to UVR from arc sources, some UVR penetrates clothing, and people indoors are exposed to UVR from artificial lighting

Elevated background TV exposure over time increases behavioural scores of 18-month-old toddlers.

Science.gov (United States)

Chonchaiya, Weerasak; Sirachairat, Chalermpol; Vijakkhana, Nakul; Wilaisakditipakorn, Tanaporn; Pruksananonda, Chandhita

2015-10-01

To investigate whether trends of TV exposure from age six to 18 months and adult TV programmes were associated with behavioural concerns of 18-month-old Thai toddlers. There were 194 healthy infants recruited at age six months and followed up until 18 months of age in this present cohort. TV exposure variables were assessed by interviewing in depth at both six- and 18-month-old visits. A mother of each participant rated the child's behaviours using the Child Behaviour Checklist. Infants who were increasingly exposed to TV from age six to 18 months with adult programmes since six months of age had higher pervasive developmental problems and oppositional defiant behaviours scores. Exposure to adult TV programmes at age six months was also associated with emotionally reactive problems, aggression and externalising behaviours in the final regression models. To promote appropriate toddlers' behaviours at age 18 months, elevated background TV exposure over time should be discouraged. Furthermore, paediatricians should emphasise such effects of TV exposure on child behaviours with parents at health supervision visits. As such, parents will be aware of the detrimental effect of increased background TV exposure over time on their children's behaviours. ©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Evaluating methods for estimating space-time paths of individuals in calculating long-term personal exposure to air pollution

Science.gov (United States)

Schmitz, Oliver; Soenario, Ivan; Vaartjes, Ilonca; Strak, Maciek; Hoek, Gerard; Brunekreef, Bert; Dijst, Martin; Karssenberg, Derek

2016-04-01

Air pollution is one of the major concerns for human health. Associations between air pollution and health are often calculated using long-term (i.e. years to decades) information on personal exposure for each individual in a cohort. Personal exposure is the air pollution aggregated along the space-time path visited by an individual. As air pollution may vary considerably in space and time, for instance due to motorised traffic, the estimation of the spatio-temporal location of a persons' space-time path is important to identify the personal exposure. However, long term exposure is mostly calculated using the air pollution concentration at the x, y location of someone's home which does not consider that individuals are mobile (commuting, recreation, relocation). This assumption is often made as it is a major challenge to estimate space-time paths for all individuals in large cohorts, mostly because limited information on mobility of individuals is available. We address this issue by evaluating multiple approaches for the calculation of space-time paths, thereby estimating the personal exposure along these space-time paths with hyper resolution air pollution maps at national scale. This allows us to evaluate the effect of the space-time path and resulting personal exposure. Air pollution (e.g. NO2, PM10) was mapped for the entire Netherlands at a resolution of 5×5 m2 using the land use regression models developed in the European Study of Cohorts for Air Pollution Effects (ESCAPE, http://escapeproject.eu/) and the open source software PCRaster (http://www.pcraster.eu). The models use predictor variables like population density, land use, and traffic related data sets, and are able to model spatial variation and within-city variability of annual average concentration values. We approximated space-time paths for all individuals in a cohort using various aggregations, including those representing space-time paths as the outline of a persons' home or associated parcel

Design and application of a web-based real-time personal PM2.5 exposure monitoring system.

Science.gov (United States)

Sun, Qinghua; Zhuang, Jia; Du, Yanjun; Xu, Dandan; Li, Tiantian

2018-06-15

Growing demand from public health research for conduct large-scale epidemiological studies to explore health effect of PM 2.5 was well-documented. To address this need, we design a web-based real-time personal PM 2.5 exposure monitoring system (RPPM2.5 system) which can help researcher to get big data of personal PM 2.5 exposure with low-cost, low labor requirement, and low operating technical requirements. RPPM2.5 system can provide relative accurate real-time personal exposure data for individuals, researches, and decision maker. And this system has been used in a survey of PM 2.5 personal exposure level conducted in 5 cities of China and has provided mass of valuable data for epidemiological research. Copyright © 2018 Elsevier B.V. All rights reserved.

The design of a miniature personal exposure monitor for continuous real-time data acquisition in electromagnetic field exposure assessment

International Nuclear Information System (INIS)

Hansen, N.H.; Conroy, T.J.; Wilson, B.W.

1994-06-01

The design of a small, light-weight personal exposure monitor suitable for use in EMF exposure assessment studies is nearing completion at Pacific Northwest Laboratory. The monitor is designed to be non-obtrusive, battery operated, and able to continuously record extremely low-frequency (ELF) (1Ohz--500hz) magnetic-field data. It also captures high-frequency (500hz--1OMhz) transients that exceed a preset threshold, retaining the largest transients in memory. The monitor can record one or more days of data on a single easily replaceable, credit-card-size memory (PCMCIA). A battery charge will last a minimum of one day. Batteries are rechargeable and easily replaced. A data-compression algorithm is under development that will be tailored to the efficient compression of low-frequency EMF signals and will permit data to be logged for at least one day before swapping memory cards. The memory cards are readable by a base- station computer that can perform analysis of the data. The monitor is designed to accommodate four inputs supporting full-field sensors as well as a proposed ocular exposure measurement system. Our design effort has shown that a practical personal exposure monitor for EMF can be built based on current technology, continuous logging of real-time ELF waveforms is both feasible and practical, and such a device is appropriate for proposed EMF exposure studies

Fight and air exposure times of caught and released salmonids from the South Fork Snake River

Science.gov (United States)

Roth, Curtis J.; Schill, Daniel J.; Quist, Michael C.

2018-01-01

Catch-and-release regulations are among the most common types of fishing regulations. In recent years, concerns have arisen regarding the exposure of fish to air during catch-and-release angling. The purpose of our study was to quantify the length of time angled fish were exposed to air by anglers in a typical catch-and-release fishery and relate it to the lengths of time reported to produce negative effects. In total, 312 individual anglers were observed on the South Fork Snake River, Idaho, from May through August 2016. Fight time varied from 1.1 s to 230.0 s, and average fight time was 40.0 s (SD = 36.8). Total air exposure times varied from 0.0 s to 91.8 s and averaged 19.3 s (SD = 15.0). Though not statistically significant, a trend in reduced fight times was observed when anglers were guided and increased air exposure times when a net was used and a picture was taken. Results of the current study suggest that anglers expose fish to air for periods that are much less than those reported to cause mortality.

Cobalt exposure and lung disease in tungsten carbide production. A cross-sectional study of current workers

International Nuclear Information System (INIS)

Sprince, N.L.; Oliver, L.C.; Eisen, E.A.; Greene, R.E.; Chamberlin, R.I.

1988-01-01

A cross-sectional study of 1,039 tungsten carbide (TC) production workers was carried out. The purposes were (1) to evaluate the prevalence of interstitial lung disease (ILD) and work-related wheezing, (2) to assess correlations between cobalt exposure and pulmonary disease, (3) to compare lung disease in grinders of hard carbide versus nongrinders, and (4) to evaluate the effects of new and previous threshold limit values for cobalt of 50 and 100 micrograms/m3. We obtained medical and occupational histories, flow-volume loops, single breath carbon monoxide diffusing capacity (DLCO), and chest radiographs. Time-weighted average cobalt levels were determined at every step in the production process. Work-related wheeze occurred in 113 participants (10.9%). Profusion greater than or equal to 1/0 occurred in 26 (2.6%) and interstitial lung disease (defined as profusion greater than or equal to 1M, FVC or DLCO less than or equal to 70%, and FEV1/FVC% greater than or equal to 75) in 7 (0.7%). The relative odds of work-related wheeze was 2.1 times for present cobalt exposures exceeding 50 micrograms/m3 compared with exposures less than or equal to 50 micrograms/m3. The relative odds of profusion greater than or equal to 1/0 was 5.1 times for average lifetime cobalt exposures exceeding 100 micrograms/m3 compared with exposures less than or equal to 100 micrograms/m3 in those with latency exceeding 10 yr. ILD was found in three workers with very low average lifetime exposures (less than 8 micrograms/m3) and shorter latencies. Grinders of hard carbide had lower mean DLCO than nongrinders, even though their cobalt exposures were lower

Prospects for quantitative and time-resolved double and continuous exposure off-axis electron holography

Energy Technology Data Exchange (ETDEWEB)

Migunov, Vadim, E-mail: v.migunov@fz-juelich.de [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Dwyer, Christian [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Department of Physics, Arizona State University, Tempe, AZ 85287 (United States); Boothroyd, Chris B. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Pozzi, Giulio [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Department of Physics and Astronomy, University of Bologna, viale B. Pichat 6/2, Bologna 40127 (Italy); Dunin-Borkowski, Rafal E. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany)

2017-07-15

The technique of double exposure electron holography, which is based on the superposition of two off-axis electron holograms, was originally introduced before the availability of digital image processing to allow differences between electron-optical phases encoded in two electron holograms to be visualised directly without the need for holographic reconstruction. Here, we review the original method and show how it can now be extended to permit quantitative studies of phase shifts that oscillate in time. We begin with a description of the theory of off-axis electron hologram formation for a time-dependent electron wave that results from the excitation of a specimen using an external stimulus with a square, sinusoidal, triangular or other temporal dependence. We refer to the more general method as continuous exposure electron holography, present preliminary experimental measurements and discuss how the technique can be used to image electrostatic potentials and magnetic fields during high frequency switching experiments. - Highlights: • Double and continuous exposure electron holography are described in detail. • The ability to perform quantitative studies of phase shifts that are oscillating in time is illustrated. • Theoretical considerations related to noise are presented. • Future high frequency electromagnetic switching experiments are proposed.

Effect of dose rate and exposure time on the stimulation effect of tube growth of Pinus sylvestris pollen

International Nuclear Information System (INIS)

Zelles, L.; Fendrik, I.; Technische Univ. Hannover

1975-01-01

The stimulating effect of ionizing radiation in respect to dose rate and exposure time was studied using the tube growth of Pinus silvestris pollen. Stimulation was registered with a small dose (50 rad) supplied at low dose rates (0.5; 1.0; 3.0 and 5.0 rad/sec) and with higher doses (300; 800 and 1,400 rad) supplied at higher dose rates (10; 40 and 50 rad/sec). This suggests that only the exposure time is of importance for radiation-induced stimulation provided that the exposure time does not exceed 100 sec. (orig.) [de

{sup 1}H NMR-based metabolomics of time-dependent responses of Eisenia fetida to sub-lethal phenanthrene exposure

Energy Technology Data Exchange (ETDEWEB)

Lankadurai, Brian P.; Wolfe, David M.; Simpson, Andre J. [Department of Chemistry, University of Toronto, 1265 Military Trail, Toronto, Ontario M1C 1A4 Canada (Canada); Simpson, Myrna J., E-mail: myrna.simpson@utoronto.ca [Department of Chemistry, University of Toronto, 1265 Military Trail, Toronto, Ontario M1C 1A4 Canada (Canada)

2011-10-15

{sup 1}H NMR-based metabolomics was used to examine the response of the earthworm Eisenia fetida after exposure to sub-lethal concentrations of phenanthrene over time. Earthworms were exposed to 0.025 mg/cm{sup 2} of phenanthrene (1/64th of the LC{sub 50}) via contact tests over four days. Earthworm tissues were extracted using a mixture of chloroform, methanol and water, resulting in polar and non-polar fractions that were analyzed by {sup 1}H NMR after one, two, three and four days. NMR-based metabolomic analyses revealed heightened E. fetida responses with longer phenanthrene exposure times. Amino acids alanine and glutamate, the sugar maltose, the lipids cholesterol and phosphatidylcholine emerged as potential indicators of phenanthrene exposure. The conversion of succinate to fumarate in the Krebs cycle was also interrupted by phenanthrene. Therefore, this study shows that NMR-based metabolomics is a powerful tool for elucidating time-dependent relationships in addition to the mode of toxicity of phenanthrene in earthworm exposure studies. - Highlights: > NMR-based earthworm metabolomic analysis of the mode of action of phenanthrene is presented. > The earthworm species E. fetida were exposed to sub-lethal phenanthrene concentrations. > Both polar and non-polar metabolites of E. fetida tissue extracts were analyzed by {sup 1}H NMR. > Longer phenanthrene exposure times resulted in heightened earthworm responses. > An interruption of the Krebs cycle was also observed due to phenanthrene exposure. - {sup 1}H NMR metabolomics is used to determine the relationship between phenanthrene exposure and the metabolic response of the earthworm E. fetida over time and also to elucidate the phenanthrene mode of toxicity.

In-situ real time measurements of net erosion rates of copper during hydrogen plasma exposure

Science.gov (United States)

Kesler, Leigh; Wright, Graham; Peterson, Ethan; Whyte, Dennis

2013-10-01

In order to properly understand the dynamics of net erosion/deposition in fusion reactors, such as tokamaks, a diagnostic measuring the real time rates of net erosion/deposition during plasma exposure is necessary. The DIONISOS experiment produces real time measurements of net erosion/deposition by using Rutherford backscattering spectroscopy (RBS) ion beam analysis simultaneously with plasma exposure from a helicon plasma source. This in-situ method improves on ex-situ weight loss measurements by allowing measurement of possible synergistic effects of high ion implantation rates and net erosion rate and by giving a real time response to changes in plasma parameters. Previous work has validated this new technique for measuring copper (Cu) erosion from helium (He) plasma ion bombardment. This technique is now extended to measure copper erosion due to deuterium and hydrogen plasma ion exposure. Targets used were a 1.5 μm Cu layer on an aluminum substrate. Cu layer thickness is tracked in real time using 1.2 MeV proton RBS. Measured erosion rates will be compared to results from literature and He erosion rates. Supported by US DoE award DE-SC00-02060.

Real-Time Aircraft Cosmic Ray Radiation Exposure Predictions from the NAIRAS Model

Science.gov (United States)

Mertens, C. J.; Tobiska, W.; Kress, B. T.; Xu, X.

2012-12-01

The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) is a prototype operational model for predicting commercial aircraft radiation exposure from galactic and solar cosmic rays. NAIRAS predictions are currently streaming live from the project's public website, and the exposure rate nowcast is also available on the SpaceWx smartphone app for iPhone, IPad, and Android. Cosmic rays are the primary source of human exposure to high linear energy transfer radiation at aircraft altitudes, which increases the risk of cancer and other adverse health effects. Thus, the NAIRAS model addresses an important national need with broad societal, public health and economic benefits. There is also interest in extending NAIRAS to the LEO environment to address radiation hazard issues for the emerging commercial spaceflight industry. The processes responsible for the variability in the solar wind, interplanetary magnetic field, solar energetic particle spectrum, and the dynamical response of the magnetosphere to these space environment inputs, strongly influence the composition and energy distribution of the atmospheric ionizing radiation field. Real-time observations are required at a variety of locations within the geospace environment. The NAIRAS model is driven by real-time input data from ground-, atmospheric-, and space-based platforms. During the development of the NAIRAS model, new science questions and observational data gaps were identified that must be addressed in order to obtain a more reliable and robust operational model of atmospheric radiation exposure. The focus of this talk is to present the current capabilities of the NAIRAS model, discuss future developments in aviation radiation modeling and instrumentation, and propose strategies and methodologies of bridging known gaps in current modeling and observational capabilities.

Quantification of acute vocal fold epithelial surface damage with increasing time and magnitude doses of vibration exposure.

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Tsuyoshi Kojima

Full Text Available Because the vocal folds undergo repeated trauma during continuous cycles of vibration, the epithelium is routinely susceptible to damage during phonation. Excessive and prolonged vibration exposure is considered a significant predisposing factor in the development of vocal fold pathology. The purpose of the present study was to quantify the extent of epithelial surface damage following increased time and magnitude doses of vibration exposure using an in vivo rabbit phonation model. Forty-five New Zealand white breeder rabbits were randomized to nine groups and received varying phonation time-doses (30, 60, or 120 minutes and magnitude-doses (control, modal intensity phonation, or raised intensity phonation of vibration exposure. Scanning electron microscopy and transmission electron microscopy was used to quantify the degree of epithelial surface damage. Results revealed a significant reduction in microprojection density, microprojection height, and depth of the epithelial surface with increasing time and phonation magnitudes doses, signifying increased epithelial surface damage risk with excessive and prolonged vibration exposure. Destruction to the epithelial cell surface may provide significant insight into the disruption of cell function following prolonged vibration exposure. One important goal achieved in the present study was the quantification of epithelial surface damage using objective imaging criteria. These data provide an important foundation for future studies of long-term tissue recovery from excessive and prolonged vibration exposure.

Televised Antismoking Advertising: Effects of Level and Duration of Exposure

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Cotter, Trish; Perez, Donna; Wakefield, Melanie

2013-01-01

Objectives. We assessed the effects of levels and duration of exposure to televised antismoking advertising on cognitive and behavioral changes. Methods. We used data from a serial cross-sectional telephone survey with weekly interviews of adult smokers and recent quitters in New South Wales, Australia (n = 13 301), between April 2005 and December 2010. We merged survey data with commercial TV ratings data to estimate individuals’ exposure to antismoking advertising. Results. Logistic regression analyses indicated that after adjustment for a wide range of potential confounders, exposure to antismoking advertising at levels between 100 and 200 gross rating points per week on average over 6 to 9 weeks was associated with an increased likelihood of having (1) salient quitting thoughts and (2) recent quit attempts. Associations between exposure for shorter periods and these outcomes were not significant. Conclusions. Broadcasting schedules may affect the success of antismoking ads. Campaign planners should ensure advertising exposure at adequate frequency over relatively sustained periods to maximize impact. PMID:23763419

Televised antismoking advertising: effects of level and duration of exposure.

Science.gov (United States)

Dunlop, Sally; Cotter, Trish; Perez, Donna; Wakefield, Melanie

2013-08-01

We assessed the effects of levels and duration of exposure to televised antismoking advertising on cognitive and behavioral changes. We used data from a serial cross-sectional telephone survey with weekly interviews of adult smokers and recent quitters in New South Wales, Australia (n = 13,301), between April 2005 and December 2010. We merged survey data with commercial TV ratings data to estimate individuals' exposure to antismoking advertising. Logistic regression analyses indicated that after adjustment for a wide range of potential confounders, exposure to antismoking advertising at levels between 100 and 200 gross rating points per week on average over 6 to 9 weeks was associated with an increased likelihood of having (1) salient quitting thoughts and (2) recent quit attempts. Associations between exposure for shorter periods and these outcomes were not significant. Broadcasting schedules may affect the success of antismoking ads. Campaign planners should ensure advertising exposure at adequate frequency over relatively sustained periods to maximize impact.

Temporal variation of optimal UV exposure time over Korea: risks and benefits of surface UV radiation

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Lee, Y. G.; Koo, J. H.

2015-12-01

Solar UV radiation in a wavelength range between 280 to 400 nm has both positive and negative influences on human body. Surface UV radiation is the main natural source of vitamin D, providing the promotion of bone and musculoskeletal health and reducing the risk of a number of cancers and other medical conditions. However, overexposure to surface UV radiation is significantly related with the majority of skin cancer, in addition other negative health effects such as sunburn, skin aging, and some forms of eye cataracts. Therefore, it is important to estimate the optimal UV exposure time, representing a balance between reducing negative health effects and maximizing sufficient vitamin D production. Previous studies calculated erythemal UV and vitamin-D UV from the measured and modelled spectral irradiances, respectively, by weighting CIE Erythema and Vitamin D3 generation functions (Kazantzidis et al., 2009; Fioletov et al., 2010). In particular, McKenzie et al. (2009) suggested the algorithm to estimate vitamin-D production UV from erythemal UV (or UV index) and determined the optimum conditions of UV exposure based on skin type Ⅱ according to the Fitzpatrick (1988). Recently, there are various demands for risks and benefits of surface UV radiation on public health over Korea, thus it is necessary to estimate optimal UV exposure time suitable to skin type of East Asians. This study examined the relationship between erythemally weighted UV (UVEry) and vitamin D weighted UV (UVVitD) over Korea during 2004-2012. The temporal variations of the ratio (UVVitD/UVEry) were also analyzed and the ratio as a function of UV index was applied in estimating the optimal UV exposure time. In summer with high surface UV radiation, short exposure time leaded to sufficient vitamin D and erythema and vice versa in winter. Thus, the balancing time in winter was enough to maximize UV benefits and minimize UV risks.

Residential exposure to traffic noise and leisure-time sports - A population-based study.

Science.gov (United States)

Roswall, Nina; Ammitzbøll, Gunn; Christensen, Jeppe Schultz; Raaschou-Nielsen, Ole; Jensen, Steen Solvang; Tjønneland, Anne; Sørensen, Mette

2017-08-01

Traffic levels have been found a significant environmental predictor for physical inactivity. A recent study suggested that traffic noise annoyance was associated with lower physical activity. We investigated associations between modelled residential traffic noise and leisure-time sports. In the Diet, Cancer and Health cohort, we performed cross-sectional analyses using data from the baseline questionnaire (1993-97), and longitudinal analyses of change between baseline and follow-up (2000-02). People reported participation (yes/no) and hours of leisure-time sport, from which we calculated MET hrs/week. Present and historical addresses from 1987 to 2002 were found in national registries, and traffic noise was modelled 1 and 5 years before enrolment, and from baseline to follow-up. Analyses were performed using logistic and linear regression. Traffic noise exposure 5 years before baseline was associated with higher prevalence odds ratio of non-participation in leisure-time sports; significantly for road traffic noise (odds ratio (OR): 1.10; 95% confidence interval (CI): 1.07-1.13) and borderline for railway noise (OR: 1.03; 95% CI: 0.99-1.07), per 10dB. In longitudinal analyses, a 10dB higher road traffic noise was associated with a higher prevalence odds ratio of ceasing (OR: 1.12; 95% CI: 1.07-1.18) and a lower prevalence odds ratio of initiating (OR: 0.92; 95% CI: 0.87-0.96) leisure-time sports. Exposure to railway noise was negatively associated with baseline MET hrs/week, whereas no association was found in longitudinal analyses, or for road traffic noise. The study suggests that long-term exposure to residential road traffic noise is negatively associated with leisure-time sports. Results for railway noise were less consistent. Copyright © 2017 Elsevier GmbH. All rights reserved.

Health effects of subchronic exposure to environmental levels of diesel exhaust.

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Reed, M D; Gigliotti, A P; McDonald, J D; Seagrave, J C; Seilkop, S K; Mauderly, J L

2004-04-01

Diesel exhaust is a public health concern and contributor to both ambient and occupational air pollution. As part of a general health assessment of multiple anthropogenic source emissions conducted by the National Environmental Respiratory Center (NERC), a series of health assays was conducted on rats and mice exposed to environmentally relevant levels of diesel exhaust. This article summarizes the study design and exposures, and reports findings on several general indicators of toxicity and carcinogenic potential. Diesel exhaust was generated from a commonly used 2000 model 5.9-L, 6-cylinder turbo diesel engine operated on a variable-load heavy-duty test cycle burning national average certification fuel. Animals were exposed to clean air (control) or four dilutions of whole emissions based on particulate matter concentration (30, 100, 300, and 1000 microg/m(3)). Male and female F344 rats and A/J mice were exposed by whole-body inhalation 6 h/day, 7 days/wk, for either 1 wk or 6 mo. Exposures were characterized in detail. Effects of exposure on clinical observations, body and organ weights, serum chemistry, hematology, histopathology, bronchoalveolar lavage, and serum clotting factors were mild. Significant exposure-related effects occurring in both male and female rats included decreases in serum cholesterol and clotting Factor VII and slight increases in serum gamma-glutamyl transferase. Several other responses met screening criteria for significant exposure effects but were not consistent between genders or exposure times and were not corroborated by related parameters. Carcinogenic potential as determined by micronucleated reticulocyte counts and proliferation of adenomas in A/J mice were unaffected by 6 mo of exposure. Parallel studies demonstrated effects on cardiac function and resistance to viral infection; however, the results reported here show few and only modest health hazards from subchronic or shorter exposures to realistic concentrations of

Real-time measurement of outdoor worker's exposure to solar ultraviolet radiation in Pretoria, South Africa

Directory of Open Access Journals (Sweden)

Mmathapelo Makgabutlane

2015-05-01

Full Text Available The city of Pretoria in South Africa receives considerable solar ultraviolet radiation (UVR because of its low latitude (22–35°S and relatively clear skies. Certain meteorological factors affect the amount of solar UVR that reaches the ground; the most dominant factors being stratospheric ozone, cloud cover and solar zenith angle. It is known that overexposure to solar UVR may lead to the development of adverse health conditions, the most significant being skin cancer. Outdoor workers spend a significant amount of time outside and are thus susceptible to this risk. In this case study, we estimated, for the first time, the real-time solar UVR exposure of an outdoor worker in Pretoria. Measurements were made on 27 and 28 May 2013 using a handheld ultraviolet index (UVI meter calibrated against a science-grade biometer at the South African Weather Service in Pretoria. Personal exposure estimation was used to discern the pattern in diurnal and annual sunburn risk for the outdoor worker. Ambient UVR levels ranged from 0 UVI to 4.66 UVI and the outdoor worker’s potential exposure estimates regularly exceeded 80% of these levels depending on the time of day. The risk of sunburn was evident; however, actual incidents would depend on individual skin photosensitivity and melanin content, as well as sun protection used. Further research is needed to determine the personal exposure estimations of outdoor workers in other provinces in which solar UVR levels may be equally high, or higher than those in Pretoria.

Performance and exposure indices of rats exposed to low concentrations of lead.

Science.gov (United States)

Cory-Slechta, D A; Weiss, B; Cox, C

1985-04-01

To further characterize the lower end of the function relating lead exposure and biological exposure indices to behavior, male weanling rats were exposed chronically to drinking solutions containing 25 ppm sodium acetate (controls) or 25 ppm lead acetate. Behavioral training began when the animals reached 50 days of age, and performance on a fixed-interval 1-min schedule of food reinforcement was then assessed over 90 experimental sessions (136 days). This exposure produced overall response rate increases over the first 40 sessions that were similar to those observed previously with higher concentrations of lead. Response rates of the two groups tended to merge subsequently. The increased overall response rates in the treated group derived primarily from an increased frequency of shorter interresponse times (IRTs) and increased running rates (calculated without the postreinforcement interval). Blood lead (PbB) and zinc protoporphyrin (ZPP) values were determined following sessions 30, 60, and 90. PbB values of the lead-exposed group averaged 15 to 20 micrograms/dl throughout the study; ZPP did not differ. The mean brain lead value of the treated group was 0.07 micrograms Pb/g. Blood-brain ratios (1.38 to 4.06) were substantially greater than those previously observed at higher exposures. These data extend to even lower exposures, and lower blood lead concentrations, the effective concentration for behavioral effects, and further emphasize the importance of the sensitivity of the endpoint in assessing behavioral toxicity.

Timing and Duration of Traffic-related Air Pollution Exposure and the Risk for Childhood Wheeze and Asthma.

Science.gov (United States)

Brunst, Kelly J; Ryan, Patrick H; Brokamp, Cole; Bernstein, David; Reponen, Tiina; Lockey, James; Khurana Hershey, Gurjit K; Levin, Linda; Grinshpun, Sergey A; LeMasters, Grace

2015-08-15

The timing and duration of traffic-related air pollution (TRAP) exposure may be important for childhood wheezing and asthma development. We examined the relationship between TRAP exposure and longitudinal wheezing phenotypes and asthma at age 7 years. Children completed clinical examinations annually from age 1 year through age 4 years and age 7 years. Parental-reported wheezing was assessed at each age, and longitudinal wheezing phenotypes (early-transient, late-onset, persistent) and asthma were defined at age 7 years. Participants' time-weighted exposure to TRAP, from birth through age 7 years, was estimated using a land-use regression model. The relationship between TRAP exposure and wheezing phenotypes and asthma was examined. High TRAP exposure at birth was significantly associated with both transient and persistent wheezing phenotypes (adjusted odds ratio [aOR] = 1.64; 95% confidence interval [CI], 1.04-2.57 and aOR = 2.31; 95% CI, 1.28-4.15, respectively); exposure from birth to age 1 year and age 1 to 2 years was also associated with persistent wheeze. Only children with high average TRAP exposure from birth through age 7 years were at significantly increased risk for asthma (aOR = 1.71; 95% CI, 1.01-2.88). Early-life exposure to TRAP is associated with increased risk for persistent wheezing, but only long-term exposure to high levels of TRAP throughout childhood was associated with asthma development.

The impact of baking time and bread storage temperature on bread crumb properties.

Science.gov (United States)

Bosmans, Geertrui M; Lagrain, Bert; Fierens, Ellen; Delcour, Jan A

2013-12-15

Two baking times (9 and 24 min) and storage temperatures (4 and 25 °C) were used to explore the impact of heat exposure during bread baking and subsequent storage on amylopectin retrogradation, water mobility, and bread crumb firming. Shorter baking resulted in less retrogradation, a less extended starch network and smaller changes in crumb firmness and elasticity. A lower storage temperature resulted in faster retrogradation, a more rigid starch network with more water inclusion and larger changes in crumb firmness and elasticity. Crumb to crust moisture migration was lower for breads baked shorter and stored at lower temperature, resulting in better plasticized biopolymer networks in crumb. Network stiffening, therefore, contributed less to crumb firmness. A negative relation was found between proton mobilities of water and biopolymers in the crumb gel network and crumb firmness. The slope of this linear function was indicative for the strength of the starch network. Copyright © 2013 Elsevier Ltd. All rights reserved.

Accumulative effects of indoor air pollution exposure on leukocyte telomere length among non-smokers

International Nuclear Information System (INIS)

Lin, Nan; Mu, Xinlin; Wang, Guilian; Ren, Yu'ang; Su, Shu; Li, Zhiwen; Wang, Bin; Tao, Shu

2017-01-01

Indoor air pollution is an important environmental factor that contributes to the burden of various diseases. Long-term exposure to ambient air pollution is associated with telomere shortening. However, the association between chronic indoor air pollution from household fuel combustion and leukocyte telomere length has not been studied. In our study, 137 cancer-free non-smokers were recruited. Their exposure levels to indoor air pollution from 1985 to 2014 were assessed using a face-to-face interview questionnaire, and leukocyte telomere length (LTL) was measured using a monochrome multiplex quantitative PCR method. Accumulative exposure to solid fuel usage for cooking was negatively correlated with LTL. The LTL of residents who were exposed to solid fuel combustion for three decades (LTL = 0.70 ± 0.17) was significantly shorter than that of other populations. In addition, education and occupation were related to both exposure to solid fuel and LTL. Sociodemographic factors may play a mediating role in the correlation between leukocyte telomere length and environmental exposure to indoor air pollution. In conclusion, long-term exposure to indoor air pollution may cause LTL dysfunction. - Highlights: • This is the first study to investigate a clear association between indoor air pollution and leukocyte telomere length. • Chronic exposure to household solid fuel combustion and leukocyte telomere length presented a negative correlation. • Shortest leukocyte telomere length belonged to population cooking for longest time. • Education and occupation were remarkably associated with leukocyte telomere length via relating with indoor air pollution. - Long-term exposure to household solid fuel combustion is negatively associated with LTL.

[Secondhand smoke exposure at home and leisure time according to the day of the week (working and non-working day) in Barcelona].

Science.gov (United States)

Martínez-Sánchez, José M; Fu, Marcela; Schiaffino, Anna; Sureda, Xisca; Saltó, Esteve; Moncada, Albert; Ariza, Carles; Nebot, Manel; Pascual, José A; Fernández, Esteve

2012-01-01

The objective of this study is to describe the differences in the exposure to secondhand smoke (SHS) at home and at leisure time according to the day of the week (working and non-working day) which exposure occurs in Barcelona. We carried out a cross-sectional study of a representative sample of adult (>16 years) non-smokers in Barcelona before the Spanish smoking law came into effect (years 2004-2005). We studied the prevalence of exposure to SHS at home and leisure time by means of a questionnaire and a biomarker (salivary cotinine). The questionnaire included questions on exposure to SHS on working days and nonworking days. The prevalence of exposure to SHS at home was 27.4% (6.8% exposed only on working days, 5.7% exposed only on non-working days, and 14.9% exposed on both working and non-working days). The prevalence of exposure to SHS at leisure time was 61.3% (10.7% exposed only on working days, 13.6% exposed only on non-working days, and 37.0% exposed on both working and non-working days). The exposure to SHS only on non-working days at leisure time decreases with age (χ(2) of trend = 183.7; phome on working and non-working days showed higher levels of salivary cotinine concentration, regardless of sex, age group, and educational level. In conclusion, the exposure to SHS occurs mainly during leisure time. Questions on SHS exposure according to working and non-working days allow to characterizing the exposure to SHS, especially when the exposure occurs at leisure time.

Acute exposure to vibration is an apoptosis-inducing stimulus in the vocal fold epithelium.

Science.gov (United States)

Novaleski, Carolyn K; Kimball, Emily E; Mizuta, Masanobu; Rousseau, Bernard

2016-10-01

Clinical voice disorders pose significant communication-related challenges to patients. The purpose of this study was to quantify the rate of apoptosis and tumor necrosis factor-alpha (TNF-α) signaling in vocal fold epithelial cells in response to increasing time-doses and cycle-doses of vibration. 20 New Zealand white breeder rabbits were randomized to three groups of time-doses of vibration exposure (30, 60, 120min) or a control group (120min of vocal fold adduction and abduction). Estimated cycle-doses of vocal fold vibration were extrapolated based on mean fundamental frequency. Laryngeal tissue specimens were evaluated for apoptosis and gene transcript and protein levels of TNF-α. Results revealed that terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was significantly higher after 120min of vibration compared to the control. Transmission electron microscopy (TEM) revealed no significant effect of time-dose on the mean area of epithelial cell nuclei. Extrapolated cycle-doses of vibration exposure were closely related to experimental time-dose conditions, although no significant correlations were observed with TUNEL staining or mean area of epithelial cell nuclei. TUNEL staining was positively correlated with TNF-α protein expression. Our findings suggest that apoptosis can be induced in the vocal fold epithelium after 120min of modal intensity phonation. In contrast, shorter durations of vibration exposure do not result in apoptosis signaling. However, morphological features of apoptosis are not observed using TEM. Future studies are necessary to examine the contribution of abnormal apoptosis to vocal fold diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

Change of exposure response over time and long-term risk of silicosis among a cohort of Chinese pottery workers.

Science.gov (United States)

Sun, Yi; Bochmann, Frank; Morfeld, Peter; Ulm, Kurt; Liu, Yuewei; Wang, Heijiao; Yang, Lei; Chen, Weihong

2011-07-01

An analysis was conducted on a cohort of Chinese pottery workers to estimate the exposure-response relationship between respirable crystalline silica dust exposure and the incidence of radiographically diagnosed silicosis, and to estimate the long-term risk of developing silicosis until the age of 65. The cohort comprised 3,250 employees with a median follow-up duration of around 37 years. Incident cases of silicosis were identified via silicosis registries (Chinese X-ray stage I, similar to International Labor Organisation classification scheme profusion category 1/1). Individual exposure to respirable crystalline silica dust was estimated based on over 100,000 historical dust measurements. The association between dust exposure, incidence and long-time risk of silicosis was quantified by Poisson regression analysis adjusted for age and smoking. The risk of silicosis depended not only on the cumulative respirable crystalline silica dust exposures, but also on the time-dependent respirable crystalline silica dust exposure pattern (long-term average concentration, highest annual concentration ever experienced and time since first exposure). A long-term "excess" risk of silicosis of approximately 1.5/1,000 was estimated among workers with all annual respirable crystalline silica dust concentration estimates less than 0.1 mg/m(3), using the German measurement strategy. This study indicates the importance of proper consideration of exposure information in risk quantification in epidemiological studies.

Change of Exposure Response over Time and Long-Term Risk of Silicosis among a Cohort of Chinese Pottery Workers

Directory of Open Access Journals (Sweden)

Yuewei Liu

2011-07-01

Full Text Available An analysis was conducted on a cohort of Chinese pottery workers to estimate the exposure-response relationship between respirable crystalline silica dust exposure and the incidence of radiographically diagnosed silicosis, and to estimate the long-term risk of developing silicosis until the age of 65. The cohort comprised 3,250 employees with a median follow-up duration of around 37 years. Incident cases of silicosis were identified via silicosis registries (Chinese X-ray stage I, similar to International Labor Organisation classification scheme profusion category 1/1. Individual exposure to respirable crystalline silica dust was estimated based on over 100,000 historical dust measurements. The association between dust exposure, incidence and long-time risk of silicosis was quantified by Poisson regression analysis adjusted for age and smoking. The risk of silicosis depended not only on the cumulative respirable crystalline silica dust exposures, but also on the time-dependent respirable crystalline silica dust exposure pattern (long-term average concentration, highest annual concentration ever experienced and time since first exposure. A long-term “excess” risk of silicosis of approximately 1.5/1,000 was estimated among workers with all annual respirable crystalline silica dust concentration estimates less than 0.1 mg/m3, using the German measurement strategy. This study indicates the importance of proper consideration of exposure information in risk quantification in epidemiological studies.

A shorter and more specific oral sensitization-based experimental model of food allergy in mice.

Science.gov (United States)

Bailón, Elvira; Cueto-Sola, Margarita; Utrilla, Pilar; Rodríguez-Ruiz, Judith; Garrido-Mesa, Natividad; Zarzuelo, Antonio; Xaus, Jordi; Gálvez, Julio; Comalada, Mònica

2012-07-31

Cow's milk protein allergy (CMPA) is one of the most prevalent human food-borne allergies, particularly in children. Experimental animal models have become critical tools with which to perform research on new therapeutic approaches and on the molecular mechanisms involved. However, oral food allergen sensitization in mice requires several weeks and is usually associated with unspecific immune responses. To overcome these inconveniences, we have developed a new food allergy model that takes only two weeks while retaining the main characters of allergic response to food antigens. The new model is characterized by oral sensitization of weaned Balb/c mice with 5 doses of purified cow's milk protein (CMP) plus cholera toxin (CT) for only two weeks and posterior challenge with an intraperitoneal administration of the allergen at the end of the sensitization period. In parallel, we studied a conventional protocol that lasts for seven weeks, and also the non-specific effects exerted by CT in both protocols. The shorter protocol achieves a similar clinical score as the original food allergy model without macroscopically affecting gut morphology or physiology. Moreover, the shorter protocol caused an increased IL-4 production and a more selective antigen-specific IgG1 response. Finally, the extended CT administration during the sensitization period of the conventional protocol is responsible for the exacerbated immune response observed in that model. Therefore, the new model presented here allows a reduction not only in experimental time but also in the number of animals required per experiment while maintaining the features of conventional allergy models. We propose that the new protocol reported will contribute to advancing allergy research. Copyright © 2012 Elsevier B.V. All rights reserved.

Geospatial exposure to point-of-sale tobacco: real-time craving and smoking-cessation outcomes.

Science.gov (United States)

Kirchner, Thomas R; Cantrell, Jennifer; Anesetti-Rothermel, Andrew; Ganz, Ollie; Vallone, Donna M; Abrams, David B

2013-10-01

Little is known about the factors that drive the association between point-of-sale marketing and behavior, because methods that directly link individual-level use outcomes to real-world point-of-sale exposure are only now beginning to be developed. Daily outcomes during smoking cessation were examined as a function of both real-time geospatial exposure to point-of-sale tobacco (POST) and subjective craving to smoke. Continuous individual geospatial location data collected over the first month of a smoking-cessation attempt in 2010-2012 (N=475) were overlaid on a POST outlet geodatabase (N=1060). Participants' mobility data were used to quantify the number of times they came into contact with a POST outlet. Participants recorded real-time craving levels and smoking status via ecological momentary assessment (EMA) on cellular telephones. The final data set spanned a total of 12,871 days of EMA and geospatial tracking. Lapsing was significantly more likely on days with any POST contact (OR=1.19, 95% CI=1.18, 1.20), and increasingly likely as the number of daily POST contacts increased (OR=1.07, 95% CI=1.06, 1.08). Overall, daily POST exposure was significantly associated with lapsing when craving was low (OR=1.22, 95% CI=1.20, 1.23); high levels of craving were more directly associated with lapse outcomes. These data shed light on the way mobility patterns drive a dynamic interaction between individuals and the POST environment, demonstrating that quantification of individuals' exposure to POST marketing can be used to identify previously unrecognized patterns of association among individual mobility, the built environment, and behavioral outcomes. © 2013 American Journal of Preventive Medicine.

Transient anhedonia phenotype and altered circadian timing of behaviour during night-time dim light exposure in Per3-/- mice, but not wildtype mice.

Science.gov (United States)

Martynhak, Bruno Jacson; Hogben, Alexandra L; Zanos, Panos; Georgiou, Polymnia; Andreatini, Roberto; Kitchen, Ian; Archer, Simon N; von Schantz, Malcolm; Bailey, Alexis; van der Veen, Daan R

2017-01-10

Industrialisation greatly increased human night-time exposure to artificial light, which in animal models is a known cause of depressive phenotypes. Whilst many of these phenotypes are 'direct' effects of light on affect, an 'indirect' pathway via altered sleep-wake timing has been suggested. We have previously shown that the Period3 gene, which forms part of the biological clock, is associated with altered sleep-wake patterns in response to light. Here, we show that both wild-type and Per3 -/- mice showed elevated levels of circulating corticosterone and increased hippocampal Bdnf expression after 3 weeks of exposure to dim light at night, but only mice deficient for the PERIOD3 protein (Per3 -/- ) exhibited a transient anhedonia-like phenotype, observed as reduced sucrose preference, in weeks 2-3 of dim light at night, whereas WT mice did not. Per3 -/- mice also exhibited a significantly smaller delay in behavioural timing than WT mice during weeks 1, 2 and 4 of dim light at night exposure. When treated with imipramine, neither Per3 -/- nor WT mice exhibited an anhedonia-like phenotype, and neither genotypes exhibited a delay in behavioural timing in responses to dLAN. While the association between both Per3 -/- phenotypes remains unclear, both are alleviated by imipramine treatment during dim night-time light.

A theoretical study for the real-time assessment of external gamma exposure using equivalent-volume numerical integration

International Nuclear Information System (INIS)

Han, Moon Hee

1995-02-01

An approximate method for estimating gamma external dose due to an arbitrary distribution of radioactive material has been developed. For the assessment of external gamma dose, the space over which radioactive material is distributed has been assumed to be composed of hexagonal cells. The evaluation of three-dimensional integration over the space is an extremely time-consuming task. Hence, a different approach has been used for the study, i.e., a equivalent-volume spherical approach in which a regular hexahedron is modeled as a equivalent-volume sphere to simplify the integration. For the justification of the current approach, two case studies have been performed: a comparison with a point source approximation and a comparison of external dose rate with the Monte Carlo integration. These comparisons show that the current approach gives reasonable results in a physical sense. Computing times of the developed and Monte Carlo integration method on VAX system have been compared as a function of the number of hexagonal cells. This comparison shows that CPU times for both methods are comparable in the region of small number of cells, but in the region of large number, Monte Carlo integration needs much more computing times. The proposed method is shown to have an accuracy equivalent to Monte Carlo method with an advantage of much shorter calculation time. Then, the method developed here evaluates early off-site consequences of a nuclear accident. An accident consequence assessment model has been integrated using Gaussian puff model which is used to obtain the distribution of radioactive material in the air and on the ground. For this work, the real meteorological data measured at Kori site for 10 years (1976 - 1985) have been statistically analyzed for obtaining site-specific conditions. The short-term external gamma exposures have been assessed for several site-specific meteorological conditions. The results show that the extent and the pattern of short-term external

Real-time measurement of dust in the workplace using video exposure monitoring: Farming to pharmaceuticals

International Nuclear Information System (INIS)

Walsh, P T; Forth, A R; Clark, R D R; Dowker, K P; Thorpe, A

2009-01-01

Real-time, photometric, portable dust monitors have been employed for video exposure monitoring (VEM) to measure and highlight dust levels generated by work activities, illustrate dust control techniques, and demonstrate good practice. Two workplaces, presenting different challenges for measurement, were used to illustrate the capabilities of VEM: (a) poultry farming activities and (b) powder transfer operations in a pharmaceutical company. For the poultry farm work, the real-time monitors were calibrated with respect to the respirable and inhalable dust concentrations using cyclone and IOM reference samplers respectively. Different rankings of exposure for typical activities were found on the small farm studied here compared to previous exposure measurements at larger poultry farms: these were mainly attributed to the different scales of operation. Large variations in the ratios of respirable, inhalable and real-time monitor TWA concentrations of poultry farm dust for various activities were found. This has implications for the calibration of light-scattering dust monitors with respect to inhalable dust concentration. In the pharmaceutical application, the effectiveness of a curtain barrier for dust control when dispensing powder in a downflow booth was rapidly demonstrated.

Mechanistic models for cancer development after short time radiation exposure

International Nuclear Information System (INIS)

Kottbauer, M. M.

1997-12-01

In this work two biological based models were developed. First the single-hit model for solid tumors (SHM-S) and second the single-hit model for leukemia (SHM-L). These models are a further development of the Armitage-Doll model for the special case of a short time radiation exposure. The basis of the models is the multistage process of carcinogeneses. The single-hit models provide simultaneously the age-dependent cancer-rate of spontaneous and radiation induced tumors as well as the dose-effect relationships at any age after exposure. The SHM-S leads to a biological based dose-effect relationship, which is similar to the relative risk model suggested by the ICRP 60. The SHM-S describes the increased mortality rate of the bomb survivors more accurate than the relative risk model. The SHM-L results in an additive dose-effect relationship. It is shown that only small differences in the derivation of the two models lead to the two dose-effect relationships. Beside the radiation exposure the new models consider the decrease of the cancer mortality rate at higher ages (age>75) which can be traced back mainly to three causes: competitive causes of death, reduction of cell proliferation and reduction of risk groups. The single-hit models also consider children cancer, the different rates of incidence and mortality, influence of the immune system and the cell-killing effect. (author)

Using smartphones to collect time-activity data for long-term personal-level air pollution exposure assessment.

Science.gov (United States)

Glasgow, Mark L; Rudra, Carole B; Yoo, Eun-Hye; Demirbas, Murat; Merriman, Joel; Nayak, Pramod; Crabtree-Ide, Christina; Szpiro, Adam A; Rudra, Atri; Wactawski-Wende, Jean; Mu, Lina

2016-06-01

Because of the spatiotemporal variability of people and air pollutants within cities, it is important to account for a person's movements over time when estimating personal air pollution exposure. This study aimed to examine the feasibility of using smartphones to collect personal-level time-activity data. Using Skyhook Wireless's hybrid geolocation module, we developed "Apolux" (Air, Pollution, Exposure), an Android(TM) smartphone application designed to track participants' location in 5-min intervals for 3 months. From 42 participants, we compared Apolux data with contemporaneous data from two self-reported, 24-h time-activity diaries. About three-fourths of measurements were collected within 5 min of each other (mean=74.14%), and 79% of participants reporting constantly powered-on smartphones (n=38) had a daily average data collection frequency of <10 min. Apolux's degree of temporal resolution varied across manufacturers, mobile networks, and the time of day that data collection occurred. The discrepancy between diary points and corresponding Apolux data was 342.3 m (Euclidian distance) and varied across mobile networks. This study's high compliance and feasibility for data collection demonstrates the potential for integrating smartphone-based time-activity data into long-term and large-scale air pollution exposure studies.

Effect of reduced exposure times on the cytotoxicity of resin luting cements cured by high-power led

Directory of Open Access Journals (Sweden)

Gulfem Ergun

2011-06-01

Full Text Available OBJECTIVE: Applications of resin luting agents and high-power light-emitting diodes (LED light-curing units (LCUs have increased considerably over the last few years. However, it is not clear whether the effect of reduced exposure time on cytotoxicity of such products have adequate biocompatibility to meet clinical success. This study aimed at assessing the effect of reduced curing time of five resin luting cements (RLCs polymerized by high-power LED curing unit on the viability of a cell of L-929 fibroblast cells. MATERIAL AND METHODS: Disc-shaped samples were prepared in polytetrafluoroethylene moulds with cylindrical cavities. The samples were irradiated from the top through the ceramic discs and acetate strips using LED LCU for 20 s (50% of the manufacturer's recommended exposure time and 40 s (100% exposure time. After curing, the samples were transferred into a culture medium for 24 h. The eluates were obtained and pipetted onto L-929 fibroblast cultures (3x10(4 per well and incubated for evaluating after 24 h. Measurements were performed by dimethylthiazol diphenyltetrazolium assay. Statistical significance was determined by two-way ANOVA and two independent samples were compared by t-test. RESULTS: Results showed that eluates of most of the materials polymerized for 20 s (except Rely X Unicem and Illusion reduced to a higher extent cell viability compared to samples of the same materials polymerized for 40 s. Illusion exhibited the least cytotoxicity for 20 s exposure time compared to the control (culture without samples followed by Rely X Unicem and Rely X ARC (90.81%, 88.90%, and 83.11%, respectively. For Rely X ARC, Duolink and Lute-It 40 s exposure time was better (t=-1.262 p=0,276; t=-9.399 p=0.001; and t=-20.418 p<0.001, respectively. CONCLUSION: The results of this study suggest that reduction of curing time significantly enhances the cytotoxicity of the studied resin cement materials, therefore compromising their clinical

Reconstructing the life-time lead exposure in children using dentine in deciduous teeth

Energy Technology Data Exchange (ETDEWEB)

Shepherd, Thomas J., E-mail: shepherdtj@aol.com [School of Earth and Environment, University of Leeds, Leeds LS2 9JT (United Kingdom); Dirks, Wendy [Centre for Oral Health Research, School of Dental Sciences, Newcastle University, Newcastle upon Tyne NE2 4BW (United Kingdom); Manmee, Charuwan; Hodgson, Susan [Institute of Health and Society, Newcastle University, Newcastle upon Tyne NE2 4AX (United Kingdom); Banks, David A. [School of Earth and Environment, University of Leeds, Leeds LS2 9JT (United Kingdom); Averley, Paul [Centre for Oral Health Research, School of Dental Sciences, Newcastle University, Newcastle upon Tyne NE2 4BW (United Kingdom); Queensway Dental Practice, 170 Queensway, Billingham, Teesside TS23 2NT (United Kingdom); Pless-Mulloli, Tanja [Institute of Health and Society, Newcastle University, Newcastle upon Tyne NE2 4AX (United Kingdom); Newcastle Institute for Research on Sustainability, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

2012-05-15

Data are presented to demonstrate that the circumpulpal dentine of deciduous teeth can be used to reconstruct a detailed record of childhood exposure to lead. By combining high spatial resolution laser ablation ICP-MS with dental histology, information was acquired on the concentration of lead in dentine from in utero to several years after birth, using a true time template of dentine growth. Time corrected lead analyses for pairs of deciduous molars confirmed that between-tooth variation for the same child was negligible and that meaningful exposure histories can be obtained from a single, multi-point ablation transect on longitudinal sections of individual teeth. For a laser beam of 100 {mu}m diameter, the lead signal for each ablation point represented a time span of 42 days. Simultaneous analyses for Sr, Zn and Mg suggest that the incorporation of Pb into dentine (carbonated apatite) is most likely controlled by nanocrystal growth mechanisms. The study also highlights the importance of discriminating between primary and secondary dentine and the dangers of translating lead analyses into blood lead estimates without determining the age or duration of dentine sampled. Further work is in progress to validate deciduous teeth as blood lead biomarkers. - Highlights: Black-Right-Pointing-Pointer Reconstruction of childhood exposure history to Pb using deciduous tooth dentine. Black-Right-Pointing-Pointer Pb analyses acquired for dentine growth increments of 42 days. Black-Right-Pointing-Pointer Highly correlated Pb concentration profiles for pairs of deciduous molars. Black-Right-Pointing-Pointer Data for Sr, Zn and Mg provide a model for the incorporation of Pb into dentine.

Reconstructing the life-time lead exposure in children using dentine in deciduous teeth

International Nuclear Information System (INIS)

Shepherd, Thomas J.; Dirks, Wendy; Manmee, Charuwan; Hodgson, Susan; Banks, David A.; Averley, Paul; Pless-Mulloli, Tanja

2012-01-01

Data are presented to demonstrate that the circumpulpal dentine of deciduous teeth can be used to reconstruct a detailed record of childhood exposure to lead. By combining high spatial resolution laser ablation ICP-MS with dental histology, information was acquired on the concentration of lead in dentine from in utero to several years after birth, using a true time template of dentine growth. Time corrected lead analyses for pairs of deciduous molars confirmed that between-tooth variation for the same child was negligible and that meaningful exposure histories can be obtained from a single, multi-point ablation transect on longitudinal sections of individual teeth. For a laser beam of 100 μm diameter, the lead signal for each ablation point represented a time span of 42 days. Simultaneous analyses for Sr, Zn and Mg suggest that the incorporation of Pb into dentine (carbonated apatite) is most likely controlled by nanocrystal growth mechanisms. The study also highlights the importance of discriminating between primary and secondary dentine and the dangers of translating lead analyses into blood lead estimates without determining the age or duration of dentine sampled. Further work is in progress to validate deciduous teeth as blood lead biomarkers. - Highlights: ► Reconstruction of childhood exposure history to Pb using deciduous tooth dentine. ► Pb analyses acquired for dentine growth increments of 42 days. ► Highly correlated Pb concentration profiles for pairs of deciduous molars. ► Data for Sr, Zn and Mg provide a model for the incorporation of Pb into dentine.

Long-Term Costs and Health Consequences of Issuing Shorter Duration Prescriptions for Patients with Chronic Health Conditions in the English NHS.

Science.gov (United States)

Martin, Adam; Payne, Rupert; Wilson, Edward Cf

2018-06-01

The National Health Service (NHS) in England spends over £9 billion on prescription medicines dispensed in primary care, of which over two-thirds is accounted for by repeat prescriptions. Recently, GPs in England have been urged to limit the duration of repeat prescriptions, where clinically appropriate, to 28 days to reduce wastage and hence contain costs. However, shorter prescriptions will increase transaction costs and thus may not be cost saving. Furthermore, there is evidence to suggest that shorter prescriptions are associated with lower adherence, which would be expected to lead to lower clinical benefit. The objective of this study is to estimate the cost-effectiveness of 3-month versus 28-day repeat prescriptions from the perspective of the NHS. We adapted three previously developed UK policy-relevant models, incorporating transaction (dispensing fees, prescriber time) and drug wastage costs associated with 3-month and 28-day prescriptions in three case studies: antihypertensive medications for prevention of cardiovascular events; drugs to improve glycaemic control in patients with type 2 diabetes; and treatments for depression. In all cases, 3-month prescriptions were associated with lower costs and higher QALYs than 28-day prescriptions. This is driven by assumptions that higher adherence leads to improved disease control, lower costs and improved QALYs. Longer repeat prescriptions may be cost-effective compared with shorter ones. However, the quality of the evidence base on which this modelling is based is poor. Any policy rollout should be within the context of a trial such as a stepped-wedge cluster design.

Dyslexics' faster decay of implicit memory for sounds and words is manifested in their shorter neural adaptation.

Science.gov (United States)

Jaffe-Dax, Sagi; Frenkel, Or; Ahissar, Merav

2017-01-24

Dyslexia is a prevalent reading disability whose underlying mechanisms are still disputed. We studied the neural mechanisms underlying dyslexia using a simple frequency-discrimination task. Though participants were asked to compare the two tones in each trial, implicit memory of previous trials affected their responses. We hypothesized that implicit memory decays faster among dyslexics. We tested this by increasing the temporal intervals between consecutive trials, and by measuring the behavioral impact and ERP responses from the auditory cortex. Dyslexics showed a faster decay of implicit memory effects on both measures, with similar time constants. Finally, faster decay of implicit memory also characterized the impact of sound regularities in benefitting dyslexics' oral reading rate. Their benefit decreased faster as a function of the time interval from the previous reading of the same non-word. We propose that dyslexics' shorter neural adaptation paradoxically accounts for their longer reading times, since it reduces their temporal window of integration of past stimuli, resulting in noisier and less reliable predictions for both simple and complex stimuli. Less reliable predictions limit their acquisition of reading expertise.

Prime-time television exposure to high priority school-aged social-developmental issues.

Science.gov (United States)

Suzuki, Sherrie; Itano, Davin; Yamamoto, Loren G

2008-03-01

The purpose of this study is to quantify the material children and adolescents are exposed to while watching prime-time television so that school educators, health professionals, and parents can focus on issues of maximum exposure that must be addressed. Prime-time programming was recorded from 7 p.m. to 10 p.m. Hawaiian Standard Time daily for 2 weeks in July 2005. Recordings were then viewed to identify social behaviors of interest. Each hour on average, sex was referenced 1.8 times, drugs 0.6 times, tobacco 0.3 times, alcohol 2.4 times, and violence/crime 6.0 times per network. Messages advocating exercise, anti-drug advocacy, and anti-smoking advocacy were each shown 0.2 times per hour; while anti-alcohol advocacy was shown 0.1 times per hour. School educators, health professionals, and parents must recognize that prime-time television frequently exposes viewers to issues that are of critical importance to the health and social development of school-aged children and adolescents.

Objectivized evaluation of surgeons exposure to radiofrequency electromagnetic fields – In the context of exposure duration and polish and new international requirements regarding workers protection

Directory of Open Access Journals (Sweden)

Jolanta Karpowicz

2013-08-01

Full Text Available Background: Use of electro surgery units (ESU in surgeries is linked with electromagnetic field emission, which is assessed according to the requirements of occupational health and safety legislation. Material and Methods: Surgeons' exposure characteristics was monitored during 11 surgeries (proctectomy, patency of artery, hepatectomy, cystectomy, tonsilectomy, laparoscopy by real time of monopolar ESU activity recorder. Investigations of root-mean-square value of electric and magnetic field strength was also performed at various modes of ESU operations during cutting (output power, 55-150 W; frequency, 330-445 kHz and coagulating (40-240 W, 335-770 kHz. Statistical parameters of distribution of ESU operation over any 6-min periods (according to international requirements regarding protection against adverse thermal effects of electromagnetic field were assessed. Results: Electric field strength, measured 10 cm from the cable supplying an active electrode was 147-675 V/m during cutting and 297-558 V/m during coagulating; magnetic field strength was less than 0.2 A/m in both modes. Monitoring of ESUs showed the following ranges of their operation during surgeries 5-66% of time over starting 3 min of surgery, 3-40% over starting 6 min, and the distribution of their use over any 6-min periods 0-12% (median / 7-43% (maximum value. Conclusions: The real operation time of ESUs wykoduring surgeries was significantly shorter than that declared by workers. The distance of at least 15 cm between cables, connecting electrodes with generator and workers meets the requirements of the Polish legislation on permissible exposure limits. The assessment of localized exposure of the hand needs a detailed analysis of the SAR ratio distribution and further studies are required. Med Pr 2013;64(4:487–501

Acute Exposure Guideline Levels (AEGLs) for Time Varying Toxic Plumes

Science.gov (United States)

2014-09-12

loading rates between the density values given as Arho(b-1,k) and Arho(b,k). The line labeled ‘ extrap .’above b = 1 in Table 3 records the derived...exposure times and an inverse quadratic law for densities lower than 8.26 mg/m3. The line labeled ‘ extrap .’ at the bottom of the table gives the...6 (labeled “ extrap .” above) are simply duplicated from the adjacent band b = 5. This exponent is also used to define the lowest density value Brho

A preliminary estimate of the EUVE cumulative distribution of exposure time on the unit sphere. [Extreme Ultra-Violet Explorer

Science.gov (United States)

Tang, C. C. H.

1984-01-01

A preliminary study of an all-sky coverage of the EUVE mission is given. Algorithms are provided to compute the exposure of the celestial sphere under the spinning telescopes, taking into account that during part of the exposure time the telescopes are blocked by the earth. The algorithms are used to give an estimate of exposure time at different ecliptic latitudes as a function of the angle of field of view of the telescope. Sample coverage patterns are also given for a 6-month mission.

Contribution of time-activity pattern and microenvironment to black carbon (BC) inhalation exposure and potential internal dose among elementary school children

Science.gov (United States)

Jeong, Hyeran; Park, Donguk

2017-09-01

The aims of this study were to quantify the contributions of activities or microenvironments (MEs) to daily total exposure to and potential dose of black carbon (BC). Daily BC exposures (24-h) were monitored using a micro-aethalometer micoAeth AE51 with forty school-aged children living in an urban area in Korea from August 2015 to January 2016. The children's time-activity patterns and the MEs they visited were investigated by means of a time-activity diary (TAD) and follow-up interviews with the children and their parents. Potential inhaled dose was estimated by multiplying the airborne BC concentrations (μg/m3) we monitored for the time the children spent in a particular ME by the inhalation rate (IR, m3/h) for the time-activity performed. The contribution of activities and MEs to overall daily exposure to and potential dose of BC was quantified. Overall mean daily potential dose was equal to 24.1 ± 10.6 μg/day (range: 6.6-46.3 μg/day). The largest contribution to BC exposure and potential dose (51.9% and 41.7% respectively) occurred in the home thanks to the large amount of time spent there. Transportation was where children received the most intense exposure to (14.8%) and potential dose (20.2%) of BC, while it accounted for 7.6% of daily time. School on weekdays during the semester was responsible for 20.3% of exposure and 22.5% of potential dose. Contribution to BC exposure and potential dose was altered by several time-activity parameters, such as type of day (weekdays vs. weekends; school days vs. holidays), season, and gender. Traveling by motor vehicle and subway showed more elevated exposure or potential dose intensity on weekdays or school days, probably influenced by the increased surrounding traffic volumes on these days compared to on weekends or holidays. This study may be used to prioritize targets for minimizing children's exposure to BC and to indicate outcomes of BC control strategies.

Effect of smoking on the radon risk in dependence on the time elapsed from exposure

International Nuclear Information System (INIS)

Boehm, Radoslav; Holy, Karol; Sedlak, A.

2013-01-01

The synergistic effect of cigarette smoking and radon exposure on the lung cancer risk was assessed by using the threshold energy model, which allows the biological effects of radon daughter products on the lung tissue to be analyzed. The shape of the curves describing the relation between the risk and the time after exposure was estimated. The change in the lung function caused by chronic smoking was considered in the calculations. (orig.)

The effects of various exposure times in the detectability on the tips of the endodontic files in Digora

International Nuclear Information System (INIS)

Ko, Jee Young; Park, Chang Seo

1997-01-01

Digora-an intraoral digital radiography system utilizing image plate(IP) - has a dynamic range of exposure time which allows it to decrease the patient's exposure time and to increase diagnostic ability through image process sing, transmission and storage. The purpose of this study was to evaluate the Digora system by assessing the effects of various exposure times on the detectability on the tip of the endodontic file. Examining the root canals of 45 extracted sound premolars, K-files No. 10, 15, and 20 were placed at slightly varying distances from the apex. The teeth were glued onto resin-pla ster blocks. Five exposure times varying between 0.01 seconds and 0.25 seconds were used. Four observers were asked to measure the distance between the tip of the file and a reduction of crown portion, and obtained mean errors (subtracting true file length from the measured file length), comparing Digora monitors with E-plus films, which were both obtained under the same geometrical positions. The results were as follows : 1. Comparing E-plus film with Digora at 0.01 seconds, the mean errors in E-plus film showed -4.453 mm, -4.497 mm, and -3.857 mm, while the mean errors in Digora showed 0.065 mm, 0.607 mm, and 0.719 mm according to the file groups. Therefore there was a significant difference between E-plus film and Digora (P<0.05). 2. By comparison of mean errors according to the various exposure times in the Digora system, the mean error at standard deviation was the highest at 0.01 seconds was significantly lower than that at 0.12 and 0.25 seconds in No. 10 and 20 file group (P<0.05). and the standard deviation was the highest at 0.01 seconds. 3. Comparing E-plus film at 0.25 seconds with the Digora system, the mean errors showed a significant difference between E-plus at 0.25 seconds and the Digora system at 0.25 seconds in No. 10 and 20 file groups (P<0.05). 4. Comparing E-plus film at 0.25 seconds and E-plus film at 0.01 and 0.03 seconds in 10 file group (P<0.05). In

Incorporation of glucose carbons into rat lung lipids after exposure to 0.6 ppm ozone

International Nuclear Information System (INIS)

Bassett, D.J.; Rabinowitz, J.L.

1985-01-01

Continuous exposure to low concentrations of ozone has previously been associated with proliferation of lung alveolar type II epithelial cells. In this study, 14 C incorporation into tissue lipids was determined in isolated rat lungs by perfusion with [U- 14 C]glucose, at a time of maximal hyperplasia brought about by 3 days continuous exposure to 0.6 ppm ozone. Ozone exposed lungs exhibited increased rates of glycolytic energy production, indicated by an 89% increase in 3 H 2 O generation on perfusion with [5-3H]glucose. Ozone exposure resulted in enhanced 14 C incorporations into glyceride-glycerol and fatty acid moieties of lung lipids of 95 and 180%, respectively, with a greater proportion of label being recovered in shorter chain fatty acids. Although increased labeling was observed in both neutral and phospholipids, the pattern of 14 C recovery suggested a relative increased glucose carbon incorporation into lung free fatty acids, phosphatidic acid, and such membrane associated lipids as phosphatidylinositol and those containing sphingosine. These results are consistent with the needs of a dividing cell population for enhanced energy production and synthesis of new lipids

Seasonal correction factors in radon exposure assessment: are they help or hindrance?

International Nuclear Information System (INIS)

Denman, A.R.; Groves-Kirkby, C.J.; Phillips, P.S.; Woolridge, A.C.; Crockett, R.G.M.

2008-01-01

Northern Hemisphere radon levels are generally higher in Winter than in Summer, primarily due to the increased interior/exterior temperature difference during the heating season, which results in greater atmospheric pressure differential and enhanced radon ingress. Following a survey of domestic radon levels in the United Kingdom (UK), the former National Radiological Protection Board (NRPB) established measurement protocols and promulgated nationally-applicable Seasonal Correction Factors (SCF). These factors convert a one-month or three-month radon concentration measurement, commencing in any month of the year, to an annual mean radon concentration. Subsequent study suggests that this approach may not be sufficiently sensitive to local conditions, and a major independent investigation reported seasonal correction factors specific to nine geographic regions, together with a composite set applicable to all regions. Similar geographical variability has been observed in other countries. In a recent evaluation of the applicability of short-term exposures in quantifying long-term domestic radon levels, radon levels in 34 houses were monitored over a 12-month period with 1-week, 1-month and 3-month exposures. Radon concentration variation departed significantly from that expected on the basis of the recommended SCFs, with year-end discontinuities at all exposure durations. Weekly monitoring with electrets was continued in three of these locations for four years. Short-term variations in radon levels were observed, particularly during the shorter exposures, and this dataset has also shown year-on-year variations. Overall, SCFs derived from this dataset are significantly lower than those recommended, but are comparable with other results from the UK and elsewhere, particularly those that recognise geological diversity and are consequently prepared on a regional rather than a national basis. These findings call into question the validity of using nationally

A time-series study of sick building syndrome: chronic, biotoxin-associated illness from exposure to water-damaged buildings.

Science.gov (United States)

Shoemaker, Ritchie C; House, Dennis E

2005-01-01

The human health risk for chronic illnesses involving multiple body systems following inhalation exposure to the indoor environments of water-damaged buildings (WDBs) has remained poorly characterized and the subject of intense controversy. The current study assessed the hypothesis that exposure to the indoor environments of WDBs with visible microbial colonization was associated with illness. The study used a cross-sectional design with assessments at five time points, and the interventions of cholestyramine (CSM) therapy, exposure avoidance following therapy, and reexposure to the buildings after illness resolution. The methodological approach included oral administration of questionnaires, medical examinations, laboratory analyses, pulmonary function testing, and measurements of visual function. Of the 21 study volunteers, 19 completed assessment at each of the five time points. Data at Time Point 1 indicated multiple symptoms involving at least four organ systems in all study participants, a restrictive respiratory condition in four participants, and abnormally low visual contrast sensitivity (VCS) in 18 participants. Serum leptin levels were abnormally high and alpha melanocyte stimulating hormone (MSH) levels were abnormally low. Assessments at Time Point 2, following 2 weeks of CSM therapy, indicated a highly significant improvement in health status. Improvement was maintained at Time Point 3, which followed exposure avoidance without therapy. Reexposure to the WDBs resulted in illness reacquisition in all participants within 1 to 7 days. Following another round of CSM therapy, assessments at Time Point 5 indicated a highly significant improvement in health status. The group-mean number of symptoms decreased from 14.9+/-0.8 S.E.M. at Time Point 1 to 1.2+/-0.3 S.E.M., and the VCS deficit of approximately 50% at Time Point 1 was fully resolved. Leptin and MSH levels showed statistically significant improvement. The results indicated that CSM was an effective

The role of romantic attraction and conflict resolution in predicting shorter and longer relationship maintenance among adolescents.

Science.gov (United States)

Appel, Israel; Shulman, Shmuel

2015-04-01

This study examined the role of romantic attraction and conflict resolution patterns in shorter and longer relationship maintenance among adolescent couples. Data were used from 55 couples aged 15-18 years. Partners completed the Romantic Attraction scale and were observed negotiating a disagreement. Three and 6 months later, they were asked to report whether they were still together. Findings indicated that partners' romantic attraction and the tendency to minimize disagreements during interaction predicted shorter relationship maintenance. In contrast, longer relationship maintenance was predicted by partners' capability to resolve conflicts constructively in a positive atmosphere. Findings are embedded and discussed within Fisher's (2004) evolutionary theory of love.

Shorter Decentralized Attribute-Based Encryption via Extended Dual System Groups

Directory of Open Access Journals (Sweden)

Jie Zhang

2017-01-01

Full Text Available Decentralized attribute-based encryption (ABE is a special form of multiauthority ABE systems, in which no central authority and global coordination are required other than creating the common reference parameters. In this paper, we propose a new decentralized ABE in prime-order groups by using extended dual system groups. We formulate some assumptions used to prove the security of our scheme. Our proposed scheme is fully secure under the standard k-Lin assumption in random oracle model and can support any monotone access structures. Compared with existing fully secure decentralized ABE systems, our construction has shorter ciphertexts and secret keys. Moreover, fast decryption is achieved in our system, in which ciphertexts can be decrypted with a constant number of pairings.

Timing of first exposure to maternal depression and adolescent emotional disorder in a national Canadian cohort.

Directory of Open Access Journals (Sweden)

Kiyuri Naicker

Full Text Available Correlations have been reported between behavioral and cognitive outcomes in adolescence and exposure to maternal depression during the first postpartum year, but the effects of timing of maternal depression during subsequent exposure periods have rarely been controlled for. This study aims to methodically investigate the importance of timing of initial exposure to maternal depression with respect to adolescent mental health outcomes.This study used data on 937 children from the National Longitudinal Study of Children and Youth (NLSCY, a nationally-representative longitudinal survey established in 1994 by Statistics Canada. Ordinal logistic regression was used to confirm associations between adolescent emotional disorder (at 12-13 years and initial exposure to maternal depression during 2-year intervals from birth to adolescence. Following their initial exposure to maternal depression, children were dropped from subsequent cycles. Stressful life events, chronic health conditions, maternal alcohol use, maternal marital status, gender, and SES were included as covariates.The results indicated that adolescents who were initially exposed to maternal depression between the ages of 2-3 years and 4-5 years had a two-fold increase in odds of emotional disorder. No increase in odds was observed in those initially exposed during the first postpartum year or later in childhood.The results demonstrate that a sensitive period of initial exposure to maternal depression may occur between the ages of 2 and 5, and not during the first year of life indicated by previous research. These findings are congruent with the literature on emotional and behavioral development in early childhood.

Avoidance test with Enchytraeus albidus (Enchytraeidae): Effects of different exposure time and soil properties

International Nuclear Information System (INIS)

Amorim, Monica J.B.; Novais, Sara; Roembke, Joerg; Soares, Amadeu M.V.M.

2008-01-01

Enchytraeids are ecologically relevant soil species and are commonly used in standardized toxicity tests. Their rapid reaction to a chemical exposure can be used as a toxicological measurement endpoint that assesses the avoidance behavior. The objectives of this investigation were to determine the effects of soil properties on the avoidance behavior of Enchytraeus albidus and to optimize the duration of avoidance test. The avoidance tests included (1) exposures in OECD artificial soil with standard or modified properties (pH, clay or peat content), and (2) exposures to copper chloride, cadmium chloride, and to the organic pesticides dimethoate and phenmedipham for different time periods. Results showed that alteration of OECD soil constituents significantly affected the avoidance behavior of enchytraeids, and that the 48-h exposure was the optimal duration of the test. Consideration of soil properties is important for selecting appropriate experimental design and interpreting the results of the enchytraeid avoidance test. - Optimal duration of the avoidance tests with potworm Enchytraeus albidus is 48 h; soil properties can affect performance of the test species

Temporal properties of fear extinction--does time matter?

Science.gov (United States)

Golkar, Armita; Bellander, Martin; Öhman, Arne

2013-02-01

Fear extinction can be defined as the weakening of the expression of a conditioned response (CR) by extended experience of nonreinforcement. Conceptually, two distinct models have been invoked to account for extinction. R. A. Rescorla and A. R. Wagner (1972, A theory of Pavlovian conditioning: Variations in the effectiveness of reinforcement and nonreinforcement, in A. H. B. W. F. Prokasy (Ed.), Classical conditioning: II. Current research and theory, pp. 64-99, New York, NY, Appleton-Century-Crofts) postulated that the number of exposure trials is the primary determinant of CR decrement, whereas C. R. Gallistel and J. Gibbon (2000, Time, rate, and conditioning, Psychological Review, Vol. 107, pp. 289-344) proposed that the decisive event is the cumulated exposure time to the nonreinforced conditioned stimulus (CS) elapsed after the last CS reinforcement. We evaluated these two accounts in a human differential fear conditioning study in which CR was measured with the fear-potentiated startle response. Cumulated duration of nonreinforcement fails to explain our findings, whereas the number of trials appeared critical. In fact, many CS trials with a duration shorter than the acquisition CS duration facilitated within-session extinction, but this effect did not predict the recovery of fear. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

Marital disruption is associated with shorter salivary telomere length in a probability sample of older adults.

Science.gov (United States)

Whisman, Mark A; Robustelli, Briana L; Sbarra, David A

2016-05-01

Marital disruption (i.e., marital separation, divorce) is associated with a wide range of poor mental and physical health outcomes, including increased risk for all-cause mortality. One biological intermediary that may help explain the association between marital disruption and poor health is accelerated cellular aging. This study examines the association between marital disruption and salivary telomere length in a United States probability sample of adults ≥50 years of age. Participants were 3526 individuals who participated in the 2008 wave of the Health and Retirement Study. Telomere length assays were performed using quantitative real-time polymerase chain reaction (qPCR) on DNA extracted from saliva samples. Health and lifestyle factors, traumatic and stressful life events, and neuroticism were assessed via self-report. Linear regression analyses were conducted to examine the associations between predictor variables and salivary telomere length. Based on their marital status data in the 2006 wave, people who were separated or divorced had shorter salivary telomeres than people who were continuously married or had never been married, and the association between marital disruption and salivary telomere length was not moderated by gender or neuroticism. Furthermore, the association between marital disruption and salivary telomere length remained statistically significant after adjusting for demographic and socioeconomic variables, neuroticism, cigarette use, body mass, traumatic life events, and other stressful life events. Additionally, results revealed that currently married adults with a history of divorce evidenced shorter salivary telomeres than people who were continuously married or never married. Accelerated cellular aging, as indexed by telomere shortening, may be one pathway through which marital disruption is associated with morbidity and mortality. Copyright © 2016 Elsevier Ltd. All rights reserved.

The return trip is felt shorter only postdictively: A psychophysiological study of the return trip effect [corrected].

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Ryosuke Ozawa

Full Text Available The return trip often seems shorter than the outward trip even when the distance and actual time are identical. To date, studies on the return trip effect have failed to confirm its existence in a situation that is ecologically valid in terms of environment and duration. In addition, physiological influences as part of fundamental timing mechanisms in daily activities have not been investigated in the time perception literature. The present study compared round-trip and non-round-trip conditions in an ecological situation. Time estimation in real time and postdictive estimation were used to clarify the situations where the return trip effect occurs. Autonomic nervous system activity was evaluated from the electrocardiogram using the Lorenz plot to demonstrate the relationship between time perception and physiological indices. The results suggest that the return trip effect is caused only postdictively. Electrocardiographic analysis revealed that the two experimental conditions induced different responses in the autonomic nervous system, particularly in sympathetic nervous function, and that parasympathetic function correlated with postdictive timing. To account for the main findings, the discrepancy between the two time estimates is discussed in the light of timing strategies, i.e., prospective and retrospective timing, which reflect different emphasis on attention and memory processes. Also each timing method, i.e., the verbal estimation, production or comparative judgment, has different characteristics such as the quantification of duration in time units or knowledge of the target duration, which may be responsible for the discrepancy. The relationship between postdictive time estimation and the parasympathetic nervous system is also discussed.

Exposure to time varying magnetic fields associated with magnetic resonance imaging reduces fentanyl-induced analgesia in mice

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Teskey, G.C.; Prato, F.S.; Ossenkopp, K.P.; Kavaliers, M.

1988-01-01

The effects of exposure to clinical magnetic resonance imaging (MRI) on analgesia induced by the mu opiate agonist, fentanyl, was examined in mice. During the dark period, adult male mice were exposed for 23.2 min to the time-varying (0.6 T/sec) magnetic field (TVMF) component of the MRI procedure. Following this exposure, the analgesic potency of fentanyl citrate (0.1 mg/kg) was determined at 5, 10, 15, and 30 min post-injection, using a thermal test stimulus (hot-plate 50 degrees C). Exposure to the magnetic-field gradients attenuated the fentanyl-induced analgesia in a manner comparable to that previously observed with morphine. These results indicate that the time-varying magnetic fields associated with MRI have significant inhibitory effects on the analgesic effects of specific mu-opiate-directed ligands.

Pre-exposure rabies prophylaxis: a systematic review

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Recuenco, Sergio; Navarro-Vela, Ana Maria; Deray, Raffy; Vigilato, Marco; Ertl, Hildegund; Durrheim, David; Rees, Helen; Nel, Louis H; Abela-Ridder, Bernadette; Briggs, Deborah

2017-01-01

Abstract Objective To review the safety and immunogenicity of pre-exposure rabies prophylaxis (including accelerated schedules, co-administration with other vaccines and booster doses), its cost–effectiveness and recommendations for use, particularly in high-risk settings. Methods We searched the PubMed, Centre for Agriculture and Biosciences International, Cochrane Library and Web of Science databases for papers on pre-exposure rabies prophylaxis published between 2007 and 29 January 2016. We reviewed field data from pre-exposure prophylaxis campaigns in Peru and the Philippines. Findings Pre-exposure rabies prophylaxis was safe and immunogenic in children and adults, also when co-administered with routine childhood vaccinations and the Japanese encephalitis vaccine. The evidence available indicates that shorter regimens and regimens involving fewer doses are safe and immunogenic and that booster intervals could be extended up to 10 years. The few studies on cost suggest that, at current vaccine and delivery costs, pre-exposure prophylaxis campaigns would not be cost-effective in most situations. Although pre-exposure prophylaxis has been advocated for high-risk populations, only Peru and the Philippines have implemented appropriate national programmes. In the future, accelerated regimens and novel vaccines could simplify delivery and increase affordability. Conclusion Pre-exposure rabies prophylaxis is safe and immunogenic and should be considered: (i) where access to postexposure prophylaxis is limited or delayed; (ii) where the risk of exposure is high and may go unrecognized; and (iii) where controlling rabies in the animal reservoir is difficult. Pre-exposure prophylaxis should not distract from canine vaccination efforts, provision of postexposure prophylaxis or education to increase rabies awareness in local communities. PMID:28250534

ATM/RB1 mutations predict shorter overall survival in urothelial cancer.

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Yin, Ming; Grivas, Petros; Emamekhoo, Hamid; Mendiratta, Prateek; Ali, Siraj; Hsu, JoAnn; Vasekar, Monali; Drabick, Joseph J; Pal, Sumanta; Joshi, Monika

2018-03-30

Mutations of DNA repair genes, e.g. ATM/RB1 , are frequently found in urothelial cancer (UC) and have been associated with better response to cisplatin-based chemotherapy. Further external validation of the prognostic value of ATM/RB1 mutations in UC can inform clinical decision making and trial designs. In the discovery dataset, ATM/RB1 mutations were present in 24% of patients and were associated with shorter OS (adjusted HR 2.67, 95% CI, 1.45-4.92, p = 0.002). There was a higher mutation load in patients carrying ATM/RB1 mutations (median mutation load: 6.7 versus 5.5 per Mb, p = 0.072). In the validation dataset, ATM/RB1 mutations were present in 22.2% of patients and were non-significantly associated with shorter OS (adjusted HR 1.87, 95% CI, 0.97-3.59, p = 0.06) and higher mutation load (median mutation load: 8.1 versus 7.2 per Mb, p = 0.126). Exome sequencing data of 130 bladder UC patients from The Cancer Genome Atlas (TCGA) dataset were analyzed as a discovery cohort to determine the prognostic value of ATM/RB1 mutations. Results were validated in an independent cohort of 81 advanced UC patients. Cox proportional hazard regression analysis was performed to calculate the hazard ratio (HR) and 95% confidence interval (CI) to compare overall survival (OS). ATM/RB1 mutations may be a biomarker of poor prognosis in unselected UC patients and may correlate with higher mutational load. Further studies are required to determine factors that can further stratify prognosis and evaluate predictive role of ATM/RB1 mutation status to immunotherapy and platinum-based chemotherapy.

Risk factors for asthma and timing of exposure among first generation Arab immigrants: a pilot effort to elucidate the role of exposure to risk factors over multiple life stages

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Considerable controversy exists over the role of aero-allergens in asthma etiology. Some studies show increased risk with microbe and allergen exposure, while others show decreased risk. These discrepancies may be explained by timing of exposure. Previous research suggests that e...

Time Perception and the Experience of Time When Immersed in an Altered Sensory Environment.

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Glicksohn, Joseph; Berkovich-Ohana, Aviva; Mauro, Federica; Ben-Soussan, Tal D

2017-01-01

The notion that exposure to a monotonous sensory environment could elicit reports indicating aberrant subjective experience and altered time perception is the impetus for the present report. Research has looked at the influence of exposure to such environments on time perception, reporting that the greater the environmental variation, the shorter is the time estimation obtained by the method of production. Most conditions for creating an altered sensory environment, however, have not facilitated an immersive experience, one that directly impacts both time perception and subjective experience. In this study, we invited our participants to enter a whole-body altered sensory environment for a 20-min session, wherein they were asked to relax without falling asleep. The session included white-colored illumination of the chamber with eyes closed (5 min), followed by 10 min of illuminating the room with color, after which a short report of subjective experience was collected using a brief questionnaire; this was followed by an additional 5 min of immersion in white light with closed eyes. The participants were then interviewed regarding their subjective experience, including their experience of time within the chamber. Prior to entering the chamber, the participants completed a time-production (TP) task. One group of participants then repeated the task within the chamber, at the end of the session; a second group of participants repeated the task after exiting the chamber. We shall report on changes in TP, and present data indicating that when produced time is plotted as a function of target duration, using a log-log plot, the major influence of sensory environment is on the intercept of the psychophysical function. We shall further present data indicating that for those participants reporting a marked change in time experience, such as "the sensation of time disappeared," their TP data could not be linearized using a log-log plot, hence indicating that for these

Time Perception and the Experience of Time When Immersed in an Altered Sensory Environment

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Joseph Glicksohn

2017-10-01

Full Text Available The notion that exposure to a monotonous sensory environment could elicit reports indicating aberrant subjective experience and altered time perception is the impetus for the present report. Research has looked at the influence of exposure to such environments on time perception, reporting that the greater the environmental variation, the shorter is the time estimation obtained by the method of production. Most conditions for creating an altered sensory environment, however, have not facilitated an immersive experience, one that directly impacts both time perception and subjective experience. In this study, we invited our participants to enter a whole-body altered sensory environment for a 20-min session, wherein they were asked to relax without falling asleep. The session included white-colored illumination of the chamber with eyes closed (5 min, followed by 10 min of illuminating the room with color, after which a short report of subjective experience was collected using a brief questionnaire; this was followed by an additional 5 min of immersion in white light with closed eyes. The participants were then interviewed regarding their subjective experience, including their experience of time within the chamber. Prior to entering the chamber, the participants completed a time-production (TP task. One group of participants then repeated the task within the chamber, at the end of the session; a second group of participants repeated the task after exiting the chamber. We shall report on changes in TP, and present data indicating that when produced time is plotted as a function of target duration, using a log–log plot, the major influence of sensory environment is on the intercept of the psychophysical function. We shall further present data indicating that for those participants reporting a marked change in time experience, such as “the sensation of time disappeared,” their TP data could not be linearized using a log–log plot, hence

Why shorter half-times of repair lead to greater damage in pulsed brachytherapy

International Nuclear Information System (INIS)

Fowler, J.F.

1993-01-01

Pulsed brachytherapy consists of replacing continuous irradiation at low dose-rate with a series of medium dose-rate fractions in the same overall time and to the same total dose. For example, pulses of 1 Gy given every 2 hr or 2 Gy given every 4 hr would deliver the same 70 Gy in 140 hr as continuous irradiation at 0.5 Gy/hr. If higher dose-rates are used, even with gaps between the pulses, the biological effects are always greater. Provided that dose rates in the pulse do not exceed 3 Gy/hr, and provided that pulses are given as often as every 2 hr, the inevitable increases of biological effect are no larger than a few percent (of biologically effective dose or extrapolated response dose). However, these increases are more likely to exceed 10% (and thus become clinically significant) if the half-time of repair of sublethal damage is short (less than 1 hr) rather than long. This somewhat unexpected finding is explained in detail here. The rise and fall of Biologically Effective Dose (and hence of Relative Effectiveness, for a constant dose in each pulse) is calculated during and after single pulses, assuming a range of values of T 1/2 , the half-time of sublethal damage repair. The area under each curve is proportional to Biologically Effective Dose and therefore to log cell kill. Pulses at 3 Gy/hr do yield greater biological effect (dose x integrated Relative Effectiveness) than lower dose-rate pulses or continuous irradiation at 0.5 Gy/hr. The contrast is greater for the short T 1/2 of 0.5 hr than for the longer T 1/2 of 1.5 hr. More biological damage will be done (compared with traditional low dose rate brachytherapy) in tissues with short T 1/2 (0.1-1 hr) than in tissues with longer T 1/2 values. 8 refs., 3 figs

Prime Time Light Exposures Do Not Seem to Improve Maximal Physical Performance in Male Elite Athletes, but Enhance End-Spurt Performance

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Arno Schmidt-Trucksäss

2017-05-01

Full Text Available Many sports competitions take place during television prime time, a time of the day when many athletes have already exceeded their time of peak performance. We assessed the effect of different light exposure modalities on physical performance and melatonin levels in athletes during prime time. Seventy-two young, male elite athletes with a median (interquartile range age of 23 (21; 29 years and maximum oxygen uptake (VO2max of 63 (58; 66 ml/kg/min were randomly assigned to three different light exposure groups: bright light (BRIGHT, blue monochromatic light (BLUE, and control light (CONTROL. Each light exposure lasted 60 min and was scheduled to start 17 h after each individual's midpoint of sleep (median time: 9:17 pm. Immediately after light exposure, a 12-min time trial was performed on a bicycle ergometer. The test supervisor and participants were blinded to the light condition each participant was exposed to. The median received light intensities and peak wavelengths (photopic lx/nm measured at eye level were 1319/545 in BRIGHT, 203/469 in BLUE, and 115/545 in CONTROL. In a multivariate analysis adjusted for individual VO2max, total work performed in 12 min did not significantly differ between the three groups. The amount of exposure to non-image forming light was positively associated with the performance gain during the time trial, defined as the ratio of the work performed in the first and last minute of the time trial, and with stronger melatonin suppression. Specifically, a tenfold increase in the exposure to melanopic light was associated with a performance gain of 8.0% (95% confidence interval: 2.6, 13.3; P = 0.004 and a melatonin decrease of −0.9 pg/ml (95% confidence interval: −1.5, −0.3; P = 0.006. Exposure to bright or blue light did not significantly improve maximum cycling performance in a 12-min all-out time trial. However, it is noteworthy that the estimated difference of 4.1 kJ between BRIGHT and CONTROL might represent

Prime Time Light Exposures Do Not Seem to Improve Maximal Physical Performance in Male Elite Athletes, but Enhance End-Spurt Performance

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Knaier, Raphael; Schäfer, Juliane; Rossmeissl, Anja; Klenk, Christopher; Hanssen, Henner; Höchsmann, Christoph; Cajochen, Christian; Schmidt-Trucksäss, Arno

2017-01-01

Many sports competitions take place during television prime time, a time of the day when many athletes have already exceeded their time of peak performance. We assessed the effect of different light exposure modalities on physical performance and melatonin levels in athletes during prime time. Seventy-two young, male elite athletes with a median (interquartile range) age of 23 (21; 29) years and maximum oxygen uptake (VO2max) of 63 (58; 66) ml/kg/min were randomly assigned to three different light exposure groups: bright light (BRIGHT), blue monochromatic light (BLUE), and control light (CONTROL). Each light exposure lasted 60 min and was scheduled to start 17 h after each individual's midpoint of sleep (median time: 9:17 pm). Immediately after light exposure, a 12-min time trial was performed on a bicycle ergometer. The test supervisor and participants were blinded to the light condition each participant was exposed to. The median received light intensities and peak wavelengths (photopic lx/nm) measured at eye level were 1319/545 in BRIGHT, 203/469 in BLUE, and 115/545 in CONTROL. In a multivariate analysis adjusted for individual VO2max, total work performed in 12 min did not significantly differ between the three groups. The amount of exposure to non-image forming light was positively associated with the performance gain during the time trial, defined as the ratio of the work performed in the first and last minute of the time trial, and with stronger melatonin suppression. Specifically, a tenfold increase in the exposure to melanopic light was associated with a performance gain of 8.0% (95% confidence interval: 2.6, 13.3; P = 0.004) and a melatonin decrease of −0.9 pg/ml (95% confidence interval: −1.5, −0.3; P = 0.006). Exposure to bright or blue light did not significantly improve maximum cycling performance in a 12-min all-out time trial. However, it is noteworthy that the estimated difference of 4.1 kJ between BRIGHT and CONTROL might represent an

The mammary gland is a sensitive pubertal target in CD-1 and C57Bl/6 mice following perinatal perfluorooctanoic acid (PFOA) exposure.

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Tucker, Deirdre K; Macon, Madisa B; Strynar, Mark J; Dagnino, Sonia; Andersen, Erik; Fenton, Suzanne E

2015-07-01

Perfluorooctanoic acid (PFOA) is a developmental toxicant in mice, with varied strain outcomes depending on dose and period of exposure. The impact of PFOA on female mouse pubertal development at low doses (≤1mg/kg) has yet to be determined. Therefore, female offspring from CD-1 and C57Bl/6 dams exposed to PFOA, creating serum concentrations similar to humans, were examined for pubertal onset, including mammary gland development. Pups demonstrated a shorter PFOA elimination half-life than that reported for adult mice. Prenatal exposure to PFOA caused significant mammary developmental delays in female offspring in both strains. Delays started during puberty and persisted into young adulthood; severity was dose-dependent. Also an evaluation of female serum hormone levels and pubertal timing onset revealed no effects of PFOA compared to controls in either strain. These data suggest that the mammary gland is more sensitive to early low level PFOA exposures compared to other pubertal endpoints, regardless of strain. Published by Elsevier Inc.

Association between Exposure to Smartphones and Ocular Health in Adolescents.

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Kim, Joowon; Hwang, Yunji; Kang, Seungheon; Kim, Minhye; Kim, Tae-Shin; Kim, Jay; Seo, Jeongmin; Ahn, Hyojeong; Yoon, Sungjoon; Yun, Jun Pil; Lee, Yae Lim; Ham, Hyunsoo; Yu, Hyeong Gon; Park, Sue K

2016-08-01

Smartphone use has dramatically increased in recent years. Smartphones may have adverse health effects, particularly on the eyes, because users stare at the screen for a much longer time than they do with ordinary mobile phones. The objective of this study was to elucidate the relationship between smartphone use and ocular symptoms among adolescents. Information on smartphone use and ocular symptoms (blurring, redness, visual disturbance, secretion, inflammation, lacrimation and dryness) related to eye fatigue and strain from 715 adolescent subjects from three cities in Korea was obtained using a structured questionnaire. Ocular health was scored using number of ocular symptoms. Odds ratios (ORs), 95% confidence intervals (95% CIs) and p-values for ocular symptoms were calculated with binomial and multinomial logistic regression models. Higher prevalence rates for ocular symptoms were observed in groups with greater exposure to smartphones (p 2 hours daily and ≤2 hours continuously) and excessive/persistent use (>2 hours daily and >2 hours continuously) compared to shorter use (<2 hours daily) were associated with multiple ocular symptoms (OR 2.18, 95% CI 1.09-4.39; OR 2.26, 95% CI 1.11-4.57, respectively). A higher lifetime exposure to smartphones was associated with a higher likelihood of having multiple ocular symptoms (OR 3.05, 95% CI 1.51-6.19; p = 0.001). Increasing exposure to smartphones can have a negative impact on ocular health in adolescents.

Exposure to radiofrequency radiation induces oxidative stress in duckweed Lemna minor L

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Tkalec, Mirta [Department of Botany, Division of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, HR-10000 Zagreb (Croatia)], E-mail: mtkalec@zg.biol.pmf.hr; Malaric, Kresimir [Faculty of Electrical Engineering and Computing, University of Zagreb, Unska 3, HR-10000 Zagreb (Croatia); Pevalek-Kozlina, Branka [Department of Botany, Division of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, HR-10000 Zagreb (Croatia)

2007-12-15

Widespread use of radiofrequency radiation emitting devices increased the exposure to electromagnetic fields (EMFs) from 300 MHz to 300 GHz. Various biological effects of exposure to these fields have been documented so far, but very little work has been carried out on plants. The aim of the present work was to investigate the physiological responses of the plant Lemna minor after exposure to radiofrequency EMFs, and in particular, to clarify the possible role of oxidative stress in the observed effects. Duckweed was exposed for 2 h to EMFs of 400 and 900 MHz at field strengths of 10, 23, 41 and 120 V m{sup -1}. The effect of a longer exposure time (4 h) and modulation was also investigated. After exposure, parameters of oxidative stress, such as lipid peroxidation, H{sub 2}O{sub 2} content, activities and isoenzyme pattern of antioxidative enzymes as well as HSP70 expression were evaluated. At 400 MHz, lipid peroxidation and H{sub 2}O{sub 2} content were significantly enhanced in duckweed exposed to EMFs of 23 and 120 V m{sup -1} while other exposure treatments did not have an effect. Compared to the controls, the activities of antioxidative enzymes showed different behaviour: catalase (CAT) activity increased after most exposure treatments while pyrogallol (PPX) and ascorbate peroxidase (APX) activities were not changed. Exceptions were reduced PPX and APX activity after longer exposure at 23 V m{sup -1} and increased PPX activity after exposures at 10 and 120 V m{sup -1}. By contrast, at 900 MHz almost all exposure treatments significantly increased level of lipid peroxidation and H{sub 2}O{sub 2} content but mostly decreased PPX activity and did not affect CAT activity. Exceptions were exposures to a modulated field and to the field of 120 V m{sup -1} which increased PPX and CAT activity. At this frequency APX activity was significantly decreased after exposure at 10 V m{sup -1} and longer exposure at 23 V m{sup -1} but it increased after a shorter exposure at

Exposure to radiofrequency radiation induces oxidative stress in duckweed Lemna minor L

International Nuclear Information System (INIS)

Tkalec, Mirta; Malaric, Kresimir; Pevalek-Kozlina, Branka

2007-01-01

Widespread use of radiofrequency radiation emitting devices increased the exposure to electromagnetic fields (EMFs) from 300 MHz to 300 GHz. Various biological effects of exposure to these fields have been documented so far, but very little work has been carried out on plants. The aim of the present work was to investigate the physiological responses of the plant Lemna minor after exposure to radiofrequency EMFs, and in particular, to clarify the possible role of oxidative stress in the observed effects. Duckweed was exposed for 2 h to EMFs of 400 and 900 MHz at field strengths of 10, 23, 41 and 120 V m -1 . The effect of a longer exposure time (4 h) and modulation was also investigated. After exposure, parameters of oxidative stress, such as lipid peroxidation, H 2 O 2 content, activities and isoenzyme pattern of antioxidative enzymes as well as HSP70 expression were evaluated. At 400 MHz, lipid peroxidation and H 2 O 2 content were significantly enhanced in duckweed exposed to EMFs of 23 and 120 V m -1 while other exposure treatments did not have an effect. Compared to the controls, the activities of antioxidative enzymes showed different behaviour: catalase (CAT) activity increased after most exposure treatments while pyrogallol (PPX) and ascorbate peroxidase (APX) activities were not changed. Exceptions were reduced PPX and APX activity after longer exposure at 23 V m -1 and increased PPX activity after exposures at 10 and 120 V m -1 . By contrast, at 900 MHz almost all exposure treatments significantly increased level of lipid peroxidation and H 2 O 2 content but mostly decreased PPX activity and did not affect CAT activity. Exceptions were exposures to a modulated field and to the field of 120 V m -1 which increased PPX and CAT activity. At this frequency APX activity was significantly decreased after exposure at 10 V m -1 and longer exposure at 23 V m -1 but it increased after a shorter exposure at 23 V m -1 . At both frequencies no differences in isoenzyme

Moderate Exercise Allows for shorter Recovery Time in Critical Limb Ischemia

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Anne Lejay

2017-07-01

Full Text Available Whether and how moderate exercise might allow for accelerated limb recovery in chronic critical limb ischemia (CLI remains to be determined. Chronic CLI was surgically induced in mice, and the effect of moderate exercise (training five times per week over a 3-week period was investigated. Tissue damages and functional scores were assessed on the 4th, 6th, 10th, 20th, and 30th day after surgery. Mice were sacrificed 48 h after the last exercise session in order to assess muscle structure, mitochondrial respiration, calcium retention capacity, oxidative stress and transcript levels of genes encoding proteins controlling mitochondrial functions (PGC1α, PGC1β, NRF1 and anti-oxidant defenses markers (SOD1, SOD2, catalase. CLI resulted in tissue damages and impaired functional scores. Mitochondrial respiration and calcium retention capacity were decreased in the ischemic limb of the non-exercised group (Vmax = 7.11 ± 1.14 vs. 9.86 ± 0.86 mmol 02/min/g dw, p < 0.001; CRC = 7.01 ± 0.97 vs. 11.96 ± 0.92 microM/mg dw, p < 0.001, respectively. Moderate exercise reduced tissue damages, improved functional scores, and restored mitochondrial respiration and calcium retention capacity in the ischemic limb (Vmax = 9.75 ± 1.00 vs. 9.82 ± 0.68 mmol 02/min/g dw; CRC = 11.36 ± 1.33 vs. 12.01 ± 1.24 microM/mg dw, respectively. Exercise also enhanced the transcript levels of PGC1α, PGC1β, NRF1, as well as SOD1, SOD2, and catalase. Moderate exercise restores mitochondrial respiration and calcium retention capacity, and it has beneficial functional effects in chronic CLI, likely by stimulating reactive oxygen species-induced biogenesis and anti-oxidant defenses. These data support further development of exercise therapy even in advanced peripheral arterial disease.

Radiation exposure in nuclear medicine: real-time measurement

International Nuclear Information System (INIS)

Sylvain, Iara; Bok, Bernard; X. Bichat University, Paris

2002-01-01

French regulations have introduced the use of electronic dosimeters for personnel monitoring of workers. In order to evaluate the exposure from diagnostic procedures to nuclear medicine staff, individual whole-body doses were measured daily with electronic (digital) personal dosimeters during 20 consecutive weeks and correlated with the work load of each day. Personal doses remained always below 20 mu Sv/d under normal working conditions. Radiation exposure levels were highest to tech staff, nurses and stretcher-bearers. The extrapolated annual cumulative doses for all staff remained less than 10% of the maximum legal limit for exposed workers (2 mSv/yr). Electronic dosimeters are not technically justified for routine survey of staff. The high sensitivity and immediate reading of electronic semiconductor dosimeters may become very useful for exposure control under risky working conditions. It may become an important help for optimising radiation protection. (author)

A Bayesian Approach for Summarizing and Modeling Time-Series Exposure Data with Left Censoring.

Science.gov (United States)

Houseman, E Andres; Virji, M Abbas

2017-08-01

Direct reading instruments are valuable tools for measuring exposure as they provide real-time measurements for rapid decision making. However, their use is limited to general survey applications in part due to issues related to their performance. Moreover, statistical analysis of real-time data is complicated by autocorrelation among successive measurements, non-stationary time series, and the presence of left-censoring due to limit-of-detection (LOD). A Bayesian framework is proposed that accounts for non-stationary autocorrelation and LOD issues in exposure time-series data in order to model workplace factors that affect exposure and estimate summary statistics for tasks or other covariates of interest. A spline-based approach is used to model non-stationary autocorrelation with relatively few assumptions about autocorrelation structure. Left-censoring is addressed by integrating over the left tail of the distribution. The model is fit using Markov-Chain Monte Carlo within a Bayesian paradigm. The method can flexibly account for hierarchical relationships, random effects and fixed effects of covariates. The method is implemented using the rjags package in R, and is illustrated by applying it to real-time exposure data. Estimates for task means and covariates from the Bayesian model are compared to those from conventional frequentist models including linear regression, mixed-effects, and time-series models with different autocorrelation structures. Simulations studies are also conducted to evaluate method performance. Simulation studies with percent of measurements below the LOD ranging from 0 to 50% showed lowest root mean squared errors for task means and the least biased standard deviations from the Bayesian model compared to the frequentist models across all levels of LOD. In the application, task means from the Bayesian model were similar to means from the frequentist models, while the standard deviations were different. Parameter estimates for covariates

N-Terminal Domains in Two-Domain Proteins Are Biased to Be Shorter and Predicted to Fold Faster Than Their C-Terminal Counterparts

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Etai Jacob

2013-04-01

Full Text Available Computational analysis of proteomes in all kingdoms of life reveals a strong tendency for N-terminal domains in two-domain proteins to have shorter sequences than their neighboring C-terminal domains. Given that folding rates are affected by chain length, we asked whether the tendency for N-terminal domains to be shorter than their neighboring C-terminal domains reflects selection for faster-folding N-terminal domains. Calculations of absolute contact order, another predictor of folding rate, provide additional evidence that N-terminal domains tend to fold faster than their neighboring C-terminal domains. A possible explanation for this bias, which is more pronounced in prokaryotes than in eukaryotes, is that faster folding of N-terminal domains reduces the risk for protein aggregation during folding by preventing formation of nonnative interdomain interactions. This explanation is supported by our finding that two-domain proteins with a shorter N-terminal domain are much more abundant than those with a shorter C-terminal domain.

Transient anhedonia phenotype and altered circadian timing of behaviour during night-time dim light exposure in Per3−/− mice, but not wildtype mice

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Martynhak, Bruno Jacson; Hogben, Alexandra L.; Zanos, Panos; Georgiou, Polymnia; Andreatini, Roberto; Kitchen, Ian; Archer, Simon N.; von Schantz, Malcolm; Bailey, Alexis; van der Veen, Daan R.

2017-01-01

Industrialisation greatly increased human night-time exposure to artificial light, which in animal models is a known cause of depressive phenotypes. Whilst many of these phenotypes are ‘direct’ effects of light on affect, an ‘indirect’ pathway via altered sleep-wake timing has been suggested. We have previously shown that the Period3 gene, which forms part of the biological clock, is associated with altered sleep-wake patterns in response to light. Here, we show that both wild-type and Per3−/− mice showed elevated levels of circulating corticosterone and increased hippocampal Bdnf expression after 3 weeks of exposure to dim light at night, but only mice deficient for the PERIOD3 protein (Per3−/−) exhibited a transient anhedonia-like phenotype, observed as reduced sucrose preference, in weeks 2–3 of dim light at night, whereas WT mice did not. Per3−/− mice also exhibited a significantly smaller delay in behavioural timing than WT mice during weeks 1, 2 and 4 of dim light at night exposure. When treated with imipramine, neither Per3−/− nor WT mice exhibited an anhedonia-like phenotype, and neither genotypes exhibited a delay in behavioural timing in responses to dLAN. While the association between both Per3−/− phenotypes remains unclear, both are alleviated by imipramine treatment during dim night-time light. PMID:28071711

Impacts of ocean acidification on sperm develop with exposure time for a polychaete with long lived sperm.

Science.gov (United States)

Campbell, Anna L; Ellis, Robert P; Urbina, Mauricio A; Mourabit, Sulayman; Galloway, Tamara S; Lewis, Ceri

2017-08-01

The majority of marine invertebrate species release eggs and sperm into seawater for external fertilisation. Seawater conditions are currently changing at an unprecedented rate as a consequence of ocean acidification (OA). Sperm are thought to be particularly vulnerable to these changes and may be exposed to external environmental conditions for variable periods of time between spawning and fertilisation. Here, we undertook a mechanistic investigation of sperm swimming performance in the coastal polychaete Arenicola marina during an extended exposure to OA conditions (pH NBS 7.77, 1000 μatm pCO 2 ). We found that key fitness-related aspects of sperm functioning declined faster under OA conditions i.e. impacts became apparent with exposure time. Sperm swimming speed (VCL), the number of motile sperm and sperm path linearity all dropped significantly after 4 h under OA conditions whilst remaining constant under ambient conditions at this time point. Our results highlight the importance of sperm exposure duration in ocean acidification experiments and may help towards explaining species specific differences in response. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluating the Impact of Antibiotic Exposures as Time-Dependent Variables on the Acquisition of Carbapenem-Resistant Acinetobacter baumannii.

Science.gov (United States)

Munoz-Price, L Silvia; Rosa, Rossana; Castro, Jose G; Laowansiri, Panthipa; Latibeaudiere, Rachel; Namias, Nicholas; Tarima, Sergey

2016-10-01

To determine the time-dependent effect of antibiotics on the initial acquisition of carbapenem-resistant Acinetobacter baumannii. Retrospective cohort study. Forty-bed trauma ICU in Miami, FL. All consecutive patients admitted to the unit from November 1, 2010, to November 30, 2011. None. Patients underwent surveillance cultures at admission to the unit and weekly thereafter. The primary outcome was the acquisition of carbapenem-resistant A. baumannii on surveillance cultures. Daily antibiotic exposures during the time of observation were used to construct time-dependent variables, including cumulative exposures (in grams and daily observed doses [defined daily doses]). Among 360 patients, 45 (12.5%) became colonized with carbapenem-resistant A. baumannii. Adjusted Cox models showed that each additional point in the Acute Physiologic and Chronic Health Evaluation score increased the hazard by 4.8% (hazard ratio, 1.048; 95% CI, 1.010-1.087; p = 0.0124) and time-dependent exposure to carbapenems quadrupled the hazard (hazard ratio, 4.087; 95% CI, 1.873-8.920; p = 0.0004) of acquiring carbapenem-resistant A. baumannii. Additionally, adjusted Cox models determined that every additional carbapenem defined daily dose increased the hazard of acquiring carbapenem-resistant A. baumannii by 5.1% (hazard ratio, 1.051; 95% CI, 1.007-1.093; p = 0.0243). Carbapenem exposure quadrupled the hazards of acquiring A. baumannii even after controlling for severity of illness.

Studying DDT Susceptibility at Discriminating Time Intervals Focusing on Maximum Limit of Exposure Time Survived by DDT Resistant Phlebotomus argentipes (Diptera: Psychodidae): an Investigative Report.

Science.gov (United States)

Rama, Aarti; Kesari, Shreekant; Das, Pradeep; Kumar, Vijay

2017-07-24

Extensive application of routine insecticide i.e., dichlorodiphenyltrichloroethane (DDT) to control Phlebotomus argentipes (Diptera: Psychodidae), the proven vector of visceral leishmaniasis in India, had evoked the problem of resistance/tolerance against DDT, eventually nullifying the DDT dependent strategies to control this vector. Because tolerating an hour-long exposure to DDT is not challenging enough for the resistant P. argentipes, estimating susceptibility by exposing sand flies to insecticide for just an hour becomes a trivial and futile task.Therefore, this bioassay study was carried out to investigate the maximum limit of exposure time to which DDT resistant P. argentipes can endure the effect of DDT for their survival. The mortality rate of laboratory-reared DDT resistant strain P. argentipes exposed to DDT was studied at discriminating time intervals of 60 min and it was concluded that highly resistant sand flies could withstand up to 420 min of exposure to this insecticide. Additionally, the lethal time for female P. argentipes was observed to be higher than for males suggesting that they are highly resistant to DDT's toxicity. Our results support the monitoring of tolerance limit with respect to time and hence points towards an urgent need to change the World Health Organization's protocol for susceptibility identification in resistant P. argentipes.

Experimental study of some homeostatic parameters at late times after exposure to radiation

International Nuclear Information System (INIS)

Chertkov, K.S.; Andrianova, I.E.; Atamanova, O.M.; Filimonova, G.I.; Nesterova, T.A.; Sbitneva, M.F.; Glushkov, V.A.; Chotij, V.G.; Stejmatskaya, Z.A.

1994-01-01

Following radiation damage from LD 50 - LD 97 , changes in blood, immune and endocrine parameters were revealed and followed up in dogs at the time of late effects development, 3-18 months after exposure. The changes result from post-radiation immunodeficiency and resemble those observed in residents of radioactive contaminate areas or in men participated in Chernobyl accident amelioration

Implications of sequence and timing of exposure for synergy between the pyrethroid insecticide alpha-cypermethrin and the entomopathogenic fungus Beauveria bassiana.

Science.gov (United States)

Meyling, Nicolai V; Arthur, Samuel; Pedersen, Kathrine E; Dhakal, Suraj; Cedergreen, Nina; Fredensborg, Brian L

2018-03-30

Combining low doses of chemical insecticides with entomopathogens constitutes a sustainable pest control method, but the significance of the timing and sequence of exposures needs clarification. We studied lethal effects of combinations of the entomopathogenic fungus Beauveria bassiana (KVL03-122) and the pyrethroid alpha-cypermethrin on the beetle Tenebrio molitor under varying timing and sequence of exposure. Synergy over time was evaluated in relation to the model of independent action (IA). We expected that increased progression of disease caused by B. bassiana would make beetles more susceptible to the insecticide, leading to enhanced synergy. Synergistic effects between B. bassiana and alpha-cypermethrin were observed when B. bassiana was applied first, but only when the interval between applications was >48 h. With 72 h between exposures, mortality had increased to 100% after 8 days, in contrast to the 60% mortality expected. No synergy was observed when the insecticide was applied prior to fungal exposure within 24 h. The sequence and timing of exposure do matter to achieve synergistic mortality by combining B. bassiana and alpha-cypermethrin, and the IA model proved to be a strong tool with which to evaluate the interactions of the two stressors over time. Pest control strategies could include B. bassiana followed by low-dose exposures to alpha-cypermethrin after 2-3 days. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Effect of Exposure Type and Timing of Injuries in Division I College Football: A 4-year Single Program Analysis.

Science.gov (United States)

Krill, Michael K; Borchers, James R; Hoffman, Joshua T; Tatarski, Rachel L; Hewett, Timothy E

2017-02-01

Football players compete with a high risk of injury due to the sport. With the recent efforts to improve safety, the National Collegiate Athletic Association (NCAA) established new terminology to clearly define exposure types and reduce the number of high contact exposures. To compare football injury rates (IR) with a focus on game versus practice, time in season of injury, mechanism of injury and utilizing recent exposure types defined by the NCAA (live contact, full-pads and non-contact). Licensed medical professionals monitored a college football program regular season from 2012-2015. Each injury was classified by timing of the injury, mechanism of injury, and whether it occurred in game or practice. Player attendance and type of exposure (non-contact, full-pad or live contact, which involves live tackling to the ground and/or full-speed blocking and can occur in full-pad or half-pad ('shell') equipment) was documented. IR were calculated per 1000 athlete-exposures (AE). Mid-exact P tests compared rates between variables. The game IR was over three times as high as the practice IR (p football season occurred in the pre-season at 5.769/1000 AE. Overall IR observed in this cohort were lower than prior studies published before recent NCAA rule changes and guideline implementation to improve athlete safety. Athletes in this cohort were at significantly increased risk of injury from live contact exposures.

Device for measuring the exposure time in dental X-ray - Cronox

International Nuclear Information System (INIS)

Menezes, Claudio J.M.; Santos, Luiz A.P. dos

2009-01-01

The Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE) developed a test device for monitoring the X-ray beam in dental equipment to its application in quality control programs. This device, called Odontologic Dosimetric Card (CDO of Cartao Dosimetrico Odontologico in Portuguese) uses thermoluminescent dosimeters (TLD) for the measurement of some parameters of the X-ray beam as the entrance surface dose, the peak tension and half value layer (HVL). Radiographic films record the size of the radiation field. However, the TLD does not allow the assessment of exposure time, a parameter that complements the requirements of the Diretrizes de Protecao Radiologica em Radiodiagnostico Medico e Odontologico of Department of Health in Brazil for such equipment. Thus was developed a system based on sensitivity to ionizing radiation of phototransistors for measurement of exposure time when a patient is put in a clinical dental radiography. The system, called CRONOX was sized to be inserted within the CDO. The results showed that the measuring error had developed for less than 3% when compared to reference values obtained with the Tektronix digital oscilloscope, TDS2022 model. The readings obtained with the CRONOX were also compared with the nominal values selected in the X-ray equipment and with the values measured with the instrument of trade PTW Diavolt Universal. The results showed that the measuring device developed showed a maximum deviation of 5.92% on the nominal value selected, while for the instrument of PTW was 17.86%. (author)

Shorter duration of breastfeeding at elevated exposures to perfluoroalkyl substances

DEFF Research Database (Denmark)

Timmermann, Clara Amalie Gade; Budtz-Jørgensen, Esben; Petersen, Maria Skaalum

2017-01-01

. Duration of breastfeeding was assessed by questionnaire and clinical interview. In adjusted linear regression models, a doubling of maternal serum PFASs was associated with a reduction in duration of both total and exclusive breastfeeding, most pronounced for perfluorooctane sulfonic acid (PFOS) where...... a doubling was associated with a reduction in total breastfeeding of 1.4 (95% CI: 0.6; 2.1) months and perfluorooctanoic acid (PFOA) where a doubling was associated with a reduction in exclusive breastfeeding of 0.5 (0.3; 0.7) months. The associations were evident among both primiparous and multiparous women......, and thus cannot be explained by confounding from previous breastfeeding....

Growth and ion accumulation in dwarf cashew plants at different times of salinity exposure

Directory of Open Access Journals (Sweden)

Valdineia Soares Freitas

2013-12-01

Full Text Available This work aimed to evaluate the influence of salt stress exposition on growth and ion accumulation in dwarf cashew plants. For this purpose, cashew nuts (CCP 06 clone were sown in plastic trays containing vermiculite moistened with nutrient solution containing NaCl with electrical conductivities ranging from 0.0 to 18.0 dS m-1. Plants were harvested after 30 and 60 days under salt stress. It was determined the shoot dry masses (SDM and root (RDM, the SDM/RDM ratio, Na+, K+, Cl- and NO3 - contents and the Na+ and Cl- fluxes for whole plant in the period between two times of exposure to salt stress. The cashew growth was affected by salinity and by the exposure time to this stress, and the plants subjected to 60 days of stress were the most affected by NaCl. The Na+ and Cl- contents increased in all plant tissues, while the NO3 - content was reduced and K+ content has not changed by salinity. The Na+ and Cl-fluxes increased with salinity; however Cl- seemed to be more harmful to plants, since this ion has been absorbed in a higher ratio than Na+. The growth reduction in dwarf cashew is intensified when exposure to salt stress is longer and it is more associated with uptake and excessive accumulation of Cl- than Na+.

Time-dependent inhibition of Na+/K+-ATPase induced by single and simultaneous exposure to lead and cadmium

Science.gov (United States)

Vasić, V.; Kojić, D.; Krinulović, K.; Čolović, M.; Vujačić, A.; Stojić, D.

2007-09-01

Time-dependent interactions of Na+/K+-ATPase, isolated from rat brain synaptic plasma membranes (SPMs), with Cd2+ and Pb2+ ions in a single exposure and in a mixture were investigated in vitro. The interference of the enzyme with these metal ions was studied as a function of different protein concentrations and exposure time. The aim of the work was to investigate the possibility of selective recognition of Cd2+ and Pb2+ ions in a mixture, on the basis of the different rates of their protein-ligand interactions. Decreasing protein concentration increased the sensitivity of Na+/K+-ATPase toward both metals. The selectivity in protein-ligand interactions was obtained by variation of preincubation time (incubation before starting the enzymatic reaction).

Lysis of Chlamydomonas reinhardtii by high-intensity focused ultrasound as a function of exposure time.

Science.gov (United States)

Bigelow, Timothy A; Xu, Jin; Stessman, Dan J; Yao, Linxing; Spalding, Martin H; Wang, Tong

2014-05-01

Efficient lysis of microalgae for lipid extraction is an important concern when processing biofuels. Historically, ultrasound frequencies in the range of 10-40 kHz have been utilized for this task. However, greater efficiencies might be achievable if higher frequencies could be used. In our study, we evaluated the potential of using 1.1 MHz ultrasound to lyse microalgae for biofuel production while using Chlamydomonas reinhardtii as a model organism. The ultrasound was generated using a spherically focused transducer with a focal length of 6.34 cm and an active diameter of 6.36 cm driven by 20 cycle sine-wave tone bursts at a pulse repetition frequency of 2 kHz (3.6% duty cycle). The time-average acoustic power output was 26.2 W while the spatial-peak-pulse-average intensity (ISPPA) for each tone burst was 41 kW/cm(2). The peak compressional and rarefactional pressures at the focus were 102 and 17 MPa, respectively. The exposure time was varied for the different cases in the experiments from 5s to 9 min and cell lysis was assessed by quantifying the percentage of protein and chlorophyll release into the supernate as well as the lipid extractability. Free radical generation and lipid oxidation for the different ultrasound exposures were also determined. We found that there was a statistically significant increase in lipid extractability for all of the exposures compared to the control. The longer exposures also completely fragmented the cells releasing almost all of the protein and chlorophyll into the supernate. The cavitation activity did not significantly increase lipid oxidation while there was a minor trend of increased free radical production with increased ultrasound exposure. Copyright © 2013 Elsevier B.V. All rights reserved.

Timing and Duration of Drug Exposure Affects Outcomes of a Drug-Nutrient Interaction During Ontogeny

Directory of Open Access Journals (Sweden)

Jane Alcorn

2010-10-01

Full Text Available Significant drug-nutrient interactions are possible when drugs and nutrients share the same absorption and disposition mechanisms. During postnatal development, the outcomes of drug-nutrient interactions may change with postnatal age since these processes undergo ontogenesis through the postnatal period. Our study investigated the dependence of a significant drug-nutrient interaction (cefepime-carnitine on the timing and duration of drug exposure relative to postnatal age. Rat pups were administered cefepime (5 mg/kg twice daily subcutaneously according to different dosing schedules (postnatal day 1-4, 1-8, 8-11, 8-20, or 1-20. Cefepime significantly reduced serum and heart L-carnitine levels in postnatal day 1-4, 1-8 and 8-11 groups and caused severe degenerative changes in ventricular myocardium in these groups. Cefepime also altered the ontogeny of several key L-carnitine homeostasis pathways. The qualitative and quantitative changes in levels of hepatic γ-butyrobetaine hydroxylase mRNA and activity, hepatic trimethyllysine hydroxlase mRNA, intestinal organic cation/carnitine transporter (Octn mRNA, and renal Octn2 mRNA depended on when during postnatal development the cefepime exposure occurred and duration of exposure. Despite lower levels of heart L-carnitine in earlier postnatal groups, levels of carnitine palmitoyltransferase mRNA and activity, heart Octn2 mRNA and ATP levels in all treatment groups remained unchanged with cefepime exposure. However, changes in other high energy phosphate substrates were noted and reductions in the phosphocreatine/ATP ratio were found in rat pups with normal serum L-carnitine levels. In summary, our data suggest a significant drug-nutrient transport interaction in developing neonates, the nature of which depends on the timing and duration of exposure relative to postnatal age.

Exposure to PFOS, PFHxS, or PFHxA, but not GenX, Nafion BP1, or ADONA, Elicits Developmental Neurotoxicity in Larval Zebrafish

Science.gov (United States)

Exposure to polyfluoroalkyl substances (PFAS) like perfluorooctane sulfonic acid (PFOS) or perfluorooctanoic acid (PFOA) are associated with developmental toxicity, neurotoxicity, and carcinogenesis. Legacy PFAS have therefore been replaced with shorter carbon chain and polyfluor...

Effect of ambient light on the time needed to complete a fetal biophysical profile: A randomized controlled trial.

Science.gov (United States)

Said, Heather M; Gupta, Shweta; Vricella, Laura K; Wand, Katy; Nguyen, Thinh; Gross, Gilad

2017-10-01

The objective of this study is to determine whether ambient light serves as a fetal stimulus to decrease the amount of time needed to complete a biophysical profile. This is a randomized controlled trial of singleton gestations undergoing a biophysical profile. Patients were randomized to either ambient light or a darkened room. The primary outcome was the time needed to complete the biophysical profile. Secondary outcomes included total and individual component biophysical profile scores and scores less than 8. A subgroup analysis of different maternal body mass indices was also performed. 357 biophysical profile studies were analyzed. 182 studies were performed with ambient light and 175 were performed in a darkened room. There was no difference in the median time needed to complete the biophysical profile based on exposure to ambient light (6.1min in darkened room versus 6.6min with ambient light; P=0.73). No difference was found in total or individual component biophysical profile scores. Subgroup analysis by maternal body mass index did not demonstrate shorter study times with ambient light exposure in women who were normal weight, overweight or obese. Ambient light exposure did not decrease the time needed to complete the biophysical profile. There was no evidence that ambient light altered fetal behavior observed during the biophysical profile. Copyright © 2017 Elsevier B.V. All rights reserved.

Pre-hospital electrocardiogram triage with tele-cardiology support is associated with shorter time-to-balloon and higher rates of timely reperfusion even in rural areas: data from the Bari- Barletta/Andria/Trani public emergency medical service 118 registry on primary angioplasty in ST-elevation myocardial infarction.

Science.gov (United States)

Brunetti, Natale Daniele; Di Pietro, Gaetano; Aquilino, Ambrogio; Bruno, Angela I; Dellegrottaglie, Giulia; Di Giuseppe, Giuseppe; Lopriore, Claudio; De Gennaro, Luisa; Lanzone, Saverio; Caldarola, Pasquale; Antonelli, Gianfranco; Di Biase, Matteo

2014-09-01

We report the preliminary data from a regional registry on ST-elevation myocardial infarction (STEMI) patients treated with primary angioplasty in Apulia, Italy; the region is covered by a single public health-care service, a single public emergency medical service (EMS), and a single tele-medicine service provider. Two hundred and ninety-seven consecutive patients with STEMI transferred by regional free public EMS 1-1-8 for primary-PCI were enrolled in the study; 123 underwent pre-hospital electrocardiograms (ECGs) triage by tele-cardiology support and directly referred for primary-PCI, those remaining were just transferred by 1-1-8 ambulances for primary percutaneous coronary intervention (PCI) (diagnosis not based on tele-medicine ECG; already hospitalised patients, emergency-room without tele-medicine support). Time from first ECG diagnostic for STEMI to balloon was recorded; a time-to-balloon primary-PCI). Pre-hospital triage with tele-cardiology ECG in an EMS registry from an area with more than one and a half million inhabitants was associated with shorter time-to-balloon and higher rates of timely treated patients, even in 'rural' areas. © The European Society of Cardiology 2014.

Applicability of the shorter ‘Bangladesh regimen’ in high multidrug-resistant tuberculosis settings

Directory of Open Access Journals (Sweden)

Giovanni Sotgiu

2017-03-01

Full Text Available In spite of the recent introduction of two new drugs (delamanid and bedaquiline and a few repurposed compounds to treat multidrug-resistant and extensively drug-resistant tuberculosis (MDR- and XDR-TB, clinicians are facing increasing problems in designing effective regimens in severe cases. Recently a 9 to 12-month regimen (known as the ‘Bangladesh regimen’ proved to be effective in treating MDR-TB cases. It included an initial phase of 4 to 6 months of kanamycin, moxifloxacin, prothionamide, clofazimine, pyrazinamide, high-dose isoniazid, and ethambutol, followed by 5 months of moxifloxacin, clofazimine, pyrazinamide, and ethambutol. However, recent evidence from Europe and Latin America identified prevalences of resistance to the first-line drugs in this regimen (ethambutol and pyrazinamide exceeding 60%, and of prothionamide exceeding 50%. Furthermore, the proportions of resistance to the two most important pillars of the regimen – quinolones and kanamycin – were higher than 40%. Overall, only 14 out of 348 adult patients (4.0% were susceptible to all of the drugs composing the regimen, and were therefore potentially suitable for the ‘shorter regimen’. A shorter, cheaper, and well-tolerated MDR-TB regimen is likely to impact the number of patients treated and improve adherence if prescribed to the right patients through the systematic use of rapid MTBDRsl testing.

Accelerated stress testing in a time-driven product development process

NARCIS (Netherlands)

Lu, Y.; Loh, H.T.; Brombacher, A.C.; Ouden, den P.H.

2000-01-01

In order to compete in the market, companies have to produce the right products with a shorter time to market and at lower costs than before. Shorter time to market requires the product development process (PDP) to change the way of working from the classical ‘wait and react’ to anticipating and

The association between post-traumatic stress disorder and shorter telomere length: A systematic review and meta-analysis.

Science.gov (United States)

Li, Xuemei; Wang, Jiang; Zhou, Jianghua; Huang, Pan; Li, Jiping

2017-08-15

Post-traumatic stress disorder (PTSD) is a common psychiatric disorder, which may accelerate aging. Many study have investigated the association between telomeres length and PTSD, but results from published studies are contradictory. Therefore, Meta-analysis approaches were conducted to give more precise estimate of relationship between telomere length and PTSD. We systematically reviewed the databases of PUBMED, PsycINFO, Medline(Ovid SP) and EMBASE for all articles on the association between telomere length and PTSD. Data were summarized by using random-effects in the meta-analysis. The heterogeneity among studies were examined by using Cochrane's Q statistic and I-squared. Five eligible studies containing 3851 participants were included in our meta-analysis. Shorten telomere length was significantly associated with PTSD with mean difference of -0.19( 95% CI: -0.27, -0.01; P<0.001) with I-square of 96%. The results from subgroup analysis demonstrated that shorter telomere length was significantly associated with PTSD across all gender groups, with mean difference of -0.15( 95% CI: -0.29, -0.01; P=0.04) for female, mean difference of -0.17( 95% CI: -0.19, -0.15; P<0.001) for male. Meanwhile, shorten telomere length was significantly associated with sexual assault(mean difference =-0.15, 95% CI: -0.29, -0.01), childhood trauma (mean difference =-0.08, 95% CI: -0.19, -0.07), but not combat (mean difference =-0.39, 95% CI: -0.83, 0.05). Compared to the individuals without PTSD, individuals with PTSD have shorter telomere length, which has implications for early intervention and timely treatment to prevent future adverse health outcomes. Copyright © 2017. Published by Elsevier B.V.

Color Stability of Enamel following Different Acid Etching and Color Exposure Times

Directory of Open Access Journals (Sweden)

Arezoo Jahanbin

2014-06-01

Full Text Available Background and aims. The aim of this study was to evaluate the effect of different etching times on enamel color stability after immediate versus delayed exposure to colored artificial saliva (CAS. Materials and methods. Human first premolars were divided into five groups of twenty. A colorimeter was used according to the CIE system on the mid-buccal and mid-lingual surfaces to evaluate initial tooth color. Samples in group A remained unetched. In groups B to E, buccal and lingual surfaces were initially etched with phosphoric acid for 15 and 60 seconds, respectively. Then, the samples in groups A and C were immersed in colored artificial saliva (cola+saliva. In group B, the teeth were immersed in simple artificial saliva (AS. Samples in groups D and E were immersed in AS for 24 and 72 hours, respectively before being immersed in colored AS. The teeth were immersed for one month in each solution before color measurement. During the test period, the teeth were retrieved from the staining solution and stored in AS for five minutes. This was repeated 60 times. Color changes of buccal and lingual surfaces were calculated. Kruskal-Wallis and Wilcoxon tests were used for statistical analysis (α ≤ 0.05. Results. There were no significant differences between the groups in term of ΔE of buccal (P = 0.148 and lingual surfaces (P = 0.73. Conclusion. Extended time of etching did not result in significant enamel color change. Immediate and delayed exposure of etched enamel to staining solutions did not result in clinically detectable tooth color changes.

Development of three-dimensional shoulder kinematic and electromyographic exposure variation analysis methodology in violin musicians.

Science.gov (United States)

Reynolds, Jonathan F; Leduc, Robert E; Kahnert, Emily K; Ludewig, Paula M

2014-01-01

A total of 11 male and 19 female violinists performed 30-second random-ordered slow and fast musical repertoire while right shoulder three-dimensional kinematic, and upper trapezius and serratus anterior surface electromyography (EMG) data were summarised using exposure variation analysis (EVA), a bivariate distribution of work time spent at categories of signal amplitude, and duration spent at a fixed category of amplitude. Sixty-two per cent of intraclass correlation coefficients [1,1] for all kinematic and EMG variables exceeded 0.75, and 40% of standard error of the measurement results were below 5%, confirming EVA reliability. When fast repertoire was played, increases in odds ratios in short duration cells were seen in 23 of 24 possible instances, and decreases in longer duration cells were seen in 17 instances in all EVA arrays using multinomial logistic regression with random effects, confirming a shift towards shorter duration. A reliable technique to assess right shoulder kinematic and EMG exposure in violinists was identified. A reliable method of measuring right shoulder motion and muscle activity exposure variation in violinists was developed which can be used to assess ergonomic risk in other occupations. Recently developed statistical methods enabled differentiation between fast and slow musical performance of standardised musical repertoire.

Leisure time activities related to carcinogen exposure and lung cancer risk in never smokers. A case-control study

International Nuclear Information System (INIS)

Ruano-Ravina, Alberto; García-Lavandeira, José Antonio; Torres-Durán, María; Prini-Guadalupe, Luciana; Parente-Lamelas, Isaura; Leiro-Fernández, Virginia; Montero-Martínez, Carmen; González-Barcala, Francisco Javier; Golpe-Gómez, Antonio; Martínez, Cristina; Castro-Añón, Olalla; Mejuto-Martí, María José

2014-01-01

We aim to assess the relationship between leisure time activities related to exposure to carcinogenic substances and lung cancer risk in a hospital-based case-control study performed in never smokers. We included never smoking cases with anatomopathologically confirmed lung cancer and never smoking controls undergoing trivial surgery, at 8 Spanish hospitals. The study was conducted between January 2011 and June 2013. Participants were older than 30 and had no previous neoplasms. All were personally interviewed focusing on lifestyle, environmental tobacco smoke exposure, occupational history and leisure time activities (including duration of such activities). Results were analyzed through logistic regression and adjusted also by residential radon and education level. We included 513 never smokers, 191 cases and 322 controls. The OR for those performing the studied leisure time activities was 1.43 (95%CI 0.78–2.61). When we restricted the analysis to those performing do-it-yourself activities for more than 10 years the OR was 2.21 (95%CI 0.93–5.27). Environmental tobacco smoke exposure did not modify this association. The effect for the different lung cancer histological types was very close to significance for adenocarcinoma but only when these activities were performed for more than 10 years. We encourage health professionals to recommend protective measures for those individuals while performing these hobbies to reduce the risk of lung cancer. - Highlights: • Some leisure time activities are associated with the exposure to carcinogenic substances. • These activities are model-making, painting (artistic or not), furniture refinishing or wood working. • Few studies have assessed lung cancer risk due to these hobbies and none in never-smokers. • Leisure activities related to exposure to carcinogenic substances present higher lung cancer risk. • The risk is higher when these activities are performed for more than 10 years

Leisure time activities related to carcinogen exposure and lung cancer risk in never smokers. A case-control study

Energy Technology Data Exchange (ETDEWEB)

Ruano-Ravina, Alberto, E-mail: alberto.ruano@usc.es [Department of Preventive Medicine and Public Health, University of Santiago de Compostela, Santiago de Compostela (Spain); CIBER de Epidemiología y Salud Pública CIBERESP, Barcelona (Spain); García-Lavandeira, José Antonio [Department of Preventive Medicine and Public Health, University of Santiago de Compostela, Santiago de Compostela (Spain); Department of Preventive Medicine, A Coruña University Hospital Complex, Coruña (Spain); Torres-Durán, María [Department of Preventive Medicine and Public Health, University of Santiago de Compostela, Santiago de Compostela (Spain); Service of Neumology, University Hospital Complex of Vigo, Vigo (Spain); Prini-Guadalupe, Luciana [Department of Preventive Medicine and Public Health, University of Santiago de Compostela, Santiago de Compostela (Spain); Parente-Lamelas, Isaura [Service of Neumology, Ourense Hospital Complex, Ourense (Spain); Leiro-Fernández, Virginia [Service of Neumology, University Hospital Complex of Vigo, Vigo (Spain); Montero-Martínez, Carmen [Service of Neumology, University Hospital Complex of A Coruña, Coruña (Spain); González-Barcala, Francisco Javier; Golpe-Gómez, Antonio [Service of Neumology, Santiago de Compostela University Clinic Hospital, Santiago de Compostela (Spain); Martínez, Cristina [National Institute of Silicosis, University Hospital of Asturias, Oviedo, Asturias (Spain); Castro-Añón, Olalla [Service of Neumology, Hospital Lucus Augusti, Lugo (Spain); Mejuto-Martí, María José [Service of Neumology, Hospital Arquitecto Marcide, Ferrol (Spain); and others

2014-07-15

We aim to assess the relationship between leisure time activities related to exposure to carcinogenic substances and lung cancer risk in a hospital-based case-control study performed in never smokers. We included never smoking cases with anatomopathologically confirmed lung cancer and never smoking controls undergoing trivial surgery, at 8 Spanish hospitals. The study was conducted between January 2011 and June 2013. Participants were older than 30 and had no previous neoplasms. All were personally interviewed focusing on lifestyle, environmental tobacco smoke exposure, occupational history and leisure time activities (including duration of such activities). Results were analyzed through logistic regression and adjusted also by residential radon and education level. We included 513 never smokers, 191 cases and 322 controls. The OR for those performing the studied leisure time activities was 1.43 (95%CI 0.78–2.61). When we restricted the analysis to those performing do-it-yourself activities for more than 10 years the OR was 2.21 (95%CI 0.93–5.27). Environmental tobacco smoke exposure did not modify this association. The effect for the different lung cancer histological types was very close to significance for adenocarcinoma but only when these activities were performed for more than 10 years. We encourage health professionals to recommend protective measures for those individuals while performing these hobbies to reduce the risk of lung cancer. - Highlights: • Some leisure time activities are associated with the exposure to carcinogenic substances. • These activities are model-making, painting (artistic or not), furniture refinishing or wood working. • Few studies have assessed lung cancer risk due to these hobbies and none in never-smokers. • Leisure activities related to exposure to carcinogenic substances present higher lung cancer risk. • The risk is higher when these activities are performed for more than 10 years.

Comparing personal alpha dosimetry with the conventional area monitoring-time weighting methods of exposure estimation: a Canadian assessment

International Nuclear Information System (INIS)

Balint, A.B.; Viljoen, J.

1988-01-01

An experimental personal alpha dosimetry program for monitoring exposures of uranium mining facility workers in Canada has been completed. All licenced operating mining facilities were participating. Dosimetry techniques, description of dosimeters used by licences, performance and problems associated with the implementation of the programme as well as technical and administrative advantages and difficulties experienced are discussed. Area monitoring-time weighting methods used and results obtained to determine individual radon and thoron daughter exposure and exposure results generated by using dosimeters are assessed and compared

Time- and dose rate-related effects of internal 177Lu exposure on gene expression in mouse kidney tissue

International Nuclear Information System (INIS)

Schüler, Emil; Rudqvist, Nils; Parris, Toshima Z.; Langen, Britta; Spetz, Johan; Helou, Khalil; Forssell-Aronsson, Eva

2014-01-01

Introduction: The kidneys are the dose-limiting organs in some radionuclide therapy regimens. However, the biological impact of internal exposure from radionuclides is still not fully understood. The aim of this study was to examine the effects of dose rate and time after i.v. injection of 177 LuCl 3 on changes in transcriptional patterns in mouse kidney tissue. Methods: To investigate the effect of dose rate, female Balb/c nude mice were i.v. injected with 11, 5.6, 1.6, 0.8, 0.30, and 0 MBq of 177 LuCl 3 , and killed at 3, 6, 24, 48, 168, and 24 hours after injection, respectively. Furthermore, the effect of time after onset of exposure was analysed using mice injected with 0.26, 2.4, and 8.2 MBq of 177 LuCl 3 , and killed at 45, 90, and 140 days after injection. Global transcription patterns of irradiated kidney cortex and medulla were assessed and enriched biological processes were determined from the regulated gene sets using Gene Ontology terms. Results: The average dose rates investigated were 1.6, 0.84, 0.23, 0.11 and 0.028 mGy/min, with an absorbed dose of 0.3 Gy. At 45, 90 and 140 days, the absorbed doses were estimated to 0.3, 3, and 10 Gy. In general, the number of differentially regulated transcripts increased with time after injection, and decreased with absorbed dose for both kidney cortex and medulla. Differentially regulated transcripts were predominantly involved in metabolic and stress response-related processes dependent on dose rate, as well as transcripts associated with metabolic and cellular integrity at later time points. Conclusion: The observed transcriptional response in kidney tissue was diverse due to difference in absorbed dose, dose rate and time after exposure. Nevertheless, several transcripts were significantly regulated in all groups despite differences in exposure parameters, which may indicate potential biomarkers for exposure of kidney tissue

The optimal UV exposure time for vitamin D3 synthesis and erythema estimated by UV observations in Korea

Science.gov (United States)

Lee, Y. G.; Koo, J. H.

2016-12-01

Solar UV radiation in a wavelength range between 280 to 400 nm has both positive and negative influences on human body. Surface UV radiation is the main natural source of vitamin D, providing the promotion of bone and musculoskeletal health and reducing the risk of a number of cancers and other medical conditions. However, overexposure to surface UV radiation is significantly related with the majority of skin cancer, in addition other negative health effects such as sunburn, skin aging, and some forms of eye cataracts. Therefore, it is important to estimate the optimal UV exposure time, representing a balance between reducing negative health effects and maximizing sufficient vitamin D production. Previous studies calculated erythemal UV and vitamin-D UV from the measured and modelled spectral irradiances, respectively, by weighting CIE Erythema and Vitamin D3 generation functions (Kazantzidis et al., 2009; Fioletov et al., 2010). In particular, McKenzie et al. (2009) suggested the algorithm to estimate vitamin-D production UV from erythemal UV (or UV index) and determined the optimum conditions of UV exposure based on skin type Ⅱ according to the Fitzpatrick (1988). Recently, there are various demands for risks and benefits of surface UV radiation on public health over Korea, thus it is necessary to estimate optimal UV exposure time suitable to skin type of East Asians. This study examined the relationship between erythemally weighted UV (UVEry) and vitamin D weighted UV (UVVitD) from spectral UV measurements during 2006-2010. The temporal variations of the ratio (UVVitD/UVEry) were also analyzed and the ratio as a function of UV index was applied to the broadband UV measured by UV-Biometer at 6 sites in Korea Thus, the optimal UV exposure time for vitamin D3 synthesis and erythema was estimated for diurnal, seasonal, and annual scales over Korea. In summer with high surface UV radiation, short exposure time leaded to sufficient vitamin D and erythema and vice

Military service, deployments, and exposures in relation to amyotrophic lateral sclerosis survival.

Directory of Open Access Journals (Sweden)

John D Beard

Full Text Available Military veterans may have higher rates of amyotrophic lateral sclerosis (ALS mortality than non-veterans. Few studies, with sparse exposure information and mixed results, have studied relationships between military-related factors and ALS survival. We evaluated associations between military-related factors and ALS survival among U.S. military veteran cases.We followed 616 medical record-confirmed cases from enrollment (2005-2010 in the Genes and Environmental Exposures in Veterans with Amyotrophic Lateral Sclerosis study until death or July 25, 2013, whichever came first. We ascertained vital status information from several sources within the Department of Veterans Affairs. We obtained information regarding military service, deployments, and 39 related exposures via standardized telephone interviews. We used Cox proportional hazards regression models to estimate hazard ratios (HRs and 95% confidence intervals. We adjusted for potential confounding and missing covariate data biases via inverse probability weights. We also used inverse probability weights to adjust for potential selection bias among a case group that included a disproportionate number of long-term survivors at enrollment.We observed 446 deaths during 24,267 person-months of follow-up (median follow-up: 28 months. Survival was shorter for cases who served before 1950, were deployed to World War II, or mixed and applied burning agents, with HRs between 1.58 and 2.57. Longer survival was associated with exposure to: paint, solvents, or petrochemical substances; local food not provided by the Armed Forces; or burning agents or Agent Orange in the field with HRs between 0.56 and 0.73.Although most military-related factors were not associated with survival, associations we observed with shorter survival are potentially important because of the large number of military veterans.

[Evaluation of radiation exposure of personnel in an orthopaedic and trauma operation theatre using the new real-time dosimetry system "dose aware"].

Science.gov (United States)

Müller, M C; Strauss, A; Pflugmacher, R; Nähle, C P; Pennekamp, P H; Burger, C; Wirtz, D C

2014-08-01

There is a positive correlation between operation time and staff exposure to radiation during intraoperative use of C-arm fluoroscopy. Due to harmful effects of exposure to long-term low-dose radiation for both the patient and the operating team it should be kept to a minimum. AIM of this study was to evaluate a novel dosimeter system called Dose Aware® (DA) enabling radiation exposure feedback of the personal in an orthopaedic and trauma operation theatre in real-time. Within a prospective study over a period of four month, DA was applied by the operation team during 104 orthopaedic and trauma operations in which the C-arm fluoroscope was used in 2D-mode. During ten operation techniques, radiation exposure of the surgeon, the first assistant, the theatre nurse and the anaesthesiologist was evaluated. Seventy-three operations were analysed. The surgeon achieved the highest radiation exposure during dorsolumbar spinal osteosynthesis, kyphoplasty and screw fixation of sacral fractures. The first assistant received a higher radiation exposure compared to the surgeon during plate osteosynthesis of distal radius fractures (157 %), intramedullary nailing of pertrochanteric fractures (143 %) and dorsolumbar spinal osteosynthesis (240 %). During external fixation of ankle fractures (68 %) and screw fixation of sacral fractures (66 %) radiation exposure of the theatre nurse exceeded 50 % of the surgeon's radiation exposure. During plate osteosynthesis of distal radius fractures (157 %) and intramedullary splinting of clavicular fractures (115 %), the anaesthesiologist received a higher radiation exposure than the surgeon. The novel dosimeter system DA provides real-time radiation exposure feedback of the personnel in an orthopaedic and trauma operation theatre for the first time. Data of this study demonstrate that radiation exposure of the personnel depends on the operation type. The first assistant, the theatre nurse and the anaesthesiologist might be

Bayesian algorithm implementation in a real time exposure assessment model on benzene with calculation of associated cancer risks.

Science.gov (United States)

Sarigiannis, Dimosthenis A; Karakitsios, Spyros P; Gotti, Alberto; Papaloukas, Costas L; Kassomenos, Pavlos A; Pilidis, Georgios A

2009-01-01

The objective of the current study was the development of a reliable modeling platform to calculate in real time the personal exposure and the associated health risk for filling station employees evaluating current environmental parameters (traffic, meteorological and amount of fuel traded) determined by the appropriate sensor network. A set of Artificial Neural Networks (ANNs) was developed to predict benzene exposure pattern for the filling station employees. Furthermore, a Physiology Based Pharmaco-Kinetic (PBPK) risk assessment model was developed in order to calculate the lifetime probability distribution of leukemia to the employees, fed by data obtained by the ANN model. Bayesian algorithm was involved in crucial points of both model sub compartments. The application was evaluated in two filling stations (one urban and one rural). Among several algorithms available for the development of the ANN exposure model, Bayesian regularization provided the best results and seemed to be a promising technique for prediction of the exposure pattern of that occupational population group. On assessing the estimated leukemia risk under the scope of providing a distribution curve based on the exposure levels and the different susceptibility of the population, the Bayesian algorithm was a prerequisite of the Monte Carlo approach, which is integrated in the PBPK-based risk model. In conclusion, the modeling system described herein is capable of exploiting the information collected by the environmental sensors in order to estimate in real time the personal exposure and the resulting health risk for employees of gasoline filling stations.

Examining exposure reciprocity in a resin based composite using high irradiance levels and real-time degree of conversion values.

Science.gov (United States)

Selig, Daniela; Haenel, Thomas; Hausnerová, Berenika; Moeginger, Bernhard; Labrie, Daniel; Sullivan, Braden; Price, Richard B T

2015-05-01

Exposure reciprocity suggests that, as long as the same radiant exposure is delivered, different combinations of irradiance and exposure time will achieve the same degree of resin polymerization. This study examined the validity of exposure reciprocity using real time degree of conversion results from one commercial flowable dental resin. Additionally a new fitting function to describe the polymerization kinetics is proposed. A Plasma Arc Light Curing Unit (LCU) was used to deliver 0.75, 1.2, 1.5, 3.7 or 7.5 W/cm(2) to 2mm thick samples of Tetric EvoFlow (Ivoclar Vivadent). The irradiances and radiant exposures received by the resin were determined using an integrating sphere connected to a fiber-optic spectrometer. The degree of conversion (DC) was recorded at a rate of 8.5 measurements a second at the bottom of the resin using attenuated total reflectance Fourier Transform mid-infrared spectroscopy (FT-MIR). Five specimens were exposed at each irradiance level. The DC reached after 170s and after 5, 10 and 15 J/cm(2) had been delivered was compared using analysis of variance and Fisher's PLSD post hoc multiple comparison tests (alpha=0.05). The same DC values were not reached after the same radiant exposures of 5, 10 and 15 J/cm(2) had been delivered at an irradiance of 3.7 and 7.5 W/cm(2). Thus exposure reciprocity was not supported for Tetric EvoFlow (p<0.05). For Tetric EvoFlow, there was no significant difference in the DC when 5, 10 and 15J/cm(2) were delivered at irradiance levels of 0.75, 1.2 and 1.5 W/cm(2). The optimum combination of irradiance and exposure time for this commercial dental resin may be close to 1.5 W/cm(2) for 12s. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Comparing radiation exposure during percutaneous vertebroplasty using one- vs. two-fluoroscopic technique

Directory of Open Access Journals (Sweden)

Li Yen-Yao

2013-01-01

Full Text Available Abstract Background Percutaneous vertebroplasty (PV requires relatively lengthy fluoroscopic guidance, which might lead to substantial radiation exposure to patients or operators. The two-fluoroscopic technique (two-plane radiographs obtained using two fluoroscopes during PV can provide simultaneous two-planar projections with reducing operative time. However, the two-fluoroscopic technique may expose the operator or patient to increased radiation dose. The aim of this study was to quantify the amount of radiation exposure to the patient or operator that occurs during PV using one- vs. two-fluoroscopic technique. Methods Two radiation dosimeters were placed on the right flank of each patient and on the upper sternum of each operator during 26 single-level PV procedures by one senior surgeon. The use of two-fluoroscopic technique (13 patients and one-fluoroscopic technique (13 patients were allocated in a consecutive and alternative manner. The operative time and mean radiation dose to each patient and operator were monitored and compared between groups. Results Mean radiation dose to the patient was 1.97 ± 1.20 mSv (95% CI, 0.71 to 3.23 for the one-fluoroscopic technique group vs. 0.95 ± 0.34 mSv (95% CI, 0.85 to 1.23 for the two-fluoroscopic technique group (P =0.031. Mean radiation dose to the operator was 0.27 ± 0.12 mSv (95% CI, 0.17–0.56 for the one-fluoroscopic technique group vs. 0.25 ± 0.14 mSv (95% CI, 0.06–0.44 for the two-fluoroscopic technique group (P = 0.653. The operative time was significantly different between groups: 47.15 ± 13.48 min (range, 20–75 for the one-fluoroscopic technique group vs. 36.62 ± 8.42 min (range, 21–50 for the two-fluoroscopic technique group (P =0.019. Conclusion Compared to the one-fluoroscopic technique, the two-fluoroscopic technique used during PV provides not only shorter operative times but also reduces the radiation exposure to the patient. There was no

High lung cancer surgical procedure volume is associated with shorter length of stay and lower risks of re-admission and death

DEFF Research Database (Denmark)

Møller, Henrik; Riaz, Sharma P; Holmberg, Lars

2016-01-01

It is debated whether treating cancer patients in high-volume surgical centres can lead to improvement in outcomes, such as shorter length of hospital stay, decreased frequency and severity of post-operative complications, decreased re-admission, and decreased mortality. The dataset for this anal......It is debated whether treating cancer patients in high-volume surgical centres can lead to improvement in outcomes, such as shorter length of hospital stay, decreased frequency and severity of post-operative complications, decreased re-admission, and decreased mortality. The dataset...... to their geographical population. Higher volume hospitals had shorter length of stay and the odds of re-admission were 15% lower in the highest hospital volume quintile compared with the lowest quintile. Mortality risks were 1% after 30 d and 3% after 90 d. Patients from hospitals in the highest volume quintile had...

DETECTING AND CORRECTING MOTION BLUR FROM IMAGES SHOT WITH CHANNEL-DEPENDENT EXPOSURE TIME

Directory of Open Access Journals (Sweden)

L. Lelégard

2012-07-01

Full Text Available This article describes a pipeline developed to automatically detect and correct motion blur due to the airplane motion in aerial images provided by a digital camera system with channel-dependent exposure times. Blurred images show anisotropy in their Fourier Transform coefficients that can be detected and estimated to recover the characteristics of the motion blur. To disambiguate the anisotropy produced by a motion blur from the possible spectral anisotropy produced by some periodic patterns present in a sharp image, we consider the phase difference of the Fourier Transform of two channel shot with different exposure times (i.e. with different blur extensions. This is possible because of the deep correlation between the three visible channels ensures phase coherence of the Fourier Transform coefficients in sharp images. In this context, considering the phase difference constitutes both a good detector and estimator of the motion blur parameters. In order to improve on this estimation, the phase difference is performed on local windows in the image where the channels are more correlated. The main lobe of the phase difference, where the phase difference between two channels is close to zero actually imitates an ellipse which axis ratio discriminates blur and which orientation and minor axis give respectively the orientation and the blur kernel extension of the long exposure-time channels. However, this approach is not robust to the presence in the phase difference of minor lobes due to phase sign inversions in the Fourier transform of the motion blur. They are removed by considering the polar representation of the phase difference. Based on the blur detection step, blur correction is eventually performed using two different approaches depending on the blur extension size: using either a simple frequency-based fusion for small blur or a semi blind iterative method for larger blur. The higher computing costs of the latter method make it only

Sick building syndrome (SBS) and exposure to water-damaged buildings: time series study, clinical trial and mechanisms.

Science.gov (United States)

Shoemaker, Ritchie C; House, Dennis E

2006-01-01

Occupants of water-damaged buildings (WDBs) with evidence of microbial amplification often describe a syndrome involving multiple organ systems, commonly referred to as "sick building syndrome" (SBS), following chronic exposure to the indoor air. Studies have demonstrated that the indoor air of WDBs often contains a complex mixture of fungi, mycotoxins, bacteria, endotoxins, antigens, lipopolysaccharides, and biologically produced volatile compounds. A case-series study with medical assessments at five time points was conducted to characterize the syndrome after a double-blinded, placebo-controlled clinical trial conducted among a group of study participants investigated the efficacy of cholestyramine (CSM) therapy. The general hypothesis of the time series study was that chronic exposure to the indoor air of WDBs is associated with SBS. Consecutive clinical patients were screened for diagnosis of SBS using criteria of exposure potential, symptoms involving at least five organ systems, and the absence of confounding factors. Twenty-eight cases signed voluntary consent forms for participation in the time-series study and provided samples of microbial contaminants from water-damaged areas in the buildings they occupied. Twenty-six participants with a group-mean duration of illness of 11 months completed examinations at all five study time points. Thirteen of those participants also agreed to complete a double-blinded, placebo-controlled clinical trial. Data from Time Point 1 indicated a group-mean of 23 out of 37 symptoms evaluated; and visual contrast sensitivity (VCS), an indicator of neurological function, was abnormally low in all participants. Measurements of matrix metalloproteinase 9 (MMP9), leptin, alpha melanocyte stimulating hormone (MSH), vascular endothelial growth factor (VEGF), immunoglobulin E (IgE), and pulmonary function were abnormal in 22, 13, 25, 14, 1, and 7 participants, respectively. Following 2 weeks of CSM therapy to enhance toxin elimination

Changes in indinavir exposure over time : a case study in six HIV-1-infected children

NARCIS (Netherlands)

Fraaij, PLA; Bergshoeff, AS; van Rossum, AMC; Hartwig, NG; Burger, DM; de Groot, R

2003-01-01

Objective: To study changes in indinavir exposure over time in HIV-1-infected children. Materials and methods: Protease inhibitor (PI)-naive HIV-1-infected children were treated with indinavir, zidovudine and lamivudine. Steady-state plasma pharmacokinetic (PK) sampling was carried out as standard

Development of real-time radiation exposure dosimetry system using synthetic ruby for interventional radiology

International Nuclear Information System (INIS)

Hosokai, Yoshiyuki; Win, Thet Pe; Muroi, Kenzo; Matsumoto, Kenki; Takahashi, Kaito; Usui, Akihito; Saito, Haruo; Kozakai, Masataka

2017-01-01

Interventional radiology (IVR) tends to involve long procedures, consequently delivering high radiation doses to the patient. Radiation-induced injuries that occur because of the effect of the high radiation doses are a considerable problem for those performing IVR. For example, skin injuries can include skin erythema if the skin is exposed to radiation doses beyond the threshold level of 2 Gy. One of the reasons for this type of injury is that the local skin dose cannot be monitored in real time. Although there are systems employed to measure the exposure dose, some do not work in real time (such as thermoluminescence dosimeters and fluorescent glass dosimeters), while certain real-time measurement systems that enter the field of view (such as patient skin dosimeters and dosimeters using a nontoxic phosphor) interfere with IVR. However, synthetic ruby has been shown to emit light in response to radiation. The luminous wavelength is 693 nm. It is possible to monitor the radiation dose by detecting the emitted light. However, small synthetic rubies emit a tiny amount of light that is difficult to detect using common systems such as photodiodes. A large enough synthetic ruby to increase the quantity of emitted light would however enter the field of view and interfere with the IVR procedure. Additionally, although a photodiode system could reduce the system size, the data is susceptible to effects from the X-rays and outside temperature. Therefore, use of a sensitive photon counting system as used in nuclear medicine could potentially have a beneficial effect in detecting the weak light signal. A real-time radiation exposure dosimetry system for use in IVR should be sufficiently sensitive, not interfere with the IVR procedure, and ideally have the possibility of development into a system that can provide simultaneous multipoint measurements. This article discusses the development of a realtime radiation exposure dosimetry system for use in IVR that employs a small

Reprocessing WFC3/IR Exposures Affected by Time-Variable Backgrounds

Science.gov (United States)

Brammer, G.

2016-11-01

The background seen in WFC3/IR observations frequently shows strong time-dependent behavior above the constant flux expected for zodiacal continuum light. This is often caused by an emission line of helium at 1.083 μm excited in the sun-illuminated upper atmosphere, when seen in the filters (F105W, F110W) and grisms (G102, G141) sensitive to the feature. The default behavior of the calwf3 pipeline assumes constant source-plus-background fluxes when it performs up-the-ramp fitting to identify cosmic rays and determine the average count rate within a MULTIACCUM IR exposure. calwf3 provides undesirable results in the presence of strongly variable backgrounds, primarily in the form of elevated and non-Gaussian noise in the FLT products. Here we describe methods to improve the noise properties of the reduced products. In the first, we simply turn off the calwf3 crcorr step, treating the IR detector as if it were a CCD, i.e., accumulating flux and reading it out at the end of the exposure. Next, we artificially flatten the ramps in the IMA products and then allow calwf3 to proceed as normal fitting the ramp and identifying CRs. Either of these procedures enable recovery of datasets otherwise corrupted beyond repair and have no discernible effects on photometry of sources in deep combined images.

Effects of High-Temperature Exposures on the Fatigue Life of Superalloy Udimet(Registered Trademark) 720

Science.gov (United States)

Gabb, Timothy P.; Telesman, Jack; Kantzos, Peter T.; Sweeney, Joseph W.; Browning, Paul F.

2002-01-01

The purpose of this study was to examine the effects of extended exposures on the near-surface fatigue resistance of a disk superalloy. Powder metallurgy processed, supersolvus heat-treated Udimet 720 (U720) fatigue specimens were exposed in air at temperatures from 650 to 705 C for 100 hr to over 1000 hr. They were then tested using conventional fatigue tests at 650 C to determine the effects of exposure on fatigue resistance. The exposures reduced life by up to 70% and increased the scatter in life, compared to unexposed levels. Fractographic evaluations indicated the failure mode was shifted by the exposures from internal to surface crack initiations. The increased scatter in life was related to the competition between internal crack initiations at inclusions or large grains producing longer lives, and surface crack initiations at an environmentally affected surface layer producing shorter lives.

Reevaluation of time spent indoors used for exposure dose assessment

International Nuclear Information System (INIS)

Hirose, Katsumi; Fujimoto, Kenzo

2016-01-01

A time spent indoors of sixteen hours per day (indoor occupancy factor: 0.67) has been used to assess the radiation dose of residents who spend daily life in the area contaminated due to the nuclear accident in Japan. However, much longer time is considered to be spent indoors for recent modern life. United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has been used an indoor occupancy factor of 0.8 since 1977 and a few reports suggested much higher indoor occupancy factors. Therefore it is important to reevaluate the indoor occupancy factor using current available survey data in Japan, such as 'NHK 2010 National Time Use Survey' and 'Survey on Time Use and Leisure Activities' of Statistics Bureau with certain assumption of time spent indoors in each daily activity. The total time spent indoors in a day is calculated to be 20.2 hours and its indoor occupancy factor is 0.84. Much lower indoor occupancy factors were derived from the survey data by Statistics Bureau for 10 to 14 and 15 to 19 years old groups and farmers who spend most of their time outdoors although present estimated indoor occupancy factor of 0.84 is still lower than those found in some of the relevant reports. A rounded indoor occupancy factor of 0.80 might be the appropriate conservative reference value to be used for the dose estimation of people who live in radioactively contaminated areas and for other relevant purposes of exposure assessment, taken into consideration the present results and values reported in United States Environmental Protection Agency (US EPA) and UNSCEAR. (author)

Photometrically measured continuous personal PM(2.5) exposure: levels and correlation to a gravimetric method.

Science.gov (United States)

Lanki, Timo; Alm, Sari; Ruuskanen, Juhani; Janssen, Nicole A H; Jantunen, Matti; Pekkanen, Juha

2002-05-01

There is evidence that hourly variations in exposure to airborne particulate matter (PM) may be associated with adverse health effects. Still there are only few published data on short-term levels of personal exposure to PM in community settings. The objectives of the study were to assess hourly and shorter-term variations in personal PM(2.5) exposure in Helsinki, Finland, and to compare results from portable photometers to simultaneously measured gravimetric concentrations. The effect of relative humidity on the photometric results was also evaluated. Personal PM(2.5) exposures of elderly persons were assessed for 24 h every second week, resulting in 308 successful measurements from 47 different subjects. Large changes in concentrations in minutes after cooking or changing microenvironment were seen. The median of daily 1-h maxima was over twice the median of 24-h averages. There was a strong significant association between the two means, which was not linear. Median (95th percentile) of the photometric 24-h concentrations was 12.1 (37.7) and of the 24-h gravimetric concentrations 9.2 (21.3) microg/m3. The correlation between the photometric and the gravimetric method was quite good (R2=0.86). Participants spent 94.1% of their time indoors or in a vehicle, where relative humidity is usually low and thus not likely to cause significant effects on photometric results. Even outdoors, the relative humidity had only modest effect on concentrations. Photometers are a promising method to explore the health effects of short-term variation in personal PM(2.5) exposure.

Construction time of PWRs

Energy Technology Data Exchange (ETDEWEB)

Carajilescov, Pedro; Moreira, Joao M.L., E-mail: pedro.carajilescov@ufabc.edu.b, E-mail: joao.moreira@ufabc.edu.b [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil). Center of Engineering, Modeling and Applied Social Sciences

2011-07-01

The cost of electricity generated by nuclear power is greatly affected by the capital cost, which is dependent on the construction time of the plant. This work analyses the construction time of PWRs in several countries with different market structure and licensing experience. Countries which succeeded to establish a more collaborative environment among utilities, constructors, regulators, and energy planners through effective partnerships were able to build PWRs in shorter times. The construction time in Germany, France and Russia was around 80 months and in Japan, about 60 months. The envelope of 95% of the cases includes a range between 50 and 250 months of construction time. The evaluations show that construction time of PWRs has been longer for countries that did not hold the technology to build their own reactors, and depended on contracts with foreign suppliers. The nominal power of the reactors was considered a measure of plant size, technology complexity and standardization. Countries with standardized reactor designs (France, Japan and Russia) were able to build plants in shorter times. (author)

Construction time of PWRs

International Nuclear Information System (INIS)

Carajilescov, Pedro; Moreira, Joao M.L.

2011-01-01

The cost of electricity generated by nuclear power is greatly affected by the capital cost, which is dependent on the construction time of the plant. This work analyses the construction time of PWRs in several countries with different market structure and licensing experience. Countries which succeeded to establish a more collaborative environment among utilities, constructors, regulators, and energy planners through effective partnerships were able to build PWRs in shorter times. The construction time in Germany, France and Russia was around 80 months and in Japan, about 60 months. The envelope of 95% of the cases includes a range between 50 and 250 months of construction time. The evaluations show that construction time of PWRs has been longer for countries that did not hold the technology to build their own reactors, and depended on contracts with foreign suppliers. The nominal power of the reactors was considered a measure of plant size, technology complexity and standardization. Countries with standardized reactor designs (France, Japan and Russia) were able to build plants in shorter times. (author)

Comparison of pesticide exposure and physical examination, neurological assessment, and laboratory findings between full-time and part-time vegetable farmers in the Philippines.

Science.gov (United States)

Lu, Jinky Leilanie

2009-11-01

This study aimed to compare the work practices and health effects of pesticide exposure between full-time and part-time vegetable farmers. Data was gathered via structured personal interview using a 9-page questionnaire, physical examination, and blood extraction for complete blood count and serum creatinine. Pyrethroid was the pesticide type most used by both groups. The risk for full-time farmers was related to both the amount of exposure and the type of pesticide. There were more full-time farmers who complained of falling ill because of work. This difference was statistically significant (P = 0.05). The level of those seeking medical attention was also significantly different between the two groups (P = 0.01). In assessing the individual components of the neurologic examination, 5.22% of full-time and 8.63% of part-time farmers had abnormal cranial nerve function, and 22 (5.7%) and 9 (6.47%) had abnormal motor strength. All farmers tested for reflexes, meningeals, and autonomics from both groups were normal. Based on hematologic examination, full-time farmers had higher mean values for creatinine, white blood cell, red blood cell, hemoglobin, and hematocrit. Activity of cholinesterase enzymes in blood can be utilized as a biomarker for the effect of organophosphates; of the 232 blood cholinesterase results, 94 (40%) were abnormal. The study showed certain differences between full-time and part-time farmers in terms of farming practices and health-related problems. Education on safe pesticide use and handling and better health monitoring of the farmers are recommended.

Retention of Idioms Following One-Time Exposure

Science.gov (United States)

Reuterskiold, Christina; Van Lancker Sidtis, Diana

2013-01-01

This study explored retention of idioms and novel (i.e. newly created or grammatically generated) expressions in English-speaking girls following exposure only once during a conversation. Our hypothesis was that idioms, because of their inherent holistic, nonliteral and social characteristics, are acquired differently and more rapidly than novel…

Population models for time-varying pesticide exposure

NARCIS (Netherlands)

Jager T; Jong FMW de; Traas TP; LER; SEC

2007-01-01

A model has recently been developed at RIVM to predict the effects of variable exposure to pesticides of plant and animal populations in surface water. Before a pesticide is placed on the market, the environmental risk of the substance has to be assessed. This risk is estimated by comparing

Fetal magnetic resonance imaging: exposure times and functional outcomes at preschool age

Energy Technology Data Exchange (ETDEWEB)

Bouyssi-Kobar, Marine [George Washington University, Institute for Biomedical Sciences, Washington, DC (United States); Children' s National Health System, Advanced Pediatric Brain Imaging Research Laboratory, Departments of Diagnostic Imaging and Radiology, Washington, DC (United States); Du Plessis, Adre J. [Children' s National Health System, Fetal and Transitional Medicine, Washington, DC (United States); Robertson, Richard L. [Children' s Hospital Boston and Harvard Medical School, Department of Radiology, Boston, MA (United States); Limperopoulos, Catherine [Children' s National Health System, Advanced Pediatric Brain Imaging Research Laboratory, Departments of Diagnostic Imaging and Radiology, Washington, DC (United States); Children' s National Health System, Fetal and Transitional Medicine, Washington, DC (United States)

2015-11-15

Fetal magnetic resonance imaging (MRI) has been routinely used as a noninvasive diagnostic tool for more than a decade; however, there is a paucity of follow-up studies examining the effects of prenatal exposure to 1.5-T MRI on developmental outcome. The objective of this study was to assess the safety of 1.5-T fetal MRI by evaluating functional outcomes of preschool children who were exposed in utero. In the context of a prospective observational study, healthy pregnant women underwent a 1.5-T MRI study using single-shot fast spin echo (SSFSE) sequences during the second or third trimester of pregnancy. The study was approved by the institutional review board at our institution, and written informed consent was obtained from all study participants. MRI scanning times were recorded, and prenatal/postnatal clinical data were collected prospectively. Functional outcomes were assessed using the Vineland Adaptive Behavior Scale (VABS), a widely used, norm-referenced and psychometrically sound functional assessment. We studied 72 healthy pregnant women, who underwent fetal MRI at a mean gestational age of 30.5 ± 3.1 weeks. The cohort of fetuses was composed of 43% females, and 18 fetuses were scanned during the second trimester. All fetuses were born at term with appropriate birth weights (3.54 ± 0.5 kg) for gestational age. Mean age at follow-up testing was 24.5 ± 6.7 months. All children had age-appropriate scores in the communication, daily living, socialization and motor skills subdomains of the VABS (z-scores, P > 0.05). Furthermore, all children passed their newborn otoacoustic emission test and had normal hearing at preschool age. MRI study duration and exposure time to radio frequency waves and SSFSE sequences were not associated with adverse functional outcomes or hearing impairment. Prenatal exposure to 1.5-T MRI during the second or third trimester of pregnancy in a cohort of healthy fetuses is not associated with disturbances in functional outcomes or

Fetal magnetic resonance imaging: exposure times and functional outcomes at preschool age

International Nuclear Information System (INIS)

Bouyssi-Kobar, Marine; Du Plessis, Adre J.; Robertson, Richard L.; Limperopoulos, Catherine

2015-01-01

Fetal magnetic resonance imaging (MRI) has been routinely used as a noninvasive diagnostic tool for more than a decade; however, there is a paucity of follow-up studies examining the effects of prenatal exposure to 1.5-T MRI on developmental outcome. The objective of this study was to assess the safety of 1.5-T fetal MRI by evaluating functional outcomes of preschool children who were exposed in utero. In the context of a prospective observational study, healthy pregnant women underwent a 1.5-T MRI study using single-shot fast spin echo (SSFSE) sequences during the second or third trimester of pregnancy. The study was approved by the institutional review board at our institution, and written informed consent was obtained from all study participants. MRI scanning times were recorded, and prenatal/postnatal clinical data were collected prospectively. Functional outcomes were assessed using the Vineland Adaptive Behavior Scale (VABS), a widely used, norm-referenced and psychometrically sound functional assessment. We studied 72 healthy pregnant women, who underwent fetal MRI at a mean gestational age of 30.5 ± 3.1 weeks. The cohort of fetuses was composed of 43% females, and 18 fetuses were scanned during the second trimester. All fetuses were born at term with appropriate birth weights (3.54 ± 0.5 kg) for gestational age. Mean age at follow-up testing was 24.5 ± 6.7 months. All children had age-appropriate scores in the communication, daily living, socialization and motor skills subdomains of the VABS (z-scores, P > 0.05). Furthermore, all children passed their newborn otoacoustic emission test and had normal hearing at preschool age. MRI study duration and exposure time to radio frequency waves and SSFSE sequences were not associated with adverse functional outcomes or hearing impairment. Prenatal exposure to 1.5-T MRI during the second or third trimester of pregnancy in a cohort of healthy fetuses is not associated with disturbances in functional outcomes or

Reducing placebo exposure in trials: Considerations from the Research Roundtable in Epilepsy.

Science.gov (United States)

Fureman, Brandy E; Friedman, Daniel; Baulac, Michel; Glauser, Tracy; Moreno, Jonathan; Dixon-Salazar, Tracy; Bagiella, Emilia; Connor, Jason; Ferry, Jim; Farrell, Kathleen; Fountain, Nathan B; French, Jacqueline A

2017-10-03

The randomized controlled trial is the unequivocal gold standard for demonstrating clinical efficacy and safety of investigational therapies. Recently there have been concerns raised about prolonged exposure to placebo and ineffective therapy during the course of an add-on regulatory trial for new antiepileptic drug approval (typically ∼6 months in duration), due to the potential risks of continued uncontrolled epilepsy for that period. The first meeting of the Research Roundtable in Epilepsy on May 19-20, 2016, focused on "Reducing placebo exposure in epilepsy clinical trials," with a goal of considering new designs for epilepsy regulatory trials that may be added to the overall development plan to make it, as a whole, safer for participants while still providing rigorous evidence of effect. This topic was motivated in part by data from a meta-analysis showing a 3- to 5-fold increased rate of sudden unexpected death in epilepsy in participants randomized to placebo or ineffective doses of new antiepileptic drugs. The meeting agenda included rationale and discussion of different trial designs, including active-control add-on trials, placebo add-on to background therapy with adjustment, time to event designs, adaptive designs, platform trials with pooled placebo control, a pharmacokinetic/pharmacodynamic approach to reducing placebo exposure, and shorter trials when drug tolerance has been ruled out. The merits and limitations of each design were discussed and are reviewed here. © 2017 American Academy of Neurology.

Complexities of sibling analysis when exposures and outcomes change with time and birth order.

Science.gov (United States)

Sudan, Madhuri; Kheifets, Leeka I; Arah, Onyebuchi A; Divan, Hozefa A; Olsen, Jørn

2014-01-01

In this study, we demonstrate the complexities of performing a sibling analysis with a re-examination of associations between cell phone exposures and behavioral problems observed previously in the Danish National Birth Cohort. Children (52,680; including 5441 siblings) followed up to age 7 were included. We examined differences in exposures and behavioral problems between siblings and non-siblings and by birth order and birth year. We estimated associations between cell phone exposures and behavioral problems while accounting for the random family effect among siblings. The association of behavioral problems with both prenatal and postnatal exposure differed between siblings (odds ratio (OR): 1.07; 95% confidence interval (CI): 0.69-1.66) and non-siblings (OR: 1.54; 95% CI: 1.36-1.74) and within siblings by birth order; the association was strongest for first-born siblings (OR: 1.72; 95% CI: 0.86-3.42) and negative for later-born siblings (OR: 0.63; 95% CI: 0.31-1.25), which may be because of increases in cell phone use with later birth year. Sibling analysis can be a powerful tool for (partially) accounting for confounding by invariant unmeasured within-family factors, but it cannot account for uncontrolled confounding by varying family-level factors, such as those that vary with time and birth order.

Bayesian Algorithm Implementation in a Real Time Exposure Assessment Model on Benzene with Calculation of Associated Cancer Risks

Directory of Open Access Journals (Sweden)

Pavlos A. Kassomenos

2009-02-01

Full Text Available The objective of the current study was the development of a reliable modeling platform to calculate in real time the personal exposure and the associated health risk for filling station employees evaluating current environmental parameters (traffic, meteorological and amount of fuel traded determined by the appropriate sensor network. A set of Artificial Neural Networks (ANNs was developed to predict benzene exposure pattern for the filling station employees. Furthermore, a Physiology Based Pharmaco-Kinetic (PBPK risk assessment model was developed in order to calculate the lifetime probability distribution of leukemia to the employees, fed by data obtained by the ANN model. Bayesian algorithm was involved in crucial points of both model sub compartments. The application was evaluated in two filling stations (one urban and one rural. Among several algorithms available for the development of the ANN exposure model, Bayesian regularization provided the best results and seemed to be a promising technique for prediction of the exposure pattern of that occupational population group. On assessing the estimated leukemia risk under the scope of providing a distribution curve based on the exposure levels and the different susceptibility of the population, the Bayesian algorithm was a prerequisite of the Monte Carlo approach, which is integrated in the PBPK-based risk model. In conclusion, the modeling system described herein is capable of exploiting the information collected by the environmental sensors in order to estimate in real time the personal exposure and the resulting health risk for employees of gasoline filling stations.

Resilience and recovery: The effect of triclosan exposure timing during development, on the structure and function of river biofilm communities

Energy Technology Data Exchange (ETDEWEB)

Lawrence, J.R., E-mail: john.lawrence@ec.gc.ca [Environment Canada, 11 Innovation Blvd., Saskatoon, SK S7N 3H5 (Canada); Topp, E. [Agriculture and Agri-Food Canada, London, ON (Canada); Waiser, M.J.; Tumber, V.; Roy, J.; Swerhone, G.D.W. [Environment Canada, 11 Innovation Blvd., Saskatoon, SK S7N 3H5 (Canada); Leavitt, P. [University of Regina, Regina, SK (Canada); Paule, A. [Global Institute for Water Security, University of Saskatchewan, Saskatoon, SK (Canada); Korber, D.R. [Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, SK (Canada)

2015-04-15

Highlights: • Triclosan negatively affected structure and metabolism of biofilms under all exposure conditions. • Biofilm age, timing and exposure regime alter the effects of triclosan. • Regardless of exposure regime algae and cyanobacteria were the most affected. • Although recovery was evident no community regained the reference condition. • Initial recruitment may be significant in determining community recovery. - Abstract: Triclosan (TCS) is a ubiquitous antibacterial agent found in soaps, scrubs, and consumer products. There is limited information on hazardous effects of TCS in the environment. Here, rotating annular reactors were used to cultivate river biofilm communities exposed to 1.8 μg l{sup −1} TCS with the timing and duration of exposure and recovery during development varied. Two major treatment regimens were employed: (i) biofilm development for 2, 4 or 6 weeks prior to TCS exposure and (ii) exposure of biofilms to TCS for 2, 4 or 6 weeks followed by recovery. Biofilms not exposed to TCS were used as a reference condition. Communities cultivated without and then exposed to TCS all exhibited reductions in algal biomass and significant (p < 0.05) reductions in cyanobacterial biomass. No significant effects were observed on bacterial biomass. CLSM imaging of biofilms at 8 weeks revealed unique endpoints in terms of community architecture. Community composition was altered by any exposure to TCS, as indicated by significant shifts in denaturing gradient gel electrophoresis fingerprints and exopolymer composition relative to the reference. Bacterial, algal and cyanobacterial components initially exposed to TCS were significantly different from those TCS-free at time zero. Pigment analyses suggested that significant changes in composition of algal and cyanobacterial populations occurred with TCS exposure. Bacterial thymidine incorporation rates were reduced by TCS exposure and carbon utilization spectra shifted in terms substrate metabolism

Resilience and recovery: The effect of triclosan exposure timing during development, on the structure and function of river biofilm communities

International Nuclear Information System (INIS)

Lawrence, J.R.; Topp, E.; Waiser, M.J.; Tumber, V.; Roy, J.; Swerhone, G.D.W.; Leavitt, P.; Paule, A.; Korber, D.R.

2015-01-01

Highlights: • Triclosan negatively affected structure and metabolism of biofilms under all exposure conditions. • Biofilm age, timing and exposure regime alter the effects of triclosan. • Regardless of exposure regime algae and cyanobacteria were the most affected. • Although recovery was evident no community regained the reference condition. • Initial recruitment may be significant in determining community recovery. - Abstract: Triclosan (TCS) is a ubiquitous antibacterial agent found in soaps, scrubs, and consumer products. There is limited information on hazardous effects of TCS in the environment. Here, rotating annular reactors were used to cultivate river biofilm communities exposed to 1.8 μg l −1 TCS with the timing and duration of exposure and recovery during development varied. Two major treatment regimens were employed: (i) biofilm development for 2, 4 or 6 weeks prior to TCS exposure and (ii) exposure of biofilms to TCS for 2, 4 or 6 weeks followed by recovery. Biofilms not exposed to TCS were used as a reference condition. Communities cultivated without and then exposed to TCS all exhibited reductions in algal biomass and significant (p < 0.05) reductions in cyanobacterial biomass. No significant effects were observed on bacterial biomass. CLSM imaging of biofilms at 8 weeks revealed unique endpoints in terms of community architecture. Community composition was altered by any exposure to TCS, as indicated by significant shifts in denaturing gradient gel electrophoresis fingerprints and exopolymer composition relative to the reference. Bacterial, algal and cyanobacterial components initially exposed to TCS were significantly different from those TCS-free at time zero. Pigment analyses suggested that significant changes in composition of algal and cyanobacterial populations occurred with TCS exposure. Bacterial thymidine incorporation rates were reduced by TCS exposure and carbon utilization spectra shifted in terms substrate metabolism

Computer tomography urography assisted real-time ultrasound-guided percutaneous nephrolithotomy on renal calculus.

Science.gov (United States)

Fang, You-Qiang; Wu, Jie-Ying; Li, Teng-Cheng; Zheng, Hao-Feng; Liang, Guan-Can; Chen, Yan-Xiong; Hong, Xiao-Bin; Cai, Wei-Zhong; Zang, Zhi-Jun; Di, Jin-Ming

2017-06-01

This study aimed to assess the role of pre-designed route on computer tomography urography (CTU) in the ultrasound-guided percutaneous nephrolithotomy (PCNL) for renal calculus.From August 2013 to May 2016, a total of 100 patients diagnosed with complex renal calculus in our hospital were randomly divided into CTU group and control group (without CTU assistance). CTU was used to design a rational route for puncturing in CTU group. Ultrasound was used in both groups to establish a working trace in the operation areas. Patients' perioperative parameters and postoperative complications were recorded.All operations were successfully performed, without transferring to open surgery. Time of channel establishment in CTU group (6.5 ± 4.3 minutes) was shorter than the control group (10.0 ± 6.7 minutes) (P = .002). In addition, there was shorter operation time, lower rates of blood transfusion, secondary operation, and less establishing channels. The incidence of postoperative complications including residual stones, sepsis, severe hemorrhage, and perirenal hematoma was lower in CTU group than in control group.Pre-designing puncture route on CTU images would improve the puncturing accuracy, lessen establishing channels as well as improve the security in the ultrasound-guided PCNL for complex renal calculus, but at the cost of increased radiation exposure.

Estimating Benzene Exposure Level over Time and by Industry Type through a Review of Literature on Korea.

Science.gov (United States)

Park, Donguk; Choi, Sangjun; Ha, Kwonchul; Jung, Hyejung; Yoon, Chungsik; Koh, Dong-Hee; Ryu, Seunghun; Kim, Soogeun; Kang, Dongmug; Yoo, Kyemook

2015-09-01

The major purpose of this study is to construct a retrospective exposure assessment for benzene through a review of literature on Korea. Airborne benzene measurements reported in 34 articles were reviewed. A total of 15,729 individual measurements were compiled. Weighted arithmetic means [AM(w)] and their variance calculated across studies were summarized according to 5-year period intervals (prior to the 1970s through the 2010s) and industry type. Industries were classified according to Korea Standard Industrial Classification (KSIC) using information provided in the literature. We estimated quantitative retrospective exposure to benzene for each cell in the matrix through a combination of time and KSIC. Analysis of the AM(w) indicated reductions in exposure levels over time, regardless of industry, with mean levels prior to the 1980-1984 period of 50.4 ppm (n = 2,289), which dropped to 2.8 ppm (n = 305) in the 1990-1994 period, and to 0.1 ppm (n = 294) in the 1995-1999 period. There has been no improvement since the 2000s, when the AM(w) of 4.3 ppm (n = 6,211) for the 2005-2009 period and 4.5 ppm (n = 3,358) for the 2010-2013 period were estimated. A comparison by industry found no consistent patterns in the measurement results. Our estimated benzene measurements can be used to determine not only the possibility of retrospective exposure to benzene, but also to estimate the level of quantitative or semiquantitative retrospective exposure to benzene.

Effect of prolonged exposure to low antigen concentration for sensitization

International Nuclear Information System (INIS)

Och, Francois M.M. van; Vandebriel, Rob J.; Jong, Wim H. de; Loveren, Henk van

2003-01-01

The local lymph node assay (LLNA) is an assay in mice to identify potential allergens. Compounds that do not induce a stimulation index (SI)≥3 are not considered sensitizers. Of the chemicals that do, the SI of 3 is used as a benchmark, and indicates the sensitizing potency of a chemical. Compared to the exposure duration of the LLNA (3 days), real life exposure often lasts for months or years. We therefore investigated whether prolonged exposure to sensitizers at concentrations that do not induce a SI≥3 in the LLNA, were able to surpass this threshold. Mice were treated for 2 months at 7-day intervals with a range of concentrations of the known allergens ethyl-p-aminobenzoate (benzocaine, BENZ), 2,4-dinitrochlorobenzene (DNCB), and tetramethyl thiuram disulfide (TMTD). Both proliferative activity and cytokine production were established at day 60. Neither BENZ nor TMTD showed a significant increase in the proliferation rate compared to vehicle controls. Only DNCB at concentrations originally above the EC 3 a significant increase in proliferation was seen after prolonged exposure. No significant effect on IFN-γ and IL-4 production was observed for all three compounds compared. These findings indicate that for classification of sensitizers the shorter exposure period employed in the standard LLNA is sufficient, and longer periods of exposure have no bearing on this classification

Shorter Fallow Cycles Affect the Availability of Noncrop Plant Resources in a Shifting Cultivation System

Directory of Open Access Journals (Sweden)

Sarah Paule. Dalle

2006-12-01

Full Text Available Shifting cultivation systems, one of the most widely distributed forms of agriculture in the tropics, provide not only crops of cultural significance, but also medicinal, edible, ritual, fuel, and forage resources, which contribute to the livelihoods, health, and cultural identity of local people. In many regions across the globe, shifting cultivation systems are undergoing important changes, one of the most pervasive being a shortening of the fallow cycle. Although there has been much attention drawn to declines in crop yields in conjunction with reductions in fallow times, little if any research has focused on the dynamics of noncrop plant resources. In this paper, we use a data set of 26 fields of the same age, i.e., ~1.5 yr, but differing in the length and frequency of past fallow cycles, to examine the impact of shorter fallow periods on the availability of noncrop plant resources. The resources examined are collected in shifting cultivation fields by the Yucatec Maya in Quintana Roo, Mexico. These included firewood, which is cut from remnant trees and stumps spared at the time of felling, and 17 forage species that form part of the weed vegetation. Firewood showed an overall decrease in basal area with shorter fallow cycles, which was mostly related to the smaller diameter of the spared stumps and trees in short-fallow milpas. In contrast, forage species showed a mixed response. Species increasing in abundance in short-fallow milpas tended to be short-lived herbs and shrubs often with weedy habits, whereas those declining in abundance were predominantly pioneer trees and animal-dispersed species. Coppicing tree species showed a neutral response to fallow intensity. Within the cultural and ecological context of our study area, we expect that declines in firewood availability will be most significant for livelihoods because of the high reliance on firewood for local fuel needs and the fact that the main alternative source of firewood, forest

Development of the town data base: Estimates of exposure rates and times of fallout arrival near the Nevada Test Site

International Nuclear Information System (INIS)

Thompson, C.B.; McArthur, R.D.; Hutchinson, S.W.

1994-09-01

As part of the U.S. Department of Energy's Off-Site Radiation Exposure Review Project, the time of fallout arrival and the H+12 exposure rate were estimated for populated locations in Arizona, California, Nevada, and Utah that were affected by fallout from one or more nuclear tests at the Nevada Test Site. Estimates of exposure rate were derived from measured values recorded before and after each test by fallout monitors in the field. The estimate for a given location was obtained by retrieving from a data base all measurements made in the vicinity, decay-correcting them to H+12, and calculating an average. Estimates were also derived from maps produced after most events that show isopleths of exposure rate and time of fallout arrival. Both sets of isopleths on these maps were digitized, and kriging was used to interpolate values at the nodes of a 10-km grid covering the pattern. The values at any location within the grid were then estimated from the values at the surrounding grid nodes. Estimates of dispersion (standard deviation) were also calculated. The Town Data Base contains the estimates for all combinations of location and nuclear event for which the estimated mean H+12 exposure rate was greater than three times background. A listing of the data base is included as an appendix. The information was used by other project task groups to estimate the radiation dose that off-site populations and individuals may have received as a result of exposure to fallout from Nevada nuclear tests

The solar UV exposure time required for vitamin D3 synthesis in the human body estimated by numerical simulation and observation in Japan

Science.gov (United States)

Nakajima, Hideaki; Miyauchi, Masaatsu; Hirai, Chizuko

2013-04-01

After the discovery of Antarctic ozone hole, the negative effect of exposure of human body to harmful solar ultraviolet (UV) radiation is widely known. However, there is positive effect of exposure to UV radiation, i.e., vitamin D synthesis. Although the importance of solar UV radiation for vitamin D3 synthesis in the human body is well known, the solar exposure time required to prevent vitamin D deficiency has not been well determined. This study attempted to identify the time of solar exposure required for vitamin D3 synthesis in the body by season, time of day, and geographic location (Sapporo, Tsukuba, and Naha, in Japan) using both numerical simulations and observations. According to the numerical simulation for Tsukuba at noon in July under a cloudless sky, 2.3 min of solar exposure are required to produce 5.5 μg vitamin D3 per 600 cm2 skin. This quantity of vitamin D represents the recommended intake for an adult by the Ministry of Health, Labour and Welfare, and the 2010 Japanese Dietary Reference Intakes (DRIs). In contrast, it took 49.5 min to produce the same amount of vitamin D3 at Sapporo in the northern part of Japan in December, at noon under a cloudless sky. The necessary exposure time varied considerably with the time of the day. For Tsukuba at noon in December, 14.5 min were required, but at 09:00 68.7 min were required and at 15:00 175.8 min were required for the same meteorological conditions. Naha receives high levels of UV radiation allowing vitamin D3 synthesis almost throughout the year. According to our results, we are further developing an index to quantify the necessary time of UV radiation exposure to produce required amount of vitamin D3 from a UV radiation data.

Analytic strategies to evaluate the association of time-varying exposures to HIV-related outcomes: Alcohol consumption as an example.

Science.gov (United States)

Cook, Robert L; Kelso, Natalie E; Brumback, Babette A; Chen, Xinguang

2016-01-01

As persons with HIV are living longer, there is a growing need to investigate factors associated with chronic disease, rate of disease progression and survivorship. Many risk factors for this high-risk population change over time, such as participation in treatment, alcohol consumption and drug abuse. Longitudinal datasets are increasingly available, particularly clinical data that contain multiple observations of health exposures and outcomes over time. Several analytic options are available for assessment of longitudinal data; however, it can be challenging to choose the appropriate analytic method for specific combinations of research questions and types of data. The purpose of this review is to help researchers choose the appropriate methods to analyze longitudinal data, using alcohol consumption as an example of a time-varying exposure variable. When selecting the optimal analytic method, one must consider aspects of exposure (e.g. timing, pattern, and amount) and outcome (fixed or time-varying), while also addressing minimizing bias. In this article, we will describe several analytic approaches for longitudinal data, including developmental trajectory analysis, generalized estimating equations, and mixed effect models. For each analytic strategy, we describe appropriate situations to use the method and provide an example that demonstrates the use of the method. Clinical data related to alcohol consumption and HIV are used to illustrate these methods.

Modelling the time-variant dietary exposure of PCBs in China over the period 1930 to 2100.

Science.gov (United States)

Zhao, Shizhen; Breivik, Knut; Jones, Kevin C; Sweetman, Andrew J

2018-06-06

This study aimed for the first time to reconstruct historical exposure profiles for PCBs to the Chinese population, by examining the combined effect of changing temporal emissions and dietary transition. A long-term (1930-2100) dynamic simulation of human exposure using realistic emission scenarios, including primary emissions, unintentional emissions and emissions from e-waste, combined with dietary transition trends was conducted by a multimedia fate model (BETR-Global) linked to a bioaccumulation model (ACC-HUMAN). The model predicted an approximate 30-year delay of peak body burden for PCB-153 in a 30-year-old Chinese female, compared to their European counterpart. This was mainly attributed to a combination of change in diet and divergent emission patterns in China. A fish-based diet was predicted to result in up to 8 times higher body burden than a vegetable-based diet (2010-2100). During the production period, a worst-case scenario assuming only consumption of imported food from a region with more extensive production and usage of PCBs would result in up to 4 times higher body burden compared to consumption of only locally produced food. However, such differences gradually diminished after cessation of production. Therefore, emission reductions in China alone may not be sufficient to protect human health for PCB-like chemicals, particularly during the period of mass production. The results from this study illustrate that human exposure is also likely to be dictated by inflows of PCBs via the environment, waste and food.

The Glycated Albumin (GA) to HbA1c Ratio Reflects Shorter-Term Glycemic Control than GA: Analysis of Patients with Fulminant Type 1 Diabetes.

Science.gov (United States)

Koga, Masafumi; Inada, Shinya; Nakao, Taisei; Kawamori, Ryuzo; Kasayama, Soji

2017-01-01

Glycated albumin (GA) reflects shorter-term glycemic control than HbA1c. We have reported that HbA1c is paradoxically increased in diabetic patients whose glycemic control deteriorated before ameliorating. In this study, we analyzed paradoxical increases of glycemic control indicators after treatment in patients with fulminant type 1 diabetes (FT1D). We also investigated whether the GA/HbA1c ratio may reflect shorter-term glycemic control than GA. Five FT1D patients whose post-treatment HbA1c and GA levels were measured were enrolled. We also used a formula to estimate HbA1c and GA from the fictitious models of changes in plasma glucose in FT1D patients. In this model, the periods during which HbA1c, GA, and the GA/HbA1c ratio were higher than at the first visit were compared. In addition, the half-life for the GA/HbA1c ratio was calculated in accordance with the half-lives for HbA1c and GA (36 and 14 days, respectively). In all FT1D patients, HbA1c levels 2-4 weeks after treatment were increased, with three patients (60%) experiencing an increase of GA levels. In contrast, an increase of the GA/HbA1c ratio was observed in only one patient. In all of the different models of changes in plasma glucose in FT1D patients, the length of time during which the values were higher than at the first visit was in the order of HbA1c > GA > GA/HbA1c ratio. The half-life for the GA/HbA1c ratio was 9 days, shorter than GA. These findings suggest that the GA/HbA1c ratio reflects shorter-term glycemic control than GA. © 2016 Wiley Periodicals, Inc.

Assessment of critical exposure and outcome windows in time-to-event analysis with application to air pollution and preterm birth study.

Science.gov (United States)

Chang, Howard H; Warren, Joshua L; Darrow, Lnydsey A; Reich, Brian J; Waller, Lance A

2015-07-01

In reproductive epidemiology, there is a growing interest to examine associations between air pollution exposure during pregnancy and the risk of preterm birth (PTB). One important research objective is to identify critical periods of exposure and estimate the associated effects at different stages of pregnancy. However, population studies have reported inconsistent findings. This may be due to limitations from the standard analytic approach of treating PTB as a binary outcome without considering time-varying exposures together over the course of pregnancy. To address this research gap, we present a Bayesian hierarchical model for conducting a comprehensive examination of gestational air pollution exposure by estimating the joint effects of weekly exposures during different vulnerable periods. Our model also treats PTB as a time-to-event outcome to address the challenge of different exposure lengths among ongoing pregnancies. The proposed model is applied to a dataset of geocoded birth records in the Atlanta metropolitan area between 1999-2005 to examine the risk of PTB associated with gestational exposure to ambient fine particulate matter [Formula: see text]m in aerodynamic diameter (PM[Formula: see text]). We find positive associations between PM[Formula: see text] exposure during early and mid-pregnancy, and evidence that associations are stronger for PTBs occurring around week 30. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Making tomorrow's mistakes today: Evolutionary prototyping for risk reduction and shorter development time

Science.gov (United States)

Friedman, Gary; Schwuttke, Ursula M.; Burliegh, Scott; Chow, Sanguan; Parlier, Randy; Lee, Lorrine; Castro, Henry; Gersbach, Jim

1993-01-01

In the early days of JPL's solar system exploration, each spacecraft mission required its own dedicated data system with all software applications written in the mainframe's native assembly language. Although these early telemetry processing systems were a triumph of engineering in their day, since that time the computer industry has advanced to the point where it is now advantageous to replace these systems with more modern technology. The Space Flight Operations Center (SFOC) Prototype group was established in 1985 as a workstation and software laboratory. The charter of the lab was to determine if it was possible to construct a multimission telemetry processing system using commercial, off-the-shelf computers that communicated via networks. The staff of the lab mirrored that of a typical skunk works operation -- a small, multi-disciplinary team with a great deal of autonomy that could get complex tasks done quickly. In an effort to determine which approaches would be useful, the prototype group experimented with all types of operating systems, inter-process communication mechanisms, network protocols, packet size parameters. Out of that pioneering work came the confidence that a multi-mission telemetry processing system could be built using high-level languages running in a heterogeneous, networked workstation environment. Experience revealed that the operating systems on all nodes should be similar (i.e., all VMS or all PC-DOS or all UNIX), and that a unique Data Transport Subsystem tool needed to be built to address the incompatibilities of network standards, byte ordering, and socket buffering. The advantages of building a telemetry processing system based on emerging industry standards were numerous: by employing these standards, we would no longer be locked into a single vendor. When new technology came to market which offered ten times the performance at one eighth the cost, it would be possible to attach the new machine to the network, re-compile the

Making tomorrow's mistakes today: Evolutionary prototyping for risk reduction and shorter development time

Science.gov (United States)

Friedman, Gary; Schwuttke, Ursula M.; Burliegh, Scott; Chow, Sanguan; Parlier, Randy; Lee, Lorrine; Castro, Henry; Gersbach, Jim

1993-03-01

In the early days of JPL's solar system exploration, each spacecraft mission required its own dedicated data system with all software applications written in the mainframe's native assembly language. Although these early telemetry processing systems were a triumph of engineering in their day, since that time the computer industry has advanced to the point where it is now advantageous to replace these systems with more modern technology. The Space Flight Operations Center (SFOC) Prototype group was established in 1985 as a workstation and software laboratory. The charter of the lab was to determine if it was possible to construct a multimission telemetry processing system using commercial, off-the-shelf computers that communicated via networks. The staff of the lab mirrored that of a typical skunk works operation -- a small, multi-disciplinary team with a great deal of autonomy that could get complex tasks done quickly. In an effort to determine which approaches would be useful, the prototype group experimented with all types of operating systems, inter-process communication mechanisms, network protocols, packet size parameters. Out of that pioneering work came the confidence that a multi-mission telemetry processing system could be built using high-level languages running in a heterogeneous, networked workstation environment. Experience revealed that the operating systems on all nodes should be similar (i.e., all VMS or all PC-DOS or all UNIX), and that a unique Data Transport Subsystem tool needed to be built to address the incompatibilities of network standards, byte ordering, and socket buffering. The advantages of building a telemetry processing system based on emerging industry standards were numerous: by employing these standards, we would no longer be locked into a single vendor. When new technology came to market which offered ten times the performance at one eighth the cost, it would be possible to attach the new machine to the network, re-compile the

The Impact of the Developmental Timing of Trauma Exposure on PTSD Symptoms and Psychosocial Functioning Among Older Adults

OpenAIRE

Ogle, Christin M.; Rubin, David C.; Siegler, Ilene C.

2013-01-01

The present study examined the impact of the developmental timing of trauma exposure on post-traumatic stress disorder (PTSD) symptoms and psychosocial functioning in a large sample of community-dwelling older adults (n = 1,995). Specifically, we investigated whether the negative consequences of exposure to traumatic events were greater for traumas experienced during childhood, adolescence, young adulthood, midlife, or older adulthood. Each of these developmental periods is characterized by a...

Bayesian Algorithm Implementation in a Real Time Exposure Assessment Model on Benzene with Calculation of Associated Cancer Risks

OpenAIRE

Sarigiannis, Dimosthenis A.; Karakitsios, Spyros P.; Gotti, Alberto; Papaloukas, Costas L.; Kassomenos, Pavlos A.; Pilidis, Georgios A.

2009-01-01

The objective of the current study was the development of a reliable modeling platform to calculate in real time the personal exposure and the associated health risk for filling station employees evaluating current environmental parameters (traffic, meteorological and amount of fuel traded) determined by the appropriate sensor network. A set of Artificial Neural Networks (ANNs) was developed to predict benzene exposure pattern for the filling station employees. Furthermore, a Physiology Based...

Time and frequency weightings and the assessment of sound exposure

DEFF Research Database (Denmark)

Ordoñez, Rodrigo Pizarro; de Toro, Miguel Angel Aranda; Hammershøi, Dorte

2010-01-01

Since the development of averaging/integrating sound level meters and frequency weighting networks in the 1950’s, measurement of the physical characteristics of sound has not changed a great deal. Advances have occurred in how the measured values are used (day-night averages, limit and action...... of the exposure. This information is being used to investigate metrics that can differentiate temporal characteristics (impulsive, fluctuating) as well as frequency characteristics (narrow-band or tonal dominance) of sound exposures. This presentation gives an overview of the existing sound measurement...... and analysis methods, that can provide a better representation of the effects of sound exposures on the hearing system...

Acute short-term dim light exposure can lower muscle strength endurance

OpenAIRE

Arnold G. Nelson; Joke Kokkonen; Megan Mickenberg

2015-01-01

Background: Since it has been shown that spending 18 h under dim light conditions can result in reduced handgrip endurance, it was questioned whether or not a shorter exposure to dim light (i.e., 1 h) would have similar influence upon muscular endurance. Therefore this study compared the number of weighted knee extension lifts that could be done after spending 1 h in either dim or bright light. Methods: Participants (5 women, 11 men, college students 19–26 years) performed knee extension l...

Association of mutations in the hemochromatosis gene with shorter life expectancy

DEFF Research Database (Denmark)

Bathum, L; Christiansen, L; Nybo, H

2001-01-01

BACKGROUND: To investigate whether the frequency of carriers of mutations in the HFE gene associated with hereditary hemochromatosis diminishes with age as an indication that HFE mutations are associated with increased mortality. It is of value in the debate concerning screening for hereditary...... hemochromatosis to determine the significance of heterozygosity. METHODS: Genotyping for mutations in exons 2 and 4 of the HFE gene using denaturing gradient gel electrophoresis in 1784 participants aged 45 to 100 years from 4 population-based studies: all 183 centenarians from the Danish Centenarian Study, 601...... in the distribution of mutations in exon 2 in the different age groups. CONCLUSIONS: In a high-carrier frequency population like Denmark, mutations in HFE show an age-related reduction in the frequency of heterozygotes for C282Y, which suggests that carrier status is associated with shorter life expectancy....

Environmental ozone exposure and oxidative DNA damage in adult residents of Florence, Italy

Energy Technology Data Exchange (ETDEWEB)

Palli, Domenico, E-mail: d.palli@ispo.toscana.i [Molecular and Nutritional Epidemiology Unit, Cancer Prevention and Research Institute (ISPO), Via Cosimo il Vecchio 2, 50139 Florence (Italy); Sera, Francesco, E-mail: f.sera@ispo.toscana.i [Molecular and Nutritional Epidemiology Unit, Cancer Prevention and Research Institute (ISPO), Via Cosimo il Vecchio 2, 50139 Florence (Italy); Giovannelli, Lisa, E-mail: lisag@pharm.unifi.i [Department of Pharmacology, University of Florence, Viale G.Pieraccini 6, 50139 Florence (Italy); Masala, Giovanna, E-mail: g.masala@ispo.toscana.i [Molecular and Nutritional Epidemiology Unit, Cancer Prevention and Research Institute (ISPO), Via Cosimo il Vecchio 2, 50139 Florence (Italy); Grechi, Daniele [Regional Environmental Protection Agency of Tuscany (ARPAT), Via Porpora 22, 50144 Florence (Italy); Bendinelli, Benedetta, E-mail: b.bendinelli@ispo.toscana.i [Molecular and Nutritional Epidemiology Unit, Cancer Prevention and Research Institute (ISPO), Via Cosimo il Vecchio 2, 50139 Florence (Italy); Caini, Saverio, E-mail: s.caini@ispo.toscana.i [Molecular and Nutritional Epidemiology Unit, Cancer Prevention and Research Institute (ISPO), Via Cosimo il Vecchio 2, 50139 Florence (Italy); Dolara, Piero, E-mail: piero.dolara@unifi.i [Department of Pharmacology, University of Florence, Viale G.Pieraccini 6, 50139 Florence (Italy); Saieva, Calogero, E-mail: c.saieva@ispo.toscana.i [Molecular and Nutritional Epidemiology Unit, Cancer Prevention and Research Institute (ISPO), Via Cosimo il Vecchio 2, 50139 Florence (Italy)

2009-05-15

In 71 adults residing in Florence, Italy, enrolled in a prospective study, we investigated the correlation between individual levels of oxidative DNA damage detected by the Comet assay in circulating lymphocytes, and a specific ozone exposure score calculated in 10 different time-windows (0-5 to 0-90 days) before blood drawing, based on daily measurements provided by the local environmental monitoring system. Overall, statistically significant positive correlations between average ozone concentrations and DNA damage emerged in almost all time-windows considered; correlations were more evident among males, non-smokers, and traffic-exposed workers. Multivariate regression analyses taking into account selected individual characteristics, showed an independent effect on DNA damage of average ozone concentrations in the last 60-90 days before blood drawing. Local residents showed a divergent pattern with correlations restricted to shorter time-windows. Our results suggest that ozone concentrations at ground levels modulate oxidative DNA damage in circulating lymphocytes of residents of polluted areas. - Ozone concentrations over the 60-90 days before blood drawing correlated with DNA damage in circulating lymphocytes of adults living in the metropolitan area of Florence, Italy.

Environmental ozone exposure and oxidative DNA damage in adult residents of Florence, Italy

International Nuclear Information System (INIS)

Palli, Domenico; Sera, Francesco; Giovannelli, Lisa; Masala, Giovanna; Grechi, Daniele; Bendinelli, Benedetta; Caini, Saverio; Dolara, Piero; Saieva, Calogero

2009-01-01

In 71 adults residing in Florence, Italy, enrolled in a prospective study, we investigated the correlation between individual levels of oxidative DNA damage detected by the Comet assay in circulating lymphocytes, and a specific ozone exposure score calculated in 10 different time-windows (0-5 to 0-90 days) before blood drawing, based on daily measurements provided by the local environmental monitoring system. Overall, statistically significant positive correlations between average ozone concentrations and DNA damage emerged in almost all time-windows considered; correlations were more evident among males, non-smokers, and traffic-exposed workers. Multivariate regression analyses taking into account selected individual characteristics, showed an independent effect on DNA damage of average ozone concentrations in the last 60-90 days before blood drawing. Local residents showed a divergent pattern with correlations restricted to shorter time-windows. Our results suggest that ozone concentrations at ground levels modulate oxidative DNA damage in circulating lymphocytes of residents of polluted areas. - Ozone concentrations over the 60-90 days before blood drawing correlated with DNA damage in circulating lymphocytes of adults living in the metropolitan area of Florence, Italy.

A prototype catheter designed for ultraviolet C disinfection

DEFF Research Database (Denmark)

Bak, Jimmy; Begovic, Tanja

2013-01-01

UVC light exposure, sampling and plate counting. Findings Two minutes of UVC exposure was sufficient to obtain 4 log10 disinfection for the full-length prototype catheter. This exposure corresponds to ∼40 mJ/cm2 at the catheter tip and indicates that even shorter exposure times can be achieved...

GPS-based microenvironment tracker (MicroTrac) model to estimate time-location of individuals for air pollution exposure assessments: model evaluation in central North Carolina.

Science.gov (United States)

Breen, Michael S; Long, Thomas C; Schultz, Bradley D; Crooks, James; Breen, Miyuki; Langstaff, John E; Isaacs, Kristin K; Tan, Yu-Mei; Williams, Ronald W; Cao, Ye; Geller, Andrew M; Devlin, Robert B; Batterman, Stuart A; Buckley, Timothy J

2014-07-01

A critical aspect of air pollution exposure assessment is the estimation of the time spent by individuals in various microenvironments (ME). Accounting for the time spent in different ME with different pollutant concentrations can reduce exposure misclassifications, while failure to do so can add uncertainty and bias to risk estimates. In this study, a classification model, called MicroTrac, was developed to estimate time of day and duration spent in eight ME (indoors and outdoors at home, work, school; inside vehicles; other locations) from global positioning system (GPS) data and geocoded building boundaries. Based on a panel study, MicroTrac estimates were compared with 24-h diary data from nine participants, with corresponding GPS data and building boundaries of home, school, and work. MicroTrac correctly classified the ME for 99.5% of the daily time spent by the participants. The capability of MicroTrac could help to reduce the time-location uncertainty in air pollution exposure models and exposure metrics for individuals in health studies.

Estimating Benzene Exposure Level over Time and by Industry Type through a Review of Literature on Korea

Directory of Open Access Journals (Sweden)

Donguk Park

2015-09-01

Full Text Available The major purpose of this study is to construct a retrospective exposure assessment for benzene through a review of literature on Korea. Airborne benzene measurements reported in 34 articles were reviewed. A total of 15,729 individual measurements were compiled. Weighted arithmetic means [AM(w] and their variance calculated across studies were summarized according to 5-year period intervals (prior to the 1970s through the 2010s and industry type. Industries were classified according to Korea Standard Industrial Classification (KSIC using information provided in the literature. We estimated quantitative retrospective exposure to benzene for each cell in the matrix through a combination of time and KSIC. Analysis of the AM(w indicated reductions in exposure levels over time, regardless of industry, with mean levels prior to the 1980–1984 period of 50.4 ppm (n = 2,289, which dropped to 2.8 ppm (n = 305 in the 1990–1994 period, and to 0.1 ppm (n = 294 in the 1995–1999 period. There has been no improvement since the 2000s, when the AM(w of 4.3 ppm (n = 6,211 for the 2005–2009 period and 4.5 ppm (n = 3,358 for the 2010–2013 period were estimated. A comparison by industry found no consistent patterns in the measurement results. Our estimated benzene measurements can be used to determine not only the possibility of retrospective exposure to benzene, but also to estimate the level of quantitative or semiquantitative retrospective exposure to benzene.

GPS-based Microenvironment Tracker (MicroTrac) Model to Estimate Time-Location of Individuals for Air Pollution Exposure Assessments: Model Evaluation in Central North Carolina

Science.gov (United States)

A critical aspect of air pollution exposure assessment is the estimation of the time spent by individuals in various microenvironments (ME). Accounting for the time spent in different ME with different pollutant concentrations can reduce exposure misclassifications, while failure...

Is equity confined to the shorter term projects - and if not, what does it need?

International Nuclear Information System (INIS)

Cryan, T.

1996-01-01

There are two types of equity investor generally found in shorter term energy projects: energy project developers or sponsors who view a given project as buying or building a business; and financial investors who have viewed an investment as buying a stream of cash flows. This article examines the objectives and needs of these two investor groups, and discusses the principal issues which govern their respective decision-making process. (author)

Night-Time Decibel Hell: Mapping Noise Exposure Zones and Individual Annoyance Ratings in an Urban Environment in Ghana

Directory of Open Access Journals (Sweden)

Rachel N. Zakpala

2014-01-01

Full Text Available Although accumulating evidence over the past thirty years indicates that noise is an environmental stressor in residential settings, much of the data emanated from studies in high-intensity, noise impact zones around airports or major roads. Little is known about religious noise, especially at night, which is increasingly a growing concern for both the general public and policy-makers in sub-Saharan Africa. Using geographical information systems (GIS, this study measured and mapped exposure to religious noise in a rapidly urbanising municipality in Ghana. Quantitative noise risk assessment was used to evaluate the risk of religious noise-induced hearing loss to residents in the exposed neighbourhoods. The results show that all neighbourhoods where churches were situated had at least one location with significant risk of noise-induced hearing loss. However, there was no statistically significant relationship between neighbourhoods where religious noise exposure was the highest and where noise annoyance was the highest. The magnitude of the noise values for night-time exposure is remarkable particularly given that excessive night-time noise exposure has the greatest detrimental effect on public health. There is the need to focus on vulnerable groups, sensitive hours of the night, and possible confounding with air pollution in order to wholly address this potential hazard.

Defining Accelerometer Nonwear Time to Maximize Detection of Sedentary Time in Youth

DEFF Research Database (Denmark)

Cain, Kelli L; Bonilla, Edith; Conway, Terry L

2018-01-01

PURPOSE: The present study examined various accelerometer nonwear definitions and their impact on detection of sedentary time using different ActiGraph models, filters, and axes. METHODS: In total, 61 youth (34 children and 27 adolescents; aged 5-17 y) wore a 7164 and GT3X+ ActiGraph on a hip......), and GT3X+N (V and VM), and sedentary estimates were computed. RESULTS: The GT3X+LFE-VM was most sensitive to movement and could accurately detect observed sedentary time with the shortest nonwear definition of 20 minutes of consecutive "0" counts for children and 40 minutes for adolescents. The GT3X......+N-V was least sensitive to movement and required longer definitions to detect observed sedentary time (40 min for children and 90 min for adolescents). VM definitions were 10 minutes shorter than V definitions. LFE definitions were 40 minutes shorter than N definitions in adolescents. CONCLUSION: Different...

Reactive oxygen species levels and DNA fragmentation on astrocytes in primary culture after acute exposure to low intensity microwave electromagnetic field.

Science.gov (United States)

Campisi, Agata; Gulino, Marisa; Acquaviva, Rosaria; Bellia, Paolo; Raciti, Giuseppina; Grasso, Rosaria; Musumeci, Francesco; Vanella, Angelo; Triglia, Antonio

2010-03-31

The exposure of primary rat neocortical astroglial cell cultures to acute electromagnetic fields (EMF) in the microwave range was studied. Differentiated astroglial cell cultures at 14 days in vitro were exposed for 5, 10, or 20min to either 900MHz continuous waves or 900MHz waves modulated in amplitude at 50Hz using a sinusoidal waveform and 100% modulation index. The strength of the electric field (rms value) at the sample position was 10V/m. No change in cellular viability evaluated by MTT test and lactate dehydrogenase release was observed. A significant increase in ROS levels and DNA fragmentation was found only after exposure of the astrocytes to modulated EMF for 20min. No evident effects were detected when shorter time intervals or continuous waves were used. The irradiation conditions allowed the exclusion of any possible thermal effect. Our data demonstrate, for the first time, that even acute exposure to low intensity EMF induces ROS production and DNA fragmentation in astrocytes in primary cultures, which also represent the principal target of modulated EMF. Our findings also suggest the hypothesis that the effects could be due to hyperstimulation of the glutamate receptors, which play a crucial role in acute and chronic brain damage. Furthermore, the results show the importance of the amplitude modulation in the interaction between EMF and neocortical astrocytes. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

The Toxic Exposure Surveillance System (TESS): Risk assessment and real-time toxicovigilance across United States poison centers

International Nuclear Information System (INIS)

Watson, William A.; Litovitz, Toby L.; Belson, Martin G.; Funk Wolkin, Amy B.; Patel, Manish; Schier, Joshua G.; Reid, Nicole E.; Kilbourne, Edwin; Rubin, Carol

2005-01-01

The Toxic Exposure Surveillance System (TESS) is a uniform data set of US poison centers cases. Categories of information include the patient, the caller, the exposure, the substance(s), clinical toxicity, treatment, and medical outcome. The TESS database was initiated in 1985, and provides a baseline of more than 36.2 million cases through 2003. The database has been utilized for a number of safety evaluations. Consideration of the strengths and limitations of TESS data must be incorporated into data interpretation. Real-time toxicovigilance was initiated in 2003 with continuous uploading of new cases from all poison centers to a central database. Real-time toxicovigilance utilizing general and specific approaches is systematically run against TESS, further increasing the potential utility of poison center experiences as a means of early identification of potential public health threats

The Toxic Exposure Surveillance System (TESS): risk assessment and real-time toxicovigilance across United States poison centers.

Science.gov (United States)

Watson, William A; Litovitz, Toby L; Belson, Martin G; Wolkin, Amy B Funk; Patel, Manish; Schier, Joshua G; Reid, Nicole E; Kilbourne, Edwin; Rubin, Carol

2005-09-01

The Toxic Exposure Surveillance System (TESS) is a uniform data set of US poison centers cases. Categories of information include the patient, the caller, the exposure, the substance(s), clinical toxicity, treatment, and medical outcome. The TESS database was initiated in 1985, and provides a baseline of more than 36.2 million cases through 2003. The database has been utilized for a number of safety evaluations. Consideration of the strengths and limitations of TESS data must be incorporated into data interpretation. Real-time toxicovigilance was initiated in 2003 with continuous uploading of new cases from all poison centers to a central database. Real-time toxicovigilance utilizing general and specific approaches is systematically run against TESS, further increasing the potential utility of poison center experiences as a means of early identification of potential public health threats.

Timing of in utero malaria exposure influences fetal CD4 T cell regulatory versus effector differentiation

Directory of Open Access Journals (Sweden)

Mary Prahl

2016-10-01

Full Text Available Abstract Background In malaria-endemic areas, the first exposure to malaria antigens often occurs in utero when the fetal immune system is poised towards the development of tolerance. Children exposed to placental malaria have an increased risk of clinical malaria in the first few years of life compared to unexposed children. Recent work has suggested the potential of pregnancy-associated malaria to induce immune tolerance in children living in malaria-endemic areas. A study was completed to evaluate the effect of malaria exposure during pregnancy on fetal immune tolerance and effector responses. Methods Using cord blood samples from a cohort of mother-infant pairs followed from early in pregnancy until delivery, flow cytometry analysis was completed to assess the relationship between pregnancy-associated malaria and fetal cord blood CD4 and dendritic cell phenotypes. Results Cord blood FoxP3+ Treg counts were higher in infants born to mothers with Plasmodium parasitaemia early in pregnancy (12–20 weeks of gestation; p = 0.048, but there was no association between Treg counts and the presence of parasites in the placenta at the time of delivery (by loop-mediated isothermal amplification (LAMP; p = 0.810. In contrast, higher frequencies of activated CD4 T cells (CD25+FoxP3−CD127+ were observed in the cord blood of neonates with active placental Plasmodium infection at the time of delivery (p = 0.035. This population exhibited evidence of effector memory differentiation, suggesting priming of effector T cells in utero. Lastly, myeloid dendritic cells were higher in the cord blood of infants with histopathologic evidence of placental malaria (p < 0.0001. Conclusion Together, these data indicate that in utero exposure to malaria drives expansion of both regulatory and effector T cells in the fetus, and that the timing of this exposure has a pivotal role in determining the polarization of the fetal immune response.

Are Shorter Versions of the Positive and Negative Syndrome Scale (PANSS) Doable? A Critical Review.

Science.gov (United States)

Lindenmayer, Jean-Pierre

2017-12-01

The Positive and Negative Syndrome Scale (PANSS) is a well-established assessment tool for measuring symptom severity in schizophrenia. Researchers and clinicians have been interested in the development of a short version of the PANSS that could reduce the burden of its administration for patients and raters. The author presents a comprehensive overview of existing brief PANSS measures, including their strengths and limitations, and discusses some possible next steps. There are two available scales that offer a reduced number of original PANSS items: PANSS-14 and PANSS-19; and two shorter versions that include six items: Brief PANSS and PANSS-6. The PANSS-6 has been tested quite extensively in established trials and appears to demonstrate high sensitivity to change and an established cut off definition for remission. Prospective testing in new antipsychotic treatment trials is still required for these shorter versions of PANSS. In addition, they need to be supplemented with interview guides, as well as provide conversion formulas to translate total scores from the short PANSS versions to the PANSS-30. Both short versions of the PANSS are essentially designed to evaluate response to antipsychotic treatment. Future PANSS scale development needs to address specific measurement of treatment-responsive positive symptoms by including treatment-sensitive items, as well as illness-phase specific PANSS tools.

Instrumental variables estimation of exposure effects on a time-to-event endpoint using structural cumulative survival models.

Science.gov (United States)

Martinussen, Torben; Vansteelandt, Stijn; Tchetgen Tchetgen, Eric J; Zucker, David M

2017-12-01

The use of instrumental variables for estimating the effect of an exposure on an outcome is popular in econometrics, and increasingly so in epidemiology. This increasing popularity may be attributed to the natural occurrence of instrumental variables in observational studies that incorporate elements of randomization, either by design or by nature (e.g., random inheritance of genes). Instrumental variables estimation of exposure effects is well established for continuous outcomes and to some extent for binary outcomes. It is, however, largely lacking for time-to-event outcomes because of complications due to censoring and survivorship bias. In this article, we make a novel proposal under a class of structural cumulative survival models which parameterize time-varying effects of a point exposure directly on the scale of the survival function; these models are essentially equivalent with a semi-parametric variant of the instrumental variables additive hazards model. We propose a class of recursive instrumental variable estimators for these exposure effects, and derive their large sample properties along with inferential tools. We examine the performance of the proposed method in simulation studies and illustrate it in a Mendelian randomization study to evaluate the effect of diabetes on mortality using data from the Health and Retirement Study. We further use the proposed method to investigate potential benefit from breast cancer screening on subsequent breast cancer mortality based on the HIP-study. © 2017, The International Biometric Society.

Early adolescent boys’ exposure to Internet pornography: relationships to pubertal timing, sensation seeking, and academic performance

NARCIS (Netherlands)

Beyens, I.; Vandenbosch, L.; Eggermont, S.

2015-01-01

Research has demonstrated that adolescents regularly use Internet pornography. This two-wave panel study aimed to test an integrative model in early adolescent boys (Mage = 14.10; N = 325) that (a) explains their exposure to Internet pornography by looking at relationships with pubertal timing and

Accumulative effects of indoor air pollution exposure on leukocyte telomere length among non-smokers.

Science.gov (United States)

Lin, Nan; Mu, Xinlin; Wang, Guilian; Ren, Yu'ang; Su, Shu; Li, Zhiwen; Wang, Bin; Tao, Shu

2017-08-01

Indoor air pollution is an important environmental factor that contributes to the burden of various diseases. Long-term exposure to ambient air pollution is associated with telomere shortening. However, the association between chronic indoor air pollution from household fuel combustion and leukocyte telomere length has not been studied. In our study, 137 cancer-free non-smokers were recruited. Their exposure levels to indoor air pollution from 1985 to 2014 were assessed using a face-to-face interview questionnaire, and leukocyte telomere length (LTL) was measured using a monochrome multiplex quantitative PCR method. Accumulative exposure to solid fuel usage for cooking was negatively correlated with LTL. The LTL of residents who were exposed to solid fuel combustion for three decades (LTL = 0.70 ± 0.17) was significantly shorter than that of other populations. In addition, education and occupation were related to both exposure to solid fuel and LTL. Sociodemographic factors may play a mediating role in the correlation between leukocyte telomere length and environmental exposure to indoor air pollution. In conclusion, long-term exposure to indoor air pollution may cause LTL dysfunction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Prenatal Phthalate Exposures and Anogenital Distance in Swedish Boys

Science.gov (United States)

Carlstedt, Fredrik; Jönsson, Bo AG.; Lindh, Christian H.; Jensen, Tina K.; Bodin, Anna; Jonsson, Carin; Janson, Staffan; Swan, Shanna H.

2014-01-01

Background: Phthalates are used as plasticizers in soft polyvinyl chloride (PVC) and in a large number of consumer products. Because of reported health risks, diisononyl phthalate (DiNP) has been introduced as a replacement for di(2-ethylhexyl) phthalate (DEHP) in soft PVC. This raises concerns because animal data suggest that DiNP may have antiandrogenic properties similar to those of DEHP. The anogenital distance (AGD)—the distance from the anus to the genitals—has been used to assess reproductive toxicity. Objective: The objective of this study was to examine the associations between prenatal phthalate exposure and AGD in Swedish infants. Methods: AGD was measured in 196 boys at 21 months of age, and first-trimester urine was analyzed for 10 phthalate metabolites of DEP (diethyl phthalate), DBP (dibutyl phthalate), DEHP, BBzP (benzylbutyl phthalate), as well as DiNP and creatinine. Data on covariates were collected by questionnaires. Results: The most significant associations were found between the shorter of two AGD measures (anoscrotal distance; AGDas) and DiNP metabolites and strongest for oh-MMeOP [mono-(4-methyl-7-hydroxyloctyl) phthalate] and oxo-MMeOP [mono-(2-ethyl-5-oxohexyl) phthalate]. However, the AGDas reduction was small (4%) in relation to more than an interquartile range increase in DiNP exposure. Conclusions: These findings call into question the safety of substituting DiNP for DEHP in soft PVC, particularly because a shorter male AGD has been shown to relate to male genital birth defects in children and impaired reproductive function in adult males and the fact that human levels of DiNP are increasing globally. Citation: Bornehag CG, Carlstedt F, Jönsson BA, Lindh CH, Jensen TK, Bodin A, Jonsson C, Janson S, Swan SH. 2015. Prenatal phthalate exposures and anogenital distance in Swedish boys. Environ Health Perspect 123:101–107; http://dx.doi.org/10.1289/ehp.1408163 PMID:25353625

Long-term exposure to mobile communication radiation: An analysis of time-variability of electric field level in GSM900 down-link channels

International Nuclear Information System (INIS)

Miclaus, S.; Bechet, P.; Gheorghevici, M.

2013-01-01

Interest for knowing long-term human exposure levels due to mobile communications has increased in the last years. It has been shown that short-term exposure assessment made under standard procedural restrictions is not reliable when it comes to conclusions on long-term exposure levels. The present work is the result of a several week analysis of time variability of electric field level inside traffic and control channels of the GSM900 mobile communication down-link band and it indicates that a temporal model to allow future predictions of exposure on the long run is obtainable. Collecting, processing and statistically analysing the data provide expression of the maximum and weighted field strengths and their evolution in time. Specific electromagnetic footprints of the channels have been extracted, differentiations between their characteristics have been emphasised and practical advice is provided, with the scope of contributing to the development of reliable procedures for long-term exposure assessment. (authors)

The relationship between amygdala activation and passive exposure time to an aversive cue during a continuous performance task.

Directory of Open Access Journals (Sweden)

Irina A Strigo

2010-11-01

Full Text Available The allocation of attention modulates negative emotional processing in the amygdala. However, the role of passive exposure time to emotional signals in the modulation of amygdala activity during active task performance has not been examined. In two functional Magnetic Resonance Imaging (fMRI experiments conducted in two different groups of healthy human subjects, we examined activation in the amygdala due to cued anticipation of painful stimuli while subjects performed a simple continuous performance task (CPT with either a fixed or a parametrically varied trial duration. In the first experiment (N = 16, engagement in the CPT during a task with fixed trial duration produced the expected attenuation of amygdala activation, but close analysis suggested that the attenuation occurred during the period of active engagement in CPT, and that amygdala activity increased proportionately during the remainder of each trial, when subjects were passively exposed to the pain cue. In the second experiment (N = 12, the duration of each trial was parametrically varied, and we found that amygdala activation was linearly related to the time of passive exposure to the anticipatory cue. We suggest that amygdala activation during negative anticipatory processing depends directly on the passive exposure time to the negative cue.

Chronic Low Dose Rate Ionizing Radiation Exposure Induces Premature Senescence in Human Fibroblasts that Correlates with Up Regulation of Proteins Involved in Protection against Oxidative Stress

Directory of Open Access Journals (Sweden)

Olga Loseva

2014-07-01

Full Text Available The risks of non-cancerous diseases associated with exposure to low doses of radiation are at present not validated by epidemiological data, and pose a great challenge to the scientific community of radiation protection research. Here, we show that premature senescence is induced in human fibroblasts when exposed to chronic low dose rate (LDR exposure (5 or 15 mGy/h of gamma rays from a 137Cs source. Using a proteomic approach we determined differentially expressed proteins in cells after chronic LDR radiation compared to control cells. We identified numerous proteins involved in protection against oxidative stress, suggesting that these pathways protect against premature senescence. In order to further study the role of oxidative stress for radiation induced premature senescence, we also used human fibroblasts, isolated from a patient with a congenital deficiency in glutathione synthetase (GS. We found that these GS deficient cells entered premature senescence after a significantly shorter time of chronic LDR exposure as compared to the GS proficient cells. In conclusion, we show that chronic LDR exposure induces premature senescence in human fibroblasts, and propose that a stress induced increase in reactive oxygen species (ROS is mechanistically involved.

Cumulative effects of heat exposure and storage conditions of Oxytocin-in-Uniject in rural Ghana: implications for scale up.

Science.gov (United States)

Mullany, Luke C; Newton, Sam; Afari-Asiedu, Samuel; Adiibokah, Edward; Agyemang, Charlotte T; Cofie, Patience; Brooke, Steve; Owusu-Agyei, Seth; Stanton, Cynthia K

2014-08-01

Postpartum hemorrhage can be reduced substantially in home deliveries attended by community-based workers by using Oxytocin-in-Uniject (OIU) devices affixed with temperature-time indicators. We characterized the distribution of time to discard of these devices when stored under normal field conditions in Ghana. Two drug storage simulation studies were conducted in rural Ghana in 2011 and 2012. Devices were transported under refrigeration from manufacture (Argentina) to storage at the study site. Twenty-three field workers each stored at home (unrefrigerated) 25 OIU devices and monitored them daily to record: (1) time to transition from usable to unusable, and (2) continuous digital ambient temperature to determine heat exposure over the simulation period. Time to discard was estimated and compared with mean kinetic temperature exposure of the devices during the shipment and storage phases and with characteristics of the storage locations using Weibull regression models. We used the time to discard distributions in a Monte Carlo simulation to estimate wastage rates in a hypothetical program setting. Time for shipment and transfer to long-term refrigerated storage and mean kinetic temperature during the shipment phase was 8.6 days/10.3°C and 13.4 days/12.1°C, for the first and second simulation studies, respectively. Median (range) time to discard when stored under field conditions (unrefrigerated) was 43 (6 to 59) days and 33 (14 to 50) days, respectively. Mean time to discard was 10.0 days shorter in the second simulation, during which mean kinetic temperature exposure was 3.9°C higher. Simulating a monthly distribution system and assuming typical usage, predicted wastage of product was less than 10%. The time to discard of devices was highly sensitive to small changes in temperature exposure. Under field conditions typical in rural Ghana, OIU packages will have a half-life of approximately 30 to 40 days based on the temperature monitor used during the study

Quantifying risk over the life course - latency, age-related susceptibility, and other time-varying exposure metrics.

Science.gov (United States)

Wang, Molin; Liao, Xiaomei; Laden, Francine; Spiegelman, Donna

2016-06-15

Identification of the latency period and age-related susceptibility, if any, is an important aspect of assessing risks of environmental, nutritional, and occupational exposures. We consider estimation and inference for latency and age-related susceptibility in relative risk and excess risk models. We focus on likelihood-based methods for point and interval estimation of the latency period and age-related windows of susceptibility coupled with several commonly considered exposure metrics. The method is illustrated in a study of the timing of the effects of constituents of air pollution on mortality in the Nurses' Health Study. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

A Perceptual Pathway to Bias: Interracial Exposure Reduces Abrupt Shifts in Real-Time Race Perception That Predict Mixed-Race Bias.

Science.gov (United States)

Freeman, Jonathan B; Pauker, Kristin; Sanchez, Diana T

2016-04-01

In two national samples, we examined the influence of interracial exposure in one's local environment on the dynamic process underlying race perception and its evaluative consequences. Using a mouse-tracking paradigm, we found in Study 1 that White individuals with low interracial exposure exhibited a unique effect of abrupt, unstable White-Black category shifting during real-time perception of mixed-race faces, consistent with predictions from a neural-dynamic model of social categorization and computational simulations. In Study 2, this shifting effect was replicated and shown to predict a trust bias against mixed-race individuals and to mediate the effect of low interracial exposure on that trust bias. Taken together, the findings demonstrate that interracial exposure shapes the dynamics through which racial categories activate and resolve during real-time perceptions, and these initial perceptual dynamics, in turn, may help drive evaluative biases against mixed-race individuals. Thus, lower-level perceptual aspects of encounters with racial ambiguity may serve as a foundation for mixed-race prejudice. © The Author(s) 2016.

Time to Guide: Evidence for Delayed Attentional Guidance in Contextual Cueing.

Science.gov (United States)

Kunar, Melina A; Flusberg, Stephen J; Wolfe, Jeremy M

2008-01-01

Contextual cueing experiments show that, when displays are repeated, reaction times (RTs) to find a target decrease over time even when the observers are not aware of the repetition. Recent evidence suggests that this benefit in standard contextual cueing tasks is not likely to be due to an improvement in attentional guidance (Kunar, Flusberg, Horowitz & Wolfe, 2007). Nevertheless, we ask whether guidance can help participants find the target in a repeated display, if they are given sufficient time to encode the display. In Experiment 1 we increased the display complexity so that it took participants longer to find the target. Here we found a larger effect of guidance than in a condition with shorter RTs. Experiment 2 gave participants prior exposure to the display context. The data again showed that with more time participants could implement guidance to help find the target, provided that there was something in the search stimuli locations to guide attention to. The data suggest that although the benefit in a standard contextual cueing task is unlikely to be a result of guidance, guidance can play a role if it is given time to develop.

Factors influencing time-location patterns and their impact on estimates of exposure: the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air).

Science.gov (United States)

Spalt, Elizabeth W; Curl, Cynthia L; Allen, Ryan W; Cohen, Martin; Williams, Kayleen; Hirsch, Jana A; Adar, Sara D; Kaufman, Joel D

2016-06-01

We assessed time-location patterns and the role of individual- and residential-level characteristics on these patterns within the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air) cohort and also investigated the impact of individual-level time-location patterns on individual-level estimates of exposure to outdoor air pollution. Reported time-location patterns varied significantly by demographic factors such as age, gender, race/ethnicity, income, education, and employment status. On average, Chinese participants reported spending significantly more time indoors and less time outdoors and in transit than White, Black, or Hispanic participants. Using a tiered linear regression approach, we predicted time indoors at home and total time indoors. Our model, developed using forward-selection procedures, explained 43% of the variability in time spent indoors at home, and incorporated demographic, health, lifestyle, and built environment factors. Time-weighted air pollution predictions calculated using recommended time indoors from USEPA overestimated exposures as compared with predictions made with MESA Air participant-specific information. These data fill an important gap in the literature by describing the impact of individual and residential characteristics on time-location patterns and by demonstrating the impact of population-specific data on exposure estimates.

Low-level arsenic exposure via drinking water consumption and female fecundity - A preliminary investigation

Energy Technology Data Exchange (ETDEWEB)

Susko, Michele L. [Department of Epidemiology and Biostatistics, University at Albany, State University of New York, Rensselaer, New York (United States); Bloom, Michael S., E-mail: mbloom@albany.edu [Department of Epidemiology and Biostatistics, University at Albany, State University of New York, Rensselaer, New York (United States); Department of Environmental Health Sciences, University at Albany, State University of New York, Rensselaer, New York (United States); Neamtiu, Iulia A. [Health Department, Environmental Health Center, Cluj-Napoca (Romania); IMOGEN Research Institute, Cluj-Napoca (Romania); Appleton, Allison A. [Department of Epidemiology and Biostatistics, University at Albany, State University of New York, Rensselaer, New York (United States); Surdu, Simona [Department of Environmental Health Sciences, University at Albany, State University of New York, Rensselaer, New York (United States); Pop, Cristian [Physico-chemical and Biotoxicological Analysis Laboratory, Environmental Health Center, Cluj-Napoca (Romania); Cluj School of Public Health - College of Political, Administrative and Communication Sciences, Babeș-Bolyai University, Cluj-Napoca (Romania); Faculty of Environmental Science and Engineering, Babeș-Bolyai University, Cluj-Napoca (Romania); Fitzgerald, Edward F. [Department of Epidemiology and Biostatistics, University at Albany, State University of New York, Rensselaer, New York (United States); Department of Environmental Health Sciences, University at Albany, State University of New York, Rensselaer, New York (United States); Anastasiu, Doru [University of Medicine and Pharmacy “Victor Babeș”, Timișoara (Romania); Obstetrics and Gynecology Department of the Emergency County Hospital, Timișoara (Romania); and others

2017-04-15

High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timiá¹£ County, Romania. Women (n=94) with planned pregnancies of 5–20 weeks gestation completed a comprehensive physician-administered study questionnaire and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women. For example, 1 µg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P=0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study. - Highlights: • We assessed low level drinking water arsenic as a predictor of fecundability. • Arsenic did

Low-level arsenic exposure via drinking water consumption and female fecundity - A preliminary investigation

International Nuclear Information System (INIS)

Susko, Michele L.; Bloom, Michael S.; Neamtiu, Iulia A.; Appleton, Allison A.; Surdu, Simona; Pop, Cristian; Fitzgerald, Edward F.; Anastasiu, Doru

2017-01-01

High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timiá¹£ County, Romania. Women (n=94) with planned pregnancies of 5–20 weeks gestation completed a comprehensive physician-administered study questionnaire and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women. For example, 1 µg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P=0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study. - Highlights: • We assessed low level drinking water arsenic as a predictor of fecundability. • Arsenic did

Devulcanization of ground tire rubber: Physical and chemical changes after different microwave exposure times

Directory of Open Access Journals (Sweden)

P. S. Garcia

2015-11-01

Full Text Available Microwave devulcanization is known to be a promising and an efficient rubber recycling method which makes possible for the rubber to regain its fluidity, and makes it capable of being remolded and revulcanized. The focus of this work is to understand the physical and chemical changes that occur in the ground tire rubber after different microwave exposure periods. For this purpose chemical, thermal, rheological and morphological analyses were performed on the tire rubber, which contains natural rubber (NR and styrene-butadiene rubber (SBR as polymeric material. The results showed that the microwave treatment promoted the breaking of sulfur cross-links and consequently increased the rubber fluidity. However, long periods of exposure led to degradation and modification of some properties. At nanoscale, the deformation of the devulcanized NR domain under stress was observed, and the morphology obtained appears to be a droplet dispersion morphology. The most exposed samples presented only one glass transition temperature, and from this it was concluded that the treatment may have played an important role in the compatibilization of the elastomeric blend. Based on the results, it is required to control the microwave exposure time and polymeric degradation in order to achieve a regenerated rubber with satisfactory properties.

Time to reach tacrolimus maximum blood concentration,mean residence time, and acute renal allograft rejection: an open-label, prospective, pharmacokinetic study in adult recipients.

Science.gov (United States)

Kuypers, Dirk R J; Vanrenterghem, Yves

2004-11-01

The aims of this study were to determine whether disposition-related pharmacokinetic parameters such as T(max) and mean residence time (MRT) could be used as predictors of clinical efficacy of tacrolimus in renal transplant recipients, and to what extent these parameters would be influenced by clinical variables. We previously demonstrated, in a prospective pharmacokinetic study in de novo renal allograft recipients, that patients who experienced early acute rejection did not differ from patients free from rejection in terms of tacrolimus pharmacokinetic exposure parameters (dose interval AUC, preadministration trough blood concentration, C(max), dose). However, recipients with acute rejection reached mean (SD) tacrolimus T(max) significantly faster than those who were free from rejection (0.96 [0.56] hour vs 1.77 [1.06] hours; P clearance nor T(1/2) could explain this unusual finding, we used data from the previous study to calculate MRT from the concentration-time curves. As part of the previous study, 100 patients (59 male, 41 female; mean [SD] age, 51.4 [13.8] years;age range, 20-75 years) were enrolled in the study The calculated MRT was significantly shorter in recipients with acute allograft rejection (11.32 [031] hours vs 11.52 [028] hours; P = 0.02), just like T(max) was an independent risk factor for acute rejection in a multivariate logistic regression model (odds ratio, 0.092 [95% CI, 0.014-0.629]; P = 0.01). Analyzing the impact of demographic, transplantation-related, and biochemical variables on MRT, we found that increasing serum albumin and hematocrit concentrations were associated with a prolonged MRT (P calculated MRT were associated with a higher incidence of early acute graft rejection. These findings suggest that a shorter transit time of tacrolimus in certain tissue compartments, rather than failure to obtain a maximum absolute tacrolimus blood concentration, might lead to inadequate immunosuppression early after transplantation.

Radiation exposure during ureteroscopy

International Nuclear Information System (INIS)

Bagley, D.H.; Cubler-Goodman, A.

1990-01-01

Use of fluoroscopy during ureteroscopy increases the risk of radiation exposure to the urologist and patient. Radiation entrance dosages were measured at skin level in 37 patients, and at the neck, trunk and finger of the urologist, and neck and trunk of the circulating nurse. Radiation exposure time was measured in 79 patients, and was related to the purpose of the procedure and the type of ureteroscope used, whether rigid or flexible. Exposure could be minimized by decreasing the fluoroscopy time. A portable C-arm fluoroscopy unit with electronic imaging and last image hold mode should be used to minimize exposure time. Lead aprons and thyroid shields should be used by the urologist and other personnel in the endoscopy room

Personality traits and combat exposure as predictors of psychopathology over time.

Science.gov (United States)

Koffel, E; Kramer, M D; Arbisi, P A; Erbes, C R; Kaler, M; Polusny, M A

2016-01-01

Research suggests that personality traits have both direct and indirect effects on the development of psychological symptoms, with indirect effects mediated by stressful or traumatic events. This study models the direct influence of personality traits on residualized changes in internalizing and externalizing symptoms following a stressful and potentially traumatic deployment, as well as the indirect influence of personality on symptom levels mediated by combat exposure. We utilized structural equation modeling with a longitudinal prospective study of 522 US National Guard soldiers deployed to Iraq. Analyses were based on self-report measures of personality, combat exposure, and internalizing and externalizing symptoms. Both pre-deployment Disconstraint and externalizing symptoms predicted combat exposure, which in turn predicted internalizing and externalizing symptoms. There was a significant indirect effect for pre-deployment externalizing symptoms on post-deployment externalizing via combat exposure (p personality on residualized changes in externalizing symptoms were found. Baseline symptom dimensions had significant direct and indirect effects on post-deployment symptoms. Controlling for both pre-exposure personality and symptoms, combat experiences remained positively related to both internalizing and externalizing symptoms. Implications for diagnostic classification are discussed.

The validated sun exposure questionnaire

DEFF Research Database (Denmark)

Køster, B; Søndergaard, J; Nielsen, J B

2017-01-01

Few questionnaires used in monitoring sun-related behavior have been tested for validity. We established criteria validity of a developed questionnaire for monitoring population sun-related behavior. During May-August 2013, 664 Danes wore a personal electronic UV-dosimeter for one week...... that measured the outdoor time and dose of erythemal UVR exposure. In the following week, they answered a questionnaire on their sun-related behavior in the measurement week. Outdoor time measured by dosimetry correlated strongly with both outdoor time and the developed exposure scale measured...... in the questionnaire. Exposure measured in SED by dosimetry correlated strongly with the exposure scale. In a linear regression model of UVR (SED) received, 41 percent of the variation was explained by skin type, age, week of participation and the exposure scale, with the exposure scale as the main contributor...

Minimally invasive oesophagectomy more expensive than open despite shorter length of stay.

Science.gov (United States)

Dhamija, Anish; Dhamija, Ankit; Hancock, Jacquelyn; McCloskey, Barbara; Kim, Anthony W; Detterbeck, Frank C; Boffa, Daniel J

2014-05-01

The minimally invasive oesophagectomy (MIO) approach offers a number of advantages over open approaches including reduced discomfort, shorter length of stay and a faster recovery to baseline status. On the other hand, minimally invasive procedures typically are longer and consume greater disposable instrumentation, potentially resulting in a greater overall cost. The objective of this study was to compare costs associated with various oesophagectomy approaches for oesophageal cancer. An institutional Resource Information Management System (RIMS) was queried for cost data relating to hospital expenditures (as opposed to billings or collections). The RIMS was searched for patients undergoing oesophagectomy for oesophageal cancer between 2003 and 2012 via minimally invasive, open transthoracic (OTT) (including Ivor Lewis, modified McKeown or thoracoabdominal) or transhiatal approaches. Patients that were converted from minimally invasive to open, or involved hybrid procedures, were excluded. A total of 160 oesophagectomies were identified, including 61 minimally invasive, 35 open transthoracic and 64 transhiatal. Costs on the day of surgery averaged higher in the MIO group ($12 476 ± 2190) compared with the open groups, OTT ($8202 ± 2512, P < 0.0001) or OTH ($5809 ± 2575, P < 0.0001). The median costs associated with the entire hospitalization also appear to be higher in the MIO group ($25 935) compared with OTT ($24 440) and OTH ($15 248). The average length of stay was lowest in the MIO group (11 ± 9 days) compared with OTT (19 ± 18 days, P = 0.006) and OTH (18 ± 28 days P = 0.07). The operative mortality was similar in the three groups (MIO = 3%, OTT = 9% and OTH = 3%). The operating theatre costs associated with minimally invasive oesophagectomy are significantly higher than OTT or OTH approaches. Unfortunately, a shorter hospital stay after MIO does not consistently offset higher surgical expense, as total hospital costs trend higher in the MIO patients. In

Suspected survivor bias in case-control studies: stratify on survival time and use a negative control.

Science.gov (United States)

van Rein, Nienke; Cannegieter, Suzanne C; Rosendaal, Frits R; Reitsma, Pieter H; Lijfering, Willem M

2014-02-01

Selection bias in case-control studies occurs when control selection is inappropriate. However, selection bias due to improper case sampling is less well recognized. We describe how to recognize survivor bias (i.e., selection on exposed cases) and illustrate this with an example study. A case-control study was used to analyze the effect of statins on major bleedings during treatment with vitamin K antagonists. A total of 110 patients who experienced such bleedings were included 18-1,018 days after the bleeding complication and matched to 220 controls. A protective association of major bleeding for exposure to statins (odds ratio [OR]: 0.56; 95% confidence interval: 0.29-1.08) was found, which did not become stronger after adjustment for confounding factors. These observations lead us to suspect survivor bias. To identify this bias, results were stratified on time between bleeding event and inclusion, and repeated for a negative control (an exposure not related to survival): blood group non-O. The ORs for exposure to statins increased gradually to 1.37 with shorter time between outcome and inclusion, whereas ORs for the negative control remained constant, confirming our hypothesis. We recommend the presented method to check for overoptimistic results, that is, survivor bias in case-control studies. Copyright © 2014 Elsevier Inc. All rights reserved.

Context-sensitive ecological momentary assessments; integrating real-time exposure measurements, data-analytics and health assessment using a smartphone application.

Science.gov (United States)

van Wel, Luuk; Huss, Anke; Bachmann, Philipp; Zahner, Marco; Kromhout, Hans; Fröhlich, Jürg; Vermeulen, Roel

2017-06-01

Modern sensor technology makes it possible to collect vast amounts of environmental, behavioural and health data. These data are often linked to contextual information on for example exposure sources which is separately collected with considerable lag time, leading to complications in assessing transient and/or highly spatially variable environmental exposures. Context-Sensitive Ecological Momentary Assessments 1 (CS-EMAs) could be used to address this. We present a case study using radiofrequency-electromagnetic fields (RF-EMF) exposure as an example for implementing CS-EMA in environmental research. Participants were asked to install a custom application on their own smartphone and to wear an RF-EMF exposimeter for 48h. Questionnaires were triggered by the application based on a continuous data stream from the exposimeter. Triggers were divided into four categories: relative and absolute exposure levels, phone calls, and control condition. After the two days of use participants filled in an evaluation questionnaire. 74% of all CS-EMAs were completed, with an average time of 31s to complete a questionnaire once it was opened. Participants reported minimal influence on daily activities. There were no significant differences found between well-being and type of RF-EMF exposure. We show that a CS-EMA based method could be used in environmental research. Using several examples involving environmental stressors, we discuss both current and future applications of this methodology in studying potential health effects of environmental factors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Large-scale analysis of acute ethanol exposure in zebrafish development: a critical time window and resilience.

Directory of Open Access Journals (Sweden)

Shaukat Ali

Full Text Available BACKGROUND: In humans, ethanol exposure during pregnancy causes a spectrum of developmental defects (fetal alcohol syndrome or FAS. Individuals vary in phenotypic expression. Zebrafish embryos develop FAS-like features after ethanol exposure. In this study, we ask whether stage-specific effects of ethanol can be identified in the zebrafish, and if so, whether they allow the pinpointing of sensitive developmental mechanisms. We have therefore conducted the first large-scale (>1500 embryos analysis of acute, stage-specific drug effects on zebrafish development, with a large panel of readouts. METHODOLOGY/PRINCIPAL FINDINGS: Zebrafish embryos were raised in 96-well plates. Range-finding indicated that 10% ethanol for 1 h was suitable for an acute exposure regime. High-resolution magic-angle spinning proton magnetic resonance spectroscopy showed that this produced a transient pulse of 0.86% concentration of ethanol in the embryo within the chorion. Survivors at 5 days postfertilisation were analysed. Phenotypes ranged from normal (resilient to severely malformed. Ethanol exposure at early stages caused high mortality (≥88%. At later stages of exposure, mortality declined and malformations developed. Pharyngeal arch hypoplasia and behavioral impairment were most common after prim-6 and prim-16 exposure. By contrast, microphthalmia and growth retardation were stage-independent. CONCLUSIONS: Our findings show that some ethanol effects are strongly stage-dependent. The phenotypes mimic key aspects of FAS including craniofacial abnormality, microphthalmia, growth retardation and behavioral impairment. We also identify a critical time window (prim-6 and prim-16 for ethanol sensitivity. Finally, our identification of a wide phenotypic spectrum is reminiscent of human FAS, and may provide a useful model for studying disease resilience.

A single exposure to immobilization causes long-lasting pituitary-adrenal and behavioral sensitization to mild stressors.

Science.gov (United States)

Belda, Xavier; Fuentes, Silvia; Nadal, Roser; Armario, Antonio

2008-11-01

We have previously reported that a single exposure to immobilization (IMO) in rats causes a long-term desensitization of the hypothalamic-pituitary-adrenal (HPA) response to the same (homotypic) stressor. Since there are reports showing that a single exposure to other stressors causes sensitization of the HPA response to heterotypic stressors and increases anxiety-like behavior, we studied in the present work the long-term effects of IMO on behavioral and HPA response to mild superimposed stressors. In Experiments 1 and 2, adult male Sprague-Dawley rats were subjected to 2 h of IMO and then exposed for 5 min to the elevated plus-maze (EPM) at 1, 3 or 7 days after IMO. Blood samples were taken at 15 min after initial exposure to the EPM. Increases in anxiety-like behavior and HPA responsiveness to the EPM were found at all times post-IMO. Changes in the resting levels of HPA hormones did not explain the enhanced HPA responsiveness to the EPM (Experiment 3). In Experiments 4 and 5, we studied the effects of a single exposure to a shorter session of IMO (1 h) on behavioral and HPA responses to a brief and mild session of foot-shocks done 10 days after IMO. Neither previous IMO nor exposure to shocks in control rats modified behavior in the EPM. However, a brief session of shocks in previously IMO-exposed rats dramatically increased anxiety in the EPM. HPA and freezing responses to shocks were similar in control and previous IMO groups. Therefore, a single exposure to IMO appears to induce long-lasting HPA and behavioral sensitization to mild superimposed stressors, although the two responses are likely to be at least partially independent. Long-term effects of IMO on the susceptibility to stress-induced endocrine and emotional disturbances may be relevant to the characterization of animal models of post-traumatic stress.

Radon daughter exposure estimation and its relation to the exposure limit

International Nuclear Information System (INIS)

Stocker, H.

1981-10-01

Under current Atomic Energy Control Regulations, the annual limit for individual exposure to radon daughters is 4 WLM. The Regulations do not specify how the exposure is to be determined nor to what accuracy the measurements should be made. This paper discusses the historical and conventional grab-sampling and time-weighting methods for assigning exposures to radon daughters in uranium mines in Canada. As a further step in the evolution of exposure assignments, the system of personal radon daughter dosimetry is introduced as the more accurate means of assigning individual exposures and of adhering to the intent of the exposure limit

Timing of prenatal exposure to trauma and altered placental expressions of hypothalamic-pituitary-adrenal axis genes and genes driving neurodevelopment.

Science.gov (United States)

Zhang, W; Li, Q; Deyssenroth, M; Lambertini, L; Finik, J; Ham, J; Huang, Y; Tsuchiya, K J; Pehme, P; Buthmann, J; Yoshida, S; Chen, J; Nomura, Y

2018-04-01

Prenatal maternal stress increases the risk for negative developmental outcomes in offspring; however, the underlying biological mechanisms remain largely unexplored. In the present study, alterations in placental gene expression associated with maternal stress were examined to clarify the potential underlying epi/genetic mechanisms. Expression levels of 40 selected genes involved in regulating foetal hypothalamic-pituitary-adrenal axis and neurodevelopment were profiled in placental tissues collected from a birth cohort established around the time of Superstorm Sandy. Objective prenatal traumatic stress was defined as whether mothers were exposed to Superstorm Sandy during pregnancy. Among the 275 mother-infant dyads, 181 dyads were delivered before Superstorm Sandy (ie, Control), 66 dyads were exposed to Superstorm Sandy during the first trimester (ie, Early Exposure) and 28 were exposed to Superstorm Sandy during the second or third trimester (ie, Mid-Late Exposure). Across all trimesters, expression of HSD11B2, MAOA, ZNF507 and DYRK1A was down-regulated among those exposed to Superstorm Sandy during pregnancy. Furthermore, trimester-specific differences were also observed: exposure during early gestation was associated with down-regulation of HSD11B1 and MAOB and up-regulation of CRHBP; exposure during mid-late gestation was associated with up-regulation of SRD5A3. The findings of the present study suggest that placental gene expression may be altered in response to traumatic stress exposure during pregnancy, and the susceptibility of these genes is dependent on the time of the exposure during pregnancy. Further studies should aim to clarify the biological mechanisms that underlie trimester-specific exposure by evaluating the differential impact on offspring neurodevelopment later in childhood. © 2018 British Society for Neuroendocrinology.

Workplace exposure to nanoparticles and the application of provisional nanoreference values in times of uncertain risks

Science.gov (United States)

van Broekhuizen, Pieter; van Broekhuizen, Fleur; Cornelissen, Ralf; Reijnders, Lucas

2012-03-01

Nano reference values (NRVs) for occupational use of nanomaterials were tested as provisional substitute for Occupational Exposure Limits (OELs). NRVs can be used as provisional limit values until Health-Based OELs or derived no-effect levels (DNEL) become available. NRVs were defined for 8 h periods (time weighted average) and for short-term exposure periods (15 min-time weighted average). To assess the usefulness of these NRVs, airborne number concentrations of nanoparticles (NPs) in the workplace environment were measured during paint manufacturing, electroplating, light equipment manufacturing, non-reflective glass production, production of pigment concentrates and car refinishing. Activities monitored were handling of solid engineered NPs (ENP), abrasion, spraying and heating during occupational use of nanomaterials (containing ENPs) and machining nanosurfaces. The measured concentrations are often presumed to contain ENPs as well as process-generated NPs (PGNP). The PGNP are found to be a significant source for potential exposure and cannot be ignored in risk assessment. Levels of NPs identified in workplace air were up to several millions of nanoparticles/cm3. Conventional components in paint manufacturing like CaCO3 and talc may contain a substantial amount of nanosized particulates giving rise to airborne nanoparticle concentrations. It is argued that risk assessments carried out for e.g. paint manufacturing processes using conventional non-nano components should take into account potential nanoparticle emissions as well. The concentrations measured were compared with particle-based NRVs and with mass-based values that have also been proposed for workers protection. It is concluded that NRVs can be used for risk management for handling or processing of nanomaterials at workplaces provided that the scope of NRVs is not limited to ENPs only, but extended to the exposure to process-generated NPs as well.

Workplace exposure to nanoparticles and the application of provisional nanoreference values in times of uncertain risks

International Nuclear Information System (INIS)

Broekhuizen, Pieter van; Broekhuizen, Fleur van; Cornelissen, Ralf; Reijnders, Lucas

2012-01-01

Nano reference values (NRVs) for occupational use of nanomaterials were tested as provisional substitute for Occupational Exposure Limits (OELs). NRVs can be used as provisional limit values until Health-Based OELs or derived no-effect levels (DNEL) become available. NRVs were defined for 8 h periods (time weighted average) and for short-term exposure periods (15 min-time weighted average). To assess the usefulness of these NRVs, airborne number concentrations of nanoparticles (NPs) in the workplace environment were measured during paint manufacturing, electroplating, light equipment manufacturing, non-reflective glass production, production of pigment concentrates and car refinishing. Activities monitored were handling of solid engineered NPs (ENP), abrasion, spraying and heating during occupational use of nanomaterials (containing ENPs) and machining nanosurfaces. The measured concentrations are often presumed to contain ENPs as well as process-generated NPs (PGNP). The PGNP are found to be a significant source for potential exposure and cannot be ignored in risk assessment. Levels of NPs identified in workplace air were up to several millions of nanoparticles/cm 3 . Conventional components in paint manufacturing like CaCO 3 and talc may contain a substantial amount of nanosized particulates giving rise to airborne nanoparticle concentrations. It is argued that risk assessments carried out for e.g. paint manufacturing processes using conventional non-nano components should take into account potential nanoparticle emissions as well. The concentrations measured were compared with particle-based NRVs and with mass-based values that have also been proposed for workers protection. It is concluded that NRVs can be used for risk management for handling or processing of nanomaterials at workplaces provided that the scope of NRVs is not limited to ENPs only, but extended to the exposure to process-generated NPs as well.

Retrospective: animal attacks and rabies exposures in Thai children.

Science.gov (United States)

Sriaroon, Chakrapol; Sriaroon, Panida; Daviratanasilpa, Svastijaya; Khawplod, Pakamatz; Wilde, Henry

2006-09-01

Over 50% of animal bites and potential rabies exposures in Thailand are in children and they also have the more severe injuries due to inexperience, smaller size and less ability to fend off attacks. Potential rabies exposures and animal bites are common in Thailand. Majority of these are in children where the extent of the injuries is also much more severe. The bitten areas correlate to the age of the children and level of the bitten animal head. These are areas noted for a higher risk of infection with rabies virus and shorter incubation periods. The vast majority of bites are due to dogs (86%) of which 74.6% are stray or community-owned animals. The prevalence of dog bites shows no seasonal variation in adults but there are two peaks during school vacation period for children. Extensive educational efforts directed at the Thai public are responsible for the rapid presentation of victims for post-exposure treatment. The dramatic reduction of human rabies deaths in Thailand during the last decades was achieved largely by the provision of expensive WHO standard post-exposure treatment, utilizing modern tissue culture vaccines and immunoglobulins. Canine and feline rabies is nevertheless still endemic and not likely to be controlled or eliminated till sustainable humane methods of dog population control and comprehensive countrywide canine rabies vaccination become possible through government policy.

Quantifying Risk Over the Life Course – Latency, Age-Related Susceptibility, and Other Time-Varying Exposure Metrics

Science.gov (United States)

Wang, Molin; Liao, Xiaomei; Laden, Francine; Spiegelman, Donna

2016-01-01

Identification of the latency period and age-related susceptibility, if any, is an important aspect of assessing risks of environmental, nutritional and occupational exposures. We consider estimation and inference for latency and age-related susceptibility in relative risk and excess risk models. We focus on likelihood-based methods for point and interval estimation of the latency period and age-related windows of susceptibility coupled with several commonly considered exposure metrics. The method is illustrated in a study of the timing of the effects of constituents of air pollution on mortality in the Nurses’ Health Study. PMID:26750582

Perfluoroalkyl substances exposure and thyroid hormones in humans: epidemiological observations and implications

Directory of Open Access Journals (Sweden)

Jung Eun Lee

2017-03-01

Full Text Available Thyroid hormones play crucial roles in normal neurodevelopment of fetus and child. Many chemicals can affect control and homeostasis of thyroid hormones, and eventually lead to various adverse health effects including neurodevelopmental disorders. Perfluoroalkyl substances (PFASs are among the thyroid disrupting chemicals that can be encountered among general human population. Due to their unique physicochemical characteristics, PFASs have been used as surfactants and surface coating materials in many applications. Therefore, PFASs have been frequently detected in humans and environment worldwide. In cross-sectional studies using nationally representative general human populations of United States, several PFASs have shown significant associations with thyroid hormones. Moreover, among pregnant women and their infants, not only major PFASs such as perfluorooctane sulfonic acid and perfluorooctanoic acid, but also those with shorter or longer carbon chains showed significant associations with thyroid hormones. Often demographic characteristics such as sex, age, and disease status appear to influence the associations between PFASs exposure and thyroid hormones. In general, major PFASs showed hypothyroidism effects among pregnant women and infants. As 8 carbon based PFASs have been phased out, those with shorter or longer carbon chains have been used in growing amount as replacement. However, only limited information is available for their occurrences and toxicity among humans. Further investigations on these substituting PFASs are required. In addition, efforts are warranted to identify sources of and mitigate exposure to these thyroid disrupting chemicals especially during pregnancy and early stages of life.

Quantitative fluorescence in situ hybridization measurement of telomere length in skin with/without sun exposure or actinic keratosis.

Science.gov (United States)

Ikeda, Hiroyuki; Aida, Junko; Hatamochi, Atsushi; Hamasaki, Yoichiro; Izumiyama-Shimomura, Naotaka; Nakamura, Ken-Ichi; Ishikawa, Naoshi; Poon, Steven S; Fujiwara, Mutsunori; Tomita, Ken-Ichiro; Hiraishi, Naoki; Kuroiwa, Mie; Matsuura, Masaaki; Sanada, Yukihiro; Kawano, Youichi; Arai, Tomio; Takubo, Kaiyo

2014-03-01

Chromosomal and genomic instability due to telomere dysfunction is known to play an important role in carcinogenesis. To study telomere shortening in the epidermis surrounding actinic keratosis, we measured telomere lengths of basal, parabasal, and suprabasal cells in epidermis with actinic keratosis (actinic keratosis group, n = 18) and without actinic keratosis (sun-protected, n = 15, and sun-exposed, n = 13 groups) and in actinic keratosis itself as well as in dermal fibroblasts in the 3 groups, using quantitative fluorescence in situ hybridization. Among the 3 cell types, telomeres of basal cells were not always the longest, suggesting that tissue stem cells are not necessarily located among basal cells. Telomeres of basal cells in the sun-exposed group were shorter than those in the sun-protected group. Telomeres in the background of actinic keratosis and in actinic keratosis itself and those of fibroblasts in actinic keratosis were significantly shorter than those in the controls. Our findings demonstrate that sun exposure induces telomere shortening and that actinic keratosis arises from epidermis with shorter telomeres despite the absence of any histologic atypia. © 2014.

Infection of the malaria mosquito, Anopheles gambiae, with two species of entomopathogenic fungi: effects of concentration, co-formulation, exposure time and persistence

Directory of Open Access Journals (Sweden)

Lwetoijera Dickson W

2009-12-01

Full Text Available Abstract Background Entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana isolates have been shown to infect and reduce the survival of mosquito vectors. Methods Here four different bioassays were conducted to study the effect of conidia concentration, co-formulation, exposure time and persistence of the isolates M. anisopliae ICIPE-30 and B. bassiana I93-925 on infection and survival rates of female Anopheles gambiae sensu stricto. Test concentrations and exposure times ranged between 1 × 107 - 4 × 1010 conidia m-2 and 15 min - 6 h. In co-formulations, 2 × 1010 conidia m-2 of both fungus isolates were mixed at ratios of 4:1, 2:1, 1:1,1:0, 0:1, 1:2 and 1:4. To determine persistence, mosquitoes were exposed to surfaces treated 1, 14 or 28 d previously, with conidia concentrations of 2 × 109, 2 × 1010 or 4 × 1010. Results Mosquito survival varied with conidia concentration; 2 × 1010 conidia m-2 was the concentration above which no further reductions in survival were detectable for both isolates of fungus. The survival of mosquitoes exposed to single and co-formulated treatments was similar and no synergistic or additive effects were observed. Mosquitoes were infected within 30 min and longer exposure times did not result in a more rapid killing effect. Fifteen min exposure still achieved considerable mortality rates (100% mortality by 14 d of mosquitoes, but at lower speed than with 30 min exposure (100% mortality by 9 d. Conidia remained infective up to 28 d post-application but higher concentrations did not increase persistence. Conclusion Both fungus isolates are effective and persistent at low concentrations and short exposure times.

The brain is a target organ after acute exposure to depleted uranium.

Science.gov (United States)

Lestaevel, P; Houpert, P; Bussy, C; Dhieux, B; Gourmelon, P; Paquet, F

2005-09-01

The health effects of depleted uranium (DU) are mainly caused by its chemical toxicity. Although the kidneys are the main target organs for uranium toxicity, uranium can also reach the brain. In this paper, the central effects of acute exposure to DU were studied in relation to health parameters and the sleep-wake cycle of adult rats. Animals were injected intraperitoneally with 144+/-10 microg DU kg-1 as nitrate. Three days after injection, the amounts of uranium in the kidneys represented 2.6 microg of DU g-1 of tissue, considered as a sub-nephrotoxic dosage. The central effect of uranium could be seen through a decrease in food intake as early as the first day after exposure and shorter paradoxical sleep 3 days after acute DU exposure (-18% of controls). With a lower dosage of DU (70+/-8 microg DU kg-1), no significant effect was observed on the sleep-wake cycle. The present study intends to illustrate the fact that the brain is a target organ, as are the kidneys, after acute exposure to a moderate dosage of DU. The mechanisms by which uranium causes these early neurophysiological perturbations shall be discussed.

How to determine life expectancy change of air pollution mortality: a time series study

Directory of Open Access Journals (Sweden)

Chau PYK

2011-03-01

Full Text Available Abstract Background Information on life expectancy (LE change is of great concern for policy makers, as evidenced by discussions of the "harvesting" (or "mortality displacement" issue, i.e. how large an LE loss corresponds to the mortality results of time series (TS studies. Whereas loss of LE attributable to chronic air pollution exposure can be determined from cohort studies, using life table methods, conventional TS studies have identified only deaths due to acute exposure, during the immediate past (typically the preceding one to five days, and they provide no information about the LE loss per death. Methods We show how to obtain information on population-average LE loss by extending the observation window (largest "lag" of TS to include a sufficient number of "impact coefficients" for past exposures ("lags". We test several methods for determining these coefficients. Once all of the coefficients have been determined, the LE change is calculated as time integral of the relative risk change after a permanent step change in exposure. Results The method is illustrated with results for daily data of non-accidental mortality from Hong Kong for 1985 - 2005, regressed against PM10 and SO2 with observation windows up to 5 years. The majority of the coefficients is statistically significant. The magnitude of the SO2 coefficients is comparable to those for PM10. But a window of 5 years is not sufficient and the results for LE change are only a lower bound; it is consistent with what is implied by other studies of long term impacts. Conclusions A TS analysis can determine the LE loss, but if the observation window is shorter than the relevant exposures one obtains only a lower bound.

Early Adolescent Boys' Exposure to Internet Pornography: Relationships to Pubertal Timing, Sensation Seeking, and Academic Performance

Science.gov (United States)

Beyens, Ine; Vandenbosch, Laura; Eggermont, Steven

2015-01-01

Research has demonstrated that adolescents regularly use Internet pornography. This two-wave panel study aimed to test an integrative model in early adolescent boys (M[subscript age] = 14.10; N = 325) that (a) explains their exposure to Internet pornography by looking at relationships with pubertal timing and sensation seeking, and (b) explores…

Characterization of new eye drops with choline salicylate and assessment of their irritancy by in vitro short time exposure tests.

Science.gov (United States)

Wroblewska, Katarzyna; Kucinska, Małgorzata; Murias, Marek; Lulek, Janina

2015-09-01

The aim of our study was to examine the irritation potential of new eye drops containing 2% choline salicylate (CS) as an active pharmaceutical ingredient (API) and various polymers increasing eye drop viscosity (hydroxyethylcellulose, hydroxypropyl methylcellulose, methylcellulose, polyvinyl alcohol, polyvinylpyrrolidone). The standard method for assessing the potential of irritating substances has been the Draize rabbit eye test. However the European Centre for Validation of Alternative Methods and the Coordinating Committee for Validation of Alternative Methods recommend, short time exposure (STE) in vitro tests as an alternative method for assessing eye irritation. The eye irritation potential was determined using cytotoxicity test methods for rabbit corneal cell line (SIRC) after 5 min exposure. The viability of cells was determined using two cytotoxicity assays: MTT and Neutral Red Uptake. According to the irritation rankings for the short time exposure test, all tested eye drops are classified as non-irritating (cell viability >70%).

Designing and assessment of accuracy of an algorithm for determining the accuracy of radiographic film density by changing exposure time

Directory of Open Access Journals (Sweden)

Hoorieh Bashizadeh Fakhar

2014-06-01

Full Text Available   Background and Aims Bone density is frequently used in medical diagnosis and research. The current methods for determining bone density are expensive and not easily available in dental clinics. The aim of this study was to design and evaluate the accuracy of a digital method for hard tissue densitometry which could be applied on personal computers.   Materials and Methods: An aluminum step wedge was constructed. 50 E-speed Kodak films were exposed. Exposure time varied from 0.05s to 0.5 s with 0.05 s interval. Films were developed with automatic developer and fixer and digitized with 1240U photo Epson scanner. Images were cropped at 10 × 10mm size with Microsoft Office Picture Manager. By running the algorithm designed in MATLAB software, the mean pixel value of pictures was calculated.   Results: Finding of this study showed that by increasing the exposure time, the mean pixel value was decreased and at step 12, a significant discrimination was seen between the two subsequent times(P<0.001. By increasing the thickness of object, algorithm could define the density changes from step 4 in 0.3 s and 5 in 0.5 s, and it could determine the differences in the mean pixel value between the same steps of 0.3 s and 0.5 s from step 4.   Conclusion: By increasing the object thickness and exposure time, the accuracy of the algorithm for recognizing changes in density was increased. This software was able to determine the radiographic density changes of aluminum step wedge with at least 4mm thickness at exposure time of 0.3 s and 5 mm at 0.5 s.

[Accumulative effects and long-term persistence of subliminal mere exposure].

Science.gov (United States)

Kawakami, Naoaki; Yoshida, Fujio

2011-10-01

We examined the accumulative effects and long-term persistence of subliminal mere exposure. An accumulative exposure condition (100 exposures distributed over five days) and a massed exposure condition (100 exposures in one day) were used in a Go/No-go Association Task (GNAT), with assessments of likability from Time 1 (just after) to Time 6 (after three months). First, a single stimulus was shown subliminally for a total of 100 times. The results indicated that mere exposure effects occurred equally often at Time 1. However, after Time 2, likability gradually decreased under the massed exposure condition, while it did not decrease under the accumulative exposure condition until Time 6. Second, in order to investigate the effect of multiple exposure, five stimuli belonging to a common category were shown 20 times each, for a total of 100 times. An ANOVA suggested that massed exposure had an instantaneous effect on likability, whereas accumulative exposure had a long-term persistence effect. Also, multiple exposures strengthened the mere exposure effect.

Surface effect of KrF laser exposure on ECE of alpha particle tracks in polycarbonate polymer

Energy Technology Data Exchange (ETDEWEB)

Parvin, P. [Physics Department, Amirkabir University, P.O. Box 15875-4413, Hafez Ave, Tehran (Iran, Islamic Republic of) and Laser Research Center, Atomic Energy Organization of Iran, AEOI, Tehran (Iran, Islamic Republic of)]. E-mail: parvin@aut.ac.ir; Jaleh, B. [Physics Department, Bu Ali Sina University, Hamadan (Iran, Islamic Republic of); Sheikh, N. [Gamma Irradiation Center, AEOI, Tehran (Iran, Islamic Republic of); Amiri, N. [Physics Department, Emam Hossien University, Tehran (Iran, Islamic Republic of)

2005-11-15

The optical penetration depth for polycarbonate (PC) at 308nm due to XeCl laser is about 450{mu}m while those of KrF (248nm) and ArF (193nm) lasers become noticeably shorter to 1{mu}m and 20nm, respectively, to show the strong superficial absorption at shorter UV wavelengths. On the other hand, KrF laser exposure on polycarbonate, at doses above 6J/cm{sup 2}, creates the surface crosslinking. In spite of several reliable methods available, such as 'hot set' and 'gel content', to determine the bulk crosslinking, there are a few consistent techniques to evaluate the surface crosslinking effect quantitatively. It includes hardening measurements using nanoindenter or AFM (atomic force microscopy). In this work, we present a technique for the measurement of superficial crosslinking, based on electrochemical etching of alpha irradiated polycarbonate accordingly. The mean diameter of the developed tracks nonlinearly decreases for KrF laser treatment at higher doses. The relative shrinkage of track diameters due to UV exposure before alpha irradiation, comparing to those without UV pre-radiation, indicates that UV laser makes the polymer surface hardened. The variation of mean track diameters can be strongly used to quantify the surface crosslinking.

Surface effect of KrF laser exposure on ECE of alpha particle tracks in polycarbonate polymer

International Nuclear Information System (INIS)

Parvin, P.; Jaleh, B.; Sheikh, N.; Amiri, N.

2005-01-01

The optical penetration depth for polycarbonate (PC) at 308nm due to XeCl laser is about 450μm while those of KrF (248nm) and ArF (193nm) lasers become noticeably shorter to 1μm and 20nm, respectively, to show the strong superficial absorption at shorter UV wavelengths. On the other hand, KrF laser exposure on polycarbonate, at doses above 6J/cm 2 , creates the surface crosslinking. In spite of several reliable methods available, such as 'hot set' and 'gel content', to determine the bulk crosslinking, there are a few consistent techniques to evaluate the surface crosslinking effect quantitatively. It includes hardening measurements using nanoindenter or AFM (atomic force microscopy). In this work, we present a technique for the measurement of superficial crosslinking, based on electrochemical etching of alpha irradiated polycarbonate accordingly. The mean diameter of the developed tracks nonlinearly decreases for KrF laser treatment at higher doses. The relative shrinkage of track diameters due to UV exposure before alpha irradiation, comparing to those without UV pre-radiation, indicates that UV laser makes the polymer surface hardened. The variation of mean track diameters can be strongly used to quantify the surface crosslinking

Access to Electric Light Is Associated with Shorter Sleep Duration in a Traditionally Hunter-Gatherer Community.

Science.gov (United States)

de la Iglesia, Horacio O; Fernández-Duque, Eduardo; Golombek, Diego A; Lanza, Norberto; Duffy, Jeanne F; Czeisler, Charles A; Valeggia, Claudia R

2015-08-01

Access to electric light might have shifted the ancestral timing and duration of human sleep. To test this hypothesis, we studied two communities of the historically hunter-gatherer indigenous Toba/Qom in the Argentinean Chaco. These communities share the same ethnic and sociocultural background, but one has free access to electricity while the other relies exclusively on natural light. We fitted participants in each community with wrist activity data loggers to assess their sleep-wake cycles during one week in the summer and one week in the winter. During the summer, participants with access to electricity had a tendency to a shorter daily sleep bout (43 ± 21 min) than those living under natural light conditions. This difference was due to a later daily bedtime and sleep onset in the community with electricity, but a similar sleep offset and rise time in both communities. In the winter, participants without access to electricity slept longer (56 ± 17 min) than those with access to electricity, and this was also related to earlier bedtimes and sleep onsets than participants in the community with electricity. In both communities, daily sleep duration was longer during the winter than during the summer. Our field study supports the notion that access to inexpensive sources of artificial light and the ability to create artificially lit environments must have been key factors in reducing sleep in industrialized human societies. © 2015 The Author(s).

Comprehensive borehole management for shorter drilling time; Umfassendes Bohrfortschrittsmanagement zur Verkuerzung der Bohrprojektdauer

Energy Technology Data Exchange (ETDEWEB)

Roehrlich, M. [ExxonMobil Production Deutschland GmbH, Hannover (Germany)

2007-09-13

In 2006, the trademarked ExxonMobil Fast Drill Process (FDP) was introduced also in the German ExxonMobil boreholes. The process is to maximize the drilling speed for every meter drilled. The process makes it possible to ensure borehole management on the basis of quantitative data and in consideration of all phases that are relevant for sinking a borehole. The FDP is used world-wide in all ExxonMobil drilling departments. More than 1.35 million meters are drilled annually in many different boreholes with different geological conditions, drilling profiles and international sites. The results were similar in many cases, with a significant increase in ROP and drill bit life, and with less damage caused by vibrations. FDP was developed on the basis of real time monitoring of the specific mechanical energy (MSE) required for drilling. MSE monitoring was found to be an effective tool dor detecting inefficient functioning of the drill bit and the overall system. To make operation more efficient, the causes must be identified and measures must be taken accordingly, taking into account the potential risks involved in such measures. MSE monitoring is a tool while FDPL is a broad management process ensuring that MSE and many other data sources are used effectively for optimisation of the ROP. Consequent implementation of the process resulted in a significant increase of the ROP. The major elements required for achieving this goal are discussed. (orig.)

Time course of systemic oxidative stress and inflammatory response induced by an acute exposure to Residual Oil Fly Ash

Energy Technology Data Exchange (ETDEWEB)

Marchini, T.; Magnani, N.D. [Cátedra de Química General e Inorgánica, Instituto de Bioquímica y Medicina Molecular (IBIMOL UBA-CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 954, C1113AAB Buenos Aires (Argentina); Paz, M.L. [Cátedra de Inmunología, Instituto de Estudios de la Inmunidad Humoral (IDEHU UBA-CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 954, C1113AAB Buenos Aires (Argentina); Vanasco, V. [Cátedra de Química General e Inorgánica, Instituto de Bioquímica y Medicina Molecular (IBIMOL UBA-CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 954, C1113AAB Buenos Aires (Argentina); Tasat, D. [CESyMA, Facultad de Ciencia Tecnología, Universidad Nacional de General San Martín, Martín de Irigoyen 3100, 1650 San Martín, Buenos Aires (Argentina); González Maglio, D.H. [Cátedra de Inmunología, Instituto de Estudios de la Inmunidad Humoral (IDEHU UBA-CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 954, C1113AAB Buenos Aires (Argentina); and others

2014-01-15

It is suggested that systemic oxidative stress and inflammation play a central role in the onset and progression of cardiovascular diseases associated with the exposure to particulate matter (PM). The aim of this work was to evaluate the time changes of systemic markers of oxidative stress and inflammation, after an acute exposure to Residual Oil Fly Ash (ROFA). Female Swiss mice were intranasally instilled with a ROFA suspension (1.0 mg/kg body weight) or saline solution, and plasma levels of oxidative damage markers [thiobarbituric acid reactive substances (TBARSs) and protein carbonyls], antioxidant status [reduced (GSH) and oxidized (GSSG) glutathione, ascorbic acid levels, and superoxide dismutase (SOD) activity], cytokines levels, and intravascular leukocyte activation were evaluated after 1, 3 or 5 h of exposure. Oxidative damage to lipids and decreased GSH/GSSG ratio were observed in ROFA-exposed mice as early as 1 h. Afterwards, increased protein oxidation, decreased ascorbic acid content and SOD activity were found in this group at 3 h. The onset of an adaptive response was observed at 5 h after the ROFA exposure, as indicated by decreased TBARS plasma content and increased SOD activity. The observed increase in oxidative damage to plasma macromolecules, together with systemic antioxidants depletion, may be a consequence of a systemic inflammatory response triggered by the ROFA exposure, since increased TNF-α and IL-6 plasma levels and polymorphonuclear leukocytes activation was found at every evaluated time point. These findings contribute to the understanding of the increase in cardiovascular morbidity and mortality, in association with environmental PM inhalation. - Highlights: • An acute exposure to ROFA triggers the occurrence of systemic oxidative stress. • Changes in plasmatic oxidative stress markers appear as early as 1 h after exposure. • ROFA induces proinflammatory cytokines release and intravascular leukocyte activation. • PMN

A simulation study to quantify the impacts of exposure measurement error on air pollution health risk estimates in copollutant time-series models.

Science.gov (United States)

Dionisio, Kathie L; Chang, Howard H; Baxter, Lisa K

2016-11-25

Exposure measurement error in copollutant epidemiologic models has the potential to introduce bias in relative risk (RR) estimates. A simulation study was conducted using empirical data to quantify the impact of correlated measurement errors in time-series analyses of air pollution and health. ZIP-code level estimates of exposure for six pollutants (CO, NO x , EC, PM 2.5 , SO 4 , O 3 ) from 1999 to 2002 in the Atlanta metropolitan area were used to calculate spatial, population (i.e. ambient versus personal), and total exposure measurement error. Empirically determined covariance of pollutant concentration pairs and the associated measurement errors were used to simulate true exposure (exposure without error) from observed exposure. Daily emergency department visits for respiratory diseases were simulated using a Poisson time-series model with a main pollutant RR = 1.05 per interquartile range, and a null association for the copollutant (RR = 1). Monte Carlo experiments were used to evaluate the impacts of correlated exposure errors of different copollutant pairs. Substantial attenuation of RRs due to exposure error was evident in nearly all copollutant pairs studied, ranging from 10 to 40% attenuation for spatial error, 3-85% for population error, and 31-85% for total error. When CO, NO x or EC is the main pollutant, we demonstrated the possibility of false positives, specifically identifying significant, positive associations for copollutants based on the estimated type I error rate. The impact of exposure error must be considered when interpreting results of copollutant epidemiologic models, due to the possibility of attenuation of main pollutant RRs and the increased probability of false positives when measurement error is present.

Low-level arsenic exposure via drinking water consumption and female fecundity - A preliminary investigation.

Science.gov (United States)

Susko, Michele L; Bloom, Michael S; Neamtiu, Iulia A; Appleton, Allison A; Surdu, Simona; Pop, Cristian; Fitzgerald, Edward F; Anastasiu, Doru; Gurzau, Eugen S

2017-04-01

High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timiṣ County, Romania. Women (n=94) with planned pregnancies of 5-20 weeks gestation completed a comprehensive physician-administered study questionnaire and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women. For example, 1µg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P=0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study. Copyright © 2016 Elsevier Inc. All rights reserved.

γ-ray induced chromosome aberration in rabbit peripheral blood lymphocytes irradiated in partial and whole body and decline of aberration rate with time post-exposure

International Nuclear Information System (INIS)

Zhang Lianzhen; Deng Zhicheng; Wang Haiyan

1997-01-01

Te author presents the results of study on 60 Co γ-ray induced chromosome aberration in rabbits peripheral blood lymphocytes irradiated in partial and whole body and the aberration rate decrease with the time of post-exposure. The experiments included 5 groups, it was whole-body exposure group, partial-body exposure (abdomen and pelvic cavity) group, blood irradiation group in vitro and control group respectively. Radiation dose was 3.0 Gy delivered at rate of 0.5 Gy/min. The results show that it was no significant differences between whole body and in blood irradiation group. The chromosome aberration yield in whole body exposure group was higher than that in partial-body group and in the abdomen exposure group was higher than in that in the pelvic cavity irradiation; The chromosome aberration rate decreased with the time of post-exposure in partial and whole body by γ-ray irradiation

Inattentional blindness is influenced by exposure time not motion speed.

Science.gov (United States)

Kreitz, Carina; Furley, Philip; Memmert, Daniel

2016-01-01

Inattentional blindness is a striking phenomenon in which a salient object within the visual field goes unnoticed because it is unexpected, and attention is focused elsewhere. Several attributes of the unexpected object, such as size and animacy, have been shown to influence the probability of inattentional blindness. At present it is unclear whether or how the speed of a moving unexpected object influences inattentional blindness. We demonstrated that inattentional blindness rates are considerably lower if the unexpected object moves more slowly, suggesting that it is the mere exposure time of the object rather than a higher saliency potentially induced by higher speed that determines the likelihood of its detection. Alternative explanations could be ruled out: The effect is not based on a pop-out effect arising from different motion speeds in relation to the primary-task stimuli (Experiment 2), nor is it based on a higher saliency of slow-moving unexpected objects (Experiment 3).

Predicting personal exposure to airborne carbonyls using residential measurements and time/activity data

Science.gov (United States)

Liu, Weili; Zhang, Junfeng (Jim); Korn, Leo R.; Zhang, Lin; Weisel, Clifford P.; Turpin, Barbara; Morandi, Maria; Stock, Tom; Colome, Steve

As a part of the Relationships of Indoor, Outdoor, and Personal Air (RIOPA) study, 48 h integrated residential indoor, outdoor, and personal exposure concentrations of 10 carbonyls were simultaneously measured in 234 homes selected from three US cities using the Passive Aldehydes and Ketones Samplers (PAKS). In this paper, we examine the feasibility of using residential indoor concentrations to predict personal exposures to carbonyls. Based on paired t-tests, the means of indoor concentrations were not different from those of personal exposure concentrations for eight out of the 10 measured carbonyls, indicating indoor carbonyls concentrations, in general, well predicted the central tendency of personal exposure concentrations. In a linear regression model, indoor concentrations explained 47%, 55%, and 65% of personal exposure variance for formaldehyde, acetaldehyde, and hexaldehyde, respectively. The predictability of indoor concentrations on cross-individual variability in personal exposure for the other carbonyls was poorer, explainingexposure concentrations. It was found that activities related to driving a vehicle and performing yard work had significant impacts on personal exposures to a few carbonyls.

Efficacy of serotonin in lessening radiation damage to mouse embryo depending on time of its administration following radiation exposure

International Nuclear Information System (INIS)

Konstantinova, M.M.; Dontsova, G.V.; Panaeva, S.V.; Turpaev, T.M.

1994-01-01

Our earlier studies demonstrated that serotonin lessons radiation damage to an 8-day mouse embryo. Moreover, this biogenic amine was equally effective when administered before and after intrauterine exposure of the embryo to ionizing radiation. The radiotherapeutic effect of serotonin was manifested by disorders in the embryo growth of various intensity, within the range of the studied radiation doses (1.31, 1.74, and 2.18 Gy). The therapeutic effect of serotonin in the embryos exposed to various doses of radiation depended on the amount of serotonin administered. The effective doses of this substance were determined by the severity of the damage inflicted. In this series of experiments, serotonin was administered immediately after exposure to ionizing radiation. The object of the present study was to determine whether or not the radiotherapeutic effect of serotonin depends on the time that elapses between the end of radiation exposure and the administration of serotonin to pregnant mice. It was established that serotonin produces a radiotherapeutic effect during 24 h following the intrauterine exposure of the fetus to ionizing radiation on the 8th day of gestation. The best therapeutic effect is attained with the administration of serotonin immediately after radiation exposure. The effect is slightly lower is serotonin is administered within 5 or 24 h following radiation exposure

Non parametric denoising methods based on wavelets: Application to electron microscopy images in low exposure time

International Nuclear Information System (INIS)

Soumia, Sid Ahmed; Messali, Zoubeida; Ouahabi, Abdeldjalil; Trepout, Sylvain; Messaoudi, Cedric; Marco, Sergio

2015-01-01

The 3D reconstruction of the Cryo-Transmission Electron Microscopy (Cryo-TEM) and Energy Filtering TEM images (EFTEM) hampered by the noisy nature of these images, so that their alignment becomes so difficult. This noise refers to the collision between the frozen hydrated biological samples and the electrons beam, where the specimen is exposed to the radiation with a high exposure time. This sensitivity to the electrons beam led specialists to obtain the specimen projection images at very low exposure time, which resulting the emergence of a new problem, an extremely low signal-to-noise ratio (SNR). This paper investigates the problem of TEM images denoising when they are acquired at very low exposure time. So, our main objective is to enhance the quality of TEM images to improve the alignment process which will in turn improve the three dimensional tomography reconstructions. We have done multiple tests on special TEM images acquired at different exposure time 0.5s, 0.2s, 0.1s and 1s (i.e. with different values of SNR)) and equipped by Golding beads for helping us in the assessment step. We herein, propose a structure to combine multiple noisy copies of the TEM images. The structure is based on four different denoising methods, to combine the multiple noisy TEM images copies. Namely, the four different methods are Soft, the Hard as Wavelet-Thresholding methods, Bilateral Filter as a non-linear technique able to maintain the edges neatly, and the Bayesian approach in the wavelet domain, in which context modeling is used to estimate the parameter for each coefficient. To ensure getting a high signal-to-noise ratio, we have guaranteed that we are using the appropriate wavelet family at the appropriate level. So we have chosen âĂIJsym8âĂİ wavelet at level 3 as the most appropriate parameter. Whereas, for the bilateral filtering many tests are done in order to determine the proper filter parameters represented by the size of the filter, the range parameter and the

The impact of the developmental timing of trauma exposure on PTSD symptoms and psychosocial functioning among older adults.

Science.gov (United States)

Ogle, Christin M; Rubin, David C; Siegler, Ilene C

2013-11-01

The present study examined the impact of the developmental timing of trauma exposure on posttraumatic stress disorder (PTSD) symptoms and psychosocial functioning in a large sample of community-dwelling older adults (N = 1,995). Specifically, we investigated whether the negative consequences of exposure to traumatic events were greater for traumas experienced during childhood, adolescence, young adulthood, midlife, or older adulthood. Each of these developmental periods is characterized by age-related changes in cognitive and social processes that may influence psychological adjustment following trauma exposure. Results revealed that older adults who experienced their currently most distressing traumatic event during childhood exhibited more severe symptoms of PTSD and lower subjective happiness compared with older adults who experienced their most distressing trauma after the transition to adulthood. Similar findings emerged for measures of social support and coping ability. The differential effects of childhood compared with later life traumas were not fully explained by differences in cumulative trauma exposure or by differences in the objective and subjective characteristics of the events. Our findings demonstrate the enduring nature of traumatic events encountered early in the life course and underscore the importance of examining the developmental context of trauma exposure in investigations of the long-term consequences of traumatic experiences.

The impact of life stress on adult depression and anxiety is dependent on gender and timing of exposure.

Science.gov (United States)

Herbison, Carly E; Allen, Karina; Robinson, Monique; Newnham, John; Pennell, Craig

2017-10-01

There is debate about the relative importance of timing of stressful events prenatally and over the life course and risk for subsequent depressive/anxious illness. The aim of this study was to examine the relative roles of prenatal stress and postnatal stress trajectories in predicting depression and anxiety in early adulthood in males and females. Exposure to life stress events was examined in the Western Australian Pregnancy Cohort (Raine) Study during pregnancy and ages 1, 2, 3, 5, 8, 10, 14, and 17 years. At age 20, offspring completed the Depression Anxiety Stress Scale. Prenatal stress and trajectories of stress events from age 1 to 17 were analyzed in linear regression analyses. Five postnatal stress trajectories were identified. In females, medium to high chronic stress exposure or exposure during puberty/adolescence predicted depression and anxiety symptoms while low or reduced stress exposure over the life course did not, after adjustment for relevant confounders. High stress early in pregnancy contributed to male depression/anxiety symptoms independent of postnatal stress trajectory. In females, postnatal stress trajectory was more important than prenatal stress in predicting depression/anxiety symptoms. Interventions focused on reducing and managing stress events around conception/pregnancy and exposure to chronic stress are likely to have beneficial outcomes on rates of depression and anxiety in adults.

Shorter Leukocyte Telomere Length in Relation to Presumed Nonalcoholic Fatty Liver Disease in Mexican-American Men in NHANES 1999–2002

Directory of Open Access Journals (Sweden)

Janet M. Wojcicki

2017-01-01

Full Text Available Leukocyte telomere length is shorter in response to chronic disease processes associated with inflammation such as diabetes mellitus and coronary artery disease. Data from the National Health and Nutrition Examination Survey (NHANES from 1999 to 2002 was used to explore the relationship between leukocyte telomere length and presumed NAFLD, as indicated by elevated serum alanine aminotransferase (ALT levels, obesity, or abdominal obesity. Logistic regression models were used to evaluate the relationship between telomere length and presumed markers of NAFLD adjusting for possible confounders. There was no relationship between elevated ALT levels, abdominal obesity, or obesity and telomere length in adjusted models in NHANES (OR 1.13, 95% CI 0.48–2.65; OR 1.17, 95% CI 0.52–2.62, resp.. Mexican-American men had shorter telomere length in relation to presumed NAFLD (OR 0.07, 95% CI 0.006–0.79 and using different indicators of NAFLD (OR 0.012, 95% CI 0.0006–0.24. Mexican origin with presumed NAFLD had shorter telomere length than men in other population groups. Longitudinal studies are necessary to evaluate the role of telomere length as a potential predictor to assess pathogenesis of NALFD in Mexicans.

Polycyclic aromatic hydrocarbons (PAHs) skin permeation rates change with simultaneous exposures to solar ultraviolet radiation (UV-S).

Science.gov (United States)

Hopf, Nancy B; Spring, Philipp; Hirt-Burri, Nathalie; Jimenez, Silvia; Sutter, Benjamin; Vernez, David; Berthet, Aurelie

2018-05-01

Road construction workers are simultaneously exposed to two carcinogens; solar ultraviolet (UV-S) radiation and polycyclic aromatic hydrocarbons (PAHs) in bitumen emissions. The combined exposure may lead to photogenotoxicity and enhanced PAH skin permeation rates. Skin permeation rates (J) for selected PAHs in a mixture (PAH-mix) or in bitumen fume condensate (BFC) with and without UV-S co-exposures were measured with in vitro flow-through diffusion cells mounted with human viable skin and results compared. Possible biomarkers were explored. Js were greater with UV-S for naphthalene, anthracene, and pyrene in BFC (0.08-0.1 ng/cm 2 /h) compared to without (0.02-0.26 ng/cm 2 /h). This was true for anthracene, pyrene, and chrysene in the PAH-mix. Naphthalene and benzo(a)pyrene (BaP) in the PAH-mix had greater Js without (0.97-13.01 ng/cm 2 /h) compared to with UV-S (0.40-6.35 ng/cm 2 /h). Time until permeation (T lags ) in the PAH-mix were generally shorter compared to the BFC, and they ranged from 1 to 13 h. The vehicle matrix could potentially be the reason for this discrepancy as BFC contains additional not identified substances. Qualitative interpretation of p53 suggested a dose-response with UV-S, and somewhat with the co-exposures. MMP1, p65 and cKIT were not exploitable. Although not statistically different, PAHs permeate human viable skin faster with simultaneous exposures to UV. Copyright © 2018 Elsevier B.V. All rights reserved.

Visceral leishmaniasis relapse hazard is linked to reduced miltefosine exposure in patients from Eastern Africa: a population pharmacokinetic/pharmacodynamic study.

Science.gov (United States)

Dorlo, Thomas P C; Kip, Anke E; Younis, Brima M; Ellis, Sally J; Alves, Fabiana; Beijnen, Jos H; Njenga, Simon; Kirigi, George; Hailu, Asrat; Olobo, Joseph; Musa, Ahmed M; Balasegaram, Manica; Wasunna, Monique; Karlsson, Mats O; Khalil, Eltahir A G

2017-11-01

Low efficacy of miltefosine in the treatment of visceral leishmaniasis was recently observed in Eastern Africa. To describe the pharmacokinetics and establish a pharmacokinetic/pharmacodynamic relationship for miltefosine in Eastern African patients with visceral leishmaniasis, using a time-to-event approach to model relapse of disease. Miltefosine plasma concentrations from 95 patients (48 monotherapy versus 47 combination therapy) were included in the population pharmacokinetic model using non-linear mixed effects modelling. Subsequently a time-to-event model was developed to model the time of clinical relapse. Various summary pharmacokinetic parameters (various AUCs, Time > EC50, Time > EC90), normalized within each treatment arm to allow simultaneous analysis, were evaluated as relapse hazard-changing covariates. A two-compartment population model with first-order absorption fitted the miltefosine pharmacokinetic data adequately. Relative bioavailability was reduced (-74%, relative standard error 4.7%) during the first week of treatment of the monotherapy arm but only the first day of the shorter combination regimen. Time to the relapse of infection could be described using a constant baseline hazard (baseline 1.8 relapses/year, relative standard error 72.7%). Miltefosine Time > EC90 improved the model significantly when added in a maximum effect function on the baseline hazard (half maximal effect with Time > EC90 6.97 days for monotherapy). Miltefosine drug exposure was found to be decreased in Eastern African patients with visceral leishmaniasis, due to a (transient) initial lower bioavailability. Relapse hazard was inversely linked to miltefosine exposure. Significantly lower miltefosine exposure was observed in children compared with adults, further urging the need for implementation of dose adaptations for children. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.

Exposure to aged crumb rubber reduces survival time during a stress test in earthworms (Eisenia fetida).

Science.gov (United States)

Pochron, Sharon; Nikakis, Jacqueline; Illuzzi, Kyra; Baatz, Andrea; Demirciyan, Loriana; Dhillon, Amritjot; Gaylor, Thomas; Manganaro, Alexa; Maritato, Nicholas; Moawad, Michael; Singh, Rajwinder; Tucker, Clara; Vaughan, Daniel

2018-04-01

Solid waste management struggles with the sustainable disposal of used tires. One solution involves shredding used tires into crumb rubber and using the material as infill for artificial turf. However, crumb rubber contains hydrocarbons, organic compounds, and heavy metals, and it travels into the environment. Earthworms living in soil contaminated with virgin crumb rubber gained 14% less body weight than did earthworms living in uncontaminated soil, but the impact of aged crumb rubber on the earthworms is unknown. Since many athletic fields contain aged crumb rubber, we compared the body weight, survivorship, and longevity in heat and light stress for earthworms living in clean topsoil to those living in topsoil contaminated with aged crumb rubber. We also characterized levels of metals, nutrients, and micronutrients of both soil treatments and compared those to published values for soil contaminated with virgin crumb rubber. Consistent with earlier research, we found that contaminated soil did not inhibit microbial respiration rates. Aged crumb rubber, like new crumb rubber, had high levels of zinc. However, while exposure to aged crumb rubber did not reduce earthworm body weight as did exposure to new crumb rubber, exposure to aged crumb rubber reduced earthworm survival time during a stress test by a statistically significant 38 min (16.2%) relative to the survival time for worms that had lived in clean soil. Aged crumb rubber and new crumb rubber appear to pose similar toxic risks to earthworms. This study suggests an environmental cost associated with the current tire-recycling solution.

Time versus frequency domain measurements: layered model ...

African Journals Online (AJOL)

... their high frequency content while among TEM data sets with low frequency content, the averaging times for the FEM ellipticity were shorter than the TEM quality. Keywords: ellipticity, frequency domain, frequency electromagnetic method, model parameter, orientation error, time domain, transient electromagnetic method

Bright Light Delights: Effects of Daily Light Exposure on Emotions, Restactivity Cycles, Sleep and Melatonin Secretion in Severely Demented Patients.

Science.gov (United States)

Münch, Mirjam; Schmieder, Michael; Bieler, Katharina; Goldbach, Rolf; Fuhrmann, Timo; Zumstein, Naomi; Vonmoos, Petra; Scartezzini, Jean-Louis; Wirz-Justice, Anna; Cajochen, Christian

2017-01-01

We tested whether the effects of a dynamic lighting system are superior to conventional lighting on emotions, agitation behaviour, quality of life, melatonin secretion and circadian restactivity cycles in severely demented patients. As a comparison, an age matched control patient group was exposed to conventional lighting. For none of the output measures were significant differences between the two lighting conditions found during the 8 study weeks in fall/winter. Thus, we divided the patient cohort (n = 89) into two groups, solely based on the median of their daily individual light exposure. Patients with higher average daily light exposure (>417 lx) showed significantly longer emotional expressions of pleasure and alertness per daily observations than patients with lower daily light exposure. Moreover, they had a higher quality of life, spent less time in bed, went to bed later and initiated their sleep episodes later, even though the two groups did not differ with respect to age, severity of cognitive impairment and mobility. In general, men were more agitated, had shorter sleep with more wake episodes, had a lower circadian amplitude of relative rest-wake activity and interdaily circadian stability than women. In particular, lower daily light exposures significantly predicted lower circadian amplitudes of rest-activity cycles in men but not in women. This may indicate sex specific susceptibility to daily light exposures for rest-activity regulation in older demented patients. Our results provide evidence that a higher daily light exposure has beneficial effects on emotions and thus improved quality of life in a severely demented patient group. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Virtual reality exposure therapy

OpenAIRE

Rothbaum, BO; Hodges, L; Kooper, R

1997-01-01

It has been proposed that virtual reality (VR) exposure may be an alternative to standard in vivo exposure. Virtual reality integrates real-time computer graphics, body tracking devices, visual displays, and other sensory input devices to immerse a participant in a computer- generated virtual environment. Virtual reality exposure is potentially an efficient and cost-effective treatment of anxiety disorders. VR exposure therapy reduced the fear of heights in the first control...

Computing transient exposure to indoor pollutants

International Nuclear Information System (INIS)

Owczarski, P.C.; Parker, G.B.

1983-03-01

A computer code, CORRAL, is used to compute the transient levels of gases and respirable particulates in a residence. Predictions of time-varying exposure to radon (from the outside air, soil and well water) and respirable particulates (from outside air, wood stove operation and cigarette smoke) for a mother and child over 24 hours are made. Average 24-hour radon exposures are 13 times background (0.75 pCi/l) for the child and 4.5 times background for the mother. Average 24-hour respirable particulate exposures are 5.6 times background (100 μg/m 3 ) for the mother and 4.2 times background for the child. The controlling parameters examined are source location, flow rates between rooms, air infiltration rate and lifestyle. The first three are shown to influence the formation of local pockets of high concentration of radon and particulates, and the last parameter shows that lifestyle patterns ultimately govern individual exposure to these pockets of high concentrations. The code is useful for examination of mitigation measures to reduce exposure and examination of the effects that the controlling parameters have on exposure to indoor pollutants

The uncertain first-time voter: Effects of political media exposure on young citizens’ formation of vote choice in a digital media environment

DEFF Research Database (Denmark)

Ohme, Jakob; de Vreese, Claes Holger; Albæk, Erik

2018-01-01

The digital media environment changes the way citizens receive political information, also during an election campaign. Particularly first-time voters increasingly use social media platforms as news sources. Yet, it is less clear how accessing political information in such a unique social setting...... exposure and certainty can be mediated by active campaign participation. An 11-wave national panel study was conducted, using a smartphone-based assessment of citizens’ (n = 1108) media exposure and vote choice certainty across the campaign period. Results suggest that first-time voters’ social media...... affects these cohorts’ decision-making processes during an election campaign, compared to experienced voters. We compare effects of these two groups’ political information exposure on their vote choice certainty during the 2015 Danish national election. We furthermore test how the relation between...

Development of a Job-Exposure Matrix (AsbJEM) to Estimate Occupational Exposure to Asbestos in Australia.

Science.gov (United States)

van Oyen, Svein C; Peters, Susan; Alfonso, Helman; Fritschi, Lin; de Klerk, Nicholas H; Reid, Alison; Franklin, Peter; Gordon, Len; Benke, Geza; Musk, Arthur W

2015-07-01

Occupational exposure data on asbestos are limited and poorly integrated in Australia so that estimates of disease risk and attribution of disease causation are usually calculated from data that are not specific for local conditions. To develop a job-exposure matrix (AsbJEM) to estimate occupational asbestos exposure levels in Australia, making optimal use of the available exposure data. A dossier of all available exposure data in Australia and information on industry practices and controls was provided to an expert panel consisting of three local industrial hygienists with thorough knowledge of local and international work practices. The expert panel estimated asbestos exposures for combinations of occupation, industry, and time period. Intensity and frequency grades were estimated to enable the calculation of annual exposure levels for each occupation-industry combination for each time period. Two indicators of asbestos exposure intensity (mode and peak) were used to account for different patterns of exposure between occupations. Additionally, the probable type of asbestos fibre was determined for each situation. Asbestos exposures were estimated for 537 combinations of 224 occupations and 60 industries for four time periods (1943-1966; 1967-1986; 1987-2003; ≥2004). Workers in the asbestos manufacturing, shipyard, and insulation industries were estimated to have had the highest average exposures. Up until 1986, 46 occupation-industry combinations were estimated to have had exposures exceeding the current Australian exposure standard of 0.1 f ml(-1). Over 90% of exposed occupations were considered to have had exposure to a mixture of asbestos varieties including crocidolite. The AsbJEM provides empirically based quantified estimates of asbestos exposure levels for Australian jobs since 1943. This exposure assessment application will contribute to improved understanding and prediction of asbestos-related diseases and attribution of disease causation. © The

Inhibition of cancer cell growth by exposure to a specific time-varying electromagnetic field involves T-type calcium channels.

Directory of Open Access Journals (Sweden)

Carly A Buckner

Full Text Available Electromagnetic field (EMF exposures affect many biological systems. The reproducibility of these effects is related to the intensity, duration, frequency, and pattern of the EMF. We have shown that exposure to a specific time-varying EMF can inhibit the growth of malignant cells. Thomas-EMF is a low-intensity, frequency-modulated (25-6 Hz EMF pattern. Daily, 1 h, exposures to Thomas-EMF inhibited the growth of malignant cell lines including B16-BL6, MDA-MB-231, MCF-7, and HeLa cells but did not affect the growth of non-malignant cells. Thomas-EMF also inhibited B16-BL6 cell proliferation in vivo. B16-BL6 cells implanted in syngeneic C57b mice and exposed daily to Thomas-EMF produced smaller tumours than in sham-treated controls. In vitro studies showed that exposure of malignant cells to Thomas-EMF for > 15 min promoted Ca(2+ influx which could be blocked by inhibitors of voltage-gated T-type Ca(2+ channels. Blocking Ca(2+ uptake also blocked Thomas-EMF-dependent inhibition of cell proliferation. Exposure to Thomas-EMF delayed cell cycle progression and altered cyclin expression consistent with the decrease in cell proliferation. Non-malignant cells did not show any EMF-dependent changes in Ca(2+ influx or cell growth. These data confirm that exposure to a specific EMF pattern can affect cellular processes and that exposure to Thomas-EMF may provide a potential anti-cancer therapy.

Inhibition of cancer cell growth by exposure to a specific time-varying electromagnetic field involves T-type calcium channels.

Science.gov (United States)

Buckner, Carly A; Buckner, Alison L; Koren, Stan A; Persinger, Michael A; Lafrenie, Robert M

2015-01-01

Electromagnetic field (EMF) exposures affect many biological systems. The reproducibility of these effects is related to the intensity, duration, frequency, and pattern of the EMF. We have shown that exposure to a specific time-varying EMF can inhibit the growth of malignant cells. Thomas-EMF is a low-intensity, frequency-modulated (25-6 Hz) EMF pattern. Daily, 1 h, exposures to Thomas-EMF inhibited the growth of malignant cell lines including B16-BL6, MDA-MB-231, MCF-7, and HeLa cells but did not affect the growth of non-malignant cells. Thomas-EMF also inhibited B16-BL6 cell proliferation in vivo. B16-BL6 cells implanted in syngeneic C57b mice and exposed daily to Thomas-EMF produced smaller tumours than in sham-treated controls. In vitro studies showed that exposure of malignant cells to Thomas-EMF for > 15 min promoted Ca(2+) influx which could be blocked by inhibitors of voltage-gated T-type Ca(2+) channels. Blocking Ca(2+) uptake also blocked Thomas-EMF-dependent inhibition of cell proliferation. Exposure to Thomas-EMF delayed cell cycle progression and altered cyclin expression consistent with the decrease in cell proliferation. Non-malignant cells did not show any EMF-dependent changes in Ca(2+) influx or cell growth. These data confirm that exposure to a specific EMF pattern can affect cellular processes and that exposure to Thomas-EMF may provide a potential anti-cancer therapy.

Experimental Constraints of the Exotic Shearing of Space-Time

Energy Technology Data Exchange (ETDEWEB)

Richardson, Jonathan William [Univ. of Chicago, IL (United States)

2016-08-01

The Holometer program is a search for rst experimental evidence that space-time has quantum structure. The detector consists of a pair of co-located 40-m power-recycled interferometers whose outputs are read out synchronously at 50 MHz, achieving sensitivity to spatiallycorrelated uctuations in dierential position on time scales shorter than the light-crossing time of the instruments. Unlike gravitational wave interferometers, which time-resolve transient geometrical disturbances in the spatial background, the Holometer is searching for a universal, stationary quantization noise of the background itself. This dissertation presents the nal results of the Holometer Phase I search, an experiment congured for sensitivity to exotic coherent shearing uctuations of space-time. Measurements of high-frequency cross-spectra of the interferometer signals obtain sensitivity to spatially-correlated eects far exceeding any previous measurement, in a broad frequency band extending to 7.6 MHz, twice the inverse light-crossing time of the apparatus. This measurement is the statistical aggregation of 2.1 petabytes of 2-byte dierential position measurements obtained over a month-long exposure time. At 3 signicance, it places an upper limit on the coherence scale of spatial shear two orders of magnitude below the Planck length. The result demonstrates the viability of this novel spatially-correlated interferometric detection technique to reach unprecedented sensitivity to coherent deviations of space-time from classicality, opening the door for direct experimental tests of theories of relational quantum gravity.

Intrauterine Exposure to Maternal Stress Alters Bdnf IV DNA Methylation and Telomere Length in the Brain of Adult Rat Offspring

Science.gov (United States)

Blaze, Jennifer; Asok, Arun; Borrelli, Kristyn; Tulbert, Christine; Bollinger, Justin; Ronca Finco, April E.; Roth, Tania L.

2017-01-01

DNA methylation (addition of methyl groups to cytosines which normally represses gene transcription) and changes in telomere length (TTAGGG repeats on the ends of chromosomes) are two molecular modifications that result from stress and could contribute to the long-term effects of intrauterine exposure to maternal stress on offspring behavioral outcomes. Here, we measured methylation of Brain-derived neurotrophic factor (Bdnf), a gene important in development and plasticity, and telomere length in the brains of adult rat male and female offspring whose mothers were exposed to unpredictable and variable stressors throughout gestation. Males exposed to prenatal stress had greater methylation (Bdnf IV) in the medial prefrontal cortex (mPFC) compared to non-stressed controls. Further, prenatally-stressed males had shorter telomeres than controls in the mPFC. This study provides the first evidence in a rodent model of an association between prenatal stress exposure and subsequent shorter brain telomere length. Together findings indicate a long-term impact of prenatal stress on DNA methylation and telomere biology with relevance for behavioral and health outcomes, and contribute to a growing literature linking stress to intergenerational epigenetic alterations and changes in telomere length.

Birth outcomes and background exposures to select elements, the Longitudinal Investigation of Fertility and the Environment (LIFE).

Science.gov (United States)

Bloom, Michael S; Buck Louis, Germaine M; Sundaram, Rajeshwari; Maisog, Jose M; Steuerwald, Amy J; Parsons, Patrick J

2015-04-01

Evidence suggests that trace exposures to select elements may increase the risk for adverse birth outcomes. To investigate further, we used multiple regression to assess associations between preconception parental exposures to Pb, Cd, and total Hg in blood, and 21 elements in urine, with n=235 singleton birth outcomes, adjusted for confounders and partner's exposure. Earlier gestational age at delivery (GA) was associated with higher tertiles of urine maternal W (-1.22 days) and paternal U (-1.07 days), but GA was later for higher tertiles of maternal (+1.11 days) and paternal (+1.30 days) blood Hg. Additional analysis indicated shorter GA associated with higher paternal urine Ba, W, and U, and with higher maternal blood Pb for boys, but GA was longer in association with higher maternal urine Cr. Birth weight (BW) was lower for higher tertiles of paternal urine Cs (-237.85g), U (-187.34g), and Zn (-209.08g), and for higher continuous Cr (P=0.021). In contrast, BW was higher for higher tertiles of paternal urine As (+194.71g) and counterintuitively for maternal blood Cd (+178.52g). Birth length (BL) was shorter for higher tertiles of urine maternal W (-1.22cm) and paternal U (-1.10cm). Yet, higher tertiles of maternal (+1.11cm) and paternal (+1.30) blood Hg were associated with longer BL. Head circumference at delivery was lower for higher tertiles of paternal urine U (-0.83cm), and for higher continuous Mo in boys (-0.57cm). Overall, associations were most consistently indicated for GA and measures of birth size with urine W and U, and paternal exposures were more frequently associated than maternal. Though limited by several factors, ours is the largest multi-element investigation of prospective couple-level trace exposures and birth outcomes to date; the novel observations for W and U merit further investigation. Copyright © 2015 Elsevier Inc. All rights reserved.

A comparison of Reduced Life Expectancy (RLE) model with Haber's Rule to describe effects of exposure time on toxicity

International Nuclear Information System (INIS)

Verma, Vibha; Yu, Qiming J.; Connell, Des W.

2015-01-01

The Reduced Life Expectancy (RLE) Model (LC 50  = [ln(NLE) – ln(LT 50 )]/d) has been proposed as an alternative to Haber's Rule. The model is based on a linear relationship between LC 50 (Lethal Exposure Concentration) and lnLT 50 (Lethal Exposure Time) and uses NLE (Normal Life Expectancy) as a limiting point as well as a long term data point (where d is a constant). The purposes of this paper were to compare the RLE Model with Haber's Rule with available toxicity data and to evaluate the strengths and weaknesses of each approach. When LT 50 is relatively short and LC 50 is high, Haber's Rule is consistent with the RLE model. But the difference between the two was evident in the situation when LT 50 is relatively long and LC 50 is low where the RLE model is a marked departure from Haber's Rule. The RLE Model can be used to appropriately evaluate long term effects of exposure. - Highlights: • The strength and weakness of Haber's Rule in relation to the RLE model is needed. • Haber's Rule now used universally is quite inappropriate for environmental toxicity. • Normal life expectancy, a new parameter l is used to evaluate effects of exposure time on toxicity. • According to RLE model when LC 50 approaches zero, then LT 50  = Normal Life Expectancy. • The RLE model can be used to evaluate long term effects of exposure-accurately and easily. - The RLE approach is a more appropriate alternative particularly to evaluate long term effects of exposure. It can be easily used to estimate long term effects of exposure

Is Alcohol Use Disorder Identification Test (AUDIT or its shorter versions more useful to identify risky drinkers in a Chinese population? A diagnostic study.

Directory of Open Access Journals (Sweden)

Benjamin H K Yip

Full Text Available To examine the diagnostic performance of shorter versions of Alcohol Use Disorder Identification Test (AUDIT, including Alcohol Consumption (AUDIT-C, in identifying risky drinkers in primary care settings using conventional performance measures, supplemented by decision curve analysis and reclassification table.A cross-sectional study of adult males in general outpatient clinics in Hong Kong. The study included only patients who reported at least sometimes drinking alcoholic beverages. Timeline follow back alcohol consumption assessment method was used as the reference standard. A Chinese translated and validated 10-item AUDIT (Ch-AUDIT was used as a screening tool of risky drinking.Of the participants, 21.7% were classified as risky drinkers. AUDIT-C has the best overall performance among the shorter versions of Ch-AUDIT. The AUC of AUDIT-C was comparable to Ch-AUDIT (0.898 vs 0.901, p-value = 0.959. Decision curve analysis revealed that when the threshold probability ranged from 15-30%, the AUDIT-C had a higher net-benefit than all other screens. AUDIT-C improved the reclassification of risky drinking when compared to Ch-AUDIT (net reclassification improvement = 0.167. The optimal cut-off of AUDIT-C was at ≥5.Given the rising levels of alcohol consumption in the Chinese regions, this Chinese translated 3-item instrument provides convenient and time-efficient risky drinking screening and may become an increasingly useful tool.

Increased traffic exposure and negative birth outcomes: a prospective cohort in Australia

Directory of Open Access Journals (Sweden)

Wilson Lee-Ann

2011-04-01

Full Text Available Abstract Background Pregnant women exposed to traffic pollution have an increased risk of negative birth outcomes. We aimed to investigate the size of this risk using a prospective cohort of 970 mothers and newborns in Logan, Queensland. Methods We examined two measures of traffic: distance to nearest road and number of roads around the home. To examine the effect of distance we used the number of roads around the home in radii from 50 to 500 metres. We examined three road types: freeways, highways and main roads. Results There were no associations with distance to road. A greater number of freeways and main roads around the home were associated with a shorter gestation time. There were no negative impacts on birth weight, birth length or head circumference after adjusting for gestation. The negative effects on gestation were largely due to main roads within 400 metres of the home. For every 10 extra main roads within 400 metres of the home, gestation time was reduced by 1.1% (95% CI: -1.7, -0.5; p-value = 0.001. Conclusions Our results add weight to the association between exposure to traffic and reduced gestation time. This effect may be due to the chemical toxins in traffic pollutants, or because of disturbed sleep due to traffic noise.

The brain is a target organ after acute exposure to depleted uranium

International Nuclear Information System (INIS)

Lestaevel, P.; Houpert, P.; Bussy, C.; Dhieux, B.; Gourmelon, P.; Paquet, F.

2005-01-01

The health effects of depleted uranium (DU) are mainly caused by its chemical toxicity. Although the kidneys are the main target organs for uranium toxicity, uranium can also reach the brain. In this paper, the central effects of acute exposure to DU were studied in relation to health parameters and the sleep-wake cycle of adult rats. Animals were injected intraperitoneally with 144 ± 10 μg DU kg -1 as nitrate. Three days after injection, the amounts of uranium in the kidneys represented 2.6 μg of DU g -1 of tissue, considered as a sub-nephrotoxic dosage. The central effect of uranium could be seen through a decrease in food intake as early as the first day after exposure and shorter paradoxical sleep 3 days after acute DU exposure (-18% of controls). With a lower dosage of DU (70 ± 8 μg DU kg -1 ), no significant effect was observed on the sleep-wake cycle. The present study intends to illustrate the fact that the brain is a target organ, as are the kidneys, after acute exposure to a moderate dosage of DU. The mechanisms by which uranium causes these early neurophysiological perturbations shall be discussed

Cost-effectiveness of longer-term versus shorter-term provision of antibiotics in patients with persistent symptoms attributed to Lyme disease

NARCIS (Netherlands)

Berende, A.; Nieuwenhuis, L.; Hofstede, H.J.M. ter; Vos, F.J.; Vogelaar, M.L.; Tromp, M.A.; Middendorp, H. van; Donders, A.R.T.; Evers, A.W.M.; Kullberg, B.J.; Adang, E.M.M.

2018-01-01

BACKGROUND: The treatment of persistent symptoms attributed to Lyme disease remains controversial. Recently, the PLEASE study did not demonstrate any additional clinical benefit of longer-term versus shorter-term antibiotic treatment. However, the economic impact of the antibiotic strategies has not

Dating of pre-exposure times of lunar rocks and soils

International Nuclear Information System (INIS)

Eugster, O.

1986-01-01

Xenon produced by fission of uranium, thorium and plutonium has repeatedly been observed in lunar rocks and soils. In two basaltic rocks and in two soils Xe was found originating from fission of U-235 induced by neutrons which are due to the interactions of cosmic ray particles with lunar matter. Two facts lead to this conclusion: (1) fission Xe is present in excess of that expected for the U, Th, and Pu concentrations and for the gas retention age of the samples; and (2) the Xe-134/Xe-136 ratio of excess fission Xe is close to 1.25 as expected for neutron induced fission of U-235. Information on the duration of the exposure to cosmic rays was obtained from the Kr-81-Kr systematics whereas the effective shielding conditions were derived from the depth sensitive cosmogenic ratio Xe-131/Xe-126. For the four samples the exposure to cosmic rays in the lunar regolith is described by a two stage exposure model. The history of the four samples was derived in terms of duration and shielding depth of the two stages

Stimulus repetition and the perception of time: the effects of prior exposure on temporal discrimination, judgment, and production.

Directory of Open Access Journals (Sweden)

William J Matthews

Full Text Available It has been suggested that repeated stimuli have shorter subjective duration than novel items, perhaps because of a reduction in the neural response to repeated presentations of the same object. Five experiments investigated the effects of repetition on time perception and found further evidence that immediate repetition reduces apparent duration, consistent with the idea that subjective duration is partly based on neural coding efficiency. In addition, the experiments found (a no effect of repetition on the precision of temporal discrimination, (b that the effects of repetition disappeared when there was a modest lag between presentations, (c that, across participants, the size of the repetition effect correlated with temporal discrimination, and (d that the effects of repetition suggested by a temporal production task were the opposite of those suggested by temporal judgments. The theoretical and practical implications of these results are discussed.

Impact of Indocyanine Green Concentration, Exposure Time, and Degree of Dissolution in Creating Toxic Anterior Segment Syndrome: Evaluation in a Rabbit Model

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Tamer Tandogan

2016-01-01

Full Text Available Purpose. To investigate the role of indocyanine green (ICG dye as a causative material of toxic anterior segment syndrome (TASS in an experimental rabbit model. Method. Eight eyes of four rabbits were allocated to this study. Capsular staining was performed using ICG dye, after which the anterior chamber was irrigated with a balanced salt solution. The effects of different concentrations (control, 0.25, 0.5, and 1.0%, exposure times (10 and 60 seconds, and the degree of dissolution (differently vortexed were investigated. The analysis involved anterior segment photography, ultrasound pachymetry, prostaglandin assay (PGE2 Parameter Assay, R&D systems, Inc., and scanning electron microscopy of each iris. Result. There was no reaction in the control eye. A higher aqueous level of PGE2 and more severe inflammatory reaction were observed in cases of eyes with higher concentration, longer exposure time, and poorly dissolved dye. Additionally, scanning electron microscopy revealed larger and coarser ICG particles. Conclusion. TASS occurrence may be associated with the concentration, exposure time, and degree of dissolution of ICG dye during cataract surgery.

Exposure to nature gardens has time-dependent associations with mood improvements for people with mid- and late-stage dementia: Innovative practice.

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White, Piran Cl; Wyatt, Jonathan; Chalfont, Garuth; Bland, J Martin; Neale, Christopher; Trepel, Dominic; Graham, Hilary

2017-01-01

Exposure to green space and nature has a potential role to play in the care of people with dementia, with possible benefits including improved mood and slower disease progression. In this observational study at a dementia care facility in the UK, we used carer-assessed measures to evaluate change in mood of residents with mid- to late-stage dementia following exposure to a nature garden. We found that exposure to nature was associated with a beneficial change in patient mood. There was a non-linear relationship between time spent outdoors and mood outcome. Improvements in patient mood were associated with relatively short duration exposures to nature, and no additional measureable increases in mood were found with exposures beyond 80-90 minutes duration. Whilst further investigation is required before causality can be determined, these results raise important questions for policy about the integration of outdoor space into the design of dementia care facilities and programmes.

Interstitial lung abnormalities in treatment-naïve advanced non-small-cell lung cancer patients are associated with shorter survival

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Nishino, Mizuki, E-mail: Mizuki_Nishino@DFCI.HARVARD.EDU [Department of Radiology, Brigham and Women' s Hospital, 75 Francis St., Boston, MA 02115 (United States); Department of Imaging, Dana-Farber Cancer Institute, 450 Brookline Ave., Boston, MA 02215 (United States); Cardarella, Stephanie [Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Ave., Boston, MA 02215, (United States); Dahlberg, Suzanne E. [Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, 450 Brookline Ave., Boston, MA 02215 (United States); Araki, Tetsuro [Department of Radiology, Brigham and Women' s Hospital, 75 Francis St., Boston, MA 02115 (United States); Lydon, Christine; Jackman, David M.; Rabin, Michael S. [Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Ave., Boston, MA 02215, (United States); Hatabu, Hiroto [Department of Radiology, Brigham and Women' s Hospital, 75 Francis St., Boston, MA 02115 (United States); Johnson, Bruce E. [Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Ave., Boston, MA 02215, (United States)

2015-05-15

Highlights: • Interstitial lung abnormalities were present in 14% of stage IV NSCLC patients. • ILA was more common in older patients with heavier smoking history. • ILA was associated with shorter survival after adjusting for smoking and therapy. • ILA could be an additional independent marker for survival in advanced NSCLC. - Abstract: Objective: Interstitial lung diseases are associated with increased risk of lung cancer. The prevalence of ILA at diagnosis of advanced non-small-cell lung cancer (NSCLC) and its impact on overall survival (OS) remain to be investigated. Materials and method: The study included 120 treatment-naïve stage IV NSCLC patients (53 males, 67 females). ILA was scored on CT prior to any systemic therapy using a 4-point scale [0 = no evidence of ILA, 1 = equivocal for ILA, 2 = suspicious for ILA, 3 = ILA] by a sequential reading method previously reported. ILA scores of 2 or 3 indicated the presence of ILA. Results: ILA was present in 17 patients (14%) with advanced NSCLC prior to any treatment (score3: n = 2, score2: n = 15). These 17 patients were significantly older (median age: 69 vs. 63, p = 0.04) and had a heavier smoking history (median: 40 vs. 15.5 pack-year, p = 0.003) than those with ILA score 0 or 1. Higher ILA scores were associated with shorter OS (p = 0.001). Median OS of the 17 patients with ILA was 7.2 months [95%CI: 2.9–9.4] compared to 14.8 months [95%CI: 11.1–18.4] in patients with ILA score 0 or 1 (p = 0.002). In a multivariate model, the presence of ILA remained significant for increased risk for death (HR = 2.09, p = 0.028) after adjusting for first-line systemic therapy (chemotherapy, p < 0.001; TKI, p < 0.001; each compared to no therapy) and pack years of smoking (p = 0.40). Conclusion: Radiographic ILA was present in 14% of treatment-naïve advanced NSCLC patients. Higher ILA scores were associated with shorter OS, indicating that ILA could be a marker of shorter survival in advanced NSCLC.

Modeling the effects of exposure time and turbidity on the elimination of bacteria in drinking water by natural ultraviolet radiation

International Nuclear Information System (INIS)

Elkarmi, A.

1998-01-01

Two models are developed in which the effect of exposure time on bacterial elimination from drinking water by natural ultraviolet radiation is modeled as a Gompertz growth curve and the effect of turbidity on the elimination of bacteria in drinking water is modeled as the reciprocal of Gompertz growth curve by using nonlinear regression analysis. The Quasi-Newton estimation procedure in combination with the simplex, Hooke-Jeeves and Rosenbrock methods are used to estimate the model parameters. The results of the two models can assist in determining the appropriate exposure time and turbidity needed to obtain a certain percentage of bacterial elimination to a high degree of accuracy and thus is useful in act ural practical applications. (author) . 13 refs., 6 figs., 2 tabs

Motor response programming and movement time in children with heavy prenatal alcohol exposure.

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Simmons, Roger W; Thomas, Jennifer D; Levy, Susan S; Riley, Edward P

2010-06-01

The present experiment assessed motor response programming and movement time in children with histories of heavy prenatal alcohol exposure (PEA). Alcohol-exposed children between the ages of 7 and 17 years were classified into two groups: Fetal Alcohol Syndrome (FAS: n=9) and children with PEA (PEA: n=19) but who did not have the defining characteristics of FAS. The FAS and PEA children were compared with non-alcohol-exposed children (NC: n=23) when completing two tasks: a simple reaction time task (RT alone condition) and a reaction plus movement task (RT+Move condition). The movement involved responding to an imperative stimulus signal and depressing three target buttons in a set sequence. Participants completed 24 trials each for the RT alone and RT+Move response conditions. Results indicated no significant differences in performance among FAS, PEA, and NC groups during the RT alone condition. However, during the RT+Move condition, the FAS group produced significantly longer and more variable RTs than the PEA and NC groups, which produced comparable RTs. The FAS group also produced significantly slower movement times when moving to all three targets, whereas movement time variability did not significantly differ as a function of group. The observed results indicate children with FAS experience deficits in response programming and movement time production. 2010 Elsevier Inc. All rights reserved.

Preschool Children's Exposure to Media, Technology, and Screen Time: Perspectives of Caregivers from Three Early Childcare Settings

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Sharkins, Kimberly A.; Newton, Allison B.; Albaiz, Najla Essa A.; Ernest, James M.

2016-01-01

Young children are being increasingly exposed to media, technology, and screen time (MeTS) at home and in instructional settings. Little is known about the long-term effects of MeTS and there is a lack of research concerning caregivers' opinions regarding young children's exposure to and utilization of MeTS. Therefore, this study explored the…

Search times and probability of detection in time-limited search

Science.gov (United States)

Wilson, David; Devitt, Nicole; Maurer, Tana

2005-05-01

When modeling the search and target acquisition process, probability of detection as a function of time is important to war games and physical entity simulations. Recent US Army RDECOM CERDEC Night Vision and Electronics Sensor Directorate modeling of search and detection has focused on time-limited search. Developing the relationship between detection probability and time of search as a differential equation is explored. One of the parameters in the current formula for probability of detection in time-limited search corresponds to the mean time to detect in time-unlimited search. However, the mean time to detect in time-limited search is shorter than the mean time to detect in time-unlimited search and the relationship between them is a mathematical relationship between these two mean times. This simple relationship is derived.

Association of established smoking among adolescents with timing of exposure to smoking depicted in movies.

Science.gov (United States)

Primack, Brian A; Longacre, Meghan R; Beach, Michael L; Adachi-Mejia, Anna M; Titus, Linda J; Dalton, Madeline A

2012-04-04

It is not known whether exposure to smoking depicted in movies carries greater influence during early or late adolescence. We aimed to quantify the independent relative contribution to established smoking of exposure to smoking depicted in movies during both early and late adolescence. We prospectively assessed 2049 nonsmoking students recruited from 14 randomly selected public schools in New Hampshire and Vermont. At baseline enrollment, students aged 10-14 years completed a written survey to determine personal, family, and sociodemographic characteristics and exposure to depictions of smoking in the movies (early exposure). Seven years later, we conducted follow-up telephone interviews to ascertain follow-up exposure to movie smoking (late exposure) and smoking behavior. We used multiple regression models to assess associations between early and late exposure and development of established smoking. One-sixth (17.3%) of the sample progressed to established smoking. In analyses that controlled for covariates and included early and late exposure in the same model, we found that students in the highest quartile for early exposure had 73% greater risk of established smoking than those in the lowest quartile for early exposure (27.8% vs 8.6%; relative risk for Q4 vs Q1 = 1.73, 95% confidence interval = 1.14 to 2.62). However, late exposure to depictions of smoking in movies was not statistically significantly associated with established smoking (22.1% vs 14.0%; relative risk for Q4 vs Q1 = 1.13, 95% confidence interval = 0.89 to 1.44). Whereas 31.6% of established smoking was attributable to early exposure, only an additional 5.3% was attributable to late exposure. Early exposure to smoking depicted in movies is associated with established smoking among adolescents. Educational and policy-related interventions should focus on minimizing early exposure to smoking depicted in movies.

Development of retrospective quantitative and qualitative job-exposure matrices for exposures at a beryllium processing facility.

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Couch, James R; Petersen, Martin; Rice, Carol; Schubauer-Berigan, Mary K

2011-05-01

To construct a job-exposure matrix (JEM) for an Ohio beryllium processing facility between 1953 and 2006 and to evaluate temporal changes in airborne beryllium exposures. Quantitative area- and breathing-zone-based exposure measurements of airborne beryllium were made between 1953 and 2006 and used by plant personnel to estimate daily weighted average (DWA) exposure concentrations for sampled departments and operations. These DWA measurements were used to create a JEM with 18 exposure metrics, which was linked to the plant cohort consisting of 18,568 unique job, department and year combinations. The exposure metrics ranged from quantitative metrics (annual arithmetic/geometric average DWA exposures, maximum DWA and peak exposures) to descriptive qualitative metrics (chemical beryllium species and physical form) to qualitative assignment of exposure to other risk factors (yes/no). Twelve collapsed job titles with long-term consistent industrial hygiene samples were evaluated using regression analysis for time trends in DWA estimates. Annual arithmetic mean DWA estimates (overall plant-wide exposures including administration, non-production, and production estimates) for the data by decade ranged from a high of 1.39 μg/m(3) in the 1950s to a low of 0.33 μg/m(3) in the 2000s. Of the 12 jobs evaluated for temporal trend, the average arithmetic DWA mean was 2.46 μg/m(3) and the average geometric mean DWA was 1.53 μg/m(3). After the DWA calculations were log-transformed, 11 of the 12 had a statistically significant (p < 0.05) decrease in reported exposure over time. The constructed JEM successfully differentiated beryllium exposures across jobs and over time. This is the only quantitative JEM containing exposure estimates (average and peak) for the entire plant history.

Systemic lupus erythematosus and vitamin D deficiency are associated with shorter telomere length among African Americans: a case-control study.

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Brett M Hoffecker

Full Text Available Systemic lupus erythematosus (SLE is a chronic systemic autoimmune disease that disproportionately affects African American females. The causes of SLE are unknown but postulated to be a combination of genetic predisposition and environmental triggers. Vitamin D deficiency is one of the possible environmental triggers. In this study we evaluated relationships between vitamin D status, cellular aging (telomere length and anti-telomere antibodies among African American Gullah women with SLE. The study population included African American female SLE patients and unaffected controls from the Sea Island region of South Carolina. Serum 25-hydroxyvitamin D levels were measured using a nonchromatographic radioimmunoassay. Telomere length was measured in genomic DNA of peripheral blood mononuclear cells (PBMCs by monochrome multiplex quantitative PCR. Anti-telomere antibody levels were measured by enzyme-linked immunosorbent assay (ELISA. Patients with SLE had significantly shorter telomeres and higher anti-telomere antibody titers compared to age- and gender-matched unaffected controls. There was a positive correlation between anti-telomere antibody levels and disease activity among patients and a significant correlation of shorter telomeres with lower 25-hydroxyvitamin D levels in both patients and controls. In follow-up examination of a subset of the patients, the patients who remained vitamin D deficient tended to have shorter telomeres than those patients whose 25-hydroxyvitamin D levels were repleted. Increasing 25-hydroxyvitamin D levels in African American patients with SLE may be beneficial in maintaining telomere length and preventing cellular aging. Moreover, anti-telomere antibody levels may be a promising biomarker of SLE status and disease activity.

Wake-up times following sedation with sevoflurane versus propofol after cardiac surgery.

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Hellström, Jan; Öwall, Anders; Sackey, Peter V

2012-10-01

Intravenous sedation in the intensive care unit (ICU) may contribute to altered consciousness and prolonged mechanical ventilation. We tested the hypothesis that replacing intravenous propofol with inhaled sevoflurane for sedation after cardiac surgery would lead to shorter wake-up times, quicker patient cooperation, and less delusional memories. Following coronary artery bypass surgery with cardiopulmonary bypass, 100 patients were randomized to sedation with sevoflurane via the anesthetic conserving device or propofol. Study drugs were administered for a minimum of 2 hours until criteria for extubation were met. Primary endpoints were time from drug stop to extubation and to adequate verbal response. Secondary endpoints were adverse recovery events, memories reported in the ICU Memory Tool test, and ICU/hospital stay. Median time from drug stop to extubation (interquartile range/total range) was shorter after sevoflurane compared to propofol sedation; 10 (10/100) minutes versus 25 (21/240) minutes (p sedation after cardiac surgery leads to shorter wake-up times and quicker cooperation compared to propofol. No differences were seen in ICU-stay, adverse memories or recovery events in our short-term sedation.

Estimation of exposure to atmospheric pollutants during pregnancy integrating space-time activity and indoor air levels: does it make a difference?

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Marion, OUIDIR; Lise, GIORGIS-ALLEMAND; Sarah, LYON-CAEN; Xavier, MORELLI; Claire, CRACOWSKI; Sabrina, PONTET; Isabelle, PIN; Johanna, LEPEULE; Valérie, SIROUX; Rémy, SLAMA

2016-01-01

Studies of air pollution effects during pregnancy generally only consider exposure in the outdoor air at the home address. We aimed to compare exposure models differing in their ability to account for the spatial resolution of pollutants, space-time activity and indoor air pollution levels. We recruited 40 pregnant women in the Grenoble urban area, France, who carried a Global Positioning System (GPS) during up to 3 weeks; in a subgroup, indoor measurements of fine particles (PM2.5) were conducted at home (n=9) and personal exposure to nitrogen dioxide (NO2) was assessed using passive air samplers (n=10). Outdoor concentrations of NO2, and PM2.5 were estimated from a dispersion model with a fine spatial resolution. Women spent on average 16 h per day at home. Considering only outdoor levels, for estimates at the home address, the correlation between the estimate using the nearest background air monitoring station and the estimate from the dispersion model was high (r=0.93) for PM2.5 and moderate (r=0.67) for NO2. The model incorporating clean GPS data was less correlated with the estimate relying on raw GPS data (r=0.77) than the model ignoring space-time activity (r=0.93). PM2.5 outdoor levels were not to moderately correlated with estimates from the model incorporating indoor measurements and space-time activity (r=−0.10 to 0.47), while NO2 personal levels were not correlated with outdoor levels (r=−0.42 to 0.03). In this urban area, accounting for space-time activity little influenced exposure estimates; in a subgroup of subjects (n=9), incorporating indoor pollution levels seemed to strongly modify them. PMID:26300245

Smoking Topography among Korean Smokers: Intensive Smoking Behavior with Larger Puff Volume and Shorter Interpuff Interval.

Science.gov (United States)

Kim, Sungroul; Yu, Sol

2018-05-18

The difference of smoker's topography has been found to be a function many factors, including sex, personality, nicotine yield, cigarette type (i.e., flavored versus non-flavored) and ethnicity. We evaluated the puffing behaviors of Korean smokers and its association with smoking-related biomarker levels. A sample of 300 participants was randomly recruited from metropolitan areas in South Korea. Topography measures during a 24-hour period were obtained using a CReSS pocket device. Korean male smokers smoked two puffs less per cigarette compared to female smokers (15.0 (13.0⁻19.0) vs. 17.5 (15.0⁻21.0) as the median (Interquartile range)), but had a significantly larger puff volume (62.7 (52.7⁻75.5) mL vs. 53.5 (42.0⁻64.2) mL); p = 0.012). The interpuff interval was similar between men and women (8.9 (6.5⁻11.2) s vs. 8.3 (6.2⁻11.0) s; p = 0.122) but much shorter than other study results. A dose-response association ( p = 0.0011) was observed between daily total puff volumes and urinary cotinine concentrations, after controlling for sex, age, household income level and nicotine addiction level. An understanding of the difference of topography measures, particularly the larger puff volume and shorter interpuff interval of Korean smokers, may help to overcome a potential underestimation of internal doses of hazardous byproducts of smoking.

Effects of concurrent caffeine and mobile phone exposure on local target probability processing in the human brain.

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Trunk, Attila; Stefanics, Gábor; Zentai, Norbert; Bacskay, Ivett; Felinger, Attila; Thuróczy, György; Hernádi, István

2015-09-23

Millions of people use mobile phones (MP) while drinking coffee or other caffeine containing beverages. Little is known about the potential combined effects of MP irradiation and caffeine on cognitive functions. Here we investigated whether caffeine intake and concurrent exposure to Universal Mobile Telecommunications System (UMTS) MP-like irradiation may interactively influence neuro-cognitive function in an active visual oddball paradigm. In a full factorial experimental design, 25 participants performed a simple visual target detection task while reaction time (RT) and electroencephalogram (EEG) was recorded. Target trials were divided into Low and High probability sets based on target-to-target distance. We analyzed single trial RT and alpha-band power (amplitude) in the pre-target interval. We found that RT was shorter in High vs. Low local probability trials, and caffeine further shortened RT in High probability trials relative to the baseline condition suggesting that caffeine improves the efficiency of implicit short-term memory. Caffeine also decreased pre-target alpha amplitude resulting in higher arousal level. Furthermore, pre-target gamma power positively correlated with RT, which may have facilitated target detection. However, in the present pharmacologically validated study UMTS exposure either alone or in combination with caffeine did not alter RT or pre-stimulus oscillatory brain activity.

Evaluation of environmental radiation exposure

International Nuclear Information System (INIS)

Imai, Kazuhiko

1974-01-01

The environmental radiation exposure due to radioactive rare gases is most important both at the time of reactor accidents and also in the long-term normal operation of reactor plants. The exposure dose is usually calculated by means of computers. The procedure of the calculation on environmental exposure dose is divided in several consecutive steps. The calculational formulae frequently used and those proposed recently are given with the explanation on released radionuclides, release to the atmosphere, concentration in the atmosphere, β-ray exposure, γ-ray exposure, and calculation of long-term exposure dose. (Mori, K.)

Chaotic time series prediction for prenatal exposure to polychlorinated biphenyls in umbilical cord blood using the least squares SEATR model

Science.gov (United States)

Xu, Xijin; Tang, Qian; Xia, Haiyue; Zhang, Yuling; Li, Weiqiu; Huo, Xia

2016-04-01

Chaotic time series prediction based on nonlinear systems showed a superior performance in prediction field. We studied prenatal exposure to polychlorinated biphenyls (PCBs) by chaotic time series prediction using the least squares self-exciting threshold autoregressive (SEATR) model in umbilical cord blood in an electronic waste (e-waste) contaminated area. The specific prediction steps basing on the proposal methods for prenatal PCB exposure were put forward, and the proposed scheme’s validity was further verified by numerical simulation experiments. Experiment results show: 1) seven kinds of PCB congeners negatively correlate with five different indices for birth status: newborn weight, height, gestational age, Apgar score and anogenital distance; 2) prenatal PCB exposed group at greater risks compared to the reference group; 3) PCBs increasingly accumulated with time in newborns; and 4) the possibility of newborns suffering from related diseases in the future was greater. The desirable numerical simulation experiments results demonstrated the feasibility of applying mathematical model in the environmental toxicology field.

Modeling and simulation of blast-induced, early-time intracranial wave physics leading to traumatic brain injury.

Energy Technology Data Exchange (ETDEWEB)

Ford, Corey C. (University of New Mexico, Albuquerque, NM); Taylor, Paul Allen

2008-02-01

The objective of this modeling and simulation study was to establish the role of stress wave interactions in the genesis of traumatic brain injury (TBI) from exposure to explosive blast. A high resolution (1 mm{sup 3} voxels), 5 material model of the human head was created by segmentation of color cryosections from the Visible Human Female dataset. Tissue material properties were assigned from literature values. The model was inserted into the shock physics wave code, CTH, and subjected to a simulated blast wave of 1.3 MPa (13 bars) peak pressure from anterior, posterior and lateral directions. Three dimensional plots of maximum pressure, volumetric tension, and deviatoric (shear) stress demonstrated significant differences related to the incident blast geometry. In particular, the calculations revealed focal brain regions of elevated pressure and deviatoric (shear) stress within the first 2 milliseconds of blast exposure. Calculated maximum levels of 15 KPa deviatoric, 3.3 MPa pressure, and 0.8 MPa volumetric tension were observed before the onset of significant head accelerations. Over a 2 msec time course, the head model moved only 1 mm in response to the blast loading. Doubling the blast strength changed the resulting intracranial stress magnitudes but not their distribution. We conclude that stress localization, due to early time wave interactions, may contribute to the development of multifocal axonal injury underlying TBI. We propose that a contribution to traumatic brain injury from blast exposure, and most likely blunt impact, can occur on a time scale shorter than previous model predictions and before the onset of linear or rotational accelerations traditionally associated with the development of TBI.

Health impact assessment of air pollution using a dynamic exposure profile: Implications for exposure and health impact estimates

International Nuclear Information System (INIS)

Dhondt, Stijn; Beckx, Carolien; Degraeuwe, Bart; Lefebvre, Wouter; Kochan, Bruno; Bellemans, Tom; Int Panis, Luc; Macharis, Cathy; Putman, Koen

2012-01-01

In both ambient air pollution epidemiology and health impact assessment an accurate assessment of the population exposure is crucial. Although considerable advances have been made in assessing human exposure outdoors, the assessments often do not consider the impact of individual travel behavior on such exposures. Population-based exposures to NO 2 and O 3 using only home addresses were compared with models that integrate all time-activity patterns—including time in commute—for Flanders and Brussels. The exposure estimates were used to estimate the air pollution impact on years of life lost due to respiratory mortality. Health impact of NO 2 using an exposure that integrates time-activity information was on average 1.2% higher than when assuming that people are always at their home address. For ozone the overall estimated health impact was 0.8% lower. Local differences could be much larger, with estimates that differ up to 12% from the exposure using residential addresses only. Depending on age and gender, deviations from the population average were seen. Our results showed modest differences on a regional level. At the local level, however, time-activity patterns indicated larger differences in exposure and health impact estimates, mainly for people living in more rural areas. These results suggest that for local analyses the dynamic approach can contribute to an improved assessment of the health impact of various types of pollution and to the understanding of exposure differences between population groups. - Highlights: ► Exposure to ambient air pollution was assessed integrating population mobility. ► This dynamic exposure was integrated into a health impact assessment. ► Differences between the dynamic and residential exposure were quantified. ► Modest differences in health impact were found at a regional level. ► At municipal level larger differences were found, influenced by gender and age.

At least 10% shorter C–H bonds in cryogenic protein crystal structures than in current AMBER forcefields

Energy Technology Data Exchange (ETDEWEB)

Pang, Yuan-Ping, E-mail: pang@mayo.edu

2015-03-06

High resolution protein crystal structures resolved with X-ray diffraction data at cryogenic temperature are commonly used as experimental data to refine forcefields and evaluate protein folding simulations. However, it has been unclear hitherto whether the C–H bond lengths in cryogenic protein structures are significantly different from those defined in forcefields to affect protein folding simulations. This article reports the finding that the C–H bonds in high resolution cryogenic protein structures are 10–14% shorter than those defined in current AMBER forcefields, according to 3709 C–H bonds in the cryogenic protein structures with resolutions of 0.62–0.79 Å. Also, 20 all-atom, isothermal–isobaric, 0.5-μs molecular dynamics simulations showed that chignolin folded from a fully-extended backbone formation to the native β-hairpin conformation in the simulations using AMBER forcefield FF12SB at 300 K with an aggregated native state population including standard error of 10 ± 4%. However, the aggregated native state population with standard error reduced to 3 ± 2% in the same simulations except that C–H bonds were shortened by 10–14%. Furthermore, the aggregated native state populations with standard errors increased to 35 ± 3% and 26 ± 3% when using FF12MC, which is based on AMBER forcefield FF99, with and without the shortened C–H bonds, respectively. These results show that the 10–14% bond length differences can significantly affect protein folding simulations and suggest that re-parameterization of C–H bonds according to the cryogenic structures could improve the ability of a forcefield to fold proteins in molecular dynamics simulations. - Highlights: • Cryogenic crystal structures are commonly used in computational studies of proteins. • C–H bonds in the cryogenic structures are shorter than those defined in forcefields. • A survey of 3709 C–H bonds shows that the cryogenic bonds are 10–14% shorter. • The

Reemission spectra and inelastic processes at interaction of attosecond and shorter duration electromagnetic pulses with atoms

International Nuclear Information System (INIS)

Makarov, D.N.; Matveev, V.I.

2017-01-01

Inelastic processes and the reemission of attosecond and shorter electromagnetic pulses by atoms have been considered within the analytical solution of the Schrödinger equation in the sudden perturbation approximation. A method of calculations with the exact inclusion of spatial inhomogeneity of the field of an ultrashort pulse and the momenta of photons in the reemission processes has been developed. The probabilities of inelastic processes and spectra of reemission of ultrashort electromagnetic pulses by one- and many-electron atoms have been calculated. The results have been presented in the form of analytical formulas.

First trimester phthalate exposure and anogenital distance in newborns

Science.gov (United States)

Swan, S.H.; Sathyanarayana, S.; Barrett, E.S.; Janssen, S.; Liu, F.; Nguyen, R.H.N.; Redmon, J.B.; Liu, Fan; Scher, Erica; Stasenko, Marina; Ayash, Erin; Schirmer, Melissa; Farrell, Jason; Thiet, Mari-Paule; Baskin, Laurence; Gray Chelsea Georgesen, Heather L.; Rody, Brooke J.; Terrell, Carrie A.; Kaur, Kapilmeet; Brantley, Erin; Fiore, Heather; Kochman, Lynda; Parlett, Lauren; Marino, Jessica; Hulbert, William; Mevorach, Robert; Pressman, Eva; Ivicek, Kristy; Salveson, Bobbie; Alcedo, Garry

2015-01-01

STUDY QUESTION Is first trimester phthalate exposure associated with anogenital distance (AGD), a biomarker of prenatal androgen exposure, in newborns? SUMMARY ANSWER Concentrations of diethylhexyl phthalate (DEHP) metabolites in first trimester maternal urine samples are inversely associated with AGD in male, but not female, newborns. WHAT IS KNOWN ALREADY AGD is a sexually dimorphic measure reflecting prenatal androgen exposure. Prenatal phthalate exposure has been associated with shorter male AGD in multiple animal studies. Prior human studies, which have been limited by small sample size and imprecise timing of exposure and/or outcome, have reported conflicting results. STUDY DESIGN, SIZE, DURATION The Infant Development and the Environment Study (TIDES) is a prospective cohort study of pregnant women recruited in prenatal clinics in San Francisco, CA, Minneapolis, MN, Rochester, NY and Seattle, WA in 2010–2012. Participants delivered 787 infants; 753 with complete data are included in this analysis. PARTICIPANTS/MATERIALS, SETTING, METHODS Any woman over 18 years old who was able to read and write English (or Spanish in CA), who was <13 weeks pregnant, whose pregnancy was not medically threatened and who planned to deliver in a study hospital was eligible to participate. Analyses include all infants whose mothers provided a first trimester urine sample and who were examined at or shortly after birth. Specific gravity (SpG) adjusted concentrations of phthalate metabolites in first trimester urine samples were examined in relation to genital measurements. In boys (N = 366), we obtained two measures of anogenital distance (AGD) (anoscrotal distance, or AGDAS and anopenile distance, AGDAP) as well as penile width (PW). In girls (N = 373), we measured anofourchette distance (AGDAF) and anoclitoral distance (AGDAC). We used multivariable regression models that adjusted for the infant's age at exam, gestational age, weight-for-length Z-score, time of day of urine

Prospective and retrospective time perception are related to mental time travel: evidence from Alzheimer's disease.

Science.gov (United States)

El Haj, Mohamad; Moroni, Christine; Samson, Séverine; Fasotti, Luciano; Allain, Philippe

2013-10-01

Unlike prospective time perception paradigms, in which participants are aware that they have to estimate forthcoming time, little is known about retrospective time perception in normal aging and Alzheimer's disease (AD). Our paper addresses this shortcoming by comparing prospective and retrospective time estimation in younger adults, older adults, and AD patients. In four prospective tasks (lasting 30s, 60s, 90s, or 120s) participants were asked to read a series of numbers and to provide a verbal estimation of the reading time. In four other retrospective tasks, they were not informed about time judgment until they were asked to provide a verbal estimation of four elapsed time intervals (lasting 30s, 60s, 90s, or 120s). AD participants gave shorter verbal time estimations than older adults and younger participants did, suggesting that time is perceived to pass quickly in these patients. For all participants, the duration of the retrospective tasks was underestimated as compared to the prospective tasks and both estimations were shorter than the real time interval. Prospective time estimation was further correlated with mental time travel, as measured with the Remember/Know paradigm. Mental time travel was even higher correlated with retrospective time estimation. Our findings shed light on the relationship between time perception and the ability to mentally project oneself into time, two skills contributing to human memory functioning. Finally, time perception deficits, as observed in AD patients, can be interpreted in terms of dramatic changes occurring in frontal lobes and hippocampus. Copyright © 2013 Elsevier Inc. All rights reserved.

Does Occupational Exposure of Shahid Dastghieb International Airport Workers to Radiofrequency Radiation Affect Their Short Term Memory and Reaction Time?

Directory of Open Access Journals (Sweden)

Jarideh S.

2015-05-01

Full Text Available Background: Airport workers are continuously exposed to different levels of radiofrequency microwave (RF/MW radiation emitted by radar equipments. Radars are extensively used in military and aviation industries. Over the past several years, our lab has focused on the health effects of exposure to different sources of electromagnetic fields such as cellular phones, mobile base stations, mobile phone jammers, laptop computers, radars, dentistry cavitrons and MRI. The main goal of this study was to investigate if occupational exposure of Shahid Dastghieb international airport workers to radiofrequency radiation affects their short term memory and reaction time. Methods: Thirty two airport workers involved in duties at control and approach tower (21 males and 11 females, with the age range of 27-67 years old (mean age of 37.38, participated voluntary in this study. On the other hand, 29 workers (13 males, and 16 females whose offices were in the city with no exposure history to radar systems were also participated in this study as the control group. The employees’ reaction time and short term memory were analyzed using a standard visual reaction time (VRT test software and the modified Wechsler memory scale test, respectively. Results: The mean± SD values for the reaction times of the airport employees (N=32 and the control group (N=29 were 0.45±0.12 sec and 0.46±0.17 sec, respectively. Moreover, in the four subset tests; i.e. paired words, forward digit span, backward digit span and word recognition, the following points were obtained for the airport employees and the control group, respectively: (i pair words test: 28.00±13.13 and 32.07±11.65, (ii forward digit span: 8.38±1.40 and 9.03±1.32, (iii backward digit span: 5.54±1.87 and 6.31±1.46, and (iv word recognition: 5.73±2.36 and 6.50±1.93. These differences were not statistically significant. Conclusion: The occupational exposure of the employees to the RF radiation in Shahid

Timing of prenatal maternal exposure to severe life events and adverse pregnancy outcomes: A population study of 2.6 million pregnancies

Science.gov (United States)

Class, Quetzal A.; Lichtenstein, Paul; Långström, Niklas; D'Onofrio, Brian M.

2011-01-01

Objective To identify the impact of timing of prenatal stress exposure on offspring risk for shortened gestational age (GA), preterm birth (PTB), low birth weight (LBW), and small for gestational age (SGA) using a population-based sample. Methods Swedish longitudinal population registries were linked to study all individuals born in Sweden 1973–2004. Prenatal maternal stress exposure was defined as death of the father of the child or first degree relative of the mother. Using linear and logistic regression, timing of stress exposure was examined across pregnancy, by month, and by novel periods created based on month of stress exposure findings. Results A total of 2,618,777 live-born, singleton infants without congenital anomalies were included; 32,286 exposed to prenatal maternal stress. Examining associations between stress exposure and outcome by the month revealed that risk increases mid-gestation, particularly following months 5 and 6. Combining months 1–4, 5 and 6, and 7–9 as potential periods of differing vulnerability, it was found that stress during period 2 (months 5 and 6) was associated with the greatest risk for shortened GA (−0.52 days, SE=0.15, p=0.0006), PTB (OR=1.24, 99% CI=1.08–1.42), LBW (OR=1.38, 99% CI=1.19–1.61), and SGA (OR=1.25, 99% CI=1.05–1.49). Conclusions Risk for shortened GA, PTB, LBW, and SGA are greater following stress exposure during the 5th and/or 6th month of pregnancy. It may be beneficial to refine future analyses to these months. Possible mechanisms include alterations in the hypothalamic-pituitary-adrenal axis and associated stress-responsive molecular regulators. PMID:21321257

Use of a novel shorter minimum caliber needle for creating endoscopic tattoos for preoperative localization: a comparative ex vivo study.

Science.gov (United States)

Imai, Kenichiro; Hotta, Kinichi; Ito, Sayo; Yamaguchi, Yuichiro; Kawakami, Takeshi; Wada, Takuya; Igarashi, Kimihiro; Kishida, Yoshihiro; Kinugasa, Yusuke; Kawata, Noboru; Tanaka, Masaki; Kakushima, Naomi; Takizawa, Kohei; Ishiwatari, Hirotoshi; Matsubayashi, Hiroyuki; Ono, Hiroyuki

2017-06-01

In colorectal cancer surgery, inadvertent deep injections during endoscopic tattooing can cause India ink leakage into the peritoneum, leading to complications or to poor visualization of the surgical plane. This ex vivo animal study compared the use of novel shorter, minimum caliber needles versus conventional injection needles for endoscopic tattooing. Four endoscopists used the novel needles and conventional needles to make ten endoscopic tattoos (five tattoos/needle type/endoscopist) in harvested porcine rectum using a saline test-injection method. India ink leakage and the success of the tattoo (i. e. visible, tattoos but for none of the novel needle tattoos ( P  = 0.02). Tattoos created using the novel needles were more successful than those made with the conventional needles: 18/20 (90 %) vs. 11/20 (55 %); P  = 0.01. The use of novel shorter minimum caliber needles may be safe and effective for endoscopic tattooing for preoperative localization prior to colorectal cancer surgery.

Dose-rate effects of ethylene oxide exposure on developmental toxicity.

Science.gov (United States)

Weller, E; Long, N; Smith, A; Williams, P; Ravi, S; Gill, J; Henessey, R; Skornik, W; Brain, J; Kimmel, C; Kimmel, G; Holmes, L; Ryan, L

1999-08-01

In risk assessment, evaluating a health effect at a duration of exposure that is untested involves assuming that equivalent multiples of concentration (C) and duration (T) of exposure have the same effect. The limitations of this approach (attributed to F. Haber, Zur Geschichte des Gaskrieges [On the history of gas warfare], in Funf Vortrage aus den Jahren 1920-1923 [Five lectures from the years 1920-1923], 1924, Springer, Berlin, pp. 76-92), have been noted in several studies. The study presented in this paper was designed to specifically look at dose-rate (C x T) effects, and it forms an ideal case study to implement statistical models and to examine the statistical issues in risk assessment. Pregnant female C57BL/6J mice were exposed, on gestational day 7, to ethylene oxide (EtO) via inhalation for 1.5, 3, or 6 h at exposures that result in C x T multiples of 2100 or 2700 ppm-h. EtO was selected because of its short half-life, documented developmental toxicity, and relevance to exposures that occur in occupational settings. Concurrent experiments were run with animals exposed to air for similar periods. Statistical analysis using models developed to assess dose-rate effects revealed significant effects with respect to fetal death and resorptions, malformations, crown-to-rump length, and fetal weight. Animals exposed to short, high exposures of EtO on day 7 of gestation were found to have more adverse effects than animals exposed to the same C x T multiple but at longer, lower exposures. The implication for risk assessment is that applying Haber's Law could potentially lead to an underestimation of risk at a shorter duration of exposure and an overestimation of risk at a longer duration of exposure. Further research, toxicological and statistical, are required to understand the mechanism of the dose-rate effects, and how to incorporate the mechanistic information into the risk assessment decision process.

MO-E-BRD-02: Accelerated Partial Breast Irradiation in Brachytherapy: Is Shorter Better?

International Nuclear Information System (INIS)

Todor, D.

2015-01-01

Is Non-invasive Image-Guided Breast Brachytherapy Good? – Jess Hiatt, MS Non-invasive Image-Guided Breast Brachytherapy (NIBB) is an emerging therapy for breast boost treatments as well as Accelerated Partial Breast Irradiation (APBI) using HDR surface breast brachytherapy. NIBB allows for smaller treatment volumes while maintaining optimal target coverage. Considering the real-time image-guidance and immobilization provided by the NIBB modality, minimal margins around the target tissue are necessary. Accelerated Partial Breast Irradiation in brachytherapy: is shorter better? - Dorin Todor, PhD VCU A review of balloon and strut devices will be provided together with the origins of APBI: the interstitial multi-catheter implant. A dosimetric and radiobiological perspective will help point out the evolution in breast brachytherapy, both in terms of devices and the protocols/clinical trials under which these devices are used. Improvements in imaging, delivery modalities and convenience are among the factors driving the ultrashort fractionation schedules but our understanding of both local control and toxicities associated with various treatments is lagging. A comparison between various schedules, from a radiobiological perspective, will be given together with a critical analysis of the issues. to review and understand the evolution and development of APBI using brachytherapy methods to understand the basis and limitations of radio-biological ‘equivalence’ between fractionation schedules to review commonly used and proposed fractionation schedules Intra-operative breast brachytherapy: Is one stop shopping best?- Bruce Libby, PhD. University of Virginia A review of intraoperative breast brachytherapy will be presented, including the Targit-A and other trials that have used electronic brachytherapy. More modern approaches, in which the lumpectomy procedure is integrated into an APBI workflow, will also be discussed. Learning Objectives: To review past and current

MO-E-BRD-02: Accelerated Partial Breast Irradiation in Brachytherapy: Is Shorter Better?

Energy Technology Data Exchange (ETDEWEB)

Todor, D. [Virginia Commonwealth University (United States)

2015-06-15

Is Non-invasive Image-Guided Breast Brachytherapy Good? – Jess Hiatt, MS Non-invasive Image-Guided Breast Brachytherapy (NIBB) is an emerging therapy for breast boost treatments as well as Accelerated Partial Breast Irradiation (APBI) using HDR surface breast brachytherapy. NIBB allows for smaller treatment volumes while maintaining optimal target coverage. Considering the real-time image-guidance and immobilization provided by the NIBB modality, minimal margins around the target tissue are necessary. Accelerated Partial Breast Irradiation in brachytherapy: is shorter better? - Dorin Todor, PhD VCU A review of balloon and strut devices will be provided together with the origins of APBI: the interstitial multi-catheter implant. A dosimetric and radiobiological perspective will help point out the evolution in breast brachytherapy, both in terms of devices and the protocols/clinical trials under which these devices are used. Improvements in imaging, delivery modalities and convenience are among the factors driving the ultrashort fractionation schedules but our understanding of both local control and toxicities associated with various treatments is lagging. A comparison between various schedules, from a radiobiological perspective, will be given together with a critical analysis of the issues. to review and understand the evolution and development of APBI using brachytherapy methods to understand the basis and limitations of radio-biological ‘equivalence’ between fractionation schedules to review commonly used and proposed fractionation schedules Intra-operative breast brachytherapy: Is one stop shopping best?- Bruce Libby, PhD. University of Virginia A review of intraoperative breast brachytherapy will be presented, including the Targit-A and other trials that have used electronic brachytherapy. More modern approaches, in which the lumpectomy procedure is integrated into an APBI workflow, will also be discussed. Learning Objectives: To review past and current

Noise exposure levels for musicians during rehearsal and performance times.

Science.gov (United States)

McIlvaine, Devon; Stewart, Michael; Anderson, Robert

2012-03-01

The purpose of this study was to determine daily noise doses and 8-hour time weighted averages for rock band musicians, crew members, and spectators during a typical rehearsal and performance using both Occupational Safety and Health Administration (OSHA) and National Institute of Occupational Safety and Health (NIOSH) measurement criteria. Personal noise dosimetry was completed on five members of a rock band during one 2-hr rehearsal and one 4-hr performance. Time-weighted averages (TWA) and daily dose values were calculated using both OSHA and NIOSH criteria and compared to industry guidelines for enrollment in hearing conservation programs and the use of hearing protection devices. TWA values ranged from 84.3 to 90.4 dBA (OSHA) and from 90.0 to 96.4 dBA (NIOSH) during the rehearsal. The same values ranged from 91.0 to 99.7 dBA (OSHA) and 94.0 to 102.8 dBA (NIOSH) for the performance. During the rehearsal, daily noise doses ranged from 45.54% to 106.7% (OSHA) and from 317.74% to 1396.07% (NIOSH). During the performance, doses ranged from 114.66% to 382.49% (OSHA) and from 793.31% to 5970.15% (NIOSH). The musicians in this study were exposed to dangerously high levels of noise and should be enrolled in a hearing conservation programs. Hearing protection devices should be worn, especially during performances. The OSHA measurement criteria yielded values significantly more conservative than those produced by NIOSH criteria. Audiologists should counsel musician-patients about the hazards of excessive noise (music) exposure and how to protect their hearing.

Hepatitis C virus epitope exposure and neutralization by antibodies is affected by time and temperature

DEFF Research Database (Denmark)

Sabo, Michelle C; Luca, Vincent C; Ray, Stuart C

2012-01-01

A recent study with flaviviruses suggested that structural dynamics of the virion impact antibody neutralization via exposure of ostensibly cryptic epitopes. To determine whether this holds true for the distantly related hepatitis C virus (HCV), whose neutralizing epitopes may be obscured...... by a glycan shield, apolipoprotein interactions, and the hypervariable region on the E2 envelope protein, we assessed how time and temperature of pre-incubation altered monoclonal antibody (MAb) neutralization of HCV. Notably, several MAbs showed increased inhibitory activity when pre-binding was performed...

Exploratory study on a statistical method to analyse time resolved data obtained during nanomaterial exposure measurements

International Nuclear Information System (INIS)

Clerc, F; Njiki-Menga, G-H; Witschger, O

2013-01-01

Most of the measurement strategies that are suggested at the international level to assess workplace exposure to nanomaterials rely on devices measuring, in real time, airborne particles concentrations (according different metrics). Since none of the instruments to measure aerosols can distinguish a particle of interest to the background aerosol, the statistical analysis of time resolved data requires special attention. So far, very few approaches have been used for statistical analysis in the literature. This ranges from simple qualitative analysis of graphs to the implementation of more complex statistical models. To date, there is still no consensus on a particular approach and the current period is always looking for an appropriate and robust method. In this context, this exploratory study investigates a statistical method to analyse time resolved data based on a Bayesian probabilistic approach. To investigate and illustrate the use of the this statistical method, particle number concentration data from a workplace study that investigated the potential for exposure via inhalation from cleanout operations by sandpapering of a reactor producing nanocomposite thin films have been used. In this workplace study, the background issue has been addressed through the near-field and far-field approaches and several size integrated and time resolved devices have been used. The analysis of the results presented here focuses only on data obtained with two handheld condensation particle counters. While one was measuring at the source of the released particles, the other one was measuring in parallel far-field. The Bayesian probabilistic approach allows a probabilistic modelling of data series, and the observed task is modelled in the form of probability distributions. The probability distributions issuing from time resolved data obtained at the source can be compared with the probability distributions issuing from the time resolved data obtained far-field, leading in a

Factors affecting outdoor exposure in winter: population-based study

Science.gov (United States)

Mäkinen, Tiina M.; Raatikka, Veli-Pekka; Rytkönen, Mika; Jokelainen, Jari; Rintamäki, Hannu; Ruuhela, Reija; Näyhä, Simo; Hassi, Juhani

2006-09-01

The extent of outdoor exposure during winter and factors affecting it were examined in a cross-sectional population study in Finland. Men and women aged 25-74 years from the National FINRISK 2002 sub-study ( n=6,591) were queried about their average weekly occupational, leisure-time and total cold exposure during the past winter. The effects of gender, age, area of residence, occupation, ambient temperature, self-rated health, physical activity and education on cold exposure were analysed. The self-reported median total cold exposure time was 7 h/week (8 h men, 6 h women),employed in agriculture, forestry and industry/mining/construction or related occupations, being less educated and being aged 55-64 years. Factors associated with increased leisure-time cold exposure among men were: employment in industry/mining/construction or related occupations, being a pensioner or unemployed, reporting at least average health, being physically active and having college or vocational education. Among women, being a housewife, pensioner or unemployed and engaged in physical activity increased leisure-time cold exposure, and young women were more exposed than older ones. Self-rated health was positively associated with leisure time cold exposure in men and only to a minor extent in women. In conclusion, the subjects reported spending 4% of their total time under cold exposure, most of it (71%) during leisure time. Both occupational and leisure-time cold exposure is greater among men than women.

A characterization of persistence at short times in the WFC3/IR detector

Science.gov (United States)

Gennaro, M.; Bajaj, V.; Long, K.

2018-05-01

Persistence in the WFC3/IR detector appears to decay as a power law as a function of time elapsed since the end of a stimulus. In this report we study departures from the power law at times shorter than a few hundreds seconds after the stimulus. In order to have better short-time cadence, we use the Multiaccum (.ima) files, which trace the accumulated charge in the pixels as function of time, rather than the final pipeline products (.flt files), which instead report the electron rate estimated via a linear fit to the accumulated charge vs. time relation. We note that at short times after the stimulus, the absolute change in persistence is the strongest, thus a linear fit to the accumulated signal (the .flt values) can be a poor representation of the strongly varying persistence signal. The already observed power-law decay of the persistence signal, still holds at shorter times, with typical values of the power law index, gamma in [-0.8,-1] for stimuli that saturate the WFC3 pixels. To a good degree of approximation, a single power law is a good fit to the persistence signal decay from 100 to 5000 seconds. We also detect a tapering-off in the power-law decay at increasingly shorter times. This change in behavior is of the order of Delta Gamma 0.02 - 0.05 when comparing power-law fits performed to the persistence signal from 0 up to 250 seconds and from 0 up to 4000 seconds after the stimulus, indicating that persistence decays slightly more rapidly as time progresses. Our results may suggest that for even shorter times, not probed by our study, the WFC3 persistence signal might deviate from a single power-law model.

Focus on Chronic Exposure for Deriving Drinking Water Guidance Underestimates Potential Risk to Infants

Directory of Open Access Journals (Sweden)

Helen Goeden

2018-03-01

Full Text Available In 2007, the Minnesota Department of Health (MDH developed new risk assessment methods for deriving human health-based water guidance (HBG that incorporated the assessment of multiple exposure durations and life stages. The methodology is based on US Environmental Protection Agency recommendations for protecting children’s health (US EPA 2002. Over the last 10 years, the MDH has derived multiple duration (e.g., short-term, subchronic, and chronic water guidance for over 60 chemicals. This effort involved derivation of multiple duration reference doses (RfDs and selection of corresponding water intake rates (e.g., infant, child, and lifetime. As expected, RfDs typically decreased with increasing exposure duration. However, the corresponding HBG frequently did not decrease with increasing duration. For more than half of the chemicals, the shorter duration HBG was lower than chronic HBG value. Conventional wisdom has been that chronic-based values will be the most conservative and will therefore be protective of less than chronic exposures. However, the MDH’s experience highlights the importance of evaluating short-term exposures. For many chemicals, elevated intake rates early in life, coupled with short-term RfDs, resulted in the lowest HBG. Drinking water criteria based on chronic assessments may not be protective of short-term exposures in highly exposed populations such as formula-fed infants.

Benzene exposures in urban areas

International Nuclear Information System (INIS)

Valerio, F.; Pala, M.; Cipolla, M.; Stella, A.

2001-01-01

Benzene exposures in urban areas were reviewed. Available data confirm that both in USA and Europe, benzene concentrations measured by fixed outdoor monitoring stations underestimate personal exposures of urban residents. Indoor sources, passive smoke and the high exposures during commuting time may explain this difference. Measures in European towns confirm that very frequently mean daily personal exposures to benzene exceed 10 μg/m 3 , current European air quality guideline for this carcinogenic compound [it

Buffering Capacity of Fast-Growing Species and Curing Time of UF Resin Modified With Zinc Borate and Monoammonium Phosphate

OpenAIRE

Izran Kamal; Koh M. Poh; Tan Y. Eng; Xue J. Ren; Zaidon Ashaari; Faizah Abood; Guenter Beyer; Khairul Masseat

2010-01-01

Problem statement: Occupying a suitable hot pressing time for particleboard fabrication seems very tricky for manufacturers of the wood-based panel. Longer or shorter pressing times can affect physical and mechanical properties of the produced particleboards and that is why extra care should be given on this matter. Longer pressing time can cause resin in a particleboard to over-cure whereas shorter pressing time can cause insufficient curing of the resin. Determination of hot pressing time i...

The Evaluation of Conventional X-ray Exposure Parameters Including Tube Voltage and Exposure Time in Private and Governmental Hospitals of Lorestan Province, Iran