A VIRTUAL REALITY EXPOSURE THERAPY FOR PTSD PATIENTS CONTROLLED BY A FUZZY LOGIC SYSTEM

Directory of Open Access Journals (Sweden)

Rosa Maria Esteves Moreira da Costa

2014-06-01

Full Text Available This paper describes the main characteristics of two integrated systems that explore Virtual Reality technology and Fuzzy Logic to support and to control the assessment of people with Post-Traumatic Stress Disorder during the Virtual Reality Exposure Therapy. The integration of different technologies, the development methodology and the test procedures are described throughout the paper.

A virtual reality exposure therapy for PTSD patients controlled by a fuzzy logic system

OpenAIRE

Oliveira, F. M.; Lanzillotti, R. S.; Da Costa, R. M. E. M.; Gonçalves, R.; Ventura, P.; Carvalho, L. A. V. de

2014-01-01

This paper describes the main characteristics of two integrated systems that explore Virtual Reality technology and Fuzzy Logic to support and to control the assessment of people with Post-Traumatic Stress Disorder during the Virtual Reality Exposure Therapy. The integration of different technologies, the development methodology and the test procedures are described throughout the paper. Peer Reviewed

PET radiation exposure control for nurses

International Nuclear Information System (INIS)

Kawabata, Yumiko; Kikuta, Daisuke; Anzai, Taku

2005-01-01

Recently, the number of clinical PET centers is increasing all over Japan. For this reason, the monitoring and control of radiation exposure of employees, especially nurses, in PET-dedicated clinics and institutions are becoming very important issues for their health. We measured the radiation exposure doses of the nurses working at Nishidai Diagnostic Imaging Center, and analyzed the exposure data obtained from them. The exposure doses of the nurses were found to be 4.8 to 7.1 mSv between April 2003 and March 2004. We found that the nurses were mostly exposed to radiation when they had to have contact with patients received an FDG injection or they had trouble with the FDG automatic injection system. To keep radiation exposure of nurses to a minimum we reconfirmed that a proper application of the three principles of protection against radiation exposure was vital. (author)

Changes in the α4β2* nicotinic acetylcholine system during chronic controlled alcohol exposure in nonhuman primates.

Science.gov (United States)

Hillmer, Ansel T; Tudorascu, Dana L; Wooten, Dustin W; Lao, Patrick J; Barnhart, Todd E; Ahlers, Elizabeth O; Resch, Leslie M; Larson, Julie A; Converse, Alexander K; Moore, Colleen F; Schneider, Mary L; Christian, Bradley T

2014-05-01

The precise nature of modifications to the nicotinic acetylcholine receptor (nAChR) system in response to chronic ethanol exposure is poorly understood. The present work used PET imaging to assay α4β2* nAChR binding levels of eight rhesus monkeys before and during controlled chronic ethanol intake. [(18)F]Nifene PET scans were conducted prior to alcohol exposure, and then again after at least 8 months controlled ethanol exposure, including 6 months at 1.5 g/kg/day following a dose escalation period. Receptor binding levels were quantified with binding potentials (BPND) using the cerebellum as a reference region. Alcohol self-administration was assessed as average daily alcohol intake during a 2 month free drinking period immediately following controlled alcohol. Significant decreases in α4β2* nAChR binding were observed in both frontal and insular cortex in response to chronic ethanol exposure. During chronic alcohol exposure, BPND in the lateral geniculate region correlated positively with the amount of alcohol consumed during free drinking. The observed decreases in nAChR availability following chronic alcohol consumption suggest alterations to this receptor system in response to repeated alcohol administration, making this an important target for further study in alcohol abuse and alcohol and nicotine codependence. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Simultaneous Control of Phenanthrene and Drought by Dual Exposure System

DEFF Research Database (Denmark)

Schmidt, Stine N.; Holmstrup, Martin; Damgaard, Christian

2014-01-01

Organisms in the environment are exposed to multiple stressors. However, for terrestrial invertebrates, it remains difficult to study the effects of combined stressors under well-defined exposure conditions. Thus, the current study develops a new dual exposure system for the simultaneous...... set revealed statistically significant synergy between phenanthrene and drought (p account when...

Evaluation of automatic exposure control system chamber for the dose optimization when examining pelvic in digital radiography.

Science.gov (United States)

Kim, Sung-Chul; Lee, Hae-Kag; Lee, Yang-Sub; Cho, Jae-Hwan

2015-01-01

We found a way to optimize the image quality and reduce the exposure dose of patients through the proper activity combination of the automatic exposure control system chamber for the dose optimization when examining the pelvic anteroposterior side using the phantom of the human body standard model. We set 7 combinations of the chamber of automatic exposure control system. The effective dose was yielded by measuring five times for each according to the activity combination of the chamber for the dose measurement. Five radiologists with more than five years of experience evaluated the image through picture archiving and communication system using double blind test while classifying the 6 anatomical sites into 3-point level (improper, proper, perfect). When only one central chamber was activated, the effective dose was found to be the highest level, 0.287 mSv; and lowest when only the top left chamber was used, 0.165 mSv. After the subjective evaluation by five panel members on the pelvic image was completed, there was no statistically meaningful difference between the 7 chamber combinations, and all had good image quality. When testing the pelvic anteroposterior side with digital radiography, we were able to reduce the exposure dose of patients using the combination of the top right side of or the top two of the chamber.

Pediatric Exposures to Topical Benzocaine Preparations Reported to a Statewide Poison Control System.

Science.gov (United States)

Vohra, Rais; Huntington, Serena; Koike, Jennifer; Le, Kevin; Geller, Richard J

2017-08-01

Topical benzocaine is a local anesthetic commonly used to relieve pain caused by teething, periodontal irritation, burns, wounds, and insect bites. Oral preparations may contain benzocaine concentrations ranging from 7.5% to 20%. Pediatric exposure to such large concentrations may result in methemoglobinemia and secondarily cause anemia, cyanosis, and hypoxia. This is a retrospective study of exposures reported to a statewide poison control system. The electronic health records were queried for pediatric exposures to topical benzocaine treated at a healthcare facility from 2004 to 2014. Cases of benzocaine exposure were reviewed for demographic and clinical information, and descriptive statistical analysis was performed. The query resulted in 157 cases; 58 were excluded due to co-ingestants, or miscoding of non-benzocaine exposures. Children four years of age and younger represented the majority of cases (93%) with a median age of 1 year. There were 88 cases of accidental/ exploratory exposure, while 6 cases resulted from therapeutic application or error, 4 cases from adverse reactions, and 1 case from an unknown cause. Asymptomatic children accounted for 75.5% of cases, but major clinical effects were observed in 5 patients. Those with serious effects were exposed to a range of benzocaine concentrations (7.5-20%), with 4 cases reporting methemoglobin levels between 20.2%-55%. Methylene blue was administered in 4 of the cases exhibiting major effects. The majority of exposures were accidental ingestions by young children. Most exposures resulted in minor to no effects. However, some patients required treatment with methylene blue and admission to a critical care unit. Therapeutic application by parents or caregivers may lead to adverse effects from these commonly available products.

A rule-based expert system for control rod pattern of boiling water reactors by hovering around haling exposure shape

International Nuclear Information System (INIS)

Kao, P.-W.; Lin, L.-S.; Yang, J.-T.

2004-01-01

Feasible strategies for automatic BWR control rod pattern generation have been implemented in a rule-based expert system. These strategies are majorly based on a concept for which exposure distributions are hovering around the Haling exposure distribution through a cycle while radial and axial power distributions are dominantly controlled by some abstracted factors indicating the desired distributions. The system can either automatically generate expert-level control rod patterns or search for criteria-satisfied patterns originated from user's input. It has successfully been demonstrated by generating control rod patterns for the the 1775 MWth Chinshan plant in Unit I Cycle 13 alternate loading pattern and Unit 2 Cycle 8 but with longer cycle length. All rod patterns for two cycles result in all-rod-out at EOC and no violation against the four criteria. The demonstrations show that the system is considerably good in choosing initial trial rod patterns and adjusting rod patterns to satisfy the design criteria. (author)

Pediatric Exposures to Topical Benzocaine Preparations Reported to a Statewide Poison Control System

Directory of Open Access Journals (Sweden)

Rais Vohra

2017-07-01

Full Text Available Introduction: Topical benzocaine is a local anesthetic commonly used to relieve pain caused by teething, periodontal irritation, burns, wounds, and insect bites. Oral preparations may contain benzocaine concentrations ranging from 7.5% to 20%. Pediatric exposure to such large concentrations may result in methemoglobinemia and secondarily cause anemia, cyanosis, and hypoxia. Methods: This is a retrospective study of exposures reported to a statewide poison control system. The electronic health records were queried for pediatric exposures to topical benzocaine treated at a healthcare facility from 2004 to 2014. Cases of benzocaine exposure were reviewed for demographic and clinical information, and descriptive statistical analysis was performed. Results: The query resulted in 157 cases; 58 were excluded due to co-ingestants, or miscoding of non-benzocaine exposures. Children four years of age and younger represented the majority of cases (93% with a median age of 1 year. There were 88 cases of accidental/ exploratory exposure, while 6 cases resulted from therapeutic application or error, 4 cases from adverse reactions, and 1 case from an unknown cause. Asymptomatic children accounted for 75.5% of cases, but major clinical effects were observed in 5 patients. Those with serious effects were exposed to a range of benzocaine concentrations (7.5–20%, with 4 cases reporting methemoglobin levels between 20.2%–55%. Methylene blue was administered in 4 of the cases exhibiting major effects. Conclusion: The majority of exposures were accidental ingestions by young children. Most exposures resulted in minor to no effects. However, some patients required treatment with methylene blue and admission to a critical care unit. Therapeutic application by parents or caregivers may lead to adverse effects from these commonly available products.

Evaluation of automatic exposure control systems in computed tomography

International Nuclear Information System (INIS)

Reina, Thamiris Rosado

2014-01-01

The development of the computed tomography (CT) technology has brought wider possibilities on diagnostic medicine. It is a non-invasive method to see the human body in details. As the CT application increases, it raises the concern about patient dose, because the higher dose levels imparted compared to other diagnostic imaging modalities. The radiology community (radiologists, medical physicists and manufacturer) are working together to find the lowest dose level possible, without compromising the diagnostic image quality. The greatest and relatively new advance to lower the patient dose is the automatic exposure control (AEC) systems in CT. These systems are designed to ponder the dose distribution along the patient scanning and between patients taking into account their sizes and irradiated tissue densities. Based on the CT scanning geometry, the AEC-systems are very complex and their functioning is yet not fully understood. This work aims to evaluate the clinical performance of AEC-systems and their susceptibilities to assist on possible patient dose optimizations. The approach to evaluate the AEC-systems of three of the leading CT manufacturers in Brazil, General Electric, Philips and Toshiba, was the extraction of tube current modulation data from the DICOM standard image sequences, measurement and analysis of the image noise of those image sequences and measurement of the dose distribution along the scan length on the surface and inside of two different phantoms configurations. The tube current modulation of each CT scanner associated to the resulted image quality provides the performance of the AECsystem. The dose distribution measurements provide the dose profile due to the tube current modulation. Dose measurements with the AEC-system ON and OFF were made to quantify the impact of these systems regarding patient dose. The results attained give rise to optimizations on the AEC-systems applications and, by consequence, decreases the patient dose without

Evaluation of automatic exposure control systems in computed tomography

Energy Technology Data Exchange (ETDEWEB)

Reina, Thamiris Rosado

2014-07-01

The development of the computed tomography (CT) technology has brought wider possibilities on diagnostic medicine. It is a non-invasive method to see the human body in details. As the CT application increases, it raises the concern about patient dose, because the higher dose levels imparted compared to other diagnostic imaging modalities. The radiology community (radiologists, medical physicists and manufacturer) are working together to find the lowest dose level possible, without compromising the diagnostic image quality. The greatest and relatively new advance to lower the patient dose is the automatic exposure control (AEC) systems in CT. These systems are designed to ponder the dose distribution along the patient scanning and between patients taking into account their sizes and irradiated tissue densities. Based on the CT scanning geometry, the AEC-systems are very complex and their functioning is yet not fully understood. This work aims to evaluate the clinical performance of AEC-systems and their susceptibilities to assist on possible patient dose optimizations. The approach to evaluate the AEC-systems of three of the leading CT manufacturers in Brazil, General Electric, Philips and Toshiba, was the extraction of tube current modulation data from the DICOM standard image sequences, measurement and analysis of the image noise of those image sequences and measurement of the dose distribution along the scan length on the surface and inside of two different phantoms configurations. The tube current modulation of each CT scanner associated to the resulted image quality provides the performance of the AECsystem. The dose distribution measurements provide the dose profile due to the tube current modulation. Dose measurements with the AEC-system ON and OFF were made to quantify the impact of these systems regarding patient dose. The results attained give rise to optimizations on the AEC-systems applications and, by consequence, decreases the patient dose without

Compatibility of automatic exposure control with new screen phosphors in diagnostic roentgenography

International Nuclear Information System (INIS)

Mulvaney, J.A.

1982-01-01

Automatic exposure control systems are used in diagnostic roentgenography to obtain proper film density for a variety of patient examinations and roentgenographic techniques. Most automatic exposure control systems have been designed for use with par speed, calcium tungstate intensifying screens. The use of screens with faster speeds and new phosphor materials has put extreme demands on present systems. The performance of a representative automatic exposure control system is investigated to determine its ability to maintain constant film density over a wide range of x-ray tube voltages and acrylic phantom thicknesses with four different intensifying screen phosphors. The effects of x-ray energy dependence, generator switching time and stored change are investigated. The system is able to maintain film density to within plus or minus 0.2 optical density units for techniques representing adult patients. A single nonadjustable tube voltage compensation circuit is adequate for the four different screen phosphors for x-ray tube voltages above sixty peak kilovolts. For techniques representing pediatric patients at high x-ray tube voltages, excess film density occurs due to stored charge in the transformer and high-voltage cables. An anticipation circuit in the automatic exposure control circuit can be modified to correct for stored charge effects. In a seperate experiment the energy dependence of three different ionization chamber detectors used in automatic exposure control systems is compared directly with the energy dependence of three different screen phosphors. The data on detector sensitivity and screen speed are combined to predict the best tube voltage compensation for each combination of screen and detector

Electronic device for automatic control of exposure in radiography

International Nuclear Information System (INIS)

Pendharkar, A.S.; Jayakumar, T.K.

1977-01-01

An electronic instrument for calculating and controlling exposure in radiography practice using radioisotopes is described. When using this equipment, only factor to be known is the dose required by the film for a given density and the thickness of material inspected. It eliminates all the problems arising out of various parameters such as source decay etc in the conventional procedure for calculating exposure time. Principle of operation, the electronic circuitry adopted and the functional aspects of the system are described in detail. Exposure doses for different industrial films have been related to the instrumental readouts. The system reproducibility and reliability have been evaluated. The advantages and limitations of the present system and the future development to overcome the problems are indicated. (author)

Wood smoke in a controlled exposure experiment with human volunteers

DEFF Research Database (Denmark)

Riddervold, Ingunn Skogstad; Bønløkke, Jakob Hjort; Mølhave, Lars

2011-01-01

Exposure to wood smoke in the general population is increasing and concurrently, also our awareness. This article describes a wood-smoke generating system for studying human exposure to wood smoke and symptoms related to this exposure. Twenty nonsmoking atopic human participants with normal lung...... function and normal bronchial reactivity were randomly exposed for 3h at three different exposure conditions; clean filtered air (control exposure) and wood smoke with a characteristic particulate matter (PM) concentration of 200 µg/m3 (low) and 400 µg/m3 (high) under controlled environmental conditions.......0007), “irritative body perceptions” (p = 0.0127), “psychological/neurological effects” (p = 0.0075) and “weak inflammatory responses” (p = 0.0003). Furthermore, significant effects (p = 0.0192) on self-reported general mucosa irritation were found. In conclusion, exposure to wood smoke affected symptom rating...

Radiation exposure and central nervous system cancers: A case-control study among workers at two nuclear facilities

International Nuclear Information System (INIS)

Carpenter, A.V.; Flanders, W.D.; Frome, E.L.; Crawford-Brown, D.J.; Fry, S.A.

1987-03-01

A nested case-control study was conducted among workers employed between 1943 and 1977 at two nuclear facilities to investigate the possible association of primary malignant neoplasms of the central nervous system (CNS) with occupational exposure to ionizing radiation from external and internal sources. Eighty-nine white male and female workers, who according to the information on death certificates dies of primary CNS cancers, were identified as cases. Four matched controls were selected for each case. External radiation exposure data were available from film badge readings for individual workers, whereas radiation dose to lung from internally deposited radionuclides, mainly uranium, was estimated from area and personnel monitoring data and was used in analyses in lieu of the dose to the brain. Matched sets were included in the analyses only if information was available for the case and at least one of the corresponding controls. Thus, the analyses of external radiation included 27 cases and 90 matched controls, and 47 cases and 120 matched controls were analyzed for the effects of radiation from internally deposited uranium. No association was observed between deaths fron CNS cancers and occupational exposure to ionizing radiation from external or internal sources. However, due to the small number of monitored subjects and low doses, a weak association could not be ruled out. 43 refs., 1 fig., 15 tabs

The evaluation of the performance of the automatic exposure control system of some selected mammography facilities in the Greater Accra Region, Ghana

International Nuclear Information System (INIS)

Amesimenu, R.

2013-07-01

Mammography aids in the early detection of breast cancer. X-rays has an associated risk of inducing cancer though very useful and as such mammography procedures should be optimized through the appropriate processes such as the selection of exposure factors for an optimum image and minimal dose to patients. The automatic exposure control (AEC) aids in the selection of exposure factors thus controlling the amount of radiation to the breast and automatically compensates for differences in the breast thickness and density. The performance of the automatic exposure control system of mammography equipment and the status of quality management systems including quality assurance and quality controls of four (4) mammography facilities within the Greater Accra Region were assessed. In assessing the performance of the automatic exposure control system, the short term reproducibility test, thickness and voltage compensation test were carried out using breast equivalent phantom of various thicknesses. Half value layer test, film reject analysis and patient dose assessment were also performed. Analysis of the responses of the questionnaire administered to radiographers and supervisors of the selected facilities revealed that three (3) of the facilities have some aspect of quality management system programme in place but not effectively implemented. Measured optical densities from the various tests performed to evaluate the performance of the automatic exposure control systems revealed that the AEC compensates for the different phantom thickness and tube voltage (KV) by producing comparable optical densities for the various phantom thickness and tube voltages. Some of the measured optical densities were within the recommended optical density range of 1.5 OD - 1.9 OD. The highest optical density value was 0.13 OD above the highest limit of 1.9 OD. The film reject analysis showed that patient motion accounted for the large part (28%) of film rejects. Other factors such as too light

Development of personnel exposure management system with personal computer

International Nuclear Information System (INIS)

Yamato, Ichiro; Yamamoto, Toshiki

1992-01-01

In nuclear power plants, large scale personnel exposure management systems have been developed and established by utilities. Though being common in the base, the implementations are specific by plants. Contractors must control their workers' exposures by their own methods and systems. To comply with the utilities' parental systems, contractors' systems tend to differ by plants, thus make it difficult for contractors to design a standard system that is common to all relevant plants. Circumstances being as such, however, we have developed a system which is applicable to various customer utilities with minimal variations, using personal computers with database management and data communication softwares, with relatively low cost. We hope that this system will develop to the standard model for all Japanese contractors' personnel exposure management systems. (author)

[Advances in research on automatic exposure control of mammography system].

Science.gov (United States)

Wang, Guoyi; Ye, Chengfu; Wu, Haiming; Wang, Tainfu; Zhang, Hong

2014-12-01

Mammography imaging is one of the most demanding imaging modalities from the point of view of the bal- ance between image quality (the visibility of small size and/or low contrast structures) and dose (screening of many asymptomatic people). Therefore, since the introduction of the first dedicated mammographic units, many efforts have been directed to seek the best possible image quality while minimizing patient dose. The performance of auto- matic exposure control (AEC) is the manifestation of this demand. The theory of AEC includes exposure detection and optimization and also involves some accomplished methodology. This review presents the development and present situa- tion of spectrum optimization, detector evolution, and the way how to accomplish and evaluate AEC methods.

Risk Assessment and Control through Countermeasure System Iplementation for Long-term Crew Exposure to Microgravity

Science.gov (United States)

Gernand, Jeremy M.

2004-01-01

Experience with the International Space Station (ISS) program demonstrates the degree to which engineering design and operational solutions must protect crewmembers from health risks due to long-term exposure to the microgravity environment. Risks to safety and health due to degradation in the microgravity environment include crew inability to complete emergency or nominal activities, increased risk of injury, and inability to complete safe return to the ground due to reduced strength or embrittled bones. These risks without controls slowly increase in probability for the length of the mission and become more significant for increasing mission durations. Countermeasures to microgravity include hardware systems that place a crewmember s body under elevated stress to produce an effect similar to daily exposure to gravity. The ISS countermeasure system is predominately composed of customized exercise machines. Historical treatment of microgravity countermeasure systems as medical research experiments unintentionally reduced the foreseen importance and therefore the capability of the systems to function in a long-term operational role. Long-term hazardous effects and steadily increasing operational risks due to non-functional countermeasure equipment require a more rigorous design approach and incorporation of redundancy into seemingly non- mission-critical hardware systems. Variations in the rate of health degradation and responsiveness to countermeasures among the crew population drastically increase the challenge for design requirements development and verification of the appropriate risk control strategy. The long-term nature of the hazards and severe limits on logistical re-supply mass, volume and frequency complicates assessment of hardware availability and verification of an adequate maintenance and sparing plan. Design achievement of medically defined performance requirements by microgravity countermeasure systems and incorporation of adequate failure tolerance

Perinatal taurine exposure affects adult arterial pressure control

Science.gov (United States)

Roysommuti, Sanya; Wyss, J. Michael

2012-01-01

Taurine is an abundant free amino acid found in mammalian cells that contributes to many physiologic functions from that of a simple cell osmolyte to a programmer of adult health and disease. Taurine’s contribution extends from conception throughout life, but its most critical exposure period is during perinatal life. In adults, taurine supplementation prevents or alleviates cardiovascular disease and related complications. In contrast, low taurine consumption coincides with increased risk of cardiovascular disease, obesity and type II diabetes. This review focuses on the effects that altered perinatal taurine exposure has on long-term mechanisms that control adult arterial blood pressure and could thereby contribute to arterial hypertension through its ability to program these cardiovascular regulatory mechanisms very early in life. The modifications of these mechanisms can last a lifetime and transfer to the next generation, suggesting that epigenetic mechanisms underlie the changes. The ability of perinatal taurine exposure to influence arterial pressure control mechanisms and hypertension in adult life appears to involve the regulation of growth and development, the central and autonomic nervous system, the renin-angiotensin system, glucose-insulin interaction and changes to heart, blood vessels and kidney function. PMID:23070226

Development of risk-based nanomaterial groups for occupational exposure control

International Nuclear Information System (INIS)

Kuempel, E. D.; Castranova, V.; Geraci, C. L.; Schulte, P. A.

2012-01-01

Given the almost limitless variety of nanomaterials, it will be virtually impossible to assess the possible occupational health hazard of each nanomaterial individually. The development of science-based hazard and risk categories for nanomaterials is needed for decision-making about exposure control practices in the workplace. A possible strategy would be to select representative (benchmark) materials from various mode of action (MOA) classes, evaluate the hazard and develop risk estimates, and then apply a systematic comparison of new nanomaterials with the benchmark materials in the same MOA class. Poorly soluble particles are used here as an example to illustrate quantitative risk assessment methods for possible benchmark particles and occupational exposure control groups, given mode of action and relative toxicity. Linking such benchmark particles to specific exposure control bands would facilitate the translation of health hazard and quantitative risk information to the development of effective exposure control practices in the workplace. A key challenge is obtaining sufficient dose–response data, based on standard testing, to systematically evaluate the nanomaterials’ physical–chemical factors influencing their biological activity. Categorization processes involve both science-based analyses and default assumptions in the absence of substance-specific information. Utilizing data and information from related materials may facilitate initial determinations of exposure control systems for nanomaterials.

Development of risk-based nanomaterial groups for occupational exposure control

Science.gov (United States)

Kuempel, E. D.; Castranova, V.; Geraci, C. L.; Schulte, P. A.

2012-09-01

Given the almost limitless variety of nanomaterials, it will be virtually impossible to assess the possible occupational health hazard of each nanomaterial individually. The development of science-based hazard and risk categories for nanomaterials is needed for decision-making about exposure control practices in the workplace. A possible strategy would be to select representative (benchmark) materials from various mode of action (MOA) classes, evaluate the hazard and develop risk estimates, and then apply a systematic comparison of new nanomaterials with the benchmark materials in the same MOA class. Poorly soluble particles are used here as an example to illustrate quantitative risk assessment methods for possible benchmark particles and occupational exposure control groups, given mode of action and relative toxicity. Linking such benchmark particles to specific exposure control bands would facilitate the translation of health hazard and quantitative risk information to the development of effective exposure control practices in the workplace. A key challenge is obtaining sufficient dose-response data, based on standard testing, to systematically evaluate the nanomaterials' physical-chemical factors influencing their biological activity. Categorization processes involve both science-based analyses and default assumptions in the absence of substance-specific information. Utilizing data and information from related materials may facilitate initial determinations of exposure control systems for nanomaterials.

Set up and operation for medical radiation exposure quality control system of health promotion center

Energy Technology Data Exchange (ETDEWEB)

Kim, Jung Su; Kim, Jung Min [Korea University,Seoul (Korea, Republic of); Jung, Hae Kyoung [Dept. of Diagnostic Radiology, CHA Bundang Medical Center, CHA University, Sungnam (Korea, Republic of)

2016-03-15

In this study, standard model of medical radiation dosage quality control system will be suggested and the useful of this system in clinical field will be reviewed. Radiation dosage information of modalities are gathered from digital imaging and communications in medicine(DICOM) standard data(such as DICOM dose SR and DICOM header) and stored in database. One CT scan, two digital radiography modalities and two mammography modalities in one health promotion center in Seoul are used to derive clinical data for one month. After 1 months research with 703 CT scans, the study shows CT 357.9 mGy·cm in abdomen and pelvic CT, 572.4 mGy·cm in brain without CT, 55.9 mGy·cm in calcium score/heart CT, screening CT at 54 mGy·cm in chest screening CT(low dose screening CT scan), 284.99 mGy·cm in C-spine CT and 341.85 mGy·cm in L-spine CT as health promotion center reference level of each exam. And with 1955 digital radiography cases, it shows 274.0 mGy·cm{sup 2} and for mammography 6.09 mGy is shown based on 536 cases. The use of medical radiation shall comply with the principles of justification and optimization. This quality management of medical radiation exposure must be performed in order to follow the principle. And the procedure to reduce the radiation exposure of patients and staff can be achieved through this. The results of this study can be applied as a useful tool to perform the quality control of medical radiation exposure.

Set up and operation for medical radiation exposure quality control system of health promotion center

International Nuclear Information System (INIS)

Kim, Jung Su; Kim, Jung Min; Jung, Hae Kyoung

2016-01-01

In this study, standard model of medical radiation dosage quality control system will be suggested and the useful of this system in clinical field will be reviewed. Radiation dosage information of modalities are gathered from digital imaging and communications in medicine(DICOM) standard data(such as DICOM dose SR and DICOM header) and stored in database. One CT scan, two digital radiography modalities and two mammography modalities in one health promotion center in Seoul are used to derive clinical data for one month. After 1 months research with 703 CT scans, the study shows CT 357.9 mGy·cm in abdomen and pelvic CT, 572.4 mGy·cm in brain without CT, 55.9 mGy·cm in calcium score/heart CT, screening CT at 54 mGy·cm in chest screening CT(low dose screening CT scan), 284.99 mGy·cm in C-spine CT and 341.85 mGy·cm in L-spine CT as health promotion center reference level of each exam. And with 1955 digital radiography cases, it shows 274.0 mGy·cm"2 and for mammography 6.09 mGy is shown based on 536 cases. The use of medical radiation shall comply with the principles of justification and optimization. This quality management of medical radiation exposure must be performed in order to follow the principle. And the procedure to reduce the radiation exposure of patients and staff can be achieved through this. The results of this study can be applied as a useful tool to perform the quality control of medical radiation exposure

Hexavalent chromium exposures and exposure-control technologies in American enterprise: results of a NIOSH field research study.

Science.gov (United States)

Blade, L M; Yencken, M Story; Wallace, M E; Catalano, J D; Khan, A; Topmiller, J L; Shulman, S A; Martinez, A; Crouch, K G; Bennett, J S

2007-08-01

The National Institute for Occupational Safety and Health (NIOSH) conducted 21 field surveys in selected industries to characterize workers' exposures to hexavalent chromium-containing airborne particulate and to evaluate existing technologies for controlling these exposures. Hexavalent chromium Cr(VI) is a respiratory irritant and chronic inhalation may cause lung cancer. Primary evaluation methods included collection of full work shift, personal breathing-zone (PBZ) air samples for Cr(VI), measurement of ventilation system parameters, and documentation of processes and work practices. This study emphasized evaluation of engineering exposure control measures, so PBZ exposures were measured on the outside of personal protective equipment, for example, respirators. Field surveys were conducted in two chromium electroplating facilities, including one where full-shift PBZ exposures to Cr(VI) ranged from 3.0 to 16 times the 1 micro g/m(3)NIOSH recommended exposure limit (REL) despite several engineering controls on the plating tanks. At a painting and coating facility that used Cr(VI)-containing products, full-shift exposures of painters and helpers (2.4 to 55 micro g/m(3)) exceeded the REL, but LEV effectiveness was limited. Other operations evaluated included welding in construction; metal cutting operations on chromium-containing materials in ship breaking; chromate-paint removal with abrasive blasting; atomized alloy-spray coating; foundry operations; printing; and the manufacture of refractory brick, colored glass, prefabricated concrete products, and treated wood products. NIOSH researchers concluded that, in many of the evaluated processes, Cr(VI) exposures at or below the current NIOSH REL are achievable. However, for some processes, it is unclear whether controlling exposures to this range is consistently achievable without respirator use. Some operations involving the application of coatings and finishes may be among those most difficult to control to this

A utility perspective on radiation worker access control systems

International Nuclear Information System (INIS)

Watson, B.A.; Goff, T.E.

1984-01-01

Based on an evaluation of the current commercial Radiation Worker Access Control Software Systems, Baltimore Gas and Electric Company has elected to design and develop a site specific access control and accountability system for the Calvert Cliffs Nuclear Power Plant. The vendor provided systems allow for radiation worker access control based on training and external exposure records and authorizations. These systems do not afford internal exposure control until after bioassay measurements or maximum permissible concentration-hours are tabulated. The vendor provided systems allow for data trending for ALARA purposes, but each software package must be modified to meet site specific requirements. Unlike the commercial systems, the Calvert Cliffs Radiological Controls and Accountability System (RCAS) will provide radiation worker exposure control, both internal and external. The RCAS is designed to fulfill the requirements by integrating the existing Radiation Safety, Dosemetry, and Training data bases with a comprehensive radiological surveillance program. Prior to each worker's entry into the Radiological Control Area; his training and qualifications, radiation exposure history and authorization, will be compared with administrative controls, such as radiation work permits, and respiratory protection requirements and the radiological conditions in the work area. The RCAS, a computer based applied health physics access control system is described as it is presently configured for development. The mechanisms for enhancing worker internal and external exposure controls are discussed. Proposed data application to both the Calvert Cliffs ALARA and outage planning programs is included

Controlling exposure to radon, France, December 2006

International Nuclear Information System (INIS)

Godet, J.L.; Perrin, M.L.; Dechaux, E.; Pineau, C.

2007-01-01

Controlling exposure to radon, France, December 2006 Exposure to radon, along with medical exposure, is the leading source of the French population exposure to ionizing radiation. Radon is a confirmed cause of lung cancer in man (classified in group I by the international Agency for research on Cancer (I.A.R.C.)). According to available estimates, the numbers of lung cancers attributable to radon exposure in France are far fewer than those caused by tobacco. However, according to a recent European study, around 9% of lung cancers in Europe may be caused by radon. Thus, due to the number of people exposed, radon has become a public health issue which calls for action, considering that exposure can be significantly reduced by implementing measures which are often simple. Since 2002, the Nuclear Safety Authority (Asn) has proceeded in implementing a new regulatory framework for the risk management related to the presence of radon in public places. The new system is now fully operational. In addition, based on the initiatives adopted by the government in June 2004 in the context of the National Health and Environment Plan (P.N.S.E.), the Asn drew up a plan in 2005, in collaboration with the Ministry for Urban Planning and Construction, to coordinate the actions of various national bodies involved in this field. This three-pronged strategy is as follows: - Creation of a new risk management policy related to the presence of radon in existing homes and in new buildings; - Supporting and controlling the implementation of regulations for managing radon related risks in public places; - Improvement and dissemination of knowledge on radon exposure and its related risks. (author)

Nano-metal oxides: Exposure and engineering control assessment.

Science.gov (United States)

Garcia, Alberto; Eastlake, Adrienne; Topmiller, Jennifer L; Sparks, Christopher; Martinez, Kenneth; Geraci, Charles L

2017-09-01

In January 2007, the National Institute for Occupational Safety and Health (NIOSH) conducted a field study to evaluate process specific emissions during the production of ENMs. This study was performed using the nanoparticle emission assessment technique (NEAT). During this study, it was determined that ENMs were released during production and cleaning of the process reactor. Airborne concentrations of silver, nickel, and iron were found both in the employee's personal breathing zone and area samples during reactor cleaning. At the completion of this initial survey, it was suggested that a flanged attachment be added to the local exhaust ventilation system.  NIOSH re-evaluated the facility in December 2011 to assess worker exposures following an increase in production rates. This study included a fully comprehensive emissions, exposure, and engineering control evaluation of the entire process. This study made use of the nanoparticle exposure assessment technique (NEAT 2.0). Data obtained from filter-based samples and direct reading instruments indicate that reactor cleanout increased the overall particle concentration in the immediate area. However, it does not appear that these concentrations affect areas outside of the production floor. As the distance between the reactor and the sample location increased, the observed particle number concentration decreased, creating a concentration gradient with respect to the reactor. The results of this study confirm that the flanged attachment on the local exhaust ventilation system served to decrease exposure potential.  Given the available toxicological data of the metals evaluated, caution is warranted. One should always keep in mind that occupational exposure levels were not developed specifically for nanoscale particles. With data suggesting that certain nanoparticles may be more toxic than the larger counterparts of the same material; employers should attempt to control emissions of these particles at the source

Radiation exposure control by estimation of multiplication factors for online remote radiation monitoring systems at Vitrification Plant

International Nuclear Information System (INIS)

Deokar, Umesh V.; Kukarni, V.V.; Khot, A.R.; Mathew, P.; Kamlesh; Purohit, R.G.; Sarkar, P.K.

2011-01-01

Vitrification Plant is commissioned for vitrification of high-level liquid waste generated in Nuclear Fuel Cycle operations by using Joule Heated Ceramic Melter first time in India. Exposure control is a major concern in operating plant. Therefore, in addition to installed monitors, we have developed online remote radiation monitoring system to minimize number of entries in amber areas and to reduce the exposure to the surveyor and operator. This also helped in volume reduction of secondary waste. The reliability and accuracy of the online monitoring system is confirmed with actual measurements and by theoretical shielding calculations. The multiplication factors were estimated for remote online monitoring of Melter off Gas (MOG) filter, Hood filter, three exhaust filter banks, and overpack monitoring. This paper summarizes how the online remote monitoring system had helped in saving of 128.52 Person-mSv collective dose (14.28% of budgeted dose) and also there was 2.6 m 3 reduction in generation of Cat-I waste. (author)

Management and control aimed at reducing potential exposure of cobalt irradiation units

International Nuclear Information System (INIS)

Yan Yukui

2003-01-01

This paper is intended to address the problems of the management and control of potential exposure of cobalt irradiation units and analyze both the current situation and the resultant accident reasons associated with irradiation units, with the necessary control measures provided to reduce potential exposure. The concepts of defense in depth and excellent engineering practice are introduced in design to provide the units with sufficient redundancy. In the course of scientific management, the qualified applicants or registers devoted, strictly and effectively, their oversight, monitoring and regulation to the irradiation units. The effective management and control are achieved through safety analysis and assessment, reasonable regulatory system and source decommissioning system. (authors)

Personal exposure control using TLD

International Nuclear Information System (INIS)

Ishiguro, Hideharu; Takeda, Shinso

1979-01-01

In the Tokai Works of the Power Reactor and Nuclear Fuel Development Corporation (PNC), for personal exposure control, the switching from film badges to TLD badges (and also finger-ring type local dosimeters) was made in fiscal 1974. The facilities involved are a fuel reprocessing plant, a PuO 2 -UO 2 mixed fuel production facility, and a centrifugal uranium enrichment development facility. The types of radiation concerned are various, such as γ(x), β and n. The situation of personal exposure control with TLD and the dose evaluation methods for respective radiations are explained. The number of personnel subject to exposure control, including transient people, is about 2500 - 3000 per three months. The TLD badges used are a special PNC type with TLDs to measure separately γ(x), β and n. With casings made of ABS resin, the external dimensions are 76 mm x 46 mm. (J.P.N.)

Radiation exposure control by estimation of multiplication factors for online remote radiation monitoring systems at vitrification plant

International Nuclear Information System (INIS)

Deokar, U.V.; Kulkarni, V.V.; Khot, A.R.; Mathew, P.; Kamlesh; Purohit, R.G.; Sarkar, P.K.

2012-01-01

Vitrification Plant is commissioned for vitrification of high level liquid waste (HLW) generated in nuclear fuel cycle operations by using Joule Heated Ceramic Melter first time in India. Exposure control is a major concern in operating plant. Therefore in addition to installed monitors, we have developed online remote radiation monitoring system to minimize number of entries in amber areas and to reduce the exposure to the surveyor and operator. This also helped in volume reduction of secondary waste. The reliability and accuracy of the online monitoring system is confirmed with actual measurements and by theoretical shielding calculations. The multiplication factors were estimated for remote on line monitoring of Melter Off Gas (MOG) filter, Hood filter, three exhaust filter banks, and over-pack monitoring. This paper summarizes - how the online remote monitoring system helped in saving of 128.52 person-mSv collective dose (14.28% of budgeted dose). The system also helped in the reduction of 2.6 m 3 of Cat-I waste. Our online remote monitoring system has helped the plant management to plan in advance for replacement of these filters, which resulted in considerable saving in collective dose and secondary waste

Results of verifications of the control automatic exposure in equipment of RX with CR systems; Resultados de las verificaciones del control automatico de exposicion en equipos de RX con sistemas CR

Energy Technology Data Exchange (ETDEWEB)

Ruiz Manzano, P.; Rivas Ballarin, M. A.; Ortega Pardina, P.; Villa Gazulla, D.; Calvo Carrillo, S.; Canellas Anoz, M.; Millan Cebrian, E.

2013-07-01

After the entry into force in 2012, the new Spanish Radiology quality control protocol lists and discusses the results obtained after verification of the automatic control of exposure in computed radiography systems. (Author)

Effects of Lifetime Occupational Pesticide Exposure on Postural Control Among Farmworkers and Non-Farmworkers.

Science.gov (United States)

Sunwook, Kim; Nussbaum, Maury A; Quandt, Sara A; Laurienti, Paul J; Arcury, Thomas A

2016-02-01

The aim of the study was to assess potential chronic effects of pesticide exposure on postural control, by examining postural balance of farmworkers and non-farmworkers diverse self-reported lifetime exposures. Balance was assessed during quiet upright stance under four experimental conditions (2 visual × 2 cognitive difficulty). Significant differences in baseline balance performance (eyes open without cognitive task) between occupational groups were apparent in postural sway complexity. When adding a cognitive task to the eyes open condition, the influence of lifetime exposure on complexity ratios appeared different between occupational groups. Removing visual information revealed a negative association of lifetime exposure with complexity ratios. Farmworkers and non-farmworkers may use different postural control strategies even when controlling for the level of lifetime pesticide exposure. Long-term exposure can affect somatosensory/vestibular sensory systems and the central processing of sensory information for postural control.

Risk of Central Nervous System Tumors in Children Related to Parental Occupational Pesticide Exposures in three European Case-Control Studies

NARCIS (Netherlands)

Febvey, Olivia; Schüz, Joachim; Bailey, Helen D; Clavel, Jacqueline; Lacour, Brigitte; Orsi, Laurent; Lightfoot, Tracy; Roman, Eve; Vermeulen, Roel; Kromhout, Hans; Olsson, Ann

2016-01-01

OBJECTIVE: The aim of this study was to assess the risk of childhood central nervous system (CNS) tumors associated with parental occupational pesticide exposure. METHODS: We pooled three population-based case-control studies from France, Germany, and the United Kingdom. Cases were children below 15

In Vitro Exposure Systems and Dosimetry Assessment Tools ...

Science.gov (United States)

In 2009, the passing of The Family Smoking Prevention and Tobacco Control Act facilitated the establishment of the FDA Center for Tobacco Products (CTP) and gave it regulatory authority over the marketing, manufacture and distribution of tobacco products, including those termed “modified risk”. On 4-6 April 2016, the Institute for In Vitro Sciences, Inc. (IIVS) convened a workshop conference titled “In Vitro Exposure Systems and Dosimetry Assessment Tools for Inhaled Tobacco Products” to bring together stakeholders representing regulatory agencies, academia, and industry to address the research priorities articulated by the FDA CTP. Specific topics were covered to assess the status of current in vitro smoke and aerosol/vapor exposure systems, as well as the various approaches and challenges to quantifying the complex exposures, in in vitro pulmonary models developed for evaluating adverse pulmonary events resulting from tobacco product exposures. The four core topics covered were, 1) Tobacco Smoke And E-Cigarette Aerosols, 2) Air-Liquid Interface-In Vitro Exposure Systems, 3) Dosimetry Approaches For Particles And Vapors; In Vitro Dosimetry Determinations and 4) Exposure Microenvironment/Physiology Of Cells. The two and a half day workshop included presentations from 20 expert speakers, poster sessions, networking discussions, and breakout sessions which identified key findings and provided recommendations to advance these technologies. Here, we will re

Assessment of arsenic exposures and controls in gallium arsenide production.

Science.gov (United States)

Sheehy, J W; Jones, J H

1993-02-01

The electronics industry is expanding the use of gallium arsenide in the production of optoelectronic devices and integrated circuits. Workers in the electronics industry using gallium arsenide are exposed to hazardous substances such as arsenic, arsine, and various acids. Arsenic requires stringent controls to minimize exposures (the current OSHA PEL for arsenic is 10 micrograms/m3 and the NIOSH REL is 2 micrograms/m3 ceiling). Inorganic arsenic is strongly implicated in respiratory tract and skin cancer. For these reasons, NIOSH researchers conducted a study of control systems for facilities using gallium arsenide. Seven walk-through surveys were performed to identify locations for detailed study which appeared to have effective controls; three facilities were chosen for in-depth evaluation. The controls were evaluated by industrial hygiene sampling. Including personal breathing zone and area air sampling for arsenic and arsine; wipe samples for arsenic also were collected. Work practices and the use of personal protective equipment were documented. This paper reports on the controls and the arsenic exposure results from the evaluation of the following gallium arsenide processes: Liquid Encapsulated Czochralski (LEC) and Horizontal Bridgeman (HB) crystal growing, LEC cleaning operations, ingot grinding/wafer sawing, and epitaxy. Results at one plant showed that in all processes except epitaxy, average arsenic exposures were at or above the OSHA action level of 5 micrograms/m3. While cleaning the LEC crystal pullers, the average potential arsenic exposure of the cleaning operators was 100 times the OSHA PEL. At the other two plants, personal exposures for arsenic were well controlled in LEC, LEC cleaning, grinding/sawing, and epitaxy operations.

Effect of ultraviolet exposure on mitochondrial respiratory system

Energy Technology Data Exchange (ETDEWEB)

Noda, K [Kurume Univ., Fukuoka (Japan). School of Medicine

1975-09-01

To find the photodynamic effect of ultraviolet light on the mitochondrial respiratory chain, mitochondria were obtained from rat livers, and the suspension was exposed to an extensive ultraviolet light. The oxygen consumption was measured polarographically with a Clark oxygen electrode. The effect of ultraviolet exposure on the five states of respiratory control (Chance and Williams), the P/O ratio, and the respiratory control index in mitochondria was discussed. The ultraviolet light with a dose of 9.6 x 10/sup 6/ erg/cm/sup 2/ caused the oxidative phosphorylation in mitochondria to uncouple. The 2nd phosphorylation site of the respiratory chain was susceptible to ultraviolet exposure. The stimulation of latent ATPase activity in mitochondria following exposure was observed by increasing exposure of ultraviolet light. However, DNP-stimulated ATPase was found to be stable in activity. The uncoupling of the respiratory chain by ultraviolet exposure was not detected if the mitochondrial suspension was preincubated with bovine serum albumin before exposure. The changes in light absorption of the mitochondrial suspension were followed at 520 nm after exposure. A close correlation was found between the ultraviolet exposure and swelling in mitochondria. But, the reversing contraction was observed by adding ATP to the swelled mitochondria. The peroxide compound was formed in mitochondria irradiated with ultraviolet light. The amount of compounds formed was dependent on the radiant energy of ultraviolet light. The possible mechanisms involved in the photodynamic effect of ultraviolet light to the mitochondrial respiration system were discussed.

A multiple objective test assembly approach for exposure control problems in Computerized Adaptive Testing

Directory of Open Access Journals (Sweden)

Theo J.H.M. Eggen

2010-01-01

Full Text Available Overexposure and underexposure of items in the bank are serious problems in operational computerized adaptive testing (CAT systems. These exposure problems might result in item compromise, or point at a waste of investments. The exposure control problem can be viewed as a test assembly problem with multiple objectives. Information in the test has to be maximized, item compromise has to be minimized, and pool usage has to be optimized. In this paper, a multiple objectives method is developed to deal with both types of exposure problems. In this method, exposure control parameters based on observed exposure rates are implemented as weights for the information in the item selection procedure. The method does not need time consuming simulation studies, and it can be implemented conditional on ability level. The method is compared with Sympson Hetter method for exposure control, with the Progressive method and with alphastratified testing. The results show that the method is successful in dealing with both kinds of exposure problems.

Water Chemistry Control in Reducing Corrosion and Radiation Exposure at PWR Reactor

International Nuclear Information System (INIS)

Febrianto

2006-01-01

Water chemistry control plays an important role in relation to plant availability, reliability and occupational radiation exposures. Radiation exposures of nuclear plant workers are determined by the radiation rate dose and by the amount maintenance and repair work time Water chemistry has always been, from beginning of operation of power Pressurized Water Reactor, an important factor in determining the integrity of reactor components, fuel cladding integrity and minimize out of core radiation exposures. For primary system, the parameters to control the quality of water chemistry have been subject to change in time. Reactor water coolant pH need to be optimally controlled and be operated in range pH 6.9 to 7.4. At pH lower than 6.9, cause increasing the radiation exposure level and increasing coolant water pH higher than 7.4 will decrease radiation exposure level but increasing risk to fuel cladding and steam generator tube. Since beginning 90 decade, PWR water coolant pH tend to be operated at pH 7.4. This paper will discuss concerning water chemistry development in reducing corrosion and radiation exposure dose in PWR reactor. (author)

Controlling occupational radiation exposure. Alternatives to regulation

International Nuclear Information System (INIS)

Sagan, L.A.; Squitieri, R.; Wildman, S.S.

1980-01-01

The principal strategy adopted for the control of occupational radiation exposure has been the establishment of standards expressed as maximum permissible exposures. The use of such standards is subject to a number of defects, among which is the neglect of the economic impact of imposing such standards. Furthermore, such standards carry the implication of a threshold for radiation effects, a concept now widely challenged. Lastly, the use of standards makes it impossible to evaluate the efficiency of the regulatory agency or to compare its performance with other similar agencies. An alternative to the use of standards, i.e. cost-benefit analysis, is discussed. The advantages of this technique meet many of the objections to the use of standards alone and allow health and safety resources to be allocated in a manner most likely to save the most lives. The greatest disadvantage of cost-benefit analysis has been the difficulty in evaluating the benefit side of the equation. Although the risks of radiation exposure are not known with precision, they are nevertheless well understood. Therefore, the application of cost-benefit analysis to occupational radiation exposure is rational. There are a number of barriers to reform in the use of standards and the adoption of cost-benefit analysis. These attitudinal and institutional constraints are discussed. The nature of private or market systems of control are discussed, i.e. the use of liability and insurance mechanisms. These also have shortcomings that require further development but are seen as potentially more efficient for both employer and employee than is the use of regulatory standards. (author)

Radiation camera exposure control

International Nuclear Information System (INIS)

Martone, R.J.; Yarsawich, M.; Wolczek, W.

1976-01-01

A system and method for governing the exposure of an image generated by a radiation camera to an image sensing camera is disclosed. The exposure is terminated in response to the accumulation of a predetermined quantity of radiation, defining a radiation density, occurring in a predetermined area. An index is produced which represents the value of that quantity of radiation whose accumulation causes the exposure termination. The value of the predetermined radiation quantity represented by the index is sensed so that the radiation camera image intensity can be calibrated to compensate for changes in exposure amounts due to desired variations in radiation density of the exposure, to maintain the detectability of the image by the image sensing camera notwithstanding such variations. Provision is also made for calibrating the image intensity in accordance with the sensitivity of the image sensing camera, and for locating the index for maintaining its detectability and causing the proper centering of the radiation camera image

Performance of automatic exposure control of digital imaging systems in three big hospitals

International Nuclear Information System (INIS)

Avramova-Cholakova, S.; Dyakov, I.

2012-01-01

The digital imaging systems are quite new in Bulgaria and there is still no clear evidence between all the servicing companies how to set the automatic exposure control (AEC) of the systems. The aim of this work is to study the AEC settings of the digital imaging systems in three big hospitals, serviced by different engineering companies. This study included seven systems, one with digital radiography (DR) and the others with computed radiography (CR) detectors. The AEC settings were tested in terms of mean pixel value (MPV), air kerma at phantom exit and detector dose indicator (DDI) dependence from AEC chamber selection, tube voltage and phantom thickness. Relatively small variations in MPV up to 8 % were observed for 4 of the CR systems, usually with small variations in DDI as well (except for one system, for which up to 40 % difference in DDI consistency between chambers was found). Air kerma at phantom exit for these systems had bigger variations up to 29 %. The other CR systems had big variations in MPV up to 57 % with DDI variations up to 30 % while air kerma changes were not small - from 8 to 38 %. The DR system showed smaller variation in air kerma at phantom exit up to 8 % and bigger variations in MPV and DDI up to 20 % and 15 % respectively. There is no systematic approach in the AEC settings used in the 3 hospitals. Further investigation and collaboration with the servicing companies is needed aiming to establish the optimized selection of AEC calibration parameters in each case. (authors)

Effect of automatic exposure control marker with chest radiography in radiation reduction

International Nuclear Information System (INIS)

Jung, Ji Sang; Choi, Byoung Wook; Shim, Ji Na; Ahn, Ho Sik; Jin, Duk Eun; Liml, Jae Sik; Kang, Sung Ho; Kim, Sung Ho; Kim, Young Mo

2014-01-01

This study focused on effects of patient exposure dose reduction with AEC (Auto Exposure Control) marker that is designed for showing location of AEC in X-ray Chest radiography. It included 880 adults who have to use Chest X-ray Digital Radiography system (DRS, LISTEM, Korea). AEC (Ion chambers are posited in top of both sides) are used to every adult and set X-ray system as Field size 17 x 17 inch, 120 kVp, FFD 180 cm. 440 people of control group are posited on detector to include both sides of lung field and the other 440 people of experimental group are set to contact their lung directly to Ion chamber (making marker to shows location). Then, measured every DAP and, estimated patient effective dose by using PCXMC 2.0. The average age of control group (M:F=245:195) is 53.9 and the average BMI is 23.4. BMI ranges from under weight: 35, normal range: 279, over weight: 106 to obese: 20 and average DAP is 223.56 mGycm2, Mean effective dose is 0.045 mSv. The average age of experimental group (M:F=197:243) is 53.7 and the average BMI is 22.7. BMI ranges from under weight: 34, normal range: 315, over weight: 85 to obese: 6 and average DAP is 207.36 mGycm2, Mean effective dose is 0.041 mSv. Experimental group shows less Mean effective dose as 0.004mSv (9.7%) than control group. Also, patient numbers who got over exposure more than 0.056 mSv (limit point to know efficiency of AEC marker) is 65 in control group(14.7%), 19 in experimental group (4.3%) and take statistics with t-Test. The statistical difference between two groups is 0.006. In order to use proper amount of X-ray in auto exposure controlled chest X-ray system, matching location between ion chamber and body part is needed, and using AEC marker (designed for showing location of ion chamber) is a way to reduce unnecessary patient exposure dose

Effect of automatic exposure control marker with chest radiography in radiation reduction

Energy Technology Data Exchange (ETDEWEB)

Jung, Ji Sang; Choi, Byoung Wook; Shim, Ji Na; Ahn, Ho Sik; Jin, Duk Eun; Liml, Jae Sik; Kang, Sung Ho [Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of); Kim, Sung Ho [LISTEM, Woonju (Korea, Republic of); Kim, Young Mo [Dept. of Biomedical Engineering, Konyang University, Nonsan (Korea, Republic of)

2014-09-15

This study focused on effects of patient exposure dose reduction with AEC (Auto Exposure Control) marker that is designed for showing location of AEC in X-ray Chest radiography. It included 880 adults who have to use Chest X-ray Digital Radiography system (DRS, LISTEM, Korea). AEC (Ion chambers are posited in top of both sides) are used to every adult and set X-ray system as Field size 17 x 17 inch, 120 kVp, FFD 180 cm. 440 people of control group are posited on detector to include both sides of lung field and the other 440 people of experimental group are set to contact their lung directly to Ion chamber (making marker to shows location). Then, measured every DAP and, estimated patient effective dose by using PCXMC 2.0. The average age of control group (M:F=245:195) is 53.9 and the average BMI is 23.4. BMI ranges from under weight: 35, normal range: 279, over weight: 106 to obese: 20 and average DAP is 223.56 mGycm2, Mean effective dose is 0.045 mSv. The average age of experimental group (M:F=197:243) is 53.7 and the average BMI is 22.7. BMI ranges from under weight: 34, normal range: 315, over weight: 85 to obese: 6 and average DAP is 207.36 mGycm2, Mean effective dose is 0.041 mSv. Experimental group shows less Mean effective dose as 0.004mSv (9.7%) than control group. Also, patient numbers who got over exposure more than 0.056 mSv (limit point to know efficiency of AEC marker) is 65 in control group(14.7%), 19 in experimental group (4.3%) and take statistics with t-Test. The statistical difference between two groups is 0.006. In order to use proper amount of X-ray in auto exposure controlled chest X-ray system, matching location between ion chamber and body part is needed, and using AEC marker (designed for showing location of ion chamber) is a way to reduce unnecessary patient exposure dose.

Automatic Exposure Control Devices for Digital Mammography

National Research Council Canada - National Science Library

Fajardo, Laurie

2000-01-01

Purpose: The broad, long-term objective of this IDEA proposal is to achieve optimized image quality for DM within acceptable limits of radiation exposure by developing innovative approaches for controlling DM exposures. Scope...

Important exposure controls for protection against antineoplastic agents: Highlights for oncology health care workers.

Science.gov (United States)

Alehashem, Maryam; Baniasadi, Shadi

2018-01-01

A great number of antineoplastic drugs (ANPDs) are used globally in cancer treatment. Due to their adverse health effects, occupational exposure to ANPDs is considered a potential health risk to health care workers. The current study aimed to evaluate safe-handling practices of ANPDs, exposure controls, and adverse health implications for health care providers exposed to ANDPs. Prevention measures, including engineering, administrative, and work practice controls, as well as personal protective equipment (PPE), were recorded daily through a questionnaire for six weeks. Acute adverse health effects experienced by health care workers were also documented. The implemented exposure controls for preparation, administration, cleaning, and waste disposal were not in accordance with the safe handling guidelines. Central nervous system disorders (26.33%) were the most frequent acute adverse effects reported by health care workers. A significant correlation was found between the number of experienced adverse effects and handling characteristics, including the number of preparations (r = 0.38, p health care workers were in danger of exposure to ANPDs and experienced acute adverse health effects. Implementation of appropriate exposure controls is required to prevent occupational exposure to ANPDs.

A new radiation exposure record system

International Nuclear Information System (INIS)

Lyon, M.; Berndt, V.L.; Trevino, G.W.; Oakley, B.M.

1993-04-01

The Hanford Radiological Records Program (HRRP) serves all Hanford contractors as the single repository for radiological exposure for all Hanford employees, subcontractors, and visitors. The program administers and preserves all Hanford radiation exposure records. The program also maintains a Radiation Protection Historical File which is a historical file of Hanford radiation protection and dosimetry procedures and practices. Several years ago DOE declared the existing UNIVAC mainframe computer obsolete and the existing Occupational Radiation Exposure (ORE) system was slated to be redeveloped. The new system named the Radiological Exposure (REX) System is described in this document

Control of external radiation exposure

International Nuclear Information System (INIS)

Abd Nasir Ibrahim; Azali Muhammad; Ab Razak Hamzah; Abd Aziz Mohamed; Mohammad Pauzi Ismail

2004-01-01

The following subjects are discussed - Control of external radiation exposure: working time, working distance, shielding: Total Linear Attenuation Coefficient, Half-Value Layer (HVL), Tenth-Value Layer (TVL); Build-up Factor

30 CFR 57.5005 - Control of exposure to airborne contaminants.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Control of exposure to airborne contaminants... Underground § 57.5005 Control of exposure to airborne contaminants. Control of employee exposure to harmful airborne contaminants shall be, insofar as feasible, by prevention of contamination, removal by exhaust...

30 CFR 56.5005 - Control of exposure to airborne contaminants.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Control of exposure to airborne contaminants... Air Quality and Physical Agents Air Quality § 56.5005 Control of exposure to airborne contaminants. Control of employee exposure to harmful airborne contaminants shall be, insofar as feasible, by prevention...

Four exposure holography system

International Nuclear Information System (INIS)

Mix, L.P.; Kessler, R.W.

1977-03-01

A four exposure holographic interferometry system, designed for studying transient phenomena occurring on nanosecond time scales and particularly those associated with relativistic electron beams, is described. This system permits four holographic exposures of a single transient event to be made with independently adjustable interpulse spacings of from 6 to 28 nsec. The system is portable, allows for a wide range of image magnifications, features colinear scene beams to facilitate alignment and large aperture imaging lenses to minimize refraction phenomena. The various design parameters are discussed and typical holograms presented to indicate the types of data which may be obtained

Trends in Teenagers' Nonopiod Substance Exposures Reported to Poison Control Centers, 2010-2015.

Science.gov (United States)

Wright, Brad; Mestan, Samantha; Ahrens, Monica; Bottei, Edward

2018-05-01

To describe current trends in nonopioid substance exposures and associated outcomes among teenagers nationwide. In this cross-sectional study, we used 2010-2015 data from the American Association of Poison Control Centers' National Poison Data System and Poisson tests to document trends in the rate of calls to poison control centers involving adolescents stratified by sex, exposures by substance category, proportion of intentional exposures, and severity of exposures. The number of calls per 1000 persons increased from 5.7 to 6.8 for teenage girls and decreased from 4.7 to 4.3 for boys. Reported exposures to prescription and over-the-counter medications and illicit street drugs increased between 24% and 73%, and reported opioid exposures decreased by 16%. Among teenage girls, intentional exposures increased from 57% to 68%, with cases increasingly managed in health care facilities and more likely to result in worse health outcomes. The increase in intentional nonopioid substance exposures among teenage girls, with serious and potentially life-threatening consequences, is a matter of serious concern. Similar trends were not observed among teenage boys. Copyright © 2017 Elsevier Inc. All rights reserved.

Development of Automatic Remote Exposure Controller for Gamma Radiography

International Nuclear Information System (INIS)

Joo, Gwang Tae; Shin, Jin Seong; Kim, Dong Eun; Song, Jung Ho; Choo, Seung Hwan; Chang, Hong Keun

2002-01-01

Recently, gamma radiographic equipment have been used about 1,000 sets manually and operated by about 2,500 persons in Korea. In order for a radiography to work effectively with avoiding any hazard of the high level radiation from the source, many field workers have expected developing a wireless automatic remote exposure controller. The KlTCO research team has developed an automatic remote exposure controller that can regulate the speed of 0.4∼1.2m/s by BLDC motor of 24V 200W which has output of 54 kgf·, suitable torque and safety factor for the work. And the developed automatic remote exposure controller can control rpm of motor, pigtail position by photo-sensor and exposure time by timer to RF sensor. Thus, the developed equipment is expected that the unit can be used in many practical applications with benefits in economical advantage to combine the use of both automatic and manual type because attachment is possible existent manual remote exposure controller, AC and DC combined use

Control of occupational exposure using remote monitoring systems

Energy Technology Data Exchange (ETDEWEB)

Lunn, M. P. [British Energy Generation Ltd. Sizewell B Power Station, Leiston, Suffolk (United Kingdom)

2004-07-01

Advances in electronic dosimetry, portable radio technology and digital video have enabled the development of Remote Monitoring Systems (RMS) that provide a powerful dose control tool for the Operational Health Physicist. North American utilities have led the implementation of these systems, often with coverage of the entire plant, feeding back to a centralized control room. These large-scale systems typically cost around EURO 500,000. In Europe, and especially the UK, implementation of RMS technology has been slower and on a smaller scale. US utilities have justified the high capital cost of their systems by significantly reducing the number of contract RP technicians required during refuelling outages, saving up to EURO 1,000,000. In the UK, the number of contract RP technicians employed during outages is already minimal, and with the generally low dose rates found on Gas-Cooled Reactors, RP engineers have traditionally considered RMS to be an extravagance. However, the commissioning of the UK's first PWR and a significant increase in the number of AGR Vessel entries, have increased the radiological protection challenges facing the British Health Physicist, thus prompting a re-evaluation of this view. The benefit derived from a system that combines telemetry, video and voice communications is synergistic. We found that the system can be used in a variety of ways to significantly enhance radiological protection control in high radiation areas and to significantly reduce the dose received by RP staff covering such jobs. Indeed, it is estimated that the use of RMS saved at least 10 man.mSv of Radiological Protection dose during RF06 However, it is important to note that RMS is a monitoring tool to support existing monitoring techniques and arrangements. Suitably qualified and experienced staff are required to interpret the data and provide suitable advice to the work party. In addition, detailed training on the limitations of RMS, explicit procedures for

Research development of thermal aberration in 193nm lithography exposure system

Science.gov (United States)

Wang, Yueqiang; Liu, Yong

2014-08-01

Lithographic exposure is the key process in the manufacture of the integrated circuit, and the performance of exposure system decides the level of microelectronic manufacture technology. Nowadays, the 193nm ArF immersion exposure tool is widely used by the IC manufacturer. With the uniformity of critical dimension (CDU) and overlay become tighter and the requirement for throughput become higher, the thermal aberration caused by lens material and structure absorbing the laser energy cannot be neglected. In this paper, we introduce the efforts and methods that researcher on thermal aberration and its control. Further, these methods were compared to show their own pros and cons. Finally we investigated the challenges of thermal aberration control for state of the art technologies.

Practical methods for exposure control/management at nuclear facilities

International Nuclear Information System (INIS)

Twiggs, J.A.

1991-01-01

Exposure management/reduction is very important to Duke Power Company. Practical exposure control/reduction techniques applied to their reactor vessel head disassembly outage activity have consistently reduced personnel exposure for this task. The following exposure control methods have worked for use and will be the industry's direction for the 1990's. A summary of these methods includes: (a) move the responsibility of exposure management from the Radiation Protection group to the Maintenance group; (b) reduce area source term by removal of source; (c) improve working environments in radiation areas by minimizing protective clothing usage; and (d) maximize the use of electronic instruments to allow remote monitoring

Developmental exposure to fluoxetine modulates the serotonin system in hypothalamus.

Directory of Open Access Journals (Sweden)

Cecilia Berg

Full Text Available The selective serotonin reuptake inhibitor (SSRI fluoxetine (FLU, Prozac® is commonly prescribed for depression in pregnant women. This results in SSRI exposure of the developing fetus. However, there are knowledge gaps regarding the impact of SSRI exposure during development. Given the role of serotonin in brain development and its cross-talk with sex hormone function, we investigated effects of developmental exposure to pharmacologically relevant concentrations of FLU (3 and 30 nM (measured on brain neurotransmitter levels, gonadal differentiation, aromatase activity in brain and gonads, and the thyroid system, using the Xenopus tropicalis model. Tadpoles were chronically exposed (8 weeks until metamorphosis. At metamorphosis brains were cryosectioned and levels of serotonin, dopamine, norepinephrine, and their metabolites 5-hydroxyindoleacetic acid, 3,4-dihydroxyphenylacetic acid, and homovanillic acid were measured in discrete regions (telencephalon, hypothalamus and the reticular formation of the cryosections using high-performance liquid chromatography. Exposure to 30 nM FLU increased the concentration of 5-hydroxyindoleacetic acid in hypothalamus compared with controls. FLU exposure did not affect survival, time to metamorphosis, thyroid histology, gonadal sex differentiation, or aromatase activity implying that the effect on the serotonergic neurotransmitter system in the hypothalamus region was specific. The FLU concentration that impacted the serotonin system is lower than the concentration measured in umbilical cord serum, suggesting that the serotonin system of the developing brain is highly sensitive to in utero exposure to FLU. To our knowledge this is the first study showing effects of developmental FLU exposure on brain neurochemistry. Given that SSRIs are present in the aquatic environment the current results warrant further investigation into the neurobehavioral effects of SSRIs in aquatic wildlife.

Occupational exposure to radon progeny: Importance, experience with control, regulatory approaches

International Nuclear Information System (INIS)

Kraus, W.; Schwedt, J.

2002-01-01

An overview of possible occupational exposures to enhanced natural radiation in Germany is given, based on an analysis of the German Radiological Protection Commission. So far, the most significant exposure source is radon at underground and above ground workplaces. As a result of relevant regulations, in East Germany since the 70's a systematic monitoring of exposures to radon progeny has been introduced step by step in the uranium industry, in conventional ore mining, in show caves and mines, in enterprises for securing mining areas against subsidence, in radon spas and in water works in radon affected areas. Individual exposures have been assessed. The monitoring results for the period 1975-1998 are presented. Successful protection measures leading to a significant reduction of the exposures are discussed. using workplace monitoring results and registered occupancy times. In West Germany no regulations in this area were in force. Nevertheless, voluntary measuring programmes at similar workplaces were carried out. In case of unacceptable exposures successful protection measures were implemented. At present a systematic approach to control occupational exposures to radon is laid down in the European Directive 96/29/Euratom which has to be taken over in the national legislation to come. The expected number of workplaces to be included in the radiation protection system in Germany, the recommendable way of including different workplace types taking into account appropriate reference levels, and possible approaches to a graded system of workplace and individual monitoring are discussed in detail. (author)

Exposure to crystalline silica at Alberta work sites: review of controls.

Science.gov (United States)

Radnoff, Diane; Todor, Maria S; Beach, Jeremy

2015-01-01

From 2009 to 2013, Alberta Jobs, Skills, Training, and Labour (JSTL) conducted a project to evaluate exposure to crystalline silica and assess controls to protect workers. Information on exposure results has been previously reported; this article discusses the data collected on workplace controls. Information on work site controls was collected during exposure assessments consisting of qualitative information on controls in place and used by workers at the time of the assessments. Where there was sufficient data, the information was further analyzed to evaluate the impact of a particular control. While many types of controls were observed, they were not always effective or in use. The control available most often was respiratory protective equipment (RPE). Generally, when respirators were used, they were correctly selected for the level of measured exposure. However, not all workers who were potentially overexposed wore respirators at the time of the assessments. When the use of respirators was taken into account, about one-third of workers were still potentially exposed over the Alberta occupational exposure limit. The industries with the highest levels of exposure tended to be those with the most unprotected workers. Issues were identified with the use of improper work practices such as dry cleaning methods, lack of documented work procedures, poor housekeeping, and lack of training which may have contributed to worker exposure levels. There is a wide range in the efficacy of controls, particularly engineering controls. Most of the literature focuses on engineering controls; however administrative controls also play a role in reducing worker exposure. Data collected in this work indicated that simple changes to work procedures and behavior (such as improved housekeeping) may be effective, low-cost ways to reduce workplace exposure. More study is required to evaluate the impact and efficacy of administrative controls such as housekeeping and training. Employers

Development of personnel dose control system and whole body counter system

International Nuclear Information System (INIS)

Ooki, Yasushi; Harato, Kenji

2005-01-01

We delivered Personnel Dose Control System to Higashidohri nuclear plant of Tohoku Electric Power Company, in November 2004. In this system development, we automated the registration of radiation worker with close link between this system and Whole Body Counter System. In addition, this system enables the user to reduce workload for accumulation and notification of personal exposure data, because we adopted the system to extract the data effectively operating the terminal PC which the associate company gets ready in their office. We also delivered Whole body Counter System in December 2004, which was developed to measure internal exposure without feeling of oppression in chair-style device for the first time in Japan. This system enables non-operator system for measurement allowing workers to operate by themselves. (author)

Monitoring and control of occupational radiation exposure in Switzerland

International Nuclear Information System (INIS)

Moser, M.

1997-01-01

Occupational exposure is the most prominent example for the prolonged exposure to low level ionizing radiation characterized by low doses and dose rates. In this paper the occupational exposure in Switzerland is presented and the regulatory control of this exposure in the framework of the new radiation protection regulations is discussed. (author)

Is cosmic radiation exposure of air crew amenable to control?

International Nuclear Information System (INIS)

McEwan, A.C.

1999-01-01

ICRP Committee 4 currently has a Working Party on Cosmic Ray Exposure in Aircraft and Space Flight. It has assembled information on doses arising in aircraft and space flight and considered the appropriateness of the Commission's recommendations relating to air crew. A central issue is whether the exposures received should be considered amenable to control. Factors of relevance to the enhanced cosmic radiation exposure of air crew, and frequent fliers such as couriers, are doses to pregnant staff, the issue of controllability of doses, and the implementation of regulatory controls. It is concluded that while air crew in the current range of subsonic jet aircraft are exposed to enhanced levels of cosmic radiation, these exposures are not readily controllable nor likely to exceed about 6 mSv/y. The revised ICRP Recommendations in 1991 (ICRP 60) propose air crew be designated as occupationally exposed. However, none of the usual optimisation of dose actions associated with regulation of practices, such as classification of work areas and rules governing working procedures, can be implemented, and in practice the doses are not amenable to control. The International Basic Safety Standards therefore leave this designation to the judgement of national regulatory authorities. One requirement that stems from designation as occupational exposure is that of restriction of doses to pregnant women. Both from the points of view that it is questionable whether exposure of air crew can reasonably be considered to be amenable to control, and the magnitude of the risks from exposures incurred, there is little reason to invoke additional restrictions to limit exposures of pregnant air crew. Copyright (1999) Australasian Radiation Protection Society Inc

Miniature circulatory systems: A new exposure system for ecotoxicological effect assessments in riverine organisms.

Science.gov (United States)

Feiner, Mona; Beggel, Sebastian; Geist, Juergen

2016-11-01

Long-term effect assessments in ecotoxicological investigations are important, yet there is a lack of suitable exposure systems for these experiments that can be used for riverine species. A cost-efficient miniature circulatory system was developed that was evaluated for its applicability in long-term exposures in 2 stream-dwelling species: brown trout (Salmo trutta) and an amphipod (Gammarus roeseli). In an egg-to-fry exposure of S. trutta, the toxicity of 2 reverse osmosis concentrates was investigated as examples. Control hatching rate of yolk sac fry was 75 ± 7% and thus complies with the Organisation for Economic Co-operation and Development validity criterion (≥66%). The reverse osmosis concentrates did not impair the hatching rate in any tested concentration. In G. roeseli, mortality rates remained below 20% during a 21-d cultivation, fulfilling the common validity criterion in ecotoxicological testing. Mortality was significantly lower when the species was fed with conditioned alder leaves instead of an artificial shrimp food. Finally, a toxicity test on G. roeseli using copper as the test substance revealed median lethal concentration (LC50) values of 156 μg/L after 96 h and 99 μg/L after 264 h, which is in line with literature findings using other accepted exposure units. In conclusion, the miniature circulatory system provides a novel and cost-efficient exposure system for long-term investigations on riverine species that may also be applicable for other species of fishes and macroinvertebrates. Environ Toxicol Chem 2016;35:2827-2833. © 2016 SETAC. © 2016 SETAC.

Systems for animal exposure in full-scale fire tests

Science.gov (United States)

Hilado, C. J.; Cumming, H. J.; Kourtides, D. A.; Parker, J. A.

1977-01-01

Two systems for exposing animals in full-scale fire tests are described. Both systems involve the simultaneous exposure of two animal species, mice and rats, in modular units; determination of mortality, morbidity, and behavioral response; and analysis of the blood for carboxyhemoglobin. The systems described represent two of many possible options for obtaining bioassay data from full-scale fire tests. In situations where the temperatures to which the test animals are exposed can not be controlled, analytical techniques may be more appropriate than bioassay techniques.

Duration on the exposure control, spectra storage and texture goniometer handling in the software complex for the accumulation, control and supervising systems at the NSHR and the SKAT spectrometers (Tofa and Goni tasks)

International Nuclear Information System (INIS)

Kirilov, A.S.; Korobchenko, M.L.; Sirotin, A.P.; Heinitz, J.

1997-01-01

The VME-based accumulation, control and supervising system has been maintained at the NSHR spectrometer since March 1995. Another copy of system has been in use at the newly created SKAT spectrometer since April 1997. This paper is devoted to a detailed description of the user interface for the Join and the Tofa tasks which are dedicated to controlling the duration of the exposure, the spectra storage and handling the texture goniometer at the spectrometers. (author)

OSHA Bloodborne Pathogens Standards Exposure Control Plan

Science.gov (United States)

Luhrs, Caro Elise; Teitelbaum, Rita

1993-01-01

The Hummer Associates Exposure Control Plan is designed to reduce significant occupational exposure to bloodborne pathogens and infectious materials for Hummer Associates health care personnel. Under universal precautions, all patients and all body fluids are considered potentially infectious for bloodborne pathogens. Medical personnel need not be at increased risk if universal precautions are correctly understood and followed. This program covers all employees who could reasonably anticipate contact with blood or other potentially infectious materials during the performance of their job responsibilities. Although HIV and hepatitis B are mentioned most often, this program applies to all bloodborne diseases. The two main components needed to implement this program are universal precautions and engineering/work practice controls. This program covers all employees who may have occupational exposure to blood or other potentially infectious materials. Other aspects of this program are discussed.

A Radio Frequency Radiation Exposure System for Rodents based on Reverberation Chambers.

Science.gov (United States)

Capstick, Myles; Kuster, Niels; Kuehn, Sven; Berdinas-Torres, Veronica; Gong, Yijian; Wilson, Perry; Ladbury, John; Koepke, Galen; McCormick, David L; Gauger, James; Melnick, Ronald L

2017-08-01

In this paper we present the novel design features, their technical implementation, and an evaluation of the radio Frequency (RF) exposure systems developed for the National Toxicology Program (NTP) of the National Institute of Environmental Health Sciences (NIEHS) studies on the potential toxicity and carcinogenicity of 2nd and 3rd generation mobile-phone signals. The system requirements for this 2-year NTP cancer bioassay study were the tightly-controlled lifetime exposure of rodents (1568 rats and 1512 mice) to three power levels plus sham simulating typical daily, and higher, exposures of users of GSM and CDMA (IS95) signals. Reverberation chambers and animal housing were designed to allow extended exposure time per day for free-roaming individually-housed animals. The performance of the chamber was characterized in terms of homogeneity, stirred to unstirred energy, efficiency. The achieved homogeneity was 0.59 dB and 0.48 dB at 900 and 1900 MHz respectively. The temporal variation in the electric field strength was optimized to give similar characteristics to that of the power control of a phone in a real network using the two stirrers. Experimental dosimetry was performed to validate the SAR sensitivity and determine the SAR uniformity throughout the exposure volume; SAR uniformities of 0.46 dB and 0.40 dB, respectively, for rats and mice were achieved.

Development and evaluation of an Exposure Control Efficacy Library (ECEL)

NARCIS (Netherlands)

Fransman, W.; Schinkel, J.; Meijster, T.; Hemmen, J. van; Tielemans, E.; Goede, H.

2008-01-01

Objectives: This paper describes the development and evaluation of an evidence database on the effectiveness of risk management measures (RMMs) to control inhalation exposure. This database is referred to as Exposure Control Efficacy Library (ECEL). Methods: A comprehensive review of scientific

Retrospective exposure assessment and quality control in an international multi-centre case-control study

DEFF Research Database (Denmark)

Tinnerberg, H; Heikkilä, P; Huici-Montagud, A

2003-01-01

The paper presents the exposure assessment method and quality control procedure used in an international, multi-centre case-control study within a joint Nordic and Italian cohort. This study was conducted to evaluate whether occupational exposure to carcinogens influenced the predictivity of high...... was higher among the original assessors (the assessor from the same country as the subject) than the average prevalence assessed by the other four in the quality control round. The original assessors classified more job situations as exposed than the others. Several reasons for this are plausible: real...... country-specific differences, differences in information available to the home assessor and the others and misunderstandings or difficulties in translation of information. To ensure the consistency of exposure assessments in international retrospective case-control studies it is important to have a well...

Computer-controlled radiation monitoring system

International Nuclear Information System (INIS)

Homann, S.G.

1994-01-01

A computer-controlled radiation monitoring system was designed and installed at the Lawrence Livermore National Laboratory's Multiuser Tandem Laboratory (10 MV tandem accelerator from High Voltage Engineering Corporation). The system continuously monitors the photon and neutron radiation environment associated with the facility and automatically suspends accelerator operation if preset radiation levels are exceeded. The system has proved reliable real-time radiation monitoring over the past five years, and has been a valuable tool for maintaining personnel exposure as low as reasonably achievable

A practical method to standardise and optimise the Philips DoseRight 2.0 CT automatic exposure control system.

Science.gov (United States)

Wood, T J; Moore, C S; Stephens, A; Saunderson, J R; Beavis, A W

2015-09-01

Given the increasing use of computed tomography (CT) in the UK over the last 30 years, it is essential to ensure that all imaging protocols are optimised to keep radiation doses as low as reasonably practicable, consistent with the intended clinical task. However, the complexity of modern CT equipment can make this task difficult to achieve in practice. Recent results of local patient dose audits have shown discrepancies between two Philips CT scanners that use the DoseRight 2.0 automatic exposure control (AEC) system in the 'automatic' mode of operation. The use of this system can result in drifting dose and image quality performance over time as it is designed to evolve based on operator technique. The purpose of this study was to develop a practical technique for configuring examination protocols on four CT scanners that use the DoseRight 2.0 AEC system in the 'manual' mode of operation. This method used a uniform phantom to generate reference images which form the basis for how the AEC system calculates exposure factors for any given patient. The results of this study have demonstrated excellent agreement in the configuration of the CT scanners in terms of average patient dose and image quality when using this technique. This work highlights the importance of CT protocol harmonisation in a modern Radiology department to ensure both consistent image quality and radiation dose. Following this study, the average radiation dose for a range of CT examinations has been reduced without any negative impact on clinical image quality.

The passive control of air pollution exposure in Dublin, Ireland: a combined measurement and modelling case study.

Science.gov (United States)

Gallagher, J; Gill, L W; McNabola, A

2013-08-01

This study investigates the potential real world application of passive control systems to reduce personal pollutant exposure in an urban street canyon in Dublin, Ireland. The implementation of parked cars and/or low boundary walls as a passive control system has been shown to minimise personal exposure to pollutants on footpaths in previous investigations. However, previous research has been limited to generic numerical modelling studies. This study combines real-time traffic data, meteorological conditions and pollution concentrations, in a real world urban street canyon before and after the implementation of a passive control system. Using a combination of field measurements and numerical modelling this study assessed the potential impact of passive controls on personal exposure to nitric oxide (NO) concentrations in the street canyon in winter conditions. A calibrated numerical model of the urban street canyon was developed, taking into account the variability in traffic and meteorological conditions. The modelling system combined the computational fluid dynamic (CFD) simulations and a semi-empirical equation, and demonstrated a good agreement with measured field data collected in the street canyon. The results indicated that lane distribution, fleet composition and vehicular turbulence all affected pollutant dispersion, in addition to the canyon geometry and local meteorological conditions. The introduction of passive controls displayed mixed results for improvements in air quality on the footpaths for different wind and traffic conditions. Parked cars demonstrated the most comprehensive passive control system with average improvements in air quality of up to 15% on the footpaths. This study highlights the potential of passive controls in a real street canyon to increase dispersion and improve air quality at street level. Copyright © 2013 Elsevier B.V. All rights reserved.

Exposure of eyes to perfume: a double-blind, placebo-controlled experiment.

Science.gov (United States)

Elberling, J; Duus Johansen, J; Dirksen, A; Mosbech, H

2006-08-01

Environmental perfume exposure can elicit bothersome respiratory symptoms. Symptoms are induced at exposure levels which most people find tolerable, and the mechanisms are unclear. The aim of the study was to investigate patients with eye and respiratory symptoms related to environmental perfume, by exposing the eyes to perfume in a double-blind, placebo-controlled study.Twenty-one eczema patients with respiratory symptoms elicited by perfume were compared with 21 healthy volunteers in a sex- and age-matched case-control study. The participants completed a symptom questionnaire, and underwent a double-blind, placebo-controlled exposure to perfume. Of the 42 individuals tested, 10 had more eye symptoms (irritation, itching, and tears) during perfume exposure than during placebo exposures, and eight of these individuals (P = 0.07, Fisher's exact test) belonged to the patient group. A true positive eye reaction to perfume was significantly associated with identification of perfume as an active exposure (P perfume elicited irritation in the eyes independently of olfaction, but the relative importance of ocular chemoperception in relation to elicitation of respiratory symptoms from common environmental exposures to perfume remains unclear. We investigated the hypothesis of an association between respiratory symptoms related to perfume and ocular perfume sensitivity by exposing the eyes to perfume in a double blind, placebo-controlled experiment. Vapors of perfume provoked symptoms in the relevant eye in some patients and healthy control persons, but under our exposure conditions, ocular chemesthesis failed to elicit respiratory symptoms.

Protection of the public in situations of prolonged radiation exposure. The application of the Commission's system of radiological protection to controllable radiation exposure due to natural sources and long-lived radioactive residues.

Science.gov (United States)

1999-01-01

This report provides guidance on the application of the ICRP system of radiological protection to prolonged exposure situations affecting members of the public. It addresses the general application of the Commission's system to the control of prolonged exposures resulting from practices and to the undertaking of interventions in prolonged exposure situations. Additionally, it provides recommendations on generic reference levels for such interventions. The report also considers some specific situations and discusses a number of issues that have been of concern, namely: natural radiation sources that may give rise to high doses; the restoration and rehabilitation of sites where human activities involving radioactive substances have been carried out; the return to 'normality' following an accident that has released radioactive substances to the environment; and the global marketing of commodities for public consumption that contain radioactive substances. Annexes provide some examples of prolonged exposure situations and discuss the radiological protection quantities, radiation-induced health effects and aspects of the Commission's system of radiological protection relevant to prolonged exposure. Quantitative recommendations for prolonged exposures are provided in the report. They must be interpreted with extreme caution; Chapters 4 and 5 stress the upper bound nature of the following values: Generic reference levels for intervention, in terms of existing total annual doses, are given as < approximately 100 mSv, above which intervention is almost always justifiable (situations for which the annual dose threshold for deterministic effects in relevant organs is exceeded will almost always require intervention), and < approximately 10 mSv, below which intervention is not likely to be justifiable (and above which it may be necessary). Intervention exemption levels for commodities, especially building materials, are expressed as an additional annual dose of approximately 1

A preliminary study into performing routine tube output and automatic exposure control quality assurance using radiology information system data

International Nuclear Information System (INIS)

Charnock, P.; Jones, R.; Fazakerley, J.; Wilde, R.; Dunn, A. F.

2011-01-01

Data are currently being collected from hospital radiology information systems in the North West of the UK for the purposes of both clinical audit and patient dose audit. Could these data also be used to satisfy quality assurance (QA) requirements according to UK guidance? From 2008 to 2009, 731 653 records were submitted from 8 hospitals from the North West England. For automatic exposure control QA, the protocol from Inst. of Physics and Engineering in Medicine (IPEM) report 91 recommends that milli amperes per second can be monitored for repeatability and reproducibility using a suitable phantom, at 70-81 kV. Abdomen AP and chest PA examinations were analysed to find the most common kilo voltage used with these records then used to plot average monthly milli amperes per second with time. IPEM report 91 also recommends that a range of commonly used clinical settings is used to check output reproducibility and repeatability. For each tube, the dose area product values were plotted over time for two most common exposure factor sets. Results show that it is possible to do performance checks of AEC systems; however more work is required to be able to monitor tube output performance. Procedurally, the management system requires work and the benefits to the workflow would need to be demonstrated. (authors)

The passive control of air pollution exposure in Dublin, Ireland: A combined measurement and modelling case study

International Nuclear Information System (INIS)

Gallagher, J.; Gill, L.W.; McNabola, A.

2013-01-01

This study investigates the potential real world application of passive control systems to reduce personal pollutant exposure in an urban street canyon in Dublin, Ireland. The implementation of parked cars and/or low boundary walls as a passive control system has been shown to minimise personal exposure to pollutants on footpaths in previous investigations. However, previous research has been limited to generic numerical modelling studies. This study combines real-time traffic data, meteorological conditions and pollution concentrations, in a real world urban street canyon before and after the implementation of a passive control system. Using a combination of field measurements and numerical modelling this study assessed the potential impact of passive controls on personal exposure to nitric oxide (NO) concentrations in the street canyon in winter conditions. A calibrated numerical model of the urban street canyon was developed, taking into account the variability in traffic and meteorological conditions. The modelling system combined the computational fluid dynamic (CFD) simulations and a semi-empirical equation, and demonstrated a good agreement with measured field data collected in the street canyon. The results indicated that lane distribution, fleet composition and vehicular turbulence all affected pollutant dispersion, in addition to the canyon geometry and local meteorological conditions. The introduction of passive controls displayed mixed results for improvements in air quality on the footpaths for different wind and traffic conditions. Parked cars demonstrated the most comprehensive passive control system with average improvements in air quality of up to 15% on the footpaths. This study highlights the potential of passive controls in a real street canyon to increase dispersion and improve air quality at street level. - Highlights: • Parked cars and LBWs were assessed as passive controls in an urban street canyon. • The calibrated model combined CFD

The passive control of air pollution exposure in Dublin, Ireland: A combined measurement and modelling case study

Energy Technology Data Exchange (ETDEWEB)

Gallagher, J., E-mail: j.gallagher@bangor.ac.uk [School of Energy, Natural Resources and Geography, Bangor University (United Kingdom); Gill, L.W.; McNabola, A. [Dept. of Civil, Structural and Environmental Engineering, Trinity College Dublin (Ireland)

2013-08-01

This study investigates the potential real world application of passive control systems to reduce personal pollutant exposure in an urban street canyon in Dublin, Ireland. The implementation of parked cars and/or low boundary walls as a passive control system has been shown to minimise personal exposure to pollutants on footpaths in previous investigations. However, previous research has been limited to generic numerical modelling studies. This study combines real-time traffic data, meteorological conditions and pollution concentrations, in a real world urban street canyon before and after the implementation of a passive control system. Using a combination of field measurements and numerical modelling this study assessed the potential impact of passive controls on personal exposure to nitric oxide (NO) concentrations in the street canyon in winter conditions. A calibrated numerical model of the urban street canyon was developed, taking into account the variability in traffic and meteorological conditions. The modelling system combined the computational fluid dynamic (CFD) simulations and a semi-empirical equation, and demonstrated a good agreement with measured field data collected in the street canyon. The results indicated that lane distribution, fleet composition and vehicular turbulence all affected pollutant dispersion, in addition to the canyon geometry and local meteorological conditions. The introduction of passive controls displayed mixed results for improvements in air quality on the footpaths for different wind and traffic conditions. Parked cars demonstrated the most comprehensive passive control system with average improvements in air quality of up to 15% on the footpaths. This study highlights the potential of passive controls in a real street canyon to increase dispersion and improve air quality at street level. - Highlights: • Parked cars and LBWs were assessed as passive controls in an urban street canyon. • The calibrated model combined CFD

GPU Nuclear Corporation's radiation exposure management system

International Nuclear Information System (INIS)

Slobodien, M.J.; Bovino, A.A.; Perry, O.R.; Hildebrand, J.E.

1984-01-01

GPU Nuclear Corporation has developed a central main frame (IBM 3081) based radiation exposure management system which provides real time and batch transactions for three separate reactor facilities. The structure and function of the data base are discussed. The system's main features include real time on-line radiation work permit generation and personnel exposure tracking; dose accountability as a function of system and component, job type, worker classification, and work location; and personnel dosemeter (TLD and self-reading pocket dosemeters) data processing. The system also carries the qualifications of all radiation workers including RWP training, respiratory protection training, results of respirator fit tests and medical exams. A warning system is used to prevent non-qualified persons from entering controlled areas. The main frame system is interfaced with a variety of mini and micro computer systems for dosemetry, statistical and graphics applications. These are discussed. Some unique dosemetry features which are discussed include assessment of dose for up to 140 parts of the body with dose evaluations at 7,300 and 1000 mg/cm 2 for each part, tracking of MPC hours on a 7 day rolling schedule; automatic pairing of TLD and self-reading pocket dosemeter values, creation and updating of NRC Forms 4 and 5, generation of NRC required 20.407 and Reg Guide 1.16 reports. As of July 1983, over 20 remote on-line stations were in use with plans to add 20-30 more by May 1984. The system provides response times for on-line activities of 2-7 seconds and 23 1/2 hours per day ''up time''. Examples of the various on-line and batch transactions are described

Styrene vapor control systems in FRP yacht plants.

Science.gov (United States)

Todd, W F

1985-01-01

The production of large (greater than 25-ft) fiber-reinforced plastic (FRP) yachts has presented problems of styrene exposure in excess of the Occupational Safety and Health Administration permissible exposure level (OSHA PEL) of 100 ppm. Also, the National Institute for Occupational Safety and Health (NIOSH) is currently recommending a 10-hour workshift, 40-hour workweek time weighted average (TWA) of 50 ppm for styrene. Meeting this challenge will require a system of engineering, work practice, personal protective equipment, and monitoring control measures. NIOSH has performed a study of the engineering controls in three FRP yacht plants. Work practices and the use of personal protective equipment (PPE) were also considered in the evaluation. The three systems evaluated included a dilution system, a local ventilation system, and a push-pull ventilation system. The cost of constructing and operating these systems was not evaluated in this study. Study results indicated that each type of ventilation system can meet the present PEL of 100 ppm styrene; however, it is not certain that these systems can meet a lower PEL of 50 ppm styrene.

Administrative and research needs associated with the control of occupational exposures in commercial nuclear power plants

International Nuclear Information System (INIS)

Moeller, D.W.

1980-01-01

This review of occupational exposures in commercial nuclear power plants in the United States of America has revealed that, although many problem areas are being adequately addressed, there is a need for additional work. Areas relative to exposure evaluation that need attention include better data collection and analysis as to when and where exposures occur, improved information on exposures from internally deposited radionuclides, improved techniques for monitoring occupational neutron exposures, and an upgrading in quality control procedures in the manufacture, calibration, use and maintenance of monitoring instruments. Areas relative to exposure control that need attention include the development of additional design and manufacturing approaches for preventing the production and build-up of key radionuclides within reactor cooling systems, the development and testing of techniques for removing those radionuclides that do accumulate in such systems, the application of risk/benefit assessments to procedures for the maintenance, repair, modification, replacement and disposal of major nuclear power plant components, such as steam generators, and the development of design features to facilitate the decommissioning of nuclear power plants. Professional radiation workers also have to be aware of the impact that the proposed major reductions in occupational dose limits would have on their operations. This impact is compounded by the fact that the number of people receiving graduate education in radiation protection in the USA is decreasing. (author)

The change of β-adrenergic system after cessation of lead exposure

International Nuclear Information System (INIS)

Chang, H.-R.; Tsao, D.-A.; Yu, H.-S.; Ho, C.-K.

2005-01-01

For understanding a reversible or irreversible harm of β-adrenergic system in lead induced cardiovascular disease (hypertension), We set up animal model to estimate the change of blood pressure and sympathetic nervous system after lead exposure withdrawn in the study. We address three topics in this study: (a) the relationship between withdrawal time of lead exposure and β-adrenergic receptor, plasma catecholamine level, blood pressure, and lead level in heart, aorta, and kidney in lead-induced hypertensive rats after lead exposure stopped; (b) the relationship between blood pressure and β-adrenergic receptor in heart, aorta, and kidney; (c) the estimation of relationship between lead withdrawn and the variation of β-adrenergic system. Wistar rats were chronically fed with 2% lead acetate (experimental group) and water (control group) for 2 months. The rats were divided into 8 groups by withdrawal time of lead exposure stopped. Plasma catecholamine level was measured by high-performance liquid chromatography. Radioligand binding assay was measured by a method that fulfilled strict criteria of β-adrenergic receptor using the ligand [ 125 I]iodocyanopindolol. The levels of lead were determined by electrothermal atomic absorption spectrometry. The results showed that a close relation between reduced lead level and the plasma catecholamine level decreased, aorta β-adrenergic receptor increased, kidney β-adrenergic receptor diminished, heart β-adrenergic receptor increased, and blood pressure dropped after lead exposure withdrawn. The study on the regulation of β-adrenergic system in lead-induced hypertension after lead withdrawn might also provide insight about the nature of this disease state

Fast exposure time decision in multi-exposure HDR imaging

Science.gov (United States)

Piao, Yongjie; Jin, Guang

2012-10-01

Currently available imaging and display system exists the problem of insufficient dynamic range, and the system cannot restore all the information for an high dynamic range (HDR) scene. The number of low dynamic range(LDR) image samples and fastness of exposure time decision impacts the real-time performance of the system dramatically. In order to realize a real-time HDR video acquisition system, this paper proposed a fast and robust method for exposure time selection in under and over exposure area which is based on system response function. The method utilized the monotony of the imaging system. According to this characteristic the exposure time is adjusted to an initial value to make the median value of the image equals to the middle value of the system output range; then adjust the exposure time to make the pixel value on two sides of histogram be the middle value of the system output range. Thus three low dynamic range images are acquired. Experiments show that the proposed method for adjusting the initial exposure time can converge in two iterations which is more fast and stable than average gray control method. As to the exposure time adjusting in under and over exposed area, the proposed method can use the dynamic range of the system more efficiently than fixed exposure time method.

Integrated occupational radiation exposure information system

International Nuclear Information System (INIS)

Hunt, H.W.

1983-06-01

The integrated (Occupational Radiation Exposure) data base information system has many advantages. Radiation exposure information is available to operating management in a more timely manner and in a more flexible mode. The ORE system has permitted the integration of scattered files and data to be stored in a more cost-effective method that permits easy and simultaneous access by a variety of users with different data needs. The external storage needs of the radiation exposure source documents are several orders of magnitude less through the use of the computer assisted retrieval techniques employed in the ORE system. Groundwork is being layed to automate the historical files, which are maintained to help describe the radiation protection programs and policies at any one point in time. The file unit will be microfilmed for topical indexing on the ORE data base

Operation control device under radiation exposure

International Nuclear Information System (INIS)

Kimura, Kiichi; Murakami, Toichi.

1994-01-01

The device of the present invention performs smooth progress of operation by remote control for a plurality of operations in periodical inspections in controlled areas of a nuclear power plant, thereby reducing the operator's exposure dose. Namely, the device monitors the progressing state of the operation by displaying the progress of operation on a CRT of a centralized control device present in a low dose area remote from an operation field through an ITV camera disposed in the vicinity of the operation field. Further, operation sequence and operation instruction procedures previously inputted in the device are indicated to the operation field through an operation instruction outputting device (field CRT) in accordance with the progress of the operation steps. On the other hand, the operation progress can be aided by inputting information from the operation field such as start or completion of the operation steps. Further, the device of the present invention can monitor the change of operation circumstances and exposure dose of operators based on the information from a radiation dose measuring device disposed in the operation circumstance and to individual operators. (I.S.)

Leptospira Exposure and Gardeners: A Case-Control Seroprevalence Study

Science.gov (United States)

Alvarado-Esquivel, Cosme; Hernandez-Tinoco, Jesus; Sanchez-Anguiano, Luis Francisco; Ramos-Nevarez, Agar; Cerrillo-Soto, Sandra Margarita; Guido-Arreola, Carlos Alberto

2016-01-01

Background Leptospira can be found in soil. However, it is unclear whether occupational exposure to soil may represent a risk for Leptospira infection in humans. Therefore, we sought to determine the association of Leptospira IgG seroprevalence with the occupation of gardener, and to determine the epidemiological characteristics of gardeners associated with Leptospira exposure. Methods We performed a case-control study in 168 gardeners and 168 age- and gender-matched control subjects without gardening occupation in Durango City, Mexico. The seroprevalence of anti-Leptospira IgG antibodies in cases and controls was determined using an enzyme immunoassay. Bivariate and multivariate analyses were used to assess the association of Leptospira exposure and the characteristics of the gardeners. Results Anti-Leptospira IgG antibodies were found in 10 (6%) of 168 gardeners and in 15 (8.9%) of 168 control subjects (odds ratio (OR): 0.64; 95% confidence interval (CI): 0.28 - 1.48; P = 0.40). Multivariate analysis showed that Leptospira seropositivity was positively associated with female gender (OR: 5.82; 95% CI: 1.11 - 30.46; P = 0.03), and negatively associated with eating while working (OR: 0.21; 95% CI: 0.05 - 0.87; P = 0.03). In addition, multivariate analysis showed that high anti-Leptospira levels were associated with consumption of boar meat (OR: 28.00; 95% CI: 1.20 - 648.80; P = 0.03). Conclusions This is the first case-control study of Leptospira exposure in gardeners. Results do not support an association of Leptospira exposure with the occupation of gardener. However, further studies to confirm the lack of this association are needed. The potential role of consumption of boar meat in Leptospira infection deserves further investigation. PMID:26668679

Criteria for inhalation exposure systems utilizing concurrent flow spirometry

International Nuclear Information System (INIS)

Raabe, O.G.; Yeh, H.C.

1974-01-01

Principles are given for the design and operation of a new class of inhalation exposure systems utilizing concurrent flow spirometry (CFS), a simple method for providing realtime measurement of respiratory volumes and rates during inhalation exposure by mouth or nose of individual experimental animals or man to aerosols or gases. This technique is especially useful for inhalation exposure of larger experimental animals, such as horses, where whole-body plethysmography is usually impractical. Difficulties encountered with conventional exposure systems in maintenance of uniform aerosol or gas concentrations and prevention of large pressure excursions in the exposure chamber during breathing are obviated by systems utilizing the principles of concurrent flow spirometry. For illustration, two exposure units with CFS are described, one for exposure of Beagle dogs and one for ponies. (U.S.)

EMPLACEMENT DRIFT ISOLATION DOOR CONTROL SYSTEM

International Nuclear Information System (INIS)

N.T. Raczka

1998-01-01

The purpose of this analysis is to review and refine key design concepts related to the control system presently under consideration for remotely operating the emplacement drift isolation doors at the potential subsurface nuclear waste repository at Yucca Mountain. This analysis will discuss the key design concepts of the control system that may be utilized for remotely monitoring, opening, and closing the emplacement drift isolation doors. The scope and primary objectives of this analysis are to: (1) Discuss the purpose and function of the isolation doors (Presented in Section 7.1). (2) Review the construction of the isolation door and other physical characteristics of the doors that the control system will interface with (Presented in Section 7.2). (3) Discuss monitoring and controlling the operation of the isolation doors with a digital control system (either a Programmable Logic Controller (PLC) system or a Distributed Control System (DCS)) (Presented in Section 7.3). (4) Discuss how all isolation doors can be monitored and controlled from a subsurface central control center (Presented in Section 7.4). This analysis will focus on the development of input/output (I/O) counts including the types of I/O, redundancy and fault tolerance considerations, and processor requirements for the isolation door control system. Attention will be placed on operability, maintainability, and reliability issues for the system operating in the subsurface environment with exposure to high temperatures and radiation

Automatic exposure control systems designed to maintain constant image noise: effects on computed tomography dose and noise relative to clinically accepted technique charts.

Science.gov (United States)

Favazza, Christopher P; Yu, Lifeng; Leng, Shuai; Kofler, James M; McCollough, Cynthia H

2015-01-01

To compare computed tomography dose and noise arising from use of an automatic exposure control (AEC) system designed to maintain constant image noise as patient size varies with clinically accepted technique charts and AEC systems designed to vary image noise. A model was developed to describe tube current modulation as a function of patient thickness. Relative dose and noise values were calculated as patient width varied for AEC settings designed to yield constant or variable noise levels and were compared to empirically derived values used by our clinical practice. Phantom experiments were performed in which tube current was measured as a function of thickness using a constant-noise-based AEC system and the results were compared with clinical technique charts. For 12-, 20-, 28-, 44-, and 50-cm patient widths, the requirement of constant noise across patient size yielded relative doses of 5%, 14%, 38%, 260%, and 549% and relative noises of 435%, 267%, 163%, 61%, and 42%, respectively, as compared with our clinically used technique chart settings at each respective width. Experimental measurements showed that a constant noise-based AEC system yielded 175% relative noise for a 30-cm phantom and 206% relative dose for a 40-cm phantom compared with our clinical technique chart. Automatic exposure control systems that prescribe constant noise as patient size varies can yield excessive noise in small patients and excessive dose in obese patients compared with clinically accepted technique charts. Use of noise-level technique charts and tube current limits can mitigate these effects.

Clementine auto exposure control software

Energy Technology Data Exchange (ETDEWEB)

Arnold, E. [Lawrence Livermore National Lab., CA (United States)

1994-11-15

The primary mission of the Clementine program was to test technology developed under the auspices of BMDO (the Ballistic Missile Defense Organization). A secondary goal of the program was to provide astronomical data to the scientific and educational community. The mission plan developed to accomplish these goals included complete mapping of the lunar surface and a close fly-by of a near-Earth asteroid, 1620 Geographos. Exposure control for the Clementine mission was driven by mission phase requirements and sensor characteristics. Thus, there were a total of twelve algorithms developed for three primary mission phases and the four imaging sensors (two additional sensors operated as star trackers). The three mission phases in question were lunar mapping, distant observation of the asteroid for the purpose of tracking, and close-up viewing (as close as 100 Km) of Geographos. The four non-star tracker sensors consisted of an Ultra Violet/Visible (UV/Vis) camera, a High Resolution (HiRes) camera with a built-in LIDAR (Light Detection And Ranging) unit, a Near Infrared (NIR) camera, and a Long Wave InfraRed (LWIR) camera. Due to lack of test time and uncertainties about the imaging environment, numerous input parameters were provided in the algorithms to allow extensive tuning of the exposure control during the mission.

EXPOSURE ANALYSIS MODELING SYSTEM (EXAMS): USER MANUAL AND SYSTEM DOCUMENTATION

Science.gov (United States)

The Exposure Analysis Modeling System, first published in 1982 (EPA-600/3-82-023), provides interactive computer software for formulating aquatic ecosystem models and rapidly evaluating the fate, transport, and exposure concentrations of synthetic organic chemicals - pesticides, ...

Systemic contact dermatitis after oral exposure to nickel

DEFF Research Database (Denmark)

Jensen, Christian Stab; Menné, Torkil; Johansen, Jeanne Duus

2006-01-01

Systemic contact dermatitis can be elicited experimentally in nickel-sensitive individuals by oral nickel exposure. A crucial point interpreting such experiments has been the relevance of nickel exposure from drinking water and diet. The aim of this meta-analysis study on former nickel......-exposure investigations was to provide the best possible estimation of threshold values of nickel doses that may cause systemic contact dermatitis in nickel-sensitive patients. 17 relevant investigations were identified, and statistical analyses were performed in a stepwise procedure. 9 studies were included in the final...... of the doses that, theoretically, would cause systemic contact dermatitis in exposed nickel-sensitive patients. The results from the 2 most sensitive groups show that 1% of these individuals may react with systemic contact dermatitis at normal daily nickel exposure from drinking water and diet, i.e. 0...

Dose budget for exposure control

International Nuclear Information System (INIS)

Nair, P.S.

1999-01-01

Dose budget is an important management tool to effectively control the collective dose incurred in a nuclear facility. The budget represents a set of yardsticks or guidelines for use in controlling the internal activities, involving radiation exposure in the organisation. The management, through budget can evaluate the radiation protection performance at every level of the organisation where a number of independent functional groups work on routine and non-routine jobs. The discrepancy between the plan and the actual performance is high lighted through the budgets. The organisation may have to change the course of its operation in a particular area or revise its plan with due focus on appropriate protective measures. (author)

Systemic Absorption of Nanomaterials by Oral Exposure

DEFF Research Database (Denmark)

Binderup, Mona-Lise; Bredsdorff, Lea; Beltoft, Vibe Meister

This report and accompanying database systematically evaluates the reliability and relevance of the existing scientific literature regarding systemic absorption of nanomaterials by oral exposure and makes specific recommendations for future testing approaches.......This report and accompanying database systematically evaluates the reliability and relevance of the existing scientific literature regarding systemic absorption of nanomaterials by oral exposure and makes specific recommendations for future testing approaches....

Negative control exposure studies in the presence of measurement error: implications for attempted effect estimate calibration.

Science.gov (United States)

Sanderson, Eleanor; Macdonald-Wallis, Corrie; Davey Smith, George

2018-04-01

Negative control exposure studies are increasingly being used in epidemiological studies to strengthen causal inference regarding an exposure-outcome association when unobserved confounding is thought to be present. Negative control exposure studies contrast the magnitude of association of the negative control, which has no causal effect on the outcome but is associated with the unmeasured confounders in the same way as the exposure, with the magnitude of the association of the exposure with the outcome. A markedly larger effect of the exposure on the outcome than the negative control on the outcome strengthens inference that the exposure has a causal effect on the outcome. We investigate the effect of measurement error in the exposure and negative control variables on the results obtained from a negative control exposure study. We do this in models with continuous and binary exposure and negative control variables using analysis of the bias of the estimated coefficients and Monte Carlo simulations. Our results show that measurement error in either the exposure or negative control variables can bias the estimated results from the negative control exposure study. Measurement error is common in the variables used in epidemiological studies; these results show that negative control exposure studies cannot be used to precisely determine the size of the effect of the exposure variable, or adequately adjust for unobserved confounding; however, they can be used as part of a body of evidence to aid inference as to whether a causal effect of the exposure on the outcome is present.

Designing, Constructing and Installing a Local Exhaust Ventilation System to Minimize Welders\\' Exposure to Welding Fumes

Directory of Open Access Journals (Sweden)

Sajad Zare

2017-10-01

Full Text Available Background & Aims of the Study: Welder’s exposure to welding fumes can cause occupational diseases. The current study sought to examine exposure to welding fumes among welders who work in the repair shop of Sarcheshmeh Copper Complex and design a local exhaust ventilation system to control exposure to welding fumes. Materials & Methods: This applied analytical study was conducted in the summer of 2016 among welders working in the repair shop of Sarcheshmeh Copper Complex. The study comprised three phases; in the first one, welders’ exposure to welding fumes was assessed at the beginning of the study. After that, a local exhaust ventilation system was designed and installed in the aforementioned repair shop. In the final stage, welders’ exposure to welding fumes was assessed again after installation of the ventilation system. The procedure recommended by NIOSH (method number 7300 was used for individual sampling of welders. Results: Based on the obtained findings, before installing the ventilation system, welding technicians were exposed to 0.3 mg/m3 of copper fumes and 0.04 mg/m3 of chromium fumes. Journeyman welders were also exposed to 2.16 mg/m3 of manganese fumes, while stellar welders were exposed to 6.9 mg/m3 of iron fumes. In the light of these measurements, a local exhaust ventilation system was designed and installed. Subsequently, measurement of exposure to welding fumes showed a significant reduction. That is, welding technicians were exposed to 0.17 mg/m3 and 0.015 mg/m3 of copper and chromium fumes respectively. Additionally, journeyman welders were exposed to 0.86 mg/m3 of manganese fumes, whereas stellar welders were exposed to 4.3 mg/m3 of iron fumes. Conclusions: A comparison of standard limits of exposure to welding fumes and the results obtained from measurements in sampling stations before and after the installation of the local exhaust ventilation system reveals that this controlling measure was very effective in the

Laboratory electron exposure of TSS-1 thermal control coating

Science.gov (United States)

Vaughn, J. A.; Mccollum, M.; Carruth, M. R., Jr.

1995-01-01

RM400, a conductive thermal control coating, was developed for use on the exterior shell of the tethered satellite. Testing was performed by the Engineering Physics Division to quantify effects of the space environment on this coating and its conductive and optical properties. Included in this testing was exposure of RM400 to electrons with energies ranging from 0.1 to 1 keV, to simulate electrons accelerated from the ambient space plasma when the tethered satellite is fully deployed. During this testing, the coating was found to luminesce, and a prolonged exposure of the coating to high-energy electrons caused the coating to darken. This report describes the tests done to quantify the degradation of the thermal control properties caused by electron exposure and to measure the luminescence as a function of electron energy and current density to the satellite.

Is occupational exposure to solvents associated with an increased risk for developing systemic scleroderma?

Directory of Open Access Journals (Sweden)

Drexler Hans

2006-07-01

Full Text Available Abstract Background Our study was aimed to investigate in a German collective if there are any hints for an increased occupational or environmental risk to develop systemic sclerosis, especially, focussing on work-related exposure to solvents. Moreover, we tried to evaluate the feasibility of a sampling method addressing support groups. Methods A standardised questionnaire was published in two journals subscribed by members of two different support groups and all members were asked to complete the questionnaire and to return it anonymously. The subjects were not informed on the scientific hypotheses, nor did they know who of them belonged to the case group (scleroderma or to the control group (multiple sclerosis. Results 175 questionnaires could be included in the statistical analysis. As expected, a female predominance was in our collective. In the male subpopulation, the occupational exposure to solvents was higher in the case group than in the control-group (70% versus 45.8%. Based only on the male subgroup, a tendency for an association between occupational exposure to solvents and the risk to develop systemic sclerosis was found. Conclusion According to our experience in this case-control-study exposure misclassification, qualitative or quantitative, was an eminent problem. Within such a setting, it is generally very difficult to establish an exact dose-response relationship due to incomplete, imprecise or missing data concerning duration of exposure, frequency of use and kind of solvent. Additionally, a well-known problem in studies based on self-reported questionnaires is the so-called volunteer bias. Unfortunately, but similar to other studies assessing epidemiologic factors in such a rare disease, our study was of limited power, especially in the subgroups defined by gender.

A Study on the Exposure Parameter and the Patient Dose for Digital Radiography System in Daegoo

International Nuclear Information System (INIS)

Jo, Gwang Ho; Kang, Yeopng Han; Kim, Bu Sun

2008-01-01

Digital imaging for general radiography has many advantages over the film/screen systems, including a wider dynamic range and the ability to manipulate the images produced. The wider range means that acceptable images may by acquired at a range of dose levels, and therefore repeat exposures can be reduced. Digital imaging can result in the over use of radiation, however, because there is a tendency can be reduced. Digital imaging can result in the over use of radiation, however, because there is a tendency for images to be acquired at too high a dose. We investigated the actual exposure dose conditions on general radiography and a questionnaire survey was conducted with radiotechnologiest at medical institutions using digital radiology system. As a results, the dose of exposure was not controlled with patient's figure and dose optimization but was controlled by worker's convenience and image quality. Radio-technologiests often set up the exposure dose regardless of patient figure and body part to be examined. Many organizations, such as the International Commission on Radiological Protection, recommend to keep the dose as low as possible. In addition, they strongly recommend to keep the optimal but minimal dosage by proper training programs and constant quality control, including frequent patient dose evaluations and education.

Radiation exposure control during EMCCR campaign at MAPS

International Nuclear Information System (INIS)

Jawahar, S.; Singha Roy, S.

2003-01-01

Enmasse Coolant Channel Replacement (EMCCR) work is second of its kind for Indian PHWR- next to RAPS - 2 campaign- after successful demonstration of ability by NPCIL to carry out such major core component maintenance. The Challenges posed during such campaign are mainly attributed to the radiation field, continuous occupancy, and large quantity of material handling for execution as well as preparing infrastructure, exposure control for large number of workmen. Extensive planning was carried out to address all these issues in order to reduce the downtime of the station keeping the collective dose as low as reasonable achievable (ALARA). This paper highlights the strategy adopted, logistics involved in execution of work and the efforts taken to control radiation exposure during this major campaign. (author)

Systemic uptake and clearance of chloroform by hairless rats following dermal exposure. I. Brief exposure to aqueous solutions.

Science.gov (United States)

Islam, M S; Zhao, L; Zhou, J; Dong, L; McDougal, J N; Flynn, G L

1996-06-01

The systemic uptake of chloroform from dilute aqueous solutions into live hairless rats under conditions simulating dermal environmental exposure was studied. Whole blood was sampled during a 30-min immersion of an animal within water containing a known concentration of chloroform and then for 5.5 h following its removal from the bath. The amount of chloroform systemically absorbed was determined by comparing the AUCs of the blood concentration vs. time plots from dermal exposure to that obtained after i.v. infusion (for a period of 30 min) of an aqueous solution containing a known amount of chloroform (positive control). Although dermal data implied two-compartment disposition characteristics, i.v. infusion data fit best to a three-compartment disposition. Linear pharmacokinetics was observed both by i.v. administration and percutaneous absorption at the dose levels studied. Chloroform was detected in the rat blood as early as 4 min following exposure. Our findings suggest that about 10.2 mg of chloroform was systemically absorbed after dermal exposure of a rat to an aqueous solution of 0.44 mg/ml. This amount is substantially higher than the predictions of mathematical risk-models put forth by some investigators. However, when expressed as the "effective" permeability coefficient (Kpeff), close agreement was noticed between our value and those estimated by others using physiologically based pharmacokinetic (PBPK) models. Also, in terms of Kpeff, reasonable agreement existed between our and another investigator's past estimates of uptake based on depletion of bath level of chloroform and the actual uptake measured in our current experiments. The estimated onset of systemic entry seen here is entirely consistent with our estimate of how long it takes to establish the diffusion gradient across the stratum corneum based on tape stripping.

A population-based case-control study of drinking-water nitrate and congenital anomalies using Geographic Information Systems (GIS) to develop individual-level exposure estimates.

Science.gov (United States)

Holtby, Caitlin E; Guernsey, Judith R; Allen, Alexander C; Vanleeuwen, John A; Allen, Victoria M; Gordon, Robert J

2014-02-05

Animal studies and epidemiological evidence suggest an association between prenatal exposure to drinking water with elevated nitrate (NO3-N) concentrations and incidence of congenital anomalies. This study used Geographic Information Systems (GIS) to derive individual-level prenatal drinking-water nitrate exposure estimates from measured nitrate concentrations from 140 temporally monitored private wells and 6 municipal water supplies. Cases of major congenital anomalies in Kings County, Nova Scotia, Canada, between 1988 and 2006 were selected from province-wide population-based perinatal surveillance databases and matched to controls from the same databases. Unconditional multivariable logistic regression was performed to test for an association between drinking-water nitrate exposure and congenital anomalies after adjusting for clinically relevant risk factors. Employing all nitrate data there was a trend toward increased risk of congenital anomalies for increased nitrate exposure levels though this was not statistically significant. After stratification of the data by conception before or after folic acid supplementation, an increased risk of congenital anomalies for nitrate exposure of 1.5-5.56 mg/L (2.44; 1.05-5.66) and a trend toward increased risk for >5.56 mg/L (2.25; 0.92-5.52) was found. Though the study is likely underpowered, these results suggest that drinking-water nitrate exposure may contribute to increased risk of congenital anomalies at levels below the current Canadian maximum allowable concentration.

Impact of Smoke Exposure on Digital Instrumentation and Control

International Nuclear Information System (INIS)

Tanaka, Tina J.; Nowlen, Steven P.; Korsah, Kofi; Wood, Richard T.; Antonescu, Christina E.

2003-01-01

Smoke can cause interruptions and upsets in active electronics. Because nuclear power plants are replacing analog with digital instrumentation and control systems, qualification guidelines for new systems are being reviewed for severe environments such as smoke and electromagnetic interference. Active digital systems, individual components, and active circuits have been exposed to smoke in a program sponsored by the U.S. Nuclear Regulatory Commission. The circuits and systems were all monitored during the smoke exposure, indicating any immediate effects of the smoke. The results of previous smoke exposure studies have been reported in various publications. The major immediate effect of smoke has been to increase leakage currents and to cause momentary upsets and failures in digital systems. This paper presents new results from conformal coatings, memory chips, and hard drive tests.The best conformal coatings were found to be polyurethane, parylene, and acrylic (when applied by dipping). Conformal coatings can reduce smoke-induced leakage currents and protect against metal loss through corrosion. However conformal coatings are typically flammable, so they do increase material flammability. Some of the low-voltage biased memory chips failed during a combination of high smoke and high humidity. Typically, smoke along with heat and humidity is expected during fire, rather than smoke alone. Thus, due to high sensitivity of digital circuits to heat and humidity, it is hypothesized that the impact of smoke may be secondary.Low-voltage (3.3-V) static random-access memory (SRAMs) were found to be the most vulnerable to smoke. Higher bias voltages decrease the likelihood of failure. Erasable programmable read-only memory (EPROMs) and nonvolatile SRAMs were very smoke tolerant. Failures of the SRAMs occurred when two conditions were present: high density of smoke and high humidity. As the high humidity was present for only part of the test, the failures were intermittent. All

Toxic Exposure Surveillance System (TESS)-based characterization of U.S. non-native venomous snake exposures, 1995-2004.

Science.gov (United States)

Seifert, Steven A; Oakes, Jennifer A; Boyer, Leslie V

2007-01-01

Non-native (exotic) snake exposures in the United States have not been systematically characterized. The Toxic Exposure Surveillance System (TESS) database of the American Association of Poison Control Centers was analyzed to quantify the number and types, demographic associations, clinical presentations, managements and outcomes, and the health resource utilization of non-native snake exposures. From 1995 through 2004, there were 399 non-native exposures in the TESS database. Of these, 350 snakes (87%) were identified by genus and species, comprising at least 77 different varieties. Roughly equal percentages of snakes originated in Asia, Africa and Latin America, with a smaller number from the Middle-East, Australia, and Europe. Nearly half were viperids and a little more than a third were elapids. The vast majority of exposed individuals were adults. However, almost 15% were aged 17 years or less, and almost 7% were children aged 5 years or younger. Eighty-four percent were males. The vast majority of exposures occurred at the victim's own residence. Over 50% were evaluated at a healthcare facility, with 28.7% admitted to an ICU. Overall, 26% of patients were coded as receiving antivenom treatment. Coded outcomes were similar between viperid and elapid envenomations. There were three deaths, two involving viperid snakes and one elapid. Enhancements to the TESS database are required for better precision in and more complete characterization of non-native snake envenomations.

A computer system for occupational radiation exposure information

International Nuclear Information System (INIS)

Hunt, H.W.

1984-01-01

A computerized occupational radiation exposure information system has been developed to maintain records for contractors at the U.S. Department of Energy's (DOE) Hanford Site. The system also allows indexing and retrieval of three million documents from microfilm, thus significantly reducing storage needs and costs. The users are linked by display terminals to the data base permitting them instant access to dosemetry and other radiation exposure information. Personnel dosemeter and bioassay results, radiation training, respirator fittings, skin contaminations and other radiation occurrence records are included in the data base. The system yields immediate analysis of radiological exposures for operating management and health physics personnel, thereby releasing personnel to use their time more effectively

78 FR 68447 - Exposure Draft-Standards for Internal Control in the Federal Government

Science.gov (United States)

2013-11-14

... GOVERNMENT ACCOUNTABILITY OFFICE Exposure Draft--Standards for Internal Control in the Federal... revisions to the Standards for Internal Control in the Federal Government, known as the ``Green Book,'' to... proposed changes contained in the 2013 Exposure Draft update to the Standards for Internal Control in the...

Pesticide exposure and hepatocellular carcinoma risk: A case-control study using a geographic information system (GIS) to link SEER-Medicare and California pesticide data.

Science.gov (United States)

VoPham, Trang; Brooks, Maria M; Yuan, Jian-Min; Talbott, Evelyn O; Ruddell, Darren; Hart, Jaime E; Chang, Chung-Chou H; Weissfeld, Joel L

2015-11-01

Hepatocellular carcinoma (HCC), the most common type of primary liver cancer, is associated with low survival. U.S. studies examining self-reported pesticide exposure in relation to HCC have demonstrated inconclusive results. We aimed to clarify the association between pesticide exposure and HCC by implementing a novel data linkage between Surveillance, Epidemiology, and End Results (SEER)-Medicare and California Pesticide Use Report (PUR) data using a geographic information system (GIS). Controls were frequency-matched to HCC cases diagnosed between 2000 and 2009 in California by year, age, race, sex, and duration of residence in California. Potential confounders were extracted from Medicare claims. From 1974 to 2008, pounds (1 pound represents 0.45 kg) of applied organophosphate, organochlorine, and carbamate pesticides provided in PURs were aggregated to the ZIP Code level using area weighting in a GIS. ZIP Code exposure estimates were linked to subjects using Medicare-provided ZIP Codes to calculate pesticide exposure. Agricultural residents were defined as living in ZIP Codes with a majority area intersecting agricultural land cover according to the 1992, 2001, and 2006 National Land Cover Database (NLCD) rasters. Multivariable conditional logistic regression was used to estimate the association between pesticide exposure and HCC. Among California residents of agriculturally intensive areas, previous annual ZIP Code-level exposure to over 14.53 kg/km(2) of organochlorine pesticides (75(th) percentile among controls) was associated with an increased risk of HCC after adjusting for liver disease and diabetes (adjusted odds ratio [OR] 1.87, 95% confidence interval [CI] 1.17, 2.99; p=0.0085). ZIP Code-level organochlorines were significantly associated with an increased risk of HCC among males (adjusted OR 2.76, 95% CI 1.58, 4.82; p=0.0004), but not associated with HCC among females (adjusted OR 0.83, 95% CI 0.35, 1.93; p=0.6600) (interaction p=0.0075). This is

Drone based measurement system for radiofrequency exposure assessment.

Science.gov (United States)

Joseph, Wout; Aerts, Sam; Vandenbossche, Matthias; Thielens, Arno; Martens, Luc

2016-03-10

For the first time, a method to assess radiofrequency (RF) electromagnetic field (EMF) exposure of the general public in real environments with a true free-space antenna system is presented. Using lightweight electronics and multiple antennas placed on a drone, it is possible to perform exposure measurements. This technique will enable researchers to measure three-dimensional RF-EMF exposure patterns accurately in the future and at locations currently difficult to access. A measurement procedure and appropriate measurement settings have been developed. As an application, outdoor measurements are performed as a function of height up to 60 m for Global System for Mobile Communications (GSM) 900 MHz base station exposure. Bioelectromagnetics. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Radiation Exposure Monitoring and Information Transmittal (REMIT) system

International Nuclear Information System (INIS)

Cale, R.; Clark, T.; Dixson, R.; Hagemeyer, D.

1993-06-01

The Radiation Exposure Monitoring and Information Transmittal (REMIT) system is designed to assist US Nuclear Regulatory Commission (NRC)licensees in meeting the reporting requirements of the revised 10 CFR 20 and in agreement with the guidance contained in R.G. 8.7, Rev. 1, ''Instructions for Recording and Reporting Occupational Exposure Data.'' REMIT is a personal computer (PC) based menu driven system that facilitates the manipulation of data base files to record and report radiation exposure information. REMIT is designed to be user-friendly and contains the full text of R. G. 8.7, Rev. 1, on-line as well as context-sensitive help throughout the program. The user can enter data directly from NRC Forms 4 or 5, REMIT allows the user to view the individual's exposure in relation to regulatory or administrative limits and alerts the user to exposures in excess of these limits. The system also provides for the calculation and summation of dose from intakes and the determination of the dose to the maximally exposed extremity for the monitoring year. REMIT can produce NRC Forms 4 and 5 in paper and electronic format and can import/export data from ASCII and data base files

Occupational exposures and non-Hodgkin's lymphoma: Canadian case-control study

Directory of Open Access Journals (Sweden)

Spinelli John J

2008-08-01

Full Text Available Abstract Background The objective was to study the association between Non-Hodgkin's Lymphoma (NHL and occupational exposures related to long held occupations among males in six provinces of Canada. Methods A population based case-control study was conducted from 1991 to 1994. Males with newly diagnosed NHL (ICD-10 were stratified by province of residence and age group. A total of 513 incident cases and 1506 population based controls were included in the analysis. Conditional logistic regression was conducted to fit statistical models. Results Based on conditional logistic regression modeling, the following factors independently increased the risk of NHL: farmer and machinist as long held occupations; constant exposure to diesel exhaust fumes; constant exposure to ionizing radiation (radium; and personal history of another cancer. Men who had worked for 20 years or more as farmer and machinist were the most likely to develop NHL. Conclusion An increased risk of developing NHL is associated with the following: long held occupations of faer and machinist; exposure to diesel fumes; and exposure to ionizing radiation (radium. The risk of NHL increased with the duration of employment as a farmer or machinist.

New Radiofrequency Exposure System with Real Telecommunication Signals

Directory of Open Access Journals (Sweden)

Jakub Misek

2018-01-01

Full Text Available In recent years, there has been an increase in the number of studies on biological effects of Electromagnetic (EM fields emitted from Base Transceiver Stations (BTSs. The biological effects of generated and real telecommunication signals produced by different types of exposure systems are discussed. However, the proper exposure methods for such experiments are very limited. We successfully developed a simple and cost-effective exposure unit with real GSM/DCS/UMTS signal from BTS containing proper modulations or intermittence (continuous, interrupted. Signal processing and conditioning unit is based on a Radiofrequency (RF repeater. The downlink signal is filtered by integrated high selectivity passband filters and amplified to a required level. The main part of exposure unit is a Faraday cage with the specimen (exposure area measuring 150 x 250 mm with E-field percent deviation less than 18%. This exposure system can be helpful in experiments with living organisms in in vivo studies and in vitro studies with normal or pathological cells and other micro scale structures being exposed to RF EM fields from BTS.

Repeated cocaine exposure facilitates the expression of incentive motivation and induces habitual control in rats.

Directory of Open Access Journals (Sweden)

Kimberly H LeBlanc

Full Text Available There is growing evidence that mere exposure to drugs can induce long-term alterations in the neural systems that mediate reward processing, motivation, and behavioral control, potentially causing the pathological pursuit of drugs that characterizes the addicted state. The incentive sensitization theory proposes that drug exposure potentiates the influence of reward-paired cues on behavior. It has also been suggested that drug exposure biases action selection towards the automatic execution of habits and away from more deliberate goal-directed control. The current study investigated whether rats given repeated exposure to peripherally administered cocaine would show alterations in incentive motivation (assayed using the Pavlovian-to-instrumental transfer (PIT paradigm or habit formation (assayed using sensitivity to reward devaluation. After instrumental and Pavlovian training for food pellet rewards, rats were given 6 daily injections of cocaine (15 mg/kg, IP or saline, followed by a 10-d period of rest. Consistent with the incentive sensitization theory, cocaine-treated rats showed stronger cue-evoked lever pressing than saline-treated rats during the PIT test. The same rats were then trained on a new instrumental action with a new food pellet reward before undergoing a reward devaluation testing. Although saline-treated rats exhibited sensitivity to reward devaluation, indicative of goal-directed performance, cocaine-treated rats were insensitive to this treatment, suggesting a reliance on habitual processes. These findings, when taken together, indicate that repeated exposure to cocaine can cause broad alterations in behavioral control, spanning both motivational and action selection processes, and could therefore help explain aberrations of decision-making that underlie drug addiction.

Repeated cocaine exposure facilitates the expression of incentive motivation and induces habitual control in rats.

Science.gov (United States)

LeBlanc, Kimberly H; Maidment, Nigel T; Ostlund, Sean B

2013-01-01

There is growing evidence that mere exposure to drugs can induce long-term alterations in the neural systems that mediate reward processing, motivation, and behavioral control, potentially causing the pathological pursuit of drugs that characterizes the addicted state. The incentive sensitization theory proposes that drug exposure potentiates the influence of reward-paired cues on behavior. It has also been suggested that drug exposure biases action selection towards the automatic execution of habits and away from more deliberate goal-directed control. The current study investigated whether rats given repeated exposure to peripherally administered cocaine would show alterations in incentive motivation (assayed using the Pavlovian-to-instrumental transfer (PIT) paradigm) or habit formation (assayed using sensitivity to reward devaluation). After instrumental and Pavlovian training for food pellet rewards, rats were given 6 daily injections of cocaine (15 mg/kg, IP) or saline, followed by a 10-d period of rest. Consistent with the incentive sensitization theory, cocaine-treated rats showed stronger cue-evoked lever pressing than saline-treated rats during the PIT test. The same rats were then trained on a new instrumental action with a new food pellet reward before undergoing a reward devaluation testing. Although saline-treated rats exhibited sensitivity to reward devaluation, indicative of goal-directed performance, cocaine-treated rats were insensitive to this treatment, suggesting a reliance on habitual processes. These findings, when taken together, indicate that repeated exposure to cocaine can cause broad alterations in behavioral control, spanning both motivational and action selection processes, and could therefore help explain aberrations of decision-making that underlie drug addiction.

Optimizing the use of on-street car parking system as a passive control of air pollution exposure in street canyons by large eddy simulation

Science.gov (United States)

Gallagher, J.; Gill, L. W.; McNabola, A.

2011-03-01

An investigation was carried out to establish the effectiveness of parked cars in urban street canyons as passive controls on pedestrian pollutant exposure. A numerical model of a generic street canyon was developed using a large eddy simulation (LES) model to compare personal exposure on the footpath with and without the presence of parked cars. Three configurations of car parking systems were investigated (parallel, perpendicular and 45° parking) in addition to the influence of wind speed, wind direction and car parking occupancy. A tracer gas (CO 2) was used as a representative pollutant from vehicular sources within the street canyon models. The results indicated that parked cars may act as a temporary baffle plate between traffic emissions and pedestrians on the footpath. Reductions in exposure of up to 35% and 49% were attained on the leeward and windward footpaths in perpendicular wind conditions, with parallel winds allowing up to 33% pollutant reduction on both footpaths for parallel parking. The perpendicular and 45° car parking configurations investigated proved less successful as passive controls on air pollution exposure and an increase in pollutant concentration occurred in some models. An investigation of parking space occupancy rates was carried out for parallel parked cars. The fraction of parked cars influenced the level of reduction of pollutants on the footpaths with steady reductions in perpendicular winds, yet reductions were only evident for occupancy rates greater than approximately 45% in parallel wind conditions. One negative impact associated with the parked cars study was the increase of pollutant levels on the roadway as the parked cars acted as a baffle wall, which trapped pollutants in the road. The paper underlines the potential of on-street car parking for reducing the personal exposure of pollutants by pedestrians and the optimum parking layout to achieve maximum health protection.

An evaluation of retrofit engineering control interventions to reduce perchloroethylene exposures in commercial dry-cleaning shops.

Science.gov (United States)

Earnest, G Scott; Ewers, Lynda M; Ruder, Avima M; Petersen, Martin R; Kovein, Ronald J

2002-02-01

Real-time monitoring was used to evaluate the ability of engineering control devices retrofitted on two existing dry-cleaning machines to reduce worker exposures to perchloroethylene. In one dry-cleaning shop, a refrigerated condenser was installed on a machine that had a water-cooled condenser to reduce the air temperature, improve vapor recovery, and lower exposures. In a second shop, a carbon adsorber was retrofitted on a machine to adsorb residual perchloroethylene not collected by the existing refrigerated condenser to improve vapor recovery and reduce exposures. Both controls were successful at reducing the perchloroethylene exposures of the dry-cleaning machine operator. Real-time monitoring was performed to evaluate how the engineering controls affected exposures during loading and unloading the dry-cleaning machine, a task generally considered to account for the highest exposures. The real-time monitoring showed that dramatic reductions occurred in exposures during loading and unloading of the dry-cleaning machine due to the engineering controls. Peak operator exposures during loading and unloading were reduced by 60 percent in the shop that had a refrigerated condenser installed on the dry-cleaning machine and 92 percent in the shop that had a carbon adsorber installed. Although loading and unloading exposures were dramatically reduced, drops in full-shift time-weighted average (TWA) exposures were less dramatic. TWA exposures to perchloroethylene, as measured by conventional air sampling, showed smaller reductions in operator exposures of 28 percent or less. Differences between exposure results from real-time and conventional air sampling very likely resulted from other uncontrolled sources of exposure, differences in shop general ventilation before and after the control was installed, relatively small sample sizes, and experimental variability inherent in field research. Although there were some difficulties and complications with installation and

Gain and offset calibration reduces variation in exposure-dependent SNR among systems with identical digital flat-panel detectors.

Science.gov (United States)

Willis, Charles E; Vinogradskiy, Yevgeniy Y; Lofton, Brad K; White, R Allen

2011-07-01

The conditions under which vendor performance criteria for digital radiography systems are obtained do not adequately simulate the conditions of actual clinical imaging with respect to radiographic technique factors, scatter production, and scatter control. Therefore, the relationship between performance under ideal conditions and performance in clinical practice remains unclear. Using data from a large complement of systems in clinical use, the authors sought to develop a method to establish expected performance criteria for digital flat-panel radiography systems with respect to signal-to-noise ratio (SNR) versus detector exposure under clinical conditions for thoracic imaging. The authors made radiographic exposures of a patient-equivalent chest phantom at 125 kVp and 180 cm source-to-image distance. The mAs value was modified to produce exposures above and below the mAs delivered by automatic exposure control. Exposures measured free-in-air were corrected to the imaging plane by the inverse square law, by the attenuation factor of the phantom, and by the Bucky factor of the grid for the phantom, geometry, and kilovolt peak. SNR was evaluated as the ratio of the mean to the standard deviation (SD) of a region of interest automatically selected in the center of each unprocessed image. Data were acquired from 18 systems, 14 of which were tested both before and after gain and offset calibration. SNR as a function of detector exposure was interpolated using a double logarithmic function to stratify the data into groups of 0.2, 0.5, 1.0, 2.0, and 5.0 mR exposure (1.8, 4.5, 9.0, 18, and 45 microGy air KERMA) to the detector. The mean SNR at each exposure interval after calibration exhibited linear dependence on the mean SNR before calibration (r2=0.9999). The dependence was greater than unity (m = 1.101 +/- 0.006), and the difference from unity was statistically significant (p grid replacement. The nonconformant behavior of the other system was corrected by replacing

A Population-Based Case-Control Study of Drinking-Water Nitrate and Congenital Anomalies Using Geographic Information Systems (GIS) to Develop Individual-Level Exposure Estimates

Science.gov (United States)

Holtby, Caitlin E.; Guernsey, Judith R.; Allen, Alexander C.; VanLeeuwen, John A.; Allen, Victoria M.; Gordon, Robert J.

2014-01-01

Animal studies and epidemiological evidence suggest an association between prenatal exposure to drinking water with elevated nitrate (NO3-N) concentrations and incidence of congenital anomalies. This study used Geographic Information Systems (GIS) to derive individual-level prenatal drinking-water nitrate exposure estimates from measured nitrate concentrations from 140 temporally monitored private wells and 6 municipal water supplies. Cases of major congenital anomalies in Kings County, Nova Scotia, Canada, between 1988 and 2006 were selected from province-wide population-based perinatal surveillance databases and matched to controls from the same databases. Unconditional multivariable logistic regression was performed to test for an association between drinking-water nitrate exposure and congenital anomalies after adjusting for clinically relevant risk factors. Employing all nitrate data there was a trend toward increased risk of congenital anomalies for increased nitrate exposure levels though this was not statistically significant. After stratification of the data by conception before or after folic acid supplementation, an increased risk of congenital anomalies for nitrate exposure of 1.5–5.56 mg/L (2.44; 1.05–5.66) and a trend toward increased risk for >5.56 mg/L (2.25; 0.92–5.52) was found. Though the study is likely underpowered, these results suggest that drinking-water nitrate exposure may contribute to increased risk of congenital anomalies at levels below the current Canadian maximum allowable concentration. PMID:24503976

Control in personnel exposure at HIRUP facility during the period 2006-2010

International Nuclear Information System (INIS)

Ojha, Shashikala; Suman, Santosh Kumar; Murali, S.

2012-01-01

HIRUP facility is designed to handle MCi of 60 Co, fabrication of sealed source, is carried out in hot cell. The design safety features allow the handling of sealed sources and other gamma emitters under suitable containment systems. The NP Unit of the facility provides personnel monitoring programmes viz., TLD/DRD monitoring for the radiation workers. 60 Co and other gamma emitters pose mainly external hazard during the handling of sealed source in hot cell. TLD is processed to assess the external exposure of personnel. Air activity and gross bg contamination at the work place is periodically monitored and reported. The TLD users of HIRUP are periodically referred for internal monitoring - whole body counting and bio-assay to estimate internal exposure. There is no reported internal exposure so far. Personnel from IAD and BRIT facility are provided with personnel monitoring coverage by HP Unit; the TLD is issued with respective institution no. as - 0283, 4288. Each person gets identified by individual TLD number, renewed TLD issue on quarterly service period. Based on job requirement such as handling of high activity, additional Wrist TLDs are provided. The used TLD of IAD and BRIT are sent for processing. The dose report obtained, enlists personnel exposure details. HP Unit does the report making to the concerned agencies enlisting the operational status, total occupational exposure of the facility (person mSv), average exposure (mSv) and few other details. Details of exposure for 2006 - 2010 (non-zero exposure cases), indicate that for IAD collective exposure got reduced by 78.5 %, average exposure got reduced by 62.6 %; for BRIT collective exposure got reduced by 58.2 %, average exposure got reduced by 46.8 %, at HIRUP facility. There is a decreasing trend in personnel exposure over the period 2006-2010, is due to HP safety protocol, on job HP surveillance and related safety measures. The personnel exposure is controlled as per ALARA, decreasing trend in the

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

Strategies for Controlling Item Exposure in Computerized Adaptive Testing with the Generalized Partial Credit Model

Science.gov (United States)

Davis, Laurie Laughlin

2004-01-01

Choosing a strategy for controlling item exposure has become an integral part of test development for computerized adaptive testing (CAT). This study investigated the performance of six procedures for controlling item exposure in a series of simulated CATs under the generalized partial credit model. In addition to a no-exposure control baseline…

Effects of chronic exposure to electromagnetic waves on the auditory system.

Science.gov (United States)

Özgür, Abdulkadir; Tümkaya, Levent; Terzi, Suat; Kalkan, Yıldıray; Erdivanlı, Özlem Çelebi; Dursun, Engin

2015-08-01

The results support that chronic electromagnetic field exposure may cause damage by leading to neuronal degeneration of the auditory system. Numerous researches have been done about the risks of exposure to the electromagnetic fields that occur during the use of these devices, especially the effects on hearing. The aim of this study is to evaluate the effects of the electromagnetic waves emitted by the mobile phones through the electrophysiological and histological methods. Twelve adult Wistar albino rats were included in the study. The rats were divided into two groups of six rats. The study group was exposed to the electromagnetic waves over a period of 30 days. The control group was not given any exposure to the electromagnetic fields. After the completion of the electromagnetic wave application, the auditory brainstem responses of both groups were recorded under anesthesia. The degeneration of cochlear nuclei was graded by two different histologists, both of whom were blinded to group information. The histopathologic and immunohistochemical analysis showed neuronal degeneration signs, such as increased vacuolization in the cochlear nucleus, pyknotic cell appearance, and edema in the group exposed to the electromagnetic fields compared to the control group. The average latency of wave in the ABR was similar in both groups (p > 0.05).

Proposed alternatives for a DOE-wide occupational radiation exposure information system

International Nuclear Information System (INIS)

Murphy, B.L.; Murphy, D.W.; Fix, J.J.; Selby, J.M.; Vallario, E.J.

1984-02-01

The Radiation Exposure Information Reporting System (REIRS) was initiated by the Atomic Energy Commission (AEC) in 1968. While the system has provided a general overview of radiation exposures associated with AEC/ERDA/DOE operations and has satisfied the original intent for a central information system, the need for more detailed information has become evident. The alternatives addressed for a radiation exposure information system were no change in current system, clarification of DOE Order for current system, increased summary information from sites, centralized annual individual dose (exposure) system, and annual dose summary and locator files. A majority of the DOE Ad Hoc Committee has concurred to recommend the annual dose summary and locator files (ADSLF). The acceptance of the ADSLF alternative as the DOE-wide radiation exposure system would give DOE added capability and flexibility in responding to requests for information and would reduce the impact on the sites of special survey requests

Exposure to Inhalable Dust, Endotoxin, and Total Volatile Organic Carbons on Dairy Farms Using Manual and Automated Feeding Systems

DEFF Research Database (Denmark)

Basinas, Ioannis; Cronin, Garvin; Hogan, Victoria

2017-01-01

Introduction: Agricultural workers tend to have high exposures to organic dusts which may induce or exacerbate respiratory disorders. Studies investigating the effect of work tasks and farm characteristics on organic dust exposures among farm workers suggest that handling of animal feed is an imp...... feeding. Until effective permanent engineering controls are established farm workers should be encouraged to wear respiratory protective equipment during these tasks....... of exposure to these agents depend on the applied feeding system in the farms. Methods: Thirty-eight personal exposure measurements were collected from farmers across seven dairy farms. The farms used manual, loft, or semi-automated feeding systems. Information on worker tasks and farm characteristics...

Controlling exposure to DPM : diesel particulate filters vs. biodiesel

International Nuclear Information System (INIS)

Bugarski, A.D.; Shi, X.C.

2009-01-01

In order to comply with Mine Safety and Health Administration regulations, mining companies are required to reduce miners exposures to diesel particulate matter (DPM) to 160 μg/m 3 of total carbon. Diesel particulate filter (DPF) systems, disposable filter elements (DFEs), and diesel oxidation catalysts (DOCs) are among the most effective strategies and technologies for curtailing DPM at its source. Substituting diesel fuel with biodiesel blends is also considered to be a plausible solution by many underground mine operators. Studies were conducted at the National Institute for Occupational Safety and Health Diesel Laboratory at Lake Lynn Experimental Mine to evaluate various control technologies and strategies available to the underground mining industry to reduce exposure to DPM. The physical, chemical and toxicological properties of diesel aerosols (DPM) emitted by engines in an underground mine were also evaluated. The DPF and DFE systems were found to be highly effective in reducing total particulate and elemental carbon mass concentrations, total aerosol surface concentrations and, in most cases, concentrations of diesel aerosols in occupational settings such as underground mines. Soy methyl ester (SME) biodiesel fuels had the potential to reduce the mine air concentrations of total DPM, although the rate of reduction varied depending on engine operating conditions. The disadvantage of using biodiesel fuels was an increase in the fraction of particle-bound volatile organics and concentration of aerosols for light-load engine operating conditions.

Information System on Occupational Exposure: Future Developments

International Nuclear Information System (INIS)

Jean-Yves Gagnon; Waturu Mizumachi; Brian Ahier; Ted Lazo; Khammar Mrabit

2006-01-01

In response to pressures from deregulation and from ageing of the global nuclear power plant fleet, radiation protection personnel have found that occupational exposures are best managed through proper job planning, implementation and review to ensure that exposures are 'as low as reasonably achievable'(ALARA). A prerequisite for applying the principle of optimisation to occupational radiation protection is the timely exchange of data and information on dose reduction methods. To facilitate this global approach to work management, the OECD Nuclear Energy Agency (Nea) launched the Information System on Occupational Exposure (I.S.O.E.) in 1992. The objective of I.S.O.E. is to provide a forum for radiation protection experts from both utilities and national regulatory authorities to discuss, promote and coordinate international cooperative undertakings for the radiological protection of workers at nuclear power plants.The I.S.O.E. programme offers a variety of products in the occupational exposure area, such as: the world largest database on occupational exposure from nuclear power plants, a yearly analysis of dose trends and an overview of current developments, through I.S.O.E. Annual Reports, detailed studies, analyses, and information on current issues in operational radiation protection, through I.S.O.E. Information Sheets, a system for rapid communication of radiation protection-related information, such as effective dose reduction approaches and implementation of work management principles. A forum for discussing occupational exposure management issues through I.S.O.E. workshops, symposia and newsletters. (N.C.)

Automatic exposure system for radioactive source at teaching laboratory

International Nuclear Information System (INIS)

Seren, Maria Emilia G.; Gaal, Vladmir; Morais, Sergio Luiz de; Rodrigues, Varlei

2013-01-01

The development of Compton Scattering experiment, studied by undergraduate students of the Medical Physics course at the Universidade Estadual de Campinas (UNICAMP), takes place in the Medical Physics Teaching Laboratory, belonging to the Gleb Wataghin Physics Institute (IFGW/UNICAMP). The experiment consists of a fixed 137 Cs radioactive source, with current activity of 610.5 MBq and a scintillation detector that turns around the center of the system whose function is to detect the scattered photons spectrum by a scatter object (target). The 137 Cs source is stored in a lead shield with a collimating window for the gamma radiation emitted with energy of 0.662 MeV. This source is exposed only when an attenuation barrier protecting the collimating window is opened. The process of opening and closing the attenuation barrier may deliver a radiation dose to users when done manually. Considering the stochastic harmful effects of ionizing radiation, the goal of this project was to develop an automatic exposure system of the radioactive source, in order to reduce the radiation dose received during the Compton Scattering experiment. The developed system is micro controlled and performs standard operating routines, responding to emergencies. Furthermore, an electromagnetic lock enables quick closing of the barrier by gravity, in case of interruption of the electrical current circuit. Besides reducing the total dose to lab users, the system adds more security to the routine, since it limits the access to the radioactive source and prevents accidental exposure. (author)

Uncertainties of exposure-related quantities in mammographic x-ray unit quality control

International Nuclear Information System (INIS)

Gregory, Kent J.; Pattison, John E.; Bibbo, Giovanni

2006-01-01

Breast screening programs operate in many countries with mammographic x-ray units subject to stringent quality control tests. These tests include the evaluation of quantities based on exposure measurements, such as half value layer, automatic exposure control reproducibility, average glandular dose, and radiation output rate. There are numerous error sources that contribute to the uncertainty of these exposure-related quantities, some of which are unique to the low energy x-ray spectrum produced by mammographic x-ray units. For each of these exposure-related quantities, the applicable error sources and their magnitudes vary, depending on the test equipment used to make the measurement, and whether or not relevant corrections have been applied. This study has identified and quantified a range of error sources that may be used to estimate the combined uncertainty of these exposure-related quantities, given the test equipment used and corrections applied. The uncertainty analysis uses methods described by the International Standards Organization's Guide to the Expression of Uncertainty in Measurement. Examples of how these error sources combine to give the uncertainty of the exposure-related quantities are presented. Using the best test equipment evaluated in this study, uncertainties of the four exposure-related quantities at the 95% confidence interval were found to be ±1.6% (half value layer), ±0.0008 (automatic exposure control reproducibility), ±2.3% (average glandular dose), and ±2.1% (radiation output rate). In some cases, using less precise test equipment or failing to apply corrections, resulted in uncertainties more than double in magnitude

Prenatal methylmercury exposure hampers glutathione antioxidant system ontogenesis and causes long-lasting oxidative stress in the mouse brain

International Nuclear Information System (INIS)

Stringari, James; Nunes, Adriana K.C.; Franco, Jeferson L.; Bohrer, Denise; Garcia, Solange C.; Dafre, Alcir L.; Milatovic, Dejan; Souza, Diogo O.; Rocha, Joao B.T.; Aschner, Michael; Farina, Marcelo

2008-01-01

During the perinatal period, the central nervous system (CNS) is extremely sensitive to metals, including methylmercury (MeHg). Although the mechanism(s) associated with MeHg-induced developmental neurotoxicity remains obscure, several studies point to the glutathione (GSH) antioxidant system as an important molecular target for this toxicant. To extend our recent findings of MeHg-induced GSH dyshomeostasis, the present study was designed to assess the developmental profile of the GSH antioxidant system in the mouse brain during the early postnatal period after in utero exposure to MeHg. Pregnant mice were exposed to different doses of MeHg (1, 3 and 10 mg/l, diluted in drinking water, ad libitum) during the gestational period. After delivery, pups were killed at different time points - postnatal days (PND) 1, 11 and 21 - and the whole brain was used for determining biochemical parameters related to the antioxidant GSH system, as well as mercury content and the levels of F 2 -isoprostane. In control animals, cerebral GSH levels significantly increased over time during the early postnatal period; gestational exposure to MeHg caused a dose-dependent inhibition of this developmental event. Cerebral glutathione peroxidase (GPx) and glutathione reductase (GR) activities significantly increased over time during the early postnatal period in control animals; gestational MeHg exposure induced a dose-dependent inhibitory effect on both developmental phenomena. These adverse effects of prenatal MeHg exposure were corroborated by marked increases in cerebral F 2 -isoprostanes levels at all time points. Significant negative correlations were found between F 2 -isoprostanes and GSH, as well as between F 2 -isoprostanes and GPx activity, suggesting that MeHg-induced disruption of the GSH system maturation is related to MeHg-induced increased lipid peroxidation in the pup brain. In utero MeHg exposure also caused a dose-dependent increase in the cerebral levels of mercury at

An experimental system for the study of ultrasound exposure of isolated blood vessels

International Nuclear Information System (INIS)

Tokarczyk, Anna; Rivens, Ian; Symonds-Tayler, Richard; Ter Haar, Gail; Van Bavel, E

2013-01-01

An experimental system designed for the study of the effects of diagnostic or therapeutic ultrasound exposure on isolated blood vessels in the presence or absence of intraluminal contrast agent is described. The system comprised several components. A microscope was used to monitor vessel size (and thus vessel functionality), and potential leakage of intraluminal 70 kDa FITC-dextran fluorescence marker. A vessel chamber allowed the mounting of an isolated vessel whilst maintaining its viability, with pressure regulation for the control of intraluminal pressure and induction of flow for the infusion of contrast microbubbles. A fibre-optic hydrophone sensor mounted on the vessel chamber using a micromanipulator allowed pre-exposure targeting of the vessel to within 150 µm, and monitoring of acoustic cavitation emissions during exposures. Acoustic cavitation was also detected using changes in the ultrasound drive voltage and by detection of audible emissions using a submerged microphone. The suitability of this system for studying effects in the isolated vessel model has been demonstrated using a pilot study of 6 sham exposed and 18 high intensity focused ultrasound exposed vessels, with or without intraluminal contrast agent (SonoVue) within the vessels. (paper)

Development of a dose-controlled multiculture cell exposure chamber for efficient delivery of airborne and engineered nanoparticles

International Nuclear Information System (INIS)

Asimakopoulou, Akrivi; Daskalos, Emmanouil; Papaioannou, Eleni; Konstandopoulos, Athanasios G; Lewinski, Nastassja; Riediker, Michael

2013-01-01

In order to study the various health influencing parameters related to engineered nanoparticles as well as to soot emitted by Diesel engines, there is an urgent need for appropriate sampling devices and methods for cell exposure studies that simulate the respiratory system and facilitate associated biological and toxicological tests. The objective of the present work was the further advancement of a Multiculture Exposure Chamber (MEC) into a dose-controlled system for efficient delivery of nanoparticles to cells. It was validated with various types of nanoparticles (Diesel engine soot aggregates, engineered nanoparticles for various applications) and with state-of-the-art nanoparticle measurement instrumentation to assess the local deposition of nanoparticles on the cell cultures. The dose of nanoparticles to which cell cultures are being exposed was evaluated in the normal operation of the in vitro cell culture exposure chamber based on measurements of the size specific nanoparticle collection efficiency of a cell free device. The average efficiency in delivering nanoparticles in the MEC was approximately 82%. The nanoparticle deposition was demonstrated by Transmission Electron Microscopy (TEM). Analysis and design of the MEC employs Computational Fluid Dynamics (CFD) and true to geometry representations of nanoparticles with the aim to assess the uniformity of nanoparticle deposition among the culture wells. Final testing of the dose-controlled cell exposure system was performed by exposing A549 lung cell cultures to fluorescently labeled nanoparticles. Delivery of aerosolized nanoparticles was demonstrated by visualization of the nanoparticle fluorescence in the cell cultures following exposure. Also monitored was the potential of the aerosolized nanoparticles to generate reactive oxygen species (ROS) (e.g. free radicals and peroxides generation), thus expressing the oxidative stress of the cells which can cause extensive cellular damage or damage on DNA.

Development of a dose-controlled multiculture cell exposure chamber for efficient delivery of airborne and engineered nanoparticles

Science.gov (United States)

Asimakopoulou, Akrivi; Daskalos, Emmanouil; Lewinski, Nastassja; Riediker, Michael; Papaioannou, Eleni; Konstandopoulos, Athanasios G.

2013-04-01

In order to study the various health influencing parameters related to engineered nanoparticles as well as to soot emitted by Diesel engines, there is an urgent need for appropriate sampling devices and methods for cell exposure studies that simulate the respiratory system and facilitate associated biological and toxicological tests. The objective of the present work was the further advancement of a Multiculture Exposure Chamber (MEC) into a dose-controlled system for efficient delivery of nanoparticles to cells. It was validated with various types of nanoparticles (Diesel engine soot aggregates, engineered nanoparticles for various applications) and with state-of-the-art nanoparticle measurement instrumentation to assess the local deposition of nanoparticles on the cell cultures. The dose of nanoparticles to which cell cultures are being exposed was evaluated in the normal operation of the in vitro cell culture exposure chamber based on measurements of the size specific nanoparticle collection efficiency of a cell free device. The average efficiency in delivering nanoparticles in the MEC was approximately 82%. The nanoparticle deposition was demonstrated by Transmission Electron Microscopy (TEM). Analysis and design of the MEC employs Computational Fluid Dynamics (CFD) and true to geometry representations of nanoparticles with the aim to assess the uniformity of nanoparticle deposition among the culture wells. Final testing of the dose-controlled cell exposure system was performed by exposing A549 lung cell cultures to fluorescently labeled nanoparticles. Delivery of aerosolized nanoparticles was demonstrated by visualization of the nanoparticle fluorescence in the cell cultures following exposure. Also monitored was the potential of the aerosolized nanoparticles to generate reactive oxygen species (ROS) (e.g. free radicals and peroxides generation), thus expressing the oxidative stress of the cells which can cause extensive cellular damage or damage on DNA.

An investigation of automatic exposure control calibration for chest imaging with a computed radiography system

International Nuclear Information System (INIS)

Moore, C S; Wood, T J; Beavis, A W; Saunderson, J R; Avery, G; Balcam, S; Needler, L

2014-01-01

The purpose of this study was to examine the use of three physical image quality metrics in the calibration of an automatic exposure control (AEC) device for chest radiography with a computed radiography (CR) imaging system. The metrics assessed were signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and mean effective noise equivalent quanta (eNEQ m ), all measured using a uniform chest phantom. Subsequent calibration curves were derived to ensure each metric was held constant across the tube voltage range. Each curve was assessed for its clinical appropriateness by generating computer simulated chest images with correct detector air kermas for each tube voltage, and grading these against reference images which were reconstructed at detector air kermas correct for the constant detector dose indicator (DDI) curve currently programmed into the AEC device. All simulated chest images contained clinically realistic projected anatomy and anatomical noise and were scored by experienced image evaluators. Constant DDI and CNR curves do not appear to provide optimized performance across the diagnostic energy range. Conversely, constant eNEQ m  and SNR do appear to provide optimized performance, with the latter being the preferred calibration metric given as it is easier to measure in practice. Medical physicists may use the SNR image quality metric described here when setting up and optimizing AEC devices for chest radiography CR systems with a degree of confidence that resulting clinical image quality will be adequate for the required clinical task. However, this must be done with close cooperation of expert image evaluators, to ensure appropriate levels of detector air kerma. (paper)

An investigation of automatic exposure control calibration for chest imaging with a computed radiography system.

Science.gov (United States)

Moore, C S; Wood, T J; Avery, G; Balcam, S; Needler, L; Beavis, A W; Saunderson, J R

2014-05-07

The purpose of this study was to examine the use of three physical image quality metrics in the calibration of an automatic exposure control (AEC) device for chest radiography with a computed radiography (CR) imaging system. The metrics assessed were signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and mean effective noise equivalent quanta (eNEQm), all measured using a uniform chest phantom. Subsequent calibration curves were derived to ensure each metric was held constant across the tube voltage range. Each curve was assessed for its clinical appropriateness by generating computer simulated chest images with correct detector air kermas for each tube voltage, and grading these against reference images which were reconstructed at detector air kermas correct for the constant detector dose indicator (DDI) curve currently programmed into the AEC device. All simulated chest images contained clinically realistic projected anatomy and anatomical noise and were scored by experienced image evaluators. Constant DDI and CNR curves do not appear to provide optimized performance across the diagnostic energy range. Conversely, constant eNEQm and SNR do appear to provide optimized performance, with the latter being the preferred calibration metric given as it is easier to measure in practice. Medical physicists may use the SNR image quality metric described here when setting up and optimizing AEC devices for chest radiography CR systems with a degree of confidence that resulting clinical image quality will be adequate for the required clinical task. However, this must be done with close cooperation of expert image evaluators, to ensure appropriate levels of detector air kerma.

The mere exposure effect for consumer products as a consequence of existing familiarity and controlled exposure.

Science.gov (United States)

Hekkert, Paul; Thurgood, Clementine; Whitfield, T W Allan

2013-10-01

The finding that repeated exposure to a stimulus enhances attitudes directed towards it is a well-established phenomenon. Despite this, the effects of exposure to products are difficult to determine given that they could have previously been exposed to participants any number of times. Furthermore, factors other than simple repeated exposure can influence affective evaluations for stimuli that are meaningful. In our first study, we examined the influence of existing familiarity with common objects and showed that the attractiveness of shapes representing common objects increases with their rated commonness. In our second study, we eliminated the effects of prior exposure by creating fictitious yet plausible products; thus, exposure frequency was under complete experimental control. We also manipulated the attention to be drawn to the products' designs by placing them in contexts where their visual appearance was stressed to be important versus contexts in which it was indicated that little attention had been paid to their design. Following mere exposure, attractiveness ratings increased linearly with exposure frequency, with the slope of the function being steeper for stimuli presented in an inconspicuous context-indicating that individuals engage in more deliberate processing of the stimuli when attention is drawn to their visual appearance. © 2013 Elsevier B.V. All rights reserved.

Engineering control technologies to reduce occupational silica exposures in masonry cutting and tuckpointing.

Science.gov (United States)

Meeker, John D; Cooper, Michael R; Lefkowitz, Daniel; Susi, Pam

2009-01-01

A number of tasks in construction generate worker overexposures to respirable crystalline silica dust, which is a significant contributor to occupational mortality and morbidity. This study evaluated the performance of commercially available engineering controls used in dusty construction tasks commonly performed by bricklayers. Local exhaust ventilation (LEV) controls for a portable abrasive cutter and for tuckpointing grinders were examined at a bricklayers' training center, as were two stationary wet saws. Personal breathing zone air samples were collected with and without the use of LEV or water suppression during simulated concrete block cutting, brick cutting, and tuckpointing. Compared with the use of no exposure control during block and brick cutting, the portable LEV unit significantly reduced mean respirable quartz exposures by 96% for block cutting and 91% for brick cutting (p controls (p control and no-control scenarios. These reductions with commercially available off-the-shelf tools demonstrate the effectiveness of engineering control interventions to reduce crystalline silica exposures in construction. Strategies to further improve control performance and approaches for increasing control interventions in construction are needed.

Control of occupational exposure in nuclear facilities for terrestrial support to marine vessels

International Nuclear Information System (INIS)

Lara, E.G.; Pinheiro, A.R.M.; Borsoi, S.S.; Silva, T.P.; Baroni, D.B.; Santos, F.C.

2017-01-01

This study addresses some basic requirements for exposure control of occupational exposure during the design phase of ground-based nuclear facilities for marine vessels. US regulatory guidelines, CNEN standards and experiences acquired in conventional nuclear installations were used. The installation design should consider the provision of mobile devices for monitoring and decontamination. Finally, it is observed that the establishment of additional exposure control criteria can directly impact the civil, architectural and electromechanical projects of the facility, from the conceptual phase

Reducing methods of patients exposed dose using auto exposure control system in digital radiography

Energy Technology Data Exchange (ETDEWEB)

Shin, Seong Gyu [Dept. of Diagnostic Radiology, Dong A University Medical Center, Busan (Korea, Republic of)

2013-06-15

This study was carried out to reduce patient dose through focus-detector distance, kilovoltage, and a combination of copper filters. In the C, L-spine lateral, Skull AP views were obtained by making changes of 60-100 kV in tube voltage and of 100-200 cm in focus-detector distance and by adding a copper filter when using an auto exposure control device in the digital radiography equipment. The incident dose showed 90 kV, 0.3 mmCu in C-spine lateral with 0.06 mGy under the condition of 200 cm; 100 kV, 0.3 mmCu with 0.40 mGy under the condition of 200 cm and 90 kV 0.3 mmCu in Skull AP with the lowest value of 0.24 mGy under the condition of 140 cm. It was observed that entrance surface dose decreased the most when was increased by 150 cm, 70 kV (C-spine lateral), 81 kV (L-spine lateral). It was also found out that as the between the focus-detector increased in the expansion of the video decreased but the difference was not significant when the distance was 180 cm or more. Skull AP showed the most reduction in the entrance surface dose when the tube voltage was changed by 80 kV, 0.1 mmCu, and 120 cm. Therefore, when using the automatic exposure control device, it is recommended to use the highest tube voltage if possible and to increase focus-detector distance at least by 150-200 cm in wall and 120-140 cm in table in consideration of the radiotechnologist's physical conditions, and to combine 0.1-0.3 mmCu and higher filters. It is thus expected to reduce patient dose by avoiding distortion of images and reducing the entrance surface dose.

Characterization of a monodispersed aerosol exposure system for beagle dogs

International Nuclear Information System (INIS)

Cannon, W.C.; Herring, J.P.; Craig, D.K.

1978-01-01

A monodispersed aerosol exposure system for dogs is described and data are presented on aerosol depositions in the exposure system which could affect the aerosol presented to the animals by reducing the concentration and changing the particle size distribution

Convective heat exposure from large fires to the final filters of ventilation systems

International Nuclear Information System (INIS)

Alvares, N.J.

1979-01-01

The Fire Science Group of the Hazards Control Department, Lawrence Livermore Laboratory has been asked to design a probable fire scenario for a fuel-pellet fabrication facility. This model was used to estimate the potential for thermal damage to the final HEPA filters. These filters would not experience direct fire exposure because they are the last component of the ventilation system before the exhaust air pumps. However, they would be exposed to hot air and fire gases that are drawn into the ventilation system. Because fire is one of the few occurrences that can defeat the containment integrity of facilities where radioactive materials are stored and processed, the fire scenarios must be defined to ensure that containment systems are adequate to meet the threat of such events. Fire-growth calculations are based on the measured fuel load of materials within the fabrication enclosure and on semi-empirical fire-spread models. It is assumed that the fire never becomes ventilation controlled. The temperature rise of ceiling gases and heat transfer from ventilation ducting are calculated using accepted empirical relationships, and the analysis shows that even under the most severe exposure conditions, heat transfer from the duct reduces the fire gas temperatures to levels that would not hamper filter function

The radiation exposure control programme - its effect on design

International Nuclear Information System (INIS)

Simmons, R.B.V.

1975-01-01

The paper discusses how the Power Projects design organization has responded to the problem of operational exposure. This response took the form of an organized formal Programme developed during the Bruce G.S. design phase. This Radiation Exposure Control Programme considered: radiation conditions, number of items requiring attention, number of occasions item requires attention and manhours involved on each occasion. Analysis of these factors and comparison with target values enabled worthwhile reductions to be made in estimated operating exposure. Activity transport studies, reliability and design detail improvements have all received an impetus from the Programme. The Programme which has value both from the economic and the health physics points of view is now a continuing feature of the CANDU plant design process. (author)

An examination of automatic exposure control regimes for two digital radiography systems

International Nuclear Information System (INIS)

Marshall, N W

2009-01-01

The influence of two methods of an automatic exposure control (AEC) setup using a simple measure of detectability is examined as a function of x-ray beam quality for a computed radiography (CR) system and for an indirect conversion digital radiography (DR) system. The regimes assessed were constant air kerma at the detector and the constant contrast noise ratio (CNR). A low scatter geometry was employed with x-ray spectra varying from 60 kV and 1 mm Cu to 125 kV and 2 mm Cu. The CNR was measured using a 2 mm thick Al square of dimension 1 cm by 1 cm. Detectability was quantified via a nominal contrast for a fixed beam quality of 70 kV and 1 mm added Cu filtration, taken from c-d curves measured using the Leeds TO20 test object, for the four x-ray spectra. In addition, objective image quality parameters including modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE) were also measured for both systems at the four different x-ray spectra. It was found that the constant air kerma strategy did not maintain threshold nominal contrast (simple detectability) constant as the x-ray beam mean energy increased, for either the CR system or the DR system. For the CR detector, the threshold nominal contrast for a 1 mm disc increased by a factor of 4.4 from 3.50% to 15.4% as the tube potential was raised from 60 kV to 125 kV, while for the DR detector, the threshold nominal contrast increased by a factor of 3.4, from 2.27% to 7.67% as the tube potential increased from 60 kV to 120 kV. The constant CNR method was more successful at maintaining constant detectability for the c-d discs. The threshold nominal contrast for the 1 mm disc changed by a factor of 1.2, from 4.80% to 5.70% for the CR system, as the spectrum changed from 60 kV to 125 kV. For the indirect conversion detector, the threshold nominal contrast increased from 2.27% to 5.66% (a factor of 1.4 increase). The constant CNR strategy required an increase in air kerma by

An examination of automatic exposure control regimes for two digital radiography systems

Energy Technology Data Exchange (ETDEWEB)

Marshall, N W [Radiation Safety Section, Clinical Physics CAU, Dominion House, 60, Barts Close, St Bartholomew' s Hospital, EC1A 7BE, London (United Kingdom)], E-mail: nicholas.marshall@uz.kuleuven.ac.be

2009-08-07

The influence of two methods of an automatic exposure control (AEC) setup using a simple measure of detectability is examined as a function of x-ray beam quality for a computed radiography (CR) system and for an indirect conversion digital radiography (DR) system. The regimes assessed were constant air kerma at the detector and the constant contrast noise ratio (CNR). A low scatter geometry was employed with x-ray spectra varying from 60 kV and 1 mm Cu to 125 kV and 2 mm Cu. The CNR was measured using a 2 mm thick Al square of dimension 1 cm by 1 cm. Detectability was quantified via a nominal contrast for a fixed beam quality of 70 kV and 1 mm added Cu filtration, taken from c-d curves measured using the Leeds TO20 test object, for the four x-ray spectra. In addition, objective image quality parameters including modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE) were also measured for both systems at the four different x-ray spectra. It was found that the constant air kerma strategy did not maintain threshold nominal contrast (simple detectability) constant as the x-ray beam mean energy increased, for either the CR system or the DR system. For the CR detector, the threshold nominal contrast for a 1 mm disc increased by a factor of 4.4 from 3.50% to 15.4% as the tube potential was raised from 60 kV to 125 kV, while for the DR detector, the threshold nominal contrast increased by a factor of 3.4, from 2.27% to 7.67% as the tube potential increased from 60 kV to 120 kV. The constant CNR method was more successful at maintaining constant detectability for the c-d discs. The threshold nominal contrast for the 1 mm disc changed by a factor of 1.2, from 4.80% to 5.70% for the CR system, as the spectrum changed from 60 kV to 125 kV. For the indirect conversion detector, the threshold nominal contrast increased from 2.27% to 5.66% (a factor of 1.4 increase). The constant CNR strategy required an increase in air kerma by

A Comparison of Item Exposure Control Procedures with the Generalized Partial Credit Model

Science.gov (United States)

Sanchez, Edgar Isaac

2008-01-01

To enhance test security of high stakes tests, it is vital to understand the way various exposure control strategies function under various IRT models. To that end the present dissertation focused on the performance of several exposure control strategies under the generalized partial credit model with an item pool of 100 and 200 items. These…

Overview of DOE Radiation Exposure Information Reporting System (REIRS)

International Nuclear Information System (INIS)

Fix, J.J.; Briscoe, G.J.; Selby, J.M.; Vallario, E.J.

1981-05-01

The purpose of the study is to determine the adequacy of the present system, identify any necessary short-term improvements and propose feasible alternatives for an improved system. The study includes topical reports as follows: current Personnel Dosimetry Practices at DOE Facilities; overview of DOE Radiation Exposure Information Reporting System (REIRS); and alternatives to Provide Upgraded Occupational Exposure Record System. This study constitutes the second report and was a joint effort between Battelle Northwest and EG and G, Idaho Falls. EG and G has been responsible for the respository since the fall of 1978

Design of exposure systems for ELF electric field bioeffects research

International Nuclear Information System (INIS)

Kaune, W.T.; Decker, J.R.; Phillips, R.D.; Gillis, M.F.

1978-01-01

Two systems for exposure and sham-exposure of large numbers of rats and mice to uniform, vertical, 60-Hz electric fields have been constructed. The rat system contains four racks of four rectangular 1.0m x 2.2m exposure-electrodes that are stacked vertically with a separation between adjacent electrodes of 0.41 m. Any two of the four exposure racks may be energized to a maximum field strength of 150 kV/m. Each exposure electrode is equipped with 24 Lexan cages, each of which holds a single rat. The cage floor is a stainless steel screen that serves as one electrode. The system for watering animals is contained entirely within the electrode and does not protrude above the cage's floor, thereby preventing distortion of the exposure field and electrical shock or discharge as the animal drinks. The total capacity of the system is 288 rats. A similar system of two racks of five electrodes each is used to expose as many as 450 mice to fields at a maximum strength of 150 kV/m while sham exposing an equal number. Measurements of the electric field reveal an overall uniformity within 4% over the area to be occupied by experimental animals. The field inside a Lexan cage is reduced by about 3%. No corona-discharge has been detected. Measurements of ozone concentration in the rat and mouse exposure systems show no difference from background levels. Harmonic distortion has been eliminated by damping and filtering the high-voltage supply. Animals housed in close proximity are partially shielded from the electric field; the total body current in a rat model is reduced by 35 ± 5% when rats are placed in adjacent cages. (author)

Trends in occupational exposure control

International Nuclear Information System (INIS)

Wrixon, A.D.

1996-01-01

The latest recommendations of the International Commission on Radiological Protection were agreed in 1990. A major component was the revision of its recommended dose limits, prompted by the revised risk factors relating to exposure to ionising radiation that became available in the second half of the 1980s. But other changes were introduced which necessitated development. In particular a Task Group has been developing guidance on the implementation of the recommendations relating to the protection of workers. This guidance is intended to replace that given in Publication 35. The proposed guidance will be considered by ICRP at its meeting in Paris in November 1996. A guide on occupational radiation protection is also being prepared by the International Atomic Energy Agency. The intention is to develop the principles given in the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources, account being taken of the work of the ICRP Task Group. Members States of the European Communities are obliged to comply with the requirements of a Directive dealing with the basic standards for radiation protection. This Directive has recently been revised in the light of the ICRP recommendations. This paper will discuss these developments and their possible impact on the control of occupational exposure in the UK. (author)

Ayahuasca Exposure: Descriptive Analysis of Calls to US Poison Control Centers from 2005 to 2015.

Science.gov (United States)

Heise, C William; Brooks, Daniel E

2017-09-01

Ayahuasca is a hallucinogenic plant preparation which usually contains the vine Banisteriopsis caapi and the shrub Psychotria viridis. This tea originates from the Amazon Basin where it is used in religious ceremonies. Because interest in these religious groups spreading as well as awareness of use of ayahuasca for therapeutic and recreational purposes, its use is increasing. Banisteriopsis caapi is rich in β-carbolines, especially harmine, tetrahydroharmine and harmaline, which have monoamine oxidase inhibiting (MAOI) activity. Psychotria viridis contains the 5HT2A/2C/1A receptor agonist hallucinogen N,N-dimethyltryptamine (DMT). Usual desired effects include hallucination, dissociation, mood alteration and perception change. Undesired findings previously reported are nausea, vomiting, hypertension, and tachycardia. All human exposure calls reported to the American Association of Poison Controls Centers' (AAPCC) National Poison Data System (NPDS) between September 1, 2005 and September 1, 2015 were reviewed. Cases were filtered for specific plant derived ayahuasca-related product codes. Abstracted data included the following: case age and gender, exposure reason, exposure route, clinical manifestations, treatments given, medical outcomes and fatality. Five hundred and thirty-eight exposures to ayahuasca botanical products were reported. The majority of the calls to poison control centers came from healthcare facilities (83%). The most common route of exposure was ingestion. Most cases were men (437, 81%, 95% CI 77.7% - 84.3%). The median age was 21 (IQR 18-29). Most exposures were acute. Three hundred thirty-seven (63%) were reported to have a major or moderate clinical effect. The most common clinical manifestations reported were hallucinations (35%), tachycardia (34%), agitation (34%), hypertension (16%), mydriasis (13%) and vomiting (6%). Benzodiazepines were commonly given (30%). There were 28 cases in the series who required endotracheal intubation (5

Control in personnel exposure of RCD/FCD facility RLG during the period 2005 - 2008

International Nuclear Information System (INIS)

Murali, S.; Thanamani, S.; Sapkal, J.A.; Bairwa, Satya Manoj

2010-01-01

Full text: Radio Chemistry Wing, RLG, houses Radio Chemistry Division and Fuel Chemistry Division and certain common utility services. The personnel in the facility carry out radiochemical operations involving isotopes of Pu and other actinides. The HP Unit, Radio Chemistry Wing provides essential safety coverage to the personnel of the facility. The lab personnel of RCD/FCD facility at RLG carry out active operations, such operations held in suitable containment systems, under the HP supervision by RHC Unit advising safe work practices. The lab personnel are provided with monitoring programmes viz. TLD, Bio-assay and Lung counting periodically. Presently the dose limit for occupational exposure is 20 mSv per annum with 100 mSv for 5 consecutive calendar years. The present paper on TLD dose report enlists the details of the personnel exposure year wise and highlights the control in personnel exposure due to the safe procedures followed. The decreasing trend in the average personnel exposure over the period 2005 - 2008 validates the practice of adherence to safety procedures, though the amount of activity handled in the facility has increased by a few folds

Models for retrospective quantification of indoor radon exposure in case-control studies

International Nuclear Information System (INIS)

Gerken, M.; Kreienbrock, L.; Wellmann, J.; Kreuzer, M.; Wichmann, H.E.

2000-01-01

In epidemiologic studies on lung cancer risk due to indoor radon the quantification of individual radon exposure over a long time period is one of the main issues. Therefore, radon measurements in one or more dwellings, which in total have been inhabited by the participants for a sufficient time-period, are necessary as well as consideration of changes of building characteristics and ventilation habits, which influence radon concentration. Given data on 1-y alpha-track measurements and personal information from 6,000 participants of case-control studies in West and East Germany, and improved method is developed to assess individual radon exposure histories. Times spent in different rooms of the dwelling, which are known from a personal questionnaire, are taken into account. The time spent outside the house varies substantially among the participants. Therefore, assuming a substantially lower radon exposure outside the dwelling, the residence time constitutes an important aspect of total radon exposure. By means of an analysis of variance, important determinants of indoor radon are identified, namely constant conditions such as type of house, type of construction, year of construction, floor and type of basement, and changeable conditions such as heating system, window insulation, and airing habits. A correction of measurements in former dwellings by factors derived from the analysis is applied if current living conditions differ from those of the participants at the time when they were living in the particular dwellings. In rare cases the adjustment for changes leads to a correction of the measurements with a factor of about 1.4, but a reduction of 5% on average only. Exposure assessment can be improved by considering time at home and changes of building and ventilation conditions that affect radon concentration. The major concern that changes in ventilation habits and building conditions lead to substantial errors in exposure assessment cannot be confirmed in the

Expert system for control rod programming of boiling water reactors

International Nuclear Information System (INIS)

Fukuzaki, T.; Yoshida, K.; Kobayashi, Y.; Matsuura, H.; Hoshi, K.

1986-01-01

Control rod programming, one of the main tasks in reactor core management of boiling water reactors (BWRs), can be successfully accomplished by well-experienced engineers. By use of core performance evaluation codes, their knowledge plays the main role in searching through optimal control rod patterns and exposure points for adjusting notch positions and exchanging rod patterns. An expert system has been developed, based on a method of knowledge engineering, to lighten the engineer's load in control rod programming. This system utilizes an inference engine suited for planning/designing problems, and stores the knowledge of well-experienced engineers in its knowledge base. In this report, the inference engine, developed considering the characteristics of the control rod programming, is introduced. Then the constitution and function of the expert system are discussed

Environmental radioactivity: the importance of controlling exposure of the public: some experiences in Cuba

International Nuclear Information System (INIS)

Fernandez Gomez, Isis Maria

2008-01-01

The nuclear power is offering considerable advantages, it is considering the option to produce energy and the economy has moved in favour of the nuclear power. Therefore, the security is important within of the industry because ensures the control of public exposure and the environment and it plays a crucial role. Public exposure refers to exposure that is not of the direct work with ionizing radiation or the application of nuclear techniques in medical treatment and diagnosis. There are potential sources of discharges into the environment as the spent fuel and the waste disposal. Some of the routes of exposure are atmospheric discharge, liquid discharge, irrigation, environment, decomposition of the rain, food chains, etc. International regulations on subject of radiological safety are set by the IAEA and have a hierarchical order: fundamentals, requirements and guidelines. The International Commission of Radiological Protection and the Committee of the General Assembly of the United Nations are described in the research. The action is exposed in Cuba with regard to nuclear programs that have been realized or that are executed in relation to the control of the exposure of the public in existing applications. It mentions the centralized management of radioactive rights generated, the control of other sources of exposure, and the Red Nacional de Vigilancia Radiologica Ambiental. It also includes numerical data of studies realized on the extent of the sources of public exposure, the external doses received by the Cuban population product of environmental sources of radiation, the estimating of the doses received by the Cuban population by the incorporation of radionuclides present in the water and food. Likewise, the radioactive environmental funds; the phosphate mining; the protection and extraction of oil and the presence of radon inside the house are shown. The exposure to gamma radiation in thermal spas; the exposure to environmental sources of radiation

Case–control study of breast cancer and exposure to synthetic environmental chemicals among Alaska Native women

Directory of Open Access Journals (Sweden)

Adrianne K. Holmes

2014-11-01

Full Text Available Background: Exposure to environmental chemicals may impair endocrine system function. Alaska Native (AN women may be at higher risk of exposure to these endocrine disrupting chemicals, which may contribute to breast cancer in this population. Objective: To measure the association between exposure to select environmental chemicals and breast cancer among AN women. Design: A case–control study of 170 women (75 cases, 95 controls recruited from the AN Medical Center from 1999 to 2002. Participants provided urine and serum samples. Serum was analyzed for 9 persistent pesticides, 34 polychlorinated biphenyl (PCB congeners, and 8 polybrominated diethyl ether (PBDE congeners. Urine was analyzed for 10 phthalate metabolites. We calculated geometric means (GM and compared cases and controls using logistic regression. Results: Serum concentrations of most pesticides and 3 indicator PCB congeners (PCB-138/158; PCB-153, PCB-180 were lower in case women than controls. BDE-47 was significantly higher in case women (GM=38.8 ng/g lipid than controls (GM=25.1 ng/g lipid (p=0.04. Persistent pesticides, PCBs, and most phthalate metabolites were not associated with case status in univariate logistic regression. The odds of being a case were higher for those with urinary mono-(2-ethylhexyl phthalate (MEHP concentrations that were above the median; this relationship was seen in both univariate (OR 2.16, 95% CI 1.16–4.05, p=0.02 and multivariable (OR 2.43, 95% CI 1.13–5.25, p=0.02 logistic regression. Women with oestrogen receptor (ER–/progesterone receptor (PR-tumour types tended to have higher concentrations of persistent pesticides than did ER+/PR+ women, although these differences were not statistically significant. Conclusions: Exposure to the parent compound of the phthalate metabolite MEHP may be associated with breast cancer. However, our study is limited by small sample size and an inability to control for the confounding effects of body mass index

Evaluation of Pulmonary and Systemic Toxicity of Oil Dispersant (COREXIT EC9500A following Acute Repeated Inhalation Exposure

Directory of Open Access Journals (Sweden)

Jenny R. Roberts

2014-01-01

Full Text Available Introduction Oil spill cleanup workers come into contact with numerous potentially hazardous chemicals derived from the oil spills, as well as chemicals applied for mitigation of the spill, including oil dispersants. In response to the Deepwater Horizon Macondo well oil spill in the Gulf of Mexico in 2010, a record volume of the oil dispersant, COREXIT EC9500A, was delivered via aerial applications, raising concern regarding potential health effects that may result from pulmonary exposure to the dispersant. Methods The current study examined the effects on pulmonary functions, cardiovascular functions, and systemic immune responses in rats to acute repeated inhalation exposure of COREXIT EC9500A at 25 mg/m 3 , five hours per day, over nine work days, or filtered air (control. At one and seven days following the last exposure, a battery of parameters was measured to evaluate lung function, injury, and inflammation; cardiovascular function; peripheral vascular responses; and systemic immune responses. Results No significant alterations in airway reactivity were observed at one or seven days after exposure either in baseline values or following metha-choline (MCh inhalation challenge. Although there was a trend for an increase in lung neutrophils and phagocyte oxidant production at one-day post exposure, there were no significant differences in parameters of lung inflammation. In addition, increased blood monocytes and neutrophils, and decreased lymphocyte numbers at one-day post exposure also did not differ significantly from air controls, and no alterations in splenocyte populations, or serum or spleen immunoglobulin M (IgM to antigen were observed. There were no significant differences in peripheral vascular responsiveness to vasoconstrictor and vasodilator agonists or in blood pressure (BP responses to these agents; however, the baseline heart rate (HR and HR responses to isoproterenol (ISO were significantly elevated at one-day post exposure

Pneumocystis jirovecii pneumonia in systemic autoimmune rheumatic disease: A case-control study.

Science.gov (United States)

Tadros, Susan; Teichtahl, Andrew J; Ciciriello, Sabina; Wicks, Ian P

2017-06-01

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic fungal infection that affects the immunocompromised. Patients with systemic autoimmune rheumatic disease are increasingly recognised as an at-risk clinical population with a high mortality. This case-control study examined differences in the characteristics and peripheral blood parameters between patients with systemic autoimmune rheumatic disease who developed PJP and gender, age and disease-matched controls. Historical data collected between 2002 and 2013 at the Royal Melbourne Hospital, Australia were reviewed. Cases were defined by having a systemic autoimmune rheumatic disease and a diagnosis of PJP (either a positive toluidine blue O stain or P. jirovecii PCR, with a concurrent respiratory illness that was clinically consistent with PJP). Controls were matched for age, gender and disease in a 4:1 ratio. Peripheral blood results were retrieved from an in-house pathology database. Clinical information including glucocorticoid exposure, PJP prophylaxis, comorbidities and month of admission were retrieved from medical notes. After adjustment for corticosteroid exposure and C-reactive protein, lymphocyte count on admission (0.4 vs. 1.3; p = 0.04) and at nadir (0.2 vs. 0.8 × 10 9 /L; p = 0.05) was significantly lower in cases than in controls. Cases (n = 11) were more frequently Caucasian rather than non-Caucasian (81.8% vs. 65.9%; p = 0.04). In addition, cases more commonly presented in autumn (March to May) than in other seasons (OR = 7.3; 95% CI: 1.4-38.7; p = 0.02). These data demonstrate that patients with systemic autoimmune rheumatic disease who develop PJP have significantly greater lymphopenia than age, gender and disease-matched controls, independent of corticosteroid exposure, as well as a potential ethnicity and seasonal predilection to PJP. This may help to inform prophylactic guidelines for PJP in these patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Exposure and acute exposure-effects before and after modification of a contaminated humidification system in a synthetic-fibre plant

NARCIS (Netherlands)

Pal, TM; de Monchy, JGR; Groothoff, JW; Post, D

Objective: Follow-up study of exposure and acute exposure-effects after modification to steam humidification of a contaminated cold water system which had caused an outbreak of humidifier fever in a synthetic-fibre plant. Methods: Before and after modification of the system aerobiological

Identification of Sources of Endotoxin Exposure as Input for Effective Exposure Control Strategies.

Science.gov (United States)

van Duuren-Stuurman, Birgit; Gröllers-Mulderij, Mariska; van de Runstraat, Annemieke; Duisterwinkel, Anton; Terwoert, Jeroen; Spaan, Suzanne

2018-02-13

Aim of the present study is to investigate the levels of endotoxins on product samples from potatoes, onions, and seeds, representing a relevant part of the agro-food industry in the Netherlands, to gather valuable insights in possibilities for exposure control measures early in the process of industrial processing of these products. Endotoxin levels on 330 products samples from companies representing the potato, onion, and seed (processing) industry (four potato-packaging companies, five potato-processing companies, five onion-packaging companies, and four seed-processing companies) were assessed using the Limulus Amboecyte Lysate (LAL) assay. As variation in growth conditions (type of soil, growth type) and product characteristics (surface roughness, dustiness, size, species) are assumed to influence the level of endotoxin on products, different types, and growth conditions were considered when collecting the samples. Additionally, waste material, rotten products, felt material (used for drying), and process water were collected. A large variation in the endotoxin levels was found on samples of potatoes, onions, and seeds (overall geometric standard deviation 17), in the range between 0.7 EU g-1 to 16400000 EU g-1. The highest geometric mean endotoxin levels were found in plant material (319600 EU g-1), followed by soil material (49100 EU g-1) and the outer side of products (9300 EU g-1), indicating that removal of plant and soil material early in the process would be an effective exposure control strategy. The high levels of endotoxins found in the limited number of samples from rotten onions indicate that these rotten onions should also be removed early in the process. Mean endotoxin levels found in waste material (only available for seed processing) is similar to the level found in soil material, although the range is much larger. On uncleaned seeds, higher endotoxin levels were found than on cleaned seeds, indicating that cleaning processes are important

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.

Risk Communication in EPA's Controlled Inhalation Exposure Studies and in Support.

Science.gov (United States)

Resnik, David

2017-01-01

On March 28, 2017, the National Academy of Sciences, Engineering, and Medicine (NASEM) released a much-anticipated report on the Environmental Protection Agency's controlled human inhalation exposure studies. This essay reviews the ethical controversies that led to the genesis of the report, summarizes its key findings, and comments on its approach to informing human subjects about the risks of inhalation exposure studies. NASEM's report makes a valuable contribution to our understanding of the scientific and ethical issues involved in conducting human inhalation exposure studies. Its definition of "reasonably foreseeable risks" provides useful guidance to investigators, research participants, and institutional review board members.

In situ exposure to non-directional beacons for air traffic control.

Science.gov (United States)

Joseph, Wout; Goeminne, Francis; Vermeeren, Günter; Verloock, Leen; Martens, Luc

2012-04-01

In situ electromagnetic field exposure of workers and the general public due to non-directional beacons (NDB) for air traffic control is assessed and characterized. For occupational exposure, the maximal measured electric field value is 881.6 V/m and the maximal magnetic field value is 9.1 A/m. The maximum electric fields exceed the International Commission on Non-Ionizing Radiation Protection (ICNIRP) reference levels at all seven NDB sites, and the magnetic fields at two of the seven NDB sites (occupational exposure). Recommendations and compliance distances for workers and the general public are provided. © 2012 Wiley Periodicals, Inc.

Case-control study of gadodiamide-related nephrogenic systemic fibrosis

DEFF Research Database (Denmark)

Marckmann, Peter; Skov, Lone; Rossen, Kristian

2007-01-01

exposed to gadodiamide develop nephrogenic systemic fibrosis. METHODS: We conducted a case-control study of 19 histologically verified cases and 19 sex- and age-matched controls. All subjects had chronic renal failure when exposed to gadodiamide. Clinical, biochemical and pharmacological data were.......02). CONCLUSIONS: Increasing cumulative gadodiamide exposure, high-dose epoietin-beta treatment, and higher serum concentrations of ionized calcium and phosphate increase the risk of gadodiamide-related nephrogenic systemic fibrosis in renal failure patients. Severe cases seem to develop primarily among patients......BACKGROUND: Nephrogenic systemic fibrosis may be caused by gadolinium (Gd)-containing magnetic resonance imaging contrast agents. Most reported cases were associated with one particular agent, gadodiamide. Yet, unidentified cofactors might explain why only a minority of renal failure patients...

Quality control for exposure assessment in epidemiological studies

DEFF Research Database (Denmark)

Bornkessel, C; Blettner, M; Breckenkamp, J

2010-01-01

In the framework of an epidemiological study, dosemeters were used for the assessment of radio frequency electromagnetic field exposure. To check the correct dosemeter's performance in terms of consistency of recorded field values over the entire study period, a quality control strategy...... was developed. In this paper, the concept of quality control and its results is described. From the 20 dosemeters used, 19 were very stable and reproducible, with deviations of a maximum of +/-1 dB compared with their initial state. One device was found to be faulty and its measurement data had to be excluded...... from the analysis. As a result of continuous quality control procedures, the confidence in the measurements obtained during the field work was strengthened significantly....

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.

Control of internal exposure doses of Belarus population

International Nuclear Information System (INIS)

Minenko, V.; Drozdovich, V.; Ulanovski, A.; Ternov, V.I.; Vasilyeva, I.

1997-01-01

Starting from May 1986 instrumental control of internal exposure is being carried out in Belarus using different equipment. In earlier, iodine period, the basic aim of the control was a mass screening of the population for defining of iodine content in thyroid. After the iodine period attention of the radiological control was focused on monitoring of caesium radionuclides content in human bodies of the inhabitants of radioactively contaminated territories. Goals of the control were changing, depending on the time that passed since the day of the accident. Nowadays the National Commission of Belarus recognizes entering of the, Republic into rehabilitation period of the accident of the Chernobyl Nuclear Power Plant. Developed Conception of Protection Measures for the rehabilitation period for the population living at the territories affected by the radioactive contamination in the result of the Chernobyl catastrophe

Computerized Registration System of Occupational Exposure in Nuclear Fuel Cycle in Slovenia

International Nuclear Information System (INIS)

Cernilogar Radez, M.; Krizman, M.

2001-01-01

Full text: In early 1999s the SNSA started to develop a computerised registration system of occupational radiation exposure for workers in a nuclear fuel cycle in Slovenia, which arises from four nuclear facilities: nuclear power plant, research reactor, storage facility and uranium mine. In the period 1985-2000 about 5000 workers altogether were monitored due to exposure in a nuclear fuel cycle in Slovenia (about 1200 employees and 3800 outside workers), with an average of 1000 workers being assessed each calendar year. Four dosimetric services regularly perform personal monitoring of the occupational exposure and all of them have been requested to provide data to the SNSA electronically. The computerised register was put into operation in 2000 enabling prompt control of personal exposures, including annual, 5-year and lifetime doses. Besides individual exposure also collective doses can be evaluated, together with size and time distributions and trends over certain periods. Apart from the total dose, the doses received due to external radiation (gamma, neutrons) and due to internal radiation have been separately recorded into the register. In addition, personal data of workers as well as employee and facility data have been also recorded. Some statistics of dose distributions have been evaluated and the results have been compared to international data. More than 80% of workers from the register have been exposed in the NPP. Workers received the major part of their exposure during the annual outage works. It is found out that in recent years, the average individual and collective doses have shown a rising trend. (author)

Internet-Delivered Exposure Therapy for Fibromyalgia: A Randomized Controlled Trial.

Science.gov (United States)

Hedman-Lagerlöf, Maria; Hedman-Lagerlöf, Erik; Axelsson, Erland; Ljótsson, Brjánn; Engelbrektsson, Johanna; Hultkrantz, Sofia; Lundbäck, Karolina; Björkander, Daniel; Wicksell, Rikard K; Flink, Ida; Andersson, Erik

2018-06-01

Fibromyalgia (FM) is a common and disabling chronic pain disorder, for which existing pharmacological and psychological treatments have yet yielded insufficient effects. Previous literature has shown that exposure therapy may be an effective treatment for chronic pain. This study constitutes the first randomized controlled trial evaluating exposure therapy for FM. A total of 140 participants with diagnosed FM were randomized to a 10-week Internet-delivered exposure treatment (iExp; n=70) or a waitlist control condition (WLC; n=70). Primary outcome measure were FM symptoms and impact, and secondary outcome measures were fatigue, disability, quality of life, pain-related distress and avoidance behaviors, insomnia, depression, and anxiety. Data retention was high (100% data completion at posttreatment for primary outcome, 96% at 6-month follow-up and 94% at 12-month follow-up). Results showed that participants in the iExp group made large and superior improvements compared with WLC on FM symptoms and impact (B, -1.93; z, -10.14; P<0.001, between-group Cohen d=0.90), as well as all secondary outcomes (between-group Cohen d ranging from 0.44 to 1.38) with sustained results. We conclude that iExp seems to be an efficacious treatment for FM compared with no treatment, and the results also highlight the potential increase of accessibility by using the Internet format to deliver psychological treatments for these patients. Future trials with active control conditions are warranted.

The potential reproductive, neurobehavioral and systemic effects of soluble sodium tungstate exposure in Sprague-Dawley rats

International Nuclear Information System (INIS)

McInturf, S.M.; Bekkedal, M.Y.V.; Wilfong, E.; Arfsten, D.; Chapman, G.; Gunasekar, P.G.

2011-01-01

The debate on tungsten (W) is fostered by its continuous usage in military munitions. Reports demonstrate W solubilizes in soil and can migrate into drinking water supplies and, therefore, is a potential health risk to humans. This study evaluated the reproductive, systemic and neurobehavioral effects of sodium tungstate (NaW) in rats following 70 days of daily pre-and postnatal exposure via oral gavage to 5, 62.5 and 125 mg/kg/day of NaW through mating, gestation and weaning (PND 0-20). Daily administration of NaW produced no overt evidence of toxicity and had no apparent effect on mating success or offspring physical development. Distress vocalizations were elevated in F 1 offspring from the high dose group, whereas righting reflex showed unexpected sex differences where males demonstrated faster righting than females; however, the effects were not dose-dependent. Locomotor activity was affected in both low and high-dose groups of F 1 females. Low-dose group showed increased distance traveled, more time in ambulatory movements and less time in stereotypic behavior than controls or high dose animals. The high-dose group had more time in stereotypical movements than controls, and less time resting than controls and the lowest exposure group. Maternal retrieval was not affected by NaW exposure. Tungsten analysis showed a systemic distribution of NaW in both parents and offspring, with preferential uptake within the immune organs, including the femur, spleen and thymus. Histopathological evidence suggested no severe chronic injury or loss of function in these organs. However, the heart showed histological lesions, histiocytic inflammation from minimal to mild with cardiomyocyte degeneration and necrosis in several P 0 animals of 125 mg NaW dose group. The result of this study suggests that pre and postnatal exposure to NaW may produce subtle neurobehavioral effects in offspring related to motor activity and emotionality.

Evaluation of Pulmonary and Systemic Toxicity of Oil Dispersant (COREXIT EC9500A(®)) Following Acute Repeated Inhalation Exposure.

Science.gov (United States)

Roberts, Jenny R; Anderson, Stacey E; Kan, Hong; Krajnak, Kristine; Thompson, Janet A; Kenyon, Allison; Goldsmith, William T; McKinney, Walter; Frazer, David G; Jackson, Mark; Fedan, Jeffrey S

2014-01-01

Oil spill cleanup workers come into contact with numerous potentially hazardous chemicals derived from the oil spills, as well as chemicals applied for mitigation of the spill, including oil dispersants. In response to the Deepwater Horizon Macondo well oil spill in the Gulf of Mexico in 2010, a record volume of the oil dispersant, COREXIT EC9500A, was delivered via aerial applications, raising concern regarding potential health effects that may result from pulmonary exposure to the dispersant. The current study examined the effects on pulmonary functions, cardiovascular functions, and systemic immune responses in rats to acute repeated inhalation exposure of COREXIT EC9500A at 25 mg/m(3), five hours per day, over nine work days, or filtered air (control). At one and seven days following the last exposure, a battery of parameters was measured to evaluate lung function, injury, and inflammation; cardiovascular function; peripheral vascular responses; and systemic immune responses. No significant alterations in airway reactivity were observed at one or seven days after exposure either in baseline values or following methacholine (MCh) inhalation challenge. Although there was a trend for an increase in lung neutrophils and phagocyte oxidant production at one-day post exposure, there were no significant differences in parameters of lung inflammation. In addition, increased blood monocytes and neutrophils, and decreased lymphocyte numbers at one-day post exposure also did not differ significantly from air controls, and no alterations in splenocyte populations, or serum or spleen immunoglobulin M (IgM) to antigen were observed. There were no significant differences in peripheral vascular responsiveness to vasoconstrictor and vasodilator agonists or in blood pressure (BP) responses to these agents; however, the baseline heart rate (HR) and HR responses to isoproterenol (ISO) were significantly elevated at one-day post exposure, with resolution by day 7. In summary, acute

Vehicle-manipulator systems modeling for simulation, analysis, and control

CERN Document Server

From, Pal Johan; Pettersen, Kristin Ytterstad

2014-01-01

Furthering the aim of reducing human exposure to hazardous environments, this monograph presents a detailed study of the modeling and control of vehicle-manipulator systems. The text shows how complex interactions can be performed at remote locations using systems that combine the manipulability of robotic manipulators with the ability of mobile robots to locomote over large areas.  The first part studies the kinematics and dynamics of rigid bodies and standard robotic manipulators and can be used as an introduction to robotics focussing on robust mathematical modeling. The monograph then moves on to study vehicle-manipulator systems in great detail with emphasis on combining two different configuration spaces in a mathematically sound way. Robustness of these systems is extremely important and Modeling and Control of Vehicle-manipulator Systems effectively represents the dynamic equations using a mathematically robust framework. Several tools from Lie theory and differential geometry are used to obtain glob...

Harmonisation of food categorisation systems for dietary exposure assessments among European children

DEFF Research Database (Denmark)

De Neve, Melissa; Sioen, Isabelle; Boon, Polly

2010-01-01

Within the European project called EXPOCHI (Individual Food Consumption Data and Exposure Assessment Studies for Children), 14 different European individual food consumption databases of children were used to conduct harmonised dietary exposure assessments for lead, chromium, selenium and food...... colours. For this, two food categorisation systems were developed to classify the food consumption data in such a way that these could be linked to occurrence data of the considered compounds. One system served for the exposure calculations of lead, chromium and selenium. The second system was developed...... for the exposure assessment of food colours. The food categories defined for the lead, chromium and selenium exposure calculations were used as a basis for the food colour categorisation, with adaptations to optimise the linkage with the food colour occurrence data. With this work, an initial impetus was given...

Remote system for monitoring and control of controlled area of nuclear installation

Energy Technology Data Exchange (ETDEWEB)

Assuncao, Daniel Gomes de; Minhoni, Danilo Carlos Rossetto [Departamento de Ciencias da Administracao e Tecnologia. Centro Universitario de Araraquara (UNIARA) Araraquara, SP (Brazil); Farias, Marcos Sant' anna de; Santos, Isaac J.A. Luquetti dos, E-mail: luquetti@ien.gov.br [Instituto Engenharia Nuclear (IEN/CNEN-RJ), Rio Janeiro, RJ (Brazil). Divisao de Instrumentacao e Confiabilidade Humana

2011-07-01

The maintenance activities in controlled areas of nuclear facilities require adequate planning and control so that these activities do not cause to the worker an undue exposure to radioactivity. For maximum safety of workers from these places, there are standards that determine the maximum radiation dose that a worker can receive. From this context, the objective of this research is to develop a remote system that shows remotely the maintenance tasks being carried out in this work environment; monitors information provided by radiation monitoring devices installed at workplace; tracks the time to carry out scheduled maintenance, reporting alarm if this time is exceeded or not. The system has video camera, radiation monitoring device, interface card to transmit data via ethernet and graphical user interface, developed using the LABVIEW application. The principal objective is to improve the safety and to preserve the worker's health. (author)

Remote system for monitoring and control of controlled area of nuclear installation

International Nuclear Information System (INIS)

Assuncao, Daniel Gomes de; Minhoni, Danilo Carlos Rossetto; Farias, Marcos Sant'anna de; Santos, Isaac J.A. Luquetti dos

2011-01-01

The maintenance activities in controlled areas of nuclear facilities require adequate planning and control so that these activities do not cause to the worker an undue exposure to radioactivity. For maximum safety of workers from these places, there are standards that determine the maximum radiation dose that a worker can receive. From this context, the objective of this research is to develop a remote system that shows remotely the maintenance tasks being carried out in this work environment; monitors information provided by radiation monitoring devices installed at workplace; tracks the time to carry out scheduled maintenance, reporting alarm if this time is exceeded or not. The system has video camera, radiation monitoring device, interface card to transmit data via ethernet and graphical user interface, developed using the LABVIEW application. The principal objective is to improve the safety and to preserve the worker's health. (author)

Estimation of effectiveness of automatic exposure control in computed tomograph scanner

International Nuclear Information System (INIS)

Akhilesh, Philomina; Sharma, S.D.; Datta, D.; Kulkarni, Arti

2018-01-01

With the advent of multiple detector array technology, the use of Computed Tomography (CT) scanning has increase tremendously. Computed Tomography examinations deliver relatively high radiation dose to patients in comparison with conventional radiography. It is therefore required to reduce the dose delivered in CT scans without compromising the image quality. Several parameters like applied potential, tube current, scan length, pitch etc. influence the dose delivered in CT scans. For optimization of patient dose and image quality, all modern CT scanners are enabled with Automatic Exposure Control (AEC) systems. The aim of this work is to compare the dose delivered during CT scans performed with and without AEC in order to estimate the effectiveness of AEC techniques used in CT scanners of various manufacturer

In Vivo versus Augmented Reality Exposure in the Treatment of Small Animal Phobia: A Randomized Controlled Trial.

Directory of Open Access Journals (Sweden)

Cristina Botella

Full Text Available Although in vivo exposure is the treatment of choice for specific phobias, some acceptability problems have been associated with it. Virtual Reality exposure has been shown to be as effective as in vivo exposure, and it is widely accepted for the treatment of specific phobias, but only preliminary data are available in the literature about the efficacy of Augmented Reality. The purpose of the present study was to examine the efficacy and acceptance of two treatment conditions for specific phobias in which the exposure component was applied in different ways: In vivo exposure (N = 31 versus an Augmented Reality system (N = 32 in a randomized controlled trial. "One-session treatment" guidelines were followed. Participants in the Augmented Reality condition significantly improved on all the outcome measures at post-treatment and follow-ups. When the two treatment conditions were compared, some differences were found at post-treatment, favoring the participants who received in vivo exposure. However, these differences disappeared at the 3- and 6-month follow-ups. Regarding participants' expectations and satisfaction with the treatment, very positive ratings were reported in both conditions. In addition, participants from in vivo exposure condition considered the treatment more useful for their problem whereas participants from Augmented Reality exposure considered the treatment less aversive. Results obtained in this study indicate that Augmented Reality exposure is an effective treatment for specific phobias and well accepted by the participants.

In Vivo versus Augmented Reality Exposure in the Treatment of Small Animal Phobia: A Randomized Controlled Trial.

Science.gov (United States)

Botella, Cristina; Pérez-Ara, M Ángeles; Bretón-López, Juana; Quero, Soledad; García-Palacios, Azucena; Baños, Rosa María

2016-01-01

Although in vivo exposure is the treatment of choice for specific phobias, some acceptability problems have been associated with it. Virtual Reality exposure has been shown to be as effective as in vivo exposure, and it is widely accepted for the treatment of specific phobias, but only preliminary data are available in the literature about the efficacy of Augmented Reality. The purpose of the present study was to examine the efficacy and acceptance of two treatment conditions for specific phobias in which the exposure component was applied in different ways: In vivo exposure (N = 31) versus an Augmented Reality system (N = 32) in a randomized controlled trial. "One-session treatment" guidelines were followed. Participants in the Augmented Reality condition significantly improved on all the outcome measures at post-treatment and follow-ups. When the two treatment conditions were compared, some differences were found at post-treatment, favoring the participants who received in vivo exposure. However, these differences disappeared at the 3- and 6-month follow-ups. Regarding participants' expectations and satisfaction with the treatment, very positive ratings were reported in both conditions. In addition, participants from in vivo exposure condition considered the treatment more useful for their problem whereas participants from Augmented Reality exposure considered the treatment less aversive. Results obtained in this study indicate that Augmented Reality exposure is an effective treatment for specific phobias and well accepted by the participants.

A controlled study of virtual reality exposure therapy for the fear of flying.

Science.gov (United States)

Rothbaum, B O; Hodges, L; Smith, S; Lee, J H; Price, L

2000-12-01

Fear of flying (FOF) affects an estimated 10-25% of the population. Patients with FOF (N = 49) were randomly assigned to virtual reality exposure (VRE) therapy, standard exposure (SE) therapy, or a wait-list (WL) control. Treatment consisted of 8 sessions over 6 weeks, with 4 sessions of anxiety management training followed by either exposure to a virtual airplane (VRE) or exposure to an actual airplane at the airport (SE). A posttreatment flight on a commercial airline measured participants' willingness to fly and anxiety during flight immediately after treatment. The results indicated that VRE and SE were both superior to WL, with no differences between VRE and SE. The gains observed in treatment were maintained at a 6-month follow up. By 6 months posttreatment, 93% of VRE participants and 93% of SE participants had flown. VRE therapy and SE therapy for treatment of FOF were unequivocally supported in this controlled study.

Electronic Cigarette Exposure: Calls to Wisconsin Poison Control Centers, 2010–2015.

Science.gov (United States)

Weiss, Debora; Tomasallo, Carrie D; Meiman, Jon G; Creswell, Paul D; Melstrom, Paul C; Gummin, David D; Patel, Disa J; Michaud, Nancy T; Sebero, Heather A; Anderson, Henry A

2016-12-01

E-cigarettes are battery-powered devices that deliver nicotine and flavorings by aerosol and have been marketed in the United States since 2007. Because e-cigarettes have increased in popularity, toxicity potential from device misuse and malfunction also has increased. National data indicate that during 2010–2014, exposure calls to US poison control centers increased only 0.3% for conventional cigarette exposures, whereas calls increased 41.7% for e-cigarette exposures. We characterized cigarette and e-cigarette exposure calls to the Wisconsin Poison Center January 1, 2010 through October 10, 2015. We compared cigarette and e-cigarette exposure calls by exposure year, demographic characteristics, caller site, exposure site, exposure route, exposure reason, medical outcome, management site, and level of care at a health care facility. During January 2010 to October 2015, a total of 98 e-cigarette exposure calls were reported, and annual exposure calls increased approximately 17-fold, from 2 to 35. During the same period, 671 single-exposure cigarette calls with stable annual call volumes were reported. E-cigarette exposure calls were associated with children aged ≤5 years (57/98, 58.2%) and adults aged ≥20 years (30/98, 30.6%). Cigarette exposure calls predominated among children aged ≤5 years (643/671, 95.8%). The frequency of e-cigarette exposure calls to the Wisconsin Poison Center has increased and is highest among children aged ≤5 years and adults. Strategies are warranted to prevent future poisonings from these devices, including nicotine warning labels and public advisories to keep e-cigarettes away from children.

A suggested guideline for exposure control from natural radioactivity in future buildings

International Nuclear Information System (INIS)

Nambi, K.S.V.; Shukla, V.K.

1991-01-01

Naturally occurring radionuclides in building materials are one of the sources of radiation exposure to the population. Their concentrations vary by about 2 to 3 orders of magnitude at different geographical locations. This paper proposes three control methodologies for keeping the population exposure as low as reasonably achievable. Tentative recommendations are also included. (author). 11 refs., 3 tabs., 2 appendixes

Comparison of poison exposure data: NHIS and TESS data.

Science.gov (United States)

Polivka, Barbara J; Elliott, Michael B; Wolowich, William R

2002-01-01

To identify age-adjusted poisoning episode rates, and poison control center contacts due to poisonings in children under 6 years old based on 1997-1999 National Health Interview Survey data; and compare findings with 1997-1999 Toxic Exposure Surveillance System data. Secondary analysis of National Health Interview Survey poisoning episode data for children 5 years and younger. Respondents were asked about poison exposures during the previous 3 months. Based on National Health Interview Survey population weighted data there were 196/10,000 poisonings to young children < 6 years. These exposures resulted primarily from harmful solid or liquid substances. A poison control center was called in 86% of exposures to children < 4 years, but only in 70% of the 4-5 year old exposures. The odds of a poison control center not being called were 3.2 times greater for 4-5 year olds (compared to < or = 3 years) and 4.5 times greater for African-American (compared with White-Americans). Comparison of National Health Interview Survey data with data in the 1997-1999 Annual Reports of the Toxic Exposure Surveillance System revealed the number of estimated exposures in the National Health Interview Survey data were approximately half those reported in the Toxic Exposure Surveillance System data. In both datasets, children 1-2 years of age had the highest percent of poisoning exposures. Using multiple datasets to explore poisoning rates in young children provides a broader perspective. Differences in findings reflect divergent data collection methods and biases inherent in each database. Although the majority of National Health Interview Survey respondents reporting contacting a poison control center for a poisoning exposure, rates are lower in specific subgroups indicating a need for targeted educational efforts.

Father's occupational exposure to carcinogenic agents and childhood acute leukemia: a new method to assess exposure (a case-control study

Directory of Open Access Journals (Sweden)

Rodriguez-Rivera Maria

2008-01-01

Full Text Available Abstract Background Medical research has not been able to establish whether a father's occupational exposures are associated with the development of acute leukemia (AL in their offspring. The studies conducted have weaknesses that have generated a misclassification of such exposure. Occupations and exposures to substances associated with childhood cancer are not very frequently encountered in the general population; thus, the reported risks are both inconsistent and inaccurate. In this study, to assess exposure we used a new method, an exposure index, which took into consideration the industrial branch, specific position, use of protective equipment, substances at work, degree of contact with such substances, and time of exposure. This index allowed us to obtain a grade, which permitted the identification of individuals according to their level of exposure to known or potentially carcinogenic agents that are not necessarily specifically identified as risk factors for leukemia. The aim of this study was to determine the association between a father's occupational exposure to carcinogenic agents and the presence of AL in their offspring. Methods From 1999 to 2000, a case-control study was performed with 193 children who reside in Mexico City and had been diagnosed with AL. The initial sample-size calculation was 150 children per group, assessed with an expected odds ratio (OR of three and a minimum exposure frequency of 15.8%. These children were matched by age, sex, and institution with 193 pediatric surgical patients at secondary-care hospitals. A questionnaire was used to determine each child's background and the characteristics of the father's occupation(s. In order to determine the level of exposure to carcinogenic agents, a previously validated exposure index (occupational exposure index, OEI was used. The consistency and validity of the index were assessed by a questionnaire comparison, the sensory recognition of the work area, and an

An Examination of Exposure Control and Content Balancing Restrictions on Item Selection in CATs Using the Partial Credit Model.

Science.gov (United States)

Davis, Laurie Laughlin; Pastor, Dena A.; Dodd, Barbara G.; Chiang, Claire; Fitzpatrick, Steven J.

2003-01-01

Examined the effectiveness of the Sympson-Hetter technique and rotated content balancing relative to no exposure control and no content rotation conditions in a computerized adaptive testing system based on the partial credit model. Simulation results show the Sympson-Hetter technique can be used with minimal impact on measurement precision,…

Leptospira Exposure and Waste Pickers: A Case-Control Seroprevalence Study in Durango, Mexico

Science.gov (United States)

Alvarado-Esquivel, Cosme; Hernandez-Tinoco, Jesus; Sanchez-Anguiano, Luis Francisco; Ramos-Nevarez, Agar; Cerrillo-Soto, Sandra Margarita; Guido-Arreola, Carlos Alberto

2015-01-01

Background Infection with Leptospira may occur by contact with Leptospira-infected animals. Waste pickers are in contact with rodents and dogs while picking in the garbage. Whether waste pickers are at risk for Leptospira infection is largely unknown. This study was aimed to determine the association of Leptospira IgG seroprevalence with the occupation of waste picking, and to determine the epidemiological characteristics of the waste pickers with Leptospira exposure. Methods Through a case-control study, we determined the seroprevalence of anti-Leptospira IgG antibodies in 90 waste pickers and 90 age- and gender-matched control subjects in Durango City, Mexico using an enzyme immunoassay. Data were analyzed by bivariate and multivariate analyses. Results The prevalence of anti-Leptospira IgG antibodies was similar in waste pickers (4/90: 4.4%) to that in control subjects (5/90: 5.6%) (P = 1.00). Bivariate analysis showed that Leptospira exposure in waste pickers was associated with increasing age (P = 0.009), no education (P = 0.008), and consumption of rat meat (P = 0.04). However, these associations were no longer found by multivariate analysis. Leptospira exposure in waste pickers was not associated with health status, duration in the activity, wearing hand gloves and facemasks, history of injuries with sharp material of the garbage, or contact with animals or soil. Conclusions This is the first study about Leptospira exposure in waste pickers. Results suggest that waste pickers are not at increasing risk for Leptospira exposure in Durango City, Mexico. Further research with a larger sample size to elucidate the association of Leptospira exposure with waste picking activity is needed. PMID:26124911

Leptospira Exposure and Waste Pickers: A Case-Control Seroprevalence Study in Durango, Mexico.

Science.gov (United States)

Alvarado-Esquivel, Cosme; Hernandez-Tinoco, Jesus; Sanchez-Anguiano, Luis Francisco; Ramos-Nevarez, Agar; Cerrillo-Soto, Sandra Margarita; Guido-Arreola, Carlos Alberto

2015-08-01

Infection with Leptospira may occur by contact with Leptospira-infected animals. Waste pickers are in contact with rodents and dogs while picking in the garbage. Whether waste pickers are at risk for Leptospira infection is largely unknown. This study was aimed to determine the association of Leptospira IgG seroprevalence with the occupation of waste picking, and to determine the epidemiological characteristics of the waste pickers with Leptospira exposure. Through a case-control study, we determined the seroprevalence of anti-Leptospira IgG antibodies in 90 waste pickers and 90 age- and gender-matched control subjects in Durango City, Mexico using an enzyme immunoassay. Data were analyzed by bivariate and multivariate analyses. The prevalence of anti-Leptospira IgG antibodies was similar in waste pickers (4/90: 4.4%) to that in control subjects (5/90: 5.6%) (P = 1.00). Bivariate analysis showed that Leptospira exposure in waste pickers was associated with increasing age (P = 0.009), no education (P = 0.008), and consumption of rat meat (P = 0.04). However, these associations were no longer found by multivariate analysis. Leptospira exposure in waste pickers was not associated with health status, duration in the activity, wearing hand gloves and facemasks, history of injuries with sharp material of the garbage, or contact with animals or soil. This is the first study about Leptospira exposure in waste pickers. Results suggest that waste pickers are not at increasing risk for Leptospira exposure in Durango City, Mexico. Further research with a larger sample size to elucidate the association of Leptospira exposure with waste picking activity is needed.

Imaging a fossil oolitic system with GPR, insights into the exposures of the Isle of Portland (UK)

DEFF Research Database (Denmark)

Moreau, Julien; Hansen, Trine Lykke; Nielsen, Lars

of years. The regional exposure quality is very high with a potential 3D control. The site has seen generations of geologist trainees coming for field work. The Wessex Basin where the Isle is sitting contains an active petroleum system and the geologists visiting/training there use the carbonates...

Exposure and non-fear emotions: A randomized controlled study of exposure-based and rescripting-based imagery in PTSD treatment.

Science.gov (United States)

Langkaas, Tomas Formo; Hoffart, Asle; Øktedalen, Tuva; Ulvenes, Pål G; Hembree, Elizabeth A; Smucker, Mervin

2017-10-01

Interventions involving rescripting-based imagery have been proposed as a better approach than exposure-based imagery when posttraumatic stress disorder (PTSD) is associated with emotions other than fear. Prior research led to the study's hypotheses that (a) higher pretreatment non-fear emotions would predict relatively better response to rescripting as compared to exposure, (b) rescripting would be associated with greater reduction in non-fear emotions, and (c) pretreatment non-fear emotions would predict poor response to exposure. A clinically representative sample of 65 patients presenting a wide range of traumas was recruited from patients seeking and being offered PTSD treatment in an inpatient setting. Subjects were randomly assigned to 10 weeks of treatment involving either rescripting-based imagery (Imagery Rescripting; IR) or exposure-based imagery (Prolonged Exposure; PE). Patients were assessed on outcome and emotion measures at pretreatment, posttreatment and 12 months follow-up. Comparison to control benchmarks indicated that both treatments were effective, but no outcome differences between them appeared. None of the initial hypotheses were supported. The results from this study challenge previous observations and hypotheses about exposure mainly being effective for fear-based PTSD and strengthen the notion that exposure-based treatment is a generally effective treatment for all types of PTSD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of long-term (2 years) exposure of mouse brains to global system for mobile communication (GSM) radiofrequency fields on astrocytic immunoreactivity.

Science.gov (United States)

Court-Kowalski, Stefan; Finnie, John W; Manavis, Jim; Blumbergs, Peter C; Helps, Stephen C; Vink, Robert

2015-04-01

This study was designed to determine whether long-term (2 years) brain exposure to mobile telephone radiofrequency (RF) fields produces any astrocytic activation as these glia react to a wide range of neural perturbations by astrogliosis. Using a purpose-designed exposure system at 900 MHz, mice were given a single, far-field whole body exposure at a specific absorption rate of 4 W/kg on five successive days per week for 104 weeks. Control mice were sham-exposed or freely mobile in a cage to control any stress caused by immobilization in the exposure module. Brains were perfusion-fixed with 4% paraformaldehyde and three coronal levels immunostained for glial fibrillary acidic protein (GFAP). These brain slices were then examined by light microscopy and the amount of this immunomarker quantified using a color deconvolution method. There was no change in astrocytic GFAP immunostaining in brains after long-term exposure to mobile telephony microwaves compared to control (sham-exposed or freely moving caged mice). It was concluded that long-term (2 years) exposure of murine brains to mobile telephone RF fields did not produce any astrocytic reaction (astrogliosis) detectable by GFAP immunostaining. © 2015 Wiley Periodicals, Inc.

Performance of an automatic dose control system for CT. Patient studies

Energy Technology Data Exchange (ETDEWEB)

Stumpp, P.; Gosch, D.; Kuehn, A.; Sorge, I.; Kahn, T. [Universitaetsklinikum Leipzig (Germany). Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie; Weber, D. [St. Elisabeth-Krankenhaus Leipzig (Germany). Roentgendiagnostik; Lehmkuhl, L. [Leipzig Univ. - Herzzentrum (Germany). Diagnostische und Interventionelle Radiologie; Nagel, H.D. [Dr. HD Nagel, Wissenschaft und Technik fuer die Radiologie, Buchholz (Germany)

2013-02-15

Purpose: To study the effect of an automatic dose control (ADC) system with adequate noise characteristic on the individual perception of image noise and diagnostic acceptance compared to objectively measured image noise and the dose reductions achieved in a representative group of patients. Materials and Methods: In a retrospective study two matched cohorts of 20 patients each were identified: a manual cohort with exposure settings according to body size (small - regular - large) and an ADC cohort with exposure settings calculated by the ADC system (DoseRight 2.0 trademark, Philips Healthcare). For each patient, 12 images from 6 defined anatomic levels from contrast-enhanced scans of chest and abdomen/pelvis were analyzed by 4 independent readers concerning image noise and diagnostic acceptance on a five-point Likert scale and evaluated for objectively measured image noise. Radiation exposure was calculated from recorded exposure data. Results: Use of the ADC system reduced the average effective dose for patients by 36 % in chest scans (3.2 vs. 4.9 mSv) and by 17 % in abdomen/pelvis scans (7.6 vs. 8.3 mSv). Average objective noise was slightly lower in the manual cohort (11.1 vs. 12.8 HU), correlating with a slightly better rating in subjective noise score (4.4 vs. 4.2). However, diagnostic acceptance was rated almost equal in both cohorts with excellent image quality (4.6 vs. 4.5). Conclusion: Use of an ADC system with adequate noise characteristic leads to significant reductions in radiation exposure for patients while maintaining excellent image quality. (orig.)

Exposure to electronic nicotine delivery systems (ENDS) visual imagery increases smoking urge and desire.

Science.gov (United States)

King, Andrea C; Smith, Lia J; Fridberg, Daniel J; Matthews, Alicia K; McNamara, Patrick J; Cao, Dingcai

2016-02-01

Use and awareness of electronic nicotine delivery systems (ENDS; also known as electronic cigarettes or e-cigarettes) has increased rapidly in recent years, particularly among young adults. As use of ENDS resembles traditional smoking in both hand-to-mouth movements and inhalation and exhalation behaviors, we determined whether exposure to e-cigarette use via video exposure would act as a cue to elicit urge and desire for a combustible cigarette. Young adult smokers (mean age of 26.3 ± 4.1 years) were randomized to view a brief video montage of advertisements depicting either e-cigarette vaping (n = 38) or bottled water drinking (n = 40). Pre- and postcue exposure assessments were conducted in a controlled laboratory setting without other smoking or vaping cues present or behaviors allowed. Primary outcomes included change from pre-exposure baseline in smoking urge (Brief Questionnaire of Smoking Urges) and desire for a combustible and e-cigarette (visual analogue scales). Results showed that relative to exposure to the bottled water video, exposure to the ENDS video significantly increased smoking urge (p e-cigarette (p < .001). These findings provide preliminary evidence that passive exposure to video imagery of ENDS use may generalize as a condition cue and evoke urges for a combustible cigarette in young adult smokers. It remains to be determined whether such increases in urge and desire correspond to increases in actual smoking behavior. (c) 2016 APA, all rights reserved).

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

High Seroprevalence of Leptospira Exposure in Meat Workers in Northern Mexico: A Case-Control Study

Science.gov (United States)

Alvarado-Esquivel, Cosme; Hernandez-Tinoco, Jesus; Sanchez-Anguiano, Luis Francisco; Ramos-Nevarez, Agar; Cerrillo-Soto, Sandra Margarita; Saenz-Soto, Leandro; Martinez-Ramirez, Lucio

2016-01-01

Background The seroepidemiology of Leptospira infection in workers occupationally exposed to raw meat has been poorly studied. This work aimed to determine the association between Leptospira exposure and the occupation of meat worker, and to determine the seroprevalence association with socio-demographic, work, clinical and behavioral characteristics of the meat workers studied. Methods We performed a case-control study in 124 meat workers and 124 age- and gender-matched control subjects in Durango City, Mexico. Sera of cases and controls were analyzed for anti-Leptospira IgG antibodies using a commercially available enzyme immunoassay. Data of meat workers were obtained with the aid of a questionnaire. The association of Leptospira exposure with the characteristics of meat workers was analyzed by bivariate and multivariate analyses. Results Anti-Leptospira IgG antibodies were found in 22 (17.7%) of 124 meat workers and in eight (6.5%) of 124 controls (OR = 3.12; 95% CI: 1.33 - 7.33; P = 0.006). Seroprevalence of Leptospira infection was similar between male butchers (17.6%) and female butchers (18.2%) (P = 1.00). Multivariate analysis of socio-demographic, work and behavioral variables showed that Leptospira exposure was associated with duration in the activity, rural residence, and consumption of snake meat and unwashed raw fruits. Conclusions This is the first case-control study of the association of Leptospira exposure with the occupation of meat worker. Results indicate that meat workers represent a risk group for Leptospira exposure. Risk factors for Leptospira exposure found in this study may help in the design of optimal preventive measures against Leptospira infection. PMID:26858797

Dialogical Exposure with Traumatically Bereaved Bosnian Women: Findings from a Controlled Trial.

Science.gov (United States)

Hagl, Maria; Powell, Steve; Rosner, Rita; Butollo, Willi

2015-01-01

In this trial, we compared the relative efficacy of dialogical exposure group treatment using Gestalt empty-chair method with a supportive group in the treatment of symptoms stemming from traumatic loss in a post-war society. One-hundred and nineteen women whose husbands were either killed or registered as missing during the war in Bosnia and Herzegovina were quasi-randomized to seven sessions of group treatment with dialogical exposure or to an active control condition. Both interventions resulted in significant improvement from baseline to post-treatment for both kinds of loss, in terms of post-traumatic symptoms, general mental health and grief reactions, with the exception of depression and traumatic grief in the control condition. Regarding mean effect sizes (Cohen's d), pre-treatment to post-treatment improvements were moderate (d = 0.56) for the dialogical exposure group and small (d = 0.34) for the supportive group. Treatment gains were maintained at least until the 1-year follow-up. In controlled comparisons, dialogical exposure was superior concerning traumatic grief (Cohen's d = 0.37) and post-traumatic avoidance (d = 0.73) at post-treatment. Results show that short-term dialogical exposure group treatment was moderately effective in treating traumatically bereaved women. Research attests to high levels of symptoms among post-war civil populations, in particular, when a loved one was killed, which can lead not only to trauma reactions but also to severe separation distress. Grieving the loss of a loved one is hampered if the death remains unconfirmed. Unconfirmed loss could be conceptualized as unfinished business in terms of Gestalt therapy, which offers empty-chair dialogue for resolving unfinished business and grief. Dialogical exposure therapy (DET) supports the client in gaining awareness of and expressing his or her inner dialogues concerning the traumatic event, using Gestalt empty-chair method. Short-term DET was effective in

The Relative Effects of Manual Versus Automatic Exposure Control on Radiation Dose to Vital Organs in Total Hip Arthroplasty.

Science.gov (United States)

Harper, Katharine D; Li, Shidong; Jennings, Rachel; Amer, Kamil M; Haydel, Christopher; Ali, Sayed

2018-01-01

Technologic advances have reduced medical radiation exposure while maintaining image quality. The purpose of this study was to determine the effects of the presence of total hip arthroplasty implants, compared with native hips, on radiation exposure of the most radiosensitive organs when manual and automatic exposure control settings are used. Detection probes were placed at six locations (stomach, sigmoid colon, right pelvic wall, left pelvic wall, pubic symphysis, and anterior pubic skin) in a cadaver. Radiographs were obtained with the use of manual and automatic exposure control protocols, with exposures recorded. A total hip arthroplasty implant was placed in the cadaver, probe positioning was confirmed, and the radiographs were repeated, with exposure values recorded. The control probe placed at the stomach had values ranging from 0.00 mSv to 0.01 mSv in protocols with and without implants. With the manual protocol, exposures in the pelvis ranged from 0.36 mSv to 2.74 mSv in the native hip and from 0.33 mSv to 2.24 mSv after implant placement. The increases in exposure after implant placement, represented as relative risk, were as follows: stomach, 1.000; pubic symphysis, 0.818; left pelvic wall, 1.381; sigmoid colon, 1.550; right pelvic wall, 0.917; and anterior pubic skin, 1.015. With automatic exposure control, exposures in the pelvis ranged from 0.07 mSv to 0.89 mSv in the native hip and from 0.21 mSv to 1.15 mSv after implant placement. With automatic exposure control, the increases in exposure after implant placement, represented as relative risk, were as follows: stomach, 1.000; pubic symphysis, 1.292; left pelvic wall, 1.476; sigmoid colon, 2.182; right pelvic wall, 3.000; and anterior pubic skin, 1.378. The amount of radiation to which patients are exposed as a result of medical procedures or imaging, and whether exposure is associated with an increased risk of malignant transformation, are the subject of ongoing debate. We found that after insertion

The use of the ICRP principles for controlling risks from potential exposure

International Nuclear Information System (INIS)

Cunningham, R.; Gonzalez, A.J.

1991-01-01

Heretofore, ICRP recommendations for radiation protection mainly apply to radiation exposures that are expected to occur with near certainty during normal operation of radiation sources. It is anticipated that the new ICRP recommendations will deal more comprehensively with radiation safety by including consideration of exposure which might or might not occur, but for which a probability of occurrence can be assigned (potential exposure). This paper discusses issues and principles for a system of radiation safety which accommodates both radiation protection and nuclear safety standards and covers both normal and potential exposures. The principles are formulated by interpreting and extrapolating the principles of justification, optimization and dose limitation currently employed for normal exposure

Exposure of healthy subjects with emissions from a gas metal arc welding process: part 1--exposure technique and external exposure.

Science.gov (United States)

Brand, P; Havlicek, P; Steiners, M; Holzinger, K; Reisgen, U; Kraus, T; Gube, M

2013-01-01

Studies concerning welding fume-related adverse health effects in welders are hampered by the heterogeneity of workplace situations, resulting in complex and non-standardized exposure conditions. In order to carry out welding fume exposure studies under controlled and standardized conditions, the Aachen Workplace Simulation Laboratory was developed. This laboratory consists of an emission room, in which welding fume is produced, and an exposure room in which human subjects are exposed to these fumes. Both rooms are connected by a ventilation system which allows the welding fume concentration to be regulated. Particle mass concentration was measured with a TEOM microbalance and the particle number-size distribution using a Grimm SMPS device. In a study, which is the subject of this paper, it has been shown that welding fume concentration can easily be regulated between 1 and about 3 mg m(-3). The chosen concentration can be kept constant for more than 8 h. However, transport of the particles from the emission room into the exposure room leads to a change in particle size distribution, which is probably due to coagulation of the fraction of smallest particles. The Aachen Workplace Simulation Laboratory is suitable for controlled exposure studies with human subjects.

Overview, practical tips and potential pitfalls of using automatic exposure control in CT: Siemens care dose 4D

International Nuclear Information System (INIS)

Soederberg, Marcus

2016-01-01

Today, computed tomography (CT) systems routinely use automatic exposure control (AEC), which modulates the tube current. However, for optimal use, there are several aspects of an AEC system that need to be considered. The purpose of this study was to provide an overview of the Siemens CARE Dose 4D AEC system, discuss practical tips and demonstrate potential pitfalls. Two adult anthropomorphic phantoms were examined using two different Siemens CT systems. When optimising the CT radiation dose and image quality, the projection angle of the localiser, patient centring, protocol selection, scanning direction and the use of protective devices requires special attention. (authors)

Assessment and control of fetal exposure

International Nuclear Information System (INIS)

Harty, R.; Swinth, K.L.; Traub, R.J.

1991-10-01

The assessment and control of fetal exposure to radiation in the workplace is an issue that is complicated by both biological and political/social ramifications. As a result of the dramatic increase in the number of women employed as radiation workers during the past 10 years, many facilities using radioactive materials have instituted fetal protection programs with special requirements for female radiation workers. It is necessary, however, to ensure that any fetal protection program be developed in such a way as to be nondiscriminatory. A study has been initiated whose purpose is to balance the political/social and the biological ramifications associated with occupational protection of the developing embryo/fetus. Several considerations are involved in properly balancing these factors. These considerations include appropriate methods of declaring the pregnancy, training workers, controlling the dose to the embryo/fetus, measuring and calculating the dose to the embryo/fetus, and recording the pertinent information. Alternative strategies for handling these factors while ensuring maximum protection of the embryo/fetus and the rights and responsibilities of employees and employers are discussed

Age dependent systemic exposure to inhaled salbutamol

DEFF Research Database (Denmark)

Bønnelykke, Klaus; Jespersen, Jakob Jessing; Bisgaard, Hans

2007-01-01

AIMS: To determine the effect of age on systemic exposure to inhaled salbutamol in children. METHODS: Fifty-eight asthmatic children, aged 3-16 years, inhaled 400 microg of salbutamol from a pressurized metered dose inhaler with spacer. The 20 min serum profile was analyzed. RESULTS: Prescribing...

Phototimer for automatic control of x-ray exposure, PT-20A

Energy Technology Data Exchange (ETDEWEB)

Ohno, H; Itoh, K; Ogura, I; Yasuhara, H; Sugimoto, H [Toshiba Corp., Kawasaki, Kanagawa (Japan)

1979-02-01

The phototimer as an exposure control device is now required to have higher accuracy and wider range of control to comply with the recent trends of x-ray diagnosis, such as toward short-time exposure due to increased output power of x-ray apparatus and toward one-man operation. In order to meet the requirement, the x-ray characteristics of the components of the phototimer have been examined, and computer simulation of x-ray spectra and dynamic characteristics of every component have been investigated, in pursuit of the essential characters of phototimers. On the basis of these analytical investigations, the phototimer PT-20A is so designed as to compensate for density deviation under various kVp and object thickness: uniform density has been obtained under practical radiographic conditions.

Analysis of Phone Calls Regarding Fluoride Exposure made to New Jersey Poison Control Center from 2010 to 2012.

Science.gov (United States)

Shah, Sneha; Quek, Samuel; Ruck, Bruce

2016-02-01

The American Association of Poison Control Center's annual reports demonstrate that acute fluoride exposure is not an uncommon occurrence. Despite its prevalence, there has been little published research on the topic in the last 10 years. The purpose of this study was to calculate the incidence of acute fluoride toxicity and lethality as it occurs in New Jersey and provide a descriptive epidemiology of acute fluoride exposures. The study design was retrospective in nature. Records of phone calls made by individuals reporting excessive fluoride exposure (in an amount greater than directed/prescribed) to New Jersey's poison control center, known as Poison Information and Education System from the years 2010 through 2012, were extracted from Toxicall® (Computer Automatic Systems, Inc.) database. A total of 2,476 human-only exposure records met the inclusion criteria and were analyzed. Incidence rates were calculated, and population characteristics, circumstances and medical outcomes of acute fluoride exposure cases were assessed and categorized. A total of 2,476 phone call records met the inclusion criteria. The fluoride exposures reported were from toothpaste with fluoride (49%, n=1,214), mouth rinse with fluoride (21.6%, n=536), multivitamin with fluoride (21.4%, n=530) and pure fluoride (0.08%, n=199). Medically speaking, 94.75% of calls were asymptomatic cases (n=2,346), 4.24% were symptomatic (n=105) and 1.01% were informational inquiries (n=25). Adverse symptoms reported were mostly minor (83.9% of symptomatic cases, n=88) and moderate (16.1% of symptomatic cases, n=17). The age group 18 months to 3 years of age showed the highest incidence of acute fluoride exposure (53.2%, n=1,317). There was a slightly higher incidence of acute fluoride exposures among males (n=1,317) vs. females (n=1,159). Most incidences occurred in the home (93.1% of records, n=2,305) and occurred unintentionally (96.7%, n=2,394). Calls were mainly made by the subject's mother (67.5%, n=1

Supervisory control for a complex robotic system

International Nuclear Information System (INIS)

Miller, D.J.

1988-01-01

The Robotic Radiation Survey and Analysis System investigates the use of advanced robotic technology for performing remote radiation surveys on nuclear waste shipping casks. Robotic systems have the potential for reducing personnel exposure to radiation and providing fast reliable throughput at future repository sites. A primary technology issue is the integrated control of distributed specialized hardware through a modular supervisory software system. Automated programming of robot trajectories based upon mathematical models of the cask and robot coupled with sensory feedback enables flexible operation of a commercial gantry robot with the reliability needed to perform autonomous operations in a hazardous environment. Complexity is managed using structured software engineering techniques resulting in the generation of reusable command primitives which contribute to a software parts catalog for a generalized robot programming language

Effects of prenatal substance exposure on neurocognitive correlates of inhibitory control success and failure.

Science.gov (United States)

Roos, Leslie E; Beauchamp, Kathryn G; Pears, Katherine C; Fisher, Philip A; Berkman, Elliot T; Capaldi, Deborah

2017-01-01

Adolescents with prenatal substance (drug and alcohol) exposure exhibit inhibitory control (IC) deficits and aberrations in associated neural function. Nearly all research to date examines exposure to individual substances, and a minimal amount is known about the effects of heterogeneous exposure-which is more representative of population exposure levels. Using functional magnetic resonance imaging (fMRI), we investigated IC (Go/NoGo) in heterogeneously exposed (n = 7) vs. control (n = 7) at-risk adolescents (ages 13-17). The fMRI results indicated multiple IC processing differences consistent with a more immature developmental profile for exposed adolescents (Exposed  >  Nonexposed: NoGo > Go: right ventrolateral prefrontal cortex, right cuneus, and left inferior parietal lobe; NoGo > false alarm: occipital lobe; Go > false alarm: right anterior prefrontal cortex). Simple effects suggest exposed adolescents exhibited exaggerated correct trial but decreased incorrect trial activation. Results provide initial evidence that prenatal exposure across substances creates similar patterns of atypical brain activation to IC success and failure.

Contribution of job-exposure matrices for exposure assessment in occupational safety and health monitoring systems: application from the French national occupational disease surveillance and prevention network.

Science.gov (United States)

Florentin, Arnaud; Zmirou-Navier, Denis; Paris, Christophe

2017-08-01

To detect new hazards ("signals"), occupational health monitoring systems mostly rest on the description of exposures in the jobs held and on reports by medical doctors; these are subject to declarative bias. Our study aims to assess whether job-exposure matrices (JEMs) could be useful tools for signal detection by improving exposure reporting. Using the French national occupational disease surveillance and prevention network (RNV3P) data from 2001 to 2011, we explored the associations between disease and exposure prevalence for 3 well-known pathology/exposure couples and for one debatable couple. We compared the associations measured when using physicians' reports or applying the JEMs, respectively, for these selected diseases and across non-selected RNV3P population or for cases with musculoskeletal disorders, used as two reference groups; the ratio of exposure prevalences according to the two sources of information were computed for each disease category. Our population contained 58,188 subjects referred with pathologies related to work. Mean age at diagnosis was 45.8 years (95% CI 45.7; 45.9), and 57.2% were men. For experts, exposure ratios increase with knowledge on exposure causality. As expected, JEMs retrieved more exposed cases than experts (exposure ratios between 12 and 194), except for the couple silica/silicosis, but not for the MSD control group (ratio between 0.2 and 0.8). JEMs enhanced the number of exposures possibly linked with some conditions, compared to experts' assessment, relative to the whole database or to a reference group; they are less likely to suffer from declarative bias than reports by occupational health professionals.

Investigation of uniformity field generated from freeform lens with UV LED exposure system

Science.gov (United States)

Ciou, F. Y.; Chen, Y. C.; Pan, C. T.; Lin, P. H.; Lin, P. H.; Hsu, F. T.

2015-03-01

In the exposure process, the intensity and uniformity of light in the exposure area directly influenced the precision of products. UV-LED (Ultraviolet Light-Emitting Diode) exposure system was established to reduce the radiation leakage and increase the energy efficiency for energy saving. It is a trend that conventional mercury lamp could be replaced with UV-LED exposure system. This study was based on the law of conservation of energy and law of refraction of optical field distributing on the target plane. With these, a freeform lens with uniform light field of main exposure area could be designed. The light outside the exposure area could be concentrated into the area to improve the intensity of light. The refraction index and UV transmittance of Polydimethylsiloxane (PDMS) is 1.43 at 385 nm wavelength and 85-90%, respectively. The PDMS was used to fabricate the optics lens for UV-LEDs. The average illumination and the uniformity could be obtained by increasing the number of UV-LEDs and the spacing of different arrangement modes. After exposure process with PDMS lens, about 5% inaccuracy was obtained. Comparing to 10% inaccuracy of general exposure system, it shows that it is available to replace conventional exposure lamp with using UV-LEDs.

Application of a pilot control banding tool for risk level assessment and control of nanoparticle exposures.

Science.gov (United States)

Paik, Samuel Y; Zalk, David M; Swuste, Paul

2008-08-01

Control banding (CB) strategies offer simplified solutions for controlling worker exposures to constituents that are found in the workplace in the absence of firm toxicological and exposure data. These strategies may be particularly useful in nanotechnology applications, considering the overwhelming level of uncertainty over what nanomaterials and nanotechnologies present as potential work-related health risks, what about these materials might lead to adverse toxicological activity, how risk related to these might be assessed and how to manage these issues in the absence of this information. This study introduces a pilot CB tool or 'CB Nanotool' that was developed specifically for characterizing the health aspects of working with engineered nanoparticles and determining the level of risk and associated controls for five ongoing nanotechnology-related operations being conducted at two Department of Energy research laboratories. Based on the application of the CB Nanotool, four of the five operations evaluated in this study were found to have implemented controls consistent with what was recommended by the CB Nanotool, with one operation even exceeding the required controls for that activity. The one remaining operation was determined to require an upgrade in controls. By developing this dynamic CB Nanotool within the realm of the scientific information available, this application of CB appears to be a useful approach for assessing the risk of nanomaterial operations, providing recommendations for appropriate engineering controls and facilitating the allocation of resources to the activities that most need them.

Short-term exposure to mobile phone base station signals does not affect cognitive functioning or physiological measures in individuals who report sensitivity to electromagnetic fields and controls.

Science.gov (United States)

Eltiti, Stacy; Wallace, Denise; Ridgewell, Anna; Zougkou, Konstantina; Russo, Riccardo; Sepulveda, Francisco; Fox, Elaine

2009-10-01

Individuals who report sensitivity to electromagnetic fields often report cognitive impairments that they believe are due to exposure to mobile phone technology. Previous research in this area has revealed mixed results, however, with the majority of research only testing control individuals. Two studies using control and self-reported sensitive participants found inconsistent effects of mobile phone base stations on cognitive functioning. The aim of the present study was to clarify whether short-term (50 min) exposure at 10 mW/m(2) to typical Global System for Mobile Communication (GSM) and Universal Mobile Telecommunications System (UMTS) base station signals affects attention, memory, and physiological endpoints in sensitive and control participants. Data from 44 sensitive and 44 matched-control participants who performed the digit symbol substitution task (DSST), digit span task (DS), and a mental arithmetic task (MA), while being exposed to GSM, UMTS, and sham signals under double-blind conditions were analyzed. Overall, cognitive functioning was not affected by short-term exposure to either GSM or UMTS signals in the current study. Nor did exposure affect the physiological measurements of blood volume pulse (BVP), heart rate (HR), and skin conductance (SC) that were taken while participants performed the cognitive tasks.

Residential traffic noise exposure and vestibular schwannoma - a Danish case-control study.

Science.gov (United States)

Roswall, Nina; Stangerup, Sven-Eric; Cayé-Thomasen, Per; Schüz, Joachim; Johansen, Christoffer; Jensen, Steen Solvang; Raaschou-Nielsen, Ole; Sørensen, Mette

2017-10-01

Few risk factors for sporadic vestibular schwannoma (VS) are known. Several studies have proposed an increased risk with occupational noise exposure, whereas no studies have investigated residential traffic noise exposure as a risk factor. The present study investigated if residential traffic noise was associated with vestibular schwannoma in a large, population-based Danish case-control study. We identified 1454 VS cases, age above 30 years at diagnosis, between 1990 and 2007. For each case, we selected two random population controls, matched on sex and year of birth. Road and railway traffic noise at the residence was calculated for all present and historical addresses between 1987 and index date. Associations between traffic noise and risk for VS were estimated using conditional logistic regression, adjusted for education, disposable personal income, cohabitation status, railway noise exposure, municipal population density, and municipal income. A two-year time-weighted mean road traffic noise exposure was associated with an adjusted odds ratio of 0.92 (0.82-1.03) for developing VS, per 10 dB increment. There was no clear trend in categorical analyses. Similarly, linear and categorical analyses of residential railway noise did not suggest an association. We found no interaction with demographics, year of diagnosis, individual and municipal socioeconomic variables, and railway noise exposure. The results did not differ by tumor side, spread or size. The present study does not suggest an association between residential traffic noise and VS.

Development and demonstration of techniques for reducing occupational radiation doses during refueling outages. Tasks 7A/7B. Advanced outage management and radiation exposure control

International Nuclear Information System (INIS)

1985-03-01

Objectives of Tasks 7A and 7B were to develop and demonstrate computer based systems to assist plant management and staff in utilizing information more effectively to reduce occupational exposures received as a result of refueling outages, and to shorten the duration of the outage. The Advanced Outage Management (AOM) Tool (Task 7A) is an automated outage planning system specifically designed to meet the needs of nuclear plant outage management. The primary objective of the AOM tool is to provide a computerized system that can manipulate the information typically associated with outage planning and scheduling to furnish reports and schedules that more accurately project the future course of the outage. The Radiation Exposure Control (REC) Tool (Task 7B) is a computerized personnel radiation exposure accounting and management system designed to enable nuclear plant management to project and monitor total personnel radiation exposure on a real-time basis. The two systems were designed to operate on the same computer system and interface through a common database that enables information sharing between plant organizations not typically interfaced. This interfacing provides outage planners with a means of incorporating occupational radiation exposure as a factor for making decisions on the course of an outage

Nighttime dim light exposure alters the responses of the circadian system.

Science.gov (United States)

Shuboni, D; Yan, L

2010-11-10

The daily light dark cycle is the most salient entraining factor for the circadian system. However, in modern society, darkness at night is vanishing as light pollution steadily increases. The impact of brighter nights on wild life ecology and human physiology is just now being recognized. In the present study, we tested the possible detrimental effects of dim light exposure on the regulation of circadian rhythms, using CD1 mice housed in light/dim light (LdimL, 300 lux:20 lux) or light/dark (LD, 300 lux:1 lux) conditions. We first examined the expression of clock genes in the suprachiasmatic nucleus (SCN), the locus of the principal brain clock, in the animals of the LD and LdimL groups. Under the entrained condition, there was no difference in PER1 peak expression between the two groups, but at the trough of the PER 1 rhythm, there was an increase in PER1 in the LdimL group, indicating a decrease in the amplitude of the PER1 rhythm. After a brief light exposure (30 min, 300 lux) at night, the light-induced expression of mPer1 and mPer2 genes was attenuated in the SCN of LdimL group. Next, we examined the behavioral rhythms by monitoring wheel-running activity to determine whether the altered responses in the SCN of LdimL group have behavioral consequence. Compared to the LD controls, the LdimL group showed increased daytime activity. After being released into constant darkness, the LdimL group displayed shorter free-running periods. Furthermore, following the light exposure, the phase shifting responses were smaller in the LdimL group. The results indicate that nighttime dim light exposure can cause functional changes of the circadian system, and suggest that altered circadian function could be one of the mechanisms underlying the adverse effects of light pollution on wild life ecology and human physiology. Copyright © 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

Exposure to pistachio pesticides and stillbirth: a case-control study.

Science.gov (United States)

Razi, Saeid; Rezaeian, Mohsen; Dehkordi, Fatemeh Ghani; Manshoori, Azita; Goujani, Reza; Vazirinejad, Reza

2016-01-01

Stillbirth is an undesirable outcome of pregnancy. In light of the increasing use of pesticides and growing concerns about the possible health effects of agricultural pesticides, we investigated the effect of exposure to pistachio pesticides on stillbirth in pregnant mothers. This case-control study was conducted in Rafsanjan, Iran from 2011 to 2012. A total of 125 females who had a recent stillbirth were included as the case group, and 250 controls were selected from females who had a recent live birth. For each case, two controls with the nearest propensity score to the case were selected. Data were collected using a protocol developed by the researcher that involved interviewing respondents and reviewing their medical records. Conditional multivariate and univariate logistic regression analysis were performed and odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. The ORs of stillbirth in mothers living in pistachio gardens and those who were exposed to sprayed pesticides, in comparison to the controls, were 14.1 (95% CI, 3.3 to 63.4) and 5.0 (95% CI, 1.2 to 28.6), respectively. No significant differences were found in stillbirth rates according to the distance between the mother's residence and a pistachio garden or involvement in agricultural activities. The results of our study showed that exposure to pistachio pesticides during pregnancy may increase the likelihood of stillbirth in mothers.

A Comparison of Item Selection Techniques and Exposure Control Mechanisms in CATs Using the Generalized Partial Credit Model.

Science.gov (United States)

Pastor, Dena A.; Dodd, Barbara G.; Chang, Hua-Hua

2002-01-01

Studied the impact of using five different exposure control algorithms in two sizes of item pool calibrated using the generalized partial credit model. Simulation results show that the a-stratified design, in comparison to a no-exposure control condition, could be used to reduce item exposure and overlap and increase pool use, while degrading…

Individual external exposures from Nevada Test Site fallout for Utah leukemia cases and controls

International Nuclear Information System (INIS)

Lloyd, R.D.; Gren, D.C.; Simon, S.L.; Wrenn, M.E.; Hawthorne, H.A.; Lotz, T.M.; Stevens, W.; Till, J.E.

1990-01-01

External gamma-ray exposures from fallout originating at the Nevada Test Site (NTS) have been assigned to 6,507 individual subjects (1,177 leukemia cases and 5,330 control subjects) who died as Utah residents between 1952 and 1981. Leukemia cases were identified, confirmed, and classified by cell type from the Utah Cancer Registry, Utah State vital records, and medical records. Residential histories were obtained from the Deceased Membership File (DMF) of the Church of Jesus Christ of Latter-day Saints (LDS), supplemented by information from the LDS Church Census Records that were taken in 1950, 1955, and 1960-62. Control subjects were selected randomly within age strata from the DMF and were frequency-matched to the cases by age at death and for sex. Individual radiation exposures were assigned as a function of residence location and time interval for each residence during the fallout period (1951-1958) using geographic exposure data taken from the literature. Temporal distribution of exposure for subjects who resided in more than one locality or who were born or died during the fallout period was determined from data of other investigators. Calculated gamma-ray exposures for each place of residence were summed for each subject to yield the exposure to fallout from the NTS

Systemic serum amyloid A as a biomarker for exposure to zinc and/or copper-containing metal fumes.

Science.gov (United States)

Baumann, R; Gube, M; Markert, A; Davatgarbenam, S; Kossack, V; Gerhards, B; Kraus, T; Brand, P

2018-01-01

Zinc- and copper-containing welding fumes increase systemic C-reactive protein (CRP). The aim of this study was to investigate the performance of the biomarkers serum amyloid A (SAA) and soluble vascular cell adhesion molecule-1 (VCAM-1) in this regard. Fifteen male subjects were exposed under controlled conditions to welding fumes containing either zinc, or copper, or copper and zinc for 6 h. Plasma samples were collected before, 6 and 24 h after start of exposure and biomarkers therein were measured by electrochemiluminescent assay. For each exposure, systemic concentrations of systemic SAA, but not VCAM-1, increased significantly at 24 h after exposure start compared with baseline ("copper only": P=0.0005, "zinc only": P=0.027, "copper and zinc": P=0.001). SAA showed a wider range of concentrations than did CRP and its levels increased up to 19-fold after welding fume exposure. The recognition of copper as a potential harmful component in welding fumes, also independent from zinc, deserves further consideration. SAA might represent a new sensitive biomarker for potential subclinical sterile inflammation after inhalation of copper- and/or zinc-containing welding fumes. As elevations of CRP and SAA protein have both been linked to a higher risk for cardiovascular disease, these findings might particularly be important for long-term welders.

Analysis of Cigarette Smoke Deposition Within an In Vitro Exposure System for Simulating Exposure in the Human Respiratory Tract

Directory of Open Access Journals (Sweden)

Ishikawa Shinkichi

2016-01-01

Full Text Available For the risk assessment of airborne chemicals, a variety of in vitro direct exposure systems have been developed to replicate airborne chemical exposure in vivo. Since cells at the air-liquid interface are exposed to cigarette smoke as an aerosol in direct exposure systems, it is possible to reproduce the situation of cigarette smoke exposure in the human respiratory system using this device. However it is difficult to know whether the exposed cigarette smoke in this system is consistent with the smoke retained in the human respiratory tract. The purpose of this study is to clarify this point using the CULTEX® RFS module which is a recently developed direct exposure system. For this purpose, solanesol and acetaldehyde were respectively chosen as the particulate and gas/vapor phase representatives of smoke constituents, and their deposition and balance per unit area of cell culture surface of the RFS module were measured (dosimetry. We also conducted human retention studies to compare with the dosimetry data. By comparing inhaled smoke and exhaled smoke under three inhalation conditions, we estimated the regional retention and balance of each representative per unit surface area of the respiratory tract (mouth, bronchi, and alveoli separately. The deposition of solanesol and acetaldehyde per unit area of cell culture surface in the RFS module decreased dependent on the dilution flow rate and ranged from 0.26-0.0076%/cm2 in our experimental conditions. The ratio of deposited acetaldehyde to deposited solanesol ranged from 0.96-1.96 in the RFS module. The retention of solanesol and acetaldehyde per unit surface area in the mouth and the bronchi ranged from 0.095-0.0083%/cm2 in this study. The retention per unit surface area of alveoli was far lower than in the other two regions (0.0000063%/cm2. The ratio of retained acetaldehyde to retained solanesol ranged from 0.54-1.97. From these results, we concluded that the CULTEX® RFS module can simulate

Modernization of control system using the digital control system

International Nuclear Information System (INIS)

Carrasco, J. A.; Fernandez, L.; Jimenez, A.

2002-01-01

Nowadays, all plant automation tendencies are based on the use of Digital Control System. In big industrial plants the control systems employed are Distributed Control Systems (DCS). The addition of these systems in nuclear power plants,implies an important adaptation process, because most of them were installed using analog control systems. This paper presents the objectives and the first results obtained, in a modernization project, focused in obtaining an engineering platform for making test and analysis of changes prior to their implementation in a nuclear plant. Modernization, Upgrade, DCS, Automation, Simulation, Training. (Author)

Changes in rat respiratory system produced by exposure to exhaust gases of combustion of glycerol.

Science.gov (United States)

Serra, Daniel Silveira; Evangelista, Janaína Serra Azul Monteiro; Zin, Walter Araujo; Leal-Cardoso, José Henrique; Cavalcante, Francisco Sales Ávila

2017-08-01

The combustion of residual glycerol to generate heat in industrial processes has been suggested as a cost-effective solution for disposal of this environmental liability. Thus, we investigated the effects of exposure to the exhaust gases of glycerol combustion in the rat respiratory system. We used 2 rats groups, one exposed to the exhaust gases from glycerol combustion (Glycerol), and the other exposed to ambient air (Control). Exposure occurred 5h a day, 5days a week for 13 weeks. We observed statistically changes in all parameters of respiratory system mechanics in vivo. This results was supported by histological analysis and morphometric data, confirming narrower airways and lung parenchimal changes. Variables related to airway resistance (ΔR N ) and elastic properties of the tissue (ΔH), increased after challenge with methacholine. Finally, analysis of lung tissue micromechanics showed statistically increases in all parameters (R, E and hysteresivity). In conclusion, exhaust gases from glycerol combustion were harmful to the respiratory system. Copyright © 2017 Elsevier B.V. All rights reserved.

Neospora caninum versus Brucella spp. exposure among dairy cattle in Ethiopia: a case control study.

Science.gov (United States)

Asmare, Kassahun

2014-08-01

This case-control study aimed at assessing the relative association of Neospora caninum and Brucella species exposure with reproductive disorders. The study was carried out between October 2011 and June 2012 on 731 dairy cows sampled from 150 dairy farms in selected 17 conurbations of Ethiopia. Two hundred sixty-six of the cows were categorized as cases based on their history of abortion or stillbirth while the remaining 465 were controls. The presence of antibody to N. caninum was screened using indirect ELISA, while Brucella spp. exposure was assayed serially using Rose Bengal Plate Test and Complement Fixation Test. Exposure to N. caninum was more frequently observed among cases (23.8%) than controls (12.7%), while no significant difference (p > 0.05) was noted for Brucella exposure between the two groups. Moreover, the proportion of cows with disorders like retention of fetal membrane, endometritis and increased inter-calving period were significantly higher (p Brucella spp. exposure. However, neither N. caninum nor Brucella spp. could explain the majority (73.2%) of the reported abortions and stillbirths in cattle. Hence, this observation underscores the need for more intensive investigation on the identification of causes of the aforementioned disorders in dairy cattle of Ethiopia.

Virtual reality exposure therapy for social anxiety disorder: a randomized controlled trial.

Science.gov (United States)

Anderson, Page L; Price, Matthew; Edwards, Shannan M; Obasaju, Mayowa A; Schmertz, Stefan K; Zimand, Elana; Calamaras, Martha R

2013-10-01

This is the first randomized trial comparing virtual reality exposure therapy to in vivo exposure for social anxiety disorder. Participants with a principal diagnosis of social anxiety disorder who identified public speaking as their primary fear (N = 97) were recruited from the community, resulting in an ethnically diverse sample (M age = 39 years) of mostly women (62%). Participants were randomly assigned to and completed 8 sessions of manualized virtual reality exposure therapy, exposure group therapy, or wait list. Standardized self-report measures were collected at pretreatment, posttreatment, and 12-month follow-up, and process measures were collected during treatment. A standardized speech task was delivered at pre- and posttreatment, and diagnostic status was reassessed at 3-month follow-up. Analysis of covariance showed that, relative to wait list, people completing either active treatment significantly improved on all but one measure (length of speech for exposure group therapy and self-reported fear of negative evaluation for virtual reality exposure therapy). At 12-month follow-up, people showed significant improvement from pretreatment on all measures. There were no differences between the active treatments on any process or outcome measure at any time, nor differences on achieving partial or full remission. Virtual reality exposure therapy is effective for treating social fears, and improvement is maintained for 1 year. Virtual reality exposure therapy is equally effective as exposure group therapy; further research with a larger sample is needed, however, to better control and statistically test differences between the treatments.

Case-control study of congenital malformations and occupational exposure to low-level ionizing radiation

International Nuclear Information System (INIS)

Sever, L.E.; Gilbert, E.S.; Hessol, N.A.; McIntyre, J.M.

1988-01-01

In a case-control study, the authors investigated the association of parental occupational exposure to low-level external whole-body penetrating ionizing radiation and risk of congenital malformations in their offspring. Cases and controls were ascertained from births in two counties in southeastern Washington State, where the Hanford Site has been a major employer. A unique feature of this study was the linking of quantitative individual measurement of external whole-body penetrating ionizing radiation exposure of employees at the Hanford Site, using personal dosimeters, and the disease outcome, congenital malformations. The study population included 672 malformation cases and 977 matched controls from births occurring from 1957 through 1980. Twelve specific malformation types were analyzed for evidence of association with employment of the parents at Hanford and with occupational exposure to ionizing radiation. Two defects, congenital dislocation of the hip and tracheoesophageal fistula, showed statistically significant associations with employment of the parents at Hanford, but not with parental radiation exposure. Neural tube defects showed a significant association with parental preconception exposure, on the basis of a small number of cases. Eleven other defects, including Down syndrome, for which an association with radiation was considered most likely, showed no evidence of such an association. When all malformations were analyzed as a group, there was no evidence of an association with employment of the parents at Hanford, but the relation of parental exposure to radiation before conception was in the positive direction (one-tailed p value between 0.05 and 0.10). Given the number of statistical tests conducted, some or all of the observed positive correlations are likely to represent false positive findings. 30 references

Hormesis of Low Doses of Ionizing Radiation Exposure on Immune System

International Nuclear Information System (INIS)

Ragab, M.H.; Abbas, M.O.; El-Asady, R.S.; Amer, H.A.; El-Khouly, W.A.; Shabon, M.H.

2015-01-01

The effect of low doses of ionizing radiation on the immune system has been a controversial subject. To evaluate the effect of low-doses γ-irradiation exposure on immune system. An animal model, using Rattus Rattus rats was used. The rats were divided into groups exposed to either continuous or fractionated 100, 200, 300, 400 and 500 mSv of radiation and compared to control rats that did not receive radiation. All groups were exposed to a total white blood count (Wcs), lymphocyte count and serum IgG level measurement, as indicators of the function of the cell-mediated (T lymphocytes) and the humoral (B lymphocytes) immune system. The results of the current study revealed that the counts of total leukocytes (WBCs) and lymphocytes, as well as the serum level of IgG were increased significantly in rats receiving low dose radiation, indicating enhancement of immune system. The data suggests that low-dose gamma-radiation improved hematological parameters and significantly enhances immune response indices of the exposed rats. These findings are similar to the radiation adaptive responses in which a small dose of pre irradiation would induce certain radiation resistance and enhances the cell response after exposure to further irradiation doses The applied low doses used in the present study may appear effective inducing the radio adaptive response. Farooqi and Kesavan (1993) and Bravard et al. (1999) reported that the adaptive response to ionizing radiation refers to the phenomenon by which cells irradiated with low (cGy) or sublethal doses (conditioning doses) become less susceptible to genotoxic effects of a subsequent high dose (challenge dose, several Gy).

Effects of Long-Term Dust Exposure on Human Respiratory System Health in Minqin County, China.

Science.gov (United States)

Wang, Jinyu; Li, Sheng; Wang, Shigong; Shang, Kezheng

2015-01-01

The aim of this study was to assess the effects of long-term sand dust exposure on human respiratory health. Dust events break out frequently in Minqin County, northwest China, whereas Pingliang City, northwest China, is rarely influenced by dust events. Therefore, Minqin and Pingliang were selected as sand dust exposure region and control area, respectively. The incidence of respiratory system diseases and symptoms was determined through a structured respiratory health questionnaire (ATS-DLD-78-A) and personal interviews. The subjects comprised 728 farmers (Minqin, 424; Pingliang, 304) aged 40 years or older, who had nondocumented occupational history to industrial dust exposure. Prevalences (odds ratio [OR], 95% confidence interval [CI]) of chronic rhinitis, chronic bronchitis, and chronic cough increased 9.6% (3.141, 1.776-5.555), 7.5% (2.468, 1.421-4.286), and 10.2% (1.787, 1.246-2.563) in Minqin comparison with Pingliang, respectively, and the differences were significant (p <.01).

Prenatal Alcohol Exposure and the Developing Immune System

OpenAIRE

Gauthier, Theresa W.

2015-01-01

Evidence from research in humans and animals suggest that ingesting alcohol during pregnancy can disrupt the fetal immune system and result in an increased risk of infections and disease in newborns that may persist throughout life. Alcohol may have indirect effects on the immune system by increasing the risk of premature birth, which itself is a risk factor for immune-related problems. Animal studies suggest that alcohol exposure directly disrupts the developing immune system. A comprehensiv...

Isoe - information system on occupational exposure. Ten years of experience

International Nuclear Information System (INIS)

2002-01-01

The information System on Occupational Exposure (ISOE) was created in 1992 to provide a forum for radiation protection experts from both utilities and national regulatory authorities to discuss, promote and co-ordinate international co-operative undertakings in the area of worker protection at nuclear power plants. The ISOE System is jointly managed by the OECD Nuclear Energy Agency (NEA) and the International Atomic Energy Agency (IAEA). This report provides an overview of the experience gained from, and benefits provided by, the ISOE System over the past ten years. Active participation of a large number of utilities in ISOE has contributed to a reduction in occupational exposure at nuclear power plants worldwide. (authors)

Controlling criteria for radiation exposure of astronauts and space workers

International Nuclear Information System (INIS)

Katoh, Kazuaki

1989-01-01

Space workers likely to suffer from radiation exposure in the outer space are currently limited to the U.S. and Soviet Union, and only a small amount of data and information is available concerning the techniques and criteria for control of radiation exposure in this field. Criteria used in the Soviet Union are described first. The criteria (TRS-75), called the Radiation Safety Criteria for Space Navigation, are tentative ones set up in 1975. They are based on risk assessment. The standard radiation levels are established based on unit flight time: 50rem for 1 month, 80rem for 3 months, 110rem for 6 months and 150rem for 12 months. These are largely different from the emergency exposure limit of 100mSv (10rem) specified in a Japanese law, and the standard annual exposure value of 50mSv (5rem) for workers in nuclear power plants at normal times. For the U.S., J.A. Angelo, Jr., presented a paper titled 'Radiation Protection Issues and Techniques concerning Extended Manned Space Missions' at an IAEA meeting held in 1988. Though the criteria shown in the paper are not formal ones at the national level, similar criteria are expected to be adopted by the nation in the near future. The exposure limits recommended in the paper include a depth dose of 1-4Sv for the whole life span of a worker. (Nogami, K.)

Radiation exposure monitoring and control in front-end fuel cycle facilities

International Nuclear Information System (INIS)

Khan, A.H.

2003-01-01

The front end nuclear fuel cycle facilities presently operational in India are the mining and processing of beach mineral sands along the southern coast of Kerala, Tamilnadu and Orissa, mining and processing of uranium ore in Singhbhum-East in Jharkhand and refining and fuel fabrication at Hyderabad and Trombay. Dedicated Health Physics Units set up at each site regularly carry out in-plant and personnel monitoring to ensure safe working conditions and evaluate radiation exposure of workers and advise appropriate control measures. External gamma radiation, radon, thoron, their progeny and airborne long-lived activity due to radioactive dust are monitored. Personal dosimeters are also issued to workers. The total radiation exposure of workers from external and internal sources is evaluated from the plant and personal monitoring data. Provision of adequate ventilation, control of dust and spillage of active solutions, prompt decontamination, use of personal protective appliances and worker education are the key factors in keeping the doses to the workers well within the regulatory limits. It has been observed that the total radiation dose to workers has been well below 20 mSv.y - 1 at all stages of operations. The monitoring methodologies and summary of radiation exposure data for different facilities during the last few years are presented in the paper. (author)

Radon exposure and tumors of the central nervous system.

Science.gov (United States)

Ruano-Ravina, Alberto; Dacosta-Urbieta, Ana; Barros-Dios, Juan Miguel; Kelsey, Karl T

2017-03-15

To review the published evidence of links between radon exposure and central nervous system tumors through a systematic review of the scientific literature. We performed a thorough bibliographic search in Medline (PubMed) and EMBASE. We combined MeSH (Medical Subject Heading) terms and free text. We developed a purpose-designed scale to assess the quality of the included manuscripts. We have included 18 studies, 8 performed on miners, 3 on the general population and 7 on children, and the results have been structured using this classification. The results are inconclusive. An association between radon exposure and central nervous system tumors has been observed in some studies on miners, but not in others. The results observed in the general adult population and in children are also mixed, with some research evincing a statistically significant association and others showing no effect. We cannot conclude that there is a relationship between radon exposure and central nervous system tumors. The available studies are extremely heterogeneous in terms of design and populations studied. Further research is needed in this topic, particularly in the general population residing in areas with high levels of radon. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Exposure to pistachio pesticides and stillbirth: a case-control study

Directory of Open Access Journals (Sweden)

Saeid Razi

2016-04-01

Full Text Available OBJECTIVES Stillbirth is an undesirable outcome of pregnancy. In light of the increasing use of pesticides and growing concerns about the possible health effects of agricultural pesticides, we investigated the effect of exposure to pistachio pesticides on stillbirth in pregnant mothers. METHODS This case-control study was conducted in Rafsanjan, Iran from 2011 to 2012. A total of 125 females who had a recent stillbirth were included as the case group, and 250 controls were selected from females who had a recent live birth. For each case, two controls with the nearest propensity score to the case were selected. Data were collected using a protocol developed by the researcher that involved interviewing respondents and reviewing their medical records. Conditional multivariate and univariate logistic regression analysis were performed and odds ratios (ORs and 95% confidence intervals (CIs were calculated. RESULTS The ORs of stillbirth in mothers living in pistachio gardens and those who were exposed to sprayed pesticides, in comparison to the controls, were 14.1 (95% CI, 3.3 to 63.4 and 5.0 (95% CI, 1.2 to 28.6, respectively. No significant differences were found in stillbirth rates according to the distance between the mother’s residence and a pistachio garden or involvement in agricultural activities. CONCLUSIONS The results of our study showed that exposure to pistachio pesticides during pregnancy may increase the likelihood of stillbirth in mothers.

Exposure control practices for administering nitrous oxide: A survey of dentists, dental hygienists, and dental assistants.

Science.gov (United States)

Boiano, James M; Steege, Andrea L; Sweeney, Marie H

2017-06-01

Engineering, administrative, and work practice controls have been recommended for many years to minimize exposure to nitrous oxide during dental procedures. To better understand the extent to which these exposure controls are used, the NIOSH Health and Safety Practices Survey of Healthcare Workers was conducted among members of professional practice organizations representing dentists, dental hygienists and dental assistants. The anonymous, modular, web-based survey was completed by 284 dental professionals in private practice who administered nitrous oxide to adult and/or pediatric patients in the seven days prior to the survey. Use of primary engineering controls (i.e., nasal scavenging mask and/or local exhaust ventilation (LEV) near the patient's mouth) was nearly universal, reported by 93% and 96% of respondents who administered to adult (A) and pediatric (P) patients, respectively. However, adherence to other recommended precautionary practices were lacking to varying degrees, and were essentially no different among those administering nitrous oxide to adult or pediatric patients. Examples of work practices which increase exposure risk, expressed as percent of respondents, included: not checking nitrous oxide equipment for leaks (41% A; 48% P); starting nitrous oxide gas flow before delivery mask or airway mask was applied to patient (13% A; 12% P); and not turning off nitrous oxide gas flow before turning off oxygen flow to the patient (8% A; 7% P). Absence of standard procedures to minimize worker exposure to nitrous oxide (13% of all respondents) and not being trained on safe handling and administration of nitrous oxide (3%) were examples of breaches of administrative controls which may also increase exposure risk. Successful management of nitrous oxide emissions should include properly fitted nasal scavenging masks, supplemental LEV (when nitrous oxide levels cannot be adequately controlled using nasal masks alone), adequate general ventilation, regular

Pesticide Exposure and Head and Neck Cancers: A Case-Control Study in an Agricultural Region

Directory of Open Access Journals (Sweden)

Maryam Amizadeh

2017-09-01

Full Text Available Introduction: Causes of head and neck cancers (HNCs are multifactorial, and few studies have investigated the association between chemical exposure and HNCs. The objective of this study was to investigate associations between HNCs, agricultural occupations, and pesticide exposure. The potential for the accumulation of pesticides in the adipose tissue of patients was also investigated.   Materials and Methods: A structured questionnaire was used to collect information on demographics, occupation, and exposure to pesticides in a hospital-based case-control study. Pesticide residue in the adipose tissue of the neck in both cases and controls was also monitored via gas chromatography–mass spectroscopy.   Results: Thirty-one HNC cases were included in this study as well as 32 gender-, age-, and smoking-matched controls. An agricultural occupation was associated with HNC (odds ratio [OR], 3.26; 95% confidence interval [CI], 1.13–9.43 after controlling for age, sex, and smoking. Pesticide exposure was associated with total HNC cases (OR, 7.45; 95% CI, 1.78–3.07 and larynx cancer (OR, 9.33; 95% CI, 1.65–52.68. A dose-response pattern was observed for HNC cases (P=0.06 and larynx cancer (P=0.01. In tracing the pesticide residue, five chlorinated pesticides, namely dichlorodiphenyltrichloroethane (DDT, dichlorodipheny-ldichloroethane (DDD, dichlorodiphenyldichloroethylene (DDE, dieldrin, and lindane, were identified in the adipose tissue. Chlorinated pesticide detection was significantly associated with HNC (OR, 3.91; 95% CI 0.9–0.16.9.   Conclusion: HNCs were found to be associated with pesticide exposure after controlling for confounders. A high education level was identified as a modifying factor decreasing the risk of HNCs. Further studies with larger number of subjects are recommended to assess these relationships in greater detail.

Trauma exposure is associated with increased context-dependent adjustments of cognitive control in patients with posttraumatic stress disorder and healthy controls.

Science.gov (United States)

Steudte-Schmiedgen, Susann; Stalder, Tobias; Kirschbaum, Clemens; Weber, Fanny; Hoyer, Jürgen; Plessow, Franziska

2014-12-01

Recent evidence has suggested that posttraumatic stress disorder (PTSD) is associated with alterations in prefrontal-cortex-dependent cognitive processes (e.g., working memory, cognitive control). However, it remains unclear whether these cognitive dysfunctions are related to PTSD symptomatology or trauma exposure. Furthermore, regarding cognitive control, research has only focused on the integrity of selected control functions, but not their dynamic regulation in response to changing environmental demands. Therefore, the present study investigated dynamic variations in interference control, in addition to overall interference susceptibility and working memory (WM) performance in matched groups of 24 PTSD patients and 26 traumatized and 30 nontraumatized healthy controls. The Simon task was used to measure overall interference susceptibility and the flexible adjustment of cognitive control, on the basis of the occurrence of response conflicts (conflict adaptation effect). WM performance was assessed with the forward and backward digit span tasks. Since we have previously shown that trauma exposure per se is associated with reduced hair cortisol concentrations (HCC), we further explored whether PTSD/trauma-related cognitive alterations are related to HCC in proximal 3-cm hair segments. The results revealed that PTSD patients and traumatized controls showed significantly more pronounced conflict adaptation effects than nontraumatized controls. Moreover, the conflict adaptation effect was positively related to the number of lifetime traumatic events and the frequency of traumatization. The groups did not differ in overall interference susceptibility or WM performance. Exploratory analyses revealed no association between HCC and the observed cognitive differences. These results suggest that context-driven control adjustments constitute a sensitive correlate of trauma exposure, irrespective of PTSD.

Correction of over and under exposure images using multiple lighting system

International Nuclear Information System (INIS)

Im, Jonghoon; Fujii, Hiromitsu; Yamashita, Atsushi; Asama, Hajime

2015-01-01

When images are acquired in bright condition, it can cause a loss of highlight details (over exposure) in bright area and a loss of shadow details (under exposure) in dark area. Over and under exposure causes a big problem when people investigate dangerous place like Fukushima nuclear power plant through the camera attached remote control robot. In this paper, we propose a method to correct the over and under exposure image to solve the problem. The image processing consists of four steps. Firstly, multiple images are acquired by alternately turning on and off each illumination which set in different positions. Then the image obtained first is defined as input image 1, the image obtained second is defined as input image 2 and the image obtained N-th is defined as input image N. Secondly, luminance of the images is corrected. Thirdly, over and under exposure regions in the image are extracted from the input image 1. Finally, the over and under exposure regions in the input image 1 are compensated by other images. The results show that the over and under exposure regions in the input image are recovered by our proposed method. (author)

Second Generation Electronic Nicotine Delivery System Vape Pen Exposure Generalizes as a Smoking Cue.

Science.gov (United States)

King, Andrea C; Smith, Lia J; McNamara, Patrick J; Cao, Dingcai

2018-01-05

Second generation electronic nicotine delivery systems (ENDS; also known as e-cigarettes, vaporizers or vape pens) are designed for a customized nicotine delivery experience and have less resemblance to regular cigarettes than first generation "cigalikes." The present study examined whether they generalize as a conditioned cue and evoke smoking urges or behavior in persons exposed to their use. Data were analyzed in N = 108 young adult smokers (≥5 cigarettes per week) randomized to either a traditional combustible cigarette smoking cue or a second generation ENDS vaping cue in a controlled laboratory setting. Cigarette and e-cigarette urge and desire were assessed pre- and post-cue exposure. Smoking behavior was also explored in a subsample undergoing a smoking latency phase after cue exposure (N = 26). The ENDS vape pen cue evoked both urge and desire for a regular cigarette to a similar extent as that produced by the combustible cigarette cue. Both cues produced similar time to initiate smoking during the smoking latency phase. The ENDS vape pen cue elicited smoking urge and desire regardless of ENDS use history, that is, across ENDS naїve, lifetime or current users. Inclusion of past ENDS or cigarette use as covariates did not significantly alter the results. These findings demonstrate that observation of vape pen ENDS use generalizes as a conditioned cue to produce smoking urge, desire, and behavior in young adult smokers. As the popularity of these devices may eventually overtake those of first generation ENDS cigalikes, exposure effects will be of increasing importance. This study shows that passive exposure to a second generation ENDS vape pen cue evoked smoking urge, desire, and behavior across a range of daily and non-daily young adult smokers. Smoking urge and desire increases after vape pen exposure were similar to those produced by exposure to a first generation ENDS cigalike and a combustible cigarette, a known potent cue. Given the increasing

Characterization, Exposure Measurement and Control for Nanoscale Particles in Workplaces and on the Road

International Nuclear Information System (INIS)

Wang Jing; Pui, David Y H

2011-01-01

The amount of engineered nanoparticles is increasing at a rapid rate and more concerns are being raised about the occupational health and safety of nanoparticles in the workplace, and implications of nanotechnology on the environment and living systems. At the same time, diesel engine emissions are one of the serious air pollution sources in urban area. Ultrafine particles on the road can result in harmful effects on the health of drivers and passengers. Research on characterization, exposure measurement and control is needed to address the environmental, health and safety issues of nanoscale particles. We present results of our studies on airborne particles in workplaces and on the road.

Characterization, Exposure Measurement and Control for Nanoscale Particles in Workplaces and on the Road

Energy Technology Data Exchange (ETDEWEB)

Wang Jing [Institute of Environmental Engineering, ETH Zuerich, 8093 (Switzerland); Pui, David Y H, E-mail: jing.wang@ifu.baug.ethz.ch [Particle Technology Laboratory, University of Minnesota, 55414 (United States)

2011-07-06

The amount of engineered nanoparticles is increasing at a rapid rate and more concerns are being raised about the occupational health and safety of nanoparticles in the workplace, and implications of nanotechnology on the environment and living systems. At the same time, diesel engine emissions are one of the serious air pollution sources in urban area. Ultrafine particles on the road can result in harmful effects on the health of drivers and passengers. Research on characterization, exposure measurement and control is needed to address the environmental, health and safety issues of nanoscale particles. We present results of our studies on airborne particles in workplaces and on the road.

Development and implementation of a new radiation exposure record system

International Nuclear Information System (INIS)

Lyon, M.; Berndt, V.L.; Trevino, G.W.; Oakley, B.M.

1993-01-01

The Hanford Radiological Records Program (HRRP) maintains all available radiation exposure records created since the 1940s for employees of and visitors to the Hanford Site. The program provides exposure status reports to the US Department of Energy Richland Operations Office (DOE-RL) and the Hanford contractors, annual exposure reports to individual employees and visitors, and exposure reports to terminated employees. Program staff respond to offsite requests for exposure data on former employees and supply data and reports for epidemiological and research projects as well as for annual reports required by DOE Orders. Historical files, documenting radiation protection and dosimetry policies, procedures, and practices, and radiological incidents, are also maintained under this program. The program is operated by Pacific Northwest Laboratory for DOE-RL. This paper describes how the record-keeping requirements supported by the HRRP's computerized radiation exposure database were analyzed so that the system could be redeveloped and implemented to (1) accommodate a change in mainframe computer units, and (2) to enhance its automated record-keeping, retrieval, and reporting capabilities in support of the HRRP

Dose to population as a metric in the design of optimised exposure control in digital mammography

International Nuclear Information System (INIS)

Klausz, R.; Shramchenko, N.

2005-01-01

This paper describes a methods for automatic optimisation of parameter (AOP) in digital mammography systems. Using a model of the image chain, contrast to noise ratio (CNR) and average glandular dose (AGD) are computed for possible X-ray parameters and breast types. The optimisation process consists of the determination of the operating points providing the lowest possible AGD for each CNR level and breast type. The proposed metric for the dose used in the design of an AOP mode is the resulting dose to the population, computed by averaging the AGD values over the distribution of breast types in the population. This method has been applied to the automatic exposure control of new digital mammography equipment. Breast thickness and composition are estimated from a low dose pre-exposure and used to index tables containing sets of optimised operating points. The resulting average dose to the population ranges from a level comparable to state-of-the-art screen/film mammography to a reduction by a factor of two. Using this method, both CNR and dose are kept under control for all breast types, taking into consideration both individual and collective risk. (authors)

Risk assessment of released cellulose nanocrystals – mimicking inhalatory exposure

International Nuclear Information System (INIS)

Endes, C; Vanhecke, D; Petri-Fink, A; Rothen-Rutishauser, B; Clift, M J D; Müller, S; Foster, E J; Weder, C; Schmid, O

2013-01-01

Cellulose nanocrystals (CNCs) exhibit advantageous chemical and mechanical properties that render them attractive for a wide range of applications. During the life-cycle of CNC containing materials the nanocrystals could be released and become airborne, posing a potential inhalatory exposure risk towards humans. Absent reliable and dose-controlled models that mimic this exposure in situ is a central issue in gaining an insight into the CNC-lung interaction. Here, an Air Liquid Interface Cell Exposure system (ALICE), previously designed for studies of spherical nanoparticles, was used for the first time to establish a realistic physiological exposure test method for inhaled fiber shaped nano-objects; in this case, CNCs isolated from cotton. Applying a microscopy based approach the spatially homogenous deposition of CNCs was demonstrated as a prerequisite of the functioning of the ALICE. Furthermore, reliability and controllability of the system to nebulise high aspect ratio nanomaterials (HARN, e.g. CNCs) was shown. This opens the potential to thoroughly investigate the inhalatory risk of CNCs in vitro using a realistic exposure system.

Short-Term Systemic Effects of Nose-Only Cigarette Smoke Exposure in Mice: Role of Oxidative Stress

Directory of Open Access Journals (Sweden)

Abderrahim Nemmar

2013-01-01

Full Text Available Background/Aims: Long–term cigarette smoking (CS is a major risk factor for respiratory and cardiovascular diseases, and is also known to adversely affect other organs. However, data on the systemic effects of short-term CS exposure (STCSE are scarce. Presently, using a nose-only exposure system, we evaluated the systemic effects of STCSE in mice. Methods: We assessed the effects of CS generated by 9 consecutive cigarettes per day for 4 days in a nose-only exposure system on cardiovascular, hepatic and renal endpoints evaluated on day 5 in mice. Control mice were exposed to air only. Results: CS significantly increased systolic blood pressure and decreased total nitric oxide plasma concentration. Circulating platelets and erythrocyte numbers were also increased. However, STCSE did not significantly increase thrombosis in pial arterioles and venules. STCSE significantly raised plasma alanine aminotransferase and gamma glutamyl transpeptidase activities, but did not affect urea or creatinine concentrations. Interestingly, while STCSE enhanced the production of reactive oxygen species in heart and kidney and lipid peroxidation in heart, liver and kidneys, it also enhanced the antioxidant activity of superoxide dismutase, probably indicating that STCSE causes adaptive reactions to counterbalance the potentially damaging action of oxygen radicals induced by STCSE. Conclusion: These results suggest that STCSE causes blood pressure increase, hepatotoxicity and oxidative stress in the heart, liver and the kidneys. These data provide information on the initial steps leading to the systemic effects of STCSE, a stage at which the diseases may likely be reversed.

Applicability of Long Duration Exposure Facility environmental effects data to the design of Space Station Freedom electrical power system

Science.gov (United States)

Christie, Robert J.; Lu, Cheng-Yi; Aronoff, Irene

1992-01-01

Data defining space environmental effects on the Long Duration Exposure Facility (LDEF) are examined in terms of the design of the electrical power system (EPS) of the Space Station Freedom (SSF). The significant effects of long-term exposure to space are identified with respect to the performance of the LDEF's materials, components, and systems. A total of 57 experiments were conducted on the LDEF yielding information regarding coatings, thermal systems, electronics, optics, and power systems. The resulting database is analyzed in terms of the specifications of the SSF EPS materials and subsystems and is found to be valuable in the design of control and protection features. Specific applications are listed for findings regarding the thermal environment, atomic oxygen, UV and ionizing radiation, debris, and contamination. The LDEF data are shown to have a considerable number of applications to the design and planning of the SSF and its EPS.

Control banding tools for occupational exposure assessment of nanomaterials - Ready for use in a regulatory context?

DEFF Research Database (Denmark)

Liguori, Biase; Hansen, Steffen Foss; Baun, Anders

2016-01-01

area of concern. Therefore, a number of Control Banding (CB)-based tools have been developed in order to assess and manage the potential risks associated with occupational exposure to nanomaterials. In this paper we provide a comparative analysis of different nanomaterial-specific types of control-banding/risk...... developed for different purposes, with different application domains and inclusion criteria. The exposure assessments and derived risk levels are based on different concepts and assumptions and outputs in different formats. The use of requested input parameters for exposure assessment differ greatly among...... the tools. Therefore, direct inter-comparison and combination of the different models into a larger holistic framework is not immediately possible. Harmonization of input parameters and output could allow establishment of an exposure assessment framework with different levels of information requirements....

A case control study of breast cancer risk and exposure to injectable ...

African Journals Online (AJOL)

A case control study of breast cancer risk and exposure to injectable progestogen contraceptives. R. Bailie, J Katzenellenbogen, M. Hoffman, G Schierhout, H Truter, D Dent, A Gudgeon, J van Zyl, L Rosenberg, S Shapiro ...

Verification tests for remote controlled inspection system in nuclear power plants

International Nuclear Information System (INIS)

Kohno, Tadaaki

1986-01-01

Following the increase of nuclear power plants, the total radiation exposure dose accompanying inspection and maintenance works tended to increase. Japan Power Engineering and Inspection Corp. carried out the verification test of a practical power reactor automatic inspection system from November, 1981, to March, 1986, and in this report, the state of having carried out this verification test is described. The objects of the verification test were the equipment which is urgently required for reducing radiation exposure dose, the possibility of realization of which is high, and which is important for ensuring the safety and reliability of plants, that is, an automatic ultrasonic flaw detector for the welded parts of bend pipes, an automatic disassembling and inspection system for control rod driving mechanism, a fuel automatic inspection system, and automatic decontaminating equipments for steam generator water chambers, primary system crud and radioactive gas in coolant. The results of the verification test of these equipments were judged as satisfactory, therefore, the application to actual plants is possible. (Kako, I.)

An Increase in Dietary Supplement Exposures Reported to US Poison Control Centers.

Science.gov (United States)

Rao, Nisha; Spiller, Henry A; Hodges, Nichole L; Chounthirath, Thiphalak; Casavant, Marcel J; Kamboj, Amrit K; Smith, Gary A

2017-09-01

The objective of this study was to investigate the epidemiology of dietary supplement exposures in the USA. A retrospective analysis was conducted of out-of-hospital dietary supplement exposures reported to the National Poison Data System from 2000 through 2012. There were 274,998 dietary supplement exposures from 2000 through 2012. The annual rate of dietary supplement exposures per 100,000 population increased by 46.1% during 2000-2002, decreased 8.8% during 2002-2005, and then increased again by 49.3% from 2005 to 2012. These trends were influenced by the decrease in ma huang exposures starting in 2002. Miscellaneous dietary supplements accounted for 43.9% of all exposures, followed by botanicals (31.9%), hormonal products (15.1%), and other supplements (5.1%). The majority of dietary supplement exposures (70.0%) occurred among children younger than 6 years old and were acute (94.0%) and unintentional (82.9%). Serious medical outcomes accounted for 4.5% of exposures and most (95.0%) occurred among individuals 6 years and older. Ma huang products, yohimbe, and energy products were the categories associated with the greatest toxicity. There was an overall increase in the rate of dietary supplement exposures from 2000 through 2012. Although the majority of these exposures did not require treatment at a health care facility or result in serious medical outcomes, exposures to yohimbe and energy products were associated with considerable toxicity. Our results demonstrate the success of the FDA ban on ma huang products and the need for FDA regulation of yohimbe and energy products in the USA.

Exposure to and recall of violence reduce short-term memory and cognitive control.

Science.gov (United States)

Bogliacino, Francesco; Grimalda, Gianluca; Ortoleva, Pietro; Ring, Patrick

2017-08-08

Previous research has investigated the effects of violence and warfare on individuals' well-being, mental health, and individual prosociality and risk aversion. This study establishes the short- and long-term effects of exposure to violence on short-term memory and aspects of cognitive control. Short-term memory is the ability to store information. Cognitive control is the capacity to exert inhibition, working memory, and cognitive flexibility. Both have been shown to affect positively individual well-being and societal development. We sampled Colombian civilians who were exposed either to urban violence or to warfare more than a decade earlier. We assessed exposure to violence through either the urban district-level homicide rate or self-reported measures. Before undertaking cognitive tests, a randomly selected subset of our sample was asked to recall emotions of anxiety and fear connected to experiences of violence, whereas the rest recalled joyful or emotionally neutral experiences. We found that higher exposure to violence was associated with lower short-term memory abilities and lower cognitive control in the group recalling experiences of violence, whereas it had no effect in the other group. This finding demonstrates that exposure to violence, even if a decade earlier, can hamper cognitive functions, but only among individuals actively recalling emotional states linked with such experiences. A laboratory experiment conducted in Germany aimed to separate the effect of recalling violent events from the effect of emotions of fear and anxiety. Both factors had significant negative effects on cognitive functions and appeared to be independent from each other.

Advanced Controls for Residential Whole-House Ventilation Systems

Energy Technology Data Exchange (ETDEWEB)

Turner, William [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2014-08-01

Whole-house ventilation systems are becoming commonplace in new construction, remodeling/renovation, and weatherization projects, driven by combinations of specific requirements for indoor air quality (IAQ), health and compliance with standards, such as ASHRAE 62.2. Ventilation systems incur an energy penalty on the home via fan power used to drive the airflow, and the additional space-conditioning load associated with heating or cooling the ventilation air. Finding a balance between IAQ and energy use is important if homes are to be adequately ventilated while not increasing the energy burden. This study used computer simulations to examine RIVEC the Residential Integrated Ventilation Controller - a prototype ventilation controller that aims to deliver whole-house ventilation rates that comply with ventilation standards, for the minimum use of energy. Four different whole-house ventilation systems were simulated, both with and without RIVEC, so that the energy and IAQ results could be compared. Simulations were conducted for 13 US climate zones, three house designs, and three envelope leakage values. The results showed that the RIVEC controller could typically return ventilation energy savings greater than 40percent without compromising long-term chronic or short-term acute exposures to relevant indoor contaminants. Critical and average peak power loads were also reduced as a consequence of using RIVEC.

A balance of activity in brain control and reward systems predicts self-regulatory outcomes

OpenAIRE

Lopez, Richard B.; Chen, Pin-Hao A.; Huckins, Jeremy F.; Hofmann, Wilhelm; Kelley, William M.; Heatherton, Todd F.

2017-01-01

Abstract Previous neuroimaging work has shown that increased reward-related activity following exposure to food cues is predictive of self-control failure. The balance model suggests that self-regulation failures result from an imbalance in reward and executive control mechanisms. However, an open question is whether the relative balance of activity in brain systems associated with executive control (vs reward) supports self-regulatory outcomes when people encounter tempting cues in daily lif...

Intelligent automated control of robotic systems for environmental restoration

International Nuclear Information System (INIS)

Harrigan, R.W.

1992-01-01

Remote systems are needed to accomplish many tasks, such as the cleanup of waste sites in which the exposure of personnel to radiation, chemical, explosive, and other hazardous constituents is unacceptable. In addition, hazardous operations, which in the past have been completed by technicians, are under scrutiny because of the high costs and low productivity associated with providing protective clothing and environments. Traditional remote operations have, unfortunately, proven to also have very low productivity when compared with unencumbered human operators. However, recent advances in the integration of sensors and computing into the control of remotely operated equipment has shown great promise for reducing the cost of remote systems by providing faster and safer remote systems. The US Department of Energy's Office of Technology Development (OTD) has sponsored the development of the generic intelligent system controller (GISC) for application to remote system control. The GISC employs a highly modular architecture employing distributed real-time computing resources for speed and efficiency of computation. Currently, the graphics interface of GISC has been implemented on a Unix-based Silicon Graphics computer using commercial animation graphics software modified for real-time updating from sensory systems. A first implementation of GISC has been completed and is currently in use at Hanford, Washington, as part of the underground storage tank robotics technology development program

Heavy metal uranium affects the brain cholinergic system in rat following sub-chronic and chronic exposure

International Nuclear Information System (INIS)

Bensoussan, Helene; Grancolas, Line; Dhieux-Lestaevel, Bernadette; Delissen, Olivia; Vacher, Claire-Marie; Dublineau, Isabelle; Voisin, Philippe; Gourmelon, Patrick; Taouis, Mohammed; Lestaevel, Philippe

2009-01-01

Uranium is a heavy metal naturally present in the environment that may be chronically ingested by the population. Previous studies have shown that uranium is present in the brain and alters behaviour, notably locomotor activity, sensorimotor ability, sleep/wake cycle and the memory process, but also metabolism of neurotransmitters. The cholinergic system mediates many cognitive systems, including those disturbed after chronic exposure to uranium i.e., spatial memory, sleep/wake cycle and locomotor activity. The objective of this study was to assess whether these disorders follow uranium-induced alteration of the cholinergic system. In comparison with 40 control rats, 40 rats drank 40 mg/L uranyl nitrate for 1.5 or 9 months. Cortex and hippocampus were removed and gene expression and protein level were analysed to determine potential changes in cholinergic receptors and acetylcholine levels. The expression of genes showed various alterations in the two brain areas after short- and long-term exposure. Nevertheless, protein levels of the choline acetyltransferase enzyme (ChAT), the vesicular transporter of acetylcholine (VAChT) and the nicotinic receptor β2 sub-unit (nAChRβ2) were unmodified in all cases of the experiment and muscarinic receptor type 1 (m1AChR) protein level was disturbed only after 9 months of exposure in the cortex (-30%). Acetylcholine levels were unchanged in the hippocampus after 1.5 and 9 months, but were decreased in the cortex after 1.5 months only (-22%). Acetylcholinesterase (AChE) activity was also unchanged in the hippocampus but decreased in the cortex after 1.5 and 9 months (-16% and -18%, respectively). Taken together, these data indicate that the cholinergic system is a target of uranium exposure in a structure-dependent and time-dependent manner. These cholinergic alterations could participate in behavioural impairments.

REMIT5.1, Radiation exposure monitoring and information transmittal system

International Nuclear Information System (INIS)

2007-01-01

1 - Description of program or function - The Radiation Exposure Monitoring and Information Transmittal (REMIT) is a PC-based menu driven system that facilitates the manipulation of data base files to record and report radiation exposure information. REMIT is designed to be user-friendly and contains the full text of Regulatory Guide 8.7, Rev.1, on-line as well as context-sensitive help throughout the program. The user can enter data directly from NRC Forms 4 or 5. REMIT allows the user to view the individual's exposure in relation to regulatory or administrative limits and will alert the user to exposures in excess of these limits. The system also provides for the calculation and summation of dose from intakes and the determination of the dose to the maximally exposed extremity for the monitoring year. REMIT can produce NRC Forms 4 and 5 in paper and electronic format and can import/export data from ASCII and data base files. Additional information is available from the web page www.reirs.com. REMIT system is designed to assist U.S. Nuclear Regulatory Commission (NRC) licensees in meeting the reporting requirements of the Revised 10 CFR Parts 20.1001 through 20.2401 as outlined in Regulatory Guide 8.7, Rev.1, Instructions for Recording and Reporting Occupational Exposure Data. 2 - Methods - REMIT makes use of the dose conversion factors from EPA Report 11 Limiting Values of Radionuclide Intake and Air Concentration and Dose Conversion Factors for Inhalation, Submission, and Ingestion, to calculate the Committed Dose Equivalent to the maximally exposed organ and the Committed Effective Dose Equivalent from intakes measured in microcuries. REMIT also estimates the amount (in micrograms) of uranium intake from the activity entered in microcuries. This calculation is based on the specific activities of the uranium isotopes. 3 - Restrictions on the complexity of the problem - None noted

Gene expression profiling in persons with multiple chemical sensitivity before and after a controlled n-butanol exposure session

DEFF Research Database (Denmark)

Dantoft, Thomas Meinertz; Skovbjerg, Sine; Andersson, Linus

2017-01-01

was that unexposed and symptom-free MCS participants have similar gene expression patterns to controls and a second hypothesis that MCS participants can be separated from controls based on differential gene expression upon a controlled n-butanol exposure. Participants were exposed to 3.7 ppm n-butanol while seated...... min after being exposed to and 4 hours after the exposure. Participants suffering from MCS and healthy controls were recruited through advertisement at public places and in a local newspaper. 36 participants who considered themselves sensitive were prescreened for eligibility. 18 sensitive persons...... displayed similar gene expression levels both at baseline and after the exposure and the computed AUC values were likewise comparable between the 2 groups. The intragroup variation in expression levels among MCS participants was noticeably greater than the controls. MCS participants and controls have...

Increase in oxidative stress levels following welding fume inhalation: a controlled human exposure study.

Science.gov (United States)

Graczyk, Halshka; Lewinski, Nastassja; Zhao, Jiayuan; Sauvain, Jean-Jacques; Suarez, Guillaume; Wild, Pascal; Danuser, Brigitta; Riediker, Michael

2016-06-10

Tungsten inert gas (TIG) welding represents one of the most widely used metal joining processes in industry. It has been shown to generate a large majority of particles at the nanoscale and to have low mass emission rates when compared to other types of welding. Despite evidence that TIG fume particles may produce reactive oxygen species (ROS), limited data is available for the time course changes of particle-associated oxidative stress in exposed TIG welders. Twenty non-smoking male welding apprentices were exposed to TIG welding fumes for 60 min under controlled, well-ventilated settings. Exhaled breathe condensate (EBC), blood and urine were collected before exposure, immediately after exposure, 1 h and 3 h post exposure. Volunteers participated in a control day to account for oxidative stress fluctuations due to circadian rhythm. Biological liquids were assessed for total reducing capacity, hydrogen peroxide (H2O2), malondialdehyde (MDA), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentrations at each time point. A linear mixed model was used to assess within day and between day differences. Significant increases in the measured biomarkers were found at 3 h post exposure. At 3 h post exposure, we found a 24 % increase in plasma-H2O2 concentrations ([95%CI: 4 % to 46 %], p = 0.01); a 91 % increase in urinary-H2O2 ([2 % to 258 %], p = 0.04); a 14 % increase in plasma-8-OHdG ([0 % to 31 %], p = 0.049); and a 45 % increase in urinary-8-OHdG ([3 % to 105 %], p = 0.03). Doubling particle number concentration (PNC) exposure was associated with a 22 % increase of plasma-8-OHdG at 3 h post exposure (p = 0.01). A 60-min exposure to TIG welding fume in a controlled, well-ventilated setting induced acute oxidative stress at 3 h post exposure in healthy, non-smoking apprentice welders not chronically exposed to welding fumes. As mass concentration of TIG welding fume particles is very low when compared to other types of welding, it is

REMIT, Radiation Exposure Monitoring and Information Transmittal System

International Nuclear Information System (INIS)

Cale, R.; Clark, T.; Dixson, P.; Hagemeyer, D.; Hardwick, C.; Pippen, H.

1997-01-01

1 - Description of program or function: The Radiation Exposure Monitoring and Information Transmittal (REMIT) system is designed to assist U.S. Nuclear Regulatory Commission (NRC) licensees in meeting the reporting requirements of the Revised 10 CFR Part 20 and in agreement with the guidance contained in Regulatory Guide 8.7, Rev.1, Instructions for Recording and Reporting Occupational Exposure Data. REMIT is a personal computer (PC) -based menu driven system that facilitates the manipulation of data base files to record and report radiation exposure information. REMIT is designed to be user-friendly and contains the full text of Regulatory Guide 8.7, Rev.1, on-line as well as context-sensitive help throughout the program. The user can enter data directly from NRC Form 5s or Form 4s. REMIT allows the user to view the individual's exposure in relation to regulatory or administrative limits and will alert the user to exposures in excess of these limits. The system also provides for the calculation and summation of dose from intakes and the determination of the dose to the maximally exposed extremity for the monitoring year. REMIT can produce NRC Form 5s and 4s in paper and electronic format and can import/export data from ASCII and data base files. 2 - Method of solution: REMIT makes use of the dose conversion factors from EPA Report 11 Limiting Values of Radionuclide Intake and Air Concentration and Dose Conversion Factors for Inhalation, Submission, and Ingestion, to calculate the Committed Dose Equivalent to the maximally exposed organ and the committed Effective Dose Equivalent from intakes measured in micro-curies. REMIT also estimates the amount (in micrograms) of uranium intake from the activity entered in micro-curies. This calculation is based on the specific activities of the uranium isotopes. 3 - Restrictions on the complexity of the problem: REMIT is a single- user system that only runs on IBM compatible PC systems under DOS and supports only Hewlett

Integrated control systems

International Nuclear Information System (INIS)

Smith, D.J.

1991-01-01

This paper reports that instrument manufacturers must develop standard network interfaces to pull together interrelated systems such as automatic start-up, optimization programs, and online diagnostic systems. In the past individual control system manufacturers have developed their own data highways with proprietary hardware and software designs. In the future, electric utilities will require that future systems, irrespective of manufacturer, should be able to communicate with each other. Until now the manufactures of control systems have not agreed on the standard high-speed data highway system. Currently, the Electric Power Research Institute (EPRI), in conjunction with several electric utilities and equipment manufactures, is working on developing a standard protocol for communicating between various manufacturers' control systems. According to N. Michael of Sargent and Lundy, future control room designs will require that more of the control and display functions be accessible from the control room through CRTs. There will be less emphasis on traditional hard-wired control panels

Should the automatic exposure control system of CT be disabled when scanning patients with endoaortic stents or mechanical heart valves? A phantom study

Energy Technology Data Exchange (ETDEWEB)

Di Leo, Giovanni; Zanardo, Moreno; Secchi, Francesco [IRCCS Policlinico San Donato, Radiology Unit, San Donato Milanese (Italy); Spadavecchia, Chiara [Universita degli Studi di Milano, Dipartimento di Fisica, Milano (Italy); Veronese, Ivan [Universita degli Studi di Milano, Dipartimento di Fisica, Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano (Italy); Cantone, Marie Claire [Istituto Nazionale di Fisica Nucleare, Sezione di Milano (Italy); Universita degli Studi di Milano, Dipartimento di Scienze Biomediche, Chirurgiche ed Odontoiatriche, Milano (Italy); Sardanelli, Francesco [IRCCS Policlinico San Donato, Radiology Unit, San Donato Milanese (Italy); Universita degli Studi di Milano, Department of Biomedical Science for Health, San Donato Milanese (Italy)

2017-07-15

To estimate the impact of endoaortic stents/mechanical heart valves on the output of an automatic exposure control (AEC) system and CT radiation dose. In this phantom study, seven stents and two valves were scanned with varying tube voltage (80/100/120 kVp), AEC activation (enabled/disabled) and prosthesis (present/absent), for a total of 540 scans. For each prosthesis, the dose-length product (DLP) was compared between scans with the AEC enabled and disabled. Percentage confidence levels for differences due to the prosthesis were calculated. Differences between results with the AEC enabled and disabled were not statistically significant (p ≥ 0.059). In the comparison with and without the prosthesis, DLP was unchanged at 80 kVp and 100 kVp, while a slight increase was observed at 120 kVp. The radiation dose varied from 1.8 mGy to 2.4 mGy without the prosthesis and from 1.8 mGy to 2.5 mGy with the prosthesis (confidence level 37-100%). The effect of the prosthesis on the AEC system was negligible and not clinically relevant. Therefore, disabling the AEC system when scanning these patients is not likely to provide a benefit. (orig.)

Should the automatic exposure control system of CT be disabled when scanning patients with endoaortic stents or mechanical heart valves? A phantom study

International Nuclear Information System (INIS)

Di Leo, Giovanni; Zanardo, Moreno; Secchi, Francesco; Spadavecchia, Chiara; Veronese, Ivan; Cantone, Marie Claire; Sardanelli, Francesco

2017-01-01

To estimate the impact of endoaortic stents/mechanical heart valves on the output of an automatic exposure control (AEC) system and CT radiation dose. In this phantom study, seven stents and two valves were scanned with varying tube voltage (80/100/120 kVp), AEC activation (enabled/disabled) and prosthesis (present/absent), for a total of 540 scans. For each prosthesis, the dose-length product (DLP) was compared between scans with the AEC enabled and disabled. Percentage confidence levels for differences due to the prosthesis were calculated. Differences between results with the AEC enabled and disabled were not statistically significant (p ≥ 0.059). In the comparison with and without the prosthesis, DLP was unchanged at 80 kVp and 100 kVp, while a slight increase was observed at 120 kVp. The radiation dose varied from 1.8 mGy to 2.4 mGy without the prosthesis and from 1.8 mGy to 2.5 mGy with the prosthesis (confidence level 37-100%). The effect of the prosthesis on the AEC system was negligible and not clinically relevant. Therefore, disabling the AEC system when scanning these patients is not likely to provide a benefit. (orig.)

Transforming the ASDEX Upgrade discharge control system to a general-purpose plasma control platform

International Nuclear Information System (INIS)

Treutterer, Wolfgang; Cole, Richard; Gräter, Alexander; Lüddecke, Klaus; Neu, Gregor; Rapson, Christopher; Raupp, Gerhard; Zasche, Dieter; Zehetbauer, Thomas

2015-01-01

Highlights: • Control framework split in core and custom part. • Core framework deployable in other fusion device environments. • Adaptible through customizable modules, plug-in support and generic interfaces. - Abstract: The ASDEX Upgrade Discharge Control System DCS is a modern and mature product, originally designed to regulate and supervise ASDEX Upgrade Tokamak plasma operation. In its core DCS is based on a generic, versatile real-time software framework with a plugin architecture that allows to easily combine, modify and extend control function modules in order to tailor the system to required features and let it continuously evolve with the progress of an experimental fusion device. Due to these properties other fusion experiments like the WEST project have expressed interest in adopting DCS. For this purpose, essential parts of DCS must be unpinned from the ASDEX Upgrade environment by exposure or introduction of generalised interfaces. Re-organisation of DCS modules allows distinguishing between intrinsic framework core functions and device-specific applications. In particular, DCS must be prepared for deployment in different system environments with their own realisations for user interface, pulse schedule preparation, parameter server, time and event distribution, diagnostic and actuator systems, network communication and data archiving. The article explains the principles of the revised DCS structure, derives the necessary interface definitions and describes major steps to achieve the separation between general-purpose framework and fusion device specific components.

Transforming the ASDEX Upgrade discharge control system to a general-purpose plasma control platform

Energy Technology Data Exchange (ETDEWEB)

Treutterer, Wolfgang, E-mail: Wolfgang.Treutterer@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Cole, Richard [Unlimited Computer Systems, Seeshaupter Str. 15, 82393 Iffeldorf (Germany); Gräter, Alexander [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Lüddecke, Klaus [Unlimited Computer Systems, Seeshaupter Str. 15, 82393 Iffeldorf (Germany); Neu, Gregor; Rapson, Christopher; Raupp, Gerhard; Zasche, Dieter; Zehetbauer, Thomas [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany)

2015-10-15

Highlights: • Control framework split in core and custom part. • Core framework deployable in other fusion device environments. • Adaptible through customizable modules, plug-in support and generic interfaces. - Abstract: The ASDEX Upgrade Discharge Control System DCS is a modern and mature product, originally designed to regulate and supervise ASDEX Upgrade Tokamak plasma operation. In its core DCS is based on a generic, versatile real-time software framework with a plugin architecture that allows to easily combine, modify and extend control function modules in order to tailor the system to required features and let it continuously evolve with the progress of an experimental fusion device. Due to these properties other fusion experiments like the WEST project have expressed interest in adopting DCS. For this purpose, essential parts of DCS must be unpinned from the ASDEX Upgrade environment by exposure or introduction of generalised interfaces. Re-organisation of DCS modules allows distinguishing between intrinsic framework core functions and device-specific applications. In particular, DCS must be prepared for deployment in different system environments with their own realisations for user interface, pulse schedule preparation, parameter server, time and event distribution, diagnostic and actuator systems, network communication and data archiving. The article explains the principles of the revised DCS structure, derives the necessary interface definitions and describes major steps to achieve the separation between general-purpose framework and fusion device specific components.

Analyze for the Quality Control of General X-ray Systems in Capital region

International Nuclear Information System (INIS)

Kang, Byung Sam; Lee, Kang Min; Shin, Woo Yong; Park, Soon Chul; Choi, Hak Dong; Cho, Yong Kwon

2012-01-01

Thanks to the rapid increase of the interest in the quality control of the General X-ray systems, this research proposes the direction of the quality control through comparing and inspecting the actual condition of the respective quality control in the Clinic, the educational institution and the hospital. The subjects of the investigation are diagnostic radiation equipment's in the clinic, the educational institution and the hospital around the capital. A test of kVp, mR/mAs out put test and reproducibility of the exposure dose, half value layer, an accordance between the light field and the beam alignment test, and lastly reproducibility of the exposure time. Then the mean difference of the percentage, the CV (Coefficient of Variation, CV) and the attenuated curve which are respectively resulted from the above tests are computed. After that we have evaluated the values according to the regulations on the Diagnostic Radiation Equipment Safety Administration regulations. In the case of the clinic and the educational institution, there were 22 general X-ray devices. And 18.2% of the kVp test, 13.6% of the reproducibility of exposure dose test, 9.1% of the mR/mAs out put test, and 13.6% of the HVL (Half Value Layer) test appeared to be improper. In the case of the hospital, however, there were 28 devices. And 7.1% of the reproducibility of exposure dose, 7.1% of the difference in the light field/ beam alignment, and 7.1% of the reproducibility of the exposure time appeared to be improper. According to the investigation, the hospital's quality control condition is better than the condition in the clinic and the educational institution. The quality control condition of the general X-ray devices in the clinic is unsatisfactory compared to the hospital. Thus, it is considered that realizing the importance of the quality control is necessary.

Reactor control system. PWR

International Nuclear Information System (INIS)

2009-01-01

At present, 23 units of PWR type reactors have been operated in Japan since the start of Mihama Unit 1 operation in 1970 and various improvements have been made to upgrade operability of power stations as well as reliability and safety of power plants. As the share of nuclear power increases, further improvements of operating performance such as load following capability will be requested for power stations with more reliable and safer operation. This article outlined the reactor control system of PWR type reactors and described the control performance of power plants realized with those systems. The PWR control system is characterized that the turbine power is automatic or manually controlled with request of the electric power system and then the nuclear power is followingly controlled with the change of core reactivity. The system mainly consists of reactor automatic control system (control rod control system), pressurizer pressure control system, pressurizer water level control system, steam generator water level control system and turbine bypass control system. (T. Tanaka)

BSF control system

International Nuclear Information System (INIS)

Irie, Y.; Ishii, K.; Ninomiya, S.; Sasaki, H.; Sakai, I.

1982-08-01

The booster synchrotron utilization facility (BSF) is a facility which utilizes the four fifths of available beam pulses from the KEK booster synchrotron. The BSF control system includes the beam line control, interactions with the PS central control room and the experimental facilities, and the access control system. A brief description of the various components in the control system is given. (author)

Acute effects of acrolein in human volunteers during controlled exposure.

Science.gov (United States)

Dwivedi, Aishwarya M; Johanson, Gunnar; Lorentzen, Johnny C; Palmberg, Lena; Sjögren, Bengt; Ernstgård, Lena

2015-01-01

Acrolein is a reactive aldehyde mainly formed by combustion. The critical effect is considered to be irritation of the eyes and airways; however, the scarce data available make it difficult to assess effect levels. The aim of the study was to determine thresholds for acute irritation for acrolein. Nine healthy volunteers of each sex were exposed at six occasions for 2 h at rest to: clean air, 15 ppm ethyl acetate (EA), and 0.05 ppm and 0.1 ppm acrolein with and without EA (15 ppm) to mask the potential influence of odor. Symptoms related to irritation and central nervous system effects were rated on 100-mm Visual Analogue Scales. The ratings of eye irritation were slightly but significantly increased during exposure to acrolein in a dose-dependent manner (p acrolein alone but not during any of the other five exposure conditions. Based on subjective ratings, the present study showed minor eye irritation by exposure to 0.1 ppm acrolein.

Pesticide exposure and lymphohaematopoietic cancers: a case-control study in an agricultural region (Larissa, Thessaly, Greece).

Science.gov (United States)

Kokouva, Maria; Bitsolas, Nikolaos; Hadjigeorgiou, Georgios M; Rachiotis, George; Papadoulis, Nikolaos; Hadjichristodoulou, Christos

2011-01-04

The causality of lymphohaematopoietic cancers (LHC) is multifactorial and studies investigating the association between chemical exposure and LHC have produced variable results. The aim of this study was to investigate the relationships between exposure to pesticides and LHC in an agricultural region of Greece. A structured questionnaire was employed in a hospital-based case control study to gather information on demographics, occupation, exposure to pesticides, agricultural practices, family and medical history and smoking. To control for confounders, backward conditional and multinomial logistic regression analyses were used. To assess the dose-response relationship between exposure and disease, the chi-square test for trend was used. Three hundred and fifty-four (354) histologically confirmed LHC cases diagnosed from 2004 to 2006 and 455 sex- and age-matched controls were included in the study. Pesticide exposure was associated with total LHC cases (OR 1.46, 95% CI 1.05-2.04), myelodysplastic syndrome (MDS) (OR 1.87, 95% CI 1.00-3.51) and leukaemia (OR 2.14, 95% CI 1.09-4.20). A dose-response pattern was observed for total LHC cases (P = 0.004), MDS (P = 0.024) and leukaemia (P = 0.002). Pesticide exposure was independently associated with total LHC cases (OR 1.41, 95% CI 1.00 - 2.00) and leukaemia (OR 2.05, 95% CI 1.02-4.12) after controlling for age, smoking and family history (cancers, LHC and immunological disorders). Smoking during application of pesticides was strongly associated with total LHC cases (OR 3.29, 95% CI 1.81-5.98), MDS (OR 3.67, 95% CI 1.18-12.11), leukaemia (OR 10.15, 95% CI 2.15-65.69) and lymphoma (OR 2.72, 95% CI 1.02-8.00). This association was even stronger for total LHC cases (OR 18.18, 95% CI 2.38-381.17) when eating simultaneously with pesticide application. Lymphohaematopoietic cancers were associated with pesticide exposure after controlling for confounders. Smoking and eating during pesticide application were identified as

Should the automatic exposure control system of CT be disabled when scanning patients with endoaortic stents or mechanical heart valves? A phantom study.

Science.gov (United States)

Di Leo, Giovanni; Spadavecchia, Chiara; Zanardo, Moreno; Secchi, Francesco; Veronese, Ivan; Cantone, Marie Claire; Sardanelli, Francesco

2017-07-01

To estimate the impact of endoaortic stents/mechanical heart valves on the output of an automatic exposure control (AEC) system and CT radiation dose. In this phantom study, seven stents and two valves were scanned with varying tube voltage (80/100/120 kVp), AEC activation (enabled/disabled) and prosthesis (present/absent), for a total of 540 scans. For each prosthesis, the dose-length product (DLP) was compared between scans with the AEC enabled and disabled. Percentage confidence levels for differences due to the prosthesis were calculated. Differences between results with the AEC enabled and disabled were not statistically significant (p ≥ 0.059). In the comparison with and without the prosthesis, DLP was unchanged at 80 kVp and 100 kVp, while a slight increase was observed at 120 kVp. The radiation dose varied from 1.8 mGy to 2.4 mGy without the prosthesis and from 1.8 mGy to 2.5 mGy with the prosthesis (confidence level 37-100%). The effect of the prosthesis on the AEC system was negligible and not clinically relevant. Therefore, disabling the AEC system when scanning these patients is not likely to provide a benefit. • CT-AEC system is not impaired in patients with endoaortic prostheses/heart valves. • Negligible differences may be observed only at 120 kVp. • Disabling the AEC system in these patients is not recommended.

Renal effects of acute exposure to toluene. A controlled clinical trial

DEFF Research Database (Denmark)

Nielsen, H K; Krusell, Lars Romer; Bælum, Jesper

1985-01-01

Urinary excretion rates of beta 2-microglobulin and albumin were measured in 43 male printing trade workers and 43 age-matched male controls before and during exposure to toluene, 382 mg/m3, for 6 1/2 hours in a climate chamber. There were no significant changes in renal excretion rates of albumin...

The influence of potential exposure to radiation protection system of accelerator installation TESLA

International Nuclear Information System (INIS)

Orlic, M.; Cuknic, O.

2000-01-01

Potential exposure of individuals at big nuclear machines like Accelerator Installation Tesla (AIT) generates direct requirements to reliability of radiation protection system. Starting from technical characteristics of AlT and international recommendation concerning potential exposure and the probability of death has been calculated. The reference risk has been specified. Comparing then we calculated the probability of the failure of the protective system. The reliability of the system has to be better (author)

Prenatal Alcohol Exposure and the Developing Immune System.

Science.gov (United States)

Gauthier, Theresa W

2015-01-01

Evidence from research in humans and animals suggest that ingesting alcohol during pregnancy can disrupt the fetal immune system and result in an increased risk of infections and disease in newborns that may persist throughout life. Alcohol may have indirect effects on the immune system by increasing the risk of premature birth, which itself is a risk factor for immune-related problems. Animal studies suggest that alcohol exposure directly disrupts the developing immune system. A comprehensive knowledge of the mechanisms underlying alcohol's effects on the developing immune system only will become clear once researchers establish improved methods for identifying newborns exposed to alcohol in utero.

A Randomized, Controlled Trial of Meditation Compared to Exposure Therapy and Education Control on PTSD in Veterans

Science.gov (United States)

2015-10-01

score >45. Exclusion criteria: Service related trauma within last 3 months, history of schizophrenia, bipolar disorder , dementia, moderate or severe...7.7% 0.0% 8.3% 0.191 Bipolar disorder , % 7.7% 10.3% 13.9% 0.681 Substance use disorder , % 30.8% 43.6% 41.7% 0.458 Major depressive disorder ...Award Number: W81XWH-12-1-0576 TITLE: A Randomized, Controlled Trial of Meditation Compared to Exposure Therapy and Education Control on PTSD in

Precision digital control systems

Science.gov (United States)

Vyskub, V. G.; Rozov, B. S.; Savelev, V. I.

This book is concerned with the characteristics of digital control systems of great accuracy. A classification of such systems is considered along with aspects of stabilization, programmable control applications, digital tracking systems and servomechanisms, and precision systems for the control of a scanning laser beam. Other topics explored are related to systems of proportional control, linear devices and methods for increasing precision, approaches for further decreasing the response time in the case of high-speed operation, possibilities for the implementation of a logical control law, and methods for the study of precision digital control systems. A description is presented of precision automatic control systems which make use of electronic computers, taking into account the existing possibilities for an employment of computers in automatic control systems, approaches and studies required for including a computer in such control systems, and an analysis of the structure of automatic control systems with computers. Attention is also given to functional blocks in the considered systems.

Auditory stimulation by exposure to melodic music increases dopamine and serotonin activities in rat forebrain areas linked to reward and motor control.

Science.gov (United States)

Moraes, Michele M; Rabelo, Patrícia C R; Pinto, Valéria A; Pires, Washington; Wanner, Samuel P; Szawka, Raphael E; Soares, Danusa D

2018-04-23

Listening to melodic music is regarded as a non-pharmacological intervention that ameliorates various disease symptoms, likely by changing the activity of brain monoaminergic systems. Here, we investigated the effects of exposure to melodic music on the concentrations of dopamine (DA), serotonin (5-HT) and their respective metabolites in the caudate-putamen (CPu) and nucleus accumbens (NAcc), areas linked to reward and motor control. Male adult Wistar rats were randomly assigned to a control group or a group exposed to music. The music group was submitted to 8 music sessions [Mozart's sonata for two pianos (K. 488) at an average sound pressure of 65 dB]. The control rats were handled in the same way but were not exposed to music. Immediately after the last exposure or control session, the rats were euthanized, and their brains were quickly removed to analyze the concentrations of 5-HT, DA, 5-hydroxyindoleacetic acid (5-HIAA) and 3,4-dihydroxyphenylacetic acid (DOPAC) in the CPu and NAcc. Auditory stimuli affected the monoaminergic system in these two brain structures. In the CPu, auditory stimuli increased the concentrations of DA and 5-HIAA but did not change the DOPAC or 5-HT levels. In the NAcc, music markedly increased the DOPAC/DA ratio, suggesting an increase in DA turnover. Our data indicate that auditory stimuli, such as exposure to melodic music, increase DA levels and the release of 5-HT in the CPu as well as DA turnover in the NAcc, suggesting that the music had a direct impact on monoamine activity in these brain areas. Copyright © 2018 Elsevier B.V. All rights reserved.

Association between aflatoxin B1 occupational airway exposure and risk of hepatocellular carcinoma: a case-control study.

Science.gov (United States)

Lai, Hao; Mo, Xianwei; Yang, Yang; He, Ke; Xiao, Jun; Liu, Chao; Chen, Jiansi; Lin, Yuan

2014-10-01

The aim of this study was to determine the airway exposure of sugar and papermaking factory workers to aflatoxin B1 (AFB1) and to explore the potential association between AFB1 airway exposure and the risk of hepatocellular carcinoma (HCC) in a case-control study. Dust samples were collected from the sugarcane bagasse warehouse, and presser and paper production workshops. Blood samples were collected from 181 workshop employees and 203 controls who worked outside the workshop. AFB1 albumin adducts were detected using a double antibody sandwich enzyme-linked immunosorbent assay (ELISA). To explore the association between AFB1 airway exposure and the risk of HCC, the medical records of 68 HCC patients who worked in a sugar and papermaking factory between January 1994 and December 2013 were analyzed. A questionnaire was used to collect information from 150 healthy controls who worked for the same company and lived near the factory. AFB1 was detected in the dust samples, but could not be detected in any of the rice samples. An analysis of serum samples revealed serum AFB1 albumin adducts in 102 (56.35 %) of the study participants. However, in the control group, only 12 (5.9 %) individuals had detectable levels of AFB1 albumin adducts. Those with airway exposure to Aspergillus flavus-contaminated dust had an elevated risk of HCC compared to those without exposure (odds ratio, 5.24; 95 % confidence interval, 2.77-9.88; P = 0.00). The findings of this study indicate that occupational AFB1 airway exposure might be associated with the risk of AFB1-related HCC among the population that was used in this study. Intervention programs aimed at reducing exposure to inhalational AFB1 are needed urgently. Additional suitably designed, multicenter, prospective studies using large samples are needed to further confirm the results.

Local Gene Delivery System by Bubble Liposomes and Ultrasound Exposure into Joint Synovium

Directory of Open Access Journals (Sweden)

Yoichi Negishi

2011-01-01

Full Text Available Recently, we have developed novel polyethylene glycol modified liposomes (bubble liposomes; BL entrapping an ultrasound (US imaging gas, which can work as a gene delivery tool with US exposure. In this study, we investigated the usefulness of US-mediated gene transfer systems with BL into synoviocytes in vitro and joint synovium in vivo. Highly efficient gene transfer could be achieved in the cultured primary synoviocytes transfected with the combination of BL and US exposure, compared to treatment with plasmid DNA (pDNA alone, pDNA plus BL, or pDNA plus US. When BL was injected into the knee joints of mice, and US exposure was applied transcutaneously to the injection site, highly efficient gene expression could be observed in the knee joint transfected with the combination of BL and US exposure, compared to treatment with pDNA alone, pDNA plus BL, or pDNA plus US. The localized and prolonged gene expression was also shown by an in vivo luciferase imaging system. Thus, this local gene delivery system into joint synovium using the combination of BL and US exposure may be an effective means for gene therapy in joint disorders.

A population-based case-control study on statin exposure and risk of acute diverticular disease.

Science.gov (United States)

Sköldberg, Filip; Svensson, Tobias; Olén, Ola; Hjern, Fredrik; Schmidt, Peter T; Ljung, Rickard

2016-01-01

A reduced risk of perforated diverticular disease among individuals with current statin exposure has been reported. The aim of the present study was to investigate whether statins reduce the risk of acute diverticular disease. A nation-wide population-based case-control study was performed, including 13,127 cases hospitalised during 2006-2010 with a first-time diagnosis of colonic diverticular disease, and 128,442 control subjects (matched for sex, age, county of residence and calendar year). Emergency surgery, assumed to be a proxy for complicated diverticulitis, was performed on 906 of the cases during the index admission, with 8818 matched controls. Statin exposure was classified as "current" or "former" if a statin prescription was last dispensed ≤ 125 days or >125 days before index date, respectively. The association between statin exposure and acute diverticular disease was investigated by conditional logistic regression, including models adjusting for country of birth, educational level, marital status, comorbidities, nonsteroidal anti-inflammatory drug/steroid exposure and healthcare utilisation. A total of 1959 cases (14.9%) and 16,456 controls (12.8%) were current statin users (crude OR 1.23 [95% CI 1.17-1.30]; fully adjusted OR 1.00 [0.94-1.06]). One hundred and thirty-two of the cases subjected to surgery (14.6%), and 1441 of the corresponding controls (16.3%) were current statin users (crude OR 0.89 [95% CI 0.73-1.08]; fully adjusted OR 0.70 [0.55-0.89]). The results do not indicate that statins affect the development of symptomatic diverticular disease in general. However, current statin use was associated with a reduced risk of emergency surgery for diverticular disease.

Long-term exposure to noise impairs cortical sound processing and attention control.

Science.gov (United States)

Kujala, Teija; Shtyrov, Yury; Winkler, Istvan; Saher, Marieke; Tervaniemi, Mari; Sallinen, Mikael; Teder-Sälejärvi, Wolfgang; Alho, Kimmo; Reinikainen, Kalevi; Näätänen, Risto

2004-11-01

Long-term exposure to noise impairs human health, causing pathological changes in the inner ear as well as other anatomical and physiological deficits. Numerous individuals are daily exposed to excessive noise. However, there is a lack of systematic research on the effects of noise on cortical function. Here we report data showing that long-term exposure to noise has a persistent effect on central auditory processing and leads to concurrent behavioral deficits. We found that speech-sound discrimination was impaired in noise-exposed individuals, as indicated by behavioral responses and the mismatch negativity brain response. Furthermore, irrelevant sounds increased the distractibility of the noise-exposed subjects, which was shown by increased interference in task performance and aberrant brain responses. These results demonstrate that long-term exposure to noise has long-lasting detrimental effects on central auditory processing and attention control.

Leptospira Exposure and Patients with Liver Diseases: A Case-Control Seroprevalence Study

Science.gov (United States)

Alvarado-Esquivel, Cosme; Sánchez-Anguiano, Luis Francisco; Hernández-Tinoco, Jesús; Ramos-Nevárez, Agar; Margarita Cerrillo-Soto, Sandra; Alberto Guido-Arreola, Carlos

2016-01-01

The seroepidemiology of Leptospira infection in patients suffering from liver disease has been poorly studied. Information about risk factors associated with infection in liver disease patients may help in the optimal planning of preventive measures. We sought to determine the association of Leptospira IgG seroprevalence and patients with liver diseases, and to determine the characteristics of the patients with Leptospira exposure. We performed a case-control study of 75 patients suffering from liver diseases and 150 age- and gender-matched control subjects. Diagnoses of liver disease included liver cirrhosis, steatosis, chronic hepatitis, acute hepatitis, and amoebic liver abscess. Sera of participants were analyzed for the presence of anti- Leptospira IgG antibodies using a commercially available enzyme immunoassay. Anti-Leptospira IgG antibodies were found in 17 (22.7%) of 75 patients and in 15 (10.0%) of 150 control subjects (OR = 2.32; 95% CI: 1.09-4.94; P=0.03). This is the first age- and gender-matched case control study about Leptospira seroprevalence in patients with liver diseases. Results indicate that Leptospira infection is associated with chronic and acute liver diseases. Results warrants for additional studies on the role of Leptospira exposure in chronic liver disease. PMID:27493589

Control system design method

Science.gov (United States)

Wilson, David G [Tijeras, NM; Robinett, III, Rush D.

2012-02-21

A control system design method and concomitant control system comprising representing a physical apparatus to be controlled as a Hamiltonian system, determining elements of the Hamiltonian system representation which are power generators, power dissipators, and power storage devices, analyzing stability and performance of the Hamiltonian system based on the results of the determining step and determining necessary and sufficient conditions for stability of the Hamiltonian system, creating a stable control system based on the results of the analyzing step, and employing the resulting control system to control the physical apparatus.

ACREM: A new air crew radiation exposure measuring system

International Nuclear Information System (INIS)

Beck, P.; Duftschmid, K.; Kerschbaumer, S.; Schmitzer, C.; Strachotinsky, C.; Grosskopf, A.; Winkler, N.

1996-01-01

Cosmic radiation has already been discovered in 1912 by the Austrian Nobel Laureate Victor F. Hess. After Hess up to now numerous measurements of the radiation exposure by cosmic rays in different altitudes have been performed, however, this has not been taken serious in view of radiation protection.Today, with the fast development of modern airplanes, an ever increasing number of civil aircraft is flying in increasing altitudes for considerable time. Members of civil aircrew spending up to 1000 hours per year in cruising altitudes and therefore are subject to significant levels of radiation exposure. In 1990 ICRP published its report ICRP 60 with updated excess cancer risk estimates, which led to significantly higher risk coefficients for some radiation qualities. An increase of the radiation weighting factors for mean energy neutron radiation increases the contribution for the neutron component to the equivalent dose by about 60%, as compared to the earlier values of ICRP26. This higher risk coefficients lead to the recommendation of the ICRP, that cosmic radiation exposure in civil aviation should be taken into account as occupational exposure. Numerous recent exposure measurements at civil airliners in Germany, Sweden, USA, and Russia show exposure levels in the range of 3-10 mSv/year. This is significantly more than the average annual dose of radiation workers (in Austria about 1.5 mSv/year). Up to now no practicable and economic radiation monitoring system for routine application on board exits. A fairly simple and economic approach to a practical, active in-flight dosimeter for the assessment of individual crew exposure is discussed in this paper

Cumulative risk exposure moderates the association between parasympathetic reactivity and inhibitory control in preschool-age children.

Science.gov (United States)

Giuliano, Ryan J; Roos, Leslie E; Farrar, Jessica D; Skowron, Elizabeth A

2018-04-01

A child's cumulative risk for early exposure to stress has been linked to alterations of self-regulation outcomes, including neurobiological correlates of inhibitory control (IC). We examined whether children's ability to engage the parasympathetic nervous system impacts how risk affects IC. Children ages 3-5 years completed two laboratory measures of IC while respiratory sinus arrhythmia (RSA) was measured, indexing parasympathetic activity. Children with greater risk demonstrated lower IC; risk also moderated associations between RSA reactivity and IC. For children with less risk, greater RSA withdrawal during IC tasks was associated with better IC. In contrast, greater risk was associated with poor IC, regardless of RSA withdrawal. Effects of risk were more pronounced for cumulative than individual measures. Results suggest that cumulative risk exposure disrupts connectivity between physiological and behavioral components of self-regulation in early childhood. Parasympathetic withdrawal to cognitive tasks may be less relevant for performance in developmental samples experiencing greater life stress. © 2018 Wiley Periodicals, Inc.

Assessment of automatic exposure control performance in digital mammography using a no-reference anisotropic quality index

Science.gov (United States)

Barufaldi, Bruno; Borges, Lucas R.; Bakic, Predrag R.; Vieira, Marcelo A. C.; Schiabel, Homero; Maidment, Andrew D. A.

2017-03-01

Automatic exposure control (AEC) is used in mammography to obtain acceptable radiation dose and adequate image quality regardless of breast thickness and composition. Although there are physics methods for assessing the AEC, it is not clear whether mammography systems operate with optimal dose and image quality in clinical practice. In this work, we propose the use of a normalized anisotropic quality index (NAQI), validated in previous studies, to evaluate the quality of mammograms acquired using AEC. The authors used a clinical dataset that consists of 561 patients and 1,046 mammograms (craniocaudal breast views). The results show that image quality is often maintained, even at various radiation levels (mean NAQI = 0.14 +/- 0.02). However, a more careful analysis of NAQI reveals that the average image quality decreases as breast thickness increases. The NAQI is reduced by 32% on average, when the breast thickness increases from 31 to 71 mm. NAQI also decreases with lower breast density. The variation in breast parenchyma alone cannot fully account for the decrease of NAQI with thickness. Examination of images shows that images of large, fatty breasts are often inadequately processed. This work shows that NAQI can be applied in clinical mammograms to assess mammographic image quality, and highlights the limitations of the automatic exposure control for some images.

Incoherent control of locally controllable quantum systems

International Nuclear Information System (INIS)

Dong Daoyi; Zhang Chenbin; Rabitz, Herschel; Pechen, Alexander; Tarn, T.-J.

2008-01-01

An incoherent control scheme for state control of locally controllable quantum systems is proposed. This scheme includes three steps: (1) amplitude amplification of the initial state by a suitable unitary transformation, (2) projective measurement of the amplified state, and (3) final optimization by a unitary controlled transformation. The first step increases the amplitudes of some desired eigenstates and the corresponding probability of observing these eigenstates, the second step projects, with high probability, the amplified state into a desired eigenstate, and the last step steers this eigenstate into the target state. Within this scheme, two control algorithms are presented for two classes of quantum systems. As an example, the incoherent control scheme is applied to the control of a hydrogen atom by an external field. The results support the suggestion that projective measurements can serve as an effective control and local controllability information can be used to design control laws for quantum systems. Thus, this scheme establishes a subtle connection between control design and controllability analysis of quantum systems and provides an effective engineering approach in controlling quantum systems with partial controllability information.

Respiratory and cardiovascular response during electronic control device (ECD exposure in law enforcement trainees

Directory of Open Access Journals (Sweden)

Kirsten M. VanMeenen

2013-04-01

Full Text Available Objective: Law enforcement represents a large population of workers who may be exposed to electronic control devices (ECDs. Little is known about the potential effect of exposure to these devices on respiration or cardiovascular response during current discharge. Methods: Participants (N=23 were trainees exposed to 5 seconds of an ECD (Taser X26® as a component of training. Trainees were asked to volitionally inhale during exposure. Respiratory recordings involved a continuous waveform recorded throughout the session including during the exposure period. Heart rate was calculated from a continuous pulse oximetry recording. Results: The exposure period resulted in the cessation of normal breathing patterns in all participants and in particular a decrease in inspiratory activity. No significant changes in heart rate during ECD exposure were found. Conclusions: This is the first study to examine breathing patterns during ECD exposure with the resolution to detect changes over this discrete period of time. In contrast to reports suggesting respiration is unaffected by ECDs, present evidence suggests that voluntary inspiration is severely compromised. There is no evidence of cardiac disruption during ECD exposure.

Adolescents with and without gestational cocaine exposure: Longitudinal analysis of inhibitory control, memory and receptive language.

Science.gov (United States)

Betancourt, Laura M; Yang, Wei; Brodsky, Nancy L; Gallagher, Paul R; Malmud, Elsa K; Giannetta, Joan M; Farah, Martha J; Hurt, Hallam

2011-01-01

Preclinical studies of gestational cocaine exposure (GCE) show evidence of changes in brain function at the anatomical, physiological, and behavioral levels, to include effects on developing dopaminergic systems. In contrast, human studies have produced less consistent results, with most showing small effects or no effects on developmental outcomes. Important changes in brain structure and function occur through adolescence, therefore it is possible that prenatal cocaine exposure has latent effects on neurocognitive (NC) outcome that do not manifest until adolescence or young adulthood. We examined NC function using a set of 5 tasks designed to tap 4 different systems: inhibitory control, working memory, receptive language, and incidental memory. For each NC task, data were collected longitudinally at ages 12, 14.5 and 17 years and examined using generalized estimating equations. One hundred and nine children completed at least two of the three evaluations. Covariates included in the final model were assessment number, gender, participant age at first assessment, caregiver depression, and two composites from the Home Observation for Measurement of the Environment (HOME), Environmental Stimulation and Parental Nurturance. We found no cocaine effects on inhibitory control, working memory, or receptive language (p=0.18). GCE effects were observed on incidental face memory task (p=0.055), and GCE by assessment number interaction effects were seen on the incidental word memory task (p=0.031). Participant performance on inhibitory control, working memory, and receptive language tasks improved over time. HOME Environmental Stimulation composite was associated with better receptive language functioning. With a larger sample size smaller differences between groups may have been detected. This report shows no evidence of latent effects of GCE on inhibitory control, working memory, or receptive language. GCE effects were observed on the incidental face memory task, and GCE by

Control systems engineering

CERN Document Server

Nise, Norman S

1995-01-01

This completely updated new edition shows how to use MATLAB to perform control-system calculations. Designed for the professional or engineering student who needs a quick and readable update on designing control systems, the text features a series of tightly focused examples that clearly illustrate each concept of designing control systems. Most chapters conclude with a detailed application from the two case studies that run throughout the book: an antenna asimuth control system and a submarine. The author also refers to many examples of design methods.

Order of exposure to pleasant and unpleasant odors affects autonomic nervous system response.

Science.gov (United States)

Horii, Yuko; Nagai, Katsuya; Nakashima, Toshihiro

2013-04-15

When mammals are exposed to an odor, that odor is expected to elicit a physiological response in the autonomic nervous system. An unpleasant aversive odor causes non-invasive stress, while a pleasant odor promotes healing and relaxation in mammals. We hypothesized that pleasant odors might reduce a stress response previously induced by an aversive predator odor. Rats were thus exposed to pleasant and unpleasant odors in different orders to determine whether the order of odor exposure had an effect on the physiological response in the autonomic nervous system. The first trial examined autonomic nerve activity via sympathetic and parasympathetic nerve response while the second trial examined body temperature response. Initial exposure to a pleasant odor elicited a positive response and secondary exposure to an unpleasant odor elicited a negative response, as expected. However, we found that while initial exposure to an unpleasant odor elicited a negative stress response, subsequent secondary exposure to a pleasant odor not only did not alleviate that negative response, but actually amplified it. These findings were consistent for both the autonomic nerve activity response trial and the body temperature response trial. The trial results suggest that exposure to specific odors does not necessarily result in the expected physiological response and that the specific order of exposure plays an important role. Our study should provide new insights into our understanding of the physiological response in the autonomic nervous system related to odor memory and discrimination and point to areas that require further research. Copyright © 2013 Elsevier B.V. All rights reserved.

Discrete control systems

CERN Document Server

Okuyama, Yoshifumi

2014-01-01

Discrete Control Systems establishes a basis for the analysis and design of discretized/quantized control systemsfor continuous physical systems. Beginning with the necessary mathematical foundations and system-model descriptions, the text moves on to derive a robust stability condition. To keep a practical perspective on the uncertain physical systems considered, most of the methods treated are carried out in the frequency domain. As part of the design procedure, modified Nyquist–Hall and Nichols diagrams are presented and discretized proportional–integral–derivative control schemes are reconsidered. Schemes for model-reference feedback and discrete-type observers are proposed. Although single-loop feedback systems form the core of the text, some consideration is given to multiple loops and nonlinearities. The robust control performance and stability of interval systems (with multiple uncertainties) are outlined. Finally, the monograph describes the relationship between feedback-control and discrete ev...

Individual dose monitoring of occupational exposure in nuclear industry system (1991-2000)

International Nuclear Information System (INIS)

Yang Lianzhen; Ma Jizeng; Li Taosheng

2005-01-01

The summary and main results of individual dose monitoring (1990-2000) from occupational exposure in China Nuclear Industry System are presented in this paper. During ten years, the external collective effective dose to workers in seven plants (not uranium mines and processing mills) and institutes is 98.48 person ·Sv, the per capita effective dose is 1.97 mSv. The general situation for individual dose monitoring from internal exposure is also introduced. The annual average committed effective dose is less than 5.0 mSv. The individual dose monitoring results (1991-1992) for occupational exposure from Uranium mines and processing mills are depicted. In the end, the individual dose monitoring data in nuclear industry system are preliminarily analysed. (authors)

Concept design of multipurpose gamma irradiator ISG-500 instrumentation and control system

International Nuclear Information System (INIS)

Dian F Atmoko; Sutomo B; Ikhsan S; A Suntoro

2010-01-01

Has been concept designed of multipurpose 2 x 250 kCi gamma irradiator instrumentation and control system (ICS). The problem in ICS of irradiator is How to get similar of dose rate and start-up/shut down mechanism with highest safety factor. The concept designed of ICS had of tree parameter such as safety, operation and security. The tree of parameter used to start-up and shut-down in irradiator installation with interlock system connection to guarantee of safety. Similar of dose rate obtained by controlled of exposure time witch stopped of carrier conveyor in point of stopped carrier and for delay time, with speed of moved motor carrier to set in constant speed. (author)

Quantitative safety assessment of air traffic control systems through system control capacity

Science.gov (United States)

Guo, Jingjing

Quantitative Safety Assessments (QSA) are essential to safety benefit verification and regulations of developmental changes in safety critical systems like the Air Traffic Control (ATC) systems. Effectiveness of the assessments is particularly desirable today in the safe implementations of revolutionary ATC overhauls like NextGen and SESAR. QSA of ATC systems are however challenged by system complexity and lack of accident data. Extending from the idea "safety is a control problem" in the literature, this research proposes to assess system safety from the control perspective, through quantifying a system's "control capacity". A system's safety performance correlates to this "control capacity" in the control of "safety critical processes". To examine this idea in QSA of the ATC systems, a Control-capacity Based Safety Assessment Framework (CBSAF) is developed which includes two control capacity metrics and a procedural method. The two metrics are Probabilistic System Control-capacity (PSC) and Temporal System Control-capacity (TSC); each addresses an aspect of a system's control capacity. And the procedural method consists three general stages: I) identification of safety critical processes, II) development of system control models and III) evaluation of system control capacity. The CBSAF was tested in two case studies. The first one assesses an en-route collision avoidance scenario and compares three hypothetical configurations. The CBSAF was able to capture the uncoordinated behavior between two means of control, as was observed in a historic midair collision accident. The second case study compares CBSAF with an existing risk based QSA method in assessing the safety benefits of introducing a runway incursion alert system. Similar conclusions are reached between the two methods, while the CBSAF has the advantage of simplicity and provides a new control-based perspective and interpretation to the assessments. The case studies are intended to investigate the

Development of a new categorization system for pesticides exposure to support harmonized reporting between EU Member States.

Science.gov (United States)

Settimi, Laura; Orford, Rob; Davanzo, Franca; Hague, Charlotte; Desel, Herbert; Pelclova, Daniela; Dragelyte, Gabija; Mathieu-Nolf, Monique; Adams, Richard; Duarte-Davidson, Raquel

2016-05-01

European legislation requires reporting from Member States on acute poisoning incidents involving pesticides. However, standard rules for data collection and reporting have not yet been set out. The new categorization system presented in this paper is aimed at enabling Member States to gather comparable data and provide standard reporting on pesticide poisoning exposures. European Regulations providing separate official categorization of biocidal and plant protection pesticides, were used as a basis to build up a unified pesticide categorization and coding system. Data on selected pesticide exposures collected by Poison Control Centres in six EU countries were reviewed, categorized and reported according to the proposed system. The resulting pesticide categorization system has two dimensions. The first part identifies the main category of use, i.e. biocide/plant protection pesticide/unknown, and the secondary category of use, e.g. Rodenticides, Insecticides and acaricides. The second part of the system is organized into two levels: level one identifies chemical grouping, e.g. Coumarins, Pyrethrins/pyrethroids, while level two identifies the active compound by using its Chemical Abstract Service Registry Number. The system was used to provide a unified categorization to compare exposures to plant protection and biocidal Rodenticides and Pyrethrins/pyrethroids Insecticides and acaricides identified by six EU member states. The developed pesticide categorization system was successfully applied to data extracted from different databases and was able to make the required information comparable. The data reported filling in common templates containing a pre-ordinate list of active compounds categorized according the proposed system, highlighted different capabilities in data collection and recording, showing that some of the collaborating centres were not able to distinguish between main categories of pesticide products or provide information on active compounds. The

U.K. Foot and Mouth Disease: A Systemic Risk Assessment of Existing Controls.

Science.gov (United States)

Delgado, João; Pollard, Simon; Pearn, Kerry; Snary, Emma L; Black, Edgar; Prpich, George; Longhurst, Phil

2017-09-01

This article details a systemic analysis of the controls in place and possible interventions available to further reduce the risk of a foot and mouth disease (FMD) outbreak in the United Kingdom. Using a research-based network analysis tool, we identify vulnerabilities within the multibarrier control system and their corresponding critical control points (CCPs). CCPs represent opportunities for active intervention that produce the greatest improvement to United Kingdom's resilience to future FMD outbreaks. Using an adapted 'features, events, and processes' (FEPs) methodology and network analysis, our results suggest that movements of animals and goods associated with legal activities significantly influence the system's behavior due to their higher frequency and ability to combine and create scenarios of exposure similar in origin to the U.K. FMD outbreaks of 1967/8 and 2001. The systemic risk assessment highlights areas outside of disease control that are relevant to disease spread. Further, it proves to be a powerful tool for demonstrating the need for implementing disease controls that have not previously been part of the system. © 2016 The Authors Risk Analysis published by Wiley Periodicals, Inc. on behalf of Society for Risk Analysis.

Optimization (Alara) and probabilistic exposures: the application of optimization criteria to the control of risks due to exposures of a probabilistic nature

International Nuclear Information System (INIS)

Gonzalez, A.J.

1989-01-01

The paper described the application of the principles of optimization recommended by the International Commission on Radiological Protection (ICRP) to the restrain of radiation risks due to exposures that may or may not be incurred and to which a probability of occurrence can be assigned. After describing the concept of probabilistic exposures, it proposes a basis for a converging policy of control for both certain and probabilistic exposures, namely the dose-risk relationship adopted for radiation protection purposes. On that basis some coherent approaches for dealing with probabilistic exposures, such as the limitation of individual risks, are discussed. The optimization of safety for reducing all risks from probabilistic exposures to as-low-as-reasonably-achievable (ALARA) levels is reviewed in full. The principles of optimization of protection are used as a basic framework and the relevant factors to be taken into account when moving to probabilistic exposures are presented. The paper also reviews the decision-aiding techniques suitable for performing optimization with particular emphasis to the multi-attribute utility-analysis technique. Finally, there is a discussion on some practical application of decision-aiding multi-attribute utility analysis to probabilistic exposures including the use of probabilistic utilities. In its final outlook, the paper emphasizes the need for standardization and solutions to generic problems, if optimization of safety is to be successful

Study of the effect of the variation of automatic exposure control in computed tomography; Estudio del efecto de la variacion del control automatico de exposicion en tomografia computarizada

Energy Technology Data Exchange (ETDEWEB)

Nersissian, D. Y.; Capeleti, F. F.; Furquin, T. A. C.; Melo, C. S.

2011-07-01

Teams computed tomography (CT) contain the current automatic control of exposure (CAE) which vary from the current X-ray tube in clinical protocols and deliver lower doses than those with fixed current. Alone is not enough control of dose, you need an acceptable image quality ensuring an accurate diagnosis. The TC regulate the flow of two ways: by considering the thickness of the patient and the attenuation by different tissues that intercept the x-ray Besides the advantage, there is the responsibility of proper use of different CAE systems, which require particular knowledge of each manufacturer of the CT.

Mercury Exposure and Heart Diseases

Science.gov (United States)

Genchi, Giuseppe; Sinicropi, Maria Stefania; Carocci, Alessia; Lauria, Graziantonio; Catalano, Alessia

2017-01-01

Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system. PMID:28085104

Mercury Exposure and Heart Diseases.

Science.gov (United States)

Genchi, Giuseppe; Sinicropi, Maria Stefania; Carocci, Alessia; Lauria, Graziantonio; Catalano, Alessia

2017-01-12

Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system.

Mercury Exposure and Heart Diseases

Directory of Open Access Journals (Sweden)

Giuseppe Genchi

2017-01-01

Full Text Available Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system.

Korean Ministry of Environment's web-based visual consumer product exposure and risk assessment system (COPER).

Science.gov (United States)

Lee, Hunjoo; Lee, Kiyoung; Park, Ji Young; Min, Sung-Gi

2017-05-01

With support from the Korean Ministry of the Environment (ME), our interdisciplinary research staff developed the COnsumer Product Exposure and Risk assessment system (COPER). This system includes various databases and features that enable the calculation of exposure and determination of risk caused by consumer products use. COPER is divided into three tiers: the integrated database layer (IDL), the domain specific service layer (DSSL), and the exposure and risk assessment layer (ERAL). IDL is organized by the form of the raw data (mostly non-aggregated data) and includes four sub-databases: a toxicity profile, an inventory of Korean consumer products, the weight fractions of chemical substances in the consumer products determined by chemical analysis and national representative exposure factors. DSSL provides web-based information services corresponding to each database within IDL. Finally, ERAL enables risk assessors to perform various exposure and risk assessments, including exposure scenario design via either inhalation or dermal contact by using or organizing each database in an intuitive manner. This paper outlines the overall architecture of the system and highlights some of the unique features of COPER based on visual and dynamic rendering engine for exposure assessment model on web.

Positive enteric contrast material for abdominal and pelvic CT with automatic exposure control: What is the effect on patient radiation exposure?

Energy Technology Data Exchange (ETDEWEB)

Wang, Zhen J., E-mail: jane.wang@radiology.ucsf.edu [Department of Radiology, University of California San Francisco, 505 Parnassus Avenue, San Francisco, CA 94143-0628 (United States); Chen, Katherine S.; Gould, Robert; Coakley, Fergus V.; Fu Yanjun; Yeh, Benjamin M. [Department of Radiology, University of California San Francisco, 505 Parnassus Avenue, San Francisco, CA 94143-0628 (United States)

2011-08-15

Objective: To assess the effect of positive enteric contrast administration on automatic exposure control (AEC) CT radiation exposure in (1) a CT phantom, and (2) a retrospective review of patients. Materials and methods: We scanned a CT phantom containing simulated bowel that was sequentially filled with water and positive enteric contrast, and recorded the mean volume CT dose index (CTDIvol). We also identified 17 patients who had undergone 2 technically comparable CT scans of the abdomen and pelvis, one with positive enteric contrast and the other with oral water. Paired Student's t-tests were used to compare the mean CTDIvol between scans performed with and without positive enteric contrast. Both the phantom and patient CT scans were performed using AEC with a fixed noise index. Results: The mean CTDIvol for the phantom with simulated bowel containing water and positive enteric contrast were 8.2 {+-} 0.2 mGy, and 8.7 {+-} 0.1 mGy (6.1% higher than water, p = 0.02), respectively. The mean CTDIvol for patients scanned with oral water and with positive enteric contrast were 11.8 mGy and 13.1 mGy, respectively (p = 0.003). This corresponded to a mean CTDIvol which was 11.0% higher (range: 0.0-20.7% higher) in scans with positive enteric contrast than those with oral water in patients. Conclusions: When automatic exposure control is utilized for abdominopelvic CT, the radiation exposure, as measured by CTDIvol, is higher for scans performed with positive enteric contrast than those with oral water.

[Assessment of the surgeon radiation exposure during a minimally invasive TLIF: Comparison between fluoroscopy and O-arm system].

Science.gov (United States)

Grelat, M; Zairi, F; Quidet, M; Marinho, P; Allaoui, M; Assaker, R

2015-08-01

Transforaminal lumbar interbody fusion with a minimally invasive approach (MIS TLIF) has become a very popular technique in the treatment of degenerative diseases of the lumbar spine, as it allows a decrease in muscle iatrogenic. However, iterative radiological controls inherent to this technique are responsible for a significant increase in exposure to ionizing radiation for the surgeon. New techniques for radiological guidance (O-arm navigation-assisted) would overcome this drawback, but this remains unproven. To analyze the exposure of the surgeon to intraoperative X-ray during a MIS TLIF under fluoroscopy and under O-arm navigation-assisted. This prospective study was conducted at the University Hospital of Lille from February to May 2013. Twelve patients underwent a MIS TLIF for the treatment of low-grade spondylolisthesis; six under standard fluoroscopy (group 1) and six under O-arm system (group 2). Passive dosimeters (rings and glasses) and active dosimeters for thorax were used to measure the radiation exposure of the surgeon. For group 1, the average time of fluoroscopy was 3.718 minutes (3.13-4.56) while no radioscopy was perform on group 2. For the first group, the average exposure dose was 12 μSv (5-20 μSv) on the thorax, 1168 μSv (510-2790 μSv) on the main hand and 179 μSv (103-486 μSv) on the lens. The exposure dose was measured zero on the second group. The maximum recommended doses can be reached, mainly for the lens. In addition to the radioprotection measures, O-arm navigation systems are safe alternatives to significantly reduce surgeon exposure. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Copper-Based Aquatic Algaecide Adsorption and Accumulation Kinetics: Influence of Exposure Concentration and Duration for Controlling the Cyanobacterium Lyngbya wollei.

Science.gov (United States)

Bishop, West M; Lynch, Clayton L; Willis, Ben E; Cope, W Gregory

2017-09-01

Filamentous mat-forming cyanobacteria are increasingly impairing uses of freshwater resources. To effectively manage, a better understanding of control measures is needed. Copper (Cu)-based algaecide formulations are often applied to reactively control nuisance cyanobacterial blooms. This laboratory research assessed typical field exposure scenarios for the ability of Cu to partition to, and accumulate in Lyngbya wollei. Exposure factors (Cu concentration × duration) of 4, 8, 16, 24, 32 h were tested across three aqueous Cu concentrations (1, 2, 4 ppm). Results indicated that internally accumulated copper correlated with control of L. wollei, independent of adsorbed copper. L. wollei control was determined by filament viability and chlorophyll a concentrations. Similar exposure factors elicited similar internalized copper levels and consequent responses of L. wollei. Ultimately, a "concentration-exposure-time" (CET) model was created to assist water resource managers in selecting an appropriate treatment regime for a specific in-water infestation. By assessing the exposure concentration and duration required to achieve the internal threshold of copper (i.e., critical burden) that elicits control, water management objectives can be achieved while simultaneously decreasing the environmental loading of copper and potential for non-target species risks.

Minicomputer controlled test system for process control and monitoring systems

International Nuclear Information System (INIS)

Worster, L.D.

A minicomputer controlled test system for testing process control and monitoring systems is described. This system, in service for over one year, has demonstrated that computerized control of such testing has a real potential for expanding the scope of the testing, improving accuracy of testing, and significantly reducing the time required to do the testing. The test system is built around a 16-bit minicomputer with 12K of memory. The system programming language is BASIC with the addition of assembly level routines for communication with the peripheral devices. The peripheral devices include a 100 channel scanner, analog-to-digital converter, visual display, and strip printer. (auth)

Prototype exposure chamber of radon for animal experiments

Energy Technology Data Exchange (ETDEWEB)

Yamada, Yuji; Koizumi, Akira; Yonehara, Hidenori; Shimo, Michikuni; Inaba, Jiro [National Institute of Radiological Sciences, Chiba (Japan)

1998-12-31

To evaluate a dose conversion factor from the `Working Level of Month` (WLM) of radon to the absorbed dose (mGy), the quality of radon and its progeny was assessed, and exposures controlled for each deposition region were planed as follows: 1) exposure of radon gas to the entire respiratory tract, 2) exposure of `unattached` fractions to the upper respiratory tract, 3) exposure of `attached` fractions onto ultrafine particles to the deep lung, 4) exposure of `attached` fractions onto fine particles to the lower respiratory tract, 5) exposure of `attached` fractions onto coarse particles to the upper respiratory tract. In this preliminary study, a prototype exposure system of radon and its progeny for small rodents was designed. A whole body exposure chamber with a volume of about 0.5 m{sup 3} was used, which it held 20 rats. The aging and mixing chamber separated by the exposure chamber had a volume of about 1 m{sup 3}. As career aerosols of radon progeny, carnauba wax aerosols as solid particles, DOS aerosols as liquid particles and NaCl aerosols as hygroscopic particles were selected. These aerosols generated using a vaporization-condensation method and/or an electrical classification method were almost monodisperse with {sigma}{sub g} of <1.2. The monitoring data on biologically related gases showed an importance in the oxygen injection system and the carbon dioxide absorption system. (author)

Optimization of radiation protection for the control of occupational exposure

International Nuclear Information System (INIS)

Esseyin, S.S.

2012-04-01

This project work provides practical information on how to apply the optimization of protection in the workplace. The principle of optimization states that, all reasonable efforts be made to reduce doses, social and economic factors being taken into account. The main objectives of this project work is to limit the risk to health arising from exposure to ionizing radiation in the workplace and to optimize radiation protection was achieved by setting common essential requirements for the control of exposure to radiation, including the specification of employer and employee duties. The acronym ALARA has been used in this project work as it brings to mind the twin concepts of dose reduction and reasonableness. The other main component of this project work is a general review of the means that are likely to be available in most workplaces to reduce exposure. These are divided into global means, which can be applied throughout an organization and those that are more jobs specific. Some of these global means are no more than would be expected in any well managed organization, such as an application of effective and efficient procedures for the management of work and provision for the education and training of workers. (author)

Modification of the striatal dopaminergic neuron system by carbon monoxide exposure in free-moving rats, as determined by in vivo brain microdialysis

Energy Technology Data Exchange (ETDEWEB)

Hara, Shuichi; Kurosaki, Kunihiko; Kuriiwa, Fumi; Endo, Takahiko [Department of Forensic Medicine, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402 (Japan); Mukai, Toshiji [Department of Legal Medicine, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa 216-0015 (Japan)

2002-10-01

Acute carbon monoxide (CO) intoxication in humans results in motor deficits, which resemble those in Parkinson's disease, suggesting possible disturbance of the central dopaminergic (DAergic) neuronal system by CO exposure. In the present study, therefore, we explored the effects of CO exposure on the DAergic neuronal system in the striatum of freely moving rats by means of in vivo brain microdialysis. Exposure of rats to CO (up to 0.3%) for 40 min caused an increase in extracellular dopamine (DA) levels and a decrease in extracellular levels of its major metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), in the striatum depending on the CO concentration. Reoxygenation following termination of the CO exposure resulted in a decline of DA to the control level and an overshoot in the recovery of DOPAC and HVA to levels higher than the control. A monoamine oxidase type A (MAO-A) inhibitor, clorgyline, significantly potentiated the CO-induced increase in DA and completely abolished the subsequent overshoot in the recovery of DOPAC and HVA. Tetrodotoxin, a Na{sup +} channel blocker, completely abolished both the CO-induced increase in DA and the overshoot of DOPAC and HVA. A DA uptake inhibitor, nomifensine, strongly potentiated the CO-induced increase in DA without affecting the subsequent overshoot of DOPAC and HVA. Clorgyline further potentiated the effect of nomifensine on the CO-induced increase in DA, although a slight overshoot of DOPAC and HVA appeared. These findings suggest that (1) CO exposure may stimulate Na{sup +}-dependent DA release in addition to suppressing DA metabolism, resulting in a marked increase in extracellular DA in rat striatum, and (2) CO withdrawal and subsequent reoxygenation may enhance the oxidative metabolism, preferentially mediated by MAO-A, of the increased extracellular DA. In the light of the neurotoxicity of DA per se and reactive substances, such as quinones and activated oxygen species

Exposure to lateral collision in signalized intersections with protected left turn under different traffic control strategies.

Science.gov (United States)

Midenet, Sophie; Saunier, Nicolas; Boillot, Florence

2011-11-01

This paper proposes an original definition of the exposure to lateral collision in signalized intersections and discusses the results of a real world experiment. This exposure is defined as the duration of situations where the stream that is given the right-of-way goes through the conflict zone while road users are waiting in the cross-traffic approach. This measure, obtained from video sensors, makes it possible to compare different operating conditions such as different traffic signal strategies. The data from a real world experiment is used, where the adaptive real-time strategy CRONOS (ContRol Of Networks by Optimization of Switchovers) and a time-plan strategy with vehicle-actuated ranges alternately controlled an isolated intersection near Paris. Hourly samples with similar traffic volumes are compared and the exposure to lateral collision is different in various areas of the intersection and various traffic conditions for the two strategies. The total exposure under peak hour traffic conditions drops by roughly 5 min/h with the CRONOS strategy compared to the time-plan strategy, which occurs mostly on entry streams. The results are analyzed through the decomposition of cycles in phase sequences and recommendations are made for traffic control strategies. Copyright © 2011 Elsevier Ltd. All rights reserved.

Bulgarian National System for Ionization Radiation Control in the Biosphere. Three basic principles, main features and specific aspects of application

International Nuclear Information System (INIS)

Vasilev, G.

1994-01-01

Some problems concerned with the structure of the national system for radiation control and 'de facto' situation in Bulgaria are outlined. The following three basic principles of such a system are discussed: 1. Radioecological principle; 2. Regulatory principle. Maximum permissible contamination level and exposure; 3. Control principle. Local variations of natural radiation background. 1 tab., 12 refs

A national control system

International Nuclear Information System (INIS)

Larsson, A.

1975-01-01

An effective control of nuclear fissionable material is dependent on three different kinds of control, the industry - laboratory management, a national control system and an international safeguards system. The national systems of control differ greatly between various industrialized countries. Two principal reasons for fact can be mentioned. The type and the amounts for nuclear material may be different depending upon the stage of development of the nuclear industry in the country in question. Another reason may be that the country may wish to establish a very elaborate national system of control in order to minimize the IAEA control as much as possible. The two safeguards agreements between the Agency and Sweden on one hand and the Agency and Japan on the other hand can serve as examples for the understanding of the latitude of the IAEA safeguards system under NPT due to the influence of the national control system. If it thus is apparent that the national control system is strongly interrelated to the international safeguards system it is equally influenced by the control and accountancy systems which exist at the nuclear plants and development laboratories. A detailed study of national control systems and their relations to plant management control would fall outside the scope of this article. Some important features will however be examined. (author)

Self-reported exposure to pesticides in residential settings and risk of breast cancer: a case-control study

Directory of Open Access Journals (Sweden)

Graber Nora J

2010-06-01

Full Text Available Abstract Background Pesticides are widely used in households to control insects and weeds. Several studies, over the past decades, have examined the possible relationship of serum concentration of organochlorine pesticides and the development of breast cancer. However, little data exists regarding an association between self-reported, residential exposure to pesticides and breast cancer risk. We, therefore, present a case-control study examining self-reported exposure to household pesticides with regard to associated risk of breast cancer. Methods This study was conducted in the area in and around New York City, NY and included 1205 patients (447 cases and 758 controls. Cases were defined as women with newly diagnosed breast cancer or carcinoma in-situ, while controls included women with benign breast diseases or those undergoing non-breast related surgery. All patients were asked a series of questions to determine their pesticide exposure, including the type of pesticide, location of exposure (inside vs. outside the home, who applied the pesticide (self vs. a professional and duration of pesticide use. Logistic regression models were used to estimate unadjusted and adjusted odds ratios (OR and corresponding 95% confidence intervals (CI. Results The most common pests encountered in participants' homes were ants, carpenter ants, and cockroaches. The calculated adjusted odds ratios for both self and professionally applied pesticides, specifically against the above mentioned insects, with regard to breast cancer risk were 1.25 (95% CI: 0.79-1.98 and 1.06 (95% CI: 0.65-1.73, respectively. Similarly, odds ratios and confidence intervals were calculated for other types of pesticides. Conclusions Overall, the results of our study did not show an association between self-reported exposure to pesticides and breast cancer risk. Future studies, utilizing a larger sample size and more specific detail on time frame of pesticide exposure, are needed to

Patient dose, gray level and exposure index with a computed radiography system

Science.gov (United States)

Silva, T. R.; Yoshimura, E. M.

2014-02-01

Computed radiography (CR) is gradually replacing conventional screen-film system in Brazil. To assess image quality, manufactures provide the calculation of an exposure index through the acquisition software of the CR system. The objective of this study is to verify if the CR image can be used as an evaluator of patient absorbed dose too, through a relationship between the entrance skin dose and the exposure index or the gray level values obtained in the image. The CR system used for this study (Agfa model 30-X with NX acquisition software) calculates an exposure index called Log of the Median (lgM), related to the absorbed dose to the IP. The lgM value depends on the average gray level (called Scan Average Level (SAL)) of the segmented pixel value histogram of the whole image. A Rando male phantom was used to simulate a human body (chest and head), and was irradiated with an X-ray equipment, using usual radiologic techniques for chest exams. Thermoluminescent dosimeters (LiF, TLD100) were used to evaluate entrance skin dose and exit dose. The results showed a logarithm relation between entrance dose and SAL in the image center, regardless of the beam filtration. The exposure index varies linearly with the entrance dose, but the angular coefficient is beam quality dependent. We conclude that, with an adequate calibration, the CR system can be used to evaluate the patient absorbed dose.

Studies on the calibration of mammography automatic exposure mode with computed radiology

International Nuclear Information System (INIS)

Zhu Hongzhou; Shao Guoliang; Shi Lei; Liu Qing

2010-01-01

Objective: To realize the optimization of image quality and radiation dose by correcting mammography automatic exposure, according to automatic exposure controlled mode of mammography film-screen system. Methods: The film-screen system (28 kV) was applied to perform automatic exposure of plexiglass (40 mm) and get the standard dose of exposure, the exposure mode of CR base on LgM=2.0 was rectified, which was divided into 10 steps. Mammary glands pattern (Fluke NA18-220) were examined with CR (26, 28, and 30 kV) by the automatic exposure mode corrected. The exposure values (mAs) were recorded. CR image was diagnosed and evaluated in double blind way by 4 radiologists according to American Collage of Radiology (ACR) standard. Results: Based on the standard of CR automatic exposure with the dose higher than the traditional exposure of film-screen system, the calibration of mammography automatic exposure was accomplished. The test results of the calibrated mode was better than the scoring system of ACR. Conclusions: Comparative study showed improvement in acquiring high-quality image and reduction of radiation dose. The corrected mammography automatic exposure mode might be a better method for clinical use. (authors)

Human reproductive system disturbances and pesticide exposure in Brazil

Directory of Open Access Journals (Sweden)

Koifman Sergio

2002-01-01

Full Text Available The observation of reproductive disturbances in humans and in the wildlife has been reported in the last decade in different countries. Exposure to different chemicals possibly acting in the endocrine system or endocrine disruptors, including pesticides, has been a hypothesis raised to explain the observed changes. This paper aimed to present results of an epidemiological ecologic study carried out to explore population data on pesticides exposure in selected Brazilian states in the eighties and human reproductive outcomes in the nineties. Pearson correlation coefficients were ascertained between available data pesticides sales in eleven states in Brazil in 1985 and selected further reproductive outcomes or their surrogates. Moderate to high correlations were observed to infertility, testis, breast, prostate and ovarian cancer mortality. Despite the restrains of ecologic studies to establish cause-effect relationships, the observed results are in agreement with evidence supporting a possible association between pesticides exposure and the analyzed reproductive outcomes.

Exposure to predator odor influences the relative use of multiple memory systems: role of basolateral amygdala.

Science.gov (United States)

Leong, Kah-Chung; Packard, Mark G

2014-03-01

In a dual-solution plus-maze task in which both hippocampus-dependent place learning and dorsolateral striatal-dependent response learning provide an adequate solution, the relative use of multiple memory systems can be influenced by emotional state. Specifically, pre-training peripheral or intra-basolateral (BLA) administration of anxiogenic drugs result in the predominant use of response learning. The present experiments were designed to extend these findings by examining whether exposure to a putatively ethologically valid stressor would also produce a predominant use of response learning. In experiment 1, adult male Long-Evans rats were exposed to either a predator odor (trimethylthiazoline [TMT], a component of fox feces) or distilled water prior to training in a dual-solution water plus maze task. On a probe trial 24h following task acquisition, rats previously exposed to TMT predominantly displayed response learning relative to control animals. In experiment 2, rats trained on a single-solution plus maze task that required the use of response learning displayed enhanced acquisition following pre-training TMT exposure. In experiment 3, rats exposed to TMT or distilled water were trained in the dual-solution task and received post-training intra-BLA injections of the sodium channel blocker bupivacaine (1.0% solution, 0.5 μl) or saline. Relative to control animals, rats exposed to TMT predominantly displayed response learning on the probe trial, and this effect was blocked by neural inactivation of the BLA. The findings indicate that (1) the use of dorsal striatal-dependent habit memory produced by emotional arousal generalizes from anxiogenic drug administration to a putatively ecologically valid stressor (i.e. predator odor), and (2) the BLA mediates the modulatory effect of exposure to predator odor on the relative use of multiple memory systems. Copyright © 2013 Elsevier Inc. All rights reserved.

The role of tobacco-specific media exposure, knowledge, and smoking status on selected attitudes toward tobacco control.

Science.gov (United States)

Blake, Kelly D; Viswanath, K; Blendon, Robert J; Vallone, Donna

2010-02-01

In August 2007, the President's Cancer Panel urged the leadership of the nation to "summon the political will to address the public health crisis caused by tobacco use" (President's Cancer Panel, N, 2007, Promoting healthy lifestyles: Policy, program, and personal recommendations for reducing cancer risk. http://deainfo.nci.nih.gov/advisory/pcp/pcp07rpt/pcp07rpt.pdf). While some research has examined predictors of public support for tobacco control measures, little research has examined modifiable factors that may influence public attitudes toward tobacco control. We used the American Legacy Foundation's 2003 American Smoking and Health Survey 2 to examine the contribution of smoking status, knowledge of the negative effects of tobacco, and tobacco-specific media exposure (antitobacco messages, news coverage of tobacco issues, and protobacco advertising) on U.S. adults' attitudes toward tobacco control. In addition, we assessed whether smoking status moderates the relationship between tobacco-specific media exposure and policy attitudes. Weighted multivariable logistic regression models were employed. Results suggest that knowledge of the negative effects of tobacco and smoking status are associated with attitudes toward tobacco control and that exposure to tobacco-specific information in the media plays a role only in some instances. We found no evidence of effect modification by smoking status on the impact of exposure to tobacco-specific media on attitudes toward tobacco control. Understanding the impact of readily modifiable factors that shape policy attitudes is essential if we are to target outreach and education in a way that is likely to sway public support for tobacco control.

The design, construction and application of time varying magnetic exposure system

International Nuclear Information System (INIS)

El-Din, S.A.A.; Saad, H.M.; Said, H.H.

2000-01-01

An exposure system has been designed and constructed to study the probable biological effects of a-50-Hz alternating field on mice. The system is in the form of a cooled water wooden cage that can accommodate 12 mice at a time. The cage is enclosed into an electromagnet consists of three parallel closely connected rectangular coils able to induce a magnetic field of an intensity up to 200 Gauss. The derivation of the equations to define the spatial distribution of the field due to the currents in the coils is presented. A computer program with basic language is suggested to calculate the field strength into the cage. A comparison is made between these computed values and the corresponding measured ones. A representative experiment was carried out where three mice groups were exposed one for 3 h/day the others were repeated for two days and three days respectively. A change was found in hemoglobin spectrum in comparison with the control group has been noticed. This result can be attributed to the change of the spin states of the heme-iron

Low level exposure to chemicals and immune system

International Nuclear Information System (INIS)

Colosio, C.; Birindelli, S.; Corsini, E.; Galli, C.L.; Maroni, M.

2005-01-01

Industrialized countries are facing an increase of diseases attributable to an alteration of the immune system function, and concern is growing that this trend could be at least partially attributable to new and modified patterns of exposure to chemicals. Among chemicals matter of concern, pesticides can be included. The Authors have reviewed the existing evidence of pesticide immunotoxicity in humans, showing that existing data are inadequate to raise conclusions on the immunotoxic risk related to these compounds. The limits of existing studies are: poor knowledge on exposure levels, heterogeneity of the approach, and difficulty in giving a prognostic significance to the slight changes often observed. To overcome these limits, the Authors have proposed a tier approach, based on three steps: the first, addressed at pointing out a possible immunomodulation; the second, at refining the results and the third one, when needed, to finalize the study and to point out concordance with previous results. Studies should preferably be carried out through comparison of pre- and post-exposure findings in the same groups of subjects to be examined immediately after the end of the exposure. A simplification of the first step approach can be used by the occupational health physician and the occupational toxicologist. Conclusions on the prognostic significance of the slight changes often observed will be reached only by validating the hypothesis generated by field studies with an epidemiological approach. In this field, the most useful option is represented by longitudinal perspective studies

Management of Control System Information SecurityI: Control System Patch Management

Energy Technology Data Exchange (ETDEWEB)

Quanyan Zhu; Miles McQueen; Craig Rieger; Tamer Basar

2011-09-01

The use of information technologies in control systems poses additional potential threats due to the frequent disclosure of software vulnerabilities. The management of information security involves a series of policy-making on the vulnerability discovery, disclosure, patch development and patching. In this paper, we use a system approach to devise a model to understand the interdependencies of these decision processes. In more details, we establish a theoretical framework for making patching decision for control systems, taking into account the requirement of functionability of control systems. We illustrate our results with numerical simulations and show that the optimal operation period of control systems given the currently estimated attack rate is roughly around a half a month.

Dynamic Systems and Control Engineering

International Nuclear Information System (INIS)

Kim, Jong Seok

1994-02-01

This book deals with introduction of dynamic system and control engineering, frequency domain modeling of dynamic system, temporal modeling of dynamic system, typical dynamic system and automatic control device, performance and stability of control system, root locus analysis, analysis of frequency domain dynamic system, design of frequency domain dynamic system, design and analysis of space, space of control system and digital control system such as control system design of direct digital and digitalization of consecutive control system.

Dynamic Systems and Control Engineering

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Seok

1994-02-15

This book deals with introduction of dynamic system and control engineering, frequency domain modeling of dynamic system, temporal modeling of dynamic system, typical dynamic system and automatic control device, performance and stability of control system, root locus analysis, analysis of frequency domain dynamic system, design of frequency domain dynamic system, design and analysis of space, space of control system and digital control system such as control system design of direct digital and digitalization of consecutive control system.

Heavy Metal Exposure and Metabolic Syndrome: Evidence from Human and Model System Studies.

Science.gov (United States)

Planchart, Antonio; Green, Adrian; Hoyo, Cathrine; Mattingly, Carolyn J

2018-03-01

Metabolic syndrome (MS) describes the co-occurrence of conditions that increase one's risk for heart disease and other disorders such as diabetes and stroke. The worldwide increase in the prevalence of MS cannot be fully explained by lifestyle factors such as sedentary behavior and caloric intake alone. Environmental exposures, such as heavy metals, have been implicated, but results are conflicting and possible mechanisms remain unclear. To assess recent progress in determining a possible role between heavy metal exposure and MS, we reviewed epidemiological and model system data for cadmium (Cd), lead (Pb), and mercury (Hg) from the last decade. Data from 36 epidemiological studies involving 17 unique countries/regions and 13 studies leveraging model systems are included in this review. Epidemiological and model system studies support a possible association between heavy metal exposure and MS or comorbid conditions; however, results remain conflicting. Epidemiological studies were predominantly cross-sectional and collectively, they highlight a global interest in this question and reveal evidence of differential susceptibility by sex and age to heavy metal exposures. In vivo studies in rats and mice and in vitro cell-based assays provide insights into potential mechanisms of action relevant to MS including altered regulation of lipid and glucose homeostasis, adipogenesis, and oxidative stress. Heavy metal exposure may contribute to MS or comorbid conditions; however, available data are conflicting. Causal inference remains challenging as epidemiological data are largely cross-sectional; and variation in study design, including samples used for heavy metal measurements, age of subjects at which MS outcomes are measured; the scope and treatment of confounding factors; and the population demographics vary widely. Prospective studies, standardization or increased consistency across study designs and reporting, and consideration of molecular mechanisms informed by model

Quality control procedures of dental diagnostic radiology systems

International Nuclear Information System (INIS)

Andrade, Paula Serra Sasaki

2007-01-01

This work presents quality control reference procedures for dental diagnostic radiology systems, following the recommendations of the Publication 453 of the Brazilian Health Ministry (PF453), to be applied in dental clinics, in order to achieve an improvement in the radiological image qualities and the patient dose reduction. All tests were applied in an intraoral X rays system, following the methodology developed and the requirements of the PF 453. In order to verify the best quality of the image in relation to the smaller exposition time an object test was also developed in this work. The use of this object allowed the reduction of the exposition time of 0.5 seconds, the maximum value of the linear region of the characteristic curve, for 0.2 seconds. The tested X rays system showed a very good agreement with the applied procedures, detaching the reduction of the skin entrance dose using the film-holding devices. However, the size of the field increased and exceeded the maximum value of 6 cm recommended in the standard. The importance of the quality control in dental diagnostic radiology systems is essential due to the constant use of X radiation in dental clinics. The PF453 recommends the frequency of at least two years for the constancy tests. However, it is suggested that the professional, surgeon-dentist, should be responsible for the internal control of the image quality obtained from the X rays device. This can be done through monthly exposures of the object test developed in this work. (author)

Parenteral exposure to pesticides and occurence of congenital malformations: hospital-based case-control study.

Science.gov (United States)

Ueker, Marly Eliane; Silva, Vivianne Monteiro; Moi, Gisele Pedroso; Pignati, Wanderley Antonio; Mattos, Ines Echenique; Silva, Ageo Mário Cândido

2016-08-12

Most fetal defects are associated with genetic and environmental causes, among them, exposure of pregnant women to intensive pesticide use. Agribusiness is the economic basis of the state of Mato Grosso, the largest consumer of pesticides of all Brazilian states. The objective of this study was to investigate the association between past parental exposure to pesticides and the occurrence of congenital malformations in children in Mato Grosso, Brazil. This hospital-based case-control study was conducted in Cuiabá, the capital of Mato Grosso, from March to October 2011. Data was collected in all public, private, and health plan referral hospitals that provide care for pregnant women in the state of Mato Grosso and were situated in Cuiabá. Cases were children under 5 years of age with congenital malformations classified in Chapter XVIII of the International Classification of Diseases-10 and controls were children within the same age range, without congenital malformations, treated at the same hospitals. Malformation-related data was obtained from the patients' medical records. Socioeconomic data and information about parental exposure to pesticides were obtained in an interview with the mother using a standardized questionnaire. We conducted multivariate logistic regression to assess the relation between parent report of past pesticide use and congenital malformations. We also assessed effect modification to verify whether low maternal education level modified the association between exposure and our outcome. We observed positive effect modification of the association of paternal past exposure to pesticide and congenital malformation in the offspring by maternal education for mothers with low educational level (OR = 8.40, 95 % CI 2.17-32.52), father's work related to farming (OR = 4.65, 95 % CI 1.03-20.98) and paternal past exposure to pesticides (OR = 4.15, 95 % CI 1.24-13.66). These findings provide further evidence that paternal exposure to

Effects of nasal corticosteroids on boosts of systemic allergen-specific IgE production induced by nasal allergen exposure.

Directory of Open Access Journals (Sweden)

Cornelia Egger

Full Text Available Allergen exposure via the respiratory tract and in particular via the nasal mucosa boosts systemic allergen-specific IgE production. Intranasal corticosteroids (INCS represent a first line treatment of allergic rhinitis but their effects on this boost of allergen-specific IgE production are unclear.Here we aimed to determine in a double-blind, placebo-controlled study whether therapeutic doses of an INCS preparation, i.e., nasal fluticasone propionate, have effects on boosts of allergen-specific IgE following nasal allergen exposure.Subjects (n = 48 suffering from grass and birch pollen allergy were treated with daily fluticasone propionate or placebo nasal spray for four weeks. After two weeks of treatment, subjects underwent nasal provocation with either birch pollen allergen Bet v 1 or grass pollen allergen Phl p 5. Bet v 1 and Phl p 5-specific IgE, IgG1-4, IgM and IgA levels were measured in serum samples obtained at the time of provocation and one, two, four, six and eight weeks thereafter.Nasal allergen provocation induced a median increase to 141.1% of serum IgE levels to allergens used for provocation but not to control allergens 4 weeks after provocation. There were no significant differences regarding the boosts of allergen-specific IgE between INCS- and placebo-treated subjects.In conclusion, the application of fluticasone propionate had no significant effects on the boosts of systemic allergen-specific IgE production following nasal allergen exposure.http://clinicaltrials.gov/NCT00755066.

Automatic control systems engineering

International Nuclear Information System (INIS)

Shin, Yun Gi

2004-01-01

This book gives descriptions of automatic control for electrical electronics, which indicates history of automatic control, Laplace transform, block diagram and signal flow diagram, electrometer, linearization of system, space of situation, state space analysis of electric system, sensor, hydro controlling system, stability, time response of linear dynamic system, conception of root locus, procedure to draw root locus, frequency response, and design of control system.

Control and automation systems

International Nuclear Information System (INIS)

Schmidt, R.; Zillich, H.

1986-01-01

A survey is given of the development of control and automation systems for energy uses. General remarks about control and automation schemes are followed by a description of modern process control systems along with process control processes as such. After discussing the particular process control requirements of nuclear power plants the paper deals with the reliability and availability of process control systems and refers to computerized simulation processes. The subsequent paragraphs are dedicated to descriptions of the operating floor, ergonomic conditions, existing systems, flue gas desulfurization systems, the electromagnetic influences on digital circuits as well as of light wave uses. (HAG) [de

Prenatal exposure to systemic antibacterials and overweight and obesity in Danish schoolchildren

DEFF Research Database (Denmark)

Mor, A; Antonsen, S; Kahlert, J

2015-01-01

BACKGROUND/OBJECTIVE: Prenatal exposure to antibacterials may permanently dysregulate fetal metabolic patterns via epigenetic pathways or by altering maternal microbiota. We examined the association of prenatal exposure to systemic antibacterials with overweight and obesity in schoolchildren...... admissions during pregnancy. We defined overweight and obesity among the children using standard age- and sex-specific cutoffs. We computed sex-specific adjusted prevalence ratios (aPRs) of overweight and obesity associated with exposure to prenatal antibacterials, adjusting for maternal age at delivery....... SUBJECTS/METHODS: We conducted a prevalence study among Danish schoolchildren aged 7-16 years using data from routine school anthropometric evaluations conducted during 2002-2013. Prenatal exposure to antibacterials was ascertained by using maternal prescription dispensations and infection-related hospital...

Control system design guide

Energy Technology Data Exchange (ETDEWEB)

Sellers, David; Friedman, Hannah; Haasl, Tudi; Bourassa, Norman; Piette, Mary Ann

2003-05-01

The ''Control System Design Guide'' (Design Guide) provides methods and recommendations for the control system design process and control point selection and installation. Control systems are often the most problematic system in a building. A good design process that takes into account maintenance, operation, and commissioning can lead to a smoothly operating and efficient building. To this end, the Design Guide provides a toolbox of templates for improving control system design and specification. HVAC designers are the primary audience for the Design Guide. The control design process it presents will help produce well-designed control systems that achieve efficient and robust operation. The spreadsheet examples for control valve schedules, damper schedules, and points lists can streamline the use of the control system design concepts set forth in the Design Guide by providing convenient starting points from which designers can build. Although each reader brings their own unique questions to the text, the Design Guide contains information that designers, commissioning providers, operators, and owners will find useful.

Indirect control of quantum systems via an accessor: pure coherent control without system excitation

International Nuclear Information System (INIS)

Fu, H C; Dong Hui; Sun, C P; Liu, X F

2009-01-01

A pure indirect control of quantum systems via a quantum accessor is investigated. In this control scheme, we do not apply any external classical excitation fields on the controlled system and we control a quantum system via a quantum accessor and classical control fields control the accessor only. Complete controllability is investigated for arbitrary finite-dimensional quantum systems and exemplified by two- and three-dimensional systems. The scheme exhibits some advantages; it uses less qubits in the accessor and does not depend on the energy-level structure of the controlled system

Systemic immune cell response in rats after pulmonary exposure to manganese-containing particles collected from welding aerosols.

Science.gov (United States)

Antonini, James M; Zeidler-Erdely, Patti C; Young, Shih-Houng; Roberts, Jenny R; Erdely, Aaron

2012-01-01

Welding fume inhalation affects the immune system of exposed workers. Manganese (Mn) in welding fume may induce immunosuppressive effects. The goal was to determine if Mn in welding fume alters immunity by reducing the number of circulating total leukocytes and specific leukocyte sub-populations. Sprague-Dawley rats were treated by intratracheal instillation (ITI) with either a single dose (2.00 mg/rat) or repeated doses (0.125 or 2.00 mg/rat for 7 weeks) with welding fumes that contained different levels of Mn. Additional rats were treated by ITI once a week for 7 weeks with the two doses of manganese chloride (MnCl₂). Bronchoalveolar lavage was performed to assess lung inflammation. Also, whole blood was recovered, and the number of circulating total leukocytes, as well as specific lymphocyte subsets, was determined by flow cytometry. The welding fume highest in Mn content significantly increased lung inflammation, injury, and production of inflammatory cytokines and chemokines compared to all other treatment groups. In addition, the same group expressed significant decreases in the number of circulating CD4⁺ and CD8⁺ T-lymphocytes after a single exposure, and significant reductions in the number of circulating total lymphocytes, primarily CD4⁺ and CD8⁺ T-lymphocytes, after repeated exposures (compared to control values). Repeated MnCl₂ exposure led to a trend of a reduction (but not statistically significant) in circulating total lymphocytes, attributable to the changes in the CD4⁺ T-lymphocyte population levels. The welding fume with the lower concentration of Mn had no significant effect on the numbers of blood lymphocytes and lymphocyte subsets compared to control values. Evidence from this study indicates that pulmonary exposure to certain welding fumes cause decrements in systemic immune cell populations, specifically circulating T-lymphocytes, and these alterations in immune cell number are not dependent exclusively on Mn, but likely a

Cosmic rays exposure during aircraft flight (3). Guideline and dose evaluation

International Nuclear Information System (INIS)

Yasuda, Hiroshi

2007-01-01

Radiation Council of MEXT drew up the Guideline of Cosmic Ray Exposure Control for Air Crew in 2006. The content of the Guideline and evaluation methods of dose are explained. The Guideline stated five items for Airline Company. It consists of 1) exposure dose control for air crew, 2) evaluation methods of cosmic rays exposure dose of air crew, 3) explanation and education of cosmic rays exposure for air crew, 4) reading, record and store of cosmic rays exposure dose of air crew, and 5) health control of air crew. The doses of four airlines were calculated by the Civil Aeromedical Research Institute (CARI) code and the European Program package for the Calculation of Aviation Route Doses (EPCARD) code. The difference of two codes was about 15 to 25%. Japanese Internet System for Calculation of Aviation Route Doses (JISCAED) has been developed by Japan. (S.Y.)

Medical image information system 2001. Development of the medical image information system to risk management- Medical exposure management

International Nuclear Information System (INIS)

Kuranishi, Makoto; Kumagai, Michitomo; Shintani, Mitsuo

2000-01-01

This paper discusses the methods and systems for optimizing the following supplements 10 and 17 for national health and medical care. The supplements 10 and 17 of DICOM (digital imaging and communications in medicine) system, which is now under progress for the purpose to keep compatibility within medical image information system as an international standard, are important for making the cooperation between HIS (hospital information system)/RIS (radiation information system) and modality (imaging instruments). Supplement 10 concerns the system to send the information of patients and their orders through HIS/RIS to modality and 17, the information of modality performed procedure step (MPPS) to HIS/RIS. The latter defines to document patients' exposure, a part of which has not been recognized in Japan. Thus the medical information system can be useful for risk-management of medical exposure in future. (K.H.)

Medical image information system 2001. Development of the medical image information system to risk management- Medical exposure management

Energy Technology Data Exchange (ETDEWEB)

Kuranishi, Makoto; Kumagai, Michitomo; Shintani, Mitsuo [Toyama Medical and Pharmaceutical Univ. (Japan). Hospital

2000-12-01

This paper discusses the methods and systems for optimizing the following supplements 10 and 17 for national health and medical care. The supplements 10 and 17 of DICOM (digital imaging and communications in medicine) system, which is now under progress for the purpose to keep compatibility within medical image information system as an international standard, are important for making the cooperation between HIS (hospital information system)/RIS (radiation information system) and modality (imaging instruments). Supplement 10 concerns the system to send the information of patients and their orders through HIS/RIS to modality and 17, the information of modality performed procedure step (MPPS) to HIS/RIS. The latter defines to document patients' exposure, a part of which has not been recognized in Japan. Thus the medical information system can be useful for risk-management of medical exposure in future. (K.H.)

Human exposure to endocrine disrupting chemicals: effects on the male and female reproductive systems.

Science.gov (United States)

Sifakis, Stavros; Androutsopoulos, Vasilis P; Tsatsakis, Aristeidis M; Spandidos, Demetrios A

2017-04-01

Endocrine disrupting chemicals (EDCs) comprise a group of chemical compounds that have been examined extensively due to the potential harmful effects in the health of human populations. During the past decades, particular focus has been given to the harmful effects of EDCs to the reproductive system. The estimation of human exposure to EDCs can be broadly categorized into occupational and environmental exposure, and has been a major challenge due to the structural diversity of the chemicals that are derived by many different sources at doses below the limit of detection used by conventional methodologies. Animal and in vitro studies have supported the conclusion that endocrine disrupting chemicals affect the hormone dependent pathways responsible for male and female gonadal development, either through direct interaction with hormone receptors or via epigenetic and cell-cycle regulatory modes of action. In human populations, the majority of the studies point towards an association between exposure to EDCs and male and/or female reproduction system disorders, such as infertility, endometriosis, breast cancer, testicular cancer, poor sperm quality and/or function. Despite promising discoveries, a causal relationship between the reproductive disorders and exposure to specific toxicants is yet to be established, due to the complexity of the clinical protocols used, the degree of occupational or environmental exposure, the determination of the variables measured and the sample size of the subjects examined. Future studies should focus on a uniform system of examining human populations with regard to the exposure to specific EDCs and the direct effect on the reproductive system. Copyright © 2017 Elsevier B.V. All rights reserved.

Intelligent control systems 1990

International Nuclear Information System (INIS)

Shoureshi, R.

1991-01-01

The field of artificial intelligence (Al) has generated many useful ideas and techniques that can be integrated into the design of control systems. It is believed and, for special cases, has been demonstrated, that integration of Al into control systems would provide the necessary tools for solving many of the complex problems that present control techniques and Al algorithms are unable to do, individually. However, this integration requires the development of basic understanding and new fundamentals to provide scientific bases for achievement of its potential. This book presents an overview of some of the latest research studies in the area of intelligent control systems. These papers present techniques for formulation of intelligent control, and development of the rule-based control systems. Papers present applications of control systems in nuclear power plants and HVAC systems

FFTF control system experience

International Nuclear Information System (INIS)

Warrick, R.P.

1981-01-01

The FFTF control systems provide control equipment for safe and efficient operation of the plant. For convenience, these systems will be divided into three parts for discussions: (1) Plant Protection System (PPS); (2) Plant Control System (PCS); and (3) General Observations. Performance of each of these systems is discussed

Development of novel whole-body exposure setups for rats providing high efficiency, National Toxicology Program (NTP) compatibility and well-characterized exposure

Energy Technology Data Exchange (ETDEWEB)

Kainz, Wolfgang [Food and Drug Administration (FDA), Center for Devices and Radiological Health (CDRH), 12725 Twinbrook Parkway, Rockville, MD 20852 (United States); Nikoloski, Neviana [IT' IS Foundation-The Foundation for Research on Information Technologies in Society, ETH Zurich, 8092 Zurich (Switzerland); Oesch, Walter [IT' IS Foundation-The Foundation for Research on Information Technologies in Society, ETH Zurich, 8092 Zurich (Switzerland); Berdinas-Torres, Veronica [IT' IS Foundation-The Foundation for Research on Information Technologies in Society, ETH Zurich, 8092 Zurich (Switzerland); Froehlich, Juerg [IT' IS Foundation-The Foundation for Research on Information Technologies in Society, ETH Zurich, 8092 Zurich (Switzerland); Neubauer, Georg [ARC Seibersdorf research GmbH, Kramergasse 1, A-1010 Vienna (Austria); Kuster, Niels [IT' IS Foundation-The Foundation for Research on Information Technologies in Society, ETH Zurich, 8092 Zurich (Switzerland)

2006-10-21

This paper presents the design, optimization, realization and verification of novel whole-body exposure setups for rats. The setups operating at 902 MHz and 1747 MHz provide highly efficient, National Toxicology Program (NTP) compatible and well-characterized exposures. They are compared to existing concepts of exposure setups with respect to efficiency, induced field uniformity, good laboratory practice (GLP) compatibility and cost. The novel exposure setup consists of a circular cascade of 17 sectorial waveguides excited by a novel loop antenna placed in the centre. The 70% overall efficiency of the exposure setup surpasses comparable values of existing setups. A field uniformity inside the phantom of more than 86% for the 1g cubical averaged specific absorption rate (SAR) within {+-}5 dB of the whole-body SAR (WB-SAR) was attained. The uniformity of the exposure inside the setup, defined as the variation of the WB-SAR between animals, was better than {+-}24%. Using only stainless steel, gold and polycarbonate in the vicinity of the animals ensured full GLP compatibility. The entire exposure system features fully automated computer controlled exposure and data monitoring, data storing and failure handling. Therefore, the proposed exposure system can be used to run blinded large scale, long-term exposure studies.

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.

Case-control study of tobacco smoke exposure and breast cancer risk in Delaware

Directory of Open Access Journals (Sweden)

Hathcock H Leroy

2008-06-01

Full Text Available Abstract Background Tobacco smoke exposure may be associated with increased breast cancer risk, although the evidence supporting the association is inconclusive. We conducted a case-control study in Delaware, incorporating detailed exposure assessment for active and secondhand smoke at home and in the workplace. Methods Primary invasive breast cancer cases diagnosed among female Delaware residents, ages 40–79, in 2000–2002 were identified through the Delaware cancer registry (n = 287. Delaware drivers license and Health Care Finance Administration records were used to select age frequency-matched controls for women Results A statistically significant increased risk of breast cancer was observed for ever having smoked cigarettes (odds ratio = 1.43, 95% confidence interval = 1.03–1.99. However, there was no evidence of a dose-response relationship between breast cancer risk and total years smoked, cigarettes per day, or pack-years. Neither residential nor workplace secondhand smoke exposure was associated with breast cancer. Recalculations of active smoking risks using a purely unexposed reference group of women who were not exposed to active or secondhand smoking did not indicate increased risks of breast cancer. Conclusion These findings do not support an association between smoking and breast cancer.

Entry-Control Systems Handbook

International Nuclear Information System (INIS)

1978-09-01

The function of an entry-control system in a total Physical Protection System is to allow the movement of authorized personnel and material through normal access routes, yet detect and delay unauthorized movement of personnel and material from uncontrolled areas. The ten chapters of this handbook cover: introduction, credentials, personnel identity verification systems, special nuclear materials monitors, metal detectors, explosives sensors, package search systems, criteria for selection of entry-control equipment, machine-aided manual entry-control systems, and automated entry-control systems. A system example and its cost are included as an appendix

Biomarkers, lactate, and clinical scores as outcome predictors in systemic poisons exposures.

Science.gov (United States)

Lionte, C; Sorodoc, V; Tuchilus, C; Cimpoiesu, D; Jaba, E

2017-07-01

Acute exposure to systemic poisons represents an important challenge in clinical toxicology. We aimed to analyze the potential role of cardiac biomarkers, routine laboratory tests, and clinical scores as morbidity and in-hospital mortality predictors in patients intoxicated with various systemic poisons. We conducted a prospective study on adults acutely exposed to systemic poisons. We determined the PSS, Glasgow Coma Scale (GCS), and we performed electrocardiogram, laboratory tests, lactate and cardiac biomarkers (which were reassessed 4 h, respectively 6 h later). Of 120 patients included, 45% developed complications, 19.2% had a poor outcome, and 5% died. Multivariate logistic regression sustained lactate (odds ratio (OR) 1.58; confidence interval (CI) 95%: 0.97-2.59; p 0.066), MB isoenzyme of creatine kinase (6h-CKMB; OR 1.08; CI 95%: 1.02-1.16; p 0.018) as predictors for a poor outcome. A GCS poisons exposure. Receiver operating characteristic analysis showed that brain natriuretic peptide (area under the curve (AUC), 0.96; CI 95%: 0.92-0.99; p poisons exposure.

Assessing the risk to green sturgeon from application of imidacloprid to control burrowing shrimp in Willapa Bay, Washington--Part II: controlled exposure studies.

Science.gov (United States)

Frew, John A; Grue, Christian E

2015-11-01

The activities of 2 species of burrowing shrimp have a negative impact on the growth and survival of oysters reared on intertidal mudflats in Willapa Bay and Grays Harbor, Washington (USA). To maintain viable harvests, oyster growers proposed the application of the neonicotinoid insecticide imidacloprid onto harvested beds for the control of burrowing shrimp. In test applications, water column concentrations of imidacloprid were relatively low and dissipated rapidly. The foraging activities of the green sturgeon (listed in the US Endangered Species Act) could result in exposure to higher, more sustained imidacloprid concentrations within sediment porewater and from the consumption of contaminated shrimp. Controlled experiments were conducted using surrogate white sturgeon to determine acute and chronic effect concentrations, to examine overt effects at more environmentally realistic concentrations and durations of exposure, and to assess chemical depuration. The 96-h median lethal concentration was 124 mg L(-1) , and the predicted 35-d no-observed-adverse-effect concentration was 0.7 mg L(-1) . No overt effects were observed following environmentally relevant exposures. Imidacloprid half-life in plasma was greater than 32 h. Measured concentrations of imidacloprid in porewater were significantly lower than the derived acute and chronic effect concentrations for white sturgeon. Exposure risk quotients were calculated using the effect concentrations and estimated environmental exposure. The resulting values were considerably below the level of concern for direct effects from either acute or chronic exposure to an endangered species. © 2015 SETAC.

In utero exposure to a low concentration of diesel exhaust affects spontaneous locomotor activity and monoaminergic system in male mice

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Odagiri Takashi

2010-03-01

Full Text Available Abstract Background Epidemiological studies have suggested that suspended particulate matter (SPM causes detrimental health effects such as respiratory and cardiovascular diseases, and that diesel exhaust particles from automobiles is a major contributor to SPM. It has been reported that neonatal and adult exposure to diesel exhaust damages the central nervous system (CNS and induces behavioral alteration. Recently, we have focused on the effects of prenatal exposure to diesel exhaust on the CNS. In this study, we examined the effects of prenatal exposure to low concentration of diesel exhaust on behaviour and the monoaminergic neuron system. Spontaneous locomotor activity (SLA and monoamine levels in the CNS were assessed. Methods Mice were exposed prenatally to a low concentration of diesel exhaust (171 μg DEP/m3 for 8 hours/day on gestational days 2-16. SLA was assessed for 3 days in 4-week-old mice by analysis of the release of temperature-associated infrared rays. At 5 weeks of age, the mice were sacrificed and the brains were used for analysis by high-performance liquid chromatography (HPLC. Results and Discussion Mice exposed to a low concentration of diesel exhaust showed decreased SLA in the first 60 minutes of exposure. Over the entire test period, the mice exposed prenatally to diesel exhaust showed decreased daily SLA compared to that in control mice, and the SLA in each 3 hour period was decreased when the lights were turned on. Neurotransmitter levels, including dopamine and noradrenaline, were increased in the prefrontal cortex (PFC in the exposure group compared to the control group. The metabolites of dopamine and noradrenaline also increased in the PFC. Neurotransmitter turnover, an index of neuronal activity, of dopamine and noradrenaline was decreased in various regions of the CNS, including the striatum, in the exposure group. The serum corticosterone level was not different between groups. The data suggest that decreased

Semi-empirical neural network models of controlled dynamical systems

Directory of Open Access Journals (Sweden)

Mihail V. Egorchev

2017-12-01

Full Text Available A simulation approach is discussed for maneuverable aircraft motion as nonlinear controlled dynamical system under multiple and diverse uncertainties including knowledge imperfection concerning simulated plant and its environment exposure. The suggested approach is based on a merging of theoretical knowledge for the plant with training tools of artificial neural network field. The efficiency of this approach is demonstrated using the example of motion modeling and the identification of the aerodynamic characteristics of a maneuverable aircraft. A semi-empirical recurrent neural network based model learning algorithm is proposed for multi-step ahead prediction problem. This algorithm sequentially states and solves numerical optimization subproblems of increasing complexity, using each solution as initial guess for subsequent subproblem. We also consider a procedure for representative training set acquisition that utilizes multisine control signals.

The Effects of Technology Innovativeness and System Exposure on Student Acceptance of E-textbooks

Directory of Open Access Journals (Sweden)

Madison N. Ngafeeson

2015-01-01

Full Text Available The efforts of educators in the last three decades have, among other things, focused on the use of information technology (IT in education. It has become commonplace to view information systems both as an effective carrier of course content as well as a cost-effective tool to improve student learning outcomes. One of such technologies is the e-book. Decision-makers in the education field need make sense of this technological transformation. However, despite the growing popularity of e-books in higher education, its adoption by students is yet to be crystalized. This study exploits the technology acceptance model (TAM framework to examine student acceptance of e-textbooks as “internally” impacted by technology innovativeness and “externally” influenced by system exposure. The results showed that students’ technology innovativeness is associated with student acceptance of e-textbooks and that system exposure was a strong moderator of the TAM relationships. The findings suggest that students’ openness to new technology, in general, is likely to positively affect the adoption of a specific new instructional technology. Additionally, system exposure was found to be a significant moderator of the TAM relationships. It is concluded that students’ technology innovativeness and system exposure must therefore be factored into instructional technology usage decision-making models.

Efforts to reduce exposure at Japanese PWRs: CVCS improvement

Energy Technology Data Exchange (ETDEWEB)

Terada, Ryosuke [Mitsubishi Atomic Power Industries, Inc., Yokohama (Japan)

1995-03-01

Many reports have been focused on the reduction of radiation sources and related occupational exposures. The radiation sources mainly consist of corrosion products. Radiation dose rate is determined by the amount of the activated corrosion products on the surface of the primary loop components of Pressurized Water Reactor (PWR) plants. Therefore, reducing the amount of the corrosion product will contribute to the reduction of occupational exposures. In order to reduce the corrosion products, Chemical and Volume Control System (CVCS) has been improved in Japanese PWRs as follows: (a) Cation Bed Demineralizer Flowrate Control; (b) Hydrogen Peroxide Injection System; (c) Purification Flowrate During Plant Shutdown; (d) Fine Mesh Filters Upstream of Mixed Bed Demineralizers.

Thimerosal exposure and increased risk for diagnosed tic disorder in the United States: a case-control study

Directory of Open Access Journals (Sweden)

Geier David A.

2015-06-01

Full Text Available A hypothesis testing, case-control study evaluated automated medical records for exposure to organic-Hg from Thimerosal-containing hepatitis B vaccines (TM-HepB administered at specific intervals in the first six-months-of-life among cases diagnosed with a tic disorder (TD or cerebral degeneration (CD (an outcome not biologically plausibly linked to TM exposure in comparison to controls; both cases and controls were continuously enrolled from birth (born from 1991–2000 within the Vaccine Safety Datalink (VSD database. TD cases were significantly more likely than controls to have received increased organic-Hg from TM-HepB administered within the first month-of-life (odds ratio (OR=1.59, p<0.00001, first two-months-of-life (OR=1.59, p<0.00001, and first six-months-of-life (OR=2.97, p<0.00001. Male TD cases were significantly more likely than male controls to have received increased organic-Hg from TM-HepB administered within the first month-of-life (OR =1.65, p<0.0001, first two-months-of-life (OR=1.64, p<0.0001, and first six months-of-life (OR=2.47, p<0.05, where as female TD were significantly more likely than female controls to have received increased organic-Hg from TM-HepB administered within the first six-months-of-life (OR=4.97, p<0.05. By contrast, CD cases were no more likely than controls to have received increased organic-Hg exposure from TM-HepB administered at any period studied within the first six-months-of-life. Although routine childhood vaccination is considered an important public health tool to combat infectious diseases, the present study associates increasing organic-Hg exposure from TM-HepB and the subsequent risk of a TD diagnosis.

Childhood physical abnormalities following paternal exposure to sulfur mustard gas in Iran: a case-control study

Directory of Open Access Journals (Sweden)

Khademolhosseini Seyyed M

2010-07-01

Full Text Available Abstract Background Mustard gas, a known chemical weapon, was used during the Iran-Iraq war of 1980-1988. We aimed to determine if exposure to mustard gas among men was significantly associated with abnormalities and disorders among progenies. Methods Using a case-control design, we identified all progenies of Sardasht men (exposed group, n = 498, who were born at least nine months after the exposure, compared to age-matched controls in Rabat, a nearby city (non-exposed group, n = 689. We conducted a thorough medical history, physical examination, and appropriate paraclinical studies to detect any physical abnormality and/or disorder. Given the presence of correlated data, we applied Generalized Estimating Equation (GEE multivariable models to determine associations. Results The overall frequency of detected physical abnormalities and disorders was significantly higher in the exposed group (19% vs. 11%, Odds Ratio [OR] 1.93, 95% Confidence Interval [CI], 1.37-2.72, P = 0.0002. This was consistent across sexes. Congenital anomalies (OR 3.54, 95% CI, 1.58-7.93, P = 0.002 and asthma (OR, 3.12, 95% CI, 1.43-6.80, P = 0.004 were most commonly associated with exposure. No single abnormality was associated with paternal exposure to mustard gas. Conclusion Our study demonstrates a generational effect of exposure to mustard gas. The lasting effects of mustard gas exposure in parents effects fertility and may impact child health and development in the long-term.

To describe and control exposure in nanoecotoxicology tests

DEFF Research Database (Denmark)

Baun, Anders

are fulfilling the purpose they originally were intended for (ranking and classification). The validity of extrapolations made from these data (e.g. predicted no-effect concentrations for environmental risk assessments) is therefore further questionable. Based on own experiences these fundamental problems......There is an urgent need for reliable and reproducible results of ecotoxicological experiments in order to identify, rank, and classify the environmental hazards of nanomaterials. Standardized methods and guideline tests traditionally used for chemicals are today recommended for the testing...... of nanomaterials. While the database of results from these tests is rapidly expanding, problems with controlling the exposure are often reported, e.g. due to the particle behavior in the test media used. Problems encountered include uncontrollable aggregation, agglomeration, sedimentation, or dissolution...

Design of a recirculating radon progeny aerosol generation and animal exposure system

International Nuclear Information System (INIS)

Newton, G.J.; Cuddihy, R.G.; Yeh, H.C.; Barr, E.B.; Boecker, B.B.

1988-01-01

Inhalation studies are being conducted at ITRI using laboratory animals exposed to radon-222 progeny attached to vector aerosols that are typical of indoor environments. The purpose of these studies is to identify the cells at risk from inhaled radon progeny and their locations within the respiratory tract. These studies require exposures up to 1000 working level months (WLM) within a few hours. Thus, large amounts of radium-226 are needed to produce the gaseous radon-222. A once-through-exposure-system was considered to be impractical because of statutory discharge limitations and the large amounts of radium that would be required. Therefore, a recirculating exposure system was designed and constructed that removes the aerosol after passing through the exposure chambers and recirculates purified air and radon. The purified radon is mixed with freshly evolving radon from a radon generator and passed Into a reaction-aging chamber where attachment of radon progeny to the vector aerosol occurs. The design includes: (1) 50-200 mg radium-226 in a radon generator, (2) 40 L/min total flow rate, (3) CO 2 removal, (4) reconstitution of oxygen tension and water vapor content to atmospheric levels, and (5) a trap for radon gas. A radon progeny exposure concentration in the range of 4,000 to 50,000 WL is being produced. (author)

Wisdom Appliance Control System

Science.gov (United States)

Hendrick; Jheng, Jyun-Teng; Tsai, Chen-Chai; Liou, Jia-Wei; Wang, Zhi-Hao; Jong, Gwo-Jia

2017-07-01

Intelligent appliances wisdom involves security, home care, convenient and energy saving, but the home automation system is still one of the core unit, and also using micro-processing electronics technology to centralized and control the home electrical products and systems, such as: lighting, television, fan, air conditioning, stereo, it composed of front-controller systems and back-controller panels, user using front-controller to control command, and then through the back-controller to powered the device.