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Sample records for icnirp reference level

  1. Children and adults exposed to electromagnetic fields at the ICNIRP reference levels: theoretical assessment of the induced peak temperature increase.

    PubMed

    Bakker, J F; Paulides, M M; Neufeld, E; Christ, A; Kuster, N; van Rhoon, G C

    2011-08-01

    To avoid potentially adverse health effects of electromagnetic fields (EMF), the International Commission on Non-Ionizing Radiation Protection (ICNIRP) has defined EMF reference levels. Restrictions on induced whole-body-averaged specific absorption rate (SAR(wb)) are provided to keep the whole-body temperature increase (T(body, incr)) under 1 °C during 30 min. Additional restrictions on the peak 10 g spatial-averaged SAR (SAR(10g)) are provided to prevent excessive localized tissue heating. The objective of this study is to assess the localized peak temperature increase (T(incr, max)) in children upon exposure at the reference levels. Finite-difference time-domain modeling was used to calculate T(incr, max) in six children and two adults exposed to orthogonal plane-wave configurations. We performed a sensitivity study and Monte Carlo analysis to assess the uncertainty of the results. Considering the uncertainties in the model parameters, we found that a peak temperature increase as high as 1 °C can occur for worst-case scenarios at the ICNIRP reference levels. Since the guidelines are deduced from temperature increase, we used T(incr, max) as being a better metric to prevent excessive localized tissue heating instead of localized peak SAR. However, we note that the exposure time should also be considered in future guidelines. Hence, we advise defining limits on T(incr, max) for specified durations of exposure. PMID:21772085

  2. Children and adults exposed to low-frequency magnetic fields at the ICNIRP reference levels: theoretical assessment of the induced electric fields

    NASA Astrophysics Data System (ADS)

    Bakker, J. F.; Paulides, M. M.; Neufeld, E.; Christ, A.; Chen, X. L.; Kuster, N.; van Rhoon, G. C.

    2012-04-01

    To avoid potentially adverse health effects, the International Commission on Non-Ionizing Radiation Protection (ICNIRP) has defined reference levels for time varying magnetic fields. Restrictions on the electric fields induced in the human body are provided based on biological response data for peripheral nerve stimulation and the induction of phosphenes. Numerical modeling is commonly used to assess the induced electric fields for various exposure configurations. The objective of this study was to assess the variations of the electric fields induced in children and adults and to compare the exposure at reference levels with the basic restrictions as function of anatomy. We used the scalar potential finite element method to calculate the induced electric fields in six children and two adults when exposed to uniform magnetic fields polarized in three orthogonal directions. We found that the induced electric fields are within the ICNIRP basic restrictions in nearly all cases. In PNS tissues, we found electric fields up to 95% (upper uncertainty limit due to discretization errors, k = 2) of the ICNIRP basic restrictions for exposures at the general public reference levels. For occupational reference levels, we found an over-exposure of maximum 79% (k = 2) in PNS tissues. We further found that the ICNIRP recommendations on spatial averaging in 2 × 2 × 2 mm3 contiguous tissue volumes and removal of peak values by the 99th percentile cause the results to depend strongly on the grid discretization step (i.e. an uncertainty of more than 50% at 2 mm) and the number of distinguished tissues in the anatomical models. The computational results obtained by various research institutes should be robust for different discretization settings and various anatomical models. Therefore, we recommend considering alternative routines for small anatomical structures such as non-contiguous averaging without taking the 99th percentile in future guidelines leading to consistent

  3. Children and adults exposed to low-frequency magnetic fields at the ICNIRP reference levels: theoretical assessment of the induced electric fields.

    PubMed

    Bakker, J F; Paulides, M M; Neufeld, E; Christ, A; Chen, X L; Kuster, N; van Rhoon, G C

    2012-04-01

    To avoid potentially adverse health effects, the International Commission on Non-Ionizing Radiation Protection (ICNIRP) has defined reference levels for time varying magnetic fields. Restrictions on the electric fields induced in the human body are provided based on biological response data for peripheral nerve stimulation and the induction of phosphenes. Numerical modeling is commonly used to assess the induced electric fields for various exposure configurations. The objective of this study was to assess the variations of the electric fields induced in children and adults and to compare the exposure at reference levels with the basic restrictions as function of anatomy. We used the scalar potential finite element method to calculate the induced electric fields in six children and two adults when exposed to uniform magnetic fields polarized in three orthogonal directions. We found that the induced electric fields are within the ICNIRP basic restrictions in nearly all cases. In PNS tissues, we found electric fields up to 95% (upper uncertainty limit due to discretization errors, k = 2) of the ICNIRP basic restrictions for exposures at the general public reference levels. For occupational reference levels, we found an over-exposure of maximum 79% (k = 2) in PNS tissues. We further found that the ICNIRP recommendations on spatial averaging in 2 × 2 × 2 mm³ contiguous tissue volumes and removal of peak values by the 99th percentile cause the results to depend strongly on the grid discretization step (i.e. an uncertainty of more than 50% at 2 mm) and the number of distinguished tissues in the anatomical models. The computational results obtained by various research institutes should be robust for different discretization settings and various anatomical models. Therefore, we recommend considering alternative routines for small anatomical structures such as non-contiguous averaging without taking the 99th percentile in future guidelines leading to consistent

  4. Pineal melatonin level disruption in humans due to electromagnetic fields and ICNIRP limits.

    PubMed

    Halgamuge, Malka N

    2013-05-01

    The International Agency for Research on Cancer (IARC) classifies electromagnetic fields (EMFs) as 'possibly carcinogenic' to humans that might transform normal cells into cancer cells. Owing to high utilisation of electricity in day-to-day life, exposure to power-frequency (50 or 60 Hz) EMFs is unavoidable. Melatonin is a natural hormone produced by pineal gland activity in the brain that regulates the body's sleep-wake cycle. How man-made EMFs may influence the pineal gland is still unsolved. The pineal gland is likely to sense EMFs as light but, as a consequence, may decrease the melatonin production. In this study, more than one hundred experimental data of human and animal studies of changes in melatonin levels due to power-frequency electric and magnetic fields exposure were analysed. Then, the results of this study were compared with the International Committee of Non-Ionizing Radiation Protection (ICNIRP) limit and also with the existing experimental results in the literature for the biological effect of magnetic fields, in order to quantify the effects. The results show that this comparison does not seem to be consistent despite the fact that it offers an advantage of drawing attention to the importance of the exposure limits to weak EMFs. In addition to those inconsistent results, the following were also observedfrom this work: (i) the ICNIRP recommendations are meant for the well-known acute effects, because effects of the exposure duration cannot be considered and (ii) the significance of not replicating the existing experimental studies is another limitation in the power-frequency EMFs. Regardless of these issues, the above observation agrees with our earlier study in which it was confirmed that it is not a reliable method to characterise biological effects by observing only the ratio of AC magnetic field strength to frequency. This is because exposure duration does not include the ICNIRP limit. Furthermore, the results show the significance of

  5. ENRAF gauge reference level calculations

    SciTech Connect

    Huber, J.H., Fluor Daniel Hanford

    1997-02-06

    This document describes the method for calculating reference levels for Enraf Series 854 Level Detectors as installed in the tank farms. The reference level calculation for each installed level gauge is contained herein.

  6. A quick and easy method for checking compliance of multi-frequency magnetic fields with ICNIRP's guidelines.

    PubMed

    Filippopoulos, George; Karabetsos, Efthymios

    2008-08-01

    In many practical cases human exposure to extremely low frequency magnetic fields with many spectral components (multi-frequency fields) has to be examined in order to check compliance with ICNIRP's guidelines. Showing compliance, according to existing methods, requires sophisticated instruments and measurement procedures to assess some complex exposure metrics. Furthermore, even where the field levels are very low, there is no method to show compliance using broadband instruments, which are the most common and simple ones. In this paper, a new method is described where the frequencies emitted by the source are known and only simple broadband instruments are required. First, the spectral distribution of the field that maximizes exposure metrics is found. Then, an effective reference level for the broadband value of the field is estimated for this distribution. If the measured broadband value of the magnetic field is lower than this reference level, then compliance with ICNIRP's guidelines is readily shown. A case study for a magnetic field consisting of 50 Hz and 60 Hz components is presented. The worst-case spectral distribution contained 64% 50 Hz and 76.8% 60 Hz components, and the corresponding effective broadband reference level is 64 muT for general public exposure. The method is generally conservative in cases of incoherent fields and very conservative in cases of coherent fields. To that end, it is practically a quick and easy test to check if further measurements are needed or not. Application of this method is expected to save time, money, and resources. PMID:18617807

  7. Basic Restriction and Reference Level in Anatomically-based Japanese Models for Low-Frequency Electric and Magnetic Field Exposures

    NASA Astrophysics Data System (ADS)

    Takano, Yukinori; Hirata, Akimasa; Fujiwara, Osamu

    Human exposed to electric and/or magnetic fields at low frequencies may cause direct effect such as nerve stimulation and excitation. Therefore, basic restriction is regulated in terms of induced current density in the ICNIRP guidelines and in-situ electric field in the IEEE standard. External electric or magnetic field which does not produce induced quantities exceeding the basic restriction is used as a reference level. The relationship between the basic restriction and reference level for low-frequency electric and magnetic fields has been investigated using European anatomic models, while limited for Japanese model, especially for electric field exposures. In addition, that relationship has not well been discussed. In the present study, we calculated the induced quantities in anatomic Japanese male and female models exposed to electric and magnetic fields at reference level. A quasi static finite-difference time-domain (FDTD) method was applied to analyze this problem. As a result, spatially averaged induced current density was found to be more sensitive to averaging algorithms than that of in-situ electric field. For electric and magnetic field exposure at the ICNIRP reference level, the maximum values of the induced current density for different averaging algorithm were smaller than the basic restriction for most cases. For exposures at the reference level in the IEEE standard, the maximum electric fields in the brain were larger than the basic restriction in the brain while smaller for the spinal cord and heart.

  8. Radio Hazard Safety Assessment for Marine Ship Transmitters: Measurements Using a New Data Collection Method and Comparison with ICNIRP and ARPANSA Limits.

    PubMed

    Halgamuge, Malka N

    2015-05-01

    We investigated the levels of radio frequency electromagnetic fields (RF EMFs) emitted from marine ship transmitters. In this study, we recorded the radio frequency (RF) electric field (EF) levels emitted from transmitters from a marine vessel focusing on the areas normally occupied by crew members and passengers. Previous studies considered radiation hazard safety assessment for marine vessels with a limited number of transmitters, such as very high-frequency (VHF) transceivers, radar and communication transmitters. In our investigation, EF levels from seven radio transmitters were measured, including: VHF, medium frequency/high frequency (MF/HF), satellite communication (Sat-Com C), AISnavigation, radar X-band and radar S-band. Measurements were carried out in a 40 m-long, three-level ship (upper deck, bridge deck and bridge roof) at 12 different locations. We developed a new data-collection protocol and performed it under 11 different scenarios to observe and measure the radiation emissions from all of the transmitters. In total, 528 EF field measurements were collected and averaged over all three levels of the marine ship with RF transmitters: the measured electric fields were the lowest on the upper deck (0.82-0.86 V/m), the highest on the bridge roof (2.15-3.70 V/m) and in between on the bridge deck (0.47-1.15 V/m). The measured EF levels were then assessed for compliance with the occupational and general public reference levels of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines and the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) standards. The ICNIRP and the ARPANSA limits for the general public were exceeded on the bridge roof; nevertheless, the occupational limits were respected everywhere. The measured EF levels, hence, complied with the ICNIRP guidelines and the ARPANSA standards. In this paper, we provide a new data collection model for future surveys, which could be conducted with larger

  9. Radio Hazard Safety Assessment for Marine Ship Transmitters: Measurements Using a New Data Collection Method and Comparison with ICNIRP and ARPANSA Limits

    PubMed Central

    Halgamuge, Malka N.

    2015-01-01

    We investigated the levels of radio frequency electromagnetic fields (RF EMFs) emitted from marine ship transmitters. In this study, we recorded the radio frequency (RF) electric field (EF) levels emitted from transmitters from a marine vessel focusing on the areas normally occupied by crew members and passengers. Previous studies considered radiation hazard safety assessment for marine vessels with a limited number of transmitters, such as very high-frequency (VHF) transceivers, radar and communication transmitters. In our investigation, EF levels from seven radio transmitters were measured, including: VHF, medium frequency/high frequency (MF/HF), satellite communication (Sat-Com C), AISnavigation, radar X-band and radar S-band. Measurements were carried out in a 40 m-long, three-level ship (upper deck, bridge deck and bridge roof) at 12 different locations. We developed a new data-collection protocol and performed it under 11 different scenarios to observe and measure the radiation emissions from all of the transmitters. In total, 528 EF field measurements were collected and averaged over all three levels of the marine ship with RF transmitters: the measured electric fields were the lowest on the upper deck (0.82–0.86 V/m), the highest on the bridge roof (2.15–3.70 V/m) and in between on the bridge deck (0.47–1.15 V/m). The measured EF levels were then assessed for compliance with the occupational and general public reference levels of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines and the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) standards. The ICNIRP and the ARPANSA limits for the general public were exceeded on the bridge roof; nevertheless, the occupational limits were respected everywhere. The measured EF levels, hence, complied with the ICNIRP guidelines and the ARPANSA standards. In this paper, we provide a new data collection model for future surveys, which could be conducted with

  10. Influence of the surface averaging procedure of the current density in assessing compliance with the ICNIRP low-frequency basic restrictions by means of numerical techniques

    NASA Astrophysics Data System (ADS)

    Zoppetti, N.; Andreuccetti, D.

    2009-08-01

    Although the calculation of the surface average of the low-frequency current density distribution over a cross-section of 1 cm2 is required by ICNIRP guidelines, no reference averaging algorithm is indicated, neither in the ICNIRP guidelines nor in the Directive 2004/40/EC that is based on them. The lack of a general standard algorithm that fulfils the ICNIRP guidelines' requirements is particularly critical in the prospective of the 2004/40/EC Directive endorsement, since the compliance to normative limits refers to well-defined procedures. In this paper, two case studies are considered, in which the calculation of the surface average is performed using a simplified approach widely used in the literature and an original averaging procedure. This analysis, aimed at quantifying the expected differences and to single out their sources, shows that the choice of the averaging algorithm represents an important source of uncertainty in the application of the guideline requirements.

  11. [Diagnostic reference levels in interventional radiology].

    PubMed

    Vañó Carruana, E; Fernández Soto, J M; Sánchez Casanueva, R M; Ten Morón, J I

    2013-12-01

    This article discusses the diagnostic reference levels for radiation exposure proposed by the International Commission on Radiological Protection (ICRP) to facilitate the application of the optimization criteria in diagnostic imaging and interventional procedures. These levels are normally established as the third quartile of the dose distributions to patients in an ample sample of centers and are supposed to be representative of good practice regarding patient exposure. In determining these levels, it is important to evaluate image quality as well to ensure that it is sufficient for diagnostic purposes. When the values for the dose received by patients are systematically higher or much lower than the reference levels, an investigation should determine whether corrective measures need to be applied. The European and Spanish regulations require the use of these reference values in quality assurance programs. For interventional procedures, the dose area product (or kerma area product) values are usually used as reference values together with the time under fluoroscopy and the total number of images acquired. The most modern imaging devices allow the value of the accumulated dose at the entrance to the patient to be calculated to optimize the distribution of the dose on the skin. The ICRP recommends that the complexity of interventional procedures be taken into account when establishing reference levels. In the future, diagnostic imaging departments will have automatic systems to manage patient dosimetric data; these systems will enable continuous dosage auditing and alerts about individual procedures that might involve doses several times above the reference values. This article also discusses aspects that need to be clarified to take better advantage of the reference levels in interventional procedures. PMID:24211195

  12. The role of skin conductivity in a low frequency exposure assessment for peripheral nerve tissue according to the ICNIRP 2010 guidelines

    NASA Astrophysics Data System (ADS)

    Schmid, Gernot; Cecil, Stefan; Überbacher, Richard

    2013-07-01

    Based on numerical computations using commercially available finite difference time domain code and a state-of-the art anatomical model of a 5-year old child, the influence of skin conductivity on the induced electric field strength inside the tissue for homogeneous front-to-back magnetic field exposure and homogeneous vertical electric field exposure was computed. Both ungrounded as well as grounded conditions of the body model were considered. For electric field strengths induced inside CNS tissue the impact of skin conductivity was found to be less than 15%. However, the results demonstrated that the use of skin conductivity values as obtainable from the most widely used data base of dielectric tissue properties and recommended by safety standards are not suitable for exposure assessment with respect to peripheral nerve tissue according to the ICNIRP 2010 guidelines in which the use of the induced electric field strengths inside the skin is suggested as a conservative surrogate for peripheral nerve exposure. This is due to the fact that the skin conductivity values derived from these data bases refer to the stratum corneum, the uppermost layer of the skin, which does not contain any nerve or receptor cells to be protected from stimulation effects. Using these skin conductivity values which are approximately a factor 250-500 lower than skin conductivity values used in studies on which the ICNIRP 2010 guidelines are based on, may lead to overestimations of the induced electric field strengths inside the skin by substantially more than a factor of 10. However, reliable conductivity data of deeper skin layers where nerve and preceptor cells are located is very limited. It is therefore recommended to include appropriate background information in the ICNIRP guidelines and the dielectric tissue property databases, and to put some emphasis on a detailed layer-specific characterization of skin conductivity in near future.

  13. The role of skin conductivity in a low frequency exposure assessment for peripheral nerve tissue according to the ICNIRP 2010 guidelines.

    PubMed

    Schmid, Gernot; Cecil, Stefan; Überbacher, Richard

    2013-07-01

    Based on numerical computations using commercially available finite difference time domain code and a state-of-the art anatomical model of a 5-year old child, the influence of skin conductivity on the induced electric field strength inside the tissue for homogeneous front-to-back magnetic field exposure and homogeneous vertical electric field exposure was computed. Both ungrounded as well as grounded conditions of the body model were considered. For electric field strengths induced inside CNS tissue the impact of skin conductivity was found to be less than 15%. However, the results demonstrated that the use of skin conductivity values as obtainable from the most widely used data base of dielectric tissue properties and recommended by safety standards are not suitable for exposure assessment with respect to peripheral nerve tissue according to the ICNIRP 2010 guidelines in which the use of the induced electric field strengths inside the skin is suggested as a conservative surrogate for peripheral nerve exposure. This is due to the fact that the skin conductivity values derived from these data bases refer to the stratum corneum, the uppermost layer of the skin, which does not contain any nerve or receptor cells to be protected from stimulation effects. Using these skin conductivity values which are approximately a factor 250-500 lower than skin conductivity values used in studies on which the ICNIRP 2010 guidelines are based on, may lead to overestimations of the induced electric field strengths inside the skin by substantially more than a factor of 10. However, reliable conductivity data of deeper skin layers where nerve and preceptor cells are located is very limited. It is therefore recommended to include appropriate background information in the ICNIRP guidelines and the dielectric tissue property databases, and to put some emphasis on a detailed layer-specific characterization of skin conductivity in near future. PMID:23774744

  14. On the issues related to compliance assessment of ICNIRP 2010 basic restrictions.

    PubMed

    De Santis, Valerio; Chen, Xi Lin

    2014-06-01

    This article discusses technical issues related to compliance assessment of ICNIRP 2010 basic restrictions. Several difficulties are identified in this study when assessing the spatial average and 99th percentile value of the electric field. These issues are mainly attributed to the lack of clarity in the guideline specifications, which leads to inadequate or irreproducible results. Effects on compliance results due to such ambiguous procedures are hereby investigated, with particular focus on technical issues rather than biological ones. Examples spanning from simple canonical test cases to realistic applications have been selected to highlight the strong variability in dosimetry results. Based on our findings, revisiting the ICNIRP 2010 guidelines is strongly recommended, and proposed alternative solutions are outlined. PMID:24705441

  15. Establishment of diagnostic reference levels for dental intraoral radiography.

    PubMed

    Manousaridis, G; Koukorava, C; Hourdakis, C J; Kamenopoulou, V; Yakoumakis, E; Tsiklakis, K

    2013-10-01

    Diagnostic reference levels (DRLs) is a tool for the optimisation of radiological procedures. Establishment of a DRL is a requirement of national regulations. Measurements performed by the Greek Atomic Energy Commission on 529 dental intraoral radiographic facilities have been used in order to define DRLs for digital and film imaging modalities, taking into account the region of the mouth to be imaged. Thus, different DRL values have been proposed for minimum (usually incisors), maximum (usually maxillary molars) and average exposure settings, both for film and digital imaging. The results have been compared with similar studies performed in Europe and the USA and are in line with the most recent ones. PMID:23615358

  16. Establishment of dose reference levels for nuclear medicine in Greece.

    PubMed

    Vogiatzi, S; Kipouros, P; Chobis, M

    2011-09-01

    Greek Atomic Energy Commission's Department of Licensing and Inspections conducted a national survey for the establishment of nuclear medicine (NM) dose reference levels (DRLs) for adult patients, in Greece. The administered activities (AAs) (MBq) were collected from 120 NM departments (88 % of total), during on-site inspections for licensing purposes. Factors influencing the image quality were also investigated. The established national DRLs represent the AA value corresponding to the 75th percentile of the AA frequency distributions. In their majority, national DRLs and average AAs are comparable with the ones published in the international literature. In the light of new technologies, there might be potential for reducing the higher values of AAs, in co-operation with the nuclear medicine experts. PMID:21765158

  17. Validation of ICNIRP estimates of toxicity thresholds for NIR (785 nm) light in the retinas of pigmented rabbits.

    PubMed

    Borchert, Mark; Lambert, James; Sliney, David

    2006-01-01

    The International Commission on Non-Ionizing Radiation Protection (ICNIRP) established eye-safe exposure limits for laser light based on estimates of the 50% exposure dose (ED50) for retinal damage in animals. The ED50 has not been determined for continuous-wave near-infrared (NIR) light, as may be used in instruments for spectroscopic analysis of the eye. The purpose of this study is to determine the ED50 of 785-nm light delivered by a Raman spectroscopy instrument on the retinas of pigmented rabbits, and to compare that ED50 to the ICNIRP estimates. Light of varying power was focused into the anterior chambers of rabbits for 4, 20, or 300 s. Estimates of spot size on the retina were determined by modifying the schematic rabbit eye with actual axial length and refractive error measurements. Masked examiners determined retinal burns from fundus photographs and fluorescein angiograms made immediately after exposure and again 48-72 h later. Thirty-five of 86 exposed eyes had retinal burns. In 12 of these the burn was not visible until 48-72 h. In 6 the burn was visible on color photographs, but not on fluorescein angiography. The ED50 retinal power density from probit analysis was 14,513 mW cm(-2), 10,369 mW cm(-2), and 5,237 mW cm(-2) for 4-s, 20-s, and 300-s exposures, respectively. Thus, the ED50 for retinal burns from 785-nm light is approximately 7 and 7.5 times the ICNIRP permitted limits for 4- and 20-s exposures, and 5.6 times the limit for 300-s exposures. This is consistent with the ICNIRP intention to set power limits several times less than ED50. PMID:16340602

  18. Patient Dose Reference Levels for Interventional Radiology: A National Approach

    SciTech Connect

    Vano, Eliseo Sanchez, R.; Fernandez, J. M.; Gallego, J. J.; Verdu, J. F.; Garay, M. Gonzalez de; Azpiazu, A.; Segarra, A.; Hernandez, M. T.; Canis, M.; Diaz, F.; Moreno, F.; Palmero, J.

    2009-01-15

    A set of patient dose reference levels (RLs) for fluoroscopically guided interventional procedures was obtained in a survey launched by the National Society of Interventional Radiology (IR), involving 10 public hospitals, as recommended by the European Medical Exposures Directive. A sample of 1391 dose values (kerma area product [KAP]) was collected randomly during clinical procedures for seven of the most frequent procedures. Third quartiles of the KAP distributions were used to set the RLs. A regular quality control of the X-ray systems and a calibration of the dose meters were performed during the survey. The fluoroscopy time and total number of digital subtraction angiography images per procedure were also analyzed. The RL values proposed were 12 Gy cm{sup 2} for fistulography (hemodialysis access; sample of 180 cases), 73 Gy cm{sup 2} for lower limb arteriography (685 cases), 89 Gy cm{sup 2} for renal arteriography (55 cases), 80 Gy cm{sup 2} for biliary drainage (205 cases), 289 Gy cm{sup 2} for hepatic chemoembolization (151 cases), 94 Gy cm{sup 2} for iliac stent (70 cases), and 236 Gy cm{sup 2} for uterine embolization (45 cases). The provisional national RL values are lower than those obtained in a similar survey carried out in the United States from 2002 to 2004. These new values could be used to improve the practice of centers consistently working with doses higher than the RLs. This national survey also had a positive impact, as it helped increase the awareness of the members of the National Society of IR on a topic as crucial as patient dose values and programs on radiation protection.

  19. Radiometer calibration procedure and beacon attenuation estimation reference level

    NASA Technical Reports Server (NTRS)

    Crane, Robert K.

    1994-01-01

    The primary objectives are to compare radiometer attenuation with beacon attenuation and to compare sky temperature estimates with calculations using simultaneous meteorological data. Secondary objectives are: (1) noise diode and reference load measurements and (2) to adjust for outside temperature and component temperature changes.

  20. Reference commercial high-level waste glass and canister definition.

    SciTech Connect

    Slate, S.C.; Ross, W.A.; Partain, W.L.

    1981-09-01

    This report presents technical data and performance characteristics of a high-level waste glass and canister intended for use in the design of a complete waste encapsulation package suitable for disposal in a geologic repository. The borosilicate glass contained in the stainless steel canister represents the probable type of high-level waste product that will be produced in a commercial nuclear-fuel reprocessing plant. Development history is summarized for high-level liquid waste compositions, waste glass composition and characteristics, and canister design. The decay histories of the fission products and actinides (plus daughters) calculated by the ORIGEN-II code are presented.

  1. Diagnostic reference levels for medical exposure of patients: ICRP guidance and related ICRU quantities.

    PubMed

    Rosenstein, Marvin

    2008-11-01

    In Publication 60 of the International Commission on Radiological Protection reference levels were described as values of measured quantities at which some specified action or decision should be taken. One particular form of reference level, the diagnostic reference level, applies specifically to medical exposure of patients. The objective of a diagnostic reference level is to help avoid radiation dose to the patient that does not contribute to the clinical purpose of a medical imaging task. This is accomplished by comparison between the numerical value of the diagnostic reference level and the mean or other appropriate value observed in practice for a suitable reference group of patients or a suitable reference phantom. A diagnostic reference level is not applied to individual patients. Diagnostic reference levels have no direct linkage to the numerical values for dose limits or dose constraints, and it is inappropriate to use them for regulatory or commercial purposes. Diagnostic reference levels should be selected by professional medical bodies (often in conjunction with health and radiation protection authorities) and their values may be specific to a country or region. A diagnostic reference level can be used: (1) to improve a regional, national or local distribution of observed results for a general medical imaging task, by reducing the frequency of unjustified high or low values; (2) to promote attainment of a narrower range of values that represent good practice for a more specific medical imaging task; or (3) to promote attainment of an optimum range of values for a specified medical imaging protocol. Authorized bodies are encouraged to set diagnostic reference levels that best meet their specific needs and that are consistent for the regional, national or local area to which they apply. Report 74 of the International Commission on Radiation Units and Measurements includes a commentary regarding quantities useful in establishing diagnostic reference levels

  2. Forget the Desk Job: Current Roles and Responsibilities in Entry-Level Reference Job Advertisements

    ERIC Educational Resources Information Center

    Detmering, Robert; Sproles, Claudene

    2012-01-01

    This study examines the evolving roles and responsibilities of entry-level academic reference positions, as stated in recent job advertisements posted on the American Library Association's JobLIST Web site and other sources. Findings from a content analysis of these advertisements indicate that current entry-level reference positions in academic…

  3. Hearing Tests on Mobile Devices: Evaluation of the Reference Sound Level by Means of Biological Calibration

    PubMed Central

    Kipiński, Lech; Grysiński, Tomasz; Kręcicki, Tomasz

    2016-01-01

    Background Hearing tests carried out in home setting by means of mobile devices require previous calibration of the reference sound level. Mobile devices with bundled headphones create a possibility of applying the predefined level for a particular model as an alternative to calibrating each device separately. Objective The objective of this study was to determine the reference sound level for sets composed of a mobile device and bundled headphones. Methods Reference sound levels for Android-based mobile devices were determined using an open access mobile phone app by means of biological calibration, that is, in relation to the normal-hearing threshold. The examinations were conducted in 2 groups: an uncontrolled and a controlled one. In the uncontrolled group, the fully automated self-measurements were carried out in home conditions by 18- to 35-year-old subjects, without prior hearing problems, recruited online. Calibration was conducted as a preliminary step in preparation for further examination. In the controlled group, audiologist-assisted examinations were performed in a sound booth, on normal-hearing subjects verified through pure-tone audiometry, recruited offline from among the workers and patients of the clinic. In both the groups, the reference sound levels were determined on a subject’s mobile device using the Bekesy audiometry. The reference sound levels were compared between the groups. Intramodel and intermodel analyses were carried out as well. Results In the uncontrolled group, 8988 calibrations were conducted on 8620 different devices representing 2040 models. In the controlled group, 158 calibrations (test and retest) were conducted on 79 devices representing 50 models. Result analysis was performed for 10 most frequently used models in both the groups. The difference in reference sound levels between uncontrolled and controlled groups was 1.50 dB (SD 4.42). The mean SD of the reference sound level determined for devices within the same model

  4. Levelized Cost of Energy Analysis of Marine and Hydrokinetic Reference Models: Preprint

    SciTech Connect

    Jenne, D. S.; Yu, Y. H.; Neary, V.

    2015-04-24

    In 2010 the U.S. Department of Energy initiated the development of six marine energy converter reference models. The reference models are point designs of well-known marine energy converters. Each device was designed to operate in a specific marine resource, instead of a generic device that can be deployed at any location. This method allows each device to be used as a benchmark for future reference model to benchmark future devices. The six designs consist of three current energy converters and three wave energy converters. The reference model project has generated both technical and economic data sets that are available in the public domain. The methodology to calculate the levelized cost of energy for the reference model project and an overall comparison of the cost of energy from these six reference-model designs are presented in this paper.

  5. Defining reference levels for intra-operative radiation exposure in orthopaedic trauma: A retrospective multicentre study.

    PubMed

    Hardman, J; Elvey, M; Shah, N; Simson, N; Patel, S; Anakwe, R

    2015-12-01

    There is currently limited data to define reference levels for the use of ionising radiation in orthopaedic trauma surgery. In this multicentre study, we utilise methodology employed by the Health Protection Agency in establishing reference levels for diagnostic investigations in order to define analogous levels for common and reproducible orthopaedic trauma procedures. Four hundred ninety-five procedures were identified across four Greater London hospitals over a 1-year period. Exposure was defined in terms of both time and dose area product (DAP). Third quartile mean values for either parameter were used to define reference levels. Variations both between centres and grades of lead surgeon were analysed as secondary outcomes. Reference levels; dynamic hip screw (DHS) 1.9225000 Gycm(2)/70.50 s, intramedullary (IM) femoral nail 1.5837500 Gycm(2)/126.00 s, open reduction internal fixation (ORIF) clavicle 0.2042500 Gycm(2)/21.50 s, ORIF lateral malleolus 0.32250500 Gycm(2)/35.00 s, ORIF distal radius 0.1300000 Gycm(2)/56.00 s. Grade of surgeon did not influence exposure in dynamic hip screw, and was inversely related to exposure in intramedullary femoral nails. Less variation was observed with exposure time than with DAP. This study provides the most comprehensive reference to guide fluoroscopy use in orthopaedic trauma to date, and is of value both at the point of delivery and for audit of local practice. PMID:26604035

  6. Defining Top-of-Atmosphere Flux Reference Level for Earth Radiation Budget Studies

    NASA Technical Reports Server (NTRS)

    Loeb, N. G.; Kato, S.; Wielicki, B. A.

    2002-01-01

    To estimate the earth's radiation budget at the top of the atmosphere (TOA) from satellite-measured radiances, it is necessary to account for the finite geometry of the earth and recognize that the earth is a solid body surrounded by a translucent atmosphere of finite thickness that attenuates solar radiation differently at different heights. As a result, in order to account for all of the reflected solar and emitted thermal radiation from the planet by direct integration of satellite-measured radiances, the measurement viewing geometry must be defined at a reference level well above the earth s surface (e.g., 100 km). This ensures that all radiation contributions, including radiation escaping the planet along slant paths above the earth s tangent point, are accounted for. By using a field-of- view (FOV) reference level that is too low (such as the surface reference level), TOA fluxes for most scene types are systematically underestimated by 1-2 W/sq m. In addition, since TOA flux represents a flow of radiant energy per unit area, and varies with distance from the earth according to the inverse-square law, a reference level is also needed to define satellite-based TOA fluxes. From theoretical radiative transfer calculations using a model that accounts for spherical geometry, the optimal reference level for defining TOA fluxes in radiation budget studies for the earth is estimated to be approximately 20 km. At this reference level, there is no need to explicitly account for horizontal transmission of solar radiation through the atmosphere in the earth radiation budget calculation. In this context, therefore, the 20-km reference level corresponds to the effective radiative top of atmosphere for the planet. Although the optimal flux reference level depends slightly on scene type due to differences in effective transmission of solar radiation with cloud height, the difference in flux caused by neglecting the scene-type dependence is less than 0.1%. If an inappropriate

  7. Reference gene selection for cross-species and cross-ploidy level comparisons in Chrysanthemum spp.

    PubMed Central

    Wang, Haibin; Chen, Sumei; Jiang, Jiafu; Zhang, Fei; Chen, Fadi

    2015-01-01

    The establishment of a (set of) stably expressed reference gene(s) is required to normalize transcription data. Polyploidy is very common in the plant kingdom, but it is not necessarily the case that a reference gene which works well at the diploid level will also work well at the polyploid level. Here, ten candidate reference genes are compared in the context of gene transcription in the genus Chrysanthemum. The robustness of some, but not all, of these was shown to be high across ploidy levels. MTP (metalloprotease) and ACTIN (actin) were the most stable in diploid and tetraploid C. nankingense, while PSAA (photosynthesis-related plastid gene representing photosystem I) and EF-1α (elongation factor-1α) were the most stable in tetraploid and hexaploid C. zawadskii. EF-1α and PGK (phosphoglycerate kinase) was the best combination for the complete set of four taxa. These results suggest that when making cross-species comparison of transcript abundance involving different ploidy levels, care needs to be taken in the selection of reference gene(s). PMID:25627791

  8. Nature of Environmental Education in Bangladesh: A School Level Assessment with Reference to the National Curriculum

    ERIC Educational Resources Information Center

    Chowdhury, M. A. Taiyeb

    2014-01-01

    This paper attempts to identify the nature of formal environmental education in Bangladesh at school level with particular reference to the national curriculum. The main objective of the study is to assess the contents of the school textbooks for each standard, and to see whether the diversified themes covered are a good representation of…

  9. Measurement of the weighted peak level for occupational exposure to gradient magnetic fields for 1.5 and 3 Tesla MRI body scanners.

    PubMed

    Bonutti, F; Tecchio, M; Maieron, M; Trevisan, D; Negro, C; Calligaris, F

    2016-03-01

    The purpose of this work is to give a contribution to the construction of a comprehensive knowledge of the exposure levels to gradient magnetic fields (GMF) in terms of the weighed peak (WP), especially for 3 Tesla scanners for which there are still few works available in the literature. A new generation probe for the measurement of electromagnetic fields in the range of 1 Hz-400 kHz was used to assess the occupational exposure levels to the GMF for 1.5 and 3.0 Tesla MRI body scanners, using the method of the WP according to the International Commission on Non-Ionizing Radiation Protection (ICNIRP) approach. The probe was placed at a height of 1.1 m, close to the MRI scanners, where operators could stay during some medical procedures with particular issues. The measurements were performed for a set of typical acquisition sequences for body (liver) and head exams. The measured values of WP were in compliance with ICNIRP 2010 reference levels for occupational exposures. PMID:25987585

  10. Determination of safety distance limits for a human near a cellular base station antenna, adopting the IEEE standard or ICNIRP guidelines.

    PubMed

    Cooper, Justin; Marx, Bernd; Buhl, Johannes; Hombach, Volker

    2002-09-01

    This paper investigates the minimum distance for a human body in the near field of a cellular telephone base station antenna for which there is compliance with the IEEE or ICNIRP threshold values for radio frequency electromagnetic energy absorption in the human body. First, local maximum specific absorption rates (SARs), measured and averaged over volumes equivalent to 1 and to 10 g tissue within the trunk region of a physical, liquid filled shell phantom facing and irradiated by a typical GSM 900 base station antenna, were compared to corresponding calculated SAR values. The calculation used a homogeneous Visible Human body model in front of a simulated base station antenna of the same type. Both real and simulated base station antennas operated at 935 MHz. Antenna-body distances were between 1 and 65 cm. The agreement between measurements and calculations was excellent. This gave confidence in the subsequent calculated SAR values for the heterogeneous Visible Human model, for which each tissue was assigned the currently accepted values for permittivity and conductivity at 935 MHz. Calculated SAR values within the trunk of the body were found to be about double those for the homogeneous case. When the IEEE standard and the ICNIRP guidelines are both to be complied with, the local SAR averaged over 1 g tissue was found to be the determining parameter. Emitted power values from the antenna that produced the maximum SAR value over 1 g specified in the IEEE standard at the base station are less than those needed to reach the ICNIRP threshold specified for the local SAR averaged over 10 g. For the GSM base station antenna investigated here operating at 935 MHz with 40 W emitted power, the model indicates that the human body should not be closer to the antenna than 18 cm for controlled environment exposure, or about 95 cm for uncontrolled environment exposure. These safe distance limits are for SARs averaged over 1 g tissue. The corresponding safety distance limits

  11. The Influence of the Terrestrial Reference Frame on Studies of Sea Level Change

    NASA Astrophysics Data System (ADS)

    Nerem, R. S.; Bar-Sever, Y. E.; Haines, B. J.; Desai, S.; Heflin, M. B.

    2015-12-01

    The terrestrial reference frame (TRF) provides the foundation for the accurate monitoring of sea level using both ground-based (tide gauges) and space-based (satellite altimetry) techniques. For the latter, tide gauges are also used to monitor drifts in the satellite instruments over time. The accuracy of the terrestrial reference frame (TRF) is thus a critical component for both types of sea level measurements. The TRF is central to the formation of geocentric sea-surface height (SSH) measurements from satellite altimeter data. The computed satellite orbits are linked to a particular TRF via the assumed locations of the ground-based tracking systems. The manner in which TRF errors are expressed in the orbit solution (and thus SSH) is not straightforward, and depends on the models of the forces underlying the satellite's motion. We discuss this relationship, and provide examples of the systematic TRF-induced errors in the altimeter derived sea-level record. The TRF is also crucial to the interpretation of tide-gauge measurements, as it enables the separation of vertical land motion from volumetric changes in the water level. TRF errors affect tide gauge measurements through GNSS estimates of the vertical land motion at each tide gauge. This talk will discuss the current accuracy of the TRF and how errors in the TRF impact both satellite altimeter and tide gauge sea level measurements. We will also discuss simulations of how the proposed Geodetic Reference Antenna in SPace (GRASP) satellite mission could reduce these errors and revolutionize how reference frames are computed in general.

  12. Reference levels in the context of Fukushima and related lessons learned.

    PubMed

    Sakai, Kazuo

    2013-11-01

    About 1 mo after the Fukushima Dai-ichi nuclear power plant accident, which was caused by the Great East Japan earthquake and tsunami on 11 March 2011, Japanese authorities set a dose criterion for the use of school playgrounds in Fukushima at 20 mSv y⁻¹ based on the International Commission on Radiological Protection recommendation for the reference level for the public under the existing exposure situation. This dose criterion was intended as a start line for reducing the dose to children; however, it caused much confusion among the public due to the misunderstanding of the concept of optimization and the application of reference level. Also, concerns were caused by the lack of precise but understandable information on radiation effects. This situation highlighted the importance of an understanding of radiation protection concepts by members of the general public and the outreach activities of radiation protection experts, both of which are essential for Fukushima recovery. PMID:24077049

  13. Reference Data for the Ruff Figural Fluency Test Stratified by Age and Educational Level

    PubMed Central

    Izaks, Gerbrand J.; Joosten, Hanneke; Koerts, Janneke; Gansevoort, Ron T.; Slaets, Joris P.

    2011-01-01

    The Ruff Figural Fluency Test (RFFT) was developed to avoid the difficulties that were encountered in earlier tests of figural fluency. Although the test characteristics of the RFFT seem to be good and it is a valuable addition to neuropsychological assessments, reference data are still scarce. To this aim, we required 2,404 community dwelling persons in Groningen, the Netherlands to perform the RFFT. All 1,651 persons with a complete RFFT and known educational level formed the reference sample. Their age ranged from 35 to 82 years and their educational level from primary school to university grade. Ninety-six percent of the persons were of Western European descent. All tests were analyzed by two independent examiners and subsequently three measures were calculated: number of unique designs, number of perseverative errors and error ratio. The main finding was that performance on the RFFT was dependent on age and educational level. This was not only observed in older persons but also in young and middle-aged persons. Reference data for the three RFFT measures are presented in groups of five years of age ranging from 35–39 years to 75 years or older. PMID:21347325

  14. Reference design and operations for deep borehole disposal of high-level radioactive waste.

    SciTech Connect

    Herrick, Courtney Grant; Brady, Patrick Vane; Pye, Steven; Arnold, Bill Walter; Finger, John Travis; Bauer, Stephen J.

    2011-10-01

    A reference design and operational procedures for the disposal of high-level radioactive waste in deep boreholes have been developed and documented. The design and operations are feasible with currently available technology and meet existing safety and anticipated regulatory requirements. Objectives of the reference design include providing a baseline for more detailed technical analyses of system performance and serving as a basis for comparing design alternatives. Numerous factors suggest that deep borehole disposal of high-level radioactive waste is inherently safe. Several lines of evidence indicate that groundwater at depths of several kilometers in continental crystalline basement rocks has long residence times and low velocity. High salinity fluids have limited potential for vertical flow because of density stratification and prevent colloidal transport of radionuclides. Geochemically reducing conditions in the deep subsurface limit the solubility and enhance the retardation of key radionuclides. A non-technical advantage that the deep borehole concept may offer over a repository concept is that of facilitating incremental construction and loading at multiple perhaps regional locations. The disposal borehole would be drilled to a depth of 5,000 m using a telescoping design and would be logged and tested prior to waste emplacement. Waste canisters would be constructed of carbon steel, sealed by welds, and connected into canister strings with high-strength connections. Waste canister strings of about 200 m length would be emplaced in the lower 2,000 m of the fully cased borehole and be separated by bridge and cement plugs. Sealing of the upper part of the borehole would be done with a series of compacted bentonite seals, cement plugs, cement seals, cement plus crushed rock backfill, and bridge plugs. Elements of the reference design meet technical requirements defined in the study. Testing and operational safety assurance requirements are also defined. Overall

  15. Arterial blood gas reference values for sea level and an altitude of 1,400 meters.

    PubMed

    Crapo, R O; Jensen, R L; Hegewald, M; Tashkin, D P

    1999-11-01

    Blood gas measurements were collected on healthy lifetime nonsmokers at sea level (n = 96) and at an altitude of 1,400 meters (n = 243) to establish reference equations. At each study site, arterial blood samples were analyzed in duplicate on two separate blood gas analyzers and CO-oximeters. Arterial blood gas variables included Pa(O(2)), Pa(CO(2)), pH, and calculated alveolar-arterial PO(2) difference (AaPO(2)). CO-oximeter variables were Hb, COHb, MetHb, and Sa(O(2)). Subjects were 18 to 81 yr of age with 166 male and 173 female. Outlier data were excluded from multiple regression analysis, and reference equations were fitted to the data in two ways: (1) best fit using linear, squared, and cross-product terms; (2) simple equations, including only the variables that explained at least 3% of the variance. Two sets of equations were created: (1) using only the sea level data and (2) using the combined data with barometric pressure as an independent variable. Comparisons with earlier studies revealed small but significant differences; the decline in Pa(O(2)) with age at each altitude was consistent with most previous studies. At sea level, the equation that included barometric pressure predicted Pa(O(2)) slightly better than the sea level specific equation. The inclusion of barometric pressure in the equations allows better prediction of blood gas reference values at sea level and at altitudes as high as 1,400 meters. PMID:10556115

  16. Re-evaluation of the reference dose for methylmercury and assessment of current exposure levels

    SciTech Connect

    Stern, A.H. )

    1993-06-01

    Methylmercury (Me-Hg) is widely distributed through freshwater and saltwater food chains and human consumption of fish and shellfish has lead to widespread exposure. Both the US EPA Reference Dose (0.3 [mu]g/kg/day) and the FAO/WHO Permissible Tolerable Weekly Intake (3.3 [mu]g/kg/week) are currently based on the prevention of paraesthesia in adult and older children. However, Me-Hg exposure in utero is known to result in a range of developmental neurologic effects including clinical CNS symptoms and delayed onset of walking. Based on a critical review of development toxicity data from human and animal studies, it is concluded that current guidelines for the prevention of paraesthesia are not adequate to address developmental effects. A dose of 0.07 [mu]g/kg/day is suggested as the best estimate of a potential reference dose for developmental effects. Data on nationwide fish consumption rates and Me-Hg levels in fish/seafood weighted by proportion of the catch intended for human consumption are analyzed in a Monte Carlo simulation to derive a probability distribution of background Me-Hg exposure. While various uncertainties in the toxicologic and exposure data limit the precision with which health risk can be estimated, this analysis suggests that at current levels of Me-Hg exposure, a significant fraction of women of childbearing age have exposures above this suggested reference dose.

  17. Benchmark dose estimation of cadmium reference level for hypertension in a Chinese population.

    PubMed

    Chen, Xiao; Wang, Zhongqiu; Zhu, Guoying; Liang, Yihuai; Jin, Taiyi

    2015-01-01

    Cadmium exposure can cause high blood pressure or hypertension. Benchmark dose has been used to estimate the reference point of cadmium for kidney and bone damage. In this study, we observed the association of blood pressure and cadmium in blood (BCd) and evaluated the reference level of cadmium for hypertension using benchmark dose (BMD) approach. A total of 441 subjects were included in this study. Blood samples were collected from each individual for BCd determination. Blood pressure was measured by electronic sphygmomanometer. BMD and BMDL were calculated using BMD software corresponding to additional risk of 10%. The systolic blood pressure (SBP), diastolic blood pressure (DBP) and prevalence of hypertension increased with the increasing of BCd, especially for SBP (χ(2)=3.9, p=0.047 in men; χ(2)=4.3, p=0.037 in women). With a benchmark response of 10%, the BMDL10 for hypertension (high SBP) was 0.95μg/L and 1.02μg/L for women and men, respectively; the BMDL10 for hypertension (high DBP) was 1.8μg/L and 1.66μg/L for women and men, respectively. Our data evidenced that BCd was associated with elevation in blood pressure and hypertension, especially for women. The reference level of cadmium for hypertension with high SBP was lower than that of high DBP. PMID:25528411

  18. Establishment of diagnostic reference levels in computed tomography for select procedures in Pudhuchery, India

    PubMed Central

    Saravanakumar, A.; Vaideki, K.; Govindarajan, K. N.; Jayakumar, S.

    2014-01-01

    Computed tomography (CT) scanner under operating conditions has become a major source of human exposure to diagnostic X-rays. In this context, weighed CT dose index (CTDIw), volumetric CT dose index (CTDIv), and dose length product (DLP) are important parameter to assess procedures in CT imaging as surrogate dose quantities for patient dose optimization. The current work aims to estimate the existing dose level of CT scanner for head, chest, and abdomen procedures in Pudhuchery in south India and establish dose reference level (DRL) for the region. The study was carried out for six CT scanners in six different radiology departments using 100 mm long pencil ionization chamber and polymethylmethacrylate (PMMA) phantom. From each CT scanner, data pertaining to patient and machine details were collected for 50 head, 50 chest, and 50 abdomen procedures performed over a period of 1 year. The experimental work was carried out using the machine operating parameters used during the procedures. Initially, dose received in the phantom at the center and periphery was measured by five point method. Using these values CTDIw, CTDIv, and DLP were calculated. The DRL is established based on the third quartile value of CTDIv and DLP which is 32 mGy and 925 mGy.cm for head, 12 mGy and 456 mGy.cm for chest, and 16 mGy and 482 mGy.cm for abdomen procedures. These values are well below European Commission Dose Reference Level (EC DRL) and comparable with the third quartile value reported for Tamil Nadu region in India. The present study is the first of its kind to determine the DRL for scanners operating in the Pudhuchery region. Similar studies in other regions of India are necessary in order to establish a National Dose Reference Level. PMID:24600173

  19. A comparison and cross-reference of commercial low-level radioactive waste acceptance criteria

    SciTech Connect

    Kerr, T.A.

    1997-04-01

    This document, prepared by the National Low-Level Waste Management Program at the Idaho National Engineering and Environmental Laboratory, is a comparison and cross-reference of commercial low-level radioactive waste acceptance criteria. Many of these are draft or preliminary criteria as well as implemented criteria at operating low-level radioactive waste management facilities. Waste acceptance criteria from the following entities are included: US Nuclear Regulatory Commission, South Carolina, Washington, Utah, Nevada, California, illinois, Texas, North Carolina, Nebraska, Pennsylvania, New York, and the Midwest Compact Region. Criteria in the matrix include the following: physical form, chemical form, liquid limits, void space in packages, concentration averaging, types of packaging, chelating agents, solidification media, stability requirements, sorptive media, gas, oil, biological waste, pyrophorics, source material, special nuclear material, package dimensions, incinerator ash, dewatered resin, transuranics, and mixed waste. Each criterion in the matrix is cross-referenced to its source document so that exact requirements can be determined.

  20. Technology, Safety and Costs of Decommissioning a Reference Low-Level Waste Burial Ground. Main Report

    SciTech Connect

    Murphy, E. S.; Holter, G. M.

    1980-06-01

    Safety and cost information are developed for the conceptual decommissioning of commercial low-level waste (LLW) burial grounds. Two generic burial grounds, one located on an arid western site and the other located on a humid eastern site, are used as reference facilities for the study. The two burial grounds are assumed to have the same site capacity for waste, the same radioactive waste inventory, and similar trench characteristics and operating procedures. The climate, geology. and hydrology of the two sites are chosen to be typical of real western and eastern sites. Volume 1 (Main Report) contains background information and study results in summary form.

  1. Technology, Safety and Costs of Decommissioning a Reference Low-Level Waste Burial Ground. Appendices

    SciTech Connect

    1980-06-01

    Safety and cost information are developed for the conceptual decommissioning of commercial low-level waste (LLW) burial grounds. Two generic burial grounds, one located on an arid western site and the other located on a humid eastern site, are used as reference facilities for the study. The two burial grounds are assumed to have the same site capacity for waste, the same radioactive waste inventory, and similar trench characteristics and operating procedures. The climate, geology. and hydrology of the two sites are chosen to be typical of real western and eastern sites. Volume 2 (Appendices) contains the detailed analyses and data needed to support the results given in Volume 1.

  2. Multi-component molecular-level body composition reference methods: evolving concepts and future directions.

    PubMed

    Heymsfield, S B; Ebbeling, C B; Zheng, J; Pietrobelli, A; Strauss, B J; Silva, A M; Ludwig, D S

    2015-04-01

    Excess adiposity is the main phenotypic feature that defines human obesity and that plays a pathophysiological role in most chronic diseases. Measuring the amount of fat mass present is thus a central aspect of studying obesity at the individual and population levels. Nevertheless, a consensus is lacking among investigators on a single accepted 'reference' approach for quantifying fat mass in vivo. While the research community generally relies on the multi-component body volume class of 'reference' models for quantifying fat mass, no definable guide discerns among different applied equations for partitioning the four (fat, water, protein and mineral mass) or more quantified components, standardizes 'adjustment' or measurement system approaches for model-required labelled water dilution volumes and bone mineral mass estimates, or firmly establishes the body temperature at which model physical properties are assumed. The resulting differing reference strategies for quantifying body composition in vivo leads to small, but under some circumstances, important differences in the amount of measured body fat. Recent technological advances highlight opportunities to expand model applications to new subject groups and measured components such as total body protein. The current report reviews the historical evolution of multi-component body volume-based methods in the context of prevailing uncertainties and future potential. PMID:25645009

  3. 88Sr+ 445-THz Single-Ion Reference at the 10-17 Level

    NASA Astrophysics Data System (ADS)

    Madej, Alan

    2013-05-01

    We report experiments and precision measurements on a trapped and laser cooled single ion of 88Sr+ which when probed on the narrow 5 s 2S1/2 - 4 d 2D5/2 transition at 445-THz (674 nm) provides a reference yielding an evaluated fractional inaccuracy of 2.3 × 10-17 and which significantly outperforms the current realization of the SI second. The extremely low systematic shifts obtained are a result of our ability to evaluate, control and in some instances cancel some of the main perturbations that the trapped ion experiences. The fractional uncertainty on the micromotion induced shifts of the trapped ion has been evaluated to better than 1 × 10-18. This is achieved by minimizing any spurious displacement of the ion from trap center using DC trim electrodes and operating the system at a ``magic'' trap frequency where there is anti-correlation between the micromotion induced second order Doppler and Stark shifts resulting in near complete cancellation of this form of perturbation. The electrical quadrupole shift seen in many trapped ion systems is reduced to the 10-19 level by averaging the measured shifts of several pairs of Zeeman components. As in many optical frequency references, the dominant source of uncertainty arises from the blackbody radiation shift. We have been able to reduce the uncertainties associated by this shift using a recent theoretical evaluation of the differential scalar polarizability of the reference transition together with experimental measurements of the trap heating behavior and modeling of the blackbody field at the ion location. The present measurements are performed with resolution of spectral features down to the 4 Hz level (1 part in 1014) together with continuous measurement periods exceeding a few days allowing the possibility for the device to be used as an optical atomic time standard. As part of the effort to link this ultra accurate standard with current time/frequency standards, an absolute frequency measurement of the

  4. Assessment of potential risk levels associated with U.S. Environmental Protection Agency reference values.

    PubMed Central

    Castorina, Rosemary; Woodruff, Tracey J

    2003-01-01

    The U.S. Environmental Protection Agency (U.S. EPA) generally uses reference doses (RfDs) or reference concentrations (RfCs) to assess risks from exposure to toxic substances for noncancer health end points. RfDs and RfCs are supposed to represent lifetime inhalation or ingestion exposure with minimal appreciable risk, but they do not include information about the estimated risk from exposures equal to the RfD/RfC. We used results from benchmark dose modeling approaches recently adopted for use in developing RfDs/RfCs to estimate the risk levels associated with exposures at the RfD/RfC. We searched the U.S. EPA Integrated Risk Information System (IRIS) database and identified 11 chemicals with oral RfDs and 12 chemicals with inhalation RfCs that used benchmark dose modeling. For assessments with sufficient model information, we found that 16 of 21 (76%) of the dose-response models were linear or supralinear. We estimated the risk from exposures at the established RfDs and RfCs for these chemicals using a linear dose-response curve to characterize risk below the observed data. Risk estimates ranged from 1 in 10,000 to 5 in 1,000 for exposures at the RfDs, and from 1 in 10,000 to 3 in 1,000 for exposures at the RfCs. Risk estimates for exposures at the RfD/RfC values derived from sublinear dose-response curves ranged from 3 in 1,000,000,000 to 8 in 10,000. Twenty-four percent of reference values corresponded to estimated risk levels greater than 1 in 1,000; 10 of 14 assessments had points of departure greater than the no-observed-adverse-effect levels. For policy development regarding management of cancer risks, the U.S. EPA often uses 1 in 1,000,000 as a de minimis risk level. Although noncancer outcomes may in some instances be reversible and considered less severe than cancer, our findings call into question the assumption that established RfD and RfC values represent negligibly small risk levels. PMID:12896853

  5. National diagnostic reference level initiative for computed tomography examinations in Kenya.

    PubMed

    Korir, Geoffrey K; Wambani, Jeska S; Korir, Ian K; Tries, Mark A; Boen, Patrick K

    2016-02-01

    The purpose of this study was to estimate the computed tomography (CT) examination frequency, patient radiation exposure, effective doses and national diagnostic reference levels (NDRLs) associated with CT examinations in clinical practice. A structured questionnaire-type form was developed for recording examination frequency, scanning protocols and patient radiation exposure during CT procedures in fully equipped medical facilities across the country. The national annual number of CT examinations per 1000 people was estimated to be 3 procedures. The volume-weighted CT dose index, dose length product, effective dose and NDRLs were determined for 20 types of adult and paediatric CT examinations. Additionally, the CT annual collective effective dose and effective dose per capita were approximated. The radiation exposure during CT examinations was broadly distributed between the facilities that took part in the study. This calls for a need to develop and implement diagnostic reference levels as a standardisation and optimisation tool for the radiological protection of patients at all the CT facilities nationwide. PMID:25790825

  6. Establishment of multi-slice computed tomography (MSCT) reference level in Johor, Malaysia

    NASA Astrophysics Data System (ADS)

    Karim, M. K. A.; Hashim, S.; Bakar, K. A.; Muhammad, H.; Sabarudin, A.; Ang, W. C.; Bahruddin, N. A.

    2016-03-01

    Radiation doses from computed tomography (CT) are the highest and most hazardous compared to other imaging modalities. This study aimed to evaluate radiation dose in Johor, Malaysia to patients during computed tomography examinations of the brain, chest and abdomen and to establish the local diagnostic reference levels (DRLs) as are present with the current, state- of-art, multi-slice CT scanners. Survey forms were sent to five centres performing CT to obtain data regarding acquisition parameters as well as the dose information from CT consoles. CT- EXPO (Version 2.3.1, Germany) was used to validate the dose information. The proposed DRLs were indicated by rounding the third quartiles of whole dose distributions where mean values of CTDIw (mGy), CTDIvol (mGy) and DLP (mGy.cm) were comparable with other reference levels; 63, 63, and 1015 respectively for CT Brain; 15, 14, and 450 respectively for CT thorax and 16, 17, and 590 respectively for CT abdomen. The study revealed that the CT practice and dose output were revolutionised, and must keep up with the pace of introductory technology. We suggest that CTDIvol should be included in current national DRLs, as modern CTs are configured with a higher number of detectors and are independent of pitch factors.

  7. Reference ranges and determinants of total hCG levels during pregnancy: the Generation R Study.

    PubMed

    Korevaar, Tim I M; Steegers, Eric A P; de Rijke, Yolanda B; Schalekamp-Timmermans, Sarah; Visser, W Edward; Hofman, Albert; Jaddoe, Vincent W V; Tiemeier, Henning; Visser, Theo J; Medici, Marco; Peeters, Robin P

    2015-09-01

    Human chorionic gonadotropin (hCG) is a pregnancy hormone secreted by the placental synctiotrophoblast cell layer that has been linked to fetal growth and various placental, uterine and fetal functions. In order to investigate the effects of hCG on clinical endpoints, knowledge on reference range (RR) methodology and determinants of gestational hCG levels is crucial. Moreover, a better understanding of gestational hCG physiology can improve current screening programs and future clinical management. Serum total hCG levels were determined in 8195 women participating in the Generation R Study. Gestational age specific RRs using 'ultrasound derived gestational age' (US RRs) were calculated and compared with 'last menstrual period derived gestational age' (LMP RRs) and a model-based RR. We also investigated which pregnancy characteristics were associated with hCG levels. Compared to the US RRs, the LMP RRs were lower, most notably for the median and lower limit levels. No considerable differences were found between RRs calculated in the general population or in uncomplicated pregnancies only. Maternal smoking, BMI, parity, ethnicity, fetal gender, placental weight and hyperemesis gravidarum symptoms were associated with total hCG. We provide gestational RRs for total hCG and show that total hCG values and RR cut-offs during pregnancy vary depending on pregnancy dating methodology. This is likely due to the influence of hCG on embryonic growth, suggesting that ultrasound based pregnancy dating might be less reliable in women with high/low hCG levels. Furthermore, we identify different pregnancy characteristics that influence total hCG levels considerably and should therefore be accounted for in clinical studies. PMID:25963653

  8. Diagnostic reference levels and patient doses in computed tomography examinations in Greece.

    PubMed

    Simantirakis, G; Hourdakis, C J; Economides, S; Kaisas, I; Kalathaki, M; Koukorava, C; Manousaridis, G; Pafilis, C; Tritakis, P; Vogiatzi, S; Kamenopoulou, V; Dimitriou, P

    2015-02-01

    The purpose of this study is to present a national survey that was performed in Greece for the establishment of national Dose Reference Levels (DRLs) for seven common adult Computed Tomography (CT) examinations. Volumetric computed tomography dose index and dose-length product values were collected from the post-data page of 65 'modern' systems that incorporate tube current modulation. Moreover, phantom dose measurements on 26 'older' systems were performed. Finally, the effective dose to the patient from a typical acquisition during these examinations was estimated. The suggested national DRLs are generally comparable with respective published values from similar European studies, with the exception of sinuses CT, which presents significantly higher values. This fact, along with the large variation of the systems' dose values that were observed even for scanners of the same type, indicates a need for further patient protection optimisation without compromising the clinical outcome. PMID:24891405

  9. Reasoning in Reference Games: Individual- vs. Population-Level Probabilistic Modeling.

    PubMed

    Franke, Michael; Degen, Judith

    2016-01-01

    Recent advances in probabilistic pragmatics have achieved considerable success in modeling speakers' and listeners' pragmatic reasoning as probabilistic inference. However, these models are usually applied to population-level data, and so implicitly suggest a homogeneous population without individual differences. Here we investigate potential individual differences in Theory-of-Mind related depth of pragmatic reasoning in so-called reference games that require drawing ad hoc Quantity implicatures of varying complexity. We show by Bayesian model comparison that a model that assumes a heterogenous population is a better predictor of our data, especially for comprehension. We discuss the implications for the treatment of individual differences in probabilistic models of language use. PMID:27149675

  10. Establishment of diagnostic reference levels in computed tomography for paediatric patients in Sudan: a pilot study.

    PubMed

    Sulieman, A

    2015-07-01

    Paediatric patients are recognised to be at higher risk of developing radiation-induced cancer than adults. The purpose of this pilot study was to evaluate the radiation doses to paediatric patients during computed tomography (CT) procedures in order to propose local diagnostic reference levels (DRLs). A total of 296 patients (aged 6-10 y) were investigated in 8 hospitals equipped with 64-, 16- and dual-slice CT machines. The mean dose length product values were 772, 446 and 178 mGy cm for head, abdomen and chest, respectively. Imaging protocols were not adapted to the patient's weight in certain CT machines. The results confirmed that paediatric patients are exposed to an unnecessary radiation dose. The established DRLs were higher than those available in other countries. This study showed the need for harmonisation of the practice in CT departments and radiation dose optimisation. PMID:25836694

  11. Low-level radioactive waste technology: a selected, annotated bibliography. [416 references

    SciTech Connect

    Fore, C.S.; Carrier, R.F.; Brewster, R.H.; Hyder, L.K.; Barnes, K.A.

    1981-10-01

    This annotated bibliography of 416 references represents the third in a series to be published by the Hazardous Materials Information Center containing scientific, technical, economic, and regulatory information relevant to low-level radioactive waste technology. The bibliography focuses on disposal site, environmental transport, and waste treatment studies as well as general reviews on the subject. The publication covers both domestic and foreign literature for the period 1951 to 1981. Major chapters selected are Chemical and Physical Aspects; Container Design and Performance; Disposal Site; Environmental Transport; General Studies and Reviews; Geology, Hydrology, and Site Resources; Regulatory and Economic Aspects; Social Aspects; Transportation Technology; Waste Production; and Waste Treatment. Entries in each of the chapters are further classified as a field study, laboratory study, theoretical study, or general overview involving one or more of these research areas.

  12. THE APPLICATION OF DIAGNOSTIC REFERENCE LEVELS FOR OPTIMISATION OF X-RAY IMAGING IN THE UK.

    PubMed

    Martin, Colin J

    2016-06-01

    The concept of diagnostic reference levels (DRLs) has been introduced to provide standard doses against which hospital patient dose measurements can be compared to evaluate practices. DRLs are defined in terms of measured dose quantities. National DRLs can be derived from surveys of patient doses for common types of examinations in 20-30 large hospitals. The International Commission on Radiological Protection proposes that median doses for each type of examination at every hospital be collated and DRLs based on the third quartile value of the distribution. Once DRLs have been set, periodic audits of patient dose should be undertaken for examinations that reflect the clinical workload. Median doses from these distributions should be compared with relevant DRLs to identify procedures for which further optimisation is required and appropriate corrective action taken. This paper discusses factors that should be considered in the optimisation process and gives examples of experiences in application of DRLs in Scotland. PMID:26589349

  13. Reasoning in Reference Games: Individual- vs. Population-Level Probabilistic Modeling

    PubMed Central

    Franke, Michael; Degen, Judith

    2016-01-01

    Recent advances in probabilistic pragmatics have achieved considerable success in modeling speakers’ and listeners’ pragmatic reasoning as probabilistic inference. However, these models are usually applied to population-level data, and so implicitly suggest a homogeneous population without individual differences. Here we investigate potential individual differences in Theory-of-Mind related depth of pragmatic reasoning in so-called reference games that require drawing ad hoc Quantity implicatures of varying complexity. We show by Bayesian model comparison that a model that assumes a heterogenous population is a better predictor of our data, especially for comprehension. We discuss the implications for the treatment of individual differences in probabilistic models of language use. PMID:27149675

  14. Developing patient-specific dose protocols for a CT scanner and exam using diagnostic reference levels.

    PubMed

    Strauss, Keith J

    2014-10-01

    The management of image quality and radiation dose during pediatric CT scanning is dependent on how well one manages the radiographic techniques as a function of the type of exam, type of CT scanner, and patient size. The CT scanner's display of expected CT dose index volume (CTDIvol) after the projection scan provides the operator with a powerful tool prior to the patient scan to identify and manage appropriate CT techniques, provided the department has established appropriate diagnostic reference levels (DRLs). This paper provides a step-by-step process that allows the development of DRLs as a function of type of exam, of actual patient size and of the individual radiation output of each CT scanner in a department. Abdomen, pelvis, thorax and head scans are addressed. Patient sizes from newborns to large adults are discussed. The method addresses every CT scanner regardless of vendor, model or vintage. We cover adjustments to techniques to manage the impact of iterative reconstruction and provide a method to handle all available voltages other than 120 kV. This level of management of CT techniques is necessary to properly monitor radiation dose and image quality during pediatric CT scans. PMID:25037975

  15. SU-E-P-10: Establishment of Local Diagnostic Reference Levels of Routine Exam in Computed Tomography

    SciTech Connect

    Yeh, M; Wang, Y; Weng, H

    2015-06-15

    Introduction National diagnostic reference levels (NDRLs) can be used as a reference dose of radiological examination can provide radiation dose as the basis of patient dose optimization. Local diagnostic reference levels (LDRLs) by periodically view and check doses, more efficiency to improve the way of examination. Therefore, the important first step is establishing a diagnostic reference level. Computed Tomography in Taiwan had been built up the radiation dose limit value,in addition, many studies report shows that CT scan contributed most of the radiation dose in different medical. Therefore, this study was mainly to let everyone understand DRL’s international status. For computed tomography in our hospital to establish diagnostic reference levels. Methods and Materials: There are two clinical CT scanners (a Toshiba Aquilion and a Siemens Sensation) were performed in this study. For CT examinations the basic recommended dosimetric quantity is the Computed Tomography Dose Index (CTDI). Each exam each different body part, we collect 10 patients at least. Carried out the routine examinations, and all exposure parameters have been collected and the corresponding CTDIv and DLP values have been determined. Results: The majority of patients (75%) were between 60–70 Kg of body weight. There are 25 examinations in this study. Table 1 shows the LDRL of each CT routine examination. Conclusions: Therefore, this study would like to let everyone know DRL’s international status, but also establishment of computed tomography of the local reference levels for our hospital, and providing radiation reference, as a basis for optimizing patient dose.

  16. Global Reference Frame Realization on National Level Based on the Integration of National CORS Networks

    NASA Astrophysics Data System (ADS)

    Kenyeres, A.; Caporali, A.; Horvath, T.; Baron, A.; Doncker, F. D.; Droscak, B.; Duret, A.; Franke, P.; Georgiev, I.; Gianniou, M.; Hansen, D.; Huisman, L.; Morozova, K.; Nagl, J.; Pihlak, P.; Stangl, G.; Valdes, M.; Ryczywolski, M.; Zurutuza, J.

    2015-12-01

    The national permanent GNSS networks are not only serving the general surveying practice in real-time mode, but they are deployed at reference frame maintenance and geodynamic studies relying on their homogeneously analyzed long-term data series. The ongoing EPN (EUREF Permanent Network) densification targets the integration of the national CORS networks and a homogeneous, dense position and velocity product is derived using the EPN as backbone infrastructure. The homogeneous cumulative solution relies on the national weekly SINEX products in order to minimize inconsistencies (e.g. site naming, discontinuities). The integration is done with the CATREF software (Altamimi et al, IGN) using the Minimum Constraint approach. The derived position and velocity product will be an essential material for various geokinematic studies (PGR, intraplate and plate boundary zone investigations), and also for the better realization of ETRS89 over tectonically active regions. This work is very well inline with the goals of other European initiatives as EPOS and EUPOS. The preparatory work is well in progress, several years of weekly SINEX files are already available and analyzed. The database contains more than 2000 stations stemming from 15 contributing Analysis Centres. A significant effort is devoted to the cleaning and organization of the station metadata and publish on the EPNCB website, which is necessary to improve the quality and reliabilty of the combination product.This presentation, beyond the publication of the state-of the-art combination results partly focuses on the analysis of existing reference frame realization issues caused by the GNSS antenna PCV updates not yet eliminated on the national CORS level.

  17. A study to establish international diagnostic reference levels for paediatric computed tomography.

    PubMed

    Vassileva, J; Rehani, M; Kostova-Lefterova, D; Al-Naemi, H M; Al Suwaidi, J S; Arandjic, D; Bashier, E H O; Kodlulovich Renha, S; El-Nachef, L; Aguilar, J G; Gershan, V; Gershkevitsh, E; Gruppetta, E; Hustuc, A; Jauhari, A; Kharita, Mohammad Hassan; Khelassi-Toutaoui, N; Khosravi, H R; Khoury, H; Kralik, I; Mahere, S; Mazuoliene, J; Mora, P; Muhogora, W; Muthuvelu, P; Nikodemova, D; Novak, L; Pallewatte, A; Pekarovič, D; Shaaban, M; Shelly, E; Stepanyan, K; Thelsy, N; Visrutaratna, P; Zaman, A

    2015-07-01

    The article reports results from the largest international dose survey in paediatric computed tomography (CT) in 32 countries and proposes international diagnostic reference levels (DRLs) in terms of computed tomography dose index (CTDI vol) and dose length product (DLP). It also assesses whether mean or median values of individual facilities should be used. A total of 6115 individual patient data were recorded among four age groups: <1 y, >1-5 y, >5-10 y and >10-15 y. CTDIw, CTDI vol and DLP from the CT console were recorded in dedicated forms together with patient data and technical parameters. Statistical analysis was performed, and international DRLs were established at rounded 75th percentile values of distribution of median values from all CT facilities. The study presents evidence in favour of using median rather than mean of patient dose indices as the representative of typical local dose in a facility, and for establishing DRLs as third quartile of median values. International DRLs were established for paediatric CT examinations for routine head, chest and abdomen in the four age groups. DRLs for CTDI vol are similar to the reference values from other published reports, with some differences for chest and abdomen CT. Higher variations were observed between DLP values, based on a survey of whole multi-phase exams. It may be noted that other studies in literature were based on single phase only. DRLs reported in this article can be used in countries without sufficient medical physics support to identify non-optimised practice. Recommendations to improve the accuracy and importance of future surveys are provided. PMID:25836685

  18. Dose Assessment in Computed Tomography Examination and Establishment of Local Diagnostic Reference Levels in Mazandaran, Iran

    PubMed Central

    Janbabanezhad Toori, A.; Shabestani-Monfared, A.; Deevband, M.R.; Abdi, R.; Nabahati, M.

    2015-01-01

    Background Medical X-rays are the largest man-made source of public exposure to ionizing radiation. While the benefits of Computed Tomography (CT) are well known in accurate diagnosis, those benefits are not risk-free. CT is a device with higher patient dose in comparison with other conventional radiation procedures. Objective This study is aimed at evaluating radiation dose to patients from Computed Tomography (CT) examination in Mazandaran hospitals and defining diagnostic reference level (DRL). Methods Patient-related data on CT protocol for four common CT examinations including brain, sinus, chest and abdomen & pelvic were collected. In each center, Computed Tomography Dose Index (CTDI) measurements were performed using pencil ionization chamber and CT dosimetry phantom according to AAPM report No. 96 for those techniques. Then, Weighted Computed Tomography Dose Index (CTDIW), Volume Computed Tomography Dose Index (CTDI vol) and Dose Length Product (DLP) were calculated. Results The CTDIw for brain, sinus, chest and abdomen & pelvic ranged (15.6-73), (3.8-25. 8), (4.5-16.3) and (7-16.3), respectively. Values of DLP had a range of (197.4-981), (41.8-184), (131-342.3) and (283.6-486) for brain, sinus, chest and abdomen & pelvic, respectively. The 3rd quartile of CTDIW, derived from dose distribution for each examination is the proposed quantity for DRL. The DRLs of brain, sinus, chest and abdomen & pelvic are measured 59.5, 17, 7.8 and 11 mGy, respectively. Conclusion Results of this study demonstrated large scales of dose for the same examination among different centers. For all examinations, our values were lower than international reference doses. PMID:26688796

  19. Derivation of a reference dose and drinking water equivalent level for 1,2,3-trichloropropane.

    PubMed

    Tardiff, Robert G; Carson, M Leigh

    2010-06-01

    In some US potable water supplies, 1,2,3-trichloropropane (TCP) has been present at ranges of non-detect to less than 100 ppb, resulting from past uses. In subchronic oral studies, TCP produced toxicity in kidneys, liver, and other tissues. TCP administered by corn oil gavage in chronic studies produced tumors at multiple sites in rats and mice; however, interpretation of these studies was impeded by substantial premature mortality. Drinking water equivalent levels (DWELs) were estimated for a lifetime of consumption by applying biologically-based safety/risk assessment approaches, including Monte Carlo techniques, and with consideration of kinetics and modes of action, to possibly replace default assumptions. Internationally recognized Frameworks for human relevance of animal data were employed to interpret the findings. Calculated were a reference dose (=39 microg/kg d) for non-cancer and Cancer Values (CV) (=10-14 microg/kg d) based on non-linear dose-response relationships for mutagenicity as a precursor of cancer. Lifetime Average Daily Intakes (LADI) are 3130 and 790-1120 microg/person-d for non-cancer and cancer, respectively. DWELs, estimated by applying a relative source contribution (RSC) of 50% to the LADIs, are 780 and 200-280 microg/L for non-cancer and cancer, respectively. These DWELs may inform establishment of formal/informal guidelines and standards to protect public health. PMID:20303376

  20. Diagnostic reference levels for panoramic and lateral cephalometric radiography of Korean children.

    PubMed

    Kim, Young-Hee; Yang, Byoung-Eun; Yoon, Suk-Ja; Kang, Byung-Cheol; Lee, Jae-Seo

    2014-08-01

    Pediatric patients are considered to be more radiosensitive than adults; thus, radiation dose evaluations based on radiologic examinations are particularly important in this population. However, no national diagnostic reference levels (DRLs) are available for pediatric patients in the Republic of Korea. Therefore, the aim of this study was to determine the usage of panoramic and cephalometric radiography under the National Health Insurance (NHI) scheme and to investigate the current DRLs for child panoramic and lateral cephalometric radiography using dose area product (DAP). DAP values were obtained for standard child exposure settings used routinely by dentists. Analysis was performed on data obtained from 28 panoramic and 20 cephalometric x-ray units for the DAP investigation. DRLs for child panoramic and cephalometric radiography were found to be 95.9 mGy cm and 121.3 mGy cm, respectively. These DRLs are higher than those recommended in the UK and Germany, which indicates that further effort is required to reduce pediatric doses in the Republic of Korea. PMID:24978282

  1. Multi-Component Molecular-Level Body Composition Reference Methods: Evolving Concepts and Future Directions

    PubMed Central

    Heymsfield, Steven B.; Ebbeling, Cara B.; Zheng, Jolene; Pietrobelli, Angelo; Strauss, Boyd J.; Silva, Analiza M.; Ludwig, David S.

    2015-01-01

    Excess adiposity is the main phenotypic feature that defines human obesity and that plays a pathophysiological role in most chronic diseases. Measuring the amount of fat mass present is thus a central aspect of studying obesity at the individual and population levels. Nevertheless, a consensus is lacking among investigators on a single accepted “reference” approach for quantifying fat mass in vivo. While the research community generally relies on the multicomponent body-volume class of “reference” models for quantifying fat mass, no definable guide discerns among different applied equations for partitioning the four (fat, water, protein, and mineral mass) or more quantified components, standardizes “adjustment” or measurement system approaches for model-required labeled water dilution volumes and bone mineral mass estimates, or firmly establishes the body temperature at which model physical properties are assumed. The resulting differing reference strategies for quantifying body composition in vivo leads to small but under some circumstances important differences in the amount of measured body fat. Recent technological advances highlight opportunities to expand model applications to new subject groups and measured components such as total body protein. The current report reviews the historical evolution of multicomponent body volume-based methods in the context of prevailing uncertainties and future potential. PMID:25645009

  2. Establishment of diagnostic reference levels for dental panoramic radiography in Greece.

    PubMed

    Manousaridis, G; Koukorava, C; Hourdakis, C J; Kamenopoulou, V; Yakoumakis, E; Tsiklakis, K

    2015-07-01

    The purpose of the present study was to present the national diagnostic reference levels (DRL) established for panoramic dental examinations in Greece. The establishment of DRL, as a tool for the optimisation of radiological procedures, is a requirement of national regulations. Measurements performed by the Greek Atomic Energy Commission on 90 panoramic systems have been used for the derivation of DRL values. DRL values have been proposed for exposure settings of different patient types (child, small adult and standard adult), both for film and digital imaging. The DRLs for different patient types are grouped in three categories: children, small adults (corresponding to female) and average adults (corresponding to male). Proposed DRLs for these groups are 2.2, 3.3 and 4.1 mGy, respectively. In order to investigate the correlation of DRLs with the available imaging modalities (CR, DR and film), this parameter was taken into account. DR imaging DRL is the lowest at 3.5 mGy, CR imaging the highest at 4.2 mGy and film imaging at 3.7 mGy. In order to facilitate comparison with other studies, kerma-width product values were calculated from Ki, air and field size. PMID:25836684

  3. Estimating the population dose from nuclear medicine examinations towards establishing diagnostic reference levels

    PubMed Central

    Niksirat, Fatemeh; Monfared, Ali Shabestani; Deevband, Mohammad Reza; Amiri, Mehrangiz; Gholami, Amir

    2016-01-01

    Purpose of the Study: This study conducted a review on nuclear medicine (NM) services in Mazandaran Province with a view to establish adult diagnostic reference levels (DRLs) and provide updated data on population radiation exposure resulting from diagnostic NM procedures. Materials and Methods: The data were collected from all centers in all cities of Mazandaran Province in the North of Iran from March 2014 to February 2015. The 75th percentile of the distribution and the average administered activity (AAA) were calculated and the average effective dose per examination, collective effective dose to the population and annual effective dose per capita were estimated using dose conversion factors. The gathered data were analyzed via SPSS (version 18) software using descriptive statistics. Results: Based on the data of this study, the collective effective dose was 95.628 manSv, leading to a mean effective dose of 0.03 mSv per capita. It was also observed that the myocardial perfusion was the most common procedure (50%). The 75th percentile of the distribution of administered activity (AA) represents the DRL. The AAA and the 75th percentile of the distribution of AA are slightly higher than DRL of most European countries. Conclusions: Myocardial perfusion is responsible for most of the collective effective dose and it is better to establish national DRLs for myocardial perfusion and review some DRL values through the participation of NM specialists in the future. PMID:26917891

  4. Advancing reference emission levels in subnational and national REDD+ initiatives: a CLASlite approach

    PubMed Central

    2015-01-01

    Conservation and monitoring of tropical forests requires accurate information on their extent and change dynamics. Cloud cover, sensor errors and technical barriers associated with satellite remote sensing data continue to prevent many national and sub-national REDD+ initiatives from developing their reference deforestation and forest degradation emission levels. Here we present a framework for large-scale historical forest cover change analysis using free multispectral satellite imagery in an extremely cloudy tropical forest region. The CLASlite approach provided highly automated mapping of tropical forest cover, deforestation and degradation from Landsat satellite imagery. Critically, the fractional cover of forest photosynthetic vegetation, non-photosynthetic vegetation, and bare substrates calculated by CLASlite provided scene-invariant quantities for forest cover, allowing for systematic mosaicking of incomplete satellite data coverage. A synthesized satellite-based data set of forest cover was thereby created, reducing image incompleteness caused by clouds, shadows or sensor errors. This approach can readily be implemented by single operators with highly constrained budgets. We test this framework on tropical forests of the Colombian Pacific Coast (Chocó) – one of the cloudiest regions on Earth, with successful comparison to the Colombian government’s deforestation map and a global deforestation map. PMID:25678933

  5. Out of Cite! How Reference Managers Are Taking Research to the Next Level

    ERIC Educational Resources Information Center

    Muldrow, Jason; Yoder, Stephen

    2009-01-01

    Times change, and so do research methods; gone are the days of researching with index cards. While academics may be slow to adopt emerging citation technology, the reference manager field is blazing ahead. This article explains what reference managers are, addresses their emergence in and potential impact on academe, and profiles a newcomer to the…

  6. Assessing the Bibliographic Instruction Skills Needed for Entry-Level Reference Positions in Academic Libraries.

    ERIC Educational Resources Information Center

    Moegling, Mary Lou

    The purpose of this study is to determine responsibilities expected of newly-hired academic reference librarians and background experiences they are expected to possess. The content analysis of 3 months' worth of reference librarian job listings from three 1990 issues of "College & Research Library News" led to a profile of expectations for…

  7. Preliminary diagnostic reference levels for endoscopic retrograde cholangio-pancreatography in Greece.

    PubMed

    Tsapaki, V; Delinikolas, P; Paraskeva, K D; Paspatis, I A G; Scotiniotis, H; Georgopoulos, P; Voudoukis, E; Finou, P; Athanasopoulos, N; Lydakis, I; Giannakopoulos, A; Mathou, N; Angelogiannakopoulou, N; Triantopoulou, C; Karagiannis, J A

    2016-04-01

    The main objective of this study was to determine the preliminary Diagnostic Reference Levels (DRLs) in terms of Kerma Area Product (KAP) and fluoroscopy time (Tf) during Endoscopic Retrograde Cholangio-Pancreatography (ERCP) procedures. Additionally, an investigation was conducted to explore the statistical relation between KAP and Tf. Data from a set of 200 randomly selected patients treated in 4 large hospitals in Greece (50 patients per hospital) were analyzed in order to obtain preliminary DRLs for KAP and Tf during therapeutic ERCP procedures. Non-parametric statistic tests were performed in order to determine a statistically significant relation between KAP and Tf. The resulting third quartiles for KAP and Tf for hospitals (A, B, C and D) were found as followed: KAPA=10.7Gycm(2), TfA=4.9min; KAPB=7.5Gycm(2), TfB=5.0min; KAPC=19.0Gycm(2), TfC=7.3min; KAPD=52.4Gycm(2), TfD=15.8min. The third quartiles, calculated for the total 200 cases sample, are: KAP=18.8Gycm(2) and Tf=8.2min. For 3 out of 4 hospitals and for the total sample, p-values of statistical indices (correlation of KAP and Tf) are less than 0.001, while for the Hospital A p-values are ranging from 0.07 to 0.08. Using curve fitting, we finally determine that the relation of Tf and KAP is deriving from a power equation (KAP=Tf(1.282)) with R(2)=0.85. The suggested Preliminary DRLs (deriving from the third quartiles of the total sample) for Greece are: KAP=19Gycm(2) and Tf=8min, while the relation between KAP and Tf is efficiently described by a power equation. PMID:27068273

  8. Towards proposition of a diagnostic reference level for mammographic examination in the greater Khorasan Province, Iran.

    PubMed

    Bahreyni Toossi, M T; Zare, H; Bayani Roodi, Sh; Hashemi, M; Akbari, F; Malekzadeh, M

    2013-06-01

    Although, over the past few years, the application of mammography has risen up sharply in Iran, very little, if any, has been reported of the extent of patient's dose from this type of imaging. The purpose of this study was to establish local diagnostic reference level (DRL) arising from mammography in the great Khorasan province of Iran. It is generally assumed that the glandular tissue is the most vulnerable type of breast tissue. Therefore, the mean glandular dose (MGD) has been widely accepted as the most appropriate dosimetric quantity to predict the risk of radiation-induced cancer. Literary, DRL for mammography is defined as the 75th percentile of MGD distribution. In Khorasan province, 7 out of 40 centres were randomly selected. In this work, 100 patients were studied. Thermoluminescence dosimeters have been used to measure entrance surface doses (ESDs). Since, it is difficult to directly measure MGD, Monte Carlo model-based conversion factors were utilised to conclude MGD from ESD. The results have revealed that patients dose is varied widely. The measured ESDs ranged from 0.74 to 19.81 mGy for the craniocaudal (CC) view and 1.20 to 25.79 mGy for the mediolateral oblique (MLO) view. The average MGDs per image were 0.88 and 1.11 mGy for CC and MLO views, respectively. Based on the internationally adopted definition, DRL arising from mammography tests for Khorasan is 1.33 mGy. Implementation of a dose reduction programme is suggested because of the large variations observed in patient MGD values. In this study, the DRL value is significantly lower than the corresponding values suggested by other researchers elsewhere. PMID:23209184

  9. SU-E-I-33: Establishment of CT Diagnostic Reference Levels in Province Nova Scotia

    SciTech Connect

    Tonkopi, E; Abdolell, M; Duffy, S

    2015-06-15

    Purpose: To evaluate patient radiation dose from the most frequently performed CT examinations and to establish provincial diagnostic reference levels (DRLs) as a tool for protocol optimization. Methods: The study investigated the following CT examinations: head, chest, abdomen/pelvis, and chest/abdomen/pelvis (CAP). Dose data, volume CT dose index (CTDIvol) and dose-length product (DLP), were collected from 15 CT scanners installed during 2004–2014 in 11 hospital sites of Nova Scotia. All scanners had dose modulation options and multislice capability (16–128 detector rows). The sample for each protocol included 15 average size patients (70±20 kg). Provincial DRLs were calculated as the 75th percentile of patient dose distributions. The differences in dose between hospitals were evaluated with a single factor ANOVA statistical test. Generalized linear modeling was used to determine the factors associated with higher radiation dose. A sample of 36 abdominal studies performed on three different scanners was blinded and randomized for an assessment by an experienced radiologist who graded the imaging quality of anatomic structures. Results: Data for 900 patients were collected. The DRLs were proposed using CTDIvol (mGy) and DLP (mGy*cm) values for CT head (67 and 1049, respectively), chest (12 and 393), abdomen/pelvis (16 and 717), and CAP (14 and 1034). These DRLs were lower than the published national data except for the head CTDIvol. The differences between the means of the dose distributions from each scanner were statistically significant (p<0.05) for all examinations. A very weak correlation was found between the dose and the scanner age or the number of slices with Pearson’s correlation coefficients of 0.011–0.315. The blinded analysis of image quality demonstrated no clinically significant difference except for the noise category. Conclusion: Provincial DRLs were established for typical CT examinations. The variations in dose between the hospitals

  10. Validation of reference genes for real-time quantitative PCR studies in gene expression levels of Lactobacillus casei Zhang.

    PubMed

    Zhao, Wenjing; Li, Yan; Gao, Pengfei; Sun, Zhihong; Sun, Tiansong; Zhang, Heping

    2011-09-01

    Lactobacillus casei Zhang, a potential probiotic strain isolated from homemade koumiss in Inner Mongolia of China, has been sequenced and deposited in GenBank. Real-time quantitative PCR is one of the most widely used methods to study related gene expression levels of Lactobacillus casei Zhang. For accurate and reliable gene expression analysis, normalization of gene expression data using one or more appropriate reference genes is essential. We used three statistical methods (geNorm, NormFinder, and BestKeeper) to evaluate the expression levels of five candidate reference genes (GAPD, gyrB, LDH, 16s rRNA, and recA) under different culture conditions and different growth phases to find a suitable housekeeping gene which can be used as internal standard. The results showed that the best reference gene was GAPD, and a set of two genes, GAPD and gyrB (which were the most stable reference genes), is recommended for normalization of real-time quantitative PCR experiments under all the different experimental conditions tested. The systematic validation of candidate reference genes is important for obtaining reliable analysis results of real-time quantitative PCR studies in gene expression levels of Lactobacillus casei Zhang. PMID:21104423

  11. 23 CFR Appendix A to Part 772 - National Reference Energy Mean Emission Levels as a Function of Speed

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false National Reference Energy Mean Emission Levels as a Function of Speed A Appendix A to Part 772 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF... Function of Speed EC14OC91.013...

  12. The Relationship Between Global Mean Sea Level Rise and the Reference Frame

    NASA Technical Reports Server (NTRS)

    Lemoine, F.; Luthcke, S.; Zelensky, N.; Pavlis, E.; Beckley, B.; Ray, R.; Petrov, L.; Pavlis, D.; Rowlands, D.

    2006-01-01

    The Terrestrial Reference Frame is the fundamental means by which we relate observations in space and time. For example, in order to generate a homogeneous and consistent time series of geo-referenced altimeter measurements over the span of the Topex/Poseidon and Jason-1 missions, we must examine carefully the role of improvements in measurement modelling, force modelling, and improved reference frame realizations. In this paper, we quantify the effects of improvements in force modelling, for example the use of new GRACE-derived gravity models, the effect of time-variable gravity derived from GRACE on altimeter satellite orbits. In addition, we examine the effects of modelling geocenter in altimeteric satellite POD, and look at how the application of atmospheric loading might affect the time-series of precise orbits for Topex/Poseidon and Jason-1.

  13. The impact of reference gene selection in quantification of gene expression levels in guinea pig cervical tissues and cells

    PubMed Central

    2013-01-01

    Background Accurate measurements of mRNA expression levels in tissues or cells are crucially dependent on the use of relevant reference genes for normalization of data. In this study we used quantitative real-time PCR and two Excel-based applets (geNorm and BestKeeper) to determine the best reference genes for quantification of target gene mRNA in a complex tissue organ such as the guinea pig cervix. Results Gene expression studies were conducted in cervical epithelium and stroma during pregnancy and parturition and in cultures of primary cells from this tissue. Among 15 reference gene candidates examined, both geNorm and BestKeeper found CLF1 and CLTC to be the most stable in cervical stroma and cervical epithelium, ACTB and PPIB in primary stroma cells, and CLTC and PPIB in primary epithelial cells. The order of stability among the remaining candidate genes was not in such an agreement. Commonly used reference such as GAPDH and B2M demonstrated lower stability. Determination of pairwise variation values for reference gene combinations using geNorm revealed that the geometric mean of the two most stable genes provides sufficient normalization in most cases. However, for cervical stroma tissue in which many reference gene candidates displayed low stability, inclusion of three reference genes in the geometric mean may improve accuracy of target gene expression level analyses. Using the top ranked reference genes we examined the expression levels of target gene PTGS2 in cervical tissue and cultured cervical cells. We compared the results with PTGS2 expression normalized to the least stable gene and found significant differences in gene expression, up to 10-fold in some samples, emphasizing the importance of appropriately selecting reference genes. Conclusions We recommend using the geometric mean of CFL1 and CLTC for normalization of qPCR studies in guinea pig cervical tissue studies, ACTB and PPIB in primary stroma cells and CLTC and PPIB in primary epithelial cells

  14. Parallel implementation of multireference coupled-cluster theories based on the reference-level parallelism

    SciTech Connect

    Brabec, Jiri; Pittner, Jiri; van Dam, Hubertus JJ; Apra, Edoardo; Kowalski, Karol

    2012-02-01

    A novel algorithm for implementing general type of multireference coupled-cluster (MRCC) theory based on the Jeziorski-Monkhorst exponential Ansatz [B. Jeziorski, H.J. Monkhorst, Phys. Rev. A 24, 1668 (1981)] is introduced. The proposed algorithm utilizes processor groups to calculate the equations for the MRCC amplitudes. In the basic formulation each processor group constructs the equations related to a specific subset of references. By flexible choice of processor groups and subset of reference-specific sufficiency conditions designated to a given group one can assure optimum utilization of available computing resources. The performance of this algorithm is illustrated on the examples of the Brillouin-Wigner and Mukherjee MRCC methods with singles and doubles (BW-MRCCSD and Mk-MRCCSD). A significant improvement in scalability and in reduction of time to solution is reported with respect to recently reported parallel implementation of the BW-MRCCSD formalism [J.Brabec, H.J.J. van Dam, K. Kowalski, J. Pittner, Chem. Phys. Lett. 514, 347 (2011)].

  15. An investigation of sound levels on intensive care units with reference to the WHO guidelines

    PubMed Central

    2013-01-01

    Introduction Patients in intensive care units (ICUs) suffer from sleep deprivation arising from nursing interventions and ambient noise. This may exacerbate confusion and ICU-related delirium. The World Health Organization (WHO) suggests that average hospital sound levels should not exceed 35 dB with a maximum of 40 dB overnight. We monitored five ICUs to check compliance with these guidelines. Methods Sound levels were recorded in five adult ICUs in the UK. Two sound level monitors recorded concurrently for 24 hours at the ICU central stations and adjacent to patients. Sample values to determine levels generated by equipment and external noise were also recorded in an empty ICU side room. Results Average sound levels always exceeded 45 dBA and for 50% of the time exceeded between 52 and 59 dBA in individual ICUs. There was diurnal variation with values decreasing after evening handovers to an overnight average minimum of 51 dBA at 4 AM. Peaks above 85 dBA occurred at all sites, up to 16 times per hour overnight and more frequently during the day. WHO guidelines on sound levels could be only achieved in a side room by switching all equipment off. Conclusion All ICUs had sound levels greater than WHO recommendations, but the WHO recommended levels are so low they are not achievable in an ICU. Levels adjacent to patients are higher than those recorded at central stations. Unit-wide noise reduction programmes or mechanical means of isolating patients from ambient noise, such as earplugs, should be considered. PMID:24005004

  16. Reference range levels of polycyclic aromatic hydrocarbons in the US population by measurement of urinary monohydroxy metabolites

    SciTech Connect

    Grainger, James . E-mail: jag2@cdc.gov; Huang, Wenlin; Patterson, Donald G.; Turner, Wayman E.; Pirkle, James; Caudill, Samuel P.; Wang, Richard Y.; Needham, Larry L.; Sampson, Eric J.

    2006-03-15

    We developed a gas chromatography isotope-dilution high-resolution mass spectrometry (GC/Id-HRMS) method for measuring 14 polycyclic aromatic hydrocarbon (PAH) metabolites representing seven parent PAHs in 3 mL of urine at low parts-per-trillion levels. PAH levels were determined in urine samples collected in 1999 and 2000 from approximately 2400 participants in the National Health and Nutrition Examination Survey, and, for the first time, reference range values were calculated for these metabolites in the US population. Using this GC/ID-HRMS method, we found detectable concentrations for monohydroxy metabolite isomers of fluorene, phenanthrene, fluoranthene, pyrene, and chrysene, benzo[c]phenanthrene, and benz[a]anthracene. Some monohydroxy metabolite isomers of benzo[c]phenanthrene, chrysene, and benz[a]anthracene exhibited low detection frequencies that did not allow for geometric mean calculations. Our study results enabled us to establish a reference range for the targeted PAHs in the general US population.

  17. DEVELOPMENT OF TOXICITY REFERENCE VALUES FOR ECOLOGICAL SOIL SCREENING LEVELS (ECO-SSLS) FOR TERRESTRIAL WILDLIFE

    EPA Science Inventory

    Ecological Soil Screening Levels (Eco-SSLs) protective of terrestrial wildlife were developed by the USEPA Superfund. The wildlife Eco-SSL is the soil contaminant concentration where the Effect Dose (TRV) and Exposure Dose are equal (amount of contaminant in the diet that is take...

  18. Airport-Noise Levels and Annoyance Model (ALAMO) system's reference manual

    NASA Technical Reports Server (NTRS)

    Deloach, R.; Donaldson, J. L.; Johnson, M. J.

    1986-01-01

    The airport-noise levels and annoyance model (ALAMO) is described in terms of the constituent modules, the execution of ALAMO procedure files, necessary for system execution, and the source code documentation associated with code development at Langley Research Center. The modules constituting ALAMO are presented both in flow graph form, and through a description of the subroutines and functions that comprise them.

  19. Educational level and risk of colorectal cancer in EPIC with specific reference to tumor location.

    PubMed

    Leufkens, Anke M; Van Duijnhoven, Fränzel J B; Boshuizen, Hendriek C; Siersema, Peter D; Kunst, Anton E; Mouw, Traci; Tjønneland, Anne; Olsen, Anja; Overvad, Kim; Boutron-Ruault, Marie-Christine; Clavel-Chapelon, Françoise; Morois, Sophie; Krogh, Vittorio; Tumino, Rosario; Panico, Salvatore; Polidoro, Silvia; Palli, Domenico; Kaaks, Rudolf; Teucher, Birgit; Pischon, Tobias; Trichopoulou, Antonia; Orfanos, Philippos; Goufa, Ioulia; Peeters, Petra H M; Skeie, Guri; Braaten, Tonje; Rodríguez, Laudina; Lujan-Barroso, Leila; Sánchez-Pérez, Maria-José; Navarro, Carmen; Barricarte, Aurelio; Zackrisson, Sophia; Almquist, Martin; Hallmans, Goran; Palmqvist, Richard; Tsilidis, Konstantinos K; Khaw, Kay-Tee; Wareham, Nick; Gallo, Valentina; Jenab, Mazda; Riboli, Elio; Bueno-de-Mesquita, H Bas

    2012-02-01

    Existing evidence is inconclusive on whether socioeconomic status (SES) and educational inequalities influence colorectal cancer (CRC) risk, and whether low or high SES/educational level is associated with developing CRC. The aim of our study was to investigate the relationship between educational level and CRC. We studied data from 400,510 participants in the EPIC (European Prospective Investigation into Cancer and Nutrition) study, of whom 2,447 developed CRC (colon: 1,551, rectum: 896, mean follow-up 8.3 years). Cox proportional hazard regression analysis stratified by age, gender and center, and adjusted for potential confounders were used to estimate hazard ratios (HR) and 95% confidence intervals (95%CI). Relative indices of inequality (RII) for education were estimated using Cox regression models. We conducted separate analyses for tumor location, gender and geographical region. Compared with participants with college/university education, participants with vocational secondary education or less had a nonsignificantly lower risk of developing CRC. When further stratified for tumor location, adjusted risk estimates for the proximal colon were statistically significant for primary education or less (HR 0.73, 95%CI 0.57-0.94) and for vocational secondary education (HR 0.76, 95%CI 0.58-0.98). The inverse association between low education and CRC risk was particularly found in women and Southern Europe. These associations were statistically significant for CRC, for colon cancer and for proximal colon cancer. In conclusion, CRC risk, especially in the proximal colon, is lower in subjects with a lower educational level compared to those with a higher educational level. This association is most pronounced in women and Southern Europe. PMID:21412763

  20. Levels of representation in the interpretation of anaphoric reference and instrument inference.

    PubMed

    Lucas, M M; Tanenhaus, M K; Carlson, G N

    1990-11-01

    The level of representation accessed when inferences are made during sentence comprehension was examined. The inferences investigated included antecedent assignment for both definite noun phrase anaphors and pronouns and also instrument inferences. In making these inferences, a listener must access the inferred element, whether an antecedent or an instrument, in either a linguistic form representation or a discourse model. The level of representation involved in these inferences was determined by exploiting differences in the lexical decision and naming tasks, which were argued to exhibit differential sensitivity to representational levels. In three experiments, the priming of antecedent and instrument targets in the lexical decision task was compared with priming of the same targets in the naming task. Differences in the patterns of activation across the two tasks indicated that all three types of inferences required accessing elements in a discourse model. Three control experiments ruled out simple context or congruity checking as an explanation for our results. The following conclusions were also supported by these studies: (1) Antecedent assignment occurs immediately after processing an anaphor; (2) antecedent assignment involves inhibition for the inappropriate antecedent rather than facilitation for the appropriate antecedent; (3) although subjects do not make instrument inferences when they hear isolated sentences containing verbs that strongly imply certain instruments, the inferences are made when sentences are preceded by a context that mentions the instrument. PMID:2266863

  1. Centimeter-Level Robust Gnss-Aided Inertial Post-Processing for Mobile Mapping Without Local Reference Stations

    NASA Astrophysics Data System (ADS)

    Hutton, J. J.; Gopaul, N.; Zhang, X.; Wang, J.; Menon, V.; Rieck, D.; Kipka, A.; Pastor, F.

    2016-06-01

    For almost two decades mobile mapping systems have done their georeferencing using Global Navigation Satellite Systems (GNSS) to measure position and inertial sensors to measure orientation. In order to achieve cm level position accuracy, a technique referred to as post-processed carrier phase differential GNSS (DGNSS) is used. For this technique to be effective the maximum distance to a single Reference Station should be no more than 20 km, and when using a network of Reference Stations the distance to the nearest station should no more than about 70 km. This need to set up local Reference Stations limits productivity and increases costs, especially when mapping large areas or long linear features such as roads or pipelines. An alternative technique to DGNSS for high-accuracy positioning from GNSS is the so-called Precise Point Positioning or PPP method. In this case instead of differencing the rover observables with the Reference Station observables to cancel out common errors, an advanced model for every aspect of the GNSS error chain is developed and parameterized to within an accuracy of a few cm. The Trimble Centerpoint RTX positioning solution combines the methodology of PPP with advanced ambiguity resolution technology to produce cm level accuracies without the need for local reference stations. It achieves this through a global deployment of highly redundant monitoring stations that are connected through the internet and are used to determine the precise satellite data with maximum accuracy, robustness, continuity and reliability, along with advance algorithms and receiver and antenna calibrations. This paper presents a new post-processed realization of the Trimble Centerpoint RTX technology integrated into the Applanix POSPac MMS GNSS-Aided Inertial software for mobile mapping. Real-world results from over 100 airborne flights evaluated against a DGNSS network reference are presented which show that the post-processed Centerpoint RTX solution agrees with

  2. Response and Monte Carlo evaluation of a reference ionization chamber for radioprotection level at calibration laboratories

    NASA Astrophysics Data System (ADS)

    Neves, Lucio P.; Vivolo, Vitor; Perini, Ana P.; Caldas, Linda V. E.

    2015-07-01

    A special parallel plate ionization chamber, inserted in a slab phantom for the personal dose equivalent Hp(10) determination, was developed and characterized in this work. This ionization chamber has collecting electrodes and window made of graphite, and the walls and phantom made of PMMA. The tests comprise experimental evaluation following international standards and Monte Carlo simulations, employing the PENELOPE code to evaluate the design of this new dosimeter. The experimental tests were conducted employing the radioprotection level quality N-60 established at the IPEN, and all results were within the recommended standards.

  3. Reference levels of background radioactivity for beach sands and soils in İnebolu/Kastamonu-Turkey

    NASA Astrophysics Data System (ADS)

    Kurnaz, Aslı; Türkdoǧan, Savaş; Hançerlioǧulları, Aybaba; ćetiner, M. Atıf

    2016-03-01

    This paper presents the measurement results of environmental radioactivity levels for İnebolu district (tourist area), Kastamonu-Turkey. The radioactivity concentrations of 238U, 232Th, 40K and the fission product 137Cs in soil samples collected from 13 region surroundings of study area and in 12 beach sand samples collected from along the coast of İnebolu were determined. To evaluate the radiological hazard of the natural radioactivity, based on the measured concentrations of these radionuclides, the mean absorbed gamma dose and the annual effective dose were evaluated separately, and found to be 112.90 nGy h-1 and 138.46 µSv y-1 for soil samples and 75.19 nGy h-1 and 92.22 µSv y-1 for beach sand samples, respectively. The results show that İnebolu does not have high background.

  4. Evaluation of alanine as a reference dosimeter for therapy level dose comparisons in megavoltage electron beams

    NASA Astrophysics Data System (ADS)

    McEwen, Malcolm; Sharpe, Peter; Vörös, Sándor

    2015-04-01

    When comparing absorbed dose standards from different laboratories (e.g. National Measurement Institutes, NMIs, for Key or Supplementary comparisons) it is rarely possible to carry out a direct comparison of primary standard instruments, and therefore some form of transfer detector is required. Historically, air-filled, unsealed ionization chambers have been used because of the long history of using these instruments, very good stability over many years, and ease of transport. However, the use of ion chambers for therapy-level comparisons is not without its problems. Findings from recent investigations suggest that ion chambers are prone to non-random variations, they are not completely robust to standard courier practices, and failure at any step in a comparison can render all measurements potentially useless. An alternative approach is to identify a transfer system that is insensitive to some of these concerns—effectively a dosimeter that is inexpensive, simple to use, robust, but with sufficient precision and of a size relevant to the disseminated quantity in question. The alanine dosimetry system has been successfully used in a number of situations as an audit dosimeter and therefore the purpose of this investigation was to determine whether alanine could also be used as the transfer detector for dosimetric comparisons, which require a lower value for the measurement uncertainty. A measurement protocol was developed for comparing primary standards of absorbed dose to water in high-energy electron beams using alanine pellets irradiated in a water-equivalent plastic phantom. A trial comparison has been carried out between three NMIs and has indicated that alanine is a suitable alternative to ion chambers, with the system used achieving a precision of 0.1%. Although the focus of the evaluation was on the performance of the dosimeter, the comparison results are encouraging, showing agreement at the level of the combined uncertainties (~0.6%). Based on this

  5. Children’s level of word knowledge predicts their exclusion of familiar objects as referents of novel words

    PubMed Central

    Grassmann, Susanne; Schulze, Cornelia; Tomasello, Michael

    2015-01-01

    When children are learning a novel object label, they tend to exclude as possible referents familiar objects for which they already have a name. In the current study, we wanted to know if children would behave in this same way regardless of how well they knew the name of potential referent objects, specifically, whether they could only comprehend it or they could both comprehend and produce it. Sixty-six monolingual German-speaking 2-, 3-, and 4-year-old children participated in two experimental sessions. In one session the familiar objects were chosen such that their labels were in the children’s productive vocabularies, and in the other session the familiar objects were chosen such that their labels were only in the children’s receptive vocabularies. Results indicated that children at all three ages were more likely to exclude a familiar object as the potential referent of the novel word if they could comprehend and produce its name rather than comprehend its name only. Indeed, level of word knowledge as operationalized in this way was a better predictor than was age. These results are discussed in the context of current theories of word learning by exclusion. PMID:26322005

  6. Rising Level of Public Exposure to Mobile Phones: Accumulation through Additivity and Reflectivity

    NASA Astrophysics Data System (ADS)

    Hondou, Tsuyoshi

    2002-02-01

    A dramatic development occurring in our daily life is the increasing use of mobile equipment including mobile phones and wireless access to the Internet. They enable us to access several types of information more easily than in the past. Simultaneously, the density of mobile users is rapidly increasing. When hundreds of mobile phones emit radiation, their total power is found to be comparable to that of a microwave oven or a satellite broadcasting station. Thus, the question arises: what is the public exposure level in an area with many sources of electromagnetic wave emission? We show that this level can reach the reference level for general public exposure (ICNIRP Guideline) in daily life. This is caused by the fundamental properties of electromagnetic field, namely, reflection and additivity. The level of exposure is found to be much higher than that estimated by the conventional framework of analysis that assumes that the level rapidly decreases with the inverse square distance between the source and the affected person. A simple formula for the exposure level is derived by applying energetics to the electromagnetic field. The formula reveals a potential risk of intensive exposure.

  7. Determination of Tetanus Antibody Levels in Trauma Patients Referred To Shahid Beheshti Hospital in Kashan, Iran, 2014

    PubMed Central

    Afzali, Hasan; Sharif, Mohammad Reza; Mousavi, Shamsaddin

    2015-01-01

    Background: There is a noticeable difference in serologic immune status against tetanus among different age and social groups in various countries due to different national vaccination policies and methods. Objectives: Considering that the immunization status of trauma patients against tetanus is not-known or uncertain and they may need to receive the vaccine and tetabulin, this study was conducted to determine the tetanus antibody levels in patients referred to the trauma emergency ward of Shahid Beheshti Hospital in Kashan City, Iran. Patients and Methods: This cross-sectional study was performed on 204 trauma patients referred to the trauma emergency ward of Shahid Beheshti hospital in Kashan City, Iran, in 2014. After obtaining a written informed consent from the patients, a questionnaire consisted of demographic information and tetanus vaccination record was completed by the patients. Afterwards, a 4 - 5 mL venous blood sample was taken from each patient and the tetanus antibody level (IgG) was measured using the enzyme-linked immunosorbent assay method. The tetanus antibody levels equal or more than 0.1 IU/mL were considered protective. Data were analyzed using chi-square test, independent t-test and one-way ANOVA with SPSS software version 16. Results: From a total of 204 patients, 35 cases (16.7%) were females and 169 (83.2%) were males with the mean age of 40.9 ± 3.7 years. There was no statistically significant difference in the tetanus antibody levels between both sexes (P = 0.09). Moreover, there was no significant difference in immunization status between the patients who had a history of tetanus vaccination and those who had not received the vaccine before (P = 0.67). The antibody levels were significantly reduced with the passage of time since the last vaccination (P < 0.001). Also, 87.3% of the patients had the high protective level of immunity to tetanus. Conclusions: The findings of the present study show a high level of tetanus antibody among

  8. Reference ranges for urinary levels of testosterone and epitestosterone, which may reveal gonadal function, in a Korean male population.

    PubMed

    Moon, Ju-Yeon; Kwon, Woonyong; Suh, Sungill; Cheong, Jae Chul; In, Moon Kyo; Chung, Bong Chul; Kim, Jin Young; Choi, Man Ho

    2014-03-01

    Cannabis, or marijuana, the most commonly used illicit drug in the world, has been shown to be responsible for suppressing the production and secretion of androgens, particularly testosterone. However, despite such findings in animals, the chronic effects of marijuana use on human endocrine systems have proved to be inconsistent. Here, we investigated the reference ranges of urinary levels of testosterone (T) and epitestosterone (E) as well as their metabolic ratio of T/E in a Korean male population (n=337), which would enable an evaluation of abnormal changes in steroid metabolism induced by habitually administered cannabis. The T/E ratio was significantly decreased in the marijuana group (n=18), while the urinary testosterone concentrations were also tended to decrease. This study is the first to provide data for the reference values of two urinary androgens and T/E values among control Korean males, and, furthermore, suggests that the T/E ratio, though not testosterone levels, might be used to understand the suppression of human male gonadal function affected by smoking marijuana. PMID:24333796

  9. Analyzing the level of knowledge and attitude of the mothers referring the urban health centers of Birjand about nutritional behaviors

    PubMed Central

    Rezaei, Omolbanin Motamed; Moodi, Mitra; Moazam, Nahid

    2014-01-01

    Background: Achieving a balanced and proper nutrition is one of the most important health objectives in the early years of the child's life. The aim of this study is to determine the level of knowledge and attitude of the mothers covered by the urban health centers of Birjand about nutritional behaviors. Materials and Methods: This descriptive-analytical study was conducted on the mothers with children less than five years referring the health centers of Birjand, in 1387. A questionnaire was prepared for data collection. Data were analyzed using SPSS software, Chi square, ANOVA, Tukey's post hoc and Pearson correlation coefficient statistical tests with a accuracy level of P < 0.05. Results: Two hundred ninety four patients were studied. A meaningful difference was observed between the knowledge and attitude scores in terms of the mothers’ education stand (P = 0.002). Eighty three point seven percent, 65.6%, 82.7% and 64.6% of mothers were aware about the importance of iron absorption, the onset of iron supplement drop, the minerals and vitamins in the body, and the effects of vitamin A deficiency, respectively. The mothers’ knowledge and attitude about the nutritional behavior was evaluated at the average and good level, respectively. Conclusions: Considering the average level of the mothers’ knowledge and attitude about children's nutritional behaviors, the retraining of family physicians and health centers staff about the importance of nutritional behaviors is recommended. PMID:25013830

  10. Perturbational treatment of spin-orbit coupling for generally applicable high-level multi-reference methods

    SciTech Connect

    Mai, Sebastian; Marquetand, Philipp; González, Leticia; Müller, Thomas; Plasser, Felix; Lischka, Hans

    2014-08-21

    An efficient perturbational treatment of spin-orbit coupling within the framework of high-level multi-reference techniques has been implemented in the most recent version of the COLUMBUS quantum chemistry package, extending the existing fully variational two-component (2c) multi-reference configuration interaction singles and doubles (MRCISD) method. The proposed scheme follows related implementations of quasi-degenerate perturbation theory (QDPT) model space techniques. Our model space is built either from uncontracted, large-scale scalar relativistic MRCISD wavefunctions or based on the scalar-relativistic solutions of the linear-response-theory-based multi-configurational averaged quadratic coupled cluster method (LRT-MRAQCC). The latter approach allows for a consistent, approximatively size-consistent and size-extensive treatment of spin-orbit coupling. The approach is described in detail and compared to a number of related techniques. The inherent accuracy of the QDPT approach is validated by comparing cuts of the potential energy surfaces of acrolein and its S, Se, and Te analoga with the corresponding data obtained from matching fully variational spin-orbit MRCISD calculations. The conceptual availability of approximate analytic gradients with respect to geometrical displacements is an attractive feature of the 2c-QDPT-MRCISD and 2c-QDPT-LRT-MRAQCC methods for structure optimization and ab inito molecular dynamics simulations.

  11. Overview of European concepts for high-level waste and spent fuel disposal with special reference waste container corrosion

    NASA Astrophysics Data System (ADS)

    Bennett, D. G.; Gens, R.

    2008-09-01

    This paper provides a brief overview of current repository and engineered barrier system (EBS) designs in selected high-level waste (HLW) and spent fuel (SF) disposal concepts from European countries, with special reference to key metallic waste containers and corrosion processes. The paper discusses assessments of copper, iron and steel container corrosion behaviour under the environmental conditions expected, given likely repository host rocks and groundwaters, and comments on the significance of corrosion processes, the choice of waste container materials, and areas of research. Most of the HLW and/or SF disposal programmes in European countries are pursuing disposal options in which the primary waste container is designed, in conjunction with the surrounding EBS materials, to provide complete containment of the waste for at least the period when temperatures in the disposal system are significantly raised by radioactive decay.

  12. Development of Diagnostic Reference Levels Using a Real-Time Radiation Dose Monitoring System at a Cardiovascular Center in Korea.

    PubMed

    Kim, Jungsu; Seo, Deoknam; Choi, Inseok; Nam, Sora; Yoon, Yongsu; Kim, Hyunji; Her, Jae; Han, Seonggyu; Kwon, Soonmu; Park, Hunsik; Yang, Dongheon; Kim, Jungmin

    2015-12-01

    Digital cardiovascular angiography accounts for a major portion of the radiation dose among the examinations performed at cardiovascular centres. However, dose-related information is neither monitored nor recorded systemically. This report concerns the construction of a radiation dose monitoring system based on digital imaging and communications in medicine (DICOM) data and its use at the cardiovascular centre of the University Hospitals in Korea. The dose information was analysed according to DICOM standards for a series of procedures, and the formulation of diagnostic reference levels (DRLs) at our cardiovascular centre represents the first of its kind in Korea. We determined a dose area product (DAP) DRL for coronary angiography of 75.6 Gy cm(2) and a fluoroscopic time DRL of 318.0 s. The DAP DRL for percutaneous transluminal coronary intervention was 213.3 Gy cm(2), and the DRL for fluoroscopic time was 1207.5 s. PMID:25700616

  13. Carcinogenesis and low-level ionizing radiation with special reference to lung cancer and exposure to radon daughters

    SciTech Connect

    Fabrikant, J.I.

    1982-04-01

    Of the important health effects of ionizing radiation, three important late effects - carcinogenesis, teratogenesis and mutagenesis are of greatest concern. This is because any exposure, even at low levels, carries some risk of such deleterious effects. As the dose of radiation increases above very low levels, the risk of health effects increases. Cancer-induction is the most important late somatic effect of low-dose ionizing radiation. Solid cancers, rather than leukemia, are principal late effects in exposed individuals. Tissues vary greatly in their susceptibility to radiation carcinogenesis. The most frequently occurring radiation-induced cancers in man include, in decreasing order of susceptibility: the female breast, the thyroid gland, the blood-forming tissues, the lung, certain organs of the gastrointestinal tract, and the bones. A number of biological and physical factors affect the cancer risk, such as age, sex, life-style, LET, and RBE. Despite uncertainty about low-level radiation risks, regulatory and advisory bodies must set standards for exposure, and individuals need information to be able to make informed judgments for themselves. From the point of view of the policy maker, the overriding concern is the fact that small doses of radiation can cause people to have more cancers than would otherwise be expected. While concern for all radiation effects exists, our human experience is limited to cancer-induction in exposed populations. This discussion is limited to cancer risk estimation and decision-making in relation to the health effects on populations of exposure to low levels of ionizing radiation. Here, low-level radiation will refer to yearly whole-body doses up to 5 rems or 0.05 Sv, or to cumulative doses up to 50 rems or 0.5 Sv from low-LET radiation and from high-LET radiation. (ERB)

  14. Sensitivity of ecological soil-screening levels for metals to exposure model parameterization and toxicity reference values

    PubMed Central

    Sample, Bradley E; Fairbrother, Anne; Kaiser, Ashley; Law, Sheryl; Adams, Bill

    2014-01-01

    Ecological soil-screening levels (Eco-SSLs) were developed by the United States Environmental Protection Agency (USEPA) for the purposes of setting conservative soil screening values that can be used to eliminate the need for further ecological assessment for specific analytes at a given site. Ecological soil-screening levels for wildlife represent a simplified dietary exposure model solved in terms of soil concentrations to produce exposure equal to a no-observed-adverse-effect toxicity reference value (TRV). Sensitivity analyses were performed for 6 avian and mammalian model species, and 16 metals/metalloids for which Eco-SSLs have been developed. The relative influence of model parameters was expressed as the absolute value of the range of variation observed in the resulting soil concentration when exposure is equal to the TRV. Rank analysis of variance was used to identify parameters with greatest influence on model output. For both birds and mammals, soil ingestion displayed the broadest overall range (variability), although TRVs consistently had the greatest influence on calculated soil concentrations; bioavailability in food was consistently the least influential parameter, although an important site-specific variable. Relative importance of parameters differed by trophic group. Soil ingestion ranked 2nd for carnivores and herbivores, but was 4th for invertivores. Different patterns were exhibited, depending on which parameter, trophic group, and analyte combination was considered. The approach for TRV selection was also examined in detail, with Cu as the representative analyte. The underlying assumption that generic body-weight–normalized TRVs can be used to derive protective levels for any species is not supported by the data. Whereas the use of site-, species-, and analyte-specific exposure parameters is recommended to reduce variation in exposure estimates (soil protection level), improvement of TRVs is more problematic. Environ Toxicol Chem 2014

  15. Technology, Safety and Costs of Decommissioning a Reference Low-Level Waste Burial Ground Environmental Surveillance Programs

    SciTech Connect

    Denham, D. H.; Eddy, P. A.; Hawley, K. A.; Jaquish, R. E.; Corley, J. P.

    1981-07-01

    This Addendum supplements, and to some extent replaces, the preliminary description of environmental radiological surveillance programs for low-level waste burial grounds (LLWBG) used in the parent document, 11 Technology, Safety and Costs of DecolliTlissioning a Reference Low-Level Waste Burial Ground, 11 NUREG/ CR-0570. The Addendum provides additional detail and rationale for the environmental radiological surveillance programs for the two referenced sites and inventories described in NUREG/CR-0570. The rationale and performance criteria herein are expected to be useful in providing guidance for determining the acceptability of environmental surveillance programs for other inventories and other LLWBG sites. Two generic burial grounds, one located on an arid western site and the other located on a humid eastern site, are reference facilities considered in this Addendum, and as described in the parent document (NUREG/CR-0570). The two sites are assumed to have the same capacity for waste, the same radioactive waste inventory, and similar trench characteristics and operating procedures. The climate, geology, and hydrology of the two reference sites are typical of existing western and eastern sites, altnough a single population distribution was chosen for both. Each reference burial ground occupies about 70 hectares and includes 180 trenches filled with a total of 1.5 x 10{sup 6} m{sup 3} of radioactive waste. In acldition, there are 10 slit trenches containing about 1.5 x 10{sup 3} m{sup 3} of high beta-gamma activity waste. In this Addendum environmental surveillance programs are described for the several periods in the life of a LLWBG: preoperational (prior to nuclear waste receipt); operational (including interim trench closures); post-operational (after all nuclear waste is received), for both short-term {up to three years) and long-term (up to 100 years) storage and custodial care; and decommissioning (only for the special case of waste removal). The specific

  16. Reference levels for corticosterone and immune function in farmed saltwater crocodiles (Crocodylus porosus) hatchlings using current Code of Practice guidelines.

    PubMed

    Finger, John W; Thomson, Peter C; Adams, Amanda L; Benedict, Suresh; Moran, Christopher; Isberg, Sally R

    2015-02-01

    To determine reference levels for on-farm stressors on immune responsiveness and growth rate, 253 hatchling crocodiles from 11 known breeding pairs were repeatedly measured and blood sampled during their first year. Plasma corticosterone (CORT) was used to quantify baseline stress levels in captive animals and were found to be lower (mean 1.83±SE 0.16 ng/mL) than previously reported in saltwater crocodile hatchlings. Two tests of immune function were also conducted. Innate constitutive immunity was assessed using bacterial killing assays (BKA) against two bacterial species: Escherichia coli and Providencia rettgeri, whereby the latter causes considerable economic loss to industry from septicaemic mortalities. Although the bactericidal capabilities were different at approximately 4 months old (32±3% for E. coli and 16±4% for P. rettgeri), the differences had disappeared by approximately 9 months old (58±2% and 68±6%, respectively). To assess immune responsiveness to a novel antigen, the inflammatory swelling response caused by phytohaemagglutinin (PHA) injection was assessed but was only significantly different between Samplings 1 and 3 (5% LSD). There were no significant clutch effects for CORT or PHA but there were for both BKA traits. CORT was not significantly associated with growth (head length) or the immune parameters except for P. rettgeri BKA where higher CORT levels were associated with better bactericidal capability. As such, these results suggest that the crocodiles in this study are not stressed, therefore endorsing the management strategies adopted within the Australian industry Code of Practice. PMID:25644211

  17. On the determination of reference levels for quality assurance of flattening filter free photon beams in radiation therapy

    SciTech Connect

    Clivio, Alessandro; Belosi, Maria Francesca; Cozzi, Luca; Nicolini, Giorgia; Vanetti, Eugenio; Fogliata, Antonella; Bolard, Grégory; Fenoglietto, Pascal; Krauss, Harald

    2014-02-15

    Purpose: New definitions for some dosimetric parameters for use in quality assurance of flattening filter free (FFF) beams generated by medical linear accelerators have been suggested. The present study aims to validate these suggestions and to propose possible reference levels. Methods: The main characteristics of FFF photon beams were described in terms of: field size, penumbra, unflatness, slope, and peak-position parameters. Data were collected for 6 and 10 MV-FFF beams from three different Varian TrueBeam Linacs. Measurements were performed with a 2D-array (Starcheck system from PTW-Freiburg) and with the portal dosimetry method GLAaS utilizing the build-in portal imager of TrueBeam. Data were also compared to ion chamber measurements. A cross check validation has been performed on a FFF beam of 6 MV generated by a Varian Clinac-iX upgraded to FFF capability. Results : All the parameters suggested to characterize the FFF beams resulted easily measurable and little variation was observed among different Linacs. Referring to two reference field sizes of 10 × 10 and 20 × 20 cm{sup 2}, at SDD = 100 cm and d = dmax, from the portal dosimetry data, the following results (averaging X and Y profiles) were obtained. Field size: 9.95 ± 0.02 and 19.98 ± 0.03 cm for 6 MV-FFF (9.94 ± 0.02 and 19.98 ± 0.03 cm for 10 MV-FFF). Penumbra: 2.7 ± 0.3 and 2.9 ± 0.3 mm for 6 MV-FFF (3.1 ± 0.2 and 3.3 ± 0.3 for 10 MV-FFF). Unflatness: 1.11 ± 0.01 and 1.25 ± 0.01 for 6 MV-FFF (1.21 ± 0.01 and 1.50 ± 0.01 for 10 MV-FFF). Slope: 0.320 ± 0.020%/mm and 0.43 ± 0.015%/mm for 6 MV-FFF (0.657 ± 0.023%/mm and 0.795 ± 0.017%/mm for 10 MV-FFF). Peak Position −0.2 ± 0.2 and −0.4 ± 0.2 mm for 6 MV-FFF (−0.3 ± 0.2 and 0.7 ± 0.3 mm for 10 MV-FFF). Results would depend upon measurement depth. With thresholds set to at least 95% confidence level from the measured data and to account for possible variations between detectors and methods and experimental settings, a

  18. Evidence of dose saving in routine CT practice using iterative reconstruction derived from a national diagnostic reference level survey

    PubMed Central

    Hayton, A; Beveridge, T; Marks, P; Wallace, A

    2015-01-01

    Objective: To assess the influence and significance of the use of iterative reconstruction (IR) algorithms on patient dose in CT in Australia. Methods: We examined survey data submitted to the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) National Diagnostic Reference Level Service (NDRLS) during 2013 and 2014. We compared median survey dose metrics with categorization by scan region and use of IR. Results: The use of IR results in a reduction in volume CT dose index of between 17% and 44% and a reduction in dose–length product of between 14% and 34% depending on the specific scan region. The reduction was highly significant (p < 0.001, Wilcoxon rank-sum test) for all six scan regions included in the NDRLS. Overall, 69% (806/1167) of surveys included in the analysis used IR. Conclusion: The use of IR in CT is achieving dose savings of 20–30% in routine practice in Australia. IR appears to be widely used by participants in the ARPANSA NDRLS with approximately 70% of surveys submitted employing this technique. Advances in knowledge: This study examines the impact of the use of IR on patient dose in CT on a national scale. PMID:26133224

  19. Relationships Between Spiritual Quotient and Marital Satisfaction Level of Men, Women and Couples Referred to Consultancy Centers of Bandar Abbas

    PubMed Central

    Zarei, Eghbal; Ahmadisarkhooni, Tahereh

    2013-01-01

    Objective: The aim of this research is to determine the relationship between Spiritual Quotient parameters including understanding, life origin, and spiritual life and marital satisfaction of couples in Bandar Abbas City. Methods: It is descriptive correlational study. 150 couples referred to consultancy centers of Bandar Abbas City were selected by accessible sampling method. We utilized Spiritual Quotient Questionnaire and Marriage Satisfaction Questionnaire (ENRICH) which both have high reliability and validity levels. We calculated men, women and couples’ scores in the questionnaires. Results: According to the findings; among all parameters of Spiritual Quotient, spiritual life had the strongest correlation with spiritual quotient (r=0.282 and r=0.277 for men and women; P<0.01 for both). Meanwhile, there were not any significant relationship between couples’ understanding and origin of life and their marital satisfaction. Conclusion: Overall, we can conclude that training according to cultural conditions as well as promoting couples’ spiritual quotient can be utilized to improve the quality of marital life of couples.–More studies should be conducted for further evaluation of the relationship between SQ and marital satisfaction. The results can be used for helping couples in increasing their marital satisfaction. Declaration of interest: None PMID:24644499

  20. Reference levels in the context of Fukushima - lessons learned and a challenge for the radiation protection system.

    PubMed

    Sakai, K

    2012-01-01

    A number of dose criteria were set after the accident in Fukushima, including a criterion regarding the use of school playgrounds in Fukushima. Considering the band of 1-20 mSv/year recommended by the International Commission on Radiological Protection (ICRP) for public exposure under existing exposure situations, Japanese authorities set 20 mSv/year as a 'start line' for reducing the dose to school children. However, this led to considerable confusion among the general public and some experts. They thought that the dose limit was increased to 20 mSv/year (20 times as high as before), and that school children could be exposed to 20 mSv in 1 year. This is just an example of confusion caused by inadequate comprehension of radiation effects, misunderstanding of radiation protection concepts, or both. Another issue was raised regarding the higher radiosensitivity of children compared with adults. In the 2007 ICRP Recommendations, a higher risk coefficient is given to the whole population than the adult population, because the whole population includes children; a subpopulation with higher radiosensitivity and a longer life span. The point of argument was whether a lower reference level should be set for children alone. Radiation protection experts should continue to collect scientific information to improve the radiation protection system. In addition, it is the role of these experts to explain the framework of radiation protection to the general public in plain language. PMID:23089027

  1. Local patient dose diagnostic reference levels in pediatric interventional cardiology in Chile using age bands and patient weight values

    SciTech Connect

    Ubeda, Carlos; Miranda, Patricia; Vano, Eliseo

    2015-02-15

    Purpose: To present the results of a patient dose evaluation program in pediatric cardiology and propose local diagnostic reference levels (DRLs) for different types of procedure and age range, in addition to suggesting approaches to correlate patient dose values with patient weight. This study was the first conducted in Latin America for pediatric interventional cardiology under the auspices of the International Atomic Energy Agency. Methods: Over three years, the following data regarding demographic and patient dose values were collected: age, gender, weight, height, number of cine series, total number of cine frames, fluoroscopy time (FT), and two dosimetric quantities, dose-area product (DAP) and cumulative dose (CD), at the patient entrance reference point. The third quartile values for FT, DAP, CD, number of cine series, and the DAP/body weight ratio were proposed as the set of quantities to use as local DRLs. Results: Five hundred and seventeen patients were divided into four age groups. Sample sizes by age group were 120 for <1 yr; 213 for 1 to <5 yr; 82 for 5 to <10 yr; and 102 for 10 to <16 yr. The third quartile values obtained for DAP by diagnostic and therapeutic procedures and age range were 1.17 and 1.11 Gy cm{sup 2} for <1 yr; 1.74 and 1.90 Gy cm{sup 2} for 1 to <5 yr; 2.83 and 3.22 Gy cm{sup 2} for 5 to <10 yr; and 7.34 and 8.68 Gy cm{sup 2} for 10 to <16 yr, respectively. The third quartile value obtained for the DAP/body weight ratio for the full sample of procedures was 0.17 (Gy cm{sup 2}/kg) for diagnostic and therapeutic procedures. Conclusions: The data presented in this paper are an initial attempt at establishing local DRLs in pediatric interventional cardiology, from a large sample of procedures for the standard age bands used in Europe, complemented with the values of the ratio between DAP and patient weight. This permits a rough estimate of DRLs for different patient weights and the refining of these values for the age bands when there

  2. Development of a Provisional Domain Model for the Nursing Process for Use within the Health Level 7 Reference Information Model

    PubMed Central

    Goossen, William T.F.; Ozbolt, Judy G.; Coenen, Amy; Park, Hyeoun-Ae; Mead, Charles; Ehnfors, Margareta; Marin, Heimar F.

    2004-01-01

    Objective: Since 1999, the Nursing Terminology Summits have promoted the development, evaluation, and use of reference terminology for nursing and its integration into comprehensive health care data standards. The use of such standards to represent nursing knowledge, terminology, processes, and information in electronic health records will enhance continuity of care, decision support, and the exchange of comparable patient information. As part of this activity, working groups at the 2001, 2002, and 2003 Summit Conferences examined how to represent nursing information in the Health Level 7 (HL7) Reference Information Model (RIM). Design: The working groups represented the nursing process as a dynamic sequence of phases, each containing information specific to the activities of the phase. They used Universal Modeling Language (UML) to represent this domain knowledge in models. An Activity Diagram was used to create a dynamic model of the nursing process. After creating a structural model of the information used at each stage of the nursing process, the working groups mapped that information to the HL7 RIM. They used a hierarchical structure for the organization of nursing knowledge as the basis for a hierarchical model for “Findings about the patient.” The modeling and mapping reported here were exploratory and preliminary, not exhaustive or definitive. The intent was to evaluate the feasibility of representing some types of nursing information consistently with HL7 standards. Measurements: The working groups conducted a small-scale validation by testing examples of nursing terminology against the HL7 RIM class “Observation.” Results: It was feasible to map patient information from the proposed models to the RIM class “Observation.” Examples illustrate the models and the mapping of nursing terminology to the HL7 RIM. Conclusion: It is possible to model and map nursing information into the comprehensive health care information model, the HL7 RIM. These

  3. Characteristics of the Remote Sensing Data Used in the Proposed Unfccc REDD+ Forest Reference Emission Levels (frels)

    NASA Astrophysics Data System (ADS)

    Johnson, B. A.; Scheyvens, H.; Samejima, H.; Onoda, M.

    2016-06-01

    Developing countries must submit forest reference emission levels (FRELs) to the UNFCCC to receive incentives for REDD+ activities (e.g. reducing emissions from deforestation/forest degradation, sustainable management of forests, forest carbon stock conservation/enhancement). These FRELs are generated based on historical CO2 emissions in the land use, land use change, and forestry sector, and are derived using remote sensing (RS) data and in-situ forest carbon measurements. Since the quality of the historical emissions estimates is affected by the quality and quantity of the RS data used, in this study we calculated five metrics (i-v below) to assess the quality and quantity of the data that has been used thus far. Countries could focus on improving on one or more of these metrics for the submission of future FRELs. Some of our main findings were: (i) the median percentage of each country mapped was 100%, (ii) the median historical timeframe for which RS data was used was 11.5 years, (iii) the median interval of forest map updates was 4.5 years, (iv) the median spatial resolution of the RS data was 30m, and (v) the median number of REDD+ activities that RS data was used for operational monitoring of was 1 (typically deforestation). Many new sources of RS data have become available in recent years, so complementary or alternative RS data sets for generating future FRELs can potentially be identified based on our findings; e.g. alternative RS data sets could be considered if they have similar or higher quality/quantity than the currently-used data sets.

  4. Development of a chronic noncancer oral reference dose and drinking water screening level for sulfolane using benchmark dose modeling.

    PubMed

    Thompson, Chad M; Gaylor, David W; Tachovsky, J Andrew; Perry, Camarie; Carakostas, Michael C; Haws, Laurie C

    2013-12-01

    Sulfolane is a widely used industrial solvent that is often used for gas treatment (sour gas sweetening; hydrogen sulfide removal from shale and coal processes, etc.), and in the manufacture of polymers and electronics, and may be found in pharmaceuticals as a residual solvent used in the manufacturing processes. Sulfolane is considered a high production volume chemical with worldwide production around 18 000-36 000 tons per year. Given that sulfolane has been detected as a contaminant in groundwater, an important potential route of exposure is tap water ingestion. Because there are currently no federal drinking water standards for sulfolane in the USA, we developed a noncancer oral reference dose (RfD) based on benchmark dose modeling, as well as a tap water screening value that is protective of ingestion. Review of the available literature suggests that sulfolane is not likely to be mutagenic, clastogenic or carcinogenic, or pose reproductive or developmental health risks except perhaps at very high exposure concentrations. RfD values derived using benchmark dose modeling were 0.01-0.04 mg kg(-1) per day, although modeling of developmental endpoints resulted in higher values, approximately 0.4 mg kg(-1) per day. The lowest, most conservative, RfD of 0.01 mg kg(-1) per day was based on reduced white blood cell counts in female rats. This RfD was used to develop a tap water screening level that is protective of ingestion, viz. 365 µg l(-1). It is anticipated that these values, along with the hazard identification and dose-response modeling described herein, should be informative for risk assessors and regulators interested in setting health-protective drinking water guideline values for sulfolane. PMID:22936336

  5. Pulse wave velocity as marker of preclinical arterial disease: reference levels in a uruguayan population considering wave detection algorithms, path lengths, aging, and blood pressure.

    PubMed

    Farro, Ignacio; Bia, Daniel; Zócalo, Yanina; Torrado, Juan; Farro, Federico; Florio, Lucía; Olascoaga, Alicia; Alallón, Walter; Lluberas, Ricardo; Armentano, Ricardo L

    2012-01-01

    Carotid-femoral pulse wave velocity (PWV) has emerged as the gold standard for non-invasive evaluation of aortic stiffness; absence of standardized methodologies of study and lack of normal and reference values have limited a wider clinical implementation. This work was carried out in a Uruguayan (South American) population in order to characterize normal, reference, and threshold levels of PWV considering normal age-related changes in PWV and the prevailing blood pressure level during the study. A conservative approach was used, and we excluded symptomatic subjects; subjects with history of cardiovascular (CV) disease, diabetes mellitus or renal failure; subjects with traditional CV risk factors (other than age and gender); asymptomatic subjects with atherosclerotic plaques in carotid arteries; patients taking anti-hypertensives or lipid-lowering medications. The included subjects (n = 429) were categorized according to the age decade and the blood pressure levels (at study time). All subjects represented the "reference population"; the group of subjects with optimal/normal blood pressures levels at study time represented the "normal population." Results. Normal and reference PWV levels were obtained. Differences in PWV levels and aging-associated changes were obtained. The obtained data could be used to define vascular aging and abnormal or disease-related arterial changes. PMID:22666551

  6. Pulse Wave Velocity as Marker of Preclinical Arterial Disease: Reference Levels in a Uruguayan Population Considering Wave Detection Algorithms, Path Lengths, Aging, and Blood Pressure

    PubMed Central

    Farro, Ignacio; Bia, Daniel; Zócalo, Yanina; Torrado, Juan; Farro, Federico; Florio, Lucía; Olascoaga, Alicia; Alallón, Walter; Lluberas, Ricardo; Armentano, Ricardo L.

    2012-01-01

    Carotid-femoral pulse wave velocity (PWV) has emerged as the gold standard for non-invasive evaluation of aortic stiffness; absence of standardized methodologies of study and lack of normal and reference values have limited a wider clinical implementation. This work was carried out in a Uruguayan (South American) population in order to characterize normal, reference, and threshold levels of PWV considering normal age-related changes in PWV and the prevailing blood pressure level during the study. A conservative approach was used, and we excluded symptomatic subjects; subjects with history of cardiovascular (CV) disease, diabetes mellitus or renal failure; subjects with traditional CV risk factors (other than age and gender); asymptomatic subjects with atherosclerotic plaques in carotid arteries; patients taking anti-hypertensives or lipid-lowering medications. The included subjects (n = 429) were categorized according to the age decade and the blood pressure levels (at study time). All subjects represented the “reference population”; the group of subjects with optimal/normal blood pressures levels at study time represented the “normal population.” Results. Normal and reference PWV levels were obtained. Differences in PWV levels and aging-associated changes were obtained. The obtained data could be used to define vascular aging and abnormal or disease-related arterial changes. PMID:22666551

  7. Fabrication and qualification of roughness reference samples for industrial testing of surface roughness levels below 0.5 nm Sq

    NASA Astrophysics Data System (ADS)

    Faehnle, O.; Langenbach, E.; Zygalsky, F.; Frost, F.; Fechner, R.; Schindler, A.; Cumme, M.; Biskup, H.; Wünsche, C.; Rascher, R.

    2015-08-01

    Applying reactive ion beam etching (RIBE) processes at the Leibniz Institute of Surface Modification (IOM), several reference samples to be used in industry for calibrating of roughness testing equipment have been generated with the smoothest sample featuring 0.1 nm rms Sq. Subsequently these reference samples have been measured cross-site applying atomic force microscopy (AFM), white light interferometry (WLI), Nomarski1 microscopy (NM) and scatterometry (iTIRM2) determining the appropriate range of measurable rms surface roughness for each industrial measuring device.

  8. Age- and Gender-Specific Reference Intervals for Fasting Blood Glucose and Lipid Levels in School Children Measured With Abbott Architect c8000 Chemistry Analyzer.

    PubMed

    Tamimi, Waleed; Albanyan, Esam; Altwaijri, Yasmin; Tamim, Hani; Alhussein, Fahad

    2012-04-01

    Reference intervals for pubertal characteristics are influenced by genetic, geographic, dietary and socioeconomic factors. Therefore, the aim of this study was to establish age-specific reference intervals of glucose and lipid levels among local school children. This was cross-sectional study, conducted among Saudi school children. Fasting blood samples were collected from 2149 children, 1138 (53%) boys and 1011 (47%) girls, aged 6 to 18 years old. Samples were analyzed on the Architect c8000 Chemistry System (Abbott Diagnostics, USA) for glucose, cholesterol, triglycerides, HDL and LDL. Reference intervals were established by nonparametric methods between the 2.5th and 97.5th percentiles. Significant differences were observed between boys and girls for cholesterol and triglycerides levels in all age groups (P < 0.02). Only at age 6-7 years and at adolescents, HDL and LDL levels were found to be significant (P < 0.001). No significant differences were seen in glucose levels except at age 12 to 13 years. Saudi children have comparable serum cholesterol levels than their Western counterparts. This may reflect changing dietary habits and increasing affluence in Saudi Arabia. Increased lipid screening is anticipated, and these reference intervals will aid in the early assessment of cardiovascular and diabetes risk in Saudi pediatric populations. PMID:23542765

  9. Reference values of cadmium, arsenic and manganese in blood and factors associated with exposure levels among adult population of Rio Branco, Acre, Brazil.

    PubMed

    Freire, Carmen; Koifman, Rosalina Jorge; Fujimoto, Denys; de Oliveira Souza, Vanessa Cristina; Barbosa, Fernando; Koifman, Sergio

    2015-06-01

    This study aimed to investigate the distribution and factors influencing blood levels of Cadmium (Cd), Arsenic (As), and Manganese (Mn), and to determine their reference values in a sample of blood donors residing in Rio Branco, capital city of Acre State, Brazil. Blood samples were collected from all blood donors attending the Central Hemotherapic Unit in Rio Branco between 2010 and 2011. Among these, 1183 donors (98.9%) answered to a questionnaire on sociodemographic and lifestyle factors. Blood metal concentrations were determined by atomic spectrometry. Association between Cd, As and Mn levels and donors' characteristics was examined by linear regression analysis. Reference values were estimated as the upper limit of the 95% confidence interval of the 95th percentile of metal levels. References values were 0.87 μg L(-1) for Cd, 9.87 μg L(-1) for As, and 29.32 μg L(-1) for Mn. Reference values of Cd and As in smokers were 2.66 and 10.86 μg L(-1), respectively. Factors contributing to increase Cd levels were smoking, ethnicity (non-white), and lower education, whereas drinking tea and non-bottled water were associated with lower Cd. Lower levels of As were associated with higher household income, living near industrial facilities, working in a glass factory, a compost plant or in metal mining activities. Risk factors for Mn exposure were not identified. In general, blood Cd concentrations were in the range of exposure levels reported for other people from the general population, whereas levels of As and Mn were higher than in other non-occupationally exposed populations elsewhere. PMID:25655821

  10. Assessing the potential for salmon recovery via floodplain restoration: a multitrophic level comparison of dredge-mined to reference segments.

    PubMed

    Bellmore, J Ryan; Baxter, Colden V; Ray, Andrew M; Denny, Lytle; Tardy, Kurt; Galloway, Evelyn

    2012-03-01

    Pre-restoration studies typically focus on physical habitat, rather than the food-base that supports aquatic species. However, both food and habitat are necessary to support the species that habitat restoration is frequently aimed at recovering. Here we evaluate if and how the productivity of the food-base that supports fish production is impaired in a dredge-mined floodplain within the Yankee Fork Salmon River (YFSR), Idaho (USA); a site where past restoration has occurred and where more has been proposed to help recover anadromous salmonids. Utilizing an ecosystem approach, we found that the dredged segment had comparable terrestrial leaf and invertebrate inputs, aquatic primary producer biomass, and production of aquatic invertebrates relative to five reference floodplains. Thus, the food-base in the dredged segment did not necessarily appear impaired. On the other hand, we observed that off-channel aquatic habitats were frequently important to productivity in reference floodplains, and the connection of these habitats in the dredged segment via previous restoration increased invertebrate productivity by 58%. However, using a simple bioenergetic model, we estimated that the invertebrate food-base was at least 4× larger than present demand for food by fish in dredged and reference segments. In the context of salmon recovery efforts, this observation questions whether additional food-base productivity provided by further habitat restoration would be warranted in the YFSR. Together, our findings highlight the importance of studies that assess the aquatic food-base, and emphasize the need for more robust ecosystem models that evaluate factors potentially limiting fish populations that are the target of restoration. PMID:22323109

  11. Assessing the Potential for Salmon Recovery via Floodplain Restoration: A Multitrophic Level Comparison of Dredge-Mined to Reference Segments

    NASA Astrophysics Data System (ADS)

    Bellmore, J. Ryan; Baxter, Colden V.; Ray, Andrew M.; Denny, Lytle; Tardy, Kurt; Galloway, Evelyn

    2012-03-01

    Pre-restoration studies typically focus on physical habitat, rather than the food-base that supports aquatic species. However, both food and habitat are necessary to support the species that habitat restoration is frequently aimed at recovering. Here we evaluate if and how the productivity of the food-base that supports fish production is impaired in a dredge-mined floodplain within the Yankee Fork Salmon River (YFSR), Idaho (USA); a site where past restoration has occurred and where more has been proposed to help recover anadromous salmonids. Utilizing an ecosystem approach, we found that the dredged segment had comparable terrestrial leaf and invertebrate inputs, aquatic primary producer biomass, and production of aquatic invertebrates relative to five reference floodplains. Thus, the food-base in the dredged segment did not necessarily appear impaired. On the other hand, we observed that off-channel aquatic habitats were frequently important to productivity in reference floodplains, and the connection of these habitats in the dredged segment via previous restoration increased invertebrate productivity by 58%. However, using a simple bioenergetic model, we estimated that the invertebrate food-base was at least 4× larger than present demand for food by fish in dredged and reference segments. In the context of salmon recovery efforts, this observation questions whether additional food-base productivity provided by further habitat restoration would be warranted in the YFSR. Together, our findings highlight the importance of studies that assess the aquatic food-base, and emphasize the need for more robust ecosystem models that evaluate factors potentially limiting fish populations that are the target of restoration.

  12. Potential reference measurement procedures for PBDE in surface water at levels required by the EU Water Frame Directive.

    PubMed

    Swart, Claudia; Gantois, Fanny; Petrov, Panayot; Entwisle, John; Goenaga-Infante, Heidi; Nousiainen, Marjaana; Bílsel, Mine; Binici, Burcu; Gonzalez-Gago, Adriana; Pröfrock, Daniel; Gören, Ahmet C

    2016-05-15

    Polybrominated diphenylethers (PBDE), used as flame retardants, are named as priority substances in the Directive 2000/60/EC of the European parliament and of the council establishing a framework for Community action in the field of water policy. An annual average environmental quality standard (EQS) for inland surface waters of 0.0005 µg/L (0.0002 µg/L for other surface waters) for PBDE congeners involved in the technical penta-PBDE mixtures containing PBDE with five bromine atoms has been established. The directives focus especially on the congeners PBDE 28, 47, 99, 100, 153 and 154 contained in the penta-PBDE mixture. Up to now, no reference measurement procedures have been established reaching the limits of quantification (LOQs) and the associated uncertainties as defined in the directives with results traceable to the SI. Within a recent European project on metrology, different approaches for the traceable quantification of PBDE, based on liquid/liquid or solid phase extraction followed by the detection with gas chromatography coupled to either inductively coupled plasma mass spectrometry or triple quadrupole mass spectrometry, were investigated and the related LOQs and expanded uncertainties of the results were compared. A complete uncertainty budget for each method was estimated according to the Guide to the Expression of Uncertainty in Measurement (GUM). All presented analytical procedures can serve as reference measurement procedures regarding the LOQs and their associated expanded uncertainties for monitoring the six priority PBDEs named above. LOQs as low as 0.026 ng/kg with an associated expanded uncertainty of 0.002 ng/kg could be achieved. PMID:26992518

  13. Causes of creatine kinase levels greater than 1000 IU/L in patients referred to rheumatology.

    PubMed

    Leverenz, David; Zaha, Oana; Crofford, Leslie J; Chung, Cecilia P

    2016-06-01

    Patients with severely elevated creatine kinase (CK) concentrations are commonly referred to rheumatologists to evaluate for the presence of an idiopathic inflammatory myopathy (IIM). However, no studies have evaluated the frequency with which IIMs are encountered in this clinical scenario. The Vanderbilt Synthetic Derivative, a de-identified copy of over 2 million patient records, was searched to identify adult patients with a CK greater than 1000 IU/L who had been evaluated by a rheumatologist. Each patient was assigned a diagnosis using a pre-determined algorithm. The records were then reviewed for pertinent demographic data and clinical characteristics. A total of 192 patients were included for analysis. Of these patients, 105 (55 %) were diagnosed with an IIM. The non-IIM causes were drug/toxin exposure (n = 16, 8 %), infection (n = 12, 6 %), trauma (n = 10, 5 %), myocardial injury (n = 5, 3 %), hypothyroidism (n = 4, 2 %), muscular dystrophy (n = 4, 2 %), neuropsychiatric disorder (n = 3, 2 %), metabolic myopathy (n = 2, 1 %), idiopathic CK elevation (n = 11, 6 %), and other diagnoses (n = 20, 10 %). Several characteristics were found to be significantly different between IIM and non-IIM cases. In particular, patients with an IIM were more likely to be female, have a positive ANA, have interstitial lung disease, and have proximal, symmetric weakness. This study found that approximately half of patients referred to our division of rheumatology with a CK greater than 1000 IU/L were diagnosed with an IIM. Given the importance of prompt diagnosis and treatment of these disorders, rapid assessment by the consulting rheumatologist for these patients is recommended. PMID:27041384

  14. SUMMER AND WINTER VITAMIN D3 LEVELS IN FOUR LEMUR SPECIES HOUSED AT A BRITISH ZOO, WITH REFERENCE TO UVB LEVELS.

    PubMed

    Killick, Rowena; Saunders, Richard; Redrobe, Sharon P

    2015-09-01

    Serum samples were collected from 18 lemurs of four diurnal/cathemeral species housed with outdoor access at Bristol Zoo Gardens (United Kingdom) to test 25-hydroxy-vitamin D3 (25OHD3) levels as part of the veterinary department's preventative health care program. Samples were collected from each lemur in August 2008 (summer) and January 2009 (winter) to examine the effect of season on 25OHD3 levels. The lemurs were fed commercial primate food and a range of fruit and vegetables, and dietary levels of vitamin D3 remained the same throughout the study period. Statistical analysis showed that the lemurs' summer 25OHD3 values (range 26.7 to >150.0 μg/L) were significantly higher than their winter 25OHD3 values (range 11.4-87.1 μg/L). UVB measurements taken during the study period confirmed that UVB levels were significantly higher in summer (mean reading for 1200-1300 GMT time period 153.8 μW/cm2) compared to winter (mean reading for 1200-1300 GMT time period 19.4 μW/cm2). The 25OHD3 levels measured were generally found to be high compared to previously published values from wild (free-ranging) lemurs in Madagascar. The most likely explanation for this was the higher vitamin D3 content of the captive lemurs' diet, as UVB levels at the zoo (latitude 51° north) are substantially lower than those that occur in Madagascar (latitude 12°-26° south). No evidence of vitamin D toxicity or deficiency was found in any of the captive lemurs. The results indicate that vitamin D3 levels in lemurs housed with outdoor access in the United Kingdom and by extension, other regions of similar latitude, vary with seasonal environmental UVB levels, in a similar way to the seasonal variations in vitamin D3 observed in humans living in these regions, but that vitamin D levels in this captive lemur population were adequate compared to wild lemur levels, even in winter. PMID:26352953

  15. Validation of RT-qPCR reference genes and determination of Robo4 expression levels in human retinal endothelial cells under hypoxia and/or hyperglycemia.

    PubMed

    Xie, Jia'nan; Liu, Xin; Li, Ying; Liu, Yang; Su, Guanfang

    2016-07-01

    Real-time reverse transcription quantitative polymerase chain reaction (RT-qPCR) has become the most common technique to investigate mRNA expression levels of target genes. In order to obtain accurate results, stable reference genes need to be selected for normalization in an experimental study. Human retinal endothelial cells (HREC) cultured in a hypoxic and hyperglycemic environment is a potential cell model to study diabetic retinopathy (DR), but the proper reference genes for RNA analysis have not yet been determined. In the present study, we evaluated the expression levels of 14 candidate housekeeping genes and selected the most suitable reference genes for RT-qPCR for HREC under hypoxic and/or hyperglycemic conditions. The results of the analyses using GeNorm, NormFinder, and BestKeeper software showed that a combination of TBP, PUM1, and ALAS1 was most suitable for this research. Based on these results, mRNA expression levels of Roundabout4 (Robo4) in HREC were determined. The RT-qPCR analysis showed that there was a significant increase in Robo4 expression under hyperglycemic conditions, while there was a decrease in expression under hypoxic and combined hypoxic and hyperglycemic conditions, suggesting that Robo4 might play different roles in various stages of DR. PMID:27041242

  16. Relevance of biotic pathways to the long-term regulation of nuclear-waste disposal. Topical report on reference western arid low-level sites

    SciTech Connect

    McKenzie, D.H.; Cadwell, L.L.; Eberhardt, L.E.; Kennedy, W.E. Jr.; Peloquin, R.A.; Simmons, M.A.

    1982-10-01

    The purpose of the work reported here was to develop an order of magnitude estimate for the potential dose to man resulting from biotic transport mechanisms at a reference western arid low-level waste site. A description of the reference site is presented that includes the waste inventories, site characteristics and biological communities. Parameter values for biotic transport processes are based on data reported in current literature. Transport and exposure scenarios are developed for assessing biotic transport during 100 years following site closure. Calculations of radionuclide decay and waste container decomposition are made to estimate the quantities available for biotic transport. Dose to a man occupying the reference site following the 100 years of biotic transport are calculated. These dose estimates are compared to dose estimates for the intruder-agricultural scenario reported in the DEIS for 10 CFR 61 (NRC). Dose to man estimates as a result of biotic transport are estimated to be of the same order of magnitude as the dose resulting from the more commonly evaluated human intrusion scenario. The reported lack of potential importance of biotic transport at low-level waste sites in earlier assessment studies is not confirmed by the findings presented in this report. These results indicate that biotic transport has the potential to influence low-level waste site performance. Through biotic transport, radionuclides may be moved to locations where they can enter exposure pathways to man.

  17. Radiostrontium levels in foodstuffs: 4-Years control activity by Italian reference centre, as a contribution to risk assessment.

    PubMed

    Iammarino, Marco; dell'Oro, Daniela; Bortone, Nicola; Mangiacotti, Michele; Damiano, Rita; Chiaravalle, Antonio Eugenio

    2016-11-01

    (90)Sr is considered an important contaminant relating to food supply chains. In this study, 176 liquid and 260 solid foods, were analysed in order to quantify (90)Sr. Through ruggedness tests, the application field of radiochemical methods used was extended successfully to all most important types of foodstuffs. Regarding liquid matrices, milk samples resulted the most important indicator about (90)Sr contamination, with mean (90)Sr activity concentration equal to 0.058BqL(-1). Among other liquid foods, wine/spirits and livestock watering resulted the most contaminated, with mean contamination levels equal to 0.022 and 0.035BqL(-1), respectively. Concerning solid matrices, cheeses produced from sheep's milk and animal feeds resulted the most contaminated (mean levels: 1.237 and 1.557Bqkg(-1), respectively). Meat products and seafood showed contamination levels not significant within this survey; while, among vegetables, cacao/chocolate and spices resulted in contamination levels comparable with those of cheese obtained from milk of cows origin. PMID:27211657

  18. Combination of Vlbi, GPS and Slr Observations At The Observation Level For The Realization of Terrestrial and Celestial Reference Frames

    NASA Astrophysics Data System (ADS)

    Andersen, P. H.

    Forsvarets forskningsinstitutt (FFI, the Norwegian Defence Research Establishment) has during the last 17 years developed a software system called GEOSAT, for the analysis of any type of high precision space geodetic observations. A unique feature of GEOSAT is the possibility of combining any combination of different space geode- tic data at the observation level with one consistent model and one consistent strategy. This is a much better strategy than the strategy in use today where different types of observations are processed separately using analysis software developed specifically for each technique. The results from each technique are finally combined a posteriori. In practice the models implemented in the software packages differ at the 1-cm level which is almost one order of magnitude larger than the internal precision of the most precise techniques. Another advantage of the new proposed combination method is that for example VLBI and GPS can use the same tropospheric model with common parameterization. The same is the case for the Earth orientation parameters, the geo- center coordinates and other geodetic or geophysical parameters where VLBI, GPS and SLR can have a common estimate for each of the parameters. The analysis with GEOSAT is automated for the combination of VLBI, SLR and GPS observations. The data are analyzed in batches of one day where the result from each daily arc is a SRIF array (Square Root Information Filter). A large number of SRIF arrays can be combined into a multi-year solution using the CSRIFS program (Com- bination Square Root Information Filter and Smoother). Four parameter levels are available and any parameter can, at each level, either be represented as a constant or a stochastic parameter (white noise, colored noise, or random walk). The batch length (i.e. the time interval between the addition of noise to the SRIF array) can be made time- and parameter dependent. GEOSAT and CSRIFS have been applied in the analysis of selected

  19. Relevance of biotic pathways to the long-term regulation of nuclear waste disposal. Topical report on reference eastern humid low-level sites

    SciTech Connect

    McKenzie, D.H.; Cadwell, L.L.; Eberhardt, L.E.; Kennedy, W.E. Jr.; Peloquin, R.A.; Simmons, M.A.

    1983-01-01

    The purpose of the work reported here was to develop an order-of-magnitude estimate for the potential dose to man resulting from biotic transport mechanisms at a humid reference low-level waste site in the eastern US. A description of the reference site is presented that includes the waste inventories, site characteristics and biological communites. Parameter values for biotic transport processes are based on data reported in current literature. Transport and exposure scenarios are developed for assessing biotic transport during 500 years following site closure. Calculations of radionuclide decay and waste container decomposition are made to estimate the quantities available for biotic transport. Doses to man are calculated for the biological transport of radionucludes at the reference site after loss of institutional control. These dose estimates are compared to dose estimates we calculated for the intruder-agricultural scenarios reported in the DEIS for 10 CFR 61 (NRC). Dose to man estimates as a result of cumulative biotic transport are calculated to be of the same order-of-magnitude as the dose resulting from the more commonly evaluated human intrusion scenario. The reported lack of potential importance of biotic transport at low-level waste sites in earlier assessment studies is not confirmed by findings presented in this report. Through biotic transport, radionuclides can be moved to locations where they can enter exposure pathways to man.

  20. GLM Proxy Data Generation: Methods for Stroke/Pulse Level Inter-Comparison of Ground-Based Lightning Reference Networks

    NASA Technical Reports Server (NTRS)

    Cummins, Kenneth L.; Carey, Lawrence D.; Schultz, Christopher J.; Bateman, Monte G.; Cecil, Daniel J.; Rudlosky, Scott D.; Petersen, Walter Arthur; Blakeslee, Richard J.; Goodman, Steven J.

    2011-01-01

    In order to produce useful proxy data for the GOES-R Geostationary Lightning Mapper (GLM) in regions not covered by VLF lightning mapping systems, we intend to employ data produced by ground-based (regional or global) VLF/LF lightning detection networks. Before using these data in GLM Risk Reduction tasks, it is necessary to have a quantitative understanding of the performance of these networks, in terms of CG flash/stroke DE, cloud flash/pulse DE, location accuracy, and CLD/CG classification error. This information is being obtained through inter-comparison with LMAs and well-quantified VLF/LF lightning networks. One of our approaches is to compare "bulk" counting statistics on the spatial scale of convective cells, in order to both quantify relative performance and observe variations in cell-based temporal trends provided by each network. In addition, we are using microsecond-level stroke/pulse time correlation to facilitate detailed inter-comparisons at a more-fundamental level. The current development status of our ground-based inter-comparison and evaluation tools will be presented, and performance metrics will be discussed through a comparison of Vaisala s Global Lightning Dataset (GLD360) with the NLDN at locations within and outside the U.S.

  1. A review of trend models applied to sea level data with reference to the "acceleration-deceleration debate"

    NASA Astrophysics Data System (ADS)

    Visser, Hans; Dangendorf, Sönke; Petersen, Arthur C.

    2015-06-01

    Global sea levels have been rising through the past century and are projected to rise at an accelerated rate throughout the 21st century. This has motivated a number of authors to search for already existing accelerations in observations, which would be, if present, vital for coastal protection planning purposes. No scientific consensus has been reached yet as to how a possible acceleration could be separated from intrinsic climate variability in sea level records. This has led to an intensive debate on its existence and, if absent, also on the general validity of current future projections. Here we shed light on the controversial discussion from a methodological point of view. To do so, we provide a comprehensive review of trend methods used in the community so far. This resulted in an overview of 30 methods, each having its individual mathematical formulation, flexibilities, and characteristics. We illustrate that varying trend approaches may lead to contradictory acceleration-deceleration inferences. As for statistics-oriented trend methods, we argue that checks on model assumptions and model selection techniques yield a way out. However, since these selection methods all have implicit assumptions, we show that good modeling practices are of importance too. We conclude at this point that (i) several differently characterized methods should be applied and discussed simultaneously, (ii) uncertainties should be taken into account to prevent biased or wrong conclusions, and (iii) removing internally generated climate variability by incorporating atmospheric or oceanographic information helps to uncover externally forced climate change signals.

  2. Reference design of 100 MW-h lithium/iron sulfide battery system for utility load leveling

    SciTech Connect

    Zivi, S.M.; Kacinskas, H.; Pollack, I.; Chilenskas, A.A.; Barney, D.L.; Grieve, W.; McFarland, B.L.; Sudar, S.; Goldstein, E.; Adler, E.

    1980-03-01

    The first year in a two-year cooperative effort between Argonne National Laboratory and Rockwell International to develop a conceptual design of a lithium alloy/iron sulfide battery for utility load leveling is presented. A conceptual design was developed for a 100 MW-h battery system based upon a parallel-series arrangement of 2.5 kW-h capacity cells. The sales price of such a battery system was estimated to be very high, $80.25/kW-h, exclusive of the cost of the individual cells, the dc-to-ac converters, site preparation, or land acquisition costs. Consequently, the second year's efforts were directed towards developing modified designs with significantly lower potential costs.

  3. Significant RF-EMF and thermal levels observed in a computational model of a person with a tibial plate for grounded 40 MHz exposure.

    PubMed

    McIntosh, Robert L; Iskra, Steve; Anderson, Vitas

    2014-05-01

    Using numerical modeling, a worst-case scenario is considered when a person with a metallic implant is exposed to a radiofrequency (RF) electromagnetic field (EMF). An adult male standing on a conductive ground plane was exposed to a 40 MHz vertically polarized plane wave field, close to whole-body resonance where maximal induced current flows are expected in the legs. A metal plate (50-300 mm long) was attached to the tibia in the left leg. The findings from this study re-emphasize the need to ensure compliance with limb current reference levels for exposures near whole-body resonance, and not just rely on compliance with ambient electric (E) and magnetic (H) field reference levels. Moreover, we emphasize this recommendation for someone with a tibial plate, as failure to comply may result in significant tissue damage (increases in the localized temperature of 5-10 °C were suggested by the modeling for an incident E-field of 61.4 V/m root mean square (rms)). It was determined that the occupational reference level for limb current (100 mA rms), as stipulated in the 1998 guidelines of the International Commission on Non-Ionizing Radiation Protection (ICNIRP), is satisfied if the plane wave incident E-field levels are no more than 29.8 V/m rms without an implant and 23.4 V/m rms for the model with a 300 mm implant. PMID:24578303

  4. Reference ranges and cutoff levels of pneumococcal antibody global serum assays (IgG and IgG2) and specific antibodies in healthy children and adults.

    PubMed

    Rose, M A; Buess, J; Ventur, Y; Zielen, S; Herrmann, E; Schulze, J; Schubert, R

    2013-08-01

    Pneumococcal antibodies represent the acquisition of natural immunity. Determination of pneumococcal antibodies is an important screening tool for immunodeficiencies. Our study generated reference ranges and cutoff levels for pneumococcal antibody global serum assays correlated to a specific pneumococcal antibody ELISA. Specific pneumococcal antibody levels were measured from 457 children undergoing elective surgery and 46 healthy adult volunteers (88 with previous pneumococcal immunization from both groups), 22 severe immunodeficient subjects with ataxia telangiectasia (A-T, negative controls), and age-matched 36 healthy allergic asthmatics. We determined a representative panel of serotype-specific pneumococcal antibodies (serotype 4, 5, 6B, 7F, 14, 18C, 19F, 23F) by ELISA and global pneumococcal IgG and IgG2 antibodies by EIA. In vaccine-naïve healthy subjects, initial pneumococcal IgG geometric mean concentrations of 13.1 μg/ml were low in the first year of life and increased over the time, reaching adult levels (70.5 μg/ml) at age 8-12 years. In parallel, IgG2 antibodies increased from 20.7 % (0.5-1 year old) to adult proportions (>30 %) in preschoolers. Correlation between the pneumococcal IgG screening assay and specific pneumococcal antibody levels was acceptable (Pearson's coefficient r = 0.4455; p = 0.001). Cutoff levels showed high sensitivity, whereas specificity was high to moderate calculated from correlations with the specific ELISA. We provide reference ranges and cutoff levels for the interpretation of specific antibody determinations in the clinical setting. The global pneumococcal IgG/IgG2 assay is a suitable screening tool and correlates with the ELISA serotype-specific pneumococcal antibodies. However, results below our cutoff values should be re-evaluated by serotype-specific ELISA testing. PMID:23529214

  5. An energy decomposition analysis for intermolecular interactions from an absolutely localized molecular orbital reference at the coupled-cluster singles and doubles level

    SciTech Connect

    Azar, R. Julian; Head-Gordon, Martin

    2012-01-14

    We propose a wave function-based method for the decomposition of intermolecular interaction energies into chemically-intuitive components, isolating both mean-field- and explicit correlation-level contributions. We begin by solving the locally-projected self-consistent field for molecular interactions equations for a molecular complex, obtaining an intramolecularly polarized reference of self-consistently optimized, absolutely-localized molecular orbitals (ALMOs), determined with the constraint that each fragment MO be composed only of atomic basis functions belonging to its own fragment. As explicit inter-electronic correlation is integral to an accurate description of weak forces underlying intermolecular interaction potentials, namely, coordinated fluctuations in weakly interacting electronic densities, we add dynamical correlation to the ALMO polarized reference at the coupled-cluster singles and doubles level, accounting for explicit dispersion and charge-transfer effects, which map naturally onto the cluster operator. We demonstrate the stability of energy components with basis set extension, follow the hydrogen bond-breaking coordinate in the C{sub s}-symmetry water dimer, decompose the interaction energies of dispersion-bound rare gas dimers and other van der Waals complexes, and examine charge transfer-dominated donor-acceptor interactions in borane adducts. We compare our results with high-level calculations and experiment when possible.

  6. Brain-derived neurotrophic factor, acting at the spinal cord level, participates in bladder hyperactivity and referred pain during chronic bladder inflammation.

    PubMed

    Frias, B; Allen, S; Dawbarn, D; Charrua, A; Cruz, F; Cruz, C D

    2013-03-27

    Brain-derived neurotrophic factor (BDNF) is a neurotrophin (NT) known to participate in chronic somatic pain. A recent study has indicated that BDNF may participate in chronic cystitis at the peripheral level. However, the principal site of action for this NT is the central nervous system, most notably the spinal cord. The effects of centrally-acting BDNF on bladder function in normal animals and its central role during chronic cystitis are presently unknown. The present study was undertaken to clarify this issue. For that purpose, control non-inflamed animals were intrathecally injected with BDNF, after which bladder function was evaluated. This treatment caused short-lasting bladder hyperactivity; whereas chronic intrathecal administration of BDNF did not elicit this effect. Cutaneous sensitivity was assessed by mechanical allodynia as an internal control of BDNF action. To ascertain the role of BDNF in bladder inflammation, animals with cyclophosphamide-induced cystitis received intrathecal injections of either a general Trk receptor antagonist or a BDNF scavenger. Blockade of Trk receptors or BDNF sequestration notably improved bladder function. In addition, these treatments also reduced referred pain, typically observed in rats with chronic cystitis. Reduction of referred pain was accompanied by a decrease in the spinal levels of extracellular signal-regulated kinase (ERK) phosphorylation, a marker of increased sensory barrage in the lumbosacral spinal cord, and spinal BDNF expression. Results obtained here indicate that BDNF, acting at the spinal cord level, contributes to bladder hyperactivity and referred pain, important hallmarks of chronic cystitis. In addition, these data also support the development of BDNF modulators as putative therapeutic options for the treatment of chronic bladder inflammation. PMID:23313710

  7. Reach for Reference. Four Recent Reference Books

    ERIC Educational Resources Information Center

    Safford, Barbara Ripp

    2004-01-01

    This article provides descriptions of four new science and technology encyclopedias that are appropriate for inclusion in upper elementary and/or middle school reference collections. "The Macmillan Encyclopedia of Weather" (Stern, Macmillan Reference/Gale), a one-volume encyclopedia for upper elementary and middle level students, is a…

  8. A comparison of mean glandular dose diagnostic reference levels within the all-digital Irish National Breast Screening Programme and the Irish Symptomatic Breast Services.

    PubMed

    O'Leary, Desiree; Rainford, Louise

    2013-03-01

    Data on image quality, compression and radiation dose were collected from symptomatic breast units within the Republic of Ireland. Quantitative and qualitative data were analysed using SPSS. Recommendations of mean glandular dose (MGD) diagnostic reference levels were made at various levels for film-screen and full field digital mammography units to match levels published worldwide. MGDs received by symptomatic breast patients within Ireland are higher than those received in the all-digital Irish Breast Screening service; 55-65 mm breast: 1.75 mGy (screening) vs. 2.4 mGy (symptomatic) at the 95th percentile; various reasons are proposed for the differences. MGDs achieved in the screening service may be lower because of the exacting requirements for radiographer training, characteristics of the patients and equipment quality assurance levels. More precise imaging guidelines, standards and training of symptomatic radiographers performing mammography are suggested to remediate MGDs delivered to the breasts of Irish women attending the symptomatic breast services. PMID:22740646

  9. A comparison of levels of bat flight and foraging activity at 10 meters and 30 meters above drained Carolina bays and reference bays, prior to bay restoration.

    SciTech Connect

    Menzel, Michael, A.; Ford, W., Mark; Edwards, John, W.; Kilgo, John, C.

    2001-08-01

    A technical report of a monitoring study of bat flight and foraging activity above drained and undrained Carolina bays at the Savannah River Site (SRS), located near Aiken, South Carolina. In order to determine if the vegetational community type or structure of the forest community surrounding the bays affected bat activity levels, bat activity was monitored over 3 drained and 3 undrained reference bays surrounded by pine/mixed hardwood communities and 3 drained and 3 undrained reference bays surrounded by pine monocultures. Bat activity was monitored using time expansion bat detectors. Calls were recorded to Sony Professional tape recorders (Sony WMD3). Detectors positioned at 10 m heights were linked directly to the tape recorders. Time expansion radiomicrophones were used to monitor activity at 30 m heights. The radiomicrophones were attached to 2-m diameter helium balloons and suspended approximately 30 m above the forest floor. Calls detected by the radiomicrophones were transmitted via a FM narrowband frequency to a scanner on the ground.

  10. The effects of cognitive rehabilitation on Alzheimer’s dementia patients’ cognitive assessment reference diagnosis system performance based on level of cognitive functioning

    PubMed Central

    Hwang, Jung-Ha; Cha, Hyun-Gyu; Cho, Hyuk-Shin

    2015-01-01

    [Purpose] The purpose of this study is to apply cognitive rehabilitation according to Alzheimer’s disease (AD) patients’ level of cognitive functioning to compare changes in Cognitive Assessment Reference Diagnosis System performance and present standards for effective intervention. [Subjects] Subjects were 30 inpatients diagnosed with AD. Subjects were grouped by Clinical Dementia Rating (CDR) class (CDR-0.5, CDR-1, or CDR-2, n = 10 per group), which is based on level of cognitive functioning, and cognitive rehabilitation was applied for 50 minutes per day, five days per week, for four weeks. [Methods] After cognitive rehabilitation intervention, CARDS tests were conducted to evaluate memory. [Results] Bonferroni tests comparing the three groups revealed that the CDR-0.5 and CDR-1 groups showed significant increases in Delayed 10 word-list, Delayed 10 object-list, Recognition 10 object, and Recent memory performance compared to the CDR-2 group. In addition, the CDR-0.5 group showed significant decreases in Recognition 10 word performance compared to the CDR-1 group. [Conclusion] Cognitive rehabilitation, CDR-0.5 or CDR-1 subjects showed significantly greater memory improvements than CDR-2 subjects. Moreover, was not effective for CDR-2 subjects. PMID:26504315

  11. Patient radiation doses in interventional cardiology in the U.S.: Advisory data sets and possible initial values for U.S. reference levels

    SciTech Connect

    Miller, Donald L.; Hilohi, C. Michael; Spelic, David C.

    2012-10-15

    Purpose: To determine patient radiation doses from interventional cardiology procedures in the U.S and to suggest possible initial values for U.S. benchmarks for patient radiation dose from selected interventional cardiology procedures [fluoroscopically guided diagnostic cardiac catheterization and percutaneous coronary intervention (PCI)]. Methods: Patient radiation dose metrics were derived from analysis of data from the 2008 to 2009 Nationwide Evaluation of X-ray Trends (NEXT) survey of cardiac catheterization. This analysis used deidentified data and did not require review by an IRB. Data from 171 facilities in 30 states were analyzed. The distributions (percentiles) of radiation dose metrics were determined for diagnostic cardiac catheterizations, PCI, and combined diagnostic and PCI procedures. Confidence intervals for these dose distributions were determined using bootstrap resampling. Results: Percentile distributions (advisory data sets) and possible preliminary U.S. reference levels (based on the 75th percentile of the dose distributions) are provided for cumulative air kerma at the reference point (K{sub a,r}), cumulative air kerma-area product (P{sub KA}), fluoroscopy time, and number of cine runs. Dose distributions are sufficiently detailed to permit dose audits as described in National Council on Radiation Protection and Measurements Report No. 168. Fluoroscopy times are consistent with those observed in European studies, but P{sub KA} is higher in the U.S. Conclusions: Sufficient data exist to suggest possible initial benchmarks for patient radiation dose for certain interventional cardiology procedures in the U.S. Our data suggest that patient radiation dose in these procedures is not optimized in U.S. practice.

  12. Pedo-geochemical baseline content levels and soil quality reference values of trace elements in soils from the Mediterranean (Castilla La Mancha, Spain)

    NASA Astrophysics Data System (ADS)

    Ballesta, Raimundo; Bueno, Paz; Rubi, Juan; Giménez, Rosario

    2010-12-01

    To evaluate trace element soil contamination, geochemical baseline contents and reference values need to be established. Pedo-geochemical baseline levels of trace elements in 72 soil samples of 24 soil profiles from the Mediterranean, Castilla La Mancha, are assessed and soil quality reference values are calculated. Reference value contents (in mg kg-1) were: Sc 50.8; V 123.2; Cr 113.4; Co 20.8; Ni 42.6; Cu 27.0; Zn 86.5; Ga 26.7; Ge 1.3; As 16.7; Se 1.4; Br 20.1; Rb 234.7; Sr 1868.4; Y 38.3; Zr 413.1; Nb 18.7; Mo 2.0; Ag 7.8; Cd 4.4; Sn 8.7; Sb 5.7; I 25.4; Cs 14.2; Ba 1049.3; La 348.4; Ce 97.9; Nd 40.1; Sm 10.7; Yb 4.2; Hf 10.0; Ta 4.0; W 5.5; Tl 2.3; Pb 44.2; Bi 2.2; Th 21.6; U 10.3. The contents obtained for some elements are below or close to the detection limit: Co, Ge, Se, Mo, Ag, Cd, Sb, Yb, Hf, Ta, W, Tl and Bi. The element content ranges (the maximum value minus the minimum value) are: Sc 55.0, V 196.0, Cr 346.0, Co 64.4, Ni 188.7, Cu 49.5, Zn 102.3, Ga 28.7, Ge 1.5, As 26.4, Se 0.9, Br 33.0 Rb 432.7, Sr 3372.6, Y 39.8, Zr 523.2, Nb 59.7, Mo 3.9, Ag 10.1, Cd 1.8, Sn 75.2, Sb 9.9, I 68.0, Cs 17.6, Ba 1394.9, La 51.3, Ce 93.5, Nd 52.5, Sm 11.2, Yb 4.2, Hf 11.3, Ta 6.3, W 5.2, Tl 2.1, Pb 96.4, Bi 3.0, Th 24.4, U 16.4 (in mg kg-1). The spatial distribution of the elements was affected mainly by the nature of the bedrock and by pedological processes. The upper limit of expected background variation for each trace element in the soil is documented, as is its range as a criterion for evaluating which sites may require decontamination.

  13. SU-E-P-08: Establishment of Local Diagnostic Reference Levels of Routine Abdomen Exam in Computed Tomography According to Body Weight

    SciTech Connect

    Wang, H; Wang, Y; Weng, H

    2015-06-15

    Purpose: The national diagnostic reference levels (NDRLs) is an efficient, concise and powerful standard for optimizing radiation protection of a patient. However, for each hospital the dose-reducing potential of focusing on establishment of local DRLs (LDRLs). A lot of study reported that Computed tomography exam contributed majority radiation dose in different medical modalities, therefore, routine abdomen CT exam was choose in initial pilot study in our study. Besides the mAs of routine abdomen CT exam was decided automatic exposure control by linear attenuation is relate to body shape of patient. In this study we would like to establish the local diagnostic reference levels of routine abdomen exam in computed tomography according to body weight of patient. Methods and Materials: There are two clinical CT scanners (a Toshiba Aquilion and a Siemens Sensation) were performed in this study. For CT examinations the basic recommended dosimetric quantity is the Computed Tomography Dose Index (CTDI). The patient sample involved 82 adult patients of both sexes and divided into three groups by their body weight (50–60 kg, 60–70 kg, 70–80 kg).Carried out the routine abdomen examinations, and all exposure parameters have been collected and the corresponding CTDIv and DLP values have been determined. The average values were compared with the European DRLs. Results: The majority of patients (75%) were between 50–70 Kg of body weight, the numbers of patient in each group of weight were 40–50:7; 50–60:29; 60–70:33; 70–80:13. The LDRLs in each group were 10.81mGy, 14.46mGy, 20.27mGy and 21.04mGy, respectively. The DLP were 477mGy, 630mGy, 887mGy and 959mGy, respectively. No matter which group the LDRLs were lower than European DRLs. Conclusions: We would like to state that this was a pioneer work in local hospital in Chiayi. We hope that this may lead the way to further developments in Taiwan.

  14. Reference Assessment

    ERIC Educational Resources Information Center

    Bivens-Tatum, Wayne

    2006-01-01

    This article presents interesting articles that explore several different areas of reference assessment, including practical case studies and theoretical articles that address a range of issues such as librarian behavior, patron satisfaction, virtual reference, or evaluation design. They include: (1) "Evaluating the Quality of a Chat Service"…

  15. Reference Services.

    ERIC Educational Resources Information Center

    Bunge, Charles A.

    1999-01-01

    Discusses library reference services. Topics include the historical development of reference services; instruction in library use, particularly in college and university libraries; guidance; information and referral services and how they differ from traditional question-answering service; and future concerns, including user fees and the planning…

  16. Reference frames and reference networks

    NASA Astrophysics Data System (ADS)

    Bosy, Jaroslaw; Krynski, Jan

    2015-12-01

    The summary of research activities concerning reference frames and reference networks performed in Poland in a period of 2011-2014 is presented. It contains the results of research on implementation of IUGG2011 and IAU2012 resolutions on reference systems, implementation of the ETRS89 in Poland, operational work of permanent IGS/ EUREF stations in Poland, operational work of ILRS laser ranging station in Poland, active GNSS station networks in Poland, maintenance of vertical control in Poland, maintenance and modernization of gravity control, and maintenance of magnetic control in Poland. The bibliography of the related works is given in references.

  17. Radiation dose in coronary angiography and intervention: initial results from the establishment of a multi-centre diagnostic reference level in Queensland public hospitals

    SciTech Connect

    Crowhurst, James A; Whitby, Mark; Thiele, David; Halligan, Toni; Westerink, Adam; Crown, Suzanne; Milne, Jillian

    2014-09-15

    Radiation dose to patients undergoing invasive coronary angiography (ICA) is relatively high. Guidelines suggest that a local benchmark or diagnostic reference level (DRL) be established for these procedures. This study sought to create a DRL for ICA procedures in Queensland public hospitals. Data were collected for all Cardiac Catheter Laboratories in Queensland public hospitals. Data were collected for diagnostic coronary angiography (CA) and single-vessel percutaneous intervention (PCI) procedures. Dose area product (P{sub KA}), skin surface entrance dose (K{sub AR}), fluoroscopy time (FT), and patient height and weight were collected for 3 months. The DRL was set from the 75th percentile of the P{sub KA.} 2590 patients were included in the CA group where the median FT was 3.5 min (inter-quartile range = 2.3–6.1). Median K{sub AR} = 581 mGy (374–876). Median P{sub KA} = 3908 uGym{sup 2} (2489–5865) DRL = 5865 uGym{sup 2}. 947 patients were included in the PCI group where median FT was 11.2 min (7.7–17.4). Median K{sub AR} = 1501 mGy (928–2224). Median P{sub KA} = 8736 uGym{sup 2} (5449–12,900) DRL = 12,900 uGym{sup 2}. This study established a benchmark for radiation dose for diagnostic and interventional coronary angiography in Queensland public facilities.

  18. Study of the Vitamin D Levels in Patients Referred to Clinical Laboratories in Mashhad in 2015 and their Relationship with the Patients’ Lipid Profiles

    PubMed Central

    Shamsian, Ali Akbar; Rezaee, Seyyed Abdolrahim; Rajabiian, Majid; Moghaddam, Habibolah Taghizadeh; Saeidi, Masumeh; Bahreini, Abbas

    2016-01-01

    Introduction Vitamin D is a steroid hormone that has a significant role in the metabolism of minerals, especially calcium and phosphorus; it also is a major determinant of the strength of bones. This hormone has a significant effect on three major health issues that people worldwide encounter, i.e., high blood pressure, cancer, and diabetes. Considering the limited and dispersed studies on the prevalence of vitamin D deficiency in Iran and the relationship of vitamin D with lipid profiles in different people, this study was conducted to determine the vitamin D levels in patients and its relationship with their lipid profiles. Methods A retrospective cross-sectional study was conducted in 2015 on 1,110 patients who were referred to the two laboratories at Jihad Daneshgahi and to eight specialist laboratories in Mashhad through random sampling of patients for whom serum vitamin D and serum lipid tests were prescribed. The data that were obtained were entered into SPSS 13 software. Results Sixty-eight percent of the patients in the study were deficient in vitamin D. The vitamin D levels in males were significantly lower than those in females (p < 0.05). The relationship between age and vitamin D deficiency was significant as well (p < 0.05). A positive and significant relationship was observed between age and vitamin D deficiency (p = 0.000, r = 0.187), i.e., vitamin D deficiency was more apparent in patients whose ages were in the range of 40–59. The relationship between the levels of vitamin D and serum lipids was significant and positive (p = 0.05), with the exception of LDL. Conclusion About two-thirds of the population that was studied had a vitamin D deficiency. There was a positive and significant relationship between serum vitamin D and serum lipids and serum calcium. The results of this study showed the necessity for more research and the implementation of preventive measures related to vitamin D deficiency. It is recommended that vitamin D enrichment

  19. Ready Reference.

    ERIC Educational Resources Information Center

    Koltay, Emery

    1999-01-01

    Includes the following ready reference information: "Publishers' Toll-Free Telephone Numbers"; "How to Obtain an ISBN (International Standard Book Number)"; "How to Obtain an ISSN (International Standard Serial Number)"; and "How to Obtain an SAN (Standard Address Number)". (AEF)

  20. EPA QUICK REFERENCE GUIDES

    EPA Science Inventory

    EPA Quick Reference Guides are compilations of information on chemical and biological terrorist agents. The information is presented in consistent format and includes agent characteristics, release scenarios, health and safety data, real-time field detection, effect levels, samp...

  1. Cross-Platform Microarray Meta-Analysis for the Mouse Jejunum Selects Novel Reference Genes with Highly Uniform Levels of Expression

    PubMed Central

    Meyer, Florian R. L.; Grausgruber, Heinrich; Binter, Claudia; Mair, Georg E.; Guelly, Christian; Vogl, Claus; Steinborn, Ralf

    2013-01-01

    Reference genes (RGs) with uniform expression are used for normalization of reverse transcription quantitative PCR (RT-qPCR) data. Their optimization for a specific biological context, e.g. a specific tissue, has been increasingly considered. In this article, we compare RGs identified by expression data meta-analysis restricted to the context tissue, the jejunum of Mus musculus domesticus, i) to traditional RGs, ii) to expressed interspersed repeated DNA elements, and iii) to RGs identified by meta-analysis of expression data from diverse tissues and conditions. To select the set of candidate RGs, we developed a novel protocol for the cross-platform meta-analysis of microarray data. The expression stability of twenty-four putative RGs was analysed by RT-qPCR in at least 14 jejunum samples of the mouse strains C57Bl/6N, CD1, and OF1. Across strains, the levels of expression of the novel RGs Plekha7, Zfx, and Ube2v1 as well as of Oaz1 varied less than two-fold irrespective of genotype, sex or their combination. The gene set consisting of Plekha7 and Oaz1 showed superior expression stability analysed with the tool RefFinder. The novel RGs are functionally diverse. This facilitates expression studies over a wide range of conditions. The highly uniform expression of the optimized RGs in the jejunum points towards their involvement in tightly regulated pathways in this tissue. We also applied our novel protocol of cross-microarray platform meta-analysis to the identification of RGs in the duodenum, the ileum and the entire small intestine. The selection of RGs with improved expression stability in a specific biological context can reduce the number of RGs for the normalization step of RT-qPCR expression analysis, thus reducing the number of samples and experimental costs. PMID:23671661

  2. Nicotine, acetanilide and urea multi-level2H-,13C- and15N-abundance reference materials for continuous-flow isotope ratio mass spectrometry

    USGS Publications Warehouse

    Schimmelmann, A.; Albertino, A.; Sauer, P.E.; Qi, H.; Molinie, R.; Mesnard, F.

    2009-01-01

    Accurate determinations of stable isotope ratios require a calibration using at least two reference materials with different isotopic compositions to anchor the isotopic scale and compensate for differences in machine slope. Ideally, the S values of these reference materials should bracket the isotopic range of samples with unknown S values. While the practice of analyzing two isotopically distinct reference materials is common for water (VSMOW-SLAP) and carbonates (NBS 19 and L-SVEC), the lack of widely available organic reference materials with distinct isotopic composition has hindered the practice when analyzing organic materials by elemental analysis/isotope ratio mass spectrometry (EA-IRMS). At present only L-glutamic acids USGS40 and USGS41 satisfy these requirements for ??13C and ??13N, with the limitation that L-glutamic acid is not suitable for analysis by gas chromatography (GC). We describe the development and quality testing of (i) four nicotine laboratory reference materials for on-line (i.e. continuous flow) hydrogen reductive gas chromatography-isotope ratio mass-spectrometry (GC-IRMS), (ii) five nicotines for oxidative C, N gas chromatography-combustion-isotope ratio mass-spectrometry (GC-C-IRMS, or GC-IRMS), and (iii) also three acetanilide and three urea reference materials for on-line oxidative EA-IRMS for C and N. Isotopic off-line calibration against international stable isotope measurement standards at Indiana University adhered to the 'principle of identical treatment'. The new reference materials cover the following isotopic ranges: ??2Hnicotine -162 to -45%o, ??13Cnicotine -30.05 to +7.72%, ?? 15Nnicotine -6.03 to +33.62%; ??15N acetanilide +1-18 to +40.57%; ??13Curea -34.13 to +11.71%, ??15Nurea +0.26 to +40.61% (recommended ?? values refer to calibration with NBS 19, L-SVEC, IAEA-N-1, and IAEA-N-2). Nicotines fill a gap as the first organic nitrogen stable isotope reference materials for GC-IRMS that are available with different ??13N

  3. Nicotine, acetanilide and urea multi-level 2H-, 13C- and 15N-abundance reference materials for continuous-flow isotope ratio mass spectrometry.

    PubMed

    Schimmelmann, Arndt; Albertino, Andrea; Sauer, Peter E; Qi, Haiping; Molinie, Roland; Mesnard, François

    2009-11-01

    Accurate determinations of stable isotope ratios require a calibration using at least two reference materials with different isotopic compositions to anchor the isotopic scale and compensate for differences in machine slope. Ideally, the delta values of these reference materials should bracket the isotopic range of samples with unknown delta values. While the practice of analyzing two isotopically distinct reference materials is common for water (VSMOW-SLAP) and carbonates (NBS 19 and L-SVEC), the lack of widely available organic reference materials with distinct isotopic composition has hindered the practice when analyzing organic materials by elemental analysis/isotope ratio mass spectrometry (EA-IRMS). At present only L-glutamic acids USGS40 and USGS41 satisfy these requirements for delta13C and delta15N, with the limitation that L-glutamic acid is not suitable for analysis by gas chromatography (GC). We describe the development and quality testing of (i) four nicotine laboratory reference materials for on-line (i.e. continuous flow) hydrogen reductive gas chromatography-isotope ratio mass-spectrometry (GC-IRMS), (ii) five nicotines for oxidative C, N gas chromatography-combustion-isotope ratio mass-spectrometry (GC-C-IRMS, or GC-IRMS), and (iii) also three acetanilide and three urea reference materials for on-line oxidative EA-IRMS for C and N. Isotopic off-line calibration against international stable isotope measurement standards at Indiana University adhered to the 'principle of identical treatment'. The new reference materials cover the following isotopic ranges: delta2H(nicotine) -162 to -45 per thousand, delta13C(nicotine) -30.05 to +7.72 per thousand, delta15N(nicotine) -6.03 to +33.62 per thousand; delta15N(acetanilide) +1.18 to +40.57 per thousand; delta13C(urea) -34.13 to +11.71 per thousand, delta15N(urea) +0.26 to +40.61 per thousand (recommended delta values refer to calibration with NBS 19, L-SVEC, IAEA-N-1, and IAEA-N-2). Nicotines fill a gap as

  4. Poroelastic references

    SciTech Connect

    Morency, Christina

    2014-12-12

    This file contains a list of relevant references on the Biot theory (forward and inverse approaches), the double-porosity and dual-permeability theory, and seismic wave propagation in fracture porous media, in RIS format, to approach seismic monitoring in a complex fractured porous medium such as Brady?s Geothermal Field.

  5. Ready Reference.

    ERIC Educational Resources Information Center

    Koltay, Emery

    2001-01-01

    Includes four articles that relate to ready reference, including a list of publishers' toll-free telephone numbers and Web sites; how to obtain an ISBN (International Standard Book Number) and an ISSN (International Standard Serial Number); and how to obtain an SAN (Standard Address Number), for organizations that are involved in the book…

  6. Patient Dose During Carotid Artery Stenting With Embolic-Protection Devices: Evaluation With Radiochromic Films and Related Diagnostic Reference Levels According to Factors Influencing the Procedure

    SciTech Connect

    D'Ercole, Loredana; Quaretti, Pietro; Cionfoli, Nicola; Klersy, Catherine; Bocchiola, Milena; Rodolico, Giuseppe; Azzaretti, Andrea; Lisciandro, Francesco; Cascella, Tommaso; Zappoli Thyrion, Federico

    2013-04-15

    To measure the maximum entrance skin dose (MESD) on patients undergoing carotid artery stenting (CAS) using embolic-protection devices, to analyze the dependence of dose and exposure parameters on anatomical, clinical, and technical factors affecting the procedure complexity, to obtain some local diagnostic reference levels (DRLs), and to evaluate whether overcoming DRLs is related to procedure complexity. MESD were evaluated with radiochromic films in 31 patients (mean age 72 {+-} 7 years). Five of 33 (15 %) procedures used proximal EPD, and 28 of 33 (85 %) procedures used distal EPD. Local DRLs were derived from the recorded exposure parameters in 93 patients (65 men and 28 women, mean age 73 {+-} 9 years) undergoing 96 CAS with proximal (33 %) or distal (67 %) EPD. Four bilateral lesions were included. MESD values (mean 0.96 {+-} 0.42 Gy) were <2 Gy without relevant dependence on procedure complexity. Local DRL values for kerma area product (KAP), fluoroscopy time (FT), and number of frames (N{sub FR}) were 269 Gy cm{sup 2}, 28 minutes, and 251, respectively. Only simultaneous bilateral treatment was associated with KAP (odds ratio [OR] 10.14, 95 % confidence interval [CI] 1-102.7, p < 0.05) and N{sub FR} overexposures (OR 10.8, 95 % CI 1.1-109.5, p < 0.05). Type I aortic arch decreased the risk of FT overexposure (OR 0.4, 95 % CI 0.1-0.9, p = 0.042), and stenosis {>=} 90 % increased the risk of N{sub FR} overexposure (OR 2.8, 95 % CI 1.1-7.4, p = 0.040). At multivariable analysis, stenosis {>=} 90 % (OR 2.8, 95 % CI 1.1-7.4, p = 0.040) and bilateral treatment (OR 10.8, 95 % CI 1.1-109.5, p = 0.027) were associated with overexposure for two or more parameters. Skin doses are not problematic in CAS with EPD because these procedures rarely lead to doses >2 Gy.

  7. Relevance of biotic pathways to the long-term regulation of nuclear-waste disposal. Topical Report on reference western arid low-level sites

    NASA Astrophysics Data System (ADS)

    McKenzie, D. H.; Cadwell, L. L.; Eberhardt, L. E.; Kennedy, W. E., Jr.; Peloquin, R. A.; Simmons, M. A.

    1982-10-01

    An order of magnitude estimate for the potential dose to man resulting from biotic transport mechanisms at a reference western arid lowlevel waste site was developed. A description of the reference site is presented that includes the waste inventories, site characteristics and biological communities. Parameter values for biotic transport processes are based on data reported in current literature. Transport and exposure scenarios are developed for assessing biotic transport during 100 years following site closure. Calculations of radionuclide decay and waste container decomposition are made to estimate the quantities available for biotic transport. Dose to a man occupying the reference site following the 100 years of biotic transport are calculated. Dose to man estimates as a result of biotic transport are estimated to be of the same order of magnitude as the dose resulting from the more commonly evaluated human intrusion scenario.

  8. On Development and Characterisation of a Mobile and Metrologically Traceable Reference Gas Generator for Ammonia and Other Reactive Species in Ambient Air Levels

    NASA Astrophysics Data System (ADS)

    Leuenberger, Daiana; Pascale, Céline; Guillevic, Myriam; Ackermann, Andreas; Niederhauser, Bernhard

    2016-04-01

    Ammonia NH3 in the atmosphere is the major precursor for neutralising atmospheric acids and is thus affecting not only the long-range transport of sulphur dioxide and nitrogen oxides but also stabilies secondary particulate matter. These aerosols have negative impacts on air quality and human health. Moreover, they negatively affect terrestrial ecosystems after deposition. NH3 has been included in the air quality monitoring networks and emission reduction directives of European nations. Atmospheric concentrations are in the order of 0.5-500 nmol/mol. However, the lowest substance amount fraction of available certified reference material (CRM) is 30 μmol/mol. The EMRP JRP ENV55 MetNH3 aims at overcoming this discrepancy by assessing and developing novel approaches for the production of CRM and measurement methods. The Federal Institute of Metrology METAS has developed a mobile and metrologically traceable reference gas generator for reactive gases (ReGaS1). This device is based on the specific temperature dependent permeation of the reference substance through a membrane into a flow of carrier gas and subsequent dynamic dilution to desired amount fractions. The characteristics of individual components lead to the uncertainty estimation for the generated NH3 gas mixture according to GUM, which is aimed to be <3 %. Here we present insights into the development of said instrument and results of the first performance tests. Moreover, we include results of the study on adsorption/desorption effects in dry as well as humidified matrix gas into the discussion on the generation of reference gas mixtures.

  9. Feasibility study for producing a carrot/potato matrix reference material for 11 selected pesticides at EU MRL level: material processing, homogeneity and stability assessment.

    PubMed

    Saldanha, Helena; Sejerøe-Olsen, Berit; Ulberth, Franz; Emons, Hendrik; Zeleny, Reinhard

    2012-05-01

    The feasibility for producing a matrix reference material for selected pesticides in a carrot/potato matrix was investigated. A commercially available baby food (carrot/potato-based mash) was spiked with 11 pesticides at the respective EU maximum residue limits (MRLs), and further processed by either freezing or freeze-drying. Batches of some 150 units were produced per material type. First, the materials were assessed for the relative amount of pesticide recovered after processing (ratio of pesticide concentration in the processed material to the initially spiked pesticide concentration). In addition, the materials' homogeneity (bottle-to-bottle variation), and the short-term (1 month) and mid-term (5 months) stability at different temperatures were assessed. For this, an in-house validated GC-EI-MS method operated in the SIM mode with a sample preparation procedure based on the QuEChERS ("quick, easy, cheap, effective, rugged, and safe") principle was applied. Measurements on the frozen material provided the most promising results (smallest analyte losses during production), and also freeze-drying proved to be a suitable alternative processing technique for most of the investigated pesticides. Both the frozen and the freeze-dried material showed to be sufficiently homogeneous for the intended use, and storage at -20°C for 5 months did not reveal any detectable material degradation. The results constitute an important step towards the development of a pesticide matrix reference material. PMID:26434333

  10. Hair Mercury Levels in U.S. Children and Women of Childbearing Age: Reference Range Data from NHANES 1999–2000

    PubMed Central

    McDowell, Margaret A.; Dillon, Charles F.; Osterloh, John; Bolger, P. Michael; Pellizzari, Edo; Fernando, Reshan; de Oca, Ruben Montes; Schober, Susan E.; Sinks, Thomas; Jones, Robert L.; Mahaffey, Kathryn R.

    2004-01-01

    Exposure to methyl mercury, a risk factor for neurodevelopmental toxicity, was assessed in U.S. children 1–5 years of age (n = 838) and women 16–49 years of age (n = 1,726) using hair mercury analysis during the 1999–2000 National Health and Nutrition Examination Survey (NHANES). The data are nationally representative and are based on analysis of cross-sectional data for the non-institutionalized, U.S. household population. The survey consisted of interviews conducted in participants’ homes and standardized health examinations conducted in mobile examination centers. Distributions of total hair mercury levels expressed as micrograms per gram hair Hg and the association of hair Hg levels with sociodemographic characteristics and fish consumption are reported. Geometric mean (standard error of the geometric mean) hair mercury was 0.12 μg/g (0.01 μg/g) in children, and 0.20 μg/g (0.02 μg/g) in women. Among frequent fish consumers, geometric mean hair mercury levels were 3-fold higher for women (0.38 vs. 0.11 μg/g) and 2-fold higher for children (0.16 vs. 0.08 μg/g) compared with nonconsumers. The NHANES 1999–2000 data provide population-based data on hair mercury concentrations for women and children in the United States. Hair mercury levels were associated with age and fish consumption frequency. PMID:15289161

  11. Climate Change, Sea-Level Rise and Implications for Coastal and Estuarine Shoreline Management with Particular Reference to the Ecology of Intertidal Benthic Macrofauna in NW Europe

    PubMed Central

    Fujii, Toyonobu

    2012-01-01

    In many European estuaries, extensive areas of intertidal habitats consist of bare mudflats and sandflats that harbour a very high abundance and biomass of macrobenthic invertebrates. The high stocks of macrobenthos in turn provide important food sources for the higher trophic levels such as fish and shorebirds. Climate change and associated sea-level rise will have potential to cause changes in coastal and estuarine physical properties in a number of ways and thereby influence the ecology of estuarine dependent organisms. Although the mechanisms involved in biological responses resulting from such environmental changes are complex, the ecological effects are likely to be significant for the estuarine benthic macrofauna and hence the consumers they support. This paper reviews the utilisation patterns of estuarine intertidal habitats by shorebirds, fish and crustaceans, as well as factors affecting the distribution, abundance and biomass of estuarine macrobenthos that is known to be important food source for these estuarine predators. This study also provides simple conceptual models of the likely impacts of sea-level rise on the physical and biological elements of estuarine intertidal habitats, and implications of these results are discussed in the context of sustainable long term flood and coastal management in estuarine environments. PMID:24832510

  12. Levels of toxic elements and functional structure in populations of small mammals under conditions of technogenic pollution (with reference to the bank vole)

    SciTech Connect

    Mukhacheva, S.V.; Bezel, V.S.

    1995-05-01

    The levels and the character of accumulation of heavy metals (Pb, Cd, Cu, Zn) in organs and tissues of bank voles, living under conditions of technogenic pollution (near a copper-smelting plant) and on the control territory, were studied. The fundamental distinctions in the character of accumulation of physiologically extraneous elements (lead and cadmium) and elements required for normal functioning (copper and zinc) were found. It was shown that the bank vole population responds to technogenic pollution of the environment depending on the ecological-functional features of the subpopulational groups that form this population. 4 refs., 3 figs., 2 tabs.

  13. A mixture model with a reference-based automatic selection of components for disease classification from protein and/or gene expression levels

    PubMed Central

    2011-01-01

    Background Bioinformatics data analysis is often using linear mixture model representing samples as additive mixture of components. Properly constrained blind matrix factorization methods extract those components using mixture samples only. However, automatic selection of extracted components to be retained for classification analysis remains an open issue. Results The method proposed here is applied to well-studied protein and genomic datasets of ovarian, prostate and colon cancers to extract components for disease prediction. It achieves average sensitivities of: 96.2 (sd = 2.7%), 97.6% (sd = 2.8%) and 90.8% (sd = 5.5%) and average specificities of: 93.6% (sd = 4.1%), 99% (sd = 2.2%) and 79.4% (sd = 9.8%) in 100 independent two-fold cross-validations. Conclusions We propose an additive mixture model of a sample for feature extraction using, in principle, sparseness constrained factorization on a sample-by-sample basis. As opposed to that, existing methods factorize complete dataset simultaneously. The sample model is composed of a reference sample representing control and/or case (disease) groups and a test sample. Each sample is decomposed into two or more components that are selected automatically (without using label information) as control specific, case specific and not differentially expressed (neutral). The number of components is determined by cross-validation. Automatic assignment of features (m/z ratios or genes) to particular component is based on thresholds estimated from each sample directly. Due to the locality of decomposition, the strength of the expression of each feature across the samples can vary. Yet, they will still be allocated to the related disease and/or control specific component. Since label information is not used in the selection process, case and control specific components can be used for classification. That is not the case with standard factorization methods. Moreover, the component selected by proposed method as disease specific

  14. Development of national reference energy mean emission levels for the FHWA traffic noise model (FHWA TNM (trade name)), version 1.0. Final report, July 1993-November 1995

    SciTech Connect

    Fleming, G.G.; Rapoza, A.S.; Lee, C.S.Y.

    1995-11-01

    During the period, July 1993 through November 1995, the U.S. Department of Transportation , Research and Special Programs Administration, John A. Volpe National Transportation Systems Center (Volpe Center), Acoustics Facility. This report also presents the results of the study, including the measurement, data reduction and analysis procedures used to develop the Data Base. It discusses data for constant-flow and interrupted-flow roadway traffic, and data related to vehicle subsource heights. This report also presents the statistical methodology used to establish the Data Base for the FHWA TNM. Sound level regressions are presented as a function of several parameters, including vehicle speed, vehicle type, one-third octave-band frequency, roadway pavement type, roadway grade, traffic-flow condition and vehicle subsource height.

  15. Preliminary report on the geology and hydrology of Mortandad Canyon near Los Alamos, New Mexico, with reference to disposal of liquid low-level radioactive waste

    USGS Publications Warehouse

    Baltz, E.H.; Abrahams, J.H., Jr.; Purtyman, W.D.

    1963-01-01

    The U.S. Geological Survey, in cooperation with the U.S. Atomic Energy Commission and the Los Alamos Scientific Laboratory, selected the upper part of Mortandad Canyon near Los Alamos, New Mexico for a site for disposal of treated liquid low-level radioactive waste. This report summarizes the part of a study of the geology and hydrology that was done from October 1960 through June 1961. Additional work is being continued. Mortandad Canyon is a narrow east-southeast-trending canyon about 9? miles long that heads on the central part of the Pajarito Plateau at an altitude of about 7,340 feet. The canyon is tributary to the Rio Grande. The drainage area of the part of Mortandad Canyon that was investigated is about 2 square miles, and the total drainage area is about 4.9 square miles. The Pajarito Plateau is capped by the Bandelier Tuff of Pleistocene age. Mortandad Canyon is cut in the Bandelier, and alluvium covers the floor of the canyon to depths ranging from less than 1 foot to as much as 100 feet. The Bandelier is underlain by silt, sand, conglomerate, and interbedded basalt of the Santa Fe Group of Miocene, Pliocene, and Pleistocene(?) age. Some ground water is perched in the alluvium in the canyon; however, the top of the main aquifer is in the Santa Fe Group at a depth of about 990 feet below the canyon floor. Joints in the Bandelier Tuff probably were caused by shrinkage of the tuff during cooling. The joints range in width from hairline cracks to fissures several inches wide. Water can infiltrate along the open joints where the Bandelier is at the surface; however, soil, alluvial fill, and autochthonous clay inhibit infiltration on the tops of mesas and probably in the alluvium-floored canyons also. Thirty-three test holes, each less than 100 feet deep, were drilled in 10 lies across Mortandad Canyon from the western margin of the study area to just west of the Los Alamos-Santa Fe County line. Ten of the holes were cased for observation wells to measure

  16. Library Reference Services.

    ERIC Educational Resources Information Center

    Miller, Constance; And Others

    1985-01-01

    Seven articles on library reference services highlight reference obsolescence in academic libraries, major studies of unobtrusive reference tests, methods for evaluating reference desk performance, reference interview evaluation, problems of reference desk control, online searching by end users, and reference collection development in…

  17. Genetics Home Reference: isolated hyperchlorhidrosis

    MedlinePlus

    ... is characterized by the excessive loss of salt (sodium chloride or NaCl) in sweat. In particular, "hyperchlorhidrosis" refers ... levels of chloride found in sweat, although both sodium and chloride are released. Because the salt is abnormally released ...

  18. Reference Frames and Relativity.

    ERIC Educational Resources Information Center

    Swartz, Clifford

    1989-01-01

    Stresses the importance of a reference frame in mechanics. Shows the Galilean transformation in terms of relativity theory. Discusses accelerated reference frames and noninertial reference frames. Provides examples of reference frames with diagrams. (YP)

  19. SPAR reference manual update SPAR level 15

    NASA Technical Reports Server (NTRS)

    Whetstone, W. D.

    1980-01-01

    Command runstream elements are presented for analyzing structural systems that are composed of a number of cyclically symmetrical sectors. Provisions are included for systems in which each cyclically symmetrical sector also possesses a plane of reflective symmetry. The following types of analysis may be performed: static analysis with and without preload, vibrational analysis with and without preload, and buckling analysis with and without preload.

  20. Comparisons of CVID and IgGSD: Referring Physicians, Autoimmune Conditions, Pneumovax Reactivity, Immunoglobulin Levels, Blood Lymphocyte Subsets, and HLA-A and -B Typing in 432 Adult Index Patients

    PubMed Central

    Barton, James C.; Bertoli, Luigi F.; Barton, J. Clayborn

    2014-01-01

    Common variable immunodeficiency (CVID) and immunoglobulin (Ig) G subclass deficiency (IgGSD) are heterogeneous disorders characterized by respiratory tract infections, selective Ig isotype deficiencies, and impaired antibody responses to polysaccharide antigens. Using univariable analyses, we compared observations in 34 CVID and 398 IgGSD adult index patients (81.9% women) referred to a hematology/oncology practice. Similarities included specialties of referring physicians, mean ages, proportions of women, reactivity to Pneumovax, median serum IgG3 and IgG4 levels, median blood CD56+/CD16+ lymphocyte levels, positivity for HLA-A and -B types, and frequencies of selected HLA-A, -B haplotypes. Dissimilarities included greater prevalence of autoimmune conditions, lower median IgG, IgA, and IgM, and lower median CD19+, CD3+/CD4+, and CD3+/CD8+ blood lymphocytes in CVID patients. Prevalence of Sjögren's syndrome and hypothyroidism was significantly greater in CVID patients. Combined subnormal IgG1/IgG3 occurred in 59% and 29% of CVID and IgGSD patients, respectively. Isolated subnormal IgG3 occurred in 121 IgGSD patients (88% women). Logistic regression on CVID (versus IgGSD) revealed a significant positive association with autoimmune conditions and significant negative associations with IgG1, IgG3, and IgA and CD56+/CD16+ lymphocyte levels, but the odds ratio was increased for autoimmune conditions alone (6.9 (95% CI 1.3, 35.5)). PMID:25295286

  1. Reference Service Policy Statement.

    ERIC Educational Resources Information Center

    Young, William F.

    This reference service policy manual provides general guidelines to encourage reference service of the highest possible quality and to insure uniform practice. The policy refers only to reference service in the University Libraries and is intended for use in conjunction with other policies and procedures issued by the Reference Services Division.…

  2. Computers and Reference Service.

    ERIC Educational Resources Information Center

    Purcell, Royal

    1989-01-01

    Discusses the current status and potential for automated library reference services in the areas of community information systems, online catalogs, remote online reference services, and telephone reference services. Several models of the reference procedure which might be used in developing expert systems are examined. (19 references) (CLB)

  3. Higher levels of phosphorylated Y1472 on GluN2B subunits in the frontal cortex of aged mice are associated with good spatial reference memory, but not cognitive flexibility.

    PubMed

    Zamzow, Daniel R; Elias, Val; Acosta, Varinia A; Escobedo, Emily; Magnusson, Kathy R

    2016-06-01

    The N-methyl-D-aspartate receptor (NMDAr) is particularly vulnerable to aging. The GluN2B subunit of the NMDAr, compared to other NMDAr subunits, suffers the greatest losses of expression in the aging brain, especially in the frontal cortex. While expression levels of GluN2B mRNA and protein in the aged brain are well documented, there has been little investigation into age-related posttranslational modifications of the subunit. In this study, we explored some of the mechanisms that may promote differences in the NMDAr complex in the frontal cortex of aged animals. Two ages of mice, 3 and 24 months, were behaviorally tested in the Morris water maze. The frontal cortex and hippocampus from each mouse were subjected to differential centrifugation followed by solubilization in Triton X-100. Proteins from Triton-insoluble membranes, Triton-soluble membranes, and intracellular membranes/cytosol were examined by Western blot. Higher levels of GluN2B tyrosine 1472 phosphorylation in frontal cortex synaptic fractions of old mice were associated with better reference learning but poorer cognitive flexibility. Levels of GluN2B phosphotyrosine 1336 remained steady, but there were greater levels of the calpain-induced 115 kDa GluN2B cleavage product on extrasynaptic membranes in these old good learners. There was an age-related increase in calpain activity, but it was not associated with better learning. These data highlight a unique aging change for aged mice with good spatial learning that might be detrimental to cognitive flexibility. This study also suggests that higher levels of truncated GluN2B on extrasynaptic membranes are not deleterious to spatial memory in aged mice. PMID:27094400

  4. Generalizing indexical-functional reference

    SciTech Connect

    Schoppers, M.; Shu, R.

    1996-12-31

    The goals of situated agents generally do not specify particular objects: they require only that some suitable object should be chosen and manipulated (e.g. any red block). Situated agents engaged in deictic reference grounding, however, may well track a chosen referent object with such fixity of purpose that an unchosen object may be regarded as an obstacle even though it satisfies the agent`s goals. In earlier work this problem was bridged by hand-coding. This paper lifts the problem to the symbol level, endowing agents with perceptual referent selection actions and performing those actions as required to allow or disallow opportunistic re-selection of referents. Our work preserves the ability of situated agents to find and track specific objects, adds an ability to automatically exploit the opportunities allowed by nonspecific references, and provides a starting point for studying how much opportunistic perception is appropriate.

  5. Magnetohydrodynamic inertial reference system

    NASA Astrophysics Data System (ADS)

    Eckelkamp-Baker, Dan; Sebesta, Henry R.; Burkhard, Kevin

    2000-07-01

    Optical platforms increasingly require attitude knowledge and optical instrument pointing at sub-microradian accuracy. No low-cost commercial system exists to provide this level of accuracy for guidance, navigation, and control. The need for small, inexpensive inertial sensors, which may be employed in pointing control systems that are required to satisfy angular line-of-sight stabilization jitter error budgets to levels of 1-3 microradian rms and less, has existed for at least two decades. Innovations and evolutions in small, low-noise inertial angular motion sensor technology and advances in the applications of the global positioning system have converged to allow improvement in acquisition, tracking and pointing solutions for a wide variety of payloads. We are developing a small, inexpensive, and high-performance inertial attitude reference system that uses our innovative magnetohydrodynamic angular rate sensor technology.

  6. Live, Digital Reference.

    ERIC Educational Resources Information Center

    Kenney, Brian

    2002-01-01

    Discusses digital reference services, also known as virtual reference, chat reference, or online reference, based on a round table discussion at the 2002 American Library Association annual conference in Atlanta. Topics include numbers and marketing; sustainability; competition and models; evaluation methods; outsourcing; staffing and training;…

  7. Fundamentals of Reference

    ERIC Educational Resources Information Center

    Mulac, Carolyn M.

    2012-01-01

    The all-in-one "Reference reference" you've been waiting for, this invaluable book offers a concise introduction to reference sources and services for a variety of readers, from library staff members who are asked to work in the reference department to managers and others who wish to familiarize themselves with this important area of…

  8. Statistical Reference Datasets

    National Institute of Standards and Technology Data Gateway

    Statistical Reference Datasets (Web, free access)   The Statistical Reference Datasets is also supported by the Standard Reference Data Program. The purpose of this project is to improve the accuracy of statistical software by providing reference datasets with certified computational results that enable the objective evaluation of statistical software.

  9. Human health screening level risk assessments of tertiary-butyl acetate (TBAC): calculated acute and chronic reference concentration (RfC) and Hazard Quotient (HQ) values based on toxicity and exposure scenario evaluations.

    PubMed

    Bus, James S; Banton, Marcy I; Faber, Willem D; Kirman, Christopher R; McGregor, Douglas B; Pourreau, Daniel B

    2015-02-01

    A screening level risk assessment has been performed for tertiary-butyl acetate (TBAC) examining its primary uses as a solvent in industrial and consumer products. Hazard quotients (HQ) were developed by merging TBAC animal toxicity and dose-response data with population-level, occupational and consumer exposure scenarios. TBAC has a low order of toxicity following subchronic inhalation exposure, and neurobehavioral changes (hyperactivity) in mice observed immediately after termination of exposure were used as conservative endpoints for derivation of acute and chronic reference concentration (RfC) values. TBAC is not genotoxic but has not been tested for carcinogenicity. However, TBAC is unlikely to be a human carcinogen in that its non-genotoxic metabolic surrogates tertiary-butanol (TBA) and methyl tertiary butyl ether (MTBE) produce only male rat α-2u-globulin-mediated kidney cancer and high-dose specific mouse thyroid tumors, both of which have little qualitative or quantitative relevance to humans. Benchmark dose (BMD)-modeling of the neurobehavioral responses yielded acute and chronic RfC values of 1.5 ppm and 0.3 ppm, respectively. After conservative modeling of general population and near-source occupational and consumer product exposure scenarios, almost all HQs were substantially less than 1. HQs exceeding 1 were limited to consumer use of automotive products and paints in a poorly ventilated garage-sized room (HQ = 313) and occupational exposures in small and large brake shops using no personal protective equipment or ventilation controls (HQs = 3.4-126.6). The screening level risk assessments confirm low human health concerns with most uses of TBAC and indicate that further data-informed refinements can address problematic health/exposure scenarios. The assessments also illustrate how tier-based risk assessments using read-across toxicity information to metabolic surrogates reduce the need for comprehensive animal testing. PMID:25629921

  10. Tank characterization reference guide

    SciTech Connect

    De Lorenzo, D.S.; DiCenso, A.T.; Hiller, D.B.; Johnson, K.W.; Rutherford, J.H.; Smith, D.J.; Simpson, B.C.

    1994-09-01

    Characterization of the Hanford Site high-level waste storage tanks supports safety issue resolution; operations and maintenance requirements; and retrieval, pretreatment, vitrification, and disposal technology development. Technical, historical, and programmatic information about the waste tanks is often scattered among many sources, if it is documented at all. This Tank Characterization Reference Guide, therefore, serves as a common location for much of the generic tank information that is otherwise contained in many documents. The report is intended to be an introduction to the issues and history surrounding the generation, storage, and management of the liquid process wastes, and a presentation of the sampling, analysis, and modeling activities that support the current waste characterization. This report should provide a basis upon which those unfamiliar with the Hanford Site tank farms can start their research.

  11. National Nutrition Education Clearing House Reference List, General Teacher References.

    ERIC Educational Resources Information Center

    National Nutrition Education Clearing House, Berkeley, CA.

    References applicable to both elementary and secondary levels, as well as background information of importance to teachers in the field of nutrition and nutrition education, are included in this bibliography. Although not a comprehensive list, resources include books, pamphlets, curriculum guides, bibliographies, newsletters, article reprints, and…

  12. Application of the hybrid approach to the benchmark dose of urinary cadmium as the reference level for renal effects in cadmium polluted and non-polluted areas in Japan

    SciTech Connect

    Suwazono, Yasushi; Nogawa, Kazuhiro; Uetani, Mirei; Nakada, Satoru; Kido, Teruhiko; Nakagawa, Hideaki

    2011-02-15

    Objectives: The aim of this study was to evaluate the reference level of urinary cadmium (Cd) that caused renal effects. An updated hybrid approach was used to estimate the benchmark doses (BMDs) and their 95% lower confidence limits (BMDL) in subjects with a wide range of exposure to Cd. Methods: The total number of subjects was 1509 (650 men and 859 women) in non-polluted areas and 3103 (1397 men and 1706 women) in the environmentally exposed Kakehashi river basin. We measured urinary cadmium (U-Cd) as a marker of long-term exposure, and {beta}2-microglobulin ({beta}2-MG) as a marker of renal effects. The BMD and BMDL that corresponded to an additional risk (BMR) of 5% were calculated with background risk at zero exposure set at 5%. Results: The U-Cd BMDL for {beta}2-MG was 3.5 {mu}g/g creatinine in men and 3.7 {mu}g/g creatinine in women. Conclusions: The BMDL values for a wide range of U-Cd were generally within the range of values measured in non-polluted areas in Japan. This indicated that the hybrid approach is a robust method for different ranges of cadmium exposure. The present results may contribute further to recent discussions on health risk assessment of Cd exposure.

  13. The Test of Reference.

    ERIC Educational Resources Information Center

    Childers, Thomas

    1980-01-01

    Reports the results of an unobtrusive study, from a user's viewpoint, of reference services available in the Suffolk Cooperative Library System. The study raises questions of policy centering around user expectations of library reference services. (RAA)

  14. Genetics Home Reference

    MedlinePlus

    Skip Navigation Bar Home Current Issue Past Issues Genetics Home Reference Past Issues / Spring 2007 Table of ... of this page please turn Javascript on. The Genetics Home Reference (GHR) Web site — ghr.nlm.nih. ...

  15. Best Reference Sources 2001.

    ERIC Educational Resources Information Center

    Coutts, Brian; McConnell, Tamara

    2002-01-01

    Presents an annotated list of the best reference materials published in 2001. Discusses activity in the reference publishing industry; costs; and lists print materials, Web sites, databases, and CD-ROMs. (LRW)

  16. The effect of positive thinking training on the level of spiritual well-being among the patients with coronary artery diseases referred to Imam Reza specialty and subspecialty clinic in Shiraz, Iran: A randomized controlled clinical trial

    PubMed Central

    Ghodsbin, Fariba; Safaei, Marzieh; Jahanbin, Iran; Ostovan, Mohammad Ali; Keshvarzi, Sareh

    2015-01-01

    BACKGROUND Positive thinking which is derived from an optimistic view toward the universe and plays an important role in the incidence of better and a more targeted behavior among human beings. It can improve spiritual health in the individuals through increased communication with God and thanksgiving and accelerate the healing process. Accordingly, we aimed to evaluate the effect of positive thinking on the level of spiritual health in the patients with coronary artery disease (CAD) referred to Imam Reza specialty and subspecialty clinic in Shiraz, Iran. METHODS In this study randomized controlled clinical trial, we enrolled 90 patients with confirmed CAD referred to Imam Reza clinic, Shiraz, during April to July 2013. A blocking randomization method was used to randomize the final 90 participants into intervention (n = 45) and control groups (n = 45). After obtaining written informed consent, the participants were asked to complete two questionnaires. Data were collected using Ellison and Paloutzian’s spiritual well-being scale (SWBS) and a demographic questionnaire. The patients in the intervention group participated in 7 training sessions on positive thinking in which several topics were discussed. The SWBS questionnaire was completed two more times by the participants; once immediately after, and once 1 month after the intervention. 16 patients were excluded from the study due to different reasons, and finally the analysis was performed on 74 patients. RESULTS The mean ± standard deviation (SD) of spiritual well-being (SWB) increased from 88.71 ± 12.5 to 96.63 ± 12.58 in the intervention group; while, it decreased from 93.19 ± 17.55 to 94.45 ± 16.01 in the control group in the interval of before and 1 month after the intervention. We observed a statistically significant difference between the two groups regarding both variables of time and group (P < 0.001). CONCLUSION SWB is an important factor which should be considered in the treatment process, and

  17. Assessment of Reference Services.

    ERIC Educational Resources Information Center

    Von Seggern, Marilyn

    1987-01-01

    This annotated bibliography of materials dealing with the evaluation of library reference services is arranged by category including literature success, quality, and accuracy of answers; cost and task analysis; interviews and communication; classification of reference questions; reference collections; staff availability; use and nonuse of…

  18. Academic Library Reference Services.

    ERIC Educational Resources Information Center

    Batt, Fred

    This examination of the philosophy and objectives of academic library reference services provides an overview of the major reference approaches to fulfilling the following primary objectives of reference services: (1) providing accurate answers to patrons' questions and/or helping patrons find sources to pursue their research needs; (2) building…

  19. High frequency reference electrode

    DOEpatents

    Kronberg, J.W.

    1994-05-31

    A high frequency reference electrode for electrochemical experiments comprises a mercury-calomel or silver-silver chloride reference electrode with a layer of platinum around it and a layer of a chemically and electrically resistant material such as TEFLON around the platinum covering all but a small ring or halo' at the tip of the reference electrode, adjacent to the active portion of the reference electrode. The voltage output of the platinum layer, which serves as a redox electrode, and that of the reference electrode are coupled by a capacitor or a set of capacitors and the coupled output transmitted to a standard laboratory potentiostat. The platinum may be applied by thermal decomposition to the surface of the reference electrode. The electrode provides superior high-frequency response over conventional electrodes. 4 figs.

  20. High frequency reference electrode

    DOEpatents

    Kronberg, James W.

    1994-01-01

    A high frequency reference electrode for electrochemical experiments comprises a mercury-calomel or silver-silver chloride reference electrode with a layer of platinum around it and a layer of a chemically and electrically resistant material such as TEFLON around the platinum covering all but a small ring or "halo" at the tip of the reference electrode, adjacent to the active portion of the reference electrode. The voltage output of the platinum layer, which serves as a redox electrode, and that of the reference electrode are coupled by a capacitor or a set of capacitors and the coupled output transmitted to a standard laboratory potentiostat. The platinum may be applied by thermal decomposition to the surface of the reference electrode. The electrode provides superior high-frequency response over conventional electrodes.

  1. Optical voltage reference

    DOEpatents

    Rankin, Richard; Kotter, Dale

    1994-01-01

    An optical voltage reference for providing an alternative to a battery source. The optical reference apparatus provides a temperature stable, high precision, isolated voltage reference through the use of optical isolation techniques to eliminate current and impedance coupling errors. Pulse rate frequency modulation is employed to eliminate errors in the optical transmission link while phase-lock feedback is employed to stabilize the frequency to voltage transfer function.

  2. Optical voltage reference

    DOEpatents

    Rankin, R.; Kotter, D.

    1994-04-26

    An optical voltage reference for providing an alternative to a battery source is described. The optical reference apparatus provides a temperature stable, high precision, isolated voltage reference through the use of optical isolation techniques to eliminate current and impedance coupling errors. Pulse rate frequency modulation is employed to eliminate errors in the optical transmission link while phase-lock feedback is employed to stabilize the frequency to voltage transfer function. 2 figures.

  3. Leading Education Reference Sources.

    ERIC Educational Resources Information Center

    Spencer, Michael D.

    This annotated bibliography focuses on, but is not limited to, reference sources on education found in the library at St. Bonaventure University, New York. The ERIC database leads the list of leading education reference sources. Also mentioned are the "Thesaurus of ERIC Descriptors" and the Academic Index (InfoTrak) computer system. Other…

  4. Reference Service Training Manual.

    ERIC Educational Resources Information Center

    Mielke, John; Young, William

    This manual is primarily designed as an orientation program for librarians new to the Reference Services Division at the State University of New York at Albany University Libraries. It contains practical information and some of the procedures necessary for providing service at the reference desk in these libraries. The appendices provide samples…

  5. Marketing Reference Services.

    ERIC Educational Resources Information Center

    Norman, O. Gene

    1995-01-01

    Relates the marketing concept to library reference services. Highlights include a review of the literature and an overview of marketing, including research, the marketing mix, strategic plan, marketing plan, and marketing audit. Marketing principles are applied to reference services through the marketing mix elements of product, price, place, and…

  6. Library Reference Service.

    ERIC Educational Resources Information Center

    Schippleck, Suzanne

    The Inglewood, California, public library provides a manual on reference service. The theory, purpose, and objectives of reference are noted, and goals and activities are described in terms of budget, personnel, resources, and services. A chapter on organization covers service structure, information services, relationships with other library…

  7. Rethinking Virtual Reference

    ERIC Educational Resources Information Center

    Tenopir, Carol

    2004-01-01

    Virtual reference services seem a natural extension of libraries digital collections and the emphasis on access to the library anytime, anywhere. If patrons use the library from home, it makes sense to provide them with person-to-person online reference. The Library of Congress (LC), OCLC, and several large library systems have developed and…

  8. Automated Periodical Reference Service.

    ERIC Educational Resources Information Center

    Ellefsen, David

    1985-01-01

    Describes public library reference service which allows patrons to type out search instructions on a computer terminal, review and select references, and receive, by high-speed printer, facsimile copy of selected periodical articles. Development of periodicals center at main county library and use of self-coaching SEARCH HELPER system are…

  9. Ethics and Reference Services.

    ERIC Educational Resources Information Center

    Danielson, Elena S.

    1997-01-01

    While revised ethical codes provide helpful guidelines, reference archivists face many ethical questions raised by rapidly evolving technology, changing expectations, and inconsistent privacy laws that have no clear answers. Discusses issues related to reference searching, codification of ethics, cultural property and the responsibility of…

  10. Creating a Reference Toolbox.

    ERIC Educational Resources Information Center

    Scott, Jane

    1997-01-01

    To help students understand that references are tools used to locate specific information, one librarian has her third-grade students create their own reference toolboxes as she introduces dictionaries, atlases, encyclopedias, and thesauri. Presents a lesson plan to introduce print and nonprint thesauri to third and fourth graders and includes a…

  11. An Online Reference System.

    ERIC Educational Resources Information Center

    Chisman, Janet; Treat, William

    1984-01-01

    Describes a computer aid developed to assist in academic library reference service using the DataPhase Circulation System, an automated system that features full cataloging records in database and permits local programing. Access points (subject, type of reference work, course) and database structure and user screens are highlighted. (EJS)

  12. Uranium reference materials

    SciTech Connect

    Donivan, S.; Chessmore, R.

    1987-07-01

    The Technical Measurements Center has prepared uranium mill tailings reference materials for use by remedial action contractors and cognizant federal and state agencies. Four materials were prepared with varying concentrations of radionuclides, using three tailings materials and a river-bottom soil diluent. All materials were ground, dried, and blended thoroughly to ensure homogeneity. The analyses on which the recommended values for nuclides in the reference materials are based were performed, using independent methods, by the UNC Geotech (UNC) Chemistry Laboratory, Grand Junction, Colorado, and by C.W. Sill (Sill), Idaho National Engineering Laboratory, Idaho Falls, Idaho. Several statistical tests were performed on the analytical data to characterize the reference materials. Results of these tests reveal that the four reference materials are homogeneous and that no large systematic bias exists between the analytical methods used by Sill and those used by TMC. The average values for radionuclides of the two data sets, representing an unbiased estimate, were used as the recommended values for concentrations of nuclides in the reference materials. The recommended concentrations of radionuclides in the four reference materials are provided. Use of these reference materials will aid in providing uniform standardization among measurements made by remedial action contractors. 11 refs., 9 tabs.

  13. Automation and Job Satisfaction among Reference Librarians.

    ERIC Educational Resources Information Center

    Whitlatch, Jo Bell

    1991-01-01

    Discussion of job satisfaction and the level of job performance focuses on the effect of automation on job satisfaction among reference librarians. The influence of stress is discussed, a job strain model is explained, and examples of how to design a job to reduce the stress caused by automation are given. (12 references) (LRW)

  14. Reach for Reference. Grolier's The Civil War

    ERIC Educational Resources Information Center

    Safford, Barbara Ripp

    2005-01-01

    This column describes Grolier's new ten-volume reference set, "The Civil War." The volumes are easy to handle and the set's appearance is designed to appeal to middle level students. Arrangement is alphabetical from Abolition in volume one to Zouaves in volume ten with reasonable cross references to other relevant articles. Each volume contains a…

  15. Value of Information References

    SciTech Connect

    Morency, Christina

    2014-12-12

    This file contains a list of relevant references on value of information (VOI) in RIS format. VOI provides a quantitative analysis to evaluate the outcome of the combined technologies (seismology, hydrology, geodesy) used to monitor Brady's Geothermal Field.

  16. Enterprise Reference Library

    NASA Technical Reports Server (NTRS)

    Bickham, Grandin; Saile, Lynn; Havelka, Jacque; Fitts, Mary

    2011-01-01

    Introduction: Johnson Space Center (JSC) offers two extensive libraries that contain journals, research literature and electronic resources. Searching capabilities are available to those individuals residing onsite or through a librarian s search. Many individuals have rich collections of references, but no mechanisms to share reference libraries across researchers, projects, or directorates exist. Likewise, information regarding which references are provided to which individuals is not available, resulting in duplicate requests, redundant labor costs and associated copying fees. In addition, this tends to limit collaboration between colleagues and promotes the establishment of individual, unshared silos of information The Integrated Medical Model (IMM) team has utilized a centralized reference management tool during the development, test, and operational phases of this project. The Enterprise Reference Library project expands the capabilities developed for IMM to address the above issues and enhance collaboration across JSC. Method: After significant market analysis for a multi-user reference management tool, no available commercial tool was found to meet this need, so a software program was built around a commercial tool, Reference Manager 12 by The Thomson Corporation. A use case approach guided the requirements development phase. The premise of the design is that individuals use their own reference management software and export to SharePoint when their library is incorporated into the Enterprise Reference Library. This results in a searchable user-specific library application. An accompanying share folder will warehouse the electronic full-text articles, which allows the global user community to access full -text articles. Discussion: An enterprise reference library solution can provide a multidisciplinary collection of full text articles. This approach improves efficiency in obtaining and storing reference material while greatly reducing labor, purchasing and

  17. Precision displacement reference system

    DOEpatents

    Bieg, Lothar F.; Dubois, Robert R.; Strother, Jerry D.

    2000-02-22

    A precision displacement reference system is described, which enables real time accountability over the applied displacement feedback system to precision machine tools, positioning mechanisms, motion devices, and related operations. As independent measurements of tool location is taken by a displacement feedback system, a rotating reference disk compares feedback counts with performed motion. These measurements are compared to characterize and analyze real time mechanical and control performance during operation.

  18. Membrane reference electrode

    DOEpatents

    Redey, L.; Bloom, I.D.

    1988-01-21

    A reference electrode utilizes a small thin, flat membrane of a highly conductive glass placed on a small diameter insulator tube having a reference material inside in contact with an internal voltage lead. When the sensor is placed in a non-aqueous ionic electrolytic solution, the concentration difference across the glass membrane generates a low voltage signal in precise relationship to the concentration of the species to be measured, with high spatial resolution. 2 figs.

  19. Cooperative Reference: Hazards, Rewards, Prospects.

    ERIC Educational Resources Information Center

    Morgan, Candace D.; And Others

    1979-01-01

    Discusses the problems, benefits, and future of cooperative library reference services in five separate papers: (1) keynote address; (2) interlibrary reference communication; (3) quality control; (4) computerized cooperative reference; and (5) national reference service. (JD)

  20. Reference Man anatomical model

    SciTech Connect

    Cristy, M.

    1994-10-01

    The 70-kg Standard Man or Reference Man has been used in physiological models since at least the 1920s to represent adult males. It came into use in radiation protection in the late 1940s and was developed extensively during the 1950s and used by the International Commission on Radiological Protection (ICRP) in its Publication 2 in 1959. The current Reference Man for Purposes of Radiation Protection is a monumental book published in 1975 by the ICRP as ICRP Publication 23. It has a wealth of information useful for radiation dosimetry, including anatomical and physiological data, gross and elemental composition of the body and organs and tissues of the body. The anatomical data includes specified reference values for an adult male and an adult female. Other reference values are primarily for the adult male. The anatomical data include much data on fetuses and children, although reference values are not established. There is an ICRP task group currently working on revising selected parts of the Reference Man document.

  1. Microgrid cyber security reference architecture.

    SciTech Connect

    Veitch, Cynthia K.; Henry, Jordan M.; Richardson, Bryan T.; Hart, Derek H.

    2013-07-01

    This document describes a microgrid cyber security reference architecture. First, we present a high-level concept of operations for a microgrid, including operational modes, necessary power actors, and the communication protocols typically employed. We then describe our motivation for designing a secure microgrid; in particular, we provide general network and industrial control system (ICS)-speci c vulnerabilities, a threat model, information assurance compliance concerns, and design criteria for a microgrid control system network. Our design approach addresses these concerns by segmenting the microgrid control system network into enclaves, grouping enclaves into functional domains, and describing actor communication using data exchange attributes. We describe cyber actors that can help mitigate potential vulnerabilities, in addition to performance bene ts and vulnerability mitigation that may be realized using this reference architecture. To illustrate our design approach, we present a notional a microgrid control system network implementation, including types of communica- tion occurring on that network, example data exchange attributes for actors in the network, an example of how the network can be segmented to create enclaves and functional domains, and how cyber actors can be used to enforce network segmentation and provide the neces- sary level of security. Finally, we describe areas of focus for the further development of the reference architecture.

  2. Writing More Informative Letters of Reference

    PubMed Central

    Wright, Scott M; Ziegelstein, Roy C

    2004-01-01

    Writing a meaningful and valuable letter of reference is not an easy task. Several factors influence the quality of any letter of reference. First, the accuracy and reliability of the writer's impressions and judgment depend on how well he knows the individual being described. Second, the writer's frame of reference, which is determined by the number of persons at the same level that he has worked with, will impact the context and significance of his beliefs and estimations. Third, the letter-writing skills of the person composing the letter will naturally affect the letter. To support the other components of a candidate's application, a letter of reference should provide specific examples of how an individual's behavior or attitude compares to a reference group and should assess “intangibles” that are hard to glean from a curriculum vitae or from test scores. This report offers suggestions that should help physicians write more informative letters of reference. PMID:15109330

  3. Setting reference targets

    SciTech Connect

    Ruland, R.E.

    1997-04-01

    Reference Targets are used to represent virtual quantities like the magnetic axis of a magnet or the definition of a coordinate system. To explain the function of reference targets in the sequence of the alignment process, this paper will first briefly discuss the geometry of the trajectory design space and of the surveying space, then continue with an overview of a typical alignment process. This is followed by a discussion on magnet fiducialization. While the magnetic measurement methods to determine the magnetic centerline are only listed (they will be discussed in detail in a subsequent talk), emphasis is given to the optical/mechanical methods and to the task of transferring the centerline position to reference targets.

  4. NASCAP programmer's reference manual

    NASA Technical Reports Server (NTRS)

    Mandell, M. J.; Stannard, P. R.; Katz, I.

    1993-01-01

    The NASA Charging Analyzer Program (NASCAP) is a computer program designed to model the electrostatic charging of complicated three-dimensional objects, both in a test tank and at geosynchronous altitudes. This document is a programmer's reference manual and user's guide. It is designed as a reference to experienced users of the code, as well as an introduction to its use for beginners. All of the many capabilities of NASCAP are covered in detail, together with examples of their use. These include the definition of objects, plasma environments, potential calculations, particle emission and detection simulations, and charging analysis.

  5. Aluminum reference electrode

    DOEpatents

    Sadoway, Donald R.

    1988-01-01

    A stable reference electrode for use in monitoring and controlling the process of electrolytic reduction of a metal. In the case of Hall cell reduction of aluminum, the reference electrode comprises a pool of molten aluminum and a solution of molten cryolite, Na.sub.3 AlF.sub.6, wherein the electrical connection to the molten aluminum does not contact the highly corrosive molten salt solution. This is accomplished by altering the density of either the aluminum (decreasing the density) or the electrolyte (increasing the density) so that the aluminum floats on top of the molten salt solution.

  6. Multifunctional reference electrode

    DOEpatents

    Redey, L.; Vissers, D.R.

    1981-12-30

    A multifunctional, low mass reference electrode of a nickel tube, thermocouple means inside the nickel tube electrically insulated therefrom for measuring the temperature thereof, a housing surrounding the nickel tube, an electrolyte having a fixed sulfide ion activity between the housing and the outer surface of the nickel tube forming the nickel/nickel sulfide/sulfide half-cell are described. An ion diffusion barrier is associated with the housing in contact with the electrolyte. Also disclosed is a cell using the reference electrode to measure characteristics of a working electrode.

  7. Aluminum reference electrode

    DOEpatents

    Sadoway, D.R.

    1988-08-16

    A stable reference electrode is described for use in monitoring and controlling the process of electrolytic reduction of a metal. In the case of Hall cell reduction of aluminum, the reference electrode comprises a pool of molten aluminum and a solution of molten cryolite, Na[sub 3]AlF[sub 6], wherein the electrical connection to the molten aluminum does not contact the highly corrosive molten salt solution. This is accomplished by altering the density of either the aluminum (decreasing the density) or the electrolyte (increasing the density) so that the aluminum floats on top of the molten salt solution. 1 fig.

  8. Reference selenocentric net

    NASA Astrophysics Data System (ADS)

    Nefedyev, Yura

    2012-08-01

    The catalogues based on mission “Apollo” and reference nets of the west lunar hemisphere made by missions “Zond 5”, ”Zond 8” cover small part of the Moon surface (zone from - 20 to +40 degrees by latitude). Three ALSEP stations were used to transform “Apollo” topographic coordinates. Transformation mean - square errors are less than 80 meters and measurement’s errors are about 60 meters. On this account positions inaccuracy near and between ALSEP stations are less 150 meters. The offset from place of the location ALSEP enlarges the supposed mistake is more than 300 m and this is a major part of the lunar surface. Catalogues of the mission “Apollo” realize quasidynamic coordinate system. Distribution reference nets DMA/A 15, NOS/USGS and DMA/603 mission “Apollo” on visible side of the Moon didn’t bring in appreciable results. Only KSC - 1162 realizes dynamic coordinate system and covers zone from - 70 to +70 degrees by latitude. The reference selenodetic net KSC - 1162 was made in the dynamic coordinate system. Analysis KSC - 1162 catalogue shows it corresponds to an essential requirements. It has enough reference points to cove r main areas of the lunar visible side. Reference points accuracy for plan coordinates is ± 40 meters and it is ± 80 in height. The purposes of investigation are increasing concentration accuracy and expansion of selenodetic control system based on optimal coordinate transformations. At present the best method of the expansion selenodetic reference net wide lunar area is the use of coordinate’s transformation matrix. Constituents of matrix and displacement vectors can be obtained by transform available general points in KSC - 1162 and transformable in its system catalogues. As a result was obtained summary reference net by expansion KSC - 1162 selenodetic system using 12 cosmic and ground selenodesic catalogues. In the future we plan to bind to the KSC - 1162 catalogue reference coordinate system data

  9. Multifunctional reference electrode

    DOEpatents

    Redey, Laszlo; Vissers, Donald R.

    1983-01-01

    A multifunctional, low mass reference electrode of a nickel tube, thermocouple means inside the nickel tube electrically insulated therefrom for measuring the temperature thereof, a housing surrounding the nickel tube, an electrolyte having a fixed sulfide ion activity between the housing and the outer surface of the nickel tube forming the nickel/nickel sulfide/sulfide half-cell. An ion diffusion barrier is associated with the housing in contact with the electrolyte. Also disclosed is a cell using the reference electrode to measure characteristics of a working electrode.

  10. Assessment and Accountability in Reference Work. Part V: Reference Evaluation.

    ERIC Educational Resources Information Center

    Hults, Patricia; And Others

    1992-01-01

    Includes four articles that discuss the evaluation of library reference services. Topics addressed include unobtrusive testing; measuring the accountability of reference librarians by behavioral rather than factual evaluation; on-the-job training of reference librarians; and faculty expectations of academic reference librarians. (52 references)…

  11. Chat Reference. SPEC Kit.

    ERIC Educational Resources Information Center

    Ronan, Jana, Comp.; Turner, Carol, Comp.

    2002-01-01

    This SPEC (Systems and Procedures Exchange Center) Kit presents the results of a survey of Association of Research Libraries (ARL) member libraries designed to gather data on chat reference service. A total of 66 of 124 ARL member libraries responded to the survey. A copy of the questionnaire with tabulated results is presented. Representative…

  12. Reference Sources for Nursing

    ERIC Educational Resources Information Center

    Nursing Outlook, 1976

    1976-01-01

    The ninth revision (including a Canadian supplement) of a list of nursing reference works lists items in the following sections: abstract journals, audiovisuals, bibliographies, dictionaries, directories, drug lists and pharmacologies, educational programs, histories, indexes, legal guides, library administration and organization, research grants,…

  13. THAI, REFERENCE GRAMMAR.

    ERIC Educational Resources Information Center

    NOSS, RICHARD B.

    A REFERENCE GRAMMAR FOR THE THAI LANGUAGE IS PROVIDED. THE MAIN STRUCTURAL FEATURES OF STANDARD SPOKEN THAI ARE OUTLINED AND ELABORATED BY SUBCLASSIFICATION AND EXAMPLE. IN ADDITION, AN INDEX OF MINOR FORM-CLASS MEMBERS IS PROVIDED. THE APPROACH TO CLASSIFICATION OF GRAMMATICAL FEATURES FOLLOWS CURRENT TECHNIQUES OF AMERICAN DESCRIPTIVE…

  14. Best Reference 2006

    ERIC Educational Resources Information Center

    Coutts, Brian E.; LaGuardia, Cheryl

    2007-01-01

    Reading reference sources, whether on paper or on the screen, often leads to enlightened thinking, especially for library patrons. In an earlier age, enlightened monarchs surrounded themselves with leading intellectuals and patronized the arts. Today, people have the advantage of the world's collected wisdom at their fingertips in the form of…

  15. The Unreliability of References

    ERIC Educational Resources Information Center

    Barden, Dennis M.

    2008-01-01

    When search consultants, like the author, are invited to propose their services in support of a college or university seeking new leadership, they are generally asked a fairly standard set of questions. But there is one question that they find among the most difficult to answer: How do they check a candidate's references to ensure that they know…

  16. Virtual Reference Services.

    ERIC Educational Resources Information Center

    Brewer, Sally

    2003-01-01

    As the need to access information increases, school librarians must create virtual libraries. Linked to reliable reference resources, the virtual library extends the physical collection and library hours and lets students learn to use Web-based resources in a protected learning environment. The growing number of virtual schools increases the need…

  17. Internet Issues in Reference.

    ERIC Educational Resources Information Center

    Tenopir, Carol

    1995-01-01

    Discusses the impact of Internet access on library reference services based on 1994 interviews with almost two dozen university librarians. Highlights include library policy, overcrowded workstations and methods of controlling use, recreational use of terminals that interferes with more formal library use, restriction as a form of censorship, and…

  18. Reference Model Development

    SciTech Connect

    Jepsen, Richard

    2011-11-02

    Presentation from the 2011 Water Peer Review in which principal investigator discusses project progress to develop a representative set of Reference Models (RM) for the MHK industry to develop baseline cost of energy (COE) and evaluate key cost component/system reduction pathways.

  19. Generating Multimodal References

    ERIC Educational Resources Information Center

    van der Sluis, Ielka; Krahmer, Emiel

    2007-01-01

    This article presents a new computational model for the generation of multimodal referring expressions (REs), based on observations in human communication. The algorithm is an extension of the graph-based algorithm proposed by Krahmer, van Erk, and Verleg (2003) and makes use of a so-called Flashlight Model for pointing. The Flashlight Model…

  20. Evaluating the Reference Product.

    ERIC Educational Resources Information Center

    Strong, Gary E.

    1980-01-01

    Examines quantitative and qualitative evaluation and analysis of Washington State Library reference activities, based on research activities of the Consortium for Public Library Innovation. Several methods of data collection for a sample day are discussed, including a user ticket and a patterns of information requests form. (Author)

  1. International reference ionosphere 1990

    NASA Technical Reports Server (NTRS)

    Bilitza, Dieter; Rawer, K.; Bossy, L.; Kutiev, I.; Oyama, K.-I.; Leitinger, R.; Kazimirovsky, E.

    1990-01-01

    The International Reference Ionosphere 1990 (IRI-90) is described. IRI described monthly averages of the electron density, electron temperature, ion temperature, and ion composition in the altitude range from 50 to 1000 km for magnetically quiet conditions in the non-auroral ionosphere. The most important improvements and new developments are summarized.

  2. Reference Services in Archives.

    ERIC Educational Resources Information Center

    Whalen, Lucille; And Others

    1986-01-01

    This 16-article issue focuses on history, policy, services, users, organization, evaluation, and automation of the archival reference process. Collections at academic research libraries, a technical university, Board of Education, business archives, a bank, labor and urban archives, a manuscript repository, religious archives, and regional history…

  3. Genetics Home Reference: cherubism

    MedlinePlus

    ... About Genetics Home Reference Site Map Contact Us Selection Criteria for Links Copyright Privacy Accessibility FOIA Viewers & Players U.S. Department of Health & Human Services National Institutes of Health National Library of Medicine Lister Hill National Center for Biomedical Communications 8600 ...

  4. Shuttle Reference Data

    NASA Astrophysics Data System (ADS)

    2002-12-01

    This collection of shuttle reference data contains the following information: shuttle abort history, shuttle abort modes, abort decisions, space shuttle rendezvous maneuvers, space shuttle main engines, space shuttle solid rocket boosters, hold-down posts, SRB (solid rocket boosters) ignition, electrical power distribution, hydraulic power units, thrust vector control, SBR rate gyro assemblies, SBR separation and Space Shuttle Super Super Light Weight Tank (SLWT).

  5. Hospitality Services Reference Book.

    ERIC Educational Resources Information Center

    Texas Tech Univ., Lubbock. Home Economics Curriculum Center.

    This reference book provides information needed by employees in hospitality services occupations. It includes 29 chapters that cover the following topics: the hospitality services industry; professional ethics; organization and management structures; safety practices and emergency procedures; technology; property maintenance and repair; purchasing…

  6. Dietary Reference Intakes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Dietary Reference Intakes (DRI) are recommendations intended to provide a framework for nutrient intake evaluation, as well as meal planning on the basis of nutrient adequacy. They are nutrient, not food based recommendations, created with chronic disease risk reduction as the primary goal, as ...

  7. The Reference Encounter Model.

    ERIC Educational Resources Information Center

    White, Marilyn Domas

    1983-01-01

    Develops model of the reference interview which explicitly incorporates human information processing, particularly schema ideas presented by Marvin Minsky and other theorists in cognitive processing and artificial intelligence. Questions are raised concerning use of content analysis of transcribed verbal protocols as methodology for studying…

  8. A GUJARATI REFERENCE GRAMMAR.

    ERIC Educational Resources Information Center

    CARDONA, GEORGE

    THIS REFERENCE GRAMMAR WAS WRITTEN TO FILL THE NEED FOR AN UP-TO-DATE ANALYSIS OF THE MODERN LANGUAGE SUITABLE FOR LANGUAGE LEARNERS AS WELL AS LINGUISTS. THE AUTHOR LISTS IN THE INTRODUCTION THOSE STUDIES PREVIOUS TO THIS ONE WHICH MAY BE OF INTEREST TO THE READER. INCLUDED IN HIS ANALYSIS OF THE LANGUAGE ARE MAJOR CHAPTERS ON--(1) PHONOLOGY, (2)…

  9. Reference-Dependent Sympathy

    ERIC Educational Resources Information Center

    Small, Deborah A.

    2010-01-01

    Natural disasters and other traumatic events often draw a greater charitable response than do ongoing misfortunes, even those that may cause even more widespread misery, such as famine or malaria. Why is the response disproportionate to need? The notion of reference dependence critical to Prospect Theory (Kahneman & Tversky, 1979) maintains that…

  10. Selecting a Reference Object

    ERIC Educational Resources Information Center

    Miller, Jared E.; Carlson, Laura A.; Hill, Patrick L.

    2011-01-01

    One way to describe the location of an object is to relate it to another object. Often there are many nearby objects, each of which could serve as a candidate to be the reference object. A common theoretical assumption is that features that make a given object salient relative to the candidate set are instrumental in determining which is selected.…

  11. Reference Book Guides.

    ERIC Educational Resources Information Center

    Webb, Bill, Ed.

    For each reference work there is a 5 1/2 x 8 1/2" card with information about the work in brief, standardized format. The card indicates what the subject coverage is, the types of materials included, the service given, frequency of publication, procedure for use, an example of the procedure, a sample entry with explanatory notes, other places to…

  12. Reference Collections and Standards.

    ERIC Educational Resources Information Center

    Winkel, Lois

    1999-01-01

    Reviews six reference materials for young people: "The New York Public Library Kid's Guide to Research"; "National Audubon Society First Field Guide. Mammals"; "Star Wars: The Visual Dictionary"; "Encarta Africana"; "World Fact Book, 1998"; and "Factastic Book of 1001 Lists". Includes ordering information.(AEF)

  13. Reference materials for new psychoactive substances.

    PubMed

    Archer, Roland P; Treble, Ric; Williams, Keith

    2011-01-01

    Historically, the appearance of new psychoactive materials (and hence the requirement for new reference standards) has been relatively slow. This position has now changed, with 101 new psychoactive substances reported to EMCDDA-Europol since 2006. The newly reported materials, and associated metabolites, require properly certified reference materials to permit reliable identification and quantification. The traditional approach and timescales of reference material production and certification are being increasingly challenged by the appearance of these new substances. Reference material suppliers have to adopt new strategies to meet the needs of laboratories. This situation is particularly challenging for toxicology standards as the metabolism of many of these substances is initially unknown. Reference material production often involves synthesis from first principles. While it is possible to synthesis these materials, there can be significant difficulties, from synthetic complexities through to the need to use controlled materials. These issues are examined through a discussion of the synthesis of cathinones. Use of alternative sources, including pharmaceutical impurity materials or internet sourced products, as starting materials for conversion into appropriately certified reference materials are also discussed. The sudden appearance and sometimes brief lifetime in the market place of many of these novel legal highs or research chemicals present commercial difficulties for reference material producers. The need for collaboration at all levels is highlighted as essential to rapid identification of requirements for new reference materials. National or international commissioning or support may also be required to permit reference material producers to recover their development costs. PMID:21744516

  14. MSDS sky reference and preamplifier study

    NASA Technical Reports Server (NTRS)

    Larsen, L.; Stewart, S.; Lambeck, P.

    1974-01-01

    The major goals in re-designing the Multispectral Scanner and Data System (MSDS) sky reference are: (1) to remove the sun-elevation angle and aircraft-attitude angle dependence from the solar-sky illumination measurement, and (2) to obtain data on the optical state of the atmosphere. The present sky reference is dependent on solar elevation and provides essentially no information on important atmospheric parameters. Two sky reference designs were tested. One system is built around a hyperbolic mirror and the reflection approach. A second approach to a sky reference utilizes a fish-eye lens to obtain a 180 deg field of view. A detailed re-design of the present sky reference around the fish-eye approach, even with its limitations, is recommended for the MSDS system. A preamplifier study was undertaken to find ways of improving the noise-equivalent reflectance by reducing the noise level for silicon detector channels on the MSDS.

  15. Reference Ranges & What They Mean

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? Reference Ranges and What They Mean Share this page: Was this page helpful? Overview | Reference range defined | Where are the reference ranges? | Limits ...

  16. OSH technical reference manual

    SciTech Connect

    Not Available

    1993-11-01

    In an evaluation of the Department of Energy (DOE) Occupational Safety and Health programs for government-owned contractor-operated (GOCO) activities, the Department of Labor`s Occupational Safety and Health Administration (OSHA) recommended a technical information exchange program. The intent was to share written safety and health programs, plans, training manuals, and materials within the entire DOE community. The OSH Technical Reference (OTR) helps support the secretary`s response to the OSHA finding by providing a one-stop resource and referral for technical information that relates to safe operations and practice. It also serves as a technical information exchange tool to reference DOE-wide materials pertinent to specific safety topics and, with some modification, as a training aid. The OTR bridges the gap between general safety documents and very specific requirements documents. It is tailored to the DOE community and incorporates DOE field experience.

  17. The NPL reference hazemeter

    NASA Astrophysics Data System (ADS)

    Freeman, G. H. C.

    1992-09-01

    The reference hazemeter is a development of a commercial pivotable sphere hazemeter. The principle improvements are a high quality photometer and its associated electronic and temperature controller, a stable power supply for the source and the determination of the lamp current of illuminants A and C, improvements to the optics to achieve a well shaped beam, and mechanical modifications to accommodate the improvements and allow a good mechanical movement. Various tests were carried out to validate the instrument behavior. These identified systematic errors caused by inter-reflections. To reduce the inter-reflection errors, the blue filter and the input lenses were antireflection coated. The reference hazemeter complies with BS 2782--methods of testing plastics; part 5--optical and color properties; method 521A--determination of haze of film and sheet. A calibration service using the hazemeter is now in operation.

  18. Alignment reference device

    DOEpatents

    Patton, Gail Y.; Torgerson, Darrel D.

    1987-01-01

    An alignment reference device provides a collimated laser beam that minimizes angular deviations therein. A laser beam source outputs the beam into a single mode optical fiber. The output end of the optical fiber acts as a source of radiant energy and is positioned at the focal point of a lens system where the focal point is positioned within the lens. The output beam reflects off a mirror back to the lens that produces a collimated beam.

  19. Reference structure tomography

    NASA Astrophysics Data System (ADS)

    Brady, David J.; Pitsianis, Nikos P.; Sun, Xiaobai

    2004-07-01

    Reference structure tomography (RST) uses multidimensional modulations to encode mappings between radiating objects and measurements. RST may be used to image source-density distributions, estimate source parameters, or classify sources. The RST paradigm permits scan-free multidimensional imaging, data-efficient and computation-efficient source analysis, and direct abstraction of physical features. We introduce the basic concepts of RST and illustrate the use of RST for multidimensional imaging based on a geometric radiation model.

  20. Is anaphoric reference cooperative?

    PubMed

    Kantola, Leila; van Gompel, Roger P G

    2016-01-01

    Two experiments investigated whether the choice of anaphoric expression is affected by the presence of an addressee. Following a context sentence and visual scene, participants described a target scene that required anaphoric reference. They described the scene either to an addressee (Experiment 1) or without an addressee (Experiment 2). When an addressee was present in the task, participants used more pronouns and fewer repeated noun phrases when the referent was the grammatical subject in the context sentence than when it was the grammatical object and they used more pronouns when there was no competitor than when there was. They used fewer pronouns and more repeated noun phrases when a visual competitor was present in the scene than when there was no visual competitor. In the absence of an addressee, linguistic context effects were the same as those when an addressee was present, but the visual effect of the competitor disappeared. We conclude that visual salience effects are due to adjustments that speakers make when they produce reference for an addressee, whereas linguistic salience effects appear whether or not speakers have addressees. PMID:26165163

  1. Celestial Reference Frame

    NASA Astrophysics Data System (ADS)

    Jacobs, Christopher S.

    2013-09-01

    Concepts and Background: This paper gives an overview of modern celestial reference frames as realized at radio frequencies using the Very Long baseline Interferometry (VLBI) technique. We discuss basic celestial reference frame concepts, desired properties, and uses. We review the networks of antennas used for this work. We briefly discuss the history of the science of astrometry touching upon the discovery of precession, proper motion, nutation, and parallax, and the field of radio astronomy. Building Celestial Frames: Next, we discuss the multi-step process of building a celestial frame: First candidate sources are identified based on point-like properties from single dish radio telescopes surveys. Second, positions are refined using connected element interferometers such as the Very Large Array, and the ATCA. Third, positions of approximately milli-arcsecond (mas) accuracy are determined using intercontinental VLBI surveys. Fourth, sub-mas positions are determined by multiyear programs using intercontinental VLBI. These sub-mas sets of positions are then verified by multiple teams in preparation for release to non-specialists in the form of an official IAU International Celestial Reference Frame (ICRF). The process described above has until recently been largely restricted to work at S/X-band (2.3/8.4 GHz). However, in the last decade sub-mas work has expanded to include celestial frames at K-band (24 GHz), Ka-band (32 GHz), and Q-band (43 GHz). While these frames currently have the disadvantage of far smaller data sets, the astrophysical quality of the sources themselves improves at these higher frequencies and thus make these frequencies attractive for realizations of celestial reference frames. Accordingly, we review progress at these higher frequency bands. Path to the Future: We discuss prospects for celestial reference frames over the next decade. We present an example of an error budget for astrometric VLBI and discuss the budget's use as a tool for

  2. ZIP - The ZIP-Code Insulation Program (version 1. 0) economic insulation levels for new and existing houses by three-digit ZIP code: Users guide and reference manual

    SciTech Connect

    Petersen, S.R.

    1989-01-01

    ZIP 1.0 (the ZIP-code Insulation program) is a computer program developed to support the DOE Insulation Fact Sheet by providing users with customized estimates of economic levels of residential insulation. These estimates can be made for any location in the United States by entering the first three digits of its ZIP Code. The program and supporting files are contained on a single 5.25-in. diskette for use with microcomputers having an MS-DOS operating system capability. The ZIP program currently calculates economic levels of insulation for attic floors, exterior wood-frame and masonry walls, floor over unheated areas, slab floors, and basement and crawlspace wells. The economic analysis can be conducted for either new or existing houses. Climate parameters are contained in a file on the ZIP diskette and automatically retrieved when the program is run. Regional energy and insulation price data are also retrieved from the ZIP diskette, but these can be overridden to more closely correspond to local prices. Zip can be run for a single ZIP Code and specified heating and cooling system. It can also be run in a ''batch'' mode for any number of consecutive ZIP Codes in order to provide a table of economic insulation levels for use at the state or national level. 4 tabs.

  3. Reference Inflow Characterization for River Resource Reference Model (RM2)

    SciTech Connect

    Neary, Vincent S

    2011-12-01

    Sandia National Laboratory (SNL) is leading an effort to develop reference models for marine and hydrokinetic technologies and wave and current energy resources. This effort will allow the refinement of technology design tools, accurate estimates of a baseline levelized cost of energy (LCoE), and the identification of the main cost drivers that need to be addressed to achieve a competitive LCoE. As part of this effort, Oak Ridge National Laboratory was charged with examining and reporting reference river inflow characteristics for reference model 2 (RM2). Published turbulent flow data from large rivers, a water supply canal and laboratory flumes, are reviewed to determine the range of velocities, turbulence intensities and turbulent stresses acting on hydrokinetic technologies, and also to evaluate the validity of classical models that describe the depth variation of the time-mean velocity and turbulent normal Reynolds stresses. The classical models are found to generally perform well in describing river inflow characteristics. A potential challenge in river inflow characterization, however, is the high variability of depth and flow over the design life of a hydrokinetic device. This variation can have significant effects on the inflow mean velocity and turbulence intensity experienced by stationary and bottom mounted hydrokinetic energy conversion devices, which requires further investigation, but are expected to have minimal effects on surface mounted devices like the vertical axis turbine device designed for RM2. A simple methodology for obtaining an approximate inflow characterization for surface deployed devices is developed using the relation umax=(7/6)V where V is the bulk velocity and umax is assumed to be the near-surface velocity. The application of this expression is recommended for deriving the local inflow velocity acting on the energy extraction planes of the RM2 vertical axis rotors, where V=Q/A can be calculated given a USGS gage flow time

  4. SEI reference mission

    NASA Technical Reports Server (NTRS)

    Weary, Dwayne

    1992-01-01

    Information is given in viewgraph form on the Space Exploration Initiative (SEI). The goal of the reference mission is to expand the human presence to the moon and Mars in order to enhance our understanding of the universe, to seek terrestrial benefits from this exploration, and to establish the beginnings of a sustainable spacefaring civilization. Topics covered here include a phased definition of initial programmatic milestones and follow-on capabilities, near-term mission strategy, a lunar mission timeline, and a Mars mission timeline.

  5. Expanding the Repertoire of Reference.

    ERIC Educational Resources Information Center

    Frantz, Paul

    1991-01-01

    Suggests several ways that reference librarians can improve their skills beyond library school training. Reference interviews are discussed; effective methods of browsing the reference collection are described; opportunities for learning at the reference desk are suggested; and professional reading and study is discussed, including professional…

  6. Bushland, Texas Reference ET Calculator

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Bushland Reference Evapotranspiration (ET) Calculator was developed at the USDA-ARS Conservation and Production Research Laboratory, Bushland, Texas, for calculating grass and alfalfa reference ET. It uses the ASCE Standardized Reference ET Equation for calculating reference ET at hourly and dai...

  7. Coal data: A reference

    SciTech Connect

    Not Available

    1995-02-01

    This report, Coal Data: A Reference, summarizes basic information on the mining and use of coal, an important source of energy in the US. This report is written for a general audience. The goal is to cover basic material and strike a reasonable compromise between overly generalized statements and detailed analyses. The section ``Supplemental Figures and Tables`` contains statistics, graphs, maps, and other illustrations that show trends, patterns, geographic locations, and similar coal-related information. The section ``Coal Terminology and Related Information`` provides additional information about terms mentioned in the text and introduces some new terms. The last edition of Coal Data: A Reference was published in 1991. The present edition contains updated data as well as expanded reviews and additional information. Added to the text are discussions of coal quality, coal prices, unions, and strikes. The appendix has been expanded to provide statistics on a variety of additional topics, such as: trends in coal production and royalties from Federal and Indian coal leases, hours worked and earnings for coal mine employment, railroad coal shipments and revenues, waterborne coal traffic, coal export loading terminals, utility coal combustion byproducts, and trace elements in coal. The information in this report has been gleaned mainly from the sources in the bibliography. The reader interested in going beyond the scope of this report should consult these sources. The statistics are largely from reports published by the Energy Information Administration.

  8. Antares reference telescope system

    NASA Astrophysics Data System (ADS)

    Viswanathan, V. K.; Kaprelian, E.; Swann, T.; Parker, J.; Wolfe, P.; Woodfin, G.; Knight, D.

    Antares is a 24 beam, 40 TW carbon dioxide laser fusion system currently nearing completion. The 24 beams will be focused onto a tiny target. It is to position the targets to within 10 (SIGMA)m of a selected nominal position, which may be anywhere within a fixed spherical region 1 cm in diameter. The Antares reference telescope system is intended to help achieve this goal for alignment and viewing of the various targets used in the laser system. The Antares reference telescope system consists of two similar electrooptical systems positioned in a near orthogonal manner in the target chamber area of the laser. Each of these consists of four subsystems: (1) a fixed 9% optical imaging subsystem which produces an image of the target at the vidicon; (2) a reticle projection subsystem which superimposes an image of the reticle pattern at the vidicon; (3) an adjustable front lighting subsystem which illuminates the target; and (4) an adjustable back lighting subsystem which also can be used to illuminate the target. The various optical, mechanical, and vidicon design considerations and tradeoffs are discussed. The final system chosen and its current status are described.

  9. Sentinel 2 global reference image

    NASA Astrophysics Data System (ADS)

    Dechoz, C.; Poulain, V.; Massera, S.; Languille, F.; Greslou, D.; de Lussy, F.; Gaudel, A.; L'Helguen, C.; Picard, C.; Trémas, T.

    2015-10-01

    Sentinel-2 is a multispectral, high-resolution, optical imaging mission, developed by the European Space Agency (ESA) in the frame of the Copernicus program of the European Commission. In cooperation with ESA, the Centre National d'Etudes Spatiales (CNES) is responsible for the image quality of the project, and will ensure the CAL/VAL commissioning phase. Sentinel-2 mission is devoted the operational monitoring of land and coastal areas, and will provide a continuity of SPOT- and Landsat-type data. Sentinel-2 will also deliver information for emergency services. Launched in 2015 and 2016, there will be a constellation of 2 satellites on a polar sun-synchronous orbit, imaging systematically terrestrial surfaces with a revisit time of 5 days, in 13 spectral bands in visible and shortwave infra-red. Therefore, multi-temporal series of images, taken under the same viewing conditions, will be available. So as to ensure for the multi-temporal registration of the products, specified to be better than 0.3 pixels at 2σ, a Global Reference Image (GRI) will be produced during the CAL/VAL period. This GRI is composed of a set of Sentinel-2 acquisitions, which geometry has been corrected by bundle block adjustment. During L1B processing, Ground Control Points will be taken between this reference image and the sentinel-2 acquisition processed and the geometric model of the image corrected, so as to ensure the good multi-temporal registration. This paper first details the production of the reference during the CALVAL period, and then details the qualification and geolocation performance assessment of the GRI. It finally presents its use in the Level-1 processing chain and gives a first assessment of the multi-temporal registration.

  10. Coastwide Reference Monitoring System (CRMS)

    USGS Publications Warehouse

    2010-01-01

    In 1990, the U.S. Congress enacted the Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA) in response to growing awareness of a land loss crisis in Louisiana. Projects funded by CWPPRA require monitoring and evaluation of project effectiveness, and there is also a need to assess the cumulative effects of all projects to achieve a sustainable coastal environment. In 2003, the Louisiana Office of Coastal Protection and Restoration (OCPR) and the U.S. Geological Survey (USGS) received approval from the CWPPRA Task Force to implement the Coastwide Reference Monitoring System (CRMS) as a mechanism to monitor and evaluate the effectiveness of CWPPRA projects at the project, region, and coastwide levels. The CRMS design implements a multiple reference approach by using aspects of hydrogeomorphic functional assessments and probabilistic sampling. The CRMS program is as dynamic as the coastal habitats it monitors. The program is currently funded through CWPPRA and provides data for a variety of user groups, including resource managers, academics, landowners, and researchers.